FN Thomson Reuters Web of Science™ VR 1.0 PT J AU SCHUMACHER, JD KENDALL, AW AF SCHUMACHER, JD KENDALL, AW TI SOME INTERACTIONS BETWEEN YOUNG WALLEYE POLLOCK AND THEIR ENVIRONMENT IN THE WESTERN GULF OF ALASKA SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article AB Surveys in Shelik of Strait, Alaska, show that large concentrations of walleye pollock (Theragra chalcogramma) enter the sea valley each March and spawn early in April. Surveys for eggs and larvae have disclosed dense regions of eggs that become patches of larvae. Processes that transport larvae to nursery grounds or to the open ocean seem important to recruitment. Early results suggested that larvae could be rapidly removed (in 14 days) from the shelf by the vigorous, varying flow of the Alaska Coastal Current (ACC). In the upper 100 m, however, most of the volume transport remains on the shelf Baro-clinic instability between the ACC and coastal waters can create eddies (first observed in infrared satellite images) at the exit of Shelik of Strait. Eddies frequently contain the highest concentrations of larvae. The phasing and location of eddies, the ACC, and hatching determine how a given mechanism will affect retention of larvae on the shelf. Year-class size seems largely determined by the end of the larval period, although events during the following summer may also reduce the year class. Storms during the early larval period may be particularly detrimental to survival, although the mechanism is not yet clear. An index of storminess in the Gulf of Alaska may provide a way of predicting year-class size. Studies of physical and biological conditions in larval patches and adjacent shelf waters are being made to determine whether growth and mortality rates differ in these areas. RP SCHUMACHER, JD (reprint author), PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 0 TC 29 Z9 31 U1 0 U2 2 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD NOV PY 1991 VL 32 BP 22 EP 40 PG 19 WC Fisheries SC Fisheries GA GZ763 UT WOS:A1991GZ76300003 ER PT J AU LENARZ, WH LARSON, RJ RALSTON, S AF LENARZ, WH LARSON, RJ RALSTON, S TI DEPTH DISTRIBUTIONS OF LATE LARVAE AND PELAGIC JUVENILES OF SOME FISHES OF THE CALIFORNIA CURRENT SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article AB The vertical distribution of pelagic young-of-the-year larval and juvenile fishes in the California Current is reviewed. New data from synoptic midwater trawls conducted at depths of 13, 37, and 117 m along the central California coast are presented. Data for 15 species of rockfish, Dover and rex soles, northern anchovy, and Pacific whiting show that most species tend toward a uniform distribution among the three sampled depths. Notable exceptions include bocaccio (most abundant at 13 m) and blue, yellowtail, and pygmy rockfishes (most abundant at 117 m). With the advent of persistent upwelling during May and June, pelagic juvenile rockfish tend to occur deeper in the water column than in March-April. Data about shortbelly rockfish support the view that during periods of intense upwelling (May-June) relatively small fish stay deep, presumably to avoid advection offshore. There was not a clear relationship between depth distribution of fish and depth of the thermocline. RP LENARZ, WH (reprint author), NATL MARINE FISHERIES SERV,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 0 TC 29 Z9 29 U1 1 U2 2 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD NOV PY 1991 VL 32 BP 41 EP 46 PG 6 WC Fisheries SC Fisheries GA GZ763 UT WOS:A1991GZ76300004 ER PT J AU SCHWING, FB HUSBY, DM GARFIELD, N TRACY, DE AF SCHWING, FB HUSBY, DM GARFIELD, N TRACY, DE TI MESOSCALE OCEANIC RESPONSE TO WIND EVENTS OFF CENTRAL CALIFORNIA IN SPRING 1989 - CTD SURVEYS AND AVHRR IMAGERY SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article AB Analysis of hydrographic data obtained during juvenile groundfish surveys, in relation to local wind forcing and AVHRR sea-surface temperature imagery, reveals that the oceanic region off central California between Point Reyes and Point Sur in spring 1989 was characterized by complex circulation patterns and considerable temporal and mesoscale variability. The "spring transition" to upwelling-favorable winds is most clearly evidenced by rapid, large decreases in SST (up to 4-degrees-5-degrees-C) measured at four meteorological buoys. Daily-averaged winds are spatially coherent and oscillate between upwelling-favorable and relaxation conditions at 3-10-day intervals. Persistent upwelling centers near Point Reyes and Point Ano Nuevo were characterized by relatively cool, salty (8-degrees-10-degrees-C, 33.6-34.0 psu) water in the tipper 50 m, which is derived from offshore water at depths of 50-100 m. Water-mass analysis reveals that upwelled water is advected equatorward from its source. Some upwelled water is transported into shallow coastal areas and warmed. Alongshelf fronts between relatively warm, low-salinity (> 13-degrees-C, < 33.5 psu) offshore water and cool, higher-salinity upwelled water are advected offshore in response to wind relaxation or reversal events; frontal gradients intensify at these times. AVHRR imagery verifies the spatial patterns and complex mesoscale variability of the near-surface patterns observed in the CTD survey data. Eddylike hydrographic features are noted with horizontal scales on the order of the station spacing (10 km). How the complex circulation patterns and intense mesoscale spatial and temporal variability affect the survival and subsequent recruitment of juvenile groundfish is discussed. RP SCHWING, FB (reprint author), SW FISHERIES SCI CTR,PACIFIC FISHERIES ENVIRONM GRP,POB 831,MONTEREY,CA 93942, USA. NR 0 TC 38 Z9 38 U1 0 U2 0 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD NOV PY 1991 VL 32 BP 47 EP 62 PG 16 WC Fisheries SC Fisheries GA GZ763 UT WOS:A1991GZ76300005 ER PT J AU MASON, JE AF MASON, JE TI VARIATIONS IN THE CATCH OF JACK MACKEREL IN THE SOUTHERN CALIFORNIA PURSE SEINE FISHERY SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article AB Jack mackerel landings from southern California sampled by the California Department of Fish and Game show a high degree of variability in recruitment success. The period from 1947 to 1983 is examined for variations in landings due to changes in fishing effort of the multispecies purse seine fishery. Fishing effort for jack mackerel has been affected by the availability of alternative species such as Pacific sardine and Pacific mackerel, and by economic factors including cannery capacity and the price of imported mackerel. Significant variations in recruitment success are apparent. Above-average recruitment for jack mackerel and Pacific mackerel, both pelagic species in southern California waters, often occurs in the same years. The age composition of jack mackerel landings has changed noticeably during this period. Before 1965, fish three years old or older contributed significantly to the fishery, but after 1965 the fishery was dominated by one- and two-year-old fish. The seasonal nature of the multispecies fishery and the decreased contribution of older fish from the fall fishery are reflected in this change in age composition. Other factors include economic effects, the frequency of relatively strong year classes, shifts in the areas fished, and possible changes in fish behavior. RP MASON, JE (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,PACIFIC FISHERIES ENVIRONM GRP,POB 831,MONTEREY,CA 93942, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD NOV PY 1991 VL 32 BP 143 EP 151 PG 9 WC Fisheries SC Fisheries GA GZ763 UT WOS:A1991GZ76300012 ER PT J AU NACKERDIEN, Z KASPRZAK, KS RAO, G HALLIWELL, B DIZDAROGLU, M AF NACKERDIEN, Z KASPRZAK, KS RAO, G HALLIWELL, B DIZDAROGLU, M TI NICKEL(II)-DEPENDENT AND COBALT(II)-DEPENDENT DAMAGE BY HYDROGEN-PEROXIDE TO THE DNA BASES IN ISOLATED HUMAN CHROMATIN SO CANCER RESEARCH LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; CARCINOGENIC NICKEL COMPOUNDS; RADICAL FORMATION; DEOXYRIBONUCLEIC-ACID; PROTEIN CROSSLINKS; COBALT; HYDROXYL; SUPEROXIDE; OXIDATION; METAL AB Nickel compounds are known to be carcinogenic to humans and animals. Cobalt compounds produce tumors in animals and are probably carcinogenic to humans. The mechanisms of the carcinogenicity of these metal compounds, however, have remained elusive. In the present work, we have investigated the ability of Ni(II) and Co(II) ions in the presence of H2O2 to cause chemical changes in DNA bases in chromatin extracted from cultured cells of human origin. Eleven modified DNA bases in chromatin were identified and quantitated by the use of gas chromatography-mass spectrometry. 2-Hydroxyadenine (isoguanine), which has not previously been shown to occur in DNA or chromatin, was also identified. Products identified were typical hydroxyl radical-induced products of DNA bases, suggesting that the hydroxyl radical was involved in their formation. This idea was supported by partial inhibition of product formation by typical scavengers of hydroxyl radical. Partial inhibition of product formation indicated a possible "site-specific" formation of hydroxyl radical by unchelated Ni(II) and Co(II) ions bound to chromatin. Although treatment of chromatin for 1 h with Co(II)/H2O2 caused formation of significant amounts of products, treatment with Ni(Il)/H2O2 required incubation times of more than 5 h and an increase in Ni(II) concentration before increases in product amounts above background levels became detectable. In both cases, ascorbic acid did not increase product yields. Glutathione at a physiologically relevant concentration had little overall effect on DNA base modification. Superoxide dismutase increased the yields of most products. Chelation of Ni(II) and Co(II) ions with EDTA almost completely inhibited product formation. Ni(II) in the presence of H2O2 produced greater base damage to the DNA in chromatin than to isolated DNA, unlike other metal ions tested. DNA damage in chromatin caused by Ni(II) and Co(II) ions in the presence Of H2O2 May contribute to the established genotoxicity and carcinogenicity of these metal ions. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV STELLENBOSCH,DEPT RADIOTHERAPY,TYGERBERG 7505,SOUTH AFRICA. UNIV MARYLAND,BALTIMORE,MD 21201. MARYLAND BIOTECHNOL INST,CTR MED BIOTECHNOL,BALTIMORE,MD 21228. NCI,FREDERICK CANC RES DEV CTR,COMPARAT CARCINOGENESIS LAB,FREDERICK,MD 21702. UNIV CALIF DAVIS,SACRAMENTO MED CTR,SACRAMENTO,CA 95817. RI Halliwell, Barry/C-8318-2009 NR 57 TC 115 Z9 116 U1 0 U2 2 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD NOV 1 PY 1991 VL 51 IS 21 BP 5837 EP 5842 PG 6 WC Oncology SC Oncology GA GM477 UT WOS:A1991GM47700010 PM 1933852 ER PT J AU CHOW, LC TAKAGI, S AF CHOW, LC TAKAGI, S TI DEPOSITION OF FLUORIDE ON TOOTH SURFACES BY A 2-SOLUTION MOUTHRINSE INVITRO SO CARIES RESEARCH LA English DT Article DE CALCIUM FLUORIDE; DENTAL CARIES; ENAMEL; FLUORIDE MOUTHRINSE; FLUORIDE UPTAKE; REMINERALIZATION; TOPICAL FLUORIDE APPLICATION ID CALCIUM-FLUORIDE; ENAMEL INVIVO; KINETICS; PLAQUE; ACQUISITION; NAF AB A constant-composition fluoride (F) titration method was used to measure the amount of leachable F deposited on tooth surfaces in vitro by a 1-min rinse with a 228-ppm F solution (12 mmol/l sodium fluoride). The mean F uptake was 0.23 +/- (SE) 0.07-mu-g/cm2, corresponding to less than 0.2% of the F contained in the rinse. The present study describes a new F rinse system that consisted of two solutions. Solution A contained a soluble calcium salt and a buffer. Solution B contained sodium fluorosilicate, a complex fluoride salt. When solutions A and B were combined, the free F ions produced by hydrolysis of fluorosilicate caused precipitation of calcium fluoride during the 1-min application time. The F uptake produced by the two-solution rinse was 4.36 +/- 0.16-mu-g/cm2, which was approximately 19 times greater than that produced by the sodium F rinse with the same F content. Since the cariostatic effects from F rinses are believed to derive from their ability to deposit labile F in the oral cavity, the two-solution rinse may be more efficacious than the rinses currently in use. RP CHOW, LC (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,PAFFENBARGER RES CTR,AMER DENT ASSOC,HLTH FDN,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [DE05354] NR 21 TC 20 Z9 20 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD NOV-DEC PY 1991 VL 25 IS 6 BP 397 EP 401 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA GT094 UT WOS:A1991GT09400001 PM 1810650 ER PT J AU BENTZ, DP GARBOCZI, EJ AF BENTZ, DP GARBOCZI, EJ TI PERCOLATION OF PHASES IN A 3-DIMENSIONAL CEMENT PASTE MICROSTRUCTURAL MODEL - REPLY SO CEMENT AND CONCRETE RESEARCH LA English DT Discussion RP BENTZ, DP (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD, USA. NR 3 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD NOV PY 1991 VL 21 IS 6 BP 1187 EP 1188 DI 10.1016/0008-8846(91)90082-S PG 2 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA GM904 UT WOS:A1991GM90400028 ER PT J AU STEVENS, BG MUNK, JE AF STEVENS, BG MUNK, JE TI LATERAL ASYMMETRY IN THE THORACIC SEGMENTATION OF A KING CRAB, PARALITHODES-CAMTSCHATICUS (TILESIUS, 1815) (DECAPODA, ANOMURA), FROM KODIAK, ALASKA SO CRUSTACEANA LA English DT Note ID BILATERAL GYNANDROMORPH RP STEVENS, BG (reprint author), KODIAK LAB,ALASKA FISHERIES SCI CTR,NATL MARINE FISHERIES SERV,POB 1638,KODIAK,AK 99615, USA. NR 8 TC 7 Z9 8 U1 0 U2 1 PU E J BRILL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0011-216X J9 CRUSTACEANA JI Crustaceana PD NOV PY 1991 VL 61 BP 317 EP 320 DI 10.1163/156854091X00218 PN 3 PG 4 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GP245 UT WOS:A1991GP24500011 ER PT J AU SHERMAN, K AF SHERMAN, K TI THE LARGE MARINE ECOSYSTEM CONCEPT - RESEARCH AND MANAGEMENT STRATEGY FOR LIVING MARINE RESOURCES SO ECOLOGICAL APPLICATIONS LA English DT Article DE BIOMASS YIELDS; FISHERIES; LARGE MARINE ECOSYSTEMS; LAW OF THE SEA; LIVING MARINE RESOURCES; MANAGEMENT; OVEREXPLOITATION; PERTURBATIONS; RESEARCH; REGIONAL; SCALE ID NORTHWEST ATLANTIC AB The principles adopted by coastal nations under the terms of the United Nations Convention for the Law of the Sea (UNCLOS) have been interpreted as supportive of the management of living marine resources from an ecosystems perspective. Large marine ecosystems (LMEs) are described as regional units for the conservation and management of living marine resources in accordance with the legal mandates of UNCLOS. The principal forces driving large-scale changes in living marine resources vary among LMEs. Progress in the research and management of living marine resources and their biomass yields can be enhanced by comparing the multiple stable states among LMEs with regard to the causes of stress or perturbation on the system and the feedback of the system to stress. Ecological considerations that are presently shaping the management of biomass yields in several LMEs in the Pacific, Atlantic, and Southern Oceans are discussed. RP SHERMAN, K (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,NARRAGANSETT LAB,NARRAGANSETT,RI 02882, USA. NR 71 TC 70 Z9 71 U1 0 U2 6 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1991 VL 1 IS 4 BP 349 EP 360 DI 10.2307/1941896 PG 12 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA GQ189 UT WOS:A1991GQ18900001 PM 27755673 ER PT J AU DANOS, M BELYAEV, VB AF DANOS, M BELYAEV, VB TI ESTIMATE OF THE NEUTRON TRANSFER FUSION RATE SO FUSION TECHNOLOGY LA English DT Note DE COLD FUSION; NEUTRON TRANSFER; VIRTUAL COMPTON EFFECT ID COLD FUSION AB The e4-order quantum electrodynamic term for neutron transfer fusion is 10(40) to 10(50) times larger than the direct term, suggesting that room-temperature fusion does not contradict nonexotic physics. C1 DUBNA JOINT NUCL RES INST,DUBNA,USSR. RP DANOS, M (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1991 VL 20 IS 3 BP 354 EP 357 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA GM943 UT WOS:A1991GM94300009 ER PT J AU MCCORMICK, SD DICKHOFF, WW DUSTON, J NISHIOKA, RS BERN, HA AF MCCORMICK, SD DICKHOFF, WW DUSTON, J NISHIOKA, RS BERN, HA TI DEVELOPMENTAL DIFFERENCES IN THE RESPONSIVENESS OF GILL NA+,K+-ATPASE TO CORTISOL IN SALMONIDS SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID K+-ATPASE ACTIVITY; COHO SALMON; ONCORHYNCHUS-KISUTCH; GROWTH-HORMONE; ATLANTIC SALMON; SAROTHERODON-MOSSAMBICUS; SMOLT TRANSFORMATION; SEAWATER ADAPTATION; PLASMA PROLACTIN; THYROID-HORMONES C1 UNIV CALIF BERKELEY,DEPT INTEGRAT BIOL,BERKELEY,CA 94720. UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98195. UNIV WASHINGTON,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,SEATTLE,WA 98112. FISHERIES & OCEANS CANADA,ST ANDREWS BIOL STN,ST ANDREWS E0G 2X0,NB,CANADA. NR 30 TC 53 Z9 54 U1 1 U2 8 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0016-6480 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD NOV PY 1991 VL 84 IS 2 BP 308 EP 317 DI 10.1016/0016-6480(91)90054-A PG 10 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA GM684 UT WOS:A1991GM68400014 PM 1664399 ER PT J AU CHARLOU, JL BOUGAULT, H APPRIOU, P NELSEN, T RONA, P AF CHARLOU, JL BOUGAULT, H APPRIOU, P NELSEN, T RONA, P TI DIFFERENT TDM/CH4 HYDROTHERMAL PLUME SIGNATURES - TAG SITE AT 26-DEGREES-N AND SERPENTINIZED ULTRABASIC DIAPIR AT 15-DEGREES-05'N ON THE MID-ATLANTIC RIDGE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT SPECIAL SESSION OF THE 21ST LUNAR AND PLANETARY SCIENCE CONF : THE MACALPINE HILLS LUNAR METEORITE CONSORTIUM CY MAR 12, 1990 CL HOUSTON, TX ID NORTHEAST PACIFIC-OCEAN; SUSPENDED PARTICLES; MASSIVE SULFIDES; HYDROGEN GAS; EXCESS HE-3; RIFT-VALLEY; FUCA RIDGE; SEA-WATER; MANGANESE; METHANE AB As a part of the 1988 NOAA VENTS Program, CH4 and Mn tracers were used to identify and compare hydrothermal plumes found above the TAG Field (26-degrees-N) and in the rift valley at 15-degrees-N close to the eastern intersection of the ridge axis with the 15-degrees 20'N Fracture Zone at the Mid-Atlantic Ridge (MAR). Active hydrothermal venting was confirmed at TAG, based on elevated concentrations of total dissolved Mn (TDM up to 30 nmol/kg), high CH4 concentrations (up to 200 nL/L), and elevated nephelometry signals. Plumes of a different composition were identified at 15-degrees-N with high CH4 concentrations (up to 400 nL/L), low total dissolved Mn concentrations (TDM < 1 nmol/kg) and no significant nephelometry signal. The different properties of these tracers and the different tracer ratios can be used to deduce vent fluid characteristics and compare one hydrothermal area to another. TDM/CH4 and Nephel/CH4 ratios at TAG are of the same order of magnitude as those observed at other spreading axis hydrothermal fields. At 15-degrees-N, the low TDM/CH4 ratio provides evidence of fluid circulation into ultrabasic rocks and offers a potentially useful and single method of exploring for hydrothermal activity associated with serpentinization. Mantle degassing through hydrothermal activity associated with serpentinization is an important process with respect to chemical and thermal exchanges between the upper mantle and the ocean. Different ratios of hydrothermal tracers (i.e., TDM/CH4) provide a useful framework for identifying subseafloor processes along mid-oceanic ridges. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,OCD,MIAMI,FL 33149. UNIV BRETAGNE OCCIDENTALE,F-29279 BREST,FRANCE. RP CHARLOU, JL (reprint author), IFREMER,CTR BREST,DEPT GEOSCI MARINES,BP 70,F-29280 PLOUZANE,FRANCE. NR 84 TC 68 Z9 72 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD NOV PY 1991 VL 55 IS 11 BP 3209 EP 3222 DI 10.1016/0016-7037(91)90484-M PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GT024 UT WOS:A1991GT02400017 ER PT J AU LI, XL SPEISER, TW AF LI, XL SPEISER, TW TI AN ESTIMATION OF THE ELECTRIC-FIELD IN THE MAGNETOTAIL CURRENT SHEET USING THE OBSERVED ENERGETIC ION BULK FLOW SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MARCH 22; CDAW-6; SUBSTORM AB It is important to know the electric field in the tail current sheet in order to understand how particles behave and how much energy is being dissipated. The electric field is also a measurement of the reconnection rate during substorms. For the CDAW-6 substorm period of March 22, 1979, we used the ion data from the medium energy particles experiment (MEPE) on the ISEE-1 satellite, and studied nine measurements of the 3D distribution function centered on the center of the current sheet. The measured distribution function was then integrated to obtain the average of bulk flow velocity in the geocentric solar ecliptic (GSE) frame. This bulk flow velocity was then broken up into its components perpendicular and parallel to the magnetic field for the nine cases. It was further assumed that the perpendicular component was due, in part, to an energy dependent drift and to an energy independent electric field drift. Using the bulk flow velocities from any two energy channels we can separate out the electric and energy dependent drifts and thus obtain electric field and energy dependent components. The two lowest energy channels (34.3 keV and 54.9 keV) give the main results, and the 80.4 keV and 118.8 keV channels are used as a cross check. We find that E(x) fluctuates approximately +/- 5 mV/m, and E(y) +/- 10 mV/m, in reasonable agreement with measurements by the electric field instrument [Pedersen et al., 1985], with most of the fluctuation presumably due to the motion of the current sheet. Using current sheet oscillation theory and the central current sheet data points, we can estimate E(y) in the frame of the current sheet and find a positive average E(y) with a magnitude of almost-equal-to 0.1 mV/m, which is also consistent with that expected for reconnection in this substorm time period. The E(z) component has a remarkable linear correlation with B(x), with a correlation coefficient of 0.91. Assuming B(x) varies linearly with z, a positive ion density of 3.14 x 10(-20)/d(R(e)) Coulombs/m3 is implied. Such a positive space charge near the current sheet center is expected theoretically. C1 NOAA,SEL,BOULDER,CO 80309. RP LI, XL (reprint author), UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309, USA. NR 14 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV PY 1991 VL 18 IS 11 BP 1967 EP 1970 DI 10.1029/91GL01999 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500010 ER PT J AU GOBBI, GP DESHLER, T ADRIANI, A HOFMANN, DJ AF GOBBI, GP DESHLER, T ADRIANI, A HOFMANN, DJ TI EVIDENCE FOR DENITRIFICATION IN THE 1990 ANTARCTIC SPRING STRATOSPHERE .1. LIDAR AND TEMPERATURE-MEASUREMENTS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ACID AEROSOL FORMATION; INSITU ER-2 DATA; NITRIC-ACID; BALLOON OBSERVATIONS; ARCTIC STRATOSPHERE; TRACE GASES; OZONE; DESTRUCTION; DEPLETION; NITROGEN AB Lidar soundings of the lower stratosphere were made between August 30 and October 11, 1990, at McMurdo Station, Antarctica (78S-167E). Polar stratospheric clouds (PSCs) were observed in only two periods: between September 5 and 10, and on October 7. During these days McMurdo was well within the polar vortex, and temperatures in the lower stratosphere reached seasonal minima. Temperature soundings and two water vapor measurements were also made in the same period. The water vapor content between 11 and 20 km was found to be between 2 and 3 ppmv. Using these values for water vapor, condensation temperatures for water and nitric acid trihydrate were calculated and compared with the temperature measurements. Analysis of these comparisons together with the lidar observations indicated that PSCs appeared only when temperatures were below the threshold condensation point for an air mass containing approximately 1 ppbv nitric acid. This was observed from the beginning of measurements on August 30, and suggests that the Antarctic lower stratosphere was highly denitrified both at the end of winter and during the early spring of 1990. C1 UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP GOBBI, GP (reprint author), CNR,IST FIS ATMOSFERA,CP27,I-00044 FRASCATI,ITALY. NR 17 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV PY 1991 VL 18 IS 11 BP 1995 EP 1998 DI 10.1029/91GL02310 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500017 ER PT J AU DESHLER, T ADRIANI, A HOFMANN, DJ GOBBI, GP AF DESHLER, T ADRIANI, A HOFMANN, DJ GOBBI, GP TI EVIDENCE FOR DENITRIFICATION IN THE 1990 ANTARCTIC SPRING STRATOSPHERE .2. LIDAR AND AEROSOL MEASUREMENTS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BALLOON AB Balloonborne aerosol soundings from McMurdo Station, Antarctica in 1990, documented the occurrence of polar stratospheric clouds (PSCs) during both fast and slow cooling events as well as the background stratospheric sulfate aerosol. PSCs formed under slow cooling predominated and in this case the size distributions were found to be bimodal with mode radii of 0.08 and 2 - 3-mu-m, similar to previous measurements in Antarctica. The aerosol soundings were also compared to lidar measurements at McMurdo in three cases. In the one PSC layer formed from fast cooling, the best agreement between measured and calculated scattering ratio was found using an index of refraction of 1.37, suggesting an amorphous nitric acid/water composition rather than crystalline nitric acid trihydrate. For the background aerosol, calculations using an index of 1.5 were generally in best agreement with the measured values. C1 CNR,IST FIS ATMOSFERA,I-00044 FRASCATI,ITALY. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP DESHLER, T (reprint author), UNIV WYOMING,DEPT CARDIOVASC STUDIES,LARAMIE,WY 82071, USA. OI Adriani, Alberto/0000-0003-4998-8008 NR 10 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV PY 1991 VL 18 IS 11 BP 1999 EP 2002 DI 10.1029/91GL02311 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GP755 UT WOS:A1991GP75500018 ER PT J AU BAKUN, A PARRISH, RH AF BAKUN, A PARRISH, RH TI COMPARATIVE-STUDIES OF COASTAL PELAGIC FISH REPRODUCTIVE HABITATS - THE ANCHOVY (ENGRAULIS-ANCHOITA) OF THE SOUTHWESTERN ATLANTIC SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article ID SHELF; WIND; OCEAN; ABUNDANCE; FRONTS; BRAZIL; FIELD; SEA RP BAKUN, A (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,PACIFIC FISHERIES ENVIRONM GRP,POB 831,MONTEREY,CA 93942, USA. OI Bakun, Andrew/0000-0002-4366-3846 NR 58 TC 94 Z9 97 U1 0 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 NOV PY 1991 VL 48 IS 3 BP 343 EP 361 DI 10.1093/icesjms/48.3.343 PG 19 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA GY936 UT WOS:A1991GY93600008 ER PT J AU MA, MT LARSEN, EB CRAWFORD, ML AF MA, MT LARSEN, EB CRAWFORD, ML TI ELECTROMAGNETIC-FIELDS WITH ARBITRARY WAVE IMPEDANCES GENERATED INSIDE A TEM CELL SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Note AB Standard electromagnetic fields having a wide range of chosen wave impedances, and generated inside a TEM cell for rf susceptibility testing, have many potential applications. We propose to achieve this desired type of field by exciting one port of the TEM, as usual, but terminating the other port with an intentionally unmatched load impedance. Experimental results together with necessary theoretical justifications are presented. RP MA, MT (reprint author), NIST,BOULDER,CO 80303, USA. NR 9 TC 7 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1991 VL 33 IS 4 BP 358 EP 362 DI 10.1109/15.99118 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA GK638 UT WOS:A1991GK63800011 ER PT J AU PALMER, AJ AF PALMER, AJ TI SURFACE CURRENT MAPPING PERFORMANCE OF BISTATIC AND MONOSTATIC DELTA-K-RADARS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Note ID FREQUENCY RP PALMER, AJ (reprint author), UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,NOAA,ENVIRONM RES LAB,BOULDER,CO 80303, USA. NR 6 TC 3 Z9 3 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD NOV PY 1991 VL 29 IS 6 BP 1014 EP 1016 DI 10.1109/36.101379 PG 3 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA GN485 UT WOS:A1991GN48500020 ER PT J AU BLUE, JL SCHEINFEIN, MR AF BLUE, JL SCHEINFEIN, MR TI USING MULTIPOLES DECREASES COMPUTATION TIME FOR MAGNETOSTATIC SELF-ENERGY SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK ID FILMS AB The calculation of the magnetostatic self-energy and field is the most computationally intensive aspect of micromagnetics simulations. The computation time is proportional to N2, where N is the number of cells in the discretized problem. We have implemented an algorithm that uses multipole expansions of the field integrals for cells suitably far from the field evaluation point. The computation time is asymptotically proportional to NlogN. We demonstrate our implementation by computing the micromagnetic structure of domain walls in both thin and thick ferromagnetic films. C1 ARIZONA STATE UNIV,CTR SOLID STATE SCI,TEMPE,AZ 85287. RP BLUE, JL (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 7 TC 24 Z9 24 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 1991 VL 27 IS 6 BP 4778 EP 4780 DI 10.1109/20.278944 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100045 ER PT J AU SCHEINFEIN, MR BLUE, JL AESCHLIMANN, M AF SCHEINFEIN, MR BLUE, JL AESCHLIMANN, M TI MICROMAGNETICS OF SURFACE SEGREGATION REGIONS IN DOMAINS WRITTEN IN TBFECO ALLOYS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK ID SCANNING ELECTRON-MICROSCOPY; POLARIZATION ANALYSIS; FILMS AB Domains written in thin films of TbFeCo were observed with scanning electron microscopy with polarization analysis (SEMPA). The SEMPA measurements revealed that the rare earth concentration has a direct effect on the orientation of the surface magnetization which is tilted with respect to the sample normal due to segregation and oxidation processes. We modeled the magnetic microstructure of domains in thermal equilibrium by solving the Landau-Lifshitz-Gilbert equations. Our simple model of the surface has a thin layer of Fe-rich material near the surface with magnetic properties different from those in bulk. We examine the surface micromagnetic properties for various surface layer thicknesses and magnetic parameters. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV ROCHESTER,DEPT CHEM,ROCHESTER,NY 14627. RP SCHEINFEIN, MR (reprint author), ARIZONA STATE UNIV,CTR SOLID STATE SCI,TEMPE,AZ 85287, USA. RI Aeschlimann, Martin/D-7141-2011 OI Aeschlimann, Martin/0000-0003-3413-5029 NR 9 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 1991 VL 27 IS 6 BP 5124 EP 5126 DI 10.1109/20.278761 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100157 ER PT J AU RICE, P MORELAND, J AF RICE, P MORELAND, J TI TUNNELING STABILIZED MAGNETIC FORCE MICROSCOPY OF YBA2CU3O7-DELTA FILMS ON MGO AT 76-K SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 5TH JOINT MMM-INTERMAG CONF CY JUN 18-21, 1991 CL PITTSBURGH, PA SP AKASHIC MEMORIES, ALLEGHENY LUDLUM, ALLIED SIGNAL, APPL MAGNET, ARMCO, ANORD ENGN, BASF AG, CERAM MAGNET, CRUCIBLE MAT, DASTEK AB Tunneling Stabilized Magnetic force microscopy (TSMFM) is an elementary variation of scanning tunneling microscopy (STM). As in STM, a sharp conductive tip is scanned across a conductive sample with an electrical potential applied. As the tip is scanned, changes in tunneling current are plotted on a computer screen as a topographical image. The difference between STM and TSMFM is that the TSMFM tip is made from a flexible magnetic film which deflects in response to sample surface magnetic forces. Pinning of the Abrikosov flux lattice in high temperature superconductors determines the critical current. We have applied TSMFM for these high temperature superconductors. We present images of sputter deposited YBa2Cu3O7-delta films below the critical temperature. RP RICE, P (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 1991 VL 27 IS 6 BP 5181 EP 5183 DI 10.1109/20.278780 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA HB661 UT WOS:A1991HB66100176 ER PT J AU GLOSIK, J TWIDDY, ND JAVAHERY, G FERGUSON, EE AF GLOSIK, J TWIDDY, ND JAVAHERY, G FERGUSON, EE TI MEASUREMENT OF THE EQUILIBRIUM-CONSTANT OF THE REACTION HEH++NE REVERSIBLE NEH++HE IN A SELECTED ION FLOW TUBE SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article ID AFFINITY AB The reaction HeH+ + Ne half-arrow-right-over-half-arrow-left NeH+ + He has been studied using a selected ion flow tube apparatus in Aberystwyth. For small Ne flows, the forward reaction can be measured to give a rate constant, 1.25(-9) cm3 s-1. For large Ne concentrations in the tube the reaction reaches equilibrium, giving an equilibrium constant K = 33 000 +/- 20%, where the +/- 20% is a rather conservative estimate of the precision, the data scatter being far less than this. This yields DELTA-G-degrees = -6.1 +/- 0.1 kcal mol-1 or DELTA-H-degrees = -6.3 +/- 0.1 kcal mol-1 = 0.275 +/- 0.004 eV. This is equal to the differences in bond energies. D0(NeH+) - D0(HeH+) or proton affinities, PA(Ne) - PA(He). C1 UNIV COLL WALES,DEPT PHYS,ABERYSTWYTH SY23 3BZ,WALES. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP GLOSIK, J (reprint author), CHARLES UNIV,FAC MATH & PHYS,DEPT ELECTR & VACUUM PHYS,CS-11636 PRAGUE 1,CZECHOSLOVAKIA. NR 10 TC 5 Z9 5 U1 1 U2 1 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 1 PY 1991 VL 109 BP 75 EP 81 DI 10.1016/0168-1176(91)85097-6 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GN866 UT WOS:A1991GN86600006 ER PT J AU MAUTNER, MMN SIECK, LW AF MAUTNER, MMN SIECK, LW TI EQUILIBRIUM STUDIES BY PULSED HIGH-PRESSURE MASS-SPECTROMETRY - A CALIBRATION, AND SOME PITFALLS AND SOLUTIONS SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article ID BOND-DISSOCIATION ENERGIES; PHASE HYDRATION REACTIONS; METHYL CATION AFFINITIES; ION-MOLECULE ASSOCIATION; GAS-PHASE; THERMAL-DECOMPOSITION; ELECTRON-AFFINITIES; PROTONATED ALCOHOLS; INTRINSIC ACIDITIES; ENTROPY CHANGES AB The accuracy of pulsed high pressure mass spectrometry (PHPMS) thermochemical measurements was assessed using a ladder of charge transfer equilibria involving aromatic molecules. The ladder was constructed using DELTA-H-degrees values from variable temperature measurements. For the 14 compounds in the ladder, the average agreement of the equilibrium results with spectroscopic ionisation potentials (IPs) is +/- 0.6 kcal mol-1. Over the span of the ladder, from 1,2,3,5-tetramethylbenzene to C6F6, the thermochemical ladder yields a DELTA-IP of 40.7 kcal mol-1, compared with the spectroscopic value of 42.3 kcal mol-1 i.e., the equilibrium values cover the span of 40 kcal mol-1 with an accuracy of +/- 5%. The sources of error in these studies are evaluated, and some common pitfalls in PHPMS studies are discussed. These include: steady states that appear as equilibria; isomerisation; pyrolysis of ions and neutrals; slow reactions and non-reactive systems; reactions outside the ion source; vapor pressure problems; and mass coincidences. Tests and solutions for these complications are also discussed. RP MAUTNER, MMN (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 42 TC 22 Z9 22 U1 0 U2 1 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 1 PY 1991 VL 109 BP 187 EP 208 DI 10.1016/0168-1176(91)85104-T PG 22 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GN866 UT WOS:A1991GN86600013 ER PT J AU PERKINS, RA FRIEND, DG RODER, HM DECASTRO, CAN AF PERKINS, RA FRIEND, DG RODER, HM DECASTRO, CAN TI THERMAL-CONDUCTIVITY SURFACE OF ARGON - A FRESH ANALYSIS SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE ARGON; LIQUID; SUPERCRITICAL; SURFACE FIT; THERMAL CONDUCTIVITY; TRANSIENT HOT WIRE TECHNIQUE; VAPOR ID MODERATELY DENSE GAS; ABSOLUTE DETERMINATION; TRANSPORT-PROPERTIES; CRITICAL REGION; LIQUID ARGON; NOBLE-GASES; ROOM-TEMPERATURE; PRESSURES; MPA; NITROGEN AB This paper presents a fresh analysis of the thermal conductivity surface of argon at temperatures between 100 and 325 K with pressures up to 70 MPa. The new analysis is justified for several reasons. First, we discovered an error in the compression-work correction, which is applied when calculating thermal conductivity and thermal diffusivity obtained with the transient hot-wire technique. The effect of the error is limited to low densities, i.e., for argon below 5 mol.L-1. The error in question centers on the volume of fluid exposed to compression work. Once corrected, the low-density data agree very well with the available theory for both dilute-gas thermal conductivity and the first density coefficient of thermal conductivity. Further, the corrected low-density data, if used in conjunction with our previously reported data for the liquid and supercritical dense-gas phases, allow us to represent the thermal conductivity in the critical region with a recently developed mode-coupling theory. Thus the new surface incorporates theoretically based expressions for the dilute-gas thermal conductivity, the first density coefficient, and the critical enhancement. The new surface exhibits a significant reduction in overall error compared to our previous surface which was entirely empirical. The uncertainty in the new thermal conductivity surface is +/- 2.2% at the 95% confidence level. C1 UNIV LISBON,FAC CIENCIAS,DEPT QUIM,P-1700 LISBON,PORTUGAL. INST SUPER TECN,CTR QUIM ESTRUTURAL,COMPLEXO I,P-1096 LISBON,PORTUGAL. RP PERKINS, RA (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. RI Nieto de Castro, Carlos/B-7377-2011; OI Nieto de Castro, Carlos/0000-0001-9011-5132; Perkins, Richard/0000-0002-8526-6742 NR 34 TC 35 Z9 35 U1 0 U2 6 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1991 VL 12 IS 6 BP 965 EP 984 DI 10.1007/BF00503513 PG 20 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA GJ712 UT WOS:A1991GJ71200002 ER PT J AU DECASTRO, CAN PERKINS, RA RODER, HM AF DECASTRO, CAN PERKINS, RA RODER, HM TI RADIATIVE HEAT-TRANSFER IN TRANSIENT HOT-WIRE MEASUREMENTS OF THERMAL-CONDUCTIVITY SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE RADIATIVE HEAT TRANSFER; THERMAL CONDUCTIVITY; TOLUENE; TRANSIENT HOT-WIRE TECHNIQUE ID STANDARD; BENZENE; TOLUENE AB New measurements of the thermal conductivity of liquid toluene between 300 and 550 K have been used to study the importance of radiative heat transfer when using the transient hot-wire technique. The experimental data were used to obtain the radiation correction to the hot-wire temperature rises. Radiation-corrected values of thermal conductivity are reported. This study shows that the transient hot-wire method is much less affected by radiation than steady-state techniques. C1 INST SUPER TECN,CTR QUIM ESTRUTURAL,COMPLEXO I,P-1096 LISBON,PORTUGAL. NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. RP DECASTRO, CAN (reprint author), UNIV LISBON,FAC CIENCIAS,DEPT QUIM,P-1700 LISBON,PORTUGAL. RI Nieto de Castro, Carlos/B-7377-2011; OI Nieto de Castro, Carlos/0000-0001-9011-5132; Perkins, Richard/0000-0002-8526-6742 NR 23 TC 30 Z9 30 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1991 VL 12 IS 6 BP 985 EP 997 DI 10.1007/BF00503514 PG 13 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA GJ712 UT WOS:A1991GJ71200003 ER PT J AU PAP, JM DONNELLY, RF HUDSON, HS ROTTMAN, GJ WILLSON, RC AF PAP, JM DONNELLY, RF HUDSON, HS ROTTMAN, GJ WILLSON, RC TI VARIABILITY OF SOLAR ULTRAVIOLET IRRADIANCE SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID FLUX AB A model of solar Lyman alpha irradiance developed by multiple linear regression analysis, including the daily values and 81-day running means of the full disk equivalent width of the Helium line at 1083 nm, predicts reasonably well both the short- and long-term variations observed in Lyman alpha. In contrast, Lyman alpha models calculated from the 10.7 cm radio flux overestimate the observed variations in the rising portion and maximum period of solar cycle, and underestimates them during solar minimum. We show models of Lyman alpha based on the He line equivalent width and 10.7 cm radio flux for those time intervals when no satellite observations exist, namely back to 1974 and after April 1989, when the measurements of the Solar Mesosphere Satellite were terminated. C1 NOAA,SEL,BOULDER,CO 80303. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92109. JET PROP LAB,PASADENA,CA 91103. UNIV COLORADO,LASP,BOULDER,CO 80309. RP PAP, JM (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 10 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 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD NOV-DEC PY 1991 VL 53 IS 11-12 BP 999 EP 1003 DI 10.1016/0021-9169(91)90045-9 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GX802 UT WOS:A1991GX80200003 ER PT J AU HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M AF HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M TI SOLAR AND INTERPLANETARY SHOCK EFFECTS ON THE FLUX AND ANISOTROPY PROFILES OF AN ENERGETIC STORM PARTICLE (ESP) EVENT OBSERVED ON 23-25 APRIL 1979 SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID PROTONS; UPSTREAM; SCATTERING; 35-KEV; PLANE; MHD; AU AB A large Energetic Storm Particle event was observed by ISEE-3 between 23 and 25 April 1979. This event was associated with an interplanetary shock which was generated by a solar disappearing filament. Flux and anisotropy profiles in the upstream region of the event have been reproduced by means of a particle propagation model which includes particle injection both at the Sun and at the shock front. Injection at the front takes into account the fact that the IMF connection between the shock and the spacecraft is disrupted by the shock itself. The model, coupled to a 2D MHD time-dependent model, makes it possible for us to study the parameters for the interplanetary propagation of the particles, the injection rates both at the Sun and at the shock front, from near the Sun out to 1 AU. C1 UNIV BARCELONA,DEPT ASTRON & METEOROL,E-08028 BARCELONA,SPAIN. NOAA,SPACE ENVIRON LAB,BOULDER,CO 80303. INST ESTUDIS CATALANS,ASTROFIS LAB,BARCELONA,SPAIN. RP HERAS, AM (reprint author), EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,DEPT SPACE SCI,POSTBUS 299,2200 AG NOORDWIJK,NETHERLANDS. RI xue, yansheng/A-9712-2012 NR 18 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD NOV-DEC PY 1991 VL 53 IS 11-12 BP 1027 EP 1032 DI 10.1016/0021-9169(91)90048-C PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GX802 UT WOS:A1991GX80200006 ER PT J AU HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M AF HERAS, AM SANAHUJA, B SMITH, ZK DETMAN, T DRYER, M TI ON THE LARGE-SCALE EFFECTS OF 2 INTERPLANETARY SHOCKS ON THE ASSOCIATED PARTICLE EVENTS SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID PROTONS; EVOLUTION; UPSTREAM; 35-KEV; PLANE; MHD AB An evolutionary model, including particle and shock propagation through the interplanetary medium, has been used to reproduce the evolution of the flux and anisotropy in the upstream region of two low-energy particle events observed by ISEE-3. These events, on 24 April 1979 and 18 February 1979, originated at solar (helio)longitudes almost-equal-to 50-degrees apart. By fitting the observed particle fluxes and anisotropies, the conditions for the propagation of the particles through the interplanetary medium and the injection rates at the shock have been determined as a function of time. The results are discussed in terms of the interplanetary magnetic field connection between the observer and the shock front and they are related to the heliolongitude of the parent solar activity. C1 UNIV BARCELONA,DEPT ASTRON & METEOROL,E-08028 BARCELONA,SPAIN. INST ESTUDIS CATALANS,ASTROFIS LAB,BARCELONA,SPAIN. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP HERAS, AM (reprint author), EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,DEPT SPACE SCI,POSTBUS 299,2200 AG NOORDWIJK,NETHERLANDS. RI xue, yansheng/A-9712-2012 NR 12 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD NOV-DEC PY 1991 VL 53 IS 11-12 BP 1033 EP 1038 DI 10.1016/0021-9169(91)90049-D PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GX802 UT WOS:A1991GX80200007 ER PT J AU BRUSH, LN MCFADDEN, GB CORIELL, SR AF BRUSH, LN MCFADDEN, GB CORIELL, SR TI LASER MELTING OF THIN SILICON FILMS SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID ZONE-MELTED SILICON; ONE-SIDED MODEL; DIRECTIONAL SOLIDIFICATION; CELLULAR GROWTH; INTERFACE MORPHOLOGIES; RECRYSTALLIZATION; SI; INSTABILITY; DYNAMICS; LIQUID AB Thin silicon films on a cooled substrate are often found to develop two-phase lamellar structures upon radiative heating. Jackson and Kurtze developed a two-dimensional model for the process in which the heated film consists of alternating parallel bands of liquid and solid phases separated by planar solid-liquid interfaces. To understand the cellular or dendritic structures that sometimes are observed in these interfaces, they also performed a linearized morphological stability analysis and obtained the conditions for the growth or decay of infinitesimal perturbations to the interface. In this work we extend that analysis to finite amplitudes by developing a boundary integral representation of the thermal field, and obtain steady-state numerical solutions for nonplanar solid-liquid interfaces. Eigenvalue calculations to determine the linear stability of the nonplanar solutions are also performed. The effects of the lateral boundary conditions on the stability of the solutions are investigated as well. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP BRUSH, LN (reprint author), UNIV WASHINGTON,DEPT MAT SCI & ENGN,SEATTLE,WA 98195, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 42 TC 8 Z9 8 U1 0 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 NOV PY 1991 VL 114 IS 3 BP 446 EP 466 DI 10.1016/0022-0248(91)90060-I PG 21 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA GT795 UT WOS:A1991GT79500021 ER PT J AU HARDY, SC MCFADDEN, GB CORIELL, SR VOORHEES, PW SEKERKA, RF AF HARDY, SC MCFADDEN, GB CORIELL, SR VOORHEES, PW SEKERKA, RF TI MEASUREMENT AND ANALYSIS OF GRAIN-BOUNDARY GROOVING BY VOLUME DIFFUSION SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID SURFACE-TENSION; FREE-ENERGIES; PB-SN; SYSTEMS AB Experimental measurements of isothermal grain boundary grooving by volume diffusion are carried out for Sn bicrystals in the Sn-Pb system near the eutectic temperature. The dimensions of the groove increase with a temporal exponent of 1/3, and measurement of the associated rate constant allows the determination of the product of the liquid diffusion coefficient D and the capillarity length-GAMMA associated with the interfacial free energy of the crystal-melt interface. We generalize the small-slope theory of Mullins to the entire range of dihedral angles by using a boundary integral formulation of the associated free boundary problem, and obtain excellent agreement with experimental groove shapes. By using the diffusivity measured by Jordan and Hunt, we deduce that our measured values of GAMMA agree to within 5% with the values obtained from experiments by Gunduz and Hunt on grain boundary grooving in a temperature gradient. C1 NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. CARNEGIE MELLON UNIV, DEPT PHYS, PITTSBURGH, PA 15213 USA. CARNEGIE MELLON UNIV, DEPT MATH, PITTSBURGH, PA 15213 USA. RP HARDY, SC (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008; Voorhees, Peter /B-6700-2009 OI McFadden, Geoffrey/0000-0001-6723-2103; NR 29 TC 22 Z9 22 U1 1 U2 9 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 NOV PY 1991 VL 114 IS 3 BP 467 EP 480 DI 10.1016/0022-0248(91)90061-9 PG 14 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA GT795 UT WOS:A1991GT79500022 ER PT J AU SMITH, DT AF SMITH, DT TI MEASURING CONTACT CHARGE-TRANSFER AT INTERFACES - A NEW EXPERIMENTAL-TECHNIQUE SO JOURNAL OF ELECTROSTATICS LA English DT Article AB A new experimental technique has been developed for measuring the amount of electric charge transferred when two dissimilar surfaces are brought into contact and separated without lateral motion in a controlled environment. The primary surfaces studied, silica and mica, are prepared with very low surface roughness (average roughness less than 0.5 nm); the macroscopic contact area, which can be measured directly, is therefore a better measure of microscopic contact area than is typically the case in contact electrification experiments, and the surface charge density can be more accurately determined. Observations reported include (1) the transfer of charge densities as high as 1 X 10(2) C/m2 after only a few contacts of a mica and silica surface in dry air or N2 gas at room temperature and (2) a reduction in transferred charge density in the silica-mica system as the relative humidity of the air in the environmental chamber is increased from 0% to 98%. The technique also permits the study of the rate at which the surface charge decays under various environmental conditions. RP SMITH, DT (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,BLDG 223,RM A335,GAITHERSBURG,MD 20899, USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 0 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 J9 J ELECTROSTAT JI J. Electrost. PD NOV PY 1991 VL 26 IS 3 BP 291 EP 308 DI 10.1016/0304-3886(91)90023-9 PG 18 WC Engineering, Electrical & Electronic SC Engineering GA GT811 UT WOS:A1991GT81100008 ER PT J AU WASSON, DH REPPOND, KD KANDIANIS, TM AF WASSON, DH REPPOND, KD KANDIANIS, TM TI ANTIOXIDANTS TO PRESERVE ROCKFISH COLOR SO JOURNAL OF FOOD SCIENCE LA English DT Article DE FISH; ROCKFISH; COLOR; STABILITY; ANTIOXIDANTS ID ASCORBIC-ACID AB Thornyhead rockfish, Sebastolobus alascanus, were treated with mixed tocopherols, alone or plus ascorbic acid (TCAA), butylated hydroxytoluene (BHT) and sodium erythorbate to preserve red skin color during frozen storage. While all treatments significantly improved color retention compared to the control, at 4 mo the TCAA treated fish had significantly higher red color scores than any other treatment group, as measured using the CIE L*a*b* scale. The TCAA dip also appeared to enhance the red color compared to pre-treatment values. C1 KODIAK FISH CO,KODIAK,AK. RP WASSON, DH (reprint author), NATL MARINE FISHERIES SERV,UTILIZAT RES LAB,POB 1638,KODIAK,AK 99615, USA. NR 13 TC 16 Z9 17 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 NOV-DEC PY 1991 VL 56 IS 6 BP 1564 EP 1566 DI 10.1111/j.1365-2621.1991.tb08641.x PG 3 WC Food Science & Technology SC Food Science & Technology GA GV361 UT WOS:A1991GV36100027 ER PT J AU SWARTZENDRUBER, LJ AF SWARTZENDRUBER, LJ TI PROPERTIES, UNITS AND CONSTANTS IN MAGNETISM SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article RP SWARTZENDRUBER, LJ (reprint author), NBS,GAITHERSBURG,MD 20234, USA. NR 7 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD NOV PY 1991 VL 100 IS 1-3 BP 573 EP 575 DI 10.1016/0304-8853(91)90841-W PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GX179 UT WOS:A1991GX17900034 ER PT J AU REED, RK GONZALEZ, FI MILLER, L AF REED, RK GONZALEZ, FI MILLER, L TI ON THE STRUCTURE AND STABILITY OF THE ALASKAN STREAM SO JOURNAL OF MARINE RESEARCH LA English DT Article ID GEOSTROPHIC CIRCULATION MODEL; NORTHEAST PACIFIC; KODIAK ISLAND; VARIABILITY; TRANSPORT; CURRENTS; GEOSAT; OCEAN AB Data from a year-long current mooring in the central region of the Alaskan Stream revealed an extremely stable flow unlike that in typical western boundary currents. Hydrographic and ADCP data also showed a simple flow free of excursions or eddies. These findings are in good agreement with a recent analytical model of the Stream. In addition, GEOSAT altimeter estimates of variability are consistent with the observations, suggesting that the results are valid in spite of the relatively large corrections applied at these high latitudes. C1 NOAA,NATL OCEAN SERV,ROCKVILLE,MD 20852. RP REED, RK (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Miller, Laury/B-8305-2011 OI Miller, Laury/0000-0003-3095-5804 NR 15 TC 4 Z9 4 U1 0 U2 0 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520 SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD NOV PY 1991 VL 49 IS 4 BP 719 EP 726 DI 10.1357/002224091784995684 PG 8 WC Oceanography SC Oceanography GA HE742 UT WOS:A1991HE74200005 ER PT J AU LEDBETTER, H MING, L AF LEDBETTER, H MING, L TI MONOCRYSTAL ELASTIC-CONSTANTS OF ORTHOTROPIC Y1BA2CU3O7 - AN ESTIMATE SO JOURNAL OF MATERIALS RESEARCH LA English DT Note ID YBA2CU3O7-DELTA SINGLE-CRYSTALS; BRILLOUIN SPECTROSCOPY; SOUND VELOCITIES; ULTRASOUND AB For Y1Ba2Cu3O7, using only reported monocrystal measurements and some analysis-theory, we estimated the complete nine-component orthotropic-symmetry elastic-stiffness matrix, the Voigt C(ij) matrix. Comparison with very-high-frequency tetragonal-symmetry phonon-dispersion results shows good agreement (9% on average), except for C-12. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 17 TC 86 Z9 86 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1991 VL 6 IS 11 BP 2253 EP 2255 DI 10.1557/JMR.1991.2253 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA GM828 UT WOS:A1991GM82800001 ER PT J AU MARTE, MAM CIRAC, JI ZOLLER, P AF MARTE, MAM CIRAC, JI ZOLLER, P TI DEFLECTION OF ATOMS BY CIRCULARLY POLARIZED-LIGHT BEAMS IN TRIPLE LAUE CONFIGURATION SO JOURNAL OF MODERN OPTICS LA English DT Article ID DIFFRACTION; WAVE AB A new type of atomic interferometer is discussed, in which atoms with two ground-state Zeeman sub-levels m = +/- 1, and an excited state with m = 0, pass through three laser interaction zones each comprising two counter-propagating waves of opposite circular polarization with a large detuning from resonance. By means of Raman-type transitions between the two ground-state levels, which convey a recoil of two photon momenta, the atomic wave function is split up into two coherent spatially separated branches, and subsequently recombined. In this system, conservation of energy and momentum leads to a strong correlation between the external centre of mass motion and internal magnetic degrees of freedom. As a consequence, the paths within the interferometer are tagged by the internal quantum number m. As an example, we calculate the position and momentum distribution function of a helium atom on its way through the interferometer. C1 UNIV COMPLUTENSE MADRID,DEPT OPT,MADRID 3,SPAIN. UNIV COLORADO,JOINT INST LAB ASTROPHYS,DEPT PHYS,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP MARTE, MAM (reprint author), UNIV INNSBRUCK,INST THEORET PHYS,A-6020 INNSBRUCK,AUSTRIA. RI Ritsch-Marte, Monika/A-4507-2010; Zoller, Peter/O-1639-2014 OI Zoller, Peter/0000-0003-4014-1505 NR 21 TC 10 Z9 10 U1 0 U2 1 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 NOV PY 1991 VL 38 IS 11 BP 2265 EP 2280 DI 10.1080/09500349114552321 PG 16 WC Optics SC Optics GA GQ037 UT WOS:A1991GQ03700013 ER PT J AU COHENTANNOUDJI, C PHILLIPS, WD AF COHENTANNOUDJI, C PHILLIPS, WD TI STANDING WAVES, ATOMS, AND VERY LOW-TEMPERATURES SO JOURNAL OF OPTICS-NOUVELLE REVUE D OPTIQUE LA French DT Article DE STANDING WAVES; OPTICAL PUMPING; COOLING ID PHOTON RECOIL ENERGY; OPTICAL MOLASSES; MULTILEVEL ATOMS; DOPPLER LIMIT; LASER; RADIATION; MOTION; LIGHT; VAPOR AB Momentum exchanges between atoms and standing waves have revealed unexpected effects of well known phenomena such as optical pumping and light shifts. One of the most enlightening results is cooling of atoms at temperature around a few microkelvins. C1 UNIV PARIS 06,F-75231 PARIS 05,FRANCE. NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RP COHENTANNOUDJI, C (reprint author), COLL FRANCE,ECOLE NORMALE SUPER,CNRS,SPECT HERTZIENNE LAB,24 RUE LHOMOND,F-75231 PARIS 05,FRANCE. NR 33 TC 0 Z9 0 U1 0 U2 0 PU MASSON EDITEUR PI PARIS 06 PA 120 BLVD SAINT-GERMAIN, 75280 PARIS 06, FRANCE SN 0150-536X J9 J OPT JI J. Opt.-Nouv. Rev. Opt. PD NOV-DEC PY 1991 VL 22 IS 6 BP 281 EP 290 DI 10.1088/0150-536X/22/6/004 PG 10 WC Optics SC Optics GA HP385 UT WOS:A1991HP38500004 ER PT J AU CHEW, F BUSHNELL, MH AF CHEW, F BUSHNELL, MH TI GEOSTROPHIC DEPARTURE, LOCAL TURNING, SPEED CHANGE, AND EDDY FLUX - A NEW PERSPECTIVE SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Note ID FLORIDA CURRENT; CURVATURE BIAS; TRANSPORT; VARIABILITY; RADAR AB Conjunctions of meander passages and cross-stream eddy momentum fluxes are common in western boundary currents. To explore the mechanism linking them, we offer a diagnostic equation of their time-dependent motions. The equation is embodied in the more explicit form of a hodograph with two characteristics: a tilt and a veering/backing. The veering/backing is in response to the changing geostrophic departure, and the tilt to the change in the speed of the flow, which can be zero, positive, or negative. This direct approach to the kinematic field-its pattern and its change-led to a hypothesis on the linkage that the cross-stream eddy momentum flux is driven by the downstream pressure gradient force in the supergeostrophic segment of the meandering flow. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,COOPERAT INST MARINE & ATMOSPHER STUDIES,MIAMI,FL 33149. NR 21 TC 0 Z9 0 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 NOV PY 1991 VL 21 IS 11 BP 1684 EP 1689 DI 10.1175/1520-0485(1991)021<1684:GDLTSC>2.0.CO;2 PG 6 WC Oceanography SC Oceanography GA GW421 UT WOS:A1991GW42100007 ER PT J AU KUTEPOV, AA KUNZE, D HUMMER, DG RYBICKI, GB AF KUTEPOV, AA KUNZE, D HUMMER, DG RYBICKI, GB TI THE SOLUTION OF RADIATIVE-TRANSFER PROBLEMS IN MOLECULAR BANDS WITHOUT THE LTE ASSUMPTION BY ACCELERATED LAMBDA ITERATION METHODS SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID OPERATORS; LEVEL AB An iterative method based on the use of approximate transfer (or LAMBDA) operators, which was designed initially to solve multilevel NLTE line formation problems in stellar atmospheres, is adapted and applied to the solution of the NLTE molecular band radiative transfer in planetary atmospheres. The matrices to be constructed and inverted are much smaller than those used in the traditional Curtis matrix technique, which makes possible the treatment of more realistic problems (including rotational NLTE, overlapping of lines in the bands and overlapping of bands with continuua) using relatively small computers. This technique converges much more rapidly than straightforward iteration between the transfer equation and the equations of statistical equilibrium (LAMBDA-iteration). A test application of this new technique to the solution of NLTE radiative transfer problems for optically-thick and thin bands (the 4.3-mu-m CO2 band in the Venusian atmosphere and the 4.7 and 2.3-mu-m CO bands in the Earth's atmosphere) is described. The necessity for careful treatment of rotational NLTE in weak lines of the 4.3-mu-m CO2 fundamental band is shown. The possible influence of neglecting or treating approximately the CO2 10-mu-m laser transitions and also effects of the overlap of the 4.3-mu-m CO2 with the continuum are investigated. The rotational NLTE effects in the 4.7-mu-m CO band in the upper Earth's atmosphere are estimated. C1 UNIV KARLSRUHE,KERNFORSCHUNGZENTRUM,INST METEOROL & KLIMAFORSCH,W-7500 KARLSRUHE 1,GERMANY. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. MAX PLANCK INST ASTROPHYS,W-8046 GARCHING,GERMANY. RP KUTEPOV, AA (reprint author), UNIV MUNICH,INST ASTRON & ASTROPHYS,SCHEINERSTR 1,W-8000 MUNICH 80,GERMANY. NR 17 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD NOV PY 1991 VL 46 IS 5 BP 347 EP 365 DI 10.1016/0022-4073(91)90038-R PG 19 WC Optics; Spectroscopy SC Optics; Spectroscopy GA GR458 UT WOS:A1991GR45800001 ER PT J AU WALKER, JH SAUNDERS, RD JACKSON, JK MIELENZ, KD AF WALKER, JH SAUNDERS, RD JACKSON, JK MIELENZ, KD TI RESULTS OF A CCPR INTERCOMPARISON OF SPECTRAL IRRADIANCE MEASUREMENTS BY NATIONAL LABORATORIES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CCPR; INTERCOMPARISON; NATIONAL LABORATORIES; RADIOMETRY; SPECTRAL IRRADIANCE; TUNGSTEN-HALOGEN LAMPS AB An intercomparison of spectral irradiance measurements by 12 national laboratories has been carried out between 1987 and 1990. The intercomparison was conducted under the auspices of the Comite Consultatif de Photometrie et Radiometrie (CCPR) of the Comite International des Poids et Mesures, and the National Institute of Standards and Technology (NIST) served as the pilot laboratory. The spectral range of the intercomparison was 250 to 2400 nm and the transfer standards used were commercial tungsten-halogen lamps of two types. The world-wide consistency of the results (one standard deviation) was on the order of 1% in the visible spectral region and 2 to 4% in the ultraviolet and infrared portions of the spectrum. The intercomparison revealed no statistically significant differences between spectral-irradiance scales based on blackbody physics and absolute detector radiometry. RP WALKER, JH (reprint author), NATL INST STAND & TECHNOL, DIV RADIOMETR PHYS, FACIL AUTOMATED SPECTRORADIOMETR CALIBRAT, GAITHERSBURG, MD 20899 USA. NR 7 TC 42 Z9 42 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 NOV-DEC PY 1991 VL 96 IS 6 BP 647 EP 668 DI 10.6028/jres.096.043 PG 22 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300001 PM 28184140 ER PT J AU LETTIERI, TR HARTMAN, AW HEMBREE, GG MARX, E AF LETTIERI, TR HARTMAN, AW HEMBREE, GG MARX, E TI CERTIFICATION OF SRM 1960 - NOMINAL 10 MU-M DIAMETER POLYSTYRENE SPHERES (SPACE BEADS) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ELECTRON MICROSCOPY; LENGTH; LIGHT SCATTERING; METROLOGY; MICROGRAVITY; MICROMETROLOGY; MICROSCOPY; MICROSPHERES; PARTICLES; PARTICLE SIZING; POLYSTYRENE SPHERES; REFERENCE MATERIALS; SIZING; STANDARDS ID LIGHT-SCATTERING; DIELECTRIC SPHERES; RESONANCES; SIZE AB Experimental, theoretical, and calculational details are presented for the three independent micrometrology techniques used to certify the mean diameter of Standard Reference Material 1960, nominal 10-mu-m diameter polystyrene spheres ("space beads"). The mean diameters determined by the three techniques agreed remarkably well, with all measurements within 0.1% of each other, an unprecedented achievement in the dimensional metrology of microspheres. Center distance finding (CDF), a method based on optical microscopy, gave a value of 9.89+/-0.04-mu-m, which was chosen to be the certified mean diameter. The supporting measurements were done using metrology electron microscopy (MEM) and resonance light scattering (RLS). The MEM technique, based on scanning electron microscopy, yielded 9.89+/-0.06-mu-m for the mean diameter of the microspheres in vacuum, while the RLS value was 9.90+/-0.03-mu-m for the microspheres in liquid suspension. The main peak of the diameter distribution for SRM 1960 is nearly Gaussian with a certified standard deviation of 0.09-mu-m, as determined by CDF. Off the main peak, there are about 1% oversized particles and a negligible amount of undersized particles. The report gives a detailed description of the apparatus, the experimental methods, the data-reduction techniques, and an error analysis for each of the micrometrology techniques. A distinctive characteristic rf this SRM is that it was manufactured in microgravity aboard the NASA space shuttle Challenger and is the first commercial product to be made in space. RP LETTIERI, TR (reprint author), NATL INST STAND & TECHNOL, MFG ENGN LAB, DIV PRECIS ENGN, GAITHERSBURG, MD 20899 USA. NR 30 TC 7 Z9 8 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 NOV-DEC PY 1991 VL 96 IS 6 BP 669 EP 691 DI 10.6028/jres.096.044 PG 23 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300002 PM 28184141 ER PT J AU HUTCHINSON, JMR UNTERWEGER, MP HODGE, PA AF HUTCHINSON, JMR UNTERWEGER, MP HODGE, PA TI CONSTRUCTION AND CALIBRATION OF THE NIST LARGE-AREA-SOURCE X-RAY COUNTING SYSTEM SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALIBRATION; EFFICIENCY CURVE; LARGE AREA SOURCE; PU-238; PROPORTIONAL COUNTING; X-RAY ID PARTICLE AB This paper describes the construction and calibration of the NIST large area x-ray counting system. Pu-238 sources 8 in (20.32 cm) by 5 in (12.70 cm) thick, emitting L x rays in the range of 12-20 keV are calibrated for total emission rate and also for rate through a centrally located 3 in (7.63 cm) diameter aperture. Alpha particle emission rates are obtained using the known x-ray to alpha particle abundances. The sources will be used to calibrate alpha-particle surface monitors. RP HUTCHINSON, JMR (reprint author), NATL INST STAND & TECHNOL, DIV IONIZING RADIAT, RADIOACT GRP, GAITHERSBURG, MD 20899 USA. NR 4 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 NOV-DEC PY 1991 VL 96 IS 6 BP 693 EP 702 DI 10.6028/jres.096.045 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300003 PM 28184142 ER PT J AU GOODRICH, LF SRIVASTAVA, AN STAUFFER, TC AF GOODRICH, LF SRIVASTAVA, AN STAUFFER, TC TI SIMULATORS OF SUPERCONDUCTOR CRITICAL CURRENT - DESIGN, CHARACTERISTICS, AND APPLICATIONS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CRITICAL CURRENT; DATA ACQUISITION; DATA ANALYSIS; ELECTRONIC CIRCUIT; HIGH-T(C); LOW-T(C); MEASUREMENT METHOD; STANDARD; SUPERCONDUCTOR; SUPERCONDUCTOR SIMULATOR; VOLTAGE-CURRENT CHARACTERISTIC AB The superconductor simulator is an electronic circuit that emulates the extremely nonlinear voltage-current characteristic (the basis of a critical-current measurement) of a superconductor along with its other major electrical properties. Three different types of simulators have been constructed: the passive, active, and hybrid simulator. The passive simulator has the fewest circuit components and offers the least amount of versatility, while the active and hybrid simulators offer more versatility and consequently have more components. Design, characteristics, and applications of the superconductor simulator along with a summary of features are presented. These simulators are high precision instruments, and are thus useful for establishing the integrity of part of a superconductor measurement system. They are potentially useful for testing the measurement method and data acquisition and analysis routines. The 50 A simulator provides critical-current precision of 0.1% at a 1-mu-V signal. This is significantly higher than the precision of a superconducting standard reference material. The superconductor simulator could significantly benefit superconductor measurement applications that require high-precision quality assurance. C1 UNIV COLORADO, ELECT ENGN, BOULDER, CO 80309 USA. RP GOODRICH, LF (reprint author), NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, SUPERCONDUCTOR & MAGNET MEASUREMENTS GRP, BOULDER, CO 80303 USA. NR 11 TC 2 Z9 2 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1991 VL 96 IS 6 BP 703 EP 724 DI 10.6028/jres.096.046 PG 22 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300004 PM 28184143 ER PT J AU MAGEE, JW AF MAGEE, JW TI MOLAR HEAT-CAPACITY (C(V)) FOR SATURATED AND COMPRESSED LIQUID AND VAPOR NITROGEN FROM 65-K TO 300-K AT PRESSURES TO 35 MPA SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CALORIMETER; HEAT CAPACITY; HIGH PRESSURE; ISOCHORIC; LIQUID; MEASUREMENT; NITROGEN; SATURATION; VAPOR AB Molar heat capacities at constant volume (C(nu)) for nitrogen have been measured with an automated adiabatic calorimeter. The temperatures ranged from 65 to 300 K, while pressures were as high as 35 MPa. Calorimetric data were obtained for a total of 276 state conditions on 14 isochores. Extensive results which were obtained in the saturated liquid region (C(nu)(2) and C(sigma)) demonstrate the internal consistency of the C(nu) (rho,T) data and also show satisfactory agreement with published heat capacity data. The overall uncertainty of the C(nu) values ranges from 2% in the vapor to 0.5% in the liquid. RP MAGEE, JW (reprint author), NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, DIV THERMOPHYS, BOULDER, CO 80303 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 14 TC 29 Z9 29 U1 1 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1991 VL 96 IS 6 BP 725 EP 740 DI 10.6028/jres.096.047 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300005 PM 28184144 ER PT J AU LEVIN, BC PAABO, M SCHILLER, SB AF LEVIN, BC PAABO, M SCHILLER, SB TI A STANDARD REFERENCE MATERIAL FOR CALIBRATION OF THE CUP FURNACE SMOKE TOXICITY METHOD FOR ASSESSING THE ACUTE INHALATION TOXICITY OF COMBUSTION PRODUCTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ABS; ACRYLONITRILE-BUTADIENE-STYRENE; COMBUSTION; COMBUSTION PRODUCTS; CUP FURNACE; INHALATION; SRM; STANDARD REFERENCE MATERIAL; TOXICITY TESTS ID FIRES AB A standard reference material (SRM 1048) has been developed for use with the cup furnace smoke toxicity method. This SRM is to be used to calibrate the apparatus and to enable the user to have confidence that the method is being conducted in a correct manner and that the equipment is functioning properly. The toxicological results from this SRM should not be used to compare with those of other materials (i.e., to determine if the combustion products of a test material are more or less toxic than those from this SRM). SRM 1048 is an acrylonitrile-butadiene-styrene (ABS) and is the same as SRM 1007B which is used for calibrating the flaming mode of the Smoke Density Chamber test method (ASTM E-662 and NFPA 258). For the purposes of calibrating the cup furnace smoke toxicity method, LC50 and N-Gas values plus their respective 95% confidence limits have been determined and certified for two combustion modes (flaming and nonflaming) and two observation periods (for the 30 min exposure only and for the 30 min exposure plus a 14 d post-exposure period). The certified LC50 values plus 95% confidence intervals (in g/m3 ) are 27+/-3 (30 min, flaming); 25+/-3 (30 min + 14 d, flaming); 58+/-15 (30 min, nonflaming); and 53+/-12 (30 min + 14 d, nonflaming). The certified N-Gas values plus 95% confidence intervals are 1.4+/-0.2 (30 min, flaming); 1.5+/-0.2 (30 min + 14 d, flaming); 1.2+/-0.2 (30 min, nonflaming); and 1.4+/-0.2 (30 min + 14 d, nonflaming). It is recommended that this SRM be used with the N-Gas approach to calibrate the cup furnace smoke toxicity method rather than to determine the complete LC50 values. The N-Gas approach has the advantage of providing information on the gases responsible for the lethalities as well as the toxic potency of the smoke. In addition, the N-Gas approach reduces the number of experimental animals, the time necessary to complete the calibration, and the expense. C1 NATL INST STAND & TECHNOL, COMP & APPL MATH LAB, GAITHERSBURG, MD 20899 USA. RP LEVIN, BC (reprint author), NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, DIV FIRE MEASUREMENT & RES, GAITHERSBURG, MD 20899 USA. NR 23 TC 5 Z9 5 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 NOV-DEC PY 1991 VL 96 IS 6 BP 741 EP 755 DI 10.6028/jres.096.048 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300006 PM 28184145 ER PT J AU WU, YC FENG, DM KOCH, WF AF WU, YC FENG, DM KOCH, WF TI INVESTIGATION OF THE INTERACTION OF SODIUM-CHLORIDE AND 2 AMINO SULFONIC-ACIDS, HEPES AND MOPSO, BY EMF-MEASUREMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ACTIVITY COEFFICIENT; AMINO ACID; EMF; HEPES; MOPSO; SALT INTERACTION; SODIUM CHLORIDE AB Ionic interactions in the two systems NaCl-HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) and NaCl-MOPSO (3-(N-Morpholino)-2-hydroxypropancsulfonic acid) have been studied in terms of their mutual influence on the respective activity coefficients of each component. Activity coefficients for each component of the two systems and for corresponding buffers are calculated from emf measurements of solutions containing NaCl, the aminosulfonic acid. and its conjugate base in a NaISE/solution/AgCl-Ag cell at 5, 15, 25, and 37-degrees-C. RP WU, YC (reprint author), NATL INST STAND & TECHNOL, DIV INORGAN ANALYT RES, GAITHERSBURG, MD 20899 USA. NR 7 TC 5 Z9 5 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 NOV-DEC PY 1991 VL 96 IS 6 BP 757 EP 762 DI 10.6028/jres.096.049 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300007 PM 28184146 ER PT J AU NIGHTINGALE, S AF NIGHTINGALE, S TI ISO IEC WORKSHOP ON WORLDWIDE RECOGNITION OF OSI TEST-RESULTS, GAITHERSBURG, MD, MAY 6-8, 1991 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP NIGHTINGALE, S (reprint author), NATL INST STAND & TECHNOL, US GOSIP TESTING PROGRAM, GAITHERSBURG, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1991 VL 96 IS 6 BP 763 EP 765 DI 10.6028/jres.096.050 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300008 PM 28184147 ER PT J AU RADACK, SM AF RADACK, SM TI 6TH INTERNATIONAL-CONFERENCE ON THE APPLICATION OF STANDARDS FOR OPEN SYSTEMS, GAITHERSBURG, MD, OCTOBER 2-4, 1990 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP RADACK, SM (reprint author), NATL INST STAND & TECHNOL, COMP SYST LAB, 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 NOV-DEC PY 1991 VL 96 IS 6 BP 767 EP 769 DI 10.6028/jres.096.051 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY883 UT WOS:A1991HY88300009 PM 28184148 ER PT J AU HODGSON, AT DAISEY, JM GROT, RA AF HODGSON, AT DAISEY, JM GROT, RA TI SOURCES AND SOURCE STRENGTHS OF VOLATILE ORGANIC-COMPOUNDS IN A NEW OFFICE BUILDING SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID EXPOSURE AB This study was conducted at a newly constructed federal office building in Portland, Oregon. The primary objectives were to identity the major sources of volatile organic compounds (VOC) in the building and to measure both long-term (one year) and short-term (several day) variations in concentrations and source strengths. Samples for VOC were collected on four occasions over a period of 14 months starting with the first month of occupancy. During the final sampling period, samples were collected over four days (Friday - Monday). The samples were analyzed for individual compounds and for total VOC (TVOC). The results were expressed as specific source strengths, as well as concentrations, to facilitate comparisons of measurements made under different ventilation conditions. The primary source of VOC in the building was identified as liquid-process photocopiers and plotters which emitted a characteristic mixture of C-10-C-11 isoparaffinic hydrocarbons. The specific source strength of TVOC, which was dominated by the emissions from these office machines, remained relatively constant over the course of the study. Motor vehicles in the below-ground parking garage were implicated as another major source of hydrocarbons in the building. Over the final four-day sampling period, the specific source strength of TVOC varied by about a factor of five, predominantly reflecting occupant use of office machines. C1 NATL INST STAMP & TECHNOL,DIV BLDG ENVIRONMENT,CTR BLDG TECHNOL,GAITHERSBURG,MD 20899. RP HODGSON, AT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV APPL SCI,INDOOR ENVIRONM PROGRAM,BERKELEY,CA 94720, USA. NR 13 TC 29 Z9 29 U1 0 U2 3 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD NOV PY 1991 VL 41 IS 11 BP 1461 EP 1468 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GR444 UT WOS:A1991GR44400009 ER PT J AU ORLANSKI, I KATZFEY, J MENENDEZ, C MARINO, M AF ORLANSKI, I KATZFEY, J MENENDEZ, C MARINO, M TI SIMULATION OF AN EXTRATROPICAL CYCLONE IN THE SOUTHERN-HEMISPHERE - MODEL SENSITIVITY SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SYNOPTIC CLIMATOLOGY; STRATOSPHERE; CYCLOGENESIS; TROPOSPHERE; STATISTICS; STREAMS; WINTER; WAVES; FLUX; FLOW AB A rapidly deepening cyclone that occurred over the South Pacific on 5 September 1987 was investigated in order to assess the possible factors contributing to its development. Cyclogenesis took place when a disturbance in the subtropics merged with a wave in the polar westerlies. Analysis revealed that the evolution of the cyclone system was associated with the interaction of a potential vorticity anomaly from the subpolar region with a subtropical surface disturbance in a manner typical of "Class B" cyclogenesis. As the storm intensified, the subtropical jet merged with the polar jet, producing a strong poleward heat transport characteristic of baroclinic systems. However, the absence of tilt to the frontal zone, together with weak vertical wind shear, was suggestive of a significant barotropic component to the storm. The zonal average of potential vorticity over the storm displayed large regions where the meridional gradients have different signs, indicating that the system could have developed initially by internal instabilities (barotropic and/or baroclinic) without significant external forcings. Sensitivity experiments were conducted to determine the role of surface processes in the development of the storm. It was found that development was insensitive to both surface heat fluxes and the presence of South American topography, with little change in either the circulation or kinetic energy of the storm. Intensification of the storm was substantially affected by surface frictional effects, as indicated by significant increases in the vertically averaged kinetic energy when the surface roughness was reduced. The results suggest a need to reduce the roughness heights not only over sea ice, but over the ocean in areas of strong winds as well. C1 CONSEJO NACL INVEST CIENT & TECN,CIMA,CTR INVEST DINAM MAR & ATMOSFERA,BUENOS AIRES,ARGENTINA. RP ORLANSKI, I (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. RI Katzfey, Jack/K-1231-2012 OI Katzfey, Jack/0000-0002-0604-8860 NR 30 TC 18 Z9 18 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 NOV 1 PY 1991 VL 48 IS 21 BP 2293 EP 2312 DI 10.1175/1520-0469(1991)048<2293:SOAECI>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GW238 UT WOS:A1991GW23800001 ER PT J AU DAVIS, GD MOSHIER, WC LONG, GG BLACK, DR AF DAVIS, GD MOSHIER, WC LONG, GG BLACK, DR TI PASSIVE FILM STRUCTURE OF SUPERSATURATED AL-MO ALLOYS SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CORROSION BEHAVIOR; PITTING CORROSION; ALUMINUM FILMS; EXAFS; MOLYBDENUM; CHEMISTRY; CHARGE AB Reflection-extended x-ray absorption fine-structure spectroscopy has been used to probe the local atomic structure of the passive film of supersaturated Al-Mo alloys polarized in KCl. These alloys (with 7-11 atom percent Mo) exhibit resistance to localized attack with an increase in the pitting potential of approximately 600 mV relative to pure aluminum. Measurements show that the structure of the Al-Mo passive films resembles that of alpha-Al2O3/AlOOH, whereas an oxide film grown on pure Al in tartaric acid, which does not possess enhanced passivity, is more like gamma-Al2O3/AlOOH. Complementary x-ray photo-electron spectroscopy measurements indicate the Al-Mo passive film composition to be near that of AlOOH and the tartaric-acid film to be Al2O3. Because corundum (alpha-Al2O3) and diaspore (alpha-AlOOH), which contain only octahedrally coordinated Al atoms, are very stable and inert while gamma-Al2O3, which contains both octahedral and tetrahedral sites, is reactive, the change in structure of the passive film suggests that improved passivity may be correlated with a reduction in the density of tetrahedrally coordinated atoms. This structural change likely results from the incorporation of oxidized Mo into the passive film; only as this Mo is hydrated with a presumed change in local structure does the alloy pit. C1 MARTIN MARIETTA SPACE SYST,DENVER,CO 80201. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP DAVIS, GD (reprint author), MARTIN MARIETTA CORP LABS,BALTIMORE,MD 21227, USA. NR 30 TC 17 Z9 18 U1 1 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD NOV PY 1991 VL 138 IS 11 BP 3194 EP 3199 DI 10.1149/1.2085392 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GN909 UT WOS:A1991GN90900011 ER PT J AU HYLAND, RW SHAFFER, RL AF HYLAND, RW SHAFFER, RL TI RECOMMENDED PRACTICES FOR THE CALIBRATION AND USE OF CAPACITANCE DIAPHRAGM GAUGES AS TRANSFER STANDARDS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Review AB Capacitance diaphragm gages, which were previously known as capacitance manometers, have become a ubiquitous part of systems used in the vacuum community because of their ease of use, compatibility with most gases, and potential accuracy and resolution. They are used not only as pressure measuring devices, but also as transfer standards against which other pressure instruments are calibrated. There are a variety of precautions that must be considered when using these instruments. The American Vacuum Society is therefore presenting this Recommended Practice as a guide to their proper calibration and use as transfer standards. The document covers suggested plumbing configurations, laboratory practices, calibration methods, and reports. C1 EG&G MOUND APPL TECHNOL,MIAMISBURG,OH 45343. RP HYLAND, RW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 14 Z9 14 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1991 VL 9 IS 6 BP 2843 EP 2864 DI 10.1116/1.577209 PG 22 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GP815 UT WOS:A1991GP81500001 ER PT J AU MISRA, DN AF MISRA, DN TI ADSORPTION OF LOW-MOLECULAR-WEIGHT POLY(ACRYLIC ACID) ON HYDROXYAPATITE - ROLE OF MOLECULAR ASSOCIATION AND APATITE DISSOLUTION SO LANGMUIR LA English DT Letter ID DENTAL POLYMER COMPOSITES; AQUEOUS-SOLUTION; INTERFACIAL PROPERTIES; COUPLING AGENTS; CALCIUM; FLUORAPATITE; FLUORIDE; CHARGE; SALTS; WATER AB Adsorption of low molecular weight poly(acrylic acid) from aqueous solution on hydroxyapatite shows that the isotherm first rises, reaches a maximum, then decreases, and is irreversible. This is qualitatively explained on the basis of the increasing self-association of polymeric molecules with concentration and the inability of associated molecules to adsorb as their hydrogen-bonding capability is used up. As surface effects decrease with the increase in initial concentration of the acid, the Ca to P ratio in solution rises and eventually reaches the experimental ratio in the apatite. The initial part of the isotherm satisfies the Langmuir plot. The ratio of the geometrical area of the molecule to the area derived from the Langmuir plot is about the same as that obtained by DiMarzio on the basis of theoretical considerations. RP MISRA, DN (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899, USA. NR 31 TC 24 Z9 24 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV PY 1991 VL 7 IS 11 BP 2422 EP 2424 DI 10.1021/la00059a003 PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA GQ894 UT WOS:A1991GQ89400003 ER PT J AU CARRICK, HJ FAHNENSTIEL, GL STOERMER, EF WETZEL, RG AF CARRICK, HJ FAHNENSTIEL, GL STOERMER, EF WETZEL, RG TI THE IMPORTANCE OF ZOOPLANKTON-PROTOZOAN TROPHIC COUPLINGS IN LAKE-MICHIGAN SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID ACARTIA-TONSA DANA; PHYTOPLANKTON GROWTH; PLANKTONIC COMMUNITY; ALGAE; FOOD; COPEPOD; RATES; CLADOCERANS; PREDATION; DYNAMICS AB The importance of the zooplankton-protozoan trophic coupling was determined experimentally by measured changes in protozoan growth rates with increasing zooplankton biomass. In five of six experiments conducted in Lake Michigan, a significant inverse relationship between protozoan growth and zooplankton biomass was observed (avg r2 = 70%). Zooplankton clearance rates on protozoan assemblages [range, 1.0-6.2 ml (mu-g dry wt)-1 d-1] were comparable to those previously measured for phytoplankton which suggested that protozoa are important prey for zooplankton. Clearance rates on individual protozoan taxa [0-15.6 ml (mu-g dry wt)-1 d-1] were size-dependent. Rates were greatest for taxa < 20-mu-m in size (mainly nanoflagellates and small ciliates). In contrast to findings for phytoplankton, no evidence emerged for grazer resistance nor growth enhancement by planktonic protozoa in response to grazing. The high flux rates for macrozooplankton on heterotrophic nanoflagellates observed in all experiments (0.2-6.0-mu-g C liter-1 d-1) provided evidence that a large fraction of picoplankton C may be directly transferred to higher trophic levels via a picoplankton-flagellate-zooplankton coupling. C1 NOAA,COOPERAT INST LIMNOL & ECOSYST RES,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. UNIV MICHIGAN,CTR GREAT LAKES & AQUAT SCI,ANN ARBOR,MI 48109. NR 42 TC 123 Z9 125 U1 1 U2 9 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1991 VL 36 IS 7 BP 1335 EP 1345 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HE784 UT WOS:A1991HE78400006 ER PT J AU MURPHY, PP FEELY, RA GAMMON, RH KELLY, KC WATERMAN, LS AF MURPHY, PP FEELY, RA GAMMON, RH KELLY, KC WATERMAN, LS TI AUTUMN AIR SEA DISEQUILIBRIUM OF CO-2 IN THE SOUTH-PACIFIC OCEAN SO MARINE CHEMISTRY LA English DT Article AB Accurate assessment of the role of the South Pacific in the global carbon cycle has been hindered by a paucity of data. In particular, the South Pacific has been suggested as a major sink for CO2 on the basis of measurements made principally in the western basin. The PMEL/NOAA Marine CO2 Program has made basin-wide CO2 measurements over 6 years which now permit estimation of surface CO2 fluxes during the austral autumn. These results suggest that the South Pacific is not a significant sink for atmospheric CO2 during the austral autumn. C1 UNIV WASHINGTON, SEATTLE, WA 98195 USA. NOAA, CLIMATE MONITORING & DIAG LAB, BOULDER, CO 80303 USA. RP MURPHY, PP (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 13 TC 26 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD NOV PY 1991 VL 35 IS 1-4 BP 77 EP 84 DI 10.1016/S0304-4203(09)90009-3 PG 8 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA GZ585 UT WOS:A1991GZ58500007 ER PT J AU SCHLOSSER, P BULLISTER, JL BAYER, R AF SCHLOSSER, P BULLISTER, JL BAYER, R TI STUDIES OF DEEP-WATER FORMATION AND CIRCULATION IN THE WEDDELL SEA USING NATURAL AND ANTHROPOGENIC TRACERS SO MARINE CHEMISTRY LA English DT Article ID ANTARCTIC ICE-SHEET; SOUTHERN-OCEAN; BOTTOM WATER; SEAWATER; ATLANTIC; TRITIUM; MASSES; HELIUM AB The application of natural and anthropogenic trace substances in oceanographic studies of the Weddell Sea is reviewed. The potential of some steady-state and transient tracers (tritium, CFC-11 and CFC-12, O-18 and helium isotopes) for studies of deep water formation and circulation is discussed on the basis of data sets collected mainly on cruises of R/V "Polarstern" to the Weddell Sea during the 1980s. CFC/tritium ratio dating of young water masses is applied to estimate mean age and transit times of water involved in Weddell Sea Bottom Water formation. The history of the CFC-11/tritium ratio through time is derived for Weddell Sea shelf waters. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. UNIV HEIDELBERG, INST UMWELTPHYS, W-6900 HEIDELBERG, GERMANY. RP COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA. RI Schlosser, Peter/C-6416-2012 OI Schlosser, Peter/0000-0002-6514-4203 NR 36 TC 59 Z9 60 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 EI 1872-7581 J9 MAR CHEM JI Mar. Chem. PD NOV PY 1991 VL 35 IS 1-4 BP 97 EP 122 DI 10.1016/S0304-4203(09)90011-1 PG 26 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA GZ585 UT WOS:A1991GZ58500009 ER PT J AU HYBERTSON, BM HANSEN, BN BARKLEY, RM SIEVERS, RE AF HYBERTSON, BM HANSEN, BN BARKLEY, RM SIEVERS, RE TI DEPOSITION OF PALLADIUM FILMS BY A NOVEL SUPERCRITICAL FLUID TRANSPORT-CHEMICAL DEPOSITION PROCESS SO MATERIALS RESEARCH BULLETIN LA English DT Article ID VAPOR-DEPOSITION; PD2SI; SI AB Palladium was pyrolytically deposited by a supercritical fluid transport-chemical deposition method using the metal beta-diketonate complex bis-(2,2,7-trimethyl-3,5-octanedionato)palladium(II). Deposition at a rate of 95 nm/min occurred at a substrate temperature of 740-degrees-C. X-ray diffraction and electron microprobe analyses of the reflective films that were deposited on fused silica substrates showed that they contained polycrystalline palladium. The films were electrically conductive, but conductivity was substantially lower than that for bulk palladium. X-ray diffraction of the films deposited on (100) Si substrates showed that palladium silicide was formed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP HYBERTSON, BM (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. NR 30 TC 27 Z9 28 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD NOV PY 1991 VL 26 IS 11 BP 1127 EP 1133 DI 10.1016/0025-5408(91)90118-6 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA GM871 UT WOS:A1991GM87100003 ER PT J AU SCHIRMER, A MILDNER, DFR AF SCHIRMER, A MILDNER, DFR TI CALCULATION OF THE TRANSMISSION OF NEUTRON BENDERS SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article AB A multislot beam bender has been described and its transmission characteristics and reflectivity losses discussed previously. It is shown here that approximate analytical expressions for determining the reflectivity losses using the mean number of reflections agree well with computer simulation results which track the neutron trajectories directly. These calculations can replace Monte Carlo simulations in future bender designs. C1 FORSCHUNGZENTRUMS JULICH, INST FESTKORPERFORSCH, W-5170 JULICH, GERMANY. NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. RP UNIV HANOVER, INST PHYS CHEM & ELEKTROCHEM, CALLINSTR 3-3A, W-3000 HANNOVER, GERMANY. NR 9 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD NOV PY 1991 VL 2 IS 11 BP 1059 EP 1063 DI 10.1088/0957-0233/2/11/010 PG 5 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GN212 UT WOS:A1991GN21200010 ER PT J AU CROVINI, L JUNG, HJ KEMP, RC LING, SK MANGUM, BW SAKURAI, H AF CROVINI, L JUNG, HJ KEMP, RC LING, SK MANGUM, BW SAKURAI, H TI THE PLATINUM RESISTANCE THERMOMETER RANGE OF THE INTERNATIONAL TEMPERATURE SCALE OF 1990 SO METROLOGIA LA English DT Article ID THERMODYNAMIC TEMPERATURES; T68 AB Within the International Temperature Scale of 1990 (ITS-90) the platinum resistance thermometer (PRT) is used to realize the scale from approximately 13,8 K to 1 235 K. Such a temperature range is wider than the corresponding range in the International Practical Temperature Scale of 1968 (IPTS-68) because the PRT is used up to the freezing point of silver (1 234,93 K). In this way, the ITS-90 can be realized with much more precision than the IPTS-68, particularly between 901 K and 1 235 K where the standard Pt-10 % Rh vs Pt thermocouple was previously used. This paper describes some important steps in the construction of the PRT reference function and the criteria for the selection of the PRT interpolating equations of the ITS-90. In contrast to previous international scales, the PRT range of the ITS-90 is based on two reference functions, one from 13,8 K to 273,16 K and the other from 273,15 K to 1234,93 K. The two reference functions were obtained from two real PRTs. A set of interpolating equations is used to account for the differences of other real PRTs from those on which the reference functions are based. They provide flexibility of calibration and high precision as expressed, for instance, by non-uniqueness and sub-range inconsistency not exceeding 0,5 mK over the range from 13,8 K to 693 K. Such good properties are the consequence of the choice of suitable forms for the interpolating equations and of the fine adjustments in the values assigned to some defining fixed points. C1 IST METROL G COLONNETTI,TURIN 73,ITALY. PHYS TECH BUNDESANSTALT,W-1000 BERLIN 10,GERMANY. CSIRO,DIV APPL PHYS,LINDFIELD,NSW 2070,AUSTRALIA. NATL INST METEROL,STATE BUR METROL,BEIJING,PEOPLES R CHINA. NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. NATL RES LAB METEROL,TSUKUBA,IBARAKI 305,JAPAN. NR 23 TC 14 Z9 14 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 PD NOV PY 1991 VL 28 IS 4 BP 317 EP 325 DI 10.1088/0026-1394/28/4/003 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB185 UT WOS:A1991JB18500003 ER PT J AU MOLINAR, GF BEAN, VE HOUCK, J WELCH, B AF MOLINAR, GF BEAN, VE HOUCK, J WELCH, B TI PRESSURE MEASUREMENTS WITH THE MERCURY MELTING LINE REFERRED TO ITS-90 SO METROLOGIA LA English DT Note C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. NR 7 TC 5 Z9 5 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 PD NOV PY 1991 VL 28 IS 4 BP 353 EP 354 DI 10.1088/0026-1394/28/4/008 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB185 UT WOS:A1991JB18500008 ER PT J AU JORGENSEN, DP LEMONE, MA AF JORGENSEN, DP LEMONE, MA TI TAIWAN AREA SO MONTHLY WEATHER REVIEW LA English DT Editorial Material C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP JORGENSEN, DP (reprint author), NOAA,NATL SEVERE STORMS LAB,DIV MESOSCALE RES,MAIL CODE R-E-NSI,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1991 VL 119 IS 11 BP 2517 EP 2517 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GQ910 UT WOS:A1991GQ91000001 ER PT J AU JORGENSEN, DP LEMONE, MA JOU, BJD AF JORGENSEN, DP LEMONE, MA JOU, BJD TI PRECIPITATION AND KINEMATIC STRUCTURE OF AN OCEANIC MESOSCALE CONVECTIVE SYSTEM .1. CONVECTIVE LINE STRUCTURE SO MONTHLY WEATHER REVIEW LA English DT Article ID DOPPLER RADAR OBSERVATIONS; VERTICAL VELOCITY EVENTS; WET-BULB TEMPERATURES; INNER CORE STRUCTURE; CLOUD-BASE UPDRAFT; SQUALL-LINE; IN-CLOUD; THERMODYNAMIC STRUCTURE; METEOROLOGICAL RADAR; INTENSE HURRICANES AB The precipitation, thermodynamic, and kinematic structure of an oceanic mesoscale convective system is studied using airborne Doppler and in situ (flight-level) data collected by the NOAA P-3 aircraft. The system, a well-organized, stationary, north-south convective line, was located near the east coast of Taiwan. In Part I, the basic structure of the line is documented with both datasets, a procedure revealing the strengths and weakness of both approaches. The Doppler data reveal that the warm, moist air feeding the line enters from the east side. Most updrafts associated with the leading edge of the convective line tilt westward below 5 km and then eastward above 5 km. This change of tilt corresponds to a change in the sign of the vertical flux of east-west momentum. To the east of the leading edge, a 10-km-wide zone of strong mesoscale descent is seen. The band is not a complete barrier to the low-level southeasterly flow, and at times and places along the line the inflowing air can move through the band with little or no upward acceleration. The minimum pressures at low levels lie east of the highest reflectivity and also underneath the tilted updraft at upper levels, in agreement with the tilt of the updraft, the buoyancy distribution, and the interaction of the updraft with the vertical shear of the horizontal wind. The Doppler data show very few convective-scale downdrafts and no low-level gust front that would organize the convection as in propagating squall lines, although lack of resolution in the pseudo-dual-Doppler data at the lowest levels may mask features with horizontal scales < 5 km. Vertical incidence Doppler observations show only a few relatively weak convective-scale downdrafts within the heavy rainfall region of the convective line. The in situ data confirm that warm, moist air feeds the convective line from the east side, but they show a larger fraction of air coming into the convection from the boundary layer than do the Doppler data. They confirm that the line is not an effective barrier to the flow: some air from the east of the line, including boundary-layer air, passes through the line without joining the updrafts. Again, some weak convective-scale downdrafts are evident, but a gust front was not detected. However, at low levels, a pool of low-theta-e air lies 10-20 km to the west of the line, outside the dual-Doppler domain. This cool air apparently originated to the north (beneath an extensive stratiform area, but preexisting baroclinicity associated with a front may have also contributed to the cool air) and advected southward. Vertically incident Doppler data confirm the upper-level downdraft zone to the east of the updraft. Above 2 km, the pressure and vertical velocity fields are consistent, with low pressure lying beneath the tilting updrafts in both datasets. Below 2 km, the in situ data reveal a mesolow beneath the westward-tilting updraft that was not captured by the Doppler data, apparently because of contamination of the very lowest levels by ground clutter. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. NATL TAIWAN UNIV, DEPT ATMOSPHER SCI, TAIPEI, TAIWAN. RP NOAA, NATL SEVERE STORMS LAB, DIV MESOSCALE RES, MAIL CODE R-E-NS1, BOULDER, CO 80303 USA. NR 50 TC 41 Z9 41 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1991 VL 119 IS 11 BP 2608 EP 2637 DI 10.1175/1520-0493(1991)119<2608:PAKSOA>2.0.CO;2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GQ910 UT WOS:A1991GQ91000006 ER PT J AU LEMONE, MA JORGENSEN, DP AF LEMONE, MA JORGENSEN, DP TI PRECIPITATION AND KINEMATIC STRUCTURE OF AN OCEANIC MESOSCALE CONVECTIVE SYSTEM .2. MOMENTUM TRANSPORT AND GENERATION SO MONTHLY WEATHER REVIEW LA English DT Article ID SQUALL-LINE; SHEAR; CUMULONIMBUS; EVOLUTION; MOTION; REGION AB This is the second paper of a two-part series documenting the structure of and momentum transport by a subtropical mesoscale convective system near Taiwan, using Doppler radar data and in situ data from the NOAA P-3. Part I defines the basic system structure and evolution. In Part II, the momentum transport by the system is estimated and related to system structure, and the momentum budget for a portion of the embedded convective band is evaluated. Profiles of the vertical flux of horizontal momentum are constructed from in situ data, Doppler radar data, and both combined, in a coordinate system with u normal to the line and positive eastward, since the low-level air is feeding the line from the east. Differences in the fluxes from the two sources appear to be mainly due to an underestimation of the mean vertical velocity from the Doppler radar data. The discrepancy results partially from the concentration of convergence in the boundary layer-precisely where the Doppler cannot adequately sample the convergence-and partially from Doppler problems above 5 km. However, the momentum-flux profile generated from both data sources has features consistent with the structure of the line: rhoBAR uwBAR is negative at lower levels, consistent with the westward tilt of most updrafts at those levels, and positive at upper levels, consistent with the updrafts' eastward tilt. This positive flux is countergradient and not consistent with previous observations, but is suggested in numerical simulations of systems in an environment similar to that for this system, with relatively low convective available potential energy (CAPE), high relative humidity aloft, and positive u shear through the depth of the system. The simulated systems have relatively weak updrafts and gust fronts, also matching this case. The flux rhoBAR upsilon-wBAR is downgradient above approximately 5 km and countergradient below, but is consistent with the average positive vertical velocity carrying southerlies (VBAR > 0) upward. The momentum budget reveals some behavior that differs from that of earlier systems such as that studied by Lafore et al. For example, above 7 km the momentum transport and pressure gradient reinforce to produce substantial acceleration of air exiting the band at high levels toward the front (east), although the vertical transport contributes only a small amount to the observed acceleration. The u positive acceleration at higher levels, being larger than the Doppler estimates of dUBAR/dt at lower levels, increases the overall u shear within the convective band. Estimation of the vertical momentum-flux divergence and pressure-gradient term at low levels from the in situ data supports this result. In previously observed tropical systems, u shear was increased by convective bands only when the u shear was negative. At midlevels, the vertical transport of line-parallel wind (upsilon) by the line acts to increase and slightly elevate the southerly jet maximum in the environmental wind profile usually seen in this region. As in previously documented systems, dVBAR/dz decreases with time within the band. C1 NOAA,NATL SEVERE STORM LAB,DIV MESOSCALE RES,BOULDER,CO 80303. RP LEMONE, MA (reprint author), NATL CTR ATMOSPHER RES,BOULDER,CO 80307, USA. NR 27 TC 26 Z9 28 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1991 VL 119 IS 11 BP 2638 EP 2653 DI 10.1175/1520-0493(1991)119<2638:PAKSOA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GQ910 UT WOS:A1991GQ91000007 ER PT J AU VANWELL, AA DEHAAN, VO MILDNER, DFR AF VANWELL, AA DEHAAN, VO MILDNER, DFR TI THE AVERAGE NUMBER OF REFLECTIONS IN A CURVED NEUTRON GUIDE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Analytic expressions are given for the average number of both garland and zigzag reflections for trajectories through a curved guide as a function of wavelength. Expressions are obtained for cases when the concave surface and the convex surface of the guide have the same and different coatings. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL,GAITHERSBURG,MD 20899. RP VANWELL, AA (reprint author), DELFT UNIV TECHNOL,INST INTERFAC REACTOR,MEKELWEG 15,2629 JB DELFT,NETHERLANDS. NR 4 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1991 VL 309 IS 1-2 BP 284 EP 286 DI 10.1016/0168-9002(91)90113-5 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GN654 UT WOS:A1991GN65400030 ER PT J AU TURCHINSKAYA, MJ ROYTBURD, AL BENNETT, LH SWARTZENDRUBER, LJ SAWANO, K AF TURCHINSKAYA, MJ ROYTBURD, AL BENNETT, LH SWARTZENDRUBER, LJ SAWANO, K TI DETERMINATION OF THERMOACTIVATION PARAMETERS OF VORTEX MOBILITY IN YBA2CU3O7 USING ONLY MAGNETIC MEASUREMENTS SO PHYSICA C LA English DT Article ID HIGH-TC SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; BA-CU-O; ACTIVATED FLUX MOTION; GLASS SUPERCONDUCTIVITY; CREEP AB A method for obtaining the basic parameters of vortex mobility from the measurement of magnetic induction versus time at constant temperature and magnetic field is presented. Two stages of magnetization decay are delineated: (1) the log-time creep from which an activation moment alpha is determined and (2) a slower decay at long times, which provides the activation energy, U. These two stages were both observed for a sample of YBa2Cu3O7 prepared by the quench-melt-growth (QMG) process. Vortex mobility parameters are estimated for this sample using both the classical thermoactivation depinning theory and the vortex glass-state theory. These theories and the parameters obtained from them are discussed and compared. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. NIPPON STEEL CORP LTD,KAWASAKI 211,JAPAN. RP TURCHINSKAYA, MJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 39 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 1991 VL 182 IS 4-6 BP 297 EP 306 DI 10.1016/0921-4534(91)90526-5 PG 10 WC Physics, Applied SC Physics GA GR638 UT WOS:A1991GR63800014 ER PT J AU JIMENEZMIER, J CALDWELL, CD FLEMMING, MG EDERER, DL AF JIMENEZMIER, J CALDWELL, CD FLEMMING, MG EDERER, DL TI ALIGNMENT OF PHOTOIONIZATION-PRODUCED HE+(2P) BETWEEN THE N = 2 AND LEVELS SO PHYSICAL REVIEW A LA English DT Article ID PARTIAL CROSS-SECTIONS; FINAL-STATE SYMMETRY; PHOTO-IONIZATION; ANGULAR-DISTRIBUTION; RESONANCE STRUCTURE; N=2 THRESHOLD; HELIUM; PHOTOIONISATION; EXCITATION; HE+(N=2) AB A determination of the alignment of He+(2p) between the n = 2 and 3 levels was carried out by measuring the angular distribution of the 304-angstrom fluorescence that follows photoionization with synchrotron radiation. The alignment A(c)0 is related to the cross-section ratio zeta = sigma-2pkd/sigma-2p and thus provides a means of separating the kd and ks partial-wave contributions to the 2p ion production. The partial-cross-section ratio R = sigma-2p/sigma-2s was also determined by measuring the fluorescence signal at the magic angle with and without an external electric field that quenches the 2s ions. With these data a partition of the n = 2 cross section into the partial cross sections sigma-2skp, sigma-2pks, and sigma-2pkd was carried out. The effect of the broad 1(3) autoionizing resonance in these partial cross sections was determined. A comparison with the results of a many-body-perturbation-theory calculation shows good agreement for the alignment, as well as for R, sigma-2skp, and sigma-2pks, but somewhat of a discrepancy for sigma-2pkd. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NATL AUTONOMOUS UNIV MEXICO,INST CIENCIAS NUCL,MEXICO CITY 04510,DF,MEXICO. RP JIMENEZMIER, J (reprint author), UNIV CENT FLORIDA,DEPT PHYS,ORLANDO,FL 32816, USA. RI Jimenez-Mier, Jose/A-5081-2009 OI Jimenez-Mier, Jose/0000-0002-5939-9568 NR 43 TC 9 Z9 9 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 NOV 1 PY 1991 VL 44 IS 9 BP 5615 EP 5623 DI 10.1103/PhysRevA.44.5615 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800033 ER PT J AU VEMURI, G AGARWAL, GS ROY, R ANDERSON, MH COOPER, J SMITH, SJ AF VEMURI, G AGARWAL, GS ROY, R ANDERSON, MH COOPER, J SMITH, SJ TI 4-WAVE-MIXING WITH TIME-DELAYED CORRELATED FIELDS OF ARBITRARY BANDWIDTHS AND PUMP INTENSITIES SO PHYSICAL REVIEW A LA English DT Article ID OPTICAL COHERENT TRANSIENTS; INCOHERENT-LIGHT; FLUCTUATING PULSES; CHAOTIC FIELDS; SPECTROSCOPY; REGIME; NOISE AB We consider the generation of four-wave-mixing signals by an ensemble of two-level atoms interacting with broadband, correlated, pump and probe fields in the forward geometry. We show how the calculation of the four-wave-mixing signal reduces to the solution of six coupled Langevin equations that are numerically integrated using Monte Carlo methods. We account for the pump-induced saturation effects although the probe is weak. The finite correlation time of the pump and probe fields is also included. For weak and delta-correlated pump fields, we reproduce the results of Morita and Yajima [Phys. Rev. A 30, 2525 (1984)]. We find that even for short correlation times of the fields, the four-wave-mixing signal, as a function of the delay between the pump and the probe fields, starts reviving with increase in the pump intensity. This revival as a function of the pump-probe delay time becomes more pronounced with further increase in the pump intensity. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV HYDERABAD,SCH PHYS,HYDERABAD 500134,ANDHRA PRADESH,INDIA. GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. RP VEMURI, G (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 25 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP 6009 EP 6017 DI 10.1103/PhysRevA.44.6009 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800076 ER PT J AU GIBBLE, KE COOPER, J AF GIBBLE, KE COOPER, J TI INTERATOMIC POTENTIALS FROM VELOCITY-CHANGING COLLISION KERNELS SO PHYSICAL REVIEW A LA English DT Note ID SPECTROSCOPY AB Measurements of velocity-changing collision kernels have recently been reported. Here we describe the results of calculations which demonstrate that interatomic potentials can accurately be derived from such data. It is important to analyze the kernel directly in terms of an interatomic potential and not in terms of a traditional energy-averaged differential cross section. We use experimental results to determine the Rb-He potential and compare it to calculated potentials. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 10 TC 9 Z9 9 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV 1 PY 1991 VL 44 IS 9 BP R5335 EP R5338 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GP388 UT WOS:A1991GP38800002 ER PT J AU PATRICK, H WIEMAN, CE AF PATRICK, H WIEMAN, CE TI FREQUENCY STABILIZATION OF A DIODE-LASER USING SIMULTANEOUS OPTICAL FEEDBACK FROM A DIFFRACTION GRATING AND A NARROW-BAND FABRY-PEROT CAVITY SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We present a system which uses optical feedback from a diffraction grating to provide primary control over the frequency tuning of a diode laser, and employs simultaneous optical feedback from a narrowband Fabry-Perot cavity to reduce the linewidth. The frequencies of the optical feedback from the diffraction grating and narrowband cavity are electronically locked using a novel technique. The reduction in the linewidth is measured as a reduction in the frequency noise seen on the side of a Cs-saturated absorption line. The presence of optical feedback from the narrowband cavity reduces the frequency noise by a factor of 3 compared to the frequency noise obtained using the grating feedback alone. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP PATRICK, H (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 6 TC 27 Z9 27 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1991 VL 62 IS 11 BP 2593 EP 2595 DI 10.1063/1.1142236 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300012 ER PT J AU ANDERSON, MH JONES, RD COOPER, J SMITH, SJ AF ANDERSON, MH JONES, RD COOPER, J SMITH, SJ TI ERRORS IN THE MEASUREMENT OF NON-GAUSSIAN NOISE SPECTRA USING RF SPECTRUM ANALYZERS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LIGHT; TIME AB We discuss the nature of errors which may occur when the spectra of random signals not obeying Gaussian statistics are measured with typical rf spectrum analyzers. These errors depend on both the noise statistics and the process used to detect the random signal after it has been passed through a narrow bandpass filter within the spectrum analyzer. In general, for random signals not obeying Gaussian statistics, the output of the bandpass filter must be measured with a square law detector if the resulting measurement is to be strictly proportional to the power spectrum of the input signal. We compare measurements of the power spectra of non-Gaussian noise using a commercial spectrum analyzer with its resident envelope detector, with measurements by the same analyzer fitted with a square law detector. Differences of about 5% were observed. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP ANDERSON, MH (reprint author), JOINT INST COLORADO,BOULDER,CO 80309, USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1991 VL 62 IS 11 BP 2828 EP 2830 DI 10.1063/1.1142168 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GN773 UT WOS:A1991GN77300049 ER PT J AU GOLDEN, JH SNOW, JT AF GOLDEN, JH SNOW, JT TI MITIGATION AGAINST EXTREME WINDSTORMS SO REVIEWS OF GEOPHYSICS LA English DT Review ID UNITED-STATES; DOPPLER RADAR; TORNADOES; CLIMATOLOGY; HURRICANES; VORTICES; SYSTEM; VORTEX AB This paper treats various manifestations of atmospheric wind in relation to the effects these have on human safety and comfort. We concentrate on more recent advances in our knowledge of the geophysical structure and behavior of extreme windstorms. Particular attention is given to severe thunderstorms and their attendant mesoscale offspring, tornadoes and downbursts, as well as the extratropical and tropical cyclones. It appears that the highest credible wind speed estimates in any of these windstorms so far are for tornadoes, about 135 m s-1; these have been derived from photogrammetric analyses of eyewitness photography and remote sensing from in situ and portable Doppler radars. On the other hand, it is found from extensive aerial and ground poststorm damage surveys that the vast majority of all tornadoes have peak wind speeds no higher than those measured by sparse surface networks and reconnaissance aircraft in mature hurricanes. New in situ and remote sensing (Doppler radars) weather observing networks currently being deployed across the United States and other countries, combined with greater public awareness, may significantly alter our current assessment of the climatology of extreme windstorms in these areas. Advances in the field of wind engineering are shown to afford cost-effective techniques for mitigating against extreme windstorms, including tornadoes. However, the rather unique sociopolitical framework of building codes and practices in the United States presently hinders effective technology transfer and mitigation practice. Important implications of these findings accrue to forecasts and warnings of forest fires and airborne dispersal (loss of containment) of toxic materials, including nuclear processing by-products. C1 PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. RP GOLDEN, JH (reprint author), NOAA,1825 CONNECTICUT AVE NW,ROOM 517,WASHINGTON,DC 20235, USA. NR 90 TC 20 Z9 20 U1 3 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD NOV PY 1991 VL 29 IS 4 BP 477 EP 504 DI 10.1029/91RG01814 PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GR588 UT WOS:A1991GR58800001 ER PT J AU JACKSON, CL MCKENNA, GB AF JACKSON, CL MCKENNA, GB TI ON THE ANOMALOUS FREEZING AND MELTING OF SOLVENT CRYSTALS IN SWOLLEN GELS OF NATURAL-RUBBER SO RUBBER CHEMISTRY AND TECHNOLOGY LA English DT Article ID CRYSTALLIZATION; TEMPERATURE; WATER; POINT C1 NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. RI McKenna, Gregory/O-1134-2013; OI McKenna, Gregory/0000-0002-5676-9930; Jackson, Catheryn/0000-0003-1611-3926 NR 30 TC 28 Z9 28 U1 0 U2 1 PU AMER CHEMICAL SOC INC PI AKRON PA RUBBER DIV UNIV AKRON PO BOX 499, AKRON, OH 44309-0499 USA SN 0035-9475 EI 1943-4804 J9 RUBBER CHEM TECHNOL JI Rubber Chem. Technol. PD NOV-DEC PY 1991 VL 64 IS 5 BP 760 EP 768 DI 10.5254/1.3538588 PG 9 WC Polymer Science SC Polymer Science GA HR133 UT WOS:A1991HR13300007 ER PT J AU POSTEK, MT KEERY, WJ AF POSTEK, MT KEERY, WJ TI CRYOPUMP VIBRATION ISOLATION SYSTEM FOR AN SEM SO SCANNING LA English DT Article ID CONTAMINATION AB A standard commercially available cryopump system has been installed on a scanning electron microscope (SEM) using specially optimized vacuum vibration isolation bellows. This installation was successful in reducing the cryopump-induced vibration to a level that did not degrade the standard performance or resolution of the SEM in the pump-on mode and, in the pump-off (or coasting) mode, eliminated all measurable instrument-induced vibration (i.e., from the vacuum system). This article outlines the manner in which this performance has been accomplished and presents the results of an experiment demonstrating the reduction of specimen contamination provided by this type of vacuum system. RP POSTEK, MT (reprint author), NATL INST STAND & TECHNOL,MICROELECTR DIMENS METROL,TECHNOL BLDG A-347,GAITHERSBURG,MD 20899, USA. NR 18 TC 4 Z9 4 U1 1 U2 3 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD NOV-DEC PY 1991 VL 13 IS 6 BP 404 EP 409 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA GY258 UT WOS:A1991GY25800003 ER PT J AU OVERPECK, JT BARTLEIN, PJ WEBB, T AF OVERPECK, JT BARTLEIN, PJ WEBB, T TI POTENTIAL MAGNITUDE OF FUTURE VEGETATION CHANGE IN EASTERN NORTH-AMERICA - COMPARISONS WITH THE PAST SO SCIENCE LA English DT Article ID CO2-INDUCED CLIMATE CHANGE; CARBON-DIOXIDE; FORESTS; MODEL; SIMULATIONS; EUROPE AB Increases in atmospheric trace gas concentrations could warm the global average temperature 1.5-degrees to 4.5-degrees-C by the end of the next century. Application of climate-pollen response surfaces to three climate model simulations of doubled preindustrial atmospheric CO2 levels shows that the change in the equilibrium distribution of natural vegetation over eastern North America over the next 200 to 500 years could be larger than the overall change during the past 7,000 to 10,000 years and equivalent to the change that took place over the 1,000- to 3,000-year period of most rapid deglaciation. Some plant ranges and abundance maxima could shift as much as 500 to 1000 km during the next 200 to 500 years; such changes would have dramatic impacts on silvicultural and natural ecosystems. Although unprecedented vegetation change is likely if climate changes as predicted, forecasting the exact timing and patterns of change will be difficult. C1 COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964. UNIV OREGON,DEPT GEOG,EUGENE,OR 97403. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. RP OVERPECK, JT (reprint author), NOAA,NATL GEOPHYS DATA CTR,PALEOCLIMATOL PROGRAM,325 BROADWAY,BOULDER,CO 80303, USA. RI Bartlein, Patrick/E-4643-2011 OI Bartlein, Patrick/0000-0001-7657-5685 NR 41 TC 149 Z9 153 U1 0 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 1 PY 1991 VL 254 IS 5032 BP 692 EP 695 DI 10.1126/science.254.5032.692 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GN474 UT WOS:A1991GN47400035 PM 17774796 ER PT J AU CULHANE, JL HIEI, E DOSCHEK, GA CRUISE, AM OGAWARA, Y UCHIDA, Y BENTLEY, RD BROWN, CM LANG, J WATANABE, T BOWLES, JA DESLATTES, RD FELDMAN, U FLUDRA, A GUTTRIDGE, P HENINS, A LAPINGTON, J MAGRAW, J MARISKA, JT PAYNE, J PHILLIPS, KJH SHEATHER, P SLATER, K TANAKA, K TOWNDROW, E TROW, MW YAMAGUCHI, A AF CULHANE, JL HIEI, E DOSCHEK, GA CRUISE, AM OGAWARA, Y UCHIDA, Y BENTLEY, RD BROWN, CM LANG, J WATANABE, T BOWLES, JA DESLATTES, RD FELDMAN, U FLUDRA, A GUTTRIDGE, P HENINS, A LAPINGTON, J MAGRAW, J MARISKA, JT PAYNE, J PHILLIPS, KJH SHEATHER, P SLATER, K TANAKA, K TOWNDROW, E TROW, MW YAMAGUCHI, A TI THE BRAGG CRYSTAL SPECTROMETER FOR SOLAR-A SO SOLAR PHYSICS LA English DT Article ID X-RAY-SPECTRA; HINOTORI SATELLITE; FLARES AB The Bragg Crystal Spectrometer (BCS) is one of the instruments which makes up the scientific payload of the SOLAR-A mission. The spectrometer employs four bent germanium crystals, views the whole Sun and observes the resonance line complexes of H-like Fe XXVI and He-like XXV, Ca XIX, and S XV in four narrow wavelength ranges with a resolving Power (lambda/DELTA-lambda) of between 3000 and 6000. The spectrometer has approaching ten times better sensitivity than that of previous instruments thus permitting a time resolution of better than 1 s to be achieved. The principal aim is the measurement of the properties of the 10 to 50 million K plasma created in solar flares with special emphasis on the heating and dynamics of the plasma during the impulsive phase. This paper summarizes the scientific objectives of the BCS and describes the design, characteristics, and performance of the spectrometers. C1 NATL ASTRON OBSERV JAPAN, TOKYO, JAPAN. USN, RES LAB, WASHINGTON, DC 20375 USA. RUTHERFORD APPLETON LAB, ABINGDON, ENGLAND. INST SPACE & ASTRONAUT SCI, TOKYO 153, JAPAN. UNIV TOKYO, TOKYO 113, JAPAN. NATL INST STAND & TECHNOL, WASHINGTON, DC USA. RP CULHANE, JL (reprint author), UCL, MULLARD SPACE SCI LAB, HOLMBURY, ENGLAND. RI Lapington, Jon/A-7669-2012 NR 18 TC 184 Z9 185 U1 1 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 1991 VL 136 IS 1 BP 89 EP 104 DI 10.1007/BF00151696 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GU809 UT WOS:A1991GU80900006 ER PT J AU BENZ, SP BURROUGHS, CJ AF BENZ, SP BURROUGHS, CJ TI 2-DIMENSIONAL ARRAYS OF JOSEPHSON-JUNCTIONS AS VOLTAGE-TUNABLE OSCILLATORS SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID PHASE-LOCKING AB We have detected coherent emission from two-dimensional (2D) arrays of superconductor-insulator-superconductor (sis) Josephson junctions. 2D arrays emit coherent radiation over a frequency range of 60 to 210 GHz, when coupled to detector junctions through Dc-blocking capacitors, The detector junctions exhibit Shapiro steps at frequencies corresponding to the voltage across single-array junctions. The maximum power from a 10-by-10 junction array coupled to a detector junction occurs at 150 GHz and is estimated to be 0.4-mu-W, based on simulations of the detector circuit. By varying the number of array junctions, the array geometry, the junction critical current, and the coupling circuit, we have begun determining the essential conditions for observing coherent emission. RP BENZ, SP (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 16 TC 42 Z9 42 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1991 VL 4 IS 11 BP 561 EP 567 DI 10.1088/0953-2048/4/11/002 PG 7 WC Physics, Applied; Physics, Condensed Matter SC Physics GA HA193 UT WOS:A1991HA19300003 ER PT J AU CAVICCHI, R SEMANCIK, S AF CAVICCHI, R SEMANCIK, S TI REACTIVITY OF PD AND SN ADSORBATES ON PLASMA AND THERMALLY OXIDIZED SNO2(110) SO SURFACE SCIENCE LA English DT Article ID OXYGEN; SURFACES; CLUSTERS; STATES; OXIDES AB The surface accumulation layer that forms as a result of oxygen vacancies near the surface of an oxide semiconductor can be used as an extremely sensitive probe of phenomena occurring at the surface. By incorporating a UHV-compatible, four-point conductance measurement in our surface analysis apparatus, we have investigated the formation of metal-semiconductor interfaces on SnO2(110) with varying oxygen stoichiometry. For only a 0.1 monolayer equivalent (ML) coverage of Sn deposited onto a high-oxygen-content surface prepared by oxygen plasma treatment, we observe a 500-fold increase in conductance. Our results suggest that at this coverage, Sn reacts with the excess chemisorbed oxygen and also creates point defects by abstracting oxygen from the lattice. In contrast, Pd reacts only with chemisorbed species, as indicated by a smaller conductance change and by differences in the size-effect shifted core levels observed at the same coverage for thermal and plasma oxidized surfaces. Oxygen plasma treatment of an 8 ML Pd film is shown to be an effective room temperature oxidation procedure and is used as a basis of comparison for studies of the reaction of submonolayer coverages of Pd on plasma and thermally oxidized surfaces. The coverage dependence of the surface conductance for Pd on thermal and plasma oxidized surfaces exhibits a peak near 1 ML, possibly indicating the onset of Schottky barrier formation: barriers underneath the metal islands deplete the surface of carriers; or the formation of scattering centers. At higher coverage, inter-island conductance dominates and the conductance rises. Surfaces prepared with decreasing oxygen content (thermal, vacuum annealed, ion-sputtered) show increased apparent alloying of Pd to surface Sn. RP CAVICCHI, R (reprint author), NATL INST STAND & TECHNOL,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899, USA. NR 13 TC 16 Z9 16 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV PY 1991 VL 257 IS 1-3 BP 70 EP 78 DI 10.1016/0039-6028(91)90780-V PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GP212 UT WOS:A1991GP21200017 ER PT J AU CAMPTON, DE ALLENDORF, FW BEHNKE, RJ UTTER, FM CHILCOTE, MW LEIDER, SA LOCH, JJ AF CAMPTON, DE ALLENDORF, FW BEHNKE, RJ UTTER, FM CHILCOTE, MW LEIDER, SA LOCH, JJ TI REPRODUCTIVE SUCCESS OF HATCHERY AND WILD STEELHEAD SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID TROUT SALMO-GAIRDNERI; CUTTHROAT TROUT; RAINBOW-TROUT; SYMPATRIC POPULATIONS; GENETIC-VARIABILITY; ATLANTIC SALMON; CLARKI-CLARKI; BROWN TROUT; WASHINGTON; SUMMER C1 WASHINGTON DEPT WILDLIFE,OLYMPIA,WA 98501. OREGON DEPT FISH & WILDLIFE,PORTLAND,OR 97035. UNIV MONTANA,DIV BIOL SCI,MISSOULA,MT 59812. COLORADO STATE UNIV,DEPT FISH & WILDLIFE BIOL,FT COLLINS,CO 80523. NATL MARINE FISH SERV,SEATTLE,WA 98112. RP CAMPTON, DE (reprint author), UNIV FLORIDA,DEPT FISH & AQUACULTURE,GAINESVILLE,FL 32606, USA. NR 45 TC 26 Z9 26 U1 0 U2 4 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 1991 VL 120 IS 6 BP 816 EP 827 DI 10.1577/1548-8659(1991)120[816:RSOHAW]2.0.CO;2 PG 12 WC Fisheries SC Fisheries GA HE873 UT WOS:A1991HE87300016 ER PT J AU BOND, LJ TAYLOR, J AF BOND, LJ TAYLOR, J TI INTERACTION OF RAYLEIGH-WAVES WITH A RIB ATTACHED TO A PLATE SO ULTRASONICS LA English DT Article DE ACOUSTIC EMISSION; RAYLEIGH WAVES; MODELING ID DISCONTINUITIES; SCATTERING AB An analysis of the interaction of a pulse of Rayleigh waves on a plate with a rectangular flange or rib attached in the far field of its acoustic emission (AE) source is presented. A finite difference ( FD) model is used to give numerical visualizations of the development of the complete wave-field propagating through the structure and also to give displacement data for selected points. An 'energy partition model', for Rayleigh wave propagation across the rib has been developed and is described. Ray theory wave arrival time calculations are given for the propagation of various mode-converted components transmitted across the flange. A series of experimental measurements of AE wave propagation across a T-butt welded rib on a plate were made and these are compared with the model predictions. The practical implications of these findings for acoustic emission monitoring of large structures of complex shape are discussed. C1 UNIV COLORADO,BOULDER,CO 80309. ADMIRALTY RES ESTAB HOLTON HEATH,POOLE BH16 6JU,DORSET,ENGLAND. RP BOND, LJ (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0041-624X J9 ULTRASONICS JI Ultrasonics PD NOV PY 1991 VL 29 IS 6 BP 451 EP 458 DI 10.1016/0041-624X(91)90075-J PG 8 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA GM280 UT WOS:A1991GM28000004 ER PT J AU LEDBETTER, H AF LEDBETTER, H TI ATOMIC FREQUENCY AND ELASTIC-CONSTANTS SO ZEITSCHRIFT FUR METALLKUNDE LA English DT Article AB Since 1910, teachers and researchers have invoked the Einstein-Madelung-Sutherland relationship to relate solid-state atomic-vibration frequencies to other basic solid-state properties: M = atomic mass, V(a) = atomic volume, and B = Bulk modulus. The usual relationship for the frequency is nu = KV(a)1/6 M-1/2 B1/2, where K denotes a material-independent numerical constant. For 24 elements crystallized in a cubic lattice, we show that substituting the shear modulus for the bulk modulus improves the E-M-S relationship from an average 24-percent discrepancy to an average 2-percent discrepancy. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 24 TC 29 Z9 29 U1 0 U2 0 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 860420, W-8163 MUNICH, GERMANY SN 0044-3093 J9 Z METALLKD JI Z. Metallk. PD NOV PY 1991 VL 82 IS 11 BP 820 EP 822 PG 3 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA GV871 UT WOS:A1991GV87100002 ER PT J AU REED, RP SIMON, NJ WALSH, RP AF REED, RP SIMON, NJ WALSH, RP TI CREEP OF COPPER - 4-300-K SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID CRYOGENIC TEMPERATURES AB Creep measurements at 300, 76 and 4 K were conducted on C10400 copper. The specimens were held under a constant tensile load to give ratios of applied stress to yield strength in the range 0.8-2.0. The strain was measured using strain gages (sensitivities of 10(-6)). Creep data were fitted by a non-linear least-squares procedure to a series of expressions that have been widely used to describe primary, transient, and steady-state conditions. No steady-state creep was observed, even at 300 K. Instead, at all temperatures, the time dependence of creep strain is best described as logarithmic. Activation volumes obtained from logarithmic creep analyses, from tensile strain-rate-change and stress relaxation measurements were compared. It was found that the constant alpha in the logarithmic creep expression is linearly dependent on the tensile strain-hardening rate at constant stress. RP REED, RP (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 20 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 30 PY 1991 VL 147 IS 1 BP 23 EP 32 DI 10.1016/0921-5093(91)90801-S PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GQ565 UT WOS:A1991GQ56500003 ER PT J AU YANG, AJM DIMARZIO, EA AF YANG, AJM DIMARZIO, EA TI GLASS TEMPERATURE OF POLYMER RING-SYSTEMS SO MACROMOLECULES LA English DT Article ID TRANSITION AB The glass temperatures of polymer ring systems are predicted from first principles and then compared to four sets of experimental data. In all four cases the glass temperatures rise with decreasing molecular weight as predicted by the theory. The glass transition is assumed to occur when the configurational entropy reaches a critically small value as the temperature is lowered. An attempt is made to keep the large number of parameters to a minimum by (1) estimating the number of flexible bonds per monomer through knowledge of chemical structure, (2) estimating the number of beads per monomer through considerations of volume, (3) estimating the intermolecular (hole) energy by means of the thermal expansion coefficient DELTA-alpha, and (4) fixing the lattice coordination number at the same value (z = 4) for all materials. The stiffness parameter DELTA-epsilon is determined by a fitting to the infinite molecular weight glass temperature. With these constraints the fit to data is only qualitative. Although the theory is compared to experimental data only for glass temperature vs molecular weight, approximate formulas are obtained for ring glass temperature variation with plasticizer and with blend composition when at least one of the two blend components is a ring. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ARMSTRONG WORLD IND INC,LANCASTER,PA 17604. NR 18 TC 21 Z9 21 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 28 PY 1991 VL 24 IS 22 BP 6012 EP 6018 DI 10.1021/ma00022a017 PG 7 WC Polymer Science SC Polymer Science GA GM483 UT WOS:A1991GM48300017 ER PT J AU CORNELL, EA MONROE, C WIEMAN, CE AF CORNELL, EA MONROE, C WIEMAN, CE TI MULTIPLY LOADED, AC MAGNETIC TRAP FOR NEUTRAL ATOMS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HYDROGEN AB We have demonstrated an oscillating-gradient magnetic trap for confining cesium atoms in the lowest-energy spin state. In this state spin-flip collisions are energetically forbidden and thus the primary density- and temperature-limiting process for magnetic traps is eliminated. The atoms are initially collected in a vapor-cell optical trap, then repetitively tossed into a high-vacuum region, focused in three dimensions, and accumulated in the magnetic trap. An optical pumping scheme inserts each new batch of atoms into the magnetic trap without perturbing the atoms already trapped. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP CORNELL, EA (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. RI Monroe, Christopher/G-8105-2011 NR 13 TC 99 Z9 100 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 OCT 28 PY 1991 VL 67 IS 18 BP 2439 EP 2442 DI 10.1103/PhysRevLett.67.2439 PG 4 WC Physics, Multidisciplinary SC Physics GA GL801 UT WOS:A1991GL80100009 ER PT J AU MASUDAJINDO, K TEWARY, VK THOMSON, R AF MASUDAJINDO, K TEWARY, VK THOMSON, R TI THEORETICAL-STUDY OF THE FRACTURE OF BRITTLE MATERIALS - ATOMISTIC CALCULATIONS SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID CRACK TIP DEFORMATION; LATTICE-STATICS; GREEN-FUNCTION; CUBIC METALS; CRYSTALS; SILICON; STATES; DUCTILE AB Using the lattice Green's function approach and linear combination of atomic orbitals (LCAO) electronic theory, we investigate the fracture behavior of brittle materials such as semiconductors and ceramic materials. The cracked-lattice Green's functions are derived by applying the Fourier transform technique and solving the Dyson equation for a three-dimensional simple cubic lattice (cracks with kink pairs) as well as for the diamond cubic lattice. The total energy calculation scheme based on the LCAO electronic theory is used to obtain the nonlinear bond-breaking forces, taking into account the effects of impurity doping and/or environment effects of the external molecules. The calculated crack properties and the related fracture behavior of the brittle materials are discussed in detail. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP MASUDAJINDO, K (reprint author), TOKYO INST TECHNOL,DEPT MAT SCI & ENGN,MIDORI KU,YOKOHAMA,KANAGAWA 227,JAPAN. NR 47 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 25 PY 1991 VL 146 IS 1-2 BP 273 EP 289 DI 10.1016/0921-5093(91)90283-S PG 17 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GP429 UT WOS:A1991GP42900021 ER PT J AU LETTIERI, TR MARX, E SONG, JF VORBURGER, TV AF LETTIERI, TR MARX, E SONG, JF VORBURGER, TV TI LIGHT-SCATTERING FROM GLOSSY COATINGS ON PAPER SO APPLIED OPTICS LA English DT Article DE ANGLE-RESOLVED SCATTERING; COATINGS; LIGHT SCATTERING; PAPER; ROUGHNESS; SURFACE FINISH; SURFACES; TEXTURE ID SURFACE-ROUGHNESS AB The application of angle-resolved light scattering (ARLS) to the measurement of the surface roughness of glossy coatings on paper was investigated. To this end, ARLS patterns were measured for laser light scattered from several glossy paper samples, and these patterns were compared with those calculated using a theoretical model based on plane-wave scattering from an isotropic rough surface. Mechanical stylus profilometry data for the rms roughnesses and the autocorrelation functions of the coatings were used as input to calculate the patterns. For all the paper samples measured, as well as for all the incidence angles used, there was good agreement between the experimental and the calculated patterns when all the rms roughnesses measured by profilometry were reduced by 30%. The indication from these experiments is that ARLS may be used to determine the roughness parameters of the coatings. As a check on these results, measurements were also performed with a commercial optical surface probe; these data agreed well with both the ARLS and the stylus profilometry results. RP LETTIERI, TR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 24 Z9 25 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1991 VL 30 IS 30 BP 4439 EP 4447 PG 9 WC Optics SC Optics GA GQ421 UT WOS:A1991GQ42100029 PM 20717222 ER PT J AU ARDANUY, PE STOWE, LL GRUBER, A WEISS, M AF ARDANUY, PE STOWE, LL GRUBER, A WEISS, M TI SHORTWAVE, LONGWAVE, AND NET CLOUD-RADIATIVE FORCING AS DETERMINED FROM NIMBUS-7 OBSERVATIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BUDGET EXPERIMENT; DATA SET; EARTH; ERB; CLIMATE AB We studied the effect of clouds on the Earth's radiation budget at the top of the atmosphere. Both the northern hemisphere summer and winter are considered in terms of cloud-radiative forcing, which describes the total effect of clouds on the Earth's radiation budget components. The cloud forcing is obtained by using statistically generated models correlating simultaneous observations of cloud properties and radiation budget parameters obtained from observations from Nimbus 7 satellite observations. The models estimate the broadband albedo and longwave flux throughout the range of variation, including periods of extensive to near-total cloud cover where more simplistic representations fail. As such, the models are used to estimate period-averaged clear-sky radiation budget components. Knowledge of the cloudy-sky and clear-sky radiation budget components permits the computation of cloud-radiative forcing. We show that the net effect of clouds is to cool the Earth. On the average, for an Earth observed to be 52.1% cloud covered, the net cloud forcing is -26.8 W m-2. This net cooling is obtained from a longwave warming of 24.1 W m-2 and a shortwave cooling of -50.9 W m-2. Over much of the Earth there is a general compensation between the warming and cooling effects of clouds. However, over the middle- and high-latitude oceans the albedo effect of clouds is dominant. This is particularly true in each summer hemisphere, where the effects of persistent cloudiness, low oceanic albedos, and high solar insolation combine to drive the net cloud forcing strongly negative. The net effect of cloud forcing cools the Earth, primarily due to the effect of clouds in the summer hemisphere oceans. C1 NOAA, NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, WASHINGTON, DC 20233 USA. RP ARDANUY, PE (reprint author), RES & DATA SYST CORP, GREENBELT, MD 20770 USA. NR 26 TC 48 Z9 50 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1991 VL 96 IS D10 BP 18537 EP 18549 DI 10.1029/91JD01992 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GM167 UT WOS:A1991GM16700001 ER PT J AU KASIBHATLA, PS LEVY, H MOXIM, WJ CHAMEIDES, WL AF KASIBHATLA, PS LEVY, H MOXIM, WJ CHAMEIDES, WL TI THE RELATIVE IMPACT OF STRATOSPHERIC PHOTOCHEMICAL PRODUCTION ON TROPOSPHERIC NOY LEVELS - A MODEL STUDY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; NITRIC-ACID; SEASONAL-VARIATION; DRY DEPOSITION; GLOBAL MODEL; NITROGEN; NITRATE; PACIFIC; OZONE; ATMOSPHERE AB The 11-level Geophysical Fluid Dynamics Laboratory (GFDL) global chemical transport model has been used to assess the impact of stratospheric NO(x) production on tropospheric reactive nitrogen (NO(y)) concentrations. A temporally varying source function was constructed using specified two-dimensional, monthly average O3, N2O, temperature, and surface pressure data generated by the GFDL "SKYHI" model. The calculated yearly NO(y) production rate is 0.64 Tg N (0.64 x 10(12) g N). A wet removal scheme, which distinguishes between stable and convective rain based on the bulk Richardson number, is introduced. Simulations have been performed with a simplified chemical mechanism which fractionates NO(y) into soluble and insoluble species. The role of peroxyacetyl nitrate (PAN) in determining the impact of stratospheric injection on the tropospheric NO(y) budget is studied by comparing results of simulations with and without PAN chemistry. We conclude that (1) the stratospheric source is too small to account for background surface NO(y) concentrations observed in the remote (i.e., regions a few thousand kilometers from continental source regions) troposphere. Surface NO(y) mixing ratios seldom exceed 10 parts per trillion by volume (pptv) in the model northern hemisphere and are always below 20 pptv. Together, fossil fuel combustion emissions and stratospheric injection account for less than 10% of observed surface nitrate concentrations in the remote tropical Pacific. (2) The impact of the stratospheric source is comparable to that of the fossil fuel combustion source in terms of NO(y) mixing ratios in the northern hemisphere at the 500 mbar model level and is more important in the middle and high latitudes of the southern hemisphere. At the 315 mbar model level the stratospheric source contribution to NO(y) levels is more important than that of the fossil fuel source at all latitudes, except in the tropics. However, substantial contributions from other NO(y) sources are needed to explain observations in the remote middle and upper troposphere. (3) Inclusion of PAN chemistry has the effect of increasing model-calculated surface NO(y) mixing ratios in the northern hemisphere middle and high latitudes by factors of 1.5-3 during winter/spring and by factors of 2-4 during summer/fall. Surface NO(y) mixing ratios in the southern hemisphere show a smaller increase due to slower rates of PAN formation. This is a direct result of lower hydrocarbon concentrations in the southern hemisphere. C1 PRINCETON UNIV, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08544 USA. RP KASIBHATLA, PS (reprint author), GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. RI Kasibhatla, Prasad/A-2574-2010 NR 45 TC 70 Z9 70 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 OCT 20 PY 1991 VL 96 IS D10 BP 18631 EP 18646 DI 10.1029/91JD01665 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GM167 UT WOS:A1991GM16700008 ER PT J AU PIOTROWICZ, SR BEZDEK, HF HARVEY, GR SPRINGERYOUNG, M HANSON, KJ AF PIOTROWICZ, SR BEZDEK, HF HARVEY, GR SPRINGERYOUNG, M HANSON, KJ TI ON THE OZONE MINIMUM OVER THE EQUATORIAL PACIFIC-OCEAN SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; EL-NINO; DISTRIBUTIONS; TEMPERATURE; TROPOSPHERE; CHEMISTRY AB Since 1977, several ship and aircraft expeditions to the equatorial Pacific have reported extremely low (less-than-or-equal-to 10 ppbv) or undetectable levels of ozone within the marine boundary layer. Of necessity, field programs from mobile platforms are limited in both their temporal and spatial coverage. However, a 10-year record of observations at the geophysical monitoring for climatic change site in American Samoa suggests that low ozone mixing ratios are a common occurrence and may reflect a spatially variable but permanent region of low ozone in the equatorial Pacific. The spatial and temporal limits of this feature as well as some aspects of the intensity of the minimum appear to be maintained by the large-scale atmospheric circulations of the equatorial Pacific. Perturbations in the large-scale circulations as well as episodic events are reflected in observations of O3 in the equatorial Pacific. Variations in the large-scale, zonal circulation patterns (i.e., Walker circulation) of the equatorial Pacific appear to have a major influence on the spatial distribution of O3 across the equatorial Pacific. The relative importance of variations in large-scale, meridional circulation patterns on the distribution of O3 in the tropical Pacific is uncertain; however, they may be important at latitudes somewhat removed from the equator such as at American Samoa. C1 NOAA, AIR RESOURCES LAB, MIAMI, FL 33149 USA. RP PIOTROWICZ, SR (reprint author), NOAA, ATLANTIC OCEANOG & METEOROL LAB, 4301 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. NR 26 TC 36 Z9 36 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 OCT 20 PY 1991 VL 96 IS D10 BP 18679 EP 18687 DI 10.1029/91JD01809 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GM167 UT WOS:A1991GM16700013 ER PT J AU KAPADIA, G CHEN, CCH REDDY, P SAIER, MH REIZER, J HERZBERG, O AF KAPADIA, G CHEN, CCH REDDY, P SAIER, MH REIZER, J HERZBERG, O TI CRYSTALLIZATION OF THE IIA-DOMAIN OF THE GLUCOSE PERMEASE OF BACILLUS-SUBTILIS SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Note DE PROTEIN CRYSTALLOGRAPHY; GLUCOSE PERMEASE; SUGAR TRANSPORT; PHOSPHOTRANSFERASE SYSTEM; PROTEIN PHOSPHORYLATION ID SUGAR PHOSPHOTRANSFERASE SYSTEM; ESCHERICHIA-COLI; PHOSPHOENOLPYRUVATE; BACTERIA; IIIGLC; SITE C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093. FU NIAID NIH HHS [5R01 AI21702, 2R01 AI14176] NR 13 TC 5 Z9 6 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 20 PY 1991 VL 221 IS 4 BP 1079 EP 1080 PG 2 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GN210 UT WOS:A1991GN21000004 PM 1942043 ER PT J AU KISSLINGER, C HASEGAWA, A AF KISSLINGER, C HASEGAWA, A TI SEISMOTECTONICS OF INTERMEDIATE-DEPTH EARTHQUAKES FROM PROPERTIES OF AFTERSHOCK SEQUENCES SO TECTONOPHYSICS LA English DT Article ID SEISMIC ZONE; MODEL AB Aftershock sequences following two intermediate-depth earthquakes have been analyzed to determine their spatial and temporal distributions. The Kanaga Pass earthquake (m(b) = 6.0) occurred at 105 km depth in the central Aleutian Islands. Data were provided by the Central Aleutians Seismic Network. The Iwaizumi Town earthquake (m(b) = 6.4) occurred at 75 km depth, under northern Honshu, Japan. Data were provided by the network of Tohoku University. For both events the hypocenter distribution of the aftershocks agreed well with focal mechanism solutions derived by others, with down-dip compression for both. Both events were followed by numerous aftershocks that decayed with time initially according to the modified Omori relation, with p-value close to 1. In both cases, activity at a higher rate than that expected from the Omori relation began after several months, without a strong aftershock to trigger it. The Kanaga Pass activity is modeled by two Omori sequences, the second beginning 64 days after the mainshock. The p-values are 0.92 and 1.04, respectively. The corresponding b-values are 1.01 and 1.03. The Iwaizumi Town sequence is modeled by a single Omori sequence, p = 0.96, plus a constant rate of activity, 0.25 events/day, for 63 days, beginning 120.5 days after the mainshock. The b-value of the main sequence was 0.91 +/- 0.14, up to the start of the linear surge, for which the b-value was 1.23 +/- 0.47. No strong aftershock or event in the vicinity of the aftershock zone occurred to trigger the secondary activity, in either case. The cause of the secondary activity is not known. The two sequences occurred in subduction zones with similar properties, and in both cases previous seismicity shows a deficiency of strong earthquakes in the main thrust zone above the aftershock source volumes. A strong creep event, or silent earthquake, in a weakly-coupled interplate contact zone is a plausible explanation for the secondary sequences. The unusual setting of the Iwaizumi event, at the bottom of the upper plane of the double-planed Wadati-Benioff zone under Honshu, may play a role in that case. C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. TOHOKU UNIV,OBSERVAT CTR PREDICT EARTHQUAKES & VOLCAN ERUPT,SENDAI,MIYAGI 980,JAPAN. RP KISSLINGER, C (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 15 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD OCT 20 PY 1991 VL 197 IS 1 BP 27 EP 40 DI 10.1016/0040-1951(91)90398-C PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GN812 UT WOS:A1991GN81200004 ER PT J AU ELSHALL, MS OLAFSDOTTIR, SR MEOTNER, M SIECK, LW AF ELSHALL, MS OLAFSDOTTIR, SR MEOTNER, M SIECK, LW TI ENERGY EFFECTS ON CLUSTER ION DISTRIBUTIONS - BEAM EXPANSION AND THERMOCHEMICAL STUDIES ON MIXED CLUSTERS OF METHANOL AND ACETONITRILE SO CHEMICAL PHYSICS LETTERS LA English DT Article ID AMMONIA BINARY CLUSTERS; GAS-PHASE; MULTIPHOTON IONIZATION; MAGIC NUMBERS; MOLECULE REACTIONS; HYDROGEN-IONS; WATER; SOLVATION; PROTON; ACETONE AB We report the results of joint beam expansion and thermochemical studies on protonated clusters containing hydrogen-bonded chains of methanol and acetonitrile. The cluster distributions show a predominant sequence with the composition H+ (CH3OH)n(CH3CN)2, where the solvent shells are completed by blocking groups on both ends. Even though ionization involves large excess energies, the observed cluster distributions are sensitive to thermochemical differences as small as 1-3 kcal/mol. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. UNIV ICELAND,INST SCI,DUNHAGA 3,ICELAND. RP ELSHALL, MS (reprint author), VIRGINIA COMMONWEALTH UNIV,DEPT CHEM,RICHMOND,VA 23284, USA. RI El-Shall, M. Samy/K-8954-2012 OI El-Shall, M. Samy/0000-0002-1013-4948 NR 37 TC 18 Z9 18 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 OCT 18 PY 1991 VL 185 IS 3-4 BP 193 EP 198 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GN029 UT WOS:A1991GN02900004 ER PT J AU PAPANIKOLAS, JM GORD, JR LEVINGER, NE RAY, D VORSA, V LINEBERGER, WC AF PAPANIKOLAS, JM GORD, JR LEVINGER, NE RAY, D VORSA, V LINEBERGER, WC TI PHOTODISSOCIATION AND GEMINATE RECOMBINATION DYNAMICS OF I2- IN MASS-SELECTED I2-(CO2)N CLUSTER IONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RARE-GAS CLUSTERS; SUPERSONIC MOLECULAR-BEAM; MONTE-CARLO SIMULATION; STATE PROTON-TRANSFER; MULTIPHOTON IONIZATION; CONDENSED PHASE; CARBON-DIOXIDE; IODINE PHOTODISSOCIATION; CHEMICAL-REACTIVITY; ATOM RECOMBINATION AB We report size-dependent photodissociation and germinate recombination dynamics of the I2- chromophore in mass-selected I2-(CO2)n cluster ions, 0 less-than-or-equal-to n less-than-or-equal-to 22, by using nanosecond and picosecond pulsed laser sources in conjunction with a tandem time-of-flight mass spectrometer. Photoexcitation of these cluster ions results in the formation of two types of photofragment ions: I2--based photofragment ions, in which the photodissociated I2- chromophore has recombined and vibrationally relaxed, and I--based photofragment ions, in which an iodine atom has escaped the cluster ion. The "caging fraction", or quantum yield for formation of photofragment ions containing recombined I2-, is strongly dependent on the cluster ion size, varying from zero to unity over the size range studied. Picosecond pump-probe studies reveal a transient bleach in the sequential two-photon absorption of these I2-(CO2)n cluster ions. A single laser pulse time-resolved experiment indicates that the time scale for absorption recovery is almost-equal-to 30 ps for cluster ions with 9 less-than-or-equal-to n less-than-or-equal-to 13 and almost-equal-to 15 ps for n = 15 and 16, with a dramatic decrease in absorption recovery time over the size range 13 less-than-or-equal-to n less-than-or-equal-to 15. These results are interpreted in terms of recent Monte Carlo simulations performed in this laboratory and molecular dynamics studies performed by Amar and Perera. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 150 TC 163 Z9 163 U1 2 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 17 PY 1991 VL 95 IS 21 BP 8028 EP 8040 DI 10.1021/j100174a008 PG 13 WC Chemistry, Physical SC Chemistry GA GL638 UT WOS:A1991GL63800011 ER PT J AU HETZLER, JR CASASSA, MP KING, DS AF HETZLER, JR CASASSA, MP KING, DS TI PRODUCT ENERGY CORRELATIONS IN THE DISSOCIATION OF OVERTONE EXCITED NO DIMER SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NITRIC-OXIDE DIMER; RESOLUTION INFRARED-SPECTROSCOPY; VIBRATIONAL PREDISSOCIATION; MOLECULAR-BEAM; PHOTODISSOCIATION; STATE; COMPLEXES; DYNAMICS; (NO)2; HF AB The photodissociation spectra, predissociative lifetime, fragment internal state and translational energy distributions, and product energy and vector correlations of overtone excited nitric oxide dimer, (NO)2, have been measured using pulsed molecular beam and Doppler profile analysis techniques. The nu-1 + nu-5 and 2-nu-5 modes of (NO)2 were excited by infrared pumping, and NO fragments were detected with sub-Doppler resolution by laser-induced fluorescence. The predissociative lifetimes of nu-1 + nu-5 and 2-nu-5 excited NO dimer are 34 +/- 6 and 20 +/- 3 ps, respectively. At least 97% of the dissociations produce NO(upsilon = 1) + NO(upsilon = 0); no product in the (upsilon = 0) + (upsilon = 0) channel was detected. For both modes, about 85% of the energy available after vibrational energy distribution goes into relative translational energy of the fragments. Only 3% of this available energy appears in fragment rotational energy. The propensities of the three spin-orbit correlated channels were measured for both modes. For nu-1 + nu-5 excitation 77 +/- 7% of the fragments are formed along the 2-PI-1/2-2-PI-3/2 channel and 21 +/- 5% via 2-PI-1/2-2-PI-1/2. In contrast, 39 +/- 6% of the dissociations following 2-nu-5 excitation proceed via the 2-PI-1/2-2-PI-1/2 channel. The only nonzero vector correlation observed is the fragment recoil anisotropy, which depends on the rotational transition excited in the parent. The results are discussed in terms of the dissociation and energy partitioning mechanisms. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. AERODYNE RES INC,BILLERICA,MA 01821. NR 45 TC 82 Z9 82 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 17 PY 1991 VL 95 IS 21 BP 8086 EP 8095 DI 10.1021/j100174a017 PG 10 WC Chemistry, Physical SC Chemistry GA GL638 UT WOS:A1991GL63800020 ER PT J AU BAUMERT, T BUHLER, B GROSSER, M THALWEISER, R WEISS, V WIEDENMANN, E GERBER, G AF BAUMERT, T BUHLER, B GROSSER, M THALWEISER, R WEISS, V WIEDENMANN, E GERBER, G TI FEMTOSECOND TIME-RESOLVED WAVE PACKET MOTION IN MOLECULAR MULTIPHOTON IONIZATION AND FRAGMENTATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RYDBERG STATES; PHOTOELECTRON-SPECTROSCOPY; KINETIC-ENERGY; EXCITED-STATES; ALKALI DIMERS; AUTOIONIZATION; NA-2; H-2; DISTRIBUTIONS; DISSOCIATION AB The dynamics of molecular multiphoton ionization and fragmentation of a diatomic molecule (Na2) have been studied in molecular beam experiments. Femtosecond laser pulses from an amplified colliding-pulse mode-locked (CPM) ring dye laser are employed to induce and probe the molecular transitions. The final continuum states are analyzed by photoelectron spectroscopy, by ion mass spectrometry and by measuring the kinetic energy of the formed ionic fragments. Pump-probe spectra employing 70-fs laser pulses have been measured to study the time dependence of molecular multiphoton ionization and fragmentation. The oscillatory structure of the transient spectra showing the dynamics on the femtosecond time scale can best be understood in terms of the motion of wave packets in bound molecular potentials. The transient Na2+ ionization and the transient Na+ fragmentation spectra show that contributions from direct photoionization of a singly excited electronic state and from excitation and autoionization of a bound doubly excited molecular state determine the time evolution of molecular multiphoton ionization. C1 UNIV FREIBURG,FAK PHYS,W-7800 FREIBURG,GERMANY. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB,BOULDER,CO 80309. RI Baumert, Thomas/D-3962-2009 OI Baumert, Thomas/0000-0003-1760-7493 NR 43 TC 98 Z9 98 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 17 PY 1991 VL 95 IS 21 BP 8103 EP 8110 DI 10.1021/j100174a019 PG 8 WC Chemistry, Physical SC Chemistry GA GL638 UT WOS:A1991GL63800022 ER PT J AU DRIESSEN, JPJ SMITH, CJ LEONE, SR AF DRIESSEN, JPJ SMITH, CJ LEONE, SR TI RELATIVE CROSS-SECTIONS FOR CA(1F3) SUBLEVELS (M-ABSOLUTE VALUE = 0-3) THROUGH ALIGNMENT EFFECTS IN COLLISIONAL ENERGY-TRANSFER - CA(4S4F,1F3) + RG -] CA(4P2,1S0) + RG AS A FUNCTION OF RARE-GAS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RESONANT CHARGE-TRANSFER; ORBITAL ALIGNMENT; ASSOCIATIVE IONIZATION; ANGULAR-MOMENTUM; SEMICLASSICAL CALCULATIONS; MOLECULAR-STATES; BEAM EXPERIMENT; EXCITED ATOMS; RARE-GAS; SCATTERING AB The Ca(4s4f,1F3) state is prepared by three-photon excitation using three linearly polarized lasers. Subsequent collisions with rare-gas atoms (He, Ne, Ar, Kr, or Xe) induce a population transfer to the near-resonant Ca(4p2,1S0) state. The collisional energy-transfer process is measured as a function of the alignment angle beta, between the average relative velocity vector and the laser polarizations. For the first time cos (6 beta) behavior of the cross section is observed in collision processes. The angular wave function of the Ca(1F3) state depends on the angles of the three laser polarizations with respect to each other. The alignment effect is determined for two different initial angular wave functions, Y3,0 and (Y3,-1 - Y3,1)/ square-root 2, which display dramatically different alignment dependences. Each alignment curve can be analyzed in terms of the same set of relative cross sections for the individual Ca(1F3) magnetic sublevels, providing an independent verification of the data. The relative cross sections sigma\M\ vary smoothly as a function of rare gas, with Ar, Kr, and Xe having the largest alignment effect: sigma-o almost-equal-to 3.7 sigma\3\. A remarkable propensity for the M = 0 cross section sigma-0 is observed, which may be explained on the basis of radial coupling between the 1F3 state and the 1S0 state, which is exclusively M = 0. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NR 39 TC 20 Z9 20 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 17 PY 1991 VL 95 IS 21 BP 8163 EP 8169 DI 10.1021/j100174a027 PG 7 WC Chemistry, Physical SC Chemistry GA GL638 UT WOS:A1991GL63800030 ER PT J AU BECK, CM AF BECK, CM TI CLASSICAL-ANALYSIS - A LOOK AT THE PAST, PRESENT, AND FUTURE SO ANALYTICAL CHEMISTRY LA English DT Article AB Since the 1940s classical analysis has taken a back seat to instrumental analysis. Charles M. Beck II of the National Institute of Standards and Technology traces the history of chemistry and argues that a revival of teaching classical analysis is vital to the interests of American industry. RP BECK, CM (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 38 TC 17 Z9 17 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1991 VL 63 IS 20 BP A993 EP A1002 DI 10.1021/ac00020a002 PG 10 WC Chemistry, Analytical SC Chemistry GA GJ962 UT WOS:A1991GJ96200002 ER PT J AU HINDAR, K RYMAN, N UTTER, F AF HINDAR, K RYMAN, N UTTER, F TI GENETIC-EFFECTS OF AQUACULTURE ON NATURAL FISH POPULATIONS SO AQUACULTURE LA English DT Article ID ATLANTIC SALMON; TROUT AB This note summarizes a review by Hindar et al. (1991) outlining the genetic consequences of aqua-culture on natural fish populations. Publication of the full paper (Hindar et al., 1991) has preceded that of the present volume; this note is included to permit a more complete presentation of the papers read at the Loen symposium on interactions between cultured and wild Atlantic salmon (Salmo salar). C1 NATL MARINE FISHERIES SERV,NW FISHERIES CTR,SEATTLE,WA 98112. RP HINDAR, K (reprint author), NORWEGIAN INST NAT RES,TUNGASLETTA 2,N-7004 TRONDHEIM,NORWAY. NR 18 TC 19 Z9 21 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD OCT 15 PY 1991 VL 98 IS 1-3 BP 259 EP 261 DI 10.1016/0044-8486(91)90389-O PG 3 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GP584 UT WOS:A1991GP58400024 ER PT J AU FRASER, GT PINE, AS KREINER, WA SUENRAM, RD AF FRASER, GT PINE, AS KREINER, WA SUENRAM, RD TI OPTOTHERMAL-DETECTED MICROWAVE-SIDE-BAND CO2-LASER SPECTROSCOPY OF NCH-NH3 SO CHEMICAL PHYSICS LA English DT Article ID INFRARED-ABSORPTION SPECTROSCOPY; IR LASER SPECTROSCOPY; VIBRATIONAL PREDISSOCIATION; MOLECULAR MECHANICS; COMPLEXES; CLUSTERS; BAND; GAS; HF; SPECTRA AB A microwave-sideband CO2 laser is used together with an electric-resonance optothermal spectrometer to measure the infrared spectrum of the NH3 umbrella vibration in NCH-NH3 at a resolution of almost-equal-to 3 MHz. The infrared radiation is produced by mixing Lamb-dip-stabilized CO2 laser radiation with synthesizer-derived microwave radiation in a CdTe-buffered GaAs stripline electrooptic waveguide modulator. For NCH-NH3 a symmetric top spectrum is observed with a band origin at 1041.7 cm-1, blue-shifted almost-equal-to 91.8 cm-1 from the hypothetical inversion-free nu-2 band origin of free NH3, which indicates a decrease in the van der Waals zero-point binding energy, D0, for the excited state. The observed DELTA-B of - 14.3 MHz, implying a hydrogen-bond extension, is consistent with this blue shift. The vibrationally excited complex does not predissociate within the almost-equal-to 1 ms transit time between the laser excitation region and the bolometer detector, implying that D0 is greater than the laser frequency, almost-equal-to 1042 cm-1. RP FRASER, GT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Schaff, William/B-5839-2009 NR 43 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 15 PY 1991 VL 156 IS 3 BP 523 EP 531 DI 10.1016/0301-0104(91)89019-7 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH862 UT WOS:A1991GH86200019 ER PT J AU NORTON, GV WERBY, MF AF NORTON, GV WERBY, MF TI A NUMERICAL TECHNIQUE TO DESCRIBE ACOUSTICAL SCATTERING AND PROPAGATION FROM AN OBJECT IN A WAVE-GUIDE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELASTIC SHELLS; RESONANCE SCATTERING; SPHEROIDAL SHELLS; T-MATRIX; FLUID; WAVES AB The treatment of scattering from submerged objects in an unbounded environment is of considerable interest to both the academic and technological communities. Several approaches have yielded results for different classes of problems and have proven manageable for the free-environment case. Scattering in a confined environment is difficult to express in a form useful for calculation because the effects from the scattered object couple with the boundary effects. The purpose of this work is to propose a numerical scheme that will adequately describe scattering from realistic objects in a confined environment. Some realistic objects of interest are elongated spheroids and cylinders with rounded end caps. Boundary conditions of interest range from those associated with rigid objects to those associated with elastic shells. The object in a waveguide problem is examined in approximate numerical schemes rather than with attempts at exact solutions. The starting point will be the solution of the incident field in terms of normal modes. Next, transition matrix is used that relates the incident field to the scattered field. The transition matrix, which is obtained from Waterman's extended boundary condition method, does not account for boundaries other than that of the object. The solution is then coupled with a waveguide solution to satisfy all boundary conditions. The method, an application of Huygens' principle, couples the solutions and leads to a manageable solution of the problem. This method also satisfies all appropriate boundary conditions and yields a continuous solution throughout space. Details and examples of this method are presented. C1 TULANE UNIV,GRAD SCH,DEPT PHYS,NEW ORLEANS,LA 70118. RP NORTON, GV (reprint author), NOAA,RES LAB,ACOUST SIMULAT BRANCH,CODE 221,STENNIS SPACE CTR,MS 39529, USA. NR 41 TC 11 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1991 VL 70 IS 8 BP 4101 EP 4112 DI 10.1063/1.349132 PG 12 WC Physics, Applied SC Physics GA GL023 UT WOS:A1991GL02300014 ER PT J AU HUANG, D KALLERGI, M AUBEL, J SUNDARAM, S DESALVO, G COMAS, J AF HUANG, D KALLERGI, M AUBEL, J SUNDARAM, S DESALVO, G COMAS, J TI LATTICE DAMAGE AND ATOMIC MIXING INDUCED BY AS++ IMPLANTATION AND THERMAL ANNEALING IN ALAS/GAAS MULTIPLE QUANTUM-WELL STRUCTURES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAAS-ALAS SUPERLATTICES; ION-IMPLANTATION; SUPER-LATTICE; ALGAAS INTERFACES; ZN DIFFUSION; INTERDIFFUSION; DISORDER; DEPENDENCE; ALXGA1-XAS; GAP AB The lattice damage and the nature of the atomic intermixing of Al and Ga induced by As+ + implantation and thermal annealing in AlAs/GaAs multiple quantum-well structures were investigated. The photoluminescence spectra, which show multiple peaks after implantation and annealing, were analyzed based on the shifts of the excitonic peaks arising from quantum wells located at different depths. The depth profiles of intermixing were obtained using a procedure of successive layer-by-layer chemical etching followed by photoluminescence measurements. It is found that the atomic mixing is maximum near the sample surface and decreases monotonically with depth, suggesting that the profiles follow more closely the ion induced damage than the ion density. It is also observed that the radiation damage extends beyond 1-mu-m. Within 0.3-mu-m from the surface, the damage is relatively heavy and the atomic intermixing increases rapidly with ion dose. Beyond 0.3-mu-m, the degree of intermixing is only sensitive to the anneal temperature but not to the implantation dose. The results show that both direct collisions and interdiffusion are responsible for the atomic mixing. For the samples implanted with ion doses below 10(14) cm-2 and annealed at 650-degrees-C, the optical activation from radiation damage is appreciable. However, the interdiffusion becomes important only at temperatures near and above 800-degrees-C. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP HUANG, D (reprint author), UNIV S FLORIDA,DEPT PHYS,TAMPA,FL 33620, USA. NR 33 TC 14 Z9 14 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 OCT 15 PY 1991 VL 70 IS 8 BP 4181 EP 4189 DI 10.1063/1.349142 PG 9 WC Physics, Applied SC Physics GA GL023 UT WOS:A1991GL02300024 ER PT J AU BAND, YB JULIENNE, PS AF BAND, YB JULIENNE, PS TI POPULATION TRANSFER BY MULTIPLE STIMULATED RAMAN-SCATTERING SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTILEVEL SYSTEMS; VIBRATIONAL LEVELS; STATE; SPECTROSCOPY; DYNAMICS; PULSES AB We present results of density matrix calculations describing population transfer in a four level system via stimulated Raman scattering with three laser pulses whose frequencies are in (or nearly in) resonance with the transitions between the levels. A high degree of transfer to the terminal level is possible via transitions through the two intermediate excited levels, despite the large decay rates of both levels compared with the inverse of the laser pulse durations, provided that the pulse timing sequences are correctly adjusted. Hence multiple stimulated Raman scattering can be an efficient method of moving population into a given molecular level. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP BAND, YB (reprint author), BEN GURION UNIV NEGEV,DEPT CHEM,IL-84105 BEER SHEVA,ISRAEL. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 16 TC 36 Z9 37 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 OCT 15 PY 1991 VL 95 IS 8 BP 5681 EP 5685 DI 10.1063/1.461642 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GJ592 UT WOS:A1991GJ59200020 ER PT J AU KEY, J PECKHAM, S AF KEY, J PECKHAM, S TI PROBABLE ERRORS IN WIDTH DISTRIBUTIONS OF SEA ICE LEADS MEASURED ALONG A TRANSECT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ARCTIC OCEAN; SONAR AB The degree of error expected in the measurement of widths of sea ice leads along a single transect are examined in a probabilistic sense under assumed orientation and width distributions, where both isotropic and anisotropic lead orientations are examined. Methods are developed for estimating the distribution of "actual" widths (measured perpendicular to the local lead orientation) knowing the "apparent" width distribution (measured along the transect), and vice versa. The distribution of errors, defined as the difference between the actual and apparent lead width, can be estimated from the two width distributions, and all moments of this distribution can be determined. The problem is illustrated with Landsat imagery and the procedure is applied to a submarine sonar transect. Results are determined for a range of geometries, and indicate the importance of orientation information if data sampled along a transect are to be used for the description of lead geometries. While the application here is to sea ice leads, the methodology can be applied to measurements of any linear feature. C1 UNIV COLORADO,DEPT GEOL,BOULDER,CO 80309. RP KEY, J (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI Key, Jeffrey/F-5597-2010 OI Key, Jeffrey/0000-0001-6109-3050 NR 12 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1991 VL 96 IS C10 BP 18417 EP 18423 DI 10.1029/91JC01843 PG 7 WC Oceanography SC Oceanography GA GL027 UT WOS:A1991GL02700006 ER PT J AU BASCH, H KRAUSS, M STEVENS, WJ AF BASCH, H KRAUSS, M STEVENS, WJ TI COMPARISON OF THE ELECTRONIC-STRUCTURE OF THE P-O AND P-S BONDS SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article ID MOLECULAR-ORBITAL CALCULATIONS; ABINITIO STRUCTURES; PHOSPHORUS-ACIDS; META-PHOSPHATE; GAS-PHASE; ESTERS; SYMMETRY; ANIONS; H2POH; ORDER AB The electronic structures of the P-O and P-S bonds were compared in PO3-, HPO3, H2PO4-, H3PO4 and their monosubstituted sulfur analogues. Plots of the charge difference density around the P-X (X = O or S) bond support a polar structure for both the oxygen and the sulfur anions. The proton affinities and the binding of a single water molecule at the oxygen and sulfur sites are comparable, illustrating the polarity of both the P-O and the P-S bond. The energy surface for the phosphate and the phosphorothioate anions as a function of the torsional angle for the orientation of the O-H bonds also demonstrates the polarity of the two bonds. Difference density plots comparing the neutral and ionic phosphates suggest that this bond is also similar in both neutral and ionic systems. An ionic P-O and P-S bond provides a better representation of the structure than a double bond, even for the neutral molecules. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NATL INST STAND & TECHNOL, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. RP BASCH, H (reprint author), BAR ILAN UNIV, DEPT CHEM, RAMAT GAN, ISRAEL. NR 38 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD OCT 15 PY 1991 VL 81 IS 3-4 BP 277 EP 291 PG 15 WC Chemistry, Physical SC Chemistry GA GN753 UT WOS:A1991GN75300006 ER PT J AU BERK, NF AF BERK, NF TI SCATTERING PROPERTIES OF THE LEVELED-WAVE MODEL OF RANDOM MORPHOLOGIES SO PHYSICAL REVIEW A LA English DT Article ID X-RAY-SCATTERING; BICONTINUOUS STRUCTURE; MICROEMULSIONS; SILICA AB In the leveled-wave model, random porous morphologies are stimulated by discrete maps of continuous stochastic standing waves generated by adding sinusoids over suitable distributions of wave vectors and phase constants. The mathematical structures obtained this way appear to be useful models for certain kinds of random geometries, such as the bicontinuous morphologies that occur in microemulsions and porous glasses. Properties of the leveled-wave method are developed, and the scattering behavior is derived. Scattering from an arbitrary three-phase system can be analyzed by adding different instances of scattering from a generalized film morphology in which the scattering phase is confined to the interior of the interspatial region bounded by two leveled-wave interfaces that are separated everywhere. General results for this interspace scattering are derived. Fractal surfaces, dimension 2 less-than-or-equal-to D less-than-or-equal-to 3, are incorporated into the leveled-wave scheme by using a wave-number distribution having an appropriate long-tailed asymptotic behavior. Scenarios are discussed for the scattering as D --> 2 from above and for D --> 3 from below. For D = 3 the asymptotic scattering falls faster than algebraically as the scattering wave vector Q --> infinity. RP BERK, NF (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 27 TC 78 Z9 79 U1 1 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 OCT 15 PY 1991 VL 44 IS 8 BP 5069 EP 5079 DI 10.1103/PhysRevA.44.5069 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GM060 UT WOS:A1991GM06000035 ER PT J AU GREENE, GL DEWEY, MS KESSLER, EG FISCHBACH, E AF GREENE, GL DEWEY, MS KESSLER, EG FISCHBACH, E TI TEST OF SPECIAL RELATIVITY BY A DETERMINATION OF THE LORENTZ LIMITING VELOCITY - DOES E = MC2 SO PHYSICAL REVIEW D LA English DT Note ID EQUIVALENCE PRINCIPLE; SPATIAL ANISOTROPY; SPECTROSCOPY; REMEASUREMENT; INVARIANCE; RADIATION; ISOTROPY; CONSTANT; PHYSICS; SPACE AB We describe a method by which existing precision measurements may be used to provide a new laboratory test of the special theory of relativity. In this test the speed of light c(em) is compared to the limiting velocity of massive particles, c(m). Although it is conventionally assumed that c(em) = c(m) = c, this need not be the case in phenomenological alternatives to special relativity. Our results impose limits on the quantity (1 - c(m)/c(em)). Unlike null tests of special relativity, this limit does not depend on assumptions concerning the motion of the laboratory with respect to a preferred frame. C1 PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. RP GREENE, GL (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 45 TC 24 Z9 24 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 1991 VL 44 IS 8 BP R2216 EP R2219 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA GL467 UT WOS:A1991GL46700003 ER PT J AU JULIENNE, PS HEATHER, R AF JULIENNE, PS HEATHER, R TI LASER MODIFICATION OF ULTRACOLD ATOMIC-COLLISIONS - THEORY SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGULAR-MOMENTUM; ASSOCIATIVE IONIZATION; MOLECULAR-COLLISIONS; FIELD; POTENTIALS; NA AB Specific molecular mechanisms are proposed for associative ionization collisions of ultracold sodium atoms in a hybrid optical trap. When an intense, strongly detuned optical trap laser is on, the ionization rate is modulated by molecular bound-state resonances which are strongly affected by field dressing. When the weak, slightly detuned optical molasses lasers are on to provide cooling, an excitation mechanism which produces the two excited atoms at large internuclear separation in different hyperfine states accounts for the lower observed ionization rate. RP JULIENNE, PS (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 23 TC 35 Z9 35 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 1991 VL 67 IS 16 BP 2135 EP 2138 DI 10.1103/PhysRevLett.67.2135 PG 4 WC Physics, Multidisciplinary SC Physics GA GJ640 UT WOS:A1991GJ64000006 ER PT J AU LETT, PD JESSEN, PS PHILLIPS, WD ROLSTON, SL WESTBROOK, CI GOULD, PL AF LETT, PD JESSEN, PS PHILLIPS, WD ROLSTON, SL WESTBROOK, CI GOULD, PL TI LASER MODIFICATION OF ULTRACOLD COLLISIONS - EXPERIMENT SO PHYSICAL REVIEW LETTERS LA English DT Article ID LOSSES; ATOMS; TRAP AB Julienne recently predicted a dramatic laser-intensity-dependent modification of the associative ionization (AI) rate in ultracold collisions. We observe such a modification, but with a behavior inconsistent with the originally proposed mechanism. Furthermore, we find resonant structure in the spectrum of AI rate versus laser frequency, showing the importance of molecular bound states in the AI process. These observations are explained in a new theoretical treatment by Julienne and Heather (preceding Letter). C1 NATL INST STAND & TECHNOL,DIV ATOM PHYS,GAITHERSBURG,MD 20899. AARHUS UNIV,INST PHYS,DK-8000 AARHUS,DENMARK. UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06268. RP LETT, PD (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Jessen, Poul/A-5433-2009; Westbrook, Christoph/B-6092-2009; rolston, steven/L-5175-2013 OI Westbrook, Christoph/0000-0002-6490-0468; rolston, steven/0000-0003-1671-4190 NR 15 TC 61 Z9 62 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 1991 VL 67 IS 16 BP 2139 EP 2142 DI 10.1103/PhysRevLett.67.2139 PG 4 WC Physics, Multidisciplinary SC Physics GA GJ640 UT WOS:A1991GJ64000007 ER PT J AU LIAO, DI KAPADIA, G REDDY, P SAIER, MH REIZER, J HERZBERG, O AF LIAO, DI KAPADIA, G REDDY, P SAIER, MH REIZER, J HERZBERG, O TI STRUCTURE OF THE IIA-DOMAIN OF THE GLUCOSE PERMEASE OF BACILLUS-SUBTILIS AT 2.2-A RESOLUTION SO BIOCHEMISTRY LA English DT Article ID SUGAR PHOSPHOTRANSFERASE SYSTEM; HISTIDINE-CONTAINING PROTEIN; ESCHERICHIA-COLI; BACTERIAL PHOSPHOENOLPYRUVATE; MACROMOLECULAR CRYSTALLOGRAPHY; PHOSPHOCARRIER PROTEIN; NUCLEOTIDE-SEQUENCE; N-ACETYLGLUCOSAMINE; SECONDARY STRUCTURE; TERTIARY STRUCTURE AB The crystal structure of the IIA domain of the glucose permease of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) from Bacillus subtilis has been determined at 2.2-angstrom resolution. Refinement of the structure is in progress, and the current R-factor is 0.201 (R = SIGMA-h parallel-to F(o)\ - \F(c) parallel-to/SIGMA-h\F(o)\, where \F(o)\ and \F(c)\ are the observed and calculated structure factor amplitudes, respectively) for data between 6.0- and 2.2-angstrom resolution for which F greater-than-or-equal-to 2-sigma(F). This is an antiparallel beta-barrel structure that incorporates "Greek key" and "jellyroll" topological motifs. A shallow depression is formed at the active site by part of the beta-sheet and an OMEGA-loop flanking one side of the sheet. His83, the histidyl residue which is the phosphorylation target of HPr and which transfers the phosphoryl group to the IIB domain of the permease, is located at the C-terminus of a beta-strand. The N-epsilon atom is partially solvated and also interacts with the N-epsilon atom of a second histidyl residue, His68, located at the N-terminus of an adjacent beta-strand, suggesting they share a proton. The geometry of the hydrogen bond is imperfect, though. Electrostatic interactions with other polar groups and van der Waals contacts with the side chains of two flanking phenylalanine residues assure the precise orientation of the imidazole rings. The hydrophobic nature of the surface around the His83-His68 pair may be required for protein-protein recognition by HPr or/and by the IIB domain of the permease. The side chains of two aspartyl residues, Asp31 and Asp87, are oriented toward each other across a narrow groove, about 7 angstrom from the active-site His83, suggesting they may play a role in protein-protein interaction. A model of the phosphorylated form of the molecule is proposed, in which oxygen atoms of the phosphoryl group interact with the side chain of His68 and with the main-chain nitrogen atom of a neighboring residue, Val89. The model, in conjunction with previously reported site-directed mutagenesis experiments, suggests that the phosphorylation of His83 may be accompanied by the protonation of His68. This may be important for the interaction with the IIB domain of the permease and/or play a catalytic role in the phosphoryl transfer from IIA to IIB. C1 UNIV MARYLAND, MARYLAND BIOTECHNOL INST, CTR ADV RES BIOTECHNOL, 9600 GUDELSKY DR, ROCKVILLE, MD 20850 USA. NATL INST STAND & TECHNOL, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. UNIV CALIF SAN DIEGO, DEPT BIOL, LA JOLLA, CA 92093 USA. NR 61 TC 90 Z9 92 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 8 PY 1991 VL 30 IS 40 BP 9583 EP 9594 DI 10.1021/bi00104a004 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA GJ473 UT WOS:A1991GJ47300004 PM 1911744 ER PT J AU OCONNELL, J SULLIVAN, F LIBES, D ORLANDINI, E TESI, MC STELLA, AL EINSTEIN, TL AF OCONNELL, J SULLIVAN, F LIBES, D ORLANDINI, E TESI, MC STELLA, AL EINSTEIN, TL TI SELF-AVOIDING RANDOM SURFACES - MONTE-CARLO STUDY USING OCT-TREE DATA-STRUCTURE SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID PLANAR RANDOM SURFACES; CRITICAL-BEHAVIOR; LATTICE; DIMENSION AB Self-avoiding random surfaces on a cubic lattice are studied by extensive Monte Carlo sampling. The surfaces have empty boundary and the topology of a 2-sphere. An oct-tree data-structure allows good statistics to be obtained for surfaces whose plaquette number is up to an order of magnitude greater than in previous investigations. The new simulation strategy is explained in detail and compared with previous ones. The critical plaquette fugacity, mu-1, and the entropic exponent, theta, are determined by maximum likelihood methods and by logarithmic plots of the average surface area versus fugacity. The latter approach, which produces results having much better convergence by taking advantage of the scaling properties of several runs at various fugacities, leads to the estimates mu = 1.729 +/- 0.036 and theta = 1.500 +/- 0.026. Linear regression estimates for the radius of gyration exponent give nu = 0.509 +/- 0.004, while the asymptotic ratio of surface area over average volume enclosed approaches a finite value 3.18 +/- 0.03. Our results give strong corroborating evidence that this long-controversial problem belongs to the universality class of branched polymers. C1 NATL INST STAND & TECHNOL,CTR COMP & APPL MATH,GAITHERSBURG,MD 20899. UNIV BOLOGNA,DIPARTMENTO FIS,I-40126 BOLOGNA,ITALY. SEZIONE IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. OI Einstein, Theodore L./0000-0001-6031-4923 NR 27 TC 23 Z9 23 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD OCT 7 PY 1991 VL 24 IS 19 BP 4619 EP 4635 DI 10.1088/0305-4470/24/19/024 PG 17 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA GK240 UT WOS:A1991GK24000024 ER PT J AU QUIGLEY, MA VANDERPLOEG, HA AF QUIGLEY, MA VANDERPLOEG, HA TI INGESTION OF LIVE FILAMENTOUS DIATOMS BY THE GREAT-LAKES AMPHIPOD, DIPOREIA SP - A CASE-STUDY OF THE LIMITED VALUE OF GUT CONTENTS ANALYSIS SO HYDROBIOLOGIA LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL COLLOQUIUM ON AMPHIPODA CY SEP 14-16, 1990 CL UNIV MARINE, DARLING MARINE CTR, WALPOLE, ME HO UNIV MARINE, DARLING MARINE CTR DE AMPHIPOD; DIPOREIA; DIATOMS; FEEDING ID PONTOPOREIA-AFFINIS; VERTICAL-DISTRIBUTION; LIPID-CONTENT; MICHIGAN; HOYI; REGENERATION; MACROINVERTEBRATES; PHYTOPLANKTON; POPULATIONS; SEDIMENTS AB Individuals of the Great Lakes amphipod, Diporeia sp. (formerly named Pontoporeia hoyi) were collected from a 45-m deep station in southeastern Lake Michigan and isolated in small laboratory feeding vessels at 4-degrees-C, after the animals had voided their guts over a 24-hour period. Over a 20-day period, following introduction of a single ration of live cells of the filamentous diatom, Melosira varians, 9 of 10 animals had ingested this material, and 7 of these 9 individuals had deposited fecal pellets. Subsequent examination of gut contents and fecal pellets showed that although animals had ingested whole algal cells/filaments, little of the material in gut contents or fecal pellets bore any identifiable structural similarity to cells/filaments prior to ingestion. The results suggest that earlier studies of pontoporeiid gut contents may seriously underestimate the importance of algal components in the amphipod's diet and imply that Diporeia sp. growth and production may be more closely linked to primary production than previously thought. RP QUIGLEY, MA (reprint author), US DEPT COMMERCE,NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. OI Vanderploeg, Henry/0000-0003-1358-8475 NR 35 TC 20 Z9 20 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD OCT 4 PY 1991 VL 223 BP 141 EP 148 DI 10.1007/BF00047635 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GR167 UT WOS:A1991GR16700015 ER PT J AU BASCH, H KRAUSS, M STEVENS, WJ AF BASCH, H KRAUSS, M STEVENS, WJ TI ANION BINDING TO POLAR-MOLECULES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; PHOSPHINE OXIDE; ABINITIO; PHOSPHORUS; CHEMISTRY; SYMMETRY; BONDS AB The interaction of phosphoric acid and chlorine-substituted phosphoric acid with hydroxyl and chlorine anions yields a number of hydrogen-bonded and five-coordinate adducts. Stable hydrogen-bonded structures are found both for adducts with OH- and Cl- and for proton-transferred structures involving H2O in the complexes H4PO5-, H3PO4Cl-, and H2PO3Cl-. The hydrogen bond energy of the OH- and Cl- adducts is calculated to be large due to the polar character of the P-O and O-H bonds. Ligand-field analysis of the hydrogen bonding determines the electrostatic interaction as dominant for these adducts. Five-coordinate phosphorus structures corresponding to reaction intermediates are also found at a higher energy than the hydrogen-bonded structures. These adducts have very polar bonds. Axial Cl ligands are completely dissociative in all studied structures. Stability and binding energy trends upon chlorine substitution are related to the local polarity of the bonds. C1 NATL INST STAND & TECHNOL, DIV BIOTECHNOL, GAITHERSBURG, MD 20899 USA. BAR ILAN UNIV, DEPT CHEM, RAMAT GAN, ISRAEL. NR 27 TC 3 Z9 3 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 3 PY 1991 VL 95 IS 20 BP 7673 EP 7679 DI 10.1021/j100173a023 PG 7 WC Chemistry, Physical SC Chemistry GA GH893 UT WOS:A1991GH89300023 ER PT J AU SLAGLE, IR BATT, L GMURCZYK, GW GUTMAN, D TSANG, W AF SLAGLE, IR BATT, L GMURCZYK, GW GUTMAN, D TSANG, W TI UNIMOLECULAR DECOMPOSITION OF THE NEOPENTYL RADICAL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID COLLISION RATE CONSTANTS; ENERGY-TRANSFER; COMBUSTION; KINETICS; C2H5; CH3 AB The kinetics of the unimolecular decomposition of the neopentyl radical has been investigated. Experimentally, the decomposition was monitored in time-resolved experiments by using a heatable tubular reactor coupled to a photoionization mass spectrometer. The radicals were produced indirectly by pulsed excimer laser photolysis of CCl4 (to produce CCl3 + Cl) followed by the rapid reaction between the Cl atoms and neopentane to produce neo-C5H11 + HCl. Unimolecular rate constants were determined as a function of bath gas (He, N2, and Ar), temperature (10 temperatures between 560 and 650 K), and bath gas density ((3-30) x 10(16) molecules cm-3 (He) and (6-12) x 10(16) (N2, Ar)). The data were fitted within the framework of RRKM theory by using a vibrational model. The high-pressure rate constant in the temperature range studied was determined to be k(neopentyl --> isobutene + CH3) = 10(13.9 +/- 0.5) exp(-30.9 +/- 1.0 kcal mol-1/RT) s-1. The average step sizes down for the bath gases used (adjusted parameters in the RRKM calculations) are comparable: 200 (He), 130 (N2), and 140 (Ar) cm-1 (all +/- 60 cm-1). The high-pressure-limit rate constant expression for the reverse reaction, nonterminal addition of CH3 to isobutene, was obtained from thermochemical calculations by using the results of this study: k(CH3 + isobutene --> neopentyl) = 3.7 x 10(-13) exp(-10.6 kcal mol-1/RT) cm3 molecule-1 s-1. The Arrhenius parameters of this addition reaction indicate that nonterminal addition is inhibited relative to terminal addition mostly by a larger energy barrier to addition, as opposed to possible entropic effects. C1 CATHOLIC UNIV AMER,DEPT CHEM,WASHINGTON,DC 20064. NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. UNIV ABERDEEN,DEPT CHEM,ABERDEEN AB9 1FX,SCOTLAND. NR 29 TC 42 Z9 42 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD OCT 3 PY 1991 VL 95 IS 20 BP 7732 EP 7739 DI 10.1021/j100173a034 PG 8 WC Chemistry, Physical SC Chemistry GA GH893 UT WOS:A1991GH89300034 ER PT J AU INTRILIGATOR, DS DRYER, M AF INTRILIGATOR, DS DRYER, M TI A KICK FROM THE SOLAR-WIND AS THE CAUSE OF COMET HALLEYS FEBRUARY 1991 FLARE SO NATURE LA English DT Article ID PIONEER-10; SHOCKS AB KNOWLEDGE of the interaction of comets with the solar wind 1,2 was greatly advanced during the 1986 passage of comet Halley, which was studied in situ and by remote sensing more thoroughly than any previous comet flyby 3,4. Of particular interest and novelty was the large flare 5 that Halley was seen to produce on 12 February 1991, when it was 14.3 AU from the Sun and 18-degrees below the ecliptic plane. There have been further outbursts, most recently on 17 March 6. We note that the Sun has been unusually active in recent months, and suggest that a shock wave, generated by the solar flare and propagating through the interplanetary medium, could have caused the comet to flare. For example, we show that a solar flare on 31 January could plausibly have produced a shock wave that would have reached Halley on 12 February, and would have been sufficiently strong to crack the comet's crust of fluffy ice. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP INTRILIGATOR, DS (reprint author), CARMEL RES CTR,POB 1732,SANTA MONICA,CA 90406, USA. NR 16 TC 23 Z9 23 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD OCT 3 PY 1991 VL 353 IS 6343 BP 407 EP 409 DI 10.1038/353407a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GH606 UT WOS:A1991GH60600048 ER PT J AU CAHN, JW AF CAHN, JW TI STABILITY, MICROSTRUCTURAL EVOLUTION, GRAIN-GROWTH, AND COARSENING IN A 2-DIMENSIONAL 2-PHASE MICROSTRUCTURE SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID ALLOYS AB The stability of certain microstructural features and how this affects grain growth and coarsening in a two-dimensional polycrystalline two-phase material with isotropic energies for the two grain boundaries and the interphase interface is examined using classical concepts. A catalog of stable microstructural features depends on surface-energy ratios; it is shown to include a four-grain junction that is stable for a range of surface-energy ratios, and, for a given set of ratios, is stable over a range of angles. Three-grain junctions and grain boundaries had been known to have a limited range of stability with respect to being "wet" by the other phase. Inferences about grain growth, coarsening, and evolving morphology are obtained from the integrated curvature of the bounding surface of a grain, which depends on the number and phase of neighboring grains, as well as the order of their arrangement. Under some conditions, a dispersion of second phase grains grain boundaries will tend to a uniform size; this second phase resists coarsening. RP CAHN, JW (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 17 TC 43 Z9 43 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD OCT PY 1991 VL 39 IS 10 BP 2189 EP 2199 DI 10.1016/0956-7151(91)90001-H PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GF315 UT WOS:A1991GF31500001 ER PT J AU RUMBLE, J AF RUMBLE, J TI THE STANDARD REFERENCE DATABASE SO AMERICAN LABORATORY LA English DT Database Review RP RUMBLE, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD OCT PY 1991 VL 23 IS 15 BP 48 EP 48 PG 1 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA GJ874 UT WOS:A1991GJ87400007 ER PT J AU RAMMACHER, W CUNTZ, M AF RAMMACHER, W CUNTZ, M TI EFFECTS OF MG II AND CA II IONIZATION ON ABINITIO SOLAR CHROMOSPHERE MODELS SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE HYDRODYNAMICS; RADIATION TRANSFER; SHOCK WAVES; SUN, CHROMOSPHERE OF ID ACOUSTIC-WAVES; ATMOSPHERE; EMISSION; TIME AB We compute acoustically heated solar chromosphere models considering radiation damping by (non-LTE) emission from H- and by Mg II and Ca II emission lines. The radiative transfer equations for the Mg II k and Ca II K emission lines are solved using the core-saturation method with complete redistribution. The Mg II k and Ca II K cooling rates are compared with the VAL model C. We include several substantial improvements over the work of Ulmschneider et al. (1987). First, we remove the dependency of the results from the core-wing separation points by improving the frequency integration method. Second, we treat the ionization equilibria of Mg II-III and Ca II-III in a non-LTE approximation using a two-level atom (instead of LTE). We find that the rapid temperature rises caused by the ionization of Mg II are not formed in the middle chromosphere, but occur at larger atmospheric heights. Our models represent the temperature structure of the "real" solar chromosphere much better. This result is a major precondition for the study of ab-initio models for solar flux tubes based on MHD wave propagation and also for ab-initio models for the solar transition layer. We have checked the dependence of our results on the radiative transfer method by comparing our computations with those using the operator perturbation method of Kalkofen (1984) and those using the method of Carlsson (1986), which combines complete linearization techniques with approximate lambda operators. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RP UNIV HEIDELBERG, INST THEORET ASTROPHYS, W-6900 HEIDELBERG, GERMANY. NR 29 TC 7 Z9 7 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 1991 VL 250 IS 1 BP 212 EP 219 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GK744 UT WOS:A1991GK74400024 ER PT J AU DING, L MCCRAY, R AF DING, L MCCRAY, R TI THE CIRCUMSTELLAR SHELL OF SN-1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; NEBULAE INDIVIDUAL (SN-1987A); STARS CIRCUMSTELLAR SHELLS; STARS SUPERNOVAE ID PLANETARY-NEBULAE; EMISSION-LINES; EVOLUTION; REMNANT AB An hourglass-shaped circumstellar shell, with radius approximately 0.65 lt-yr at the equator and approximately 2.4 lt-yr at the poles, surrounds SN 1987A. The shell is a bubble blown by the wind of the blue giant progenitor of SN 1987A into an equatorially concentrated wind of a prior red giant stage. The bubble was ionized by the initial UV flash of the supernova, and the emission-line region is concentrated in a ring at the waist of the hourglass. In ca. A.D. 2002 the supernova envelope will strike the shell. The resulting young supernova remnant will become a luminous (approximately 10(38) ergs s-1) source of soft X-rays and broad optical and ultraviolet emission lines. RP DING, L (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,CAMPUS BOX 440,BOULDER,CO 80309, USA. NR 32 TC 0 Z9 0 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 OCT 1 PY 1991 VL 379 IS 2 BP 659 EP 662 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GH078 UT WOS:A1991GH07800021 ER PT J AU KAIMAL, JC KRISTENSEN, L AF KAIMAL, JC KRISTENSEN, L TI TIME-SERIES TAPERING FOR SHORT DATA SAMPLES SO BOUNDARY-LAYER METEOROLOGY LA English DT Note ID ATMOSPHERIC SPECTRA AB We explore the effect of applying tapered windows on atmospheric data to eliminate overestimation inherent in spectra computed from short time series. Some windows are more effective than others in correcting this distortion. The Hamming window gave the best results with experimental data. The Hanning window, which performed almost as well with the same data set, was used to demonstrate the effectiveness of the window in a numerical simulation of the process. We recommend that either of these windows be applied to short data samples prior to spectral analysis. C1 RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. RP KAIMAL, JC (reprint author), NOAA,ERL,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 6 TC 17 Z9 20 U1 4 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD OCT PY 1991 VL 57 IS 1-2 BP 187 EP 194 DI 10.1007/BF00119719 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH164 UT WOS:A1991GH16400009 ER PT J AU MAHAPATRA, PR DOVIAK, RJ ZRNIC, DS AF MAHAPATRA, PR DOVIAK, RJ ZRNIC, DS TI MULTISENSOR OBSERVATION OF AN ATMOSPHERIC UNDULAR BORE SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GRAVITY-WAVES; SOLITARY WAVE AB A detailed and unique multisensor observation of an undular bore is presented. The data include those from rawinsonde, satellite, two Doppler radars, and a tall instrumented tower. Noteworthy are Doppler radar images that resolve the wave's characteristics and capture a good part of its spatial extent. The basic parameters of the wave train are established from the observations. C1 NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP MAHAPATRA, PR (reprint author), INDIAN INST SCI,DEPT AEROSP ENGN,BANGALORE 560012,KARNATAKA,INDIA. NR 25 TC 25 Z9 25 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1991 VL 72 IS 10 BP 1468 EP 1480 DI 10.1175/1520-0477(1991)072<1468:MOOAAU>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL845 UT WOS:A1991GL84500001 ER PT J AU ELLIOTT, WP GAFFEN, DJ AF ELLIOTT, WP GAFFEN, DJ TI ON THE UTILITY OF RADIOSONDE HUMIDITY ARCHIVES FOR CLIMATE STUDIES SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VAPOR-PRESSURE; ICE AB This paper considers the use of upper-air data from radiosondes in long-term climate studies. The accuracy and precision of radiosonde humidity measurements, including temperature and pressure measurements used in calculating them, and their effects on the precision of reported and derived variables are estimated. Focusing on the U.S. radiosonde system, we outline the history of changes in instruments and reporting practices and attempt to assess the implications of such changes for studies of temporal variations in lower-tropospheric water vapor. Changes in biases in the data are highlighted, as these can lead to misinterpretation of climate change. We conclude that the upper-air data record for the United States is not homogeneous, especially before 1973. Because of problems with the humidity data in cold, dry conditions, the water vapor climatology in the upper troposphere, nominally above the 500-mb level, is not well known. RP ELLIOTT, WP (reprint author), NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910, USA. NR 36 TC 308 Z9 313 U1 2 U2 12 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 OCT PY 1991 VL 72 IS 10 BP 1507 EP 1520 DI 10.1175/1520-0477(1991)072<1507:OTUORH>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL845 UT WOS:A1991GL84500003 ER PT J AU MENZEL, WP CHEDIN, A AF MENZEL, WP CHEDIN, A TI SUMMARY OF THE 6TH INTERNATIONAL TOVS STUDY CONFERENCE SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB The Sixth International TIROS Operational Vertical Sounder(TOVS) Study Conference (ITSC-VI) was held in Airlie, Virginia, from 1-6 May 1991. The International TOVS Study Conferences (ITSC) continue to be held at approximately 18-month intervals. Since 1983 this Working Group of the International Radiation Commission has been convening users of the NOAA polar-orbiting satellite data to compare performance of schemes for retrieving thermodynamic properties of the atmosphere (such as temperature and moisture), to undertake case studies of the impact of soundings on numerical weather-prediction models, to define important directions for further research, and to formulate recommendations to the World Meteorological Organization. A summary and the recommendations of this conference are reported here. C1 ECOLE POLYTECH,METEROL DYNAM LAB,F-91128 PALAISEAU,FRANCE. RP MENZEL, WP (reprint author), UNIV WISCONSIN,COOPERAT INST METEROL SATELLITE STUDIES,NOAA,MADISON,WI 53706, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1991 VL 72 IS 10 BP 1543 EP 1545 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL845 UT WOS:A1991GL84500007 ER PT J AU KARLICKY, M SMITH, Z DRYER, M AF KARLICKY, M SMITH, Z DRYER, M TI COMPARISON OF 2-DIMENSIONAL MHD AND SEMIEMPIRICAL MODELS OF INTERPLANETARY SHOCK-WAVE PROPAGATION SO BULLETIN OF THE ASTRONOMICAL INSTITUTES OF CZECHOSLOVAKIA LA English DT Article DE SHOCK WAVE PROPAGATION; MODEL; SEMIEMPIRICAL; MAGNETOHYDRODYNAMIC; SHOCK WAVE; E-W ASYMMETRY ID FLARE-ASSOCIATED DISTURBANCES; SOLAR-WIND; SIMULATION AB Shock wave velocities at 126 points in the solar equatorial plane, within 1 AU, are obtained from a 2-D magnetohydrodynamic model (Wu et al. 1983). These simulations are compared with those from a semi-empirical model of shock wave propagation by Voros and Karlicky (1989). Shocks with the three different initial velocities, upsilon(s) = 1000, 1500 and 2000 km s-1, were considered. Although agreement in the exponential dependence (N congruent-to 0.5) of shock wave velocities (upsilon(s) is-proportional-to 1/R(N)) was found, the two models differ: a) in the early stages of shock wave propagation, and b) in the shock shapes. A small E-W asymmetry of shock wave propagation was found in the MHD simulations. C1 NOAA,ERL,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP KARLICKY, M (reprint author), CZECHOSLOVAK ACAD SCI,INST ASTRON,CS-25165 ONDREJOV,CZECHOSLOVAKIA. RI Karlicky, Marian/G-9023-2014; xue, yansheng/A-9712-2012 NR 14 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIA PI PRAGUE 1 PA PUBL HOUSE CZECH ACAD SCI VODICKOVA 40, PRAGUE 1, CZECH REPUBLIC 112 29 SN 0004-6248 J9 B ASTRON I CZECH PD OCT PY 1991 VL 42 IS 5 BP 320 EP 328 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GV026 UT WOS:A1991GV02600008 ER PT J AU SNAY, RA NEUGEBAUER, HC PRESCOTT, WH AF SNAY, RA NEUGEBAUER, HC PRESCOTT, WH TI HORIZONTAL DEFORMATION ASSOCIATED WITH THE LOMA-PRIETA EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID CALIFORNIA AB Co-seismic horizontal displacements for the 1989 Loma Prieta earthquake were derived from preseismic triangulation/trilateration observations and postseismic GPS observations. As part of this process, the empirical model entitled TDP-H91 was applied to "correct" the preseismic measurements for the crustal motion that occurred during the seven decades spanned by these data. These newly derived displacements were combined with previously documented geodetic results to generate a dislocation model for the earthquake. Our preferred model consists of a vertically segmented rupture surface represented by two rectangles that share a common edge at a depth of 9 km. The upper rectangle dips 90-degrees and the lower rectangle dips 70-degrees-SW. Via a trial-and-error technique, the following estimates were found for the remaining parameters: strike = 134.4 +/- 0.7-degrees, fault length = 32.4 +/- 0.7 km, upper depth = 4.8 +/- 0.1 km, lower depth = 15.1 +/- 0.3 km, right-lateral strike slip = 1.86 +/- 0.06 m for the upper rectangle and 1.96 +/- 0.13 m for the lower rectangle, and thrusting dip slip = 1.06 +/- 0.06 m for the upper rectangle and 2.30 +/- 0.18 m for the lower rectangle. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP SNAY, RA (reprint author), NATL GEODECT SURVEY,NCG113,11400 ROCKVILLE PIKE,ROCKVILLE,MD 20852, USA. NR 12 TC 16 Z9 19 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1991 VL 81 IS 5 BP 1647 EP 1659 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GQ003 UT WOS:A1991GQ00300010 ER PT J AU WILSON, JW GIORGI, AE STUEHRENBERG, LC AF WILSON, JW GIORGI, AE STUEHRENBERG, LC TI A METHOD FOR ESTIMATING SPILL EFFECTIVENESS FOR PASSING JUVENILE SALMON AND ITS APPLICATION AT LOWER GRANITE DAM ON THE SNAKE RIVER SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article AB Juvenile salmonids migrating down the Snake and Columbia rivers in the northwestern United States pass each of the rivers' hydroelectric dams via either the powerhouse or the spillway. Spill effectiveness, the proportion of juveniles passing through the dam via the spillway, is important to fishery managers seeking to minimize the exposure of fish to turbines. We outline a method for estimating spill effectiveness and its sampling variance using a multinomial model with categories defined on the basis of information recovered from radio tagged fish. We applied this method to data from tagged chinook salmon (Oncorhynchus tshawytscha) juveniles released at Lower Granite Dam in 1985. For two release conditions, one with 20 and the other with 40% of the total water volume going through the spillway, the maximum likelihood estimates of spill effectiveness were 41 and 61%, respectively. Increasing the flow of water through spillways may therefore be a useful method of increasing spill passage of juvenile salmonids at Lower Granite Dam. Similar radio tag experiments and multinomial models could readily be devised to study spill effectiveness at hydroelectric projects with a wide variety of structural plans. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. NR 14 TC 14 Z9 15 U1 1 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 1991 VL 48 IS 10 BP 1872 EP 1876 DI 10.1139/f91-221 PG 5 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GL814 UT WOS:A1991GL81400007 ER PT J AU GORDOA, A HIGHTOWER, JE AF GORDOA, A HIGHTOWER, JE TI CHANGES IN CATCHABILITY IN A BOTTOM-TRAWL FISHERY FOR CAPE HAKE (MERLUCCIUS-CAPENSIS) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID BENGUELA ECOSYSTEM; ABUNDANCE; DENSITY AB Management of the Cape hake (Merluccius capensis) stock off the coasts of Angola and Namibia has been based on surplus production modeling, which incorporates an assumption of constant catchability. Results of least-squares catch-at-age analysis and virtual population analysis were used to estimate catchability from 1968 to 1986. Estimated catchability was either relatively constant or gradually increasing from 1968 to 1978, but fluctuated considerably between about 1979 and 1983. The fluctuations may have been due to an inverse relationship between catchability and abundance or to environmental factors affecting fish distribution. The period of highest estimated catchability corresponded to the period of lowest estimated abundance and below-average water temperatures. If management is based on the assumption of constant catchability but catchability is inversely related to abundance, the risk of overfishing will be greatest when the stock is at the lowest levels. Future assessments should place increased reliance on survey data or incorporate an appropriate model of catchability changes. C1 SW FISHERIES SCI CTR,TIBURON LAB,TIBURON,CA 94920. RP GORDOA, A (reprint author), INST CIENCIAS DEL MAR,PASEO NACL,E-08039 BARCELONA,SPAIN. RI Gordoa, Ana/A-1470-2013 OI Gordoa, Ana/0000-0003-1822-8196 NR 34 TC 22 Z9 22 U1 0 U2 1 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 1991 VL 48 IS 10 BP 1887 EP 1895 DI 10.1139/f91-224 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GL814 UT WOS:A1991GL81400010 ER PT J AU MANDEL, J AF MANDEL, J TI THE VALIDATION OF MEASUREMENT THROUGH INTERLABORATORY STUDIES SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Article AB The problem of interlaboratory tests has been investigated with regard to its principal aspects: planning of experiments, analysis of numerical data, treatment of questionable data, and possible models. The discussion is illustrated by means of a real numerical example, comprising 18 laboratories, 5 materials, and duplicate measurements in each of the 90 cells. RP MANDEL, J (reprint author), NATL INST STAND & TECHNOL,NATL MEASUREMENT LAB,GAITHERSBURG,MD 20899, USA. NR 7 TC 27 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD OCT PY 1991 VL 11 IS 2 BP 109 EP 119 DI 10.1016/0169-7439(91)80058-X PG 11 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA GN731 UT WOS:A1991GN73100001 ER PT J AU SPIEGELMAN, CH WATTERS, RL HUNGWU, L AF SPIEGELMAN, CH WATTERS, RL HUNGWU, L TI A STATISTICAL-METHOD FOR CALIBRATING FLAME EMISSION-SPECTROMETRY WHICH TAKES ACCOUNT OF ERRORS IN THE CALIBRATION STANDARDS SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Article AB The determination of potassium in sample solutions using flame emission spectrometry (FES) requires that the calibration function be estimated. Calibration standard solutions of potassium are made in the laboratory and nebulized into the FES instrument. A total of 240 data points were collected from chemical analyses. However the data come from only eight different values of the standards and are highly correlated within each standard. In the final analysis a sample size of eight was chosen to estimate the calibration curve. The main goal of this paper is to estimate the calibration function based, on these data and then measure the amount of potassium in samples using this calibration function. The secondary goal is to show some of the important exploratory data analysis that should be done in any calibration. Since both the underlying theory of emission spectrometry and the scatter plot of data points suggest a linear relationship between the emission intensity and potassium concentration, a linear regression model is applied to fit these data and the residuals are examined based on regression assumptions. Data transformation is then attempted to stabilize the nonconstant variance of the residuals due to the fact that residuals fail to meet the assumptions. However, because the suggested transformation of taking the logarithm or 1/4 power of both x and y is hard to interpret, and because the log transformation would require an addition of an arbitrary constant to the standard values, we proceeded with the untransformed data. Outlier detection was used to find possible outliers. Ten consecutive observations (obs. 201-210) in the data set are potential outliers for they have absolute studentized residuals bigger than 2.7. However, influential observation techniques indicate that their effect on the estimation of the calibration curve is not great. In order to help compensate for the error in the calibration standards, we expand the calibration interval estimates. This compensation is important and helps to avoid the rather ad-hoc deletion of unusually influential data from the analysis. We think that a plausible explanation for the outliers is error in the calibration standards. In recognition of the heterogeneity of variance indicated by our data, we perform a weighted least squares type of confidence interval estimation for our calibration curve. The coefficient and standard error estimates are quite close for all weighted cases; in contrast, the unweighted case yields different values for the standard errors. If heteroscedasticity (nonconstant variance of the observations) is ignored, confidence intervals will be too wide at the low end and too narrow at the high end of the calibration curve. At both ends of the calibration curve, each resulting multiple-use calibration confidence interval is somewhat wider than the corresponding single-use calibration confidence interval. Finally, since the measurement errors that have a known finite bound in working standards have been taken into account, the increase in confidence intervals relative to presumed exact standards is about 0.1%. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP SPIEGELMAN, CH (reprint author), TEXAS A&M UNIV SYST,DEPT STAT,COLLEGE STN,TX 77843, USA. NR 9 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD OCT PY 1991 VL 11 IS 2 BP 121 EP 130 DI 10.1016/0169-7439(91)80059-Y PG 10 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA GN731 UT WOS:A1991GN73100002 ER PT J AU BIGFORD, TE AF BIGFORD, TE TI SEA-LEVEL RISE, NEARSHORE FISHERIES, AND THE FISHING INDUSTRY SO COASTAL MANAGEMENT LA English DT Article DE FISHERIES; COASTAL MANAGEMENT; FISHERY MANAGEMENT; SEA-LEVEL CHANGE; HABITAT; COASTAL DEVELOPMENT AB Global meteorological conditions may be changing, and sea levels over the next centuries could rise at rates usually measured over millennia. As a result, fish habitats, fishery yields, and the industry's shoreside infrastructure could change dramatically. This article (1) summarizes predicted sea-level changes; (2) forecasts possible short- and long-term effects on fish habitats, valued estuarine and coastal species, and fishing industry sectors; and (3) recommends specific actions to maintain a viable fishing industry. Lacking applicable research results, most effects are extrapolated from professional opinions and related research on other coastal industries or features. Emphasis is on the United States' Atlantic Coast. Predicted impacts should change over time. Some short-term changes could be beneficial as new habitats are created for estuarine species, but the long-term implications on most sectors, especially shoreside industries, are more negative than positive. Potential impacts should inspire harvesting and processing sectors to participate in remedial planning, where assistance is available from coastal managers. Recommendations address deficiencies in natural resource management strategies, development policies, short- and long-term waterfront plans, decision-making protocols for actions such as wetland permits, and priorities for remedial action. RP BIGFORD, TE (reprint author), NOAA,NATL MARINE FISHERIES SERV,1 BLACKBURN DR,GLOUCESTER,MA 01930, USA. NR 0 TC 6 Z9 6 U1 1 U2 4 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0892-0753 J9 COAST MANAGE JI Coast. Manage. PD OCT-DEC PY 1991 VL 19 IS 4 BP 417 EP 437 DI 10.1080/08920759109362152 PG 21 WC Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology GA GR504 UT WOS:A1991GR50400002 ER PT J AU ZACHARIAH, MR HUZAREWICZ, S AF ZACHARIAH, MR HUZAREWICZ, S TI FLAME SYNTHESIS OF HIGH-TC SUPERCONDUCTORS SO COMBUSTION AND FLAME LA English DT Article AB High-temperature superconducting particles of the 1:2:3 yttrium-barium-copper oxide systems were synthesized in an inverted configuration coannular diffusion flame. The particles were produced from a spray pyrolysis technique, employing aerosolized nitrate salts of Y, Ba, and Cu. The product showed a transition temperature of 92 K as determined from magnetic susceptibility measurements. The particles were shown to have a wide size distribution, ranging from 10 to 1000 nm. Due to the effects of water vapor reactions at high temperatures, only a diffusion flame successfully produced the correct phase. RP ZACHARIAH, MR (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 5 TC 13 Z9 13 U1 0 U2 7 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 OCT PY 1991 VL 87 IS 1 BP 100 EP 103 DI 10.1016/0010-2180(91)90030-F PG 4 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA GL804 UT WOS:A1991GL80400009 ER PT J AU DANEY, DE AF DANEY, DE TI REGENERATOR PERFORMANCE WITH NOBLE-GAS MIXTURES SO CRYOGENICS LA English DT Article DE REGENERATORS; NOBLE GASES; HELIUM AB The performance of regenerators that use noble gas mixtures is compared to the performance of those that use pure helium gas. Both helium - argon and helium - krypton mixtures are investigated. For some heat transfer surfaces, a modest gain in heat transfer can be achieved with these mixtures. The concomitant increase in pressure drop, however, more than offsets the heat transfer gain, so that the net regenerator loss increases for all the cases evaluated. RP DANEY, DE (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 18 TC 2 Z9 2 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD OCT PY 1991 VL 31 IS 10 BP 854 EP 861 DI 10.1016/0011-2275(91)90017-Q PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA GG044 UT WOS:A1991GG04400001 ER PT J AU ARKIN, P JANOWIAK, J AF ARKIN, P JANOWIAK, J TI ANALYSES OF THE GLOBAL DISTRIBUTION OF PRECIPITATION SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article ID CLOUD; 30-DEGREES-S; RAINFALL; OCEAN AB The global distribution of area-averaged precipitation is extremely difficult to determine with precision. In this paper we will explain why satellite measurements are necessary for the production of global analyses of precipitation, summarize some of the various methods which have been used to estimate rainfall from satellite observations over the past two decades, and describe an attempt to use a mix of remotely sensed estimates and surface observations of rainfall to produce analyses of the large-scale rainfall for the globe. We will discuss the relationship between two types of satellite-derived precipitation estimates over the oceans from 40-degrees-N to 40-degrees-S, and then will conclude with a discussion of some possible physical mechanisms which might be responsible for the observed correlation between area-averaged rainfall and cloudiness. C1 NOAA,CTR CLIMATE ANAL,SILVER SPRING,MD 20910. RP ARKIN, P (reprint author), NOAA,OFF GLOBAL PROGRAMS,SILVER SPRING,MD 20910, USA. RI Arkin, Phillip/F-5808-2010 NR 13 TC 14 Z9 15 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD OCT PY 1991 VL 16 IS 1-2 BP 5 EP 16 DI 10.1016/0377-0265(91)90009-5 PG 12 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA GP975 UT WOS:A1991GP97500003 ER PT J AU GERRODETTE, T AF GERRODETTE, T TI MODELS FOR POWER OF DETECTING TRENDS - A REPLY SO ECOLOGY LA English DT Letter RP GERRODETTE, T (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 9 TC 34 Z9 35 U1 1 U2 1 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD OCT PY 1991 VL 72 IS 5 BP 1889 EP 1892 DI 10.2307/1940986 PG 4 WC Ecology SC Environmental Sciences & Ecology GA GK823 UT WOS:A1991GK82300034 ER PT J AU WISE, SA BENNER, BA CHRISTENSEN, RG KOSTER, BJ KURZ, J SCHANTZ, MM ZEISLER, R AF WISE, SA BENNER, BA CHRISTENSEN, RG KOSTER, BJ KURZ, J SCHANTZ, MM ZEISLER, R TI PREPARATION AND ANALYSIS OF A FROZEN MUSSEL TISSUE REFERENCE MATERIAL FOR THE DETERMINATION OF TRACE ORGANIC-CONSTITUENTS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; LIQUID-CHROMATOGRAPHIC DETERMINATION; ENVIRONMENTAL-SAMPLES AB A new mussel tissue Standard Reference Material (SRM) has been prepared and analyzed for trace organic and inorganic constituents. SRM 1974 [Organics in Mussel Tissue (Mytilus edulis)] is a frozen mussel tissue homogenate that has been certified for the concentrations of nine polycyclic aromatic hydrocarbons (PAHs) from results obtained from gas chromatography-mass spectrometry and reversed-phase liquid chromatography with fluorescence detection. Noncertified concentrations for 19 additional PAHs are also reported. Gas chromatography with electron capture detection and gas chromatography with mass spectrometric detection were used to provide noncertified concentrations for 13 polychlorinated biphenyl congeners and 9 chlorinated pesticides. In addition to the organic contaminants, noncertified concentrations for 36 trace elements were determined primarily by instrumental neutron activation analysis. SRM 1974 is the first frozen tissue SRM for environmental measurements of organic and inorganic constituents. C1 UNIV ULM,DEPT ANALYT & ENVIRONM CHEM,W-7900 ULM,GERMANY. RP WISE, SA (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 36 TC 58 Z9 58 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1991 VL 25 IS 10 BP 1695 EP 1704 DI 10.1021/es00022a003 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GH491 UT WOS:A1991GH49100007 ER PT J AU ZDANOWICZ, VS AF ZDANOWICZ, VS TI DETERMINING THE FATES OF CONTAMINATED WASTES DUMPED IN THE NEW-YORK BIGHT APEX BY USE OF METAL ENRICHMENT FACTORS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOUTHERN-CALIFORNIA; RIVER ESTUARY; HEAVY-METALS; SANTA-MONICA; SEDIMENTS; POLLUTION; HISTORY AB The major sources of contaminants to the New York Bight apex in 1983 were sewage sludge and dredged spoils dumping and the outflow of the Hudson-Raritan estuary. Metal distributions were determined in sediments collected during a 1983 survey and metal enrichment factors, based on ratios of trace metals to iron, were used to distinguish fates of sewage sludge and dredged spoils dumped in the Bight apex. Lead enrichment factors indicated that the portion of the apex that was directly affected by dredged spoils dumping was in the immediate vicinity of that site, even though this activity constituted the largest source of solid materials to the apex. Sewage sludge dumping, in contrast, while contributing much less total mass than dredged spoils dumping, appeared to directly affect approximately 8 times as much area. RP ZDANOWICZ, VS (reprint author), NOAA,NATL MARINE FISHERIES SERV,SANDY HOOK LAB,HIGHLANDS,NJ 07732, USA. NR 40 TC 9 Z9 9 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1991 VL 25 IS 10 BP 1760 EP 1766 DI 10.1021/es00022a013 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GH491 UT WOS:A1991GH49100017 ER PT J AU ANDERSON, PJ AF ANDERSON, PJ TI AGE, GROWTH, AND MORTALITY OF THE NORTHERN SHRIMP PANDALUS-BOREALIS KROYER IN PAVLOF BAY, ALASKA SO FISHERY BULLETIN LA English DT Article ID POPULATION FLUCTUATIONS; OCEAN AB Northern shrimp Pandalus borealis carapace length-frequency data collected from shrimp surveys and commercial catches between 1972 and 1986 were studied to estimate age, growth, and mortality in Pavlof Bay, Alaska. Dominant size modes representing 1971 and 1975 year-classes were separated from carapace length-frequency distributions by the use of a maximum-likelihood separation technique. The growth rate for the 1975 year-class was significantly greater than that of the 1971 year-class. Because the abundance of the 1975 year-class was lower than that of the 1971 year-class, an inverse relationship of growth to year-class strength was suggested. Age-at-sex transition appears to be related to year-class abundance or overall density as 1975 year-class shrimp completed transition at a younger age than that of 1971. Increases in natural mortality occurred after the 1971 year-class completed transformation to the female sex at age 6.4, and may indicate a combination of spawning stress and senescence or increasing abundance of the predator, Pacific cod Gadus macrocephalus. Dynamic pool yield-per-recruit analysis indicated maximum biomass of year-classes was achieved at or prior to full recruitment to the survey and commercial fishing gear. Because mortality rates are high, yield-per-recruit is optimized by harvesting more of the smaller male shrimp. RP ANDERSON, PJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,KODIAK LAB,POB 1638,KODIAK,AK 99615, USA. NR 44 TC 19 Z9 19 U1 0 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 541 EP 553 PG 13 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000001 ER PT J AU BOGGS, CH AF BOGGS, CH TI BIOENERGETICS AND GROWTH OF NORTHERN ANCHOVY ENGRAULIS-MORDAX SO FISHERY BULLETIN LA English DT Article ID FILTER-FEEDING PLANKTIVORE; BREVOORTIA-TYRANNUS PISCES; ATLANTIC MENHADEN; ENERGY; ENERGETICS; CONSUMPTION; CLUPEIDAE; RATION; SIZE; FISH AB Changes in total body energy content of adult (total length approximately 9 cm, wet mass approximately 9 g) northern anchovy Engraulis mordax were estimated by sampling captive groups swimming at 8.7 and 21.1 cm/s for 12 hours daily. Anchovy were fed euphausiids at rations of 5 and 3.4% of fish wet mass per day (approximately 54 and 37 cal . g fish wet mass-1 . day-1, respectively). Gross energy conversion efficiency increased with ration levels and declined with swimming speed, ranging from 39% to 1%. Dry mass and lipid losses were estimated in fasting fish swimming at the same speeds. Energy losses were 17.6 and 28.2 cal . g fish wet mass-1 . day-1 at the slow and fast speeds, respectively. The proportion of food energy used for growth and maintenance metabolism was about 65%. A model derived for adult anchovy metabolism was consistent with observed growth and reproduction rates, and the few measurements of ration and swimming speed in nature. RP BOGGS, CH (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 32 TC 9 Z9 9 U1 1 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 555 EP 566 PG 12 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000002 ER PT J AU LAIDIG, TE RALSTON, S BENCE, JR AF LAIDIG, TE RALSTON, S BENCE, JR TI DYNAMICS OF GROWTH IN THE EARLY LIFE-HISTORY OF SHORTBELLY ROCKFISH SEBASTES-JORDANI SO FISHERY BULLETIN LA English DT Article ID PLATICHTHYS-STELLATUS; ANOPLOPOMA-FIMBRIA; BACK-CALCULATION; STARRY FLOUNDER; SIZE SELECTION; MARINE FISHES; OTOLITHS; LARVAL; INCREMENTS; PATTERNS AB The relationship between length and age of larval and juvenile shortbelly rockfish Sebastes jordani, determined from otolith microstructure, is complex. Models that assume size increases smoothly with age may not accurately describe growth in young-of-the-year rockfish. A segmented (piece-wise linear) regression model relating somatic and otolith size was used to back-calculate body length-at-age. The segments of this model coincide with different growth stanzas, which are separated by distinct life-history transitions. The composite function of this model, and a Gompertz curve relating otolith size and age, yielded a good fit to the back-calculated standard length-at-age data. Comparison of back-calculated with actual growth showed no evidence of size-selective mortality. The change in body length, as the number of otolith increments increased, was equal to the observed increase in length per day of a sequentially sampled cohort, validating the daily periodicity of the increments. RP LAIDIG, TE (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. RI Bence, James/E-5057-2017 OI Bence, James/0000-0002-2534-688X NR 55 TC 49 Z9 52 U1 1 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 611 EP 621 PG 11 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000006 ER PT J AU BOOMAN, C FOLKVORD, A HUNTER, JR AF BOOMAN, C FOLKVORD, A HUNTER, JR TI RESPONSIVENESS OF STARVED NORTHERN ANCHOVY ENGRAULIS-MORDAX LARVAE TO PREDATORY ATTACKS BY ADULT ANCHOVY SO FISHERY BULLETIN LA English DT Note ID CHANOS-CHANOS FORSSKAL; STARVATION; LIVER; VULNERABILITY; FISHES C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,LA JOLLA,CA 92038. RP BOOMAN, C (reprint author), UNIV BERGEN,ZOOL LAB,ALLEGATE 45,N-5007 BERGEN,NORWAY. OI Folkvord, Arild/0000-0002-4763-0590 NR 21 TC 19 Z9 19 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 707 EP 711 PG 5 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000015 ER PT J AU CAILLOUET, CW DURONSLET, MJ LANDRY, AM REVERA, DB SHAVER, DJ STANLEY, KM HEINLY, RW STABENAU, EK AF CAILLOUET, CW DURONSLET, MJ LANDRY, AM REVERA, DB SHAVER, DJ STANLEY, KM HEINLY, RW STABENAU, EK TI SEA-TURTLE STRANDINGS AND SHRIMP FISHING EFFORT IN THE NORTHWESTERN GULF OF MEXICO, 1986-89 SO FISHERY BULLETIN LA English DT Note ID LEPIDOCHELYS-KEMPI; CARETTA-CARETTA; UNITED-STATES; LOGGERHEAD; RIDLEY C1 TEXAS A&M UNIV SYST,DEPT MARINE BIOL,GALVESTON,TX 77553. US DEPT INTERIOR,NATL PK SERV,PADRE ISLAND NATL SEASHORE,CORPUS CHRISTI,TX 78418. RP CAILLOUET, CW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,GALVESTON LAB,GALVESTON,TX 77551, USA. NR 30 TC 22 Z9 23 U1 0 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 712 EP 718 PG 7 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000016 ER PT J AU OVERHOLTZ, WJ WARING, GT AF OVERHOLTZ, WJ WARING, GT TI DIET COMPOSITION OF PILOT WHALES GLOBICEPHALA SP AND COMMON DOLPHINS DELPHINUS-DELPHIS IN THE MID-ATLANTIC BIGHT DURING SPRING 1989 SO FISHERY BULLETIN LA English DT Note ID AMMODYTES-AMERICANUS; HUMPBACK WHALE; FOOD SELECTION; LINEAR INDEX RP OVERHOLTZ, WJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 21 TC 27 Z9 28 U1 1 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 723 EP 728 PG 6 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000018 ER PT J AU SUTTER, FC WILLIAMS, RO GODCHARLES, MF AF SUTTER, FC WILLIAMS, RO GODCHARLES, MF TI GROWTH AND MORTALITY OF KING MACKEREL SCOMBEROMORUS-CAVALLA TAGGED IN THE SOUTHEASTERN UNITED-STATES SO FISHERY BULLETIN LA English DT Note ID AGE; LOUISIANA C1 FLORIDA MARINE FISHERIES COMMISS,TALLAHASSEE,FL 32301. NOAA,NATL MARINE FISHERIES SERV,SE REG,ST PETERSBURG,FL 33702. RP SUTTER, FC (reprint author), FLORIDA MARINE RES INST,DEPT NAT RESOURCES,100 8TH AVE SE,ST PETERSBURG,FL 33701, USA. NR 14 TC 6 Z9 6 U1 0 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1991 VL 89 IS 4 BP 733 EP 737 PG 5 WC Fisheries SC Fisheries GA GU460 UT WOS:A1991GU46000020 ER PT J AU CALHOUN, JA BATES, TS CHARLSON, RJ AF CALHOUN, JA BATES, TS CHARLSON, RJ TI SULFUR ISOTOPE MEASUREMENTS OF SUBMICROMETER SULFATE AEROSOL-PARTICLES OVER THE PACIFIC-OCEAN SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC SULFUR; CLOUD ALBEDO; DIOXIDE; CLIMATE; DIMETHYLSULFIDE; PHYTOPLANKTON; MECHANISM; CYCLE; IONS AB The climatic importance of atmospheric submicrometer sulfate aerosol particles necessitates a thorough understanding of the various sources of sulfur to the marine atmosphere [Charlson et al., 1987; Coakley et al., 1987; Charlson et al., 1990]. Over the remote ocean, the primary source of atmospheric non-seasalt (NSS) sulfate is thought to be marine emissions of dimethylsulfide (DMS) [Charlson et al., 1987]. Here we report the results of a study which used stable sulfur isotopes to test this hypothesis. NSS sulfate in submicrometer aerosol particles over remote parts of the South Pacific Ocean had an average delta-S-34 value of +15.6 +/- 3.1 part-per thousand, relative to the Canyon Diablo standard. The sulfur isotopic composition of these particles was 5.5 part-per thousand lighter than sulfate derived directly from seawater, but isotopically heavier than sulfate derived from most continental sources. This observed isotopic fractionation between seawater sulfate and NSS sulfate is consistent with the isotopic fractionation predicted for the transformation of seawater sulfate to atmospheric NSS sulfate via a DMS pathway (-1 to +7 parts per thousand) and hence supports the hypothesis that DMS can be the source of the NSS sulfate. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHER & OCEAN,SEATTLE,WA 98195. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV WASHINGTON,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. RI Bates, Timothy/L-6080-2016 NR 33 TC 85 Z9 90 U1 0 U2 13 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 OCT PY 1991 VL 18 IS 10 BP 1877 EP 1880 DI 10.1029/91GL02304 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GK002 UT WOS:A1991GK00200021 ER PT J AU APPELL, GF CURTIN, TB AF APPELL, GF CURTIN, TB TI A SPECIAL ISSUE ON CURRENT MEASUREMENT - GUEST EDITORIAL SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Editorial Material C1 OFF NAVAL RES,ARCTIC SCI,ARLINGTON,VA 22217. RP APPELL, GF (reprint author), NOAA,DIV OCEAN SYST,REMOTE ACOUST DOPPLER SYST DEV PROJECT,ROCKVILLE,MD 20852, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD OCT PY 1991 VL 16 IS 4 BP 305 EP 306 PG 2 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA GG370 UT WOS:A1991GG37000001 ER PT J AU LARSEN, JC AF LARSEN, JC TI TRANSPORT MEASUREMENTS FROM IN-SERVICE UNDERSEA TELEPHONE CABLES SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article ID FLORIDA CURRENT; ATLANTIC AB The motion of the ocean through the earth's magnetic field creates a cross-stream voltage that is proportional to the transport of the stream. These motion-induced voltages have been observed for more than ten years by the use of an abandoned cable spanning the Florida Current. In-service undersea telephone cables, including the new fiber optic cables with branch lines, can also be used to determine the motion-induced voltages between the cable sea-earth grounds because the repeaters in these cables are powered by a nearly constant electric current, the return path for this current is through the ocean via the sea-earth grounds, and the power voltage and current are readily measured at the cable station or stations. The ocean voltages between West Palm Beach, FL and Eight Mile Rock, Grand Bahama Island, observed since 1985 by use of an inservice cable, yield monthly estimates of the Florida Current transport with an rms accuracy of 1.1 Sv when compared with the monthly voltage-derived transports between Jupiter, FL and Settlement Point, Grand Bahama Island observed by the use of an abandoned cable. This corresponds to a 3% accuracy of the mean transport of 32.3 Sv. RP LARSEN, JC (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115, USA. NR 11 TC 12 Z9 12 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD OCT PY 1991 VL 16 IS 4 BP 313 EP 318 DI 10.1109/48.90893 PG 6 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA GG370 UT WOS:A1991GG37000003 ER PT J AU APPELL, GF BASS, PD METCALF, MA AF APPELL, GF BASS, PD METCALF, MA TI ACOUSTIC DOPPLER CURRENT PROFILER PERFORMANCE IN NEAR-SURFACE AND BOTTOM BOUNDARIES SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article AB This paper discusses the current measurement accuracy of the RD Instruments 1200-kHz acoustic Doppler current profiler (ADCP) in the near surface and bottom boundaries. Data are presented from tests conducted by NOAA and by RD Instruments at the Navy's David Taylor Research Center (DTRC) towing basin. In the first series of NOAA tests at DTRC, an ADCP was mounted on a bottom sled in an upward looking mode. The sled was towed at known speeds with and without surface waves. Additionally, tests were conducted with several acoustic baffle designs installed on the transducer head. The baffles were designed to improve the ADCP performance in the surface and bottom boundaries. A second and third set of tests were conducted at DTRC by NOAA and RD Instruments, respectively, with the profiler mounted on the carriage in a downward looking mode. RD Instruments also conducted beam pattern tests with and without acoustic baffles and modeled the performance of several baffle designs. Data are presented to show mean speed errors with and without waves in each bin. Performance results are presented that quantify accuracy in the boundary areas under all test conditions. Data were also collected at sufficient speed to look at wave particle velocities. An evaluation of that data is presented, as well as an evaluation of the acoustic baffle techniques to obtain undistorted measurements. C1 RD INSTRUMENTS,TECH MKT & SALES GRP,SAN DIEGO,CA 92131. RP APPELL, GF (reprint author), NOAA,DIV OCEAN SYST,REMOTE ACOUST DOPPLER SYST DEV PROJECT,ROCKVILLE,MD 20852, USA. NR 6 TC 12 Z9 12 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD OCT PY 1991 VL 16 IS 4 BP 390 EP 396 DI 10.1109/48.90903 PG 7 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA GG370 UT WOS:A1991GG37000013 ER PT J AU STEELE, KE EARLE, MD AF STEELE, KE EARLE, MD TI DIRECTIONAL OCEAN WAVE SPECTRA USING BUOY AZIMUTH, PITCH, AND ROLL DERIVED FROM MAGNETIC-FIELD COMPONENTS SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article DE OCEAN WAVES; BUOY; OCEAN WAVE SPECTRA; AND MAGNETOMETER AB Hull slopes resulting from wave motion are needed to estimate directional wave spectra from the motions of a buoy. To reduce the cost and size of onboard sensors, these slopes can be determined from measurements of the magnetic field components inside the hull along two orthogonal axes parallel to the deck of a buoy. Algorithms are developed for estimation of azimuth, pitch, and roll angles using these measurements. The algorithms account for residual and induced hull magnetism. Azimuth, pitch, and roll, as well as estimates of directional wave spectra, are determined both from the magnetic field measurements and from a conventional wave measurement system on the same buoy. Comparisons show that estimates of directional spectra based on magnetometer-derived pitch and roll agree well. C1 MEC SYST CORP,MANASSAS,VA 22110. RP STEELE, KE (reprint author), NATL DATA BUOY CTR,WAVE MEASUREMENT SYST DEV PROGRAM,STENNIS SPACE CTR,MS 39529, USA. NR 8 TC 12 Z9 14 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD OCT PY 1991 VL 16 IS 4 BP 427 EP 433 DI 10.1109/48.90909 PG 7 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA GG370 UT WOS:A1991GG37000019 ER PT J AU VANBRUNT, RJ AF VANBRUNT, RJ TI STOCHASTIC PROPERTIES OF PARTIAL-DISCHARGE PHENOMENA SO IEEE TRANSACTIONS ON ELECTRICAL INSULATION LA English DT Review ID COLLISIONAL ELECTRON DETACHMENT; PREBREAKDOWN CURRENT PULSES; INTERNAL PARTIAL DISCHARGE; PRE-BREAKDOWN PHENOMENA; NEGATIVE CORONA PULSES; NITROGEN-FILLED DIODES; POINT-PLANE CORONA; DIELECTRIC LIQUIDS; SULFUR-HEXAFLUORIDE; TRANSFORMER OIL AB Prebreakdown, pulsating, partial-discharge (PD) phenomena that occur in dielectric media are inherently complex stochastic processes that exhibit significant statistical variability in such properties as pulse amplitude, shape, and time of occurrence. Previously published work concerned with the theory and measurement of the stochastic behavior of PD is reviewed. The types of PD phenomena considered in this review include ac and dc generated electron avalanches, pulsating positive and negative corona in gases, and PD that occur in liquid media and in the presence of solid dielectric surfaces. The basic physical mechanisms of discharge initiation, growth, and memory propagation that determine the probability distributions for pulse occurrence times and pulse amplitudes are discussed. Consideration is also given to special problems associated with the measurement and interpretation of data on the various statistical properties of PD phenomena. RP NATL INST STANDARDS & TECHNOL, GAITHERSBURG, MD USA. NR 348 TC 97 Z9 99 U1 2 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9367 J9 IEEE T ELECTR INSUL PD OCT PY 1991 VL 26 IS 5 BP 902 EP 948 DI 10.1109/14.99099 PG 47 WC Engineering, Electrical & Electronic SC Engineering GA GL706 UT WOS:A1991GL70600003 ER PT J AU MCCOMB, TR LAGNESE, JE AF MCCOMB, TR LAGNESE, JE TI CALCULATING THE PARAMETERS OF FULL LIGHTNING IMPULSES USING MODEL-BASED CURVE FITTING SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article DE MODEL-BASED PARAMETER EVALUATION; CURVE-FITTING; DIGITAL SIGNAL PROCESSING; HIGH VOLTAGE IMPULSE TESTING; IMPULSE MEASUREMENTS ID ERRORS AB A brief review is presented of the techniques used for the evaluation of the parameters of high voltage impulses and the problems encountered. The determination of the best smooth curve through oscillations on a high voltage impulse is the major problem limiting the automatic processing of digital records of impulses. Non-linear regression, based on simple models, is applied to the analysis of simulated and experimental data of full lightning impulses. Results of model fitting to four different groups of impulses are presented and compared with some other methods. Plans for the extension of this work are outlined. RP MCCOMB, TR (reprint author), NATL INST STANDARDS & TECHNOL,DIV ELECT,POWER ENGN GRP,GAITHERSBURG,MD 20899, USA. NR 21 TC 14 Z9 16 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8977 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD OCT PY 1991 VL 6 IS 4 BP 1386 EP 1394 DI 10.1109/61.97668 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA GK858 UT WOS:A1991GK85800007 ER PT J AU DAVIES, K AF DAVIES, K TI REMOTE-SENSING OF THE IONOSPHERE USING SATELLITE RADIO BEACONS SO INDIAN JOURNAL OF RADIO & SPACE PHYSICS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON OPTICAL AND RADIO REMOTE SENSING OF THE ATMOSPHERIC ENVIRONMENT CY OCT 24-26, 1990 CL NEW DELHI, INDIA AB Since the launch of Sputnik I in 1957, satellite radio beacons have been used to measure the total electron content of the ionosphere. A review of the role of satellite beacons in studies of the vertical and spatial structure of the total electron content and on the occurrence of plasma irregularities, both of which affect transionospheric radio signals, is presented. Measurements of Faraday rotation and time of flight give information on the topside of the ionosphere and on the protonosphere. Morphological studies show that the slab thickness of the ionosphere depends on the solar index but is approximately independent of geographical location. Scintillation of amplitude, phase, polarization, and angle provide information on plasma irregularity occurrence in space and time. RP DAVIES, K (reprint author), NOAA,ERL,SEL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU COUNCIL SCIENTIFIC INDUSTRIAL RESEARCH PI NEW DELHI PA PUBL & INFO DIRECTORATE, NEW DELHI 110012, INDIA SN 0367-8393 J9 INDIAN J RADIO SPACE JI Indian J. Radio Space Phys. PD OCT PY 1991 VL 20 IS 5 BP 356 EP 367 PG 12 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA GK855 UT WOS:A1991GK85500008 ER PT J AU NAHOR, GS NETA, P AF NAHOR, GS NETA, P TI RATE CONSTANTS FOR REACTIONS OF PERFLUOROBUTYLPEROXYL RADICAL WITH ALKENES SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID REACTIVITY AB Perfluorobutylperoxyl radicals were produced by radiolytic reduction of perfluorobutyl iodide in aerated methanol solutions. Rate constants for the reactions of this peroxyl radical with various organic compounds were determined by kinetic spectrophotometric pulse radiolysis. The rate constants for alkanes and alkenes were determined by competition kinetics using chlorpromazine as a reference. The results indicate that hydrogen abstraction from aliphatic compounds takes place with a rate constant that is too slow to measure in our system (< 10(5) M-1 s-1), and that abstraction of allylic and doubly allylic hydrogens is slow compared with addition. Addition to alkenes takes place with rate constants of the order of k = 10(6) - 10(8) M-1 s-1. Good correlation was obtained between log k and the Taft substituent constants-sigma * for the various substituents on the double bond. Perfluorobutylperoxyl radical is found to be more reactive than trichloromethylperoxyl and other peroxyl radicals. RP NAHOR, GS (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD OCT PY 1991 VL 23 IS 10 BP 941 EP 946 DI 10.1002/kin.550231008 PG 6 WC Chemistry, Physical SC Chemistry GA GF361 UT WOS:A1991GF36100007 ER PT J AU RADFORD, HE EVENSON, KM MATUSHIMA, F ZINK, LR GALVAO, GP SEARS, TJ AF RADFORD, HE EVENSON, KM MATUSHIMA, F ZINK, LR GALVAO, GP SEARS, TJ TI FAR INFRARED-LASER FREQUENCIES OF CH3OD AND N2H4 SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE CH3OD; N2H4; MOLECULAR LASER LINES; LASER FREQUENCY MEASUREMENTS; OPTICALLY PUMPED FAR INFRARED LASERS AB The frequencies of 26 laser lines with wavelengths between 57 and 534-mu-m have been measured in the optically pumped laser gases CH3OD and N2H4. A pair of stabilized cw (CO2)-C-12 lasers was used as a frequency standard for the heterodyne frequency measurements. Seven of the 26 lines are new. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. TOYAMA UNIV,DEPT PHYS,TOYAMA 930,JAPAN. INST NACL PESQUISAS ESPACIAIS,BR-12201 SAO JOSE CAMPOS,SP,BRAZIL. RP RADFORD, HE (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,DIV ATOM & MOLEC PHYS,CAMBRIDGE,MA 02138, USA. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 5 TC 14 Z9 14 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD OCT PY 1991 VL 12 IS 10 BP 1161 EP 1166 DI 10.1007/BF01008558 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GJ575 UT WOS:A1991GJ57500005 ER PT J AU HASEGAWA, H TANAKA, H HASHIMOTO, T HAN, CC AF HASEGAWA, H TANAKA, H HASHIMOTO, T HAN, CC TI SANS AND SAXS STUDY OF BLOCK COPOLYMER HOMOPOLYMER MIXTURES SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 8TH INTERNATIONAL CONF ON SMALL ANGLE SCATTERING CY AUG 06-09, 1990 CL UNIV LOUVAIN, LOUVAIN, BELGIUM SP NATL SCI FDN BELGIUM, UNIV LOUVAIN, PHILIPS, DOW CHEM, EXXON CHEM INT, SIEMENS, SOLVAY, MAES, ICI, RAYCHEM HO UNIV LOUVAIN ID ANGLE NEUTRON-SCATTERING; MOLECULAR-CONFORMATION; MICRODOMAIN SPACE; CO-POLYMERS; ISOPRENE; STYRENE AB The lateral and vertical components of the radius of gyration for a single block copolymer chain and those of a single homopolymer chain in the lamellar microdomain space formed by a mixture of diblock copolymers and homopolymers were investigated by means of small-angle neutron scattering (SANS) and the microdomain structures by small-angle X-ray scattering (SAXS). The homopolymers whose molecular weights are much smaller than that of the corresponding chains of the block copolymers were used so that the homopolymers were uniformly solubilized in the corresponding microdomains. The SANS result suggests that the homopolymer chains in the microdomain space as well as the block copolymer chains are more compressed in the direction parallel to the interface and more stretched in the direction perpendicular to the interface than the corresponding unperturbed polymer chains with the same molecular weight. On increasing the volume fraction of the homopolymers the thickness of the lamellar microdomains increases. The block copolymer chains were found to undergo an isochoric affine deformation on addition of the homopolymers or with the change of the thickness of the lamellar microdomains. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RP HASEGAWA, H (reprint author), KYOTO UNIV,DEPT POLYMER CHEM,SAKYO KU,KYOTO 606,JAPAN. NR 15 TC 16 Z9 16 U1 0 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 1991 VL 24 BP 672 EP 678 DI 10.1107/S0021889890014212 PN 5 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA GL629 UT WOS:A1991GL62900037 ER PT J AU DRAXLER, RR AF DRAXLER, RR TI THE ACCURACY OF TRAJECTORIES DURING ANATEX CALCULATED USING DYNAMIC-MODEL ANALYSES VERSUS RAWINSONDE OBSERVATIONS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID METEOROLOGICAL DATA; RESOLUTION; TRANSPORT; SENSITIVITY; SIMULATION; CAPTEX; TRACER; WINDS AB Aircraft tracer measurements all made within 300 km of the release sites during the Across North America Tracer Experiment (ANATEX) provided 30 separate trials to evaluate the error of back-trajectory calculations. The trajectory calculations used dynamic-model-output meteorological data from the NOAA prognostic Nested Grid Model (NGM) and from comparable gridded meteorological fields from 4-day rawinsonde or 2-day rawinsonde observations. Over all trials, no significant difference was discernable in trajectory accuracy using the different meteorological input data; absolute trajectory error ranged from 20% to 30% of the travel distance. When the trajectories were grouped into similar categories, the NGM data provided the best results when smaller-scale flow features were present; ones that could not be resolved in the rawinsonde network. Four-day rawinsonde data provided the best results when fronts or low pressure systems were present in the vicinity of the tracer release. Slower transport in more homogeneous zonal flow regimes resulted in some of the smallest errors of around 15% of the travel distance for all the methods. In 70% of the events, the 4-day and 2-day rawinsonde calculations were comparable, suggesting that linear temporal interpolation of the flow field is reasonable for most situations. The primary conclusion is that the NGM-generated meteorological data can be an adequate substitute for rawinsonde data in trajectory calculations. RP DRAXLER, RR (reprint author), NOAA,AIR RESOURCES LAB R-E-AR,SSMCII,ROOM 9358,1325 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 23 TC 56 Z9 56 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 1991 VL 30 IS 10 BP 1446 EP 1467 DI 10.1175/1520-0450(1991)030<1446:TAOTDA>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GJ693 UT WOS:A1991GJ69300005 ER PT J AU DAGATA, JA TSENG, W BENNETT, J SCHNEIR, J HARARY, HH AF DAGATA, JA TSENG, W BENNETT, J SCHNEIR, J HARARY, HH TI NANOLITHOGRAPHY ON III-V-SEMICONDUCTOR SURFACES USING A SCANNING TUNNELING MICROSCOPE OPERATING IN AIR SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAAS; SILICON; OXIDE AB Nanometer-scale pattern generation on III-V semiconductor substrates using a scanning tunneling microscope (STM) operating in air is demonstrated. The sample substrates, consisting of arsenic-capped, epitaxial layers of n-doped GaAs, AlxGa1-xAs and InyGa1-yAs were prepared by molecular beam epitaxy and characterized by time-of-flight secondary-ion mass spectrometry and x-ray photoelectron spectroscopy. The direct patterning of features of width less-than-or-equal-to 50 nm on GaAs and In0.2Ga0.8As surfaces is shown to be the result of the formation of a strongly bonded surface oxide induced under high electric field conditions existing between the scan tip and the substrate. The significance of STM pattern generation of nanometer-scale oxide masks for use in the fabrication of low-dimensional heterostructures is discussed. RP DAGATA, JA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 29 Z9 29 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1991 VL 70 IS 7 BP 3661 EP 3665 DI 10.1063/1.350345 PG 5 WC Physics, Applied SC Physics GA GJ675 UT WOS:A1991GJ67500037 ER PT J AU WHITE, AB FAIRALL, CW THOMSON, DW AF WHITE, AB FAIRALL, CW THOMSON, DW TI RADAR OBSERVATIONS OF HUMIDITY VARIABILITY IN AND ABOVE THE MARINE ATMOSPHERIC BOUNDARY-LAYER SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Humidity variability at the top of the marine atmospheric boundary layer and in the overlying free troposphere was examined using data collected during the marine stratocumulus phase of the First Regional Experiment (FIRE) of the International Satellite Cloud Climatology Program. A time series of the humidity structure-function parameter C(q)2 derived from Doppler wind profiler reflectivity data is compared to a concurrent time series of specific humidity q. Both q and its vertical gradient were calculated from rawinsonde data obtained from sondes launched within 500 m of the profiler. Time-height correlation analysis between log(C(q)2) and log(partial derivative q/partial derivative z)2 shows that the two time series are highly correlated at and just above the inversion base, with r approximately equal to 0.7. The correlation is slightly lower in the free troposphere where r is about 0.5 (a value of r greater than 0.2 is significant at the 95% confidence level). There is also correlation between log(C(q)2) and log(q), which is maximized at an offset in height between the two instruments. Closer analysis of a short-lived clearing event shows locally reduced values of C(q)2 in a region of enhanced partial derivative q/partial derivative z. This apparent paradox can be explained by noting the absence of enhanced entrainment associated with cloud-top radiative cooling. The combined wind profiler-rawinsonde datasets were also used to estimate the entrainment velocity w(e) for clear and cloudy conditions. An average value of w(e) equal to 0.38 cm s-1 was obtained for cloudy conditions; for the clear case a value of 0.13 cm s-1 was obtained. RP WHITE, AB (reprint author), NOAA,ENVIRONM RES LABS,MAIL CODE R-E-WP7,325 BROADWAY,BOULDER,CO 80303, USA. RI White, Allen/A-7946-2009 NR 0 TC 52 Z9 54 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 1991 VL 8 IS 5 BP 639 EP 658 DI 10.1175/1520-0426(1991)008<0639:ROOHVI>2.0.CO;2 PG 20 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA GJ501 UT WOS:A1991GJ50100003 ER PT J AU VENZ, S DICKENS, B AF VENZ, S DICKENS, B TI NIR-SPECTROSCOPIC INVESTIGATION OF WATER SORPTION CHARACTERISTICS OF DENTAL RESINS AND COMPOSITES SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article AB A near infrared (NIR) method using the 5200 cm-1 absorption of water has been employed to examine water absorbed in photopolymerized dental resins and composites in the form of 0.01-cm- to 0.15-cm-thick specimens. The concentration, c [mol L-1], of absorbed water in specimens of thickness t [cm] was calculated by means of Beer's law, A = epsilon-ct. A is the NIR absorbance and epsilon is the absorptivity of absorbed water. Epsilon-depends on the environment of the water molecule and it is necessary to estimate epsilon for water in each material. Water sorption was determined gravimetrically and correlated to the absorbance in the NIR spectrum. Once the relationship between-epsilon and water content was known for a material, water sorption was determined rapidly on very thin specimens for faster equilibration. Where dissolution of the specimen occurred, the solubility behavior of the specimen was evaluated from a comparison of NIR and gravimetric measurements. The NIR absorptivity, epsilon, of water absorbed in a polymeric medium was found to be inversely related to the degree of hydrophilicity and hydrogen bonding capability of the polymer. The presence of water clusters in a polyethylene oxide methacrylate polymer was inferred from convex-up curvature in the plot of epsilon vs. water content. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RP VENZ, S (reprint author), NATL INST STAND & TECHNOL,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899, USA. NR 21 TC 64 Z9 64 U1 0 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD OCT PY 1991 VL 25 IS 10 BP 1231 EP 1248 DI 10.1002/jbm.820251005 PG 18 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA GF652 UT WOS:A1991GF65200004 PM 1812117 ER PT J AU MEYER, CW MORRISON, G AF MEYER, CW MORRISON, G TI DIPOLE-MOMENTS OF 7 REFRIGERANTS SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB Dielectric constant measurements have been performed on seven refrigerants in the gaseous state over the range 305-415 K in order to determine their dipole moments. Four of the refrigerants have temperature-independent moments: R123 (1,1-dichloro-2,2,2-trifluoroethane), mu = 1.356 +/- 0.019 D; R141b (1,1-dichloro-1-fluoroethane), mu = 2.014 +/- 0.018 D; R22 (chlorodifluoromethane), mu = 1.458 +/- 0.003 D; and R32 (difluoromethane), mu = 1.978 +/- 0.007 D. Two refrigerants have conformer-dependent moments, making their time-averaged moments temperature dependent: R114 (1,2-dichloro-1,1,2,2-tetrafluoroethane), with a moment ranging from 0.668 +/- 0.001 D at 308 K to 0.699 +/- 0.001 D at 410 K; and E134 (bis(difluoromethyl) ether), where the moment ranges from 1.739 +/- 0.002 D at 309 K to 1.840 +/- 0.001 D at 410 K. One refrigerant, R123a (1,2-dichloro-1,1,2-trifluoroethane), has a moment that in principle could be temperature-dependent but in fact is temperature-independent; its value is mu = 1.302 +/- 0.007 D. Accurate determination of a molecule's temperature-dependent dipole moment requires an independent determination of its electronic polarizability; this determination has been made from index of refraction measurements. Where possible, the present results are compared with earlier determinations of dipole moments. RP MEYER, CW (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 21 TC 38 Z9 38 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD OCT PY 1991 VL 36 IS 4 BP 409 EP 413 DI 10.1021/je00004a019 PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA GK469 UT WOS:A1991GK46900019 ER PT J AU HO, J ERVIN, KM POLAK, ML GILLES, MK LINEBERGER, WC AF HO, J ERVIN, KM POLAK, ML GILLES, MK LINEBERGER, WC TI A STUDY OF THE ELECTRONIC-STRUCTURES OF PD2- AND PD2 BY PHOTOELECTRON-SPECTROSCOPY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID 2-PHOTON IONIZATION SPECTROSCOPY; METAL CLUSTER ANIONS; NEGATIVE-IONS; BINDING-ENERGIES; STATES; ABINITIO; SPECTROMETRY; NICKEL; PT2; ATOMS AB The ultraviolet negative ion photoelectron spectrum of Pd2- is presented for electron binding energies up to 3.35 eV. The anion is prepared by sputtering in a flowing afterglow ion source. Multiple low-lying electronic states of Pd2, all unidentified previously, are observed with resolved vibrational structure. The spectrum shows two strong electronic bands, each with similar vibrational progressions. Franck-Condon analyses are carried out on the two transitions and molecular constants are extracted for the anion and the two neutral electronic states. With the help of simple molecular orbital arguments and ab initio calculations, these two electronic bands are assigned as the triplet ground state (3-SIGMA-u+) and a singlet excited state (1-SIGMA-u+). The adiabatic electron affinity is E.A.(Pd2) = 1.685 +/- 0.008 eV and the singlet excitation energy T0(1-SIGMA-u+) is 0.497 +/- 0.008 eV (4008 +/- 65 cm-1). The bonding in the palladium dimers is discussed and we find that the anion bond strength is 1.123 +/- 0.013 eV stronger than that of the neutral. Related studies of Pd- yield an improved electron affinity of E.A.(Pd) = 0.562 +/- 0.005 eV. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP HO, J (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309, USA. NR 40 TC 60 Z9 61 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 OCT 1 PY 1991 VL 95 IS 7 BP 4845 EP 4853 DI 10.1063/1.461702 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH356 UT WOS:A1991GH35600014 ER PT J AU GOODWIN, ARH MOLDOVER, MR AF GOODWIN, ARH MOLDOVER, MR TI THERMOPHYSICAL PROPERTIES OF GASEOUS REFRIGERANTS FROM SPEED-OF-SOUND MEASUREMENTS .2. RESULTS FOR 1,1-DICHLORO-1-FLUOROETHANE (CCL2FCH3) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPHERICAL RESONATOR; TEMPERATURE AB The speed of sound in gaseous 1,1-dichloro-1-fluoroethane (CCl2FCH3, commonly known as R141b) has been measured between 260 and 315 K. Perfect-gas heat capacities and second acoustic virial coefficients have been calculated from the results. The second acoustic virial coefficients are used to estimate the density virial coefficients B(T) and an effective square-well potential. Our estimates of B(T) are consistent with B(T) deduced from high-quality p(V(m), T) results. We provided estimates of the vibrational relaxation time for R141b. RP GOODWIN, ARH (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 16 TC 25 Z9 26 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 1991 VL 95 IS 7 BP 5230 EP 5235 DI 10.1063/1.461694 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH356 UT WOS:A1991GH35600054 ER PT J AU GOODWIN, ARH MOLDOVER, MR AF GOODWIN, ARH MOLDOVER, MR TI THERMOPHYSICAL PROPERTIES OF GASEOUS REFRIGERANTS FROM SPEED-OF-SOUND MEASUREMENTS .3. RESULTS FOR 1,1-DICHLORO-2,2,I-TRIFLUOROETHANE (CHCL2-CF3) AND 1,2-DICHLORO-1,2,2-TRIFLUOROETHANE (CHCLF-CCLF2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMO-PHYSICAL PROPERTIES; SPHERICAL RESONATOR; 1,1-DICHLORO-2,2,2-TRIFLUOROETHANE; TEMPERATURE; DENSITIES; ALKANES; VAPOR AB The speed of sound in gaseous 1,1-dichloro-2,2,2-trifluoroethane (CHCl2CF3, commonly known as R123) has been measured at temperatures T between 260 and 335 K at pressures p from 1.6 to 77 kPa. Perfect-gas heat capacities and second and third acoustic virial coefficients have been calculated from the results. The second and third acoustic virial coefficients are used to estimate the density virial coefficients B(T) and C(T) and an effective square-well potential. The acoustic estimates of B(T) and C(T) are consistent with B(T) and C(T) deduced from high-quality (p,V(m),T) results. The combined values of B(T) and C(T) cover a reduced temperature range of 0.57 to 0.99. We have also measured the speed of sound in 1,2-dichloro-1,2,2-trifluoroethane (CHClF-CClF2, commonly known as R123a). This isomer of R123 is a significant impurity in R123 as manufactured and used. We provided estimates of the vibrational relaxation time for R123. RP GOODWIN, ARH (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 23 TC 44 Z9 44 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 OCT 1 PY 1991 VL 95 IS 7 BP 5236 EP 5242 DI 10.1063/1.461831 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH356 UT WOS:A1991GH35600055 ER PT J AU BECKERLE, JD CAVANAGH, RR CASASSA, MP HEILWEIL, EJ STEPHENSON, JC AF BECKERLE, JD CAVANAGH, RR CASASSA, MP HEILWEIL, EJ STEPHENSON, JC TI SUBPICOSECOND TRANSIENT INFRARED-SPECTROSCOPY OF ADSORBATES - VIBRATIONAL DYNAMICS OF CO/PT(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID REFLECTION-ABSORPTION-SPECTROSCOPY; ADSORPTION SYSTEM PT(111)-CO; CO(V=1) POPULATION LIFETIMES; ELECTRON-PHONON RELAXATION; CARBONYL CLUSTER COMPOUNDS; ASYMMETRIC LINE-SHAPES; 2-PHONON BOUND-STATES; DILUTE CHCL3 SOLUTION; HOLE PAIR MECHANISM; OH(V = 1) AB The vibrational dynamics of excited CO layers on Pt(111) were studied using infrared (IR) pump-probe methods. Resonant IR pulses of 0.7 ps duration strongly pumped the absorption line (nu almost-equal-to 2106 cm-1) of top-site CO. Weak probe pulses delayed a time t(D) after the pump were reflected from the CO-covered Pt(111) surface, and dispersed in a monochromator to determine the absorption spectrum of the vibrationally excited CO band, with time resolution < 1 ps and monochromator resolution < 1 cm-1. Transient spectra were obtained as a function of CO coverage, surface temperature, and laser fluence. Complex spectra for t(D) < 0 show features characteristic of a perturbed free induction decay, which are expected based on multiple-level density-matrix models. For t(D) greater-than-or-equal-to 0, the CO/Pt absorption exhibits a shift to lower frequency and an asymmetric broadening which are strongly dependent on fluence (1.3-15 mJ/cm2). Spectra return to equilibrium (unexcited) values within a few picoseconds. These transient spectral shifts and the time scale for relaxation do not depend (within experimental error) on coverage for 0.1 less-than-or-equal-to THETA-CO less-than-or-equal-to 0.5 ML or on temperature for 150 less-than-or-equal-to T(s) less-than-or-equal-to 300 K. A model for coupled anharmonic oscillators qualitatively explains the t(D) > 0 spectra in terms of a population-dependent decrease in frequency of the one-phonon band, as opposed to a transition involving a true CO(upsilon = 2) two-phonon bound state. The rapid relaxation time and its insensitivity to T(s) and THETA-CO are consistent with electron-hole pair generation as the dominant decay mechanism. C1 CLEMSON UNIV, DEPT CHEM, CLEMSON, SC 29634 USA. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 93 TC 119 Z9 119 U1 2 U2 18 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 1991 VL 95 IS 7 BP 5403 EP 5418 DI 10.1063/1.461657 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GH356 UT WOS:A1991GH35600078 ER PT J AU GAFFEN, DJ BARNETT, TP ELLIOTT, WP AF GAFFEN, DJ BARNETT, TP ELLIOTT, WP TI SPACE AND TIME SCALES OF GLOBAL TROPOSPHERIC MOISTURE SO JOURNAL OF CLIMATE LA English DT Article AB Radiosonde data from a global 118-station network are used to determine the spatial and temporal scales of variability of tropospheric water vapor. Various sources of possible error and bias in the data are analyzed. Changes in instrumentation at U.S. stations are shown to have a considerable influence on the record; information on comparable changes in other countries is not readily available. Mean monthly data are shown to be acceptable at tropical stations but not at high-latitude stations, where the nonlinear dependence of saturation vapor pressure on temperature, coupled with large temperature ranges, leads to biases of up to 10% in mean monthly specific humidity. A series of three empirical orthogonal function analyses (for the tropics, North America, and the globe) of specific humidity at the surface, 850-mb, 700-mb, and 500-mb levels is presented. All three show evidence of a shift in the specific humidity field in the winter of 1976/77, with generally lower values from the beginning of the record (January 1973) until the shift and higher values through the winter of 1985/86. This shift is shown to be consistent with other evidence for a change in "climate state" in about 1977. The influence of the El Nino-Southern Oscillation is evident in both the tropical and global analyses. RP GAFFEN, DJ (reprint author), NOAA,AIR RESOURCES LAB,SSNC2,ROOM 9358,1325 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 0 TC 89 Z9 90 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 OCT PY 1991 VL 4 IS 10 BP 989 EP 1008 DI 10.1175/1520-0442(1991)004<0989:SATSOG>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GU112 UT WOS:A1991GU11200002 ER PT J AU EPSTEIN, ES AF EPSTEIN, ES TI DETERMINING THE OPTIMUM NUMBER OF HARMONICS TO REPRESENT NORMALS BASED ON MULTIYEAR DATA SO JOURNAL OF CLIMATE LA English DT Article AB Appropriately defined goodness-of-fit statistics are shown to provide a reasonable and objective means to determine the optimum number of harmonics to represent an annual climatology. The method is described in terms of its application, with varying degrees of success, to 5-day temperature means, their standard deviations, and to 5-day means of daily maximum and minimum temperatures. RP EPSTEIN, ES (reprint author), NOAA,NWS,CTR CLIMATE ANAL,5200 AUTH RD,CAMP SPRINGS,MD 20233, USA. NR 0 TC 5 Z9 5 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 OCT PY 1991 VL 4 IS 10 BP 1047 EP 1051 DI 10.1175/1520-0442(1991)004<1047:DTONOH>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GU112 UT WOS:A1991GU11200006 ER PT J AU SHENTON, HW JONES, NP AF SHENTON, HW JONES, NP TI BASE EXCITATION OF RIGID BODIES .1. FORMULATION SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID ROCKING RESPONSE; BLOCKS AB This paper presents the general, two-dimensional formulation for the response of free-standing rigid bodies to base excitation. The formulation assumes rigid body, rigid foundation, and Coulomb friction. The behavior is described in terms of the five possible modes of response (rest, slide, rock, slide-rock, and free-flight) and impact between the body and foundation. The governing equations of motion are summarized for the modes: slide, rock, and slide-rock. Approximate equations are outlined for the rock and slide-rock modes that are valid for small angles of rotation. A model governing impact from a rock, slide-rock or free-flight mode is derived from first principles using classical impact theory. This model assumes a point-impact, nonzero coefficient of restitution and finite value of friction. The paper presents a complete and consistent formulation, which can be used in its entirety or in part, for investigation of the generalized response using suitable analytical or numerical techniques. C1 JOHNS HOPKINS UNIV,DEPT CIVIL ENGN,BALTIMORE,MD 21218. RP SHENTON, HW (reprint author), NBS,GAITHERSBURG,MD 20899, USA. RI Jones, Nicholas/A-2328-2010 NR 21 TC 78 Z9 78 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD OCT PY 1991 VL 117 IS 10 BP 2286 EP 2306 DI 10.1061/(ASCE)0733-9399(1991)117:10(2286) PG 21 WC Engineering, Mechanical SC Engineering GA GH419 UT WOS:A1991GH41900007 ER PT J AU SHENTON, HW JONES, NP AF SHENTON, HW JONES, NP TI BASE EXCITATION OF RIGID BODIES .2. PERIODIC SLIDE-ROCK RESPONSE SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID BLOCKS AB An approximate closed-form solution is developed for a single-mode, steady-state slide-rock response resulting from a harmonic ground acceleration. The approximate solution is developed using the method of slowly varying parameters and is valid for a rectangular block undergoing small angles of rotation at the frequency of base excitation. Impacts with the foundation are assumed to be perfectly plastic and frictional impulses are included. Periodic solutions are found to exist in general only for relatively high amplitudes of ground acceleration and friction less than the inverse aspect ratio of the block. The rock component of the response is sensitive to changes in aspect ratio and friction and insensitive to changes in ground acceleration. The slide component of response is approximately equal to the amplitude of ground displacement and is insensitive to changes in friction and aspect ratio. Results compare favorably to those obtained by numerical integration. The accuracy of the approximate solution is shown to depend heavily on the magnitude of impulse applied during impact. C1 JOHNS HOPKINS UNIV,DEPT CIVIL ENGN,BALTIMORE,MD 21218. RP SHENTON, HW (reprint author), NBS,GAITHERSBURG,MD 20899, USA. RI Jones, Nicholas/A-2328-2010 NR 11 TC 26 Z9 26 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD OCT PY 1991 VL 117 IS 10 BP 2307 EP 2328 DI 10.1061/(ASCE)0733-9399(1991)117:10(2307) PG 22 WC Engineering, Mechanical SC Engineering GA GH419 UT WOS:A1991GH41900008 ER PT J AU DOMENECH, JL JUNTTILA, ML PINE, AS AF DOMENECH, JL JUNTTILA, ML PINE, AS TI MOLECULAR-BEAM SPECTRUM OF THE 3.3-MU-M NU-12-BAND OF BENZENE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FUNDAMENTAL-BAND; LASER SPECTROSCOPY; COMPLEXES; C6H6 RP DOMENECH, JL (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Domenech, Jose/F-5561-2013 OI Domenech, Jose/0000-0001-8629-2566 NR 24 TC 15 Z9 15 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1991 VL 149 IS 2 BP 391 EP 398 DI 10.1016/0022-2852(91)90294-K PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GE833 UT WOS:A1991GE83300007 ER PT J AU DCUNHA, R DEO, MN WEBER, A OLSON, WB AF DCUNHA, R DEO, MN WEBER, A OLSON, WB TI ANALYSIS OF THE NU-8-BAND OF METHYLENE FLUORIDE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INFRARED-SPECTRUM; SUBMILLIMETER EMISSIONS; LASER LINES; DIFLUOROMETHANE; CH2F2 C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP DCUNHA, R (reprint author), BHABHA ATOM RES CTR,DIV SPECT,BOMBAY 400085,INDIA. NR 19 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1991 VL 149 IS 2 BP 412 EP 424 DI 10.1016/0022-2852(91)90296-M PG 13 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GE833 UT WOS:A1991GE83300009 ER PT J AU CHUANG, TJ LIU, WJ WIEDERHORN, SM AF CHUANG, TJ LIU, WJ WIEDERHORN, SM TI STEADY-STATE CREEP-BEHAVIOR OF SI-SIC C-RINGS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SILICONIZED SILICON-CARBIDE; DAMAGE-ENHANCED CREEP AB Because of the ease of experimental setup as well as economics in sample preparation, C-ring specimens are sometimes chosen for the evaluation of mechanical behavior. In this paper, the long-term creep of siliconized silicon carbide (Si-SiC) C-rings is investigated. Creep tests on a number of Si-SiC C-rings were carried out under constant compressive loads at 1300-degrees-C in air. Load-point displacements were continually monitored as a function of time, thereby establishing the steady-state regime as a function of load and ring geometry. Optical micrography on the postcrept specimens was performed to obtain damage zone sizes. A simple curved beam theory was employed to analyze the stress state developed throughout the body during steady-state creep. Load-point displacement rates were numerically calculated using both geometric and energy methods. Observed damage zone sizes and shapes within the specimen agreed with those predicted theoretically. Results obtained on the stress solutions are useful as local loading parameters in the study of high-temperature fracture behavior of a cracked C-ring. RP CHUANG, TJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 19 TC 4 Z9 6 U1 0 U2 5 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 OCT PY 1991 VL 74 IS 10 BP 2531 EP 2537 DI 10.1111/j.1151-2916.1991.tb06795.x PG 7 WC Materials Science, Ceramics SC Materials Science GA GM652 UT WOS:A1991GM65200029 ER PT J AU KRUEGER, S LONG, GG BLACK, DR MINOR, D JEMIAN, PR NIEMAN, GW PAGE, RA AF KRUEGER, S LONG, GG BLACK, DR MINOR, D JEMIAN, PR NIEMAN, GW PAGE, RA TI EVOLUTION OF THE PORE-SIZE DISTRIBUTION IN FINAL-STAGE SINTERING OF ALUMINA MEASURED BY SMALL-ANGLE X-RAY-SCATTERING SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ENTROPY AB Small-angle X-ray scattering was used to follow the evolution of the pore size distribution during final-stage sintering of alumina and of alumina doped with 0.25 wt% magnesia. The volume-weighted (Guinier) results indicate that the effective size of the largest pores increases as the body goes from 97% to more than 99% dense. The surface-area-weighted (Porod) results show that the median size of the smallest pores decreases slightly over the same density range. Taken together, these data indicate that the pore size distribution becomes broader as final-stage densification proceeds. This was confirmed by a maximum entropy analysis, which was used to derive pore size distributions directly from the data. Finally, the evolution of the pore size distributions in alumina, with and without sintering aid, were compared. C1 NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60208. SOUTHWEST RES INST,SAN ANTONIO,TX 78228. RP KRUEGER, S (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 15 TC 12 Z9 13 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1991 VL 74 IS 10 BP 2538 EP 2546 DI 10.1111/j.1151-2916.1991.tb06796.x PG 9 WC Materials Science, Ceramics SC Materials Science GA GM652 UT WOS:A1991GM65200030 ER PT J AU HENDON, HH LIEBMANN, B AF HENDON, HH LIEBMANN, B TI THE STRUCTURE AND ANNUAL VARIATION OF ANTISYMMETRIC FLUCTUATIONS OF TROPICAL CONVECTION AND THEIR ASSOCIATION WITH ROSSBY GRAVITY-WAVES SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DISTURBANCES AB The signature of 4-5-day period Rossby-gravity waves is searched for in the tropical convection field across the Indian-Pacific oceans. The convergence/divergence field of these waves in the lower troposphere is anticipated to produce an antisymmetric fluctuation in tropical convection. Antisymmetric fluctuations of tropical convection are shown to exhibit a pronounced spectral peak at a 4-5-day period only during boreal fall and only within about 30-degrees longitude of the date line. The peak amplitude occurs around 7.5-degrees latitude. These fluctuations propagate westward at 15-20 m s-1 with zonal wavelength of about 7000-9000 km. The fluctuations of convection are coherent and out of phase with the equatorial meridional wind, which also exhibits a pronounced spectral peak at a 4-5-day period in the lower troposphere near the date fine. The antisymmetric zonal wind also is strongly coherent with the antisymmetric convective fluctuations in this region. The horizontal distributions of the 4-5-day power and coherence of the winds and convection are consistent with that produced by a convectively coupled Rossby-gravity wave that is confined near the date line. The localization of the convectively coupled Rossby-gravity wave activity near the date line during boreal fall is postulated to be due to the unique meridional distribution of sea surface temperature at this location. The equatorial minimum flanked by maxima at about 5-degrees-10-degrees latitude is thought to encourage antisymmetric convection, which interacts efficiently with Rossby-gravity waves. The fall maximum in convectively coupled Rossby-gravity wave activity is consistent with these unique sea surface temperatures occurring only during fall. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP HENDON, HH (reprint author), UNIV COLORADO,CTR ATMOSPHER THEORY & ANAL,CAMPUS BOX 391,BOULDER,CO 80309, USA. NR 21 TC 66 Z9 66 U1 0 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 OCT 1 PY 1991 VL 48 IS 19 BP 2127 EP 2140 DI 10.1175/1520-0469(1991)048<2127:TSAAVO>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GQ811 UT WOS:A1991GQ81100002 ER PT J AU THURBER, WR LOWNEY, JR LARRABEE, RD EHRSTEIN, JR AF THURBER, WR LOWNEY, JR LARRABEE, RD EHRSTEIN, JR TI AC IMPEDANCE METHOD FOR HIGH-RESISTIVITY MEASUREMENTS OF SILICON SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB An ac impedance method for measuring the average bulk resistivity of ingots and slices of high-resistivity silicon is presented. Easily removable contacts, such as silver paint, are applied to the end faces of the sample, and the complex impedance of the resulting capacitive sandwich is measured as a function of frequency. The resistivity can be calculated from the frequency of the negative peak in the imaginary part of the impedance and from the absolute values of the real and imaginary parts at that frequency. The spectroscopic nature of the method gives an inherent separation of contact, surface region, and bulk effects as the respective responses usually occur at widely different frequencies. In addition to its intended application for measuring bulk resistivity, the method is useful for determining the quality of applied contacts and the effect of surface treatments which result in a significant depletion layer. Plots and the required data can be obtained very quickly with an appropriate microprocessor-based impedance analyzer. Extensive measurements of high-resistivity silicon were done to compare the method with the dc resistance, van der Pauw, and four-probe techniques. The agreement was within 5% for slices and ingot sections greater than 0.1 cm in length and resistivity above 5 k-OMEGA . cm. RP THURBER, WR (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 12 TC 2 Z9 2 U1 2 U2 6 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD OCT PY 1991 VL 138 IS 10 BP 3081 EP 3085 DI 10.1149/1.2085372 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA GJ144 UT WOS:A1991GJ14400050 ER PT J AU SUGAR, J KAUFMAN, V ROWAN, WL AF SUGAR, J KAUFMAN, V ROWAN, WL TI RESONANCE LINES 4P6-4P54D OF THE KR-I ISOELECTRONIC SEQUENCE SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID EXPERIMENTAL LEVEL VALUES; SPECTRA AB Lines of the 4s24p6 1S0-4s24p54d 1P1 and 3D1 transitions in Kr-like ions were observed in the plasma of the TEXT tokamak doped with elements Pd to Sb and I, Xe, Cs, and Nd. An electron temperature of 1.3 keV was achieved by operating the tokamak with He. Spectra in the range of 50-400 angstrom were observed photographically with a 2.2-m grazing-incidence spectrograph. The lines were identified by comparison with calculated transition energies along the isoelectronic sequence. C1 UNIV TEXAS,FUS RES CTR,AUSTIN,TX 78712. RP SUGAR, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 7 TC 9 Z9 9 U1 1 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD OCT PY 1991 VL 8 IS 10 BP 2026 EP 2027 DI 10.1364/JOSAB.8.002026 PG 2 WC Optics SC Optics GA GJ655 UT WOS:A1991GJ65500004 ER PT J AU WANG, FX LACEY, P GATES, RS HSU, SM AF WANG, FX LACEY, P GATES, RS HSU, SM TI A STUDY OF THE RELATIVE SURFACE CONFORMITY BETWEEN 2 SURFACES IN SLIDING CONTACT SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID WEAR AB The surface roughnesses of two surfaces in a wear contact can change throughout the course of the wear process. This may or may not change the lubrication mechanism of the system depending on the real area of contact as influenced by the changes in the surface roughness. The present work examines the changes in surface roughness within the contact area, as well as the relative mating of the two surfaces. To quantify the similarity between the two wear surfaces, a new concept, the relative surface conformity, has been defined and developed. To effectively measure this parameter, a computer program was written to input the wear scar profilometry traces and to calculate the relative surface conformity of the two. Finally, the relative surface conformity was shown to rise with increasing test duration, during running in. C1 NBS,DIV CERAM,GAITHERSBURG,MD 20899. RP WANG, FX (reprint author), TSING HUA UNIV,BEIJING,PEOPLES R CHINA. NR 17 TC 33 Z9 33 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD OCT PY 1991 VL 113 IS 4 BP 755 EP 761 DI 10.1115/1.2920689 PG 7 WC Engineering, Mechanical SC Engineering GA GM025 UT WOS:A1991GM02500014 ER PT J AU HANNINGTON, M HERZIG, P SCOTT, S THOMPSON, G RONA, P AF HANNINGTON, M HERZIG, P SCOTT, S THOMPSON, G RONA, P TI COMPARATIVE MINERALOGY AND GEOCHEMISTRY OF GOLD-BEARING SULFIDE DEPOSITS ON THE MIDOCEAN RIDGES SO MARINE GEOLOGY LA English DT Review ID EAST PACIFIC RISE; DE-FUCA RIDGE; BACK-ARC BASIN; HYDROTHERMAL SOLUTIONS; ATLANTIC RIDGE; GALAPAGOS RIFT; CHEMICAL-COMPOSITION; CHLORIDE COMPLEXES; MASSIVE SULFIDES; NEW-ZEALAND AB A comparative study of the mineralogy and geochemistry of sulfide deposits on mid-ocean ridges in the Northeast Pacific and the Mid-Atlantic reveals common characteristics associated with primary gold enrichment. Average gold contents of 0.8 to 5 ppm Au occur in sulfides from Southern Explorer Ridge and Axial Seamount (Northeast Pacific) and from the TAG hydrothermal field and Snakepit vent field (Mid-Atlantic Ridge). The enrichment of gold in these deposits is consistently related to a phase of late-stage, low-temperature (< 300-degrees-C) venting. Concentrations > 1 ppm Au occur exclusively in pyritic assemblages and commonly with abundant Fe-poor sphalerite and a suite of complex Pb-Sb-As sulfosalts. Amorphous silica and, locally, barite or carbonate are important constituents of the gold-rich precipitates but do not contain gold themselves. High-temperature (350-degrees-C) black smoker assemblages, consisting dominantly of pyrite, chalcopyrite, pyrrhotite, isocubanite and abundant anhydrite are uniformly gold-poor (less-than-or-equal-to 0.2 ppm Au). To the extent that individual sulfides can be mechanically separated, chemical analyses by neutron activation indicate that gold is most abundant in sphalerite (up to 5.7 ppm Au) but also occurs in pyrite and marcasite. Samples of sphalerite with abundant inclusions of fine-grained sulfosalts locally contain up to 18 ppm Au, suggesting that sulfosalts may be repositories for gold. No free gold has been observed at 4000 x magnification of polished specimens, indicating that the gold is present only as submicroscopic inclusions or as a chemical constituent within the sulfides. Samples from gold-rich deposits in the Northeast Pacific and Mid-Atlantic are compared with similar but relatively gold-poor sulfides from the Galapagos Rift and 13-degrees-N on the East Pacific Rise (EPR), and with barren sulfides from 11-degrees-N EPR, 21-degrees-N EPR, the Endeavour Ridge, and the Southern Juan de Fuca Ridge. Trace element analyses of more than 170 samples show that gold enrichment in almost all of the deposits is associated with high concentrations of Ag, As, Sb, Pb and Zn, and locally with high Cd, Hg, Tl, and Ga. In contrast, gold is typically depleted in samples with high Co, Se, and Mo. The close association of Au with Ag, As, Sb, and Pb may reflect the common behavior of these metals as aqueous sulfur complexes (e.g., [Au(HS)2-]) at low temperatures. Similar mineralogical and geochemical associations are observed in sulfide deposits from modern back-arc settings and in the ancient geologic record. C1 RHEIN WESTFAL TH AACHEN,INST MINERAL & ECON GEOL,AACHEN,GERMANY. UNIV TORONTO,CTR EARTH SCI,DEPT GEOL,TORONTO M5S 3B1,ONTARIO,CANADA. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. NOAA,MIAMI,FL 33149. RP HANNINGTON, M (reprint author), GEOL SURVEY CANADA,OTTAWA K1A 0E8,ONTARIO,CANADA. NR 117 TC 76 Z9 85 U1 0 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD OCT-NOV PY 1991 VL 101 IS 1-4 BP 217 EP 248 DI 10.1016/0025-3227(91)90073-D PG 32 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA GQ083 UT WOS:A1991GQ08300016 ER PT J AU DELONG, RL STEWART, BS AF DELONG, RL STEWART, BS TI DIVING PATTERNS OF NORTHERN ELEPHANT SEAL BULLS SO MARINE MAMMAL SCIENCE LA English DT Article DE PINNIPEDIA; NORTHERN ELEPHANT SEAL; MIROUNGA-ANGUSTIROSTRIS; TIME-DEPTH RECORDER; DIVING PATTERNS; FORAGING ECOLOGY ID MIROUNGA-ANGUSTIROSTRIS; FEEDING-HABITS; WEDDELL SEALS; BEHAVIOR AB We used small microprocessor-based, time-depth recorders to document the diving patterns of six adult male northern elephant seals (Mirounga angustirostris) from San Miguel Island, California. The recorders stored measurements of hydrostatic pressure every 30 or 60 sec while the seals were at sea for 107 to 145 d in spring and early summer; collectively, over 36,000 dives were recorded. Seals dove continually while at sea, most often to depths of 350-450 m although two seals had secondary modes at about 700-800 m; maximum depths for two seals of 1,333 m and 1,529 m are the deepest yet measured for air-breathing vertebrates. Seals were submerged about 86% of the time they were at sea, rarely spending more than 5 min at the surface between dives; 99% of all post-dive surface intervals were shorter than 10 min. Dives averaged 21-24 min; the longest was 77 min. The uninterrupted patterns of long dives punctuated by brief surface periods suggest that most if not all dives were well within these seals' aerobic limits. Dives of bulls were, on average, about 18% longer than those published earlier for cows, evidently because of the substantially greater body mass of bulls and allometric scaling of dive endurance. Dive depths and dive durations varied seasonally; depths were greatest in spring, durations greatest in early summer. During each season dives were deepest during the day and shallowest at night except for the sixth seal whose consistently shallow dives (50-150 m) in spring were independent of time of day. Prey remains recovered by lavage from seals' stomachs were primarily of vertically migrating, epi- and meso-pelagic squid. The diel patterns in dive depths suggest that five seals dove to and foraged in the offshore mesopelagic zone, pursuing those vertically migrating prey. The sixth seal behaved similarly in early spring and early summer but may have foraged in nearshore epibenthic habitats in spring. C1 HUBBS SEA WORLD RES INST,1700 S SHORES RD,SAN DIEGO,CA 92109. NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. NR 33 TC 64 Z9 64 U1 0 U2 8 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 OCT PY 1991 VL 7 IS 4 BP 369 EP 384 DI 10.1111/j.1748-7692.1991.tb00112.x PG 16 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA GN344 UT WOS:A1991GN34400002 ER PT J AU COLMAN, BR AF COLMAN, BR TI THUNDERSTORMS ABOVE FRONTAL SURFACES IN ENVIRONMENTS WITHOUT POSITIVE CAPE .1. A CLIMATOLOGY - REPLY SO MONTHLY WEATHER REVIEW LA English DT Note ID INSTABILITY RP COLMAN, BR (reprint author), NOAA,NATL WEATHER SERV,SEATTLE FORECAST OFF,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 8 TC 4 Z9 4 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1991 VL 119 IS 10 BP 2514 EP 2515 DI 10.1175/1520-0493(1991)119<2514:R>2.0.CO;2 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL879 UT WOS:A1991GL87900013 ER PT J AU AKMAN, SA FORREST, GP DOROSHOW, JH DIZDAROGLU, M AF AKMAN, SA FORREST, GP DOROSHOW, JH DIZDAROGLU, M TI MUTATION OF POTASSIUM PERMANGANATE-TREATED AND HYDROGEN PEROXIDE-TREATED PLASMID PZ189 REPLICATING IN CV-1 MONKEY KIDNEY-CELLS SO MUTATION RESEARCH LA English DT Article DE POTASSIUM PERMANGANATE; HYDROGEN PEROXIDE; HYDROXYL RADICAL; FORMAMIDOPYRIMIDINE; THYMINE GLYCOL ID THYMINE GLYCOL LESIONS; ACTIVATED POLYMORPHONUCLEAR LEUKOCYTES; CHROMATOGRAPHY MASS-SPECTROMETRY; SHUTTLE VECTOR PLASMID; DNA-POLYMERASE-I; MAMMALIAN-CELLS; IONIZING-RADIATION; OXIDATIVE DAMAGE; TUMOR PROMOTER; GLYCOSYLASE ACTIVITY AB We examined the effect of the oxidation of plasmid pZl89 by KMnO4, which does not produce free radicals, and H2O2/Fe2+-diethylenetriaminepentaacetic acid (DTPA), which does, on the mutation frequency of pZ189 transfected into monkey kidney CV-1 cells. Treatment with 1.5 mM KMnO4 increased the content of certain modified bases, principally Thy and Cyt modified at C-5 and C-6, by up to 300-fold, as measured by GC/MS; however, the mutation frequency increased only 5-fold above background. 1.0 mM H2O2/0-1 mM Fe2+-DTPA treatment, which increased the mutation frequency 10-fold above background, increased the content of certain modified bases by up to 4-fold. Sequence analysis revealed both deletions and point mutations, with a predominance of C-G substitutions, among H2O2/Fe2+-DTPA-associated mutations. These data suggest that KMnO4-modified DNA is only weakly mutagenic in DNA replicating in mammalian nuclei, despite substantial production of Thy glycol and other base modifications, whereas H2O2/Fe2+-DTPA-modified DNA is more mutagenic. H2O2/Fe2+-DTPA generated mutations occur predominantly at C-G base pairs. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. CITY HOPE NATL MED CTR,BECKMAN RES INT,DIV BIOL,DUARTE,CA 91010. RP AKMAN, SA (reprint author), CITY HOPE NATL MED CTR,DEPT MED ONCOL & THERAPEUT RES,DUARTE,CA 91010, USA. FU NCI NIH HHS [CA31788, CA33572] NR 47 TC 36 Z9 36 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD OCT PY 1991 VL 261 IS 2 BP 123 EP 130 DI 10.1016/0165-1218(91)90058-T PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GK665 UT WOS:A1991GK66500005 PM 1922155 ER PT J AU CHOW, LC AF CHOW, LC TI DEVELOPMENT OF SELF-SETTING CALCIUM-PHOSPHATE CEMENTS SO NIPPON SERAMIKKUSU KYOKAI GAKUJUTSU RONBUNSHI-JOURNAL OF THE CERAMIC SOCIETY OF JAPAN LA English DT Article DE CALCIUM PHOSPHATE CEMENT; DICALCIUM PHOSPHATE; HYDROXYAPATITE; TETRACALCIUM PHOSPHATE; BONE IMPLANT MATERIAL; SELF-SETTING CEMENT AB This paper reviews recent studies on self-setting calcium phosphate cements (CPC). Discussions are focused on the cement setting reactions, the products formed, the effects of the products on properties of the cement, and in vivo characteristics of CPC. Although cementation can occur in systems based on several different mixtures, data in the literature at present indicate that mixtures of tetracalcium phosphate and dicalcium phosphate (or dicalcium phosphate dihydrate) may be most desirable because they produce cements that have greater strengths and contain nearly pure hydroxyapatite. The strengths of CPC are considerably lower than ceramic calcium phosphate biomaterial and are also lower than some of the dental cements. On the other hand, the combination of self-setting capability and high biocompatibility makes CPC a unique biomaterial. Near perfect adaptation of the cement to the tissue surfaces in a defect, and an optimum resorption rate followed by new bone formation are some of the distinctive advantages of CPC. In its present state CPC appears to be suitable for a number of applications. Much remains to be done to further improve its properties to meet the requirements for different applications. RP CHOW, LC (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 0 TC 138 Z9 139 U1 2 U2 20 PU CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI PI TOKYO PA 22-17 HYAKUNIN-CHO SHINJUKU-KU, TOKYO 169, JAPAN SN 0914-5400 J9 NIPPON SERAM KYO GAK PD OCT PY 1991 VL 99 IS 10 BP 954 EP 964 PG 11 WC Materials Science, Ceramics SC Materials Science GA GK934 UT WOS:A1991GK93400013 ER PT J AU COPLEY, JRD AF COPLEY, JRD TI SCATTERING EFFECTS WITHIN AN ABSORBING SPHERE IMMERSED IN A FIELD OF NEUTRONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID MONTE-CARLO CALCULATION; MULTIPLE-SCATTERING AB We study the flux distribution within an isolated sphere in a field of neutrons, in the one-speed approximation. The sphere is characterized by its radius R and its macroscopic scattering and absorption cross sections, SIGMA-S and SIGMA-A respectively. The ratio of the average flux within the sphere to the unperturbed flux (into which the sphere was placed) is designated f. We show that f is independent of the directional nature of the external neutron field; for example it is the same for a neutron beam as for an isotropic field. For a purely absorbing sphere f is well known and easily derived. For a purely scattering sphere it is unity. For a sphere which both scatters and absorbs neutrons f is calculated using the neutron transport equation. For a given size of sphere we find that f decreases (slightly) as SIGMA-S is increased at constant SIGMA-A. An implication of these results, in the context of prompt-gamma neutron activation analysis experiments with neutron beams, is that the use of spherical samples should be encouraged when working with strong scatterers such as hydrogenous material since the uncertainty in the correction for scattering effects is relatively small for this shape of sample. RP COPLEY, JRD (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 15 TC 19 Z9 20 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 1 PY 1991 VL 307 IS 2-3 BP 389 EP 397 DI 10.1016/0168-9002(91)90209-9 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA GJ748 UT WOS:A1991GJ74800034 ER PT J AU BENNISON, SJ PADTURE, NP RUNYAN, JL LAWN, BR AF BENNISON, SJ PADTURE, NP RUNYAN, JL LAWN, BR TI FLAW-INSENSITIVE CERAMICS SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID SCANNING ELECTRON-MICROSCOPE; BRIDGED CRACK INTERFACES; AL2O3 BEND SPECIMENS; FRACTURE ORIGINS; STRENGTH PROPERTIES; INSITU MEASUREMENTS; RESISTANCE; ALUMINA; STABILITY; TOUGHNESS AB Ceramics are notorious for their 'brittleness', i.e. the sensitivity of mechanical strength to flaws on the microstructural scale. The associated notion of the 'critical flaw' has dominated design considerations concerning structural reliability and materials processing of ceramic components. This accounts for the trend over the last decade towards a processing strategy of elimination strength-degrading flaws at source. Here we propose a fundamentally different approach, that of processing ceramics with crack-impeding elements integrated into the indigenous microstructures, such that any pre-existing or service-induced flaws are effectively stabilized. Strength data on a tailored alumina/aluminium-titanate material demonstrate the capacity of our approach to produce simple ceramics with unique flaw insensitivity. RP BENNISON, SJ (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. RI Padture, Nitin/A-9746-2009 OI Padture, Nitin/0000-0001-6622-8559 NR 24 TC 29 Z9 29 U1 1 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD OCT PY 1991 VL 64 IS 4 BP 191 EP 195 DI 10.1080/09500839108214542 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA GJ658 UT WOS:A1991GJ65800003 ER PT J AU ROWE, JM PRASK, HJ AF ROWE, JM PRASK, HJ TI STATUS OF RESEARCH REACTOR INSTRUMENTATION IN THE USA SO PHYSICA B LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON NEUTRON SCATTERING CY JAN 21-25, 1991 CL BOMBAY, INDIA SP US, DEPT ATOM ENERGY AB Significant upgrades are planned or are occurring in most of the existing major beam-research reactors in the United States. These range from the installation of new instruments to major additions such as cold neutron guide halls. In this paper the current status and planned upgrades are reviewed for four of the major US reactor facilities: the NBSR and Cold Neutron Research Facility at NIST, the HFIR at Oak Ridge, the HFBR at Brookhaven, and the MURR at the University of Missouri. RP ROWE, JM (reprint author), NATL INST STANDARDS & TECHNOL,DIV REACTOR RADIAT,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Rowe, J Michael Rowe/D-2943-2013 NR 5 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD OCT PY 1991 VL 174 IS 1-4 BP 421 EP 429 DI 10.1016/0921-4526(91)90640-Z PG 9 WC Physics, Condensed Matter SC Physics GA GJ931 UT WOS:A1991GJ93100078 ER PT J AU LOUGHRAN, RJ GOLDFARB, RB AF LOUGHRAN, RJ GOLDFARB, RB TI ANISOTROPIC WEAK-LINK PROPERTIES AND INTERGRANULAR LOWER CRITICAL-FIELD OF GRAIN-ALIGNED YBA2CU3OX SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; TRANSPORT CRITICAL CURRENT; HIGH-TC SUPERCONDUCTORS; MAGNETIZATION; Y1BA2CU3O7-DELTA; ALIGNMENT AB We studied the weak-link nature of sintered, grain-aligned YBa2Cu3Ox using DC magnetization and AC susceptibility. The sample was highly anisotropic for fields applied perpendicular and parallel to the grains' a, b planes. For fields applied perpendicular to the a, b planes, the magnetization curves show small integranular coupling losses and the susceptibility curves show sharp coupling transitions. For parallel fields there are large coupling losses and broad transitions. From AC susceptibility measurements in parallel fields, the intergranular lower critical fields are no higher than 0.15 kA/m (1.9 Oe) at 76 K and 0.5 kA/m (6.3 Oe) at 4 K. In perpendicular applied fields, the fields were 0.3 kA/m (3.8 Oe) at 76 K and 1.3 kA/m (16.3 Oe) at 4 K. RP LOUGHRAN, RJ (reprint author), NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 24 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD OCT 1 PY 1991 VL 181 IS 1-3 BP 138 EP 142 DI 10.1016/0921-4534(91)90346-Z PG 5 WC Physics, Applied SC Physics GA GL392 UT WOS:A1991GL39200020 ER PT J AU DZUBA, VA FLAMBAUM, VV SUSHKOV, OP AF DZUBA, VA FLAMBAUM, VV SUSHKOV, OP TI RESONANCE ENHANCEMENT OF RELATIVISTIC EFFECTS FOR THE SCATTERING OF VERY SLOW-ELECTRONS BY HEAVY-ATOMS SO PHYSICAL REVIEW A LA English DT Article ID ENERGY-LEVELS; CESIUM AB Polarization of scattered electrons is enhanced up to 1 near p- and d-wave resonances or weakly bound negative-ion energy levels (\E\ less-than-or-similar-to 0.1 eV, upsilon-2/c2 less-than-or-similar-to 10(-6)). We consider as example Ra and Ba. We also note that the cross section for Ra is very large (> 10(11) b at electron energy approximately 10(-2) eV). C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP DZUBA, VA (reprint author), NOVOSIBIRSK NUCL PHYS INST,NOVOSIBIRSK 630090,USSR. NR 16 TC 16 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT 1 PY 1991 VL 44 IS 7 BP 4224 EP 4227 DI 10.1103/PhysRevA.44.4224 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GK884 UT WOS:A1991GK88400023 ER PT J AU GALLAGHER, A AF GALLAGHER, A TI ASSOCIATIVE IONIZATION IN COLLISIONS OF SLOWED AND TRAPPED SODIUM SO PHYSICAL REVIEW A LA English DT Article ID ATOMS; LOSSES; COLD AB Collisions of trapped atoms occur over time intervals that are often longer than radiative lifetimes. This leads to radiative interruption of excited-state collision dynamics and constrains collisional interactions to atom pairs that are in close proximity at the time of excitation. Using classical dynamics I show that this causes Na associative ionization to be dominated by a four-step process in which the longer-range Na*-Na interaction initiates inward motion that is completed as Na* + Na* --> Na2 dagger + e. Thus low-temperature associative ionization does not result from Na* + Na* collisions. I predict strong single- and two-wavelength dependences, which have a molecular character due to the close proximity at the time of photoabsorption. These are amenable to experimental observation. I also calculate saturation that results from the depletion of interacting pairs. This produces very-low-power saturation and explains the associative ionization measurements of Gould et al. [Phys. Rev. Lett. 60, 788 (1988)]. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. NR 15 TC 29 Z9 29 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT 1 PY 1991 VL 44 IS 7 BP 4249 EP 4259 DI 10.1103/PhysRevA.44.4249 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GK884 UT WOS:A1991GK88400026 ER PT J AU JULIENNE, PS VIGUE, J AF JULIENNE, PS VIGUE, J TI COLD COLLISIONS OF GROUND-STATE AND EXCITED-STATE ALKALI-METAL ATOMS SO PHYSICAL REVIEW A LA English DT Article ID POTENTIAL-ENERGY CURVES; TRAPPED NEUTRAL ATOMS; SODIUM ATOMS; OPTICAL MOLASSES; ELECTRONIC-STRUCTURE; PHOTO-DISSOCIATION; MULTILEVEL ATOMS; RESONANCE LINES; CROSS-SECTIONS; DOPPLER LIMIT AB This paper examines two collisional mechanisms by which cold alkali-metal atoms can escape from a neutral-atom trap, due to collison of excited- and ground-state atoms. One is fine-structure-changing collisions, by which the atoms are heated by the amount of the fine-structure splitting. The other produces hot ground-state atoms following emission of a red-shifted photon during the course of a collision. A rate expression is obtained that applies to both normal and ultracold temperatures (< 1 mK). This expression assumes a canonical distribution of initial states, low-intensity excitation, and a semiclassical treatment of the survival probability relative to excited-state decay during the long time of the ultracold collision, and uses fine-structure-changing probabilities found by quantum scattering calculations. The known properties of the attractive molecular states of the alkaline-metal dimers are used to identify and calculate the probabilities for the specific mechanisms. We conclude that the earlier semiclassical analysis by Dashevskaya [Opt. Spectrosk. 46, 423 (1979)] of the fine-structure-changing mechanisms for the various alkali-metal species is qualitatively correct. We present quantum-mechanical calculations of the rate coefficient for fine-structure-changing collisions between ground- and excited-state Cs atoms from 1000 K to 100-mu-K. Collision-rate coefficients for the trap-loss processes are calculated for pairs of Li, Na, K, Rb, and Cs atoms at low temperature. There is a wide variation of predicted loss rate among alkali-metal species from the fastest for K and the slowest for Li. Retardation corrections to molecular lifetimes must be taken into account to predict the correct rate coefficients for Na, K, and Rb. Good agreement is obtained with the observed trap loss rate in a Cs trap. C1 ECOLE NORM SUPER,SPECT HERTZIENNE LAB,F-75231 PARIS,FRANCE. RP JULIENNE, PS (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 111 TC 165 Z9 168 U1 2 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT 1 PY 1991 VL 44 IS 7 BP 4464 EP 4485 DI 10.1103/PhysRevA.44.4464 PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GK884 UT WOS:A1991GK88400050 ER PT J AU MOHR, PJ AF MOHR, PJ TI LAMB SHIFT IN THE N=4 STATE OF HE+ SO PHYSICAL REVIEW A LA English DT Note AB An estimate for the higher-order binding correction to the Lamb shift in the n = 4 state in He+ is given, based on a new calculation. The result is in agreement with a recent measurement by Majumder and Pipkin [Phys. Rev. Lett. 63, 372 (1989)]. RP MOHR, PJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT 1 PY 1991 VL 44 IS 7 BP R4089 EP R4090 PG 2 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GK884 UT WOS:A1991GK88400001 ER PT J AU CRAWFORD, MK HARLOW, RL MCCARRON, EM FARNETH, WE AXE, JD CHOU, H HUANG, Q AF CRAWFORD, MK HARLOW, RL MCCARRON, EM FARNETH, WE AXE, JD CHOU, H HUANG, Q TI LATTICE INSTABILITIES AND THE EFFECT OF COPPER-OXYGEN-SHEET DISTORTIONS ON SUPERCONDUCTIVITY IN DOPED LA2CUO4 SO PHYSICAL REVIEW B LA English DT Note ID STRUCTURAL PHASE-TRANSITIONS; LA2-XBAXCUO4; TEMPERATURE; TRANSPORT; MECHANISM; LA2NIO4; OXIDE AB Synchroton x-ray and neutron-diffraction measurements demonstrate that Nd3+ substitution at the La3+ site in both metallic and insulating La2-xSrxCuO4 induces low-temperature structural instabilities which reorient the tilting of the copper-oxygen octahedra. These structural transformations strongly affect superconductivity. In addition, there is a bicritical point involving phases of Bmab, Pccn, and P4(2)/ncm space-group symmetries in the structural phase diagram of La1.6-xNd0.4SrxCuO4 at x approximately 0.15. There are also anomalies in the structural transformation temperatures and the superconducting transition temperatures when x approximately 1/8, providing evidence for an electronic instability at this doping level. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NATL INST STAND & TECHNOL,REACTOR E151,GAITHERSBURG,MD 20899. RP CRAWFORD, MK (reprint author), DUPONT CO,EXPTL STN,CENT RES & DEV,POB 80356,WILMINGTON,DE 19880, USA. NR 35 TC 249 Z9 250 U1 3 U2 15 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 OCT 1 PY 1991 VL 44 IS 14 BP 7749 EP 7752 DI 10.1103/PhysRevB.44.7749 PG 4 WC Physics, Condensed Matter SC Physics GA GH808 UT WOS:A1991GH80800075 ER PT J AU BUR, AJ GALLANT, FM AF BUR, AJ GALLANT, FM TI FLUORESCENCE MONITORING OF TWIN SCREW EXTRUSION SO POLYMER ENGINEERING AND SCIENCE LA English DT Article AB An optical fiber probe has been constructed in order to obtain real-time measurements of fluorescence radiation during twin screw mixing and extrusion of plasticized polybutadiene and calcium carbonate particulate. The probe consists of an optical fiber bundle which was inserted along the axis of a half-inch sensor bolt, and it was used to transmit optical excitation energy to the processed material and to detect the subsequent fluorescence. The source of fluorescence radiation was a fluorescent dye which was doped into the processed ingredients at very low concentrations. Although most of our measurements were taken with the probe positioned close to the exit die, the sensor bolt can be placed in any instrumentation port along the extruder line. Experiments were carried out to measure residence time distribution, quality-of-mix, and mix concentrations as a function of processing conditions. Product mix changes in response to variations in material feed rates and screw RPM were also observed. Values of residence time were obtained by measuring the transit times for the dye to travel from an upstream injection port to the measurement probe, a distance of 63 cm. Flow instabilities, such as mat formation of the solids, were observed by noting the abrupt changes and discontinuities in the fluorescence signal. C1 USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903. RP BUR, AJ (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 9 TC 19 Z9 21 U1 1 U2 4 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD OCT PY 1991 VL 31 IS 19 BP 1365 EP 1371 DI 10.1002/pen.760311902 PG 7 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA GL525 UT WOS:A1991GL52500001 ER PT J AU GARSTANG, RH AF GARSTANG, RH TI DUST AND LIGHT POLLUTION SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article DE OBSERVATORY SITES; LIGHT POLLUTION ID CHICHON ERUPTION CLOUD; EL-CHICHON; OCTOBER 1982; ABSORPTION; RADIATION; SITES AB We have refined our model for the prediction of the brightness of the night sky due to man-made light pollution by the addition of an ozone layer, by the use of a more accurate representation of the atmospheric molecular density variation as a function of height, and by using a better mathematical representation of the scattering angular function of aerosols. Each of these modifications leads to a small reduction in the predicted brightness of the night sky. We have also added to our model a thin layer of dust of arbitrary optical thickness and height above sea level. We have studied dust clouds at various heights and of various optical thicknesses. Most of our calculations have been performed for Kitt Peak National Observatory. Most calculations have used scattering and absorption coefficients appropriate for volcanic clouds; a few calculations refer to desert dust. Light pollution is reduced by a dust cloud of moderate density whose altitude is below about 10 km (for the V band) and increased for dust clouds at greater altitudes. Observations from good sites are not likely to be greatly affected by the increases in light pollution caused by volcanic clouds at altitudes of order 20 km. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. RP GARSTANG, RH (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 27 TC 33 Z9 33 U1 1 U2 8 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD OCT PY 1991 VL 103 IS 668 BP 1109 EP 1116 DI 10.1086/132933 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GN363 UT WOS:A1991GN36300009 ER PT J AU DOMALSKI, ES CHURNEY, KL LEDFORD, AE COLBERT, JC BRUCE, SS BUCKLEY, TJ PAULE, RC REILLY, ML AF DOMALSKI, ES CHURNEY, KL LEDFORD, AE COLBERT, JC BRUCE, SS BUCKLEY, TJ PAULE, RC REILLY, ML TI ASSESSING THE CREDIBILITY OF THE CALORIFIC CONTENT OF MUNICIPAL SOLID-WASTE SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 11TH CONF ON CHEMICAL THERMODYNAMICS CY AUG 26-31, 1990 CL COMO, ITALY SP INT UNION PURE & APPL CHEM ID OXYGEN FLOW CALORIMETER; KILOGRAM-SIZE SAMPLES AB A study has been carried out to establish the limits of reliability of the calorific content of municipal solid waste (MSW) by the bomb calorimetric procedure currently used in commercial test laboratories. This procedure involves using gram-size samples derived from MSW that have been processed down to a particle size of 2 mm or less. Critics argue that one cannot sample a multi-ton quantity of MSW and extract gram-size samples which are representative of the entire gross sample. They argue further that processing down to 2 mm or less significantly alters the composition of the sample. In order to test the bomb calorimetric procedure, a 2.5 kg capacity combustion flow calorimeter was designed and constructed for the determination of the enthalpies of combustion of kilogram-size samples of MSW in flowing oxygen near atmospheric pressure. Calorimetric data on processed MSW were obtained using both the kilogram-size flow and gram-size bomb calorimeters. The effects of processing on sample composition were determined by intercomparison of flow calorimetric results on kilogram-size samples of unprocessed and processed MSW that are nominally identical. We conclude that if proper care is taken in sampling large quantities of MSW and similar care is paid toward sample size reduction and subdivision, meaningful values can be obtained for the calorific content of MSW using the conventional bomb calorimetric procedure at the +/- 1% level. Differences in values for processed and unprocessed samples can be as much as +/- 3%, and are related to experimental difficulties in preparing "exactly identical" kg samples of MSW. RP DOMALSKI, ES (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD OCT PY 1991 VL 63 IS 10 BP 1415 EP 1418 DI 10.1351/pac199163101415 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA GN099 UT WOS:A1991GN09900013 ER PT J AU ABRAMOWITZ, S CHASE, MW AF ABRAMOWITZ, S CHASE, MW TI THERMODYNAMIC PROPERTIES OF GAS-PHASE SPECIES OF IMPORTANCE TO OZONE DEPLETION SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 11TH CONF ON CHEMICAL THERMODYNAMICS CY AUG 26-31, 1990 CL COMO, ITALY SP INT UNION PURE & APPL CHEM ID ENTHALPIES AB Thermodynamic and spectroscopic data have been evaluated for several chlorine-oxygen gas phase species of interest in the study of ozone depletion models. The evaluated data have been used to compute JANAF Thermochemical Tables for these species. The data will be discussed and applied to several proposed models for ozone depletion. The recent catalytic cycle involving ozone loss by ClO and Cl2O2 in the Antarctic stratosphere is discussed. C1 NATL INST STAND & TECHNOL,STAND REFERENCE DATA PROGRAM,GAITHERSBURG,MD 20899. RP ABRAMOWITZ, S (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 9 TC 52 Z9 52 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD OCT PY 1991 VL 63 IS 10 BP 1449 EP 1454 DI 10.1351/pac199163101449 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA GN099 UT WOS:A1991GN09900018 ER PT J AU MORRISON, G AF MORRISON, G TI ALTERNATIVE REFRIGERANT PROPERTIES MEASUREMENT AND CORRELATION PROGRAM AT NIST (NATIONAL-INSTITUTE-OF-STANDARDS-AND-TECHNOLOGY) SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 11TH CONF ON CHEMICAL THERMODYNAMICS CY AUG 26-31, 1990 CL COMO, ITALY SP INT UNION PURE & APPL CHEM AB The activities in the Thermophysics Division at NIST to produce both property measurements and correlations are discussed. These activities are directed toward providing information about materials that will be alternatives to the fully halogenated compounds presently used as working fluids. Seven property measurement apparatuses and three property correlation projects are described. RP MORRISON, G (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 29 TC 1 Z9 1 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD OCT PY 1991 VL 63 IS 10 BP 1465 EP 1472 DI 10.1351/pac199163101465 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA GN099 UT WOS:A1991GN09900020 ER PT J AU ROGERS, RR ZAWADZKI, II GOSSARD, EE AF ROGERS, RR ZAWADZKI, II GOSSARD, EE TI VARIATION WITH ALTITUDE OF THE DROP-SIZE DISTRIBUTION IN STEADY LIGHT RAIN SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article ID PRECIPITATION; CLOUD AB By application of the stochastic coalescence equation to evolving populations of cloud droplets and raindrops, we show that in light rain there is a range of drop sizes for which, to a good approximation, raindrops grow only by cloud accretion and are neither created by autoconversion nor destroyed by breakup. In these conditions, the differential equation that describes the one-dimensional steady-state form of the drop-size distribution may be solved analytically, using plausible assumptions about the cloud water content and the raindrop collection efficiency. The solution gives the drop-size distribution as a function of distance below a reference level, from which we can calculate radar-measurable quantities such as the reflectivity factor and the Doppler spectrum. Recent radar data from the Hawaiian Rainband Project provide the opportunity for a close comparison of the steady-state accretion theory with observations. An example is presented of a steady situation in which, over a limited range of altitude, the observed vertical profiles of reflectivity and Doppler velocity do agree reasonably well with the theory. Other observations in equally steady-appearing conditions, however, are not in accord with the theoretical predictions. If the parameters of the model are chosen to fit the velocity profile, the theory then tends to predict reflectivity gradients stronger than those actually observed. Similarly, if the parameters are chosen to fit the reflectivity profile, the predicted increase of Doppler velocity with distance fallen is less than what is observed. Effects of evaporation can be included in the steady-state model, and are shown to explain the sense of the discrepancy but not its magnitude. The conclusion is that the one-dimensional model, possibly because of its inability to account for horizontal advection, is usually inadequate to explain the observations. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV QUEBEC,DEPT PHYS,MONTREAL H3C 3P8,QUEBEC,CANADA. RP ROGERS, RR (reprint author), MCGILL UNIV,DEPT METEOROL,MONTREAL H3A 2T5,QUEBEC,CANADA. NR 13 TC 17 Z9 18 U1 3 U2 3 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 OCT PY 1991 VL 117 IS 502 BP 1341 EP 1369 DI 10.1002/qj.49711750211 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HH403 UT WOS:A1991HH40300010 ER PT J AU ELMQUIST, RE DZIUBA, RF AF ELMQUIST, RE DZIUBA, RF TI ISOLATED RAMPING CURRENT SOURCES FOR A CRYOGENIC CURRENT COMPARATOR BRIDGE SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID QUANTIZED-HALL-RESISTANCE AB The design and performance of a pair of highly isolated ramping and reversing direct-current sources for use with a cryogenic current comparator resistance bridge and dc superconducting quantum interference device (SQUID) detector are described. The current sources are floating and isolated from one another, and are internally programmed to reverse the output current while maintaining the SQUID feedback control system in lock. The sources are designed to have low zero offset in order to limit the change of the current ratio in the reversal sequence. Sources have been constructed with full-scale current ranges from 0.65 to 100 mA and have been used in the comparisons of precision standard resistors at the 0.01 ppm level. RP ELMQUIST, RE (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 1991 VL 62 IS 10 BP 2457 EP 2460 DI 10.1063/1.1142263 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GH598 UT WOS:A1991GH59800029 ER PT J AU ROBERTSON, DS AF ROBERTSON, DS TI GEOPHYSICAL APPLICATIONS OF VERY-LONG-BASE-LINE INTERFEROMETRY SO REVIEWS OF MODERN PHYSICS LA English DT Review ID ATMOSPHERIC ANGULAR-MOMENTUM; RADIO INTERFEROMETRY; POLAR MOTION; LINE INTERFEROMETRY; FORCED NUTATIONS; EARTHS ROTATION; CHANDLER-WOBBLE; PLATE MOTION; MARK-III; GRAVITATIONAL-FIELD AB Very-long-baseline interferometry (VLBI) is a novel observing technique for measuring the relative positons of widely separated points on the surface of the Earth with centimeter-level accuracy. Such accuracy is two or three orders of magnitude better than was available with classical techniques only a few decades ago. This enormous improvement in accuracy has opened up for study a broad new spectrum of geophysical phenomena. The new measurements allow direct observation of the tectonic motions and deformations of the Earth's crustal plates, observations of unprecedented detail of the variations in the rotation of the Earth, and direct measurement of the elastic deformations of the Earth in response to tidal forces. These new measurements have placed significant constraints on models of the interior structure of the Earth; for example, measurements of the variations in the Earth's nutation have been shown to be particulary sensitive to the shape of the core-mantle boundary. The VLBI measurements, coupled with other space-based geodetic observing techniques such as the Global Positioning System, allow construction of a global reference frame accurate at the centimeter level. Such a frame will be essential to studying long-term global changes, especially those changes related to sea-level variations as recorded by tide gauge measurements. RP ROBERTSON, DS (reprint author), NOAA,OFF OCEAN & EARTH SCI,GEOSCI LAB,ROCKVILLE,MD 20852, USA. NR 127 TC 22 Z9 24 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD OCT PY 1991 VL 63 IS 4 BP 899 EP 918 DI 10.1103/RevModPhys.63.899 PG 20 WC Physics, Multidisciplinary SC Physics GA GL695 UT WOS:A1991GL69500003 ER PT J AU CARASSO, AS KATO, T AF CARASSO, AS KATO, T TI ON SUBORDINATED HOLOMORPHIC SEMIGROUPS SO TRANSACTIONS OF THE AMERICAN MATHEMATICAL SOCIETY LA English DT Article DE SUBORDINATED SEMIGROUPS; HOLOMORPHIC EXTENSIONS AB If [e-tA] is a uniformly bounded C0 semigroup on a complex Banach space X , then -A-alpha, 0 < alpha < 1 generates a holomorphic semigroup on X, and [e-tA-alpha] is subordinated to [e-tA] through the Levy stable density function. This was proved by Yosida in 1960, by suitably deforming the contour in an inverse Laplace transform representation. Using other methods, we exhibit a large class of probability measures such that the subordinated semigroups are always holomorphic, and obtain a necessary condition on the measure's Laplace transform for that to be the case. We then construct probability measures that do not have this property. C1 UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720. RP CARASSO, AS (reprint author), NATL INST STAND & TECHNOL,CTR COMP & APPL MATH,GAITHERSBURG,MD 20899, USA. NR 15 TC 23 Z9 24 U1 0 U2 0 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 SN 0002-9947 J9 T AM MATH SOC JI Trans. Am. Math. Soc. PD OCT PY 1991 VL 327 IS 2 BP 867 EP 878 DI 10.2307/2001827 PG 12 WC Mathematics SC Mathematics GA GM712 UT WOS:A1991GM71200016 ER PT J AU RUSSELL, TP MENELLE, A HAMILTON, WA SMITH, GS SATIJA, SK MAJKRZAK, CF AF RUSSELL, TP MENELLE, A HAMILTON, WA SMITH, GS SATIJA, SK MAJKRZAK, CF TI WIDTH OF HOMOPOLYMER INTERFACES IN THE PRESENCE OF SYMMETRICAL DIBLOCK COPOLYMERS SO MACROMOLECULES LA English DT Article ID BLOCK COPOLYMERS; NEUTRON REFLECTIVITY; BLENDS; MIXTURES; TENSION; SYSTEMS; FILMS AB The interface between polystyrene and poly(methyl methacrylate) homopolymers was investigated as a function of the concentration of added symmetric diblock copolymer of PS and PMMA, denoted P(S-b-MMA), using neutron reflectivity. It was found that as the number of P(S-b-MMA) chains added to the interface between PS and PMMA was increased, the width of the gradient between the PS and PMMA segments broadened. In particular, the width of the interface between PS and PMMA homopolymers is 50 angstrom and, with the addition of P(S-b-MMA), increases to approximately 85 angstrom. At an amount corresponding to approximately half the thickness of the lamellar microdomain periodicity in the bulk, the interface becomes saturated with the copolymer. Further addition of copolymer chains to the interface results in a marked increase in the off-specular scattering, which is associated with either an ordering of the copolymer chains at the interface or an increase in the curvature of the interface. Studies were also performed on mixtures of homopolymers and copolymers. Here, the interface between the lamellar microdomains of the P(S-b-MMA) is found to increase from 50 angstrom for the pure copolymer to 75 angstrom as PS and PMMA homopolymer is added to the copolymer. The broadening of the interface seen in both sets of experiments is due to a significant penetration of the homopolymer into the interfacial region. These results are consistent with the reduction in the interfacial tension between the homopolymers with the addition of the diblock copolymer. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP RUSSELL, TP (reprint author), IBM CORP,DIV RES,ALMADEN RES CTR,650 HARRY RD,SAN JOSE,CA 95120, USA. NR 35 TC 77 Z9 77 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 30 PY 1991 VL 24 IS 20 BP 5721 EP 5726 DI 10.1021/ma00020a036 PG 6 WC Polymer Science SC Polymer Science GA GH467 UT WOS:A1991GH46700036 ER PT J AU SZYMONSKI, M KOLODZIEJ, J CZUBA, P PIATKOWSKI, P PORADZISZ, A TOLK, NH FINE, J AF SZYMONSKI, M KOLODZIEJ, J CZUBA, P PIATKOWSKI, P PORADZISZ, A TOLK, NH FINE, J TI NEW MECHANISM FOR ELECTRON-STIMULATED DESORPTION OF NONTHERMAL HALOGEN ATOMS FROM ALKALI-HALIDE SURFACES SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIRECTIONAL EMISSION; ENERGY AB Fully angular-resolved kinetic-energy distributions of alkali and halogen atoms emitted due to electron-stimulated desorption have been measured for (100) and (110) alkali-halide surfaces. An unexpected strong directional emission of nonthermal halogen atoms along the <100> axis of the investigated crystals has been found which is in contradiction to the predictions of the previously proposed "Pooley model." We propose a new model involving diffusion of hot holes to the surface, and sudden localization of the excited hole at the surface of the crystal. C1 VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899. RP SZYMONSKI, M (reprint author), JAGIELLONIAN UNIV,INST PHYS,UL REYMONTA 4,PL-30059 KRAKOW,POLAND. NR 23 TC 73 Z9 73 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 SEP 30 PY 1991 VL 67 IS 14 BP 1906 EP 1909 DI 10.1103/PhysRevLett.67.1906 PG 4 WC Physics, Multidisciplinary SC Physics GA GH407 UT WOS:A1991GH40700025 ER PT J AU KEIMER, B BIRGENEAU, RJ CASSANHO, A ENDOH, Y ERWIN, RW KASTNER, MA SHIRANE, G AF KEIMER, B BIRGENEAU, RJ CASSANHO, A ENDOH, Y ERWIN, RW KASTNER, MA SHIRANE, G TI SCALING BEHAVIOR OF THE GENERALIZED SUSCEPTIBILITY IN LA2-XSRXCUO4+Y SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERCONDUCTIVITY; OXIDES AB We have measured the static and dynamic spin fluctuations in a crystal of La2-xSrxCuO4+y in the spin-glass doping regime. The static spin correlations are well described by a simple model in which the inverse correlation length kappa(x, T) = kappa(x, 0) + kappa(0, T). The dynamic spin fluctuations exhibit a simple scaling behavior in omega/T for temperatures 10 K less-than-or-equal-to T less-than-or-equal-to 500 K for the measured energies 4.5 less-than-or-equal-to omega less-than-or-equal-to 12 meV. C1 TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 980,JAPAN. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP KEIMER, B (reprint author), MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. NR 19 TC 136 Z9 137 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 30 PY 1991 VL 67 IS 14 BP 1930 EP 1933 DI 10.1103/PhysRevLett.67.1930 PG 4 WC Physics, Multidisciplinary SC Physics GA GH407 UT WOS:A1991GH40700031 ER PT J AU GIBBLE, KE COOPER, J AF GIBBLE, KE COOPER, J TI SCATTERING ANGLE RESOLUTION IN MEASUREMENTS OF VELOCITY-CHANGING COLLISION KERNELS SO PHYSICAL REVIEW LETTERS LA English DT Letter C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NR 3 TC 7 Z9 7 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 30 PY 1991 VL 67 IS 14 BP 1936 EP 1936 DI 10.1103/PhysRevLett.67.1936 PG 1 WC Physics, Multidisciplinary SC Physics GA GH407 UT WOS:A1991GH40700034 ER PT J AU DOMEN, SR KRAUSS, A ROOS, M AF DOMEN, SR KRAUSS, A ROOS, M TI THE PROBLEM OF CONVECTION IN THE WATER ABSORBED DOSE CALORIMETER SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 9TH ULM CALORIMETRY CONF CY MAR 18-19, 1991 CL ULM UNIV, ULM, GERMANY SP ULM UNIV, SEKT KALORIMETRY HO ULM UNIV AB The water absorbed dose calorimeter allows the water absorbed dose, the measurand in radiotherapy, to be measured in accordance with its definition. Its application, however, requires the suppression of convection. In the present paper we investigate how far the convection problem may be solved by mechanical means, for the case of Co-60-gamma-radiation. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP DOMEN, SR (reprint author), PHYS TECH BUNDESANSTALT,W-3300 BRAUNSCHWEIG,GERMANY. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD SEP 30 PY 1991 VL 187 BP 225 EP 233 DI 10.1016/0040-6031(91)87197-5 PG 9 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA GH892 UT WOS:A1991GH89200024 ER PT J AU DECKMAN, DE JAHANMIR, S HSU, SM AF DECKMAN, DE JAHANMIR, S HSU, SM TI WEAR MECHANISMS OF ALPHA-ALUMINA LUBRICATED WITH A PARAFFIN OIL SO WEAR LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 07-11, 1991 CL ORLANDO, FL ID BOUNDARY LUBRICATION; CERAMICS; FRICTION AB The effect of load, sliding speed and lubricant temperature on the tribological performance of polycrystalline alpha-alumina was investigated. A four-ball test geometry was used with a purified paraffin oil lubricant. The test results showed that the wear behavior of this material was strongly dependent on the contact load. Mild to severe wear transitions occurred at particular loads, depending on lubricant temperature and sliding speed. The transition load was found to decrease as either the lubricant temperature or the sliding speed was increased. The onset of transition is explained by the failure of the lubricating film due to an increase in flash temperature. Examination of the worn surfaces by scanning electron microscopy revealed that intergranular fracture was the primary mechanism for severe wear. RP DECKMAN, DE (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 15 TC 15 Z9 17 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD SEP 30 PY 1991 VL 149 IS 1-2 BP 155 EP 168 DI 10.1016/0043-1648(91)90370-A PG 14 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GL443 UT WOS:A1991GL44300011 ER PT J AU HEWITT, RP DEMER, DA AF HEWITT, RP DEMER, DA TI KRILL ABUNDANCE SO NATURE LA English DT Letter ID ANTARCTIC KRILL; SOUND C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92038. RP HEWITT, RP (reprint author), SW FISHERIES SCI CTR,LA JOLLA,CA 92038, USA. NR 6 TC 47 Z9 47 U1 1 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD SEP 26 PY 1991 VL 353 IS 6342 BP 310 EP 310 DI 10.1038/353310b0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GG654 UT WOS:A1991GG65400042 ER PT J AU MUNROE, TA NIZINSKI, MS MAHADEVA, MN AF MUNROE, TA NIZINSKI, MS MAHADEVA, MN TI SYMPHURUS-PROLATINARIS, A NEW SPECIES OF SHALLOW-WATER TONGUEFISH (PLEURONECTIFORMES, CYNOGLOSSIDAE) FROM THE EASTERN PACIFIC SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Symphurus prolatinaris is described from 201 specimens collected in shallow waters on the continental shelf (9-162 m, 96% taken between 13 and 42 m) from northern Mexico to central Peru. A medium-sized tonguefish, S. prolatinaris attains maximum lengths of 161 mm SL, with females maturing at ca. 98 mm SL. The new species is characterized by a predominant 1-5-3-2-2 pattern of interdigitation of dorsal pterygiophores and neural spines; 12 caudal-fin rays; 102-112 dorsal-fin rays; 85-93 anal-fin rays; 54-58 total vertebrae; four hypurals; a lightly-pigmented, triangular, veil-like pupillary operculum; 3-8 small, ctenoid scales on the blind sides of dorsal- and anal-fin rays; a pronounced, tubular, anterior nostril on the blind side; the first dorsal-fin ray located anterior to a vertical through the front margin of the upper eye; and the ocular-side lower jaw without a pronounced fleshy ridge on its posterior extent. Symphurus prolatinaris is most similar to S. chabanaudi Mahadeva & Munroe, but differs notably from that species in possessing a pupillary operculum, in pigmentation, and in its more anteriorly placed dorsal fin. RP MUNROE, TA (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD SEP 25 PY 1991 VL 104 IS 3 BP 448 EP 458 PG 11 WC Biology SC Life Sciences & Biomedicine - Other Topics GA HD777 UT WOS:A1991HD77700003 ER PT J AU WILLIAMS, AB MOFFITT, RB AF WILLIAMS, AB MOFFITT, RB TI CRABS FROM THE MARIANA ARCHIPELAGO - BOTHROMAIA-GRIFFINI NEW GENUS AND SPECIES (BRACHYURA, MAJIDAE), AND REMARKS ON POUPINIA-HIRSUTA GUINOT (HOMOLOIDEA, POUPINIIDAE) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Deepwater trapping in the Mariana Archipelago, western North Pacific Ocean, included incidental catches of a spider crab and a homoloid crab with novel characteristics. Bothromaia griffini, new genus and species, family Majidae, subfamily Inachinae, represented by a male and female, seems most closely related to the genus Pleistacantha Miers, containing several species distributed in Indo-Pacific waters. The new species resembles members of this genus with respect to presence of pseudorostral horns, and shape of eyestalks, basal antennal article, epistome, third maxilliped, male sternites and pleopod 1, but differs from them in shape of pseudorostral horns, carapace, male pleopod, and in proportions of the ambulatory legs. Descriptions, illustrations, and comparative discussion are presented. Notes on the homoloid crab, Poupinia hirsuta Guinot, include locality data, measurements, remarks on distribution, and discussion of features distinguishing the families of Homoloidea, including a key for their identification. RP WILLIAMS, AB (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 0 TC 4 Z9 4 U1 2 U2 2 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD SEP 25 PY 1991 VL 104 IS 3 BP 569 EP 582 PG 14 WC Biology SC Life Sciences & Biomedicine - Other Topics GA HD777 UT WOS:A1991HD77700012 ER PT J AU WINELAND, DJ BOLLINGER, JJ HEINZEN, DJ ITANO, WM RAIZEN, MG AF WINELAND, DJ BOLLINGER, JJ HEINZEN, DJ ITANO, WM RAIZEN, MG TI SEARCH FOR ANOMALOUS SPIN-DEPENDENT FORCES USING STORED-ION SPECTROSCOPY SO PHYSICAL REVIEW LETTERS LA English DT Article ID EQUIVALENCE PRINCIPLE EXPERIMENT; REVERSIBLE PHOTON OSCILLATIONS; CONSTANT MAGNETIC-FIELD; LONG-RANGE; GOLDSTONE BOSONS; CP CONSERVATION; NULL RESULT; INVARIANCE; PARTICLES; GYROSCOPE AB Resonances in atomic ions can be used to search for new, weak, spin-dependent interactions. Upper limits on anomalous dipole-monopole and dipole-dipole couplings for the neutron and electron are determined by examining hyperfine resonances in stored Be-9(+) ions. These experiments also place strict limits on anomalous weights of spinning gyroscopes. C1 UNIV TEXAS, DEPT PHYS, AUSTIN, TX 78712 USA. RP NATL INST STAND & TECHNOL, DIV TIME & FREQUENCY, BOULDER, CO 80303 USA. NR 50 TC 62 Z9 62 U1 1 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 23 PY 1991 VL 67 IS 13 BP 1735 EP 1738 DI 10.1103/PhysRevLett.67.1735 PG 4 WC Physics, Multidisciplinary SC Physics GA GG106 UT WOS:A1991GG10600017 ER PT J AU DANIELSON, BL AF DANIELSON, BL TI PRECISE LENGTH MEASUREMENTS IN MULTIMODE OPTICAL FIBERS SO APPLIED OPTICS LA English DT Article DE LENGTH MEASUREMENTS; MULTIMODE FIBER LENGTH; OPTICAL-FIBER GROUP INDEX; OPTICAL-FIBER GROUP DELAY; OPTICAL-FIBER LENGTH; OPTICAL-TIME-DOMAIN REFLECTOMETER CALIBRATION AB Selective optical excitation permits both the group index and the group delay of on-axis modes of multimode fibers to be determined with high precision. The group index of several types of fiber was measured at 1310 nm in a fiber Michelson interferometer, and the values were tabulated. Group delays were obtained from the transit time of short-duration optical pulses. From these data the length of reference fibers approximately 2 km long was calculated. Length-measurement accuracy was limited by group-index uncertainties to approximately 0.04%. Also, a technique that uses these reference fibers to minimize uncertainties in distance measurements made with multimode optical-time-domain reflectometers is described. RP DANIELSON, BL (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 1991 VL 30 IS 27 BP 3867 EP 3872 PG 6 WC Optics SC Optics GA GJ124 UT WOS:A1991GJ12400018 PM 20706475 ER PT J AU WANG, QD HELFAND, DJ AF WANG, QD HELFAND, DJ TI LMC-2 AS THE BLOWOUT OF A HOT SUPERBUBBLE SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES - MAGELLANIC CLOUDS; STARS - CIRCUMSTELLAR SHELLS; STARS - SUPERGIANTS; X-RAYS - SOURCES ID LARGE MAGELLANIC CLOUD; PROPAGATING STAR FORMATION; H-I SHELLS; INTERSTELLAR-MEDIUM; SUPERNOVA-REMNANTS; SUPERSHELLS; GALAXIES; EVOLUTION; DYNAMICS; CYGNUS AB Based on the data collected with the imaging proportional counter (IPC) aboard the Einstein Observatory, we have discovered a bright extended X-ray emission region which is enclosed by the supershell LMC-2 identified from optical and radio observations. The diffuse X-rays appear to come from hot gas in a corresponding superbubble. The X-ray count rate of the superbubble is approximately 1.4 counts s-1 in the IPC broad band (0.16-3.5 keV), corresponding to a luminosity of approximately 2 x 10(37) ergs s-1 with a gas temperature approximately 5 x 10(6) K. The bright X-ray emission region appears as a ring with a radius of approximately 15' and correlates well with a cold ISM cavity seen in both the H I and IRAS maps, but is much smaller than the region bounded by the optical filaments. We suggest that LMC-2 has been created by the breakout of the superbubble from the dense galactic plane of the Large Cloud. The bright X-ray emission arises near the plane, where the superbubble is energized by stellar winds and supernova explosions. The blown-out superbubble expands rapidly in the low-density region away from the plane on the far side of the galaxy; its boundary is marked by absorption of soft X-rays in the dense H I shell it creates, and rim-brightened optical filaments at the interface between the hot interior and the cold swept-up medium. This observation represents the first clear evidence of such a hot superbubble in an external galaxy. We go on to speculate that the massive ridge of gas at the eastern edge of the LMC in which the bubble has arisen was formed as a result of the interaction of the LMC disk with the gaseous halo of the Milky Way. The high pressure and density characteristic of this interaction region has triggered the massive star formation which is responsible for creating the superbubble LMC-2. C1 NBS,WASHINGTON,DC 20234. COLUMBIA UNIV,COLUMBIA ASTROPHYS LAB,538 W 120TH ST,NEW YORK,NY 10027. RP WANG, QD (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,CAMPUS BOX 440,BOULDER,CO 80309, USA. NR 50 TC 44 Z9 44 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 SEP 20 PY 1991 VL 379 IS 1 BP 327 EP 337 DI 10.1086/170507 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GF749 UT WOS:A1991GF74900029 ER PT J AU TSUDA, T VANZANDT, TE MIZUMOTO, M KATO, S FUKAO, S AF TSUDA, T VANZANDT, TE MIZUMOTO, M KATO, S FUKAO, S TI SPECTRAL-ANALYSIS OF TEMPERATURE AND BRUNT-VAISALA FREQUENCY FLUCTUATIONS OBSERVED BY RADIOSONDES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GRAVITY-WAVE SPECTRUM; UNIVERSAL SPECTRUM; LOWER STRATOSPHERE; ATMOSPHERE; RADAR; MODEL AB We observed profiles of the temperature, T, and Brunt-Vaisala frequency squared, N2, from 0 to 30 km in altitude using radiosondes with 150 m height resolution launched from the MU observatory, Japan (34-degrees-51'N, 136-degrees-06'E), from September 27, 1986, to February 24, 1989. We analyzed vertical wavenumber spectra of the normalized temperature T'/T and N2 fluctuations in the 2.0-8.5 km (troposphere) and 18.5-25.0 km (lower stratosphere) altitude ranges and compared them with model spectra based on saturated gravity wave theory. In the winter stratosphere the slope of the mean T'/T spectra in the wavenumber range from 7.0 x 10(-4) to 2.0 x 10(-3) (cycles per meter) was very close to the -3 predicted by the model, and the spectral amplitudes were 1.3-1.9 times larger than the predicted values, which is within the possible range of variability of the model. On the other hand, in the summer stratosphere the spectral slope ranged from -2.2 to -2.4, which is more gradual than the model, and the spectral amplitudes were only 0.4 to 0.5 of the predictions. The spectral shape in the troposphere did not show a significant difference between summer and winter. The spectral amplitudes, however, exceeded the model values by factors of about 3.2 and 1.9 in winter and summer, respectively. The overall shape of the T'2BAR profile for fluctuations with vertical scales from 150 to 900 m was generally similar to the shape of the background value of N4, consistent with the saturated gravity wave model, but the details of the altitude variations were rather complicated. That is, T'2/N4BAR just below the tropopause usually exceeded the model by a factor of 2 to 4, and it became significantly smaller than the model in the summer stratosphere and in a region above 25 km in winter. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. RP KYOTO UNIV, CTR RADIO ATMOSPHER SCI, UJI, KYOTO 611, JAPAN. RI tsuda, toshitaka/A-3035-2015 NR 13 TC 92 Z9 96 U1 1 U2 9 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 SEP 20 PY 1991 VL 96 IS D9 BP 17265 EP 17278 DI 10.1029/91JD01944 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH375 UT WOS:A1991GH37500011 ER PT J AU HANSON, DR RAVISHANKARA, AR AF HANSON, DR RAVISHANKARA, AR TI THE REACTION PROBABILITIES OF CLONO2 AND N2O5 ON 40-PERCENT TO 75-PERCENT SULFURIC-ACID-SOLUTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HETEROGENEOUS CHEMISTRY; WATER DROPLETS; TEMPERATURE; KINETICS; AEROSOLS; HNO3; HCL AB A wetted-wall flow tube was used to measure the reaction probabilities, gamma, of ClONO2 and N2O5 on sulfuric acid surfaces. The reaction probabilities were determined from first-order wall loss rate coefficients measured over sulfuric acid slowly flowing down the inside wall of the flow tube. Sulfuric acid content was varied from 40 to 75% by weight, and measurements were conducted at temperatures characteristic of the stratosphere. We determined the reaction probabilities of N2O5 to be 0.12 +/- 0.03 over 40% acid at 215 K, 0.14 +/- 0.03 over 60% acid at 215 K and 0.10 +/- 0.02 over 70 and 75% acid at 220 and 230 K, respectively. The gamma for ClONO2 increased from 2 x 10(-4) over 75% acid at 230 K to 6.4 x 10(-2) over 40% acid at 215 K; these are a factor of 2 lower than a previous determination performed under the same conditions. When we introduced HCl into the flow tube, we detected negligible uptake over the 65 and 70% acid solutions, gamma < 3 x 10(-5), and a small uptake, gamma = 4 x 10(-4), for HCl onto 60% acid at 215 K. We did not detect a significant enhancement in the first-order loss rate coefficients for ClONO2 over these solutions in the presence of HCl. Thus the reaction ClONO2 + HCl occurring on 40-75 wt. % sulfuric acid solutions will not be a significant source of activated chlorine in the stratosphere; however, loss of N2O5 and ClONO2 could affect the NO(x) and ClO(x) concentrations. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP HANSON, DR (reprint author), NOAA, AERON LAB, RE AL2, 325 S BROADWAY, BOULDER, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 20 TC 193 Z9 194 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 SEP 20 PY 1991 VL 96 IS D9 BP 17307 EP 17314 DI 10.1029/91JD01750 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH375 UT WOS:A1991GH37500015 ER PT J AU DANIELSEN, EF HIPSKIND, RS STARR, WL VEDDER, JF GAINES, SE KLEY, D KELLY, KK AF DANIELSEN, EF HIPSKIND, RS STARR, WL VEDDER, JF GAINES, SE KLEY, D KELLY, KK TI IRREVERSIBLE TRANSPORT IN THE STRATOSPHERE BY INTERNAL WAVES OF SHORT VERTICAL WAVELENGTH SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB The U-2 aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. STERLING SOFTWARE, PALO ALTO, CA 94043 USA. FORSCHUNGSZENTRUM JULICH, W-5170 JULICH 1, GERMANY. NOAA, AERON LAB, ENVIRONM RES LABS, BOULDER, CO 80303 USA. NR 28 TC 59 Z9 59 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 SEP 20 PY 1991 VL 96 IS D9 BP 17433 EP 17452 DI 10.1029/91JD01362 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GH375 UT WOS:A1991GH37500035 ER PT J AU KELLY, KK TUCK, AF DAVIES, T AF KELLY, KK TUCK, AF DAVIES, T TI WINTERTIME ASYMMETRY OF UPPER TROPOSPHERIC WATER BETWEEN THE NORTHERN AND SOUTHERN HEMISPHERES SO NATURE LA English DT Article ID EVOLUTION; CLIMATE; VAPOR; OZONE; CO2 AB WATER vapour is an important greenhouse gas 1-3 and yet its abundance in the upper troposphere is poorly known. Upper-tropospheric water vapour is particularly important despite its low mixing ratios, because it has large effects on the flux of infrared radiation near the tropopause 2. In addition, the distribution and supply of water vapour are central to cloud formation; the effects of cloud on the Earth's radiation budget are in turn central to understanding the climate response to increasing atmospheric concentrations of greenhouse gases. From airborne measurements of total water (vapour plus ice crystal) 4 during the winters of 1987 in the Southern Hemisphere and of 1988-89 in the Northern Hemisphere, we find that the upper troposphere in middle, subpolar and high latitudes is a factor of 2-4 drier during austral winter than during boreal winter. As the lower-latitude air moves towards the pole in austral winter, it is forced to cool to lower temperatures than in the north-more of the water vapour therefore condenses to form ice crystals, which then precipitate, thereby removing moisture from the air mass. Clearly, climate models must be able to reproduce this asymmetry if their predictions are to be credible. We also note that the asymmetry in water vapour implies an asymmetry in the production rate of the hydroxyl radical, and hence in the tropospheric chemistry of each hemisphere, for example in the rate of methane loss 5. C1 EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS,READING,BERKS,ENGLAND. RP KELLY, KK (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Tuck, Adrian/F-6024-2011 OI Tuck, Adrian/0000-0002-2074-0538 NR 24 TC 44 Z9 45 U1 0 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 SEP 19 PY 1991 VL 353 IS 6341 BP 244 EP 247 DI 10.1038/353244a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GF674 UT WOS:A1991GF67400054 ER PT J AU YAP, WT LOCASCIOBROWN, L PLANT, AL CHOQUETTE, SJ HORVATH, V DURST, RA AF YAP, WT LOCASCIOBROWN, L PLANT, AL CHOQUETTE, SJ HORVATH, V DURST, RA TI LIPOSOME FLOW-INJECTION IMMUNOASSAY - MODEL-CALCULATIONS OF COMPETITIVE IMMUNOREACTIONS INVOLVING UNIVALENT AND MULTIVALENT LIGANDS SO ANALYTICAL CHEMISTRY LA English DT Article ID BINDING; MEMBRANES; ASSAYS AB The use of liposomes as detectable reagents in solid-phase immunoassays has been explored in a flow injection immunoanalysis (FIIA) system. Model calculations are presented for FIIA based on the competitive binding of univalent analyte and multivalent liposomes to immobilized antibodies. Parameters such as binding constants, concentrations of liposomes and antibody, and steric hindrance are considered for their relative effects on detectable liposome signal response to analyte concentrations. Qualitative comparisons of the model with the experimental data are made. RP YAP, WT (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. RI Horvath, Viola/A-5158-2008 OI Horvath, Viola/0000-0003-1014-7930 NR 12 TC 32 Z9 33 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1991 VL 63 IS 18 BP 2007 EP 2011 DI 10.1021/ac00018a020 PG 5 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800020 PM 1750702 ER PT J AU MCKEOWN, PJ JOHNSTON, MV MURPHY, DM AF MCKEOWN, PJ JOHNSTON, MV MURPHY, DM TI ONLINE SINGLE-PARTICLE ANALYSIS BY LASER DESORPTION MASS-SPECTROMETRY SO ANALYTICAL CHEMISTRY LA English DT Letter ID INDIVIDUAL AEROSOL-PARTICLES; REAL-TIME MEASUREMENT; SURFACE-IONIZATION; AIRBORNE PARTICLES; DIRECT-INLET; SODIUM-CHLORIDE; AIR; SPECTROSCOPY; RESOLUTION C1 UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. NOAA,ERL,AERON LAB,BOULDER,CO 80303. RI Murphy, Daniel/J-4357-2012 OI Murphy, Daniel/0000-0002-8091-7235 NR 30 TC 122 Z9 122 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1991 VL 63 IS 18 BP 2069 EP 2073 DI 10.1021/ac00018a033 PG 5 WC Chemistry, Analytical SC Chemistry GA GE858 UT WOS:A1991GE85800033 ER PT J AU NADELLA, RK RAO, MV SIMONS, DS CHI, PH AF NADELLA, RK RAO, MV SIMONS, DS CHI, PH TI 0.4-3.0-MEV-RANGE BE-ION IMPLANTATIONS INTO INP-FE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DEPTH PROFILES; COMPOUND SEMICONDUCTORS; GAAS; SI; LAYER AB High-energy (MeV) Be implants in the energy range 0.4-3.0 MeV and dose range 2 x 10(13)-6 x 10(14) cm-2 were performed in InP:Fe. Phosphorus coimplantation was used at all Be implant energies and doses to minimize Be redistribution during annealing. For comparison, the Be implant alone was also performed at 1 MeV for a dose of 2 x 10(14) cm-2. The first four moments of the Be implant depth distributions were calculated from the secondary-ion-mass spectrometry (SIMS) data on the as-implanted samples. Variable temperature/time rapid thermal annealing (RTA) cycles were used to activate the Be implant. A maximum of 94% activation was obtained for 875-degrees-C/15-s RTA on the 2-MeV/2 x 10(14)-cm-2 Be implant. In contrast to Be-implanted samples, no in-diffusion of Be was observed in Be/P-coimplanted samples. For the annealed samples, two additional Be peaks located at 0.8R(p) and 0.9R(p) (range) were observed in the SIMS depth profiles. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP NADELLA, RK (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 26 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1991 VL 70 IS 6 BP 2973 EP 2978 DI 10.1063/1.349324 PG 6 WC Physics, Applied SC Physics GA GF539 UT WOS:A1991GF53900014 ER PT J AU ROBERTSON, B AF ROBERTSON, B TI MOBILITY VARIANCE DETERMINED FROM AC ELECTROPHORETIC LIGHT-SCATTERING SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PARTICLES AB The homodyne correlation function for light scattered from an aqueous suspension of particles in a uniform oscillating electric field is calculated assuming the mobility varies from particle to particle. The correlation function has an exponential decay that is modulated at frequency omega/2-pi with amplitude (q.E/omega)2 , where q is the scattering vector, E and omega/2-pi are the amplitude and frequency of the oscillating field, and is the variance of the mobility of the particles. The variance can be determined by fitting the theoretical correlation function to homodyne photon autocorrelation measurements. This technique has the advantage of insensitivity to convection of the particles from heating by the applied electric field. RP ROBERTSON, B (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 10 Z9 10 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 SEP 15 PY 1991 VL 95 IS 6 BP 3873 EP 3876 DI 10.1063/1.460794 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900001 ER PT J AU DUBS, RL JULIENNE, PS AF DUBS, RL JULIENNE, PS TI A MULTICHANNEL QUANTUM DEFECT HALF-COLLISION ANALYSIS OF K2 PHOTODISSOCIATION THROUGH THE B1-PI-U STATE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC ANGULAR-MOMENTUM; DIATOMIC-MOLECULES; CROSS-SECTIONS; NONADIABATIC THEORY; SCATTERING-THEORY; ALKALI ATOMS; POLARIZATION; TRANSITIONS; DISSOCIATION; ALIGNMENT AB Recent experiments by Zafiropulos et al. [Phys. Rev. Lett. 61, 1485 (1988)] indicate that K2 photodissociation through the B 1-PI-u state results in fluorescence polarization which is strongly dependent on excitation wavelength. To understand these results, we have studied the K2 system quantum mechanically using a half-collision analysis derived from the generalized form of multichannel quantum defect theory. This analysis factors the transition amplitudes into separate term representing absorption and final state interactions. An approximation called the adiabatic (a --> c)/recoil (c --> e) approximation is developed for the half-collision matrix which reproduces quantitatively the exact half-collision results projected from the close-coupled wave function. This specific approximation applies to the homonuclear molecule K2 because of the very long range of the excited state potential, which varies as 1/R3. The quantum mechanical expression for the polarization as a function of initial rotational quantum number J0 and total energy E is found to be extremely simple in this approximation, depending only on J0 and the single-channel P, Q, and R phase shifts for the adiabatic reference states corresponding to the B 1-PI-u state at short distance. In the high J limit, the quantum expression is in exact agreement with a semiclassical expression which is derived in the accompanying paper by Kleiber et al. RP DUBS, RL (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 38 TC 19 Z9 19 U1 2 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 SEP 15 PY 1991 VL 95 IS 6 BP 4177 EP 4187 DI 10.1063/1.460773 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF099 UT WOS:A1991GF09900034 ER PT J AU WINTER, A GOENAGA, C MAUL, GA AF WINTER, A GOENAGA, C MAUL, GA TI CARBON AND OXYGEN ISOTOPE TIME-SERIES FROM AN 18-YEAR CARIBBEAN REEF CORAL SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SCLERACTINIAN CORALS; SEA; FRACTIONATION; OCEAN; C-13 AB Colonies of Montastrea annularis live near La Parguera, Puerto Rico, and may be 700 years old. Time series from 1964 to 1982 of delta-C-13 and delta-O-18 from a continuous core of these corals are compared to an adjacent environmental record. At the intraannual level, delta-O-18 correlates well with water temperature. Changes in the amplitude of the delta-O-18 signal between 1967 and 1976 are attributed to sampling frequency but may be also due to environmental changes such as salinity. Average annual delta-O-18, delta-O-18 and sea surface temperature show similar trends for the period from 1964 to 1982 but especially from 1969 onwards. Changes in average annual values during this time interval are most likely due to water mass changes brought about by interannual variability of the North Atlantic circulation. Since water temperatures at La Parguera are representative of changes occurring in the wider Caribbean, the isotope record from La Parguera corals could be used as a proxy for large-scale environmental changes beyond the historical record through the Little Ice Age. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. UNIV PUERTO RICO,DEPT MARINE SCI,MAYAGUEZ,PR 00681. RP WINTER, A (reprint author), UNIV PUERTO RICO,DEPT BIOL,POB 5000,MAYAGUEZ,PR 00681, USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 21 TC 29 Z9 33 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1991 VL 96 IS C9 BP 16673 EP 16678 DI 10.1029/91JC01211 PG 6 WC Oceanography SC Oceanography GA GG239 UT WOS:A1991GG23900002 ER PT J AU LAVELLE, JW COKELET, ED CANNON, GA AF LAVELLE, JW COKELET, ED CANNON, GA TI A MODEL STUDY OF DENSITY INTRUSIONS INTO AND CIRCULATION WITHIN A DEEP, SILLED ESTUARY - PUGET SOUND SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ADVECTION TRANSPORT ALGORITHM; SMALL IMPLICIT DIFFUSION; OBSERVATORY INLET; FJORD; FLOW; CHANNEL AB A laterally averaged hydrodynamical model is used to investigate episodic intrusions of denser, more oceanic water across the shallow double-silled entrance of Puget Sound and the resulting circulation within the interior deep basin. Tidal, freshwater discharge and wind effects are also encompassed in model results. Model simulations were made of the 4-month period from December 1983 through March 1984. During that period, hourly measurements of currents and salinity were made at the estuary entrance and on four moorings in the interior basin. The first 60 days of salinity data were used with the model to choose rates of vertical turbulent mixing and the lag times between fresh water appearance at river gauges and its arrival in the main basin of the sound. Comparison of model results with the full 120 days of salinity and velocity data shows that the model incorporates the important circulation features of this estuary. The model was then used to study intrusions and mixing in the sill region. The model identifies these factors as controls on the occurrence and strength of intrusions: the trans-sill salinity gradient, the intensity of tidal stirring and mixing over the sills, the supply of fresher surface water resulting from river runoff, and the winds. Time series of salinities in the interior basin show local maxima following local maxima in the trans-sill salinity difference. Vertical transport in the sill region at both tidal and subtidal time scales is dominated by advection rather than diffusion. Though much of the vertical exchange occurs over the shallower sill, a depth depression between the two entrance sills appears to be the site of significant overturning. Downwelling of surface water occurs on the landward side of both sills. Substantial freshening of the interior basin occurs during the winter months because river discharges are large and are stirred downward in the sill region to be entrained into landward bottom flows. Extraordinarily large river discharges can suppress the effect of large trans-sill salinity differences with the effect of weakening potential intrusions. Winds can indirectly influence intrusions by longitudinally positioning fresher, river-influenced surface water in the sill region. Winds can directly influence intrusions via bottom compensation flows in Admiralty Inlet, with northward winds encouraging intrusions, and by changing salinities at the entrance to the sound, and thus the trans-sill salinity gradient. RP LAVELLE, JW (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,BLDG 3,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 47 TC 37 Z9 37 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1991 VL 96 IS C9 BP 16779 EP 16800 DI 10.1029/91JC01450 PG 22 WC Oceanography SC Oceanography GA GG239 UT WOS:A1991GG23900009 ER PT J AU ROBBINS, JA EADIE, BJ AF ROBBINS, JA EADIE, BJ TI SEASONAL CYCLING OF TRACE-ELEMENTS CS-137, BE-7, AND PU-239+240 IN LAKE-MICHIGAN SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GREAT-LAKES; SEDIMENT TRAP; CHEMICAL FLUXES; ORGANIC-CARBON; SARGASSO SEA; WATERS; SILICA; ACCUMULATION; DEPOSITION; PLANKTON AB Trace elements, fallout Cs-137(t1/2 = 30.2 years) and cosmogenic Be-7 (t1/2 = 53.4 days) were measured in trap samples collected from two sites in southern Lake Michigan at selected times during the period from 1982 through 1987. Concentrations of Cs-137 in trap material were virtually constant from top to bottom during the period when the lake was vertically well-mixed. Fluxes of Cs-137 were more than two orders of magnitude higher than atmospheric loading. With the development of the thermocyline, concentrations of the isotope diminished to undetectable levels at a rate indicating a 1-month residence time of resuspended components in the epilimnion. Declines in mass flux (10 to 0.2 g m-2 d-1) and trace element concentrations (some by 30 x) also occurred at this time. Epilimnetic concentration of Be-7 increased from a prestratification value of about 30 dpm/g to a maximum of about 120 dpm/g in July. During calcite formation in August, the concentration rapidly declined mainly as a result of enhanced particle settling rates. Throughout the period of stratification, a maximum in concentration and flux of Be-7 persisted in trap material between 40 and 60 m depth but only about 15% of the atmospheric flux was transferred to the benthic boundary region below 60 m. In near-bottom trap materials, the Cs-137 concentration was reduced at the onset of stratification by addition of radiocesium-deficient authigenic materials. By November, concentrations of Cs-137 had returned to prestratification levels through remineralization of these materials. A decrease of 22% in the seasonally invariant ratio of Cs-137/K-40 between 1982 and 1986 indicated a decay-corrected removal time of about 20 years, which is consistent with the rate of decrease of Pu concentrations in the well-mixed water column measured over more than a decade. In benthic trap samples, Be-7 concentration decreased exponentially throughout the stratified period, with a time constant comparable to the half-life of the isotope. The resuspendable sediment pool, evidently isolated from atmospheric loading during stratification, was "recharged" with Be-7 following late fall overtum. Box and advection-diffusion models describing the storage and vertical distribution of Be-7 during the winter-mixing period successfully account for observations, implying an inverse relation between water depth and winter recharging of the resuspendable pool. A plutonium-calibrated box model for the seasonal cycle of tracers in surface waters describes the main features of the variation of Pu isotopes, Cs-137 and Be-7. RP ROBBINS, JA (reprint author), US DEPT COMMERCE,NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 62 TC 68 Z9 68 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1991 VL 96 IS C9 BP 17081 EP 17104 DI 10.1029/91JC01412 PG 24 WC Oceanography SC Oceanography GA GG239 UT WOS:A1991GG23900030 ER PT J AU BOULDIN, CE FORMAN, RA BELL, MI DONOVAN, EP AF BOULDIN, CE FORMAN, RA BELL, MI DONOVAN, EP TI STRUCTURAL RELAXATION IN ION-DAMAGED AMORPHOUS-GERMANIUM SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; ELECTRON-YIELD; SILICON; EXAFS; GE AB X-ray and optical studies of ion-damaged amorphous germanium reveal a structural relaxation produced by low-temperature (200-degrees-C) annealing. This relaxation appears to be qualitatively different from that observed previously at higher annealing temperatures (250-500-degrees-C). Extended x-ray-absorption fine-structure measurements, made in the total-electron-yield mode with a sampling depth of 600-800 angstrom, indicate a sharpening of the first shell in the radial distribution, but no change in the first-shell distance or coordination number. No higher shells in the radial distribution are observed, before or after annealing, indicating that these shells remain highly disordered. Infrared-reflection and Raman-scattering measurements confirm that a relaxation takes place and that there is no nucleation of microcrystals in the implanted layer within the detection limit of 1.5% volume fraction. In contrast to previous studies, the present results exhibit no evidence of a reduction in bond-angle disorder. C1 USN,RES LAB,DIV CONDENSED MATTER & RADIAT SCI,WASHINGTON,DC 20375. RP BOULDIN, CE (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 20 TC 10 Z9 10 U1 3 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5492 EP 5496 DI 10.1103/PhysRevB.44.5492 PG 5 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300013 ER PT J AU SHIH, A HOR, C ELAM, W KIRKLAND, J MUELLER, D AF SHIH, A HOR, C ELAM, W KIRKLAND, J MUELLER, D TI SURFACE GEOMETRY OF BAO ON W(100) - A SURFACE-EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE STUDY SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON RADIATION; ELECTRONIC-PROPERTIES; W(001); PHASE; SPECTROSCOPY; AMPLITUDE AB A surface-extended x-ray-absorption fine-structure study of ordered monolayers of coadsorbed barium and oxygen on a single-crystal W(100) surface is described. A (square-root 2 X square-root 2)R45-degrees structure with a stoichiometric barium-to-oxygen ratio, and a (2 square-root 2 X square-root 2)R45-degrees structure with a nearly 1:2 barium-to-oxygen atomic ratio both form on W(100). The surface-extended x-ray-absorption fine-structure results indicate that all the barium and oxygen atoms are nearly coplanar in the (square-root 2 X square-root 2)R 45-degrees overlayer. The Ba-to-O distance in this overlayer is 3.20 +/- 0.05 angstrom and beta = 82-degrees +/- 5-degrees, where beta is the angle between the Ba-O internuclear axis and the surface normal. For the (2 square-root 2 X square-root 2)R 45-degrees overlayer, there are two types of oxygen sites. Oxygen atoms nearly coplanar with the barium atoms are also present in these films with a Ba-to-O distance of 3.27 +/- 0.05 angstrom and beta = 75 +/- 4-degrees. Additional oxygen atoms lie outside the barium plane at a distance 2.03 +/- 0.05 angstrom and beta = 23 +/- 10-degrees from the nearest barium atoms. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP SHIH, A (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 27 TC 10 Z9 10 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5818 EP 5826 DI 10.1103/PhysRevB.44.5818 PG 9 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300057 ER PT J AU WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ AF WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ TI INSULATING CS OVERLAYER ON INSB(110) SO PHYSICAL REVIEW B LA English DT Note ID SCANNING-TUNNELING-MICROSCOPY; III-V-SEMICONDUCTORS; GAAS(110) SURFACE; ELECTRONIC-STRUCTURE; SI(111)2X1 SURFACE; METAL TRANSITION; SB OVERLAYERS; 110 SURFACES; SPECTROSCOPY; STATES AB Cesium overlayers on room-temperature InSb(110) have been studied with scanning tunneling microscopy and spectroscopy. A two-dimensional (2D) overlayer is observed, consisting of four-atom, Cs(110)-like planar clusters arranged in a c(2 x 6) superlattice. Interestingly, current-versus-voltage (I-V) spectra exhibit a band gap of almost-equal-to 0.6 eV, larger than the substrate band gap of almost-equal-to 0.15 eV. The I-V spectra are very similar to those observed on the similar 2D overlayer on GaAs (110), suggesting that the measured gap is a property of the 2D Cs film. The possible origins of this insulating behavior are discussed. RP WHITMAN, LJ (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Whitman, Lloyd/G-9320-2011 OI Whitman, Lloyd/0000-0002-3117-1174 NR 29 TC 36 Z9 36 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1991 VL 44 IS 11 BP 5951 EP 5954 DI 10.1103/PhysRevB.44.5951 PG 4 WC Physics, Condensed Matter SC Physics GA GF443 UT WOS:A1991GF44300082 ER PT J AU PASTEL, RL HAGER, GD MILLER, HC LEONE, SR AF PASTEL, RL HAGER, GD MILLER, HC LEONE, SR TI EFFICIENT BR-STAR LASER PUMPED BY FREQUENCY-DOUBLED ND-YAG AND ELECTRONIC-TO-VIBRATIONAL TRANSFER-PUMPED CO2 AND HCN LASERS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ENERGY-TRANSFER; ABSORPTION-SPECTROSCOPY; DEACTIVATION; ATOMS; IBR AB A photolytic, repetitively pulsed Br(4 2P1/2-4 2P3/2) laser at 2.714-mu-m is demonstrated by photodissociation of IBr at 532 nm using a frequency-doubled Nd:YAG pump laser. Pulse energies of 3 mJ at 10 Hz are achieved, resulting in a maximum pump energy conversion efficiency of 1.5%. We also demonstrate lasing on ro-vibrational transitions of CO2 at 4.3-mu-m and HCN at 3.9-mu-m by electronic-to-vibrational transfer from photolytically generated Br*. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,JOINT INST LAB,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP PASTEL, RL (reprint author), PHILLIPS LAB,IODINE LASER TECH SECT,KIRTLAND AFB,NM 87117, USA. NR 15 TC 9 Z9 9 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 SEP 13 PY 1991 VL 183 IS 6 BP 565 EP 569 DI 10.1016/0009-2614(91)80176-X PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF961 UT WOS:A1991GF96100017 ER PT J AU COOK, E BIRD, T PETERSON, M BARBETTI, M BUCKLEY, B DARRIGO, R FRANCEY, R TANS, P AF COOK, E BIRD, T PETERSON, M BARBETTI, M BUCKLEY, B DARRIGO, R FRANCEY, R TANS, P TI CLIMATIC-CHANGE IN TASMANIA INFERRED FROM A 1089-YEAR TREE-RING CHRONOLOGY OF HUON PINE SO SCIENCE LA English DT Article ID SURFACE AIR-TEMPERATURE; NEW-ZEALAND AB A climatically sensitive huon pine tree-ring chronology from western Tasmania allows inferences about Austral summer temperature change since A.D. 900. Since 1965, huon pine growth has been unusually rapid for trees that are in many cases over 700 years old. This growth increase correlates well with recent anomalous warming in Tasmania on the basis of instrumental records and supports claims that a climatic change, perhaps influenced by greenhouse gases, is in progress. Although this temperature increase exceeds any that are inferred to have occurred during the past 1089 years at this location, it has not yet clearly emerged from the natural background variability of climate in this part of the Southern Hemisphere. C1 TASMANIAN TRADES & LABOUR COUNCIL,FORESTRY UNIT,NEWTOWN,TAS 7008,AUSTRALIA. TASMANIA FORESTRY COMMISS,HOBART,TAS 7001,AUSTRALIA. CSIRO,DIV ATMOSPHER RES,MORDIALLOC,VIC 3195,AUSTRALIA. UNIV SYDNEY,NWG MACINTOSH CTR,SYDNEY,NSW 2006,AUSTRALIA. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80309. RP COOK, E (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,TREE RING LABS,PALISADES,NY 10964, USA. NR 21 TC 89 Z9 109 U1 1 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 13 PY 1991 VL 253 IS 5025 BP 1266 EP 1268 DI 10.1126/science.253.5025.1266 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GE689 UT WOS:A1991GE68900036 PM 17831445 ER PT J AU CLAIRON, A SALOMON, C GUELLATI, S PHILLIPS, WD AF CLAIRON, A SALOMON, C GUELLATI, S PHILLIPS, WD TI RAMSEY RESONANCE IN A ZACHARIAS FOUNTAIN SO EUROPHYSICS LETTERS LA English DT Article DE OPTICAL COOLING OF ATOMS; TRAPPING; TIME AND FREQUENCY MEASUREMENT; QUANTUM OPTICS ID OPTICAL MOLASSES; RADIATION PRESSURE; MULTILEVEL ATOMS; DOPPLER LIMIT; BEAM; SPECTROSCOPY; PROSPECTS AB We report a realization of Zacharias's 1953 proposal for observing a Ramsey resonance in an atomic fountain. Launched upward from a moving optical molasses where they have been cooled to approximately 5-mu-K, cesium atoms pass once through a microwave cavity, continue to the summit of their trajectory, then fall again through the same cavity, completing the separated-fields interaction. The atoms spend 0.25 s in free flight above the cavity. Linewidth (2 Hz) and S/N imply a stability of 3.10(-12)-tau--1/2, at least as good as in existing Cs clocks, with eventual expected improvements of 10(2). C1 ECOLE NORM SUPER,DEPT PHYS,SPECT HERTZIENNE LAB,F-75231 PARIS 05,FRANCE. LAB AIMEE COTTON,F-91405 ORSAY,FRANCE. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CLAIRON, A (reprint author), LAB PRIMAIRE TEMPS & FREQUENCES,61 AVE OBSERV,F-75014 PARIS,FRANCE. NR 30 TC 165 Z9 169 U1 2 U2 17 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP 7 PY 1991 VL 16 IS 2 BP 165 EP 170 DI 10.1209/0295-5075/16/2/008 PG 6 WC Physics, Multidisciplinary SC Physics GA GE678 UT WOS:A1991GE67800008 ER PT J AU WARREN, R GIERCZAK, T RAVISHANKARA, AR AF WARREN, R GIERCZAK, T RAVISHANKARA, AR TI A STUDY OF O(D-1) REACTIONS WITH CFC SUBSTITUTES SO CHEMICAL PHYSICS LETTERS LA English DT Article ID YIELDS; O-3; NM AB The rate coefficients for the removal of O(1D) by reaction with the following nine CFC substitutes have been measured using time-resolved vacuum UV atomic resonance fluorescence detection of O(3P): CHF2Cl (HCFC 22), CF3CHCl2 (HCFC 123), CF3CHClF (HCFC 124), CF3CHF2(HFC 125), CF3CH2Cl (HCFC 133a), CF3CH2F (HFC 134a), CH3CFCl2 (HCFC 141b), CH3CF2Cl (HCFC 142b), and CH3CHF2 (HFC 152a). The branching ratios for the quenching of O(1D) to O(3P) by the above molecules were determined by measuring the O(3P) yields in the presence of the HCFC/HFCs relative to that in the presence of N2. By difference, the rate coefficients for the chemical reaction of O(1D) with the HCFC/HFCs were calculated. C1 NOAA,ERL,R-E AL2,325 BROADWAY,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80303. RI Ravishankara, Akkihebbal/A-2914-2011 NR 22 TC 36 Z9 36 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 SEP 6 PY 1991 VL 183 IS 5 BP 403 EP 409 DI 10.1016/0009-2614(91)90402-U PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GF695 UT WOS:A1991GF69500017 ER PT J AU BRYANT, WR SIMMONS, GR GRIMM, P AF BRYANT, WR SIMMONS, GR GRIMM, P TI THE MORPHOLOGY AND EVOLUTION OF BASINS ON THE CONTINENTAL-SLOPE, NORTHWEST GULF OF MEXICO SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Meeting Abstract C1 TEXAS A&M UNIV SYST,COLLEGE STN,TX 77843. NOAA,WASHINGTON,DC 20230. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD SEP PY 1991 VL 75 IS 9 BP 1517 EP 1518 PG 2 WC Geosciences, Multidisciplinary SC Geology GA GD155 UT WOS:A1991GD15500024 ER PT J AU BENTZ, DP GARBOCZI, EJ AF BENTZ, DP GARBOCZI, EJ TI SIMULATION STUDIES OF THE EFFECTS OF MINERAL ADMIXTURES ON THE CEMENT PASTE-AGGREGATE INTERFACIAL ZONE SO ACI MATERIALS JOURNAL LA English DT Article DE CEMENT-AGGREGATE REACTIONS; CEMENT PASTES; CONCRETES; FLY ASH; POZZOLANS; SILICA FUME ID SILICA-FUME; MICROSTRUCTURE; BOND AB In concrete, the interfacial zone between cement paste and aggregate plays a critical role in determining mechanical performance. In recent years, high-performance concretes have been produced based on a low water-cement ratio cement paste containing a superplasticizer and silica fume. One of the key benefits of silica fume is its ability to improve the integrity of the interfacial zone in concrete. This paper presents a three-dimensional microstructural model for simulating the interfacial zone in concrete, including the incorporation of inert and pozzolanic mineral admixtures. The model is used to obtain the cementitious-material phase distributions as a function of distance from the aggregate surface to quantitatively characterize the interfacial zone. Pozzolanic admixtures, such as silica fume and fly ash, are found to increase the homogeneity of the interfacial region, with the most important enhancement proposed to be the improved homogeneity of the calcium-silicate-hydrate phase. The effects of mineral admixture particle size and reactivity are also computed via simulations. Simulation results are compared to conventional experimental measurements, such as compressive strength, and scanning electron micrographic investigations of the microstructure of actual cement-based materials. C1 NATL SCI FDN,CTR SCI & TECHNOL ADV CEMENT BASED MAT,WASHINGTON,DC. RP BENTZ, DP (reprint author), NATL INST STAND & TECHNOL,DIV BLDG MAT,GAITHERSBURG,MD, USA. NR 30 TC 62 Z9 65 U1 1 U2 1 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD SEP-OCT PY 1991 VL 88 IS 5 BP 518 EP 529 PG 12 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA GJ820 UT WOS:A1991GJ82000016 ER PT J AU CARINO, NJ AF CARINO, NJ TI EARLY-AGE CONCRETE STRENGTH PREDICTION BY MATURITY - ANOTHER LOOK - DISCUSSION SO ACI MATERIALS JOURNAL LA English DT Discussion RP CARINO, NJ (reprint author), NATL INST STAND & TECHNOL,RES CIVIL ENGN,GAITHERSBURG,MD, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD SEP-OCT PY 1991 VL 88 IS 5 BP 584 EP 586 PG 3 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA GJ820 UT WOS:A1991GJ82000021 ER PT J AU PRASK, HJ AF PRASK, HJ TI NEUTRON PROBES TACKLE INDUSTRIAL-PROBLEMS SO ADVANCED MATERIALS & PROCESSES LA English DT Article RP PRASK, HJ (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,MAT SCI & ENGN LAB,BLDG 235,ROOM E151,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD SEP PY 1991 VL 140 IS 3 BP 26 EP & PG 0 WC Materials Science, Multidisciplinary SC Materials Science GA GF325 UT WOS:A1991GF32500004 ER PT J AU GARDNER, WS HERCHE, LR STJOHN, PA SEITZINGER, SP AF GARDNER, WS HERCHE, LR STJOHN, PA SEITZINGER, SP TI HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF [(NH4)-N-15-[(NH4)-N-14+(NH4)-N-15] ION RATIOS IN SEAWATER FOR ISOTOPE-DILUTION EXPERIMENTS SO ANALYTICAL CHEMISTRY LA English DT Article ID RELATIVE N-15 ABUNDANCE; NATURAL-WATERS; AMMONIUM; REGENERATION; NITROGEN; EXTRACTION; RECOVERY; RATES; BAY AB A liquid chromatographic method with fluorometric detection, after postcolumn labeling with o-phthalaldehyde/2-mercaptoethanol reagent, was developed to directly quantify (NH4)-N-15:[(NH4)-N-15 + (NH4)-N-15] ion ratios in aqueous samples that had been enriched with (NH4)-N-15 for isotope dilution experiments. Cation-exchange chromatography, with a sodium borate buffer mobile phase, was selected as the separation mode because the two isotopes have slightly different constants in the equilibrium reaction between ammonium ion and ammonia. When the two forms of ammonium were passed separately through a high-performance cation-exchange column under precisely controlled chromatographic conditions, the retention time (RT) of (NH4)-N-15 was 1.012 times the RT of (NH4)-N-15. The two isotopic forms of ammonium ion were not resolved into separate peaks when they were injected together, but the retention time of the combined peak, as defined by an integrator, increased with increasing percentages of (NH4)-N-15 in the mixture. The relationship of RT shift vs percentage of (NH4)-N-15 relative to total ammonium followed a sigmold-shaped curve with the maximum RT shifts per change in isotopic composition occurring between 25 and 75% (NH4)-N-15. Using a calibration curve based on this relationship and a solution of separately injected (NH4)-N-14 in mobile-phase buffer as an "internal standard", we were able to directly determine the concentrations and ratios of the two isotopes in enriched seawater. C1 ST JOHN ASSOCIATES INC,BELTSVILLE,MD 20705. ACAD NAT SCI PHILADELPHIA,DIV ENVIRONM RES,PHILADELPHIA,PA 19103. RP GARDNER, WS (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 34 TC 28 Z9 28 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1991 VL 63 IS 17 BP 1838 EP 1843 DI 10.1021/ac00017a031 PG 6 WC Chemistry, Analytical SC Chemistry GA GC931 UT WOS:A1991GC93100032 ER PT J AU CHABALA, JM LEVISETTI, R SONI, KK WILLIAMS, DB NEWBURY, DE AF CHABALA, JM LEVISETTI, R SONI, KK WILLIAMS, DB NEWBURY, DE TI SECONDARY ION IMAGING OF THE DISTRIBUTION OF DELTA' (AL3LI) IN AL-LI ALLOYS SO APPLIED SURFACE SCIENCE LA English DT Article ID ALUMINUM-LITHIUM ALLOYS; MASS-SPECTROMETRY; RESOLUTION AB A high resolution scanning ion microprobe has been used, in conjunction with transmission electron microscopy, to study the distribution of the metastable delta' (Al3Li) phase in Al-Li alloys. Various secondary ions were used for chemical imaging (lateral resolution approximately 80 nm) and their contrast aspects and formation mechanisms are discussed. delta' particles appeared dark in the Al-27+, Li-7+ and (AlLi+)-Al-34 distribution maps despite their higher Li content than the alpha-matrix (aluminum-lithium solid-solution). Maps generated from two molecular ions, 14Li2+ and 41Li2+Al+, exhibited true chemical contrast in the images: the delta' precipitates appeared bright in accordance with the known Li distribution. Using retrospective image analysis, measurements were made of the secondary ion intensities displayed by the delta' particles and the alpha-matrix. Efforts to calibrate the secondary ion intensities for quantitative analysis are also described. The unusual ion formation mechanism from delta' precipitates illustrates the coupled channel model of secondary particle emission: the observed favored emission of Li2 causes Li emission to be depressed. C1 LEHIGH UNIV,DEPT MAT SCI & ENGN,BETHLEHEM,PA 18015. UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP CHABALA, JM (reprint author), UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637, USA. NR 19 TC 8 Z9 8 U1 1 U2 2 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 SEP PY 1991 VL 51 IS 3-4 BP 185 EP 192 DI 10.1016/0169-4332(91)90401-5 PG 8 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA GG659 UT WOS:A1991GG65900009 ER PT J AU KAHLER, S AF KAHLER, S TI CORONAL MASS EJECTIONS AND STREAMERS ASSOCIATED WITH THE NEW CYCLE ACTIVE REGIONS AT SOLAR MINIMUM SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, CORONA; SUN, PARTICLE EMISSION ID MAGNETIC-FIELD; TRANSIENTS; ONSET AB We use data from the coronagraph/polarimeter on the SMM spacecraft to examine the coronal streamers and coronal mass ejections (CMEs) associated with the appearance of the high-latitude, new-cycle active regions at the beginning of solar cycle 22 in 1986 and 1987. Short-lived active regions, those lasting less than a disk passage, were not associated with streamers or CMEs. CMEs were generally associated with a high-latitude region only when another strong active region lay within approximately 30-degrees of the longitude of the high-latitude region. The CMEs appeared to arise from magnetic connections between the high-latitude regions and low-latitude, old-cycle regions or between the high-latitude regions of opposite hemisphere. The development of streamers over the active regions appeared to be independent of the occurrence of CMEs. In some cases streamers formed over active regions with which no CMEs were observed, and in other cases CMEs were associated with regions with no overlying streamers. Streamers were also observed to survive CMEs associated with the underlying active regions. RP NOAA, SPACE ENVIRONM LAB, AFGL, PHG, BEDFORD, MA 01731 USA. NR 28 TC 23 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 SEP 1 PY 1991 VL 378 IS 1 BP 398 EP 406 DI 10.1086/170439 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GC363 UT WOS:A1991GC36300040 ER PT J AU CHRISTENSENDALSGAARD, J GOUGH, DO THOMPSON, MJ AF CHRISTENSENDALSGAARD, J GOUGH, DO THOMPSON, MJ TI THE DEPTH OF THE SOLAR CONVECTION ZONE SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, ABUNDANCES; SUN, INTERIOR; SUN, OSCILLATIONS ID OSCILLATION FREQUENCIES; STELLAR EVOLUTION; MAGNETIC-FIELD; DIFFUSION; EQUATION; INTERIOR; STATE; MODELS; ENVELOPES; OVERSHOOT AB The transition of the temperature gradient between being subadiabatic and adiabatic at the base of the solar convection zone gives rise to a clear signature in the sound speed. Helioseismic measurements of the sound speed therefore permit a determination of the location of the base of the convection zone. We have tested two techniques by applying them to artificial data, obtained by adding simulated noise to frequencies computed from two different solar models. The determinations appear to be relatively insensitive to uncertainties of the physics of the solar interior, although, if present, a large-scale megagauss magnetic field or some other phenomenon not normally incorporated into theoretical models at the base of the convection zone might have a significant effect on the results. On the assumption that this is not the case, we conclude, from an analysis of observed frequencies of solar oscillation, that the depth of the solar convection zone is (0.287 +/- 0.003) solar radii. C1 UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE,ENGLAND. UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE,ENGLAND. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RP CHRISTENSENDALSGAARD, J (reprint author), AARHUS UNIV,INST ASTRON,DK-8000 AARHUS,DENMARK. NR 80 TC 298 Z9 299 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 1991 VL 378 IS 1 BP 413 EP 437 DI 10.1086/170441 PN 1 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GC363 UT WOS:A1991GC36300042 ER PT J AU KAIMAI, JC GAYNOR, JE AF KAIMAI, JC GAYNOR, JE TI ANOTHER LOOK AT SONIC THERMOMETRY SO BOUNDARY-LAYER METEOROLOGY LA English DT Note ID ANEMOMETER; HEAT AB In this note we reassess the role of sonic thermometry in boundary-layer studies. The sonic temperature signal, when corrected for crosswind velocity contamination, very closely approximates the virtual temperature of air. This variable is needed for many boundary-layer calculations. We describe preliminary tests with a new sonic anemometer-thermometer that performs the velocity correction in real time. Our test results offer new insights into the nature of the velocity error on temperature standard deviations and fluxes. They also draw attention to the high noise threshold that appears as an f+1 rise in the fS(f) spectrum when spectral levels drop below 10(-4)-degrees-C2. RP KAIMAI, JC (reprint author), NOAA,ERL,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 13 TC 193 Z9 207 U1 0 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD SEP PY 1991 VL 56 IS 4 BP 401 EP 410 DI 10.1007/BF00119215 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB669 UT WOS:A1991GB66900006 ER PT J AU ROPER, CFE VECCHIONE, M SWEENEY, MJ AF ROPER, CFE VECCHIONE, M SWEENEY, MJ TI VOSS,GILBERT,L. MEMORIAL ISSUE - FOREWORD SO BULLETIN OF MARINE SCIENCE LA English DT Editorial Material C1 NOAA,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,NATL MUSEUM NAT HIST,WASHINGTON,DC 20560. RP ROPER, CFE (reprint author), NATL MUSEUM NAT HIST,DEPT INVERTEBRATE ZOOL,WASHINGTON,DC 20560, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 1991 VL 49 IS 1-2 BP 3 EP 4 PG 2 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HC568 UT WOS:A1991HC56800002 ER PT J AU VECCHIONE, M AF VECCHIONE, M TI A METHOD FOR EXAMINING THE STRUCTURE AND CONTENTS OF THE DIGESTIVE-TRACT IN PARALARVAL SQUIDS SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT GILBERT L VOSS INTERNATIONAL SYMP AT THE 1990 ANNUAL MEETING OF THE AMERICAN MALACOLOGICAL UNION CY JUN 03-07, 1990 CL MARINE BIOL LAB, WOODS HOLE, MA SP AMER MALACOL UNION, CEPHALOPOD INT ADVISORY COUNCIL HO MARINE BIOL LAB ID LOLIGO-PEALEI; PREDATION; LARVAE; EGGS; FISH; WATERS AB Starvation resulting from failure to feed successfully after absorption of the yolk reserves has been proposed to be a major source of pre-recruitment mortality in squids. To test this hypothesis, methods must be developed to determine whether paralarvae have fed successfully at sea. When paralarvae are stained with Alcian Blue and then cleared with trypsin, the entire digestive tract can be examined intact for the presence of food. This method was used for Abralia trigonura and Sthenoteuthis oualaniensis paralarvae from Hawaiian waters. Approximately 9% of the former and 16% of the latter contained recognizable food material, mostly crustacean fragments. Food was found in the stomach, caecum, and intestine. The smallest specimen of A. trigonura with recognizable food in its digestive tract was 2.2 mm dorsal mantle length (DML), while for S. oualaniensis the smallest was 5.2 mm DML. The method is also useful for visualizing the ontogeny of the digestive-tract organs, beaks and radula, and other organs such as statocysts and eyes. RP VECCHIONE, M (reprint author), NOAA,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,NATL MUSEUM NAT HIST,WASHINGTON,DC 20560, USA. NR 41 TC 33 Z9 33 U1 0 U2 1 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 1991 VL 49 IS 1-2 BP 300 EP 308 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HC568 UT WOS:A1991HC56800026 ER PT J AU VECCHIONE, M ROPER, CFE AF VECCHIONE, M ROPER, CFE TI CEPHALOPODS OBSERVED FROM SUBMERSIBLES IN THE WESTERN NORTH-ATLANTIC SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT GILBERT L VOSS INTERNATIONAL SYMP AT THE 1990 ANNUAL MEETING OF THE AMERICAN MALACOLOGICAL UNION CY JUN 03-07, 1990 CL MARINE BIOL LAB, WOODS HOLE, MA SP AMER MALACOL UNION, CEPHALOPOD INT ADVISORY COUNCIL HO MARINE BIOL LAB ID COUNTER-ILLUMINATION; MIDWATER ANIMALS; SQUID; BIOLUMINESCENCE; FISHES; SEA AB Records of 158 observations of cephalopods from submersibles, primarily the JOHNSON SEA-LINK, have been compiled through collaboration with several investigators. These observations include 118 videotape sequences, 58 collected specimens, and numerous shipboard photographs of live animals. At least 33 species have been observed to date; a few species have been observed repeatedly and could be good subjects for directed studies. The methods developed for in situ observation and subsequent collection of specimens with little or no damage allow descriptions of behavior, morphology, physiology, and distribution that are not possible with other methods of collecting. C1 NATL MUSEUM NAT HIST,DEPT INVERTEBRATE ZOOL,WASHINGTON,DC 20560. RP VECCHIONE, M (reprint author), NATL MARINE FISHERIES SERV,SYSTEMAT LAB,NATL MUSEUM NAT HIST,WASHINGTON,DC 20560, USA. NR 48 TC 55 Z9 55 U1 1 U2 6 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 1991 VL 49 IS 1-2 BP 433 EP 445 PG 13 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HC568 UT WOS:A1991HC56800039 ER PT J AU MONINGER, WR BULLAS, J DELORENZIS, B ELLISON, E FLUECK, J MCLEOD, JC LUSK, C LAMPRU, PD PHILLIPS, RS ROBERTS, WF SHAW, R STEWART, TR WEAVER, J YOUNG, KC ZUBRICK, SM AF MONINGER, WR BULLAS, J DELORENZIS, B ELLISON, E FLUECK, J MCLEOD, JC LUSK, C LAMPRU, PD PHILLIPS, RS ROBERTS, WF SHAW, R STEWART, TR WEAVER, J YOUNG, KC ZUBRICK, SM TI SHOOTOUT 89 - A COMPARATIVE-EVALUATION OF KNOWLEDGE-BASED SYSTEMS THAT FORECAST SEVERE WEATHER SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB During the summer of 1989, the Forecast Systems Laboratory of the National Oceanic and Atmospheric Administration sponsored an evaluation of artificial-intelligence-based systems that forecast severe convective storms. The evaluation experiment, called Shootout-89, took place in Boulder, Colorado, and focused on storms over the northeastern Colorado foothills and plains. Six systems participated in Shootout-89: three traditional expert systems, a hybrid system including a linear model augmented by a small expert system, an analogue-based system, and a system developed using methods from the cognitive science/judgment analysis tradition. Each day of the exercise, the systems generated 2-9-h forecasts of the probabilities of occurrence of nonsignificant weather, significant weather, and severe weather in each of four regions in northeastern Colorado. A verification coordinator working at the Denver Weather Service Forecast Office gathered ground-truth data from a network of observers. The systems were evaluated on several measures of forecast skill, on timeliness, on ease of learning, and on ease of use. They were generally easy to operate; however, they required substantially different levels of meteorological expertise on the part of their users, reflecting the various operational environments for which they had been designed. The systems varied in their statistical behavior, but on this difficult forecast problem, they generally showed a skill approximately equal to that of persistence forecasts and climatological forecasts. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV NEVADA,ENVIRONM RES CTR,LAS VEGAS,NV 89154. CONSULTANTS CHOICE INC,ATLANTA,GA 30350. COLORADO STATE UNIV,NOAA,NESDIS,RAM BRANCH,FT COLLINS,CO 80523. SUNY ALBANY,CTR POLICY RES,ALBANY,NY 12222. ATMOSPHER ENVIRONM SERV,ARCTIC WEATHER CTR,EDMONTON T6B 2X3,ALBERTA,CANADA. ATMOSPHER ENVIRONM SERV,FORECAST RES DIV,TORONTO M3H 5T4,ONTARIO,CANADA. MICRO FORECASTS INC,PORTLAND,OR 97204. NOAA,NATL WEATHER SERV,OFF METEOROL,SILVER SPRING,MD 20910. RP MONINGER, WR (reprint author), NOAA,FORECAST SYST LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI moninger, william/G-4910-2015 OI moninger, william/0000-0003-0716-4721 NR 15 TC 7 Z9 7 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 SEP PY 1991 VL 72 IS 9 BP 1339 EP 1354 DI 10.1175/1520-0477(1991)072<1339:SACEOK>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GK190 UT WOS:A1991GK19000002 ER PT J AU BALSLEY, BB CARTER, DA RIDDLE, AC ECKLUND, WL GAGE, KS AF BALSLEY, BB CARTER, DA RIDDLE, AC ECKLUND, WL GAGE, KS TI ON THE POTENTIAL OF VHF WIND PROFILERS FOR STUDYING CONVECTIVE PROCESSES IN THE TROPICS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VERTICAL VELOCITY EVENTS; MOTIONS; ATMOSPHERE; GATE AB In this paper we provide a set of examples to demonstrate the potential of VHF radar wind profilers for studying tropical convection processes. Our examples were extracted from data obtained from the NOAA/CU Pacific Profiler Network, which has been in operation for a number of years and is currently being expanded. C1 NOAA,AERON LAB,BOULDER,CO 80303. RP BALSLEY, BB (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 14 TC 7 Z9 7 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 SEP PY 1991 VL 72 IS 9 BP 1355 EP 1360 DI 10.1175/1520-0477(1991)072<1355:OTPOVW>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GK190 UT WOS:A1991GK19000003 ER PT J AU LEWIS, JM MADDOX, RA AF LEWIS, JM MADDOX, RA TI THE SUMMER EMPLOYMENT PROGRAM AT NOAAS NATIONAL SEVERE STORMS LABORATORY - AN EXPERIMENT IN THE SCIENTIFIC MENTORSHIP OF UNDERGRADUATES SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB In an effort to encourage college students to consider careers in scientific research, NOAA's National Severe Storms Laboratory has instituted a Summer Employment Program. The program is centered around a scientific mentorship experience that matches each student with a laboratory scientist. During the nominal 12 weeks of the program, the scientist leads and directs a research project that is designed to be commensurate with the student's background. Along with the research experience, there is an educational component that encompasses both classroom work and experimentation. Additionally, students are introduced to a variety of research efforts in the laboratory through a continuing series of guest lectures by lab scientists. The program has operated in 1987, 1989, and 1990, and has included 17 students, 12 of whom have come from under-represented groups in our society. We report on the evolution of the program and scrutinize the results after these three years of effort. RP LEWIS, JM (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,NORMAN,OK 73069, USA. NR 11 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1991 VL 72 IS 9 BP 1362 EP 1372 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GK190 UT WOS:A1991GK19000004 ER PT J AU SULLIVAN, PJ AF SULLIVAN, PJ TI STOCK ABUNDANCE ESTIMATION USING DEPTH-DEPENDENT TRENDS AND SPATIALLY CORRELATED VARIATION SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ROBUST AB Hydroacoustic data commonly contain a large number of observations that are correlated in space and time. Such data are complicated to analyze, and a good estimate of the error in abundance is often difficult to obtain. Hydroacoustic data collected on Shelikof Strait walleye pollock (Theragra chalcogramma) are used to develop statistical techniques for analyzing survey data containing spatial trends and spatial correlations. The data show a trend in fish density with depth, while detrended observations exhibit spatial correlations. Spatial means and variances of fish density, and total abundance and its variance, are determined using the geostatistical theory of kriging. The total abundance estimate is the same order of magnitude as estimates arrived at using a stratified estimation approach. Detrending the data with respect to depth through depth stratification decreased the estimated variance by nearly a factor of 10. Detrending the data with respect to depth and kriging the residual variation over space reduced the variance by an additional factor of 2. Modeling trends and making more efficient use of the data contribute to the gain in information. C1 NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. NR 13 TC 36 Z9 38 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1991 VL 48 IS 9 BP 1691 EP 1703 DI 10.1139/f91-201 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GH594 UT WOS:A1991GH59400012 ER PT J AU BUTLER, JL AF BUTLER, JL TI MORTALITY AND RECRUITMENT OF PACIFIC SARDINE, SARDINOPS-SAGAX-CAERULEA, LARVAE IN THE CALIFORNIA CURRENT SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ANCHOVY ENGRAULIS-MORDAX; NORTHERN ANCHOVY; EGG CANNIBALISM; JACK MACKEREL; FISH LARVAE; PREDATION; MODEL; SEA; VARIABILITY; POPULATION AB The mortality rates of Pacific sardine, Sardinops sagax caerulea, larvae (< 20 d) increased during 1951-67, and this increase was positively correlated with the increase in biomass of northern anchovy, Engraulis mordax. Other potential correlates with larval sardine mortality rates were examined using multiple correlation. These included temperature and zooplankton volumes at stations positive for sardine larvae, water column stability, upwelling, transport, salinity anomalies, and Pacific mackerel, Scomber japonicus, abundance. None contributed significantly to the multiple regression with anchovy abundance. Thus, no evidence existed for either Lasker's stable ocean hypothesis of larval mortality or Hjort's larval transport hypothesis. The logarithm of the ratio of sardine recruits at age 2 to the spawning biomass was used as an index of recruitment success. Sardine recruitment success at age 2 was not correlated with larval mortality rates. Sardine recruitment, however, was negatively correlated with both northern anchovy biomass and the combined biomass of Pacific sardine, Pacific mackerel, and northern anchovy. A plausible explanation for this result is that predation by pelagic fishes results in greater mortality rates of sardine larvae and juveniles which in turn decrease sardine recruitment. RP BUTLER, JL (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92037, USA. NR 72 TC 40 Z9 40 U1 0 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1991 VL 48 IS 9 BP 1713 EP 1723 DI 10.1139/f91-203 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GH594 UT WOS:A1991GH59400014 ER PT J AU GHARRETT, AJ SMOKER, WW AF GHARRETT, AJ SMOKER, WW TI 2 GENERATIONS OF HYBRIDS BETWEEN EVEN-YEAR AND ODD-YEAR PINK SALMON (ONCORHYNCHUS-GORBUSCHA) - A TEST FOR OUTBREEDING DEPRESSION SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID POPULATIONS; SURVIVAL AB Hybrids of genetically isolated odd- and even-year pink salmon (Oncorhynchus gorbuscha) from the same stream were made by fertilizing eggs with cryopreserved milt. Anadromous first-generation (F1) hybrids and controls returned to the hatchery at equal rates (153 of 5483 and 160 of 5492, respectively), on the same average date, and with the same size. However, variances of F1 size (female length and weight and male length) exceeded variances of control sizes, suggesting increased genetic variation in F1's. Only 11 of 5165 F2's returned. F2's were similar meristically and in size to fish of their parents' generation, but were bilaterally more asymmetric in number of gill rakers and in combined numbers of gill rakers and of branchiostegals. Increased F1 variation followed by low F2 returns and increased bilateral asymmetry is a pattern to be expected when coadapted allele complexes are disrupted by outbreeding depression. C1 US NATL MARINE FISHERIES SERV,ALASKA FISHERIES CTR,AUKE BAY LAB,AUKE BAY,AK 99821. RP GHARRETT, AJ (reprint author), UNIV ALASKA,SCH FISHERIES & OCEAN SCI,JUNEAU CTR FISHERIES & OCEAN SCI,11120 GLACIER HIGHWAY,JUNEAU,AK 99801, USA. NR 41 TC 62 Z9 65 U1 0 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1991 VL 48 IS 9 BP 1744 EP 1749 DI 10.1139/f91-206 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GH594 UT WOS:A1991GH59400017 ER PT J AU SCHIEWE, MH WEBER, DD MYERS, MS JACQUES, FJ REICHERT, WL KRONE, CA MALINS, DC MCCAIN, BB CHAN, SL VARANASI, U AF SCHIEWE, MH WEBER, DD MYERS, MS JACQUES, FJ REICHERT, WL KRONE, CA MALINS, DC MCCAIN, BB CHAN, SL VARANASI, U TI INDUCTION OF FOCI OF CELLULAR ALTERATION AND OTHER HEPATIC-LESIONS IN ENGLISH SOLE (PAROPHRYS-VETULUS) EXPOSED TO AN EXTRACT OF AN URBAN MARINE SEDIMENT SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID TROUT SALMO-GAIRDNERI; DNA ADDUCT FORMATION; RAINBOW-TROUT; PUGET-SOUND; TOXIC-CHEMICALS; CONTAMINATED SEDIMENT; AROMATIC-COMPOUNDS; POLLUTED HARBOR; AQUARIUM FISH; RIVER ESTUARY AB Epizootiological analyses of field data on prevalances of hepatic neoplasms and other hepatic lesions in English sole (Parophrys vetulus) from Puget Sound suggest a link between these lesions and sediment-associated xenobiotics, particularly aromatic hydrocarbons (AHs). To further investigate this relationship, English sole from a minimally contaminated site were parenterally exposed at monthly intervals for 1 yr to an organic solvent extract of a contaminated urban sediment containing high levels of AHs (30 or 75 mg/kg body weight) or to the model carcinogen benzo[a]pyrene (BaP, 12 mg/kg body weight). Control groups included English sole exposed to an extract of a relatively uncontaminated reference sediment, sole exposed to the carrier only, and untreated sole. Eighteen months after the initial injections, examination of livers revealed a significantly different (increased, p less-than-or-equal-to 0.05) incidence of a spectrum of hepatic lesions, including presumptive preneoplastic foci of cellular alteration, in sole exposed to the urban sediment extract or BaP. Sole in control groups did not develop any of these hepatic lesions. These results represent the first direct demonstration of the hepatotoxicity of sediment-associated chemical contaminants in English sole and strengthen the case for a cause-and-effect relationship between exposure to AHs and epizootic neoplastic hepatic lesions in this species. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112. NR 46 TC 68 Z9 69 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1991 VL 48 IS 9 BP 1750 EP 1760 DI 10.1139/f91-207 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GH594 UT WOS:A1991GH59400018 ER PT J AU Deprit, A AF Deprit, Andre TI THE LISSAJOUS TRANSFORMATION SO CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY LA English DT Article DE Dynamics; Hamiltonian systems; perturbations; reduction; isotropic oscillators AB A new canonical transformation is proposed to handle elliptic oscillators, that is, Hamiltonian systems made of two harmonic oscillators in a 1-1 resonance. Lissajous elements pertain to the ellipse drawn with a light pen whose coordinates oscillate at the same frequency, hence their name. They consist of two pairs of angle-action variables of which the actions and one angle refer to basic integrals admitted by an elliptic oscillator, namely, its energy, its angular momentum and its Runge-Lenz vector. The Lissajous transformation is defined in two ways: explicitly in terms of Cartesian variables, and implicitly by resolution of a partial differential equation separable in polar variables. Relations between the Lissajous variables, the common harmonic variables, and other sets of variables are discussed in detail. C1 NIST, Gaithersburg, MD 20899 USA. RP Deprit, A (reprint author), NIST, Gaithersburg, MD 20899 USA. FU Computational and Applied Mathematics Program at the Defense Advanced Research Program Agency (Washington, DC); Ministerio de Educacion y Ciencia of Spain FX Partial support for the conduct of this research came from the Computational and Applied Mathematics Program at the Defense Advanced Research Program Agency (Washington, DC), and also from the Ministerio de Educacion y Ciencia of Spain. NR 17 TC 34 Z9 34 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-2958 J9 CELEST MECH DYN ASTR JI Celest. Mech. Dyn. Astron. PD SEP PY 1991 VL 51 IS 3 BP 201 EP 225 DI 10.1007/BF00051691 PG 25 WC Astronomy & Astrophysics; Mathematics, Interdisciplinary Applications SC Astronomy & Astrophysics; Mathematics GA V05HA UT WOS:000207115900001 ER PT J AU Deprit, A Elipe, A AF Deprit, Andre Elipe, Antonio TI THE LISSAJOUS TRANSFORMATION SO CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY LA English DT Article DE Dynamics; Hamiltonian systems; perturbations; reduction; isotropic oscillators AB Normalization of a perturbed elliptic oscillator, when executed in Lissajous variables, amounts to averaging over the elliptic anomaly. The reduced Lissajous variables constitute a system of cylindrical coordinates over the orbital spheres of constant energy, but the pole-like singularities are removed by reverting to the subjacent Hopf coordinates. The two-parameter coupling that is a polynomial of degree four admitting the symmetries of the square is studied in detail. It is shown that the normalized elliptic oscillator in that case behaves everywhere in the parameter plane like a rigid body in free rotation about a fixed point, and that it passes through butterfly bifurcations wherever its phase flow admits non isolated equilibria. C1 [Deprit, Andre; Elipe, Antonio] NIST, Gaithersburg, MD 20899 USA. [Elipe, Antonio] Univ Zaragoza, Grp Mecan Espacial, E-50009 Zaragoza, Spain. RP Deprit, A (reprint author), NIST, Gaithersburg, MD 20899 USA. RI Elipe, Antonio/B-8341-2008 OI Elipe, Antonio/0000-0001-5208-4494 NR 26 TC 41 Z9 41 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-2958 J9 CELEST MECH DYN ASTR JI Celest. Mech. Dyn. Astron. PD SEP PY 1991 VL 51 IS 3 BP 227 EP 250 DI 10.1007/BF00051692 PG 24 WC Astronomy & Astrophysics; Mathematics, Interdisciplinary Applications SC Astronomy & Astrophysics; Mathematics GA V05HA UT WOS:000207115900002 ER PT J AU Miller, BR AF Miller, Bruce R. TI THE LISSAJOUS TRANSFORMATION III. PARAMETRIC BIFURCATIONS SO CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY LA English DT Article DE Bifurcations; elliptic oscillator; integrability; Lissajous transformation; normalization; symmetry AB We examine a parametric family of cubic perturbed 1-1 resonant harmonic oscillators with an aim to understanding the phase flows of the reduced system. Variation of the parameters leads the system through five bifurcations of different types. Some bifurcations are due to passage through cases of discrete symmetry or integrability. A conjecture correlating degenerate equilibria in reduced systems with integrability is modified and reinforced. C1 NIST, Gaithersburg, MD 20899 USA. RP Miller, BR (reprint author), NIST, Gaithersburg, MD 20899 USA. EM miller@cam.nist.gov FU Computational and Applied Mathematics Program at the Defense Advanced Research Program Agency (Washington, D. C.) FX Partial support for this research came from the Computational and Applied Mathematics Program at the Defense Advanced Research Program Agency (Washington, D. C.). The author would particularly like to thank Dr. Andre Deprit for many valuable suggestions during the course of this research and for his thorough reading of the drafts of this manuscript. NR 17 TC 23 Z9 23 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-2958 J9 CELEST MECH DYN ASTR JI Celest. Mech. Dyn. Astron. PD SEP PY 1991 VL 51 IS 3 BP 251 EP 270 DI 10.1007/BF00051693 PG 20 WC Astronomy & Astrophysics; Mathematics, Interdisciplinary Applications SC Astronomy & Astrophysics; Mathematics GA V05HA UT WOS:000207115900003 ER PT J AU Deprit, A Williams, CA AF Deprit, Andre Williams, Carol A. TI THE LISSAJOUS TRANSFORMATION IV. DELAUNAY AND LISSAJOUS VARIABLES SO CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY LA English DT Article DE Dynamics; Hamiltonian systems; canonical transformations; isotropic oscillators; Keplerian systems AB Relations are established between the Delaunay variables defined over a phase space E in four dimensions and the Lissajous variables defined over a four-dimensional phase space F when the latter is mapped onto E by a parabolic canonical transformation. C1 [Deprit, Andre] NIST, Gaithersburg, MD 20899 USA. [Williams, Carol A.] Univ S Florida, Dept Math, Tampa, FL 33620 USA. RP Deprit, A (reprint author), NIST, Gaithersburg, MD 20899 USA. FU Computational and Applied Mathematics Program at the Defense Advanced Research Project Agency; Nautical Almanac Office at the U. S. Naval Observatory; Ministerio de Educacion y Ciencia of Spain FX Research for this paper was sponsored in part by the Computational and Applied Mathematics Program at the Defense Advanced Research Project Agency, the Nautical Almanac Office at the U. S. Naval Observatory, and the Ministerio de Educacion y Ciencia of Spain. NR 5 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-2958 J9 CELEST MECH DYN ASTR JI Celest. Mech. Dyn. Astron. PD SEP PY 1991 VL 51 IS 3 BP 271 EP 280 DI 10.1007/BF00051694 PG 10 WC Astronomy & Astrophysics; Mathematics, Interdisciplinary Applications SC Astronomy & Astrophysics; Mathematics GA V05HA UT WOS:000207115900004 ER PT J AU WINK, DA NIMS, RW DESROSIERS, MF FORD, PC KEEFER, LK AF WINK, DA NIMS, RW DESROSIERS, MF FORD, PC KEEFER, LK TI A KINETIC INVESTIGATION OF INTERMEDIATES FORMED DURING THE FENTON REAGENT MEDIATED DEGRADATION OF N-NITROSODIMETHYLAMINE - EVIDENCE FOR AN OXIDATIVE PATHWAY NOT INVOLVING HYDROXYL RADICAL SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Note ID HYDROGEN-PEROXIDE; LIPID-PEROXIDATION; RAT-LIVER; DENITROSATION; IRON(II); ADDUCTS C1 NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899. UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. RP WINK, DA (reprint author), NCI,FREDERICK CANC RES & DEV CTR,CHEM SECT,COMPARAT CARCINOGENESIS LAB,FREDERICK,MD 21702, USA. RI Ford, Peter/D-1826-2011; Keefer, Larry/N-3247-2014 OI Ford, Peter/0000-0002-5509-9912; Keefer, Larry/0000-0001-7489-9555 NR 23 TC 39 Z9 40 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP-OCT PY 1991 VL 4 IS 5 BP 510 EP 512 DI 10.1021/tx00023a002 PG 3 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA GG363 UT WOS:A1991GG36300002 PM 1665352 ER PT J AU COPLEY, JRD AF COPLEY, JRD TI MONTE-CARLO CALCULATION OF MULTIPLE-SCATTERING EFFECTS IN THERMAL-NEUTRON SCATTERING EXPERIMENTS - MODIFICATION TO SPHERICAL GEOMETRY SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article AB The Monte Carlo program "MSCAT85" is used to calculate multiple scattering effects in thermal neutron scattering experiments. The standard sample geometry for this program is one or more cylinders normal to the scattering plane. We describe a subroutine which enables the user to perform calculations on spherically shaped samples. RP COPLEY, JRD (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP-OCT PY 1991 VL 66 IS 2-3 BP 403 EP 406 DI 10.1016/0010-4655(91)90086-Z PG 4 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA GH799 UT WOS:A1991GH79900025 ER PT J AU SIEWERT, TA MCCOWAN, CN AF SIEWERT, TA MCCOWAN, CN TI DEVELOPMENT OF AN SMA ELECTRODE TO MATCH TYPE 316LN BASE-METAL CRYOGENIC PROPERTIES SO CRYOGENICS LA English DT Article DE ELECTRODES; WELDS; ALLOYS ID STAINLESS-STEEL WELDS; TOUGHNESS AB A series of shielded metal arc electrodes was fabricated and the mechanical properties of the resultant welds were measured. The compositions are based on a high Mn, high N version of a type 308 electrode, to which additional Mn, N, Ni and Mo were added. The strength was measured at 4, 76 and 298 K, and the Charpy V-notch absorbed energy was measured at 76 K. The strength of the welds matched or exceeded that strength of the base metal, but fell short of the Charpy V-notch absorbed energy. RP SIEWERT, TA (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 7 TC 0 Z9 0 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD SEP PY 1991 VL 31 IS 9 BP 775 EP 779 DI 10.1016/0011-2275(91)90133-H PG 5 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA GC482 UT WOS:A1991GC48200001 ER PT J AU DANEY, DE AF DANEY, DE TI REGENERATOR PERFORMANCE WITH SINUSOIDAL FLOW SO CRYOGENICS LA English DT Note DE HEAT EXCHANGERS; REGENERATORS; SINUSOIDAL FLOW; THERMAL EFFECTIVENESS AB The ineffectiveness of regenerators with sinusoidal laminar flow through parallel plate, screen and packed sphere matrices is evaluated in the limit of infinite matrix heat capacity. Increases in ineffectiveness of up to 23% over the constant flow values result for parallel plate regenerators. RP DANEY, DE (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD SEP PY 1991 VL 31 IS 9 BP 839 EP 841 DI 10.1016/0011-2275(91)90144-L PG 3 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA GC482 UT WOS:A1991GC48200012 ER PT J AU SQUIRES, D TABOR, S AF SQUIRES, D TABOR, S TI TECHNICAL EFFICIENCY AND FUTURE PRODUCTION GAINS IN INDONESIAN AGRICULTURE SO DEVELOPING ECONOMIES LA English DT Article C1 NATL MARINE FISHERIES SERV,LA JOLLA,CA. UNIV CALIF SAN DIEGO,DEPT ECON,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,GRAD SCH INT RELAT & PACIFIC STUDIES,LA JOLLA,CA 92093. WORLD BANK,WASHINGTON,DC 20433. DEPT AGR,JAKARTA,INDONESIA. NR 25 TC 20 Z9 20 U1 0 U2 1 PU MARUZEN CO LTD PI TOKYO PA PO BOX 5050, TOKYO 100 31, JAPAN SN 0012-1533 J9 DEV ECON JI Dev. Econ. PD SEP PY 1991 VL 29 IS 3 BP 258 EP 270 DI 10.1111/j.1746-1049.1991.tb00211.x PG 13 WC Economics; Planning & Development SC Business & Economics; Public Administration GA HK488 UT WOS:A1991HK48800005 ER PT J AU NELSEN, TA FORDE, EB AF NELSEN, TA FORDE, EB TI THE STRUCTURE, MASS AND INTERACTIONS OF THE HYDROTHERMAL PLUMES AT 26-DEGREES-N ON THE MID-ATLANTIC RIDGE SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID SUSPENDED PARTICLES; NORTHEAST PACIFIC; RIFT-VALLEY; MANGANESE; OCEAN; CHEMISTRY; DEPOSITS; VENTS AB Water-column surveys by combined nephelometer/CTD (NCTD) tows contributed to the 1985 discovery of the first black smokers on the Mid-Atlantic Ridge. Subsequent regional water-column mapping has helped define the extent, mass and interactions of the suspended particulate matter phase (SPM) of the hydrothermal plumes emanating from the known and other nearby sources. The results of 29 NCTD cast/tows, covering 25-30 km2 of ridge segment, indicate the presence of as many as two additional sources based on SPM concentration gradients and plume-top doming over source areas. Plume doming, documented here for the first time from field observations, conforms strikingly with laboratory experiments and can serve as a marker for source field location. A comparison of the plumes' SPM with potential temperature and salinity distributions indicates close correlation in water-column anomaly patterns for each, confirming modification of the regional potential temperature and salinity structure by hydrothermal plumes, which is expressed by wide separation and sloping of isotherms and isohalines. RP NELSEN, TA (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,OCD,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 20 TC 13 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP PY 1991 VL 106 IS 1-4 BP 1 EP 16 DI 10.1016/0012-821X(91)90059-Q PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GM343 UT WOS:A1991GM34300001 ER PT J AU WOLFE, DA MONAHAN, R STACEY, PE FARROW, DRG AF WOLFE, DA MONAHAN, R STACEY, PE FARROW, DRG TI ENVIRONMENTAL-QUALITY OF LONG-ISLAND SOUND - ASSESSMENT AND MANAGEMENT ISSUES SO ESTUARIES LA English DT Article ID TRACE-METALS; RIVER AB Estimated pollutant loadings to Long Island Sound (LIS) are presented and discussed in the context of current information on population trends and land-use characteristics within the drainage basin of the sound. For the conventional pollutants (BOD, N, and P) and for most of the metals examined, the fluxes to LIS from wastewater treatment plants approach or exceed the fluxes from riverine sources. Urban runoff is a significant source for only a few contaminants, such as lead and petroleum hydrocarbons. Atmospheric flux estimates made for other areas are extrapolated to LIS, and this source appears to be significant for lead, zinc, polynuclear aromatic hydrocarbons, and chlorinated pesticides. Continued population growth is projected through 2010, both in the urban centers of the western sound and in the coastal counties surrounding the central and eastern portions of LIS. This growth will place increased pollution pressure on the sound and increased demands on already scarce coastal and estuarine land-use categories. Close interaction between environmental planners, managers, and scientists is required to identify effective control strategies for reducing existing pollutant stress to the sound and for minimizing the effects of future development. C1 US EPA,BOSTON,MA 02203. CONNECTICUT DEPT ENVIRONM PROTECT,HARTFORD,CT 06106. RP WOLFE, DA (reprint author), NOAA,DIV OCEAN ASSESSMENTS,ROCKVILLE,MD 20852, USA. NR 41 TC 25 Z9 25 U1 0 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 224 EP 236 DI 10.2307/1351658 PG 13 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100002 ER PT J AU PARKER, CA OREILLY, JE AF PARKER, CA OREILLY, JE TI OXYGEN DEPLETION IN LONG-ISLAND SOUND - A HISTORICAL-PERSPECTIVE SO ESTUARIES LA English DT Article AB A retrospective analysis of available data was conducted to characterize the spatial distribution and temporal trends in dissolved oxygen (DO) concentrations in Long Island Sound (LIS) over the past four decades. A general east-to-west gradient of decreasing bottom DO was evident in all historical data examined. In our review of data from the 1950s, collected by Gordon Riley and colleagues, and from contemporary surveys, we found no evidence of hypoxia (DO less-than-or-equal-to 3.0 mg l-1) in the Eastern Basin; however, in the deeper waters of the Central Basin, there is some evidence for a recent (1986) emergence of moderate hypoxia. The Western Basin experienced episodes of hypoxia during the 1970s which became more recurrent and possibly more severe in the late 1980s. The most severe, persistent and chronically recurrent hypoxia occurred throughout the water column of the East River and in bottom waters of the Western Narrows. An unprecedented episode of anoxia was observed in both the Western and Eastern Narrows regions of LIS in 1987. Previously, anoxia occurred rarely, was short-lived, and was confined to the East River. Statistical trend analyses revealed a significant increase in the summer minimum bottom DO in the lower and middle reaches of the East River over the past 20 years. Beginning in 1981, however, DO declined markedly in the adjacent Narrows bordering the Nassau County nearshore. The improvements in East River water quality over the previous 15-20 years appears to have been gained at the expense of poorer water quality in the western sound. Mechanisms potentially responsible for the recent decline in bottom DO in western LIS are suggested. C1 NOAA,NATL MARINE FISHERIES SERV,NARRAGANSETT,RI 02882. RP PARKER, CA (reprint author), NOAA,DIV OCEAN ASSESSMENTS,ROCKVILLE,MD 20852, USA. NR 43 TC 85 Z9 86 U1 2 U2 9 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 248 EP 264 DI 10.2307/1351660 PG 17 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100004 ER PT J AU TURGEON, DD OCONNOR, TP AF TURGEON, DD OCONNOR, TP TI LONG-ISLAND SOUND - DISTRIBUTIONS, TRENDS, AND EFFECTS OF CHEMICAL CONTAMINATION SO ESTUARIES LA English DT Article ID MUSSEL-WATCH; TRACE-METALS; OYSTERS; SEDIMENTS; PROGRAM; LEAD AB Trace metals and organic contaminants concentrations are monitored annually in surface sediments, blue mussel tissue, and winter flounder livers at multiple sites in Long Island Sound by National Oceanic and Atmospheric Administration's National Status and Trends (NS&T) program for Marine Environmental Quality. The NS&T program is also conducting various studies on the bioeffects of contaminants in the sound. Three years of monitoring results indicate organic and elemental contaminants concentrations in sediments and biota at sites in the western portion of the sound are high on a national scale. Possible decreasing trends in cadmium and chlordane in the sound are suggested by the 1986-1988 data for their concentrations in mussels. A comparison between NS&T Mussel Watch results and those of the Environmental Protection Agency's Mussel Watch, conducted from 1976 through 1978, indicated a decadal increase in copper concentrations and a decrease in lead in the sound. Bioeffects studies in the sound have revealed responses to contamination only in localized zones where contaminant levels are very high. RP TURGEON, DD (reprint author), NOAA,NATL OCEAN SERV,OFF OCEANOG & MARINE ASSESSMENT,DIV OCEAN ASSESSMENTS,NOAA N OMA32,ROCKVILLE,MD 20852, USA. NR 25 TC 22 Z9 22 U1 0 U2 1 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 279 EP 289 DI 10.2307/1351662 PG 11 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100006 ER PT J AU ROBERTSON, A GOTTHOLM, BW TURGEON, DD WOLFE, DA AF ROBERTSON, A GOTTHOLM, BW TURGEON, DD WOLFE, DA TI A COMPARATIVE-STUDY OF CONTAMINANT LEVELS IN LONG-ISLAND SOUND SO ESTUARIES LA English DT Article AB This paper uses results from the National Oceanic and Atmospheric Administration's National Status and Trends Program (NS&T) to place the environmental quality of Long Island Sound in a broader perspective. It compares levels of contaminants in blue mussels from ten Long Island Sound sites and in sediments from seven Long Island Sound sites with concentrations in the same media at 87 and 221 other sites, respectively, where comparable samples were obtained. In sediments, the levels of both trace metals and organic contaminants tend to be relatively high for Long Island Sound sites. This is especially true for five of the twelve metals (silver, cadmium, copper, lead, and zinc) and for five of six categories of organic contaminants (total chlordane, low molecular weight polycyclic aromatic hydrocarbons (PAHs), high molecular weight PAHs, total polychlorinated biphenyls, and total dichlorodiphenyltrichloroethanes). In mussels, the organic contaminant categories exhibit relatively high levels, but this is not true for most of the metals. In fact, four of the metals-arsenic, mercury, selenium, and zinc-show evidence of relatively low levels in mussels from Long Island Sound compared to other NS&T locations. RP ROBERTSON, A (reprint author), NOAA,NATL OCEAN SERV,ROOM 323,WSC-1,6001 EXECUT BLVD,ROCKVILLE,MD 20852, USA. NR 12 TC 16 Z9 16 U1 0 U2 0 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 290 EP 298 DI 10.2307/1351663 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100007 ER PT J AU GRONLUND, WD CHAN, SL MCCAIN, BB CLARK, RC MYERS, MS STEIN, JE BROWN, DW LANDAHL, JT KRAHN, MM VARANASI, U AF GRONLUND, WD CHAN, SL MCCAIN, BB CLARK, RC MYERS, MS STEIN, JE BROWN, DW LANDAHL, JT KRAHN, MM VARANASI, U TI MULTIDISCIPLINARY ASSESSMENT OF POLLUTION AT 3 SITES IN LONG-ISLAND SOUND SO ESTUARIES LA English DT Article ID SOLE PAROPHRYS-VETULUS; AROMATIC-HYDROCARBONS; PUGET-SOUND; PSEUDOPLEURONECTES-AMERICANUS; HEALTH MONITORS; WINTER FLOUNDER; SEDIMENTS; WASHINGTON; LESIONS; ADDUCTS AB Winter flounder (Pseudopleuronectes americanus) were sampled from three sites located near Norwalk, New Haven, and Niantic, Connecticut, in Long Island Sound during February 1987, to evaluate the degree of chemical contamination and to determine possible effects of contaminant exposure. At each site, sediment and infaunal invertebrates were also collected and analyzed for trace metals and organic chemicals. Specimens of liver and kidney from winter flounder were examined for histopathological conditions, including the presence of macrophage aggregates in liver tissue. Liver samples were also analyzed for DNA damage (i.e., the formation of adducts between DNA and chemical contaminants). Blood samples were collected and analyzed for erythrocyte micronuclei. The sampling site near New Haven was determined to be the most affected site, from the standpoints of greater chemical contamination and possible effects on winter flounder. Concentrations of aromatic hydrocarbons (AHs) and polychlorinated biphenyls (PCBs) were highest in sediment from this site, and the highest prevalences of the histopathological changes and DNA alterations were also found in the livers of winter flounder from this site. No differences in the concentrations of contaminants in fish or in frequencies of erythrocyte micronuclei in fish blood were found between sites. None of the sites sampled had contaminant levels or prevalences of lesions as high as previously found at other East Coast locations (e.g., Boston Harbor, Massachusetts, Raritan Bay, New York). Overall, our results indicate moderate levels of pollution at two of the urban sites in Long Island Sound and provide a framework for expanded studies to better define the extent and impact of chemical pollution in Long Island Sound. RP GRONLUND, WD (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 29 TC 30 Z9 30 U1 0 U2 1 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 299 EP 305 DI 10.2307/1351664 PG 7 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100008 ER PT J AU PERRY, DM HUGHES, JB HEBERT, AT AF PERRY, DM HUGHES, JB HEBERT, AT TI SUBLETHAL ABNORMALITIES IN EMBRYOS OF WINTER FLOUNDER, PSEUDOPLEURONECTES-AMERICANUS, FROM LONG-ISLAND SOUND SO ESTUARIES LA English DT Article ID PCB CONCENTRATIONS; ETHYL METHANESULFONATE; INDUCTION; FISH; BENZOPYRENE; ABERRATIONS; MICRONUCLEI; WATER; EGGS AB Sublethal abnormalities were examined in developing embroys of the winter flounder, Pseudopleuronectes americanus, as part of a study of its early reproductive success in Long Island Sound and two sites in Boston Harbor. These sites represented varying levels of anthropogenic contamination that were possibly affecting reproduction, as ascertained by chromosomal abnormalities and lowered developmental rates in the embryos. Effort was focused on examination of blastula and tail-bud embryos from field-captured females spawned at the laboratory. Abnormalities observed included evidence of cytotoxicity and chromosome damage. Embryos of fish from New Haven were usually the most aberrant, while embryos from other sites, notably Hempstead, Shoreham, and both Boston Harbor stations, showed subtle indications of abnormality. RP PERRY, DM (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460, USA. NR 45 TC 12 Z9 12 U1 0 U2 0 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 306 EP 317 DI 10.2307/1351665 PG 12 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100009 ER PT J AU NELSON, DA MILLER, JE RUSANOWSKY, D GREIG, RA SENNEFELDER, GR MERCALDOALLEN, R KUROPAT, C GOULD, E THURBERG, FP CALABRESE, A AF NELSON, DA MILLER, JE RUSANOWSKY, D GREIG, RA SENNEFELDER, GR MERCALDOALLEN, R KUROPAT, C GOULD, E THURBERG, FP CALABRESE, A TI COMPARATIVE REPRODUCTIVE SUCCESS OF WINTER FLOUNDER IN LONG-ISLAND SOUND - A 3-YEAR STUDY (BIOLOGY, BIOCHEMISTRY, AND CHEMISTRY) SO ESTUARIES LA English DT Article ID TROUT SALVELINUS-FONTINALIS; PSEUDOPLEURONECTES-AMERICANUS; PCB CONCENTRATIONS; TEMPERATURE; GROWTH; EGGS AB In a 3-yr study, late prespawing winter flounder were collected from various stations in Long Island Sound (three of them heavily urbanized) and spawned in the laboratory. For comparative purposes, flounder from two sites in the Boston Harbor area were similarly treated in 1987 and 1988. Of the stations in Long Island Sound, New Haven Harbor alone consistently produced low percent viable hatch and small larvae. Boston Harbor produced the smallest larvae of all sites. There were no significant station-to-station differences in lipid utilization during larval development; yolk reserves at stations showing a low percent viable hatch, small larvae, and low embryonic development rate were probably used in part for stress metabolism. No significant differences in concentrations of polychlorinated biphenyls for collections from Long Island Sound were found either in livers of spawned fish, in sediments, or in eggs of winter flounder. The very low metal concentrations in winter flounder eggs showed no relation to the degree of metal contamination found at stations in Long Island Sound and Boston Harbor. RP NELSON, DA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460, USA. NR 52 TC 27 Z9 27 U1 0 U2 0 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 318 EP 331 DI 10.2307/1351666 PG 14 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100010 ER PT J AU STILES, S CHOROMANSKI, J NELSON, D MILLER, J GREIG, R SENNEFELDER, G AF STILES, S CHOROMANSKI, J NELSON, D MILLER, J GREIG, R SENNEFELDER, G TI EARLY REPRODUCTIVE SUCCESS OF THE HARD CLAM (MERCENARIA-MERCENARIA) FROM 5 SITES IN LONG-ISLAND SOUND SO ESTUARIES LA English DT Article ID TRACE-METAL; MYTILUS-EDULIS; MUSSEL; BIVALVES; PCB; BIOASSAYS; SEDIMENTS; EMBRYOS; OYSTERS; LARVAE AB Early reproductive success of hard clams (Mercenaria mercenaria) in Long Island Sound was measured to determine whether pollution may have adverse effects on fragile recruitment to fisheries. Clams were collected at five sites in 1987 when ready to spawn naturally, along with water from within 39 cm of the bottom. Levels of polychlorinated biphenyls (PCBs), copper, and cadmium were measured in the mature gonad and were found to be generally low. Clams were spawned and the gametes were collected and cultured both in their respective site waters and in reference laboratory seawater. In both site and reference seawater, embryos of clams from the most highly industrialized area (Bridgeport) with higher contaminant levels exhibited more irregularity in chromosome numbers and greater larval abnormality, possible indicators of long-term sublethal effects. Fertilization and early meiotic success at 1 to 1 1/2 h were significantly lower (P less-than-or-equal-to 0.05) for clams from Norwalk (55%) than for those from Greenwich (75%). At 48 h, mortality was lowest for Greenwich larvae and highest for Norwalk larvae in their respective site waters, but the mortality for these two sites was significantly lower than for other sites in reference water. This suggests sporadically poor environmental quality. Milford larvae also had significant mortality. Population-level significance of pollution effects on clam reproduction will depend on how contaminated the environment is over the entire reproductive season of the clams in Long Island Sound, and over how large a portion of the spawning grounds. RP STILES, S (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460, USA. NR 54 TC 13 Z9 13 U1 1 U2 6 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1991 VL 14 IS 3 BP 332 EP 342 DI 10.2307/1351667 PG 11 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA GH341 UT WOS:A1991GH34100011 ER PT J AU MURAWSKI, SA AF MURAWSKI, SA TI CAN WE MANAGE OUR MULTISPECIES FISHERIES SO FISHERIES LA English DT Article AB Fishery resources (fish, invertebrates, marine mammals, and reptiles) of the U.S. exclusive economic zone (EEZ, 3-200 nautical miles from the coast) are currently regulated under several pieces of key legislation enacted during the early 1970s. At that time fishery science was only beginning to appreciate the interactions among species and fisheries as being potential impediments to simultaneous realization of competitive management goals. Many of the important management problems currently faced in the EEZ are exacerbated by the incompatibility of regulations promulgated separately under these statues, for what are ecologically- or technologically-related species. Reconciling the management of interacting species and fishermen will require an institutional framework for evaluating the multispecies/multifishery consequences of management decisions, and for articulating a clear set of compatible management goals for the various constituents. Traditional single-species biological reference points for fishery management must be reevaluated considering the effects of harvesting on ecosystem attributes such as stability, diversity, resistance, and resilience, and economic attributes including optimization. Currently, dynamic mechanisms underlying species and fishery interactions are poorly understood. The scientific basis of decision making will increasingly have to come from research emphasizing the dynamic relationships of interacting species as well as the biological, economic, and technological factors contributing to fishery interactions. Such studies cannot replace traditional single-species, single-fishery analyses, but must compliment and build upon them. RP MURAWSKI, SA (reprint author), NATL MARINE FISHERIES SERV,NE FISHERIES CTR,POPULAT DYNAM BRANCH,WOODS HOLE,MA 02543, USA. NR 0 TC 33 Z9 34 U1 1 U2 5 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD SEP-OCT PY 1991 VL 16 IS 5 BP 5 EP 13 DI 10.1577/1548-8446(1991)016<0005:CWMOMF>2.0.CO;2 PG 9 WC Fisheries SC Fisheries GA GM939 UT WOS:A1991GM93900003 ER PT J AU EKLUND, AM TARGETT, TE AF EKLUND, AM TARGETT, TE TI SEASONALITY OF FISH CATCH RATES AND SPECIES COMPOSITION FROM THE HARD BOTTOM TRAP FISHERY IN THE MIDDLE ATLANTIC BIGHT (UNITED-STATES EAST-COAST) SO FISHERIES RESEARCH LA English DT Article AB Fish community composition on natural hard bottom reef areas off the cots of Maryland and northern Virginia was investigated by examining the species composition and seasonality of catch of the most frequently caught species from the black sea bass (Centropristis striata) trap fishery. Hard bottom areas were sampled with wooden fish traps from April to early December 1987. Mean catch per trap and total length were determined for the most commonly caught species. Black sea bass comprised over 96% of the catch overall. The other abundant species were: spotted hake (Urophycis regia), tautog (Tautoga onitis), red hake (Urophycis chuss), conger eel (Conger oceanicus), scup (Stenotomus chrysops), and ocean pout (Macrozoarces americanus). The catches of each species fluctuated through time, apparently as a result of seasonal migration patterns. Most species appeared to migrate inshore in the spring and offshore in the autumn. Ocean pout had not previously been reported to occur south of Delaware and was most abundant during the time of the coldest temperatures. The fish community on hard bottom areas in the Middle Atlantic Bight (MAB) had not been adequately described previously owing to the limitation of trawl nets sampling rough bottom. The hard bottom reef fish community differs considerably from that reported from South Atlantic Bight reef areas as well as from smooth bottom areas on the MAB continental shelf. The present study also provides data to compare with future studies on fish communities inhabiting artificial reefs. RP EKLUND, AM (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES CTR,MIAMI LAB,75 VIRGINIA BEACH DR,MIAMI,FL 33149, USA. NR 0 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD SEP PY 1991 VL 12 IS 1 BP 1 EP 22 DI 10.1016/0165-7836(91)90045-H PG 22 WC Fisheries SC Fisheries GA GE926 UT WOS:A1991GE92600001 ER PT J AU POLACHECK, T AF POLACHECK, T TI MEASURES OF EFFORT IN TUNA LONGLINE FISHERIES - CHANGES AT THE OPERATIONAL LEVEL SO FISHERIES RESEARCH LA English DT Article AB Changes at the operational level of a fishery can affect the efficiency of gear and need to be taken into account when catch per unit effort indices are used to assess the status of fish stocks. Catch per unit of effort indices form the basis for the assessment of most tuna longline fisheries. Effort in these fisheries is measured in terms of the total number of hooks set and differences at the operational level in the number of hooks per longline set are generally not considered. It is shown that the number of hooks per set in the Pacific Japanese longline fishery has increased steadily from 1962 to 1986 by about 40%. The increase does not appear to be related to vessel size. Changes in the number of hooks per set can potentially affect the average efficiency of individual hooks. Analyses of catch rates (number per hook), based on data from 1979 to 1986 and categorized according to the number of hooks per set, suggest no consistent trend, although the category with the largest number of hooks per set tended to have higher catch rates for yellowfin and slightly lower rates for bigeye. These results suggest that the number of hooks per set does not interact with the efficiency or catchability of an individual hook. Comparison of catch rates, based on the number of hooks and the number of sets, suggests that the choice of an effort measure can substantially affect either observed trends in catch rates over time or the relative changes in their magnitude. In recent years, decreases in the catch per hook have been offset at the set level by increases in the number of hooks per set. Overall, the results suggest that the number of hooks should continue to be used as the best measure of effort for stock assessment purposes, but is not appropriate for economic analyses. RP POLACHECK, T (reprint author), NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE,MA 02543, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD SEP PY 1991 VL 12 IS 1 BP 75 EP 87 DI 10.1016/0165-7836(91)90051-G PG 13 WC Fisheries SC Fisheries GA GE926 UT WOS:A1991GE92600007 ER PT J AU VANPOOLEN, LJ NIESEN, VG RAINWATER, JC AF VANPOOLEN, LJ NIESEN, VG RAINWATER, JC TI EXPERIMENTAL-METHOD FOR OBTAINING CRITICAL DENSITIES OF BINARY-MIXTURES - APPLICATION TO ETHANE + N-BUTANE SO FLUID PHASE EQUILIBRIA LA English DT Article ID VAPOR-LIQUID-EQUILIBRIA; CRITICAL LOCUS; NORMAL-BUTANE; PRESSURES; SYSTEMS; (VAPOR; CO2 AB According to the experimental and analytical procedure proposed by Van Poolen and Rainwater, rectilinear diameters based on measured vapor-liquid coexistence densities along a path of constant overall density and composition have been determined and used to obtain critical densities of the binary mixture ethane + n-butane. Seven experimental runs for the mixture were made at compositions ranging from, 21.65 to 80.75 mol% ethane. The procedure has been explored as a new way to determine critical densities of mixtures. Results are compared with densities generated from a modified Leung-Griffiths correlation of the extensive vapor-liquid equilibrium data of Kay. The critical densities obtained are in agreement with the correlation within the overall uncertainty of the method, thereby verifying the proposed technique. C1 CALVIN COLL,DEPT ENGN,GRAND RAPIDS,MI 49546. RP VANPOOLEN, LJ (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 29 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD SEP PY 1991 VL 66 IS 1-2 BP 161 EP 185 DI 10.1016/0378-3812(91)85053-W PG 25 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA GH879 UT WOS:A1991GH87900010 ER PT J AU HANSON, DR RAVISHANKARA, AR AF HANSON, DR RAVISHANKARA, AR TI THE LOSS OF CF2O ON ICE, NAT, AND SULFURIC-ACID-SOLUTIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR STRATOSPHERIC CLOUDS; GROWTH AB We measured the first-order loss rate coefficients for CF2O on solid surfaces, ice and HNO3-treated ice, and on sulfuric acid solutions that coated the inside wall of a flow tube. We determined an upper limit for the uptake coefficient, gamma, of approximately 3x10(-6) for CF2O on ice and HNO3-treated ice. A value for gamma on a 60% (by weight) sulfuric acid solution of 3(+2/-3)x10(-6) was measured and we observed a higher value over 40% acid, gamma = 6x10(-5) (+/- 30%). The loss of CF2O on stratospheric particles is a very slow process and will be insignificant for events that occur on timescales of a year, such as the annual polar chlorine activation phenomena. C1 UNIV COLORADO,INST RES ENVIRONM SCI,BOULDER,CO 80309. RP HANSON, DR (reprint author), NOAA,AERON LAB,R-E-AL2,325 BROADWAY,BOULDER,CO 80303, USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 17 TC 17 Z9 17 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 SEP PY 1991 VL 18 IS 9 BP 1699 EP 1701 DI 10.1029/91GL02093 PG 3 WC Geosciences, Multidisciplinary SC Geology GA GF593 UT WOS:A1991GF59300012 ER PT J AU MEERTENS, CM SMITH, RB AF MEERTENS, CM SMITH, RB TI CRUSTAL DEFORMATION OF THE YELLOWSTONE CALDERA FROM 1ST GPS MEASUREMENTS - 1987-1989 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB A Global Positioning System (GPS) network was established in 1987 in order to measure crustal deformation across the Yellowstone Plateau (centered on the Yellowstone caldera) and adjacent Teton, Wyoming, and Hebgen Lake, Montana, fault zones. Forty-four GPS stations in the Yellowstone network were re-surveyed in 1989 and station coordinates using broadcast orbits were obtained. These results were used to assess the precision and accuracy of the GPS surveys and to identify areas of rapid crustal deformation on the Yellowstone Plateau. The GPS measured displacements between 1987 and 1989 were calculated relative to a station at the eastern edge of the 100 km-wide network. The relative horizontal displacements have an average magnitude of 15 +/- 10 mm. The relative vertical displacements are generally less than 25 mm about an average near zero and with an uncertainty of +/- 20 mm. Comparisons with leveling and trilateration measurements, taken nearly simultaneously, suggest that the accuracy of these GPS measurements is at the level of the above uncertainties. GPS-measured vertical displacements across the northern part of the Yellowstone caldera and 1st-order leveling results show up to 20 mm of subsidence between 1987 and 1989. This subsidence is part of a six year period of caldera deflation that began in 1985. In addition, up to 66 mm of uplift is observed with GPS at the northwest edge of the Yellowstone caldera and may be associated with processes following an intense earthquake swarm in 1985-86 and with caldera subsidence. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,UNAVCO,BOULDER,CO 80309. RP MEERTENS, CM (reprint author), UNIV UTAH,DEPT GEOL & GEOPHYS,SALT LAKE CITY,UT 84112, USA. OI Meertens, Charles/0000-0003-1811-0307 NR 9 TC 14 Z9 14 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 SEP PY 1991 VL 18 IS 9 BP 1763 EP 1766 DI 10.1029/91GL01470 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GF593 UT WOS:A1991GF59300028 ER PT J AU MLYNCZAK, MG SOLOMON, S AF MLYNCZAK, MG SOLOMON, S TI MIDDLE ATMOSPHERE HEATING BY EXOTHERMIC CHEMICAL-REACTIONS, INVOLVING ODD-HYDROGEN SPECIES - REPLY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Note ID DIPOLE-MOMENT FUNCTION; TRANSITION-PROBABILITIES; HYDROXYL; OH C1 NOAA,AERON LAB,BOULDER,CO 80303. RP MLYNCZAK, MG (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 401B,HAMPTON,VA 23665, USA. RI Mlynczak, Martin/K-3396-2012 NR 10 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP PY 1991 VL 18 IS 9 BP 1793 EP 1794 DI 10.1029/91GL02139 PG 2 WC Geosciences, Multidisciplinary SC Geology GA GF593 UT WOS:A1991GF59300036 ER PT J AU SARMA, AD HILL, RJ AF SARMA, AD HILL, RJ TI EFFECT OF BLOWING SNOW AND GROUND BLIZZARDS ON MILLIMETER-WAVE SCINTILLATION SPECTRA SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE MILLIMETER WAVE PROPAGATION; BLOWING SNOW; GROUND BLIZZARDS; MULTIPATH PROPAGATION ID FREQUENCY; PATH AB We describe the effect of ground blizzards and blowing snow on millimeter wave scintillation spectra at 116 and 230 GHz. During snowstorms, multipath propagation can occur for various reasons. Whatever the reason for the multipath, it will affect the scintillation spectrum. Enhancement of the scintillation spectrum is observed at both low and high temporal frequencies. In some cases, two additional corner frequencies are evident at the high-frequency end of the scintillation spectrum. The method of obtaining the cross-path wind component fails when the wind is nearly parallel to the propagation path. RP SARMA, AD (reprint author), NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD SEP PY 1991 VL 12 IS 9 BP 997 EP 1022 DI 10.1007/BF01009554 PG 26 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA GF200 UT WOS:A1991GF20000003 ER PT J AU QIAN, XM WAKID, S VAMAN, D CYPHER, D AF QIAN, XM WAKID, S VAMAN, D CYPHER, D TI ARCHITECTURES FOR BISDN NETWORKS - A PERFORMANCE STUDY SO INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS LA English DT Article DE ASYNCHRONOUS TRANSFER MODE (ATM); BROAD-BAND ISDN (BISDN); INTEGRATED SERVICES DIGITAL NETWORK (ISDN); LOCAL AREA NETWORK (LAN); MAGNITUDE; METROPOLITAN AREA NETWORK (MAN); NETWORKS; TRANSMIT AB We explore the use of the two current architectures for broadband integrated services digital networks (BISDN) as being defined in IEEE P802.6 (local and metropolitan area network) 1 and ANSI-accredited Committee T1's T1S1.5 baseline document. 2 The standard currently defines procedures for the median access control (MAC) layer and interfaces for some upper layer services. We, therefore, use the two services defined by the adaptation layer, namely messaging and streaming, to compare their relative performance. It is shown that many conditions are necessary for streaming to out-perform messaging. We then simulate the performance behaviour of these signalling protocols required for the isochronous services of IEEE P802.6 to determine end-to-end delay. This allows us to extend such predictions to the use of IEEE P802.6 as a backbone for concatenated LANs. C1 NATL INST STAND & TECHNOL,DIV ADV SYST,BLDG 223,ROOM B364,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0737-2884 J9 INT J SATELL COMMUN JI Int. J. Satell. Commun. PD SEP-OCT PY 1991 VL 9 IS 5 BP 313 EP 327 DI 10.1002/sat.4600090509 PG 15 WC Engineering, Aerospace; Telecommunications SC Engineering; Telecommunications GA GN987 UT WOS:A1991GN98700008 ER PT J AU YENER, KA SAYRE, EV JOEL, EC OZBAL, H BARNES, IL BRILL, RH AF YENER, KA SAYRE, EV JOEL, EC OZBAL, H BARNES, IL BRILL, RH TI STABLE LEAD ISOTOPE STUDIES OF CENTRAL TAURUS ORE SOURCES AND RELATED ARTIFACTS FROM EASTERN MEDITERRANEAN CHALCOLITHIC AND BRONZE-AGE SITES SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Article DE LEAD ISOTOPES; METALS; ARTIFACTS; CENTRAL TAURUS; EASTERN MEDITERRANEAN; CHALCOLITHIC; BRONZE AGE ID BOLKARDAG C1 BOGAZICI UNIV,FAC ARTS & SCI,ISTANBUL,TURKEY. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. CORNING MUSEUM GLASS,CORNING,NY 14830. RP YENER, KA (reprint author), SMITHSONIAN INST,CONSERVAT ANALYT LAB,WASHINGTON,DC 20560, USA. NR 108 TC 54 Z9 55 U1 0 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD SEP PY 1991 VL 18 IS 5 BP 541 EP 577 DI 10.1016/0305-4403(91)90053-R PG 37 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA GG018 UT WOS:A1991GG01800003 ER PT J AU POLAK, ML HO, J GERBER, G LINEBERGER, WC AF POLAK, ML HO, J GERBER, G LINEBERGER, WC TI PHOTOELECTRON-SPECTROSCOPY OF NEGATIVELY CHARGED BISMUTH CLUSTERS - BI2-, BI3-, AND BI4- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC STATES; VIBRATIONAL STRUCTURE; DIATOMIC BISMUTH; COPPER CLUSTERS; GAS MATRICES; BI-2; PHOTODETACHMENT; SPECTRA; TRIPLET; ANIONS AB We have recorded the 351 nm photoelectron spectra of Bi2-, Bi3-, and Bi4-. The spectrum of Bi2- shows transitions to at least seven electronic states of Bi2 neutral, four of which are observed with vibrational resolution. Term energies, bond lengths, and vibrational frequencies are obtained for the anion ground state and for the first three excited states of Bi2. These results are compared to previous spectroscopic measurements and to the ab initio calculations presented in the accompanying paper. The photoelectron spectrum of Bi3- reveals some of the electronic structure of Bi3 and the results are discussed in comparison to recent theoretical work. Adiabatic electron affinities are obtained for Bi2 [1.271(8) eV] and for Bi3 [1.60(3) eV]. The electron affinity of Bi4 is estimated from the onset of photodetachment to be 1.05(10) eV. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 53 TC 49 Z9 49 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1991 VL 95 IS 5 BP 3053 EP 3063 DI 10.1063/1.460862 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500004 ER PT J AU TURNIPSEED, AA VAGHJIANI, GL GIERCZAK, T THOMPSON, JE RAVISHANKARA, AR AF TURNIPSEED, AA VAGHJIANI, GL GIERCZAK, T THOMPSON, JE RAVISHANKARA, AR TI THE PHOTOCHEMISTRY OF OZONE AT 193 AND 222 NM SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER FLASH-PHOTOLYSIS; QUANTUM YIELDS; DEACTIVATION; O(D-1); REGION; 248-NM; O-3; O3; FLUORESCENCE; DISSOCIATION AB The quantum yields for the formation of O(1D) and O(3P) from the photolysis of ozone have been measured at 222 and 193 nm. The quantum yield for O(3P) was observed to be PHI-(3P) = 0.13 +/- 0.02 at 222 nm, and the primary quantum yield for O(1D) was found to be PHI-(1D) = 0.87 +/- 0.04. This measurement is consistent with othe studies of O3 photolysis within the Hartley band which indicate that a significant portion (5-15%) of the products are formed in the ground state. At 193 nm the quantum yield for the production of excited state O(1D) atoms is PHI-(1D) = 0.46 +/- 0.29, which is significantly less than what is observed during photolysis within the lower energy Hartley band. The quantum yield for O(3P) atoms at 193 nm was found to be 0.57 +/- 0.14. We have also observed that the quantum yield for O atoms [O(1D) + O(3P)] is greater than unity [PHI-(O) = 1.20 +/- 0.15] at 193 nm indicating the presence of a channel which produces three O(3P) atoms. O2(b 1-SIGMA) has also been detected and quantified, PHI-(b 1-SIGMA) = 0.50 +/- 0.38, from O3 photolysis at 193 nm. These measurements suggest that O(1D) and O2(b 1-SIGMA) are co-produced. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 30 TC 78 Z9 80 U1 1 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 SEP 1 PY 1991 VL 95 IS 5 BP 3244 EP 3251 DI 10.1063/1.460881 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GD055 UT WOS:A1991GD05500025 ER PT J AU EIDELMAN, N BROWN, WE MEYER, JL AF EIDELMAN, N BROWN, WE MEYER, JL TI SELECTIVE-INHIBITION OF CRYSTAL-GROWTH ON OCTACALCIUM PHOSPHATE AND NONSTOICHIOMETRIC HYDROXYAPATITE BY PYROPHOSPHATE AT PHYSIOLOGICAL CONCENTRATION SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID INORGANIC PYROPHOSPHATE; BONE-FORMATION; CALCIUM; SERUM; TRANSFORMATION; CALCIFICATION; SOLUBILITY; CARTILAGE; TISSUES; APATITE AB Octacalcium phosphate, Ca8H2(PO4)6.5H2O (OCP), appears to be a precursor in biomineral formation. The formation of OCP as the precursor is supported by the observation that stoichiometric hydroxyapatite, Ca5(PO4)3OH (OHAp), cannot form directly because of the presence of its growth inhibitors in serum. Therefore, the effects of the physiological concentration of pyrophosphate (P2O74-), one of the most important calcium phosphate growth inhibitors in blood, on calcium phosphate growth rates on OCP and nonstoichiometric OHAp) (apatite) seeds were measured. The amounts of seed crystals used to initiate the growth were adjusted by trial and error so that the control growth rates (in the absence of P2O74-) were the same on both OCP and apatite seeds at a given supersaturation. The crystal growth on both kinds of seed crystals from supersaturated solutions in the presence of 1-mu-M P2O74- added once ("one-time" addition) at constant pH (7.4) and 25-degrees-C was determined by KOH titration and decreases in Ca and PO4 concentrations in the solutions. Crystal growth on OCP seed crystals in the presence of a constant concentration of 1-mu-M P2O74- was also measured. The growing phases were characterized by DELTA-Ca/DELTA-PO4 ratios, chemical potential plots, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The results of this study show that: (1) P2O74- ions inhibited the growth on the apatite seeds more than on the OCP seeds; (2) apparently OCP precipitated on both types of seeds, followed by its hydrolysis to a more apatite-like phase; (3) slower crystal growth was observed on OCP seeds in the presence of a constant physiological concentration of P2O74- (1-mu-M) than in the "one-time" addition of P2O74-. C1 NCI,BETHESDA,MD 20892. RP EIDELMAN, N (reprint author), NATL INST STAND & TECHNOL,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899, USA. NR 36 TC 10 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1991 VL 113 IS 3-4 BP 643 EP 652 DI 10.1016/0022-0248(91)90100-J PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA GM356 UT WOS:A1991GM35600034 ER PT J AU COOK, GR SIMIU, E AF COOK, GR SIMIU, E TI PERIODIC AND CHAOTIC OSCILLATIONS OF MODIFIED STOKER COLUMN SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB Records are presented of typical measured motions of a modified forced Stoker column, including periodic motion around a stable fixed point of the unforced column; periodic snap-through motion around the unstable fixed point; and chaotic motion. Characterizations of the recorded chaotic motion include the autocorrelation function; the spectral density plot; capacity dimensions (d(c) approximately-equal-to 2.3 for attractor in three-dimensional phase space; d(c) approximately-equal-to 1.25 for corresponding Poincare plot); and the Lyapounov exponent (gamma approximately-equal-to 3.0). Numerical simulations were performed in which spring stiffnesses measured under static conditions and dissipative forces based on the viscous damping model were used. The experimental device was represented as a multidegree-of-freedom system that approximated the distributed mass and stiffness of the springs. The simulations yielded chaotic motions comparable qualitatively to, though different quantitatively from, those recorded in the laboratory. As evidenced by the estimated fractal dimension, the influence of the spring mass distribution was not sufficiently strong to affect the dimension of the embedding phase space for the attractor of the chaotic motion. RP COOK, GR (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 19 TC 3 Z9 3 U1 1 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD SEP PY 1991 VL 117 IS 9 BP 2049 EP 2064 DI 10.1061/(ASCE)0733-9399(1991)117:9(2049) PG 16 WC Engineering, Mechanical SC Engineering GA GD121 UT WOS:A1991GD12100007 ER PT J AU SQUIRES, D KIRKLEY, J AF SQUIRES, D KIRKLEY, J TI PRODUCTION QUOTA IN MULTIPRODUCT PACIFIC FISHERIES SO JOURNAL OF ENVIRONMENTAL ECONOMICS AND MANAGEMENT LA English DT Article C1 COLL WILLIAM & MARY, SCH BUSINESS ADM, GLOUCESTER POINT, VA 23062 USA. COLL WILLIAM & MARY, SCH MARINE SCI, GLOUCESTER POINT, VA 23062 USA. RP SQUIRES, D (reprint author), NATL MARINE FISHERIES SERV, SW FISHERIES CTR, POB 271, LA JOLLA, CA 92038 USA. NR 24 TC 60 Z9 60 U1 1 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0095-0696 J9 J ENVIRON ECON MANAG JI J.Environ.Econ.Manage. PD SEP PY 1991 VL 21 IS 2 BP 109 EP 126 DI 10.1016/0095-0696(91)90036-I PG 18 WC Business; Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA GA373 UT WOS:A1991GA37300002 ER PT J AU GRAY, WB JONES, CA AF GRAY, WB JONES, CA TI LONGITUDINAL PATTERNS OF COMPLIANCE WITH OCCUPATIONAL-SAFETY AND HEALTH ADMINISTRATION HEALTH AND SAFETY REGULATIONS IN THE MANUFACTURING SECTOR SO JOURNAL OF HUMAN RESOURCES LA English DT Article ID IMPACT C1 NATL BUR ECON RES,CAMBRIDGE,MA 02138. US DEPT COMMERCE,NOAA,ROCKVILLE,MD. RP GRAY, WB (reprint author), CLARK UNIV,DEPT ECON,WORCESTER,MA 01610, USA. NR 22 TC 23 Z9 24 U1 0 U2 5 PU UNIV WISCONSIN PRESS PI MADISON PA JOURNAL DIVISION, 114 N MURRAY ST, MADISON, WI 53715 SN 0022-166X J9 J HUM RESOUR JI J. Hum. Resour. PD FAL PY 1991 VL 26 IS 4 BP 623 EP 653 DI 10.2307/145978 PG 31 WC Economics; Industrial Relations & Labor SC Business & Economics GA GR271 UT WOS:A1991GR27100003 ER PT J AU COUDERT, LH HOUGEN, JT AF COUDERT, LH HOUGEN, JT TI TUNNELING SPLITTINGS IN (XY3)2-TYPE DIMERS SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID AMMONIA DIMER; WATER DIMER; MICROWAVE-SPECTRUM; COMPLEXES; (HF)2 C1 CNRS,F-75005 PARIS,FRANCE. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP COUDERT, LH (reprint author), UNIV PARIS 06,PHYS MOLEC & ATMOSPHER LAB,TOUR 13-4 PL JUSSIEU,F-75252 PARIS 05,FRANCE. NR 22 TC 15 Z9 15 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1991 VL 149 IS 1 BP 73 EP 98 DI 10.1016/0022-2852(91)90144-Y PG 26 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GB707 UT WOS:A1991GB70700005 ER PT J AU CORKERY, SM BROWN, JM BEATON, SP EVENSON, KM AF CORKERY, SM BROWN, JM BEATON, SP EVENSON, KM TI MOLECULAR-PARAMETERS OF CHROMIUM HYDRIDE IN ITS X6-SIGMA+ STATE DETERMINED BY FAR-INFRARED LASER MAGNETIC-RESONANCE SPECTROSCOPY SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID TRANSITION-METAL HYDRIDES; ROTATIONAL SPECTRUM; CRH; NIH; FEH; ESR; COH C1 PHYS CHEM LAB,OXFORD OX1 3QZ,ENGLAND. NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NR 32 TC 26 Z9 26 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1991 VL 149 IS 1 BP 257 EP 273 DI 10.1016/0022-2852(91)90158-7 PG 17 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GB707 UT WOS:A1991GB70700019 ER PT J AU BRYAN, K AF BRYAN, K TI COX,MICHAEL (1941-1989) - HIS PIONEERING CONTRIBUTIONS TO OCEAN CIRCULATION MODELING SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Review ID RESOLVING NUMERICAL-MODEL; EQUATORIAL PACIFIC-OCEAN; VENTILATED THERMOCLINE; NORTH-ATLANTIC; TRANSPORT; WAVES; WIND; GENERATION; SIMULATION; EDDIES AB Michael Cox was a pioneer in the development and application of numerical models to the study of the ocean circulation. His simulation of the response of the Indian Ocean to the monsoons was one of the first applications of a numerical model to seasonal changes in circulation near the equator. Cox's finding that the seasonal reversal of the Somali Current was primarily due to local monsoon-driven coastal upwelling challenged a popular theory that the effects of remote forcing, propagating westward along the equatorial waveguide, were the most important mechanism. In a detailed follow-up study, he was able to demonstrate that remote forcing could only be important near the equator along the Somali Coast and that local driving was the only viable mechanism to explain the amplitude and phase of the main features of the seasonal reversal of the Somali Current. In another pioneering calculation, Cox was the first to simulate the seasonal changes of the eastern equatorial Pacific, including the Legeckis waves between the South Equatorial Current and the Equatorial Counter Current. From his analysis, he concluded that the Legeckis waves were due to both baroclinic and barotropic instability. Using observed temperature and salinity data, Cox carried out a new type of diagnostic study of the circulation of the World Ocean. His calculations demonstrated the great importance of adjusting the observed density field in a manner compatible with the constraints imposed by the conservation of mass, temperature, and salinity. In a detailed comparison of simulations of ocean circulation in eddy- and noneddy-resolving models of simplified geometry, Cox was able to demonstrate that mesoscale eddies could have some very important effects on midlatitude thermocline ventilation by wind-driven downwelling. In particular, the mixing by mesoscale eddies along isopycnal surfaces could be strong enough to erase tracer and potential vorticity gradients over trajectories of less than 2000 km. On the other hand, Cox found that poleward transport of buoyancy was approximately the same in similar runs, which did, or did not, include mesoscale eddies. He concluded that this was due to eddy-time mean flow compensation. A similar phenomenon exists in the weakly driven flows of the earth's stratosphere. RP PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08544 USA. NR 43 TC 2 Z9 2 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1991 VL 21 IS 9 BP 1259 EP 1270 DI 10.1175/1520-0485(1991)021<1259:MCHPCT>2.0.CO;2 PG 12 WC Oceanography SC Oceanography GA GM788 UT WOS:A1991GM78800002 ER PT J AU YANIV, SL SAWLA, A PETERS, M AF YANIV, SL SAWLA, A PETERS, M TI SUMMARY OF THE INTERCOMPARISON OF THE FORCE STANDARD MACHINES OF THE NATIONAL-INSTITUTE-OF-STANDARDS-AND-TECHNOLOGY, USA, AND THE PHYSIKALISCH-TECHNISCHE-BUNDESANSTALT, GERMANY SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE DEADWEIGHT MACHINES; FORCE MEASUREMENTS; FORCE STANDARDS; FORCE TRANSDUCERS AB A comparison of force measurements performed at the National Institute of Standards and Technology, USA, and at the Physikalisch-Technische Bundesanstalt, Germany is reported. The focus of the study was the intercomparison of the forces realized by the two Institutes rather than the measurement process. The transfer standards used in the comparison consisted of force transducers and associated readout instrumentation. The results of the intercomparison reveal that over a range of 50 kN to 4.5 MN, the forces realized at NIST and at PTB compare favorably. For forces up to 900 kN the agreement is within +/- 40 ppm; above 900 kN the agreement is within +/- 100 ppm. C1 PHYS TECH BUNDESANSTALT, PTB FORCE LAB, W-3300 BRAUNSCHWEIG, GERMANY. RP YANIV, SL (reprint author), NATL INST STAND & TECHNOL, MFG ENGN LAB, FORCE GRP, GAITHERSBURG, MD 20899 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 529 EP 540 DI 10.6028/jres.096.029 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100001 PM 28184127 ER PT J AU MITCHELL, GD BELL, AA AF MITCHELL, GD BELL, AA TI ACCURATE AND PRECISE COULOMETRIC DETERMINATION OF SULFUR-DIOXIDE IN COMPRESSED GAS-MIXTURES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ACID RAIN; ANALYSIS OF GASES; COMPRESSED GAS; COULOMETRY; SULFUR DIOXIDE ID AIR AB Coulometry has been established as an important and reliable method for the determination of acidic compounds. The analytical method and simple apparatus described here are applied to the precise and accurate determination of sulfur dioxide in nitrogen, specifically in compressed gas cylinders at nominal concentrations of 50 and 100-mu-mol/mol (ppm). This method is constant current coulometry where the magnitude of the current is set by the balance between the electrochemical generation of OH-, the flow of SO2, and the chemical reaction of the solution. The method is direct, rapid, and can be refined further to provide analysis at the nanomol/mol level. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV SURFACE MICROANAL SCI,GAITHERSBURG,MD 20899. RP MITCHELL, GD (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPT OF DOCUMENTS, WASHINGTON, DC 20402-9325 SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 541 EP 546 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100002 PM 28184128 ER PT J AU MITCHELL, GD BELL, AA AF MITCHELL, GD BELL, AA TI DEVELOPMENT OF A COULOMETRIC METHOD FOR ASSESSING THE CONCENTRATION OF AMBIENT LEVELS OF CO2/AIR IN COMPRESSED GAS-MIXTURES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CARBON DIOXIDE; COULOMETRY; CURRENT EFFICIENCY; CYLINDER GASES; MONOETHANOLAMINE; N,N-DIMETHYLFORMATIDE AB The coulometric method presented here is a reliable method for the direct analysis of CO2/air cylinder gas mixtures. It is based on Faraday's laws of electrolysis and therefore no external standardization is required. A series of CO2/air cylinder gas mixtures ranging in concentration from 300 to 375-mu-mol/mol (ppm) were analyzed and the results compared to those results obtained by non-dispersive infrared (NDIR) analysis with traceability to gravimetric standards. The coulometric method is rapid, sensitive, precise, and with the proper experimental controls, will yield accurate results. C1 NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, DIV SURFACE MICROANAL SCI, GAITHERSBURG, MD 20899 USA. RP MITCHELL, GD (reprint author), NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, DIV ORGAN ANALYT RES, GAITHERSBURG, MD 20899 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 547 EP 550 DI 10.6028/jres.096.031 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100003 PM 28184129 ER PT J AU HARTMAN, AW DOIRON, TD HEMBREE, GG AF HARTMAN, AW DOIRON, TD HEMBREE, GG TI CERTIFICATION OF NIST SRM 1961 - 30-MU-M DIAMETER POLYSTYRENE SPHERES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ELECTRON MICROSCOPY; MICROSPHERES; OPTICAL MICROSCOPY; PARTICLE SIZE; POLYSTYRENE; STANDARD REFERENCE MATERIALS AB This report describes the certification of SRM 1961, an NIST Standard Reference Material for particle diameter. It consists of an aqueous suspension of monosize 30-mu-m diameter polystyrene spheres. The primary technique used optical microscopy; it gave a mean diameter value DBAR = 29.62+/-0.04-mu-m and a standard deviation of the size distribution sigma(D) = 0.21-mu-m. Over 2000 spheres were measured, The supporting technique used electron microscopy, which yielded DBAR = 29.68+/-0.11-mu-m. Ninety spheres were measured. RP HARTMAN, AW (reprint author), NATL INST STAND & TECHNOL, DIV PRECIS ENGN, GAITHERSBURG, MD 20899 USA. NR 9 TC 6 Z9 8 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 551 EP 563 DI 10.6028/jres.096.032 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100004 PM 28184130 ER PT J AU DOMICH, PD BAKERJARVIS, J GEYER, RG AF DOMICH, PD BAKERJARVIS, J GEYER, RG TI OPTIMIZATION TECHNIQUES FOR PERMITTIVITY AND PERMEABILITY DETERMINATION SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE HIGHER ORDER MODES; MICROWAVE; PERMEABILITY; PERMITTIVITY; PRIMARY MODE; ORTHOGONAL DISTANCE REGRESSION; SCATTERING MATRIX AB This paper discusses optimization techniques for the determination of complex permittivity and permeability in transmission lines. The traditional theoretical model using scattering parameters is extended into a mathematical regression model that can be solved with widely accepted numerical techniques. This new model produces accurate primary mode results for the samples tested including nonmagnetic and magnetic materials with high dielectric constants. An extension of the model includes responses due to higher order modes. The general model determines parameters to specify the spectral functional form of complex permittivity and permeability and is capable of small corrections to independent variable data including angular frequency, sample length, sample position, and cutoff wavelength. The method provides reliable determination for both low and high permittivity materials. C1 NATL INST STAND & TECHNOL, ELECTR & ELECT ENGN LAB, DIV ELECTROMAGNET FIELDS, BOULDER, CO 80303 USA. RP DOMICH, PD (reprint author), NATL INST STAND & TECHNOL, COMP & APPL MATH LAB, DIV APPL & COMPUTAT LAB, BOULDER, CO 80303 USA. NR 7 TC 2 Z9 2 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 565 EP 575 DI 10.6028/jres.096.033 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100005 PM 28184131 ER PT J AU KACKER, RN LAGERGREN, ES FILLIBEN, JJ AF KACKER, RN LAGERGREN, ES FILLIBEN, JJ TI TAGUCHI ORTHOGONAL ARRAYS ARE CLASSICAL DESIGNS OF EXPERIMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE DIFFERENCE SETS; FRACTIONAL FACTORIAL PLANS; ORTHOGONAL ARRAYS; TAGUCHI METHODS ID MAIN-EFFECT PLANS; ASYMMETRICAL FACTORIALS AB Taguchi's catalog of orthogonal arrays is based on the mathematical theory of factorial designs and difference sets developed by R. C. Bose and his associates. These arrays evolved as extensions of factorial designs and latin squares. This paper (1) describes the structure and constructions of Taguchi's orthogonal arrays, (2) illustrates their fractional factorial nature, and (3) points out that Taguchi's catalog can be expanded to include orthogonal arrays developed since 1960. RP KACKER, RN (reprint author), NATL INST STAND & TECHNOL, COMP & APPL MATH LAB, DIV STAT ENGN, GAITHERSBURG, MD 20899 USA. NR 14 TC 24 Z9 24 U1 0 U2 5 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 577 EP 591 DI 10.6028/jres.096.034 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100006 PM 28184132 ER PT J AU GREGORY, TM CHOW, LC CAREY, CM AF GREGORY, TM CHOW, LC CAREY, CM TI A MATHEMATICAL-MODEL FOR DENTAL-CARIES - A COUPLED DISSOLUTION-DIFFUSION PROCESS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CA FLUX; COMPUTER SIMULATION; COUPLED DISSOLUTION-DIFFUSION; DENTAL CARIES; HYDROXYAPATITE; P-FLUX; PERMSELECTIVE DIFFUSION ID ENAMEL; DEMINERALIZATION; INVITRO; SIMULATION; SOLUBILITY; ACID AB Demineralization of tooth mineral in the caries process was studied using a computer model that simulates a diffusion controlled dissolution process. The model consists of a two-compartment system. An acidic solution in the outer ("plaque") compartment was assumed to be large in volume so that its composition remained constant during the process. The solution in the inner ("lesion") compartment was in equilibrium with thc tooth mineral, but its composition changed in response to diffusion of ions between the two solutions through an infinitely thin barrier. The permselectivity of the diffusion barrier to cations and anions can bc modified as desired thus allowing the effects of membrane on the diffusion-dissolution process to be examined. Because the losses of calcium (Ca) and phosphate (P) from the "lesion" to the "plaque" generally does not occur at a molar ratio of 5/3, the Ca to P ratio of the dissolving mineral, the composition of the "lesion" fluid can change significantly from the starting composition, and this in turn modifies the Ca and P fluxes. A steady state condition is eventually reached under which the ratio of flux of Ca to that of P becomes 5/3. The results of thc simulation show that for a given "plaque" pH, the rate of demineralization at steady state was the highest for cation and the lowest for anion permselective membranes. These results were in good agreement with those from an experimental study under comparable conditions. RP GREGORY, TM (reprint author), NATL INST STAND & TECHNOL, PAFFENBARGER RES CTR, AMER DENT ASSOC HLTH FDN, GAITHERSBURG, MD 20899 USA. NR 34 TC 8 Z9 8 U1 1 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 593 EP 604 DI 10.6028/jres.096.035 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100007 PM 28184133 ER PT J AU BELANGER, BC URIANO, GA KAMMER, RG AF BELANGER, BC URIANO, GA KAMMER, RG TI THE ADVANCED TECHNOLOGY PROGRAM - A NEW ROLE FOR NIST IN ACCELERATING THE DEVELOPMENT OF COMMERCIALLY IMPORTANT TECHNOLOGIES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ADVANCED TECHNOLOGY; COOPERATIVE AGREEMENTS; EXTRA MURAL; GENERIC TECHNOLOGY; INDUSTRIAL COMPETITIVENESS AB The Advanced Technology Program (ATP) is a new extra mural program operated by the National Institute of Standards and Technology (NIST) for the Department of Commerce's Technology Administration. The ATP will help enhance U.S. competitiveness by funding the development of precompetitive, generic technologies in partnership with industry. This paper describes the ATP, the first ATP awards made by NIST, and the prognosis for the success of the ATP. RP BELANGER, BC (reprint author), NATL INST STAND & TECHNOL, ADV TECHNOL PROGRAM, GAITHERSBURG, MD 20899 USA. NR 0 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 SEP-OCT PY 1991 VL 96 IS 5 BP 605 EP 611 DI 10.6028/jres.096.036 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100008 PM 28184134 ER PT J AU VALKIERS, S DEBIEVRE, P LENAERS, G PEISER, HS AF VALKIERS, S DEBIEVRE, P LENAERS, G PEISER, HS TI SILICON REFERENCE MATERIALS CERTIFIED FOR ISOTOPE ABUNDANCES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Letter DE ABSOLUTE ABUNDANCES; ATOMIC WEIGHTS; ISOTOPE ABUNDANCES; ISOTOPIC MASS SPECTROMETRY; ISOTOPE REFERENCE MATERIALS; SILICON; SILICON TETRAFLUORIDE AB In a series of gas mass-spectrometric measurements performed near the highest attainable accuracy, samples from two highly homogeneous batches of silicon crystals and silica powder were compared directly with a synthetic mixture of the three stable isotopes of silicon. Thereby, this work not only established the "absolute" atomic weight of these batches, but also makes portions of these batches available as an Isotopic Reference Material for accurate isotopic abundance measurements in geochemical and other isotope-abundance studies of silicon. C1 UNIV INSTELLING ANTWERP, DEPT CHEM, B-2610 WILRIJK, BELGIUM. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RP VALKIERS, S (reprint author), COMMISS EUROPEAN COMMUNITIES, JOINT RES CTR, CENT BUR NUCL MEASUREMENTS, B-2440 GEEL, BELGIUM. RI LENAERS, Guy/K-2421-2015 NR 6 TC 6 Z9 6 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1991 VL 96 IS 5 BP 617 EP 619 DI 10.6028/jres.096.038 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100010 PM 28184136 ER PT J AU CHANG, SS HUNSTON, DL AF CHANG, SS HUNSTON, DL TI 2ND INDUSTRY WORKSHOP ON POLYMER COMPOSITE PROCESSING GAITHERSBURG, MD MAY 18, 1990 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP CHANG, SS (reprint author), NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. NR 9 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 SEP-OCT PY 1991 VL 96 IS 5 BP 623 EP 631 DI 10.6028/jres.096.040 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100012 PM 28184138 ER PT J AU NEWTON, J AF NEWTON, J TI DATA-ADMINISTRATION-MANAGEMENT-ASSOCIATION SYMPOSIUM - GAITHERSBURG, MD MAY 14-15, 1991 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP NEWTON, J (reprint author), NATL INST STAND & TECHNOL, COMP SYST LAB, 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 SEP-OCT PY 1991 VL 96 IS 5 BP 633 EP 635 DI 10.6028/jres.096.041 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA HY881 UT WOS:A1991HY88100013 PM 28184139 ER PT J AU LANZEROTTI, LJ MAURER, DW SAUER, HH ZWICKL, RD AF LANZEROTTI, LJ MAURER, DW SAUER, HH ZWICKL, RD TI LARGE SOLAR PROTON EVENTS AND GEOSYNCHRONOUS COMMUNICATION SPACECRAFT SOLAR-ARRAYS SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Note ID ENERGETIC PARTICLES C1 NOAA,SPACE ENVIRONM LAB,DIV RES,BOULDER,CO 80303. AT&T BELL LABS,TECH STAFF,CRANBURY,NJ 08512. RP LANZEROTTI, LJ (reprint author), AT&T BELL LABS,TECH STAFF,MURRAY HILL,NJ 07974, USA. NR 19 TC 7 Z9 7 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 1991 VL 28 IS 5 BP 614 EP 616 DI 10.2514/3.26289 PG 3 WC Engineering, Aerospace SC Engineering GA GM559 UT WOS:A1991GM55900021 ER PT J AU GARCIA, A PENLAND, C AF GARCIA, A PENLAND, C TI FLUCTUATING HYDRODYNAMICS AND PRINCIPAL OSCILLATION PATTERN-ANALYSIS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT NATO ADVANCED RESEARCH WORKSHOP ON NONLINEAR DYNAMICAL STRUCTURES IN SIMPLE AND COMPLEX LIQUIDS CY JUN 26-29, 1990 CL LOS ALAMOS, NM SP NATO DE FLUCTUATING HYDRODYNAMICS; RAYLEIGH-BENARD CONVECTION; LANGEVIN EQUATION; PRINCIPAL OSCILLATION PATTERN ANALYSIS ID RAYLEIGH-BENARD CONVECTION; INITIAL-STAGES; INSTABILITY; GAS AB Principal oscillation pattern (POP) analysis was recently introduced into climatology to analyze multivariate time series x(i)(t) produced by systems whose dynamics are described by a linear Markov process x = Bx + xi. The matrix B gives the deterministic feedback and xi is a white noise vector with covariances = Q(ij)delta (t - t'). The POP method is applied to data from a direct simulation Monte Carlo program. The system is a dilute gas with 50,000 particles in a Rayleigh-Benard configuration. The POP analysis correctly reproduces the linearized Navier-Stokes equations (in the matrix B) and the stochastic fluxes (in the matrix Q) as given by Landau-Lifschitz fluctuating hydrodynamics. Using this method, we find the Landau-Lifschitz theory to be valid both in equilibrium and near the critical point of Rayleigh-Benard convection. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP GARCIA, A (reprint author), SAN JOSE STATE UNIV,DEPT PHYS,SAN JOSE,CA 95192, USA. NR 20 TC 42 Z9 43 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD SEP PY 1991 VL 64 IS 5-6 BP 1121 EP 1132 DI 10.1007/BF01048818 PG 12 WC Physics, Mathematical SC Physics GA GG113 UT WOS:A1991GG11300017 ER PT J AU MANDEL, J AF MANDEL, J TI MODELS AND INTERACTIONS SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE ANALYSIS OF VARIANCE; INTERACTIONS; INTERLABORATORY TESTING; LINEAR MODEL AB It is shown that the usual analysis-of-variance model with interaction terms can be a hindrance to the understanding of data rather than a useful tool. An alternative model, especially useful for the analysis of interlaboratory test data, is discussed. However, the best treatment of certain types of data is obtained by an analysis that involves minimal prior assumptions. An example is discussed that illustrates the thesis of this paper. RP MANDEL, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD SEP PY 1991 VL 19 IS 5 BP 398 EP 402 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA GD764 UT WOS:A1991GD76400008 ER PT J AU WITTMANN, RC YAGHJIAN, AD AF WITTMANN, RC YAGHJIAN, AD TI SPHERICAL-WAVE EXPANSIONS OF PISTON-RADIATOR FIELDS SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID AXISYMMETRIC TRANSDUCERS; BAFFLED PISTON; NEARFIELD; BOUNDARY AB Simple spherical-wave expansions of the continuous-wave fields of a circular piston radiator in a rigid baffle are derived. These expansions are valid throughout the illuminated half-space and are useful for efficient numerical computation in the near-field region. Multipole coefficients are given by closed-form expressions which can be evaluated recursively. C1 USAF,ERCT,ROME LAB,BEDFORD,MA 01731. RP WITTMANN, RC (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 36 TC 9 Z9 9 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 1991 VL 90 IS 3 BP 1647 EP 1655 DI 10.1121/1.401905 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA GE466 UT WOS:A1991GE46600048 PM 1939909 ER PT J AU QUINN, GD MORRELL, R AF QUINN, GD MORRELL, R TI DESIGN-DATA FOR ENGINEERING CERAMICS - A REVIEW OF THE FLEXURE TEST SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Review ID ADVANCED STRUCTURAL CERAMICS; PRESSED SILICON-NITRIDE; FRACTURE MECHANISM MAPS; STRESS RUPTURE STRENGTH; DAMAGE-INDUCED DECREASE; CREEP DEFORMATION; NONLINEAR DEFORMATION; ELEVATED-TEMPERATURES; BRITTLE MATERIALS; UNIAXIAL TENSILE AB The uniaxial strength of engineering ceramics is often measured by the well-known flexure strength test method. There is a risk that flexure data are not representative of the properties of fabricated components. Reliability estimates for components based upon statistical extrapolation techniques from flexure data may not be valid. This paper reviews the problem and judges the usefulness of flexure data for design purposes. It is shown that some of the limitations of flexure data apply to other modes of testing, including direct tension testing. C1 NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. RP QUINN, GD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Morrell, Roger/F-8468-2011 NR 157 TC 116 Z9 118 U1 1 U2 17 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2037 EP 2066 DI 10.1111/j.1151-2916.1991.tb08259.x PG 30 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600001 ER PT J AU BECHER, PF FULLER, ER ANGELINI, P AF BECHER, PF FULLER, ER ANGELINI, P TI MATRIX-GRAIN-BRIDGING CONTRIBUTIONS TO THE TOUGHNESS OF WHISKER-REINFORCED CERAMICS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE-RESISTANCE MECHANISM; TOUGHENING BEHAVIOR; CRACK-RESISTANCE; SILICON-CARBIDE; SIZE DEPENDENCE; SIC WHISKERS; ALUMINA; COMPOSITES; ANISOTROPY; ENERGY AB The fracture toughness of whisker-reinforced, noncubic ceramic matrices increases with increases in matrix grain size, d, as well as with increases in whisker content. An analytical description for the grain-bridging toughening contribution is combined with the whisker-bridging contribution to describe the toughness of such composites. Results for SiC-whisker-reinforced alumina composites confirm both the predicted grain-size effect and the coupled toughening response in the presence of these two toughening mechanisms. C1 NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP BECHER, PF (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. NR 34 TC 32 Z9 32 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1991 VL 74 IS 9 BP 2131 EP 2135 DI 10.1111/j.1151-2916.1991.tb08271.x PG 5 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600013 ER PT J AU ROTH, RS HWANG, NM RAWN, CJ BURTON, BP RITTER, JJ AF ROTH, RS HWANG, NM RAWN, CJ BURTON, BP RITTER, JJ TI PHASE-EQUILIBRIA IN THE SYSTEMS CAO-CUO AND CAO-BI2O3 SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CRYSTAL-CHEMISTRY; BULK SUPERCONDUCTIVITY; O SYSTEM; COMPOUND AB New data are presented on the phase equilibria of the binary systems CaO-CuO and CaO-Bi2O3. Corrected compositions are reported for Ca4Bi6O13 and Ca2Bi2O5 and a new metstable high-temperature phase is reported for a composition near Ca6Bi7O16.5. The composition and decomposition temperatures for Ca1-xCuO2 are given for both air and 1 atm of oxygen at 755 +/- 5-degrees and 835 +/- 5-degrees-C, respectively. RP ROTH, RS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 23 TC 51 Z9 52 U1 0 U2 3 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 SEP PY 1991 VL 74 IS 9 BP 2148 EP 2151 DI 10.1111/j.1151-2916.1991.tb08274.x PG 4 WC Materials Science, Ceramics SC Materials Science GA GF916 UT WOS:A1991GF91600016 ER PT J AU ICENHOUR, TP VANDOLAH, FM AF ICENHOUR, TP VANDOLAH, FM TI A RAPID METHOD FOR ANALYSIS OF TERT-BUTYL HYDROQUINONE (TBHQ) IN ETHYL-ESTERS OF FISH OIL SO JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY LA English DT Article DE FISH OIL ETHYL ESTERS; PHENOLIC ANTIOXIDANT; SILYL DERIVATIZATION; TERT-BUTYL HYDROQUINONE ID LIQUID-CHROMATOGRAPHIC DETERMINATION; GAS-CHROMATOGRAPHY; VEGETABLE-OILS; ANTIOXIDANTS; FATS; BHA; GALLATE AB A rapid, quantitative gas chromatographic method is described for quantitating the phenolic antioxidant, tertbutyl hydroquinone (TBHQ), in fish oil ethyl esters. The procedure entails silyl derivatization of TBHQ in an acetonitrile solution of ethyl esters followed by capillary gas chromatography (GC) analysis with an internal standard method of quantitation. Average recoveries of spiked samples were 98% at the legal limit of .02% (200-mu-g/g). The method can accurately determine as little as 20-mu-g/g of TBHQ in ethyl esters of fish oil. The technique has been applied to ethyl esters of vegetable oils with equal success. C1 US NATL MARINE FISHERIES SERV,CHARLESTON LAB,CHARLESTON,SC 29412. NR 18 TC 9 Z9 10 U1 0 U2 1 PU AMER OIL CHEMISTS SOC PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 SN 0003-021X J9 J AM OIL CHEM SOC JI J. Am. Oil Chem. Soc. PD SEP PY 1991 VL 68 IS 9 BP 659 EP 661 DI 10.1007/BF02662289 PG 3 WC Chemistry, Applied; Food Science & Technology SC Chemistry; Food Science & Technology GA GF802 UT WOS:A1991GF80200008 ER PT J AU STEIN, SE AUSLOOS, P LIAS, SG AF STEIN, SE AUSLOOS, P LIAS, SG TI COMPARATIVE EVALUATIONS OF MASS-SPECTRAL DATABASES SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article AB This Communication presents a statistical analysis of the distributions of the National Institute of Standards and Technology/Environmental Protection Agency/Mass Spectrometry Data Center Mass Spectral Database and the Wiley Registry of Mass Spectra according to sizes (peaks per spectrum) of spectra. The differences in the distributions are explained in terms of the different philosophies under which the two databases were built. The Wiley Registry is a collection that attempts to include all available spectra, including spectra of unique compounds derived from the literature. The NIST collection selects primarily spectra of interest for chemical analysis. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. NR 4 TC 15 Z9 16 U1 4 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD SEP-OCT PY 1991 VL 2 IS 5 BP 441 EP 443 DI 10.1016/1044-0305(91)85012-U PG 3 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA GC827 UT WOS:A1991GC82700012 PM 24242697 ER PT J AU LIPPS, FB HEMLER, RS AF LIPPS, FB HEMLER, RS TI NUMERICAL MODELING OF A MIDLATITUDE SQUALL LINE - FEATURES OF THE CONVECTION AND VERTICAL MOMENTUM FLUX SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID 3-DIMENSIONAL SIMULATION; BOUNDARY-CONDITION; TRAILING REGION; STRATIFORM RAIN; WIND SHEAR; STORM; CUMULONIMBUS; TRANSPORTS; CUMULUS; RADAR AB A 4-h simulation is carried out for the 22 May 1976 squall line that passed through the mesonetwork of the National Severe Storm Laboratory in central Oklahoma. This squall line was more than 100 km wide, oriented north-south and traveled eastward at approximately 14 m s-1. It produced rainfall of 2-h duration at surface stations. The simulation was obtained from a three-dimensional convective cloud model with open lateral boundary conditions on the east and west, and periodic conditions on the north and south boundaries. The model domain is 96 km long (east-west) and 32 km wide (north-south) with a horizontal grid resolution of 1.0 km and a vertical resolution of 0.5 km. A squall line develops and moves eastward at 13.7 m s-1 during the last two hours of the simulation. The present meso-gamma-scale model, however, can only simulate the leading edge of the squall line, with rain at specific surface locations lasting only 30 min. Realistic features of the modeled flow include the surface westerlies moving faster than the line behind the gust front, the strong easterlies in the lower cloud levels, and the cold boundary layer behind the gust front. Two-hour time means of the vertical momentum flux are calculated in a 60-km-wide domain (east-west) following the squall line. The vertical disturbance momentum flux for momentum normal to the line agrees with observations and is primarily confined to this region adjacent to the squall line. Horizontal-averaged time-mean momentum budgets are also calculated in this domain. For the normal component of momentum, this budget is in a quasi-steady state. It cannot be in a fully steady state as the gust front moves 1.2 m s-1 faster than the area of rain behind the line for the 2-h time mean. The parameterization of Schneider and Lindzen for the vertical momentum flux associated with active clouds is compared with mean data from the simulation. Their parameterization accounts for the in-cloud vertical momentum flux reasonably well, but ignores the remaining flux associated with convective-scale downdrafts, which is significant in lower levels. C1 PRINCETON UNIV,GEOPHYS FLUID DYNAM LAB,NOAA,ERL,POB 308,PRINCETON,NJ 08542. NR 31 TC 9 Z9 9 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 SEP 1 PY 1991 VL 48 IS 17 BP 1909 EP 1929 DI 10.1175/1520-0469(1991)048<1909:NMOAMS>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL942 UT WOS:A1991GL94200001 ER PT J AU ORLANSKI, I KATZFEY, J AF ORLANSKI, I KATZFEY, J TI THE LIFE-CYCLE OF A CYCLONE WAVE IN THE SOUTHERN-HEMISPHERE .1. EDDY ENERGY BUDGET SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID BAROCLINIC WAVES; BLOCKING EPISODE; PLANETARY-WAVES; FLOW; INSTABILITY; DISTURBANCES; TROPOSPHERE; CIRCULATION AB The energetics of a Southern Hemisphere cyclone wave have been analyzed using ECMWF data and the results of a limited-area model simulation. An analysis of the energy budget for a storm that developed in the eastern Pacific on 4-6 September 1987 showed the advection of the geopotential height field by the ageostrophic wind to be both a significant source and the primary sink of eddy kinetic energy. Air flowing through the wave gained kinetic energy via this term as it approached the energy maximum and then lost it upon exiting. Energy removal by diffusion, friction, and Reynolds stresses was found to be small. The most important conclusion was that, while the wave grew initially by poleward advection of heat as expected from baroclinic theory, the system evolved only up to the point where this source of eddy energy and the conversion of eddy potential to eddy kinetic energy (typically denoted "omega-alpha") was compensated for by energy flux divergence (dispersion of energy), mainly of the ageostrophic geopotential flux, v(a)phi. Energy exported in this fashion was then available for the downstream development of a secondary system. This finding seems to differ from the results of studies of the life cycle of normal-mode-type waves in zonal flows, which have been shown to decay primarily through transfer of energy to the mean flow via Reynolds stresses. However, this apparent inconsistency can be explained by the fact that while ageostrophic geopotential fluxes can also be very large in the case of individual normal modes, the waves export energy downstream at exactly the same rate as they gain from upstream. The group velocity of the 4-6 September storm, calculated from the ageostrophic geopotential height fluxes, showed that the energy packet comprising the system had an eastward group velocity slightly larger than the time-mean flow. RP ORLANSKI, I (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,FORRESTAL CAMPUS,PRINCETON,NJ 08542, USA. RI Katzfey, Jack/K-1231-2012 OI Katzfey, Jack/0000-0002-0604-8860 NR 46 TC 94 Z9 102 U1 1 U2 7 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 SEP 1 PY 1991 VL 48 IS 17 BP 1972 EP 1998 DI 10.1175/1520-0469(1991)048<1972:TLCOAC>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GL942 UT WOS:A1991GL94200005 ER PT J AU OCALLAGHAN, MJ ANDERSON, DZ AF OCALLAGHAN, MJ ANDERSON, DZ TI MULTIPLE-SCATTERING OF LIGHT WITHIN 2-DIMENSIONAL VOLUME HOLOGRAMS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID STRONG ACOUSTOOPTIC INTERACTION; PATH-INTEGRAL FORMULATION; COUPLED-WAVE THEORY; DIFFRACTION; GRATINGS AB A method for the calculation of the propagation of fields within a two-dimensional volume hologram is presented based on the Born series. This series solution has a simple physical interpretation in terms of multiple scattering. By appropriately rearranging terms of the Born series, we represent the effect of the hologram in the form of a scattering kernel. Scattered fields are obtained as an integral over the product of the scattering kernel with the input field. A differential equation is found for the kernel so that in some cases a closed-form solution is obtainable. The solution presented here is applicable to waves that satisfy the geometric-optics approximation and are nearly Bragg matched. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,DEPT PHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NR 32 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1991 VL 8 IS 9 BP 1425 EP 1433 DI 10.1364/JOSAA.8.001425 PG 9 WC Optics SC Optics GA GC968 UT WOS:A1991GC96800010 ER PT J AU SUGAR, J KAUFMAN, V BAIK, DH KIM, YK ROWAN, WL AF SUGAR, J KAUFMAN, V BAIK, DH KIM, YK ROWAN, WL TI ACCURATE WAVELENGTHS FOR RESONANCE LINES OF THE CU-I AND ZN-I ISOELECTRONIC-SEQUENCES FOR PD TO DY SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ENERGY-LEVELS; DIRAC-FOCK; IONS; TRANSITIONS; SPECTRA AB New measurements of the Cu-like and Zn-like resonance lines classified as 4s 2S1/2-4p 2P1/2,3/2-degrees and 4s2 1S0-4s4p 1,3P1-degrees transitions, respectively, have been made in the range of 90-335 angstrom with a wavelength uncertainty of +/- 0.005 angstrom for elements Pd to Dy. The light source was the TEXT tokamak at the Fusion Research Center in Austin, Texas. The transition energies for the Zn-like lines are compared with values calculated with the multiconfiguration Dirac-Fock code of Desclaux [Phys. Rev. A 42, 5139 (1990)], including QED corrections. Differences between corresponding theoretical and experimental values are plotted as a function of atomic number and fitted to a smooth curve. The curve is used to obtain predicted wavelength values from Tc to U. C1 UNIV TEXAS,FUS RES CTR,AUSTIN,TX 78712. KOREA ATOM RES INST,TAEJON 302353,SOUTH KOREA. RP SUGAR, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 23 TC 27 Z9 27 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1991 VL 8 IS 9 BP 1795 EP 1798 DI 10.1364/JOSAB.8.001795 PG 4 WC Optics SC Optics GA GD766 UT WOS:A1991GD76600001 ER PT J AU MCCLELLAND, JJ SCHEINFEIN, MR AF MCCLELLAND, JJ SCHEINFEIN, MR TI LASER FOCUSING OF ATOMS - A PARTICLE-OPTICS APPROACH SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID RESONANCE-RADIATION PRESSURE; MOTION; BEAM AB The use of a TEM01*-mode laser beam has been proposed as a means of focusing an atomic beam to nanometer-scale spot diameters. We have analyzed the classical trajectories of atoms through a TEM01*-mode laser beam, using methods developed for particle optics. The differential equation that describes the properties of the first-order paraxial lens has exactly the same form as the bell-shaped magnetic Newtonian lens that was first analyzed by Glaser for the focusing of electrons in an electron-microscope objective. We calculate the first-order properties of the lens, obtaining cardinal elements that are valid over the entire operating range of the lens, including the thick and the immersion regimes. Contributions to the spot size are discussed, including four aberrations plus diffraction and atomic-beam-collimation effects. Explicit expressions for spherical, chromatic, spontaneous-emission, and dipole-fluctuation aberrations are obtained. Examples are discussed for a sodium atomic beam, showing that subnanometer-diameter spots may be achieved with reasonable laser and atomic-beam parameters. Optimization of the lens is also discussed. RP MCCLELLAND, JJ (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI McClelland, Jabez/A-2358-2015 OI McClelland, Jabez/0000-0001-5672-5965 NR 17 TC 83 Z9 85 U1 0 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1991 VL 8 IS 9 BP 1974 EP 1986 DI 10.1364/JOSAB.8.001974 PG 13 WC Optics SC Optics GA GD766 UT WOS:A1991GD76600025 ER PT J AU SOBOLEWSKI, MA SEMANCIK, S HELLMAN, ES HARTFORD, EH AF SOBOLEWSKI, MA SEMANCIK, S HELLMAN, ES HARTFORD, EH TI THE EFFECTS OF OXIDATION AND AIR EXPOSURE ON RBXBA1-XBIO3 SUPERCONDUCTING THIN-FILMS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTOR; MOLECULAR-BEAM EPITAXY; SINGLE-CRYSTALS; OXYGEN; BA0.6K0.4BIO3; PHOTOEMISSION; XPS; YBA2CU3O7-X; SPECTRA AB Using x-ray photoelectron spectroscopy (XPS), we have investigated the effects of oxidation on Rb(x)Ba1-xBiO3, the degradation of its surface on exposure to air, and the feasibility of cleaning techniques to reverse this degradation. The sample was a superconducting thin film grown on MgO by molecular-beam epitaxy. XPS spectra of the initial, air-exposed surface show two O 1s peaks. The main O 1s peak increases in intensity upon oxidation at 300-degrees-C for 10 min in 100 Torr O2, and decreases upon air exposure. Also, this peak shifts, together with the Ba and Bi peaks, to lower binding energy upon oxidation. These shifts to lower binding energy upon gain of oxygen (and to higher binding energy upon oxygen loss) can be explained by a rise in the conductivity of the film with rising oxygen content. Carbon and chlorine are observed on the initial air-exposed surface. Higher binding energy contributions in the Rb XPS peaks indicate that impurity compounds containing Rb are also present. Air-exposed surfaces do not show any XPS features at the Fermi level. However, removal of C and Cl by Ar+ sputtering at 1 kV, followed by oxidation, results in the appearance of intensity at the Fermi level. Hence sputter/oxidation treatments may prove useful in restoring the surfaces of films exposed to air (during patterning, for example) prior to overlayer deposition. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RP SOBOLEWSKI, MA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 27 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1991 VL 9 IS 5 BP 2716 EP 2720 DI 10.1116/1.577231 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GG376 UT WOS:A1991GG37600022 ER PT J AU FILIPPELLI, AR DITTMANN, S AF FILIPPELLI, AR DITTMANN, S TI SEARCH FOR PRESSURE-DEPENDENCE IN THE SENSITIVITY OF SEVERAL COMMON TYPES OF HOT-CATHODE IONIZATION GAUGES FOR TOTAL PRESSURES DOWN TO 10-7 PA SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID VACUUM GAUGES; STANDARDS AB Dependence of sensitivity on pressure in He, N2, and H-2 has been investigated for a group of 16 hot-cathode ionization gauges, representing both extractor and Bayard-Alpert types for total pressure as low as 5 x 10(-8) Pa. Absolute sensitivities were determined using a primary high vacuum standard. An independent method, that of measuring the sensitivity ratio of one guage to another, was also employed. Within a scatter of about +/- 3%, +/- 4%, and +/- 4% respectively, the N2, He, and H-2 sensitivity ratio data showed no clearly discernible pressure dependence down to total pressures as small as 5 x 10(-8) Pa. The absolute sensitivity measurements in He and N2 over the range 10(-7) to 10(-3) Pa in total pressure, also were constant within a scatter of about +/- 4% and +/- 3%, respectively. As a consequence of drift in the background component of the total pressure, all the absolute sensitivity measurements at total pressures below 10(-7) Pa exhibited an apparent pressure dependence not evident in the sensitivity ratio results. In the case of H-2, drift in the pressure persisted at total pressures orders of magnitude larger than the background pressure, and for all the gauges led to an apparent difference of approximately 10% between the H-2 sensitivities at 10(-8) and 10(-5) Pa. Results of further investigation suggest that the apparent pressure dependence in the sensitivities is an artifact produced by the well-known phenomenon of thermal dissociation of H-2 at hot filaments and associated processes of H-2 pumping and production of other species such as CO and C2H4. RP FILIPPELLI, AR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 27 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1991 VL 9 IS 5 BP 2757 EP 2765 DI 10.1116/1.577195 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA GG376 UT WOS:A1991GG37600029 ER PT J AU AHRENS, JP WARD, DL AF AHRENS, JP WARD, DL TI PERFORMANCE OF BERMED REVETMENTS SO JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE LA English DT Note C1 USA,COAST ENGN RES CTR,WATERWAYS EXPT STN,VICKSBURG,MS 39180. RP AHRENS, JP (reprint author), NOAA,NATL SEA GRANT COLL PROGRAM,1335 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-950X J9 J WATERW PORT C-ASCE JI J. Waterw. Port Coast. Ocean Eng.-ASCE PD SEP-OCT PY 1991 VL 117 IS 5 BP 534 EP 540 DI 10.1061/(ASCE)0733-950X(1991)117:5(534) PG 7 WC Engineering, Civil; Engineering, Ocean; Water Resources SC Engineering; Water Resources GA GD588 UT WOS:A1991GD58800006 ER PT J AU BERGER, PW AF BERGER, PW TI ACKNOWLEDGING OUR DELUSIONS SO LIBRARY JOURNAL LA English DT Letter RP BERGER, PW (reprint author), NATL INST STAND & TECHNOL,OFF INFORMAT SERV,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 SN 0363-0277 J9 LIBR J JI Libr. J. PD SEP 1 PY 1991 VL 116 IS 14 BP 110 EP 110 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA GD760 UT WOS:A1991GD76000003 ER PT J AU BUTLER, JH ELKINS, JW AF BUTLER, JH ELKINS, JW TI AN AUTOMATED TECHNIQUE FOR THE MEASUREMENT OF DISSOLVED N2O IN NATURAL-WATERS SO MARINE CHEMISTRY LA English DT Article ID NITROUS-OXIDE; GAS-CHROMATOGRAPHY; COMBUSTION SOURCES; TRACE GASES; EL-NINO; PACIFIC; DENITRIFICATION; CONSUMPTION; SEAWATER AB We have developed a fully automated technique for measuring dissolved N2O in freshwater and seawater. This analytical system can measure N2O at intervals as short as 6 min in a virtually continuous mode, and it provides for repeat analysis where greater precision is needed. The method, which employs a modified, automated headspace sampler, involves equilibrating a small (15 ml) sample with an inert headspace, subsampling the headspace, and injecting it into an electron capture-gas chromatograph configured for back-flushing. The method is precise to +/- 2% (1 SD) and has been used for more than 3000 measurements of N2O in the Pacific Ocean, Indian Ocean, and Black Sea. It also has been used to measure N2O dissolved in surface water and groundwater. On a recent cruise to the east Pacific Ocean, we were able to analyze up to 125 samples per day, limited mainly by the frequency of hydrocasts. RP BUTLER, JH (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. NR 28 TC 37 Z9 50 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD SEP PY 1991 VL 34 IS 1-2 BP 47 EP 61 DI 10.1016/0304-4203(91)90013-M PG 15 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA GG736 UT WOS:A1991GG73600003 ER PT J AU GRIMES, CB FINUCANE, JH AF GRIMES, CB FINUCANE, JH TI SPATIAL-DISTRIBUTION AND ABUNDANCE OF LARVAL AND JUVENILE FISH, CHLOROPHYLL AND MACROZOOPLANKTON AROUND THE MISSISSIPPI RIVER DISCHARGE PLUME, AND THE ROLE OF THE PLUME IN FISH RECRUITMENT SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article ID SHAD ALOSA-SAPIDISSIMA; CONNECTICUT RIVER; CLASS STRENGTH; UNITED-STATES; GROWTH; WATER; ZOOPLANKTON; TRANSPORT; MACKEREL; GULF AB In September 1986, we collected neuston (1 x 2 m, 0.947 mm mesh) and surface chlorophyll a samples and hydrographic data at 46 stations around the discharge plume of the Mississippi River. Transects were positioned so that the 3 water masses in the plume area - plume water, Gulf of Mexico shelf water and frontal water (a mixture of the former 2) - were sampled. The plume was represented by a shallow lens of water < 34% salinity and < 29-degrees-C resting atop warmer (> 29-degrees-C) and more saline (> 34%) Gulf of Mexico shelf water. Strong turbidity fronts with a scale of 50 to 100 m form, relax and reform approximately at tidal frequencies within the frontal region that has a larger scale of 6 to 8 km. Total ichthyoplankton catch per tow, individual surface chlorophyll a values and macrozooplankton displacement volumes were all significantly greater in frontal waters than adjacent Gulf of Mexico shelf or plume waters. Hydrodynamic convergence at the continually forming and relaxing turbidity fronts most likely accounts for concentrated neustonic ichthyoplankton, and at least partially for high macrozooplankton values as well, in frontal waters. Elevated macrozooplankton displacement volumes in frontal waters may also result from higher rates of proliferation of macrozooplankton biomass. High primary production in frontal water is probably due to the mixing of nutrient-rich, but turbid, plume water (where photosynthesis is light limited) with clear, but nutrient-poor, Gulf of Mexico shelf water (where photosynthesis is nutrient limited) creating favorable phytoplankton growth conditions. Concentrations of ichthyoplankton and zooplankton offer rich trophic resources that some species utilize to gain superior growth. Faster growth will lead to increased survival and recruitment (because larvae pass through the period of greatest vulnerability to predation by gape-limited predators more quickly) if larval growth is increased disproportionately to larval mortality from predation. RP GRIMES, CB (reprint author), NATL MARINE FISHERIES SERV, 3500 DELWOOD BEACH RD, PANAMA CITY, FL 32408 USA. NR 59 TC 97 Z9 100 U1 3 U2 14 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD SEP PY 1991 VL 75 IS 2-3 BP 109 EP 119 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA GG435 UT WOS:A1991GG43500001 ER PT J AU STALICK, JK GOTAAS, JA CHENG, SF CULLEN, J CLARK, AE AF STALICK, JK GOTAAS, JA CHENG, SF CULLEN, J CLARK, AE TI CRYSTALLOGRAPHIC AND MAGNETIC-STRUCTURE OF PR2FE17N2.8 SO MATERIALS LETTERS LA English DT Article ID INTERMETALLIC COMPOUNDS; CRYSTAL AB A neutron Rietveld refinement study of nitrided Pr2Fe17 at room temperature and at 4 K shows that the basic Th2Zn17 structure is maintained, with the N atoms occupying the interstitial 9e sites. Pr2Fe17N2.8 is rhombohedral, space group R3mBAR, with a = 8.776(1) angstrom, c = 12.649(2) angstrom at 4 K and a = 8.794(1) angstrom, c = 12.668(2) angstrom at 295 K. At both temperatures the easy magnetization direction is perpendicular to the c axis. C1 USN, CTR SURFACE WARFARE, SILVER SPRING, MD 20903 USA. RP STALICK, JK (reprint author), NATL INST STAND & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. NR 20 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X EI 1873-4979 J9 MATER LETT JI Mater. Lett. PD SEP PY 1991 VL 12 IS 1-2 BP 93 EP 96 DI 10.1016/0167-577X(91)90064-D PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA GJ921 UT WOS:A1991GJ92100019 ER PT J AU GALLAWA, RL GARDNER, JL NETTLETON, DH STOCK, KD WARD, TH LI, XY AF GALLAWA, RL GARDNER, JL NETTLETON, DH STOCK, KD WARD, TH LI, XY TI PILOT-STUDY FOR THE INTERNATIONAL INTERCOMPARISON OF RESPONSIVITY SCALES AT FIBER OPTIC WAVELENGTHS SO METROLOGIA LA English DT Article; Proceedings Paper CT 3RD MEETING ON NEW DEVELOPMENTS AND APPLICATIONS IN OPTICAL RADIOMETRY CY SEP 20-22, 1990 CL DAVOS, SWITZERLAND SP PHYSIKALISCH METEOROLOG OBSERV DAVOS ID FIBER POWER METERS AB A pilot international intercomparison of spectral responsivity scales at wavelengths important to fibre optics communication was undertaken among national laboratories in the USA, the UK, Germany and Australia. Results are reported for wavelengths of 800 nm, 850 nm, 1 300 nm and 1 550 nm. Based on this study, a larger intercomparison is planned for 1 300 nm and 1 550 nm, using selected germanium photodiodes as transfer standards. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. CSIRO,LINDFIELD,NSW 2070,AUSTRALIA. NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. PHYS TECH BUNDESANSTALT,W-3300 BRAUNSCHWEIG,GERMANY. NR 16 TC 2 Z9 2 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD SEP PY 1991 VL 28 IS 3 BP 151 EP 154 DI 10.1088/0026-1394/28/3/009 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB184 UT WOS:A1991JB18400010 ER PT J AU GEIST, J CHANDLERHOROWITZ, D KOHLER, R ROBINSON, AM JAMES, CR AF GEIST, J CHANDLERHOROWITZ, D KOHLER, R ROBINSON, AM JAMES, CR TI NUMERICAL MODELING OF SHORT-WAVELENGTH INTERNAL QUANTUM EFFICIENCY SO METROLOGIA LA English DT Article; Proceedings Paper CT 3RD MEETING ON NEW DEVELOPMENTS AND APPLICATIONS IN OPTICAL RADIOMETRY CY SEP 20-22, 1990 CL DAVOS, SWITZERLAND SP PHYSIKALISCH METEOROLOG OBSERV DAVOS ID SELF-CALIBRATION; PHOTODIODE AB Results of numerical modelling of short-wavelength, internal quantum efficiency of two types of p+nn+ silicon photodiode are presented. The important conclusions are: (1) interpreting the data obtained from oxide-bias experiments with the help of numerical quantum efficiency models will provide higher accuracy than can be obtained from the conventional self-calibration formula; (2) for high-quality silicon photodiodes, the spectral shape of the internal quantum deficiency (one minus the quantum efficiency) is virtually independent of the density of charge trapped in the oxide, and of the surface-recombination velocity at the oxide-silicon interface. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BUR INT POIDS & MESURES,F-92312 SEVRES,FRANCE. UNIV ALBERTA,EDMONTON T6G 2G7,ALBERTA,CANADA. RI Geist, Jon/D-5386-2013 NR 7 TC 11 Z9 11 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 PD SEP PY 1991 VL 28 IS 3 BP 193 EP 196 DI 10.1088/0026-1394/28/3/017 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB184 UT WOS:A1991JB18400018 ER PT J AU MIGDALL, AL ROOP, B XIA, GJ AF MIGDALL, AL ROOP, B XIA, GJ TI MEASURING FILTER TRANSMITTANCE USING HETERODYNE-DETECTION SO METROLOGIA LA English DT Article; Proceedings Paper CT 3RD MEETING ON NEW DEVELOPMENTS AND APPLICATIONS IN OPTICAL RADIOMETRY CY SEP 20-22, 1990 CL DAVOS, SWITZERLAND SP PHYSIKALISCH METEOROLOG OBSERV DAVOS ID RANGE AB We use heterodyne detection to measure optical transmittance over an unprecedented dynamic range, with high accuracy and high sensitivity. Our set-up uses a Mach-Zehnder interferometer with acousto-optic frequency shifting to produce a 30 MHz frequency difference between the two light beams, resulting in a beat envelope on the interferometer output beam. We determine the optical transmittance of a filter by inserting it into one of the interferometer arms and measuring the change in amplitude of the optical beat signal. This method allows direct comparison between optical and RF attenuators, ultimately tying optical transmittance measurements to 30 MHz RF attenuation standards in an absolute way. Using this method, we have measured filters that cover 12 decades of transmittance. We discuss a recently developed instrument that improves the accuracy and dynamic range over which the optical-RF connection can be made. This instrument functions as a lock-in amplifier with a dynamic range of up to 180 dB. In addition, we extend the technique into the infrared at 10,6-mu-m, where we demonstrate that transmittances of filters at room temperature can be measured with a dynamic range of more than 11 decades. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. CHINESE ACAD SCI,SHANGHAI INST TECH PHYS,SHANGHAI,PEOPLES R CHINA. NR 3 TC 4 Z9 4 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 PD SEP PY 1991 VL 28 IS 3 BP 217 EP 220 DI 10.1088/0026-1394/28/3/022 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB184 UT WOS:A1991JB18400023 ER PT J AU STENSRUD, DJ MADDOX, RA ZIEGLER, CL AF STENSRUD, DJ MADDOX, RA ZIEGLER, CL TI A SUBLIMATION-INITIATED MESOSCALE DOWNDRAFT AND ITS RELATION TO THE WIND-FIELD BELOW A PRECIPITATING ANVIL CLOUD SO MONTHLY WEATHER REVIEW LA English DT Article ID MIDLATITUDE SQUALL LINE; 10-11 JUNE 1985; CONVECTIVE SYSTEM; DOPPLER RADAR; STRATIFORM PRECIPITATION; UNSATURATED DOWNDRAFTS; MID-LATITUDE; MELTING SNOW; REAR INFLOW; STORM AB A simple, one-dimensional model is developed to examine the potential for a sublimation-initiated mesoscale downdraft to influence the dynamics of the subanvil region by advecting horizontal momentum from a high-level precipitating anvil cloud downward into the middle or lower troposphere. Model results suggest that this vertical advection can occur on a time scale of several hours or less, although it is found to be highly dependent upon the snow mixing ratio within the overlying anvil cloud and lapse rates in the environment below. The study is motivated by an examination of data from a 50-MHz radar wind profiler on 24 June 1985 that suggests downward momentum advection from anvil base may have produced unbalanced flow in midlevels, owing to strong flow within the anvil and weak midlevel geostrophic winds. For this situation, we hypothesize that as the anvil cloud both dissipated and was advected horizontally away from the profiler site by the strong, upper-level winds, the downdraft weakened and an inertial oscillation began that slowly altered the midlevel airflow below the anvil cloud. This inertial oscillation appears to have persisted for hours after the mesoscale convective system dissipated, likely owing to the weak midlevel flow. While the model is not used to explain fully the observed profiler wind observations, the similarity between the evolution of the simulated and observed wind fields emphasizes the importance of ice microphysics to the dynamics of regions below precipitating anvil clouds. The thermodynamic structure of the model-produced atmosphere after several hours of integration resembles the onion soundings frequently behind convective systems in the tropics and midlatitudes. Previous observational studies show that the midlevel, near-saturated portion of the onion sounding is associated with mesoscale ascent. However, in the model simulations this structure is found in conjunction with mesoscale descent, suggesting that this thermodynamic signature may be associated with either midlevel ascending or descending flow fields. RP NOAA, NATL SEVERE STORMS LAB, ENVIRONM RES LABS, 1313 HALLEY CIRCLE, NORMAN, OK 73069 USA. NR 47 TC 26 Z9 26 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 1991 VL 119 IS 9 BP 2124 EP 2139 DI 10.1175/1520-0493(1991)119<2124:ASIMDA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GF876 UT WOS:A1991GF87600005 ER PT J AU SIMIC, MG BERGTOLD, DS AF SIMIC, MG BERGTOLD, DS TI DIETARY MODULATION OF DNA DAMAGE IN HUMAN SO MUTATION RESEARCH LA English DT Article DE AGING; ANTIOXIDANTS; BIOMARKERS; CALORIC RESTRICTION; DIET; DNA DAMAGE; HYDROXYL RADICAL; OXIDATIVE PROCESSES; PREVENTION OF DEGENERATIVE DISEASES; REACTIVE OXYGEN SPECIES ID OXIDATIVE DAMAGE; THYMINE GLYCOL; AGING PROCESS; CARCINOGENESIS; MUTAGENESIS; RADICALS; METABOLISM; RADIATION; CANCER; URINE AB Manipulation of human diet can modulate urinary biomarkers of oxidative DNA base damage (UBODBD), reflecting changes in levels of DNA damage. When dietary composition is maintained but caloric intake is decreased (caloric restriction), UBODBD excretion is suppressed. At isocaloric dietary intake the level of damage depends on diet composition. For diets consisting of foods containing carbohydrates, proteins, and fats but lacking fruits and vegetables, the level of damage is higher than for diets including fruits and vegetables, which are rich in natural antioxidants. Assay of urinary biomarkers is suggested as a potential test for quantitative assessment of the carcinogenic or anticarcinogenic properties of foods, food components, and diets and for individual responses to nutritional regimens. RP SIMIC, MG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 41 TC 75 Z9 75 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD SEP-OCT PY 1991 VL 250 IS 1-2 BP 17 EP 24 DI 10.1016/0027-5107(91)90158-K PG 8 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA GL878 UT WOS:A1991GL87800002 PM 1944333 ER PT J AU MOFJELD, HO AF MOFJELD, HO TI COASTAL FLOODING AND CLIMATE CHANGE IN THE PACIFIC-NORTHWEST SO NORTHWEST ENVIRONMENTAL JOURNAL LA English DT Note RP MOFJELD, HO (reprint author), PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST ENVIRON STUD PI SEATTLE PA UNIV WASHINGTON ENGINEERING ANNEX FM-12, SEATTLE, WA 98195 SN 0749-7962 J9 NORTHWEST ENVIRON J PD FAL-WIN PY 1991 VL 7 IS 2 BP 359 EP 361 PG 3 WC Ecology; Environmental Sciences; Forestry SC Environmental Sciences & Ecology; Forestry GA HU360 UT WOS:A1991HU36000022 ER PT J AU MULLINEAUX, LS WIEBE, PH BAKER, ET AF MULLINEAUX, LS WIEBE, PH BAKER, ET TI HYDROTHERMAL VENT PLUMES - LARVAL HIGHWAYS IN THE DEEP-SEA SO OCEANUS LA English DT Article C1 WOODS HOLE OCEANOG INST,PACIFIC MARINE ENVIRONM LAB,WOODS HOLE,MA 02543. RP MULLINEAUX, LS (reprint author), WOODS HOLE OCEANOG INST,DEPT BIOL,WOODS HOLE,MA 02543, USA. NR 0 TC 13 Z9 13 U1 1 U2 3 PU WOODS HOLE OCEANOGRAPHIC INST PI WOODS HOLE PA OCEANUS MAGAZINE, WOODS HOLE, MA 02543 SN 0029-8182 J9 OCEANUS JI Oceanus PD FAL PY 1991 VL 34 IS 3 BP 64 EP 68 PG 5 WC Oceanography SC Oceanography GA GU193 UT WOS:A1991GU19300010 ER PT J AU DZUBA, VA FLAMBAUM, VV GRIBAKIN, GF SUSHKOV, OP AF DZUBA, VA FLAMBAUM, VV GRIBAKIN, GF SUSHKOV, OP TI FINE-STRUCTURE OF NEGATIVE-IONS OF ALKALINE-EARTH-METAL ATOMS SO PHYSICAL REVIEW A LA English DT Article ID PERTURBATION-THEORY AB Fine-structure intervals np1/2-np3/2 (np1/2 is the ground state) are calculated for negative ions using relativistic many-body perturbation theory: Ca- 4p, 56 cm-1; Sr-1 5p, 178 cm-1; Ba- 6p, about 460 cm-1; and Ra- 7p, 1341 cm-1. Comparison of the fine-structure interval with affinity: Ca- 10%, Sr- 22%, Ba- 30%; for Ra- the fine-structure interval is larger than the affinity. Thus the Ra- 7p3/2 state is a resonance in the continuous spectrum with energy 0.018 eV. This means that the relativistic spinorbit interaction plays a determining role in slow electron-radium scattering. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. LENINGRAD STATE TECH UNIV, LENINGRAD 195251, USSR. RP DZUBA, VA (reprint author), NOVOSIBIRSK NUCL PHYS INST, NOVOSIBIRSK 630090, USSR. NR 17 TC 41 Z9 41 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 SEP 1 PY 1991 VL 44 IS 5 BP 2823 EP 2827 DI 10.1103/PhysRevA.44.2823 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600010 ER PT J AU DZUBA, VA FLAMBAUM, VV SILVESTROV, PG SUSHKOV, OP AF DZUBA, VA FLAMBAUM, VV SILVESTROV, PG SUSHKOV, OP TI MANY-BODY PERTURBATION-THEORY CALCULATIONS IN ATOMS WITH OPEN-SHELLS SO PHYSICAL REVIEW A LA English DT Article ID NONCONSERVING OPTICAL-ROTATION; PARITY NON-CONSERVATION; ENERGY-LEVELS; HYPERFINE-STRUCTURE; CESIUM ATOM; TRANSITION; BISMUTH; CONFIGURATION; SUMMATION; LEAD AB Energy intervals, g factors, and M1 amplitudes of the 6p2 configuration in Pb and the 6p3 configuration in Bi are calculated. All the corrections of second-order perturbation theory in residual electron-electron interaction are taken into account. The higher-order corrections are also investigated. In Pb we have calculated the most important corrections: the screening of external electrons interaction by closed-shell polarization. In Bi the higher-order correcations are treated semiempirically. Energy levels for a superheavy element with charge Z = 114 are also calculated. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP DZUBA, VA (reprint author), NOVOSIBIRSK NUCL PHYS INST,NOVOSIBIRSK 630090,USSR. NR 20 TC 22 Z9 22 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP 1 PY 1991 VL 44 IS 5 BP 2828 EP 2831 DI 10.1103/PhysRevA.44.2828 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GE936 UT WOS:A1991GE93600011 ER PT J AU BARBEE, TW COHEN, ML PENN, DR AF BARBEE, TW COHEN, ML PENN, DR TI EXPERIMENTAL CONSTRAINTS ON SOME MECHANISMS FOR HIGH-TEMPERATURE SUPERCONDUCTIVITY SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; CU-O SYSTEM; OXYGEN ISOTOPE; ENERGY-GAP; YBA2CU3O7; OXIDES; HEAT; LA1.85SR0.15CUO4; BI2SR2CACU2O8; CONDUCTIVITY AB Since its discovery, many mechanisms have been suggested to explain the phenomenon of high-temperature superconductivity in oxides. We propose that experimental data, along with theoretical models, can place constraints on or exclude many of these mechanisms. The isotope shift-alpha, the transition temperature T(c), the ratio of the electronic-specific-heat jump to the normal-state specific heat DELTA-C/gamma T(c), and the superconducting gap ratio 2-DELTA/k(B)T(c) are considered. We find limits on the applicability of solely phonon-based and combined phonon-electronic mechanisms. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. NATL INST STAND & TECHNOL,DIV RADIAT PHYS,GAITHERSBURG,MD 20899. RP BARBEE, TW (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 51 TC 14 Z9 14 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 SEP 1 PY 1991 VL 44 IS 9 BP 4473 EP 4479 DI 10.1103/PhysRevB.44.4473 PG 7 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700050 ER PT J AU SAMARTH, N KLOSOWSKI, P LUO, H GIEBULTOWICZ, TM FURDYNA, JK RHYNE, JJ LARSON, BE OTSUKA, N AF SAMARTH, N KLOSOWSKI, P LUO, H GIEBULTOWICZ, TM FURDYNA, JK RHYNE, JJ LARSON, BE OTSUKA, N TI ANTIFERROMAGNETISM IN ZNSE/MNSE STRAINED-LAYER SUPERLATTICES SO PHYSICAL REVIEW B LA English DT Note ID DILUTED MAGNETIC SEMICONDUCTORS; EPILAYERS AB Neutron diffraction studies of ZnSe/MnSe strained-layer superlattices with individual MnSe layer thicknesses ranging from 3 to 15 monolayers show a second-order transition to type-III antiferromagnetic order. The magnetic reflections indicate a single orientation of the type-III domain, with the tetragonal axis perpendicular to the layer plane and the spins lying within the layer plane. C1 UNIV MISSOURI,COLUMBIA,MO 65211. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. THINKING MACHINES CORP,CAMBRIDGE,MA 02215. PURDUE UNIV,SCH MAT ENGN,W LAFAYETTE,IN 47907. RP SAMARTH, N (reprint author), UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556, USA. RI Samarth, Nitin/C-4475-2014 OI Samarth, Nitin/0000-0003-2599-346X NR 14 TC 41 Z9 41 U1 3 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1991 VL 44 IS 9 BP 4701 EP 4704 DI 10.1103/PhysRevB.44.4701 PG 4 WC Physics, Condensed Matter SC Physics GA GD967 UT WOS:A1991GD96700086 ER PT J AU GRINSPOON, J BOWMAN, WD FALL, R AF GRINSPOON, J BOWMAN, WD FALL, R TI DELAYED ONSET OF ISOPRENE EMISSION IN DEVELOPING VELVET BEAN (MUCUNA SP) LEAVES SO PLANT PHYSIOLOGY LA English DT Article ID PHOTOSYNTHESIS; OZONE; PHOTORESPIRATION; HYDROCARBONS AB Isoprene (2-methyl-1,3-butadiene) is one of the major volatile hydrocarbons emitted by plants, but its biosynthetic pathway and role in plant metabolism are unknown. Mucuna sp. (velvet bean) is an isoprene emitter, and leaf isoprene emission rate increased as much as 125-fold as leaves developed, and declined in older leaves. Net CO2 assimilation and stomatal conductance, under different growth and environmental conditions, increased 3 to 5 days prior to an increase in isoprene emission rate, indicating that photosynthetic competence develops before significant isoprene emission occurs. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT ENVIRONM POPULAT & ORGANISM BIOL,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 24 TC 56 Z9 57 U1 0 U2 2 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD SEP PY 1991 VL 97 IS 1 BP 170 EP 174 DI 10.1104/pp.97.1.170 PG 5 WC Plant Sciences SC Plant Sciences GA GJ793 UT WOS:A1991GJ79300025 PM 16668365 ER PT J AU MAHAPATRA, PR ZRNIC, DS AF MAHAPATRA, PR ZRNIC, DS TI SENSORS AND SYSTEMS TO ENHANCE AVIATION SAFETY AGAINST WEATHER HAZARDS SO PROCEEDINGS OF THE IEEE LA English DT Review ID WIND SHEAR DETECTION; DOPPLER RADAR; LIGHTNING STRIKES; AIRCRAFT; MICROBURST; PRECIPITATION; POLARIZATION; AIRPLANE; THUNDERSTORMS; OPERATIONS AB Weather-related factors are among major causes of aviation hazards, passenger discomfort, poor airline schedule-keeping, and poor operating economy. A variety of new high-technology electronic sensors and systems for aviation weather are being developed and installed across the U.S. The aviation weather monitoring system of the future will be centered around Doppler weather radars which offer the best combination of coverage, resolution, and agility for this purpose, and are able to detect and estimate the severity of atmospheric air motion, including wind shear and turbulence, directly. Three major new Doppler radar systems are pertinent: the Next Generation Weather Radar, the Terminal Doppler Weather Radar, and the Airport Surveillance Radar with a dedicated weather channel. Other relatively simple new instruments for aviation weather support include the Low Level Wind Shear Alert System, the Doppler Wind Profilers, the Automated Weather Observation System, and the Automated Surface Observation System. These systems are designed to perform higher level functions such as detection, characterization, and hazard potential estimation of aviation-significant weather phenomena, as well as their communication and display automatically. Together with conventional information sources and data from improved satellite imagers and sounders, the modern dedicated weather surveillance systems hold the potential of being powerful tools in enhancing the quality of aviation well into the next century. C1 NATL SEVERE STORMS LAB, DOPPLER RADAR & REMOTE SENSING RES GRP, NORMAN, OK 73069 USA. RP INDIAN INST SCI, DEPT AEROSP ENGN, BANGALORE 560012, KARNATAKA, INDIA. NR 197 TC 8 Z9 10 U1 5 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 EI 1558-2256 J9 P IEEE JI Proc. IEEE PD SEP PY 1991 VL 79 IS 9 BP 1234 EP 1267 DI 10.1109/5.97295 PG 34 WC Engineering, Electrical & Electronic SC Engineering GA GL053 UT WOS:A1991GL05300004 ER PT J AU WICKNER, S HOSKINS, J MCKENNEY, K AF WICKNER, S HOSKINS, J MCKENNEY, K TI MONOMERIZATION OF REPA DIMERS BY HEAT-SHOCK PROTEINS ACTIVATES BINDING TO DNA-REPLICATION ORIGIN SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE DNAJ; DNAK; PLASMID P1 ID P1 PLASMID REPLICATION; ESCHERICHIA-COLI; NUCLEOPROTEIN STRUCTURES; BACTERIOPHAGE-LAMBDA; INITIATOR PROTEIN; GENE; DEFECTS; GRPE AB DnaK is a major heat shock protein of Escherichia coli and the homolog of hsp70 in eukaryotes. We demonstrate the mechanism by which DnaK and another heat shock protein, DnaJ, render the plasmid Pl initiator RepA 100-fold more active for binding to the PI origin of replication. Activation is the conversion of RepA dimers into monomers in an ATP-dependent reaction and the monomer form binds with high affinity to oriP1 DNA. Reversible chemical denaturants also convert RepA dimers to monomers and simultaneously activate oriP1 DNA binding. Increasing protein concentration converts monomers to dimers and deactivates RepA. Based on our data and previous work, we present a model for heat shock protein action under normal and stress conditions. C1 NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP WICKNER, S (reprint author), NCI,MOLEC BIOL LAB,BETHESDA,MD 20892, USA. NR 18 TC 166 Z9 167 U1 0 U2 0 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 SEP PY 1991 VL 88 IS 18 BP 7903 EP 7907 DI 10.1073/pnas.88.18.7903 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GF101 UT WOS:A1991GF10100001 PM 1896443 ER PT J AU MAY, PT YAMAMOTO, M FUKAO, S SATO, T KATO, S TSUDA, T AF MAY, PT YAMAMOTO, M FUKAO, S SATO, T KATO, S TSUDA, T TI WIND AND REFLECTIVITY FIELDS AROUND FRONTS OBSERVED WITH A VHF RADAR SO RADIO SCIENCE LA English DT Article ID PHASED-ARRAY SYSTEM; DOPPLER RADARS; MU RADAR; STRATOSPHERE; TROPOSPHERE; SCATTERING; ATMOSPHERE; LAYERS; MODEL AB The wind and VHF radar reflectivity fields around frontal zones are examined. While even weak upper level baroclinic zones can be seen in both the reflectivity and wind fields, the reflectivity signature of low level fronts may be obscured. Humidity terms dominate the refractive index gradient in the lower troposphere and can mask the enhancement of the gradient as a result of the stable frontal layers. C1 KYOTO UNIV,CTR RADIO ATMOSPHER SCI,UJI,KYOTO 611,JAPAN. KYOTO UNIV,DEPT ELECT ENGN,UJI,KYOTO 611,JAPAN. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Sato, Toru/F-3818-2012; tsuda, toshitaka/A-3035-2015 NR 23 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD SEP-OCT PY 1991 VL 26 IS 5 BP 1245 EP 1249 DI 10.1029/91RS00964 PG 5 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA GJ939 UT WOS:A1991GJ93900010 ER PT J AU VANBAELEN, JS RICHMOND, AD TSUDA, T AVERY, SK KATO, S FUKAO, S YAMAMOTO, M AF VANBAELEN, JS RICHMOND, AD TSUDA, T AVERY, SK KATO, S FUKAO, S YAMAMOTO, M TI RADAR INTERFEROMETRY TECHNIQUE AND ANISOTROPY OF THE ECHO POWER DISTRIBUTION - 1ST RESULTS SO RADIO SCIENCE LA English DT Article ID PHASED-ARRAY SYSTEM; MU RADAR; LOWER STRATOSPHERE; ANTENNA; AMPLIFIERS; ATMOSPHERE; MIDDLE; WIND AB The theory of radar interferometry developed in the companion paper [Van Baelen and Richmond, this issue] is applied to a set of measurements obtained with the middle and upper atmosphere (MU) radar in order to demonstrate the technique and to test the theory. The variations with respect to Doppler frequency of the coherencies and phases of the signals cross-correlated between receiver pairs depend on the amplitude and direction of the wind in the manner predicted by the theory. The horizontal wind derived by the interferometric technique agrees quite well with the so-called apparent velocity obtained by cross-correlating signals in the time domain from different receiver pairs, and under our experimental conditions the latter estimate has been determined to be a good representation of the true wind, in spite of slight tendencies to overestimate the wind amplitude. The vertical wind derived by the interferometric technique shows significant differences with the Doppler wind obtained from a vertically pointing antenna, but these differences disappear when the Doppler wind is corrected for the off-zenith distribution of the received power. An examination of the mean angle-of-arrival of the received signal reveals that there is a tendency for the angle to approach, though not attain, perpendicularity with the three-dimensional wind vector, and perhaps also to tend to be perpendicular to isentropes in the crosswind direction. A postset beam steering analysis of several examples of data illustrates the behavior of the angular distribution of received power in time and space. When the signal-to-noise ratio is large, there is a tendency for the power to be fairly isotropic with respect to zenith angle, but highly distorted patterns can be encountered when the signal is weaker. There appears to be a tendency for the patterns to vary relatively slowly over time, but strong variations in altitude are observed in passing from one 300-m range gate to the next. The direction of most intense received power does not necessarily correspond to the direction of mean angle-of-arrival of the signal as determined by interferometry. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309. KYOTO UNIV,CTR RADIO ATMOSPHER SCI,UJI,KYOTO 611,JAPAN. RP VANBAELEN, JS (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. RI tsuda, toshitaka/A-3035-2015 NR 21 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD SEP-OCT PY 1991 VL 26 IS 5 BP 1315 EP 1326 DI 10.1029/91RS01230 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA GJ939 UT WOS:A1991GJ93900016 ER PT J AU NELSON, PG AF NELSON, PG TI AN ACTIVE VIBRATION ISOLATION SYSTEM FOR INERTIAL REFERENCE AND PRECISION-MEASUREMENT SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We describe an active low-frequency vibration isolation system based on an earlier instrument developed at the Joint Institute for Laboratory Astrophysics (JILA). Several modifications, which have led to improved transient response, temperature stability, and a greatly reduced size, are discussed. We also comment on how the performance of the system is limited by sensor noise, mechanical resonances, and cross couplings between the different degrees of freedom. RP NELSON, PG (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 12 TC 29 Z9 30 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 1991 VL 62 IS 9 BP 2069 EP 2075 DI 10.1063/1.1142368 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600002 ER PT J AU NISHIYAMA, RT BEDARD, AJ AF NISHIYAMA, RT BEDARD, AJ TI A QUAD-DISK STATIC PRESSURE PROBE FOR MEASUREMENT IN ADVERSE ATMOSPHERES - WITH A COMPARATIVE REVIEW OF STATIC PRESSURE PROBE DESIGNS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SURFACE METEOROLOGICAL OBSERVATIONS; SEVERE THUNDERSTORMS; BOUNDARY-LAYER; TROPOSPHERE; TOTO AB There are many areas of need for accurate measurements of atmospheric static pressure. These include observations of surface meteorology, airport altimeter settings, pressure distributions around buildings, moving measurement platforms, as well as basic measurements of fluctuating pressures in turbulence. Most of these observations require long-term observations in adverse environments (e.g., rain, dust, or snow). Currently, many pressure measurements are made, of necessity, within buildings, thus involving potential errors of several milibars in mean pressure during moderate winds, accompanied by large fluctuating pressures induced by the structure. In response to these needs we designed a "Quad-Disc" pressure probe for continuous, outdoor monitoring purposes which is inherently weather protected. This Quad-Disc probe has the desirable features of omnidirectional response and small error in pitch. A review of past static pressure probes contrasts design approaches and capabilities. C1 NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP NISHIYAMA, RT (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 59 TC 31 Z9 32 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 1991 VL 62 IS 9 BP 2193 EP 2204 DI 10.1063/1.1142337 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600024 ER PT J AU GILLIS, KA MOLDOVER, MR GOODWIN, ARH AF GILLIS, KA MOLDOVER, MR GOODWIN, ARH TI ACCURATE ACOUSTIC MEASUREMENTS IN GASES UNDER DIFFICULT CONDITIONS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SPHERICAL RESONATOR; SOUND; SPEEDS AB Accurate measurements of the speed of sound in gases are often made using metal resonators with small transducers that perturb the resonance frequencies in minor and predictable ways. We extend this method to gases that may be corrosive and to high temperatures by using remote transducers coupled to a resonator by acoustic waveguides. Thin metal diaphragms separate the waveguides from the resonator. Thus, only metal parts come into contact with the test gas. In the present apparatus, any gas compatible with gold and stainless steel can be studied. RP GILLIS, KA (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 20 TC 20 Z9 20 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 1991 VL 62 IS 9 BP 2213 EP 2217 DI 10.1063/1.1142339 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GD506 UT WOS:A1991GD50600026 ER PT J AU RAO, ST KU, JY RAO, KS AF RAO, ST KU, JY RAO, KS TI SAMPLING STRATEGIES FOR TOXIC AIR CONTAMINANTS SO RISK ANALYSIS LA English DT Article; Proceedings Paper CT WORKSHOP ON RISK ASSESSMENT TECHNIQUES AND MANAGEMENT CY OCT, 1987 CL INDIAN INST TECHNOL, DELHI, INDIA SP MINIST ENVIRONM & FORESTS INDIA HO INDIAN INST TECHNOL DE AIR TOXICS SAMPLING; VARIABILITY IN POLLUTANT CONCENTRATION DATA; BOOTSTRAP RESAMPLING METHOD; ANNUAL MEAN CONCENTRATION AND 95-PERCENT CONFIDENCE INTERVAL; OC CURVES FOR SAMPLING DESIGN; T-TEST FOR COMPLIANCE HYPOTHESIS ID MODEL PERFORMANCE; POLLUTION C1 NOAA,AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,OAK RIDGE,TN 37831. RP RAO, ST (reprint author), NEW YORK STATE DEPT ENVIRONM CONSERVAT,DIV AIR RESOURCES,ALBANY,NY 12233, USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD SEP PY 1991 VL 11 IS 3 BP 441 EP 451 DI 10.1111/j.1539-6924.1991.tb00630.x PG 11 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA GJ337 UT WOS:A1991GJ33700015 PM 1947350 ER PT J AU BOETTINGER, WJ SHAPIRO, AJ CLINE, JP GAYLE, FW BENDERSKY, LA BIANCANIELLO, FS AF BOETTINGER, WJ SHAPIRO, AJ CLINE, JP GAYLE, FW BENDERSKY, LA BIANCANIELLO, FS TI INVESTIGATION OF THE PHASE CONSTITUTION OF AL2TITA SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID AL RP BOETTINGER, WJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD SEP PY 1991 VL 25 IS 9 BP 1993 EP 1998 DI 10.1016/0956-716X(91)90262-Y PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GE197 UT WOS:A1991GE19700001 ER PT J AU BOUGHTON, DA COLLETTE, BB MCCUNE, AR AF BOUGHTON, DA COLLETTE, BB MCCUNE, AR TI HETEROCHRONY IN JAW MORPHOLOGY OF NEEDLEFISHES (TELEOSTEI, BELONIDAE) SO SYSTEMATIC ZOOLOGY LA English DT Article DE HETEROCHRONY; ONTOGENIC TRAJECTORY; BELONIDAE; JAW MORPHOLOGY; CHARACTER CODING; M-CODING ID PHYLOGENY; EVOLUTION; ONTOGENY; GARFISH; FISHES; SIZE AB The jaw morphology of needlefishes (Beloniformes: Belonidae) passes through distinctive ontogenetic stages. When hatched, larvae have short jaws of equal length. The lower jaw first elongates to produce a "halfbeak" form, then the upper jaw elongates to produce the adult "needlenose" morphology. Onset and duration of the halfbeak stage vary among belonid species. We tested the hypothesis that heterochronic evolution produced this diversity in jaw morphology. First, a cladogram was developed for 27 belonid species. Ontogenetic trajectories for upper and lower jaw elongation were determined for 18 of these species. For upper and lower jaw elongation, trajectories of these 18 species were statistically compared to determine character transitions, which were then mapped onto the cladogram. The results showed that the growth trajectories of upper and lower jaws changed independently of each other, and that neoteny and acceleration occurred repeatedly during belonid evolution. Evidence suggests postdisplacement and predisplacement were also important mechanisms. The resulting morphological diversity may be interpreted as adaptations to food availability, because jaw morphology (halfbeak vs. needlenose) seems to be correlated with feeding modes (planktivory vs. piscivory). C1 CORNELL UNIV, DIV BIOL SCI, ECOL & SYSTEMAT SECT, ITHACA, NY 14853 USA. NATL MUSEUM NAT HIST, SYSTEMAT LAB, NATL MARINE FISHERIES SERV, WASHINGTON, DC 20560 USA. NR 38 TC 27 Z9 27 U1 2 U2 8 PU SOC SYSTEMATIC ZOOLOGY PI WASHINGTON PA NATL MUSEUM NATURAL HISTORY 10TH AND CONSTITUTION NW, WASHINGTON, DC 20560 USA SN 0039-7989 J9 SYST ZOOL PD SEP PY 1991 VL 40 IS 3 BP 329 EP 354 DI 10.2307/2992326 PG 26 WC Zoology SC Zoology GA GH604 UT WOS:A1991GH60400006 ER PT J AU INDELICATO, P MOHR, PJ AF INDELICATO, P MOHR, PJ TI QUANTUM ELECTRODYNAMIC EFFECTS IN ATOMIC-STRUCTURE SO THEORETICA CHIMICA ACTA LA English DT Article DE HIGH-Z ATOMS; QED EFFECTS; LITHIUM-LIKE URANIUM; SELF ENERGY; LAMB SHIFT ID RADIATIVE-CORRECTIONS; SELF-ENERGY; SHIFT AB In high-Z atoms, quantum electrodynamic (QED) corrections are an important component in the theoretical prediction of atomic energy levels. The main QED effects in electronic atoms are the one-electron self-energy and vacuum-polarization corrections which are well known. At the next level of precision, estimates of the effect of electron interactions on the self energy and higher-order effects in two exchanged photon corrections are necessary. These corrections can be evaluated within the framework of QED in the bound interaction picture. For high-Z few-electron atoms, this approach provides a rapidly converging series in 1/Z for the corrections, which is the generalization of the well-known relativistic 1/Z expansion methods. This paper describes recent work on the effect of electron interactions on the self energy. The QED effects are particularly important for the theory for lithiumlike uranium where an accurate measurement of the Lamb shift has been made, as well as for numerous other cases where systematic differences appear between theory that does not include these QED effects and experiment. C1 UNIV PARIS 06,LPAN,F-75252 PARIS 05,FRANCE. RP INDELICATO, P (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 20 TC 64 Z9 64 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0040-5744 J9 THEOR CHIM ACTA JI Theor. Chim. Acta PD SEP PY 1991 VL 80 IS 2-3 BP 207 EP 214 DI 10.1007/BF01119620 PG 8 WC Chemistry, Physical SC Chemistry GA GG816 UT WOS:A1991GG81600007 ER PT J AU REAP, RM AF REAP, RM TI CLIMATOLOGICAL CHARACTERISTICS AND OBJECTIVE PREDICTION OF THUNDERSTORMS OVER ALASKA SO WEATHER AND FORECASTING LA English DT Article AB Archived lightning data from the Bureau of Land Management automated network of direction-finding stations in Alaska were examined to determine the seasonal, diurnal, and spatial distributions of cloud-to-ground lightning, including the effects of the underlying topography on the timing, location, and magnitude of the lightning activity. The interior of Alaska was found to exhibit a continental type climate with a pronounced afternoon maximum in lightning activity and no significant nocturnal activity. Over 90% of the strikes were found to occur during June and July, the time of maximum solar insolation. A relatively high incidence of positive flashes was found during all phases of thunderstorm occurrence. High flash accumulations over mountainous regions clearly revealed the affinity of lightning activity for elevated terrain. Maximum activity was found to occur earliest in the higher elevations, moving to lower elevations later in the day. Linear screening regression analysis and the Model Output Statistics approach were used to statistically relate lightning data to Nested Grid Model forecast fields. Operational equations were derived to provide objective thunderstorm probabilities for use as guidance by forecasters in estimating the potential hazard of wildfire initiation in Alaska. The primary prerequisite for the formation of thunderstorms over Alaska was found to be large-scale static instability followed by secondary contributions from local convergence in the wind and moisture fields. Low-level moisture convergence was also found to be very important to the production of high flash accumulations on any given day. RP REAP, RM (reprint author), NOAA,NATL WEATHER SERV,TECHN DEV LAB,OFF SYST DEV,SILVER SPRING,MD 20910, USA. NR 0 TC 24 Z9 28 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 309 EP 319 DI 10.1175/1520-0434(1991)006<0309:CCAOPO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200001 ER PT J AU MCGINLEY, JA ALBERS, SC STAMUS, PA AF MCGINLEY, JA ALBERS, SC STAMUS, PA TI VALIDATION OF A COMPOSITE CONVECTIVE INDEX AS DEFINED BY A REAL-TIME LOCAL ANALYSIS SYSTEM SO WEATHER AND FORECASTING LA English DT Article AB Advances in remote sensing from earth- and spaceborne systems, expanded in situ observation networks, and increased low-cost computer capability will allow an unprecedented view of mesoscale weather systems from the local weather office. However, the volume of data from these new instruments, the nonconventional quantities measured, and the need for a frequent operational cycle require development of systems to translate this information into products aimed specifically at aiding the forecaster in 0- to 6-h prediction. In northeast Colorado an observing network now exists that is similar to those that a local weather office may see within 5-7 years. With GOES and TIROS satellites, Doppler radar, wind profilers, and surface mesonet stations, a unique opportunity exists to explore the use of such data in nowcasting weather phenomena. The scheme, called LAPS (the Local Analysis and Prediction System), objectively analyzes data on a high-resolution, three-dimensional grid. The analyzed fields are used to generate mesoscale forecast products aimed at specific local forecast problems. An experiment conducted in the summer of 1989 sought to test the use of a preconvective index on the difficult problem of convective rain forecasting. The index was configured from surface-based lifted index and kinematically diagnosed vertical motion. The index involved a number of LAPS-derived meteorological fields and the results of the test measured in some sense the quality of those fields. Using radar reflectivity to verify the occurrence or nonoccurrence of convective precipitation, forecasts were issued for three time periods on each of 62 exercise days. The results indicated that the index was significantly better than persistence over a range of echo intensities. Skill scores computed from contingency tables indicated that the index had substantial skill in forecasting light convective precipitation with 1- to 3-h lead time. Less skill was shown for heavier convective showers. The skill of the index did not depend strongly on the density of surface data, but was negatively influenced by mountainous terrain. RP MCGINLEY, JA (reprint author), NOAA,ENVIRONM RES LABS,FORECAST SYST LAB,PROGRAM REG OBSERVING & FORECASTING SERV,BOULDER,CO 80303, USA. RI Albers, Steven/E-7416-2015 NR 0 TC 42 Z9 53 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 337 EP 356 DI 10.1175/1520-0434(1991)006<0337:VOACCI>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200003 ER PT J AU POWELL, MD DODGE, PP BLACK, ML AF POWELL, MD DODGE, PP BLACK, ML TI THE LANDFALL OF HURRICANE HUGO IN THE CAROLINAS - SURFACE WIND DISTRIBUTION SO WEATHER AND FORECASTING LA English DT Article AB Hurricane Hugo struck Charleston, South Carolina, on 22 September 1989 as the most intense hurricane to affect the United States since Camille in 1969. The northeastern eyewall, which contained the maximum winds measured by reconnaissance aircraft shortly before landfall, moved inland over a relatively unpopulated area and there were few fatalities. However, no observations were available to document the surface wind distribution in this part of the storm as it continued inland. To improve specification of surface winds in Hugo, empirically adjusted aircraft winds were combined with coastal, offshore, and inland surface observations and were input to the Ooyama objective analysis algorithm. The wind analysis at landfall was then compared with subsequent analyses at 3 and 6 h after landfall. Reconstruction of the surface wind field at landfall suggests that the maximum (approximately 13 min mean) surface wind at the coast was 50 m s-1 in the Bulls Bay region, approximately 40 km northeast of Charleston. Surface roughness over land caused wind speeds to drop off rapidly just inland of the coast to only 50% of values measured by reconnaissance aircraft at the same location relative to the strom over water. Despite relatively rapid increases in the central sea-level pressure and decreases in the mean circulation as Hugo progressed inland, hurricane-force wind gusts extended Hugo's damage pattern well past Charlotte, North Carolina, approximately 330 km inland. Accurate determination of surface wind distribution in land-falling hurricanes is dependent upon the spatial density and quality of surface wind measurements and techniques to adjust reconnaissance flight-level winds to the surface. Improvements should allow forecasters to prepare more-accurate warnings and advisories and allow more-thorough documentation of poststorm effects. Empirical adjustments to reconnaissance aircraft measurements may replace surface data voids if the vertical profile of the horizontal wind is known. Expanded use of the airborne stepped-frequency microwave radiometer for remote sensing of ocean surface winds could fill data voids without relying upon empirical methods or models. A larger network of offshore, coastal, and inland surface platforms at standard (10-m) elevations with improved sampling strategies is envisioned for better resolution of hurricane wind fields. A rapid-response automatic station network, deployed at prearranged coastal locations by local universities with meteorology and/or wind engineering programs, could further supplement the fixed platform network and avoid the logistical problems posed by sending outside teams into threatened areas. RP POWELL, MD (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,DIV ENZYME RES,4310 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Powell, Mark/I-4963-2013; Black, Michael/C-3250-2014; dodge, peter/A-9808-2017 OI Powell, Mark/0000-0002-4890-8945; Black, Michael/0000-0001-9528-2888; NR 0 TC 63 Z9 65 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 379 EP 399 DI 10.1175/1520-0434(1991)006<0379:TLOHHI>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200005 ER PT J AU MURPHY, AH AF MURPHY, AH TI ON SUMMARY MEASURES OF SKILL IN RARE EVENT FORECASTING BASED ON CONTINGENCY-TABLES - COMMENT SO WEATHER AND FORECASTING LA English DT Note RP MURPHY, AH (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,WWB,CTR CLIMATE ANAL,UCAR VISITING SCI PROGRAM,WASHINGTON,DC 20233, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 400 EP 402 DI 10.1175/1520-0434(1991)006<0400:COSMOS>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200006 ER PT J AU DOSWELL, CA DAVIESJONES, R KELLER, DL AF DOSWELL, CA DAVIESJONES, R KELLER, DL TI ON SUMMARY MEASURES OF SKILL IN RARE EVENT FORECASTING BASED ON CONTINGENCY-TABLES - REPLY SO WEATHER AND FORECASTING LA English DT Note RP DOSWELL, CA (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 403 EP 403 DI 10.1175/1520-0434(1991)006<0403:R>2.0.CO;2 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200007 ER PT J AU WEAVER, JF DOESKEN, NJ AF WEAVER, JF DOESKEN, NJ TI HIGH-PLAINS SEVERE WEATHER - 10 YEARS AFTER SO WEATHER AND FORECASTING LA English DT Article AB More than a decade ago, a study was published that identified a short list of precursor conditions for severe thunderstorms on the High Plains of the United States. The present study utilizes data from the summer months of ten convective seasons to estimate how well the criteria fare as a method of forecasting severe weather days in that region. Results indicate that the technique produces a relatively high success rate in terms of detecting severe weather days for most years studied. False alarms are a bit high in an absolute sense (36% overall), but fall well within acceptable limits in the real world, where the philosophy of "better to overwarn, than underforecast" prevails. RP WEAVER, JF (reprint author), COLORADO STATE UNIV,NOAA,NESDIS,RAMM BRANCH,FT COLLINS,CO 80523, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1991 VL 6 IS 3 BP 411 EP 414 DI 10.1175/1520-0434(1991)006<0411:HPSWYA>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG192 UT WOS:A1991GG19200009 ER PT J AU BERK, NF RUSH, JJ UDOVIC, TJ ANDERSON, IS AF BERK, NF RUSH, JJ UDOVIC, TJ ANDERSON, IS TI ANOMALOUS HYDROGEN DYNAMICS IN RARE-EARTH-METALS SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA ID LIGHT INTERSTITIALS; NEUTRON-SCATTERING; DIFFUSION; YTTRIUM; SYSTEM; RELAXATION; SCANDIUM; MOTION AB Neutron scattering studies of the dynamics of the hydrogen isotopes in h.c.p. rare earth metals have demonstrated a rich variety of phenomena of basic importance to the understanding of hydrogen in metals. In this paper we review our recent measurements of hydrogen vibrations in yttrium using inelastic neutron scattering and our very recent investigations of hydrogen local hopping in scandium and yttrium using quasielastic neutron scattering. Using simple models we attempt to provide a straight-forward but fairly comprehensive picture of the way extended hydrogen short range order, observed directly in diffuse neutron scattering experiments, influences these measurements. We show, for example, how the vibrational peak splitting measured in alpha-YH(x) can be interpreted in terms of temperature- and concentration-dependent effects of the chain-like pairing order. We also describe in detail our recent demonstration of very fast local T-T hopping in alpha-ScH(x) and in alpha-YH(x) and relate the observations to the identification of thermodynamically distinct labile (uninvolved in extended order) and non-labile (involved in extended order) hydrogens. In particular, we measure a pronounced T-T hopping rate minimum at 100 K, which we ascribe to the labile protons and show how the low temperature hopping rate is described by the Kondo model of quantum hopping due to the non-adiabatic effects of weak interaction between the protons and the conduction electrons of the host metal. C1 PAUL SCHERRER INST,CH-5234 VILLIGEN,SWITZERLAND. RP BERK, NF (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 22 TC 31 Z9 31 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 496 EP 508 DI 10.1016/S0022-5088(06)80287-0 PN B PG 13 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900005 ER PT J AU KIRCHHEIM, R KIENINGER, W HUANG, XY FILIPEK, SM RUSH, J UDOVIC, T AF KIRCHHEIM, R KIENINGER, W HUANG, XY FILIPEK, SM RUSH, J UDOVIC, T TI HYDROGEN IN AMORPHOUS NI-ZR AND NI-TI ALLOYS SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article AB Various results on properties (solubility, diffusivity and local modes) of hydrogen in amorphous Ni1-xZrx (x = 0.35, 0.5, 0.65) and Ni0.35 Ti0.65 will be presented as a function of hydrogen concentration. The results are interpreted in the framework of the site energy distribution model. Within experimental error the measured distribution of site energies can be described by superimposing gaussian distributions for the five possible tetrahedral sites (Zr4, Zr3Ni, Zr2 Ni2 etc.) and assuming a random distribution of the metal atoms with a maximum number of interstices varying between 1.2 and 1.7 per metal atom. The local modes of hydrogen vibration are not affected very much by filling different tetrahedral sites with hydrogen, whereas hydrogen diffusivity changes over two or three orders of magnitude. The concentration dependence of the diffusion coefficient is in semiquantitative agreement with the model of constant saddle point energies and discrepancies may arise from correlations between site and saddle point energies or from diffusion via sublattices formed by the different types of tetrahedra. C1 POLISH ACAD SCI,INST PHYS CHEM,WARSAW 42,POLAND. NBS,WASHINGTON,DC 20234. RP KIRCHHEIM, R (reprint author), MAX PLANCK INST MET RES,SEESTR 92,W-7000 STUTTGART 10,GERMANY. NR 12 TC 26 Z9 26 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 30 PY 1991 VL 172 BP 880 EP 889 PN B PG 10 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GH229 UT WOS:A1991GH22900051 ER PT J AU NAGORKA, MS LEVI, CG LUCAS, GE RIDDER, SD AF NAGORKA, MS LEVI, CG LUCAS, GE RIDDER, SD TI THE POTENTIAL OF RAPID SOLIDIFICATION IN OXIDE-DISPERSION-STRENGTHENED COPPER ALLOY DEVELOPMENT SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID PARTICLE-DISLOCATION INTERACTION; HARD PARTICLES; CLIMB; KINETICS AB The feasibility of producing yttria (Y2O3)-dispersion-strengthened copper by internal oxidation of rapidly solidified Cu-Y alloys was investigated. Alloys containing about 1 at.% Y were prepared via conventional solidification, supersonic gas atomization and splat-quenching techniques. The spacing of the Cu-Y intermetallic phase was found to depend on the solidification velocity as lambda-V(n) = constant, where n increased from about 0.4 to about 0.6 as the solidification rate increases. Y2O3 particles were produced by the oxidation of the yttrium present in the intermetallic phase, which was tentatively identified as Cu7Y. Specimens internally oxidized at 873 or 1123 K revealed that a relatively uniform distribution of fine Y2O3 dispersoids was produced in the splat-quenched material. On the contrary, the Y2O3 particles in the conventionally cast and gas-atomized powders were largely confined to the prior interdendritic segregate, presumably because of insufficient refinement in the scale of the cast microstructure. Selected-area diffraction pattern analysis of Y2O3 particles in the splats indicated an {100}Y2O3 parallel-to {100}Cu and <100>Y2O3 parallel-to <100>Cu orientation relationship with the copper matrix. C1 NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. RP NAGORKA, MS (reprint author), UNIV CALIF SANTA BARBARA,DEPT MAT,SANTA BARBARA,CA 93106, USA. NR 22 TC 18 Z9 22 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 30 PY 1991 VL 142 IS 2 BP 277 EP 289 DI 10.1016/0921-5093(91)90666-B PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA GD452 UT WOS:A1991GD45200015 ER PT J AU ONO, RH BEALL, JA CROMAR, MW HARVEY, TE JOHANSSON, ME REINTSEMA, CD RUDMAN, DA AF ONO, RH BEALL, JA CROMAR, MW HARVEY, TE JOHANSSON, ME REINTSEMA, CD RUDMAN, DA TI HIGH-TC SUPERCONDUCTOR-NORMAL METAL-SUPERCONDUCTOR JOSEPHSON MICROBRIDGES WITH HIGH-RESISTANCE NORMAL METAL LINKS SO APPLIED PHYSICS LETTERS LA English DT Article AB We have developed an in situ process for fabricating high transition temperature superconductor-normal metal-superconductor microbridges using a step edge to define the normal metal length. Critical current-normal resistance products over 1 mV have been measured at low temperature in devices with high-resistivity Ag-Au alloy bridges. Results on samples with Ag bridges are compared with the alloy data as an initial test of recent theories of SNS Josephson junctions. Josephson effects have been demonstrated in these devices at temperatures higher than 80 K. Clearly defined rf steps have been observed, with power dependence qualitatively similar to theoretical predictions. RP ONO, RH (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 13 TC 102 Z9 102 U1 0 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 AUG 26 PY 1991 VL 59 IS 9 BP 1126 EP 1128 DI 10.1063/1.106365 PG 3 WC Physics, Applied SC Physics GA GC329 UT WOS:A1991GC32900042 ER PT J AU HUBBELL, JH AF HUBBELL, JH TI FASTER THAN A SPEEDING PHOTON - A CITATION-CLASSIC COMMENTARY ON VISIBLE-LIGHT FROM CLEAR LIQUIDS UNDER THE ACTION OF GAMMA-RADIATION BY CHERENKOV,P.A. SO CURRENT CONTENTS/ENGINEERING TECHNOLOGY & APPLIED SCIENCES LA English DT Article RP HUBBELL, JH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU INST SCI INFORM INC PI PHILADELPHIA PA 3501 MARKET ST, PHILADELPHIA, PA 19104 SN 0011-3395 J9 CC/ENG TECH APPL SCI PD AUG 26 PY 1991 IS 34 BP 10 EP 10 PG 1 WC Multidisciplinary Sciences; Social Sciences, Interdisciplinary SC Science & Technology - Other Topics; Social Sciences - Other Topics GA GA092 UT WOS:A1991GA09200001 ER PT J AU HUBBELL, JH AF HUBBELL, JH TI FASTER THAN A SPEEDING PHOTON - A CITATION-CLASSIC COMMENTARY ON VISIBLE-LIGHT FROM CLEAR LIQUIDS UNDER THE ACTION OF GAMMA-RADIATION BY CHERENKOV,P.A. SO CURRENT CONTENTS/PHYSICAL CHEMICAL & EARTH SCIENCES LA English DT Article RP HUBBELL, JH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU INST SCI INFORM INC PI PHILADELPHIA PA 3501 MARKET ST, PHILADELPHIA, PA 19104 SN 0163-2574 J9 CC/PHYS CHEM EARTH PD AUG 26 PY 1991 IS 34 BP 10 EP 10 PG 1 WC Multidisciplinary Sciences; Social Sciences, Interdisciplinary SC Science & Technology - Other Topics; Social Sciences - Other Topics GA GA093 UT WOS:A1991GA09300001 ER PT J AU REIMANN, CW AF REIMANN, CW TI RATING THE BALDRIGE AWARD SO FORTUNE LA English DT Letter RP REIMANN, CW (reprint author), US DEPT COMMERCE,NATL INST STANDARDS & TECHNOL,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TIME INC PI NEW YORK PA TIME & LIFE BUILDING ROCKEFELLER CENTER, NEW YORK, NY 10020-1393 SN 0015-8259 J9 FORTUNE JI Fortune PD AUG 26 PY 1991 VL 124 IS 5 BP 34 EP 34 PG 1 WC Business SC Business & Economics GA GA041 UT WOS:A1991GA04100006 ER PT J AU SOUTHWORTH, SH LINDLE, DW MAYER, R COWAN, PL AF SOUTHWORTH, SH LINDLE, DW MAYER, R COWAN, PL TI ANISOTROPY OF POLARIZED X-RAY-EMISSION FROM MOLECULES SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; PHOTO-IONIZATION; ALIGNMENT; FLUORESCENCE; PERFORMANCE AB Strongly anisotropic, polarized Cl K-V x-ray emission from gas-phase CF3Cl has been observed following resonant excitation with a linearly polarized x-ray beam. Distinctively different angular distributions are observed for x-ray emission involving molecular orbitals of different symmetries. A classical model of the x-ray absorption-emission process accurately describes the observed radiation patterns. RP SOUTHWORTH, SH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 21 TC 40 Z9 40 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 26 PY 1991 VL 67 IS 9 BP 1098 EP 1101 DI 10.1103/PhysRevLett.67.1098 PG 4 WC Physics, Multidisciplinary SC Physics GA GC603 UT WOS:A1991GC60300011 ER PT J AU BAUER, BJ BRIBER, RM DICKENS, B AF BAUER, BJ BRIBER, RM DICKENS, B TI STUDIES OF GRAFTED INTERPENETRATING POLYMER NETWORKS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 3 EP PMSE PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101271 ER PT J AU STEIN, SE AF STEIN, SE TI THE NIST STRUCTURES AND PROPERTIES DATABASE AND ESTIMATION SYSTEM SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 14 EP COMP PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08001628 ER PT J AU WU, CYC KOCH, WF EWT, PA HOLLAND, LA AF WU, CYC KOCH, WF EWT, PA HOLLAND, LA TI THE 1ST-DISSOCIATION CONSTANT OF AMINO-ACIDS BY THE CONDUCTIVITY METHOD .1. MOPSO-HC1 AT 25 SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 33 EP BIOL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000790 ER PT J AU WU, YC FENG, DM KOCH, WF AF WU, YC FENG, DM KOCH, WF TI INVESTIGATION OF THE INTERACTION OF SODIUM-CHLORIDE AND 2 AMINO SULFONIC-ACIDS, HEPES AND MOPSO, BY EMF-MEASUREMENTS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 34 EP BIOL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000791 ER PT J AU BASCH, H KRAUSS, M AF BASCH, H KRAUSS, M TI IS THE VANADATE ANION AN ANALOG OF THE PHOSPHORANE TRANSITION-STATE IN RNASE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 BAR ILAN UNIV,DEPT CHEM,RAMAT GAN,ISRAEL. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 61 EP BIOL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000818 ER PT J AU KRAUSS, M GARMER, D AF KRAUSS, M GARMER, D TI ACTIVE-SITE IONICITY AND THE MECHANISM OF CARBONIC-ANHYDRASE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 63 EP BIOL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000820 ER PT J AU TSANG, W WALKER, JA AF TSANG, W WALKER, JA TI THE THERMAL-DECOMPOSITION OF 1,7-OCTADIYNE AS A SOURCE OF PROPARGYL RADICALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 67 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08001850 ER PT J AU THAYER, JS BRINCKMAN, FE AF THAYER, JS BRINCKMAN, FE TI REACTIONS OF AQUEOUS ALKYL-HALIDES WITH BINARY METAL-COMPOUNDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV CINCINNATI,DEPT CHEM,CINCINNATI,OH 45221. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 80 EP INOR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08002133 ER PT J AU FOSTER, MD SIKKA, M SINGH, N BATES, FS SATIJA, S MAJKRZAK, CF AF FOSTER, MD SIKKA, M SINGH, N BATES, FS SATIJA, S MAJKRZAK, CF TI FINITE THICKNESS EFFECTS IN THE THERMODYNAMICS OF DIBLOCK COPOLYMER THIN-FILMS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,RRD,GAITHERSBURG,MD 20899. UNIV AKRON,DEPT POLYMER SCI,AKRON,OH 44325. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 90 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100992 ER PT J AU SIMIC, MG AF SIMIC, MG TI MECHANISMS OF LIPID OXIDATIVE PROCESSES IN FOODS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 93 EP AGFD PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000095 ER PT J AU SANDER, LC WISE, SA AF SANDER, LC WISE, SA TI MOLECULAR SHAPE-DISCRIMINATION IN LIQUID-CHROMATOGRAPHY FOR THE SEPARATION OF AROMATIC-COMPOUNDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 98 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG080 UT WOS:A1991HG08000467 ER PT J AU NAKATANI, AI WALDOW, DA HAN, CC AF NAKATANI, AI WALDOW, DA HAN, CC TI PHASE-BEHAVIOR OF A POLYMER-SOLUTION STUDIED BY LIGHT-SCATTERING DURING STEADY SHEAR AND FOLLOWING CESSATION OF SHEAR SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 107 EP PMSE PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101375 ER PT J AU NAKATANI, AI WALDOW, DA HAN, CC AF NAKATANI, AI WALDOW, DA HAN, CC TI PHASE-BEHAVIOR OF A POLYMER BLEND SOLUTION DURING STEADY SHEAR AND CESSATION OF SHEAR STUDIED BY LIGHT-SCATTERING SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 134 EP PMSE PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101402 ER PT J AU ANTONUCCI, JM STANSBURY, JW REED, BB AF ANTONUCCI, JM STANSBURY, JW REED, BB TI RADICAL REACTIVITY OF CYCLIC ACETALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 156 EP ORGN PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100249 ER PT J AU REED, BB STANSBURY, JW ANTONUCCI, JM AF REED, BB STANSBURY, JW ANTONUCCI, JM TI RADICAL RING-OPENING CHARACTERISTICS OF CYCLIC VINYL MONOMERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 157 EP ORGN PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100250 ER PT J AU CHASE, MW KORENDYKE, NP AF CHASE, MW KORENDYKE, NP TI COMPUTERIZATION OF MATERIAL AND CHEMICAL-DATA SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,STAND REFERENCE DATA,GAITHERSBURG,MD 20899. MAXWELL ONLINE INC,DATABASE DEV,MCLEAN,VA 22102. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 160 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100695 ER PT J AU JACKSON, CL MCKENNA, GB AF JACKSON, CL MCKENNA, GB TI A REEXAMINATION OF THE FREEZING AND MELTING OF SOLVENT IN THERMOREVERSIBLE POLYMER GELS AND RELATED SYSTEMS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 170 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101072 ER PT J AU WU, WL KUROKAWA, H SHIBAYAMA, M NOMURA, S COYNE, LD AF WU, WL KUROKAWA, H SHIBAYAMA, M NOMURA, S COYNE, LD TI PHASE-BEHAVIOR OF AQUEOUS POLY(VINYL-ALCOHOL) SOLUTION - A SMALL-ANGLE NEUTRON-SCATTERING STUDY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 KYOTO INST TECHNOL,SAKYO KU,KYOTO 606,JAPAN. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. US FDA,ROCKVILLE,MD 20852. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 171 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101073 ER PT J AU STROSCIO, JA AF STROSCIO, JA TI SCANNING TUNNELING MICROSCOPY OF ALKALI-METALS ON III-V(110) SURFACES - FROM 1-D AND 2-D INSULATORS TO 3-D METALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 183 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100718 ER PT J AU MCKENNA, GB KERN, F CANDAU, SJ WITTMANN, JC THIERRY, A AF MCKENNA, GB KERN, F CANDAU, SJ WITTMANN, JC THIERRY, A TI THERMOREVERSIBLE GELS FROM DIBENZYLIDENE SORBITOL AND ORGANIC-SOLVENTS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 INST CHARLES SADRON,STRASBOURG,FRANCE. UNIV STRASBOURG 1,CNRS,UNITE RECH 851,ULTRASONS & DYNAM FLUIDES COMPLEXES LAB,F-67070 STRASBOURG,FRANCE. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 201 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101103 ER PT J AU BASCH, H KRAUSS, M STEVENS, WJ AF BASCH, H KRAUSS, M STEVENS, WJ TI ANION BINDING TO POLAR-MOLECULES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. BAR ILAN UNIV,DEPT CHEM,RAMAT GAN,ISRAEL. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 224 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100757 ER PT J AU VERDIER, PH DOUGLAS, JF MCKENNA, GB AF VERDIER, PH DOUGLAS, JF MCKENNA, GB TI RINGS VERSUS STRINGS - OFF-LATTICE, BEAD-STICK COMPUTER-SIMULATIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV TECHNOL,GAITHERSBURG,MD 20899. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 235 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101134 ER PT J AU GARMER, DR KRAUSS, M AF GARMER, DR KRAUSS, M TI COBALT SPECTROSCOPY AT THE ACTIVE-SITE OF CARBONIC-ANHYDRASE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 256 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100789 ER PT J AU DOUGLAS, JF ROOVERS, J FREED, KF AF DOUGLAS, JF ROOVERS, J FREED, KF TI CHARACTERIZATION OF BRANCHING ARCHITECTURE THROUGH UNIVERSAL RATIOS OF POLYMER-SOLUTION PROPERTIES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NBS,DIV POLYMER,GAITHERSBURG,MD 20899. NATL RES COUNCIL CANADA,DIV CHEM,OTTAWA K1A 0R6,ONTARIO,CANADA. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 293 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101192 ER PT J AU SANTORE, MM MCKENNA, GB HAN, CC AF SANTORE, MM MCKENNA, GB HAN, CC TI PHASE-DIAGRAMS AND SPINODAL DECOMPOSITION IN LINEAR AND CYCLIC POLYSTYRENE POLY[VINYL METHYL-ETHER] BLENDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. LEHIGH UNIV,DEPT CHEM ENGN,BETHLEHEM,PA 18015. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 295 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08101194 ER PT J AU DAGATA, JA TSENG, W BENNETT, J SCHNEIR, J HARARY, HH AF DAGATA, JA TSENG, W BENNETT, J SCHNEIR, J HARARY, HH TI PREPARATION OF PASSIVATED III-V SURFACES FOR STM NANOLITHOGRAPHY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1991 VL 202 BP 363 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA HG081 UT WOS:A1991HG08100896 ER PT J AU PESKIN, AP KO, MK PELLEGRINO, JJ AF PESKIN, AP KO, MK PELLEGRINO, JJ TI 3 LAYER MEMBRANE MODEL FOR CHARACTERIZING ULTRAFILTRATION MEMBRANES SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE ULTRAFILTRATION; THEORY; MASS-TRANSFER ID OSMOTIC-PRESSURE; MASS-TRANSFER; CROSS-FLOW AB To characterize ultrafiltration membranes, it is important to understand their intrinsic, macromolecular-rejection properties. Defining these properties in terms of a membrane's permselectivity parameters requires an understanding of the mass transfer of the solute at the membrane interface. The solute concentration is difficult to measure experimentally, and has been previously estimated using various forms of a mass transfer coefficient. In this paper, we present an analytical, steady-state model for predicting ultrafiltration solute concentrations at the membrane interface from experimentally measured parameters and known solute physical properties - without the use of a mass transfer correlation. We then extend the model by looking at mass transfer through the membrane itself, in order to predict membrane permselectivity parameters. RP PESKIN, AP (reprint author), NATL INST STAND & TECHNOL,DIV CHEM ENGN SCI,832-01,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD AUG 23 PY 1991 VL 60 IS 2-3 BP 195 EP 206 PG 12 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA GE763 UT WOS:A1991GE76300007 ER PT J AU CESS, RD POTTER, GL ZHANG, MH BLANCHET, JP CHALITA, S COLMAN, R DAZLICH, DA DELGENIO, AD DYMNIKOV, V GALIN, V JERRETT, D KEUP, E LACIS, AA LETREUT, H LIANG, XZ MAHFOUF, JF MCAVANEY, BJ MELESHKO, VP MITCHELL, JFB MORCRETTE, JJ NORRIS, PM RANDALL, DA RIKUS, L ROECKNER, E ROYER, JF SCHLESE, U SHEININ, DA SLINGO, JM SOKOLOV, AP TAYLOR, KE WASHINGTON, WM WETHERALD, RT YAGAI, I AF CESS, RD POTTER, GL ZHANG, MH BLANCHET, JP CHALITA, S COLMAN, R DAZLICH, DA DELGENIO, AD DYMNIKOV, V GALIN, V JERRETT, D KEUP, E LACIS, AA LETREUT, H LIANG, XZ MAHFOUF, JF MCAVANEY, BJ MELESHKO, VP MITCHELL, JFB MORCRETTE, JJ NORRIS, PM RANDALL, DA RIKUS, L ROECKNER, E ROYER, JF SCHLESE, U SHEININ, DA SLINGO, JM SOKOLOV, AP TAYLOR, KE WASHINGTON, WM WETHERALD, RT YAGAI, I TI INTERPRETATION OF SNOW-CLIMATE FEEDBACK AS PRODUCED BY 17 GENERAL-CIRCULATION MODELS SO SCIENCE LA English DT Article AB Snow feedback is expected to amplify global warming caused by increasing concentrations of atmospheric greenhouse gases. The conventional explanation is that a warmer Earth will have less snow cover, resulting in a darker planet that absorbs more solar radiation. An intercomparison of 17 general circulation models, for which perturbations of sea surface temperature were used as a surrogate climate change, suggests that this explanation is overly simplistic. The results instead indicate that additional amplification or moderation may be caused both by cloud interactions and longwave radiation. One measure of this net effect of snow feedback was found to differ markedly among the 17 climate models, ranging from weak negative feedback in some models to strong positive feedback in others. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. CANADIAN CLIMATE CTR,TORONTO M3H 574,ONTARIO,CANADA. LAB METEOROL DYNAM,F-75231 PARIS 05,FRANCE. BUR METEOROL RES CTR,MELBOURNE,VIC 3001,AUSTRALIA. COLORADO STATE UNIV,FT COLLINS,CO 80523. NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. ACAD SCI USSR,DEPT NUMERICAL MATH,MOSCOW 119034,USSR. HADLEY CTR CLIMATE PREDICT & RES,METEOROL OFF,BRACKNELL RG12 2SZ,BERKS,ENGLAND. MAX PLANCK INST METEOROL,W-2000 HAMBURG 13,GERMANY. SUNY ALBANY,ALBANY,NY 12222. CTR NATL RECH MET,DIRECT METEOROL NAT,F-31057 TOULOUSE,FRANCE. LENINGRAD MAIN GEOPHYS OBSERV,LENINGRAD 194018,USSR. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS,READING RG2 92X,BERKS,ENGLAND. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. UNIV READING,READING RG6 2AU,ENGLAND. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08544. METEOROL RES INST,TSUKUBA,IBARAKI 305,JAPAN. RP CESS, RD (reprint author), SUNY STONY BROOK,INST TERR & PLANETARY ATMOSPHERES,STONY BROOK,NY 11794, USA. RI Taylor, Karl/F-7290-2011; Del Genio, Anthony/D-4663-2012; Lacis, Andrew/D-4658-2012; Randall, David/E-6113-2011; Norris, Peter/H-2008-2012 OI Taylor, Karl/0000-0002-6491-2135; Del Genio, Anthony/0000-0001-7450-1359; Randall, David/0000-0001-6935-4112; Norris, Peter/0000-0001-6807-9884 NR 7 TC 121 Z9 126 U1 4 U2 19 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 23 PY 1991 VL 253 IS 5022 BP 888 EP 892 DI 10.1126/science.253.5022.888 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GC152 UT WOS:A1991GC15200040 PM 17751825 ER PT J AU TURNIPSEED, AA BIRKS, JW AF TURNIPSEED, AA BIRKS, JW TI KINETICS OF THE REACTION OF MOLECULAR FLUORINE WITH DIMETHYL SULFIDE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CHEMI-LUMINESCENT REACTIONS; SPECTRA; ATOMS; BEAM; CHEMILUMINESCENCE; SULFUR; F2 AB The reaction of molecular fluorine with dimethyl sulfide (DMS) was investigated by using the flow tube technique with mass spectrometry for detection of reactants and products and a diode array spectrometer for collection of chemiluminescence spectra. The reaction was found to proceed with an extraordinarily large rate coefficient of k4 = (1.6 +/- 0.5) x 10(-11) cm3 molecule-1 s-1 at 298 K. The observation of such a fast rate for the reaction of two closed-shell species is unexpected. It is proposed that the reaction proceeds through a charge-transfer complex with subsequent elimination of H and F atoms or of molecular HF. Once initiation of the reaction occurs, a radical chain reaction leads to chemiluminescent products. A reaction intermediate, thought to be H2C = SFCH3, occurs at m/e = 80 when DMS is in excess over F2. Under these conditions, the principal emitting species is H2C = S. When F2 is the excess reactant, the intermediate at m/e = 80 is destroyed and the principal emitting species is HCF. A charge-transfer mechanism for initiation of F2 reactions qualitatively explains the relative responses of classes of compounds in the fluorine-induced chemiluminescence detector. The F2 + H2S reaction was also studied, and an upper limit of k7 less-than-or-equal-to 6.4 x 10(-16) cm3 molecule-1 s-1 was measured. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,CAMPUS BOX 216,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 32 TC 20 Z9 20 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 22 PY 1991 VL 95 IS 17 BP 6569 EP 6574 DI 10.1021/j100170a037 PG 6 WC Chemistry, Physical SC Chemistry GA GC370 UT WOS:A1991GC37000037 ER PT J AU MEOTNER, M AF MEOTNER, M TI ENTROPY-DRIVEN PROTON-TRANSFER REACTIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TEMPERATURE-DEPENDENCE; ISOTOPE EXCHANGE; ASSOCIATION; SOLVATION; KINETICS; H-2; ION AB The relation between kinetics and thermochemistry in fast reactions is examined, including reactions with substantial entropy changes. Rate constants for such reactions, in the range of (0.02-3.0) x 10(-9) cm2 s-1, were measured by pulsed high-pressure mass spectrometry. The following relations were observed: (1) The reaction efficiency in either direction is controlled uniquely and completely by the overall reaction free energy change. Specifically, the efficiency r is determined by the equilibrium constant according to r = K/(1 + K). (2) The sum of reaction efficiencies in the forward (exergonic) and reverse (endergonic) directions is near unity (r(f) + r(r) approximately-equal-to 1). These relations are observed in anionic and cationic systems, in reactions with DELTA-H-degrees up to 12 kcal/mol and with DELTA-S-degrees up to 15 cal/(mol K). Consistent with (1), reactions that are endothermic up to 7 kcal/mol can nevertheless proceed near the collision rate, when positive entropy changes make the reactions exergonic. The entropy changes are effective regardless of their structural origin. Relations analogous to (1) and (2) are also derived for reactions with multiple channels that proceed without significant barriers through a common intermediate. RP MEOTNER, M (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 23 TC 30 Z9 30 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 22 PY 1991 VL 95 IS 17 BP 6580 EP 6585 DI 10.1021/j100170a039 PG 6 WC Chemistry, Physical SC Chemistry GA GC370 UT WOS:A1991GC37000039 ER PT J AU MOSSERI, S NAHOR, GS NETA, P HAMBRIGHT, P AF MOSSERI, S NAHOR, GS NETA, P HAMBRIGHT, P TI RADIOLYTIC REDUCTION OF TETRAPYRIDYLPORPHYRINS - FORMATION OF A STABLE RADICAL FROM TETRAKIS(N-METHYL-2-PYRIDYL)PORPHYRIN SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID WATER-SOLUBLE PORPHYRINS; AQUEOUS-SOLUTION; 2-ELECTRON REDUCTION; METAL-COMPLEXES; ONE-ELECTRON; PYRIDYLPORPHYRINS; KINETICS AB One-electron and multi-electron reduction of the three isomeric free-base porphyrins derived from TMPyP [tetrakis(N-methylpyridyl)porphyrin] in aqueous solutions under various conditions have been studied by spectrophotometric pulse radiolysis and gamma-radiolysis. Similar experiments were carried out with TPyP (tetrapyridylporphyrins) in acidic solutions. Significant differences were found in the behaviour of the three isomers, in the stability of their one-electron and two-electron reduction products and in the effect of pH. An exceptionally stable radical was formed upon one-electron reduction of the ortho isomer, TM2PyP [tetrakis(N-methyl-2-pyridyl)porphyrin], at high pH. The stability of this radical is due to inhibition of protonation, a necessary step in the decay of the radical to final reduction products. Protonation is probably inhibited by the positive charges on the 2-pyridyl groups, which are very close to the meso positions of the porphyrin, and by steric effects of the ortho N-methyl groups, which inhibit deformation of the porphyrin ring and thus retard protonation. Somewhat stable radicals were also found in strongly acidic solutions of TM2PyP and T2PyP. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD. HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. NR 17 TC 16 Z9 16 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD AUG 21 PY 1991 VL 87 IS 16 BP 2567 EP 2572 DI 10.1039/ft9918702567 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GB392 UT WOS:A1991GB39200007 ER PT J AU LOEWENSTEIN, M ZWEIBEL, EG BEGELMAN, MC AF LOEWENSTEIN, M ZWEIBEL, EG BEGELMAN, MC TI COSMIC-RAY HEATING OF COOLING FLOWS - A CRITICAL ANALYSIS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC RAYS, GENERAL; GALAXIES, INTERGALACTIC MEDIUM; HYDROMAGNETICS ID THERMAL CONDUCTION; CLUSTERS; EMISSION; GALAXIES; GAS; M87 AB We present a detailed investigation of the hypothesis that a combination of magnetohydrodynamic-wave-mediated cosmic-ray heating and thermal conduction might serve to balance cooling in intracluster media and substantially reduce the rate of inflow. We show that this is a particularly promising way to heat intracluster media (ICM) for a number of reasons. Because of the form of the cosmic-ray heating, a nearly static ICM with a positive temperature gradient can exist. Because of the origin of the cosmic rays - presumed to be an active nucleus in the central galaxy fueled by residual inflow - a globally stable feedback mechanism is at work, and, in contrast to the case where conduction alone operates, no unphysical fine-tuning of parameters is required. Since, while cosmic rays dominate the heating at small cluster radii, thermal conduction dominates at large radii, an (undetectably) small cosmic-ray luminosity is required. We derive and solve the appropriate system of steady state equations that include a new, self-consistent formulation for the cosmic-ray diffusivity. Models successful in producing substantial positive temperature gradients in static configurations are indeed found, but only if conduction is reduced by a factor of 10 or more. Unfortunately, these models become cosmic-ray pressure-dominated and as a result have too-flat thermal pressure profiles when compared with the observations. This negative result is confirmed by semiempirical models which solve, simultaneously, for the required cosmic-ray pressure and wave (Alfven) speed distributions. The cosmic-ray pressure gradient can be reduced to acceptable levels only for central values of the Alfven speed considerably in excess of the local thermal sound speed. In such a case the magnetic pressure can no longer be justifiably neglected in the radial force equation, since the required reduction in conduction is presumably a result of tangled magnetic fields; this pressure would again lead to a thermal gas distribution flatter than observed. The effect of cosmic rays on the thermal stability of the ICM is also investigated, as is the role of cosmic rays in heating emission-line filaments. We find that cosmic-ray heating is unlikely either to stabilize positive density perturbations against condensation or to contribute appreciably to the powering of the optical filaments. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80302. NR 29 TC 54 Z9 54 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 AUG 20 PY 1991 VL 377 IS 2 BP 392 EP 402 DI 10.1086/170369 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GA594 UT WOS:A1991GA59400005 ER PT J AU CHIUEH, TH LI, ZY BEGELMAN, MC AF CHIUEH, TH LI, ZY BEGELMAN, MC TI ASYMPTOTIC STRUCTURE OF HYDROMAGNETICALLY DRIVEN RELATIVISTIC WINDS SO ASTROPHYSICAL JOURNAL LA English DT Article ID MAGNETOHYDRODYNAMIC WINDS; MODEL AB We study the asymptotic properties of fully relativistic, steady, axisymmetric, hydromagnetic winds. In agreement with Heyvaerts and Norman, who considered only the nonrelativistic limit, we find that all flux surfaces generally converge to either cylinders or paraboloids that are nested around the rotation axis. First we exclude asymptotically horizontal flux surfaces solely from consideration of energy and magnetic flux conservation. Then, by taking into account the cross-field force balance, we show that asymptotically current-carrying paraboloidal and conical flux surfaces cannot occur arbitrarily close to the rotation axis. Asymptotically cylindrical flux surfaces, while having no difficulty in filling out the polar region, cannot extend to infinity transversely unless the terminal velocity on the last flux surface vanishes, which renders it implausible for them to match onto other types of asymptotes. Asymptotically cylindrical flux surfaces with finite transverse radius, either self-confined or externally confined, are possible. We also show that asymptotically current-free paraboloidal flux surfaces may exist, filling up the entire space without difficulty. We show that the terminal Lorentz factor on any asymptotically cylindrical flux surface is directly proportional to the current enclosed within that surface, provided that the surface extends to a radius well beyond the light cylinder. For current-free paraboloidal surfaces, all of the energy in the flow goes asymptotically into kinetic energy, in sharp contrast to other flow geometries in which the Poynting flux remains important at large distances. The results presented here are potentially important for understanding the structures of relativistic jets in active galactic nuclei and of pulsar winds. C1 NATL CENT UNIV,INST PHYS & ASTRON,CHUNGLI 32054,TAIWAN. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. OI CHIUEH, TZI-HONG/0000-0003-2654-8763 NR 24 TC 99 Z9 99 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 AUG 20 PY 1991 VL 377 IS 2 BP 462 EP 466 DI 10.1086/170375 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GA594 UT WOS:A1991GA59400011 ER PT J AU LOPEZ, RE PASSI, RM AF LOPEZ, RE PASSI, RM TI SIMULATIONS IN SITE ERROR ESTIMATION FOR DIRECTION FINDERS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB The performance of an algorithm for the recovery of site-specific errors of direction finder (DF) networks is tested under controlled simulated conditions. The simulations show that the algorithm has some inherent shortcomings for the recovery of site errors from the measured azimuth data. These limitations are fundamental to the problem of site error estimation using azimuth information. Several ways for resolving or ameliorating these basic complications are tested by means of simulations. From these it appears that for the effective implementation of the site error determination algorithm, one should design the networks with at least four DFs, improve the alignment of the antennas, and increase the gain of the DFs as much as it is compatible with other operational requirements. The use of a nonzero initial estimate of the site errors when working with data from networks of four or more DFs also improves the accuracy of the site error recovery. Even for networks of three DFs, reasonable site error corrections could be obtained if the antennas could be well aligned. C1 STENNIS SPACE CTR, INST NAVAL OCEANOG, BAY ST LOUIS, MS USA. RP LOPEZ, RE (reprint author), NOAA, NATL SEVERE STORMS LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 9 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1991 VL 96 IS D8 BP 15287 EP 15296 DI 10.1029/91JD01398 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GC314 UT WOS:A1991GC31400004 ER PT J AU MCKEEN, SA HSIE, EY LIU, SC AF MCKEEN, SA HSIE, EY LIU, SC TI A STUDY OF THE DEPENDENCE OF RURAL OZONE ON OZONE PRECURSORS IN THE EASTERN UNITED-STATES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BIOGENIC HYDROCARBON EMISSIONS; NATURAL HYDROCARBONS; PHOTOCHEMICAL SMOG; NITROGEN-OXIDES; MODELS; URBAN; AIR; SENSITIVITY; MECHANISMS; EUROPE AB A comprehensive three-dimensional mesoscale model, with detailed treatment of meteorology and photochemistry, is applied to the eastern United States and southeastern Canada to address the issue of ozone production over rural regions. Simulations with various anthropogenic emission reductions over a 4-day high-pressure period, for which the eastern U.S. experienced elevated O3 levels, are compared to the results of a reference case that incorporates the most recent National Acid Precipitation Assessment Program (1985) emissions inventory. Our focus is on the relative effects of anthropogenic NO(x) versus nonmethane hydrocarbons (NMHC) emission reductions on O3 concentrations within this photochemical regime. The model results are consistent with earlier studies that predict a reasonably high O3 sensitivity to NMHC emission reductions, and O3 increases for NO(x) emission reductions in regions of strong urban influence. However, the total area that exhibits these distinctly urban characteristics comprises less than 10% of the continental area within the model. O3 production for the majority of the eastern United States is found to be limited by NO(x) availability rather than NMHC. Thus the sensitivity to NO(x) emission reductions averaged over the continental regions of the model domain is about a factor of 3 higher than that of NMHC. Because of large uncertainties in the natural and anthropogenic NMHC emissions, additional sensitivity runs are performed with increased anthropogenic NMHC emissions and natural NMHC emissions excluded. These alterations do not effect our basic conclusions with respect to rural O3 formation but do impact urban locations. When anthropogenic NMHC emissions are increased by a factor of 4, control of NO(x) emissions has nearly the same effect in both urban and rural areas. The nonlinear nature of regionally averaged O3 with respect to anthropogenic and natural precursors is also illustrated from the results of the sensitivity studies. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP MCKEEN, SA (reprint author), NOAA, ENVIRONM RES LAB, AERON LAB, 325 BROADWAY, BOULDER, CO 80302 USA. RI McKeen, Stuart/H-9516-2013; Hsie, Eirh-Yu/I-4449-2013 OI Hsie, Eirh-Yu/0000-0003-3934-9923 NR 50 TC 101 Z9 116 U1 2 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1991 VL 96 IS D8 BP 15377 EP 15394 DI 10.1029/91JD01282 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GC314 UT WOS:A1991GC31400011 ER PT J AU LOWE, DC BRENNINKMEIJER, CAM TYLER, SC DLUGKENCKY, EJ AF LOWE, DC BRENNINKMEIJER, CAM TYLER, SC DLUGKENCKY, EJ TI DETERMINATION OF THE ISOTOPIC COMPOSITION OF ATMOSPHERIC METHANE AND ITS APPLICATION IN THE ANTARCTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; POLAR ICE CORES; NEW-ZEALAND; CARBON-DIOXIDE; BARING HEAD; CH4; TROPOSPHERE; OXIDATION; RECORD; TRENDS AB A procedure for the determination of the C-13/C-12 ratio and the C-14 abundance in atmospheric methane is presented. The method is based on the collection of air samples in stainless steel tanks at a pressure of 7 bar. The air is processed in the laboratory by cryogenic removal of condensibles, followed by oxidation of the methane content after which the resulting CO2 is collected. Also CO is removed prior to oxidation. The C-13/C-12 ratio is determined on the CO2 sample by stable isotope ratio mass spectrometry. The C-14 content is determined by means of accelerator mass spectrometry. The overall precision of the technique is 0.1 parts per thousand for delta-C-13 and 1.5 pMC for C-14. The method has been used to determine the carbon isotopic composition of methane in air collected at Baring Head, New Zealand, and also in air collected on aircraft flights between New Zealand and Antarctica. No gradient in the carbon isotopic composition between Baring Head and South Pole station was detected. The annual mean delta-C-13 value at Baring Head was -47.13 +/- 0.20 parts per thousand for 1989 which includes seasonal effects probably due to OH variations and local meteorology. The annual mean C-14 value at Baring Head in 1989 was 118.3 percent modern (pMC). C1 NATL CTR ATMOSPHER RES, DIV ATMOSPHERE CHEM, BOULDER, CO 80307 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP LOWE, DC (reprint author), DSIR, DIV PHYS SCI, NUCL SCI GRP, POB 31-312, LOWER HUTT, NEW ZEALAND. RI Brenninkmeijer, Carl/B-6860-2013 NR 54 TC 61 Z9 64 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1991 VL 96 IS D8 BP 15455 EP 15467 DI 10.1029/91JD01119 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GC314 UT WOS:A1991GC31400017 ER PT J AU MCKENZIE, RL JOHNSTON, PV MCELROY, CT KERR, JB SOLOMON, S AF MCKENZIE, RL JOHNSTON, PV MCELROY, CT KERR, JB SOLOMON, S TI ALTITUDE DISTRIBUTIONS OF STRATOSPHERIC CONSTITUENTS FROM GROUND-BASED MEASUREMENTS AT TWILIGHT SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITROGEN-DIOXIDE; ABSORPTION-MEASUREMENTS; MCMURDO STATION; NO2; SPECTROSCOPY; 45-DEGREES-S; ANTARCTICA; WINTER; O3 AB A technique for extracting height profiles from ground-based column measurements at twilight is introduced. Its sensitivities to chemical processes, initialization, and air mass factors are investigated. The method is applied to observations made at Lauder, New Zealand, in 1987. The technique provides information on the vertical structure of atmospheric absorbers such as ozone or NO2 from the surface to about 50 km and is particularly valuable for identifying the influence of pollution on such measurements. When tropospheric pollution is low, it yields profiles in reasonable agreement with model predictions and with satellite measurements. C1 ATMOSPHER ENVIRONM SERV, TORONTO, ONTARIO, CANADA. NOAA, ENVIRONM RES LAB, BOULDER, CO 80303 USA. RP MCKENZIE, RL (reprint author), DSIR, CENT OTAGO 9182, NEW ZEALAND. NR 25 TC 73 Z9 75 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 AUG 20 PY 1991 VL 96 IS D8 BP 15499 EP 15511 DI 10.1029/91JD01361 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GC314 UT WOS:A1991GC31400020 ER PT J AU HEMPELMANN, R RICHTER, D RUSH, JJ ROWE, JM AF HEMPELMANN, R RICHTER, D RUSH, JJ ROWE, JM TI HYDROGEN SITE DISTRIBUTION IN THE ALLOY SYSTEM NB100-XVXHY STUDIED BY NEUTRON VIBRATIONAL SPECTROSCOPY SO JOURNAL OF THE LESS-COMMON METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON METAL-HYDROGEN SYSTEMS, FUNDAMENTALS AND APPLICATIONS CY SEP 02-07, 1990 CL BANFF, CANADA SP ALCAN INT, ATOM ENERGY CANADA, ERGENICS, KOGAKUIN UNIV, DEPT CHEM ENGN, MANITOBA ENERGY AUTHORITY, MAT & ENERGY RES INST JAPAN, ONTARIO HYDRO, RES DIV, UNIV TORONTO, DEPT PHYS ID AMORPHOUS METALS; SCATTERING AB Nb100-xVxHy is a random b.c.c. alloy with a hydrogen sublattice disordered with respect to site energies. We have determined the energetically most favourable hydrogen sites by means of neutron vibrational spectroscopy, which is a powerful tool for this purpose when the translational symmetry is strongly reduced. In Nb95V5Hy, Nb90V10Hy and Nb50V50Hy both octahedral and tetrahedral site occupation was observed. On the basis of spectroscopic and statistical arguments we assign the low temperature vibrational peaks in the niobium-rich Nb-V-H alloys at low hydrogen content to Nb4V2 octahedral and NbV3 tetrahedral sites. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP HEMPELMANN, R (reprint author), FORSCHUNGSZENTRUM JULICH,INST FESTKORPERFORSCH,W-517 JULICH,GERMANY. RI Rowe, J Michael Rowe/D-2943-2013; Richter, Dieter/H-3701-2013 OI Richter, Dieter/0000-0003-0719-8470 NR 24 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-5088 J9 J LESS-COMMON MET PD AUG 20 PY 1991 VL 172 BP 281 EP 292 PN A PG 12 WC Chemistry, Physical; Metallurgy & Metallurgical Engineering SC Chemistry; Metallurgy & Metallurgical Engineering GA GF951 UT WOS:A1991GF95100034 ER PT J AU SAKURAI, S JINNAI, H HASEGAWA, H HASHIMOTO, T HAN, CC AF SAKURAI, S JINNAI, H HASEGAWA, H HASHIMOTO, T HAN, CC TI MICROSTRUCTURE EFFECTS ON THE LOWER CRITICAL SOLUTION TEMPERATURE PHASE-BEHAVIOR OF DEUTERATED POLYBUTADIENE AND PROTONATED POLYISOPRENE BLENDS STUDIED BY SMALL-ANGLE NEUTRON-SCATTERING SO MACROMOLECULES LA English DT Article ID POLYVINYL METHYL-ETHER); POLYMER BLENDS; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); POLYSTYRENE; MISCIBILITY; MIXTURES; MODEL AB The miscibility of a blend of protonated polyisoprene (HPI) with the 3,4-linkage microstructure in the range 7-15% and of deuterated polybutadiene (DPB) with the 1,2-linkage microstructure in the range 12-28% was studied by small-angle neutron scattering (SANS). It was found that all blends studied here show lower critical solution temperature (LCST) type phase behaviors; i.e., the phase separation occurs by raising the temperature. It was also found that the miscibility is quite sensitive to the microstructures of the polydienes used. The effective thermodynamic interaction parameter chi-eff per segment between two polymers was determined by fitting SANS data in the single-phase state with a theoretical scattering curve obtained on the basis of the random-phase approximation. The temperature dependence of chi-eff showed a systematic change with the microstructure. For a given HPI, the chi-eff values decreased, and therefore, the blends became more miscible, with an increase in the vinyl content (i.e., 1,2-linkage content) in DPB. On the contrary, for a given DPB, the values increased, and therefore, the blends became more immiscible, with an increase in the vinyl content (i.e., 3,4-linkage content) in HPI. We proposed an alternative explanation for the LCST phase behavior based on treatment for the random copolymer blends. C1 KYOTO UNIV,FAC ENGN,DEPT POLYMER CHEM,KYOTO 606,JAPAN. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI Jinnai, Hiroshi/F-8456-2014 NR 27 TC 49 Z9 49 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 19 PY 1991 VL 24 IS 17 BP 4839 EP 4843 DI 10.1021/ma00017a018 PG 5 WC Polymer Science SC Polymer Science GA GB747 UT WOS:A1991GB74700018 ER PT J AU SAKURAI, S IZUMITANI, T HASEGAWA, H HASHIMOTO, T HAN, CC AF SAKURAI, S IZUMITANI, T HASEGAWA, H HASHIMOTO, T HAN, CC TI SMALL-ANGLE NEUTRON-SCATTERING AND LIGHT-SCATTERING STUDY ON THE MISCIBILITY OF POLY(STYRENE-RAN-BUTADIENE) POLYBUTADIENE BLENDS SO MACROMOLECULES LA English DT Article ID SPINODAL DECOMPOSITION; POLYMER BLENDS; INTERACTION PARAMETER; PHASE-BEHAVIOR; MIXTURES; MODEL AB The miscibility of binary blends of polybutadiene (PB) and poly(styrene-ran-butadiene) (SBR) was studied on the basis of segmental interaction parameters. In this analysis PB was assumed to be a random copolymer comprising 1,2-linkages (V) and 1,4-linkages (B) and SBR to be the one comprising styrene (S) and butadiene with V and B. The segmental interaction parameters between V and S (chi-vs), B and S (chi-BS), and V and B (chi-VB) were determined on the basis of the copolymer blend theory from the effective interaction parameters (chi-eff'S) for the blends of PB and SBR, and those for poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS), with different copolymer compositions and microstructures of polybutadienes. The values chi-eff were determined from either the small-angle neutron or X-ray scattering of the mixtures in the single-phase state. By use of these segmental interaction parameters, chi-VS, chi-BS, and chi-VB, the miscibility of the SBR/PB blends was predicted for a given set of V, B, and S contents in PB and SBR. The predictions of the miscibility for several SBR/PB blends agreed well with the results of the light scattering experiments. C1 KYOTO UNIV,FAC ENGN,DEPT POLYMER CHEM,SAKYO KU,KYOTO 606,JAPAN. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 28 TC 20 Z9 20 U1 5 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 19 PY 1991 VL 24 IS 17 BP 4844 EP 4851 DI 10.1021/ma00017a019 PG 8 WC Polymer Science SC Polymer Science GA GB747 UT WOS:A1991GB74700019 ER PT J AU LEVIN, JC LINDLE, DW KELLER, N MILLER, RD AZUMA, Y MANSOUR, NB BERRY, HG SELLIN, IA AF LEVIN, JC LINDLE, DW KELLER, N MILLER, RD AZUMA, Y MANSOUR, NB BERRY, HG SELLIN, IA TI MEASUREMENT OF THE RATIO OF DOUBLE-TO-SINGLE PHOTOIONIZATION OF HELIUM AT 2.8 KEV USING SYNCHROTRON RADIATION SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOUBLE IONIZATION; RARE-GASES; THRESHOLD; IMPACT AB We report the first measurement of the ratio of double-to-single photoionization of helium well above the double-ionization threshold. Using a time-of-flight technique, we find He++/He+ = 1.6% +/- 0.3% at hv = 2.8 keV. This value lies between calculations by Amusia (2.3%) and by Samson, who predicts 1.2% by analogy with electron-impact ionization cross sections of singly charged ions. Good agreement is obtained with older shake calculations of Byron and Joachain, and of Aberg, who predict 1.7%. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP LEVIN, JC (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 26 TC 86 Z9 86 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 19 PY 1991 VL 67 IS 8 BP 968 EP 971 DI 10.1103/PhysRevLett.67.968 PG 4 WC Physics, Multidisciplinary SC Physics GA GB699 UT WOS:A1991GB69900010 ER PT J AU OVERPECK, JT AF OVERPECK, JT TI PALEOCLIMATOLOGY - CROWLEY,TJ, NORTH,GR SO SCIENCE LA English DT Book Review RP OVERPECK, JT (reprint author), NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 16 PY 1991 VL 253 IS 5021 BP 804 EP 805 DI 10.1126/science.253.5021.804 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GB295 UT WOS:A1991GB29500047 PM 17835501 ER PT J AU THROWER, FP SHORT, JW AF THROWER, FP SHORT, JW TI ACCUMULATION AND PERSISTENCE OF TRI-NORMAL-BUTYLTIN IN PINK AND CHUM SALMON FRY CULTURED IN MARINE NET-PENS SO AQUACULTURE LA English DT Article ID CHINOOK SALMON AB Pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta) fry cultured in tri-n-butyltin (TBT) treated marine net-pens for 20-68 days were tested just prior to release into the ocean to determine whether TBT contamination had occurred and, if so, to what extent. Exposed fry contained 0.2-7.3-mu-g TBT/g fish at the time of release; TBT concentrations varied substantially among the net-pen populations. Unusually high mortalities or poor growth rates were not observed. TBT was not detected in the returning adults. RP THROWER, FP (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,11305 GLACIER HIGHWAY,JUNEAU,AK 99801, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD AUG 15 PY 1991 VL 96 IS 3-4 BP 233 EP 239 DI 10.1016/0044-8486(91)90153-X PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GC371 UT WOS:A1991GC37100004 ER PT J AU NANCE, JM AF NANCE, JM TI EFFECTS OF OIL GAS-FIELD PRODUCED WATER ON THE MACROBENTHIC COMMUNITY IN A SMALL GRADIENT ESTUARY SO HYDROBIOLOGIA LA English DT Article DE PRODUCED WATER; HYDROCARBONS; OIL POLLUTION; MACROBENTHOS; ESTUARINE ID BUCCANEER OILFIELD; SEDIMENTS; ALKANES AB Little is known about how climatic events (i.e., drought) inhibit or enhance movement of petroleum hydrocarbon laden sediments in estuarine systems and how this in turn effects the macrobenthic populations exposed to these sediments. Seventeen collection stations were established and monitored at New Bayou, Texas, a small gradient estuary which receives petroleum products via oil/gas field produced water discharge. Hydrographic, geologic and biotic samples were taken monthly from each station during a period of reduced rainfall. Both temperature and dissolved oxygen data taken during the study followed patterns typical for the area. Salinity values increased into the polyhaline range at near-bay stations during the reduced rain period, while upper bayou stations remained within the oligohaline range. Sediment grain sizes along the bayou were generally in the silty-clay range. Sediment hydrocarbon concentrations were highest (11.4 mg g-1 dry sediment) around the produced water discharge site and lowest at near-bay stations (0.2 mg g-1 dry sediment). Ninety-six macrobenthic species were collected during the study. General effects from produced water discharge on macrobenthic populations followed the classical pattern outlined by other research in shallow bay systems. A sediment hydrocarbon concentration of 2.5 mg g-1 dry sediment was found to reflect the average value needed to depress population abundances. Both abundance and diversity values were lowest at central stations near the discharge site. This zone of depressed macrobenthic populations extended from the discharge site at least 107 m downstream and 46 m upstream. The zone of stimulated macrobenthic populations occurred 1486 m downstream and 381 m upstream from the discharge site. RP NANCE, JM (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES CTR,GALVESTON LAB,4700 AVE U,GALVESTON,TX 77551, USA. NR 55 TC 7 Z9 7 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD AUG 15 PY 1991 VL 220 IS 3 BP 189 EP 204 DI 10.1007/BF00006575 PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GK310 UT WOS:A1991GK31000002 ER PT J AU LOONEY, JP ROSASCO, GJ AF LOONEY, JP ROSASCO, GJ TI SEMICLASSICAL CALCULATION OF SELF-BROADENING IN O2, N2, AND CO RAMAN-SPECTRA SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATION VIBRATION LINES; ASYMMETRIC-TOP MOLECULES; DIODE-LASER MEASUREMENTS; Q-BRANCH; VIRIAL-COEFFICIENTS; TEMPERATURE-DEPENDENCE; THEORETICAL-ANALYSIS; LIGHT-SCATTERING; CARBON-MONOXIDE; IMPACT THEORY AB Semiclassical calculations of the J and temperature dependence of the Raman Q1 and S0 self-broadened linewidths of O2, N2, and CO have been performed within the framework of Robert and Bonamy [J. Phys. (Paris) 10, 923 (1979)] with J = 0-30 and T = 300-1500 K. The calculation of the CO self-broadened R1 linewidths are also reported for T = 100-300 K and J = 0-20. Comparison of the results of these calculations with recent experiments shows good overall agreement. C1 NATL INST STAND & TECHNOL,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899. RP LOONEY, JP (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 57 TC 22 Z9 22 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 AUG 15 PY 1991 VL 95 IS 4 BP 2379 EP 2390 DI 10.1063/1.460944 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GA108 UT WOS:A1991GA10800017 ER PT J AU STEGER, JM CARTON, JA AF STEGER, JM CARTON, JA TI LONG WAVES AND EDDIES IN THE TROPICAL ATLANTIC-OCEAN - 1984-1990 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-SURFACE TEMPERATURE; INSTABILITY WAVES; EQUATORIAL WAVES; SEASONAL CYCLE; PACIFIC; SATELLITE; VELOCITY AB Weekly images of sea surface temperature (SST) have been constructed for the tropical Atlantic Ocean for May-September, 1984-1990, from National Oceanic and Atmospheric Administration National Environmental Satellite, Data, and Information Service satellite-derived sea surface temperature data. These images have been analyzed to determine weekly to seasonal changes in the position of the fronts between the cold equatorial water and the warmer waters to the north and south. We have found that long waves along the northern front (previously reported by Legeckis and Reverdin (1987)) are present each year, although their number, strength, and duration vary. The year 1987 was the most atypical, with only a few short-lived waves seen. The long waves typically appear in SST in mid-June and last into September. They form along the equatorial thermal front between 5-degrees-W and 30-degrees-W and propagate westward, sometimes reaching 45-degrees-W. Wave crests travel at speeds varying between 10 and 40 cm/s, but variations in amplitude reveal that the group velocity of the waves is eastward at 30 cm/s. Long-wave crests are observed to be associated with mesoscale anticyclonic warm-core eddies, which apparently play a significant role in cross-equatorial heat transport. Instability features are also observed along the southern front of the equatorial cold tongue, although because of weaker thermal gradients they are less distinct. Southern waves propagate westward along the front at speeds and wavelengths similar to the long waves in the north. There is no simple phase relationship between long waves and the southern waves, which suggests that the southern waves are not the direct result of the northern long waves. C1 UNIV MARYLAND,DEPT METEOROL,CTR OCEAN LAND ATMOSPHERE INTERACT,COLLEGE PK,MD 20742. RP STEGER, JM (reprint author), NOAA,NESDIS,SATELLITE APPLICAT LAB,WASHINGTON,DC 20233, USA. RI carton, james/C-4807-2009 OI carton, james/0000-0003-0598-5198 NR 21 TC 19 Z9 19 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 1991 VL 96 IS C8 BP 15161 EP 15171 DI 10.1029/91JC01316 PG 11 WC Oceanography SC Oceanography GA GB337 UT WOS:A1991GB33700032 ER PT J AU VEMURI, G AF VEMURI, G TI EXPERIMENTAL INVESTIGATION OF NEAR THRESHOLD BEHAVIOR OF A DYE-LASER WITH SWEPT CAVITY LOSSES SO OPTICS COMMUNICATIONS LA English DT Article ID ADDITIVE WHITE NOISE; DELAYED BIFURCATIONS; RANDOM FLUCTUATIONS; DYNAMICS; PARAMETER; TRANSIENTS; CO2-LASER; MODEL AB The cavity losses of a ring dye laser are slowly swept in time by an intracavity acousto-optic modulator. Under the influence of this sweep, the pump parameter for laser turn-on is delayed beyond the value for the laser growth purely under the influence of spontaneous emission. This delay is a stochastic quantity since laser turn-on is dominated by spontaneous emission, and is found to be a function of the sweep frequency. In our experiment, the mean delay was found to scale as the square root of the sweep frequency and the variance of the delay varied linearly with the sweep frequency. The results are in qualitative agreement with those reported in the literature. Further, for a given sweep rate, the delay was independent of how far the laser intensity grows toward saturation. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. RP VEMURI, G (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD AUG 15 PY 1991 VL 85 IS 1 BP 36 EP 42 DI 10.1016/0030-4018(91)90048-I PG 7 WC Optics SC Optics GA GE599 UT WOS:A1991GE59900008 ER PT J AU WOICIK, JC KENDELEWICZ, T MIYANO, KE COWAN, PL BOULDIN, CE KARLIN, BA PIANETTA, P SPICER, WE AF WOICIK, JC KENDELEWICZ, T MIYANO, KE COWAN, PL BOULDIN, CE KARLIN, BA PIANETTA, P SPICER, WE TI DETERMINATION OF THE SB/SI(111) INTERFACIAL STRUCTURE BY BACK-REFLECTION X-RAY STANDING WAVES AND SURFACE EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE SO PHYSICAL REVIEW B LA English DT Note AB Based on the surface extended x-ray-absorption fine-structure (SEXAFS) absolute surface coordination numbers, Woicik el al. [Phys. Rev. B 43, 4331 (1991)] argued that Sb trimers adsorb on the Si(111) surface in a modified "bridge" configuration rotated by 60-degrees relative to the atop "milk stool" geometry proposed by Abukawa, Park, and Kono (Surf. Sci. Lett. 201, 513 (1988)). Using the accurate near-neighbor bond lengths as determined from SEXAFS, these models predict perpendicular distances of 1.76 and 2.60 angstrom between the top Si atoms and the Sb layer, respectively. New back-reflection x-ray standing-wave data find the Sb atoms to reside 2.53 +/- 0.1 angstrom above the Si surface, in clear support of the milk stool geometry. Polarization-dependent SEXAFS relative coordination numbers support the milk stool model as well. C1 STANFORD UNIV,STANFORD ELECTR LAB,STANFORD,CA 94305. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP WOICIK, JC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 35 Z9 35 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 15 PY 1991 VL 44 IS 7 BP 3475 EP 3478 DI 10.1103/PhysRevB.44.3475 PG 4 WC Physics, Condensed Matter SC Physics GA GC066 UT WOS:A1991GC06600098 ER PT J AU GILLIES, JZ GILLIES, CW LOVAS, FJ MATSUMURA, K SUENRAM, RD KRAKA, E CREMER, D AF GILLIES, JZ GILLIES, CW LOVAS, FJ MATSUMURA, K SUENRAM, RD KRAKA, E CREMER, D TI VANDERWAALS COMPLEXES OF CHEMICALLY REACTIVE GASES - OZONE ACETYLENE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON CORRELATION-ENERGY; MICROWAVE-SPECTRUM; MOLECULAR-STRUCTURE; DIPOLE-MOMENT; PERTURBATION-THEORY; WATER DIMER; ETHYLENE; CONSTANTS; SPECTROSCOPY; OZONOLYSIS AB A pulsed-beam Fabry-Perot cavity Fourier-transform microwave spectrometer was used to observe rotational spectra of the normal, d1- and d2-isotopic species of the ozone-acetylene van der Waals complex. The work employed a modified, pulsed-solenoid valve which served as a flow reactor to sample the reacting gas mixture of 1% ozone and 1% acetylene in argon. The c-type transitions of the three isotopic species were split into tunneling doublets due to an internal rotation of acetylene which exchanges the hydrogen (deuterium) atoms. Spectral constants of the two tunneling states for each isotopic species were obtained independently from fits to an asymmetric top Watson Hamiltonian. Stark effect measurements for O3-C2H2 gave mu-a = 0.041 (1) and mu-c = 0.473 (1) D. The microwave data show the complex has C(s) symmetry with the molecular axis of acetylene located parallel to the OOO plane of ozone at a center-of-mass separation of R(cm) = 3.251 (2) angstrom. Ab initio calculations at the MP4(SDQ)/6-31G(d,p) level have found the terminal oxygens of ozone are tilted symmetrically toward the molecular axis of acetylene. The combined microwave and ab initio results indicate that the interaction potential surface of ozone plus acetylene is quite similar to ozone plus ethylene at van der Waals distances. C1 RENSSELAER POLYTECH INST, DEPT CHEM, TROY, NY 12180 USA. SIENA COLL, DEPT CHEM, LOUDONVILLE, NY 12211 USA. NATL INST STANDARDS & TECHNOL, DIV MOLEC PHYS, GAITHERSBURG, MD 20899 USA. GOTHENBURG UNIV, S-41296 GOTHENBURG, SWEDEN. NR 56 TC 41 Z9 43 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 14 PY 1991 VL 113 IS 17 BP 6408 EP 6415 DI 10.1021/ja00017a008 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA GB298 UT WOS:A1991GB29800008 ER PT J AU KRAUSS, M GARMER, DR AF KRAUSS, M GARMER, DR TI ACTIVE-SITE IONICITY AND THE MECHANISM OF CARBONIC-ANHYDRASE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PROTON MAGNETIC-RESONANCE; CATALYTIC MECHANISM; MOLECULAR-BASIS; ZINC; BINDING; CO2; IMIDAZOLE; HYDRATION; ABINITIO; WATER AB We report ab initio calculations on a cluster model for the active site of the enzyme carbonic anhydrase that considers the effect of the ionicity of the site on the energetics of ligand binding and reaction behavior. Hydrolysis occurs by a direct attack of the Zn-bound hydroxyl oxygen on the carbon atom of CO2 with a small activation energy. The final product state in the cluster model has bicarbonate bound by one short and one long metal to oxygen bond. Detailed mechanisms for the initial attack of OH- on CO2 and proton movement out to the free oxygen atom were studied by locating intermediates and transition states. Two mechanisms for rearrangement of bound bicarbonate to its most stable form are found to have low barriers. The first involves rocking of the bicarbonate from the initial intermediate. The second accomplishes this shift by a cyclic exchange of protons with a hydrogen-bound water or Thr-119. A Glu residue is hydrogen bonded to N(E2) of a tripod His in known carbonic anhydrase structures. Model calculations indicate the possibility of proton transfer to Glu simultaneous with the protonation of zinc-bound hydroxyl, which may explain observed NMR shifts of the histidine protons as a function of pH. Regardless of the proton position, the anionic residue qualitatively changes the electrostatic potentials in the active site region and the binding energies of other anionic ligands. The presence of the anionic residue is important in the release of product bicarbonate and also increases the exothermicity of the initial hydrolysis step. Binding of the CO2 substrate is essentially unaffected by the presence of the anionic residue and also by the deprotonation of the metal-bound water, explaining the lack of any dependence on the pH of the Michaelis-Menten parameter K(M). Available coordination sites were examined for clusters of zinc and three ammonias with two waters, hydroxyl and water, or thiocyanate anion and water. The proton affinity of bound hydroxyl was unaffected by an increase in the zinc coordination number. In the presence of an anionic ligand, water is energetically favored as a second-shell ligand hydrogen-bound to the anionic ligand rather than as a fifth ligand bound to the Zn cation. The thiocyanate structure agrees well with experiment. C1 MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP KRAUSS, M (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 50 TC 44 Z9 44 U1 0 U2 1 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 AUG 14 PY 1991 VL 113 IS 17 BP 6426 EP 6435 DI 10.1021/ja00017a011 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA GB298 UT WOS:A1991GB29800011 ER PT J AU CONTI, PS AF CONTI, PS TI WOLF-RAYET GALAXIES - AN INTRODUCTION AND A CATALOG SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, STELLAR CONTENT; STARS, WOLF-RAYER ID H-II-REGIONS; EMISSION-LINES; MASSIVE STARS; ACTIVE-CENTER; EVOLUTION; SPECTROSCOPY; POPULATION; STARBURST; SPECTRA; MERGER AB The first catalog of Wolf-Rayet galaxies is presented and discussed. These are a subset of emission-line galaxies in which a broad 4686 He II emission feature due to Wolf-Rayet (W-R) stars is observed in the integrated spectrum. About one-quarter of these galaxies also show a broad line at 4640 angstrom due to N III which is prominent in the latest type WN stars. The number of Lyman-continuum photons emitted by W-R galaxies scales roughly with their integrated magnitudes, similar to emission-line galaxies. Both W-R galaxies and emission-line galaxies form an overlap with and luminous extension of giant H II regions in these properties. The fraction of W-R stars to O stars in some of these galaxies appears to be large, which if confirmed by more detailed quantitative work would imply that the initial mass function was relatively "flat." There is also another small subset of emission-line galaxies in which a narrow 4686 He II emission feature is found-this is likely a recombination nebular line whose excitation mechanism is uncertain. RP CONTI, PS (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 78 TC 217 Z9 217 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1991 VL 377 IS 1 BP 115 EP 125 DI 10.1086/170340 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ463 UT WOS:A1991FZ46300011 ER PT J AU VOIT, GM AF VOIT, GM TI ENERGY DEPOSITION BY X-RAY PHOTOELECTRONS INTO INTERSTELLAR MOLECULAR CLOUDS SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC PROCESSES; INTERSTELLAR, MOLECULES; RADIATIVE TRANSFER ID R-MATRIX CALCULATION; TOTAL CROSS-SECTIONS; ELECTRON-IMPACT; VIBRATIONAL-EXCITATION; VACUUM ULTRAVIOLET; HELIUM; HYDROGEN; STATES; EMISSION; 23S AB In certain astrophysical systems, high-energy photoelectrons will deposit their kinetic energy into molecular gas, exciting numerous molecular and atomic levels. We consider the deposition of energy by 100-10,000 eV electrons into molecular hydrogen and helium gas of cosmic abundances (n(He) = 0.2n(H-2)) and fractional ionization ranging from 10(-12) to 10(-1). In order to account for energy deposition by both discrete and continuous degradation processes, we introduce the loss spectrum, a form of the Spencer-Fano degradation spectrum particularly suited to describing electron energy deposition in a partially ionized gas. We include rotational and vibrational excitations of H-2 as well as electronic excitations and ionizations of H-2 and He0. The calculated excitation and ionization yields drop as the fractional ionization increases. We fitted the dependences of these yields on fractional ionization to a form suitable for swift numerical computation. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. OI Voit, Gerard/0000-0002-3514-0383 NR 37 TC 33 Z9 33 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 AUG 10 PY 1991 VL 377 IS 1 BP 158 EP 170 DI 10.1086/170344 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ463 UT WOS:A1991FZ46300015 ER PT J AU CARPENTER, KG ROBINSON, RD WAHLGREN, GM AKE, TB EBBETS, DC LINSKY, JL BROWN, A WALTER, FM AF CARPENTER, KG ROBINSON, RD WAHLGREN, GM AKE, TB EBBETS, DC LINSKY, JL BROWN, A WALTER, FM TI 1ST RESULTS FROM THE GODDARD HIGH-RESOLUTION SPECTROGRAPH - THE CHROMOSPHERE OF ALPHA-TAURI SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, CHROMOSPHERES; STARS, INDIVIDUAL (ALPHA-TAU); STARS, LATE-TYPE; ULTRAVIOLET, SPECTRA ID EMISSION-LINES; STARS AB The K5 III star-alpha-Tau was observed with the Goddard High Resolution Spectrograph on 1990 November 27 as part of the Science Assessment Program for the Hubble Space Telescope. The observations include spectra in both the Large and Small Science Apertures in modes G270M at 2345 angstrom and echelle B at 2325 angstrom. The spectra show intersystem and permitted chromospheric emission lines of C II], Si II], Fe II, Fe I, Ni II, and Co II. Resolved profiles of the C II] lines indicate a complex chromospheric turbulent velocity distribution with mean value of almost-equal-to 24 km s-1, while their observed wavelengths indicate a 4 km s-1 downflow of the C II] plasma. Twenty-five new emission lines have been found in the 2320-2370 angstrom region, 17 of which have been identified with the aid of Skylab data obtained above the solar limb, including four lines from Co II (UV 8) and an Fe I (UV 12) line. The Co II lines confirm the earlier identification of the 2330 angstrom line as a Co II (UV 8) fluorescent feature, and the Fe I line represents a third product of the Mg II kappa-Fe I pumping which produces the Fe I (UV 44) lines near 2823 and 2844 angstrom. The Skylab spectrum shows different line strengths due to the higher density and lower optical depths of the solar chromosphere above the visible limb. C1 NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,ASTRON PROGRAM,GREENBELT,MD 20771. BALL AEROSP SYST GRP,GHRS PROJECT,BOULDER,CO 80306. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. SUNY STONY BROOK,STONY BROOK,NY 11794. RP CARPENTER, KG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,CODE 681,GREENBELT,MD 20771, USA. RI Carpenter, Kenneth/D-4740-2012 NR 15 TC 35 Z9 35 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 AUG 10 PY 1991 VL 377 IS 1 BP L45 EP L48 DI 10.1086/186113 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ464 UT WOS:A1991FZ46400013 ER PT J AU FAHR, A BRAUN, W KLEIN, R DORKO, W OKABE, H AF FAHR, A BRAUN, W KLEIN, R DORKO, W OKABE, H TI PHOTOCHEMISTRY OF TRIMETHYL ARSINE AT 193 NM SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID ULTRAVIOLET; PHOTOLYSIS; PYROLYSIS; SYSTEMS; ALANE; CH3ZN AB The photodecomposition of trimethyl arsine results in fragments/products that exhibit numerous UV overlapping absorptions. Nevertheless, quantum yields of CH3, intramolecular C2H6, As(CH3) and As(CH3)2 production can be obtained as 1.25, 0, 0.25 and 0.75, respectively, employing both quantitative spectroscopic detection of CH3 at 216.4 nm and GC-mass spectral analysis of isotopically labelled ethane end-products. The isotopic experiments employed photolysis of mixtures of As(CH3)3 and (CD3)2CO, the latter providing the actinometric standard. Two absorptions attributed to As(CH3)2 were monitored by kinetic spectroscopy and a schematic mechanism describing the system is proposed. Some distinguishing features of the mechanism include: (1) the quantum yields appear to be independent of pressure, (2) rates of reaction of CH3 with arsenic-containing fragments are slower than that of CH3 combination, (3) a metastable absorption attributed to As(CH3)2 was observed, the rate constant for its quenching by helium to the ground state was measured. C1 NBS,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. HOWARD UNIV,DEPT CHEM & MAT SCI,EXCELLENCE RES CTR,WASHINGTON,DC 20059. RP FAHR, A (reprint author), NBS,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 26 TC 9 Z9 9 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD AUG 7 PY 1991 VL 87 IS 15 BP 2383 EP 2389 DI 10.1039/ft9918702383 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FZ695 UT WOS:A1991FZ69500015 ER PT J AU PARNAS, RS COHEN, Y AF PARNAS, RS COHEN, Y TI RESPONSE OF A TERMINALLY ANCHORED POLYMER-CHAIN TO SIMPLE SHEAR-FLOW SO MACROMOLECULES LA English DT Article ID ADSORBED POLYMER; KINETIC-THEORY; DYNAMICS; CONFORMATION; THICKNESS; RHEOLOGY; MODELS AB The behavior of a terminally anchored, freely jointed bead-rod chain subjected to uniform solvent shear flow was investigated via Brownian dynamics simulations. The effects of solvent flow were demonstrated through the dependence of the segment density distributions, components of the radius of gyration, and the attachment force on the solvent shear rate. Additionally, it was found that the effective hydrodynamic thickness was a strong function of the shear rate, in contrast to previous results for bead-spring model chains. Stationary statistical results obtained for the chain extension show two regimes in the configuration space of the model chain, a Brownian regime at low shear rates and a hydrodynamic regime at high shear rates. C1 UNIV CALIF LOS ANGELES,DEPT CHEM ENGN,LOS ANGELES,CA 90024. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. OI Cohen, Yoram/0000-0002-0756-4699 NR 49 TC 31 Z9 31 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 5 PY 1991 VL 24 IS 16 BP 4646 EP 4656 DI 10.1021/ma00016a027 PG 11 WC Polymer Science SC Polymer Science GA GA151 UT WOS:A1991GA15100027 ER PT J AU JIA, JJ OBRIEN, WL CALLCOTT, TA DONG, QY RUBENSSON, JE MUELLER, DR EDERER, DL AF JIA, JJ OBRIEN, WL CALLCOTT, TA DONG, QY RUBENSSON, JE MUELLER, DR EDERER, DL TI SOFT-X-RAY-EMISSION SPECTRA OF SOLID KR AND XE SO PHYSICAL REVIEW LETTERS LA English DT Article ID RARE-GASES; XENON; PHOTOEMISSION; KRYPTON; BANDS; ELECTRON; VALENCE AB We present the first soft-x-ray-emission spectra for solid Kr (4p-3d) and Xe (5p-4d) that are free of complicating satellite spectra. Monochromatic synchrotron-radiation excitation is used to suppress the satellites. The data are analyzed to determine the P3/2 bandwidth for both elements; these results are compared with both photoemission data and available theoretical calculations. Bandwidths are found to be larger than those predicted by most electronic structure calculations. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP JIA, JJ (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 23 TC 7 Z9 7 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 AUG 5 PY 1991 VL 67 IS 6 BP 731 EP 734 DI 10.1103/PhysRevLett.67.731 PG 4 WC Physics, Multidisciplinary SC Physics GA FZ348 UT WOS:A1991FZ34800019 ER PT J AU BENDERSKY, LA BOETTINGER, WJ ROYTBURD, A AF BENDERSKY, LA BOETTINGER, WJ ROYTBURD, A TI COHERENT PRECIPITATES IN THE BCC ORTHORHOMBIC 2-PHASE FIELD OF THE TI-AL-NB SYSTEM SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID ALLOYS AB Alloys of composition Ti2AlNb and Ti4AlNb3, cooled from 1400-degrees-C and equilibrated at 700-degrees-C for 26 days, were both found to consist of two phases: the Ti- and Nb-rich b.c.c. phase and the orthorhombic phase based on Ti2AlNb. Depending on the alloy composition, each phase was observed as a precipitate with a plate morphology in the matrix of the other phase. In both cases the phases share a common direction, [011]b.c.c. parallel-to [001]ort, and interface (habit) plane, (211BAR)b.c.c. parallel-to (110BAR)ort. Geometrical patterns of plates of the different orientational variants were also observed. Analysis of the orientation relation, habit plane and plate patterns are consistent with the concept of a strain-type transition even though long range diffusion is required. RP BENDERSKY, LA (reprint author), NATL INST STAND & TECHNOL, DIV MET, GAITHERSBURG, MD 20899 USA. NR 24 TC 62 Z9 62 U1 1 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD AUG PY 1991 VL 39 IS 8 BP 1959 EP 1969 DI 10.1016/0956-7151(91)90165-W PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA FY829 UT WOS:A1991FY82900025 ER PT J AU RUMBLE, J AF RUMBLE, J TI NIST CARB BIOLOGICAL MACROMOLECULE CRYSTALLIZATION DATABASE SO AMERICAN LABORATORY LA English DT Article RP RUMBLE, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD AUG PY 1991 VL 23 IS 12 BP 33 EP 33 PG 1 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA GA348 UT WOS:A1991GA34800006 ER PT J AU TURK, GC AF TURK, GC TI SINGLE-RESONANCE AND DOUBLE-RESONANCE LASER-INDUCED IONIZATION OF PHOSPHORUS MONOXIDE IN AN AIR ACETYLENE FLAME FOR THE DETERMINATION OF PHOSPHORUS SO ANALYTICAL CHEMISTRY LA English DT Article ID ENHANCED IONIZATION; 2-PHOTON IONIZATION; SPECTROMETRY; SPECTROSCOPY; PO; SPECTRA; STATES AB Laser-induced ionization of phosphorus monoxide in an air-acetylene flame has been investigated as a technique for the determination of phosphorus in aspirated solutions. Two approaches to laser-induced ionization were used-resonantly enhanced multiphoton ionization (REMPI) using B-X transitions between 319 and 325 nm and double-resonance laser-enhanced ionization (LEI) using the B2-SIGMA+-X2-PI-r transition together with D2-PI-r-B2-SIGMA+ or D'2-PI-r-B2-SIGMA+ transitions between 556 and 565 nm. The best limits of detection for P are 200 ng/mL using REMPI and 30 ng/mL using double-resonance LEI. Selectivity for P in various metal matrices was studied, showing severe selectivity problems using the REMPI approach and significant improvements by LEI. RP TURK, GC (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 21 TC 8 Z9 8 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1991 VL 63 IS 15 BP 1607 EP 1611 DI 10.1021/ac00015a021 PG 5 WC Chemistry, Analytical SC Chemistry GA FY568 UT WOS:A1991FY56800023 ER PT J AU EPPELDAUER, G HARDIS, JE AF EPPELDAUER, G HARDIS, JE TI 14-DECADE PHOTOCURRENT MEASUREMENTS WITH LARGE-AREA SILICON PHOTODIODES AT ROOM-TEMPERATURE SO APPLIED OPTICS LA English DT Article DE BANDWIDTH; DYNAMIC RANGE; NOISE; OPTICAL DETECTION; PHOTODIODE; PHOTONICS; RADIOMETRY; SENSITIVITY ID LINEARITY AB Recent improvements in commercial silicon photodiodes and operational amplifiers permit electrical noise to be reduced to an equivalent of 0.1 fA of photocurrent when a measurement time of 400 s is used. This is equivalent to a photocurrent resulting from fewer than 800 photons/s, and it implies a dynamic range of 14 orders of magnitude for a detector circuit. We explain the circuit theory, paying particular attention to the measurement bandwidth, the causes of noise and drift, and the proper selection of circuit components. These optical radiation detectors complement the primary radiometric standards. These detectors may replace photomultiplier tubes that have been used traditionally and or that were too costly to be used. RP EPPELDAUER, G (reprint author), NATL INST STAND & TECHNOL,DIV RADIOMETR PHYS,GAITHERSBURG,MD 20899, USA. NR 21 TC 45 Z9 47 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1991 VL 30 IS 22 BP 3091 EP 3099 PG 9 WC Optics SC Optics GA FY055 UT WOS:A1991FY05500003 PM 20706359 ER PT J AU CAO, LX VORBURGER, TV LIEBERMAN, AG LETTIERI, TR AF CAO, LX VORBURGER, TV LIEBERMAN, AG LETTIERI, TR TI LIGHT-SCATTERING MEASUREMENT OF THE RMS SLOPES OF ROUGH SURFACES SO APPLIED OPTICS LA English DT Article DE LIGHT SCATTERING; OPTICAL METROLOGY; ROUGHNESS; SCATTERING; SURFACE FINISH; SURFACE ROUGHNESS; SURFACES; TEXTURE ID LASER AB Angle-resolved light scattering (ARLS) is used to estimate the root-mean-square (rms) slopes of rough surfaces having a well-defined lay, and the effect on slope measurements caused by changing the angles of incidence and scattering is investigated. The ARLS patterns are taken with the Detector Array for Laser Light Angular Scattering (Dallas) research instrument, and the rms slopes are obtained from the angular widths of these patterns. In general, it was found that the angular width, and thus the estimated rms slope, is surprisingly insensitive to relatively large changes in both the incident and scattering angles of light. These results are independent of surface material and are valid for both sinusoidal and random rough surfaces with lay. The principles, experiments, analyses, and conclusions involved in using ARLS to estimate rms surface slopes are described. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RP CAO, LX (reprint author), NORTHWESTERN POLYTECH UNIV,DEPT AIRCRAFT MFG,XIAN,PEOPLES R CHINA. NR 13 TC 30 Z9 33 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1991 VL 30 IS 22 BP 3221 EP 3227 PG 7 WC Optics SC Optics GA FY055 UT WOS:A1991FY05500022 PM 20706378 ER PT J AU WYSS, M AF WYSS, M TI REPORTING HISTORY OF THE CENTRAL ALEUTIANS SEISMOGRAPH NETWORK AND THE QUIESCENCE PRECEDING THE 1986 ANDREANOF ISLAND EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID PRECURSORY SEISMIC QUIESCENCE; CALIFORNIA; CONSISTENCY; HAWAII; RATES; ARC AB The earthquake catalog of the Central Aleutian Seismic Network (CASN) was searched systematically for significant rate changes in the period from 1976 through 1985. The magnitude signatures for the nine changes were modeled by synthetic signatures. By this method, six of the rate changes could be identified as artificial, based on the criteria that the rate change was confined to small magnitude events and that magnitude shifts were present. For each of these changes an artificial cause existed that affected the network within one to two months of the time of change as estimated from the catalog analysis. One of these cases was a rate decrease by a factor of 2 associated with a storm that had put out of operation two thirds of the network. Another change coincided with the introduction of digital data processing. The four remaining cases were artificial reporting rate increases due to installation of several new stations or to repair of several stations that had failed. The three rate changes that could not be identified unambiguously as artificial or natural on the basis of magnitude signatures were all rate decreases by factors of approximately 2. Two of these were clearly due to disasters that had put out of operation more than half of the network. The third was the proposed precursory quiescence to the 1986 Andreanof island (M = 7.9) earthquake. From this we conclude that, without knowledge of the network history, many of the artificial reporting rate changes in earthquake catalogs can be identified as artificial and that their onset time can be estimated to within one to two months. An earthquake count, independent from the Adak catalog, was obtained from the Helicorder records of the station Adak for the years 1978 through 1985 for the vicinity of Adak island. Of a total of 1831 events, 335 were not in the Adak catalog and 981 were located within the 1986 aftershock area. The Helicorder earthquake count showed a pronounced decrease by about 50 per cent, similar in amount to that in the Adak catalog. However, the decrease started in 1980, at a time when in the central subregion covered by the Adak catalog only M greater-than-or-equal-to 2.9 events decreased, while the smaller magnitude bands show a maximum decrease in 1982. We conclude that the possibility could not be ruled out that electronics changes contributed to the reporting rate decrease starting in the years 1980 to 1982. However, it seems very unlikely that a network that was at its healthiest during the precursor time would be reduced by an improvement in the electronics to a detection level approximately equal to that in two short periods when only one third of the stations were operating. Therefore, the seismic quiescence reported and interpreted as a precursor by Kisslinger et al. (1985) was most likely a natural phenomenon. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 16 TC 35 Z9 35 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1991 VL 81 IS 4 BP 1231 EP 1254 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FZ501 UT WOS:A1991FZ50100011 ER PT J AU HOLASEK, RE ROSE, WI AF HOLASEK, RE ROSE, WI TI ANATOMY OF 1986 AUGUSTINE VOLCANO ERUPTIONS AS RECORDED BY MULTISPECTRAL IMAGE-PROCESSING OF DIGITAL AVHRR WEATHER-SATELLITE DATA SO BULLETIN OF VOLCANOLOGY LA English DT Article AB Eighteen digital AVHRR (advanced very high resolution radiometer) data sets from NOAA-6 and NOAA-9 polar-orbiting satellites recorded between 27 March and 7 April 1986 depict the eruptive activity of Augustine volcano, located 280 km SW of Anchorage, Alaska. The synoptic view (resolution of either 1.1 or 4.4 km), frequent coverage (often twice a day), and multispectral coverage (five bands: 0.58-0.68; 0.72-1.1; 3.55-3.93; 10.5-11.3; and 11.5-12.5-mu-m) makes the AVHRR broadly applicable to analyzing explosive eruption clouds. The small scale of the Augustine activity (column heights of 2-13 km and eruption rates of 2 x 10(6)-8 x 10(7) metric tonnes/day) facilitated intensive multispectral study because the plumes generally covered areas within the 550 x 550 km area of one easily manipulated image field. Hourly ground weather data and twice-daily radiosonde measurements from stations surrounding the volcano plus numerous volcano-logical observations were made throughout the eruption, providing important ground truth with which to calibrate the satellite data. The total erupted volume is estimated to be at least 0.102 km3. The pattern of changing eruption rates determined by satellite observations generally correlate with more detailed estimates of explosion magnitudes. Multispectral processing techniques were used to distinguish eruption clouds from meteorological clouds. Variable weather during the Augustine eruption offered an opportunity to test various trial algorithms. A ratio between thermal IR channels four and five, served to delineate the ashbearing eruption plumes from ordinary clouds. Future work is needed to determine whether the successful multispectral discrimination is caused by wavelength-dependent variable emission of silicate ash or reflects a spectral role of sulfuric acid aerosol in the plume. RP HOLASEK, RE (reprint author), NOAA,CTR CLIMATE ANAL,CAMP SPRINGS,MD 20746, USA. RI Rose, William/A-7923-2009 NR 0 TC 51 Z9 51 U1 1 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD AUG PY 1991 VL 53 IS 6 BP 420 EP 435 DI 10.1007/BF00258183 PG 16 WC Geosciences, Multidisciplinary SC Geology GA GA682 UT WOS:A1991GA68200002 ER PT J AU NALEPA, TF AF NALEPA, TF TI STATUS AND TRENDS OF THE LAKE-ONTARIO MACROBENTHOS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID STYLODRILUS-HERINGIANUS LUMBRICULIDAE; NIAGARA RIVER; ORGANOCHLORINE CONTAMINANTS; BENTHIC MACROINVERTEBRATES; ENVIRONMENTAL-FACTORS; RELATIVE TOLERANCES; SUBLETHAL RESPONSES; SURFICIAL SEDIMENTS; PONTOPOREIA-HOYI; WESTERN BASIN AB The benthic macroinvertebrate community of Lake Ontario was examined relative to communities found in the other Great Lakes and also relative to trends over time. In the nearshore, populations are heavily influenced by municipal and industrial inputs. For example, oligochaete abundances in the nearshore are higher than in any of the other Great Lakes (excluding shallow Lake Erie), communities have been altered even to relatively deep depths near the major river mouths, and the pollution-sensitive Pontoporeia hoyi is scarce along the southern shoreline east of the Niagara River mouth. In the profundal, benthic composition is similar to that found in the other Great Lakes, but biomass is less than might be expected given the amount of organic material settling to the bottom. Benthic standing stocks in this region have apparently declined almost threefold since the 1960s. Reasons for this decline do not appear to be related to trends in water column productivity or to predation pressure, but may be related to the accumulation of contaminants. Research needs include studies to assess benthic trends over a much broader area of the lake and studies to examine the impact of sublethal levels of contaminants. RP NALEPA, TF (reprint author), GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 88 TC 27 Z9 27 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 1991 VL 48 IS 8 BP 1558 EP 1567 DI 10.1139/f91-184 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GC707 UT WOS:A1991GC70700024 ER PT J AU HARTIG, JH KITCHELL, JF SCAVIA, D BRANDT, SB AF HARTIG, JH KITCHELL, JF SCAVIA, D BRANDT, SB TI REHABILITATION OF LAKE-ONTARIO - THE ROLE OF NUTRIENT REDUCTION AND FOOD WEB DYNAMICS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID WATER-QUALITY; MICHIGAN; PHYTOPLANKTON; PREDATION; MODEL; LOAD AB The Laurentian Great Lakes have a complex history of changes due to eutrophication, invasion of exotic species, and fisheries and phosphorus management practices. Remedial actions have reduced nutrient loadings and enhanced the role of food web interactions in improving water quality. Workshops sponsored through the United States - Canada international Joint Commission have addressed the relative importance of nutrient abatement and/or food web manipulation in affecting water quality trends. Both controls have combined to enhance water clarity in Lake Michigan. Lake Ontario has already exhibited the effects of nutrient controls and may be on the verge of manifesting food web controls. Research and monitoring recommendations to elucidate the effects of nutrient and food web controls include the following: (1) water quality and fisheries agencies must coordinate monitoring activities, standardize techniques, and establish and maintain long-term data sets to evaluate the effects of water quality and fisheries programs separately and together; (2) controlled, mesoscale, whole-system experiments should be performed to quantify rates (e.g. growth, predation, etc.) of food web interactions; and (3) the scientific community should promote research which quantifies the impact of changes in food web dynamics on changes in toxic substance levels in Great Lakes fishes. C1 UNIV WISCONSIN,CTR LIMNOL,MADISON,WI 53706. NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. UNIV MARYLAND,CHESAPEAKE BIOL LAB,SOLOMONS,MD 20688. RP HARTIG, JH (reprint author), INT JOINT COMMISS,GREAT LAKES REG OFF,100 OUELLETTE AVE,WINDSOR N9A 6T3,ONTARIO,CANADA. OI Scavia, Donald/0000-0002-2784-8269 NR 24 TC 25 Z9 26 U1 2 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 1991 VL 48 IS 8 BP 1574 EP 1580 DI 10.1139/f91-186 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA GC707 UT WOS:A1991GC70700026 ER PT J AU KOMHYR, WD OLTMANS, SJ GRASS, RD LEONARD, RK AF KOMHYR, WD OLTMANS, SJ GRASS, RD LEONARD, RK TI POSSIBLE INFLUENCE OF LONG-TERM SEA-SURFACE TEMPERATURE ANOMALIES IN THE TROPICAL PACIFIC ON GLOBAL OZONE SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID QUASI-BIENNIAL OSCILLATION; GROUND-BASED OBSERVATIONS; ANTARCTIC OZONE; NORTHERN-HEMISPHERE; ATMOSPHERIC OZONE; SOUTH-POLE; DEPLETION; STRATOSPHERE; DESTRUCTION; CIRCULATION AB A significant negative correlation exists between June-August sea surface temperatures (SSTs) in the eastern equatorial Pacific and 15-31 October total ozone values at South Pole, Antarctica. SSTs in the eastern equatorial Pacific were anomalously warmer by 0.67-degrees-C during 1976-1987 compared with 1962-1975. Quasi-biennial oscillation (QBO) easterly winds in the equatorial Pacific stratosphere were generally stronger after 1975 than they were before that time. Prior to the early-to-mid 1970s the trend in global ozone was generally upward, but then turned downward. Total ozone at Hawaii and Samoa, which had been decreasing at a rate of about 0.35% yr-1 during 1976-1987, showed recovery to mid-1970s values in 1988-1989 following a drop in SSTs in the eastern equatorial Pacific to low values last observed there prior to 1976. During 15-31 October 1988, total ozone at South Pole, which had decreased from about 280 Dobson units (DU) prior to 1980 to 140 DU in 1987, suddenly recovered to 250 DU, though substantial ozone depletion by heterogeneous photochemical processes involving polar stratospheric clouds was still evident in the South Pole ozone vertical profiles. These observations suggest that the downward trend in ozone observed over the globe in recent years may have been at least partially meteorologically induced, possibly through modulation by the warmer tropical Pacific ocean waters of QBO easterly winds at the equator, of planetary waves in the extratropics, of the interaction of QBO winds and planetary waves, and of Hadley Cell circulation. A cursory analysis of geostrophic wind flow around the Baffin Island low suggests a meteorological influence on the observed downward trend in ozone over North America during the past decade. Because ozone has a lifetime that varies from minutes to hours in the primary ozone production region at high altitudes in the tropical stratosphere to months and years in the low stratosphere, changes in atmospheric dynamics have the potential for not only redistributing ozone over the globe, but also changing global ozone abundance. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP KOMHYR, WD (reprint author), ATMOSPHER ADM,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303, USA. NR 47 TC 8 Z9 8 U1 0 U2 1 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD AUG-SEP PY 1991 VL 69 IS 8-9 BP 1093 EP 1102 PG 10 WC Physics, Multidisciplinary SC Physics GA GR975 UT WOS:A1991GR97500025 ER PT J AU HAMINS, A KLASSEN, M GORE, J KASHIWAGI, T AF HAMINS, A KLASSEN, M GORE, J KASHIWAGI, T TI ESTIMATE OF FLAME RADIANCE VIA A SINGLE LOCATION MEASUREMENT IN LIQUID POOL FIRES SO COMBUSTION AND FLAME LA English DT Article ID TURBULENT-DIFFUSION FLAMES; THERMAL-RADIATION AB A method for estimating the radiative heat loss fraction (chi-R), the ratio of the flame energy radiated to the surroundings to the idealized combustion heat release, is developed for pool fires. Experimental investigation of small to medium sized pool fires (4.6-30 cm) shows that a radiance measurement made at a single location and corrected for anisotropic effects yields an estimate of chi-R that is within 13% of the multilocation measurement of chi-R. Eight fuels were tested, with heat release rates of 0.6-120 kW and values of chi-R from 0.16 to 0.35. A previously proposed rule for finding chi-R from one-location radiance measurements was also tested and works reasonably well for nonluminous alchol flames. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. RP HAMINS, A (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 18 TC 20 Z9 21 U1 1 U2 4 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 AUG PY 1991 VL 86 IS 3 BP 223 EP 228 DI 10.1016/0010-2180(91)90102-H PG 6 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA GF137 UT WOS:A1991GF13700004 ER PT J AU CROLL, DA OSMEK, SD BENGTSON, JL AF CROLL, DA OSMEK, SD BENGTSON, JL TI AN EFFECT OF INSTRUMENT ATTACHMENT ON FORAGING TRIP DURATION IN CHINSTRAP PENGUINS SO CONDOR LA English DT Note DE PENGUIN; SEABIRD; RECORDER; BEHAVIOR; FORAGING; RADIO TRANSMITTER ID BEHAVIOR RP CROLL, DA (reprint author), NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 12 TC 45 Z9 45 U1 2 U2 3 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 SN 0010-5422 J9 CONDOR JI Condor PD AUG PY 1991 VL 93 IS 3 BP 777 EP 779 DI 10.2307/1368216 PG 3 WC Ornithology SC Zoology GA GG626 UT WOS:A1991GG62600038 ER PT J AU SMITH, PC SCHWING, FB AF SMITH, PC SCHWING, FB TI MEAN CIRCULATION AND VARIABILITY ON THE EASTERN CANADIAN CONTINENTAL-SHELF SO CONTINENTAL SHELF RESEARCH LA English DT Article; Proceedings Paper CT CANADIAN CONTINENTAL SHELF SEABED SYMP CY OCT 02-07, 1989 CL BEDFORD INST OCEANOG, DARTMOUTH, CANADA SP BEDFORD INST OCEANOG HO BEDFORD INST OCEANOG ID MIDDLE ATLANTIC BIGHT; SCOTIAN SHELF; NOVA-SCOTIA; INERTIAL OSCILLATIONS; SEDIMENT TRANSPORT; TOPOGRAPHIC DRAG; TIDAL CURRENTS; LABRADOR SHELF; SLOPE WATERS; SIMPLE-MODEL AB The circulation and variability on eastern Canadian continental shelves is reviewed with emphasis on horizontal and vertical structure in the water column. Mean and seasonal currents, sheared by stratification and friction. generally follow bathymetry and are driven primarily by surface wind stress and buoyancy fluxes. In certain near-resonant embayments, nonlinear interactions of the tide also make significant contributions to the mean and low-frequency currents. Direct forcing of low-frequency shelf circulation by offshore currents and pressure fields is of lesser importance according to recent observations and models. At higher frequencies, the wintertime response to atmospheric forcing occurs in three important frequency bands: surface wave (periods of 2-20 s), inertial (17-22 h) and synoptic or subtidal (2-10 days). Most of the subtidal energy in the subsurface pressure (SSP) field is attributable to direct local forcing by alongshore wind and to remote forcing by coastal-trapped waves (CTW). The subtidal current variability is less coherent with these sources primarily because of small scale circulations created by vortex stretching, topographic steering and scattering by the rugged shelf bathymetry. Bottom friction and scattering control the ratio of locally and remotely forced subtidal energy as a function of position on the shelf. Intermittent inertial currents in stratified shelf waters. often associated with mesoscale atmospheric forcing, exhibit a 180-degrees phase change across the pycnocline and are inhibited near the coast. Surface waves generated by storm winds are strongly dissipated in shallow water, where they enhance bottom stresses that: (1) balance the surface wind stress; and (2) may contribute to the damping of inertial waves. Specific examples of these phenomena are drawn from observations on the Scotian Shelf and in the Gulf of Maine. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,PACIFIC FISHERIES ENVIRONM GRP,MONTEREY,CA. RP SMITH, PC (reprint author), FISHERIES & OCEANS CANADA,BEDFORD INST OCEANOG,DEPT FISHERIES & OCEANS,DARTMOUTH B2Y 4A2,NS,CANADA. NR 75 TC 52 Z9 52 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG-OCT PY 1991 VL 11 IS 8-10 BP 977 EP 1012 DI 10.1016/0278-4343(91)90088-N PG 36 WC Oceanography SC Oceanography GA GN704 UT WOS:A1991GN70400017 ER PT J AU GOODRICH, LF AF GOODRICH, LF TI HIGH-TC SUPERCONDUCTOR VOLTAGE CURRENT SIMULATOR AND THE PULSE METHOD OF MEASURING CRITICAL CURRENT SO CRYOGENICS LA English DT Article DE HIGH TC SUPERCONDUCTORS; CRITICAL CURRENTS; MEASURING METHODS ID YBA2CU3OX AB A passive voltage-current (V - I) simulator has been developed and tested using conventional direct current (d.c.) and pulse current methods. The simulator was designed to generate the extremely non-linear V - I characteristic of a superconductor and has a similar power-law behaviour. It is intended to be used to test various components of the measurement system such as instrumentation, measurement method and data analysis software, to determine the transport critical current, I(c), or critical current density, J(c), of a superconductor. This simulator does not emulate all the subtle effects of flux flow in a superconductor. However, it approximates a superconductor's major static and dynamic electrical characteristics. The simulator is therefore a necessary but incomplete test of a measurement system. Critical currents obtained on the simulator using the pulse and d.c. methods are compared and show close agreement. Also, preliminary comparisons of methods using bulk and thin film YBCO samples are given. RP GOODRICH, LF (reprint author), NATL INST STAND & TECHNOL,CTR ELECTR & ELECT ENGN,BOULDER,CO 80303, USA. NR 11 TC 13 Z9 13 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD AUG PY 1991 VL 31 IS 8 BP 720 EP 727 DI 10.1016/0011-2275(91)90234-N PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA FZ755 UT WOS:A1991FZ75500005 ER PT J AU WALKER, RJ MORGAN, JW NALDRETT, AJ LI, C FASSETT, JD AF WALKER, RJ MORGAN, JW NALDRETT, AJ LI, C FASSETT, JD TI RE-OS ISOTOPE SYSTEMATICS OF NI-CU SULFIDE ORES, SUDBURY IGNEOUS COMPLEX, ONTARIO - EVIDENCE FOR A MAJOR CRUSTAL COMPONENT SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID IONIZATION MASS-SPECTROMETRY; OSMIUM; RHENIUM; DEPOSITS; QUANTITIES; METEORITES; EVOLUTION; ELEMENTS; SILICATE; ORIGIN AB Sudbury Igneous Complex sublayer ores from the Levack West, Falconbridge and Strathcona mines were analyzed for their Re and Os concentrations and Os isotopic compositions. The Re-Os isotope systematics of three ores from the different mines give isochron ages of 1840 +/- 60 Ma, 1770 +/- 60 Ma and 1780 +/- 110 Ma, suggesting that the Re-Os system became closed at the time of, or soon after the 1850 +/- 1 Ma crystallization age of the complex. The Os isotopic compositions of different portions of the complex at the time of crystallization varied considerably, with initial Os-187/Os-186(1850) ranging from 4.64 at Levack West to 7.55 at Strathcona. These hetergeneities require that the Os, and probably also the other platinum-group elements contained in the ores, were derived from at least two sources. In addition, the high initial Os-187/Os-186 ratios indicate that the Os was derived predominantly from ancient crust. Previous studies have suggested that the complex either crystallized from a mixture of mantle-derived basaltic melt and ancient continental crust, or was derived exclusively from the fusion of ancient continental crust resulting from a meteorite impact. Results of modelling suggest that if a contemporaneous mantle-derived basaltic melt was involved in the origin of the SIC, it likely contributed < 50% of the Os to all three ores. The large percentage of ancient crust involved in the production of the ores is most consistent with an interpretation of substantial crustal fusion resulting from meteorite impact. C1 US GEOL SURVEY,RESTON,VA 22092. UNIV TORONTO,DEPT GEOL,TORONTO M5S 1A1,ONTARIO,CANADA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP WALKER, RJ (reprint author), UNIV MARYLAND,DEPT GEOL,COLLEGE PK,MD 20742, USA. RI Li, Chusi/E-5592-2011; Walker, Richard/K-6869-2016 OI Li, Chusi/0000-0002-0426-8157; Walker, Richard/0000-0003-0348-2407 NR 44 TC 117 Z9 129 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD AUG PY 1991 VL 105 IS 4 BP 416 EP 429 DI 10.1016/0012-821X(91)90182-H PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GG289 UT WOS:A1991GG28900006 ER PT J AU RYER, CH OLLA, BL AF RYER, CH OLLA, BL TI AGONISTIC BEHAVIOR IN A SCHOOLING FISH - FORM, FUNCTION AND ONTOGENY SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE AGGRESSION; DOMINANCE; FEEDING BEHAVIOR; SCHOOLING; ONCORHYNCHUS-KETA ID SALMON ONCORHYNCHUS-KETA; SALVELINUS-ALPINUS L; ARCTIC CHARR; GROWTH; SEAWATER; ECOLOGY; ESTUARY AB Although juvenile chum salmon, Oncorhynchus keta, are generally regarded as a schooling fish, when presented with a defensible point-source of food, some individuals abandon schooling, aggressively subordinate competitors, and monopolize food. When food is removed, fish gradually abandon solitary agonistic behaviors and return to schooling behavior. Agonism increases in frequency and intensity as juveniles age. The ability to alternate facultatively between schooling and solitary agonistic behavior may enable juvenile chum to respond to local patterns of food distribution and predation risk. The ontogenetic increase in agonism may result in school dispersal as fish move from the estuary into coastal waters, and may well reflect a shift in the costs versus the benefits of schooling as fish mature and become less vulnerable to predation. C1 NOAA,NATL MARINE FISHERIES SERV,COOPERAT INST MARINE RES STUDIES,ALASKA FISHERIES SCI CTR,NEWPORT,OR 97365. RP RYER, CH (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. NR 25 TC 37 Z9 37 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 AUG PY 1991 VL 31 IS 4 BP 355 EP 363 DI 10.1007/BF00002360 PG 9 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA FZ063 UT WOS:A1991FZ06300005 ER PT J AU WAPLES, RS AF WAPLES, RS TI HETEROZYGOSITY AND LIFE-HISTORY VARIATION IN BONY FISHES - AN ALTERNATIVE VIEW SO EVOLUTION LA English DT Note DE BONY FISHES; CORRELATION; ENVIRONMENTAL VARIABILITY; GENETIC VARIATION; HETEROZYGOSITY; LIFE-HISTORY TRAITS ID GENETIC-VARIABILITY RP WAPLES, RS (reprint author), NATL MARINE FISHERIES SERV,NW FISHERIES CTR,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. RI Waples, Robin/K-1126-2016 NR 18 TC 9 Z9 10 U1 0 U2 1 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD AUG PY 1991 VL 45 IS 5 BP 1275 EP 1280 DI 10.2307/2409733 PG 6 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA GC862 UT WOS:A1991GC86200018 ER PT J AU LOWE, SA FUJIOKA, JT TERRY, JM AF LOWE, SA FUJIOKA, JT TERRY, JM TI BIOECONOMIC ANALYSIS OF A MINIMUM SIZE LIMIT FOR GULF-OF-ALASKA SABLEFISH USING A YIELD PER RECRUIT MODEL SO FISHERIES RESEARCH LA English DT Article; Proceedings Paper CT SYMP AT THE 119TH ANNUAL MEETING OF THE AMERICAN FISHERIES SOC - FISH POPULATION DYNAMICS - SOLVING FISHERY MANAGEMENT PROBLEMS CY SEP, 1989 CL ANCHORAGE, AK SP AMER FISHERIES SOC AB To evaluate the potential of increasing yield in the Gulf of Alaska sablefish (Anoplopoma fimbria) fishery with a minimum size limit, a modified yield per recruit analysis was used to explore trends in yield, equilibrium biomass, reproductive potential, and economic value. The Gulf of Alaska sablefish catch quotas are apportioned to the fixed- and trawl-gear fisheries in the approximate amounts of 86.1% and 13.9%, respectively. The traditional yield per recruit model was modified to incorporate age-specific selectivity rates for each gear type and to compute yield from the combination of the two fisheries. The model also incorporated a discard mortality on undersized fish. With no discard mortality, yield per recruit increases with increasing size limits. However, the increases are significant only at high fishing mortality rates (greater than 0.20). With discard mortality, yields decrease with increasing size limits. Equilibrium biomass and the egg production index increase with increasing size limits, both with and without discard mortality, but the increases are negligible with discard mortality. The effects of a minimum size limit on gross and net value are similar to those on yield, with and without discard mortality, except that the fishing mortality rates that maximize net value are substantially less than those that maximize yield and gross value. As the fishing mortality rate for Gulf of Alaska sablefish is low (0.13), it was concluded that minimum size limits would be ineffective and could even be a detriment because of discard mortality. RP LOWE, SA (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,RESOURCE ECOL & FISHERIES MANAGEMENT,SEATTLE,WA 98115, USA. NR 0 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD AUG PY 1991 VL 11 IS 3-4 BP 307 EP 320 DI 10.1016/0165-7836(91)90007-3 PG 14 WC Fisheries SC Fisheries GA GD734 UT WOS:A1991GD73400007 ER PT J AU MEGREY, BA AF MEGREY, BA TI POPULATION-DYNAMICS AND MANAGEMENT OF WALLEYE POLLOCK (THERAGRA-CHALCOGRAMMA) IN THE GULF-OF-ALASKA, 1976-1986 SO FISHERIES RESEARCH LA English DT Article; Proceedings Paper CT SYMP AT THE 119TH ANNUAL MEETING OF THE AMERICAN FISHERIES SOC - FISH POPULATION DYNAMICS - SOLVING FISHERY MANAGEMENT PROBLEMS CY SEP, 1989 CL ANCHORAGE, AK SP AMER FISHERIES SOC AB Information from resource assessment surveys and commercial fisheries statistics was used to investigate the population dynamics of Gulf of Alaska walleye pollock (Theragra chalcogramma) from 1976 to 1986. Stock assessment analyses were used to estimate historical stock size, rates of fishing and numbers of recruits. Three different age-structured stock assessment models were fitted to two data sets: a nonlinear log catch model calibrated with fishery-independent population biomass estimates, a nonlinear catch/effort model, and a linear model based on catch per unit of effort. Variances of parameter estimates were obtained when possible. Results indicate that (1) a shift in selectivity-at-age occurred between the 1976-1981 and 1982-1986 periods; (2) population biomass was 1 000 000 t in 1976, peaked at 2 500 000 t in 1981-1982 and dropped to 400 000 t in 1986; and (3) annual changes in biomass were influenced mainly by five consecutive strong year classes (1975-1979) moving into the fishery followed by four weak year classes (1980-1983). The decline in abundance is supported by independent biomass estimates from hydroacoustic/midwater trawl surveys. Results from different catch-at-age models compare favorably with respect to estimated trends in abundance. Differences in scale are attributed to the data set, the choice of the model, and the way the models were constrained. Estimates of instantaneous natural mortality (M year-1) ranged from 0.35 to 0.50 from stock assessment methods and from 0.23 to 0.44 from empirical and approximate methods. Catchability estimates ranged from 0.014 (M = 0.42) to 0.0191 (M = 0.35). It also appears that catchability varies interannually and may be density dependent. A Ricker spawner-recruit model explained 83.5% of the variation in recruit abundance, indicating that density-dependent processes may be important in pollock population dynamics. RP MEGREY, BA (reprint author), NOAA,NATL MARINE FISHERIES SERV,US DEPT COMMERCE,SEATTLE,WA 98115, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD AUG PY 1991 VL 11 IS 3-4 BP 321 EP 354 DI 10.1016/0165-7836(91)90008-4 PG 34 WC Fisheries SC Fisheries GA GD734 UT WOS:A1991GD73400008 ER PT J AU HEIFETZ, J FUJIOKA, JT AF HEIFETZ, J FUJIOKA, JT TI MOVEMENT DYNAMICS OF TAGGED SABLEFISH IN THE NORTHEASTERN PACIFIC SO FISHERIES RESEARCH LA English DT Article; Proceedings Paper CT SYMP AT THE 119TH ANNUAL MEETING OF THE AMERICAN FISHERIES SOC - FISH POPULATION DYNAMICS - SOLVING FISHERY MANAGEMENT PROBLEMS CY SEP, 1989 CL ANCHORAGE, AK SP AMER FISHERIES SOC AB We used a Markov model to quantify movement rates of tagged sablefish (Anoplopoma fimbria) among regulatory areas of the North Pacific Fishery Management Council during 1979-1987. The model included natural and fishing mortality, tag reporting and shedding rates, and movement probabilities. Maximum likelihood was used to estimate the parameters of the model. Estimated annual movement rates out of an area were in the range 19-69% for small (less than 57 cm fork length (FL)), 25-72% for medium (57-66 cm FL), and 27-71% for large (more than 66 cm FL) sablefish. The predominant direction of movement along the continental slope was eastward for large sablefish and westward for small sablefish. Most estimates of movement rates were precise, unconfounded, and robust to perturbations of input constants (natural and fishing mortality, and tag reporting rates), except for some imprecise estimates of large sablefish. The results indicate that movement plays an important role in determining the amount of sablefish available for harvest in an area. To account for the interactions among fisheries in different areas, the movement dynamics of sablefish should be incorporated into a stock assessment based on size or age-structure. RP HEIFETZ, J (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,11305 GLACIER HIGHWAY,JUNEAU,AK 99801, USA. NR 0 TC 28 Z9 29 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD AUG PY 1991 VL 11 IS 3-4 BP 355 EP 374 DI 10.1016/0165-7836(91)90009-5 PG 20 WC Fisheries SC Fisheries GA GD734 UT WOS:A1991GD73400009 ER PT J AU EMBLEY, RW CHADWICK, W PERFIT, MR BAKER, ET AF EMBLEY, RW CHADWICK, W PERFIT, MR BAKER, ET TI GEOLOGY OF THE NORTHERN CLEFT SEGMENT, JUAN DE FUCA RIDGE - RECENT LAVA FLOWS, SEA-FLOOR SPREADING, AND THE FORMATION OF MEGAPLUMES SO GEOLOGY LA English DT Article ID ABYSSAL LAVAS; MARC-I; CENTERS; RIFT AB Geologic mapping and lava sampling were carried out after the discovery of large bursts of hydrothermal fluids (megaplumes) over the southern Juan de Fuca Ridge in 1986 and 1987. Our investigations of the northermost section of the Cleft segment have discovered: (1) semicontinuous low-temperature venting and one major high-temperature vent site along 17 km of the neovolcanic zone and (2) very glassy, lightly sedimented sheet flows and pillow mounds superimposed on older terrain over about 24 km along the northern-most part. The pillow mounds are documented to have erupted between 1981 and 1987. The occurrence of the megaplumes during this same time period strengthens the hypothesis that megaplumes are caused by sea-floor extension events. Although the basalts from the entire length of the neovolcanic zone of the Cleft segment appear to have been derived from the same mantle source, a systematic northward increase in Mg number along the segment within the neovolcanic zone indicates less shallow-level differentiation to the north, possibly related to the development of new magma chambers during the recent phase of sea-floor spreading that has occurred there. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. OREGON STATE UNIV,HATFIELD MARINE SCI CTR,CIMRS,NEWPORT,OR 97365. UNIV FLORIDA,DEPT GEOL,GAINESVILLE,FL 32611. RP EMBLEY, RW (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; Perfit, Michael/0000-0002-1399-8928 NR 26 TC 91 Z9 91 U1 1 U2 6 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD AUG PY 1991 VL 19 IS 8 BP 771 EP 775 DI 10.1130/0091-7613(1991)019<0771:GOTNCS>2.3.CO;2 PG 5 WC Geology SC Geology GA GA306 UT WOS:A1991GA30600001 ER PT J AU KEY, J MCLAREN, AS AF KEY, J MCLAREN, AS TI FRACTAL NATURE OF THE SEA ICE DRAFT PROFILE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The fractal dimension is examined as a descriptor of ice roughness for more than 3000 km of under-ice draft submarine sonar data. The data can be considered to constitute a fractal set within a limited range of scales, as defined by the Hurst parameter H. It was found that 0.55 < H < 0.78 for scales of 3-15 m and 0.15 < H < 0.45 for scales of 15-75 m, beyond which H is near unity. From this it is seen quantitatively that sea ice on the large scale is smooth. The fractal dimension, D = 2 - H, at the smaller scales is similar to that measured by other investigators for individual ice features such as keels. The fractal dimension did not show any changing spatial pattern across ice regions, indicating that the scaling relationship is similar even when first-order measures such as the mean and variance of ice draft change. Therefore, D does not appear to be useful for partitioning the transect into homogeneous ice areas in the draft data examined. RP KEY, J (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI Key, Jeffrey/F-5597-2010 OI Key, Jeffrey/0000-0001-6109-3050 NR 8 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG PY 1991 VL 18 IS 8 BP 1437 EP 1440 DI 10.1029/91GL01761 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GB150 UT WOS:A1991GB15000017 ER PT J AU STRICKLETT, KL FENIMORE, C KELLEY, EF YAMASHITA, H PACE, MO BLALOCK, TV WINTENBERG, AL ALEXEFF, I AF STRICKLETT, KL FENIMORE, C KELLEY, EF YAMASHITA, H PACE, MO BLALOCK, TV WINTENBERG, AL ALEXEFF, I TI OBSERVATION OF PARTIAL DISCHARGE IN HEXANE UNDER HIGH MAGNIFICATION SO IEEE TRANSACTIONS ON ELECTRICAL INSULATION LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL CONF ON CONDUCTION AND BREAKDOWN IN DIELECTRIC LIQUIDS CY SEP 10-14, 1990 CL GRENOBLE, FRANCE SP IEEE, DIELECT & ELECT INSULAT SOC, CNRS, UNIV JOSEPH FOURIER, FRENCH ELECT BOARD, MAIRIE GRENOBLE, COUNSEIL GEN ISERE, LAB PHYS & MECH FLUIDS POITIERS ID DIVERGENT ELECTRIC-FIELD AB Partial discharges are observed in hexanes by means of shadow photography under the application of dc voltages. A non-uniform field geometry is employed and the growth of cavities associated with partial discharges at a point cathode is photographed at 200x magnification. A multi-frame photograph of the cavity and a simultaneous record of the partial-discharge current provide a detailed record of the temporal and spatial development of the discharge. Examination of these date suggest that electrostatic forces are of primary importance in driving the growth of the cavity near its inception. C1 UNIV TENNESSEE,DEPT ELECT & COMP ENGN,KNOXVILLE,TN 37996. RP STRICKLETT, KL (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 23 TC 24 Z9 24 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9367 J9 IEEE T ELECTR INSUL PD AUG PY 1991 VL 26 IS 4 BP 692 EP 698 DI 10.1109/14.83691 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA GE339 UT WOS:A1991GE33900024 ER PT J AU RANDA, J KANDA, M ORR, RD AF RANDA, J KANDA, M ORR, RD TI THERMOOPTIC DESIGNS FOR ELECTROMAGNETIC-FIELD PROBES FOR MICROWAVES AND MILLIMETER WAVES SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article ID FIBEROPTIC THERMOMETRY AB We report the development of an electromagnetic-field probe for microwave and millimeter-wave frequencies. The probe uses an optically sensed thermometer to measure the heating of a resistive element in an electromagnetic field. The response is calculated for several different configurations of the resistive element, and two optimal designs are chosen. Measurements on experimental probes of these designs are presented. One of the designs displays a flat frequency response above 30 GHz and a sensitivity of 38 V/m. We identify improvements in the design that should significantly increase the sensitivity and improve the low-frequency response. RP RANDA, J (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 19 TC 12 Z9 13 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 1991 VL 33 IS 3 BP 205 EP 214 DI 10.1109/15.85134 PG 10 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA FW970 UT WOS:A1991FW97000007 ER PT J AU TOFANI, S ONDREJKA, A KANDA, M AF TOFANI, S ONDREJKA, A KANDA, M TI A TIME-DOMAIN METHOD FOR CHARACTERIZING THE REFLECTION COEFFICIENT OF ABSORBING MATERIALS FROM 30-MHZ TO 1000-MHZ SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE ABSORBER; MICROWAVES; REFLECTIVITY; REFLECTOMETER; RF; TIME DOMAIN AB A wideband time-domain reflectometer is used to evaluate the reflection characteristics of RF/microwave absorbers. The reflectometer uses an array of two identical broad-band antennas (both transmitting and receiving). The two antennas are used in a difference mode to remove the undesired signals and enhance the small reflections being measured. Using this technique, we can separate the target surface reflections from those generated outside the target area. The bandwidth of our pulses is 30 to 1000 MHz, and the reflection coefficient is measured over this range. The method has been used to characterize the reflectivity of three different types of absorber placed in an anechoic chamber. The results are reported together with a discussion of the main sources of errors. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303. NR 15 TC 12 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 1991 VL 33 IS 3 BP 234 EP 240 DI 10.1109/15.85137 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA FW970 UT WOS:A1991FW97000010 ER PT J AU DAYWITT, WC AF DAYWITT, WC TI EXACT PRINCIPAL MODE FIELD FOR A LOSSY COAXIAL LINE SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE COAXIAL TRANSMISSION LINE; MAXWELL EQUATIONS; PRINCIPAL MODE; PROPAGATION CONSTANT; TELEGRAPHER EQUATION AB Exact field equations for a lossy coaxial transmission line with an infinite outer conductor are presented. The corresponding determinantal equation is solved to obtain an exact propagation constant from which errors in the usual microwave approximation and an alternative full frequency range approximation are calculated. The calculations show that the microwave approximation, although containing a large relative error at the lower frequencies, is still useful in practical applications. RP DAYWITT, WC (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 7 TC 12 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD AUG PY 1991 VL 39 IS 8 BP 1313 EP 1322 DI 10.1109/22.85406 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA FV890 UT WOS:A1991FV89000009 ER PT J AU GALLAGHER, KB LYLE, JR AF GALLAGHER, KB LYLE, JR TI USING PROGRAM SLICING IN SOFTWARE MAINTENANCE SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE SOFTWARE MAINTENANCE; PROGRAM SLICING; DECOMPOSITION SLICING; SOFTWARE PROCESS MODELS; SOFTWARE TESTING; SOFTWARE TOOLS; IMPACT ANALYSIS ID DATA-FLOW ANALYSIS; DEPENDENCE GRAPH AB Program slicing, introduced by Weiser, is known to help programmers in understanding foreign code and in debugging. We apply program slicing to the maintenance problem by extending the notion of a program slice (that originally required both a variable and line number) to a decomposition slice, one that captures all computation on a given variable; i.e., is independent of line numbers. Using the lattice of single variable decomposition slices ordered by set inclusion, we demonstrate how to form a slice-based decomposition for programs. We are then able to delineate the effects of a proposed change by isolating those effects in a single component of the decomposition. This gives maintainers a straightforward technique for determining those statements and variables which may be modified in a component and those which may not. Using the decomposition, we provide a set of principles to prohibit changes which will interfere with unmodified components. These semantically consistent changes can then be merged back into the original program in linear time. Moreover, the maintainer can test the changes in the component with the assurance that there are no linkages into other components. Thus decomposition slicing induces a new software maintenance process model which eliminates the need for regression testing. C1 UNIV MARYLAND,CATONSVILLE,MD 21228. NATL INST STAND & TECHNOL COMP SYST LAB,GAITHERSBURG,MD. RP GALLAGHER, KB (reprint author), LOYOLA COLL,DEPT COMP SCI,4501 N CHARLES ST,BALTIMORE,MD 21210, USA. OI Gallagher, Keith/0000-0002-1469-9866 NR 37 TC 250 Z9 259 U1 1 U2 6 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD AUG PY 1991 VL 17 IS 8 BP 751 EP 761 DI 10.1109/32.83912 PG 11 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA GD026 UT WOS:A1991GD02600002 ER PT J AU OLIVER, FW THOMAS, C HOFFMAN, E HILL, D SUTTER, TPG HAMBRIGHT, P HAYE, S THORPE, AN QUOC, N HARRIMAN, A NETA, P MOSSERI, S AF OLIVER, FW THOMAS, C HOFFMAN, E HILL, D SUTTER, TPG HAMBRIGHT, P HAYE, S THORPE, AN QUOC, N HARRIMAN, A NETA, P MOSSERI, S TI MOSSBAUER, MAGNETIC-SUSCEPTIBILITY, RADIOLYTIC AND PHOTOCHEMICAL STUDIES OF EUROPIUM AND LUTETIUM PORPHYRINS SO INORGANICA CHIMICA ACTA LA English DT Article ID WATER; REDUCTION; METAL AB The chemistry of the lanthanide complexes of europium and lutetium with several porphyrin molecules were probed in both the solid state and in solution. Mossbauer and variable temperature magnetic susceptibility studies indicated that the trivalent state of europium was formed under the synthetic conditions. Electron addition to both europium(III) and lutetium(III) porphyrins by photochemical and radiolytic techniques resulted in reduction of the porphyrin ring rather than the coordinated trivalent metal ion, and the resulting pi-radical anion disproportionated into the initial metalloporphyrin and the ring reduced metalloporphyrin di-anion. The reduction potentials in solution for mono- and di-anion formation of the lutetium porphyrin were measured by electrochemical procedures. While the lutetium(III) porphyrin is stable for years at pH 7, the metal is rapidly removed from the metalloporphyrin by protons in the di-anion state. The photophysics of the lutetium(III) porphyrin in solution are dominated by the triplet state, and the reactivity of this triplet with dioxygen, NADH and persulfate is reported. C1 HOWARD UNIV,DEPT CHEM & PHYS,WASHINGTON,DC 20059. UNIV TEXAS,CTR FAST KINET RES,AUSTIN,TX 78712. NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. RP OLIVER, FW (reprint author), MORGAN STATE UNIV,DEPT PHYS,BALTIMORE,MD 21239, USA. NR 28 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD AUG 1 PY 1991 VL 186 IS 1 BP 119 EP 124 DI 10.1016/S0020-1693(00)87940-2 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA GF058 UT WOS:A1991GF05800020 ER PT J AU FAIRALL, CW AF FAIRALL, CW TI THE HUMIDITY AND TEMPERATURE SENSITIVITY OF CLEAR-AIR RADARS IN THE CONVECTIVE BOUNDARY-LAYER SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID INDEX-STRUCTURE PARAMETER; BOTTOM-UP DIFFUSION; REFRACTIVE-INDEX; TOP-DOWN; MODEL; ENTRAINMENT; FLUXES; SCALAR; FLUCTUATIONS; BEHAVIOR AB A top-down/bottom-up diffusion model is used to evaluate the relative contributions of humidity, temperature, and their cross correlation to the radar refractive index structure function paramer C(n)2 in the cloud-free, convective planetary boundary layer (PBL). Profiles of C(n)2 can be measured continuously in the clear air with Doppler radars. Extraction of information about PBL dynamical parameters is more straightforward if C(n)2 is dominated by either moisture (C(q)2) or temperature (C(T)2). In the lower part of the PBL the surface Bowen ratio beta-0 determines this dominance. In the upper part of the PBL the inversion Bowen ratio beta-i is the primary determining factor. The model suggests that humidity accounts for at least 75% of C(n)2 over tropical and midlatitude oceans. Polar oceans, where beta-0 often exceeds 0.5, may not be dominated by either temperature or moisture. Over land beta-0 can easily vary from 0.1 to 10. Geographical regions with beta-0 < 0.3 will be dominated by C(q)2 in the lower PBL; regions with beta-0 > 5 will be dominated by C(T)2. Even for large values of beta-0, the upper part of the PBL will often be dominated by humidity. RP FAIRALL, CW (reprint author), NOAA,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 37 TC 18 Z9 18 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1991 VL 30 IS 8 BP 1064 EP 1074 DI 10.1175/1520-0450(1991)030<1064:THATSO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB987 UT WOS:A1991GB98700002 ER PT J AU DAYAN, U HEFFTER, J MILLER, J GUTMAN, G AF DAYAN, U HEFFTER, J MILLER, J GUTMAN, G TI DUST INTRUSION EVENTS INTO THE MEDITERRANEAN BASIN SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID TRANSPORT; AEROSOLS; ISRAEL AB In this study seven dust intrusion events were identified and analyzed in the central and eastern part of the Mediterranean Sea beginning August 1988 and ending September 1989. In order to locate their sources, characterize their mode, and determine atmospheric transport levels, airflow back trajectories were calculated using the Branching Atmospheric Trajectory (BAT) model for two layers (300-2000 and 1500-3000 m) in conjunction with the synoptic situations prevailing during these dust outbreak events. Aerosol mass loading and horizontal visibility were derived for each of these seven cases from optical thickness values as analyzed by visible and near infrared radiances measured with the NOAA-9 and NOAA-11 satelliteborne radiometers. Optical thickness is displayed in composite weekly charts over the Mediterranean. The analysis has shown that transport of Saharan dust occurring in the central part of the Mediterranean are usually rather intensive in the atmospheric mass-loading capacity and take place in deeper atmospheric layers for a longer duration (approximately 2-4 days) than eastern Mediterranean dust events. The eastern transport usually originates from the Arabian Desert for short periods (approximately 1 day) and is restricted to a rather shallow atmospheric transport layer featured by low optical depth values. C1 NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20230. RP DAYAN, U (reprint author), ISRAEL ATOM ENERGY COMM,SOREQ NUCL RES CTR,IL-70600 YAVNE,ISRAEL. RI Dayan, Uri/D-4855-2014 OI Dayan, Uri/0000-0002-1336-1441 NR 27 TC 87 Z9 87 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1991 VL 30 IS 8 BP 1185 EP 1199 DI 10.1175/1520-0450(1991)030<1185:DIEITM>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB987 UT WOS:A1991GB98700011 ER PT J AU FLEMING, HE CROSBY, DS GOLDBERG, MD AF FLEMING, HE CROSBY, DS GOLDBERG, MD TI EFFICIENCY OF THE SATELLITE RETRIEVAL OF MEAN VIRTUAL TEMPERATURES AS A FUNCTION OF LAYER THICKNESS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Note AB Layer-mean virtual temperatures retrieved from satellite measurements are more accurate than retrievals at specific pressures, not only because an averaging process is involved, but also because of advantages in the retrieval process. In this note, a "retrieval efficiency" is derived to express this advantage over simple averaging as a function of layer thickness. The efficiency is examined for two common cases of retrieval initial guess: a statistical sample mean and a forecast profile obtained from a numerical prediction model. The advantage of the layer-mean retrieval clearly is demonstrated in both cases. C1 ST SYST CORP,LANHAM,MD. AMERICAN UNIV,WASHINGTON,DC 20016. RP FLEMING, HE (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,5200 AUTH RD,WASHINGTON,DC 20233, USA. RI Goldberg, Mitch/F-5589-2010 NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1991 VL 30 IS 8 BP 1237 EP 1242 DI 10.1175/1520-0450(1991)030<1237:EOTSRO>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB987 UT WOS:A1991GB98700016 ER PT J AU NADELLA, RK RAO, MV SIMONS, DS CHI, PH FATEMI, M DIETRICH, HB AF NADELLA, RK RAO, MV SIMONS, DS CHI, PH FATEMI, M DIETRICH, HB TI HIGH-ENERGY SI IMPLANTATION INTO INP-FE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID N-TYPE; INDIUM-PHOSPHIDE; GAAS; PROFILES; DIODES AB High-energy Si implantations were performed into InP:Fe at energies ranging from 0.5 to 10 MeV for a dose of 3 x 10(14) cm-2, and at 3 MeV for the dose ranging from 1 x 10(14) to 2 x 10(15) cm-2. The first four statistical moments of the Si-depth distribution, namely range, longitudinal straggle, skewness, and kurtosis, were calculated from the secondary-ion mass spectrometry (SIMS) data of the as-implanted samples. These values were compared with the corresponding TRIM-89 calculated values. SIMS depth profiles were closely fitted by Pearson IV distributions. Multiple implantations in the energy range from 50 keV to 10 MeV were performed to obtain thick n-type layers. Variable temperature/time halogen lamp rapid thermal annealing (RTA) cycles and 735-degrees-C/10-min furnance annealing were used to activate the Si implants. No redistribution of Si was observed for the annealing cycles used in this study. Activations close to 100% were obtained for 3 x 10(14)-cm-2 Si implants in the energy range from 2 to 10 MeV for 875-degrees-C/10-s RTA. Transport equation calculations were used to interpret low activation results for high dose Si implants. Polaron electrochemical C-V profiling was used to obtain carrier concentration depth profiles. The lattice quality of the as-implanted and annealed material was evaluated by performing x-ray rocking curve measurements. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. USN,RES LAB,WASHINGTON,DC 20375. RP NADELLA, RK (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 25 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1991 VL 70 IS 3 BP 1750 EP 1757 DI 10.1063/1.349515 PG 8 WC Physics, Applied SC Physics GA GA100 UT WOS:A1991GA10000095 ER PT J AU MATEJKA, T SRIVASTAVA, RC AF MATEJKA, T SRIVASTAVA, RC TI AN IMPROVED VERSION OF THE EXTENDED VELOCITY AZIMUTH DISPLAY ANALYSIS OF SINGLE-DOPPLER RADAR DATA SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Extended velocity-azimuth display (EVAD) analysis is useful for obtaining vertical profiles of horizontal divergence, vertical air velocity, vertical hydrometer velocity, and hydrometeor terminal fall speed in widespread precipitation. The technique uses a volume of velocity data collected with a single Doppler radar. Several improvements to the previously reported EVAD technique are discussed. They include the weighting of Fourier series coefficients to reflect their estimated error, a correction for heteroscedasticity (the systematic variation of residuals) in the regression analysis, and the weighting of data from different elevation angles to compensate for the finite thicknesses of the layers in which each analysis is performed. Vertical air velocity is obtained through a variational procedure. Procedures for dealiasing the velocity data and for rejecting outliers from the dataset are summarized. Recommendations for collecting radar data for use in EVAD analysis are made. RP MATEJKA, T (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,RE NSI,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 53 Z9 57 U1 1 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 AUG PY 1991 VL 8 IS 4 BP 453 EP 466 DI 10.1175/1520-0426(1991)008<0453:AIVOTE>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA GC078 UT WOS:A1991GC07800001 ER PT J AU SCHROEDER, JA WESTWATER, ER MAY, PT MCMILLIN, LM AF SCHROEDER, JA WESTWATER, ER MAY, PT MCMILLIN, LM TI PROSPECTS FOR TEMPERATURE SOUNDING WITH SATELLITE AND GROUND-BASED RASS MEASUREMENTS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Temperature profiles from the TIROS-N Operational Vertical Sounder (TOVS) were combined with low-altitude virtual temperature profiles measured by a ground-based 915-MHz/2-kHz radio acoustic sounding system (RASS) at Denver, Colorado. Low-level temperature inversions of more than 20-degrees-C in 100 m, as measured by radiosonde, were successfully resolved by RASS, providing critical information that TOVS alone could not. Conversely, TOVS augmented the RASS altitude coverage, which was typically limited to the first 1-2 km above ground, due to strong acoustic attenuation at 2 kHz. (A 405-MHz/0.9-kHz RASS measures to significantly higher altitudes.) The complementary nature of TOVS and RASS is demonstrated with examples chosen from extreme cases that illustrate the capabilities and limitations of the separate and combined systems. RP SCHROEDER, JA (reprint author), NOAA,WAVE PROPAGAT LAB,MAIL CODE R-E-WP5,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 12 Z9 12 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 1991 VL 8 IS 4 BP 506 EP 513 DI 10.1175/1520-0426(1991)008<0506:PFTSWS>2.0.CO;2 PG 8 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA GC078 UT WOS:A1991GC07800005 ER PT J AU MORAN, KP WUERTZ, DB STRUACH, RG ABSHIRE, NL LAW, DC AF MORAN, KP WUERTZ, DB STRUACH, RG ABSHIRE, NL LAW, DC TI TEMPERATURE SOUNDING WITH WIND PROFILER RADARS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note AB A network of 31 radar wind profilers is being installed in the central United States by the National Oceanic and Atmospheric Administration (NOAA). The radars are expected to measure the vertical profile of horizontal and vertical wind starting at 500 m above the surface (AGL) and extending to about 16 km AGL. These 404.37-MHz radars can also be adapted to measure virtual temperature profiles in the lower troposphere by the radio acoustic sounding system (RASS) technique. RASS experiments were conducted using the prototype radar of the NOAA network, and results showed that virtual temperature profiles can be measured starting at 500 m AGL (the lowest height observed with this radar) and extending to 3.5-5.2 km AGL. RP MORAN, KP (reprint author), NOAA,WAVE PROPAGAT LAB,MAIL CODE R-E-WP4,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 1991 VL 8 IS 4 BP 606 EP 608 DI 10.1175/1520-0426(1991)008<0606:TSWWPR>2.0.CO;2 PG 3 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA GC078 UT WOS:A1991GC07800014 ER PT J AU MELLOR, GL AF MELLOR, GL TI AN EQUATION OF STATE FOR NUMERICAL-MODELS OF OCEANS AND ESTUARIES SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note RP MELLOR, GL (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,POB CN710,SAYRE HALL,PRINCETON,NJ 08544, USA. NR 0 TC 127 Z9 128 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 1991 VL 8 IS 4 BP 609 EP 611 DI 10.1175/1520-0426(1991)008<0609:AEOSFN>2.0.CO;2 PG 3 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA GC078 UT WOS:A1991GC07800015 ER PT J AU SENEKOWITSCH, J ONEIL, S AF SENEKOWITSCH, J ONEIL, S TI METASTABLE 3-SIGMA-G-GROUND STATE OF F-2(++) AND THE BONDING IN MOLECULAR DICATIONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; MULTIPLY CHARGED CATIONS; THEORETICAL INVESTIGATIONS; ELECTRON; N-2(2+); SPECTROSCOPY; EXPANSIONS; SPECTRUM; NITROGEN; AUGER AB Large multireference configuration interaction (MR-CI) calculations on the F2++ ion predict a 3-SIGMA-g- ground state, metastable with respect to tunneling into the F+ + F+ nuclear continuum. The potential energy curve displays a 0.40 eV barrier at R(b) = 1.607 angstrom, between the local potential minimum (R(e) = 1.289 angstrom) and the 3P(g) (F+) + 3P(g) (F+) asymptote at 7.69 eV lower energy. The potential barrier traps four quasibound vibrational levels, with a tunneling lifetime of 16 ms for upsilon = 0. A Dunham analysis at the well minimum gives omega-e = 919.4 cm-1, omega-(e)x(e) = 16.31 cm-1, B(e) = 1.073 cm-1, and alpha-e = 0.0316 cm-1. In a departure from an earlier viewpoint, the origin of the barrier in this and other dications is interpreted as a sum of the e2/R Coulomb repulsion and the ordinary chemical bonding of the constituent ions. This model also explains the purely repulsive character found for the valence-excited 1-DELTA-g and 1-SIGMA-g+ states. RP SENEKOWITSCH, J (reprint author), UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 48 TC 33 Z9 33 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1991 VL 95 IS 3 BP 1847 EP 1851 DI 10.1063/1.461034 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GA106 UT WOS:A1991GA10600043 ER PT J AU MANABE, S STOUFFER, RJ SPELMAN, MJ BRYAN, K AF MANABE, S STOUFFER, RJ SPELMAN, MJ BRYAN, K TI TRANSIENT RESPONSES OF A COUPLED OCEAN ATMOSPHERE MODEL TO GRADUAL CHANGES OF ATMOSPHERIC CO2 .1. ANNUAL MEAN RESPONSE SO JOURNAL OF CLIMATE LA English DT Article AB This study investigates the response of a climate model to a gradual increase or decrease of atmospheric carbon dioxide. The model is a general circulation model of the coupled atmosphere-ocean-land surface system with global geography and seasonal variation of insolation. To offset the bias of the coupled model toward settling into an unrealistic state, the fluxes of heat and water at the ocean-atmosphere interface are adjusted by amounts that vary with season and geography but do not change from one year to the next. Starting from a quasi-equilibrium climate, three numerical time integrations of the coupled model are performed with gradually increasing, constant, and gradually decreasing concentration of atmospheric carbon dioxide. It is noted that the simulated response of sea surface temperature is very slow over the northern North Atlantic and the Circumpolar Ocean of the Southern Hemisphere where vertical mixing of water penetrates very deeply. However, in most of the Northern Hemisphere and low latitudes of the Southern Hemisphere, the distribution of the change in surface air temperature of the model at the time of doubling (or halving) of atmospheric carbon dioxide resembles the equilibrium response of an atmospheric-mixed layer ocean model to CO2 doubling (or halving). For example, the rise of annual mean surface air temperature in response to the gradual increase of atmospheric carbon dioxide increases with latitudes in the Northern Hemisphere and is larger over continents than oceans. When the time-dependent response of the model oceans to the increase of atmospheric carbon dioxide is compared with the corresponding response to the CO2 reduction at an identical rate, the penetration of the cold anomaly in the latter case is significantly deeper than that of the warm anomaly in the former case. The lack of symmetry in the penetration depth of a thermal anomaly between the two cases is associated with the difference in static stability, which is due mainly to the change in the vertical distribution of salinity in high latitudes and temperature changes in middle and low latitudes. Despite the difference in penetration depth and accordingly, the effective thermal inertia of the oceans between the two experiments, the time-dependent response of the global mean surface air temperature in the CO2 reduction experiment is similar in magnitude to the corresponding response in the CO2 growth experiment. In the former experiment with a colder climate, snow and sea ice with high surface albedo cover a much larger area, thereby enhancing their positive feedback effect upon surface air temperature. On the other hand, surface cooling is reduced due to the larger effective thermal inertia of the oceans. Because of the compensation between these two effects, the magnitude of surface air temperature response turned out to be similar between the two experiments. RP MANABE, S (reprint author), PRINCETON UNIV,GEOPHYS FLUID DYNAM LAB,FORRESTAL CAMPUS,US ROUTE 1,POB 308,PRINCETON,NJ 08542, USA. NR 0 TC 657 Z9 672 U1 6 U2 66 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1991 VL 4 IS 8 BP 785 EP 818 DI 10.1175/1520-0442(1991)004<0785:TROACO>2.0.CO;2 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG462 UT WOS:A1991GG46200003 ER PT J AU DUTTON, EG STONE, RS NELSON, DW MENDONCA, BG AF DUTTON, EG STONE, RS NELSON, DW MENDONCA, BG TI RECENT INTERANNUAL VARIATIONS IN SOLAR-RADIATION, CLOUDINESS, AND SURFACE-TEMPERATURE AT THE SOUTH-POLE SO JOURNAL OF CLIMATE LA English DT Article AB Incoming global solar irradiance measured at the surface at the South Pole unexpectedly decreased steadily by 15% from 1976 through 1987 during the late austral summer season, whereas no trend is apparent for September through December. February's irradiance trend, -1.24% yr-1 on the average, is statistically significant at greater than the 99.9% confidence level. The irradiance observations were made continuously with the same calibrated sensor and are confirmed by a second simultaneous solar irradiance measurement series. Associated changes in seasonal sky cover (clouds) and surface air temperature were also observed. Seasonally increasing cloud cover is directly associated with the decreasing irradiance trends, whereas temperatures show a warming trend significant only in March, followed by a cooling trend significant only in May. Cloudiness and temperature records for 32 years suggest that the observed cloudiness trend began in the late 1970s, while the temperature trends become apparent only in the early 1980s. The observed sensitivity of total global solar irradiance to the change in sky cover is roughly six percent per one-tenth and is shown to vary spectrally. Although the annual averages of solar irradiance at the South Pole display an overall decrease between 1976 and 1989, the most recent years in this period show some recovery from earlier declines. Likewise, the downward trends in January and February irradiance diminished in 1988 and 1989. RP DUTTON, EG (reprint author), NOAA,ENVIRONM RES LABS,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 43 Z9 47 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1991 VL 4 IS 8 BP 848 EP 858 DI 10.1175/1520-0442(1991)004<0848:RIVISR>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG462 UT WOS:A1991GG46200006 ER PT J AU BISHOP, GA WILLIAMS, AB AF BISHOP, GA WILLIAMS, AB TI NECROCARCINUS-OLSONORUM, NEW SPECIES, A CRAB (DECAPODA, CALAPPIDAE) FROM THE CRETACEOUS CARLILE SHALE (TURONIAN), WESTERN INTERIOR UNITED-STATES SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID UNION COUNTY; BLACK HILLS; MISSISSIPPI; CRUSTACEA; DAKOTA AB Necrocarcinus olsonorum, new species, is a minor element in the Linuparus faunal association from the Cretaceous Carlile Shale of Turonian Age around the northern and eastern flanks of the Black Hills Uplift in South Dakota and Wyoming. The species is characterized by a highly arched ovate carapace ornamented with rounded bosslike spines and small granules, and dorsal shield with reflexed and rounded edges. The shape, ornamentation, and stratigraphic position of this crab suggest that it is related closely to the ancestral stock of the calappids (i.e., Calappa). Fourteen specimens known from seven localities are preserved as carapaces unassociated with sterna, abdomens, or appendages, possibly indicating the fragility of the missing exoskeletal elements, and suggesting adaptation to a shallow burrowing mode of life in muddy substrates. One carapace preserved with its sternum and proximal parts of pereiopods 1-3 indicates that pereiopods 4 and 5 were reduced. C1 NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560. RP BISHOP, GA (reprint author), GEORGIA SO UNIV,INST ARTHROPODOL & PARASITOL,DEPT GEOL & GEOG,STATESBORO,GA 30460, USA. NR 26 TC 10 Z9 14 U1 0 U2 0 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD AUG PY 1991 VL 11 IS 3 BP 451 EP 459 DI 10.2307/1548470 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA FZ660 UT WOS:A1991FZ66000010 ER PT J AU LUPER, WD EICHMILLER, FC DOBLECKI, W CAMPBELL, D LI, SH AF LUPER, WD EICHMILLER, FC DOBLECKI, W CAMPBELL, D LI, SH TI EFFECT OF 3 STERILIZATION TECHNIQUES ON FINGER PLUGGERS SO JOURNAL OF ENDODONTICS LA English DT Article ID ENDODONTIC INSTRUMENTS; CUTTING EFFICIENCY; FILES AB The effects of different sterilization methods on the fatigue life of finger pluggers were investigated. Ninety finger pluggers for each of four sizes (A, B, C, and D) were subdivided into subgroups of 10. Each subgroup was subjected to 1, 8, or 15 cycles of steam autoclave, dry heat, or bead sterilization. Ten control pluggers for each size were not sterilized. After sterilization, experimental and control finger pluggers were subjected to cyclic bending until fracture. Only the A finger pluggers autoclaved for eight cycles had a significantly lower number of cycles to failure compared with that of the controls. Nine subgroups had significantly greater number of cycles before failure than did the control. Because all but one sterilized group had fatigue lifetimes statistically equal to or greater than nonsterilized controls, clinicians generally can use any of the three sterilization methods without fear of plugger failure. C1 USN,DEPT ENDODONT,DENT CLIN,BREMERTON,WA. NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD. FMFPAC,1ST DENT BN,EL TORO,CA. USN,SCH DENT,DEPT ENDODONT,BETHESDA,MD 20814. NIDR,BIOMETRY SECT,BETHESDA,MD 20892. FU PHS HHS [M00095-06-3014] NR 11 TC 2 Z9 4 U1 1 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0099-2399 J9 J ENDODONT JI J. Endod. PD AUG PY 1991 VL 17 IS 8 BP 361 EP 364 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA FZ185 UT WOS:A1991FZ18500001 PM 1809797 ER PT J AU COFFEY, HE AF COFFEY, HE TI GEOMAGNETIC AND SOLAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note RP COFFEY, HE (reprint author), NOAA,WORLD DATA CTR A SOLAR TERR PHYS,BOULDER,CO 80302, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1991 VL 96 IS A8 BP 14195 EP 14195 DI 10.1029/91JA01806 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ834 UT WOS:A1991FZ83400042 ER PT J AU TANG, DD ROSE, AH DAY, GW ETZEL, SM AF TANG, DD ROSE, AH DAY, GW ETZEL, SM TI ANNEALING OF LINEAR BIREFRINGENCE IN SINGLE-MODE FIBER COILS - APPLICATION TO OPTICAL FIBER CURRENT SENSORS SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article AB Annealing procedures that greatly reduce linear birefringence in single-mode fiber coils are described in detail. These procedures have been successfully applied to coils ranging from 5 mm to 10 cm in diameter and up to 200 or more turns. They involve temperature cycles that last 3-4 days and reach maximum temperatures of about 850-degrees-C. The residual birefringence and induced loss are minimized by proper selection of fiber. The primary application of these coils is optical fiber current sensors, where they yield small sensors that are more stable than those achieved by other techniques. A current sensor with a temperature stability of +8.4 x 10(-5) /K over the range from -75 to + 145-degrees-C has been demonstrated. This is approximately 20% greater than the temperature dependence of the Verdet constant. Packaging degrades the stability, but a packaged sensor coil with a temperature stability of about +1.6 x 10(-4) /K over the range from -20 to + 120-degrees-C has also been demonstrated. RP TANG, DD (reprint author), NIST,BOULDER,CO 80303, USA. NR 18 TC 82 Z9 86 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD AUG PY 1991 VL 9 IS 8 BP 1031 EP 1037 DI 10.1109/50.84170 PG 7 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA FY177 UT WOS:A1991FY17700014 ER PT J AU HUBER, HR ROVETTA, AC FRY, LA JOHNSTON, S AF HUBER, HR ROVETTA, AC FRY, LA JOHNSTON, S TI AGE-SPECIFIC NATALITY OF NORTHERN ELEPHANT SEALS AT THE SOUTH FARALLON ISLANDS, CALIFORNIA SO JOURNAL OF MAMMALOGY LA English DT Article ID LEPTONYCHOTES-WEDDELLI; 1ST REPRODUCTION; POPULATION; DYNAMICS; SUCCESS AB We monitored 233 tagged, known-age female northern elephant seals (Mirounga angustirostris), age 3-16 years, that gave birth on the South Farallon Islands, 1975-1986. Females were from the 1970-1982 cohorts born on South Farallon, Ano Nuevo, San Nicolas, and San Miguel islands, California. Age-specific natality was significantly lower for 3- and 4-year olds (0.13 and 0.75, respectively), then stabilized at about 0.80 for females age 5-10 years. Natality was significantly lower in 1984 and 1985 than in other years. For the 1971-1980 cohorts, mean age at first reproduction ranged from 3.9 to 4.6 years. During this study, the age structure of females giving birth on the South Farallon Islands changed; mean age rose from 4 years in 1975 to 7 years in 1986. At least 20% of Farallon-born females survived to reproduce, greater-than-or-equal-to 17% returned to the South Farallon Islands, and greater-than-or-equal-to 3% emigrated to other rookeries. Females born at Ano Nuevo, San Miguel, and San Nicolas islands immigrated to the South Farallon Islands to give birth (greater-than-or-equal-to 3, greater-than-or-equal-to 2, and greater-than-or-equal-to 1% respectively). Mature, nonpregnant females were seen during the breeding season (6%), during the autumn haul out (15%), and during spring molt or a later breeding season (79%). C1 POINT REYES BIRD OBSERVAT,4990 SHORELINE HIGHWAY,STINSON BEACH,CA 94970. RP HUBER, HR (reprint author), ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Logger, Satellite/C-1379-2010 NR 31 TC 16 Z9 16 U1 1 U2 4 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 1991 VL 72 IS 3 BP 525 EP 534 DI 10.2307/1382136 PG 10 WC Zoology SC Zoology GA GB706 UT WOS:A1991GB70600011 ER PT J AU ZHOU, SJ THOMSON, R AF ZHOU, SJ THOMSON, R TI SHIELDING OF CRACKS IN A PLASTICALLY POLARIZABLE MATERIAL SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TIP; DUCTILE; DISLOCATIONS AB In this paper, we address some fundamental questions regarding the response of a crack to externally generated dislocations. We note that since dislocations that formed at external sources in the material must be in the form of loops or dipoles, the theory must be couched in terms of crack shielding in a plastically polarizable medium. There are strong analogies to dielectric theory. We prove two general theorems: (1) Dipoles formed in the emission geometry relative to a crack tip always antishield the crack and (2) when dipoles are induced during uniform motion of a crack through a uniformly plastically polarizable material, then the net shielding is always positive. We illustrate these general theorems with a number of special cases for fixed and polarizable sources. Finally, we simulate the self consistent time dependent response of a crack to a polarizable source as the crack moves past it. The results show that the crack is initially antishielded, but that positive shielding always dominates during later stages of configuration evolution. The crack may be arrested by the source, or it may break away from it, depending upon the various parameters (source strength and geometry, dislocation mobility, Griffith condition for the crack, etc.). The results indicate that the time dependence of crack shielding in the presence of a nonuniform density of sources will be very important in practical cases of brittle transitions in materials. RP ZHOU, SJ (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 16 TC 7 Z9 7 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1991 VL 6 IS 8 BP 1763 EP 1772 DI 10.1557/JMR.1991.1763 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA GA521 UT WOS:A1991GA52100023 ER PT J AU ORTIGOSO, J ESCRIBANO, R BURKHOLDER, JB HOWARD, CJ LAFFERTY, WJ AF ORTIGOSO, J ESCRIBANO, R BURKHOLDER, JB HOWARD, CJ LAFFERTY, WJ TI HIGH-RESOLUTION INFRARED-SPECTRUM OF THE NU-1 BAND OF OCLO SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID CHLORINE DIOXIDE; MICROWAVE SPECTROSCOPY; MOLECULES; LEVEL; STATE C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80303. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP ORTIGOSO, J (reprint author), CSIC,INST ESTRUCT MAT,SERRANO 119,E-28006 MADRID,SPAIN. RI Burkholder, James/H-4914-2013; Escribano, Rafael/I-4599-2015; Ortigoso, Juan/F-1234-2016 OI Escribano, Rafael/0000-0002-3048-9420; NR 30 TC 22 Z9 22 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD AUG PY 1991 VL 148 IS 2 BP 346 EP 370 DI 10.1016/0022-2852(91)90392-N PG 25 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FX630 UT WOS:A1991FX63000007 ER PT J AU NELIS, T BEATON, SP EVENSON, KM BROWN, JM AF NELIS, T BEATON, SP EVENSON, KM BROWN, JM TI A DETERMINATION OF THE MOLECULAR-PARAMETERS FOR NIH IN ITS 2-DELTA GROUND-STATE BY LASER MAGNETIC-RESONANCE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID OPTICAL DOUBLE-RESONANCE; ELECTRIC-DIPOLE MOMENT; ROTATIONAL ANALYSIS; DIATOMIC-MOLECULES; SPECTROSCOPY; SPECTRUM; TRANSITIONS; ASSIGNMENT; CRH; FEH C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. PHYS CHEM LAB,OXFORD OX1 3QZ,ENGLAND. RP NELIS, T (reprint author), UNIV BONN,INST ANGEW PHYS,WEGELERSTR 8,W-5300 BONN 1,GERMANY. RI Nelis, Thomas/D-9581-2015 OI Nelis, Thomas/0000-0002-0061-8850 NR 40 TC 22 Z9 22 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD AUG PY 1991 VL 148 IS 2 BP 462 EP 478 DI 10.1016/0022-2852(91)90402-V PG 17 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FX630 UT WOS:A1991FX63000017 ER PT J AU LIU, SW DATTA, SK KHAIR, KR SHAH, AH AF LIU, SW DATTA, SK KHAIR, KR SHAH, AH TI DYNAMIC-RESPONSE OF PIPELINES BURIED IN BACK-FILLED TRENCHES SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Dynamic response of pipelines buried in a back-filled rectangular trench in a semi-infinite medium has been investigated. The pipelines are modeled as long cylindrical shells of small thickness. By using the boundary integral representation and finite element method, we have studied the three-dimensional response to account for either plane P or SV wave incident at an arbitrary angle to the pipe-axis. Numerical results are presented for the normal displacements, displacements along pipe-axis, and the hoop stresses in the pipe wall. It is shown that the response depends critically on the back-filled material as well as on the directions of propagation of the incident waves. C1 UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV MANITOBA,DEPT CIVIL ENGN,WINNIPEG R3T 2N2,MANITOBA,CANADA. NR 7 TC 2 Z9 2 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 1991 VL 113 IS 3 BP 429 EP 436 DI 10.1115/1.2928778 PG 8 WC Engineering, Mechanical SC Engineering GA HP755 UT WOS:A1991HP75500013 ER PT J AU FAIRALL, CW WHITE, AB THOMSON, DW AF FAIRALL, CW WHITE, AB THOMSON, DW TI A STOCHASTIC-MODEL OF GRAVITY-WAVE INDUCED CLEAR-AIR TURBULENCE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ATMOSPHERIC WAVENUMBER SPECTRA; COMMERCIAL AIRCRAFT; RICHARDSON-NUMBER; TEMPERATURE; LAYERS; WIND; STRATOSPHERE; FLUCTUATIONS; STATISTICS; RADAR AB We examine the consequences of using a vertical wavenumber spectral model to describe variations of vertical profiles of atmospheric variables (horizontal and vertical wind, temperature, and other scalars) about a mean profile. At high wavenumbers the model exhibits a wavenumber to the -3 dependence, which is characteristic of a continuum of internal gravity waves whose amplitudes are controlled by a breaking process. By employing a random phase between wavenumber amplitude components, a reverse fourier transform of the spectrum yields simulated profiles of velocity and thermal variability as well as shear and Brunt-Vaisala frequency variability. Individual components of the vertical shear of the horizontal wind and the Brunt-Vaisala frequency exhibit Gaussian distributions; the square of the magnitude of the shear exhibits a Rice-Nakagami distribution. Assuming regions with Ri < 0.25 are turbulent, we can examine a number of aspects of the occurrence of clear-air turbulent breakdown in the stratified free atmosphere. For a typical tropospheric condition, the average turbulent layer thickness turns out to be about 35 m and about 20% of the troposphere appears to be actively turbulent. The majority of the turbulent layers appear to be due to autoconvective overturning instead of Kelvin-Helmholtz dynamic instability. Computations of profiles of the refractive index structure function parameter, C(n)2, and the rate of dissipation of turbulent kinetic energy, epsilon, are found to be quite sensitive to the assumptions of the relationship of turbulent length scale to layer thickness, the growth of turbulent layers after breakdown, and the threshold sensitivity and sampling strategy of measurement systems (e.g., clear-air radar). C1 PENN STATE UNIV,DEPT METEOROL,UNIVERSITY PK,PA 16802. RP FAIRALL, CW (reprint author), NOAA,ERL,ATMOSPHER STUDIES PROGRAM AREA,325 BROADWAY,BOULDER,CO 80303, USA. RI White, Allen/A-7946-2009 NR 40 TC 25 Z9 26 U1 2 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 1 PY 1991 VL 48 IS 15 BP 1771 EP 1790 DI 10.1175/1520-0469(1991)048<1771:ASMOGW>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GG358 UT WOS:A1991GG35800006 ER PT J AU GLADU, PK PATTERSON, GW WIKFORS, GH LUSBY, WR AF GLADU, PK PATTERSON, GW WIKFORS, GH LUSBY, WR TI FREE AND COMBINED STEROLS OF PAVLOVA-GYRANS SO LIPIDS LA English DT Article; Proceedings Paper CT SYMP AT THE 1990 ANNUAL MEETING OF THE AMERICAN OIL CHEMISTS SOC : PLANT AND FUNGAL STEROLS : BIOSYNTHESIS, METABOLISM AND FUNCTION CY APR, 1990 CL BALTIMORE, MD SP AMER OIL CHEMISTS SOC ID NMR-SPECTRA; ALGAE; PRYMNESIOPHYCEAE; IDENTIFICATION; PHYTOPLANKTON; PHYTOSTEROLS; FAMILIES; LIPIDS; WATER; C-24 AB Pavlova gyrans, a unicellular alga of interest as food for oysters, was cultured axenically and examined for sterol composition. Desmethyl monohydroxy sterols, which are frequently seen in algae, made up 40% of the total sterols and were observed primarily in the free sterol fraction. The principal sterols of this group were 5-ergostenol, poriferasterol, and clionasterol, as well as some poriferast-22-enol and poriferastanol. Several "methyl" sterols with unusual structures made up 27% of the total sterols. The principal "methyl sterols" were 4-alpha-methyl ergostanol, 4-alpha-methyl poriferastanol, and 4-alpha-methyl poriferast-22-enol. Methyl sterols were found primarily in the ester fraction. Also observed was a new class of dihydroxysterols composing 33% of the total sterols. These sterols are structurally related to the methyl and desmethyl sterols of Pavlova but contain an extra nuclear hydroxyl which can be acetylated when present on a desmethyl sterol, but which is nonreactive with acetic anhydride in 4-alpha-methyl sterols. None of these sterols were observed in ester form but are concentrated in the acid-hydrolyzable, bound fraction. The unique nature of these sterols suggests potential taxonomic utility. C1 UNIV MARYLAND,DEPT BOT,COLLEGE PK,MD 20742. NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,MILFORD LAB,MILFORD,CT 06460. USDA ARS,BELTSVILLE AGR RES CTR,INSECT PHYSIOL LAB,BELTSVILLE,MD 20705. NR 31 TC 17 Z9 18 U1 0 U2 1 PU AMER OIL CHEMISTS SOC PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 SN 0024-4201 J9 LIPIDS JI Lipids PD AUG PY 1991 VL 26 IS 8 BP 656 EP 659 DI 10.1007/BF02536431 PG 4 WC Biochemistry & Molecular Biology; Nutrition & Dietetics SC Biochemistry & Molecular Biology; Nutrition & Dietetics GA GB766 UT WOS:A1991GB76600013 ER PT J AU DOMICH, PD HOFFMAN, KL JACKSON, RHF MCCLAIN, MA AF DOMICH, PD HOFFMAN, KL JACKSON, RHF MCCLAIN, MA TI LOCATING TAX FACILITIES - A GRAPHICS-BASED MICROCOMPUTER OPTIMIZATION MODEL SO MANAGEMENT SCIENCE LA English DT Article DE INCAPACITATED FACILITY LOCATION; PLANT LOCATION; APPLICATION TO TAX SERVICE; LAGRANGIAN APPROACH; HEURISTIC ALGORITHM; MICROCOMPUTER; INTERACTIVE GRAPHICS AB This paper presents a mathematical model that selects locations for Internal Revenue Service Posts-of-Duty. The system is microcomputer-based and uses menus and graphically displayed zip code maps of IRS districts for interactive inputs and solution outputs. The mathematical model used for this problem is the uncapacitated, fixed charge, location-allocation model which minimizes travel and facility costs, given a specified level of activity. A greedy-interchange heuristic is used to obtain "good" solutions to the problem and is coupled with a lagrangian-relaxation technique providing a measure of how far from optimality the current solution can be. An example with Florida data illustrates the use of the model. C1 GEORGE MASON UNIV,DEPT OPERAT RES & APPL STAT,FAIRFAX,VA 22030. NATL INST STAND & TECHNOL,MFG ENGN LAB,GAITHERSBURG,MD 20899. RP DOMICH, PD (reprint author), NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,BOULDER,CO 80303, USA. NR 26 TC 12 Z9 12 U1 0 U2 2 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0025-1909 J9 MANAGE SCI JI Manage. Sci. PD AUG PY 1991 VL 37 IS 8 BP 960 EP 979 DI 10.1287/mnsc.37.8.960 PG 20 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA GE857 UT WOS:A1991GE85700004 ER PT J AU BUCKLEY, LJ SMIGIELSKI, AS HALAVIK, TA CALDARONE, EM BURNS, BR LAURENCE, GC AF BUCKLEY, LJ SMIGIELSKI, AS HALAVIK, TA CALDARONE, EM BURNS, BR LAURENCE, GC TI WINTER FLOUNDER PSEUDOPLEURONECTES-AMERICANUS REPRODUCTIVE SUCCESS .1. AMONG-LOCATION VARIABILITY IN SIZE AND SURVIVAL OF LARVAE REARED IN THE LABORATORY SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article ID RNA-DNA RATIO; EGG SIZE; BIOCHEMICAL-COMPOSITION; FISH EGGS; GROWTH; TEMPERATURE; MORTALITY; SEA AB Winter flounder Pseudopleuronectes americanus collected at selected locations in Long Island Sound (LIS), New York, and Narragansett Bay (NB), Rhode Island, USA, were spawned in the laboratory and the larvae reared for a month after hatching. In 1987 the average size of yolk-sac larvae varied widely among locations. Moreover, a direct correlation was observed between size of yolk-sac larvae and survival for the first month of life. Fish from NB produced the smallest larvae with the lowest survival rate. The Madison site in LIS produced the largest yolk-sac larvae with the highest survival rate. Size and biochemical composition (mu-g larva-1) of yolk-sac larvae were correlated. Dry weight and RNA content were the best predictors of survival potential among the variables considered (protein, DNA, lipid content, and RNA/DNA ratio). In 1988 little difference was observed in viable hatch or weight of yolk-sac larvae among locations. While no significant difference in larval survival was observed between NB and LIS fish, survival was higher in the Madison group than the Morris Cove group from LIS. These data suggest that when differences in size among newly hatched larvae are sufficiently large, survival potential can be affected. RP BUCKLEY, LJ (reprint author), NATL MARINE FISHERIES SERV, NE FISHERIES CTR, NARRAGANSETT LAB, NARRAGANSETT, RI 02882 USA. NR 40 TC 27 Z9 27 U1 0 U2 11 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD AUG PY 1991 VL 74 IS 2-3 BP 117 EP 124 DI 10.3354/meps074117 PG 8 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA GC139 UT WOS:A1991GC13900002 ER PT J AU BUCKLEY, LJ SMIGIELSKI, AS HALAVIK, TA CALDARONE, EM BURNS, BR LAURENCE, GC AF BUCKLEY, LJ SMIGIELSKI, AS HALAVIK, TA CALDARONE, EM BURNS, BR LAURENCE, GC TI WINTER FLOUNDER PSEUDOPLEURONECTES-AMERICANUS REPRODUCTIVE SUCCESS .2. EFFECTS OF SPAWNING TIME AND FEMALE SIZE ON SIZE, COMPOSITION AND VIABILITY OF EGGS AND LARVAE SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article ID CLUPEA-HARENGUS-PALLASI; TEMPERATURE; GROWTH; MECHANISMS; SURVIVAL; CYCLE; AGE AB Vital statistics and embryo and larval viability were determined for winter flounder Pseudopleuronectes americanus spawning in Narragansett Bay, Rhode Island, USA, over the course of the spawning season. Fish approaching spawning condition were collected throughout the spawning season and hand-stripped in the laboratory. Larvae were reared through the first month of life. Female size affected most of the reproductive parameters examined, including both absolute and relative measures of total reproductive output (reproductive rate and gonadosomatic index), egg size, fecundity, and viability. Spawning time was found to affect egg size, fecundity, and viability, but not reproductive rate or gonadosomatic index. Egg size increased with increasing female size and decreased as the spawning season progressed. Spawning time and female size explained 61% of the observed variability in egg size among females. Female size explained 95% of the variability in reproductive rate and 90% of the variability in fecundity. Female size and spawning time combined explained 94% of the variability in fecundity. The effects of female size and spawning time on both fertility and hatch rate were non-additive. Embryos produced earlier in the spawning season appeared to have a survival advantage over those produced later in the spawning season. Embryos produced by small, late-spawning fish appeared to be at a pronounced disadvantage. RP BUCKLEY, LJ (reprint author), NATL MARINE FISHERIES SERV, NE FISHERIES CTR, NARRAGANSETT LAB, NARRAGANSETT, RI 02882 USA. NR 30 TC 79 Z9 81 U1 4 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD AUG PY 1991 VL 74 IS 2-3 BP 125 EP 135 DI 10.3354/meps074125 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA GC139 UT WOS:A1991GC13900003 ER PT J AU DZIAK, RP FOX, CG EMBLEY, RW AF DZIAK, RP FOX, CG EMBLEY, RW TI RELATIONSHIP BETWEEN THE SEISMICITY AND GEOLOGIC STRUCTURE OF THE BLANCO TRANSFORM-FAULT ZONE SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article DE BLANCO TRANSFORM; DIVERGENT WRENCH-FAULT; EARTHQUAKE; B-VALUE; SEISMIC MOMENT; FAULT LENGTH ID PULL-APART BASINS; EARTHQUAKES; RIDGE AB Morphologic studies of an oceanic transform, the Blanco Transform Fault Zone (BTFZ), have shown it to consist of a series of extensional basins that offset the major strike-slip faults. The largest of the extensional basins, the Cascadia Depression, effectively divides the transform into a northwest segment, composed of several relatively short strike-slip faults, and a southeast segment dominated by fewer, longer faults. The regional seismicity distribution (m(b) greater-than-or-equal-to 4.0) and frequency-magnitude relationships (b-values) of the BTFZ show that the largest magnitude events are located on the southeast segment. Furthermore, estimates of the cumulative seismic moment release and seismic moment release rate along the southeast segment are significantly greater than that of the northwest segment. These observations suggest that slip along the southeast segment is accommodated by a greater number of large magnitude earthquakes. Comparison of the seismic moment rate, derived from empirical estimates, with the seismic moment rate determined from plate motion constraints suggests a difference in the seismic coupling strength between the segments. This difference in coupling may partially explain the disparity in earthquake size distribution. However, the results appear to confirm the relation between earthquake size and fault length, observed along continental strike-slip faults, for this oceanic transform. RP DZIAK, RP (reprint author), OREGON STATE UNIV,CHEM & APPL CHEM,PACIFIC MARINE ENVIRONM LAB,NEWPORT,OR 97365, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 23 TC 18 Z9 19 U1 0 U2 1 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 AUG PY 1991 VL 13 IS 3 BP 203 EP 208 DI 10.1007/BF00369149 PG 6 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA GN631 UT WOS:A1991GN63100002 ER PT J AU BLESSING, GV EITZEN, DG HENNING, JF KODAMA, RH CLARK, AV SCHRAMM, RE AF BLESSING, GV EITZEN, DG HENNING, JF KODAMA, RH CLARK, AV SCHRAMM, RE TI PRECISION ULTRASONIC THICKNESS MEASUREMENTS ON THIN STEEL PARTS SO MATERIALS EVALUATION LA English DT Article DE ACOUSTICS; FERROUS MATERIAL; HOLOGRAPHY; INTERFEROMETRY; LASER; NONDESTRUCTIVE EVALUATION; PROCESS CONTROL; QUALITY CONTROL; SIGNAL PROCESSING; STEEL PLATE; ULTRASONIC TESTING AB Precise elastic-wave transmit-time measurements have been made on thin (1-2 mm) stainless steel samples to assess the accuracy of the ultrasonic technique for providing dimensional information. With an accuracy goal approaching a micrometer, transmit-time measurements were made to a fraction of a nanosecond. Pulse-echo longitudinal-wave measurements by sample immersion, and resonant non-contact shear-wave measurements, are compared with accurate laser interferometer measurements on a set of flat disks. The effects of variable material conditions and properties on wave propagation are evaluated, including the material texture and grain size, sample parallelism, surface roughness, and temperature. In particular, the limitation on dimensional precision for thin parts with a finite grain-size structure is demonstrated and understood with the help of a theoretical model. Finally, the application of the ultrasonic technique to curved geometries in an on-line environment is described, with initial results on hemispherical shells presented. RP BLESSING, GV (reprint author), NATL INST STAND & TECHNOL,ULTRASON STAND GRP,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD AUG PY 1991 VL 49 IS 8 BP 982 EP 986 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA GA561 UT WOS:A1991GA56100004 ER PT J AU SANDLIN, AC SCHAEFER, RJ AF SANDLIN, AC SCHAEFER, RJ TI SURFACE-ENERGY REDUCTION IN FIBROUS MONOTECTIC STRUCTURES SO METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID SOLIDIFICATION; ALLOYS AB A study has been made of the morphology of directionally solidified CuAl-Pb monotectic alloys. The structure consisted of a hexagonal array of Pb rods in a Cu-based matrix. In addition, highly curved grain boundaries in the Cu-based matrix with lens-shaped Pb fibers on the boundary and a "denuded zone" depleted of Pb rods were observed. Existence of these boundaries is shown to reduce the overall surface energy of the system leading to the formation of the highly curved grain boundaries. RP SANDLIN, AC (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0360-2133 J9 METALL TRANS A PD AUG PY 1991 VL 22 IS 8 BP 1881 EP 1886 DI 10.1007/BF02646513 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA GA563 UT WOS:A1991GA56300021 ER PT J AU MAUER, FA NORTON, SJ GRINBERG, Y PITCHURE, D WADLEY, HNG AF MAUER, FA NORTON, SJ GRINBERG, Y PITCHURE, D WADLEY, HNG TI AN ULTRASONIC METHOD FOR RECONSTRUCTING THE 2-DIMENSIONAL LIQUID-SOLID INTERFACE IN SOLIDIFYING BODIES SO METALLURGICAL TRANSACTIONS B-PROCESS METALLURGY LA English DT Article ID EMAT DESIGNS AB A method is demonstrated for reconstructing the two-dimensional boundary of the liquid core in a solidifying strand of aluminum using ultrasonic time-of-flight data. Approximating the boundary by an ellipse leads to a model that can be used to calculate the time of flight along any path in the plane of the ellipse. The shape and location of the ellipse is specified by four free parameters. A least-squares algorithm is then used to find the set of four parameters that provides the best fit to the measured time-of-flight data on ten intersecting paths through the strand. For a strand with a 6-in. square cross section, the agreement between the actual interface and the computed interface was within about +/- 2 pct. Reference data for the temperature dependence of the longitudinal velocity for solid 1100 aluminum are included. C1 UNIV VIRGINIA,DEPT MAT SCI,CHARLOTTESVILLE,VA 22903. RP MAUER, FA (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 14 TC 13 Z9 21 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0360-2141 J9 METALL TRANS B PD AUG PY 1991 VL 22 IS 4 BP 467 EP 473 DI 10.1007/BF02654284 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA GA233 UT WOS:A1991GA23300007 ER PT J AU COHN, SE PARRISH, DF AF COHN, SE PARRISH, DF TI THE BEHAVIOR OF FORECAST ERROR COVARIANCES FOR A KALMAN FILTER IN 2 DIMENSIONS SO MONTHLY WEATHER REVIEW LA English DT Article ID ADJOINT VORTICITY EQUATION; METEOROLOGICAL OBSERVATIONS; VARIATIONAL ASSIMILATION; STATISTICAL STRUCTURE; OBJECTIVE ANALYSIS; RADIOSONDE DATA; SCHEME; SYSTEM AB A Kalman filter algorithm is implemented for a linearized shallow-water model over the continental United States. It is used to assimilate simulated data from the existing radiosonde network, from the demonstration network of 31 Doppler wind profilers in the central United States, and from hypothetical radiometers located at five of the profiler sites. We provide some theoretical justification of Phillips' hypothesis, and we use the hypothesis, with some modification, to formulate the model error covariance matrix required by the Kalman filter. Our results show that assimilating the profiler wind data leads to a large reduction of forecast/analysis error in heights as well as in winds, over the profiler region and also downstream, when compared with the results of assimilating the radiosonde data alone. The forecast error covariance matrices that the Kalman filter calculates to obtain this error reduction, however, differ considerably from those prescribed by the optimal interpolation schemes that are employed for data assimilation at operational centers. Height-height forecast error correlation functions spread out broadly over the profiler region. Height-wind correlation functions for a base point near the boundary of the profiler region are not antisymmetric with respect to the line of zero correlation, nor does the zero-line pass through the base point. We explain why these effects on forecast error correlations are to be expected for wind profilers, which provide abundant wind information but no height information. Our explanation is supported by further experiments in which height observations assimilated from radiometers at just a few profiler sites reduce these effects. C1 NYU,COURANT INST MATH SCI,NEW YORK,NY 10012. RP COHN, SE (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,NATL WEATHER SERV,DIV DEV,WASHINGTON,DC 20233, USA. RI Cohn, Stephen/K-1954-2012 OI Cohn, Stephen/0000-0001-8506-9354 NR 47 TC 86 Z9 93 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1991 VL 119 IS 8 BP 1757 EP 1785 DI 10.1175/1520-0493(1991)119<1757:TBOFEC>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB419 UT WOS:A1991GB41900001 ER PT J AU MAYFIELD, M LAWRENCE, MB AF MAYFIELD, M LAWRENCE, MB TI ATLANTIC HURRICANE SEASON OF 1990 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1990 hurricane season is summarized, including accounts of individual storms. Fourteen tropical storms were tracked of which eight became hurricanes. Only one storm, Marco, hit the United States. RP MAYFIELD, M (reprint author), NOAA,NATL WEATHER SERV,NATL HURRICANE CTR,1320 S DIXIE HIGHWAY,ROOM 631,CORAL GABLES,FL 33146, USA. NR 8 TC 8 Z9 8 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1991 VL 119 IS 8 BP 2014 EP 2026 DI 10.1175/1520-0493(1991)119<2014:AHSO>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB419 UT WOS:A1991GB41900012 ER PT J AU AVILA, LA AF AVILA, LA TI ATLANTIC TROPICAL SYSTEMS OF 1990 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1991 hurricane season produced 76 tropical waves of which 12 became tropical depressions. African seedlings initiated 10 of the 14 named Atlantic storms and all of the eastern Pacific tropical cyclones. A comparison with previous years is presented. RP AVILA, LA (reprint author), NOAA,NATL WEATHER SERV,NATL HURRICANE CTR,1320 S DIXIE HIGHWAY,ROOM 631,CORAL GABLES,FL 33146, USA. NR 7 TC 12 Z9 13 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1991 VL 119 IS 8 BP 2027 EP 2033 DI 10.1175/1520-0493(1991)119<2027:ATSO>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB419 UT WOS:A1991GB41900013 ER PT J AU AVILA, LA AF AVILA, LA TI EASTERN NORTH PACIFIC HURRICANE SEASON OF 1990 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1990 eastern Pacific hurricane season is summarized. Twenty tropical storms were tracked of which 16 became hurricanes. Hurricanes Hernan and Trudy were among the strongest ever observed in this area. Rachel was the only system to make landfall. RP AVILA, LA (reprint author), NOAA,NATL WEATHER SERV,NATL HURRICANE CTR,1320 S DIXIE HIGHWAY,ROOM 631,CORAL GABLES,FL 33146, USA. NR 1 TC 13 Z9 13 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1991 VL 119 IS 8 BP 2034 EP 2046 DI 10.1175/1520-0493(1991)119<2034:ENPHSO>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA GB419 UT WOS:A1991GB41900014 ER PT J AU TESHIMA, K HONKALEHTO, T YOSHIMURA, T AF TESHIMA, K HONKALEHTO, T YOSHIMURA, T TI MATURITY CONDITION OF PELAGIC WALLEYE POLLOCK FROM THE ALEUTIAN BASIN OF THE BERING SEA SO NIPPON SUISAN GAKKAISHI LA English DT Article AB Maturity condition of pelagic walleye pollock Theragra chalcogramma in the winter Aleutian Basin was examined from GSI (gonadosomatic index) changing trend and observations of gonads collected through midwater trawl samplings conducted during December, 1988 to February, 1989. Throughout the whole survey period female GSI values increased gradually and rapidly reached the highest level around late February while those of males remained unchanged. Spawning female and spermatozoa-releasing male pollock occurred during late February in the southeastern waters of the Aleutian Basin. Assuming that pollock migrate eastward in the Aleutian Basin during winter and spawn in the southeastern Aleutian Basin, spawning was suggested to begin late in February in 1989. C1 NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA. FISHERIES AGCY JAPAN,NATL RES INST FAR SEAS FISHERIES,SHIMIZU 424,JAPAN. RP TESHIMA, K (reprint author), FISHERIES AGCY JAPAN,SEIKAI NATL FISHERIES RES INST,SHIMONOSEKI BRANCH,SHIMONOSEKI 750,JAPAN. NR 3 TC 1 Z9 1 U1 0 U2 0 PU JAPAN SOC SCI FISHERIES TOKYO UNIV FISHERIES PI TOKYO PA 5-7 KONAN-4 MINATO-KU, TOKYO 108, JAPAN SN 0021-5392 J9 NIPPON SUISAN GAKK JI Nippon Suisan Gakkaishi PD AUG PY 1991 VL 57 IS 8 BP 1495 EP 1499 PG 5 WC Fisheries SC Fisheries GA GP409 UT WOS:A1991GP40900011 ER PT J AU SANFORD, NA MALONE, KJ LARSON, DR HICKERNELL, RK AF SANFORD, NA MALONE, KJ LARSON, DR HICKERNELL, RK TI Y-BRANCH WAVE-GUIDE GLASS-LASER AND AMPLIFIER SO OPTICS LETTERS LA English DT Article ID WAVE-GUIDE LASER AB A Y-branch channel waveguide laser operating near 1057 nm was fabricated by electric-field-assisted ion exchange in Nd-doped silicate glass. The overall length was 24 mm. Optical pumping was performed with a cw Ti:sapphire laser. Mirrors were bonded to the polished waveguide facets. The slope efficiency was 5.1% when a 4%-transmitting output coupler was used. Threshold was reached at 26-mW absorbed pump power. The device exhibited a single-pass small-signal gain of 0.034 dB/mW when operated as an amplifier. The 3-dB splitting loss of the Y-branch structure was overcome when the absorbed pump power was approximately 85 mW. RP SANFORD, NA (reprint author), NATL INST STANDARDS & TECHNOL,OPT ELECTR METROL GRP 81402,325 BROADWAY,BOULDER,CO 80303, USA. NR 7 TC 26 Z9 28 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 1 PY 1991 VL 16 IS 15 BP 1168 EP 1170 DI 10.1364/OL.16.001168 PG 3 WC Optics SC Optics GA GA143 UT WOS:A1991GA14300014 PM 19776909 ER PT J AU MAJKRZAK, CF AF MAJKRZAK, CF TI POLARIZED NEUTRON REFLECTOMETRY SO PHYSICA B-CONDENSED MATTER LA English DT Article ID MAGNETIC DEPTH PROFILES; LARMOR PRECESSION; THIN-FILMS; SCATTERING; REFLECTION; SUPERLATTICES; DIFFRACTION; TIME AB Polarized neutron reflectometry is a powerful technique for studying the microscopic magnetic structures in thin films and multilayers. The corresponding analysis of spin-dependent reflectivity data is discussed and illustrated with a number of specific examples. The measurement of the precession of the neutron moment within a nonmagnetic medium, but in the presence of an applied field, as a means of determining the nuclear density profile is also considered. RP MAJKRZAK, CF (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 46 TC 85 Z9 85 U1 1 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD AUG PY 1991 VL 173 IS 1-2 BP 75 EP 88 DI 10.1016/0921-4526(91)90037-F PG 14 WC Physics, Condensed Matter SC Physics GA GD895 UT WOS:A1991GD89500011 ER PT J AU ANKNER, JF MAJKRZAK, CF NEUMANN, DA MATHENY, A FLYNN, CP AF ANKNER, JF MAJKRZAK, CF NEUMANN, DA MATHENY, A FLYNN, CP TI POLARIZED NEUTRON GRAZING ANGLE DIFFRACTION SO PHYSICA B-CONDENSED MATTER LA English DT Article ID GD-Y SUPERLATTICE; BRAGG-DIFFRACTION; X-RAY; REFLECTION; SCATTERING; MAGNETISM; ORDER AB The principles underlying grazing angle X-ray diffraction can be applied to neutrons. We derive a formalism for the treatment of grazing angle diffraction using polarized neutrons and present measurements employing this geometry to observe the magnetization of an Y/Gd film. C1 UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. UNIV ILLINOIS, MAT RES LAB, URBANA, IL 61801 USA. RP ANKNER, JF (reprint author), NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. OI Ankner, John/0000-0002-6737-5718 NR 18 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 1991 VL 173 IS 1-2 BP 89 EP 95 DI 10.1016/0921-4526(91)90038-G PG 7 WC Physics, Condensed Matter SC Physics GA GD895 UT WOS:A1991GD89500012 ER PT J AU HECKMANN, PH MOLLER, G TRABERT, E WAGNER, C MARTINSON, I BLANKE, JH SUGAR, J AF HECKMANN, PH MOLLER, G TRABERT, E WAGNER, C MARTINSON, I BLANKE, JH SUGAR, J TI INTERCOMBINATION LINES IN ZN-LIKE, GA-LIKE AND GE-LIKE NB SO PHYSICA SCRIPTA LA English DT Article ID ZINC ISOELECTRONIC SEQUENCE; ENERGY-LEVELS; TRANSITION-PROBABILITIES; OSCILLATOR-STRENGTHS; 2-ELECTRON SPECTRA; 4S-4P TRANSITIONS; NICKEL-LIKE; MO-XIII; IONS; WAVELENGTHS AB Using beam-foil spectroscopy and comparing prompt spectra (recorded close to the foil) with delayed ones we have observed the n = 4, DELTA-n = 0 spin-forbidden transitions 4s2 1S0-4s4p 3P1o in Zn-like Nb XII, 4s(2)4p 2P(o)-4s4p2 4P in Ga-like Nb XI and 4s(2)4p2 3P-4s4p3 5S(o) in Ge-like Nb X. Lifetime measurements support the spectroscopic assignments. The experimental transition probabilities for the 4s2 1S0-4s4p 3P1(0) intersystem line in the Zn I sequence are compared with the rather differenct results of various theoretical calculations. C1 UNIV LUND,DEPT PHYS,S-22362 LUND,SWEDEN. UNIV KASSEL,FACHBEREICH PHYS,W-3500 KASSEL,GERMANY. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP HECKMANN, PH (reprint author), RUHR UNIV BOCHUM,W-4630 BOCHUM 1,GERMANY. NR 29 TC 20 Z9 21 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG PY 1991 VL 44 IS 2 BP 151 EP 153 DI 10.1088/0031-8949/44/2/008 PG 3 WC Physics, Multidisciplinary SC Physics GA FY930 UT WOS:A1991FY93000008 ER PT J AU DRIESSEN, JPJ SMITH, CJ LEONE, SR AF DRIESSEN, JPJ SMITH, CJ LEONE, SR TI ALIGNMENT EFFECTS OF (J = 3) STATES PREPARED BY 3-PHOTON EXCITATION - SIXFOLD SYMMETRY IN COLLISIONAL ENERGY-TRANSFER, CA(4S4F,F-1(3)) + HE-]CA(4P2,S-1(0)) + HE SO PHYSICAL REVIEW A LA English DT Note ID IONIZATION CROSS-SECTION; ORBITAL ALIGNMENT; ASSOCIATIVE IONIZATION; MOLECULAR-STATES; ANGULAR-MOMENTUM; BEAM EXPERIMENT; CHARGE-TRANSFER; EXCITED ATOMS; RARE-GAS; SCATTERING AB Rank-6 symmetry in energy-transfer collisions is observed. A Ca(4s4f,1F3) state is prepared by three-photon excitation. The angular wave function of the Ca(1F3) state depends on the angles of the three laser polarizations with respect to each other. The alignment effect for energy transfer, Ca(4s4f,1F3) + He --> Ca(4p2,1S0)+He, is determined for two different initial angular wave functions. Each alignment curve can be analyzed in terms of the same set of relative cross sections for the individual Ca(1F3) magnetic sublevels, providing an independent verification of the data. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP NATL INST STANDARDS & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 31 TC 7 Z9 7 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD AUG 1 PY 1991 VL 44 IS 3 BP R1431 EP R1434 DI 10.1103/PhysRevA.44.R1431 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA GA169 UT WOS:A1991GA16900002 ER PT J AU BELANGER, DP MURRAY, WE MONTENEGRO, FC KING, AR JACCARINO, V ERWIN, RW AF BELANGER, DP MURRAY, WE MONTENEGRO, FC KING, AR JACCARINO, V ERWIN, RW TI NEUTRON-SCATTERING STUDY OF AN ISING ANTIFERROMAGNET ABOVE THE PERCOLATION-THRESHOLD - RANDOM-FIELD-INDUCED SPIN-GLASS-LIKE BEHAVIOR IN FE0.31ZN0.69F2 SO PHYSICAL REVIEW B LA English DT Article ID CONCENTRATION INHOMOGENEITIES; ANTI-FERROMAGNETS; RANDOM MAGNETS; SYSTEM; FE0.25ZN0.75F2; FEF2 AB Neutron-scattering studies (elastic and quasielastic) have been made on Fe0.31Zn0.69F2, both at H = 0 and in fields H less-than-or-equal-to 5 T collinear with the unique axis. (For the Fe(x)Zn(1-x)Fe2 system chi-p = 0.24). The H = 0 state exhibits antiferromagnetic (AF) long-range order (LRO) and characteristic random-exchange-Ising-model (REIM) critical behavior, but the degree of ordering is a function of the rate of cooling through the transition TN almost-equal-to 19.8 K. This is indicative of strong dynamical effects on the approach to equilibrium. Two field regions are to be distinguished. For 0 < H < 1.5 T the transition to AF LRO exhibits REIM-to-random-field-Ising-model (RFIM) crossover scaling behavior, in both the transition temperature T(c)(H) and the equilibrium boundary T(eq)(H). However, entirely new behavior is found as H increases further, unlike any previously seen at large Fe concentrations. For H > 2 T, no AF LRO is observed below T(eq)(H), which now exhibits a field scaling characteristic of the de Almeida-Thouless equilibrium boundary found in exchange-frustrated spin glasses. The observed field scaling, T(N) - T(eq)(H) almost-equal-to H2/phi, is in accord with the more precise Faraday-rotation determination of the crossover exponents phi = 1.42 and 3.4 in the respective low- (H < 1.5 T) and high- (H > 2 T) field regions. The nature of the random-field-induced spin-glass-like behavior in the region between T(c)(H) and T(eq)(H), seen here in a non-exchange-frustrated system, as manifest in its field cycling and time-dependent properties, is reported and analyzed. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20877. RP BELANGER, DP (reprint author), UNIV CALIF SANTA CRUZ,DEPT PHYS,SANTA CRUZ,CA 95064, USA. NR 24 TC 38 Z9 38 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1991 VL 44 IS 5 BP 2161 EP 2168 DI 10.1103/PhysRevB.44.2161 PG 8 WC Physics, Condensed Matter SC Physics GA GA076 UT WOS:A1991GA07600019 ER PT J AU GEHRING, PM TRANQUADA, JM SHIRANE, G COPLEY, JRD ERWIN, RW SATO, M SHAMOTO, S AF GEHRING, PM TRANQUADA, JM SHIRANE, G COPLEY, JRD ERWIN, RW SATO, M SHAMOTO, S TI MAGNETIC CORRELATIONS AND ENERGY-GAP IN SUPERCONDUCTING YBA2CU3O6.6 WITH TC=53K SO PHYSICAL REVIEW B LA English DT Note ID NEUTRON-SCATTERING; EXCITATIONS; TC AB The dynamic magnetic correlations have been characterized in a large, orthorhombic single crystal of YBa2Cu3O6+x with x = 0.6, having a T(c) of 53 K. Inelastic-neutron-scattering measurements reveal a gap (zero magnetic cross section) of 5 meV in the spin-excitation spectrum at 10 K. The size of the gap fits well between those reported by Rossat-Mignod et al. for x = 0.51 and 0.69. However, the rapid change in the gap size with a relatively small change in T(c) is not understood. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NAGOYA UNIV,NAGOYA 46401,JAPAN. RP GEHRING, PM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Gehring, Peter/0000-0002-9236-2046 NR 12 TC 32 Z9 32 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 AUG 1 PY 1991 VL 44 IS 6 BP 2811 EP 2814 DI 10.1103/PhysRevB.44.2811 PG 4 WC Physics, Condensed Matter SC Physics GA GA077 UT WOS:A1991GA07700047 ER PT J AU NEUBERG, J WAHR, J AF NEUBERG, J WAHR, J TI DETAILED INVESTIGATION OF A SPOT ON THE CORE MANTLE BOUNDARY USING DIGITAL PCP DATA SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article; Proceedings Paper CT WORKSHOP OF THE 15TH GENERAL ASSEMBLY OF THE EUROPEAN GEOPHYSICAL SOC : STUDIES OF THE EARTHS DEEP INTERIOR CY APR 23-27, 1990 CL COPENHAGEN, DENMARK SP EUROPEAN GEOPHYS SOC ID TRAVEL-TIMES; VELOCITY-STRUCTURE; AMPLITUDE RATIOS; D''; TOPOGRAPHY; EARTH; BASE AB A number of deep earthquakes from the Fiji-Tonga region were used to study the properties of the core-mantle boundary (CMB). The investigation was restricted to an area with a diameter of only a few hundred kilometers at the CMB, the use of a cluster of neighboring events yielding redundant sampling and rather good resolution. The components of the investigation are: (i) a classical stacking procedure to search for additional reflectors near the CMB; (ii) a deconvolution of seismograms and a stack of the inferred reflector series for the same purpose; (iii) a matched filter method to determine PcP travel times and PcP/P amplitude ratios precisely; and (iv) a comparison with synthetic seismograms to check the consistency of derived travel-time residuals and PcP amplitude variations in the presence of CMB topography. While we do not see any additional reflector for epicentral distances around 35-degrees, we detect by stacking seismograms recorded at 70-degrees an additional phase which might be caused by a reflection from the top of D". We show that PcP travel-time residuals must not be interpreted as being caused exclusively by CMB topography. An additional investigation of synthetics provides some constraints on dominant wavelengths and corresponding amplitudes of CMB undulations. For wavelengths of 50-400 km the elevation cannot exceed 2-3 km, if PcP is observed in this particular area. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP NEUBERG, J (reprint author), GADJAH MADA UNIV,GEOPHYS LAB,YOGYAKARTA,INDONESIA. NR 27 TC 35 Z9 35 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD AUG PY 1991 VL 68 IS 1-2 BP 132 EP 143 DI 10.1016/0031-9201(91)90013-8 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GD311 UT WOS:A1991GD31100012 ER PT J AU GARBOCZI, EJ AF GARBOCZI, EJ TI MERCURY POROSIMETRY AND EFFECTIVE NETWORKS FOR PERMEABILITY CALCULATIONS IN POROUS MATERIALS SO POWDER TECHNOLOGY LA English DT Article ID PORE SIZES; CONDUCTIVITY; PREDICTION; MEDIA; ROCK AB It is shown that a mercury porosimetry measurement can be considered as generating a mapping between a real pore structure and a random network of cyclindrical tubes. The mapping is shown to preserve the hydraulic conductivity of individual pores having elliptical cross-sections. Thus, the assumption of circular cylindrical pores, commonly used to interpret mercury porosimetry results, does not necessarily invalidate the use of these measurements to predict the permeability of porous media with the Katz-Thompson equation. A regular lattice of randomly sized tubes with elliptical cross-sections is considered as a specific test of these ideas. RP GARBOCZI, EJ (reprint author), NBS,DIV BLDG MAT,226-B348,GAITHERSBURG,MD 20899, USA. NR 19 TC 20 Z9 20 U1 1 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD AUG PY 1991 VL 67 IS 2 BP 121 EP 125 DI 10.1016/0032-5910(91)80148-C PG 5 WC Engineering, Chemical SC Engineering GA GB889 UT WOS:A1991GB88900002 ER PT J AU MALGHAN, SG MINOR, DB LUM, LSH AF MALGHAN, SG MINOR, DB LUM, LSH TI SILICON-NITRIDE POWDER MILLING KINETICS IN A HIGH-ENERGY AGITATION BALL MILL SO POWDER TECHNOLOGY LA English DT Article AB The application of high-energy agitation ball milling is described for silicon nitride powder size reduction in a specially designed system. All components of the milling system that come into contact with the powder are made of silicon nitride, and milling is carried out with hot-pressed silicon nitride media. The milling kinetics are examined by the measurement of particle size distribution and specific surface area of the milled powders as a function of milling parameters and milling liquid. Surface chemistry and impurity analysis of the powders were also carried out to determine compositional changes in the milled powder. The data of these tests demonstrate that the rotor speed has a strong effect on the milling rate and that feed rate of the slurry has an effect on the surface oxide content of the milled powders. RP MALGHAN, SG (reprint author), NBS,DIV CERAM,GAITHERSBURG,MD, USA. NR 7 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD AUG PY 1991 VL 67 IS 2 BP 201 EP 206 DI 10.1016/0032-5910(91)80156-D PG 6 WC Engineering, Chemical SC Engineering GA GB889 UT WOS:A1991GB88900010 ER PT J AU TASSEY, G AF TASSEY, G TI THE FUNCTIONS OF TECHNOLOGY INFRASTRUCTURE IN A COMPETITIVE ECONOMY SO RESEARCH POLICY LA English DT Article RP TASSEY, G (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 47 Z9 47 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-7333 J9 RES POLICY JI Res. Policy PD AUG PY 1991 VL 20 IS 4 BP 345 EP 361 DI 10.1016/0048-7333(91)90094-7 PG 17 WC Management; Planning & Development SC Business & Economics; Public Administration GA GN242 UT WOS:A1991GN24200005 ER PT J AU BUCKLEY, TJ AF BUCKLEY, TJ TI CALCULATION OF HIGHER HEATING VALUES OF BIOMASS MATERIALS AND WASTE COMPONENTS FROM ELEMENTAL ANALYSES SO RESOURCES CONSERVATION AND RECYCLING LA English DT Article AB Higher heating values on a dry basis (HHV2), measured and calculated from elemental analyses, of more than 140 biomass and waste component materials have been compared. The data were evaluated by six higher heating value formulas. The Vondracek formula was found to give the best agreement between calculated and measured heating values over a wide range (10-47 MJ/kg), judged by good linear correlation between measured and calculated HHV2 values. Standard reference materials also have been evaluated and shown generally to give good agreement. The calculation of higher healing values form elemental analyses is a good check for the reliability of a material's composition and heating value measurements in most cases. Materials with differences between calculated and measured higher heating values in excess of 6% should be considered suspect and examined closely. RP BUCKLEY, TJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-3449 J9 RESOUR CONSERV RECY JI Resour. Conserv. Recycl. PD AUG PY 1991 VL 5 IS 4 BP 329 EP 341 DI 10.1016/0921-3449(91)90011-C PG 13 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA GE908 UT WOS:A1991GE90800002 ER PT J AU KREIDER, K AF KREIDER, K TI IRIDIUM OXIDE THIN-FILM STABILITY IN HIGH-TEMPERATURE CORROSIVE SOLUTIONS SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article AB The stability of sputtered iridium oxide films is investigated after exposure to pH 4, 7, and 10 solutions at 200-degrees-C (15 bar) and 245-degrees-C (40 bar). These reactively sputtered films are being considered as pH-sensing electrodes in high-temperature high-pressure saline solutions such as those found underground in potential nuclear repositories. The sputtered iridium oxide films (SIROF) have a linear response of approximately 53-58 mV per pH at room temperature under a wide range of solution conditions. Other advantages include their ruggedness, small size, high voltage/low impedance output, and the low cost of fabrication. To evaluate their stability the films are exposed in a Teflon-lined bomb for up to 70 h at high temperature. The pH testing of 50 samples includes cycling between pH 2 and pH 12 before and after exposure. Changes of the potential intercept and the slope are most severe after acidic conditions at 250-degrees-C. It is found that ion-assisted deposition helps to maintain film adherence and continuity on the alumina substrates during exposure to 200-degrees-C solutions. RP KREIDER, K (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 7 TC 13 Z9 13 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD AUG-DEC PY 1991 VL 5 IS 1-4 BP 165 EP 169 DI 10.1016/0925-4005(91)80239-G PG 5 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA HH774 UT WOS:A1991HH77400028 ER PT J AU WU, ST SONG, MT MARTENS, PCH DRYER, M AF WU, ST SONG, MT MARTENS, PCH DRYER, M TI SHEAR-INDUCED INSTABILITY AND ARCH FILAMENT ERUPTION - A MAGNETOHYDRODYNAMIC (MHD) NUMERICAL-SIMULATION SO SOLAR PHYSICS LA English DT Article ID FREE MAGNETIC-FIELDS; LOWER SOLAR ATMOSPHERE; EULERIAN FICE SCHEME; WAVE MOTIONS; INDUCED MASS; EVOLUTION; ARCADE; FLARES; FLOWS AB We investigate, via a two-dimensional (nonplanar) MHD simulation, a situation wherein a bipolar magnetic field embedded in a stratified solar atmosphere (i.e., arch-filament-like structure) undergoes symmetrical shear motion at the footpoints. It was found that the vertical plasma flow velocities grow exponentially leading to a new type of global MHD-instability that could be characterized as a 'Dynamic Shearing Instability', with a growth rate of about square-root 8 VBAR(A)a, where VBAR(A) is the average Alfven speed and a-1 is the characteristic length scale. The growth rate grows almost linearly until it reaches the same order of magnitude as the Alfven speed. Then a nonlinear MHD instability occurs beyond this point. This simulation indicates the following physical consequences: the central loops are pinched by opposing Lorentz forces, and the outer closed loops stretch upward with the vertically-rising mass flow. This instability may apply to arch filament eruptions (AFE) and coronal mass ejections (CMEs). To illustrate the nonlinear dynamical shearing instability, a numerical example is given for three different values of the plasma beta that span several orders of magnitude. The numerical results were analyzed using a linearized asymptotic approach in which an analytical approximate solution for velocity growth is presented. Finally, this theoretical model is applied to describe the arch filament eruption as well as CMEs. C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. PURPLE MT OBSERV,NANJING,PEOPLES R CHINA. RP WU, ST (reprint author), UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899, USA. NR 27 TC 16 Z9 17 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD AUG PY 1991 VL 134 IS 2 BP 353 EP 377 DI 10.1007/BF00152653 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ917 UT WOS:A1991FZ91700009 ER PT J AU SANAHUJA, B HERAS, AM DOMINGO, V JOSELYN, JA AF SANAHUJA, B HERAS, AM DOMINGO, V JOSELYN, JA TI 3 SOLAR FILAMENT DISAPPEARANCES ASSOCIATED WITH INTERPLANETARY LOW-ENERGY PARTICLE EVENTS SO SOLAR PHYSICS LA English DT Article ID GEOMAGNETIC-ACTIVITY; SHOCKS; ERUPTIONS; PROTONS; FLARES AB Three low-energy particle events (35-1600 keV) associated with interplanetary shocks, detected at 1 AU by ISEE-3, have been identified as originating in solar disappearing filaments instead of large flares. This increases to fourteen the number of events of this kind presently known. The observational characteristics of these non-flare generated events are similar to the ones of the other eleven events already known (i.e., absence of type II or IV bursts, weak X-ray emission, H-alpha brightening in the surroundings of the filament disappearance, frequent presence of a double-ribbon event, slow propagation of the generated interplanetary shock, lack of shock deceleration). C1 EUROPEAN SPACE AGCY,EUROPEAN SPACE RES & TECHNOL CTR,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS. NOAA,ERL,SPACE ENVIRONM LAB,BOULDER,CO 80303. INST ESTUD CATALANS,ASTROFIS LAB,BARCELONA,SPAIN. RP SANAHUJA, B (reprint author), UNIV BARCELONA,DEPT ASTRON & METEOROL,BARCELONA 7,SPAIN. NR 30 TC 9 Z9 9 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD AUG PY 1991 VL 134 IS 2 BP 379 EP 394 DI 10.1007/BF00152654 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FZ917 UT WOS:A1991FZ91700010 ER PT J AU WEBB, AW KIM, KH BOULDIN, C AF WEBB, AW KIM, KH BOULDIN, C TI THE VALENCE OF COPPER IN LACUO3 - AN X-RAY ABSORPTION STUDY SO SOLID STATE COMMUNICATIONS LA English DT Article ID SUPERCONDUCTIVITY; SYSTEM AB The simplest member of the family of the perovskite-structured, Cu-based high-temperature superconductors is the rhombohedrally-distorted LaCuO3. Formal valence rules would assign the trivalent state to Cu. The X-ray near-edge structure of LaCuO3 has been studied around the copper K-edge at 8979 eV to confirm this Cu valency, using standard compounds for reference. As with La2CuO4 and YBa2Cu3O(7-y), the Cu in LaCuO3 was found to be divalent in character. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP WEBB, AW (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 9 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1991 VL 79 IS 6 BP 507 EP 508 DI 10.1016/0038-1098(91)90040-3 PG 2 WC Physics, Condensed Matter SC Physics GA GC772 UT WOS:A1991GC77200011 ER PT J AU JOYCE, SA YARMOFF, JA MADEY, TE AF JOYCE, SA YARMOFF, JA MADEY, TE TI RADIATION-DAMAGE IN AN ADSORBED MONOLAYER - PF3 ON RU(0001) SO SURFACE SCIENCE LA English DT Article ID STIMULATED-DESORPTION; COORDINATION CHEMISTRY; NEGATIVE-IONS; NI(111); CHEMISORPTION; SURFACE; PT(111) AB The chemisorption of PF3 on Ru(0001) has been studied using soft X-ray photoemission spectroscopy (SXPS) and photon stimulated desorption (PSD). The initial adsorption of PF3 on ruthenium is predominantly molecular. PF3 is found to be extremely sensitive to both electron and photon beam exposure, leading to the formation of adsorbed PF(x) fragmentation products and the desorption of fluorine. Annealing the beam-damaged overlayers results in the reformation of some adsorbed PF3. PSD ion yields at photon energies near the P 2p absorption edge show that direct photoexcitations of the adsorbed PF3 and PF2 species lead to F+ desorption. Photoexcitation of the P 2p level of an adsorbed PF unit does not lead to direct F+ emission, however. C1 NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899. RUTGERS STATE UNIV,DEPT PHYS & ASTRON,PISCATAWAY,NJ 08855. RUTGERS STATE UNIV,SURFACE MODIFICAT LAB,PISCATAWAY,NJ 08855. RI Joyce, Stephen/Q-7804-2016 OI Joyce, Stephen/0000-0003-1330-7362 NR 19 TC 18 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 254 IS 1-3 BP 144 EP 152 DI 10.1016/0039-6028(91)90646-A PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GC429 UT WOS:A1991GC42900030 ER PT J AU WESTPHAL, C BANSMANN, J GETZLAFF, M SCHONHENSE, G CHEREPKOV, NA BRAUNSTEIN, M MCKOY, V DUBS, RL AF WESTPHAL, C BANSMANN, J GETZLAFF, M SCHONHENSE, G CHEREPKOV, NA BRAUNSTEIN, M MCKOY, V DUBS, RL TI CIRCULAR-DICHROISM IN PHOTOEMISSION FROM ORIENTED MOLECULES AT SURFACES SO SURFACE SCIENCE LA English DT Article ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; ANGLE-RESOLVED PHOTOEMISSION; SYNCHROTRON RADIATION; CONTINUOUS ABSORPTION; ELECTRONIC-STRUCTURE; SPIN-POLARIZATION; PD(111) SURFACES; CROSS-SECTIONS; NO; PHOTOIONIZATION AB Measurements of a new observable quantity in photoemission from oriented molecules are reported. Using circularly polarized radiation, the photoemission intensities for a special geometry were found to depend on photon helicity. The basic theoretical description of the effect is outlined, showing that it occurs for all spatially fixed molecules in the electric dipole approximation and does not depend on electron-spin effects. Experimental case studies for diatomics (CO, NO), benzene, and the "heavy" molecule CH3I, all oriented by adsorption on Pd(111) or graphite (0001), reveal huge intensity asymmetries in all cases. Comparisons of these measured asymmetries are also made with the results of model calculations based on oriented CO, NiCO, and NO. The effect provides a sensitive probe of molecular orientation and of photoemission dynamics. C1 UNIV PARIS 11,CNRS,PHOTOPHYS MOLEC LAB,F-91405 ORSAY,FRANCE. CALTECH,ARTHUR AMOS NOYES LAB CHEM PHYS,PASADENA,CA 91125. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. LENINGRAD AVIAT INSTRUMENT MAKING INST,LENINGRAD 19000,USSR. RP WESTPHAL, C (reprint author), UNIV BIELEFELD,FAK PHYS,W-4800 BIELEFELD,GERMANY. RI Bansmann, Joachim/F-2696-2011 OI Bansmann, Joachim/0000-0003-3205-7450 NR 43 TC 41 Z9 41 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG PY 1991 VL 253 IS 1-3 BP 205 EP 219 DI 10.1016/0039-6028(91)90593-H PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA GB311 UT WOS:A1991GB31100023 ER PT J AU BRYAN, K AF BRYAN, K TI POLEWARD HEAT-TRANSPORT IN THE OCEAN - A REVIEW OF A HIERARCHY OF MODELS OF INCREASING RESOLUTION SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article; Proceedings Paper CT BOLIN-65 SYMP ON ATMOSPHERIC SCIENCES : QUO VADIMUS, IN HONOR OF PROFESSOR BERT BOLIN ON HIS 65TH BIRTHDAY AND RETIREMENT FROM STOCKHOLM UNIV CY MAY 20-23, 1990 CL STOCKHOLM, SWEDEN SP SWEDISH NAT SCI RES COUNCIL, SWEDISH COUNCIL FORESTRY & AGR RES, NATL SWEDISH ENVIRONM PROTECT BOARD, INT METEOROL INST STOCKHOLM AB The large-scale transport of heat and carbon by the ocean circulation play an important role in the Earth's climate. Progress in developing realistic models of this process is reviewed. Sufficient numerical experiments have been carried out to indicate the role of subgrid scale mixing of temperature and salinity in the transport behavior of the models. The vertical component of subgrid diffusion in the models is essential for determining the amplitude of the thermohaline circulation of the ocean. In the case of simple geometries, poleward heat transport in models is approximately proportional to vertical mixing to the two-thirds power. The horizontal component of the diffusion appears to play almost no role in the poleward transport of heat as long as the value is less than 10(3) m2/s. At low values of horizontal diffusion and viscosity, mesoscale eddies are generated spontaneously in the models through baroclinic and barotropic instability. In analogy with the atmosphere one would expect these mesoscale disturbances to play an important role in poleward heat transport. The results of numerical experiments show that this may not be the case. The mesoscale eddies in the models generate mean flows which tend to cancel the eddy fluxes in much the same way that eddy-mean flow compensation occurs for atmospheric disturbances in the lower stratosphere. RP BRYAN, K (reprint author), NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542, USA. NR 0 TC 40 Z9 42 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD AUG-SEP PY 1991 VL 43 IS 4 BP 104 EP 115 PG 12 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA GD935 UT WOS:A1991GD93500009 ER PT J AU FOGARTY, MJ SISSENWINE, MP COHEN, EB AF FOGARTY, MJ SISSENWINE, MP COHEN, EB TI RECRUITMENT VARIABILITY AND THE DYNAMICS OF EXPLOITED MARINE POPULATIONS SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Review ID DENSITY DEPENDENCE; COEXISTENCE; FISHES; LARVAE; SIZE AB Highly variable recruitment is a direct consequence of the life history strategy of many exploited marine species. High population fecundity and random variation in mortality rates during the early life stages provide the raw material for recruitment fluctuations. Determining the probable response of a population to exploitation involves understanding both the relative importance of compensatory mechanisms and the role of environmental stochasticity. Current approaches to unraveling the interactions between population-stabilizing mechanisms and sources of variability include: multidisciplinary studies of the coupling between physical and biological processes; studies of the interaction between growth and mortality during the precruit phase; examination of spatial processes and patch dynamics; and investigations of inter-individual variability. C1 NOAA,NATL MARINE FISHERIES SERV,SILVER SPRING,MD 20910. RP FOGARTY, MJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE,MA 02543, USA. NR 39 TC 165 Z9 167 U1 3 U2 36 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD AUG PY 1991 VL 6 IS 8 BP 241 EP 246 DI 10.1016/0169-5347(91)90069-A PG 6 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA FX795 UT WOS:A1991FX79500004 PM 21232469 ER PT J AU GLAZNER, AF FARMER, GL HUGHES, WT WOODEN, JL PICKTHORN, W AF GLAZNER, AF FARMER, GL HUGHES, WT WOODEN, JL PICKTHORN, W TI CONTAMINATION OF BASALTIC MAGMA BY MAFIC CRUST AT AMBOY AND PISGAH CRATERS, MOJAVE DESERT, CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID WESTERN UNITED-STATES; SOUTHERN CALIFORNIA; ISOTOPIC VARIATIONS; VOLCANIC-ROCKS; RANGE PROVINCE; MANTLE; ARIZONA; BASIN; EVOLUTION; EXTENSION AB Quaternary alkali basalts from Pisgah Crater and Amboy Crater in southern California exhibit unusual chemical and isotopic variations which probably result from assimilation of mafic crust. Although lavas from both volcanoes are alkali basalts and hawaiites with isotopic and chemical characteristics that are similar to ocean island basalts (OIB) (e.g., epsilon-Nd = 2.6 - 5.9, Sr-87/Sr-86 = 0.7038 - 0.7049, Hf/Ba = 0.014 - 0.017), they display highly correlated and unusual variations in their chemical and isotopic compositions. At each volcano, MgO decreased during the eruptive sequence from almost-equal-to 8.5 wt % to almost-equal-to 4.5 wt %. Incompatible elements are positively correlated with MgO and therefore also decreased during the eruptive sequence. Nd, Sr, and Pb isotope ratios correlate strongly with MgO. Compositional and isotopic data cannot be explained by any combination of closed-system fractionation, partial melting of the mantle, or silicic contamination. These data indicate that the basalts represent mixing between a high-MgO, high-epsilon-Nd component, common to both Pisgah and Amboy craters, with lower-MgO and -epsilon-Nd components that are unique to each center. The high-MgO component most likely is a primitive mantle-derived magma, based in part on its similarity to nearby xenolith-bearing Quaternary basalts. The low-MgO components are interpreted to be partial melts of mafic crust. If our model is correct, then both volcanoes evolved from eruption of nearly pure mantle melts early in their history to eruption of nearly pure remelted mafic crust late in their history. The crustal source could not have been underplated Mesozoic or younger oceanic crust, but its age is otherwise unconstrained; nearby Mesozoic gabbros and Proterozoic diabases have appropriate isotopic compositions. The basalt data provide no evidence that ancient enriched lithospheric mantle currently underlies the Mojave Desert. If such mantle was present at any time beneath this region, it must have been removed during one or more of the many tectonic events that affected the Mojave Desert during the Phanerozoic. Regional variability of isotope ratios in basalts is commonly interpreted to reflect variability of the underlying mantle. Data from this study raise the possibility that some of this variability may result from cryptic contamination of OIB-like basalts by mafic crust. C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. OPERAT TECHNOL CORP,MATHER AFB,CA 95655. US GEOL SURVEY,MENLO PK,CA 94025. RP GLAZNER, AF (reprint author), UNIV N CAROLINA,DEPT GEOL,CB 3315,CHAPEL HILL,NC 27599, USA. NR 74 TC 50 Z9 52 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD JUL 30 PY 1991 VL 96 IS B8 BP 13673 EP 13691 DI 10.1029/91JB00175 PG 19 WC Geosciences, Multidisciplinary SC Geology GA FY298 UT WOS:A1991FY29800026 ER PT J AU NALEPA, TF GARDNER, WS MALCZYK, JM AF NALEPA, TF GARDNER, WS MALCZYK, JM TI PHOSPHORUS CYCLING BY MUSSELS (UNIONIDAE, BIVALVIA) IN LAKE ST-CLAIR SO HYDROBIOLOGIA LA English DT Article DE NUTRIENTS; EXCRETION; BIODEPOSITION; LAMPSILIS; PHOSPHORUS BUDGET ID ENGLAND SALT-MARSH; RELEASE; BUDGET; EXCRETION; NUTRIENTS; MOLLUSCA; FLOW AB The role of mussels in cycling phosphorus in Lake St. Clair during the May-October period was examined by measuring concentrations in the water column and in mussel tissue, and by measuring rates of biodeposition and excretion. Mean rates of biodeposition and excretion for Lampsilis radiata siliquoidea, the most abundant species, were 6.3-mu-g P (g shell-free dry wt)-1 h-1 and 1.3-mu-g P (g shell-free dry wt)-1 h-1, respectively; body tissue phosphorus content was 2.7 percent of dry wt. Seasonal changes in excretion rates appeared to be related to the gametogenic cycle of the organism, but seasonal changes in biodeposition rates were not apparent. Phosphorus assimilation efficiency for this species was about 40 percent. Overall, the mussel population in Lake St. Clair filtered about 210 MT of phosphorus, or about 13.5 percent of the total phosphorus load for the May-October study period. Of this amount, about 134 MT was sedimented to the bottom via biodeposition. Mussel biodeposition may be an important source of nutrients to other biotic components in the lake such as macrophytes and invertebrate deposit-feeders. RP NALEPA, TF (reprint author), GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 36 TC 34 Z9 37 U1 0 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD JUL 26 PY 1991 VL 219 BP 239 EP 250 DI 10.1007/BF00024758 PG 12 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GK031 UT WOS:A1991GK03100016 ER PT J AU TALUKDAR, R MELLOUKI, A GIERCZAK, T BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR AF TALUKDAR, R MELLOUKI, A GIERCZAK, T BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR TI ATMOSPHERIC FATE OF CF2H2, CH3CF3, CHF2CF3, AND CH3CFCL2 - RATE COEFFICIENTS FOR REACTIONS WITH OH AND UV ABSORPTION CROSS-SECTIONS OF CH3CFCL2 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TEMPERATURE-DEPENDENCE; SUBSTITUTED METHANES; VACUUM ULTRAVIOLET; RADICAL REACTIONS; RATE CONSTANTS; KINETICS; FLUOROETHANES; SPECTRA AB The absolute rates coefficients for reactions of hydroxyl radical with four halocarbons (CH2F2(HFC-32), CH3CF3(HFC-143a), CF3CHF2(HFC-125), and CH3CFCl2(HCFC-141b)), which are potential substitutes for CFCs, were measured by using the discharge flow-laser magnetic resonance and pulsed photolysis-laser-induced fluorescence techniques between 222 and 393 K. The UV absorption cross sections for HCFC-141b between 190 and 230 nm were also measured as functions of temperature. These kinetics and cross-section data are compared with results from previous studies. These data were incorporated into a one-dimensional photochemical transport model to estimate the tropospheric and atmospheric lifetimes needed to assess the ozone depletion potential and the global warming potential of these substitutes. The atmospheric lifetime of CH3CHCl2 (HCFC-141b) is approximately 50% longer than the previously accepted value. C1 NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; McKeen, Stuart/H-9516-2013; Ravishankara, Akkihebbal/A-2914-2011; Mellouki, Abdelwahid/H-5219-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Mellouki, Abdelwahid/0000-0002-6594-5262 NR 26 TC 70 Z9 70 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1991 VL 95 IS 15 BP 5815 EP 5821 DI 10.1021/j100168a021 PG 7 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800021 ER PT J AU TAATJES, CA LEONE, SR AF TAATJES, CA LEONE, SR TI LASER DOUBLE-RESONANCE STUDIES OF LOW-TEMPERATURE ROTATIONAL AND VIBRATIONAL-RELAXATION OF HF - RATES FOR HF(J=13)+HF FROM 225-K TO 298-K AND DETECTION OF HF(V=1) DEACTIVATION BY HF CLUSTERS AT 210-240-K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID POTENTIAL-ENERGY SURFACE; MICROWAVE-SPECTRUM; INFRARED-SPECTRA; DEPENDENCE; FLUORIDE; PREDISSOCIATION; COMPLEXES; SPECTROSCOPY; COLLISIONS; (HF)N AB A variety of low-temperature vibrational and rotational relaxation phenomena in HF are studied, using a two-laser double-resonance technique. Rotational relaxation rates of HF(J = 13) with HF are measured from 225 to 298 K. Rotational relaxation rate constants for HF(J = 13) + HF range from (2.5 +/- 0.2) x 10(-10) (225 K) to (1.8 +/- 0.1) x 10(-10) (298 K) cm3 molecule-1 s-1. The negative temperature dependence of the HF(J = 13) self-relaxation is dramatic, T-1.57, similar to the previously reported temperature dependence of HF(v = 1) + HF vibrational deactivation. A model which predicts an exponential scaling of the deactivation efficiency vs the well depth of the attractive interaction is applied to the temperature dependence in order to gain insight into the relaxation mechanism. Vibrational relaxation of HF(v = 1) by collisions with (HF)n clusters at low temperatures (210-240 K) is observed by detecting the transient reduction of the concentrations in the tetramer and hexamer regions of the spectrum. Relative vibrational relaxation cross sections for HF(v = 1) with the clusters in these spectral regions are estimated. Finally, preliminary measurements are reported for relaxation of HF(J = 13) by He, Ne, and Ar between 225 and 260 K. The cross section for relaxation with He decreases with decreasing temperature, suggesting an impulsive mechanism, but the cross sections with Ne and Ar at lower temperatures are larger than at room temperature, suggesting that attractive interactions may be important in the relaxation of HF(J = 13) with Ne and Ar. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,DIV QUANTUM PHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 47 TC 11 Z9 11 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1991 VL 95 IS 15 BP 5870 EP 5877 DI 10.1021/j100168a030 PG 8 WC Chemistry, Physical SC Chemistry GA FY388 UT WOS:A1991FY38800030 ER PT J AU COALE, KH CHIN, CS MASSOTH, GJ JOHNSON, KS BAKER, ET AF COALE, KH CHIN, CS MASSOTH, GJ JOHNSON, KS BAKER, ET TI INSITU CHEMICAL MAPPING OF DISSOLVED IRON AND MANGANESE IN HYDROTHERMAL PLUMES SO NATURE LA English DT Article ID EAST PACIFIC RISE; DE-FUCA RIDGE; NORTHEAST PACIFIC; VENT FIELD; DISTRIBUTIONS; 21-DEGREES-N; CHEMISTRY; SEAWATER; FLUIDS; OCEAN AB HYDROTHERMAL vents along mid-ocean ridges are an important source of elements such as lithium, silicon, manganese and iron to the world's oceans 1. The venting produces both episodic and steady-state hydrothermal plumes with unique thermochemical signatures in the mid-water column. The particulate phases in these plumes (predominantly iron oxides and hydroxides) also scavenge phosphorus, vanadium, arsenic, lead, polonium and several rare-earth elements from sea water 2-5. Thus, on a global scale, hydrothermal plumes are both a source for some elements and a sink for others. Ultimately, the particulate metals precipitated from plumes form extensive regions of metalliferous sediments over the crests and flanks of mid-ocean ridges 6,7. Although the metalliferous sediment coverage is vast and well documented, only a tiny fraction of the vents responsible for these sediments have been located (Fig. 1a). To date, both the number and location of hydrothermal vents and the detailed distribution of chemical constituents within the resultant plumes are poorly understood because of under-sampling of the mid-ocean ridges and the overlying waters. Here we present the results of high-resolution mapping of the chemical and thermal characteristics of hydrothermal plumes in near real time using a novel submersible chemical analyser (Scanner) 8,9 and a conductivity/temperature/depth/transmissometer instrument package (CTDT) 10. We show that the kinetics of iron oxidation in the plume can be used to constrain estimates of the plume's age, and that variation in the ratio of manganese content to excess heat can be explained by the mixing of several different vent fluids. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. MONTEREY BAY AQUARIUM RES INST,PACIFIC GROVE,CA 93950. RP COALE, KH (reprint author), MOSS LANDING MARINE LABS,POB 450,MOSS LANDING,CA 95039, USA. RI Johnson, Kenneth/F-9742-2011 OI Johnson, Kenneth/0000-0001-5513-5584 NR 28 TC 54 Z9 56 U1 4 U2 23 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 25 PY 1991 VL 352 IS 6333 BP 325 EP 328 DI 10.1038/352325a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FY289 UT WOS:A1991FY28900067 ER PT J AU WU, WL KUROKAWA, H ROY, S STEIN, RS AF WU, WL KUROKAWA, H ROY, S STEIN, RS TI SMALL-ANGLE NEUTRON-SCATTERING OF POLY(VINYL ALCOHOL) GELS SO MACROMOLECULES LA English DT Article AB The structure of aqueous poly(vinyl alcohol) (PVA) gels with and without borate ions, hereafter referred to as alkaline gels and hydrogels, respectively, was investigated using small-angle neutron scattering (SANS). The correlation length xi, a measure of the wavelength of concentration fluctuation, was estimated from the SANS results. The value of xi showed a modest decrease with increasing temperature. Even at the highest temperature of observation, 95-degrees-C, xi was still a few times greater than the radius of gyration of individual PVA molecules, indicating the presence of PVA clusters in the sol state. The scattered intensities for both the hydrogels and the alkaline gels over a wide temperature range could be superimposed onto one master curve by employing the reduced variables I(q)/xi-3 and xi-q, where q is the magnitude of the scattering vector. This indicates that the concentration fluctuation can be described adequately by a single characteristic length over a wide temperature range embracing the sol-gel transition temperature. C1 KYOTO INST TECHNOL,DEPT POLYMER SCI & ENGN,SAKYO KU,KYOTO 606,JAPAN. UNIV MASSACHUSETTS,DEPT POLYMER SCI & ENGN,AMHERST,MA 01003. RP WU, WL (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 19 Z9 19 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 22 PY 1991 VL 24 IS 15 BP 4328 EP 4333 DI 10.1021/ma00015a014 PG 6 WC Polymer Science SC Polymer Science GA FY047 UT WOS:A1991FY04700014 ER PT J AU SOKOL, PE SILVER, RN SOSNICK, TR SNOW, WM AF SOKOL, PE SILVER, RN SOSNICK, TR SNOW, WM TI FINAL-STATE EFFECTS ON THE DEEP-INELASTIC RESPONSE OF LIQUID-HE-4 - COMMENT SO PHYSICAL REVIEW LETTERS LA English DT Letter ID NEUTRON-SCATTERING; MOMENTUM DISTRIBUTIONS C1 UNIV CALIF LOS ALAMOS SCI LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. UNIV CALIF LOS ALAMOS SCI LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,DIV QUANTUM METROL,GAITHERSBURG,MD 20899. RP SOKOL, PE (reprint author), PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802, USA. NR 10 TC 0 Z9 0 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 22 PY 1991 VL 67 IS 4 BP 524 EP 524 DI 10.1103/PhysRevLett.67.524 PG 1 WC Physics, Multidisciplinary SC Physics GA FX425 UT WOS:A1991FX42500030 ER PT J AU CHURNSIDE, JH MCGILLIVARY, PA AF CHURNSIDE, JH MCGILLIVARY, PA TI OPTICAL-PROPERTIES OF SEVERAL PACIFIC FISHES SO APPLIED OPTICS LA English DT Note ID WHITE REFLECTANCE STANDARD AB Reflectivity and depolarization of six species of fishes were measured using blue and green light. In general, the fish were between 15% and 25% reflective. C1 NOAA,CTR OCEAN ANAL & PREDICT,MONTEREY,CA 93943. RP CHURNSIDE, JH (reprint author), NOAA,ENVIRONM RES LABS,WAVE PROPAGAT LABS,BOULDER,CO 80303, USA. RI Churnside, James/H-4873-2013 NR 5 TC 9 Z9 10 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1991 VL 30 IS 21 BP 2925 EP 2927 PG 3 WC Optics SC Optics GA FX920 UT WOS:A1991FX92000004 PM 20706333 ER PT J AU DANIELSON, BL BOISROBERT, CY AF DANIELSON, BL BOISROBERT, CY TI ABSOLUTE OPTICAL RANGING USING LOW COHERENCE INTERFEROMETRY SO APPLIED OPTICS LA English DT Article ID MICHELSON INTERFEROMETER; CHROMATIC DISPERSION; SYSTEM; FIBER AB We describe a method for measuring submicrometer distances with an asymmetric fiber Michelson interferometer having an LED as a source of radiation. By measuring the phase slope of the Fourier components in the frequency domain, it is possible to locate the position of reflections with nanometer precision even in the presence of sample dispersion. The method is compatible with time domain sampling at the Nyquist rate which assures efficiency in data acquisition and processing. RP DANIELSON, BL (reprint author), US NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 15 TC 85 Z9 86 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1991 VL 30 IS 21 BP 2975 EP 2979 PG 5 WC Optics SC Optics GA FX920 UT WOS:A1991FX92000015 PM 20706344 ER PT J AU GOYAL, IC GALLAWA, RL GHATAK, AK AF GOYAL, IC GALLAWA, RL GHATAK, AK TI APPROXIMATE SOLUTION TO THE SCALAR WAVE-EQUATION FOR OPTICAL WAVE-GUIDES SO APPLIED OPTICS LA English DT Article ID MODES AB We consider an approximate solution to the wave equation appropriate to the optical waveguides encountered in practice. The refractive-index profile may be arbitrary, and the geometry may be two or three dimensional. A circular or a planar waveguide could thus be treated by this method. The technique is more accurate and more useful than the WKB method, which is often used in problems of this type, because the technique is valid even at the turning points, where the WKB solution fails. The fields and the propagation constants of the lowest-order modes for two profiles are calculated, and they compare well with the exact solutions. The solutions that we proposed are, in fact, not new. However, insofar as we know, they are unknown and unused by the optics community. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP GOYAL, IC (reprint author), INDIAN INST TECHNOL,DEPT PHYS,NEW DELHI 110029,INDIA. NR 7 TC 7 Z9 7 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1991 VL 30 IS 21 BP 2985 EP 2989 PG 5 WC Optics SC Optics GA FX920 UT WOS:A1991FX92000017 PM 20706346 ER EF