FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Aggarwal, S Perusse, SR Tipton, CW Ramesh, R Drew, HD Venkatesan, T Romero, DB Podobedov, VB Weber, A AF Aggarwal, S Perusse, SR Tipton, CW Ramesh, R Drew, HD Venkatesan, T Romero, DB Podobedov, VB Weber, A TI Effect of hydrogen on Pb(Zr, Ti)O-3-based ferroelectric capacitors SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILM CAPACITORS; INDUCED DEGRADATION; ELECTRODE; K1-YLIYTA1-XNBXO3; PB(ZR,TI)O-3; CRYSTAL AB The properties of ferroelectric films are known to degrade when subjected to hydrogen in forming gas anneals. Earlier studies have attributed this degradation to the loss of oxygen from these films during these anneals. In this study, we show that though oxygen is lost during forming gas annealing, hydrogen incorporation is the primary mechanism for the degradation of ferroelectric properties. Raman spectra obtained from the forming gas-annealed films show evidence of polar hydroxil [OH-] bonds in the films. The most probable site for hydrogen ions is discussed based on ionic radii, crystal structure, electrical properties, and Raman spectra. We propose that the hydrogen ion is bonded with one of the apical oxygen ions and prevents the Ti ion from switching. Pyroelectric measurements on forming gas-annealed capacitors confirm that the capacitors no longer possess spontaneous polarization. (C) 1998 American Institute of Physics. [S0003-6951(98)03940-0]. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Univ Maryland, Ctr Superconduct Res, Dept Phys, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI Venkatesan, Thirumalai/E-1667-2013 NR 14 TC 156 Z9 157 U1 1 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 5 PY 1998 VL 73 IS 14 BP 1973 EP 1975 DI 10.1063/1.122339 PG 3 WC Physics, Applied SC Physics GA 124LF UT WOS:000076183300017 ER PT J AU Gann, RG AF Gann, RG TI Fire suppression SO CHEMICAL & ENGINEERING NEWS LA English DT Letter C1 Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. RP Gann, RG (reprint author), Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD OCT 5 PY 1998 VL 76 IS 40 BP 6 EP 6 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 126BE UT WOS:000076272200005 ER PT J AU Kammer, R AF Kammer, R TI Kammer clarifies SO CHEMICAL & ENGINEERING NEWS LA English DT Letter C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kammer, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD OCT 5 PY 1998 VL 76 IS 40 BP 6 EP 6 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 126BE UT WOS:000076272200002 ER PT J AU Allen, AJ Livingston, RA AF Allen, AJ Livingston, RA TI Relationship between differences in silica fume additives and fine-scale microstructural evolution in cement based materials SO ADVANCED CEMENT BASED MATERIALS LA English DT Article DE cement paste; silica fume; microstructure; small-angle scattering ID ANGLE NEUTRON-SCATTERING; X-RAY-SCATTERING; MAXIMUM-ENTROPY METHOD; PORTLAND-CEMENT; HYDRATING CEMENT; TRICALCIUM SILICATE; PASTE; POROSITY; SURFACE; SANS AB The effects on the microstructural development of adding silica fume to cements and concretes during cement hydration have been studied using small-angle neutron scattering and ultrasmall-angle X-ray scattering. A previously developed fractal based microstructural model has been applied to extract representative microstructural parameters from the small-angle scattering data. A link has been established between the existence of coarse or agglomerated particles in the silica fume particle size distribution and possible deleterious microstructural evolution during cement hydration. Published by Elsevier Science Ltd. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. Fed Highway Adm, Mclean, VA USA. RP Allen, AJ (reprint author), NIST, Mat Sci & Engn Lab, Div Ceram, Bldg 223,Room A163, Gaithersburg, MD 20899 USA. NR 56 TC 28 Z9 29 U1 0 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1065-7355 J9 ADV CEM BASED MATER JI Adv. Cem. Based Mater. PD OCT-NOV PY 1998 VL 8 IS 3-4 BP 118 EP 131 DI 10.1016/S1065-7355(98)00015-7 PG 14 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 129XM UT WOS:000076489400004 ER PT J AU Soares, C Trauthen, B Tam, L Seltzer, S Strathearn, G Buchbinder, M AF Soares, C Trauthen, B Tam, L Seltzer, S Strathearn, G Buchbinder, M TI Dosimetry of a balloon source for intravascular brachytherapy. SO AMERICAN JOURNAL OF CARDIOLOGY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. Sharp Mem Hosp, San Diego, CA USA. Radiance Med Syst, Irvine, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0002-9149 J9 AM J CARDIOL JI Am. J. Cardiol. PD OCT PY 1998 VL 82 IS 7A SI SI BP 76S EP 77S PG 2 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA 128LR UT WOS:000076408200202 ER PT J AU Work, TM Raskin, RE Balazs, GH Whittaker, SD AF Work, TM Raskin, RE Balazs, GH Whittaker, SD TI Morphologic and cytochemical characteristics of blood cells from Hawaiian green turtles SO AMERICAN JOURNAL OF VETERINARY RESEARCH LA English DT Article ID CHELONIA-MYDAS; SEA-TURTLE; LEUKOCYTES AB Objective-To identify and characterize blood cells from free-ranging Hawaiian green turtles, Chelonia mydas. Sample Population-26 green turtles from Puako on the island of Hawaii and Kaneohe Bay an the island of Oahu. Procedure-Blood was examined, using light and electron microscopy and cytochemical stains that included benzidine peroxidase, chloroacetate esterase, alpha naphthyl butyrate esterase, acid phosphatase, Sudan black B, periodic acid-Schiff, and toluidine blue. Results-6 types of WBC were identified: lymphocytes, monocytes, thrombocytes, heterophils, basophils, and eosinophils (small and large). Morphologic characteristics of mononuclear cells and most granulocytes were similar to those of cells from other reptiles except that green turtles have both large and small eosinophils. Conclusions-Our classification of green turtle blood cells clarifies improper nomenclature reported previously and provides a reference for future hematologic studies in this species. C1 US Geol Survey, Biol Resource Div, Natl Wildlife Hlth Ctr, Honolulu Field Stn, Honolulu, HI 96850 USA. Univ Florida, Coll Vet Med, Dept Physiol Sci, Gainesville, FL 32610 USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Florida, Interdiscilinary Ctr Biotechnol Res, Electron Microscopy Core Lab, Gainesville, FL 32611 USA. RP Work, TM (reprint author), US Geol Survey, Biol Resource Div, Natl Wildlife Hlth Ctr, Honolulu Field Stn, POB 50167, Honolulu, HI 96850 USA. RI Work, Thierry/F-1550-2015 OI Work, Thierry/0000-0002-4426-9090 NR 20 TC 51 Z9 58 U1 2 U2 6 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 USA SN 0002-9645 J9 AM J VET RES JI Am. J. Vet. Res. PD OCT PY 1998 VL 59 IS 10 BP 1252 EP 1257 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA 135QR UT WOS:000076814600011 PM 9781457 ER PT J AU Shirley, EL AF Shirley, EL TI Revised formulas for diffraction effects with point and extended sources SO APPLIED OPTICS LA English DT Article AB Revised formulas to estimate diffraction effects in radiometry for point and extended sources are derived. They are found to work as well as or better than previous formulas. In some instances the formulas can be written in closed form; otherwise their evaluation entails performing simple integrations as indicated. Formulas have been found for nonlimiting apertures, large defining apertures, and pinhole apertures. Examples of all three types of application are presented. OCIS codes, 050.1220, 050.1960, 120.3940, 120.5630, 260.3090. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Shirley, EL (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 13 TC 27 Z9 27 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1998 VL 37 IS 28 BP 6581 EP 6590 DI 10.1364/AO.37.006581 PG 10 WC Optics SC Optics GA 125ZC UT WOS:000076266800001 PM 18301464 ER PT J AU Early, EA Thompson, EA Disterhoft, P AF Early, EA Thompson, EA Disterhoft, P TI Field calibration unit for ultraviolet spectroradiometers SO APPLIED OPTICS LA English DT Article ID STANDARD LAMPS AB Horizontal standard lamps calibrate the spectral irradiance responsivity of spectroradiometers that measure solar ultraviolet irradiance. A field calibration unit and power supply developed to meet the requirements for using these standards in the field are described and their operation and associated uncertainties are detailed. Results from assessments obtained at two field instrument intercomparisons indicate that the horizontal standard, field calibration unit, and power supply operate within the design tolerances, making them suitable for performing routine calibrations in the field on most ultraviolet spectroradiometers. (C) 1998 Optical Society of America. OCIS codes: 120.5630, 120.3930, 120.4800. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NOAA, Surface Radiat Res Branch, Boulder, CO 80303 USA. RP Early, EA (reprint author), NIST, Opt Technol Div, Bldg 220,Room A-320, Gaithersburg, MD 20899 USA. NR 7 TC 28 Z9 28 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1998 VL 37 IS 28 BP 6664 EP 6670 DI 10.1364/AO.37.006664 PG 7 WC Optics SC Optics GA 125ZC UT WOS:000076266800012 PM 18301475 ER PT J AU Snail, KA Hanssen, LM AF Snail, KA Hanssen, LM TI Magnification of conic mirror reflectometers (vol 37, pg 4143, 1998) SO APPLIED OPTICS LA English DT Correction C1 USN, Res Lab, Washington, DC 20375 USA. NIST, Gaithersburg, MD 20899 USA. RP Snail, KA (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1998 VL 37 IS 28 BP 6695 EP 6695 DI 10.1364/AO.37.006695 PG 1 WC Optics SC Optics GA 125ZC UT WOS:000076266800017 PM 18301480 ER PT J AU Wu, CM Deslattes, RD AF Wu, CM Deslattes, RD TI Analytical modeling of the periodic nonlinearity in heterodyne interferometry SO APPLIED OPTICS LA English DT Article ID POLARIZATION; ERRORS AB The periodic nonlinearity that arises from nonideal laser sources and imperfections of optical components Limits the accuracy of displacement measurements in heterodyne interferometry at the nanometer level. An analytical approach to investigating the nonlinearity is presented. Frequency mixing, polarization mixing, polarization-frequency mixing, and ghost reflections are all included in this investigation. A general form for the measurement signal, including that of the distortions, is given. The analytical approach is also applicable to homodyne interferometry. (C) 1998 Optical Society of America. C1 NIST, Phys Lab, Gaithersburg, MD 20899 USA. Ind Technol Res Inst, Ctr Measurement Standards, Hsinchu, Taiwan. RP Wu, CM (reprint author), NIST, Phys Lab, Bldg 221,Room A141, Gaithersburg, MD 20899 USA. RI Wu, Chien-ming/K-6361-2012 OI Wu, Chien-ming/0000-0002-4985-386X NR 14 TC 74 Z9 80 U1 3 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1998 VL 37 IS 28 BP 6696 EP 6700 DI 10.1364/AO.37.006696 PG 5 WC Optics SC Optics GA 125ZC UT WOS:000076266800018 PM 18301481 ER PT J AU Oates, DE Habib, Y Lehner, C Herd, J Ono, R Vale, L AF Oates, DE Habib, Y Lehner, C Herd, J Ono, R Vale, L TI Modeling the nonlinear surface impedance of high-T-c thin films SO APPLIED SUPERCONDUCTIVITY LA English DT Article ID JOSEPHSON-JUNCTIONS; POWER DEPENDENCE; YBA2CU3O7-X; LOSSES AB To explore the idea that weak links are responsible for power dependence, we have measured and modeled the microwave impedance of fabricated Josephson-junctions, in which we have observed evidence for Josephson-vortex creation and annihilation by the microwave currents. We believe that we have observed long-junction effects in fabricated high-T-c Josephson-junctions and that these are the first observation of microwave-frequency vortex creation. To explain the nonlinear surface impedance of thin films of the high-T-c materials, an extended-coupled-grain model is introduced and discussed. The model incorporates a series array of Josephson-junction defects with a distribution of IcRn products. Comparison with experiments shows good qualitative agreement. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 MIT, Lincoln Lab, Lexington, MA 02420 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. USAF, Rome Lab, Bedford, MA 01731 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Oates, DE (reprint author), MIT, Lincoln Lab, 244 Wood St, Lexington, MA 02420 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD OCT-DEC PY 1998 VL 6 IS 10-12 BP 531 EP 539 PG 9 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 251VE UT WOS:000083466400008 ER PT J AU Li, HQ Ono, RH Rudman, DA Vale, LR Liou, SH AF Li, HQ Ono, RH Rudman, DA Vale, LR Liou, SH TI Multilayer processing of high-T-c films and stacked bicrystal Josephson junctions SO APPLIED SUPERCONDUCTIVITY LA English DT Article ID MAGNETOMETERS AB A new process for making high-temperature superconducting multilayer circuits is reported in detail. Proximity exposure was used to form controllable shallow edges which are required for the crossovers and interconnects. Small features with shallow edges can be achieved by the combination of contact exposure and proximity exposure. Stacked Josephson junctions on STO bicrystal substrates were prepared using this process and tested. A multilayer low-inductance dc-SQUID fabricated using this process shows large voltage modulation. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Nebraska, Lincoln, NE USA. RP Li, HQ (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 11 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD OCT-DEC PY 1998 VL 6 IS 10-12 BP 711 EP 717 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 251VE UT WOS:000083466400033 ER PT J AU Minetti, JL AF Minetti, JL TI Trends and jumps in the annual precipitation in South America, south of the 15 degrees S SO ATMOSFERA LA English DT Article ID CLIMATIC JUMP AB Different types of South American annual precipitation series are analyzed for stations located south of the parallel 15 degrees S. It has been found that the most typical pattern of change in the long-term averages for 30-years consecutive series, corresponding to meteorological stations eastward of the Andes Cordillera, is represented by a. "jump" or discontinuity which, for these stations, is always positive. The maximum signal is spotted between the 1950's and the 1960's, showing the largest values on the continental zone of Argentina's territory. On the other hand, for stations on the windward side of the Andes, in Chile, the change is characterized by a decreasing tendency during the years, being steeper over the Northern dessert. Evidences of impacts produced by these changes are shown and possible physical causes of these long-term changes are inferred. C1 Univ Nacl Tucuman, CONICET, Dept Geog, Fdn Carl C Zon Caldenius,NOAA, RA-4000 San Miguel De Tucuman, Tucuman, Argentina. Univ Buenos Aires, CONICET, Dept Ciencias Atmosfera, Buenos Aires, DF, Argentina. RP Minetti, JL (reprint author), Univ Nacl Tucuman, CONICET, Dept Geog, Fdn Carl C Zon Caldenius,NOAA, RA-4000 San Miguel De Tucuman, Tucuman, Argentina. NR 65 TC 28 Z9 32 U1 1 U2 2 PU CENTRO CIENCIAS ATMOSFERA UNAM PI MEXICO CITY PA CIRCUITO EXTERIOR, MEXICO CITY CU 04510, MEXICO SN 0187-6236 J9 ATMOSFERA JI Atmosfera PD OCT 1 PY 1998 VL 11 IS 4 BP 205 EP 221 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 129UX UT WOS:000076483300002 ER PT J AU Francey, RJ Steele, LP Langenfelds, RL Allison, CE Cooper, LN Dunse, BL Bell, BG Murray, TD Tait, HS Thompson, L Masarie, KA AF Francey, RJ Steele, LP Langenfelds, RL Allison, CE Cooper, LN Dunse, BL Bell, BG Murray, TD Tait, HS Thompson, L Masarie, KA TI Atmospheric carbon dioxide and its stable isotope ratios, methane, carbon monoxide, nitrous oxide and hydrogen from Shetland Isles SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE atmospheric composition; trace gases; latitudinal gradient; ocean sink; network integration ID NORTHERN-HEMISPHERE; GROWTH-RATE; CO2 AB Since November 1992, 0.5 l glass flasks have been filled approximately monthly with dry marine air from Shetland Isles, Scotland (60.2 degrees N, 1.2 degrees W) and transported to CSIRO, Australia for analyses. The Shetland site is part of a CSIRO global flask network with 10-12 sites, anchored to continuous high precision in situ measurements made at the Australian Cape Grim Baseline Station (40.7 degrees S, 144.7 degrees E), a primary station in the Global Atmosphere Watch programme (GAW) coordinated by the World Meteorological Organisation. The methodology is summarised, and Shetland results for CO2, CH4, N2O, CO, H-2 and delta(13)C, delta(18)O of CO2 presented for the period 1992-1996. We compare data to available results from surrounding stations of the NOAA cooperative network tin particular Mace Head, Ireland, 53.3 degrees N, 9.9 degrees W), and address issues of both trace species intercalibration and atmospheric spatial gradients. While considerable uniformity of trace-gas composition is evident in oceanic air over a 13 degrees range of latitude, nevertheless anomalies in CO2 concentration and isotopic composition are suggested in samples representing air to the west of Shetland. The potential for remotely monitoring integrated emissions from northern Europe is also identified. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 CSIRO, Div Atmospher Res, Aspendale, Vic 3195, Australia. Inst Terr Ecol, Edinburgh Res Stn, Penicuik EH26 0QB, Midlothian, Scotland. The Observatory, Lerwick ZE1 0RR, Shetland, Scotland. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Langenfelds, RL (reprint author), CSIRO, Div Atmospher Res, Aspendale, Vic 3195, Australia. RI Steele, Paul/B-3185-2009; Langenfelds, Raymond/B-5381-2012 OI Steele, Paul/0000-0002-8234-3730; NR 28 TC 13 Z9 13 U1 2 U2 10 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 OCT PY 1998 VL 32 IS 19 BP 3331 EP 3338 DI 10.1016/S1352-2310(97)00491-3 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 109WA UT WOS:000075346100015 ER PT J AU Stone, RP Johnson, SW AF Stone, RP Johnson, SW TI Prolonged exposure to mine tailings and survival and reproductive success of ovigerous tanner crabs (Chionoecetes bairdi) SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Stone, RP (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 19 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD OCT PY 1998 VL 61 IS 4 BP 548 EP 556 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 124NA UT WOS:000076187600019 PM 9811962 ER PT J AU Servain, J Busalacchi, AJ McPhaden, MJ Moura, AD Reverdin, G Vianna, M Zebiak, SE AF Servain, J Busalacchi, AJ McPhaden, MJ Moura, AD Reverdin, G Vianna, M Zebiak, SE TI A Pilot Research Moored Array in the Tropical Atlantic (PIRATA) SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SEA-SURFACE TEMPERATURE; GENERAL-CIRCULATION MODEL; NINO SOUTHERN-OSCILLATION; PACIFIC WARM POOL; EQUATORIAL ATLANTIC; NORTHEAST BRAZIL; DECADAL VARIABILITY; MIXED-LAYER; WIND STRESS; OCEAN AB The tropical Atlantic Ocean is characterized by a large seasonal cycle around which there are climatically significant interannual and decadal timescale variations. The most pronounced of these interannual variations are equatorial warm events, somewhat similar to the El Nino events for the Pacific, and the so-called Atlantic sea surface temperature dipole. Both of these phenomena in turn may be related to El Nino-Southern Oscillation variability in the tropical Pacific and other modes of regional climatic variability in ways that are not yet fully understood. PIRATA (Pilot Research Moored Array in the Tropical Atlantic) will address the lack of oceanic and atmospheric data in the tropical Atlantic, which limits our ability to make progress on these important climate issues. The PIRATA array consists of 12 moored Autonomous Temperature Line Acquisition System buoy sites to be occupied during the years 1997-2000 for monitoring the surface variables and upper-ocean thermal structure at key locations in the tropical Atlantic. Meteorological and oceanographical measurements are transmitted via satellite in real time and are available to all interested users in the research or operational communities. The total number of moorings is a compromise between the need to put out a large enough array for a long enough period of time to gain fundamentally new insights into coupled ocean-atmosphere interactions in the region, while at the same time recognizing the practical constraints of resource limitations in terms of funding, ship time, and personnel. Seen as a pilot Global Ocean Observing System/Global Climate Observing System experiment, PIRATA contributes to monitoring the tropical Atlantic in real time and anticipates a comprehensive observing system that could be operational in the region for the 2000s. C1 ORSTOM, Ctr Brest, F-29280 Plouzane, France. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Lamont Doherty Earth Observ, Int Res Inst Climate Predict, Palisades, NY 10964 USA. LEGOS, GRGS, Toulouse, France. INPE, Sao Paulo, Brazil. RP Servain, J (reprint author), ORSTOM, Ctr Brest, BP 70, F-29280 Plouzane, France. EM servain@orstom.fr RI McPhaden, Michael/D-9799-2016; OI Vianna, Marcio/0000-0002-3616-7772 NR 57 TC 131 Z9 133 U1 0 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1998 VL 79 IS 10 BP 2019 EP 2031 DI 10.1175/1520-0477(1998)079<2019:APRMAI>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132PK UT WOS:000076638600001 ER PT J AU Menzel, WP Holt, FC Schmit, TJ Aune, RM Schreiner, AJ Wade, GS Gray, DG AF Menzel, WP Holt, FC Schmit, TJ Aune, RM Schreiner, AJ Wade, GS Gray, DG TI Application of GOES-8/9 soundings to weather forecasting and nowcasting SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VAS; TEMPERATURE; RETRIEVAL; WATER AB Since April 1994 a new generation of geostationary sounders has been measuring atmospheric radiances in 18 infrared spectral bands and thus providing the capability for investigating oceanographic and meteorological phenomena that far exceed those available from the previous generation of Geostationary Operational Environmental Satellites (GOES). Menzel and Purdom foreshadowed many of the anticipated improvements from the GOES-8/9 sounders. This article presents some of the realizations; it details the in-flight performance of the sounder, presents both validated operational. as well as routinely available experimental products, and shows the impact on nowcasting and forecasting activities. For the first time operational hourly sounding products over North America and adjacent oceans are now possible with the GOES-8/9 sounders. The GOES-8/9 sounders are making significant contributions by depicting moisture changes for numerical weather prediction models over the continental United States, monitoring winds over oceans, and supplementing the National Weather Service's Automated Surface Observing System with upper-level cloud information. Validation of many sounding products has been accomplished by comparison with radiosondes and aircraft measurements. Considerable progress has been made toward assimilation of soundings from clear skies and cloud properties in cloudy regions in operational as well as research forecast models; GOES-8/9 moisture soundings are now being used in the operational Eta regional forecast model. C1 NOAA, NESDIS, Off Res & Applicat, Atmospher Res & Applicat Div, Madison, WI 53706 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. RP Menzel, WP (reprint author), NOAA, NESDIS, Off Res & Applicat, Atmospher Res & Applicat Div, 1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011; Wade, Gary S./F-5630-2010; Schmit, Timothy/F-5624-2010; Aune, Robert/F-5572-2010 OI Menzel, W. Paul/0000-0001-5690-1201; Aune, Robert/0000-0002-7778-2739 NR 26 TC 96 Z9 96 U1 1 U2 2 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 OCT PY 1998 VL 79 IS 10 BP 2059 EP 2077 DI 10.1175/1520-0477(1998)079<2059:AOGSTW>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132PK UT WOS:000076638600003 ER PT J AU Ohmura, A Dutton, EG Forgan, B Frohlich, C Gilgen, H Hegner, H Heimo, A Konig-Langlo, G McArthur, B Muller, G Philipona, R Pinker, R Whitlock, CH Dehne, K Wild, M AF Ohmura, A Dutton, EG Forgan, B Frohlich, C Gilgen, H Hegner, H Heimo, A Konig-Langlo, G McArthur, B Muller, G Philipona, R Pinker, R Whitlock, CH Dehne, K Wild, M TI Baseline Surface Radiation Network (BSRN/WCRP): New precision radiometry for climate research SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID CONTINUUM ABSORPTION; IRRADIANCE; SYSTEM; MODEL AB To support climate research, the World Climate Research Programme (WCRP) initiated a new radiometric network, the Baseline Surface Radiation Network (BSRN). The network aims at providing validation material for satellite radiometry and climate models. It further aims at detecting long-term variations in irradiances at the earth's surface, which are believed to play an important role in climate change. The network and its instrumentation are designed 1) to cover major climate zones, 2) to provide the accuracy required to meet the objectives, and 3) to ensure homogenized standards for a long period in the future. The limits of the accuracy are defined to reach these goals. The suitable instruments and instrumentations have been determined and the methods for observations and data management have been agreed on at all stations. Measurements of irradiances are at 1 Hz, and the 1-min statistics (mean, standard deviation, and extreme values) with quality flags are stored at a centralized data archive at the WCRP's World Radiation Monitoring Center (WRMC) in Zurich, Switzerland. The data are quality controlled both at stations and at the WRMC. The original 1-min irradiance statistics will be stored at the WRMC for 10 years, while hourly mean values will be transferred to the World Radiation Data Center in St. Petersburg, Russia. The BSRN, consisting of 15 stations, covers the earth's surface from 80 degrees N to 90 degrees S, and will soon be joined by seven more stations. The data are available to scientific communities in various ways depending on the communication environment of the users. The present article discusses the scientific base, organizational and technical aspects of the network, and data retrieval methods; shows various application possibilities; and presents the future tasks to be accomplished. C1 ETH Zurich, Inst Geog, CH-8057 Zurich, Switzerland. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Bur Meteorol, Melbourne, Vic, Australia. Phys Meteorol Observ, World Radiat Ctr, Davos, Switzerland. Swiss Meteorol Inst, Payerne Aerol Stn, Payerne, Switzerland. Alfred Wegener Inst Polar & Marine Res, D-2850 Bremerhaven, Germany. Atmospher Environm Serv, Downsview, ON, Canada. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Deutsch Wetterdienst, Observ Potsdam, Potsdam, Germany. RP Ohmura, A (reprint author), ETH Zurich, Inst Geog, Winterthurerstr 190, CH-8057 Zurich, Switzerland. EM ohmura@geo.umnw.ethz.ch RI Pinker, Rachel/F-6565-2010; Wild, Martin/J-8977-2012; Konig-Langlo, Gert/K-5048-2012 OI Konig-Langlo, Gert/0000-0002-6100-4107 NR 42 TC 445 Z9 450 U1 4 U2 31 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 OCT PY 1998 VL 79 IS 10 BP 2115 EP 2136 DI 10.1175/1520-0477(1998)079<2115:BSRNBW>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132PK UT WOS:000076638600006 ER PT J AU Lynn, RJ Baumgartner, T Garcia, J Collins, CA Hayward, TL Hyrenbach, KD Mantyla, AW Murphree, T Shankle, A Schwing, FB Sakuma, KM Tegner, MJ AF Lynn, RJ Baumgartner, T Garcia, J Collins, CA Hayward, TL Hyrenbach, KD Mantyla, AW Murphree, T Shankle, A Schwing, FB Sakuma, KM Tegner, MJ TI The state of the California current, 1997-1998: Transition to El Nino conditions SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID CIRCULATION; DECLINES; PACIFIC; PERIOD; EVENTS AB This report, part of a continuing series of annual reports describing oceanographic conditions in the coastal waters of the Californias, emphasizes the 1997-98 period, The coastal waters of the Californias were strongly influenced by El Nino conditions beginning late in the summer of 1997 and continuing into the summer of 1998, Timely prediction of the onset of this event made it possible for several research programs to augment their observation programs. We review the pattern of atmospheric forcing and changes in the tropical ocean and note the initial impacts upon the California Current system, Sampling being done by the CalCOFI (California Cooperative Oceanic Fisheries Investigations) program is described, and recent data are summarized and interpreted, Data from several other programs including oceanographic sampling off Baja California and central California, and coastal data from buoys, shore stations, and diving programs in kelp forests are reported, There were large and rapid changes in atmospheric forcing and in the upper ocean temperature and salinity distribution and circulation pattern. The pelagic ecosystem was strongly influenced; cruise mean macrozooplankton abundance during the spring of 1998 was the lowest in the 50-year CalCOFI time series. Large changes in the range and abundance of plankton and fish populations were observed. El Nino-induced changes must also be considered in the context of changes on other space-time scales, and the relation of El Nino-related changes and secular trends seen since the mid-1970s regime shift will merit particular attention. C1 Natl Marine Fisheries Serv, NOAA, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Lynn, RJ (reprint author), Natl Marine Fisheries Serv, NOAA, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. EM ron.lynn@noaa.gov NR 36 TC 75 Z9 78 U1 0 U2 5 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1998 VL 39 BP 25 EP 49 PG 25 WC Fisheries SC Fisheries GA 149GF UT WOS:000077596200003 ER PT J AU Brodziak, J AF Brodziak, J TI Revised biology and management of long-finned squid (Loligo pealei) in the northwest Atlantic SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID GROWTH INCREMENTS; SEXUAL MATURITY; STATOLITH; AGE; CEPHALOPODA; MOLLUSCA AB New biological information on the growth and life cycle of the long-finned squid (Loligo pealei) became available as ageing procedures based on statoliths were applied to this valuable commercial resource in the 1990s. It was found that L, pealei grew very rapidly and completed its life cycle in less than one year. This research led to several important changes in management for the L. pealei fishery. First, biological reference points were developed for summer- and winter-hatched squid based on differences in growth and maturation rates between seasonal cohorts. Second, a precautionary approach was taken toward determining the annual allowable catch and long-term potential yield. The revised estimate of long-term potential yield of 21,000 metric tons (t) based on a life span of less than one year was less than half of the previous estimate of 44,000 t, which was based on an assumed life span of roughly two years. Third, limited entry was applied to the commercial squid fishery because the stock was fully exploited on the basis of the revised estimate of long-term potential yield. The Mid-Atlantic Fishery Management Council has set the current annual domestic allowable harvest oil. pealei to equal the revised estimate of long-term potential yield, and in-season monitoring of landings and enforcement of the domestic allowable harvest level have been planned. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Brodziak, J (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. NR 57 TC 10 Z9 11 U1 0 U2 1 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1998 VL 39 BP 61 EP 70 PG 10 WC Fisheries SC Fisheries GA 149GF UT WOS:000077596200006 ER PT J AU Hatfield, E Des Clers, S AF Hatfield, E Des Clers, S TI Fisheries management and research for Loligo gahi in the Falkland Islands SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID LONG-FINNED SQUID; POPULATION-STRUCTURE; VULGARIS-REYNAUDII; LIFE-HISTORY; DORBIGNY; GROWTH; ATLANTIC; STOCKS; PEALEI; WATERS AB Two squid species have been the subject of targeted fisheries in the southwest Atlantic since the early 1980s. The two fisheries have been managed in Falkland Islands waters since 1987 and provide an annual License revenue to the Falkland Islands government equivalent to some $35 (U.S.) million. The real-time assessment of the two species, Loligo gahi and Illex argentinus, is based on the Leslie-DeLury assessment model. The model assumes a single recruitment event before the start of the period used in fitting the model, and a closed population during the period. Early research on the demography and distribution of the Falkland Islands L. gahi population demonstrated ontogenetic descent with a probable associated coastward spawning migration. The L, gahi fishery concentrates by area and does not follow the migration pattern, indicating that the closed population assumption of the assessment model is invalid for much of the period assessed. Research has confirmed the variable nature of recruitment of microcohorts to the fishery overstretching the single-recruitment assumption of the Leslie-DeLury model. But research has also shown that there are periods of residency of L. gahi on the fishing grounds. The current assessment procedure uses these periods of residency to derive estimates of population depletion and therefore stock size. In this paper the salient features of the fishery for L, gahi are presented, and the crucial links between resource assessment, biological research, and management advice are discussed. Finally, directions for further research, needed to refine assessments and achieve some predictability of population processes, are identified. C1 British Antarctic Survey, NERC, Cambridge CB3 0ET, England. RP Hatfield, E (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 37 TC 39 Z9 39 U1 1 U2 3 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1998 VL 39 BP 81 EP 91 PG 11 WC Fisheries SC Fisheries GA 149GF UT WOS:000077596200008 ER PT J AU Carls, MG Marty, GD Meyers, TR Thomas, RE Rice, SD AF Carls, MG Marty, GD Meyers, TR Thomas, RE Rice, SD TI Expression of viral hemorrhagic septicemia virus in prespawning Pacific herring (Clupea pallasi) exposed to weathered crude oil SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID EXXON-VALDEZ OIL; PRINCE-WILLIAM-SOUND; PETROLEUM-HYDROCARBONS; MARINE FISH; SPILL; SEDIMENTS; HISTOPATHOLOGY; SEAWATER; TISSUES; ALASKA AB Expression of subclinical viral infection in response to toxicant exposure has not previously been reported, but evidence presented herein indicates that activation of viral hemorrhagic septicemia virus (VHSV) may occur in Pacific herring (Clupea pallasi) exposed to crude oil encountered after an oil spill. Decreased incidence of hepatic inflammatory cells as a function of total polynuclear aromatic hydrocarbon (TPAH) concentration was evidence for immunosuppression in exposed fish, and decreased immune surveillance is a possible mechanism by which subclinical VHSV could be reactivated. Adult Pacific herring of unknown status regarding infection by VHSV were captured from the wild and exposed to weathered crude oil for 16-18 days. TPAH concentration in tissue, VHSV prevalence, and mortality were correlated with dose. Histopathologic lesions were significantly correlated with TPAH concentration and prevalence of VHSV, but not gender or length. Significant lesions included increased hepatocelIular necrosis, splenic thrombosis, and decreased inflammation in the liver. C1 NOAA, Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Calif Davis, Sch Vet Med, Dept Anat Physiol & Cell Biol, Davis, CA 95616 USA. Alaska Dept Fish & Game, Juneau Fish Pathol Lab, CFMD Div, Juneau, AK 99802 USA. Calif State Univ Chico, Dept Biol Sci, Chico, CA 95959 USA. RP Carls, MG (reprint author), NOAA, Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM mark.carls@noaa.gov NR 30 TC 25 Z9 27 U1 1 U2 7 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 OCT PY 1998 VL 55 IS 10 BP 2300 EP 2309 DI 10.1139/cjfas-55-10-2300 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 143KA UT WOS:000077253300010 ER PT J AU Steele, KE Wang, DW Earle, MD Michelena, ED Dagnall, RJ AF Steele, KE Wang, DW Earle, MD Michelena, ED Dagnall, RJ TI Buoy pitch and roll computed using three angular rate sensors SO COASTAL ENGINEERING LA English DT Article DE measurements; instruments, accelerometers, inclinometers, magnetometers; mathematical methods, algorithms, data processing, Fourier Analysis, iterative methods,; mathematical transformations; waves, ocean waves, surface waves; marine environment ID WAVE AB The National Data Buoy Center (NDBC), a part of the US National Weather Service (NWS), operates networks of data buoys. Each buoy measures, and reports to shore each hour, air temperature, water temperature, barometric pressure, wind speed, wind direction, and nondirectional wave data. Some 15 discus-type buoys report directional wave data each hour. The systems aboard these buoys apply measurement and analysis techniques that require time-series records of hull east and north slopes, which are, in turn, based on measurements of hull bow azimuth, pitch, and roll. Pitch and roll are normally measured on NDBC hulls using the Datawell (Netherlands) Hippy 40 model sensor. Time-series records of pitch and roll thus measured are stored in the onboard computer memory of a wave processing module. These pitch and roll records are used in conjunction with hull azimuth and heave acceleration time series to compute directional wave data. The Hippy 40 heave, pitch, roll sensor consumes little power, is reliable when handled correctly, and provides sufficiently accurate measurements of pitch and roll. On the other hand, it is heavy, large, requires special handling, and is expensive. Thus, NDBC needs an alternative basis for the measurement of hull pitch and roll. In recent years, low-cost, solid-state angular rate sensors have become available. Three of these small, inexpensive sensors, when mounted orthogonally in a buoy, can produce estimates of the body-fixed components of the angular velocity vector. From the time-series outputs of these sensors aboard a discus hull, there are mathematical means to produce time-series records of wave-frequency pitch and roll relative to mean pitch and roll. Other sensors provide mean values of pitch and roll, so that by summing, instantaneous total hull pitch and roll records can be produced. The NDBC existing onboard-buoy wave processing module (WPM) system can process these total pitch and roll records just as if they had come from a Hippy 40, so that little change to NDBC's existing WPM hardware/software, or to the shore-based supporting software, is necessary to produce a new directional wave measurement system based on angular rate sensors. This paper describes the techniques NDBC is employing to produce wave-frequency pitch and roll relative to mean pitch and roll, and the necessary additional sensors needed to determine mean pitch and mean roll. The validity of these techniques is demonstrated by comparing pitch and roll records resulting from their application to pitch and roll records taken directly from the Hippy 40. NDBC's plans for the employment of this new pitch-roll measuring technique in a modified WPM system are summarized. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. Comp Sci, Stennis Space Ctr, MS 39529 USA. Neptune Sci, Reston, VA 20190 USA. RP Steele, KE (reprint author), Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. NR 8 TC 12 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3839 J9 COAST ENG JI Coast. Eng. PD OCT PY 1998 VL 35 IS 1-2 BP 123 EP 139 DI 10.1016/S0378-3839(98)00025-8 PG 17 WC Engineering, Civil; Engineering, Ocean SC Engineering GA 140UY UT WOS:000077107800008 ER PT J AU Wainwright, TC Waples, RS AF Wainwright, TC Waples, RS TI Prioritizing Pacific salmon stocks for conservation: Response to Allendorf et al. SO CONSERVATION BIOLOGY LA English DT Editorial Material ID TRENDS C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. RP Wainwright, TC (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fishery Anal & Monitoring Div, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM Thomas.Wainwright@NOAA.gov RI Wainwright, Thomas/F-4550-2010; Waples, Robin/K-1126-2016 OI Wainwright, Thomas/0000-0001-5147-479X; NR 18 TC 7 Z9 7 U1 1 U2 4 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 1998 VL 12 IS 5 BP 1144 EP 1147 DI 10.1046/j.1523-1739.1998.97385.x PG 4 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 126BL UT WOS:000076272800030 ER PT J AU Henderson, LO Marti, GE Gaigalas, A Hannon, WH Vogt, RF AF Henderson, LO Marti, GE Gaigalas, A Hannon, WH Vogt, RF TI Terminology and nomenclature for standardization in quantitative fluorescence cytometry SO CYTOMETRY LA English DT Article; Proceedings Paper CT Conference on Quantitative Immunofluorescence Measurement CY NOV, 1997 CL OTTAWA, CANADA DE flow cytometry; fluorescence intensity; molecules of equivalent soluble fluorochrome; MESF; antibody binding capacity; ABC; cell receptors; quality control; standardization AB Terminology in any field is a complex mix of established conventions, accepted usages, disputed terms, and occasional misnomers. The terminology that has evolved for quantitative fluorescence cytometry (QFCM) is especially multifarious, in part because QFCM encompasses a range from subjective visual assessments to objective photon counts. Thus, while descriptive terms such as "dim" and "bright" are still quite useful, quantitative terms such as "binding capacity" should be used with collective understanding of their exact meanings. This article reviews current usage and proposes definitions that, with refinement from suppliers and users of QFCM technology, can provide the required clarity (C) 1998 Wiley-Liss,Inc.(dagger). C1 Ctr Dis Control & Prevent, Natl Diabet Reference Lab, Atlanta, GA USA. US FDA, Ctr Biol Evaluat & Res, Bethesda, MD USA. NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Vogt, RF (reprint author), Mailstop F19, Atlanta, GA 30341 USA. EM rfv1@cdc.gov NR 11 TC 36 Z9 36 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-4763 J9 CYTOMETRY JI Cytometry PD OCT 1 PY 1998 VL 33 IS 2 BP 97 EP 105 DI 10.1002/(SICI)1097-0320(19981001)33:2<97::AID-CYTO3>3.0.CO;2-H PG 9 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 124WL UT WOS:000076205700002 PM 9773869 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Control of Cd concentrations in a coastal diatom by interactions among free ionic Cd, Zn, and Mn in seawater SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID NATURAL ORGANIC-LIGANDS; CENTRAL NORTH PACIFIC; MARINE-PHYTOPLANKTON; PHYTOCHELATIN PRODUCTION; SARGASSO SEA; CADMIUM; ZINC; LIMITATION; MANGANESE; TRANSPORT AB Cadmium and phosphate concentrations in seawater are closely correlated, suggesting that Cd distributions, like those of PO4, are controlled by algal uptake and regeneration. But the factors controlling Cd levels in phytoplankton are poorly known. Experiments in metal ion buffer systems with a coastal diatom Thalassiosira pseudonana revealed that cellular Cd:C ratios within the Cd ion concentration ([Cd2+]) range (10(-13) to 10(-10) M) in, seawater were generally proportional to [Cd2+] and inversely related to concentrations of Zn and Mn ions ([Zn2+] and [Mn2+]) and specific growth rate. The effects of Mn and Zn reflect cellular uptake of Cd by two inducible transport systems: the Mn system whose capacity (V-max) is enhanced at low [Mn2+] and a separate system induced at low cellular zinc. At the low [Zn2+] of surface oceanic waters (less than or equal to 10(-11.0) M), Cd uptake is controlled by this latter system and, therefore, is inversely related to ionic zinc levels. However, at the higher [Zn2+] range of coastal waters, Cd uptake by this system is strongly suppressed and Cd instead is taken up by the Mn system; as a result it is inversely related to [Mn2+] and largely independent of variations in [Zn2+]. Because of the suppression of Cd uptake by high [Zn2+] and [Mn2+] in coastal waters, algal Cd concentrations may be lower in these waters than in the ocean despite the presence of higher coastal [Cd2+]. C1 NOAA, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. RP Sunda, WG (reprint author), NOAA, Natl Marine Fisheries Serv, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 35 TC 53 Z9 54 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT 1 PY 1998 VL 32 IS 19 BP 2961 EP 2968 DI 10.1021/es980271y PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 125DR UT WOS:000076222600042 ER PT J AU Begg, GA Cappo, M Cameron, DS Boyle, S Sellin, MJ AF Begg, GA Cappo, M Cameron, DS Boyle, S Sellin, MJ TI Stock discrimination of school mackerel, Scomberomorus queenslandicus, and spotted mackerel, Scomberomorus munroi, in coastal waters of eastern Australia by analysis of minor and trace elements in whole otoliths SO FISHERY BULLETIN LA English DT Article ID ELECTRON-PROBE MICROANALYSIS; SOUTHEASTERN UNITED-STATES; LASER-ABLATION ICPMS; KING MACKEREL; IDENTIFICATION; MICROCHEMISTRY; CAVALLA; AGE; AID AB The concentrations of 11 elements in individual whole sagittal otoliths from school mackerel (Scomberomorus queenslandicus) and spotted mackerel (Scomberomorus munroi) collected in east coast waters of Queensland, Australia (16 degrees S to 28 degrees S) were determined by using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Spatial and ontogenetic variation in otolith elemental composition was examined to make inferences about the stock structure of these species. Stepwise canonical discriminant analyses of the concentrations of barium, potassium, magnesium, manganese, sodium, phosphorus, sulphur, and strontium were used to differentiate groups of fish. These analyses identified an optimum grouping of at least two stocks of school mackerel and a single stock of spotted mackerel in the study region, although our results showed that the most informative comparisons were made among fish of the same year class. The age of fish in collected samples produced strongly significant effects on mean elemental composition of otoliths. These patterns offered independent support for hypotheses about stock structure from previous tagging, catch monitoring, ageing, and reproductive studies. Discrimination between school and spotted mackerel stocks will enable the species to be managed on the basis of stock structure throughout their east coast distribution. C1 Univ Queensland, Dept Zool, St Lucia, Qld 4072, Australia. Australian Inst Marine Sci, Townsville, Qld 4810, Australia. Queensland Dept Primary Ind, So Fisheries Ctr, Deception Bay, Qld 4508, Australia. RP Begg, GA (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, NOAA, 166 Water St, Woods Hole, MA 02543 USA. EM Gavin.Begg@noaa.gov NR 35 TC 30 Z9 32 U1 1 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 653 EP 666 PG 14 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400001 ER PT J AU Cooper, JA Chapleau, F AF Cooper, JA Chapleau, F TI Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification SO FISHERY BULLETIN LA English DT Article ID REASSESSMENT; FLATFISH; PISCES AB A cladistic analysis of interrelationships for 53 (of 59) pleuronectid species was performed by using 106 morphological and osteological characters. The analysis resulted in 128 equally parsimonious cladograms (heuristic search, 403 steps, consistency index=0.33, retention index=0.79). A 50% majority-rule consensus cladogram indicated that only five of 47 resolved nodes were observed in less than 100% of the cladograms. These five nodes are restricted to interrelationships within one subfamily. The Pleuronectidae is monophyletic according to ten synapomorphies. In addition, five subfamilies were defined: Hippoglossinae, Eopsettinae Lyopsettinae, Hippoglossoidinae, and Pleuronectinae. The largest subfamily, the Pleuronectinae, was further subdivided into four tribes: Psettichthyini, Isopsettini, Microstomini, and Pleuronectini. The interrelationships established within Pleuronectidae provide a strong foundation for a simplified yet phylogenetically informative taxonomic nomenclature at the genus-group level. The following genera are reclassified: Atherestes and Reinhardtius to Reinhardtius; Errex, Glyptocephalus, and Tanakius to Glyptocephalus; Embassichthys, and Microstomus to Microstomus; Hypsopsetta and Pleuronichthys to Pleuronichthys; and Kareius and Platichthy to Platichthys. To preserve the monophyletic status of Eopsetta, E. exilis was reassigned to the genus Lyopsetta (Lyopsettinae). The genus Pleuronectes (as defined by Sakamoto in 1984) was found to be polyphyletic. Monophyly of this genus is established by revising it to include only five species; Pleuronectes glacialis, P. pinnifasciatus, P. platessus, P. putnami, and P. quadrituberculatus. Other species, formerly placed in Pleuronectes, are now reclassified to Isopsetta, Limanda, Parophrys, Psettichthys, and Pseudopleuronectes. The monophyletic status of Limanda (six species) is uncertain because of unresolved relationships between these species and other taxa in the tribe Pleuronectini. C1 Natl Marine Fisheries Serv, Systemat Lab, Museum Hist Nat, Washington, DC 20560 USA. Univ Ottawa, Fac Sci, Ottawa Carleton Inst Biol, Ottawa, ON K1N 6N5, Canada. RP Cooper, JA (reprint author), Natl Marine Fisheries Serv, Systemat Lab, Museum Hist Nat, Washington, DC 20560 USA. EM cooper.andrew@nmnh.si.edu NR 54 TC 76 Z9 92 U1 1 U2 11 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 686 EP 726 PG 41 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400003 ER PT J AU Cox, TM Read, AJ Barco, S Evans, J Gannon, DP Koopman, HN McLellan, WA Murray, K Nicolas, J Pabst, DA Potter, CW Swingle, WM Thayer, VG Touhey, KM Westgate, AJ AF Cox, TM Read, AJ Barco, S Evans, J Gannon, DP Koopman, HN McLellan, WA Murray, K Nicolas, J Pabst, DA Potter, CW Swingle, WM Thayer, VG Touhey, KM Westgate, AJ TI Documenting the bycatch of harbor porpoises, Phocoena phocoena, in coastal gillnet fisheries from stranded carcasses SO FISHERY BULLETIN LA English DT Article ID NET AB We examined 107 harbor porpoise (Phocoena phocoena) carcasses recovered from beaches in Maryland, Virginia, and North Carolina between 1994 and 1996 for evidence of entanglement in fishing gear. Stranded porpoises ranged in length from 102 to 128 cm, indicating that only juvenile porpoises are present in the nearshore waters of the Mid-Atlantic during winter. Of the 40 porpoises for which we could establish cause of death, 25 displayed definitive evidence of entanglement in fishing gear. Evidence of entanglement consisted primarily of line marks from nets; in four cases we were able to determine specifically that porpoises had become entangled in monofilament nets. These mortalities demonstrate the need for a directed observer program for coastal gillnet fisheries in the Mid-Atlantic. C1 Duke Univ, Marine Lab, Nicholas Sch Environm, Beaufort, NC 28516 USA. Virginia Marine Sci Museum, Virginia Beach, VA 23451 USA. Maryland Dept Nat Resources, Fisheries Serv, Cooperat Oxford Lab, Oxford, MD 21654 USA. Univ N Carolina, Wilmington, NC 28403 USA. NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. RP Cox, TM (reprint author), Duke Univ, Marine Lab, Nicholas Sch Environm, 135 Duke Marine Lab Rd, Beaufort, NC 28516 USA. NR 12 TC 21 Z9 24 U1 4 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 727 EP 734 PG 8 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400004 ER PT J AU Laidig, TE Sakuma, KM AF Laidig, TE Sakuma, KM TI Description of pelagic larval and juvenile grass rockfish, Sebastes rastrelliger (family Scorpaenidae), with an examination of age and growth SO FISHERY BULLETIN LA English DT Article ID OREGON; FLAVIDUS; MELANOPS AB Pigmentation patterns, meristic characters, morphometric measurements, and head spination were recorded and illustrated for the developmental series of larval and pelagic juvenile (10.0-27.7 mm SL) grass rockfish, Sebastes rastrelliger. Larvae were identified by the presence of strong dorsal and postanal ventral midline pigment and by the presence of pigment on the lateral midline. Juveniles became highly pigmented over most of their body and fin surfaces at a length of 27.7 mm. Pigment patterns were sufficiently distinct and consistent to differentiate larval and juvenile S. rastrelliger from other Sebastes species occurring off central California. Otolith characters were also useful in identification of this species. Larval and juvenile S. rastrelliger grew at a rate of 0.36 mm/day, similar to the growth rates observed in other species of Sebastes. C1 Natl Marine Fisheries Serv, Tiburon Lab, SW Fisheries Sci Ctr, Tiburon, CA 94920 USA. RP Laidig, TE (reprint author), Natl Marine Fisheries Serv, Tiburon Lab, SW Fisheries Sci Ctr, Tiburon, CA 94920 USA. NR 22 TC 9 Z9 9 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 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 788 EP 796 PG 9 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400009 ER PT J AU McGovern, JC Wyanski, DM Pashuk, O Manooch, CS Sedberry, GR AF McGovern, JC Wyanski, DM Pashuk, O Manooch, CS Sedberry, GR TI Changes in the sex ratio and size at maturity of gag, Mycteroperca microlepis, from the Atlantic coast of the southeastern United States during 1976-1995 SO FISHERY BULLETIN LA English DT Article ID VERMILION SNAPPER; RHOMBOPLITES AURORUBENS; EPINEPHELUS-GUTTATUS; SPAWNING FREQUENCY; SOUTH-CAROLINA; EASTERN GULF; LIFE-HISTORY; RED PORGY; SERRANIDAE; PISCES AB Gag, Mycteroperca microlepis, is a large, slow-growing protogynous grouper that probably makes annual migrations to specific locations to aggregate for spawning. During 1976-82, male gag constituted 19.6% of the sexually mature individuals taken during fishery-dependent and fishery-independent sampling along the southeast coast of the United States. A similar percentage of males was found in the Gulf of Mexico from 1977 to 1980; however, males made up only 1.9% of the population in the Gulf of Mexico during 1992. To assess the current sex ratio of gag along the southeast U.S. coast. an emergency rule was enacted by the Department of Commerce in January 1995 that required commercial vessels from North Carolina to southeast Florida to land gag with gonads intact. Histological examination of 2613 gonads of sexually mature gag collected from 18 January through 18 April 1995 revealed that 5.5% of the gag from the southeast Atlantic were male. There was a weak trend indicating that females reached maturity at a smaller size in 1994-95 than in 1976-82. Very few transitional specimens were collected during the spawning season. Most transitional individuals (79%) were taken during April through June immediately after the 1995 spawning season. Gag in spawning condition were landed during December through mid-May by fishermen working offshore from North Carolina to southeast Florida. In addition, gag in spawning condition were taken during research cruises documenting the occurrence of spawning north of Florida (off South Carolina and Georgia at depths ranging from 49 to 91 m). C1 S Carolina Dept Nat Resources, Marine Resources Res Inst, Charleston, SC 29422 USA. Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, NOAA, Beaufort, NC 28516 USA. RP McGovern, JC (reprint author), S Carolina Dept Nat Resources, Marine Resources Res Inst, POB 12559, Charleston, SC 29422 USA. EM mcgovernj@mrd.dnr.state.sc.us NR 31 TC 84 Z9 85 U1 1 U2 16 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 797 EP 807 PG 11 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400010 ER PT J AU Scoles, DR Collette, BB Graves, JE AF Scoles, DR Collette, BB Graves, JE TI Global phylogeography of mackerels of the genus Scomber SO FISHERY BULLETIN LA English DT Article ID EARLY LIFE-HISTORY; MITOCHONDRIAL-DNA; ATLANTIC MACKEREL; POPULATION-STRUCTURE; GENETIC-DIVERGENCE; PACIFIC-OCEAN; RESTRICTION ENDONUCLEASES; NUCLEOTIDE SUBSTITUTIONS; REEF FISHES; TUNA AB Inter- and intraspecific genetic relationships among and within three species of mackerels of the genus Scomber were investigated by restriction site analysis of the whole mitochondrial (mt) DNA genome and direct sequence analysis of the mitochondrial cytochrome b gene. A total of 15 samples, averaging 19 individuals each, were collected from geographically isolated populations throughout the ranges of S. scombrus (two samples), S, australasicus (five samples), and S. japonicus (eight samples). Restriction site analysis with 12 restriction enzymes revealed substantial genetic variation within each species. Sample haplotype diversities ranged from 0.28 to 0.95, and nucleotide sequence diversities from 0.13% to 0.76%. Spatial partitioning of genetic variation was observed in each of the species. Eastern and western North Atlantic samples of S. scombrus exhibited significant heterogeneity in the distribution of mtDNA haplotypes, but no fixed restriction site differences were observed between samples. Similarly, no fixed restriction site differences occurred among samples of S. japonicus in the Atlantic Ocean, although there were significant differences in the distribution of haplotypes among samples. In contrast, samples of S. japonicus from within the Pacific Ocean were characterized by fixed restriction site differences. North and South Pacific samples of S. australasicus were highly divergent, and one of two divergent mtDNA matrilines was restricted to samples from the South Pacific. A 420-bp segment of the cytochrome b gene was sequenced for representatives of each of the major mtDNA lineages identified by restriction site analysis. Scomber scombrus differed from S. australasicus and S. japonicus by more than 11% net nucleotide sequence divergence, considerably greater than the 3.5% sequence divergence between S. australasicus and S. japonicus. Levels of interspecific genetic divergences based on restriction site data were similar in pattern, but were approximately 20% lower in magnitude when based on the cytochrome b sequences. Parsimony analysis and neighbor-joining of restriction site data, and parsimony analysis of cytochrome b sequences showed similar paraphyletic patterns in both S, japonicus and S. australasicus. Levels of divergence among samples of S. japonicus were similar to those between samples of S. australasicus and S. japonicus. Complete partitioning of halpotypes among some samples of S. japonicus that are morphologically distinct suggests that Atlantic and Indo-Pacific populations of S. japonicus may need to be recognized as separate species. C1 Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. Natl Marine Fisheries Serv, Natl Systemat Lab, NOAA, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Scoles, DR (reprint author), Univ Calif Los Angeles, Sch Med, Cedars Sinai Med Ctr, Div Neurol,Neurogenet Lab, 8700 Beverly Blvd, Los Angeles, CA 90048 USA. EM scolesd@csmc.edu NR 69 TC 45 Z9 47 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 823 EP 842 PG 20 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400012 ER PT J AU Sol, SY Olson, OP Lomax, DP Johnson, LL AF Sol, SY Olson, OP Lomax, DP Johnson, LL TI Gonadal development and associated changes in plasma reproductive steroids in English sole, Pleuronectes vetulus, from Puget Sound, Washington SO FISHERY BULLETIN LA English DT Article ID PAROPHRYS-VETULUS; WINTER FLOUNDER; OOCYTE MATURATION; SEASONAL-CHANGES; TELEOST FISHES; RAINBOW-TROUT; SUCCESS; 17-ALPHA,20-BETA-DIHYDROXY-4-PREGNEN-3-ONE; DIFFERENTIATION; AMERICANUS AB Gonadal development, and associated changes in reproductive parameters were investigated in adult female and male English sole (Pleuronectes vetulus) in Puget Sound to provide baseline data for future research on effects of contaminants on reproductive endocrine function in this species. Changes in gonadal histology, gonadosomatic index (GSI), and plasma reproductive steroids (female: 17 beta-estradiol [E2], testosterone [T]; male: T, 11-ketotestosterone [11KT]) were monitored throughout the spawning season. Female sole sampled July through early September were primarily regressed or previtellogenic and had low GSI and plasma steroid levels. GSI and plasma steroid levels were also low in male sole sampled during this time, but the majority had already entered spermatogenesis and, in some fish, production of mature sperm was observed. Fish sampled in October were in the early stages of vitellogenesis and spermiogenesis and showed increases in GSI and plasma steroid levels. By November, about 50% of female fish had entered vitellogenesis and about 30% of males were producing sperm. Proportions of vitellogenic females and sperm-producing males continued to increase through January, with significant numbers of spawning females and males present in February. By late March, the majority of both sexes were spent. Vitellogenic female sole had the highest plasma E2 levels, vitellogenic sole with hydrated oocytes had the highest GSI, and spawning female sole had the highest plasma T levels. Plasma T, 11KT, and GSI were highest in spawning male sole. Reproductive parameters returned to baseline levels in spawned out female and male sole. A potent maturation-inducing steroid (MIS) in many species of teleosts, 17 alpha,20 beta-dihydroxy-4-pregnen-3-one, was not detected in spawning English sole. Additional research is needed to identify the MIS in English sole and to understand better the hormonal regulation of early gonadal development in male sole. C1 Natl Marine Fisheries Serv, Environm Conservat Div, NW Fisheries Sci Ctr, NOAA, Seattle, WA 98112 USA. RP Sol, SY (reprint author), Natl Marine Fisheries Serv, Environm Conservat Div, NW Fisheries Sci Ctr, NOAA, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 44 TC 27 Z9 31 U1 1 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 859 EP 870 PG 12 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400014 ER PT J AU Somerton, DA Donaldson, W AF Somerton, DA Donaldson, W TI Parasitism of the golden king crab, Lithodes aequispinus, by two species of snailfish, genus Careproctus SO FISHERY BULLETIN LA English DT Article ID LIPARID FISH; TEMPERATURE; DECAPODA; ANOMURA; GROWTH; TIME; EGGS AB Along the continental slope of the eastern Bering Sea, two species of Careproctus snailfishes deposit eggs within the branchial chambers of the commercially important golden king crab (Lithodes aequispinus). The larger of the two species is the pink snailfish (C. furcellus); the smaller species is an undescribed species referred to as the red snailfish. According to 1982 trawl survey data, incidence of snailfish eggs and larvae within crab branchial chambers increases with carapace length (CL) and is greater for male than female crabs. A logistic model fitted to the incidence data predicts that a 140-mm-CL male will have an incidence of 0.52, approximately 1.9 times greater than the incidence for a 100-mm male. Incidence for a 100-mm-CL male is approximately 1.9 times greater than that for a female of equal size. On the basis of developmental stages of embryos carried by female golden king crab and the developmental stages of snailfish embryos within a female's branchial chambers, snailfish appear to deposit eggs preferentially in crabs that are early in their molt cycle. The presence of the egg masses results in gill compression, localized necrosis of gill tissue and, in extreme cases, total loss of gill tissue on one side of the body. For crabs of commercial size, the presence of eggs and larvae increases mortality within the holds of fishing Vessels by 35%. The current incidence of eggs and larvae in commercial sized males, however, is so low that the effect on the commercial fishery is considered to be small. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, NOAA, Seattle, WA 98115 USA. Alaska Dept Fish & Game, Kodiak, AK USA. RP Somerton, DA (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, NOAA, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 23 TC 24 Z9 30 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 871 EP 884 PG 14 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400015 ER PT J AU Stoner, AW Ray-Culp, M O'Connell, SM AF Stoner, AW Ray-Culp, M O'Connell, SM TI Settlement and recruitment of queen conch, Strombus gigas, in seagrass meadows: Associations with habitat and micropredators SO FISHERY BULLETIN LA English DT Article ID SP-I LARVAE; POPULATION-STRUCTURE; BIOLOGICAL DATA; STILL WATER; FLUME FLOWS; GROWTH; MORTALITY; PREDATION; GASTROPOD; BAHAMAS AB A suction dredge survey was conducted in the Bahamas in a tidal flow field system which contained a nursery ground for the economically significant gastropod Strombus gigas (queen conch). Settlement of larval conch within the system was associated with the specific location of the nursery and positively correlated with subsequent recruitment to the juvenile population (<45 mm shell length). Settlement was relatively independent of habitat features including depth, sediment characteristics, and macrophytes. Conversely, densities of micro-predators (small crabs, shrimp, and predaceous gastropods) capable of consuming early postsettlement conch were often correlated with habitat features such as seagrass shoot density, seagrass detritus, and organic content of the sediment. The density of small xanthid crabs (mode=1.5 mm carapace width) was positively correlated with density of live postsettlement conch (mean less than or equal to 4/m(2)), suggesting that conch settle in predator-prone areas or that the crabs respond numerically to small conch (or both). Densities of xanthids were very high (to >200/m(2)), and the crabs probably represent an important source of mortality for small conch in the primary nursery ground. Shells of dead conch indicated that molluscan and asteroid predators probably caused most of the predatory mortality on young conch that settled outside the nursery. Because critical settlement and recruitment habitats for queen conch are associated with particular hydrographic conditions, these habitats cannot be identified or predicted simply by mapping obvious features such as seagrass cover, depth, or sediment type. An understanding of dynamic processes, such as larval transport and retention, selective settlement mechanisms, and trophic ecology, will be required to identify critical nursery habitats. C1 Caribbean Marine Res Ctr, Vero Beach, FL 32963 USA. RP Stoner, AW (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, NOAA, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 52 TC 11 Z9 11 U1 1 U2 15 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 885 EP 899 PG 15 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400016 ER PT J AU Moles, A Heifetz, J Love, DC AF Moles, A Heifetz, J Love, DC TI Metazoan parasites as potential markers for selected Gulf of Alaska rockfishes SO FISHERY BULLETIN LA English DT Article C1 Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, NOAA, Juneau, AK 99801 USA. RP Moles, A (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, NOAA, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 7 TC 14 Z9 16 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 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1998 VL 96 IS 4 BP 912 EP 916 PG 5 WC Fisheries SC Fisheries GA 131UJ UT WOS:000076593400019 ER PT J AU Chavez, FP Strutton, PG McPhaden, MJ AF Chavez, FP Strutton, PG McPhaden, MJ TI Biological-physical coupling in the central equatorial Pacific during the onset of the 1997-98 El Nino SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EASTERN TROPICAL PACIFIC; SOUTHERN OSCILLATION; OCEAN; GROWTH; IRON AB Perturbations to phytoplankton biomass associated with the onset of the 1997-98 El Nino event are described and explained using physical and bio-optical data from moorings in the central equatorial Pacific. The physical progression of El Nino onset is depicted, from reversal of the trade winds in the western equatorial Pacific, through eastward propagation of equatorially trapped Kelvin waves and advection of waters from the nutrient-poor western equatorial warm pool. Fluctuations in chlorophyll and quantum yield of fluorescence are tightly coupled to thermocline variations. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Chavez, FP (reprint author), Monterey Bay Aquarium Res Inst, POB 628, Moss Landing, CA 95039 USA. EM chfr@mbari.org; stpe@mbari.org; mcphaden@pmcl.noaa.gov RI Strutton, Peter/C-4466-2011; McPhaden, Michael/D-9799-2016 OI Strutton, Peter/0000-0002-2395-9471; NR 23 TC 63 Z9 65 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1998 VL 25 IS 19 BP 3543 EP 3546 DI 10.1029/98GL02729 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 125KJ UT WOS:000076236500001 ER PT J AU Maes, C AF Maes, C TI Estimating the influence of salinity on sea level anomaly in the ocean SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Evidence is found over broad regions of the ocean that variations in salinity have sufficiently large effects on sea level such that they may be detectable by an altimeter. The mechanisms involve the salinity variability within the tropical mixed layer, the tropical and subtropical baroclinic response in the main halocline and the barotropic response in the Southern Ocean. All these processes lead to signals in sea level which range between 2 and 10 cm. An important result is that in the western tropical Pacific Ocean the effect of salinity variability on sea level may be equal to the effect of thermal variability. C1 Natl Ocean & Atmospher Adm, Natl Ctr Environm Predict, Washington, DC USA. RP Maes, C (reprint author), NCEP, EMC, CMB, Room 807,World Weather Bldg,5200 Auth Rd, Camp Springs, MD 20746 USA. EM cmaes@sun1.wwb.noaa.gov RI maes, christophe/L-4049-2015 OI maes, christophe/0000-0001-6532-7141 NR 13 TC 49 Z9 51 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1998 VL 25 IS 19 BP 3551 EP 3554 DI 10.1029/98GL02758 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 125KJ UT WOS:000076236500003 ER PT J AU Burkholder, JB Orlando, JJ AF Burkholder, JB Orlando, JJ TI Rate coefficient upper limits for the BrONO2 and ClONO2+O-3 reactions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TEMPERATURE AB The gas phase reactions BrONO2 and ClONO2 + O-3 --> Products (k(1) and k(3)) were examined at 235 +/- 2 K and 700 Torr N-2 using a Fourier transform infrared spectrometer coupled to a temperature regulated long path absorption cell. The loss of BrONO2 and ClONO2 were measured to be independent of the O-3 concentration yielding k(1) <1 x 10(-20) cm(3) molecule(-1) s(-1) and k(3) < 4 x 10(-21) cm(3) molecule(-1) s(-1). C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Burkholder, JB (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Burkholder, James/H-4914-2013 NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1998 VL 25 IS 19 BP 3567 EP 3569 DI 10.1029/98GL02626 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 125KJ UT WOS:000076236500007 ER PT J AU Fang, P Bevis, M Bock, Y Gutman, S Wolfe, D AF Fang, P Bevis, M Bock, Y Gutman, S Wolfe, D TI GPS meteorology: Reducing systematic errors in geodetic estimates for zenith delay SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PRECIPITABLE WATER; INTERFEROMETRY; POSITION; VAPOR AB Differences between long term precipitable water (PW) time series derived from radiosondes, microwave water vapor radiometers, and GPS stations reveal offsets that are often as much as 1-2 mm PW. All three techniques are thought to suffer from systematic errors of order 1 mm PW. Standard GPS processing algorithms are known to be sensitive to the choice of elevation cutoff angle at this level. We present a processing protocol that is shown to reduce elevation angle dependence in geodetic estimates of zenith delay and, hence, reduce the systematic errors in derived precipitable water. This protocol includes use of the Niell zenith delay mapping functions and International GPS Service phase center models. C1 Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NOAA, Boulder, CO 80303 USA. RP Fang, P (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, 9500 Gilman Dr, La Jolla, CA 92093 USA. NR 18 TC 54 Z9 57 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1998 VL 25 IS 19 BP 3583 EP 3586 DI 10.1029/98GL02755 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 125KJ UT WOS:000076236500011 ER PT J AU Halthore, RN Nemesure, S Schwartz, SE Imre, DG Berk, A Dutton, EG Bergin, MH AF Halthore, RN Nemesure, S Schwartz, SE Imre, DG Berk, A Dutton, EG Bergin, MH TI Models overestimate diffuse clear-sky surface irradiance: A case for excess atmospheric absorption SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATION; BAND AB Radiative transfer models consistently overestimate surface diffuse downward irradiance in cloud-free atmospheres by 9 to 40% at two low altitude sites while correctly calculating direct-normal Solar irradiance. For known systematic and random measurement errors and for realistic aerosol optical properties, the discrepancy can be resolved by a reduction in the vertical aerosol optical thickness (AOT) inferred from sunphotometric measurements by an average 0.02 +/- 0.01 for 32 cases examined, together with a compensating increase in a continuum-like atmospheric absorptance over the solar spectrum of similar to 5.0% +/- 3.0%. This phenomenon is absent at two high altitude sites, where models and measurements agree to within their mutual uncertainties. Examination of apparent AOT at several locations around the globe also indicates presence of such excess atmospheric absorption. The proposed absorption and corresponding reduction in AOT would have important consequences for climate prediction and remote sensing. C1 Brookhaven Natl Lab, Dept Appl Sci, ECD, Upton, NY 11973 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Spectral Sci Inc, Burlington, MA 01803 USA. RP Halthore, RN (reprint author), Brookhaven Natl Lab, Dept Appl Sci, ECD, Bldg 815E, Upton, NY 11973 USA. EM halthore@bnl.gov RI Schwartz, Stephen/C-2729-2008 OI Schwartz, Stephen/0000-0001-6288-310X NR 18 TC 67 Z9 69 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1998 VL 25 IS 19 BP 3591 EP 3594 DI 10.1029/98GL52809 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 125KJ UT WOS:000076236500013 ER PT J AU Wood, HM AF Wood, HM TI Access to NOAA space-based data SO GEOTIMES LA English DT Letter C1 NOAA, Off Satellite Data Proc & Distribut, Natl Environm Satellite Data & Informat Off, US Dept Commerce, Washington, DC 20233 USA. RP Wood, HM (reprint author), NOAA, Off Satellite Data Proc & Distribut, Natl Environm Satellite Data & Informat Off, US Dept Commerce, Washington, DC 20233 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 USA SN 0016-8556 J9 GEOTIMES JI Geotimes PD OCT PY 1998 VL 43 IS 10 BP 4 EP 4 PG 1 WC Geosciences, Multidisciplinary SC Geology GA 126DF UT WOS:000076277100002 ER PT J AU Long, ER MacDonald, DD AF Long, ER MacDonald, DD TI Recommended uses of empirically derived, sediment quality guidelines for marine and estuarine ecosystems SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article ID FLORIDA; TOXICITY AB Sediment quality guidelines (SQGs), based upon empirical analyses of matching chemical and biological data, have been developed for many potentially toxic substances. The predictive abilities and recommended applications of two sets of guidelines, ERLs/ERMs and TELs/PELs, are discussed in this paper. The SQGs were intended as informal (i.e., non-regulatory) benchmarks to aid in the interpretation of chemical data. Low-range values (i.e., ERLs or TELs) were intended as concentrations below which adverse effects upon sediment-dwelling fauna would be expected only infrequently. In contrast, the ERMs and PELs represent chemical concentrations above which adverse effects are Likely to occur. Evaluations of the reliability and predictive ability of the SQGs indicate they can be used effectively to assess the quality of soft, aqueous, sedimentary deposits. Specifically, the SQGs can be used to classify sediment samples with regard to their potential for toxicity, to identify contaminants of concern, and to prioritize areas of concern based on the frequency and degree to which guidelines are exceeded. Toxicity and bioaccumulation tests, toxicity identification evaluations, and benthic community assessments provide complimentary information for assessing sediment quality. C1 US NOAA, Off Ocean Resources Conservat & Assessment, Seattle, WA 98115 USA. MacDonald Environm Sci Ltd, Namaimo, BC, Canada. RP Long, ER (reprint author), US NOAA, Off Ocean Resources Conservat & Assessment, 7600 Sand Pt Way NE, Seattle, WA 98115 USA. NR 25 TC 265 Z9 288 U1 3 U2 50 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD OCT PY 1998 VL 4 IS 5 BP 1019 EP 1039 DI 10.1080/10807039891284956 PG 21 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 136MR UT WOS:000076863600001 ER PT J AU Clifford, PA Atkinson, SF Hinckley, DA Suedel, BC Ludwig, DF Dillon, TM AF Clifford, PA Atkinson, SF Hinckley, DA Suedel, BC Ludwig, DF Dillon, TM TI Selection of contaminants and receptors of concern for ecological risk assessments using the paired comparison technique (PCT) SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE consensus building approach; stakeholder concerns; ranking and weighting; receptors and contaminants of concern AB A critical component of the ecological risk assessment process, identification of contaminants and receptors of concern, is currently lacking an objective, data-driven, broadly applicable methodology. The paired comparison technique (PCT) can be used to meet this need by providing a standardized technique for making these decisions. PCT condenses the decision-making process down to individual components and ultimately generates an objective ranking for each alternative based on pertinent attributes. Factors considered in the PCT may be selected and weighted via a formal consensus building process which can incorporate stakeholder concerns. Once factors have been selected and weighted, each alternative is ranked relative to each other alternative for each factor. Each alternative ranking for each factor is multiplied by the factor's weight and the weighted rankings are summed. These sums are then used to rank alternatives relative to one another. This ranking provides decision-makers with a semiquantitative basis for making final decisions, although the technique itself does not (and should not) actually make the decision. Several examples of the technique using actual Superfund site data are presented. C1 Aquat Ecol Serv, Dillsboro, NC 28779 USA. Univ N Texas, Inst Appl Sci, Denton, TX 76203 USA. EA Engn Sci & Technol, Sparks, MD 21152 USA. Entrix Inc, Houston, TX 77005 USA. Exponent Inc, Landover, MD 20785 USA. US Dept Commerce, NOAA, Hazardous Mat Response & Assessment Div, Atlanta, GA 30303 USA. RP Clifford, PA (reprint author), Aquat Ecol Serv, POB 1233, Dillsboro, NC 28779 USA. NR 12 TC 0 Z9 1 U1 3 U2 3 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD OCT PY 1998 VL 4 IS 5 BP 1189 EP 1215 DI 10.1080/10807039891285054 PG 27 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 136MR UT WOS:000076863600011 ER PT J AU Chang, S Zdanowicz, VS Murchelano, RA AF Chang, S Zdanowicz, VS Murchelano, RA TI Associations between liver lesions in winter flounder (Pleuronectes americanus) and sediment chemical contaminants from north-east United States estuaries SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE contaminants; liver lesions; winter flounder ID SOLE PAROPHRYS-VETULUS; TROUT SALMO-GAIRDNERI; HEPATIC-LESIONS; ENGLISH SOLE; MARINE FISH; PUGET-SOUND; CARCINOGENIC AGENTS; AQUATIC ANIMALS; BOSTON HARBOR; NEW-YORK AB Neoplastic diseases, particularly of bottom-dwelling fishes, are more prevalent in coastal areas than in areas that are relatively pristine. Although sediments in many urbanized estuaries contain high concentrations of contaminants, there is little evidence linking a specific organic or inorganic chemical to a particular liver lesion in winter flounder (Pleuronectes americanus), despite increasing study in recent years. Between 1984 and 1986, sediments and winter flounder were collected from 10 sites in the north-east United States ranging from grossly polluted to relatively unimpacted. Sediments were analysed for polycyclic aromatic hydrocarbons (PAHs), chlorinated pesticides, polychlorinated biphenyls (PCBs), and metals. Gross and microscopic pathological examinations were conducted on winter flounder liver sections. Factor and canonical correlation analyses were used to explore associations between biological and chemical measurements. Hepatitis, cholangitis, phlebitis, and macrophage aggregate hyperplasia showed positive associations with low molecular weight, petroleum-derived PAHs (naphthalene, anthracene, l-methylnaphthalene, 2-methylnaphthalene. 2,6-dimethylnaphthalene, acenaphthene, phenanthrene, biphenyl, fluorene, and 1-methylphenanthrene), the pesticides lindane, hexachlorobenzene, heptachlor epoxide, and o,p'-DDD, tri- to hexachlorobiphenyls, and chromium, cadmium, lead, thallium, and selenium, but were negatively associated with the pesticides o,p'-DDT, p,p'-DDT, p,p'-DDE, and mirex. Cytoplasmic hepatocellular vacuolation, cytoplasmic bile duct vacuolation, neoplasms, and pre-neoplasms showed positive associations with most PAHs measured, whether petroleum-derived or combustion-derived (benzo[a]pyrene, benzo[e]pyrene, benzo[a]anthracene, dibenzo[a,h]anthracene, perylene, chrysene, and ftuoranthene), the pesticides dieldrin, trans-nonachlor and alpha-chlordane, and silver, copper, antimony, and tin, but no associations with PCBs were found. Coagulative necrosis, single cell necrosis and haemorrhagic necrosis showed positive associations with hepta- to nonachlorobiphenyls and arsenic, zinc, nickel, and mercury, and negative associations with high molecular weight, combustion-derived PAHs and DDT compounds and metabolites. C1 NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. NOAA, Natl Marine Fisheries Serv, Woods Hole Lab, Woods Hole, MA 02543 USA. RP Chang, S (reprint author), NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. NR 69 TC 25 Z9 25 U1 2 U2 11 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD OCT PY 1998 VL 55 IS 5 BP 954 EP 969 DI 10.1006/jmsc.1998.0354 PG 16 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 140JQ UT WOS:000077084500012 ER PT J AU Souders, TM Andrews, J Caravone, A Deyst, JP Duff, C Naboicheck, S AF Souders, TM Andrews, J Caravone, A Deyst, JP Duff, C Naboicheck, S TI A pulse measurement intercomparison SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE laboratory intercomparison; measurement; oscilloscopes; pulse measurements; time-domain measurements AB A pulse measurement intercomparison, organized by the National Institute of Standards and Technology (NIST) and conducted by the authors in their respective labs, is described, The purpose was to assess the state of the art for time-domain pulse waveform measurements in the nanosecond regime, and to find problem areas in need of better metrology support, The experiment was conducted by circulating two stable pulse generators among the five labs; participants recorded the waveforms over two different time epochs: 10.24 ns with 10 ps sampling period and 102.4 ns with 100 ps sampling period, The data records were sent to NIST for analysis and comparison. The pulse generators that were used produce a step-like waveform with nominal high and low states of 0.5 and 0 V, respectively, transition duration of approximately 200 ps, and significant frequency components out to almost 10 GHz. The settling behavior was purposely spoiled. Some significant measurement differences were found among the five labs. The overall experiment is described, along with measurement results and conclusions. C1 Picosecond Pulse Labs Inc, Boulder, CO 80301 USA. Tektronix Inc, Beaverton, OR 97077 USA. NIST, Gaithersburg, MD 20899 USA. Hewlett Packard Co, Colorado Springs, CO 80901 USA. LeCroy Inc, Chestnut Ridge, NY 10977 USA. RP Souders, TM (reprint author), Picosecond Pulse Labs Inc, Boulder, CO 80301 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 1998 VL 47 IS 5 BP 1031 EP 1036 DI 10.1109/19.746549 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 168AA UT WOS:000078666900001 ER PT J AU Deyst, JP Paulter, NG Daboczi, T Stenbakken, GN Souders, TM AF Deyst, JP Paulter, NG Daboczi, T Stenbakken, GN Souders, TM TI A fast-pulse oscilloscope calibration system SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE calibration; deconvolution; oscilloscopes; sampled data systems; standards; timebase; transient response; transition duration ID TIME JITTER; DECONVOLUTION AB A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of similar to 20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National Institute of Standards and Technology (NIST), It comprises fast electrical step generation hardware, a personal computer (PC) and software, and a reference waveform, i.e., a data file containing an estimate of the step generator output signal. The reference waveform is produced by prior measurement by NIST of the step generator output signal (calibration step signal). When the FPOCS is in use, the calibration step signal is applied to the device under test, which is an oscilloscope sampling channel. The measured step waveform is corrected for timebase errors, then the reference waveform is deconvolved from it. The results are impulse, step, and frequency response estimates, and their associated parameters (e.g., transition duration, transition amplitude, -3 dB bandwidth) and uncertainties. The system and its components are described, and preliminary test results are presented. C1 NIST, Div Elect, Gaithersburg, MD 20899 USA. Tech Univ Budapest, Dept Measurement & Informat Syst, H-1521 Budapest, Hungary. RP Deyst, JP (reprint author), NIST, Div Elect, Gaithersburg, MD 20899 USA. RI Daboczi, Tamas/G-8207-2012; OI Daboczi, Tamas/0000-0002-7371-2186 NR 23 TC 11 Z9 12 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 1998 VL 47 IS 5 BP 1037 EP 1041 DI 10.1109/19.746552 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 168AA UT WOS:000078666900002 ER PT J AU Souders, TM AF Souders, TM TI Code probability distributions of A/D converters with random input noise SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE analog-digital conversion; codes; noise; probability; successive approximation AB The specific architecture of an A/D converter influences the code probability distributions that result from random input noise. In particular, the output codes of successive approximation A/D converters have a spiked distribution, and its variance is half that of the corresponding input noise. In addition, the distribution has a small bias. These and other related results are derived, and are qualitatively supported by measurement data on a real 16-bit A/D converter. C1 Technol Adm, Natl Inst Stand & Technol, Elect & Elect Engn Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Souders, TM (reprint author), Technol Adm, Natl Inst Stand & Technol, Elect & Elect Engn Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 1998 VL 47 IS 5 BP 1042 EP 1045 DI 10.1109/19.746553 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 168AA UT WOS:000078666900003 ER PT J AU Stenbakken, GN Deyst, JP AF Stenbakken, GN Deyst, JP TI Time-base nonlinearity determination using iterated sine-fit analysis SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE calibration; curve fitting; distortion; sampled data systems; timing; timing jitter ID DATA-ACQUISITION CHANNELS; FITTING PROCEDURE AB A new method is presented to determine the timebase errors of sampling instruments, The method does not require a time-base error model and thus provides accurate estimates where model-based methods fail. Measurements of sinewaves at multiple phases and frequencies are used as test signals, A harmonic distortion model is used to account for amplitude nonlinearity of the sampling channel. Use of an independent method for estimating the channel noise and jitter allows an accurate estimate of the harmonic order, Methods are presented for separating the harmonics generated by the sampling channel from those generated by the time-base distortion, The use of an iterative sine-fit procedure gives accurate results in a short time, A new weighting procedure is described, which minimizes the error in the estimates, Guidelines are given for selecting good sets of test frequencies, Results are shown for both simulated and real data. C1 NIST, Div Elect, Gaithersburg, MD 20899 USA. RP Stenbakken, GN (reprint author), NIST, Div Elect, Gaithersburg, MD 20899 USA. NR 9 TC 26 Z9 29 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 1998 VL 47 IS 5 BP 1056 EP 1061 DI 10.1109/19.746556 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 168AA UT WOS:000078666900006 ER PT J AU Mansoor, A Martzloff, FD Phipps, KO AF Mansoor, A Martzloff, FD Phipps, KO TI Gapped arresters revisited: A solution to cascade coordination SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article AB This paper provides a brief perspective on how the coordination of cascaded surge-protective devices (SPDs) has become an issue. We propose an approach where the 'ancient' technology of gapped arresters may well be the answer to the dilemma of the incompatibility of a service-entrance SPD having relatively high limiting voltage with the proliferation of built-in or plug-in SPDs having relatively low limiting voltage inside the buildings. The solution involves providing a gapped arrester at the service entrance and gapless SPDs inside the building. An example is given of such a combination, with experimental verification of the proposed solution and computer modeling that allows a parametric evaluation of the significant factors in any candidate combination of SPDs. C1 Applicat Ctr, Knoxville, TN USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Mansoor, A (reprint author), Applicat Ctr, Knoxville, TN USA. NR 24 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 USA SN 0885-8977 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD OCT PY 1998 VL 13 IS 4 BP 1174 EP 1181 DI 10.1109/61.714481 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 122XG UT WOS:000076096300029 ER PT J AU Feng, SC Zhang, C AF Feng, SC Zhang, C TI A modular architecture for rapid development of CAPP systems for agile manufacturing SO IIE TRANSACTIONS LA English DT Article ID OF-THE-ART AB Current manufacturing planning software systems, such as computer aided process planning (CAPP) systems, are general and in a closed form. It is very difficult to modify these systems to respond to a user's dynamically changing needs. These systems are no longer suitable for agile manufacturing. This paper presents research aimed at developing a novel architecture for the rapid development of CAPP systems. The architecture supports the construction of CAPP systems from prepackaged, plug-compatible software components. Specifications of the architecture and its building blocks are defined. Several important issues in architecture implementation are discussed, and an experimental system is illustrated. Finally, an Internet-based distributed CAPP system architecture is presented as a preview of next generation CAPP system development. C1 FAMU FSU, Coll Engn, Dept Ind Engn, Tallahassee, FL 32310 USA. Natl Inst Stand & Technol, Mfg Syst Integrat Div, Mfg Engn Lab, Gaithersburg, MD 20899 USA. RP Zhang, C (reprint author), FAMU FSU, Coll Engn, Dept Ind Engn, 2525 Pottsdamer St, Tallahassee, FL 32310 USA. NR 22 TC 16 Z9 16 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0740-817X J9 IIE TRANS JI IIE Trans. PD OCT PY 1998 VL 30 IS 10 BP 893 EP 903 DI 10.1080/07408179808966543 PG 11 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 166YE UT WOS:000078604900003 ER PT J AU Liao, K Schultheisz, CR Hunston, DL Brinson, LC AF Liao, K Schultheisz, CR Hunston, DL Brinson, LC TI Long-term durability of fiber-reinforced polymer-matrix composite materials for infrastructure applications: A review SO JOURNAL OF ADVANCED MATERIALS LA English DT Review ID ENVIRONMENTAL-STRESS CORROSION; FRP JACKETED CONCRETE; E-GLASS FILAMENTS; FATIGUE BEHAVIOR; CREEP-BEHAVIOR; VISCOELASTIC CHARACTERIZATION; UNIDIRECTIONAL COMPOSITES; STRUCTURAL APPLICATIONS; MOISTURE ABSORPTION; EPOXY COMPOSITES C1 Nanyang Technol Univ, Sch Appl Sci, Div Mat Engn, Singapore 2263, Singapore. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. RP Liao, K (reprint author), Nanyang Technol Univ, Sch Appl Sci, Div Mat Engn, Singapore 2263, Singapore. RI Brinson, L. Catherine/B-6678-2009; Brinson, L Catherine/B-1315-2013; Liao, Kin/A-7915-2014 OI Brinson, L Catherine/0000-0003-2551-1563; Liao, Kin/0000-0001-6352-2349 NR 388 TC 59 Z9 60 U1 5 U2 38 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER-COVINA JI J. Adv. Mater. PD OCT PY 1998 VL 30 IS 4 BP 3 EP 40 PG 38 WC Materials Science, Multidisciplinary SC Materials Science GA 209HX UT WOS:000081043100002 ER PT J AU Ryzhkov, AV Zrnic, DS AF Ryzhkov, AV Zrnic, DS TI Discrimination between rain and snow with a polarimetric radar SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; DUAL-POLARIZATION RADAR; MELTING LAYER; ICE PARTICLES; PRECIPITATION; REGION; STORMS; PHASE; HAIL AB Polarimetric signatures of snow precipitation for six Oklahoma snowstorms are examined. The available data consist of specific differential phase K-DP. differential reflectivity Z(DR), cross-correlation coefficient rho(hv), and radar reflectivity factor Z. These data were obtained with the 10-cm-wavelength Cimarron polarimetric weather radar. The data suggest that in pure snow the average values of K-DP and Z(DR) do not follow a systematic trend with change of the radar reflectivity factor if Z < 35 dBZ; this is not the case in rain. Precipitation is qualified as snow if the average Z(DR) is less than 0.2 dB for Z < 35 dBZ. The presence of a bright band with a pronounced rho(hv) minimum and Z(DR) maximum is a good discernible feature for discriminating between snow and rain. Thus, a localized deep minimum of the cross-correlation coefficient delineates the transition region between snow and rain in the horizontal direction if sufficiently large snowflakes are generated in the transition area. Otherwise, a sharp change of Z(DR) can be used to localize the position of the snow-rain line. C1 NOAA, CIMMS, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Ryzhkov, AV (reprint author), NOAA, CIMMS, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 18 TC 67 Z9 70 U1 0 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 1998 VL 37 IS 10 BP 1228 EP 1240 DI 10.1175/1520-0450(1998)037<1228:DBRASW>2.0.CO;2 PN 2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 128CM UT WOS:000076387700002 ER PT J AU Mellor, GL Oey, LY Ezer, T AF Mellor, GL Oey, LY Ezer, T TI Sigma coordinate pressure gradient errors and the Seamount problem SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MEDITERRANEAN OUTFLOW; OCEAN MODELS; CIRCULATION AB In a recent paper by Mellor et al., it was found that in two-dimensional (x, z) applications with finite horizontal viscosity and zero diffusivity, the velocity error, associated with the evaluation of horizontal density or pressure gradients on a sigma coordinate grid, prognostically disappeared, leaving behind a small and physically insignificant distortion in the density field. The initial error is numerically consistent in that it decreases as the square of the grid increment size. In this paper, we label this error as a sigma error of the first kind. In three-dimensional applications, the authors have encountered an error that did not disappear and that has not been understood by us or, apparently, others. This is a vorticity error that is labeled a sigma error of the second kind and is a subject of this paper Although it does not prognostically disappear, it seems to be tolerably small. To evaluate these numerical errors, the authors have adopted the seamount problem initiated by Beckman and Haidvogel. It represents a stringent test case, as evidenced by their paper, wherein the model is initialized with horizontal isopycnals, zero velocity, and no forcing; then, any velocities that develop must be considered errors. Two appendices are important adjuncts to the paper the first providing theoretical confirmation and understanding of the numerical results, and the second delving into additional errors related to horizontal or isosigma diffusion. It is, however, shown that satisfactory numerical solutions are obtained with zero diffusivity. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Mellor, GL (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. OI Ezer, Tal/0000-0002-2018-6071 NR 17 TC 124 Z9 129 U1 1 U2 2 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 OCT PY 1998 VL 15 IS 5 BP 1122 EP 1131 DI 10.1175/1520-0426(1998)015<1122:SCPGEA>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 120NH UT WOS:000075962100005 ER PT J AU Feingold, G Yang, S Hardesty, RM Cotton, WR AF Feingold, G Yang, S Hardesty, RM Cotton, WR TI Feasibility of retrieving cloud condensation nucleus properties from Doppler cloud radar, microwave radiometer, and lidar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID STRATUS; ASTEX AB This paper explores the possibilities of using K-a-band Doppler radar, microwave radiometer, and lidar as a means of retrieving cloud condensation nucleus (CCN) properties in the stratocumulus-capped marine boundary layer. The retrieval is based on the intimate relationship between the cloud drop number concentration, the vertical air motion at cloud base, and the CCN activation spectrum parameters. The CCN properties that are sought are the C and k parameters in the N = CSk relationship, although activation spectra based on the lognormal distribution of particles is also straightforward. Cloud droplet concentration at cloud base is retrieved from a Doppler cloud radar combined with a microwave radiometer following a previously published technique. Cloud base is determined from a Lidar or ceilometer. Vertical velocity just above cloud base is determined from the vertically pointing Doppler cloud radar. By combining the simultaneous retrievals of drop number and vertical velocity, and assuming theoretical relationships between these parameters and the subcloud aerosol parameters, the C parameter can be derived, under the assumption of a fixed k. If a calibrated backscatter lidar measurement is available, retrieval of both C and k parameters is possible. The retrieval is demonstrated for a dataset acquired during the Atlantic Stratocumulus Transition Experiment using a least squares minimization technique. Sensitivity to assumptions used in the retrieval is investigated. It is suggested that this technique may afford the acquisition of long-term datasets for climate monitoring purposes. Further investigation with focused experiments designed to address the issue more rigorously is required. C1 NOAA, Cooperat Inst Res Atmosphere, Environm Technol Lab, Boulder, CO 80303 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Feingold, G (reprint author), NOAA, Cooperat Inst Res Atmosphere, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. RI Feingold, Graham/B-6152-2009; Hardesty, Robert/H-9844-2013 NR 26 TC 8 Z9 8 U1 0 U2 4 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 OCT PY 1998 VL 15 IS 5 BP 1188 EP 1195 DI 10.1175/1520-0426(1998)015<1188:FORCCN>2.0.CO;2 PG 8 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 120NH UT WOS:000075962100011 ER PT J AU Mathew, M AF Mathew, M TI Crystal structure of strontium potassium arsenate octahydrate SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE crystal structure; hydrated ions; ionic hydration; strontium arsenate; struvites; struvite-type structure ID X-RAY-DIFFRACTION; PHOSPHATE; IONS AB The crystal structure of strontium potassium arsenate octahydrate, SrKAsO4. 8H(2)O, has been determined by single crystal X-ray diffraction. The crystals are tetragonal, a = 7.144(1), c = 23.613(2) Angstrom, space group I4(1)md (No. 109), Z = 4, V = 1205.1(1) Angstrom(3), and d(c) = 2.258 g cm(-3). All cations and anions in this compound are completely surrounded by water molecules. Sr2+ and K+ ions are each coordinated to eight water molecules arranged in an approximately square antiprism. The [Sr(H2O)(8)](2+) polyhedron shares one face of four water molecules with a [K(H2O)(8)](+) polyhedron forming O-4-Sr-O-4-K-O-4 polyhedra. The O-4-ST-O-4-K-O-4 units are linked together through a pair of edge-sharing linkages of the outer water molecules, alternating along the a-axis and b-axis. The hydrated cation polyhedra appear to define the host lattice, which accommodates the AsO43- ion in the interstitial space. The environment of the AsO43- ion consists of 16 water molecules; each oxygen atom is the acceptor in hydrogen bonds from four water molecules. The pair distances associated with this environment may be used in investigations of the structure of hydrated XO4n- ions in solutions. Each water molecule is coordinated to one Sr and one K, and hydrogen bonded to two O atoms of two different AsO43- ions. There is no hydrogen bonding between water molecules. C1 Natl Inst Stand & Technol, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. RP Mathew, M (reprint author), Natl Inst Stand & Technol, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. RI G, Neela/H-3016-2014 NR 19 TC 2 Z9 2 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD OCT PY 1998 VL 28 IS 10 BP 741 EP 746 DI 10.1023/A:1021812527701 PG 6 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA 175EM UT WOS:000079080100004 ER PT J AU Chen, P Newman, M AF Chen, P Newman, M TI Rossby wave propagation and the rapid development of upper-level anomalous anticyclones during the 1988 US drought SO JOURNAL OF CLIMATE LA English DT Article ID UNITED-STATES; STATIONARY WAVES; FLOW; PREDICTION; IMPACT AB The upper-tropospheric circulation is investigated for the three months of April, May, and June 1988 during which the Great Plains region of the United States experienced one of its most severe droughts in history. It is found that during this period the April-June (AMJ) seasonal-mean anomaly was not representative of the variability of 10-day low-pass anomalies. Rather, over North America large fluctuations on monthly and shorter timescales occurred, with the dominant streamfunction anomalies not strongly anticyclonic until June. In fact, the AMJ anomaly was dominated by two episodes of rapidly developing, intense anomalous anticyclones in early and late June. Examination of the daily 10-day low-pass streamfunction anomalies at 300 mb suggests that propagating Rossby waves originating in the west Pacific played a dominant role in the initiation of these intense anomalous anticyclones. Numerical experiments with a linear, time-dependent, barotropic model also support this hypothesis. These results suggest that the AMJ anomaly, which has been characterized as a wave train seemingly forced in the east Pacific, may not provide a useful picture of the circulation associated with the drought. Instead, the drought may be better studied not as a single seasonal event, but rather as a succession of events that together produced a serious hydrological deficit.y C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Boulder, CO 80309 USA. RP Newman, M (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Campus Box 449, Boulder, CO 80309 USA. EM men@cdc.noaa.gov RI Newman, Matthew /F-8336-2010 OI Newman, Matthew /0000-0001-5348-2312 NR 27 TC 37 Z9 38 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD OCT PY 1998 VL 11 IS 10 BP 2491 EP 2504 DI 10.1175/1520-0442(1998)011<2491:RWPATR>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130TM UT WOS:000076536500003 ER PT J AU Higgins, RW Mo, KC Yao, Y AF Higgins, RW Mo, KC Yao, Y TI Interannual variability of the US summer precipitation regime with emphasis on the southwestern monsoon SO JOURNAL OF CLIMATE LA English DT Article ID CENTRAL UNITED-STATES; LOW-LEVEL JET; NORTH-AMERICAN MONSOON; NASA/DAO REANALYSES; MOISTURE TRANSPORT; DIURNAL-VARIATIONS; MEXICAN MONSOON; CLIMATOLOGY; NCEP/NCAR; GULF AB Relationships between the interannual variability of the U.S. summer precipitation regime and the intensification, weakening, or changes in position of the climatological-mean circulation features that organize this regime are examined. The focus is on the atmospheric conditions over the conterminous United States relative to wet and dry monsoons over the southwestern United States. The onset of the monsoon in this region, which typically begins in early July, is determined using an index based on daily observed precipitation for a 32-yr (1963-94) period. Composites of observed precipitation and various fields from the National Centers for Environmental Prediction-National Center for Atmospheric Research Reanalysis for wet and dry monsoons are used to show that the interannual variability of the summer precipitation regime closely mimics the seasonal changes associated with the development of the North American monsoon system. The warm season precipitation regime is characterized by a continental-scale precipitation pattern consisting of an out-of-phase relationship between the Southwest and the Great plains/Northern Tier and an in-phase relationship between the Southwest and the East Coast. This pattern is preserved for both wet and dry monsoons, but the Southwest is relatively wetter and the Great Plains are relatively drier during wet monsoons. Wet (dry) monsoons are also associated with a stronger (weaker) upper-tropospheric monsoon anticyclone over the western United States, consistent with changes in the upper-tropospheric divergence, midtropospheric Vertical motion, and precipitation patterns. The intensity of the monsoon anticyclone over the western United States appears to be one of the most fundamental controls on summertime precipitation downstream over the Great Plains. Evidence is presented that the interannual variability of the U.S. warm season precipitation regime is linked to the season-to-reason "memory" of the coupled atmosphere-ocean system over the eastern tropical Pacific. In particular it is shown that SST anomalies in the eastern Pacific cold tongue and precipitation anomalies in the intertropical convergence zone, present during the winter and spring preceding the monsoon, are linked via an anomalous local Hadley circulation to the warm season precipitation regime over the United States and Mexico. Wet (dry) summer monsoons tend to follow winters characterized by dry (wet) conditions in the Southwest and wet (dry) conditions in the Pacific Northwest. This association is attributed, in part, to the memory imparted to the atmosphere by the accompanying Pacific SST anomalies. C1 Natl Weather Serv, Anal Branch, Climate Predict Ctr, NOAA,NCEP, Washington, DC 20233 USA. Res & Data Syst Corp, Greenbelt, MD USA. RP Higgins, RW (reprint author), Natl Weather Serv, Anal Branch, Climate Predict Ctr, NOAA,NCEP, W-NP52,4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. EM wd52wh@sgi85.wwb.noaa.gov NR 40 TC 134 Z9 136 U1 1 U2 18 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1998 VL 11 IS 10 BP 2582 EP 2606 DI 10.1175/1520-0442(1998)011<2582:IVOTUS>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130TM UT WOS:000076536500008 ER PT J AU Gallagher, DT Pan, QW Gilliland, GL AF Gallagher, DT Pan, QW Gilliland, GL TI Mechanism of ionic strength dependence of crystal growth rates in a subtilisin variant SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE crystal structure; ion screening; lattice packing; protein crystal growth; subtilisin ID MACROMOLECULAR STRUCTURES; MORPHOLOGY AB An orthorhombic crystal form of a subtilisin variant exhibits a systematic variation in growth rates of its three unique faces, resulting in pronounced morphology variations, depending on ionic strength. Several common salts cause a concentration-dependent change in the crystal habit from thin plates to isometric bars. Analysis of the four crystal contacts in the 1.8 Angstrom resolution X-ray structure leads to models of the morphological growth fronts and reveals a short (2.5 Angstrom) hydrogen bond between two carboxyl groups in one of the contacts. Cation screening of this interaction in the nascent contact is proposed to play a key role in making the growth rates ionic strength sensitive. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Gallagher, DT (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 24 TC 11 Z9 11 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD OCT PY 1998 VL 193 IS 4 BP 665 EP 673 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 134CJ UT WOS:000076725000030 ER PT J AU Olla, BL Davis, MW Schreck, CB AF Olla, BL Davis, MW Schreck, CB TI Temperature magnified postcapture mortality in adult sablefish after simulated trawling SO JOURNAL OF FISH BIOLOGY LA English DT Article DE by-catch; physiology; survival; stress ID ANOPLOPOMA-FIMBRIA; EL-NINO; ACCLIMATION; CALIFORNIA; FECUNDITY; WATERS; OREGON AB For sablefish Anoplopoma fimbria that had been transferred abruptly from ambient (5.7 degrees C) to temperatures ranging from 15 to 20 degrees C for 30 min followed by 15 min in air (19.5 degrees C), mortality increased with temperature. Mortality occurred at lower temperatures for sablefish that were net-towed for 4 h at ambient temperature before exposure to a rapid increase in temperature. A clear relationship was apparent between serum lactate and temperature with lactate increasing as temperature increased. For treatments in which mortality did not occur, lactate decreased sharply within 24 h, suggesting recovery. It would appear that the critical postcapture temperature for sablefish that reside and are captured at 4-6 degrees C, would be between 12 and 15 degrees C. The results of this study suggest that fishery management strategies designed to increase postcapture survival of sablefish bycatch should include a consideration of the impact of exposure to seasonal thermoclines and seasonally elevated air temperatures. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. Oregon State Univ, US Geol Survey, Oregon Cooperat Fishery Res Unit, Biol Resources Div,Dept Fisheries & Wildlife, Corvallis, OR 97331 USA. RP Olla, BL (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NR 21 TC 36 Z9 37 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD OCT PY 1998 VL 53 IS 4 BP 743 EP 751 DI 10.1111/j.1095-8649.1998.tb01829.x PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 125QA UT WOS:000076247500005 ER PT J AU Beckman, BR Dickhoff, WW AF Beckman, BR Dickhoff, WW TI Plasticity of smolting in spring chinook salmon: relation to growth and insulin-like growth factor-I SO JOURNAL OF FISH BIOLOGY LA English DT Article DE gill Na+ K+ ATPase; IGF-I; development; life history ID JUVENILE ATLANTIC SALMON; ONCORHYNCHUS-KISUTCH WALBAUM; LIFE-HISTORY VARIATION; K+ ATPASE ACTIVITY; SALAR L; RAINBOW-TROUT; COHO SALMON; SEAWATER ADAPTATION; SALINITY TOLERANCE; GILL NA+ AB In two year classes of Willamette River spring chinook salmon, reared at the Willamette Hatchery, and two groups of Yakima River spring chinook salmon, one sampled from the Yakima River and the other reared in a hatchery, fish which had relatively high growth rates in the summer-autumn period smelted in the autumn as measured by increases in gill Na+ K+ ATPase activity. In contrast, groups with relatively low growth rate did not smelt in the autumn. Plasma levels of insulin-like growth factor-I (IGF-I) showed discrete differences between groups, with high levels associated with increased gill Na+ K+ ATPase activities. These results demonstrate that smelting is plastic in spring chinook salmon, occurring in the autumn or the spring. In addition, smelting appeared to be related to growth rate; however, the relationships shown were correlational and causal mechanisms were not elucidated. Yet, the results do indicate a relationship between growth, an endocrine growth meter and smelting, suggesting a mechanistic link between developmental plasticity and the environment mediated by the endocrine system. (C) 1998 The Fisheries Society of the British Isles. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Beckman, BR (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM beckman@fish.washigton.edu NR 80 TC 54 Z9 56 U1 1 U2 17 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-1112 EI 1095-8649 J9 J FISH BIOL JI J. Fish Biol. PD OCT PY 1998 VL 53 IS 4 BP 808 EP 826 DI 10.1111/j.1095-8649.1998.tb01834.x PG 19 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 125QA UT WOS:000076247500010 ER PT J AU Arnoldy, RL Posch, JL Ebgebretson, MJ Fukunishi, H Singer, HJ AF Arnoldy, RL Posch, JL Ebgebretson, MJ Fukunishi, H Singer, HJ TI Pi1 magnetic pulsations in space and at high latitudes on the ground SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MULTIPLE CORRELATION; FIELD; ANTARCTICA; AURORA AB Nightside, high-latitude (68 degrees-80 degrees magnetic) Pi1 waves, measured with a ground array of induction magnetometers, are studied and compared with magnetic field measurements made at synchronous orbit near the meridian of the ground measurements. The objectives of the study are to relate the ground signatures of Pi1B and PiC to the auroral substorm and its manifestation at synchronous orbit in an attempt to understand the origin of the Pi1 waves. Pi1 waves are measured in the equatorial plane by the GOES spacecraft and appear to be initiated by the dipolarization process of the nightside tail magnetic field at the onset of substorms. Across two meridional arrays of ground stations the earliest onset of Pi1B generally occurred at the lowest-latitude station and, in many instances, this burst was superimposed on a ground signature of a sudden onset of the westward electrojet. In one instance, where good coverage of ground optical data was available, this sudden onset Pi1B was time related to the overhead passage of a westward traveling auroral surge. The timing of maximum Pi1B across the array in both longitude and latitude agrees with the westward motion of the local aurora! surge and the poleward motion of the aurora after the surge has arrived at a giver, site, suggesting a local ionospheric source for some of the Pi1 waves. However, across the entire array, extending about 12 degrees in latitude and 20 degrees in longitude, there often was nearly simultaneous Pi1B wave power at all sites which occurred before the maximum signal at a given site (and presumably local aurora), suggesting horizontal ducting of wave power from the onset of Pi1B seen earlier at the auroral zone latitude. Prompt turn-on of PiC waves across the array also indicates ducting of these waves. The narrow bandwidth of the PiC waves themselves suggests a resonant cavity source for them which would indicate that some wave power enters the ionosphere from space (consistent with the GOES in situ data) as the trigger wave for this resonant source mechanism. In conclusion, this study finds evidence for local ionospheric currents, magnetospheric waves, and resonant cavity modes as sources for Pi1 ground waves. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Augsburg Coll, Dept Phys, Minneapolis, MN 55454 USA. Tohoku Univ, Upper Atmosphere & Space Res Lab, Sendai, Miyagi 980, Japan. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Arnoldy, RL (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. EM roger.arnoldy@unh.edu NR 30 TC 29 Z9 29 U1 1 U2 1 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 OCT 1 PY 1998 VL 103 IS A10 BP 23581 EP 23591 DI 10.1029/98JA01917 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125XL UT WOS:000076262300019 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 Propagation of a spheromak - 2. Three-dimensional structure of a spheromak SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC CLOUDS; INTERPLANETARY AB Magnetic clouds are commonly modeled as flux ropes and, less frequently, as spheromaks or toroids. In a previous paper,we performed a numerical study of the propagation of a spheromak in the inner heliosphere using a three-dimensional, self-consistent, MHD description. In this second paper on propagating spheromaks we study the interaction of their initial internal field (depending on the orientation of their axes) with the ambient interplanetary magnetic field and their three-dimensional structure near 1 AU. It is shown by our simulation that a spheromak with a poloidal field expands into a toroid during its propagation. It develops into an oblate shape by virtue of its momentum interaction with the solar wind. Draping of magnetic field lines around it causes its polar axis (evolving into the toroid's hole) to be aligned with the radial direction irrespective of its initial orientation. This means that a hypothetical spacecraft can cross the resulting toroid only once, thereby observing signatures similar to a flux rope crossing. Double crossings are excluded even near the Sun (0.3 AU). Therefore the observations of magnetic clouds which resemble a double flux rope crossing must be explained in a way other than within the spheromak or toroidal model. C1 Acad Sci Czech Republ, Inst Astron, Prague 14131 4, Czech Republic. NOAA, Space Environm Ctr, RESE, Boulder, CO 80303 USA. RP Vandas, M (reprint author), Acad Sci Czech Republ, Inst Astron, Bocni 2 1401, Prague 14131 4, Czech Republic. RI Vandas, Marek/G-9054-2014; xue, yansheng/A-9712-2012 NR 19 TC 14 Z9 15 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 1998 VL 103 IS A10 BP 23717 EP 23725 DI 10.1029/98JA01902 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125XL UT WOS:000076262300029 ER PT J AU Breaker, LC Gilhousen, DB Tolman, HL Burroughs, LD AF Breaker, LC Gilhousen, DB Tolman, HL Burroughs, LD TI Initial results from long-term measurements of atmospheric humidity and related parameters in the marine boundary layer at two locations in the Gulf of Mexico SO JOURNAL OF MARINE SYSTEMS LA English DT Article DE Rotronic MP-100 humidity sensors; humidity; marine boundary layer; Gulf of Mexico; latent heat flux; surface waves ID SURFACE; SEA AB Measurements of boundary layer moisture have been acquired from Rotronic MP-100 sensors deployed on two NDBC buoys in the northern Gulf of Mexico from June through November 1993. For one sensor, which was retrieved approximately 8 months after deployment, the post- and precalibrations agreed closely and fell well within WMO specifications for accuracy. The second sensor operated continuously from June 1993 to February 1997 (similar to 3.5 years). Buoy observations of relative humidity and supporting data were used to calculate specific humidity and the surface fluxes of latent and sensible heat. Specific humidities from the buoys were compared with observations of moisture obtained from nearby ship reports, and the correlations were generally high (0.7-0.9). Surface gravity wave spectra were also acquired. The time series of specific humidity and the other buoy parameters revealed three primary scales of variability, small (similar to h), synoptic (similar to days), and seasonal (similar to months). The synoptic variability was clearly dominant and occurred primarily during September, October, and November. Most of the synoptic variability was due to frontal systems that dropped down into the Gulf of Mexico from the continental US followed by air masses which were cold and dry. Cross-correlation analyses of the buoy data indicated that: (1) the moisture field was highly coherent over distances of 800 km or more in the northern Gulf of Mexico; and (2) both specific humidity and air temperature served as tracers of the motion associated with propagating atmospheric disturbances. These correlation analyses also revealed that the prevailing weather systems generally entered the buoy domain from the South prior to September, but primarily from the North thereafter. Spectra of the various buoy parameters indicated strong diurnal and semidiurnal variability for barometric pressure and sea surface temperature (SST) and lesser variability for air temperature, wind speed and significant wave height. The surface fluxes of latent and sensible heat were dominated by the synoptic events which took place from September through November with the transfer of latent heat being primarily from the ocean to the atmosphere. Finally, an analysis of the surface wave observations from each buoy, which included calculations of wave age and estimates of surface roughness, indicate that major heat and moisture flux events coincide with periods of active wave growth, although the data were insufficient to identify any causal relationships. C1 NOAA, Natl Weather Serv, NCEP, Washington, DC 20233 USA. NOAA, Natl Weather Serv, Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. RP Breaker, LC (reprint author), NOAA, Natl Weather Serv, NCEP, Washington, DC 20233 USA. NR 24 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD OCT PY 1998 VL 16 IS 3-4 BP 199 EP 217 DI 10.1016/S0924-7963(97)00041-9 PG 19 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 131ZB UT WOS:000076604200002 ER PT J AU Josell, D van Heerden, D Read, D Bonevich, J Shechtman, D AF Josell, D van Heerden, D Read, D Bonevich, J Shechtman, D TI Tensile testing low density multilayers: Aluminum/titanium SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PROPERTY RELATIONSHIPS; MECHANICAL-PROPERTIES; FCC TITANIUM; NI-CU; COMPOSITES; STRENGTH; FOILS AB Yield stresses, ultimate tensile strengths, and specific strengths of aluminum/titanium multilayer thin films are determined from the results of uniaxial tensile tests. The plasticity in the stress-strain curves, the nature of the fracture surfaces, and the relationship of the yield stress and the bilayer thickness are discussed. Properties are compared with those of other multilayer materials published in the literature. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Boulder, CO 80302 USA. Technion Israel Inst Technol, Haifa, Israel. RP Josell, D (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 32 Z9 33 U1 0 U2 12 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 1998 VL 13 IS 10 BP 2902 EP 2909 DI 10.1557/JMR.1998.0397 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 127QM UT WOS:000076362100027 ER PT J AU Vaudin, MD Rupich, MW Jowett, M Riley, GN Bingert, JF AF Vaudin, MD Rupich, MW Jowett, M Riley, GN Bingert, JF TI A method for crystallographic texture investigations using standard x-ray equipment SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB A fast and accurate method has been developed for measuring crystalline texture in homogeneous materials. The method uses a conventional powder x-ray diffractometer capable of theta scans. Two scans are recorded from the sample: first, a high resolution theta-2 theta scan is obtained of a Bragg peak whose diffracting planes are normal to the preferred orientation direction; second, a theta scan is obtained using this peak. The theta scan contains the required texture information, but the intensities must be corrected for defocusing and absorption to obtain the texture profile. The theta-2 theta scan of the Bragg peak is used to make the defocusing correction, and first principles calculations are used to correct for absorption. The theory behind these corrections is presented here. The validity of the technique has been verified by making measurements on untextured alumina. Data obtained from Bi2Sr2Ca2Cu3O10 superconducting tape specimens with this technique are compared with texture data obtained with a four-circle diffractometer. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. Amer Superconductor Corp, Westborough, MA 01581 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Vaudin, MD (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 9 TC 33 Z9 33 U1 0 U2 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 1998 VL 13 IS 10 BP 2910 EP 2919 DI 10.1557/JMR.1998.0398 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 127QM UT WOS:000076362100028 ER PT J AU Sams, RL Blake, TA Sharpe, SW Flaud, JM Lafferty, WJ AF Sams, RL Blake, TA Sharpe, SW Flaud, JM Lafferty, WJ TI High-resolution infrared study of the nu(14), nu(17), and nu(18) bands of (B2H6)-B-11 and (BBH6)-B-10-B-11 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID DIBORANE AB Using high-resolution Fourier transform spectra, a thorough analysis of the nu(14) c-type, nu(17) a-type, and nu(18) a-type bands of both (B2H6)-B-11 and (BBH6)-B-10-B-11 has been carried in the 10.3-, 6.2-, and 8.5-mu m spectral regions, respectively. From this analysis a large set of precise ground state combination differences with J values up to 36 (31) and K-a values extending to 18 (18) was derived for (B2H6)-B-11((BBH6)-B-10-B-11), These data were fitted using a Watson-type Hamiltonian leading to accurate ground state rotational constants. An r(s) value for the B-B distance has been determined to be 1.7645(10) Angstrom. The determination of upper state Hamiltonian constants proved to be much more difficult since the corresponding rotational levels of each of the bands are strongly perturbed by nearby dark states. To account for these strong localized resonances, it was necessary to introduce the relevant interacting terms in the Hamiltonian matrix. As a result it was possible to calculate the upper state energy levels quite satisfactorily. From these fits, estimates of the band centers and a few of the rotational constants of the resonating dark states were obtained. (C) 1998 Academic Press. C1 Pacific NW Lab, Richland, WA 99352 USA. Univ Paris 11, CNRS, Photophys Mol Lab, F-91405 Orsay, France. CSIC, Inst Estructura Mat, E-28006 Madrid, Spain. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Sams, RL (reprint author), Pacific NW Lab, POB 999,Battelle Blvd, Richland, WA 99352 USA. NR 17 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1998 VL 191 IS 2 BP 331 EP 342 DI 10.1006/jmsp.1998.7649 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 128CN UT WOS:000076387800014 ER PT J AU Flaud, JM Birk, M Wagner, G Orphal, J Klee, S Lafferty, WJ AF Flaud, JM Birk, M Wagner, G Orphal, J Klee, S Lafferty, WJ TI The far infrared spectrum of HOCl: Line positions and intensities SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID HYPOCHLOROUS ACID; SPECTROSCOPY; REGION; BAND AB The far infrared spectrum of HOCl has been recorded at high resolution between 20 and 360 cm(-1) by means of Fourier transform spectroscopy, and it was possible to observe pure rotation lines involving rotational levels with high K-a quantum numbers (up to K-a = 9). These lines combined with microwave and tunable far infrared data available in the literature were least squares fitted using a Watson-type Hamiltonian. The fitting leads to precise sets of rotational and centrifugal distortion constants for the ground states of both isotopomers (HOCl)-Cl-35 and (HOCl)-Cl-37. Also relative line intensities were measured and their fitting allowed the determination of rotational corrections to the b-component of the permanent transition moment. Finally, to get Hamiltonian constants consistent with the newly determined ground state constants for the (100), (010), (001) vibrational states, available data concerning the nu(1), nu(2), and nu(3) bands were refitted. Three interesting points are to be stressed. For the (001) state, we were able to complete the existing data with rotation lines observed in our spectra up to rather high K-a values (K-a = 7). For (HOCl)-Cl-35, we were able to show that some (010) and (100) levels are perturbed by levels of the (002) and (030) states, respectively, through Coriolis-type interactions. This allows the determination of the band centers of these two dark states. (C) 1998 Academic Press. C1 Univ Paris Sud, CNRS, Photophys Mol Lab, F-91405 Orsay, France. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. DLR, Inst Optoelekt, D-82234 Oberpfaffenhofen, Germany. Univ Giessen, Inst Phys Chem, D-35392 Giessen, Germany. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Flaud, JM (reprint author), Univ Paris Sud, CNRS, Photophys Mol Lab, Batiment 210, F-91405 Orsay, France. RI Orphal, Johannes/A-8667-2012 OI Orphal, Johannes/0000-0002-1943-4496 NR 18 TC 25 Z9 25 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1998 VL 191 IS 2 BP 362 EP 367 DI 10.1006/jmsp.1998.7653 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 128CN UT WOS:000076387800017 ER PT J AU Varberg, TD Roberts, JC Tuominen, KA Evenson, KM AF Varberg, TD Roberts, JC Tuominen, KA Evenson, KM TI The far-infrared spectrum of deuterium iodide SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article C1 Macalester Coll, Dept Chem, St Paul, MN 55105 USA. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Macalester Coll, Dept Chem, 1600 Grand Ave, St Paul, MN 55105 USA. NR 5 TC 6 Z9 6 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 EI 1096-083X J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1998 VL 191 IS 2 BP 384 EP 386 DI 10.1006/jmsp.1998.7648 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 128CN UT WOS:000076387800021 ER PT J AU Graczyk, TK Farley, CA Fayer, R Lewis, EJ Trout, JM AF Graczyk, TK Farley, CA Fayer, R Lewis, EJ Trout, JM TI Detection of Cryptosporidium oocysts and Giardia cysts in the tissues of eastern oysters (Crassostrea virginica) carrying principal oyster infectious diseases SO JOURNAL OF PARASITOLOGY LA English DT Article ID HEMOCYTES; PARVUM AB The potential cross-reactivity of the combined Cryptosporidium/Giardia direct immunofluorescence antibodies (IFA) of MERIFLUOR(TM) and HYDROFLUOR(TM)-COMBO tests was examined against tissues containing known developmental stages of 12 pathogens causing the principal infectious diseases in oysters. Spores of Haplosporidium nelsoni and Haplosporidium costale produced positive acid-fast stain (AFS) reactions similar in intensity to Cryptosporidium parvum oocysts. Hexamita nelsoni trophozoites produced positive IFA reactions in both IFA tests; however, the intensity of fluorescence was considerably lower and the fluorescein-staining pattern different than those of Giardia cysts. The applicability of AFS for screening oysters for Cryptosporidium oocysts is low, and positive identification of Cryptosporidium oocysts cannot be accomplished based on the AFS. Presumptive IFA identification of the Cryptosporidium oocysts or Giardia cysts in the oyster tissue should fulfill 3 criteria, i.e., bright-green fluorescence of the same intensity as C, parvum oocysts and Giardia cysts in the positive control, correct size and shape of the fluorescein-stained objects, and oocyst or cyst shell clearly visible. C1 Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, Baltimore, MD 21205 USA. US Dept Commerce, Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, Cooperat Oxford Lab, Oxford, MD 21654 USA. USDA ARS, Beltsville Agr Res Ctr, Inst Livestock & Poultry Sci, Immun & Dis Resistance Lab, Beltsville, MD 20705 USA. RP Graczyk, TK (reprint author), Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, 615 N Wolfe St, Baltimore, MD 21205 USA. NR 19 TC 36 Z9 37 U1 1 U2 4 PU AMER SOC PARASITOLOGISTS PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0022-3395 J9 J PARASITOL JI J. Parasitol. PD OCT PY 1998 VL 84 IS 5 BP 1039 EP 1042 DI 10.2307/3284641 PG 4 WC Parasitology SC Parasitology GA 130JX UT WOS:000076517900029 PM 9794651 ER PT J AU Wong, EM Bonevich, JE Searson, PC AF Wong, EM Bonevich, JE Searson, PC TI Growth kinetics of nanocrystalline ZnO particles from colloidal suspensions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SMALL SEMICONDUCTOR CRYSTALLITES; ZINC-OXIDE; QUANTUM CONFINEMENT; OPTICAL-PROPERTIES; ELECTRONIC STATES; CDSE NANOCRYSTALS; SIZE DEPENDENCE; CLUSTERS; DOTS; LUMINESCENCE AB Colloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz-Slyozov-Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion-limited transport of species dissolved in solution. C1 Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. RP Searson, PC (reprint author), Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. RI Searson, Peter /A-3311-2010; OI Searson, Peter/0000-0002-5417-0828 NR 57 TC 279 Z9 284 U1 8 U2 89 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 1 PY 1998 VL 102 IS 40 BP 7770 EP 7775 DI 10.1021/jp982397n PG 6 WC Chemistry, Physical SC Chemistry GA 127ZM UT WOS:000076380800013 ER PT J AU Lagalante, AF Wood, C Clarke, AM Bruno, TJ AF Lagalante, AF Wood, C Clarke, AM Bruno, TJ TI Kamlet-Taft solvatochromic parameters for 25 glycol ether solvents and glycol ether aqueous solutions SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE glycol ethers; Kamlet-Taft; solvatochromic ID SOLVATION ENERGY RELATIONSHIPS; WATER PARTITION-COEFFICIENTS; PI-STAR; OCTANOL; PREDICTION; SOLUBILITY; SCALE AB The Kamlet-Taft parameters for 25 glycol ethers and their aqueous solutions were measured. Values for the three Kamlet-Taft parameters: the hydrogen-bond donor ability, hydrogen-bond acceptor ability, and the dipolarity/polarizability, as well as the index of refraction, were determined for each pure glycol ether and each aqueous glycol solution. A correlation matrix between other known solvent parameters and the measured Kamlet-Taft values revealed only one correlation, suggesting that the three measured Kamlet-Taft parameters for the glycol ethers are independent solvent descriptors. Last, trends in the measured Kamlet-Taft values were related to functional group modifications to the basic glycol ether structure. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div 838 01, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div 838 01, 325 Broadway, Boulder, CO 80303 USA. NR 16 TC 15 Z9 15 U1 1 U2 8 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD OCT PY 1998 VL 27 IS 10 BP 887 EP 900 DI 10.1023/A:1022607127781 PG 14 WC Chemistry, Physical SC Chemistry GA 142DZ UT WOS:000077185800003 ER PT J AU Hoshikuma, J Kawashima, K Nagaya, K Taylor, AW AF Hoshikuma, J Kawashima, K Nagaya, K Taylor, AW TI Stress-strain model for confined reinforced concrete in bridge piers - Closure SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Editorial Material C1 Minist Constr, Publ Works Res Inst, Earthquake Engn Div, Tsukuba, Ibaraki 305, Japan. Tokyo Inst Technol, Dept Civil Engn, Tokyo 152, Japan. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Struct Div, Gaithersburg, MD 20899 USA. RP Hoshikuma, J (reprint author), Minist Constr, Publ Works Res Inst, Earthquake Engn Div, Tsukuba, Ibaraki 305, Japan. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD OCT PY 1998 VL 124 IS 10 BP 1228 EP 1230 DI 10.1061/(ASCE)0733-9445(1998)124:10(1228) PG 3 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA V2652 UT WOS:000165537300017 ER PT J AU Chuang, TJ AF Chuang, TJ TI Some remarks on "Improved analysis for flexural creep with application to SiAloN ceramics" SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB An earlier paper co-authored by the present author contains a major assumption in the analytical method that may not be valid in a general class of structural ceramics. A more-rigorous mathematical analysis without this assumption has been performed, and the closed-form solutions of the description of the asymmetric power-law creep behavior are presented. The results presented here should be regarded as further improvements to the original paper, because they are applicable to a more-general case without such an assumption. Using the two loading cases as a numerical example, the present solutions indicate that, in the case of SiAlON ceramics, the original predictions on the stress exponents are still valid, However, the predictions on the pre-exponent constants differ from one to three orders of magnitude, because of error propagation. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Chuang, TJ (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1998 VL 81 IS 10 BP 2749 EP 2750 PG 2 WC Materials Science, Ceramics SC Materials Science GA 129EM UT WOS:000076450800038 ER PT J AU Johnson, BC Kumar, AR Zhang, ZM Livigni, DJ Cromer, CL Scott, TR AF Johnson, BC Kumar, AR Zhang, ZM Livigni, DJ Cromer, CL Scott, TR TI Heat transfer analysis and modeling of a cryogenic laser radiometer SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT 32nd National Heat Transfer Conference CY AUG 10-12, 1997 CL BALTIMORE, MARYLAND SP Amer Inst Chem Engineers AB This study investigates the laser optimized cryogenic radiometer (LOCR) recently acquired by the National Institute of Standards and Technology in Boulder, Colorado, to calibrate laser power meters and detectors. The objectives are to evaluate potentially significant sources of uncertainty in the radiometric measurements and to develop transient models that efficiently and accurately predict the behavior of this radiometer. The analysis suggests that radiation from the Brewster window assembly may cause the total power entering the radiometer to drift more than 130 nW for a room temperature variation of 0.2 K, Steady-state modeling of the LOCR with finite element analysis software indicates a relative inequivalence between optical and electrical heating of 4 x 10(-6) at the 1-mW power level. A new thermal model has been developed to simplify transient predictions by combining lumped parameter and one-dimensional elements. This model outperforms single-time-constant exponential models and can be expanded to simulate the complete radiometer system. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. Natl Inst Stand & Technol, Div Optoelect, Sources & Detectors Grp, Boulder, CO 80303 USA. RP Johnson, BC (reprint author), Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NR 22 TC 7 Z9 7 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD OCT-DEC PY 1998 VL 12 IS 4 BP 575 EP 581 DI 10.2514/2.6378 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 132CM UT WOS:000076612500018 ER PT J AU Kia, OE Doermann, DS AF Kia, OE Doermann, DS TI Document image coding for processing and retrieval SO JOURNAL OF VLSI SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY LA English DT Article AB Document images belong to a unique class of images where the information is embedded in the language represented by a series of symbols on the page rather than in the visual objects themselves. Since these symbols tend to appear repeatedly, a domain-specific image coding strategy can be designed to facilitate enhanced compression and retrieval. In this paper we describe a coding methodology that not only exploits component-level redundancy to reduce code length but also supports efficient data access. The approach identifies and organizes symbol patterns which appear repeatedly. Similar components are represented by a single prototype stored in a library and the location of each component instance is coded along with the residual between it and its prototype. A representation is built which provides a natural information index allowing access to individual components. Compression results are competitive and compressed-domain access is superior to competing methods. Applications to network-related problems have been considered, and show promising results. C1 Natl Inst Stand & Technol, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Automat Res, Language & Media Proc Lab, College Pk, MD 20742 USA. RP Kia, OE (reprint author), Natl Inst Stand & Technol, Math & Computat Sci Div, Bldg 820,Room 365, Gaithersburg, MD 20899 USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-5773 J9 J VLSI SIG PROC SYST JI J. VLSI Signal Process. Syst. Signal Image Video Technol. PD OCT PY 1998 VL 20 IS 1-2 BP 121 EP 135 DI 10.1023/A:1008074424861 PG 15 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 144DL UT WOS:000077298400009 ER PT J AU Vetter, RD Fry, B AF Vetter, RD Fry, B TI Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms SO MARINE BIOLOGY LA English DT Article ID VENT TUBE WORM; CLAM SOLEMYA-REIDI; RIFTIA-PACHYPTILA JONES; EAST PACIFIC RISE; SULFIDE OXIDATION; ELEMENTAL SULFUR; BACTERIAL SYMBIONT; GUTLESS CLAM; ROSE GARDEN; BRINE SEEP AB Total sulfur (S-TOT), elemental sulfur (S degrees) and sulfur-isotope compositions (delta(34)S) Of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S degrees was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S degrees contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. delta(34)S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10%)S-34 fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and delta(34)S values less than +5%, can be used to infer a thiotrophic mode of nutrition. C1 Univ Calif San Diego, Scripps Inst Oceanog, Div Marine Biol Res, La Jolla, CA 92093 USA. Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA. RP Vetter, RD (reprint author), NOAA, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NR 54 TC 26 Z9 27 U1 1 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD OCT PY 1998 VL 132 IS 3 BP 453 EP 460 DI 10.1007/s002270050411 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 137NH UT WOS:000076920800011 ER PT J AU Murphy, PP Feely, RA Wanninkhof, R AF Murphy, PP Feely, RA Wanninkhof, R TI On obtaining high-precision measurements of oceanic pCO(2) using infrared analyzers SO MARINE CHEMISTRY LA English DT Article DE carbon uptake; air-sea equilibrium; infrared analysis; calibration ID PARTIAL-PRESSURE; CARBON-DIOXIDE; SURFACE WATERS; NORTH-ATLANTIC; CO2; PACIFIC; EXCHANGE; SINK AB Assessments of ocean carbon uptake using the air-sea disequilibrium of CO2 require very high quality measurements of pCO(2) in the atmosphere and in surface seawater. These measurements are often collected and analyzed using infrared detectors. Laboratory data are presented here which suggest that errors of the order of several parts per million in xCO(2) can result if the analyzer temperature and pressure are not carefully matched during calibration and sampling. Field data were examined to address questions about the importance of measuring analysis temperature and pressure under more extreme conditions, sample averaging, and calibration frequency. The results indicate that calibration frequency can be minimized without significant compromises in data quality if the analyzer temperatures and pressures are suitably monitored and/or controlled. Daily calibrations gave results to within 0.4 ppm of the results obtained by hourly calibration when the temperature of the analyzer was controlled to +/-0.2 degrees C and the voltages were corrected for pressure differences between calibration and sampling. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Pacific Marine Environm Lab, Ocean Climate Res Div, Seattle, WA 98115 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Murphy, PP (reprint author), NOAA, Pacific Marine Environm Lab, Ocean Climate Res Div, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 18 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD OCT PY 1998 VL 62 IS 1-2 BP 103 EP 115 DI 10.1016/S0304-4203(98)00030-9 PG 13 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 105QN UT WOS:000075085300008 ER PT J AU Carretta, JV Forney, KA Laake, JL AF Carretta, JV Forney, KA Laake, JL TI Abundance of southern California coastal bottlenose dolphins estimated from tandem aerial surveys SO MARINE MAMMAL SCIENCE LA English DT Article DE coastal bottlenose dolphins; Tursiops truncatus; California; abundance; tandem aerial survey; double-count; mark-recapture; visibility bias ID VISIBILITY BIAS; HARBOR PORPOISE; LINE TRANSECT; PROBABILITY AB We describe a tandem aerial survey method for bottlenose dolphins (Tursiops truncatus) that uses two aircraft and independent observer teams to conduct consecutive surveys of the same coastal strip one hour apart. Alternatively, one aircraft with one observer team surveys the same coastal strip twice over several hours. Using mark-recapture analysis, we corrected survey counts for visibility bias resulting from missing dolphin groups at the surface and submerged groups. Dolphin groups were considered "recaptured" when we determined that both observer teams had detected the same group. This tandem method is highly useful for estimating abundance (and visibility bias) for species where population closure may be assumed between flights. We assumed population closure between flights and matched groups using geographic location, group size, and expected travel rates. We derive a new variance estimator of population site which incorporates group-size variability commonly encountered in cetacean surveys. From six tandem surveys conducted from 1991 to 1994, we estimated the abundance of southern California coastal bottlenose dolphins to be between 78 (95% CI 60-102) and 271 (240-306) animals, with an average of 140 (128-154). Variability in abundance estimates is likely due to seasonal and interannual movement of animals along the California and Baja California coast. Abundance estimates from tandem surveys averaged 53% higher than dolphin counts obtained from individual survey flights, demonstrating the importance of correcting for visibility bias. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Carretta, JV (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. EM jim.carretta@noaa.gov NR 34 TC 27 Z9 31 U1 1 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0824-0469 EI 1748-7692 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 1998 VL 14 IS 4 BP 655 EP 675 DI 10.1111/j.1748-7692.1998.tb00755.x PG 21 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 128FL UT WOS:000076395000001 ER PT J AU Kvitek, RG Iampietro, PJ Bowlby, CE AF Kvitek, RG Iampietro, PJ Bowlby, CE TI Sea otters and benthic prey communities: A direct test of the sea otter as keystone predator in Washington State SO MARINE MAMMAL SCIENCE LA English DT Article ID PATTERNS C1 Calif State Univ Monterey, Monterey, CA USA. Moss Landing Marine Labs, Moss Landing, CA 95039 USA. Olympic Coast Natl Marine Sanctuary, Port Angeles, WA USA. RP Kvitek, RG (reprint author), Calif State Univ Monterey, Monterey, CA USA. NR 11 TC 10 Z9 12 U1 5 U2 27 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 1998 VL 14 IS 4 BP 895 EP 902 DI 10.1111/j.1748-7692.1998.tb00776.x PG 8 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 128FL UT WOS:000076395000022 ER PT J AU Lehman, J Sauvageau, J Vayshenker, I Cromer, C Foley, K AF Lehman, J Sauvageau, J Vayshenker, I Cromer, C Foley, K TI Silicon wedge-trap detector for optical fibre power measurements SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE optical fibre power measurement; absolute spectral responsivity calibration; optical fibre array; field of view measurement; wedge-trap optical detector AB We have designed and built an optical fibre power detector based on a large-area silicon PIN photodiode and a concave mirror in a wedge-trap configuration. The detector was designed as a high-accuracy transfer standard for near IR (835-865 nm) optical fibre power measurements with multimode fibre-ribbon cables in a manufacturing-production environment. Additional requirements were that the detector be insensitive to the input beam geometry, and able to accommodate different optical fibre connector types, collimated laser light, and highly diverging light from optical fibres. Four identical copies of the detector were evaluated at the NIST Laser Sources and Detectors Group calibration facility and one was tested in the manufacturing environment. The spatial and angular responsivity was highly uniform and varied less than 1% for angles of incidence ranging from 0 degrees to +/-15 degrees:. Absolute spectral responsivity measurements, for collimated and diverging light input wavelengths ranging from 672-852 nm, showed quantum efficiencies as high as 99%. Linearity measurements from a few nanowatts to a few milliwatts indicated a nonlinearity of only 0.05%. C1 Natl Inst Stand & Technol, Sources & Detectors Grp, Boulder, CO USA. Motorola Inc, Adv Packaging Design & Automat Ctr, Chandler, AZ USA. RP Natl Inst Stand & Technol, Sources & Detectors Grp, 325 Broadway, Boulder, CO USA. RI Vayshenker, Igor/H-9793-2013 OI Vayshenker, Igor/0000-0002-7098-3781 NR 8 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD OCT PY 1998 VL 9 IS 10 BP 1694 EP 1698 DI 10.1088/0957-0233/9/10/008 PG 5 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 130PJ UT WOS:000076528300008 ER PT J AU Hollman, KW Fortunko, CM AF Hollman, KW Fortunko, CM TI An accurate method for measurement of transverse elastic-wave velocities SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE ultrasound; evanescent wave; elastic coefficient; transmission coefficient; phase ID ANISOTROPIC MATERIALS; SPECTROSCOPY; CONSTANTS; COMPOSITE AB We demonstrate a novel analysis that improves the accuracy of angle-dependent elastic-wave velocities in plates for water-immersion measurements. Water-immersion measurements utilize the conversion from longitudinal to transverse mode to determine the velocities of transverse waves. However, beyond the critical angle for longitudinal waves, the phase of the transmitted transverse waves is affected by the presence of evanescent longitudinal waves at the interface. With pulse superposition analysis this effect systematically decreases the apparent velocities at some angles. Previous researchers have corrected the apparent velocities by calculating the theoretical phase shift from known parameters, but this correction requires narrow-band pulses or tone bursts as well as estimations of these parameters. An advantage of our analysis is that it eliminates the need for a priori estimations of parameters. In addition, this analysis allows the use of broad-band pulses that are more applicable to thin plates. To demonstrate these advantages, measurements were conducted on an isotropic steel plate as it was rotated in an immersion tank and insonified with a broad-band ultrasonic transducer. We compared velocities determined by the pulse-echo superposition analysis with velocities determined by our analysis. As expected, there was no significant difference between the longitudinal velocities, but systematic variations in the transverse velocities were lower with this new method. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Univ Michigan, Biomed Ultrason Lab, Room 3304,GG Brown Bldg,2350 Hayward St, Ann Arbor, MI 48109 USA. NR 14 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD OCT PY 1998 VL 9 IS 10 BP 1721 EP 1727 DI 10.1088/0957-0233/9/10/012 PG 7 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 130PJ UT WOS:000076528300012 ER PT J AU Krupka, J Derzakowski, K Riddle, B Baker-Jarvis, J AF Krupka, J Derzakowski, K Riddle, B Baker-Jarvis, J TI A dielectric resonator for measurements of complex permittivity of low loss dielectric materials as a function of temperature SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE complex permittivity; dielectric resonator; Rayleigh-Ritz technique; alumina; polytetrafluoroethylene; cross-linked polystyrene; variable temperature AB An application of a TE01 delta mode dielectric resonator is described for precise measurements of complex permittivity and the thermal effects on permittivity for isotropic dielectric materials. The Rayleigh-Ritz technique was employed to find a rigorous relationship between permittivity, resonant frequency, and the dimensions of the resonant structure, with relative computational accuracy of less than 10(-3). The influence of conductor loss and its temperature dependence was taken into account in the dielectric loss tangent evaluation. Complex permittivities of several materials, including cross-linked polystyrene, polytetrafluoroethylene, and alumina, were measured in the temperature range of 300-400 K. Absolute uncertainties of relative permittivity measurements were estimated to be smaller than 0.2%, limited mainly by uncertainty in the sample dimensions. For properly chosen sample dimensions, materials with dielectric loss tangents in the range of 5 x 10(-7) to 5 x 10(-3) can be measured using the TE01 delta mode dielectric resonator. C1 Inst Mikroelekt & Optoelekt PW, PL-00662 Warsaw, Poland. Inst Radioelekt PW, PL-00665 Warsaw, Poland. Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. RP Inst Mikroelekt & Optoelekt PW, Koszykowa 75, PL-00662 Warsaw, Poland. NR 15 TC 240 Z9 240 U1 2 U2 25 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD OCT PY 1998 VL 9 IS 10 BP 1751 EP 1756 DI 10.1088/0957-0233/9/10/015 PG 6 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 130PJ UT WOS:000076528300015 ER PT J AU Neiman, PJ Ralph, FM Shapiro, MA Smull, BF Johnson, D AF Neiman, PJ Ralph, FM Shapiro, MA Smull, BF Johnson, D TI An observational study of fronts and frontal mergers over the continental United States SO MONTHLY WEATHER REVIEW LA English DT Review ID EXTRATROPICAL MARINE CYCLONE; MESOSCALE CONVECTIVE SYSTEMS; MID-LATITUDE CYCLONES; SPECTRAL MOMENT DATA; 25-26 JANUARY 1978; LOW-LEVEL JET; WIND PROFILER; WINTER CYCLONES; BOUNDARY-LAYER; SQUALL-LINE AB The Stormscale Operational and Research Meteorology-Fronts Experiment Systems Tests (STORM-FEST) field program was carried our over the central United States to investigate the structure and dynamics of fronts and their attendant precipitation systems adjacent to complex topography and to evaluate new observing networks and analysis techniques for mesoscale research and weather forecasting. This study presents the analysis of data taken between 8 and 10 March 1992, which was the most active period of STORM-FEST. This three-day observing period was characterized by the passage of an extratropical cyclone and related fronts. The synoptic-scale conditions related to the cyclone and frontal evolutions are described. Multiple frontal zones (i.e., Pacific and arctic cold fronts, quasi-stationary polar front, dryline, maritime warm front) and associated regions of precipitation are documented, and their origins and interactions are explored. These features, both well defined and subtle, were observed with unique clarity on the mesoscale by the temporally and spatially enhanced experimental observing networks that included an unprecedented combination of aircraft, rawinsondes, and radar wind profilers. The 8-10 March period was dominated by two synoptic-scale cyclonic waves of Pacific and arctic origin that phased over the STORM-FEST domain. As the Pacific wave moved northeastward over the central United Stares it became elongated, while beneath it the arctic air spread southward and eastward, yielding a set of three tropopause folds, including one associated with a subtropical jet. Each wave included a cold front (i.e., the Pacific and arctic) at its leading edge. Owing to the relatively large mean density of the cold arctic air mass, the arctic front was clearly seen at the surface as it undercut all other weather systems and its westward movement was blocked by the Rocky Mountains. The downward penetration of the Pacific cold front to the surface was interrupted east of the dryline by the shallow (<150 mb deep), potentially more dense Gulf of Mexico air mass. Sensible heating and adiabatic descent from the elevated Mexican Plateau likely contributed to this density contrast. In effect, the top of the gulf air mass acted as the proxy ground level for the Pacific front, creating a cold front aloft. Detailed observations of the relationship between a prefrontal squall line and the Pacific cold front are provided. A preexisting quasi-stationary polar front situated over the central United States was involved in two frontal mergers, first with an overrunning maritime warm front whose warm-sector air mass was modified by the Gulf of Mexico, and then with the undercutting arctic front. The structural characteristics of these frontal zones became joined into a single "hybrid" or merged zone following the merger process. Unlike occlusions, for which the fronts slope in generally opposite directions, a frontal merger is characterized by fronts that slope in roughly the same direction. These observations and analyses illustrate the complexity of wintertime frontal systems and interactions that occur regularly over the central United States. C1 NOAA, ERL, ETL, Boulder, CO 80303 USA. NOAA, Natl Severe Storms Lab, ERL, Seattle, WA USA. Univ Washington, Seattle, WA 98195 USA. NOAA, ERL, Natl Severe Storms Lab, Mesoscale Res & Applicat Div, Boulder, CO 80303 USA. RP NOAA, ERL, ETL, Mail Code R-E-ET7,325 Broadway, Boulder, CO 80303 USA. EM pneiman@etl.noaa.gov NR 102 TC 26 Z9 28 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1998 VL 126 IS 10 BP 2521 EP 2554 DI 10.1175/1520-0493(1998)126<2521:AOSOFA>2.0.CO;2 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126RF UT WOS:000076306400001 ER PT J AU Hong, SY Pan, HL AF Hong, SY Pan, HL TI Convective trigger function for a mass-flux cumulus parameterization scheme SO MONTHLY WEATHER REVIEW LA English DT Article ID REGIONAL SPECTRAL MODEL; RANGE FORECAST MODEL; SOIL HYDROLOGY; MESOSCALE; SYSTEMS; NMC; CONVERGENCE; PREDICTION; IMPLICIT; EXPLICIT AB A precipitation physics package for the National Centers for Environmental Prediction Regional Spectral Model designed to improve the skill of precipitation forecasts is proposed. The package incorporates a prognostic grid-resolvable precipitation scheme and a parameterized convection scheme with a convective trigger function that explicitly couples boundary layer and convective precipitation processes. Comprehensive sensitivity experiments were conducted with a grid spacing of approximately 25 km for a heavy rain case over the United States during 15-17 May 1995. In this paper, the trigger function setup in the convective parameterization scheme and its impact on the predicted precipitation are discussed. Special attention is given to the interaction of cloud properties in the parameterized convection with the evolution of grid-resolvable precipitation physics. The impact of convective forcing due to different convective triggers on the large-scale pattern downstream is also discussed. The implementation of the prognostic cloud scheme and performance are presented in a companion paper. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, GSC, SAIC, Camp Springs, MD 20746 USA. RP Hong, SY (reprint author), Natl Ctr Environm Predict, Environm Modeling Ctr, GSC, SAIC, Rm 207,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 30 TC 120 Z9 121 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1998 VL 126 IS 10 BP 2599 EP 2620 DI 10.1175/1520-0493(1998)126<2599:CTFFAM>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126RF UT WOS:000076306400004 ER PT J AU Hong, SY Juang, HMH Zhao, QY AF Hong, SY Juang, HMH Zhao, QY TI Implementation of prognostic cloud scheme for a regional spectral model SO MONTHLY WEATHER REVIEW LA English DT Article ID MICROSCALE STRUCTURE; FRONTAL RAINBANDS; SQUALL LINE; MESOSCALE; PREDICTION; EXPLICIT; NMC; PARAMETERIZATION; PRECIPITATION; ORGANIZATION AB The purpose of this study is to develop a precipitation physics package for the National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) designed to improve the skill of precipitation forecasts. The package incorporates a prognostic grid-resolvable precipitation Scheme and a subgrid-scale precipitation parameterization scheme with a convective trigger that explicitly couples boundary layer and convective precipitation processes. In this paper, the implementation of a prognostic cloud scheme for the NCEP RSM is described. A subgrid-scale precipitation parameterization scheme was described in a companion paper. Dynamical processes such as advection and diffusion processes for liquid species are included. Eleven experiments are conducted with a grid spacing of approximately 25 km for a heavy rain case over the United States during 15-17 May 1995. Special attention is given to the setup of the prognostic grid-resolvable precipitation scheme on a spectral grid as well as the importance of dynamical processes on a mesoscale grid together with radiation feedback. Different prognostic cloud schemes, classified according to the number of predicted liquid species, are also compared. C1 Nat Ctr Environm Predict, Environm Modeling Ctr, GSC, SAIC, Camp Springs, MD 20746 USA. RP Hong, SY (reprint author), Nat Ctr Environm Predict, Environm Modeling Ctr, GSC, SAIC, Room 207,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 22 TC 93 Z9 112 U1 3 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1998 VL 126 IS 10 BP 2621 EP 2639 DI 10.1175/1520-0493(1998)126<2621:IOPCSF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126RF UT WOS:000076306400005 ER PT J AU Steenburgh, WJ Schultz, DM Colle, BA AF Steenburgh, WJ Schultz, DM Colle, BA TI The structure and evolution of gap outflow over the Gulf of Tehuantepec, Mexico SO MONTHLY WEATHER REVIEW LA English DT Article ID MARCH 1993 SUPERSTORM; EASTERN TROPICAL PACIFIC; MESOSCALE MODEL; SYNOPTIC-SCALE; OF-TEHUANTEPEC; WINDS; OCEAN; FLOW; PAPAGAYO; STRAIT AB Mesoscale-model simulations are used to examine the structure and dynamics of a gap-outflow event over the Gulf of Tehuantepec, Mexico, that was associated with a surge of cold air along the eastern slopes of the Sierra Madre. The simulated gap-outflow winds emerged from Chivela Pass, reached a maximum speed of 25 m s(-1), and turned anticyclonically as they fanned out over the gulf. Northerly winds were also able to ascend the mountains east, and to a lesser extent west, of Chivela Pass, indicating that the movement of cold air across the Sierra Madre was not confined to the pass. A mesoscale pressure ridge was aligned along the axis of the gap-outflow jet, which was flanked to the west by an anticyclonic eddy, and to the east by a weaker cyclonic eddy. A model-derived trajectory along the axis of the outflow jet traced an inertial path, with anticyclonic curvature produced primarily by the Coriolis acceleration, The cross-flow pressure-gradient acceleration along this trajectory was negligible because it followed the axis of the mesoscale pressure ridge. Trajectories west (east) of the jet axis experienced stronger (weaker) anticyclonic curvature than expected from inertial balance because the cross-flow pressure-gradient acceleration produced by the mesoscale pressure ridge reinforced (opposed) the anticyclonic deflection by the Coriolis acceleration. As a result of these directional variations in the cross-flow pressure-gradient acceleration, a fanlike wind pattern was observed rather than a narrow jet. Because of the large changes in SST and surface roughness that are observed during these gap-outflow events, better representation of these effects might improve future mesoscale-model simulations. Such improvements could be accomplished through coupled atmosphere-ocean mesoscale modeling, which could also be used to advance understanding of the oceanography of the gulf. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. NOAA, Cooperat Inst Reg Predict, Salt Lake City, UT USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Steenburgh, WJ (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 E,Room 819, Salt Lake City, UT 84112 USA. EM jimsteen@atmos.met.utah.edu RI Schultz, David M./A-3091-2010 OI Schultz, David M./0000-0003-1558-6975 NR 59 TC 69 Z9 69 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1998 VL 126 IS 10 BP 2673 EP 2691 DI 10.1175/1520-0493(1998)126<2673:TSAEOG>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126RF UT WOS:000076306400008 ER PT J AU German, CR Baker, ET Mevel, C Tamaki, K AF German, CR Baker, ET Mevel, C Tamaki, K CA FUJI Sci Team TI Hydrothermal activity along the southwest Indian ridge SO NATURE LA English DT Article ID TRIPLE JUNCTION; PLUMES; OCEAN AB Twenty years after the discovery of sea-floor hot springs, vast stretches of the global mid-ocean-ridge system remain unexplored for hydrothermal venting, The southwest Indian ridge is a particularly intriguing, region, as it is both the slowest-spreading of the main ridges(1) and the sole modern migration pathway between the diverse vent fauna of the Atlantic and Pacific oceans(2). A recent model postulates that a linear relation exists between vent frequency and spreading rate(3) and predicts vent fields to be scarcest along the slowest-spreading ridge sections, thus impeding migration and enhancing faunal diversity(2). Here, however, we report evidence of hydrothermal plumes at six locations within two 200-km-long sections of the southwest Indian ridge indicating: a higher frequency of venting than expected. These results suggest that fluxes of heat and chemicals from slow-spreading ridges may be greater than previously thought and that faunal migration along the southwest Indian ridge may serve as an important corridor for gene-flow between Pacific and Atlantic hydrothermal fields. C1 Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Paris 06, CNRS, Lab Petrol, F-75252 Paris, France. Univ Tokyo, Ocean Res Inst, Nakano Ku, Tokyo 164, Japan. RP German, CR (reprint author), Southampton Oceanog Ctr, Empress Dock, Southampton SO14 3ZH, Hants, England. RI lgm, ipgp/F-8820-2010; IPGP, Geosciences Marines/F-8780-2010; ipgp, Laboratoire geoscien/F-8471-2010; sauter, daniel/K-6532-2014; OI sauter, daniel/0000-0003-3651-8090; ROMMEVAUX, Celine/0000-0001-8624-5508 NR 18 TC 79 Z9 98 U1 1 U2 17 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD OCT 1 PY 1998 VL 395 IS 6701 BP 490 EP 493 DI 10.1038/26730 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 124ZG UT WOS:000076212200052 ER PT J AU Andersen, LH Jensen, MJ Pedersen, HB Vejby-Christensen, L Djuric, N AF Andersen, LH Jensen, MJ Pedersen, HB Vejby-Christensen, L Djuric, N TI Electron-impact detachment from B- SO PHYSICAL REVIEW A LA English DT Article ID MULTIPLE IONIZATION; IONS; RESONANCES; STATE; HE; H2 AB Cross sections for electron-impact single and double detachment from B- have been measured from 0 to 200 eV. The single-detachment cross section peaks at 4-5 eV with a cross-section maximum of about 10(-14) cm(2). A (2p(3)) S-4 state has recently been predicted to give rise to a resonance state in the H2- dianion [T. Sommerfeld et al., Phys. Rev. A 55 1903 (1997)]. We observe no resonances in the detachment cross section of B- and hence no sign of an equivalent shortlived B2-(2p(3)) state. The ratio of the double- to single-detachment cross section reaches a constant value of 3% at energies above 50 eV. A simple model relates this number to a shake-off probability of about 90%. The ratio between double and single ionization of neutral atomic targets at high energy is also discussed, and the model relates this ratio to the shake-off probability in the sudden approximation. [S1050-2947(98)09709-1]. C1 Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Andersen, LH (reprint author), Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. NR 28 TC 28 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1998 VL 58 IS 4 BP 2819 EP 2823 DI 10.1103/PhysRevA.58.2819 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 127WQ UT WOS:000076373900032 ER PT J AU Do, B Cha, JW Elliott, DS Smith, SJ AF Do, B Cha, JW Elliott, DS Smith, SJ TI Degenerate phase-conjugate four-wave mixing in a nearly-Doppler-free two-level atomic medium SO PHYSICAL REVIEW A LA English DT Article ID SODIUM VAPOR; 4-WAVE-MIXING SPECTROSCOPY; WAVEFRONT CONJUGATION; 4-WAVE; REGIME; COLLIMATION; OSCILLATION; SPECTRUM; PRESSURE; BEHAVIOR AB We present experimental observations of phase-conjugate degenerate four-wave mixing in a two-level atomic system (the 3s S-2(1/2), F = 2, m(F) = 2 --> 3p P-2(3/2), F = 3, m(F) = 3 transition in a diffuse, collision-free, thermal beam of atomic sodium) driven by cw, narrow-band (similar to 250 kHz), stabilized pump and probe fields. The primary measurements that we report are of the peak signal strength of the four-wave-mixing interaction and the bandwidth of the four-wave-mixing; spectrum (as the laser frequency is tuned through the resonant frequency) as a function of the intensity of the pump field. We compare these measurements with the predictions of a theoretical analysis in which extension to include the effect of the small transverse velocity (similar to 3 m/sec) of the atomic beam is critical. These measurements provide a direct verification of the theory of this important nonlinear interaction. [S1050-2947(98)06010-7]. C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Do, B (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NR 36 TC 9 Z9 9 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1998 VL 58 IS 4 BP 3089 EP 3098 DI 10.1103/PhysRevA.58.3089 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 127WQ UT WOS:000076373900063 ER PT J AU Zozulya, AA Diddams, SA Clement, TS AF Zozulya, AA Diddams, SA Clement, TS TI Investigations of nonlinear femtosecond pulse propagation with the inclusion of Raman, shock, and third-order phase effects SO PHYSICAL REVIEW A LA English DT Article ID ULTRASHORT LASER-PULSES; DISPERSIVE MEDIA; OPTICAL BEAMS; FIBERS; THRESHOLD AB The propagation of intense femtosecond pulses in a nonlinear, dispersive bulk medium is investigated numerically in the regime where the combined effects of diffraction, normal dispersion, and cubic nonlinearity lead to pulse splitting. We present numerical solutions of a modified (3 + 1)-dimensional nonlinear Schrodinger equation, accounting for the Raman effect, linear and nonlinear shock terms, third-order dispersion, and initial temporal third-order phase modulation. The calculated results are found to be in good agreement with experimental measurements. [S1050-2947(98)04410-2]. C1 Worcester Polytech Inst, Dept Phys, Worcester, MA 01609 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Zozulya, AA (reprint author), Worcester Polytech Inst, Dept Phys, 100 Inst Rd, Worcester, MA 01609 USA. RI Clement, Tracy/A-8885-2008; Diddams, Scott/L-2819-2013 NR 28 TC 72 Z9 78 U1 0 U2 7 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 OCT PY 1998 VL 58 IS 4 BP 3303 EP 3310 DI 10.1103/PhysRevA.58.3303 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 127WQ UT WOS:000076373900085 ER PT J AU Raithel, G Phillips, WD Rolston, SL AF Raithel, G Phillips, WD Rolston, SL TI Magnetization and spin-flip dynamics of atoms in optical lattices SO PHYSICAL REVIEW A LA English DT Article ID RESONANCE AB We show, experimentally and using quantum Monte Carlo simulations, that the quasithermal paramagnetic behavior of cesium atoms in a one-dimensional lin perpendicular to lin optical lattice is characterized by a spin temperature of twice the zero-field kinetic temperature. The magnetization is maximum and almost perfect when the Zeeman shift of the extreme magnetic sublevels approximately equals half the maximum light shift. The lifetime of magnetization and the laser-cooling time constant are found to be clearly distinct, the magnetization decay time amounting to at least three times the cooling time. Using simulations we find that the magnetic-dipole correlation time is approximately proportional to the angular momentum F of the atoms, while cooling and energy correlation time constants are approximately independent of F. Our results imply that for large F laser cooling within single light-shift potential wells (local cooling) occurs. [S1050-2947(98)51310-8]. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Raithel, G (reprint author), Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 10 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1998 VL 58 IS 4 BP R2660 EP R2663 DI 10.1103/PhysRevA.58.R2660 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 127WQ UT WOS:000076373900011 ER PT J AU Huang, Q Lynn, JW Erwin, RW Jarupatrakorn, J Cava, RJ AF Huang, Q Lynn, JW Erwin, RW Jarupatrakorn, J Cava, RJ TI Oxygen displacements and search for magnetic order in Sr3Ru2O7 SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; SR2RUO4 AB The crystal structure of the layered Sr3Ru2O7 system has been analyzed by neutron powder diffraction methods. The structure is formed by stacking two blocks of distorted SrRuO3 perovskite along the c axis, interleaved with SrO layers. The neighboring corner-sharing octahedra in each double perovskite block are rotated with respect to each other about the vertical axis so that the Ru-O-Ru angle in the RuO2 planes is about 165 degrees rather than 180 degrees. These rotations are correlated within each double perovskite block, but they are not correlated along the c axis, resulting in an intrinsic disorder that emphasizes the layered nature of this material. The resulting structure has the symmetry of space group Pban and lattice parameters a = b = 5.5016(1) Angstrom and c = 20.7194(5) Angstrom at 295 K. Data taken to 9 K showed no evidence of any structural phase transitions occurring below room temperature. We also searched for the development of long-range magnetic order to temperatures as low as 1.6 K, but no evidence of either ferromagnetic or antiferromagnetic long-range order was observed, with an upper limit of 0.05 mu(B) for any possible ordered moment. This result contrasts with a reported ferromagnetic ordering at 104 K with an ordered Ru moment of 1.3 mu(B), which we believe was due to a phase other than Sr3Ru2O7. We also searched for an induced moment, for applied fields up to 7 T, but did not observe any induced ferromagnetic moment within the same experimental limit. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. Princeton Univ, Mat Inst, Princeton, NJ 08540 USA. RP Huang, Q (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 16 TC 64 Z9 64 U1 2 U2 16 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 OCT 1 PY 1998 VL 58 IS 13 BP 8515 EP 8521 DI 10.1103/PhysRevB.58.8515 PG 7 WC Physics, Condensed Matter SC Physics GA 125HU UT WOS:000076232100061 ER PT J AU McMichael, RD Stiles, MD Chen, PJ Egelhoff, WF AF McMichael, RD Stiles, MD Chen, PJ Egelhoff, WF TI Ferromagnetic resonance studies of NiO-coupled thin films of Ni80Fe20 SO PHYSICAL REVIEW B LA English DT Article ID EXCHANGE-ANISOTROPY; CO/COO BILAYERS; MAGNETORESISTANCE; MULTILAYERS; INTERFACES; MODEL AB This paper describes ferromagnetic resonance (FMR) and magnetoresistive measurements of thin magnetic films coupled to antiferromagnetic films. First, FMR results for films of Ni80Fe20 show that coupling to NiO produces the angular variation in the resonance field of the type expected for unidirectional exchange anisotropy. However, unidirectional anisotropy values measured by in-plane ferromagnetic resonance are roughly 20% less than the loop shift measured via magnetoresistance. The difference is attributed in part to asymmetry in the coercivity. Second, in addition to the unidirectional anisotropy, coupling to NiO produces an isotropic negative resonance field shift that is larger than the exchange anisotropy field. This isotropic field shift is not consistent with models of exchange anisotropy in which the ferromagnet spins couple to a static antiferromagnet spin structure. It is consistent with the existence of a rotatable anisotropy, explained in terms of the energetics of domain configurations in the NiO. Third, using unpinned films as references, unidirectional anisotropy is measured for the first time with the magnetization rotated out of the film plane, and is found to be in reasonable agreement with in-plane measurements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McMichael, RD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM rmcmichael@nist.gov RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012; OI Stiles, Mark/0000-0001-8238-4156; McMichael, Robert/0000-0002-1372-664X NR 25 TC 174 Z9 175 U1 1 U2 23 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 OCT 1 PY 1998 VL 58 IS 13 BP 8605 EP 8612 DI 10.1103/PhysRevB.58.8605 PG 8 WC Physics, Condensed Matter SC Physics GA 125HU UT WOS:000076232100072 ER PT J AU Hyman, RA Zangwill, A Stiles, MD AF Hyman, RA Zangwill, A Stiles, MD TI Magnetic reversal on vicinal surfaces SO PHYSICAL REVIEW B LA English DT Article ID ULTRATHIN FILMS; FE FILMS; COBALT FILMS; ANISOTROPY; HYSTERESIS; W(110); ROUGHNESS; FE(110); AG(001); GROWTH AB We present ii theoretical study of in-plane magnetization reversal for vicinal ultrathin films using a one-dimensional micromagnetic model with nearest-neighbor exchange, fourfold anisotropy at all sites, and two-fold anisotropy at step edges. A detailed "phase diagram" is presented that catalogs the possible shapes of hysteresis loops and reversal mechanisms as a function of step anisotropy strength and vicinal terrace length. The steps generically nucleate magnetization reversal and pin the motion of domain walls. No sharp transition separates the cases of reversal by coherent rotation and reversal by depinning of a 90 degrees domain wall from the steps. Comparison to experiment is made when appropriate. [S0163-1829(98)08338-6]. C1 Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Natl Inst Stand & Technol, Elect Phys Grp, Gaithersburg, MD 20899 USA. RP Hyman, RA (reprint author), Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 40 TC 43 Z9 43 U1 1 U2 6 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 OCT 1 PY 1998 VL 58 IS 14 BP 9276 EP 9286 DI 10.1103/PhysRevB.58.9276 PG 11 WC Physics, Condensed Matter SC Physics GA 129WH UT WOS:000076486700063 ER PT J AU Slawecki, TM Glinka, CJ Hammouda, B AF Slawecki, TM Glinka, CJ Hammouda, B TI Shear-induced micellar crystal structures in an aqueous triblock copolymer solution SO PHYSICAL REVIEW E LA English DT Article ID NEUTRON-SCATTERING; PHASE; THERMODYNAMICS; MICELLIZATION; SUSPENSIONS; BEHAVIOR AB Shear-induced structures have been observed in aqueous solutions of the triblock copolymer PEO25PPO40PEO25 in the micellar crystalline region of the temperature-concentration phase diagram. A structure induced by steady shear, having two-dimensional (2D) hexagonal symmetry over macroscopic dimensions, transforms reversibly to a crystalline structure with different symmetry upon cessation of shear. Other structures are induced with oscillatory shear, including a 3D hexagonal phase with Bragg peaks that not only persist but sharpen with the cessation of shear. Over the range of temperature, concentration, and shear conditions investigated, no evidence for cubic or cubatic crystalline phases has been observed. [S1063-651X(98)50110-9]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Slawecki, TM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 16 TC 16 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD OCT PY 1998 VL 58 IS 4 BP R4084 EP R4087 DI 10.1103/PhysRevE.58.R4084 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 130RD UT WOS:000076533100009 ER PT J AU Rolston, S AF Rolston, S TI Optical lattices SO PHYSICS WORLD LA English DT Article ID ATOMS C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rolston, S (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 6 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD OCT PY 1998 VL 11 IS 10 BP 27 EP 32 PG 6 WC Physics, Multidisciplinary SC Physics GA 127GA UT WOS:000076341400036 ER PT J AU Stone, JA Howard, LP AF Stone, JA Howard, LP TI A simple technique for observing periodic nonlinearities in Michelson interferometers SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Article DE fringe interpolation; heterodyne interferometry; nanometrology; optical mixing; periodic nonlinearity; polarization mixing ID HETERODYNE INTERFEROMETERS; ERRORS AB We describe a simple, convenient method for measuring nonlinearities in displacement-measuring Michelson interferometers. Nonlinearities with a spatial periodicity of one optical fringe are a well-known source of error in precision interferometry. Our experimental technique for observing these errors is most immediately applicable to commercial interferometer systems for which the cube-corner retroreflectors can be attached directly to the faces of a beamsplitter cube, creating a monolithic interferometer optic with excellent noise immunity. The optical path difference in this bolted-together interferometer can be changed slightly by rotating the interferometer relative to an external laser. It should be noted that the basic principle described here-generating small path differences through a rotation of the optics relative to the laser-may itself be a source of significant errors in certain length measurements. The validity of our method has been demonstrated by measuring optical mixing errors of calculable magnitude. We describe a matrix method suitable for modeling optical mixing errors in both single-pass and double-pass (plane mirror) interferometers. Also, we report experimental measurements of periodic nonlinearities for two representative interferometers and conclude that, in the majority of engineering metrology applications, these errors are of only minor importance. Published by Elsevier Science Inc. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Stone, JA (reprint author), NIST, Div Precis Engn, Rm B113,Bldg 220,Quince Orchard Blvd, Gaithersburg, MD 20899 USA. NR 15 TC 33 Z9 39 U1 4 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD OCT PY 1998 VL 22 IS 4 BP 220 EP 232 DI 10.1016/S0141-6359(98)00016-6 PG 13 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA 140AM UT WOS:000077063400005 ER PT J AU Mandelman, D Schwarz, FP Li, HY Poulos, TL AF Mandelman, D Schwarz, FP Li, HY Poulos, TL TI The role of quaternary interactions on the stability and activity of ascorbate peroxidase SO PROTEIN SCIENCE LA English DT Article DE ascorbate peroxidase; differential scanning calorimetry; quaternary structure; salt bridges; solvent structure; subunit interface; thermostability ID DIFFERENTIAL SCANNING CALORIMETRY; TRIOSEPHOSPHATE ISOMERASE; ESCHERICHIA-COLI; PROTEIN; REPRESSOR; BINDING; MODEL; DIMER; SITE AB Point mutations at the dimer interface of the homodimeric enzyme ascorbate peroxidase (APx) were constructed to assess the role of quaternary interactions in the stability and activity of APx. Analysis of the APx crystal structure shows that Glu 112 forms a salt bridge with Lys20 and Arg24 of the opposing subunit near the axis of dyad symmetry between the subunits. Two point mutants, E112A and E112K, were made to determine the effects of a neutral (alanine) and repulsive (lysine) mutation on dimerization, stability, and activity. Gel filtration analysis indicated that the ratio of the monomer to dimer increased as the dimer interface interactions went from attractive to repulsive. Differential scanning calorimetry (DSC) data exhibited a decrease in both the transition temperature (T-m) and enthalpy of unfolding (Delta H-c) with T-m = 58.3 +/- 0.5 degrees C, 56.0 +/- 0.8 degrees C, and 53.0 +/- 0.9 degrees C and Delta H-c = 245 +/- 29 kcal/mol, 199 +/- 38 kcal/mol, and 170 +/- 25 kcal/mol for wild-type APx, E112A, and E112K, respectively. Similar changes were observed based on thermal melting curves obtained by absorption spectroscopy. No change in enzyme activity was found for the E112A mutant, and only a 25% drop in activity was observed for the E112K mutant which demonstrates that the non-Michaelis Menten kinetics of APx is not due to the APx oligomeric structure. The cryogenic crystal structures of the wild-type and mutant proteins show that mutation induced changes are limited to the dimer interface including an alteration in solvent structure. C1 Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Poulos, TL (reprint author), Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. FU NIGMS NIH HHS [GM07311-22, GM42614] NR 28 TC 33 Z9 33 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD OCT PY 1998 VL 7 IS 10 BP 2089 EP 2098 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 127YJ UT WOS:000076378000004 PM 9792095 ER PT J AU Woodgate, BE Kimble, RA Bowers, CW Kraemer, S Kaiser, ME Danks, AC Grady, JF Loiacono, JJ Brumfield, M Feinberg, L Gull, TR Heap, SR Maran, SP Lindler, D Hood, D Meyer, W VanHouten, C Argabright, V Franka, S Bybee, R Dorn, D Bottema, M Woodruff, R Michika, D Sullivan, J Hetlinger, J Ludtke, C Stocker, R Delamere, A Rose, D Becker, I Garner, K Timothy, JG Blouke, M Joseph, CL Hartig, G Green, RF Jenkins, EB Linsky, JL Hutchings, JB Moos, HW Boggess, A Roesler, F Weistrop, D AF Woodgate, BE Kimble, RA Bowers, CW Kraemer, S Kaiser, ME Danks, AC Grady, JF Loiacono, JJ Brumfield, M Feinberg, L Gull, TR Heap, SR Maran, SP Lindler, D Hood, D Meyer, W VanHouten, C Argabright, V Franka, S Bybee, R Dorn, D Bottema, M Woodruff, R Michika, D Sullivan, J Hetlinger, J Ludtke, C Stocker, R Delamere, A Rose, D Becker, I Garner, K Timothy, JG Blouke, M Joseph, CL Hartig, G Green, RF Jenkins, EB Linsky, JL Hutchings, JB Moos, HW Boggess, A Roesler, F Weistrop, D TI The Space Telescope Imaging Spectrograph design SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID DETECTORS AB The Space Telescope Imaging Spectrograph (STIS) instrument was installed on the Hubble Space Telescope (HST) during the second servicing mission, in 1997 February. Four bands cover the wavelength range of 115-1000 nm, with spectral resolving powers between 26 and 200,000. Camera modes are used for target acquisition and deep imaging. Correction for HST's spherical aberration and astigmatism is included. The 115-170 nm range is covered by a CsI MAMA (Multianode Microchannel Array) detector and the 165-310 nm range by a Cs,Te MAMA, each with a format of 2048 x 2048 pixels, while the 305-555 and 550-1000 nm ranges are covered by a single CCD with a format of 1024 x 1024 pixels. The multiplexing advantage of using these two-dimensional detectors compared with the 1 x 512 pixel detectors of the first-generation spectrographs is 1 or 2 orders of magnitude, depending on the mode used. The relationship between the scientific goals and the instrument specifications and design is discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ball Aerosp Technol Corp, Boulder, CO 80301 USA. York Univ, Ctr Res Earth & Space Sci, N York, ON M2N 5X2, Canada. SITe Corp, Beaverton, OR 97006 USA. Rutgers State Univ, Dept Phys, New Brunswick, NJ 08903 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Johns Hopkins Univ, Baltimore, MD 21218 USA. Catholic Univ Amer, Washington, DC 20064 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Nevada, Las Vegas, NV 89154 USA. RP Woodgate, BE (reprint author), NASA, Goddard Space Flight Ctr, Code 6681, Greenbelt, MD 20771 USA. EM woodgate@s2.gsfc.nasa.gov RI Gull, Theodore/D-2753-2012; Woodgate, Bruce/D-2970-2012; Kimble, Randy/D-5317-2012; heap, sara/E-2237-2012; Jenkins, Edward/P-5684-2014 OI Gull, Theodore/0000-0002-6851-5380; Jenkins, Edward/0000-0003-1892-4423 NR 20 TC 229 Z9 229 U1 0 U2 4 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD OCT PY 1998 VL 110 IS 752 BP 1183 EP 1204 DI 10.1086/316243 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 134LU UT WOS:000076745200007 ER PT J AU Podurets, KM Mildner, DFR Sharov, VA AF Podurets, KM Mildner, DFR Sharov, VA TI Application of capillary optics to neutron radiography SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LENS AB We propose two neutron radiographic techniques that make use of the converging beam from a tapered monolithic lens. The first is a focusing technique that enables one to obtain an image of a given cross section within an object. The second technique is neutron radiography that uses a beam emanating from a near point source. Both methods provide an improvement in spatial resolution for neutron radiography. (C) 1998 American Institute of Physics. [S0034-6748(98)04810-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Russian Res Ctr Kurchatov Inst, Moscow 123182, Russia. Xray Opt Syst Inc, Albany, NY 12203 USA. RP Podurets, KM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 1998 VL 69 IS 10 BP 3541 EP 3546 DI 10.1063/1.1149133 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 128VX UT WOS:000076430000011 ER PT J AU Arge, CN Mullan, DJ AF Arge, CN Mullan, DJ TI Modelling of magnetic interactions in partially-ionized gas: Application to the FIP effect SO SOLAR PHYSICS LA English DT Article ID AMBIPOLAR DIFFUSION; SOLAR ATMOSPHERE; MAGNETOHYDRODYNAMICS CODE; ELEMENTAL ABUNDANCES; PHOTOSPHERIC NETWORK; ENERGETIC PARTICLES; INTERSTELLAR-MEDIUM; ACTIVE REGIONS; QUIET SUN; CORONA AB We have adapted the ZEUS code to model magnetic interactions in partially ionized gas. When two regions of opposite polarity come into contact with each other, ions drifting in response to the Lorentz force fall into the minimum of the magnetic field, and then the drifting ions force the neutrals to take part in the Bow. Because of the finite time required for ion-atom collisions to occur, the gas which emerges from the interaction site has an ion/atom ratio which may be altered relative to that in the ambient medium. In order to model this effect, we adapt the Zeus code to a two-step iterative process involving a cycle between the hydrodynamic (HD) and the magnetohydrodynamic (MHD) versions of the code. The ion and atom fluids are coupled by collisions. Our simulations show that in chromospheric conditions, outflowing gas exhibits enhancements in ion/atom ratios which may be as large as a factor of 10 or more. The magnitude of the enhancements is determined by two key ratios which enter into the problem: the degree of ionization (n(i)/n(a)), and the plasma beta parameter. We show that, in the context of the mechanism we propose here, the amplitude of the ion/atom enhancements in the solar chromosphere is subject to a remarkable self-regulation because the ion density ni is almost invariant over the height range of interest to us. Our results are relevant in the context of the Sun, where the coronal abundances of elements with low first ionization potential (FIP) are systematically enhanced in certain magnetic structures. Although data for stars other than the Sun are sparse, we point out that our results are also useful for interpreting the available stellar data. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Space Environm Ctr, Boulder, CO USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Univ Colorado, CIRES, Boulder, CO 80309 USA. NR 51 TC 29 Z9 29 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD OCT PY 1998 VL 182 IS 2 BP 293 EP 332 DI 10.1023/A:1005096325238 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 144PE UT WOS:000077322300003 ER PT J AU Handwerker, CA AF Handwerker, CA TI Modelling and simulation for electronic packaging SO SOLDERING & SURFACE MOUNT TECHNOLOGY LA English DT Editorial Material C1 Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Handwerker, CA (reprint author), Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCB UNIV PRESS LTD PI BRADFORD PA 60/62 TOLLER LANE, BRADFORD BD8 9BY, W YORKSHIRE, ENGLAND SN 0954-0911 J9 SOLDER SURF MT TECH JI Solder. Surf. Mt. Technol. PD OCT PY 1998 VL 10 IS 3 BP 5 EP 5 PG 1 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA 161UP UT WOS:000078308300001 ER PT J AU Gordon, CJ Yang, Y Ramsdell, JS AF Gordon, CJ Yang, Y Ramsdell, JS TI Behavioral thermoregulatory response to maitotoxin in mice SO TOXICON LA English DT Article ID BODY-TEMPERATURE; CIGUATOXIN; CIGUATERA; INJURY; RAT AB Many types of marine algal toxins induce marked hypothermic responses in mice. However, it is not known if the thermoregulatory response to these toxins results from dysfunction in the control of core temperature (T-c) or is a coordinated response to lower T-c as occurs with a variety of xenobiotic insults. Female CD-1 mice were administered purified maitotoxin (338 ng/kg; IP) and placed in a temperature gradient for 5 h that permitted the selection of ambient temperatures (T-a) ranging between 15 and 37 degrees C, T-c was monitored simultaneously by radiotelemetric probes that were surgically implanted into the abdominal cavity at least one week before maitotoxin injection. Maitotoxin led to a rapid reduction in T-c from 37 to 34 degrees C within 30 min after injection. There was a simultaneous 4 degrees C reduction in T-a selected by mice within 15 min after injection. Selected T-a recovered rapidly, increased above baseline for approximately one hour, then remained near baseline levels for the remainder of the test period in the gradient. T-c remained approximately 1 to 2 degrees C below control levels throughout the test period. In the temperature gradient, mice can select T-a's warm enough to offset the hypothermic effects of maitotoxin. That cooler T-a's are selected initially after maitotoxin injection suggest that the central neural control of body temperature is affected by the toxin, We postulate that the hypothermic response may represent an adaptive response to enhance survival following exposure to polyether toxins. Published by Elsevier Science Ltd. C1 US EPA, Div Neurotoxicol, Natl Hlth & Environm Effects Res Lab, Res Triangle Pk, NC 27711 USA. Minist Publ Hlth, Beijing, Peoples R China. Med Univ S Carolina, Charleston Lab, NOAA, SE Fisheries Sci Ctr, Charleston, SC 29412 USA. RP Gordon, CJ (reprint author), US EPA, Div Neurotoxicol, Natl Hlth & Environm Effects Res Lab, Res Triangle Pk, NC 27711 USA. NR 18 TC 7 Z9 7 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0041-0101 J9 TOXICON JI Toxicon PD OCT PY 1998 VL 36 IS 10 BP 1341 EP 1347 DI 10.1016/S0041-0101(98)00010-5 PG 7 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 108JX UT WOS:000075263700003 PM 9723833 ER PT J AU Winchell, M Gupta, HV Sorooshian, S AF Winchell, M Gupta, HV Sorooshian, S TI On the simulation of infiltration- and saturation-excess runoff using radar-based rainfall estimates: Effects of algorithm uncertainty and pixel aggregation SO WATER RESOURCES RESEARCH LA English DT Article ID SENSITIVITY; MODELS; VARIABILITY; ACCURACY; SCALE; RESOLUTION; SYSTEM; IMPACT; ERRORS; BASIN AB The effects of uncertainty in radar-estimated precipitation input on simulated runoff generation from a medium-sized (100-km(2)) basin in northern Texas are investigated. The radar-estimated rainfall was derived from Next Generation Weather Radar (NEXRAD) Level II base reflectivity data and was supplemented by ground-based rain-gauge data. Two types of uncertainty in the precipitation estimates are considered: (1) those arising from the transformation of reflectivity to rainfall rate and (2) those due to the spatial and temporal representation of the "true" rainfall field. The study explicitly differentiates between the response of simulated saturation-excess runoff and infiltration-excess runoff to these uncertainties. The results indicate that infiltration-excess runoff generation is much more sensitive than saturation-excess runoff generation to both types of precipitation uncertainty. Furthermore, significant reductions in infiltration-excess runoff volume occur when the temporal and spatial resolution of the precipitation input is decreased. A method is developed to relate this storm-dependent reduction in runoff volume to the spatial heterogeneity of the highest-intensity rainfall periods during a storm. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RP Winchell, M (reprint author), Natl Weather Serv, NE River Forecast Ctr, Taunton, MA 02780 USA. RI Gupta, Hoshin/D-1642-2010; sorooshian, soroosh/B-3753-2008 OI Gupta, Hoshin/0000-0001-9855-2839; sorooshian, soroosh/0000-0001-7774-5113 NR 48 TC 95 Z9 96 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD OCT PY 1998 VL 34 IS 10 BP 2655 EP 2670 DI 10.1029/98WR02009 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 124UN UT WOS:000076200900018 ER PT J AU Levicky, R Herne, TM Tarlov, MJ Satija, SK AF Levicky, R Herne, TM Tarlov, MJ Satija, SK TI Using self-assembly to control the structure of DNA monolayers on gold: A neutron reflectivity study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PERSISTENCE LENGTH; LATEX-PARTICLES; TETHERED CHAINS; NUCLEIC-ACIDS; HYBRIDIZATION; SURFACE; OLIGONUCLEOTIDES; CONFORMATION; ELECTRODE; ARRAYS AB Neutron reflectivity was used to determine the concentration profiles of oligomeric DNA monolayers on gold in high salt concentrations (1 M NaCl). These monolayers are of interest as models for DNA probe systems used in diagnostic devices. go facilitate its attachment, the DNA was functionalized at the 5' end with a thiol group connected to the oligonucleotide by a hexamethylene linker. Concentration profiles determined from neutron reflectivity indicate that adsorbed layers of single-stranded DNA (HS-ssDNA) on bare gold are compact, suggesting the presence of multiple contacts between each DNA strand and the surface. After treatment with mercaptohexanol, a short alkanethiol with a terminal hydroxy group, the DNA "stands up" and extends farther into the solvent phase. These changes are consistent with the DNA remaining attached through its thiol end group while contacts between DNA backbones and the surface are prevented by the formation of a mercaptohexanol monolayer. The end-tethered HS-ssDNA layer readily hybridized to its complementary sequence, resulting in DNA helices with a preferred orientation toward the substrate normal. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Tarlov, MJ (reprint author), NIST, Chem Sci & Technol Lab, Bldg 221-A303, Gaithersburg, MD 20899 USA. EM michael.tarlov@nist.gov NR 33 TC 516 Z9 525 U1 6 U2 100 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 30 PY 1998 VL 120 IS 38 BP 9787 EP 9792 DI 10.1021/ja981897r PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 125EV UT WOS:000076225200008 ER PT J AU Bach, RD Glukhovtsev, MN Gonzalez, C AF Bach, RD Glukhovtsev, MN Gonzalez, C TI High-level computational study of the stereoelectronic effects of substituents on alkene epoxidations with peroxyformic acid SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-STATE GEOMETRIES; DENSITY-FUNCTIONAL THEORY; QUADRATIC CONFIGURATION-INTERACTION; AB-INITIO MO; HARTREE-FOCK; ELECTRON CORRELATION; PERTURBATION-THEORY; MOLLER-PLESSET; ENERGIES; THERMOCHEMISTRY AB The epoxidations of propene and isobutene with peroxyformic acid proceed by a concerted pathway via slightly unsymmetrical transition structures where the differences in the bond distances between the double-bond carbons and the spiro oxygen are only 0.021 and 0.044 Angstrom at the QCISD/6-31G* level. In contrast, the more polarizable nature of the carbon-carbon double bond of alpha,beta-unsaturated systems results in an unsymmetrical transition structure for the epoxidation of 1,3-butadiene with an order of magnitude difference in the carbon-oxygen bond distances of 0.305 Angstrom at the QCISD/6-31G* level. A highly unsymmetrical transition structure has been also found at this level for the epoxidation of acrylonitrile. Notwithstanding the difference in the extent of asymmetry of the transition structures, both epoxidations of methyl-substituted alkenes and such alpha,beta-unsaturated systems as 1,3-butadiene and acrylonitrile with peroxyformic acid follow a concerted asynchronous pathway. An unsymmetrical transition structure for 1,3-butadiene epoxidation and the concerted nature of the oxygen-transfer step are consistent with calculated kinetic isotope effects. The closeness of the barriers for propene and 1,3-butadiene epoxidations supports the conclusion that the reactions have similar mechanisms albeit they differ in the extent of asynchronous character of their transition structures. Methyl substitution leads to a decrease in the epoxidation barriers from 18.8 kcal/mol for ethylene to 13.7 kcal/mol for isobutene at the QCISD(T)/6-31G*//QCISD/6-31G* level. While the activation barrier for the epoxidation of I,3-butadiene with peroxyformic acid (15.9 and 11.7 kcal/mol at the QCISD(T)/6-31G* and B3LYP/6-31G* levels, respectively) is close to that for propane epoxidation (16.0 and 12.0 kcal/mol at the QCISD(T) and B3LYP levels, respectively), the barrier for acrylonitrile epoxidation is higher (21.0 kcal/mol at the QCISD(T)/6-31G* level). This increase in barrier height reflects the decreased nucleophilicity of double bonds bearing electron-withdrawing substituents. The energy differences between syn and anti configurations of the transition structures for the epoxidations of 1,3-butadiene and acrylonitrile with peroxyformic acid are very small (0.1-0.3 kcal/mol). C1 Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Bach, RD (reprint author), Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. EM rbach@udel.edu; mng@udel.edu; cgonzale@email.nist.gov NR 73 TC 62 Z9 63 U1 0 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 30 PY 1998 VL 120 IS 38 BP 9902 EP 9910 DI 10.1021/ja980495g PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 125EV UT WOS:000076225200022 ER PT J AU Cheng, L Sturchio, NC Woicik, JC Kemner, KM Lyman, PF Bedzyk, MJ AF Cheng, L Sturchio, NC Woicik, JC Kemner, KM Lyman, PF Bedzyk, MJ TI High-resolution structural study of zinc ion incorporation at the calcite cleavage surface SO SURFACE SCIENCE LA English DT Letter DE adsorption; calcite; surface extended x-ray absorption fine structure (SEXAFS); surface structure; X-ray standing waves (XSW); zinc ID RAY STANDING WAVES; SPECTROSCOPY; ADSORPTION; WATER AB The atomic-scale structure of Zn2+ incorporated at the CaCO3 (10 (1) over bar 4) surface by adsorption from solution was determined by X-ray standing wave triangulation and surface extended X-ray absorption fine structure spectroscopy. At low coverage (approximately 0.1 ML), Zn2+ substitutes for Ca2+ in the surface layer. Structural relaxation of the adjacent in-plane CO32- ions in the host surface is shown by the reduced nearest-neighbor distance of Zn-O relative to Ca-O. Relaxation of the Zn2+ ion in the out-of-plane direction is shown by the displacement of its lattice position from the ideal Ca2+ position. These relaxations, resulting in a local lattice buckling feature at the Zn2+ adsorption site, can be fully explained as the combined effect of the electrostatic relaxation of the nearest-neighbor anions in response to the smaller size of Zn2+, and the bonding asymmetry due to surface truncation. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Sturchio, NC (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. EM sturchio@anl.gov RI Bedzyk, Michael/B-7503-2009; Cheng, Likwan/C-1436-2013; Bedzyk, Michael/K-6903-2013 NR 19 TC 22 Z9 24 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 30 PY 1998 VL 415 IS 1-2 BP L976 EP L982 DI 10.1016/S0039-6028(98)00545-7 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 132RZ UT WOS:000076645000002 ER PT J AU Zhang, ZM Kumar, AR Boychev, VA Tanner, DB Vale, LR Rudman, DA AF Zhang, ZM Kumar, AR Boychev, VA Tanner, DB Vale, LR Rudman, DA TI Back-side reflectance of high T-c superconducting thin films in the far infrared SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL-CONSTANTS; YBA2CU3O7; TRANSMITTANCE; SPECTRA AB We have measured the far-infrared reflectance of YBaCu3O7-delta high T-c superconducting (HTS) films, for radiation incident on the substrate side (back- side illumination), in the spectral region from 15 to 650 cm(-1) and at temperatures between 10 and 300 K. The HTS films were deposited on Si substrates (with YSZ/CeO2 buffer layers) by pulsed laser ablation. The extremely large temperature dependence of the reflectance experimentally demonstrates the feasibility of using HTS films to construct far-infrared intensity modulators. In this letter, we present the measured results, as well as an analysis based on thin-film optics and a simple two-fluid model. (C) 1998 American Institute of Physics. [S0003-6951(98)04039-X]. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Zhang, ZM (reprint author), Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. EM zzhang@cimar.me.ufl.edu NR 24 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 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 28 PY 1998 VL 73 IS 13 BP 1907 EP 1909 DI 10.1063/1.122322 PG 3 WC Physics, Applied SC Physics GA 124JZ UT WOS:000076180300051 ER PT J AU Gadzuk, JW AF Gadzuk, JW TI Breathing mode excitation in near-harmonic systems: resonant mass capture, desorption and atoms in optical lattices SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Review ID ELECTRON MEDIATED PHOTODESORPTION; TIME-RESOLVED MEASUREMENT; DRIVEN SURFACE-REACTIONS; LASER-INDUCED DESORPTION; QUANTUM WAVE-PACKETS; STIMULATED DESORPTION; SCHRODINGER-EQUATION; TUNNELING ELECTRONS; MOLECULAR PROCESSES; ADSORBED MOLECULES AB The phenomenon of breathing mode excitation or bound-state wavepacket squeezing and spreading driven by a time-dependent oscillator frequency (due to either a transient force constant or mass) is considered here. An easily implemented theory of stimulated wavepacket dynamics for near-harmonic systems is presented which describes a variety of generic time dependences such as single sudden excitation, double switching (excitation/time delay/de-excitation) and decaying initially excited states which characterize many processes in spectroscopy, pump-probe control in intramolecular dynamics, and femtochemistry. The model is used as the theoretical basis for understanding such diverse phenomena as quantum excitation due to temporary neutron capture, stimulated bond-breaking resulting in delocalization, desorption, or dissociation, and breathing mode excitation of ultracold atoms trapped in optical lattices. Whilst the first two examples are speculative, results for transient wavepacket dynamics of the occupied excited optical lattice are in accord with recent experimental observations reported by the NIST Laser Cooling Group. Emphasis on the inherent theoretical simplicity and the multidisciplinary aspects of near-harmonic breathing mode excitation, as exemplified by the specific realizations considered here, has been a major intent of this topical review. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gadzuk, JW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 143 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 28 PY 1998 VL 31 IS 18 BP 4061 EP 4084 DI 10.1088/0953-4075/31/18/007 PG 24 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 126HT UT WOS:000076288400007 ER PT J AU Shkunov, VV Anderson, DZ AF Shkunov, VV Anderson, DZ TI Radiation transfer model of self-trapping spatially incoherent radiation by nonlinear media SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOREFRACTIVE SCREENING SOLITONS; LIGHT-BEAMS; PROPAGATION; INSTABILITY AB We modify the radiation transfer approach, accounting for refraction, and apply this model to the analysis of propagation of spatially incoherent beams in inertial nonlinear media. For double Gaussian beams, an oscillatory regime of nonlinear diffraction is revealed. An explicit analysis of the oscillations was carried out for logarithmic saturating nonlinearity. We show that "big incoherent solitons," which possess an arbitrary transverse profile of intensity and exist for a wide class of nonlinear media, are steady state solutions of the radiation transfer equation. [S0031-9007(98)07197-X]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Russian Acad Sci, Inst Problems Mech, Moscow, Russia. RP Shkunov, VV (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 26 TC 76 Z9 77 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 SEP 28 PY 1998 VL 81 IS 13 BP 2683 EP 2686 DI 10.1103/PhysRevLett.81.2683 PG 4 WC Physics, Multidisciplinary SC Physics GA 123PJ UT WOS:000076133300016 ER PT J AU Betts, AK Viterbo, P Beljaars, A Pan, HL Hong, SY Goulden, M Wofsy, S AF Betts, AK Viterbo, P Beljaars, A Pan, HL Hong, SY Goulden, M Wofsy, S TI Evaluation of land-surface interaction in ECMWF and NCEP/NCAR reanalysis models over grassland (FIFE) and boreal forest (BOREAS) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GLOBAL CLIMATE AB The National Center for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) and European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis models ate compared with First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE) grassland data from Kansas in 1987 and Boreal Ecosystem-Atmosphere Study (BOREAS) data from an old black spruce site in 1996 near Thompson, Manitoba. Some aspects of the comparison are similar for the two ecosystems. Over grassland and after snowmelt in the boreal forest, both models represent the seasonal cycle of near-surface temperature well. The two models have quite different soil hydrology components. The ECMWF model includes soil water nudging based on low level humidity errors. While this works quite well for the FIFE grassland, it appears to give too high evaporation over the boreal forest. The NCEP/NCAR model constrains long-term drifts by nudging deep soil water toward climatology. Over the FIFE site, this seems to give too low evaporation in midsummer, while at the BOREAS site, evaporation in this model is high. Both models have some difficulty representing the surface diurnal cycle of humidity. In the NCEP/NCAR reanalysis this leads to errors primarily in June, when the surface boundary layer stays saturated and too much precipitation occurs. In the ECMWF reanalysis there is a morning peak of mixing ratio, which an earlier work showed resulted from too shallow a boundary layer in the morning. Over the northern boreal forest there are important physical processes, which are not represented in either reanalysis model. In particular very high model albedos in spring, when there is snow under the forest canopy, lead to a very low daytime net radiation. This in turn leads to a large underestimate of the daytime surface fluxes, particularly the sensible heat flux, and to daytime model surface temperatures that are as much as 15 K low. In addition, the models do not account for the reduction in evaporation associated with frozen soil, and they generally have too large evapotranspiration in June and July, probably because they do not model the tight stomatal control of the coniferous forest. C1 NCEP, EMC, Camp Springs, MD 20746 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif Irvine, Irvine, CA 92717 USA. ECMWF, Reading, Berks, England. RP Betts, AK (reprint author), 58 Hendee Lane, Pittsford, VT 05763 USA. EM akbetts@aol.com RI Goulden, Michael/B-9934-2008; Viterbo, Pedro/B-7184-2008; Hong, Song-You/I-3824-2012 OI Viterbo, Pedro/0000-0001-6587-3062; NR 23 TC 47 Z9 49 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 SEP 27 PY 1998 VL 103 IS D18 BP 23079 EP 23085 DI 10.1029/98JD02023 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126PT UT WOS:000076302900002 ER PT J AU Frisch, AS Feingold, G Fairall, CW Uttal, T Snider, JB AF Frisch, AS Feingold, G Fairall, CW Uttal, T Snider, JB TI On cloud radar and microwave radiometer measurements of stratus cloud liquid water profiles SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE STRATOCUMULUS; DOPPLER RADAR AB We show a method for determining stratus cloud liquid water profiles using a microwave radiometer and cloud radar. This method is independent of the radar calibration and the cloud-droplet size distribution provided that the sixth moment of the size distribution can be related to the square of the third moment. We have calculated these moments with a wide variety of in situ measurements and show that this is a reasonable assumption. Examples of droplet distributions that meet this requirement are the lognormal and gamma distributions. C1 NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Colorado State Univ, NOAA, Environm Technol Lab, Cooperat Inst Res Atmosphere, Boulder, CO USA. Colorado State Univ, NOAA, Environm Technol Lab, Cooperat Inst Res Environm Sci, Boulder, CO USA. RP Frisch, AS (reprint author), NOAA, ERL, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. EM sfrish@etl.noaa.gov; gfeingold@etl.noaa.gov; cfairall@etl.noaa.gov; tuttal@etl.noaa.gov; jsnider@etl.noaa.gov RI Feingold, Graham/B-6152-2009 NR 12 TC 65 Z9 65 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 1998 VL 103 IS D18 BP 23195 EP 23197 DI 10.1029/98JD01827 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126PT UT WOS:000076302900011 ER PT J AU Ramaswamy, V Freidenreich, SM AF Ramaswamy, V Freidenreich, SM TI A high-spectral resolution study of the near-infrared solar flux disposition in clear and overcast atmospheres SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; CLOUDY ATMOSPHERES; ABSORPTION; RADIATION; PARAMETERIZATION; SURFACE; MODEL; DROPS AB The sensitivity of the near-infrared spectral atmospheric and surface fluxes to the vertical location of clouds is investigated, including a study of factors (drop-size distribution, drop optical depth, solar zenith angle, cloud geometrical thickness, atmospheric profiles) which govern this dependence. Because of the effects of the above-cloud, in-cloud and below-cloud water vapor the atmospheric absorbed flux in each spectral band depends critically on the cloud location, with a high cloud resulting in lesser absorption and greater reflection than a low one having the same drop optical depth. The difference between a high and a low cloud forcing of atmospheric absorption increases with drop optical depth. For any optical depth, clouds with larger drops cause a greater forcing of the spectral atmospheric absorption than those with smaller ones, so high clouds can even cause an increase rather than a decrease of the atmospheric absorption relative to clear skies. In contrast, the spectral and total surface fluxes are relatively insensitive to cloud vertical location. Instead, they are determined by the drop characteristics, notably drop optical depth. This near-invariance characteristic is attributable to the fact that most of the insolation reaching the surface is in the weak water vapor spectral absorption regions; here drops dominate the radiative interactions and thus there is little dependence on cloud height. In addition, the overlap of the drop spectral features with the moderate-to-strong vapor absorption bands ensures that insolation in these regimes fails to reach the surface no matter where the cloud is located; instead, these bands contribute the most to atmospheric absorption. The near-invariant behavior of the spectral and total surface flux holds separately for a wide variety of conditions studied. As a consequence, the difference in reflection, between two columns containing clouds with the same optical depth but located at different altitudes, is approximately balanced in magnitude by the difference in the atmospheric absorption; this holds for every spectral interval whether it be a weak, moderate, or strong vapor/drop absorption band. It also follows that the net fluxes at the top and surface of overcast atmospheres do not have a general, unambiguous relationship; this is in sharp contrast to a linear relation between them in clear skies. However, under certain overcast conditions (e.g., specific vertical location of clouds and solar zenith angle), a simple linear relationship is plausible. C1 NOAA, GFDL, Princeton, NJ 08542 USA. RP Ramaswamy, V (reprint author), NOAA, GFDL, POB 308, Princeton, NJ 08542 USA. EM vr@gfdl.gov NR 19 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 1998 VL 103 IS D18 BP 23255 EP 23273 DI 10.1029/98JD02379 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126PT UT WOS:000076302900017 ER PT J AU Erlick, C Frederick, JE AF Erlick, C Frederick, JE TI Effects of aerosols on the wavelength dependence of atmospheric transmission in the ultraviolet and visible 2. Continental and urban aerosols in clear skies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTHROPOGENIC AEROSOLS; RADIATION BUDGET; REFRACTIVE-INDEX; SULFATE; SCATTERING; MODEL; CLOUD; SIZE AB In this study we model the effects of continental and urban aerosols and their variation with humidity on the transmission of ultraviolet and visible radiation to the Earth's surface. Normalizing the transmission to that of an aerosol-free atmosphere, we examine the mechanisms behind two wavelength-dependent aerosol effects. The first is a dip in the normalized transmission at wavelengths below around 320 nm, which is caused by a coupling between multiple scattering by the aerosol particles and absorption by ozone and by the rapidly increasing absorption coefficient of tropospheric water-soluble aerosols below 340 nm, based on limited available refractive index data in the UV. The second effect is an increase in normalized transmission with wavelength from 320 nm through the visible, which is caused by the decrease with wavelength in the Mie scattering coefficients of tropospheric water-soluble, soot, and stratospheric sulfate aerosols. Using our continental aerosol model, at 0% relative humidity we compute aerosol optical depths of 0.72 at 310 nm and 0.35 at 550 nm,which reduce atmospheric transmission by 12.8% at 310 nm and by 7.9% at 550 nm. With our urban aerosol model we compute aerosol optical depths of 1.82 at 310 nm and 0.87 at 550 nm, which reduce transmission by 34.5% at 310 nm and by 21.1% at 550 nm. Absorption by the aerosols is a significant contributor to this, reducing transmission by 20.9% at 310 nm and by 8.6% at 550 nm beyond nonabsorbing aerosols. For average summer humidity conditions our continental aerosol model predicts an increase in optical depth to 1.26 at 310 nm and to 0.65 at 550 nm, leading to a reduction in transmission of 15.2% at 310 nm and 9.7% at 550 nm, as compared with an aerosol-free atmosphere. For average summer humidity conditions our urban aerosol model predicts an increase in optical depth to 3.22 at 310 nm and to 1.65 at 550 nm, leading to a reduction in transmission of 40.0% at 310 nm and 25.3% at 550 nm, as compared with an aerosol-free atmosphere. Comparison with ground-based data indicates that our estimated optical depths are toward the high end of values seen for continental aerosols, being more typical of industrial than rural areas. C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Erlick, C (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Forrestal Campus,Route 1, Princeton, NJ 08542 USA. EM cee@gfdl.gov; frederic@sunbeam.uchicago.edu NR 50 TC 23 Z9 23 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 SEP 27 PY 1998 VL 103 IS D18 BP 23275 EP 23285 DI 10.1029/98JD02119 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126PT UT WOS:000076302900018 ER PT J AU Mazur, V Ruhnke, LH AF Mazur, V Ruhnke, LH TI Model of electric charges in thunderstorms and associated lightning SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PARAMETERIZATION AB An axisymmetrical electrostatic model of charges in a thunderstorm cloud at the mature stage is used to initiate a bidirectional vertical leader that develops into either a cloud-to-ground or an intracloud flash from the regions of maximum electric field. The principal result of this study is the determination of the physical and quantitative relationships among cloud charges, potentials, and electric fields, and the induced charges, currents, and electric field changes of the lightning channel from the numerical solution of the Poisson equation for a cloud charge model with lightning. An important consequence of the model is that the upper part of the cloud-to-ground leader and the lower part of the intracloud leader terminate inside the cloud. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Mazur, V (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM mazur@nssl.noa.gov NR 41 TC 58 Z9 63 U1 1 U2 14 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 SEP 27 PY 1998 VL 103 IS D18 BP 23299 EP 23308 DI 10.1029/98JD02120 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 126PT UT WOS:000076302900020 ER PT J AU Rabeony, M Lohse, DJ Garner, RT Han, SJ Graessley, WW Migler, KB AF Rabeony, M Lohse, DJ Garner, RT Han, SJ Graessley, WW Migler, KB TI Effect of pressure on polymer blend miscibility: A temperature-pressure superposition SO MACROMOLECULES LA English DT Article ID SATURATED-HYDROCARBON POLYMERS; THERMODYNAMIC INTERACTIONS; POLYOLEFIN BLENDS; MIXING BEHAVIOR; DEPENDENCE; MIXTURES AB In this paper, we report on how interaction strength varies with pressure and temperature for several polyolefin mixtures. We find that the interaction energies that govern phase behavior in polymer blends are only a function of density for UCST polyolefin blends far from a critical point. As a result, the effects of pressure on miscibility can be predicted for such blends from knowledge of the effects of temperature on the interactions combined with PVT data. This remarkable simplification appears to be related to the van der Waals nature of the interactions between saturated hydrocarbons. Density dependence predicts the trends correctly for LCST polyolefin blends, but for these mixtures the interactions depend in a more complex way on T and P. C1 Exxon Res & Engn Co, Corp Res Labs, Annandale, NJ 08801 USA. Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Lohse, DJ (reprint author), Exxon Res & Engn Co, Corp Res Labs, Route 22 E, Annandale, NJ 08801 USA. NR 15 TC 35 Z9 37 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 22 PY 1998 VL 31 IS 19 BP 6511 EP 6514 DI 10.1021/ma980723r PG 4 WC Polymer Science SC Polymer Science GA 123LW UT WOS:000076127500018 ER PT J AU Williams, ER Steiner, RL Newell, DB Olsen, PT AF Williams, ER Steiner, RL Newell, DB Olsen, PT TI Accurate measurement of the Planck constant SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRICAL MEASUREMENTS; WATT; BALANCE; MASS AB Using a moving coil watt balance, electric power measured in terms of the Josephson and quantum Hall effects is compared with mechanical power measured in terms of the meter, kilogram, and second. We find the Planck constant h = 6.62606891(58) x 10(-34) Js. The quoted standard uncertainty (1 standard deviation estimate) corresponds to (8.7 x 10(-8))h. Comparing this measurement to an earlier measurement places an upper limit of 2 x 10(-8)/yr on the drift rate of the SI unit of mass, the kilogram. [S0031-9007(98)07164-6]. C1 NIST, Gaithersburg, MD 20899 USA. RP Williams, ER (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 14 TC 119 Z9 122 U1 1 U2 16 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 SEP 21 PY 1998 VL 81 IS 12 BP 2404 EP 2407 DI 10.1103/PhysRevLett.81.2404 PG 4 WC Physics, Multidisciplinary SC Physics GA 122LM UT WOS:000076073100002 ER PT J AU Rye, BJ AF Rye, BJ TI Molecular backscatter heterodyne lidar: a computational evaluation SO APPLIED OPTICS LA English DT Article ID RAYLEIGH-BRILLOUIN SCATTERING; PARAMETERS; PROFILES AB The application of heterodyne lidar to observe molecular scattering is considered. Despite the reduced Rayleigh cross section, infrared systems are predicted to require mean power levels comparable with those of current and proposed direct detection Lidars that operate with the thermally broadened spectra in the visible or ultraviolet. Rayleigh-Brillouin scattering in the kinetic and hydrodynamic (collisional) regimes encountered in the infrared is of particular interest because the observed spectrum approaches a triplet of relatively narrow lines that are more suitable for wind, temperature, and pressure measurements. (C) 1998 Optical Society of America. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Rye, BJ (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, R-E-ET2,325 Broadway, Boulder, CO 80303 USA. NR 21 TC 5 Z9 5 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 1998 VL 37 IS 27 BP 6321 EP 6328 DI 10.1364/AO.37.006321 PG 8 WC Optics SC Optics GA 121WH UT WOS:000076038400001 PM 18286130 ER PT J AU Cooper, OR Moody, JL Davenport, JC Oltmans, SJ Johnson, BJ Chen, X Shepson, PB Merrill, JT AF Cooper, OR Moody, JL Davenport, JC Oltmans, SJ Johnson, BJ Chen, X Shepson, PB Merrill, JT TI Influence of springtime weather systems on vertical ozone distributions over three North American sites SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE; ATLANTIC-OCEAN; UNITED-STATES; TRANSPORT; TROPOPAUSE; PROFILES; BERMUDA; SUMMER; BUDGET; MODEL AB The Atmosphere/Ocean Chemistry Experiment (AEROCE) '96 Springtime Intensive was designed to quantify major atmospheric chemical species transported from the United States east coast to the North Atlantic Ocean. During the study ozonesondes were launched almost every day between March 22 and May 3, 1996, from Charlottesville, Virginia; Purdue University, Indiana; and Bermuda. Whenever possible, the Charlottesville sondes were timed to fly behind passing cold fronts into midtropospheric to upper tropospheric bands of dry air. The dry air was hypothesized to contain ozone of stratospheric origin and was detected with color-enhanced satellite water vapor imagery. Soundings were placed in three categories: sondes launched ahead of an approaching cold front, sondes launched behind a passing cold front, and sondes launched into cutoff lows. This stratification explained much of the vertical ozone variation at each site. Tropospheric mean ozone increased with height at all three sites under postfrontal conditions, with relatively little increase with height under prefrontal conditions. Backward trajectories from Charlottesville indicated that the postfrontal air masses originated at high elevations to the northwest, while prefrontal air masses came from relatively lower elevations to the southwest. Transport also explained the lower tropospheric ozone differences between Charlottesville and Bermuda. The enhanced ozone observed in the upper troposphere over Charlottesville compared with the other sites may be linked to upwind conditions more favorable for tropopause folding. However, we believe that selective launching based on the operational use of satellite water vapor imagery allowed us to sample the full range of tropospheric ozone over Charlottesville. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Rhode Isl, Grad Sch Oceanog, Ctr Atmospher Chem Studies, Narragansett, RI 02882 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. RP Cooper, OR (reprint author), Univ Virginia, Dept Environm Sci, Clark Hall, Charlottesville, VA 22903 USA. EM orc3j@virginia.edu RI Shepson, Paul/E-9955-2012; Cooper, Owen/H-4875-2013 NR 45 TC 38 Z9 38 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 SEP 20 PY 1998 VL 103 IS D17 BP 22001 EP 22013 DI 10.1029/98JD01801 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400007 ER PT J AU Dvortsov, VL Geller, MA Yudin, VA Smyshlyaev, SP AF Dvortsov, VL Geller, MA Yudin, VA Smyshlyaev, SP TI Parameterization of the convective transport in a two-dimensional chemistry-transport model and its validation with radon 222 and other tracer simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; CLOUD TRANSPORT; TROPOSPHERE; OZONE; AIR AB Deep cumulus convection is essential for understanding and modeling of the atmospheric composition, providing a mechanism by which short-lived species can be quickly transported from the planetary boundary layer to the upper troposphere. Because it is a small scale process, highly irregular in time and space, so far most of the scientific community has been skeptical about the legitimacy of zonally averaged representations of tracer convective transport in two-dimensional (2-D) models. To justify and validate such an approach, we derive our parameterization of zonally averaged convective transport from a 3-D model and then validate our 2-D results against the results from that 3-D model using radon 222 and other tracer simulations. We show, both analytically and by comparing 2-D and 3-D model results, that straightforward substitution of zonally averaged parameters into the equations of tracer convective transport produces large errors because the intensity of the convection and the tracer concentration in the updraft and in the environment can be strongly correlated. If such correlations are taken into account in the zonally averaged equations for convective transport, the agreement between 2-D and 3-D results can be significantly improved. We show that our 2-D model with monthly mean convective mass fluxes, properly zonally averaged, is capable of reproducing, with reasonable accuracy, the time series of Rn-222 and other tracers obtained from the 3-D simulations. Our convective transport algorithm and input data are available via anonymous ftp. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Russian State Hydrometeorol Inst, St Petersburg 195196, Russia. RP Dvortsov, VL (reprint author), NOAA, Aeron Lab, 325 Broadway R-E-AL8, Boulder, CO 80303 USA. EM vdvor@dombai.uars.sunysb.edu NR 32 TC 11 Z9 12 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 SEP 20 PY 1998 VL 103 IS D17 BP 22047 EP 22062 DI 10.1029/98JD02084 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400010 ER PT J AU Borys, RD Lowenthal, DH Wetzel, MA Herrera, F Gonzalez, A Harris, J AF Borys, RD Lowenthal, DH Wetzel, MA Herrera, F Gonzalez, A Harris, J TI Chemical and microphysical properties of marine stratiform cloud in the North Atlantic SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTHROPOGENIC SULFATE; CONDENSATION-NUCLEI; AEROSOL-PARTICLES; DROPLET SIZE; AIR-QUALITY; ALBEDO; MODEL; METHANESULFONATE; POLLUTION AB The chemical and microphysical properties of marine stratiform cloud were measured at a ridgetop elevation of 992 m above mean sea level (AMSL) on Tenerife in the Canary Islands in the eastern North Atlantic during the summers of 1995 and 1996. The results show an inverse relationship between hourly-averaged cloud droplet diameter and droplet number concentration, which ranged from 116 to 1355 cm(-3). Strong relationships were observed between droplet number and equivalent clear air concentrations of non-sea-salt sulfate, nitrate, and elemental carbon in the droplets. Droplet sizes inferred from radiances measured by satellite for clouds offshore and upwind agreed with droplet sizes derived for clouds over the mountain sampling site, and also with those measured in cloud 4-5 hours later. Estimated cloud short-wave radiative forcing was enhanced by 8% in radiative model studies of polluted versus clean clouds with droplet concentrations of 786 and 127 cm(-3) and droplet effective radii of 6 and 10 mu m, respectively. C1 Desert Res Inst, Ctr Atmospher Sci, Reno, NV 89506 USA. Univ la Laguna, Dept Fundamental & Expt Phys, E-38207 San Cristobal de la Laguna, Canary Islands, Spain. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Borys, RD (reprint author), Desert Res Inst, Ctr Atmospher Sci, POB 60220, Reno, NV 89506 USA. EM borys@dri.edu; dougl@dri.edu; wetzel@dri.edu; therrera@ull.es; aglezf@ull.es; jharris@cdml.noaa.gov RI Gonzalez, Albano/L-5499-2014 OI Gonzalez, Albano/0000-0002-4045-5013 NR 35 TC 23 Z9 23 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 SEP 20 PY 1998 VL 103 IS D17 BP 22073 EP 22085 DI 10.1029/98JD02087 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400012 ER PT J AU Weinheimer, AJ Montzka, DD Campos, TL Walega, JG Ridley, BA Donnelly, SG Keim, ER Del Negro, LA Proffitt, MH Margitan, JJ Boering, KA Andrews, AE Daube, BC Wofsy, SC Anderson, BE Collins, JE Sachse, GW Vay, SA Elkins, JW Wamsley, PR Atlas, EL Flocke, F Schauffler, S Webster, CR May, RD Loewenstein, M Podolske, JR Bui, TP Chan, KR Bowen, SW Schoeberl, MR Lait, LR Newman, PA AF Weinheimer, AJ Montzka, DD Campos, TL Walega, JG Ridley, BA Donnelly, SG Keim, ER Del Negro, LA Proffitt, MH Margitan, JJ Boering, KA Andrews, AE Daube, BC Wofsy, SC Anderson, BE Collins, JE Sachse, GW Vay, SA Elkins, JW Wamsley, PR Atlas, EL Flocke, F Schauffler, S Webster, CR May, RD Loewenstein, M Podolske, JR Bui, TP Chan, KR Bowen, SW Schoeberl, MR Lait, LR Newman, PA TI Comparison between DC-8 and ER-2 species measurements in the tropical middle troposphere: NO, NOy, O-3, CO2, CH4, and N2O SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LOWER STRATOSPHERE; NITRIC-OXIDE; NITROGEN; AIRCRAFT; OZONE; DIOXIDE AB We compare measurements of six species taken aboard NASA DC-8 and ER-2 aircraft during two flight legs in the tropical middle troposphere near Hawaii. NO, NOy. O-3, CH4, and N2O measurements agree to within the limits set by the known systematic errors. For CO2, which can be measured with better relative precision than the other five species, differences in measured values from the two platforms are slightly larger than expected if the air masses sampled by the two aircraft were indeed similar in CO2 composition to better than 0.08%. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Harvard Univ, Div Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Ames Res Ctr, Earth Syst Sci Div, Moffett Field, CA 94035 USA. Sci & Technol Corp, Hampton, VA 23665 USA. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO 80302 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80302 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Biol & Chem, Boulder, CO 80309 USA. RP Weinheimer, AJ (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM wein@ucar.edu RI Newman, Paul/D-6208-2012; Andrews, Arlyn/K-3427-2012; Atlas, Elliot/J-8171-2015 OI Newman, Paul/0000-0003-1139-2508; NR 16 TC 15 Z9 15 U1 1 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 SEP 20 PY 1998 VL 103 IS D17 BP 22087 EP 22096 DI 10.1029/98JD01421 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400013 ER PT J AU Cowling, EB Chameides, WL Kiang, CS Fehsenfeld, FC Meagher, JF AF Cowling, EB Chameides, WL Kiang, CS Fehsenfeld, FC Meagher, JF TI Introduction to special section: Southern Oxidants Study Nashville Middle Tennessee Ozone Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; HYDROCARBONS; POLLUTION; ATLANTA C1 N Carolina State Univ, Coll Forest Resources, Raleigh, NC 27605 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Cowling, EB (reprint author), N Carolina State Univ, Coll Forest Resources, 1307 Glenwood Ave,Suite 157, Raleigh, NC 27605 USA. EM ellis_cowling@ncsu.edu; wcham@eas.gatech.edu; chia.kiang@eas.gatech.edu; fcf@al.noaa.gov; jmeagher@al.noaa.gov RI Fehsenfeld, Frederick/I-4876-2013 NR 15 TC 27 Z9 27 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 SEP 20 PY 1998 VL 103 IS D17 BP 22209 EP 22212 DI 10.1029/98JD01770 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400021 ER PT J AU Meagher, JF Cowling, EB Fehsenfeld, FC Parkhurst, WJ AF Meagher, JF Cowling, EB Fehsenfeld, FC Parkhurst, WJ TI Ozone formation and transport in southeastern United States: Overview of the SOS Nashville Middle Tennessee Ozone Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; NATURAL HYDROCARBONS; BIOGENIC HYDROCARBONS; PHOTOCHEMICAL SMOG; NITROGEN-OXIDES; REGIONAL OZONE; PROJECT MISTT; REMOTE SITE; URBAN PLUME; TROPOSPHERE AB The Southern Oxidants Study (SOS) is a public-private partnership collectively engaged, since 1989, in a coordinated program of policy-relevant research to improve scientific and public understanding of tropospheric ozone pollution. In the summers of 1994 and 1995, SOS implemented the Nashville/Middle Tennessee Ozone Study. This effort, the second SOS urban intensive study, conducted a series of integrated, process-oriented airborne and surface measurement experiments to better understand the chemistry and meteorology associated with the production, transport, and impact of tropospheric ozone. Specific technical objectives addressed (1) the role of biogenic VOC and NO, emissions on local and regional ozone production, (2) the effect of urban-rural exchange/interchange on local and regional ozone production, (3) sub-grid-scale photochemical and meteorological processes? and (4) the provision of a high-quality chemical and meteorological data set to test and improve observation- and emission-based air quality forecast models. Some of the more significant findings of the 1994-1995 studies include the following: (1) Ozone production in Nashville was found to be close to the transition between NOx-sensitive and VOC-sensitive chemistry. (2) Ozone production efficiency (OPE) in power plant plumes, molecules of ozone formed per molecule of NO, emitted, was found to be inversely proportion to NO, emission rate, with the plants having the greatest NOx, emissions exhibiting the lowest OPE. (3) During stagnant conditions, nighttime winds dominated pollutant transport and represent the major mechanism for transporting urban pollutants to rural areas. Ultimately, results provided by this research will allow improved assessment of existing ozone management strategies and provide better scientific tools for the development of future management strategies. C1 NOAA, Aeron Lab, MC, REAL, Boulder, CO 80303 USA. Tennessee Valley Author, ERC, Muscle Shoals, AL 35660 USA. N Carolina State Univ, Coll Forest Resources, So Oxidants Study, Raleigh, NC 27695 USA. RP Meagher, JF (reprint author), NOAA, Aeron Lab, MC, REAL, 325 Broadway, Boulder, CO 80303 USA. EM jmeagher@al.noaa.gov RI Fehsenfeld, Frederick/I-4876-2013 NR 56 TC 35 Z9 35 U1 3 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1998 VL 103 IS D17 BP 22213 EP 22223 DI 10.1029/98JD01693 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400022 ER PT J AU McNider, RT Norris, WB Song, AJ Clymer, RL Gupta, S Banta, RM Zamora, RJ White, AB Trainer, M AF McNider, RT Norris, WB Song, AJ Clymer, RL Gupta, S Banta, RM Zamora, RJ White, AB Trainer, M TI Meteorological conditions during the 1995 Southern Oxidants Study Nashville Middle Tennessee Field Intensive SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; MODEL; OZONE; OSCILLATIONS; PROFILER; RATES AB As a background for other papers presented in this issue on the 1995 Southern Oxidants Study (SOS) Nashville/Middle Tennessee Field Intensive, the role of meteorology in the field study is reviewed. Descriptions of the meteorological observing systems are given, and the strategy behind the observational network is defined. The tools used in making forecasts and their use for operational decisions are described. In particular, the use in real time of a dynamic boundary layer model coupled with a Lagrangian plume model to forecast power plant and urban plumes is examined. The weather occurring during the field intensive is summarized and put into a climatological perspective. Specific attention is given to the episodes of July 1-3 and July 10-14, 1995, when some of the highest ozone values were recorded. The role of nocturnal, low-level jets observed by the boundary layer wind profiler network in dispersing urban emissions into the regional background is explored. C1 Univ Alabama, Earth Syst Sci Lab, Huntsville, AL 35899 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP McNider, RT (reprint author), Univ Alabama, Earth Syst Sci Lab, Huntsville, AL 35899 USA. EM mcnider@atmos.uah.edu RI White, Allen/A-7946-2009; Trainer, Michael/H-5168-2013; Banta, Robert/B-8361-2008 NR 32 TC 22 Z9 22 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 SEP 20 PY 1998 VL 103 IS D17 BP 22225 EP 22243 DI 10.1029/98JD01203 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400023 ER PT J AU Hubler, G Alvarez, R Daum, P Dennis, R Gillani, N Kleinman, L Luke, W Meagher, J Rider, D Trainer, M Valente, R AF Hubler, G Alvarez, R Daum, P Dennis, R Gillani, N Kleinman, L Luke, W Meagher, J Rider, D Trainer, M Valente, R TI An overview of the airborne activities during the Southern Oxidants Study (SOS) 1995 Nashville Middle Tennessee Ozone Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB The cause and extent of elevated ozone levels which are often found during summer in the southeastern United States were the focus of the intensive Southern Oxidants Study (SOS) 1995 Nashville/Middle Tennessee Ozone Study. Six aircraft were extensively instrumented and were deployed in concert during the summer of 1995 from the Nashville Metropolitan Airport. This overview describes the capabilities of the deployed assets, and how their use was managed. Results from the measurements on individual aircraft and their interpretation are contained in the individual papers that follow. C1 NOAA, Aeron Lab, REAL7, Boulder, CO 80303 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. US EPA, NERL, Res Triangle Pk, NC 27711 USA. Tennessee Valley Author, Environm Res Ctr, Muscle Shoals, AL 35660 USA. NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hubler, G (reprint author), NOAA, Aeron Lab, REAL7, 325 Broadway, Boulder, CO 80303 USA. EM ghubler@al.noaa.gov RI Hubler, Gerhard/E-9780-2010; Trainer, Michael/H-5168-2013; Alvarez, Raul/I-4879-2013; Luke, Winston/D-1594-2016 OI Luke, Winston/0000-0002-1993-2241 NR 2 TC 24 Z9 24 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 SEP 20 PY 1998 VL 103 IS D17 BP 22245 EP 22259 DI 10.1029/98JD01638 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400024 ER PT J AU Williams, EJ Baumann, K Roberts, JM Bertman, SB Norton, RB Fehsenfeld, FC Springston, SR Nunnermacker, LJ Newman, L Olszyna, K Meagher, J Hartsell, B Edgerton, E Pearson, JR Rodgers, MO AF Williams, EJ Baumann, K Roberts, JM Bertman, SB Norton, RB Fehsenfeld, FC Springston, SR Nunnermacker, LJ Newman, L Olszyna, K Meagher, J Hartsell, B Edgerton, E Pearson, JR Rodgers, MO TI Intercomparison of ground-based NOy measurement techniques SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CATALYTIC REDUCTION TECHNIQUE; SOUTHEASTERN UNITED-STATES; ODD-NITROGEN NOY; ORGANIC NITRATES; OZONE PRODUCTION; TROPOSPHERE; PHOTOCHEMISTRY; COLORADO; BUDGET; SITE C1 NOAA, Aeron Lab, Environm Res Labs, Boulder, CO 80303 USA. Atmospher Res & Anal Inc, Durham, NC 27707 USA. Tennessee Valley Author, Dept Atmospher Sci, Muscle Shoals, AL 35662 USA. Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. Georgia Inst Technol, Air Qual Lab, Atlanta, GA 30332 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Environm Sci & Engn, Durham, NC USA. RP Williams, EJ (reprint author), NOAA, Aeron Lab, Environm Res Labs, 325 Broadway,R-E-AL7, Boulder, CO 80303 USA. EM eric@al.noaa.gov RI Roberts, James/A-1082-2009; Williams, Eric/F-1184-2010; Fehsenfeld, Frederick/I-4876-2013 OI Roberts, James/0000-0002-8485-8172; NR 25 TC 68 Z9 68 U1 0 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 SEP 20 PY 1998 VL 103 IS D17 BP 22261 EP 22280 DI 10.1029/98JD00074 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400025 ER PT J AU Luke, WT Watson, TB Olszyna, KJ Gunter, RL McMillen, RT Wellman, DL Wilkison, SW AF Luke, WT Watson, TB Olszyna, KJ Gunter, RL McMillen, RT Wellman, DL Wilkison, SW TI A comparison of airborne and surface trace gas measurements during the Southern Oxidants Study (SOS) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID COMMERCIAL NOX DETECTOR; HIGH-SENSITIVITY; NITRIC-ACID AB The NOAA Twin Otter conducted more than a dozen overflights of ground-level air quality monitoring stations during the 1995 Southern Oxidants Study (SOS) Nashville/Middle Tennessee Ozone Project Field Intensive. Surface and aircraft observations of ozone and ozone precursors were examined to identify systematic sampling errors, and to assess the degree to which surface measurements may be considered representative of the larger planetary boundary layer (PBL). Overall agreement between surface and aircraft trace gas measurements was excellent in the well developed mixed layer, especially in rural-regional background air and under stagnant conditions, where surface concentrations change only slowly. On July 2, surface level measurements were representative of the larger mixed layer over distances as far as 70 km in background air, and 30 km in the weakly advected urban plume. Vertical variations in trace gas concentrations were often minimal in the well-mixed PBL, and measurements at the surface always agreed well with aircraft observations up to 460 m above ground level. Under conditions of rapidly varying surface concentrations (e.g., during episodes of power plant plume fumigation and early morning boundary layer development), agreement between surface and aloft is dependent upon the spatial (aircraft) and temporal (ground) averaging intervals used in the comparison. Under these conditions, surface sites may be representative of the PBL only to within a few kilometers. Under clear skies in the well-mixed PBL, regression of aircraft trace gas data collected within 5 km of the ground sites against 15-20 min average surface concentrations centered on the times of the overflights yielded the following relationships: [O-3](aircraft) = ([O-3](surface) x 0.9374) + 4.86 ppbv (r(2)=0.9642); [CO](aircraft) = ([CO](surface) x 0.8914) + 16.4 ppbv (r(2)=0.9673); [SO2](aircraft) = ([SO2](surface) x 0.9414) - 0.069 ppbv (r(2)=0.9945). Although O-3, CO, and SO2 measurements at the surface and aloft generally agreed well, isolated examples of unexplained measurement discrepancies emerged, illustrating the need for side-by-side instrument comparisons. NOY measurements agreed poorly between surface and aircraft: [NOY](aircraft) = ([NOY](surface) X 0.9184) + 4.56 ppbv (r(2) = 0.9188). C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. NOAA, Air Resources Lab, Field Res Div, Idaho Falls, ID 83402 USA. Environm Res Ctr, Tennessee Valley Author, Muscle Shoals, AL 35662 USA. NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. NOAA, Air Resources Lab, Surface Radiat Res Branch, Boulder, CO 80303 USA. RP Luke, WT (reprint author), NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. EM winston.luke@noaa.gov RI Luke, Winston/D-1594-2016 OI Luke, Winston/0000-0002-1993-2241 NR 15 TC 10 Z9 10 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 SEP 20 PY 1998 VL 103 IS D17 BP 22317 EP 22337 DI 10.1029/98JD01247 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400028 ER PT J AU Parrish, DD Trainer, M Young, V Goldan, PD Kuster, WC Jobson, BT Fehsenfeld, FC Lonneman, WA Zika, RD Farmer, CT Riemer, DD Rodgers, MO AF Parrish, DD Trainer, M Young, V Goldan, PD Kuster, WC Jobson, BT Fehsenfeld, FC Lonneman, WA Zika, RD Farmer, CT Riemer, DD Rodgers, MO TI Internal consistency tests for evaluation of measurements of anthropogenic hydrocarbons in the troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; NONMETHANE HYDROCARBONS; SOURCE-RECONCILIATION; ORGANIC-COMPOUNDS; SEASONAL TRENDS; AIR MASSES; NITROGEN; PHOTOCHEMISTRY; EMISSIONS; ATLANTA AB Measurements of tropospheric nonmethane hydrocarbons (NMHCs) made in continental North America should exhibit a common pattern determined by photochemical removal and dilution acting upon the typical North American urban emissions. We analyze I I data sets collected in the United States in the context of this hypothesis, in most cases by analyzing the geometric mean and standard deviations of ratios of selected NMHCs. in the analysis we attribute deviations from the common pattern to plausible systematic and random experimental errors, in some cases the errors have been independently verified and the specific causes identified. Thus this common pattern provides a check for internal consistency in NMHC data sets. Specific tests are presented which should provide useful diagnostics for all data sets of anthropogenic NMHC measurements collected in the United States. Similar tests, based upon the perhaps different emission patterns of other regions, presumably could be developed. The specific tests include(1) a lower limit for ethane concentrations, (2) specific NMHCs that should be detected if any are, (3) the relatively constant mean ratios of the longer-lived NMHCs with similar atmospheric lifetimes, (4) the constant relative patterns of families of NMHCs, and (5) limits on the ambient variability of the NMHC ratios. Many experimental problems are identified in the literature and the Southern Oxidant Study data sets. The most important conclusion of this paper is that a rigorous field intercomparison of simultaneous measurement ambient NMHCs by different techniques and researchers is of crucial importance to the field of atmospheric chemistry. The tests presented here are suggestive of errors but are not definitive; only a field intercomparison can resolve the uncertainties. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Ohio Univ, Dept Chem Engn, Athens, OH 45701 USA. NOAA, Cooperat Inst Res Environm Sci, Boulder, CO USA. Univ Colorado, Boulder, CO 80309 USA. US EPA, Natl Environm Res Lab, Sr Environm Employment Program, Res Triangle Pk, NC 27711 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RP Parrish, DD (reprint author), NOAA, Aeron Lab, R-E-AL7,325 Broadway, Boulder, CO 80303 USA. EM parrish@al.noaa.gov RI Kuster, William/E-7421-2010; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; OI Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; Jobson, Bertram/0000-0003-1812-9745 NR 46 TC 65 Z9 66 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 SEP 20 PY 1998 VL 103 IS D17 BP 22339 EP 22359 DI 10.1029/98JD01364 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400029 ER PT J AU Lee, YN Zhou, X Kleinman, LI Nunnermacker, LJ Springston, SR Daum, PH Newman, L Keigley, WG Holdren, MW Spicer, CW Young, V Fu, B Parrish, DD Holloway, J Williams, J Roberts, JM Ryerson, TB Fehsenfeld, FC AF Lee, YN Zhou, X Kleinman, LI Nunnermacker, LJ Springston, SR Daum, PH Newman, L Keigley, WG Holdren, MW Spicer, CW Young, V Fu, B Parrish, DD Holloway, J Williams, J Roberts, JM Ryerson, TB Fehsenfeld, FC TI Atmospheric chemistry and distribution of formaldehyde and several multioxygenated carbonyl compounds during the 1995 Nashville Middle Tennessee Ozone Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; BIOGENIC HYDROCARBONS; ISOPRENE; PHOTOOXIDATION; PHOTOCHEMISTRY; MECHANISM; EMISSIONS; PAN AB Airborne measurements of formaldehyde (FA), glycolaldehyde (GA), glyoxal (GL), methylglyoxal (MG), and pyruvic acid (PD) were made on board instrumented aircraft platforms, the Department of Energy G1 and National Oceanic and Atmospheric Administration P3 (FA only), during the 1995 Nashville/Middle Tennessee Ozone Study. FA data determined on these two aircraft during three intercomparison flights agreed to within similar to 10%. The mean and median (in parentheses) concentrations observed within the boundary layer (< 2000 m) for FA, GA, GL, MG, and PD were 4.2 (3.9), 0.78 (0.70), 0.07 (0.06), 0.14 (0.10), and 0.24 (0.23), respectively (all in parts per billion by volume (ppbv)). At the observed concentrations, FA accounted for a substantial fraction of the OH reactivity, comparable to isoprene and CO. Further, it served as an important free radical precursor, contributing 25-30% of the radical production during midday and even greater during morning and late afternoon periods. Source attribution of FA was assessed using measured concentrations of hydrocarbons, their reaction kinetics with the OH radicals, and FA yields. The results showed that isoprene was the dominant source of FA, responsible for similar to 67%, methane and peroxyacetyl nitrate contributed equally at similar to 13% each, and alkanes and alkenes which are largely of anthropogenic origin accounted for only similar to 7%. This assessment based on reaction kinetics is consistent with the strong correlations (r > 0.8) observed between FA and two other isoprene products, GA and MG. Further, the magnitudes of the nonzero FA intercept exhibited in these correlation plots are found to qualitatively agree with the fraction of precursors that did not concomitantly produce GA and MG. Inspection of specific flights showed direct evidence of the dominance of isoprene as a precursor for FA, appreciable contribution of FA to CO, and negligible decay of FA overnight. Because of the dominant role isoprene plays as a precursor of FA, FA could be used as a proxy of isoprene for assessing the applicability of various versions of biogenic emission inventory. C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. Battelle Mem Inst, Atmospher Sci & Appl Technol, Columbus, OH 43201 USA. York Univ, Dept Chem, N York, ON M3J 1P3, Canada. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Lee, YN (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. EM ynlee@bnl.gov RI Roberts, James/A-1082-2009; Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013 OI Roberts, James/0000-0002-8485-8172; Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; NR 28 TC 115 Z9 115 U1 1 U2 23 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 SEP 20 PY 1998 VL 103 IS D17 BP 22449 EP 22462 DI 10.1029/98JD01251 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400037 ER PT J AU Roberts, JM Williams, J Baumann, K Buhr, MP Goldan, PD Holloway, J Hubler, G Kuster, WC McKeen, SA Ryerson, TB Trainer, M Williams, EJ Fehsenfeld, FC Bertman, SB Nouaime, G Seaver, C Grodzinsky, G Rodgers, M Young, VL AF Roberts, JM Williams, J Baumann, K Buhr, MP Goldan, PD Holloway, J Hubler, G Kuster, WC McKeen, SA Ryerson, TB Trainer, M Williams, EJ Fehsenfeld, FC Bertman, SB Nouaime, G Seaver, C Grodzinsky, G Rodgers, M Young, VL TI Measurements of PAN, PPN, and MPAN made during the 1994 and 1995 Nashville Intensives of the Southern Oxidant Study: Implications for regional ozone production from biogenic hydrocarbons SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID METHYL VINYL KETONE; GAS-PHASE REACTION; ORGANIC NITRATES; UNITED-STATES; PEROXYACETYL NITRATE; OXIDATION-PRODUCTS; ISOPRENE; METHACROLEIN; NOX; TROPOSPHERE AB Isoprene and a variety of other reactive hydrocarbons are released in large quantities by vegetation in forested regions and are thought to participate in the NOx-catalyzed production of ozone, a serious air quality problem in North America and Europe [National Research Council, 1991]. The determination of the fraction of O-3 formed from anthropogenic NOx and biogenic hydrocarbons (BHC) is a crucial step in the formulation of effective control strategies. Peroxymethacrylic nitric anhydride (MPAN, CH2C(CH3)C(O)OONO2) is formed almost entirely from the atmospheric oxidation of isoprene in the presence of NOx and is an excellent indicator of recent ozone production from isoprene and therefore biogenic hydrocarbons. Measurements are presented here of MPAN, peroxyacetic nitric anhydride (PAN, CH3C(O)OONO2), peroxypropionic nitric anhydride (PPN, CH3CH2C(O)OONO2) and ozone from separate data sets acquired during the 1994 and 1995 Nashville intensive studies of the Southern Oxidant Study. It was found that PAN, a general product of HC-NOx photochemistry, could be well represented as a simple linear combination of contributions from BHC and anthropogenic hydrocarbon (AHC) chemistries as indicated by MPAN and PPN, respectively. The PAN:MPAN ratios found to be characteristic of BHC-dominated chemistry ranged from 6 to 10. The PAN:PPN ratios found to be characteristic of AHC-dominated chemistry ranged from 5.8 to 7.4. These BHC and AHC attributions were used to estimate the contributions of anthropogenic and biogenic hydrocarbons to regional tropospheric ozone production, and substantial BKC-O-3 (50-60 ppbv) was estimated in cases where high NOx from power plants was present in areas of high BHC emission. This estimation method provides direct evidence of significant photochemical ozone production from the oxidation of biogenic hydrocarbons in the presence of NOx. C1 NOAA, Environm Res Labs, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Western Michigan Univ, Dept Chem, Kalamazoo, MI 49001 USA. Georgia Inst Technol, Dept Earth & Atmospher Sci, Atlanta, GA 30332 USA. York Univ, Ctr Atmospher Chem, N York, ON M3J 1P3, Canada. York Univ, Dept Chem, N York, ON M3J 1P3, Canada. RP Roberts, JM (reprint author), NOAA, Environm Res Labs, Aeron Lab, R-E-AL7,325 Broadway, Boulder, CO 80303 USA. RI Roberts, James/A-1082-2009; Williams, Eric/F-1184-2010; Kuster, William/E-7421-2010; Hubler, Gerhard/E-9780-2010; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; McKeen, Stuart/H-9516-2013; Fehsenfeld, Frederick/I-4876-2013 OI Roberts, James/0000-0002-8485-8172; Kuster, William/0000-0002-8788-8588; Holloway, John/0000-0002-4585-9594; NR 49 TC 72 Z9 75 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1998 VL 103 IS D17 BP 22473 EP 22490 DI 10.1029/98JD01637 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400039 ER PT J AU Frost, GJ Trainer, M Allwine, G Buhr, MP Calvert, JG Cantrell, CA Fehsenfeld, FC Goldan, PD Herwehe, J Hubler, G Kuster, WC Martin, R McMillen, RT Montzka, SA Norton, RB Parrish, DD Ridley, BA Shetter, RE Walega, JG Watkins, BA Westberg, HH Williams, EJ AF Frost, GJ Trainer, M Allwine, G Buhr, MP Calvert, JG Cantrell, CA Fehsenfeld, FC Goldan, PD Herwehe, J Hubler, G Kuster, WC Martin, R McMillen, RT Montzka, SA Norton, RB Parrish, DD Ridley, BA Shetter, RE Walega, JG Watkins, BA Westberg, HH Williams, EJ TI Photochemical ozone production in the rural southeastern United States during the 1990 Rural Oxidants in the Southern Environment (ROSE) program SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TEMPERATURE-DEPENDENT KINETICS; IONIZATION MASS-SPECTROMETRY; PHOTOLYSIS RATE COEFFICIENT; METHYL VINYL KETONE; PHOTOSTATIONARY STATE; PEROXY-RADICALS; RADIOMETER MEASUREMENTS; NATURAL HYDROCARBONS; CHEMICAL MECHANISM; BOUNDARY-LAYER AB Extensive measurements of ozone and its photochemical precursors and coproducts were made in the 1990 Rural Oxidants in the Southern Environment (ROSE) program. Peroxy radical production, loss, and partitioning are described at a rural site in Alabama, showing the important role that biogenic organic compounds play in ozone production. Estimates of the peroxy radical concentration obtained by four methods along with the measured nitric oxide level are used to predict the instantaneous rate of photochemical ozone production at the site. The four methods agree on the diurnal behavior of peroxy radicals and ozone production rates, while consistent discrepancies between the methods generally are within their combined uncertainties. Selected aircraft measurements are used to derive ozone production rates above the ground site, with the highest rates occurring in the boundary layer and in industrial plumes. The dependences of peroxy radical concentration and ozone production rate on the level of nitrogen oxides exhibit good agreement between the various methods and are consistent throughout the lower troposphere. Surface deposition and entrainment are shown to be as important as photochemical production in determining the diurnal evolution of ozone at this site. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Washington State Univ, Chem Engn Lab Atmospher Res, Pullman, WA 99164 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NOAA, Air Resources Lab, Oak Ridge, TN 37831 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Frost, GJ (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM gfrost@al.noaa.gov RI Williams, Eric/F-1184-2010; Kuster, William/E-7421-2010; Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Frost, Gregory/I-1958-2013; Fehsenfeld, Frederick/I-4876-2013; OI Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; Montzka, Stephen/0000-0002-9396-0400 NR 62 TC 62 Z9 64 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1998 VL 103 IS D17 BP 22491 EP 22508 DI 10.1029/98JD00881 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400040 ER PT J AU Banta, RM Senff, CJ White, AB Trainer, M McNider, RT Valente, RJ Mayor, SD Alvarez, RJ Hardesty, RM Parrish, D Fehsenfeld, FC AF Banta, RM Senff, CJ White, AB Trainer, M McNider, RT Valente, RJ Mayor, SD Alvarez, RJ Hardesty, RM Parrish, D Fehsenfeld, FC TI Daytime buildup and nighttime transport of urban ozone in the boundary layer during a stagnation episode SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WIND-STRUCTURE; UNITED-STATES; OSCILLATIONS; DISPERSION AB A 3-day period of strong, synoptic-scare stagnation, in which daytime boundary-layer winds were light and variable over the region, occurred in mid July of the 1995 Southern Oxidants Study centered on Nashville, Tennessee. Profiler winds showed light and variable flow throughout the mixed layer during the daytime, but at night in the layer between 100 and 2000 m AGL (which had been occupied by the daytime mixed layer) the winds accelerated to 5-10 m s(-1) as a result of nocturnal decoupling from surface friction, which produced inertial oscillations. In the present study, we investigate the effects of these wind changes on the buildup and transport of ozone (O-3) The primary measurement system used in this study was an airborne differential absorption lidar (DIAL) system that profiled O-3 in the boundary layer as the airplane flew along. Vertical cross sections showed that O-3 concentrations exceeding 120 ppb extended up to nearly 2 km AGL, but that the O-3 hardly moved at all horizontally, instead forming a dome of pollution over or near the city. The analysis concentrates on four meteorological processes that determine the 3-D spatial distribution of O-3 and the interaction between urban and rural pollution: (1) daytime buildup of O-3 over the urban area, (2) the extent of the drift of pollution cloud during the day as it formed, which controls peak O-3 concentrations, (3) nighttime transport by the accelerated winds above the surface, and (4) vertical mixing of pollution layers the next day. Other consequences of very light-wind conditions were intra-regional differences in daytime mixed-layer depth over distances of 50 km or less, and indications of an urban heat-island circulation. C1 NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. NOAA, ERL, Aeron Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Alabama, Huntsville, AL 35899 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Tennessee Valley Author, Muscle Shoals, AL 35662 USA. RP Alvarez, RJ (reprint author), NOAA, ERL, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. EM rbanta@etl.noaa.gov RI White, Allen/A-7946-2009; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Hardesty, Robert/H-9844-2013; Senff, Christoph/I-2592-2013; Alvarez, Raul/I-4879-2013; Fehsenfeld, Frederick/I-4876-2013; Banta, Robert/B-8361-2008 OI Parrish, David/0000-0001-6312-2724; NR 20 TC 89 Z9 93 U1 2 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 SEP 20 PY 1998 VL 103 IS D17 BP 22519 EP 22544 DI 10.1029/98JD01020 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400042 ER PT J AU Valente, RJ Imhoff, RE Tanner, RL Meagher, JF Daum, PH Hardesty, RM Banta, RM Alvarez, RJ McNider, RT Gillani, NV AF Valente, RJ Imhoff, RE Tanner, RL Meagher, JF Daum, PH Hardesty, RM Banta, RM Alvarez, RJ McNider, RT Gillani, NV TI Ozone production during an urban air stagnation episode over Nashville, Tennessee SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; RURAL SITE; DEPOSITION; ATLANTA AB The highest O-3 levels observed during the 1995 Southern Oxidants Study in middle Tennessee occurred during a period of air stagnation from July 11 through July 15. Extensive airborne (two fixed wing and one helicopter) and ground-based measurements of the chemistry and meteorology of this episode near Nashville, Tennessee, are presented. In situ airborne measurements include O-3, NOy, NO, NO2, SO2, CO, nitrate, hydrocarbons, and aldehydes. Airborne LIDAR O-3 measurements are also utilized to map the vertical and horizontal extent of the urban plume. The use of multiple instrumented research aircraft permitted highly detailed mapping of the plume chemistry in the vertical and horizontal dimensions. Interactions between the urban Nashville plume (primarily a NOx and hydrocarbon source) and the Gallatin coal-fired power plant plume (primarily a NOx and SO2 source) are also documented, and comparisons of ozone formation in the isolated and mixed urban and power plant plume are presented. The data suggest that during this episode the background air and the edges of the urban plume are NOx sensitive and the core of the urban plume is hydrocarbon sensitive. Under these worst case meteorological conditions, ambient O-3 levels well over the level of the new National Ambient Air Quality Standard (NAAQS) for ozone (80 ppb) were observed over and just downwind of Nashville. For example, on July 12, the boundary layer air upwind of Nashville showed 60 to 70 ppb O-3, while just downwind of the city the urban plume maximum was over 140 ppb O-3. With a revised ozone standard set at 80 ppb (8 hour average) and upwind levels already within 10 or 20 ppb of the standard, only a slight increase in ozone from the urban area will cause difficulty in attaining the standard at monitors near the care of the urban plume during this type of episode. The helicopter mapping and LIDAR aircraft data clearly illustrate that high O-3 levels can occur during stagnation episodes within a few kilometers of and even within the urban area. The extremely light boundary layer winds (1-3 m s(-1)) contributed to the creation of an ozone dome or blob which stayed very near to the city rather than an elongated plume. The small spatial scale of the zone of high O-3 concentrations is mapped in detail demonstrating that the regulatory monitoring network failed to document the maximum O-3 concentrations. Modelers using such regulatory data to test photochemical algorithms need to bear in mind that magnitude and frequency of urban ozone may be underestimated by monitoring networks, especially in medium-sized urban areas under slow transport conditions. Finally, this effort shows the value of collaborative field measurements from multiple platforms in developing a more complete picture of the chemistry and transport of photochemical O-3. C1 Tennessee Valley Author, Atmospher Sci & Environm Assessments, Muscle Shoals, AL 35662 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ Alabama, Earth Syst Sci Lab, Huntsville, AL 35899 USA. Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. RP Valente, RJ (reprint author), Tennessee Valley Author, Atmospher Sci & Environm Assessments, CEB2A,POB 1010, Muscle Shoals, AL 35662 USA. EM rjvalente@tva.gov RI Hardesty, Robert/H-9844-2013; Alvarez, Raul/I-4879-2013; Banta, Robert/B-8361-2008 NR 19 TC 27 Z9 27 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1998 VL 103 IS D17 BP 22555 EP 22568 DI 10.1029/98JD01641 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400044 ER PT J AU Ryerson, TB Buhr, MP Frost, GJ Goldan, PD Holloway, JS Hubler, G Jobson, BT Kuster, WC McKeen, SA Parrish, DD Roberts, JM Sueper, DT Trainer, M Williams, J Fehsenfeld, FC AF Ryerson, TB Buhr, MP Frost, GJ Goldan, PD Holloway, JS Hubler, G Jobson, BT Kuster, WC McKeen, SA Parrish, DD Roberts, JM Sueper, DT Trainer, M Williams, J Fehsenfeld, FC TI Emissions lifetimes and ozone formation in power plant plumes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFUR INTERCOMPARISON EXPERIMENT; SOUTHEASTERN UNITED-STATES; HIGH-SENSITIVITY; BOUNDARY-LAYER; NORTH-ATLANTIC; URBAN PLUME; RURAL OZONE; NOY; TROPOSPHERE; POLLUTANTS AB The concept of ozone production efficiency (OPE) per unit NOx is based on photochemical models and provides a tool with which to assess potential regional tropospheric ozone control strategies involving NOx emissions reductions. An aircraft study provided data from which power plant emissions removal rates and measurement-based estimates of OPE are estimated. This study was performed as part of the Southern Oxidants Study-1995 Nashville intensive and focuses on the evolution of NOx, SO2, and ozone concentrations in power plant plumes during transport. Two approaches are examined. A mass balance approach accounts for mixing effects within the boundary layer and is used to calculate effective boundary layer removal rates for NOx and SO2 and to estimate net OPE. Net OPE is more directly comparable to photochemical model results than previous measurement-based estimates. Derived net production efficiencies from mass balance range from 1 to 3 molecules of ozone produced per molecule of NOx emitted. A concentration ratio approach provides an estimate of removal rates of primary emissions relative to a tracer species. This approach can be combined with emissions ratio information to provide upper limit estimates of OPE that range from 2 to 7. Both approaches illustrate the dependence of ozone production on NOx source strength in these large point source plumes. The dependence of total ozone production, ozone production efficiency, and the rate of ozone production on NOx source strength is examined. These results are interpreted in light of potential ozone control strategies for the region. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ryerson, TB (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM tryerson@al.noaa.gov RI Roberts, James/A-1082-2009; Kuster, William/E-7421-2010; Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; McKeen, Stuart/H-9516-2013; Frost, Gregory/I-1958-2013; Fehsenfeld, Frederick/I-4876-2013; OI Roberts, James/0000-0002-8485-8172; Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; Jobson, Bertram/0000-0003-1812-9745 NR 41 TC 130 Z9 132 U1 2 U2 31 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 SEP 20 PY 1998 VL 103 IS D17 BP 22569 EP 22583 DI 10.1029/98JD01620 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400045 ER PT J AU Jobson, BT Frost, GJ McKeen, SA Ryerson, TB Buhr, MP Parrish, DD Trainer, M Fehsenfeld, FC AF Jobson, BT Frost, GJ McKeen, SA Ryerson, TB Buhr, MP Parrish, DD Trainer, M Fehsenfeld, FC TI Hydrogen peroxide dry deposition lifetime determined from observed loss rates in a power plant plume SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; GAS-PHASE PEROXIDES; HYDROXYMETHYL HYDROPEROXIDE; UNITED-STATES; PEROXYACETIC ACID; CHEMISTRY; TROPOSPHERE; OZONE; PARAMETERIZATION; PHOTOCHEMISTRY AB Hydrogen peroxide measurements made aboard the NOAA WP-3D aircraft in the summer of 1995 as part of the Southern Oxidants Study revealed loss of hydrogen peroxide within fossil fuel power plant plumes and the Nashville urban plume. On July 7 the Cumberland power plant plume was intercepted at five different downwind distances. H2O2 mixing ratios,within the plume decreased with increasing distance from the plant. Conversely, ozone mixing ratios increased. The H2O2 loss was likely a result of the lowered rate of formation due to suppression of HO2 radical concentrations in the high NOx environment and subsequent removal of H2O2 by photolysis, reaction with HO, and dry deposition. From steady state model estimates of the chemical loss rates in the plume and an analytical approximation of the influx of H2O2 into the plume center due to horizontal dispersion, a simple budget for H2O2 was formulated, from which a dry deposition lifetime of 19 hours +/- 55% was inferred. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Jobson, BT (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. EM tjobson@al.noaa.gov RI Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; McKeen, Stuart/H-9516-2013; Frost, Gregory/I-1958-2013; Fehsenfeld, Frederick/I-4876-2013; OI Parrish, David/0000-0001-6312-2724; Jobson, Bertram/0000-0003-1812-9745 NR 45 TC 11 Z9 11 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 SEP 20 PY 1998 VL 103 IS D17 BP 22617 EP 22628 DI 10.1029/98JD01619 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400048 ER PT J AU Meyers, TP Finkelstein, P Clarke, J Ellestad, TG Sims, PF AF Meyers, TP Finkelstein, P Clarke, J Ellestad, TG Sims, PF TI A multilayer model for inferring dry deposition using standard meteorological measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BOUNDARY-LAYER RESISTANCES; OZONE DEPOSITION; SULFUR-DIOXIDE; TRANSFER-COEFFICIENTS; STOMATAL CONDUCTANCE; DECIDUOUS FOREST; NITRIC-ACID; CANOPY; FLUCTUATIONS; VELOCITIES AB rn this paper, we describe the latest version of the dry deposition inferential model, which is used to estimate the deposition velocities (V-d) for SO2, O-3, HNO3, and particles with diameters less than 2 mu m. The dry deposition networks operated by the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA) use this model to estimate dry deposition on a weekly basis. This model uses a multilayer approach, discretizing the vegetated canopy into 20 layers. The use of canopy radiative transfer and simple wind profile models allows for estimates of stomatal (r(s)) and leaf boundary layer (r(b)) resistances to be determined at each layer in the plant canopy for both sunlit and shaded leaves. The effect of temperature, water stress, and vapor pressure deficits on the stomatal resistance (r(s)) have been included. Comparisons of modeled deposition velocities are made with extensive direct measurements performed at three different locations with different crops. The field experiment is discussed in some detail. Overall, modeled O-3 deposition velocities are in good agreement with measured values with the average mean bias for all surfaces of the order of 0.01 cm/s or less. For SO2, mean biases range from -0.05 for corn to 0.15 cm/s for soybeans, while for HNO3, they range from 0.09 for corn to 0.47 cm/s for pasture. C1 NOAA, ERL, Air Resources Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. NOAA, ERL, Air Resources Lab, Atmospher Modelling Div, Res Triangle Pk, NC 27711 USA. US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. RP Meyers, TP (reprint author), NOAA, ERL, Air Resources Lab, Atmospher Turbulence & Diffus Div, POB 2456, Oak Ridge, TN 37831 USA. EM meyers@atdd.noaa.gov RI Meyers, Tilden/C-6633-2016 NR 53 TC 134 Z9 139 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1998 VL 103 IS D17 BP 22645 EP 22661 DI 10.1029/98JD01564 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120WM UT WOS:000075980400050 ER PT J AU Tsu, IF Wang, JL Kaiser, DL Babcock, SE AF Tsu, IF Wang, JL Kaiser, DL Babcock, SE TI A comparison of grain boundary topography and dislocation network structure in bulk-scale [001] tilt bicrystals of Bi2Sr2CaCu2O8+x and YBa2Cu3O7-delta SO PHYSICA C LA English DT Article DE bicrystals; grain boundaries; YBa2Cu3O7-delta; Bi2Sr2Ca1Cu2O8+x; facets; dislocations ID CRITICAL-CURRENT-DENSITY; THIN-FILMS; ATOMIC-STRUCTURE; SINGLE-CRYSTALS; SUPERCONDUCTORS; JUNCTIONS; SYMMETRY; GROWTH; PLANE; TAPES AB The facet topography and grain boundary dislocation content of the grain boundaries in nominally [001] tilt bicrystals of Bi2Sr2Ca1Cu2O8+x (2212) and YBa2Cu3O7-delta (YBCO) are described and compared. Bicrystals with misorientation angles ranging from 8 degrees to 15 degrees were studied by polarized light microscopy, diffraction-contrast transmission electron microscopy (TEM) and high-resolution TEM. On the micron length scale of light microscopy, all of the boundaries appeared to be of pure tilt character and to form facets with dimensions on the order of fifty and several hundred micrometers in YBCO and 2212, respectively. However, TEM studies revealed a distinctly different characteristic pattern of faceting on the 100 nm length scale. In 2212, a rather irregular arrangement of nominally pure symmetrical [001] tilt facets and [001] twist facets is suggested. Very regular saw-tooth shaped arrangements of just two types of tilt facets predominate in YBCO. The nanoscale topography and structure of the tilt boundary facets show similarities in the two materials. Boundaries in both materials tend to facet further onto symmetric tilt planes on the nanoscale. This preference is most pronounced in 2212. A single set of partial edge dislocations and their associated stacking faults comprises the grain boundary dislocation network structure of the symmetric segments in both materials. Thus, the boundaries show nanoscale similarities, mesoscale (similar to 100 nm) differences, and a number of different possible microstructural sources for the heterogeneous electrical character that is indicated by their electromagnetic properties. (C) 1998 Printed by Elsevier Science B.V. All rights reserved. C1 Univ Wisconsin, Mat Sci & Engn & Appl Superconduct Ctr, Madison, WI 53706 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Babcock, SE (reprint author), Univ Wisconsin, Mat Sci & Engn & Appl Superconduct Ctr, 1500 Engn Dr, Madison, WI 53706 USA. NR 52 TC 21 Z9 21 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 20 PY 1998 VL 306 IS 3-4 BP 163 EP 187 DI 10.1016/S0921-4534(98)00361-X PG 25 WC Physics, Applied SC Physics GA 129TP UT WOS:000076479300001 ER PT J AU Kallenborn, R Oehme, M Wynn-Williams, DD Schlabach, M Harris, J AF Kallenborn, R Oehme, M Wynn-Williams, DD Schlabach, M Harris, J TI Ambient air levels and atmospheric long-range transport of persistent organochlorines to Signy Island, Antarctica SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE organochlorines; global transport; ambient air concentrations; Antarctica ID PESTICIDES; POLLUTANTS; OCEAN AB Levels of persistent organic pollutants (POPs), such as polychlorinated biphenyls and pesticides have been determined in ambient air at Signy Island, Antarctica, over a period of 17 weeks. Mean concentrations for single polychlorinated biphenyls (0.02-17 pg/m(3)), for chlordanes (0.04-0.9 pg/m(3)), DDT compounds (0.07-0.40 pg/m(3)) and gamma-hexachlorocyclohexane (HCH, 22 pg/m(3)) were comparable to those in Arctic air. However, alpha-HCH levels were approximately one order of magnitude lower. Compared to the Arctic, differences were also observed in the concentration ratios of alpha-/gamma-HCH and chlordane compounds. Two possible atmospheric long-range transport episodes from South America were found by comparing 10-day back trajectories with observed concentration changes. The lower limits of determination (LOD) were mainly governed by the field blanks. They were satisfactory for the most volatile PCBs. However, many concentrations for DDT and chlordane compounds were below the LODs (range 0.1-1 pg/m(3)) or even the instrumental detection limit (0.01-0.03 pg/m(3)). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Norwegian Inst Air Res, N-9005 Tromso, Norway. Univ Basel, CH-4057 Basel, Switzerland. British Antarctic Survey, Cambridge CB3 0ET, England. NOAA, Dept Commerce, Boulder, CO 80303 USA. RP Kallenborn, R (reprint author), Norwegian Inst Air Res, N-9005 Tromso, Norway. RI Kallenborn, Roland/F-8368-2011; Schlabach, Martin/J-3348-2013 OI Kallenborn, Roland/0000-0003-1703-2538; Schlabach, Martin/0000-0003-3705-7943 NR 20 TC 94 Z9 102 U1 2 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD SEP 18 PY 1998 VL 220 IS 2-3 BP 167 EP 180 DI 10.1016/S0048-9697(98)00257-5 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA 130CN UT WOS:000076501700007 ER PT J AU Fahr, A Hassanzadeh, P Atkinson, DB AF Fahr, A Hassanzadeh, P Atkinson, DB TI Ultraviolet absorption spectrum and cross-sections of vinyl (C2H3) radical in the 225-238 nm region SO CHEMICAL PHYSICS LA English DT Article ID C3H3 RADICALS; DISPROPORTIONATION; 1,3-BUTADIENE; COMBINATION; ETHENYL; METHYL; ATOMS AB The room-temperature gas-phase ultraviolet absorption spectrum and cross-sections of vinyl (C2H3) radicals have been determined in the spectral range 225-238 nm, employing cavity ring-down absorption spectroscopy. Vinyl radicals in these experiments were produced from the 193 nm excimer laser photolysis of methyl vinyl ketone (CH3COC2H3) and vinyl bromide (C2H3Br). The spectra obtained from the two systems were nearly identical. The observed spectrum exhibits a relatively broad and featureless absorption with a cross-section of 5.3 x 10(-18) cm(2) molecule(-1) at 230 nm. A combined uncertainty of similar to 25% for cross-section values has been assessed. The electronic transitions in the vinyl radical have been calculated by ab initio quantum chemical methods at the CIS, EOM-CCSD, CASSCF and CASPT2 levels of theories which assign the new observed band to the highly allowed and 'in plane' pi*(2a ") <-- pi(1a ") transition. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Fahr, A (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 27 TC 44 Z9 46 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD SEP 15 PY 1998 VL 236 IS 1-3 BP 43 EP 51 DI 10.1016/S0301-0104(98)00213-4 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 120AT UT WOS:000075932400005 ER PT J AU Andrews, AM Fraser, GT Pate, BH AF Andrews, AM Fraser, GT Pate, BH TI Molecular-beam infrared-infrared double-resonance spectroscopy study of the vibrational dynamics of the acetylenic C-H stretch of propargyl amine SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EXTENSIVELY PERTURBED SPECTRA; ENERGY REDISTRIBUTION; TUNNELING SPLITTINGS; DIRECT DECONVOLUTION; ROTATIONAL SPECTRUM; EIGENSTATE SPECTRUM; HYDROGEN-ATOM; RELAXATION; BAND; FLUORESCENCE AB The acetylenic C-H stretch spectrum of propargyl amine near 3330 cm(-1) has been measured at 0.0002 cm(-1) (6 MHz) resolution with a tunable color-center laser in an electric-resonance optothermal spectrometer. The spectrum has been fully assigned through IR-IR double resonance measurements employing a tunable, microwave sideband-CO2 laser. The 10 mu m spectrum of propargyl amine displays splittings in the two nuclear spin symmetry states arising from amino-proton interchange, allowing double-resonance assignment of the -NH2 group resultant proton nuclear spin quantum number in the highly fragmented 3 mu m spectrum. The experimental state density is consistent with a (2J + 1) increase that is expected if all near-resonant states are coupled. From this J-dependent growth in the state density we determine the density of states at J = 0 to be 22 states/cm(-1). This value is in reasonable agreement with the direct state count result of 16 states/cm(-1). The unperturbed transition frequencies for the two different nuclear spin species at a given rotational level do not coincide, differing on average by about 50 MHz. The nonresonant coupling effects which produce effective splittings in the 10 mu m spectrum appear to survive into the high state density regime. The measured IVR lifetimes are on the order of 500 ps for the low K-a values studied here (K-a < 4) and show a K-a-dependence with the IVR rate increasing as K-a increases. The statistical properties of the spectrum have been compared to predictions from random matrix theory. The level spacings are not well represented by Wigner statistics as would be expected for underlying chaotic classical dynamics. However, the intensity fluctuations are consistent with a chi(2)-distribution, expected for classically chaotic systems, as measured by Heller's F-statistic. (C) 1998 American Institute of Physics. C1 NIST, Div Mol Phys, Gaithersburg, MD 20899 USA. RP Andrews, AM (reprint author), Inst Def Anal, 1801 N Beauregard, Alexandria, VA 22311 USA. NR 49 TC 15 Z9 15 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1998 VL 109 IS 11 BP 4290 EP 4301 DI 10.1063/1.477033 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 118LF UT WOS:000075839100018 ER PT J AU Wiegand, S Berg, RF Sengers, JMHL AF Wiegand, S Berg, RF Sengers, JMHL TI Critical viscosity of the ionic mixture triethyl n-hexyl ammonium triethyl n-hexyl borate in diphenyl ether SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SYSTEM 2-BUTOXYETHANOL WATER; DYNAMIC LIGHT-SCATTERING; CRITICAL CONSOLUTE POINT; BINARY-LIQUID MIXTURE; CRITICAL EXPONENT; TETRAALKYLAMMONIUM-TETRAALKYLBORIDES; ETHYLAMMONIUM NITRATE; COEXISTENCE CURVE; CRITICAL-BEHAVIOR; SHEAR VISCOSITY AB We report measurements of the viscosity near the consolute point of triethyl n-hexyl ammonium triethyl n-hexyl borate in diphenyl ether. Until recently, this ionic mixture was the leading candidate for a ''mean-field'' ionic fluid composed of small molecules. The measurements of the coexistence curve of Singh and Fitter and the measurements of turbidity of Zhang et al. had indicated mean-field static behavior. In contrast, the present measurements show a critical viscosity enhancement similar to that seen in Ising fluids. Such an enhancement is not expected in either a mean-field fluid or a fluid with sufficiently long-ranged forces. The measurements were made in two very different viscometers. Both viscometers achieved low shear rates by use of a flow impedance larger than in a conventional capillary viscometer. The first viscometer's impedance was a glass frit consisting of about 10(5) pores of 5.5 mu m diam each. The second viscometer's impedance was a single I m long, 203 mu m diam capillary. In both viscometers, the sample was sealed entirely in glass, in order to inhibit decomposition of the sample. (C) 1998 American Institute of Physics. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Wiegand, S (reprint author), Univ Bremen, Inst Anorgan & Phys Chem, Leobener Str, D-28334 Bremen, Germany. EM robert.berg@nist.gov RI Wiegand, Simone/G-6257-2013 OI Wiegand, Simone/0000-0001-6333-1956 NR 53 TC 33 Z9 33 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1998 VL 109 IS 11 BP 4533 EP 4545 DI 10.1063/1.477057 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 118LF UT WOS:000075839100044 ER PT J AU Overland, JE McNutt, SL Salo, S Groves, J Li, SS AF Overland, JE McNutt, SL Salo, S Groves, J Li, SS TI Arctic sea ice as a granular plastic SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID BEAUFORT-SEA; PACK ICE; MODEL; DYNAMICS; FLOW AB An important consideration in understanding sea ice mechanics is the integration of observed sea ice behavior on a flee neighborhood scale (1-10 km) into ice dynamics on a regional scale O(50 km). We investigate sea ice kinematics from October 1993 through April 1994 using relative motions from 13 drifting buoys with Global Positioning System navigation in a 20-km array centered on the Sea Ice Mechanics Initiative ice camp, and we compare these motions to synthetic aperture radar (SAR)derived ice velocities over a 100- by 500-km region in the Beaufort Sea. There is excellent correspondence between the deformation of the buoy array and that from the SAR. Inferred ice dynamics from analysis of the two major northerly wind convergence events of the winter are consistent with a granular hardening plastic conceptual model for Beaufort sea ice. Under continued northerly winds the ice from the Alaskan shore to the camp failed in shear and convergence, in a progressive manner away from the coast. The continuum scale O(10 km) is an order of magnitude larger than the grain, i.e., flee, size O(1 km). The ice motion often forms aggregates of 20-200 km separated by narrow (<10 km) shear zones, similar to granular materials. At moderate forcing, i.e., wind stress multiplied by fetch, the ice appears to fail along slip lines that occur at an acute angle to each other and to the direction of the wind forcing, characteristic of a plastic material at critical state. With longer fetch the ice appears to fail in compression, perpendicular to the wind direction. Sea ice appeared to harden on a regional scale after the first event. During the second northerly wind event there was a sea ice breakout toward the west, apparently due to a lack of lateral confining stress. Our observations suggest that the ice flees advect through relatively stationary stress fields, created by the wind forcing and coastal boundaries. For example, while the SAR and advanced very high resolution radiometer images indicated the presence of the shear feature at the same geographic location for nearly a week, buoys would show shearing only for several days as they transited across the region of shear. There is a high correspondence between the major internal ice deformation events and persistent weather patterns on a 3- to 5-day temporal scale. This implies that SAR data collection and analysis for regional sea ice dynamics should be consistent with the wind forcing and have a sampling of less than 3 days. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99701 USA. RP Overland, JE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 41 TC 36 Z9 41 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1998 VL 103 IS C10 BP 21845 EP 21867 DI 10.1029/98JC01263 PG 23 WC Oceanography SC Oceanography GA 118WG UT WOS:000075863500037 ER PT J AU Perez, E Cerrada, ML Vanderhart, DL AF Perez, E Cerrada, ML Vanderhart, DL TI Rapid determination of comonomer content, crystallinity and long spacing by multiple-pulse proton NMR in ethylene-vinyl alcohol copolymers SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE ethylene-vinyl alcohol copolymers; multiple-pulse proton NMR; spin diffusion; comonomer content; crystallinity; long spacing ID POLYMER BLENDS; SOLIDS; SPECTROSCOPY; H-1-NMR AB Capitalizing on the superior sensitivity of proton NMR, relatively rapid estimates of three parameters, namely, comonomer content, crystallinity, and long spacing, are determined for three ethylene/vinyl alcohol copolymers using solid-state proton NMR measurements. Multiple-pulse techniques are utilized (a) in conjunction with magic angle spinning for measuring comonomer content, (b) in conjunction with a T-1xz relaxation measurement for determining crystallinity, and (c) in conjunction with a T-1xz-based spin diffusion measurement for determining the long spacing. These three parameters, extracted from data collected in a total spectrometer time of about 20 min, are compared with similar parameters obtained using more conventional DSC, SAXS (including synchrotron), and solution-state NMR measurements. Agreement is found to be good. (C) 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2103-2109, 1998. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. CSIC, Inst Ciencia & Tecnol Polimeros, E-28006 Madrid, Spain. RP Vanderhart, DL (reprint author), Natl Inst Stand & Technol, Div Polymers, Bldg 224-A209, Gaithersburg, MD 20899 USA. RI CERRADA, MARIA/E-9810-2016; Perez, Ernesto/G-3254-2016 OI CERRADA, MARIA/0000-0003-4261-0627; Perez, Ernesto/0000-0002-5144-9268 NR 22 TC 8 Z9 8 U1 1 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 1998 VL 36 IS 12 BP 2103 EP 2109 PG 7 WC Polymer Science SC Polymer Science GA 106DQ UT WOS:000075114900009 ER PT J AU Ankudinov, AL Ravel, B Rehr, JJ Conradson, SD AF Ankudinov, AL Ravel, B Rehr, JJ Conradson, SD TI Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure SO PHYSICAL REVIEW B LA English DT Article ID FINE-STRUCTURE; ELECTRONIC-STRUCTURE; K-EDGES; SPECTRA; TEMPERATURE; CLUSTERS; LA2-XSRXCUO4; DIFFRACTION; TRANSITION; MOLECULES AB A self-consistent real-space multiple-scattering (RSMS) approach for calculations of x-ray-absorption near-edge structure (XANES) is presented and implemented in an ab initio code applicable to arbitrary aperiodic or periodic systems. This approach yields a quantitative interpretation of XANES based on simultaneous, self-consistent-field (SCF) calculations of local electronic structure and x-ray absorption spectra, which include full multiple scattering from atoms within a small cluster and the contributions of high-order MS from scatterers outside that cluster. In addition, the code includes a SCF estimate of the Fermi energy and an account of orbital occupancy and charge transfer. We also present a qualitative, scattering-theoretic interpretation of XANES. Sample applications are presented for cubic BN, UF6, Pu hydrates, and distorted PbTiO3. Limitations and various extensions are also discussed. [S0163-1829(98)03736-9]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Ankudinov, AL (reprint author), Univ Calif Los Alamos Natl Lab, MST-11, Los Alamos, NM 87545 USA. NR 53 TC 3123 Z9 3151 U1 31 U2 269 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 SEP 15 PY 1998 VL 58 IS 12 BP 7565 EP 7576 DI 10.1103/PhysRevB.58.7565 PG 12 WC Physics, Condensed Matter SC Physics GA 123ND UT WOS:000076130500023 ER PT J AU Brassard, G Chuang, I Lloyd, S Monroe, C AF Brassard, G Chuang, I Lloyd, S Monroe, C TI Quantum computing SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT 9th Annual Frontiers of Science Symposium CY NOV 07-09, 1997 CL IRVINE, CA SP Natl Acad Sci (NAS) C1 Univ Montreal, Dept Informat & Rech Operat, Montreal, PQ H3C 3J7, Canada. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. MIT, Dept Mech Engn, Cambridge, MA 02139 USA. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Univ Montreal, Dept Informat & Rech Operat, CP 6128,Succursale Centreville, Montreal, PQ H3C 3J7, Canada. RI Monroe, Christopher/G-8105-2011 NR 11 TC 10 Z9 10 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 15 PY 1998 VL 95 IS 19 BP 11032 EP 11033 DI 10.1073/pnas.95.19.11032 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 120LD UT WOS:000075957100004 PM 9736681 ER PT J AU Hamann, HF Gallagher, A Nesbitt, DJ AF Hamann, HF Gallagher, A Nesbitt, DJ TI Enhanced sensitivity near-field scanning optical microscopy at high spatial resolution SO APPLIED PHYSICS LETTERS LA English DT Article AB An apertureless near-field optical-imaging method is presented that achieves high spatial resolution as well as a similar to 4000-fold increase in detection sensitivity, by exploiting the highly localized enhanced near-field interactions between the sample (e.g., Au nanospheres) and a sharp atomic force microscope tip under evanescent laser field illumination. This represents a general method for optical imaging at less than or equal to 2 nm spatial resolution, and is applicable to both resonant (i.e., scattering) as well as nonresonant (i.e., fluorescence, Raman, etc.) spectroscopic methods. (C) 1998 American Institute of Physics. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Hamann, HF (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM djn@jila.colorado.edu NR 11 TC 74 Z9 74 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 14 PY 1998 VL 73 IS 11 BP 1469 EP 1471 DI 10.1063/1.122176 PG 3 WC Physics, Applied SC Physics GA 118VK UT WOS:000075861100005 ER PT J AU Hutchinson, DAW Dodd, RJ Burnett, K AF Hutchinson, DAW Dodd, RJ Burnett, K TI Gapless finite-T theory of collective modes of a trapped gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-GAS; EXCITATIONS AB We present predictions for the frequencies of collective modes of trapped Bose-condensed Rb-87 atoms at finite temperature. Our treatment includes a self-consistent treatment of the effects upon the mean field from finite-T excitations and the anomalous average. This is the first gapless [A. Griffin, Phys. Rev. B 53, 9341 (1996)] calculation of this type for a trapped Bose-Einstein condensed gas. The corrections quantitatively account for the downward shift in the m = 2 excitation frequencies observed in recent experiments as the critical temperature is approached. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Technol Adm, Div Electron & Opt Phys, Natl Inst Stand & Technol, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Hutchinson, DAW (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. NR 14 TC 88 Z9 88 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 SEP 14 PY 1998 VL 81 IS 11 BP 2198 EP 2200 DI 10.1103/PhysRevLett.81.2198 PG 3 WC Physics, Multidisciplinary SC Physics GA 119LH UT WOS:000075897300004 ER PT J AU Bondu, F Hello, P Vinet, JY AF Bondu, F Hello, P Vinet, JY TI Thermal noise in mirrors of interferometric gravitational wave antennas SO PHYSICS LETTERS A LA English DT Article ID DETECTORS AB We present a direct and very fast calculation of the low frequency tail of the spectral density of thermal noise due to the thermal motion of matter in the cylindrical mirrors generally used in gravitational wave interferometric detectors. This calculation is based on the method recently proposed by Levin, that we extend to the case of finite mirrors, allowing one to study the aspect ratio dependence of the noise. Results are found in good agreement with those found in heavier preceding approaches, and provide a useful cross-check. (C) 1998 Elsevier Science B.V. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Paris Sud, Accelerateur Lineaire Lab, F-91405 Orsay, France. Ecole Polytech, Ecole Natl Super Tech Avancees, Lab Opt Appl, F-91120 Palaiseau, France. RP Bondu, F (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Bondu, Francois/A-2071-2012 OI Bondu, Francois/0000-0001-6487-5197 NR 11 TC 73 Z9 73 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD SEP 14 PY 1998 VL 246 IS 3-4 BP 227 EP 236 DI 10.1016/S0375-9601(98)00450-2 PG 10 WC Physics, Multidisciplinary SC Physics GA 119DD UT WOS:000075879500004 ER PT J AU Garcia, HA AF Garcia, HA TI Reconstructing the thermal and spatial form of a solar flare from scaling laws and soft X-ray measurements SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : X-rays, gamma rays ID EMISSION MEASURE; CORONAL LOOPS; ELECTRON-TEMPERATURE; DYNAMICS; YOHKOH; PLASMA AB The thermal and spatial structure of individual solar flares can be modeled from full-disk soft X-ray measurements by invoking scaling laws that provide a theoretical relationship between certain thermal properties of the flare, its X-ray light curve, and its size and shape. The well-known scaling law, often called RTV after the authors Rosner, Tucker, & Vaiana, relates the hare loop length L, the maximum (loop-top) temperature T-m, and the internal pressure p. In the present analysis GOES soft X-ray data (two channels) are used to derive two diagnostic parameters, T-a and epsilon, which can then be used to compute T-m and p. T-a is the temperature obtained from the observed integrated X-ray flux; epsilon is the emission measure. The operation to compute T-m and p has a unique solution only when a representative value of the loop length, L, is available. Another scaling law by Hawley and coworkers and Metcalf & Fisher relates L to the flare rise and decay times, tau(r) and tau(d). This law, calibrated against measured loops from Yohkoh SXT imagery, can provide an initial estimate of the loop length. We demonstrate that the character of individual flares can be inferred from nonimaged, full-disk soft X-ray measurements in combination with scaling laws: the X-ray light curve is used to; estimate the length dimension from the rise and decay times, and discrete X-ray measurements are used to compute the macro thermal and spatial structure at any selected time during the decay. C1 NOAA, Space Environm Lab, Boulder, CO 80303 USA. RP NOAA, Space Environm Lab, 325 Broadway, Boulder, CO 80303 USA. EM hgarcia@sec.noaa.gov NR 21 TC 19 Z9 20 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1998 VL 504 IS 2 BP 1051 EP 1066 DI 10.1086/306101 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152KW UT WOS:000077777500041 ER PT J AU Roitberg, AE Holden, MJ Mayhew, MP Kurnikov, IV Beratan, DN Vilker, VL AF Roitberg, AE Holden, MJ Mayhew, MP Kurnikov, IV Beratan, DN Vilker, VL TI Binding and electron transfer between putidaredoxin and cytochrome P450cam. Theory and experiments SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; TRANSFER COMPLEX; TUNNELING PATHWAYS; MOLECULAR-DYNAMICS; CRYSTAL-STRUCTURE; C PEROXIDASE; PROTEIN; MODEL; ASSOCIATION; 5-MONOOXYGENASE AB We present a detailed atomic level view of the interactions between cytochrome P450cam (CYP101) and its natural redox partner, putidaredoxin (Pdx). A combined theoretical (Poisson-Boltzmann electrostatic calculations, electron transfer pathways, and molecular dynamics) and experimental (site-directed mutagenesis and kinetic analysis) study is used to pinpoint surface residues in both proteins that are important for electron transfer, binding, or both. We find a situation where the electrostatically complementary regions at the surface of both proteins overlap strongly with regions that have large electron transfer couplings to the redox centers. This means that a small surface patch in each protein is involved in binding and electron transfer. A dominant electron transfer pathway is identified, corresponding to an electron leaving the reduced Fe2S2 in Pdx, going through Cys39 and Asp38, and transferring across the interprotein interface to Arg112 (CYP101), then to a hemi: propionate group, and finally to the heme iron center. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Roitberg, AE (reprint author), NIST, Div Biotechnol, Bldg 222,Room A353, Gaithersburg, MD 20899 USA. EM adrian@nist.gov RI Roitberg, Adrian/A-2378-2009; Beratan, David/C-5098-2011 NR 42 TC 65 Z9 65 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 9 PY 1998 VL 120 IS 35 BP 8927 EP 8932 DI 10.1021/ja9739906 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 118VA UT WOS:000075860100005 ER PT J AU Jackson, CL Chanzy, HD Booy, FP Drake, BJ Tomalia, DA Bauer, BJ Amis, EJ AF Jackson, CL Chanzy, HD Booy, FP Drake, BJ Tomalia, DA Bauer, BJ Amis, EJ TI Visualization of dendrimer molecules by transmission electron microscopy (TEM): Staining methods and Cryo-TEM of vitrified solutions SO MACROMOLECULES LA English DT Article ID BLOCK-COPOLYMERS; CHEMISTRY; SHAPE AB Individual dendrimer molecules of poly(amidoamine) (PAMAM) from generation 10 (G10) to G5 were imaged by conventional transmission electron microscopy (TEM) after staining with aqueous sodium phosphotungstate. The dendrimers were resolved as separate, beam-stable entities, and their sizes and distribution of sizes were statistically analyzed and compared with data from small-angle X-ray scattering in solution. Aqueous G10 dendrimers were also characterized by examination in the frozen, hydrated state after quench-freezing in liquid ethane (cryo-TEM) and the data compared with the results of the staining experiments. To a first approximation, the dendrimers appeared circular in projection and the diameters conformed to a Gaussian distribution which broadened somewhat with increasing generation number. Cryo-TEM, in general, confirmed the staining experiments but suggested that, in the native state, there is more variability in the shapes of the dendrimers, with polyhedral shapes occurring quite frequently. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Jackson, CL (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. OI Jackson, Catheryn/0000-0003-1611-3926 NR 27 TC 145 Z9 147 U1 2 U2 30 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 8 PY 1998 VL 31 IS 18 BP 6259 EP 6265 DI 10.1021/ma9806155 PG 7 WC Polymer Science SC Polymer Science GA 118YZ UT WOS:000075869700038 ER PT J AU Collins, BL AF Collins, BL TI Update on the activities of the National Cooperation for Laboratory Accreditation SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Review DE calibration; global market; guide 25; guide 58; laboratory recognition AB The efforts to form a laboratory accreditation cooperation in the United States and North America are described, including activities of the Laboratory Accreditation Working Group and the interim board of the National Cooperation for Laboratory Accreditation. The vision, mission, and guiding principles developed by the two groups are presented, along with the operational documents, such as bylaws, the recognition document, guidance documents and the quality manual drafted by the interim board. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Collins, BL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-1775 J9 ACCREDIT QUAL ASSUR JI Accredit. Qual. Assur. PD SEP PY 1998 VL 3 IS 9 BP 351 EP 355 DI 10.1007/s007690050260 PG 5 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 124PQ UT WOS:000076191200003 ER PT J AU Cheok, GS Stone, WC Kunnath, SK AF Cheok, GS Stone, WC Kunnath, SK TI Seismic response of precast concrete frames with hybrid connections SO ACI STRUCTURAL JOURNAL LA English DT Article DE analytical modeling; beam-column frame; building technology; concrete; hysteresis model; joints (connections); moment resisting; post-tensioning; precast ID ELEMENTS; FAILURE; REGION AB The analytically simulated performance of moment-resisting precast concrete frames with hybrid connections under seismic loads is evaluated An enhanced and versatile hysteretic model was developed to represent the inelastic behavior of the hybrid precast connection region. The model parameters were calibrated using results from a separate experimental program which examined the inelastic cyclic behavior of hybrid concrete precast connections. An interesting feature of the connection was the hybrid combination of mild steel and post-tensioning or post-tensioning steel where the mild steel was used to dissipate energy by yielding and the post-tensioning steel was used to provide the shear resistance through friction developed at the beam-column interface. To simulate the seismic response of actual buildings constructed with such hybrid precast connections, a series of two-dimensional structural models representing typical four; eight, twelve and twenty-two story precast frames was subjected to a series of earthquake motions. The analyses included 29 different accelerograms, representing all three UBC soil types, and were scaled to fit the UBC design spectra. Results of the inelastic dynamic analyses are used in conjunction with experimental results to develop simple design guidelines for the use of precast concrete hybrid connections in regions of high seismicity. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Cent Florida, Orlando, FL 32816 USA. RP Cheok, GS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 15 TC 25 Z9 32 U1 4 U2 11 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 USA SN 0889-3241 J9 ACI STRUCT J JI ACI Struct. J. PD SEP-OCT PY 1998 VL 95 IS 5 BP 527 EP 539 PG 13 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 122QR UT WOS:000076083400007 ER PT J AU Seidensticker, JR Mayo, MJ AF Seidensticker, JR Mayo, MJ TI A topological rationale for the dependence of grain growth on strain during superplastic deformation SO ACTA MATERIALIA LA English DT Article ID MECHANISM; ALUMINUM; CREEP; SHAPE; SIZE AB A model which relates the grain growth which occurs during superplastic deformation to the amount of strain has been developed. This model relies on three-dimensional grain topology, and is based on the premise that as grains grow in a constant volume system, the number of grains must diminish accordingly. During normal grain growth, surrounding grains will occupy-in a generally isotropic manner -the space occupied by a grain which is shrinking and eventually disappears. An applied uniaxial stress will act to bias the movement of surrounding grains into such spaces in a way which results in macroscopic strain. By following the evolution of a single column of grains within a three-dimensional sample loaded in uniaxial compression, the relationship between grain growth and macroscopic strain is predicted to be linear, with a ratio of 0.29. This ratio is a factor or two greater than that which has been observed experimentally, which can be explained by the inability of the present model to account for grains leaving the column in a manner other than by shrinking to zero volume. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Seidensticker, JR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 36 TC 30 Z9 30 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 1 PY 1998 VL 46 IS 14 BP 4883 EP 4893 DI 10.1016/S1359-6454(98)00201-8 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 121LC UT WOS:000076014400004 ER PT J AU Garboczi, EJ Bentz, DP AF Garboczi, EJ Bentz, DP TI Multiscale analytical/numerical theory of the diffusivity of concrete SO ADVANCED CEMENT BASED MATERIALS LA English DT Article DE concrete diffusivity; durability; interfacial transition zone; microstructure; modeling; performance prediction; statistical geometry ID DC ELECTRICAL-CONDUCTIVITY; CEMENT PASTE; INTERFACIAL ZONE; MICROSTRUCTURE; PERCOLATION; SIMULATIONS; MORTARS AB The ionic diffusivity of a concrete is a function of its microstructure at many length scales, ranging from nanometers to millimeters. The microstructure is largely controlled by the initial concrete mixture proportions and the ultimate curing conditions. Linking a property like ionic diffusivity to the microstructure then requires a multiscale approach. A multiscale microstructural computer model for ionic diffusivity has been previously developed. This model has been developed specifically to compute the chloride diffusivity of concretes with various mixture proportions and projected degrees of hydration. The three key parts of this model were dependent on large-scale supercomputer-magnitude simulations to: (1) determine the total volume of interfacial zones for a given aggregate distribution; (2) simulate the hydrate cement paste microstructure around a typical aggregate; and (3) compute the effect of the aggregates and interfacial zones on the overall diffusivity of the concrete. The key feature of this model is that one can approximately take into account the redistribution of cement paste between interfacial transition zone regions and bulk paste regions, and its important effect on overall concrete diffusivity. In the present article, we review the previously developed model and show how analytical equations can accurately replace the large scale computer simulations of parts (1) and (3). This accomplishment will make the model more usable by those who do not have access to supercomputer computing power. Published by Elsevier Science Ltd. C1 NIST, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. RP Garboczi, EJ (reprint author), NIST, Bldg & Fire Res Lab, Bldg Mat Div, 226-B350, Gaithersburg, MD 20899 USA. NR 31 TC 86 Z9 95 U1 1 U2 15 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1065-7355 J9 ADV CEM BASED MATER JI Adv. Cem. Based Mater. PD SEP PY 1998 VL 8 IS 2 BP 77 EP 88 DI 10.1016/S1065-7355(98)00010-8 PG 12 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA ZX378 UT WOS:000074509600004 ER PT J AU Papadopoulos, G Pitts, WM AF Papadopoulos, G Pitts, WM TI Scaling the near-field centerline mixing behavior of axisymmetric turbulent jets SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 36th Aerospace Sciences Meeting CY JAN 12-15, 1998 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID RAYLEIGH LIGHT-SCATTERING; REYNOLDS-NUMBER; DENSITY; ENTRAINMENT; FLOWS; PIPE AB Detailed measurements of the centerline mixing behavior in the near field of variable-density jets were performed. Real-time measurements of jet fluid concentration for a propane jet and a methane jet issuing into still air were made utilizing Rayleigh light scattering. The initial conditions were those of fully developed pipe how and testing was done for how rates yielding Reynolds numbers in the range of 3.3 x 10(3)-2.3 x 10(4), based on the average discharge velocity, exit diameter, and initial fluid properties. Centerline decay characteristics in the near field exhibited a downstream shift with increasing Reynolds number, which was attributed to the initial velocity distribution at the jet exit. Investigation of the mean and turbulent characteristics of the initial velocity distribution yielded a proposed near-field scale variable that effectively captured this dependence on Reynolds number. Collapse of the near-field centerline velocity and concentration distributions was achieved using the proposed scaling. C1 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Papadopoulos, G (reprint author), Dantec Measurement Technol, 777 Corp Dr, Mahwah, NJ 07430 USA. NR 40 TC 18 Z9 18 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 1998 VL 36 IS 9 BP 1635 EP 1642 DI 10.2514/2.565 PG 8 WC Engineering, Aerospace SC Engineering GA 114QM UT WOS:000075620400011 ER PT J AU Emslie, SD Fraser, W Smith, RC Walker, W AF Emslie, SD Fraser, W Smith, RC Walker, W TI Abandoned penguin colonies and environmental change in the Palmer Station area, Anvers Island, Antarctic Peninsula SO ANTARCTIC SCIENCE LA English DT Article; Proceedings Paper CT 1st Workshop on the Late Quaternary Sedimentary Record of the Antarctic Ice Margin Evolution (ANTIME) CY JUL 06-11, 1997 CL HOBART, AUSTRALIA SP SCAR-GLOCHANT, IGBP-PAGES DE abandoned colonies; Adelie penguins; climate change; palaeodiet; palaeoecology ID TROPHIC RELATIONSHIPS; ORNITHOGENIC SOILS; SEA-ICE; ROOKERIES; C-13/C-12; ISOTOPE; CARBON; DIETS; LAND; BAY AB Six abandoned colonies of Adelie penguin (Pygoscelis adeliae) were excavated near Palmer Station, Anvers island, Antarctic Peninsula, to investigate the occupation history of this species. Sediments from each site yielded abundant fish bones and otoliths and squid beaks that represent prey remains deposited by penguins during the nesting period. Radiocarbon analyses indicate that colony occupation began prior to the Little Ice Age (LIA; 1500-1850 AD), with the oldest site dating to 644 yrs before present (sp; average reservoir-corrected date with Is range, 603-679 yr sp). Food remains indicate that the non-euphausiid prey of penguins consisted primarily of a mesopelagic squid (Psychroteuthis glacialis) and two species of fish (Pleuragramma antarcticum and Electrona antarctica). The relative abundance of the first two prey taxa varied significantly among six sites (chi(2) > 34.6; df = 10; P < 0.001) with colonies dating prior to the LIA having greater representation of squid, and less of silverfish, than those occupied during the LIA. Data from control excavations at three modem colonies indicate a diet similar to that of the pre-LIA sites. These results suggest that Adelie penguins may have changed their diet in response to warming and cooling cycles in the past. In addition, only Adelie penguins are known to have nested in the Palmer Station area prior to the 1950s; gentoo (Pygoscelis papua) and chinstrap (P. antarctica) penguins now breeding in this region have expanded their ranges southward in the Peninsula within the past 50 yrs, in correlation with pronounced regional warming. C1 Univ N Carolina, Dept Biol Sci, Wilmington, NC 28403 USA. Montana State Univ, Dept Biol, Polar Oceans Res Grp, Bozeman, MT 59717 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Dept Geog, Santa Barbara, CA 93106 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Emslie, SD (reprint author), Univ N Carolina, Dept Biol Sci, 601 S Coll Rd, Wilmington, NC 28403 USA. NR 39 TC 69 Z9 71 U1 5 U2 17 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0954-1020 J9 ANTARCT SCI JI Antarct. Sci. PD SEP PY 1998 VL 10 IS 3 BP 257 EP 268 PG 12 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 121LL UT WOS:000076015200006 ER PT J AU Parks, RE Shao, LZ Evans, CJ AF Parks, RE Shao, LZ Evans, CJ TI Pixel-based absolute topography test for three flats SO APPLIED OPTICS LA English DT Article AB We demonstrate a method of performing the absolute three-flat test by using reflection symmetries of the surfaces and an algorithm for generating the rotation of arrays of pixel data. Most of the operations involve left/right and top/bottom flips of data arrays, operations that are very fast on most frame grabbers and are available on most commercial phase-measuring interferometers. We demonstrate the method with simulated data as well as with actual data from 150-mm-diameter surfaces that are flat to less than 25 nm peak to valley. (C) 1998 Optical Society of America. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. Opt Perspect Grp, Tucson, AZ 85718 USA. Tucson Opt Res Corp, Tucson, AZ 85719 USA. RP Parks, RE (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 26 TC 40 Z9 45 U1 8 U2 11 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 1998 VL 37 IS 25 BP 5951 EP 5956 DI 10.1364/AO.37.005951 PG 6 WC Optics SC Optics GA 114QH UT WOS:000075620000019 PM 18286090 ER PT J AU Gupta, R Burnett, JH Griesmann, U Walhout, M AF Gupta, R Burnett, JH Griesmann, U Walhout, M TI Absolute refractive indices and thermal coefficients of fused silica and calcium fluoride near 193 nm SO APPLIED OPTICS LA English DT Article ID INDEX; AIR AB The refractive indices of several fused silica and calcium fluoride samples from different suppliers were measured with the minimum deviation method in the deep UV between 191 and 196 nm with a standard uncertainty of 7 ppm. For both materials the dispersion dn/d lambda near 193 nm and 20 degrees C was determined. In addition, we measured the thermal coefficients of the refractive index near 193 nm and between 15 and 25 degrees C. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Calvin Coll, Dept Phys, Grand Rapids, MI 49546 USA. RP Gupta, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 28 Z9 31 U1 2 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 1998 VL 37 IS 25 BP 5964 EP 5968 DI 10.1364/AO.37.005964 PG 5 WC Optics SC Optics GA 114QH UT WOS:000075620000021 PM 18286092 ER PT J AU Lucas, LL AF Lucas, LL TI Calibration of the massic activity of a solution of Tc-99 SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST ID LIQUID AB A solution of Tc-99 was calibrated in terms of massic activity using the NIST 4 pi beta(LS)-gamma-anticoincidence counting system. Co-60 Was used as the efficiency-tracing radionuclide. Measurements were also made using conventional 4 pi beta liquid-scintillation (LS) counting. H-3 was used as the efficiency-monitor radionuclide. The LS detection efficiency ratios, (epsilon(99)/epsilon(3)), were calculated theoretically. The calculated detection efficiency ratios depend strongly upon the assumed shape of the beta spectrum of Tc-99. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NIST, Phys Lab, Radioact Grp, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Lucas, LL (reprint author), NIST, Phys Lab, Radioact Grp, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 10 TC 14 Z9 14 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1061 EP 1064 DI 10.1016/S0969-8043(97)10020-3 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800008 ER PT J AU Zeissler, CJ Wight, SA Lindstrom, RM AF Zeissler, CJ Wight, SA Lindstrom, RM TI Detection and characterization of radioactive particles SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST AB Recent advances in instrumentation provide the capability to measure size, count rate, type of radiation, and the chemical composition of radioactive particles. We present a demonstration of these capabilities, using a laser-scanned phosphor imaging system and a charge injection device system for digital autoradiography, light and electron microscopy, energy dispersive X-ray spectrometry, and conventional radionuclide spectrometry. Response characteristics of the phosphor system that support these efforts are presented. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Zeissler, CJ (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 11 TC 11 Z9 11 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1091 EP 1097 DI 10.1016/S0969-8043(97)10026-4 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800014 ER PT J AU Lucas, LL AF Lucas, LL TI A pulse-recording system for radioactivity measurements SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST ID DATA-ACQUISITION-SYSTEM; COINCIDENCE AB The NIST Radioactivity Group is developing a computer-based pulse-recording system to use for radioactivity measurements. The system consists of a dual ADC module and a plug-in board for an industry-standard-architecture personal computer. The host computer (or another computer) can be programmed to simulate many different logic systems (coincidence, anticoincidence, selective sampling, correlation counting, etc.), so that the pulse data from a given measurement can be analyzed using a wide range of timing parameters and types of logic. (C) 1998 Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Phys Lab, Ionizing Radiat Div, Radioact Grp, Gaithersburg, MD 20899 USA. RP Lucas, LL (reprint author), Natl Inst Stand & Technol, Phys Lab, Ionizing Radiat Div, Radioact Grp, Bldg 245,Room C114, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1141 EP 1146 DI 10.1016/S0969-8043(97)10035-5 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800023 ER PT J AU Schultz, MK Inn, KGW Lin, ZC Burnett, WC Smith, G Biegalski, SR Filliben, J AF Schultz, MK Inn, KGW Lin, ZC Burnett, WC Smith, G Biegalski, SR Filliben, J TI Identification of radionuclide partitioning in soils and sediments: Determination of optimum conditions for the exchangeable fraction of the NIST standard sequential extraction protocol SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST DE exchangeable; uranium; sequential extractions AB We are developing the NIST standard sequential extraction protocol for identifying the fractionation of radioactive elements in soils and sediments. The procedure is designed to partition a soil or sediment sample into six operationally-define fractions. A full-factorial experimental design/data analysis methodology was used to establish the optimum conditions for the first of these six fractions, called "exchangeables". Reaction time, reagent concentration and reaction temperature were chosen as experimental variables. The criteria for choosing optimum conditions were the maximum extraction of U-238 combined with a minimum dissolution of non-targeted geochemical phases. Reagent concentration (i.e. ionic strength) is shown to be the controlling factor in the extraction of exchangeable U-238. The optimum (exchangeable) conditions, based on these experiments:are: time = 1 h; temperature = 25 degrees C and concentration = 0.4 M MgCl2. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. RP Schultz, MK (reprint author), Natl Inst Stand & Technol, Ionizing Radiat Div, Bldg 245,Room C114, Gaithersburg, MD 20899 USA. RI Biegalski, Steven/A-7765-2010 NR 9 TC 23 Z9 23 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1289 EP 1293 DI 10.1016/S0969-8043(97)10062-8 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800050 ER PT J AU Lin, ZC Inn, KGW Altzitzoglou, T Arnold, D Cavadore, D Ham, GJ Korun, M Wershofen, H Takata, Y Young, A AF Lin, ZC Inn, KGW Altzitzoglou, T Arnold, D Cavadore, D Ham, GJ Korun, M Wershofen, H Takata, Y Young, A TI Development of the NIST bone ash standard reference material for environmental radioactivity measurement SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST AB The bone ash standard reference material (SRM), a blend of 4% contaminated human bone and 96% diluent bovine bone, has been developed for radiochemical method validation and quality control for radio-bone analysis. The massic activities of Sr-90, Ra-226, Th-230, Th-232, U-234, U-235, U-238, Pu-238, ((239+240))Pu and ((243+244))Cm were certified using a variety of radiochemical procedures and detection methods. Measurements confirmed undetectable radionuclide heterogeneity down to a sample size of 5 g, thereby implying adequate blending of particulate materials with dilution factors of up to 17,900. The results among most of the intercomparison laboratories and their methods were consistent. Disequilibrium was observed for decay chains: U-231(0.67 mBq/g)-Th-230(0.47 mBq/g)-Ra-226(15,1 mBq/g)-Pb-210(23 mBq/g)-Po-210(13 mBq/g) and Th-232(0.99 mBq/g)-Ra-228(6.1 mBq/g)-Th-228(7.1 mBq/g). The disequilibria were the results of mixing occupationally contaminated human bone with natural bovine bone and the fractionation during internal biological processes. The massic activity of Pb-210, Th-228 and Am-241 were not certified because of insufficient Ra-228 and Pu-241 data and lack of knowledge in how Rn-222 and its daughters will be fractionated in the SRM bottle over time. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Inst Reference Mat & Measurements, ECJRC, B-2440 Geel, Belgium. Phys Tech Bundesanstalt, D-38023 Braunschweig, Germany. LDM, F-30206 Bagnols Sur Ceze, France. Natl Radiol Protect Board, Didcot OX11 0RQ, Oxon, England. Josef Stefan Inst, Ljubljana, Slovenia. Japan Chem Anal Ctr, Chiba 263, Japan. MAFF, Lowestoft NR33 0HT, Suffolk, England. RP Lin, ZC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 4 TC 6 Z9 6 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1301 EP 1306 DI 10.1016/S0969-8043(97)10064-1 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800052 PM 9699291 ER PT J AU Schima, FJ AF Schima, FJ TI Decay of Sr-89 and the emission probability of the 909.12 keV gamma-ray transition SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST DE beta decay; evaluation; photon spectrometry; probability per decay; strontium-89; radioactivity AB Gamma-ray emission rates have been measured for highly pure sources of Sr-89. These sources were prepared with relative Sr-85 activity ratios that ranged from less than 0.606% to undetectable, and had been previously standardized for radioactive concentration. Three such source materials were measured using Ge spectrometers, and the probability per decay of the 909.12 keV gamma ray was found to be 9.555 x 10(-5) with a relative expanded uncertainty of 1.26%. This result and other reported probabilities per decay have been evaluated according to the protocol of the International Atomic Energy Agency Coordinated Research Program on the Measurement and Evaluation of X-ray and Gamma-ray Standards for Detector Efficiency Calibration. This evaluation yielded a recommended value of 9.559 x 10(-5) with a relative standard uncertainty 0.47% for the probability per decay of the 909.12 keV gamma ray. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Schima, FJ (reprint author), Natl Inst Stand & Technol, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1359 EP 1361 DI 10.1016/S0969-8043(97)10074-4 PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800062 ER PT J AU Cassette, P Altzitzoglou, T Broda, R Colle, R Dryak, P De Felice, P Gunther, E Arcos, JML Ratel, G Simpson, B Verrezen, F AF Cassette, P Altzitzoglou, T Broda, R Colle, R Dryak, P De Felice, P Gunther, E Arcos, JML Ratel, G Simpson, B Verrezen, F TI Comparison of activity concentration measurement of Ni-63 and Fe-55 in the framework of the EUROMET 297 project SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST AB Eleven laboratories participated in an intercomparison of activity concentration measurements using liquid scintillation counting (LSC) for the standardization of Ni-63 and Fe-55 in the frame of the EURO-MET project No. 297 and under the co-ordination of LPRI. The purpose of this action was to compare the main LSC activity concentration measurement methods currently used in radioactive metrology, and to exchange models and ideas on LSC. This paper presents a summary of the results reported by the participant laboratories and an overview of the measurement methods used. (C) 1998 The National Physical Laboratory. Elsevier Science Ltd. All rights reserved. C1 CEA, DAMRI, BNM, LPRI, F-91193 Gif Sur Yvette, France. IRMM, EC, JRC, B-2440 Geel, Belgium. RC, PL-05400 Swierk Otwock, Poland. NIST, Radioactiv Grp, Gaithersburg, MD 20899 USA. CMI, Prague 10200 10, Czech Republic. ENEA, CRE Casaccia, I-00100 Rome, Italy. PTB, D-38116 Braunschweig, Germany. CIEMAT, Madrid 28040, Spain. Bur Int Poids & Mesures, F-92312 Sevres, France. Natl Accelerator Ctr, ZA-7131 Faure, South Africa. CEN SCK, Radioprotect Unit, B-2400 Mol, Belgium. RP Cassette, P (reprint author), CEA, DAMRI, BNM, LPRI, BP 52, F-91193 Gif Sur Yvette, France. OI Cassette, Philippe/0000-0001-5254-9183 NR 7 TC 20 Z9 20 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1403 EP 1410 DI 10.1016/S0969-8043(97)10083-5 PG 8 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800071 ER PT J AU Makepeace, J Altzitzoglou, T Cassette, P Dryak, P Gunther, E Verrezen, F Broda, R Simpson, B Unterweger, M AF Makepeace, J Altzitzoglou, T Cassette, P Dryak, P Gunther, E Verrezen, F Broda, R Simpson, B Unterweger, M TI International comparison of measurements of the specific activity of tritiated water SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST AB An international comparison of measurements of the specific activity of tritiated water has been carried out under the auspices of the ICRM Radionuclide Techniques Working Group. The comparison, in which nine laboratories participated, involved the measurement of tritiated water samples of unknown specific activity at up to three different activity levels. The results of the comparison are reported, together with information on the measurement techniques employed and the measurement uncertainties. (C) 1998 The National Physical Laboratory. Published by Elsevier Science Ltd. All rights reserved. C1 Natl Phys Lab, Teddington TW11 0LW, Middx, England. IRMM, JRC, EC, B-2440 Geel, Belgium. CEA, CE Saclay, F-91193 Gif Sur Yvette, France. CMI, IIR, Czech Metrol Inst, Prague 10200 10, Czech Republic. PTB, D-38116 Braunschweig, Germany. CEN SCK, B-2400 Mol, Belgium. Radioisotope Ctr Swierk, PL-05400 Otwock Swierk, Poland. Natl Accelerator Ctr, ZA-7131 Faure, South Africa. NIST, Gaithersburg, MD 20899 USA. RP Makepeace, J (reprint author), Natl Phys Lab, Teddington TW11 0LW, Middx, England. OI Cassette, Philippe/0000-0001-5254-9183 NR 8 TC 15 Z9 17 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1411 EP 1416 DI 10.1016/S0969-8043(97)10084-7 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800072 ER PT J AU Picolo, JL Seralta, S Dulieu, C Day, FE Fennell, S Schrader, H Schotzig, U Unterweger, MP Ratel, G AF Picolo, JL Seralta, S Dulieu, C Day, FE Fennell, S Schrader, H Schotzig, U Unterweger, MP Ratel, G TI International comparison of activity measurements of Xe-133 SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Conference on Radionuclide Metrology and Its Applications (ICRM 97) CY MAY 19-23, 1997 CL NIST, GAITHERSBURG, MARYLAND HO NIST AB An international comparison of Xe-133 activity measurements has been carried out under the auspices of EUROMET (project Nr 304). The project was divided into two stages concerning first the measurement of sealed glass ampoules containing about 40 MBq of Xe-133 at BIPM, LPRI, NPL and PTB and second the measurement at LPRI, NIST and NPL of the radioactivity concentration of Xe-133 mixed with nitrogen with an activity concentration of the order of 50 MBq mol(-1). The experimental techniques employed at each of the participating laboratories are described and a statement of the results and conclusions is provided. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 CEA, CE Saclay, Lab Primaire Rayonnements Ionisants, F-91193 Gif Sur Yvette, France. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany. NIST, Gaithersburg, MD 20899 USA. Bur Int Poids & Mesures, F-92312 Sevres, France. RP Picolo, JL (reprint author), CEA, CE Saclay, Lab Primaire Rayonnements Ionisants, BP 52, F-91193 Gif Sur Yvette, France. NR 11 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-NOV PY 1998 VL 49 IS 9-11 BP 1429 EP 1435 DI 10.1016/S0969-8043(97)10087-2 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 101KU UT WOS:000074868800075 ER PT J AU Maloney, PR Begelman, MC Nowak, MA AF Maloney, PR Begelman, MC Nowak, MA TI Radiation-driven warping. II. Nonisothermal disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; galaxies : structure; instabilities; methods : analytical; X-rays : stars ID ARMED CORRUGATION WAVES; ACCRETION DISKS; EVOLUTION; ORIGIN AB Recent work by Pringle and by Maloney, Begelman, & Pringle has shown that geometrically thin, optically thick, accretion disks are unstable to warping driven by radiation torque from the central source. This work was cofined to isothermal (i.e., surface density Sigma proportional to R-3/2) disks. In this paper we generalize the study of radiation-driven warping to include general power-law surface density distributions, Sigma proportional to R-delta. We consider the range from delta = 3/2 (the isothermal case) to delta = -3/2, which corresponds to a radiation-pressure-supported disk; this spans the range of surface density distributions likely to be found in real astrophysical disks. In all cases there are an infinite number of zero-crossing solutions (i.e., solutions that cross the equator), which are the physically relevant modes if the outer boundary of the disk is required to lie in a specified plane. However, unlike the isothermal disk, which is the degenerate case, the frequency eigenvalues for delta not equal 3/2 are all distinct. In all cases the location of the zero moves outward from the steady state (pure precession) value with increasing growth rate; thus, there is a critical minimum size for unstable disks. Modes with zeros at smaller radii are damped. The critical radius and the steady state precession rate depend only weakly on delta. An additional analytic solution has been found for delta = 1. The case delta = 1 divides the solutions into two qualitatively different regimes. For delta greater than or equal to I, the fastest growing modes have maximum warp amplitude, beta(max), close to the disk outer edge, and the ratio of beta(max) to the warp amplitude at the disk inner edge, beta(0), is much greater than 1. For delta < 1, beta(max)/beta(0) h similar or equal to 1 and the warp maximum steadily approaches the origin as S decreases. This implies that nonlinear effects must be important if the warp extends to the disk inner edge for delta greater than or equal to 1, but for delta < 1 nonlinearity will be important only if the warp amplitude is large at the origin. Because of this qualitative difference in the shapes of the warps, the effects of shadowing of the central source by the warp will also be very different in the two regimes of delta. This has important implications for radiation-driven warping in X-ray binaries, for which the value of delta characterizing the disk is likely to be less than unity. In real accretion disks the outer boundary condition is likely to be different from the zero-crossing condition that we have assumed. In accretion disks around massive black holes in active galactic nuclei, the disk will probably become optically thin before the outer disk boundary is reached, whereas in X-ray binaries there will be an outer disk region (outside the circularization radius) in which the inflow velocity is zero but angular momentum is still transported. We show that in both these cases the solutions are similar to the zero-crossing eigenfunctions. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. RP Maloney, PR (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, Campus Box 391, Boulder, CO 80309 USA. NR 23 TC 28 Z9 28 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 1998 VL 504 IS 1 BP 77 EP 92 DI 10.1086/306047 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152KT UT WOS:000077777200010 ER PT J AU Ackermann, IJ Hass, H Memmesheimer, M Ebel, A Binkowski, FS Shankar, U AF Ackermann, IJ Hass, H Memmesheimer, M Ebel, A Binkowski, FS Shankar, U TI Modal aerosol dynamics model for Europe: Development and first applications SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE regional air quality modeling; modal technique; aerosol dynamics; particle size distribution; inorganic aerosol ID ACID DEPOSITION MODEL; AMMONIUM-NITRATE; TRANSPORT; SIZE; DISSOCIATION; PREDICTIONS; SULFATE; EURAD AB The Modal Aerosol Dynamics model for Europe (MADE) has been developed as an extension to mesoscale chemistry transport models to allow a more detailed treatment of aerosol effects in these models. Due to the complexity of the atmospheric aerosol system an approach has been chosen which is, on the one hand, fast enough for this application and, on the other, provides sufficient information on the particle size distribution. In MADE, which is developed front the regional particulate model (RPM) the particle size distribution of the submicrometer aerosol is represented by two overlapping lognormal modes. The chemical composition is currently treated in the sulfate-nitrate-ammonium and water system. Sources for aerosol particles are modelled through nucleation and emission. Coagulation, condensation, transport and deposition are considered as processes modifying the aerosol population in the atmosphere. Aerosol dynamics calculations are performed on-line within the chemistry-transport model. Process studies with a one-dimensional version of the model system are used to investigate the relative importance of the individual aerosol dynamic processes and the important links between between the gas and aerosol phase as well as meteorological parameters. Results fi-om a first three-dimensional application of the fully coupled system of MADE and the European Air Pollution Dispersion model system (EURAD) are presented, showing the suitability of MADE as an aerosol dynamics model even within complex air quality models. The application of the new aerosol model provides information on particle number, size and surface area in addition to the chemical concentration fields, which can be used to study a variety of aerosol-related air pollution issues in subsequent studies. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Ford Res Ctr Aachen, Aachen, Germany. Univ Cologne, Inst Geophys & Meteorol Project EURAD, Cologne, Germany. NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC USA. MCNC, Res Triangle Pk, NC USA. RP Ackermann, IJ (reprint author), FFA, Dennewartstr 25, D-52068 Aachen, Germany. EM iackerma@ford.com NR 39 TC 280 Z9 287 U1 9 U2 38 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 SEP PY 1998 VL 32 IS 17 BP 2981 EP 2999 DI 10.1016/S1352-2310(98)00006-5 PG 19 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 108MP UT WOS:000075270300011 ER PT J AU Chung, IP Presser, C Dressler, JL AF Chung, IP Presser, C Dressler, JL TI Effect of piezoelectric transducer modulation on liquid sheet disintegration SO ATOMIZATION AND SPRAYS LA English DT Article ID SPRAY AB A stroboscope photographic technique was used to investigate the mechanism associated with the disintegration of a conical liquid sheet that is modulated by a piezoelectric driver. The effects of fluid viscosity, driving frequency, and input perturbation power were characterized with respect to the skeet breakup length. The experimental results indicate that the breakup length decreases with increasing input modulation power only at resonant frequencies. This effect is attributed to waves imposed along the liquid sheet surface that amplify wave-mode and rim-mode disintegration, and assist in liquid sheet breakup. The wavelength generated by the modulation was found to depend on the driving frequency and fluid density. The resonant driving frequency is affected slightly by the fluid density. For our experimental arrangement, art optimum driving frequency, for which the liquid breakup length is a minimum, was found to occur at about 10 kHz. Increasing the liquid viscosity impedes the spray development and lengthens the sheet disintegration. Modulation enhances the disintegration of lower-viscosity fluids but is less effective for higher-viscosity fluids. Higher input modulation power enhances disintegration. The relationship between the breakup length and the modulation power is consistent with the analytical solution suggested by Clark and Dombrowski [1] for breakup of an inviscid two-dimensional flat sheet. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Fluid Jet Associates, Dayton, OH USA. RP Chung, IP (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 18 TC 13 Z9 13 U1 0 U2 0 PU BEGELL HOUSE INC PI NEW YORK PA 79 MADISON AVE, SUITE 1205, NEW YORK, NY 10016-7892 USA SN 1044-5110 J9 ATOMIZATION SPRAY JI Atom. Sprays PD SEP-OCT PY 1998 VL 8 IS 5 BP 479 EP 502 PG 24 WC Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 127QN UT WOS:000076362200001 ER PT J AU Norman, BR Iyengar, V AF Norman, BR Iyengar, V TI The application of preirradiation combustion and neutron activation analysis technique for the determination of iodine in food and environmental reference materials SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article DE ICP-MS; neutron activation analysis; preirradiation combustion; iodine; detection; matrix effects; biological; environmental; reference materials; certification ID INDUCTIVELY-COUPLED PLASMA; MASS-SPECTROMETRY; PREIRRADATION COMBUSTION; MILK POWDER; ICP-MS AB The pre-irradiation combustion (PC) of samples to liberate iodine, followed by trapping the iodine on charcoal and quantifying the element by neutron activation analysis (NAA), has been used at the National Institute of Standards and Technology for the determination of iodine in biological materials. The applicability of this technique to numerous environmental and dietary matrices is illustrated by analysis of a range of certified reference materials (CRMs) and a powdered grass material that was prepared as an in-house reference material (RM). Because of the combustion step involved, samples with low or no fat content (e.g., cereal products, selected botanical specimens, and nonfat milk powder) and inorganic materials (e.g., coal fly ash and dried sediments) are more suited for analysis by this method. In general, the results for several types of samples obtained by this method agreed with those obtained by a second radiochemical (R) NAA, as well as by a third method using inductively coupled plasma mass spectrometry (ICP-MS). PC-NAA is a useful technique for determining iodine in biological and environmental samples, especially for verification of iodine results obtained from other methods. C1 Natl Inst Stand & Technol, CSTL, SRMP, Gaithersburg, MD 20899 USA. RP Iyengar, V (reprint author), Natl Inst Stand & Technol, CSTL, SRMP, Gaithersburg, MD 20899 USA. NR 20 TC 8 Z9 8 U1 0 U2 2 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD SEP PY 1998 VL 63 IS 3 BP 221 EP 229 DI 10.1007/BF02778940 PG 9 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 141AE UT WOS:000077119800006 PM 9840818 ER PT J AU Takagi, S Chow, LC Ishikawa, K AF Takagi, S Chow, LC Ishikawa, K TI Formation of hydroxyapatite in new calcium phosphate cements SO BIOMATERIALS LA English DT Article DE self-setting calcium phosphate cement; TTCP free cement; hydroxyapatite; calcium phosphate biomaterials; phosphate solution ID DICALCIUM PHOSPHATE AB Tetracalcium phosphate (TTCP) has been shown previously to be an essential component of self-setting calcium phosphate cements that form hydroxyapatite (HA) as the only end-product, We report herein on a new self-setting calcium phosphate cement that does not contain TTCP. These cements consist of dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), alpha-tricalcium phosphate, or amorphous calcium phosphate and, as an additional source of calcium, calcium hydroxide or calcium carbonate. These cements require the use of a phosphate (0.2 mol l(-1) or higher) solution or a high pH solution as the cement liquid. The cements harden in relatively short time (5-30 min) and form HA as the dominant end-product in 24 h. The diametral tensile strengths of the 24-h samples are in the range of 0.2 to 7.5 MPa. Results from X-ray diffraction studies suggest that the cement setting is caused by rapid HA formation induced by the high phosphate concentration of the cement liquid. Because DCPA and DCPD are highly soluble at pH values above 12.7, which is the pK(3) of phosphoric acid, high phosphate concentration in the slurry solution was also attainable by using a highly alkaline solution as the cement liquid. The physicochemical properties of these cements are comparable to those of TTCP-containing cements, and the new cements may be expected to have in vivo characteristics similar to those of TTCP-containing cements as well. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Univ Tokushima, Sch Dent, Tokushima 770, Japan. RP Takagi, S (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE05030, DE11789] NR 19 TC 135 Z9 149 U1 2 U2 45 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD SEP PY 1998 VL 19 IS 17 BP 1593 EP 1599 DI 10.1016/S0142-9612(97)00119-1 PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 132YQ UT WOS:000076659900007 PM 9830985 ER PT J AU Stankov, BB AF Stankov, BB TI Multisensor retrieval of atmospheric properties SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GLOBAL POSITIONING SYSTEM; BOUNDARY-LAYER; WATER-VAPOR; TEMPERATURE; HUMIDITY; RASS; ASSIMILATION; RADIOSONDE; SATELLITE AB A new method, Multisensor Retrieval of Atmospheric Properties (MRAP), is presented for deriving vertical profiles of atmospheric parameters throughout the troposphere. MRAP integrates measurements from multiple, diverse, remote sensing, and in situ instruments, the combination of which provides better capabilities than any instrument alone. Since remote sensors can deliver measurements automatically and continuously with high time resolution, MRAP provides better coverage than traditional rawinsondes. MRAP's design is flexible, being capable of incorporating measurements from different instruments in order to take advantage of new or developing advanced sensor technology. Furthermore, new or alternative atmospheric parameters for a variety of applications may be easily added as products of MRAP. A combination of passive radiometric, active radar, and in situ observations provide the best temperature and humidity profile measurements. Therefore, MRAP starts with a traditional, radiometer-based, physical retrieval algorithm provided by the International TOVS (TIROS-N Operational Vertical Sounder) Processing Package (ITPP) that constrains the retrieved profiles to agree with brightness temperature measurements. The first-guess profiles required by the ITPP's iterative retrieval algorithm are obtained by using a statistical inversion technique and ground-based remote sensing measurements. Because the individual ground-based remote sensing measurements are usually of sufficiently high quality, the first-guess profiles by themselves provide a satisfactory solution to establish the atmospheric water vapor and temperature state, and the TOVS data are included to provide profiles with better accuracy at higher levels, MRAP provides a physically consistent mechanism for combining the ground- and space-based humidity and temperature profiles. Data that have been used successfully to retrieve humidity and temperature profiles with MRAP are the following: temperature profiles in the lower troposphere from the ground-based Radio Acoustic Sounding System (RASS); total water vapor measurements from the Global Positioning System; specific humidity gradient profiles from the wind-profiling radar/RASS system; surface meteorological observations from standard instruments; cloud-base heights from a lidar ceilometer; temperature from the Aeronautical Radio, Incorporated Communication, Addressing and Reporting System aboard commercial airlines; and brightness temperature observations from TOVS. Data from the experiment conducted in the late summer of 1995 at Point Loma, California, were used for comparisons of MRAP results and 20 nearby rawinsonde releases to assess the statistical error estimates of MRAP. The temperature profiles had a bias of -0.27 degrees C and a standard deviation of 1.56 degrees C for the entire troposphere. Dewpoint profile retrievals did not have an overall accuracy as high as that of the temperature profiles but they exhibited a markedly improved standard deviation and bias in the lower atmosphere when the wind profiler/RASS specific humidity gradient information was available as a further constraint on the process. The European Centre for Medium-Range Weather Forecasts (ECMWF) model profiles of humidity and temperature for the grid point nearest to the Point Loma site were also used for comparison with the rawinsonde soundings to establish the usefulness of MRAP profiles to the weather forecasting community. The comparison showed that the vertical resolution of the ECMWF model profiles within the planetary boundary layer is not capable of detecting sharp gradients. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Stankov, BB (reprint author), NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NR 47 TC 16 Z9 17 U1 0 U2 5 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 SEP PY 1998 VL 79 IS 9 BP 1835 EP 1854 DI 10.1175/1520-0477(1998)079<1835:MROAP>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 122GT UT WOS:000076064100001 ER PT J AU Vicente, GA Scofield, RA Menzel, WP AF Vicente, GA Scofield, RA Menzel, WP TI The operational GOES infrared rainfall estimation technique SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SATELLITE AB This paper presents a description, sensitivity analyses, sample results, validation, and the recent progress done on the development of a new satellite rainfall estimation technique in the National Environmental Satellite Data and Information Service (NESDIS) at the National Oceanic and Atmospheric Administration (NOAA). The technique, called the auto-estimator, runs in real time for applications to flash flood forecasting, numerical modeling, and operational hydrology. The auto-estimator uses the Geoestationary Operational Environmental Satellite-8 and -9 in the infrared (TR) 10.7-mu m band to compute real-time precipitation amounts based on a power-law regression algorithm. This regression is derived from a statistical analysis between surface-radar-derived instantaneous rainfall estimates and satellite-derived IR cloudtop temperatures collocated in time and space. The rainfall rate estimates are adjusted for different moisture regimes using the most recent fields of precipitable water and relative humidity generated by the National Centers for Environmental Prediction Eta Model. In addition, a mask is computed to restrict rain to regions satisfying two criteria: (a) the growth rate of the cloud as a function of the temperature change of the cloud tops in two consecutive IR images must be positive, and (b) the spatial gradients of the cloud-top temperature field must show distinct and isolated cold cores in the cloud-top surface. Both the growth rate and the gradient corrections are useful for locating heavy precipitation cores. The auto-estimator has been used experimentally for almost 3 yr to provide real-time instantaneous rainfall rate estimates, average hourly estimates, and 3-, 6-, and 24-h accumulations over the conterminous 48 United States and nearby ocean areas. The NOAA/NESDIS Satellite Analyses Branch (SAB) has examined the accuracy of the rainfall estimates daily for a variety of storm systems. They have determined that the algorithm produces useful 1-6-h estimates for flash flood monitoring but exaggerates the area of precipitation causing overestimation of 24-h rainfall total associated with slow-moving, cold-topped mesoscale convective systems. The SAB analyses have also shown a tendency for underestimation of rainfall rates in warm-top stratiform cloud systems. Until further improvements, the use of this technique for stratiform events should be considered with caution. The authors validate the hourly rainfall rates of the auto-estimator using gauge-adjusted radar precipitation products (with radar bias removed) in three distinct cases. Results show that the auto-estimator has modest skill at l-h time resolution for a spatial resolution of 12 km. Results improve with larger grid sizes (48 by 48 km or larger). C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Madison, WI USA. RP Vicente, GA (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, World Weather Bldg,E-RA2,4700 Silver Hill Rd,Stop, Washington, DC 20233 USA. EM gvicente@nesdis.noaa.gov RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 20 TC 173 Z9 182 U1 2 U2 15 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 SEP PY 1998 VL 79 IS 9 BP 1883 EP 1898 DI 10.1175/1520-0477(1998)079<1883:TOGIRE>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 122GT UT WOS:000076064100004 ER PT J AU Hicks, BB AF Hicks, BB TI Wind, water, earth, and fire - A return to an Aristotelian environment SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article; Proceedings Paper CT 78th Annual Meeting of the AMS CY JAN 11-16, 1998 CL PHOENIX, AZ SP AMS ID NITROGEN INPUTS; DEPOSITION; BAY AB The meteorological situation of coastal regions is strongly influenced by the shoreline and by topographic relief. In this instance, we have learned how to take water and land influences into account when predicting changes in meteorology. But we have now stepped beyond the standard meteorological view of coasts affecting air through their complexity, to a new awareness that deposition from the air affects the coastal environment. It is along the coasts that the terrestrial, aquatic, and atmospheric media come into most intimate contact, and where any one of them can affect any other. The importance of the interaction is becoming even more apparent as the population of coastal areas continues to grow, and as demands for energy, food, and recreation are growing even faster. The interactions among the terrestrial, aquatic, and atmospheric media are central in considerations of what must be done to protect an increasingly stressed coastal environment from what could soon be irreversible damage. To generate the understanding necessary to underpin regulations and emissions control strategies, accurate models of pollutant behavior in all of the media must be constructed, and these must then be integrated to protect against the imposition of ineffective controls. The challenges for the atmospheric sciences are daunting. Not only must atmospheric deposition become a focus of attention, but mesoscale models must be constructed to provide the spatial information that existing coarse monitoring networks are incapable of providing alone. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Hicks, BB (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. EM bruce.hicks@noaa.gov NR 20 TC 1 Z9 1 U1 0 U2 0 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 SEP PY 1998 VL 79 IS 9 BP 1925 EP 1933 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 122GT UT WOS:000076064100007 ER PT J AU Eanes, ED Hailer, AW AF Eanes, ED Hailer, AW TI The effect of fluoride on the size and morphology of apatite crystals grown from physiologic solutions SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE apatite; bone mineral; calcification; crystal texture; fluoride ID CALCIUM PHOSPHATES; HYDROXYAPATITE; PH; SOLUBILITY; IONS; CRYSTALLIZATION; MAGNESIUM; PHASES AB In adult human bone, fluoride uptake is accompanied by an increase in apatite crystal size. This increase, however, is not isotropic but is restricted primarily to growth in width and/or thickness, with no measurable change in length. In the present study, seeded growth experiments were conducted in vitro to determine whether this anisotropic effect is physicochemical in origin, i.e., a direct result of F- selectively enhancing lateral crystal growth, or is an indirect consequence of F--induced alterations in cellular function and matrix development. The growth reactions were maintained at 37 degrees C under physiologic-like solution conditions (1.33 mmol/liter Ca2+, 1.0 mmol/liter total phosphate, 0 or 26 mmol/liter carbonate, 270 mmol/kg osmolality, pH 7.4) using constant-composition methods. When new accretions accumulated to three times the initial seed mass, the solids were collected and net crystal growth was assessed by X-ray diffraction Line broadening analysis. The X-ray results revealed that the carbonate constituent in our physiologic-like solutions promoted the proliferation of new crystals at the expense of further growth of the seed apatite. Solution F- concentrations of similar to 2 mu mol/liter partially offset the repressive effect that carbonate had on primary crystal growth. Moreover, F- stimulated seed crystal growth in the same anisotropic manner as had been observed for adult human bone apatite, a finding that suggests that the latter growth in vivo was the consequence, in part, of direct F--mineral interactions. C1 Natl Inst Stand & Technol, NIDR, Craniofacial & Skeletal Dis Branch, Res Associate Program, Gaithersburg, MD 20899 USA. RP Eanes, ED (reprint author), Natl Inst Stand & Technol, NIDR, Craniofacial & Skeletal Dis Branch, Res Associate Program, Bldg 224,Room A143, Gaithersburg, MD 20899 USA. NR 53 TC 16 Z9 16 U1 1 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD SEP PY 1998 VL 63 IS 3 BP 250 EP 257 DI 10.1007/s002239900522 PG 8 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 111XH UT WOS:000075463500012 PM 9701630 ER PT J AU Drake, GWF Martin, WC AF Drake, GWF Martin, WC TI Ionization energies and quantum electrodynamic effects in the lower 1sns and 1snp levels of neutral helium (He-4 I) SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID FINE-STRUCTURE SPLITTINGS; 2-ELECTRON LAMB SHIFTS; N = 1; RYDBERG STATES; FREQUENCY-MEASUREMENT; TRANSITION FREQUENCY; GROUND-STATE; IONS; HYDROGEN; DEUTERIUM AB Ionization energies for several of the lower lying S- and P-states of helium are deduced from a combination of theory and a variety of high-precision measurements of transition energies. High-precision variational methods are reviewed and used to subtract the nonrelativistic energy and lowest order alpha(2) an relativistic corrections from the ionization energies. The remaining quantum electrodynamic (QED) shift of order alpha(3) au and higher is calculated in an extended Kabir-Salpeter formalism and compared with experiment. The comparison verifies the usefulness of the Kabir-Salpeter formalism for terms at least up to order alpha(4) au, and it verifies an asymptotic 1/n(3) scaling law for the two-electron corrections to the Bethe logarithm. The asymptotic scaling law is used to obtain improved semi-empirical estimates for the ionization energies of the higher lying 1sns S-1 and S-3 states up to n = 10. A revised comprehensive listing is given for the ionization energies of all states of helium up to n = 10 and angular momentum L = 7, together with quantum defect extrapolations for the S-states. C1 Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada. NIST, Gaithersburg, MD 20899 USA. RP Drake, GWF (reprint author), Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada. NR 59 TC 74 Z9 74 U1 3 U2 13 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD SEP PY 1998 VL 76 IS 9 BP 679 EP 698 DI 10.1139/cjp-76-9-679 PG 20 WC Physics, Multidisciplinary SC Physics GA 156CF UT WOS:000077983300002 ER PT J AU Subbanna, M Pradip Malghan, SG AF Subbanna, M Pradip Malghan, SG TI Shear yield stress of flocculated alumina-zirconia mixed suspensions: effect of solid loading, composition and particle size distribution SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE yield stress; colloidal processing; mixed suspensions; rheology ID PRESSURE FILTRATION; RHEOLOGY; FLOW AB Yield stress of concentrated mixed suspensions is of considerable importance in processing fine particle suspensions, for example, in colloidal processing of ceramics such as alumina-zirconia bodies, and in management and disposal of wet wastes, slurries, sludges, slimes, etc. We have measured yield stress of flocculated alumina-zirconia mixed suspensions over a wide range of solid loading and composition. Powders employed in these experiments, namely, alumina A16, alumina SR and zirconia Unitec, differ significantly in their fineness and size distribution. A model is presented for shear yield stress of mixed flocculated suspensions by integrating two recent results pertaining to the theology of concentrated suspensions. One, a structural model of shear yield stress for flocculated, single-component suspensions which explicitly incorporates the effects of solid loading and size distribution of the powder. Two, an empirical mixing rule for the effect of solid composition on yield stress of two component systems. The combined model is in good agreement with the experimental data. It could provide useful quantitative information on the role of solid loading, composition and particle size distribution on yield stress of mixed suspensions for an improved understanding of the processing of fine particulate fluids. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Tata Res Dev & Design Ctr, Pune 411013, Maharashtra, India. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Pradip (reprint author), Tata Res Dev & Design Ctr, 54B Hadapsar Ind Estate, Pune 411013, Maharashtra, India. NR 20 TC 24 Z9 26 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD SEP PY 1998 VL 53 IS 17 BP 3073 EP 3079 DI 10.1016/S0009-2509(98)00158-4 PG 7 WC Engineering, Chemical SC Engineering GA 122UQ UT WOS:000076090200005 ER PT J AU Manson, JL Kmety, CR Huang, QZ Lynn, JW Bendele, GM Pagola, S Stephens, PW Liable-Sands, LM Rheingold, AL Epstein, AJ Miller, JS AF Manson, JL Kmety, CR Huang, QZ Lynn, JW Bendele, GM Pagola, S Stephens, PW Liable-Sands, LM Rheingold, AL Epstein, AJ Miller, JS TI Structure and magnetic ordering of M-II[N(CN)(2)](2) (M = Co, Ni) SO CHEMISTRY OF MATERIALS LA English DT Article ID MOLECULAR-BASED MAGNETS; ROOM-TEMPERATURE; CRYSTAL-STRUCTURES; BUILDING-BLOCKS; HEAT-CAPACITY; T-C; FERROMAGNETS; DICYANAMIDE; COMPLEXES; DIFFRACTION AB The reaction of [M-II(OH2)(6)](NO3)(2) (M = Co, Ni) and [N(CN)(2)](-) leads to formation of isomorphous M[N(CN)(2)](2) [M = Co (2a), Ni (3)], respectively, while the reaction of [Co-II(OH2)(6)](NO3)(2) in 1% pyridine (py) solution with [N(CN)(2)](-) leads to the formation of Co[N(CN)(2)](2)py(2). The structure of 2a, alpha-Co[N(CN)(2)](2), was determined from the Rietveld analyses of both powder X-ray (synchrotron) and neutron as well as single-crystal X-ray diffraction data, whereas the structure of 3 was determined from the Rietveld analysis of powder neutron diffraction data. 2a (pink) and 3 (light blue) belong to the orthorhombic space group Pnnm with Z = 2 [2a (single crystal): a = 5.9985(15), b = 7.0711(18), c = 7.4140(19) Angstrom, V = 314.47(14) Angstrom(3), R-1 = 0.027. 3 (powder neutron diffraction): a = 5.97357(25), b = 7.03196(28), c = 7.29424(22) Angstrom, V = 306.40(3) Angstrom(3), chi(2) = 1.650]. Thermolysis of Co[N(CN)(2)](2)py(2) leads to intensely blue beta-Co-II[N(CN)(2)](2), 2b. The M in 2a and 3 are six-coordinate and bound to six different mu(3)-bonded [N(CN)(2)](-) ligands, forming a rutile-like 3-D framework. Both M-II sites are slightly tetragonally elongated, with average axial M-N distances (295 K) of 2.161(5) (2a) and 2.137(2) A (3) and average equatorial M-N distances of 2.091(4) (2a) and 2.051(1) Angstrom (3), and each M-II is coordinated to four equatorial [N(CN)(2)](-) ligands that bridge between two adjacent M-II sites, generating ribbon-like 1-D chains that propagate along the c-axis. Adjacent chains pack out-of-registry, with the central N2s bridging to M-II ions of adjacent chains, forming a 3-D network. [N(CN)(2)](-) has pseudo-C-2v symmetry with average C1 = N1 distances of 1.158 (2a) and 1.159 Angstrom (3) at room temperature and C1-N2 distances of 1.315 (2a) and 1.313 A (3). The structure of 2b has not yet been elucidated, but on the basis of the color and magnetic properties, it is thought; to be comprised of tetrahedral Co(II). The shortest M...M separations are 5.936 (2a) and 5.881 Angstrom (3) at room temperature via neutron diffraction studies. The susceptibility for 2a, 2b, and 3 can be fit by the Curie-Weiss expression with g = 2.60, theta = 9 K (T > 50 K); g = 2.27, theta = -7 K (T > 60 K); and g = 2.20, theta = 21 K (T > 50 K), respectively. The observed room-temperature effective moments of 5.13, 4.37, and 3.17 mu(B), respectively, exceed the spin-only moments as expected for these metal ions, but are consistent with octahedral Co(II), tetrahedral Co(II), and octahedral Ni(II), respectively. Ferromagnetic behavior is suggested for 2a and 3 from the 5 K, 5.5 T saturation magnetizations of 14 000 (2a) and 11 900 emu Oe/mol (3), hysteresis loops with coercive fields, H-cr, of 800 (2a), 680 (2b), and 7000 Oe (3) at 2 K, field-cooled and zero-field-cooled low-field M(T) data showing magnetic ordering below essentially magnetic field-independent bifurcation temperatures of 9.2 (2a) and 20.6 K (3), and observations of both in-phase, chi'(T), and out-of-phase, chi "(T), components of the ac susceptibility maxima slightly below the bifurcation temperatures. The T(c)s are estimated from the peaks in the 10 Hz XI(T) data to be 8.7, 8.9, and 19.7 K for 2a, 2b, and 3, respectively. Using mean-field theory the spin-coupling energies, J/k(B), were estimated to be 0.45, -0.7, and 2.0 K for 2a, 2b, and 3, respectively. 2b shows canted antiferromagnetic behavior below its ordering temperature of 8.9 K. A second transition at 2.7 K, as observed in ac susceptibility, specific heat, and field-cooled/zero-field-cooled magnetization studies, suggests the possibility of an initially canted antiferromagnetic ground state with a change in canting angle below 2.7 K. C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Miller, JS (reprint author), Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. OI PAGOLA, SILVINA/0000-0003-2083-7599 NR 75 TC 278 Z9 280 U1 6 U2 46 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP PY 1998 VL 10 IS 9 BP 2552 EP 2560 DI 10.1021/cm980321y PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 123XH UT WOS:000076150600042 ER PT J AU Fowler, HA Devaney, JE Hagedorn, JG Sullivan, FE AF Fowler, HA Devaney, JE Hagedorn, JG Sullivan, FE TI Dielectric breakdown in a simplified parallel model SO COMPUTERS IN PHYSICS LA English DT Article ID GROWTH AB The growth of streamer trees in insulating fluids (a submicrosecond process that triggers high-voltage breakdown) has been simulated with a combination of parallel-coding tools. Large grids and arrays display well the multifractal, self-avoiding character of the streamer trees. Three physical cases have been approximated by different power-law weightings of the statistical growth filter: dense anode trees, in the uniform field; sparse cathode trees (a rarer experimental case); and ultrasparse anode trees (seen in some fluids of higher viscosity). The model is contained in a software package that is written in Fortran 90 with data parallel extensions for distributed execution. These extensions encapsulate an underlying, invisible message-passing environment, thus enabling the solution of memory-intensive problems on a group of limited-memory processors. Block partitioning creates processes of reasonable size, which operate in parallel like small copies of the original code. The user needs only to express his model in transparent array-directed commands; parallel interfacing between blocks is handled invisibly. Breakdown is performed in parallel in each of the local blocks. Results are presented for experiments run on eight and nine nodes of the IBM SP2. and four and eight nodes of the SGI Onyx and Origin, three examples of multiple-processor machines. Display is carried out in three dimensions. Timing of the growth can be shown by color banding or by frame animation of the results. The adequacy of the growth rules and size scaling are tested by comparing the simulations against snapshots from high-voltage discharge events. C1 NIST, High Performance Syst & Serv Div, Informat Technol Lab, Gaithersburg, MD 20899 USA. Inst Def Anal, Ctr Comp Sci, Bowie, MD 20715 USA. RP NIST, High Performance Syst & Serv Div, Informat Technol Lab, Gaithersburg, MD 20899 USA. EM howland.fowler@nist.gov; judith.devaney@nist.gov; john.hagedorn@nist.gov; fran@super.org NR 31 TC 6 Z9 6 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0894-1866 J9 COMPUT PHYS JI Comput. Phys. PD SEP-OCT PY 1998 VL 12 IS 5 BP 478 EP 487 DI 10.1063/1.168738 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Computer Science; Physics GA 130AY UT WOS:000076498100020 ER PT J AU Boisvert, RF Dongarra, JJ Pozo, R Remington, KA Stewart, GW AF Boisvert, RF Dongarra, JJ Pozo, R Remington, KA Stewart, GW TI Developing numerical libraries in Java SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article ID MATRIX AB The rapid and widespread adoption of Java has created a demand for reliable and reusable mathematical software components to support the growing number of computationally intensive applications now under development, particularly in science and engineering. In this paper we address practical issues of the Java language and environment which have an effect on numerical library design and development. Benchmarks which illustrate the current levels of performance of key numerical kernels on a variety of Java platforms me presented. Finally, a strategy for the development of a fundamental numerical toolkit for Java is proposed and its current status is described, (C) 1998 John Wiley & Sons, Ltd. C1 NIST, Div Math & Comp Sci, Informat Technol Lab, Gaithersburg, MD 20899 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. RI Dongarra, Jack/E-3987-2014; OI Boisvert, Ronald/0000-0002-4445-1044 NR 15 TC 11 Z9 11 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD SEP-NOV PY 1998 VL 10 IS 11-13 BP 1117 EP 1129 DI 10.1002/(SICI)1096-9128(199809/11)10:11/13<1117::AID-CPE386>3.3.CO;2-9 PG 13 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 150CB UT WOS:000077644300029 ER PT J AU Short, JW Heintz, RA AF Short, JW Heintz, RA TI Source of polynuclear aromatic hydrocarbons in Prince William Sound, Alaska, USA, subtidal sediments SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Letter C1 Natl Marine Fisheries Serv, Auke Bay Lab, NOAA, Juneau, AK USA. RP Short, JW (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, NOAA, Juneau, AK USA. NR 3 TC 0 Z9 0 U1 1 U2 2 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD SEP PY 1998 VL 17 IS 9 BP 1651 EP 1651 PG 1 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 112NX UT WOS:000075501600001 ER PT J AU Hettler, WF Hare, JA AF Hettler, WF Hare, JA TI Abundance and size of larval fishes outside the entrance to Beaufort Inlet, North Carolina SO ESTUARIES LA English DT Article ID STATES CONTINENTAL-SHELF; MIDDLE ATLANTIC BIGHT; STREAM FRONTAL EDDY; BREVOORTIA-TYRANNUS; CHESAPEAKE BAY; WIND STRESS; VARIABILITY; TRANSPORT; MENHADEN; ESTUARY AB Synoptic ichthyoplankton sampling was conducted on two transects, one on either side of Beaufort Inlet, North Carolina, during the winter immigration season of seven ocean-spawned, estuarine-dependent fishes; Brevoortia tyrannus (Atlantic menhaden), Leiostomus xanthurus (spot), Micropogonias undulatus (Atlantic croaker), lagodon rhomboides (pinfish), Paralichthys albigutta (Gulf flounder), P. dentatus (summer flounder), and Ei lethostigma (southern flounder). Densities and lengths of larvae were significantly different among sampling dates, with distance offshore, and between sides of the inlet. Flood-tide stage had minimal effect on larval densities and lengths except for P. albigutta and P. lethostigma. Changes in larval densities with distance offshore were not coherent among species; densities of B. tyrannus increased offshore whereas densities of the other species decreased offshore. Average larval densities on a sampling date were coherent among species. Patterns in larval lengths were also coherent among the four non-pounder species. Larval densities outside of Beaufort Inlet were correlated with larval densities inside of Beaufort Inlet. Larval densities outside of Beaufort Inlet were also correlated with the north component of the wind, nearshore water temperature, and distance to the mid-shelf front. Differences in larval density across the inlet were significantly correlated with the east component of the wind. The patterns in larval densities outside of Beaufort Inlet were complex and apparently influenced by both the physical processes that supply larvae to the nearshore region and nearshore physical dynamics. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. RP Hare, JA (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM jhare@hatteras.bea.nmfs.gov NR 50 TC 26 Z9 26 U1 0 U2 10 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1998 VL 21 IS 3 BP 476 EP 499 DI 10.2307/1352846 PG 24 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 122WK UT WOS:000076094300011 ER PT J AU Ovchinnikov, YB Manek, I Sidorov, AI Wasik, G Grimm, R AF Ovchinnikov, YB Manek, I Sidorov, AI Wasik, G Grimm, R TI Gravito-optical atom trap based on a conical hollow beam SO EUROPHYSICS LETTERS LA English DT Article ID DIPOLE TRAP; MAGNETOOPTICAL TRAP; CESIUM ATOMS; COLD ATOMS; SURFACE; DENSITY AB We demonstrate a novel optical dipole-force trap, which uses an intense blue-detuned conical hollow laser beam together with gravity to confine an ensemble of cesium atoms in a dark spatial region. Efficient cooling is provided by a 3D optical molasses in combination with inelastic reflections from the trapping field. The particular advantages of the trap are its experimental simplicity, the high loading efficiency, and a strong suppression of losses caused by ultracold collisions. C1 Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ Melbourne, Sch Phys, Melbourne, Vic, Australia. Jagiellonian Univ, Inst Phys, Krakow, Poland. RP Ovchinnikov, YB (reprint author), NIST, PHY B167, Gaithersburg, MD 20899 USA. RI Grimm, Rudolf/D-2864-2009 OI Grimm, Rudolf/0000-0003-1085-5558 NR 19 TC 28 Z9 28 U1 0 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP 1 PY 1998 VL 43 IS 5 BP 510 EP 515 DI 10.1209/epl/i1998-00390-9 PG 6 WC Physics, Multidisciplinary SC Physics GA 114MC UT WOS:000075612400004 ER PT J AU Berger, JR Drexler, ES Read, DT AF Berger, JR Drexler, ES Read, DT TI Error analysis and thermal expansion measurement with electron-beam moire SO EXPERIMENTAL MECHANICS LA English DT Article AB In this paper, the authors study errors incurred when using the experimental technique of electron-beam moire. There are two sources of error: error manifested as an apparent magnification drift and error due to fringe tracing. The error due to fringe tracing is nearly negligible in comparison to the error due to magnification drift. By investigating the thermal expansion of commercially pure copper, the authors demonstrate the usefulness of the error estimate. The average result for the coefficient of thermal expansion is within 1.8 percent of handbook values for this material, with a possible error due to apparent magnification drift of 9 percent. C1 Colorado Sch Mines, Div Engn, Golden, CO 80401 USA. Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Berger, JR (reprint author), Colorado Sch Mines, Div Engn, Golden, CO 80401 USA. RI Berger, John/F-5169-2010 NR 10 TC 10 Z9 10 U1 0 U2 1 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD SEP PY 1998 VL 38 IS 3 BP 167 EP 171 DI 10.1007/BF02325739 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 114MH UT WOS:000075612900003 ER PT J AU Fahey, SO Pratt, J AF Fahey, SO Pratt, J TI Frequency domain modal estimation techniques SO EXPERIMENTAL TECHNIQUES LA English DT Article C1 Elect Boat Corp, Groton, CT 06340 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Fahey, SO (reprint author), Elect Boat Corp, Groton, CT 06340 USA. NR 8 TC 9 Z9 10 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 USA SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD SEP-OCT PY 1998 VL 22 IS 5 BP 33 EP 37 DI 10.1111/j.1747-1567.1998.tb02320.x PG 5 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 126NJ UT WOS:000076299700008 ER PT J AU Cooper, LY AF Cooper, LY TI Simulating smoke movement through long vertical shafts in zone-type compartment fire models SO FIRE SAFETY JOURNAL LA English DT Article ID DUCTS AB A limitation of traditional zone-type compartment fire modeling is the inadequacy of two-layer quasi-steady-buoyant-plume analyses to simulate the fire-generated environment in room configurations with large height-to-span ratios, e.g., elevator shafts and ventilation shafts. Model equations to remove this limitation are developed. These simulate time-dependent flow in a long, ventilated, vertical shaft with an arbitrary vertical density distribution, including one or more intervals along the shaft length where the vertical distribution of the averaged cross-section density may be unstably stratified, i.e., density increasing with increasing elevation. The model equations are partially verified by favorable comparisons between solutions and previously published data from unsteady experiments in long vertical tubes involving initially unstable configurations: saltwater over freshwater and heavy gas over light gas. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Cooper, LY (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 5 TC 13 Z9 20 U1 2 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD SEP PY 1998 VL 31 IS 2 BP 85 EP 99 DI 10.1016/S0379-7112(98)00070-8 PG 15 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 120NB UT WOS:000075961500001 ER PT J AU Grimes, CB AF Grimes, CB TI Marine Stock Enhancement: Sound management or techno-arrogance? SO FISHERIES LA English DT Article C1 Natl Marine Fisheries Serv, Santa Cruz Tiburon Lab, Tiburon, CA 94920 USA. RP Grimes, CB (reprint author), Natl Marine Fisheries Serv, Santa Cruz Tiburon Lab, 3150 Paradise Dr, Tiburon, CA 94920 USA. NR 6 TC 23 Z9 28 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0363-2415 J9 FISHERIES JI Fisheries PD SEP PY 1998 VL 23 IS 9 BP 18 EP 23 DI 10.1577/1548-8446(1998)023<0018:MSE>2.0.CO;2 PG 6 WC Fisheries SC Fisheries GA 114JV UT WOS:000075606300007 ER PT J AU Mcgillicuddy, DJ Lynch, DR Moore, AM Gentleman, WC Davis, CS Meise, CJ AF Mcgillicuddy, DJ Lynch, DR Moore, AM Gentleman, WC Davis, CS Meise, CJ TI An adjoint data assimilation approach to diagnosis of physical and biological controls on Pseudocalanus spp. in the Gulf of Maine-Georges Bank region SO FISHERIES OCEANOGRAPHY LA English DT Article DE adjoint method; data assimilation; Georges Bank; Gulf of Maine; population dynamics; Pseudocalanus; zooplankton ID EQUATORIAL OCEAN MODEL; BOUNDARY-CONDITIONS; COASTAL CURRENT; CIRCULATION; EQUATIONS; FLOWS AB The underlying scientific objective here is to determine the mechanisms that control seasonal variations in the abundance of Pseudocalanus spp. in the Georges Bank-Gulf of Maine region. It is postulated that the observed distributions result from the interaction of the population dynamics with the climatological circulation. The problem is posed mathematically as a 2-D advection-diffusion-reaction equation for a scalar variable. Given an initial distribution of animals, we seek the population dynamics source term R(x,y) such that integration of the forward model will result in predictions3 that minimize the sum of squares of differences with observed concentrations at a later time. An adjoint data assimilation technique has been designed for these purposes. This approach has been used to invert for the population dynamics associated with the transition between bimonthly (i.e. for 2 months) climatological Pseudocalanus spp. distributions derived from MAR-MAP data. Vertically averaged velocity and diffusivity fields diagnosed from hydrodynamical simulations of the climatological flow are specified. Solutions converge rapidly, and the procedure reduces the cost function by an order of magnitude within 50 iterations. The resulting population dynamics vary considerably in space and time, as does the balance between local tendency, physical transport and biological source terms, Generally speaking, the patterns in population dynamics are not inconsistent with current knowledge concerning potential controls such as predation and food limitation Analysis of the solutions indicates that the Pseudocalanus spp. population centres located in the western Gulf of Maine and on Georges Bank may be self-sustaining, in contrast to Frier studies which characterize the former as a source region for the latter. C1 Woods Hole Oceanog Inst, Dept Appl Ocean Phys & Engn, Woods Hole, MA 02543 USA. Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Woods Hole Oceanog Inst, Dept Biol, Woods Hole, MA 02543 USA. NOAA, NE Fisheries Sci Ctr, Highlands, NJ 07732 USA. RP Mcgillicuddy, DJ (reprint author), Woods Hole Oceanog Inst, Dept Appl Ocean Phys & Engn, Woods Hole, MA 02543 USA. NR 35 TC 50 Z9 50 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD SEP-DEC PY 1998 VL 7 IS 3-4 BP 205 EP 218 DI 10.1046/j.1365-2419.1998.00066.x PG 14 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 154AF UT WOS:000077865300005 ER PT J AU Manooch, CS Potts, JC Vaughan, DS Burton, ML AF Manooch, CS Potts, JC Vaughan, DS Burton, ML TI Population assessment of the red snapper from the southeastern United States SO FISHERIES RESEARCH LA English DT Article DE stock assessment; red snapper; southeastern United States ID GROWTH; PARAMETERS; MORTALITY AB Changes in the age structure and population size of red snapper, Lutjanus campechanus, from North Carolina through the Florida Keys were examined using records of landings and size frequencies of fish from commercial, recreational, and headboat fisheries from 1986 to 1995. Population size in numbers at age was estimated for each year by applying separable virtual population analysis (SVPA) to the landings in numbers at age. SVPA was used to estimate annual, age-specific fishing mortality (F) for four levels of natural mortality (M = 0.15, 0.20, 0.25, and 0.30). Although landings of red snapper for the three fisheries have declined, minimum fish size regulations have also resulted in an increase in the mean size of red snapper landed. Age at entry and age at full recruitment were age-1 for 1986-1991, compared with age-2 and age-6, respectively, for 1992-1995. Levels of mortality from fishing (F) ranged from 0.31 to 0.69 for the entire period. Spawning potential ratio (SPR) increased from 0.09 to 0.24 (M = 0.25) from 1986 to 1995. The SPR level could be improved with a decrease in F, or an increase in age at entry to the fisheries. The latter could be enhanced now if fishermen, particularly recreational fishermen, comply with minimum size regulations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. RP Manooch, CS (reprint author), Natl Marine Fisheries Serv, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM cmanooch@hatteras.bea.nmfs.gov NR 28 TC 13 Z9 13 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD SEP PY 1998 VL 38 IS 1 BP 19 EP 32 DI 10.1016/S0165-7836(98)00112-X PG 14 WC Fisheries SC Fisheries GA 127NQ UT WOS:000076357800003 ER PT J AU Kiselev, SB Belyakov, MY Rainwater, JC AF Kiselev, SB Belyakov, MY Rainwater, JC TI Crossover Leung-Griffiths model and the phase behavior of binary mixtures with and without chemical reaction SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE benzene; binary mixtures; carbon dioxide; chemical reaction; critical phenomena; equation of state; ethane; methanol; n-butane; phase behavior; propane; sodium chloride; thermodynamic properties; water ID VAPOR-LIQUID-EQUILIBRIUM; CARBON-DIOXIDE; THERMODYNAMIC PROPERTIES; HIGH-PRESSURES; METHANOL; TEMPERATURES; SYSTEMS; (VAPOR; WATER; MPA AB A new theoretical crossover model for the phase behavior of binary mixtures is presented that corresponds to the Leung-Griffiths model in the critical region and is transformed into the regular classical expansion far away from the critical point. The model is optimized to, and leads to good agreement with, experimental vapor-liquid equilibrium data for CO2 + n-butane, CO2 + propane, ethane + benzene, CO2 + methanol, and dilute aqueous solutions of NaCl in the extended critical region. Phase behavior of mixtures in the presence of chemical reaction and a possibility to incorporate this phenomenon into the model are also discussed. Published by Elsevier Science B.V. C1 NIST, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Kiselev, SB (reprint author), NIST, Div Thermophys 838 08, 325 Broadway, Boulder, CO USA. NR 22 TC 14 Z9 14 U1 0 U2 1 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 SEP PY 1998 VL 150 BP 439 EP 449 DI 10.1016/S0378-3812(98)00291-X PG 11 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300047 ER PT J AU Van Poolen, LJ Rainwater, JC AF Van Poolen, LJ Rainwater, JC TI Critical-region model for bubble curves of ammonia-water with extrapolation to low pressures SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE ammonia-water; critical state; Leung-Griffiths model; low-pressure extrapolation; mixture; vapor-liquid equilibria ID VAPOR-LIQUID-EQUILIBRIUM; THERMODYNAMIC PROPERTIES; SYSTEM AMMONIA; MIXTURES AB A modified Leung-Griffiths correlation for the near-critical phase boundary of ammonia-water is extrapolated to low pressure. The extrapolation is based on the observation that, on a plot of logarithm of pressure vs. inverse temperature, dew and bubble isopleths form straight lines below the critical region. The extrapolation is performed both directly and with additional optimization to a chosen low-pressure data set. On the bubble side, the method yields a useful baseline calculation against which different experimental measurements can be tested for mutual consistency, but the approach is considerably less successful on the dew side. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Calvin Coll, Dept Engn, Grand Rapids, MI 49546 USA. RP Rainwater, JC (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 18 TC 2 Z9 2 U1 0 U2 1 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 SEP PY 1998 VL 150 BP 451 EP 458 DI 10.1016/S0378-3812(98)00292-1 PG 8 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300048 ER PT J AU Kiselev, SB Rainwater, JC Huber, ML AF Kiselev, SB Rainwater, JC Huber, ML TI Binary mixtures in and beyond the critical region: thermodynamic properties SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE acentric factor; binary mixtures; critical region; equation of state; ethane; n-butane; phase behavior; R12; R22; R13B1; R114; thermodynamic properties ID COMPRESSED LIQUID DENSITIES; THERMOPHYSICAL PROPERTIES; TEMPERATURE RELATIONS; SATURATION DENSITIES; PENTAFLUOROETHANE; PRESSURES; VAPOR; MODEL; STATE; CHLORODIFLUOROMETHANE AB An extended law of corresponding states, in combination with a parametric crossover equation of state, is applied to the prediction of thermodynamic properties and phase behavior of pure fluids and binary mixtures over a wide region around vapor-liquid critical points. For pure fluids, a generalized form of the model is given that requires only the acentric factor of the pure component. For mixtures, the critical locus is also required. A good representation of thermodynamic property data is achieved in the range of temperatures 0.8 T-c(x) less than or equal to T less than or equal to 1.5 T-c(x) and densities 0.35 rho(c)(x) less than or equal to rho less than or equal to 1.65 rho(c)(x). Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Rainwater, JC (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 36 TC 28 Z9 28 U1 0 U2 3 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 SEP PY 1998 VL 150 BP 469 EP 478 DI 10.1016/S0378-3812(98)00294-5 PG 10 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300050 ER PT J AU Abdulagatov, IM Dvoryanchikov, VI Mursalov, BA Kamalov, AN AF Abdulagatov, IM Dvoryanchikov, VI Mursalov, BA Kamalov, AN TI Measurements of the heat capacity at constant volume of H2O+Na2SO4 in near-critical and supercritical water SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE aqueous ionic solutions; coexistence curve; critical point; equation of state; heat capacity; sodium sulfate; water ID CRITICAL REGION; CRITICAL-POINT; IONIC FLUIDS; MIXTURES; EQUATION; NACL-H2O; STATE; BEHAVIOR AB The heat capacity at constant volume C-VX of aqueous solutions of Na,SO, has been measured from 460 to 669 K along 11 isochores from 250 to 926 kg m(-3) for three compositions, namely: 0.0012798; 0.0066328, and 0.0139002 mole fraction of Na,SO,. Measurements of the isochoric heat capacity C-V for pure water were also made at the critical isochore(rho(c) = 317.9 kg m(-3)) and at six near-critical isochores, namely: 309.598, 335.570, 354.480, 368.310, 370.370 and 373.340 kg m(-3), and the coexistence curve. A total of 368 C-VX data for H2O + Na2SO4 and 273 C-V data for pure water were measured along 17 isochores in the one- and two-phase regions. The measurements were made in a high-temperature and high-pressure adiabatic nearly constant-volume calorimeter. The uncertainty of the isochoric heat capacity measurements is estimated to be within +/-2%. One-(C'(V)) and two-phase (C"(V)) heat capacities, temperatures (T-S), and densities (rho(S)) at saturation were obtained by the method of quasi-static thermograms. The experimental C-VX results have been compared with Fitter's classical equation of state. The relative average deviations for H2O + Na2SO4 solutions were about +/-2%, except for the critical region where differences reached 15-20%. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Makhachkala 367030, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, Thermophys Div 83808, 325 Broadway, Boulder, CO 80303 USA. NR 28 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD SEP PY 1998 VL 150 BP 525 EP 535 DI 10.1016/S0378-3812(98)00299-4 PG 11 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300055 ER PT J AU Abdulagatov, IM Bazaev, AR Bazaev, EA Saidakhmedova, MB Ramazanova, AE AF Abdulagatov, IM Bazaev, AR Bazaev, EA Saidakhmedova, MB Ramazanova, AE TI PVTx measurements and partial molar volumes for water-hydrocarbon mixtures in the near-critical and supercritical conditions SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE apparent molar volume; critical state; density; excess molar volume; partial molar volume; piezometer; pressure; supercritical fluid; water ID VIRIAL-COEFFICIENTS; AQUEOUS MIXTURES; N-HEXANE; DILUTE AB By means of a constant-volume piezometer, measurements have been made of the PVTx properties of water + hydrocarbon (n-heptane, n-octane, and benzene) mixtures at near-critical and supercritical conditions. The measurements cover the pressure range from 5 to 40 MPa and densities between 20 and 450 kg m(-3) for six compositions from 0 to 0.614 mole fraction of hydrocarbon. Tests on the piezometer and consistency tests on the measurements suggest that the results are free from significant 'dead volume' error. The experimental errors of the present PVTx measurements are estimated to be within +/- 0.01 K in temperature, +/- 0.15% in density, +/- 2 kPa in pressure, and +/- 0.002 mole fraction in composition. Good agreement was obtained with values reported in the literature for pure components (water, n-heptane, n-octane, and benzene), measured using other techniques. Values of partial molar volumes and the Krichevskii parameter have been obtained from these measurements. Analysis of the results for dilute water-hydrocarbon mixtures shows that partial molar volumes of the hydrocarbon (solute) near the critical point of pure water (solvent) exhibit remarkable anomalies. The experimental results have been interpreted in terms of modern molecular thermodynamic models for the partial molar volumes of the solute near the solvent critical point and Kirkwood-Buff fluctuation theory of solutions in terms of direct correlation function integral. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Makhachkala 367030, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, Thermophys Div 83808, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 24 Z9 25 U1 1 U2 5 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 SEP PY 1998 VL 150 BP 537 EP 547 DI 10.1016/S0378-3812(98)00300-8 PG 11 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300056 ER PT J AU Weber, LA Defibaugh, DR AF Weber, LA Defibaugh, DR TI Procedure for estimating the effects of impurities on measured vapor pressures SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE azeotrope; distribution coefficient; impurity; mixtures; vapor pressure ID LIQUID-EQUILIBRIUM; COEFFICIENTS; EBULLIOMETRY; SYSTEMS AB A thermodynamic relationship is used to describe how the presence of an impurity affects measured vapor pressures by relating the effect to the distribution coefficient, K, of the impurity. In practical situations K is estimated simply by analysis with a gas chromatograph. A second relationship is used to describe how K, and thus the effect, varies with temperature. The effect of azeotropic behavior on the temperature variation is also considered. Several examples are given, including the systems CH2F2 + CF3CH2F (HFC32 + HFC134a), CF3CF2Cl + CF3CHF2 (HCFC115 + CFC125), CHF2CF2CH2F + CF3CF2CF2CH2F (HFC245ca + HFC338mccq), and samples of CF3CH2CF3 (HFC236fa) and n-heptane with impurities. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Weber, LA (reprint author), 110 Whaley Lane, Reedville, VA 22539 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 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 SEP PY 1998 VL 150 BP 731 EP 738 DI 10.1016/S0378-3812(98)00353-7 PG 8 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300078 ER PT J AU Holcomb, CD Outcalt, SL AF Holcomb, CD Outcalt, SL TI A theoretically-based calibration and evaluation procedure for vibrating-tube densimeters SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE vibrating-tube densimeter; calibration equation; propane plus i-butane ID PRESSURES; (VAPOR AB A calibration procedure for vibrating-tube densimeters is developed which properly accounts for the effects of pressure and temperature on the Young's modulus and internal volume of the vibrating-tube. The calibration equation is based on the theoretical dependence of the Young's modulus, the compressibility, and the thermal expansion coefficient of the tube material on temperature and pressure. Experience shows that the vibration period of the evacuated tube can shift a small amount over time as the stresses in the tube and welds age. Therefore, the calibration equation is formulated relative to a vacuum reference period to adjust for these shifts. A first-order approximation of our theoretically-based equation is also derived. The calibration procedure is accomplished in two parts. First, the evacuated tube is calibrated to characterize the elastic modulus and linear thermal expansion coefficient of the tube as a function of temperature. Second, the change of the internal volume of the tube with temperature and pressure is characterized using two or more well-characterized calibration fluids. A procedure for choosing calibration fluids, temperatures, and pressures for the calibration points is developed. The densimeters are thoroughly tested with a variety of gases and liquids to show the validity of the equation over the calibration range. Finally, the magnitude of the temperature and pressure corrections are shown using propane + i-butane as a test system. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Holcomb, CD (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 21 TC 27 Z9 27 U1 1 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 SEP PY 1998 VL 150 BP 815 EP 827 DI 10.1016/S0378-3812(98)00362-8 PG 13 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300087 ER PT J AU Graham, BF Lagalante, AF Bruno, TJ Harrowfield, JM Trengove, RD AF Graham, BF Lagalante, AF Bruno, TJ Harrowfield, JM Trengove, RD TI Solubility of p-t-butylcalixarenes in supercritical carbon dioxide: a comparison of static and dynamic measurement techniques SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE carbon dioxide; p-t-butylcalixarenes; solid-fluid equilibria; spectroscopy; supercritical ID FLUIDS; CALIXARENES; CO2 AB The solubilities of p-t-butylcalix[n]arenes (n = 4,6,8) and calix[4]arene have been measured in supercritical carbon dioxide. Solubility measurements were conducted in a high pressure cell with in situ spectrophotometric detection. Measurements were taken over the ranges of 10 to 20 MPa and 40 to 60 degrees C. The p-t-butylcalix[il]arene showed solubility approximately 10 fold higher than both p-t-butylcalix[6]arene and p-t-butylcalix[8]arene with a maximum measured solubility over the studied pressure and temperature ranges of 1.84 x 10(-5) mol/l. A comparison of these results with measurements made with a commercially available analytical SFE unit for p-t-butylcalix[4]arene showed less than 10% deviation between the two sets of data over a common range of conditions. The SFE unit allows measurements to be made over significantly wider ranges of pressure and temperature than are currently available using the solubility cell. Published by Elsevier Science B.V. C1 Univ Western Australia, Special Res Ctr Adv Mineral & Mat Proc, Dept Chem, Nedlands, WA 6907, Australia. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Trengove, RD (reprint author), Univ Western Australia, Special Res Ctr Adv Mineral & Mat Proc, Dept Chem, Stirling Hwy, Nedlands, WA 6907, Australia. RI Graham, Brendan/C-2399-2013 NR 17 TC 16 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD SEP PY 1998 VL 150 BP 829 EP 838 DI 10.1016/S0378-3812(98)00363-X PG 10 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 134LV UT WOS:000076745300088 ER PT J AU Nishimura, A Tobler, RL Tamura, H Imagawa, S Yamamoto, J AF Nishimura, A Tobler, RL Tamura, H Imagawa, S Yamamoto, J TI Fracture toughness of thick-section weld joint of SUS 316 at cryogenic temperature SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 4th International Symposium on Fusion Nuclear Technology (ISFNT-4) CY APR 06-11, 1997 CL TOKYO, JAPAN ID LARGE HELICAL DEVICE AB A large superconducting magnet system for a fusion device requires large support structures which must have enough stiffness and toughness in cryogenic service. In the large helical device (LHD), an austenitic stainless steel SUS 316 with a thickness of up to 100 mm has been used for a supporting shell, shell arms and helical coil covers. Since these structures are assembled by welding, fracture toughness of the thick-section weld joint of SUS 316 has been investigated at cryogenic temperature using a large bend bar with a cross-section 87.5 x 175 mm. In three tests, unstable fracture (large pop-ins) occurred at maximum load. The toughness at the first large pop-in showed a higher resistance to crack initiation than that obtained in a conventional compact tension specimen, however, the crack propagated rapidly and no stable tearing was observed. When a linear elastic failure concept is employed to estimate the critical section thickness, it is confirmed that the LHD cryogenic structures have enough safety margin to resist linear elastic breaks. Published by Elsevier Science S.A. All rights reserved. C1 Natl Inst Fus Sci, Gifu 50952, Japan. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Nishimura, A (reprint author), Natl Inst Fus Sci, 322-6 Oroshi, Gifu 50952, Japan. RI Tamura, Hitoshi/E-7919-2013 NR 9 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 1998 VL 42 BP 425 EP 430 DI 10.1016/S0920-3796(98)00104-5 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 136BZ UT WOS:000076839200055 ER PT J AU Gao, RS Karcher, B Keim, ER Fahey, DW AF Gao, RS Karcher, B Keim, ER Fahey, DW TI Constraining the heterogeneous loss of O-3 on soot particles with observations in jet engine exhaust plumes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER STRATOSPHERE; AIRCRAFT; OZONE; EMISSION AB In situ measurements in the engine exhaust of a Concorde supersonic aircraft in the lower stratosphere are used to constrain heterogeneous reaction rates on soot particles in a plume model. Upper limit values are obtained for the product of the reactive uptake coefficients of O-3 and NO2 and the mean surface area of individual soot particles using the model and the well-established O-3-N2O correlation in the lower stratosphere. The low reactivity value obtained for O-3 implies that soot reactions cannot account for ozone trends in the lower stratosphere. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. DLR Oberpfaffenhofen, Inst Phys Atmosphare, Oberpfaffenhofen, Germany. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Gao, RS (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Karcher, Bernd/D-5325-2014; Fahey, David/G-4499-2013; Gao, Ru-Shan/H-7455-2013 OI Karcher, Bernd/0000-0003-0278-4980; Fahey, David/0000-0003-1720-0634; NR 17 TC 19 Z9 20 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1998 VL 25 IS 17 BP 3323 EP 3326 DI 10.1029/98GL02505 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 116TC UT WOS:000075739800030 ER PT J AU Dai, A Trenberth, KE Karl, TR AF Dai, A Trenberth, KE Karl, TR TI Global variations in droughts and wet spells: 1900-1995 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN-ATMOSPHERE MODEL; EL-NINO; SOUTHERN OSCILLATION; CLIMATE-CHANGE; CO2; TEMPERATURE; RAINFALL; PACIFIC; TRENDS; ENSO AB The Palmer Drought Severity Index (PDSI) was calculated globally using gridded monthly air temperature and precipitation. From 1900 to 1995, there are large multiyear to decadal variations in the percentage areas in severe drought (PDSI < -3.0) and severe moisture surplus (PDSI > +3.0) over many land areas while secular trends are small. Since the late 1970s, however, there have been some increases in the combined percentage areas in severe drought and severe moisture surplus, resulting from increases in either the drought area (e.g., over the Sahel, eastern Asia and southern Africa) or both the drought and wet areas (e.g., over the U.S. and Europe). Although the high percentages of the dry and wet areas in the recent decades are not unprecedented during this century (except the Sahel), the recent changes are closely relate to the shift in El Nino - Southern Oscillation (ENSO) towards more warm events since the late 1970s and coincide with record high global mean temperatures. Moreover, for any given Value of ENSO indices, the PDSI anomalies tend to be larger than would be expected from previous records. These changes are qualitatively consistent with those expected from increased greenhouse gases in the atmosphere. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Dai, A (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM adai@ucar.edu; trenbert@ucar.edu; tkarl@ncdc.noaa.gov RI Trenberth, Kevin/A-5683-2012; Dai, Aiguo/D-3487-2009 OI Trenberth, Kevin/0000-0002-1445-1000; NR 25 TC 232 Z9 278 U1 4 U2 49 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1998 VL 25 IS 17 BP 3367 EP 3370 DI 10.1029/98GL52511 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 116TC UT WOS:000075739800041 ER PT J AU Bakwin, PS Tans, PP White, JWC Andres, RJ AF Bakwin, PS Tans, PP White, JWC Andres, RJ TI Determination of the isotopic (C-13/C-12) discrimination by terrestrial biology from a global network of observations SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID NORTHERN-HEMISPHERE; ATMOSPHERIC CO2; CARBON-DIOXIDE; RATIO; C-13; AIR AB We analyze data from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory global air sampling network in order to extract the signatures of isotopic (C-13/C-12) discrimination by the terrestrial biota and of fossil fuel combustion for the regions surrounding the sampling sites. We utilize measurements of carbon monoxide (CO) to give an estimate of the contribution of fossil fuel combustion to the short-term variability of carbon dioxide (CO2). In general, variations of CO2 are more strongly dominated by biological exchange, so the isotopic signature of fossil fuel combustion, while consistent with inventory estimates, is not well constrained by the observations. Conversely, results for isotope discrimination by the terrestrial biosphere are not strongly dependent on assumptions about fossil fuel combustion. Our analysis appears valid primarily for stations fairly near continental source/sink regions, particularly for midlatitude regions of the northern hemisphere. For these stations we derive a mean discrimination of -16.8 per mil (%), with site-to-site variability of 0.8% (1 standard deviation) and with little or no consistent latitudinal gradient. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Alaska, Inst No Engn, Fairbanks, AK 99775 USA. Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA. RP Bakwin, PS (reprint author), NOAA, Climate Monitoring & Diagnost Lab, R-E-CG1,325 Broadway, Boulder, CO 80303 USA. EM pbakwin@cmdl.noaa.gov; ptans@cmdl.noaa.gov; jwhite@spot.colorado.edu; an-dres@arsc.edu RI White, James/A-7845-2009; ANDRES, ROBERT/B-9786-2012 OI White, James/0000-0001-6041-4684; NR 29 TC 77 Z9 83 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP PY 1998 VL 12 IS 3 BP 555 EP 562 DI 10.1029/98GB02265 PG 8 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 115DY UT WOS:000075649300011 ER PT J AU Blackburn, DL Courtois, B AF Blackburn, DL Courtois, B TI Foreword - Thermal investigations of IC's and microstructures (THERMINIC) SO IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART A LA English DT Editorial Material C1 NIST, Gaithersburg, MD 20899 USA. TIMA Lab, F-38031 Grenoble, France. RP Blackburn, DL (reprint author), NIST, Gaithersburg, MD 20899 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 USA SN 1070-9886 J9 IEEE T COMPON PACK A JI IEEE Trans Compon. Packag. Manuf. Technol. Part A PD SEP PY 1998 VL 21 IS 3 BP 397 EP 398 PG 2 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 128QC UT WOS:000076416500001 ER PT J AU Armstrong, AA Huff, LC Glang, GF AF Armstrong, AA Huff, LC Glang, GF TI New technology for shallow water hydrographic surveys SO INTERNATIONAL HYDROGRAPHIC REVIEW LA English DT Article AB The United States Office of Coast Survey is developing technology for shallow water hydrographic surveys in order to increase the efficiency with which hydrographic data are acquired and to improve the likelihood that all potential dangers to navigation are detected in the course of a hydrographic survey. Three areas of technology hold the greatest promise for meeting those goals: Airborne Lidar Hydrography (ALH), Shallow Water Multibeam Sonars (SWMB), and digital side scan sonar, especially the Coast Survey's new High Speed, High Resolution Side Scan Sonar (HSHRSSS). The Coast Survey expects that all its ALH surveys will be outsourced to private sector contractors, and that its SWMB and side scan sonar surveys will be accomplished by both NOAA survey vessels and by private sector contractors. This diversity of sources for survey data influences the strategy for managing these new technologies. C1 NOAA, Off Coast Survey, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Armstrong, AA (reprint author), NOAA, Off Coast Survey, Natl Ocean Serv, Silver Spring, MD 20910 USA. NR 2 TC 1 Z9 1 U1 3 U2 3 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 SEP PY 1998 VL 75 IS 2 BP 27 EP 41 PG 15 WC Engineering, Marine; Oceanography; Water Resources SC Engineering; Oceanography; Water Resources GA 140NK UT WOS:000077093800003 ER PT J AU Mills, GB AF Mills, GB TI International hydrographic survey standards SO INTERNATIONAL HYDROGRAPHIC REVIEW LA English DT Article C1 NOAA, Off Coast Survey, Hydrograph Surveys Div, Silver Spring, MD 20910 USA. RP Mills, GB (reprint author), NOAA, Off Coast Survey, Hydrograph Surveys Div, 1315 East West Highway,Stn 6859, Silver Spring, MD 20910 USA. NR 2 TC 7 Z9 7 U1 0 U2 0 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 SEP PY 1998 VL 75 IS 2 BP 79 EP 85 PG 7 WC Engineering, Marine; Oceanography; Water Resources SC Engineering; Oceanography; Water Resources GA 140NK UT WOS:000077093800006 ER PT J AU Parker, BB Huff, LC AF Parker, BB Huff, LC TI Modern under-keel clearance management SO INTERNATIONAL HYDROGRAPHIC REVIEW LA English DT Article ID SYSTEM AB This paper provides an overview of recent technological developments that have improved the ability to manage under-keel clearance (UKC) in ports. The inaccurate determination of the UKC of large-draft ships entering or leaving depth-limited ports can have serious safety, economic, and environmental consequences. A ship's master can manage his ship's UKC by: (I) taking actions that affect the ship's dynamic draft (such as changing the ship's speed) and (2) scheduling his ship's transit of the planned route to ensure that there will be sufficient water level for safe passage when the ship reaches locations with controlling depths. To do this, however, he must have accurate real-time and forecast environmental information along his route, as well as a validated method of predicting his ship's motion (and thus dynamic draft) for various situations. At a minimum, this information must include accurate charted depths and underwater hazards, water revels, and ship-specific channel-specific prediction formulas for dynamic draft (based on ship speed, static draft, and water depth). The dynamic draft calculation may also require information on currents, water density, and waves, swell, and/or seiching. Recently developed systems that can provide the necessary information for UKC management include. nowcast/forecast oceanographic model systems (a necessary step beyond real-time oceanographic systems); on-the-fly GPS systems to provide accurate ship motion data for calibrating dynamic-draft prediction systems; modern hydrographic measurement systems (such as shallow-water multibeam and side-scan sonar systems); and modern electronic nautical chart systems (and their supporting rapid update services). This paper includes discussion of what further improvements to these systems are needed to make effective UKC management a reality. C1 NOAA, Coast Survey Dev Lab, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Parker, BB (reprint author), NOAA, Coast Survey Dev Lab, Natl Ocean Serv, Silver Spring, MD 20910 USA. NR 30 TC 5 Z9 5 U1 1 U2 2 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 SEP PY 1998 VL 75 IS 2 BP 143 EP 165 PG 23 WC Engineering, Marine; Oceanography; Water Resources SC Engineering; Oceanography; Water Resources GA 140NK UT WOS:000077093800011 ER PT J AU Tsang, W Lifshitz, A AF Tsang, W Lifshitz, A TI Kinetic Stability of 1,1,1-trifluoroethane SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID THERMAL-DECOMPOSITION AB 1,1,1-Trifluoroethane has been decomposed in comparative rate single-pulse shock-tube experiments. The rate expression For elimination at ca. 2.5 bar and in the temperature range of 1050 to 1200 K has been found to be k(CF3-CH3-->HF+CF2=CH2) = 7.0x1014 exp(-37260/T)s-1 The experimental conditions appear to be such that the unimolecular reaction is at the beginning of the fall-off region and we End that for step sizes down between 500 and 1000 cm(-1) the high-pressure rate expression is in the range k(CF3-CH3-->HF+CF2=CH2) = 2.0x105 exp(-38300/T) to 4x1015 exp(-39000/T)s-1 where the smaller rate parameters refer to the larger step size down. The results are compared with those from an earlier study and the anomalously high A-factor is noted. It is suggested that the existing rate expressions for the fluorinated ethanes may need to be reevaluated. (C) 1998 John Wiley C Sons, Inc., int J Chem Kinet: 30: 621-628, 1998. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Hebrew Univ Jerusalem, IL-91904 Jerusalem, Israel. RP Tsang, W (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 22 TC 33 Z9 33 U1 0 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD SEP PY 1998 VL 30 IS 9 BP 621 EP 628 DI 10.1002/(SICI)1097-4601(1998)30:9<621::AID-KIN3>3.3.CO;2-7 PG 8 WC Chemistry, Physical SC Chemistry GA 111FW UT WOS:000075427500003 ER PT J AU Peterson, TC Vose, R Schmoyer, R Razuvaev, V AF Peterson, TC Vose, R Schmoyer, R Razuvaev, V TI Global historical climatology network (GHCN) quality control of monthly temperature data SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE global historical climatology network (GHCN); quality control; temperature; monthly; homogeneity tests; outliers ID SERIES AB All geophysical data bases need some form of quality assurance. Otherwise, erroneous data points may produce faulty analyses. However, simplistic quality control procedures have been known to contribute to erroneous conclusions by removing valid data points that were more extreme than the data set compilers expected. In producing version 2 of the global historical climatology network's (GHCN's) temperature data sets, a variety of quality control tests were evaluated and a specialized suite of procedures was developed. Quality control traditionally relies primarily on checks for outliers from both a time series and spatial perspective, the latter accomplished by comparisons with neighbouring stations. This traditional approach was used, and it was determined that there are many data problems that require additional tests to detect. In this paper a suite of quality control tests are justified and documented and applied to this global temperature data base, emphasizing the logic and limitations of each test. (C) 1998 Royal Meteorological Society. C1 NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. Arizona State Univ, Tempe, AZ 85287 USA. DOE, Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Res Inst Hydrometeorol Informat, Obninsk, Russia. RP Peterson, TC (reprint author), NOAA, Natl Climat Data Ctr, 151 Patton Ave,Room 120, Asheville, NC 28801 USA. EM tpeterso@ncdc.noaa.gov NR 21 TC 126 Z9 140 U1 2 U2 12 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD SEP PY 1998 VL 18 IS 11 BP 1169 EP 1179 DI 10.1002/(SICI)1097-0088(199809)18:11<1169::AID-JOC309>3.0.CO;2-U PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 122XV UT WOS:000076097500001 ER PT J AU Hamelin, J Mehl, JB Moldover, MR AF Hamelin, J Mehl, JB Moldover, MR TI The static dielectric constant of liquid water between 274 and 418 K near the saturated vapor pressure SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE cyclohexane; dielectric constant; re-entrant radio-frequency resonator; relative permittivity; static dielectric constant; water ID TEMPERATURES; PERMITTIVITY; STEAM; MPA AB The complex dielectric constant (relative electric permittivity) epsilon(r) = epsilon' - i epsilon " of liquid water was redetermined in the temperature range 0 degrees C < t < 145 degrees C at pressures less than 440 kPa. In this work, epsilon(r) was deduced from measurements of the resonant frequencies f(alpha) of a novel, re-entrant, two-mode, radio-frequency resonator. The frequencies ranged from 23 to 84 MHz and were well within the low-frequency limit for epsilon' because (2 pi f(alpha)tau(max))(2) < 5 x 10(-5) where tau(max) = 1.8 x 10(-11) s is the maximum relaxation time of water under the conditions studied. The data for epsilon' for two water samples differing in conductivity by a factor of 3.6 and for the two resonant modes differing in frequency by a factor of 2.6 were simultaneously fit by the polynomial function epsilon'(t) = 87.9144-0.404399t+9.58726 x 10(-4)t(2)-1.32802 x 10(-6)t(3) With a remarkably small residual standard deviation of 0.0055. The present data are consistent with previously published data; however, they are more precise and internally consistent. The present apparatus was also tested with cyclohexane and yielded the values epsilon'(t) = 2.0551 - 0.00156t for 20 degrees C <1< 30 degrees C, in excellent agreement with previously published values. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Univ Delaware, Dept Phys, Newark, DE 19716 USA. RP Moldover, MR (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 29 TC 16 Z9 17 U1 1 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 1998 VL 19 IS 5 BP 1359 EP 1380 DI 10.1023/A:1021979401680 PG 22 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 153PT UT WOS:000077842000006 ER PT J AU Magee, JW AF Magee, JW TI Isochoric p-rho-T measurements on 1,1-difluoroethane (R152a) from 158 to 400 K and 1,1,1-trifluoroethane (R143a) from 166 to 400 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE density; 1,1-difluoroethane; p-rho-T data; R143a; R152a; saturated liquid; 1,1,1-trifluoroethane ID SATURATED LIQUID DENSITIES; VAPOR-PRESSURES; 1,1,1,2-TETRAFLUOROETHANE R-134A; GAS-PHASE; R-152A; P,RHO,T; STATE AB The p-rho-T relationships have been measured for 1,1-difluoroethane (R152a) and 1,1,1-trifluoroethane (R143a) by an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged from 158 to 400 K for R152a and from 166 to 400 K for R143a, while pressures were up to 35 MPa. Measurements were conducted on compressed liquid samples. Determinations of saturated liquid densities were made by extrapolating each isochore to the vapor pressure, and determining the temperature and density at the intersection. Published p-rho-T data are in good agreement with this study. For the p-rho-T apparatus, the uncertainty of the temperature is +/- 0.03 K, and for pressure it is +/-0.01% at p > 3 MPa and +/-0.05% at p < 3 MPa. The principal source of uncertainty is the cell volume (similar to 28.5 cm(3)), which has a standard uncertainty of +/-0.003 cm(3). When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor k=2 and thus a two-standard deviation estimate) of the density measurements is estimated to be +/-0.05%. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, 325 Broadway, Boulder, CO 80303 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 19 TC 6 Z9 6 U1 1 U2 6 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 1998 VL 19 IS 5 BP 1381 EP 1395 DI 10.1023/A:1021931518519 PG 15 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 153PT UT WOS:000077842000007 ER PT J AU Magee, JW AF Magee, JW TI Molar heat capacity at constant volume of 1,1-difluoroethane (R152a) and 1,1,1-trifluoroethane (R143a) from the triple-point temperature to 345 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE 1,1-difluoroethane; enthalpy of fusion; heat capacity; 1,1,1-trifluoroethane; triple point; R143a; R152a; vapor pressure ID LIQUID; STATE AB Molar heat capacities at constant volume (C-v) of 1,1-difluoroethane (R152a) and 1,1,1-trifluoroethane (R143a) have been measured with an adiabatic calorimeter. Temperatures ranged from their triple points to 345 K, and pressures up to 35 MPa. Measurements were conducted on the liquid in equilibrium with its vapor and on compressed liquid samples. The samples were of high purity, verified by chemical analysis of each fluid. For the samples, calorimetric results were obtained for two-phase (C-v((2))), saturated-liquid (C-sigma or C-x'), and single-phase (C-v) molar heat capacities. The C-sigma data were used to estimate vapor pressures for values less than 105 kPa by applying a thermodynamic relationship between the saturated liquid heat capacity and the temperature derivatives of the vapor pressure. The triple-point temperature and the enthalpy of fusion were also measured for each substance. The principal sources of uncertainty are the temperature rise measurement and the change-of-volume work adjustment. The expanded relative uncertainty (with a coverage factor k = 2 and thus a two-standard deviation estimate) for C-v is estimated to be 0.7%, for C-v((2)) it is 0.5%, and for C-sigma it is 0.7%. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, Boulder, CO 80303 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, 325 Broadway, Boulder, CO 80303 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 14 TC 18 Z9 18 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 1998 VL 19 IS 5 BP 1397 EP 1420 DI 10.1023/A:1021983502589 PG 24 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 153PT UT WOS:000077842000008 ER PT J AU Basist, A Grody, NC Peterson, TC Williams, CN AF Basist, A Grody, NC Peterson, TC Williams, CN TI Using the special sensor microwave/imager to monitor land surface temperatures, wetness, and snow cover SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SSM/I MEASUREMENTS; BRIGHTNESS TEMPERATURES; INTERPOLATION; TRENDS; MODEL AB The worldwide network of in situ land surface temperatures archived in near-real time at the National Climatic Data Center (NCDC) has limited applications, since many areas are poorly represented or provide no observations. Satellite measurements offer a possible way to fill in the data voids and obtain a complete map of surface temperature over the entire globe. A method has been developed to calculate near-surface temperature using measurements from the Special Sensor Microwave/Imager (SSM/I). To accomplish this, the authors identify numerous surface types and make dynamic adjustments for Variations in emissivity. Training datasets were used to define the relationship between the seven SSM/I channels and the near-surface temperature. For instance, liquid water on the surface reduces emissivity; therefore, the authors developed an adjustment to correct for this reduction. Other surface types (e.g., snow, ice, and deserts) as well as precipitation are identified, and numerous adjustments and/or filters were developed for these features. The article presents the results obtained from training datasets, as well as an independent case study, containing extreme conditions for deriving temperature from the SSM/I. The U.S. networks of first-order and cooperative stations, quality controlled by NCDC, serve as validation data. The correlation between satellite-derived and in situ temperatures during the independent case ("Blizzard of 1996") was greater than 0.95, and the standard error was 2 degrees C, The authors also present SSM/I-derived snow cover and wetness maps from this 2-week period of the blizzard. A prototype for blending the satellite and in situ measurements into a single land surface temperature product is also presented. C1 Natl Ocean & Atmospher Adm, Natl Environm Satellite Data & Informat Serv, Natl Climat Data Ctr, Global Climate Lab, Asheville, NC 28801 USA. Natl Ocean & Atmospher Adm, Natl Environm Satellite Data & Informat Serv, Off Res & Appl, Camp Springs, MD USA. RP Basist, A (reprint author), Natl Ocean & Atmospher Adm, Natl Environm Satellite Data & Informat Serv, Natl Climat Data Ctr, Global Climate Lab, Room 120,151 Patton Ave, Asheville, NC 28801 USA. EM abasist@ncdc.noaa.gov NR 37 TC 94 Z9 105 U1 1 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 1998 VL 37 IS 9 BP 888 EP 911 DI 10.1175/1520-0450(1998)037<0888:UTSSMI>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115ZP UT WOS:000075696700003 ER PT J AU Cooper, HJ Smith, EA Rubes, MT AF Cooper, HJ Smith, EA Rubes, MT TI Relevance of surface energy budget within Florida sea-breeze front to cross-peninsula rainwater runoff gradient SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MICROPHYSICAL EVOLUTION; SOUTH FLORIDA; CUMULONIMBUS; DIVERGENCE; LAND; PRECIPITATION; SENSITIVITY; CYCLE AB Analysis of surface latent hear flux measurements taken within the sea-breeze front of the coast of Florida during active thunderstorm periods demonstrates an important effect of the timing of coastal storms on the seasonal surface water budget. Historical records document a systematic cross-peninsula water runoff gradient across Florida, with total runoff greater on the east coast (Atlantic side) than on the west coast (gulf side). This situation persists even though convective rainfall tends to be greater in the summertime on the gulf side. Ln this paper, the authors examine the effect of the time of day that summer thunderstorms occur at a given location on poststorm evaporation of rainfall and place these effects into the context of the annual runoff at the coasts and seasonal rainfall in order to assess their possible significance; A surface water exchange analysis, based on datasets obtained during the 1991 summertime Convection and Precipitation Electrification Experiment, finds that part of the runoff gradient can be explained by an indirect atmospheric mechanism. Results indicate that differences in the diurnal timing of thunderstorms between the two coasts and the associated differences in postthunderstorm evapotranspiration can account for a significant portion of the annual differential in runoff. During the summer months, gulf coast storms often occur earlier in the day than Atlantic coast storms because of the combined effects of the mesoscale sea-breeze convergence and synoptic-scale flow around the Bermuda high. Under these conditions, once the later-day east coast thunderstorms dissipate, there is no longer any net solar radiation source to drive evapotranspiration, so that rainwater not taken up by ground filtration tends to go into runoff. On the west coast, when thunderstorms occur earlier and dissipate in midafternoon, there is still enough net surface radiation to drive significant rates of evapotranspiration, which reduces the amount of water available for runoff. The difference in available rainfall that results from the increased evaporation after the earlier storms is found to be about 2 mm, which over the summer season amounts to some 50 mm of water not made available for runoff on the west coast. This is significant; when compared to the annual cross-peninsula runoff gradient of 250 mm. It is also found that it rakes 4.5 days of clear-sky latent heat fluxes to reevaporate average storm rainfall back into the atmosphere. In addition, areas that are not dose to the center of storm outflows tend to be neutral in terms of daily surface water exchange, evaporating as much as they receive, while cloudy areas with no rain evaporate at rates close to 90% of the clear-sky rates on a daily basis. This paper addresses the details of these processes and quantifies the surface water exchange in south Florida as a function of the proximity to the summertime thunderstorm outflows. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. NOAA, ARL, Surface Radiat Res Branch, Boulder, CO 80303 USA. RP Smith, EA (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NR 29 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 1998 VL 37 IS 9 BP 939 EP 950 DI 10.1175/1520-0450(1998)037<0939:ROSEBW>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115ZP UT WOS:000075696700006 ER PT J AU Tewari, YB AF Tewari, YB TI Thermodynamics of the lipase-catalyzed esterification of 1-dodecanoic acid and 1-dodecanol in organic solvents SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID SURFACTANT-COATED LIPASE; EQUILIBRIUM POSITION; MEDIA; HYDROLYSIS; SYSTEMS; ESTER; WATER AB Lipase immobilized on controlled-pore glass beads was used to catalyze the esterification of 1-dodecanol and 1-dodecanoic acid in organic solvents. Equilibrium measurements were performed in hexane, heptane, cyclohexane, 2,2,4-trimethylpentane, and toluene at the temperature T = 298.15 K. The equilibrium constants correlate well with the (octanol + water) partition coefficients and the dielectric constants of the solvents. The saturation molalities and the (2,2,4-trimethylpentane + water) partition coefficients of 1-dodecanol, 1-dodecanoic acid, and dodecyl dodecanoate have been determined at T = 298.15 K. The equilibrium constant of the esterification reaction in water has also been calculated. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Tewari, YB (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 18 TC 13 Z9 13 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 1998 VL 43 IS 5 BP 750 EP 755 DI 10.1021/je980021x PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 119JQ UT WOS:000075892900015 ER PT J AU Archer, DG Rard, JA AF Archer, DG Rard, JA TI Isopiestic investigation of the osmotic and activity coefficients of aqueous MgSO4 and the solubility of MgSO4 center dot 7H(2)O(cr) at 298.15 K: Thermodynamic properties of the MgSO4+H2O system to 440 K SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID TEMPERATURE T=298.15 K; MAGNESIUM-SULFATE; ELEVATED-TEMPERATURES; HEAT-CAPACITIES; NACL+H2O SYSTEM; 25-DEGREES-C; CHLORIDE; VOLUMES; NA2SO4; MGCL2 AB Isopiestic determinations of the osmotic coefficient of MgSO4(aq) against NaCl(aq) and KCl(aq) reference standards were performed with long equilibration times ranging to 98 days. A value of the 298.15 K solubility of epsomite, MgSO4. 7H(2)O(cr), was also determined. The new measurements were combined with previous thermodynamic measurements to determine the thermodynamic properties of the MgSO4 + H2O system from the ice-freezing line to 440 K. The thermodynamic measurements were fitted with two different models, an ion-interaction model and a chemical-equilibrium model. The ability of the two models to represent this system was examined. C1 NIST, Phys & Chem Propert Div, Gaithersburg, MD 20899 USA. Univ Calif Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94550 USA. RP Archer, DG (reprint author), NIST, Phys & Chem Propert Div, Gaithersburg, MD 20899 USA. NR 80 TC 63 Z9 63 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 1998 VL 43 IS 5 BP 791 EP 806 DI 10.1021/je980047o PG 16 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 119JQ UT WOS:000075892900023 ER PT J AU Goodwin, ARH Defibaugh, DR Weber, LA AF Goodwin, ARH Defibaugh, DR Weber, LA TI Vapor pressure of 2-(difluoromethoxy)-1,1,1-trifluoroethane CHF2-O-CH2CF3 (HFE-245) SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID EBULLIOMETRIC MEASUREMENT; 1,1-DIFLUOROETHANE; R141B; R123 AB The vapor pressure of 2-(difluoromethoxy)-1,1,1-trifluoroethane, a candidate alternative refrigerant that is also known as HFE-245, has been measured. The vapor pressure was determined at temperatures between 261 K and 369 K by two ebulliometric techniques. The differences in these two methods arise from the method used to determine pressure. Atp < 200 kPa, a comparative instrument was used and pressures were obtained from the temperature at which water boiled at the same pressure. At pressures up to 747 kPa, the pressures were measured directly. A correlation for the vapor pressure from 261 K to the critical temperature is provided. The comparative ebulliometric measurements have an expanded uncertainty (k = 2) of less than 0.0005.p, while the direct ebulliometric measurements have an expanded uncertainty (k = 2) of 0.002.p. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Goodwin, ARH (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 13 TC 8 Z9 8 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 1998 VL 43 IS 5 BP 846 EP 848 DI 10.1021/je980056x PG 3 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 119JQ UT WOS:000075892900033 ER PT J AU Ropelewski, CF Yarosh, ES AF Ropelewski, CF Yarosh, ES TI The observed mean annual cycle of moisture budgets over the central United States (1973-92) SO JOURNAL OF CLIMATE LA English DT Article ID ETA-MODEL AB The mean annual cycle of the atmospheric and terrestrial water balance over the central United States is examined through an analysis of observational data over the 20-yr period 1973-92. The mean quantifies from this study are expected to serve as a climatology for empirical investigations and a benchmark for numerical model-based water balance computations for the central United States. Monthly means and statistics of atmospheric water balance quantities were computed from twice daily radiosonde data. These data form a monthly "climatology" and 240 month time series of the major water budget components, including the vertically integrated vapor flux divergence, the rate of change of precipitable water, and precipitation minus evapotranspiration, P - E. The mean annual cycle of evaporation given estimates of precipitation over the same area is also computed. Through comparison with observed river discharge, estimates' are formed of: the mean annual cycle of surface and subsurface storage and its interannual variability (as a residual). The mean observed and residual quantities of the historical water budget components are in general agreement with earlier studies based on shorter time series. The 20-yr mean water budget shows a maximum of P- E in March-April with a secondary maximum in November-December. In this analysis, mean evaporation exceeds mean precipitation during the June-September period with largest evaporation values in July and-August. Thus, the heartland of-the United States acts as mean net moisture source during the summer months. Individual monthly estimates of evaporation, given the gauge-estimated precipitation over the region, show negative evaporation estimates during some Cold season months over the 1973-92 period. This suggests that gauge-measured precipitation is underestimated, at least during the cold months, in agreement with several rain gauge intercomparison studies. The sonde-based budgets also confirm previous studies in showing that the rate of change of precipitable water is a small contributor to the atmospheric water budget through most of the mean annual cycle. However, the relative importance of this term increases during the transition seasons (late spring and early fall) when the magnitude of the vapor flux divergence term in the atmospheric water balance is also quite small. The mean P - E estimates computed from the vertically integrated atmospheric moisture flux were found to average 0.4 mm day(-1) low in comparison to the observed total net river discharge. When the mean atmospheric P - E is adjusted to the net discharge, the annual cycle of storage shows an amplitude of 14 cm yr(-1), consistent with local measurements of soil moisture in Illinois (Hollinger and Isard) and also in agreement with earlier studies. The 20-yr time series shows multiyear variations in the storage term with magnitudes of near 45 cm, far in excess of the mean annual cycle. This low-frequency variability in storage is generally consistent with the accumulated precipitation anomaly. an independently estimated quantity, for most of the analysis period. C1 NOAA, Climate Predict Ctr, NCEP NWS, Washington, DC USA. Res & Data Syst Corp, Greenbelt, MD USA. RP Ropelewski, CF (reprint author), IRI, 207 Oceanog,POB 1000,61 Rt 9W, Palisades, NY 10964 USA. NR 26 TC 36 Z9 36 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1998 VL 11 IS 9 BP 2180 EP 2190 DI 10.1175/1520-0442(1998)011<2180:TOMACO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 123YG UT WOS:000076152800002 ER PT J AU Knutson, TR Manabe, S AF Knutson, TR Manabe, S TI Model assessment of decadal variability and trends in the tropical Pacific Ocean SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; NINO-SOUTHERN OSCILLATION; EL-NINO; ATMOSPHERE MODEL; NORTH PACIFIC; WAVE DYNAMICS; CLIMATE VARIABILITY; SULFATE AEROSOLS; COUPLED MODEL; MEAN RESPONSE AB In this report, global coupled ocean-atmosphere models are used to explore possible mechanisms for observed decadal variability and trends in Pacific Ocean SSTs over the past century. The leading mode of internally generated decadal (>7 yr) variability in the model resembles the observed decadal variability in terms of pattern and amplitude. In the model, the pattern and time evolution of tropical winds and oceanic heat content are similar for the decadal and ENSO timescales, suggesting that the decadal variability has a similar "delayed oscillator" mechanism to that on the ENSO timescale. The westward phase propagation of the heal content anomalies, however, is slower and centered slightly farther from the equator (similar to 12 degrees vs 9 degrees N) for the decadal variability. Cool SST anomalies in the midlatitude North Pacific during the warm tropical phase of the decadal variability are induced in the model largely by oceanic advection anomalies. An index of observed SST over a broad triangular region of the tropical and subtropical Pacific indicates a warming rate of +0.41 degrees C (100 yr)(-1) since 1900, +1.2 degrees C (100 yr)(-1) since 1949, and +2.9 degrees C (100 yr)(-1) since 1971. All three warming trends are highly unusual in terms of their duration, with occurrence rates of less than 0.5% in a 2000-yr simulation of internal climate variability using a low-resolution model. The most unusual is the trend since 1900 (96-yr duration): the longest simulated duration of a trend of this magnitude is 85 yr. This suggests that the observed trends are not entirely attributable to natural (internal) variability alone, although natural variability could potentially account for much of the observed trends. To quantitatively explore the possible role of greenhouse gases and aerosols in the observed warming trends, two simulations (using different initial conditions) of twentieth-century climate change due to these two radiative forcings were analyzed. These simulate an accelerated warming trend [similar to 2 degrees C (100 yr)(-1)] in the triangular Pacific region beginning around the 1960s and suggest that nearly all of the recent warming in the region could be attributable to such a thermal forcing. In summary, the authors' model results indicate that the observed warming trend in the eastern tropical Pacific is not likely to be solely attributable to internal (natural) climate variability. Instead, it is likely that a sustained thermal forcing, such as the increase of greenhouse gases in the atmosphere, has been at least partly responsible for the observed warming. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Knutson, TR (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 55 TC 161 Z9 163 U1 4 U2 19 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1998 VL 11 IS 9 BP 2273 EP 2296 DI 10.1175/1520-0442(1998)011<2273:MAODVA>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 123YG UT WOS:000076152800008 ER PT J AU Shen, SS Smith, TM Ropelewski, CF Livezey, RE AF Shen, SS Smith, TM Ropelewski, CF Livezey, RE TI An optimal regional averaging method with error estimates and a test using tropical Pacific SST data SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURES AB This paper provides a systematic procedure for computing the regional average of climate data in a subregion of the earth surface using the covariance function written in terms of empirical orthogonal functions (EOFs). The method is optimal in the sense of minimum mean square error (mse) and ives an mse estimate of the averaging results. The random measurement error is also included in the total mse. Since the EOFs can account for spatial inhomogeneities, the method can be more accurate than those that assume a homogeneous covariance matrix;This study shows how to further improve the accuracy of optimal averaging (OA) by improving the accuracy of the eigenvalues of the covariance function through an extrapolation method. The accuracy of the authors' procedure is tested using cross-validation techniques, which simulate past sampling conditions on the recent, well-sampled tropical Pacific SST and use the EOFs independent to the month being tested. The true sampling error of the cross-validated tests is computed with respect to the 1 degrees X 1 degrees data for various sampling conditions. The theoretical sampling error is computed from the authors' derived formula and compared to the true error from the cross-validation tests. The authors' numerical results show that (i) the extrapolation method can sometimes improve the accuracy of the eigenvalues by 10%, (ii) the optimal averaging consistently yields smaller mse than the arithmetic averaging, and (iii) the theoretical formula for evaluating the OA error gives estimates that compare well with the true error. C1 Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2G1, Canada. Natl Weather Serv, Climate Predict Ctr, NOAA, Camp Springs, MD USA. RP Shen, SS (reprint author), Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2G1, Canada. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 14 TC 16 Z9 19 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1998 VL 11 IS 9 BP 2340 EP 2350 DI 10.1175/1520-0442(1998)011<2340:AORAMW>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 123YG UT WOS:000076152800012 ER PT J AU Mo, KC Higgins, RW AF Mo, KC Higgins, RW TI Tropical convection and precipitation regimes in the western United States SO JOURNAL OF CLIMATE LA English DT Article ID OUTGOING LONGWAVE RADIATION; CIRCULATION ANOMALIES; NORTHERN WINTER; GEOPOTENTIAL HEIGHT; OSCILLATION; HEMISPHERE; RAINFALL; EVENTS AB The authors have documented the relationship:between tropical convection and precipitation regimes in the western United States. Circulation patterns associated with precipitation regimes are described and physical mechanisms are-proposed. Contributions from intraseasonal and interannual bands are examined. When enhanced convection is located in the western Pacific, dry conditions in the Southwest (SW) and wet conditions in the Pacific Northwest (PNW) are observed. Fluctuations in both intraseasonal and interannual bands contribute to the-rainfall variability. Enhanced convection in the western Pacific is accompanied by suppressed convection in the central Pacific. The associated Rossby wave vorticity source (S) anomalies keep the Pacific jet west bf 150 degrees W A westward shift of the storm track to the North Pacific also contributes to dry conditions in the SW and wetness in the PNW. When enhanced tropical convection is located near 150 degrees E, substantial contributions to outgoing longwave radiation anomalies are from fluctuations in the intraseasonal band. A wave train extends from the convective area in the Tropics to North America, where negative 200-hPa streamfunction anomalies are consistent with wetness in California and dry conditions in the PNW. When tropical convection is enhanced in the central Pacific from the date line to 135 degrees W, most contributions are from the interannual band. The positive S anomalies associated with an enhanced local Hadley cell extending from the North Pacific to California are responsible in part for the eastward shift of the subtropical jet. The storm track moves southeast and is consistent with wet conditions in the SW. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Washington, DC 20233 USA. RP Mo, KC (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, W-NP52,4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. NR 26 TC 74 Z9 79 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1998 VL 11 IS 9 BP 2404 EP 2423 DI 10.1175/1520-0442(1998)011<2404:TCAPRI>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 123YG UT WOS:000076152800016 ER PT J AU Elliott, WP Ross, RJ Schwartz, B AF Elliott, WP Ross, RJ Schwartz, B TI Effects on climate records of changes in National Weather Service humidity processing procedures SO JOURNAL OF CLIMATE LA English DT Article ID RADIOSONDE AB The U.S. National Weather Service has recently corrected an error in radiosonde humidity data reduction algorithms, eliminated a sonde thats processing contained another error, and recently made a further change in the humidity data reduction algorithm. They also introduced new procedures for reporting humidity from radiosondes. These changes will affect the climate records of U.S. upper-air humidity. Because the changes affect observations differently at different temperatures and relative humidities, their impact on monthly mean humidity quantities depends on the Frequency with which certain conditions occur. The authors calculated the effects on monthly mean humidity quantities of five specific changes at a representative set of U.S. radiosonde stations. Some of these effects are quite substantial and should be considered in evaluating climate variability. C1 NOAA, Air Resources Lab, Environm Res Labs, Silver Spring, MD 20910 USA. NOAA, Forecast Syst Lab, Environm Res Labs, Boulder, CO USA. RP Elliott, WP (reprint author), OAR REAR, 1325 East West Highway, Silver Spring, MD 20910 USA. NR 9 TC 27 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1998 VL 11 IS 9 BP 2424 EP 2436 DI 10.1175/1520-0442(1998)011<2424:EOCROC>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 123YG UT WOS:000076152800017 ER PT J AU Sadek, F Mohraz, B AF Sadek, F Mohraz, B TI Semiactive control algorithms for structures with variable dampers SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB Semiactive control systems combine the features of active and passive control to reduce the response of structures to various dynamic loadings. They include: (1)Active variable stiffness, where the stiffness of the structure is adjusted to establish a nonresonant condition between the structure and excitation; and (2) active variable damper, where the damping coefficient of the device is varied to achieve the most reduction in the response. This study is concerned with examining the effectiveness of variable dampers for seismic applications. Three algorithms for selecting the damping coefficient of variable dampers are presented and compared. They include a linear quadratic regulator algorithm; a generalized linear quadratic regulator algorithm with a penalty imposed on the acceleration response; and a displacement-acceleration domain algorithm, where the damping coefficient is selected by examining the response on the displacement-acceleration plane and assigning different damping coefficients accordingly. Two-single-degree-of-freedom structures subjected to 20 ground excitations are analyzed using the three algorithms. The analyses indicate that, unlike passive dampers (where for flexible structures, an increase in damping coefficient decreases displacement but increases the acceleration response), variable dampers can be effective in reducing both the displacement and acceleration responses. The algorithms are used to compute the seismic response of two structures: (1) An isolated bridge modeled as a single-degree-of-freedom system; and (2) a base-isolated six-story frame modeled as a multi-degree-of-freedom system. The results indicate that variable dampers significantly reduce the displacement and acceleration responses. C1 So Methodist Univ, Dallas, TX 75275 USA. RP Sadek, F (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 62 Z9 68 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD SEP PY 1998 VL 124 IS 9 BP 981 EP 990 DI 10.1061/(ASCE)0733-9399(1998)124:9(981) PG 10 WC Engineering, Mechanical SC Engineering GA 110LM UT WOS:000075383100007 ER PT J AU Begg, GA Keenan, CP Sellin, MJ AF Begg, GA Keenan, CP Sellin, MJ TI Genetic variation and stock structure of school mackerel and spotted mackerel in northern Australian waters SO JOURNAL OF FISH BIOLOGY LA English DT Article DE allozyme; age structure; fisheries management ID POPULATION-STRUCTURE; SCOMBEROMORUS; MARINE; TUNA; IDENTIFICATION; SYSTEMATICS; SUBDIVISION; ALLOZYME; FISH AB The total mean sample heterozygosity calculated from eight polymorphic loci was 0.172 (0.047 S.E.) (F-st 0.025) for school mackerel Scomberomorus queenslandicus, and for spotted mackerel S. munroi was 0.110 (0.074 S.E.) (F-st 0.038). There was no evidence of temporal variation for either species as significant genetic differences were not detected between months or year classes within areas. Spatially, school mackerel have a complex stock structure, with stocks being associated with large embayments. In contrast, spotted mackerel appear to comprise a single stock in Australian east coast waters. Both species showed a significant pattern of stock structure between Australian east coast and northern (Arafura Sea) samples. (C) 1998 The Fisheries Society of the British Isles. C1 Univ Queensland, Dept Zool, St Lucia, Qld 4072, Australia. Queensland Dept Primary Ind, So Fisheries Ctr, Deception Bay, Qld 4058, Australia. RP Begg, GA (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 42 TC 15 Z9 15 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD SEP PY 1998 VL 53 IS 3 BP 543 EP 559 DI 10.1006/jfbi.1998.9969 PG 17 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 117GU UT WOS:000075774200006 ER PT J AU Coffey, H AF Coffey, H TI Geomagnetic and solar data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article C1 NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80303 USA. RP Coffey, H (reprint author), NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1998 VL 103 IS A9 BP 20525 EP 20525 DI 10.1029/98JA02382 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118BG UT WOS:000075817300017 ER PT J AU Smith, Z Odstrcil, D Dryer, M AF Smith, Z Odstrcil, D Dryer, M TI A 2.5-dimensional MHD parametric study of interplanetary shock interactions with the heliospheric current sheet heliospheric plasma sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL STREAMER BELT; 1 AU; DISTURBANCES; PROPAGATION; SIMULATION; EARTH AB A study of the interaction of interplanetary shock waves with the heliospheric current sheet/heliospheric plasma sheet (HCS/HPS) and the disturbed flow behind them is made with a 2.5 dimensional MHD code that uses improved computational techniques. The aim is to determine if such interactions for typical shocks can produce sufficiently large changes in the interplanetary plasma and field to be geoeffective. The mutual interaction of the shock waves with the HCS/HPS is examined for several angles between the shock normal and the HCS/HPS. We separate the effects of the HCS from those due to angular distance of observer from the initial shock center. The shocks are initiated at 0.1 AU by a finite-duration increase in initial radial velocity. We examine the transit times of the resultant shocks to 1-AU and their strengths along their peripheries. We also examine the 1-AU signatures of the polar component of the magnetic field, B-theta, in the interplanetary disturbance at and following the leading fast mode MHD shock. Note that B-theta = -B-z. We show the differences that result from the presence of the HCS, both qualitatively and quantitatively. The largest effects occur in B-theta, which reaches its largest excursions within 10 degrees of the edge of the HPS. For the moderate shocks simulated in this study, deflections of the field lines produce values of B-theta between 4 and 5 nT in the presence of a HCS. These values are at the lower end of the range considered necessary for interplanetary events to initiate moderate geomagnetic storms. Further study is required to investigate the nature of input pulses and HCS that would give larger B-theta variations. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Astron Inst, Ondrejov 25165, Czech Republic. RP Smith, Z (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80303 USA. RI xue, yansheng/A-9712-2012 NR 17 TC 17 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1998 VL 103 IS A9 BP 20581 EP 20589 DI 10.1029/98JA01994 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118BG UT WOS:000075817300023 ER PT J AU Grant, WS Bowen, BW AF Grant, WS Bowen, BW TI Shallow population histories in deep evolutionary lineages of marine fishes: Insights from sardines and anchovies and lessons for conservation SO JOURNAL OF HEREDITY LA English DT Article; Proceedings Paper CT AGA Symposium on Conservation and Genetics of Marine Organisms CY JUN 07, 1997 CL UNIV VICTORIA, VICTORIA, CANADA SP Amer Genet Assoc HO UNIV VICTORIA ID COD GADUS-MORHUA; GULF-OF-MEXICO; ROUGHY HOPLOSTETHUS-ATLANTICUS; GENETIC STOCK STRUCTURE; CYTOCHROME-B GENE; MITOCHONDRIAL-DNA DIFFERENTIATION; RESTRICTION-ENZYME ANALYSIS; SOUTHERN AFRICAN HAKES; ICE-CORE RECORD; PACIFIC SARDINE AB Most surveys of mitochondrial DNA (mtDNA) in marine fishes reveal low levels of sequence divergence between haplotypes relative to the differentiation observed between sister taxa, It is unclear whether this pattern is due to rapid lineage sorting accelerated by sweepstakes recruitment, historical bottlenecks in population size, founder events, or natural selection, any of which could retard the accumulation of deep mtDNA lineages. Recent advances in paleoclimate research prompt a reexamination of oceanographic processes as a fundamental influence on genetic diversity; evidence from ice cores and anaerobic marine sediments document strong regime shifts in the world's oceans in concert with periodic climatic changes. These changes in sea surface temperatures, current pathways, upwelling intensities, and retention eddies are likely harbingers of severe fluctuations in population size or regional extinctions, Sardines (Sardina, Sardinops) and anchovies (Engraulis) are used to assess the consequences of such oceanographic processes on marine fish intrageneric gene genealogies. Representatives of these two groups occur in temperate boundary currents on a global scale, and these regional populations are known to fluctuate markedly. Biogeographic and genetic data indicate that Sardinops has persisted for at least 20 million years, yet the mtDNA genealogy for this group coalesces in less than half a million years and points to a recent founding of populations around the rim of the Indian-Pacific Ocean. Phylogeographic analysis of Old World anchovies reveals a Pleistocene dispersal from the Pacific to the Atlantic, almost certainly via southern Africa, followed by a very recent recolonization from Europe to southern Africa. These results demonstrate that regional populations of sardines and anchovies are subject to periodic extinctions and recolonizations, Such climate-associated dynamics may explain the low levels of nucleotide diversity and the shallow coalescence of mtDNA genealogies, If these findings apply generally to marine fishes, management strategies should incorporate the idea that even extremely abundant populations may be relatively fragile on ecological and evolutionary time scales. C1 NOAA, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98115 USA. Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32611 USA. RP Grant, WS (reprint author), NOAA, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98115 USA. EM stew.grant@noaa.gov NR 123 TC 672 Z9 782 U1 8 U2 78 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD SEP-OCT PY 1998 VL 89 IS 5 BP 415 EP 426 DI 10.1093/jhered/89.5.415 PG 12 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 123EQ UT WOS:000076113200005 ER PT J AU Waples, RS AF Waples, RS TI Separating the wheat from the chaff: Patterns of genetic differentiation in high gene flow species SO JOURNAL OF HEREDITY LA English DT Article; Proceedings Paper CT AGA Symposium on Conservation and Genetics of Marine Organisms CY JUN 07, 1997 CL UNIV VICTORIA, VICTORIA, CANADA SP Amer Genet Assoc HO UNIV VICTORIA ID EFFECTIVE POPULATION-SIZE; COD GADUS-MORHUA; MITOCHONDRIAL-DNA; F-STATISTICS; CONSERVATION GENETICS; TEMPORAL VARIATION; PACIFIC SALMON; ATLANTIC; FISHES; MARINE AB in many marine species, high levels of gene flow ensure that the genetic signal from population differentiation is weak, As a consequence, various errors associated with estimating population genetic parameters that might normally be safely ignored assume a relatively greater importance. This fact has important implications for the use of genetic data to address two common questions ire fishery conservation and management: (1) How many stocks of a given species are there? and (2) How much gene flow occurs among stocks? This article discusses strategies to maximize the signal:noise ratio in genetic studies of marine species and suggests a quantitative method to correct for bias due to a common sampling problem. For many marine species, however, genetic methods alone cannot fully resolve these key management questions because the amount of migration necessary to eliminate rarest genetic evidence of stock structure (only a handful of individuals per generation) will generally be inconsequential as a force for rebuilding depleted populations on a time scale of interest to humans, These limitations emphasize the importance of understanding the biology and life history of the target species-first, to guide design of the sampling program, and second, so that additional information can be used to supplement indirect estimates of migration rates based on genetic data. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. RP Waples, RS (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM robin.waples@noaa.gov RI Waples, Robin/K-1126-2016 NR 72 TC 705 Z9 724 U1 7 U2 86 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD SEP-OCT PY 1998 VL 89 IS 5 BP 438 EP 450 DI 10.1093/jhered/89.5.438 PG 13 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 123EQ UT WOS:000076113200007 ER PT J AU VanderHart, DL Campbell, GC AF VanderHart, DL Campbell, GC TI Off-resonance proton decoupling on-resonance and near-resonance - A close look at C-13 CPMAS linewidths in solids for rigid, strongly coupled carbons under CW proton decoupling SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE resolution; C-13; CPMAS; decoupling; methylene; polyethylene ID MODERATE-SUSCEPTIBILITY MATERIALS; NUCLEAR-MAGNETIC-RESONANCE; ANGLE-SPINNING NMR; ROTATING SOLIDS; CHEMICAL-SHIFTS; CROSS-POLARIZATION; STATE NMR; MAS NMR; RESOLUTION; RELAXATION AB Ambient-temperature C-13 linewidth (LW) and transverse relaxation (T-2(C)) data are presented for the natural-abundance crystalline carbons of linear polyethylene (LPE) under CW proton decoupling conditions and magic angle spinning (MAS). This linewidth behavior typifies that seen for rigid methylene carbons whose attached protons are also strongly coupled to other protons. These data are presented for two LPE samples (unoriented, melt-crystallized and uniaxially oriented, extruded) as a function of several parameters including static field (1.4 T < B-0 < 9.4 T), proton decoupling field strength (38 kHz < nu(1)(H) < 90 kHz), MAS frequency (0.5 kHz < nu(r) < 8 kHz) and RF frequency offsets from resonance (-4 kHz < Delta nu(off) < 4 kHz). It is the ubiquitous nature of off-resonance proton irradiation (ORPI) (arising from fixed or rotationally dependent deviations from the true proton resonance condition) which provides the focus for this work. Corresponding contributions, LW(ORPI), to the total LW are treated within the general framework of the effective-field picture of CW decoupling. Then, considering the presence of spin fluctuations characteristic of the strongly-dipolar-coupled protons of LPE, LW(ORPI) can be traced to orbit-dependent T-2(C) contributions to LW. Important dependences demonstrated and discussed include: (1) For "off-resonance" decoupling, there is a quadratic dependence of LW(ORPI) on (Delta nu(off)/nu(1)(H)) and there is a strong dependence of the corresponding parabolic coefficient on nu(r). From the latter dependence, characteristic times for spin fluctuations are also estimated. (2) For "on-resonance" decoupling, LW(ORPI) is proportional to (v(1)(H))(-2) and shows very little sensitivity to v(r). These LW(ORPI) contributions become more important at higher B-0 since the principle reason for ORPI is the chemical shift anisotropy (CSA) of the C-13-bonded protons. The difference in sensitivities of LW(ORPI) to nu(r) for the off-resonance and the on-resonance cases is traced back, respectively, to the scalar property of Delta nu(off) for RF frequency offsets and to the tensorial character of the proton CSA. Contributions from LW(ORPI), possibly much larger than those seen in LPE, can be expected when protons near C-13 nuclei sense any non-scalar, rotor-position-dependent magnetic fields, e.g., (a) local dipolar fields associated with third, magnetic nuclei or (b) perturbing magnetic-susceptibility fields arising from paramagnetic or ferromagnetic inclusions in a sample. By understanding the contributions to LW in LPE, one can forecast much more precisely what the potential benefits will be from new decoupling schemes like the recently reported "two-pulse phase modulation" (TPPM) since TPPM is designed to reduce LW(ORPI). Aside from LW(ORPI) contributions, the experimental LW data cover parameter space where another broadening mechanism, namely, MAS-assisted dipolar fluctuations (MADF), is seen. This mechanism, also recognized by others, creates a T-2(C)-type linewidth contribution which increases rapidly as nu(1)(H) decreases and which additionally has some orbit dependence. If the current trend in C-13 CPMAS is toward higher B-0 and nu(r), the nu(r)-dependent MADF contributions can easily dominate LW relative to the B-0-dependent LW(ORPI) contributions. One can avoid serious MADF broadening; however, the minimum acceptable values of V-1(H) for good decoupling rise rapidly with B-0. Finally, a few LW measurements are made on methyl-alpha-D-glucopyranoside tetraacetate (MGT), a rigid, polycrystalline material containing carbons with 0, 1, 2, and 3 attached protons. The behaviors of the methylene, methine, and methyl carbons at 9.4 T are compared with the behavior of LPE. (C) 1998 Academic Press. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Dupont Co, Cent Res, Wilmington, DE 19880 USA. RP VanderHart, DL (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 39 TC 27 Z9 27 U1 0 U2 8 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD SEP PY 1998 VL 134 IS 1 BP 88 EP 112 DI 10.1006/jmre.1998.1470 PG 25 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 126CP UT WOS:000076275600012 ER PT J AU Robins, LH Lowney, JR Wickenden, DK AF Robins, LH Lowney, JR Wickenden, DK TI Cathodoluminescence, photoluminescence, and optical absorbance spectroscopy of aluminum gallium nitride (AlxGa1-xN) films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; MONTE-CARLO SIMULATION; TEMPERATURE-DEPENDENCE; GAN; SAPPHIRE; DIAMOND; LAYERS; TRANSITIONS; METROLOGY; PARTICLES AB Aluminum gallium nitride (AlxGa1-xN) films, grown by metalorganic chemical vapor deposition on sapphire, were characterized by low-temperature cathodoluminescence (CL) and photoluminescence (PL), and room-temperature optical absorbance. The aluminum fractions are estimated to range from x = 0 to x = 0.444. Most films were silicon-doped. The absorption spectra have a Urbach (exponential) form below the bandgap. The width of the Urbach edge, E-U, increases with Al fraction, x, as E-U = (0.045 + 0.104x) eV. The luminescence (CL or FL) spectra show a relatively narrow band-edge peak and a broad deep-level peak. The full-widths at half-maximum of the band-edge CL peaks (measured at T = 15 K) are remarkably similar to the Urbach absorption widths, EU (measured at T = 300 K). PL spectra were obtained from the top surfaces and the film-substrate interfaces of several films. The interface PL spectra of some films show an extra peak 0.15 eV to 0.45 eV below the bandgap, which is ascribed to structural defects or impurity phases localized near the interface. The energy of the band-edge luminescence peak shifts with excitation mode (CL, top-surface FL, or interface FL). This effect is attributed to the variation of the excitation depth, between the top surface and film-substrate interface, with excitation mode, together with the depth variation of film properties such as residual stress or aluminum fraction. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Robins, LH (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 32 TC 10 Z9 10 U1 3 U2 8 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1998 VL 13 IS 9 BP 2480 EP 2497 DI 10.1557/JMR.1998.0348 PG 18 WC Materials Science, Multidisciplinary SC Materials Science GA 114RA UT WOS:000075621600022 ER PT J AU Clerc, DG AF Clerc, DG TI Mechanical hardness: atomic-level calculations for diamond-like materials SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID ELASTIC-CONSTANTS; BORON-NITRIDE C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Clerc, DG (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, 325 Broadway, Boulder, CO 80303 USA. EM tjclercd@aol.com NR 15 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD SEP 1 PY 1998 VL 17 IS 17 BP 1461 EP 1462 DI 10.1023/A:1026470216952 PG 2 WC Materials Science, Multidisciplinary SC Materials Science GA 183GM UT WOS:000079545900009 ER PT J AU Szykman, S Cagan, J Weisser, P AF Szykman, S Cagan, J Weisser, P TI An integrated approach to optimal three dimensional layout and routing SO JOURNAL OF MECHANICAL DESIGN LA English DT Article AB This paper integrates simulated annealing-based component packing, layout and routing algorithms into a concurrent approach to product layout optimization. The design of a heat pump is presented to compare the integrated method to the previous sequential layout-then-route approach; results show a substantial improvement in route design with more organized component placements. The example is given in detail to provide a test case for future research in this area. C1 Natl Inst Stand & Technol, Engn Design Lab, Mfg Syst Integrat Div, Gaithersburg, MD 20899 USA. RP Szykman, S (reprint author), Natl Inst Stand & Technol, Engn Design Lab, Mfg Syst Integrat Div, Bldg 304,Room 6, Gaithersburg, MD 20899 USA. NR 10 TC 8 Z9 8 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD SEP PY 1998 VL 120 IS 3 BP 510 EP 512 DI 10.1115/1.2829180 PG 3 WC Engineering, Mechanical SC Engineering GA 119WU UT WOS:000075921800020 ER PT J AU Belov, SP Tretyakov, MY Kozin, IN Klisch, E Winnewisser, G Lafferty, WJ Flaud, JM AF Belov, SP Tretyakov, MY Kozin, IN Klisch, E Winnewisser, G Lafferty, WJ Flaud, JM TI High frequency transitions in the rotational spectrum of SO2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SUBMILLIMETER-WAVE SPECTRUM; TERAHERTZ REGION; SPECTROSCOPY AB A large number of rotational transitions of (SO2)-S-32-O-16, (SO2)-S-34-O-16 and (SOO)-S-32-O-18-O-16 have been measured in the mm-, submm-, and terahertz (similar to 1 THz) spectral regions. These data sets have been combined with all previously measured SO2 microwave and selected far infrared data to obtain a highly precise set of ground state rotational constants for these isotopomers. The rotational constants for the three isotopomers are in MHz as follows: [GRAPHICS] Centrifugal distortion constants up to P-10 are included in the fit. A frequency listing of all the data used in the frequency range between about 7 GHz and 1 THz is included. (C) 1998 Academic Press. C1 Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. Inst Phys 1, D-50937 Koln, Germany. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Paris 11, Photophys Mol Lab, F-91405 Orsay, France. RP Belov, SP (reprint author), Russian Acad Sci, Inst Appl Phys, 46 Uljanova St, Nizhnii Novgorod 603600, Russia. NR 17 TC 40 Z9 40 U1 0 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1998 VL 191 IS 1 BP 17 EP 27 DI 10.1006/jmsp.1998.7576 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 116WR UT WOS:000075748500003 ER PT J AU Telles, EM Zink, LR Evenson, KM AF Telles, EM Zink, LR Evenson, KM TI Frequencies of optically pumped sub-Doppler far-infrared laser lines of methanol SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SPECTROSCOPY; TRANSITIONS AB Sub-Doppler signals from the gain curves of four lines of a transversely pumped far-infrared methanol laser were used to stabilize the frequencies of the laser. The frequencies of four of the strongest FIR laser lines (70, 119, 123, and 570 mu m) were measured. Lasers locked to these lines have a frequency reproducibility of a few parts in 10(8) and an uncertainty of less than 30 kHz. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Telles, EM (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1998 VL 191 IS 1 BP 206 EP 208 DI 10.1006/jmsp.1998.7635 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 116WR UT WOS:000075748500023 ER PT J AU Fuchs, PA Clark, AV Lozev, MG Halabe, U Klinkhachorn, P Petro, S GangaRao, H AF Fuchs, PA Clark, AV Lozev, MG Halabe, U Klinkhachorn, P Petro, S GangaRao, H TI Ultrasonic instrumentation for measuring applied stress on bridges SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE ultrasonic; EMAT; applied stress; strain; Rayleigh wave; bridge ID RAINFLOW AB The measurement of applied stress on bridges can provide valuable information on the condition of the structure. The conventional technique for measuring applied stress is with a strain gage. However, strain gages can be time consuming to install because first the surface must usually be prepared. On a bridge, paint removal will most likely be necessary as part of this surface preparation. When dealing with lead-based paints, which are considered hazardous waste, many time consuming removal procedures are required. Because of these factors, a device that measures applied stress without requiring paint removal could be useful. While a "clamp-on" strain gage can also be used to measure applied stress without requiring paint removal, this type of strain gage can not be used on some bridge details, such as webs of I-beams and tops of box girders. An ultrasonic technique using non-contact electromagnetic transducers provides a possible method for applied stress measurement which is not limited by the same factors as those with conventional strain gages. The transducers operate through nonconductive and conductive (lead-based) paint and work on rusted, pitied surfaces. Our previous research developed a technique for measuring applied stresses on bridges with EMATs and included many laboratory tests. This paper describes field applications of the technique on actual bridge structures, as well as additional system testing and instrument calibration in the laboratory. C1 Fed Highway Adm, Turner Fairbank Highway Res Ctr, Mclean, VA 22101 USA. Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. Virginia Transportat Res Council, Charlottesville, VA 22903 USA. W Virginia Univ, Constructed Facil Ctr, Morgantown, WV 26506 USA. RP Fuchs, PA (reprint author), Fed Highway Adm, Turner Fairbank Highway Res Ctr, Mclean, VA 22101 USA. RI 苏, 日亮/D-4386-2009 NR 13 TC 3 Z9 3 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD SEP PY 1998 VL 17 IS 3 BP 141 EP 152 DI 10.1007/BF02446117 PG 12 WC Materials Science, Characterization & Testing SC Materials Science GA 152YB UT WOS:000077804500004 ER PT J AU Christophorou, LG Olthoff, JK AF Christophorou, LG Olthoff, JK TI Electron interactions with C(3)F(8) SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE C(3)F(8); cross sections; electron attachment; electron collisions; electron transport; perfluoropropane; scattering ID DIFFUSE-DISCHARGE SWITCHES; NEGATIVE-ION DENSITIES; CROSS-SECTION; GAS-MIXTURES; IMPACT IONIZATION; SWARM DATA; ATTACHMENT; CF4; ENERGY; PERFLUOROALKANES AB To aid the many and diverse applications for which perfluoropropane (C(3)F(8)) is suited, we critically evaluate and synthesize existing knowledge on electron scattering and electron energy-loss processes for the C(3)F(8) molecule, and provide recommendations for the most reliable data. We also draw attention to electron-interaction data that are not presently available, but are needed for modeling the behavior of C(3)F(8) in practical uses, especially plasma processing. (C) 1998 American Institute of Physics and American Chemical Society. [S0047-2689(98)00205-0]. C1 NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Christophorou, LG (reprint author), NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. EM loucas.christophorou@nist.gov NR 90 TC 46 Z9 47 U1 0 U2 4 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 SEP-OCT PY 1998 VL 27 IS 5 BP 889 EP 913 PG 25 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 125TG UT WOS:000076252700002 ER PT J AU Archer, DG AF Archer, DG TI Thermodynamic properties of import to environmental processes and remediation. I. Previous thermodynamic property values for cadmium and some of its compounds SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE aqueous solutions; thermodynamic properties ID SOLUBILITY-PRODUCT; ACTIVITY-COEFFICIENTS; SYNTHETIC OTAVITE; 25-DEGREES-C; CONSTANTS; CHLORIDE; SYSTEM; ENTHALPIES; CD(II); WATER AB The sources of previous thermodynamic property values are detailed for cadmium and some compounds of cadmium that might be expected as derivative from anthropogenic introduction of cadmium into the environment or are required for calculation of thermodynamic properties of cadmium-containing systems. Included are descriptions of the sources of information and methodology used to obtain the values for these compounds reported in the NBS series of publications loosely and collectively referred to as the NBS Thermodynamics Tables. (C) 1998 American Institute of Physics and American Chemical Society. [S0047-2689(98)00105-6]. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Archer, DG (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. EM donald.archer@nist.gov NR 125 TC 6 Z9 6 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 1998 VL 27 IS 5 BP 915 EP 946 PG 32 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 125TG UT WOS:000076252700003 ER PT J AU Vogel, E Kuchenmeister, C Bich, E Laesecke, A AF Vogel, E Kuchenmeister, C Bich, E Laesecke, A TI Reference correlation of the viscosity of propane SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE critical data assessment; free-volume model; liquid viscosity; propane; vapor viscosity; viscosity correlation ID INITIAL DENSITY-DEPENDENCE; TRANSPORT-PROPERTIES; THERMAL-CONDUCTIVITY; NOBLE-GASES; CRITICAL REGION; DIFFUSION-COEFFICIENTS; CORRESPONDING STATES; LIQUID PROPANE; ZERO DENSITY; MIXTURES AB A new representation of the viscosity of propane includes a zero-density correlation and an initial-density dependence correlation based on the kinetic theory of dilute gases and on the Rainwater-Friend theory. The higher density contributions of the residual viscosity in the representation are formed by a combination of double polynomials in density and reciprocal temperature, and a free-volume term with a temperature-dependent close-packed density. The full surface correlation is based on a set of primary experimental data selected as a result of a critical assessment of the available information from 37 original viscosity studies. The review refers to 96 citations altogether. The validity of the representation extends from the triple point to 600 K and 100 MPa in accordance with the modified Benedict-Webb-Rubin equation of state. The uncertainty of the representation varies from +/-0.4% for the viscosity of the dilute gas phase between room temperature and 600 K, to about +/-2.5% for the range 100-475 K up to about 30 MPa, and to about +/-4% for points outside this range. Tables of the viscosity according to the representative equations at selected temperatures and pressures and along the saturation line provide easy reference as well as the validation of computer codes. (C) 1998 American Institute of Physics and American Chemical Society. [S0047-2689(98)00405-X]. C1 Univ Rostock, Fachbereich Chem, D-18051 Rostock, Germany. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Vogel, E (reprint author), Univ Rostock, Fachbereich Chem, D-18051 Rostock, Germany. NR 93 TC 117 Z9 117 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 1998 VL 27 IS 5 BP 947 EP 970 PG 24 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 125TG UT WOS:000076252700004 ER PT J AU Toggweiler, JR Samuels, B AF Toggweiler, JR Samuels, B TI On the ocean's large-scale circulation near the limit of no vertical mixing SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; MIXED BOUNDARY-CONDITIONS; WORLD OCEAN; THERMOHALINE CIRCULATION; REALISTIC MODELS; ABYSSAL OCEAN; ENERGY; SENSITIVITY; INSTABILITY; RESPECT AB By convention, the ocean's large-scale circulation is assumed to be a thermohaline overturning driven by the addition and extraction of buoyancy at the surface and vertical mixing in the interior. Previous work suggests that the overturning should die out as vertical mixing rates are reduced to zero. In this paper, a formal energy analysis is applied to a series of ocean general circulation models to evaluate changes in the large-scale circulation over a range of vertical mixing rates: Two different model configurations are used. One has an open zonal channel and an Antarctic Circumpolar Current (ACC). The other configuration does not. The authors find that a vigorous large-scale circulation persists gt the limit of no mixing in the model with a wind-driven ACC. A wind-powered overturning circulation linked to the ACC can exist without vertical mixing and without much energy input from surface buoyancy forces. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Toggweiler, JR (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 32 TC 188 Z9 189 U1 1 U2 17 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1998 VL 28 IS 9 BP 1832 EP 1852 DI 10.1175/1520-0485(1998)028<1832:OTOSLS>2.0.CO;2 PG 21 WC Oceanography SC Oceanography GA 115ZQ UT WOS:000075696800009 ER PT J AU Early, E Thompson, A Johnson, C DeLuisi, J Disterhoft, P Wardle, D Wu, E Mou, WF Ehramjian, J Tusson, J Mestechkina, T Beaubian, M Gibson, J Hayes, D AF Early, E Thompson, A Johnson, C DeLuisi, J Disterhoft, P Wardle, D Wu, E Mou, WF Ehramjian, J Tusson, J Mestechkina, T Beaubian, M Gibson, J Hayes, D TI The 1996 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE environmental monitoring; intercomparison; solar ultraviolet; spectroradiometers ID MERCURY PENCIL LAMPS; STANDARD LAMPS; SPECTRAL-LINES AB Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the third North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers was held June 17-25, 1996 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency; the National Science Foundation; the Smithsonian Environmental Research Center; the Department of Agriculture; and the Atmospheric Environment Service, Canada. The spectral irradiances of participants' calibrated standard lamps were measured at NIST prior to the Intercomparison. The spectral irradiance scales used by the participants agreed with the NIST scale within the combined uncertainties, and for all lamps the spectral irradiance in the horizontal position was lower than that in the vertical position. Instruments were characterized for wavelength uncertainty, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with NIST standard lamps operating in specially designed field calibration units. The spectral irradiance responsivity demonstrated instabilities for some instruments. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamps, the measured solar irradiances had some unexplained systematic differences between instruments. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NOAA, R E ARX1, Boulder, CO 80303 USA. Environm Canada, Atomospher Environm Serv, Toronto, ON M3H 5T4, Canada. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Biospher Inc, San Diego, CA 92110 USA. Yankee Environm Syst Inc, Turners Falls, MA 01376 USA. Colorado State Univ, USDA, UV B Radiat Monitoring Program, Nat Resource Ecol Lab, Ft Collins, CO USA. Smithsonian Inst, Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Early, E (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 9 TC 8 Z9 8 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 SEP-OCT PY 1998 VL 103 IS 5 BP 449 EP 482 DI 10.6028/jres.103.028 PG 34 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 143JZ UT WOS:000077253200001 PM 28009358 ER PT J AU Das, NC Madden, RP Seyoum, HM AF Das, NC Madden, RP Seyoum, HM TI Image evaluation of the high resolution VUV spectrometer at SURF II by ray tracing SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE high resolution; off-plane Eagle; ray tracing; spectrometer; SURF II ID SYNCHROTRON AB A high resolution VUV spectroscopic facility has been in use for several years at SURF II, the Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology in Gaithersburg, Maryland. At this facility, a combination of three cylindrical mirrors is utilized to focus the light originating in the storage ring onto the horizontal entrance slit of the spectrometer. The spectrometer uses a 6.65 m concave grating having a groove density of 4800 lines/mm in the off-plane Eagle mounting. In preparation for the installation of an array detector in the exit image plane, a ray tracing program has been formulated and spot diagrams have been constructed by plotting the coordinates of the points of intersection of the diffracted rays with the image plane, which is tangent to the Rowland circle. In creating the spot diagrams, we have considered both parallel and tilted configurations of the entrance slit with respect to the grating grooves. It is shown that the line widths of the spectral images can be reduced when the entrance slit is properly tilted. Finally, we have estimated the spectral widths of the images when they are recorded on an array detector placed tangent to the Rowland circle. We conclude that an image spectral width of 0.41 pm to 0.88 pm in first order can be achieved over the wavelength region of 40 nm to 120 nm. C1 Bhabha Atom Res Ctr, Div Spect, Bombay 400085, Maharashtra, India. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Dist Columbia, Dept Phys, Washington, DC 20008 USA. RP Das, NC (reprint author), Bhabha Atom Res Ctr, Div Spect, Bombay 400085, Maharashtra, India. NR 9 TC 2 Z9 2 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1998 VL 103 IS 5 BP 483 EP 495 DI 10.6028/jres.103.029 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 143JZ UT WOS:000077253200002 PM 28009381 ER PT J AU Mielenz, KD AF Mielenz, KD TI Algorithms for Fresnel diffraction at rectangular and circular apertures SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE algorithms; circular apertures; diffraction; Fresnel approximation; personal computers; radiometry; rectangular apertures; slits AB This paper summarizes the theory of Fresnel diffraction by plane rectangular and circular apertures with a view; toward numerical computations. Approximations found in the earlier literature, ind,now obsolete, have been eliminated and replaced by algorithms suitable for use on a personal computer. C1 NIST, Radiometr Phys Div, Gaithersburg, MD 20899 USA. NR 16 TC 40 Z9 40 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 SEP-OCT PY 1998 VL 103 IS 5 BP 497 EP 509 DI 10.6028/jres.103.030 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 143JZ UT WOS:000077253200003 PM 28009380 ER PT J AU Eichmiller, FC Hoffman, KM Guiseppetti, AA Wray, MM Avers, RJ AF Eichmiller, FC Hoffman, KM Guiseppetti, AA Wray, MM Avers, RJ TI Acid-assisted consolidation of silver alloys for direct fillings SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE acid-assisted consolidation; cold-welding; consolidated silver ID MERCURY AB Silver-rich metal powders cold-welded by consolidation have been investigated as possible direct dental filling material. The surface of the silver powder must undergo an acid treatment to remove existing contaminants and prevent formation of new surface contaminants during consolidation. This study was designed to investigate the effect of the acid treatment on the strength of the consolidated alloy, its reactivity with the surrounding tooth structure, and its reactions with certain cavity liners. This study investigated the effects of pH and concentration of fluoboric acid on the flexural strength of silver powder consolidated into rectangular beams in a partial 4 x 4 design. The study also assessed, by visible and scanning electron microscopy, what effect the acid-treated powders had on dentin that had been pre-coated with different cavity liners. Mean flexural strengths for beams consolidated using dental hand instruments were in the range (77.0 +/- 9.28) MPa to (166.1 +/- 17.6) MPa, where the quoted uncertainties are standard uncertainties (i.e., one standard deviation estimates). ANOVA indicated that fluoboric acid pH was highly significant (p <0.0001) with lower pH values resulting in higher flexural strength. Concentration alone was not a significant factor for flexural strengths, but there was a significant interaction between concentration and pH (p < 0.0001). Microscopy revealed that the acid-treated silver powder demineralized approximately 2 mu m of dentin when used with no liner. The use of copal or polyamide varnishes eliminated most of this demineralization, but the use of a dentin adhesive liner resulted in some dislodgment and breakdown of the adhesive film by the acid. The results of this study indicate that this silver powder when treated with dilute fluoboric acid at a pH of approximately 1.0 can result in a filling material with strength equivalent to currently used conventional amalgam. The demineralization of tooth structure appears to be minimal and can be eliminated with the use of cavity liners. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. USN, Sch Dent, Gaithersburg, MD 20899 USA. RP Eichmiller, FC (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 13 TC 1 Z9 1 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 SEP-OCT PY 1998 VL 103 IS 5 BP 511 EP 516 DI 10.6028/jres.103.031 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 143JZ UT WOS:000077253200004 PM 28009374 ER PT J AU Burke, JS Ueno, M Tanaka, Y Walsh, H Maeda, T Kinoshita, I Seikai, T Hoss, DE Tanaka, M AF Burke, JS Ueno, M Tanaka, Y Walsh, H Maeda, T Kinoshita, I Seikai, T Hoss, DE Tanaka, M TI The influence of environmental factors on early life history patterns of flounders SO JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Symposium on Flatfish Ecology CY NOV 02-08, 1996 CL NETHERLANDS INST SEA RES, TEXEL, NETHERLANDS SP European Commiss, Programme FAIR, Netherlands Inst Sea Res, Netherlands Inst Fisheries Res, N Carolina State Univ, Royal Netherlands Acad Art & Sci HO NETHERLANDS INST SEA RES DE flounder; tidal migration; settlement distribution; rhythmic behaviour; Japan Sea; Northwest Atlantic ID PARALICHTHYS-OLIVACEUS; JAPANESE FLOUNDER; PLEURONECTES-PLATESSA; NORTH-CAROLINA; SHIJIKI BAY; WADDEN SEA; SETTLEMENT; LARVAL; RECRUITMENT; IMMIGRATION AB The near-shore migration and settlement phases of Japanese and American flounders of the genus Paralichthys are compared and discussed relative to differences in coastal environments. Field sampling was conducted in Wakasa Bay, Kyoto Prefecture, Japan, where the shelf is narrow, estuarine habitat limited and tidal range slight, and in Onslow Bay, North Carolina, USA, where the shelf is broad, estuarine habitat extensive and tide relatively strong. Distribution of larvae and juveniles suggests Japanese flounder spawn in close proximity to nursery grounds relative to flounder in Onslow Bay. Sampling of planktonic and benthic flounder just seaward of nursery grounds resulted in capture of a wide range of developmental stages in Wakasa Bay (early planktonic to juvenile), but was limited to metamorphosing larvae in Onslow Bay. Vertical distribution of larvae during the night also differed between the Bays. At night most larvae in Wakasa Bay remained near the bottom regardless of tidal stage. In contrast, larvae in Onslow Bay exhibited selective tidal stream transport. Laboratory experiments conducted to examine the behaviour of recently captured wild and laboratory-reared larvae indicated that wild flounder from Onslow Bay had an endogenous rhythm of activity that corresponded to the tide at the time of capture. In contrast, wild flounder from Wakasa Bay and laboratory-reared larvae showed no distinct activity pattern. These results suggest that physical characteristics of the environment influence the early life history patterns of flounders by modifying behaviour of migrating larvae. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. Kyoto Univ, Fisheries Res Stn, Maizuru, Kyoto 625, Japan. Kyoto Univ, Div Appl Biosci, Kyoto 611, Japan. RP Burke, JS (reprint author), Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. EM jburke@hatteras.bea.nmfs.gov NR 36 TC 37 Z9 37 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1385-1101 J9 J SEA RES JI J. Sea Res. PD SEP PY 1998 VL 40 IS 1-2 BP 19 EP 32 DI 10.1016/S1385-1101(98)00014-8 PG 14 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 126TA UT WOS:000076308700002 ER PT J AU Lee, CH Hawley, N AF Lee, CH Hawley, N TI The response of suspended particulate material to upwelling and downwelling events in southern Lake Michigan SO JOURNAL OF SEDIMENTARY RESEARCH LA English DT Article ID BENTHIC NEPHELOID LAYER; SEDIMENT TRANSPORT; GREAT-LAKES; RESUSPENSION; ONTARIO; THRESHOLD; CURRENTS; MOVEMENT; STRESS; SHELF AB Time series measurements of water temperature, beam attenuation, and current velocity were made at three stations located in 28, 58, and 100 m of water off the east coast of Lake Michigan from late August until mid-October 1995. When combined with water intake records and wave measurements our observations show that local resuspension is not responsible for maintaining the benthic nepheloid layer (BNL) during the stratified period. Resuspension of bottom material by surface wind waves occurs in shallow water (13 m), but this material is not transported offshore into the BNL during downwelling events. During up upwellings material mag be transported onshore from the BNL into shallow water, but additional material is required to produce the concentrations observed at the inner stations. Resuspension by internal waves mag be the source of this additional material. Changes in the vertical structure of the benthic nepheloid layer appear to account for most of the changes in suspended particulate material at the two offshore stations. These changes are probably due to a combination of internal wave action and regional changes in current pattern. C1 Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. RP Lee, CH (reprint author), Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 34 TC 16 Z9 16 U1 2 U2 5 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 6128 EAST 38TH ST, STE 308, TULSA, OK 74135-5814 USA SN 1527-1404 J9 J SEDIMENT RES JI J. Sediment. Res. PD SEP PY 1998 VL 68 IS 5 BP 819 EP 831 PN A PG 13 WC Geology SC Geology GA 125JC UT WOS:000076233600012 ER PT J AU Rugolo, LJ Knotts, KS Lange, AM AF Rugolo, LJ Knotts, KS Lange, AM TI Historical profile of the Chesapeake Bay blue crab (Callinectes sapidus Rathbun) fishery SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Blue Crab Fisheries of North America at the 88th Annual National-Shellfisheries-Association Meeting CY APR, 1996 CL BALTIMORE, MARYLAND SP Natl Shellfisheries Assoc DE blue crab; Callinectes sapidus; Chesapeake Bay; harvest; population; fishery; sustainable yield AB Blue crabs support the most important commercial and recreational fisheries in the Chesapeake Bay. They have been harvested and cultured for local consumption since colonial times; the directed commercial fishery began in 1880. Maryland and Virginia historically harvested and marketed more blue crabs than any other North American region. Baywide landings in 1995 totaled 33.5 x 10(6) kg; value averaged $53.1 million between 1990 and 1994. With recent declines in other bay fisheries, more recreational and commercial emphasis has been placed on Chesapeake blue crabs. Historical (1945-1995) harvest and effort data for pots, trotlines, dredges, scrapes, and pound nets were examined. Data for the commercial hard crab fishery were more complete and consistent; peeler/soft crab landings and effort data were severely underestimated. Survey estimates of the Maryland recreational harvest in 1983, 1988, and 1990 were 78.6, 49.5, and 25.9% respectively, of the reported commercial harvest; no other recreational landings data were available. Blue crab landings were inherently variable among years. Three periods of low apparent stock abundance since 1929 were indicated: 1930 to 1945, 1951 to 1960, and 1968 to 1980. High commercial harvests occurred in 1981 and 1983 (similar to 47 x 10(6) kg). The crab pot has been the dominant gear, accounting for 40 to 80% of the landings from 1945 to 1995, and 70% since 1981. Trotline landings were 6 to 38% of the total since 1945, averaging 21% since 1981, as compared to 5 to 25% and 9%, respectively, for the dredge fishery. Scrapes and pound nets contributed <1% of the total. Hard crabs historically were >90% of blue crab landings by weight. Soft crabs were more valuable, averaging $1.25/kg versus $0.29/kg for hard crabs. Harvest and effort data for 1982 to 1995 revealed no evidence of a decline in Maryland pot and trotline fisheries. Mean kg/pot/month for the pot fishery increased from 10 to 19 from 1982 to 1984 and declined to 10 in 1994. Trotline mean kg/trotline-h/mo increased between 1982 and 1985 from 21 to 35 and remained fairly constant thereafter. Maryland and baywide total yield has varied without trend since 1982 and 1945, respectively. Baywide nominal directed effort displayed a near fivefold increase in 1945, resulting in sharply declining catch per unit effort (CPUE) in the commercial fisheries. The majority of this decline occurred by the late 1960s. Baywide CPUE has been noisy but without trend since 1970. The exponential decline in CPUE reflected a decline in the catchability of the gear (gear saturation) rather than a decline in the stock The Chesapeake Bay blue crab fishery is overcapitalized, with relatively constant harvest divided among increasing gear units and number of participants. Market category data revealed that Maryland female harvest is 8% above the 1982 to 1995 average; Virginia winter dredge female landings in 1993 to 1994 were 29% below the 1982 to 1992 average. Baywide female blue crab harvest was slightly below the long-term average from 1982 to 1995. The Baywide commercial fisheries have realized yield at approximately the value of maximum sustainable yield (MSY; 37-39 x 10(6) kg) during the last 15 years. Total yield approximated or exceeded MSY in the mid-1960s and after 1980. Current yield was slightly below MSY. The Chesapeake Bay blue crab population is maintaining recruitment to the stock, and levels of exploitable and spawning stock biomass at near long-term average levels of abundance. C1 Maryland Dept Nat Resources, Fisheries Serv, Annapolis, MD 21401 USA. NOAA, Natl Marine Fisheries Serv, Off Intergovt & Recreat Fisheries, Silver Spring, MD USA. RP Rugolo, LJ (reprint author), Maryland Dept Nat Resources, Fisheries Serv, Annapolis, MD 21401 USA. NR 19 TC 15 Z9 15 U1 1 U2 10 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD SEP PY 1998 VL 17 IS 2 BP 383 EP 394 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 128WF UT WOS:000076430800006 ER PT J AU Stehlik, LL Scarlett, PG Dobarro, J AF Stehlik, LL Scarlett, PG Dobarro, J TI Status of the blue crab fisheries of New Jersey SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Blue Crab Fisheries of North America at the 88th Annual National-Shellfisheries-Association Meeting CY APR, 1996 CL BALTIMORE, MARYLAND SP Natl Shellfisheries Assoc DE blue crab; Callinectes sapidus; fisheries ID SOUTHERN NEW-JERSEY; DELAWARE BAY; BRACHYURAN MEGALOPAE; CALLINECTES-SAPIDUS; HABITATS; PREDATION; ABUNDANCE; MARSH AB New Jersey is near the northern extreme of the range of the blue crab, Callinectes sapidus. Blue crabs occur in Raritan Bay, Atlantic coastal estuaries and sounds, and in Delaware Bay. Spawning proceeds during the summer, peaking in July and August. Based on monthly trawl surveys in the Delaware Bay, the period of greatest occurrence of newly settled juveniles seems to be August through October. Wire mesh pots and dredges are the principal commercial fishing gear. Minimum size for the commercial harvest of hard crabs is 4 3/4 in, and egg-bearing females cannot be possessed. Many crabbers bait pots with males to catch shedder crabs in late spring and summer months. These crabs are held in floats or flow-through tanks to shed and then sold to wholesalers or retailers. From December 1 to March 31, crab dredging is permitted in most estuaries. Commercial licenses are needed for crab potting and dredging. Current regulations are intended to reduce the number of pot and dredge licenses by limited entry and attrition. Statewide commercial landings have increased from low levels in the early 1980s and have remained high. In 1994, the catch was 5.6 x 10(6) pounds, at an ex-vessel value of $4.1 million. The shedder harvest reached an all-time high of 3.5 x 10(6) pounds in 1995. The recreational catch of blue crabs is substantial and may equal or exceed the commercial catch. A recreational license is needed to set a maximum of two commercial-style pots. The minimum size for the recreational catch of hard crabs is 4 1/2 in., with a maximum per person harvest of one bushel per day. Hand lines, collapsible traps, and dip nets may be used without a license. C1 NOAA, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. NJ Div Fish Game & Wildlife, Nacote Creek Res Stn, Port Republic, NJ 08241 USA. Rutgers State Univ, Inst Marine & Coastal Sci, Tuckerton, NJ 08087 USA. RP Stehlik, LL (reprint author), NOAA, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. NR 22 TC 7 Z9 7 U1 0 U2 4 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD SEP PY 1998 VL 17 IS 2 BP 475 EP 485 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 128WF UT WOS:000076430800017 ER PT J AU Rugolo, LJ Knotts, KS Lange, AM Crecco, VA AF Rugolo, LJ Knotts, KS Lange, AM Crecco, VA TI Stock assessment of Chesapeake Bay blue crab (Callinectes sapidus Rathbun) SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Blue Crab Fisheries of North America at the 88th Annual National-Shellfisheries-Association Meeting CY APR, 1996 CL BALTIMORE, MARYLAND SP Natl Shellfisheries Assoc DE blue crab; Callinectes sapidus; Chesapeake Bay; harvest; population; fishery; exploitation; stock assessment; status; gear saturation ID MODEL AB This stock assessment stemmed from concerns about declines in Chesapeake Bay blue crab commercial yield, survey abundance indices, and economic performance in the 1990s. Blue crab vital rates and life-history characteristics were described. A risk-averse approach was adopted for parameter estimation. Extant (50 y) fisheries-independent and dependent data were compiled. Current spawning stock biomass was at moderate levels, as compared to historical maxima; total stock biomass was at long-term average levels since 1956. Juvenile recruitment has been variable since the 1950s. The stock is in long-term dynamic equilibrium, demonstrating variable abundance as expected in a strongly r-selected species. No evidence of a persistent stock decline was found. The decade of the 1980s was a period of above average abundance; the population modulated to average levels thereafter. Maryland commercial catch per unit effort (CPUE) has remained fairly stable from 1982 to 1995. Baywide yield varied without trend since 1945, cycling around the long-term mean with peaks in 1950, 1966, 1981, and 1993 and troughs in the mid-1950s and late 1970s to early 1980s. Baywide data since 19-15 demonstrated a fivefold increase in directed effort (f) and an exponential decline in CPUE: rapidly from 1947 to 1967, and without trend since 1970. The stock has supported maximum sustainable yield (MSY) = 37-38.5 x 10(6) kg since 1935 with no observed change in the ability of the stock to replace itself or to provide historical average yield. We judged the stock to be moderately to fully exploited at average levels of abundance. Stock-recruitment (S-R) analysis revealed weak relationships. Density-independent effects accounted for little of the variability in the S-R model. Exploitation rates for 1956 to 1996 ranged from 30-40% for peeler/soft crabs and 40-55% for hard crabs. Fishing mortality (F) ranged largely between 0.8-1.0 (F < 1.20) since 1956 within +/- 20% of the long-term mean; fully recruited F in 1996 was 0.87. Current F was below the threshold reference level of F-10% = 1.21, where F-REP = 1.17. Yield per recruit (YPR) modeling estimated F-0.1 = 0.36 and F-MAX = 0.64. The stock is strictly growth overfished with a 26% reduction in F-10% required to maximize (+2% gain) YPR. Longevity was established at 8 y. Tagging studies showed that blue crabs live considerably longer than curren convention (3 y). A life-table model reconciled the apparent disparity between this convention and the life-history parameters used in the assessment. At current total mortality (Z)approximate to 1.3, the mean age of the observed stock would be 1.5 y (153 mm CW [carapace width]; 97.3% of all individuals would be greater than or equal to 3 y of age. The dramatic rise in f since 1945 with the accompanying decline in CPUE was not associated with an increase in F. Catachability (q) has varied with f from 1956 to 1995 as a result of gear saturation. Moderate reductions in f would not result in a proportional reduction in F because of nonconstant q. The blue crab fishery is severely overcapitalized in terms of total effort. As a result of gear saturation, marginal decreases in fishing effort would not realize proportional gains in CPUE, %MSP, or YPR. Substantial economic displacement would be required to maximize YPR. Increases in %MSP and YPR could be realized through increased size limits and regulating the taking of mature female crabs, without the displacement costs associated with effort reductions alone. We recommend a risk-averse management strategy: maintain current F below F-10%. Management should be particularly averse to increases in effort that would exacerbate current economic inefficiencies, or to increases ih gear efficiency. The latter concern acknowledges the delicate interplay between F and f in the fishery. Management should be proactive: stabilize and enhance the economic viability of the fishery and provide protection for the stock through maintenance of greater than or equal to 10% maximum spawning potential (MSP). It should consider adopting strategies which increase YPR (e.g., size limit measures on both sexes) and spawning potential (e.g., limit directed fisheries on mature female crabs). C1 Maryland Dept Nat Resources, Fisheries Serv, Annapolis, MD 21401 USA. NOAA, Natl Marine Fisheries Serv, Off Intergovt & Recreat Fisheries, Silver Spring, MD 20912 USA. Connecticut Dept Environm Protect, Div Fisheries, Old Lyme, CT 06371 USA. RP Rugolo, LJ (reprint author), Maryland Dept Nat Resources, Fisheries Serv, Annapolis, MD 21401 USA. NR 29 TC 32 Z9 32 U1 0 U2 10 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD SEP PY 1998 VL 17 IS 2 BP 493 EP 517 PG 25 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 128WF UT WOS:000076430800019 ER PT J AU Engel, DW Thayer, GW AF Engel, DW Thayer, GW TI Effects of habitat alteration on blue crabs SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Blue Crab Fisheries of North America at the 88th Annual National-Shellfisheries-Association Meeting CY APR, 1996 CL BALTIMORE, MARYLAND SP Natl Shellfisheries Assoc DE habitat; blue crab; Callinectes sapidus; development; degradation; contaminants; organics; pesticides; physical destruction ID TIDAL MARSH CREEK; CALLINECTES-SAPIDUS; SEAGRASS MEADOW; ABUNDANCE; PATTERNS; WATER; CUES; BAY AB Blue crabs, Callinectes sapidus, are an estuarine and coastal species subject to a wide range of environmental conditions. Their survival, growth, reproduction, and abundance are influenced by both natural processes and events and by human activities. How such activities might affect the survival and abundance of blue crabs is the focus of this discussion. Because the life cycles and growth of blue crabs and other crustaceans are relatively complex, they are vulnerable to chemical and physical alterations to their habitat in different ways during their life. Not only are insults to the different life stages important, but negative impacts to the food webs that support them may also be damaging. When dealing with human-induced alterations to the environment, we often become preoccupied with the introduction of toxic chemicals and pesticides and their effects on individual organisms, and overlook less emotionally charged but more widespread threats, such as nutrient loading, alterations of freshwater inflow, and physical destruction of estuarine and coastal habitat. Increasing human population densities and development near the Atlantic and Gulf of Mexico coasts may pose the greatest threat to blue crab populations through alterations of upland watersheds with increased runoff, erosion, and turbidity, and increased nonpoint-source runoff of chemicals and nutrients. Unless these activities are adequately controlled, the degradation of coastal habitat necessary for the survival and growth of blue crab populations will grow. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort Lab, Beaufort, NC 28516 USA. RP Engel, DW (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort Lab, Beaufort, NC 28516 USA. NR 40 TC 5 Z9 6 U1 3 U2 11 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD SEP PY 1998 VL 17 IS 2 BP 579 EP 585 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 128WF UT WOS:000076430800027 ER PT J AU Lerch, TP Schmerr, LW Sedov, A AF Lerch, TP Schmerr, LW Sedov, A TI Ultrasonic beam models: An edge element approach SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID TRANSIENT; TRANSDUCER; PRESSURE AB A new method, the edge element method, has been developed to numerically evaluate a variety of ultrasonic transducer beam models. The edge element technique divides the transducer surface into a web of sources consisting of radiating straight line elements whose individual contributions can be evaluated analytically. When all of these edge elements are summed, the wave field of the transducer can be obtained at any field point in the surrounding medium for a given ultrasonic frequency. To demonstrate the versatility of this approach, it is shown that edge elements can accurately model the wave fields radiated into a fluid by focused and unfocused transducers of circular and noncircular apertures. (C) 1998 Acoustical Society of America. [S0001-4966(98)02209-7]. C1 Iowa State Univ, Ctr NDE, Ames, IA 50011 USA. Iowa State Univ, Dept Aerosp Engn & Engn Mech, Ames, IA 50011 USA. Lakehead Univ, Dept Mech Engn, Thunder Bay, ON P7B 5E1, Canada. RP Lerch, TP (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 22 TC 20 Z9 20 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 1998 VL 104 IS 3 BP 1256 EP 1265 DI 10.1121/1.424334 PN 1 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 118WW UT WOS:000075864800013 ER PT J AU Tewary, VK AF Tewary, VK TI Inversion of elastic waveform data in anisotropic solids using the delta-function representation of the Green's function SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Letter AB A method for inversion of measured data on elastic waveforms in anisotropic solids is proposed, using the delta-function representation of the Green's function. The method requires integration over a closed 2-D (two-dimensional) space. In contrast, inversion using the traditional Fourier representation requires integration over an infinite 4-D space. The method can be used to determine the Green's function for imaging applications and elastic constants for materials characterization. The method is illustrated by applying it to determine all six elastic constants of a model graphite fiber composite assuming a tetragonal structure and using simulated data. (C) 1998 Acoustical Society of America. [S0001-4966(98)04509-3] C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Tewary, VK (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 8 TC 4 Z9 4 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 1998 VL 104 IS 3 BP 1716 EP 1719 DI 10.1121/1.424384 PN 1 PG 4 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 118WW UT WOS:000075864800063 ER PT J AU Swab, JJ Quinn, GD AF Swab, JJ Quinn, GD TI Effect of precrack "halos" on fracture toughness determined by the surface crack in flexure method SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN, 1997 CL COCOA BEACH, FLORIDA ID HOT-PRESSED SI3N4; ADVANCED STRUCTURAL CERAMICS; SILICON-NITRIDE; FLAWS; INDENTATION; GROWTH; STRENGTH; ALUMINA; RESISTANCE; PARAMETERS AB The surface crack in flexure method, which is used to determine the fracture toughness of dense ceramics, necessitates the measurement of precrack sizes by fractographic examination. Stable crack extension may occur from flaws under ambient, room-temperature conditions, even in the relatively short time under load during fast fracture strength or fracture toughness testing. In this article, fractographic techniques are used to characterize evidence of stable crack extension, a "halo," around Knoop indentation surface cracks. Optical examination of the fracture surfaces of a high-purity Al2O3, an AlN, a glass-ceramic, and a MgF2 reveal the presence of a halo around the periphery of each precrack, The halo in the AlN is merely an optical effect due to crack reorientation, whereas the halo in the MgF2 is due to indentation-induced residual stresses initiating crack growth. However, for the Al2O3 and the glass-ceramic, environmentally assisted slow crack growth is the cause of the halo. In the latter two materials, this stable crack extension must be included as part of the critical crack size to determine the appropriate fracture toughness. C1 USA, Res Lab, Weap & Mat Res Directorate, Met & Ceram Res Branch, Aberdeen Proving Ground, MD 21005 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Swab, JJ (reprint author), USA, Res Lab, Weap & Mat Res Directorate, Met & Ceram Res Branch, Aberdeen Proving Ground, MD 21005 USA. NR 55 TC 23 Z9 23 U1 2 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1998 VL 81 IS 9 BP 2261 EP 2268 PG 8 WC Materials Science, Ceramics SC Materials Science GA 121AB UT WOS:000075989000006 ER PT J AU Lee, KS Lee, SK Lawn, BR Kim, DK AF Lee, KS Lee, SK Lawn, BR Kim, DK TI Contact damage and strength degradation in brittle/quasi-plastic silicon nitride bilayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HETEROGENEOUS GRAIN-STRUCTURE; SHORT-CRACK TOUGHNESS; FRACTURE-TOUGHNESS; MECHANICAL CHARACTERIZATION; HERTZIAN CONTACTS; CERAMICS; MICROSTRUCTURE; CARBIDE; ALUMINA; BEHAVIOR AB A study is made of the damage resistance of silicon nitride bilayers consisting of a hard overlayer (coating) on a soft underlayer (substrate). The tao layers are fabricated with different starting powders, to provide distinctive elongate-grain microstructures, and are cosintered, to provide strong interfacial bonding and thus to minimize subsequent delamination, Contact testing with spherical indenters is used to characterize the damage response. The elastic-plastic mismatch between the layers is sufficiently high as to produce distinctive damage modes in the two layers: predominantly cone cracking in the coating, and quasi-plasticity in the substrate, However, the mismatch is also sufficiently low as to preclude secondary transverse cracks of the kind observed in other bilayer systems to initiate immediately beneath the contact at the coating/substrate interface and propagate upward within the coating. The dominant damage mode shifts from coating fracture to substrate quasi-plasticity with increasing contact load and decreasing coating thickness. Significantly, the presence of the soft underlayer inhibits growth of the coating cone cracks as the latter approach and intersect the interface. The underlayer also substantially diminishes strength losses from the contact-induced damage, especially in bilayers with thinner coatings. The implication is that bilayer structures with thin, hard coatings can preserve benefits from the inherent toughness of soft substrate materials, and at the same time afford surface protection (high wear resistance) to the underlayer. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Korea Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. RP Korea Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. RI Kim, Do Kyung/C-2039-2011 OI Kim, Do Kyung/0000-0001-9092-9427 NR 42 TC 43 Z9 43 U1 0 U2 7 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 SEP PY 1998 VL 81 IS 9 BP 2394 EP 2404 PG 11 WC Materials Science, Ceramics SC Materials Science GA 121AB UT WOS:000075989000021 ER PT J AU Hackley, VA AF Hackley, VA TI Colloidal processing of silicon nitride with poly(acrylic acid): II. Rheological properties SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SUSPENSIONS; ADSORPTION; DISPERSIONS AB Poly(acrylic acid) (PAA) was the focus of an investigation in the role and behavior of polyelectrolyte dispersants in aqueous-based colloidal processing of silicon nitride, The steady-shear flow properties of dense suspensions were examined as a function of pH, particle volume fraction, chain length, and polymer concentration. Suspensions exhibited shear-thinning behavior, which was analyzed using the constitutive Bingham equation for plastic flow. The data showed that polyelectrolyte charge and configuration were important in the observed flow behavior. In acidic media, PAA behaved similar to a neutral polymer in a poor solvent, whereas, in alkaline media, PAA behaved similar to a rigid asymmetric particle. Although electrostatic forces dominated flow properties in alkaline media, where PAA was predominantly in the free-polymer form, at lower pH values, PAA interactions with the particle surface resulted in a complex array of suspension effects, including polymer bridging, electrosteric stabilization, and flocculation. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 16 TC 63 Z9 66 U1 1 U2 10 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 SEP PY 1998 VL 81 IS 9 BP 2421 EP 2428 PG 8 WC Materials Science, Ceramics SC Materials Science GA 121AB UT WOS:000075989000024 ER PT J AU Zimmermann, A Hoffman, M Flinn, BD Bordia, RK Chuang, TJ Fuller, ER Rodel, J AF Zimmermann, A Hoffman, M Flinn, BD Bordia, RK Chuang, TJ Fuller, ER Rodel, J TI Fracture of alumina with controlled pores SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID STRESS INTENSITY FACTORS; GRAIN-SIZE; WEIGHT FUNCTION; CRACK; CERAMICS; STRENGTH; LONG AB Fracture from artificial spherical pores, as well as natural defects, in alumina in a grain-size range of 0.8-9.2 mu m has been studied experimentally and compared with a fracture-mechanics model, Results from fracture-strength measurements have been combined with detailed fractographic analysis to elucidate the ensuing crack instability. Two existing models of possible crack configurations have been extended and contrasted. The semicircular crack as well as the circumferential crack both are described as flaws in the stress-concentrating field of a spherical pore. Surface correction terms afforded by the presence of the pore have been incorporated. A comparative computation shows that fracture occurs more likely from the semicircular crack configuration than the circumferential crack configuration. C1 Tech Univ Darmstadt, Ceram Grp, Dept Mat Sci, D-64287 Darmstadt, Germany. Univ Washington, Seattle, WA 98195 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Zimmermann, A (reprint author), Tech Univ Darmstadt, Ceram Grp, Dept Mat Sci, Petersenstr 30, D-64287 Darmstadt, Germany. RI Flinn, Brian/A-4121-2011; Hoffman, Mark/E-5021-2012 OI Hoffman, Mark/0000-0003-2927-1165 NR 34 TC 37 Z9 38 U1 0 U2 8 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1998 VL 81 IS 9 BP 2449 EP 2457 PG 9 WC Materials Science, Ceramics SC Materials Science GA 121AB UT WOS:000075989000027 ER PT J AU Tierney, BJ Pitner, WR Mitchell, JA Hussey, CL Stafford, GR AF Tierney, BJ Pitner, WR Mitchell, JA Hussey, CL Stafford, GR TI Electrodeposition of copper and copper-aluminum alloys from a room-temperature chloroaluminate molten salt SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTROCHEMISTRY; DEPOSITION; COBALT; MELT AB The electrodeposition of copper and copper-aluminum alloys was investigated in the Lewis acidic aluminum chloricle-1-methyl-3-ethylimidazolium chloride (60.0-40.0 mol %) molten salt containing electrogenerated Cu(I) at 40 +/- 1 degrees C. Sampled current and rotating ring-disk electrode voltammetry experiments indicated that it was possible to produce Cu-Al alloy deposits at potentials positive of that corresponding: to the electrodeposition of bulk aluminum (similar to 0 V). For a 5.0 x 10(-3) mol L-1 solution of Cu(I), the onset of the aluminum codeposition process was found to occur at around 0.30 V vs. the Al(III)/Al couple; however; a limiting current for the reduction of Cu(I) to pure copper metal can be observed in the 0.60-0.30 V potential interval in this solution. The Cu-Al alloy composition was found to be independent of the Cu(I) concentration, reaching a maximum value of 43 percent atomic fraction aluminum at 0 V. The surface morphology of bulk Cu-Al alloy electrodeposits was highly dependent on the aluminum content; pure copper deposits had a dense, nodular appearance, whereas deposits containing appreciable amounts of aluminum consisted of fragile dendrites. X-ray diffraction studies indicated that Cu-Al deposits containing about 7.2 percenter atomic fraction Al retained the face-centered cubic (fcc) copper structure; however; deposits containing 12.8 percent atomic fraction Al were two-phase with the second phase tentatively identified as martensitic beta'-Cu3Al. This phase appears to form before fee copper becomes saturated with aluminum. C1 Univ Mississippi, Dept Chem, University, MS 38677 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Tierney, BJ (reprint author), Univ Mississippi, Dept Chem, University, MS 38677 USA. NR 26 TC 62 Z9 65 U1 2 U2 25 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1998 VL 145 IS 9 BP 3110 EP 3116 DI 10.1149/1.1838772 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 112DR UT WOS:000075479300024 ER PT J AU Wiese, WL AF Wiese, WL TI Atomic oscillator strengths for light elements - Progress and problems SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT 5th Symposium on Laser Spectroscopy CY NOV 07-08, 1998 CL KOREA ATOM ENERGY RES INST, TAEJON, SOUTH KOREA HO KOREA ATOM ENERGY RES INST ID SPECTROSCOPIC COUPLING SCHEME; TRANSITION-PROBABILITIES; ASTROPHYSICAL INTEREST; OPACITY CALCULATIONS; SPECTRAL-LINES; NEUTRAL OXYGEN; II LINES; NITROGEN; CARBON; TESTS AB The status of our knowledge of atomic oscillator strengths for light elements is reviewed. Great progress has been achieved for these atomic data, when sophisticated atomic structure codes developed in the late 1960s and 70s were recently applied to very large numbers of spectral lines. Furthermore, experimental determinations of oscillator strengths have significantly improved in accuracy, but have been limited to relatively few transitions. Therefore, experimental data mainly serve as test cases to evaluate the accuracy of the calculations since these are still not able to provide reliable uncertainty estimates. Oscillator strengths for the hydrogen, helium, lithium and beryllium atoms and their isoelectronic ions have been calculated to a very high degree of accuracy. However, starting with boron, the atomic energy level structure, especially for the neutral atoms, shows increasing complexity, with energy levels of core-excited states sometimes located very close to normal valence states of the same parity and spectroscopic designation. In such cases configuration interaction becomes quite strong, and calculations of great detail are required in order to fully account for these configuration mixing effects. For individual spectral lines, i.e., fine-structure transitions, the additional problem of the spectroscopic coupling arises, and sometimes significant departures from Russell-Saunders or LS-coupling are encountered. Uncertainties in the calculations of individual line strengths are typically +/-10 % for the stronger lines and increase to the 25 - 50 % range for weak lines. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wiese, WL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 30 TC 2 Z9 2 U1 0 U2 0 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD SEP PY 1998 VL 33 IS 3 BP 207 EP 213 PG 7 WC Physics, Multidisciplinary SC Physics GA 120TR UT WOS:000075972900002 ER PT J AU Kim, YK Desclaux, JP Indelicato, P AF Kim, YK Desclaux, JP Indelicato, P TI Calculation of transition probabilities using the multiconfiguration Dirac-Fock method SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT 5th Symposium on Laser Spectroscopy CY NOV 07-08, 1998 CL KOREA ATOM ENERGY RES INST, TAEJON, SOUTH KOREA HO KOREA ATOM ENERGY RES INST AB The performance of the multiconfiguration Dirac-Fock (MCDF) method in calculating transition probabilities of atoms is reviewed. In general, the MCDF wave functions will lead to transition probabilities accurate to similar to 10 % or better for strong, electric-dipole allowed transitions for small atoms. However, it is more difficult to get reliable transition probabilities for weak transitions. Also, some MCDF wave functions for a specific J quantum number may not reduce to the appropriate L and S quantum numbers in the nonrelativistic limit. Transition probabilities calculated from such MCDF wave functions for nonrelativistically forbidden transitions are unreliable. Remedies for such cases are discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. CEA, Direct Sci Mat, F-38054 Grenoble 9, France. Univ Paris 06, F-75252 Paris 5, France. Ecole Normale Super, Lab Kastler Brossel, F-75231 Paris, France. RP Kim, YK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 13 TC 1 Z9 1 U1 0 U2 0 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD SEP PY 1998 VL 33 IS 3 BP 218 EP 222 PG 5 WC Physics, Multidisciplinary SC Physics GA 120TR UT WOS:000075972900004 ER PT J AU Kendrick, C Semancik, S AF Kendrick, C Semancik, S TI Doping effects and reversibility studies on gas-exposed alpha-sexithiophene thin films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID FIELD-EFFECT TRANSISTORS; ELECTRICAL CHARACTERISTICS; THIOPHENE OLIGOMERS; AQUEOUS-SOLUTION; POLYPYRROLE; POLY(3-METHYLTHIOPHENE); SEMICONDUCTOR; POLYMERS; DEVICES; SENSOR AB The electronic effects produced by controlled gas exposures on alpha-sexithiophene thin films have been investigated using x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Incremental exposures of alpha 6T films to NO2, O-2, NH3 in N-2, and water vapor in N-2 were performed in ultrahigh vacuum, while repeated doses of O-2, H-2 in N-2, and methanol vapor in N-2 were performed ex situ at ambient pressure. In both conditions XPS spectra of gas-exposed films showed no evidence of chemical changes. However, the features in both XPS and UPS spectra were observed to shift as a function of gas dosage, with the magnitude dependent on each particular gas. These effects could be reversed by heating the films to temperatures around 100 K. This behavior is interpreted in terms of doping by weakly bonded gas species within the near-surface region of the alpha 6T films. Greater doping effects were observed for films dosed at ambient pressure. We discuss possible gas adsorption models that may explain the differing gas sensitivities and their dependences on pressure, temperature, and exposure lime. Finally, temperature programmed desorption was used to study the reversibility and resistance to reaction of a6T films during this gas adsorption/desorption process. The films were found to be chemically stable to gas exposure and subsequent thermal desorption in the dosage ranges explored. (C) 1998 American vacuum Society. [S0734-2101 (98)00705-2]. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Kendrick, C (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. EM kendrick@nist.gov NR 33 TC 13 Z9 13 U1 2 U2 16 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1998 VL 16 IS 5 BP 3068 EP 3075 DI 10.1116/1.581460 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 121MJ UT WOS:000076017300047 ER PT J AU Powell, MD Houston, SH Amat, LR Morisseau-Leroy, N AF Powell, MD Houston, SH Amat, LR Morisseau-Leroy, N TI The HRD real-time hurricane wind analysis system SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article; Proceedings Paper CT 8th US National Conference on Wind Engineering CY JUN 05-07, 1997 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Amer Assoc Wind Engn, Natl Sci Fdn, Johns Hopkins Univ, Dept Civil Engn HO JOHNS HOPKINS UNIV DE hurricanes; tropical cyclones; emergency management; data assimilation; disaster mitigation ID ANDREW LANDFALL; SOUTH FLORIDA; FIELDS AB The HRD real-time wind analysis system is currently undergoing evaluation in the operational forecasting environment of the National Hurricane Center. The system is an object-oriented, distributed, three-tiered client-server application that assimilates disparate observations and processes the data into a common framework for exposure, height and averaging time. The data are then examined collectively or by type, quality controlled and passed on to a scale-controlled objective analysis algorithm. Several products are derived from the analysis wind field and storm track, yielding effective tools for disaster assessment, emergency management, and recovery. Published by Elsevier Science Ltd. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Powell, MD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Cswy, Miami, FL 33149 USA. RI Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 11 TC 264 Z9 267 U1 5 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AEROD JI J. Wind Eng. Ind. Aerodyn. PD SEP-DEC PY 1998 VL 77-8 BP 53 EP 64 DI 10.1016/S0167-6105(98)00131-7 PG 12 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA 144EP UT WOS:000077301200006 ER PT J AU Whalen, T Simiu, E Harris, G Lin, J Surry, D AF Whalen, T Simiu, E Harris, G Lin, J Surry, D TI The use of aerodynamic databases for the effective estimation of wind effects in main wind-force resisting systems: application to low buildings SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article; Proceedings Paper CT 8th US National Conference on Wind Engineering CY JUN 05-07, 1997 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Amer Assoc Wind Engn, Natl Sci Fdn, Johns Hopkins Univ, Dept Civil Engn HO JOHNS HOPKINS UNIV DE aerodynamics; building technology; standards; structural engineering; wind loads AB As a part of the ongoing National Institute of Standards and Technology research on the development of a new generation of standard provisions for wind loads, we present results of a pilot project on the estimation of wind effects in low-rise building frames. We use records of wind pressure time histories measured at a large number of taps on the building surface in the boundary layer wind tunnel of the University of Western Ontario. Time histories of bending moments in a frame are obtained by adding pressures at all taps tributary to that frame multiplied by the respective tributary areas and influence coefficients. The latter were obtained from the frame designs provided by CECO Building Systems. We compare results obtained by using the pressure time history records with results based on ASCE 7 standard provisions. The comparison suggests that provisions which use aerodynamic databases containing the type of data described in this work can result in designs that are significantly more risk-consistent as well as both safer and more economical than designs based on conventional standard provisions. We outline future research on improved design methodologies made possible by the proposed approach to the estimation of wind effects. We note that the use of the proposed methodologies is fully consistent with the ASCE 7 Standards insofar as these allow the use of wind-tunnel data for estimating wind load effects. Finally, We note that the proposed methodologies may be used for damage assessment for insurance purposes. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. CECO Bldg Syst, Columbus, MS 39703 USA. Univ Western Ontario, Boundary Layer Wind Tunnel Lab, London, ON N6A 5B9, Canada. RP Simiu, E (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 6 TC 33 Z9 33 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AEROD JI J. Wind Eng. Ind. Aerodyn. PD SEP-DEC PY 1998 VL 77-8 BP 685 EP 693 DI 10.1016/S0167-6105(98)00183-4 PG 9 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA 144EP UT WOS:000077301200058 ER PT J AU Hastie, JW Chrisey, DB AF Hastie, JW Chrisey, DB TI Laser deposition holds promise, needs development SO LASER FOCUS WORLD LA English DT News Item C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Res Lab, Plasma Proc Sect, Washington, DC USA. RP Hastie, JW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 USA SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD SEP PY 1998 VL 34 IS 9 BP 18 EP + PG 2 WC Optics SC Optics GA 117NQ UT WOS:000075788700012 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Interactions among Cu2+, Zn2+, and Mn2+ in controlling cellular Mn, Zn, and growth rate in the coastal alga Chlamydomonas SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID DIATOM THALASSIOSIRA-WEISSFLOGII; PHYTOCHELATIN PRODUCTION; MARINE-PHYTOPLANKTON; MANGANESE; ZINC; LIMITATION; CADMIUM; TRANSPORT; COPPER; IRON AB Culture experiments with the green alga Chlamydomonas sp. in metal ion-buffered media revealed antagonistic interactions between toxic metals (Cu and Zn) and nutrient metals (Zn and Mn) in regulating cellular Mn and Zn uptake and specific growth rate. High levels of ionic Cu2+ and Zn2+ inhibited cellular Mn uptake, and high Cu2+ inhibited Zn uptake rates. These effects were associated with growth rate inhibition at combined conditions of high Zn2+ and low Mn2+ and at high Cu2+ and low Zn2+. Zinc inhibited Mn uptake by competitively blocking Mn binding to a high-affinity Mn uptake system which was under negative feedback regulation. Kinetic modeling suggested that Zn was taken up by this system, and as a result, cellular Zn concentrations increased as external Mn2+ was decreased. Zinc uptake behavior was complex, and in addition to the Mn system, uptake appeared to involve a high-affinity Zn system induced at low Zn2+ and a separate constitutive low-affinity system. High Cu2+ levels inhibited zinc uptake by the high-affinity transport system. Such complex competitive interactions among metals provide important controls on cellular metal accumulation, toxicity, and nutrition. C1 NOAA, Beaufort Lab, NMFS, Beaufort, NC 28516 USA. RP Sunda, WG (reprint author), NOAA, Beaufort Lab, NMFS, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 20 TC 64 Z9 69 U1 1 U2 18 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 1998 VL 43 IS 6 BP 1055 EP 1064 PG 10 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 135GC UT WOS:000076791700003 ER PT J AU Cantillo, AY AF Cantillo, AY TI Comparison of results of mussel watch programs of the United States and France with worldwide mussel watch studies SO MARINE POLLUTION BULLETIN LA English DT Article AB As part of the Global (GOOS), the National Oceanic and Atmospheric Administration (NOAA) National Status and Trends (NS&T) Program compiled the World Mussel Watch (WMW) data base with results from the analyses of marine or estuarine mussels or oysters as far back in time as possible. Here we compare WMW data with results from two long-term Mussel Watch Programs, the Reseau National d'Observation de la Qualite du Mulieu Marin (RNO) Mussel Watch in France and NS&T Program in the United States. The medians and 85th percentiles for Cr, Ni, Cu, Zn, As, Se, Ag, Cd, Hg and Pb in mussels and oysters were calculated for the WMW NS&T and RNO Mussel Watch programs. While there was generally good agreement for medians among all three data sets, the upper ends of the WMW concentrations tend to be higher than their NS&T and RNO counterparts. This probably reflects the fact that the latter two programs emphasize collection of mollusks at representative sites rather than within small areas of extreme contamination such as near waste discharges. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NOAA, Natl Ocean Serv, Off Ocean Resources Conservat & Assessment, Silver Spring, MD 20910 USA. RP NOAA, Natl Ocean Serv, Off Ocean Resources Conservat & Assessment, 1305 E West Hwy, Silver Spring, MD 20910 USA. NR 6 TC 95 Z9 102 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD SEP PY 1998 VL 36 IS 9 BP 712 EP 717 DI 10.1016/S0025-326X(98)00049-6 PG 6 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 125GB UT WOS:000076228100019 ER PT J AU Gray, J AF Gray, J TI Major ocean programs, National Oceanic and Atmospheric Administration SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Gray, J (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 1998 VL 32 IS 3 BP 85 EP 87 PG 3 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 148LH UT WOS:000077506400011 ER PT J AU Rasmussen, EN Straka, JM AF Rasmussen, EN Straka, JM TI Variations in supercell morphology. Part 1: Observations of the role of upper-level storm-relative flow SO MONTHLY WEATHER REVIEW LA English DT Article ID PRECIPITATION SEVERE THUNDERSTORMS; SIMULATED CONVECTIVE STORMS; HAIL GROWTH; AIR-FLOW; ROTATION; WIND; MESOCYCLONES; ENVIRONMENTS; TRAJECTORIES; EVOLUTION AB It is hypothesized that the precipitation intensity beneath a supercell updraft is strongly influenced by the amount of hydrometeors that are reingested into the updraft after being transported away in the divergent upper-level flow of the anvil. This paper presents the results of a climatological analysis of soundings associated with three types of isolated supercells having distinctive precipitation distributions, the so-called classic, low-precipitation (LP), and high-precipitation (HP) storms. It is shown that storm-relative flow at 9-10 km above the ground is strongest in the environments of LP storms, and relatively weak in the environments of HP storms, with classic storms occurring in environments with intermediate magnitudes of upper storm-relative flow. It is plausible that comparatively strong flow in the anvil-hearing levels of LP storms transports hydrometeors far enough from the updraft that they are relatively unlikely to be reingested into the updraft, leading to greatly diminished precipitation formation in the updraft itself. Conversely, the weak upper flow near HP storms apparently allows a relatively large number of hydrometeors to return to the updraft, leading to the generation of relatively large amounts of precipitation in the updraft. It also is apparent that thermodynamic factors such as convective available potential energy. low-level mixing ratio, and mean relative humidity are of lesser importance in determining storm type from a climatological perspective, although important variations in humidity may not be well sampled in this study. This climatological analysis does not directly evaluate the stated hypothesis; however, the findings do indicate that further modeling and microphysical observations are warranted. C1 NOAA, NSSL, Cooperat Inst Mesoscale Meteorol Studies, Boulder, CO 80301 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. RP Rasmussen, EN (reprint author), NOAA, NSSL, Cooperat Inst Mesoscale Meteorol Studies, 3450 Mitchell Lane,Bldg 3,Room 2034, Boulder, CO 80301 USA. NR 52 TC 47 Z9 48 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 1998 VL 126 IS 9 BP 2406 EP 2421 DI 10.1175/1520-0493(1998)126<2406:VISMPI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114VE UT WOS:000075629200006 ER PT J AU Ralph, FM Armi, L Bane, JM Dorman, C Neff, WD Neiman, PJ Nuss, W Persson, POG AF Ralph, FM Armi, L Bane, JM Dorman, C Neff, WD Neiman, PJ Nuss, W Persson, POG TI Observations and analysis of the 10-11 June 1994 coastally trapped disturbance SO MONTHLY WEATHER REVIEW LA English DT Article ID STATES WEST-COAST; KELVIN WAVES; NORTHERN CALIFORNIA; MESOSCALE RIDGES; LOWER ATMOSPHERE; WIND REVERSALS; MARINE-LAYER; POTENTIAL VORTICITY; BOUNDARY-LAYER; CATALINA EDDY AB A coastally trapped disturbance (CTD), characterized by southerly flow at the surface on 10-11 June 1994, was observed from the California Eight to Bodega Bay during a field experiment along the California coast. (North-south approximates the coast-parallel direction.) Data from a special observational network of wind profilers, radio acoustic sounding systems, special surface data, balloon ascents, and a research aircraft were used with satellite and synoptic data to explore both the CTD structure and the regional-scale changes before the event. The disruption of the climatological northerly flow along the central California coast, which preconditioned the area for the development of a CTD, began with the eastward movement of a surface high into Washington and Oregon and the amplification of a thermal low in northern California. As with most CTDs in the region, this occurred over the 2-3 days preceding the CTD's initiation. These large-scale changes caused westward advection of warm continental air across much of the California coast, which increased temperatures by 10 degrees-12 degrees C in the layer from 0.4 to 2.0 km above mean sea level (MSL) during the 48 h before southerly how appeared offshore at the surface. The warming reversed the alongshore sea level pressure gradients near the coast by creating a region of pressure falls extending along 600-1000 km of the coast. This also modified the cross-shore pressure gradient and thus the geostrophic alongshore flow. The warming along the coast also increased the strength of the temperature inversion capping the marine boundary layer (MBL) by a factor of 2-4 over 48 h. The synoptic-scale changes also moved the axis of the climatological near-surface, northerly jet much farther offshore from central California and strengthened this jet near the headlands of Gapes Mendocino and Blanco. The development and decay of southerly flow at the surface along the coast coincided roughly with the evolution of a mesoscale low 200 km offshore, and of a coastal ridge roughly 100 km wide. However, the CTD initiation also followed a 500-m thickening of the MBL inversion in the California Eight region where a Catalina eddy was initially present. At surface sites, the CTD was marked by the passage of a pressure trough, followed by a gradual shift to southerly flow and the appearance of clouds. The area of low cloud was not coincident with the region of southerly flow. The transition to southerly flow propagated northward along shore at 11.9 +/- 0.3 m s(-1) on 10 June, stalled for 11-12 h during the part of the diurnal cycle normally characterized by enhanced northerly flow, and then continued propagating northward along shore at 11.6 m s(-1). Both the geostrophic wind and the isallobaric component of the ageostrophic wind were consistent with southerly how at the surface. Southerly flow was observed up to 5 km MSL in this event and in others, which indicates that the synoptic-scale environment of many CTDs in this region may include a deep tropospheric cyclonic circulation or trough offshore. Both cross-shore and alongshore flights performed by a research aircraft documented the CTD structure and showed that the southerly flow extended at least 100 km offshore and appeared first within the MBL inversion as the inversion thickened upward. While the top of the inversion rose, the height of the inversion's base remained almost unchanged. The thickening of the inversion decreased with distance offshore, and there was no significant change in the MBL depth (i.e., the inversion base height), until 12-14 h after the surface wind shift. Thus, it is suggested that two-layer, shallow water idealizations may be unable to represent this phenomenon adequately. Nonetheless. the gradual wind shift, the thickening inversion, and the correlation between southerly flow and a mesoscale coastal pressure ridge are consistent with a coastally trapped Kelvin wave, albeit one with a higher-order vertical structure that can exist in a two-layer model. However. the semipermanent nature of the changes in the MBL and its inversion is more characteristic of a shallowly sloped internal bore. The temperature increase and lack of southerly flow exceeding the northward phase speed are inconsistent with gravity current behavior. C1 NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ N Carolina, Marine Sci Program, Chapel Hill, NC USA. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ralph, FM (reprint author), NOAA, ERL, Environm Technol Lab, Mail Code R-E-ET7,325 Broadway, Boulder, CO 80303 USA. RI Neff, William/E-2725-2010 OI Neff, William/0000-0003-4047-7076 NR 50 TC 34 Z9 35 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 1998 VL 126 IS 9 BP 2435 EP 2465 DI 10.1175/1520-0493(1998)126<2435:OAAOTJ>2.0.CO;2 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114VE UT WOS:000075629200008 ER PT J AU Wittenberg, AT Anderson, JL AF Wittenberg, AT Anderson, JL TI Dynamical implications of prescribing part of a coupled system: Results from a low-order model SO NONLINEAR PROCESSES IN GEOPHYSICS LA English DT Article ID OCEAN-ATMOSPHERE INTERACTION; GENERAL-CIRCULATION MODEL; LOW-FREQUENCY VARIABILITY; PERSISTENT ANOMALIES; DECADAL VARIABILITY; TROPICAL PACIFIC; GCM SIMULATIONS; EL-NINO; SST; PREDICTABILITY AB It is a common procedure in climate modeling to specify dynamical system components from an external source; a prominent example is the forcing of an atmospheric model with observed sea surface temperatures. In this paper, we examine the dynamics of such forced models using a simple prototype climate system. A particular fully-coupled run of the model is designated the "true" solution, and an ensemble of perturbed initial states is generated by adding small errors to the "true" initial state. The perturbed ensemble is then integrated for the same period as the true solution, using both the fully-coupled model and a model in which the ocean is prescribed exactly from the true solution at every time step. Although the prescribed forcing is error-free, the forced-atmosphere ensemble is shown to converge to spurious solutions. Statistical tests show that neither the time-mean state nor the variability of the forced ensemble is consistent with the fully-coupled system. A stability analysis reveals the source of the inconsistency, and suggests that such behavior may be a more general feature of models with prescribed subsystems. Possible implications for model validation and predictability are discussed. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08542 USA. NOAA, GFDL, Princeton, NJ 08542 USA. RP Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08542 USA. RI Wittenberg, Andrew/G-9619-2013 OI Wittenberg, Andrew/0000-0003-1680-8963 NR 46 TC 6 Z9 7 U1 0 U2 0 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1023-5809 J9 NONLINEAR PROC GEOPH JI Nonlinear Process Geophys. PD SEP PY 1998 VL 5 IS 3 BP 167 EP 179 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 247MT UT WOS:000083225100006 ER PT J AU Bowling, DR Turnipseed, AA Delany, AC Baldocchi, DD Greenberg, JP Monson, RK AF Bowling, DR Turnipseed, AA Delany, AC Baldocchi, DD Greenberg, JP Monson, RK TI The use of relaxed eddy accumulation to measure biosphere-atmosphere exchange of isoprene and of her biological trace gases SO OECOLOGIA LA English DT Article DE REA; oak-hickory forest; isoprene; flux; eddy covariance ID CONDITIONAL-SAMPLING TECHNIQUE; WATER-VAPOR EXCHANGE; OXYGEN-ISOTOPE RATIO; FLUX MEASUREMENT; CARBON-DIOXIDE; MICROMETEOROLOGICAL TECHNIQUES; DECIDUOUS FOREST; SULFUR EMISSIONS; CO2; VEGETATION AB The micrometeorological flux measurement technique known as relaxed eddy accumulation (REA) holds promise as a powerful new tool for ecologists. The more popular eddy covariance (eddy correlation) technique requires the use of sensors that can respond at fast rates (IO Hz), and these are unavailable for many ecologically relevant compounds. In contrast, the use of REA allows flux measurement with sensors that have much slower response time, such as gas chromatography and mass spectrometry. In this review, relevant micrometeorological details underlying REA are presented, and critical analytical and system design details are discussed, with the goal of introducing the technique and its potential applications to ecologists. The validity of REA for measuring fluxes of isoprene, a photochemically reactive hydrocarbon emitted by several plant species, was tested with measurements over an oak-hickory forest in the Walker Branch Watershed in eastern Tennessee. Concurrent eddy covariance measurements of isoprene flux were made using a newly available chemiluminesence instrument. Excellent agreement was obtained between the two techniques (r(2) = 0.974, n = 62), providing the first direct comparison between REA and eddy covariance for measuring the Bur rate of a reactive compound. The influence of a bias in vertical wind velocity on the accuracy of REA was examined. This bias has been thought to be a source of significant error in the past. Measurements of normalized bias ((w) over bar/sigma(w)) alone would lead us to think that a large potential error exists at this site. However, with our isoprene data and through simulations of REA with fast-response H2O and CO2 data, we conclude that accurate REA flux measurements can be made even in the presence of a bias in w. C1 Univ Colorado, Dept Environm Populat & Organism Biol, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. RP Bowling, DR (reprint author), Univ Colorado, Dept Environm Populat & Organism Biol, Boulder, CO 80309 USA. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 58 TC 57 Z9 57 U1 1 U2 19 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD SEP PY 1998 VL 116 IS 3 BP 306 EP 315 DI 10.1007/s004420050592 PG 10 WC Ecology SC Environmental Sciences & Ecology GA 121VD UT WOS:000076034600002 PM 28308061 ER PT J AU Eichmiller, FC Marjenhoff, WA AF Eichmiller, FC Marjenhoff, WA TI Fluoride-releasing dental restorative materials SO OPERATIVE DENTISTRY LA English DT Review ID GLASS-IONOMER CEMENT; CONTAINING AMALGAM INVITRO; MICRO-PROBE ANALYSIS; IN-VITRO; ORTHODONTIC APPLIANCES; CLINICAL-EVALUATION; FILLING MATERIALS; SECONDARY CARIES; RESIN; ENAMEL AB In the 1940s, dentists observed that secondary caries was rarely associated with silicate cement restorations. While the relatively stable dimensional properties of those restorations were undoubtedly a factor in this fortunate circumstance, the fact that fluoride was inherent in the composition of the material received the greater credit. By the mid-1980s, a wide variety of fluoride-releasing dental restorative materials were available to dentists and dental consumers, and the cariostatic effect of fluoride ions on enamel caries had been demonstrated in many studies. This paper reviews much of the fluoride-related research conducted on fluoride-releasing amalgam, glass-ionomer cements, composites, primers, sealants, liners, acrylic resins, and orthodontic bracket bonding materials. The need for standardization of test methods is addressed, as is the need for more controlled clinical trials and additional research. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Eichmiller, FC (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 108 TC 34 Z9 36 U1 0 U2 1 PU UNIV WASHINGTON PI SEATTLE PA SCHOOL DENTISTRY SM-57, SEATTLE, WA 98195 USA SN 0361-7734 J9 OPER DENT JI Oper. Dent. PD SEP-OCT PY 1998 VL 23 IS 5 BP 218 EP 228 PG 11 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 117VZ UT WOS:000075804500002 PM 9863442 ER PT J AU McLaughlin, SM Faisal, M AF McLaughlin, SM Faisal, M TI Histopathological alterations associated with Perkinsus spp. infection in the softshell clam Mya arenaria SO PARASITE LA English DT Article DE softshell clam; Perkinsus spp.; histopathology; gills; encapsulation ID RUDITAPES-DECUSSATUS L; ADAMS-ET-REEVE; APICOMPLEXA; SEMIDECUSSATUS AB Softshell clams (Mya arenaria) collected from the Chester River in the upper Chesapeake Bay showed the presence of Perkinsus spp, in similar to 12 % (28/240) Of clams examined. The infection seems to run a mild course with the host prevailing in encapsulating invading parasites. The gills appear to be the major site of infection, however, the parasite was also found in the digestive gland, gonads, and kidneys and occasionally in the tissue and sinuses of adductor muscles. Typically, clusters of protozoal cells were embedded in on amorphous PAS-positive substrate and were surrounded by one or more layers of granulocytes. In heavy infections, both free and encapsulated Perkinsus spp. cells were observed in affected tissue forming aggregations of different sizes. Within the tissues of M. arenaria, the parasite propagated by schizogony. The presence of large encapsulations in vital organs such as the gills and gonads may adversely affect growth and fertility of affected clams. C1 NOAA, Natl Marine Fisheries Serv, Cooperat Oxford Lab, Oxford, MD 21654 USA. Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA. RP McLaughlin, SM (reprint author), NOAA, Natl Marine Fisheries Serv, Cooperat Oxford Lab, 904 S Morris St, Oxford, MD 21654 USA. NR 26 TC 18 Z9 19 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1252-607X EI 1776-1042 J9 PARASITE JI Parasite PD SEP PY 1998 VL 5 IS 3 BP 263 EP 271 PG 9 WC Parasitology SC Parasitology GA 121KY UT WOS:000076014000009 ER PT J AU Kundur, SR Raviv, D AF Kundur, SR Raviv, D TI A vision-based pragmatic strategy for autonomous navigation SO PATTERN RECOGNITION LA English DT Article DE active vision; dynamic vision; visual navigation; collision avoidance ID OPTICAL-FLOW; MOTION FIELD; DEPTH; FOCUS AB This paper presents a novel approach based on active-vision paradigm, for generating local collision-free paths for mobile robot navigation, in indoor as well as outdoor environments. Two measurable visual motion cues that provide some measure for a relative change in range as well clearance between a 3D surface and a visually fixating observer in motion are described. The visual fields associated with the cues can be used to demarcate regions around a moving observer into safe and danger zones of varying degree, which is suitable for making local decisions about the steering as well as speed commands to the vehicle. (C) 1998 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved. C1 Florida Atlantic Univ, Robot Ctr, Boca Raton, FL 33431 USA. Florida Atlantic Univ, Dept Elect Engn, Boca Raton, FL 33431 USA. Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Florida Atlantic Univ, Robot Ctr, Boca Raton, FL 33431 USA. EM ravivd@acc.fau.edu NR 57 TC 5 Z9 6 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0031-3203 EI 1873-5142 J9 PATTERN RECOGN JI Pattern Recognit. PD SEP PY 1998 VL 31 IS 9 BP 1221 EP 1239 DI 10.1016/S0031-3203(97)00151-9 PG 19 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 102PG UT WOS:000074932600003 ER PT J AU Kim, YK Parente, F Marques, JP Indelicato, P Desclaux, JP AF Kim, YK Parente, F Marques, JP Indelicato, P Desclaux, JP TI Failure of multiconfiguration Dirac-Fock wave functions in the nonrelativistic limit SO PHYSICAL REVIEW A LA English DT Article ID GROUND-STATE; IONS AB Multiconfiguration Dirac-Fock (MCDF) wave functions for a specific J quantum number may not reduce to the appropriate nonrelativistic limit for the L and S quantum numbers. Transition probabilities calculated from such MCDF wave functions for spin-forbidden transitions are unreliable. Remedies for this problem are discussed, including the advantages of using nonorthogonal radial orbitals. It is also shown that transition probabilities for weak transitions are sensitive to the way the Breit interaction is introduced. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Lisbon, Ctr Fis Atom, P-1699 Lisbon, Portugal. Univ Lisbon, Dept Fis, P-1699 Lisbon, Portugal. Ecole Normale Super, Lab Kastler Brossel, F-75252 Paris 05, France. Univ Paris 06, UA CNRS 18, F-75252 Paris 05, France. CEA, Direct Sci Mat, F-38054 Grenoble 9, France. RP Kim, YK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Indelicato, Paul/D-7636-2011; Marques, Jose/A-4152-2014; OI Indelicato, Paul/0000-0003-4668-8958; Marques, Jose/0000-0002-3797-3880; Parente, Fernando/0000-0003-4703-0066 NR 11 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 SEP PY 1998 VL 58 IS 3 BP 1885 EP 1888 DI 10.1103/PhysRevA.58.1885 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 116MY UT WOS:000075730200035 ER PT J AU Parks, HV Spain, EM Smedley, JE Leone, SR AF Parks, HV Spain, EM Smedley, JE Leone, SR TI Experimental investigation of the initial-state alignment dependence in the energy pooling process: Ca(4s4p P-3(1))+Ca(4s4p P-3(1))-> Ca(4s4p P-1(1))+Ca(4s(2)) SO PHYSICAL REVIEW A LA English DT Article ID ASSOCIATIVE IONIZATION; ORBITAL ALIGNMENT; CROSS-SECTIONS; VELOCITY DEPENDENCE; ANGULAR-MOMENTUM; POLARIZED ATOMS; COLLISIONS; COHERENCE; GASES; CA AB A pulsed laser investigation is performed to study the detailed effects of electronic angular-momentum alignment on the cross section for the energy-transfer process Ca(4s4p P-3(1)) + Ca(4s4p P-3(1)) -->Ca(4s4p P-1(1)) + Ca(4s(2)). A uniform magnetic field imposed by a set of Helmholtz coils is used to systematically precess the initial state orbitals with a well-defined period, allowing different alignments to be sampled at different time delays after the pulsed laser excites and aligns the Ca(4s4p P-3(1)) states. The polarization effects in this collision process are striking. For example, the cross section for two atoms both in the m(j)=0 magnetic substrate is 13 times larger than the cross section for two atoms that are both in the m(j)=1 (or -1) substrate, where the quantization axis is taken to be along the relative velocity vector of the collision. The initial in-sublevel dependence of this three-vector correlation process can be completely described with eight fundamental parameters, five of which are accurately obtained. In addition, the coarse energy dependence of these parameters is deduced. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 30 TC 6 Z9 6 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1998 VL 58 IS 3 BP 2136 EP 2147 DI 10.1103/PhysRevA.58.2136 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 116MY UT WOS:000075730200065 ER PT J AU Ahmad, NA Wheeler, AA Boettinger, WJ McFadden, GB AF Ahmad, NA Wheeler, AA Boettinger, WJ McFadden, GB TI Solute trapping and solute drag in a phase-field model of rapid solidification SO PHYSICAL REVIEW E LA English DT Article ID DENDRITIC OPERATING STATE; ORDER-PARAMETER; LARGE SUPERCOOLINGS; EUTECTIC GROWTH; CRYSTAL-GROWTH; BINARY-ALLOYS; INTERFACE; COMPUTATION; DIFFUSION; KINETICS AB During rapid solidification, solute may be incorporated into the solid phase at a concentration significantly different from that predicted by equilibrium thermodynamics. This process, known as solute trapping, leads to a progressive reduction in the concentration change across the interface as the solidification rate increases. Theoretical treatments of rapid solidification using traditional sharp-interface descriptions require the introduction of separately derived nonequilibrium models for the behavior of the interfacial temperature and solute concentrations. In contrast, phase-field models employ a diffuse-interface description and eliminate the need to specify interfacial conditions separately. While at low solidification rates equilibrium behavior is recovered, at high solidification rates nonequilibrium effects naturally emerge from these models. In particular, in a previous study we proposed a phase-field model of a binary alloy [A. A. Wheeler et al., Phys. Rev. E 47, 1893 (1993)] in which we demonstrated solute trapping. Here we show that solute trapping is also possible in a simpler diffuse interface model. We show that solute trapping occurs when the solute diffusion length D-I/V is comparable to the diffuse interface thickness. Here V is the interface velocity and D-I characterizes the solute diffusivity in the interfacial region. We characterize the dependence of the critical speed for solute trapping on the equilibrium partition coefficient k(E) that shows good agreement with experiments by Aziz and co-workers [see M. J. Aziz, Metall. Mater. Trans. A 27, 671 (1996)]. We also show that in the phase-held model, there is a dissipation of energy in the interface region resulting in a solute drag, which we quantify by determining the relationship between the interface temperature and velocity. C1 Univ Southampton, Fac Math Studies, Southampton SO17 1BJ, Hants, England. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ahmad, NA (reprint author), Univ Sains Malaysia, Sch Math Sci, 11800 Minden, Penang, Malaysia. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 53 TC 128 Z9 131 U1 2 U2 30 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 SEP PY 1998 VL 58 IS 3 BP 3436 EP 3450 DI 10.1103/PhysRevE.58.3436 PN B PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 121HM UT WOS:000076007400027 ER PT J AU Lee, C Gido, SP Poulos, Y Hadjichristidis, N Tan, NB Trevino, SF Mays, JW AF Lee, C Gido, SP Poulos, Y Hadjichristidis, N Tan, NB Trevino, SF Mays, JW TI pi-shaped double-graft copolymers: effect of molecular architecture on morphology SO POLYMER LA English DT Article; Proceedings Paper CT Symposium on Metastability and Critical Phenomena in Polymers and Polymer Phase Transitions at the Spring Materials-Research-Society Meeting CY 1997 CL SAN FRANCISCO, CALIFORNIA SP Mat Res Soc DE block copolymer; graft copolymer; morphology ID STAR BLOCK-COPOLYMERS; MICROPHASE SEPARATION; CONFORMATIONAL ASYMMETRY; STYRENE; EQUILIBRIUM; ISOPRENE; DIBLOCK AB The morphologies formed by block copolymers with a double-graft, pi or (S,I)I'(S,I) architecture were investigated using transmission electron microscopy (TEM) and small angle neutron scattering (SANS). Here S and I represent blocks of polystyrene and polyisoprene, respectively. These materials were synthesized using anionic polymerization and chlorosilane linking, and they were characterized using size exclusion chromatography, membrane osmometry, and low-angle laser light scattering. This characterization work confirmed the desired molecular architectures and narrow molecular weight distributions. The results of morphological characterization indicate that one can understand complex grafting architectures by decomposing them into fundamental building blocks, which are taken as the component single-graft structures out of which the larger structure is constructed. We propose rules for dividing structures into these components, which we call constituting block copolymers. For the a double-graft architecture, the constituting block copolymer is an asymmetric single-graft block copolymer. The morphological behaviour of the more complex double-graft architecture is approximately equivalent to that of the constituting single-graft block copolymer. Through the use of the constituting block copolymers we map the experimentally determined morphological behaviour of eight materials with a architecture onto the morphology diagram calculated by Milner for miktoarm stars. As in our previous study of asymmetric single-graft block copolymers, the asymmetry of the graft location along the backbone requires a generalization of the molecular asymmetry parameter, epsilon, used in the calculated morphology diagram. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Massachusetts, Dept Polymer Sci & Engn, M Keck Electron Microscopy Lab, Amherst, MA 01003 USA. Univ Athens, Dept Chem, Athens 15771, Greece. Inst Elect Struct & Laser, Heraklion 71110, Crete, Greece. USA, Polymers Res Branch, Res Lab, APG, Gaithersburg, MD USA. NIST, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Univ Alabama, Dept Chem, Birmingham, AL 35294 USA. RP Gido, SP (reprint author), Univ Massachusetts, Dept Polymer Sci & Engn, M Keck Electron Microscopy Lab, Amherst, MA 01003 USA. NR 32 TC 57 Z9 57 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD SEP PY 1998 VL 39 IS 19 BP 4631 EP 4638 PG 8 WC Polymer Science SC Polymer Science GA ZZ543 UT WOS:000074740500018 ER PT J AU Wong-Ng, W Toby, B Greenwood, W AF Wong-Ng, W Toby, B Greenwood, W TI Crystallographic studies of BaR2ZnO5 (R=La, Nd, Dy, Ho, Er, and Y) SO POWDER DIFFRACTION LA English DT Article ID BOND-VALENCE PARAMETERS; BA-CU-O; CRYSTAL-STRUCTURE; OXIDES; DIFFRACTION; SUPERCONDUCTIVITY; ZINC AB The crystal structures of BaR2ZnO5, where R=La, Nd, Dy, Ho, and Y, were studied by neutron diffraction, and that of the Er analog was investigated by synchrotron X-ray diffraction. Two structure types were confirmed for this series of compounds and agreed with those reported in literature. The compounds with a smaller size of R (R=Dy, Ho, Y, and Er) are isostructural to the orthorhombic "green phase (BaY2CuO5)" compounds. The cell parameters for compounds with the R=Er to Dy range from a = 7.0472(1) Angstrom to 7.0944(1) Angstrom, b = 12.3022(1) Angstrom to 12.3885(2) Angstrom, and c = 5.6958(1) Angstrom to 5.7314(1) Angstrom, respectively. R is 7-fold coordinated inside a monocapped trigonal prism. These prisms share edges to form wavelike chains parallel to the long b-axis. The Ba atoms reside in Ii-fold coordinated cages. The compounds which contain a larger size R (R=La and Nd) crystallize in the tetragonal I4/mcm space group, but are not isostructural to the "brown phases" BaR2CuO5. The lattice parameters for the La and Nd analogs are a = 6.9118(1) Angstrom, c = 11.6002(2) Angstrom for BaLa2ZnO5, and a = 6.7608(1) Angstrom and c = 11.5442(2) Angstrom for BaLa2ZnO5. The structure consists of ZnO4 tetrahedral groups (instead of planar CuO4 groups as found in the brown phase) with Ba ions inserted in between. The structure can be viewed as consisting of alternate layers of Zn-Ba-O and Nd-O extending infinitely in the xy plane and perpendicular to the z-axis. (C) 1998 International Centre for Diffraction Data. [S0885-7156(98)00201-2] C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Wong-Ng, W (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 33 TC 9 Z9 10 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD SEP PY 1998 VL 13 IS 3 BP 144 EP 151 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA 120LF UT WOS:000075957300005 ER PT J AU Kaduk, JA Toby, BH Wong-Ng, W Greenwood, W AF Kaduk, JA Toby, BH Wong-Ng, W Greenwood, W TI Crystal structure and reference X-ray pattern of Ba4Ti10Al2O27 SO POWDER DIFFRACTION LA English DT Article ID BOND-VALENCE PARAMETERS AB The crystal structure of Ba4Ti10Al2O27 has been refined in a joint Rietveld refinement using neutron and X-ray powder data. The compound crystallizes in the monoclinic space group C2/m, with a = 19.7057(3), b = 11.3575(2), c = 9.8318(2) Angstrom, beta = 109.218(1)degrees, and V = 2077.81(5) Angstrom(3). It is isostructural to Ba4Ti10Fe2O27 and Ba4Ti11ZnO27, and consists of a complex network of corner- and edge-sharing Ti/Al octahedra. The structure can best be described based on close-packed O/Ba-O layers in an 8-layer (8L) chhcchhc sequence. Out of a total of ten Ti/Al sites, Al was found to substitute for Ti mainly in four sites, and the remaining six sites were predominantly occupied by Ti. The unit cell contents derived from the refined site occupancies are Ba16Ti40.48Al7.52O108, essentially identical to the expected Ba16Ti40Al8O108. A reference diffraction pattern of this phase is also reported. (C) 1998 International Centre for Diffraction Data. [S0885-7156(98)00103-1] C1 Amoco Corp, Naperville, IL 60566 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Geol, College Pk, MD 20742 USA. RP Kaduk, JA (reprint author), Amoco Corp, Naperville, IL 60566 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 10 TC 3 Z9 3 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD SEP PY 1998 VL 13 IS 3 BP 178 EP 184 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA 120LF UT WOS:000075957300013 ER PT J AU Tatarskii, VI AF Tatarskii, VI TI An intuitive introduction to the Wolf effect SO PURE AND APPLIED OPTICS LA English DT Article AB The physics of the Wolf shift is described without complicated mathematics. C1 Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. RP Tatarskii, VI (reprint author), Univ Colorado, CIRES, 325 Broadway, Boulder, CO 80303 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-9659 J9 PURE APPL OPT JI Pure Appl. Opt. PD SEP PY 1998 VL 7 IS 5 BP 953 EP 957 DI 10.1088/0963-9659/7/5/005 PG 5 WC Optics SC Optics GA 122ZU UT WOS:000076102000005 ER PT J AU Berger, MJ AF Berger, MJ TI Applicability of the condensed-random-walk Monte Carlo method at low energies in high-Z materials SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Electron and Photon Transport Theory Applied to Dose Calculation CY JUN 02-05, 1997 CL SEATTLE, WASHINGTON ID 10-100 KEV ELECTRONS; BACKSCATTERING; SIMULATION; TRANSPORT; MATTER; SOLIDS; FILMS AB The predictions of several Monte Carlo codes were compared with each other and with experimental results pertaining to the penetration of through gold foils of electrons incident with energies from 128 to 8 keV. The main purpose was to demonstrate that reflection and transmission coefficients, for number and energy, can be estimated reliably with a simple Monte Carlo code based on the condensed-random-walk and continuous-slowing-down approximations. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NIST, Gaithersburg, MD 20899 USA. RP Berger, MJ (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 27 TC 5 Z9 5 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD SEP PY 1998 VL 53 IS 3 BP 191 EP 203 DI 10.1016/S0969-806X(98)00101-7 PG 13 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 100LQ UT WOS:000074817900002 ER PT J AU Piehler, MF Currin, CA Cassanova, R Paerl, HW AF Piehler, MF Currin, CA Cassanova, R Paerl, HW TI Development and N-2-fixing activity of the benthic microbial community in transplanted Spartina alterniflora marshes in North Carolina SO RESTORATION ECOLOGY LA English DT Article ID SALT-MARSH; ORGANIC-CARBON; FOOD-WEBS; NITROGEN; RESTORATION; DENITRIFICATION; PHOSPHORUS; MITIGATION; ESTUARIES; ISOTOPES AB Growth and maturation of transplanted salt marshes is often limited by the availability of nitrogen (N). We examined the role of N-2-fixing benthic microbial assemblages (microalgae and associated bacteria) in two restored marshes (l-year-old and 6-year-old marsh) and a natural salt marsh in the Newport River Estuary, North Carolina. Benthic N, fixation (nitrogenase activity NA), chlorophyll a (Chl a concentration, Spartina alterniflora (smooth cordgrass) stem counts, and sediment organic matter content were determined in the three marshes. Significant differences were observed between sites for both Chi a and NA. The 1-year-old marsh always exhibited the highest levels of NA and Chi a. Sediment organic matter content was lowest in the 1-year-old marsh (similar to 2%), intermediate in the 6-year-old marsh (similar to 5%), and highest in the natural marsh (similar to 10%). Carbon and nitrogen analyses were also performed on the 1-year-old marsh sediments, which were depleted in N. a positive correlation was observed between surface sediment N and Chi a. Remineralized, microbially derived N may provide growth-limiting inorganic N to Spartina transplants. N-2-fixing microbial assemblages in the 1-year-old marsh may also be an important food source for marsh infauna. Benthic N-2-fixing microbial assemblages play a key role in the N economy of restored salt marshes. C1 Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. NOAA, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. Univ N Carolina, Pembroke, NC 28372 USA. RP Piehler, MF (reprint author), Univ N Carolina, Inst Marine Sci, 3431 Arendell St, Morehead City, NC 28557 USA. RI Piehler, Michael/C-3844-2011 NR 38 TC 33 Z9 35 U1 3 U2 12 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1061-2971 J9 RESTOR ECOL JI Restor. Ecol. PD SEP PY 1998 VL 6 IS 3 BP 290 EP 296 DI 10.1046/j.1526-100X.1998.00633.x PG 7 WC Ecology SC Environmental Sciences & Ecology GA 119XJ UT WOS:000075927800008 ER PT J AU Smith, TD AF Smith, TD TI "Simultaneous and complementary advances": mid-century expectations of the interaction of fisheries science and management SO REVIEWS IN FISH BIOLOGY AND FISHERIES LA English DT Editorial Material DE bioeconomics; fisheries management; fisheries science; fisheries regulation; International Whaling Commission; resource management; whales ID COMMUNITY MANAGEMENT; SCIENTIFIC INQUIRY; CONSERVATION; CHAOS; COMPLEXITY; PRINCIPLES AB The simultaneous development of fisheries science and fisheries management that Ray Beverton and Sydney Holt envisioned in 1957 is argued not to have occurred over the past 40 years. The causes of the many failures of fisheries management have been too frequently a matter of informal debate, and almost never a matter of scientific testing of hypotheses. A broader scope for fisheries science is suggested that would be required as a basis for testing hypotheses about the causes of the failure of "simultaneous and complementary advances" of the science and management of fisheries. The history of the science and management of the International Whaling Commission is used as an example of the scientific scope required to adequately test hypothesized causes of the failures of fisheries management, and to emphasize the relevance of such testing to evaluating the likely success of current management proposals. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Smith, TD (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. EM Tim.Smith@noaa.gov NR 58 TC 10 Z9 10 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0960-3166 J9 REV FISH BIOL FISHER JI Rev. Fish. Biol. Fish. PD SEP PY 1998 VL 8 IS 3 BP 335 EP 348 DI 10.1023/A:1008823503867 PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 147NG UT WOS:000077486400007 ER PT J AU Schachlbauer, H Weiss, SM AF Schachlbauer, H Weiss, SM TI EBU/SMPTE Task Force for harmonized standards for the exchange of program material as bit streams - Final report: Analysis and results SO SMPTE JOURNAL LA English DT Article C1 Soc Mot Picture & Televis Engineers, White Plains, NY USA. Microsoft Corp, Redmond, WA 98052 USA. Turner Entertainment Net, Atlanta, GA USA. IBM Corp, Armonk, NY 10504 USA. RAI, Turin, Italy. BT, Ipswich, Suffolk, England. MS NBC, Ft Lee, NJ USA. ECI Telecom, Altamonte Springs, FL USA. SGI, Houston, TX USA. BBC, London, England. Turner Broadcasting Syst, Atlanta, GA USA. Apple Corp, Cupertino, CA USA. Quantel, Newbury, Berks, England. JVC, Yokohama, Kanagawa, Japan. CNN R&D, Atlanta, GA USA. Sony BPE, New York, NY USA. Avid, Tewksbury, MA USA. Sony Corp, New York, NY USA. UCL, Louvain, Belgium. IRT, Munich, Germany. Tektronix Inc, Beaverton, OR USA. BT Labs, Ipswich, Suffolk, England. Gennum, Burlington, ON, Canada. Warner Bros, Burbank, CA USA. Panason Bcast, Secaucus, NJ USA. Sun Microsyst Inc, Mt View, CA USA. Hitachi, Hitachi, Ibaraki, Japan. Paramont Pics, Los Angeles, CA USA. SMPTE, White Plains, NY USA. Chicago Tribune, Chicago, IL 60611 USA. NIST, Gaithersburg, MD USA. Artel Video, Marlborough, MA USA. FH Wiesbaden, Wiesbaden, Germany. Matsushita Res Inst Tokyo Inc, Tokyo, Japan. NBC, New York, NY USA. Matrox, Dorval, PQ, Canada. Artel Video Syst, Marlborough, MA USA. Digital Media Technol, Nashville, TN USA. ABC TV, New York, NY USA. Utah Sci, Salt Lake City, UT USA. Thomson CSF, Alexandria, VA USA. Cypress SC, San Jose, CA USA. Silicon Graph, Mt View, CA USA. EE Times, White Plains, NY USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU SOC MOTION PICTURE TV ENG INC PI WHITE PLAINS PA 595 WEST HARTSDALE AVE, WHITE PLAINS, NY 10607 USA SN 0036-1682 J9 SMPTE J JI SMPTE J. PD SEP PY 1998 VL 107 IS 9 BP 605 EP 815 PG 247 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Imaging Science & Photographic Technology; Telecommunications SC Engineering; Instruments & Instrumentation; Imaging Science & Photographic Technology; Telecommunications GA 127KL UT WOS:000076350100003 ER PT J AU Potts, JC Manooch, CS Vaughan, DS AF Potts, JC Manooch, CS Vaughan, DS TI Age and growth of vermilion snapper from the southeastern United States SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID RHOMBOPLITES-AURORUBENS; RED GROUPER; SIZE; MORTALITY AB A comprehensive aging study of vermilion snapper, Rhomboplites aurorubens, was conducted, using 1,465 otoliths collected between 1991 and 1995 from the commercial and head-boat fisheries from North Carolina through the Florida Keys. An additional 19 otoliths came from fishery-independent samples from the South Atlantic Eight for fish smaller than 254 mm total length (TL), which is the legal size limit. Marginal increment analysis revealed that rings on the otoliths were deposited annually. This observation is further substantiated by the increasing modal radius of each age ring corresponding to the increasing modal size of the fish at age. Observed ages ranged from age 1 (202 mm mean TL) to age 14 (535 mm TL). The largest fish was 600 mm TL and was estimated to be age 13. The weight-length relationship was described by the equation: W = 9.55 X 10(-9)(L)(3.04), where W = whole weight in kilograms and L = total length in millimeters. The von Bertalanffy equation was estimated using the inverse, weighted, backcalculated lengths at the last annulus. The equation was L-t = 650 (1-e(-0.144(t+0.238))), where t is age in years. C1 Beaufort Lab, SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Beaufort, NC 28516 USA. RP Potts, JC (reprint author), Beaufort Lab, SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 24 TC 19 Z9 20 U1 1 U2 3 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1998 VL 127 IS 5 BP 787 EP 795 DI 10.1577/1548-8659(1998)127<0787:AAGOVS>2.0.CO;2 PG 9 WC Fisheries SC Fisheries GA 142JY UT WOS:000077198200009 ER PT J AU Hartwell, SI Jordahl, DM Dawson, CEO Ives, AS AF Hartwell, SI Jordahl, DM Dawson, CEO Ives, AS TI Toxicity of scrap tire leachates in estuarine salinities: Are tires acceptable for artificial reefs? SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article AB Shredded scrap tires were leached in a modified toxicity characteristic leaching procedure (TCLP) extraction method in synthetic saltwater solutions for three sequential 7-d periods. Test salinities were 5, 15, and 25 parts per thousand. Acute toxicity tests were conducted with larval sheepshead minnows Cyprinodon variegatus and daggerblade grass shrimp Palaemonetes pugio. Mortality decreased following multiple sequential leaching periods. Toxicity decreased with increasing salinity. The fish were more sensitive than the grass shrimp. Dilution series toxicity bioassays were performed with fish and grass shrimp at 5 parts per thousand salinity and at 15 parts per thousand with fish only. The 96-h LC50s (lethal concentration for half of the test animals) for fish were 10% leachate at 5 parts per thousand and 26% at 15 parts per thousand. The 96-h LC50 for grass shrimp at 5 parts per thousand was 63%. The 96-h lowest observed effect concentrations (LOEC) for fish survival were 12.5% at 5 parts per thousand and 25% at 15 parts per thousand. The 96-h LOEC for grass shrimp survival was 50% at 5 parts per thousand. Growth LOEC values were 12.5% at both salinities for fish and 50% for grass shrimp at 5 parts per thousand. Chemical analyses revealed no specific components as the cause of observed toxicity. Antagonism between sea salt and toxic chemicals is hypothesized to cause differential toxicity at varying salinities, as opposed to differential solubility of the toxicants. Extrapolation of laboratory results indicates that proposed tire reefs should not pose a serious threat to water quality in Chesapeake Bay. No observed effects concentrations (NOEC) were an order of magnitude or greater above field concentrations calculated from simplified methods. Toxic substances appear to leach from the surface of the tires not from the tire matrix. The use of tires in higher salinity environments appears to pose little direct toxicological risk to resident organisms. However, because unknown toxic chemicals were present in leachates at all test salinities, no assessment can be made regarding persistence, fate, transport, or possible bioaccumulative effects. C1 Maryland Dept Nat Resources, Tidewater Adm, Chesapeake Bay Res & Monitoring Div, Annapolis, MD 21401 USA. RP Hartwell, SI (reprint author), NOAA, Natl Marine Fisheries Serv, 1315 E West Highway F HC, Silver Spring, MD 20910 USA. NR 38 TC 19 Z9 19 U1 1 U2 11 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1998 VL 127 IS 5 BP 796 EP 806 DI 10.1577/1548-8659(1998)127<0796:TOSTLI>2.0.CO;2 PG 11 WC Fisheries SC Fisheries GA 142JY UT WOS:000077198200010 ER PT J AU Van Doornik, DM Winans, GA AF Van Doornik, DM Winans, GA TI Inheritance of allozymes in coho salmon SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID CHINOOK SALMON; PACIFIC-NORTHWEST; GENETIC-BASIS; CHUM SALMON; LOCI; DEHYDROGENASE; VARIABILITY AB We examined allozyme variation in the parents and offspring of 41 crossings of coho salmon Oncorhynchus kisutch. Mendelian inheritance previously unreported for Pacific salmon was confirmed at 11 loci: sAAT-4*, sAH*, ALAT*, EST-1*, beta GALA*, GAPDH-2*, GPI-B2*, sMDH-A1,2*, PEPA*, PEPC*, and PNP-1*. Independent assortment was found for the following locus pairs: ADA-1* and beta GALA*, ALAT* and beta GALA*, ALAT* and EST-1*, EST-1* and beta GALA*, EST-1* and PEPC*, GAPDH-2* and PNP-1*, beta GALA* and GPI-B2*, beta GALA* and sMDH-A1,2*, and beta GALA* and PEPC*. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Van Doornik, DM (reprint author), Natl Marine Fisheries Serv, POB 130, Manchester, WA 98353 USA. EM don.vandoornik@noaa.gov NR 29 TC 2 Z9 2 U1 2 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1998 VL 127 IS 5 BP 833 EP 837 DI 10.1577/1548-8659(1998)127<0833:IOAICS>2.0.CO;2 PG 5 WC Fisheries SC Fisheries GA 142JY UT WOS:000077198200014 ER PT J AU Sissenwine, MP Mace, PM Powers, JE Scott, GP AF Sissenwine, MP Mace, PM Powers, JE Scott, GP TI A commentary on western Atlantic bluefin tuna assessments SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Editorial Material AB Intense fishing for bluefin tuna Thunnus thynnus in the western Atlantic Ocean began in the 1960s, when landings peaked at nearly 20,000 metric tons (mt). During the 1970s, landings averaged about 5,000 mt. The International Commission for the Conservation of Atlantic Tunas (ICCAT) established a total allowable catch (TAC) of 1,160 mt in 1982 and has set limits ranging from 1,995 to 2,660 mt annually since. The Commission's assessments indicate that unrestricted fishing through the 1960s and 1970s resulted in a sharp decline in abundance, primarily because heavy fishing on young fish wasted potentially good recruitment. Since the late 1980s, ICCAT management has stabilized the western Atlantic population, and recently there are signs of improvement. Resource assessments and management of western Atlantic bluefin tuna are subjects of severe controversy. Two of the most controversial issues are the stock assessment implications of fish migrations between the western and eastern Atlantic management units and the strategies for rebuilding abundance in the western Atlantic. In 1994, the U.S. National Research Council (NRC) was commissioned to review bluefin tuna stock assessments with particular emphasis on the issue of population mixing. The NRC report was widely misinterpreted as being more optimistic than it really was for the western population. Analyses by the NRC committee indicated that the abundance of spawning age fish in the west was higher than the value estimated in the 1993 ICCAT assessment but also that recruitment in the western Atlantic had failed so badly that some year-classes were estimated to have zero fish. Projections of future population size based on the NRC analyses indicated that recent levels of catch could not have been sustained. The critical issue now facing fishery managers is how to rebuild the population to a size, estimated to be about eight times the current size, that can produce maximum sustainable yield. One strategy (referred to as "active") is to reduce the fishing mortality, which would permit some immediate rebuilding and enhance the likelihood of better recruitment in the future. Another strategy (referred to as "passive") is to wait for natural variability in recruitment to bring a fortuitously strong year-class that would be invested in rebuilding, rather than in harvest. The most recent ICCAT assessment evaluated rebuilding strategies, but the method used has limitations that should be understood before decisions about rebuilding are made. C1 Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. Natl Marine Fisheries Serv, Miami, FL 33149 USA. RP Sissenwine, MP (reprint author), Natl Marine Fisheries Serv, 166 Water St, Woods Hole, MA 02543 USA. NR 35 TC 28 Z9 28 U1 3 U2 12 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1998 VL 127 IS 5 BP 838 EP 855 DI 10.1577/1548-8659(1998)127<0838:ACOWAB>2.0.CO;2 PG 18 WC Fisheries SC Fisheries GA 142JY UT WOS:000077198200015 ER PT J AU Bond, NA Stabeno, PJ AF Bond, NA Stabeno, PJ TI Analysis of surface winds in Shelikof Strait, Alaska, using moored buoy observations SO WEATHER AND FORECASTING LA English DT Article ID EDDY-RESOLVING MODEL; GULF; GAP; CIRCULATION; SHELF; LEE AB The winds within Shelikof Strait, Alaska, have been examined using hourly observations from a pair of meteorological buoys moored at the ends of the strait for a 6-month period in 1994. The focus is on periods of gap winds, when the prominent terrain bordering Shelikof Strait constrains the low-level winds to accelerate down the local pressure gradient in a direction approximately parallel to the axis of the strait. Statistics have been amassed on the performance of a simple, Bernoulli-type gap wind model during periods of downstrait (northeasterly) gap flow. A series of model experiments have been conducted to elucidate the processes important to gap flow in Shelikof Strait. The model best predicts the observed alongstrait component of the wind at the exit of the strait (explaining 74% of the variance) when it includes not just surface friction, but also parameterizations of the Coriolis effect due to the cross-strait wind and of entrainment. The latter process is studied further using upper-air soundings collected at Kodiak, Alaska, immediately upstream of the strait. These observations suggest that the entrainment is driven largely by the vertical wind shear at the top of the gap flow. Gap winds are favored more during downstrait flow than during upstrait (southwesterly) flow. The lower terrain on the Kodiak island side of the strait may often represent an insufficient sidewall for upstrait gap flow, as suggested by the detailed observations from a NOAA P-3 research aircraft flight in May 1996 during upstrait flow. Examination of ECMWF operational analyses for the period of buoy observations shows that the alongstrait pressure gradient was represented adequately but the surface winds were handled poorly. The gap wind model presented here could aid operational forecasting of winds in Shelikof Strait, using coarse-resolution analyses or numerical model output for its input, and could be adapted for other regions with similar topography. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. RP Bond, NA (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 19 TC 10 Z9 10 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 547 EP 559 DI 10.1175/1520-0434(1998)013<0547:AOSWIS>2.0.CO;2 PN 1 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HC UT WOS:000076513300003 ER PT J AU Businger, S Birchard, T Kodama, K Jendrowski, PA Wang, JJ AF Businger, S Birchard, T Kodama, K Jendrowski, PA Wang, JJ TI A bow echo and severe weather associated with a kona low in Hawaii SO WEATHER AND FORECASTING LA English DT Article ID TROPICAL SQUALL-LINE; CONVECTIVE STORMS; NUMERICAL SIMULATIONS; DOPPLER RADAR; REAR-INFLOW; EVOLUTION; PRECIPITATION; MESOSCALE; SYSTEMS; COPT-81 AB On 2 November 1995 a kona low formed to the northwest of Hawaii. During the following 48 h a series of convective rainbands developed on the southeastern side of the low as it slowly moved eastward. On the afternoon of 3 November 1995 Hawaiian standard time (HST), a bow-echo signature was identified in the reflectivity observations from the recently installed WSR-88D located on the south shore of Kauai, and led to the first severe thunderstorm warning ever issued by the National Weather Service Forecast Office in Honolulu, Hawaii. Subsequent to the warning, winds of 40 m s(-1) (80 kt) were observed at Nawiliwili Harbor on the southeast side of Kauai. The goals of this paper were to (i) document, within the constraints of the observational data, the synoptic and mesoscale environment associated with the formation of the bow echo and severe weather in Hawaii and contrast them with investigations of similar phenomena in the midlatitudes and Tropics, and (ii) provide a discussion of the implications of the availability of data from the new WSR-88D radars in Hawaii to operational forecasting of severe weather in the central Pacific. C1 Univ Hawaii, Dept Meteorol, Honolulu, HI 96822 USA. Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. Natl Weather Serv, Forecast Off, Honolulu, HI USA. UCAR COMET Outreach Program, Boulder, CO USA. RP Businger, S (reprint author), Univ Hawaii, Dept Meteorol, 2525 Correa Rd, Honolulu, HI 96822 USA. NR 51 TC 15 Z9 17 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 576 EP 591 DI 10.1175/1520-0434(1998)013<0576:ABEASW>2.0.CO;2 PN 1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HC UT WOS:000076513300005 ER PT J AU Hufford, GL Kelley, HL Sparkman, W Moore, RK AF Hufford, GL Kelley, HL Sparkman, W Moore, RK TI Use of real-time multisatellite and radar data to support forest fire management SO WEATHER AND FORECASTING LA English DT Article ID CHANNEL AB Combined digital data from multiple satellites and Doppler radar can provide fire weather meteorologists and resource managers with accurate information on forest fire location, intensity, growth, smoke plumes, and associated mesoscale weather. An integrated application using real-time satellite and radar is described for the Miller's Reach forest fire that occurred in south-central Alaska in June 1996. Generated data and products were made available immediately on-scene via point-to-point high-speed portable satellite communications. This fire consumed over 15 000 ha and destroyed 344 structures. C1 Natl Weather Serv, NOAA, Alaska Reg, Anchorage, AK 99513 USA. Litton PRC Inc, Anchorage, AK USA. RP Hufford, GL (reprint author), Natl Weather Serv, NOAA, Alaska Reg, 222 W 7th Ave,23, Anchorage, AK 99513 USA. NR 13 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 592 EP 605 DI 10.1175/1520-0434(1998)013<0592:UORTMA>2.0.CO;2 PN 1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HC UT WOS:000076513300006 ER PT J AU Dierking, CF AF Dierking, CF TI Effects of a mountain wave windstorm at the surface SO WEATHER AND FORECASTING LA English DT Article ID SEVERE DOWNSLOPE WINDS AB A mountain wave windstorm in 1993 is documented for the Taku River Valley near Juneau, Alaska. The mountain wave produces a mesoscale pressure response that appears to enhance local gap flow and complicates efforts to separate the two forcing mechanisms. In addition, the Nested Grid Model is evaluated in terms of its ability to predict atmospheric structure favorable for the development of a mountain wave, since current model resolutions are not small enough to predict the event itself. In the 1993 case, numerical guidance is shown to have some value in the prediction of an atmospheric state conducive to the development of the windstorm. C1 Natl Weather Serv, Forecast Off, Juneau, AK 99801 USA. RP Dierking, CF (reprint author), Natl Weather Serv, Forecast Off, POB 32179, Juneau, AK 99801 USA. NR 11 TC 8 Z9 8 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 606 EP 616 DI 10.1175/1520-0434(1998)013<0606:EOAMWW>2.0.CO;2 PN 1 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HC UT WOS:000076513300007 ER PT J AU Pielke, RA Landsea, CW AF Pielke, RA Landsea, CW TI Normalized hurricane damages in the United States: 1925-95 SO WEATHER AND FORECASTING LA English DT Article ID ATLANTIC HURRICANES; INSURANCE INDUSTRY; INTENSE AB Hurricanes are the costliest natural disasters in the United States. Understanding how both hurricane frequencies and intensities vary from year to year as well as how this is manifested in changes in damages that occur is a topic of great interest to meteorologists, public and private decision makers, and the general public alike. Previous research into long-term trends in hurricane-caused damage along the U.S. coast has suggested that damage has been quickly increasing within the last two decades, even after considering inflation. However, to best capture the year-to-year variability in tropical cyclone damage, consideration must also be given toward two additional factors: coastal population changes and changes in wealth. Both population and wealth have increased dramatically over the last several decades and act to enhance the recent hurricane damages preferentially over those occurring previously. More appropriate trends in the United States hurricane damages can be calculated when a normalization of the damages are done to take into account inflation and changes in coastal population and wealth. With this normalization, the trend of increasing damage amounts in recent decades disappears. Instead, substantial multidecadal variations in normalized damages are observed: the 1970s and 1980s actually incurred less damages than in the preceding few decades. Only during the early 1990s does damage approach the high level of impact seen back in the 1940s through the 1960s, showing that what has been observed recently is not unprecedented. Over the long term, the average annual impact of damages in the continental United States is about $4.8 billion (1995 $), substantially more than previous estimates. Of these damages, over 83% are accounted for by the intense hurricanes (Saffir-Simpson categories 3, 4, and 5), yet these make up only 21% of the U.S.-landfalling tropical cyclones. C1 Natl Ctr Atmospher Res, Environm & Soc Impacts Grp, Boulder, CO 80307 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Pielke, RA (reprint author), Natl Ctr Atmospher Res, Environm & Soc Impacts Grp, POB 3000, Boulder, CO 80307 USA. NR 23 TC 233 Z9 235 U1 3 U2 39 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 621 EP 631 DI 10.1175/1520-0434(1998)013<0621:NHDITU>2.0.CO;2 PN 2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400002 ER PT J AU Kelley, JGW Hobgood, JS Bedford, KW Schwab, DJ AF Kelley, JGW Hobgood, JS Bedford, KW Schwab, DJ TI Generation of three-dimensional lake model forecasts for Lake Erie SO WEATHER AND FORECASTING LA English DT Article ID NCAR MESOSCALE MODEL; GREAT-LAKES; SIMULATION; WEATHER; TESTS; PENNSYLVANIA; TEMPERATURE; CIRCULATION; CLIMATE; LAYER AB A one-way coupled atmospheric-lake modeling system was developed to generate short-term, mesoscale lake circulation, water level, and temperature forecasts for Lake Erie, The coupled system consisted of the semi-operational versions of the Pennsylvania State University-National Center for Atmospheric Research three-dimensional, mesoscale meteorological model (MM4), and the three-dimensional lake circulation model of the Great Lakes Forecasting System (GLFS). The coupled system was tested using archived MM4 36-h forecasts for three cases during 1992 and 1993. The cases were chosen to demonstrate and evaluate the forecasts produced by the coupled system during severe lake conditions and at different stages in the lake's annual thermal cycle. For each case, the lake model was run for 36 h using surface heat and momentum fluxes derived from MM4's hourly meteorological forecasts and surface water temperatures from the lake model, Evaluations of the lake forecasts were conducted by comparing forecasts to observations and lake model hindcasts. Lake temperatures were generally predicted well by the coupled system. Below the surface, the forecasts depicted the evolution of the lake's thermal structure: although not as rapidly as in the hindcasts. The greatest shortcomings were in the predictions of peak water levels and times of occurrence. The deficiencies in the lake forecasts were related primarily to wind direction errors and underestimation of surface wind speeds by the atmospheric model. The three cases demonstrated both the potential and limitations of daily high-resolution lake forecasts for the Great Lakes. Twice daily or more frequent lake forecasts are now feasible for Lake Erie with the operational implementation of mesoscale atmospheric models such as the U.S. National Weather Service's Eta Model and Rapid Update Cycle. C1 Ohio State Univ, Atmospher Sci Program, Columbus, OH 43210 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Kelley, JGW (reprint author), Natl Ocean Serv, Coast Surg Dev Lab, N-CS13,Room 7875,1315 EW Highway, Silver Spring, MD 20910 USA. RI Schwab, David/B-7498-2012 NR 58 TC 16 Z9 16 U1 2 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 659 EP 687 DI 10.1175/1520-0434(1998)013<0659:GOTDLM>2.0.CO;2 PN 2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400005 ER PT J AU Blier, W AF Blier, W TI The sundowner winds of Santa Barbara, California SO WEATHER AND FORECASTING LA English DT Article ID DOWNSLOPE WINDSTORMS AB Significant downslope wind and warming events periodically occur along a short segment of the southern California coast in the vicinity of Santa Barbara. This region is characterized by a unique mesoscale topography: over a length of about 100 km the coastline is oriented approximately west-east, with the adjoining narrow coastal plain bounded by a steeply rising (to elevations greater than 1200 m) and coast-parallel mountain range. Called Sundowner winds because they often begin in the late afternoon or early evening, their onset is typically associated with a rapid rise in temperature and decrease in relative humidity. In the most extreme Sundowner wind events, wind speeds can be of gale force or higher, and temperatures over the coastal plain, and even at the coast itself, can rise significantly above 37.8 degrees C (100 degrees F). In addition to causing a dramatic change from the more typical marine-influenced local weather conditions, Sundowner wind episodes have resulted in Significant property and agricultural damage, as well as extreme fire danger. They have, in fact, been associated with many of the most destructive conflagrations that have occurred in the Santa Barbara region. In the present study, three different Sundowner wind episodes are examined. These include midsummer and midautumn events primarily manifested by extremely warm temperatures, and a winter season event notable for its damaging winds. The associated meteorological conditions are examined, and possible physical mechanisms responsible for these episodes are discussed. In at least two of the three cases considered here, mountain wave development appears to have played a significant role. C1 Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. RP Blier, W (reprint author), Natl Weather Serv, 21 Grace Hopper Ave,Bldg 712, Monterey, CA 93943 USA. NR 20 TC 9 Z9 10 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 702 EP 716 DI 10.1175/1520-0434(1998)013<0702:TSWOSB>2.0.CO;2 PN 2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400007 ER PT J AU Medlin, JM Croft, PJ AF Medlin, JM Croft, PJ TI A preliminary investigation and diagnosis of weak shear summertime convective initiation for extreme southwest Alabama SO WEATHER AND FORECASTING LA English DT Article ID SEA; SIMULATION; DYNAMICS; FLORIDA; BREEZES; STORMS; LINES; RADAR; FLOW AB The initiation and location of summer season convective activity, occurring between 1500 and 1800 UTC within a 100-km radius of the Mobile, Alabama, National Weather Service WSR-88D radar site, was examined on days when weak vertical wind shear environments existed. Data were collected during June and July of 1996 based on 1200 UTC analyses of upper-air charts, radar, and GOES-8 satellite imagery. Thirteen case days were selected for detailed analysis. The precise location of initiation was found to be a function of both the 0-1-km base-slate flow and the extent of the flow's interaction with physiographic features and local sea- and bay-breeze circulations. The modified mean 1800 UTC sounding for case days was characterized by a well-mixed boundary layer, a deep moist-adiabatic lapse rate, and an overall decrease in relative humidity with height, For all case days, the surface parcel was found to be the most unstable air parcel within the mixed layer. A distinct bimodal distribution was found to exist in the 0-1-km base-state wind flow pattern with flow predominantly east-southeast or west-southwest. Thunderstorms were observed to initiate in a "mirror image" pattern on either side of Mobile Bay and were focused near elevation peaks, along the sea breeze, and at or near the orthogonal intersection of the sea- and bay-breeze circulations on either side of the bay. C1 Natl Weather Serv, Mobile, AL 36608 USA. Jackson State Univ, Jackson, MS 39217 USA. RP Medlin, JM (reprint author), Natl Weather Serv, 8400 Airport Blvd,Bldg 11, Mobile, AL 36608 USA. NR 20 TC 11 Z9 12 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 717 EP 728 DI 10.1175/1520-0434(1998)013<0717:APIADO>2.0.CO;2 PN 2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400008 ER PT J AU Camp, J Watson, AI Fuelberg, HE AF Camp, J Watson, AI Fuelberg, HE TI The diurnal distribution of lightning over north Florida and its relation to the prevailing low-level flow SO WEATHER AND FORECASTING LA English DT Article ID SOUTHEAST UNITED-STATES; CLIMATOLOGY; FEATURES; CLOUD AB Six years (1989-94) of cloud-to-ground lightning data are used to examine the distribution of lightning across the Florida panhandle and adjacent coastal waters and its relationship to the prevailing low-level flow. Only warm season data between 1 May and 31 October are used. The prevailing flow is determined by subdividing the low-level (1000-700 mb) vector mean wind into categories that are either parallel or perpendicular to various parts of the coastline. Moderate wind speeds (2-5 m s(-1)) generally are found to be more conducive to producing lightning than stronger speeds. Wind speeds stronger than 5 m s(-1) likely inhibit the formation of the sea breeze, the main focus for summertime thunderstorms in the region. Onshore, offshore, and parallel flows are found to play important roles in determining the patterns of flash locations in each flow regime. The complexity of the coastline also is found to have a major impact on the hash distributions. The prevailing wind direction is shown to be related to the time of peak afternoon lightning occurrence as well as the frequency of nighttime storms. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Natl Weather Serv, Tallahassee, FL USA. RP Fuelberg, HE (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NR 13 TC 13 Z9 13 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 729 EP 739 DI 10.1175/1520-0434(1998)013<0729:TDDOLO>2.0.CO;2 PN 2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400009 ER PT J AU Marzban, C AF Marzban, C TI Scalar measures of performance in rare-event situations SO WEATHER AND FORECASTING LA English DT Article ID FORECAST VERIFICATION; DIAGNOSTIC VERIFICATION; SKILL AB A set of 14 scalar, nonprobabilistic measures-some old, some new-is examined in the rare-event situation. The set includes measures of accuracy, association, discrimination, bias, and skill. It is found that all measures considered herein are inequitable in that they induce under- or overforecasting. One condition under which such bias is not induced (for some of the measures) is when the underlying class-conditional distributions are Gaussian (normal) and equivariant. C1 Natl Severe Storms Lab, Cooperat Inst Mesoscale & Meteorol Studies, Norman, OK 73069 USA. Univ Oklahoma, Dept Phys, Norman, OK 73019 USA. RP Marzban, C (reprint author), Natl Severe Storms Lab, Cooperat Inst Mesoscale & Meteorol Studies, 1313 Halley Circle, Norman, OK 73069 USA. NR 14 TC 63 Z9 64 U1 2 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 753 EP 763 DI 10.1175/1520-0434(1998)013<0753:SMOPIR>2.0.CO;2 PN 2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400011 ER PT J AU Powell, MD Rinard, SK AF Powell, MD Rinard, SK TI Marine forecasting at the 1996 Centennial Olympic Games SO WEATHER AND FORECASTING LA English DT Article ID SUMMER OLYMPICS; CLIMATOLOGY AB A team of meteorologists from the United States, Canada, and Australia provided marine weather support to the sailing events of the 1996 Centennial Olympic Games, held in Wassaw Sound near Savannah, Georgia. The team conducted research on the weather and climate and developed a set of forecast products designed to inform athletes. volunteers, and race managers of the wind, tidal current, wave, and weather behavior expected each day during the pre-Olympic and Olympic periods. The Olympic period proved to be a challenge with thunderstorms delaying, abandoning, or postponing races on half of the days. Thunderstorm development and movement was linked to the timing and strength of the sea breeze as well as the direction and speed of the gradient wind. Numerous thunderstorm warnings were issued with the assistance of the WSR-88D radar and the Warning Decision Support System. Frequent lightning was a legitimate safety concern due to the long distances between race courses and lack of suitable shelter; fortunately no one was injured during the lightning episodes. Forecasters benefited from access to a variety of monitoring tools and models including real-time Olympic buoy wind and current time series displays; satellite and radar imagery animation; 2-, 8-, and 10-km resolution mesoscale models; a live video feed of race coverage; and communications with forecasters aboard patrol craft offshore. Official wind forecasts, mesoscale models, and a simple vector addition model performed better than climatology and persistence as defined by mean vector error and rms wind direction error. Climatology was difficult to beat on the basis of wind speed error. C1 NOAA, Atlantic Oceanog & Meteorol Lab, HRD, Miami, FL 33149 USA. NOAA, NWS, So Reg Headquarters, Ft Worth, TX USA. RP Powell, MD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, HRD, 4301 Rickenbacker Cswy, Miami, FL 33149 USA. RI Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 24 TC 6 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 764 EP 782 DI 10.1175/1520-0434(1998)013<0764:MFATCO>2.0.CO;2 PN 2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400012 ER PT J AU Markowski, PM Rasmussen, EN Straka, JM AF Markowski, PM Rasmussen, EN Straka, JM TI The occurrence of tornadoes in supercells interacting with boundaries during VORTEX-95 SO WEATHER AND FORECASTING LA English DT Article ID SQUALL LINES; THUNDERSTORMS; VORTICITY; ROTATION; BEHAVIOR; MESONET; STORMS AB During the Verifications of the Origins of Rotation in Tornadoes Experiment, nearly 70% of the significant tornadoes occurred near low-level boundaries not associated with the forward or rear flank downdrafts of supercells. In general, these were preexisting boundaries readily identified using conventional data sources, Most of the tornadoes occurred on the cool side of these low-level boundaries and generally within 30 km of the boundaries. It is likely that the low-level boundaries augmented the "ambient" horizontal vorticity, which, upon further generation in the forward-flank region, became sufficient to be associated with tornadic low-level mesocyclones. Some implications for forecasting and further research are discussed. C1 Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Boulder, CO USA. RP Markowski, PM (reprint author), Univ Oklahoma, Sch Meteorol, 100 E Boyd St,Room 1310, Norman, OK 73019 USA. EM marko@rossby.ou.edu OI Markowski, Paul/0000-0002-4295-3390 NR 27 TC 88 Z9 90 U1 2 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 852 EP 859 DI 10.1175/1520-0434(1998)013<0852:TOOTIS>2.0.CO;2 PN 2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400018 ER PT J AU Blanchard, DO AF Blanchard, DO TI Assessing the vertical distribution of convective available potential energy SO WEATHER AND FORECASTING LA English DT Article ID THUNDERSTORM; CUMULONIMBUS; STORMS AB Comparisons of convective available potential energy (CAPE) with standard instability indices for evaluating the convective potential of the atmosphere such as the lifted index (LI) reveal only moderate correlations. This is because the LI is a measure of single-level buoyancy while CAPE is a measure df both integration depth and the buoyancy. Normalizing the CAPE values by the depth over which the integration takes place provides an index (NCAPE) that is independent of the depth and is a convenient measure of the mean parcel buoyancy. This normalization effectively distinguishes between environments with similar CAPE but exhibiting different buoyancy and integration depth. Also, because the vertical distribution of CAPE can have an important effect on convective updraft strength, it is advantageous to vertically partition CAPE and NCAPE into multiple layers. NCAPE may provide a more useful indicator of buoyancy in environments in which the depth of free convection is shallow and total CAPE is small. It is suggested that NCAPE computations be used in combination with CAPE for evaluation of convective potential. C1 NOAA, NSSL, Boulder, CO 80303 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP NOAA, NSSL, 325 Broadway, Boulder, CO 80303 USA. EM blanch@ucar.edu NR 23 TC 52 Z9 57 U1 0 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 EI 1520-0434 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 870 EP 877 DI 10.1175/1520-0434(1998)013<0870:ATVDOC>2.0.CO;2 PN 2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400020 ER PT J AU Grumbine, RW AF Grumbine, RW TI Virtual floe ice drift forecast model intercomparison SO WEATHER AND FORECASTING LA English DT Article ID PACK ICE AB Both sea ice forecast models and methods to measure their skill are needed for operational sea ice forecasting: Two simple sea ice models are described and tested here. Four different measures of skill are also tested. The forecasts from the newer sea ice model are found to perform better, regardless of the skill measure used. All four skill measures show essentially the same behavior, in terms of having no dependence on season and being roughly constant. All four measures also agree that there is no decline in skill with time through the 6-day period of forecast. C1 Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. RP Grumbine, RW (reprint author), Natl Ctr Environm Predict, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI Grumbine, Robert/B-9865-2008 NR 10 TC 6 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1998 VL 13 IS 3 BP 886 EP 890 DI 10.1175/1520-0434(1998)013<0886:VFIDFM>2.0.CO;2 PN 2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 130HD UT WOS:000076513400023 ER PT J AU Kim, S Ledbetter, H AF Kim, S Ledbetter, H TI Low-temperature elastic coefficients of polycrystalline indium SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE Debye characteristic temperature; elastic constants; Gruneisen parameter; indium; internal friction; low temperatures; Marx oscillator; pulse-echo method AB Using an ultrasonic pulse-echo method, we measured the elastic coefficients of polycrystalline indium from 300 to 5 K. All elastic coefficients showed regular temperature behavior, as predicted by an Einstein-oscillator model. The sheer and Young moduli showed the largest change, increasing approximate to 55% during cooling. The Poisson ratio was unusually high at 0.45, just below the theoretical upper bound of 0.5. Using a Marx composite oscillator, we measured the internal friction at room temperature. We calculated the acoustic Debye temperature, 108.4 K, that agreed well with a monocrystal acoustic value, 111.3 K and the specific-heat value, 108.8 K. Also, we calculated the Gruneisen parameters, gamma(L) = 2.04, gamma(H) = 2.68, that agreed well with the specific-heat value, gamma = 2.48 and the shock-wave value, gamma = 2.24. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Natl Inst Stand & Technol, US Dept Commerce, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Kim, S (reprint author), Natl Inst Stand & Technol, US Dept Commerce, Mat Sci & Engn Lab, 325 Broadway, Boulder, CO 80303 USA. NR 13 TC 17 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 31 PY 1998 VL 252 IS 1 BP 139 EP 143 DI 10.1016/S0921-5093(98)00490-0 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 108HV UT WOS:000075261000016 ER PT J AU Sari, N Holden, MJ Mayhew, MP Vilker, VL Coxon, B AF Sari, N Holden, MJ Mayhew, MP Vilker, VL Coxon, B TI Exploration of the structural environment of the iron-sulfur cluster in putidaredoxin by nitrogen-15 NMR spectroscopy of selectively labeled cysteine residues SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID 2-IRON FERREDOXINS; OXIDIZED PUTIDAREDOXIN; MAGNETIC-RESONANCE; SPINACH FERREDOXIN; PSEUDOMONAS-PUTIDA; FE2S2 FERREDOXIN; H-1-NMR SPECTRA; H-1 RESONANCES; IDENTIFICATION; ANABAENA-7120 AB Putidaredoxin is a di-iron protein whose paramagnetic region is not well characterized by H-1 detected NMR. We have studied the structure of this region in greater detail by directly observed N-15 NMR of oxidized and reduced putidaredoxin preparations in which the six cysteine residues are selectively labeled with N-15. A new method for preparation of a stable form of reduced putidaredoxin has been developed for use in NMR. The N-15 NMR spectra of the oxidized and reduced forms are characteristically different, and we have measured and compared N-15 chemical shifts, spin-lattice relaxation times (T-1), and chemical shift/temperature dependences for both forms. Evidence for localized valencies of the iron atoms in the reduced form is presented. From the N-15 T-1 values of the oxidized form, reduced distances of the cysteine backbone N-15 nuclei from the center of the Fe2S2 cluster have been calculated. These distances are consistent with those calculated from X-ray crystal structure data for five ferredoxins, and confirm the structural similarity of the Fe2S2 clusters in putidaredoxin and in these ferredoxins in the oxidized state. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Coxon, B (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 33 TC 5 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD AUG 28 PY 1998 VL 249 IS 3 BP 773 EP 780 DI 10.1006/bbrc.1998.9227 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 116XV UT WOS:000075751100036 PM 9731212 ER PT J AU Yap, WT AF Yap, WT TI Mathematical analyses of ac voltammetry of a surface confined redox process SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE input/output phase relations; ac voltammetry; redox process ID ELECTRON-TRANSFER RATE; GOLD ELECTRODE; SPECTROSCOPY AB Analytical expressions were derived for the harmonics of the current response to an ac voltage input, when the rate-determining process is a redox reaction of a couple confined to the electrode surface. Some input/output phase relations such as functions of the heterogeneous electron transfer rate and the re-organization energy are illustrated. (C) 1998 Elsevier Science S.A. All rights reserved. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Yap, WT (reprint author), NIST, Div Biotechnol, Chem Bldg,Room A353, Gaithersburg, MD 20899 USA. NR 13 TC 4 Z9 4 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD AUG 28 PY 1998 VL 454 IS 1-2 BP 33 EP 38 DI 10.1016/S0022-0728(98)00253-8 PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 121KV UT WOS:000076013700004 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Processes regulating cellular metal accumulation and physiological effects: Phytoplankton as model systems SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE membrane transport of metals; phytoplankton; cellular metal accumulation; metal toxicity ID DIATOM THALASSIOSIRA-WEISSFLOGII; CATHODIC STRIPPING VOLTAMMETRY; NATURAL ORGANIC-LIGANDS; CENTRAL NORTH PACIFIC; COASTAL DIATOM; SARGASSO-SEA; PHYTOCHELATIN PRODUCTION; MARINE-PHYTOPLANKTON; COPPER COMPLEXATION; TRACE-METALS AB Trace metals exist in a variety of redox states and coordination species which markedly influences their geochemical behavior and biological availability. Most exist in natural waters as metal cations that are complexed to varying degrees by inorganic and organic ligands. Metal ions are generally taken up into cells by membrane transport proteins designed for acquisition of nutrient metals (Mg, Fe, Mn, Zn, Co, Cu, Mo). Organic ligands compete with these transport proteins for binding metal ions, and consequently, organic complexation substantially decreases metal uptake rates. Typically, the chelated metal is not directly available for cellular uptake, and metal uptake is controlled by either the concentration of free aquo ions or that of kinetically labile inorganic species. The coordination sites of transport proteins, however, are not entirely specific for intended nutrient metals, and consequently will bind with and transport non-nutritive or toxic metals. Competition for membrane transport sites and for intracellular metabolic binding sites can substantially influence the uptake of both nutrient and toxic metals and resultant effects on growth rate. Such growth rate effects provide feedback on cellular metal concentrations since the amount of metal accumulated within cells represents a balance between the rate of metal uptake and the cellular growth rate, the effective biodilution rate. Phytoplankton have provided useful model systems for investigating the processes and associated chemical and biological factors regulating cellular metal accumulation and resultant physiological effects. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. RP Sunda, WG (reprint author), NOAA, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. NR 65 TC 224 Z9 248 U1 4 U2 53 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD AUG 28 PY 1998 VL 219 IS 2-3 BP 165 EP 181 DI 10.1016/S0048-9697(98)00226-5 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA 129HH UT WOS:000076457400006 ER PT J AU Feingold, G Kreidenweis, SM Zhang, YP AF Feingold, G Kreidenweis, SM Zhang, YP TI Stratocumulus processing of gases and cloud condensation nuclei - 1. Trajectory ensemble model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; FRACTIONAL CLOUDINESS; OXIDATION; AEROSOLS; SO2; MICROPHYSICS; CHEMISTRY; RADIATION; DROPLETS; GROWTH AB Aqueous-phase processing of gases and of the cloud condensation nucleus (CCN) spectrum is addressed using a trajectory ensemble model. We first derive a set of boundary layer parcel trajectories from a large-eddy simulation model (LES) and then use this trajectory set for subsequent cloud microphysical/chemical studies. We explore this approach in the stratocumulus-capped marine boundary layer and show examples of aqueous-phase processing of gases and CCN. The microphysical model is a Lagrangian parcel model that is driven by the thermodynamic and kinematic fields produced by the LES and calculates CCN deliquescence and droplet growth by condensation on a moving mass grid. It is coupled with a sulfate chemistry model that treats oxidation of S(IV) to S(VI) via ozone and hydrogen peroxide for a size-resolved droplet spectrum. The model reproduces the observed (and previously modeled) aqueous processing of particles that leads to growth of CCN and lowering of their critical supersaturations. Results show that important information on parcel in-cloud residence times and boundary layer mixing timescales can be gleaned from this approach. By averaging the results of 500 parcel trajectories, a more representative picture of CCN and gas processing is obtained compared with that derived from a single parcel simulation representing average conditions. Finally, processed CCN spectra are used as input to a coupled microphysical/dynamical cloud-resolving model, and it is suggested that cloud processing may either enhance or suppress drizzle formation, depending on the concentration and sixes of the CCN. C1 NOAA, Environm Technol Lab, Cooperat Inst Res Atmosphere, Boulder, CO 80303 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Feingold, G (reprint author), NOAA, Environm Technol Lab, Cooperat Inst Res Atmosphere, 325 Broadway, Boulder, CO 80303 USA. EM gfein-gold@etl.noaa.gov RI Feingold, Graham/B-6152-2009; Kreidenweis, Sonia/E-5993-2011 OI Kreidenweis, Sonia/0000-0002-2561-2914 NR 48 TC 53 Z9 53 U1 1 U2 6 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 AUG 27 PY 1998 VL 103 IS D16 BP 19527 EP 19542 DI 10.1029/98JD01750 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114ED UT WOS:000075595400008 ER PT J AU Hicke, J Tuck, A Smith, W AF Hicke, J Tuck, A Smith, W TI A comparison of Antarctic stratospheric radiative heating rates calculated from high-resolution interferometer sounder and UK Meteorological Office data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POLAR VORTEX; OZONE; MODEL; SYSTEM; COMPUTATIONS; TRANSPORT; DYNAMICS; DESCENT; BALANCE; CLOUDS AB Radiative heating rates have been calculated in the region of the Antarctic polar vortex during 1994 using the National Center for Atmospheric Research Community Climate Model (CCM2) radiative transfer model. Temperature and tropospheric water vapor retrievals were used from the high-resolution interferometer sounder (HIS) on board the ER-2 in 1994 to compute clear sky heating rates in April, August, and October. The lower stratospheric heating rate is shown to be sensitive to the skin temperature due to the exchange of radiation within the ozone 9.6 mu m band. This implies a coupling between the surface and the lower stratosphere, with the formation of sea ice decreasing the skin temperature and increasing lower stratospheric cooling rates. Computations show weak heating (strong cooling) rates for the fall flight, of the order of -0.7 K/day (potential temperature), with progressively greater heating (smaller cooling) rates associated with the late winter and spring flights and large variations in latitude. HIS temperatures are independent of numerical weather prediction analyses and so provide a useful comparison. Vertical mean (350-420 K) temperature differences between HIS retrievals and collocated U.K. Meteorological Office (UKMO) assimilations are generally within 3 K; HIS temperatures are greater for most flights around and poleward of the vortex edge. Calculated heating rates result in weaker HIS heating (stronger HIS cooling) for most flights resulting from the greater HIS temperatures. Heating rate differences are generally within 0.2 K/day for the 350-420 K vertical mean. The calculations show evidence of a minimum in the cooling rate in the region of the vortex edge for the August and October flights, also seen in the collocated UKMO results as well as in hemispheric calculations. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. RP Hicke, J (reprint author), NOAA, Aeron Lab, 325 Broadway,R-E-AL6, Boulder, CO 80303 USA. EM jhicke@al.noaa.gov; tuck@al.noaa.gov RI Tuck, Adrian/F-6024-2011; Hicke, Jeff/M-9677-2013 OI Tuck, Adrian/0000-0002-2074-0538; NR 38 TC 4 Z9 4 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 AUG 27 PY 1998 VL 103 IS D16 BP 19691 EP 19707 DI 10.1029/98JD01368 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114ED UT WOS:000075595400020 ER PT J AU Kinne, S Bergstrom, R Toon, OB Dutton, E Shiobara, M AF Kinne, S Bergstrom, R Toon, OB Dutton, E Shiobara, M TI Clear-sky atmospheric solar transmission: An analysis based on FIRE 1991 field experiment data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL AB We consider explanations for disagreements between models and measurements of clear-sky solar transmission. Data from four cloud-free days during the FIRE 1991 field experiment are studied. Our model simulations of solar broadband fluxes exceed measurements by about 10%. About half of this discrepancy occurs in the near-infrared spectral region. About half of this discrepancy can be linked to the direct irradiance. These deviations suggest (1) model under estimates in near-infrared trace-gas absorption and (2) errors in visible diffuse fluxes. The near-infrared error in other models is generally less than the one associated with our model. Other models suggest more trace-gas absorption. However, variations among models are so large that they swamp current measurement errors such as uncertainties of the water vapor column. The visible diffuse flux error cannot be easily explained. We illustrate that a poor cosine response of solar flux instruments could have contributed. Also, underestimates of aerosol absorption could be a factor. There is clearly a need for measurements and comparisons at high spectral resolution to better quantify the sources of these errors. However, these comparisons will only be fruitful if we have confidence in the accuracy of our models and the accuracy of the data. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Boulder, CO 80303 USA. Bay Area Environm Res, San Francisco, CA 94122 USA. MRI Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. Univ Colorado, LASP, Boulder, CO 80309 USA. RP Kinne, S (reprint author), NASA, Goddard Space Flight Ctr, Code 923, Greenbelt, MD 20771 USA. EM kinne@spamer.gsfc.nasa.gov NR 14 TC 23 Z9 23 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 AUG 27 PY 1998 VL 103 IS D16 BP 19709 EP 19720 DI 10.1029/98JD01540 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114ED UT WOS:000075595400021 ER PT J AU Mazur, V Shao, XM Krehbiel, PR AF Mazur, V Shao, XM Krehbiel, PR TI "Spider" lightning in intracloud and positive cloud-to-ground flashes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIO INTERFEROMETRIC OBSERVATIONS AB The nature of visible, horizontally stratified lightning channels propagating over large distances near the cloud base during the decaying stage of a storm (also called "spider" lightning) was investigated. The study was effectuated through the use of the coordinated observations of a VHF interferometer, a high-speed image-intensified video system, measurements of electric and magnetic fields, and optical transients. Spider-lightning events were found to be negative leaders similar to stepped leaders in negative cloud-to-ground flashes, with a similar average speed of propagation horizontally of 2-4 x 10(5) m s(-1) Being slow negative leaders, spider-lightning events are part of intracloud flashes and positive cloud-to-ground flashes occurring prior to and during the inverted (fair weather polarity) phase of the End of the Storm Oscillation in the ground electric field. Spider lightning is characterized by both the pulsing luminosity at the tips of its branched channels and the continuous luminosity (for tens to hundreds of milliseconds) which is maintained by the continuing current flow. The interferometer produced mapping of radiation sources closely resembling the spider-lightning channels (negative leaders) but only;a weak trace of radiation sources associated with positive leaders to ground. Both the video images and a few radiation sources of positive leaders were obtained within 1 ms of the leader's ground attachment. The interferometer, however, failed to map fast negative leaders that occurred intermittently during the spider-lightning events. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. New Mexico Inst Min & Technol, Socorro, NM 87801 USA. RP Mazur, V (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM mazur@nssl.noaa.gov NR 20 TC 62 Z9 63 U1 1 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 AUG 27 PY 1998 VL 103 IS D16 BP 19811 EP 19822 DI 10.1029/98JD02003 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 114ED UT WOS:000075595400028 ER PT J AU Restrepo-Cossio, AA Gonzalez, CA Mari, F AF Restrepo-Cossio, AA Gonzalez, CA Mari, F TI Comparative ab initio treatment (Hartree-Fock, density functional theory, MP2, and quadratic configuration interactions) of the cycloaddition of phosphorus ylides with formaldehyde in the gas phase SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID WITTIG OLEFINATION REACTION; ELECTRON-TRANSFER; MOLECULAR-STRUCTURE; MNDO-PM3 TREATMENT; PHOSPHINE OXIDES; MECHANISM; STEREOSELECTIVITY; ABINITIO; STEREOCHEMISTRY; BENZALDEHYDE AB In this study we describe the results of the application of several ab initio methods to the reactions in the gas phase of four unstabilized ylides (H3P=CH2, H2MeP=CH2, HMe2P=CH2, and Me3P=CH2) with formaldehyde to form their respective oxaphosphetanes. At the HF level, H3P=CH2 and H2MeP=CH2 proceeded to the formation of oxaphosphetane. However, at the B3LYP, MP2, and QCISD levels, these ylides react by a nucleophilic attack of the ylidic carbon on the carbonyl group, concomitant with the proton abstraction from the phosphorus atom to form 2-phosphinoethanol. This unusual dependence of the reaction path on the level of theory indicates that H3P=CH2, the most popular ylide for modeling the Wittig reaction, is atypical and raises questions regarding its use as a suitable model for more realistic systems. At all levels of theory (HF, B3LYP, and MP2), the reactions of HMe2P=CH2 and Me3P=CH2 with formaldehyde proceed in a cycloaddition-like fashion to yield oxaphosphetanes. The calculated barriers for these processes varied considerably with the level of correlation and the basis sets employed. The geometries of reactants, intermediates, transition states, and products did not change significantly with the level of theory or basis set employed. The use of B3LYP or MP2 calculations with the 6-31G* basis set is a reasonable compromise between computational expense and level of rigor to describe the Wittig reaction. Our results suggest that for alkyl-substituted ylides, HF geometries along the reaction profile resemble the ones obtained with B3YLP and MP2 methods. Therefore, the Wittig reaction can be properly described at the ab initio level using B3YLP or MP2 single-point energies on the respective HF geometries. C1 Florida Atlantic Univ, Dept Chem & Biochem, Boca Raton, FL 33431 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Mari, F (reprint author), Florida Atlantic Univ, Dept Chem & Biochem, 777 Glades Rd, Boca Raton, FL 33431 USA. NR 63 TC 18 Z9 18 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 27 PY 1998 VL 102 IS 35 BP 6993 EP 7000 DI 10.1021/jp981085h PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 116UX UT WOS:000075744300017 ER PT J AU Das, TN Neta, P AF Das, TN Neta, P TI Reduction potentials of naphthoxyl and pyridoxyl radicals in aqueous solutions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID O-H BONDS; PHENOXYL RADICALS; PULSE-RADIOLYSIS; ELECTRON; ENERGIES AB Reduction potentials of 1- and 2-naphthoxyl, 2-, 3-, and 4-pyridoxyl, and 4-phenylphenoxyl radicals in alkaline aqueous solutions are determined by pulse radiolysis. The potential of 1-naphthoxyl is determined to be 0.59 V versus NHE from the redox equilibrium involving l-naphthol, 3-methylphenol, and their radicals. The reduction potential of the 3-methylphenoxyl radical (0.73 V) is obtained from its equilibrium with the phenoxyl radical. The potential for 2-naphthoxyl (0.69 V) is obtained from equilibrium with the phenoxyl radical. The reduction potentials of the three pyridoxyl radicals are measured from equilibria with the 4-cyanophenoxyl radical. The values are found to be 1.18 V for 2-pyridoxyl, 1.06 V for 3-pyridoxyl, and 1.24 V for 4-pyridoxyl. The reduction potential of 4-phenylphenoxyl radical (0.93 V) is obtained from equilibrium with the I-2(.-) radical. From these reduction potentials and the known pK(a) values of the phenolic compounds, we estimate the O-H bond dissociation energies. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Neta, P (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 22 TC 23 Z9 23 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 27 PY 1998 VL 102 IS 35 BP 7081 EP 7085 DI 10.1021/jp981930w PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 116UX UT WOS:000075744300029 ER PT J AU Hall, DS Matthews, MR Ensher, JR Wieman, CE Cornell, EA AF Hall, DS Matthews, MR Ensher, JR Wieman, CE Cornell, EA TI Dynamics of component separation in a binary mixture of Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLECTIVE EXCITATIONS; OUTPUT COUPLER; ATOMS; GAS; COLLAPSE AB We describe the first experiments that study in a controlled way the dynamics of distinguishable and interpenetrating bosonic quantum fluids. We work with a two-component system of Bose-Einstein condensates in the \F = 1, m(f) = -1> and \2, 1> spin states of Rb-87. The two condensates are created with complete spatial overlap, and in subsequent evolution they undergo complex relative motions that tend to preserve the total density profile. The motions quickly damp out, leaving the condensates in a steady state with a non-negligible (and adjustable) overlap region. C1 Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Hall, DS (reprint author), Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. NR 38 TC 655 Z9 658 U1 7 U2 21 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 AUG 24 PY 1998 VL 81 IS 8 BP 1539 EP 1542 DI 10.1103/PhysRevLett.81.1539 PG 4 WC Physics, Multidisciplinary SC Physics GA 112FJ UT WOS:000075483200001 ER PT J AU Hall, DS Matthews, MR Wieman, CE Cornell, EA AF Hall, DS Matthews, MR Wieman, CE Cornell, EA TI Measurements of relative phase in two-component Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM PHASE; ATOMS; INTERFERENCE; DECOHERENCE; COHERENCE; DIFFUSION; GAS AB We have measured the relative phase of two Bose-Einstein condensates using a time-domain, separated-oscillatory-field condensate interferometer. A single two-photon coupling pulse prepares the double-condensate system with a well-defined relative phase; at a later time, a second pulse reads out the phase difference accumulated between the two condensates. We find that the accumulated phase difference reproduces from realization to realization of the experiment, even after the individual components have separated spatially and their relative center-of-mass motion has damped. C1 Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Hall, DS (reprint author), Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. NR 35 TC 369 Z9 375 U1 4 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 24 PY 1998 VL 81 IS 8 BP 1543 EP 1546 DI 10.1103/PhysRevLett.81.1543 PG 4 WC Physics, Multidisciplinary SC Physics GA 112FJ UT WOS:000075483200002 ER PT J AU Antonucci, JM Skrtic, D Eanes, ED AF Antonucci, JM Skrtic, D Eanes, ED TI Bioactive polymeric composites based on hybrid amorphous calcium phosphates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, ADAHF, PRC, Gaithersburg, MD 20899 USA. NIDR, Bethesda, MD 20892 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 405-POLY BP U121 EP U121 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100402 ER PT J AU Barnes, JD AF Barnes, JD TI Lamellar versus supramolecular scattering in semi-crystalline polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 181-PMSE BP U868 EP U868 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002610 ER PT J AU Bauer, BJ Topp, A Tomalia, DA Amis, EJ AF Bauer, BJ Topp, A Tomalia, DA Amis, EJ TI Effect of solvent quality on the molecular dimensions of PAMAM dendrimers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Michigan Mol Inst, Midland, MI 48640 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 185-PMSE BP U869 EP U869 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002614 ER PT J AU Bauer, BJ Topp, A Tomalia, DA Amis, EJ AF Bauer, BJ Topp, A Tomalia, DA Amis, EJ TI Effect of solvent quality on the molecular dimensions of PAMAM dendrimers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Michigan Mol Inst, Midland, MI 48640 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 139-PMSE BP U854 EP U854 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002568 ER PT J AU Bianco-Peled, H Dori, Y Scheider, J Tirrell, M Sung, LP Satija, S AF Bianco-Peled, H Dori, Y Scheider, J Tirrell, M Sung, LP Satija, S TI Structure of dense polymer brushes at the air-water interface SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 364-PHYS BP U767 EP U767 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002304 ER PT J AU Bowman, CN Lovell, LG Syrpes, DS Stansbury, JW AF Bowman, CN Lovell, LG Syrpes, DS Stansbury, JW TI Dimethacrylate dental resins: The effect of comonomer on the polymerization kinetics. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Bowman, Christopher/B-1490-2008 OI Bowman, Christopher/0000-0001-8458-7723 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 418-POLY BP U125 EP U125 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100415 ER PT J AU Braiewa, RJ Weiss, RA Karim, A Ankner, J AF Braiewa, RJ Weiss, RA Karim, A Ankner, J TI Neutron reflectivity of polymer blends. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Missouri, Res Reactor Facil, Columbia, MO 65211 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 120-PMSE BP U848 EP U848 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002549 ER PT J AU Burden, DL AF Burden, DL TI Novel chemical measurements: From molecular fluorescence to elctrophysiology and back. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 192-ANYL BP U196 EP U196 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234900537 ER PT J AU Butler, PD Hamilton, WA Magid, LJ Sommer, C Schurtenberger, P Slawecki, TM Hayter, JB AF Butler, PD Hamilton, WA Magid, LJ Sommer, C Schurtenberger, P Slawecki, TM Hayter, JB TI Effect of fluid flow on surfactant aggregates near a solid wall. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. ETH Zurich, Inst Polymere, CH-8092 Zurich, Switzerland. RI Butler, Paul/D-7368-2011; Schurtenberger, Peter/K-1777-2013 OI Schurtenberger, Peter/0000-0002-2790-8831 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 268-COLL BP U661 EP U661 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901953 ER PT J AU Carter, WC AF Carter, WC TI Computing macroscopic properties from microstructures of materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 044-CINF BP U533 EP U533 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901541 ER PT J AU Cole, KD AF Cole, KD TI A reversible electrophoresis gel for preparative DNA separations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 179-BIOT BP U300 EP U301 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234900829 ER PT J AU Coursey, BM AF Coursey, BM TI Marie Curie and the US National standards for radium-226 SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Phys Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 049-NUCL BP U332 EP U332 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235001079 ER PT J AU Dapkunas, S AF Dapkunas, S TI Databases for advanced ceramics design and use. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 045-CINF BP U534 EP U534 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901542 ER PT J AU Davidson, YY Soper, SA Dalluge, JJ Sander, LC AF Davidson, YY Soper, SA Dalluge, JJ Sander, LC TI Immobilization of enzymes on solid supports for micro-digestion of RNA SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 077-PRES BP U230 EP U230 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100705 ER PT J AU Epstein, MS AF Epstein, MS TI Mainstreaming quantitative analysis: A view from both sides of the fence. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 011-CHED BP U378 EP U378 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901055 ER PT J AU Ermi, BD Zhang, YB Amis, EJ AF Ermi, BD Zhang, YB Amis, EJ TI Counterion valence effects on intra- and interchain correlations in polyelectrolyte solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 134-PMSE BP U852 EP U852 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002563 ER PT J AU Ermi, BD Nisato, G Douglas, JF Karim, A AF Ermi, BD Nisato, G Douglas, JF Karim, A TI Polymer blend film phase separation on patterned SAM substrates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 501-POLY BP U149 EP U150 PN 3 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100498 ER PT J AU Farr, JK AF Farr, JK TI Predicting the consequences of chemical spills. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Seattle, WA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 019-CHAS BP U364 EP U364 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901027 ER PT J AU Fowler, BO Stansbury, JW AF Fowler, BO Stansbury, JW TI Facile syntheses of oligomeric organofluorosilsesquioxanes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NIDR, NIH, Bethesda, MD 20982 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 213-POLY BP U63 EP U63 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100212 ER PT J AU He, J Raghavan, D Hunston, DL Hoffman, DK AF He, J Raghavan, D Hunston, DL Hoffman, DK TI The influence of morphology and concentration on toughness in dispersions containing preformed acrylic elastomer particles in an epoxy matrix. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Howard Univ, Dept Chem, Washington, DC 20059 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. Dow Chem Co, Midland, MI 48674 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 101-PMSE BP U842 EP U842 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002530 ER PT J AU Heller, SR AF Heller, SR TI Databases - The journals for the new millennium. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 034-CINF BP U531 EP U531 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901531 ER PT J AU Holden, MJ Mayhew, M Vilker, VL AF Holden, MJ Mayhew, M Vilker, VL TI Putidaredoxin (PDX) interactions with redox partners in camphor P450 5-monooxygenase (CYP 101). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 049-BIOL BP U220 EP U220 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234900609 ER PT J AU Ivkov, R Bauer, BJ Amis, EJ AF Ivkov, R Bauer, BJ Amis, EJ TI Characterization of charged PAMAM dendrimer interactions in solution by small angle neutron scattering. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 177-PMSE BP U866 EP U866 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002606 ER PT J AU Karen, VL AF Karen, VL TI Crystallographic data for non-organic materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 042-CINF BP U533 EP U533 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901539 ER PT J AU Karim, A Barnes, KA Hobbie, EK Nakatani, AI AF Karim, A Barnes, KA Hobbie, EK Nakatani, AI TI Phase separation of polymer blends with fillers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 218-PHYS BP U723 EP U723 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002160 ER PT J AU Kasianowicz, JJ Akeson, M Henrickson, SE Bezrukov, SM Brandin, E Branton, D Deamer, DW AF Kasianowicz, JJ Akeson, M Henrickson, SE Bezrukov, SM Brandin, E Branton, D Deamer, DW TI Charged and neutral polymer transport in a single ionic channel. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Harvard Univ, Cambridge, MA 02138 USA. NIH, Bethesda, MD USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 263-PHYS BP U737 EP U737 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002203 ER PT J AU Kellogg, CB Irikura, KK AF Kellogg, CB Irikura, KK TI Gas phase thermochemistry of FeOx(OH)y(x+y=1,2): Portrait of a super-efficient flame suppressant.. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 188-COMP BP U751 EP U751 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234902213 ER PT J AU Khatri, CA Antonucci, JM Schumacher, GE AF Khatri, CA Antonucci, JM Schumacher, GE TI Self-etching, polymerization initiating primers for dental adhesion. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Dent & Med Mat Grp, Div Polymers, Gaithersburg, MD 20899 USA. NIST, ADAHF, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 406-POLY BP U121 EP U121 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100403 ER PT J AU Kline, SR AF Kline, SR TI Polymerization of rod-like micelles. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 238-COLL BP U652 EP U653 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901923 ER PT J AU Klouda, GA AF Klouda, GA TI Radiocarbon composition of atmospheric carbonaceous aerosol for source characterization. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Atmosphar Chem Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 083-ENVR BP U784 EP U784 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234902303 ER PT J AU Magid, LJ Butler, PD AF Magid, LJ Butler, PD TI The influence of counterions on persistence lengths of wormlike micelles. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NIST, Gaithersburg, MD 20899 USA. RI Butler, Paul/D-7368-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 237-COLL BP U652 EP U652 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901922 ER PT J AU Mallard, WG Linstron, PJ AF Mallard, WG Linstron, PJ TI The NIST WebBook - A simple tool for chemical data access. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 017-CINF BP U526 EP U526 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901515 ER PT J AU Nakatani, AI Chen, W Schmidt, RG Gordon, GV Han, CC AF Nakatani, AI Chen, W Schmidt, RG Gordon, GV Han, CC TI Chain dimensions in polysilicate-filled poly(dimethylsiloxane) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Dow Corning Corp, Midland, MI 48686 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 118-PMSE BP U848 EP U848 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002547 ER PT J AU Phinney, KW Sander, LC Wise, SA AF Phinney, KW Sander, LC Wise, SA TI Ionic polysaccharides as chiral selectors in capillary electrophoresis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 225-ANYL BP U204 EP U204 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234900565 ER PT J AU Plant, AL Meuse, CW Vanderah, D Glazier, S Silin, V Woodward, J Kasianowicz, J Krueger, S AF Plant, AL Meuse, CW Vanderah, D Glazier, S Silin, V Woodward, J Kasianowicz, J Krueger, S TI Chemistries for optimizing supported biomimetic matrices for membrane proteins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 051-BTEC BP U259 EP U259 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100788 ER PT J AU Prosa, TJ Bauer, BJ Topp, A Amis, EJ Scherrenberg, R AF Prosa, TJ Bauer, BJ Topp, A Amis, EJ Scherrenberg, R TI Size changes and interpenetration within concentrated dendrimer solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. DSM Res BV, NL-6160 MD Geleen, Netherlands. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 136-PMSE BP U853 EP U853 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002565 ER PT J AU Ramzi, A Bauer, BJ Scherrenberg, R Joosten, J Amis, EJ AF Ramzi, A Bauer, BJ Scherrenberg, R Joosten, J Amis, EJ TI SANS study of fatty acid modified dendrimers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 DSM Res, NL-6160 MD Geleen, Netherlands. NIST, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 293-PMSE BP U905 EP U905 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002719 ER PT J AU Reipa, V Gaigalas, AK AF Reipa, V Gaigalas, AK TI Charge transfer to solvent states of halide ions adsorbed on a gold electrode. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 148-COLL BP U626 EP U626 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901833 ER PT J AU Roberson, SV Gillen, G AF Roberson, SV Gillen, G TI New directions in the enhancement of ion yields in secondary ion mass spectrometry (SIMS) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Georgetown Univ, Dept Chem, Washington, DC 20057 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 063-PRES BP U226 EP U226 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100691 ER PT J AU Rosov, N Rathgeber, S Monkenbusch, M AF Rosov, N Rathgeber, S Monkenbusch, M TI Neutron spin echo spectroscopy at the NIST Center for Neutron Research SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Forschungszentrum Julich, D-52425 Julich, Germany. Univ Maryland, College Pk, MD 20742 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 172-PMSE BP U865 EP U865 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002601 ER PT J AU Rumble, J AF Rumble, J TI An integrated database approach to materials design. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Standard Ref Data Program, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 041-CINF BP U532 EP U533 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234901538 ER PT J AU Shull, RD Balogh, L Swanson, DR Tomalia, DA AF Shull, RD Balogh, L Swanson, DR Tomalia, DA TI Magnetic dendrimers and other nanocomposites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Michigan Mol Inst, Midland, MI 48650 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RI Shull, Robert/F-5971-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 069-MACR BP U319 EP U319 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100975 ER PT J AU Snyder, CR Mopsik, FI AF Snyder, CR Mopsik, FI TI A precision capacitance cell for measurement of thin film out-of-plane expansion. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Snyder, Chad/B-4957-2008 OI Snyder, Chad/0000-0002-2916-9809 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 060-PHYS BP U642 EP U642 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235002005 ER PT J AU Stansbury, JW Choi, KM AF Stansbury, JW Choi, KM TI Homopolymerization studies of new fluorinated dimethacrylate monomers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 477-POLY BP U142 EP U142 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100474 ER PT J AU Tellez, CM Cole, KD AF Tellez, CM Cole, KD TI Preparative electrochromatography of proteins in various types of porous media. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 169-BIOT BP U298 EP U298 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234900819 ER PT J AU Tewari, YB Kishore, N Goldberg, R AF Tewari, YB Kishore, N Goldberg, R TI Thermodynamics of some reactions in the chorismate pathway SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 087-BTEC BP U269 EP U269 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100824 ER PT J AU Tsai, A Bryan, P Orban, J AF Tsai, A Bryan, P Orban, J TI The folding kinetics and stability of protein G B1: A hydrogen exchange study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 105-BTEC BP U274 EP U274 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100842 ER PT J AU Wang, FW AF Wang, FW TI Application of fluorescent molecules as in situ probes of bone cement cure. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Dent & Med Mat Grp, Gaithersburg, MD 20899 USA. Hood Coll, Dept Chem & Phys, Frederick, MD 20701 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 416-POLY BP U124 EP U124 PN 3 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WZ UT WOS:000075235100413 ER PT J AU Watson, TB Keislar, RE Crescenti, GH AF Watson, TB Keislar, RE Crescenti, GH TI The use of a sulfur hexafluoride line source to measure along wind dispersion. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Air Resources Lab, Field Res Div, Idaho Falls, ID 83402 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 080-ENVR BP U783 EP U783 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WX UT WOS:000075234902300 ER PT J AU White, CC Wu, WL AF White, CC Wu, WL TI A novel method to determine the mechanical properties of ultra-thin films. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 005-PHYS BP U624 EP U624 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235001950 ER PT J AU Zimmerman, BE Cessna, JT AF Zimmerman, BE Cessna, JT TI Standardization of the positron-emitter Cu-62. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 23 PY 1998 VL 216 MA 056-NUCL BP U334 EP U334 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 107WY UT WOS:000075235001085 ER PT J AU Mildner, DFR Chen-Mayer, HH Lamaze, GP Sharov, VA AF Mildner, DFR Chen-Mayer, HH Lamaze, GP Sharov, VA TI Characterization of a cold neutron beam from a curved guide SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SYSTEMS AB A supermirror guide that includes both straight sections and curved channels has been installed at a cold neutron source facility. A description of the beam line and the beam characteristics are given. The transmitted neutron wavelength spectrum and the beam current density have been measured. Factors that affect the spectrum are discussed. Though the final straight guide section improves the spatial uniformity of the beam intensity at the guide exit, the spatial-angular correlations caused by the curved channels persist. These correlations are observed in the beam divergence measurements at various positions along the beam line using neutron imaging plate technology, and are explained by ray projections. The divergence of the transmitted beam is determined both by the critical angle of the guide and the collimation beyond the guide. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Xray Opt Syst Inc, Albany, NY 12205 USA. RP Mildner, DFR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 14 TC 13 Z9 16 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 AUG 21 PY 1998 VL 413 IS 2-3 BP 341 EP 351 DI 10.1016/S0168-9002(98)00580-4 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 118JT UT WOS:000075835300018 ER PT J AU Young, M AF Young, M TI Mode-field diameter of single-mode optical fiber by far-field scanning SO APPLIED OPTICS LA English DT Article ID SPOT SIZE; PROFILES AB I use the direct far-field method to measure the mode-field diameter of a single-mode fiber with an expanded uncertainty of 30 nm, with a coverage factor of 2. For a step-index fiber with a mode-field diameter of approximately 9 mu m, the major sources of uncertainty are nonlinearity in the electronics, angular errors and scattered light in the apparatus, and the polarization and noncircularity of the mode of the fiber. The paper concludes by showing an inconsistency in the derivation of the far-field expression for mode-field diameter. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Young, M (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. NR 24 TC 14 Z9 16 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 20 PY 1998 VL 37 IS 24 BP 5605 EP 5619 DI 10.1364/AO.37.005605 PG 15 WC Optics SC Optics GA 110CA UT WOS:000075360700012 PM 18286046 ER PT J AU Van Engen, AG Diddams, SA Clement, TS AF Van Engen, AG Diddams, SA Clement, TS TI Dispersion measurements of water with white-light interferometry SO APPLIED OPTICS LA English DT Article ID REFRACTIVE-INDEX; GROUP-DELAY; WAVELENGTH; TEMPERATURE; AMPLIFIER; DENSITY AB We measure the second- and third-order dispersion coefficients, d(2)k/dw(2) and d(3)k/d omega(3), of water for wavelengths from 0.45 to 1.3 mu m using a Michelson white-light interferometer. In this interval, the second-order dispersion ranges from 0.068 to -0.1 fs(2)/mu m, and the third-order dispersion ranges from 0.048 to 1.18 fs(3)/mu m. We observe an oscillation in d(2)k/d omega(2) near 1.1 mu m that is due to water absorption features near that wavelength. From the dispersion coefficients, derivatives of the index of refraction of water are calculated and compared with available equations. These measured values of d(2)n/d lambda(2) and d(3)n/d lambda(3) should be useful in the evaluation and improvement of existing equations for n(lambda) in water. (C) 1998 Optical Society of America. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Van Engen, AG (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Campus Box 440, Boulder, CO 80309 USA. RI Clement, Tracy/A-8885-2008; Diddams, Scott/L-2819-2013 NR 28 TC 71 Z9 71 U1 1 U2 11 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 20 PY 1998 VL 37 IS 24 BP 5679 EP 5686 DI 10.1364/AO.37.005679 PG 8 WC Optics SC Optics GA 110CA UT WOS:000075360700020 PM 18286054 ER PT J AU de Kool, M Li, HW McCray, R AF de Kool, M Li, HW McCray, R TI Thermal evolution of the envelope of SN 1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; stars : abundances; supernovae : individual (SN 1987A) ID SUPERNOVA 1987A; INFRARED-SPECTRA; LINE FORMATION; FE-II; SN-1987A; EMISSION; SPECTROSCOPY; GRAINS; GAS; SPECTROPHOTOMETRY AB We model the heating and cooling processes in the hydrogen- and helium-rich zones of the envelope of SN 1987A from t = 200 to 1200 days after outburst and use these results to calculate the light curves of the most prominent emission lines. For the first 600 days, heating and cooling processes are in equilibrium. The main heating mechanism is direct heat deposition by nonthermal electrons, and the main cooling mechanism is collisional excitation of trace elements such as Ca II, Fe II, and C I, followed by the emission of a line photon. After 600 days adiabatic cooling becomes important, and the cooling and heating rates are no longer in equilibrium Dust, formed in the Fe/Co/Ni zone after t similar to 400 days, plays an important role in the formation of the emission lines. It both modifies the internal UV radiation held that excites the ions and reduces the escaping line fluxes by extinction. The pseudocontinuum opacity in the envelope due to the many absorption lines of metals, which we model crudely by a simple power law, is also important for the emerging spectrum. Our results for the temperature evolution do not depend strongly on our assumptions. We find that the temperatures of the hydrogen and helium zones evolve from T approximate to 6000 K at t = 200 days to T approximate to 1000 K at t = 1200 days. The ionized fraction of hydrogen evolves from x(H) approximate to 6 x 10(-3) at t = 200 days to x(H) approximate to 3 x 10(-4) at t = 1200 days. With abundances determined from observations of the circumstellar ring, the model can account for the light curves of most strong emission lines of H I, He I, Ca II, and Fe II, but some discrepancies remain. Especially interesting is the H beta light curve, which exhibits a clear plateau when H beta is still optically thick, but Pa alpha is already optically thin. In all our models this phase appears to occur later than in the observations. For t greater than or similar to 800 days, the infrared emission lines of Fe II are produced mainly by primordial iron in the H/He envelope, not by newly synthesized iron. The fluxes of C I and O I lines that our model predicts are much higher than observed, and they may require a significant adjustment in abundance or mass of the different composition zones to make them agree with observations. Our models also indicate that the total helium mass in the core of the remnant (upsilon < 2500 km s(-1)) must lie in the range 2-5 M.. The hydrogen mass in the core is less well constrained, because the hydrogen line strength does not vary much as long as most of the nonthermal energy is deposited in hydrogen. The ratio of the fluxes of the Br gamma and the He I 2.058 mu m lines is slightly more sensitive, and it indicates a helium mass-to-hydrogen mass ratio similar to 1:2. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP de Kool, M (reprint author), ANUATC, John Dedman Bldg, Canberra, ACT 0200, Australia. NR 65 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 1998 VL 503 IS 2 BP 857 EP 876 DI 10.1086/306016 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152KN UT WOS:000077776700033 ER PT J AU Novelli, PC Masarie, KA Lang, PM AF Novelli, PC Masarie, KA Lang, PM TI Distributions and recent changes of carbon monoxide in the lower troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC METHANE; SOUTHERN-HEMISPHERE; INTERANNUAL VARIABILITY; EARTHS ATMOSPHERE; TRANSPORT MODEL; REFERENCE SCALE; CAPE POINT; CO; OZONE; CH4 AB Since 1988, the distribution of carbon monoixde (CO) in the lower troposphere has been determined using a globally distributed air sampling network. Site locations range from 82 degrees N to 90 degrees S, with wide longitudinal coverage, and represent the marine boundary layer, regionally polluted atmospheres, and the free troposphere. These measurements present a unique, intercalibrated, and internally consistent data set that are used to better define the global temporal and spatial distribution of CO. In this paper, times series from 49 sites are discussed. With an average lifetime of similar to 2 months, CO showed significant concentration gradients. In the lowest in the southern summer (35-45 ppb). The interhemispheric gradients showed strong seasonality with a minimum difference between the high latitudes of the northern and southern hemisphere (160-180 ppb) in February and March and a minimum in Jury and August (10-20 ppb). higher CO was found in regions near human development relative to those over more remote areas. The distributions provide additional evidence of the widespread pollution of the lower atmosphere. Remote areas in the high northern hemisphere are polluted by anthropogenic activities in the middle latitudes, and those in the southern hemisphere are heavily influence by the burning of biomass in the tropics. While tropospheric concentrations of CO exhibit periods of increase and decrease, the globally averaged CO mixing ratio over the period from 1990 through 1995 decreased at a rate of approximately 2 ppb yr(-1). C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Novelli, PC (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. EM pnovelli@cmdl.noaa.gov NR 61 TC 258 Z9 273 U1 5 U2 34 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 AUG 20 PY 1998 VL 103 IS D15 BP 19015 EP 19033 DI 10.1029/98JD01366 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 112LE UT WOS:000075495500010 ER PT J AU Joiner, J Lee, HT Strow, LL Bhartia, PK Hannon, S Miller, AJ Rokke, L AF Joiner, J Lee, HT Strow, LL Bhartia, PK Hannon, S Miller, AJ Rokke, L TI Radiative transfer in the 9.6 mu m HIRS ozone channel using collocated SBUV-determined ozone abundances SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPERATIONAL VERTICAL SOUNDER; TIROS-N; ATMOSPHERIC TRANSMITTANCE; ABSORBING GAS; TEMPERATURE; RETRIEVAL; SATELLITE; INVERSION; TRENDS; MODEL AB We have carried out a detailed analysis of radiative transfer and observational errors for the high-resolution infrared radiation sounder 2 (HIRS2) channel 9 centered in the 9.6 mu m ozone absorption band. Several previous studies have shown significant differences between the total column ozone derived from HIRS2 and the ultraviolet (UV) radiometers. Here we use collocated ozone profiles derived from the solar backscatter ultraviolet (SBUV) spectrometer to isolate errors in HIRS2 channel 9. Radiative transfer in the 9.6 mu m band is complicated because it is affected by atmospheric ozone, temperature, humidity, and the surface skin temperature and emissivity. We examine the accuracy of three fast radiative transfer algorithms. We validate current models for weak water vapor continuum absorption at 9.6 mu m. In addition, we develop a method to correct for errors in older continuum models, in ozone transmittances, and in the channel 9 spectral response function. We also identify errors resulting from the spectral dependence of the surface emissivity and propose a correction method. Using UV-derived reflectivity, we have detected instances where IR cloud-detection and cloud-clearing algorithms have apparently failed. Our results show that if appropriate corrections and quality control are applied, it is possible to compute HIRS2 channel 9 brightness temperatures with an root-mean-square (RMS) accuracy of better than similar to 0.6 K and a bias less than 0.1 K in clear skies and RMS of Getter than similar to 0.9 K and a bias less than 0.1 K in partially cloudy skies. We plan to use the methods described here to improve IR ozone retrieval algorithms. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Res & Data Syst Corp, Greenbelt, MD USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 USA. Joint Ctr Earth Syst Technol, Baltimore, MD USA. RP Joiner, J (reprint author), NASA, Goddard Space Flight Ctr, Code 910-3, Greenbelt, MD 20771 USA. EM joiner@dao.gsfc.nasa.gov; wd53hl@sun13.wwb.noaa.gov; strow@umbc.edu; bhartia@chapman.gsfc.nasa.gov; hannon@umbc.edu; miller@upair.wwb.noaa.gov; rokke@dao.gsfc.nasa.gov RI Joiner, Joanna/D-6264-2012; Rokke, Laurie/I-5642-2015; Bhartia, Pawan/A-4209-2016 OI Rokke, Laurie/0000-0002-5696-7240; Bhartia, Pawan/0000-0001-8307-9137 NR 62 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1998 VL 103 IS D15 BP 19213 EP 19229 DI 10.1029/98JD01382 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 112LE UT WOS:000075495500023 ER PT J AU Novelli, PC Connors, VS Reichle, HG Anderson, BE Brenninkmeijer, CAM Brunke, EG Doddridge, BG Kirchhoff, VWJH Lam, KS Masarie, KA Matsuo, T Parrish, DD Scheel, HE Steele, LP AF Novelli, PC Connors, VS Reichle, HG Anderson, BE Brenninkmeijer, CAM Brunke, EG Doddridge, BG Kirchhoff, VWJH Lam, KS Masarie, KA Matsuo, T Parrish, DD Scheel, HE Steele, LP TI An internally consistent set of globally distributed atmospheric carbon monoxide mixing ratios developed using results from an intercomparison of measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID REFERENCE SCALE; CO AB The Measurement of Air Pollution from Satellite (MAPS) instrument measures carbon monoxide (CO) in the middle troposphere from a space platform. In anticipation of the deployment of MAPS aboard the space shuttle. Endeavor for two 10-day missions in 1994, plans were made to prepare a set of correlative measurements which would be used as part of the mission validation program. Eleven laboratories participated in the correlative measurement program by providing NASA with the results of their CO field programs during April and October 1994. Measurements of CO in the boundary layer, while not used in the MAPS validation, provide a picture of CO in the lower troposphere. Because measurements of CO made by different laboratories have been known to differ significantly, all correlative team members participated in an intercomparison of their measurements to define potential differences in techniques and calibration scales. While good agreement was found between some laboratories, there were differences between others. The use of similar analytical techniques and calibration scales did not always provide similar results. The results of the intercomparisons were used to normalize all ground-based measurements to the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory CO reference scale. These data provide an internally consistent picture of CO in the lower atmosphere during spring and fall 1994. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Inst Water & Atmospher Res, Inst Geol & Nucl Sci, Lower Hutt, New Zealand. CSIR, EMATEK, AIM, Stellenbosch, South Africa. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Inst Nacl Pesquisas Espaciais, Sao Paulo, Brazil. Hong Kong Polytech Inst, Dept Civil & Struct Engn, Hong Kong, Peoples R China. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Japan Meteorol Agcy, Tokyo, Japan. NOAA, Aeron Lab, Boulder, CO 80303 USA. Fraunhofer Inst Atmosphar Umweltforsch, D-8100 Garmisch Partenkirchen, Germany. CSIRO, Div Atmospher Res, Aspendale, Vic 3195, Australia. RP Novelli, PC (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway,MS R-E-CG1, Boulder, CO 80303 USA. EM pnovelli@cmdl.noaa.gov RI Steele, Paul/B-3185-2009; Parrish, David/E-8957-2010; Brenninkmeijer, Carl/B-6860-2013; Garmisch-Pa, Ifu/H-9902-2014 OI Steele, Paul/0000-0002-8234-3730; Parrish, David/0000-0001-6312-2724; NR 26 TC 52 Z9 53 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1998 VL 103 IS D15 BP 19285 EP 19293 DI 10.1029/97JD00031 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 112LE UT WOS:000075495500032 ER PT J AU Doddridge, BG Morales-Morales, R Rhoads, KP Merrill, JT Novelli, PC Dickerson, RR Connors, VS Reichle, HG AF Doddridge, BG Morales-Morales, R Rhoads, KP Merrill, JT Novelli, PC Dickerson, RR Connors, VS Reichle, HG TI Ground-based and airborne observations of carbon monoxide during NASA measurements of air pollution from satellite (MAPS) missions SRL-1 and SRL-2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MACE-HEAD; INTERANNUAL VARIABILITY; ATMOSPHERIC CHEMISTRY; SCALE TRANSPORT; ATLANTIC-OCEAN; NORTH-ATLANTIC; TROPOSPHERE; OZONE; MASS; IRELAND AB Surface carbon monoxide (CO) data were acquired continuously at Heimaey, Iceland (63 degrees 24'N, 20 degrees 18'W), Mace Head, Ireland (53 degrees 19'N, 9 degrees 54'W), and Ragged Point, Barbados (13 degrees 15'N, 59 degrees 30'W), during April and October 1994, in support of Measurement of Air Pollution From Satellite (MAPS) Space Radar Laboratory (SRL) missions SRL-1 and SRL-2, respectively, measuring middle tropospheric CO from space. Observed median CO levels from the three surface sites during these two MAPS missions approximate the monthly median for 1994 and are mostly typical of data from prior years. For two of the sites, computed mission isentropic back-trajectory ensemble probability fields are compared to seasonal (March-May and September-November) probability fields for 1994 and 1986-1995. Such comparisons help gauge the representativeness of (1) observed surface air quality at, and (2) isentropic flow to, these sites during the mission periods, in terms of intraseasonal and interannual variability. Results appear consistent with longer-term flow climatological data and confirm the SRL-1 and SRL-2 mission periods are generally representative of the climatology applicable to these sites for the time of year. Lower free troposphere in situ CO data were acquired from an aircraft over the Maryland Eastern Shore, on April 14 and October 3, 4, and 6. During the April flight a nearly linear gradient in CO with pressure from 1000-650 mbar of 225-150 parts per billion by volume (ppbv) was observed. At 650 mbar, CO was quite steady around 150 ppbv; this value compares favorably with the MAPS CO data for the closest 5 degrees x 5 degrees grid box averaged April 13-15 of 105-120 ppbv. During SRL-2 a three flight CO average of 125 ppbv observed at similar to 725 mbar is in good agreement with the closest MAPS 5 degrees x 5 degrees grid box averaged October 3-7 of 90-105 ppbv. A layer of elevated CO at 845-740 mbar, most likely the result of synoptic-scale transport, was observed during the October flights and seen to dissipate with time. The MAPS cloud-filtered second-by-second CO data during concurrent shuttle overflights show temporal structure consistent with the in situ observations, indicating the MAPS weighting function may be capable of discerning features at lower altitudes than thought previously. C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23665 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Doddridge, BG (reprint author), Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. EM burce@atmos.umd.edu; raym@atmos.umd.edu; rhoads@atmos.umd.edu; jmerrill@boreas.gso.uri.edu; pnovelli@cmdl.noaa.edu; russ@atmos.umd.edu; vconnors@unity.ncsu.edu; henry_reichle@ncsu.edu RI Dickerson, Russell/F-2857-2010 OI Dickerson, Russell/0000-0003-0206-3083 NR 43 TC 7 Z9 7 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 AUG 20 PY 1998 VL 103 IS D15 BP 19305 EP 19316 DI 10.1029/97JD01837 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 112LE UT WOS:000075495500034 ER PT J AU Yurganov, LN Jaffe, DA Pullman, E Novelli, PC AF Yurganov, LN Jaffe, DA Pullman, E Novelli, PC TI Total column and surface densities of atmospheric carbon monoxide in Alaska, 1995 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SPECTROSCOPIC MEASUREMENTS; CO; ABUNDANCE; INCREASE; DATABASE; CH4 AB The results of correlated investigations of atmospheric carbon monoxide in Alaska during the spring-summer of 1995 using three different techniques are presented. CO total column abundance was measured in Fairbanks using IR spectroscopy with the Sun as a light source. A new computer retrieval code was developed and compared with the previously used technique. Surface mixing ratios were determined in situ by gas filter correlation and by gas chromatography with a mercuric oxide reduction detector. Surface measurements were made at two uncontaminated sites: Poker Flat Research Range in interior Alaska and the National Oceanic and Atmospheric Administration Point Barrow Observatory. In spring, the measurements revealed considerably more CO in the surface layer as compared with the tropospheric mean values determined by spectroscopy. This suggests an accumulation of anthropogenic CO in the boundary atmospheric layer over vast areas of the northern hemisphere during the winter. Beginning in mid-April, the CO concentration in the troposphere decreases, but the rate of decrease in the surface layer was 2-2.5 times greater than that for the troposphere as a whole. By June the surface mixing ratios and mean tropospheric values nearly converged, and the CO mixing ratio seemed to be almost constant with altitude. The July measurements revealed days with enhanced CO total column burden; these are most likely associated with lifted layers of air, polluted by forest fires. C1 Arctic & Antarctic Res Inst, St Petersburg 199226, Russia. Univ Alaska, Inst Geophys, Fairbanks, AK USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Yurganov, LN (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. EM leonid@atmosp.physics.utoronto.ca; djaffe@u.washington.edu; pnovelli@cmdl.noaa.gov NR 34 TC 8 Z9 9 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 AUG 20 PY 1998 VL 103 IS D15 BP 19337 EP 19345 DI 10.1029/97JD02299 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 112LE UT WOS:000075495500037 ER PT J AU Lagalante, AF Hall, RL Bruno, TJ AF Lagalante, AF Hall, RL Bruno, TJ TI Kamlet-Taft solvatochromic parameters of the sub- and supercritical fluorinated ethane solvents SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SOLVATION ENERGY RELATIONSHIPS; PI-STAR SCALE; CARBON-DIOXIDE; POLARITY; FLUIDS; BETA; REFRIGERANTS; SPECTROSCOPY; INDICATORS; EQUATION AB The Kamlet-Taft parameters describing the dipolarity-polarizability, pi*, and hydrogen bond acceptor ability, beta, for ethane and six fluorinated ethane solvents in the sub-and supercritical region of the phase diagram were measured using solvatochromic probe molecules. The measured ultraviolet electronic transitions of the solvatochromic probes in a given solvent were fitted to third-order polynomials in solvent density for all isotherms investigated. The values of pi* and beta were calculated for each of the solvents as a function of the solvent density. Trends in pi* values were related to the degree of fluorination about the ethane molecule, while the average beta values for all solvents were negative and were interpreted as an inability on the solvents part to act as hydrogen bond accepters. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 25 TC 26 Z9 27 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 20 PY 1998 VL 102 IS 34 BP 6601 EP 6604 DI 10.1021/jp980685d PG 4 WC Chemistry, Physical SC Chemistry GA 117MX UT WOS:000075786400023 ER PT J AU Lugez, CL Forney, D Jacox, ME Irikura, KK Thompson, WE AF Lugez, CL Forney, D Jacox, ME Irikura, KK Thompson, WE TI Infrared spectra of molecular ions derived from the hydrogen and methyl halides trapped in solid neon SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article; Proceedings Paper CT 2nd International Conference on Low Temperature Chemistry CY AUG 04-09, 1996 CL UNIV MISSOURI KANSAS CITY, KANSAS CITY, MISSOURI HO UNIV MISSOURI KANSAS CITY DE CH3X+; HX+; H2CXH+; (HX)(2); (HX)(2)(+) ID TRANSITION-STATE REGION; VIBRATIONAL-SPECTRA; MATRIX-ISOLATION; ARGON MATRICES; NEGATIVE-IONS; GAS-PHASE; ELECTRON-ATTACHMENT; ATOMS; SPECTROSCOPY; HCL AB A number of molecular ions have been stabilized in solid neon in sufficient concentration for detection of their infrared spectra. The neon matrices were prepared by codepositing the ion precursor, diluted in an excess of neon, at approximately 5 K with a beam of excited neon atoms. The results of these experiments are surveyed, and the studies of the hydrogen halides (X = Cl, Br, I) and methyl halides (X = F, Cl, Br) are described in greater detail. The position of the upsilon(2)(+) absorption of uncharged (MZ)(2) is exceptionally sensitive to the matrix material. Rotation of simple hydrides, including H2O, HX, and CH3, in solid neon is inhibited by the electric field associated with the presence of ions. The fundamental absorptions of HX+ in the neon matrix lie near the gas-phase band centers. Absorptions of (HX)(2)(+) are also identified, and the XHX- anion contributes to the infrared spectrum. In studies of the methyl halides, infrared absorptions of both the conventional (CH3X+) and the ylidion (H2CXH+) isomers are identified and assigned with the aid of ab initio calculations. The conventional structure is significantly distorted from threefold symmetry by Jahn-Teller interaction. (C) 1998 Elsevier Science B.V. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NIST, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Jacox, ME (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 62 TC 2 Z9 2 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD AUG 18 PY 1998 VL 449 IS 2-3 SI SI BP 111 EP 118 DI 10.1016/S0022-2860(98)00455-4 PG 8 WC Chemistry, Physical SC Chemistry GA 122CV UT WOS:000076054200003 ER PT J AU Leo, PJ Tiesinga, E Julienne, PS Walter, DK Kadlecek, S Walker, TG AF Leo, PJ Tiesinga, E Julienne, PS Walter, DK Kadlecek, S Walker, TG TI Elastic and inelastic collisions of cold spin-polarized Cs-133 atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION; RELAXATION RATES; POTENTIALS; EXCHANGE; CS-2; GAS AB We present theoretical calculations of thermally averaged elastic cross sections and spin-relaxation rate coefficients in the temperature range 0.1 to 300 mu K for magnetically trapped, doubly polarized cesium atoms. The calculations reproduce the recent experimental results of Arndt et al. (1997) and Soding et al. (1998) for cases where the a (3)Sigma(u) ground state potential of Cs-2 possesses a large scattering length (\A(3)\ > 35 nm) and the magnitude of the second-order spin-orbit interaction is scaled to reproduce room temperature scattering data. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. RP Leo, PJ (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Leo, Paul/B-3470-2011; Julienne, Paul/E-9378-2012; Walker, Thad/N-5590-2014 OI Leo, Paul/0000-0001-8325-4134; Julienne, Paul/0000-0002-5494-1442; Walker, Thad/0000-0002-0996-3351 NR 21 TC 44 Z9 44 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 17 PY 1998 VL 81 IS 7 BP 1389 EP 1392 DI 10.1103/PhysRevLett.81.1389 PG 4 WC Physics, Multidisciplinary SC Physics GA 110UC UT WOS:000075398100010 ER PT J AU King, BE Wood, CS Myatt, CJ Turchette, QA Leibfried, D Itano, WM Monroe, C Wineland, DJ AF King, BE Wood, CS Myatt, CJ Turchette, QA Leibfried, D Itano, WM Monroe, C Wineland, DJ TI Cooling the collective motion of trapped ions to initialize a quantum register SO PHYSICAL REVIEW LETTERS LA English DT Article ID ZERO-POINT ENERGY; GENERATION; STATES; ATOM AB We report preparation in the ground state of collective modes of motion of two trapped (9)Be(+) ions. This is a crucial step towards realizing quantum logic gates which can entangle the ions' internal electronic states. We find that heating of the modes of relative ion motion is substantially suppressed relative to that of the center-of-mass modes, suggesting the importance of these modes in future experiments. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP King, BE (reprint author), Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria. EM kingb@ucsu.Colorado.EDU RI Monroe, Christopher/G-8105-2011 NR 21 TC 232 Z9 241 U1 2 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 17 PY 1998 VL 81 IS 7 BP 1525 EP 1528 DI 10.1103/PhysRevLett.81.1525 PG 4 WC Physics, Multidisciplinary SC Physics GA 110UC UT WOS:000075398100044 ER PT J AU Hunkins, K Manley, TO Manley, P Saylor, J AF Hunkins, K Manley, TO Manley, P Saylor, J TI Numerical studies of the 4-day oscillation in Lake Champlain SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MODELS; VERIFICATION; ONTARIO; WAVES; LONG AB The summer thermocline of Lake Champlain, which is found at depths of 20-30 m, oscillates with typical vertical amplitudes of 20-40 m and periods of similar to 4 days. Fluctuations at the ends of the lake are opposite in phase and accompanied in the central lake by strong shears across the thermocline. These are basin-wide baroclinic disturbances which are forced by wind. A numerical, one-dimensional, two-layer, shallow-water model incorporating nonlinear and frictional effects in a rectangular basin forced by wind was first tested with idealized wind impulses. The results do not resemble the observed thermocline motion. However, when this simple model is forced with wind data from a nearby shore site, there is reasonable agreement between the model results and observed long-period thermocline motions in Lake Champlain. Dispersion effects appear to be negligible here. This contrasts with other long, narrow lakes where dispersion effects are important and internal surges are followed by wave trains resembling the soliton solutions of the Korteweg-deVries equation. A possible explanation for the different regime in Lake Champlain may be found in its unique bathymetry with sloping bottom at the ends and numerous embayments on the sides that provide traps to collect wind-driven warm water and then release it slowly during recovery of equilibrium, preventing the formation of steep fronts and soliton wave trains. C1 Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA. Marine Res Corp, Middlebury, VT 05753 USA. Middlebury Coll, Dept Geol, Middlebury, VT 05753 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Hunkins, K (reprint author), Columbia Univ, Lamont Doherty Geol Observ, POB 1000, Palisades, NY 10964 USA. NR 22 TC 7 Z9 7 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 1998 VL 103 IS C9 BP 18425 EP 18436 DI 10.1029/98JC01450 PG 12 WC Oceanography SC Oceanography GA 110CZ UT WOS:000075363700005 ER PT J AU Mayer, DA Molinari, RL Festa, JF AF Mayer, DA Molinari, RL Festa, JF TI The mean and annual cycle of upper layer temperature fields in relation to Sverdrup dynamics within the gyres of the Atlantic Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTH BRAZIL CURRENT; WESTERN TROPICAL ATLANTIC; SEA-SURFACE TEMPERATURE; EQUATORIAL ATLANTIC; CURRENT RETROFLECTION; MODE WATER; CIRCULATION; THERMOCLINE; VARIABILITY; TOPOGRAPHY AB Using 28 years of expendable bathythermograph data (1967-1994), we describe the mean and annual cycle of the upper ocean temperature fields in the Atlantic from 30 degrees S to 50 degrees N in the context of the basin-scale wind-driven gyres (Sverdrup stream function field), which provide a framework for describing the oceanographic measurements. We examine the circulation field implied by the temperature distributions, which are used as a proxy for the field of mass. Similarities between the temperature and stream function fields increase with depth. In the lower to subthermocline depths of the tropical and equatorial gyres the zonal currents form a closed circulation. A southeastward boundary current is suggested near and below 150 m that provides closure for the tropical gyre, and the equatorial gyre axis is southward of that suggested by the stream function field. Higher in the water column, the North Equatorial Countercurrent (NECC) may be a surface manifestation of the North Equatorial Undercurrent (NEUC), where the latter can be interpreted as the southern limb of the tropical gyre. Because there are large vertical shears in the tropics, the equatorial gyre is not clearly indicated in the vertically integrated temperature field but appears below about 200 m. Here, the South Equatorial Undercurrent (SEUC) can be interpreted as the eastward flowing northern limb of the equatorial gyre and is opposite in direction to the westward flowing South Equatorial Current above. Both the NEUC and SEUC are analagous to currents in the Pacific that are governed by non-Sverdrup dynamics. Despite the shortcomings of the data, the mean annual cycle appears to be relatively stable, and we have discounted the possibility that in regions where it represents a significant percentage of the total variance, it is changing slowly over the 28 years of record. The wind-forcing fields, which undergo large meridional movements (5 degrees-6 degrees of latitude) during their annual cycle, with some exceptions, have essentially no counterpart in gyre movements between their seasonal extremes. Most of the variability associated with the annual cycle is confined to the upper 300 m. Greatest variability, where ranges exceed 6 degrees C, occurs in the northwestern Atlantic in late winter and early spring. During this time of year south of the Gulf Stream and below about 100 m, water temperatures exhibit a systematic phase lag with depth. The next largest area of variability, where ranges can also exceed 6 degrees C, resides in the tropical western basin between the equator and 10 degrees N just below 100 m. In the eastern basin, ranges decrease and shoal. Additionally, the phase fields are consistent with the intensification and relaxation of the tropical ridge-trough system where the NECC disappears in March in the west, but the NECC/NEUC complex is strongest in September. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, Miami, FL 33149 USA. RP Mayer, DA (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Festa, John/C-3179-2014 OI Festa, John/0000-0002-5944-8219 NR 48 TC 13 Z9 13 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 1998 VL 103 IS C9 BP 18545 EP 18566 DI 10.1029/98JC01760 PG 22 WC Oceanography SC Oceanography GA 110CZ UT WOS:000075363700013 ER PT J AU Mayer, DA Weisberg, RH AF Mayer, DA Weisberg, RH TI El Nino Southern Oscillation-related ocean-atmosphere coupling in the western equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-SURFACE TEMPERATURE; EMPIRICAL ORTHOGONAL FUNCTIONS; SINGULAR-VALUE DECOMPOSITION; TROPICAL PACIFIC; TOGA-COARE; ROSSBY WAVES; ENSO EVENTS; CIRCULATION; MODELS; SYSTEM AB Using 43 years of Comprehensive Ocean-Atmosphere Data: Set and related data for the period 1950-1992, an examination is made into the regional dependence of ocean-atmosphere coupling in relation to the El Nino-Southern Oscillation (ENSO). The cross correlation between sea surface temperature (SST) and sea level pressure (SLP) anomalies over the global tropics shows two patterns of significant negative correlation consistent with a local hydrostatic response of SLP to SST: (1) the eastern Pacific, where the correlation is symmetric about and largest on the equator, and (2) the western Pacific, where symmetric regions of-negative correlation are found off the equator, separated by a region of positive correlation on the equator. Anomalies within these two patterns vary out of phase with each other. While the SLP anomalies on both sides of the basin are of similar magnitude, the SST anomalies in the east are much larger than those in the west. Despite this disparity in the SST anomaly magnitudes between the eastern and western Pacific we argue that the ocean-atmosphere couplings in the western and west-central Pacific are important for ENSO. The off-equator SST anomalies in the west enhance the SLP anomalies there, and they appear to initiate easterly wind anomalies over the far western Pacific during the peak El Nino phase of ENSO. As these easterlies evolve, their effect upon the ocean tends to oppose that of the westerly wind anomalies found over the west-central Pacific. These competing effects suggest a mechanism that may contribute to coupled ocean-atmosphere system oscillations. The west-central equatorial Pacific (the region separating the eastern and western patterns), while exhibiting large momentum and heat flux exchanges, shows minimum correlation between SST and SLP. Thus neither the SST and SLP anomaly magnitudes nor the correlation between them is alone indicative of ocean-atmosphere coupling, and the regional dependence for such coupling in relation to ENSO appears to be more complicated than mechanistic interpretations of ENSO would suggest. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Div Phys Oceanog, Miami, FL 33149 USA. Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. RP Mayer, DA (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Div Phys Oceanog, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. EM weisberg@ocg6.marine.usf.edu NR 36 TC 20 Z9 22 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 1998 VL 103 IS C9 BP 18635 EP 18648 DI 10.1029/98JC01464 PG 14 WC Oceanography SC Oceanography GA 110CZ UT WOS:000075363700018 ER PT J AU Orlanski, I AF Orlanski, I TI Poleward deflection of storm tracks SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TIME-MEAN FLOW; BAROCLINIC INSTABILITY; SOUTHERN-HEMISPHERE; TRANSIENT EDDIES; CIRCULATION; VORTICITY; ORGANIZATION; PROPAGATION; SUPPRESSION; VARIABILITY AB An analysis of 11 years of European Centre for Medium-Range Weather Forecasts data focuses primarily on the vertically averaged high-frequency transients. The conclusions are discussed in the context of (a) the winter storm track, (b) monthly variability, and (c) interannual variability. (a) Winter storm track: Results show that the pattern of the forcing by the high-frequency eddies along the storm track is highly correlated with the stationary circulation, and the forcing itself is primarily responsible for the location of the trough-ridge system associated with the stationary flow. The results also clarify the role of wind component covariance terms <(u'v')over bar> and (<(v'(2))over bar> - <(u'(2))over bar>) in the column-averaged vorticity forcing. The simpler term u'v' has the well-known effect of intensifying the anticyclonic (cyclonic) tendencies on the southern (northern) side of the jet, thereby producing an increase in the barotropic component of the zonal jet. The (<(v'(2))over bar> - <(u'(2))over bar>) term displays a quadrupole pattern, which is also approximately in phase with the trough-ridge system associated with the stationary how. (b) Monthly variability: Eddy activity has been shown to possess a seasonal life cycle, increasing during the early fall and reaching a maximum around the month of November, then decaying for most of the winter months. Month-to-month variations in eddy activity over the Pacific Ocean show that energy levels increase up through November, decreasing thereafter at the same time the trough-ridge circulation pattern is intensifying. By December, baroclinicity in the western Pacific has increased substantially, and low-level eddies are found to break by the middle of the ocean. Upper-level eddies start to break well before reaching the west coast of North America, resulting in a displacement of the maximum in (<(v'(2))over bar> - <(u'(2))over bar>) westward from its November position and increasing the trough-ridge forcing by the high-frequency eddies. (c) Interannual variability: Wintertime eddy kinetic energy is seen to extend further eastward through the Pacific Ocean during the warm phase but displays. an abrupt termination during the cold phase. Anomalies in the eddy transient forcing tend to be quite similar to that of the Pacific-North American pattern itself. The extension of the storm track during the warm phase resembles that of fall conditions and is present in the winter season because the source of low-level baroclinicity is extended well into the eastern Pacific for this El Nino-Southern Oscillation phase. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Orlanski, I (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 32 TC 47 Z9 49 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 15 PY 1998 VL 55 IS 16 BP 2577 EP 2602 DI 10.1175/1520-0469(1998)055<2577:PDOST>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 109AM UT WOS:000075299100001 ER PT J AU Molinari, J Skubis, S Vollaro, D Alsheimer, F Willoughby, HE AF Molinari, J Skubis, S Vollaro, D Alsheimer, F Willoughby, HE TI Potential vorticity analysis of tropical cyclone intensification SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ANGULAR-MOMENTUM FLUXES; SEA INTERACTION THEORY; HURRICANE INTENSITY; EXTERNAL INFLUENCES; BAROCLINIC ENVIRONMENT; VERTICAL SHEAR; VORTEX; EVOLUTION; CIRCULATION; DYNAMICS AB The interaction of marginal Tropical Storm Danny (1985) with an upper-tropospheric positive potential vorticity anomaly was examined. The intensification mechanism proposed earlier for mature Hurricane Elena appears to be valid for Danny as well, despite significant differences in the synoptic-scale environment and in the stage of the tropical cyclone prior to the interaction. Both storms experienced rapid pressure falls as a relatively small-scale positive upper potential vorticity anomaly began to superpose with the low-level tropical cyclone center. The interaction is described in terms of a complex interplay between vertical wind shear, diabatic heating, and mutual advection among vortices at and below the level of the outflow anticyclone. Despite this complexity, the superposition principle appears to be conceptually useful to describe the intensification of tropical cyclones during such interactions. C1 SUNY Albany, Dept Earth & Atmospher Sci, Albany, NY 12222 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Molinari, J (reprint author), SUNY Albany, Dept Earth & Atmospher Sci, Albany, NY 12222 USA. NR 53 TC 60 Z9 65 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 15 PY 1998 VL 55 IS 16 BP 2632 EP 2644 DI 10.1175/1520-0469(1998)055<2632:PVAOTC>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 109AM UT WOS:000075299100004 ER PT J AU Stivers, JT AF Stivers, JT TI 2-aminopurine fluorescence studies of base stacking interactions at abasic sites in DNA: metal-ion and base sequence effects SO NUCLEIC ACIDS RESEARCH LA English DT Article ID CONTAINING DEOXYTRIDECANUCLEOTIDE DUPLEXES; CONFORMATIONAL TRANSITIONS; ESCHERICHIA-COLI; ENDONUCLEASE-V; NMR; OPPOSITE; OLIGODEOXYNUCLEOTIDE; HETERODUPLEX; TEMPERATURE; RECOGNITION AB Metal-ion and sequence dependent changes in the stacking interactions of bases surrounding abasic (AB) sites in 10 different DNA duplexes were examined by incorporating the fluorescent nucleotide probe 2-aminopurine (2-AP), opposite to the site (AB-AP(opp)) or adjacent to the site (AB-AP(adj)) on either strand. A detailed study of the fluorescence emission and excitation spectra of these AB duplexes and their corresponding parent duplexes indicates that AB-AP(opp) is significantly less stacked than 2-AP in the corresponding normal duplex. In general, AB-AP(adj) on the AB strand is stacked, but AB-AP(adj) on the opposite strand shows destabilized stacking interactions. The results also indicate that divalent cation binding to the AB duplexes contributes to destabilizaton of the base stacking interactions of AB-AP(opp), but has little or no effect on the stacking interactions of AB-AP(adj), Consistent with these results, the fluorescence of AB-AP(opp) is 18-30-fold more sensitive to an externally added quenching agent than the parent normal duplex. When uracil DNA glycosylase binds to AB-AP(opp) in the presence of 2.5 mM MgCl2, a 3-fold decrease in fluorescence is observed (K-d = 400 +/- 90 nM) indicating that the unstacked 2-AP(opp) becomes more stacked upon binding. On the basis of these fluorescence studies a model for the local base stacking interactions at these AB sites is proposed. C1 Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Rockville, MD 20850 USA. RP Stivers, JT (reprint author), Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. FU NIGMS NIH HHS [GM56834, R01 GM056834] NR 40 TC 167 Z9 167 U1 0 U2 23 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD AUG 15 PY 1998 VL 26 IS 16 BP 3837 EP 3844 DI 10.1093/nar/26.16.3837 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 110YB UT WOS:000075408200030 PM 9685503 ER PT J AU Paek, EG Choe, JY Oh, TK AF Paek, EG Choe, JY Oh, TK TI Transverse grating-assisted narrow-bandwidth acousto-optic tunable filter SO OPTICS LETTERS LA English DT Article ID WAVELENGTH AB An experimental acousto-optic tunable filter that has a narrow spectral bandwidth (0.2 nm at 1550 nm) and a fast (10-mu s) tuning capability with a continuous tuning range of approximately 50 nm is described. The tunable filter consists of an acousto-optic beam deflector with a diffraction grating whose grating vector is transverse to the direction of light propagation. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Paek, EG (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 11 TC 9 Z9 9 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 15 PY 1998 VL 23 IS 16 BP 1322 EP 1324 DI 10.1364/OL.23.001322 PG 3 WC Optics SC Optics GA 111GE UT WOS:000075428300026 PM 18087512 ER PT J AU Kobayashi, R Warren, JA Carter, WC AF Kobayashi, R Warren, JA Carter, WC TI Vector-valued phase field model for crystallization and grain boundary formation SO PHYSICA D LA English DT Article DE crystal/disordered interface ID KINETICS; TRANSITIONS; GROWTH AB We propose a new model for calculation of the crystalliztation and impingement of many particles with differing orientations. Based on earlier phase field models, a vector order parameter is introduced, and thus orientation of crystal/disordered interfaces can be determined relative to a crystalline frame. This model improves upon previous attempts to describe this phenomenon, as it requires far fewer equations of motion, and is energetically invariant under rotations. In this report a one-dimensional simulation of the model will be presented along with preliminary investigations of two-dimensional simulations. (C) 1998 Elsevier Science B.V. C1 Hokkaido Univ, Res Inst Elect Sci, Sapporo, Hokkaido 060, Japan. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Kobayashi, R (reprint author), Hokkaido Univ, Res Inst Elect Sci, Sapporo, Hokkaido 060, Japan. RI Carter, W/K-2406-2012 NR 9 TC 105 Z9 106 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD AUG 15 PY 1998 VL 119 IS 3-4 BP 415 EP 423 DI 10.1016/S0167-2789(98)00026-8 PG 9 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 106GV UT WOS:000075122300010 ER PT J AU Woicik, JC Cross, JO Bouldin, CE Ravel, B Pellegrino, JG Steiner, B Bompadre, SG Sorensen, LB Miyano, KE Kirkland, JP AF Woicik, JC Cross, JO Bouldin, CE Ravel, B Pellegrino, JG Steiner, B Bompadre, SG Sorensen, LB Miyano, KE Kirkland, JP TI Diffraction anomalous fine-structure study of strained Ga1-xInxAs on GaAs(001) SO PHYSICAL REVIEW B LA English DT Article ID X-RAYS; SCATTERING; ALLOYS; HETEROSTRUCTURES; LAYERS AB Diffraction anomalous fine-structure measurements performed at both the Ga and As K edges have determined the Ga-As bond length to be 2.442+/-0.005 Angstrom in a buried, 213-Angstrom-thick Ga0.785In0.215As layer grown coherently on GaAs(001). This bond length corresponds to a strain-induced contraction of 0.013+/-0.005 Angstrom relative to the Ga-As bond length in bulk Ga1-xInxAs of the same composition. Together with recent extended x-ray-absorption fine-structure measurements performed at the In K edge [Woicik et al., Phys. Rev. Lett. 79, 5026 (1997)], excellent agreement is found with the uniform bond-length distortion model for strained-layer semiconductors on (001) substrates. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. CUNY Brooklyn Coll, Dept Phys, Brooklyn, NY 11210 USA. SFA Inc, Largo, MD 20774 USA. RP Woicik, JC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 26 TC 20 Z9 20 U1 0 U2 3 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 AUG 15 PY 1998 VL 58 IS 8 BP R4215 EP R4218 DI 10.1103/PhysRevB.58.R4215 PG 4 WC Physics, Condensed Matter SC Physics GA 117GE UT WOS:000075772500006 ER PT J AU Schantz, MM Bowadt, S Benner, BA Wise, SA Hawthorne, SB AF Schantz, MM Bowadt, S Benner, BA Wise, SA Hawthorne, SB TI Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of polychlorinated biphenyls in environmental matrix standard reference materials SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE extraction methods; polychlorinated biphenyls ID CHLORINATED PESTICIDES; WHALE BLUBBER; CHLOROBIPHENYLS; CONGENERS; PCBS AB Supercritical fluid extraction (SFE) was compared to traditional Soxhlet extraction for the determination of polychlorinated biphenyl congeners in three standard reference materials: SRM 1941a (Organics in Marine Sediment), SRM 1944 (New York/New Jersey Waterway Sediment) and SRM 2974 [Organics in Mussel Tissue (Mytilus edulis) (Freeze-Dried)]. The concentrations determined using SFE compared well with the certified concentrations for the majority of the polychlorinated biphenyl congeners. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ N Dakota, Energy & Environm Res Ctr, Grand Forks, ND 58202 USA. RP Schantz, MM (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 22 TC 43 Z9 45 U1 0 U2 5 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 AUG 14 PY 1998 VL 816 IS 2 BP 213 EP 220 DI 10.1016/S0021-9673(98)00528-7 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 112NM UT WOS:000075500700012 PM 9742714 ER PT J AU Xiao, GY Parsons, JF Tesh, K Armstrong, RN Gilliland, GL AF Xiao, GY Parsons, JF Tesh, K Armstrong, RN Gilliland, GL TI Conformational changes in the crystal structure of rat glutathione transferase M1-1 with global substitution of 3-fluorotyrosine for tyrosine SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE glutathione transferase; 3-fluorotyrosine; protein; crystallography; three-dimensional structure; detoxification enzyme ID COLI DIHYDROFOLATE-REDUCTASE; NUCLEAR MAGNETIC-RESONANCE; S-TRANSFERASE; CATALYTIC MECHANISM; 3-DIMENSIONAL STRUCTURE; ESCHERICHIA-COLI; LIGAND-BINDING; NMR-SPECTROSCOPY; PROTEIN; RESOLUTION AB The structure of the tetradeca-(3-fluorotyrosyl) M1-1 GSH transferase (3-FTyr GSH transferase), a protein in which tyrosine residues are globally substituted by 3-fluorotyrosines has been determined at 2.2 Angstrom resolution. This variant was produced to study the effect on the enzymatic mechanism and the structure was undertaken to assess how the presence of the 3-fluorotyrosyl residue influences the protein conformation and hence its function. Although fluorinated amino acid residues have frequently been used in biochemical and NMR investigations of proteins, no structure of a protein that has been globally substituted with a fluorinated amino acid has previously been reported. Thus, this structure represents the first crystal structure of such a protein containing a Library of 14 (28 crystallographically distinct) microenvironments from which the nature of the interactions of fluorine atoms with the rest of the protein can be evaluated. Numerous conformational changes are observed in the protein structure as a result of substitution of 3-fluorotyrosine for tyrosine. The results of the comparison of the crystal structure of the fluorinated protein with the native enzyme reveal that conformational changes are observed for most of the 3-fluorotyrosines. The largest differences are seen for residues where the fluorine, the OH, or both are directly involved in interactions with other regions of the protein or with a symmetry-related molecule. The fluorine atoms of the 3-fluorotyrosine interact primarily through hydrogen bonds with other residues and water molecules. In several cases, the conformation of a 3-fluorotyrosine is different in one of the monomers of the enzyme from that observed in the other, including different hydrogen-bonding patterns. Altered conformations can be related to differences in the crystal packing interactions of the two monomers in the asymmetric unit. The fluorine atom on the active-site Tyr6 is located near the S atom of the thioether product (9R,10R)-9-(S-glutathionyl)-10-hydroxy-9,10-dihydrophenanthrene and creates a different pattern of interactions between 3-fluorotyrosine 6 and the S atom. Studies of these interactions help explain why 3-FTyr GSH transferase exhibits spectral and kinetic properties distinct from the native GSH transferase. (C) 1998 Academic Press. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Rockville, MD 20850 USA. Vanderbilt Univ, Dept Biochem, Sch Med, Nashville, TN 37232 USA. Vanderbilt Univ, Ctr Mol Toxicol, Sch Med, Nashville, TN 37232 USA. RP Gilliland, GL (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. EM gary.gilliland@nist.gov FU NIEHS NIH HHS [P30-ES00267]; NIGMS NIH HHS [R01-GM30910] NR 39 TC 38 Z9 38 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD AUG 14 PY 1998 VL 281 IS 2 BP 323 EP 339 DI 10.1006/jmbi.1998.1935 PG 17 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 108NN UT WOS:000075272500012 PM 9698551 ER PT J AU Serpa, FG Gillaspy, JD Trabert, E AF Serpa, FG Gillaspy, JD Trabert, E TI Lifetime measurements in the ground configuration of Ar13+ and Kr22+ using an electron beam ion trap SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID MAGNETIC-DIPOLE TRANSITION; HIGHLY-CHARGED IONS; ISOELECTRONIC SEQUENCE; PROBABILITIES; KR AB We have measured the radiative lifetimes for the 2s(2)2p P-2(3/2) level of Ar13+ and the 3s(2)3p(2) P-3(2) level of Kr22+. These measurements were performed by monitoring the temporal behaviour of their associated radiative decays during magnetic trapping mode in an electron beam ion trap (EBIT). Our lifetime results, 8.7(5) ms for Ar13+ and 5.7(5) ms for Kr22+, are compared with theory. C1 Univ Notre Dame, Notre Dame, IN 46556 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Serpa, FG (reprint author), Univ Notre Dame, Notre Dame, IN 46556 USA. NR 28 TC 41 Z9 41 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD AUG 14 PY 1998 VL 31 IS 15 BP 3345 EP 3352 DI 10.1088/0953-4075/31/15/008 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 113RR UT WOS:000075565500008 ER PT J AU Kato, S Bierbaum, VM Leone, SR AF Kato, S Bierbaum, VM Leone, SR TI Multiquantum vibrational deactivation of N-2(+)(upsilon) by collisions with N-2, and O-2 at thermal energies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ION-MOLECULE REACTIONS; CHARGE-TRANSFER; TEMPERATURE-DEPENDENCE; RATE CONSTANTS; RELAXATION; CO2; AR; EXCHANGE; N2; DYNAMICS AB Vibrational deactivation and charge transfer in the collisions of N-2(+)(nu = 0-4) With N-2 and O-2 are studied at thermal energies. State-specific rate constants for the individual components of charge transfer and vibrational deactivation are determined using the selected-ion flow tube, laser-induced fluorescence technique. The N-15(2)+(nu = 0) + N-14(2) reaction proceeds via symmetric charge transfer at one-half the Langevin rate constant (0.5k(L)), indicating efficient charge equilibration, whereas the total removal rates of nu = 1-4 (similar to 6 x 10(-10) cm(3) molecule(-1) s(-1)) exceed 0.5k(L). This indicates that vibrational transfer, in addition to charge equilibration, contributes to the removal of N-2(+)(nu > 0) by collisions with Nz. The N-2(+)(nu) + O-2 removal rates are significantly enhanced upon vibrational excitation; the total rate constant for nu = 4 is 3.0 x 10-(10) cm(3) molecule(-1) s(-1), six times larger than that for nu = 0. The enhancement is shown to be primarily due to increased vibrational deactivation, although a small enhancement of the charge-transfer channel also occurs for N-2(+)(nu greater than or equal to 2) + O-2. Multiquantum vibrational energy transfer during single collisions plays an important role in the deactivation of N-2(+)(nu greater than or equal to 2) with both N-2 and O-2. The occurrence of multiquantum deactivation is rationalized by the existence of significantly deep potential wells for N-2(+)-N-2 and N-2(+)-O-2, which arise from electron-exchange interactions. Small modifications are also made to the earlier studies on the reactions of N-2(+)(nu greater than or equal to 2) + N-2 (Frost, M. J.; et al. J. Chem. Phys. 1994, 100, 6359) and N-2(+)(nu greater than or equal to 2) + O-2 (Kato, S.; et al. Can. J. Chem. 1991, 72, 625). C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. NR 47 TC 11 Z9 11 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 13 PY 1998 VL 102 IS 33 BP 6659 EP 6667 DI 10.1021/jp981679k PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 112TF UT WOS:000075509700009 ER PT J AU Bandyopadhyay, S Shelley, JC Tarek, M Moore, PB Klein, ML AF Bandyopadhyay, S Shelley, JC Tarek, M Moore, PB Klein, ML TI Surfactant aggregation at a hydrophobic surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID MOLECULAR-DYNAMICS SIMULATION; SODIUM DODECYL-SULFATE; AIR-WATER-INTERFACE; NEUTRON REFLECTION; ADSORBED LAYER; PHASE-DIAGRAM; LIQUID WATER; BROMIDE; SPECTROSCOPY; MICROSCOPY AB Molecular dynamics (MD) simulations have been carried out to investigate the morphology of monolayers of the cationic surfactant cetyltrimethylammonium bromide (C(16)TAB) at the interface between a hydrophobic substrate and an aqueous solution. The simulation system consisted of two flat hydrophobic surfaces separated by a distance of 70 Angstrom along z (direction normal to the interface). Initially, one surface was covered with a uniform monolayer of 94 erect surfactant molecules, with surface area of 45 Angstrom(2)/molecule. The other surface was covered with two hemicylindrical aggregates, each containing 64 surfactant molecules. A 1 ns trajectory was then generated at constant volume and temperature (T = 300 K). The hemicylinder aggregates relaxed to a semielliptical rather than semicircular cross section but were observed to be otherwise stable during the simulation run. The monolayer arrangement was, however, unstable and evolved into hemicylindrical type aggregates. The present simulation provides support for the interpretation of recent atomic force microscopy (AFM) measurements, which claim C(16)TAB forms stable hemicylindrical aggregates at the interface between an aqueous solution and hydrophobic surfaces, such as graphite. C1 Univ Penn, Ctr Mol Modeling, Philadelphia, PA 19104 USA. Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. Procter & Gamble Co, Miami Valley Labs, Corp Res Div, Cincinnati, OH 45253 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Klein, ML (reprint author), Univ Penn, Ctr Mol Modeling, Philadelphia, PA 19104 USA. NR 44 TC 69 Z9 69 U1 0 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 13 PY 1998 VL 102 IS 33 BP 6318 EP 6322 DI 10.1021/jp982051c PG 5 WC Chemistry, Physical SC Chemistry GA 112TP UT WOS:000075510500004 ER PT J AU Gaffen, DJ AF Gaffen, DJ TI Falling satellites, rising temperatures? SO NATURE LA English DT Editorial Material C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Gaffen, DJ (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 13 PY 1998 VL 394 IS 6694 BP 615 EP 616 DI 10.1038/29163 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 110MD UT WOS:000075384200013 ER PT J AU Dove, JB Wilms, J Nowak, MA Vaughan, BA Begelman, MC AF Dove, JB Wilms, J Nowak, MA Vaughan, BA Begelman, MC TI RXTE observation of Cygnus X-1 - I. Spectral analysis SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; radiation mechanisms : non-thermal; radiative transfer; binaries : general; stars : individual : Cyg X-1; X-rays : stars ID X-RAY EXCESS; ACCRETION; ADVECTION; EMISSION AB We present the results of the analysis of the broad-band spectrum of Cygnus X-1 from 3.0 to 200 keV, using data from a 10-ks observation by the Rossi X-ray Timing Explorer (RXTE). The spectrum can be well described phenomenologically by an exponentially cut-off power law with a photon index Gamma = 1.45(-0.02)(+0.01) (a value considerably harder than is typically found), e-folding energy E-f = 162(-8)(+9) keV, plus a deviation from a power law that formally can be modelled as a thermal blackbody with temperature kT(BB) = 1.2(-0.1)(+0.0) keV, Although the 3-30 keV portion of the spectrum can be fitted with a reflected power law with Gamma = 1.81 +/- 0.01 and covering fraction f = 0.35 +/- 0.02, the quality of the fit is significantly reduced when the HEXTE data in the 30-100 keV range are included, as there is no observed softening in the power law within this energy range. As a physical description of this system, we apply the accretion disc corona models of Dove, Wilms & Begelman, in which the temperature of the corona is determined self-consistently. A spherical corona with a total optical depth tau = 1.6 +/- 0.1 and an average temperature kT(C) = 87 +/- 5 keV, surrounded by an exterior cold disc, does provide a good description of the data (chi(red)(2) = 1.55). These models deviate from the data by up to 7 per cent in the 5-10 keV range, and we discuss possible reasons for these discrepancies. However, considering how successfully the spherical corona reproduces the 10-200 keV data, such 'photon-starved' coronal geometries seem very promising for explaining the accretion processes of Cygnus X-1. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Inst Astron & Astrophys, Abt Astron, D-72076 Tubingen, Germany. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. RP Dove, JB (reprint author), Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. RI Wilms, Joern/C-8116-2013 OI Wilms, Joern/0000-0003-2065-5410 NR 30 TC 46 Z9 46 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 11 PY 1998 VL 298 IS 3 BP 729 EP 736 DI 10.1046/j.1365-8711.1998.01673.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 114GX UT WOS:000075601700013 ER PT J AU Thomas, JB Duewer, DL Kline, MC Sharpless, KE AF Thomas, JB Duewer, DL Kline, MC Sharpless, KE TI The stability of retinol, alpha-tocopherol, trans-lycopene, and trans-beta-carotene in liquid-frozen and lyophilized serum SO CLINICA CHIMICA ACTA LA English DT Article DE liquid chromatography; vitamins; carotenoids; human serum; storage duration ID VITAMIN-RELATED-COMPOUNDS; PLASMA; CHROMATOGRAPHY; STORAGE AB The concentrations of retinol, alpha-tocopherol, and trans-beta-carotene in lyophilized serum stored at - 25 degrees C and - 80 degrees C have been monitored for 10 years. There was no evidence of degradation of any of these compounds over the 10-year period. Retinol, alpha-tocopherol, and trans-beta-carotene were less stable at - 25 degrees C in liquid-frozen serum than they were in lyophilized serum. At - 80 degrees C, trans-beta-carotene levels were stable for up to 3 years of storage in liquid-frozen serum. Both retinol and alpha-tocopherol appeared stable in liquid-frozen serum for at least 5 years at - 80 degrees C. The effect of repeated freeze/thaw cycles on retinol, alpha-tocopherol, trans-lycopene, and trans-beta-carotene in liquid-frozen and reconstituted lyophilized serum both stored at - 20 degrees C was also studied. Retinol, alpha-tocopherol, trans-lycopene, and trans-beta-carotene in reconstituted lyophilized serum stored at - 20 degrees C were stable for at least 3 days with minimal ( < 5) freeze/thaw cycles. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Thomas, JB (reprint author), NIST, Div Analyt Chem, Bldg 222,Room B208, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 21 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-8981 J9 CLIN CHIM ACTA JI Clin. Chim. Acta PD AUG 10 PY 1998 VL 276 IS 1 BP 75 EP 87 PG 13 WC Medical Laboratory Technology SC Medical Laboratory Technology GA 117WC UT WOS:000075804800007 ER PT J AU Park, C Wong-Ng, W Cook, LP Snyder, RL Sastry, PVPSS West, AR AF Park, C Wong-Ng, W Cook, LP Snyder, RL Sastry, PVPSS West, AR TI Melting investigation of Bi2Sr1.9Ca2.1Cu3O10+x by high temperature X-ray diffraction and quenching SO PHYSICA C LA English DT Article DE melting; Bi2Sr1.9Ca2.1Cu3O10+x; high temperature x-ray diffraction (HTXRD); quenching ID FREE BI2SR2CA2CU3O10 SUPERCONDUCTOR; TEXTURE FORMATION; PHASE-EQUILIBRIA; SOLID-SOLUTIONS; SYSTEM; TAPES; BI2SR2CACU2OY; STOICHIOMETRY; STABILITY; BI-2212 AB A combination of in-situ high temperature X-ray (HTXRD), quenching experiments and energy dispersive X-ray spectrometry (EDS) was used to investigate the melting sequence of the high T-c 2223 (Bi:Sr:Ca:Cu) superconductor phase. The occurrence and disappearance of various phases associated with the melting of this phase are discussed for both Ag-free and Ag-containing samples. In both Ag-free and Ag-containing samples, three insulator phases were observed during the melting process with HTXRD. In the Ag-free sample, melting started between 880 degrees C and 890 degrees C. At 890 degrees C, both (Sr,Ca)(14)Cu24O41 and (Ca,Sr)(2)CuO3 were present. The (Sr,Ca)(14)Cu24O41 phase disappeared at about 900 degrees C and (Ca,Sr)(2)CuO3 persisted until approximate to 950 degrees C, at which point (Ca,Sr)O was observed. In the Ag-containing sample, a similar melting sequence was observed except that the initial melting temperature of the 2223 phase was lowered by about 20-30 degrees C. Ag was found to enter the liquid. It appears that this liquid promotes grain growth and preferred orientation. It was found that the melting process of the 2223 phase is similar to that of the 2212 (Bi:Sr:Ca:Cu) phase in that both melt incongruently to strontium calcium cuprates. The quench experiments showed that the 119 x 5/22 x 1 phase was an additional primary phase during melting. The absence of this phase during the HTXRD experiment could be due to the fact that the 119 x 5/22 x 1 grains are denser than the liquid and therefore sink below the surface of the sample. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Univ Aberdeen, Dept Chem, Aberdeen AB9 2UE, Scotland. RP Wong-Ng, W (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Yoon, Sejin/F-7637-2013; OI West, Anthony/0000-0002-5492-2102 NR 43 TC 11 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD AUG 10 PY 1998 VL 304 IS 3-4 BP 265 EP 276 DI 10.1016/S0921-4534(98)00290-1 PG 12 WC Physics, Applied SC Physics GA 120YV UT WOS:000075986200014 ER PT J AU Xie, R Karim, A Douglas, JF Han, CC Weiss, RA AF Xie, R Karim, A Douglas, JF Han, CC Weiss, RA TI Spinodal dewetting of thin polymer films SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE-SEPARATION; BLEND AB Dewetting of polystyrene films on a silicon substrate is investigated as a function of film thickness h. We observe the nucleation of holes in the early stage of dewetting for relatively thick films (h > 100 Angstrom), as observed previously, but the breakup of thinner films occurs through the growth of uniformly distributed surface undulations ("spinodal dewetting"). The average amplitude delta h of these undulations increases exponentially up to the film rupture point where delta h becomes comparable to h, as predicted by a capillary wave instability model. C1 Univ Connecticut, Polymer Sci Program, Storrs, CT 06269 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Univ Connecticut, Polymer Sci Program, Storrs, CT 06269 USA. NR 21 TC 446 Z9 448 U1 12 U2 113 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 AUG 10 PY 1998 VL 81 IS 6 BP 1251 EP 1254 DI 10.1103/PhysRevLett.81.1251 PG 4 WC Physics, Multidisciplinary SC Physics GA 109CL UT WOS:000075303600029 ER PT J AU Banin, U Lee, CJ Guzelian, AA Kadavanich, AV Alivisatos, AP Jaskolski, W Bryant, GW Efros, AL Rosen, M AF Banin, U Lee, CJ Guzelian, AA Kadavanich, AV Alivisatos, AP Jaskolski, W Bryant, GW Efros, AL Rosen, M TI Size-dependent electronic level structure of InAs nanocrystal quantum dots: Test of multiband effective mass theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB The size dependence of the electronic spectrum of InAs nanocrystals ranging in radius from 10-35 Angstrom has been studied by size-selective spectroscopy. An eight-band effective mass theory of the quantum size levels has been developed which describes the observed absorption level structure and transition intensities very well down to smallest crystal size using bulk band parameters. This model generalizes the six-band model which works well in CdSe nanocrystals and should adequately describe most direct semiconductor nanocrystals with band edge at the Gamma-point of the Brillouin zone. (C) 1998 American Institute of Physics. C1 Inst Fizyki UMK, Torun, Poland. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Nanostruct Opt Sect, Washington, DC 20375 USA. RP Banin, U (reprint author), Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. RI Jaskolski, Wlodzimierz/D-1318-2014; Alivisatos , Paul /N-8863-2015 OI Jaskolski, Wlodzimierz/0000-0003-4814-1876; Alivisatos , Paul /0000-0001-6895-9048 NR 16 TC 133 Z9 133 U1 0 U2 26 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 1998 VL 109 IS 6 BP 2306 EP 2309 DI 10.1063/1.476797 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 107XW UT WOS:000075237100032 ER PT J AU Krueger, S Gorshkova, I Brown, J Hoskins, J McKenney, KH Schwarz, FP AF Krueger, S Gorshkova, I Brown, J Hoskins, J McKenney, KH Schwarz, FP TI Determination of the conformations of cAMP receptor protein and its T127L,S128A mutant with and without cAMP from small angle neutron scattering measurements SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID CYCLIC-NUCLEOTIDE BINDING; GENE ACTIVATOR PROTEIN; ESCHERICHIA-COLI; RESOLUTION; MECHANISM; MUTATIONS; DNA AB Small angle neutron scattering (SANS) measurements were performed on solutions of cAMP receptor protein (CRP) and on solutions of the T127L,S128A double mutant of CRP (CRPQ*) in D2O K3PO4 buffer containing 0.5 M KCI, in the absence and presence of 3',5' cyclic adenosine monophosphate (cAMP). Energy-minimized structures of the CRP were calculated by minimization of the x-ray crystallographic structure of CRP in either the exclusively "closed" form where the alpha-helices of the carboxyl-terminal domain are folded close to the amino-terminal domain and in the exclusively "open" form where the alpha-helices of the carboxyl-terminal domain are folded away from the amino-terminal domain. Neutron scattering models show that the CRP SANS data follow closely the data curve predicted for unligated CRP in the open form, whereas the cAMP-ligated data are more in agreement with the data predicted for the minimized cAMP-ligated CRP structure in the closed form, Thus, it appears that CRP undergoes a conformational change from the open form to the closed form in solution upon ligation with cAMP. The SANS data from the CRP* and cAMP-ligated CRP*: are coincidental, which implies that there is very little structural difference between the two species of CRP*. This is in agreement with in vivo results, which show that whereas CRP activates transcription in the cell only in the presence of cAMP, CRP* activates transcription in the absence of cAMP, implying that CRP* is already in the correct conformation for the activation of transcription. C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Schwarz, FP (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 23 TC 29 Z9 29 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 7 PY 1998 VL 273 IS 32 BP 20001 EP 20006 DI 10.1074/jbc.273.32.20001 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 109DF UT WOS:000075305400014 PM 9685337 ER PT J AU Block, BA Dewar, H Farwell, C Prince, ED AF Block, BA Dewar, H Farwell, C Prince, ED TI A new satellite technology for tracking the movements of Atlantic bluefin tuna SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID POPULATION-STRUCTURE; PACIFIC-OCEAN; MITOCHONDRIAL AB The movements of Atlantic bluefin tuna (Thunnus thynnus thynnus) have captured the interest of scientists and fishers since the time of Aristotle, This tuna is unique among bony fish for maintaining elevated body temperatures (21 degrees C above ambient) and attaining large size (up to 750 kg), We describe here the use of a pop-off satellite tag, for investigating the Atlantic-wide movements and potential stock overlap of western and eastern Atlantic bluefin tuna. The tag also archives data on mater temperatures. The objectives of this study were to evaluate the effectiveness of the technology, study the movements of Atlantic bluefin tuna, examine their thermal niche, and assess survivorship of tagged fish. The pop-off satellite technology provides data independent of commercial fisheries that, when deployed in sufficient quantity, should permit a critical test of the stock structure hypotheses for Atlantic bluefin tuna. C1 Stanford Univ, Hopkins Marine Stn, Pacific Grove, CA 93950 USA. Monterey Bay Aquarium, Tuna Res & Conservat Ctr, Monterey, CA 93940 USA. NOAA, US Dept Commerce, SE Fisheries Sci Ctr, Miami, FL 33149 USA. RP Block, BA (reprint author), Stanford Univ, Hopkins Marine Stn, Oceanview Blvd, Pacific Grove, CA 93950 USA. NR 28 TC 136 Z9 143 U1 4 U2 20 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 4 PY 1998 VL 95 IS 16 BP 9384 EP 9389 DI 10.1073/pnas.95.16.9384 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 108BR UT WOS:000075246600059 PM 9689089 ER PT J AU Srolovitz, DJ Sridhar, N Hirth, JP Cahn, JW AF Srolovitz, DJ Sridhar, N Hirth, JP Cahn, JW TI Shape of hollow dislocation cores: Anisotropic surface energy and elastic effects SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT Symposium on Defects in Crystals Honoring John Hirth at the TMS Annual Meeting CY FEB 16-19, 1998 CL SAN ANTONIO, TEXAS SP TMS, Electr Magnet & Photon Mat Div, TMS, Struct Mat Div, TMS, Chem & Phy Mat Comm, TMS, Phys Met Comm, TMS, Shaping & Forming Comm, Pacific NW Natl Lab, Washington State Univ, Natl Sci Fdn ID CRYSTALS; EQUILIBRIUM; STRESS C1 Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. Washington State Univ, Dept Mech & Mat Engn, Pullman, WA 99164 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Srolovitz, DJ (reprint author), Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. NR 27 TC 13 Z9 13 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 4 PY 1998 VL 39 IS 4-5 BP 379 EP 387 DI 10.1016/S1359-6462(98)00212-7 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 113QQ UT WOS:000075563100003 ER PT J AU Hartley, CS AF Hartley, CS TI Point force models of primitive dislocation loops SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT Symposium on Defects in Crystals Honoring John Hirth at the TMS Annual Meeting CY FEB 16-19, 1998 CL SAN ANTONIO, TEXAS SP TMS, Electr Magnet & Photon Mat Div, TMS, Struct Mat Div, TMS, Chem & Phy Mat Comm, TMS, Phys Met Comm, TMS, Shaping & Forming Comm, Pacific NW Natl Lab, Washington State Univ, Natl Sci Fdn C1 Natl Inst Stand & Technol, MSEL, Div Met, Boca Raton, FL 33431 USA. Florida Atlantic Univ, Dept Mech Engn, Boca Raton, FL 33431 USA. RP Hartley, CS (reprint author), Natl Inst Stand & Technol, MSEL, Div Met, Boca Raton, FL 33431 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 4 PY 1998 VL 39 IS 4-5 BP 409 EP 415 DI 10.1016/S1359-6462(98)00215-2 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 113QQ UT WOS:000075563100006 ER PT J AU Millstein, J AF Millstein, J TI Observations of skin sloughing in the crested sculpin (Blepsias bilobus) SO COPEIA LA English DT Article C1 Natl Marine Fisheries Serv, Auke Bay Lab, Auke Bay, AK 99801 USA. RP Millstein, J (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Auke Bay, AK 99801 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 USA SN 0045-8511 J9 COPEIA JI Copeia PD AUG 3 PY 1998 IS 3 BP 743 EP 745 DI 10.2307/1447807 PG 3 WC Zoology SC Zoology GA 109WU UT WOS:000075348000023 ER PT J AU Cowley, RA Gehring, PM Gibbs, D Goff, JP Lake, B Majkrzak, CF Vigliante, A Ward, RCC Wells, MR AF Cowley, RA Gehring, PM Gibbs, D Goff, JP Lake, B Majkrzak, CF Vigliante, A Ward, RCC Wells, MR TI The magnetic phase transition of a lattice-matched holmium thin film SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID 2 LENGTH SCALES; CRITICAL FLUCTUATIONS; X-RAY; T-N; SCATTERING; ORIGIN AB Neutron and x-ray scattering measurements have been made of the magnetic phase transition in a thin single-crystal film of holmium. The 5000 Angstrom film was grown on a seed of a lutetium and yttrium alloy with a concentration chosen such that the basal plane was lattice matched to the holmium film. It was capped by 10 000 Angstrom of a similar film. The measurements below T-N gave the critical exponent beta = 0.37 +/- 0.03. Above T-N the scattering suggests that the anomalous long-length-scale scattering is at least 20 times weaker than has been observed in similar experiments on bulk and thin-film holmium. These results show that the long-length-scale scattering is associated with the crystallographic surface rather than the end of the magnetic layer. The implications of this result for the origin of this type of scattering are discussed. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Cowley, RA (reprint author), Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. OI Lake, Bella/0000-0003-0034-0964; Gehring, Peter/0000-0002-9236-2046 NR 16 TC 4 Z9 4 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD AUG 3 PY 1998 VL 10 IS 30 BP 6803 EP 6812 DI 10.1088/0953-8984/10/30/018 PG 10 WC Physics, Condensed Matter SC Physics GA 109MF UT WOS:000075325800018 ER PT J AU Quinn, GD AF Quinn, GD TI Hardness testing of ceramics SO ADVANCED MATERIALS & PROCESSES LA English DT Article C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Quinn, GD (reprint author), NIST, Div Ceram, Bldg 223-A329, Gaithersburg, MD 20899 USA. NR 0 TC 18 Z9 18 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD AUG PY 1998 VL 154 IS 2 BP 23 EP 27 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 109KD UT WOS:000075320700003 ER PT J AU Battaglia, F Kulkarni, AK Feng, JZ Merkle, CL AF Battaglia, F Kulkarni, AK Feng, JZ Merkle, CL TI Simulations of planar flapping jets in confided channels SO AIAA JOURNAL LA English DT Article ID SYMMETRIC SUDDEN EXPANSION; FLOW AB Computational analyses are used to provide a more complete understanding of the mechanisms that contribute to the development of oscillating planar jets. The geometry considered is a two-dimensional jet exhausting into a blind channel, whose open end is opposite to the initial direction such that the jet must turn through 180 deg to exit. The resulting flowfields exhibit three distinct characters that depend on the channel expansion ratio and the Reynolds number. At low Reynolds numbers the flow is steady and symmetric. A symmetry-breaking bifurcation at intermediate Reynolds numbers produces steady asymmetric flows. A Hopf bifurcation at higher Reynolds numbers yields unsteady flows. Predicted critical Reynolds numbers and oscillation frequencies are presented for different expansion ratios. Solutions are obtained from the time-dependent Navier-Stokes equations by means of an incompressible formulation based on dual-time stepping via artificial compressibility. C1 Penn State Univ, Dept Engn Mech, University Pk, PA 16802 USA. RP Battaglia, F (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RI Battaglia, Francine/E-9189-2014 OI Battaglia, Francine/0000-0002-0380-3402 NR 16 TC 4 Z9 4 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 1998 VL 36 IS 8 BP 1425 EP 1431 DI 10.2514/2.533 PG 7 WC Engineering, Aerospace SC Engineering GA 105HJ UT WOS:000075066400011 ER PT J AU Jacobson, KC Thurman, J Schmidt, CM Rickel, E De Ferreira, JO Ferreira-da-Cruz, MD Daniel-Ribeiro, CT Howard, RF AF Jacobson, KC Thurman, J Schmidt, CM Rickel, E De Ferreira, JO Ferreira-da-Cruz, MD Daniel-Ribeiro, CT Howard, RF TI A study of antibody and T cell recognition of rhoptry-associated protein-1 (RAP-1) and RAP-2 recombinant proteins and peptides of Plasmodium falciparum in migrants and residents of the state of Rondonia, Brazil SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID INHIBITORY MONOCLONAL-ANTIBODIES; CHABAUDI-CHABAUDI; IMMUNE-RESPONSES; SURFACE-ANTIGEN; MALARIA; ERYTHROCYTE; SEQUENCE; IMMUNOGENICITY; PROTECTION; INFECTION AB Humoral and cellular responses were examined among natives and migrants in an area of the Amazon region of Brazil. Rhoptry-associated protein-1 (RAP-1) and RAP-2 expressed in Escherichia coli expression systems, a peptide corresponding to the epitope bound by inhibitory anti-RAP-1 antibodies, and four other RAP-1 and RAP-2 synthetic peptides were used in these studies. Plasma from the native population had greater IgG reactivity to the N-terminal third of RAP-1 than the migrant population; both populations had low levels of IgM to this region of RAP-1. The IgG reactivity to RAP-2 and to the C-terminal third of RAP-1, as well as for all the peptides, including the peptide from the inhibitory domain, were low or absent in both populations. In contrast, there were a high number of subjects with an IgM response to the peptides. Cellular responses were measured by proliferation of peripheral blood mononuclear cells (PBMC) and, in some subjects, by reverse transcription-polymerase chain reaction for interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-4, and IL-10. Proliferation of PBMC was low when stimulated by recombinant proteins, peptides, or parasite lysate. Both RAP-1 and RAP-2 stimulated cytokine production by donor T cells; IL-2, IL-4, and IFN-gamma RNA transcripts were observed in response to recombinant proteins and parasite lysate, but with no uniform trends. From the observed antibody responses, RAP-1 appears to be more immunogenic than RAP-2. C1 Seattle Biomed Res Inst, Seattle, WA 98117 USA. FIOCRUZ, Inst Oswaldo Cruz, Dept Immunol, BR-21045900 Rio De Janeiro, Brazil. Univ Washington, Dept Pathobiol, Seattle, WA 98195 USA. RP Jacobson, KC (reprint author), NOAA, NMFS, NWFSC, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. FU NIAID NIH HHS [AI-32620] NR 37 TC 10 Z9 10 U1 0 U2 0 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD AUG PY 1998 VL 59 IS 2 BP 208 EP 216 PG 9 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA 109NN UT WOS:000075329000005 PM 9715934 ER PT J AU Salit, ML Turk, GC AF Salit, ML Turk, GC TI A drift correction procedure SO ANALYTICAL CHEMISTRY LA English DT Article ID SPECTROSCOPY AB A procedure is introduced that can mitigate the deleterious effect of low frequency noise-often termed drift-on the precision of an analytical experiment. This procedure offers several performance benefits over traditional designs based on the periodic measurement of standards to diagnose and correct for variation in instrument response, Using repeated measurements of every sample as a drift diagnostic, as opposed to requiring the periodic measurement of any given sample or standard, the analyst can better budget the measurement time to be devoted to each sample, distributing it to optimize the uncertainty of the analytical result. The drift is diagnosed from the repeated measurements, a model of the instrument response drift is constructed, and the data are corrected to a "drift-free" condition. This drift-free condition allows data to be accumulated over long periods of time with little or no loss in precision due to drift. More than 10-fold precision enhancements of analytical atomic emission results have been observed, with no statistically significant effects on the means. The procedure is described, performance data are presented, and matters regarding the procedure are discussed. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Salit, ML (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 9 TC 49 Z9 49 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1998 VL 70 IS 15 BP 3184 EP 3190 DI 10.1021/ac980095b PG 7 WC Chemistry, Analytical SC Chemistry GA 107VQ UT WOS:000075232000022 PM 21644656 ER PT J AU Hanley, HJM AF Hanley, HJM TI 'Satan, Sin and Death' - Sources for Milton's 1st illustrator, and for Hogarth SO APOLLO-THE INTERNATIONAL MAGAZINE OF THE ARTS LA English DT Article C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Hanley, HJM (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 32 TC 0 Z9 0 U1 0 U2 0 PU APOLLO MAGAZINE LTD PI LONDON PA 29 CHESHAM PLACE, LONDON, ENGLAND SW1X 8HB SN 0003-6536 J9 APOLLO JI Apollo-Int. Mag. Arts PD AUG PY 1998 VL 148 IS 438 BP 35 EP 40 PG 6 WC Art SC Art GA 109PJ UT WOS:000075331400007 ER PT J AU Woicik, JC Gupta, JA Watkins, SP Crozier, ED AF Woicik, JC Gupta, JA Watkins, SP Crozier, ED TI Bond-length strain in buried Ga1-xInxAs thin-alloy films grown coherently on InP(001) SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; SEMICONDUCTOR ALLOYS; SOLID-SOLUTIONS; LAYERS; HETEROSTRUCTURES AB The bond lengths in a series of strained, buried Ga1-xInxAs thin-alloy films grown coherently on InP(001) have been determined by high-resolution extended x-ray absorption fine-structure measurements. Comparison with a random-cluster calculation demonstrates that the external in-plane epitaxial strain imposed by pseudomorphic growth opposes the natural bond-length distortions due to alloying. (C) 1998 American Institute of Physics. [S0003-6951(98)03235-5]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. RP Woicik, JC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 22 TC 25 Z9 25 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG PY 1998 VL 73 IS 9 BP 1269 EP 1271 DI 10.1063/1.122371 PG 3 WC Physics, Applied SC Physics GA 249UL UT WOS:000083351600035 ER PT J AU Kelly, R Miotello, A Mele, A Guidoni, AG Hastie, JW Schenck, PK Okabe, H AF Kelly, R Miotello, A Mele, A Guidoni, AG Hastie, JW Schenck, PK Okabe, H TI Gas-dynamic effects in the laser-pulse sputtering of AlN: is there evidence for phase explosion? SO APPLIED SURFACE SCIENCE LA English DT Article DE thermodynamic critical temperature; AlN; fluorescence ID ALUMINUM NITRIDE; PARTICLE-EMISSION; ABLATION PLUMES; KNUDSEN-LAYER; FILMS; VACUUM; DESORPTION; POLYMERS; SURFACE; COPPER AB The overall light intensity (fluorescence) of the sputtered atoms, ions, and molecules has been measured for polycrystalline AlN which was bombarded with 248 nm laser pulses in the presence of a background pressure of N-2. AlN is unusual in that, in spite of a similar to 6 eV band gap, it is easily rendered highly absorptive of 248, 308, or 694 nm laser pulses. In fact, since it is well established in other work that similar to 1.5 J/cm(2) (308 nm) brings AIN to the melting temperature, similar to 3050 K, we will assume that the fluence used here(similar to 20 J/cm(2)) was more than enough to bring the target surface first to a temperature sufficient for normal vaporization but finally to the vicinity of the thermodynamic critical temperature, T-tc. As a result a significant quantity of particles can be assumed to have been expelled by phase explosion. The tentativeness in the argument rests in the problem that some part of the incident fluence beyond similar to 1.5 J/cm(2) will have been consumed in laser-plume interaction. Nevertheless there is evidence in work by Pedraza et al. [A.J. Pedraza, J-Y. Zhang, H. Esrom, Mater. Res. Sec. Symp. Proc. 285 (1993) 209] that both AIN and Al respond linearly to the fluence up to at least 6 J/cm(2). It was found that the assumed phase-exploded particles decelerated rapidly, possibly due to their encounter with the normally vaporized particles, or possibly due to an electric field arising from positive charging of the target surface. The fluorescence maximum (which can be safely assumed to be also a density maximum) was then nearly stationary, a situation which characterized the lowest background pressures of N-2 (less than or equal to 3.5 Pa). At higher pressures (greater than or equal to 3.5 Pa) a second fluorescence maximum appeared nearer the contact front and was found to move. Following the suggestion of Horwitz (1) we take this feature as being an artifact of electrons near the contact front diffusing (or scattering) backwards and causing fluorescence which is unrelated to the particle density. From the velocity of the contact front one obtains explicit information on the mean kinetic energies (E-4) of the particles in the plume (1.5-2 eV), Another estimate of E-4 follows from the initial expansion observed from 0-200 ns (1.5-3 eV). Such energies suggest, independently of the fact that the fluence was high (similar to 20 J/cm(2)), that a temperature near T-tc was reached and that phase explosion may have occurred. We finally note that, however tentative is the claim for phase explosion, it is certain that a close relative of phase explosion, due to subsurface heating, was not involved. This is because the numerical demonstrations of subsurface heating have been flawed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Trent, INFM, I-38050 Trento, Italy. Univ Trent, Dipartimento Fis, I-38050 Trento, Italy. Univ Roma La Sapienza, Dipartimento Chim, I-00185 Rome, Italy. NIST, Div Ceram, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. RP Univ Trent, INFM, I-38050 Trento, Italy. NR 77 TC 21 Z9 22 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 EI 1873-5584 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1998 VL 133 IS 4 BP 251 EP 269 DI 10.1016/S0169-4332(98)00203-7 PG 19 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 104UL UT WOS:000075034100004 ER PT J AU Brandt, JC Heap, SR Beaver, EA Boggess, A Carpenter, KG Ebbets, DC Hutchings, JB Jura, M Leckrone, DS Linsky, JL Maran, SP Savage, BD Smith, AM Trafton, LM Walter, FM Weymann, RJ Snow, M Ake, TB Hogen, RH AF Brandt, JC Heap, SR Beaver, EA Boggess, A Carpenter, KG Ebbets, DC Hutchings, JB Jura, M Leckrone, DS Linsky, JL Maran, SP Savage, BD Smith, AM Trafton, LM Walter, FM Weymann, RJ Snow, M Ake, TB Hogen, RH TI An ultraviolet spectral atlas of 10 lacertae obtained with the Goddard High Resolution Spectrograph on the Hubble Space Telescope SO ASTRONOMICAL JOURNAL LA English DT Article DE atlases; stars : early-type; stars : individual (10 Lacertae) ID INTERSTELLAR ABSORPTION-LINES; O-STARS; MILKY-WAY; B-STARS; CALIBRATION; VELOCITIES AB Observations of the narrow-lined O-type star 10 Lacertae taken with the Goddard High Resolution Spectrograph in 1992 November are presented. The spectra cover the wavelength range 1181-1777 Angstrom with a resolution of 15 km s(-1) and signal-to-noise ratio greater than 100:1. Absorption lines arising in the interstellar medium, the photosphere, and the stellar wind are identified and discussed. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Ball Aerosp & Technol Corp, Boulder, CO 80306 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. NASA, Space Sci Directorate, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Texas, Mcdonald Observ, Austin, TX 78712 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Sci Program, Comp Sci Corp, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brandt, JC (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. RI heap, sara/E-2237-2012; Carpenter, Kenneth/D-4740-2012; OI SNOW, MARTIN/0000-0001-9106-1332 NR 48 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 1998 VL 116 IS 2 BP 941 EP 971 DI 10.1086/300446 PG 31 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 115CW UT WOS:000075646800034 ER PT J AU Davis, JM Eder, BK Nychka, D Yang, Q AF Davis, JM Eder, BK Nychka, D Yang, Q TI Modeling the effects of meteorology on ozone in Houston using cluster analysis and generalized additive models SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE ozone; cluster analysis; meteorology; generalized additive models; Houston ID SYNOPTIC CLIMATOLOGICAL CLASSIFICATION; UNITED-STATES; TRENDS AB This paper compares the results from a !;ingle-stage clustering technique (average linkage) with those of a two-stage technique (average linkage then k-means) as art of an objective meteorological classification scheme designed to better elucidate ozone's dependence on meteorology in the Houston, Texas, area. When applied to twelve years of meteorological data (1981-1992), each clustering technique identified seven statistically distinct meteorological regimes. The majority of these regimes exhibited significantly different daily 1 h maximum ozone (O-3) concentrations, with the two-stage approach resulting in a better segregation of the mean concentrations when compared to the single-stage approach. Both approaches indicated that the largest daily Ih maximum concentrations are associated with migrating anticyclones that occur most often during spring and summer, and not with the quasi-permanent Bermuda High that often dominates the southeastern United States during the summer. ns a result, maximum ozone concentrations are just as likely during the months of April, May, September and October as they are during the summer months. Generalized additive models were then developed within each meteorological regime in order to identify those meteorological covariates most closely associated with O-3 concentrations. Three surface wind covariates: speed, and the u and v components were selected nearly unanimously in those meteorological regimes dominated by anticyclones, indicating the importance of transport within these O-3 conducive meteorological regimes. Published by Elsevier Science Ltd. C1 Natl Inst Stat Sci, Res Triangle Pk, NC USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC USA. NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC USA. N Carolina State Univ, Dept Stat, Raleigh, NC USA. RP Davis, JM (reprint author), Natl Inst Stat Sci, Res Triangle Pk, NC USA. NR 23 TC 67 Z9 70 U1 1 U2 7 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 AUG PY 1998 VL 32 IS 14-15 BP 2505 EP 2520 DI 10.1016/S1352-2310(98)00008-9 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 101LQ UT WOS:000074870800009 ER PT J AU Conny, JM AF Conny, JM TI The isotopic characterization of carbon monoxide in the troposphere SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE carbon-14; carbon-13; oxygen-18; isotope fractionation; kinetic isotope effect ID ATMOSPHERIC (CO)-C-14; LATITUDINAL DISTRIBUTION; SOUTHERN-HEMISPHERE; EARTHS ATMOSPHERE; CO; OH; FRACTIONATION; HYDROCARBONS; ABUNDANCE; CHEMISTRY AB The distributions of stable isotopes in trace atmospheric species are controlled mainly by the isotopic compositions of precursor molecules and isotope fractionation effects during production and removal of the species. Distributions of radioactive isotopes are controlled mainly by the isotopic compositions of precursor molecules and radioactive decay processes. As a result, through their isotopic compositions, atmospheric species are traceable to sources and sinks. Thus, isotopic compositions provide useful information for estimating source strengths and for understanding the importance of removal processes in the cycling of the species. The use of radioactive C-14 and the stable isotopes (C-13 and O-18) are reviewed here for understanding production and removal processes of CO in the troposphere. Carbon monoxide is a critical component in atmospheric chemistry because of its large effect on levels of OH, the principal oxidant in the atmosphere. In the troposphere, this is due to relatively high concentrations of CO and a short lifetime (2-4 months). Initially, (CO)-C-14 measurements were instrumental in estimating accurately the tropospheric lifetime. Since seasonal (CO)-C-14 variation is controlled largely by OH,(CO)-C-14 serves as an important surrogate measure of tropospheric OH. Global (CO)-C-14 measurements have also been used to estimate the biogenic component of the global GO budget, specifically contributions from biomass burning, oxidized non-methane hydrocarbon (NMHC) emissions, oceans and plants. Research using (CO)-C-14 measurements is also active in quantifying fossil and non-fossil urban emissions. Kinetic isotopic fractionation during production of (CO)-C-13 and (CO)-O-18 from reduced precursors allows one to distinguish, at least qualitatively, different varieties of CO based on seasonal tropospheric isotopic measurements. Difficulties in interpreting the stable isotopic record arise from large fractionation effects that obscure source isotopic signatures (in particular the oxygen kinetic isotope effect for the CO + OH reaction), and large seasonal/latitudinal variability in source fluxes. While dual-isotopic CO source signatures do not allow a direct mathematical determination of contributions from several sources, plots of delta(18)O vs delta(13)C may help estimate relative proportions of dominant sources. In addition to understanding CO sources, the pressure dependence of the carbon kinetic isotope effect (KIE) has helped elucidate pathways for the CO + OH reaction. Since formaldehyde (HCHO) is an important intermediate in hydrocarbon oxidation to CO and CO2, the stable carbon and oxygen isotopes in atmospheric HCHO may help distinguish different hydrocarbon sources to regional CO budgets and elucidate the importance of different oxidative reaction pathways. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Conny, JM (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Chem B364, Gaithersburg, MD 20899 USA. NR 70 TC 11 Z9 11 U1 0 U2 7 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 AUG PY 1998 VL 32 IS 14-15 BP 2669 EP 2683 DI 10.1016/S1352-2310(97)00398-1 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 101LQ UT WOS:000074870800023 ER PT J AU Bilby, RE Fransen, BR Bisson, PA Walter, JK AF Bilby, RE Fransen, BR Bisson, PA Walter, JK TI Response of juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) to the addition of salmon carcasses to two streams in southwestern Washington, USA SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID STABLE ISOTOPES; BRITISH-COLUMBIA; SPAWNING STREAMS; PACIFIC SALMON; SMOLT SIZE; SURVIVAL; CREEK; GROWTH; DECOMPOSITION; RIVER AB Availability of organic matter and nutrients transported from the marine environment to streams by spawning salmon was increased in two small streams in southwestern Washington, U.S.A., by adding salmon carcasses from a nearby hatchery. Response of juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) rearing at these sites was compared with nearby streams where few salmon spawned. Densities of age 0(+) coho salmon and age 0(+) and age 1(+) steelhead increased following carcass additions to the treated streams. A similar increase in density was not observed at the reference sites. Condition factors in treated streams increased following carcass addition and remained at high levels while carcasses were present whereas no similar pattern was observed at the reference sites. Stomach contents of fish in streams to which carcasses had been added consisted primarily of salmon eggs and carcass flesh when carcasses were present in the stream. Stable isotope analysis indicated that the proportion of marine-derived nitrogen in the muscle tissue of juvenile salmonids increased as much as 39% following carcass placement. Results suggest that eggs and carcasses of adult salmon provide a very important resource during a period when other food items are often scarce. C1 Weyerhauser Co, Western Forestry Res, Tacoma, WA 98477 USA. US Forest Serv, Pacifis NW Res Stn, USDA, Olympia Forestry Sci Lab, Olympia, WA 98512 USA. RP Bilby, RE (reprint author), NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM Bob.Bilby@noaa.gov NR 41 TC 152 Z9 152 U1 3 U2 23 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 1998 VL 55 IS 8 BP 1909 EP 1918 DI 10.1139/cjfas-55-8-1909 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 129QQ UT WOS:000076474800013 ER PT J AU Watson, DE Reichert, W Di Giulio, RT AF Watson, DE Reichert, W Di Giulio, RT TI Induction of hepatic CYP1A in channel catfish increases binding of 2-aminoanthracene to DNA in vitro and in vivo SO CARCINOGENESIS LA English DT Article ID FLAVIN-CONTAINING MONOOXYGENASE; PROSTAGLANDIN-H SYNTHASE; P-32 POSTLABELING ASSAY; AROMATIC-AMINES; ADDUCTS; ACTIVATION; RAT; ENHANCEMENT; CELLS; CDNA AB Data are presented from in vitro and in vivo studies that indicate cytochrome P4501A (CYP1A) in channel catfish (Ictalurus punctatus) hepatic tissue activates 2-aminoanthracene (AA) to a reactive metabolite that binds to DNA, Channel catfish were injected i.p. with vehicle or 10 mg/kg beta-naphthoflavone (beta NF) on two consecutive days. Two days after the final injection of vehicle or beta NF, vehicle or [H-3]AA was injected i.p. at 10 mg/kg, creating four different treatments: vehicle only, beta NF only, [H-3]AA only, and beta NF/[H-3]AA, Hepatic tissue was examined for CYP1A-associated ethoxyresorufin-O-de-ethylase (EROD) activity, and for DNA adducts at 1, 2, 4 and 7 days following administration of vehicle or [H-3]AA. Hepatic EROD activity in beta NF-treated fish was 17-fold higher at day 0 and remained significantly greater than untreated animals for the 7-day experiment. Hepatic DNA adducts, as measured by tritium-associated DNA, ranged from 4.8 to 8.6 pmol/mg DNA in vehicle-pretreated fish injected with [H-3]AA, but ranged from 12.6 to 22.7 pmol/mg DNA in beta NF-pretreated fish injected with [H-3]AA, Thus, pretreatment with beta NF significantly increased binding of [H-3]AA to hepatic DNA in vivo at all four times. Analysis by P-32-post-labeling and thin layer chromatography of hepatic DNA from channel catfish treated with AA revealed two major and several minor spots, which are indicative of DNA adduct formation. Hepatic microsomes from beta NF-pretreated fish were more effective at catalysing the binding of [H-3]AA to DNA in vitro than were microsomes from non-treated fish, In addition, binding was decreased by the CYP1A inhibitor 3,3',4,4'-tetrachlorobiphenyl. Collectively, these data demonstrate that CYP1A is involved in the activation of AA in channel catfish. C1 Duke Univ, Ecotoxicol Lab, Nicholas Sch Environm, Durham, NC 27708 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Di Giulio, RT (reprint author), NIEHS, Mail Drop F1-08,POB 12233, Res Triangle Pk, NC 27709 USA. FU NIEHS NIH HHS [T32ES07031-15S1] NR 45 TC 5 Z9 6 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD AUG PY 1998 VL 19 IS 8 BP 1495 EP 1501 DI 10.1093/carcin/19.8.1495 PG 7 WC Oncology SC Oncology GA 111TW UT WOS:000075454900025 PM 9744548 ER PT J AU Kleiman, VD Arrivo, SM Melinger, JS Heilweil, EJ AF Kleiman, VD Arrivo, SM Melinger, JS Heilweil, EJ TI Controlling condensed-phase vibrational excitation with tailored infrared pulses SO CHEMICAL PHYSICS LA English DT Article ID LASER-PULSES; SELECTIVE EXCITATION; FEMTOSECOND PULSES; SCATTERING; DYNAMICS; LADDER AB Vibrational population distributions within the CO-stretching T-1u manifold of W(CO)(6) in room-temperature n-hexane were created by using near-transform limited and linearly chirped picosecond infrared excitation pulses. These pulses were characterized using the second harmonic FROG (frequency-resolved optical gating) algorithm to determine the similar to 8 cm(-1)/ps chirp for both positively- and negatively-chirped 2 ps pulses. FROG and time-resolved transient difference spectra were obtained with an InSb focal plane array detector. While unchirped and positively-chirped excitation leads predominantly to upsilon = 1 population, negatively-chirped pulses produce excess population in the Li = 2 level. These results are compared to predictions from density matrix calculations for a model potential. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. USN, Res Lab, Div Condensed Matter & Radiat Sci, Washington, DC 20375 USA. RP Heilweil, EJ (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Kleiman, Valeria/H-7818-2013 OI Kleiman, Valeria/0000-0002-9975-6558 NR 24 TC 49 Z9 49 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD AUG 1 PY 1998 VL 233 IS 2-3 BP 207 EP 216 DI 10.1016/S0301-0104(97)00367-4 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108HU UT WOS:000075260900006 ER PT J AU Hendricks, JH Aquino, MI Maslar, JE Zachariah, MR AF Hendricks, JH Aquino, MI Maslar, JE Zachariah, MR TI Metal and ceramic thin film growth by reaction of alkali metals with metal halides: A new route for low-temperature chemical vapor deposition SO CHEMISTRY OF MATERIALS LA English DT Article ID TITANIUM; TIN; HYDROGEN; SI(100); TISI2; TOOL AB A new low-temperature chemical vapor deposition (CVD) method for the growth of metal and ceramic thin films has been demonstrated. This method involves the use of a low-pressure coflow diffusion reactor to react alkali metal vapor with metal halide vapor. The reaction chemistry is described by the following general equation: mnNa + nMX(m) -->(Ar) M-n + nmNaX. Here, Na is an alkali metal (e.g. Na, K, Cs, or Rb), M is a metal(e.g. Ti, Ta, Pt, W,...) or nonmetal (e.g. B, C, Si,...), X is a halogen (e.g. F, Cl, Br, or I), Ar is an inert gas (e.g. Ar or He), and m and n. are integers. In this reaction, the alkali metal strips halogen from the metal halide. The metal is then free to grow into a thin film on a substrate placed in the reaction zone. Metal nitride or metal oxide ceramic films are easily formed by the introduction of nitrogen or oxygen gases into the reactor. Previously, this technique has been successfully employed for the production of nanoparticles and as an industrial synthesis route for the reduction of bulk metals from their metal halides. Now, for the first time, this reaction chemistry has been demonstrated to be a viable technique for thin film growth as well. Using the precursors of sodium metal vapor, titanium tetrachloride (the limiting reagent), and either Ar or Nz gas, salt-free titanium (Ti), titanium nitride (TiN), and titanium silicide (Ti,Si,) thin films have been grown on copper and silicon substrates. Guided by theoretical modeling calculations, reactant concentrations were adjusted to prevent gasphase particle nucleation and growth. Using this technique, we have produced salt-free titanium and titanium nitride thin films on copper substrates heated to 610 degrees C. This temperature is considerably lower than the 900-1200 degrees C required for the conventional thermal CVD of titanium. A composite salt/Ti film was grown on a silicon wafer at 260 degrees C, while at 610 degrees C, a salt-free titanium silicide thin film was produced. The quality and composition of the thin films were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). C1 Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Zachariah, MR (reprint author), Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. NR 34 TC 19 Z9 20 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1998 VL 10 IS 8 BP 2221 EP 2229 DI 10.1021/cm980161q PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 112QE UT WOS:000075504900032 ER PT J AU Rea, LD Castellini, MA Fadely, BS Loughlin, TR AF Rea, LD Castellini, MA Fadely, BS Loughlin, TR TI Health status of young Alaska Steller sea lion pups (Eumetopias jubatus) as indicated by blood chemistry and hematology SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY LA English DT Article DE nutritional condition; plasma metabolites; pinnipeds; marine mammals; fasting; neonates; ketone bodies; blood urea nitrogen ID PLASMA; HEMATOCRIT AB Blood chemistry and hematology were examined in 238 Steller sea lion pups (Eumetopias jubatus) to assess the health status of pups < 1 month of age. Failure of juvenile recruitment (possibly due to nutritionally or physiologically compromised pups) into breeding populations has been proposed as a cause of recent declines of this endangered species in Alaska. To identify potential correlations with areas of high population decline, blood chemistry data were considered for three areas: eastern Aleutian Islands (low rates of population decline to stable populations), Gulf of Alaska (high rates of decline), and Southeast Alaska (stable to increasing population). Southeast Alaska pups showed elevated ketone body concentrations (beta-hydroxybutyrate, (beta-HBA)) and depressed glucose levels when compared with animals from the Aleutian Islands and lower blood urea nitrogen (BUN) and glucose levels than pups in the Gulf of Alaska. Over 40% of the pups from Southeast Alaska had elevated beta-HBA concentrations suggesting they underwent longer periods of fasting than seen in pups from other areas. Hematocrit (Hct), hemoglobin concentration (Hb) and water content of the blood exhibited typical mammalian relationships. In summary, blood chemistry and hematology data showed no indication that Steller sea lion pups < 1 month old from areas of population decline were nutritionally compromised. (C) 1998 Elsevier Science Inc. All rights reserved. C1 Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Rea, LD (reprint author), Univ Alaska, Inst Marine Sci, POB 757220, Fairbanks, AK 99775 USA. RI Fadely, Brian/P-3601-2015 OI Fadely, Brian/0000-0002-9172-1887 NR 33 TC 48 Z9 49 U1 0 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1095-6433 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Mol. Integr. Physiol. PD AUG PY 1998 VL 120 IS 4 BP 617 EP 623 DI 10.1016/S1095-6433(98)10074-0 PG 7 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA 127GE UT WOS:000076341900007 PM 10400492 ER PT J AU Bullister, JL Wisegarver, DP AF Bullister, JL Wisegarver, DP TI The solubility of carbon tetrachloride in water and seawater SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID LAW CONSTANTS; PACIFIC; OCEAN; GASES; AIR AB High precision measurements of the solubility of carbon tetrachloride (CCl4) in pure water and seawater were made over the temperature range of similar to 0-40 degrees C, For comparison with previously reported results, the solubilities of CFC-11 and CFC-12 were also measured during these experiments. The experimental data were fit by equations in temperature and salinity, in the form used in previous gas solubility studies, The CFC-11 and CFC-12 results were generally in good agreement with earlier work, although some differences were noted, For CCl4, the standard error of the measurements from the fitted curves was +/- 2.5%. The concentrations of dissolved CCl4 measured in near-surface waters on a recent long meridional section in the South Pacific Ocean (where the temperature ranged from -1 to 29 degrees C) ale compared to calculated saturation levels based on these solubility data and atmospheric levels of CCl4 measured along the section. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Bullister, JL (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 17 TC 20 Z9 21 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD AUG PY 1998 VL 45 IS 8 BP 1285 EP 1302 DI 10.1016/S0967-0637(98)00017-X PG 18 WC Oceanography SC Oceanography GA 120VP UT WOS:000075978300004 ER PT J AU Graham, DW Larsen, LM Hanan, BB Storey, M Pedersen, AK Lupton, JE AF Graham, DW Larsen, LM Hanan, BB Storey, M Pedersen, AK Lupton, JE TI Helium isotope composition of the early Iceland mantle plume inferred from the tertiary picrites of West Greenland SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE helium; isotopes; Greenland; mantle plumes; picrite ID FLOOD BASALTS; VOLCANIC-ROCKS; COSMOGENIC HELIUM; REYKJANES RIDGE; LOIHI SEAMOUNT; EVOLUTION; ISLAND; SYSTEMATICS; EARTH; GEOCHEMISTRY AB Picrites from the 61 million year old Vaigat Formation of the Nuussuaq Peninsula in West Greenland have He-3/He-4 ratios trapped in olivine phenocrysts which range up to 30 times the atmospheric ratio. These high values, measured during gas extraction by crushing in vacuum, are similar to the highest magmatic He-3/He-4 ratios found in young terrestrial volcanic rocks. By analogy with young basalts, in which crushing selectively extracts magmatic helium, any significant cosmogenic He-3 appears to be absent in these picrites. Additional evidence for the absence of cosmogenic helium is provided by fusion results on the crushed olivine powders and by a single stepwise crushing experiment, in which only magmatic and radiogenic helium components are resolvable. The West Greenland picrites have Pb, Nd and Sr isotope compositions which overlap those found in picrites from Iceland and in basalts from Loihi Seamount, localities which today also have high He-3/He-4 ratios. Isotopic variations in He, Pb, Nd and Sr for the West Greenland picrites are interpreted to largely result from interaction of the early Iceland mantle plume with the upper mantle during plume ascent and dispersion beneath the continental lithosphere. The presence of high 3He/4He ratios in West Greenland, and the onset of magmatism across the North Atlantic Volcanic Province near 62 Ma, supports the hypothesis for very rapid dispersion (>1 m/year) of mantle plume head material during the earliest stages of plume impact, as predicted in recent numerical simulations of plume behavior during thermal mantle convection with non-Newtonian rheology. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Danish Lithosphere Ctr, DK-1350 Copenhagen K, Denmark. Geol Survey Denmark & Greenland, DK-2400 Copenhagen NV, Denmark. San Diego State Univ, Dept Geol Sci, San Diego, CA 92182 USA. Geol Museum, DK-1350 Copenhagen K, Denmark. NOAA, Pacific Marine Environm Lab, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Graham, DW (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. OI Hanan, Barry/0000-0002-8240-2200; Storey, Michael/0000-0002-3126-4637; Graham, David/0000-0002-7411-1905 NR 71 TC 79 Z9 80 U1 0 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD AUG PY 1998 VL 160 IS 3-4 BP 241 EP 255 DI 10.1016/S0012-821X(98)00083-1 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 118JP UT WOS:000075835000002 ER PT J AU Ryer, CH Olla, BL AF Ryer, CH Olla, BL TI Shifting the balance between foraging and predator avoidance: the importance of food distribution for a schooling pelagic forager SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE fish behavior; risk balancing; swimming speed; walleye pollock; shoaling; Theragra chalcogramma ID POLLOCK THERAGRA-CHALCOGRAMMA; JUVENILE WALLEYE POLLOCK; EASTERN BERING SEA; ATLANTIC SALMON; VERTICAL-DISTRIBUTION; FEEDING MOTIVATION; FISH PREDATORS; SHOALING FISH; MARINE FISH; RISK AB It is widely held that when predator avoidance conflicts with other activities, such as feeding, avoidance of predators often takes precedence. In this study, we examine how predation risk and food distribution interact to influence the schooling behavior and swimming speed of foraging juvenile walleye pollock, Theragra chalcogramma. Fish were acclimated to either spatially and temporally clumped, or spatially and temporally dispersed food for 3 weeks. Fish were then monitored while feeding in the absence and presence of predatory sablefish, Anoplopoma fimbrin. Fish foraging for clumped food swam rapidly in a loose school when predators were absent, but swam more slowly and adopted more cohesive schooling in the presence of predators, trading-off foraging opportunity for decreased vulnerability to predators. Fish foraging for dispersed food swam about slowly and did not engage in cohesive schooling in either the absence or presence of predators. These fish accepted greater predation risk in order to continue foraging, suggesting that the cost of schooling, in terms of decreased foraging opportunity, was greater when food was dispersed than when it was clumped. This lower responsiveness to predators among fish receiving dispersed food demonstrates that predator avoidance does not always take precedence over other activities, but rather, that a balance is maintained between predator avoidance and feeding, which shifts as food distribution changes. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. RP Ryer, CH (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NR 52 TC 31 Z9 32 U1 1 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD AUG PY 1998 VL 52 IS 4 BP 467 EP 475 DI 10.1023/A:1007433014921 PG 9 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 109KG UT WOS:000075321100008 ER PT J AU Fairey, R Roberts, C Jacobi, M Lamerdin, S Clark, R Downing, J Long, E Hunt, J Anderson, B Newman, J Tjeerdema, R Stephenson, M Wilson, C AF Fairey, R Roberts, C Jacobi, M Lamerdin, S Clark, R Downing, J Long, E Hunt, J Anderson, B Newman, J Tjeerdema, R Stephenson, M Wilson, C TI Assessment of sediment toxicity and chemical concentrations in the San Diego Bay region, California, USA SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE sediment toxicity; pore-water toxicity; sediment chemistry; San Diego Bay, USA ID MARINE; CONTAMINATION; FLORIDA; ZINC AB Sediment quality within San Diego Bay, Mission Bay, and the Tijuana River Estuary of California was investigated as part of an ongoing statewide monitoring effort (Bay Protection and Toxic Cleanup Program). Study objectives were to determine the incidence, spatial patterns, and spatial extent of toxicity in sediments and porewater; the concentration and distribution of potentially toxic anthropogenic chemicals; and the relationships between toxicity and chemical concentrations. Rhepoxynius abronius survival bioassays, grain size, and total organic carbon analyses were performed on 350 sediment samples. Strongylocentrotus purpuratus development bioassays were performed on 164 pore-water samples. Toxicity was demonstrated throughout the San Diego Bay region, with increased incidence and concordance occurring in areas of industrial and shipping activity. Trace metal and trace synthetic organic analyses were performed on 229 samples. Copper, zinc, mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlordane were found to exceed ERM (effects range median) or PEL (probable effects level) sediment quality guidelines and were considered the six major chemicals or chemical groups of concern. Statistical analysis of the relationships between amphipod toxicity, bulk phase sediment chemistry, and physical parameters demonstrated few significant linear relationships. Significant differences in chemical levels were found between toxic and nontoxic responses using multivariate and univariate statistics. Potential sources of anthropogenic chemicals were discussed. C1 Moss Landing Marine Labs, San Jose State Fdn, Moss Landing, CA 95039 USA. NOAA, ORCA, Coastal Monitoring & Bioeffects Assessment Div, Seattle, WA 98115 USA. Univ Calif Santa Cruz, Inst Marine Sci, Dept Biochem & Chem, Santa Cruz, CA 95064 USA. Moss Landing Marine Labs, Dept Fish & Game, Moss Landing, CA 95039 USA. State Water Resources Control Board, Bay Protect Tox Cleanup Program, Sacramento, CA 92444 USA. RP Fairey, R (reprint author), Moss Landing Marine Labs, San Jose State Fdn, POB 747, Moss Landing, CA 95039 USA. EM fairey@mlml.calstate.edu RI Mason, Robert/A-6829-2011 NR 64 TC 43 Z9 44 U1 1 U2 13 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD AUG PY 1998 VL 17 IS 8 BP 1570 EP 1581 DI 10.1897/1551-5028(1998)017<1570:AOSTAC>2.3.CO;2 PG 12 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 106LK UT WOS:000075130900019 ER PT J AU Herman, RL Scott, DC Webster, CR May, RD Moyer, EJ Salawitch, RJ Yung, YL Toon, GC Sen, B Margitan, JJ Rosenlof, KH Michelsen, HA Elkins, JW AF Herman, RL Scott, DC Webster, CR May, RD Moyer, EJ Salawitch, RJ Yung, YL Toon, GC Sen, B Margitan, JJ Rosenlof, KH Michelsen, HA Elkins, JW TI Tropical entrainment time scales inferred from stratospheric N2O and CH4 observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ABSORPTION AB Simultaneous in situ measurements of N2O and CH4 were made with a tunable diode laser spectrometer (ALIAS II) aboard the Observations from the Middle Stratosphere (OMS) balloon platform from New Mexico, Alaska, and Brazil during 1996 and 1997. We find different compact relationships of CH4 with N2O in the tropics and extra-tropics because mixing is slow between these regions. Transport into the extra-tropics from the tropics or the polar vortex leads to deviations from the normal compact relationship. We use measured N2O and CH4 and a simple model to quantify entrainment of mid-latitude stratospheric air into the tropics. The entrainment time scale is estimated to be 16 (+17, -8) months for altitudes between 20 and 28 km. The fraction of tropical air entrained from the extratropical stratosphere is 50% (+18%, -30%) at 20 km, increasing to 78% (+11%, -19%) at 28 km. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO USA. Atmospher & Environm Res Inc, San Ramon, CA USA. Natl Ocean & Atmospher Adm, Climate Monitoring & Diagnost Lab, Boulder, CO USA. RP Herman, RL (reprint author), CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. EM rherman@gps.caltech.edu RI Salawitch, Ross/B-4605-2009; Herman, Robert/H-9389-2012; Rosenlof, Karen/B-5652-2008 OI Salawitch, Ross/0000-0001-8597-5832; Herman, Robert/0000-0001-7063-6424; Rosenlof, Karen/0000-0002-0903-8270 NR 25 TC 44 Z9 44 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 2781 EP 2784 DI 10.1029/98GL02109 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900006 ER PT J AU Delworth, TL Mehta, VM AF Delworth, TL Mehta, VM TI Simulated interannual to decadal variability in the tropical and sub-tropical North Atlantic SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN-ATMOSPHERE MODEL AB The dominant pattern of tropical and subtropical North Atlantic sea surface temperature (SST) anomalies simulated in the GFDL coupled ocean-atmosphere model is identified and compared to observations. The spatial pattern and temporal variability of that pattern resemble observational results. On interannual time scales it is shown that anomalous surface heat fluxes, consistent with variations in the intensity of the subtropical high pressure system in the atmosphere and the associated Northeasterly Trade winds, appear to be the most important process for generating this SST pattern. This relationship is also true on decadal time scales, although the relative role of oceanic heat advection is somewhat larger than on the interannual time scales. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Maryland, NASA, Joint Ctr Earth Syst Sci, Dept Meteorol, College Pk, MD 20742 USA. RP Delworth, TL (reprint author), NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. EM td@gfdl.gov; mehta@atmos.umd.edu RI Delworth, Thomas/C-5191-2014 NR 9 TC 14 Z9 14 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 2825 EP 2828 DI 10.1029/98GL02188 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900017 ER PT J AU Baker, DN Pulkkinen, TI Li, X Kanekal, SG Ogilvie, KW Lepping, RP Blake, JB Callis, LB Rostoker, G Singer, HJ Reeves, GD AF Baker, DN Pulkkinen, TI Li, X Kanekal, SG Ogilvie, KW Lepping, RP Blake, JB Callis, LB Rostoker, G Singer, HJ Reeves, GD TI A strong CME-related magnetic cloud interaction with the Earth's magnetosphere: ISTP observations of rapid relativistic electron acceleration on May 15, 1997 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATION BELT; ENERGIZATION; INSTRUMENT AB A geoeffective magnetic cloud impacted the Earth early on 15 May 1997. The cloud exhibited strong initial southward interplanetary magnetic field (B(z)similar to-25 nT), which caused intense substorm activity and an intense geomagnetic storm (Dst similar to-170 nT). SAMPEX data showed that relativistic electrons (E greater than or equal to 1.0 MeV) appeared suddenly deep in the magnetosphere at L=3 to 4. These electrons were not directly "injected" from higher altitudes (i.e., from the magnetorail), nor did they come from an interplanetary source. The electron increase was preceded (for similar to 2 hrs) by remarkably strong low-frequency wave activity as seen by CANOPUS ground stations and by the GOES-8 spacecraft at geostationary orbit. POLAR/CEPPAD measurements support the result that high-energy electrons suddenly appeared deep in the magnetosphere. Thus, these new multi-point data suggest that strong magnetospheric waves can quickly and efficiently accelerate electrons to multi-MeV energies deep in the radiation belts on timescales of tens of minutes. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Aerospace Corp, Los Angeles, CA 90009 USA. Langley Res Ctr, Hampton, VA 23681 USA. Univ Alberta, Edmonton, AB T6G 2J1, Canada. NOAA, Space Environm Ctr, Boulder, CO 80302 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Baker, DN (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr, Boulder, CO 80303 USA. RI Reeves, Geoffrey/E-8101-2011; Pulkkinen, Tuija/D-8403-2012 OI Reeves, Geoffrey/0000-0002-7985-8098; Pulkkinen, Tuija/0000-0002-6317-381X NR 17 TC 95 Z9 99 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 2975 EP 2978 DI 10.1029/98GL01134 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900055 ER PT J AU Laakso, H Fairfield, DH Russell, CT Clemmons, JH Singer, HJ Giles, BL Lepping, RP Mozer, FS Pfaff, RF Tsuruda, K Wygant, JR AF Laakso, H Fairfield, DH Russell, CT Clemmons, JH Singer, HJ Giles, BL Lepping, RP Mozer, FS Pfaff, RF Tsuruda, K Wygant, JR TI Field-line resonances triggered by a northward IMF turning SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID KELVIN-HELMHOLTZ INSTABILITY; ELECTRIC-FIELD; MAGNETOSPHERE; MAGNETOPAUSE; ISEE-1; WAVES AB A sudden northward rotation of the IMF observed by IMP 8 near the bow shock at 21:22 UT on January 10, 1997, triggered surface waves and fast mode waves at the flanks of the duskside magnetosphere, as observed by GEOTAIL instruments. The power spectral density of these Raves peaked in the frequency range where field-line resonances were observed by the POLAR satellite in the region L = 6.6-10.2.. The oscillation periods of the observed field-line resonances were L-dependent with two distinct peaks which may be explained by increased heavy ion content at those field lines. The ULF waves also caused enhanced low-energy ion fluxes from the ionosphere. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Aerospace, Los Angeles, CA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. NOAA RESE, Space Environm Ctr, Boulder, CO 80303 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 299, Japan. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Laakso, H (reprint author), Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. RI Pfaff, Robert/F-5703-2012; OI Pfaff, Robert/0000-0002-4881-9715; Clemmons, James/0000-0002-5298-5222; Russell, Christopher/0000-0003-1639-8298 NR 14 TC 9 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 2991 EP 2994 DI 10.1029/98GL51034 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900059 ER PT J AU Laakso, H Fairfield, DH Collier, MR Opgenoorth, H Phan, TD Sibeck, DG Giles, BL Singer, HJ Lepping, RP Lin, RP Mozer, FS Pfaff, RF Tsuruda, K Wygant, JR AF Laakso, H Fairfield, DH Collier, MR Opgenoorth, H Phan, TD Sibeck, DG Giles, BL Singer, HJ Lepping, RP Lin, RP Mozer, FS Pfaff, RF Tsuruda, K Wygant, JR TI Oscillations of magnetospheric boundaries driven by IMF rotations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BOW SHOCK; DAYSIDE MAGNETOPAUSE; MOTION AB The arrival of the magnetic cloud on January 10, 1997, 01:05 UT, was preceded by a 12-hour interval of increased fluctuations in the IMF orientation, which drove boundary oscillations in the magnetosphere. The GEOTAIL spacecraft, initially located near the dawnside magnetopause, experienced multiple crossings of the magnetopause; at the geosynchronous distance, GOES 9 observed weak perturbations associated with these oscillations. During this time, the POLAR spacecraft, encountered the dense high-latitude boundary layer, followed by several rapid encounters with the tenuous lobe. The boundary between the mantle and the lobe was observed to be thin as the crossings lasted only 30 seconds. The source of these boundary oscillations is magnetosheath pressure variations produced by rapid IMF directional changes. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NOAA RESE, Space Environm Ctr, Boulder, CO 80302 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 299, Japan. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Inst Rymdfysik, Uppsala, Sweden. RP Laakso, H (reprint author), Finnish Meteorol Inst, POB 503, FIN-00101 Helsinki, Finland. RI Sibeck, David/D-4424-2012; Pfaff, Robert/F-5703-2012; Collier, Michael/I-4864-2013 OI Pfaff, Robert/0000-0002-4881-9715; Collier, Michael/0000-0001-9658-6605 NR 11 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 3007 EP 3010 DI 10.1029/98GL50916 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900063 ER PT J AU Wu, JG Lundstedt, H Wintoft, P Detman, TR AF Wu, JG Lundstedt, H Wintoft, P Detman, TR TI Neural network models predicting the magnetospheric response to the 1997 January halo-CME event SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIME AB A magnetic cloud associated with the 1997 January 6 halo coronal mass ejection (CME) impacted the magnetosphere on January 10. With the WIND solar wind observations we make predictions 1-3 hours ahead of the magnetospheric response (Dst) to the halo-CME event. The recently developed neural network models with different solar wind input parameters are applied in this study. A major geomagnetic storm triggered by the cloud is accurately predicted by the models with inputs: (a) P-1/2, VBz, (b) B, N, V, B-s, and (c) B, B-y, B-z, N, V. Further, the three models can predict the effect of the density enhancement at the rear of the cloud which might be associated with the disappearing filament observed on January 6, 1997. C1 Lund Observ, Solar Terr Phys Div, Swedish Inst Space Phys, S-22100 Lund, Sweden. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Wu, JG (reprint author), Lund Observ, Solar Terr Phys Div, Swedish Inst Space Phys, Box 43, S-22100 Lund, Sweden. NR 9 TC 3 Z9 3 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 3031 EP 3034 DI 10.1029/98GL00466 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900069 ER PT J AU Musman, S Mader, G Dutton, CE AF Musman, S Mader, G Dutton, CE TI Total electron content changes in the ionosphere during the January 10, 1997 disturbance SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We have used the CORS network of GPS receivers to record ionospheric TEC changes in the continental United States caused by the well observed geomagnetic disturbance of January 10, 1997. This event produced numerous worldwide consequences. Although the initial arrival of this disturbance was before sunrise in the U.S. the TEC levels were most significantly altered later during the daylight hours. We display temporal and spatial changes through time series at selected sites and maps of the entire network. The usual sequence of diurnal changes was not greatly altered, but most of the TEC values were increased by about a factor of one and a half to two. Stations in the northeast and upper north central were exceptions and showed a small decrease in TEC. We interpret the TEC changes as consequences of changes in neutral chemical composition resulting from storm heating. C1 NOAA, Geosci Res Div, Silver Spring, MD 20910 USA. RP Musman, S (reprint author), NOAA, Geosci Res Div, 1315 E West Highway, Silver Spring, MD 20910 USA. NR 7 TC 12 Z9 12 U1 2 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1998 VL 25 IS 15 BP 3055 EP 3058 DI 10.1029/98GL51785 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 108WZ UT WOS:000075289900075 ER PT J AU Cline, D Elder, K Bales, R AF Cline, D Elder, K Bales, R TI Scale effects in a distributed snow water equivalence and snowmelt model for mountain basins SO HYDROLOGICAL PROCESSES LA English DT Article DE scale effects; snow water equivalence; mountain basins; SNODIS; spatial and temporal resolution ID RADIATION AB We investigated the effect of increasing spatial and temporal resolutions on modelled distributions of snow water equivalence (SWE) and snowmelt in the Emerald Lake Watershed (ELW) of the Sierra Nevada of California, USA. We used a coupled remote sensing/distributed energy balance snowmelt model (SNODIS), and used previously validated results from a high spatial (30 m) and temporal (hourly) resolution model run in ELW as a control. We selected spatial resolutions that are commensurate with standard product DEMs (digital elevation models) or with existing or planned satellite remote sensing data, and temporal resolutions that are factors of typical operational intervals for meteorological data, We degraded the spatial resolution of the DEM from 30 m to 90, 250 and 500 m prior to computing the distributed micrometeorological data. We degraded the classified remote sensing data to the same spatial resolutions prior to computing the duration of the snow cover. Similarly, we degraded the temporal resolution of the micrometeorological data from I h to 3 and 6 h prior to computing the distributed energy balance and snowmelt. We compared mean basin SWE, basin snowpack water volume and the spatial patterns of SWE from each test with our previous, high resolution results. We found no significant differences between the mean basin-wide SWE computed from the 250 m and 500 m spatial resolutions and that of our high resolution control, regardless of temporal resolution. At each temporal resolution mean basin SWE was overestimated at the 90 m resolution by 14-17%, Coarsening of the spatial resolution did result in a loss of explicit information regarding the location of SWE in the basin, as expected. We discuss these results in terms of their implications for applying the SNODIS model to larger regions. (C) 1998 John Wiley & Sons, Ltd. C1 NOAA, Natl Operat Hydrol Remote Sensing Ctr, Off Hydrol, Natl Weather Serv, Silver Spring, MD 20910 USA. RP Cline, D (reprint author), NOAA, Natl Operat Hydrol Remote Sensing Ctr, Off Hydrol, Natl Weather Serv, Silver Spring, MD 20910 USA. NR 11 TC 36 Z9 38 U1 1 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD AUG-SEP PY 1998 VL 12 IS 10-11 BP 1527 EP 1536 DI 10.1002/(SICI)1099-1085(199808/09)12:10/11<1527::AID-HYP678>3.0.CO;2-E PG 10 WC Water Resources SC Water Resources GA 116TF UT WOS:000075740100002 ER PT J AU Ramsay, BH AF Ramsay, BH TI The interactive multisensor snow and ice mapping system SO HYDROLOGICAL PROCESSES LA English DT Article DE satellite remote sensing; environmental data; snow and ice cover; geographic information system; climate ID SSM/I MEASUREMENTS; COVER AB The interactive multisensor snow and ice mapping system (IMS) was developed to give snow and ice analysts the tools, on one platform, to inspect visually the imagery and mapped data from various sensor sources to determine the presence of snow and ice and to depict snow- and ice-covered areas on a map on a daily basis, in one hour or less. Snow and ice analysts in the National Environmental Satellite, Data, and Information Service have been creating weekly maps showing the extent of snow cover for the Northern Hemisphere since 1966 using visible imagery from polar-orbiting and geostationary satellites and surface observations as data sources. The current process is mostly manual and time-consuming, taking up to 10 hours to produce a map during the snow season. Where cloud cover precludes an unobstructed view of an area during the entire week, the analysis from the previous week is carried forward. Each week the analyst draws a new map by hand, then digitizes the extent of snow and ice cover using an 89 x 89 line grid overlaid on a stereographic map of the Northern Hemisphere. The hand-drawn map is photocopied and distributed and the digitized map is saved to a file for use in National Weather Service numerical models and for archival storage. IMS was designed and built to replace and improve this process by producing a more accurate and timely product. (C) 1998 John Wiley & Sons, Ltd. C1 NOAA, NESDIS, ESP22, Ctr Sci, Camp Springs, MD 20746 USA. RP Ramsay, BH (reprint author), NOAA, NESDIS, ESP22, Ctr Sci, Room 510,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 22 TC 153 Z9 159 U1 0 U2 25 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD AUG-SEP PY 1998 VL 12 IS 10-11 BP 1537 EP 1546 DI 10.1002/(SICI)1099-1085(199808/09)12:10/11<1537::AID-HYP679>3.0.CO;2-A PG 10 WC Water Resources SC Water Resources GA 116TF UT WOS:000075740100003 ER PT J AU Sherman, K Solow, A Jossi, J Kane, J AF Sherman, K Solow, A Jossi, J Kane, J TI Biodiversity and abundance of the zooplankton of the Northeast Shelf ecosystem SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES Symposium on Temporal Variability of Plankton and Their Physico-Chemical Environment CY MAR 19-21, 1997 CL KIEL, GERMANY SP Int Council Explorat Sea DE abundance; biodiversity; Northeast Shelf USA; zooplankton ID CALIFORNIA CURRENT; ATLANTIC; ECOLOGY; TRENDS AB Since 1961, the Northeast Fisheries Science Center of the National Marine Fisheries Service has been conducting a study of the zooplankton of the US Northeast Shelf ecosystem. One of the objectives is to investigate ecological patterns of the system for any evidence of regime shifts and their effects on biodiversity and abundance of zooplankton and fish stocks. Two sampling strategies have been used: collections with Continuous Plankton Recorders beginning in 1961; and collections with bongo nets during the decade of MARMAP surveys (1977-1987), augmented by a time series of collections made during the autumn and spring groundfish surveys (1977-1993). The climate regime of the region leads to distinct and recurring seasonal pulses in zooplankton biomass and species succession in each of the four subareas of the shelf ecosystem distinguished. Evidence was detected in the analyses of inter-annual variability in species abundance and zooplankton biomass. However, no evidence of a large-scale regime shift of the magnitude described recently for other areas was detected From our analyses. Species shifts in abundance and the inter-annual and decadal variability observed in zooplankton biomass levels have allowed for sufficient residual sustainability in zooplankton biodiversity and abundance to support the recovery of depleted pelagic fish stocks. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett Lab, Narragansett, RI 02882 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP Sherman, K (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett Lab, 28 Tarzwell Dr, Narragansett, RI 02882 USA. NR 15 TC 19 Z9 20 U1 0 U2 7 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD AUG PY 1998 VL 55 IS 4 BP 730 EP 738 DI 10.1006/jmsc.1998.0377 PG 9 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 134QN UT WOS:000076754200020 ER PT J AU Baker-Jarvis, J Geyer, RG Grosvenor, JH Janezic, MD Jones, CA Riddle, B Weil, CM Krupka, J AF Baker-Jarvis, J Geyer, RG Grosvenor, JH Janezic, MD Jones, CA Riddle, B Weil, CM Krupka, J TI Dielectric characterization of low-loss materials - A comparison of techniques SO IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION LA English DT Article ID RESONATORS; MICROWAVE; MODES; FREQUENCIES; GHZ AB Measurements on low-loss materials using closed and open cavity resonators, and dielectric resonator methods are presented. Results indicate that consistent measurement results can be obtained with a number of well-characterized fixtures. Uncertainties associated with each method are addressed. Measurements also were performed an materials used in previous intercomparisons. C1 Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80303 USA. Warsaw Univ Technol, PL-00661 Warsaw, Poland. RP Baker-Jarvis, J (reprint author), Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80303 USA. NR 42 TC 94 Z9 94 U1 2 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1070-9878 EI 1558-4135 J9 IEEE T DIELECT EL IN JI IEEE Trns. Dielectr. Electr. Insul. PD AUG PY 1998 VL 5 IS 4 BP 571 EP 577 DI 10.1109/94.708274 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 117AY UT WOS:000075758600014 ER PT J AU Hill, DA AF Hill, DA TI Plane wave integral representation for fields in reverberation chambers SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE dipole antenna; electric field; loop antenna; magnetic field; mode-stirred chamber; radiated immunity; reverberation chamber; statistical electromagnetics ID MODE-STIRRED CHAMBER AB A plane wave integral representation is presented for well-stirred fields in a reverberation chamber, The representation automatically satisfies Maxwell's equations in a source-free region and the statistical properties of the fields are introduced through the angular spectrum, which is taken to be a random variable, Starting with fairly simple and physically appropriate assumptions for the angular spectrum, a number of properties of the electric and magnetic fields and the power received by an antenna or a test object are derived. Many of these properties and test object responses are in agreement with other theories or with measured results. An important result for radiated immunity testing is that the ensemble (stirring) average of received power is equal to the average over plane wave incidence and polarization. C1 Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80303 USA. RP Hill, DA (reprint author), Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80303 USA. NR 26 TC 262 Z9 276 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 1998 VL 40 IS 3 BP 209 EP 217 DI 10.1109/15.709418 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 112PT UT WOS:000075503700004 ER PT J AU Kawalko, SF Kanda, M AF Kawalko, SF Kanda, M TI Comments on "Near-zone gain of open-ended rectangular waveguides" - Reply SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Letter DE near-zone gain; open-ended waveguides C1 Natl Inst Stand & Technol, Div Electromagnet Fields, Dept Commerce, Boulder, CO 80303 USA. RP Kawalko, SF (reprint author), Natl Inst Stand & Technol, Div Electromagnet Fields, Dept Commerce, Boulder, CO 80303 USA. NR 6 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 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 1998 VL 40 IS 3 BP 295 EP 295 DI 10.1109/TEMC.1998.709431 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 112PT UT WOS:000075503700017 ER PT J AU Garris, MD Wilson, CL Blue, JL AF Garris, MD Wilson, CL Blue, JL TI Neural network-based systems for handprint OCR applications SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE Boltzmann weight pruning; handprint; multilayer perceptron; neural networks; optical character recognition; public domain ID CHARACTER-RECOGNITION; FEATURE-EXTRACTION AB Over the last five years or so, neural network (NN)based approaches have been steadily gaining performance and popularity for a wide range of optical character recognition (OCR) problems, from isolated digit recognition to handprint recognition. In this paper, we present an NN classification scheme based on an enhanced multilayer perceptron (MLP) and describe an end-to-end system for form-based handprint OCR applications designed by the National Institute of Standards and Technology (NIST) Visual Image Processing Group. The enhancements to the MLP are based on i) neuron activations functions that reduce the occurrences of singular Jacobians; ii) successive regularization to constrain the volume of the weight space; and iii) Boltzmann pruning to constrain the dimension of the weight space. Performance characterization studies of NN systems evaluated at the first OCR systems conference and the NIST form-based handprint recognition system are also summarized. C1 NIST, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Garris, MD (reprint author), NIST, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 64 TC 24 Z9 25 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD AUG PY 1998 VL 7 IS 8 BP 1097 EP 1112 DI 10.1109/83.704304 PG 16 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 101KN UT WOS:000074868300002 PM 18276327 ER PT J AU Phillips, PJ AF Phillips, PJ TI Matching pursuit filters applied to face identification SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE face recognition; projection pursuit; wavelets ID PROJECTION PURSUIT; NEURAL NETWORKS; RECOGNITION; ARCHITECTURE AB We present a face identification algorithm that automatically processes are unknown image by locating and identifying the face. The heart of the algorithm is the use of pursuit Biters. A matching pursuit Biter is an adapted wavelet expansion, where the expansion is adapted to both the data and the pattern recognition problem being addressed. For identification, the filters find the features that differentiate among faces, whereas, for detection, the Biters encode the similarities among bees, The Biters are designed though a simultaneous decomposition a of training set into a two-dimensional (2-D) wavelet expansion. This yields a representation that is explicitly 2-D and encodes information locally. The algorithm uses coarse to fine processing to locate a small set of key facial features, which are restricted to the nose and eye regions of the face, The result is an algorithm that is robust to variations in facial expression, hair style, and the surrounding environment. Based on the locations of the facial features, the identification module searches the data base for the identity of the unknown face using matching pursuit filters to make the identification. The algorithm was demonstrated oil three sets of images, The first set was images from the FERET data base. The second set was infrared and visible images of the same people. This demonstration was done to compare performance on infrared and visible images individually, and on fusing the results from both modalities. The third set was mugshot data from a law enforcement application. C1 USA, Res Lab, Washington, DC 20310 USA. RP Phillips, PJ (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 37 TC 79 Z9 81 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD AUG PY 1998 VL 7 IS 8 BP 1150 EP 1164 DI 10.1109/83.704308 PG 15 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 101KN UT WOS:000074868300006 PM 18276331 ER PT J AU Harvey, AH AF Harvey, AH TI Applications of near-critical dilute-solution thermodynamics SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SUPERCRITICAL FLUID CHROMATOGRAPHY; PARTIAL MOLAR VOLUMES; CRITICAL-POINT; CRITICAL-BEHAVIOR; AQUEOUS-SOLUTIONS; HENRYS CONSTANTS; PHASE-EQUILIBRIA; NONPOLAR GASES; CARBON-DIOXIDE; SOLUBILITY AB Much of the thermodynamics of dilute solutions near the solvent's critical point is governed by a single thermodynamic derivative known as the Krichevskii parameter. This parameter manifests itself in some linear asymptotic relationships that describe the behavior of solute Henry's constants and Infinite-dilution K-factors in the vicinity of the solvent's critical point. This paper reviews the application of these asymptotic relationships to practical thermodynamic calculations. Successful correlations have been produced for Henry's constants and K-factors. Application to apparent molar properties is discussed, and an explanation is given for its quantitative inadequacy. The Henry's constant relationship has been extended to describe the solubility of solids in supercritical fluids; current limitations and future prospects are discussed for this application. Finally, a new linear relationship is derived for the capacity factor in supercritical fluid chromatography and applied to some data from the literature. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Harvey, AH (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. EM aharvey@boulder.nist.gov NR 35 TC 27 Z9 27 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD AUG PY 1998 VL 37 IS 8 BP 3080 EP 3088 DI 10.1021/ie970800r PG 9 WC Engineering, Chemical SC Engineering GA 107MU UT WOS:000075213700023 ER PT J AU Burkholder, JB AF Burkholder, JB TI Rate coefficient for the reaction: Br+Br2O -> Br-2+BrO SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID VISIBLE ABSORPTION-SPECTRA; BR2O; PHOTOLYSIS; HOBR; BR-2 AB The room temperature rate coefficient for the reaction Br + Br2O --> Br-2 + BrO (3) has been measured using the technique of pulse-laser photolysis with long-path transient absorption detection of the BrO reaction product. A value of k(3) = (2.0 +/- 0.5) x 10(-10) cm(3) molecule(-1) s(-1) was determined. The photolysis products of Br2O at 308 nm were also examined. (C) 1998 John Wiley & Sons. Inc. Int J Chem Kinet 30: 571-576. 1998. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Burkholder, JB (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Burkholder, James/H-4914-2013 NR 14 TC 5 Z9 5 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD AUG PY 1998 VL 30 IS 8 BP 571 EP 576 DI 10.1002/(SICI)1097-4601(1998)30:8<571::AID-KIN6>3.0.CO;2-P PG 6 WC Chemistry, Physical SC Chemistry GA 101LU UT WOS:000074871100006 ER PT J AU Newsom, RK Bruce, CW AF Newsom, RK Bruce, CW TI Orientational properties of fibrous aerosols in atmospheric turbulence SO JOURNAL OF AEROSOL SCIENCE LA English DT Article ID LONG SLENDER BODIES; CROSS-SECTION; VISCOUS-FLUID; PARTICLES; FLOW; MOTION; ABSORPTION; FIELD AB Experimental and computational results of the orientational properties of relatively large fibrous aerosols dispersed in the turbulent atmospheric boundary layer are presented. The mean orientation of the fibers is compared with independent measurements of the variance in the strain rate held, [E-ij(2)], associated with the turbulent air motion. Millimeter wave depolarization measurements were used to obtain ensemble average orientation of the dispersed fibers. A spectral analysis of data obtained from nearly collocated and simultaneous high-frequency hot wire probe measurements was employed to estimate [E-ij(2)]. A distinctive correlation is found between decreasing(E) and increasing horizontal orientation of the fibers. For a given [E-ij(2)] significantly different levels of horizontal orientation are observed depending on the fiber length and diameter A simple model of the motion of a straight rigid fiber in a turbulent viscous medium is presented. This model qualitatively describes the relationship between fiber geometry and relative mean orientation; However, it consistently over estimates the observed mean orientation. Discrepancies may be due to either deficiencies in the model, the quality of the dispersed fibers, or both. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 New Mexico State Univ, Las Cruces, NM 88003 USA. RP Newsom, RK (reprint author), NOAA, ERL, Environm Technol Lab REET2, 325 Broadway, Boulder, CO 80303 USA. NR 26 TC 18 Z9 18 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD AUG PY 1998 VL 29 IS 7 BP 773 EP 797 DI 10.1016/S0021-8502(97)10030-1 PG 25 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZU008 UT WOS:000074152000002 ER PT J AU Shima, M Salamanca-Riba, L Moffat, TP McMichael, RD Swartzendruber, LJ AF Shima, M Salamanca-Riba, L Moffat, TP McMichael, RD Swartzendruber, LJ TI Structural and magnetic fourfold symmetry of Co/Cu multilayers electrodeposited on Si(001) substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GIANT MAGNETORESISTANCE AB We have observed in-plane fourfold symmetry of the magnetization and magnetoresistance in Co/Cu multilayers electrodeposited on Si(001) substrates covered with a thin evaporated Cu seed layer. The fourfold symmetry correlates with the in-plane crystalline structure of the multilayers. High-angle x-ray diffraction shows that the Co/Cu multilayers have a strong (001) texture. Phi-scan x-ray diffraction reveals that the multilayers have fourfold symmetry in the plane with a 45 degrees rotation with respect to the Si substrates. We estimated an anisotropy field of 98 mT from vector magnetization curves, which is in fairly good agreement with the value obtained from Co/Cu multilayers electrodeposited on (001) Cu single crystal substrates. The giant magnetoresistance appears to depend on the in-plane orientation of the multilayer due to the magnetocrystalline anisotropy. (C) 1998 American Institute of Physics. [S0021-8979(98)00415-0]. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NIST, Gaithersburg, MD 20899 USA. RP Shima, M (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI McMichael, Robert/J-8688-2012; Salamanca-Riba, Lourdes/B-3785-2009; OI Salamanca-Riba, Lourdes/0000-0001-8155-6403; McMichael, Robert/0000-0002-1372-664X NR 11 TC 24 Z9 24 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1998 VL 84 IS 3 BP 1504 EP 1507 DI 10.1063/1.368254 PG 4 WC Physics, Applied SC Physics GA 108YT UT WOS:000075294600058 ER PT J AU Walton, SG Champion, RL Wang, YC AF Walton, SG Champion, RL Wang, YC TI Negative ion emission from a stainless steel surface due to positive ion collisions SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID WORK-FUNCTION DEPENDENCE; DISCHARGE; ELECTRON AB Absolute yields of negative ions and secondary electrons resulting from positive ions impacting a stainless steel surface have been determined as a function of the impact energy. The surface conditions range from those commonly found in situ for discharge electrodes to a surface free of any adsorbate. The implications of these findings to discharge modeling are discussed. (C) 1998 American Institute of Physics. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Walton, SG (reprint author), Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NR 10 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1998 VL 84 IS 3 BP 1706 EP 1707 DI 10.1063/1.368241 PG 2 WC Physics, Applied SC Physics GA 108YT UT WOS:000075294600087 ER PT J AU Zhang, NF AF Zhang, NF TI Estimating process capability indexes for autocorrelated data SO JOURNAL OF APPLIED STATISTICS LA English DT Article AB Process capability indexes are widely used in the manufacturing industries and by supplier companies in process assessments and in the evaluation of purchasing decisions. One concern about using the process capability indexes is the assumption of the mutual independence of the process data, because, in process industries, process data are often autocorrelated. This paper discusses the use of the process capability indexes C-p and C-pk when the process data are autocorrelated. Interval estimation procedures for C-p and C-pk are proposed and their properties are studied. C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 8 TC 29 Z9 34 U1 0 U2 2 PU CARFAX PUBL CO PI ABINGDON PA PO BOX 25, ABINGDON, OXFORDSHIRE, ENGLAND OX14 3UE SN 0266-4763 J9 J APPL STAT JI J. Appl. Stat. PD AUG PY 1998 VL 25 IS 4 BP 559 EP 574 DI 10.1080/02664769823025 PG 16 WC Statistics & Probability SC Mathematics GA 123BP UT WOS:000076106200009 ER PT J AU Bodhaine, BA Dutton, EG McKenzie, RL Johnston, PV AF Bodhaine, BA Dutton, EG McKenzie, RL Johnston, PV TI Calibrating broadband UV instruments: Ozone and solar zenith angle dependence SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MAUNA-LOA; ULTRAVIOLET-RADIATION; METER AB A UV spectroradiometer was installed at Mauna Loa Observatory (MLO), Hawaii, in July 1995. This instrument has been employed to characterize several broadband UV instruments of a type commonly used to estimate erythemal irradiance at many sites around the globe. One year of clear-sky data from MLO has been analyzed for solar zenith angles (SZAs) of 5 degrees-85 degrees, in steps of 5 degrees, and for total ozone values in the range 220-310 DU measured with a Dobson spectrophotometer. Because the spectral responses of various broadband instruments can be quite different, and particularly because the erythemal response defined for human skin is significantly different than that of many broadband instruments, the calibration of a broadband instrument reporting in erythemal units is strongly dependent on total ozone and SZA. When a broadband instrument is placed in the field it is necessary to know the calibration as a function of ozone and SZA to determine accurate erythemal irradiance. However, the manufacturers of broadband instruments do not generally provide information on the ozone dependence of the calibration. A procedure is described here for determining the calibration of a broadband UV instrument by comparison with a calibrated spectroradiometer. This procedure does not require precise knowledge of the spectral response of the broadband instrument. This analysis shows that if, for example, total ozone concentration decreased from 300 to 200 DU, the calibration constant of a broadband instrument should be increased by almost 20%. Therefore, the broadband instrument would significantly underestimate the increase of erythema. C1 NOAA, CDML, Boulder, CO 80303 USA. Natl Inst Water & Atmospher Res, Lauder, New Zealand. RP Bodhaine, BA (reprint author), NOAA, CDML, R-E-CG1,325 Broadway, Boulder, CO 80303 USA. NR 27 TC 29 Z9 30 U1 0 U2 1 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 AUG PY 1998 VL 15 IS 4 BP 916 EP 926 DI 10.1175/1520-0426(1998)015<0916:CBUIOA>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 107WK UT WOS:000075233800006 ER PT J AU Johnson, BC Shaw, PS Hooker, SB Lynch, D AF Johnson, BC Shaw, PS Hooker, SB Lynch, D TI Radiometric and engineering performance of the SeaWiFS Quality Monitor (SQM): A portable light source for field radiometers SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID STANDARD LAMPS AB A portable and stable source of radiant flux, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Quality Monitor (SQM), was developed as a field instrument for use in experiments away from the calibration laboratory such as those encountered during oceanographic cruises. The SQM monitors the radiometric stability of radiance and irradiance sensors during these field experiments; a companion paper gives results acquired during the third Atlantic Meridional Transect cruise. In conjunction with laboratory calibration sources, the SQM can be used to transfer the calibration to the field experiment. Two independent lamp assemblies generate three flux levels, and me lamps are operated at constant current using active control. The exit aperture of the SQM is large and homogeneous in radiance. The SQM was designed to approximate a Lambertian radiator. An internal heater provides operational stability and decreased warmup intervals, which minimizes lamp hours. Temperature-controlled silicon photodiodes with colored-glass filters monitor the stability of the SQM, which is better than 1%. These independent monitors, which are integrated with the SQM, provide information on the Aux from the SQM and can be used to normalize the output from the field radiometers during the experiment. Three reference devices, or fiducials, which are designed to mimic the optical surfaces of the held radiometers but are not functioning detector units, are used in place of the field radiometers to produce baseline monitor signals. The front surface of the fiducial is protected when not in use and kept clean during the field experiment. The monitor signals acquired using the fiducials provide additional information on the radiometric stability of the SQM. A kinematically designed mounting ring is used on both the field radiometers and the fiducials to ensure the devices being tested view the same part of the exit aperture each time they are used. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Reyer Corp, New Market, MD USA. RP Johnson, BC (reprint author), NIST, Opt Technol Div, Bldg 221,Rm B208, Gaithersburg, MD 20899 USA. RI Hooker, Stanford/E-2162-2012 NR 12 TC 11 Z9 11 U1 0 U2 1 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 AUG PY 1998 VL 15 IS 4 BP 1008 EP 1022 DI 10.1175/1520-0426(1998)015<1008:RAEPOT>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 107WK UT WOS:000075233800013 ER PT J AU Hansel, A Glantschnig, M Scheiring, C Lindinger, W Ferguson, EE AF Hansel, A Glantschnig, M Scheiring, C Lindinger, W Ferguson, EE TI Energy dependence of the isomerization of HCN+ to HNC+ via ion molecule reactions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLOW-DRIFT TECHNIQUE; CHEMISTRY; MOBILITY; STATES; N-2+; HE AB The mechanism for isomerization of HCN+ ions to the more stable HNC+ in collision with CO2 at thermal energy has been confirmed to be a double proton transfer in the collision complex. First a proton is transferred from C in HCN+, then, following CN rotation in the complex, the proton is transferred to the N atom, both proton transfers being exothermic. The mechanism has been established by measuring the reaction of HCN+ with CO2 as a function of energy from thermal up to 0.7 eV relative kinetic energy in a selected ion flow drift tube. The isomers are distinguished by the use of monitors that react differently with the two isomers. A similar HCN+ to HNC+ isomerization occurs in thermal collisions with CO. (C) 1998 American Institute of Physics. C1 Univ Innsbruck, Inst Ionenphys, A-6020 Innsbruck, Austria. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Univ Innsbruck, Inst Ionenphys, Tech Str 25, A-6020 Innsbruck, Austria. EM armin.hansel@uibk.ac.at RI Hansel, Armin/F-3915-2010 OI Hansel, Armin/0000-0002-1062-2394 NR 22 TC 13 Z9 13 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1998 VL 109 IS 5 BP 1743 EP 1747 DI 10.1063/1.476748 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 105HH UT WOS:000075066300020 ER PT J AU Hansel, A Scheiring, C Glantschnig, M Lindinger, W Ferguson, EE AF Hansel, A Scheiring, C Glantschnig, M Lindinger, W Ferguson, EE TI Thermochemistry of HNC, HNC+, and CF3+ SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ENERGY; STATES; HCN+ AB In the course of mechanistic studies on HCN+ isomerization in reaction with CO and CO2, we have fortuitously determined the heats of formation of HNC and HNC+ with good precision. The uncertainty is the uncertainty in the heat of formation of HCN, +/- 1 kcal mol(-1). This appears to be the first precise experimental determination of these energies. Several prior theoretical calculations have produced reasonable energy values. We also observed the reaction of HCN+ with CF4 to be slightly endothermic, which allows the determination of an upper limit on the threshold energy for CF4 --> CF3+ + F of 14.28 eV, in excellent agreement with several prior determinations but in sharp disagreement with the most recent determination. (C) 1998 American Institute of Physics. C1 Univ Innsbruck, Inst Ionenphys, A-6020 Innsbruck, Austria. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Univ Innsbruck, Inst Ionenphys, Tech Str 25, A-6020 Innsbruck, Austria. EM armin.hansel@uibk.ac.at RI Hansel, Armin/F-3915-2010 OI Hansel, Armin/0000-0002-1062-2394 NR 20 TC 39 Z9 39 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1998 VL 109 IS 5 BP 1748 EP 1750 DI 10.1063/1.476749 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 105HH UT WOS:000075066300021 ER PT J AU Lopez, RE Holle, RL AF Lopez, RE Holle, RL TI Changes in the number of lightning deaths in the United States during the twentieth century SO JOURNAL OF CLIMATE LA English DT Article ID INJURIES AB Long-term changes in the number of lightning deaths from 1900 to 1991 have been examined for the contiguous United States. The population-normalized series revealed an exponential decrease in the number of deaths per million people. This exponential trend is also present in the decrease of the rural U.S. population for the period. The two datasets agree remarkably well and this suggests the downward trend in lightning deaths resulted to a large extent from the reduction of the rural population. Superimposed on the overall downward trend in lightning deaths were fluctuations of two or three decades in duration. The patterns of these fluctuations are paralleled by nationwide changes in thunder-day frequencies and average surface temperature values. Thus, it appears that the lightning death fluctuations are climatically induced. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Lopez, RE (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 16 TC 32 Z9 35 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1998 VL 11 IS 8 BP 2070 EP 2077 DI 10.1175/1520-0442-11.8.2070 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 111CT UT WOS:000075420300014 ER PT J AU Noel, J Changnon, D AF Noel, J Changnon, D TI A pilot study examining US winter cyclone frequency patterns associated with three ENSO parameters SO JOURNAL OF CLIMATE LA English DT Article ID NINO SOUTHERN OSCILLATION; SEA-SURFACE TEMPERATURE; EL-NINO; PRECIPITATION; PACIFIC; CLIMATE AB Teleconnections were used to link three El Nino-Southern Oscillation (ENSO) parameters to winter (December-February) cyclone frequencies over the United States during the 1949-96 period. Since each ENSO event is not exactly the same, small subsets of ENSO events were examined in addition to the more common composite ENSO event. Mean winter cyclone frequencies, derived by counting cyclones passing through 30, 5 degrees latitude equal-area circles located in a grid from 70 degrees to 120 degrees W and 30 degrees to 50 degrees N were determined for classes of El Ninos and La Ninas based on 1) the intensity of the equatorial Pacific sea surface temperature anomaly, 2) the intensity of the Tahiti-Darwin sea level pressure anomaly, and 3) the location of the 28 degrees C isotherm. The average cyclone count for each class of El Nino and La Nina was compared to the average count for winters when no ENSO event occurred. Expected differences in cyclone frequency patterns when comparing an average of all El Nino winters to all La Nina winters were found; however, large pattern differences were also determined when comparing winters with strong El Ninos to moderate-weak El Ninos and similarly for La Ninas. Significant differences in number of cyclones were found in 8 of 30 circles located in the Pacific Northwest, the Great Lakes, New England, and the Southeast. The differences found in the cyclone frequency patterns for El Ninos and La Ninas of different intensities and locations indicated that using a composite of air El Ninos or La Ninas may provide misleading information while examination of each of these parameters independently may assist in the preparation of long-range climate predictions. C1 NOAA, Natl Weather Serv, Ohio River Forecast Ctr, Wilmington, OH 45177 USA. No Illinois Univ, Dept Geog, De Kalb, IL 60115 USA. RP Noel, J (reprint author), NOAA, Natl Weather Serv, Ohio River Forecast Ctr, 1901 S State Route 134, Wilmington, OH 45177 USA. NR 27 TC 24 Z9 25 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1998 VL 11 IS 8 BP 2152 EP 2159 DI 10.1175/1520-0442-11.8.2152 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 111CT UT WOS:000075420300021 ER PT J AU Lowe, TE Brill, RW Cousins, KL AF Lowe, TE Brill, RW Cousins, KL TI Responses of the red blood cells from two high-energy-demand teleosts, yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis), to catecholamines SO JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY LA English DT Article DE adrenaline; noradrenaline; Na+/H+ antiporter; oxygen; RBC ID TROUT SALMO-GAIRDNERI; ACID-BASE REGULATION; FLOUNDER PLATICHTHYS-STELLATUS; HEMOGLOBIN-OXYGEN-AFFINITY; CARBON-DIOXIDE TRANSPORT; ACUTE TEMPERATURE-CHANGE; CARP CYPRINUS-CARPIO; RAINBOW-TROUT; ONCORHYNCHUS-MYKISS; ADRENERGIC RESPONSES AB In fishes, catecholamines increase red blood cell intracellular pH through stimulation of a sodium/proton (Na+/H+) antiporter. This response can counteract potential reductions in blood O-2 carrying capacity (due to Bohr and Root effects) when plasma pH and intracellular pH decrease during hypoxia, hypercapnia, or following exhaustive exercise. Tuna physiology and behavior dictate exceptionally high rates of O-2 delivery to the tissues often under adverse conditions, but especially during recovery from exhaustive exercise when plasma pH may be reduced by as much as 0.4 pH units. We hypothesize that blood O-2 transport during periods of metabolic acidosis could be especially critical in tunas and the response of rbc to catecholamines elevated to an extreme. We therefore investigated the in vitro response of red blood cells from yellowfin tuna (Thunnus albacares es) and skipjack tuna (Katsuwonus pelamis) to catecholamines. Tuna red blood cells had a typical response to catecholamines, indicated by a rapid decrease in plasma pH. Amiloride reduced the response, whereas 4,4'diisothiocyanatostilbene-2,2'-disulphonic acid enhanced both the decrease in plasma pH and the increase in intracellular pH. Changes in plasma [Na+], [Cl-], and [K+] were consistent with the hypothesis that tuna red blood cells have a Na+/H+ antiporter similar to that described for other teleost red blood cells. Red blood cells from both tuna species were more responsive to noradrenaline than adrenaline. At identical catecholamine concentrations, the decrease in plasma pH was greater in skipjack tuna blood, the more active of the two tuna species. Based on changes in plasma pH, the response of red blood cells to catecholamines from both tuna species was less than that of rainbow trout (Oncorhynchus mykiss) red blood cells, but greater than that of cod (Gadus morhua) red blood cells. Noradrenaline had no measurable influence on the O-2 affinity of skipjack tuna blood and only slightly increased the O-2 affinity of yellowfin tuna blood. Our results, therefore, do not support our original hypothesis. The catecholamine response of red blood cells from high-energy-demand teleosts (i.e., tunas) is not enhanced compared to other teleosts. There are data on changes in cardio-respiratory function in tunas caused by acute hypoxia and modest increases in activity, but there are no data on the changes in cardio-respiratory function in tunas accompanying the large increases in metabolic rate seen during recovery from exhaustive exercise. However, we conclude that during those instances where high rates of O-2 delivery to the tissues are needed, tunas' ability to increase cardiac output, ventilation volume, blood O-2 carrying capacity, and effective. respiratory (i.e., gill) surface area are probably more important than are the responses of red blood cells to catecholamines. We also use our data to investigate the extent of the Haldane effect and its relationship to blood O-2 and CO2 transport in yellowfin tuna. Yellowfin tuna blood shows a large Haldane effect; intracellular pH increases 0.20 units during oxygenation. The largest change in intracellular pH occurs between 40-100% O-2 saturation, indicating that yellowfin tuna, like other teleosts, fully exploit the Haldane effect over the normal physiological range of blood O-2 saturation. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Joint Inst Marine & Atmospher Res, Pelag Fisheries Res Program, Honolulu, HI 96822 USA. RP Brill, RW (reprint author), NMFS, 2570 Dole St, Honolulu, HI 96822 USA. EM rbrill@honlab.nmfs.hawaii.edu NR 100 TC 24 Z9 25 U1 1 U2 7 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 0174-1578 J9 J COMP PHYSIOL B JI J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol. PD AUG PY 1998 VL 168 IS 6 BP 405 EP 418 DI 10.1007/s003600050160 PG 14 WC Physiology; Zoology SC Physiology; Zoology GA 118HW UT WOS:000075833300001 PM 9747521 ER PT J AU Hassanzedeh, P Irikura, KK AF Hassanzedeh, P Irikura, KK TI Inexpensive vibrational anharmonicities from estimated derivatives: Diatomic molecules SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article DE ab initio; anharmonicity; force field; Morse potential; vibrational frequency ID QUARTIC FORCE-FIELD; LARGE BASIS-SETS; AB-INITIO; BERYLLIUM DIMER; MOLLER-PLESSET; FREQUENCIES; ENERGY; GEOMETRIES; CONSTANTS; EXCHANGE AB Four alternatives are compared for estimating vibrational anharmonicity constants without explicitly calculating the expensive fourth derivatives of the potential curves. In the first, semiempirical approach, fourth derivatives for 53 diatomic molecules are estimated from ab initio second and third derivatives by using the Morse model potential. Vibrational anharmonicities omega(e)x(e) are then computed from the third and fourth derivatives. The second approach invokes a purely empirical linear correlation between omega(e)x(e) and the harmonic frequencies omega(e). The third and fourth empirical approaches suppose that the effective harmonic and anharmonic force constants are proportional (with an additive constant in the fourth approach). Experimental values for omega(e)x(e) are compared with empirical predictions and with semiempirical estimates based upon Hartree-Fock (I-IF), Moller-Plesset (MP2), and local, nonlocal, and hybrid density-functional theories (DFT), using the small 6-31G* basis set. Ab initio values of omega(e) and bond lengths r(e) are also compared against experiment. The (U)MP2 results are the worst and include several anomalies. The other semiempirical methods yield results of comparable accuracy for omega(e)x(e) of hydrides, although the DFT methods are markedly better for omega(e) and r(e) and for omega(e)x(e) of nonhydrides. The empirical estimates are nearly as good as the semiempirical ones. We conclude that: (1) both empirical and semiempirical approximations are useful for predicting stretching anharmonicity constants omega(e)x(e) to precisions of sigma approximate to 5 cm(-1) for hydrides and sigma approximate to 1.5 cm(-1) for nonhydrides; and (2) MP2 theory is relatively unreliable for such calculations. In addition, we find the following tests to be useful when evaluating the reliability of vibrational constants calculated at the UMP2 level: (a) the calculated values of omega(e), and omega(e)x(e) should not deviate substantially from the empirical relations; (b) harmonic frequencies and intensities calculated at the MP2 level should be smaller than those calculated at the corresponding HF level; (c) a large distance-dependence of the spin contamination, d[S-2]/dR greater than or equal to 0.05 A(-1), suggests that calculated constants are too large. (C) 1998 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. George Washington Univ, Dept Chem, Washington, DC 20052 USA. RP Irikura, KK (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, NIST 221-A111, Gaithersburg, MD 20899 USA. EM karl.irikura@nist.gov RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 37 TC 9 Z9 9 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0192-8651 EI 1096-987X J9 J COMPUT CHEM JI J. Comput. Chem. PD AUG PY 1998 VL 19 IS 11 BP 1315 EP 1324 DI 10.1002/(SICI)1096-987X(199808)19:11<1315::AID-JCC11>3.0.CO;2-K PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 104KC UT WOS:000075012600011 ER PT J AU Messick, GA AF Messick, GA TI Diseases, parasites, and symbionts of blue crabs (Callinectes sapidus) dredged from Chesapeake Bay SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID N-SP; DINOFLAGELLATE INFECTION; CHIONOECETES-BAIRDI; PORTUNUS-PELAGICUS; MORETON BAY; HISTOPATHOLOGY; INFESTATION; MORPHOLOGY; PREVALENCE; AUSTRALIA AB A 3-year histological study of disease prevalence in 057 blue crabs, Callinectes sapidus, dredged from 31 sites within Maryland portions of Chesapeake Bay during autumn and winter revealed the presence of many diverse parasites and symbionts. A large number of crabs exhibited hemocytic infiltration and encapsulation. Parasites and symbionts identified included viruses (Baculo-B and RLV-RhVA), a rickettsia-like microorganism (RLM), an unusual strandlike organism, unidentified microsporidians and gregarines, both parasitic (Mesanophrys chesapeakensis) and symbiotic (Lng enophrys callinectes and Epistylis sp.) cilates, the nemertean Carcinonemertes carcinophila, and trematode metacercariae, some hyperparasitized by the haplosporidian Urosporidium crescens. Significant differences in disease and parasite frequencies were observed among survey periods. The prevalence of some tissue responses and parasites exhibited seasonal patterns of infection and infestation. C1 NOAA, Cooperat Oxford Lab, Natl Marine Fisheries Serv, Oxford, MD 21654 USA. RP Messick, GA (reprint author), NOAA, Cooperat Oxford Lab, Natl Marine Fisheries Serv, 904 S Morris St, Oxford, MD 21654 USA. NR 78 TC 26 Z9 28 U1 0 U2 10 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD AUG PY 1998 VL 18 IS 3 BP 533 EP 548 DI 10.2307/1549418 PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 109VH UT WOS:000075344200013 ER PT J AU Soler, T AF Soler, T TI A compendium of transformation formulas useful in GPS work SO JOURNAL OF GEODESY LA English DT Article DE transformation of frames; effect of plate tectonics on GPS observables active and passive transformations; station velocities ID ROTATION AB In order properly to apply transformations when using data derived from different GPS solutions. the effects of plate motion on the coordinates should be accurately taken into consideration. Only then can a rigorous comparison be established between results observed at different epochs. Equations are given to relate GPS-derived Cartesian coordinates and velocities affected by changes of their reference frames and epochs. C1 NOAA, NOS, Natl Geodet Survey, Silver Spring, MD 20910 USA. RP Soler, T (reprint author), NOAA, NOS, Natl Geodet Survey, N-NGS22,8116,1315 E W Highway, Silver Spring, MD 20910 USA. RI Soler, Tomas/F-6386-2010 NR 24 TC 29 Z9 35 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD AUG PY 1998 VL 72 IS 7-8 BP 482 EP 490 DI 10.1007/s001900050187 PG 9 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 121XF UT WOS:000076040600011 ER PT J AU Lui, ATY Williams, DJ McEntire, RW Ohtani, S Zanetti, LJ Bristow, WA Greenwald, RA Newell, PT Christon, SP Mukai, T Tsuruda, K Yamamoto, T Kokubun, S Matsumoto, H Kojima, H Murata, T Fairfield, DH Lepping, RP Samson, JC Rostoker, G Reeves, GD Rodger, AL Singer, HJ AF Lui, ATY Williams, DJ McEntire, RW Ohtani, S Zanetti, LJ Bristow, WA Greenwald, RA Newell, PT Christon, SP Mukai, T Tsuruda, K Yamamoto, T Kokubun, S Matsumoto, H Kojima, H Murata, T Fairfield, DH Lepping, RP Samson, JC Rostoker, G Reeves, GD Rodger, AL Singer, HJ TI Multipoint study of a substorm on February 9, 1995 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA SHEET; MAGNETOSPHERE; FLOWS; WIND AB An extended interval of strong northward interplanetary magnetic field (IMF) was observed by the Wind spacecraft located at an upstream distance of similar to 193 R-E from February 8-10, 1995, with a brief break of southward IMF from 0200 to 0400 UT on February 9. This brief interval of southward IMF led to an isolated substorm of moderate intensity (similar to 500 nT) with expansion phase starting at similar to 0431 UT. This substorm may be triggered by the northward turning of the IMF since its onset time matched well with the time expected for the arrival of the northward turning of the IMF at Earth. The substorm activities were monitored by 11 spacecraft in space (Wind, IMP 8, Geotail, six geosynchronous satellites, one DMSP satellite, and Freja) and two networks of ground stations (Canopus and SuperDARN) covering both the northern and southern hemispheres. The extensive coverage of this event provides us with results (1) showing some unusual characteristics possibly related to the isolated nature of the substorm and (2) revealing some surprising features difficult to reconcile with the traditional substorm model. In the first category is unusually long duration of the growth phase and the long time delay between substorm expansion onset and particle injection onset at the geosynchronous orbit. In the second category is new evidence for multiple particle acceleration sites during substorm expansion and for sunward flow during the late expansion phase of a substorm being unrelated to a single acceleration site (X line) moving from the near-Earth tail to the more distant tail. We also present observations which show the possible optical signature on the ground of bursty bulk flows in the magnetotail. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Maryland, Dept Phys & Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Kanagawa 229, Japan. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. Kyoto Univ, Radio Atmospher Sci Ctr, Kyoto, Japan. Univ Alberta, Dept Phys, Edmonton, AB T6G 2M7, Canada. Los Alamos Natl Lab, Los Alamos, NM USA. British Antarctic Survey, Cambridge CB3 0ET, England. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Reeves, Geoffrey/E-8101-2011; Ohtani, Shinichi/E-3914-2016 OI Reeves, Geoffrey/0000-0002-7985-8098; Ohtani, Shinichi/0000-0002-9565-6840 NR 28 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1998 VL 103 IS A8 BP 17333 EP 17343 DI 10.1029/97JA02632 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107BV UT WOS:000075186700011 ER PT J AU Reeves, GD Friedel, RHW Belian, RD Meier, MM Henderson, MG Onsager, T Singer, HJ Baker, DN Li, X Blake, JB AF Reeves, GD Friedel, RHW Belian, RD Meier, MM Henderson, MG Onsager, T Singer, HJ Baker, DN Li, X Blake, JB TI The relativistic electron response at geosynchronous orbit during the January 1997 magnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB The first geomagnetic storm of 1997 began on January 10. It is of particular interest because it was exceptionally well observed by the full complement of International Solar Terrestrial Physics (ISTP) satellites and because of its possible association with the catastrophic failure of the Telstar 401 telecommunications satellite. Here we report on the energetic electron environment observed by five geosynchronous satellites. In part one of this paper we examine the magnetospheric response to the magnetic cloud. The interval of southward IMF drove strong substorm activity while the interval of northward IMF and high solar wind density strongly compressed the magnetosphere. At energies above a few hundred keV, two distinct electron enhancements were observed at geosynchronous orbit. The first enhancement began and ended suddenly, lasted for approximately 1 day, and is associated with the strong compression of the magnetosphere. The second enhancement showed a more characteristic time delay, peaking on January 15. Both enhancements may be due to transport of electrons from the same initial acceleration event at a location inside geosynchronous orbit but the first enhancement was due to a temporary, quasi-adiabatic transport associated with the compression of the magnetosphere while the second enhancement was due to slower diffusive processes. In the second part of the paper we compare the relativistic electron fluxes measured simultaneously at different local times. We find that the >2-MeV electron fluxes increased first at noon followed by dusk and the? dawn and that there can be difference of two orders of magnitude in the fluxes observed at different local times. Finally, we discuss the development of data-driven models of the relativistic electron belts for space weather applications. By interpolating fluxes between satellites we produced a model that gives the >2-MeV electron fluxes at all local times as a function of universal time. In a first application of this model we show that, at least in this case, magnetopause shadowing does not contribute noticeably to relativistic electron dropouts. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80302 USA. Aerosp Corp, Los Angeles, CA 90009 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Max Planck Inst Aeron, Katlenburg Lindau, Germany. RP Reeves, GD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM reeves@lanl.gov; r.friedel@lanl.gov; rdbelian@lanl.gov; mmeier@lanl.gov; mghenderson@lanl.gov; tonsager@sec.noaa.gov; hsinger@sec.noaa.gov; baker@orion.colorado.edu; lix@kitron.colorado.edu; blake@dirac2.dnet.nasn.gov RI Friedel, Reiner/D-1410-2012; Reeves, Geoffrey/E-8101-2011; Henderson, Michael/A-3948-2011 OI Friedel, Reiner/0000-0002-5228-0281; Reeves, Geoffrey/0000-0002-7985-8098; Henderson, Michael/0000-0003-4975-9029 NR 14 TC 89 Z9 90 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1998 VL 103 IS A8 BP 17559 EP 17570 DI 10.1029/97JA03236 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107BV UT WOS:000075186700030 ER PT J AU Shue, JH Song, P Russell, CT Steinberg, JT Chao, JK Zastenker, G Vaisberg, OL Kokubun, S Singer, HJ Detman, TR Kawano, H AF Shue, JH Song, P Russell, CT Steinberg, JT Chao, JK Zastenker, G Vaisberg, OL Kokubun, S Singer, HJ Detman, TR Kawano, H TI Magnetopause location under extreme solar wind conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; NEAR-EARTH MAGNETOTAIL; SHAPE; SIZE; PRESSURE; MODEL AB During the solar wind dynamic pressure enhancement, around 0200 UT on January 11, 1997, at the end of the January 6-11 magnetic cloud event, the magnetopause was pushed inside geosynchronous orbit. The LANL 1994-084 and GMS 4 geosynchronous satellites crossed the magnetopause and moved into the magnetosheath. Also, the Geotail satellite was in the magnetosheath while the Interball 1 satellite observed magnetopause crossings. This event provides an excellent opportunity to test and validate the prediction capabilities and accuracy of existing models. of the magnetopause location for producing space weather forecasts. In this paper, we compare predictions of two models: the Petrinec and Russell [1996] model and the Shue et al. [1997] model. These two models correctly predict the magnetopause crossings on. the dayside; however, there are some differences in the predictions along the flank. The Shue et al. [1997] model correctly predicts the Geotail magnetopause crossings and partially predicts the Interball 1 crossings. The Petrinec and Russell [1996] model correctly predicts the Interball 1 crossings and is partially consistent with the Geotail observations. We further found that some of the inaccuracy in Shue et al.'s predictions is due to the in appropriate linear extrapolation from the parameter range for average solar wind conditions to that for extreme conditions. To improve predictions under extreme solar wind conditions, we introduce a nonlinear dependence of the parameters oil the solar wind conditions to represent the saturation effects of the solar wind dynamic pressure on the flaring of the magnetopause and saturation effects of the interplanetary magnetic field B-z on the subsolar standoff distance. These changes lead to a better agreement with the Interball 1 observations for this event. C1 Nagoya Univ, Solar Terr Environm Lab, Toyokawa, Aichi 4428507, Japan. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Natl Cent Univ, Inst Space Sci, Chungli 32054, Taiwan. Russian Acad Sci, Space Res Inst, Moscow 117810, Russia. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Shue, JH (reprint author), Nagoya Univ, Solar Terr Environm Lab, Toyokawa, Aichi 4428507, Japan. NR 21 TC 443 Z9 455 U1 3 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1998 VL 103 IS A8 BP 17691 EP 17700 DI 10.1029/98JA01103 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107BV UT WOS:000075186700038 ER PT J AU Coffey, H AF Coffey, H TI Geomagnetic and solar data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article C1 NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80302 USA. RP Coffey, H (reprint author), NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80302 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1998 VL 103 IS A8 BP 17701 EP 17703 DI 10.1029/98JA02029 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107BV UT WOS:000075186700039 ER PT J AU Kamide, Y Baumjohann, W Daglis, IA Gonzalez, WD Grande, M Joselyn, JA McPherron, RL Phillips, JL Reeves, EGD Rostoker, G Sharma, AS Singer, HJ Tsurutani, BT Vasyliunas, VM AF Kamide, Y Baumjohann, W Daglis, IA Gonzalez, WD Grande, M Joselyn, JA McPherron, RL Phillips, JL Reeves, EGD Rostoker, G Sharma, AS Singer, HJ Tsurutani, BT Vasyliunas, VM TI Current understanding of magnetic storms: Storm-substorm relationships SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Review ID CORONAL MASS EJECTA; GREAT GEOMAGNETIC STORMS; SOLAR-WIND; RING-CURRENT; SEMIANNUAL VARIATION; PLASMA SHEET; CURRENT DISRUPTION; DECLINING PHASE; FIELD LINES; MAGNETOSPHERE AB This paper attempts to summarize the current understanding of the storm/substorm relationship by clearing up a considerable amount of controversy and by addressing the question of how solar wind energy is deposited into and is dissipated in the constituent elements that are critical to magnetospheric and ionospheric processes during magnetic storms. (1) Four mechanisms are identified and discussed as the primary causes of enhanced electric fields in the interplanetary medium responsible for geomagnetic storms. It is pointed out that in reality, these four mechanisms, which are not mutually exclusive, but interdependent, interact differently from event to event. Interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs) are found to be the primary phenomena responsible for the main phase of geomagnetic storms. The other two mechanisms, i.e., HILDCAA (high-intensity, long-duration continuous auroral electrojet activity) and the so-called Russell-McPherron effect, work to make the ICME and CIR phenomena more geoeffective. The solar cycle dependence of the various sources in creating magnetic storms has yet to be quantitatively understood. (2) A serious controversy exists as to whether the successive occurrence of intense substorms plays a direct role hn the energization of ring current particles or whether the enhanced electric field associated with southward IMF enhances the effect of substorm expansions. While most of the Dst variance during magnetic storms can be solely reproduced by changes in the large-scale electric field in the solar wind and the residuals are uncorrelated with substorms, recent satellite observations of the ring current constituents during the main phase of magnetic storms show the importance of ionospheric ions. This implies that ionospheric ions, which are associated with the frequent occurrence of intense substorms, are accelerated upward along magnetic field lines, contributing to the energy density of the storm-time ring current. An apparently new controversy regarding the relative importance of the two processes is thus created. It is important to identify the role of substorm occurrence in the large-scale enhancement of magnetospheric convection driven by solar wind electric fields. (3) Numerical schemes for predicting geomagnetic activity indices on the basis of solar/solar wind/interplanetary magnetic field parameters continue to be upgraded, ensuring reliable techniques for forecasting magnetic storms under real-time conditions. There is a need to evaluate the prediction capability of geomagnetic indices on the basis of physical processes that occur during storm time substorms. (4) It is crucial to differentiate between storms and nonstorm time substorms in terms of energy transfer/conversion processes, i.e., mechanical energy from the solar wind, electromagnetic energy in the magnetotail, and again, mechanical energy of particles in the plasma sheet, ring current, and aurora. To help answer the question of the role of substorms in energizing ring current particles, it is crucial to find efficient magnetospheric processes that heat ions up to some minimal energies so that they can have an effect on the strength of the storm time ring current. (5) The question of whether the Dst index is an accurate and effective measure of the storm time ring current is also controversial. In particular, it is demonstrated that the dipolarization effect associated with substorm expansion acts to reduce the Dst magnitude, even though the ring current may still be growing. C1 Nagoya Univ, Solar Terr Environm Lab, Toyokawa 442, Japan. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Natl Observ Athens, Inst Ionospher & Space Res, Penteli 15236, Greece. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Inst Pesquisas Espaciais, Sao Paulo, Brazil. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Calif Los Angeles, Dept Geophys & Planetary Phys, Los Angeles, CA 90024 USA. NASA, Johnson Space Flight Ctr, Houston, TX 77059 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Aeron, D-37189 Katlenburg Lindau, Germany. RP Kamide, Y (reprint author), Nagoya Univ, Solar Terr Environm Lab, Toyokawa 442, Japan. EM kamide@stelab.nagoya-u.ac.jp; bj@mpe-garching.mpg.dr; daglis@creator.space.noa.gr; gonzalez@dge.inpe.br; M.Grande@rl.ac.uk; jjoselyn@sec.noaa.gov; rmcpherron@igpp.ucla.edu; JLPhilli@ems.jsc.gov; reeves@lanl.gov; rostoker@space.ualberta.ca; ssh@avl.umd.edu; hsinger@sec.noaa.gov; btsurutani@jplsp.jpl.nasa.gov; vasyliunas@linaxl.mpae.gwdg.de RI Baumjohann, Wolfgang/A-1012-2010; Daglis, Ioannis/L-6100-2013; Reeves, Geoffrey/E-8101-2011; Grande, Manuel/C-2242-2013 OI Baumjohann, Wolfgang/0000-0001-6271-0110; Daglis, Ioannis/0000-0002-0764-3442; Reeves, Geoffrey/0000-0002-7985-8098; Grande, Manuel/0000-0002-2233-2618 NR 153 TC 200 Z9 202 U1 3 U2 36 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1998 VL 103 IS A8 BP 17705 EP 17728 DI 10.1029/98JA01426 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107BV UT WOS:000075186700040 ER PT J AU Boness, DJ Craig, MP Honigman, L Austin, S AF Boness, DJ Craig, MP Honigman, L Austin, S TI Fostering behavior and the effect of female density in Hawaiian monk seals, Monachus schauinslandi SO JOURNAL OF MAMMALOGY LA English DT Article DE Monachus schauinslandi; Hawaiian monk seals; fostering; non-offspring nursing; maternal care; density effects; pinnipeds ID NORTHERN ELEPHANT SEAL; BAT MATERNITY COLONIES; HARBOR SEAL; PHOCA-VITULINA; ALLOPARENTAL CARE; BUBALUS-BUBALIS; WATER-BUFFALO; GREY SEAL; ADOPTION; MOTHER AB Frequent nursing of pups by non-filial females (fostering) has been reported in Hawaiian monk seals (Monachus schauinslandi) at French Frigate Shoals in the Northwestern-Hawaiian Islands. We present data on the occurrence of fostering at Laysan Island, NWHI, and compare spatial patterns and behavior of seals at Laysan Island and East Island, French Frigate Shoals, to investigate the importance of density in frequency of fostering. Fostering was common at Laysan Island; 53% of 17 females nursed pups other than their own for some part of their lactation period. This level of fostering was significantly less than that at East Island, where ca. 90% of females fostered pups in 2 separate years (n = 30 in 1987 and 10 in 1989). Density of females was significantly lower at Laysan Island than East Island (0.5 versus 1.5 femaIes/1,000 m(2)), and nearest female neighbors were significantly farther away (58 versus 27 m) at Laysan Island. Stage of lactation at which fostering started, the total duration of foster care and the duration of fostering episodes did not differ between colonies. However, mean number of pups fostered per female at the denser colony (2.3 pups, East Island) was greater than at the less dense colony (1.3 pups, Laysan Island). No difference occurred between islands in relative frequency of aggressive interactions between females, which are known to result in females exchanging pups. High female density does appear to increase fostering frequency but not through female-female aggression as expected. Instead, high density increases the likelihood that separated females and pups will encounter another potential partner before reuniting. C1 Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP Boness, DJ (reprint author), Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. NR 49 TC 27 Z9 28 U1 2 U2 12 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 1998 VL 79 IS 3 BP 1060 EP 1069 DI 10.2307/1383115 PG 10 WC Zoology SC Zoology GA 114TJ UT WOS:000075624900037 ER PT J AU Xu, HHK Jahanmir, S AF Xu, HHK Jahanmir, S TI Effect of microstructure on damage tolerance in grinding dental glass-ceramics SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MATERIAL-REMOVAL; INDENTATION; MECHANISMS AB This study investigated the modes of grinding-induced subsurface damage in dental glass-ceramics and the influence of microstructure on strength degradation. A series of micaceous glass-ceramics crystallized from the same glass composition were tested. The diameter of the mica platelets in these glass-ceramics was varied via heat treatment. Grinding was performed using three diamond wheels (with diamond particle size of 40, 100, and 180 mu m, respectively) at depth of cut ranging from 5 mu m to 100 mu m. A bonded-interface technique was employed to examine the machining-induced subsurface damage. Relatively large median and lateral cracks were found in the glass-ceramic with the smallest mica platelets. In contrast, no cracks were found in the material containing large mica platelets. The ground specimens were fractured in four-point flexure to measure strength as a function of grinding conditions and mica platelet sizes. The strength of the ground specimens was reduced to approximately 30% of the strength of the polished specimens for the glass-ceramic containing the smallest mica platelets; that of the glass-ceramic with the intermediate mica platelet size was reduced to 60%. In contrast, virtually no strength loss occurred with the glass-ceramic containing large mica platelets. Microstructure was shown to determine the mode and degree of strength-controlling damage in the machining of these dental glass-ceramics. Polishing after grinding removes subsurface damage and recovers strength for the glass-ceramics containing fine mica crystals. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 20 TC 16 Z9 16 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1998 VL 13 IS 8 BP 2231 EP 2236 DI 10.1557/JMR.1998.0312 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 104AC UT WOS:000074989200029 ER PT J AU Bourne, P Arzberger, P Gilliland, G Fagan, P Berman, H Westbrook, J AF Bourne, P Arzberger, P Gilliland, G Fagan, P Berman, H Westbrook, J TI A new macromolecular structure database and its impact on molecular modelling SO JOURNAL OF MOLECULAR GRAPHICS & MODELLING LA English DT Meeting Abstract C1 Univ Calif San Diego, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. RI Bourne, Philip/C-2073-2008 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1093-3263 J9 J MOL GRAPH MODEL JI J. Mol. Graph. PD AUG-DEC PY 1998 VL 16 IS 4-6 BP 285 EP 285 PG 1 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Computer Science, Interdisciplinary Applications; Crystallography; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Computer Science; Crystallography; Mathematical & Computational Biology GA 248ZK UT WOS:000083306500053 ER PT J AU Douglas, JF Leporini, D AF Douglas, JF Leporini, D TI Obstruction model of the fractional Stokes-Einstein relation in glass-forming liquids SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 3rd International Discussion Meeting on Relaxations in Complex Systems CY JUN 30-JUL 11, 1997 CL VIGO, SPAIN SP J Non Crystalline Solids ID SUPERCOOLED O-TERPHENYL; TRACER DIFFUSION; DYNAMICS; LAW; DEPENDENCE; VISCOSITY; SHAPE AB Diffusion of tracer molecules in glass-forming liquids is modeled in terms of diffusion in an obstructed space. The obstructions, which model heterogeneities in supercooled liquids, are taken to be spherical and frozen in position for simplicity. This idealized model leads to the widely observed "fractional Stokes-Einstein (FSE) equation" (D proportional to (eta/T)(-xi), 0 < xi less than or equal to 1) relating the tracer particle diffusion coefficient D and the fluid viscosity eta. The spherical obstruction model indicates the exponent value xi = 3/5, but xi is predicted to vary somewhat with obstruction shape. Experimental values of xi are summarized for comparison with our model. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Univ Pisa, Dipartimento Fis, I-56100 Pisa, Italy. INFM, UDR Pisa, I-56100 Pisa, Italy. RP NIST, Div Polymers, Gaithersburg, MD 20899 USA. OI Leporini, Dino/0000-0002-9429-0509 NR 25 TC 61 Z9 61 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD AUG PY 1998 VL 235 BP 137 EP 141 DI 10.1016/S0022-3093(98)00501-8 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 118LC UT WOS:000075838800019 ER PT J AU Rose, AH Bruno, TJ AF Rose, AH Bruno, TJ TI The observation of OH in annealed optical fiber SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Letter ID SILICA GLASS; VITREOUS SILICA; DIFFUSION; WATER; ABSORPTION AB We have observed OH in annealed optical fibers. We attribute the OH to silica glass reactions with water and possibly hydrogen, due to the combustion of the fiber's polymer jacket. In our annealing process, fibers were heated from room temperature to about 1200 degrees C. The tiber's optical loss and the polymer jacket's combustion products were measured. Fibers heated with the jacket in place showed an OH absorption at 1390 nm, the amplitude of this absorption peaked at annealing temperatures near 950 degrees C. OH was not detected in fibers annealed with the jacket removed, Fibers held at or above 1200 degrees C began to devitrify. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, M-S 815-03,325 Broadway, Boulder, CO 80303 USA. EM arose@boulder.nist.gov NR 36 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD AUG PY 1998 VL 231 IS 3 BP 280 EP 285 DI 10.1016/S0022-3093(98)00676-0 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 112WM UT WOS:000075517700010 ER PT J AU Murray, JL McAlister, AJ Kahan, DJ AF Murray, JL McAlister, AJ Kahan, DJ TI The Al-Hf (aluminum-hafnium) system SO JOURNAL OF PHASE EQUILIBRIA LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Murray, JL (reprint author), ALCOA, Ctr Tech, Div Technol, Alloy Tech Div, Alcoa Center, PA 15069 USA. NR 14 TC 19 Z9 19 U1 1 U2 7 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1054-9714 J9 J PHASE EQUILIB JI J. Phase Equilib. PD AUG PY 1998 VL 19 IS 4 BP 376 EP 379 DI 10.1361/105497198770342111 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 108NL UT WOS:000075272300010 ER PT J AU Vanderploeg, HA Cavaletto, JF Liebig, JR Gardner, WS AF Vanderploeg, HA Cavaletto, JF Liebig, JR Gardner, WS TI Limnocalanus macrurus (Copepoda : Calanoida) retains a marine arctic lipid and life cycle strategy in Lake Michigan SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID CALANUS-HELGOLANDICUS; WAX ESTERS; ZOOPLANKTON; REPRODUCTION; FINMARCHICUS; SELECTIVITY; NEOCALANUS; GROWTH; HABITS; LONG AB Limnocalanus macrurus, an omnivorous calanoid copepod with strong carnivorous tendencies that invaded fresh water during the Pleistocene glaciation, retains a marine arctic lipid and life cycle strategy in the hypolimnion of Lake Michigan. Its maximum lipid concentration of 67% of dry mass-consisting largely of wax esters-is the highest reported for freshwater zooplankton and is among the highest reported for marine polar species. The high lipid concentration of L.macrurus runs counter to the paradigm that high wax ester concentrations are found in herbivorous, but not in carnivorous, polar species. Lipids are drawn down to extremely low levels (10% of dry mass) during the reproductive period, November-May. Reproduction in this univoltine species appears to be timed so that the new generation develops during the high abundance of prey (crustacean microzooplankton and net phytoplankton) in spring. A high wax ester content may allow egg production to start in winter when the prey concentration is low. In contrast to many polar species, the new generation moves through all copepodid stages to adult without diapausing. Copepodid 5 females have a low lipid concentration, and lipids are slowly built up in new generation adults during summer and fall before reproduction commences. This lipid and life cycle strategy may have given L.macrurus an advantage over potential freshwater competitors, such as the arctic freshwater cyclopoid copepod Cyclops scutifer, in the hypolimnia of glaciated lakes. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Vanderploeg, HA (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. OI Liebig, James/0000-0002-0433-9066; Vanderploeg, Henry/0000-0003-1358-8475 NR 46 TC 33 Z9 33 U1 0 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD AUG PY 1998 VL 20 IS 8 BP 1581 EP 1597 DI 10.1093/plankt/20.8.1581 PG 17 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 112KF UT WOS:000075493300011 ER PT J AU Molnar, GL Revay, Z Paul, RL Lindstrom, RM AF Molnar, GL Revay, Z Paul, RL Lindstrom, RM TI Prompt-gamma activation analysis using the k(0) approach SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol ID NEUTRON-CAPTURE; SCATTERING; FACILITY; HYDROGEN; COLD AB Applying the k(0) standardization method to prompt-gamma activation analysis (PGAA) offers similar benefits as in instrumental neutron activation analysis. It has been demonstrated that under constant flux conditions k(0)-factors obtained by normalizing to a titanium comparator, measured separately, yield consistent analytical sensitivity ratios. The ratio method has been generalized by using stoichiometric compounds for the determination of k(0)-factors. Since chlorine forms compounds with essentially every element and it also serves as a detector efficiency standard, k(0) values have been determined relative to chlorine as an internal standard for several analytically important elements in two reactor facilities: the thermal guided beam at the ERR in Budapest and the cold-neutron beams at the NBSR at NIST. C1 Inst Isotopes, Dept Nucl Res, H-1525 Budapest, Hungary. NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Molnar, GL (reprint author), Inst Isotopes, Dept Nucl Res, POB 77, H-1525 Budapest, Hungary. NR 17 TC 61 Z9 64 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1998 VL 234 IS 1-2 BP 21 EP 26 DI 10.1007/BF02389741 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 118XT UT WOS:000075866800004 ER PT J AU Paul, RL AF Paul, RL TI Determination of phosphorus in steels by radiochemical neutron activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The viability of radiochemical neutron activation analysis as a method for certification of phosphorus in steels was tested by analysis of SRM low alloy steels. Preliminary results are generally in agreement with certified values. The limit of detection, as defined by Currie,(1) was determined to be 5 mu g/kg. C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Paul, RL (reprint author), NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1998 VL 234 IS 1-2 BP 55 EP 58 DI 10.1007/BF02389747 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 118XT UT WOS:000075866800010 ER PT J AU En, Z Brenizer, JS Hosticka, E Gao, J Becker, DA AF En, Z Brenizer, JS Hosticka, E Gao, J Becker, DA TI Nitrogen distribution measurements by neutron induced autoradiography SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol ID TRACK AB A method utilizing plastic track detectors was developed to determine the nitrogen distribution and concentration in the presence of boron in metals. Experiments were performed at the UVAR (cadmium ratio similar to 25) and the NIST Reactor (cadmium ratio similar to 3000). The minimum detectable concentration of nitrogen at a given concentration of boron has been estimated using the detector's response to B-10(n,alpha)Li-7 reaction products in terms of track size distribution. The capability of the technique to detect nitrogen in the presence of boron has been demonstrated using 316L stainless steel with a nitrogen concentration of similar to 560 ppm and a boron concentration of similar to 0.86 ppm. C1 Uzbek Acad Sci, Inst Nucl Phys, Tashkent 702132, Uzbekistan. Univ Virginia, Dept Mech & Aerosp Engn, Charlottesville, VA 22903 USA. NIST, Nucl Method Grp, Div Analyt Chem, CSTL, Gaithersburg, MD 20899 USA. RP En, Z (reprint author), Uzbek Acad Sci, Inst Nucl Phys, Tashkent 702132, Uzbekistan. NR 9 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1998 VL 234 IS 1-2 BP 59 EP 63 DI 10.1007/BF02389748 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 118XT UT WOS:000075866800011 ER PT J AU Schultz, MK Burnett, W Inn, KGW Smith, G AF Schultz, MK Burnett, W Inn, KGW Smith, G TI Geochemical partitioning of actinides using sequential chemical extractions: Comparison to stable elements SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB We have developed a sequential extraction technique for determining the geochemical partitioning of Am, Pu, and U in soils and sediments. Stable element analyses were combined with radiometric measurements to determine the most probable geochemical host phases of these actinides in reference sediment IAEA-135. Am-241 results indicate an association with carbonate minerals and organic matter. The extraction profile of U-238 was similar to that of refractory elements Al, Ti, and K. Pu-239/240 data suggest a fractionation of Pu into Fe-bearing phases of varying solubility. The reproducibility of the method was quite good (replicates agreed to within 10% at a 95% confidence level). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. RP Schultz, MK (reprint author), Natl Inst Stand & Technol, 245-C114, Gaithersburg, MD 20899 USA. NR 17 TC 20 Z9 20 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1998 VL 234 IS 1-2 BP 251 EP 256 DI 10.1007/BF02389780 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 118XT UT WOS:000075866800043 ER PT J AU Ostrovsky, LA Sutin, AM Soustova, IA Matveyev, AI Potapov, AI AF Ostrovsky, LA Sutin, AM Soustova, IA Matveyev, AI Potapov, AI TI Nonlinear, low-frequency sound generation in a bubble layer: Theory and laboratory experiment SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The difference-frequency sound generation as a result of interaction of two high-frequency harmonic waves in a bubble layer in water is investigated both theoretically and experimentally. Because the sound speed in the layer is less than that outside, the layer has resonance properties. As was shown before, this can considerably increase the efficiency of the nonlinear frequency transformation. However, unlike the cases considered before, the layer resonance is practically achievable only at the low (difference) frequency, whereas the high-frequency signal (pump) resonates at individual bubbles and then it strongly dissipates. Here the results of an experiment with a bubble layer with a thickness of about 10 cm in an anechoic tank are presented. One of the incident (primary) wave frequencies was 60 kHz, whereas the other could be varied, thus providing the low-frequency signal in the range of 0.8-14.8 kHz. Due to the first-mode layer resonance, this secondary signal had a pronounced maximum at a frequency of 2.4 kHz. The high attenuation of pump waves was due to resonant bubbles. A theory which agrees with the experimental results reasonably well, is developed for this type of interaction. (C) 1998 Acoustical Society of America. [S0001-4966(98)04608-6] C1 Univ Colorado, NOAA, CIRES, Environm Technol Lab, Boulder, CO 80303 USA. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. RP Ostrovsky, LA (reprint author), Univ Colorado, NOAA, CIRES, Environm Technol Lab, 325 Broadway,R-E-ETI, Boulder, CO 80303 USA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 12 TC 10 Z9 10 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD AUG PY 1998 VL 104 IS 2 BP 722 EP 726 DI 10.1121/1.423308 PN 1 PG 5 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 108FF UT WOS:000075254800015 ER PT J AU Hoff, JW Borgoul, PV Tuncel, G Ondov, JM Kelly, WR Chen, LT AF Hoff, JW Borgoul, PV Tuncel, G Ondov, JM Kelly, WR Chen, LT TI Feasibility of applying a stable isotopic tracer for direct determination of dry particulate deposition to soybean plants SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID ATMOSPHERIC DEPOSITION; AEROSOL-PARTICLES; BOUNDARY-LAYER; CHERNOBYL; VEGETATION; EXCHANGE; ACCIDENT; ELEMENTS; SURFACES; FALLOUT AB A stable rare-earth isotopic tracer was used to measure the deposition of KNO3 particles on soybean leaves by direct measurement of the tracer on the plant surfaces by thermal-ionization mass spectrometry. Submicrometer particles, made from a solution containing 3 mu g mL(-1) neodymium isotope (Nd-148, 87.9%) and 1,000 mu g mL(-1) KNO3, were dispersed with a two-fluid nozzle and released upwind of a soybean field. Total suspended- and size-fractionated-aerosol particles were collected on an open-face filter and in a micro-orifice impactor, respectively, at a distance of 40 m from the release point. Soybean leaves exposed to the plume were collected at distances ranging from 25 to 100 m. As little as 5.5 pg of the tracer (i.e., excess Nd-148) was detected in soybean leaves at signal-to-noise ratios ranging from 7,500 to 240,000, in the presence of 200 to 2,700 pg of naturally occurring Nd. The dry-particle deposition velocity, determined from the ratio of the aerial concentration and directly deposited aerosol (geometric mass mean diameter, 0.20 mu m) flux, and its corresponding analytical uncertainty were 0.30 cm sec(-1) and 2.5%, respectively. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Technol Adm, Gaithersburg, MD 20899 USA. RP Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. NR 41 TC 3 Z9 3 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1096-2247 EI 2162-2906 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD AUG PY 1998 VL 48 IS 8 BP 721 EP 728 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 116PK UT WOS:000075733600005 PM 28060683 ER PT J AU Lawn, BR AF Lawn, BR TI Indentation of ceramics with spheres: A century after Hertz SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Review ID HETEROGENEOUS GRAIN-STRUCTURE; CONTACT DAMAGE; FRACTURE-TOUGHNESS; SILICON-CARBIDE; CYCLIC FATIGUE; CRACK-GROWTH; POLYCRYSTALLINE CERAMICS; STRENGTH DEGRADATION; BRITTLE MATERIALS; STRESS-ANALYSIS AB In this article we review the nature and mechanics of damage induced in ceramics by spherical indenters, from the classical studies of Hertz over a century ago to the present day. Basic descriptions of continuum elastic and elastic-plastic contact stress fields are first given. Two distinct modes of damage are then identified: Hertzian cone cracks, in relatively hard, homogeneous materials, such as glasses, single crystals, fine-grain ceramics (tensile, "brittle" mode); and diffuse subsurface damage zones, in relatively tough ceramics with heterogeneous microstructures (shear, "quasi-plastic" mode). Ceramographic evidence is presented for the two damage types in a broad range of materials, illustrating how an effective brittle-ductile transition can be engineered by coarsening and weakening the grain structure. Continuum analyses for cone fracture and quasi plasticity, using Griffith-Irwin fracture mechanics and yield theory, respectively, are surveyed. Recent micromechanical models of the quasi-plastic mode are also considered, in terms of grain-localized "shear faults" with extensile "wing cracks." The effect of contact-induced damage on the ensuing strength properties of both brittle and quasi-plastic ceramics is examined. Whereas cone cracking causes abrupt losses in strength, the effect of quasi-plastic damage is more gradual-so that more heterogeneous ceramics are more damage tolerant. On the other hand, quasi-plastic ceramics are subject to accelerated strength losses in extreme cyclic conditions ("contact fatigue"), because of coalescence of attendant microcracks, with implications concerning wear resistance and machinability. Extension of Hertzian contact testing to novel layer structures with hard, brittle outer layers and soft, tough underlayers, designed to impart high toughness while preserving wear resistance, is described. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 134 TC 430 Z9 432 U1 7 U2 113 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 AUG PY 1998 VL 81 IS 8 BP 1977 EP 1994 PG 18 WC Materials Science, Ceramics SC Materials Science GA 110FB UT WOS:000075368600001 ER PT J AU Levin, I Brandon, D AF Levin, I Brandon, D TI Metastable alumina polymorphs: Crystal structures and transition sequences SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ALPHA-ALUMINA; GAMMA-ALUMINA; SAPPHIRE ALPHA-AL2O3; PHASE-TRANSFORMATION; DELTA-ALUMINA; OXIDE FILMS; WATER-VAPOR; BASAL SLIP; GROWTH; GAMMA-AL2O3 AB The available literature on the crystal structure of the metastable alumina polymorphs and their associated transitions is critically reviewed and summarized. All the metastable alumina structures have been identified as ordered or partially ordered cation arrays on the interstitial sites of an approximately close-packed oxygen sublattice (either face-centered cubic or hexagonal close packed). The analysis of the symmetry relations between reported alumina polymorphs having an approximately face-centered cubic packing of the oxygen anions allows for an exact interpretation of all the complex domain structures that have been observed experimentally. Possible mechanisms for the phase transitions between the different alumina polymorphs also are discussed. C1 Technion Israel Inst Technol, Fac Mat Engn, IL-32000 Haifa, Israel. RP Levin, I (reprint author), NIST, Div Ceram, MSEL, Bethesda, MD 20889 USA. RI Levin, Igor/F-8588-2010 NR 80 TC 591 Z9 609 U1 25 U2 220 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 1998 VL 81 IS 8 BP 1995 EP 2012 PG 18 WC Materials Science, Ceramics SC Materials Science GA 110FB UT WOS:000075368600002 ER PT J AU Lee, SK Lee, KS Lawn, BR Kim, DK AF Lee, SK Lee, KS Lawn, BR Kim, DK TI Effect of starting powder on damage resistance of silicon nitrides SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HETEROGENEOUS GRAIN-STRUCTURE; HERTZIAN CONTACT DAMAGE; FRACTURE-TOUGHNESS; BRITTLE SOLIDS; CERAMICS; STRENGTH; MICROSTRUCTURE; FAILURE; FATIGUE; GROWTH AB The role of starting powder in the resistance of silicon nitride (Si3N4) ceramics to strength-impairing contact damage is studied. Si2N4 materials are prepared from three starting powders, at selectively increasing hot-pressing temperatures to coarsen the microstructures: (i) from relatively coarse alpha-phase powder, essentially equiaxed alpha-Si3N4 grains, with limited, slow transformation to beta-Si3N4 grains toward the latter half of the temperature range; (ii) from relatively fine alpha-phase powder, a more rapid transformation to beta-Si3N4, with attendant grain elongation; (iii) from fine beta-phase powder, an essentially equiaxed beta-Si3N4 structure over the entire temperature range. The resulting microstructures thereby provide a spectrum of beta/alpha phase ratios and grain sizes and shapes for investigation. Indentations with hard spheres (Hertzian test) are used to induce damage into the Si3N4 specimens. Examination of the indentation sites indicates a competition between brittle and quasi-plastic damage modes: in structures with relatively equiaxed grains, the damage takes the form of classical cone cracking; in structures with large elongate grains, the damage is distributed beneath the contact as grain-localized microfailures within a subsurface "yield" zone. Bend tests on specimens containing single-cycle contact damage reveal those structures with well-developed cone cracks to be highly susceptible to strength degradation. The microstructures with the greatest resistance to strength loss are those formed from fine a-phase starting powder at intermediate firing temperatures (1700 degrees C), with characteristic large, elongate beta grains. Implications of the results in the context of other mechanical properties, e.g., toughness, wear, and fatigue resistance, are discussed. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. RP Caterpillar Inc, Ctr Tech, Adv Mat Technol, Mossville, IL 61552 USA. RI Kim, Do Kyung/C-2039-2011 OI Kim, Do Kyung/0000-0001-9092-9427 NR 43 TC 26 Z9 27 U1 0 U2 5 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 AUG PY 1998 VL 81 IS 8 BP 2061 EP 2070 PG 10 WC Materials Science, Ceramics SC Materials Science GA 110FB UT WOS:000075368600009 ER PT J AU Brooks, RA Vymazal, J Goldfarb, RB Bulte, JWM Aisen, P AF Brooks, RA Vymazal, J Goldfarb, RB Bulte, JWM Aisen, P TI Relaxometry and magnetometry of ferritin SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article DE ferritin; superparamagnetism; T-1; T-2; relaxometry ID BRAIN IRON; RELAXATION; CORE; MAGNETOFERRITIN; DEPENDENCE; COMPLEX; FIELD; RATS; IONS; MRI AB By combining nuclear magnetic relaxometry on 39 ferritin samples with different iron loading with magnetometry, results were obtained that suggest a new interpretation of the core structure and magnetic properties of ferritin. These studies provide evidence that, contrary to most earlier reports, the ferritin core is antiferromagnetic (AFM) even at body temperature and possesses a superparamagnetic (SPM) moment due to incomplete cancellation of antiparallel sublattices, as predicted by Neel's theory. This moment also provides a likely explanation for the anomalous T-2 shortening in ferritin solution. However, the number of SPM moments derived from this model is less than the number of ferritin molecules determined chemically, and a similar discrepancy was found by retrospectively fitting previously published magnetometry data. In other words, only a fraction of the ferritin molecules seem to be SPM. The studies also provide evidence for paramagnetic (PM) Curie-Weiss iron ions at the core surface, where the local Neel temperature is lower; these ions are apparently responsible for the weaker T-1 shortening. In fact, the conversion of uncompensated AFM lattice ions to PM ions could explain the small number of SPM particles. The apparent Curie Law behavior of ferritin thus appears to be a coincidental result of different temperature dependences of the PM and SPM components. C1 NINDS, Neuroimaging Branch, NIH, Bethesda, MD 20892 USA. NIH, Lab Diagnost Radiol Res, Bethesda, MD 20892 USA. Natl Inst Stand & Technol, Boulder, CO USA. Albert Einstein Coll Med, Bronx, NY 10467 USA. RP NINDS, Neuroimaging Branch, NIH, Bldg 10,Room 5N214, Bethesda, MD 20892 USA. RI Bulte, Jeff/A-3240-2008; Goldfarb, Ronald/A-5493-2011 OI Bulte, Jeff/0000-0003-1202-1610; Goldfarb, Ronald/0000-0002-1942-7974 FU NIDDK NIH HHS [DK15056] NR 38 TC 91 Z9 91 U1 2 U2 13 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0740-3194 EI 1522-2594 J9 MAGN RESON MED JI Magn. Reson. Med. PD AUG PY 1998 VL 40 IS 2 BP 227 EP 235 DI 10.1002/mrm.1910400208 PG 9 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 107NC UT WOS:000075214500007 PM 9702704 ER PT J AU de Larrard, F Ferraris, CF Sedran, T AF de Larrard, F Ferraris, CF Sedran, T TI Fresh concrete: A Herschel-Bulkley material SO MATERIALS AND STRUCTURES LA English DT Article AB Some preliminary results of an experimental program on the rheological behavior of fresh concrete are presented. In the rheological tests, performed with a plane-to-plane rheometer, it appears that the relationship between torque and rotation speed is not exactly linear. The fresh concrete behavior is better described by the Herschel-Bulkley model: tau = tau'(n) + a (gamma) over dot (b); tau and (gamma) over dot are the shear stress and the strain gradient applied to the specimen, respectively. tau'(o), a and b are three material parameters describing the concrete behavior. Among other advantages, this new description avoids the problem negative yield stress encountered with the Bingham model. C1 Lab Cent Ponts & Chaussees, Paris, France. NIST, Gaithersburg, MD 20899 USA. RP de Larrard, F (reprint author), Lab Cent Ponts & Chaussees, Paris, France. NR 11 TC 75 Z9 76 U1 2 U2 9 PU R I L E M PI CACHAN PA PAVILLON DES JARDINS, 61 AV DU PRESIDENT WILSON, 94235 CACHAN, FRANCE SN 0025-5432 J9 MATER STRUCT JI Mater. Struct. PD AUG-SEP PY 1998 VL 31 IS 211 BP 494 EP 498 PG 5 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 115NV UT WOS:000075672300009 ER PT J AU Palkar, VR Thapa, D Multani, MS Malghan, SG AF Palkar, VR Thapa, D Multani, MS Malghan, SG TI Densification of nanostructured alumina assisted by rapid nucleation of alpha-alumina SO MATERIALS LETTERS LA English DT Article DE alumina; sintering; phase transformation; sol-gel; nanostructured AB We have shown that it is possible to achieve dense nanostructured alumina, with density +98% of the theoretical maximum at sintering temperature as low as 1300 degrees C without any help of additives or alpha-seeding. The drastic reduction in sintering temperature from 1600 degrees C to 1300 degrees C is possible by rapid nucleation of the stable alpha-alumina phase. It is achieved by introducing the compacted pellet of bayrite fine particles derived by the sol-gel process, in a furnace at 1250 degrees C, the temperature high enough for the rapid transformation to alpha-alumina. Since the nucleation rate is higher than the growth rate of particles, large and extensive pore network which usually develops during the sequential transformation to alpha-Al2O3 could be avoided. This newly developed cost effective simple process of sintering through rapid nucleation win help to fulfill the demand of highly sintered nanostructured alumina for various industrial applications. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Tata Inst Fundamental Res, Mumbai 400005, India. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Palkar, VR (reprint author), Tata Inst Fundamental Res, Homi Bhabha Rd, Mumbai 400005, India. NR 10 TC 11 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD AUG PY 1998 VL 36 IS 5-6 BP 235 EP 239 DI 10.1016/S0167-577X(98)00044-5 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 103YG UT WOS:000074985000001 ER PT J AU Kain, JS Fritsch, JM AF Kain, JS Fritsch, JM TI Multiscale convective overturning in mesoscale convective systems: Reconciling observations, simulations, and theory SO MONTHLY WEATHER REVIEW LA English DT Article ID 10-11 JUNE 1985; MIDLATITUDE SQUALL LINE; NUMERICAL-SIMULATION; MICROPHYSICAL EVOLUTION; FLORIDA CUMULONIMBUS; CUMULUS PARAMETERIZATION; PRECIPITATION STRUCTURE; SENSITIVITY TESTS; MODEL DESCRIPTION; UNITED-STATES AB An analysis of how parameterized convection interacts with hydrostatic, explicitly resolved precipitation processes to represent multiscale convective overturning in a mesoscale-resolution numerical simulation is presented. Critically important ingredients of the successful simulation are identified and the degree to which simulations are consistent with observations and theoretical considerations is examined. Of particular concern is how convective parameterization routines reconcile the deep moist absolutely unstable structures that form in mesoscale convective systems. It is found that these structures arise primarily from resolvable-scale vertical motion and that the model responds to these structures not only by maintaining parameterized convection, but also by developing a hydrostatic manifestation of convective overturning on its smallest resolvable horizontal scales. The strongest and most distinctive mesoscale perturbations develop in regions where the mesoscale contribution to convective overturning rivals, and often exceeds, the parameterized contribution. Because the internal features of mesoscale convective systems are poorly resolved by meso-beta-scale grid elements in this simulation, their scale tends to be overestimated. However, the model results and observations suggest that models must account for multiscale convective overturning in order to properly characterize convective mass transports. Therefore, it is argued that the manner of representation of the convective process, wherein deep convection is allowed to occur partly as a parameterized subgrid-scale process and partly as a hydrostatic manifestation of convective overturning, is likely to give the optimal numerical solution for modeling systems with meso-beta-scale resolution. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM kain@nssl.noaa.gov NR 63 TC 48 Z9 50 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1998 VL 126 IS 8 BP 2254 EP 2273 DI 10.1175/1520-0493(1998)126<2254:MCOIMC>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110TN UT WOS:000075396600012 ER PT J AU Derber, JC Wu, WS AF Derber, JC Wu, WS TI The use of TOVS cloud-cleared radiances in the NCEP SSI analysis system SO MONTHLY WEATHER REVIEW LA English DT Article ID OBSERVING SYSTEM; INTERPOLATION; ASSIMILATION AB With improved assimilation techniques, it is now possible to directly assimilate cloud-cleared radiances, rather than temperature and moisture retrievals, in objective analyses. The direct use of the cloud-cleared radiances became the operational technique for using satellite sounding data at the National Centers for Environmental Prediction (NCEP) in October 1995. The methodology for using the data (including bias correction, ozone analysis, skin temperature analysis, and quality control) are described in this paper. The impact of the direct use of the radiances compared to the previously operational use of satellite sounding data shows considerable improvement in NCEP's forecast skill, especially in the Southern Hemisphere. It is anticipated that additional positive impacts will occur with application of the technique to other remotely sensed data. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC 20233 USA. Gen Sci Corp, Laurel, MD USA. RP Derber, JC (reprint author), Natl Ctr Environm Predict, Environm Modeling Ctr, W-NP23,World Weather Bldg, Washington, DC 20233 USA. NR 20 TC 268 Z9 286 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1998 VL 126 IS 8 BP 2287 EP 2299 DI 10.1175/1520-0493(1998)126<2287:TUOTCC>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110TN UT WOS:000075396600014 ER PT J AU Allman, BE Jacobson, DL Lee, WT Littrell, KC Werner, SA AF Allman, BE Jacobson, DL Lee, WT Littrell, KC Werner, SA TI Neutron interferometry instrumentation at MURR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE neutron interferometry; neutron optics; neutron polarization; quantum optics ID INDUCED QUANTUM INTERFERENCE; PHASE-SHIFT; NUCLEAR-RESONANCE; DYNAMICAL PHASES; COHERENCE; MATTER; MECHANICS; ROTATION; GRAVITY AB During the last two decades more than 35 fundamental quantum interference experiments have been performed using the perfect-silicon-crystal neutron interferometer. About one-half of these experiments have been carried out at the University of Missouri Research Reactor Center (MURR). In this paper we describe in some detail the instrumentation and the neutron optics of the two neutron interferometry setups currently situated at this 10 MW reactor. (C) 1998 Elseveir Science B.V. All rights reserved. C1 Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Univ Missouri, Res Reactor Ctr, Columbia, MO 65211 USA. Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Werner, SA (reprint author), Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. EM werner@nopt.physics.missouri.edu RI Littrell, Kenneth/D-2106-2013 OI Littrell, Kenneth/0000-0003-2308-8618 NR 58 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 1998 VL 412 IS 2-3 BP 392 EP 419 DI 10.1016/S0168-9002(98)00479-3 PG 28 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 116AB UT WOS:000075697800021 ER PT J AU Karen, DJ Draughn, R Fulton, M Ross, P AF Karen, DJ Draughn, R Fulton, M Ross, P TI Bone strength and acetylcholinesterase inhibition as endpoints in chlorpyrifos toxicity to Fundulus heteroclitus SO PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY LA English DT Article AB Brain acetylcholinesterase (AChE) inhibition was measured during 4-week and 4-day episodic exposures to chlorpyrifos. Organisms were exposed to a seawater (-) control, an acetone (+) control (0.1%), and 0.625, 1.25, 2.5, 5.0, and 10.0 mu g of chlorpyrifos.L-l in each test. These episodic exposures significantly depressed AChE activity at 2.5, 5.0, and 10.0 mu g.L-1 (weekly test) and at 1.25, 2.5, 5.0, and 10.0 mu g.L-1 (daily test). Six-hour pulsed exposure to chlorpyrifos inhibited brain AChE activity at concentrations as low as 1.25 mu g.L-1. Stress at failure of caudal vertebrae following episodic exposure was also tested. Analysis of samples from daily 6-h treatments found no differences after 2 days; however, vertebrae were significantly weaker (than controls) after 4 days. Analysis of weekly 6-h exposures found weaker caudal vertebrae after 2 weeks but not after 4 weeks, (C) 1998 Academic Press. C1 Univ Charleston, Charleston, SC 29402 USA. Med Univ S Carolina, Dept Mat Sci, Charleston, SC 29425 USA. Natl Marine Fisheries Serv, Charleston, SC 29422 USA. Colorado Sch Mines, Golden, CO 80401 USA. RP Karen, DJ (reprint author), Clemson Univ, Dept Environm Toxicol, Inst Wildlife & Environm Toxicol, POB 709, Pendleton, SC 29630 USA. NR 35 TC 17 Z9 17 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0048-3575 J9 PESTIC BIOCHEM PHYS JI Pest. Biochem. Physiol. PD AUG 1 PY 1998 VL 60 IS 3 BP 167 EP 175 DI 10.1006/pest.1998.2345 PG 9 WC Biochemistry & Molecular Biology; Entomology; Physiology SC Biochemistry & Molecular Biology; Entomology; Physiology GA 111GX UT WOS:000075429900003 ER PT J AU Lunetta, RS Lyon, JG Guindon, B Elvidge, CD AF Lunetta, RS Lyon, JG Guindon, B Elvidge, CD TI North American landscape characterization dataset development and data fusion issues SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID SATELLITE DATA; DEFORESTATION AB With the launch of Landsat 1 on 23 July 1972, the United States initiated the capability for land, resource monitoring. from space. Over a 20-year period, the Landsat Multi-Spectral Scanner (MSS) sensor collected data documenting land-cover conditions over the majority of the globe. The global change research community has prioritized reducing the uncertainty associated with land cover-change as a major constituent of importance to balancing the global carbon cycle. The Mss archive currently represents the best available, continuous public source of relatively high resolution imagery for the monitoring of land cover over the 1972-1992 period. The North American Landscape Characterization project was designed to exploit this archive by providing standardized satellite data sets to support land-cover change analysis. Land-cover categorization products derived from Mss data alone provide only a general characterization of land-cover condition and change. A data fusion approach using a post classification technique is presented as a cost-effective method for delineating land cover at appropriate thematic and spatial resolutions; to support a quantitative inventory of forest carbon stocks. Issues related to assessing the accuracy of carbon inventory datasets is presented, and a two-step model is proposed for accuracy assessment. C1 US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Canada Ctr Remote Sensing, Ottawa, ON K1A 0Y7, Canada. NOAA NESDIS, Natl Geophys Data Ctr, Boulder, CO 80303 USA. RP Lunetta, RS (reprint author), US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. RI Elvidge, Christopher/C-3012-2009 NR 28 TC 49 Z9 50 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD AUG PY 1998 VL 64 IS 8 BP 821 EP 829 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 106BE UT WOS:000075109200011 ER PT J AU Aglitskiy, Y Serpa, FG Meyer, ES Gillaspy, JD Brown, CM Faenov, AY Pikuz, TA AF Aglitskiy, Y Serpa, FG Meyer, ES Gillaspy, JD Brown, CM Faenov, AY Pikuz, TA TI The use of a spherically curved crystal spectrometer for X-ray measurements on electron beam ion trap SO PHYSICA SCRIPTA LA English DT Article ID SPECTROSCOPIC INVESTIGATIONS; MICA CRYSTALS; PLASMA; PERFORMANCE; WAVELENGTHS; REFLECTION; ALPHA; LINE AB Spherically curved crystal spectrometers are demonstrated for use on an Electron Beam Ion Trap (EBIT) for the first time. Such spectrometers are characterized by high light collection efficiency and relative insensitivity to source position, simultaneously giving them an advantage that no X-ray spectrometer previously used on an EBIT has had. One of the spectrometer crystals tested is composed of mica, giving it the additional advantage that it can be used with reasonable efficiency up to very high order, allowing spectra to span a broad wavelength range from 0.5 Angstroms to 20 Angstroms. Spectra from Ne-like barium and He-like argon are presented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. VNIIFTRI, Multicharged Ions Spectra Data Ctr, Mendeleevo 141570, Moscow Region, Russia. RP Aglitskiy, Y (reprint author), Sci Applicat Int Corp, Mclean, VA 22102 USA. NR 32 TC 10 Z9 12 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG PY 1998 VL 58 IS 2 BP 178 EP 181 DI 10.1088/0031-8949/58/2/012 PG 4 WC Physics, Multidisciplinary SC Physics GA 110AG UT WOS:000075356700012 ER PT J AU Beier, T Mohr, PJ Persson, H Soff, G AF Beier, T Mohr, PJ Persson, H Soff, G TI Influence of nuclear size on QED corrections in hydrogenlike heavy ions SO PHYSICAL REVIEW A LA English DT Article ID SELF-ENERGY CORRECTION; BOUND ATOMIC ELECTRON; LITHIUM-LIKE ATOMS; LAMB-SHIFT; POLARIZATION CONTRIBUTION; RECOIL CORRECTIONS; MULTICHARGED IONS; ALPHA-Z; URANIUM; RENORMALIZATION AB The influence of the nuclear size and shape on quantum electrodynamic corrections to electron binding energies in heavy hydrogenlike ions is evaluated. For the self-energy, numerical values for the energy shift that take into account the size of the nucleus are given for 1S(1/2)-, 2S(1/2)-, and 2P(1/2)-states in the Z range from 26 to 110. Simple parametrizations are derived for the dependence of the self-energy and the vacuum polarization on the nuclear radius, which allow corrections to be made for small deviations from the currently known nuclear radii. The influence of nuclear size on second-order quantum electrodynamic corrections is examined for the two-loop vacuum-polarization contributions. The contribution is found to be experimentally indistinguishable from other contributions to the energy shift which an of nonquantum electrodynamic origin. [S1050-2947(98)03407-6]. C1 Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden, Germany. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Chalmers Univ Technol, Dept Phys, SE-41296 Goteborg, Sweden. Univ Gothenburg, SE-41296 Goteborg, Sweden. RP Beier, T (reprint author), Tech Univ Dresden, Inst Theoret Phys, Mommsenstr 13, D-01062 Dresden, Germany. NR 55 TC 41 Z9 42 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1998 VL 58 IS 2 BP 954 EP 963 DI 10.1103/PhysRevA.58.954 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 110NA UT WOS:000075386200026 ER PT J AU Rafac, RJ Tanner, CE AF Rafac, RJ Tanner, CE TI Measurement of the ratio of the cesium D-line transition strengths SO PHYSICAL REVIEW A LA English DT Article ID PRECISION LIFETIME MEASUREMENTS; MATRIX-ELEMENTS; ENERGIES; ATOMS AB High-precision laser absorption spectroscopy in a thermal vapor cell is used in the measurement of the ratio of the D-line transition strengths in the cesium atom. We find \[6p(2)P3/2\\(r) over right arrow\\6s(2)S(1/2)]\(2)/ \[6p(2)P1/2\\(r) over right arrow\\6s(2)S(1/2)]\(2) = 1.9809(9), which compares favorably with the ratio calculated from the most precise lifetime measurements of these states and the predictions of nb initio calculation. We also verify the predictions of impact-regime line-broadening calculations for densities of order 10(18) atoms per m(3). Theoretical implications and future experimental promise are discussed. [S1050-2947(98)05008-2]. C1 Univ Notre Dame, Notre Dame, IN 46556 USA. RP Rafac, RJ (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 27 TC 38 Z9 38 U1 2 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 AUG PY 1998 VL 58 IS 2 BP 1087 EP 1097 DI 10.1103/PhysRevA.58.1087 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 110NA UT WOS:000075386200038 ER PT J AU Ioffe, A Jacobson, DL Arif, M Vrana, M Werner, SA Fischer, P Greene, GL Mezei, F AF Ioffe, A Jacobson, DL Arif, M Vrana, M Werner, SA Fischer, P Greene, GL Mezei, F TI Precision neutron-interferometric measurement of the coherent neutron-scattering length in silicon SO PHYSICAL REVIEW A LA English DT Article AB The neutron-interferometry (NI) technique provides a precise and direct way to measure the bound, coherent scattering lengths b of low-energy neutrons in solids, liquids, or gases. The potential accuracy of NI to measure b has not been fully realized in past experiments, due to systematic sources of error. We have used a method which eliminates two of the main sources of error to measure the scattering length of silicon with a relative standard uncertainty of 0.005%. The resulting value, b=4.1507(2) fm, is in agreement with the current accepted value, but has an uncertainty five times smaller. [S1050-2947(98)04808-2]. C1 Hahn Meitner Inst Kernforsch Berlin GmbH, Berlin Neutron Scattering Ctr, D-14109 Berlin, Germany. St Petersburg Nucl Phys Inst, Gatchina 188350, Leningrad Distr, Russia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Acad Sci Czech Republ, Inst Nucl Phys, CZ-25068 Rez, Czech Republic. Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ioffe, A (reprint author), Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. NR 16 TC 24 Z9 24 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1998 VL 58 IS 2 BP 1475 EP 1479 DI 10.1103/PhysRevA.58.1475 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 110NA UT WOS:000075386200080 ER PT J AU Julienne, PS Burnett, K Band, YB Stwalley, WC AF Julienne, PS Burnett, K Band, YB Stwalley, WC TI Stimulated Raman molecule production in Bose-Einstein condensates SO PHYSICAL REVIEW A LA English DT Article ID ATOMS; PHOTOASSOCIATION; GAS AB A Raman photoassociation process can be used to form translationally cold molecules from a Bose-Einstein condensate. Coupled-channels scattering calculations show that the rate coefficient for coherent production of molecules in specific target states, > 10(-10) cm(3)/s, can greatly exceed the rate coefficient for heating and loss channels due to excited-state spontaneous decay. This implies the feasibility of rapid coherent conversion of atom pairs in a condensate to molecules on a time scale short compared to the trap oscillation time. [S1050-2947(98)50708-1]. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Ben Gurion Univ Negev, Dept Chem, Beer Sheva, Israel. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Julienne, PS (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 16 TC 80 Z9 80 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1998 VL 58 IS 2 BP R797 EP R800 DI 10.1103/PhysRevA.58.R797 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 110NA UT WOS:000075386200004 ER PT J AU Huang, Q Santoro, A Lynn, JW Erwin, RW Borchers, JA Peng, JL Ghosh, K Greene, RL AF Huang, Q Santoro, A Lynn, JW Erwin, RW Borchers, JA Peng, JL Ghosh, K Greene, RL TI Structure and magnetic order in La1-xCaxMnO3 (0 < x <= 0.33) SO PHYSICAL REVIEW B LA English DT Article ID PEROVSKITE; CHEMISTRY AB The nuclear and magnetic structures of La1 - xCaxMnO3 have been studied by neutron powder diffraction methods for the compositions x= 0.06, 0.15, 0.175, 0.25, and 0.33. At low concentrations of Ca (x = 0.06) the oxidized sample contains cation vacancies and the structure is ferromagnetic, while in reduced samples all atomic sites are fully occupied and the structure is antiferromagnetic. This result explains the discrepancies found in published phase diagrams. In the samples with compositions x greater than or equal to 0.15, the structural distortions associated with the magnetic and electronic transitions increase with increasing Ca content. These distortions consist mainly of an increase in the tilting of the MnO6 octahedra and a consequent sharp decrease of the Mn-Mn separations as the system becomes metallic and ferromagnetic. These readjustments of the structure may be responsible for the metallic character of the bonds at the transition from insulating to metallic behavior. The magnetic-field dependence of the lattice parameters, studied in sample x= 0.33 at two fixed temperatures (270 and 240 K), demonstrates that there is strong coupling between the magnetization and the structural properties in this system. [S0163-1829(98)06329-2]. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Mat Res Program, College Pk, MD 20742 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Huang, Q (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 14 TC 139 Z9 139 U1 2 U2 11 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 AUG 1 PY 1998 VL 58 IS 5 BP 2684 EP 2691 DI 10.1103/PhysRevB.58.2684 PG 8 WC Physics, Condensed Matter SC Physics GA 108UQ UT WOS:000075284300059 ER PT J AU Yildirim, T Harris, AB Shender, EF AF Yildirim, T Harris, AB Shender, EF TI Frustration and quantum fluctuations in Heisenberg fcc antiferromagnets SO PHYSICAL REVIEW B LA English DT Article ID KAGOME ANTIFERROMAGNET; MAGNON GAP; DISORDER; ORDER; SYSTEM AB We consider the quantum Heisenberg antiferromagnet on a face-centered-cubic lattice in which J, the second-neighbor (intrasublattice) exchange constant, dominates J', the first-neighbor (intersublattice) exchange constant. It is shown that the continuous degeneracy of the classical ground state with four decoupled (in a mean-field sense) simple cubic antiferromagnetic sublattices is removed so that at second order in J'/J the spins are collinear. Here we study the degeneracy between the two inequivalent collinear structures by analyzing the contribution to the spin-wave zero-point energy which is of the form H(eff/)J=C-0 + C(4)sigma(1)sigma(2)sigma(3)sigma(4)(J'/J)(4) + O(J'/J)(5), where sigma(1) specifies the phase of the i th collinear sublattice, Co depends on J'/J but not on the a's, and C-4 is a positive constant. Thus the ground state is one in which the product of the sigma's is - 1. This state, known as the second kind of type A, is stable in the range \J'\ <2 \J\ for large S. Using interacting spin-wave theory, it is shown that the main effect of the zero-point fluctuations is at small wave vector and call be well modeled by an effective biquadratic interaction of the form Delta E-Q(eff) = - 1/2 Q Sigma(i,j)[S(i).S(j)](2)/S-3. This interaction opens a spin gap by causing the extra classical zero-energy modes to have a nonzero energy of order J' root S. We also study the dependence of the zero-point spin reduction on J'/J and the sublattice magnetization on temperature. The resulting experimental consequences are discussed. C1 Univ Maryland, College Pk, MD 20742 USA. NIST, Gaithersburg, MD 20899 USA. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Russian Acad Sci, Inst Nucl Phys, St Petersburg, Russia. RP Yildirim, T (reprint author), Univ Maryland, College Pk, MD 20742 USA. RI yildirim, taner/A-1290-2009 NR 33 TC 22 Z9 22 U1 1 U2 6 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 AUG 1 PY 1998 VL 58 IS 6 BP 3144 EP 3159 DI 10.1103/PhysRevB.58.3144 PG 16 WC Physics, Condensed Matter SC Physics GA 110BN UT WOS:000075359500039 ER PT J AU Stuart, LM Bosted, PE Andivahis, L Lung, A Alster, J Arnold, RG Chang, CC Dietrich, FS Dodge, WR Gearhart, R Gomez, J Griffioen, KA Hicks, RS Hyde-Wright, CE Keppel, C Kuhn, SE Lichtenstadt, J Miskimen, RA Peterson, GA Petratos, GG Rock, SE Rokni, SH Sakumoto, WK Spengos, M Swartz, K Szalata, Z Tao, LH AF Stuart, LM Bosted, PE Andivahis, L Lung, A Alster, J Arnold, RG Chang, CC Dietrich, FS Dodge, WR Gearhart, R Gomez, J Griffioen, KA Hicks, RS Hyde-Wright, CE Keppel, C Kuhn, SE Lichtenstadt, J Miskimen, RA Peterson, GA Petratos, GG Rock, SE Rokni, SH Sakumoto, WK Spengos, M Swartz, K Szalata, Z Tao, LH TI Measurements of the Delta(1232) transition form factor and the ratio sigma(n)/sigma(p) from inelastic electron-proton and electron-deuteron scattering SO PHYSICAL REVIEW D LA English DT Article ID R=SIGMA-L/SIGMA-T; CROSS-SECTIONS; PERTURBATIVE QCD; WAVE-FUNCTIONS; DISTRIBUTION AMPLITUDES; MOMENTUM-TRANSFERS; NUCLEON RESONANCES; 8.83 (GEV/C)(2); EXCITED BARYONS; GLOBAL ANALYSIS AB Measurements of inclusive electron-scattering cross sections using hydrogen and deuterium targets in the region of the Delta(1232) resonance are reported. A global fit tothese new data and previous data in the resonance region is also reported for the proton. Transition form factors have been extracted from the proton cross sections for this experiment over the four-momentum transfer squared range 1.6499.9%) removed from aqueous solution of 1x10(-3) mol L-1 mercury (II) chloride by using a 3 kGy dose. However, a 40 kGy dose is required to remove 96% of lead ions from a 1 x 10(-3) mol L-1 of PbCl2 solution. The effect of dissolved oxygen and carbonate were also investigated. E-beam irradiation of 1 x 10(-3) mol L-1 lead ions complexed with ethylenediamine tetraacetic acid (EDTA) in deoxygenated as well as air-saturated solutions in the absence of ethanol resulted in removal of about 97% of the lead. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Al-Sheikhly, M (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NR 27 TC 30 Z9 35 U1 2 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD AUG PY 1998 VL 53 IS 2 BP 145 EP 150 DI 10.1016/S0969-806X(98)00001-2 PG 6 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 132FD UT WOS:000076618900008 ER PT J AU Harrison, DE Larkin, NK AF Harrison, DE Larkin, NK TI El Nino-Southern Oscillation sea surface temperature and wind anomalies, 1946-1993 SO REVIEWS OF GEOPHYSICS LA English DT Review ID ATMOSPHERE RESPONSE EXPERIMENT; EASTERN EQUATORIAL PACIFIC; TROPICAL PACIFIC; OCEAN MODEL; LEVEL PRESSURE; ENSO SIGNAL; VARIABILITY; EVENTS; EVOLUTION; DYNAMICS AB El Nino-Southern Oscillation (ENSO) periods, which occur irregularly every few years, are a major perturbation of the Earth's climate system that involves large-scale changes in winds, rainfall, sea surface temperature (SST), and surface pressure. In some areas of the world there are disastrous droughts, and in others there is serious flooding. North American weather patterns are also affected. It is important to develop skillful forecasts for ENSO periods. Our goal here is to provide an overview of the global ocean and atmosphere surface changes that typically occur during ENSO periods. Knowledge of these anomaly patterns is needed in order to improve our understanding and forecasts of ENSO. With a global surface data set we describe the statistically significant patterns of SST, surface wind, and surface pressure changes that on average are associated with the 10 post-World War II ENSO periods. We present these average anomaly results as an "ENSO composite." It is useful to identify phases of the typical ENSO and examine the statistically significant elements phase by phase. An ENSO by ENSO period search indicates that about two thirds of these elements occur in 90% or more of the ENSO periods: we define a "Robust ENSO Composite" from these frequently occurring elements and find it to be an Indo-Pacific phenomenon. Limitations in the surface data set make it possible that this study has not identified all the important aspects of ENSO periods; data are very sparse in both space and time over much of the tropics and the southern hemisphere. However, we suggest that any theory or model of ENSO should at least exhibit the features of this robust composite, and is unlikely to able to represent adequately the large-scale environmental impacts of ENSO unless it does so. C1 NOAA, Pacific Marine Environm Lab, Ocean Climate Res Div, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, Ocean Climate Res Div, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. EM harrison@pmel.noaa.gov; larkin@ocean.washington.edu RI Harrison, Don/D-9582-2013 NR 81 TC 126 Z9 133 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD AUG PY 1998 VL 36 IS 3 BP 353 EP 399 DI 10.1029/98RG00715 PG 47 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 126CX UT WOS:000076276300003 ER PT J AU Gillen, G Wight, S Bright, D Herne, T AF Gillen, G Wight, S Bright, D Herne, T TI Quantitative secondary ion mass spectrometry imaging of self-assembled monolayer films for electron beam dose mapping in the environmental scanning electron microscope SO SCANNING LA English DT Article DE environmental scanning electron microscopy; secondary ion mass spectrometry; electron scattering; self-assembled monolayers AB Fluorinated alkanethiol self-assembled monolayers (SAM) films immobilized on gold substrates have been used as electron-sensitive resists to map quantitatively the spatial distribution of the primary electron beam scattering in an environmental scanning electron microscope (ESEM). In this procedure, a series of electron dose standards are prepared by exposing a SAM film to electron bombardment in well-defined regions at different levels of electron dose. Microbeam secondary ion mass spectrometry (SIMS) using Cs+ bombardment is then used to image the F- secondary ion signal from these areas. From the reduction in F- intensity as a function of increasing electron close, a calibration curve is generated that allows conversion of secondary ion signal to electron dose on a pixel-by-pixel basis. Using this calibration, electron dose images can be prepared that quantitatively map the electron scattering distribution in the ESEM with micrometer spatial resolution. The SIMS imaging technique may also be used to explore other aspects of electron-surface interactions in the ESEM. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Gillen, G (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Bldg 222,Room A113, Gaithersburg, MD 20899 USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 USA SN 0161-0457 J9 SCANNING JI Scanning PD AUG PY 1998 VL 20 IS 5 BP 404 EP 409 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 114YN UT WOS:000075636900006 ER PT J AU Bennett, HS AF Bennett, HS TI High dopant and carrier concentration effects in gallium aluminium arsenide: band structure, effective carrier concentrations and mobilities SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Surfaces and Interfaces of Mesoscopic Devices CY DEC 07-12, 1997 CL MAUI, HAWAII SP Arizona State Univ, Off Naval Res ID MINORITY ELECTRON AB The changes in carrier densities of states, band edges, effective carrier concentrations and carrier mobilities due to high dopant and carrier concentration effects in Ga1-yAlyAs are calculated at 300 K for donor densities, N-D, between 10(16) cm(-3) and 10(19) cm(-3) and for acceptor densities, N-A, between 10(16) cm(-3) and 10(20) cm(-3). The mole fraction of AlAs, y, varies between 0.0 and 0.3 in these calculations. Only one quantum mechanical theory is used to treat both sides of the Mott transition in these calculations that give an internally self-consistent description of carrier transport for Ga1-yAlyAs heterostructures. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Bennett, HS (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Bldg 225,Room B344, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECH JI Semicond. Sci. Technol. PD AUG PY 1998 VL 13 IS 8A SU S BP A152 EP A154 DI 10.1088/0268-1242/13/8A/043 PG 3 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA 111MY UT WOS:000075442600043 ER PT J AU Tison, SS AF Tison, SS TI Flow metrology support and digital MFCs SO SOLID STATE TECHNOLOGY LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Tison, SS (reprint author), Millipore Corp, 915 Enterprise Blvd, Allen, TX 77013 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 USA SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD AUG PY 1998 VL 41 IS 8 BP 73 EP + PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 106NN UT WOS:000075135900013 ER PT J AU Persson, BNJ Gadzuk, JW AF Persson, BNJ Gadzuk, JW TI Comments on vibrational dynamics of low-frequency adsorbate motion SO SURFACE SCIENCE LA English DT Letter DE adatoms; atomistic dynamics; metallic surfaces; models of non-equilibrium phenomena; vibration of adsorbed molecules ID HOLE PAIR MECHANISM; BOND BREAKING; TEMPERATURE; SURFACES; DESORPTION; EXCITATION; RELAXATION; ELECTRONS; CU(100); CO AB We discuss the temperature dependence of the electronic damping of adsorbate vibrations, as probed by pump-and-probe and infra-red spectroscopy. In contrast to recent suggestions, we show that the damping is strictly temperature-independent as long as the decay involves the excitation of single electron-hole pairs. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Forschungszentrum Julich, Inst Festkorperphys, D-52425 Julich, Germany. RP Gadzuk, JW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM gadzuk@nist.gov RI Persson, Bo Nils Johan/I-1548-2013 OI Persson, Bo Nils Johan/0000-0003-1535-738X NR 22 TC 32 Z9 32 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 1998 VL 410 IS 2-3 BP L779 EP L782 PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 113AX UT WOS:000075528100009 ER PT J AU Pu, ZX Lord, SJ Kalnay, E AF Pu, ZX Lord, SJ Kalnay, E TI Forecast sensitivity with dropwindsonde data and targeted observations SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID INITIAL CONDITIONS; ANALYSIS SYSTEM; VECTORS; ERRORS AB While forecast models and analysis schemes used in numerical weather prediction have become generally very successful, there is an increasing research interest toward improving forecast skill by adding extra observations either into data sparse areas, or into regions where the verifying Forecast is most sensitive to changes in the initial analysis. The latter approach is referred to as "targeting" observations. In a pioneering experiment of this type, the US Air Force launched dropwindsondes over the relatively data sparse Northeast Pacific Ocean during 1-10 February 1995. The focus of this study is the forecast sensitivity to initial analysis differences, forced by these observations by using both the adjoint method (ADJM) and quasi-inverse linear method (QILM), which are both useful for determining the targeting area where the observations are most needed. We discuss several factors that may affect the results, such as the radius of the mask for the targeted region, the basic flow and the choice of initial differences at the verification time. There are some differences between the adjoint and quasi-inverse linear sensitivity methods. With both sensitivity methods it is possible to find areas where changes in initial conditions lead to changes in the forecast. We find that these two methods are somewhat complementary: the 48-h quasi-inverse linear sensitivity is reliable in pinpointing the region of origin of a forecast difference. This is particularly useful for cases in which the ensemble forecast spread indicates a region of large uncertainty, or when a specific region requires careful forecasts. This region can be isolated with a mask and forecast differences traced back reliably. Another important application for the QILM is to trace back observed 48-h forecast errors. The 48-h adjoint sensitivity, on the other hand, is useful in pointing out ar:as that have maximum impact on the region of interest, but not necessarily the regions that actually led to observed differences, which are indicated more clearly by QILM. At 72 h, the linear assumption made in both methods breaks down, nevertheless the backward integrations are still very useful for pinning down all the areas that would produce changes in the regions of interest (QILM) and the areas that will produce maximum sensitivity (ADJM). Bo:h methods can be useful for adaptive observation systems. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC 20233 USA. RP Pu, ZX (reprint author), NOAA, Environm Modeling Ctr, Space Ctr, Rm 207,5300 Auth Rd, Camp Springs, MD 20746 USA. RI Kalnay, Eugenia/F-4393-2010; OI Kalnay, Eugenia/0000-0002-9984-9906 NR 26 TC 19 Z9 19 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD AUG PY 1998 VL 50 IS 4 BP 391 EP 410 DI 10.1034/j.1600-0870.1998.t01-3-00002.x PG 20 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 122MY UT WOS:000076077100002 ER EF