FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Mathew, M Breuer, E Golomb, G Eidelman, N AF Mathew, M Breuer, E Golomb, G Eidelman, N TI Structural studies of calcium bisacyphosphonates. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 HEBREW UNIV JERUSALEM,JERUSALEM,ISRAEL. NIST,PRC,ADAIIF,GAITHERSBURG,MD 20899. RI Breuer, Eli/E-8382-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2187 EP 2187 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002182 ER PT J AU Fahncke, CR Kelly, JR Antonucci, JM AF Fahncke, CR Kelly, JR Antonucci, JM TI Influence of veneering material on failure of in-ceram FPD analogs SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. USN,SCH DENT,BETHESDA,MD 20814. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2378 EP 2378 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002376 ER PT J AU Mihailova, C Reynolds, BH Chow, LC Naleway, CA AF Mihailova, C Reynolds, BH Chow, LC Naleway, CA TI Fluoride intake effects in bacterial suspensions with and without sucrose. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 ADAHF RI,CHICAGO,IL. ADAHF,PRC,GAITHERSBURG,MD. NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2886 EP 2886 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002881 ER PT J AU Liao, H Takagi, S Chow, LC AF Liao, H Takagi, S Chow, LC TI Effect of a two-solution fluoride mouthrinse on de- and remineralization of enamel lesions in vitro. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2900 EP 2900 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002896 ER PT J AU vonGonten, AS Kelly, JR Antonucci, JM AF vonGonten, AS Kelly, JR Antonucci, JM TI Load-bearing behavior of hydroxyapatite cement bioresorbable fiber mesh craniofacial structures. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 USN,SCH DENT,BETHESDA,MD 20814. NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2935 EP 2935 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002926 ER PT J AU Markovic, M Takagi, S Kim, D Chow, LC AF Markovic, M Takagi, S Kim, D Chow, LC TI Effects of particle size and cement liquid composition on calcium phosphate cement properties. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NIST,ADAHF,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NR 0 TC 5 Z9 9 U1 1 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2942 EP 2942 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002937 ER PT J AU Tung, M Eichmiller, F Gibson, H Ly, A Skrtic, D Schumacher, G AF Tung, M Eichmiller, F Gibson, H Ly, A Skrtic, D Schumacher, G TI Dentin desensitization by in situ formation of calcium phosphate. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2985 EP 2985 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002979 ER PT J AU Ellert, DO Kelly, JR AF Ellert, DO Kelly, JR TI All-ceramic crown failure as a function of occlusal contact location. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 USN,SCH DENT,BETHESDA,MD 20814. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 3030 EP 3030 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68003025 ER PT J AU Kelly, JR Myers, ML DeHoff, PH AF Kelly, JR Myers, ML DeHoff, PH TI Proposed ISO ''bond strength'' test: Residual stress and fracture behavior analysis SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 MCG,SCH DENT,AUGUSTA,GA. NIST,GAITHERSBURG,MD 20899. UNIV N CAROLINA,CHARLOTTE,NC 28223. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 3085 EP 3085 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68003076 ER PT J AU Markovic, M Takagi, S Sieck, B Chow, LC AF Markovic, M Takagi, S Sieck, B Chow, LC TI Characteristics of calcium phosphate cement products in non-pressed specimens. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 3255 EP 3255 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68003245 ER PT J AU Kasahara, S Kimura, K Takagi, S Chow, LC Antonucci, JM AF Kasahara, S Kimura, K Takagi, S Chow, LC Antonucci, JM TI Effect of additives on the properties of a polyacid-calcium phosphate cement. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 TOHOKU UNIV,SENDAI,MIYAGI 980,JAPAN. ADAHF,GAITHERSBURG,MD. NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 3258 EP 3258 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68003254 ER PT J AU Antonopoulou, E Jakobsson, S Mayer, I Swanson, P Borg, B AF Antonopoulou, E Jakobsson, S Mayer, I Swanson, P Borg, B TI In vivo and in vitro effects of 17 alpha,20 beta-dihydroxy-4-pregnene-S-one on testicular androgens in Atlantic salmon, Salmo salar, mature parr SO JOURNAL OF EXPERIMENTAL ZOOLOGY LA English DT Article ID MALE RAINBOW-TROUT; GONADOTROPINS GTH-I; MALE COMMON CARP; SEX STEROIDS; COHO SALMON; 5 ANDROGENS; ONCORHYNCHUS-RHODURUS; SEASONAL-VARIATIONS; CYPRINUS-CARPIO; BALTIC SALMON AB Mature Atlantic salmon (Salmo salar) male parr were implanted in June and August with Silastic capsules filled with the progestin 17 alpha,20 beta-dihydroxy-4-pregnene-3-one (17,20 beta-P) or with empty capsules. Experiments were terminated in September, when natural androgen levels are at their highest. Radioimmunoassay (RIA) showed that treatment raised plasma levels of 17,20 beta-P, whereas the content of gonadotropic hormones (GTH I and II) in the pituitary and plasma levels of the androgens testosterone (T) and 11-ketotestosterone (11-KT) were not influenced. Testicular fragments from mature salmon parr were incubated with different levels of 17,20 beta-P in combination with T or 17 alpha-hydroxy-4-pregnene-3-one as precursors. A very high level of 17,20 beta-P (3,000 ng/ml) suppressed 11-KT production, whereas 3, 30, or 300 ng/ml were without effect. Thus, in these experiments physiological levels of 17,20 beta-P did not suppress androgen 11-KT production or alter pituitary gonadotropin levels, suggesting that some other mechanism is responsible for the natural decline in androgen levels when 17,20 beta-P levels rise at spawning. (C) 1997 Wiley-Liss, Inc. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. RP Antonopoulou, E (reprint author), UNIV STOCKHOLM,DEPT ZOOL,S-10691 STOCKHOLM,SWEDEN. RI Antonopoulou, Efthimia/N-4233-2015; OI Antonopoulou, Efthimia/0000-0003-4565-6962 NR 25 TC 3 Z9 3 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0022-104X J9 J EXP ZOOL JI J. Exp. Zool. PD JAN 1 PY 1997 VL 277 IS 1 BP 66 EP 71 DI 10.1002/(SICI)1097-010X(19970101)277:1<66::AID-JEZ7>3.3.CO;2-V PG 6 WC Zoology SC Zoology GA WE029 UT WOS:A1997WE02900007 ER PT J AU Reppond, KD Babbitt, JK AF Reppond, KD Babbitt, JK TI Gel properties of surimi from various fish species as affected by moisture content SO JOURNAL OF FOOD SCIENCE LA English DT Article DE surimi; moisture; stress; strain; color AB Torsion, punch, and color tests as affected by moisture content were evaluated for surimi from pollock, Pacific herring, arrowtooth flounder, and Pacific whiting. Torsion stress and strain decreased linearly with increased moisture content but strain values were less sensitive to moisture than were stress values. This finding enabled mathematical normalization of torsion stress and strain values rather than adjusting the moisture content of samples prior to testing. Punch test results, while linearly related to moisture content, were not as consistent as torsion test results. The L* and whiteness increased with higher moisture content, but changes in a* and b* values were not consistent for surimi from different species. RP Reppond, KD (reprint author), NATL MARINE FISHERIES SERV,UTILIZAT RES DIV,900 TRIDENT WAY,KODIAK,AK 99615, USA. NR 14 TC 31 Z9 34 U1 0 U2 1 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD JAN-FEB PY 1997 VL 62 IS 1 BP 33 EP 36 DI 10.1111/j.1365-2621.1997.tb04362.x PG 4 WC Food Science & Technology SC Food Science & Technology GA WG856 UT WOS:A1997WG85600007 ER PT J AU Larsen, JC AF Larsen, JC TI Noise reduction in electromagnetic time series to improve detection of seismic-induced signals SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 13th Workshop on Electromagnetic Induction in the Earth CY JUL 12-18, 1996 CL ONUMA INT SEMINAR HOUSE, HOKKAIDO, JAPAN HO ONUMA INT SEMINAR HOUSE ID FIELDS AB A method is described for removing the ionospheric-induced electromagnetic signals from electromagnetic time series in order to improve the detection of signals caused by oceanic, industrial, environmental, or seismic activity. The method is based on transforming the ionospheric-induced signals at a remote site to the local site using smoothly varying transfer functions. This assumes the remote site is relatively free of the non-ionospheric-induced signals. The transformed ionospheric-induced signal is then subtracted from the local time series. The method is tested on data recorded at Hollister and Parkfield that have been provided by F. Morrison. The sites are both near the San Andreas fault in California. Parkfield is used here as the remote site because it will be less contaminated by man-made sources since it is in a remote part of central California. The electric dipoles are approximately 100 m long with electrodes buried about 3 m deep and the magnetic sensors are three buried coils. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Larsen, JC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 13 TC 9 Z9 13 U1 0 U2 2 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1997 VL 49 IS 11-12 BP 1257 EP 1265 PG 9 WC Geosciences, Multidisciplinary SC Geology GA ZE801 UT WOS:000072832300003 ER PT J AU Coffey, HE AF Coffey, HE TI Geomagnetic and solar data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article RP Coffey, HE (reprint author), NOAA,WORLD DATA CTR A SOLAR TERR PHYS,BOULDER,CO 80302, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1997 VL 102 IS A1 BP 213 EP 217 DI 10.1029/96JA03727 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WA692 UT WOS:A1997WA69200020 ER PT J AU Holcombe, TL Warren, JS Taylor, LA Reid, DF Herdendorf, CE AF Holcombe, TL Warren, JS Taylor, LA Reid, DF Herdendorf, CE TI Lakefloor geomorphology of western Lake Erie SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Lake Erie; geomorphology; bathymetry AB Bathymetry of western Lake Erie, exceeding in detail any previous bathymetry, is an early result of a project conducted jointly by the U.S. National Oceanic and Atmospheric Administration and the Canadian Hydrographic Service. This bathymetry utilizes the entire archive of historic hydrographic data assembled since 1903 in the U.S. and Canada. Details of bottom configuration for the shallow (<12 m) western portions of Lake Erie are highlighted using a 1-meter contour interval. The islands and reefs bordering and lying within the western basin have bedrock cores which are erosional remnants of the more resistant upper Silurian and lower Devonian dolomites and limestones. Overdeepened channels between the islands have been sites of postglacial nondeposition, and probably erosion, due to intense wind-driven water circulation through these restricted passages. The Pelee-Lorain Ridge is interpreted as a late Wisconsinan end moraine upon which sand deposits have been concentrated. The point Pelee Ridge is apparently a morainic ridge, capped by sand deposits transported in part by longshore drift converging on Point Pelee. A fan-shaped feature with a surface depth of 10-15 m, which extends to the east of Point Pelee Ridge, may be a former shoreline delta of the Detroit River. This fan-shaped feature may have formed following opening of the Port Huron outlet about 4000 yr bp when the new River was actively eroding its channel and bringing a heavy load of sediment into Lake Erie-although subaqueous deposition of fan sediments is a possible alternate explanation. Sculptured drift-like features interpreted as relict spits extend northwestward and southeastward from the bedrock reefs in the western basin off Locust Point. Channels on the floor of the western Lake Erie basin underlying the main shipping lanes have been excavated by propeller wash where ship traffic increases speed, resulting in resuspension of bottom sediments. Dumpsites for dredge spoils excavated from channels are expressed in the bathymetry by a distinctive hummocky pattern in two areas. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. CANADIAN HYDROG SERV,OTTAWA,ON K1A 0E6,CANADA. OHIO STATE UNIV,DEPT GEOL SCI,COLUMBUS,OH 43210. RP Holcombe, TL (reprint author), NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303, USA. NR 22 TC 5 Z9 6 U1 2 U2 9 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1997 VL 23 IS 2 BP 190 EP 201 PG 12 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA XK458 UT WOS:A1997XK45800007 ER PT J AU Ju, SJ Kucklick, JR Kozlova, T Harvey, HR AF Ju, SJ Kucklick, JR Kozlova, T Harvey, HR TI Lipid accumulation and fatty acid composition during maturation of three pelagic fish species in Lake Baikal SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Lake Baikal; triacylglycerol; fatty acids; sterols; fish; isotopes; lipids ID FLAME IONIZATION DETECTION; L LARVAE; MARINE; ZOOPLANKTON; SEDIMENTS; BACTERIA; GROWTH AB In August and September of 1993, samples were collected from Lake Baikal, Russia to examine the lipid composition of major fauna including phytoplankton, zooplankton, benthic amphipods, and individual year classes of the three major pelagic fish species: Comephorus dybowskii, Comephorus baicalensis, and Coregonus autumnalis migratorius (omul). Total lipid content of all fish samples ranged from 7.8 to 345.1 (mg/g wet weight). Lipid class and fatty acid composition showed significant shifts with increasing age in fish. Lipid content in adult Comephorus baicalensis showed the greatest change, with total lipids increasing front 1.63% of wet weight in juveniles (3 yr.) individuals to over 30% in mature adults (8-10 year). Triacylglycerol was the primary lipid store, increasing from 18 to over 90% of total lipids in several year classes of C, baicalensis with lesser amounts in C. dybowskii and omul. Three fatty acids, the 16:0, 18:1(9), and 22:6 were the major fatty acids in all fish, with significant shifts in distribution attributable to changes in prey items during fish maturity. Cholest-5-en-3 beta-ol (cholesterol) was the dominant sterol in all fish (> 99% of total sterols) and did not show any significant difference among species or with maturity. Carbon and nitrogen isotopic signatures of animal tissue and total lipids varied with age, but provided no set pattern. Results of lipid class and fatty acid composition analysis demonstrated changes in diet and energy storage during maturation of all the three major fish species. C1 UNIV MARYLAND,CTR ENVIRONM & ESTUARINE STUDIES,CHESAPEAKE BIOL LAB,SOLOMONS,MD 20688. NOAA,NMFS,SE FISHERIES SCI CTR,CHARLESTON,SC 29422. RUSSIAN ACAD SCI,INST LIMNOL,IRKUTSK 664003,RUSSIA. RI Ju, Se-Jong/A-9029-2009 NR 33 TC 17 Z9 18 U1 1 U2 6 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1997 VL 23 IS 3 BP 241 EP 253 PG 13 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YB717 UT WOS:A1997YB71700002 ER PT J AU Quinn, FH Croley, TE Kunkel, K Changnon, SJ AF Quinn, FH Croley, TE Kunkel, K Changnon, SJ TI Laurentian Great Lakes hydrology and lake levels under the transposed 1993 Mississippi river flood climate SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Great Lakes; water-levels; hydrology; climate impacts ID IMPACTS; MODEL AB The Laurentian Great Lakes are North America's largest water resource, and include six large water bodies (Lakes Superior Michigan, Huron, Erie, Ontario, and Georgian Bay), Lake St. Clair, and their connecting channels. Because of the relatively small historical variability in system lake levels, there is a need for realistic climate scenarios to develop and test sensitivity and resilience of the system to extreme high lake levels. This is particularly important during the present high lake level regime that has been in place since the late 1960s. In this analysis, we use the unique climate conditions which resulted in the 1993 Mississippi River flooding as an analog to test the sensitivity of Great Lakes hydrology and water levels to a rare but actual climate event. The climate over the Upper Mississippi River basin was computationally shifted corresponding to a conceptual shift of the Great Lakes basin 10 degrees west and 2 degrees south. We applied a system of hydrological models to the daily meteorological time series and determined daily runoff, lake evaporation, and net basin water supplies. The accumulated net basin supplies from May through October 1993 for the 1993 Mississippi River flooding scenario ranged from a 1% decrease for Lake Superior to a large increase for Lake Erie. Water levels for each lake were determined from a hydrologic routing model of the system. Lakes Michigan, Huron, and Erie were most affected. The simulated rise in Lakes Michigan and Huron water levels far exceeded the historical recorded rise with both lakes either approaching or setting record high levels. This scenario demonstrates that an independent anomalous event, beginning with normal lake levels, could result in record high water levels within a 6- to 9-month period. This has not been demonstrated in the historical record or by other simulation studies. C1 MIDWESTERN CLIMATE CTR,CHAMPAIGN,IL 61820. RP Quinn, FH (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. RI Kunkel, Kenneth/C-7280-2015 OI Kunkel, Kenneth/0000-0001-6667-7047 NR 25 TC 4 Z9 4 U1 0 U2 4 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1997 VL 23 IS 3 BP 317 EP 327 PG 11 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YB717 UT WOS:A1997YB71700008 ER PT J AU Tomaszek, JA Gardner, WS Johengen, TH AF Tomaszek, JA Gardner, WS Johengen, TH TI Denitrification in sediments of a Lake Erie coastal wetland (Old Woman Creek, Huron, Ohio, USA) SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE denitrification; sediment; nitrogen; estuary; Lake Erie; Old Woman Creek ID ESTUARINE SEDIMENTS; FRESH-WATER; NITRIFICATION; OXYGEN; ECOSYSTEM AB Denitrification in Old Woman Creek estuary (Lake Erie) sediments was measured by an in vitro N-2-flux method with intact cores and by an in situ chamber method. In both methods, nitrogen gas, the end product of denitrification, was measured directly by gas chromatography. The in situ approach allowed measurement of denitrification directly over short time intervals but its use was limited to shallow depths. Denitrification rates measured with in situ chambers agreed well with those from in vitro intact cores where temperatures in the estuary remained constant. However the two methods could not be accurately compared during the spring where temperature increased rapidly because of the 4-day pre-incubation time needed for sparging for the in vitro method. In vitro denitrification rates ranged from ca 40 to 135 mu mole N-2 m(-2) h(-1) in October 1993 and from 66 to 428 mu mole N-2 m(-2) h(-1) in May and July, 1994. Oxygen consumption rates in these experiments ranged from 0.71 to 3.0 mmole O-2 m(-2) h(-1). Denitrification rates tended to decrease among the flow axis but differences among stations were usually, not significant In situ N-2 accumulation rates ranged from 45 mu mole N(2)m(-2) h(-1) in dark chambers during October 1993 up to apparent values of 2,100 mu mole N-2 m(-2) h(-1) in May 1994, immediately after the water temperature had rapidly increased to 27 degrees C, These calculated values included gas-solubility corrections due to the water-temperature increases. In situ measurements of denitrification rates in transparent chambers were 76-79% higher than rates measured in a similar dark chamber. The results suggest that denitrification is an important sink for-nitrogen in Old Woman Creek estuary and that environmental conditions such as temperature, light, and available substrate affect denitrification rates. C1 Rzeszow Univ Technol, PL-35959 Rzeszow, Poland. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, CILER, Ann Arbor, MI 48109 USA. RP Tomaszek, JA (reprint author), Rzeszow Univ Technol, PL-35959 Rzeszow, Poland. NR 33 TC 20 Z9 20 U1 0 U2 7 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1997 VL 23 IS 4 BP 403 EP 415 PG 13 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YT495 UT WOS:000071611900003 ER PT J AU Davies, A Stroscio, JA Pierce, DT Unguris, J Celotta, RJ AF Davies, A Stroscio, JA Pierce, DT Unguris, J Celotta, RJ TI Observations of alloying in the growth of Cr on Fe(001) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium E on Magnetic Ultrathin Films, Multilayers and Surfaces at the 1996 European-Materials-Research-Society Spring Meeting CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc, Ford Motor Co, Thompson CSF, YKK, Toshiba, SMI, Hitachi, Holm SI DE scanning tunneling microscopy; scanning tunneling spectroscopy; magnetic multilayers; film growth ID MAGNETIC-MOMENTS; THIN-FILMS; FE(100); FE/CR/FE(100); IRON AB Using scanning tunneling microscopy, we observe the alloying of Cr with an Fe(001) substrate for various coverages at two temperatures. At low Cr coverage, the alloy consists of individual Ct impurities surrounded by Fe. Elemental identification is possible using surface states observed via tunneling spectroscopy. The alloy may be the cause of several magnetic anomalies observed in Cr/Fe structures. RP Davies, A (reprint author), NIST, ELECTRON PHYS GRP, GAITHERSBURG, MD 20899 USA. RI Unguris, John/J-3989-2014 NR 20 TC 19 Z9 20 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1997 VL 165 IS 1-3 BP 82 EP 86 DI 10.1016/S0304-8853(96)00477-5 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WF862 UT WOS:A1997WF86200019 ER PT J AU Suenram, RD Lovas, FJ Pereyra, W Fraser, GT Walker, ARH AF Suenram, RD Lovas, FJ Pereyra, W Fraser, GT Walker, ARH TI Rotational spectra, structure, and electric dipole moments of methyl and ethyl tert-butyl ether (MTBE and ETBE) SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID MICROWAVE-SPECTRUM; VIBRATIONAL SPECTROSCOPY; INTERNAL-ROTATION; DIFFRACTION; BEAM AB The rotational spectra of methyl and ethyl tertiary butyl ether (MTBE and ETBE) have been observed and analyzed using a pulsed-molecular-beam Fabry-Perot cavity microwave spectrometer. Both a- and b-type transitions are observed for each compound. Small CH3 internal rotation splittings from the OCH3 group of similar to 1 MHz are observed for MTBE. The high sensitivity of the Fourier transform microwave (FTMW) technique allows observation and analysis of the rotational spectra of all C-13 isotopes and the O-18 isotopic species in natural abundance. For ETBE, the structural analysis indicates that the lowest energy form of the molecule is the completely extended conformer with C-s symmetry. For both compounds, the bulkiness of the t-butyl group causes the COC angle to be 6 degrees to 7 degrees larger than that found in most other ethers. (C) 1997 Academic Press, Inc. RP NIST, OPT TECHNOL DIV, GAITHERSBURG, MD 20899 USA. RI Hight Walker, Angela/C-3373-2009 OI Hight Walker, Angela/0000-0003-1385-0672 NR 20 TC 28 Z9 28 U1 0 U2 3 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 JAN PY 1997 VL 181 IS 1 BP 67 EP 77 DI 10.1006/jmsp.1996.7155 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA WA945 UT WOS:A1997WA94500009 ER PT J AU Christophorou, LG Olthoff, JK Rao, MVVS AF Christophorou, LG Olthoff, JK Rao, MVVS TI Electron interactions with CHF3 SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE attachment; CHF3; cross sections; dissociation; electron scattering; emission; fluoroform; ionization; transport; trifluoromethane ID CYCLOTRON-RESONANCE PLASMA; ABSOLUTE CROSS-SECTIONS; EMISSION-SPECTRA; CF3 RADICALS; VACUUM ULTRAVIOLET; PHOTOELECTRON-SPECTRA; POLYATOMIC-MOLECULES; IMPACT DISSOCIATION; NEGATIVE-IONS; UV EMISSION AB In this paper we assess and synthesize the available information on the cross sections and the rate coefficients for collisional interactions of trifluoromethane (CHF3) with electrons in an effort to build a database on electronic and ionic collision processes that will aid the understanding of the behavior of CHF3 in its use in manufacturing semiconductor devices and other applications. The limited data on the total and partial electron impact ionization cross sections, total and partial cross sections for electron impact dissociation of CHF3 into neutral species, electron-impact induced line and continuous light emission from CHF3, negative ion states of CHF3, and the energetics of ionization, dissociation, and attachment are summarized and discussed. Besides some recent unpublished measurements of the total electron scattering cross section below 20 eV, to our knowledge no measurements are available of the cross sections of any of the electron scattering processes (elastic, momentum, vibrational, inelastic, etc.) or the electron transport, attachment, and ionization coefficients. While the available information is meager, the synthesis of the existing knowledge and the background information provided in the paper can be helpful for modeling plasma reactors. Clearly, more measurements and calculations are needed of the cross sections for virtually all fundamental electron impact processes for this plasma processing gas. Measurements of the transport, attachment, and ionization coefficients over wide ranges of the density reduced electric field are also needed. (C) 1997 American Institute of Physics and American Chemical Society. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Christophorou, LG (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 73 TC 87 Z9 88 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD JAN-FEB PY 1997 VL 26 IS 1 BP 1 EP 15 PG 15 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA WF658 UT WOS:A1997WF65800001 ER PT J AU Xu, LH Lovas, FJ AF Xu, LH Lovas, FJ TI Microwave spectra of molecules of astrophysical interest .24. Methanol (CH3OH and (CH3OH)-C-13) SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE internal rotation (or torsion); interstellar molecule; isotopomer; line strength; methanol; microwave and millimeter-wave spectra; radio astronomy; rotational transitions ID SUBMILLIMETER-WAVE SPECTRUM; GROUND TORSIONAL STATE; MILLIMETER-WAVE; ROTATIONAL TRANSITIONS; C-13 METHANOL; ADDITIONAL MEASUREMENTS; METHYL-ALCOHOL; GLOBAL FIT; LINE AB The available microwave and millimeter-wave spectra of methanol, CH3OH, and its most abundant isotopomer, (CH3OH)-C-13, are critically reviewed and supplemented with spectral frequency calculations derived from rotation-internal rotation analyses. For both species, global analyses of the torsional ground state, v(t) = 0, and the first excited torsional state, v(t) = 1, have been carried out in which all observed spectral lines are reproduced to within their measurement uncertainties. References are given for all data included. The primary objective of this review is to provide radio astronomers with complete spectral coverage of rotational transitions from 500 MHz to 1 THz, including the lower state energy and line strength for each transition, over the range in rotational quantum number J from 0 to 26. (C) 1997 American Institute of Physics and American Chemical Society. C1 NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899. RP Xu, LH (reprint author), UNIV NEW BRUNSWICK,DEPT PHYS SCI,ST JOHNS,NB E2L 4L5,CANADA. RI Xu, Li-Hong/J-5095-2015 NR 40 TC 74 Z9 75 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD JAN-FEB PY 1997 VL 26 IS 1 BP 17 EP 156 PG 140 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA WF658 UT WOS:A1997WF65800002 ER PT J AU Winton, M AF Winton, M TI The damping effect of bottom topography on internal decadal-scale oscillations of the thermohaline circulation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID NORTH-ATLANTIC; INTERDECADAL VARIABILITY; BOUNDARY-CONDITIONS; MODEL; TEMPERATURE AB By comparing the response of flat and bowl-shaped basins to fixed heat fluxes of various magnitudes,it is determined that coastal topography has a considerable damping influence upon internal decadal oscillations of the thermohaline circulation. It is proposed that this is because the adjustment of baroclinic currents to the no-normal-flow boundary condition at weakly stratified coasts is aided in the topography case by the generation of substantial barotropic flow. RP Winton, M (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 13 TC 35 Z9 36 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JAN PY 1997 VL 27 IS 1 BP 203 EP 208 DI 10.1175/1520-0485(1997)027<0203:TDEOBT>2.0.CO;2 PG 6 WC Oceanography SC Oceanography GA WG321 UT WOS:A1997WG32100015 ER PT J AU Cromer, S Hambright, P Grodkowski, J Neta, P AF Cromer, S. Hambright, P. Grodkowski, J. Neta, P. TI Tetrabenzoporphyrins: Metal Incorporation and Exchange Kinetics, Ligational Equilibria and Pulse Radiolysis Studies SO JOURNAL OF PORPHYRINS AND PHTHALOCYANINES LA English DT Article DE tetrabenzoporphyrins; metal incorporation; kinetic studies; solution chemistry; formation constants AB The solution chemistry of tetrabenzoporphyrin (TBP) and several of its metal derivatives were compared with that of the corresponding octaethylporphyrins. Kinetic studies were done on zinc and cadmium ion incorporation and the exchange reactions of cadmium porphyrins with zinc. Formation constants of Cd(II), Cu(II), VO(IV), Ni(II), Zn(II) and Mg(II) porphyrins with pyridine were determined for both compounds. The spectra of the radical cations of Ni(II), Mg(II) and H(2)-TBP were obtained, as well as that of the radical anion of Mg(II) TBP. Aside from the new Ni(I) TBP, no long-lived intermediates, as noted with other porphyrins, were observed upon reduction of the tetrabenzoporphyrins. The low basicity and rigidity of the tetrabenzoporphyrin nucleus may explain many of its relative reactivity properties. (C) 1997 by John Wiley & Sons, Ltd. C1 [Cromer, S.; Hambright, P.] Howard Univ, Dept Chem, Washington, DC 20059 USA. [Grodkowski, J.; Neta, P.] Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Hambright, P (reprint author), Howard Univ, Dept Chem, Washington, DC 20059 USA. FU NASA through Center for the Study of Extraterrestrial Atmospheres and the radiation chemical studies at NIST [NAGW-2950] FX The synthetic, kinetic and equilibrium work at Howard University was supported by NASA NAGW-2950 through the Center for the Study of Extraterrestrial Atmospheres and the radiation chemical studies at NIST by the Division of Chemical Sciences, Office of Basic Energy Sciences, US Department of Energy. NR 61 TC 10 Z9 10 U1 4 U2 8 PU WORLD SCI PUBL CO INC PI HACKENSACK PA 27 WARREN ST, STE 401-402, HACKENSACK, NJ 07601 USA SN 1088-4246 J9 J PORPHYR PHTHALOCYA JI J. Porphyr. Phthalocyanines PY 1997 VL 1 IS 1 BP 45 EP 54 DI 10.1002/(SICI)1099-1409(199701)1:1<45::AID-JPP3>3.0.CO;2-D PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA V17EA UT WOS:000207919300004 ER PT J AU Lindstrom, RM Becker, DA Langland, JK Greenberg, RR AF Lindstrom, RM Becker, DA Langland, JK Greenberg, RR TI The NIST rapid irradiation and counting system SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1996 CL SEOUL, SOUTH KOREA AB Apparatus is being developed for short irradiation and rapid counting at the NIST Reactor, optimized for accurate neutron activation analysis via activation products ranging in half-life from about 500 ms to 500 s. This facility is designed to irradiate a sample either in a well-thermalized neutron flux at 3.10(13)n.cm(-2).s(-1), or in a higher flux with a larger fast and epithermal component. The design transfer time for a l-ml rabbit is 500 ms, measured to 10 ms precision. Timing information for both irradiation and counting will be transferred automatically to the activation analysis workstation computer. The gamma-ray spectrometer system is selected and tuned for accurate measurement at high and varying counting rates, using loss-free counting (LFC) technology. A detailed calibration and characterization of this system has been performed. Accurate measurement requires that attention be paid to the systematic and random errors to which LFC is subject, but this requirement is minor compared to the advantages of undistorted spectral shape, the ability to solve the decay equations exactly, and the wider useful range of counting rates in the spectrometer system. RP Lindstrom, RM (reprint author), NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JAN PY 1997 VL 215 IS 1 BP 47 EP 50 DI 10.1007/BF02109876 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV460 UT WOS:A1997XV46000008 ER PT J AU Paul, RL Lindstrom, RM Heald, AE AF Paul, RL Lindstrom, RM Heald, AE TI Cold neutron prompt gamma-ray activation analysis at NIST - Recent developments SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1996 CL SEOUL, SOUTH KOREA ID HYDROGEN AB The cold neutron capture prompt gamma-ray activation analysis (CNPGAA) spectrometer located in the Cold Neutron Research Facility (CNRF) at NIST has proven useful for the analysis of hydrogen and other elements in a wide variety of materials. Modifications of the instrument and the CNRF have resulted in improved measurement capabilities for PGAA. The addition of an atmosphere-controlled sample chamber and Compton suppression have reduced gamma-ray background and increased signal-to-noise ratio. More recent revisions are expected to yield still further improvement in analytical capabilities. Replacement of the D2O ice cold source with a liquid H-2 moderator is expected to yield a 5-10 fold increase in neutron capture rate, and improved neutron and gamma-ray shielding will result in further reduction of the background Other modifications to the instrument allow easier sample mounting and mon: precise positioning of samples in the neutron beam. Significant improvements in detection limits and analytical accuracy are expected. C1 NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP Paul, RL (reprint author), NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 21 TC 49 Z9 51 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JAN PY 1997 VL 215 IS 1 BP 63 EP 68 DI 10.1007/BF02109879 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV460 UT WOS:A1997XV46000011 ER PT J AU ChenMayer, HH Sharov, VA Mildner, DFR Downing, RG Paul, RL Lindstrom, RM Zeissler, CJ Xiao, QF AF ChenMayer, HH Sharov, VA Mildner, DFR Downing, RG Paul, RL Lindstrom, RM Zeissler, CJ Xiao, QF TI Capillary neutron optics for prompt-gamma activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1996 CL SEOUL, SOUTH KOREA ID LENS AB A neutron lens has been constructed to focus cold neutrons from the exit of a Ni-58 neutron guide, which delivers a beam to the Prompt-Gamma Activation Analysis (PGAA) station at the MST Cold Neutron Research Facility. The lens compresses a neutron beam of cross section 50 mm x 45 mm onto a focal spot of diameter 0.53 mm (fwhm) with an average gain of 80 in neutron current density. PGAA measurements have been performed to demonstrate the enhanced sensitivity and detection limits for various elements and the spatial resolution in one transverse dimension. For the two test particles (a gadolinium glass bead and cadmium metal of sizes less than 0.5 mm), the gain in the gamma-count rate with the lens is a factor of 60, and the detection limit is improved by a factor of 20. The system can be used for two-dimensional mapping of samples on a sub-millimeter scale to complement other analytical techniques such as neutron depth profiling (NDP). C1 XRAY OPT SYST INC,ALBANY,NY 12205. RP ChenMayer, HH (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 12 TC 10 Z9 10 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JAN PY 1997 VL 215 IS 1 BP 141 EP 145 DI 10.1007/BF02109890 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV460 UT WOS:A1997XV46000022 ER PT J AU Then, SS Geurink, FDP Bode, P Lindstrom, RM AF Then, SS Geurink, FDP Bode, P Lindstrom, RM TI A pulse generator simulating Ge-detector signals for dead-time and pile-up correction in gamma-ray spectrometry in INAA without distortion of the detector spectrum SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1995 CL SEOUL, SOUTH KOREA SP Korea Inst Geol Min & Mat, Int Atom Energy Agcy, Korean Soc Anal Sci AB Commercially available pulse generators for use in gamma-ray spectroscopy to correct for dead-time and pile-up losses share the problem that the fall-time of the output pulses does not match the fall-time of the detector pulse. Upon pulse shaping in the main amplifier the pulser's signals result in a considerable undershoot of the amplifier's output signal, which cannot be restored by the P/Z network. As a result, peaks in the gamma-ray spectrum are broadened. Moreover, amplitude stability of the generators is often poorer than the overall gain stability of the spectrometer. To overcome these problems a special pulse generator has been developed at the Interfaculty Reactor Institute, which simulates Ge-detector signals. It generates pulses with a constant frequency of 25 Hz using a crystal oscillator controlled mercury relay. The stability of the generator's amplitude and frequency is extremely high and the peak-shapes in the gamma-ray spectrum are not distorted. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Then, SS (reprint author), DELFT UNIV TECHNOL,INTERFAC REACTOR INST,MEKELWEG 15,NL-2629 JB DELFT,NETHERLANDS. NR 2 TC 21 Z9 21 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JAN PY 1997 VL 215 IS 2 BP 249 EP 252 DI 10.1007/BF02034473 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV463 UT WOS:A1997XV46300014 ER PT J AU Tandon, GP Kim, RY Dutton, RE AF Tandon, GP Kim, RY Dutton, RE TI Failure modes in unidirectional composites under transverse loading SO JOURNAL OF REINFORCED PLASTICS AND COMPOSITES LA English DT Article; Proceedings Paper CT 10th Technical Conference of the American-Society-for-Composites CY OCT 18-20, 1995 CL SANTA MONICA, CA SP Amer Soc Composites AB This paper reports on our attempts to demonstrate potential failure modes under combined thermal and transverse loading of unidirectional composites and to validate the predictions of an analytical model through careful design and testing of composite specimens. Several fiber/matrix combinations are being considered with appropriate variations of the fiber-matrix interfacial bond strength and processing conditions. The interfacial bond strength is reduced in one set of specimens by applying a release agent to the surface of the fiber prior to its incorporation in the matrix. Curing is done both at room and at elevated temperature to account for thermal residual stresses induced from the mismatch in the coefficients of thermal expansion of the constituents. The experimental technique including specimen preparation, test procedures and detection of the sequence of failure events is described. The correlation between the experimental and analytical results is fairly reasonable. C1 UNIV DAYTON,RES INST,DAYTON,OH 45469. ADTECH SYST RES INC,DAYTON,OH 45432. NIST,WRIGHT LAB,WRIGHT PATTERSON AFB,OH 45433. NR 11 TC 7 Z9 7 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0731-6844 J9 J REINF PLAST COMP JI J. Reinf. Plast. Compos. PY 1997 VL 16 IS 1 BP 33 EP 49 PG 17 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA WD097 UT WOS:A1997WD09700004 ER PT J AU Wang, ZL vanHeerden, D Josell, D Shapiro, AJ AF Wang, ZL vanHeerden, D Josell, D Shapiro, AJ TI Energy-filtered high-resolution electron microscopy for quantitative solid state structure determination SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Al/Ti; composition-sensitive imaging; electron energy-loss spectroscopy; energy-filtering; high-resolution electron microscopy; Ni/Ti ID SPECTROSCOPY AB Energy-filtered (or selected) electron imaging is one of the future directions of high-resolution electron microscopy (HREM). In this paper, the characteristics and applications of energy-selected electron imaging at high-resolution for structure determinations are illustrated. It is shown that image contrast can be dramatically improved with the use of an energy filter. High-resolution chemical-sensitive imaging using ionization-loss electrons is demonstrated in studies of Ni/Ti and Al/Ti multilayer thin films. It is also shown that the spatial resolution of energy-selected ionization edge electron images is dominated by the signal-to-noise ratio. Experimental parameters which may be selected to improve the signal-to-noise ratio are discussed. RP Wang, ZL (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 20 TC 7 Z9 7 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 1 EP 13 DI 10.6028/jres.102.002 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500001 PM 27805125 ER PT J AU Wang, Z Chiang, CK Chuang, TJ AF Wang, Z Chiang, CK Chuang, TJ TI Optimum design of a ceramic tensile creep specimen using a finite element method SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ceramics; finite element method; optimum design; power-law creep; specimen design; stress analysis; stress relaxation ID FLEXURAL CREEP; COMPOSITES; PARAMETERS; BEHAVIOR AB An optimization procedure for designing a ceramic tensile creep specimen to minimize stress concentration is carried out using a finite element method. The effect of pin loading and the specimen geometry are considered in the stress distribution calculations. A growing contact zone between the pin and the specimen has been incorporated into the problem solution scheme as the load is increased to its full value. The optimization procedures are performed for the specimen, and all design variables including pinhole location and pinhole diameter, head width, neck radius, and gauge length are determined based on a set of constraints imposed on the problem. In addition, for the purpose of assessing the possibility of delayed failure outside the gage section, power-law creep in the tensile specimen is considered in the analysis. Using a particular grade of advanced ceramics as an example, it is found that if the specimen is not designed properly, significant creep deformation and stress redistribution may occur in the head of the specimen resulting in undesirable (delayed) head failure of the specimen during the creep test. RP Wang, Z (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 24 TC 12 Z9 13 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 JAN-FEB PY 1997 VL 102 IS 1 BP 15 EP 28 DI 10.6028/jres.102.003 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500002 PM 27805126 ER PT J AU Wiejaczka, JA Goodrich, LF AF Wiejaczka, JA Goodrich, LF TI Interlaboratory comparison on high-temperature superconductor critical-current measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE critical current; degradation; high temperature superconductors; interlaboratory comparison; repeatability; standard method; variability AB An extensive interlaboratory comparison was conducted on high temperature superconductor (HTS) critical-current measurements. This study was part of an international cooperative effort through the Versailles Project on Advanced Materials and Standards (VAMAS). The study involved six U.S, laboratories that are recognized leaders in the field of HTS. This paper includes the complete results from this comparison of critical-current measurements on Ag-sheathed Bi2Sr2Ca2Cu3O10-x (2223) tapes. The effects of sample characteristics, specimen mounting, measurement technique, and specimen damage were studied. The future development of standard HTS measurement method is also discussed. Most of the evolution of this emerging technology has occurred in improvement of the performance of the conductors. The successful completion of this interlaboratory comparison is an important milestone in the evolution of HTS technology and marks a level of maturity that the technology has reached. RP Wiejaczka, JA (reprint author), NATL INST STAND & TECHNOL, 325 BROADWAY, BOULDER, CO 80303 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 29 EP 52 DI 10.6028/jres.102.004 PG 24 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500003 PM 27805127 ER PT J AU McKenney, K Hoskins, J Tian, JX Reddy, P AF McKenney, K Hoskins, J Tian, JX Reddy, P TI DNA molecules as Standard Reference Materials .1. Development of DNA identification sequences and human mitochondrial DNA reference sequences SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE deoxyribonucleic acid (DNA) sequencing; DNA identification; genetic codes; genetic information; molecular tags; standard reference materials ID CLONING; VECTORS; SYSTEM; AID AB This paper describes the design, construction and characterization of two DNA molecules that function as prototype Standard Reference Materials for use in the determination of DNA sequences. The first prototype reference DNA molecule was constructed to function as a true reference DNA sequence encoding the human mitochondrial hypervariable region 1. The second DNA molecule was designed to be a molecular DNA ''tag'' for use in the identification of DNA Standard Reference Materials. DNA molecules were chemically and enzymatically synthesized, cloned in molecular cloning vectors and sequenced using manual and automated fluorescent DNA sequencing methods. The sequence of the cloned human mitochondrial HV1 DNA shows six base pair differences from the original published DNA sequence. The molecular DNA tag sequence uses the universal genetic code with one letter amino acid abbreviations to spell the words ''NIST DNA STANDARD REFERENCE MATERIAL.'' The need and utility of an expanded molecular code to uniquely identify DNA molecules is discussed. The use of these DNA molecules in the development of DNA Standard Reference Materials is also described. C1 UNIV MARYLAND, MARYLAND BIOTECHNOL INST, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. RP McKenney, K (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 53 EP 62 DI 10.6028/jres.102.005 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500004 PM 27805128 ER PT J AU Kinard, JR Lipe, TE Childers, CB AF Kinard, JR Lipe, TE Childers, CB TI Extension of the NIST AC-DC difference calibration service for current to 100 kHz SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ac current; ac-dc difference; current calibrations; current shunts; thermal converter; thermal current converter; thermoelement AB The NIST calibration service for ac-dc difference of thermal current converters relies on multijunction thermal converters as the primary standards, and various thermal converters and thermoelements (TEs) as the reference and working standards. Calibrations are performed by comparing the ac-dc difference of a customer's thermal current converter to the ac-dc difference of a NIST standard current converter. Typical artifacts accepted for calibration include single-junction thermoelements. multijunction thermal converters, and transfer shunts for use with TEs. This paper describes the standards on which the calibration service is based and the results of the study to characterize the NIST standards over the extended frequency range from 50 kHz to 100 kHz at currents from 1 mA to 20 A. The general method for the frequency extension at high frequency involves the use of thermoelements in the 5 mA range, with small frequency dependence, as the starting point for build-up and build-down chains to cover the whole range from 1 mA to 20 A. RP Kinard, JR (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 7 TC 9 Z9 9 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 75 EP 83 DI 10.6028/jres.102.007 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500006 PM 27805130 ER PT J AU Caskey, GW Phillips, SD Borchardt, BR AF Caskey, GW Phillips, SD Borchardt, BR TI Results of the NIST national ball plate round robin SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ball plate; CMM; coordinate measuring machine; coordinate metrology; round robin AB This report examines the results of the ball plate round robin administered by NIST. The round robin was part of an effort to assess the current state of industry practices for measurements made using coordinate measuring machines. Measurements of a two-dimensional ball plate (240 mm by 240 mm) on 41 coordinate measuring machines were collected and analyzed. Typically, the deviations of the reported X and Y coordinates from the calibrated values were within +/- 5 mu m, with some coordinate deviations exceeding 20.0 mu m. One of the most significant observations from these data was that over 75 % of the participants failed to correctly estimate their measurement error on one or more of the ball plate spheres. RP Caskey, GW (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 85 EP 93 DI 10.6028/jres.102.008 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500007 PM 27805131 ER PT J AU Weetall, HH AF Weetall, HH TI The Sixth International Meeting on Chemical Sensors - Gaithersburg, MD July 22-25, 1996 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP Weetall, HH (reprint author), NATL INST STAND & TECHNOL, DIV BIOTECHNOL, GAITHERSBURG, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 1997 VL 102 IS 1 BP 95 EP 105 DI 10.6028/jres.102.009 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WT035 UT WOS:A1997WT03500008 PM 27805132 ER PT J AU Arkles, B Berry, DH Figge, LK Composto, RJ Chiou, T Colazzo, H Wallace, WE AF Arkles, B Berry, DH Figge, LK Composto, RJ Chiou, T Colazzo, H Wallace, WE TI Staged development of modified silicon dioxide films SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 8th International Workshop on Glasses and Ceramics from Gels CY SEP 18-22, 1995 CL ALGARVE, PORTUGAL DE beta-chloroethylsilsesquioxane; beta-chloroethyltrichlorosilane; spin-on glass; thermal conversion; dielectric films; silicon dioxide AB The hydrolytic generation of SiO2 films from chlorosilanes or alkoxysilanes is interrupted by incorporating labile organic groups which stop SiO2 formation at a processable prepolymer stage. The monomers for the prepolymer have electron withdrawing substituents in the beta-position. The organic groups are removed from the prepolymer at low temperature, extruding ethylene. The formation of SiO2 proceeds by intramolecular condensation of the electronegative substituents which are now in a hydrolytically unstable bond with silicon and hydroxyl groups or ambient moisture. Films of the prepolymer spun onto silicon wafers are converted into uniform SiO2-rich films at temperatures between 150-400 degrees C. C1 UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104. UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Arkles, B (reprint author), GELEST INC,612 WILLIAM LEIGH DR,TULLYTOWN,PA 19007, USA. OI Arkles, Barry/0000-0003-4580-2579; Berry, Donald/0000-0001-6732-3726 NR 7 TC 17 Z9 17 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PY 1997 VL 8 IS 1-3 BP 465 EP 469 DI 10.1007/BF02436883 PG 5 WC Materials Science, Ceramics SC Materials Science GA WQ334 UT WOS:A1997WQ33400074 ER PT J AU Bentz, DP AF Bentz, DP TI Three-dimensional computer simulation of portland cement hydration and microstructure development SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID IMPEDANCE SPECTROSCOPY; AUTOGENOUS SHRINKAGE; STRENGTH DEVELOPMENT; PASTE; MODELS; PERCOLATION; DIFFUSIVITY; KINETICS; GROWTH AB A three-dimensional computer model for the simulation of portland cement hydration and microstructure development has been developed, Starting with a measured particle-size distribution and a set of scanning electron microscopy images, a three-dimensional representation of a cement of interest is reconstructed, matching the phase volume fractions and surface-area fractions of the two-dimensional. images, A set of cellular-automata rules is then applied to the starting microstructure to model the chemical reactions for all of the major phases during the evolving hydration process, The dissolution cycles used in the model have been calibrated to real time using a single set of parameters for true cements at three different water-to-cement ratios, Based on this calibration, there is excellent agreement between the model predictions and experimental measurements for degree of hydration, heat release, and chemical shrinkage, The degree-of-hydration predictions have been successfully applied to predicting the compressive strength development of mortar cubes for the two cements. The effects of temperature have been examined by performing hydration experiments at 15 degrees, 25 degrees, and 35 degrees C and applying a maturity-type relationship to determine a single degree of hydration-equivalent time curve that can be compared to the model predictions, Finally, the computer model has been further extended to simulate hydration under sealed conditions, where self-desiccation limits the achievable hydration. RP Bentz, DP (reprint author), NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, GAITHERSBURG, MD 20899 USA. NR 67 TC 234 Z9 241 U1 6 U2 65 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1997 VL 80 IS 1 BP 3 EP 21 PG 19 WC Materials Science, Ceramics SC Materials Science GA WF896 UT WOS:A1997WF89600001 ER PT J AU Choi, JH Kim, DY Hockey, BJ Wiederhorn, SM Handwerker, CA Blendell, JE Carter, WC Roosen, AR AF Choi, JH Kim, DY Hockey, BJ Wiederhorn, SM Handwerker, CA Blendell, JE Carter, WC Roosen, AR TI Equilibrium shape of internal cavities in sapphire SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ION-IMPLANTED SAPPHIRE; CRACK-LIKE FLAWS; SURFACES; ALUMINA; VOIDS AB The equilibrium shape of internal canities in sapphire was determined through the study of submicrometer internal cavities in single crystals, Cavities formed from indentation cracks during annealing at 1600 degrees C, Equilibrium could be reached only for cavities that were smaller than approximate to 100 nm, Excessive times mere required to achieve equilibrium for cavities larger than approximate to 1 mu m. Five equilibrium facet planes were observed to bound the cavities: the basal (C) {0001}, rhombohedral (R) {<(1)over bar 012>}, prismatic (A) {<1(2)over bar 10>}, pyramidal (P) {<11(2)over bar 3>}, and structural rhombohedral (S) {<10(1)over bar 1>}. The surface energies for these planes relative to the surface energy of the basal plane mere gamma(R) = 1.05, gamma(A) = 1.12, gamma(P) = 1.06, gamma(S) = 1.07, These energies mere compared with the most recent theoretical calculations of the surface energy of sapphire, The comparison was not within experimental scatter for any of the surfaces, with the measured relative surface energies being lower than the calculated energies, Although the prismatic (M) {<10(1)over bar 0>} planes are predicted to be a low-energy surface, facets of this orientation mere not observed. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Choi, JH (reprint author), SEOUL NATL UNIV,DEPT INORGAN MAT ENGN,SEOUL 151742,SOUTH KOREA. RI Carter, W/K-2406-2012 NR 20 TC 111 Z9 112 U1 5 U2 20 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1997 VL 80 IS 1 BP 62 EP 68 DI 10.1111/j.1151-2916.1997.tb02791.x PG 7 WC Materials Science, Ceramics SC Materials Science GA WF896 UT WOS:A1997WF89600007 ER PT J AU Gross, BD AF Gross, BD TI The effect of compressibility on barotropic and baroclinic instability SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article AB The effect of compressibility an two-dimensional barotropic and baroclinic growth rates is examined by means of a linearized nonhydrostatic compressible model. It is shown that the growth rates are diminished when compressibility is included because perturbation internal energy represents a sink of basic-state kinetic energy when work is done to compress the medium. Nonlinear simulations provided by compressible and incompressible versions of the ZETA model show that the solutions are nearly identical, but the compressible solution develops more slowly than the incompressible one, consistent with the linear analysis. RP Gross, BD (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,FORRESTAL CAMPUS,US ROUTE 1,PRINCETON,NJ 08542, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JAN 1 PY 1997 VL 54 IS 1 BP 24 EP 31 DI 10.1175/1520-0469(1997)054<0024:TEOCOB>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD277 UT WOS:A1997WD27700003 ER PT J AU Trapp, RJ DaviesJones, R AF Trapp, RJ DaviesJones, R TI Tornadogenesis with and without a dynamic pipe effect SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SUPERCELL THUNDERSTORM; NUMERICAL-SIMULATION; BOUNDARY-LAYER; ROTATION; VORTEX; MODEL; VORTICITY; TORNADOES; RADAR AB A dynamic pipe effect (DPE) has been used previously to explain the descent from aloft of tornadic vortex signatures (TVSs), and presumably embryonic tornadoes, prior to the near-ground spinup of the tornado. But for many tornadoes the TVS appears to form simultaneously over a depth spanning the lowest few kilometers. A numerical model is used to determine the conditions under which a tornado is or is not preceded by a DPE. The model governs two-dimensional, axisymmetric, forced convection inside a closed, impermeable cylinder that rotates at a constant rate. Motion relative to the tank is initiated by a time-independent buoyancy field that is varied in a suite of experiments. The need for a DPE in vortex development in the model is shown to depend on trajectories of high-angular-momentum air, driven at least initially by this buoyancy field. Indeed, when buoyancy is confined primarily to midlevels, convergence at the foot of the vertical axis is weak initially, parcels with high angular momentum approach closest to the axis first at midlevels, and the Vortex forms aloft (mode I). As the vortex intensifies and becomes cyclostrophically balanced, its central pressure drops and lateral motion into its core is inhibited. The resultant vertical pressure gradient and radial convergence below the vortex core increase, allowing parcels to approach the axis-and thus affording vortex spinup-at progressively lower levels. This process is the DPE. When significant buoyancy is present at low levels, air parcels that nearly conserve angular momentum are transported close to the axis over a relatively deep layer inclusive of the lower levels. The vortex in this case forms at low and midlevels al the same time, precluding a need for a DPE (mode II). A simple analytical model is used to illustrate the two modes of vortex formation, and to generalize the conclusions drawn from the numerical model. A time-dependent version of the Burgers-Rott vortex due to Rott demonstrates vortex formation without a DPE. In this exact solution of the Navier-Stokes equations, horizontal convergence and angular momentum are independent of height, and the meridional flow is steady. A simple analytical solution for the DPE has not been found. However, it can be shown qualitatively that a vortex that develops aloft, because either the large-scale convergence or the ambient angular momentum increases with height, induces below itself an axial jet and increased radial inflow at low levels. RP Trapp, RJ (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 46 TC 46 Z9 46 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JAN 1 PY 1997 VL 54 IS 1 BP 113 EP 133 DI 10.1175/1520-0469(1997)054<0113:TWAWAD>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD277 UT WOS:A1997WD27700009 ER PT J AU Laake, JL Calambokidis, J Osmek, SD Rugh, DJ AF Laake, JL Calambokidis, J Osmek, SD Rugh, DJ TI Probability of detecting harbor porpoise from aerial surveys: Estimating g(0) SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE aerial surveys; dive behavior; g(0) estimation; harbor porpoise; line transect sampling; Phocoena phocoena; visibility bias ID PHOCOENA-PHOCOENA; VISIBILITY BIAS; ABUNDANCE ESTIMATION; CALIFORNIA; WASHINGTON; OREGON AB Harbor porpoise (Phocoena phocoena), and most other cetaceans, spend a significant proportion of time submerged, and are undetectable from the air. Abundance estimates based on line transect sampling may be severely biased by assuming that all porpoise near the line are detected [g(0) = 1]. By tracking groups of harbor porpoise from land, we estimated the proportion of time harbor porpoise spent at the surface and the probability that aerial observers detected groups within 200 m of the transect line. Two teams on land, equipped with electronic theodolites, tracked harbor porpoise while surveys were conducted from an aircraft equipped with side-bubble windows and a belly window. During 7 days, 33 hours of observation were made in a high-density area for harbor porpoise near Orcas Island, Washington. We monitored 7 different harbor porpoise groups from 15 to 66 minutes each. The average proportion of time at or near the surface was 0.231 (SE = 0.032). From a selected sample of 164 land-based sightings of harbor porpoise groups, 50 (30.5%) were observed from the aircraft. For our aerial line transect surveys of harbor porpoise conducted by experienced observers, (g) over cap(0) = 0.292 (SE = 0.107). However, for the inexperienced observers, (g) over cap(0) was 0.079 (SE = 0.046), which demonstrates the importance of experience and training. RP Laake, JL (reprint author), NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 32 TC 66 Z9 71 U1 0 U2 7 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JAN PY 1997 VL 61 IS 1 BP 63 EP 75 DI 10.2307/3802415 PG 13 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA WL788 UT WOS:A1997WL78800007 ER PT J AU Salit, ML Griesmeyer, JM AF Salit, ML Griesmeyer, JM TI System-ready behaviors for integration SO LABORATORY ROBOTICS AND AUTOMATION LA English DT Article AB A generic eel of behaviors is described for devices so that they can be reliably and readily used as subsystems in an automated systems environment. The automated systems discussed here are constructed of multiple functional subsystems, arrayed hierarchically under a system supervisor. Such systems are typical of those popularly deployed in the chemical laboratory. These systems have had mixed success in the analytical chemistry arena, largely because they are difficult to construct-integrate-and because it is difficult to engineer them to operate reliably. The behaviors described in this article are intended to make devices more simple to integrate as subsystems into a system and to ensure they will operate reliably in that role. (C) 1997 John Wiley & Sons, Inc. C1 SANDIA NATL LABS,INTELLIGENT SYST & ROBOT CTR,ALBUQUERQUE,NM 87185. RP Salit, ML (reprint author), NIST,CTR ANALYT CHEM,CHEM SCI & TECHNOL LAB,CHEM BLDG B154,GAITHERSBURG,MD 20899, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-7533 J9 LAB ROBOTICS AUTOMAT JI Lab. Robot. Autom. PY 1997 VL 9 IS 3 BP 113 EP 118 DI 10.1002/(SICI)1098-2728(1997)9:3<113::AID-LRA3>3.0.CO;2-3 PG 6 WC Automation & Control Systems; Chemistry, Analytical; Robotics SC Automation & Control Systems; Chemistry; Robotics GA XK568 UT WOS:A1997XK56800002 ER PT B AU Xie, YF AF Xie, YF BE Biegler, LT Coleman, TF Conn, AR Santosa, FN TI Atmospheric data assimilation based on the reduced Hessian successive quadratic programming algorithm SO LARGE-SCALE OPTIMIZATION WITH APPLICATIONS, PT I: OPTIMIZATION IN INVERSE PROBLEMS AND DESIGN SE IMA VOLUMES IN MATHEMATICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT Workshop on Large-Scale Optimization CY JUL 10-28, 1995 CL UNIV MINNESOTA, INST MATH & ITS APPLICAT, MINNEAPOLIS, MN SP Inst Math & Its Applicat HO UNIV MINNESOTA, INST MATH & ITS APPLICAT DE atmospheric data assimilation; constrained optimization; four dimensional; variational analysis; reduced Hessian successive quadratic programming algorithms AB Mesoscale weather forecasting cannot be improved until a better data assimilation is obtained. Four dimensional variational analysis (4DVAR) provides the most elegant framework for data assimilation. One of the most critical issues of applying 4DVAR to weather prediction is how efficiently these variational problems can be solved. We introduce the reduced Hessian SQP algorithm for these problems and obtain an adjoint reduced Hessian SQP method, which is quadratically convergent since the exact reduced Hessian is used. C1 NOAA, ERL, FSL, Boulder, CO 80303 USA. RP Xie, YF (reprint author), NOAA, ERL, FSL, 325 Broadway, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-98286-8 J9 IMA V MATH PY 1997 VL 92 BP 195 EP 204 PG 10 WC Mathematics, Applied SC Mathematics GA BK97B UT WOS:000073966200011 ER PT B AU Damazo, BN Gee, AE Slocum, AH AF Damazo, BN Gee, AE Slocum, AH BE Ford, DG Postlethwaite, SR TI Friction drive for ultra-precision machine tools: interface compliance-based model SO LASER METROLOGY AND MACHINE PERFORMANCE III LA English DT Proceedings Paper CT 3rd International Conference on Laser Metrology and Machine Performance (LAMDAMAP 97) CY 1997 CL UNIV HUDDERSFIELD, HUDDERSFIELD, ENGLAND SP Natl Phys Lab, Inst Elect Engn, Renishaw Plc, Taylor Hobson, Cincinnati Milacron, AGEMA, ITP, Asquith Butler, MTTA, AWE, Holroyd Machine Tools & Qual Today HO UNIV HUDDERSFIELD AB The roller/bar friction-drive is an example of a high-precision rectilinear actuator. The roller/bar friction drive offers control advantages of low backlash and dead-band due to elastic averaging within the Hertzian contact region. It also offers simplicity, both of initial design and extensibility to longer ranges (as high as of the order of meters) while incurring only marginal effort/cost in design and implementation. Furthermore, the roller/bar friction drive has not been employed extensively, this is probably due to uncertainty over issues of limitations on drive-force, transmission-gain and topology and cleanliness of the drive-bar/interface. To address uncertainties involved in the characteristics of such a drive, analysis was undertaken with the objective of providing design-tools for a new generation of machine tools. A model was developed to predict the behavior of the contact interface using Hertzian contact stress theory. Other goals of the study included methodologies for determining static and dynamic stiffness as a function of load and input dynamics as represented by the drive-force frequency. The model is described and comparisons with experimental results are made. C1 Natl Inst Stand & Technol, Automated Prod Div, Gaithersburg, MD 20899 USA. RP Damazo, BN (reprint author), Natl Inst Stand & Technol, Automated Prod Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON S04 2AA, HANTS, ENGLAND BN 1-85312-536-9 PY 1997 BP 273 EP 282 PG 10 WC Engineering, Manufacturing; Engineering, Mechanical; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BK72P UT WOS:000073221900024 ER PT B AU Soons, JA AF Soons, JA BE Ford, DG Postlethwaite, SR TI Error analysis of a hexapod machine tool SO LASER METROLOGY AND MACHINE PERFORMANCE III LA English DT Proceedings Paper CT 3rd International Conference on Laser Metrology and Machine Performance (LAMDAMAP 97) CY 1997 CL UNIV HUDDERSFIELD, HUDDERSFIELD, ENGLAND SP Natl Phys Lab, Inst Elect Engn, Renishaw Plc, Taylor Hobson, Cincinnati Milacron, AGEMA, ITP, Asquith Butler, MTTA, AWE, Holroyd Machine Tools & Qual Today HO UNIV HUDDERSFIELD AB This paper describes the measurement and analysis of the quasi-static errors of a prototype hexapod milling machine at the National Institute of Standards and Technology (NIST). Emphasis is placed on a) the identification and definition of the parametric errors, b) the development of an analytical model to describe how these parametric errors affect errors in the position and orientation of the tool, c) identification of the most important parametric errors and their potential impact on performance, d) comparison of hexapod error characteristics to those of conventional machine tools, e) description of the techniques used to measure and estimate the hexapod errors, and f) application of the various concepts to model the geometrical and thermal errors of the NIST hexapod, including measurement results. C1 Natl Inst Stand & Technol, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. RP Soons, JA (reprint author), Natl Inst Stand & Technol, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON S04 2AA, HANTS, ENGLAND BN 1-85312-536-9 PY 1997 BP 347 EP 358 PG 12 WC Engineering, Manufacturing; Engineering, Mechanical; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BK72P UT WOS:000073221900031 ER PT J AU Xu, HHK Jahanmir, S Ives, LK AF Xu, HHK Jahanmir, S Ives, LK TI Effect of grinding on strength of tetragonal zirconia and zirconia-toughened alumina SO MACHINING SCIENCE AND TECHNOLOGY LA English DT Article ID PARTIALLY-STABILIZED ZIRCONIA; SHORT-CRACK TOUGHNESS; MATERIAL-REMOVAL; SILICON-NITRIDE; CERIA-ZIRCONIA; MARTENSITIC-TRANSFORMATION; DAMAGE; METASTABILITY; POLYCRYSTALS; INDENTATION AB The effect of grinding-induced damage,on the strength of a yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and a zirconia-toughened alumina (ZTA) was investigated. The four-point flexure test was used to measure fracture strength as a function of grinding conditions. Flexure bar specimens were prepared by surface grinding transverse to the tensile stress direction in flexure testing. Two series of grinding experiments were performed. In the first series, four wheels with diamond particle sizes ranging from 25 to 180 mu m were used to grind specimens at a fixed depth of cut. The strength of the Y-TZP decreased slightly with increasing diamond particle size. For ZTA the strength loss was increased as diamond particle size was increased. In the second series, one grinding wheel with a diamond particle size of 180 mu m was used to grind specimens at a depth of cut per pass ranging from 2.5 to 100 mu m. The Y-TZP showed a slight decrease in strength when the depth of cut was increased. However, for ZTA, the strength first decreased, then increased with increasing depth of cut. The grinding-induced subsurface damage, observed by a bonded-interface sectioning technique, consisted of cracks for ZTA, but no subsurface cracks could be found for Y-TZP. The effect of machining damage on the strength of ZTA was explained using the observed subsurface cracks and residual stresses that were measured using an indentation technique. C1 NIST, Amer Dent Assoc, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), NIST, Amer Dent Assoc, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 33 TC 45 Z9 46 U1 1 U2 13 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1091-0344 J9 MACH SCI TECHNOL JI Mach. Sci. Technol. PY 1997 VL 1 IS 1 BP 49 EP 66 DI 10.1080/10940349708945637 PG 18 WC Engineering, Manufacturing; Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 168QL UT WOS:000078703700005 ER PT J AU Nelson, L Xu, HHK Danyluk, S Jahanmir, S AF Nelson, L Xu, HHK Danyluk, S Jahanmir, S TI Subsurface damage in grinding titanium aluminide SO MACHINING SCIENCE AND TECHNOLOGY LA English DT Article ID TECHNOLOGY AB This paper reports on an experimental investigation of grinding-induced subsurface damage in gamma titanium aluminide (gamma-TiAl). Grinding was carried out with resin-bond diamond wheels having the same concentration but different grit sizes, and with a vitreous-bond silicon carbide wheel using various depths of cut. The extent of the subsurface damage was determined by a bonded interface technique and optical microscopy. The grinding-induced damage beneath the ground surfaces was found to consist of plastic deformation and microcracks. The severity and depth of the subsurface damage zone increased with an increase in the abrasive grit size and the depth of cut. Microcracks were observed when grinding was performed with the silicon carbide wheel at a depth of cut of 100 and 125 mu m. C1 Georgia Inst Technol, Atlanta, GA 30332 USA. Amer Dent Assoc, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Nelson, L (reprint author), Georgia Inst Technol, Atlanta, GA 30332 USA. NR 10 TC 7 Z9 7 U1 0 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1091-0344 J9 MACH SCI TECHNOL JI Mach. Sci. Technol. PY 1997 VL 1 IS 2 BP 289 EP 297 DI 10.1080/10940349708945653 PG 9 WC Engineering, Manufacturing; Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 168QM UT WOS:000078703800009 ER PT S AU Gilliland, GL AF Gilliland, GL BE Carter, CW Sweet, RM TI Biological macromolecule crystallization database SO MACROMOLECULAR CRYSTALLOGRAPHY, PT B SE Methods in Enzymology LA English DT Review ID PROTEIN CRYSTALLIZATION; CRYSTAL-GROWTH C1 NATL INST STAND & TECHNOL, ROCKVILLE, MD 20850 USA. RP Gilliland, GL (reprint author), MARYLAND BIOTECHNOL INST, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. NR 22 TC 3 Z9 4 U1 0 U2 0 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 BN 0-12-182178-1 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 277 BP 546 EP 556 DI 10.1016/S0076-6879(97)77030-7 PG 11 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BJ57S UT WOS:A1997BJ57S00028 PM 18488324 ER PT J AU Benmouna, M Briber, R Hammouda, B AF Benmouna, M Briber, R Hammouda, B TI Polymer blends, copolymers and networks. Scattering properties and phase behavior SO MACROMOLECULAR THEORY AND SIMULATIONS LA English DT Article ID ELASTIC LIGHT-SCATTERING; ANGLE NEUTRON-SCATTERING; DYNAMIC SCATTERING; DIBLOCK COPOLYMER; STIFF POLYMERS; SPIN-ECHO; CONCENTRATION FLUCTUATION; TERNARY MIXTURES; CROSS-LINKS; POLYSTYRENE AB The phase behavior and scattering properties of polymer blends, copolymers and networks in solution and in bulk art: examined. The theoretical framework used here is based upon the extension of the random phase approximation to polymers proposed by de Gennes and its application to chains with various architectures. The case of blends containing stiff chains is considered and the effect of nematic interaction on the phase behavior and scattering properties is discussed. The compressibility problem is reviewed in connection with the free volume theory models. The coupling between density and composition fluctuations is examined together with the effects of pressure on the structural and thermodynamic properties of blends. The dynamics of copolymers are also examined in the light of the new developments both from the theoretical and experimental fronts. The extent to which the chain architecture affects phase behavior, static scattering and dynamic behavior is discussed. A particular emphasis is put on the case of cyclic homopolymers and copolymers. Free chains in a network and crosslinked blends are also a subject of particular interest in this paper. The interplay between macrophase and microphase transitions due to the crosslinks and the electrostatic forces for charged polymers is also considered. De Gennes' analogy betwen the elastic restoring forces in the network and the Coulomb forces in the dielectric medium is generalized by including the screening phenomenon. This generalization is required in order to account for the experimental observations in the low momentum transfer range. Following Briber et at, it is argued that die new screening length can be related to the initial fluctuations at the temperature of crosslinking. C1 MAX PLANCK INST POLYMER RES,D-55021 MAINZ,GERMANY. UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. RP Benmouna, M (reprint author), NIST,BLDG 235,E151,GAITHERSBURG,MD 20899, USA. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 94 TC 7 Z9 7 U1 0 U2 7 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 1022-1344 J9 MACROMOL THEOR SIMUL JI Macromol. Theory Simul. PD JAN PY 1997 VL 6 IS 1 BP 197 EP 235 DI 10.1002/mats.1997.040060114 PG 39 WC Polymer Science SC Polymer Science GA WC132 UT WOS:A1997WC13200014 ER PT B AU Hart, L Baillie, C Edwards, J Govett, M Henderson, T AF Hart, L Baillie, C Edwards, J Govett, M Henderson, T BE Hoffmann, GR Kreitz, N TI Experience developing and running real-time weather models on parallel machines SO MAKING ITS MARK LA English DT Proceedings Paper CT 7th ECMWF Workshop on the Use of Parallel Processors in Meteorology CY NOV 02-06, 1996 CL READING, ENGLAND SP European Ctr Medium Range Weather Forecasts AB The Forecast Systems Laboratory (FSL) has been running a numerical weather prediction (NWP) model in real-time on a distributed memory massively parallel processor (MPP) since March 1995. Currently three NWP models run in real-time on FSL's Intel Paragon: the Rapid Update Cycle (RUC), a development version of RUC known as the Mesoscale Analysis and Prediction System (MAPS), and Colorado State University's Regional Atmospheric Modeling System (RAMS). During this process, FSL has developed a package known as the Scalable Modeling System to aid in the portable parallelization of NWP models. In this paper we describe the lessons that Ive have learned in developing and running portable parallel NWP models. C1 NOAA, Forecast Syst Lab, Boulder, CO 80303 USA. RP Hart, L (reprint author), NOAA, Forecast Syst Lab, 325 Broadway, Boulder, CO 80303 USA. RI Govett, Mark/H-2363-2015 NR 0 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3350-7 PY 1997 BP 326 EP 331 PG 2 WC Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BM17V UT WOS:000077914900025 ER PT B AU Rancic, M Baillie, CF AF Rancic, M Baillie, CF BE Hoffmann, GR Kreitz, N TI Cubic and octagonal spherical grids on MPPs SO MAKING ITS MARK LA English DT Proceedings Paper CT 7th ECMWF Workshop on the Use of Parallel Processors in Meteorology CY NOV 02-06, 1996 CL READING, ENGLAND SP European Ctr Medium Range Weather Forecasts AB A global shallow water grid-point model, that uses quasi-uniform cubic and octagonal spherical grids, has been run on several different parallel machines. The paper presents the performance results on both parallel vector and massively parallel processors. One of the results is that the model executes about three time faster on the MPP Gray T3D than on the parallel vector Gray C90. C1 Univ Corp Atmospher Res, Natl Ctr Environm Predist, Camp Springs, MD 20748 USA. RP Rancic, M (reprint author), Univ Corp Atmospher Res, Natl Ctr Environm Predist, Camp Springs, MD 20748 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3350-7 PY 1997 BP 332 EP 341 PG 2 WC Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BM17V UT WOS:000077914900026 ER PT B AU Edwards, JP Snook, JS Christidis, Z AF Edwards, JP Snook, JS Christidis, Z BE Hoffmann, GR Kreitz, N TI Use of a parallel mesoscale model in support of the 1996 Summer Olympic Games SO MAKING ITS MARK LA English DT Proceedings Paper CT 7th ECMWF Workshop on the Use of Parallel Processors in Meteorology CY NOV 02-06, 1996 CL READING, ENGLAND SP European Ctr Medium Range Weather Forecasts AB The United States National Weather Service (NWS) implemented the Olympic Weather Support System (OWSS) to meet the weather forecast and warning needs of the 1996 Summer Olympic Games. This paper describes the implementation of the local forecast component of that system, the SMS-RAMS parallel model, comprising the FSL developed Scalable Modeling System and the Colorado State University developed Regional Atmospheric Modeling System. C1 NOAA, Forecast Syst Lab REFS1, Boulder, CO 80303 USA. RP Edwards, JP (reprint author), NOAA, Forecast Syst Lab REFS1, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3350-7 PY 1997 BP 342 EP 353 PG 2 WC Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BM17V UT WOS:000077914900027 ER PT B AU Moore, E Cradick, J Weiss, M AF Moore, E Cradick, J Weiss, M BE Harmon, D TI Compatible resource uses and emerging use conflicts in national marine sanctuaries SO MAKING PROTECTION WORK: PROCEEDINGS OF THE 9TH CONFERENCE ON RESEARCH AND RESOURCE MANAGEMENT IN PARKS AND ON PUBLIC LANDS LA English DT Proceedings Paper CT 9th Conference on Research and Resource Management in Parks and on Public Lands - Making Protection Work CY MAR 17-21, 1997 CL ALBUQUERQUE, NM SP George Wright Soc, US Natl Park Serv, US Geol Survey, Biol Resources Div, E Natl Park & Monument Assoc, US Natl Park Serv, Park Planning & Special Studies Div C1 NOAA, SRD, Silver Spring, MD 20910 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU GEORGE WRIGHT SOCIETY, INC. PI HANCOCK PA PO BOX 65, HANCOCK, MI 49930-0065 USA PY 1997 BP 7 EP 10 PG 4 WC Environmental Studies; Public Administration; Sociology SC Environmental Sciences & Ecology; Public Administration; Sociology GA BN83M UT WOS:000083133100002 ER PT J AU Jefferson, TA Curry, BE Leatherwood, S Powell, JA AF Jefferson, TA Curry, BE Leatherwood, S Powell, JA TI Dolphins and porpoises of West Africa: A review of records (Cetacea: Delphinidae, Phocoenidae) SO MAMMALIA LA English DT Review ID STENELLA-CLYMENE; 1ST RECORD; ATLANTIC; KUKENTHAL AB A review indicates that nineteen species of dolphins and porpoises (cetacean families Delphinidae and Phocoenidae) occur in West African waters (from the Strait of Gibraltar to the Congo River). In addition, two other cold temperate species reach their southern limit at the northern border of the area. For each species, distribution records in West African waters are reviewed. A key to dolphins and porpoises of West Africa, based on external appearance, is presented to aid in identification. C1 OCEAN PK CORP,OCEAN PK CONSERVAT FDN,ABERDEEN,HONG KONG. NOAA,NMES,SW FISHERIES SCI CTR,LA JOLLA,CA 92038. UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND. RP Jefferson, TA (reprint author), OCEAN PK CORP,IUCN,CETACEAN SPECIALIST GRP,ABERDEEN,HONG KONG. NR 99 TC 16 Z9 20 U1 1 U2 2 PU MUSEUM NAT HIST NATURELLE PI PARIS PA 55 RUE DE BUFFON, 75005 PARIS, FRANCE SN 0025-1461 J9 MAMMALIA JI Mammalia PY 1997 VL 61 IS 1 BP 87 EP 108 DI 10.1515/mamm.1997.61.1.87 PG 22 WC Zoology SC Zoology GA XA396 UT WOS:A1997XA39600009 ER PT J AU Bundy, MH Paffenhofer, GA AF Bundy, MH Paffenhofer, GA TI The innervation of the setae on the appendages of the nauplius of Eucalanus pileatus Giesbrecht SO MARINE AND FRESHWATER BEHAVIOUR AND PHYSIOLOGY LA English DT Article DE calanoid copepod; sensory morphology; chemoreceptor; mechanoreceptor; confocal microscopy ID MARINE COPEPODS; FIRST ANTENNAE; FINE-STRUCTURE; 1ST ANTENNAE; MECHANORECEPTORS; MICROSCOPY; CALANOIDA; SENSILLA; CRAYFISH C1 Skidaway Inst Oceanog, Savannah, GA 31411 USA. RP Bundy, MH (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 29 TC 3 Z9 4 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0091-181X J9 MAR FRESHW BEHAV PHY JI Mar. Freshw. Behav. Physiol. PY 1997 VL 30 IS 3 BP 195 EP 207 PG 13 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA YM167 UT WOS:000071036500003 ER PT J AU Begg, GA Hopper, GA AF Begg, GA Hopper, GA TI Feeding patterns of school mackerel (Scomberomorus queenslandicus) and spotted mackerel (S-munroi) in Queensland east-coast waters SO MARINE AND FRESHWATER RESEARCH LA English DT Article DE niche; overlap; prey; migrations; fisheries; management ID SPANISH MACKERELS; NICHE OVERLAP; KING MACKEREL; SCOMBRIDAE; FISHERY AB Seasonal feeding and dietary overlap patterns between school mackerel (Scomberomorus queenslandicus) and spotted mackerel (S. munroi) in Queensland east-coast waters, Australia (16 degrees S to 28 degrees S), were examined from June 1992 to January 1995. School mackerel have a more diverse diet than spotted mackerel, with the diets of both species being dominated by pilchards, anchovies and herring. Dietary overlap between school and spotted mackerel appeared to be limited owing to temporal and spatial separation. The seasonal availability of certain prey items may play an important role in attracting mackerel into inshore waters where they become accessible to the commercial and recreational fisheries. C1 Univ Queensland, Dept Zool, St Lucia, Qld 4072, Australia. RP Begg, GA (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 32 TC 10 Z9 10 U1 0 U2 2 PU C S I R O PUBLICATIONS PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA SN 1323-1650 J9 MAR FRESHWATER RES JI Mar. Freshw. Res. PY 1997 VL 48 IS 7 BP 565 EP 571 DI 10.1071/MF97064 PG 7 WC Fisheries; Limnology; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA YU774 UT WOS:000071752800002 ER PT J AU Monaco, ME Ulanowicz, RE AF Monaco, ME Ulanowicz, RE TI Comparative ecosystem trophic structure of three US mid-Atlantic estuaries SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE network analysis; food webs; carbon flows; estuaries ID DELAWARE ESTUARY; CHESAPEAKE BAY AB Quantitative networks of trophic exchanges offer the potential to compare food webs from neighboring ecosystems in order to ascertain whether large differences and similarities exist in trophic structure and function. Network analysis was invoked to compare the exchanges of carbon in 3 mid-Atlantic estuaries on the eastern U.S. coast: the Narragansett, Delaware, and Chesapeake Bays. Narragansett Bay exhibited the highest average annual rate of net primary production, followed by Delaware and Chesapeake Bays. Taken in combination, the analyses of cycling structures (magnitude of flows, average carbon cycle lengths), organization of carbon flows, system production:biomass ratios, and harvest rates all indicated that the Delaware and Chesapeake Bay ecosystems are more stressed than that of Narragansett Bay. To differentiate between the former two, a combination of measures of system efficiency, cycling structure, and food web connectivity was employed. The results indicated that Delaware Bay is currently less impacted and has potentially more ability to mitigate perturbations to its food web than does Chesapeake Bay. Overall, network analysis proved to be a suitable methodology for making inter-estuarine ecosystem comparisons, and for providing useful insights to natural resource managers in the assessment of estuarine trophic structure and status. C1 NOAA, NOARC 1, Silver Spring, MD 20910 USA. Univ Maryland, Chesapeake Biol Lab, Solomons, MD 20688 USA. RP Monaco, ME (reprint author), NOAA, NOARC 1, 1305 East West Highway, Silver Spring, MD 20910 USA. EM mark.monaco@noaa.gov RI Ulanowicz, Robert/G-1021-2013 NR 61 TC 122 Z9 125 U1 0 U2 19 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 161 BP 239 EP 254 DI 10.3354/meps161239 PG 16 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA YX982 UT WOS:000072100100022 ER PT J AU Seitzinger, SP Sanders, RW AF Seitzinger, SP Sanders, RW TI Contribution of dissolved organic nitrogen from rivers to estuarine eutrophication SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE dissolved organic nitrogen; nitrogen; estuaries; rivers; microbial processes; eutrophication ID COMBINED AMINO-ACIDS; NORTH-ATLANTIC OCEAN; N-15 TRACER METHOD; BACTERIAL PRODUCTION; CHESAPEAKE BAY; HETEROTROPHIC ECOSYSTEM; NUTRIENT LIMITATION; COUNTING BACTERIA; DELAWARE ESTUARY; MARINE-BACTERIA AB The bioavailibility of dissolved organic nitrogen (DON) in river water entering estuaries was examined for the Delaware and Hudson Rivers, USA. Water collected from above the salinity intrusion zone of each river was filtered, brought to a salinity of 15 ppt, and inoculated with estuarine bacteria. Bacterial production rates (8 to 26 x 10(5) cells ml(-1) d(-1)) during the initial 2 d in these experiments were within the range measured in these and other estuaries, indicating that riverine dissolved organic matter can contribute to production of estuarine bacteria. Average DON concentrations decreased by 40 to 72% within the 10 to 15 d time course of the experiments; the decreases in DON were accounted for by increases in microbial biomass plus remineralization to inorganic nitrogen. The time scale over which DON was utilized suggests that in estuaries with residence times on the order of weeks to months, such as Delaware Bay, river inputs of the biologically available portion of DON are first utilized within the estuary. In contrast, in estuaries with residences times of less than a week, such as New York Bay, a portion of the biologically available DON may be utilized first within the estuary, with the remainder exported and utilized in continental shelf waters. The large proportion of the DON that was biologically available in these experiments, coupled with the knowledge that inputs of organic nitrogen can account for 20 to 90% of the total nitrogen loading to estuaries, suggests that organic nitrogen inputs may contribute more to estuarine and shelf eutrophication than was previously suspected. These experiments demonstrate that dissolved inorganic nitrogen (DIN) inputs underestimate, and total nitrogen inputs likely overestimate, the inputs of biologically available N to estuaries. In order to develop a 'biologically available nitrogen budget' for an ecosystem, DIN inputs, plus that portion of the organic N that is biologically available must be quantified. C1 Acad Nat Sci Philadelphia, Div Environm Res, Philadelphia, PA 19103 USA. RP Seitzinger, SP (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, Rutgers NOAA CMER Program, 71 Dudley Rd, New Brunswick, NJ 08901 USA. EM sybil@imcs.rutgers.edu RI Sanders, Robert/C-1116-2011 OI Sanders, Robert/0000-0001-7264-1059 NR 81 TC 185 Z9 195 U1 6 U2 51 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 159 BP 1 EP 12 DI 10.3354/meps159001 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA YQ193 UT WOS:000071358700001 ER PT J AU Terrados, J Duarte, CM Kenworthy, WJ AF Terrados, J Duarte, CM Kenworthy, WJ TI Is the apical growth of Cymodocea nodosa dependent on clonal integration? SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE clonal integration; growth; seagrasses; Cymodocea nodosa ID HERB GLECHOMA-HEDERACEA; FRAGARIA-CHILOENSIS; PHYSIOLOGICAL INTEGRATION; SEAGRASS COLONIZATION; UCRIA ASCHERSON; RAMETS; DYNAMICS AB The importance of clonal integration for the production of biomass by the apical meristem of Cymodocea nodosa (Ucria) Ascherson was tested in situ by experimental manipulation. The production of new biomass by the apical meristem of a horizontal rhizome, as well as the leaf growth of the remaining shoots, was greatly reduced when the horizontal rhizome was severed, even when up to 11 shoots were left connected to the apical meristem of the rhizome. In contrast, the elimination of up to 8 shoots after the 3 apical shoots on a horizontal rhizome did not affect the production of biomass by the apical meristem. These results show that growth at the apical meristem of a C, nodosa rhizome depends on resources translocated along the rhizome from shoots situated further than 50 cm from the rhizome apex and that all the individual shoots (ramets) in a C. nodosa clone should be considered as one unit. Clonal integration does not depend on the presence of living shoots along the translocation route but is dependent on the integrity of the horizontal rhizome. C1 NOAA, NATL MARINE FISHERIES SERV, SE FISHERIES SCI CTR, BEAUFORT LAB, BEAUFORT, NC 28516 USA. RP Terrados, J (reprint author), CSIC, CTR ESTUDIOS AVANZADOS BLANES, CAMI SANTA BARBARA S-N, E-17300 BLANES, GIRONA, SPAIN. RI Terrados, Jorge/B-1062-2008; Duarte, Carlos M/A-7670-2013 OI Terrados, Jorge/0000-0002-0921-721X; Duarte, Carlos M/0000-0002-1213-1361 NR 24 TC 30 Z9 30 U1 0 U2 2 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 158 BP 103 EP 110 DI 10.3354/meps158103 PG 8 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA YK607 UT WOS:A1997YK60700009 ER PT J AU Lohrenz, SE Fahnenstiel, GL Redalje, DG Lang, GA Chen, XG Dagg, MJ AF Lohrenz, SE Fahnenstiel, GL Redalje, DG Lang, GA Chen, XG Dagg, MJ TI Variations in primary production of northern Gulf of Mexico continental shelf waters linked to nutrient inputs from the Mississippi River SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE primary production; nutrients; phytoplankton; continental shelf; hypoxia; Mississippi River; Gulf of Mexico; eutrophication ID OF-MEXICO; COASTAL WATERS; CHESAPEAKE BAY; PHYTOPLANKTON; LOUISIANA; PLUME; NITROGEN; EUTROPHICATION; MACROBENTHOS; TRANSPORT AB Increases in nutrient concentrations in the Mississippi River over the past 35 yr have led to speculation that primary production of organic carbon has been elevated as a result of increased nutrient fluxes that have occurred in the northern Gulf of Mexico coastal ecosystem. However, studies thus far have not provided direct demonstration of temporal relationships between measured primary production in continental shelf waters and river-borne nutrient fluxes. This investigation compared temporal variations in primary production with associated annual and interannual changes in river-borne nutrient inputs. Primary production in shelf waters near the river delta were found to be significantly correlated with nitrate (NO3-) + nitrite (NO2-) concentrations and fluxes over a 6 yr period from 1988 to 1994. Although light limitation was probably an important factor during winter months, a positive correlation was demonstrated between river inputs of NO3-+NO2- and primary production for data collected from other times of the year. Peak nutrient inputs generally occurred in the spring. The magnitude of the riverborne NO3-+NO2- inputs averaged 106% of estimated nitrogen requirements for phytoplankton in the river-impacted region, considerably greater than in Amazon shelf waters, which have been less subject to anthropogenic nutrient increases. The possibility exists that further increases in anthropogenic nutrients in the Mississippi River could lead to higher and more widespread primary production, and this may intensify and extend the depletion of oxygen that has already been observed in the Louisiana shelf ecosystem. However, such a prediction is difficult because relationships between increasing nutrient inputs and primary production are unlikely to be Linear, and a complete understanding of processes intermediate between primary production of organic matter and oxygen depletion in bottom waters on the Louisiana shelf is still lacking. C1 NOAA, GREAT LAKES ENVIRONM RES LAB, MUSKEGON, MI 49441 USA. NOAA, GREAT LAKES ENVIRONM RES LAB, ANN ARBOR, MI 48105 USA. LOUISIANA UNIV MARINE CONSORTIUM, CHAUVIN, LA 70344 USA. RP Lohrenz, SE (reprint author), UNIV SO MISSISSIPPI, INST MARINE SCI, STENNIS SPACE CTR, MS 39529 USA. OI Lohrenz, Steven/0000-0003-3811-2975 NR 48 TC 120 Z9 125 U1 3 U2 33 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 155 BP 45 EP 54 DI 10.3354/meps155045 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XY395 UT WOS:A1997XY39500004 ER PT J AU Vetter, RD Lynn, EA AF Vetter, RD Lynn, EA TI Bathymetric demography, enzyme activity patterns, and bioenergetics of deep-living scorpaenid fishes (genera Sebastes and Sebastolobus): paradigms revisited SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE metabolic adaptation; deep-sea fishes; oxygen minimum zone; feeding rates; lactate dehydrogenase; citrate synthase; malate dehydrogenase ID DEHYDROGENASE HOMOLOGS; LACTATE-DEHYDROGENASES; HYDROSTATIC-PRESSURE; OXYGEN-CONSUMPTION; DIFFERENT DEPTHS; MUSCLE; ADAPTATIONS; METABOLISM; SIZE; CONSEQUENCES AB Previous metabolic studies of scorpaenid fishes have measured inter-and intra-specific differences in physiological and biochemical capacities in fishes living al different depths. Small sample sizes and undocumented provenance of the samples studied have not allowed a full examination of the environmental basis for metabolic adaptation. The objective of this study was to determine the bathymetric demography of 22 scorpaenid fishes of the genera Sebastes and Sebastolobus, and to examine inter-and intra-specific changes in metabolic capacity in 4 of them (Sebastes goodei, Sebastes diploproa, Sebastolobus alascanus and Sebastolobus altivelis) representative of different environmental conditions. We attempted to collect samples that spanned the full depth and size ranges of each species. We examined changes in metabolic capacity as it was affected by size, depth of occurrence, and the existence of an oxygen minimum zone (OMZ) centered at 800 m. Lactate dehydrogenase (LDH) was measured as an indicator of glycolytic capacity. Citrate synthase (CS), a Krebs cycle enzyme, was measured as an indicator of aerobic capacity. Malate dehydrogenase (MDH), an enzyme which helps maintain redox balance between the mitochondrion and cytosol, was also used as an indicator of aerobic capacity. When normalized to a common size, S. goodei, S. diploproa, S. alascanus and S. altivelis displayed an inter-specific pattern of declining metabolic activity with depth of occurrence. Intra-specific size scaling of glycolytic capacity (LDH) was positive in the shallow-living S. goodei. However, no scaling occurred in S. diploproa and S. alascanus, and negative scaling of glycolytic activity occurred in the deep-living S. altivelis. MDH did not scale in S. goodei and S. diploproa but was negative in the 2 deeper-living Sebastolobus species. CS activity scaled negatively in S. goodei, S. alascanus, and S. altivelis, but the deep-water specialist, S. altivelis, had the steepest slope. S. altivelis was the only species where similar-sized individuals could be compared over a wide depth range. There was no elevation of LDH, or increase in anaerobic poise, in response to the hypoxia of the OMZ. Rather, all 3 enzyme activities were highest at 600 m and generally declined with increasing depth. Contrary to the existing paradigm, S. alascanus and S. altivelis were not found to be shallow- and deep-living congeners. Rather, S. altivelis is a permanent resident of deep water, while S. alascanus settles in shallow water then migrates to deep water with the onset of sexual maturity. When living in deep water, the supposed shallow water species, S. alascanus: maintains higher activities of all enzymes and grows an order of magnitude larger (>5000 vs <500 g). In deep-water slope habitats expected patterns of allometric scaling of white muscle enzyme activities appear to be altered by the limitations of food and oxygen availability, a pattern previously observed in flatfishes. RP Vetter, RD (reprint author), NATL OCEAN & ATMOSPHER ADM, SW FISHERIES SCI CTR, LA JOLLA, CA 92038 USA. NR 36 TC 41 Z9 41 U1 2 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 155 BP 173 EP 188 DI 10.3354/meps155173 PG 16 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XY395 UT WOS:A1997XY39500015 ER PT J AU Lindquist, N Bolser, R Laing, K AF Lindquist, N Bolser, R Laing, K TI Timing of larval release by two Caribbean demosponges SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE sponges; larvae; timing of larval release; larval dispersal; larval palatability ID GREAT-BARRIER-REEF; ASCIDIAN ECTEINASCIDIA-TURBINATA; MARINE INVERTEBRATE LARVAE; CHEMICAL DEFENSE; SPONGE; SETTLEMENT; BEHAVIOR; RECRUITMENT; DISPERSAL; PORIFERA AB The timing of larval release has important implications for a larva's potential vulnerability to predators and environmental stresses. For larvae with planktonic periods of only minutes to hours, timing of larval release also determines the light levels that larvae experience, which can strongly influence their settlement behavior. We placed larval traps over colonies of 2 common Caribbean sponges and found that both species released larvae during daylight hours. Niphates digitalis generally releases its larvae between 07:00 and 11:00 h, while Callyspongia vaginalis releases its larvae later in the day. Of 17 captured N. digitalis larvae released 0.5 to 1 m above the substrate, 13 remained near the bottom, and 8 of these 13 contacted the substrate within 10 min. For short-lived larvae, daytime release and their photonegative behavior at settlement should drive them to settle in shaded microhabitats that protect juveniles from predators and solar UV radiation. Larvae of N. digitalis and C. vaginalis are distasteful to potential predators; thus they can remain near the bottom with fishes and yet not be consumed. These data support a general co-occurrence of daytime spawning of conspicuous, short-lived larvae and larval distastefulness that previously had been noted only for tropical ascidians. C1 UNIV N CAROLINA, NOAA, NATL UNDERSEA RES CTR, WILMINGTON, NC 28403 USA. RP Lindquist, N (reprint author), UNIV N CAROLINA, INST MARINE SCI, 3431 ARENDELL ST, MOREHEAD CITY, NC 28557 USA. NR 33 TC 26 Z9 28 U1 1 U2 6 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 155 BP 309 EP 313 DI 10.3354/meps155309 PG 5 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XY395 UT WOS:A1997XY39500025 ER PT J AU Ryer, CH Olla, BL AF Ryer, CH Olla, BL TI Altered search speed and growth: social versus independent foraging in two pelagic juvenile fishes SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE bioenergetics; foraging strategy; growth; milkshake effect; shoaling; swimming speed ID THERAGRA-CHALCOGRAMMA; ANOPLOPOMA-FIMBRIA; WALLEYE POLLOCK; BEHAVIOR; METABOLISM; BIOENERGETICS; SABLEFISH; EVOLUTION; ECOLOGY; PREY AB Prior studies have demonstrated that juvenile walleye pollock Theragra chalcogramma forage socially in schools for spatially and temporally clumped food, but forage more independently for spatially and temporally dispersed food. One advantage of social foraging is that fish in schools may be able to locate more food clumps than fish foraging individually. However, data also indicate that walleye pollock swim faster when foraging socially. We conducted laboratory experiments to evaluate the effect of food distribution upon the energetic foraging costs incurred by juvenile walleye pollock and sablefish Anaplopoma fimbria. We predicted that when given identical rations, fish receiving clumped food would swim faster, expending more energy, and therefore grow more slowly than fish receiving dispersed food. After 2 wk under these 2 foraging regimes, juvenile walleye pollock receiving clumped food swam 50 % faster, but experienced 19 % lower growth, than walleye pollock receiving dispersed food. Sablefish demonstrated only a weak swim speed response, with no difference in growth between food distributions. Our results demonstrate that although social foraging may increase encounter rates with food, in some species there may also be an energetic cost for this behavior, which will have an influence upon energetic efficiency, potentially affecting growth and survival. 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 51 TC 15 Z9 15 U1 2 U2 3 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 153 BP 273 EP 281 DI 10.3354/meps153273 PG 9 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XR974 UT WOS:A1997XR97400025 ER PT J AU Minello, TJ Webb, JW AF Minello, TJ Webb, JW TI Use of natural and created Spartina alterniflora salt marshes by fishery species and other aquatic fauna in Galveston Bay, Texas, USA SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE salt marsh; habitat value; habitat creation; restoration; nekton; fishery species ID FUNDULUS-HETEROCLITUS; PENAEUS-AZTECUS; BROWN SHRIMP; TIDAL MARSH; NEKTON USE; DECAPOD CRUSTACEANS; PALAEMONETES-PUGIO; NATANT MACROFAUNA; ORGANIC-CARBON; SOUTH-CAROLINA AB We compared densities of nekton and infauna among 5 natural and 10 created (3 to 15 yr in age) salt marshes in the Galveston Bay system of Texas to test whether these marshes were functionally equivalent. Decapod crustaceans dominated the nekton on the marsh surface during both the spring and the fall. Densities of daggerblade grass shrimp Palaemonetes pugio, the most abundant decapod, were not significantly different among marshes, but the size of these shrimp in created marshes was significantly smaller than in natural marshes. Densities of the marsh grass shrimp Palaemonetes vulgaris and of 3 commercially-important crustaceans (white shrimp Penaeus setiferus, brown shrimp Penaeus aztecus, and blue crab Callinectes sapidus) were significantly lower in created marshes than in natural marshes. Gulf menhaden Brevoortia patronus were the most abundant fish collected, mainly on nonvegetated bottom adjacent to marsh habitats. Fish densities within vegetation (predominantly gobies and pinfish Lagodon rhomboides) were significantly lower in created marshes than in natural marshes. Natural and created marshes, however, did not differ in species richness of nekton. Sediment macro-organic matter and density and species richness of macroinfauna (mainly polychaete worms) were all significantly lower in created marshes than natural marshes. There was a positive relationship in created marshes between marsh age and sediment macro-organic matter, but marsh age was not related to nekton densities. Natural marshes were similar in having low elevations and flooding durations between 74 and 80% of the year; while created marshes were flooded from 43 to 91% of the time. In contrast to marsh age, tidal flooding was often related to nekton densities in marsh habitats. We conclude that marsh elevation and tidal flooding are key characteristics affecting use by nekton and should be considered in marsh construction projects. C1 TEXAS A&M UNIV, DEPT MARINE BIOL, GALVESTON, TX 77553 USA. RP Minello, TJ (reprint author), NATL MARINE FISHERIES SERV, SE FISHERIES SCI CTR, GALVESTON LAB, 4700 AVE U, GALVESTON, TX 77551 USA. NR 64 TC 97 Z9 99 U1 1 U2 32 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1997 VL 151 IS 1-3 BP 165 EP 179 DI 10.3354/meps151165 PG 15 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XE687 UT WOS:A1997XE68700017 ER PT J AU Perrin, WF AF Perrin, WF TI Development and homologies of head stripes in the delphinoid cetaceans SO MARINE MAMMAL SCIENCE LA English DT Review DE taxonomy; development; color pattern; cetacean; delphinoid; delphinid; monodontid; phocoenid; Stenella; Delphinus ID CEPHALORHYNCHUS-COMMERSONII LACEPEDE; EXTERNAL MORPHOLOGY; PIGMENTATION; DOLPHIN; STENELLA; WHALE; POPULATION; MAMMALIA; ATLANTIC; CANADA AB Ontogeny and variation of head stripes were investigated in Stenella attenuata, S. longirostris, and Delphinus delphis. The eye stripe and the blowhole stripe together comprise the bridle. The Anlage of the bridle is a line extending across the back of the head in small fetuses. As the blowhole moves posteriorly and the rostrum lengthens, an inflection point develops in the line above the eye. This point moves forward, creating a progressively greater triangular area between the incipient eye and blowhole stripes. Well before birth, the inflection point is close to the apex of the melon, and the eye and blowhole stripes are narrow and well defined. This process proceeds to varying degrees in the other delphinoids. For example, in Peponocephala electra and in Cephalorhynchus spp., the inflection point migrates only part of the way to the apex of the melon, and the resulting ''blowhole stripe'' remains a broad caplike feature, resembling the state of development in small fetuses of Stenella and Delphinus. A simple eye spot without a stripe may be primitive, as it occurs in non-delphinoid cetaceans. Presence of the bridle only in the delphinids and phocoenids may unite them in a clade exclusive of the monodontids. RP Perrin, WF (reprint author), SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 196 TC 14 Z9 16 U1 0 U2 3 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1997 VL 13 IS 1 BP 1 EP 43 DI 10.1111/j.1748-7692.1997.tb00610.x PG 43 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA WF733 UT WOS:A1997WF73300001 ER PT J AU Barlow, J Gerrodette, T Silber, G AF Barlow, J Gerrodette, T Silber, G TI First estimates of vaquita abundance SO MARINE MAMMAL SCIENCE LA English DT Article DE vaquita; Gulf of California harbor porpoise; Phocoena sinus; abundance; population; line-transect survey; trends; endangered species; Mexico ID HARBOR PORPOISE; PHOCOENA-SINUS; AERIAL SURVEYS; NORTHERN GULF; CALIFORNIA; CONSERVATION; WASHINGTON; OREGON AB The abundance of the only population of vaquitas, Gulf of California harbor porpoise (Phocoena sinus), is estimated from four surveys conducted in Mexico between 1986 and 1993, using a variety of methods. A line-transect approach was applied, using some parameters estimated from a related species, the harbor porpoise (Phocoena phocoena). Vaquita abundance is estimated as 503 (CV = 0.63) from 1986-1988 boat surveys, 885 (CV = 0.50) from 1988-1989 aerial surveys, 572 (CV = 1.43) from a 1991 aerial survey, and 224 (CV = 0.39) from a 1993 ship survey. A weighted log-linear regression indicates a rate of population change (decline) of - 17.7% per year (95% CI = -43.2% to +19.3%) between 1986 and 1993. All of these estimates of vaquita abundance indicate that the species is at a critically low level. C1 MARINE MAMMAL COMMISS,WASHINGTON,DC 20009. RP Barlow, J (reprint author), SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 32 TC 26 Z9 26 U1 5 U2 14 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1997 VL 13 IS 1 BP 44 EP 58 DI 10.1111/j.1748-7692.1997.tb00611.x PG 15 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA WF733 UT WOS:A1997WF73300002 ER PT J AU Hobson, KA Sease, JL Merrick, RL Piatt, JF AF Hobson, KA Sease, JL Merrick, RL Piatt, JF TI Investigating trophic relationships of pinnipeds in Alaska and Washington using stable isotope ratios of nitrogen and carbon SO MARINE MAMMAL SCIENCE LA English DT Article DE northern fur seal; Steller sea lion; harbor seal; Callorhinus ursinus; Eumetopias jubatus; Phoca vitulina; stable-isotope analysis; carbon-13; nitrogen-15 ID NORTHERN FUR SEALS; EASTERN BERING SEA; CALLORHINUS-URSINUS; THERAGRA-CHALCOGRAMMA; WALLEYE POLLOCK; FEEDING-HABITS; PHOCA-VITULINA; HARBOR SEALS; DIET; FOOD AB We measured stable-nitrogen (delta(15)N) and stable-carbon (delta(13)C) isotope ratios in muscle and hair from 7 northern fur seals (Callorhinus ursinus) from the Pribilof Islands, Alaska, and 27 Steller sea lions (Eumetopias jubatus), and 14 harbor seals (Phoca vitulina) from the Gulf of Alaska and coast of Washington Scare, in order to contrast dietary information derived from isotopic vs. available conventional dietary studies. Stable-nitrogen-isotope analysis of muscle revealed that harbor seals were enriched over sea lions (mean delta(15)N = 18.6 parts per thousand vs. 17.5 parts per thousand) which were in Nn enriched over northern fur seals (mean delta(15)N = 16.6 parts per thousand. Trophic segregation among these species likely results primarily from differential reliance on herring (Clupea harengus), Atka mackerel (Pleurogrdmmus monopterygius), and large us. small walleye pollock (Theregra chalcogramma). According to their delta(15)N values, adult male Steller sea lions showed a higher trophic position than adult females (mean delta(15)N: 18.0 parts per thousand vs. 17.2 parts per thousand) whereas adult female northern fur seals were trophically higher than juvenile male fur seals (mean delta(15)N: 16.5 parts per thousand vs. 15.0 parts per thousand). Each of these observed differences likely resulted from differential reliance on squid or differences in the size range of pollock consumed. Three northern fur seal pups showed higher delta(15)N enrichment over adults (mean 17.7 parts per thousand vs. 15.8 parts per thousand) due to their reliance on their mother's milk. Stable-carbon isotope measurements of hair revealed a dine toward more negative values with latitude. Segregation in hair delta(13)C between Steller sea lions and harbor seals off the coast of Washington (mean delta(13)C: -13.6 parts per thousand vs. -15.0 parts per thousand) reflected the greater association of harbor seals with freshwater input from the Columbia River. Our study demonstrates the utility of the stable isotope approach to augment conventional dietary analyses of pinnipeds and other marine mammals. C1 NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. NATL BIOL SERV,ANCHORAGE,AK 99503. RP Hobson, KA (reprint author), PRAIRIE & NO WILDLIFE RES CTR,115 PERIMETER RD,SASKATOON,SK S7N 0X4,CANADA. NR 70 TC 152 Z9 154 U1 5 U2 38 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1997 VL 13 IS 1 BP 114 EP 132 DI 10.1111/j.1748-7692.1997.tb00615.x PG 19 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA WF733 UT WOS:A1997WF73300006 ER PT J AU OSullivan, S Mullin, KD AF OSullivan, S Mullin, KD TI Killer whales (Orcinus orca) in the northern Gulf of Mexico SO MARINE MAMMAL SCIENCE LA English DT Article C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,PASCAGOULA,MS 39568. NR 29 TC 5 Z9 8 U1 0 U2 3 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1997 VL 13 IS 1 BP 141 EP 147 DI 10.1111/j.1748-7692.1997.tb00618.x PG 7 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA WF733 UT WOS:A1997WF73300009 ER PT J AU Gentry, RL Casanas, VR AF Gentry, RL Casanas, VR TI A new method for immobilizing otariid neonates SO MARINE MAMMAL SCIENCE LA English DT Article C1 SCRIPPS INST OCEANOG,CTR MARINE BIOTECHNOL & BIOMED,LA JOLLA,CA 92093. RP Gentry, RL (reprint author), NOAA,NATL MARINE MAMMAL LAB,NMFS,7600 SAND POINT WAY NE C15700,SEATTLE,WA 98115, USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1997 VL 13 IS 1 BP 155 EP 157 DI 10.1111/j.1748-7692.1997.tb00621.x PG 3 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA WF733 UT WOS:A1997WF73300012 ER PT J AU Herrick, SF Rader, B Squires, D AF Herrick, SF Rader, B Squires, D TI Access fees and economic benefits in the Western Pacific United States purse seine tuna fishery SO MARINE POLICY LA English DT Article DE access fees; short-run profits; western Pacific tuna ID MODELS AB Ideally, fees paid by distant water fishing nations for access to tuna resources in exclusive economic zones would approximate the net economic value of the tuna harvested, while leaving fishing operations profitable, This paper develops a linear programming approach to assess short-run profitability, optimum access fees and net economic benefits for US tropical tuna purse seiners operating under the South Pacific Tuna Treaty, Results suggest that there is potential for sizable short-run profits and net economic benefits after payment of an access fee equal to the imputed marginal value of the tuna harvested. Published by Elsevier Science Ltd. RP Herrick, SF (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 32 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0308-597X J9 MAR POLICY JI Mar. Pol. PD JAN PY 1997 VL 21 IS 1 BP 83 EP 96 DI 10.1016/S0308-597X(96)00048-6 PG 14 WC Environmental Studies; International Relations SC Environmental Sciences & Ecology; International Relations GA WE730 UT WOS:A1997WE73000007 ER PT J AU Siewert, TA AF Siewert, TA TI The International Institute of Welding: Report on 1996 actions SO MATERIALS EVALUATION LA English DT Article RP Siewert, TA (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD JAN PY 1997 VL 55 IS 1 BP 50 EP & PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA WC142 UT WOS:A1997WC14200006 ER PT S AU Dimeo, F Semancik, S Cavicchi, RE Suehle, JS Tea, NH Vaudin, MD Kelliher, JT AF Dimeo, F Semancik, S Cavicchi, RE Suehle, JS Tea, NH Vaudin, MD Kelliher, JT BE Reed, ML Elwenspoek, M Johansson, S Obermeier, E Fujita, H Uenishi, Y TI Silicon microhotplate arrays as a platform for efficient gas sensing thin film research SO MATERIALS FOR MECHANICAL AND OPTICAL MICROSYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium I - Materials in Microsystems, at the 1996 MRS Fall Meeting CY DEC 04-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Applications for quantitative detection of gas concentrations exist in areas as diverse as manufacturing processing, environmental monitoring, and medical diagnostics, and require devices that are fast, robust, reliable, and low cost. Integrated arrays of thin film gas sensors are being developed to satisfy these demands, but many questions remain with respect to the choice and fabrication methods of the optimal active layers. We have employed silicon micromachining techniques to fabricate arrays of microhotplate structures that serve not only as the sensor device, but also as a multifaceted platform to investigate novel thin film processing, new active materials combinations, and in situ as well as post-deposition characterization techniques. Metal Organic Chemical Vapor Deposition (MOCVD) has been used to fabricate varied forms of SnO2 and Pt thin alms on silicon microhotplate array elements. The arrays consist of micromachined, suspended silicon resistive heaters with extremely fast thermal rise times, similar to 3 ms. The thermally selective nature of the MOCVD process limits deposition to selected elements. Array elements also have surface electrical contacts that permit the measurement of the resistance of the thin films both during deposition, as well as when used in the gas sensing mode. Microhotplate based studies of how processing affects properties relevant to gas sensing, e.g. morphology, grain size, oxygen stoichiometry, will be discussed. RP Dimeo, F (reprint author), NIST,PROC MEASUREMENTS DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-348-7 J9 MATER RES SOC SYMP P PY 1997 VL 444 BP 203 EP 208 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied SC Engineering; Materials Science; Physics GA BH52A UT WOS:A1997BH52A00028 ER PT S AU Klein, S Hauptmann, A Vandiver, PB AF Klein, S Hauptmann, A Vandiver, PB BE Vandiver, PB Druzik, JR Merkel, JF Stewart, J TI Refractory ceramics from an Iron Age bronze melting worksbop at Khirbet edh-Dharih, Jordan SO MATERIALS ISSUES IN ART AND ARCHAEOLOGY V SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Issues in Art and Archaeology V CY DEC 03-05, 1996 CL BOSTON, MA SP Mat Res Soc AB An excavation at Khirbet edh-Dharih implemented by the Institut Francais D'Archaeologie du Proche-Orient brought forth a few archaeometallurgical remains such as lumps of bronze, slags, and refractory ceramic fragments. Khirbet edh-Dharih is located in Jordan, near the Feinan area at Wadi Arabah. The Feinan area is well known as a major supplier of copper in the Near Eases history from the Chalcolithic to the Roman period. The remains from Khirbet edh-Dharih were dated from the Iron Age II, and they are pointing to a workshop for further treatment of copper from Feinan. Khirbet edh-Dharih is the first bronze melting site excavated in the Feinan copper district. RP Klein, S (reprint author), NATL INST STAND & TECHNOL,DIV MET,MAILSTOP 223-B164,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-366-5 J9 MATER RES SOC SYMP P PY 1997 VL 462 BP 135 EP 142 PG 8 WC Archaeology; Art; Materials Science, Multidisciplinary SC Archaeology; Art; Materials Science GA BJ83R UT WOS:A1997BJ83R00014 ER PT B AU White, G Breiner, D Jiang, Q AF White, G Breiner, D Jiang, Q BE Varadan, VV Chandra, J TI Damage generated in cyclically loaded PZT SO MATHEMATICS AND CONTROL IN SMART STRUCTURES - SMART STRUCTURES AND MATERIALS 1997 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mathematics and Control in Smart Structures - Smart Structures and Materials 1997 CY MAR 03-06, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, USAF Wright Lab, Def Adv Res Projects Agcy, Amer Inst Chem Engineers, Amer Phys Soc, Div Mat Phys, Ceram Soc Japan, USA Res Lab, Intelligent Mat Forum, Japan DE PZT; cyclic; stress; temperature; time dependence AB A soft PZT was subjected to cyclic loading at its resonance frequency. Both the piezoelectric coefficient, d(31), and the transverse coupling coefficient, k(31), decreased in a manner consistent with 90 degrees and 180 degrees domain reorientation, with the greatest decrease coinciding with the largest stress and temperature. In contrast, for high loads and temperatures, the elastic compliance, s(11)(E), and the dielectric constant, K-33, decreased in a manner consistent with increased, rather than decreased, alignment of the c-axes. RP White, G (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 0 TC 3 Z9 3 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2452-8 J9 P SOC PHOTO-OPT INS PY 1997 VL 3039 BP 136 EP 143 DI 10.1117/12.276532 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Multidisciplinary; Mathematics, Applied; Optics SC Engineering; Materials Science; Mathematics; Optics GA BJ12X UT WOS:A1997BJ12X00012 ER PT J AU Mesinger, F AF Mesinger, F TI Dynamics of limited-area models: Formulation and numerical methods SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Limited-Area and Variable Resolution Models CY OCT, 1995 CL BEIJING, PEOPLES R CHINA SP China Meteorol Adm, World Meteorol Org ID DEFINITE ADVECTION SCHEME; THERMAL COMPRESSION WAVES; FLUX-CORRECTED TRANSPORT; UPPER BOUNDARY-CONDITION; MESOSCALE-MODEL; HYDROSTATIC EQUATIONS; WEATHER PREDICTION; DIFFERENCE SCHEME; STAGGERED GRIDS; TOTAL-ENERGY AB Following a few historical remarks, approximations used in formulating the ''dynamics'' of limited-area and variable resolution atmospheric forecasting models are reviewed. Particular attention is given to current efforts to relax or remove the hydrostatic approximation. Turning to numerical methods used in discretizing the equations, an attempt is made to record recent work and to clarify the motivation for the various approaches being followed by different modeling centers. Topics commented upon include: semi-Lagrangian methods, numerical formulation of nonhydrostatic models, resolution, the eta (step-mountain) vs sigma or isentropic/sigma vertical coordinate, choice of the vertical grid, numerics of the propagation of gravity waves, and the box-average vs point-sample treatment of predicted variables. It is finally pointed out that the extraordinary diversity of roads being taken shows that a lot remains to be discovered as to what possible rewards may be found in exploring one or the other of the principles underlying the methods being developed. C1 US NATL CTR ENVIRONM PREDICT, UCAR VISITOR RES PROGRAM, CAMP SPRINGS, MD USA. NR 90 TC 16 Z9 16 U1 0 U2 0 PU SPRINGER WIEN PI WIEN PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA SN 0177-7971 EI 1436-5065 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 1997 VL 63 IS 1-2 BP 3 EP 14 DI 10.1007/BF01025360 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XJ470 UT WOS:A1997XJ47000002 ER PT J AU Purser, RJ Rancic, M AF Purser, RJ Rancic, M TI Conformal octagon: An attractive framework for global models offering quasi-uniform regional enhancement of resolution SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID SHALLOW-WATER EQUATIONS; VARIABLE-RESOLUTION AB With the increasingly widespread adoption of massively parallel processing (MPP) computers for applications in computational fluid dynamics it becomes appropriate to reconsider the geometrical configuration of the computational grid that best suits the problem. In the case of global numerical weather prediction we have recently advocated a conformal spherical-cubic geometry. Among its merits, this grid lends itself naturally to simple domain-decomposition and obviates the need for polar filtering. Here we extend the same principles, but with an emphasis on the problem of regional forecasting. In this case we observe that it is possible to cover the global domain with a conformal grid geometry based on the mapping to the sphere of a back-to-back pair of octagonal regions. In the most symmetrical case, each octagon maps to a hemisphere. By compounding this mapping with a nonhomogeneous conformal mapping of the sphere to itself, one can also arrange to have quasi-uniform enhanced resolution of the resulting grid inside any chosen circle on the sphere, at the expense of relatively coarse resolution degrading gradually with distance outside the circle of interest. With appropriate grid dimensions, the new 'conformal octagon' decomposes naturally into several identical square subdomains for efficient distribution over the nodes of an MPP computer. C1 GEN SCI CORP, LAUREL, MD USA. RP Purser, RJ (reprint author), NATL CTR ENVIRONM PREDICT, UCAR VISITING SCI PROGRAM, W-NP2 ROOM 207, WASHINGTON, DC 20233 USA. NR 26 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER WIEN PI WIEN PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA SN 0177-7971 EI 1436-5065 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 1997 VL 62 IS 1-2 BP 33 EP 48 DI 10.1007/BF01037478 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WR483 UT WOS:A1997WR48300004 ER PT J AU Beck, CM AF Beck, CM TI Toward a revival of classical analysis SO METROLOGIA LA English DT Article AB Among the analytical methods used to determine chemical composition, there are two special methods based on reaction chemistry. These are gravimetry and titrimetry, and taken together they are called classical analysis. They are special because they lead directly to independent values of chemical quantities expressed in SI units. Gravimetry and titrimetry can be performed in such a way that their operation is completely understood, and all significant sources of error in the measurement process can be evaluated and expressed in SI units together with a complete uncertainty budget. Such chemical measurements are metrologically valid and stand alone. They have no need to be compared with a reference material of the quantity being measured and therefore are called definitive or primary methods. In this paper the basic equations and terms of gravimetry and titrimetry are discussed, together with detailed examples of each. This is followed by a discussion of the errors associated with gravimetry and titrimetry, and instrumental techniques that can be used for evaluating these errors. There is also a discussion of the uncertainties associated with both systematic and random errors in gravimetry and titrimetry. The paper is underpinned by historical sketches of several important issues and scientists connected with the development of classical analysis. A case is made for a revival of the use of classical analysis in chemical metrology, together with some suggestions as to how such a revival might be implemented. RP Beck, CM (reprint author), NIST,STANDARD REFERENCE MAT PROGRAM,GAITHERSBURG,MD 20899, USA. NR 34 TC 8 Z9 8 U1 0 U2 3 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 1 BP 19 EP 30 DI 10.1088/0026-1394/34/1/4 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WL403 UT WOS:A1997WL40300004 ER PT J AU Watters, RL Eberhardt, KR Beary, ES Fassett, JD AF Watters, RL Eberhardt, KR Beary, ES Fassett, JD TI Protocol for isotope dilution using inductively coupled plasma-mass spectrometry (ICP-MS) for the determination of inorganic elements SO METROLOGIA LA English DT Article AB The Comite Consultatif pour la Quantite de Matiere (CCQM) endeavours to identify and carry out key activities with the objective of facilitating world-wide comparability and traceability of chemical measurements. Towards this goal, the CCQM has identified comparisons to be carried out using candidate primary methods of chemical analysis. One such method is isotope dilution mass spectrometry. In the first comparison carried out by the CCQM (Study I), the concentrations of various inorganic elements were determined in water solutions using IDMS. The results did not meet the target level of 1% maximum relative deviation from the reference values of the unknowns. It was concluded that more guidance was necessary on the execution of the IDMS method and that a detailed protocol should be developed. Participants would use inductively coupled plasma (ICP) as the ionization source. Here we present the protocol developed for use by CCQM participants in the next comparison (Study III) on the determination of the concentration of lead in water using the IDMS method with an inductively coupled plasma-mass spectrometer. RP Watters, RL (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 2 TC 69 Z9 70 U1 0 U2 7 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 1 BP 87 EP 96 DI 10.1088/0026-1394/34/1/13 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WL403 UT WOS:A1997WL40300013 ER PT J AU Leitner, A Witzani, J Boutillon, M AllisyRoberts, P Delaunay, F Leroy, E Lamperti, P Strachotinsky, C Csete, I AF Leitner, A Witzani, J Boutillon, M AllisyRoberts, P Delaunay, F Leroy, E Lamperti, P Strachotinsky, C Csete, I TI International comparisons of air kerma standards in Cs-137 gamma radiation SO METROLOGIA LA English DT Article ID ION CHAMBERS; ATTENUATION AB Comparisons of the air kerma standards of six national laboratories, carried out in Cs-137 gamma radiation, show an overall agreement of 0,8 % between the standards. This result is not quite as good as that of comparisons in Co-60 gamma radiation, mainly because the evaluation of the ionization-chamber wall correction is less accurate for Cs-137 radiation. However, this agreement is acceptable for radio-protection applications. C1 BUR INT POIDS & MESURES,SEVRES,FRANCE. BNM,LAB PRIMAIRE RAYONNEMENTS IONISANTS,GIF SUR YVETTE,FRANCE. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. OSTERREICH FORSCHUNGSZENT SEIBERSDORF GMBH,VIENNA,AUSTRIA. ORSZAGOS MERESUGYI HIVATAL,BUDAPEST,HUNGARY. RP Leitner, A (reprint author), BUNDESAMT EICH & VERMESSUNGSWESEN,VIENNA,AUSTRIA. RI DELAUNAY, Frank/D-8766-2011 OI DELAUNAY, Frank/0000-0002-5443-4459 NR 18 TC 3 Z9 3 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 2 BP 169 EP 175 DI 10.1088/0026-1394/34/2/8 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XD687 UT WOS:A1997XD68700008 ER PT J AU Robertson, AR Heydemann, PLM Castelazo, IA AF Robertson, AR Heydemann, PLM Castelazo, IA TI North American Metrology Cooperation (NORAMET) SO METROLOGIA LA English DT Article AB NORAMET is a regional cooperation in metrology, involving the national measurement laboratories of Canada, Mexico and the United States of America. Most of its current activities are focused on establishing and documenting the degree of equivalence of the calibration services offered by members. This will be done by comparisons of key standards and techniques and by exchanges of visits to establish mutual confidence, The purpose is to facilitate international trade by providing assurance that each country's measurement system is traceable to the SI units with stated uncertainties. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. CTR NACL METROL,CTR QUERETARO 76000,QUERETARO,MEXICO. RP Robertson, AR (reprint author), NATL RES COUNCIL CANADA,OTTAWA,ON K1A 0R6,CANADA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 2 BP 195 EP 196 DI 10.1088/0026-1394/34/2/12 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XD687 UT WOS:A1997XD68700012 ER PT J AU Furukawa, GT Mangum, BW Strouse, GF AF Furukawa, GT Mangum, BW Strouse, GF TI Effects of different methods of preparation of ice mantles of triple point of water cells on the temporal behaviour of the triple-point temperatures SO METROLOGIA LA English DT Article AB We report results of an investigation of the temporal variation of the temperature of triple point of water (TPW) cells, in which the ice mantles were prepared by four different techniques using: (i) solid CO2, (ii) an immersion cooler, (iii) liquid-nitrogen-cooled rods, and (iv) liquid nitrogen (LN), first passing cold nitrogen vapours and then LN directly into the wells of the cells. The temperature of the TPW cell water was either approximately 274 K or 295 K when the freezing of the ice mantle was started. No visible cracks formed during the preparation of any of the mantles using the crushed solid-CO2 or the immersion-cooler method, but all of the ice mantles cracked when prepared using the LN-cooled-rod and LN techniques. The cracked mantles, however, soon healed. Initially, the temperatures of the mantles prepared by the four methods varied, but after about three or four days they agreed to within 0,1 mK; after one week they agreed to within 0,03 mK, except for mantles prepared by the LN technique, for which nine days were once required for one of the mantles; after eleven days, the results were practically the same. It appears that the temperature variations observed during the first few days following the preparation of mantles could be caused by a combination of (i) temperature decrease due to introduction of strains in the ice and to formation of fine ice crystals during the preparation of the mantle and (ii) temperature increase due to the relief of strains and the gradual conversion of fine ice crystals to larger ice crystals. Mantles that underwent severe cracking thereby released most of the energy associated with the large strains introduced during preparation of the mantle. RP Furukawa, GT (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 12 TC 15 Z9 16 U1 0 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 3 BP 215 EP 233 DI 10.1088/0026-1394/34/3/3 PG 19 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XY384 UT WOS:A1997XY38400003 ER PT J AU Song, JF Low, S Pitchure, D Germak, A DeSogus, S Polzin, T Yang, HQ Ishida, H Barbato, G AF Song, JF Low, S Pitchure, D Germak, A DeSogus, S Polzin, T Yang, HQ Ishida, H Barbato, G TI Establishing a world-wide unified Rockwell hardness scale with metrological traceability SO METROLOGIA LA English DT Article AB Recently developed microform measurement techniques have reduced the measurement uncertainties in the geometry of Rockwell diamond indenters. It is now possible to establish standard-grade Rockwell diamond indenters characterized by high geometric uniformity, high hardness performance uniformity, interchangeability and reproducibility. By using the standard indenters under different national standard machines and a standardized testing cycle, a world-wide unified Rockwell hardness scale could be established with metrological traceability, stability and reproducibility. Geometric measurements and hardness tests in five laboratories have shown that tightly controlled indenter geometry can significantly improve the consistency of Rockwell C hardness (HRC) measurements. These results support the feasibility of establishing a world-wide unified HRC scale with an expanded uncertainty of approximately +/- 0,2 HRC and without significant bias with respect to an ideal scale. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ist Metrol G Colonetti, Turin, Italy. Mat Prufungsamt Nordheim Westfalen, NRW, MPA, Dortmund, Germany. Natl Inst Metrol, Beijing, Peoples R China. Natl Res Lab Metrol, Tsukuba, Ibaraki, Japan. Univ Messina, S Agata, Italy. RP Song, JF (reprint author), Natl Inst Stand & Technol, A117 Metrol, Gaithersburg, MD 20899 USA. RI Germak, Alessandro/E-9685-2011; OI Germak, Alessandro/0000-0003-4985-9118; BARBATO, Giulio/0000-0001-8232-0099 NR 33 TC 8 Z9 8 U1 0 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 4 BP 331 EP 342 DI 10.1088/0026-1394/34/4/6 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA YR322 UT WOS:000071483800006 ER PT J AU Mangum, BW Bloembergen, P Chattle, MV Fellmuth, B Marcarino, P Pokhodun, AI AF Mangum, BW Bloembergen, P Chattle, MV Fellmuth, B Marcarino, P Pokhodun, AI CA Working Grp 1 Com Consultatif Thermometrie TI On the international temperature scale of 1990 (ITS-90) Part I: Some definitions SO METROLOGIA LA English DT Article AB In this paper, we specify the purpose of an international temperature scale and present some definitions that are basic to the International Temperature Scale of 1990. These definitions include those for non-uniqueness and for the temperature fixed points underlying the scale. Three types of non-uniqueness are identified. C1 NIST, Gaithersburg, MD 20899 USA. RP Mangum, BW (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 7 TC 21 Z9 21 U1 0 U2 3 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 5 BP 427 EP 429 DI 10.1088/0026-1394/34/5/8 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC646 UT WOS:000072602400008 ER PT J AU Zhang, NF Postek, MT Larrabee, RD AF Zhang, NF Postek, MT Larrabee, RD TI Statistical models for estimating the measurement of pitch in metrology instruments SO METROLOGIA LA English DT Article ID SEM AB The measurement of pitch in metrology instruments is thought to be a benign self-compensating function. In the course of issuing the new scanning electron microscope standard SRM 2090, a new algorithm for the measurement of pitch was developed. This is based on linear regression models. For a pitch measurement, a regression line is traditionally fitted to each edge of the data independently, then the distance between some arbitrary threshold on that line is determined. The new algorithm eliminates the need for a threshold. An evaluation of uncertainty of the measurement process is also described. C1 NIST, Stat Engn Div, Gaithersburg, MD 20899 USA. NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Zhang, NF (reprint author), NIST, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 10 TC 6 Z9 6 U1 0 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 6 BP 467 EP 477 DI 10.1088/0026-1394/34/6/3 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZG743 UT WOS:000073034900003 ER PT J AU Ehrlich, CD Rasberry, SD AF Ehrlich, CD Rasberry, SD TI Metrological timelines in traceability SO METROLOGIA LA English DT Article AB There is a growing requirement for an internationally accepted system of recognition of measurement capabilities and relationships within and among countries, to facilitate seamless global commerce and trade. As a result, metrologists world-wide have recently developed increased interest in the concept and definition of traceability. Classically, traceability provides a way of relating the results of a measurement (or value of a standard) to higher-level standards. Such standards are usually national or international standards, and the comparisons used to provide the traceability must have well-understood uncertainties. An additional complexity arises because all instruments and standards are subject to change, however slight, over time. This paper develops approaches for dealing with the effects of such time-dependent changes as a part of traceability statements. The use of metrological timelines provides a means of effectively visualizing these relationships in a statement of traceability. When the rate of change in the measurement process is sufficiently small, the approach proposed here is less important. However, documented measurement assurance procedures are required at all levels so that appropriate uncertainties may be estimated with confidence. When laboratory or national boundaries are crossed in the traceability process, other factors come into play, and the original concept of traceability can become obscure. It is becoming common to hear the term "equivalence" used to describe these more complex measurement relationships. C1 NIST, Technol Serv, Gaithersburg, MD 20899 USA. RP Ehrlich, CD (reprint author), NIST, Technol Serv, Gaithersburg, MD 20899 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1997 VL 34 IS 6 BP 503 EP 514 DI 10.1088/0026-1394/34/6/6 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZG743 UT WOS:000073034900006 ER PT B AU Postek, MT Vladar, AE Davidson, MP AF Postek, MT Vladar, AE Davidson, MP BE Jones, SK TI Fourier transform feedback tool for scanning electron microscopes used in semiconductor metrology SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE Fourier transform; image analysis; metrology; resolution; performance; scanning electron microscope; sharpness AB The utility of the sharpness concept for use on metrology scanning electron microscopes (SEM) as implemented through the Fourier transform technique has been clearly demonstrated and documented. The original methods for sharpness analysis were labor-intensive and therefore not suited to industrial applications like semicon-ductor integrated circuit production. We have integrated these techniques into an easy to use and stand alone software package called SEM Monitor which makes the analysis easy and moreover can serve as a prototype for integration into a production tool. This paper will present the general philosophy of the system and analytical data taken from both laboratory and production instruments to prove both the relevance of the sharpness concept and the usefulness of this tool for SEM performance monitoring. RP Postek, MT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 68 EP 79 PG 12 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00006 ER PT B AU Silver, RM Potzick, J Scire, F Evans, C McGlauflin, M Kornegay, E Larrabee, R AF Silver, RM Potzick, J Scire, F Evans, C McGlauflin, M Kornegay, E Larrabee, R BE Jones, SK TI A method to characterize overlay tool misalignments and distortions SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH AB A new optical alignment artifact under development fit NIST is described. This artifact, referred to as a stepped microcone, is designed to assist users and manufacturers of overlay metrology tools in the reduction of tool-induced measurement errors. We outline the design criteria and diamond turning lathe techniques used for manufacturing this structure. The alignment methods using this artifact allow the separation of error components associated with the optical system or the mechanical positioning systems as encountered when performing measurements in different focal planes. Although some difficulties have been encountered in the actual diamond turning process, the data presented show some improvements with the more recent prototypes which indicate that this method of fabrication will be useful. Photometer scan data and CCD image acquisition hardware show a significant optical response at the step edges from these structures. Initial analysis of the optical response of these edges shows sensitivity to the material used and the details of the manufacturing processes. RP Silver, RM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 143 EP 155 DI 10.1117/12.275965 PG 13 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00013 ER PT B AU Postek, MT Ho, HJ Weese, HL AF Postek, MT Ho, HJ Weese, HL BE Jones, SK TI Dimensional metrology at the nanometer level: Combined SEM and PPM SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE atomic force microscopy; metrology; proximal probe microscopy; resolution; scanning electron microscope; standards; standard reference materials AB The National Institute of Standards and Technology (NIST) is currently exploring the potentials afforded by the incorporation of a commercial proximal probe microscope (PPM) operating in the scanning tunneling or atomic force mode into a high resolution field emission scanning electron microscope (SEM). This instrument will be used in the development of NIST traceable standards for dimensional metrology at the nanometer level. The combination of the two microscopic techniques provides: high precision probe placement, the capability of measuring and monitoring the probe geometry, monitoring the scanning of the probe across the feature of interest and an ability for comparative microscopy. The integration of the commercial instrument is the first: step in the development of a custom NIST integrated SEM/SxM metrology instrument (with the x variable depending upon the type of probe being used). This paper presents early results regarding the integration of the two instruments and the application of these instruments to the development of SRM 2090 and the SEM sharpness standard. RP Postek, MT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 250 EP 263 PG 14 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00022 ER PT B AU Zhang, NF Postek, MT Larrabee, RD Vladar, AE Keery, WJ Jones, SN AF Zhang, NF Postek, MT Larrabee, RD Vladar, AE Keery, WJ Jones, SN BE Jones, SK TI A statistical measure for the sharpness of the SEM images SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE image analysis; Fourier transform; metrology; kurtosis; scanning electron microscope; sharpness AB Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. Testing and proving that the instrument is performing at a satisfactory level of sharpness is an important aspect of quality control. The application of Fourier analysis techniques to the analysis of SEM images is a useful methodology for sharpness measurement. In this paper, a statistical measure :known as the multivariate kurtosis, is proposed as a useful measure of the sharpness of SEM images. Kurtosis is designed to be a measure of the degree of departure of a probability distribution from the Gaussian distribution. It is a function of both the fourth and the second moments of a probability distribution. For selected SEM images, the two-dimensional spatial Fourier transforms were computed. Then the bivariate kurtosis of this Fourier transform was calculated as though it were a probability distribution, and that kurtosis evaluated as a characterization tool. Kurtosis has the distinct advantage that it is a parametric (i.e., a dimensionless) measure and is sensitive to the presence of the high spatial frequencies necessary for acceptable levels of sharpness. The applications of this method to SEM metrology will be discussed. RP Zhang, NF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 375 EP 387 DI 10.1117/12.275935 PG 13 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00034 ER PT S AU Hsu, SM Zhang, XH AF Hsu, SM Zhang, XH BE Bhushan, B TI Lubrication: Traditional to nano-lubricating films SO MICRO/NANOTRIBOLOGY AND ITS APPLICATIONS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on Micro/Nanotribology and Its Applications CY JUN 16-28, 1996 CL SESIMBRA, PORTUGAL SP NATO Sci & Environm Affairs Div, USN, Off Naval Res, Natl Sci Fdn, US AB Boundary lubricating film properties are crucial to the understanding of current lubrication technology as well as in advancing the frontier of lubrication science. This paper reviews the current understanding of boundary lubricating films and presents some new techniques for the measurement of film properties. As the scale of the technologies decreases, devices such as Micro-Mechanical Devices (MMDs) and magnetic hard disk system require an ever decreasing scale of lubrication technology. Monomolecular films, by necessity, are required to provide friction control, wear protection, and system durability. Therefore, film designs are needed to protect such systems. This paper describes some new measurement techniques as well as the conceptual framework for monomolecular film design. RP Hsu, SM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-132X BN 0-7923-4386-7 J9 NATO ADV SCI I E-APP PY 1997 VL 330 BP 399 EP 414 PG 16 WC Engineering, Multidisciplinary; Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH21W UT WOS:A1997BH21W00032 ER PT J AU Schafft, HA Erhart, DL Gladden, WK AF Schafft, HA Erhart, DL Gladden, WK TI Toward a building-in reliability approach SO MICROELECTRONICS RELIABILITY LA English DT Review ID PARTICULATE CONTAMINATION CONTROL; PLASMAS AB Testing-in reliability, as with post-process and life testing, is shown to be no longer a viable response to the aggressive reliability and market-entry demands facing the semiconductor industry. A building-in reliability approach based on identifying and controlling the causes for reduced reliability is described and compared to the traditional testing-in reliability approach. Specific examples of a building-in reliability approach are given. Published by Elsevier Science Ltd C1 MOTOROLA INC, TEMPE, AZ USA. ADV MICRO DEVICES INC, AUSTIN, TX 78739 USA. RP Schafft, HA (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 34 TC 87 Z9 87 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD JAN PY 1997 VL 37 IS 1 BP 3 EP 18 DI 10.1016/0026-2714(96)00235-1 PG 16 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VU258 UT WOS:A1997VU25800002 ER PT B AU Howard, LP Fu, J AF Howard, LP Fu, J BE Friedrich, CR Umeda, S TI Accurate force measurements for miniature mechanical systems: a review of progress. SO MICROLITHOGRAPHY AND METROLOGY IN MICROMACHINING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Annual SPIE Conference on Microlithography and Metrology in Micromachining CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST DE AFM; force measurement; MEMS; nanonewton AB A survey of nanonewton force calibration techniques suitable for micro-electromechanical systems (MEMS) is presented. The reviewed techniques include: mass-derived force, pendulums, calibrated master springs, resonance and electromagnetic techniques. Considerable background material is provided to support the hypothesis that virtual power methods, such as those employed on the NIST watt balance are applicable to the MEMS farce calibration problem. A review of progress at NIST on two prototype nanowatt balances designed for MEMS calibrations is given. RP Howard, LP (reprint author), NATL INST STAND & TECHNOL,DEPT PRECIS ENGN,BLDG 220,ROOM A117,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2657-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3225 BP 2 EP 11 DI 10.1117/12.284543 PG 2 WC Engineering, Manufacturing; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BJ57N UT WOS:A1997BJ57N00001 ER PT B AU Postek, MT AF Postek, MT BE Friedrich, CR Umeda, S TI The potentials for inspection and metrology of MEMS using a combined scanning electron microscope (SEM) and proximal probe microscope (PPM) SO MICROLITHOGRAPHY AND METROLOGY IN MICROMACHINING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Annual SPIE Conference on Microlithography and Metrology in Micromachining CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST DE atomic force microscope; metrology; proximal probe microscope; resolution; scanning electron microscope; scanning tunneling microscope; standards; standard reference materials AB The potentials afforded by the incorporation of a commercial proximal probe microscope (PPM) into a high resolution field emission scanning electron microscope (SEM) are substantial for MEMS inspection and metrology. An instrument of this type is currently being tested at the National Institute of Standards and Technology. This instrument will be used in the development of NIST traceable standards for dimensional metrology at the nanometer level. The combination of the two microscopic techniques facilitates: high precision probe placement, the capability of measuring and monitoring the probe geometry, monitoring the scanning of the probe across the feature of interest and an ability for comparative microscopy. The integration of the commercial instrument is the first step in the development Elf a custom NIST integrated SEM/SxM metrology instrument (with the a variable depending upon the type of probe being used). This paper presents early results regarding the integration of the two instruments and the application of these instruments to the development of SRM 2090 and the prototype SEM sharpness standard. RP Postek, MT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2657-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3225 BP 92 EP 101 PG 2 WC Engineering, Manufacturing; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BJ57N UT WOS:A1997BJ57N00010 ER PT S AU Deshler, T Liley, JB Bodeker, G Matthews, WA Hoffmann, DJ AF Deshler, T Liley, JB Bodeker, G Matthews, WA Hoffmann, DJ BE Chakrabarty, DK Gupta, SP TI Stratospheric aerosol following Pinatubo, comparison of the north and south mid latitudes using in situ measurements SO MIDDLE ATMOSPHERE: CHANGES AND ELECTRODYNAMICS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C2.1 and C2.3 Symposia of COSPAR Scientific Commission C on Middle Atmosphere - Changes and Electrodynamics, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Sci & Technol Dev Cty, Int Biosci Networks, Comm Space Res, 3rd World Acad Sci ID SIZE DISTRIBUTION; ERUPTION; VOLATILITY; OZONE AB In situ measurements of stratospheric aerosol concentrations have been conducted approximately monthly at Laramie, Wyoming (41 degrees N), and approximately yearly at Lauder, New Zealand (45 degrees S), from shortly after Pinatubo through November 1996. Vertical aerosol profiles showed quite similar characteristics at the two conjugate sites by November 1992. There were differences in the altitude profiles within the first 8 months following the eruption and in the November 1994 and 1995 measurements. Size distributions fitted to the data were used to calculate aerosol surface area concentrations. Distributions of aerosol surface area versus radius at the altitude of the peak in aerosol surface area also showed similar properties at the two sites. The distributions contained two modes, one centered near 0.1 mu m and one near 0.5 mu m. At both sites the median radii in the small and large modes decreased from 0.18 and 0.6 mu m in November 1992 to 0.08 and 0.4 mu m in November 1995 and 1996. In the same time the maximum surface area in these modes decreased by factors of 5 and 10 for the small and large modes. The descent of the altitude of the peak aerosol surface area in the southern hemisphere is similar to the fall speed of a 0.5 mu m particle, 3-4 km yr(-1). The decay of column integrals of aerosol effective radius, surface area, and volume shows very similar patterns at both sites with the exception of the initial 8 months following the eruption and in November 1994 and 1995 when the Lauder column integrals of surface area and volume are a factor of 2 - 3 above the Laramie measurements. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. NIWA Climate Lauder, Omakau, Cent Otago, New Zealand. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Deshler, T (reprint author), Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. RI Bodeker, Greg/A-8870-2008; OI Bodeker, Greg/0000-0003-1094-5852; Liley, Ben/0000-0002-8844-7928 NR 18 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043308-1 J9 ADV SPACE RES PY 1997 VL 20 IS 11 BP 2089 EP 2095 DI 10.1016/S0273-1177(97)00600-5 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK42B UT WOS:000072091100005 ER PT J AU Brault, JW AF Brault, JW TI New developments in FT spectrometer design SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE FT Spectrometer design; fringe subdivision; digital filter; velocity compensation AB Laser fringes have long been used to establish the x-axis in interferometric spectrometry, but solutions for the intensity axis have been far less satisfactory. Now we are seeing the rapid commercial development of low-cost, medium speed sigma-delta analog-to-digital converters, developed for stereo audio applications. A single chip provides two channels of 20-bit precision at 50 kHz, a significant improvement over many current systems of much greater cost and complexity. However, while the laser works in the spatial domain, this converter operates strictly in the time domain; it cannot be triggered. We have developed a bridge between these two domains: the adaptive digital filter (ADF), which not only permits us to use this converter to obtain measurements at arbitrary times, but as a bonus shows us how to move much of the complexity of an interferometric control and data acquisition system from hardware to software. For example, flexible subdivision (to increase the free spectral range) is easily obtained via a simple and efficient algorithm, free of laser ghosts. Compensation for drive velocity variability is also possible, requiring only a modest amount of computer memory. RP Brault, JW (reprint author), UNIV COLORADO,CIRES,NOAA REAL5,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 121 EP 124 PG 4 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400015 ER PT J AU Zhang, ZM Hanssen, LM Hsia, JJ Datla, RU Zhu, CJ Griffiths, PR AF Zhang, ZM Hanssen, LM Hsia, JJ Datla, RU Zhu, CJ Griffiths, PR TI A procedure for testing the radiometric accuracy of fourier-transform infrared spectrometers SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE fourier-transform spectrometer; radiometric accuracy; transmittance ID TRANSMITTANCE MEASUREMENTS; FILTERS AB We present a simple procedure for evaluation of FT-IR radiometric accuracy, which incorporates the use of calibrated standard reference materials. It starts with the standard practice for testing the FT-IR performance recommended by ASTM, as well as using a wavelength/wavenumber standard reference material developed at the National Institute and Standards and Technology. Further steps are proposed to test the noise level, linearity, and radiometric accuracy. A set of neutral-density filters is being developed for testing the radiometric accuracy. The effects of instrumental resolution and apodization function on the radiometric accuracy for absorption band measurements are also addressed. C1 NIST,GAITHERSBURG,MD 20899. UNIV IDAHO,DEPT CHEM,MOSCOW,ID 83844. NR 10 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 315 EP 316 PG 2 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400071 ER PT J AU Zhang, ZM Hanssen, LM AF Zhang, ZM Hanssen, LM TI A computer simulation of the non-linearity effect on FT-IR measurements SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE FT-IR; detector non-linearity; quantitative measurements AB We have developed a computer simulation algorithm for quantitative examination of the errors induced in FT-IR measurements by non-linearity. Using this program, we have investigated the effect of non-linearity on the measurement of transmittance for several types of optical filters and materials, including neutral-density filters, bandpass filters, and samples with absorption bands. C1 NIST,GAITHERSBURG,MD 20899. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 317 EP 319 PG 3 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400072 ER PT J AU Mang, JT Kumar, S Hammouda, B AF Mang, JT Kumar, S Hammouda, B TI Lyotropic liquid crystals under simple couette and oscillatory shear SO MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS LA English DT Article; Proceedings Paper CT 16th International Liquid Crystal Conference CY JUN 24-28, 1996 CL KENT STATE UNIV, KENT, OH SP Kent State Univ, Dept Phys, Kent State Univ, Dept Chem, Kent State Univ, Liquid Crystal Inst, Int Liquid Crystal Soc, Natl Sci Fdn, Sci & Technol Ctr Adv Liquid Crystalline Opt Mat, Samsung Electr Co Ltd, Gordon & Breach Sci Publ, USN, Off Naval Res, Natl Sci Fdn, Cystaloid Electr, Minolta Ltd, Soc Informat Display, Blake Ind, EM Ind Inc, Instec Inc, Linkam Sci Instruments, ROLIC Ltd, Siemens Energy & Automat Inc, Aerosp Display Syst, McNeil Travel HO KENT STATE UNIV ID A PHASE-TRANSITION; LANDAU THEORY; FLOW; NEMATICS AB Small angle neutron scattering (SANS) has been utilized to investigate the flow properties of the discotic micellar isotropic (I), nematic (N) and lamellar (L-alpha) phases in aqueous solutions of cesium perfluoro-octanate. Under simple shear, no preferred orientation was observed in the I phase. The N phase aligned with the nematic director along the shear gradient velocity, providing the first evidence for a positive value of the viscosity parameter, alpha(2). The L-alpha phase oriented with lamellae parallel to the shear plane. A reorientation of the director near the N-L-alpha transition was witnessed upon cooling from the N phase at a constant shear rate and is attributed, primarily to a change in the value of alpha(2) as a result of increasing lamellar correlations in the nematic phase. The application of oscillatory shear induced significant shifts in the phase boundaries, including nematic-like order some 7 K into the quiescent I phase. C1 KENT STATE UNIV,DEPT PHYS,KENT,OH 44242. KENT STATE UNIV,INST LIQUID CRYSTAL,KENT,OH 44242. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Mang, JT (reprint author), LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. NR 21 TC 6 Z9 6 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1058-725X J9 MOL CRYST LIQ CRYS A JI Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A-Mol. Cryst. Liq. Cryst. PY 1997 VL 303 BP 255 EP 266 DI 10.1080/10587259708039432 PG 12 WC Crystallography SC Crystallography GA YE814 UT WOS:A1997YE81400037 ER PT J AU Moorthi, S AF Moorthi, S TI NWP experiments with a gridpoint semi-Lagrangian semi-implicit global model at NCEP SO MONTHLY WEATHER REVIEW LA English DT Article ID SPURIOUS RESONANT RESPONSE; FINITE-DIFFERENCE SCHEME; ATMOSPHERIC MODEL; PRIMITIVE-EQUATIONS; SOIL HYDROLOGY; FORECAST MODEL; SEMIIMPLICIT; PARAMETERIZATION; INTEGRATION; ELIMINATE AB A series of 5-day forecasts for both winter and summer initial conditions have been performed using a fairly high resolution version (0.9375 degrees latitude-longitude grid with 28 vertical levels) of a gridpoint semi-Lagrangian global forecast model with second-order semi-implicit off-centering and a time step of 1800 s. Most of the physics included in the model are taken from the NCEP operational MRF model. The forecasts are valuated by comparing the anomaly correlations computed using the NCEP operational global analyses with those for the operational MRF forecasts. It is found that the skill scores of the semi-Lagrangian model are fairly close to those of the operational MRF model despite the handicap of not having its own analyses forecast cycle. The forecasts are also used to get an estimate of the climate drift of the model. It is found that the drift is similar to bu somewhat larger than that for the NCEP MRF model. In the second part of the paper, a spatially averaged Eulerian treatment of orography is incorporated into the semi-Lagrangian model and its performance is compared against its semi-Lagrangian counterpart. Eight 5-day forecasts are made, four with the eulerian treatment of orography and four with the semi-Lagrangian treatment, for both first-order and second-order off-centering and with time steps of 1800 and 2700 s, respectively. it is found that the spatially averaged Eulerian representation of orography has superior mass conservation but has slightly more noise at upper levels over the Himalayas. It is also found that first-order off-centering with epsilon=0.1 gives as good a forecast as the second-order off-centering. Increasing the time step from 1800 to 2700 s is associated with some damping of the fields. RP Moorthi, S (reprint author), NCEP, EMC, WORLD WEATHER BLDG, ROOM 207, WASHINGTON, DC 20233 USA. NR 43 TC 16 Z9 16 U1 0 U2 0 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 JAN PY 1997 VL 125 IS 1 BP 74 EP 98 DI 10.1175/1520-0493(1997)125<0074:NEWAGS>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WB964 UT WOS:A1997WB96400005 ER PT S AU Kim, S Han, CC AF Kim, S Han, CC BE Briber, RM Han, CC Peiffer, DG TI Modification of interfacial properties of polymer blends with diblock copolymer SO MORPHOLOGICAL CONTROL IN MULTIPHASE POLYMER MIXTURES SE MATERIALS RESEARCH SOCIETY CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Morphological Control in Multiphase Polymer Mixtures CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The effect of diblock copolymer on the phase-separation process of polymer blends has been investigated by using light scattering and optical microscopic observations. To quench the system into the two phase region, a shear-jump technique is employed instead of the conventional temperature-jump technique. The samples studied are blends of low-molecular-weight polystyrene and polybutadiene with and without added styrene-butadiene block copolymer as a compatibilizer. It was observed that the addition of diblock copolymers could accelerate the phase separation kinetics depending on the shear history. As the concentration of diblock copolymer increases, the distribution of domain sizes becomes narrower and the growth rate slows down. The extent of slowing-down depends on the molecular weight and concentration of the copolymer. The time dependence of domain growth is clearly observed with optical microscopy. RP Kim, S (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0886-7860 BN 1-55899-365-7 J9 MAT RES S C PY 1997 VL 461 BP 185 EP 192 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Polymer Science SC Materials Science; Polymer Science GA BJ28F UT WOS:A1997BJ28F00027 ER PT S AU Bauer, BJ Liu, DW AF Bauer, BJ Liu, DW BE Briber, RM Han, CC Peiffer, DG TI Compatibilizers made from copolymers that exhibit strong interactions SO MORPHOLOGICAL CONTROL IN MULTIPHASE POLYMER MIXTURES SE MATERIALS RESEARCH SOCIETY CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Morphological Control in Multiphase Polymer Mixtures CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Random copolymers of poly(methyl methacrylate-d8) (PMMA) and poly(methacrylic acid) (PMAA) were synthesized and blended with polyethylene oxide (PEO), and SANS was used to estimate the strength of interaction between the various polymer pairs. The addition of PMAA greatly reduced the scattering of the blend, giving a large negative Flory-Huggins interaction parameter. Copolymers of the type PMAA-g-PS, PMAA-r-PS, PMMA-g-PS, and PMMA-r-PS (g = graft, r = random) were used as compatibilizers for the melt blending of mixtures containing 80% PS and 20% PEO. Random copolymers containing half PMMA and half PS or half PMAA and half PS were ineffective compatibilizers while graft copolymers of these polymers produced a much finer dispersion of PEO in PS when blended at 190 degrees C. Graft copolymers made with 90% PS were different, however, with PMMA grafts having only a small effect, while PMAA grafts having a large effect. Random and graft copolymers of PS and PMMA were also used to compatibilize blends of PS and PMMA. The results were similar to the same compatibilizers with blends of PS and PEO, with the graft copolymer causing a finer dispersion. RP Bauer, BJ (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0886-7860 BN 1-55899-365-7 J9 MAT RES S C PY 1997 VL 461 BP 229 EP 238 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Polymer Science SC Materials Science; Polymer Science GA BJ28F UT WOS:A1997BJ28F00034 ER PT S AU Liao, K George, ER Reifsnider, KL AF Liao, K George, ER Reifsnider, KL BE Kalluri, S Bonacuse, PJ TI Characterization of ceramic matrix composite tubes under uniaxial/biaxial monotonic and cyclic loading SO MULTIAXIAL FATIGUE AND DEFORMATION TESTING TECHNIQUES SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Multiaxial Fatigue and Deformation Testing Techniques CY MAY 15, 1995 CL DENVER, CO SP Amer Soc Testing & Mat, Comm Fatigue & Fracture DE ceramic matrix composite; tubes; test methods; ply-level elastic properties; tensile strength; torsional strength; tension-tension fatigue; torsion-torsion fatigue; biaxial fatigue; fatigue (materials); fracture (materials); testing; deformation (materials); multiaxial fatigue AB A method for testing ceramic matrix composite (Almax fiber-reinforced alumina matrix) tubes under monotonic and cyclic loads (tensile/compression, torsional, and biaxial) is described. A data interpretation method is developed to determine ply-level elastic properties from elastic response of the tube measured under monotonic loadings. Monotonic tests were carried out at room temperature to determine the tensile and torsional strengths. Fatigue behavior under tension-tension, torsion-torsion, and biaxial cyclic loads was studied. Damage and failure modes of the tubes under these test conditions are described in detail. RP Liao, K (reprint author), NIST,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 0 TC 2 Z9 2 U1 1 U2 8 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 SN 1071-5827 BN 0-8031-2045-1 J9 AM SOC TEST MATER PY 1997 VL 1280 BP 224 EP 240 DI 10.1520/STP16220S PG 17 WC Mechanics; Materials Science, Characterization & Testing SC Mechanics; Materials Science GA BH07U UT WOS:A1997BH07U00011 ER PT S AU Turner, S Bonevich, JE Maslar, JE Aquino, MI Zachariah, MR AF Turner, S Bonevich, JE Maslar, JE Aquino, MI Zachariah, MR BE Komarneni, S Parker, JC Wollenberger, HJ TI Transmission electron microscopy and electron holography of nanophase TiO2 generated in a flame burner system SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Nanophase TiO2(n-TiO2) particles were generated in a name burner system under three experimental conditions. Selected individual nanoparticles were identified and characterized using selected area electron diffraction, bright-field and, in some cases, dark-field imaging to determine morphology and microstructural features. Previously unknown TiO2 particles with unusual central features were identified as rutile. Electron holography was used to characterize the central features which were found to be consistent with voids. More extensive characterization of individual particles may lead to improved understanding of n-TiO2 nucleation and growth. RP Turner, S (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 93 EP 98 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00014 ER PT J AU Munitz, A Livne, Z Rawers, JC Fields, RJ AF Munitz, A Livne, Z Rawers, JC Fields, RJ TI Cold compaction of nanograin iron alloys SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB A new cold consolidation technique is presented that can produce high density high hardness compacts from ball-milled powders. Ball-milling produces extremely hard, micrometer size particles, made up of nanometer size grains, that resist most methods of cold consolidation. Cold compaction of bcc-Fe and fcc-Fe alloys was accomplished statically and dynamically by cold isostatic pressure, CIP, and cold dynamic compaction, CDC, respectively. Characterization of the resulting compacts and microstructure included optical and scanning electron microscopy, microhardness measurements, and density measurements. The powders were initially either compacted using 0.35 GPa CIP or compacted in a die up to 2.5 GPa. The CIPed compacts of ball-milled powders had a low density of approximately 60%, low hardness, 100 H-v, and no microstructural sign of interparticle bonding. Increasing the compaction pressure to 2.5 GPa increased the density to about 72%, but did not improve bonding. CIPed powder compacts were placed on the anvil of a drop weight impact tester and subjected to drop weight impact-CDC. The resulting compacts had densities approaching 95% of the theoretical values. In some cases the hardness of ball-milled powder compacts exceeded 1400 H-v, and the microstructure showed that intimate particle contact was achieved. There was also evidence of a significant transient temperature rise during dynamic compaction. (C) 1997 Acta Metallurgica Inc. C1 NUCL RES CTR NEGEV,IL-84190 BEER SHEVA,ISRAEL. US BUR MINES,ALBANY,OR 97321. RP Munitz, A (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 4 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 89 EP 92 DI 10.1016/S0965-9773(97)00025-1 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900014 ER PT J AU Newbury, DE AF Newbury, DE TI Characterization of nanoparticles by microbeam analysis and microscopy SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID OPTICAL MICROSCOPY AB The analysis of selected, individual nanoscale particles represents the limit of performance for the most advanced microanalytical techniques. ion beam methods are inadequate for objects with dimensions below 100 nm because of limitations on the number of atoms that can be ionized and collected By using near-field optical techniques, photon beam methods are just beginning to gain the spatial resolution necessary to penetrate the 100 nm barrier. Electron beam techniques such as low voltage (< 5 kV) scanning electron microscopy and high voltage (greater than or equal to 100 kV) analytical electron microscopy are highly effective in the sub-100 nm size regime. Electron-excited X-ray spectrometry can provide accurate elemental analysis in both energy regimes. At high energy, electron energy loss spectrometry (EELS) can also be utilized, augmenting elemental analysis with molecular (compound) information. Analytical masses as small as 1 zg can be characterized with EELS. (C) 1997 Acta Metallurgica Inc. RP Newbury, DE (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 251 EP 260 DI 10.1016/S0965-9773(97)00065-2 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900054 ER PT J AU Chopra, HD Hockey, BJ Swartzendruber, LJ Hua, SZ Chen, PJ Raj, K Lashmore, DS Wuttig, M Egelhoff, WF AF Chopra, HD Hockey, BJ Swartzendruber, LJ Hua, SZ Chen, PJ Raj, K Lashmore, DS Wuttig, M Egelhoff, WF TI Giant magnetoresistance in symmetric spin-valves: Nanostructure and domain dynamics SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID MAGNETIC SUPERLATTICES; MULTILAYERS; EXCHANGE AB High resolution transmission electron microscopy (HRTEM) was used to investigate the nanostructure of symmetric spin-valves (SSV) of the type NiO/Co/Cu/Co/Cu/Co/NiO. The Co/Cu layers grow coherently over each other within columnar grains, the topography of the columns being conformal with that of the underlying NiO layer. Clear evidence is presented which shows that the middle Co layer switches between antiferromagnetic (AF) double left right arrow ferromagnetic (F) aligned states by domain wall nucleation and growth; the Co layers, magnetically pinned by NiO, undergo reversal at high fields (48 mT), but no accompanying wall motion was observed. The wall nucleation of the middle Co layer is explained in terms of the presence of local AF-coupled regions arising from fluctuations in Cu layer thickness. (C) 1997 Acta Metallurgica Inc. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. MAT INNOVAT INC,W LEBANON,NH 03784. FERROFLUIDES CORP,NASHUA,NH 03061. RP Chopra, HD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 451 EP 454 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900087 ER PT J AU Yamamoto, TA Shull, RD Hahn, HW AF Yamamoto, TA Shull, RD Hahn, HW TI Magnetization of iron-oxide/silver nanocomposite by inert gas condensation SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB Magnetization behavior of silver and iron-oxide nanocomposites was studied at low temperatures down to 10K. These composites were superparamagnetic at temperatures higher than 145K. Hysteresis loops at 10K measured in field cooled samples showed an asymmetry and a significant shift toward negative field direction whilst loops of zero-field cooled samples did not It was found that heat treatment in 10% O-2/helium increased the shift whilst that in helium gas decreased it. The unidirectional anisotropy occurring in the composites is discussed. (C) 1997 Acta Metallurgica Inc. C1 NATL INST STAND & TECHNOL,MAGNET MAT GRP,GAITHERSBURG,MD 20899. TH DARMSTADT,D-64295 DARMSTADT,GERMANY. RP Yamamoto, TA (reprint author), UNIV OSAKA PREFECTURE,ADV SCI & TECHNOL RES INST,SAKAI,OSAKA 593,JAPAN. RI Hahn, Horst/G-9018-2011; Shull, Robert/F-5971-2013; OI Hahn, Horst/0000-0001-9901-3861; Yamamoto, Takao/0000-0001-8620-6349 NR 7 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 539 EP 542 DI 10.1016/S0965-9773(97)00119-0 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900108 ER PT J AU Josell, D Cezairliyan, A vanHeerden, D Murray, BT AF Josell, D Cezairliyan, A vanHeerden, D Murray, BT TI Thermal diffusion through multilayer coatings: Theory and experiment SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID FILMS AB A computationally simple, integral solution for heat transfer through periodic multilayer materials is used to analyze the results of pulse-heating experiments conducted near 1200 K. Experimental results obtained on 19 mu m thick coatings with 10 bilayers of Cu and Fe and on 12 mu m thick coatings with 10 and 40 bilayers of aluminum oxide and Mo, all deposited on 75 mu m thick Mo substrates, are presented. The source of reduced thermal conductivity in multilayer materials is examined. (C) 1997 Acta Metallurgica Inc. RP Josell, D (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 15 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 727 EP 736 DI 10.1016/S0965-9773(97)00159-1 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900148 ER PT J AU Beck, R Zettlmeissl, H Mossner, S Brunner, H Wolf, HU AF Beck, R Zettlmeissl, H Mossner, S Brunner, H Wolf, HU TI Analytical proof of potential neurotoxins occurring in serum of patients with idiopathic Parkinson's disease SO NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY LA English DT Meeting Abstract C1 UNIV ULM,ABT PHARMAKOL & TOXIKOL,D-89069 ULM,GERMANY. UNIV ULM,ABT NEUROL,RKU,D-89081 ULM,GERMANY. NATL INST STAND & TECHNOL,ANAL CHEM DIV,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0028-1298 J9 N-S ARCH PHARMACOL JI Naunyn-Schmiedebergs Arch. Pharmacol. PY 1997 VL 355 IS 4 SU S BP 544 EP 544 PG 1 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA WV420 UT WOS:A1997WV42000567 ER PT J AU Edmunds, JSG Fairey, ER Ramsdell, JS AF Edmunds, JSG Fairey, ER Ramsdell, JS TI A rapid and sensitive high throughput reporter gene assay for estrogenic effects of environmental contaminants SO NEUROTOXICOLOGY LA English DT Article; Proceedings Paper CT 13th International Neurotoxicology Conference on Developmental Neurotoxicity of Endocrine Disrupters - Dioxins, PCBs, Pesticides and Metals CY OCT 29-NOV 01, 1995 CL HOT SPRINGS, AR SP Agcy Tox Subst & Dis Registry, Natl Ctr Environm Assessment, Natl Hlth & Environm Effects Res Lab, US EPA, NIH, NIEHS, Cranmer & Assoc Inc, Eastman Kodak Co, Environm Hlth Fdn, Redfield Labs, TSI Genzyme Transegen, Univ Arkansas Med Sci, Arkansas Childrens Hosp, US FDA, Natl Ctr Toxicol Res DE endocrine disrupters; estrogen; reporter gene; DDT; PCBs ID POLYCHLORINATED-BIPHENYLS; BREAST-CANCER; RECEPTOR; CELLS; DDT; RAT; BINDING; GROWTH; PCBS AB We have developed an estrogen sensitive reporter gene assay and report here on its responsiveness to steroid hormones and several estrogenic contaminants, including pesticides and polychlorinated biphenyls (PCBs). GH(4)C(1) rat pituitary cells were stably transfected with the reporter gene ERE-TK-Luc which contains a luciferase gene under the transcriptional regulation of the Xenopus vitellogenin estrogen response element (ERE) and clones stably expressing ERE-TK-Luc were isolated. The sensitivity of the assay was determined by dose response with the endogenous ligand (17)beta-estradiol. An EC50 of 4.5 +/- 1.2 x 10(-11) M was determined for this compound. Natural and synthetic hormones such as dexamethasone, aldosterone, and thyroxine did not induce luciferase activity, whereas 10(-8) M diethylstilbestrol induced luciferase activity to a maximal equal to (17)beta-estradiol, indicating that transcription of the luciferase gene is primarily regulated through the endogenous estrogen receptors. The pesticide o,p'-DDT was found to be estrogenic at concentrations as low as 10(-7) M. Of the three PCBs assayed, 2',4',6'-trichlorobiphenyl and its hydroxylated metabolite 4OH-2',4:6'-trichlorobiphenyl were estrogenic at 10(-7) M, whereas 2,4,4'-trichlorobiphenyl did not induce luciferase activity. Lastly, the GH(4)C(1) ERE-Luc reporter gene assay was modified to utilize a cell permeant luciferin and 96 well format suitable for multiple and complex samples and generation of detailed dose response data. (C) 1997 Inter Press, Inc. C1 MED UNIV S CAROLINA, US NATL MARINE FISHERIES SERV, MARINE BIOTOXINS PROGRAM, CHARLESTON, SC 29412 USA. FU NIDDK NIH HHS [DK 43107] NR 30 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0161-813X J9 NEUROTOXICOLOGY JI Neurotoxicology PY 1997 VL 18 IS 2 BP 525 EP 532 PG 8 WC Neurosciences; Pharmacology & Pharmacy; Toxicology SC Neurosciences & Neurology; Pharmacology & Pharmacy; Toxicology GA XU979 UT WOS:A1997XU97900021 PM 9291500 ER PT B AU Prask, HJ Brand, PC AF Prask, HJ Brand, PC BE Vourvopoulos, G TI Residual stress determination by means of neutron diffraction SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Neutron diffraction is becoming an increasingly important tool for the determination of triaxial residual stress distributions for materials science and engineering applications. Indeed, virtually all of the major neutron centers in the world have, or are planning, programs in this area. In this paper the basic principles of the technique will be described, along with advantages and limitations relative to other nondestructive residual stress (strain) measurement methods. Examples of the application of the technique to sub-surface residual stress determination in metals and composites will be presented, along with some near-surface results. The significant features of new neutron instruments for residual stress study will be summarized. RP Prask, HJ (reprint author), NIST,MAT SCI & ENGN LAB,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 0 TC 9 Z9 9 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 106 EP 115 DI 10.1117/12.267879 PG 10 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00020 ER PT B AU ChenMayer, HH Lamaze, GP Mildner, DFR Downing, RG AF ChenMayer, HH Lamaze, GP Mildner, DFR Downing, RG BE Vourvopoulos, G TI Neutron depth profiling of elemental concentration using a focused beam SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Neutron Depth Profiling (NDP) is a non-destructive analytical technique for measuring the concentration of certain light elements as a function of depth near the surface (< 10 mu m) of a solid matrix. The concentration profile (resolution from 15 nm to 1 mu m) is determined by analyzing the energy spectrum of the charged particles emitted as a result of neutron capture by the elements. The measurement sensitivity is directly proportional to the neutron beam current density. A more intense neutron beam achieved by focusing improves sensitivity for specimens of small area. In addition, a narrowly focused beam adds lateral spatial resolution to the technique, which is advantageous compared with that obtained by collimating the beam size using apertures. Capillary neutron lenses have been shown to focus a neutron beam to sub-millimeter spot size. Preliminary tests have been performed in the NDP geometry using such a focusing device. A lateral resolution in the sub-millimeter range is demonstrated by a specimen of non-uniform lateral distribution composed of a row of borosilicate glass fibers. RP ChenMayer, HH (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 0 TC 2 Z9 2 U1 1 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 140 EP 143 DI 10.1117/12.267885 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00026 ER PT J AU Damineli, A Conti, PS Lopes, DF AF Damineli, A Conti, PS Lopes, DF TI Eta Carinae: A long period binary? SO NEW ASTRONOMY LA English DT Article DE stars: individual: eta Carinae; binaries; stars: early type; stars: evolution ID O-TYPE STARS; STELLAR CONTENT; X-RAYS; VARIABILITY; EVOLUTION; NEBULA AB We present new observations of eta Carinae, strongly suggesting that it is a binary system. High dispersion measurements of the broad Pay emission line show periodic radial velocity variations that are nicely explained by a star in a highly eccentric orbit. Velocity characteristics of the system imply massive components, in accord with the luminosity and spectral characteristics. Strong and variable wind-wind interactions are predicted to take place in eta Car on the basis of the orbital elements and physical characteristics of the components. The low excitation event predicted for the end of 1997 is underway, confirming the high coherence of the 5.52 year cycle and adding confidence to eta Car as a binary system. We associate this event with periastron passage. A conclusive demonstration of the binary orbit is still pending, but the present work has the advantages of bringing this mysterious object within a stellar evolution framework, and, for the first time in its history, predictions suitable for testing against future observations. (C) 1997 Elsevier Science B.V. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. OBSERV NACL, BR-20921440 RIO DE JANEIRO, BRAZIL. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. UNIV SAO PAULO, INST ASTRON & GEOFIS, BR-05508 SAO PAULO, BRAZIL. RI Damineli, Augusto/D-8210-2012 OI Damineli, Augusto/0000-0002-7978-2994 NR 33 TC 151 Z9 151 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1076 EI 1384-1092 J9 NEW ASTRON JI New Astron. PY 1997 VL 2 IS 2 BP 107 EP 117 DI 10.1016/S1384-1076(97)00008-0 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XB084 UT WOS:A1997XB08400002 ER PT B AU Kashiwagi, T Gilman, JW McGrath, JE Wan, IY AF Kashiwagi, T Gilman, JW McGrath, JE Wan, IY GP FIRE RETARDANT CHEM ASSOC TI Flammability properties of phosphine oxide copolymers and of commodity polymers with new flame retardant additives SO NEW DEVELOPMENTS AND FUTURE TRENDS IN FIRE SAFETY ON A GLOBAL BASIS - INTERNATIONAL CONFERENCE LA English DT Proceedings Paper CT 1997 Spring International Conference of the Fire-Retardant-Chemicals-Association - New Developments and Future Trends on a Global Basis CY MAR 16-19, 1997 CL SAN FRANCISCO, CA SP Fire Retardant Chem Assoc AB Several different phosphine oxides, triphenylphosphine oxide, diphenylphosphine oxide, and trihydroxylpropylphosphine oxide, are added into nylon 6,6 by copolymerization and by blending. The flammability properties of these samples are measured in the Cone Calorimeter. The results show that the addition of any of these phosphine oxides to nylon 6,6 reduces the heat release rate significantly but increases the amount of CO and soot particles. Although small amounts of char are formed with the phosphine oxides, the flame retardant site appears to be mainly in the gas phase. No significant difference in flammability properties is observed between the copolymer samples and the blended sample. A small quantity of silica gel with K2CO3 as an additive reduces heat release rate of many different polymers and forms carbonaceous char for PP, PMMA, nylon 6,6 and also significantly enhances char yields of cellulose and PVA. The solid-state NMR data of char formed from PVA with silica gel/K2CO3 show increase in aromaticity in the char compared with in the char generated from PVA only. RP Kashiwagi, T (reprint author), NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU FIRE RETARDANT CHEMICALS ASSOC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 PY 1997 BP 197 EP 219 PG 23 WC Chemistry, Applied; Polymer Science SC Chemistry; Polymer Science GA BH83T UT WOS:A1997BH83T00019 ER PT J AU Ehler, CN Cicin-Sain, B Knecht, R South, R Weiher, R AF Ehler, CN Cicin-Sain, B Knecht, R South, R Weiher, R TI Guidelines to assist policy makers and managers of coastal areas in the integration of coastal management programs and national climate-change action plans SO OCEAN & COASTAL MANAGEMENT LA English DT Article AB In response to potential commitments and obligations under the United Nations Framework Convention on Climate Change (UNFCCC), many nations are preparing national climate change action plans that identify management strategies to reduce greenhouse gas emissions and to adapt to the potential impacts of long-term climate change. The successful implementation of these plans and their management strategies within individual countries will depend to a large measure on the extent of their integration into the implementation of other national and sectoral management plans, including coastal management plans. This document provides guidance on integrating coastal management programs and national climate-change action plans. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NOAA, Silver Spring, MD 20910 USA. Univ Delaware, Newark, DE 19716 USA. Univ S Pacific, Suva, Fiji. RP Ehler, CN (reprint author), NOAA, Silver Spring, MD 20910 USA. NR 15 TC 7 Z9 7 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0964-5691 J9 OCEAN COAST MANAGE JI Ocean Coastal Manage. PY 1997 VL 37 IS 1 BP 7 EP 27 DI 10.1016/S0964-5691(97)00049-5 PG 21 WC Oceanography; Water Resources SC Oceanography; Water Resources GA ZM705 UT WOS:000073567600003 ER PT B AU Subramaniam, A Waters, K Armstrong, E Brock, J Ranheim, R AF Subramaniam, A Waters, K Armstrong, E Brock, J Ranheim, R BE Ackleson, SG Frouin, R TI Spatial variability in optical properties of the waters around the Ambrose light tower SO OCEAN OPTICS XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ocean Optics XIII CY OCT 22-25, 1996 CL HALIFAX, CANADA SP USN, Off Naval Res, NASA, Russian Acad Sci, Amer Geophys Union, Oceanog Soc, US, Amer Soc Limnol & Oceanog, Bedford Inst Oceanog, Canada, Def Res Estab Valcartier, Canada, Alliance Marine Remote Sensing, Canada DE Hudson river plume; New York Bight Apex; Ambrose light tower; spatial variability; coastal water optics; validation of case II algorithms; absorption; attenuation; reflectance difference; AVHRR AB The Ambrose Light Tower, situated at the New York Eight Apex near the entrance to New York Harbor, will be equipped with a suite of optical instruments designed to make high temporal resolution optical measurements. The resulting measurements of subsurface upwelling radiance and downwelling irradiance, spectral absorption and attenuation will be used to validate algorithms for retrieval of chlorophyll biomass and k490 from satellite data in case II waters. The Hudson River, a major source of freshwater to the coastal ocean of the northeastern United States flows into the New York Eight Apex and has a very well defined buoyant freshwater plume that can be as large as 500 km(2). Optical measurements of spectral absorption, attenuation, upwelling radiance and downwelling irradiance were made across the plume during a cruise in May 1996 during a period of high discharge. These showed that there was a 5 fold increase in absorption and attenuation inside the plume. The plume could be seen in reflectance difference images constructed using bands 1 and 2 of the AVHRR. RP Subramaniam, A (reprint author), NOAA,COASTAL SERV CTR,TECHNOL PLANNING & MANAGEMENT CORP,2234 HOBSON AVE,CHARLESTON,SC 29405, USA. OI Subramaniam, Ajit/0000-0003-1316-5827 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2367-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2963 BP 543 EP 548 DI 10.1117/12.266500 PG 4 WC Oceanography; Optics SC Oceanography; Optics GA BH31C UT WOS:A1997BH31C00086 ER PT B AU Churnside, JH AF Churnside, JH BE Ackleson, SG Frouin, R TI Measurements of the attenuation coefficient of a lidar in the Southern California Bight SO OCEAN OPTICS XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ocean Optics XIII CY OCT 22-25, 1996 CL HALIFAX, CANADA SP USN, Off Naval Res, NASA, Russian Acad Sci, Amer Geophys Union, Oceanog Soc, US, Amer Soc Limnol & Oceanog, Bedford Inst Oceanog, Canada, Def Res Estab Valcartier, Canada, Alliance Marine Remote Sensing, Canada DE ocean optics; lidar; optical attenuation AB Measurements were made of the attenuation coefficient of the National Oceanographic and Atmospheric Administration (NOAA) lidar from a ship in the Southern California Eight in September 1995. The region from about 5 m to about 30 m in depth was covered. The laser was linearly polarized, and the receiver was operated with the same polarization, the orthogonal polarization, and a polarization angle of 45 degrees, so that the first three Stokes parameters of the scattered light can be estimated. RP Churnside, JH (reprint author), NOAA,ENVIRONM RES LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2367-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2963 BP 643 EP 647 DI 10.1117/12.266375 PG 3 WC Oceanography; Optics SC Oceanography; Optics GA BH31C UT WOS:A1997BH31C00102 ER PT B AU Shaw, PS Johnson, BC Hooker, SB Lynch, D AF Shaw, PS Johnson, BC Hooker, SB Lynch, D BE Ackleson, SG Frouin, R TI The SeaWiFS Quality Monitor - A portable field calibration light source SO OCEAN OPTICS XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ocean Optics XIII CY OCT 22-25, 1996 CL HALIFAX, CANADA SP USN, Off Naval Res, NASA, Russian Acad Sci, Amer Geophys Union, Oceanog Soc, US, Amer Soc Limnol & Oceanog, Bedford Inst Oceanog, Canada, Def Res Estab Valcartier, Canada, Alliance Marine Remote Sensing, Canada DE calibration; field instrument; portable source; radiometric source; SeaWiFS AB A portable and stable source, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Quality Monitor, has been developed for use as a field instrument. The source can be used with either radiance- or irradiance-measuring sensors to transfer the laboratory calibration to the field so that the stability of the sensors can be monitored during the experiment. Temperature-controlled silicon photodiodes with colored glass filters are used to monitor the stability of the SeaWiFS Quality Monitor. RP Shaw, PS (reprint author), NIST,OPT TECH DIV,GAITHERSBURG,MD 20899, USA. RI Hooker, Stanford/E-2162-2012 NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2367-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2963 BP 772 EP 776 DI 10.1117/12.266399 PG 3 WC Oceanography; Optics SC Oceanography; Optics GA BH31C UT WOS:A1997BH31C00123 ER PT B AU Waters, K Brock, J Subramaniam, A Stumpf, R Armstrong, E AF Waters, K Brock, J Subramaniam, A Stumpf, R Armstrong, E BE Ackleson, SG Frouin, R TI Satellite assessment of hurricane-induced ocean turbidity for the southern US coastline SO OCEAN OPTICS XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ocean Optics XIII CY OCT 22-25, 1996 CL HALIFAX, CANADA SP USN, Off Naval Res, NASA, Russian Acad Sci, Amer Geophys Union, Oceanog Soc, US, Amer Soc Limnol & Oceanog, Bedford Inst Oceanog, Canada, Def Res Estab Valcartier, Canada, Alliance Marine Remote Sensing, Canada DE AVHRR; turbidity; hurricane AB Advanced Very High Resolution Radiometer images before and after three hurricanes were processed to estimate the reflectance difference between visible and near-infrared bands. The reflectance difference provides a measure of the turbidity in the water column. The images were compared to examine the influence of hurricanes on coastal waters. Hurricanes were found to increase turbidity in a large area, with the greatest impact to the right side of the hurricane track. RP Waters, K (reprint author), NOAA,TPMC,COASTAL SERV CTR,2234 S HOBSON AVE,CHARLESTON,SC 29405, USA. OI Subramaniam, Ajit/0000-0003-1316-5827 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2367-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2963 BP 892 EP 897 DI 10.1117/12.266410 PG 2 WC Oceanography; Optics SC Oceanography; Optics GA BH31C UT WOS:A1997BH31C00142 ER PT J AU Maul, GA Bushell, MH Bravo, NJ Hansen, DV AF Maul, GA Bushell, MH Bravo, NJ Hansen, DV TI Observed sea surface height and modeled dynamic height anomaly departures in the tropical Pacific Ocean: 1986-1989 SO OCEANOLOGICA ACTA LA English DT Article ID DATA ASSIMILATION SYSTEM; EQUATORIAL PACIFIC; GEOSAT ALTIMETRY; CLIMATE FORECAST; LEVEL; WAVES; VARIABILITY AB Observations of sea surface height departure (SSH') from November 1986 through September 1989 in the tropical Pacific from the improved (T2) GEOSAT data set (Cheney et al., 1991) are compared with monthly mean dynamic height anomaly departure (Delta D') from the ''second reanalysis'' using the NOAA ocean analysis system (Ji et al., 1994, 1995). For comparisons, Delta D' is calculated by removing north-south tilt and bias as in SSH orbit error removal, giving standard deviation fields sigma(SSH') and sigma(Delta D') that quantitatively reproduce variability of the North Equatorial Current (NEC)/North Equatorial Countercurrent (NECC)/South Equatorial Current (SEC) system between El Nino and non-El Nino years. Hovmoller diagrams of SSH' and Delta D' variability at 110 degrees W, 140 degrees W, 170 degrees W, and 165 degrees E between 20 degrees S and 20 degrees N, and along the equator from 120 degrees E to 80 degrees W, display the amplitude and phase of the 1986-1987 El Nino-Southern Oscillation (ENSO) event as distinguished from the years following, with the NECC significantly weakened in 1987 as compared to 1988. Cross-correlations (r) between Delta D' and SSH' are highest near the Equator in the vicinity of the TOGA-TAO (Hayes et al., 1991; McPhaden, 1993) in situ mooring arrays, with values above r = 0.7 in much of the region +/- 7 degrees of the Equator across about half of the Pacific basin. Differences between Delta D' and SSH' are typically less than +/- 5 cm RMS in this same equatorial band, but there are two regions of differences in excess of +/- 15 cm RMS: off Central America and east of New Guinea. The reason for these large RMS differences is uncertain, but it is inferred from Lagrangian buoy data that intense eddy activity is unresolved in the model as compared to GEOSAT. For the 35 monthly realizations, the ensemble cross correlation r = 0.5 has +/- 7 cm RMS within +/- 15 degrees of the Equator, and peaks in 1988 with decay towards the end of the GEOSAT Exact Repeat Mission (ERM) in September 1989. Seasonally, both SSH' and Delta D' show that the boreal winter (DJF) of 1987 is dominated by the ENSO-related sea level maximum in mid-basin, which is absent in the following two winters; spring (MAM) and summer (JJA) of all three years have little resemblance to each other, with 1987 and 1989 being more similar than 1988; autumn (SON) of 1988 shows a well developed NECC across much of the eastern Pacific centered at similar to 7 degrees N. The ERM altimeter data and the model calculations of the annual cycle both show east-west height amplitude maxima along 5 degrees N and 10 degrees N that explain more than 50% of the variance for a substantial portion of the central Pacific Ocean. Concurrent drogued buoy tracks show more eddies centered along similar to 5 degrees N in the eastern Pacific in 1988 as compared to 1987 or 1989, but Delta D' is unable to resolve these features. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. UNIV MIAMI,COOPERAT INST MARINE & ATMOSPHER STUDIES,MIAMI,FL 33149. RP Maul, GA (reprint author), FLORIDA INST TECHNOL,150 W UNIV BLVD,MELBOURNE,FL 32901, USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 45 TC 2 Z9 2 U1 0 U2 0 PU GAUTHIER-VILLARS PI PARIS PA 120 BLVD SAINT-GERMAIN, 75280 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PY 1997 VL 20 IS 4 BP 569 EP 584 PG 16 WC Oceanography SC Oceanography GA XU314 UT WOS:A1997XU31400001 ER PT B AU Woody, CE AF Woody, CE GP IEEE TI Voyage of the FRAM SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB Fridtjof Nansen was the first person to put forth the idea of Arctic circulation and to truly discover the Arctic Ocean basin. He based his hypothesis on the ill-fated ship JEANNETTE that was crushed by the ice in 1881 near the New Siberian Islands. The JEANNETTE, in trying to find a passage to the North Pole, entered the Bering Strait in 1879, was set in ice, and drifted for two years until she was crushed. Her remains were discovered in 1884 near Julienhaab on the southwest coast of Greenland. Nansen then hypothesized that this wreckage had been carried by a current flowing from the region of the New Siberian Islands, passing near the North Pole, and then descending southward to the North Atlantic along the east coast of Greenland. To verify this, Nansen executed the most remarkable expedition of the FRAM from 1893 to 1896 to study polar currents and the oceanography of the Arctic He built the FRAM so that when the ice set around her, she would be raised up onto the ice and drift with the ice pack He did this successfully in this most fascinating voyage of the Arctic. The following account is taken from Nansen's writings of his expeditions in FARTHEST NORTH, 1898. RP Woody, CE (reprint author), NATL DATA BUOY CTR,STENNIS SPACE CTR,MS 39529, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 40 EP 44 PG 5 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00009 ER PT B AU Broadwater, JD Hill, DB Johnston, J Kozlowski, K AF Broadwater, JD Hill, DB Johnston, J Kozlowski, K GP IEEE TI Applying modern technology to save a historic warship: The Monitor National Marine Sanctuary SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB On March 9, 1862 the ironclad warships USS Monitor and CSS Virginia (ex-USS Merrimack) fought to a draw at Hampton Roads, Virginia, in one of the most recognized sea battles in history. Now, 135 years later, the Monitor is fighting a losing battle against both natural and human threats. The Monitor's hull, lying in 230 ft. (71 m) of water off Cape Hatteras, North Carolina, is deteriorating at an alarming rate. The National Oceanic and Atmospheric Administration (NOAA) is responsible for the Monitor which, in 1975, was designated America's first National Marine Sanctuary. As a result, NOAA is aggressively applying comprehensive planning strategy and ocean technology to the problem of protecting the Monitor. RP Broadwater, JD (reprint author), NOAA,NATL MARINE SANCTUARY,MARINERS MUSEUM,100 MUSEUM DR,NEWPORT NEWS,VA 23606, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 161 EP 166 PG 6 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00028 ER PT B AU Shih, HH Williams, R Sun, CL Popstefanija, LP AF Shih, HH Williams, R Sun, CL Popstefanija, LP GP IEEE TI Field experiment with an ocean surface current sensing microwave radar SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB Ocean surface current information in harbors, bays, and estuaries is important to navigation, environmental management, and other scientific studies. The need for an automated, remote current mapping instrument in such an environment has long been stressed by the oceanic community. To meet this need, a dual frequency (Delta-K) X-band microwave radar is being developed by Quadrant Engineering for the National Ocean Service (NOS). It differs from other commercially available surface current sensing radars in that it offers a much finer current resolution cell (100 m x 100 m) than HF/VHF radars, good velocity resolution (1-5 cm/sec) and can automatically transmit multiple frequencies (frequency agility) to adapt to varying surface wave conditions. This paper describes NOS needs, the basic principle and system parameters of Delta-K radar, and a field experiment conducted in January 8-9, 1997 at Newark Bay, New Jersey. The goal of the experiment was to demonstrate the feasibility of the radar system in measuring the surface currents in a harbor environment. Ocean surface conditions varied from rough to calm during the two-day period. The experiment showed that the Delta-K system provided good current signals in the harbor environment under two very different surface conditions. In-situ current measurements consisted of those from a Price current meter, surface drifters, and a bottom-mounted Acoustic Doppler Current Profiler (ADCP). The currents measured by Delta-K radar appear to be reasonable in both magnitude and its spatial-distribution. However, because of the uncertainties of the in-situ observations, no quantitative comparison was attempted. A more rigorous field evaluation test is being planned. RP Shih, HH (reprint author), NATL OCEAN & ATMOSPHER ADMIN,NATL OCEAN SERV,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 1013 EP 1018 PG 6 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00175 ER PT B AU Woody, CE Dagnall, R Michelena, E McGehee, D Bichner, G Mero, T AF Woody, CE Dagnall, R Michelena, E McGehee, D Bichner, G Mero, T GP IEEE TI Oceanographic test facility at Duck Pier, NC SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB The National Data Buoy Center (NDBC), U.S. Army Corps of Engineers (COE) Waterways Experiment Station (WES) and National Ocean Service (NOS) have established an environmental test facility for ocean and atmospheric sensors at the WES Field Research Facility (FRF) in Duck, NC. This facility provides a natural environmental laboratory for testing and evaluating sensors used for long-term, remote monitoring on platforms of opportunity. NDBC, NOS, and WES operate national scale-monitoring networks extending from estuaries through the coastal zone to offshore, each using its own unique platforms to accomplish agency missions. It is important that these platforms have the capability to accept additional sensors and can manage (process, qualify, store, and maintain) and disseminate the data in real time. The environmental test facility on the FRF pier is shared between the participating agencies. The new facility consists of an NDBC coastal weather station, two laboratories housing wet and dry laboratory facilities, an ocean platform for supporting sensors underwater, WES directional waves, water pressure, and current sensors, and a water level station operated by NOS. This facility will enable environmental managers and scientists to assess and evaluate the capabilities of environmental sensors to meet the requirements for accurate, reliable long-term unattended monitoring programs. RP Woody, CE (reprint author), NATL DATA BUOY CTR,STENNIS SPACE CTR,MS 39529, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 1094 EP 1098 PG 5 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00190 ER PT B AU Wilmot, WL Galt, JA Cheng, RT AF Wilmot, WL Galt, JA Cheng, RT GP IEEE TI Extensible physical oceanographic real-time system (PORTS) SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB NOAA's PORTS is a decision support system to facilitate safe and efficient maritime commerce and effective environmental resource management. PORTS is installed in Tampa Bay, New York/New Jersey Harbor, Houston/Galveston, and San Francisco Bay. PORTS consists of real-time observations of ocean conditions and weather, computer model nowcasts and forecasts of ocean fields, and dissemination of data via a telephone voice data response system and Internet. PORTS information ensures that an adequate margin of safety is available to larger and larger ships in channels which are being deepened but not significantly widened. PORTS provides information permitting shippers to load their vessels to take full advantage of real-time water levels and channel improvements. PORTS information guides hazardous materials spill prevention and response as well as effective ecosystem hearth management. The San Francisco Bay PORTS is the model for a future National PORTS. That model is an extensible PORTS based on an Information Hub Concept (InfoHub) which will permit PORTS to adapt to evolving user needs. The extensible PORTS provides standard sensor interfaces to encourage the addition of non-NOAA sensors to the system. A data base provides a broad user community with access through downloadable applications and applets on Internet. PORTS provides information broadcast to shipboard vector and raster Electronic Chart and Information Display Systems and a Lockheed Martin/Rensselaer Polytechnic Institute Navigation and Piloting Expert Systems (NPES). An open architecture design will encourage commercial and academic partners to participate in National PORTS development. RP Wilmot, WL (reprint author), US DEPT COMMERCE,NOAA,NATL OCEAN SERV,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 2 U2 3 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 1437 EP 1441 PG 5 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00253 ER PT B AU Galt, JA Cheng, RT Wilmot, WL AF Galt, JA Cheng, RT Wilmot, WL GP IEEE TI Current pattern analysis for oil-spills - A case study using San Francisco Bay SO OCEANS '97 MTS/IEEE CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT Oceans 97 MTS/IEEE Conference CY OCT 06-09, 1997 CL HALIFAX, CANADA SP IEEE Ocean Engn Soc, Marine Technol Soc AB During oil-spill events the movement and spreading of the pollutant is of critical interest to responders and there are always demands for forecasts of the future position of the oil. For floating portions of the spilled oil that are constrained to remain on the surface, the two-dimensional kinematics of the flow patterns can be used to identify locations for flotsam collection. In areas where there are strong ''flow convergencies'' a Lagrangian view shows the surface water moving towards a common region. As a result, the concentrations of floating material will increase where convergence zones are found. In coastal communities these areas are typically referred to as ''tidal rips'' or ''rips''. In some regions these convergence zones are persistent enough to have common names associated with them. The convergence zones are always areas for flotsam collection. A high-resolution now-casting numerical model has been implemented for San Francisco Bay to assist oil-spill prevention and response. Thirty-six hours of now-casting high-resolution numerical model results are available centered around the present time. The current patterns from these model results can be further analyzed to provide information that identifies areas of strong convergence. Results of this kinematic analysis can be used to identify likely collection areas for floating oil and to provide location maps for the effective placement of recovery equipment. Convergence zones are typically associated with barotropic flow over large bathymetry variations or density fronts at interfaces where oceanic and fresh water mix. These analysis techniques were further developed and tested in San Francisco Bay to strengthen local oil-spill response planning activities. During an actual spill caused by the Cape Mohican in San Francisco Bay (late October 1996), the planning response for clean up efforts and the development of insights on the movement of oil patches were enhanced by the results of the current pattern analysis. RP Galt, JA (reprint author), NOAA,NATL OCEAN SERV,HAZARDOUS MAT RESPONSE & ASSESSMENT DIV,SEATTLE,WA, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4108-2 PY 1997 BP 1448 EP 1452 PG 5 WC Acoustics; Engineering, Marine; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Instruments & Instrumentation; Oceanography; Remote Sensing SC Acoustics; Engineering; Geology; Instruments & Instrumentation; Oceanography; Remote Sensing GA BJ68T UT WOS:A1997BJ68T00255 ER PT B AU Pfeffer, LE Tran, HD AF Pfeffer, LE Tran, HD BE Proctor, FM TI Key characteristics for software for open architecture controllers SO OPEN ARCHITECTURE CONTROL SYSTEMS AND STANDARDS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Open Architecture Control Systems and Standards CY NOV 20-21, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers DE open architecture controllers; real-time systems; software standards; software reuse AB Software development time, cost, and ease of(re)use are now among the major issues in development of advanced machines, whether for machine tools (e.g. multi-axis machine took, coordinate measuring machines), automation systems (e.g. robotic assembly cells), or process systems (e.g. chemical or biochemical reactors.) Two keys to reducing development time (and facilitating reuse) are powerful, user-friendly development tools and software architectures that provide clean, well-documented interfaces to the various real-time functions that such machines require. Examples of essential functions are signal conditioning, servo-control, trajectory generation, calibration/registration, coordination of asynchronous events, task sequencing, communication with external systems, and user interfaces. There are a number of existing standards that can help with software development, such as the IEEE POSIX standards for operating systems and real time services; software took to compliment these standards are beginning to see use. This paper will detail some of the existing standards, some new tools, and development activities relevant to advanced, ''smart'' machines. RP Pfeffer, LE (reprint author), NATL INST STAND & TECHNOL,BFRL,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2314-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 2912 BP 36 EP 44 DI 10.1117/12.263376 PG 3 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BH07J UT WOS:A1997BH07J00004 ER PT B AU Lee, K Fronczek, L Gavin, R Schneeman, R AF Lee, K Fronczek, L Gavin, R Schneeman, R BE Proctor, FM TI PC-based machine-tool controller implemented as testbed for smart transducer interface SO OPEN ARCHITECTURE CONTROL SYSTEMS AND STANDARDS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Open Architecture Control Systems and Standards CY NOV 20-21, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers DE CNC; integration; machine tool; PC-based controller; sensor interface; open architecture AB Machine-tool controllers are traditionally proprietary in design. Therefore, it is difficult to integrate third party hardware or software to enhance the functionality of either the machine tool or its controller. An open-architecture, PC-based controller emerges as a good alternative. The Automated Production Technology Division at the National Institute of Standards and Technology, in collaboration with the U.S. Navy, implemented an open-architecture, PC-based controller. This paper describes the design, implementation, and integration of this controller into a vertical machining center on the Portsmouth Naval Shipyard shop floor. RP Lee, K (reprint author), NATL INST STAND & TECHNOL,MFG ENGN LAB,AUTOMATED PRODUCT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2314-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 2912 BP 64 EP 71 DI 10.1117/12.263379 PG 2 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BH07J UT WOS:A1997BH07J00007 ER PT B AU Szabo, S Proctor, F AF Szabo, S Proctor, F BE Proctor, FM TI Validation results of specifications for motion control interoperability SO OPEN ARCHITECTURE CONTROL SYSTEMS AND STANDARDS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Open Architecture Control Systems and Standards CY NOV 20-21, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers AB The National Institute of Standards and Technology (NIST) is participating in the Department of Energy Technologies Enabling Agile Manufacturing (TEAM) program to establish interface standards for machine tool, robot, and coordinate measuring machine controllers. At NIST, the focus is to validate potential application programming interfaces (APIs) that make it possible to exchange machine controller components with a minimal impact on the rest of the system. This validation is taking place in the Enhanced Machine Controller (EMC) Consortium and is in cooperation with users and vendors of motion control equipment. An area of interest is motion control, including closed-loop control of individual axes and coordinated path planning. Initial tests of the motion control APIs are complete. The APIs were implemented on two commercial motion control beards that run on two different machine tools. The results for a baseline set of APIs look promising, but several issues were raised. These include resolving differing approaches in how motions are programmed and defining a standard measurement of performance for motion control. This paper starts with a summary of the process used in developing a set of specifications for motion control interoperability. Next, the EMC architecture and its classification of motion control APIs into two classes, Servo Control and Trajectory planning, are reviewed. Selected APIs are presented to explain the basic functionality and some of the major issues involved in porting the APIs to other motion controllers. The paper concludes with a summary of the main issues and ways to continue the standards process. RP Szabo, S (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2314-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 2912 BP 166 EP 176 DI 10.1117/12.263367 PG 3 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BH07J UT WOS:A1997BH07J00016 ER PT S AU Parks, RE Evans, CJ Sullivan, PJ Shao, LZ Loucks, B AF Parks, RE Evans, CJ Sullivan, PJ Shao, LZ Loucks, B BE Stahl, HP TI Measurements of the LIGO pathfinder optics SO OPTICAL MANUFACTURING AND TESTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Manufacturing and Testing II CY JUL 27-29, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE optical testing; absolute testing; LIGO; interferometry AB A number of 150 mm apertures in 250 mm diameter plano-concave optics with departures from the nominal figure of a few nm were carefully tested using phase measuring interferometry and the data reduced using pixel based absolute testing techniques. We discuss some of the data reduction techniques used as well as the precautions taken to verify the accuracy of the results. After accounting for systematic errors introduced by interferometer imaging, we show that the surfaces can be characterized to a few nm peak-to-valley over spatial scales from the measurement aperture to a few mm. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Parks, RE (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 0 TC 16 Z9 16 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2556-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3134 BP 95 EP 111 DI 10.1117/12.295122 PG 3 WC Optics SC Optics GA BK19B UT WOS:000071451800011 ER PT S AU Parks, RE Evans, CJ Roderick, DJ Dagata, J AF Parks, RE Evans, CJ Roderick, DJ Dagata, J BE Stahl, HP TI Applications of the rapidly renewable lap SO OPTICAL MANUFACTURING AND TESTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Manufacturing and Testing II CY JUL 27-29, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE lapping; polishing; glasses; metals; ceramics AB The Rapidly Renewable Lap (RRL) is based on the simple concept of generating the figure needed In a lap substrate and then replicating it into a thin film slumped over the substrate. Based an this concept, we describe how efficient laps can be constructed for the lapping and polishing of crystalline, amorphous, and metallic surfaces. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Parks, RE (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2556-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3134 BP 240 EP 251 DI 10.1117/12.295130 PG 2 WC Optics SC Optics GA BK19B UT WOS:000071451800026 ER PT S AU Black, D Braun, L Burdette, H Evans, C Hockey, B Polvani, R White, G AF Black, D Braun, L Burdette, H Evans, C Hockey, B Polvani, R White, G BE Stahl, HP TI Using advanced diagnostics to detect subsurface damage in sapphire SO OPTICAL MANUFACTURING AND TESTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Manufacturing and Testing II CY JUL 27-29, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE sapphire; sub-surface damage; x-ray topography; transmission electron microscopy; photoelasticity; Raman spectroscopy; wavefront analysis AB The microstructure of sapphire modulus of rupture (MOR) bars has been examined before and after a high-temperature anneal using a variety of characterization methods, collectively described as "advanced diagnostics". These methods include the localized techniques of transmission electron microscopy (TEM), Raman spectroscopy and high magnification polarized light microscopy, as well as the global techniques of x-ray diffraction topography, polariscope and wave front analysis. Comparison of data before and after annealing indicate that no change has occurred in the long-range strain distribution or subgrain structure. However, changes in microstructure consistent with the motion of dislocations within similar to 100 nm of the surface were observed. C1 NIST, Gaithersburg, MD 20899 USA. RP Black, D (reprint author), NIST, 223-A163, Gaithersburg, MD 20899 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2556-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3134 BP 272 EP 283 DI 10.1117/12.295133 PG 2 WC Optics SC Optics GA BK19B UT WOS:000071451800029 ER PT B AU Wilson, CL Watson, CI Paek, EG AF Wilson, CL Watson, CI Paek, EG BE Casasent, DP Chao, TH TI Combined optical and neural network fingerprint matching SO OPTICAL PATTERN RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition VIII CY APR 22-23, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers AB This paper presents results on direct optical matching of inked and real-time fingerprint images. Direct optical correlations and hybrid optical neural network correlation are used in the matching system for inked fingerprints. Preliminary results on optical matching of real- time fingerprints use optical correlation. The test samples used in the inked image experiments are the fingerprint taken from NIST database SD-9. These images, in both binary and gray level forms, are stored in a VanderLugt correlator [1]. Tests of typical cross correlations and auto correlation sensitivity for both binary and 8 bit gray images are presented. When global correlations are tested on a second inked image results are found to be strongly influenced by plastic distortion of the finger. When the correlations are used to generate features that are localized to parts of each fingerprint and combined using a neural network classification network and separate class-by-class matching networks, 84.3% matching accuracy is obtained on a test set of 100,000 image pairs. Initial results with real-time images suggest that the difficulties resulting from finger deformation can be avoided by combining many different distorted images when the hologram is constructed in the correlator. Testing this process will require analysis of 10-20 second sequences of digital video. RP Wilson, CL (reprint author), NIST,INFORMAT TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 35 Z9 35 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2488-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3073 BP 373 EP 382 DI 10.1117/12.270385 PG 4 WC Optics SC Optics GA BH52H UT WOS:A1997BH52H00038 ER PT S AU Paek, EG Choe, JY Oh, TK AF Paek, EG Choe, JY Oh, TK BE Wang, SY Park, YS TI Acoustically steered and rotated (ASTRO) optoelectronic 2-D true-time-delay generation SO OPTOELECTRONIC INTEGRATED CIRCUITS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Optoelectronic Integrated Circuits II Conference (OEIC II) CY JAN 28-30, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical interconnection; phased array antennas; true time delays; beam steering; Fiber Bragg gratings; acousto-optic beam deflectors; optical information processing; optoelectronics; wavelength division multiplexing AB A new 2-D true time delay (TTD) generation system architecture for phased array antennas is described. The method uses fiber chirp gratings and acousto-optic beam deflectors. By combining free-space optics and guided optics, the device complexity in conventional TTD systems has been significantly reduced. A proof-of-concept experimental results are demonstrated. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Paek, EG (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2729-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 3290 BP 364 EP 371 DI 10.1117/12.298259 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BK25Z UT WOS:000071633100038 ER PT B AU Rose, AH Rochford, KB AF Rose, AH Rochford, KB BE Hatheway, AE TI Packaging hygroscopic and stress-sensitive optics for a standard retarder SO OPTOMECHANICAL DESIGN AND PRECISION INSTRUMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optomechanical Design and Precision Instruments CY JUL 31-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE optical packaging and design; hygroscopic glass; stress induced birefringence; permeability AB We discuss the packaging of a standard retarder. The retarder is a double Fresnel rhomb device and we have achieved retardance stability within +/-0.1 degrees over a +/-20 degrees C temperature range. We estimated a 10 year lifetime for storage within normal laboratory temperature and humidity conditions. The retardance of an optical rhomb retarder is sensitive to stress-induced birefringence. We selected a glass with a low stress-optic coefficient to improve optical performance. However, the glass is hygroscopic, and the retardance of the device changes in the presence of water vapor. Thus, for a stable retardance, a package as nearly hermetic to water as possible that does not introduce any stress birefringence is required. We have tested the permeability of the seals, the sensitivity of our optical device to water vapor, and predicted a usable lifetime for the retarder. We discuss the optical materials, water permeability of seal materials and the mathematical models used to predict the lifetime of the device. Also, we discuss the optical design and retarder's placement in the package to minimize stress induced birefringence. RP Rose, AH (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECT,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2554-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 3132 BP 120 EP 126 DI 10.1117/12.279097 PG 7 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78L UT WOS:A1997BJ78L00013 ER PT S AU Lawson, JR AF Lawson, JR BE Stull, JO Schwope, AD TI Fire fighters' protective clothing and thermal environments of structural fire fighting SO PERFORMANCE OF PROTECTIVE CLOTHING, 6TH VOLUME SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 6th International Symposium on Performance of Protective Clothing - Emerging Protection Technologies CY JUN 18-19, 1996 CL ORLANDO, FL SP Amer Soc Testing & Mat, Comm F23 Protect Clothing DE environments; fires; fire fighters; heat transfer; injuries; protective clothing; structures; thermal insulation AB Fire fighters' protective clothing is designed to perform several functions. Of these, protection from heat and flame is one of the most important. Today's fire fighter protective clothing designs are based on years of field experience and research studies which addressed structural fires. Much of this work has concentrated on the fire environment where a fire fighter suddenly becomes enveloped in flames. This exposure generally results in serious life threatening injuries and sometimes death. Little appears to have been done to address the conditions where most burn injuries occur, outside of the flaming envelope. This paper attempts to define the general thermal environment at locations where fire fighters stage and begin their attack on a fire. A great deal of research has been done to evaluate structural fires as they relate to building design, materials and contents. Only small elements of these data have been used in evaluating the thermal environment around fire fighters during normal attack situations. Results from early and recent studies clearly demonstrate the severity of thermal environments at fire attack staging areas. The flow of hot gases from a doorway or through a window may be well above 400 degrees C (752 degrees F) and may extend tens of meters down a corridor or across an adjoining room ceiling. Thermal radiation from a room's open doorway or window may reach levels which will cause burn injuries to exposed skin and cause charring or ignition of protective clothing fabrics which result in burn injuries to protected skin. Surface temperatures of solids within this staging zone may easily exceed 100 degrees C (212 degrees F), and touching these surfaces without protection could result in a sudden burn injury. A brief scenario is presented which serves as an example of how a fire fighter could receive second degree burns while attacking a fire from outside of the flaming envelope. RP Lawson, JR (reprint author), NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 6 Z9 7 U1 0 U2 4 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 SN 1071-5827 BN 0-8031-2402-3 J9 AM SOC TEST MATER PY 1997 VL 1273 BP 334 EP 352 DI 10.1520/STP19915S PG 19 WC Materials Science, Multidisciplinary; Materials Science, Textiles SC Materials Science GA BJ84B UT WOS:A1997BJ84B00028 ER PT B AU Mofjeld, HO Gonzalez, FI Newman, JC AF Mofjeld, HO Gonzalez, FI Newman, JC BE Hebenstreit, G TI Short-term forecasts of inundation during Teletsunamis in the eastern north Pacific Ocean SO PERSPECTIVES ON TSUNAMI HAZARD REDUCTION: OBSERVATIONS, THEORY AND PLANNING SE ADVANCES IN NATURAL AND TECHNOLOGICAL HAZARDS RESEARCH LA English DT Proceedings Paper CT 17th International Tsunami Symposium on Perspectives on Tsunami Hazard Reduction as Part of the XXI General Assembly of the IUGG CY JUL, 1995 CL BOULDER, CO SP Int Union Geodesy & Geophys, Tsunami Commiss, Int Assoc Seismol & Phys Earths Interior AB It is found empirically that, at tide gauges in the eastern North Pacific, later waves in a teletsunami are bounded in amplitude by envelopes that can be determined from observations of earlier waves at the same site. This is illustrated using the teletsunami generated by the 4 October 1994 Shikotan earthquake. The envelopes have the form eta(t)=A sigma(T) in which t is the time since the local onset of the tsunami and sigma(T) is the standard deviation of the tsunami-band fluctuations that are observed in a time interval T immediately preceding t. For t less than or equal to 10 hr, T = t+2 hr and T = 12 hr thereafter. Values for the multiplicative factor A = 3.0 and the temporal parameters for T were determined by tuning the envelope to several teletsunamis. In principle, such envelopes can be extrapolated forward in time and added to predictions of background water levels to forecast the maximum elevations of tsunami waves that might occur during the next few hours. However, several issues need to be addressed before such a scheme can be used operationally. These include the choice of inundation thresholds that are appropriate for tsunamis and the spatial distribution of gauges needed to adequately monitor tsunami waves in a region. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Mofjeld, HO (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Newman, Jean/K-6638-2015 NR 0 TC 9 Z9 9 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4811-7 J9 ADV NAT TECHNOL HAZ PY 1997 VL 9 BP 145 EP 155 PG 11 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA BK12C UT WOS:000071241800010 ER PT B AU Bernard, EN AF Bernard, EN BE Hebenstreit, G TI Reducing Tsunami hazards along US coastlines SO PERSPECTIVES ON TSUNAMI HAZARD REDUCTION: OBSERVATIONS, THEORY AND PLANNING SE ADVANCES IN NATURAL AND TECHNOLOGICAL HAZARDS RESEARCH LA English DT Proceedings Paper CT 17th International Tsunami Symposium on Perspectives on Tsunami Hazard Reduction as Part of the XXI General Assembly of the IUGG CY JUL, 1995 CL BOULDER, CO SP Int Union Geodesy & Geophys, Tsunami Commiss, Int Assoc Seismol & Phys Earths Interior AB On April 25-26, 1992, a swarm of large earthquakes rattled northern California, injuring 98 people and causing $66 million dollars in damage. The swarm began with a M-S 7.1 thrust earthquake that generated a small tsunami recorded at tide stations in California, Oregon, and Hawaii. This earthquake/tsunami event provided important evidence that the Cascadia Subduction Zone is seismically active and that tsunamis are likely from earthquakes occurring along the zone. This new evidence also led the National Oceanic and Atmospheric Administration (NOAA), the U.S. agency responsible for tsunami warnings, to evaluate the state of tsunami preparedness for communities potentially affected. NOAA conducted workshops on tsunami hazard assessment, tsunami warnings, and public education over a 15-month period. Over 50 tsunami scientists, emergency planners, and educators participated and produced technical reports with findings and recommendations. The most significant findings that emerged from these workshops include: 1. Technology exists to produce tsunami inundation maps for emergency preparedness. 2. Technology exists to issue tsunami warnings within 5 minutes for earthquakes occurring along U.S. coastlines. 3. Technology exists to detect tsunamis in the offshore ocean. 4. Tsunami education for local and distant tsunami is deficient for west coast decision makers and residents. A summary of the three workshops is presented in this report, along with 12 recommendations that participants felt would mitigate U.S. tsunami hazards. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Bernard, EN (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 0 TC 3 Z9 3 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4811-7 J9 ADV NAT TECHNOL HAZ PY 1997 VL 9 BP 189 EP 203 PG 15 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA BK12C UT WOS:000071241800013 ER PT B AU Ohno, Y Zong, YQ AF Ohno, Y Zong, YQ BE Arecchi, AV TI Establishment of the NIST flashing light photometric unit SO PHOTOMETRIC ENGINEERING OF SOURCES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photometric Engineering of Sources and Systems CY JUL 29-30, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE anticollision light; calibration; flashing light; flash photometer; effective intensity; illuminance; luminous exposure; strobe light; photometry; standards AB There is a need for accurate measurement of flashing lights for the proper maintenance of aircraft anticollision lights. A large variation in the measured intensities of anticollision lights has been a problem, and thus, NIST has undertaken the task to establish flashing-light photometric standards to provide calibration services in this area. A flashing-light photometric unit (lux second, [lx.s]) has been realized based on the NIST detector-based candela, using four standard photometers equipped with current integrators. Two different approaches have been taken to calibrate these standard photometers: one based on electrical calibration of the current integrator, and the other based on electronic pulsing of a steady-state photometric standard. The units realized using these two independent methods agreed to within 0.2 %. The relative expanded uncertainty (k=2) of the standard photometers, in the measurement of the white xenon flash, is estimated to be 0.6 %. The standard photometers are characterized for temporal response, linearity, and spectral responsivity, to be used for measurement of xenon flash sources of various waveforms and colors. Calibration services have been established at NIST for flashing-light photometers with white and red anticollision lights. RP Ohno, Y (reprint author), NIST,A320 METROL,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2562-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3140 BP 2 EP 11 DI 10.1117/12.284086 PG 10 WC Optics SC Optics GA BJ67Q UT WOS:A1997BJ67Q00001 ER PT B AU Shaw, PS AF Shaw, PS BE Arecchi, AV TI Simulation of a compact large-area radiometric light source SO PHOTOMETRIC ENGINEERING OF SOURCES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photometric Engineering of Sources and Systems CY JUL 29-30, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE radiometric source; large-area light source; SeaWiFS; light source simulation AB The performance of a novel compact large-area radiometric light source (CLARLS) has recently been demonstrated by the SeaWiFS ( Sea-viewing Wide Field-of-View Sensor) Quality Monitor built for the SeaWiFS Calibration and Validation Program. The SeaWiFS Quality Monitor (SQM) was successfully used as a calibration source onboard two trans-Atlantic cruises. The success of the CLARLS relies mostly on the uniformity of optical radiance it provides for sensor calibration. A theory to model the uniformity must account for the light scattering inside its light chamber. Here, such a model is proposed and the results of the numerical simulation are discussed. RP Shaw, PS (reprint author), NIST,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2562-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3140 BP 30 EP 35 DI 10.1117/12.284092 PG 6 WC Optics SC Optics GA BJ67Q UT WOS:A1997BJ67Q00004 ER PT J AU Kim, YK AF Kim, YK TI Strengths and weaknesses of relativistic atomic structure calculations SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 8th International Conference on the Physics of Highly Charged Ions (HCI-96) CY SEP 23-26, 1996 CL OMIYA, JAPAN ID MANY-BODY CALCULATIONS; N=2 STATES; C-III; ENERGIES; IONS; TRANSITIONS; URANIUM AB Among the relativistic atomic structure theories developed in the last two decades, two methods - multiconfiguration Dirac-Fock (MCDF) and relativistic many-body perturbation theory (RMBPT) - have extensively been applied to calculate spectroscopic properties of neutral atoms as well as highly charged ions. The strengths and weaknesses of these methods are discussed with some examples. The MCDF method is based on the shell structure familiar to atomic physicists, and hence intuitively easier to understand, On the other hand, the RMBPT method is more systematic in introducing correlation and relativistic corrections and logically simpler to include quantum electrodynamic (QED) corrections and higher order relativistic effects than the MCDF method. A recent development in extensive relativistic configuration interaction is also described. RP Kim, YK (reprint author), NIST, BLDG 221, RM A267, GAITHERSBURG, MD 20899 USA. NR 25 TC 11 Z9 12 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T73 BP 19 EP 24 DI 10.1088/0031-8949/1997/T73/001 PG 6 WC Physics, Multidisciplinary SC Physics GA YC884 UT WOS:A1997YC88400002 ER PT J AU Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Deslattes, RD AF Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Deslattes, RD TI Progress towards absolute X-ray spectroscopy on the NIST electron-beam ion trap: Current status and results SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 8th International Conference on the Physics of Highly Charged Ions (HCI-96) CY SEP 23-26, 1996 CL OMIYA, JAPAN AB Recent observation of Hydrogen-like ions of Vanadium at the NIST Electron-Beam Ion Trap and measurements of Helium-like resonance line are presented. One particular feature of the current series of experiments is the possibility of absolute calibration in a near Doppler-free environment. The current approach to the possible measurement of QED effects in such a system is reviewed There is great potential for precision measurements in the near future. C1 NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899. RP Chantler, CT (reprint author), UNIV MELBOURNE,SCH PHYS,PARKVILLE,VIC 3052,AUSTRALIA. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 8 TC 10 Z9 10 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T73 BP 87 EP 89 DI 10.1088/0031-8949/1997/T73/025 PG 3 WC Physics, Multidisciplinary SC Physics GA YC884 UT WOS:A1997YC88400026 ER PT J AU Gillaspy, JD AF Gillaspy, JD TI First results from the EBIT at NIST SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 6th International Symposium on Electron Beam Ion Sources and Their Applications CY JUN 20-23, 1994 CL STOCKHOLM UNIV, MANNE SIEGBAHN LAB, STOCKHOLM, SWEDEN SP Marcus Wallenberg Fdn Int Cooperat Sci, Stockholm Univ, Manne Siegbahn Lab HO STOCKHOLM UNIV, MANNE SIEGBAHN LAB ID BEAM ION-TRAP; SPECTROSCOPY; ENERGY AB The Electron Beam Ion Trap (EBIT) facility at the National Institute of Standards and Technology (NIST) is now operational and producing atomic physics data. This report gives an overview of the design, operation, and performance of our EBIT. A preview of some of the first atomic physics results is given to illustrate the capabilities of the facility. RP Gillaspy, JD (reprint author), NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899, USA. NR 19 TC 43 Z9 43 U1 0 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T71 BP 99 EP 103 DI 10.1088/0031-8949/1997/T71/017 PG 5 WC Physics, Multidisciplinary SC Physics GA XL908 UT WOS:A1997XL90800018 ER PT J AU Paterson, D Chantler, CT Tran, CQ Hudson, LT Serpa, FG Deslattes, RD AF Paterson, D Chantler, CT Tran, CQ Hudson, LT Serpa, FG Deslattes, RD TI Absolute calibration of an X-ray spectrometer on the NIST Electron-Beam Ion Trap: Control, design and systematics SO PHYSICA SCRIPTA LA English DT Article ID BRAGG GEOMETRY; BENT CRYSTALS; DIFFRACTION AB The course of Electron-Beam Ion Trap (EBIT) experiments depends more and more on precision measurement. To design and test a system of absolute spectroscopy to 10-20 parts per million for such a source is a challenging task. Other design criteria include good efficiency in the 3-10keV energy range, ability to focus a line source and high vacuum compatibility. Some difficulties are discussed. The use of a non-scanning Johann focusing spectrometer and its consequent calibration is discussed The spectrometer has been used in a series of experiments on the NIST EBIT. The detector location is shown (both experimentally and by modelling) to provide a major systematic contribution, which can however be controlled to a suitable tolerance. Future directions are indicated. C1 NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899. RP Paterson, D (reprint author), UNIV MELBOURNE,SCH PHYS,PARKVILLE,VIC 3052,AUSTRALIA. RI Chantler, Christopher/D-4744-2013; Tran, Chanh/M-7868-2015 OI Chantler, Christopher/0000-0001-6608-0048; NR 14 TC 10 Z9 10 U1 0 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T73 BP 400 EP 402 DI 10.1088/0031-8949/1997/T73/133 PG 3 WC Physics, Multidisciplinary SC Physics GA YC884 UT WOS:A1997YC88400134 ER PT J AU Kotochigova, S Levine, ZH Shirley, EL Stiles, MD Clark, CW AF Kotochigova, S Levine, ZH Shirley, EL Stiles, MD Clark, CW TI Local-density-functional calculations of the energy of atoms SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-GAS; FORMALISM; PSEUDOPOTENTIALS; ACCURATE; SYSTEMS; METALS; IONS AB The total energies of atoms and with atomic number Z from 1 to 92 and singly charged cations with Z from 2 to 92 have been calculated to an accuracy of 1 mu hartree within four variants of the Kohn-Sham local-density approximation (LDA). The approximations considered are the local-density approximation, the local-spin-density approximation, the relativistic local-density approximation, and the scalar-relativistic local-density approximation. The total energies for the LDA are found to be in 0.1% agreement with a large atomic number expansion from many-body theory for Z greater than or equal to 40. A comparison to experiment is made for the ionization energies and spin-orbit splittings; also the total energies and eigenvalues of the various theories are compared among themselves. RP Kotochigova, S (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI Clark, Charles/A-8594-2009; Stiles, Mark/K-2426-2012 OI Clark, Charles/0000-0001-8724-9885; Stiles, Mark/0000-0001-8238-4156 NR 41 TC 60 Z9 61 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 1997 VL 55 IS 1 BP 191 EP 199 DI 10.1103/PhysRevA.55.191 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WB980 UT WOS:A1997WB98000024 ER PT J AU Douglas, J Guttman, CM Mah, A Ishinabe, T AF Douglas, J Guttman, CM Mah, A Ishinabe, T TI Spectrum of self-avoiding walk exponents SO PHYSICAL REVIEW E LA English DT Review ID TO-END DISTANCE; 3D ISING-MODEL; BRANCHED POLYMERS; 2 DIMENSIONS; THETA-POINT; EXACT ENUMERATION; EXCLUDED-VOLUME; LATTICE ANIMALS; RANDOM SURFACES; MONTE-CARLO AB A short range interaction is incorporated into the self-avoiding walk (SAW) model of polymer chains by partitioning SAW's into equivalence classes of chain configurations having m nearest-neighbor contacts, and performing an energetically weighted averaging over these restricted SAW configurations. Surprisingly, there have been limited studies of the geometrical properties of ''contact-constrained'' SAW configurations, which contrasts with the well studied unrestricted SAW's. Accordingly, we generate Monte Carlo data for the total number of SAW configurations C-n,C-m having a fixed number of contacts m for chains of length n on square and cubic lattices. Applications of the standard ratio method to the C-n,C-m data shows a unique connectivity constant mu (NAW), corresponding to neighbor-avoiding walks (m = 0), and a ''spectrum'' of gamma exponents which depend on the contact number m. The asymptotic scaling of the number of contact-constrained SAW's is found to be similar to the number of lattice animals and random plaquette surfaces having a fixed cyclomatic index c and genus g, respectively. The existence of this common structure is promising for the development of an analytic theory of interacting polymers and surfaces. C1 YAMAGATA UNIV, FAC ENGN, YONEZAWA, YAMAGATA 992, JAPAN. RP NIST, GAITHERSBURG, MD 20899 USA. NR 107 TC 15 Z9 15 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JAN PY 1997 VL 55 IS 1 BP 738 EP 749 DI 10.1103/PhysRevE.55.738 PN B PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WD546 UT WOS:A1997WD54600021 ER PT J AU Andersen, N Bartschat, K Broad, JT Hertel, IV AF Andersen, N Bartschat, K Broad, JT Hertel, IV TI Collisional alignment and orientation of atomic outer shells .3. Spin-resolved excitation SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE alignment; orientation; collisions; electrons; polarization; excitation ID ELECTRON-IMPACT EXCITATION; DISTORTED-WAVE CALCULATION; DIFFERENTIAL CROSS-SECTIONS; LOW-ENERGY SCATTERING; PHOTON COINCIDENCE EXPERIMENT; ANGULAR-MOMENTUM ORIENTATION; CLOSE-COUPLING CALCULATIONS; CHARGE-CLOUD DISTRIBUTION; EXCITED CHROMIUM ATOMS; CHANNEL OPTICAL METHOD AB The review generalizes the formalism of the first part of this series [N. Andersen, J.W. Gallagher and I.V. Hertel, Phys. Rep. 165 (1988) 1-188] on electron-atom collisions to cases where the spin polarization of the electron is investigated at least once, i.e., before and/or after the collision. In addition, the target atom may be spin polarized. The preparation of initially polarized beams and/or the analysis of photon and spin polarization in the final state significantly increase the number of cases where a ''perfect scattering experiment'' can be performed. The connection between the scattering amplitudes and the generalized Stokes and STU parameters is analyzed. Favorable scattering geometries for perfect experiments and possibilities for consistency checks are pointed out. Recommendations are made about directions of future work. C1 NIST,BOULDER,CO 80309. RP Andersen, N (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Bartschat, Klaus/I-2527-2012 NR 120 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD JAN PY 1997 VL 279 IS 6 BP 252 EP 396 PG 145 WC Physics, Multidisciplinary SC Physics GA WH603 UT WOS:A1997WH60300001 ER PT J AU Andersen, N Broad, JT Campbell, EEB Gallagher, JW Hertel, IV AF Andersen, N Broad, JT Campbell, EEB Gallagher, JW Hertel, IV TI Collisional alignment and orientation of atomic outer shells .2. Quasi-molecular excitation, and beyond SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE alignment; orientation; collisions; electrons; polarization; excitation ID CHARGE-EXCHANGE EXCITATION; TRANSFER CROSS-SECTIONS; ONE-ELECTRON SYSTEMS; LASER-EXCITED ATOMS; COUPLED-STATE CALCULATIONS; SPIN-CHANGING COLLISIONS; H+-NA COLLISIONS; L-ALPHA-EMISSION; + HE COLLISIONS; VECTOR POLARIZATION ANALYSIS AB We present a comprehensive and critical review on atomic alignment and orientation after collisional excitation including a full reevaluation and discussion of data published to date in the literature. The present Vol. II focuses on the quasimolecular low-energy regime in ion-atom and atom-atom processes. The discussion centers on experimental and theoretical data for planar scattering geometry in which the alignment and orientation parameters are determined as a function of scattering angle (particle-photon coincidence or scattering from laser-excited atoms, the so-called third-generation of experiments). In addition, alignment studies with cylindrical symmetry (second-generation experiments) and integral cross sections (first-generation experiments) are also discussed wherever this clarifies the understanding of the relevant processes. A unified set of parameters is used with reference to the so-called natural coordinate frame (having its z-axis perpendicular to the collision plane): the angular momentum transfer L perpendicular to, the alignment angle gamma, the linear polarization P+ and the symmetry-changing probability rho(00). This parametrization allows one an intuitive interpretation of these otherwise somewhat abstract quantities. After reviewing the theoretical framework the individual model systems are described, starting with excitation and charge transfer in the genuine one-electron system H++H and ending with He++Rg (Rg = raregas atom) collisions involving many electrons and demonstrating the explicit influence of spin-orbit coupling. In several appendices a compilation of the relevant classical deflection functions and many useful formulae for the interpretation of alignment and orientation parameters are reported. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. NIELS BOHR INST, ORSTED LAB, DK-2100 COPENHAGEN, DENMARK. MAX BORN INST NICHTLINEARE OPT & KURZZEITSPEKTROS, D-12474 BERLIN, GERMANY. NIST, GAITHERSBURG, MD 20899 USA. FREE UNIV BERLIN, FACHBEREICH PHYS, D-14195 BERLIN, GERMANY. RP Andersen, N (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RI Campbell, Eleanor/D-6488-2011 OI Campbell, Eleanor/0000-0002-4656-3218 NR 281 TC 33 Z9 33 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD JAN PY 1997 VL 278 IS 3-4 BP 107 EP 289 DI 10.1016/S0370-1573(96)00026-9 PG 183 WC Physics, Multidisciplinary SC Physics GA WD186 UT WOS:A1997WD18600001 ER PT B AU Cypher, D Wakid, S AF Cypher, D Wakid, S GP IEEE TI Error characteristics of CDMA and impact on voice, e-mail, and web pages SO PIMRC '97 - EIGHTH IEEE INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS: WAVES OF THE YEAR 2000+, TECHNICAL PROGRAM, PROCEEDINGS, VOLS 1-3 LA English DT Proceedings Paper CT 8th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications - Waves of the Year 2000+ (PIMRC 97) CY SEP 01-04, 1997 CL HELSINKI, FINLAND SP IEEE Commun Soc, IEEE Commun Chapter Finland, IEEE Finland Sect, IEE, IEICE AB A Code Division Multiple Access (CDMA) wireless network is simulated to analyze errors, determine impact on services, and provide an upper bound on the number of active channels. The simulation emphasizes the encoder, decoder/correlator, and a threshold detector; bur assumes a resultant Gaussian function for the ''air interface'' noise. Since the characteristics of a wireless environment vary significantly, we examine, as a whole, the errors on the received signal without accounting for specific error contributions from power, fading, propagation, interference from other users, and other factors in such environment. The CDMA encoder uses the 64 Walsh codes that are specified in the draft Wideband CDMA Air Interface Compatibility Standard for 1.85 to 1.99 GHz PCS Applications [I]. We use a digitized actual speech database to test for the intelligibility of the voice service over such a CDMA air interface. Therefore, we are able to learn about the nature of the errors inherent in such a frequency spreading technique and also determine an upper bound apt the simultaneous active channels that would preserve the quality of service (QOS). RP Cypher, D (reprint author), NATL INST STAND & TECHNOL,INFORMAT TECHNOL LAB,BOULDER,CO, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3871-5 PY 1997 BP 719 EP 723 PG 5 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BJ70N UT WOS:A1997BJ70N00145 ER PT B AU Christopher, N AF Christopher, N BE Goldstein, BLM TI NAMT framework for discrete parts manufacturing: Experience report SO PLUG AND PLAY SOFTWARE FOR AGILE MANUFACTURING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Plug and Play Software for Agile Manufacturing CY NOV 18-19, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers DE manufacturing; standards; information technology; validation testing; information models; interface definitions; SDAI; CORBA; STEP; NAMT; machine control; factory control; systems integration AB Industry need for standards to support integration of distributed manufacturing information technology systems is driving a process for creating validated pre-standard specifications. These specifications are likely to be the basis for manufacturing information technology standards in the future. The Framework for Discrete Parts Manufacturing project has implemented a distributed manufacturing software system as a basis for validation testing and analysis of emerging manufacturing information technologies. This paper describes a testbed project for validation of pre-standard specifications for integration of distributed manufacturing information technology systems. This project begins with a scenario for manufacturing operations and deploys several related specifications against this scenario. This deployment provides the opportunity for analysis and local validation of the specifications. It also provides the opportunity to explore the relationship among several specifications that could be the basis for standards in the future. This paper discusses the preliminary implementation of the specifications under analysis and projects future work involved in validation testing of industry consortia developed manufacturing information technology specifications. RP Christopher, N (reprint author), NIST,MANUFACTURING ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2315-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 2913 BP 117 EP 131 DI 10.1117/12.263461 PG 3 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Manufacturing SC Computer Science; Engineering GA BH07H UT WOS:A1997BH07H00006 ER PT B AU Germer, TA Asmail, CC AF Germer, TA Asmail, CC BE Goldstein, DH Chipman, RA TI Bidirectional ellipsometry and its application to the characterization of surfaces SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing CY JUL 30-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE polarimetry; scatter; surfaces; microroughness; subsurface defects AB The polarization of light scattered out of the plane of incidence was measured from rough and microrough silicon, polished fused silica and glass ceramic, and ground and polished black glass. The measurement results are in excellent agreement with models for scattering from microroughness or subsurface defects, demonstrating that the polarization of scattered light can be used to distinguish between microroughness and subsurface defects. RP Germer, TA (reprint author), NIST,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 7 Z9 8 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2543-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3121 BP 173 EP 182 DI 10.1117/12.278968 PG 10 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78K UT WOS:A1997BJ78K00020 ER PT B AU Rochford, KB Rose, AH AF Rochford, KB Rose, AH BE Goldstein, DH Chipman, RA TI Standards for linear retardance SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing CY JUL 30-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE linear retardance; metrology; polarization; retardance; standards AB NIST has developed a Standard Reference Material that can be used to calibrate polarimetric instruments and improve measurement accuracy. The device, based on concatenated Fresnel rhombs, provides nominally 90 degrees retardance at 1319 nm, with the actual value known within +/-0.1 degrees. The design of the retarder is reviewed, and the stability of retardance over time is discussed. A procedure for certification is outlined. RP Rochford, KB (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECT,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2543-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3121 BP 188 EP 192 DI 10.1117/12.278970 PG 5 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78K UT WOS:A1997BJ78K00022 ER PT J AU Wise, SA Schantz, MM Hays, MJ Koster, BJ Sharpless, KE Sander, LC Schiller, SB AF Wise, SA Schantz, MM Hays, MJ Koster, BJ Sharpless, KE Sander, LC Schiller, SB TI Certification of polycyclic aromatic hydrocarbons in a Mussel Tissue Standard Reference Material (SRM) SO POLYCYCLIC AROMATIC COMPOUNDS LA English DT Article DE gas chromatography mass spectrometry (GC/MS); mussel tissue; polycyclic aromatic hydrocarbons (PAHs); reversed-phase liquid chromatography; standard reference materials (SRMs) ID TRACE ORGANIC-CONSTITUENTS; MARINE SEDIMENT; LIQUID; CHROMATOGRAPHY AB Standard Reference Material(SRM) 1974a, Organics in Mussel Tissue (Mytilus edulis), has been issued with certified and noncertified concentrations for 33 polycyclic aromatic hydrocarbons (PAHs). The mussel tissue material was analyzed using four different analytical techniques based on gas chromatography/mass spectrometry (GCMS) on different stationary phases and on reversed-phase liquid chromatography with fluorescence detection. The results from the different analytical techniques were combined to provide certified concentrations for 15 PAHs with relative uncertainties typically between 4% and 11%. C1 NATL INST STAND & TECHNOL,STAT ENGN DIV,GAITHERSBURG,MD 20899. RP Wise, SA (reprint author), NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 14 TC 11 Z9 11 U1 1 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1040-6638 J9 POLYCYCL AROMAT COMP JI Polycycl. Aromat. Compd. PY 1997 VL 12 IS 1 BP 21 EP 36 DI 10.1080/10406639708233825 PG 16 WC Chemistry, Organic SC Chemistry GA XB997 UT WOS:A1997XB99700002 ER PT S AU Butler, KM AF Butler, KM BE Khemani, KC TI Physical modeling of intumescent fire retardant polymers SO POLYMERIC FOAMS: SCIENCE AND TECHNOLOGY SE ACS Symposium Series LA English DT Review CT International Symposium on Recent Advances in Polymeric Foam Science and Technology, at the 212th National Meeting of the American-Chemical-Society CY AUG 25-29, 1996 CL ORLANDO, FL SP Amer Chem Soc, Div Polym Chem ID BUBBLE-GROWTH; THERMAL-CONDUCTIVITY; FOAM GROWTH; SYSTEMS; DEGRADATION; MECHANISM; DYNAMICS; MIXTURES; LIQUID AB Intumescent chemical systems are designed to swell into a thick, robust foam upon exposure to heat, protecting the underlying material from fire by providing a physical barrier to heat and mass transfer. The mechanisms determining the fire-resistant properties of these materials are not well understood. Various approaches to modeling intumescent behavior are reviewed. A three-dimensional model that incorporates physical and chemical phenomena at the scale of a single bubble is described. RP Butler, KM (reprint author), NIST, BLDG & FIRE RES LAB, MAIL STOP B258, GAITHERSBURG, MD 20899 USA. NR 51 TC 12 Z9 12 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3516-3 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 669 BP 214 EP 230 PG 17 WC Chemistry, Multidisciplinary; Polymer Science SC Chemistry; Polymer Science GA BJ07A UT WOS:A1997BJ07A00015 ER PT J AU Estler, WT AF Estler, WT TI A straight edge SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Editorial Material RP Estler, WT (reprint author), NIST,GAITHERSBURG,MD 20899, USA. 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 SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD JAN PY 1997 VL 20 IS 1 BP 66 EP 66 PG 1 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA XC223 UT WOS:A1997XC22300009 ER PT B AU Vorburger, TV Dixson, RG Tsai, V Doi, T Song, JF Renegar, TB Fu, J AF Vorburger, TV Dixson, RG Tsai, V Doi, T Song, JF Renegar, TB Fu, J GP AMER SOC PRECIS ENGN TI Calibration problems in surface metrology SO PROCEEDINGS OF: ADVANCES IN SURFACE METROLOGY LA English DT Meeting Abstract CT ASPE 1997 Spring Topical Meeting on Advances in Surface Metrology CY JUN 02-05, 1997 CL ST JOHNS COLL, ANNAPOLIS, MD SP Amer Soc Prec Engn HO ST JOHNS COLL C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Vorburger, TV (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-17-8 PY 1997 BP 69 EP 69 PG 1 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BK95K UT WOS:000073939400014 ER PT B AU Dixson, R Tsai, VW Vorburger, T Williams, ED Wang, XS Fu, J Koning, R AF Dixson, R Tsai, VW Vorburger, T Williams, ED Wang, XS Fu, J Koning, R GP AMER SOC PRECIS ENGN TI Measurements of pitch, height, and width artifacts with the NIST calibrated atomic force microscope SO PROCEEDINGS OF: ADVANCES IN SURFACE METROLOGY LA English DT Proceedings Paper CT ASPE 1997 Spring Topical Meeting on Advances in Surface Metrology CY JUN 02-05, 1997 CL ST JOHNS COLL, ANNAPOLIS, MD SP Amer Soc Prec Engn HO ST JOHNS COLL C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Dixson, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-17-8 PY 1997 BP 70 EP 75 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BK95K UT WOS:000073939400015 ER PT B AU Schere, K AF Schere, K BE Borrell, PM Borrell, P Kelly, K Cvitas, T Seiler, W TI The interface of atmospheric sciences and air quality management: A US perspective SO PROCEEDINGS OF EUROTRAC SYMPOSIUM '96 - TRANSPORT AND TRANSFORMATION OF POLLUTANTS IN THE TROPOSPHERE, VOL 1: CLOUDS, AEROSOLS, MODELLING AND PHOTO-OXIDANTS LA English DT Proceedings Paper CT EUROTRAC Symposium 96 - Transport and Transformation of Pollutants in the Troposphere CY MAR 25-29, 1996 CL GARMISCH PARTENKI, GERMANY SP BMW AG, European Commiss, Ford Res Labs, Marktgemeinde, Garmisch Partenkirchen, Mercedes Benz RP Schere, K (reprint author), NOAA,ATMOSPHER SCI MODELLING DIV,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON, HANTS, ENGLAND S04 2AA BN 1-85312-496-6 PY 1997 BP 1031 EP 1042 PG 12 WC Chemistry, Analytical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Chemistry; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BH53U UT WOS:A1997BH53U00184 ER PT B AU Oates, CW Stephens, M Hollberg, L AF Oates, CW Stephens, M Hollberg, L GP IEEE TI An all-diode-laser optical frequency reference using laser-trapped calcium SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB The 657 nn calcium intercombination line is an attractive optical frequency/length reference due to its high line Q (10(12)) and insensitivity to external perturbations. In this paper we describe progress towards an all-diode-laser-based reference using laser-trapped Ca. To generate 35 mW of 423 nm trap light, we double the frequency of a 150 mW, 846 nm diode laser with a nonlinear crystal (KNbO3) inside a resonant build-up cavity. We use this light to trap 2x10(7) atoms in a compact, magneto-optic trap. Spectroscopy of the narrow 657 nm transition is performed with a frequency-stabilized diode laser system. With the trapped atoms we have measured optical Ramsey fringes with a linewidth of 6 kHz. We discuss future improvements as well as potential performance which could achieve a fractional frequency instability of <3x10(-15). RP Oates, CW (reprint author), NIST,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 6 Z9 6 U1 1 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 219 EP 224 DI 10.1109/FREQ.1997.638547 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00032 ER PT B AU Lee, WD Shirley, JH Drullinger, RE AF Lee, WD Shirley, JH Drullinger, RE GP IEEE TI Analysis of frequency biases and noise in sampled digital frequency servos for primary frequency standards SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB Unlike previous frequency standards at NIST, the main frequency servo of NIST-7, the U.S. primary frequency standard, does not lock al local oscillator to the atomic resonance. Instead it compares the frequencies of the atomic resonance and a reference oscillator. This paper presents an analysis of biases and noise in this digital servo. We show that a slight modification of the servo permits sensitive measurements Ibr the presence of frequency biases. RP Lee, WD (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 249 EP 252 DI 10.1109/FREQ.1997.638554 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00038 ER PT B AU Parker, TE Gray, JE Peppler, TK AF Parker, TE Gray, JE Peppler, TK GP IEEE TI Environmental sensitivities of cavity tuned hydrogen masers SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US DE environmental sensitivities; hydrogen maser; cavity tuned AB With the increasing number of cavity-tuned hydrogen masers in use around the world in time scales and as reference oscillators for primary frequency standards, it is necessary to have a complete understanding of the environmental sensitivities of the masers. Common-mode frequency fluctuations are of great concern and the degradation of maser frequency stability due to environmental fluctuations should be minimized. Measurements of environmental sensitivities (temperature, relative humidity, atmospheric pressure, line voltage and magnetic field) have demonstrated that the frequency stability of cavity-tuned hydrogen masers is not significantly degraded if the masers are contained in a reasonably controlled environment. RP Parker, TE (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 273 EP 279 DI 10.1109/FREQ.1997.638559 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00043 ER PT B AU Weiss, M Zhang, V Nelson, L Hanns, V Regalado, MGL AF Weiss, M Zhang, V Nelson, L Hanns, V Regalado, MGL GP IEEE TI Delay variations in some GPS timing receivers SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB We report a number of studies of variations in the delay through GPS receivers used for timing at NIST. As a first study, the data from the receivers built at NIST In the early 1980's (called the NBS-type receiver) are compared over periods of many years to show variations in delay. These receivers vary of the order of 5 ns over a year, with the peak-to-peak variation of 10 ns over 6 years. A second study shows the temperature dependence of the antenna system and of the receiver unit of the NBS-type receiver. The antenna system of one receiver was held constant at 42 degrees C for the entire experiment. The antenna of another system was held at various fixed temperatures, and the relative delay through the two antennas was determined at each temperature. Similarly we varied the receiver temperature of one system, holding the antenna temperature constant. Though the delay varied 2 ns over the course of the experiment, this variation was not correlated with temperature. We next report the delay variation with temperature of a commercial multi-channel GPS receiver, which we are investigating for use in an alternative common-view receiver. We studied the temperature dependance of two receivers separate from the antenna. In one unit, we found a 2.3 ns a peak-to-peak variation of delay with temperature and se 4.3 ns peak-to-peak variation in the other, both over a range from 10 degrees C to 55 degrees C. The delay variation in both appears to be approximately quadratic over some range of temperature. RP Weiss, M (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 0 TC 3 Z9 10 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 304 EP 312 DI 10.1109/FREQ.1997.638563 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00047 ER PT B AU FerrePikal, ES Vig, JR Camparo, JC Cutler, LS Maleki, L Riley, WJ Stein, SR Thomas, CE Walls, FL White, JD AF FerrePikal, ES Vig, JR Camparo, JC Cutler, LS Maleki, L Riley, WJ Stein, SR Thomas, CE Walls, FL White, JD GP IEEE TI Draft revision of IEEE STD 1139-1988 Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology - Random instabilities SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB This is a draft revision of IEEE Std 1139-1988 Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology. This draft standard covers the fundamental metrology for describing random instabilities of importance to frequency and time metrology. Quantities covered include frequency, amplitude, and phase instabilities; spectral densities of frequency, amplitude, and phase fluctuations; variances of frequency and phase fluctuations; time prediction, and confidence limits when estimating the variance from a finite data set. The standard unit of measure for characterizing phase and frequency instabilities in the frequency domain is L(F), defined as one half of the double-sideband spectral density of phase fluctuations. In the time domain, the standard unit of measure of frequency and phase instabilities is the fully overlapped Allan deviation sigma(y)(tau) or the fully overlapped modified Allan deviation Mod sigma y(tau). RP FerrePikal, ES (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 22 Z9 22 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 338 EP 357 DI 10.1109/FREQ.1997.638567 PG 20 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00051 ER PT B AU Aramburo, MCD FerrePikal, ES Walls, FI Ascarrunz, HD AF Aramburo, MCD FerrePikal, ES Walls, FI Ascarrunz, HD GP IEEE TI Comparison of 1/f noise in commercial amplifiers SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB In this paper we compare the 1/f phase modulation (PM) noise of two different families of commercial amplifiers under different operating conditions. The first family used GaAs heterojunction bipolar transistors (HBT) while the second used Si bipolar junction transistors (BJT) in a Darlington pair amplifier configuration. Three currents for the HBT family and four currents Ear the BST family were chosen for study. The PM noise of tile amplifiers was measured at carrier frequencies of 5, 10, and 100 MHz. In general, the HBT-based amplifiers had somewhat lower PM noise than the BJT based amplifiers, Amplifiers operating with higher current generally had lower PM noise than those operating with lower current. A commercial feed-forward amplifier had much lower 1/f PM noise than all the other commercial amplifiers tested. RP Aramburo, MCD (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 470 EP 477 DI 10.1109/FREQ.1997.638645 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00069 ER PT B AU FerrePikal, ES Walls, FL AF FerrePikal, ES Walls, FL GP IEEE TI Low PM noise regenerative dividers SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB This paper describes the various contributions to the PM noise added by an oscillating regenerative divide-by-two circuit (halver). Two circuits are investigated: a 100 MHz to 50 MHz divider and a 18.4 GHz to 9.2 GHz divider, Several configurations of the 100 MHz to 50 MHz divider were studied. It was found that the broadband noise floor is determined by the thermal noise of the amplifier, We found that the thermal noise of the amplifier at the image frequency (3/2) v(o), unless eliminated, contributes to the thermal noise of the divider and thus increases the broadband noise by 3 dB, A PM noise performance of L(f) = 10(-14.4)/f + 10(-17.9) was ultimately achieved using a medium drive power mixer, PM noise measurements of the 18.4 GHz to 9.2 GHz divider show that the broadband noise is L(10 MHz) = -168 dB below the carrier in a 1 Hz bandwidth (dBc/Hz), probably limited by the measurement system noise. A close-in noise of L(10 Hz) = -136 dBc/Hz and L(10 kHz)= -157 dBc/Hz was achieved, This design could easily be extended to 40 GHz and beyond, limited only by the availability of the mixer. RP FerrePikal, ES (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 478 EP 484 DI 10.1109/FREQ.1997.638646 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00070 ER PT B AU Walls, FL AF Walls, FL GP IEEE TI Suppressed carrier based PM and AM noise measurement techniques SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB The purpose of this paper is to discuss the advantages and disadvantages of using carrier suppression techniques to measure PM and AM noise in oscillators, amplifiers, and components. Carrier suppression was first introduced by Klaus H. Sann in 1968 to measure noise in amplifiers. The major advantages of these configurations over conventional measurements is that the noise contribution of the phase or amplitude detector is reduced by the degree of carrier suppression until the thermal noise limit is reached. This typically results in an improvement of 10-60 dB in the noise floor. The advantages over the three-cornered-hat cross-correlation technique is that the same or better results can be obtained in real time instead of having to wait for a large number of averages. The disadvantage is that this approach does not work as well as conventional approaches for measuring AM noise in sources. Three-cornered-hat techniques used with conventional mixer-based system or carrier suppressed systems are required to obtain an unbiased estimate of the PM noise in state-of-the-art sources. Suppressed carrier techniques can also be used to reduce the contribution of the phase detector in some specialized oscillator configurations. RP Walls, FL (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO, USA. NR 0 TC 16 Z9 18 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 485 EP 492 DI 10.1109/FREQ.1997.638647 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00071 ER PT B AU Jones, A Iuliano, M AF Jones, A Iuliano, M BE Andradottir, S Healy, KJ Withers, DH Nelson, BL TI A simulation-based production testbed SO PROCEEDINGS OF THE 1997 WINTER SIMULATION CONFERENCE LA English DT Proceedings Paper CT 1997 Winter Simulation Conference (WSC 97) CY DEC 07-10, 1997 CL ATLANTA, GA SP Amer Stat Assoc, Assoc Comp Machinery, Special Interest Grp Simulat, Inst Operat Res & Management Sci, Coll Simulat, IEEE Comp Soc, IEEE Syst Man & Cybernet Soc, Inst Ind Engineers, NIST, Soc Comp Simulat Int AB Researchers at the National Institute of Standards and Technology have been developing a simulation-based production testbed. This testbed contains continuous simulation models of production equipment and processes, and discrete-event simulation models of various production systems. In addition, it contains both commercial and prototype software applications that implement a number of production functions from order release to final inspection. This testbed provides an environment for the development and testing of interfaces which can provide an integrating infrastructure for these applications. These interfaces will be based on information models and exchange protocols, and will specify what information is shared across those applications and how it is exchanged. This paper describes the current state of the testbed, and the projects currently being conducted in the testbed. C1 NIST, Gaithersburg, MD 20899 USA. RP Jones, A (reprint author), NIST, Bldg 220 Room A127, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4278-X PY 1997 BP 1299 EP 1306 DI 10.1145/268437.268775 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Operations Research & Management Science; Mathematics GA BK18F UT WOS:000071432100186 ER PT B AU Cookson, AH AF Cookson, AH GP IEEE TI Role of electrical insulation in the design and operation of high voltage equipment SO PROCEEDINGS OF THE 5TH INTERNATIONAL CONFERENCE ON PROPERTIES AND APPLICATIONS OF DIELECTRIC MATERIALS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th International Conference on Properties and Applications of Dielectric Materials CY MAY 25-30, 1997 CL SEOUL, SOUTH KOREA SP IEEE Dielect & Elect Insulat Soc, Korean Inst Elect & Electr Mat Engineers AB Electrical insulation is key for all high-voltage equipment. The insulation design factors are summarized for major high-voltage equipment for generation and transmission systems, including generators, capacitors, transformers, underground transmission cables, and gas-insulated equipment. Recent developments of new insulation systems have resulted in significantly improved systems, including enhanced performance, improved manufacturability, reduced size and cost, and extended operational life. The impact of these developments and the future directions of new insulation systems are discussed for each system. It is emphasized that to appreciate the full technical and economic impact of changing the insulation, one needs to consider not just the component, but the complete, installed and operational system. RP Cookson, AH (reprint author), NIST,ELECT & ELECT ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-2652-0 PY 1997 BP 1 EP 5 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BJ48U UT WOS:A1997BJ48U00001 ER PT B AU Kopanski, JJ Marchiando, JF Alvis, R AF Kopanski, JJ Marchiando, JF Alvis, R BE RaiChoudhury, P Benton, JL Schroder, DK Shaffner, TJ TI Practical metrology aspects of scanning capacitance microscopy for silicon 2-D dopant profiling SO PROCEEDINGS OF THE ELECTROCHEMICAL SOCIETY SYMPOSIUM ON DIAGNOSTIC TECHNIQUES FOR SEMICONDUCTOR MATERIALS AND DEVICES SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Diagnostic Techniques for Semiconductor Materials and Devices Symposium at the Electrochemical-Society Meeting CY MAY 06-08, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Electr Div, Soc Photo Opt Instrumentat Engineers AB When operated under controlled conditions, the scanning capacitance microscope (SCM) can function as a practical and quantitative two-dimensional dopant profiling toot for silicon, An investigation of the SCM operating procedures and conditions necessary to produce SCM images that are readily amenable to quantitative interpretation is discussed. The data interpretation formalism and models used to rapidly convert SCM images to dopant profiles are described. SCM images of cross-sectioned p-n junctions are compared to model predictions. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Kopanski, JJ (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-139-0 J9 ELEC SOC S PY 1997 VL 97 IS 12 BP 102 EP 113 PG 12 WC Electrochemistry; Optics SC Electrochemistry; Optics GA BK24Z UT WOS:000071609700010 ER PT B AU Libes, D AF Libes, D GP USENIX ASSOC TI Writing a Tcl extension in only 7 years SO PROCEEDINGS OF THE FIFTH ANNUAL TCL/TK WORKSHOP LA English DT Proceedings Paper CT 5th Annual Tcl/Tk Workshop CY JUL 14-17, 1997 CL BOSTON, MA SP USENIX Assoc DE expect; lessons learned; software archaeology; Tcl AB Expect is a tool for automating interactive applications. Expect was constructed using Tcl, a language library designed to be embedded into applications. This paper describes experiences with Expect and Tcl over a seven year period. These experiences may help other extension designers as well as the Tcl developers or developers of any other extension language see some of the challenges that a single extension had to deal with while evolving at the same time as Tcl. Tcl and Expect users may also use these 'war stories' to gain insight into why Expect works and looks the way it does today. RP Libes, D (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 BN 1-880446-87-1 PY 1997 BP 55 EP 65 PG 11 WC Computer Science, Software Engineering SC Computer Science GA BJ34F UT WOS:A1997BJ34F00008 ER PT B AU Libes, D AF Libes, D GP USENIX ASSOC TI Managing Tcl's namespaces collaboratively SO PROCEEDINGS OF THE FIFTH ANNUAL TCL/TK WORKSHOP LA English DT Proceedings Paper CT 5th Annual Tcl/Tk Workshop CY JUL 14-17, 1997 CL BOSTON, MA SP USENIX Assoc DE collaborative namespace management; data element registry; NICS; Tcl AB The NIST Identifier Collaboration Service (NICS) is a proposed service to encourage collaboration among researchers and developers when choosing identifiers, far in advance of when it might ordinarily occur. This would support and enhance standards development activities, and development and communications in a variety of fields from software development to system administration. Implementation of this system would provide immediate and significant time and cost-savings to many technology administrators, researchers, developers, and implementers world-wide. This paper describes the benefits of NICS to the Tcl community. This paper also briefly describes the implementation of NICS which is Tcl-based internally. RP Libes, D (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 BN 1-880446-87-1 PY 1997 BP 115 EP 123 PG 9 WC Computer Science, Software Engineering SC Computer Science GA BJ34F UT WOS:A1997BJ34F00015 ER PT B AU Barnea, N Farr, JK Henry, CB AF Barnea, N Farr, JK Henry, CB GP EC EC TI The Ilwaco tire fire and spill: Chemistry and health and safety aspects SO PROCEEDINGS OF THE FOURTEENTH TECHNICAL SEMINAR ON CHEMICAL SPILLS LA English DT Proceedings Paper CT 14th Technical Seminar on Chemical Spills CY JUN 09-10, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB In the fall of 1995, shredded tire chips were used as road fill to repair landslide damage to State Route 100 Loop, near Ilwaco, Washington. A few weeks later the road cracked, and gases and steam escaped. Tire pyrolysis product began spilling from the bottom of the slope under the road into an adjacent tideflat. The tire chips under the road surface caught fire and began smoldering. This paper will briefly review tire fires in general and the tire fire in Ilwaco in particular. It will discuss the chemistry involved with this tire fire and possible ways in which the fire could have initiated at this site. The paper will describe the chemical processes taking place when solid tire chips become gases and pyrolysis fluid, and present the results of laboratory analysis of the pyrolysis liquid and gases. The paper will review the human health and safety issues present in the initial stages of the response, including air sampling and identification of the gases, and considerations for personnel protection. It will conclude with recommendations for similar future incidents. C1 Natl Ocean & Atmospher Adm, Seattle, WA USA. RP Barnea, N (reprint author), Natl Ocean & Atmospher Adm, Seattle, WA USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 29 EP 40 PG 12 WC Engineering, Environmental; Environmental Sciences; Toxicology SC Engineering; Environmental Sciences & Ecology; Toxicology GA BP61Z UT WOS:000085691100004 ER PT B AU Lee, SE Robinson, GS Casali, JG AF Lee, SE Robinson, GS Casali, JG GP HUMAN FACTORS & ERGONOM SOC TI An investigation of temporary threshold shift and noise dose in contemporary commercial trucks SO PROCEEDINGS OF THE HUMAN FACTORS AND ERGONOMICS SOCIETY 41ST ANNUAL MEETING, 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT 41st Annual Meeting of the Human-Factors-and-Ergonomics-Society CY 1997 CL ALBUQUERQUE, NM SP Human Factors & Ergonom Soc AB The Federal Highway Administration (FHWA) currently requires that individuals seeking a commercial driver's license for interstate commerce possess a certain minimal level of hearing. Past studies have shown that truck noise (in certain older vehicles, at least) is loud enough to cause permanent hearing damage if experienced for sufficient durations. There have also been reports that truck drivers have indeed suffered hearing loss, possibly due to their noise exposure. As part of an overall evaluation of the FHWA hearing requirement, pre- and post-workday audiograms were performed on 10 truck drivers to determine whether they suffer a temporary threshold shift (TTS) at the end of the work shift. Dosimeters were used to measure the noise dose for the same 10 drivers. Ten different trucks were used; although the trucks were from three homogenous manufacturer groups, the truck mileage, cargo, and weight variables demonstrated considerable randomness. The results showed that there was no evidence of a TTS among these 10 drivers and that the noise doses experienced by these drivers were all within a range considered safe by OSHA. However, an analysis of pre-work audiograms for 30 truck drivers showed some evidence of a noise-induced permanent threshold shift, when these drivers' audiograms were compared to those of a similar age/gender non-noise exposed population. RP Lee, SE (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT IND & SYST ENGN,AUDITORY SYST LAB,NIST,NVLAP,BLACKSBURG,VA 24061, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMAN FACTORS AND ERGONOMICS SOC PI SANTA MONICA PA PO BOX 1369, SANTA MONICA, CA 90406-1369 BN 0-945289-07-3 PY 1997 BP 998 EP 1002 PG 5 WC Engineering, Aerospace; Computer Science, Cybernetics; Engineering, Industrial; Ergonomics SC Engineering; Computer Science GA BJ82J UT WOS:A1997BJ82J00219 ER PT B AU Saffle, RE Johnson, LD AF Saffle, RE Johnson, LD GP IEEE TI NEXRAD product improvement overview SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB The National Weather Service, in cooperation with their Next Generation Weather Radar (NEXRAD) partners in the Department of Defense (DoD) and Department of Transportation (DOT), are currently planning and executing a scientific and technical evolution of the Weather Surveillance Radar-1988 Doppler (WSR-88D) system. This effort is the necessary and planned continuing improvement of the WSR-88D system to: 1) meet NOAA's strategic goal of advancing short-term warnings and forecast services for the general public, 2) meet FAA requirements for additional and higher quality products, and 3) meet DoD requirements for a radar user interface interoperable between NEXRAD and other deployable Doppler weather radar systems. C1 NWS,OFF SYST DEV,SILVER SPRING,MD. RP Saffle, RE (reprint author), 1325 EW HIGHWAY,SSMC2,ROOM 12152,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 288 EP 293 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00034 ER PT B AU Elvander, RC Johnson, LD Holt, SM AF Elvander, RC Johnson, LD Holt, SM GP IEEE TI The NEXRAD algorithm survey and analysis for the rehosted radar product generation (RPG) subsystem SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB While the Next Generation Weather Radar (NEXRAD), also known as Weather Surveillance Radar-1988 Doppler (WSR-88D), units have been effective in providing guidance to forecasters for use in warning and forecast operations, forecasters must conduct extensive manual analysis of its products to discern much of the severe weather related information and to separate valid data from contaminants such as range/velocity folding, clutter, and anomalous propagation. Sophisticated algorithms and data quality control techniques to support these tasks in a robust, reliable manner are a vital component of the Weather Forecast Office (WFO) tools required to meet National Weather Service (NWS) Modernization and Associated Restructuring (MAR) staffing goals. The WSR-88D Radar Product Generation (RPG) subsystem requires substantial expansion of capacity to support the level of processing needed by a whole new generation of sophisticated algorithms. C1 SYST ACQUISIT OFF,NEXRAD,SILVER SPRING,MD. RP Elvander, RC (reprint author), 1325 EAST WEST HIGHWAY,SSMC2,ROOM 15130,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 294 EP 301 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00035 ER PT B AU Zahrai, A Jing, ZQ Peery, N AF Zahrai, A Jing, ZQ Peery, N GP IEEE TI A distributed architecture for the WSR-88D (NEXRAD) radar product generator (RPG) SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB In response to increasing user demand for additional capability and improved performance, the National Weather Service (NWS) launched a product improvement project to replace legacy computing platforms in the Next Generation Weather Radar (NEXRAD) radars, also known as the Weather Surveillance Radar-1988 Doppler (WSR-88D), with modern equipment. The first phase of this project targets the Radar Product Generator (RPG). Among many objectives of this project are hardware independence and portability of application software. In addition, long term viability and supportability of the NEXRAD system requires a modular and scalable architecture. To address these critical design requirements a distributed architecture based on open system standards has been adopted. This architecture is based on commercial workstation platforms in a networked environment. This paper presents the open system architecture and design issues associated with the RPG. RP Zahrai, A (reprint author), NOAA,ERL,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 302 EP 307 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00036 ER PT B AU Jain, M Jing, ZQ Zahrai, A Dodson, A Burcham, H Priegnitz, D Smith, S AF Jain, M Jing, ZQ Zahrai, A Dodson, A Burcham, H Priegnitz, D Smith, S GP IEEE TI Software architecture of the NEXRAD open systems radar product generator (ORPG) SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB Establishment of an effective software architecture for the Open System Radar Product Generation (ORPG) subsystem will result in a Next Generation Weather Radar (NEXRAD) system where the software will be portable, scaleable, extensible, and interoperable. Several characteristics of the targeted architecture will contribute to these qualities. The establishment of well encapsulated software layers will promote portability, extensibility, and the ability to effectively upgrade software within the ORPG. The use of software standards will aid in portability and interoperability between like-standard compliant software, be it commercially or custom developed. The resulting ORPG will be composed of a collection of independent functions operating in an interdependent fashion, providing a more robust and scaleable RPG. The ultimate goal of the ORPG software architecture is to encourage and facilitate the insertion of the latest meteorological technology and better support the evolution of the NEXRAD system to effectively satisfy the operational requirements of the field. RP Jain, M (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 308 EP 313 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00037 ER PT B AU Jing, ZQ Smith, S Jain, M Zahrai, A AF Jing, ZQ Smith, S Jain, M Zahrai, A GP IEEE TI Migration of legacy WSR-88D algorithms and product generators to the open system RPG SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB A substantial part of the current Weather Surveillance Radar-1988 Doppler (WSR-88D) Radar Product Genration (RPG) software consists of the product generation and meteorological algorithms, which were implemented through about 50 tasks. These tasks, written in FORTRAN with CONCURRENT extensions and running under the CONCURRENT OS/32 operating system (OS), can not be directly compiled and run under a UNIX OS. Inter-task communication is implemented through using shared memory segments, requiring all tasks to be running on the same computer hardware. Tasks must fit into a predefined data flow network and are controlled by a central control module. This makes the system sensitive to task failure and difficult to be dynamically reconfigured (redistributing the tasks among hosts, adding new tasks and so on). These tasks contain sophisticated algorithms and lengthy code. Rewriting these tasks would require a substantial programming and verification effort and cause maintenance problems in the transition period when both current and the ported versions had to be maintained. On the other hand, these tasks use a similar coding structure and application programming interface (API) and requires minimal system support, which makes direct porting feasible. After some pathfinding work, we decided to take a direct porting approach to migrate these tasks to the Open Sytem RPG(ORPG). The porting approach is unique in that only a single version of the source code is maintained. The ported version uses the original RPG code without any change for all subroutines except the main subroutine, which is replaced by a new version. A preprocessor is developed to convert the CONCURRENT FORTRAN code to a standard FORTRAN code, that can be compiled on a UNIX machine. This converted version is used only temporarily at compile time. A set of supporting functions, emulating the current RPG API, is developed to provide data flow and processing control support. All inter-process data exchanges are implemented through message passing in the supporting functions. ''Wrapped'' by the new supporting functions, the tasks turn into independent, data driven and dynamically relocatable components that can be used in a distributed environment. RP Jing, ZQ (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 318 EP 324 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00039 ER PT B AU Dodson, AB Burcham, H AF Dodson, AB Burcham, H GP IEEE TI Method of validating ported NEXRAD RPG algorithms and product generators SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB The Next Generation Weather Radar (NEXRAD) Open Systems Radar Product Generation (ORPG) effort involves the porting of many working, tested, meteorological algorithms and product generators into an ''open'' and distributed workstation environment. We discuss the techniques used to validate the correctness of the ported software. This method is used to validate the ported software across a variety of platforms. Furthermore, the method is generic, accommodating future modifications of algorithms and product generators. RP Dodson, AB (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 325 EP 327 PG 3 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00040 ER PT B AU Priegnitz, D Frashier, D Marci, T OBannon, T Smith, S Steadham, R Bullard, M Rausch, M AF Priegnitz, D Frashier, D Marci, T OBannon, T Smith, S Steadham, R Bullard, M Rausch, M GP IEEE TI Human factors methods in the design of the graphical user interface for the open systems radar product generation (ORPG) component of the WSR-88D SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB A concerted effort is underway to develop and deploy an open systems solution to components of the Weather Surveillance Radar-1988 Doppler (WSR-88D). Several small working groups, or subteams, have been established to focus on specific areas within each component. One of these, the Graphical User Interface (GUI) Team, consists of a group of individuals possessing specialized knowledge in some important aspect of the presently deployed WSR-88D Unit Control Position (UCP), human factors concepts, and GUI design. The UCP is the user interface to the Radar Product Generation (RPG) component of the WSR-88D. The redesign and replacement of the UCP is an opportunity to reduce training requirements, improve aspects of interface functionality, and empower forecasters to intuitively monitor and control the operational WSR-88D. Within the framework of iterative design, members of the GUI Team have applied usability principles in a dedicated effort to make the human-computer interaction as easy to use as possible. The members of the GUI Team believe that usability should be incorporated early in the system design project. As such, the GUI for the new UCP is evolving in an iterative manner, with a concept becoming a prototype which is then reviewed by the members of the GUI Team. As this effort evolves, it is anticipated that actual users will get involved in testing the various components of the user interface, providing valuable feedback to the GUI Team. RP Priegnitz, D (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 328 EP 331 PG 4 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00041 ER PT B AU Belville, JD Berkowitz, EL Reed, JR AF Belville, JD Berkowitz, EL Reed, JR GP IEEE TI Operational support facility (OSF) implementation and support of the WSR-88D open systems upgrade SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB Prototype developments for the rehost of the current Weather Surveillance Radar-1988 Doppler (WSR-88D) Radar Product Generation (RPG) and Radar Data Acquisition (RDA) platforms to Open Systems compliant platforms will be accomplished by teams outside of the Operational Support Facility (OSF). The OSF, however, will be responsible for the field implementation and operational support of the upgraded platforms. This paper presents details of the planning, training, and development activities involved with the OSF transition to Open Systems WSR-88D support. RP Belville, JD (reprint author), NOAA,DOC,NWS,OPERAT SUPPORT FACIL,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 332 EP 335 PG 4 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00042 ER PT B AU Radlein, R Lane, R AF Radlein, R Lane, R GP IEEE TI National weather service (NWS) operational impacts of the NEXRAD scientific and technical evolution in the AWIPS era SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB The National Weather Service (NWS) is in the process of developing and testing the initial implementation of the Advanced Weather Information Processing System(AWIPS). AWIPS will provide an expandable processing system capable of acquiring observational data from a variety of central and local sources, and including its manipulation and display as part of the end-to-end forecast process. The accessability of basic Weather Surveillance Radar-1988 Doppler (WSR-88D) products at each forecaster workstation is one of the earliest benefits AWIPS will provide. As the products and capabilities of the WSR-88D evolve, the need in the algorithm calculations for external data, available through AWIPS, will increase. At the same time, AWIPS will provide the core capabilities for NWS forecasters to see the improved WSR-88D products in ways never before possible. The evolutionary path of both these technologies must be carefully coordinated to enhance their benefits to forecast operations. This paper will provide an early look at the impacts expected from this symbiotic development. RP Radlein, R (reprint author), NOAA,NATL WEATHER SERV,METEOROL OFF,TECHNOL & FORECAST SYST CORE,1325 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 336 EP 340 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00043 ER PT B AU Zahrai, A Zrnic, D AF Zahrai, A Zrnic, D GP IEEE TI Implementation of polarimetric capability for the WSR-88D (NEXRAD) radar SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB A novel method to implement polarization diversity for the Weather Surveillance Radar-1988 Doppler (WSR-88D) is currently under development at the National Severe Storms Laboratory (NSSL). This method involves simultaneous transmission of two linearly polarized signals, and reception and processing of horizontal and vertical components using separate receivers. One of the primary advantages of this technique is that it does not compromise existing characteristics of the WSR-88D radar. However, implementation of this method requires major hardware modifications to the Radar Data Acquisition (RDA) functional area. These modifications will be implemented and tested on the Research WSR-88D at the NSSL. This paper describes system architecture and characteristics of the new design. RP Zahrai, A (reprint author), NOAA,NATL SEVERE STORMS LAB,ERL,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 346 EP 351 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00045 ER PT B AU OHara, PAG Seifert, HJ AF OHara, PAG Seifert, HJ BE Spear, KE TI Silicon nitride: New thermochemical results SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE RP OHara, PAG (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 258 EP 258 PG 1 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00032 ER PT B AU Hastie, JW Paul, AJ Bonnell, DW Schenck, PK AF Hastie, JW Paul, AJ Bonnell, DW Schenck, PK BE Spear, KE TI High temperature chemistry of the pulsed laser thin film deposition process SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE AB The pulsed laser deposition (PLD) process is characterized by the interplay of complex high temperature physicochemical phenomena occurring over a wide range of time, space, species concentration, and energy. Based on the results of recent work in our laboratory, together with what is known from the published literature, we examine, here, the current status of understanding of the PLD process, particularly with respect to high temperature chemistry measurements and models. A number of subprocesses contribute to the overall process. What is known and what remains to be determined for each of these subprocesses is considered. The deposition materials of interest are typically complex oxides, carbides, and nitrides, for which control of stoichiometry and intermediate species kinetic energies are particularly critical to the mode of film growth and optimization of film properties. RP Hastie, JW (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,BLDG 223,RM A215,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 547 EP 555 PG 9 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00070 ER PT B AU Hastie, JW Bonnell, DW Paul, AJ Schenck, PK Ranjan, A Sinha, S Ghosh, PK AF Hastie, JW Bonnell, DW Paul, AJ Schenck, PK Ranjan, A Sinha, S Ghosh, PK BE Spear, KE TI Monte Carlo simulations of plume evolution from laser ablation of graphite and barium titanate SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE AB Evolution of laser ablation products from graphite and barium titanate targets has been simulated using a Monte Carlo method, assuming elastic collisions. The calculated species arrival times and intensities, at a hypothetical detection plane, compare favorably with those obtained experimentally by time resolved mass spectrometric sampling of the expanded vapor plumes. As such experiments are difficult to perform, the simulation method should prove useful for as yet unstudied systems in defining the spatial and temporal distributions of species arriving at a film deposition substrate, for example. RP Hastie, JW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 580 EP 586 PG 7 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00074 ER PT B AU Trueblood, DD Ozturgut, E Pilipchuk, M Gloumov, IF AF Trueblood, DD Ozturgut, E Pilipchuk, M Gloumov, IF BE Chung, JS TI The ecological impacts of the joint US-Russian benthic impact experiment SO PROCEEDINGS OF THE SECOND (1997) ISOPE OCEAN MINING SYMPOSIUM LA English DT Proceedings Paper CT 2nd ISOPE Ocean Mining Symposium CY NOV 24-25, 1997 CL SEOUL, SOUTH KOREA SP Int Soc Offshore & Polar Engineers, Int Org Comm, Korea Comm Ocean Resources & Engn, Korea Assoc Deep Ocean Minerals Dev DE deep sea; benthic impact experiment; mining; benthos; multivariate similarity analysis AB The Benthic Impact Experiment (BIE) is designed to address the effects of sediment redeposition prior to the commencement of commercial mining in the deep sea. Sediment resuspension and subsequent redeposition during manganese-nodule mining is predicted to be the primary impact on benthic communities living on the abyssal seafloor. Sediment redeposition could adversely affect abyssal benthic communities through entombment, spatio-temporal changes in recruitment patterns, or through starvation caused by food dilution and obstructed feeding. NOAA started the BIE with baseline studies in July 1993 with the deployment of a transponder net and current meters, and by conducting side scan sonar/camera surveys, and benthic sampling. Following the baseline activities the study area was blanketed with varying thicknesses of sediment using the Disturber. In the BIE, the Disturber was towed 49 times through a 150-m-x-3,000-m tow zone resuspending 4,000 m(3) of wet sediment. The bulk of the resuspended material was transported north of the tow zone by northerly currents at the time of disturbance. The majority of the discharged sediment settled quickly as a sediment-laden fluid flow. After towing, samples were randomly collected in the area of heaviest resedimentation to determine the impacts on macro-and meiofauna immediately after towing and one year later in 1994. Meiofaunal analyses indicate that nematodes exhibit a significant decrease in abundance in the sediment redeposition area 9 months after the initiation of the BIE. Macrofaunal data analysis conducted at the family level indicated that only Sabellid polychaetes and Macrostylid isopods exhibit a significant treatment affect that could be attributed to sediment redeposition. Multivariate community similarity analysis reveals that the glycerid polychaete Glycera sp. A was positivily associated with samples collected from the sediment redeposition zone immediately following the iniation of the experiment. In the deep sea, Glycerid polychaets are mobile scavangers/predators and their increased abundance in the sediment redeposition zone may be an indication of increased food availability immediately following the disturbance. However, overall species diversity remained unaffected by sediment redeposition. Although the majority of macrofaunal taxa seem to be unaffected by sediment redeposition in the BIE, Sabellid polychaetes, Macrostylid isopods, and the glycerid polychaete Glycera sp. A may be good candidates for monitoring sediment redeposition impacts in the deep sea. Interestingly, all three taxa showed increased abundances in the samples collected from the sediment redeposition area. For the meiofauna, nematodes appear to be a good candidate for monitoring mining related impacts on the benthos. The results of NOAA's BIE study indicate that the short-term far field effects of sediment redeposition may have been overestimated. The 1-2 cm of sediment burrial that occured north of the tow zone appears not to have had the catastrophic effect that was once predicted. Both meio- and macrofaunal animals appear to be capable of surviving in the sediment redeposition zone up to 9 months following the sediment redeposition impact. However, the long-term environmental effects of sediment redeposition in the deep sea remain unknown. C1 NOAA, Silver Spring, MD USA. RP Trueblood, DD (reprint author), NOAA, Silver Spring, MD USA. NR 0 TC 11 Z9 11 U1 0 U2 5 PU INTERNATIONAL SOCIETY OFFSHORE& POLAR ENGINEERS PI CUPERTINO PA PO BOX 189, CUPERTINO, CA 95015-0189 USA BN 1-880653-33-8 PY 1997 BP 139 EP 145 PG 7 WC Engineering, Marine; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA BK24E UT WOS:000071602000024 ER PT B AU Tilford, CR AF Tilford, CR BE Meyyappan, M Economou, DJ Butler, SW TI Optimizing residual gas analyzers for process monitoring SO PROCEEDINGS OF THE SECOND INTERNATIONAL SYMPOSIUM ON PROCESS CONTROL, DIAGNOSTICS, AND MODELING IN SEMICONDUCTOR MANUFACTURING SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 2nd International Symposium on Control, Diagnostics and Modeling in Semiconductor Manufacturing, at the 191st Meeting of the Electrochemical-Society CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Dielect Sci & Technol Div, Electrochem Soc, Electr Div, Lam Res Corp, Fremont CA, Texas Instruments Inc AB The versatility and sensitivity of Residual Gas Analyzers (RGAs) make them ideal for many process monitoring and control applications. However, under some conditions of use, space-charge effects can cause some RGAs to yield very unreliable results. This paper discusses the origins of these effects, and describes user-tests to determine if the instrument is space-charge-limited, as well as user-adjustment and calibration procedures that can significantly improve the performance. RP Tilford, CR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-136-6 J9 ELEC SOC S PY 1997 VL 97 IS 9 BP 184 EP 191 PG 8 WC Electrochemistry; Engineering, Electrical & Electronic SC Electrochemistry; Engineering GA BJ30U UT WOS:A1997BJ30U00022 ER PT S AU Trueblood, DD Ozturgut, E AF Trueblood, DD Ozturgut, E BE Chung, JS Das, BM Matsui, T Thiel, H TI The Benthic impact experiment: A study of the ecological impacts of deep seabed mining on abyssal benthic communities SO PROCEEDINGS OF THE SEVENTH (1997) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL I, 1997 SE International Offshore and Polar Engineering Conference Proceedings LA English DT Proceedings Paper CT 7th International Offshore and Polar Engineering Conference (ISOPE-97) CY MAY 25-30, 1997 CL HONOLULU, HI SP Int Soc Offshore & Polar Engineers DE deep sea; Benthic Impact Experiment; mining; benthos AB The Benthic Impact Experiment (BIE) is designed to address the effects of sediment redeposition prior to the commencement of commercial mining in the deep sea. The experiment is being conducted in collaboration with Russian scientists from the Yuzhmorgeologiya Association aboard the R/V YUZHMORGEOLOGIYA. Sediment resuspension and subsequent redeposition during manganese-nodule mining is predicted to be the primary impact on benthic communities living on the abyssal seafloor. Sediment redeposition could adversely affect abyssal benthic communities through entombment, spatio-temporal changes in recruitment patterns, or through starvation caused by food dilution and obstructed feeding. The Deep Sea Sediment Resuspension System was built by the National Oceanic and Atmospheric Administration (NOAA) to study the effects of sediment redeposition on the deep-sea benthos. Initial trials and experiments with the Deep Sea Sediment Resuspension System were conducted in 1991 and 1992. However the sediment redeposition results were not satisfactory; a second generation Deep Sea Sediment Resuspension System (Disturber) was manufactured and tested in 1993. The new Disturber fluidizes the sediments in the top layer, lifts the sediment slurry and discharges it 5 m above the seafloor. In July 1993 NOAA started the BIE with baseline studies which included deployment of a transponder net and current meters, and side scan sonar/camera surveys in the study area. In August 1993 the baseline current meters were recovered, baseline box core samples were randomly collected from the study area, and sediment traps and current meters with transmissometers were deployed. Following the baseline activities the 4900-m deep experimental area was blanketed with varying thicknesses of sediment using the Disturber. In the BIE, the Disturber was towed 49 times through a 150-m-x-3,000-m tow zone resuspending 4,000 m(3) of wet sediment. Northerly currents at the time of disturbance transported the bulk of resuspended sediment to the north as indicated by the sediment trap and transmissometer data. Results indicate that the discharged sediment did not travel far, settling quickly as a sedimentladen fluid flow. After towing, samples were randomly collected in the area of heaviest resedimentation to determine the impacts on macro- and meiofauna immediately after towing and one year later in 1994. Meiofuanal analyses indicate that nematodes exhibit a significant decrease in abundance in the sediment redeposition area 9 months after the initiation of the BIE. Of the 71 macrofaunal families analyzed, only Sabellid polychaetes and Macrostylid isopods exhibite a significant treatment affect that could be attributed to the sediment redeposition. Overall species diversity remained unaffected by sediment redeposition. RP Trueblood, DD (reprint author), NOAA, SILVER SPRING, MD USA. NR 0 TC 10 Z9 10 U1 0 U2 6 PU INTERNATIONAL SOCIETY OFFSHORE& POLAR ENGINEERS PI CUPERTINO PA PO BOX 189, CUPERTINO, CA 95015-0189 USA SN 1098-6189 BN 1-880653-29-X J9 INT OFFSHORE POLAR E PY 1997 BP 481 EP 487 PG 7 WC Engineering, Environmental; Engineering, Marine; Engineering, Civil; Engineering, Petroleum SC Engineering GA BJ14B UT WOS:A1997BJ14B00071 ER PT B AU Giachetti, RE Young, RE AF Giachetti, RE Young, RE GP IEEE TI Analysis of variability in the design of wood products under imprecision SO PROCEEDINGS OF THE SIXTH IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS, VOLS I - III LA English DT Proceedings Paper CT 6th IEEE International Conference on Fuzzy Systems (FUZZ-IEEE 97) CY JUL 01-05, 1997 CL BARCELONA, SPAIN SP IEEE, Neural Network Council DE engineering design; constraint satisfaction; fuzzy analysis; fuzzy constraints; decision support tool AB The design and analysis of many products is performed with imprecisely known parameters, relationships, and environmental conditions. This is especially true for wood products which exhibit,greater variability than most materials. Fuzzy set theory applied to the design and analysis of wood products is regarded as a promising approach for modeling the geometric and mechanical property variability. A fuzzy constraint model is used to analyze the design of a wood beam structure. The analysis is compared with a Monte-Carlo simulation and a root sum of squares analysis approach. The fuzzy set design approach compares favorably with these approaches and has several distinct advantages. It can model user preference as well as imprecision, it is computationally quick, and it better reduces the design space. RP Giachetti, RE (reprint author), NIST,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3797-2 PY 1997 BP 1203 EP 1208 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Multidisciplinary SC Automation & Control Systems; Computer Science; Engineering GA BJ56L UT WOS:A1997BJ56L00195 ER PT B AU Vilker, VL Wong, LS Grayson, D Reipa, V AF Vilker, VL Wong, LS Grayson, D Reipa, V BE Weaver, RD Fisher, F Kalhammer, FR Mazur, D TI Synthesis of oxygenated hydrocarbons by cytochrome P450 electroenzymology SO PROCEEDINGS OF THE SYMPOSIUM ON FUNDAMENTALS AND POTENTIAL APPLICATIONS OF ELECTROCHEMICAL SYNTHESIS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Fundamentals and Potential Applications of Electrochemical Synthesis CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Natl Sci Fdn, Elect Power Res Inst AB Direct electron transfer between catalytic cytochrome P-450 proteins and electrodes has been carried out for the purpose of running economical synthesis of valuable oxygenated hydrocarbons. This presentation discusses recent progress involved with achieving this goal, namely: i) the determination of the thermochemical cycle, stoichiometry, product distributions and kinetics of the hydroxylation of a potentially valuable cycloarene (1-tetralol) by NADH-driven P-450(cam) catalysis, ii) the development of modified electrodes for regeneration of a key electron transfer protein in the P-450(cam) cycle, and iii) the demonstration of electrochemical turnover of the P-450(cam) catalytic cycle for the conversion of its natural substrate camphor. RP Vilker, VL (reprint author), NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-133-1 J9 ELEC SOC S PY 1997 VL 97 IS 6 BP 91 EP 99 PG 9 WC Chemistry, Applied; Electrochemistry SC Chemistry; Electrochemistry GA BH74T UT WOS:A1997BH74T00010 ER PT B AU Nguyen, NV Richter, CA AF Nguyen, NV Richter, CA BE Deen, MJ Brown, WD Sundaram, KB Raider, SI TI Thickness determination of ultra-thin SiO2 films on Si by spectroscopic ellipsometry SO PROCEEDINGS OF THE SYMPOSIUM ON SILICON NITRIDE AND SILICON DIOXIDE THIN INSULATING FILMS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Silicon Nitride and Silicon Dioxide Thin Insulating Films CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Dielect Sci & Technol Div, Electrochem Soc, Electr Div AB For ultra-thin SiO2 films with thicknesses Less than 100 Angstrom on Si, the accurate determination of the thickness and the index of refraction is a technologically important issue because of the strict tolerances required for the fabrication of sub-micrometer integrated circuit (IC) devices. Ellipsometry is traditionally and commonly employed to determine these quantities. In this study, we use spectroscopic ellipsometry (SE) to measure a set of device quality SiO2 films ranging from 45 Angstrom to 2000 Angstrom in thickness. We demonstrate that a variety of models for the oxide index of refraction together with different sets of the silicon substrate dielectric functions fit the measured SE data comparably well. We show, however, that the resulting variations (relative error) in derived thickness and refractive index of oxide films thinner than 100 Angstrom can be as large as 23% and 13%, respectively. RP Nguyen, NV (reprint author), NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-137-4 J9 ELEC SOC S PY 1997 VL 97 IS 10 BP 183 EP 193 PG 11 WC Electrochemistry; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA BJ51X UT WOS:A1997BJ51X00015 ER PT B AU Niaura, G Gaigalas, AK Vilker, VL AF Niaura, G Gaigalas, AK Vilker, VL BE Korzeniewski, C Conway, BE TI Adsorption of phosphate anions on gold electrodes modified by underpotentially deposited silver adatoms: Surface-enhanced Raman spectroscopic study SO PROCEEDINGS OF THE SYMPOSIUM ON THE ELECTROCHEMICAL DOUBLE LAYER SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on the Electrochemical Double Layer, at the 191st ECS Meeting CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Electrochem Div AB The adsorption of phosphate anions on Au electrodes modified by underpotentially deposited (UPD) Ag adatoms has been studied by surface-enhanced Raman spectroscopy (SERS). It was found that the presence of Ag adatoms extends the potential range over which phosphate anions are adsorbed on the modified Au electrode. The range is extended by 0.9 V to more negative potentials. The frequency of the metal-oxygen vibrational mode indicates that the phosphate anions are coordinated with the Ag adatoms rather than with the Au atoms. Spectroscopic data also suggest that adsorption geometry of anions bound to UPD Ag is similar to that found in the case of bare Ag electrodes. The frequency of the internal asymmetric stretching vibration is found to be sensitive to the coverage of UPD Ag adatoms(at the same potential). RP Niaura, G (reprint author), NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-144-7 J9 ELEC SOC S PY 1997 VL 97 IS 17 BP 409 EP 417 PG 9 WC Electrochemistry SC Electrochemistry GA BK03D UT WOS:A1997BK03D00030 ER PT B AU Evans, CJ Sullivan, PJ Parks, RE Estler, WT Shao, LZ AF Evans, CJ Sullivan, PJ Parks, RE Estler, WT Shao, LZ GP AMER SOC PRECIS ENGN AMER SOC PRECIS ENGN TI Multi-step form metrology: principles and applications to the LIGO Pathfinder optics SO PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 12th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 05-10, 1997 CL NORFOLK, VA SP Amer Soc Precis Engn, Elsevier Sci Inc, Photon Spectra C1 Natl Inst Stand & Technol, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Evans, CJ (reprint author), Natl Inst Stand & Technol, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-18-6 PY 1997 BP 29 EP 32 PG 4 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BM12N UT WOS:000077690100005 ER PT B AU Rhorer, RL Copeland, NR Brooks, CW Dutterer, BS AF Rhorer, RL Copeland, NR Brooks, CW Dutterer, BS GP AMER SOC PRECIS ENGN AMER SOC PRECIS ENGN TI The machinist's role in a modern high-precision manufacturing enterprise SO PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 12th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 05-10, 1997 CL NORFOLK, VA SP Amer Soc Precis Engn, Elsevier Sci Inc, Photon Spectra AB It has been suggested that as better systems are developed for controlling manufacturing processes, the need for the skilled machinist will decrease. The authors of this paper argue there will be an increasing role in high-precision manufacturing enterprises for people with the skills of the precision machinist. C1 NIST, Fabricat Technol Div, Gaithersburg, MD 20899 USA. RP Rhorer, RL (reprint author), NIST, Fabricat Technol Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-18-6 PY 1997 BP 410 EP 413 PG 4 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BM12N UT WOS:000077690100096 ER PT B AU Phillips, SD Borchardt, B Sawyer, D Estler, WT Ward, D Eberhardt, K Levenson, MS McClain, M Melvin, B Hopp, T Shen, Y AF Phillips, SD Borchardt, B Sawyer, D Estler, WT Ward, D Eberhardt, K Levenson, MS McClain, M Melvin, B Hopp, T Shen, Y GP AMER SOC PRECIS ENGN AMER SOC PRECIS ENGN TI The calculation of CMM measurement uncertainty via the method of simulation by constraints SO PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 12th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 05-10, 1997 CL NORFOLK, VA SP Amer Soc Precis Engn, Elsevier Sci Inc, Photon Spectra C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Phillips, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-18-6 PY 1997 BP 443 EP 446 PG 4 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BM12N UT WOS:000077690100104 ER PT B AU Davies, MA Chou, YK Evans, CJ AF Davies, MA Chou, YK Evans, CJ GP AMER SOC PRECIS ENGN AMER SOC PRECIS ENGN TI Research challenges and directions in precision machining of hardened steels SO PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Meeting Abstract CT 12th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 05-10, 1997 CL NORFOLK, VA SP Amer Soc Precis Engn, Elsevier Sci Inc, Photon Spectra C1 NIST, Gaithersburg, MD 20899 USA. RP Davies, MA (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-18-6 PY 1997 BP 451 EP 451 PG 1 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BM12N UT WOS:000077690100106 ER PT B AU Rhorer, RL Rhorer, JL AF Rhorer, RL Rhorer, JL GP AMER SOC PRECIS ENGN AMER SOC PRECIS ENGN TI Precision engineering and statistics: Is there any common ground? SO PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 12th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 05-10, 1997 CL NORFOLK, VA SP Amer Soc Precis Engn, Elsevier Sci Inc, Photon Spectra AB The term "Statistical Process Control (SPC)" Is very well known in the field of precision manufacturing. Yet, precision engineers (very much involved in precision manufacturing) do not often incorporate SPC methodology in their work. Why? we present here a search for a common ground between precision engineering and statistics. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rhorer, RL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-18-6 PY 1997 BP 452 EP 453 PG 2 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BM12N UT WOS:000077690100107 ER PT B AU Jones, RK AF Jones, RK GP EC EC TI A simplified pseudo-component oil evaporation model SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB Evaporation usually dominates the loss processes during the first few days following a marine oil spill. Consequently, an oil evaporation model can be an important tool used in planning response strategies. In support of real-time oil spill response, a pseudo-component oil evaporation model is being developed to provide predictions of evaporation over the first 5 days following the accidental release of a crude oil or petroleum product. Results from the current model are compared with other models. Data requirements and characteristics of the models are discussed. A parametric sensitivity analysis is employed to estimate the operational limitations inherent in predicting evaporation during actual oil spills. C1 NOAA, Hazardous Mat Response & Assessment Div, Seattle, WA USA. RP Jones, RK (reprint author), NOAA, Hazardous Mat Response & Assessment Div, Seattle, WA USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 43 EP 61 PG 5 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200003 ER PT B AU McGrattan, KB AF McGrattan, KB GP EC EC TI Smoke plume trajectory from in situ burning of crude oil: Complex terrain modeling SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB As part of the process of obtaining preapproval for the use of in situ burning in the event of an oil spill, numerical models have been used to predict the concentration of particulate matter or other combustion products downwind of the fire. The NIST model, ALOFT (A Large Outdoor Fire plume Trajectory), is based on the conservation equations that govern the introduction of hot gases and particulate matter from a large fire into the atmosphere. Because it is based on the fundamental equations rather than empirical correlations, simulations of burning in areas of very mountainous terrain, like the southern Alaskan coast, can be handled very easily using digitized terrain data at roughly 100 m resolution. The model has been applied to regions in Alaska, and predictions of distances from the fire where combustion product concentrations fall below ambient air quality standards have been made. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McGrattan, KB (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 723 EP 734 PG 4 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200045 ER PT B AU Walton, WD Twilley, WH Mullin, JV AF Walton, WD Twilley, WH Mullin, JV GP EC EC TI An evaluation of propane as a fuel for testing fire-resistant oil spill containment booms SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB As the understanding of the capabilities and limitations of in situ burning of oil spills increases, in situ burning continues to gain acceptance as a potential oil spill mitigation tool. Most plans for burns at sea call for the use of a fire-resistant boom to contain the oil during burning. Presently a standard method for evaluating fire-resistant booms does not exist. Most of the proposed test methods and experiments conducted to evaluate fire-resistant booms utilize liquid hydrocarbon fuels for the fire exposure. While these fuels can generate realistic thermal exposures, the smoke emitted from these fires presents environmental concerns and limits the location and conditions under which tests can be conducted. Propane bubbled through water is being widely used to replace liquid hydrocarbon pool fires for fire fighter training. A series of experiments has been conducted to measure and compare the thermal exposure to a fire-resistant boom from liquid hydrocarbon fuel and propane fires. In addition, the thermal exposures from propane fires have been measured with and without waves. Although propane diffusion flames on water look like liquid hydrocarbon fuel flames and produce very little visible smoke, the heat flux at the boom location from the propane fires is approximately 60% of that fi om liquid hydrocarbon fuel fires. C1 US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Gaithersburg, MD 20899 USA. RP Walton, WD (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Gaithersburg, MD 20899 USA. NR 2 TC 2 Z9 2 U1 0 U2 1 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 755 EP 767 PG 3 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200047 ER PT B AU Simecek-Beatty, DA Lehr, WJ Lankford, JF AF Simecek-Beatty, DA Lehr, WJ Lankford, JF GP EC EC TI Leaking tankers: How much oil was spilled? SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada ID PROCESS VESSELS; PUNCTURE AB Based on earlier work with draining tanks and with recent laboratory experiments, a simple model has been developed to estimate leak rates from tankers. The model includes algorithms for gravity outflow and air and water ingestion. The model is specifically designed for emergencies when more direct oil-loss estimation methods, such as tank soundings, are unavailable. C1 Natl Ocean & Atmospher Adm, Hazardous Mat Response & Assessment Div, Seattle, WA USA. RP Simecek-Beatty, DA (reprint author), Natl Ocean & Atmospher Adm, Hazardous Mat Response & Assessment Div, Seattle, WA USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 841 EP 851 PG 3 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200052 ER PT B AU Lehr, WJ AF Lehr, WJ GP EC EC TI Modeling the benzene inhalation hazard from spilled oil SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB Three different possible models for evaporation of benzene from an oil slick are examined in this paper. Each of these hypothesize a different control mechanism to restrict benzene release from the slick. First is the well-mixed case where the concentration of benzene is presumed to be uniform throughout the slick. The evaporation rate is then controlled by an air-liquid mass transfer coefficient and the benzene vapor pressure over the oil. The second case looks at the diffusion limited circumstance where there develops a vertical gradient of the benzene concentration in the slick. This is based on the assumption that benzene cannot migrate fast enough through the oil to reestablish the uniformity in concentration disrupted by benzene evaporation from the surface. The third case postulates a well-mixed case except for a thin surface crust which supports a steep concentration gradient. The evaporation models, combined with an air dispersion model, provide airborne benzene estimates. Results an compared with experiments in Mobile Bay. C1 NOAA, HAZMAT, Seattle, WA 98115 USA. RP Lehr, WJ (reprint author), NOAA, HAZMAT, Seattle, WA 98115 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 853 EP 861 PG 5 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200053 ER PT B AU Helton, D Penn, T Hicks, R AF Helton, D Penn, T Hicks, R GP EC EC TI The cost of oil spills: Putting response and natural resource damage costs in perspective SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB The overall cost of oil spills is of great interest to industry, responders, and regulators, but relatively few incidents have been examined in detail. Furthermore, publicly available cost data are often limited to State and Federal response costs and natural resource damage settlements. Significant categories of costs, such as private response costs, third party claims, and vessel or facility repair costs, are often not available. Failure to consider these additional cost categories may result in erroneous conclusions regarding the overall cost of spills and the relative significance of any one cost category. We summarize the general categories of costs that may result from spill incidents. Finally, we present and discuss the costs for a number of incidents representing a range of spill volumes and locations. C1 Natl Ocean & Atmospher Adm, Seattle, WA USA. RP Helton, D (reprint author), Natl Ocean & Atmospher Adm, Seattle, WA USA. NR 27 TC 0 Z9 0 U1 0 U2 1 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 981 EP 993 PG 5 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200059 ER PT B AU Helton, D Hope, H AF Helton, D Hope, H GP EC EC TI Opening doors to natural resource damage assessments: Public participation under the Oil Pollution Act of 1990 SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB Until recently, the natural resource damage assessment process following oil spills was conducted behind closed doors. Studies were conducted under the cloak of litigation and the public and response community were often unaware or unable to review the information collected or evaluate the technical basis for the settlement reached. In some instances, data were kept confidential even after the case was closed. In January of 1996 this paradigm was reversed by the new regulations issued by the National Oceanic and Atmospheric Administration under the Oil Pollution Act of 1990 (OPA). These rules outline a more open assessment process to facilitate both a cooperative assessment effort with the responsible party, and opportunities for meaningful participation in the decision-making process by the public. This paper examines the first test of this new assessment process: the January 1996 spill from the T/B North Cape in Rhode Island.(1). C1 Natl Ocean & Atmospher Adm, Seattle, WA USA. RP Helton, D (reprint author), Natl Ocean & Atmospher Adm, Seattle, WA USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 995 EP 1001 PG 3 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200060 ER PT B AU Helton, D Michel, J Reilly, TJ AF Helton, D Michel, J Reilly, TJ GP EC EC TI Incorporating oil behavior in the design of natural resource damage assessment studies: Three case histories SO PROCEEDINGS OF THE TWENTIETH ARCTIC AND MARINE OILSPILL PROGRAM (AMOP) TECHNICAL SEMINAR, VOLS 1 AND 2 LA English DT Proceedings Paper CT 20th Arctic and Marine Oilspill Program Technical Seminar CY JUN 11-13, 1997 CL VANCOUVER, CANADA SP Environm Protect Serv, Environm Technol Advancement Directorate, Environm Canada AB Understanding the behavior and properties of spilled oil is as critical to the natural resource damage assessment process as it is to the effective response and cleanup of spills. Three incidents, the TN Julie N spill in Maine and the T/B North Cape and the TN World Prodigy spills in Rhode Island represent three distinct spill scenarios, separated largely because of different sets of oil properties, physical conditions at the time of the release, and thus oil behavior. In this paper we summarize these recent spill experiences and describe how an understanding of the behavior of the oil was critical in designing the assessment studies and evaluating the impacts of the spills. C1 Natl Ocean & Atmospher Adm, Seattle, WA USA. RP Helton, D (reprint author), Natl Ocean & Atmospher Adm, Seattle, WA USA. NR 30 TC 0 Z9 0 U1 0 U2 1 PU ENVIRONMENT CANADA PI OTTAWA PA OTTAWA, ON K1A OH3, CANADA PY 1997 BP 1003 EP 1014 PG 6 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BP62A UT WOS:000085691200061 ER PT B AU McCrary, VR AF McCrary, VR BE Chu, SNG Buckley, DN Wada, K Vilcot, JP Pletschen, W DeCoster, D VanDaele, P Hou, HQ TI Manufacturing infrastructure for optoelectronics SO PROCEEDINGS OF THE TWENTY-SEVENTH STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS (SOTAPOCS XXVII) SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 27th State-of-the-Art Program on Compound Semiconductors (SOTAPOCS XXVII), at the 192nd Meeting of the Electrochemical-Society CY AUG 31-SEP 05, 1997 CL PARIS, FRANCE SP Electrochem Soc Inc, Electr Div AB Optoelectronics is the enabling technology for information generation, information transmission, and information storage. Components from semiconductor lasers, LEDs, and passive couplers and connectors will be needed in large volumes at low cost as increased demand for bandwidth mounts. For example, a target of delivering 1 Gbps, at $10/Gbit is the goal for acceptance of consumer information services at the premise level. However, the U.S. optoelectronics industry operates to a large degree on small volume, custom products, where the yields are low, thus the price is beyond the reach of the average consumer. In order to achieve low-cost components, the U.S. optoelectronics community will need to make concerted efforts to make yield improvements in a number of areas: substrate characterization, epitaxial growth and characterization, packaging, and testing. Using the InP-based alloy semiconductor laser, this paper will briefly explore the markets, the current technological challenges, and possible solutions towards improving the current manufacturing process of this key component. RP McCrary, VR (reprint author), NATL INST STAND & TECHNOL,INFORMAT TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-149-8 J9 ELEC SOC S PY 1997 VL 97 IS 21 BP 51 EP 63 PG 13 WC Electrochemistry SC Electrochemistry GA BJ30W UT WOS:A1997BJ30W00004 ER PT J AU Hsueh, Y Schultz, JR Holland, WR AF Hsueh, Y Schultz, JR Holland, WR TI The Kuroshio flow-through in the East China Sea: A numerical model SO PROGRESS IN OCEANOGRAPHY LA English DT Review ID CONTINENTAL-SHELF NORTHEAST; OCEAN HEAT-TRANSPORT; PACIFIC-OCEAN; TAIWAN; DYNAMICS; 24-DEGREES-N; RESOLUTION; KYUSHU; BRANCH; WATER AB The Bryan-Cox model of general ocean circulation is adapted to the East China Sea to study the flow-through of the Kuroshio. The model domain lies between 22 degrees N and 35 degrees N and between 119 degrees E and 135 degrees E, with a horizontal grid size of 1/6 degrees and a vertical resolution provided by 30 levels so placed as to represent adequately the rapid change in bottom topography over the upper continental slope that underlies the Kuroshio. The model is driven by a steady inflow and outflow consistent with the Sverdrup transport calculated from the annual mean windstress field over the entire North Pacific. Temperature and salinity at the model sea surface are relaxed to the climatological values on a 50-day time scale. There is no locally imposed windstress. The model is initialized with the inflow-and-outflow-forced streamfunction field and climatological fields of temperature and salinity. The outflow condition is subsequently updated to reflect the redistribution suggested by the adjusted interior during the first year of integration. The model is then run with a combination of relaxation and radiation conditions along open boundaries for a total of six years, nearly five years beyond the time when the basin averaged kinetic energy reaches a constant value. In the final quasi-steady state, the model exhibits many of the patterns evident in observations, including a sharpened Kuroshio front over the upper continental slope, the countercurrent at about 200 m northeast of Taiwan, and the separation of the Kuroshio at about 30 degrees N. A budget calculation at the final state shows that about 5% of the net poleward heat transport carried by the Kuroshio across 24 degrees N in the North Pacific is routed through the marginal seas. Similarly, a salt flux about 5% of the net poleward transport carried by the Kuroshio across 24 degrees N is directed to the north into the Sea of Japan, making the East China Sea an important salt source for water mass formation at high latitudes in the North Pacific Ocean. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. NOAA, Natl Ocean Survey, Silver Spring, MD 20910 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. RP Hsueh, Y (reprint author), Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. NR 47 TC 24 Z9 29 U1 3 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1997 VL 39 IS 2 BP 79 EP 108 DI 10.1016/S0079-6611(97)00008-6 PG 30 WC Oceanography SC Oceanography GA 147VU UT WOS:000077518800001 ER PT J AU Benmouna, M Hammouda, B AF Benmouna, M Hammouda, B TI The zero average contrast condition: Theoretical predictions and experimental examples SO PROGRESS IN POLYMER SCIENCE LA English DT Review ID DYNAMIC LIGHT-SCATTERING; TERNARY POLYMER-SOLUTIONS; SMALL-ANGLE NEUTRON; RANDOM PHASE APPROXIMATION; POLYISOBUTYLENE + TOLUENE; SEMI-DILUTE SOLUTIONS; X-RAY-SCATTERING; POLY(METHYL METHACRYLATE); SPINODAL DECOMPOSITION; PSEUDOBINARY APPROXIMATION AB This paper deals with mixtures of homopolymers and copolymers in solvents under the zero average contrast condition. This condition is chosen in order to decouple the correlations due to polymer composition fluctuations from those due to polymer concentration fluctuations. This makes the measurement of these correlations much easier using techniques based on static light scattering, photoncorrelation spectroscopy, small angle neutron scattering, neutron spin echo or X-ray scattering. In the first part of the paper, a simple theoretical framework is developed to present the guidelines for the interpretation of the scattering data. In the second part, some experimental examples are discussed using the scattering techniques mentioned above. Data obtained from various systems involving alike (deuterated and ordinary) homopolymers and diblock copolymers as well as unalike species are considered. An example of mixtures of polyelectrolytes in aqueous solutions is also discussed within the framework of the zero average contrast condition. (C) 1997 Elsevier Science Ltd. C1 UNIV TLEMCEN, INST SCI & TECHNOL, DEPT PHYS, TILIMSEN, ALGERIA. NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RP MAX PLANCK INST POLYMER RES, POSTFACH 3148, D-55021 MAINZ, GERMANY. NR 100 TC 19 Z9 19 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6700 J9 PROG POLYM SCI JI Prog. Polym. Sci. PY 1997 VL 22 IS 1 BP 49 EP 92 DI 10.1016/S0079-6700(96)00004-4 PG 44 WC Polymer Science SC Polymer Science GA WJ319 UT WOS:A1997WJ31900002 ER PT J AU Glotzer, SC Poole, PH Coniglio, A Jan, N AF Glotzer, SC Poole, PH Coniglio, A Jan, N TI Non-monotonic temperature dependence of local dynamics and local energy upon cooling toward the Ising spin glass transition SO PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT LA English DT Article; Proceedings Paper CT International Seminar on the Dynamics of Glass Transition and Related Topics CY NOV 12-15, 1996 CL KYOTO, JAPAN SP Yukawa Inst Theoret Phys, Canon Inc, Inoue Fdn Sci, Japan Soc Promot Sci, Kajima Fdn, Kao Co, Murata Sci Fdn, Minist Educ, Japan, Nippon Sheet Glass Fdn Mat Sci & Engn, Ogasawara Fdn Promot Sci & Engn, Teijin Co, Ltd, Toray Sci Fdn ID MULTIDIMENSIONAL NMR; O-TERPHENYL; POLYSTYRENE; MOLECULES AB We have performed a detailed analysis of the local dynamics and local energies of the equilibrium, paramagnetic phase of the d = 2 and d = 3 +/-J Ising spin glass model. Here we discuss our recently reported observations(1)) that while the average flip rate and average energy decrease monotonically with decreasing temperature, both the hip rate and energy of an increasing fraction of spins increase as the glass transition is approached on cooling. These findings are consistent with recent experimental results for the frequency-dependent magnetic susceptibility of an insulating spin glass, which showed that the approach to the glass transition could be detected from the high frequency behavior. C1 UNIV WESTERN ONTARIO, DEPT APPL MATH, LONDON, ON N6A 5B7, CANADA. UNIV NAPLES, DIPARTIMENTO SCI FIS, I-80125 NAPLES, ITALY. ST FRANCIS XAVIER UNIV, DEPT PHYS, ANTIGONISH, NS B2G 2W5, CANADA. RP NATL INST STAND & TECHNOL, CTR THEORET & COMPUTAT MAT SCI, GAITHERSBURG, MD 20899 USA. RI Poole, Peter/C-7943-2009 OI Poole, Peter/0000-0001-5985-0585 NR 19 TC 0 Z9 0 U1 0 U2 2 PU PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE PI KYOTO PA C/O KYOTO UNIV, YUKAWA HALL, KYOTO, 606-8502, JAPAN SN 0375-9687 J9 PROG THEOR PHYS SUPP JI Prog. Theor. Phys. Suppl. PY 1997 IS 126 BP 383 EP 386 PG 4 GA XK524 UT WOS:A1997XK52400072 ER PT B AU Charnotskii, MI AF Charnotskii, MI BE Bissonnette, LR Dainty, C TI Short-exposure imaging and short-term laser beam spread in a turbulent atmosphere. SO PROPAGATION AND IMAGING THROUGH THE ATMOSPHERE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Propagation and Imaging through the Atmosphere CY JUL 29-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE imaging; beam propagation; atmospheric turbulence AB The theory of short-exposure (SE) imaging and short-term (ST) beam spread is developed based on the Markov approximation for wave propagation in turbulence and Feynman path-integral formalism. The theory is not restricted by the weak scintillation conditions, and takes into account diffraction and geometric properties of the beam and imaging system. We obtain approximations for the ST beam and SE image structure functions, which are free from the drawbacks of the classical SE theory. The SE case modulation transfer function (MTF) has a two-scale shape with larger scale extending up to the diffraction cutoff. We show that the imaging system can be optimized to maintain the highest contrast for the given spatial frequency. The initial beam size and its focusing can be optimized in terms of the maximum on-axis intensity and minimum beam size. These effects have no analogy for the long-term cases. RP Charnotskii, MI (reprint author), NOAA,ENVIRONM TECHNOL LAB,SCI & TECHNOL CORP,325 BROADWAY,BOULDER,CO 80303, USA. RI Charnotskii, Mikhail/A-7193-2013 OI Charnotskii, Mikhail/0000-0002-8315-8254 NR 0 TC 3 Z9 4 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2547-8 J9 P SOC PHOTO-OPT INS PY 1997 VL 3125 BP 252 EP 262 DI 10.1117/12.279026 PG 3 WC Meteorology & Atmospheric Sciences; Optics SC Meteorology & Atmospheric Sciences; Optics GA BJ67Z UT WOS:A1997BJ67Z00024 ER PT B AU Boisvert, RF Pozo, R Remington, K Barrett, RF Dongarra, JJ AF Boisvert, RF Pozo, R Remington, K Barrett, RF Dongarra, JJ BE Boisvert, RF TI Matrix market: A web resource for test matrix collections SO QUALITY OF NUMERICAL SOFTWARE - ASSESSMENT AND ENHANCEMENT LA English DT Proceedings Paper CT IFIP TC2/WG2.5 Working Conference on the Quality of Numerical Software - Assessment and Enhancement CY JUL 08-12, 1996 CL OXFORD, ENGLAND SP Int Federat Informat Proc, Working Grp 2.5 DE numerical linear algebra; mathematical software; sparse matrices; testing and evaluation; reference data; test corpora; World Wide Web AB We describe a repository of data for the testing of numerical algorithms and mathematical software for matrix computations. The repository is designed to accommodate both dense and sparse matrices, as well as software to generate matrices. It has been seeded with the well-known Harwell-Boeing sparse matrix collection. The raw data files have been augmented with an integrated World Wide Web interface which describes the matrices in the collection quantitatively and visually. For example, each matrix has a Web page which details its attributes, graphically depicts its sparsity pattern, and provides access to the matrix itself in several formats. In addition, a search mechanism is included which allows retrieval of matrices based on a variety of attributes, such as type and size, as well as through free-text search in abstracts. RP Boisvert, RF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Dongarra, Jack/E-3987-2014 NR 0 TC 66 Z9 66 U1 0 U2 0 PU CHAPMAN & HALL PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN BN 0-412-80530-8 PY 1997 BP 125 EP 137 PG 13 WC Computer Science, Software Engineering SC Computer Science GA BH18B UT WOS:A1997BH18B00009 ER PT B AU Lozier, DW AF Lozier, DW BE Boisvert, RF TI A proposed software test service for special functions SO QUALITY OF NUMERICAL SOFTWARE - ASSESSMENT AND ENHANCEMENT LA English DT Proceedings Paper CT IFIP TC2/WG2.5 Working Conference on the Quality of Numerical Software - Assessment and Enhancement CY JUL 08-12, 1996 CL OXFORD, ENGLAND SP Int Federat Informat Proc, Working Grp 2.5 DE comparison software; interval relative precision; parallel computing; reference software; special functions; testing and evaluation; World Wide Web AB This is a proposal to develop a software test service at the National Institute of Standards and Technology for use in testing the accuracy, or numerical precision, of mathematical software for special functions. The service would use the World Wide Web to receive test requests and return test results. The tests would be run on a network of workstations at the Institute. It is hoped that such a service will be of practical utility to anyone who uses special functions in physics or other applications, and that it will stimulate the interest of applied mathematicians who are interested in the computation of special functions as well as computer scientists who are interested in innovative uses of the Internet. The author solicits comments on any aspect of the proposed service. RP Lozier, DW (reprint author), NATL INST STAND & TECHNOL,APPL & COMPUTAT MATH DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU CHAPMAN & HALL PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN BN 0-412-80530-8 PY 1997 BP 167 EP 178 PG 12 WC Computer Science, Software Engineering SC Computer Science GA BH18B UT WOS:A1997BH18B00013 ER PT S AU Buonsanto, MJ Bust, G Clark, R Codrescu, M Crowley, G Emery, BA Fuller-Rowell, TJ Hoogeveen, G Jacobson, A Knipp, D Maurits, S Richards, PG Taylor, JR Watkins, BJ AF Buonsanto, MJ Bust, G Clark, R Codrescu, M Crowley, G Emery, BA Fuller-Rowell, TJ Hoogeveen, G Jacobson, A Knipp, D Maurits, S Richards, PG Taylor, JR Watkins, BJ BE Rawer, K Bilitza, D TI Recent results of the cedar storm study SO QUANTITATIVE DESCRIPTION OF IONOSPHERIC STORM EFFECTS AND IRREGULARITIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4.2 Symposium on Quantitative Description of Ionospheric Storm Effects and Irregularities, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Int Union Radio Sci, UN Off Outer Space Affairs ID MAGNETIC STORM; JUNE 1991; POLAR-CAP; THERMOSPHERE; CONVECTION; IONOSPHERE AB The CEDAR storm study is a cooperative effort to study specific storm-intervals with particularly good data coverage. The aim is to involve interested scientists with F-region/thermosphere data or modelling capabilities in coordinated efforts to understand the coupled upper atmosphere regions at different heights and on a global scale. The major storms studied to date occurred in March 1990, June 1991,November 1993, and May 1995. In this paper the objectives and organization of the CEDAR Storm Study are described, and results from several recent projects are reported. These include attempts at a global description of high latitude ion convection related to magnetosphere changes; Joule and particle heating, neutral winds, temperatures, and composition; plasmaspheric irregularity imaging; ionospheric model validation; the relationship between SAR arcs, subauroral ion drift (SAID) events, and the ionospheric trough; high latitude patches and blobs; ionospheric storm effects observed by radio and optical tomographic techniques; upper thermosphere neutral winds at high and middle latitudes; and effects of energy transfer into the lower thermosphere and mesosphere on neutral winds. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 MIT, Haystack Observ, Westford, MA 01886 USA. Univ Texas, Appl Res Labs, Austin, TX 78713 USA. Univ New Hampshire, Dept Elect & Comp Engn, Kingsbury ECE, Durham, NH 03824 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. SW Res Inst, San Antonio, TX 78228 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Univ Alabama, Dept Comp Sci, Huntsville, AL 35899 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RP Buonsanto, MJ (reprint author), MIT, Haystack Observ, Westford, MA 01886 USA. NR 27 TC 7 Z9 7 U1 1 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043306-5 J9 ADV SPACE RES PY 1997 VL 20 IS 9 BP 1655 EP 1664 DI 10.1016/S0273-1177(97)00569-3 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38K UT WOS:000071955500001 ER PT J AU Tuck, AF Baumgardner, D Chan, KR Dye, JE Elkins, JW Hovde, SJ Kelly, KK Loewenstein, M Margitan, JJ May, RD Podolske, JR Proffitt, MH Rosenlof, KH Smith, WL Webster, CR Wilson, JC AF Tuck, AF Baumgardner, D Chan, KR Dye, JE Elkins, JW Hovde, SJ Kelly, KK Loewenstein, M Margitan, JJ May, RD Podolske, JR Proffitt, MH Rosenlof, KH Smith, WL Webster, CR Wilson, JC TI The Brewer-Dobson circulation in the light of high altitude in situ aircraft observations SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Review DE airborne observations; atmospheric chemistry; stratospheric circulation; troposphere stratosphere interaction ID ANTARCTIC OZONE HOLE; ARCTIC STRATOSPHERIC EXPEDITION; WINTER POLAR STRATOSPHERES; INSITU ER-2 DATA; WATER-VAPOR; SULFURIC-ACID; IRREVERSIBLE TRANSPORT; INFRARED-ABSORPTION; SIZE DISTRIBUTIONS; REACTIVE NITROGEN AB Fast response in situ measurements of a suite of chemical species made from the NASA ER2 high altitude aircraft, between 60 degrees N and 70 degrees S at potential temperatures up to 530 K from March to November 1994 at longitudes 115 degrees W to 150 degrees E, are considered for the view they offer of the Brewer-Dobson circulation in the lower stratosphere and upper troposphere. In the southern hemisphere, where most of the flights occurred, comparisons are made with measurements taken in August/September 1987 at longitudes 120 degrees W to 60 degrees W to examine temporal and longitudinal differences. Interpretations made suggest conceptual modifications to the simple construct of advection in a two-dimensional long-term mean. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV COLORADO,CIRES,BOULDER,CO 80309. CALTECH,JPL,PASADENA,CA 91125. UNIV WISCONSIN,MADISON,WI 53706. UNIV DENVER,DENVER,CO 80208. RP Tuck, AF (reprint author), NOAA,AERON LAB,US DEPT COMMERCE,ENVIRONM RES LABS,325 BROADWAY,BOULDER,CO 80303, USA. RI Tuck, Adrian/F-6024-2011; Rosenlof, Karen/B-5652-2008 OI Tuck, Adrian/0000-0002-2074-0538; Rosenlof, Karen/0000-0002-0903-8270 NR 116 TC 82 Z9 83 U1 1 U2 13 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 1997 VL 123 IS 537 BP 1 EP 69 PN A PG 69 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WE692 UT WOS:A1997WE69200001 ER PT J AU Jackson, ST Overpeck, JT Webb, T Keattch, SE Anderson, KH AF Jackson, ST Overpeck, JT Webb, T Keattch, SE Anderson, KH TI Mapped plant-macrofossil and pollen records of late quaternary vegetation change in eastern North America SO QUATERNARY SCIENCE REVIEWS LA English DT Review ID NORTHEASTERN UNITED-STATES; LAST GLACIAL MAXIMUM; SPRUCE PICEA-GLAUCA; PINE PINUS-STROBUS; WHITE-PINE; POSTGLACIAL VEGETATION; LOUISIANA-MISSISSIPPI; SOUTHWESTERN ONTARIO; ELEVATION VEGETATION; REGRESSION-ANALYSIS AB Macrofossil presence/absence maps and isopoll maps in 3000-year intervals show how ranges and abundance maxima for 12 eastern North American tree and shrub taxa (Picea, P. glauca, P. mariana, Larix laricina, Abies balsamea, Tsuga canadensis, Pinus strobus, P. resinosa, P. banksiana, Betula papyrifera, B. alleghaniensis, B. Series Humiles) have changed from the last glacial maximum to the present. The macrofossil maps corroborate patterns shown by the isopoll maps and provide spatial detail and taxonomic resolution. The macrofossils confirm the inference from pollen data that unglaciated southeastern North America was cooler during the last glacial maximum (18 and 15 ka) than simulated by the COHMAP experiments with the NCAR CCMO general circulation model. The geographic distribution of macrofossil occurrences during the Late glacial (12 and 9 ka) indicate that migration lag of boreal species did not occur at regional to subcontinental scales, and that pollen assemblages lacking modem analogs resulted from climate gradients lacking modem analogs. Early Holocene (9 and 6 ka) macrofossil maps show rapid northward expansion of tree species ranges into deglaciated regions. The data also show modest contractions of northern range limits of temperate species and expansions of southern range Limits of boreal species in response to cooling trends during the late Holocene (3 and 0 ka). Comparison of modem macrofossil maps of nine of these taxa with corresponding range maps confirm that the macrofossils record the geographic ranges accurately. Comparison of the modem macrofossil maps with maps of tree growing-stock volume shows that for some taxa (Abies, Tsuga) macrofossil occurrences were most frequent in regions of maximum tree abundance. Comparison of modem isopoll maps with the modern range and growing-stock volume maps indicate that, in contrast to the macrofossil data, the pollen data provide poorer resolution of range limits for most taxa, but better indications of abundance maxima and minima within the ranges. (C) 1997 Elsevier Science Ltd. C1 NO ARIZONA UNIV,DEPT BIOL SCI,FLAGSTAFF,AZ 86011. NOAA,NATL GEOPHYS DATA CTR,PALEOCLIMATOL PROGRAM,BOULDER,CO 80303. UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. NR 271 TC 141 Z9 143 U1 5 U2 27 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PY 1997 VL 16 IS 1 BP 1 EP 70 DI 10.1016/S0277-3791(96)00047-9 PG 70 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA WH643 UT WOS:A1997WH64300001 ER PT J AU Draxler, RR Jean, M Hicks, B Randerson, D AF Draxler, RR Jean, M Hicks, B Randerson, D TI Emergency preparedness - Regional specialised meteorological centres at Washington and Montreal SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 4th International Workshop on Real-Time Computing of the Environmental Consequences of an Accidental Release from a Nuclear Installation CY OCT, 1996 CL ARONSBORG, SWEDEN SP Commiss European Communities, US DOE, Off Emergency Management, Swedish Radiat Protect Inst AB The history and operations of a cooperative programme between the meteorological services of Canada and the United States to model the consequences of radioactive releases to the atmosphere are described. RP Draxler, RR (reprint author), NOAA,AIR RESOURCES LAB,1315 EAST WEST HWY,SILVER SPRING,MD 20910, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1997 VL 73 IS 1-4 BP 27 EP 30 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YE677 UT WOS:A1997YE67700007 ER PT J AU Randerson, D AF Randerson, D TI Emergency response planning at the Nevada Test Site SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 4th International Workshop on Real-Time Computing of the Environmental Consequences of an Accidental Release from a Nuclear Installation CY OCT, 1996 CL ARONSBORG, SWEDEN SP Commiss European Communities, US DOE, Off Emergency Management, Swedish Radiat Protect Inst AB A robust emergency response plan was an essential part of the underground testing of nuclear weapons at the United States Nevada Test Site (NTS). This plan was designed to help protect the safety and health of test operations personnel and the general public and to minimise social, economic, and environmental consequences in the event of an accidental release of radioactive material into the atmosphere. Meteorological information was a vital element in the formulation of this emergency response plan by a team of senior decision makers. The meteorological basis of the nuclear-test operations emergency response plan is described. Emphasis is placed on the complex, mobile, remote-sensing capability that was placed in the field prior to and during all underground nuclear tests. The system for the prompt electronic communication of these data to the test operations centre and the immediate processing, display, and real-time use of these data by test operations management is protrayed. In addition, the complete mesoscale meteorological monitoring program, including lightning detection, is described as well as how special mesoscale weather forecasts and test support products were produced and displayed for test management. The radiological assessment technique is summarised and the team effort between the weather forecaster, radiation fallout analyst, the United States Environmental Protection Agency radiological assessment team, and test management is outlined. A typical emergency response plan is described and the process for implementing the plan characterised. The rapid process for electronically displaying meteorological and radiological products on wide-screens during test operations is also described through visual examples. The paper offers a rare view of a comprehensive emergency response capability. RP Randerson, D (reprint author), AIR RESOURCES LAB,SPECIAL OPERAT & RES DIV,POB 94227,LAS VEGAS,NV 89193, USA. NR 2 TC 0 Z9 0 U1 1 U2 2 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1997 VL 73 IS 1-4 BP 247 EP 251 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YE677 UT WOS:A1997YE67700055 ER PT J AU Weatherhead, EC Webb, AR AF Weatherhead, EC Webb, AR TI International response to the challenge of measuring solar ultraviolet radiation SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID MARYLAND WATERMEN; OZONE DEPLETION; SKIN-CANCER; TRENDS; DEPENDENCE; SURFACE AB A great deal of scientific research is now being focused on measuring ultraviolet radiation. Directly measuring ultraviolet radiation is difficult, particularly when trying to achieve absolute accuracy of greater than 5%. Advances in instrumentation, calibration and monitoring procedures have improved the state of the art considerably in the past decade. However, a great many of the challenges facing this field are still being addressed by independent research efforts and collaborative approaches. An overview of the recent efforts in this field are covered as well as a review of present research goals and challenges. RP Weatherhead, EC (reprint author), NOAA,R E ARX1,325 BROADWAY,BOULDER,CO 80303, USA. RI Weatherhead, Elizabeth/I-7091-2015 OI Weatherhead, Elizabeth/0000-0002-9252-4228 NR 35 TC 13 Z9 13 U1 0 U2 1 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1997 VL 72 IS 3-4 BP 223 EP 229 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YC314 UT WOS:A1997YC31400007 ER PT J AU Verkouteren, RM Klinedinst, DB Currie, LA AF Verkouteren, RM Klinedinst, DB Currie, LA TI Iron-manganese system for preparation of radiocarbon AMS targets: Characterization of procedural chemical-isotopic blanks and fractionation SO RADIOCARBON LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; SAMPLE PREPARATION; C-14 MEASUREMENTS; GRAPHITE TARGETS; PERFORMANCE; REDUCTION; CARBON; NOSAMS AB We report a practical system to mass-produce accelerator mass spectrometry (AMS) targets with 10-100 mu g carbon samples. Carbon dioxide is reduced quantitatively to graphite on iron fibers via manganese metal, and the Fe-C fibers are melted into a bead suitable for AMS. Pretreatment, reduction and melting processes occur in sealed quartz tubes, allowing parallel processing for otherwise time-intensive procedures. Chemical and isotopic ((13)C, (14)C) blanks, target yields and isotopic fractionation were investigated with respect to levels of sample size, amounts of Fe and Mn, pretreatment and reduction time, and hydrogen pressure. With 7-day pretreatments, carbon blanks exhibited a lognormal mass distribution of 1.44 mu g (central mean) with a dispersion of 0.50 mu g (standard deviation). Reductions of 10 mu g carbon onto targets were complete in 3-6 h with all targets, after correction for the blank, reflecting the (13)C Signature of the starting material. The 100 mu g carbon samples required at least 15 h for reduction; shorter durations resulted in isotopic fractionation as a function of chemical yield. The trend in the (13)C data suggested the presence of kinetic isotope effects during the reduction. The observed CO(2)-graphite (13)C fractionation factor was 3-4% smaller than the equilibrium value in the simple Rayleigh model. The presence of hydrogen promoted methane formation in yields up to 25%. Fe-C beaded targets were made from NIST Standard Reference Materials and compared with graphitic standards. Although the (12)C ion currents from the beads were one to two orders of magnitude lower than currents from the graphite, measurements of the beaded standards were reproducible and internally consistent. Measurement reproducibility was limited mainly by Poisson counting statistics and blank variability, translating to (14)C uncertainties of 5-1% for 10-100 mu g carbon samples, respectively. A bias of 5-7% (relative) was observed between the beaded and graphitic targets, possibly due to variations in sputtering fractionation dependent on sample size, chemical form and beam geometry. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Verkouteren, RM (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 40 TC 18 Z9 18 U1 1 U2 2 PU UNIV ARIZONA DEPT GEOSCIENCES PI TUCSON PA RADIOCARBON 4717 E FORT LOWELL RD, TUCSON, AZ 85712 USA SN 0033-8222 J9 RADIOCARBON JI Radiocarbon PY 1997 VL 39 IS 3 BP 269 EP 283 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 103LY UT WOS:000075158500006 ER PT J AU Trevor, JL Hanley, L Lykke, KR AF Trevor, JL Hanley, L Lykke, KR TI Laser desorption/vacuum ultraviolet photoionization of alkanethiolate self-assembled monolayers SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID ION MASS-SPECTROMETRY; DIALKYL DISULFIDES; ORGANIC THIOLS; GOLD; SURFACES; FILMS AB Self assembled monolayers of straight-chain alkanethiolates (RS) on gold were studied by nitrogen laser desorption followed by vacuum ultraviolet (118 nm) photoionization of secondary neutrals in a time-of-flight mass spectrometer. The dominant feature of all photoionization mass spectra were the dimers (RSSR+) for all thiolates studied. No monomer ions (RS') were observed, in contrast with previous results from time-of-flight secondary ion and direct laser desorption mass spectrometry. Results are presented from experiments on the tetradecyl (C-14) and hexadecyl (C-16) mercaptan monolayers. Mixed C-14/C-16 monolayers generated both pure and mixed dimers, indicating a facile association between different monomer chain lengths. (C) 1997 by John Whey & Sons, Ltd. C1 UNIV ILLINOIS,DEPT CHEM,CHICAGO,IL 60607. ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899. NR 22 TC 16 Z9 16 U1 3 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 1997 VL 11 IS 6 BP 587 EP 589 DI 10.1002/(SICI)1097-0231(199704)11:6<587::AID-RCM877>3.0.CO;2-J PG 3 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WV616 UT WOS:A1997WV61600008 ER PT J AU Dalluge, JJ Nelson, BC Thomas, JB Welch, MJ Sander, LC AF Dalluge, JJ Nelson, BC Thomas, JB Welch, MJ Sander, LC TI Capillary liquid chromatography electrospray mass spectrometry for the separation and detection of catechins in green tea and human plasma SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID ELECTROCHROMATOGRAPHY; POLYPHENOLS AB The separation and detection of biologically active green tea catechins has been accomplished using capillary liquid chromatography/electrospray mass spectrometry (cLC/ESI-MS), Microscale determination (similar to 20 ng) of all six catechins in a green tea infusion, and the most extensively studied catechin, (-)epigallocatechin gallate (EGCG), in human plasma is demonstrated by cLC/ESI-MS with selected ion monitoring of protonated molecular ions. The overall quality of the analysis is shown to be dependent on the use of a capillary column with a deactivated, monomeric C-18 stationary phase, The high chromatographic separation efficiency of this packed-capillary column, combined with the high sensitivity and selectivity afforded by the mass spectrometer as detector, provide a reliable approach to the analysis of picomolar quantities of these interesting compounds in complex matrices. (C) 1997 John Wiley & Sons, Ltd. RP Dalluge, JJ (reprint author), NIST,DIV ANALYT CHEM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. FU PHS HHS [Y1-7005-02] NR 17 TC 37 Z9 39 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 1997 VL 11 IS 16 BP 1753 EP 1756 DI 10.1002/(SICI)1097-0231(19971030)11:16<1753::AID-RCM92>3.0.CO;2-G PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA YE894 UT WOS:A1997YE89400003 PM 9375410 ER PT S AU DeWitt, DP Sorrell, FY Elliott, JK AF DeWitt, DP Sorrell, FY Elliott, JK BE Riley, TJ Gelpey, JC Roozeboom, F Saito, S TI Temperature measurement issues in rapid thermal processing SO RAPID THERMAL AND INTEGRATED PROCESSING VI SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Rapid Thermal and Integrated Processing VI, at the 1997 MRS Spring Meeting CY APR 01-04, 1997 CL SAN FRANCISCO, CA SP Mat Res Soc AB Reliable radiometric temperature measurement has been a major challenge in making rapid thermal processing (RTP) more widely accepted. In order to meet road map requirements involving temperature uncertainty, uniformity and control, new techniques must be demonstrated and/or existing measurement methods must be substantially improved. Critical aspects of radiometric methods for temperature measurement are centered about the topics: radiative and optical properties of the wafers including layered systems, surface roughness effects, and reflected irradiation from lamp banks and chamber walls. The systematic method for inferring temperature is rooted in the measurement equation which relates the radiometer output to the exitent spectral radiance from the target which reaches the detector and prescribes the roles that emissivity variability and stray radiation have on the result. An overview is provided on the knowledge base for optical and thermal radiative properties. Methods for reducing emissivity and stray radiation effects are summarized. Calibration procedures necessary to assure that the in-chamber or local temperature scale is traceable to the International Temperature Scale (ITS-90) are discussed. The issues which can impact improved temperature measurement practice are summarized. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP DeWitt, DP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 14 Z9 14 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-374-6 J9 MATER RES SOC SYMP P PY 1997 VL 470 BP 3 EP 15 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA BK42L UT WOS:000072112400001 ER PT B AU Veasey, DL Gary, JM Amin, J AF Veasey, DL Gary, JM Amin, J BE Honkanen, S TI Rigorous scalar modeling of Er and Er/Yb-doped waveguide lasers SO RARE-EARTH-DOPED DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Rare-Earth-Doped Devices CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE waveguide; laser; Q-switch; erbium; ytterbium; modeling; ion-exchange; sources AB A rigorous scalar model for predicting the characteristics of rare-earth-doped waveguide lasers has been developed. The model consists of two nonhomogeneous wave equations: one for the forward-propagating laser signal power, the other for the backward-propagating laser signal. These equations are coupled with one forward-propagating, nonhomogeneous wave equation representing the pump signal. The three wave equations are coupled with the space dependent laser rate equations to form a system of time dependent differential equations. This large system of equations is solved, using appropriate initial and boundary conditions, by the method of lines using collocation for the spatial approximation. The solutions to this system yield data which predict the time and position-dependent laser signal power, pump power, and population densities in a waveguide laser cavity supporting an arbitrary guided mode. The assumptions made in this new model are that the transverse field maintains the same shape as a function of longitudinal position in the laser cavity and that the effects of spatial hole burning and standing waves are neglected. We have used this model to predict continuous wave and Q-switched laser performance for Er and Er/Yb-doped lasers. We have achieved favorable comparisons with actual laboratory operation of cw Yb/Er-co-doped waveguide lasers. Results from simulations of Er-doped and Yb/Er-doped Q-switched lasers are presented which shaw that high peak powers on the order of 500 W and 1 ns pulse widths can be achieved. RP Veasey, DL (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2407-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 2996 BP 109 EP 120 DI 10.1117/12.271150 PG 12 WC Optics SC Optics GA BH79Y UT WOS:A1997BH79Y00014 ER PT B AU Amin, J Veasey, DL Sanford, NA Hayden, JS AF Amin, J Veasey, DL Sanford, NA Hayden, JS BE Honkanen, S TI Waveguide lasers by ion-exchange in Er-doped glass SO RARE-EARTH-DOPED DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Rare-Earth-Doped Devices CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE rare-earth-doped glass waveguide lasers; ion-exchanged devices AB Erbium and erbium/ytterbium co-doped silicate glass waveguide lasers have been fabricated by silver ion-exchange and their characteristics analyzed. We report on measurements and comparisons made in the lasing properties of these devices, including thresholds, slope-efficiencies and pump tuning ranges. The results presented show that through proper choice of host glass, it is possible to make low-threshold lasers both in singly and co-doped devices. RP Amin, J (reprint author), NATL INST STAND & TECHNOL,OPTOELECT MFG GRP,DIV 81504,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2407-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 2996 BP 135 EP 142 DI 10.1117/12.271152 PG 8 WC Optics SC Optics GA BH79Y UT WOS:A1997BH79Y00016 ER PT B AU Amin, J Aust, JA Sanford, NA AF Amin, J Aust, JA Sanford, NA BE Honkanen, S TI Stable CW operating waveguide lasers at room temperature in rare-earth-diffused lithium niobate SO RARE-EARTH-DOPED DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Rare-Earth-Doped Devices CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE rare-earth-doped waveguide lasers; lithium niobate active devices AB A means of reproducibly fabricating stable cw channel waveguide lasers in rare-earth-doped Ti:LiNbO3 is demonstrated, through careful choice of the light propagation direction. Z-propagating waveguides have been fabricated in Nd:Ti:LiNbO3 and room-temperature cw laser operation has been obtained by pumping in the 800 nm-band, with greatly reduced photorefractive instability. The reduced photorefractive damage susceptibility in this waveguide configuration has been used to our advantage in the realization, for the first time, of a 980 nm-pumped laser in Er:Ti:LiNbO3. The device showed a lasing threshold of 10.5 mW of absorbed pump power and a slope efficiency of 8.5%. RP Amin, J (reprint author), NATL INST STAND & TECHNOL,OPTOELECT MFG GRP,DIV 81504,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2407-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 2996 BP 166 EP 171 DI 10.1117/12.271156 PG 6 WC Optics SC Optics GA BH79Y UT WOS:A1997BH79Y00019 ER PT B AU Albritton, DL AF Albritton, DL BE Geshwiler, M TI Ozone depletion and global warming SO REFRIGERANTS FOR THE 21ST CENTURY LA English DT Proceedings Paper CT ASHRAE/NIST Refrigerants Conference on Refrigerants for the 21st-Century CY OCT 06-07, 1997 CL GAITHERSBURG, MD SP Amer Soc Heating Refrigerat & Air Condit Engineers Inc, Natl Inst Stand & Technol, US DOE, Int Inst Ammonia Refrigerat, Int Inst Refrigerat, Air Condit & Refrigerat Inst, Univ Purdue, Ray W Herrick Labs AB Over the past thirty years, the scientific and political communities have faced two geophysical phenomena that are global in, scale: ozone depletion and climate change. This paper will provide a status report on the current scientific understanding of these two issues, with special emphasis on how science can help with the decision-related information needs of governments and industry during the coming years. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Albritton, DL (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA BN 1-883413-47-8 PY 1997 BP 1 EP 5 PG 5 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BP18J UT WOS:000084340000001 ER PT B AU McLinden, MO Lemmon, EW Jacobsen, RT AF McLinden, MO Lemmon, EW Jacobsen, RT BE Geshwiler, M TI Thermodynamic properties for the alternative refrigerants SO REFRIGERANTS FOR THE 21ST CENTURY LA English DT Proceedings Paper CT ASHRAE/NIST Refrigerants Conference on Refrigerants for the 21st-Century CY OCT 06-07, 1997 CL GAITHERSBURG, MD SP Amer Soc Heating Refrigerat & Air Condit Engineers Inc, Natl Inst Stand & Technol, US DOE, Int Inst Ammonia Refrigerat, Int Inst Refrigerat, Air Condit & Refrigerat Inst, Univ Purdue, Ray W Herrick Labs ID VAPOR-LIQUID-EQUILIBRIUM; PLUS PENTAFLUOROETHANE R-32+125; PVTX PROPERTIES; NORMAL-BUTANE; PHASE PROPERTIES; MIXTURES; EQUATION; SYSTEM; STATE; DENSITIES AB Models commonly used to calculate the thermodynamic properties of refrigerants are summarized. For pure refrigerants, the virial, cubic, Martin-Hou, Benedict-Webb-Rubin, and Helmholtz energy equations of state and the extended corresponding states model are discussed. High-accuracy formulations for 16 refrigerants are recommended. These models may be extended to mixtures through the use of mixing rules applied either to the parameters of the equation of state or to some property of the mixture components. Mixtures of a specific composition may also be modeled as a pseudo-pure fluid. Five mixture models, employing four distinct approaches, have been compared by a group working under the auspices of the International Energy Agency. These comparisons show all five models to pie very capable in representing mixture properties. No single model was best in all aspects, but based on its combination of excellent accuracy and great generality, we recommend the mixture Helmholtz energy model as the best available. Experimental data are essential both to fit the adjustable parameters in property models and to assess their accuracy. We present a survey of the data available for mixtures of the HFC refrigerants R-32, R-125, R-143a, R-134a, and R-152a and for mixtures of the natural refrigerants propane, butane, isobutane, and carbon dioxide. More than 60 data references are identified. Further data needs include caloric data for additional mixtures, comprehensive pressure-density-temperature data for additional mixture compositions, and improved accuracy for vapor-liquid equilibria data. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO USA. RP McLinden, MO (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO USA. NR 101 TC 0 Z9 0 U1 1 U2 3 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA BN 1-883413-47-8 PY 1997 BP 135 EP 154 PG 20 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BP18J UT WOS:000084340000016 ER PT J AU Gupta, SK Regli, WC Das, D Nau, DS AF Gupta, SK Regli, WC Das, D Nau, DS TI Automated manufacturability analysis: A survey SO RESEARCH IN ENGINEERING DESIGN-THEORY APPLICATIONS AND CONCURRENT ENGINEERING LA English DT Review DE CAD; concurrent engineering; design for manufacturing ID FEATURE RECOGNITION; CONVEX DECOMPOSITION; PRODUCT DESIGN; BOUNDARY REPRESENTATIONS; DISCRETE COMPONENTS; MACHINING FEATURES; COMBINED CRITERION; FIXTURE DESIGN; SOLID MODELS; SYSTEM AB In the market-place of the 21st century, there is no place for traditional 'over-the-wall' communications between design and manufacturing. In order to 'design it right the very first time', designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems ave emerging as one such tool - enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them. In this paper, we provide a survey of current state-of-the-art automated manufacturability analysis. We present the historical context in which this area has emerged and outline characteristics to compare and classify various systems. We describe the two dominant approaches to automated manufacturability analysis and overview representative systems based on their application domain. We describe support tools that enhance the effectiveness of manufacturability analysis systems. Finally, we attempt to expose some of the existing research challenges and future directions. C1 NATL INST STAND & TECHNOL,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,DEPT COMP SCI,INST ADV COMP STUDIES,COLLEGE PK,MD 20742. UNIV MARYLAND,SYST RES INST,COLLEGE PK,MD 20742. RP Gupta, SK (reprint author), CARNEGIE MELLON UNIV,INST ROBOT,CTR INTEGRATED MFG DECIS SYST,PITTSBURGH,PA 15213, USA. NR 180 TC 71 Z9 72 U1 0 U2 8 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL ROAD, GODALMING, SURREY, ENGLAND GU7 3DJ SN 0934-9839 J9 RES ENG DES JI Res. Eng. Design-Theory Appl. Concurrent Eng. PY 1997 VL 9 IS 3 BP 168 EP 190 DI 10.1007/BF01596601 PG 23 WC Engineering, Multidisciplinary; Engineering, Industrial; Engineering, Manufacturing SC Engineering GA XV809 UT WOS:A1997XV80900003 ER PT S AU Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ OBrian, TR Rolston, SL Vansteenkiste, N AF Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ OBrian, TR Rolston, SL Vansteenkiste, N BE Winograd, N Parks, JE TI Doppler-free resonance ionization spectroscopy of the He 1s(2) S-1-1s2s S-1 transition at 120.3 nm SO RESONANCE IONIZATION SPECTROSCOPY 1996 - EIGHTH INTERNATIONAL SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Symposium on Resonance Ionization Spectroscopy and Its Applications CY JUN 30-JUL 05, 1996 CL STATE COLL, PA SP US DOE, Off Hlth & Environm Res, Natl Sci Fdn, Penn State Univ, Univ Tennessee, Clark MXR Inc, Phys Electr Inc, Posit Light AB An accurate determination of the Lamb shift in the ground state of He is a sensitive check of QED calculations in the 2-electron, 3-body regime. We have begun an experiment that should determine the Lamb shift in the ground state of He with an accuracy better than the uncertainty in the best QED calculations. The measurement will employ a 2-photon Doppler-free resonant excitation of the He 1s(2 1)S -> 1s2s S-1 transition at 120.3 nm, followed by ionization of the 1s2s S-1 state. RP Bergeson, SD (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-611-5 J9 AIP CONF PROC PY 1997 IS 388 BP 109 EP 112 DI 10.1063/1.52157 PG 4 WC Spectroscopy SC Spectroscopy GA BH29A UT WOS:A1997BH29A00016 ER PT S AU McPherron, RL Nakamura, R Kokubun, S Kamide, Y Shiokawa, K Yumoto, K Mukai, T Saito, Y Hayashi, K Nagai, T Ables, S Baker, DN FriisChristensen, E Fraser, B Hughes, T Reeves, G Singer, H AF McPherron, RL Nakamura, R Kokubun, S Kamide, Y Shiokawa, K Yumoto, K Mukai, T Saito, Y Hayashi, K Nagai, T Ables, S Baker, DN FriisChristensen, E Fraser, B Hughes, T Reeves, G Singer, H BE Russell, CT TI Fields and flows at geotail during a moderate substorm SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID MAGNETOSPHERIC SUBSTORMS; PI2 PULSATIONS; NEUTRAL LINE; MAGNETOTAIL; MODEL AB The behavior of the tail field and plasma during a moderate substorm with onset at similar to 1120 UT on Dec. 13, 1994 is examined using data from the ISTP spacecraft GEOTAIL and WIND, synchronous orbit and the ground. Five substorms were observed on this day while GEOTAIL was located near the center of the tail at Xgsm = -46 R-e. In each substorm the field and plasma variations were similar to those observed during substorms by spacecraft closer to the earth. A southward turning of the IMF caused accumulation of lobe flux, development of a more tail-like field, and eventually an expansion phase and its consequences. The similar to 1120 UT onset immediately followed a northward turning which ended a lengthy interval in which the IMF was alternately northward and southward. Shortly after the onset a flux rope passed GEOTAIL with a delay consistent with its formation at 20-30 Re several minutes earlier than a Pi 2 burst began at midnight. Immediately after the onset the lobe field decreased and the plasma sheet disappeared. During the substorm recovery phase the plasma sheet reappeared with plasma moving earthward. The plasma data show that the tailward flow is a combination of convecting and streaming plasma. All of the substorms exhibited multiple onsets. The main onset of each can be determined by a combination of negative bay onsets, Pi 2 bursts, synchronous field-aligned currents, dispersionless particle injection, and midlatitude positive bays. In one event the flux rope at 46 R-e arrived before dispersionless injection at synchronous orbit suggesting that reconnection in the tail begins at or before major onsets. In fact most of the major onsets were preceded by pseudo breakups early in the growth phase, and weak tailward flows carrying a weak vertical field fluctuating about zero. These observations suggest that reconnection begins in the middle tail early in the growth phase and that it is substantially intensified or begins again at another location at the expansion onset. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NAGOYA UNIV, SOLAR TERR ENVIRONM LAB, TOYOKAWA 446, JAPAN. INST SPACE & ASTRONAUT SCI, SAGAMIHARA, KANAGAWA 229, JAPAN. UNIV TOKYO, DEPT EARTH & PLANETARY PHYS, TOKYO, JAPAN. TOKYO INST TECHNOL, DEPT EARTH & PLANETARY SCI, MEGURO KU, TOKYO 152, JAPAN. UNIV NEWCASTLE, DEPT PHYS, NEWCASTLE, NSW 2308, AUSTRALIA. UNIV COLORADO, ATMOSPHER & SPACE PHYS LAB, BOULDER, CO 80309 USA. NATL RES COUNCIL CANADA, HERZBERG INST ASTROPHYS, SOLAR TERR PHYS SECT, OTTAWA, ON K1A 0R6, CANADA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NOAA, ERL, RESE SPACE ENVIRONM LAB, BOULDER, CO 80303 USA. DANISH METEOROL INST, DK-15470 COPENHAGEN, DENMARK. RP McPherron, RL (reprint author), UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90095 USA. RI Nakamura, Rumi/I-7712-2013; Reeves, Geoffrey/E-8101-2011 OI Nakamura, Rumi/0000-0002-2620-9211; Reeves, Geoffrey/0000-0002-7985-8098 NR 12 TC 1 Z9 1 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 923 EP 931 DI 10.1016/S0273-1177(97)00500-0 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00046 ER PT B AU Manley, MG Hsu, NN AF Manley, MG Hsu, NN BE Thompson, DO Chimenti, DE TI Response of a focused transducer facing a rigid reflector SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Manley, MG (reprint author), NATL INST STAND & TECHNOL,AUTOMATED PROD TECHNOL DIV,BLDG 233,ROOM A-147,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 869 EP 875 PN A&B PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00113 ER PT B AU Hollman, KW Fortunko, CM Fitting, DW AF Hollman, KW Fortunko, CM Fitting, DW BE Thompson, DO Chimenti, DE TI Through-thickness elastic constant for aramid-epoxy/aluminum composite materials SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Hollman, KW (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 1115 EP 1122 PN A&B PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00145 ER PT B AU Hurley, DC Yost, WT Boltz, ES Fortunko, CM AF Hurley, DC Yost, WT Boltz, ES Fortunko, CM BE Thompson, DO Chimenti, DE TI A comparison of three techniques to determine the nonlinear ultrasonic parameter beta SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Hurley, DC (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,MAIL CODE 853-000,BOULDER,CO 80303, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 1383 EP 1390 PN A&B PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00180 ER PT B AU Xiang, D Hsu, NN Blessing, GV AF Xiang, D Hsu, NN Blessing, GV BE Thompson, DO Chimenti, DE TI Ultrasonic evaluation of rough and porous ceramic coatings with a dual-element large aperture lensless line-focus transducer SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Xiang, D (reprint author), NIST,ULTRASON GRP,AUTOMATED PROD TECHNOL DIV,BTE 270 & QUINCE ORCHARD BLVD,BLDG 233,RM A-147,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 1563 EP 1570 PN A&B PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00204 ER PT J AU Johnson, W Alers, GA AF Johnson, W Alers, GA TI Force measurement using vibrational spectroscopy SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The stress dependence of ultrasonic velocities is used as the physical basis for a device that measures large forces. A solid aluminum cylinder serves as a load-bearing element, and noncontacting electromagnetic-acoustic transducers are used to excite and detect resonant vibrational modes; The problem of vibrational damping at the ends of the cylinder is solved by making the diameter slightly larger in a central section, so that certain resonant modes are ''trapped,'' with negligible amplitude al the ends. Nearly complete temperature compensation is achieved by taking the ratio of two resonant frequencies with approximately the same temperature dependence but with much different stress dependencies. The measurement of force with vibrational spectroscopy provides several advantages over conventional resistive strain gages, including greater resolution, insensitivity to transducer and bond degradation, durability in harsh environments, and insensitivity to bending moments. The resolution in strain is approximately 4 x 10(-8). The upper limit of measurable stresses approaches the yield strength of the aluminum cylinder; this is approximately 325 MPa, which corresponds to a strain of 4 x 10(-3). RP Johnson, W (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 11 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 1997 VL 68 IS 1 BP 102 EP 108 DI 10.1063/1.1147779 PN 1 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WD236 UT WOS:A1997WD23600019 ER PT J AU Band, A Unguris, J AF Band, A Unguris, J TI Optically isolated current-to-voltage converter for an electron optics system SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A simple, inexpensive, optically isolated current-to-voltage converter circuit has been developed for the measurement of bipolar currents in the range of 10 pA-1 mu A On the biased elements of an electron optics system at voltages up to 3.5 kV. The design takes advantage of low-leakage, low-power complementary metal-oxide semiconductor operational amplifiers as well as Linear optocouplers to create a low-noise battery-powered front end with an expected battery life of three years using a single 9 V lithium battery. RP Band, A (reprint author), NIST,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Unguris, John/J-3989-2014 NR 1 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 1997 VL 68 IS 1 BP 250 EP 251 DI 10.1063/1.1147738 PN 1 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WD236 UT WOS:A1997WD23600047 ER PT J AU Regan, SP May, MJ Soukhanovskii, V Finkenthal, M Moos, HW Farnum, EH Clinard, FW Tarrio, C Watts, R AF Regan, SP May, MJ Soukhanovskii, V Finkenthal, M Moos, HW Farnum, EH Clinard, FW Tarrio, C Watts, R TI An evaluation of multilayer mirrors for the soft x ray and extreme ultraviolet wavelength range that were irradiated with neutrons SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 11th Topical Conference on High-Temperature Plasma Diagnostics CY MAY 12-16, 1996 CL MONTEREY, CA SP Amer Phys Soc, US DOE, Off Fus Energy, Lawrence Livermore Natl Lab ID TUNGSTEN-CARBON; THERMAL-STABILITY; TOKAMAK PLASMA; POLYCHROMATOR; RADIATION; MO/SI; W/C AB The Plasma Spectroscopy Group at the Johns Hopkins University develops high photon throughput multilayer mirror (MLM) based soft x ray and extreme ultraviolet (XUV 10 Angstrom3.0.CO;2-2 PG 11 WC Chemistry, Physical SC Chemistry GA WF203 UT WOS:A1997WF20300005 ER PT S AU Croley, TE AF Croley, TE BE Rosbjerg, D Boutayeb, NE Gustard, A Kundzewicz, ZW TI Water resource predictions from meteorological probability forecasts SO SUSTAINABILITY OF WATER RESOURCES UNDER INCREASING UNCERTAINTY SE IAHS PUBLICATION LA English DT Proceedings Paper CT International Symposium on Sustainability of Water Resources Under Increasing Uncertainty, at the 5th Scientific Assembly of IAHS CY APR 23-MAY 03, 1997 CL RABAT, MOROCCO SP Int Assoc Hydrol Sci, Int Comm Water Resources syst, Int Assoc Hydrol Sci, Int Comm Surface Water, Int Assoc Hydrol Sci, Int Comm Groundwater, UNESCO, World Meteorol Org, Moroccan Water Resources Assoc AB NOAA recently began providing monthly seasonal climate outlooks of expected air temperature and precipitation probabilities. Users can interpret climate outlooks to assess the risk to water resources of extreme meteorological conditions and of variability in general. One important approach uses historical meteorology record segments with hydrological, limnological and other models to simulate hydrological possibilities for the future (preserving observed spatial and temporal relationships). The meteorological possibilities are weighted to be compatible with climate outlook probabilities. The corresponding weighted hydrological possibilities are used to infer water resource probabilities and other parameters. The weights are determined by constructing boundary equations for the weights to match climate outlooks, setting the relative importance of each equation in case incompatibilities arise and solving them for physically relevant values. Their solution becomes an optimization problem for the general case. An example illustrates the concepts and method. RP Croley, TE (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 1-901502-05-8 J9 IAHS-AISH P PY 1997 IS 240 BP 301 EP 309 PG 9 WC Water Resources SC Water Resources GA BJ32E UT WOS:A1997BJ32E00033 ER PT J AU Greene, JS Morrissey, ML Ferraro, RR AF Greene, JS Morrissey, ML Ferraro, RR TI Verification of a scattering-based algorithm for estimating rainfall over the open ocean SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article ID PROBABILITY-DISTRIBUTION FUNCTIONS; SENSOR MICROWAVE IMAGER; SATELLITE; PRECIPITATION; RETRIEVAL; ERRORS AB An algorithm for estimating rainfall (based upon scattering of upwelling radiation at 85 GHz) using the Special Sensor Microwave Imager (SSM/I) 85 GHz sensor data has recently been developed at the National Oceanographic and Atmospheric Administration's Office of Research and Applications (NOAA ORA). Spatial and temporal variability in the differences between simple areal-averaged rainfall estimates from a raingage and satellite-derived estimates are examined. These initial comparisons provide insight into the nature of the differences, however, due to substantial amounts of spatial sampling error in the raingage spatial averages, this approach is ineffective at identifying statistically significant differences. Thus, rainfall estimates for this algorithm are examined over the tropical Pacific using a statistical technique, called the ''noncontiguous raingage method'' (NCR), which minimizes spatial sampling error so that the statistical significance of relationships may be determined. The results indicate that, adjusted with calibration coefficients, the ORA algorithm could produce unbiased estimates of areal rainfall for the tropical Pacific region examined in this study. C1 NOAA,OFF RES & APPLICAT,CAMP SPRINGS,MD 20746. UNIV OKLAHOMA,ENVIRONM VERIFICAT & ANAL CTR,NORMAN,OK 73019. RP Greene, JS (reprint author), UNIV OKLAHOMA,OKLAHOMA CLIMATE SURVEY,NORMAN,OK 73019, USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 30 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-798X J9 THEOR APPL CLIMATOL JI Theor. Appl. Climatol. PY 1997 VL 56 IS 1-2 BP 33 EP 44 DI 10.1007/BF00863781 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD060 UT WOS:A1997WD06000003 ER PT S AU DiMeo, F Cavicchi, RE Semancik, S Suehle, JS Tea, NH Kelliher, JT AF DiMeo, F Cavicchi, RE Semancik, S Suehle, JS Tea, NH Kelliher, JT BE Moss, SC Ila, D Cammarata, RC Chason, EH Einstein, TL Williams, ED TI Observation of film growth phenomena using micromachined structures SO THIN FILMS - STRUCTURE AND MORPHOLOGY SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thin Films - Structure and Morphology CY DEC 01-06, 1996 CL BOSTON, MA SP Mat Res Soc AB A method of studying thin film growth and materials processing using micromachined Si-based structures is presented. The microsubstrate platforms (called ''micropotplates'') allow temperature control during deposition, and in situ monitoring of the electrical properties of connected coatings. The efficiency of the approach is amplified when multiple, independently operated elements are used in array configurations. Illustrations here involve chemical vapor deposition of semiconducting oxides, but the methodology can be employed to investigate the growth of other classes of materials as well. RP DiMeo, F (reprint author), NIST,PROC MEASUREMENTS DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-345-2 J9 MATER RES SOC SYMP P PY 1997 VL 441 BP 69 EP 74 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA BJ39K UT WOS:A1997BJ39K00012 ER PT S AU Knopp, KJ Ketterl, JR Christensen, DH Pearsall, TP Hill, JR AF Knopp, KJ Ketterl, JR Christensen, DH Pearsall, TP Hill, JR BE Moss, SC Ila, D Cammarata, RC Chason, EH Einstein, TL Williams, ED TI Simultaneous monitoring of wafer- and environment-states during molecular beam epitaxy SO THIN FILMS - STRUCTURE AND MORPHOLOGY SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thin Films - Structure and Morphology CY DEC 01-06, 1996 CL BOSTON, MA SP Mat Res Soc AB We report the simultaneous monitoring of the environment-state and wafer-state during epitaxial crystal growth using a single real-time measurement. Atomic absorption spectroscopy (AAS) is used to monitor the incident molecular beam flux while UV reflectance (UVR) at 396 nm with an incident angle of 78 degrees is used to monitor growth on the wafer. We have studied the utility of AAS/UVR monitoring of AlxGa1-xAs deposition: AlAs growing on GaAs, GaAs on AlAs, and superlattice growth. Additionally, optical multichannel spectroscopy (OMS) data were acquired throughout the growth of a distributed Bragg reflector (DBR). The relationship of the structure of the real-time OMS data to absorption, optical path length variation, and differential layer thickness variations is also discussed. Numerical simulations of the real-time wafer-state monitors using pseudodielectric constants, appropriate at a growth temperature of 579 degrees C, show good agreement with measured spectra. RP Knopp, KJ (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-345-2 J9 MATER RES SOC SYMP P PY 1997 VL 441 BP 761 EP 766 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA BJ39K UT WOS:A1997BJ39K00121 ER PT S AU Clemente-Colon, P Pichel, W Yan, XH AF Clemente-Colon, P Pichel, W Yan, XH GP ESA TI Evolution of oil slick patterns as observed by SAR off the coast of Wales SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOL 1 SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB Imagery from three different Synthetic Aperture Radar (SAR) spaceborne sensors were obtained over the coast of Wales, UK. These observations indicated the persistence of slick features associated with the grounding on February 15, 1996 of the Sea Empress tanker at the entrance of the Milford Haven estuary and the resulting massive oil spill that followed. RADARSAT, ERS-1, and ERS-2 SAR images revealed the evolution of these features from February 22 to February 26, 1996, The feature tracking Maximum Similarity Shape Matching method (MSSM) developed at the University of Delaware College of Marine Studies (CMS) was applied to the pair of ERS SAR images. MSSM calculated drift speeds of about 10 cm/s. Observations of the slick pattern evolution in the SAR imagery were compared to available reports of ground conditions. Deformation of the slick features was also evident in the SAR data throughout the five-day period. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. RP Clemente-Colon, P (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 0 TC 0 Z9 0 U1 0 U2 2 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 565 EP 568 PG 4 WC Environmental Sciences; Geosciences, Multidisciplinary; Remote Sensing SC Environmental Sciences & Ecology; Geology; Remote Sensing GA BK74Q UT WOS:000073315300097 ER PT S AU Lillibridge, J Leben, R Vossepoel, F AF Lillibridge, J Leben, R Vossepoel, F GP ESA TI Real time altimetry from ERS-2 SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy DE operational altimetry; mesoscale oceanography; western boundary currents AB Since November 1995, NOAA has been generating "Real-time Geophysical Data Records" (RGDRs) for ERS-1 and ERS-2. ESA's Fast-Delivery altimeter data arrive at NOAA within 6 hours of acquisition, are combined with JGM-3 orbits produced by the Delft Univ. of Technology, and are enhanced with several environmental corrections. The operationally computed orbits are generated with a 2-3 day lag. To create RGDRs within 12 hours of acquisition, we use a predicted orbit extension to each orbital solution. The RGDRs contain orbit errors of similar to 50 cm, so are most useful for short-are mesoscale studies. Results from two such applications are presented: monitoring of the Gulf Stream region and the Gulf of Mexico Loop Current. A refined data set, the "Interim Geophysical Data Records" (IGDRs), can be computed within 3 days using the most precise part of the Delft orbits. These data have orbit errors of similar to 10 cm, and are suitable for large-scale interannual monitoring. The IGDR data will soon be assimilated into a coupled ocean/atmosphere model running at NOAA, as is currently being done with near real-time TOPEX altimetry. C1 NOAA, Lab Satellite Altimetry, Silver Spring, MD 20910 USA. Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. Delft Univ Technol, Delft Inst Earth Oriented Space Res, NL-2629 HS Delft, Netherlands. RP Lillibridge, J (reprint author), NOAA, Lab Satellite Altimetry, 1305 EW Highway, Silver Spring, MD 20910 USA. RI Lillibridge, John/F-5606-2010 OI Lillibridge, John/0000-0001-9102-171X NR 0 TC 2 Z9 2 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 1449 EP 1454 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900152 ER PT B AU Greenberg, RR AF Greenberg, RR BE Fischer, PWF Labbe, MR Cockell, KA Gibson, RS TI Unique quality assurance aspects of neutron activation analysis SO TRACE ELEMENTS IN MAN AND ANIMALS - 9 LA English DT Proceedings Paper CT 9th International Symposium on Trace Elements in Man and Animals (TEMA 9) CY MAY 19-24, 1996 CL BANFF, CANADA SP Int Lead Zinc Res Org Inc, Int Cooper Assoc Ltd, Kellogg Canada Inc, MRC Canada, Nestec SA, Procter & Gamble Co, Ross Labs, Div Abbott Labs Ltd, US Pharmocopeial Convent Inc, Wyeth Ayerst Res, Zinpro Corp DE neutron activation analysis; quality assurance; standard reference materials; certification C1 NIST, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Greenberg, RR (reprint author), NIST, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA BUILDING M-55, OTTAWA, ON KIA OR6, CANADA BN 0-660-16404-3 PY 1997 BP 410 EP 413 PG 4 WC Agriculture, Dairy & Animal Science; Environmental Sciences; Food Science & Technology; Public, Environmental & Occupational Health; Nutrition & Dietetics; Zoology SC Agriculture; Environmental Sciences & Ecology; Food Science & Technology; Public, Environmental & Occupational Health; Nutrition & Dietetics; Zoology GA BK57Z UT WOS:000072613500151 ER PT S AU Ramsay, BH AF Ramsay, BH GP CANADIAN GEOPHYS UNION CANADIAN GEOPHYS UNION CANADIAN GEOPHYS UNION TI The Interactive Multisensor Snow and Ice Mapping System SO WESTERN SNOW CONFERENCE, 65TH ANNUAL MEETING SE PROCEEDINGS OF THE WESTERN SNOW CONFERENCE (SERIES) LA English DT Proceedings Paper CT Sessions on Hydrology and Snow, at 65th Annual Western Snow Conference / 54th Annual Eastern Snow Conference / 23rd Annual Meeting of the Canadian-Geophysical-Union CY MAY 04-08, 1997 CL BANFF, CANADA SP Canadian Geophys Union, Hydrol Sect, E Snow Conf, W Snow Conf AB The Interactive Multisensor Snow and Ice Mapping System (IMS) was developed to give snow and ice analysts the tools, on one platform, to visually inspect 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 89x89 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, timely product. C1 NOAA, NESDIS, Sci Ctr, Camp Springs, MD 20746 USA. RP Ramsay, BH (reprint author), NOAA, NESDIS, Sci Ctr, Room 510,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WESTERN SNOW CONFERENCE PI PORTLAND PA PO BOX 2646, PORTLAND, OR 97208 USA SN 0161-0589 J9 P WEST SNOW CONF PY 1997 BP 198 EP 209 PG 12 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA BK24L UT WOS:000071608400020 ER PT S AU Cline, D Elder, K Bales, R AF Cline, D Elder, K Bales, R GP CANADIAN GEOPHYS UNION CANADIAN GEOPHYS UNION CANADIAN GEOPHYS UNION TI Scale effects in a distributed SWE and snowmelt model for mountain basins SO WESTERN SNOW CONFERENCE, 65TH ANNUAL MEETING SE PROCEEDINGS OF THE WESTERN SNOW CONFERENCE (SERIES) LA English DT Proceedings Paper CT Sessions on Hydrology and Snow, at 65th Annual Western Snow Conference / 54th Annual Eastern Snow Conference / 23rd Annual Meeting of the Canadian-Geophysical-Union CY MAY 04-08, 1997 CL BANFF, CANADA SP Canadian Geophys Union, Hydrol Sect, E Snow Conf, W Snow Conf AB We present results of an investigation into the effect of increasing spatial and temporal resolutions on modeled distributions of SWE and snowmelt in the Emerald Lake Watershed of the Sierra Nevada of California, U.S.A. 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 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 snowcover. Similarly, we degraded the temporal resolution of the micrometeorological data from 1 hour to 3 and 6 hours 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 to 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 over-estimated 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. C1 NOAA, Natl Weather Serv, Off Hydrol, Natl Operat Hydrol Remote Sensing Ctr, Silver Spring, MD 20910 USA. RP Cline, D (reprint author), NOAA, Natl Weather Serv, Off Hydrol, Natl Operat Hydrol Remote Sensing Ctr, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WESTERN SNOW CONFERENCE PI PORTLAND PA PO BOX 2646, PORTLAND, OR 97208 USA SN 0161-0589 J9 P WEST SNOW CONF PY 1997 BP 317 EP 328 PG 12 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA BK24L UT WOS:000071608400032 ER PT B AU Black, D Polvani, R Braun, L Hockey, B White, G AF Black, D Polvani, R Braun, L Hockey, B White, G BE Tustison, RW TI Detection of sub-surface damage: studies in sapphire SO WINDOW AND DOME TECHNOLOGIES AND MATERIALS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Window and Dome Technologies and Applications CY APR 21-22, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE surface damage; sub-surface damage; sapphire; x-ray topography; Raman spectroscopy; transmission electron microscopy AB A variety of nondestructive characterization techniques has been used to detect and measure subsurface damage in single-crystal sapphire to develop methods suitable to inspect high performance optics for sub-surface damage, These techniques include polarized Light microscopy, x-ray diffraction topography, transmission electron microscopy (TEM) and Raman spectroscopy. TEM examination shows that for ground surfaces damage can extend up to 6-7 mu m into the bull: and includes cracks, twins and dislocations, while under polished surfaces only dislocations are seen. X-ray diffraction topography can image defects such as long-range strain, dislocations, residual surface scratches (not visible optically) and low-angle grain boundaries (lineage). Polarized light is also sensitive to strain and provides a relatively easy method for detecting defects such as cracks and Lineage. Of all of the techniques Raman spectroscopy offers the best potential for quantifying strain in terms of stress. RP Black, D (reprint author), NATL INST STAND & TECHNOL,223-A163,GAITHERSBURG,MD 20899, USA. NR 0 TC 14 Z9 14 U1 0 U2 4 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2475-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3060 BP 102 EP 114 DI 10.1117/12.277036 PG 13 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BJ21Y UT WOS:A1997BJ21Y00010 ER PT J AU Jolie, J Stritt, N Borner, HG Doll, C Jentschel, M Robinson, SJ Kessler, EG AF Jolie, J Stritt, N Borner, HG Doll, C Jentschel, M Robinson, SJ Kessler, EG TI The neutrino induced Doppler broadening technique and its application to the study of phonon creation in solids SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article ID GAMMA-SPECTROSCOPY; SIMULATION; LIFETIMES AB Phonons in solids are studied experimentally by observing the motion of an atom which is at the origin of a lattice vibration. The atom is given an excess kinetic energy of 3 eV via the emission of an electron neutrino in a nuclear reaction. Its motion is observed by measuring the Doppler shift of subsequently emitted gamma-rays using ultra-high resolving power spectroscopy. In this way the motion of the atom during the first hundred of femtoseconds can be investigated. The results of the experiment are analysed using the Debye approximation and compared to a Molecular Dynamics simulation. C1 INST MAX VON LAUE PAUL LANGEVIN, F-38042 GRENOBLE, FRANCE. TENNESSEE TECHNOL UNIV, DEPT PHYS, COOKEVILLE, TN 38505 USA. NATL INST STAND & TECHNOL, ATOM PHYS DIV, GAITHERSBURG, MD 20899 USA. RP Jolie, J (reprint author), UNIV FRIBOURG, INST PHYS, PEROLLES, CH-1700 FRIBOURG, SWITZERLAND. NR 18 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-3277 J9 Z PHYS B CON MAT JI Z. Phys. B-Condens. Mat. PD JAN PY 1997 VL 102 IS 1 BP 1 EP 7 PG 7 WC Physics, Condensed Matter SC Physics GA WE191 UT WOS:A1997WE19100003 ER PT J AU Levin, BC AF Levin, BC TI New research avenues in toxicology: 7-gas N-Gas model, toxicant suppressants, and genetic toxicology SO TOXICOLOGY LA English DT Article; Proceedings Paper CT International Colloquium on Advances in Combustion Toxicology CY APR 11-13, 1995 CL OKLAHOMA CITY, OK SP CAMI, FAA DE combustion gases; N-Gas Model; toxicant suppressants; genetic toxicology; polyurethane foam ID NITROGEN; TOXICITY; PRODUCTS; EXPOSURE; DIOXIDE; DAMAGE; SMOKE AB Three research areas - a 7-gas N-Gas Model, toxicant suppressants, and genetic toxicology - are presented as new research approaches in toxicology. The current 6-gas N-Gas Model predicts the toxic potency of the combustion products of materials based on the toxicological interactions of the fire gases carbon monoxide (GO), carbon dioxide (CO2), low oxygen (O-2) concentrations, hydrogen cyanide (HCN), hydrogen chloride, and hydrogen bromide. The present research includes nitrogen dioxide (NO2) in a new 7-gas model which incorporates the synergistic effects of NO2 and CO2, the antagonistic effects of NO2 and HCN, and the additive effects of NO2 with CO and low O-2. The area of toxicant suppressants concerns chemicals, which when added to a material, will inhibit or reduce the concentration of a specific toxic gas normally generated during thermal decomposition of that material. The effectiveness of this approach was demonstrated at the US National Institute of Standards and Technology when HCN generation was reduced by 90% and the resultant toxicity of the combustion products was lowered by 50% when a flexible polyurethane (FPU) foam was treated with 0.1% (by weight) cuprous oxide (Cu2O). Although melamine-treated FPU foams are being promoted as more fire safe than standard foams, a melamine-treated foam generated 10 times more HCN than a foam without melamine. The addition of Cu2O to this melamine foam also reduced the HCN generation by 90%. The genetic toxicology research entails the examination of DNA damage that results from the exposure of human cells to various environmental toxicants and gases. RP Levin, BC (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 41 TC 22 Z9 26 U1 3 U2 9 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD DEC 31 PY 1996 VL 115 IS 1-3 BP 89 EP 106 DI 10.1016/S0300-483X(96)03497-X PG 18 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA WE804 UT WOS:A1996WE80400009 PM 9016743 ER PT J AU Olivier, BJ Lagasse, RR Schaefer, DW Barnes, JD Long, GG AF Olivier, BJ Lagasse, RR Schaefer, DW Barnes, JD Long, GG TI A small-angle-scattering study of the pore-orientation periodicity in porous polymer and carbon materials SO MACROMOLECULES LA English DT Article ID SPHERULITES; CAMERA AB Absolute-intensity, small-angle X-ray scattering is used to investigate the pore structure of a carbon foam and its corresponding poly(acrylonitrile) foam precursor, both having a concentric band structure of unusually large spacing. The poly(acrylonitrile) foam was prepared from a solidified blend, containing crystallized maleic anhydride, by subliming the crystalline material. The scattering patterns for both foams reveal anisotropy in their pores and identical periodicity in the pore orientation as a function of distance along the radial direction. The period of pore-orientation oscillations, 3.5 mm, is the same as the period of macroscopically-visible bands present on the surface of both the carbon and poly(acrylonitrile) foams. Furthermore, the pore orientations in both samples show the same oscillatory orientation as the maleic anhydride crystals of the blend from which they were derived. The data suggest that a spherulitic orientation of the maleic anhydride crystals in the blend was imprinted on the polymer phase during crystallization. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. OKLAHOMA STATE UNIV,DEPT PHYS,STILLWATER,OK 74078. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 16 TC 8 Z9 8 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 30 PY 1996 VL 29 IS 27 BP 8615 EP 8621 DI 10.1021/ma9508111 PG 7 WC Polymer Science SC Polymer Science GA WB741 UT WOS:A1996WB74100008 ER PT J AU Rudmin, JD Ratliff, LP Yukich, JN Larson, DJ AF Rudmin, JD Ratliff, LP Yukich, JN Larson, DJ TI Structure of the photodetachment cross section in a magnetic field: An experiment with OH- SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID LASER-PHOTODETACHMENT; THRESHOLD PHOTODETACHMENT; NEGATIVE-IONS; SPECTROSCOPY; PARALLEL; SEH; OD AB Photodetachment from OH- in a magnetic field has been studied experimentally using light with energies between 14 400 and 14 900 cm(-1). Presented here are high-resolution data which exhibit sharp magnetic field structure at thresholds and low-resolution data which show monotonically increasing cross sections. The current work is the first in any atomic or molecular system where sufficient energy resolution has been achieved to observe the shape of the cross section in a magnetic field. C1 NIST,ATOM PHYS DIV,GAITHERSBURG,MD 20899. UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109. RP Rudmin, JD (reprint author), UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22903, USA. NR 32 TC 7 Z9 7 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD DEC 28 PY 1996 VL 29 IS 24 BP L881 EP L888 DI 10.1088/0953-4075/29/24/004 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WB226 UT WOS:A1996WB22600004 ER PT J AU Wang, XL Rui, HL AF Wang, XL Rui, HL TI A methodology for assessing ensemble experiments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RANGE; VARIABILITY; PREDICTION AB Climate simulations and forecast experiments of increasingly large ensemble size are being performed to assess the predictive skill of a dynamic model on seasonal and longer timescales. Especially in the cases of ensemble climate simulation or forecast forced by observed or predicted sea surface temperatures, the model is expected to maximize potential predictability due to boundary forcing and to minimize internal variability generated from dynamic instability. In the light of small predictive skill in extratropics from boundary forcing, one must evaluate skill of the ensemble mean quantity against intersample variability or spread of the individual ensemble member. On the other hand, certain dominant signals in climate variability, such as El Nino-Southern Oscillation, have been documented. Predictability for these major signals is the hope of seasonal and climate forecasting using a dynamic model. It may be unrealistic to anticipate a model being able to simulate or forecast the full spectra of climate variability. The question is how to evaluate a model's performance in capturing the dominant climate signals in ensemble experiments with increasingly large sample size. These issues have motivated us to develop a compact methodology for assessing climate experiments with large ensemble size. This method treats the ensemble mean as signal and intersample variability as spread or noise in a common framework. Hence not only dominant signals from boundary forcing can be isolated, but also sensitivity of these signals to the forcing can be assessed. Other potential applications of the method to climate simulation and forecasting are also discussed. C1 NOAA, NATL WEATHER SERV, NATL CTR ENVIRONM PREDICT, ENVIRONM MODELING CTR, WASHINGTON, DC 20233 USA. RES & DATA SYST CORP, GREENBELT, MD USA. RES & GEN SERV CORP, LAUREL, MD USA. RP Wang, XL (reprint author), NOAA, NATL WEATHER SERV, NATL CTR ENVIRONM PREDICT, CLIMATE PREDICT CTR, W-NP24, WASHINGTON, DC 20233 USA. RI Wang, Julian/C-3188-2016 NR 11 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 1996 VL 101 IS D23 BP 29591 EP 29597 DI 10.1029/96JD02901 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WA693 UT WOS:A1996WA69300016 ER PT J AU Eack, KB Beasley, WH Rust, WD Marshall, TC Stolzenburg, M AF Eack, KB Beasley, WH Rust, WD Marshall, TC Stolzenburg, M TI Initial results from simultaneous observation of X rays and electric fields in a thunderstorm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 21st General Assembly of the International-Union-of-Geodesy-and-Geophysics CY 1995 CL BOULDER, CO SP Int Union Geodesy & Geophys ID FLASHES; SYSTEM AB With an X ray detector designed for flight on a free balloon, we obtained a sounding of X ray intensity and electric-field strength in a mesoscale convective system (MCS) near Norman, Oklahoma, in the spring of 1995. The balloon passed through a region of high electric field strength, at which time an increase in X ray intensity of about 2 orders of magnitude occurred, lasting for approximately 1 min. The X ray intensity returned to background levels at the time of a lightning flash that reduced the electric field strength measured at the balloon. This observation suggests that the production mechanism for the X rays we observed is related to the storm electric field and not necessarily to lightning discharge processes. C1 UNIV MISSISSIPPI, DEPT PHYS & ASTRON, UNIVERSITY, MS 38677 USA. UNIV OKLAHOMA, COOPERAT INST MESOSCALE METEOROL STUDIES, NORMAN, OK 73019 USA. NOAA, NATL SEVERE STORMS LAB, NORMAN, OK 73069 USA. RP Eack, KB (reprint author), UNIV OKLAHOMA, SCH METEOROL, NORMAN, OK 73019 USA. OI Stolzenburg, Maribeth/0000-0001-8773-8101 NR 15 TC 82 Z9 81 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 DEC 27 PY 1996 VL 101 IS D23 BP 29637 EP 29640 DI 10.1029/96JD01705 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WA693 UT WOS:A1996WA69300025 ER PT J AU Koneripalli, N Levicky, R Bates, FS Ankner, J Kaiser, H Satija, SK AF Koneripalli, N Levicky, R Bates, FS Ankner, J Kaiser, H Satija, SK TI Confinement-induced morphological changes in diblock copolymer films SO LANGMUIR LA English DT Article ID THIN-FILMS; MICROPHASE SEPARATION; NEUTRON REFLECTIVITY; BLOCK-COPOLYMERS; FREE-SURFACE; TRANSITION; GEOMETRY; LIQUIDS; ISLANDS; GROWTH AB We have studied the ordering behavior of a (diblock copolymer, poly(styrene-d(8))-poly(2-vinylpyridine) (dPS-PVP), in a confined geometry by neutron reflectivity, transmission electron microscopy, and atomic force microscopy. The diblock copolymer was confined between a silicon substrate (Si) on one side and a glassy polymer, poly(2-methylvinylcyclohexane) (P2MVCH), on the other side. In such a geometry, incompatibility between the natural domain period of the diblock copolymer (D*) and the film thickness (L) creates frustration that can be varied by controlling the copolymer film thickness. As the degree of frustration is increased (i.e., film thickness is decreased), the domain periods of the lamellae become progressively distorted from D*, and the lamellae orient with dPS/PVP interfaces parallel to the confining surfaces. The dPS block wets the P2MVCH confining wall and the PVP block wets the Si substrate. There is a limit, however, to the extent of distortion of the lamellar domain period; a further increase in frustration results in a sharp transition to a complex layered morphology that has a heterogeneous in-plane structure adjacent to the P2MVCH confining wall. In this morphology, both the dPS and PVP are located near the P2MVCH confining wall and only PVP is located at the Si confining wall. The sharp transition in the morphology is interpreted in the context of competing surface and bulk interactions. By removal of one of the confining walls, the frustration is relieved and a lamellar structure parallel to the surfaces is recovered with a domain period of D*. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. UNIV MISSOURI,RES REACTOR,COLUMBIA,MO 65211. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. OI Ankner, John/0000-0002-6737-5718; Bates, Frank/0000-0003-3977-1278 NR 42 TC 79 Z9 80 U1 2 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 25 PY 1996 VL 12 IS 26 BP 6681 EP 6690 DI 10.1021/la960608e PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WA877 UT WOS:A1996WA87700078 ER PT J AU Knopp, KJ Christensen, DH Hill, JR AF Knopp, KJ Christensen, DH Hill, JR TI Vertical-cavity surface-emitting lasers with low-ripple optical pump bands SO APPLIED PHYSICS LETTERS LA English DT Article AB We have used multilayer mirror optimization methods to enhance the coupling of pump light into vertical-cavity surface-emitting lasers (VCSELs). With previously reported devices, pump light was coupled into VCSEL cavities through interference notches in the mirror reflectance spectrum. This approach is sensitive to temperature dependent reflectance spectrum shifts. We have created devices with a wide pump-band window of low reflectance. We report the simulation, growth, and optically pumped lasing of such optimized low-ripple VCSELs, Further, broadband pump windows open the possibility of spectrally-bread optical pumps and they eliminate need for costly tunable pump lasers. (C) 1996 American Institute of Physics. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309. RP Knopp, KJ (reprint author), NATL INST STAND & TECHNOL,MS 815-04,325 BROADWAY,BOULDER,CO 80303, USA. NR 6 TC 3 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 23 PY 1996 VL 69 IS 26 BP 3987 EP 3989 DI 10.1063/1.117846 PG 3 WC Physics, Applied SC Physics GA VY894 UT WOS:A1996VY89400009 ER PT J AU Nucci, JA Keller, RR Sanchez, JE ShachamDiamand, Y AF Nucci, JA Keller, RR Sanchez, JE ShachamDiamand, Y TI Local crystallographic texture and voiding in passivated copper interconnects SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTROMIGRATION; METALLIZATION; AL AB A correlation between local crystallographic texture and stress-induced void formation in tantalum-encapsulated, copper interconnects was revealed by electron backscattering diffraction studies in a scanning electron microscope. Lines exhibiting an overall stronger [111] texture showed better resistance to void formation. Furthermore, grains adjacent to voids exhibited weaker [111] texture than grains in unvoided regions of the same line. The locally weaker [111] texture at voided locations suggests the presence of higher diffusivity, twist boundaries, This work, which represents the first characterization of local texture in stress voided, copper lines, helps to elucidate the relative importance of the thermodynamic and kinetic factors which govern void formation and growth. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. RP Nucci, JA (reprint author), CORNELL UNIV,SCH ELECT ENGN,PHILLIPS HALL,ITHACA,NY 14853, USA. RI Keller, Robert/I-9014-2012 NR 19 TC 41 Z9 42 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 23 PY 1996 VL 69 IS 26 BP 4017 EP 4019 DI 10.1063/1.117856 PG 3 WC Physics, Applied SC Physics GA VY894 UT WOS:A1996VY89400019 ER PT J AU Yokoyama, K Leach, GW Kim, JB Lineberger, WC AF Yokoyama, K Leach, GW Kim, JB Lineberger, WC TI Autodetachment spectroscopy and dynamics of dipole bound states of negative ions: (2)A(1)-B-2(1) transitions of H2CCC- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ACETALDEHYDE ENOLATE ANION; PHOTODETACHMENT CROSS-SECTIONS; THRESHOLD RESONANCES; SUPPORTED STATE; MOLECULE; COLLISIONS; SPECTRUM; ROTATION AB The H2CCC- ion is studied by autodetachment spectroscopy in a coaxial laser-ion beam spectrometer. Sharp resonances at photon energies near the photodetachment threshold energy are ascribed to a (2)A(1) <-- B-2(1) transition followed by autodetachment of the dipole-bound state (DBS). Some 2500 rotational transitions are assigned and the band origin is determined to be 14 284.420(5) cm(-1). The observation of individual rotational lines allowed determination of the rotational spectroscopic constants as A=9.651 53(4) cm(-1) and (B + C)/2=0.346 461(3) cm(-1) for the DBS as well as the spin-rotation coupling constant epsilon(aa)=2.17(6)x10(-3) cm(-1). Based on an electron affinity of 14 469+/-64 cm(-1), the binding energy of the electron in the DBS is 170+/-50 cm(-1). Anomalous rotational line positions are found in the vicinity of K-a=7-10 in the DBS and have been attributed to the centrifugal distortion couplings caused by mixing with the CCC out-of-plane bending mode (nu(6)) and the CCC in-plane bending mode (nu(9)). The linewidths provide information about autodetachment rates that make it possible to obtain electron detachment dynamics for individual rotational states. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Yokoyama, K (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 43 TC 36 Z9 36 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 1996 VL 105 IS 24 BP 10696 EP 10705 DI 10.1063/1.472878 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VZ371 UT WOS:A1996VZ37100005 ER PT J AU Yokoyama, K Leach, GW Kim, JB Lineberger, WC Boldyrev, AI Gutowski, M AF Yokoyama, K Leach, GW Kim, JB Lineberger, WC Boldyrev, AI Gutowski, M TI Autodetachment spectroscopy and dynamics of vibrationally excited dipole-bound states of H2CCC- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INDUCED ELECTRON DETACHMENT; PERTURBATION-THEORY; INFRARED-SPECTRUM; MOLECULAR ANIONS; PROPENSITY RULES; BASIS-SETS; ENERGY; CH2CN AB Direct observation of the rotational fine structure levels of a vibrationally excited negative ion dipole-bound state (DBS) is reported. Autodetachment resonances of H2CCC- were observed for the (2)A(1)-B-2(1) transition in one quanta of nu(6), nu(4), and nu(2) and two quanta of nu(6) vibrational modes of the DBS. Rotational assignments for both the electronic ground state and the DBS were performed. Strong type (a) Coriolis coupling between nu(6) and vg in both the electronic ground and excited states was observed, and coupling constants were determined, QCISD ab initio calculations were performed for the ground state, the negative ion, and the neutral state of H2CCC. The calculations on the neutral agree well with measured vibrational frequencies of the dipole-bound state. The autodetachment resonances contain information about the detachment dynamics via the observed linewidths, showing, e.g., that motions along the dipole moment axis significantly enhance autodetachment, indicating that the DBS is unstable with respect to neutral core motion which modulates the magnitude value of the dipole moment. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM ENGN,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV UTAH,DEPT CHEM,SALT LAKE CITY,UT 84112. RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 41 TC 50 Z9 50 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 1996 VL 105 IS 24 BP 10706 EP 10718 DI 10.1063/1.472879 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VZ371 UT WOS:A1996VZ37100006 ER PT J AU Viehland, LA Hurly, JJ AF Viehland, LA Hurly, JJ TI Absence of quantum-mechanical effects on the mobility of argon ions in helium gas at 4.35 K SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSPORT-COEFFICIENTS; 3-TEMPERATURE THEORY; HE GAS; RANGE; AR+ AB Quantum-mechanical transport cross sections are accurately computed from recent spectroscopic potentials for the three lowest energy levels of the molecular ion HeAr+. Statistical and ground state combinations of the cross sections are used to compute the transport coefficients describing the motion of Ar+ ions through He gas at 4.35 K. The calculated mobilities do not show the rapid decrease of the experimental values as the ratio of the electric field strength to the gas number, density becomes very small. The experimental observations therefore are not due to the effects of orbiting resonance. (C) 1996 American Institute of Physics. C1 NIST,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. RP Viehland, LA (reprint author), ST LOUIS UNIV,PARKS COLL,DEPT CHEM,CAHOKIA,IL 62206, USA. NR 20 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 1996 VL 105 IS 24 BP 11143 EP 11146 DI 10.1063/1.472914 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VZ371 UT WOS:A1996VZ37100051 ER PT J AU Mackenzie, SR Votava, O Fair, JR Nesbitt, DJ AF Mackenzie, SR Votava, O Fair, JR Nesbitt, DJ TI ''Gentle recoil'' synthesis of free-radical clusters via unimolecular photolysis of closed shell complexes SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC SPECTROSCOPY; AROH; STATE; SH AB We describe a novel mechanism for efficient generation of open shell free-radical complexes via UV photolysis of the corresponding closed shell precursors. Ar-SH and Ar-2-SH are detected following 248 nm excitation of Ar-H2S and Ar-2-H2S. Of particular dynamical interest are the nonfragmentary channels in which no Ar atoms are ejected. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Mackenzie, SR (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 19 TC 16 Z9 16 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 1996 VL 105 IS 24 BP 11360 EP 11363 DI 10.1063/1.472985 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VZ371 UT WOS:A1996VZ37100075 ER PT J AU Zhu, PL Snyder, LR Dolan, JW Djordjevic, NM Hill, DW Sander, LC Waeghe, TJ AF Zhu, PL Snyder, LR Dolan, JW Djordjevic, NM Hill, DW Sander, LC Waeghe, TJ TI Combined use of temperature and solvent strength in reversed-phase gradient elution .1. Predicting separation as a function of temperature and gradient conditions SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE gradient elution; solvent strength; column temperature; retention prediction; computer simulation ID LIQUID-CHROMATOGRAPHIC SEPARATIONS; COMPUTER-SIMULATION; PROTEIN SAMPLES; BAND-WIDTH; RETENTION; SELECTIVITY; MIXTURES; PEPTIDE; VERIFICATION; ACCURACY AB It has been shown previously that computer simulation based on two initial experiments can predict separation in reversed-phase gradient elution as a function of gradient conditions (gradient steepness, gradient range and gradient shape) and column conditions (column length, flow-rate and particle size). The present study extends this capability for changes in temperature. Four initial experiments (two different gradient times, two different temperatures) provide input data that allow predictions of separation as a function of temperature as well as gradient and column conditions. A semi-empirical relationship, t(R) = a+bT, is able to relate gradient retention time t(R) to column temperature T (other conditions constant). The accuracy of this approach has been evaluated for 102 solutes and a variety of experimental conditions, including the use of five different HPLC instruments (four different models). C1 LC RESOURCES INC,WALNUT CREEK,CA 94596. SANDOZ PHARMA AG,PRECLIN RES,CH-4002 BASEL,SWITZERLAND. UNIV CONNECTICUT,MICROCHEM LAB,STORRS,CT 06269. NATL INST STAND & TECHNOL,DIV ANALYT CHEM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. DU PONT AGR PROD,EXPT STN,WILMINGTON,DE 19880. LANZHOU UNIV,DEPT CHEM,LANZHOU 730000,GANSU,PEOPLES R CHINA. NR 39 TC 131 Z9 131 U1 1 U2 15 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 DEC 20 PY 1996 VL 756 IS 1-2 BP 21 EP 39 DI 10.1016/S0021-9673(96)00721-2 PG 19 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WC976 UT WOS:A1996WC97600002 PM 9008855 ER PT J AU Zhu, PL Dolan, JW Snyder, LR Djordjevic, NM Hill, DW Lin, JT Sander, LC VanHeukelem, L AF Zhu, PL Dolan, JW Snyder, LR Djordjevic, NM Hill, DW Lin, JT Sander, LC VanHeukelem, L TI Combined use of temperature and solvent strength in reversed-phase gradient elution .4. Selectivity for neutral (non-ionized) samples as a function of sample type and other separation conditions SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE column temperature; selectivity; gradient elution; gradient steepness; polynuclear aromatic hydrocarbon; nitroaromatics; fatty acid methyl ester; carotenoids; pharmaceuticals; non-basic drugs ID PERFORMANCE LIQUID-CHROMATOGRAPHY; POLYCYCLIC AROMATIC-HYDROCARBONS; FATTY-ACIDS; OPTIMIZATION AB The separation of nine un-ionized samples was studied as a function of temperature (T) and gradient steepness (b). Selectivity values Delta log alpha* were obtained for 160 compounds, ranging from nonpolar hydrocarbons to very polar drugs. Selectivity varied markedly with sample type: nonpolar compounds such as aromatic hydrocarbons and fatty acid methyl esters generally showed only modest changes in band spacing as temperature or gradient steepness was varied. More polar samples exhibited larger changes in alpha (Delta log alpha*) when temperature and/or gradient steepness were changed, but the largest values of Delta log alpha* for these non-ionized samples are less than the average value of Delta log alpha* for the ionized samples of Part III [1]. Poly-functional silane (''polymeric'') columns exhibit slightly increased b- and/or T-selectivity for some samples. C1 LC RESOURCES INC,WALNUT CREEK,CA 94596. SANDOZ PHARMA LTD,PRECLIN RES,CH-4002 BASEL,SWITZERLAND. UNIV CONNECTICUT,MICROCHEM LAB,STORRS,CT 06269. USDA,WESTERN REG RES CTR,ALBANY,CA 94710. NATL INST STAND & TECHNOL,DIV ANALYT CHEM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV MARYLAND,HORN POINT ENVIRONM LAB,CTR ENVIRONM & ESTUARINE STUDIES,CAMBRIDGE,MD 21613. LANZHOU UNIV,DEPT CHEM,LANZHOU 730000,GANSU PROV,PEOPLES R CHINA. NR 23 TC 75 Z9 76 U1 0 U2 2 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 DEC 20 PY 1996 VL 756 IS 1-2 BP 63 EP 72 DI 10.1016/S0021-9673(96)00724-8 PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WC976 UT WOS:A1996WC97600005 ER PT J AU Zheng, J Weinheimer, AJ Ridley, BA Liu, SC Sachse, GW Anderson, BE Collins, JE AF Zheng, J Weinheimer, AJ Ridley, BA Liu, SC Sachse, GW Anderson, BE Collins, JE TI Analysis of small- and large-scale increases of reactive nitrogen observed during the Second Airborne Arctic Stratospheric Expedition SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIRCRAFT EXHAUST PLUMES; AASE-II; UPPER TROPOSPHERE; NITRIC-OXIDE; OZONE; PACIFIC; NOX; DISTRIBUTIONS; EASTERN; IMPACT AB An analysis of the data obtained during AASE II was made to characterize small- (delta x < 24 km) and large-scale (30 < delta x < 260 km) increases of reactive nitrogen species. By using the NOx/NOy ratio, the increases were classified into fresh emissions and aged air parcels. The sources of the NOy increases were then assessed by the freshness of the increases and by examining the correlation (or absence thereof) between NOy and other trace species including tracers of various NOx sources: for example, aircraft emissions, lightning, the stratospheric source, and sources in the boundary layer. We found that the majority (43%) of NOy increases in the upper troposphere and lower stratosphere were due to displacement of constant mixing ratio surfaces relative to isobaric flight paths. Aircraft emissions were the second most abundant (17%). The next significant contributor was surface emissions, including fossil fuel combustion and biomass burning. Only two lightning spikes were found, apparently due to the winter season and emphasis on high latitudes in the AASE II experiment. The relative contribution from each source to the increases (or positive variability) represents a measure of the relative source strength. However, it is important to note that our findings on the relative contribution of each source to the NOy increases should not be applied directly to estimating the relative source strength of the ambient or background NOy abundance. Knowledge of the detailed temporal and spatial distribution of the relative contribution of each source is needed. This requires a substantially higher precision for the instruments of tracer gases than those used in this study. C1 NASA, LANGLEY RES CTR, HAMPTON, VA 23681 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. SCI & TECHNOL CORP, HAMPTON, VA 23666 USA. RP Zheng, J (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. NR 28 TC 5 Z9 5 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 DEC 20 PY 1996 VL 101 IS D22 BP 28805 EP 28816 DI 10.1029/96JD02034 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800016 ER PT J AU Fehsenfeld, FC Trainer, M Parrish, DD VolzThomas, A Penkett, S AF Fehsenfeld, FC Trainer, M Parrish, DD VolzThomas, A Penkett, S TI North Atlantic Regional Experiment 1993 summer intensive: Foreword SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID TROPOSPHERIC OZONE; CARBON-MONOXIDE; SURFACE OZONE; STRATOZ-III; OCEAN; TRANSPORT; POLLUTION; DISTRIBUTIONS; CONSTITUENTS; HYDROCARBONS C1 UNIV E ANGLIA, SCH ENVIRONM SCI, NORWICH NR4 7TJ, NORFOLK, ENGLAND. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST CHEM & DYNAM GEOSPHARE, JULICH, GERMANY. RP NOAA, AERON LAB, 325 BROADWAY, R-E-AL7, BOULDER, CO 80303 USA. RI Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Volz-Thomas, Andreas/J-7223-2012 OI Parrish, David/0000-0001-6312-2724; Volz-Thomas, Andreas/0000-0003-3700-1667 NR 44 TC 31 Z9 31 U1 0 U2 0 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 DEC 20 PY 1996 VL 101 IS D22 BP 28869 EP 28875 DI 10.1029/95JD03629 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800022 ER PT J AU Fehsenfeld, FC Daum, P Leaitch, WR Trainer, M Parrish, DD Hubler, G AF Fehsenfeld, FC Daum, P Leaitch, WR Trainer, M Parrish, DD Hubler, G TI Transport and processing of O-3 and O-3 precursors over the North Atlantic: An overview of the 1993 North Atlantic Regional Experiment (NARE) summer intensive SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE AB In the summer of 1993, airborne and ground-based measurements of O-3 and O-3 precursors were made in the North Atlantic region. These studies were made by an international team of scientists collaborating as part of the North Atlantic Regional Experiment, an activity of the International Global Atmospheric Chemistry project of the International Geosphere-Biosphere Program, Previous measurements [cf. Fehsenfeld et al., this issue] have indicated that the amount of O-3 produced from anthropogenic sources is greater than that reaching the lower troposphere in this region from the stratosphere and that ozone derived from anthropogenic pollution has a hemisphere wide effect at northern temperate latitudes. In this special issue the recently acquired data are used to better quantify the contribution of continental sources to the ozone levels over the North Atlantic. The aim of this overview is to provide the operational and logistical context of the study and to introduce the principal findings and conclusions that have been drawn from the results. C1 BROOKHAVEN NATL LAB, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. ATMOSPHER ENVIRONM SERV, CLOUD PHYS RES DIV, DOWNSVIEW, ON M3H 5T4, CANADA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80303 USA. RP US DEPT COMMERCE, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Hubler, Gerhard/E-9780-2010 OI Parrish, David/0000-0001-6312-2724; NR 15 TC 77 Z9 78 U1 0 U2 17 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 DEC 20 PY 1996 VL 101 IS D22 BP 28877 EP 28891 DI 10.1029/96JD01113 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800023 ER PT J AU Angevine, WM Trainer, M McKeen, SA Berkowitz, CM AF Angevine, WM Trainer, M McKeen, SA Berkowitz, CM TI Mesoscale meteorology of the New England coast, Gulf of Maine, and Nova Scotia: Overview SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INTERNAL BOUNDARY-LAYER; COOLER SEA; WARM AIR; OZONE; TRANSPORT; ADVECTION; DYNAMICS; WATER; OCEAN; WIND AB The North Atlantic Regional Experiment (NARE) domain includes the coastal and near-coastal areas of New England and Atlantic Canada, and the intervening Gulf of Maine. This area has a complex coastline on all scales. The meteorology of the region is affected by the contrasting properties of the land and ocean, especially the temperature contrast. This paper reviews the knowledge of coastal meteorology on scales from tens of meters to 100 km, emphasizing those processes that most strongly affect pollutant transport in the NARE area in summertime. Examples from the NARE 1993 Summer Intensive measurements and modeling studies are used to illustrate these processes. The understanding and interpretation of regional and global air quality measurements depend on meteorological information about such issues as the amount and location of vertical mixing, the three-dimensional trajectories of air parcels, the prevalence and scale of stratification, the speed of horizontal transport, and the scale of horizontal homogeneity or inhomogeneity. These issues are among those not fully understood in the complex coastal environment. From what is known, and from the NARE measurements, we can draw some conclusions. Polluted air from the U.S. East Coast transported over the Gulf of Maine becomes stably stratified, and vertical mixing is limited. The scale of vertical layering may be a few tens of meters or less. Layers separated by a few hundred meters in the vertical over Nova Scotia may have crossed the U.S. coast at points hundreds of kilometers apart. Wind speeds and directions, and therefore transport times, may differ substantially between the layers. Air at the surface may be isolated from, and have drastically different chemical contents from, air at only a few hundred meters above the surface. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Angevine, WM (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; Angevine, Wayne/H-9849-2013; McKeen, Stuart/H-9516-2013 OI Angevine, Wayne/0000-0002-8021-7116; NR 24 TC 36 Z9 36 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 DEC 20 PY 1996 VL 101 IS D22 BP 28893 EP 28901 DI 10.1029/95JD03271 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800024 ER PT J AU Angevine, WM Buhr, MP Holloway, JS Trainer, M Parrish, DD MacPherson, JI Kok, GL Schillawski, RD Bowlby, DH AF Angevine, WM Buhr, MP Holloway, JS Trainer, M Parrish, DD MacPherson, JI Kok, GL Schillawski, RD Bowlby, DH TI Local meteorological features affecting chemical measurements at a North Atlantic coastal site SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; TURBULENCE STRUCTURE; WIND PROFILER; DYNAMICS; OCEAN; SEA AB One of the foci of the North Atlantic Regional Experiment (NAPE) 1993 summer intensive campaign was Chebogue Point, approximately 10 km south of Yarmouth, Nova Scotia. Measurements were taken at this site with a 915-MHz boundary layer wind profiler, the Canadian Twin Otter and National Center for Atmospheric Research King Air aircraft, and a variety of surface instruments. This paper discusses features observed in the meteorological measurements and the implications of those features for the interpretation of chemical measurements. The meteorology of this coastal site is complex. A strong surface-based temperature inversion was almost always present, producing strong layering in the lower atmosphere. As a result, surface chemistry measurements were not often representative of the state of the overlying atmosphere. A low-level jet was also frequently present. A variety of turbulence structures were observed by the profiler, including convective boundary layers and complex layering. Ozone concentrations above 60 parts per billion at the surface occurred on four occasions late in August, in conjunction with strong stability and winds off the Atlantic Ocean (Gulf of Maine). Ozone levels of more than 60 ppbv were observed by the aircraft at altitudes between 400 and 1600 m on five other occasions earlier in the month. Particular (but not necessarily unusual) combinations of transport, mixing, and source conditions appear to be required to produce ozone episodes at Chebogue Point. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. ENVIRONM CANADA, BEDFORD, NS, CANADA. NATL RES COUNCIL CANADA, FLIGHT RES LAB, OTTAWA, ON, CANADA. RP Angevine, WM (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; Parrish, David/E-8957-2010; Angevine, Wayne/H-9849-2013; Holloway, John/F-9911-2012 OI Parrish, David/0000-0001-6312-2724; Angevine, Wayne/0000-0002-8021-7116; Holloway, John/0000-0002-4585-9594 NR 25 TC 15 Z9 15 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 DEC 20 PY 1996 VL 101 IS D22 BP 28935 EP 28946 DI 10.1029/95JD02890 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800027 ER PT J AU Roberts, JM Parrish, DD Norton, RB Bertman, SB Holloway, JS Trainer, M Fehsenfeld, FC Carroll, MA Albercook, GM Wang, T Forbes, G AF Roberts, JM Parrish, DD Norton, RB Bertman, SB Holloway, JS Trainer, M Fehsenfeld, FC Carroll, MA Albercook, GM Wang, T Forbes, G TI Episodic removal of NOy species from the marine boundary layer over the North Atlantic SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; PEROXYACETYL NITRATE PAN; ODD-NITROGEN NOY; ORGANIC NITRATES; UNITED-STATES; ALKYL NITRATES; REACTIVE NITROGEN; NITRIC-OXIDE; NIWOT-RIDGE; RURAL SITE AB Measurements of ozone, carbon monoxide, NOy, NOx, HNO3, particulate NO3-, PAN, PPN, and alkyl nitrates were made at Chebogue Point, Nova Scotia, during July, August, and September 1993, and measurements of ozone, carbon monoxide, NOx and NOy were made at Sable Island, Nova Scotia, during August and September 1993 as part of the North Atlantic Regional Experiment (NARE). Periods of photochemical pollution were observed during which concentrations of the above species were elevated relative to average conditions. The best indicator of the extent of impact was found to be the sum of the C-1-C-4 alkyl nitrates. The removal of PAN and PPN by fog droplets through thermal decomposition and subsequent uptake of the peroxyacetyl and peroxypropionyl radicals (PA and PP) was suggested by loss of PAN and PPN during fog. The effect of this chemistry on NOy species in the marine environment will need to be considered. The loss of inorganic nitrate (HNO3 and particulate NO3-), PAN (and to a minor extent PPN) resulted in deviation of the O-3 versus NOy-NOx correlations from that observed in eastern North America. C1 NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80303 USA. UNIV COLORADO, BOULDER, CO 80303 USA. UNIV MICHIGAN, DEPT ATMOSPHER OCEAN & SPACE SCI, ANN ARBOR, MI 48109 USA. ATMOSPHER ENVIRONM SERV, SABLE ISL, NS, CANADA. RP Roberts, JM (reprint author), NOAA, ENVIRONM RES LABS, AERON LAB, 325 BROADWAY, R-E-AL7, BOULDER, CO 80303 USA. RI Roberts, James/A-1082-2009; Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; WANG, Tao/B-9919-2014 OI Roberts, James/0000-0002-8485-8172; Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; WANG, Tao/0000-0002-4765-9377 NR 54 TC 37 Z9 37 U1 2 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 DEC 20 PY 1996 VL 101 IS D22 BP 28947 EP 28960 DI 10.1029/96JD02632 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800028 ER PT J AU Wang, T Carroll, MA Albercook, GM Owens, KR Duderstadt, KA Markevitch, AN Parrish, DD Holloway, JS Fehsenfeld, FC Forbes, G Ogren, J AF Wang, T Carroll, MA Albercook, GM Owens, KR Duderstadt, KA Markevitch, AN Parrish, DD Holloway, JS Fehsenfeld, FC Forbes, G Ogren, J TI Ground-based measurements of NOx and total reactive oxidized nitrogen (NOy) at Sable Island, Nova Scotia, during the NARE 1993 summer intensive SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; UNITED-STATES; TROPOSPHERIC OZONE; CARBON-MONOXIDE; NITRIC-OXIDE; EASTERN PACIFIC; RURAL SITE; OCEAN; 19TH-CENTURY; ATMOSPHERE AB Measurements of NO, NO2, and total reactive oxidized nitrogen (NOy) were added to ongoing measurements of aerosols, CO, and O-3 at Sable Island (43 degrees 55'N,'60 degrees 01'W), Nova Scotia, during the North Atlantic Regional Experiment (NARE) 1993 summer intensive. Ambient levels of NOx and NOy were found to be highly variable, and elevated levels can be attributed to the transport of polluted continental air or presumably to relatively fresh emissions from sources upwind (e.g., ship traffic). The median values for NOx and NOy are 98 and 266 parts per trillion by volume (pptv), respectively. A multiday pollution episode occurred during which elevated NOx and NO were observed with enhanced levels of O-3, CO, and condensation nuclei. Air masses of recent tropical marine origin characterized by low and constant levels of O-3 and CO were sampled after Hurricane Emily. The correlation between ozone and CO is reasonably good, although the relation is driven by the single pollution episode observed during the study. The correlation of O-3 with NOy and with NOy-NOx is complicated by the presumed NOy removal processes in the marine boundary layer. Examination of the radiosonde data and comparisons of the surface data with those obtained on the overflying aircraft provide clear indications of vertical stratification above the site. C1 UNIV MICHIGAN, DEPT ATMOSPHER OCEAN & SPACE SCI, ANN ARBOR, MI 48109 USA. UNIV MICHIGAN, DEPT CHEM, ANN ARBOR, MI 48109 USA. ATMOSPHER ENVIRONM SERV, SABLE ISL, NS, CANADA. NOAA, AERON LAB, BOULDER, CO 80303 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RI Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Fehsenfeld, Frederick/I-4876-2013; WANG, Tao/B-9919-2014 OI Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; WANG, Tao/0000-0002-4765-9377 NR 42 TC 24 Z9 25 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 DEC 20 PY 1996 VL 101 IS D22 BP 28991 EP 29004 DI 10.1029/96JD01090 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800031 ER PT J AU Buhr, M Sueper, D Trainer, M Goldan, P Kuster, B Fehsenfeld, F Kok, G Shillawski, R Schanot, A AF Buhr, M Sueper, D Trainer, M Goldan, P Kuster, B Fehsenfeld, F Kok, G Shillawski, R Schanot, A TI Trace gas and aerosol measurements using aircraft data from the North Atlantic Regional Experiment (NARE 1993) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ODD-NITROGEN NOY; PRINCIPAL COMPONENT ANALYSIS; AMBIENT AIR MEASUREMENTS; CARBON-MONOXIDE; HIGH-SENSITIVITY; NITRIC-OXIDE; OZONE; TROPOSPHERE AB Measurements of the concentrations of O-3, CO, NO, NOy, condensation nuclei, and aerosols in 12 size bins ranging from 0.1 to 3.1 mu m as well as a variety of meteorological parameters were collected aboard the NCAR King Air in August 1993 during 16 flights over or near the Gulf of Maine. The purpose of this measurement campaign was to describe the sources and variation of ozone and its precursors in the western NARE region during the summer season. Correlations between O-3 and CO, O-3 and NOy, and other chemical and aerosol measurements are examined. Several features in the altitude profiles are investigated using principal component analysis, The results of the trace gas analyses indicate that anthropogenically influenced ozone production dominated ozone throughout the experimental region at altitudes below 1500 m. Other factors identified include a distinct signature from fresh emissions below 1500 m. Above 1500 m the sources of ozone were determined by transport from a variety of sources. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NATL CTR ATMOSPHER RES, RES AVIAT FACIL, BOULDER, CO 80303 USA. RP Buhr, M (reprint author), NOAA, AERON LAB, R-E-AL7, 325 BROADWAY, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Kuster, William/E-7421-2010 OI Kuster, William/0000-0002-8788-8588 NR 30 TC 24 Z9 25 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 DEC 20 PY 1996 VL 101 IS D22 BP 29013 EP 29027 DI 10.1029/96JD01159 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800033 ER PT J AU Daum, PH Kleinman, LI Newman, L Luke, WT WeinsteinLloyd, J Berkowitz, CM Busness, KM AF Daum, PH Kleinman, LI Newman, L Luke, WT WeinsteinLloyd, J Berkowitz, CM Busness, KM TI Chemical and physical properties of plumes of anthropogenic pollutants transported over the North Atlantic during the North Atlantic Regional Experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EASTERN-UNITED-STATES; GAS-PHASE PEROXIDES; RURAL SITE; NONENZYMATIC METHOD; HYDROGEN-PEROXIDE; OZONE PRODUCTION; TRACE GAS; PHOTOCHEMISTRY; TROPOSPHERE; HYDROPEROXIDES AB Plumes of photochemical pollutants transported from the industrialized regions of the northeast United States and Canada were sampled over the North Atlantic Ocean at distances up to 1000 km from the coast. The plumes were found in well defined layers up to 1 km thick and were usually isolated from the surface by a low altitude inversion. Plume composition was consistent with the occurrence of extensive photochemical processing during transit from source regions as indicated by high O-3 concentrations (O-3 maximum similar to 150 parts per billion by volume (ppbv)), generally high fractional conversion (>85%) of NOx to its oxidation products, and high peroxide concentrations (median 3.6 ppbv; maximum 11 ppbv). These observations are in accord with processing times estimated from back trajectory analysis. CO and O-3 Concentrations were well correlated (r(2) = 0.64) with a slope (0.26) similar to previous measurements in photochemically aged air. Good correlations were also observed between CO and accumulation mode particle number densities (r(2) = 0.64), and CO and NOy (r(2) = 0.67). O-3 was found to depend nonlinearly on the NOx oxidation product concentration. At low values of (NOy-NOx), the slope (14) was within the range of values measured previously in photochemically aged air masses, at higher concentrations the slope was much lower (4.6). The low slope at high concentrations is attributed to minimization of losses of NOx oxidation products in spatially well-defined plumes during transport. A strong linear correlation (r(2) = 0.73) was found between O-3, and the concentration of radical sink species as represented by the quantity ((NOy-NOx) + 2H(2)O(2)). C1 NOAA, AIR RESOURCES LAB, SILVER SPRING, MD 20910 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Daum, PH (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. RI Luke, Winston/D-1594-2016 OI Luke, Winston/0000-0002-1993-2241 NR 36 TC 49 Z9 49 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 DEC 20 PY 1996 VL 101 IS D22 BP 29029 EP 29042 DI 10.1029/95JD03163 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800034 ER PT J AU Kleinman, LI Daum, PH Springston, SR Leaitch, WR Banic, CM Isaac, GA Jobson, BT Niki, H AF Kleinman, LI Daum, PH Springston, SR Leaitch, WR Banic, CM Isaac, GA Jobson, BT Niki, H TI Measurement of O-3 and related compounds over southern Nova Scotia .2. Photochemical age and vertical transport SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PACIFIC AIR MASSES; POINT-ARENA; TROPOSPHERE; CALIFORNIA; HISTORIES; CANADA AB Chemical measurements of O-3 and other trace substances in the atmosphere over southern Nova Scotia, obtained during 48 flights of the National Research Council of Canada Twin Otter aircraft, provide evidence for a variable degree of processing associated with transport times ranging from less than 1 day to 5 days or more. Effects of chemical aging and dilution are determined using photochemical age estimates derived from the ratios. In (n-butane/propane) and In (i-butane/propane). Age estimates are used in a qualitative sense to divide the data set into four age groups. Vertical profiles and relations between O-3 and other trace substances are examined as a function of age group. We find that high-O-3 events occurring in dry air are in the oldest age category. Moist high-O-3 events have photochemical ages that span all four age categories, but the most polluted episodes are only observed in relatively ''new air.'' A geographically wide range of emission regions is suggested by the hydrocarbon measurements, which is consistent with back trajectory results. The relative depletion of soluble substance (i.e., aerosol particles and NOy) in dry, relative to moist, high-O-3 air masses is discussed with respect to the dilution or precipitation scavenging that must accompany the transport of pollutants from the boundary layer to the dryer middle or upper troposphere. Four case studies are presented that span a wide range of conditions associated with high O-3 concentrations. In a pair of these cases, samples were obtained in air masses having about the same photochemical age, altitude, and C2H2 and O-3 concentration. One of the pair was from dry air and the other from moist air. The dry air mass had much lower concentrations of NOy and aerosol particles, which was interpreted as evidence for the selective removal of soluble constituents during vertical lifting. The other case studies illustrate a biomass burning plume and the effects of a stable layer over the ocean on transport. C1 ATMOSPHER ENVIRONM SERV, CLOUD PHYS RES DIV, DOWNSVIEW, ON M3H 5T4, CANADA. NOAA, AERON LAB, BOULDER, CO 80303 USA. YORK UNIV, CTR ATMOSPHER CHEM, N YORK, ON M3J 1P3, CANADA. RP Kleinman, LI (reprint author), BROOKHAVEN NATL LAB, ENVIRONM CHEM DIV, POB 5000, UPTON, NY 11973 USA. NR 17 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 DEC 20 PY 1996 VL 101 IS D22 BP 29061 EP 29074 DI 10.1029/95JD03787 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800036 ER PT J AU Lin, X Zaucker, F Hsie, EY Trainer, M McKeen, SA AF Lin, X Zaucker, F Hsie, EY Trainer, M McKeen, SA TI Radon 222 simulations as a test of a three-dimensional regional transport model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLOUD TRANSPORT; RN-222; TRACER; AIR; PACIFIC; SOIL AB Radon 222 distributions during the 1993 North Atlantic Regional Experiment are simulated with the National Oceanic and Atmospheric Administration Aeronomy Laboratory three-dimensional regional transport model. The model domain covers the western part of the North Atlantic Ocean and part of the eastern United States and Canada. It horizontally elongates 4200 km in the east-west and north-south directions and vertically extends from the surface to 50 mbar. The model simulates emissions, transport, and radioactive decay of Rn-222. Advection, cloud transport, mixing in the planetary boundary layer, and diffusion are simulated and the emissions, boundary, and initial conditions are parameterized. The model results are analyzed to study the ability of the model to simulate Rn-222 distribution in the troposphere. The analysis indicates that Rn-222 simulations near the surface are dominated by emissions. At altitudes from <1 km to similar to 6 km the simulations are noticeably influenced by the side boundaries and the influence increases with increasing altitude. Radon 222 simulations in the upper troposphere (z > 6 km) are dominated by side boundary conditions and the wind field. The impact of top boundary on Rn-222 simulations is negligible provided the top is specified at an altitude well above the tropopause. Cloud mixing is important in the vertical transport of Rn-222 from the surface to the free troposphere. Cloud effect is significant in Rn-222 distributions at grid columns within or near which there are abundant clouds. The mean effect of cloud mixing cannot be appropriately represented by contrasting large-scale or long-term average Rn-222 distributions simulated in cases with and without cloud mixing. Surface pressure fluctuation has substantial influence on Rn-222 emission and concentration variabilities, but this effect is restricted to altitudes near the surface. The model-simulated Rn-222 concentrations are compared with measurements made onboard the U.S. Department of Energy Gulfstream aircraft based at Halifax, Nova Scotia, to evaluate the quality of the simulations. The comparison indicates that the simulations and observations are usually within a factor of 2 of one another and significantly correlated with each other. The simulations are capable of capturing high Rn-222 concentrations observed in continental plumes. C1 COLUMBIA UNIV, DEPT APPL PHYS, NEW YORK, NY 10027 USA. UNIV COLORADO, CIRES, BOULDER, CO 80309 USA. RP Lin, X (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; McKeen, Stuart/H-9516-2013; Hsie, Eirh-Yu/I-4449-2013 OI Hsie, Eirh-Yu/0000-0003-3934-9923 NR 44 TC 12 Z9 12 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1996 VL 101 IS D22 BP 29165 EP 29177 DI 10.1029/96JD00100 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800045 ER PT J AU Oltmans, SJ Levy, H Harris, JM Merrill, JT Moody, JL Lathrop, JA Cuevas, E Trainer, M ONeill, MS Prospero, JM Vomel, H Johnson, BJ AF Oltmans, SJ Levy, H Harris, JM Merrill, JT Moody, JL Lathrop, JA Cuevas, E Trainer, M ONeill, MS Prospero, JM Vomel, H Johnson, BJ TI Summer and spring ozone profiles over the North Atlantic from ozonesonde measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BERMUDA AB Ozone profiles obtained by near-daily ozonesonde observations during campaigns at several sites in the North Atlantic are used to construct time-height cross sections of ozone concentration through the troposphere, Strong day-to-day ozone variability on the scale of synoptic meteorological disturbances is found both in the spring and in the summer throughout much of the troposphere. Layers of high ozone concentration (similar to 100 ppb) are frequently seen in the middle and upper troposphere and are invariably associated with transport characteristics that strongly support a stratospheric source for these layers. Regions of low ozone (<40 ppb) are seen in the middle and upper troposphere associated with higher relative humidity. The connection of these events with low surface mixing ratios suggests that convective processes mix air low in ozone up through the troposphere. Vertical layering of ozone mixing ratio, which is seen at all of the observing locations, is a result of differing sources of air in the different layers. C1 PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. UNIV RHODE ISL, GRAD SCH OCEANOG, NARRAGANSETT, RI 02882 USA. UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA. IZANA BASELINE OBSERV, TENERIFE, SPAIN. NOAA, AERON LAB, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP Oltmans, SJ (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, 325 BROADWAY, R-E-CG1, BOULDER, CO 80303 USA. RI Trainer, Michael/H-5168-2013; Cuevas, Emilio/L-2109-2013; OI Cuevas, Emilio/0000-0003-1843-8302; Prospero, Joseph/0000-0003-3608-6160 NR 14 TC 76 Z9 76 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1996 VL 101 IS D22 BP 29179 EP 29200 DI 10.1029/96JD01713 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800046 ER PT J AU Merrill, JT Moody, JL Oltmans, SJ Levy, H AF Merrill, JT Moody, JL Oltmans, SJ Levy, H TI Meteorological analysis of tropospheric ozone profiles at Bermuda SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POTENTIAL VORTICITY; ATLANTIC-OCEAN; NORTH-ATLANTIC; ATMOSPHERE; POLLUTION; EXCHANGE; FORCES; EXPORT AB As part of the North Atlantic Regional Experiment (NARE) a number of ozonesonde profiles were obtained from Bermuda during the spring and summer of 1993. We present meteorological case studies of two instances of elevated O-3 mixing ratio in the middle and upper troposphere which took place during the summer. The ozonesonde profile of July 9, 1993, indicated ozone mixing ratios exceeding 100 parts per billion by volume (ppbv) from similar to 5 km to above 15 km above sea level. A series of profiles for August 2-4 indicated elevated ozone in a layer which initially extended from 8 to 9 km and thickened to cover the 8- to 14-km range, Isentropic trajectories lead back to potential source areas over North America 2 to 5 days prior to the events, Objective analyses based on radiosonde data demonstrate that the air masses, as indicated by the trajectories, pass through areas of elevated isentropic potential vorticity located in troughs in the tropopause-level geopotential height field. The conformation and temporal development suggest that active planetary wave breaking was responsible for stratosphere-troposphere exchange in these systems, These results suggest an important role for O-3 of stratospheric origin in the western North Atlantic Ocean area, transported into the troposphere upstream over or near North America, It is notable that these events took place in the summer months of July and August, when such events had been considered unlikely. C1 PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP Merrill, JT (reprint author), UNIV RHODE ISL, GRAD SCH OCEANOG, CTR ATMOSPHER SCI, S FERRY RD, NARRAGANSETT, RI 02882 USA. NR 24 TC 20 Z9 20 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 DEC 20 PY 1996 VL 101 IS D22 BP 29201 EP 29211 DI 10.1029/95JD03432 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800047 ER PT J AU Moody, JL Davenport, JC Merrill, JT Oltmans, SJ Parrish, DD Holloway, JS Levy, H Forbes, GL Trainer, M Buhr, M AF Moody, JL Davenport, JC Merrill, JT Oltmans, SJ Parrish, DD Holloway, JS Levy, H Forbes, GL Trainer, M Buhr, M TI Meteorological mechanisms for transporting O-3 over the western North Atlantic ocean: A case study for August 24-29, 1993 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC OZONE; TROPOPAUSE FOLDS; CARBON-MONOXIDE; EXCHANGE AB A large-scale view of O-3 transport over the western North Atlantic Ocean (WNAO) in summer illustrates distinct sources of O-3, and separate transport mechanisms are important at different vertical levels in the troposphere, The week-long period presented covers a sequence of O-3 sondes released from Bermuda and encompasses two surface O-3 events in the month-long NARE intensive. O-3 and CO peaked at Chebogue Point on the evening of August 25 and after midnight. on the morning of August 28. At Sable Island, peaks occurred during early morning of August 26 and late morning of August 28. These events occurred under W-SW winds associated with advancing low-pressure systems that transported anthropogenic pollutants over the WNAO. The concentrations dropped with the passage of a trough or a cold front. Evidence suggests the surface was occasionally isolated from polluted air during favorable transport with pollutants lifted in warm sector flow riding over a wedge of cool, thermodynamically stable air, In addition to surface O-3, the O-3-sonde profile over Bermuda on the morning of August 27 showed a deep layer of O-3 from 6 to 12 km. Using back trajectories and two tracers (isentropic potential vorticity and water vapor), we illustrate that stratospheric ozone exchanged into the upper troposphere in conjunction with surface cyclogenesis was advected through the middle to upper troposphere over the midlatitudes with the potential to reach lower altitudes through subsidence in regions of anticyclonic motion. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. ATMOSPHER ENVIRONM SERV, DOWNSVIEW, ON M3H 5T4, CANADA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. UNIV RHODE ISL, GRAD SCH OCEANOG, CTR ATMOSPHER CHEM STUDIES, NARRAGANSETT, RI 02882 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP Moody, JL (reprint author), UNIV VIRGINIA, DEPT ENVIRONM SCI, CLARK HALL, CHARLOTTESVILLE, VA 22903 USA. RI Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013 OI Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; NR 23 TC 35 Z9 35 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 DEC 20 PY 1996 VL 101 IS D22 BP 29213 EP 29227 DI 10.1029/96JD00885 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800048 ER PT J AU Draxler, RR AF Draxler, RR TI Boundary layer isentropic and kinematic trajectories during the August 1993 North Atlantic Regional Experiment Intensive SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; BACK TRAJECTORIES; SOUTH-ATLANTIC; CHEMISTRY; OZONE; AIR; TROPOSPHERE; ENGLAND; HAWAII; ORIGIN AB Four per day backward trajectories were computed from Chebogue Point, Nova Scotia, for the month of August 1993 using two different three-dimensional approaches: diagnostic vertical velocity fields (kinematic) and an isentropic assumption. Essentially, 90% of all the kinematic-isentropic trajectory pairs were displaced within +/- 75 hPa of each other and differed in the horizontal by about 10% of the travel distance. The greatest vertical displacement differences occurred with flow from the northwest and only three time periods were associated with the greatest displacements; a cyclonic system was to the north of the trajectory starting location in each case. Precipitation was associated with two of these events. A moist isentropic departure was computed for both kinematic and isentropic cases and departures were typically about 5 degrees K. Comparison of CO measurements and upwind trajectories suggested by temporal groupings of trajectories were consistent with transport from major urban areas. However, the peak measured CO values seemed to occur more frequently with flow transition periods, when trajectory uncertainty is the greatest. RP Draxler, RR (reprint author), NOAA, AIR RESOURCES LAB, 1315 EAST WEST HIGHWAY, SILVER SPRING, MD 20910 USA. NR 35 TC 46 Z9 49 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 DEC 20 PY 1996 VL 101 IS D22 BP 29255 EP 29268 DI 10.1029/95JD03760 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800051 ER PT J AU Kasibhatla, P Levy, H Klonecki, A Chameides, WL AF Kasibhatla, P Levy, H Klonecki, A Chameides, WL TI Three-dimensional view of the large-scale tropospheric ozone distribution over the North Atlantic Ocean during summer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; SEASONAL-VARIATION; SURFACE OZONE; GLOBAL MODEL; ATMOSPHERE; TRANSPORT; EMISSIONS; AMERICA; NOX; CIRCULATION AB A global chemical transport model is used to study the three-dimensional structure of the tropospheric ozone (O-3) distribution over the North Atlantic Ocean during summer. A simplified representation of summertime O-3 photochemistry appropriate for northern hemisphere midlatitudes is included in the model. The model is evaluated by comparing simulated O-3 mixing ratios to summertime O-3 measurements taken in and near the North Atlantic Ocean basin. The model successfully reproduces (1) the means and standard deviations of ozonesonde measurements over North America at 500 mbar; (2) the statistical characteristics of surface O-3 data at Sable Island off the coast of North America and at Bermuda in the western North Atlantic; and (3) the mean midtropospheric O-3,O- measured at Bermuda and also at the Azores in the eastern North Atlantic. The model underestimates surface O-3 in the eastern North Atlantic, overestimates O-3 in the lower free troposphere over the western North Atlantic, and also has difficulty simulating the upper tropospheric ozonesonde measurements over North America. An examination of the mean summertime O-3 distribution simulated by the model shows a significant continental influence on boundary layer and free-tropospheric O-3 over the western North Atlantic. The model has also been exercised using a preindustrial NOx emission scenario. By comparing the present-day and preindustrial simulations, we conclude that anthropogenic NOx emissions have significantly perturbed tropospheric O-3 levels over most of the North Atlantic. We estimate that present-day O-3 levels in the lower troposphere over the North Atlantic are at least twice as high as corresponding preindustrial O-3 levels. We find that the anthropogenic impact is substantial even in the midtroposphere, where modeled present-day O-3 mixing ratios are at least 1.5 times higher than preindustrial O-3 levels. C1 GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08542 USA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RI Kasibhatla, Prasad/A-2574-2010; OI Kasibhatla, Prasad/0000-0003-3562-3737 NR 62 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1996 VL 101 IS D22 BP 29305 EP 29316 DI 10.1029/95JD03234 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800054 ER PT J AU Flatoy, F Hov, O Gerbig, C Oltmans, SJ AF Flatoy, F Hov, O Gerbig, C Oltmans, SJ TI Model studies of the meteorology and chemical composition of the troposphere over the North Atlantic during August 18-30, 1993 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; ACID DEPOSITION; OXIDANT MODEL; OZONE; TRANSPORT; AMERICA; EUROPE AB A mesoscale chemistry transport model driven by meteorological data from a numerical weather prediction model is used to calculate ozone, carbon monoxide, oxides of nitrogen, and other chemical species over the North Atlantic for a 13-days period (August 18-30, 1993). The model has a circumpolar grid so that the boundary condition problems are minimized, and the influence of North American emissions on the chemical composition of the troposphere over the North Atlantic and Europe is calculated. During the first part of the period there is a zonal flow across the North Atlantic in the free troposphere; later, there is a strong north-south as well as vertical component in the advection field. The variability in the concentrations of ozone in the free troposphere is mainly caused by dynamical processes, while the chemical modification is small over an integration time of less than two weeks. A continental plume off the North American continent extending 2000 km or more into the North Atlantic is identified toward the end of the calculation period. There is then a maximum in the concentration of ozone around 1 km above the sea surface, with a much lower concentration in the marine boundary layer close to the ocean surface. Measurements from the U.K. Meteorological Office Hercules C-130 in the free troposphere off the Atlantic Provinces, across the Atlantic Ocean, and around the Azores together with ozone soundings from the Azores, Bermuda, and Iceland were used for model comparison. The calculations indicate that in the free troposphere the initial conditions as well as the upper boundary conditions are important for ozone distribution. In the upper troposphere the net change in the chemical formation rate of ozone due to a change in the NOx concentration is quite independent of the absolute value of the ozone concentration itself and, consequently, the choice of boundary conditions for ozone is not so important in this context, In the lower troposphere the change in the net chemical formation rate of ozone, which follows from a change in the concentration of NOx, shows a marked dependence on the concentration of ozone. C1 FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST CHEM & DYNAM GEOSPHARE, D-52425 JULICH, GERMANY. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP UNIV BERGEN, INST GEOPHYS, ALLEGATEN 70, N-5007 BERGEN, NORWAY. RI Gerbig, Christoph/L-3532-2013 OI Gerbig, Christoph/0000-0002-1112-8603 NR 35 TC 15 Z9 15 U1 0 U2 3 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 DEC 20 PY 1996 VL 101 IS D22 BP 29317 EP 29334 DI 10.1029/96JD01227 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ788 UT WOS:A1996VZ78800055 ER PT J AU Peter, T Murphy, DM AF Peter, T Murphy, DM TI Airborne particle analysis - Response SO SCIENCE LA English DT Letter C1 NOAA,AERON LAB,BOULDER,CO 80303. RP Peter, T (reprint author), MAX PLANCK INST CHEM,D-55020 MAINZ,GERMANY. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 20 PY 1996 VL 274 IS 5295 BP 1996 EP 1997 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VY974 UT WOS:A1996VY97400010 ER PT J AU Johnson, RD Hudgens, JW AF Johnson, RD Hudgens, JW TI Structural and thermochemical properties of hydroxymethyl (CH2OH) radicals and cations derived from observations of (B)over-tilde (2)A'(3p)<-(X)over-tilde (2)A'' electronic spectra and from ab initio calculations SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID MULTIPHOTON IONIZATION SPECTROSCOPY; BOND-DISSOCIATION ENERGIES; IONIZED METHYL ACETATE; GAS-PHASE; PHOTOELECTRON-SPECTROSCOPY; PROTONATED FORMALDEHYDE; VIBRATIONAL FREQUENCIES; TEMPERATURE-DEPENDENCE; HYDROGEN ABSTRACTION; REACTION-MECHANISM AB (B) over tilde(2)A'(3p) <-- (X) over tilde(2)A '' spectra of the isotopically substituted hydroxymethyl radicals (CH2OH, CH2OD, CD2OH, CD2OD) were observed between 39 700 and 43 000 cm(-1) by 2+1, 2+2, and 1+1 resonance-enhanced multiphoton ionization (REMPI) spectroscopy. Analyses of the vibrational hot bands in these spectra show that the nu(8) torsion modes and nu(9) CH2-wag mode are strongly coupled and governed by nonharmonic potential energy functions; for example, for (CH2OH)-C-12-O-16((X) over tilde(2)A '') we obtain 2 nu(8) = 846 +/- 6 cm(-1)(1 sigma), 1 nu(9) = 234 +/- 5 cm(-1), and 2 nu(9) = 615 +/- 6 cm(-1). Using MP2/6-311G(2df,2p) nb initio calculations, we constructed the two-dimensional potential energy surfaces that govern the nu(8) torsion modes and nu(9) CH2-wag in the (X) over tilde(2)A '' radical and the (X) over tilde(1)A' cation core of the (B) over tilde(2)A'(3p) Rydberg state. Energy levels calculated with these potential energy surfaces account for the REMPI bands originating from the nu(8) hindered rotor and the nu(9) CH2-wag modes. The experimental and nb initio results lead to improved heat capacities and entropies (S degrees(298.15)(CH2OH) = 244.170 +/- 0.018 J (mol K)(-1)). Ab initio CBS-QCI/APNO calculations predict that Delta(f)H degrees(298.15)(CH2OH) = -18.4 +/- 1.3 kJ mol(-1). Re-evaluation of photoionization data yields IPa(CH2OH) = 7.562 +/- 0.004 eV. Re-evaluated photoionization appearance data, kinetic equilibrium data, and shock tube data indicate that Delta(f)H degrees(0)(CH2OH+) = 718.1 +/- 1.8 kJ mol(-1), Delta(f)H degrees(298.15)(CH2OH+) = 716.4 +/- 1.8 kJ mol(-1), Delta(f)H degrees(0)(CH2OH) = -11.5 +/- 1.3 kJ mol(-1), and Delta(f)H degrees(298.15)(CH2OH+) = -17.8 +/- 1.3 kJ mol(-1), We report the proton affinity, PA(0)(CH2O) = 705.2 +/- 1.9 kJ mol(-1). Thermochemical tables based upon these values are presented for CH2OH and CH2OH+. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. NR 154 TC 98 Z9 99 U1 2 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 19 PY 1996 VL 100 IS 51 BP 19874 EP 19890 DI 10.1021/jp961399+ PG 17 WC Chemistry, Physical SC Chemistry GA VZ912 UT WOS:A1996VZ91200020 ER PT J AU Opansky, BJ Leone, SR AF Opansky, BJ Leone, SR TI Rate coefficients of C2H with C2H4, C2H6, and H-2 from 150 to 359 K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RATE-CONSTANT MEASUREMENTS; TEMPERATURE-DEPENDENCE; ABINITIO DETERMINATION; ACETYLENE; RADICALS; CH4; SPECTROSCOPY; TITAN; O-2; D2 AB Rate coefficients for the reactions C2H with C2H4, C2H6, and H-2 are measured over the temperature range 150-359 K using transient infrared laser absorption spectroscopy. The ethynyl radical is formed by photolysis of C2H2 with a pulsed excimer laser at 193 nm, and its transient absorption is monitored with a color center laser on the Q(11)(9) line of the A(2) Pi-X(2) Sigma transition at 3593.68 cm(-1). Over the experimental temperature range 150-359 K the rate constants of C2H with C2H4, C2H6, and H-2 can be fit to the Arrhenius expressions k(C2H4) = (7.8 +/- 0.6) x 10(-11) exp[(134 +/- 44)/T], k(C2H6) = (3.5 +/- 0.3) x 10(-11) exp[(2.9 +/- 16)/T], and k(H2) (1.2 +/- 0.3) x 10(-11) exp[(-998 +/- 57)]/T cm(3) molecule(-1) s(-1), respectively. The data for C2H with C2H4 and C2H6 indicate a negligible activation energy to product formation shown by the mild negative temperature dependence of both reactions. When the H-2 data are plotted together with the most recent high-temperature results from 295 to 854 K, a slight curvature is observed. The H-2 data can be fit to the non-Arrhenius form k(H2) = 9.2 x 10(-18)T(2.17+/-0.50)exp[(-478 +/- 165)/T] cm(3) molecules(-1) s(-1). The curvature in the Arrhenius plot is discussed in terms of both quantum mechanical tunneling of the 11 atom from H-2 to the C2H radical and bending mode contributions to the partition function. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 32 TC 63 Z9 63 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 19 PY 1996 VL 100 IS 51 BP 19904 EP 19910 DI 10.1021/jp9619604 PG 7 WC Chemistry, Physical SC Chemistry GA VZ912 UT WOS:A1996VZ91200023 ER PT J AU Lovejoy, ER Hanson, DR Huey, LG AF Lovejoy, ER Hanson, DR Huey, LG TI Kinetics and products of the gas-phase reaction of SO3 with water SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID SULFURIC-ACID; RATE-CONSTANT; TRIOXIDE; COMPLEX; H2SO4; H2O; SO3+H2O+M->H2SO4+M; MECHANISM; PARTICLES; CLUSTERS AB The kinetics of the gas-phase reactions of SO3 with H2O and D2O were studied over the temperature range 250-360 K in N-2 with a laminar flow reactor coupled to a chemical ionization mass spectrometer. The SO3 loss is second order in the water concentration, is independent of pressure (20-80 Torr N-2, 300 K), and has a strong negative temperature dependence and a significant H/D isotope effect (k(H2O) approximate to 2k(D2O)). The yield of sulfuric acid is 1.0 +/- 0.5 per SO3 consumed. These observations are consistent with the rapid association of SO3 and H2O to form the adduct H2OSO3 which reacts with water to produce sulfuric acid. The first-order rate coefficients for loss of SO3 by reaction with H2O and D2O are given by k(I)(s(-1)) = (2.26 +/- 0.85) x 10(-43)T exp((6544 +/- 106)/T)[H2O](2) and (9.45 +/- 2.68) x 10(-44)T exp((6573 +/- 82)/T)[D2O](2), where T = K and [H2O, D2O] molecule cm(-3). The errors are the uncertainty at the 95% confidence level for precision only. Analysis of the temperature dependence of the SO3 loss yields an upper limit for the H2O-SO3 bond enthalpy of 13 kcal mol(-1). C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Lovejoy, ER (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 30 TC 107 Z9 107 U1 2 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 19 PY 1996 VL 100 IS 51 BP 19911 EP 19916 DI 10.1021/jp962414d PG 6 WC Chemistry, Physical SC Chemistry GA VZ912 UT WOS:A1996VZ91200024 ER PT J AU Santodonato, LJ Neumann, DA Erwin, RW AF Santodonato, LJ Neumann, DA Erwin, RW TI Template mediated growth of rare earth carbides SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article RP Santodonato, LJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. OI Santodonato, Louis/0000-0002-4600-685X NR 11 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 18 PY 1996 VL 118 IS 50 BP 12860 EP 12861 DI 10.1021/ja9625788 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VY900 UT WOS:A1996VY90000058 ER PT J AU Amin, J Aust, JA Sanford, NA AF Amin, J Aust, JA Sanford, NA TI Z-propagating waveguide lasers in rare-earth-doped Ti:LiNbO3 SO APPLIED PHYSICS LETTERS LA English DT Article ID GUIDE AB A means of reproducibly fabricating stable cw lasers in rare-earth-doped Ti:LiNbO3 has been demonstrated through judicious choice of waveguide orientation. Z-propagating waveguides have been fabricated in Nd- and Er-diffused Ti:LiNbO3 and room-temperature laser operation with greatly reduced photorefractive instability has been obtained. The reduced photorefractive damage susceptibility in this waveguide configuration has led to the realization of a 980 nm pumped laser in Er:Ti:LiNbO3, with a threshold of 10.5 mW of absorbed pump power and a slope efficiency of 8.5%. (C) 1996 American Institute of Physics. RP Amin, J (reprint author), NATL INST STAND & TECHNOL,OPTOELECT MFG GRP,DIV 81504,325 BROADWAY,BOULDER,CO 80303, USA. NR 10 TC 84 Z9 84 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 16 PY 1996 VL 69 IS 25 BP 3785 EP 3787 DI 10.1063/1.116998 PG 3 WC Physics, Applied SC Physics GA VX975 UT WOS:A1996VX97500005 ER PT J AU Cross, RW Kim, YK Oti, JO Russek, SE AF Cross, RW Kim, YK Oti, JO Russek, SE TI Magnetostatic effects in giant magnetoresistive spin-valve SO APPLIED PHYSICS LETTERS LA English DT Article ID DEVICES AB We report on magnetotransport measurements of spin valve films that have been fabricated into rectangular stripes with Au current leads. The spin valve films consisted of two magnetic NiFe layers separated by a nonmagnetic Cu layer. The top NiFe layer was magnetically pinned by a FeMn layer with an effective pinning field of 12 kA/m (150 Oe). After device fabrication, the transport properties changed dramatically as the stripe-height of the device was decreased below 1 mu m. Internal demagnetizing fields and magnetostatic interactions between the magnetic layers dominated the magnetic response. These interactions change the biasing point and the linearity, and cause a decrease in sensitivity to field changes. We have developed a simple single-domain rotation model that includes magnetostatic, anisotropy, and exchange interactions to describe the magnetic behavior, from which we calculate the transport response. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP Cross, RW (reprint author), QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028, USA. NR 6 TC 31 Z9 32 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 16 PY 1996 VL 69 IS 25 BP 3935 EP 3937 DI 10.1063/1.117575 PG 3 WC Physics, Applied SC Physics GA VX975 UT WOS:A1996VX97500055 ER PT J AU Bezrukov, SM Vodyanoy, I Brutyan, RA Kasianowicz, JJ AF Bezrukov, SM Vodyanoy, I Brutyan, RA Kasianowicz, JJ TI Dynamics and free energy of polymers partitioning into a nanoscale pore SO MACROMOLECULES LA English DT Article ID PROBING ALAMETHICIN CHANNELS; WATER-SOLUBLE POLYMERS; SINGLE-ION CHANNEL; ALPHA-TOXIN; STAPHYLOCOCCUS-AUREUS; VOLUME CHANGES; PATCH-CLAMP; MEMBRANES; PROTEIN; DIFFUSION AB Membrane-bound proteinaceous nanoscale pores allow us to simultaneously observe the thermodynamic and kinetic properties of differently sized polymers within their confines. We determine the dynamic partitioning of poly(ethylene glycol) (PEG) into the pore formed by Staphylococcus aureus alpha-toxin and evaluate the free energy of polymer confinement by measuring polymer-induced changes to the pore's ionic conductance. The free energy deduced from the partition coefficient has a sharper dependence on polymer length (or weight) than scaling theory predicts. Moreover, the polymer-induced conductance fluctuations show a striking nonmonotonic dependence on the polymer molecular weight. The movement of polymer inside the pore is characterized by a diffusion coefficient that is orders of magnitude smaller than that for polymer in the bulk aqueous solution, which suggests that PEG has an attractive interaction with the pore. Using an ad-hoc approach,we show that a simple molecular weight-dependent modification of the polymer's diffusion coefficient accounts for these results, but only qualitatively. Given that PEG associates with hydrophobic regions in proteins, we also conclude that, contrary to the conventional view of ion channels, the aqueous cavity of the alpha-toxin pore's interior is, to some extent, hydrophobic. C1 ST PETERSBURG NUCL PHYS INST,GATCHINA 188350,RUSSIA. ONR EUROPE,LONDON NW1 5TH,ENGLAND. INST BIOTECHNOL,YEREVAN 375056,ARMENIA. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. RP Bezrukov, SM (reprint author), NIH,DIV COMP RES & TECHNOL,BETHESDA,MD 20892, USA. NR 44 TC 184 Z9 186 U1 2 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 16 PY 1996 VL 29 IS 26 BP 8517 EP 8522 DI 10.1021/ma960841j PG 6 WC Polymer Science SC Polymer Science GA VY915 UT WOS:A1996VY91500034 ER PT J AU Ensher, JR Jin, DS Matthews, MR Wieman, CE Cornell, EA AF Ensher, JR Jin, DS Matthews, MR Wieman, CE Cornell, EA TI Bose-Einstein condensation in a dilute gas: Measurement of energy and ground-state occupation SO PHYSICAL REVIEW LETTERS LA English DT Article ID SODIUM ATOMS; VAPOR AB We measure the ground-state occupation and energy of a dilute Bose gas of Rb-87 atoms as a function of temperature. The ground-state fraction shows good agreement with the predictions for an ideal Bose gas in a 3D harmonic potential. The measured transition temperature is 0.94(5)T-o, where T-o is the value for a noninteracting gas in the thermodynamic limit. We determine the energy from a model-independent analysis of the velocity distribution, after ballistic expansion, of the atom cloud. We observe a distinct change in slope of the energy-temperature curve near the transition, which indicates a sharp feature in the specific heat. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP Ensher, JR (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 25 TC 261 Z9 268 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 DEC 16 PY 1996 VL 77 IS 25 BP 4984 EP 4987 DI 10.1103/PhysRevLett.77.4984 PG 4 WC Physics, Multidisciplinary SC Physics GA VY111 UT WOS:A1996VY11100003 ER PT J AU Gawarkiewicz, GG Linder, CA Lynch, JF Newhall, AE Bisagni, JJ AF Gawarkiewicz, GG Linder, CA Lynch, JF Newhall, AE Bisagni, JJ TI A surface-trapped intrusion of slope water onto the continental shelf in the mid-Atlantic bight SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NEW-ENGLAND; SALINITY MAXIMUM; PYCNOCLINE; SOUTH; EXCHANGE; BREAK; RING; EDDY AB A high-resolution hydrographic transect across the shelfbreak south of Nantucket Shoals in August, 1995, revealed an unusual surface-trapped intrusion of saline Slope water onto the continental shelf. The intrusion was confined to the upper 25 m of the water column and penetrated 15 km shoreward of the 100-m isobath, the typical position of the shelfbreak front. The maximum salinity within the intrusion was 35.0. Several strong jets were present within the surface layer with maximum velocities between 0.30 and 0.44 m s(-1) the alongshelf direction. Satellite thermal imagery confirms the presence of a warm-core ring at the offshore edge of the section and shows a warm feature penetrating shoreward of the 100-m isobath. C1 WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,WOODS HOLE,MA 02543. WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,WOODS HOLE,MA 02543. WOODS HOLE OCEANOG INST,DEPT APPL OCEAN PHYS & ENGN,WOODS HOLE,MA 02543. RP Gawarkiewicz, GG (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,NARRAGANSETT,RI 02882, USA. NR 16 TC 8 Z9 8 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1996 VL 23 IS 25 BP 3763 EP 3766 DI 10.1029/96GL03427 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VY929 UT WOS:A1996VY92900023 ER PT J AU Weida, MJ Nesbitt, DJ AF Weida, MJ Nesbitt, DJ TI Geometric isomerism in clusters: High resolution infrared spectroscopy of a noncyclic CO2 trimer SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CARBON-DIOXIDE DIMER; ROTATIONAL SPECTRUM; ABSORPTION-SPECTROSCOPY; VIBRATIONAL FREQUENCIES; NITROUS-OXIDE; WATER TRIMER; DYNAMICS; COMPLEX; POTENTIALS; SCATTERING AB High resolution infrared spectra of a previously unidentified noncyclic isomer of (CO2)(3) have been obtained via direct absorption of a 4.3 mu m diode laser in a slit jet supersonic expansion. Two vibrational bands (labeled nu(I) and nu(III)) are observed, corresponding to the two most infrared active linear combinations of the three constituent CO2 monomer asymmetric stretches: nu(I) is redshifted -5.85 cm(-1) from the monomer vibrational origin and is predominately a c-type band of an. asymmetric top, while nu(III) is blueshifted +3.58 cm(-1) and is predominately an a-type band. Transitions with K-a + K-c = odd (even) in the ground (excited) state are explicitly absent from the spectra due to the zero nuclear spin of CO2; this rigorously establishes that the noncyclic isomer has a C-2 symmetry axis. The vibrational shifts and relative intensities of the bands are interpreted via a resonant dipole interaction model between the high-frequency stretches of the CO2 monomers. Rotational constants are determined by fits of transition frequencies to an asymmetric top Hamiltonian. These results are used to determine vibrationally averaged structural parameters for the complex, which is found to be stacked asymmetric but with C-2 symmetry about the b inertial axis. The structural parameters are then used to test several trial CO2-CO2 interaction potentials. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. RP Weida, MJ (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 53 TC 64 Z9 64 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1996 VL 105 IS 23 BP 10210 EP 10223 DI 10.1063/1.472930 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VX965 UT WOS:A1996VX96500005 ER PT J AU Hodges, JT Looney, JP vanZee, RD AF Hodges, JT Looney, JP vanZee, RD TI Response of a ring-down cavity to an arbitrary excitation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-ABSORPTION SPECTROSCOPY; MODES; LIGHT; HCN AB An eigenmode analysis of the response of an empty ring-down cavity to an arbitrary laser excitation is presented. By explicitly taking into account both the mode structure of the ring-down cavity and the spectral content of the laser pulse, it is found that the complicated ring-down signals commonly observed in the laboratory can be interpreted in terms of cavity mode beating. Some conclusions drawn from this analysis are verified experimentally by measurements of the time and frequency response of empty cavities. These observations provide clear evidence for the existence of longitudinal and transverse mode structures in ring-down cavities. RP Hodges, JT (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI Hodges, Joseph/B-4578-2009 NR 43 TC 88 Z9 88 U1 3 U2 25 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1996 VL 105 IS 23 BP 10278 EP 10288 DI 10.1063/1.472956 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VX965 UT WOS:A1996VX96500010 ER PT J AU deGouw, JA Ding, LN Krishnamurthy, M Lee, HS Anthony, EB Bierbaum, VM Leone, SR AF deGouw, JA Ding, LN Krishnamurthy, M Lee, HS Anthony, EB Bierbaum, VM Leone, SR TI The mobilities of NO+(CH3CN)(n) cluster ions (n=0-3) drifting in helium and in helium-acetonitrile mixtures SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID WIDE ENERGY-RANGE; TEMPERATURE-DEPENDENCE; TRANSPORT-PROPERTIES; GASEOUS-IONS; REACTIVITY; DIFFUSION; ATOMS; HE AB The mobilities of NO+(CH3CN)(n) cluster ions (n = 0-3) drifting in helium and in mixtures of helium and acetonitrile (CH3CN) are measured in a how-drift tube. The mobilities in helium decrease with cluster size [the mobility at zero held, K-0((0)), is 22.4 +/- 0.5 cm(2) V-1 s(-1) for NO+, 12.3 +/- 0.3 cm(2) V-1 s(-1) for NO+(CH3CN), 8.2 +/- 0.2 cm(2) V-1 s(-1) for NO+(CH3CN)2 and 7.5 +/- 0.5 cm(2) V-1 s(-1) for NO+(CH3CN)(3)] and depend only weakly on the characteristic parameter E/N (electric field strength divided by the number density of the buffer gas). The size dependence is explained in terms of the geometric cross sections of the different cluster ions. The rate constants for the various cluster formation and dissociation reactions have also been determined in order to rule out the possibility that reactions occurring in the drift region influence the measurements in the mixtures. Since high pressures of acetonitrile are required to form NO+(CH3CN)(2) and NO+(CH3CN)(3), the mobilities of these ions are found to be dependent on the acetonitrile concentration, as a result of anomalously small mobilities of these ions in acetonitrile [K-0((0)) = 0.041 +/- 0.004 cm(2) V-1 s(-1) for NO+(CH3CN)(2) and 0.044 +/- 0.004 cm(2) V-1 s(-1) for NO+(CH3CN)(3)]. These values are at least an order of magnitude smaller than any previously reported ion mobility, which can be partly explained by the large ion-permanent dipole interaction between the cluster ions and acetonitrile. The remaining discrepancies may be the result of momentum transfer outside the capture cross section, dipole-dipole interactions, ligand exchange, the formation of long-lived collision complexes or the transfer of kinetic energy into internal energy of the cluster ion and the acetonitrile molecule. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP deGouw, JA (reprint author), NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RI de Gouw, Joost/A-9675-2008 OI de Gouw, Joost/0000-0002-0385-1826 NR 35 TC 13 Z9 13 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1996 VL 105 IS 23 BP 10398 EP 10409 DI 10.1063/1.472968 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VX965 UT WOS:A1996VX96500020 ER PT J AU Mountain, RD AF Mountain, RD TI Dielectric constant of polarizable water at elevated temperatures SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; LIQUID WATER; PAIR POTENTIALS; CHARGE; MODEL AB The dielectric constant of a polarizable water model is estimated for several thermodynamic states at elevated temperatures and reduced densities relative to ambient conditions using molecular dynamics simulations. An extended Lagrangian formulation of induced polarization is used in these simulations in conjunction with thermostat variables. This approach to the simulation of induced polarization is found to require about one-half the computational effort needed to determine directly the adiabatic values for the induced dipole moments. As the temperature increases and the density decreases, the difference between the model and experimental values of the dielectric constant is positive and significantly larger than the uncertainty in the model values. RP Mountain, RD (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899, USA. NR 23 TC 21 Z9 21 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1996 VL 105 IS 23 BP 10496 EP 10499 DI 10.1063/1.472975 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VX965 UT WOS:A1996VX96500033 ER PT J AU Belkin, IM Levitus, S AF Belkin, IM Levitus, S TI Temporal variability of the subarctic front near the Charlie-Gibbs fracture zone SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTH-ATLANTIC CURRENT; INTERANNUAL VARIABILITY; MEDITERRANEAN WATER; FLEMISH CAP; OCEAN; CIRCULATION; AZORES; RIDGE AB We document temporal variability of the northernmost branch of the North Atlantic Current, known as the North Subarctic Front (NSAF), for the period 1976-1985. The front's location and temperature-salinity (T-S) parameters were determined from 120 repeat transects along three standard sections occupied by Russian ships: (1) ocean weather station (OWS) ''C'' (52.75 degrees N, 35.5 degrees W) to St. John's, Newfoundland; (2) along 35 degrees W, from 52 degrees N to 36.5 degrees N; and (3) OWS C to Cape St. Vincent, Portugal. The NSAF exhibits significant interannual variability of its location, shifting 200 km to 300 km in a few months. Along the OWS C-St. John's section, the front reached its southernmost location in 1976-1977, then experienced two 250-to-300-km northward shifts, in 1978-1979 and 1980-1981; all of the three shifts peaked in wintertime. These events nearly coincide with events of the opposite sign along the OWS C-Cape St. Vincent section (the northernmost location in 1976-1977 and two 200-km southward shifts, in 1978-1979 and 1980-1981). The NSAF's behavior is thus coherent near the Charlie-Gibbs Fracture Zone at the 500-km scale. Frontal time series (associated with the moving front) of T and S at the 200-m level for the cold side of the NSAF reveal two events: an S-200 minimum in the winter of 1976-1977, which might be a manifestation of the ''Great Salinity Anomaly'' of the 1970s, and a sharp drop of S-200 in early 1984, which might signal the arrival of another large salinity anomaly, the ''Great Salinity Anomaly'' of the 1980s. C1 RUSSIAN ACAD SCI,PP SHIRSHOV OCEANOL INST,MOSCOW,RUSSIA. RP Belkin, IM (reprint author), NOAA,OCEAN CLIMATE LAB,NATL OCEANOG DATA CTR,E OCS,1315 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 36 TC 34 Z9 34 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1996 VL 101 IS C12 BP 28317 EP 28324 DI 10.1029/96JC02794 PG 8 WC Oceanography SC Oceanography GA VY902 UT WOS:A1996VY90200001 ER PT J AU Clayson, CA Fairall, CW Curry, JA AF Clayson, CA Fairall, CW Curry, JA TI Evaluation of turbulent fluxes at the ocean surface using surface renewal theory SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; LATENT-HEAT FLUX; SEA-SURFACE; DRAG COEFFICIENT; BOUNDARY-LAYER; WIND-STRESS; CLOUD PROPERTIES; SENSIBLE HEAT; WATER-VAPOR; TOGA-COARE AB An internally consistent model is presented that can be used to determine the ocean surface fluxes of heat, moisture, and momentum, given bulk sea surface temperature and atmospheric temperature, humidity, and winds measured at a single level within the atmospheric surface layer. This model is based upon surface renewal theory as described by Brutsaert [1975a]. Liu et al. [1979] (hereinafter referred to as LKB) made partial use of this theory, and further improvements to the LKB parameterization have been made by Fairall et al. [1996a]. The present model includes the following improvements relative to the LKB and Fairall et al. bulk flux models: incorporation of a new time-scale parameterization for surface renewal, inclusion of capillary waves in the surface roughness model, derivation of the surface roughness scales of water vapor and heat based solely upon surface renewal theory; and incorporation of a new surface skin temperature model. The model is validated using shipborne observations of surface fluxes and surface meteorology that were obtained in the central Pacific Ocean, the western tropical Pacific, the subtropical Pacific, and the midlatitude North Atlantic. Comparisons of model results with covariance fluxes of latent heat show biases of less than 3% for all locations, with little dependence of error on wind speed; similar results are obtained for sensible heat and momentum flux. An assessment is given of the advantages of the present scheme over the LKB and Fairall et al. schemes. The model results are interpreted in the context of the physical processes involved in determining the surface roughness length and the surface renewal timescale. C1 UNIV COLORADO,PROGRAM ATMOSPHER & OCEAN SCI,BOULDER,CO 80302. NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. RP Clayson, CA (reprint author), PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,1397 CIVIL BLDG,W LAFAYETTE,IN 47907, USA. NR 60 TC 38 Z9 38 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1996 VL 101 IS C12 BP 28503 EP 28513 DI 10.1029/96JC02023 PG 11 WC Oceanography SC Oceanography GA VY902 UT WOS:A1996VY90200013 ER PT J AU Landrum, LL Gammon, RH Feely, RA Murphy, PP Kelly, KC Cosca, CE Weiss, RF AF Landrum, LL Gammon, RH Feely, RA Murphy, PP Kelly, KC Cosca, CE Weiss, RF TI North Pacific Ocean CO2 disequilibrium for spring through summer, 1985-1989 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CARBON-DIOXIDE; PARTIAL-PRESSURE; NITROUS-OXIDE; EXCHANGE; BUDGET; WATER; FLUX; VARIABILITY AB Extensive measurements of CO2 fugacity in the North Pacific surface ocean and overlying atmosphere during the years 1985-1989 are synthesized and interpreted to yield a basin-wide estimate of Delta fCO(2). The observations, taken from February through early September, suggest that the subtropical and subarctic North Pacific is a small sink for atmospheric CO2 (0.07 to 0.2 Gton C (half year)(-1) for the region north of 15 degrees N). Objective analysis techniques are used to estimate uncertainty fields resulting from constructing basin-wide contours of oceanic fCO(2) on the basis of individual cruise transects. The uncertainties are significant and imply that future sampling programs need to recognize that estimating oceanic uptake of anthropogenic CO2 from ship-transect observations of oceanic fCO(2) alone will require very extensive sampling. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. RP Landrum, LL (reprint author), UNIV WASHINGTON,SCH OCEANOG,BOX 357940,SEATTLE,WA 98195, USA. NR 42 TC 20 Z9 23 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1996 VL 101 IS C12 BP 28539 EP 28555 DI 10.1029/96JC02100 PG 17 WC Oceanography SC Oceanography GA VY902 UT WOS:A1996VY90200016 ER PT J AU Jorge, HG Ogren, JA AF Jorge, HG Ogren, JA TI Sensitivity of retrieved aerosol properties to assumptions in the inversion of spectral optical depths SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GREENHOUSE GASES; ATMOSPHERIC AEROSOLS; SIZE DISTRIBUTIONS; SULFATE AEROSOLS; SULFUR AEROSOLS; RELATIVE ROLES; EXTINCTION; CONSTANTS AB The uncertainties of integral aerosol properties calculated using aerosol size distributions retrieved from multiwavelength observations of aerosol optical depth have been determined for a variety of typical atmospheric aerosol size distributions and refractive indices. The results suggest that more information about the aerosol composition, as well as more information about the sizes that are less efficient, in the optical sense, is needed to improve the shape of the retrieved size distributions. All the calculations in this paper assume spherical homogeneous particles. The sensitivity results refer to these conditions. The moments of the retrieved size distributions are systematically underestimated and errors can be as large as -82%, -30%, and -35% for the total number of particles, the total surface, and the total volume, respectively. The errors in the mass scattering efficiency, the effective radius, and the total volume depend Very much on whether the actual volume size distribution is monomodal or bimodal. Fora known refractive index, the total scattering coefficient, the hemispherical backscattering coefficient, and the extinction coefficient, as well as the hemispheric backscattering to total scattering ratio and the asymmetry factor, are obtained with absolute Values for the average errors less than 4%. Similar behavior was expected for cases with uncertainty in the refractive index, especially for parameters defined by the ratio of two integral properties. However, it turns out that the hemispheric backscattering coefficient and the hemispheric backscattering to total scattering ratio were poorly retrieved, reaching errors of 29% in several cases, while the asymmetry factor was very well recovered with absolute values of the average errors always under 7%. When the wavelength dependence of the refractive index is included, the retrieved size distribution is very unrealistic, with average errors in the hemispheric backscattering coefficients and the hemispheric backscattering to total scattering ratio around 30% at some wavelengths. However, even in this case the errors in the retrieved asymmetry factor stay under 8%. Thus, for spherical and homogeneous particles, the spectral optical depth data can be used to determine the asymmetry factor with little sensitivity to the assumptions in the calculations. Furthermore, the retrieved size distribution can be used as an intermediate step to extrapolate one set of optical properties from another set of optical properties. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP Jorge, HG (reprint author), UNIV LA LAGUNA,DEPT FIS FUNDAMENTAL & EXPT,AVDA ASTROFIS FRANCISCO SANCHEZ,LA LAGUNA 38204,TENERIFE,SPAIN. RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 28 TC 18 Z9 18 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 15 PY 1996 VL 53 IS 24 BP 3669 EP 3683 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF057 UT WOS:A1996WF05700001 ER PT J AU Hoyle, RB McFadden, GB Davis, SH AF Hoyle, RB McFadden, GB Davis, SH TI Pattern selection with anisotropy during directional solidification SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID SURFACE-TENSION-ANISOTROPY; MORPHOLOGICAL STABILITY; BINARY ALLOY; PIVALIC ACID; GROWTH; INTERFACE; KINETICS AB The effects of surface-tension anisotropy on interface morphology during the directional solidification of a binary alloy are studied. The long-wave evolution equation derived by Brattkus & Davis to describe growth near the absolute stability limit is generalized to include the effects of a surface tension with cubic anisotropy. The special cases of growth in the [001], [011] and [111] directions are considered. The resulting evolution equations are derived, and amplitude equations governing roll/rectangle and roll/hexagon competition are obtained. The coefficients of the amplitude equations depend on the surface-tension anisotropy, and determine how pattern selection is influenced by the presence of geometrically preferred directions. Anisotropy leads to changes in the existence and stability criteria for each pattern, to imperfect bifurcations, and to loss of degeneracy in bifurcations. C1 NATL INST STAND & TECHNOL, COMP & APPL MATH LAB, GAITHERSBURG, MD 20899 USA. RP Hoyle, RB (reprint author), NORTHWESTERN UNIV, ROBERT R MCCORMICK SCH ENGN & APPL SCI, DEPT ENGN SCI & APPL MATH, EVANSTON, IL 60208 USA. RI McFadden, Geoffrey/A-7920-2008; Davis, Stephen /B-7344-2009 OI McFadden, Geoffrey/0000-0001-6723-2103; NR 30 TC 23 Z9 25 U1 0 U2 3 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 15 PY 1996 VL 354 IS 1721 BP 2915 EP 2949 DI 10.1098/rsta.1996.0135 PG 35 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VZ728 UT WOS:A1996VZ72800001 ER PT J AU Coakley, KJ AF Coakley, KJ TI Nonequilibrium kinetics of neutral atoms confined in a harmonic potential SO PHYSICA A LA English DT Article DE nonequilibrium kinetics; atomic collisions; s wave scattering; harmonic potential; Monte Carlo ID HYDROGEN AB The nonequilibrium behavior of neutral atoms confined in a harmonic potential is simulated by a Monte Carlo method. Atoms obey Maxwell-Boltzmann statistics. Initially, the probability distribution function (pdf) for each of the three energy components, E(x), E(y) and E(z), is taken to be a truncated exponential with cutoff E(c). Collisions between atoms are simulated assuming s wave scattering in the center-of-mass frame. Because the energy distributions in the three different dimensions were indistinguishable, all three energy components are assumed to have the same pdf. The time-varying pdf for the energy components is modeled as a mixture of two pdfs. Each of the two pdf's in the mixture is a truncated exponential; one applies to energies below the cutoff, the other pdf applies to energies above the cutoff. Each truncated exponential is characterized by a time-dependent decay parameter. A statistical model for the time-dependent decay parameters, and a mixture parameter, is developed. RP Coakley, KJ (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 15 PY 1996 VL 234 IS 1-2 BP 407 EP 426 DI 10.1016/S0378-4371(96)00272-5 PG 20 WC Physics, Multidisciplinary SC Physics GA WA080 UT WOS:A1996WA08000024 ER PT J AU WongNg, W Cook, LP AF WongNg, W Cook, LP TI Cation non-stoichiometry of the BaCuO2+x phase SO PHYSICA C LA English DT Article ID CU-O SUPERCONDUCTORS; SYSTEM; OXIDES AB This note presents evidence for cation non-stoichiometry of the BaCuO2 phase in samples prepared from starting materials with and without carbonate. Phase equilibrium experiments using polycrystalline samples as well as quantitative energy dispersive X-ray spectrometric analysis (EDS) of a BaCuO2 single crystal grown from a Ba-Cu-O melt were completed. Results showed this phase to be relatively copper rich with a nominal composition of Ba0.94Cu1.06O2+x. A brief literature review of the compositional and structural investigations of the BaCuO2 phase is also given. RP WongNg, W (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 33 TC 9 Z9 9 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 15 PY 1996 VL 273 IS 1-2 BP 135 EP 142 DI 10.1016/S0921-4534(96)00630-2 PG 8 WC Physics, Applied SC Physics GA WB635 UT WOS:A1996WB63500015 ER PT J AU Shirley, EL AF Shirley, EL TI Optimal basis sets for detailed Brillouin-zone integrations SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL-PROPERTIES; SPECIAL POINTS; BAND-GAPS; SEMICONDUCTORS; ELECTRON; INSULATORS; SYSTEMS; PSEUDOPOTENTIALS; ENERGIES; SILICON AB A method is given to obtain optimal basis sets for certain electronic-structure calculations, starting with solutions of Schrodinger's equation at a few crystal momenta and finding periodic functions that best span the periodic parts or such wave functions at all momenta. This is done within a pseudopotential, plane-wave framework. The derived basis sets should be most helpful for modeling quantities such as optical properties of materials: they have enables the author to solve Schrodinger's equation at thousands of crystal momenta from 4 to 3500 times faster than did a basis set of plane waves. However, one still obtains reasonable wave functions expanded in the same plane-wave representation. RP Shirley, EL (reprint author), NIST,OPT TECHNOL DIV,BLDG 221,ROOM B-208,GAITHERSBURG,MD 20899, USA. NR 36 TC 49 Z9 49 U1 0 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1996 VL 54 IS 23 BP 16464 EP 16469 DI 10.1103/PhysRevB.54.16464 PG 6 WC Physics, Condensed Matter SC Physics GA WA833 UT WOS:A1996WA83300041 ER PT J AU Kreider, KG Ruff, AW AF Kreider, KG Ruff, AW TI Materials for thin-film wear sensors SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 23rd International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 1996 CL SAN DIEGO, CA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div AB This paper addresses the problems of material selection and fabrication of sensors for steel bearings and reports test results for sliding ring and block tests (ASTM-G77). A thin-film wear sensor has been constructed to monitor the wear of a bearing surface while in contact with a shaft or flat counterface. The sensor consists of electrically conductive films separated from the bearing with insulating films. It monitors the regression of the surface due to wear in fractions of a micrometer over a small area. The effect of the materials and fabrication on the properties of the sensor are presented as they affect the electrical response and wear characteristics. The most critical properties of the insulating film are adhesion, low conductivity, strength, and hardness. Sputtered films of aluminum oxide, tantalum oxide, and borosilicate glass on 304 stainless steel substrates were evaluated. It was found that conductive films of copper and aluminum smeared excessively, but that films of platinum and tantalum could be used successfully for thin-him wear sensors as well as insulators of alumina and tantalum oxide. C1 NIST,DIV CERAM,GAITHERSBURG,MD 20899. RP Kreider, KG (reprint author), NIST,PROC MEASUREMENTS DIV,GAITHERSBURG,MD 20899, USA. NR 9 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 15 PY 1996 VL 86-7 IS 1-3 BP 557 EP 563 DI 10.1016/S0257-8972(96)02946-5 PN 2 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WC006 UT WOS:A1996WC00600018 ER PT J AU Qadri, SB Skelton, EF Lubitz, P Nguyen, NV Khan, HR AF Qadri, SB Skelton, EF Lubitz, P Nguyen, NV Khan, HR TI Electron beam deposition of ZrO2-ZnO films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 23rd International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 1996 CL SAN DIEGO, CA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div DE ellipsometry; X-ray fluorescence ID THIN-FILMS AB Thin films of zirconia-zincia (ZrO2-ZnO) have been produced by an electron beam evaporation technique. Two separate targets of ZrO2 and ZnO were used and a range of composition was selected from 10 to 60 wt.% of zinc. The final compositions of the deposited films were determined by X-ray fluorescence. Films deposited at 300 degrees C all crystallized in the cubic phase of ZrO2. The refractive indices of these films were measured by an ellipsometric technique. Preliminary electrical resistivity measurements as a function of temperature are also presented. C1 NATL INST STAND & TECHNOL, DIV SEMICOND ELECT, GAITHERSBURG, MD 20899 USA. FORSCHUNGSINST EDELMET & MET CHEM, D-73525 SCHWABISCH GMUND, GERMANY. RP USN, RES LAB, WASHINGTON, DC 20375 USA. NR 18 TC 17 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 15 PY 1996 VL 290 BP 80 EP 83 DI 10.1016/S0040-6090(96)09195-X PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WB819 UT WOS:A1996WB81900017 ER PT J AU Arp, U Cooper, JW LeBrun, T Southworth, SH Jung, M MacDonald, MA AF Arp, U Cooper, JW LeBrun, T Southworth, SH Jung, M MacDonald, MA TI Angular correlation between K alpha photons and L(2,3)-M(2,3)M(2,3) Auger electrons following argon 1s photoionization SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID ATOMS AB An analysis is presented of the angular correlation between KCL fluorescence photons and subsequently emitted L(2,3)-M(2,3)M(2,3) Auger electrons following K-shell ionization. The relative intensities of the Auger lines change in the coincidence experiment compared to the normal L(2,3)-M(2,3)M(2,3) Auger lines measured after direct 2p photoionization. A theoretical model is introduced to account for angular correlation effects and applied to reproduce experimental findings. C1 UNIV MARYLAND,INST SCI & TECHNOL,COLLEGE PK,MD 20742. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. EPSRC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Arp, U (reprint author), NATL INST STAND & TECHNOL,PHYS LAB,GAITHERSBURG,MD 20899, USA. RI Arp, Uwe/C-2854-2009 NR 11 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD DEC 14 PY 1996 VL 29 IS 23 BP L837 EP L842 DI 10.1088/0953-4075/29/23/005 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VZ708 UT WOS:A1996VZ70800005 ER PT J AU Biermann, S Hoeft, J Torring, T Mawhorter, R Lovas, FJ Suenram, RD Kawashima, Y Hirota, E AF Biermann, S Hoeft, J Torring, T Mawhorter, R Lovas, FJ Suenram, RD Kawashima, Y Hirota, E TI Microwave spectroscopy of mixed alkali halide dimers: LiNaF2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRIC-DIPOLE MOMENTS; DIFFRACTION; SPECTRUM; VAPORS AB Rotational spectra of (LiNaF2)-Li-6 and (LiNaF2)-Li-7 were measured by microwave absorption and Fourier-transform spectroscopy at different low rotational temperatures obtained by and adiabatic expansion in a beam and by collisional cooling in a cold absorption cell. Precise rotational constants, quartic centrifugal constants, quadrupole coupling constants, and the electric dipole moment were determined from least-squares fits of the experimental transition frequencies. Bond lengths and angles and the dipole moment are found to be in good agreement with recent ab initio calculations. As in homogeneous dimers, monomer to dimer bond expansions calculated from an ionic model are too large. The electric dipole moment from the ionic model is in excellent agreement with the ab initio result when experimental bond distances and angles are used and a 100% ionic character of the dimer bonds is assumed. (C) 1996 American Institute of Physics. C1 FREE UNIV BERLIN,INST PHYS EXPT,D-14195 BERLIN,GERMANY. POMONA COLL,DEPT PHYS & ASTRON,CLAREMONT,CA 91711. NIST,DIV OPT TECHNOL,GAITHERSBURG,MD 20899. KANAGAWA INST TECHNOL,DEPT CHEM TECHNOL,KANAGAWA 24302,JAPAN. GRAD UNIV ADV STUDIES,KANAGAWA 24001,JAPAN. NR 33 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 8 PY 1996 VL 105 IS 22 BP 9754 EP 9761 DI 10.1063/1.472831 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VW947 UT WOS:A1996VW94700005 ER PT J AU Maslen, PE Faeder, J Parson, R AF Maslen, PE Faeder, J Parson, R TI Ab initio calculations of the ground and excited states of I-2(-) and ICl- SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LEVEL-CORRELATED CALCULATIONS; MOLECULAR ELECTRIC PROPERTIES; POLARIZED BASIS-SETS; CHARGE-TRANSFER; PHOTODISSOCIATION; RECOMBINATION; ATOMS; IONS; I2 AB We performed all-electron ab initio calculations of the first six states of I-2(-) and ICl- using a multi-reference configuration interaction method. Spin-orbit coupling is included via an empirical one-electron operator and has a large effect on the dissociation energy. The ground state dissociation energies were in error by 20-30%, probably due to deficiencies in the one electron basis sets. The electronic wavefunctions at the equilibrium geometry were used to calculate the electronic absorption spectrum from the ground state, and good agreement was found with the experimental data. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 31 TC 48 Z9 48 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 6 PY 1996 VL 263 IS 1-2 BP 63 EP 72 DI 10.1016/S0009-2614(96)01162-1 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VW244 UT WOS:A1996VW24400010 ER PT J AU Ashfold, MNR Pearson, J Hudgens, JW Johnson, RD AF Ashfold, MNR Pearson, J Hudgens, JW Johnson, RD TI Resonance enhanced multiphoton ionisation of the SiF radical: A reinvestigation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RYDBERG-RYDBERG TRANSITIONS; IONIZATION SPECTROSCOPY; ELECTRONIC STATES; SILICON MONOFLUORIDE; MECHANISMS AB We report multiphoton ionisation spectra of ground (X(2) Pi) state SiF radicals, resonance enhanced at the two-photon energy by the v' = 1 level of the C ''(2) Sigma(+) excited state, at much higher resolution than hitherto. An earlier suggestion by Dulcey and Hudgens that the anomalous intensity of the C ''-X (1.0) two-photon transition might be attributable to additional, accidental, resonance enhancement at the one-photon energy by levels of the A(2) Sigma(+) v' = 0 state is confirmed, and the double resonance enhancement analysed in detail. A similar accidental double resonance enhancement, involving levels of the A(2) Sigma(+), v' = 1 state at the one-photon energy, is proposed to explain the observed fragmentary pattern of lines associated with the C'(2) Pi-X (5,0) two-photon transition. C1 NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP Ashfold, MNR (reprint author), UNIV BRISTOL,SCH CHEM,CANTOCKS CLOSE,BRISTOL BS8 1TS,AVON,ENGLAND. OI ashfold, michael/0000-0001-5762-7048 NR 28 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 6 PY 1996 VL 263 IS 1-2 BP 138 EP 144 DI 10.1016/S0009-2614(96)01153-0 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VW244 UT WOS:A1996VW24400021 ER PT J AU Koc, K Ishikawa, Y Kagawa, T Kim, YK AF Koc, K Ishikawa, Y Kagawa, T Kim, YK TI Relativistic modification of asymptotic configuration interaction in the carbon isoelectronic sequence SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-BASIS SETS; MANY-ELECTRON ATOMS; BREIT INTERACTION; IONS; ENERGIES; HELIUM; SYSTEMS; MERCURY AB Relativistic configuration interaction and many-body perturbation calculations have been performed on the J = 0 ground state of the carbon isoelectronic sequence up to Z = 106 (Z is nuclear charge) to establish quantitatively the way relativity alters the asymptotic configuration interaction. Although it is inappropriate to use relativistic many-body perturbation theory (RMBPT) based on a single-configuration reference state (1s(2)2s(2)2p(1/2)(2) J = 0) for low-Z members of the isoelectronic sequence due to strong mixing among several configuration states (i.e, quasi-degeneracy), the results of relativistic configuration interaction and many-body perturbation calculations demonstrate that RMBPT can be applied successfully to high-Z members in which strong mixing almost vanishes. C1 UNIV PUERTO RICO,DEPT CHEM,SAN JUAN,PR 00931. UNIV PUERTO RICO,CHEM PHYS PROGRAM,SAN JUAN,PR 00931. NARA WOMENS UNIV,DEPT PHYS,NARA 630,JAPAN. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Koc, K (reprint author), PEDAGOG UNIV,DEPT PHYS,UL PODCHORAZYCH 2,PL-30084 KRAKOW,POLAND. NR 27 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 6 PY 1996 VL 263 IS 1-2 BP 338 EP 344 DI 10.1016/S0009-2614(96)01174-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VW244 UT WOS:A1996VW24400053 ER PT J AU Overpeck, J Rind, D Lacis, A Healy, R AF Overpeck, J Rind, D Lacis, A Healy, R TI Possible role of dust-induced regional warming in abrupt climate change during the last glacial period SO NATURE LA English DT Article ID ICE CORE; NORTH-ATLANTIC; RECORD; SHEET; AEROSOLS; EVENTS; CYCLE; SEA AB RECORDS from loess, sediments and ice cores indicate that the concentrations of tropospheric aerosols were higher in glacial periods than they are today, and that they peaked just before glacial terminations(1-10). Energy-balance models have suggested(11-14) that these high glacial aerosol loadings were a source of glacial cooling of the order of 1-3 degrees C. Here we present a different view based on three-dimensional climate simulations, which suggest that high glacial dust loading may have caused significant, episodic regional warming of over 5 degrees C downwind of major Asian and ice-margin dust sources, Less warming was likely close to and over the oceans because of local cooling by seasalt and marine sulphate aerosols. Abrupt changes in dust loading are associated with the Dansgaard-Oeschger and Heinrich climate events and with glacial termination(3,8,15), suggesting that dust-induced warming may have played a role in triggering these large shifts in Pleistocene climate. C1 UNIV COLORADO, INST ARCTIC & ALPINE RES, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT GEOL SCI, BOULDER, CO 80309 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. COLUMBIA UNIV, CTR CLIMATE SYST RES, NEW YORK, NY 10027 USA. RP Overpeck, J (reprint author), NOAA, NATL GEOPHYS DATA CTR, PALEOCLIMATOL PROGRAM, 325 BROADWAY, E-GC, BOULDER, CO 80303 USA. RI Lacis, Andrew/D-4658-2012; Healy, Richard/J-9214-2015 OI Healy, Richard/0000-0002-5098-8921 NR 36 TC 77 Z9 79 U1 2 U2 24 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 5 PY 1996 VL 384 IS 6608 BP 447 EP 449 DI 10.1038/384447a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VW687 UT WOS:A1996VW68700057 ER PT J AU Fields, BA Goldbaum, FA DallAcqua, W Malchiodi, EL Cauerhff, A Schwarz, FP Ysern, X Poljak, RJ Mariuzza, RA AF Fields, BA Goldbaum, FA DallAcqua, W Malchiodi, EL Cauerhff, A Schwarz, FP Ysern, X Poljak, RJ Mariuzza, RA TI Hydrogen bonding and solvent structure in an antigen-antibody interface. Crystal structures and thermodynamic characterization of three Fv mutants complexed with lysozyme SO BIOCHEMISTRY LA English DT Article ID SITE-DIRECTED MUTAGENESIS; INFLUENZA-VIRUS NEURAMINIDASE; CROSS-REACTION COMPLEX; 3-DIMENSIONAL STRUCTURE; PROTEIN STABILITY; INHIBITOR COMPLEXES; BINDING; FAB; RESOLUTION; BARNASE AB Using site-directed mutagenesis, X-ray crystallography, and titration calorimetry, we have examined the structural and thermodynamic consequences of removing specific hydrogen bonds in an antigen-antibody interface. Crystal structures of three antibody FvD1.3 mutants, V(L)Tyr50Ser (V(L)Y50S), V(H)Tyr32Ala (V(H)Y32A), and V(H)Tyr101Phe (V(H)Y101F) bound to hen egg white lysozyme (HEL) have been determined at resolutions ranging from 1.85 to 2.10 Angstrom. In the wild-type (WT) FvD1.3-HEL complex, the hydroxyl groups of V(L)Tyr50, V(H)Tyr32, and V(H)Tyr101 each form at least one hydrogen bond with the lysozyme antigen. Thermodynamic parameters for antibody-antigen association have been measured using isothermal titration calorimetry, giving equilibrium binding constants K-b (M(-1)) of 2.6 x 10(7) (V(L)Y50S), 7.0 x 10(7) (V(H)Y32A), and 4.0 x 10(6) (V(H)Y101F). For the WT complex, K-b is 2.7 x 10(8) M(-1); thus, the affinities of the mutant Fv fragments for HEL are 10-, 4-, and 70-fold lower than that of the original antibody, respectively. In all three cases entropy compensation results in an affinity loss that would otherwise be larger. Comparison of the three mutant crystal structures with the WT structure demonstrates that the removal of direct antigen-antibody hydrogen bonds results in minimal shifts in the positions of the remaining protein atoms. These observations show that this complex is considerably tolerant, both structurally and thermodynamically, to the truncation of antibody side chains that form hydrogen bonds with the antigen. Alterations in interface solvent structure for two of the mutant complexes (V(L)Y50S and V(H)Y32A) appear to compensate for the unfavorable enthalpy changes when protein-protein interactions are removed. These changes in solvent structure, along with the increased mobility of side chains near the mutation site, probably contribute to the observed entropy compensation. For the V(H)Y101F complex, the nature of the large entropy compensation is not evident from a structural comparison of the WT and mutant complexes. Differences in the local structure and dynamics of the uncomplexed Fv molecules may account for the entropic discrepancy in this case. C1 UNIV MARYLAND,CTR ADV RES BIOTECHNOL,INST BIOTECHNOL,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,ROCKVILLE,MD 20850. UNIV BUENOS AIRES,FAC FARM & BIOQUIM,CONICET,CATEDRA INMUNOL,RA-1113 BUENOS AIRES,DF,ARGENTINA. US FDA,CTR DRUG EVALUAT & RES,ROCKVILLE,MD 20857. OI Malchiodi, Emilio/0000-0001-7501-3330 FU NIGMS NIH HHS [GM52801] NR 53 TC 40 Z9 40 U1 3 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 3 PY 1996 VL 35 IS 48 BP 15494 EP 15503 DI 10.1021/bi961709e PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VW439 UT WOS:A1996VW43900045 PM 8952503 ER PT J AU Monroe, C Meekhof, DM King, BE Leibfried, D Itano, WM Wineland, DJ AF Monroe, C Meekhof, DM King, BE Leibfried, D Itano, WM Wineland, DJ TI Manipulating the motion of a single trapped atom SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID QUANTUM; COMPUTATION; STATES; IONS RP Monroe, C (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. RI Monroe, Christopher/G-8105-2011 NR 25 TC 7 Z9 7 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD DEC PY 1996 VL 29 IS 12 BP 585 EP 590 DI 10.1021/ar950252i PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA VX891 UT WOS:A1996VX89100005 ER PT J AU Quinn, GD AF Quinn, GD TI ASTM C-28: The first decade SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Editorial Material RP Quinn, GD (reprint author), NIST,CHAIR C28,GAITHERSBURG,MD 20899, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD DEC PY 1996 VL 75 IS 12 BP 45 EP 46 PG 2 WC Materials Science, Ceramics SC Materials Science GA VY530 UT WOS:A1996VY53000002 ER PT J AU Jones, CA Lupi, F AF Jones, CA Lupi, F TI The effect of modeling substitute activities on recreational benefit estimates: Is more better? SO AMERICAN JOURNAL OF AGRICULTURAL ECONOMICS LA English DT Meeting Abstract C1 NOAA,WASHINGTON,DC. MICHIGAN STATE UNIV,E LANSING,MI 48824. RI Lupi, Frank/B-7865-2010 OI Lupi, Frank/0000-0003-2287-2259 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER AGRICULTURAL ECONOMICS ASSOC PI AMES PA 1110 BUCKEYE AVE, AMES, IA 50010-8063 SN 0002-9092 J9 AM J AGR ECON JI Am. J. Agr. Econ. PD DEC PY 1996 VL 78 IS 5 BP 1390 EP 1390 PG 1 WC Agricultural Economics & Policy; Economics SC Agriculture; Business & Economics GA WZ984 UT WOS:A1996WZ98400133 ER PT J AU Pursch, M Sander, LC Albert, K AF Pursch, M Sander, LC Albert, K TI Chain order and mobility of high-density C-18 phases by solid-state NMR spectroscopy and liquid chromatography SO ANALYTICAL CHEMISTRY LA English DT Article ID NEUTRON-SCATTERING; CROSS-POLARIZATION; STATIONARY-PHASE; BONDED PHASES; SILICA-GEL; SURFACE; PERFORMANCE; PACKINGS; MOTION; SI-29 AB C-18 phases prepared by different synthetic pathways are examined by solid-state NMR spectroscopy. Silane functionality is clearly indicated by Si-29 CP/MAS NMR spectroscopy. Order and mobility of the alkyl chains are investigated with high-speed H-1 MAS and C-13 CP/MAS NMR spectroscopy. Differences in coverage are monitored by H-1 line widths, C-13 chemical shifts, C-13 crosspolarization constants, and H-1 relaxation times in the rotating frame. It is shown that C-18 phases prepared by the surface polymerization technique exhibit a more regular surface coverage than sorbents prepared by conventional polymeric synthesis. The findings from solid-state NMR investigations are discussed in the context of liquid chromatography (LC) separations of linear and bulky polycyclic aromatic hydrocarbon (PAH) solutes. C1 UNIV TUBINGEN, INST ORGAN CHEM, D-72076 TUBINGEN, GERMANY. NATL INST STAND & TECHNOL, DIV ANALYT CHEM, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. NR 29 TC 112 Z9 112 U1 0 U2 4 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 DEC 1 PY 1996 VL 68 IS 23 BP 4107 EP 4113 DI 10.1021/ac9606113 PG 7 WC Chemistry, Analytical SC Chemistry GA VV333 UT WOS:A1996VV33300012 PM 21619319 ER PT J AU Roos, PA Stephens, M Wieman, CE AF Roos, PA Stephens, M Wieman, CE TI Laser vibrometer based on optical-feedback-induced frequency modulation of a single-mode laser diode SO APPLIED OPTICS LA English DT Article DE vibrometer; optical sensor; noncontact measurement; surface displacement ID INTERFEROMETER AB We describe a sensitive and inexpensive vibrometer based on optical feedback by diffuse scattering to a single-mode diode laser. Fluctuations in the diode laser's operating frequency that are due to scattered light from a vibrating surface are used to detect the amplitude and frequency of surface vibrations. An additional physical vibration of the laser provides an absolute amplitude calibration. The fundamental bandwidth is determined by the laser response time of roughly 10(-9) s. A noise floor of 0.23 nm/Hz(1/2) at 30 kHz with 5 x 10(-5) of the incident light returning is demonstrated. This instrument provides an inexpensive and sensitive method of noncontact measurement in solid materials with low or uneven reflectivity. It can be used as a vibration or velocity sensor. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP Roos, PA (reprint author), UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309, USA. NR 19 TC 69 Z9 80 U1 1 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 1996 VL 35 IS 34 BP 6754 EP 6761 DI 10.1364/AO.35.006754 PG 8 WC Optics SC Optics GA VV321 UT WOS:A1996VV32100019 PM 21151259 ER PT J AU Maloney, PR Begelman, MC Pringle, JE AF Maloney, PR Begelman, MC Pringle, JE TI Radiation-driven warping: The origin of warps and precession in accretion disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies, individual (NGC 4258); instabilities stars, individual (SS 433) ID ACTIVE GALAXIES; BLACK-HOLE; SS-433; NGC-4258 AB A geometrically thin, optically thick, warped accretion disk with a central source of luminosity is subject to nonaxisymmetric forces due to radiation pressure; the resulting torque acts to modify the warp. In a recent paper, J.E. Pringle used a local analysis to show that initially planar accretion disks are unstable to warping that is driven by radiation torque. Here we extend this work with a global analysis of the stable and unstable modes. We confirm Pringle's conclusion that thin, centrally illuminated accretion disks are generically unstable to warping via this mechanism; we discuss the time evolution and likely steady state of such systems, and show specifically that this mechanism can explain the warping of the disk of water masers in NGC 4258 and the 164 day precession period of the accretion disk in SS 433. Radiation-driven warping and precession provide a robust mechanism for producing warped, precessing accretion disks in active galactic nuclei and X-ray binary systems. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND. RP Maloney, PR (reprint author), UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,CAMPUS BOX 391,BOULDER,CO 80309, USA. NR 19 TC 127 Z9 127 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1996 VL 472 IS 2 BP 582 EP 587 DI 10.1086/178089 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW210 UT WOS:A1996VW21000015 ER PT J AU McGrattan, KB Baum, HR Rehm, RG AF McGrattan, KB Baum, HR Rehm, RG TI Numerical simulation of smoke plumes from large oil fires SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE buoyant plumes; crude oil; in situ burning; large eddy simulation ID DISPERSION; RISE AB A large eddy simulation (LES) model of smoke plumes generated by large outdoor pool fires is presented. The plume is described in terms of steady-state convective transport by a uniform ambient wind of heated gases and particulate matter introduced into a stably stratified atmosphere by a continuously burning fire. The Navier-Stokes equations in the Boussinesq approximation are solved numerically with a constant eddy viscosity representing dissipation on length scales below the resolution limits of the calculation. The effective Reynolds number is high enough to permit direct simulation of the large-scale mixing over two to three orders of magnitude in length scale. Particulate matter, or any non-reacting combustion product, is represented by Lagrangian particles which are advected by the fire-induced flow field. Background atmospheric motion is described in terms of the angular fluctuation of the prevailing wind, and represented by random perturbations to the mean particle paths. Results of the model are compared with two sets of field experiments. RP McGrattan, KB (reprint author), NATL INST STAND & TECHNOL,BLDG 224,ROOM A-345,GAITHERSBURG,MD 20899, USA. NR 17 TC 44 Z9 48 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1996 VL 30 IS 24 BP 4125 EP 4136 DI 10.1016/1352-2310(96)00151-3 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VK842 UT WOS:A1996VK84200003 ER PT J AU Glen, WG Zelenka, MP Graham, RC AF Glen, WG Zelenka, MP Graham, RC TI Relating meteorological variables and trends in motor vehicle emissions to monthly urban carbon monoxide concentrations SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE carbon monoxide; meteorology; emissions; trends; motor vehicles; mixing height ID AIR AB A model which quantifies the relationship between the monthly time series for CO emissions, the monthly time Series in ambient CO concentration, and meteorologically driven dispersion was developed. Fifteen cities representing a wide range of geographical and climatic conditions were selected. An eight-year time series (1984-1991 inclusive) of monthly averaged data were examined in each city. A new method of handling missing ambient concentration values which is designed to calculate city-wide average concentrations that follow the trend seen at individual monitor sites is presented. This method is general and can be used in other applications involving missing data. The model uses emissions estimates along with two meteorological variables (wind speed and mixing height) to estimate monthly averages of ambient air pollution concentrations. The model is shown to have a wide range of applicability; it works equally well for a wide range of cities that have very different temporal CO distributions. The model is suited for assessing long-term trends in ambient air pollutants and can also be used for estimating seasonal variations in concentration, estimation of trends in emissions, and for filling in gaps in the ambient concentration record. Copyright (C) 1996 Elsevier Science Ltd C1 MANTECH ENVIRONM TECHNOL INC,RES TRIANGLE PK,NC 27709. NOAA,AIR RESOURCES LAB MD56,RES TRIANGLE PK,NC 27711. NR 14 TC 26 Z9 28 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1996 VL 30 IS 24 BP 4225 EP 4232 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VK842 UT WOS:A1996VK84200012 ER PT J AU Tobias, DJ Mar, W Blasie, JK Klein, ML AF Tobias, DJ Mar, W Blasie, JK Klein, ML TI Molecular dynamics simulations of a protein on hydrophobic and hydrophilic surfaces SO BIOPHYSICAL JOURNAL LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; X-RAY-DIFFRACTION; LIPID MULTILAYER FILMS; CYTOCHROME-C; POTENTIAL FUNCTIONS; MEMBRANE; PROFILE; SYSTEM; MODEL; GOLD AB Molecular dynamics simulations have been used to investigate the behavior of the peripheral membrane protein, cytochrome c, covalently tethered to hydrophobic (methyl-terminated) and hydrophilic (thiol-terminated) self-assembled monolayers (SAMs). The simulations predict that the protein will undergo minor structural changes when it is tethered to either surface, and the structures differ qualitatively on the two surfaces: the protein is less spherical on the hydrophilic SAM where the polar surface residues reach out to interact with the SAM surface. The protein is completely excluded from the hydrophobic SAM but partially dissolves in the hydrophilic SAM. Consequently, the surface of the thiol-terminated SAM is considerably less ordered than that of the methyl-terminated SAM, although a comparable, high degree of order is maintained in the bulk of both SAMs: the chains exhibit collective tilts in the nearest-neighbor direction at angles of 20 degrees and 17 degrees with respect to the surface normal in the hydrophobic and the hydrophilic SAMs, respectively. On the hydrophobic SAM the protein is oriented so that the heme plane is more nearly parallel to the surface, whereas on the hydrophilic surface it is more nearly perpendicular. The secondary structure of the protein, dominated by alpha helices, is not significantly affected, but the structure of the loops as well as the helix packing is slightly modified by the surfaces. C1 UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104. NIST,DIV REACTOR RADIAT,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RI Tobias, Douglas/B-6799-2015 FU NIGMS NIH HHS [R01 GM33525, P32 GM14463, R01 GM40712] NR 29 TC 38 Z9 38 U1 2 U2 12 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD DEC PY 1996 VL 71 IS 6 BP 2933 EP 2941 PG 9 WC Biophysics SC Biophysics GA VX969 UT WOS:A1996VX96900005 PM 8968566 ER PT J AU Hicks, BB DeLuisi, JJ Matt, DR AF Hicks, BB DeLuisi, JJ Matt, DR TI The NOAA Integrated Surface Irradiance Study (ISIS) - A new surface radiation monitoring program SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID ATMOSPHERE SYSTEM; SOLAR-RADIATION; CLOUDS; CANOPIES; IMPACT; BUDGET AB This paper describes a new radiation monitoring program, the Integrated Surface Irradiance Study (ISIS), that builds upon and takes over from earlier NOAA networks monitoring components of solar radiation [both the visible component (SOLRAD) and the shortwave component that causes sunburn, UV-B] across the continental United States. ISIS is implemented in two levels. Level 1 addresses incoming radiation only, and level 2 addresses the surface radiation balance. Level 2 also constitutes the SURFRAD (Surface Radiation) program of the NOAA Office of Global Programs, specifically intended to provide radiation data to support large-scale hydrologic studies that will be conducted under the Global Energy and Water Cycle Experiment. Eventually, it is planned for level 2 sites to monitor all components of the surface energy balance. Both levels of ISIS will eventually measure both visible and UV radiation components. At present, there are nine sites that are considered to be at ISIS level 1 standard and an additional four level 2 SURFRAD sites. A 10th level 1 site will be in operation soon. Plans call for an increase in the number of sites of both kinds, up to about 15 ISIS sites, of which 6 will be at the SURFRAD level. Data are available via FTP at ftp.atdd.noaa.gov/pub/isis or at http://www.srrb.noaa.gov (level 2). C1 NOAA,AIR RESOURCES LAB,SURFAVE RADIAT RES BRANCH,BOULDER,CO 80303. NOAA,ATMOSPHER TURBULENCE & DIFFUS DIV,ARL,OAK RIDGE,TN. RP Hicks, BB (reprint author), NOAA,AIR RESOURCES LAB,ENVIRONM RES LAB,SSMC3 ROOM 3151,1315 E WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 20 TC 36 Z9 36 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1996 VL 77 IS 12 BP 2857 EP 2864 DI 10.1175/1520-0477(1996)077<2857:TNISIS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD699 UT WOS:A1996WD69900001 ER PT J AU Ebert, EE Manton, MJ Arkin, PA Allam, RJ Holpin, GE Gruber, A AF Ebert, EE Manton, MJ Arkin, PA Allam, RJ Holpin, GE Gruber, A TI Results from the GPCP algorithm intercomparison programme SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID CONVECTIVE RAINFALL; SCALE PRECIPITATION; TROPICAL RAINFALL; SATELLITE; CLOUD; IMAGERY AB Three algorithm intercomparison experiments have recently been conducted as part of the Global Precipitation Climatology Project with the goal of (a) assessing the skill of current satellite rainfall algorithms, (b) understanding the differences between them, and (c) moving toward improved algorithms. The results of these experiments are summarized and intercompared in this paper. It was found that the skill of satellite rainfall algorithms depends on the regime being analyzed, with algorithms producing very good results in the tropical western Pacific and over Japan and its surrounding waters during summer, but relatively poor rainfall estimates over western Europe during late winter. Monthly rainfall was estimated most accurately by algorithms using geostationary infrared data, but algorithms using polar data [Advanced Very High Resolution Radiometer and Special Sensor Microwave/Imager (SSM/I)] were also able to produce good monthly rainfall estimates when data from two satellites were available. In most cases, SSM/I algorithms showed significantly greater skill than IR-based algorithms in estimating instantaneous rain rates. C1 NATL CTR ENVIRONM PREDICT,WASHINGTON,DC. UK METEOROL OFF,BRACKNELL,BERKS,ENGLAND. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233. RP Ebert, EE (reprint author), BUR METEOROL RES CTR,GPO BOX 1289K,MELBOURNE,VIC 3001,AUSTRALIA. RI Arkin, Phillip/F-5808-2010 NR 28 TC 99 Z9 102 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1996 VL 77 IS 12 BP 2875 EP 2887 DI 10.1175/1520-0477(1996)077<2875:RFTGAI>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD699 UT WOS:A1996WD69900003 ER PT J AU FernandezPartagas, J Diaz, HF AF FernandezPartagas, J Diaz, HF TI Atlantic hurricanes in the second half of the nineteenth century SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB A historical revision of Atlantic tropical cyclones for the period 1851-90 is presented. This work was undertaken with the aim of improving knowledge of the tropical storms and hurricanes in the North Atlantic basin, which occurred during the latter half of the nineteenth century. Another aim of the study was to develop more reliable figures regarding cyclone frequency variations than those that were currently available. The 40-yr period covered by this study spans the 20 yr (1851-70) prior to the founding of a U.S. meteorological service as part of the U.S. Signal Service and the approximately 20 yr (1871-90) that military personnel of that service took care of the official meteorological affairs in the country, prior to the establishment of a civilian U.S. Weather Bureau within the U.S. Department of Agriculture. The period 1851-90 was found to be particularly attractive from a research standpoint because it covered the time elapsed from 1855, the last year included in the storm catalog prepared by Poey, which is used in the cyclone list shown by Tannehill, to 1878, the year the Signal Service began to systematically trace all West Indian hurricanes. A comparison of hurricane activity, in terms of the total number of storms, is made between the 40-yr period of 1851-90, and the corresponding period in the twentieth century. Even after taking into account the large differences in the observational network during these two periods, a century apart, there is some suggestion that the earlier period was relatively less active. C1 NOAA,ENVIRONM RES LAB,BOULDER,CO 80303. NR 27 TC 31 Z9 31 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1996 VL 77 IS 12 BP 2899 EP 2906 DI 10.1175/1520-0477(1996)077<2899:AHITSH>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD699 UT WOS:A1996WD69900005 ER PT J AU Cortinas, JV Straka, JM Beasley, WH Schneider, JM Machacek, CM AF Cortinas, JV Straka, JM Beasley, WH Schneider, JM Machacek, CM TI The Research Experiences for Undergraduates Program: The 1995 program at the Oklahoma Weather Center SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB The 1995 Research Experiences for Undergraduates program at the Oklahoma Weather Center introduced 14 students to the rigor of meteorological research, as well as provided them with information to help make informed career decisions. A unique portion of the summer program was the students' participation in the 1995 Verification of the Origins of Tornadoes Experiment, in which they collected data on convective storms. Participation in the program exposed students to the logistics of a major field program and taught them about tomadic storms. The program used a mentorship approach to teach the students how to conduct research. By working with a mentor, each student was exposed to the method of scientific research through direct interaction with a research scientist. An evaluation of the program found that it helped all students to develop confidence in their ability to do research and to be better educated about their career options. C1 COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK. UNIV OKLAHOMA,SCH METEOROL,NORMAN,OK 73019. RP Cortinas, JV (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1996 VL 77 IS 12 BP 2925 EP 2936 DI 10.1175/1520-0477(1996)077<2925:EA>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WD699 UT WOS:A1996WD69900008 ER PT J AU Morris, PA Domeier, M Stephens, J AF Morris, PA Domeier, M Stephens, J TI Notes on the occurrence and depth distribution of the bat ray in the Southern California Bight, with comments on the effect of trawl size on estimates of abundance SO CALIFORNIA FISH AND GAME LA English DT Article ID MYLIOBATIS-CALIFORNICA; ELKHORN SLOUGH RP Morris, PA (reprint author), NATL MARINE FISHERIES SERV,501 W OCEAN BLVD,SUITE 4470,LONG BEACH,CA 90802, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD WIN PY 1996 VL 82 IS 1 BP 48 EP 53 PG 6 WC Fisheries; Zoology SC Fisheries; Zoology GA VU975 UT WOS:A1996VU97500003 ER PT J AU Choi, KM Stansbury, JW AF Choi, KM Stansbury, JW TI New families of photocurable oligomeric fluoromonomers for use in dental composites SO CHEMISTRY OF MATERIALS LA English DT Article ID RESINS; POLYMERIZATION; FLUORINE; SHRINKAGE; MONOMERS AB Photopolymerizable methacrylate-based resins with moderate-to-high organofluorine contents may improve the hydrophobicity, durability, and toughness of composites used in aesthetic dental filling applications. A variety of multi-functional oligomeric fluorinated monomers were developed and evaluated with the goal of identifying polymer systems that combine high strength, low water sorption, and minimal polymerization shrinkage. Certain fluorooligomer resin compositions prepared here appear capable of successfully meeting these challenges. C1 NIST,DIV POLYMERS,DENT & MED MAT GRP,GAITHERSBURG,MD 20899. NR 27 TC 20 Z9 21 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD DEC PY 1996 VL 8 IS 12 BP 2704 EP & DI 10.1021/cm9603260 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VY243 UT WOS:A1996VY24300004 ER PT J AU Babushok, V Noto, T Burgess, DRF Hamins, A Tsang, W AF Babushok, V Noto, T Burgess, DRF Hamins, A Tsang, W TI Influence of CF3I, CF3Br, and CF3H on the high-temperature combustion of methane SO COMBUSTION AND FLAME LA English DT Article ID KINETIC DATA EVALUATION; OXYGEN-ARGON MIXTURES; ALKYL RADICALS CH3; ATMOSPHERIC CHEMISTRY; IUPAC SUBCOMMITTEE; PHOTOCHEMICAL DATA; SHOCK-WAVES; IGNITION; DISSOCIATION; I-C3H7 AB The effects of a number of flame retardants (CF3I, CF3Br, and CF3H) on the high-temperature reactions of methane with air in a plug flow reactor are studied by numerical simulations using the Sandia Chemkin Code.(1) The dependence of (a) the ignition delay and (b) time for substantially complete reaction as a function of temperature and additive concentrations are calculated. In agreement with experiments, the ignition delay can be increased or decreased by the addition of retardants. The reaction time is always increased by additives. The mechanism for these effects has been examined. It is concluded that the ignition delay is controlled by the initial retardant decomposition kinetics, which releases active species into the system. These species can either terminate or initiate chains. The reaction time is largely a function of the concentrations of the active radicals H, OH, and O that are formed during the combustion process. It is shown that their concentrations, particularly those of H atoms, are lowered in the presence of the retardants. We find that the chemical mechanism governing reaction time is very similar to that which controls the flame velocity and a correlation between decreases in flame velocity and H-atom concentration is demonstrated. The calculations suggest that relative reaction time and I-I-atom concentrations should be effective measures for the estimation of retardant effectiveness. Copyright (C) 1996 by The Combustion Institute C1 NIST,GAITHERSBURG,MD 20899. NR 72 TC 80 Z9 82 U1 2 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1996 VL 107 IS 4 BP 351 EP 367 DI 10.1016/S0010-2180(96)00052-1 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VU095 UT WOS:A1996VU09500003 ER PT J AU Shaddix, CR Smyth, KC AF Shaddix, CR Smyth, KC TI Laser-induced incandescence measurements of soot production in steady and flickering methane, propane, and ethylene diffusion flames SO COMBUSTION AND FLAME LA English DT Article ID VOLUME FRACTION; SURFACE GROWTH; SCATTERING; AIR; VISUALIZATION; FLUORESCENCE; DIAGNOSTICS; OXIDATION; PARTICLES; CARBON AB Quantitative experimental measurements of soot concentrations and soot scattering are presented for a series of steady and flickering coflowing methane, propane, and ethylene flames burning at atmospheric pressure. Flickering diffusion flames exhibit a wide range of time-dependent, vortex-flame sheet interactions, and thus they serve as an important testing ground for assessing the applicability of chemical models derived from steady flames. Acoustic forcing of the fuel flow rate is used to phase lock the periodic flame flicker close to the natural flame flicker frequency caused by buoyancy-induced instabilities. For conditions in which flame clip-off occurs, the peak soot concentrations in the methane flickering flames are 5.5 to 6 times larger than measured in a steady flame burning with the same mean fuel flow rate, whereas the enhancement for the flickering propane and ethylene flames is only 35 to 60%, independent of the flicker intensity. Soot concentration profiles and full Mie analysis of the soot volume fraction/scattering results reveal significant differences in the structure of the soot fields and in the roles of soot inception, growth, and oxidation for the different hydrocarbon fuels. The soot concentrations have been measured using laser-induced incandescence (LII). Since this is the only technique currently available for making time- and spatially-resolved soot concentration measurements in time-varying flow fields, considerable effort has been devoted to developing Ln for quantitative applications. Important considerations include (1) proper calibration measurements, (2) signal detection which minimizes interferences from C-2 Swan-band emission and broadband molecular fluorescence, (3) correction for the laser beam focus/spatial averaging effect In line image measurements, and (4) correction for LII signal extinction within the flame. Copyright (C) 1996 by The Combustion Institute RP Shaddix, CR (reprint author), NIST, BLDG & FIRE RES LAB, GAITHERSBURG, MD 20899 USA. NR 75 TC 177 Z9 182 U1 4 U2 33 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1996 VL 107 IS 4 BP 418 EP 452 DI 10.1016/S0010-2180(96)00107-1 PG 35 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VU095 UT WOS:A1996VU09500007 ER PT J AU Cavalli, AR Favreau, JP Phalippou, M AF Cavalli, AR Favreau, JP Phalippou, M TI Standardization of formal methods in conformance testing of communication protocols SO COMPUTER NETWORKS AND ISDN SYSTEMS LA English DT Article DE conformance testing; formal description techniques; testing theory; standardization AB This paper presents the work developed by the joint ISO/ITU-T working group on ''Formal Methods in Conformance Testing'' (FMCT) in order to obtain a future standard. It concerns several areas of conformance testing: terminology, testing concepts, test architecture, specification languages for tests and test generation methods, The influence of FMCT on testing methodology is also analysed and future trends in the area are addressed. C1 NIST, COMP SYST LAB, GAITHERSBURG, MD 20899 USA. FRANCE TELECOM, CNET, LAA, EIA, EVP, F-22301 LANNION, FRANCE. RP Cavalli, AR (reprint author), INST NATL TELECOMMUN, LES EPINETTES, 9 RUE CHARLES FOURIER, F-91011 EVRY, FRANCE. NR 32 TC 5 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7552 J9 COMPUT NETWORKS ISDN JI Comput. Netw. ISDN Syst. PD DEC PY 1996 VL 29 IS 1 BP 3 EP 14 DI 10.1016/S0169-7552(96)00015-3 PG 12 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA WD531 UT WOS:A1996WD53100002 ER PT J AU Ralls, K Demaster, DP Estes, JA AF Ralls, K Demaster, DP Estes, JA TI Developing a criterion for delisting the southern sea otter under the US endangered species act SO CONSERVATION BIOLOGY LA English DT Article ID POPULATION VIABILITY ANALYSIS; VALDEZ OIL-SPILL; EXXON-VALDEZ; RECOVERY PLANS; CONSERVATION AB Recent surveys of recovery plans indicate that criteria, such as population sizes, for delisting species from the U.S. Endangered Species Act (ESA) are often unrealistically low by scientific standards. We describe the delisting criterion for the threatened southern sea otter (Enhydra lutris nereis) developed by the Southern Sea Otter Recovery Team. A major oil spill is the most serious threat to this sea otter population. After extensive modeling of oil spills, the recovery team concluded that it was not scientifically defensible to develop a delisting criterion in terms of a single probability of extinction over a specified time period. Instead, the team decided to define a size at which it would consider the population endangered and to consider the population threatened as long as a major oil spill might reduce it to that size. The effective population size (N-e) for endangered status was set at 500, estimated to be about 1850 otters. Using a spill the size of the Exxon Valdez spill (250,000 bbl), the oil spill model was iterated to generate a frequency distribution of the number of sea otters contacted by oil, from which the team estimated that less than 800 otters would be killed by 90% of the simulated spills. Thus, the delisting criterion was set at 1850 + 800 = 2650 individuals. There have been several proposals to improve the Endangered Species Act by providing quantitative guidance, in the form of specific probabilities of extinction within some time frame or specific criteria like those used by the Wordl Conservation Union as to the levels of extinction risk represented by the terms ''threatened'' and ''endangered''. Experiences of the Sea Otter Recovery Team indicate that guidelines should not be overly rigid and should allow flexibility for dealing with specific situations. The most important consideration is to appoint a recovery team that is both technically well qualified and unconstrained by pressures from management agencies. C1 NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. UNIV CALIF SANTA CRUZ,INST MARINE SCI,NATL BIOL SERV,SANTA CRUZ,CA 95064. RP Ralls, K (reprint author), SMITHSONIAN INST,NATL ZOOL PK,WASHINGTON,DC 20008, USA. NR 34 TC 18 Z9 19 U1 3 U2 22 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD DEC PY 1996 VL 10 IS 6 BP 1528 EP 1537 DI 10.1046/j.1523-1739.1996.10061528.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA VY245 UT WOS:A1996VY24500007 ER PT J AU Hoff, HA Waytena, GL Vold, CL Suehle, JS Isaacson, IP Rebbert, ML Ma, DI Harris, K AF Hoff, HA Waytena, GL Vold, CL Suehle, JS Isaacson, IP Rebbert, ML Ma, DI Harris, K TI Ohmic contacts to semiconducting diamond using a Ti/Pt/Au trilayer metallization scheme SO DIAMOND AND RELATED MATERIALS LA English DT Article DE surface characterization; diffusion; electrical properties; diamond single crystals ID BORON-DOPED DIAMOND; SCHOTTKY DIODES; TI-AU; TRANSISTORS; FILMS AB Ohmic contacts have been fabricated on a naturally occurring type IIb diamond crystal using an annealed Ti/Pt/Au trilayer metallization where the Pt served successfully as a barrier to Ti diffusion into the Au capping layer. However, a specific contact resistance could not be reliably determined using transmission line model measurements. Auger microanalysis revealed the presence of Ti on the diamond surface near the ohmic contact pads. The most likely origin of the Ti on the diamond surface was determined to be lateral diffusion from beneath the contact pads. This would have produced a nonuniform concentration of Ti across the diamond surface which, in turn, would have affected the diamond sheet resistance in a complicated way. C1 USN, RES LAB, NANOELECT PROC FAC, WASHINGTON, DC 20375 USA. NIST, GAITHERSBURG, MD 20899 USA. HARRIS DIAMOND CORP, MT ARLINGTON, NJ 07865 USA. NR 22 TC 21 Z9 21 U1 1 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 EI 1879-0062 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD DEC PY 1996 VL 5 IS 12 BP 1450 EP 1456 DI 10.1016/S0925-9635(96)00566-3 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA WA143 UT WOS:A1996WA14300010 ER PT J AU Berger, JR Tewary, VK AF Berger, JR Tewary, VK TI Boundary element analysis of moire fields in anisotropic materials SO ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS LA English DT Article DE boundary element method; anisotropic solids; Green's functions; moire methods ID ELASTIC GREEN-FUNCTION; PARAMETERS; INTERFACE; CRACK AB A procedure for analyzing moire fringe patterns using boundary elements is presented. The kernels of the boundary integrals are based on anisotropic elastic Green's functions developed for bimaterial problems. The interfacial boundary conditions are incorporated in the Green's functions so the interface does not require discretization. The bimaterial kernels are also appropriate for homogeneous problems as well as degenerate isotropic problems. The moire fringe data provide full-field displacement information and are analyzed in a least-squares sense. The numerical procedure is shown to be a logical extension of the local collocation method developed for linear elastic fracture mechanics. An example is given to investigate convergence of the method, predictions of stress, and to investigate factors influencing the analysis. It is shown that moire fields associated with both displacement components are needed for an accurate analysis. (C) 1997 Elsevier Science Ltd. C1 NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. RP Berger, JR (reprint author), COLORADO SCH MINES,DIV ENGN,GOLDEN,CO 80401, USA. RI Berger, John/F-5169-2010 NR 24 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0955-7997 J9 ENG ANAL BOUND ELEM JI Eng. Anal. Bound. Elem. PD DEC PY 1996 VL 18 IS 4 BP 317 EP 325 DI 10.1016/S0955-7997(96)00038-0 PG 9 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA XH587 UT WOS:A1996XH58700008 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Diel patterns of behavior in juvenile walleye pollock, Theragra chalcogramma SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE fish behavior; vertical distribution; activity; schooling ID EASTERN BERING SEA; VERTICAL-DISTRIBUTION; FISH; FOOD; ABUNDANCE; ALASKA; LIGHT; FACILITATION; THERMOCLINES; PREDATOR AB In laboratory experiments, we contrasted the behavior of juvenile walleye pollock under dark and light conditions, comparing group cohesion, activity levels, vertical distribution, and movement into cold water when the water column was thermally stratified. At night the fish displayed a tendency for movement into the upper water column and were less active, with groups more dispersed than during the day. Time spent in cold water under stratified conditions did not differ between day and night. These results are interpreted relative to the potential ecological benefits and costs of particular behaviors, and their application in designing effective sampling surveys of juvenile abundances. RP Sogard, SM (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NEWPORT,OR 97365, USA. NR 35 TC 26 Z9 26 U1 1 U2 7 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 DEC PY 1996 VL 47 IS 4 BP 379 EP 386 DI 10.1007/BF00005051 PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VV176 UT WOS:A1996VV17600005 ER PT J AU Long, ER Robertson, A Wolfe, DA Hameedi, J Sloane, GM AF Long, ER Robertson, A Wolfe, DA Hameedi, J Sloane, GM TI Estimates of the spatial extent of sediment toxicity in major US estuaries SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID INFAUNAL COMMUNITY COMPOSITION; SAN-FRANCISCO BAY; QUALITY TRIAD; CONTAMINATION AB Acute laboratory toxicity tests were performed on surficial sediments collected from 1176 locations throughout 22 estuarine areas in the United States. Toxicity was determined with three standardized procedures: 10-day amphipod survival tests with solid-phase (bulk) sediments; 5-min microbial bioluminescence tests with organic solvent extracts of the sediments; and either 1-h sea urchin fertilization tests or 48-h mollusc embryo tests with the porewater of the sediments. Test results were weighted to the sizes (km(2)) of the geographic strata in which samples were collected. Selected bays and estuaries were sampled along the Atlantic and Gulf of Mexico coasts and in southern California along the Pacific coast of the United States. The individual survey areas ranged in size from <1.0 km(2) to over 550 km(2). Collectively, approximately 2532 km(2) were sampled in the 22 surveys. Toxicity was observed in the amphipod survival tests of bulk sediments in approximately 10.9% of the combined area. These data suggest that acute toxicity as measured with adult crustaceans was restricted to small portions of these urbanized estuaries, principally maritime harbors and industrialized bayous and waterways. Toxicity was much more pervasive in the tests of solvent extracts and 100% porewater, indicating that approximately 61% and 43%, respectively, of the combined areas sampled were toxic. The spatial extent of toxicity decreased to 11% and 5% in tests of 50% and 25% porewater, respectively. In most areas each test indicated different patterns in toxicity, and consequently, the concordance in estimates of toxicity among different tests was very small. Estimates of the spatial extent of toxicity probably would differ if tests were performed elsewhere and/or with different organisms. C1 NOAA,NIORCA 22,SILVER SPRING,MD 20910. FLORIDA DEPT ENVIRONM PROTECT,TALLAHASSEE,FL 32399. RP Long, ER (reprint author), NOAA,NIORCA 22,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 43 TC 91 Z9 96 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC PY 1996 VL 30 IS 12 BP 3585 EP 3592 DI 10.1021/es9602758 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VV205 UT WOS:A1996VV20500048 ER PT J AU Wolfe, DA Long, ER Thursby, GB AF Wolfe, DA Long, ER Thursby, GB TI Sediment toxicity in the Hudson-Raritan Estuary: Distribution and correlations with chemical contamination SO ESTUARIES LA English DT Article; Proceedings Paper CT Studies of the Hudson River Estuary Session of the 12th Biennial International-Estuarine-Research-Federation Conference CY 1993 CL HILTON HEAD ISL, SC SP Hudson River Fdn ID BAY AB The Hudson-Raritan Estuary is one of several United States coastal areas where chemical data have suggested a potential for contaminant-related biological effects, and multiyear intensive bioeffects surveys have been conducted by the National Oceanic and Atmospheric Administration. The severity and spatial patterns in sediment toxicity were determined in an estuary-wide survey during spring 1991 using amphipods, bivalve larvae, and luminescent bacteria as test organisms. Spatial patterns in toxicity corresponded to the distributions of a number of toxic chemicals in the sediments. Areas that exhibited the greatest sediment toxicity included the upper East River, Arthur Kill, Newark Bay, and Sandy Hook Bay. The lower Hudson River adjacent to Manhattan Island, upper New York Harbor, lower New York Harbor off Staten Island, and parts of western Raritan Bay generally showed lower toxicity. Supporting chemical analyses of the sediments, including acid-volatile sulfide and simultaneously-extracted metals, suggested that metals were generally not the cause of the observed toxicity, with the possible exception of mercury. Among all contaminants analyzed, toxicity was most strongly associated with polynuclear aromatic hydrocarbons, which were substantially more concentrated in toxic samples than in nontoxic samples, and which frequently exceeded sediment quality criteria. C1 NOAA,ORCA,BIOEFFECTS ASSESSMENT BRANCH,SEATTLE,WA 98115. SCI APPLICAT INT CORP,NARRAGANSETT,RI 02882. RP Wolfe, DA (reprint author), NOAA,ORCA,BIOEFFECTS ASSESSMENT BRANCH,SILVER SPRING,MD 20910, USA. NR 32 TC 30 Z9 30 U1 1 U2 10 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1996 VL 19 IS 4 BP 901 EP 912 DI 10.2307/1352306 PG 12 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WH233 UT WOS:A1996WH23300013 ER PT J AU Milinkovitch, MC LeDuc, RG Adachi, J Farnir, F Georges, M Hasegawa, M AF Milinkovitch, MC LeDuc, RG Adachi, J Farnir, F Georges, M Hasegawa, M TI Effects of character weighting and species sampling on phylogeny reconstruction: A case study based on DNA sequence data in cetaceans SO GENETICS LA English DT Article ID CYTOCHROME-B GENE; MITOCHONDRIAL-DNA; WHALES; BOOTSTRAP; EVOLUTION; TREE; CONFIDENCE; INFERENCE AB Different phylogenetic analyses of the same genetic data set can yield conflicting results, depending on the choice of parameter settings and included taxa. This is particularly true in studies involving data sets where levels of homoplasy are high and likely to obscure the phylogenetic signal. Filtering of this phylogenetic noise can be attempted, with varying degrees of success, by using different weighting schemes and ingroup/outgroup choices, but it can be difficult to decide objectively which approach is best. Using a cytochrome b data set from cetaceans and artiodactyls, we examined the effects of a suite of parameter settings on the outcome of phylogenetic analyses. We tested 2968 combinations among the seven parameters that most often vary among phylogenetic studies. It is our contention that this sensitivity analysis identifies portions of the multidimensional parameter space where phylogenetic signal is most reliably recovered, and simple rules are given to guide the choice of settings. Portions of this data set have been used in previous studies with conflicting results, namely the monophyly vs. paraphyly of one of the two major recognized cetacean suborders, the toothed whales. This analysis strongly supports the sister relationship between sperm whales and baleen whales. C1 UNIV LIEGE, DEPT GENET, B-4000 LIEGE, BELGIUM. SW FISHERIES SCI CTR, LA JOLLA, CA 92038 USA. INST STAT MATH, MINATO KU, TOKYO 106, JAPAN. RP Milinkovitch, MC (reprint author), FREE UNIV BRUSSELS, UNIT EVOLUT GENET,DEPT BIOL,ULB,CP 244, BD TRIOMPHE, B-1050 BRUSSELS, BELGIUM. NR 42 TC 75 Z9 81 U1 0 U2 4 PU GENETICS SOCIETY AMERICA PI BETHESDA PA 9650 ROCKVILLE AVE, BETHESDA, MD 20814 USA SN 0016-6731 EI 1943-2631 J9 GENETICS JI Genetics PD DEC PY 1996 VL 144 IS 4 BP 1817 EP 1833 PG 17 WC Genetics & Heredity SC Genetics & Heredity GA VY931 UT WOS:A1996VY93100046 PM 8978067 ER PT J AU Gruber, N Sarmiento, JL Stocker, TF AF Gruber, N Sarmiento, JL Stocker, TF TI An improved method for detecting anthropogenic CO2 in the oceans SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article; Proceedings Paper CT 1st Science Conference of the Global Analysis, Interpretation and Modelling Task Force CY SEP 24-29, 1995 CL GARMISCH PARTENKI, GERMANY ID TOTAL CARBON-DIOXIDE; NORTH-ATLANTIC OCEAN; POTENTIOMETRIC TITRATION; ISOPYCNAL SURFACES; CIRCULATION MODEL; REDFIELD RATIOS; ATMOSPHERIC CO2; PACIFIC-OCEAN; OXYGEN; DISTRIBUTIONS AB An improved method has been developed for the separation of the anthropogenic CO2 from the large natural background variability of dissolved inorganic carbon (C) in the ocean. This technique employs a new quasi-conservative carbon tracer Delta C*, which reflects the uptake of anthropogenic CO2 and the air-sea disequilibrium when a water parcel loses contact with the atmosphere. The air-sea disequilibrium component can be discriminated from the anthropogenic signal using either information about the water age or the distribution of Delta C* in regions not affected by the anthropogenic transient. This technique has been applied to data from the North Atlantic sampled during the Transient Tracers in the Ocean North Atlantic (TTO NAS) and Tropical Atlantic study (TTO TAS) cruises in 1981-1983. The highest anthropogenic CO2 concentrations and specific inventories (inventory per square meter) are found in the subtropical convergence zone. In the North Atlantic, anthropogenic CO2 has already invaded deeply into the interior of the ocean, north of 50 degrees N it has even reached the bottom, Only waters below 3000 m and south of 30 degrees N are not yet affected. We estimate an anthropogenic CO2 inventory of 20 +/- 4 Gt C in the North Atlantic between 10 degrees N and 80 degrees N. The 2.5-dimensional ocean circulation model of Stocker et al. [1994] and the three-dimensional ocean general circulation biogeochemistry model of Sarmiento et al. [1995] predict anthropogenic CO2 inventories of 18.7 Gt C and 18.4 Gt C, respectively, in good agreement with the observed inventory. Important differences exist on a more regional scale, associated with known deficiencies of the models. C1 PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. RP Gruber, N (reprint author), UNIV BERN,INST PHYS,SIDLERSTR 5,CH-3012 BERN,SWITZERLAND. RI Gruber, Nicolas/B-7013-2009; Stocker, Thomas/B-1273-2013 OI Gruber, Nicolas/0000-0002-2085-2310; NR 95 TC 288 Z9 292 U1 0 U2 51 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1996 VL 10 IS 4 BP 809 EP 837 DI 10.1029/96GB01608 PG 29 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA VV175 UT WOS:A1996VV17500018 ER PT J AU Serchuk, FM Kirkegaard, E Daan, N AF Serchuk, FM Kirkegaard, E Daan, N TI Status and trends of the major roundfish, flatfish, and pelagic fish stocks in the North Sea: Thirty-year overview SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on changes in the North Sea Ecosystem and Their Causes - Arhus 1975 Revisited CY JUL 11-14, 1995 CL AARHUS, DENMARK SP ICES DE cod; flatfish; haddock; herring; mackerel; management advice; North Sea; pelagic stocks; roundfish; saithe status and trends; stocks and fisheries AB Changes in the status of the major roundfish, flatfish, and pelagic stocks in the North Sea over the past 30 years are reviewed. Synopses are presented on trends in catches, fishing mortality, spawning-stock biomass, and recruitment for eight stocks (cod, haddock, whiting, saithe, plaice, sole, herring, and mackerel), together with an evaluation of the current state of these resources and the most resent management advice provided by the ICES Advisory, Committee on Fishery Management. (C) 1996 International Council for the Exploration of the Sea C1 DANISH INST FISHERIES RES,DK-2920 CHARLOTTENLUND,DENMARK. NETHERLANDS INST FISHERIES RES,RIVO,DLO,NL-1970 AB IJMUIDEN,NETHERLANDS. RP Serchuk, FM (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543, USA. NR 16 TC 20 Z9 21 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 1996 VL 53 IS 6 BP 1130 EP 1145 DI 10.1006/jmsc.1996.0139 PG 16 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA VZ689 UT WOS:A1996VZ68900031 ER PT J AU Milanovic, V Gaitan, M Marshall, JC Zaghloul, ME AF Milanovic, V Gaitan, M Marshall, JC Zaghloul, ME TI CMOS foundry implementation of Schottky diodes for RF detection SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article AB Schottky diodes for RF power measurement were designed and fabricated using a commercial n-well CMOS foundry process through the MOSIS(1) service. The Schottky diodes are implemented by modifying the SCMOS technology file of the public-domain graphics layout editor, MAGIC, or by explicitly implementing the appropriate CIF layers, The modifications allow direct contact of first-layer metal to the low-doped substrate, Current-voltage measurements showed that only the n-type devices had rectifying properties with a barrier height of 0.78 eV. The I-V results were verified by performing capacitance-voltage measurements on diodes of different contact-areas. The diodes were tested in an RF detector circuit, The cut off frequency of the detector was shown to be 600 MHz. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Milanovic, V (reprint author), GEORGE WASHINGTON UNIV,DEPT ELECT ENGN & COMP SCI,WASHINGTON,DC 20052, USA. NR 10 TC 36 Z9 39 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD DEC PY 1996 VL 43 IS 12 BP 2210 EP 2214 DI 10.1109/16.544393 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VU879 UT WOS:A1996VU87900022 ER PT J AU Lipe, TE AF Lipe, TE TI A reevaluation of the NIST low-frequency standards for AC-DC difference in the voltage range 0.6-100 V SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB A reevaluation of the NIST standards of ac-dc difference was undertaken in an effort to reduce the calibration uncertainty offered by NIST for thermal voltage converters (TVC's) at frequencies below 100 Hz. This paper describes the measurements taken in support of this effort, as well as the devices used for the reevaluation process and the analysis of the uncertainty of the measurements. This reevaluation of the NIST low-frequency standards will permit a significant reduction in uncertainty for ac-dc difference calibrations at 10 Hz in the voltage range from 0.6-100 V. RP Lipe, TE (reprint author), NIST,DIV ELECT,ELECT & ELECT ENGN LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 1996 VL 45 IS 6 BP 913 EP 917 DI 10.1109/19.543985 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA VU291 UT WOS:A1996VU29100001 ER PT J AU Witczak, SC Schrimpf, RD Galloway, KF Fleetwood, DM Pease, RL Puhl, JM Schmidt, DM Combs, WE Suehle, JS AF Witczak, SC Schrimpf, RD Galloway, KF Fleetwood, DM Pease, RL Puhl, JM Schmidt, DM Combs, WE Suehle, JS TI Accelerated tests for simulating low dose rate gain degradation of lateral and substrate pnp bipolar junction transistors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 33rd Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 15-19, 1996 CL RENAISSANCE ESMERALD CONFERENCE RESORT, INDIAN WELLS, CA SP IEEE NPSS, Def Nucl Agcy, Sandia Natl Labs, Phillips Labs, NASA, Goddard Space Flight Lab, Jet Prop Lab HO RENAISSANCE ESMERALD CONFERENCE RESORT ID LINEAR INTEGRATED-CIRCUITS; HARDNESS-ASSURANCE AB The effect of dose rate on radiation-induced current gain degradation at 20 krad(Si) was quantified for lateral and substrate pnp bipolar transistors over the range of 0.001 to 294 rad(Si)/s. Degradation increases monotonically with decreasing dose rate, such that, at an emitter-to-base voltage of 0.7 V, radiation-induced excess base current differs by a factor of approximately, eight at the extreme dose rates. Degradation shows little dependence on dose rate below 0.005 rad(Si)/s, suggesting that further degradation enhancement at space-like dose rates may be negligible. In addition, the effect of ambient temperature on radiation-induced gain degradation at 294 rad(Si)/s was thoroughly investigated over the range of 25 to 240 degrees C. Degradation is enhanced with increasing temperature while simultaneously being moderated by in situ annealing such that, for a given total dose, an optimum irradiation temperature for maximum degradation results. Optimum irradiation temperature decreases logarithmically with total dose and is larger and more sensitive to dose in the substrate device than in the lateral device. Based on the measurement of midgap interface trap density in the base oxide, enhancement in transistor gain degradation due to elevated temperature is explained as an increase in surface recombination velocity in the base. Maximum high dose rate degradation at elevated temperature closely approaches low dose rate degradation for both devices. Based on high-temperature irradiations, a flexible procedure for the accelerated prediction of low dose rate gain degradation at 20 krad(Si) is developed for each of the devices studied. C1 SANDIA NATL LABS,DEPT 1332,ALBUQUERQUE,NM 87185. RLP RES INC,ALBUQUERQUE,NM 87185. NIST,IONIZING RADIAT DIV,GAITHERSBURG,MD 20899. USN,CTR SURFACE WARFARE,DEPT ADV TECHNOL,CRANE,IN 47522. NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899. RP Witczak, SC (reprint author), UNIV ARIZONA,DEPT ELECT & COMP ENGN,TUCSON,AZ 85721, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 26 TC 55 Z9 67 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1996 VL 43 IS 6 BP 3151 EP 3160 DI 10.1109/23.556919 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA WC903 UT WOS:A1996WC90300091 ER PT J AU Cresswell, MW Sniegowski, JJ Ghoshtagore, RN Allen, RA Guthrie, WF Gurnell, AW Linholm, LW Dixson, RG Teague, EC AF Cresswell, MW Sniegowski, JJ Ghoshtagore, RN Allen, RA Guthrie, WF Gurnell, AW Linholm, LW Dixson, RG Teague, EC TI Recent developments in electrical linewidth and overlay metrology for integrated circuit fabrication processes SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article; Proceedings Paper CT 9th International MicroProcess Conference (MPC 96) CY JUL 08-11, 1996 CL KITAKYUSHU INTERNATIONAL CONFERENCE CENTER, KITAKYUSHU, JAPAN SP Japan Soc Appl Phys, Amer Vacuum Soc, Inst Elect Electr Engineers Electron Device Soc, Inst Elect Engineers Japan, Inst Electr Informat Commun Engineers, Japan Soc Electron Microscope, Japan Soc Synchrotron Radiat Res, Surface Sci Japan, Kitakyushu Convention Bur HO KITAKYUSHU INTERNATIONAL CONFERENCE CENTER DE integrated circuit; fabrication; calibration; linewidth; overlay; metrology; lithography; SIMOX; standards ID SILICON AB Electrical linewidth measurements have been extracted from test structures replicated in planar films of monocrystalline silicon that were electrically insulated from the bulk-silicon substrate by a layer of silicon dioxide formed by separation by the implantation of oxygen (SIMOX) processing. Appropriate selection of the surface orientation of the starting material, the design and orientation of the structure's features, and patterning by a lattice-plane selective etch provide features with planar, atomically smooth sidewalls and rectangular cross sections. The primary motivation for this approach is to attempt to overcome the serious challenge posed by methods divergence to the certification of linewidth reference-materials for critical-dimension (CD) instrument calibration and related tasks. To enhance the physical robustness of reference features with deep submicrometer linewidths, the new test structure embodies short reference-segment lengths and arbitrarily wide voltage taps. Facilities for reconciliation of measurements extracted from the same feature by all normally practiced techniques are also implemented. In overlay metrology, electrical inspection of two types of hybrid overlay targets allows pixel calibration of, and shift extraction from, the overlay instruments. The overall strategic focus of this research is to resolve methods-divergence issues and possibly to develop universal deep-submicrometer linewidth reference materials for CD instruments and techniques for instrument- and process-specific shift extraction for optical overlay metrology. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. BIORAD MICROMEASUREMENTS INC,MT VIEW,CA 94043. RP Cresswell, MW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 23 TC 17 Z9 17 U1 0 U2 2 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD DEC PY 1996 VL 35 IS 12B BP 6597 EP 6609 DI 10.1143/JJAP.35.6597 PG 13 WC Physics, Applied SC Physics GA WF480 UT WOS:A1996WF48000049 ER PT J AU Johnson, W AF Johnson, W TI Selection rules for point-defect anelastic relaxations: Classical versus quantum mechanical SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 11th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS 11) CY JUL 07-11, 1996 CL ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE, POITIERS, FRANCE HO ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE AB A quantum mechanical analysis of selection rules for point-defect relaxations under an applied stress yields different results than a conventional classical analysis. The difference in the two approaches is illustrated using a simple 4-well model. The classical selection rules are a special case of the quantum mechanical selection rules with the wavefunctions of the reorienting defect atoms highly localized in potential minima, such that off-diagonal matrix elements of the stress perturbation are negligible. RP Johnson, W (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 1996 VL 6 IS C8 BP 27 EP 30 DI 10.1051/jp4:1996803 PG 4 WC Physics, Multidisciplinary SC Physics GA WM772 UT WOS:A1996WM77200004 ER PT J AU Ledbetter, H Sizova, N Kim, S Kobayashi, H Sgobba, S Parrini, L AF Ledbetter, H Sizova, N Kim, S Kobayashi, H Sgobba, S Parrini, L TI Internal friction and creep-recovery in indium SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 11th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS 11) CY JUL 07-11, 1996 CL ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE, POITIERS, FRANCE HO ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE AB Using low-stress pseudoshear deformation, we measured the ambient-temperature creep-recovery behavior of polycrystalline indium. The epsilon-sigma diagram shows three regions with increasing stress: stress exponents of 1.05, 7.4, and 2.0. The diagram resembles remarkably the dislocation-velocity-shear-stress diagrams reported for various materials by many authors, who interpreted the diagrams by dislocation dynamics. Applying an extended Burgers model (two Kelvin-Voigt elements) gave for the three regions the following relaxation times tau(2) and tau(3) (in seconds): (1) 11, 123; (2) 10, 132; (3) 12, 154. Thus, tau(1) is nearly stress independent, and tau(2) increases with increasing stress. Laplacean transformation of our epsilon(t) measurements to get the retardation-time distribution function g(In tau) indicates in all three regions a strong peak near tau(2)=3 s and a weaker, broader peak near tau(3)=150 s. These agree surprisingly well with the Burgers dashpot-spring-model results. We analyzed the recovery part of the strain epsilon(t) to obtain Q(-1)(f) curves. C1 NATL RES LAB METROL,TSUKUBA,IBARAKI 305,JAPAN. CERN,GENEVA,SWITZERLAND. ECOLE POLYTECH FED LAUSANNE,INST GENIE ATOM,CH-1015 LAUSANNE,SWITZERLAND. RP Ledbetter, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 12 TC 3 Z9 3 U1 0 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 1996 VL 6 IS C8 BP 317 EP 319 DI 10.1051/jp4:1996869 PG 3 WC Physics, Multidisciplinary SC Physics GA WM772 UT WOS:A1996WM77200070 ER PT J AU Johnson, W AF Johnson, W TI Ultrasonic resonance of metallic spheres at elevated temperatures SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 11th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS 11) CY JUL 07-11, 1996 CL ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE, POITIERS, FRANCE HO ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE ID ELECTROMAGNETIC-ACOUSTIC TRANSDUCTION; SPECTROSCOPY AB A unique ultrasonic system has been constructed for measuring resonant frequencies and damping of metallic spheres at elevated temperatures. This system employs electromagnetic-acoustic transduction, with a solenoid coil surrounding the sphere in a uniform magnetic field. Temperature is measured with an optical pyrometer. Since the acoustic and temperature measurements are noncontacting, the uncertainties associated with external damping are relatively small. The resonant frequency and Q of the sample are determined by digital analysis of the ring-down following a single driving tone-burst. High-temperature measurements on pure polycrystalline aluminum are presented. RP Johnson, W (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 3 TC 5 Z9 5 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 1996 VL 6 IS C8 BP 849 EP 852 DI 10.1051/jp4:19968183 PG 4 WC Physics, Multidisciplinary SC Physics GA WM772 UT WOS:A1996WM77200184 ER PT J AU Ledbetter, H Dunn, M Kim, S AF Ledbetter, H Dunn, M Kim, S TI Internal friction and elastic constants of sintered titanium SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 11th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS 11) CY JUL 07-11, 1996 CL ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE, POITIERS, FRANCE HO ECOLE NATIONALE DE MECANIQUE ET AEROTECHNIQUE ID COMPOSITE AB Using a Marx-oscillator standing-wave resonance method, we measured the internal friction Q(-1) of sintered titanium containing up to 26 volume-percent voids (c). The surprising Q(-1)-versus-c curve shape, an exponential increase, lead us to remeasure Q(-1)-versus-c by acoustic-resonance spectroscopy, which gave similar results. We hypothesized that both void shape and void size change with c. For the void shape, we confirmed this hypothesis by measuring longitudinal and transverse sound velocities v(l) and v(t) and comparing them with Mori-Tanaka model predictions. As c increases from 0 to 0.26, effective void shape changes from near spherical to oblate spheroidal with an aspect ratio near 0.05. Optical microscopy confirmed the void-size change. We outline a model based on wave-scattering theory that explains the observed Q(-1)-c behavior. Increased particle size with increased c provides the dominant factor for the exponential Q(-1) increase. C1 UNIV COLORADO, DEPT MECH ENGN, CTR ACOUST MECH & MAT, BOULDER, CO 80309 USA. RP Ledbetter, H (reprint author), NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, BOULDER, CO 80303 USA. NR 8 TC 1 Z9 1 U1 2 U2 4 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 1996 VL 6 IS C8 BP 859 EP 862 DI 10.1051/jp4:19968185 PG 4 WC Physics, Multidisciplinary SC Physics GA WM772 UT WOS:A1996WM77200186 ER PT J AU Emenhiser, C Simunovic, N Sander, LC Schwartz, SJ AF Emenhiser, C Simunovic, N Sander, LC Schwartz, SJ TI Separation of geometrical carotenoid isomers in biological extracts using a polymeric C-30 column in reversed-phase liquid chromatography SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE carotenoids; geometrical isomers; C-30 column; biological extracts; HPLC ID TRANS-BETA-CAROTENE; ALL-TRANS; HUMAN PLASMA; HUMAN SERUM; STATIONARY-PHASE; HPLC SEPARATION; IN-VITRO; 9-CIS; 9-CIS-BETA-CAROTENE; ACCUMULATION AB Application of a polymeric C-30 reversed-phase (RP) liquid chromatography (LC) column for separations of geometrical carotenoid isomers extracted from biological sources is demonstrated. The relative retention characteristics of all-trans carotenoid standards on the C-30 column is also shown under isocratic conditions. Carotenoids were extracted from human serum, raw and thermally processed carrots, a Dunaliella algae-derived preparation of beta-carotene, and a poultry feed supplement containing marigold carotenoids. From extracts of plant and algal origin, geometrical isomers of beta-carotene (all-trans, 15-cis, 13-cis, and 9-cis), alpha-carotene (all-trans, 13-cis, 13'-cis, and g-cis), and lutein (all-trans, 13-cis, 13'-cis, 9-cis, and 9'-cis) were separated and tentatively identified, some of which were previously unresolved on other RPLC columns. Chromatography of serum carotenoid fractions resolved the prominent all-trans carotenoids and separated geometrical isomers of lutein, beta-carotene, and lycopene (11 cis-lycopenes). Absolute recoveries of alpha-carotene and beta-carotene from the C-30 column were 64 and 52% in the LC mobile phase and 89 and 88% when 0.1% (v/v) triethylamine (TEA) was added to the mobile phase, respectively. TEA-mediated enhancements in recovery of 21-55% were observed for several other carotenoids. C1 OHIO STATE UNIV,DEPT FOOD SCI & TECHNOL,COLUMBUS,OH 43210. N CAROLINA STATE UNIV,DEPT FOOD SCI,RALEIGH,NC 27695. NATL INST STAND & TECHNOL,DIV ANALYT CHEM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. OI Schwartz, Steven/0000-0002-1427-5780 NR 31 TC 98 Z9 106 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD DEC PY 1996 VL 44 IS 12 BP 3887 EP 3893 DI 10.1021/jf960104m PG 7 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA VZ010 UT WOS:A1996VZ01000033 ER PT J AU Bauer, S DeReggi, AS AF Bauer, S DeReggi, AS TI Pulsed electrothermal technique for measuring the thermal diffusivity of dielectric films on conducting substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRETS AB A simple technique for measuring the thermal diffusivity of dielectric films on thermally sinking substrates is proposed and demonstrated. It is an outgrowth of the thermal purse technique for measuring charge and polarization profiles. The thermal diffusivity is derived from the transient electrical response induced by a thermal pulse applied to a de voltage-biased sample. Because the response is proportional to the bias voltage, the signal-to-noise ratio is adjustable independently of the thermal pulse energy and may be made as large as required for determining the diffusivity with high precision. Measuring times of around 1 ms or shorter are sufficient for polymers with thicknesses up to 10 mu m. Experimental results for two different polyimide films spin coated on crystalline silicon substrates are presented and discussed. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI Bauer, Siegfried/A-2354-2009 NR 18 TC 20 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1996 VL 80 IS 11 BP 6124 EP 6128 DI 10.1063/1.363687 PG 5 WC Physics, Applied SC Physics GA VV267 UT WOS:A1996VV26700007 ER PT J AU Giacometti, JA DeReggi, AS Davis, GT Dickens, B Ferreira, GFL AF Giacometti, JA DeReggi, AS Davis, GT Dickens, B Ferreira, GFL TI Thermal pulse study of the electric polarization in a copolymer of vinylidene cyanide and vinyl acetate SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID 2ND-HARMONIC GENERATION; DIELECTRIC RELAXATIONS; AMORPHOUS COPOLYMER; POLYMERS; PIEZOELECTRICITY; BEHAVIOR; CHARGE; FIELD; LASER; GUIDE AB The polarization induced by thermopoling the alternating vinylidene cyanide/vinyl acetate copolymer has been studied by the thermal pulse technique. The mean polarization over the thickness and its spatial profile were determined as functions of the poling variables: electric field, time, and temperature. Additionally, the thermal stability of the polarization was studied between ambient temperature and the glass-transition temperature of 175 degrees C. The mean polarization was found to be proportional to the poling field up to the maximum field used of 42 MV/m and to be very stable up to 150 degrees C. The polarization profiles obtained after poling were found to be highly inhomogeneous, especially for short poling times, indicating positive charge injection from the positive electrode during poling. The polarization distribution continues to evolve after the mean polarization has reached a steady state indicating separate time scales for space-charge migration and dipole reorientation. (C) 1996 American Institute of Physics. C1 UNIV SAO PAULO, INST FIS SAO CARLOS, BR-13560250 SAO CARLOS, SP, BRAZIL. RP NIST, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. RI Giacometti, Jose Alberto/C-4634-2013 NR 36 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1996 VL 80 IS 11 BP 6407 EP 6415 DI 10.1063/1.363639 PG 9 WC Physics, Applied SC Physics GA VV267 UT WOS:A1996VV26700050 ER PT J AU Lu, YY Doviak, RJ Crisp, C AF Lu, YY Doviak, RJ Crisp, C TI Estimating large-scale vorticity using VAD products and reflectivity SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Velocity-azimuth display (VAD) products (i.e., wind, divergence, deformations, etc.) and a Lagrangian advective scheme applied to the reflectivity factor field are jointly used to estimate vertical profiles of vorticity. The reflectivity field is assumed to be conserved over the time period between radar observations. The vorticity selected gives the best least squares fit between observed and predicted reflectivity fields. These results suggest that vorticity is retrieved with a precision better than about 1 x 10(-5) s(-1) for scales on the order of 100 km and larger. The vorticity profiles are consistent with U.S. National Weather Service's analysis. The surface value of vorticity, extrapolated from the estimated profiles, is also compared with the vorticity calculated from Oklahoma mesonet data. The agreement is within the estimated standard error. C1 UNIV OKLAHOMA,CTR ANAL & PREDICT STORMS,NORMAN,OK 73019. NATL SEVERE STORMS LAB,NORMAN,OK 73069. NR 11 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1996 VL 13 IS 6 BP 1129 EP 1138 DI 10.1175/1520-0426(1996)013<1129:ELSVUV>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VX837 UT WOS:A1996VX83700001 ER PT J AU May, PT Adachi, T Tsuda, T Lataitis, RJ AF May, PT Adachi, T Tsuda, T Lataitis, RJ TI The spatial structure of RASS echoes SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ACOUSTIC SOUNDING SYSTEM; TROPOSPHERIC TEMPERATURE; MU RADAR; TURBULENCE; POWER AB An experiment to observe the spatial distribution of radio acoustic sounding system (RASS) echo intensity and Doppler shift using the MU radar is described. Various transmitting configurations are used to confirm that the RASS signal is focused onto a diffraction limited spot approximately the size of the transmitting antenna, except when a very small transmitting array is used where turbulence acting on the acoustic wave smears the spot. The signal fades away from the central spot with values about 6-10 dB lower in intensity next to the main spot. Significant gradients of Doppler shift across the radar antenna are seen in the lower height ranges. This may result in errors as large as a degree in the RASS virtual temperature estimates when large radar antennas and a single acoustic source are used. C1 KYOTO UNIV,CTR RADIO ATMOSPHER SCI,UJI,KYOTO,JAPAN. NOAA,ERL,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. RP May, PT (reprint author), BUR METEOROL RES CTR,GPO BOX 1289K,MELBOURNE,VIC 3001,AUSTRALIA. RI tsuda, toshitaka/A-3035-2015 NR 18 TC 6 Z9 6 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1996 VL 13 IS 6 BP 1275 EP 1284 DI 10.1175/1520-0426(1996)013<1275:TSSORE>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VX837 UT WOS:A1996VX83700011 ER PT J AU Stankov, BB Westwater, ER Gossard, EE AF Stankov, BB Westwater, ER Gossard, EE TI Use of wind profiler estimates of significant moisture gradients to improve humidity profile retrieval SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID COMBINED REMOTE SENSORS; WATER-VAPOR; MICROWAVE RADIOMETER; LIQUID WATER; RASS AB A method is presented to obtain a high-vertical-resolution humidity profile if the location and strength of only a few significant segments of the humidity gradient profile are known. The method is based on a previously developed statistical inversion technique coupled with moisture gradient information derived from wind profiler and the radiosonde temperature measurements. An existing retrieval algorithm uses an independent historical radiosonde-derived dataset and data from a two-channel microwave radiometer, standard surface meteorological instruments, and a lidar ceilometer. In this study, the possibility of constraining the statistical retrieval using measurements of significant moisture gradients derived from wind profiler signals and radiosonde temperature observations is investigated. An example is given to illustrate the method: an 26 May 1994 the 449-MHz wind profiler/RASS at Erie, Colorado, detected a strong humidity gradient at 4.9 km MSL. A statistical inversion algorithm constrained to the radar-measured gradient at 4.9 km was used to estimate the moisture profile. Results from this example show that an improvement in retrieved humidity profiles in particular, in the strength and location of a shallow layer, can be obtained if only significant radar-sensed humidity gradient information is added to other ground-based remote sensing measurements. C1 UNIV COLORADO,CIRES,BOULDER,CO 80309. RP Stankov, BB (reprint author), NOAA,ETL,R-E-ET4,325 BROADWAY,BOULDER,CO 80303, USA. NR 19 TC 18 Z9 19 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1996 VL 13 IS 6 BP 1285 EP 1290 DI 10.1175/1520-0426(1996)013<1285:UOWPEO>2.0.CO;2 PG 6 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VX837 UT WOS:A1996VX83700012 ER PT J AU Farrell, JT Nesbitt, DJ AF Farrell, JT Nesbitt, DJ TI Probing three-body intermolecular forces: Near-infrared spectroscopy of Ar2HF and Ar2DF van der Walls modes SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATION-TUNNELING SPECTROSCOPY; POTENTIAL-ENERGY SURFACE; AB-INITIO CALCULATIONS; NONADDITIVE INTERACTIONS; VIBRATIONAL DEPENDENCE; LASER SPECTROSCOPY; SMALL CLUSTERS; AR-HF; SPECTRA; TRIMERS AB Four intermolecular vibrational states of the weakly bound complexes Ar2HF and Ar2DF have been studied via high-resolution infrared spectroscopy. The vibrations are accessed as combination bands built on the v = 1 HF or DF intermolecular stretch. These van der Waals vibrational states correlate adiabatically with j = 1 motion of a hindered HF/DF rotor, corresponding to librational motion either in, or out of, the molecular plane. The vibrational origins of the Ar2HF in-plane and out-of-plane bends are 4008.9665(24) and 4035.174 41(86) cm(-1), respectively, which are 62.374 and 88.582 cm(-1) above the origin of the intermolecular ground state in the v(HF) = 1 manifold. For Ar2DF, the in-place and out-of-plane origins are 2939.836 63(4) and 2967.101 29(5) cm(-1), respectively, which correspond to intermolecular bending frequencies in the v(DF) = 1 manifold 44.852 and 72.117 cm(-1). Two dimensional angular calculations are presented which solve for the hindered rotor HF/DF eigenfunctions and eigenvalues on a pairwise additive potential constructed using a rigid Ar-2 framework; the predicted bending frequencies reproduce the correct energy ordering of the vibrational levels, but are systemically greater than experimentally observed. Rigorous full five-dimensional theoretical calculations of the intermolecular vibrational frequencies by Ernesti and Hutson [Phys. Rev. A 51 239 (1995)] in the full pairwise additive surface are found to be as much as 11% higher than the experimental values, indicating the presence of three-body repulsive contributions to the true angular potential. Inclusion of conventional three-body dispersion and induction terms can only account for a minority (approximate to 1/3) of the observed discrepancies. The majority (approximate to 2/3) of the vibrational shifts can be attributed to three-body ''exchange'' effects, i.e., the strongly anisotropic interaction of the HF/DF dipole with an exchange quadrupole formed by Ar-Ar. Inclusion of all three nonadditive terms (dispersion, induction, and exchange) improves the agreement with experiment by up to an order of magnitude. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,QUANTUM PHYS DIV,BOULDER,CO 80309. RP Farrell, JT (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 48 TC 20 Z9 20 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1996 VL 105 IS 21 BP 9421 EP 9440 DI 10.1063/1.472777 PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VV625 UT WOS:A1996VV62500004 ER PT J AU Philander, SGH Gu, D Halpern, D Lambert, G Lau, NC Li, T Pacanowski, RC AF Philander, SGH Gu, D Halpern, D Lambert, G Lau, NC Li, T Pacanowski, RC TI Why the ITCZ is mostly north of the equator SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; RADIATION BUDGET EXPERIMENT; STRATIFORM CLOUDINESS; SEASONAL CYCLE; PACIFIC-OCEAN; MODEL; EARTH; MAINTENANCE; CIRCULATION; VARIABILITY AB Although the distribution of sunshine is symmetrical about the equator, the earth's climate is not. Climatic asymmetries are prominent in the eastern tropical Pacific and Atlantic Oceans where the regions of maximum sea surface temperature, convective cloud cover, and rainfall are north of the equator. This is the result of two sets of factors: interactions between the ocean and atmosphere that are capable of converting symmetry into asymmetry, and the geometries of the continents that determine in which longitudes the interactions are effective and in which hemisphere the warmest waters and the intertropical convergence zone are located. The ocean-atmosphere interactions are most effective where the thermocline is shallow because the winds can readily affect sea surface temperatures in such regions. The thermocline happens to shoal in the eastern equatorial Pacific and Atlantic, but not in the eastern Indian Ocean, because easterly trade winds prevail over the tropical Atlantic and Pacific whereas monsoons, with a far larger meridional component, are dominant over the Indian Ocean. That is how the global distribution of the continents, by determining the large-scale wind patterns, causes climatic asymmetries to be prominent in some bands of longitude but not others. The explanation for asymmetries that favor the Northern rather than Southern Hemisphere with the warmest waters and the ITCZ involves the details of the local coastal geometries: the bulge of western Africa to the north of the Gulf of Guinea and the slope of the western coast of the Americas relative to meridians. Low-level stratus clouds over cold waters are crucial to the maintenance of the asymmetries. C1 CALTECH,JET PROP LAB,PASADENA,CA. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Philander, SGH (reprint author), PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08542, USA. NR 35 TC 268 Z9 281 U1 5 U2 57 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 2958 EP 2972 DI 10.1175/1520-0442(1996)009<2958:WTIIMN>2.0.CO;2 PN 1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF071 UT WOS:A1996WF07100003 ER PT J AU Li, TM Philander, SGH AF Li, TM Philander, SGH TI On the annual cycle of the eastern equatorial Pacific SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; TROPICAL PACIFIC; SEASONAL CYCLE; EL-NINO; OCEAN; MODEL; ATMOSPHERE; RELEVANCE; CHAOS; HEAT AB Although the sun ''crosses'' the equator twice a year, the eastern equatorial Pacific has a pronounced annual cycle, in sea surface temperature and in both components of the surface winds for example. (This is in contrast to the Indian Ocean and western Pacific where a semiannual oscillation of the zonal wind is the dominant signal on the equator.) Calculations with a relatively simple coupled ocean-atmosphere model indicate that the principal reason for this phenomenon is the marked asymmetry, relative to the equator, of the time-averaged climatic conditions in the eastern tropical Pacific. The important asymmetries are in surface winds, oceanic currents, and sea surface temperature: The time-averaged winds and currents have northward components at the equator and the warmest waters are north of the equator. Because of those asymmetries, seasonally varying solar radiation that is strictly antisymmetric relative to the equator can force a response that has a symmetric component. The amplitude of the resultant annual cycle at the equator depends on interactions between the ocean and atmosphere, and on positive feedbacks that involve low-level stratus clouds that form over cold surface waters. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. NR 27 TC 90 Z9 93 U1 4 U2 15 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 2986 EP 2998 DI 10.1175/1520-0442(1996)009<2986:OTACOT>2.0.CO;2 PN 1 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF071 UT WOS:A1996WF07100005 ER PT J AU Kessler, WS Spillane, MC McPhaden, MJ Harrison, DE AF Kessler, WS Spillane, MC McPhaden, MJ Harrison, DE TI Scales of variability in the equatorial Pacific inferred from the tropical atmosphere-ocean buoy array SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; NORTH PACIFIC; ROSSBY-WAVE; LEVEL; INTERPOLATION; ATLANTIC; NETWORK; DESIGN; CYCLE; SPACE AB The highly temporally resolved time series from the Tropical Atmosphere-Ocean moored buoy array are used to evaluate the scales of thermal variability in the upper equatorial Pacific. The TAO array consists of nearly 70 deep-ocean moorings arranged nominally 15 degrees longitude and 2 degrees-3 degrees latitude apart across the equatorial Pacific. The bulk of the data from the array consists of daily averages telemetered in real time, with some records up to 15 years long. However, at several sites more finely resolved data exist, in some cases with resolution of 1 minute. These data form the basis for spectral decomposition spanning virtually all scales of variability from the Brunt-Vaisala frequency to the El Nino-Southern Oscillation timescale. The spectra are used to define the signal to noise ratio as a function of sample rate and frequency, and to investigate the effects of aliasing that results from sparser sampling, such as ship-based observational techniques. The results show that the signal to noise ratio is larger in the east, mostly because the low-frequency signals are larger there. The noise level for SST varies by as much as a factor of 10 among the locations studied, while noise in thermocline depth is relatively more homogeneous over the region. In general, noise due to aliased high-frequency variability increases by roughly a factor of 10 as the sample rate decreases from daily to 100-day sampling. The highly resolved spectra suggest a somewhat more optimistic estimate of overall signal-to-noise ratios for typical ship of opportunity (VOS) XBT sampling (generally about 2) than had been found in previous studies using sparser data. Time scales were estimated for various filtered versions of the time series by integration of the autocorrelation functions. For high-passed data (periods longer than about 150 days removed), the timescale is about 5 days for both surface and subsurface temperatures everywhere in the region. Conversely, for low-passed data (the annual cycle and periods shorter than 150 days removed), the timescale is roughly 100 days. Horizontal space scales were estimated from cross-correlations among the buoys. Zonal scales of low-frequency SST variations along the equator were half the width of the Pacific, larger than those of thermocline depth (about 30 degrees-40 degrees longitude). In the east, meridional scales of low-frequency SST were large (greater than about 15 degrees latitude), associated with the coherent waxing and waning of the equatorial cold tongue, whereas in the west these scales were shorter. Thermocline depth variations had meridional scales associated with the equatorial waves, particularly in the east. Spatial scale estimates reported here are generally consistent with those found from the VOS datasets when the ENSO signals in the records of each dataset are taken into account. However, if signals with periods of 1 to 2 months are to be properly sampled, then sampling scales of 1 degrees-2 degrees latitude by 8 degrees-10 degrees longitude, with a 5-day timescale, are needed. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEANS,SEATTLE,WA 98195. RP Kessler, WS (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Harrison, Don/D-9582-2013; Spillane, Michael/I-7870-2015; McPhaden, Michael/D-9799-2016 OI Spillane, Michael/0000-0003-0794-5675; NR 52 TC 43 Z9 43 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 2999 EP 3024 DI 10.1175/1520-0442(1996)009<2999:SOVITE>2.0.CO;2 PN 1 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF071 UT WOS:A1996WF07100006 ER PT J AU Harrison, DE Larkin, NK AF Harrison, DE Larkin, NK TI The COADS sea level pressure signal: A near-global El Nino composite and time series view, 1946-1993 SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION; SURFACE TEMPERATURE; NORTHERN HEMISPHERE; TROPICAL PACIFIC; ANOMALIES; WARM; WIND; VARIABILITY; EVOLUTION; EXTREMES AB Using GOADS data for the period 1946-1993, the near-global sea level pressure (SLP) patterns associated with interannual variability and the climatological seasonal march are discussed. A particular focus concerns the patterns associated with the two years before and after the South American sea surface temperatures rise (El Nino). The ten El Nino events in this record are composited and the robustness of the features of this composite is tested. Many features of the composite are quite robust; they occur during most El Nino events and are infrequent during non-El Nino periods. The most robust feature is an area of negative SLP anomaly (SLPA) in the eastern equatorial Pacific during Year(0) of the composite. This feature exceeds significance thresholds during every El Nino year and never during non-El Nino years; it correlates better with central Pacific SST variability than does the SOI. A west-central North Pacific positive SLPA, occurring late in Year(0) and lasting into the spring of Year(+1), is the second most robust feature. Strong SLPA signals occur in the eastern South Pacific and around Australia in many events, but the behavior varies greatly from event to event. Some events show interesting signals in the Indian and Atlantic Oceans, but the behavior is not sufficiently general to be a statistically meaningful element of the composite. The largest signals in the composite occur in the eastern equatorial and west-central North Pacific and not in the Southern Hemisphere. Thus, the large-scale SLP variations associated with El Nino periods are not dominated by the classical Southern Oscillation. Little evidence is found for phase propagation of the signal in El Nino years. Although several features of the composite occur during the same season in each El Nino period, so that the main signals are ''phase locked'' to the seasonal cycle, the patterns of variability have Little in common with the patterns of the seasonal march of SLP. C1 UNIV WASHINGTON,SCH OCEANOG,SEATTLE,WA 98115. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98115. RP Harrison, DE (reprint author), UNIV WASHINGTON,NOAA,OCRD,PMEL,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Harrison, Don/D-9582-2013 NR 32 TC 37 Z9 41 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3025 EP 3055 DI 10.1175/1520-0442(1996)009<3025:TCSLPS>2.0.CO;2 PN 1 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF071 UT WOS:A1996WF07100007 ER PT J AU Ji, M Leetmaa, A Kousky, VE AF Ji, M Leetmaa, A Kousky, VE TI Coupled model predictions of ENSO during the 1980s and the 1990s at the national centers for environmental prediction SO JOURNAL OF CLIMATE LA English DT Article ID NINO-SOUTHERN OSCILLATION; SEA-SURFACE TEMPERATURE; OCEAN-ATMOSPHERE MODEL; TROPICAL PACIFIC-OCEAN; EL-NINO; WIND STRESS; METEOROLOGICAL-CENTER; STATISTICAL-MODELS; CLIMATE FORECAST; SYSTEM AB In this paper, the authors discuss observed climatic variability from 1982 to early 1995 and emphasize the contrasts between the period of strong interannual variability during the 1980s and the period of more persistent features beginning in 1990. Three versions of the NCEP coupled forecast model, which were developed to predict interannual sea surface temperature variability in the equatorial Pacific, are described and their performance compared for those two periods. Climatic variability during 1982-1992 in the tropical Pacific was dominated by strong low-frequency interannual variations characterized by three warm and two cold El Nino episodes. However, beginning in 1990, the climate state has been characterized by a pattern of persistent positive SST anomalies in the tropical Pacific, especially in the central Pacific near the dare line, and weaker than normal trade winds. Superimposed on this were several occurrences of short-lived, generally small-amplitude warmings in the eastern equatorial Pacific. Some of the short-lived warmings amplified into mature warm episodes, such as in spring 1993 and in late 1994. The NCEP coupled models showed useful skill in predicting low-frequency SST variability associated with warm episodes in the tropical Pacific during the 1982-1992 period. However, the short-lived warmings in spring 1993 and fall/winter 1994/95 were not well predicted by the NCEP coupled models. Neither were they predicted by most of the other dynamic or statistical forecast models. Lf these short-lived warmings truly represent a different behavior of the coupled ocean-atmosphere system on intraseasonal timescales, the skill levels that were developed for predicting the strong low-frequency SST variability of the 1980s are probably not relevant. The lead times for skillful forecasts of short-lived episodes such as those observed in recent years will no doubt be only a few months. RP Ji, M (reprint author), NOAA,NWS,NATL CTR ENVIRONM PREDICT,5200 AUTH RD,ROOM 807,CAMP SPRINGS,MD 20746, USA. NR 40 TC 88 Z9 98 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3105 EP 3120 DI 10.1175/1520-0442(1996)009<3105:CMPOED>2.0.CO;2 PN 1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF071 UT WOS:A1996WF07100010 ER PT J AU Rasmusson, EM Mo, KC AF Rasmusson, EM Mo, KC TI Large-scale atmospheric moisture cycling as evaluated from NMC global analysis and forecast products SO JOURNAL OF CLIMATE LA English DT Article ID LOW-LEVEL JET; HYDROLOGIC-CYCLE; UNITED-STATES; PRECIPITATION; CIRCULATION; RAINFALL; BUDGET AB The broadscale aspects of the annual cycle of monthly mean global water vapor flux, flux divergence, evaporation, and precipitation derived from the National Meteorological Center (NMC) global analysis and forecast products were examined with two objectives in mind: 1) a critical evaluation of the usefulness of recent NMC products for descriptive and diagnostic studies of the global hydrological cycle and in the process and 2) to provide additional information on the behavior of the annual cycle of selected hydrological parameters over the globe in general and over the United States in particular. The 2-year period August 1991-July 1993, was chosen for study. The global-scale characteristics of the NMC vertically integrated vapor flux fields are described in terms of the rotational and divergent components of the stationary and transient parts of the vapor flux field. Values of the zonally averaged meridional vapor flux derived from the NMC analyses are broadly similar to those presented by Peixoto and Oort, but differences are substantial in the Southern Hemisphere. The magnitude of the NMC meridional flux is generally larger in the middle latitudes, partly because of a larger transient flux. The seasonally varying spinup characteristics of the NMC evaporation (E) and precipitation (P) forecasts are examined in terms of differences between the 0-6 h and 12-36 h forecasts. Spinup in P is much larger than spinup in E and is most pronounced (spindown) in the latitudes of the equatorial convergence zones. Comparisons of annual precipitation derived from the NMC 0-6 h forecast with values from the Legates and Willmott and the Jaeger climatologies, and with values from the GPI satellite IR algorithm for the Tropics, are summarized and discussed. Questionable zonally averaged and regional features are identified, but differences are often hard to reconcile due to uncertainties in all the methods of estimation. The value of the NMC vapor flux analyses for studies of continental-scale hydrology is examined by comparing annual P-E derived from the vapor flux divergence field with annual surface runoff derived from mean annual river discharge. The comparison reveals an unrealistic flux divergence field over the continent that appears to be terrain related. A similar bias is not apparent in the forecast P-E field, suggesting that it arises from problems of model resolution and data assimilation. C1 US DEPT COMMERCE,NOAA,NATL CTR ENVIRONM PREDICT,NWS,ANAL BRANCH,CLIMATE PREDICT CTR,WASHINGTON,DC 20233. UNIV MARYLAND,DEPT METEOROL,COLLEGE PK,MD 20742. NR 25 TC 37 Z9 41 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3276 EP 3297 DI 10.1175/1520-0442(1996)009<3276:LSAMCA>2.0.CO;2 PN 2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF072 UT WOS:A1996WF07200006 ER PT J AU Brenner, S AF Brenner, S TI Response of an ocean mixed layer model in 30-day December forecasts with a coupled ocean-Atmosphere model SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; NATIONAL-METEOROLOGICAL-CENTER; EL NINO; RANGE FORECASTS; CLIMATE MODEL; ARABIAN SEA; SYSTEM; CIRCULATION; VARIABILITY; CYCLE AB A mixed layer model of the upper ocean was coupled to the global medium-range forecast model of the National Centers for Environmental Prediction. The ocean model is of the type commonly referred to as a bulk model and includes detailed parameterizations of wind mixing, convective overturning; heating and cooling by surface fluxes, heating by penetrative radiation, and large-scale vertical advection driven by the curl of the wind stress. It is run on the Gaussian grid of the T62 version of the atmospheric model. The ocean and atmospheric models exchange information once every 3 h. Results are presented from a series of nine 30-day December forecasts. Each of the nine cases consisted of a one-way interaction forecast (the atmosphere forces the ocean only) and a two-way interaction forecast (predicted sea surface temperatures fed back into the atmospheric model). In the one-way forecasts, the model's skill is better than persistence at all times and comparable to or better than a persistent initial anomaly forecast out to 3 weeks in the extratropics and out to 12 days in the Tropics. In general, the two-way feedback acts to reduce the magnitude of net surface heat flux, leading to a slight increase in forecast skill in the Tropics and the Southern Hemisphere. Finally, a preliminary assessment of the effects of the initial conditions shows that the forecasts in the winter hemisphere are indeed sensitive to the specification of the initial subsurface temperature profiles since the rate of wintertime cooling of the sea surface is closely related to the heat content (i.e., vertical structure) of the upper water column. In net surface heating regimes (the Tropics and the summer hemisphere) the forecasts are not particularly sensitive to the initial profiles since here the predicted mixed layer depths are determined by the balance between the net surface heating and the downward transport of heat by the wind-induced mixing. C1 NATL CTR ENVIRONM PREDICT,ENVIRONM MODELING CTR,WASHINGTON,DC. NR 38 TC 2 Z9 2 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3337 EP 3356 DI 10.1175/1520-0442(1996)009<3337:ROAOML>2.0.CO;2 PN 2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF072 UT WOS:A1996WF07200010 ER PT J AU Peixoto, JP Oort, AH AF Peixoto, JP Oort, AH TI The climatology of relative humidity in the atmosphere SO JOURNAL OF CLIMATE LA English DT Article ID TROPOSPHERIC WATER-VAPOR; SEA-SURFACE TEMPERATURE; MOISTURE; CLOUD; OCEAN AB The present paper deals with the analysis of the time-average relative humidity fields in the atmosphere. Twice-daily estimates of relative humidity are used. After some theoretical considerations on the relations between relative humidity, other moisture parameters, and temperature, a critical analysis of the various sources of data is made considering their possible limitations. Various methods of computing relative humidity are formulated and discussed. The global distribution of relative humidity at various levels shows that it is not zonally uniform with centers of various intensities at all latitudes. The global maps show maxima in the equatorial zone and minima in the dry subtropical belts around 30 degrees N and 30 degrees S. The land-sea contrast and variations related to the orographic relief are also apparent. The general pattern of relative humidity is similar at all levels but its magnitude decreases with altitude. The seasonal analyses show a similar pattern as the annual analyses but are slightly shifted toward the summer pole. The saturation deficit is also evaluated. Cross sections of the saturation deficit show that the maxima are found in the middle to lower troposphere at subtropical latitudes, being most intense in the Northern Hemisphere during the summer season. The temporal variability of the relative humidity due to transient eddies exhibits a bimodal structure with maxima in the midlatitudes of each hemisphere around 700 mb. The stationary eddy distributions are less pronounced than the transient ones and do not change substantially from one season to another. To validate our results, several comparisons are made using independent sources of humidity data as well as cloud distributions at various levels. Thus, GOADS data are used to obtain independent analyses of the surface relative humidity over the oceans, and satellite observations by SAGE are used at the 300-mb level. The rawinsonde-SAGE differences are on the order of 10% in the Tropics and 20% in the high latitudes, due in part to a clear-sky (dry) bias in the SAGE data. Our results are further compared with those obtained from operational analyses by the ECMWF. The differences do not exceed 5% in the Tropics but tend to be larger in the tropical upper troposphere and at all levels in the extratropics of the Southern Hemisphere, where the radiosonde network is quite sparse. In view of the obvious connections between the moisture distribution in the atmosphere and cloudiness, a cloud climatology is used to check its consistency with the present results. The latitudinal and interseasonal variations of cloudiness and relative humidity are similar, with maxima in the equatorial belt and at high latitudes and minima in the subtropics that shift poleward during summer and equatorward during winter. Finally, some comments are made on the radiosonde-observing systems in the light of recent satellite studies of humidity. Mainly at the upper levels systematic localized differences are found between electrical hygristor and organic sensors, but the differences almost disappear in the middle and lower troposphere. In spite of the shortcomings, limitations, and errors of the radiosonde network, the present analyses describe for the first time the large-scale, three-dimensional characteristics of the relative humidity in the global atmosphere. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. UNIV LISBON,P-1699 LISBON,PORTUGAL. NR 43 TC 91 Z9 92 U1 2 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3443 EP 3463 DI 10.1175/1520-0442(1996)009<3443:TCORHI>2.0.CO;2 PN 3 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF073 UT WOS:A1996WF07300005 ER PT J AU Ross, RJ Elliott, WP AF Ross, RJ Elliott, WP TI Tropospheric water vapor climatology and trends over North America: 1973-93 SO JOURNAL OF CLIMATE LA English DT Article ID TEMPERATURE; HUMIDITY; RADIOSONDE; HEMISPHERE AB Here 21 years of radiosonde observations from stations in the Western Hemisphere north of the equator were analyzed for trends in tropospheric water vapor. Mean fields of precipitable water and relative humidity at several levels are shown. Annual trends of surface-500 mb precipitable water were generally increasing over this region except over northeastern Canada. When trends were expressed as a percentage of the climatological mean at each station, the trends south of similar to 45 degrees N represent a linear rate of increase of 3%-7% decade(-1). Trends in the upper portion of this layer, 700-500 mb, were as large or larger than those of the middle (850-700 mb) or lower layer and were consistent in sign. Annual trends in dewpoint generally agree in sign with trends in temperature. However, the dewpoint trends tended to be larger than those of temperature. This was consistent with the annual increases found in relative humidity over this period. Relative humidity increased except in Canada, Alaska, and a few stations in western mountainous areas. Largest percentage increases of relative humidity were in the Tropics. Seasonal trends of precipitable water varied spatially more than the annual trends and fewer were statistically significant. More stations had significant trends in summer than in other seasons and these were located over the central and eastern United States and the Tropics. Spring trends were largest over the western United States, while the largest winter trends were along the Gulf Coast. The one area where significant water vapor increases were found in all four seasons was the Caribbean. RP Ross, RJ (reprint author), NOAA,AIR RESOURCES LAB,1315 EW HIGHWAY,SILVER SPRING,MD 20910, USA. NR 31 TC 115 Z9 118 U1 2 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1996 VL 9 IS 12 BP 3561 EP 3574 DI 10.1175/1520-0442(1996)009<3561:TWVCAT>2.0.CO;2 PN 3 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF073 UT WOS:A1996WF07300011 ER PT J AU Halliwell, GR Mayer, DA AF Halliwell, GR Mayer, DA TI Frequency response properties of forced climatic SST anomaly variability in the North Atlantic SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; HEAT-FLUX ANOMALIES; ATMOSPHERIC CIRCULATION; OCEAN; LATENT; WINTER; MODEL AB Frequency response properties of North Atlantic (5 degrees-57 degrees N) sea surface temperature anomaly (T-sa) variability with periods of several months to 20 years are characterized using the Comprehensive Ocean-Atmosphere Data Set (GOADS). Significant direct forcing of T-sa variability by the anomalous wind field (primarily through the resulting anomalous surface turbulent heat flux) is observed in the westerly wind and trade wind belts. To characterize properties of the large-scale climatic T-sa response to this forcing over the entire frequency band resolved, it is necessary to consider the dual role of anomalous surface heat flux as both the dominant local forcing mechanism and the dominant damping mechanism, the latter through a negative linear feedback (Newtonian relaxation). At frequencies where wind forcing is important, good agreement exists between the frequency response function estimated from data and the same function theoretically predicted by a simple stochastic forcing model where the locally forced response is damped by a negative linear feedback with a decay time scale of 3 mo. To make this comparison, the total anomalous surface heal flux represented by the standard bulk formula was decomposed into two components, one primarily representing the local wind forcing and the other primarily representing negative feedback damping. In the westerlies, wind forcing is effective over periods from several months to 8 yr, primarily 2-4 yr, and is ineffective at periods of 8-20 yr. These fluctuations are primarily forced in the western part of the basin then propagate to the east and northeast across the Atlantic at a characteristic speed of 6 km day(-1). When time series of winter-only T-sa are analyzed, however, wind forcing of winter to winter T-sa variability remains significant at decadal and longer periods. In the trades, wind forcing is effective over periods from 8 mo to 13.3 yr, primarily 2-3 yr and 7-13.3 yr, and significant seasonal differences are not observed. C1 AOML, NOAA, PHYS OCEANOG DIV, MIAMI, FL USA. RP UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MPO, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Halliwell, George/B-3046-2011 OI Halliwell, George/0000-0003-4216-070X NR 26 TC 25 Z9 26 U1 0 U2 0 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 DEC PY 1996 VL 9 IS 12 BP 3575 EP 3587 DI 10.1175/1520-0442(1996)009<3575:FRPOFC>2.0.CO;2 PN 3 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WF073 UT WOS:A1996WF07300012 ER PT J AU Voronovich, A AF Voronovich, A TI Non-parabolic marching algorithm for sound field calculation pn the ocean waveguide SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article ID ACOUSTIC TOMOGRAPHY; PROPAGATION; EQUATIONS AB An algorithm is presented for calculating sound field in the inhomogeneous ocean waveguide. It does not involve parabolic approximation and can be considered as principally exact (at least for 2D inhomogeneities of the sound speed field). On the other hand, it is ''marching'' and can be easily implemented as a computer code (note, that marching in this case proceeds in ''backward'' direction, i.e. towards the source). Those features of the code are similar to couple mode algorithm (COUPLE) developed originally by R. Evans. The principal difference is that suggested code does not assume piecewise constant approximation of the waveguide properties with respect to horizontal coordinates. As a result, the horizontal steps of marching can be increased significantly. The estimate of the efficiency of the approach as compared to stepwise couple modes method is given. The results of the code testing with the help of benchmark problem as well as calculation of sound propagation through a strong inhomogeneity formed by the sub-arctic front are presented. The present version of the code can be used to calculate entries of scattering matrix (S-matrix) for the ocean waveguide as well as travel times of different modes (derivatives of phases of corresponding entries with respect to frequency). ii priori restrictions on S-matrix (reciprocity and energy conservation) are also given, and some objective quantitative criterion of the accuracy of the numerical algorithms formulated in terms of S-matrix is suggested. RP Voronovich, A (reprint author), NOAA, ENVIRONM RES LAB, ENVIRONM TECHNOL LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 15 TC 5 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-396X J9 J COMPUT ACOUST JI J. Comput. Acoust. PD DEC PY 1996 VL 4 IS 4 BP 399 EP 423 DI 10.1142/S0218396X96000155 PG 25 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA VZ785 UT WOS:A1996VZ78500005 ER PT J AU Coriell, SR Murray, BT Chernov, AA McFadden, GB AF Coriell, SR Murray, BT Chernov, AA McFadden, GB TI Step bunching on a vicinal face of a crystal growing in a flowing solution SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID KINETIC SELF-STABILIZATION; MORPHOLOGICAL STABILITY; INTERFACE; GROWTH AB The effect of a parallel shear flow and anisotropic interface kinetics on the onset of (linear) instability during growth from a supersaturated solution is analyzed including perturbations in the flow velocity. The model used for anisotropy is based on the microscopic picture of step motion. A shear flow (linear Couette flow or asymptotic suction profile) parallel to the crystal-solution interface in the same direction as the step motion (negative shear) decreases interface stability. For large wavenumbers k(x), the perturbed flow field can be neglected and a simple analytic approximation for the stability-instability demarcation is found. A shear flow counter to the step motion (positive shear) enhances stability and for sufficiently large shear rates (on the order of 1 s(-1)) the interface is morphologically stable. Alternatively, the approximate analysis predicts that the system is unstable if the solution flow velocity in the direction of the step motion at a distance (2k(x))(-1) from the interface exceeds the propagation rate upsilon(x) of step bunches induced by the interface perturbations. The approximate results are applied to the growth of ADP and lysozyme. For sufficiently low supersaturations, the interface is stable for positive shear and unstable for negative shear. More generally, there is a critical negative shear rate for which the interface becomes unstable as the magnitude of the shear rate increases. For a range of growth conditions for ADP, the magnitude of this critical shear rate is 2k(x) upsilon(x). Even shear rates due to natural convection may be sufficient to affect stability for typical growth conditions. RP Coriell, SR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 25 TC 53 Z9 55 U1 1 U2 2 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 DEC PY 1996 VL 169 IS 4 BP 773 EP 785 DI 10.1016/S0022-0248(96)00470-8 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VZ771 UT WOS:A1996VZ77100025 ER PT J AU Croll, DA Jansen, JK Goebel, ME Boveng, PL Bengtson, JL AF Croll, DA Jansen, JK Goebel, ME Boveng, PL Bengtson, JL TI Foraging behavior and reproductive success in chinstrap penguins: The effects of transmitter attachment SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article ID INSTRUMENT AB The effects of radio transmitter attachment on foraging trip duration and reproductive success of breeding Chinstrap Penguins (Pygoscelis antarctica) were studied on Seal Island, South Shetland Islands, Antarctica. Attachment of transmitters having a cross-sectional area 0.9% that of the penguin had no significant effect on foraging trip duration, nest visit duration or the number of foraging trips per nest per day. Adults equipped with transmitters had significantly lower chick survival rates than control animals, however. This difference resulted from a higher nest failure rare of transmitter-equipped adults. Most of these failures occurred in the early part of the guard period. The average number of chicks raised to the creche stage in successful nests was similar for control and transmitter-equipped animals. Thus, chick mortality occurred as a result of failure of the entire nest (i.e., abandonment by the adults) rather than lowered chick survival in individual nests. Nests at which both members were equipped with transmitters failed at a higher rate than nests at which one member was equipped with a transmitter. The transmitters used in this study may be considered a maximum size to be used for foraging trip duration experiments of medium-sized penguins. C1 NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. NR 15 TC 30 Z9 30 U1 2 U2 3 PU ASSOC FIELD ORNITHOLOGISTS PI BELOIT PA BELOIT COLLEGE, DEPT BIOLOGY, 700 COLLEGE ST, BELOIT, WI 53511 SN 0273-8570 J9 J FIELD ORNITHOL JI J. Field Ornithol. PD WIN PY 1996 VL 67 IS 1 BP 1 EP 9 PG 9 WC Ornithology SC Zoology GA TR662 UT WOS:A1996TR66200001 ER PT J AU Emery, BA Lu, G Szuszczewicz, EP Richmond, AD Roble, RG Richards, PG Miller, KL Niciejewski, R Evans, DS Rich, FJ Denig, WF Chenette, DL Wilkinson, P Pulinets, S OLoughlin, KF Hanbaba, R Abdu, M Jiao, P Igarashi, K Reddy, BM AF Emery, BA Lu, G Szuszczewicz, EP Richmond, AD Roble, RG Richards, PG Miller, KL Niciejewski, R Evans, DS Rich, FJ Denig, WF Chenette, DL Wilkinson, P Pulinets, S OLoughlin, KF Hanbaba, R Abdu, M Jiao, P Igarashi, K Reddy, BM TI Assimilative mapping of ionospheric electrodynamics in the thermosphere-ionosphere general circulation model comparisons with global ionospheric and thermospheric observations during the GEM/SUNDIAL period of March 28-29, 1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HIGH-LATITUDE IONOSPHERE; GEOMAGNETIC STORM; VERTICAL WINDS; POLAR-CAP; LOCALIZED OBSERVATIONS; MERIDIONAL WINDS; ELECTRIC-FIELDS; SEPTEMBER 18-19; MAGNETIC STORM; NEUTRAL WINDS AB Satellite and ground-based observations fi om March 28 to 29, 1992, were combined in the assimilative mapping of ionospheric electrodynamics (AMIE) procedure to derive realistic global distributions of the auroral precipitation and ionospheric convection which were used as inputs to the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere general circulation model (TIGCM). Comparisons of neutral model winds were made with Fabry-Perot measurements and meridional winds derived front ionosondes. The peak equatorward winds occurred 1-2 hours later in the model. Gravity waves launched from high-latitude Joule heating sources reached;the equator in about 2 hours and agreed with observed variations in the height of the maximum electron density (hmF2) and in the meridional winds. Joule heating events produced minima in the O/N-2 ratio that moved equatorward and usually westward in longitudinal strips which lasted about a day. Changes in the O/N-2 ratio and in the peak electron density (NmF2) were strongly correlated so the observed daytime NmF2 values for stations near 50 degrees magnetic latitude were generally reproduced by AMIE-TIGCM. on the second day of the simulation, The AMIE-TIGCM underestimated the electron density after midnight by up to a factor of 2 in midlatitudes, while the modeled F2 layer was about 35 km lower than the observations at midnight. Shifting the model winds 2 hours earlier at night could double the NmF2 at 0400 LT and increase hmF2 by 20 km. NmF2 could also be increased:at night by realistically increasing the TIGCM nighttime downward fluxes of O+ at the upper boundary. C1 SCI APPLICAT INT CORP,LAB ATMOSPHER & SPACE SCI,MCLEAN,VA 22102. UNIV ALABAMA,DEPT COMP SCI,HUNTSVILLE,AL 35899. UNIV MICHIGAN,SPACE PHYS RES LAB,ANN ARBOR,MI 48109. NOAA,SPACE ENVIRONM CTR,BOULDER,CO. PHILLIPS LAB,GEOPHYS DIRECTORATE,BEDFORD,MA. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. IPS,RADIO SERV,W CHATSWOOD,AUSTRALIA. IPS,SPACE SERV,W CHATSWOOD,AUSTRALIA. IZMIRAN,INST TERR MAGNETISM IONOSPHERE & RADIOWAVE PROPAG,TROITSK,RUSSIA. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO. CTR NATL ETUD TELECOMMUN,LANNION,FRANCE. INST NACL PESQUISAS ESPACIAIS,DIV AERON,S JOSE CAMPOS,BRAZIL. CHINA RES INST RADIOWAVE PROPAGAT,XINXIANG,HENAN,PEOPLES R CHINA. MINIST POSTS & TELECOMMUN,UPPER ATMOSPHERE SECT,COMMUN RES LAB,TOKYO,JAPAN. NATL PHYS LAB,DIV RADIO SCI,NEW DELHI 110012,INDIA. RP Emery, BA (reprint author), NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,POB 3000,BOULDER,CO 80307, USA. RI Lu, Gang/A-6669-2011; Pulinets, Sergey/F-7462-2011 OI Pulinets, Sergey/0000-0003-3944-6686 NR 54 TC 27 Z9 27 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1996 VL 101 IS A12 BP 26681 EP 26696 DI 10.1029/96JA01285 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW423 UT WOS:A1996VW42300001 ER PT J AU Lu, G Emery, BA Rodger, AS Lester, M Taylor, JR Evans, DS Ruohoniemi, JM Denig, WF delaBeaujardiere, O Frahm, RA Winningham, JD Chenette, DL AF Lu, G Emery, BA Rodger, AS Lester, M Taylor, JR Evans, DS Ruohoniemi, JM Denig, WF delaBeaujardiere, O Frahm, RA Winningham, JD Chenette, DL TI High-latitude ionospheric electrodynamics as determined by the assimilative mapping of ionospheric electrodynamics procedure for the conjunctive SUNDIAL ATLAS 1 GEM period of March 28-29, 1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WESTWARD TRAVELING SURGE; INCOHERENT-SCATTER RADAR; ENERGY INJECTION RATE; EXOS-D SATELLITE; GEOMAGNETIC STORM; SOLAR-WIND; PARTICLE-PRECIPITATION; LOCALIZED OBSERVATIONS; AURORAL IONOSPHERE; SUBSTORM EXPANSION AB During the conjunctive SUNDIAL/ATLAS 1/GEM campaign period of March 28-29, 1992, a set of comprehensive data has been collected both from space and from ground. The assimilative mapping of ionospheric electrodynamics (AMIE) procedure is used to derive the large-scale high-latitude ionospheric conductivity, convection, arid other related quantities, by combining the various data sets. The period was characterized by several moderate substorm activities. Variations of different ionospheric electrodynamic fields are examined for one substorm interval. The cross-polar-cap potential drop, Joule heating, and field-aligned current are all enhanced during the expansion phase of substorms. The most dramatic changes of these fields are found to be associated with the development of the substorm electrojet in the post midnight region. Variations of global electrodynamic quantities for this 2-day period have revealed a good correlation with the auroral electrojet (AE) index. In this study we have calculated the AE index from ground magnetic perturbations observed by 63 stations located between 55 degrees and 76 degrees magnetic latitudes north and south, which is larger than the standard AE index by about 28% on the average over these 2 days. Different energy dissipation channels have also been estimated. On the average over the 2 days, the total globally integrated Joule heating rate is about 102 GW and the total globally integrated amoral energy precipitation rate is about 52 GW. Using an empirical formula, the ring current energy injection rate is estimated to be 125 GW for a decay time of 3.5 hours, and 85 GW for a decay time of 20 hours. We also find an energy-coupling efficiency of 3% between the solar wind and the magnetosphere for a southward interplanetary magnetic field (IMF) condition. C1 BRITISH ANTARCTIC SURVEY, CAMBRIDGE CB3 0ET, ENGLAND. UNIV LEICESTER, DEPT PHYS & ASTRON, LEICESTER LE1 7RH, LEICS, ENGLAND. NOAA, SPACE ENVIRONM LAB, BOULDER, CO 80303 USA. JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD USA. NATL SCI FDN, ARLINGTON, VA 22230 USA. PHILLIPS LAB, BEDFORD, MA USA. SW RES INST, SAN ANTONIO, TX USA. LOCKHEED PALO ALTO RES LABS, PALO ALTO, CA 94304 USA. RP Lu, G (reprint author), NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, POB 3000, BOULDER, CO 80307 USA. RI Lu, Gang/A-6669-2011 NR 50 TC 41 Z9 41 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1996 VL 101 IS A12 BP 26697 EP 26718 DI 10.1029/96JA00513 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW423 UT WOS:A1996VW42300002 ER PT J AU Szuszczewicz, EP Torr, D Wilkinson, P Richards, P Roble, R Emery, B Lu, G Abdu, M Evans, D Hanbaba, R Igarashi, K Jiao, P Lester, M Pulinets, S Reddy, BM Blanchard, P Miller, K Joselyn, J AF Szuszczewicz, EP Torr, D Wilkinson, P Richards, P Roble, R Emery, B Lu, G Abdu, M Evans, D Hanbaba, R Igarashi, K Jiao, P Lester, M Pulinets, S Reddy, BM Blanchard, P Miller, K Joselyn, J TI F region climatology during the SUNDIAL/ATLAS 1 campaign of March 1992: Model-measurement comparisons and cause-effect relationships SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; PEAK ELECTRON-DENSITY; SOLAR EUV FLUX; GLOBAL-SCALE; THERMOSPHERIC TIDES; MERIDIONAL WINDS; EMPIRICAL-MODEL; NEUTRAL WINDS; LOW LATITUDES; IONOSPHERE AB We present the first joint comparison of global measurements of F region characteristics with three models used widely in the specification of the ionospheric-thermospheric system. The models, the International Reference Ionosphere (IRI), the field line interhemispheric plasma (FLIP) model, and the Thermospheric-Ionospheric General Circulation Model (TIGCM), represent a unique set of capabilities with major differences in approaches to the prevailing physics and different levels of computational complexity. The database was developed by a global network of 53 ionosonde stations operating around-the-clock for the period March 22 through April 4, 1992 in collaboration with the ATLAS 1 mission. The emphasis is on the F region characteristics of peak heights (h(m)F(2)) and densities (NmF2), their climatological (i.e., average) behavior during the ATLAS 1 period, and associated cause-effect relationships. We explore latitudinal and local time variations with attention to the influences of meridional winds and plasmaspheric fluxes in the maintenance of different domains in the ionospheric-thermospheric system. We find that all three models tend to underestimate the values of h(m)F(2) and NmF2 with the largest discrepancies in NmF2 resulting in the FLIP and TIGCM representations at night. These discrepancies can grow to levels as large as 110% near 0400 LT, a ''rediscovery'' of the old but unsettled issue of maintenance of the nighttime ionosphere. This nighttime discrepancy is traceable in first order to model underestimates of prevailing meridional winds. The contributions of plasmaspheric fluxes are also considered, with the conclusion that they are of secondary importance, but substantially more work is necessary to uniquely quantify their role. In contrast to their nighttime characteristics, the FLIP and TIGCM generally have excellent agreement (i.e., 6 +/- 6%) with daytime observations of NmF2, and the IRI tends to underestimate the observed values of NmF2 by a nominally LT-insensitive level of 28 +/- 6%. Other campaign results are reviewed in this issue, with a focus on regional responses to the prevailing conditions and their characterization in terms of latitudinal distributions off region heights and densities. C1 INST NACL PESQUISAS ESPACIAIS,S JOSE CAMPOS,SP,BRAZIL. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NOAA,BOULDER,CO 80303. FRANCE TELECOM,CNET,F-22301 LANNION,FRANCE. MINIST POSTS & TELECOMMUN,COMMUN RES LAB,TOKYO 184,JAPAN. CHINA RES INST RADIO PROPAGAT,XINXIANG 453003,HENAN,PEOPLES R CHINA. UNIV LEICESTER,DEPT PHYS,LEICESTER LE1 7RH,LEICS,ENGLAND. UNIV UTAH,CTR ATMOSPHER & SPACE SCI,LOGAN,UT 84322. IZMIRAN,TROITSK 142092,RUSSIA. NATL PHYS LAB,NEW DELHI 110012,INDIA. UNIV ALABAMA,HUNTSVILLE,AL 35899. IPS,RADIO SERV,W CHATSWOOD,NSW 2057,AUSTRALIA. IPS,SPACE SERV,W CHATSWOOD,NSW 2057,AUSTRALIA. RP Szuszczewicz, EP (reprint author), SCI APPLICAT INT CORP,MS 2-3-1,1710 GOODRIDGE DR,MCLEAN,VA 22102, USA. RI Lu, Gang/A-6669-2011; Pulinets, Sergey/F-7462-2011 OI Pulinets, Sergey/0000-0003-3944-6686 NR 67 TC 12 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1996 VL 101 IS A12 BP 26741 EP 26758 DI 10.1029/96JA01774 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW423 UT WOS:A1996VW42300005 ER PT J AU Pulinets, SA Yudakhin, KF Evans, D Lester, M AF Pulinets, SA Yudakhin, KF Evans, D Lester, M TI Study of the ionospheric variability within the Euro-Asian sector during the SUNDIAL/ATLAS 1 mission SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB In order to quantify, and to identify possible origins of, subauroral ionospheric variability during periods of moderate geomagnetic activity, ionospheric observations taken during the SUNDIAL/ATLAS - 1 campaign (March 24 to April 2) from 10 stations were analyzed in conjunction with observations from EISCAT, geomagnetic observations from magnetometer networks in Scandinavia and the United Kingdom, and auroral particle energy input observations from the NOAA - 12 satellite. The network of ionospheric stations spanned longitudes from 13 degrees E to 90 degrees E but were relatively confined in geomagnetic latitudes so that longitudinal and local time dependencies in ionospheric variability are more clearly exposed. The ionospheric observations were analyzed in terms of both Delta f(o)F2, the difference between the hourly f(o)F2 at a given station and the monthly median f(o)F2 for that hour, and a new daily variability index Af(o)F2. The analysis using both parameters demonstrated an apparent longitudinal variation in ionospheric variability with a reversal at about 55 degrees E from a negative to a positive phase in the departure of ionospheric renditions from their median values. An analysis of these ionospheric data in conjunction with the NOAA/TIROS estimates of power deposition by auroral particles demonstrated a Significant local time dependence in midlatitude ionospheric responses to amoral activity. This dependence may arise from the premidnight to postmidnight asymmetry in high-latitude convection electric fields. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,LEICS,ENGLAND. RP Pulinets, SA (reprint author), IZMIRAN,TROITSK 142092,RUSSIA. RI Pulinets, Sergey/F-7462-2011 OI Pulinets, Sergey/0000-0003-3944-6686 NR 22 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1996 VL 101 IS A12 BP 26759 EP 26767 DI 10.1029/96JA02411 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW423 UT WOS:A1996VW42300006 ER PT J AU Gupta, VK Castro, SL Over, TM AF Gupta, VK Castro, SL Over, TM TI On scaling exponents of spatial peak flows from rainfall and river network geometry SO JOURNAL OF HYDROLOGY LA English DT Article; Proceedings Paper CT International Conference on Fractals in Hydrology CY 1993 CL ISCHIA, ITALY ID RUNOFF GENERATION; FLOOD; DISTRIBUTIONS; MULTIFRACTALS; TURBULENCE; DIMENSION; MODEL AB The hypothesis of statistical self-similarity, or scaling invariance, in the spatial variability of rainfall, channel network structures and floods has been supported by recent advances in data analyses. This hypothesis is used here to calculate the statistical scaling exponents of peak river flows using a random cascade model of spatial rainfall intensities and the Peano basin as an idealized model of a river basin. The 'maximum contributing set' approximately determines the magnitudes of peak flows in a self-similar manner in different subbasins of the Peano basin. For an instantaneously applied random, spatially uniform rainfall, the Hausdorff dimension of the maximum contributing set appears as the statistical simple scaling exponent of peak flows. This result is generalized to an instantaneously applied cascade rainfall, and it is shown to give rise to statistical multiscaling in peak flows. The multiscaling exponent of peak flows is computed and interpreted as a Hausdorff dimension of a fractal set supporting rainfall intensity on the maximum contributing set of the Peano basin. Potential implications of this interpretation are illustrated using the regional food frequency analysis of the Appalachian flood data in the United States and a rainfall data set from the tropical Atlantic ocean. It is argued that the hypothesis of self-similarity identifies a powerful theoretical framework which can unify a statistical theory of regional flood frequency with important empirical features of topographic, rainfall and flood data sets and distributed rainfall-landform-runoff relationships. C1 UNIV COLORADO,CTR STUDY EARTH SPACE,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. TEXAS A&M UNIV,DEPT CIVIL ENGN,COLLEGE STN,TX 77843. RP Gupta, VK (reprint author), UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309, USA. RI Castro, Sandra/A-4979-2012 NR 37 TC 70 Z9 71 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC PY 1996 VL 187 IS 1-2 BP 81 EP 104 DI 10.1016/S0022-1694(96)03088-0 PG 24 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA VZ773 UT WOS:A1996VZ77300006 ER PT J AU Sanders, PG Weertman, JR Barker, JG AF Sanders, PG Weertman, JR Barker, JG TI Structure of nanocrystalline palladium and copper studied by small angle neutron scattering SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTRON-MICROSCOPY; GRAIN-BOUNDARIES; PD; MICROHARDNESS; SPECTROSCOPY; SILVER; CU AB The structure of nanocrystalline palladium and copper, made by inert gas condensation and compaction, was studied using small angle neutron scattering (SANS), optical microscopy, and scanning electron microscopy. The effects of annealing and warm compaction were also examined with these techniques. The SANS results were interpreted using a maximum entropy routine, combined with knowledge of the Archimedes density and hydrogen concentration determined by prompt gamma activation analysis (PGAA), Similar hydrogen concentrations were detected by SANS and PGAA. This hydrogen content, which was approximately 5 at. % in samples compacted at room temperature, was reduced by both annealing and warm compaction. Defects in several size classes were observed, including missing grain pores (approximate to 1-50 nm diameter) and defects of micrometer size. Warm compaction produced a lower number density of pores in nanocrystalline palladium, which led to increased density. The observed structure was correlated with Vickers microhardness and fracture surface morphology. C1 NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. NIST, COLD NEUTRON RES FACIL, GAITHERSBURG, MD 20899 USA. RI Weertman, Julia/B-7540-2009 NR 38 TC 21 Z9 22 U1 1 U2 9 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD DEC PY 1996 VL 11 IS 12 BP 3110 EP 3120 DI 10.1557/JMR.1996.0395 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA VX289 UT WOS:A1996VX28900024 ER PT J AU Marchiando, JF AF Marchiando, JF TI On calculating the reflectance and transmittance of light for a simple thick grating structure SO JOURNAL OF MODERN OPTICS LA English DT Article ID DIFFRACTION AB This paper presents a formulation for calculating the reflectance and transmittance of classical light for a simple structure that contains a rectangularly shaped line grating layer that lies atop a thick transparent or weakly absorbing substrate layer. It is assumed that the substrate thickness is sufficiently large and non-uniform that when the light traverses it is averaged over a large surface area, the averaged field is considered as losing phase coherence and intensities can be added. It is assumed that the optical properties of the media in the various homogeneous regions of the structure are complex, local, linear, isotropic, and non-magnetic. This kind of structure has important applications in the metrology of linewidths for the semiconductor integrated circuit industry. RP Marchiando, JF (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECT,BLDG 225,ROOM A305,GAITHERSBURG,MD 20899, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD DEC PY 1996 VL 43 IS 12 BP 2493 EP 2501 PG 9 WC Optics SC Optics GA VX224 UT WOS:A1996VX22400006 ER PT J AU Wacongne, S Pacanowski, R AF Wacongne, S Pacanowski, R TI Seasonal heat transport in a primitive equations model of the tropical Indian Ocean SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ATLANTIC-OCEAN; ANNUAL CYCLE; SOMALI CURRENT; WORLD OCEAN; CIRCULATION MODELS; PACIFIC-OCEAN; DEEP CURRENTS; WIND STRESS; ARABIAN SEA; BUDGET AB This work analyzes seasonal heat transport in an ocean-only numerical simulation of the Indian Ocean forced by realistic seasonal winds and surface hear fluxes north of 15 degrees S, assuming no Indonesian Throughflow. The seasonal changes in the model circulation and temperature structure are found to be overall consistent with observations, despite fluxes in sea surface temperature and mixed layer depth. The simulation confirms that the reversal of the monsoons and of the associated Ekman transports plays an important role in reversing the sign of the ocean heat transport seasonally causing, in particular, the Arabian Sea's drastic annual cooling, but it suggests that south of 10 degrees N, deep boundary currents must reverse as well. Most of the model heat transport is carried by a deep downwelling cell during the northeast monsoon and by a shallower upwelling cell during the southwest monsoon. An analysis of the three-dimensional circulation reveals that, in boreal summer, the net -1.2 pW (1 pW = 10(15) W) cross-equatorial model heat transport derives mostly from a 20 x 10(6) m(3) s(-1) northward boundary current at intermediate levels (12.5 degrees C) returned over the interior at the surface (27.5 degrees C). In boreal winter, the net +1 pW heat transport derives mostly from a 10 x 10(6) m(3) s(-1) northward interior surface flow (27.5 degrees C) returned in several deep southward boundary currents (5 degrees C). It is argued that the +1 pW February heat transport value is realistic and that a deep overturning cell must therefore exist otherwise the return branch of the relatively small February Ekman transport would have to occur at a negative transport-averaged temperature. Moreover, deep downwelling during the northeast monsoon occurs in the model because of a pattern of flow convergence at intermediate levels of the Somali Current that is consistent with direct observations. An approach reward assessing the location and the role of diabatic processes (which could be responsible for too deep a penetration of the downwelling cell) is tested, and a formal decomposition of the seasonal heat transport into diabatic and adiabatic components is suggested. Representing as a function of latitude and potential temperature an equivalent streamfunction associated with diffusion appears a promising step tow ard quantifying such diabatic heat transports on a seasonal basis. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Wacongne, S (reprint author), UNIV BRETAGNE OCCIDENTALE,FAC SCI & TECHNIQUES,LAB PHYS OCEANS,UMR,CNRS,6 AVE GORGEU,BP 809,F-29285 BREST,FRANCE. NR 55 TC 51 Z9 57 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD DEC PY 1996 VL 26 IS 12 BP 2666 EP 2699 DI 10.1175/1520-0485(1996)026<2666:SHTIAP>2.0.CO;2 PG 34 WC Oceanography SC Oceanography GA WC962 UT WOS:A1996WC96200007 ER PT J AU Kleinschuster, SJ Parent, J Walker, CW Farley, CA AF Kleinschuster, SJ Parent, J Walker, CW Farley, CA TI A cardiac cell line from Mya arenaria (Linnaeus, 1759) SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE M-arenaria; cell line; marine mollusc; tissue culture; proliferation AB Using standard tissue culture techniques, we report here the development of a cardiac cell line from Mya arenaria that exhibits anchorage dependency and an observable, high mitotic coefficient. The cultures can be subcultured while retaining reduced mitotic activity. C1 UNIV NEW HAMPSHIRE,DEPT ZOOL,DURHAM,NH 03824. NOAA,US DOC,NATL MARINE FISHERIES SERV,OXFORD,MD 21654. RP Kleinschuster, SJ (reprint author), HASKIN SHELLFISH RES LAB,PORT NORRIS,NJ 08349, USA. NR 8 TC 12 Z9 12 U1 1 U2 2 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 1996 VL 15 IS 3 BP 695 EP 707 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WB852 UT WOS:A1996WB85200023 ER PT J AU Druzhinin, OA Ostrovsky, LA Prosperetti, A AF Druzhinin, OA Ostrovsky, LA Prosperetti, A TI Low-frequency acoustic wave generation in a resonant bubble layer SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The nonlinear response of a bubble layer subject to harmonic and biharmonic excitation at frequencies smaller than the individual bubble resonance frequency is considered. The nonlinear resonance properties of the layer and generation of difference-frequency signal sire studied analytically and numerically. It is found that, for bubble volume fractions beta approximate to 10(-3) and pump amplitudes of the order of 10(-1) atm, the power of the low-frequency signal (including waves radiated in both directions) may reach 10% of the total power of the incident biharmonic wave. The efficiency is restricted by the rapid formation of shocks already at relatively low driving amplitudes, which may not occur in a more complete model accounting for the inertia of the bubble pulsations. (C) 1996 Acoustical Society of America. C1 UNIV COLORADO,CIRES,NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. INST PHYS APPL,BOULDER,CO 80303. JOHNS HOPKINS UNIV,DEPT MECH ENGN,BALTIMORE,MD 21218. RP Druzhinin, OA (reprint author), INST PHYS APPL,NIZHNII NOVGOROD 603600,RUSSIA. RI Prosperetti, Andrea/A-6263-2008; OI Prosperetti, Andrea/0000-0003-4129-7130; Ostrovsky, Lev/0000-0003-2233-1305 NR 10 TC 17 Z9 18 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1996 VL 100 IS 6 BP 3570 EP 3580 DI 10.1121/1.417222 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VX674 UT WOS:A1996VX67400010 ER PT J AU Xu, HHK Jahanmir, S Ives, LK Job, LS Ritchie, KT AF Xu, HHK Jahanmir, S Ives, LK Job, LS Ritchie, KT TI Short-crack toughness and abrasive machining of silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MATERIAL-REMOVAL; MECHANICAL-PROPERTIES; GRAIN-SIZE; CERAMICS; ALUMINA; CARBIDE; DAMAGE; MICROSTRUCTURE; COMPOSITES; TOLERANCE AB Hardness and toughness are often used to analyze the abrasive machining behavior of ceramic materials, However, toughness values of silicon nitride ceramics with microstructures containing elongated grains increase with crack extension, The present study investigates the effect of toughness on the process of abrasive machining to determine which value of toughness should be used in the analysis. The toughness curves (i.e., toughness as a function of crack length) of ten different silicon nitride materials are characterized by an indentation-strength technique and an indentation technique, The forces in surface grinding are measured as a function of the depth of cut, Examination of ground surfaces by scanning electron microscopy indicates that the material-removal processes in grinding follows the formation of short cracks (i.e., microcracks) and grain-scale material dislodgement. An indentation fracture model for material removal in abrasive machining is used to correlate the grinding forces with toughness and hardness of the materials. An agreement is obtained between the experimental results and the indentation model only when the toughness associated with short cracks is used. This study shows the importance of using appropriate toughness values corresponding to the microfracture processes in analyzing abrasive machining results for materials possessing rising toughness curves. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 32 TC 31 Z9 32 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD DEC PY 1996 VL 79 IS 12 BP 3055 EP 3064 DI 10.1111/j.1151-2916.1996.tb08077.x PG 10 WC Materials Science, Ceramics SC Materials Science GA WB443 UT WOS:A1996WB44300008 ER PT J AU Westphal, DL Kinne, S Pilewskie, P Alvarez, JM Minnis, P Young, DF Benjamin, SG Eberhard, WL Kropfli, RA Matrosov, SY Snider, JB Uttal, TA Heymsfield, AJ Mace, GG Melfi, SH Starr, DO Soden, JJ AF Westphal, DL Kinne, S Pilewskie, P Alvarez, JM Minnis, P Young, DF Benjamin, SG Eberhard, WL Kropfli, RA Matrosov, SY Snider, JB Uttal, TA Heymsfield, AJ Mace, GG Melfi, SH Starr, DO Soden, JJ TI Initialization and validation of a simulation of cirrus using FIRE-II data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID OCTOBER 1986; AIRCRAFT OBSERVATIONS; RADIATIVE PROPERTIES; OPTICAL-PROPERTIES; RAMAN LIDAR; WATER-VAPOR; CLOUDS; ICE; SENSITIVITY; ABSORPTION AB Observations from a wide variety of instruments and platforms are used to validate many different aspects of a three-dimensional mesoscale simulation of the dynamics, cloud microphysics, and radiative transfer of a cirrus cloud system observed on 26 November 1991 during the second cirrus field program of the First International Satellite Cloud Climatology Program (ISCCP) Regional Experiment (FIRE-II) located in southeastern Kansas. The simulation was made with a mesoscale dynamical model utilizing a simplified bulk water cloud scheme and a spectral model of radiative transfer. Expressions for cirrus optical properties for solar and infrared wavelength intervals as functions of ice water content and effective particle radius are modified for the midlatitude cirrus observed during FIRE II and are shown to compare favorably with explicit size-resolving calculations of the optical properties. Rawinsonde. Raman lidar, and satellite data are evaluated and combined to produce a time-height cross section of humidity at the central FIRE-II site for model verification. Due to the wide spacing of rawinsondes and their infrequent release, important moisture features go undetected and are absent in the con ventional analyses. The upper-tropospheric humidities used for the initial conditions were generally less than 50% of those inferred from satellite data, yet over the course of a 24-h simulation the model produced a distribution that closely resembles the large-scale features of the satellite analysis. The simulated distribution and concentration of ice compares favorably wi th data from radar, lidar, satellite, and aircraft. Direct comparison is made between the radiative transfer simulation and data from broadband and spectral sensors and inferred quantities such as cloud albedo, optical depth, and top-of-the atmosphere 11-mu m brightness temperature, and the 6.7-mu m brightness temperature. Comparison is also made with theoretical heating rates calculated using the rawinsonde data and measured ice water size distributions hear the central site. For this case study, and perhaps for most other mesoscale applications, the differences between the observed and simulated radiative quantities are due more to errors in the prediction of ice water content, than to errors in the optical properties or the radiative transfer solution technique. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NOAA,FSL,BOULDER,CO. NOAA,ETL,BOULDER,CO. NCAR,BOULDER,CO. PENN STATE UNIV,UNIVERSITY PK,PA 16802. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP Westphal, DL (reprint author), USN,RES LAB,7 GRACE HOPPER ST,STOP 2,MONTEREY,CA 94943, USA. RI Heymsfield, Andrew/E-7340-2011; Eberhard, Wynn/B-5402-2015; Benjamin, Stan/C-5818-2015; Minnis, Patrick/G-1902-2010 OI Benjamin, Stan/0000-0002-5751-8236; Minnis, Patrick/0000-0002-4733-6148 NR 49 TC 6 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1996 VL 53 IS 23 BP 3397 EP 3429 DI 10.1175/1520-0469(1996)053<3397:IAVOAS>2.0.CO;2 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX673 UT WOS:A1996VX67300001 ER PT J AU Stensrud, DJ AF Stensrud, DJ TI Effects of persistent, midlatitude mesoscale regions of convection on the large-scale environment during the warm season SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPOSPHERIC JET STREAK; TROPICAL SQUALL-LINE; NUMERICAL-SIMULATION; UNITED-STATES; WEATHER SYSTEMS; MODEL; COMPLEXES; CIRCULATION; PARAMETERIZATION; ATMOSPHERE AB Over a 2 1/2-day period beginning 0000 UTC 11 May 1982, 15 mesoscale convective systems (MCSs) developed and moved eastward across the moist axis located over the southern plains of the United States. While the 6-18-h lifetimes of each of these individual MCSs are not sufficiently long to influence the large-scale environment greatly, it is possible that the cumulative effects of the entire group of MCSs can produce significant changes in the large-scale flow patterns. This hypothesis is investigated using output from two runs of a sophisticated mesoscale model. One run includes the effects of convection, and the other does not. Results indicate that in low levels, the inflow of warm, moist air into the convective region is increased when convection is allowed in the model, enhancing the likelihood that convection will continue and thereby acting as a positive feedback mechanism. In upper levels, the convection acts as a Rossby wave source region and produces significant upper-level perturbations that cover at least a 50 degrees longitude spread. Convective effects also influence cyclogenesis since the MCSs strengthen the low-level baroclinicity and modify the phase relationship between pressure and thermal waves in the midlevels. Thus, it is clear that the effects of a persistent, mesoscale region of convection on the large-scale environment are substantial. RP Stensrud, DJ (reprint author), NOAA,ERL,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 67 TC 25 Z9 25 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1996 VL 53 IS 23 BP 3503 EP 3527 DI 10.1175/1520-0469(1996)053<3503:EOPMMR>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX673 UT WOS:A1996VX67300006 ER PT J AU Jin, Y Koch, SE Lin, YL Ralph, FM Chen, C AF Jin, Y Koch, SE Lin, YL Ralph, FM Chen, C TI Numerical simulations of an observed gravity current and gravity waves in an environment characterized by complex stratification and shear SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INTERACTING THUNDERSTORM OUTFLOWS; COORDINATE TRANSFORMATION; LABORATORY MODEL; DENSITY-CURRENT; DOPPLER RADAR; FLOW; LEVEL; WIND; DYNAMICS AB Numerical simulations of a gravity current in an environment characterized by complex stratification and vertical wind shear have been performed using a nonhydrostatic, two-dimensional, dry, primitive-equation model. Data from one of the most complete documentations to date of gravity waves associated with a gravity current, presented in an earlier study, are used both to prescribe the gravity current's environment and for validation of the simulated gravity current and its associated gravity waves. These comparisons indicate that the gravity current observed by a Doppler wind profiler and sodars was well simulated in terms of depth, density contrast, and propagation speed and that the model produced a variety of gravity waves similar in many ways to those observed. Because uncertainties remained concerning the gravity wave generation mechanisms derived from the observations (e.g., wavelengths were not observed), the validated simulations are used to test these tentative hypotheses. The simulations confirm that trapped lee-type gravity waves formed in response to flow over the head of the gravity current and that Kelvin-Helmholtz (KH) waves were created because of shear atop the cold air within the gravity current. The 2.8-km wavelength of the simulated KH waves agrees with the 2- to 3-km wavelength inferred from the observations. However, the 6.4-km wavelength of the simulated lee-type waves is significantly shorter than the 12.5-km wavelength inferred from the observational data, even though wave periods (20-23 minutes) are nearly identical. Sensitivity tests indicate that the curvature in the wind profile associated with the low-level opposing inflow and an elevated isothermal layer worked together to support the development of the trapped lee-type waves. The model produces a deep vertically propagating wave above the gravity current head that was not present in the observations. As deduced in the earlier study, sensitivity tests indicate that the prefrontal, near-surface stable layer was too shallow to support the generation of a bore; that is, conditions were supercritical. Synthesis of detailed observations and numerical simulations of these mesoscale phenomena thus offers the broadest examination possible of the complex physical processes. C1 N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695. NOAA,ERL,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. SCI SYST & APPLICAT INC,LANHAM,MD. NR 44 TC 23 Z9 23 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1996 VL 53 IS 23 BP 3570 EP 3588 DI 10.1175/1520-0469(1996)053<3570:NSOAOG>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX673 UT WOS:A1996VX67300010 ER PT J AU Ohno, Y AF Ohno, Y TI Realization of NIST 1995 luminous flux scale using the integrating sphere method SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article; Proceedings Paper CT 1995 IESNA Annual Conference CY 1995 CL NEW YORK, NY SP Illuminating Engn Soc N Amer AB A new NIST luminous flux scale has been realized using the integrating sphere method, on which theoretical and experimental studies were previously conducted and reported. The NIST 2 m integrating sphere was modified to add an opening and an additional baffle to apply this method. Flux fr om an external source (1000 W quartz halogen lamp) was introduced into the sphere through a limiting aperture and the opening. The flux entering the sphere was determined from the measured area of the aperture and the illuminance on the aperture plane measured with the NIST standard photometers that maintain the NIST illuminance scale. The total luminous flux of a group of standard lamps measured inside the sphere was deduced by comparison to the flux from the external source. Corrections were made for the spatial nonuniformity and the incident angle dependence of the sphere response, and the spectral mismatch of the integrating sphere photometer responsivity. The total luminous flux measured with the integrating sphere system was compared to the values obtained with a goniophotometer of PTB, Germany. The values obtained by the two methods agreed to within 0.2 percent. The magnitude of the new NIST luminous flux unit was 1.1 percent larger than previously realized. The relative expanded uncertainty (k=2) of the NIST luminous flux scale is now 0.5 percent. RP Ohno, Y (reprint author), NATL INST STAND & TECHNOL,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 16 TC 15 Z9 15 U1 0 U2 1 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD WIN PY 1996 VL 25 IS 1 BP 13 EP & PG 9 WC Optics SC Optics GA UA888 UT WOS:A1996UA88800006 ER PT J AU Ohno, Y AF Ohno, Y TI Realization of NIST 1995 luminous flux scale using the integrating sphere method - Response SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material RP Ohno, Y (reprint author), NATL INST STAND & TECHNOL,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD WIN PY 1996 VL 25 IS 1 BP 21 EP 22 PG 2 WC Optics SC Optics GA UA888 UT WOS:A1996UA88800010 ER PT J AU Collins, BL AF Collins, BL TI The influence of spectral composition on discomfort glare for large-size sources - Discussion SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material RP Collins, BL (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD WIN PY 1996 VL 25 IS 1 BP 40 EP 41 PG 2 WC Optics SC Optics GA UA888 UT WOS:A1996UA88800017 ER PT J AU Hulston, JR Lupton, JE AF Hulston, JR Lupton, JE TI Helium isotope studies of geothermal fields in the Taupo Volcanic Zone, New Zealand SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE geothermal fields; helium isotopes; Taupo Volcanic Zone; He-3/He-4 ratio; He/Ar ratios ID YELLOWSTONE-NATIONAL-PARK; ARC TECTONICS; NOBLE-GASES; RATIOS; SYSTEM; MANTLE; HE-3; EVOLUTION; WATERS; FLUIDS AB We report new measurements of He-3, He-4 and Ne on 69 samples of gas from geothermal fields in the central section of the NE-SW trending Taupo Volcanic Zone (TVZ). We find He-3/He-4 ratios in the range 5.9-7.3 times the atmospheric ratio (5.9-7.3R(A)), typical of subduction zone systems. In some areas near the boundaries of the volcanic zone the ratio is much lower (2-4R(A)). The values in the Wairakei field are extremely uniform and vary by only a few per cent from 7.2R(A). In contrast, the wells in the Ohaaki-Broadlands field show a striking factor of two variation, with the 'West bank' section characterised by values near 6 R(A) while the 'East bank' section has values as low as 3.0 R(A). This suggests that mixing of two types of geothermal source fluids may be occurring at Ohaaki-Broadlands. An inverse relationship has been found between the He-3/He-4 ratio of the gases and the B/Cl ratios in the associated fluids. Thus the helium isotope ratios appear to be affected both by the flux of mantle helium associated with mantle subduction and also by the presence of sedimentary rocks beneath the geothermal field. Leaching, by the hot ascending fluid, of radiogenic He-4 together with boron from the underlying high-boron, low-chloride Mesozoic greywacke basement, is thought to be the cause of this inverse relationship. The CO2/He-3 ratio in the TVZ exceeds the MORE ratio by a factor of up to 100, with higher values corresponding to higher B/Cl fluid ratios, suggesting that the greywacke may also be the major source of the CO2. We have also measured argon concentrations and isotopes on 19 samples in the Ohaaki-Broadlands area in order to further elucidate the nature of the striking helium isotope variations. The argon isotope ratios are relatively close to atmospheric indicating that the majority of the argon comes from recirculated groundwater. The simplified boiling model of Mazer et al. (1990) has been used to calculate the He-3/heat ratio in the Ohaaki-Broadlands and Wairakei fields. The values obtained fall within the range previously reported for mid-ocean ridge systems. This model has been extended and has led us to the conclusion that, compared to the He-3/He-4 ratio, the (He-3/Ar-36)(ASW) ratio is a much better indicator of the potential geothermal heat. The (He-4/Ar-10)(NA) (where NA = non-atmospheric) ratio of both the high (mantle-derived) and low (crustal-derived) He-3/He-4 end-members of the analyses reported here is about 3.6, but for samples with low He-3/Ar-36 ratio, this ratio falls to values below 0.5. The value of 3.6 is in the range which is expected for the radiogenic component and although considerably lower than that often found in subduction type mantle gases it is still within the accepted range of values. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. RP Hulston, JR (reprint author), INST GEOL & NUCL SCI,LOWER HUTT,NEW ZEALAND. NR 42 TC 27 Z9 27 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC PY 1996 VL 74 IS 3-4 BP 297 EP 321 DI 10.1016/S0377-0273(96)00031-5 PG 25 WC Geosciences, Multidisciplinary SC Geology GA VZ615 UT WOS:A1996VZ61500008 ER PT J AU Fox, CG AF Fox, CG TI Objective classification of oceanic ridge-crest terrains using two-dimensional spectral models of bathymetry: Application to the Juan de Fuca Ridge SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article DE geomorphology; Juan de Fuca Ridge; roughness; spectral analysis; clustering ID NORTHEAST PACIFIC; SEAFLOOR TOPOGRAPHY; FLOOR TOPOGRAPHY; MORPHOLOGY; ROUGHNESS AB An important application of detailed bathymetric mapping is the interpretation of geological processes based on the nature of the fine-scale morphology of the seafloor. This interpretation is usually accomplished through qualitative analysis of contour maps. In this paper, an objective classification technique, based on a two-dimensional spectral model of bathymetry developed by Fox and Hayes (1985) is applied to detailed Sea Beam data from the Juan de Fuca Ridge. Parameters of the model can be directly related to seafloor properties corresponding to 1) isotropic (non-directionally dependent) roughness; 2) anisotropic (directionally dependent) roughness; 3) orientation of the anisotropic component; and 4) spectral roll-off (similar to fractal dimension), by fitting the model surface to two-dimensional amplitude spectra of bathymetry determined on a regular grid over the study area. A test area was selected which encompasses the southern volcanic rift zone of Axial Volcano and the northern terminus of the Vance Segment. Parameters of the model clearly define the contrast between the constructional volcanic terrain (rough, isotropic, with high fractal dimension) and the tectonic extensional terrain (smoother, anisotropic, with low fractal dimension). An agglomerative, hierarchical cluster analysis is applied to the data, independent of spatial information, to delineate groups of spectra with similar characteristics. Distinct, mappable regions, corresponding to volcanic and tectonic provinces, are objectively determined. Also, coherent sub-regions of consistent spectral properties occur within the larger volcanic/tectonic divisions. The classification is extended to the Juan de Fuca Ridge system from 44 degrees 30' N to 47 degrees 20'N through combining these results with an a priori technique (K-means clustering). Broad-scale physiographic regions of the Juan de Fuca Ridge are delineated by the technique, which may aid geologists in the interpretation of crustal accretion processes at seafloor spreading centers. RP Fox, CG (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 30 TC 5 Z9 6 U1 0 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0025-3235 J9 MAR GEOPHYS RES JI Mar. Geophys. Res. PD DEC PY 1996 VL 18 IS 6 BP 707 EP 728 DI 10.1007/BF00313882 PG 22 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA VW680 UT WOS:A1996VW68000007 ER PT J AU Leshkevich, GA Schwab, DJ Muhr, GC AF Leshkevich, GA Schwab, DJ Muhr, GC TI Satellite environmental monitoring of the Great Lakes: Great Lakes CoastWatch Program update SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB As the CoastWatch regional node for the Great Lakes, the Great Lakes Environmental Research Laboratory (GLERL) obtains, processes, and delivers environmental data and products for the user community. GLERL provides access to near real-time satellite observations and in situ data for the Great Lakes to 41 federal, state, and local agencies and academic institutions. The goals and objectives of the CoastWatch Program directly support NOAA statutory responsibilities in estuarine and marine science, living marine resource protection, and ecosystem monitoring and manage ment. A digital image product suite of 26 images from the NOAA-12, NOAA-14, and GOES 8 satellites is currently being received. Over 32,000 image products have been received and archived since 1990. In addition, in situ and modeled data, including marine and meteorological observations and water level gauge measurements, are also routinely received and made available via dial-in modem or Internet. A new product developed at GLERL, the Great Lakes Surface Environmental Analysis (GLSEA), is a cloud-free, composited surface temperature chart that will include an ice cover analysis overlay during winter months. It is available to CoastWatch data users and is also on the World Wide Web. RP Leshkevich, GA (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. RI Schwab, David/B-7498-2012 NR 16 TC 3 Z9 3 U1 0 U2 2 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD WIN PY 1996 VL 30 IS 4 BP 28 EP 35 PG 8 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA WW785 UT WOS:A1996WW78500005 ER PT J AU Tseng, WF ChandlerHorowitz, D Papanicolaou, NA Boos, JB AF Tseng, WF ChandlerHorowitz, D Papanicolaou, NA Boos, JB TI Interdigitated hetero InGaAs/GaAs n-i-p-i modulators SO MATERIALS LETTERS LA English DT Article DE interdigitated; shadow mask; n-i-p-i heterostructure; modulators; InGaAs/GaAs; MBE; semiconductors; electro-optic ID SHADOW MASK AB Interdigitated hetero InGaAs n-i-p-i InGaAs/GaAs modulators have been grown and fabricated by a shadow mask technique for selectively making contacts to n-and p-layers. Manipulations of exciton peak positions and intensities by external electrical bias and incident optical power have been demonstrated. C1 USN,RES LAB,DIV ELECT SCI & TECHNOL,WASHINGTON,DC 20375. RP Tseng, WF (reprint author), NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD DEC PY 1996 VL 29 IS 4-6 BP 249 EP 253 DI 10.1016/S0167-577X(96)00152-8 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VZ827 UT WOS:A1996VZ82700011 ER PT J AU Barnes, GM Fankhauser, JC Browning, WD AF Barnes, GM Fankhauser, JC Browning, WD TI Evolution of the vertical mass flux and diagnosed net lateral mixing in isolated convective clouds SO MONTHLY WEATHER REVIEW LA English DT Article ID CUMULUS CONGESTUS CLOUDS; ENVIRONMENT INTERFACE; OCEANIC CONVECTION; SOUTH FLORIDA; ENTRAINMENT; DYNAMICS; UPDRAFT; AIRCRAFT; VELOCITY; MODEL AB The evolution of the vertical mass flux in isolated cumulus and cumulus congestus clouds is documented using two King Airs during the Convection and Precipitation/Electrification Experiment (CaPE), conducted in east-central Florida during the summer of 1991. These clouds develop over the sea-breeze convergence in an environment characterized by low shear and moderate convective available potential energy. The aircraft, separated vertically by 600-1000 m, commence flying near-simultaneous penetrations as the cloud top passes through the altitude of the upper aircraft and continue sampling until the cloud disappears. The net vertical mass Bur for each level is estimated: the difference in the mass Bur between the two levels leads to a diagnosis of the net entrainment or detrainment that occurs laterally in the intervening cloud layer. This kinematic technique relies on determination of cloud edge based on liquid water measurements, a cloud shape factor, and the vertical velocity. The technique is not Limited to the period prior to precipitation fall out like most conserved variable techniques nor does it require accurate measurement of in-cloud total water and temperature. Results from 12 isolated clouds with radii of 0.5-1.5 km and lifetimes less than 25 min demonstrate that the vertical mass hull evolves in a well-behaved manner with clear growth and decay phases. Significant net lateral entrainment or detrainment is diagnosed, which complements the top entrainment that has been inferred from conserved thermodynamic variable techniques, Net entrainment dominates the growth stage, whereas net detrainment is most often seen during the decay stage of the cloud. An approximate entrainment rate averaged over cloud life is 1 km(-1). The continuous nature of the updrafts demonstrates that these small clouds are best described as a single shedding thermal, not a series of bubbles ascending in the wake of each preceding bubble. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NATL WEATHER SERV,MILWAUKEE,WI. RP Barnes, GM (reprint author), UNIV HAWAII MANOA,DEPT METEOROL,HONOLULU,HI 96822, USA. NR 71 TC 14 Z9 14 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1996 VL 124 IS 12 BP 2764 EP 2784 DI 10.1175/1520-0493(1996)124<2764:EOTVMF>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ340 UT WOS:A1996VZ34000007 ER PT J AU Bandyopadhyay, S Miller, AE Chang, HC Banerjee, G Yuzhakov, V Yue, DF Ricker, RE Jones, S Eastman, JA Baugher, E Chandrasekhar, M AF Bandyopadhyay, S Miller, AE Chang, HC Banerjee, G Yuzhakov, V Yue, DF Ricker, RE Jones, S Eastman, JA Baugher, E Chandrasekhar, M TI Electrochemically assembled quasi-periodic quantum dot arrays SO NANOTECHNOLOGY LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Ordered Molecular and Nanoscale Electronics CY JUN, 1994 CL KEAUHOU KONA, HI SP Off Naval Res, Adv Res Proj Agcy ID BEAM-INDUCED DAMAGE; POROUS SILICON; GAAS; HETEROSTRUCTURES; FABRICATION AB We describe two electrochemical self-assembly processes for producing highly ordered quasi-periodic arrays of quantum dots on a surface. The advantages of these techniques are: (i) they are 'gentle' and do not cause radiation damage to nanostructures unlike beam lithography, (ii) they have high throughput and are amenable to mass production unlike direct-write lithography, (iii) structures can be delineated on non-planar substrates, and (iv) the techniques are potentially orders of magnitude cheaper to implement than conventional nanosynthesis. Samples produced by these techniques have been characterized by microscopy, optical and transport measurements, Auger and x-ray. These measurements reveal intriguing properties of the nanostructures. In this paper, we describe our initial results and show the promise of such techniques for low-cost and high-yield nanosynthesis. C1 UNIV NOTRE DAME,DEPT CHEM ENGN,NOTRE DAME,IN 46566. SGS THOMSON MICROELECT,CARROLLTON,TX 75006. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV MISSOURI,DEPT PHYS,COLUMBIA,MO 65211. RP Bandyopadhyay, S (reprint author), UNIV NEBRASKA,DEPT ELECT ENGN,LINCOLN,NE 68588, USA. RI Eastman, Jeffrey/E-4380-2011; Ricker, Richard/H-4880-2011; Chang, Hsueh-Chia/E-8048-2012; OI Ricker, Richard/0000-0002-2871-4908; Eastman, Jeff/0000-0002-0847-4265 NR 37 TC 122 Z9 125 U1 0 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC PY 1996 VL 7 IS 4 BP 360 EP 371 DI 10.1088/0957-4484/7/4/010 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA WN781 UT WOS:A1996WN78100010 ER PT J AU Hill, MD Blendell, JE Bennett, LH AF Hill, MD Blendell, JE Bennett, LH TI Reduced microcrack density in melt processed (Y,Sm)Ba2Cu3O6+x SO PHYSICA C LA English DT Article ID HIGH-TEMPERATURE; SUPERCONDUCTORS; YBA2CU3OX; SYSTEM; JC AB The microcrack density in melt processed YBa2Cu3O6+x was reduced by maintaining the tetragonal phase during cooling to room temperature with subsequent oxidation to form the orthorhombic phase. The effect of microcrack reduction on the magnetic critical current density (J(c)) of YBa2Cu3O6+x was determined. Melt processing at 1100 degrees C with a mole fraction of 5% Sm2BaCuO5 addition and a two step annealing process yielded the highest magnetic critical current density. Processing at 1050 degrees C resulted in a decrease in both the grain size and the magnetic J(c). C1 NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV MET,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 10 TC 3 Z9 3 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 DEC 1 PY 1996 VL 272 IS 3-4 BP 204 EP 208 DI 10.1016/S0921-4534(96)00602-8 PG 5 WC Physics, Applied SC Physics GA WA265 UT WOS:A1996WA26500005 ER PT J AU Bohn, JL Julienne, PS AF Bohn, JL Julienne, PS TI Semianalytic treatment of two-color photoassociation spectroscopy and control of cold atoms SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM-DEFECT THEORY; GENERAL-FORM; SCATTERING AB We present semianalytic expressions for scattering probabilities of cold trapped atoms in the presence of two weak, independently tunable laser fields, both tuned near molecular resonances. We consider two experimental situations. In the first, an Autler-Townes doublet appears and is shown in certain circumstances to exhibit unequal peak heights. In the second, the pair of lasers is employed to produce translationally cold ground-state molecules, in which case our formula suggests the optimal conditions for such production. C1 NATL INST STAND & TECHNOL,QUANTUM PHYS DIV,BOULDER,CO 80309. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Bohn, JL (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 16 TC 69 Z9 69 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1996 VL 54 IS 6 BP R4637 EP R4640 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VX714 UT WOS:A1996VX71400010 ER PT J AU Bollinger, JJ Itano, WM Wineland, DJ Heinzen, DJ AF Bollinger, JJ Itano, WM Wineland, DJ Heinzen, DJ TI Optimal frequency measurements with maximally correlated states SO PHYSICAL REVIEW A LA English DT Article ID PRECISION-MEASUREMENT; PROJECTION NOISE; ATOMIC STATES; QUANTUM; PHASE; IONS; INTERFEROMETER; SPECTROSCOPY; SYSTEMS; LIMIT AB We show how maximally correlated states of N two-level particles can be used in spectroscopy to yield a frequency uncertainty equal to (NT)(-1), where T is the time of a single measurement. From the time-energy uncertainty relation we show that this is the best precision possible. We rephrase these results in the language of particle interferometry and obtain a state and detection operator which can be used to achieve a phase uncertainty exactly equal to the 1/N Heisenberg limit, where N is the number of particles used in the measurement. C1 UNIV TEXAS, DEPT PHYS, AUSTIN, TX 78712 USA. RP Bollinger, JJ (reprint author), NATL INST STAND & TECHNOL, DIV TIME & FREQUENCY, BOULDER, CO 80303 USA. NR 32 TC 564 Z9 566 U1 4 U2 21 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1996 VL 54 IS 6 BP R4649 EP R4652 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VX714 UT WOS:A1996VX71400013 ER PT J AU Mueller, DR Ederer, DL vanEk, J OBrien, WL Dong, QY Jia, JJ Callcott, TA AF Mueller, DR Ederer, DL vanEk, J OBrien, WL Dong, QY Jia, JJ Callcott, TA TI Soft-x-ray emission and the local p-type partial density of electronic states in Y2O3: Experiment and theory SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON LIGHT-SOURCE; YTTRIUM-OXIDE; MONOCHROMATOR; EXCITATION AB Photon-excited yttrium M(IV,V), and electron-excited oxygen K x-ray emission spectra for yttrium oxide are presented. It is shown that as in the case of yttrium metal, the decay of M(IV) vacancies does not contribute substantially to the oxide M(IV,V) emission. The valence emission is interpreted in a one-electron picture as a measure of the local p-type partial density of states. The yttrium and oxygen valence emission bands are very similar and strongly resemble published photoelectrons spectra. Using local-density approximation electronic structure calculations, we show that the broadening of the Y-4p signal in yttrium oxide relative to Y metal are due to two inequivalent yttrium sites in Y2O3. Features present in the oxide, but not the metal spectrum, are the result of overlap (hybridization) between the Y-4p wave function and states in the oxygen 2s subband. C1 TULANE UNIV,NEW ORLEANS,LA 70118. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Mueller, DR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 22 TC 18 Z9 18 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1996 VL 54 IS 21 BP 15034 EP 15039 DI 10.1103/PhysRevB.54.15034 PG 6 WC Physics, Condensed Matter SC Physics GA VY201 UT WOS:A1996VY20100039 ER PT J AU Castellano, MG Torrioli, G Cosmelli, C Costantini, A Chiarello, F Carelli, P Rotoli, G Cirillo, M Kautz, RL AF Castellano, MG Torrioli, G Cosmelli, C Costantini, A Chiarello, F Carelli, P Rotoli, G Cirillo, M Kautz, RL TI Thermally activated escape from the zero-voltage state in long Josephson junctions SO PHYSICAL REVIEW B LA English DT Article ID SINE-GORDON MODEL; SUPERCURRENT DECAY; DC-SQUID; LEVEL QUANTIZATION; TUNNEL-JUNCTIONS; DISSIPATION; TEMPERATURE; DYNAMICS; BARRIER AB We have measured the rate of thermally induced escape from the zero-voltage state in long Josephson junctions of both overlap and in-line geometry as a function of applied magnetic field. The statistical distribution of switching currents is used to evaluate the escape rate and derive an activation energy Delta U for the process. Because long junctions correspond to the continuum limit of multidimensional systems, Delta U is in principle the difference in energy between stationary states in an infinite-dimensional potential. We obtain good agreement between calculated and measured activation energies for junctions with lengths a few times the Josephson penetration depth lambda(J). C1 UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. UNIV AQUILA, DIPARTIMENTO ENERGET, I-67040 LAQUILA, ITALY. UNIV ROMA TOR VERGATA, DIPARTIMENTO FIS, I-00133 ROME, ITALY. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. RP CNR, IST ELETTR STATO SOLIDO, VIA CINETO ROMANO 42, I-00156 ROME, ITALY. RI Rotoli, Giacomo/E-4718-2011; Castellano, Maria Gabriella/C-4509-2009; Chiarello, Fabio/B-8423-2009 OI Rotoli, Giacomo/0000-0002-2331-8949; Castellano, Maria Gabriella/0000-0002-9764-0746; Chiarello, Fabio/0000-0002-7487-2827 NR 46 TC 46 Z9 46 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1996 VL 54 IS 21 BP 15417 EP 15428 DI 10.1103/PhysRevB.54.15417 PG 12 WC Physics, Condensed Matter SC Physics GA VY201 UT WOS:A1996VY20100088 ER PT J AU Anthony, PL Arnold, RG Band, HR Borel, H Bosted, PE Breton, V Cates, GD Chupp, TE Dietrich, FS Dunne, J Erbacher, R Fellbaum, J Fonvieille, H Gearhart, R Holmes, R Hughes, EW Johnson, JR Kawall, D Keppel, C Kuhn, SE LombardNelsen, RM Marroncle, J Maruyama, T Meyer, W Meziani, ZE Middleton, H Morgenstern, J Newbury, NR Petratos, GG Pitthan, R Prepost, R Roblin, Y Rock, SE Rokni, SH Shapiro, G Smith, T Souder, PA Spengos, M Staley, F Stuart, LM Szalata, ZM Terrien, Y Thompson, AK White, JL Woods, M Xu, J Young, CC Zapalac, G AF Anthony, PL Arnold, RG Band, HR Borel, H Bosted, PE Breton, V Cates, GD Chupp, TE Dietrich, FS Dunne, J Erbacher, R Fellbaum, J Fonvieille, H Gearhart, R Holmes, R Hughes, EW Johnson, JR Kawall, D Keppel, C Kuhn, SE LombardNelsen, RM Marroncle, J Maruyama, T Meyer, W Meziani, ZE Middleton, H Morgenstern, J Newbury, NR Petratos, GG Pitthan, R Prepost, R Roblin, Y Rock, SE Rokni, SH Shapiro, G Smith, T Souder, PA Spengos, M Staley, F Stuart, LM Szalata, ZM Terrien, Y Thompson, AK White, JL Woods, M Xu, J Young, CC Zapalac, G TI Deep inelastic scattering of polarized electrons by polarized He-3 and the study of the neutron spin structure SO PHYSICAL REVIEW D LA English DT Review ID STRUCTURE-FUNCTION G1(X); SUM-RULE; HIGH-DENSITY; PRECISION-MEASUREMENT; MOLLER POLARIMETER; CROSS-SECTIONS; PROTON; DEUTERON; RELAXATION; NUCLEONS AB The neutron longitudinal and transverse asymmetries A(1)(n) and A(2)(n) have been extracted from deep inelastic scattering of polarized electrons by a polarized He-3 target at incident energies of 19.42, 22.66, and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions g(1)(n)(x,Q(2)) and g(2)*(x,Q(2)) over the range 0.032.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100005 ER PT J AU Barnston, AG Thiao, W Kumar, V AF Barnston, AG Thiao, W Kumar, V TI Long-lead forecasts of seasonal precipitation in Africa using CCA SO WEATHER AND FORECASTING LA English DT Article ID NINO-SOUTHERN OSCILLATION; CANONICAL CORRELATION-ANALYSIS; SURFACE AIR TEMPERATURES; NORTHERN-HEMISPHERE; STATISTICAL-MODELS; PREDICTION; CLIMATE; SKILL; OCEAN; RAINFALL AB A potentially operational forecast system for 3-month total precipitation for three sections of the African continent has been developed at NOAA's Climate Prediction Center using the statistical method of canonical correlation analysis (CCA). The levels and sources of predictive skills have been explored at lead times of up to 1 year, using a cross-validation design. The predictor field is quasi-global sea surface temperature (SST). Four consecutive 3-month predictor periods are used to detect evolving as well as steady-state SST conditions. Low to modest forecast skills are found for most regions and seasons of the year. However, moderate skills (correlation > 0.5) are found for parts of northern tropical Africa (the Sahel) for lead times of up to several seasons in its July-August-September rainy season. CCA generally outperforms persistence, even at short lead times. The El Nino-Southern Oscillation (ENSO) phenomenon is found to play some role in the precipitation variability in all three African regions: Warm SO episodes tend to suppress northern summer rainfall in the Sahel and southern summer rainfall in portions of southern Africa, and possibly enhance rainfall at a very limited number of eastern African stations in their two rainy seasons (March-April-May and October-November-December). However, ENSO does not determine precipitation in any part of Africa nearly as strongly as it does for regions closer to the tropical Pacific. Other major sources of predictive skill include interdecadal regimes and still longer term trends. A decadal change toward Sahel dryness began in the 1970s in association with increased SST in the Indian, South Atlantic, and eastern tropical Pacific Oceans. A more gradual Sahelian drying has paralleled a warming (cooling) of the Southern (Northern) Hemisphere SST, particularly in the Atlantic. Parts of southern Africa's summer rainfall is enhanced by positive SST anomalies in the adjacent South Atlantic and southwest Indian Oceans but suppressed by generalized warm worldwide SST. Wet season rainfall at a small minority of stations in eastern Africa is increased by positive SST anomalies in the upwind western Indian Ocean. While African forecast skills are generally modest, operational issuance of forecasts and their expected skills could begin by 1997 for seasons and locations for which skill is usable. RP Barnston, AG (reprint author), NOAA,NATL WEATHER SERV,CLIMATE PREDICT CTR,NATL CTR ENVIRONM PREDICT,WNP51,WWB ROOM 604,WASHINGTON,DC 20233, USA. NR 34 TC 46 Z9 50 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1996 VL 11 IS 4 BP 506 EP 520 DI 10.1175/1520-0434(1996)011<0506:LLFOSP>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100006 ER PT J AU Gyakum, JR Carrera, M Zhang, DL Miller, S Caveen, J Benoit, R Black, T Buzzi, A Chouinard, C Fantini, M Folloni, C Katzfey, JJ Kuo, YH Lalaurette, F LowNam, S Mailhot, J Malguzzi, P McGregor, JL Nakamura, M Tripoli, G Wilson, C AF Gyakum, JR Carrera, M Zhang, DL Miller, S Caveen, J Benoit, R Black, T Buzzi, A Chouinard, C Fantini, M Folloni, C Katzfey, JJ Kuo, YH Lalaurette, F LowNam, S Mailhot, J Malguzzi, P McGregor, JL Nakamura, M Tripoli, G Wilson, C TI A regional model intercomparison using a case of explosive oceanic cyclogenesis SO WEATHER AND FORECASTING LA English DT Article ID NATIONAL-METEOROLOGICAL-CENTER; DIABATIC INITIALIZATION; SENSITIVITY EXPERIMENTS; CUMULUS CONVECTION; WEATHER PREDICTION; SYSTEMATIC-ERRORS; BOUNDARY-LAYER; ATLANTIC-OCEAN; FORECAST MODEL; SATELLITE DATA AB The authors evaluate the performance of current regional models in an intercomparison project for a case of explosive secondary marine cyclogenesis occurring during the Canadian Atlantic Storms Project and the Genesis of Atlantic Lows Experiment of 1986. Several systematic errors are found that have been identified in the refereed literature id prior years. There is a high (low) sea level pressure bias and a cold (warm) tropospheric temperature error in the oceanic (continental) regions. Though individual model participants produce central pressures of the secondary cyclone close to the observed during the final stages of its life cycle, systematically weak systems are simulated during the critical early stages of the cyclogenesis; Additionally, the simulations produce an excessively weak (strong) continental anticyclone (cyclone); implications of these errors are discussed in terms of the secondary cyclogenesis. Little relationship between strong performance in predicting the mass held and skill in predicting a measurable amount of precipitation is found. The bias scores in the precipitation study indicate a tendency for all models to overforecast precipitation. Results for the measurable threshold (0.2 mm) indicate the largest gain in precipitation scores results from increasing the horizontal resolution from 100 to 50 km, with a negligible benefit occurring as a consequence of increasing the resolution from 50 to 25 km. The importance of a horizontal resolution increase from 100 to 50 km is also generally shown for the errors in the mass field. However, little improvement in the prediction of the cyclogenesis is found by increasing the horizontal resolution from 50 to 25 km. C1 ATMOSPHER ENVIRONM SERV, MARITIMES WEATHER CTR, BEDFORD, NS, CANADA. ATMOSPHER ENVIRONM SERV, DORVAL, PQ, CANADA. NATL CTR ENVIRONM PREDICT, CAMP SPRINGS, MD USA. FISBAT INST, NATL RES COUNCIL ITALY, BOLOGNA, ITALY. ATMOSPHER ENVIRONM SERV, DATA ASSIMILAT & SATELLITE METEOROL DIV, DORVAL, PQ, CANADA. COMMONWEALTH SCI & IND RES ORG, VICTORIA, AUSTRALIA. METEO FRANCE, TOULOUSE, FRANCE. JAPAN METEOROL AGCY, TOKYO, JAPAN. UNIV WISCONSIN, DEPT ATMOSPHER & OCEAN SCI, MADISON, WI USA. METEOROL OFF, BRACKNELL RB12 2SZ, BERKS, ENGLAND. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. RP Gyakum, JR (reprint author), MCGILL UNIV, DEPT ATMOSPHER & OCEAN SCI, 805 SHERBROOK ST WEST, MONTREAL, PQ H3A 2K6, CANADA. RI Zhang, Da-Lin/F-2634-2010; Fantini, Maurizio/H-4871-2011; McGregor, John/C-6646-2012; Katzfey, Jack/K-1231-2012; Malguzzi, Piero/O-1723-2015 OI Zhang, Da-Lin/0000-0003-1725-283X; Fantini, Maurizio/0000-0003-0962-9190; Katzfey, Jack/0000-0002-0604-8860; Malguzzi, Piero/0000-0002-9544-0329 NR 58 TC 27 Z9 28 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 DEC PY 1996 VL 11 IS 4 BP 521 EP 543 DI 10.1175/1520-0434(1996)011<0521:ARMIUA>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100007 ER PT J AU Doswell, CA Brooks, HE Maddox, RA AF Doswell, CA Brooks, HE Maddox, RA TI Flash flood forecasting: An ingredients-based methodology SO WEATHER AND FORECASTING LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; LIFE-CYCLE; PRECIPITATION; SYSTEMS; PATTERNS; PLAINS; RADAR AB An approach to forecasting the potential for flash hood-producing storms is developed, using the notion of basic ingredients. Heavy precipitation is the result of sustained high rainfall rates. In turn, high rainfall rates involve the rapid ascent of air containing substantial water vapor and also depend on the precipitation efficiency. The duration of an event is associated with its speed of movement and the size of the system causing the event along the direction of system movement. This leads naturally to a consideration of the meteorological processes by which these basic ingredients are brought together. A description of those processes and of the types of heavy precipitation-producing storms suggests some of the variety of ways in which heavy precipitation occurs. Since the right mixture of these ingredients can he found in a wide variety of synoptic and mesoscale situations, it is necessary to know which of the ingredients is critical in any given case. By knowing which of the ingredients is most important in any given case, forecasters can concentrate on recognition of the developing heavy precipitation potential as meteorological processes operate. This also helps with the recognition of heavy rain events as they occur, a challenging problem if the potential for such events has not been anticipated. Three brief case examples are presented to illustrate the procedure as it might he applied in operations. The cases are geographically diverse and even illustrate how a nonconvective heavy precipitation event fits within this methodology. The concept of ingredients-based forecasting is discussed as it might apply to a broader spectrum of forecast events than just Bash hood forecasting. RP Doswell, CA (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 45 TC 368 Z9 389 U1 7 U2 50 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1996 VL 11 IS 4 BP 560 EP 581 DI 10.1175/1520-0434(1996)011<0560:FFFAIB>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100009 ER PT J AU Czys, RR Scott, RW Tang, KC Przybylinski, RW Sabones, ME AF Czys, RR Scott, RW Tang, KC Przybylinski, RW Sabones, ME TI A physically based, nondimensional parameter for discriminating between locations of freezing rain and ice pellets SO WEATHER AND FORECASTING LA English DT Article ID WINTER STORMS; MESOSCALE; PRECIPITATION AB A nondimensional parameter is presented that can be used to help distinguish between conditions favorable for the occurrence of freezing rain and ice pellets. The parameter was derived from the well-established condition that most incidents of freezing rain and ice pellets are associated with a layer of above-freezing air elevated above a layer of below-freezing air adjacent to the earth's surface and the requirement that any cloud ice must completely melt for freezing rain, otherwise ice pellets would result. The parameter was obtained from the ratio of the time available for melting to the time required for complete melting. The parameter was tested on the mesoscale thermodynamic conditions that existed with the 1990 St. Valentine's Day ice storm that affected much of the Midwest and on a number of other episodes of freezing rain and ice pellets in the Midwest. Testing showed excellent spatial agreement between diagnosed and observed locations for freezing rain and ice pellets. An isonomogram is presented to allow the parameter to be easily used as a tool in determining winter precipitation type. C1 UNIV ILLINOIS,DEPT MECH & IND ENGN,URBANA,IL 61801. NOAA,NATL WEATHER SERV,FORECAST OFF,ST CHARLES,MO. NOAA,NATL WEATHER SERV,FORECAST OFF,INDIANAPOLIS,IN. RP Czys, RR (reprint author), ILLINOIS STATE WATER SURVEY,OFF CLOUD & PRECIPITAT RES,2204 GRIFFITH DR,CHAMPAIGN,IL 61820, USA. NR 40 TC 40 Z9 55 U1 3 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1996 VL 11 IS 4 BP 591 EP 598 DI 10.1175/1520-0434(1996)011<0591:APBNPF>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100011 ER PT J AU Holle, RL Watson, AI AF Holle, RL Watson, AI TI Lightning during two central US winter precipitation events SO WEATHER AND FORECASTING LA English DT Article ID CONDITIONAL SYMMETRICAL INSTABILITY; HEAVY SNOW AREAS; SATELLITE IMAGERY; FRONTAL SURFACES; UNITED-STATES; POSITIVE CAPE; THUNDERSTORMS; ENVIRONMENTS; LOCATIONS; WEATHER AB Network-detected cloud-to-ground lightning coincident with mainly frozen precipitation (freezing rain, sleet, snow) was studied over the central United States during two outbreaks of arctic air in January 1994. During the first event, the ratio of positive to total flashes was 59%, flashes were few and disorganized in area, and no surface observer reported thunder. For the other event the ratio was 52% during the first few hours in subfreezing surface air, then decreased when flashes formed in the nearby region above freezing. Also, flashes in this case were linearly aligned and coincided with conditional symmetric instability; thunder was heard infrequently by surface observers. On radar, reflectivity cores grew from weak to moderate intensity within a few hours of the lightning during both cases. Echo area increased greatly before flashes in one case, while the area increase coincided with flashes in the other. Some base-scan reflectivities were strong in both thunderstorm regions due to the radar beam intersecting the melting level. Regions with lightning often could be identified better by high echo tops than reflectivity. Analyses on the scale of one or two states diagnosed the strength of low-level warming that contributed to formation of thunderstorms and significant frozen precipitation. Quasigeostrophic analyses showed that 850-mb temperature advection and 850-500-mb differential vorticity advection were similar in magnitude in the lightning area during both events. Once convection formed, lightning and echo-top information identified downstream regions with a potential for subsequent frozen precipitation. RP Holle, RL (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 36 TC 19 Z9 22 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1996 VL 11 IS 4 BP 599 EP 614 DI 10.1175/1520-0434(1996)011<0599:LDTCUW>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VZ461 UT WOS:A1996VZ46100012 ER PT J AU Talukdar, RK Hunter, M Warren, RF Burkholder, JB Ravishankara, AR AF Talukdar, RK Hunter, M Warren, RF Burkholder, JB Ravishankara, AR TI UV laser photodissociation of CF2ClBr and CF2Br2 at 298 K: Quantum yields of Cl, Br, and CF2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID 193 NM; SPECTROSCOPY AB In the photodissociation of CF2ClBr, the quantum yields for Cl atom production were measured to be 1.03 +/- 0.14, 0.27 +/- 0.04, and 0.18 +/- 0.03, respectively, at 193, 222, and 248 nm, while those for Br atom were 1.04 +/- 0.13 at 193 nm, 0.86 +/- 0.11 at 222 nm, and 0.75 +/- 0.13 at 248 nm, Errors are 95% confidence limits and include estimated systematic errors, The CF2 quantum yields in 193 nm photolysis were measured to be 1.15 +/- 0.30 for CF2Br2 and 0.91 +/- 0.30 for CF2ClBr. These results indicate the quantum yield for photodissociation of CF2ClBr is unity. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Talukdar, RK (reprint author), NOAA,AERON LAB,325 BROADWAY,R-E-AL2,BOULDER,CO 80303, USA. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 15 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 29 PY 1996 VL 262 IS 6 BP 669 EP 674 DI 10.1016/S0009-2614(96)01157-8 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VV284 UT WOS:A1996VV28400001 ER PT J AU Picaut, J Ioualalen, M Menkes, C Delcroix, T McPhaden, MJ AF Picaut, J Ioualalen, M Menkes, C Delcroix, T McPhaden, MJ TI Mechanism of the zonal displacements of the Pacific warm pool: Implications for ENSO SO SCIENCE LA English DT Article ID SEA-SURFACE TEMPERATURE; EQUATORIAL PACIFIC; EL-NINO; SOUTHERN OSCILLATION; OCEAN; DYNAMICS; MODEL; ANOMALIES; SALINITY; CLIMATE AB The western equatorial Pacific warm pool is subject to strong east-west migrations on interannual time scales in phase with the Southern Oscillation Index. The dominance of surface zonal advection in this migration is demonstrated with four different current data sets and three ocean models. The eastward advection of warm and less saline water from the western Pacific together with the westward advection of cold and more saline water from the central-eastern Pacific induces a convergence of water masses at the eastern edge of the warm pool and a well-defined salinity front. The location of this convergence is zonally displaced in association with El Nino-La Nina wind-driven surface current variations. These advective processes and water-mass convergences have significant implications for understanding and simulating coupled ocean-atmosphere interactions associated with El Nino-Southern Oscillation (ENSO). C1 ORSTOM,CTR RECH OCEANOG,ABIDJAN,COTE IVOIRE. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Picaut, J (reprint author), ORSTOM,INST FRANCAIS RECH SCI DEV COOPERAT,GRP SURTROPAC,BP A5,NOUMEA 98848,NEW CALEDONIA. RI McPhaden, Michael/D-9799-2016; Delcroix, Thierry/I-6103-2016; menkes, christophe/H-9085-2016 OI Delcroix, Thierry/0000-0002-8850-4865; menkes, christophe/0000-0002-1457-9696 NR 34 TC 242 Z9 255 U1 3 U2 28 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 29 PY 1996 VL 274 IS 5292 BP 1486 EP 1489 DI 10.1126/science.274.5292.1486 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV775 UT WOS:A1996VV77500035 ER PT J AU Langford, AO Proffitt, MH VanZandt, TE Lamarque, JF AF Langford, AO Proffitt, MH VanZandt, TE Lamarque, JF TI Modulation of tropospheric ozone by a propagating gravity wave SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE; ATMOSPHERE; MESOSPHERE; TURBULENCE; SPECTRUM; MIDDLE; EASOE AB The modulation of tropospheric ozone by a propagating gravity wave is inferred from the analysis of more than 200 lidar profiles obtained over a 14-hour period during September 3-4, 1993, near Rollinsville, Colorado (39.9 degrees N, 105.3 degrees W, 2.68 km msl). Periodic fluctuations of up to 30% in the ozone mixing ratios are attributed to a nearly monochromatic gravity wave with a downward phase velocity of -0.08 +/- 0.01 m s(-1), a mean vertical wavelength of 3.0 +/- 0.5 km, and an apparent frequency of(1.7 +/- 0.4) x 10(-4) s(-1). Wind profiles from nearby radar soundings suggest that these fluctuations are induced by a gravity wave that propagates from the NW to SE with a horizontal wavelength of similar to 180 km. These results imply that gravity waves may contribute significantly to the short-term (less than or equal to 1 day) variability of ozone and other trace gases in the troposphere. C1 NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, BOULDER, CO 80307 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Langford, AO (reprint author), NOAA, AERON LAB, 325 BROADWAY, R-E-AL6, BOULDER, CO 80303 USA. RI Langford, Andrew/D-2323-2009; Lamarque, Jean-Francois/L-2313-2014 OI Langford, Andrew/0000-0002-2932-7061; Lamarque, Jean-Francois/0000-0002-4225-5074 NR 40 TC 7 Z9 7 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 27 PY 1996 VL 101 IS D21 BP 26605 EP 26613 DI 10.1029/96JD02424 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VW421 UT WOS:A1996VW42100038 ER PT J AU Kasianowicz, JJ Brandin, E Branton, D Deamer, DW AF Kasianowicz, JJ Brandin, E Branton, D Deamer, DW TI Characterization of individual polynucleotide molecules using a membrane channel SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID NUCLEAR-PORE COMPLEX; SINGLE-ION CHANNEL; ALPHA-TOXIN; STAPHYLOCOCCUS-AUREUS; PROTEIN TRANSLOCATION; ESCHERICHIA-COLI; RECONSTITUTION; MITOCHONDRIA; SECA; DNA AB We show that an electric field can drive single-stranded RNA and DNA molecules through a 2.6-nm diameter ion channel in a lipid bilayer membrane. Because the channel diameter can accommodate only a single strand of RNA or DNA, each polymer traverses the membrane as an extended chain that partially blocks the channel. The passage of each molecule is detected as a transient decrease of ionic current whose duration is proportional to polymer length, Channel blockades can therefore be used to measure polynucleotide length. With further improvements, the method could in principle provide direct, high-speed detection of the sequence of bases in single molecules of DNA or RNA. C1 HARVARD UNIV,DEPT MOL & CELLULAR BIOL,CAMBRIDGE,MA 02138. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. UNIV CALIF SANTA CRUZ,DEPT CHEM & BIOCHEM,SANTA CRUZ,CA 95064. NR 28 TC 1791 Z9 1826 U1 35 U2 293 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 26 PY 1996 VL 93 IS 24 BP 13770 EP 13773 DI 10.1073/pnas.93.24.13770 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV467 UT WOS:A1996VV46700058 PM 8943010 ER PT J AU Struck, LM Richter, LJ Buntin, SA Cavanagh, RR Stephenson, JC AF Struck, LM Richter, LJ Buntin, SA Cavanagh, RR Stephenson, JC TI Femtosecond laser-induced desorption of CO from Cu(100): Comparison of theory and experiment SO PHYSICAL REVIEW LETTERS LA English DT Article ID INDUCED THERMAL-DESORPTION; DYNAMICS; SURFACE; PULSES; SPECTROSCOPY; EXCITATION; RELAXATION; CO/CU(100); VIBRATION; PT(111) AB Desorption of CO from Cu(100) by femtosecond laser pulses was investigated using state and time-resolved techniques. The results are well described by two models based on frictional coupling between the CO and the substrate degrees of freedom: an empirical, 1D model, and recent, full-dimensionality, molecular dynamics calculations. RP Struck, LM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 24 TC 88 Z9 88 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 25 PY 1996 VL 77 IS 22 BP 4576 EP 4579 DI 10.1103/PhysRevLett.77.4576 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200024 ER PT J AU Boering, KA Wofsy, SC Daube, BC Schneider, HR Loewenstein, M Podolske, JR AF Boering, KA Wofsy, SC Daube, BC Schneider, HR Loewenstein, M Podolske, JR TI Stratospheric mean ages and transport rates from observations of carbon dioxide and nitrous oxide SO SCIENCE LA English DT Article ID TROPOSPHERE; EXCHANGE; AIR; N2O; MIDLATITUDES; SPECTROMETER; CONSTITUENTS; SIMULATIONS; AEROSOL; CO2 AB Measurements of stratospheric carbon dioxide (CO2) and nitrous oxide (N2O) concentrations were analyzed to investigate stratospheric transport rates. Temporal variations in tropospheric CO2 were observed to propagate into the stratosphere, showing that tropospheric air enters the lower tropical stratosphere continuously, ascends, and is transported rapidly (in less than 1 month) to both hemispheres. The mean age A of stratospheric air determined from CO2 data is approximately 5 years in the mid-stratosphere. The mean age is mathematically equivalent to a conserved tracer analogous to exhaust from stratospheric aircraft. Comparison of values for A from models and observations indicates that current model simulations likely underestimate pollutant concentrations from proposed stratospheric aircraft by 25 to 100 percent. C1 HARVARD UNIV,DIV ENGN & APPL SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. NR 48 TC 156 Z9 157 U1 8 U2 26 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 22 PY 1996 VL 274 IS 5291 BP 1340 EP 1343 DI 10.1126/science.274.5291.1340 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU954 UT WOS:A1996VU95400042 ER PT J AU Sarmiento, JL LeQuere, C AF Sarmiento, JL LeQuere, C TI Oceanic carbon dioxide uptake in a model of century-scale global warming SO SCIENCE LA English DT Article ID ATMOSPHERIC CO2 AB In a model of ocean-atmosphere interaction that excluded biological processes, the oceanic uptake of atmospheric carbon dioxide (CO2) was substantially reduced in scenarios involving global warming relative to control scenarios. The primary reason for the reduced uptake was the weakening or collapse of the ocean thermohaline circulation. Such a large reduction in this ocean uptake would have a major impact on the future growth rate of atmospheric CO2. Model simulations that include a simple representation of biological processes show a potentially large offsetting effect resulting from the downward flux of biogenic carbon. However, the magnitude of the offset is difficult to quantify with present knowledge. RP Sarmiento, JL (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544, USA. RI Le Quere, Corinne/C-2631-2017 OI Le Quere, Corinne/0000-0003-2319-0452 NR 20 TC 214 Z9 226 U1 4 U2 30 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 22 PY 1996 VL 274 IS 5291 BP 1346 EP 1350 DI 10.1126/science.274.5291.1346 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU954 UT WOS:A1996VU95400044 ER PT J AU Hofmann, DJ AF Hofmann, DJ TI Recovery of Antarctic ozone hole SO NATURE LA English DT Letter RP Hofmann, DJ (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 8 TC 10 Z9 10 U1 1 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 21 PY 1996 VL 384 IS 6606 BP 222 EP 223 DI 10.1038/384222a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU381 UT WOS:A1996VU38100031 ER PT J AU Slaper, H Velders, GJM Daniel, JS deGruijl, FR vanderLeun, JC AF Slaper, H Velders, GJM Daniel, JS deGruijl, FR vanderLeun, JC TI Estimates of ozone depletion and skin cancer incidence to examine the Vienna Convention achievements SO NATURE LA English DT Article ID ULTRAVIOLET; UV; RADIATION; RISK; INDUCTION; SUNLIGHT; CLOUDS AB DEPLETION of the ozone layer has been observed on a global scale(1), and is probably related to halocarbon emissions, Ozone depletion increases the biologically harmful solar ultraviolet radiation reaching the surface of the Earth, which leads to a variety of adverse effects, including an increase in the incidence of skin cancer. The 1985 Vienna Convention provided the framework for international restrictions on the production of ozone-depleting substances, The consequences of such restrictions have not yet been assessed in terms of effects avoided. Here we present a new method of estimating future excess skin cancer risks which is used to compare effects of a 'no restrictions' scenario with two restrictive scenarios specified under the Vienna Convention: the Montreal Protocol, and the much stricter Copenhagen Amendments, The no-restrictions and Montreal Protocol scenarios produce a runaway increase in skin cancer incidence, up to a quadrupling and doubling, respectively, by the year 2100. The Copenhagen Amendments scenario leads to an ozone minimum around the year 2000, and a peak relative increase in incidence of skin cancer of almost 10% occurring 60 years later. These results demonstrate the importance of the international measures agreed upon under the Vienna Convention. C1 NATL INST PUBL HLTH & ENVIRONM,AIR RES LAB,NL-3720 BA BILTHOVEN,NETHERLANDS. NOAA,AERON LAB,BOULDER,CO 80303. UNIV UTRECHT,INST DERMATOL,NL-3508 GA UTRECHT,NETHERLANDS. RP Slaper, H (reprint author), NATL INST PUBL HLTH & ENVIRONM,RADIAT RES LAB,POB 1,NL-3720 BA BILTHOVEN,NETHERLANDS. RI Daniel, John/D-9324-2011 NR 28 TC 147 Z9 149 U1 4 U2 21 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 21 PY 1996 VL 384 IS 6606 BP 256 EP 258 DI 10.1038/384256a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU381 UT WOS:A1996VU38100048 PM 8918873 ER PT J AU Lock, JA Hodges, JT AF Lock, JA Hodges, JT TI Far-field scattering of a non-Gaussian off-axis axisymmetric laser beam by a spherical particle SO APPLIED OPTICS LA English DT Article ID LORENZ-MIE THEORY; LOCALIZED APPROXIMATION; RIGOROUS JUSTIFICATION; SHAPE COEFFICIENTS AB Experimental laser beam profiles often deviate somewhat from the ideal Gaussian shape of the axisymmetric TEM(00) laser mode. To take these deviations into account when calculating light scattering of an off-axis beam by a spherical particle, we use our phase-modeling method to approximate the beam-shape coefficients in the partial wave expansion of an experimental laser beam. We then use these beam-shape coefficients to compute the near-forward direction scattering of the off-axis beam by the particle. Our results are compared with laboratory data, and we give a physical interpretation of the various features observed in the angular scattering patterns. (C) 1996 Optical Society of America C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP Lock, JA (reprint author), CLEVELAND STATE UNIV,DEPT PHYS,CLEVELAND,OH 44115, USA. RI Hodges, Joseph/B-4578-2009 NR 21 TC 15 Z9 18 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1996 VL 35 IS 33 BP 6605 EP 6616 DI 10.1364/AO.35.006605 PG 12 WC Optics SC Optics GA VT736 UT WOS:A1996VT73600018 PM 21127684 ER PT J AU Trolier, M White, JWC Tans, PP Masarie, KA Gemery, PA AF Trolier, M White, JWC Tans, PP Masarie, KA Gemery, PA TI Monitoring the isotopic composition of atmospheric CO2: Measurements from the NOAA Global Air Sampling Network SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE; LATITUDINAL DISTRIBUTION; NORTHERN-HEMISPHERE; OCEANIC UPTAKE; OXYGEN; FRACTIONATION; SINKS; MODEL; C-13 AB The stable isotopic composition of atmospheric CO2 is being monitored via measurements made at the University of Colorado-Institute of Arctic and Alpine Research, using air samples collected weekly by the Global Air Sampling Network of the NOAA Climate Monitoring and Diagnostics Laboratory. These measurements, in concert with the monitoring of atmospheric CO2 mixing ratios, offer the potential to characterize quantitatively the mechanisms operating in the global carbon cycle, by recording the isotopic signatures imparted to CO2 as it moves among the atmosphere, biosphere, and oceans. This data set increases the number of measurements of atmospheric CO2 isotopes by nearly an order of magnitude over those previously available. We describe the analytical techniques used to obtain and calibrate these data and report measurements from 25 land-based sites, and two ships in the Pacific Ocean, from samples collected during 1990-1993. The typical precision of our mass spectrometric technique is 0.03 parts per thousand for delta(13)C and 0.05 parts per thousand for delta(13)O. Collecting the flask samples without drying leads to loss of delta(18)O information at many sites. The seasonal cycle in delta(13)C at sites in the northern hemisphere is highly correlated with that of the CO2 mixing ratio, with amplitudes approaching 1 parts per thousand at high latitudes. The seasonal cycle in delta(13)O is of similar amplitude, though variable from year to year and lags the other species by 2-4 months. Interhemispheric differences of the 1992 and 1993 means of the isotopic tracers are in strong contrast: the north pole-south pole difference for delta(13)C is -0.20 parts per thousand, which though highly quantitatively significant is dwarfed by the -2 parts per thousand difference for delta(18)O. In contrast to the record of atmospheric delta(13)C during the 1980s we observe no significant temporal trend in annual mean delta(13)C during 1990-1993. C1 UNIV COLORADO, HLTH SCI CTR, DEPT PEDIAT, DENVER, CO 80262 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV COLORADO, DEPT GEOL SCI, BOULDER, CO 80309 USA. RP Trolier, M (reprint author), UNIV COLORADO, INST ARCTIC & ALPINE RES, CAMPUS BOX 450, BOULDER, CO 80309 USA. RI White, James/A-7845-2009 OI White, James/0000-0001-6041-4684 NR 44 TC 136 Z9 141 U1 5 U2 32 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 NOV 20 PY 1996 VL 101 IS D20 BP 25897 EP 25916 DI 10.1029/96JD02363 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VU988 UT WOS:A1996VU98800005 ER PT J AU WongNg, W Jiang, F Cook, LP AF WongNg, W Jiang, F Cook, LP TI Phase relationships of the Pb-Sr-Ca-O system in air SO PHYSICA C LA English DT Article ID TEXTURE FORMATION; TAPES; CUO; SUPERCONDUCTORS; 800-DEGREES-C; TEMPERATURE; EQUILIBRIA; STABILITY; DIAGRAM; SILVER AB The subsolidus phase relationships of the PbO-SrO-CaO system in air were investigated at 830 degrees C to 835 degrees C, Complete solid solution exists between Ca2PbO4 and Sr2PbO4. Compatibility between SrPbO3 and the (Ca,Sr)(2)PbO4 solid solution terminates at approximately (Ca0.80Sr0.20)(2)PbO4. Tie-line relationships between (Ca,Sr)(2)PbO4 and PbO, SrPbO3, and the solid solutions (Ca,Sr)O and (Sr,Ca)O were also determined. At 830 degrees C to 835 degrees C, SrO and CaO do not form a complete solid solution, Tie-lines were found to extend from the Ca-rich solid solution (CaO to Ca0.89Sr0.11O) to nearly the entire range of (Ca,Sr)(2)PbO4. Tie-lines were also found between (Sr,Ca)(2)PbO4 (from Sr2PbO4 to Sr1.95Ca0.5PbO4) and (Sr,Ca)O (from SrO to Sr0.83Ca0.17O). No other ternary oxide phases were found in this system. C1 UNIV MARYLAND,DEPT GEOL,COLLEGE PK,MD 20742. RP WongNg, W (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 34 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 20 PY 1996 VL 272 IS 1-2 BP 87 EP 93 DI 10.1016/S0921-4534(96)00585-0 PG 7 WC Physics, Applied SC Physics GA VZ259 UT WOS:A1996VZ25900011 ER PT J AU Butler, BD Muzny, CD Hanley, HJM AF Butler, BD Muzny, CD Hanley, HJM TI Dynamic structure factor scaling in dense gelling silica suspensions SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 3rd Liquid Matter Conference CY JUL 06-10, 1996 CL UNIV E ANGLIA, NORWICH, ENGLAND SP European Phys Soc, Liquid Sect, Univ E Anglia, Inst Phys HO UNIV E ANGLIA ID AGGREGATION; SCATTERING AB Small-angle neutron scattering data from dense (30% by mass) gelling 7 nm colloidal silica spheres are presented. The coarsening process that occurs during gelation exhibits temporal self-similarity, and the time-dependent structure factor obeys the dynamic scaling relation S(q, t) similar to q(m)(-df) (t)(S) over bar(q/q(m)(t)). Here, q is the scattered wavevector, q(m)(t) is the location of the low-angle peak in S(q, t), (S) over bar(x) is a time-independent characteristic structure function which has a maximum at x = 1, and d(f) is the fractal dimension. Connections between the silica gelation and spinodal decomposition in a simple fluid are reviewed. RP Butler, BD (reprint author), NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 8 Z9 8 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 18 PY 1996 VL 8 IS 47 BP 9457 EP 9461 DI 10.1088/0953-8984/8/47/045 PG 5 WC Physics, Condensed Matter SC Physics GA VW562 UT WOS:A1996VW56200045 ER PT J AU Leibfried, D Meekhof, DM King, BE Monroe, C Itano, WM Wineland, DJ AF Leibfried, D Meekhof, DM King, BE Monroe, C Itano, WM Wineland, DJ TI Experimental determination of the motional quantum state of a trapped atom SO PHYSICAL REVIEW LETTERS LA English DT Article ID MECHANICAL STATE; TOMOGRAPHY; ION AB We reconstruct the density matrices and Wigner functions for various quantum states of motion of a harmonically bound Be-9(+) ion. We apply coherent displacements of different amplitudes and phases to the input state and measure the number state populations. Using novel reconstruction schemes we independently determine both the density matrix in the number state basis and the Wigner function. These reconstructions are sensitive indicators of decoherence in the system. RP Leibfried, D (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. RI Monroe, Christopher/G-8105-2011 NR 25 TC 492 Z9 496 U1 5 U2 17 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 NOV 18 PY 1996 VL 77 IS 21 BP 4281 EP 4285 DI 10.1103/PhysRevLett.77.4281 PG 5 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200001 ER PT J AU Enfield, DB AF Enfield, DB TI Relationships of inter-American rainfall to tropical Atlantic and Pacific SST variability SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-SURFACE TEMPERATURE; CIRCULATION; OCEAN; ANOMALIES; CLIMATE; MODEL AB Area-averaged anomalies of sea surface temperature (SSTA) and rainfall, developed from large scale data sets, have been used to explore the relative importance of Pacific versus Atlantic SST variability for inter-American (50 degrees S - 50 degrees N) climate variability at interannual time scales. SSTA in the tropical Pacific and tropical North Atlantic are comparably related to rainfall north of 15 degrees S, with clear associations distributed between the southeastern United States (US) in the north and northern South America in the south. Although NINO3 explains 25% of the variance of the North Atlantic SSTA index, the rainfall correlations with North Atlantic SSTA are for the most part opposite in sign to those with NINO3. Hence, a significant part of the Atlantic SSTA probably has a direct association with rainfall, rather than being merely an indirect proxy for Pacific ENSO linkages. In contrast to the North Atlantic, South Atlantic SSTA appear to be only related to rainfall in northeast (NE) Brazil. The entire region between Venezuela and NE Brazil appears to be sensitive to both the ITCZ and to antisymmetric configurations of SSTA across the ITCZ, in a manner consistent with the relationships between SST, surface wind and surface wind divergence fields, and with previous studies. RP Enfield, DB (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149, USA. RI Enfield, David/I-2112-2013 OI Enfield, David/0000-0001-8107-5079 NR 19 TC 131 Z9 132 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 15 PY 1996 VL 23 IS 23 BP 3305 EP 3308 DI 10.1029/96GL03231 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VU346 UT WOS:A1996VU34600006 ER PT J AU Huey, LG Lovejoy, ER AF Huey, LG Lovejoy, ER TI Reactions of SiF5- with atmospheric trace gases: Ion chemistry for chemical ionization detection of HNO3 in the troposphere SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE SiF5-; HNO3; HCO2H; chemical ionization; flowing afterglow ID NITRIC-ACID; COLORADO; SITE AB The reactions of SiF5- with a series of trace atmospheric species were studied using the flowing afterglow technique at 293 K. SiF5- reacts at the collision rate by fluoride transfer with HI and SO3. SiF5- reacts rapidly with HNO3 to primarily form a strongly bound cluster ion. SiF5- also forms more weakly bound cluster ions with HCO2H, HCl, CH3CO2H, and H2O. SiF5- was found to be unreactive with HBr, N2O5, HO2NO2, NO2, ClONO2, O-3, SO2, CH3NO3, CH3C(O)O2NO2, CO2, H2O, and NH3. These results demonstrate that SiF5- is an excellent reagent ion for the selective detection of HNO3 in ambient air with a chemical ionization mass spectrometer. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Huey, LG (reprint author), NOAA,AERON LAB,325 BROADWAY,R-E-AL7,BOULDER,CO 80303, USA. NR 24 TC 26 Z9 26 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD NOV 15 PY 1996 VL 155 IS 3 BP 133 EP 140 DI 10.1016/S0168-1176(96)04394-7 PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VW495 UT WOS:A1996VW49500002 ER PT J AU Johnson, C Greenberg, A Sander, LC AF Johnson, C Greenberg, A Sander, LC TI Separation of benzo[alpha]pyrene sulfate isomers by reversed-phase liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE optimization; benzo[alpha]pyrene sulfates; polynuclear aromatic hydrocarbons ID POLYCYCLIC AROMATIC-HYDROCARBONS; WATER-SOLUBLE METABOLITES; GLUCURONIDE; SELECTIVITY AB A liquid chromatographic (LC) method has been developed for the separation of five isomers of benzo[a]pyrene sulfate. This method utilizes a polymeric C-18 column and isocratic elution with acetonitrile-water and triethylammonium acetate. Temperature, mobile phase composition, pH, type of C-18 stationary phase and triethylamine concentration were found to influence retention and selectivity, and separations were optimized by proper choice of these parameters. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. RP Johnson, C (reprint author), UNIV N CAROLINA,DEPT CHEM,CHARLOTTE,NC 28223, USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD NOV 15 PY 1996 VL 753 IS 2 BP 201 EP 206 DI 10.1016/S0021-9673(96)00567-5 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VW917 UT WOS:A1996VW91700005 ER PT J AU McKenna, GB AF McKenna, GB TI ''Isobaric volume and enthalpy recovery of glasses .2. A transparent multiparameter theory'' - Comments SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material ID POLYMER GLASSES; TEMPERATURE; MODEL RP McKenna, GB (reprint author), NIST,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 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 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD NOV 15 PY 1996 VL 34 IS 15 BP 2463 EP 2465 DI 10.1002/polb.1996.943 PG 3 WC Polymer Science SC Polymer Science GA VM695 UT WOS:A1996VM69500003 ER PT J AU Taylor, AJ Rodriguez, G Clement, TS AF Taylor, AJ Rodriguez, G Clement, TS TI Determination of n(2) by direct measurement of the optical phase SO OPTICS LETTERS LA English DT Article ID NONLINEAR REFRACTIVE-INDEX; SINGLE-SHOT MEASUREMENT; PULSES; DISPERSION; INTENSITY; AMPLITUDE; CRYSTALS AB We determine the nonlinear refractive index, n(2), in an optical material through the direct measurement of the phase of an ultrashort optical pulse, using the technique of frequency-resolved optical gating. This method results in the accurate measurement of n(2), with the error dominated by the uncertainty in the fluence measurement. We measure n(2) in fused silica and in potassium dihydrogen phosphate at 804 and 402 nm. These results are consistent with those from previous measurements of n(2) in these materials, and the measured dispersion of n(2) in fused silica agrees with theoretical predictions. (C) 1996 Optical Society of America. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. RP Taylor, AJ (reprint author), LOS ALAMOS NATL LAB,MS D429,LOS ALAMOS,NM 87545, USA. RI Clement, Tracy/A-8885-2008; Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 12 TC 72 Z9 72 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 15 PY 1996 VL 21 IS 22 BP 1812 EP 1814 DI 10.1364/OL.21.001812 PG 3 WC Optics SC Optics GA VR424 UT WOS:A1996VR42400006 PM 19881810 ER PT J AU Schaafsma, DT Christensen, DH AF Schaafsma, DT Christensen, DH TI Mode splitting in side emission from vertical-cavity surface-emitting lasers SO PHYSICAL REVIEW B LA English DT Article ID VACUUM; ATOMS AB We present side-emission (luminescence) data from vertical-cavity surface-emitting lasers which show cavity-induced effects on the emission spectrum. In particular, the heavy-hole luminescence spectrum contains two peaks when pumped in such a way as to excite electron-hole pairs well inside the cavity region, where coupling to free-space modes is minimized, and only one peak when pumped near the edge of the cavity (near a cleaved facet), where coupling to free-space modes is maximized. This splitting;an be distinguished as a cavity-induced effect with little ambiguity from other factors present in semiconductor quantum-well radiation, such as the light- and heavy-hole splitting. A fit to the data using Lorentzian line shapes gives a vacuum-field Rabi splitting of roughly 34 meV, which is consistent with theoretical calculations and with other reports on this phenomenon. We therefore conclude that the two peaks in the spectrum are due to Rabi oscillation in the cavity, and that they represent an actual change in the energy configuration of the quantum well. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP Schaafsma, DT (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 11 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14618 EP 14622 DI 10.1103/PhysRevB.54.14618 PG 5 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700061 ER PT J AU Stiles, MD AF Stiles, MD TI Oscillatory exchange coupling in Fe/Cr multilayers SO PHYSICAL REVIEW B LA English DT Article ID LAYERED MAGNETIC-STRUCTURES; GIANT MAGNETORESISTANCE; ELECTRON TRANSMISSION; INTERLAYER EXCHANGE; CR; SUPERLATTICES; FE/CR/FE(100); INTERFACES; PERIODS; SPACER AB First-principles calculations of the reflection probabilities for Fermi-surface electrons at Cr/Fe interfaces are used to compute the strength of the oscillatory exchange coupling in Cr/Fe multilayers. These calculations show that critical spanning vectors across the N-centered ellipsoids of the Cr Fermi surface cause the long-period coupling for (001), (110), and (211) interfaces. The periods of these spanning vectors, when extracted from the experimental Fermi surface, agree with experimentally measured periods. RP Stiles, MD (reprint author), NIST,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 36 TC 63 Z9 63 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14679 EP 14685 DI 10.1103/PhysRevB.54.14679 PG 7 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700068 ER PT J AU Gutman, G Ignatov, A AF Gutman, G Ignatov, A TI The relative merit of cloud/clear identification in the NOAA/NASA Pathfinder AVHRR land 10-day composites SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID NDVI DATA SET; CLIMATE AB The Pathfinder Advanced Very High Resolution Radiometer (AVHRR) Land (PAL) dataset is a new generation of globally mapped long-term datasets produced from AVHRR onboard NOAA satellites. The PAL data, particularly their compressed version-the 10-day composites, are expected to be used quantitatively in climate applications/modelling and land cover/land cover change studies. There are, however, geographic areas that are not limited to tropics, where the 10-day composites are not cloud free. As a result, significant errors in the Normalized Difference Vegetation Index (NDVI), reflectances and brightness temperatures may occur. The PAL daily data processing included cloud/clear identification using the Clouds from AVHRR (CLAVR) procedure. The CLAVR flags were appended to each pixel but were not used for generating PAL 10-day data products. In this Letter, we use global PAL data for July 1988 to estimate quantitatively the effect of residual cloud contamination on PAL composite NDVI, reflectance, and brightness temperature data by comparing statistics of all composite pixels and of those identified by CLAVR as clear. We argue that post-composite cloud screening in PAL data is important and can be done using CLAVR flags. RP Gutman, G (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ERA12,OFF RES & APPLICAT,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. RI Ignatov, Alexander/F-5594-2010 OI Ignatov, Alexander/0000-0002-7463-5944 NR 13 TC 22 Z9 23 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 10 PY 1996 VL 17 IS 16 BP 3295 EP 3304 PG 10 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA VL981 UT WOS:A1996VL98100014 ER PT J AU Huang, Q Lynn, JW Santoro, A Chakoumakos, BC Cava, RJ Krajewski, JJ Peck, WF AF Huang, Q Lynn, JW Santoro, A Chakoumakos, BC Cava, RJ Krajewski, JJ Peck, WF TI Neutron powder diffraction study of the nuclear and magnetic structures of HoNi1.985Co0.015B2C and HoNiBC SO PHYSICA C LA English DT Article ID ANTIFERROMAGNETIC SUPERCONDUCTOR HONI2B2C AB The nuclear and magnetic structures of HoNi1.985Co0.015B2C and HoNiBC have been analyzed by neutron powder methods, The first of these materials crystallizes with the symmetry of space group I4/mmm, lattice parameters (at room temperature) a = 3.52011(9), c = 10.5286(3) Angstrom, and is isostructural with the undoped compound HoNi2B2C. Cobalt and nickel atoms are disordered over the same crystallographic sites. Well below the Neel temperature (similar to 8 K), the magnetic moments of the Ho atoms are ordered ferromagnetically in the a, b planes and antiferromagnetically along the c-axis, with a magnitude of the moment of 8.26(6)mu(B). The Co doping, even at such low concentrations, destroys the superconducting behavior of the undoped phase. The compound HoNiBC is also tetragonal (space group P4/nmm), with lattice parameters (at room temperature) a = 3.5631(2), c = 7.5486(6) Angstrom, and is isostructural with LuNiBC. Below the Neel temperature (9.82(8) K), the Ho magnetic moments are ordered ferromagnetically in the bi-layers (HoC)(HoC) with spins lying in the a, b planes, and successive bi-layers are ordered antiferromagnetically along the c-axis. The magnitude of the moments is 6.74(9)mu(B). No structural distortions associated with the magnetic ordering were observed in either compound. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. UNIV MARYLAND,COLLEGE PK,MD 20742. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. AT&T BELL LABS,MURRAY HILL,NJ 07974. RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 11 TC 17 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 10 PY 1996 VL 271 IS 3-4 BP 311 EP 318 DI 10.1016/S0921-4534(96)00532-1 PG 8 WC Physics, Applied SC Physics GA VW844 UT WOS:A1996VW84400017 ER PT J AU Jiang, HB Wang, Y Huang, YL Mulnix, AB Kadel, J Cole, K Kanost, MR AF Jiang, HB Wang, Y Huang, YL Mulnix, AB Kadel, J Cole, K Kanost, MR TI Organization of serpin gene-1 from Manduca sexta - Evolution of a family of alternate exons encoding the reactive site loop SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ACTIVATOR INHIBITOR-1 GENE; PROTEINASE-INHIBITORS; TOBACCO HORNWORM; DROSOPHILA; SUPERFAMILY; DIVERGENCE; EXPRESSION; SEQUENCES; ISOFORMS; CLONING AB Manduca sexta serpin gene-1 encodes a family of serpins whose amino acid sequences are identical in their amino terminal 336 residues but variable in their carboxyl-terminal 39-46 residues, which includes the reactive site loop (Jiang, H., Wang, Y., and Kanost, M.R. (1994) J. Biol. Chem, 269, 55-58). Here, we report the gene's complete nucleotide sequence and exon-intron structure. A unique characteristic of this gene is its exon 9, which is present in 12 alternate forms between exons 8 and 10. Isolation and characterization of cDNA clones containing exons 9C, 9H, and 9I, which were not found previously, indicate that all 12 alternate forms of exon 9 can be utilized to generate 12 different serpins. The splicing pathway apparently allows inclusion of only one exon 9 per molecule of mature serpin-1 mRNA. Analysis of exon-intron border sequences reveals unique features that may be involved in regulation of RNA splicing. The exon 9 region has apparently evolved through rounds of exon duplication and sequence divergence. The exons near the center of the region may have evolved recently, whereas the outermost exons are the most ancient. Exons 9G and 9H were duplicated as a pair from exons 9E and 9F, an event that may have occurred more than once in the history of this gene. C1 KANSAS STATE UNIV,DEPT BIOCHEM,MANHATTAN,KS 66506. EARLHAM COLL,DEPT BIOL,RICHMOND,IN 47374. NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. FU NIGMS NIH HHS [GM41247, R37 GM041247] NR 33 TC 71 Z9 73 U1 0 U2 3 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD NOV 8 PY 1996 VL 271 IS 45 BP 28017 EP 28023 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VU033 UT WOS:A1996VU03300011 PM 8910411 ER PT J AU Bell, CM Sander, LC Fetzer, JC Wise, SA AF Bell, CM Sander, LC Fetzer, JC Wise, SA TI Synthesis and characterization of extended length alkyl stationary phases for liquid chromatography with application to the separation of carotenoid isomers SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE stationary phases; LC; carotenoids; carotenes ID PENETRATION-CONTROLLED REACTIONS; ORGANIZED MONOLAYER ASSEMBLIES; MIXED TRIFUNCTIONAL SILANES; LONG-CHAIN SURFACTANTS; BETA-CAROTENE; HPLC SEPARATION; BONDED PHASES; HORIZONTAL POLYMERIZATION; PERMANGANATE INTERACTION; LUNG-CANCER AB A new, long-chain (similar to C-34) alkyl-bonded stationary phase for liquid chromatography (LC) was synthesized and utilized for the separation of carotenoid mixtures. This stationary phase exhibited increased selectivity for certain cis isomers of alpha- and beta-carotene as compared to the recently reported C-30 stationary phase. The new stationary phase was synthesized using two bonding strategies: traditional polymeric synthesis and a surface-polymerization synthesis, with the latter yielding columns with improved resolution for carotenoids. A natural extract with a high degree of cis isomerization was well separated with this long-chain stationary phase. C1 CHEVRON RES & TECHNOL CO,RICHMOND,CA 94802. RP Bell, CM (reprint author), NIST,DIV ANALYT CHEM,BLDG 222,RM B208,GAITHERSBURG,MD 20899, USA. NR 61 TC 26 Z9 26 U1 0 U2 2 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 NOV 8 PY 1996 VL 753 IS 1 BP 37 EP 45 DI 10.1016/S0021-9673(96)00562-6 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VW225 UT WOS:A1996VW22500002 ER PT J AU DrescherKrasicka, E Willis, JR AF DrescherKrasicka, E Willis, JR TI Mapping stress with ultrasound SO NATURE LA English DT Article AB Tm speed of sound in a solid is altered in the presence of mechanical stress. This effect can be exploited to form the basis of 'acoustic microscopy', whereby images of stress patterns in a material are obtained hy monitoring the times of flight of sound pulses'. The sensitivity of this approach is limited because wave speeds typically change by less than 1%, even when materials are stressed until they yield. Here we demonstrate a more sensitive form of acoustic microscopy. In an isotropic elastic medium, stress-induced anisotropies affect wave polarizations and phases, giving rise to interference between waves that would, in the absence of stress, remain in phase; the resulting patterns of interference between these waves reveal the underlying patterns of stress. This technique, by using acoustic waves of different wavelengths, permits the imaging of stress in objects ranging in size from microelectric devices to welds in pressure vessels. C1 UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 9EW,ENGLAND. NIST,GAITHERSBURG,MD 20899. NR 7 TC 9 Z9 10 U1 1 U2 7 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 7 PY 1996 VL 384 IS 6604 BP 52 EP 55 DI 10.1038/384052a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VR219 UT WOS:A1996VR21900050 ER PT J AU Gallagher, T Oliver, J Bott, R Betzel, C Gilliland, GL AF Gallagher, T Oliver, J Bott, R Betzel, C Gilliland, GL TI Subtilisin BPN' at 1.6 angstrom resolution: Analysis for discrete disorder and comparison of crystal forms SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID LEAST-SQUARES REFINEMENT; 3-DIMENSIONAL STRUCTURE; PROTEINS; 1.8-A AB The three-dimensional structure of the serine protease subtilisin BPN' (SET) has been refined at 1.6 Angstrom resolution in space group C2 to a final R value of 0.17. 17 regions of discrete disorder have been identified and analyzed. Two of these are dual-conformation peptide units; the remainder involve alternate rotamers of side chains either alone or in small clusters. The structure is compared with previously reported high-resolution models of SET in two other space groups, P2(1)2(1)2(1) and P2(1). Apart from the surface, there are no significant variations in structure among the three crystal forms. Structural variations observed at the protein surface occur predominantly in regions of protein-protein contact. The crystal packing arrangements in the three space groups are compared. C1 NATL INST STAND & TECHNOL, ROCKVILLE, MD 20850 USA. PROCTER & GAMBLE CO, CORP RES DIV, MIAMI VALLEY LABS, CINCINNATI, OH 45253 USA. GENENCOR INT INC, DEPT BIOCHEM, S SAN FRANCISCO, CA 94080 USA. DESY, INST PHYSIOL CHEM, D-22603 HAMBURG, GERMANY. RP Gallagher, T (reprint author), UNIV MARYLAND, INST BIOTECHNOL, CTR ADV RES BIOTECHNOL, 9600 GUDELSKY DR, ROCKVILLE, MD 20850 USA. NR 33 TC 18 Z9 19 U1 1 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD NOV 1 PY 1996 VL 52 BP 1125 EP 1135 DI 10.1107/S0907444996007500 PN 6 PG 11 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA VW616 UT WOS:A1996VW61600011 PM 15299573 ER PT J AU Donais, MK Uden, PC Schantz, MM Wise, SA AF Donais, MK Uden, PC Schantz, MM Wise, SA TI Development, validation, and application of a method for quantification of methylmercury in biological marine materials using das chromatography atomic emission detection SO ANALYTICAL CHEMISTRY LA English DT Article ID LEVEL ENVIRONMENTAL-SAMPLES; MICROWAVE-INDUCED PLASMA; GAS-CHROMATOGRAPHY; MERCURY-COMPOUNDS; ABSORPTION SPECTROMETRY; LIQUID-CHROMATOGRAPHY; SPECIATION; DISTILLATION AB A gas chromatographic method was developed for the quantification of alkylmercury species using microwave-induced plasma atomic emission detection (GC-AED), The column conditioning and analyte derivatization required for previous methods were found to be unnecessary for stable, accurate, and sensitive element-specific detection using GC-AED, Chromatographic and detection parameters such as stationary phase type, stationary phase film thickness, GC column dimensions, helium mobile phase column head pressure, detector makeup gas now rate, and detector reagent gas type and now rate were found to significantly affect analyte response, The detection limit for the optimized GC-AED conditions was 0.8 pg (0.1 pg/s) of methylmercury chloride (as mercury), A solid-liquid extraction procedure with preparative gel permeation chromatography cleanup and GC-AED analysis was used to quantify methylmercury in a variety of complex matrix marine materials, The methylmercury quantification method was validated: with four marine certified reference materials (CRMs). The method was then applied to 13 standard reference materials, CRMs, and control materials for which no certified reference values for methylmercury have been determined, Four National Institute of Standards and Technology Standard Reference Materials and one control material, which were analyzed using the GC-AED method, were also analyzed by two other laboratories using independent methods to further validate the method. C1 UNIV MASSACHUSETTS,DEPT CHEM,AMHERST,MA 01003. RP Donais, MK (reprint author), NIST,DIV ANALYT CHEM,CHEM ROOM B208,GAITHERSBURG,MD 20899, USA. NR 44 TC 37 Z9 38 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1996 VL 68 IS 21 BP 3859 EP 3866 DI 10.1021/ac960438a PG 8 WC Chemistry, Analytical SC Chemistry GA VQ157 UT WOS:A1996VQ15700033 PM 21619261 ER PT J AU Idenden, DW Moffett, RJ Quegan, S FullerRowell, TJ AF Idenden, DW Moffett, RJ Quegan, S FullerRowell, TJ TI Time-dependent convection at high latitudes SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; IONOSPHERIC CONVECTION; PLASMA CONVECTION; ION CONVECTION; MODEL; EXCITATION; SUBSTORMS; DEFLATION; BOUNDARY; PATTERN AB A fully time-dependent ionospheric convection model, in which electric potentials are derived by an analytic solution of Laplace's equation, is described. This model has been developed to replace the empirically derived average convection patterns currently used routinely in the Sheffield/SEL/UCL coupled thermosphere/ionosphere/plasmasphere model (CTIP) for modelling disturbed periods. Illustrative studies of such periods indicate that, for the electric field pulsation periods imposed, longterm averages of parameters such as Joule heating and plasma density have significantly different values in a time-dependent model compared to those derived under the same mean conditions in a steady-state model. These differences are indicative of the highly non-linear nature of the processes involved. C1 UNIV COLORADO,CIRES,NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80301. RP Idenden, DW (reprint author), UNIV SHEFFIELD,SCH MATH & STAT,HICKS BLDG,SHEFFIELD S3 7RH,S YORKSHIRE,ENGLAND. NR 29 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD NOV PY 1996 VL 14 IS 11 BP 1159 EP 1169 DI 10.1007/s005850050378 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA VT490 UT WOS:A1996VT49000007 ER PT J AU Gall, K Desrosiers, M Bensen, D Serago, C AF Gall, K Desrosiers, M Bensen, D Serago, C TI Alanine EPR dosimeter response in proton therapy beams SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT 4th International Symposium on ESR Dosimetry and Applications CY MAY 15-19, 1995 CL MUNICH, GERMANY SP GSF, IAEA, WHO, Russian Acad Sci ID RADIATION AB We report a series of measurements directed to assess the suitability of alanine as a mailable dosimeter for dosimetry quality assurance of proton radiation therapy beams. These measurements include dose-response of alanine at 140 MeV, and comparison of response vs energy with a parallel plate ionization chamber. All irradiations were made at the Harvard Cyclotron Laboratory, and the dosimeters were read at NIST. The results encourage us that alanine could be expected to serve as a mailable dosimeter with Systematic error due to differential energy response no greater than 3% when doses of 25 Gy are used. Copyright (C) 1996 Published by Elsevier Science Ltd C1 NIST,IONIZING RADIAT DIV,US DEPT COMMERCE,GAITHERSBURG,MD 20899. MASSACHUSETTS GEN HOSP,DEPT RADIAT ONCOL,BOSTON,MA 02114. FU NCI NIH HHS [CA 21239] NR 3 TC 11 Z9 11 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD NOV-DEC PY 1996 VL 47 IS 11-12 BP 1197 EP 1199 DI 10.1016/S0969-8043(96)00201-1 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 WD715 UT WOS:A1996WD71500012 PM 9022180 ER PT J AU Schauer, DA Desrosiers, MF Kuppusamy, P Zweier, JL AF Schauer, DA Desrosiers, MF Kuppusamy, P Zweier, JL TI Radiation dosimetry of an accidental overexposure using EPR spectrometry and imaging of human bone SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT 4th International Symposium on ESR Dosimetry and Applications CY MAY 15-19, 1995 CL MUNICH, GERMANY SP GSF, IAEA, WHO, Russian Acad Sci ID EXPOSURE AB On 11 December 1991 a radiation accident occurred at an industrial accelerator facility. A description of the facility and details of the accident are reported in Schauer et al., 1993a). In brief, during maintenance on the lower window pressure plate of a 3 MV potential drop accelerator, an operator placed his hands, head, and feet in the radiation beam. The filament voltage of the electron source was turned 'off, but the full accelerating potential was on the high voltage terminal. The operator's body, especially his extremities and head, were exposed to electron dark current. At approx. 3 months post-irradiation, the four digits of the victim's right hand and most of the four digits of his left hand were amputated. Electron paramagnetic resonance (EPR spectrometry was used to estimate the radiation dose to the victim's extremities. Extremity dose estimates ranged from 55.0 Gy (+/-4.7 Gy) to 108 Gy (+/-24.1 Gy). Copyright (C) 1996 Published by Elsevier Science Ltd C1 JOHNS HOPKINS MED INST,SCH HYG & PUBL HLTH,DIV RADIAT HLTH SCI,BALTIMORE,MD 21205. NIST,TECHNOL ADM,DEPT COMMERCE,PHYS LAB,IONIZING RADIAT DIV,RADIAT INTERACT & DO,GAITHERSBURG,MD 20899. JOHNS HOPKINS UNIV,SCH MED,MOL & CELLULAR BIOPHYS LABS,BALTIMORE,MD 21224. JOHNS HOPKINS UNIV,SCH MED,EPR CTR,DEPT MED,BALTIMORE,MD 21224. NR 8 TC 34 Z9 34 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD NOV-DEC PY 1996 VL 47 IS 11-12 BP 1345 EP 1350 DI 10.1016/S0969-8043(96)00203-5 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 WD715 UT WOS:A1996WD71500037 PM 9022195 ER PT J AU Fattibene, P Duckworth, TL Desrosiers, MF AF Fattibene, P Duckworth, TL Desrosiers, MF TI Critical evaluation of the sugar-EPR dosimetry system SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT 4th International Symposium on ESR Dosimetry and Applications CY MAY 15-19, 1995 CL MUNICH, GERMANY SP GSF, IAEA, WHO, Russian Acad Sci ID ELECTRON-SPIN-RESONANCE; ESR DOSIMETRY AB Sugar has received much attention as an emergency dosimeter for the general populace. This study was undertaken to clarify several conflicts in the literature. Here we report on the spectral characteristics of common 'cane' sugar and sucrose, the lower limit of detection for cane sugar, and the influence of absorbed dose on the study of time-dependent EPR signal intensity changes. Copyright (C) 1996 Elsevier Science Ltd C1 IST NAZL FIS NUCL,SEZ SANITA,I-00161 ROME,ITALY. NIST,IONIZING RADIAT DIV,TECHNOL ADM,DEPT COMMERCE,GAITHERSBURG,MD 20899. RP Fattibene, P (reprint author), IST SUPER SANITA,VIALE REGINA ELENA 299,I-00161 ROME,ITALY. RI fattibene, paola/E-9041-2015 OI fattibene, paola/0000-0002-8204-0414 NR 10 TC 39 Z9 39 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD NOV-DEC PY 1996 VL 47 IS 11-12 BP 1375 EP 1379 DI 10.1016/S0969-8043(96)00254-0 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 WD715 UT WOS:A1996WD71500043 ER PT J AU Desrosiers, MF AF Desrosiers, MF TI Current status of the EPR method to detect irradiated food SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT 4th International Symposium on ESR Dosimetry and Applications CY MAY 15-19, 1995 CL MUNICH, GERMANY SP GSF, IAEA, WHO, Russian Acad Sci ID ELECTRON-SPIN-RESONANCE; LOBSTER NEPHROPS-NORVEGICUS; RADIATION-PROCESSED FOOD; FREE-RADICALS; ESR SIGNAL; CHICKEN DRUMSTICKS; PARAMAGNETIC RESONANCE; RESPONSE FUNCTION; GAMMA-RADIATION; IDENTIFICATION AB This review gives a brief outline of the principles of the EPR detection method for irradiated foods by food type. For each food type, the scope, limitations and status of the method are given. The extensive reference list aims to include all which define the method, as well as some rarely cited works of historical importance. Copyright (C) 1996 Elsevier Science Ltd RP Desrosiers, MF (reprint author), NATL INST STAND & TECHNOL,PHYS LAB,TECHNOL ADM,DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. NR 80 TC 62 Z9 65 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD NOV-DEC PY 1996 VL 47 IS 11-12 BP 1621 EP 1628 DI 10.1016/S0969-8043(96)00255-2 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 WD715 UT WOS:A1996WD71500086 PM 9022201 ER PT J AU Laracuente, A Bronikowski, MJ Gallagher, A AF Laracuente, A Bronikowski, MJ Gallagher, A TI Chemical vapor deposition of nanometer-size aluminum features on silicon surfaces using an STM tip SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Symposium on Atomically Controlled Surfaces and Interfaces CY OCT 12-14, 1995 CL RALEIGH, NC ID SCANNING-TUNNELING-MICROSCOPE AB We have deposited aluminum (Al) features on silicon (Si) surfaces using the electron beam and electric field produced at the tip of a scanning tunneling microscope (STM), in both tunneling and field emission modes. Lines as small as 3 nm in width have been produced on crystal Si(001). Al deposition is accomplished by exposing the tip-sample junction to trimethylaluminum (TMA) gas while tunneling. The electron beam of the STM tip dissociates the TMA molecules adsorbed on the surface, resulting in the production of surface-bound Al and hydrocarbon gas. Independent Auger electron spectroscopy studies of the electron induced deposition of Al from TMA shows nearly pure Al deposits. C1 UNIV COLORADO,BOULDER,CO 80309. RP Laracuente, A (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 6 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD NOV PY 1996 VL 107 BP 11 EP 17 DI 10.1016/S0169-4332(96)00514-4 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VV197 UT WOS:A1996VV19700004 ER PT J AU French, BL Reichert, WL Hom, T Nishimoto, M Sanborn, HR Stein, JE AF French, BL Reichert, WL Hom, T Nishimoto, M Sanborn, HR Stein, JE TI Accumulation and dose-response of hepatic DNA adducts in English sole (Pleuronectes vetulus) exposed to a gradient of contaminated sediments SO AQUATIC TOXICOLOGY LA English DT Article DE DNA adducts; bile fluorescence; PAHs; sediment exposure; biomarkers; accumulation ID C-14 POLYCHLORINATED-BIPHENYLS; PAROPHRYS-VETULUS; AROMATIC-COMPOUNDS; PUGET SOUND; P-32-POSTLABELING ANALYSIS; H-3 BENZOPYRENE; REPAIR SYNTHESIS; POLLUTED HARBOR; PERSISTENCE; LIVER AB Levels of hepatic DNA adducts and concentrations of fluorescent aromatic compounds (FACs) in bile were measured in English sole (Pleuronectes vetulus) exposed for up to 5 weeks to a reference sediment amended with a sediment containing high concentrations of polycyclic aromatic compounds (PACs) from Eagle Harbor, Puget Sound, WA. Levels of hepatic DNA adducts increased linearly with both concentration of sediment polycyclic aromatic hydrocarbons (PAHs) and length of exposure, whereas concentrations of biliary FACs were dose-responsive to levels of sediment PAHs but attained steady-state concentrations after 2 weeks of exposure. The levels of DNA adducts and concentrations of biliary FACs in fish exposed to the reference sediment remained at baseline levels throughout the exposure. Formation of PAC-DNA adducts was observed in liver of English sole injected with an extract of Eagle Harbor sediment (EHSE) and in English sole hepatocytes incubated with EHSE or the neutral fraction of EHSE containing predominantly PACs. In addition, DNA adduct and biliary FAC levels measured in feral English sole captured from Eagle Harbor, when compared with levels measured in fish from the laboratory sediment exposure study, also suggested accumulation of DNA adducts in the fish captured from Eagle Harbor. These findings, in conjunction with previous studies showing PAC-DNA adducts are persistent in fish, suggest that a substantial proportion of PAC-induced DNA damage was not readily repaired in English sole, and thus, measurement of hepatic DNA adducts can be used as an indicator of cumulative exposure to genotoxic PACs. RP French, BL (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,ENVIRONM CONSERVAT DIV,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 38 TC 62 Z9 68 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD NOV PY 1996 VL 36 IS 1-2 BP 1 EP 16 DI 10.1016/S0166-445X(96)00812-0 PG 16 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA VY982 UT WOS:A1996VY98200001 ER PT J AU Husoy, AM Myers, MS Goksoyr, A AF Husoy, AM Myers, MS Goksoyr, A TI Cellular localization of cytochrome P450 (CYP1A) induction and histology in Atlantic cod (Gadus morhua L) and European flounder (Platichthys flesus) after environmental exposure to contaminants by caging in Sorfjorden, Norway SO AQUATIC TOXICOLOGY LA English DT Article DE caging; CYP1A; immunohistochemistry; liver histopathology; pollution; Atlantic cod; flounder ID XENOBIOTIC-METABOLIZING ENZYMES; TROUT ONCORHYNCHUS-MYKISS; SOLE PLEURONECTES-VETULUS; DAB LIMANDA-LIMANDA; IMMUNOHISTOCHEMICAL LOCALIZATION; HEPATIC NEOPLASMS; CHEMICAL CONTAMINANTS; EXTRAHEPATIC TISSUES; POLLUTION TRANSECT; TOXIC-CHEMICALS AB Immunohistochemical and histopathological studies were conducted in two marine teleosts, Atlantic cod (Gadus morhua) and European flounder (Platichthys flesus), caged for three months on contaminated sediments in a Norwegian fjord, Cellular localization of CYP1A was analyzed immunohistochemically in liver, intestine, heart, gill and kidney, as part of an extensive study that included a number of chemical and biological measurements. Both species exhibited marked CYP1A induction when caged at contaminated sites. CYP1A induction was observed in liver as well as in several extrahepatic organs, and with increased expression at the more contaminated sites, Staining was particularly strong in vascular en endothelium. Induction responses were also observed in epithelial cells, including hepatocytes, biliary epithelial cells, mucosal epithelial cells in the intestine, and renal tubular epithelial cells, Histopathological examination of the liver did not reveal major cellular abnormalities, The immunohistochemical data indicate a strong relationship between CYP1A induction and exposure to sediment-associated industrial contaminants (polycyclic aromatic hydrocarbons). Interesting species differences in localization of CYP1A expression in Various cell types in cod and flounder were demonstrated immunohistochemically. C1 UNIV BERGEN,LAB MARINE MOL BIOL,HIB,N-5020 BERGEN,NORWAY. NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,ENVIRONM CONSERVAT DIV,SEATTLE,WA 98112. RI Goksoyr, Anders/F-8320-2010; Goksoyr, Anders/A-2818-2013 OI Goksoyr, Anders/0000-0003-4054-9842; Goksoyr, Anders/0000-0003-4054-9842 NR 56 TC 38 Z9 41 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD NOV PY 1996 VL 36 IS 1-2 BP 53 EP 74 DI 10.1016/S0166-445X(96)00797-7 PG 22 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA VY982 UT WOS:A1996VY98200004 ER PT J AU Rao, CN Reddy, P Liu, YY OToole, E Reeder, D Foster, DC Kisiel, W Woodley, DT AF Rao, CN Reddy, P Liu, YY OToole, E Reeder, D Foster, DC Kisiel, W Woodley, DT TI Extracellular matrix-associated serine protease inhibitors (M(r) 33,000, 31,000, and 27,000) are single-gene products with differential glycosylation: cDNA cloning of the 33-kDa inhibitor reveals its identity to tissue factor pathway inhibitor-2 SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article DE extracellular matrix; serine protease inhibitors; fibroblasts; glycosylation; tissue factor pathway inhibitor-2 ID FIBROBLAST GROWTH-FACTOR; PLASMINOGEN-ACTIVATOR INHIBITOR; ENDOTHELIAL-CELLS; UROKINASE RECEPTOR; PROTEINASE-INHIBITORS; HEPARAN-SULFATE; LYS-PLASMINOGEN; SARCOMA-CELLS; CANCER-CELLS; EXPRESSION AB Recently, we reported the identification and partial characterization of three serine protease inhibitors (M(r) 33,000, 31,000, and 27,000) from the extracellular matrix (ECM) of human umbilical vein endothelial cells and skin cells. Here, we report that a full-length cDNA clone for the 33-kDa inhibitor from SV-40 transformed human skin fibroblasts (tl2FB) is identical to a recombinant trypsin/tissue factor pathway inhibitor called TFPI-2 from placenta. By immunoblotting, the three inhibitors from ECM and cell lysates demonstrated cross-reactivity with an antiTFPI-2 IgG. To further elucidate how these inhibitors are related, pulse-chase labeling of T12FB with [S-35]methionine followed by immunoprecipitation with antiTFPI-2 IgG was performed on ECM and cytosolic proteins. A precursor-product relationship did not exist between the three inhibitors from ECM. In contrast, the various species of inhibitors from cytosolic fractions demonstrated a precursor-product relationship. Within the cytosolic fraction, 26-, 29-, and 30-kDa inhibitors were detected in the early chases (0 and 15 min) but they form precursors to the synthesis of the 33-kDa inhibitor which accumulated in the later chases (30 min to 1 h). When pulse-chase experiments were performed in the presence of tunicamycin, synthesis as well as sequestration of the three inhibitors into ECM was completely inhibited. In the presence of tunicamycin, the cells synthesized and sequestered a single 25.5-kDa inhibitor into ECM. Peak quantities of the 25.5-kDa inhibitor appeared in the ECM after 6 h chase while they were 1 h for the 27- and 31-kDa inhibitors and 3 h for the 33-kDa inhibitor. To further support that the three inhibitors are related but only differ in the extent of glycosylation, the 33-kDa inhibitor from the t12FB ECM was deglycosylated with N-glycosidase F and the products were identified by immunoblotting with anti-TFPI-2 IgG. The enzyme released the 31-, 27-, and 25.5-kDa inhibitors from the 33-kDa inhibitor. Collectively, these results demonstrate that the ECM-associated 33-, 31-, and 27-kDa inhibitors are biosynthetic products of a single gene with differential glycosylation. The 25.5-kDa inhibitor is unglycosylated, whereas 27- and 30-to 31-kDa inhibitors are partially glycosylated and the 33-kDa inhibitor is fully glycosylated. Inhibition of glycosylation significantly retarded the rate of secretion of the inhibitor but did not prevent its association with ECM. Quantitation of the inhibitors with cell-conditioned medium and ECM fractions reveals that 70-75% were ECM-associated and 25-30% cell-associated. None or very little of the inhibitors (0-2%) remained in a conditioned medium. Because they are primarily associated with ECM, the inhibitors may play a major role in ECM remodeling and turnover. (C) 1996 Academic Press, Inc. C1 NATL INST STAND & TECHNOL, DIV BIOTECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20897 USA. UNIV NEW MEXICO, SCH MED, DEPT PATHOL, ALBUQUERQUE, NM 87131 USA. ZYMOGENET INC, SEATTLE, WA 98102 USA. RP NORTHWESTERN UNIV, SCH MED, DEPT DERMATOL, TARRY BLDG 4711, 303 E CHICAGO AVE, CHICAGO, IL 60611 USA. FU NHLBI NIH HHS [HL 35246]; NIAMS NIH HHS [AR 33625, AR 41045] NR 52 TC 78 Z9 84 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0003-9861 EI 1096-0384 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD NOV 1 PY 1996 VL 335 IS 1 BP 82 EP 92 DI 10.1006/abbi.1996.0484 PG 11 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VT732 UT WOS:A1996VT73200010 PM 8914837 ER PT J AU Bushby, ST AF Bushby, ST TI Testing the conformance and interoperability of BACnet(TM) systems SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article RP Bushby, ST (reprint author), NATL INST STAND & TECHNOL,MECH SYST & CONTROLS GRP,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD NOV PY 1996 VL 38 IS 11 BP 45 EP & PG 4 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA VV796 UT WOS:A1996VV79600014 ER PT J AU Morse, JA Blair, WP Dopita, MA Hughes, JP Kirshner, RP Long, KS Raymond, JC Sutherland, RS Winkler, PF AF Morse, JA Blair, WP Dopita, MA Hughes, JP Kirshner, RP Long, KS Raymond, JC Sutherland, RS Winkler, PF TI Hubble Space Telescope observations of oxygen-rich supernova remnants in the magellanic clouds .1. Narrowband imaging of N132D in the lmc (vol 112, pg 509, 1996) SO ASTRONOMICAL JOURNAL LA English DT Correction, Addition C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,CANBERRA,ACT 2611,AUSTRALIA. HARVARD UNIV,HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV COLORADO,JILA,BOULDER,CO 80309. NIST,BOULDER,CO 80309. MIDDLEBURY COLL,DEPT PHYS,MIDDLEBURY,VT 05753. RP Morse, JA (reprint author), SPACE TELESCOPE SCI INST,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 1996 VL 112 IS 5 BP 2350 EP 2351 DI 10.1086/118189 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ496 UT WOS:A1996VQ49600051 ER PT J AU Bennett, PD Harper, GM Brown, A Hummel, CA AF Bennett, PD Harper, GM Brown, A Hummel, CA TI The masses and radii of the eclipsing binary zeta Aurigae SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, binaries, eclipsing; stars, fundamental parameters; stars, individual (zeta Aurigae); techniques, interferometric; techniques, radial velocities; ultraviolet, stars ID OPTICAL INTERFEROMETRY; RADIATIVE OPACITIES; STELLAR MODELS; ORBIT; ABUNDANCES; PARAMETERS; EXTINCTION; SPECTRA; SOLAR; STARS AB We present a full determination of the fundamental stellar and orbital parameters of the eclipsing binary zeta Aurigae (K4 Ib + B5 V) using recent observations with the Hubble Space Telescope Goddard High Resolution Spectrograph (GHRS) and the Mark III long-baseline optical interferometer. The information obtained from spectroscopic and interferometric measurements is complementary, and the combination permits a complete determination of the stellar masses, the absolute semimajor axis of the orbit, and the distance. A complete solution requires that both components be visible spectroscopically, and this has always been difficult for the zeta Am systems. The zeta Aur K star primary presents no difficulty, and accurate radial velocities are readily obtainable in the optical. However, the B star secondary is more problematic. Ground-based radial velocity measurements are hampered by the difficulty of working with the composite spectrum in the blue-violet region, the small number of suitable lines in the generally featureless optical spectrum of the B star, and the great width of the few available lines (the Balmer lines of hydrogen and a few weak He I lines) due to rapid rotation. We avoid the worst of these problems by using GHRS observations in the ultraviolet, where the K star flux is negligible and the intrinsic B star spectrum is more distinctive, and obtain the most accurate determination of the B star radial velocity amplitude to date. We also analyze published photometry of previous eclipses and near-eclipse phases of zeta Aur in order to obtain eclipse durations, which fix the length of the eclipse chord and therefore determine the orbit inclination. The long-baseline interferometry (LBI) yields, in conjunction with the spectroscopic solution, the distance to the system and thus the absolute stellar radius of the resolved K supergiant primary star, zeta Am A. The secondary is not resolved by LBI, but its angular (and absolute) radius is found by fitting the model stellar flux plus an interstellar extinction model to the flux-calibrated GHRS data. We find M(K) = 5.8 +/- 0.2 M(Theta), M(B) = 4.8 +/- 0.2 M(Theta), R(K) = 148 +/- 3 R(Theta), and R(B), = 4.5 +/- 0.3 R(Theta) for the masses and radii of the zeta Am stars. We determine the distance to zeta Am to be 261 +/- 3 pc. Additionally, we refine the stellar parameters of the B star secondary presented in the 1995 spectroscopic study of Bennett, Brown, & Linsky. We also determine the effective temperature of the K star primary using values of the bolometric flux, angular diameter, and interstellar extinction derived in this study. The positions of the zeta Am stars on the theoretical H-R diagram are compared to current evolutionary model tracks, and the resulting good agreement provides a strong check of the internal selfconsistency of this analysis and the accuracy of the theoretical models. The zeta Aurigae stars are confirmed to be coeval with an age of 80 +/- 15 Myr. C1 UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. UNIV COLORADO, CTR ASTROPHYS & SPACE ASTRON, BOULDER, CO 80309 USA. UNIV SPACE RES ASSOC, WASHINGTON, DC 20004 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. NR 50 TC 24 Z9 24 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 NOV 1 PY 1996 VL 471 IS 1 BP 454 EP 479 DI 10.1086/177981 PN 1 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VP223 UT WOS:A1996VP22300034 ER PT J AU Davidson, MJ Snyder, WH Lawson, RE Hunt, JCR AF Davidson, MJ Snyder, WH Lawson, RE Hunt, JCR TI Wind tunnel simulations of plume dispersion through groups of obstacles SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE wind tunnel; obstacle array; flow field; plume dispersion ID DIFFUSION; SURFACE; FLOWS AB In this paper we present the results of two wind-tunnel simulations of dispersion from upwind point sources through a large group of obstacles, and compare these with an associated field study (Davidson et al., 1995, Atmospheric Environment 29, 3245-3256), Detailed flow-field and plume concentration data were obtained from simulations at scales of 1:20 and 1:200. With these data we are able to provide experimental confirmation of many of the ideas developed during the field study and to confirm the experimental results obtained in the field. In doing so, we show that the upstream flow-field parameters are the most effective means of scaling the three data sets to achieve broad quantitative agreement. Measurements and flow visualisation of the flow-field confirm that there are a number of mechanisms influencing the behaviour of a plume as it passes through an obstacle array: in particular the divergence and convergence of streamlines and changes to the structure of the turbulence within the array, However, although the turbulence within the array is shown to be of greater strength and smaller scale than at corresponding locations outside the obstacle array, it is found that there is little change in the transverse diffusivity (and therefore in the lateral plume width). The concentration data confirm that the divergence of streamlines near the upstream end of the obstacle array has a significant effect on the vertical width of a plume (sigma(2)). Changes to the structure of the turbulence appear to have little effect, however, since the transverse diffusivities within the obstacle array are unchanged. Thus, the mean lateral spread and decay of mean concentration of the plume with downstream distance resemble that of a control plume; that is; a plume released under identical conditions where the obstacle array is not present. We also confirm that the mean structure of a plume has a Gaussian form as it passes through an array of obstacles. By contrast, concentration measurements with a high-frequency-response detector confirm that the small-scale, high-strength turbulence rapidly mixes the plume internally, dramatically reducing the strength of concentration fluctuations within the plume. Since the wind tunnel is shown to be an effective means of modelling this type of field situation, with the appropriate scaling, these studies were extended to consider the effects on plume behaviour of changes in source position, array configuration and array height. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV CAMBRIDGE, DEPT APPL MATH & THEORET PHYS, CAMBRIDGE CB3 9EW, ENGLAND. NOAA, ATMOSPHER SCI MODELING DIV, AIR RESOURCES LAB, RES TRIANGLE PK, NC 27711 USA. NR 26 TC 59 Z9 63 U1 1 U2 8 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 NOV PY 1996 VL 30 IS 22 BP 3715 EP 3731 DI 10.1016/1352-2310(96)00103-3 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VE429 UT WOS:A1996VE42900004 ER PT J AU Stohl, A Williams, E Wotawa, G KrompKolb, H AF Stohl, A Williams, E Wotawa, G KrompKolb, H TI A European inventory of soil nitric oxide emissions and the effect of these emissions on the photochemical formation of ozone SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE nitric oxide; nitrogen oxides; soil NO emissions; emission inventory; ozone formation; photochemistry ID NITROGEN-OXIDES; UNITED-STATES; FIELD-MEASUREMENTS; TROPICAL SAVANNA; EDDY-CORRELATION; NOX EMISSIONS; FLUXES; DEPOSITION; N2O; GRASSLAND AB An inventory of soil nitric oxide (NO) emissions for Europe was developed. The emission of NO was parameterized using empirical relationships with type of landuse, fertilization rate of agricultural areas and soil temperature. For the year 1994, it was estimated that annual soil NO emissions in the inventoried area amounted to 535 kt NO-N yr(-1), i.e. 8% of the emissions from combustion processes. On a hot summer day, this fraction increased to 27%. The uncertainty of these emission estimates, however, is high. They are accurate only within a factor of three to four. As the major fraction (in summer 81%) of the emissions came from arable land, soil NO emissions have to be considered as largely anthropogenic. Large regional differences existed in the soil NO emission rates with the highest emission rates found in southern and western Europe, intermediate rates in eastern Europe and the lowest rates in Scandinavia and northern Russia. The effect of the soil NO emissions on the photochemical formation of ozone (O-3) was investigated with a one-dimensional photochemical model. When soil NO emissions were considered in the model simulations, computed mean daily maximum O-3 concentrations over Europe from June to August 1994 were 4 ppb (uncertainty range: 1.4-9.6 ppb) higher than without these emissions. Reductions of pyrogenic NOx emissions were less efficient in reducing O-3 concentrations when soil NO emissions were taken into account. Copyright (C) 1996 Elsevier Science Ltd. C1 NOAA,AERON LAB,BOULDER,CO 80303. RP Stohl, A (reprint author), UNIV AGR FORESTRY & RENEWABLE NAT RESOURCES,INST METEOROL & PHYS,TURKENSCHANZSTR 18,A-1185 VIENNA,AUSTRIA. RI Stohl, Andreas/A-7535-2008; Williams, Eric/F-1184-2010 OI Stohl, Andreas/0000-0002-2524-5755; NR 52 TC 68 Z9 77 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD NOV PY 1996 VL 30 IS 22 BP 3741 EP 3755 DI 10.1016/1352-2310(96)00104-5 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VE429 UT WOS:A1996VE42900006 ER EF