FN Thomson Reuters Web of Science™ VR 1.0 PT J AU RAYMOND, WH RABIN, RM WADE, GS AF RAYMOND, WH RABIN, RM WADE, GS TI EVIDENCE OF AN AGRICULTURAL HEAT-ISLAND IN THE LOWER MISSISSIPPI RIVER FLOODPLAIN SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB The Mississippi River floodplain in the states of Arkansas, Tennessee, Mississippi, and Louisiana presents a readily discernible feature in weather satellite images.This flood plain appears in the spring and early summer as a daytime warm anomaly at infrared (IR) wavelengths and as a bright reflective area at visible wavelengths. Remnants of this feature can occasionally be identified at nighttime in the IR satellite images. During June the normalized difference vegetation index identifies major contrasts between this intense agricultural region and the surrounding mixed-forest region. This distinction and the homogeneity of the floodplain, with its alluvial soil, contrast with the encircling region, creating an agricultural region containing heat island features. Thirty years of climatological surface station data for the month of June reveal that the surface air temperatures in the floodplain experience less diurnal variation than those in the surrounding regions. This is primarily because nighttime minimums are warmer in the Mississippi River floodplain. C1 NOAA, NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, MADISON, WI USA. NATL SEVERE STORMS LAB, NORMAN, OK 73069 USA. RP UNIV WISCONSIN, COOPERAT INST METEOROL SATELLITE STUDIES, MADISON, WI 53706 USA. RI Wade, Gary S./F-5630-2010 NR 23 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUN PY 1994 VL 75 IS 6 BP 1019 EP 1025 DI 10.1175/1520-0477(1994)075<1019:EOAAHI>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NU745 UT WOS:A1994NU74500006 ER PT J AU BAKER, DJ AF BAKER, DJ TI THE 74TH AMS ANNUAL-MEETING WAS HELD 23-25 JANUARY 1994 AT THE OPRYLAND-HOTEL IN NASHVILLE, TENNESSEE - KEYNOTE ADDRESS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material RP BAKER, DJ (reprint author), NOAA,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUN PY 1994 VL 75 IS 6 BP 1088 EP 1094 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NU745 UT WOS:A1994NU74500013 ER PT J AU STEVENS, BG HAAGA, JA DONALDSON, WE AF STEVENS, BG HAAGA, JA DONALDSON, WE TI AGGREGATIVE MATING OF TANNER CRABS, CHIONOECETES BAIRDI SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID RED KING CRAB; LARVAL RELEASE; SNOW CRAB; DECAPODA; MATURITY; MAJIDAE; SIZE; BEHAVIOR; RATHBUN; BRACHYURA AB In April 1991, a high-density mating aggregation of Tanner crabs, Chionoecetes bairdi, was discovered at 150 m depth near Kodiak, Alaska, with the research submersible DSRV Delta. The aggregation consisted primarily of oldshell, multiparous female crabs which formed mounds 1-2 m in diameter, 0.5-1.0 m high, and spaced at intervals of 1-2 m. Mounds contained hundreds of crabs each at densities >100.m(-2) Male crabs were found mating with females at the periphery of the aggregation, with sex ratios (male to female) varying from 1:10 to 1:100. The entire aggregation covered an area of about 2.2 ha and included approximately 100 000 crabs. No mounds were observed in May 1992, but recently spawned female crabs were found buried in the sediment at high densities (up to 2.2m(-2)) over an area of about 25 ha, suggesting that aggregation had reoccurred at the same location. Newly ovigerous females exhibited a cycle of nocturnal activity and diurnal burial whereas unmated crabs remained exposed on the sediment surface. Many body pans and presumably dead crabs were observed. We conclude that aggregative mating is a major mode of reproduction in the family Majidae. C1 ALASKA DEPT FISH & GAME,KODIAK,AK 99615. RP STEVENS, BG (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,KODIAK LAB,POB 1638,KODIAK,AK 99615, USA. NR 52 TC 35 Z9 36 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 JUN PY 1994 VL 51 IS 6 BP 1273 EP 1280 DI 10.1139/f94-127 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA PG146 UT WOS:A1994PG14600006 ER PT J AU PIERREHUMBERT, RT HELD, IM SWANSON, KL AF PIERREHUMBERT, RT HELD, IM SWANSON, KL TI SPECTRA OF LOCAL AND NONLOCAL 2-DIMENSIONAL TURBULENCE SO CHAOS SOLITONS & FRACTALS LA English DT Article ID TWO-DIMENSIONAL TURBULENCE; WAVES; INTERMITTENCY; MODEL AB We propose a family of two-dimensional incompressible fluid models indexed by a parameter alpha epsilon[0, infinity], and discuss the spectral scaling properties for homogeneous, isotropic turbulence in these models. The family includes two physically realizable members. It is shown that the enstrophy cascade is spectrally local for alpha < 2, but becomes dominated by nonlocal interactions for alpha > 2. Numerical simulations indicate that the spectral slopes are systematically steeper than those predicted by the local scaling argument. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08544. RP PIERREHUMBERT, RT (reprint author), UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637, USA. OI Pierrehumbert, Raymond/0000-0002-5887-1197 NR 15 TC 77 Z9 78 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD JUN PY 1994 VL 4 IS 6 BP 1111 EP 1116 DI 10.1016/0960-0779(94)90140-6 PG 6 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA PH065 UT WOS:A1994PH06500014 ER PT J AU DIMES, LE HAARD, NF DONG, FM RASCO, BA FORSTER, IP FAIRGRIEVE, WT ARNDT, R HARDY, RW BARROWS, FT HIGGS, DA AF DIMES, LE HAARD, NF DONG, FM RASCO, BA FORSTER, IP FAIRGRIEVE, WT ARNDT, R HARDY, RW BARROWS, FT HIGGS, DA TI ESTIMATION OF PROTEIN DIGESTIBILITY .2. IN-VITRO ASSAY OF PROTEIN IN SALMONID FEEDS SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY LA English DT Article DE PROTEIN DIGESTIBILITY; SALMONID FEEDS ID TROUT; GAIRDNERI AB The in vitro digestibility of protein in various salmonid feeds was determined by pH-stat using enzyme fractions from trout pyloric ceca. Data were compared with in vivo digestibility and growth of fish by linear regression analysis. Results indicated that there were good agreements between the degree of hydrolysis of most feed samples and growth of fish. The pH-stat method is not suited for feed samples that have been partially hydrolyzed during their preparation. C1 UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98105. NATL MARINE FISHERIES SERV,SEATTLE,WA 98105. FISHERIES & OCEANS CANADA,W VANCOUVER LAB,W VANCOUVER V7V 1N6,BC,CANADA. US FISH & WILDLIFE SERV,CTR FISH TECHNOL,BOZEMAN,MT 59715. RP DIMES, LE (reprint author), UNIV CALIF DAVIS,INST MARINE RESOURCES,DAVIS,CA 95616, USA. RI Forster, Ian/E-8098-2010 OI Forster, Ian/0000-0002-4256-4432 NR 16 TC 32 Z9 32 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0300-9629 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Physiol. PD JUN-JUL PY 1994 VL 108 IS 2-3 BP 363 EP 370 DI 10.1016/0300-9629(94)90107-4 PG 8 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA NY983 UT WOS:A1994NY98300029 ER PT J AU SQUIRES, D TABOR, S AF SQUIRES, D TABOR, S TI THE ABSORPTION OF LABOR IN INDONESIAN AGRICULTURE SO DEVELOPING ECONOMIES LA English DT Article C1 UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92103. INT SERV NAT AGR RES,THE HAGUE,NETHERLANDS. RP SQUIRES, D (reprint author), NATL MARINE FISHERIES SERV,LA JOLLA,CA, USA. NR 33 TC 1 Z9 1 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 JUN PY 1994 VL 32 IS 2 BP 167 EP 187 DI 10.1111/j.1746-1049.1994.tb00047.x PG 21 WC Economics; Planning & Development SC Business & Economics; Public Administration GA NU972 UT WOS:A1994NU97200003 ER PT J AU BROWDER, JA AF BROWDER, JA TI UNTITLED SO ECOLOGICAL ENGINEERING LA English DT Letter RP BROWDER, JA (reprint author), NOAA,NATL MARINE FISHERIES SERV,75 VIRGINIA BEACH DR,MIAMI,FL 33149, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD JUN PY 1994 VL 3 IS 2 BP 100 EP 101 DI 10.1016/0925-8574(94)90033-7 PG 2 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA NR518 UT WOS:A1994NR51800020 ER PT J AU Liggett, W AF Liggett, Walter TI Variance estimation in the EMAP strategy for sampling discrete ecological resources Discussion SO ENVIRONMENTAL AND ECOLOGICAL STATISTICS LA English DT Article C1 NIST, Gaithersburg, MD 20899 USA. RP Liggett, W (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1352-8505 EI 1573-3009 J9 ENVIRON ECOL STAT JI Environ. Ecol. Stat. PD JUN PY 1994 VL 1 IS 2 BP 150 EP 151 DI 10.1007/BF02426657 PG 2 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA V31TH UT WOS:000208905400008 ER PT J AU BRILL, RW DEWAR, H GRAHAM, JB AF BRILL, RW DEWAR, H GRAHAM, JB TI BASIC CONCEPTS RELEVANT TO HEAT-TRANSFER IN FISHES, AND THEIR USE IN MEASURING THE PHYSIOLOGICAL THERMOREGULATORY ABILITIES OF TUNAS SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE THERMOREGULATION; TEMPERATURE; SCOMBROIDEI; THUNNINI ID ALBACORE THUNNUS-ALALUNGA; BEHAVIORAL THERMOREGULATION; SKIPJACK TUNA; TEMPERATURE; BRAIN; MUSCLE; WATER AB Aerobic heat production and heat loss via the gills are inexorably linked in all water breathing teleosts except tunas. These processes are decoupled in tunas by the presence of vascular counter-current heat exchangers, and sustained (i.e., steady state) muscle temperatures may exceed water temperature by 10-degrees-C or more in larger individuals. The presence of vascular counter-current heat exchangers is not clearly advantageous in all situations, however. Mathematical models predict that tunas could overheat during strenuous activity unless the efficacy of vascular heat exchangers can be reduced, and that they may be activity limited in warmer waters. Tunas may likewise be forced out of potentially usable habitats as they grow because they have to occupy cooler waters. Vascular counter-current heat exchangers also slow rates of heating and cooling. A reduced rate of muscle temperature decrease is clearly advantageous when diving into colder water to chase prey or avoid predators. A reduced rate of heat gain from the environment would be disadvantageous, however, when fish return to the warmer surface waters. When subjected to changes in ambient temperature, tunas cannot defend a specific body temperature and do not thermoregulate in the mammalian sense. Yet when appropriately analyzed, data taken under steady state and non-steady state conditions indicate that tunas are not strictly prisoners of their own thermoconserving mechanisms. They apparently can modify overall efficiency of their vascular counter-current heat exchangers and thus avoid overheating during bouts of strenuous activity, retard cooling after diving into colder water, and rapidly warm their muscles after voluntarily entering warmer water. The exact physiological mechanisms employed remain to be elucidated. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,PHYSIOL RES LAB,LA JOLLA,CA 92093. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822, USA. NR 68 TC 52 Z9 58 U1 3 U2 22 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 JUN PY 1994 VL 40 IS 2 BP 109 EP 124 DI 10.1007/BF00002538 PG 16 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA NN692 UT WOS:A1994NN69200001 ER PT J AU LESSIOS, HA WEINBERG, JR AF LESSIOS, HA WEINBERG, JR TI GENETIC AND MORPHOLOGICAL DIVERGENCE AMONG MORPHOTYPES OF THE ISOPOD EXCIROLANA ON THE 2 SIDES OF THE ISTHMUS OF PANAMA SO EVOLUTION LA English DT Article DE GENE FLOW; GENETIC DIVERGENCE; MORPHOLOGICAL DIVERGENCE; MORPHOTYPES; RECOLONIZATION; VARIATION ID NATURAL-POPULATIONS; GEOGRAPHIC-VARIATION; TIGRIOPUS-CALIFORNICUS; LOCAL-POPULATIONS; CEPAEA-NEMORALIS; EASTERN PACIFIC; BEACH ISOPOD; ENZYME LOCI; FLOW; DIFFERENTIATION AB Excirolana braziliensis is a dioecious marine isopod that lives in the high intertidal zone of sandy beaches on both sides of Central and South America. It possesses no larval stage and has only limited means of adult dispersal. Indirect estimates of gene flow have indicated that populations from each beach exchange less than one propagule per generation. Multivariate morphometrics have discovered three morphs of this species in Panama, two of them closely related and found on opposite sides of Central America (''C morph'' in the Caribbean and ''C' morph'' in the eastern Pacific), the third found predominantly in the eastern Pacific (''P morph''). Though the P and C' morphs are seldom found on the same beach, they have overlapping latitudinal ranges in the eastern Pacific. A related species, Excirolana chamensis, has been described from the Pacific coast of Panama. Each beach contains populations that remain morphologically and genetically stable, but a single drastic change in both isozymes and morphology has been documented. We studied isozymes and multivariate morphology of 10 populations of E. braziliensis and of one population of E. chamensis. Our objective was to assess the degree of genetic and morphological variation, the correlation of divergence on these two levers of integration, the phylogenetic relationships between morphs, and the possible contributions of low vagility, low gene flow, and occasional extinction and recolonization to the genetic structuring of populations. Genetic distance between the P morph, on one hand, and the other two morphotypes off. braziliensis, on the other, was as high as the distance between E. braziliensis and E. chamensis. Several lines of evidence agree that E. chamensis and the P morph had diverged from other morphs off. braziliensis before the rise of the Panama Isthmus separated the C and C' forms, and that the P morph constitutes a different species. A high degree of genetic differentiation also exists between populations of the same morph. On the isozyme level, every population can be differentiated from every other on the basis of at least one diagnostically different locus, regardless of geographical distance or morphological affiliation. Morphological and genetic distances between populations are highly correlated. However, despite the high degree of local variation, evolution off. braziliensis as a whole has not been particularly rapid; divergence between the C and C' morphs isolated for 3 million yr by the Isthmus of Panama is not high by the standard of within-morph differentiation or by comparison with other organisms similarly separated. Alleles that are common in one population may be absent from another of the same morph, yet they appear in a different morph in a separate ocean. The high degree of local differentiation, the exclusive occupation of a beach by one genotype with rare arrival of foreign individuals that cannot interbreed freely with the residents, the genetic stability of populations with infrequent complete replacement by another genetic population, and the sharing by morphs of polymorphisms that are not shared by local populations, all suggest a mode of evolution concentrated in rare episodes of extinction and recolonization, possibly coupled with exceptional events of gene flow that help preserve ancestral variability in both oceans. C1 NATL MARINE FISHERIES SERV,POPULAT DYNAM BRANCH,WOODS HOLE,MA 02543. RP LESSIOS, HA (reprint author), SMITHSONIAN TROP RES INST,BOX 2072,BALBOA,PANAMA. NR 92 TC 35 Z9 37 U1 0 U2 4 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD JUN PY 1994 VL 48 IS 3 BP 530 EP 548 DI 10.2307/2410467 PG 19 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA PX528 UT WOS:A1994PX52800002 ER PT J AU TANIOKA, Y SATAKE, K RUFF, L GONZALEZ, F AF TANIOKA, Y SATAKE, K RUFF, L GONZALEZ, F TI FAULT PARAMETERS AND TSUNAMI EXCITATION OF THE MAY 13, 1993, SHUMAGIN ISLANDS EARTHQUAKE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEISMIC GAP; ALASKA AB The Shumagin Islands earthquake of May 13, 1993, occurred in a previously identified seismic gap where a large subduction earthquake is expected. We analyzed long-period surface waves and P waves recorded on the IRIS stations to estimate the fault parameters. The Centroid Moment Tensor solution shows that the focal mechanism is a thrust type with the strike parallel to the Aleutian trench. The seismic moment is 2.0 x 10(19) Nm and the corresponding moment magnitude is 6.8. The Moment Tensor Rate Function inversion from P waves also yields a similar focal mechanism and seismic moment. In addition, this computation provides estimates of 10 s for the duration of the source time function and 35 km for the best point source depth. These seismological analyses indicate that the fault mechanism of the 1993 earthquake was as expected, but that the magnitude was too small to fill the gap. This earthquake did not generate a tsunami large enough to be observed at the Sand Point, Alaska tide gauge or at an ocean bottom pressure gauge, at distances of 100 and 300 km, respectively. Numerical tsunami simulations result in amplitudes at both stations that are within the background noise level. Additional numerical experiments also suggest that the small tsunami amplitudes are due to the location of the source area in the shallow shelf region. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP TANIOKA, Y (reprint author), UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109, USA. RI Satake, Kenji/E-2312-2011 OI Satake, Kenji/0000-0002-3368-3085 NR 22 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 1 PY 1994 VL 21 IS 11 BP 967 EP 970 DI 10.1029/94GL00875 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NQ215 UT WOS:A1994NQ21500001 ER PT J AU PARUNGO, F LI, Z LI, XS YANG, DZ HARRIS, J AF PARUNGO, F LI, Z LI, XS YANG, DZ HARRIS, J TI GOBI DUST STORMS AND THE GREAT GREEN WALL SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTH PACIFIC-OCEAN; TRANSPORT; AEROSOL; ASIA AB Vast belts of forest planted across the northern arid lands of China, called ''The Great Green Wall, 'are probably one of the most aggressive weather modification programs in the twentieth century. The purpose is to reduce eolian transport of dust from the Gobi Desert. Preliminary data indicate a negative trend in dust-storm frequency and duration since the 1960s. Effects on atmospheric radiation and cloud microphysics appear to be statistically insignificant in the studied period. However, only time can show any long-term impact oil our environment. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. ACAD METEOROL SCI,BEIJING,PEOPLES R CHINA. RP PARUNGO, F (reprint author), NOAA,AIR RESOURCES LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 11 TC 58 Z9 60 U1 3 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 1 PY 1994 VL 21 IS 11 BP 999 EP 1002 DI 10.1029/94GL00879 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NQ215 UT WOS:A1994NQ21500009 ER PT J AU ALBUS, JS AF ALBUS, JS TI ON INTELLIGENCE AND ITS DIMENSIONS SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Editorial Material RP ALBUS, JS (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0272-1708 J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD JUN PY 1994 VL 14 IS 3 BP 60 EP 61 PG 2 WC Automation & Control Systems SC Automation & Control Systems GA PU936 UT WOS:A1994PU93600013 ER PT J AU ZINK, LR GALVAO, GP EVENSON, KM VASCONCELLOS, ECC AF ZINK, LR GALVAO, GP EVENSON, KM VASCONCELLOS, ECC TI FAR-INFRARED LASER FREQUENCIES OF (CD3OH)-C-13 SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Letter ID LINES; ASSIGNMENT AB We have measured 30 far-infrared laser frequencies of optically pumped (CD3OH)-C-13, 13 of which are new lines. The frequencies range from 0.5 to 4.9 THz with the majority between 0.75 and 1.5 THz. Two frequency stabilized CO2 lasers were used as standards for the heterodyne measurements. C1 INPE,DCT,BR-12201 S JOSE CAMPOS,SP,BRAZIL. UNICAMP,INST FIS,DEPT ELETRON QUANT,CAMPINAS,SP,BRAZIL. RP ZINK, LR (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 8 TC 5 Z9 5 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JUN PY 1994 VL 30 IS 6 BP 1361 EP 1362 DI 10.1109/3.299457 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA NY854 UT WOS:A1994NY85400003 ER PT J AU WILLIAMS, DF MARKS, RB AF WILLIAMS, DF MARKS, RB TI ON-WAFER IMPEDANCE MEASUREMENT ON LOSSY SUBSTRATES SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article AB This paper introduces a new method for measuring impedance parameters in transmission lines fabricated on lossy or dispersive dielectrics. The method, which uses an independent calibration to provide an impedance reference, compares well with conventional techniques when applied to lossless substrates. The effectiveness of the technique is illustrated for resistors fabricated on lossy silicon substrates. RP WILLIAMS, DF (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD JUN PY 1994 VL 4 IS 6 BP 175 EP 176 DI 10.1109/75.294283 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA NW048 UT WOS:A1994NW04800007 ER PT J AU CLARK, AF AF CLARK, AF TI WHERE TO FROM HERE SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Editorial Material C1 NATL INST STAND & TECHNOL,MAGNET MEASUREMENTS GRP,BOULDER,CO. CONDUCTUS INC,MAGNET RESONANCE & COMMUN TECHNOL,SUNNYVALE,CA. RP CLARK, AF (reprint author), NIST,ELECT MEASUREMENTS GRP,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1994 VL 4 IS 2 BP 50 EP 50 PG 1 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA PU040 UT WOS:A1994PU04000001 ER PT J AU GOODRICH, LF SRIVASTAVA, AN STAUFFER, TC ROSHKO, A AF GOODRICH, LF SRIVASTAVA, AN STAUFFER, TC ROSHKO, A TI HIGH-CURRENT PRESSURE CONTACTS TO AG PADS ON THIN-FILM SUPERCONDUCTORS SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article AB High current, low resistance, nonmagnetic, and nondestructive pressure contacts to Ag pads on YBa2Cu3O7-delta (YBCO) thin film superconductors were developed in this study. The contact resistance reported here includes the resistance of the current lead/Ag pad interface, the Ag pad/YBCO interface, and the bulk resistance of the contact material. This total contact resistance is the relevant parameter which determines power dissipation during critical-current measurements. It was found that regardless of the optimization of the Ag pad/YBCO interface through annealing, a pressure contact can yield a lower total resistance than a soldered contact. The lowest resistance obtained with pressure contacts was 3 mu Omega (for a 2 x 4 mm(2) contact). These contacts may be useful for many different high temperature superconductor (BTS) studies where high-current contacts with low heating are needed. RP GOODRICH, LF (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,SUPERCONDUCTOR & MAGNET MEASUREMENTS GRP,BOULDER,CO 80303, USA. NR 4 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1994 VL 4 IS 2 BP 61 EP 64 DI 10.1109/77.291692 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA PU040 UT WOS:A1994PU04000004 ER PT J AU CLAGUE, FR AF CLAGUE, FR TI A METHOD TO DETERMINE THE CALORIMETRIC EQUIVALENCE CORRECTION FOR A COAXIAL MICROWAVE MICROCALORIMETER SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB A way is presented to obtain the microcalorimeter correction factor by direct measurement rather than by an indirect estimate or modeling. The microcalorimeter is used to measure the effective efficiency of a reference standard thermistor mount. The correction factor accounts for the different thermal paths and losses in the microcalorimeter reference standard combination. The uncertainty in the measurement depends primarily on an accurate determination of the correction factor. This has been an especially difficult problem in the coaxial case because of the center conductor. The method requires the fabrication of components that duplicate the thermal and RF loss in the microcalorimeter and reference standard. Using the technique with the new National Institute of Standards and Technology (NIST) type N coaxial microcalorimeter has substantially reduced the systematic uncertainty. The total uncertainty is about one-half the uncertainty of the prior NIST standard at frequencies above 1 GHz. RP CLAGUE, FR (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 8 TC 14 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD JUN PY 1994 VL 43 IS 3 BP 421 EP 425 DI 10.1109/19.293461 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA NV969 UT WOS:A1994NV96900008 ER PT J AU MILDNER, DFR CHEN, H AF MILDNER, DFR CHEN, H TI THE NEUTRON TRANSMISSION THROUGH A CYLINDRICAL GUIDE TUBE SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID X-RAY OPTICS AB The transmission of neutrons or X-rays through a straight cylindrical channel can be determined for an input beam for which the beam divergence has azimuthal symmetry. For polar angles greater than the critical angle, the acceptance of trajectories is restricted and allowable trajectories are close to the perimeter of the channel. The distribution of available polar angles has been calculated, from which both the transmission and the beam profile as a function of distance from the end of the channel can be calculated as a function of polar angle. Since the distance between successive reflections can be determined, the number of reflections per unit length can be calculated as a function of polar angle. Hence, the distribution of the beam profile for nonperfect reflectivity can be determined. RP MILDNER, DFR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 18 TC 14 Z9 14 U1 0 U2 0 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 JUN 1 PY 1994 VL 27 BP 316 EP 325 DI 10.1107/S0021889893009847 PN 3 PG 10 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA NR330 UT WOS:A1994NR33000012 ER PT J AU READ, DT DALLY, JW AF READ, DT DALLY, JW TI ELECTRON-BEAM MOIRE STUDY OF FRACTURE OF A GLASS-FIBER-REINFORCED PLASTIC COMPOSITE SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB Using the method of electron beam moire, a small region at an interface of a [O2/90]s glass fiber reinforced plastic composite has been examined during tensile testing. The tensile test was conducted inside a scanning electron microscope, with a high spatial frequency line grating (10,000 lines/mm) at the interface between a longitudinal ply and a transverse ply. During the test, this region was observed at a magnification of 1900 x . Local strain measurements were made by interpreting the moire fringe patterns over gage lengths that varied from 10 to 30 mum. The magnitude and distribution of the local strains depended on the damage that occurred with monotonically increasing load. Load shedding by the transverse ply was evident from the fringe patterns. Extremely high local strains were observed: longitudinal fiber strains up to three percent, normal strains up to three percent, and shear strains up to 40 percent in the epoxy matrix. C1 UNIV MARYLAND,DEPT MECH ENGN,COLL PK,MD 20742. RP READ, DT (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 14 TC 23 Z9 23 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD JUN PY 1994 VL 61 IS 2 BP 402 EP 409 DI 10.1115/1.2901458 PG 8 WC Mechanics SC Mechanics GA NU630 UT WOS:A1994NU63000025 ER PT J AU HSU, SA MEINDL, EA GILHOUSEN, DB AF HSU, SA MEINDL, EA GILHOUSEN, DB TI DETERMINING THE POWER-LAW WIND-PROFILE EXPONENT UNDER NEAR-NEUTRAL STABILITY CONDITIONS AT SEA SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB On the basis of 30 samples from near-simultaneous overwater measurements by pairs of anemometers located at different heights in the Gulf of Mexico and off the Chesapeake Bay, Virginia, the mean and standard deviation for the exponent of the power-law wind profile over the ocean under near-neutral atmospheric stability conditions were determined to be 0.11 +/- 0.03. Because this mean value is obtained from both deep and shallow water environments, it is recommended for use at sea to adjust the wind speed measurements at different heights to the standard height of 10 m above the mean sea surface. An example to apply this P value to estimate the momentum flux or wind stress is provided. C1 NATL DATA BUOY CTR,BAY ST LOUIS,MS. RP HSU, SA (reprint author), LOUISIANA STATE UNIV,INST COASTAL STUDIES,BATON ROUGE,LA 70803, USA. NR 17 TC 106 Z9 109 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 1994 VL 33 IS 6 BP 757 EP 765 DI 10.1175/1520-0450(1994)033<0757:DTPLWP>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ187 UT WOS:A1994NQ18700010 ER PT J AU ANGEVINE, WM ECKLUND, WL AF ANGEVINE, WM ECKLUND, WL TI ERRORS IN RADIO ACOUSTIC SOUNDING OF TEMPERATURE SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note AB With the use of simultaneous correction for radial wind, the accuracy of radio acoustic sounding systems for the measurement of temperature has been substantially improved. The temperature accuracy can now be affected by a number of factors that have been considered negligible in previous work. This paper describes two types of errors, those due to atmospheric effects and those due to approximations in the temperature retrieval equation. The errors are examined in a set of convective boundary layer RASS and radiosonde data. In the category of atmospheric effects, two errors are computed. The first is caused by a range error due to the gradient of signal strength. This range error is newly proposed and is approximately 0.05-degrees-0.1-degrees-C. The second is an error due to wind and turbulence of about 0.1-degrees-C. Commonly used approximations for factors in the retrieval equation contribute errors of a few tenths of a degree Celsius. A significant difference remains after these two corrections have been applied to the sample data. C1 NOAA,AERON LAB,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303. RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 0 TC 33 Z9 33 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD JUN PY 1994 VL 11 IS 3 BP 837 EP 842 DI 10.1175/1520-0426(1994)011<0837:EIRASO>2.0.CO;2 PG 6 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA NM073 UT WOS:A1994NM07300019 ER PT J AU KLEIN, R JACOB, I OHARE, PAG GOLDBERG, RN AF KLEIN, R JACOB, I OHARE, PAG GOLDBERG, RN TI SOLUTION-CALORIMETRIC DETERMINATION OF THE STANDARD MOLAR ENTHALPIES OF FORMATION OF THE PSEUDOBINARY COMPOUNDS ZR(ALXFE(1-X))2 AT THE TEMPERATURE 298.15-K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID PHASE C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BEN GURION UNIV NEGEV,DEPT NUCL ENGN,BEER SHEVA,ISRAEL. NR 22 TC 23 Z9 24 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JUN PY 1994 VL 26 IS 6 BP 599 EP 608 DI 10.1006/jcht.1994.1069 PG 10 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA NP266 UT WOS:A1994NP26600006 ER PT J AU REYNOLDS, RW SMITH, TM AF REYNOLDS, RW SMITH, TM TI IMPROVED GLOBAL SEA-SURFACE TEMPERATURE ANALYSES USING OPTIMUM INTERPOLATION SO JOURNAL OF CLIMATE LA English DT Article ID THERMAL-ANALYSIS SYSTEM; SOUTHERN OSCILLATION; EL-NINO; OCEAN; AEROSOLS; WIND AB The new NOAA operational global sea surface temperature (SST) analysis is described. The analyses use 7 days of in situ (ship and buoy) and satellite SST. These analyses are produced weekly and daily using optimum interpolation (OI) on a 1-degrees grid. The OI technique requires the specification of data and analysis error statistics. These statistics are derived and show that the SST rms data errors from ships are almost twice as large as the data errors from buoys or satellites. In addition, the average e-folding spatial error scales have been found to be 850 km in the zonal direction and 615 km in the meridional direction. The analysis also includes a preliminary step that corrects any satellite biases relative to the in situ data using Poisson's equation. The importance of this correction is demonstrated using recent data following the 1991 eruptions of Mt. Pinatubo. The OI analysis has been computed using the in situ and bias-corrected satellite data for the period 1985 to present. C1 NOAA,NWS,NATL METEOROL CTR,WASHINGTON,DC 20230. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 20 TC 2142 Z9 2216 U1 12 U2 63 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUN PY 1994 VL 7 IS 6 BP 929 EP 948 DI 10.1175/1520-0442(1994)007<0929:IGSSTA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NR974 UT WOS:A1994NR97400005 ER PT J AU SMITH, TM REYNOLDS, RW ROPELEWSKI, CF AF SMITH, TM REYNOLDS, RW ROPELEWSKI, CF TI OPTIMAL AVERAGING OF SEASONAL SEA-SURFACE TEMPERATURES AND ASSOCIATED CONFIDENCE-INTERVALS (1860-1989) SO JOURNAL OF CLIMATE LA English DT Article ID STATISTICAL INTERPOLATION SCHEME; PACIFIC-OCEAN; ANOMALIES AB Optimal averaging (OA) is used to compute the area-average seasonal sea surface temperature (SST) for a variety of areas from 1860 to 1989. The OA gives statistically improved averages and the objective assignment of confidence intervals to these averages. The ability to assign confidence intervals is the main advantage of this method. Confidence intervals reflect how densely and uniformly an area is sampled during the averaging season. For the global average, the early part of the record (1860-1890) and the times of the two world wars have largest uncertainties. Analysis of OA-based uncertainty estimates shows that before 1930 sampling in the Southern Hemisphere was as good as it was in the Northern Hemisphere. From about 1930 to 1950, uncertainties decreased in both hemispheres, but the magnitude of the Northern Hemisphere uncertainties reduced more and remained smaller. After the early 1950s uncertainties were relatively constant in both hemispheres, indicating that sampling was relatively consistent over the period. During the two world wars, increased uncertainties reflected the sampling decreases over all the oceans, with the biggest decreases south of 40-degrees-S. The OA global SST anomalies are virtually identical to estimates of global SST anomalies computed using simpler methods, when the same data corrections are applied. When data are plentiful over an area there is no clear advantage of the OA over simpler methods. The major advantage of the OA over the simpler methods is the accompanying error estimates. The OA analysis suggests that SST anomalies were not significantly different from 0 from 1860 to 1900. This result is heavily influenced by the choice of the data corrections applied before the 1950s. Global anomalies are also near zero from 1940 until the mid-1970s. The OA analysis suggests that negative anomalies dominated the period from the early 1900s through the 1930s although the uncertainties are quite large during and immediately following World War I. Finally, the OA analysis shows significant positive global SST anomalies beginning in the late 1970s. The SST anomalies in the Indian Ocean and Southern Ocean poleward of 20-degrees-S make the strongest contributions to the positive glow anomalies observed since the late 1970s. In contrast to the more recent period, the SST anomalies in the period from the early 1900s through 1940 were dominated by the anomalies in the Northern Hemisphere poleward of 20-degrees-N. C1 NOAA,NWS,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20230. NOAA,NWS,NATL METEOROL CTR,COUPLED MODEL PROJECT,WASHINGTON,DC 20230. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 31 TC 61 Z9 64 U1 1 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 JUN PY 1994 VL 7 IS 6 BP 949 EP 964 DI 10.1175/1520-0442(1994)007<0949:OAOSSS>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NR974 UT WOS:A1994NR97400006 ER PT J AU BIRD, KT JEWETTSMITH, J FONSECA, MS AF BIRD, KT JEWETTSMITH, J FONSECA, MS TI USE OF IN-VITRO PROPAGATED RUPPIA-MARITIMA FOR SEAGRASS MEADOW RESTORATION SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE MICROPROPAGATION; RESTORATION; ZOSTERA MARINA; IN VITRO CULTURE; SEAGRASSES; BIOTECHNOLOGY ID INVITRO AB The use of in vitro propagated Ruppia maritima for seagrass meadow restoration was evaluated in two experiments. Experiment 1 compared two different planting methods for in vitro propagated plants. In one method, cultured plants were attached to metal staples which were then inserted into the sediment. Almost all of these transplants disappeared within one month at the four different planting sites. For the other method, in vitro propagated plants were first transferred to pest pots and groan in a flowing seawater system for six weeks. These transplants showed 20 to 80% survival. Ruppia maritima was still growing in experimental plots after 11 months at three of the four sites. There was an increase in the number of short shoots m(-2) and the percent cover. After 23 months, there was decreased cover of R, maritima and an increase in Zostera marina. In Experiment 2, R. maritima was propagated in vitro using a modified culture medium. Plants from these cultures were directly rooted ex vitro in pest pots during six weeks growth in a flowing seawater system. These planting units were transplanted to three sites. After 12 months, the experimental plots showed significant coverage of R. maritima at two sites. The other site was a more exposed location and had no R. maritima in the experimental plots from either Experiment 1 or 2, probably due to the severe winter storm of 1993. The increase in shoot numbers and areal coverage in the experimental plots suggests that R. maritima can be propagated in vitro and used successfully for habitat restoration. C1 UNIV TAMPA,DEPT BIOL,TAMPA,FL 33606. NOAA,NATL MARINE FISHERIES SERV,BEAUFORT,NC 28516. RP BIRD, KT (reprint author), UNIV N CAROLINA,MARINE SCI RES CTR,WILMINGTON,NC 28403, USA. NR 12 TC 13 Z9 15 U1 2 U2 5 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD SUM PY 1994 VL 10 IS 3 BP 732 EP 737 PG 6 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA NU689 UT WOS:A1994NU68900016 ER PT J AU CORIELL, SR BOISVERT, RF MCFADDEN, GB BRUSH, LN FAVIER, JJ AF CORIELL, SR BOISVERT, RF MCFADDEN, GB BRUSH, LN FAVIER, JJ TI MORPHOLOGICAL STABILITY OF A BINARY ALLOY DURING DIRECTIONAL SOLIDIFICATION - INITIAL TRANSIENT SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID CRYSTAL-GROWTH; INSTABILITY; INTERFACE; LIQUID AB We consider directional solidification of a binary alloy during the initial transient period in which the interface velocity, concentration, and temperature gradients are changing with time. We introduce sinusoidal perturbations of the planar crystal-melt interface and numerically calculate the time evolution of these perturbations. The results for morphological instability are in good agreement with the Mullins and Sekerka analysis of the time-independent base state if the instantaneous values of the temperature gradient and solidification velocity are used in the analysis; the agreement increases with decreasing degree of instability. C1 CEN,CEA,DTA,CEREM,DEM,SESC,F-38041 GRENOBLE,FRANCE. UNIV WASHINGTON,DEPT MAT SCI & ENGN,SEATTLE,WA 98195. RP CORIELL, SR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008; OI McFadden, Geoffrey/0000-0001-6723-2103; Boisvert, Ronald/0000-0002-4445-1044 NR 28 TC 26 Z9 26 U1 0 U2 4 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 JUN PY 1994 VL 140 IS 1-2 BP 139 EP 147 DI 10.1016/0022-0248(94)90507-X PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA NM991 UT WOS:A1994NM99100020 ER PT J AU KIM, MS MULROY, WJ DIDION, DA AF KIM, MS MULROY, WJ DIDION, DA TI PERFORMANCE EVALUATION OF 2 AZEOTROPIC REFRIGERANT MIXTURES OF HFC-134A WITH R-290 (PROPANE) AND R-600A (ISOBUTANE) SO JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrafluoroethane) with R-290 (propane) and R-600a (isobutane); R-290/134a (45/55 by mass percentage) and R-134a/600a (80/20 by mass percentage). The performance characteristics of the azeotropes were compared with pure CFC-12, HFC-134a, HCFC-22, and R-290 at the high temperature cooling and heating conditions including those using liquid-line/suction-line heat exchange. The coefficient of performance of R-290/134a is lower than that of HCFC-22 and R-290, and R-134a/600a shows higher coefficient of performance than CFC-12 and HFC-134a. The capacity for R-290/134a is higher than that for HCFC-22 and R-290, and R-134a/600a exhibits higher system capacity than CFC-12 and HFC-134a. Experimental results show that the discharge temperatures of the studied azeotropic mixtures are lower than those of the pure refrigerants, CFC-12 and HCFC-22. RP KIM, MS (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,DIV ENVIRONM,THERMAL MACHINERY GRP,GAITHERSBURG,MD 20899, USA. NR 0 TC 15 Z9 16 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0195-0738 J9 J ENERG RESOUR-ASME JI J. Energy Resour. Technol.-Trans. ASME PD JUN PY 1994 VL 116 IS 2 BP 148 EP 154 DI 10.1115/1.2906020 PG 7 WC Energy & Fuels SC Energy & Fuels GA NT464 UT WOS:A1994NT46400009 ER PT J AU COFFEY, HE AF COFFEY, HE TI GEOMAGNETIC AND SOLAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article RP COFFEY, HE (reprint author), NOAA,CTR WORLD DATA SOLAR TERRESTRIAL PHYS A,BOULDER,CO 80302, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1994 VL 99 IS A6 BP 11347 EP 11350 DI 10.1029/94JA01109 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NP993 UT WOS:A1994NP99300035 ER PT J AU SCHADT, RJ ENGLISH, AD AF SCHADT, RJ ENGLISH, AD TI ACOUSTIC RINGING IN NMR RF CIRCUITS SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Note ID H-2 NMR; DYNAMICS C1 DUPONT CO INC,CENT RES & DEV,EXPTL STN,WILMINGTON,DE 19880. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 12 TC 4 Z9 4 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 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD JUN PY 1994 VL 108 IS 2 BP 244 EP 247 DI 10.1006/jmra.1994.1118 PG 4 WC Physics, Atomic, Molecular & Chemical SC Physics GA NT496 UT WOS:A1994NT49600016 ER PT J AU GLAZIER, SA WEETALL, HH AF GLAZIER, SA WEETALL, HH TI AUTOFLUORESCENCE DETECTION OF ESCHERICHIA-COLI ON SILVER MEMBRANE FILTERS SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE AUTOFLUORESCENCE; EPIFLUORESCENCE; ESCHERICHIA COLI ID BACTERIA; ENUMERATION AB This report describes the measurement of the limit of detection of the bacterium, Escherichia coli, on the surface of membrane filters employing autofluorescence. Investigation of detection of E. coli by this method was prompted by NASA's need for a method which could detect, principally, fecal coliforms in initially sterile storage water on-board the space station. This method was examined, with E. coli as a model, because it could be conducted rapidly with little or no need for disposables, large amounts of instrumentation, or constant human involvement. The autofluorescence of E. coli collected on the surface of silver membrane filters was quantitated by epifluorescence microscopy and related to a viable count of the bacteria. The fluorescence was excitated using a broad region of ultraviolet radiation from a mercury are lamp (approx. 250-400 nm) and examined in the wavelength region of 495 nm and higher through a long pass optical filter. From these measurements, the limit of detection of viable E. coli collected on the membrane filters was fewer than 550+/-32 viable bacteria or 170,000+/-10,000/ml in terms of solution concentration. RP GLAZIER, SA (reprint author), NIST,DIV BIOTECHNOL,BLDG 222,RM A353,GAITHERSBURG,MD 20899, USA. NR 13 TC 13 Z9 16 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD JUN PY 1994 VL 20 IS 1 BP 23 EP 27 DI 10.1016/0167-7012(94)90060-4 PG 5 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA NN257 UT WOS:A1994NN25700003 ER PT J AU TIMUS, DM HUBBELL, JH KALLA, SL AF TIMUS, DM HUBBELL, JH KALLA, SL TI ACTIVITY CHARACTERIZATION OF THIN SAMPLES MOVING IN FRONT OF DISK-SHAPED ISOTROPICALLY EMITTING SOURCES SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE ISOTROPICALLY EMITTING SOURCES; RADIOACTIVITY; ACTIVATION ANALYSIS; RADIATION DOSES; RADIATION FIELD; RADIATION FLUX DENSITY; ELLIPTIC INTEGRALS; SERIES EXPANSION AB The paper deals with the activity acquired by an element of target area moving parallel to a flat disk-shaped source isotropically emitting in nondispersive media. Some particular cases of motion are theoretically investigated in order to establish analytically the activity acquired in given irradiation periods. C1 INST ATOM PHYS, BUCHAREST, ROMANIA. NATL INST STAND & TECHNOL, CTR RADIAT RES, DIV IONIZING RADIAT, GAITHERSBURG, MD 20899 USA. UNIV ZULIA, FAC INGN, CTR INVEST MATEMAT APLICADA, MARACAIBO, VENEZUELA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD JUN PY 1994 VL 31 IS 6 BP 590 EP 595 DI 10.1080/18811248.1994.9735194 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PA450 UT WOS:A1994PA45000011 ER PT J AU LIU, ZY AF LIU, ZY TI A SIMPLE-MODEL OF THE MASS-EXCHANGE BETWEEN THE SUBTROPICAL AND TROPICAL OCEAN SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID EQUATORIAL UNDERCURRENT; VENTILATED THERMOCLINE; PACIFIC; CIRCULATION; TRITIUM AB A simple ventilated thermocline model is used to study the subtropical-tropical mass exchange. It is found that the water subducted in the western subtropical gyre (recirculating window) tends to recirculate within the subtropical gyre, while the water subducted in the eastern part (exchange window) tends to penetrate equatorward. The exchange window expands with an increased easterly wind or basin width on the southern boundary of the subtropical gyre, but shrinks with an increased wind curl within the subtropical gyre. Furthermore, the total exchange transport increases with the easterly wind or the width of the basin on the southern boundary of the subtropical gyre, but it is independent of subtropical wind. The ventilation mechanism is important in supporting the exchange transport. For wind with realistic strength at the southern boundary, the reduction of the exchange transport is about 15%-30% of the Ekman transport. Finally, relative to the exchange transport in the interior of the ocean, the exchange transport through the low-latitude western boundary current decreases with increased total exchange transport. C1 PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,UCAR VISITING SCIENTIST PROGRAM,PRINCETON,NJ 08544. NR 20 TC 67 Z9 71 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUN PY 1994 VL 24 IS 6 BP 1153 EP 1165 DI 10.1175/1520-0485(1994)024<1153:ASMOTM>2.0.CO;2 PG 13 WC Oceanography SC Oceanography GA NT492 UT WOS:A1994NT49200005 ER PT J AU YOON, H FENG, Y QIU, Y HAN, CC AF YOON, H FENG, Y QIU, Y HAN, CC TI STRUCTURAL STABILIZATION OF PHASE-SEPARATING PC POLYESTER BLENDS THROUGH INTERFACIAL MODIFICATION BY TRANSESTERIFICATION REACTION SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE POLYMER BLEND; PHASE SEPARATION; TRANSESTERIFICATION; INTERFACIAL STRUCTURE ID ANGLE NEUTRON-SCATTERING; TRANS-ESTERIFICATION; SPINODAL DECOMPOSITION; POLYCARBONATE BLENDS; POLY(ETHYLENE-TEREPHTHALATE); MIXTURES; DYNAMICS; MISCIBILITY; BISPHENOL; POLYMERS AB Competition between phase separation and transesterification in immiscible polymer blends of polycarbonate (PC) and a copolyester (PET) is studied as a function of time and temperature by differential scanning calorimetry (DSC) and small-angle neutron scattering (SANS). We found that (1) Global structure coarsens at T less-than-or-equal-to 200-degrees-C due to the dominance of phase separation over transesterification and melts at T greater-than-or-equal-to 220-degrees-C due to the dominance of transesterification at the domain interface. However, transesterification is slow but still significant even at T less-than-or-equal-to 200-degrees-C. (2) An intricate balance of transesterification and phase separation rates controls global and interfacial structures. (3) Interfacial structures become measurable under certain conditions, and the interfacial thickness between PC or PET and the copolymers generated by transesterification increases with time. (4) DSC results are consistent with results obtained by SANS, but the latter is more sensitive than the former and differentiates the structural change at different length scales caused by phase separation and transesterification. (C) 1994 John Wiley & Sons, Inc. C1 E CHINA UNIV CHEM TECHNOL,DEPT POLYMER SCI & ENGN,SHANGHAI,PEOPLES R CHINA. RP YOON, H (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 27 TC 34 Z9 35 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD JUN PY 1994 VL 32 IS 8 BP 1485 EP 1492 DI 10.1002/polb.1994.090320820 PG 8 WC Polymer Science SC Polymer Science GA NM081 UT WOS:A1994NM08100020 ER PT J AU PALUCH, IR LENSCHOW, DH SIEMS, S MCKEEN, S KOK, GL SCHILLAWSKI, RD AF PALUCH, IR LENSCHOW, DH SIEMS, S MCKEEN, S KOK, GL SCHILLAWSKI, RD TI EVOLUTION OF THE SUBTROPICAL MARINE BOUNDARY-LAYER - COMPARISON OF SOUNDINGS OVER THE EASTERN PACIFIC FROM FIRE AND HARP SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DIURNAL-VARIATION; STRATOCUMULUS LAYER; EQUATORIAL PACIFIC; RADIATIVE-TRANSFER; HIGH-SENSITIVITY; MODEL; CLOUD; OZONE; BUDGETS AB The mean time rates of change of temperature, total water mixing ratio and ozone along airflow trajectories in the lower troposphere over the eastern Pacific are inferred by comparing aircraft soundings from the First ISCCP Regional Experiment (FIRE) and the Hawaiian Rainband Project (HaRP). Through the use of the estimated mean fluxes of temperature and total water mixing ratio, it is found that the tendency for stratus layers to grow or dissipate is very sensitive to the assumed turbulence structure below the capping inversion. A mixed-layer model that assumes a well-mixed boundary layer up to the capping inversion predicts a solid cloud layer extending all the way to Hawaii, whereas a model that allows decoupling predicts rapid dissipation of the stratus layer. It is concluded that stratus dissipation here is due to the slowdown of turbulent mixing throughout the layer below the capping inversion, not the drying out of a well-mixed layer; hence, the mixed-layer model cannot be expected to predict realistic cloud dissipation. The differences in ozone concentration observed in the boundary layer during HaRP and FIRE suggest a chemical loss of ozone of 3-8 ppb day-1, corresponding to a lifetime of 3-9 days. This implies that ozone cannot be treated as a conserved tracer when dealing with ozone budgets over periods of days. The ozone sink is probably of photochemical origin, and it requires further investigation. C1 NOAA, BOULDER, CO 80303 USA. RP NATL CTR ATMOSPHER RES, MMM, POB 3000, BOULDER, CO 80307 USA. RI Siems, Steven/C-8339-2013; McKeen, Stuart/H-9516-2013 NR 38 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUN 1 PY 1994 VL 51 IS 11 BP 1465 EP 1479 DI 10.1175/1520-0469(1994)051<1465:EOTSMB>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ997 UT WOS:A1994NQ99700009 ER PT J AU GROSS, BD AF GROSS, BD TI FRONTAL INTERACTION WITH ISOLATED OROGRAPHY SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID LEE CYCLOGENESIS; COLD SURGES; FRONTOGENESIS; ATMOSPHERE; PROPAGATION; MOUNTAINS; FEATURES; RIDGES; FLOW; ALPS AB The interaction of a three-dimensional cold front and an isolated orographic ridge is examined by means of primitive equation model simulations. The front evolves as part of a developing nonlinear baroclinic wave and propagates southward toward the ridge. Many of the features in this interaction, such as the anticyclonic distortion of the front, divergence and frontolysis on the windward slope, convergence and frontogenesis in the lee, and the frontogenetical forcing associated with tilting, have previously been captured by simulations of a passive scalar traversing a ridge. It is shown that the ridge decelerates the cold postfrontal air and creates a high pressure anomaly on the windward slope. If this anomaly is strong enough, it accelerates air over the ridge peak in a shallow ageostrophic flow that possesses many features found in a gravity current. This current provides relatively strong surface frontogenesis through the convergence term, but cannot transport enough mass across the peak to weaken the anomalous high pressure. The cold air and pressure anomaly propagate eastward in a manner similar to a topographic Rossby wave. When the cast ridge end is reached, the anomalous pressure gradient accelerates the flow into the lee, where frontogenesis occurs from shearing. The motion behind the front as it propagates over and around the ridge is distinctly unbalanced. Blocking, as measured by the ratio of the mass flux around the ridge end to that over the peak, is determined by a Froude number that depends on the propagation speed of the front (i.e., the strength of the baroclinic wave) and the mountain height. Higher mountains or weaker waves tend to produce total blocking of the front, resulting in flow only around the cast ridge end. Lower mountains and stronger waves produce frontogenesis patterns and frontal distortions that more closely resemble the passive scalar simulations. C1 PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08544 USA. NR 37 TC 22 Z9 24 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUN 1 PY 1994 VL 51 IS 11 BP 1480 EP 1496 DI 10.1175/1520-0469(1994)051<1480:FIWIO>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ997 UT WOS:A1994NQ99700010 ER PT J AU COLLINS, BL AF COLLINS, BL TI BIOLOGICAL EFFECTS OF ARCHITECTURAL LIGHTING AND THEIR ASSOCIATED ENERGY-UTILIZATION - DISCUSSION SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Note RP COLLINS, BL (reprint author), NATL INST STAND & TECHNOL,WASHINGTON,DC 20234, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1994 VL 23 IS 2 BP 39 EP 39 PG 1 WC Optics SC Optics GA NW827 UT WOS:A1994NW82700021 ER PT J AU LIEBMANN, B HENDON, HH GLICK, JD AF LIEBMANN, B HENDON, HH GLICK, JD TI THE RELATIONSHIP BETWEEN TROPICAL CYCLONES OF THE WESTERN PACIFIC AND INDIAN OCEANS AND THE MADDEN-JULIAN OSCILLATION SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID 40-50 DAY OSCILLATION; INTRASEASONAL VARIATIONS AB We document a relationship between tropical cyclones of the Indian and western Pacific oceans and the Madden-Julian oscillation (MJO). Cyclones preferentially occur during the convective phase of the oscillation, and cluster around the low-level cyclonic vorticity and divergence anomalies that appear poleward and westward of the large-scale convective anomaly along the equator. Although the absolute numbers of storms and typhoons are enhanced during the convective phase of the oscillation, the ratios of storms and typhoons formed per depression are the same in the convective phase as the dry phase of the oscillation. There exist more storms and typhoons simply by there being more depressions in the convective phase. The third result of this study is that the increase in cyclone activity during active periods of convection is not restricted to MJO activity. In fact, we find that an equal increase occurs during the convective phase of an arbitrarily chosen, completely independent band from the MJO. We conclude that the MJO does not influence tropical cyclones in a unique fashion, but it is important because of the relatively large proportion of tropical variance that is explained by: it. C1 UNIV COLORADO, PROGRAM ATMOSPHER & OCEAN SCI, BOULDER, CO 80309 USA. RP LIEBMANN, B (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, CAMPUS BOX 449, BOULDER, CO 80309 USA. NR 18 TC 246 Z9 280 U1 6 U2 23 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 EI 2186-9057 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD JUN PY 1994 VL 72 IS 3 BP 401 EP 412 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PB519 UT WOS:A1994PB51900004 ER PT J AU CHILDERS, DL SKLAR, FH HUTCHINSON, SE AF CHILDERS, DL SKLAR, FH HUTCHINSON, SE TI STATISTICAL TREATMENT AND COMPARATIVE-ANALYSIS OF SCALE-DEPENDENT AQUATIC TRANSECT DATA IN ESTUARINE LANDSCAPES SO LANDSCAPE ECOLOGY LA English DT Article DE ESTUARIES; COASTAL LANDSCAPES; AQUATIC TRANSECT DATA; COMPARATIVE STATISTICS; ANCOVA; FLOATING WINDOW; VARIABLE SCALE ANALYSIS AB Estuarine ecosystem dynamics have evolved around and respond to landscape-level influences that are dynamic in space and time. The estuarine water column is effectively the physical and biologial integrator of these landscape inputs. In this paper, we present a floating window Analysis of Covariance (ANCOVA) technique to statistically compare and contrast aquatic transect data that were taken at different times and under different tidal conditions, yet were geographically parallel and spatially articulate. The floating window ANCOVA compared two transects by testing whether the means of the dependent variable were significantly different while also testing whether the slopes of patterns in the dependent variable were significantly different. By varying the size of the floating window where the ANCOVA was run, we were able to examine how scale affected the magnitude and spatial pattern of that variable. The percentages of total models run, at a given window size, that generated significantly different magnitudes (means) and patterns (slopes) in the dependent variable were referred to as the ''degree of dissimilarity''. Plots of window size versus degree of dissimilarity elucidated temporal and spatial variability in water column parameters at a range of scales. The advantages of this new statistical method in relation to traditional spatial statistics are discussed. We demonstrated the efficacy of the floating window ANCOVA method by comparing chlorophyll and salinity transect data taken at the North Inlet, SC estuary during flooding and ebbing tides in Winter, Spring, and Summer 1991. Chlorophyll concentrations represented the biological characteristics of the estuarine water column and salinity represented the physical processes affecting that water column. We found total dissimilarity in the magnitude of salinity data from one season to the next at all scales, but inter-seasonal similarity in spatial patterns over both short (hourly) and long (monthly) time scales. We also found a large seasonal dissimilarity in the magnitude of chlorophyll levels, as expected. Spatial patterns in phytoplankton biomass (as chlorophyll concentrations) appeared to be largely controlled by the physical processes represented with the salinity data. Often, we observed greater dissimilarity in biological and physical parameters from one tide to the next [on a given day] than from one season to the next. In these cases, the greatest flood-ebb differences were associated with landscape-level influences - from rivers and the coastal ocean - that varied greatly with direction of tidal flow. We are currently using spatially articulate aquatic transect data and the floating window ANCOVA technique to validate spatial simulation models at different scales. By using this variable-scale statistical technique to determine coherence between the actual transect data and model output from simulations run at different scales, we will test hypotheses about the scale-dependent relationships between data resolution and model predictability in landscape analysis. RP CHILDERS, DL (reprint author), NATL MARINE FISHERIES SERV,SE FISHERY SCI CTR,GALVESTON LAB,4700 AVE U,GALVESTON,TX 77551, USA. NR 0 TC 8 Z9 8 U1 0 U2 2 PU S P B ACADEMIC PUBLISHING BV PI LELYSTAD PA PLATINASTRAAT 33, 8211 AR LELYSTAD, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD JUN PY 1994 VL 9 IS 2 BP 127 EP 141 PG 15 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA NU094 UT WOS:A1994NU09400005 ER PT J AU RADFORD, SF GRAN, RL MILLER, RV AF RADFORD, SF GRAN, RL MILLER, RV TI DETECTION OF WHALE WAKES WITH SYNTHETIC-APERTURE RADAR SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article ID SURFACE AB Synthetic aperture radar (SAR) imagery obtained near Santa Cruz Island demonstrates the capability of SAR to detect surface wakes produced by whales. The data was taken by the Navy's P-3 XLC SAR during the January 1989 gray whale southward migration during low winds and under calm, surface-slicked sea conditions. A SAR image at L-Band shows several distinct wakes, with local signal-to-clutter ratios as large as 35 dB, while a simultaneous C-Band image shows no such features. Known whale migratory behavior, data analysis, and theoretical modeling are used to propose and investigate reasonable hypotheses for the wake generating mechanism, the nature of the wake phenomena, and the radar imaging mechanisms. We suggest that the wakes represent whale-generated surface waves produced by the whale's fluke thrusts. Each upward thrust creates a turbulent vortex which, a few seconds later, impacts the ocean surface. The radar scattering Bragg wavelength surface waves thus form a narrow-upsilon pattern like those previously seen in SAR images of ship wakes. The potential utility of SAR for monitoring future gray whale migrations, as well as more general whale monitoring activities, is discussed. Further experiments are proposed. C1 NATL MARINE MAMMAL LAB,SEATTLE,WA. RP RADFORD, SF (reprint author), DYNAM TECHNOL INC,ARLINGTON,VA, USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1994 VL 28 IS 2 BP 46 EP 52 PG 7 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA PQ197 UT WOS:A1994PQ19700007 ER PT J AU CAHN, JW AF CAHN, JW TI THE EXPANDING SCOPE OF THERMODYNAMICS IN PHYSICAL METALLURGY SO MATERIALS TRANSACTIONS JIM LA English DT Article DE THERMODYNAMICS; SURFACES; DIFFUSE INTERFACES; SURFACE STRESS; CRYSTALLINE SOLIDS; STRESS; CHEMICAL POTENTIAL; DIFFUSION POTENTIAL; VACANCIES; DIFFUSIONAL CREEP ID INTERFACE; SOLIDS AB Some recent developments in the applications of thermodynamics to problems is physical metallurgy have required adaptation that are in the inventive spirit of classical thermodynamics. Diffuse interfaces and the problems that crystal lattices pose are taken as examples. RP CAHN, JW (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 29 TC 0 Z9 0 U1 1 U2 3 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD JUN PY 1994 VL 35 IS 6 BP 377 EP 383 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NZ556 UT WOS:A1994NZ55600002 ER PT J AU REYNOLDS, CA WEBSTER, PJ KALNAY, E AF REYNOLDS, CA WEBSTER, PJ KALNAY, E TI RANDOM ERROR GROWTH IN NMC GLOBAL FORECASTS SO MONTHLY WEATHER REVIEW LA English DT Article ID TROPICAL EXTRATROPICAL INTERACTION; NATIONAL-METEOROLOGICAL-CENTER; NUMERICAL WEATHER PREDICTION; VARYING BASIC STATE; DYNAMICAL PREDICTABILITY; INTERANNUAL VARIABILITY; MODEL; CIRCULATION; OSCILLATION; BLOCKING AB The three-dimensional structure of random error growth in the National Meteorological Center's Medium-Range Forecast Model is investigated in an effort to identify the sources of error growth. The random error growth is partitioned into two types: external error growth, which is due to model deficiencies, and internal error growth, which is the self-growth of errors in the initial conditions. Forecasts from winter 1987, summer 1990, and winter 1992 are compared to assess seasonal variations in regional error growth as well as forecast model improvement. The following is found: In the tropics, large external error growth at the 200-mb level is closely associated with deep convection. There is evidence of significant model improvements in the tropics at the 850-mb level between 1987 and 1992. The spatial structure of the external error growth in the midlatitudes suggests that the representation of orography in the model, especially over Antarctica and the Rockies, is a significant source of errors. Internal error growth in the midlatitudes is greater over the Atlantic and European regions than over the Pacific region and appears to be associated with blocking phenomena, especially over the North Atlantic and Europe. The Northern Hemisphere exhibits a seasonal cycle in the magnitude of error growth, but the Southern Hemisphere does not. The results for the external and internal error growth rates were obtained using a parameterization of the correlation between forecasts and the verifying analyses. The parameterization is based on the assumption that linear random error growth is caused primarily by model deficiencies, and the validity of this assumption is examined. The results suggest that, in the tropics, significant increases in forecast skill may be obtainable through both model and analysis improvement. In the midlatitudes, however, there is less potential for increases in forecast skill through model improvement, and decreasing the analysis error becomes more important. The parameterization yields results that are physically meaningful and in agreement with previous predictability studies, and that provide quantitative estimates of the spatial and temporal distribution of the sources of forecast errors. C1 UNIV COLORADO,PROGRAM ATMOSPHER & OCEAN SCI,BOULDER,CO 80309. NOAA,NWS,NAT METEOROL CTR,DIV DEV,WASHINGTON,DC 20230. RI Kalnay, Eugenia/F-4393-2010; OI Reynolds, Carolyn/0000-0003-4690-4171; Kalnay, Eugenia/0000-0002-9984-9906 NR 50 TC 70 Z9 77 U1 1 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 JUN PY 1994 VL 122 IS 6 BP 1281 EP 1305 DI 10.1175/1520-0493(1994)122<1281:REGING>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ156 UT WOS:A1994NQ15600016 ER PT J AU KUMAR, A AF KUMAR, A TI DYNAMIC NORMAL-MODE INITIALIZATION FOR LIMITED-AREA MODELS - GENERALIZATION AND APPLICATION SO MONTHLY WEATHER REVIEW LA English DT Article ID NUMERICAL WEATHER PREDICTION; CLOUD CLUSTERS; SPECTRAL MODEL; PRECIPITATION; SCHEME; CIRCULATION; TIME; HEAT AB For the dynamic normal-mode initialization (DNMI) procedure used in the initialization of the limited-area models, it is shown that it does not succeed in initializing higher vertical modes. An improved initialization procedure where the DNMI is performed in the vertical mode space is next formulated. A comparison of the two initialization schemes demonstrates that with the new procedure the initialization of the higher vertical modes can be better accomplished. The need for a better initialization method for limited-area models is prompted by the fact that if the assimilation of the observed estimates of the convective heating toward enhancing the analysis of the divergence is to be achieved, higher vertical modes have to be properly initialized. It is shown that the improved DNMI procedure does succeed in the assimilation of the convective heating information. RP KUMAR, A (reprint author), NOAA,NWS,NATL METEOROL CTR,COUPLED MODEL PROJECT,5200 AUTH RD,ROOM 807,CAMP SPRINGS,MD 20746, USA. NR 36 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1994 VL 122 IS 6 BP 1351 EP 1363 DI 10.1175/1520-0493(1994)122<1351:DNMIFL>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ156 UT WOS:A1994NQ15600020 ER PT J AU KLINEDINST, DB MCNICHOL, AP CURRIE, LA SCHNEIDER, RJ KLOUDA, GA VONREDEN, KF VERKOUTEREN, RM JONES, GA AF KLINEDINST, DB MCNICHOL, AP CURRIE, LA SCHNEIDER, RJ KLOUDA, GA VONREDEN, KF VERKOUTEREN, RM JONES, GA TI COMPARATIVE-STUDY OF FE-C BEAD AND GRAPHITE TARGET PERFORMANCE WITH THE NATIONAL-OCEAN-SCIENCE-AMS (NOSAMS) FACILITY RECOMBINATOR ION-SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; MICROGRAM SAMPLES; C-14 AB An accelerator mass spectrometry (AMS) experiment was designed to investigate C-14 target performance for two target types over a range of isotopic concentrations and sample sizes, with a special focus on the ability to measure C-14 in environmental samples having only microgram amounts of carbon. The findings were positive, showing that precision, accuracy, and stability were adequate to determine C-14 to 1% or better in samples containing as little as 25 mug carbon. Satisfactory Poisson uncertainty and target stability were demonstrated down to a level of 7 mug carbon, but experimental data showed that accurate measurements at that level require detailed knowledge of blank variability and mass dependence of the modern carbon calibration factor. C1 WOODS HOLE OCEANOG INST, NATL OCEAN SCI ACCELERATOR MASS SPECTROMETRY FACIL, WOODS HOLE, MA 02543 USA. RP KLINEDINST, DB (reprint author), NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. OI von Reden, Karl/0000-0001-6413-9018 NR 13 TC 23 Z9 23 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1994 VL 92 IS 1-4 BP 166 EP 171 DI 10.1016/0168-583X(94)95999-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NV547 UT WOS:A1994NV54700038 ER PT J AU CURRIE, LA AF CURRIE, LA TI OPTIMAL ESTIMATION OF UNCERTAINTY INTERVALS FOR ACCELERATOR AND DECAY COUNTING SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 6th International Conference on Accelerator Mass Spectrometry (AMS-6) CY SEP 27-OCT 01, 1993 CL CANBERRA, AUSTRALIA SP ALPHATECH INT, NEW ZEALAND, APPLICAT NUCL PHYS, ANSTO, SYDNEY, AUSTR TOURIST COMMISS, CRYOLAB, AUSTR, CSIRO, DIV EXPLORAT & MINING, SYDNEY, DEPT IND TRADE & COMMERCE AUSTR, AUSTR NATL UNIV, DEPT NUCL PHYS, CANBERRA, DIGITAL EQUIPMENT CORP, AUSTR, EG&G ORTEC NUCLETRON, AUSTR, HIGH VOLTAGE ENGN EUROPA BV, MICRO ANAL RES CTR, MELBOURNE, NATL ELECTROSTAT CORP, USA ID FACILITY AB Uncertainty concerning uncertainties reported by various investigators for counting experiments sometimes makes it difficult to assess the real meaning of experimental results, such as radiocarbon ages. Utilization of the maximum variance rule, which takes into account knowledge of counting error, has a major advantage in avoiding excessively small confidence intervals, but it leads to biased variance estimates and overly conservative confidence intervals. An assessment is given of the strengths and weaknesses of four alternatives, one of which ''the variance weighted t'' is asymptotically correct (negligible Poisson error) and is particularly attractive when Poisson error is dominant. Extension to the case where Poisson error is not the dominant, known random error component, shows that the methods presented can be generalized for non-counting experiments. RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 7 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1994 VL 92 IS 1-4 BP 188 EP 193 DI 10.1016/0168-583X(94)96003-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NV547 UT WOS:A1994NV54700042 ER PT J AU CURRIE, LA KLOUDA, GA KLINEDINST, DB SHEFFIELD, AE JULL, AJT DONAHUE, DJ CONNOLLY, MV AF CURRIE, LA KLOUDA, GA KLINEDINST, DB SHEFFIELD, AE JULL, AJT DONAHUE, DJ CONNOLLY, MV TI FOSSIL-MASS AND BIO-MASS COMBUSTION - C-14 FOR SOURCE IDENTIFICATION, CHEMICAL TRACER DEVELOPMENT, AND MODEL VALIDATION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 6th International Conference on Accelerator Mass Spectrometry (AMS-6) CY SEP 27-OCT 01, 1993 CL CANBERRA, AUSTRALIA SP ALPHATECH INT, NEW ZEALAND, APPLICAT NUCL PHYS, ANSTO, SYDNEY, AUSTR TOURIST COMMISS, CRYOLAB, AUSTR, CSIRO, DIV EXPLORAT & MINING, SYDNEY, DEPT IND TRADE & COMMERCE AUSTR, AUSTR NATL UNIV, DEPT NUCL PHYS, CANBERRA, DIGITAL EQUIPMENT CORP, AUSTR, EG&G ORTEC NUCLETRON, AUSTR, HIGH VOLTAGE ENGN EUROPA BV, MICRO ANAL RES CTR, MELBOURNE, NATL ELECTROSTAT CORP, USA AB Carbonaceous gases and aerosols emitted during fossil- and bio-mass combustion processes have significant impacts on regional health and visibility, and on global climate. C-14 accelerator mass spectrometry (AMS) has become the accepted standard for quantitatively partitioning individual combustion products between fossil and biospheric sources. Increased demands for source apportionment of toxic gases/vapors such as carbon monoxide and benzene, and toxic aerosol species such as polycyclic aromatic hydrocarbons, however, have led to increased needs for chemical source tracers. As a result, the application of atmospheric C-14 measurements has been extended to the discovery of new chemical tracers and the validation of the related apportionment models. These newer applications of C-14 are illustrated by recent investigations of: 1) sources of excessive concentrations of carbon monoxide and benzene in the urban atmosphere during the winter, as related to combustion source control strategies; and 2) the development/validation of potassium and hydrocarbon tracer models for the apportionment of mutagenic aerosols from biomass (wood) burning and motor vehicle emissions. Among the important consequences of these studies are new insights into potential limitations of elemental tracer models for biomass burning, and the impact of bivariate (isotopic, mass) chemical blanks on atmospheric C-14-AMS data. C1 ALLEGHENY COLL,DEPT CHEM,MEADVILLE,PA 16335. UNIV ARIZONA,NSF ACCELERATOR FACIL,TUCSON,AZ 85721. ENVIRONM HLTH DEPT,ALBUQUERQUE,NM 87103. RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 27 Z9 28 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1994 VL 92 IS 1-4 BP 404 EP 409 DI 10.1016/0168-583X(94)96043-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NV547 UT WOS:A1994NV54700082 ER PT J AU WEBB, RS ANDERSON, DM OVERPECK, JT AF WEBB, RS ANDERSON, DM OVERPECK, JT TI ARCHIVING DATA AT THE WORLD-DATA-CENTER-A FOR PALEOCLIMATOLOGY SO PALEOCEANOGRAPHY LA English DT Editorial Material RP WEBB, RS (reprint author), NOAA,NATL GEOPHYS DATA CTR,PALEOCLIMATOL PROGRAM,325 BROADWAY,BOULDER,CO 80303, USA. RI anderson, david/E-6416-2011 NR 0 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD JUN PY 1994 VL 9 IS 3 BP 391 EP 393 DI 10.1029/94PA00444 PG 3 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA NP230 UT WOS:A1994NP23000002 ER PT J AU SCHWARTZ, LM AUZERAIS, F DUNSMUIR, J MARTYS, N BENTZ, DP TORQUATO, S AF SCHWARTZ, LM AUZERAIS, F DUNSMUIR, J MARTYS, N BENTZ, DP TORQUATO, S TI TRANSPORT AND DIFFUSION IN 3-DIMENSIONAL COMPOSITE MEDIA SO PHYSICA A LA English DT Article; Proceedings Paper CT 3rd International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media (ETOPIM 3) CY AUG 09-13, 1993 CL GUANAJUATO, MEXICO ID POROUS-MEDIA; ELECTRICAL-CONDUCTIVITY; FLUID PERMEABILITY; GRAIN CONSOLIDATION; MAGNETIC-RESONANCE; CONTINUUM-SYSTEMS; RELAXATION; MODEL; PROBE AB We will review recent progress in our understanding of classical transport in porous media. Theoretical concepts will be illustrated with two distinct kinds of calculations. The first involve the grain consolidation model and are based on a particular multisize packing of spherical grains. The computational methods developed here are sufficiently accurate that we propose to combine them with direct measurements of the pore and grain geometry based on X-ray microtomography. Our preliminary results indicate that this approach may well play an important part in future studies of transport in porous media. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. NATL INST STAND & TECHNOL,DIV BLDG,GAITHERSBURG,MD 20899. PRINCETON UNIV,PRINCETON MAT INST,PRINCETON,NJ 08544. RP SCHWARTZ, LM (reprint author), SCHLUMBERGER DOLL RES CTR,OLD QUARRY RD,RIDGEFIELD,CT 06877, USA. NR 21 TC 41 Z9 41 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1994 VL 207 IS 1-3 BP 28 EP 36 DI 10.1016/0378-4371(94)90351-4 PG 9 WC Physics, Multidisciplinary SC Physics GA NR992 UT WOS:A1994NR99200005 ER PT J AU BELL, EW GUO, XQ FORAND, JL RINN, K SWENSON, DR THOMPSON, JS DUNN, GH BANNISTER, ME GREGORY, DC PHANEUF, RA SMITH, ACH MULLER, A TIMMER, CA WAHLIN, EK DEPAOLA, BD BELIC, DS AF BELL, EW GUO, XQ FORAND, JL RINN, K SWENSON, DR THOMPSON, JS DUNN, GH BANNISTER, ME GREGORY, DC PHANEUF, RA SMITH, ACH MULLER, A TIMMER, CA WAHLIN, EK DEPAOLA, BD BELIC, DS TI MERGED-BEAMS ENERGY-LOSS TECHNIQUE FOR ELECTRON-ION EXCITATION - ABSOLUTE TOTAL CROSS-SECTIONS FOR O5+(2S-]2P) SO PHYSICAL REVIEW A LA English DT Article ID IMPACT EXCITATION; 2S-2P EXCITATION; MONOCHROMATOR; SYSTEMS AB A merged-beams electron-energy-loss technique is described, by which absolute cross sections can be measured for near-threshold electron-impact excitation of multipy charged ions. Results are reported here for absolute total electron-impact excitation cross sections for the O5+(2s --> 2p) transition from below threshold to 1.6 eV above threshold. The experimental data are in good agremeent with a seven-state close-coupling calculation throughout the energy range of the experiment. Results agree with calculations showing that more than 90% of the electrons causing excitation are ejected in the backward direction in the center-of-mass frame. This backscattering is shown in both quantum-mechanical and semiclassical calculations. Evidence is observed for high-lying metastable autoionizing states with a lifetime of approximately 0.9 mus which are made to ionize by electron impact. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV LONDON UNIV COLL,LONDON WC1E 6BT,ENGLAND. UNIV STUTTGART,INST STRAHLENPHYS,D-70569 STUTTGART,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. KANSAS STATE UNIV AGR & APPL SCI,MANHATTAN,KS 66506. UNIV BELGRADE,BELGRADE,YUGOSLAVIA. RP BELL, EW (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Muller, Alfred/A-3548-2009; DePaola, Brett/I-3533-2013; OI Muller, Alfred/0000-0002-0030-6929; DePaola, Brett/0000-0003-3409-671X; Thompson, Jeffrey/0000-0001-9699-5767 NR 45 TC 49 Z9 49 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 JUN PY 1994 VL 49 IS 6 BP 4585 EP 4596 DI 10.1103/PhysRevA.49.4585 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NT908 UT WOS:A1994NT90800043 ER PT J AU BANNISTER, ME GUO, XQ KOJIMA, TM AF BANNISTER, ME GUO, XQ KOJIMA, TM TI ABSOLUTE CROSS-SECTIONS FOR ELECTRON-IMPACT SINGLE IONIZATION OF KR4+, KR5+, AND KR7+ IONS SO PHYSICAL REVIEW A LA English DT Article ID CHARGED KRYPTON IONS; RARE-GAS IONS AB Absolute total cross sections for electron-impact single ionization of Kr4+, Kr5+, and Kr7+ ions have been measured using a crossed-beams technique from below threshold to 500, 400, and 500 eV, respectively, with absolute uncertainties of 12% or less. The measured cross sections are in good agreement with distorted-wave calculations and show significant contributions from excitation autoionization. Nonzero cross sections below threshold for the Kr4+ and Kr5+ ions suggest the presence of metastable ions in those two species that were extracted from an electron-cyclotron-resonance ion source. Such evidence of metastable ions was not found in the case of the Kr7+ ion measurment. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP BANNISTER, ME (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. OI Bannister, Mark E./0000-0002-9572-8154 NR 20 TC 18 Z9 18 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1994 VL 49 IS 6 BP 4676 EP 4681 DI 10.1103/PhysRevA.49.4676 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NT908 UT WOS:A1994NT90800054 ER PT J AU DOUGLAS, JF ZHOU, HX HUBBARD, JB AF DOUGLAS, JF ZHOU, HX HUBBARD, JB TI HYDRODYNAMIC FRICTION AND THE CAPACITANCE OF ARBITRARILY-SHAPED OBJECTS SO PHYSICAL REVIEW E LA English DT Article ID MONTE-CARLO CALCULATION; MARKOV PROCESS EXPECTATIONS; CONTROLLED LIGAND-BINDING; KIRKWOOD-RISEMAN MODEL; EXCLUDED-VOLUME; WIENER SAUSAGE; THETA-POINT; TRANSLATIONAL DIFFUSION; RESIDUAL INTERACTIONS; ASYMPTOTIC EVALUATION AB The translational friction coefficient and the capacitance of a variety of objects are calculated with a probabilistic method involving hitting the ''probed'' objects with random walks launched from an enclosing spherical surface. This method is applied to exactly solvable examples to test the program accuracy and to physically important and analytically intractable examples (cube, chain of spheres at the vertices of self-avoiding and random walks, etc.). Large fluctuations in the friction of polymer chains with a random coil structure are found to give large deviations from the mean-field Kirkwood-Riseman theory and ''hydrodynamic fluctuation'' effects are found to diminish with the chain swelling accompanying excluded volume interaction. Capacity applications are reviewed and our probabilistic estimates of polymer friction are compared with previous calculations using alternative methods. Transients to the capacity and related properties are expressed in terms of fluctuations in the ''Wiener sausage'' volume (volume swept out by a Brownian particle where a repeated visit to a spatial region does not contribute to the volume increase in time). C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD. NIDDKD,CHEM PHYS LAB,BETHESDA,MD 20892. NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. RI Zhou, Huan-Xiang/M-5170-2016 OI Zhou, Huan-Xiang/0000-0001-9020-0302 NR 157 TC 66 Z9 66 U1 2 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1994 VL 49 IS 6 BP 5319 EP 5337 DI 10.1103/PhysRevE.49.5319 PN A PG 19 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA NW029 UT WOS:A1994NW02900076 ER PT J AU RABINOW, J AF RABINOW, J TI HUNTOON,ROBERT,DEWITT SO PHYSICS TODAY LA English DT Item About an Individual RP RABINOW, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 1994 VL 47 IS 6 BP 91 EP 92 DI 10.1063/1.2808544 PG 2 WC Physics, Multidisciplinary SC Physics GA NQ893 UT WOS:A1994NQ89300016 ER PT J AU MERRICK, RL LOUGHLIN, TR ANTONELIS, GA HILL, R AF MERRICK, RL LOUGHLIN, TR ANTONELIS, GA HILL, R TI USE OF SATELLITE-LINKED TELEMETRY TO STUDY STELLER SEA LION AND NORTHERN FUR-SEAL FORAGING SO POLAR RESEARCH LA English DT Article; Proceedings Paper CT 2nd Circumpolar Symposium on Remote Sensing of Arctic Environments CY MAY 04-06, 1992 CL UNIV TROMSO, TROMSO, NORWAY SP UNIV TROMSO, TROMSO SATELLITE STN, AKVAPLAN NIVA A S, FDN APPL RES HO UNIV TROMSO ID EUMETOPIAS-JUBATUS; ALASKA AB One explanation for recent declines in some Alaskan pinniped populations is that ecosystem changes may have reduced the availability of preferred prey. Part of our evaluation of this hypothesis involves the use of satellite-linked telemetry to study Steller sea lion (Eumetopias jubatus) and northern fur seal (Callorhinus ursinus) foraging. Data on dives (depth and duration) and water temperatures arc collected by satellite-linked time-depth recorders (SLTDR) glued to the backs of sea lions and fur seals. These data are then summarized and stored for later transmission. Data are relayed back to land through NOAA Tiros-series satellites and are processed by Service-Argos (a U.S.-French consortium). These transmissions are also used to calculate at-sea and on-land locations of the animals through use of Doppler shifts of the frequency of received transmissions. Ultimately, diving and temperature can be reconciled with at-sea locations to compare foraging areas with locations of known prey stocks. C1 WILDLIFE COMP,WOODINVILLE,WA 98072. RP MERRICK, RL (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115, USA. NR 17 TC 31 Z9 31 U1 2 U2 11 PU NORWEGIAN POLAR INST PI OSLO PA POSTBOKS 5072 MAJORSTUA, 1330 OSLO, NORWAY SN 0800-0395 J9 POLAR RES JI Polar Res. PD JUN PY 1994 VL 13 IS 1 BP 105 EP 114 DI 10.1111/j.1751-8369.1994.tb00441.x PG 10 WC Ecology; Geosciences, Multidisciplinary; Oceanography SC Environmental Sciences & Ecology; Geology; Oceanography GA PA905 UT WOS:A1994PA90500011 ER PT J AU KEY, JR AF KEY, JR TI THE AREA COVERAGE OF GEOPHYSICAL FIELDS AS A FUNCTION OF SENSOR FIELD-OF-VIEW SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID AUTO-CORRELATION; DIGITAL IMAGES; CLOUD-COVER; REGULARIZATION; MODEL AB In many remote sensing studies of geophysical fields such as clouds, land cover, or sea ice characteristics, the fractional area coverage of the field in an image is estimated as the proportion of pixels that have the characteristic of interest (i.e., are part of the field) as determined by some thresholding operation. The effect of sensor field-of-view on this estimate is examined by modeling the unknown distribution of subpixel area fraction with the beta distribution, whose two parameters depend upon the true fractional area coverage, the pixel size, and the spatial structure of the geophysical field. Since it is often not possible to relate digital number, reflectance, or temperature to subpixel area fraction, the statistical models described are used to determine the effect of pixel size and thresholding operations on the estimate of area fraction for hypothetical geophysical fields. Examples are given for simulated cumuliform clouds and linear openings in sea ice, whose spatial structures are described by an exponential autocovariance function. It is shown that the rate and direction of change in total area fraction with changing pixel size depends on the true area fraction, the spatial structure, and the thresholding operation used. RP KEY, JR (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, DIV CRYOSPHER & POLAR PROC, CAMPUS BOX 449, BOULDER, CO 80309 USA. RI Key, Jeffrey/F-5597-2010 OI Key, Jeffrey/0000-0001-6109-3050 NR 17 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JUN PY 1994 VL 48 IS 3 BP 339 EP 346 DI 10.1016/0034-4257(94)90008-6 PG 8 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA NV604 UT WOS:A1994NV60400008 ER PT J AU KEY, J MASLANIK, JA ELLEFSEN, E AF KEY, J MASLANIK, JA ELLEFSEN, E TI THE EFFECTS OF SENSOR FIELD-OF-VIEW ON THE GEOMETRICAL CHARACTERISTICS OF SEA-ICE LEADS AND IMPLICATIONS FOR LARGE-AREA HEAT-FLUX ESTIMATES SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID ARCTIC LEADS; EXCHANGE; SCALE AB The release of heat from sea ice fractures (''leads'') is an important component of the heat budget in the Arctic, but their impact on regional scale climate is difficult to assess without more information on their distribution in both space and time. Remote sensing of leads using satellite data, specifically AVHRR thermal and Landsat visible-band imagery, is examined empirically with respect to lead width, orientation, and area fraction. The geometrical aspects of the sensor are simulated so that of sensor field-of-view on retrieved lead width statistics can be assessed. This is done using Landsat data and simulated lead networks degraded to AVHRR pixel sizes. The analyses illustrate how leads of sufficiently high contrast tend to ''grow'' with increasing pixel size and how small or low contrast leads disappear. The relationship between lead contrast and the width/field-of-view ratio is also examined in order to determine the limits of lead detectability, and illustrates the multivalued nature of the problem of lead width retrieval. To help quantify the importance of changes in lead statistics, turbulent heat flux is calculated as a function of lead width and lead fraction. It is shown that pixel size has a substantial effect on estimates of turbulent heat transfer from leads to the atmosphere. RP KEY, J (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DIV CRYOSPHER & POLAR PROC,CAMPUS BOX 449,BOULDER,CO 80309, USA. RI Key, Jeffrey/F-5597-2010 OI Key, Jeffrey/0000-0001-6109-3050 NR 19 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JUN PY 1994 VL 48 IS 3 BP 347 EP 357 DI 10.1016/0034-4257(94)90009-4 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA NV604 UT WOS:A1994NV60400009 ER PT J AU HANSEN, BN LAGALANTE, AF SIEVERS, RE BRUNO, TJ AF HANSEN, BN LAGALANTE, AF SIEVERS, RE BRUNO, TJ TI HIGH-PRESSURE EQUILIBRIUM CELL FOR SOLUBILITY MEASUREMENTS IN SUPERCRITICAL FLUIDS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID STATE AB This paper describes the design, construction, and operation of an ultraviolet-visible light-transmission cell for high-pressure fluids. The cell can be operated at pressures as high as 70 MPa and at temperatures up to 100-degrees-C. This instrument was specifically designed to measure the solubility of solutes in supercritical fluids. The cell has an internal saturator and fluid circulator that are easy to remove and clean. The solubility of ferrocene in supercritical carbon dioxide was measured in the high-pressure cell described here. At 40-degrees-C, the mole fraction of ferrocene in carbon dioxide increased from 0.00005 to 0.0015 as the solvent density was increased from 5 to 17 mol/L. RP HANSEN, BN (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 9 TC 17 Z9 17 U1 0 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 JUN PY 1994 VL 65 IS 6 BP 2112 EP 2114 DI 10.1063/1.1144821 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NU854 UT WOS:A1994NU85400048 ER PT J AU RICHARDS, TW AF RICHARDS, TW TI MODERNIZING NOAAS MARINE NAVIGATION SERVICES SO SEA TECHNOLOGY LA English DT Editorial Material RP RICHARDS, TW (reprint author), NOAA,DIV NAVT CHARTING,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD JUN PY 1994 VL 35 IS 6 BP 105 EP 105 PG 1 WC Engineering, Ocean SC Engineering GA NR524 UT WOS:A1994NR52400014 ER PT J AU PAP, JM WILLSON, RC FROHLICH, C DONNELLY, RF PUGA, L AF PAP, JM WILLSON, RC FROHLICH, C DONNELLY, RF PUGA, L TI LONG-TERM VARIATIONS IN TOTAL SOLAR IRRADIANCE SO SOLAR PHYSICS LA English DT Article; Proceedings Paper CT IAU Colloquium NO 143 on the Sun as a Variable Star: Solar and Stellar Irradiance Variations CY JUN 20-25, 1993 CL BOULDER, CO SP INT ASTRON UNION ID MODULATION; SUNSPOTS; CYCLE AB For more than a decade total solar irradiance has been monitored simultaneously from space by different satellites. The detection of total solar irradiance variations by satellite-based experiments during the past decade and a half has stimulated modeling efforts to help identify their causes and to provide estimates of irradiance data, using 'proxy' indicators of solar activity, for time intervals when no satellite observations exist. In this paper total solar irradiance observed by the Nimbus-7/ERB, SMM/ACRIM I, and UARS/ACRIM II radiometers is modeled with the Photometric Sunspot Index and the Mg II core-to-wing ratio. Since the formation of the Mg II line is very similar to that of the Ca II K line, the Mg core-to-wing ratio, derived from the irradiance observations of the Nimbus-7 and NOAA9 satellites, is used as a proxy for the bright magnetic elements. It is shown that the observed changes in total solar irradiance are underestimated by the proxy models at the time of maximum and during the beginning of the declining portion of solar cycle 22 similar to behavior just before the maximum of solar cycle 21. This disagreement between total irradiance observations and their model estimates is indicative of the fact that the underlying physical mechanism of the changes observed in the solar radiative output is not well-understood. Furthermore, the uncertainties in the proxy data used for irradiance modeling and the resulting limitation of the models should be taken into account, especially when the irradiance models are used for climatic studies. C1 WORLD RADIAT CTR,PHYS METEOROL OBSERV DAVOS,DAVOS,SWITZERLAND. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP PAP, JM (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 31 TC 22 Z9 22 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 JUN PY 1994 VL 152 IS 1 BP 13 EP 21 DI 10.1007/BF01473177 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NY582 UT WOS:A1994NY58200004 ER PT J AU DONNELLY, RF WHITE, OR LIVINGSTON, WC AF DONNELLY, RF WHITE, OR LIVINGSTON, WC TI THE SOLAR CA-II-K INDEX AND THE MG-II CORE-TO-WING RATIO SO SOLAR PHYSICS LA English DT Article; Proceedings Paper CT IAU Colloquium NO 143 on the Sun as a Variable Star: Solar and Stellar Irradiance Variations CY JUN 20-25, 1993 CL BOULDER, CO SP INT ASTRON UNION AB The 1angstrom index of the solar Ca II K line is compared with the core-to-wing ratio of satellite measurements of the Mg II h and k lines. The correlation coefficient r = 0.976 for the Nimbus-7 Mg II ratio during solar cycle 21 and r = 0.99 for the NOAA9 Mg II ratio in cycle 22. Linear regression analysis for the full dynamic range of both data sets is used to combine the Nimbus-7 and NOAA9 Mg II data. These relations permit the ground-based Ca K index to estimate the solar UV flux. C1 NCAR,HIGH ALTIDUDE OBSERV,BOULDER,CO 80307. NATL OPT ASTRON OBSERV,NATL SOLAR,TUCSON,AZ 85726. RP DONNELLY, RF (reprint author), NOAA,ERL,SPACE ENVIRONM LAB,BOULDER,CO 80303, USA. NR 8 TC 24 Z9 24 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 JUN PY 1994 VL 152 IS 1 BP 69 EP 76 DI 10.1007/BF01473185 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NY582 UT WOS:A1994NY58200012 ER PT J AU HARTSELL, TP BORNMANN, PL AF HARTSELL, TP BORNMANN, PL TI ACTIVE-REGION EVOLUTION AND SOLAR FLUX VARIATIONS SO SOLAR PHYSICS LA English DT Article; Proceedings Paper CT IAU Colloquium NO 143 on the Sun as a Variable Star: Solar and Stellar Irradiance Variations CY JUN 20-25, 1993 CL BOULDER, CO SP INT ASTRON UNION ID MAGNETIC-FIELDS; VARIABILITY; MODEL; EUV AB The goal of this study is to relate the changes in the solar radiative output to the growth and decay of magnetic active regions. We will test the assumption that each index of radiation variability is a convolution of an active-region magnetic driving function and a response function. The first step has been to identify the appropriate driving function. This driving function was assumed to have been data from the magnetic active regions derived from the Mount Wilson daily magnetograms (Howard, 1989). The daily magnetic reports were sorted to give active-region sequences. To estimate the magnetic flux of active regions outside the observing window. (i.e., behind the limb) we fit the data to a growing-and-decaying exponential function, which permits independent growth and decay. This double exponential gives reasonable fits to the observed temporal evolution of active-region magnetic flux. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP HARTSELL, TP (reprint author), UNIV COLORADO,APAS DEPT,LASP,BOULDER,CO 80309, USA. NR 8 TC 0 Z9 1 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 JUN PY 1994 VL 152 IS 1 BP 189 EP 194 DI 10.1007/BF01473203 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NY582 UT WOS:A1994NY58200030 ER PT J AU REISH, DJ OSHIDA, PS MEARNS, AJ GINN, TC AF REISH, DJ OSHIDA, PS MEARNS, AJ GINN, TC TI EFFECTS OF POLLUTION ON SALTWATER ORGANISMS SO WATER ENVIRONMENT RESEARCH LA English DT Review ID MACROBENTHIC COMMUNITY STRUCTURE; PORPOISE PHOCOENA-PHOCOENA; TRACE-METALS; OIL-SPILL; MYTILUS-EDULIS; CRUDE-OIL; CRASSOSTREA-VIRGINICA; BIVALVE MOLLUSKS; MERETRIX-LUSORIA; BRITISH-COLUMBIA C1 US EPA,SAN FRANCISCO,CA. NOAA,SEATTLE,WA 98115. PTI ENVIRONM SCI INC,BELLEVUE,WA. RP REISH, DJ (reprint author), CALIF STATE UNIV LONG BEACH,DEPT BIOL,LONG BEACH,CA 90840, USA. NR 151 TC 0 Z9 0 U1 1 U2 3 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 SN 1061-4303 J9 WATER ENVIRON RES JI Water Environ. Res. PD JUN PY 1994 VL 66 IS 4 BP 623 EP 635 PG 13 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA NW438 UT WOS:A1994NW43800037 ER PT J AU HSU, SM SHEN, MC KLAUS, EE CHENG, HS LACEY, PI AF HSU, SM SHEN, MC KLAUS, EE CHENG, HS LACEY, PI TI MECHANOCHEMICAL MODEL - REACTION TEMPERATURES IN A CONCENTRATED CONTACT SO WEAR LA English DT Article ID WEAR; SURFACES AB Successful boundary lubrication is essential in the design and operation of many mechanical components. The lubrication process is complex and it involves contact mechanics, fluid mechanics, tribochemistry, and material deformation and fracture. Two schools of thought have emerged over the years in examining the mechanisms and modeling of boundary lubrication. The chemical school believes that chemical reactions at the rubbing surfaces control the efficacy of the lubrication process. The mechanical school believes that while chemistry is a factor, hydrodynamics, elastohydrodynamics (EHD), and micro-EHD can account for most of the load-bearing mechanisms, so at least in design, they are the principal issues. This paper attempts to bring the two schools together to examine a common set of experimental data. The experiments involve running wear tests on a four-ball wear tester using microliters of lubricant until seizure. Lubricant degradation and breakdown are therefore a factor in the wear test. Eventually we would like to compare the chemical kinetic model with the mechanical contact model in describing and predicting the effectiveness of the lubrication process, i.e. the time to seizure. The chemical kinetics model assumes that oxygen consumption by the lubricant to make friction polymers controls the process. The mechanical model suggests that if temperatures in the contact exceed a certain limit, scuffing will occur. The key to both models is the temperatures in the contact. This paper describes the two models and focuses on the temperatures in the contact. The temperatures calculated from the two models differ significantly. The temperatures predicted by chemical kinetics are about 100-degrees-C higher than the mechanical model. The identification of the discrepancy and the magnitude of the difference highlight the difference between the two approaches. It is hoped that this paper will bring forth further research effort to this critical issue. Various possible explanations were offered for the temperature difference. A plausible explanation was proposed and initial calculations suggest that by taking into account of the wear process, the temperatures calculated by the mechanical model can reach the temperatures estimated by the chemical model. C1 NORTHWESTERN UNIV,CTR ENGN TRIBOL,EVANSTON,IL 60208. PENN STATE UNIV,DEPT CHEM ENGN,UNIV PK,PA 16802. RP HSU, SM (reprint author), NATL INST STAND & TECHNOL,SURFACE PROPERTIES GRP,GAITHERSBURG,MD 20899, USA. NR 25 TC 21 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUN PY 1994 VL 175 IS 1-2 BP 209 EP 218 DI 10.1016/0043-1648(94)90184-8 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA NT595 UT WOS:A1994NT59500024 ER PT J AU DEMARIA, M KAPLAN, J AF DEMARIA, M KAPLAN, J TI A STATISTICAL HURRICANE INTENSITY PREDICTION SCHEME (SHIPS) FOR THE ATLANTIC BASIN SO WEATHER AND FORECASTING LA English DT Article AB A statistical model for predicting intensity changes of Atlantic tropical cyclones at 12, 24, 36, 48, and 72 h is described. The model was developed using a standard multiple regression technique with climatological, persistence, and synoptic predictors. The model developmental sample includes all of the named Atlantic tropical cyclones from 1989 to 1992, with a few additional cases from 1982 to 1988. The sample includes only the times when the storms were over the ocean. The four primary predictors are 1) the difference between the current storm intensity and an estimate of the maximum possible intensity determined from the sea surface temperature, 2) the vertical shear of the horizontal wind, 3) persistence, and 4) the flux convergence of eddy angular momentum evaluated at 200 mb. The sea surface temperature and vertical shear variables are averaged along the track of the storm during the forecast period. The sea surface temperatures along the storm track are determined from monthly climatological analyses linearly interpolated to the position and date of the storm. The vertical shear values along the track of the storm are estimated using the synoptic analysis at the beginning of the forecast period. All other predictors are evaluated at the beginning of the forecast period. The model is tested using a jackknife procedure where the regression coefficients for a particular tropical cyclone are determined with all of the forecasts for that storm removed from the sample. Operational estimates of the storm track and initial storm intensity are used in place of best track information in the jackknife procedure. Results show that the average intensity errors are 10%-15% smaller than the errors from a model that uses only climatology and persistence (SHIFOR), and the error differences at 24, 36, and 48 h are statistically significant at the 99% level. RP DEMARIA, M (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,DIV HURRICANE RES,4301 RICKENBACKET CAUSEWAY,MIAMI,FL 33149, USA. RI DeMaria, Mark/F-5583-2010; Kaplan, John/A-8709-2014 OI Kaplan, John/0000-0002-7253-3039 NR 0 TC 173 Z9 183 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1994 VL 9 IS 2 BP 209 EP 220 DI 10.1175/1520-0434(1994)009<0209:ASHIPS>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA QL524 UT WOS:A1994QL52400004 ER PT J AU GILHOUSEN, DB AF GILHOUSEN, DB TI THE VALUE OF NDBC OBSERVATIONS DURING MARCH 1993S STORM OF THE CENTURY SO WEATHER AND FORECASTING LA English DT Note AB National Data Buoy Center (NDBC) observations from the western Gulf of Mexico provided several early indications of more rapid cyclogenesis on 12 March 1993 than was forecast by numerical weather prediction (NWP) models. Observations demonstrated a closed circulation with gale-force winds shortly after the storm entered the Gulf of Mexico. Pressure measurements at two buoys off the Texas coast were 4-6 hPa lower than the 12-h NWP forecasts, a significant forecast error. Observations from NDBC's moored buoys and Coastal-Marine Automated Network stations revealed that the developing storm was significantly deeper than was indicated on the National Meteorological Center's automated surface analyses. Ocean wave observations reveal some of the steepest waves NDBC has ever measured, indicating phenomenal wave growth and a high potential for damage to vessels and structures. A warm eddy caused sea surface temperatures (SST) to be several degrees above normal under the track of the storm, creating a strong SST gradient to the north. This provided ample energy and strengthened the baroclinicity. NDBC observations showed the eddy to be somewhat larger and warmer than indicated by the most recent National Hurricane Center analysis. This event demonstrates the tremendous value of NDBC marine observations for accurately detecting the occurrence and strength of coastal cyclogenesis events. RP GILHOUSEN, DB (reprint author), NOAA,NATL DATA BUOY CTR,BAY ST LOUIS,MS 39529, USA. NR 0 TC 10 Z9 10 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 JUN PY 1994 VL 9 IS 2 BP 255 EP 264 DI 10.1175/1520-0434(1994)009<0255:TVONOD>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA QL524 UT WOS:A1994QL52400008 ER PT J AU BLACK, TL AF BLACK, TL TI THE NEW NMC MESOSCALE ETA-MODEL - DESCRIPTION AND FORECAST EXAMPLES SO WEATHER AND FORECASTING LA English DT Note AB In mid-1994 a new version of the Eta Model will begin producing operational forecast guidance down to mesoscale ranges. This version will have a horizontal resolution of approximately 30 km and about 50 layers in the vertical. A summary of the primary aspects of the model is presented that includes a description of the eta coordinate and of the dynamical and physical components. Advantages of the mesoscale model are indicated in precipitation skill scores for November 1993. Specific examples are discussed that describe the mesoscale model's ability to capture small-scale circulations under fundamentally different circumstances: (i) the propagation of a strong cold front where the forcing was primarily internal and not orographic; and (ii) a rainfall event where the forcing arose from the interaction of topography with the synoptic-scale flow. RP BLACK, TL (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,DIV DEV,W-NMC 22,ROOM 204,WASHINGTON,DC 20233, USA. NR 0 TC 427 Z9 434 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD JUN PY 1994 VL 9 IS 2 BP 265 EP 278 DI 10.1175/1520-0434(1994)009<0265:TNNMEM>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA QL524 UT WOS:A1994QL52400009 ER PT J AU LOWNEY, JR THURBER, WR SEILER, DG AF LOWNEY, JR THURBER, WR SEILER, DG TI TRANSVERSE MAGNETORESISTANCE - A NOVEL 2-TERMINAL METHOD FOR MEASURING THE CARRIER DENSITY AND MOBILITY OF A SEMICONDUCTOR LAYER SO APPLIED PHYSICS LETTERS LA English DT Article AB The magnetic-field dependence of the two-terminal magnetoresistance that occurs in rectangularly shaped samples can be used to determine both the free-carrier density and the mobility of a semiconductor layer. An approximate equation for the magnetoresistance was derived for variable length-to-width ratio. This technique was used to determine the electron density and mobility of accumulation layers in n-type Hg0.8Cd0.2Te photoconductive infrared detectors at 6 and 77 K. It should be applicable to a wide variety of fabricated devices and allow significant improvements in processing methods and quality control. RP LOWNEY, JR (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 11 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 30 PY 1994 VL 64 IS 22 BP 3015 EP 3017 DI 10.1063/1.111389 PG 3 WC Physics, Applied SC Physics GA NN752 UT WOS:A1994NN75200035 ER PT J AU CHIBA, M IYENGAR, V GREENBERG, RR GILLS, T AF CHIBA, M IYENGAR, V GREENBERG, RR GILLS, T TI DETERMINATION OF TIN IN BIOLOGICAL-MATERIALS BY ATOMIC-ABSORPTION SPECTROPHOTOMETRY AND NEUTRON-ACTIVATION ANALYSIS SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE TIN; BIOLOGICAL REFERENCE MATERIALS; ATOMIC ABSORPTION SPECTROPHOTOMETRY (AAS); INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS (INAA); RADIOCHEMICAL NEUTRON ACTIVATION ANALYSIS (RNAA) ID TRACE-ELEMENTS; HUMAN-MILK; SPECTROMETRY; SAMPLES AB Concentrations of Tin (Sn) were determined in botanical, dietary and biological reference materials (RMs), and in human livers from Japanese and American subjects using atomic absorption spectrophotometry (AAS) and neutron activation analysis (NAA), either in the instrumental mode (INAA) or in the radiochemical mode (RNAA). The mean Sn concentrations (+/- 1 S.D.) found in various RMs are: total diet (NIST SRM-1548) 3.57 +/- 0.52 and 3.61 +/- 0.52 mug/g by AAS and INAA, respectively; non-fat milk powder (NIST SRM-1549) 2.5 +/- 1.4 ng/g and 1.9 +/- 0.3 ng/g, bovine liver (NBS SRM-1577) 18 +/- 2 and 20 +/- 0.3 ng/g; and citrus leaves (NIST SRM-1542) 0.25 +/- 0.02 and 0.243 +/- 0.006 mug/g by AAS and RNAA, respectively. These comparisons demonstrate good agreement between the two methods. In apple leaves (NIST SRM-1515) and peach leaves (NIST SRM-1547), the measured concentrations by AAS were 77.1 +/- 20 and 85 +/- 15 ng/g; interferences by Tb-160 did not permit an accurate assessment by INAA at this concentration. The Sn results obtained for the American human liver specimens by RNAA ranged from 0.135-0.712 mug/g wet weight, and the Sn concentrations in Japanese human liver specimens determined by AAS ranged from 0.078-1.122 mug/g wet weight in 23 individuals. The results from this study show that it is feasible to use INAA/RNAA and AAS in combination to establish recommended values in RMs. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CHIBA, M (reprint author), JUNTENDO UNIV,SCH MED,BUNKYO KU,TOKYO 113,JAPAN. NR 15 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAY 30 PY 1994 VL 148 IS 1 BP 39 EP 44 DI 10.1016/0048-9697(94)90371-9 PG 6 WC Environmental Sciences SC Environmental Sciences & Ecology GA NN424 UT WOS:A1994NN42400005 PM 8016637 ER PT J AU NENOFF, TM HARRISON, WTA GIER, TE KEDER, NL ZAREMBA, CM SRDANOV, VI NICOL, JM STUCKY, GD AF NENOFF, TM HARRISON, WTA GIER, TE KEDER, NL ZAREMBA, CM SRDANOV, VI NICOL, JM STUCKY, GD TI STRUCTURAL AND CHEMICAL INVESTIGATIONS OF NA3(ABO4)3-CENTER-DOT-4H2O-TYPE SODALITE PHASES SO INORGANIC CHEMISTRY LA English DT Article ID ROOM-TEMPERATURE; DIFFRACTION AB The sodalite cage containing only an electron as a nonframework ''anion' is well adapted for the study of solvated ''electride'' Wigner lattices and quantitative mapping of the intra- and intercage electronic potential surfaces. In this paper we report the direct synthesis of anion free cage structures of the form Na3[](ABO4)3.nH2O (A; B = Al, Ga; Si, Ge) as possible precursors for sodalite electride synthesis. A novel, low-temperature sodalite dehydroxylation method is presented for the preparation of Na3[](AlSiO4)3.4H2O from Na4[OH](AlSiO4)3.1.72H2O. Results from a neutron diffraction study of Na3(ZnAsO4)3.4H2O give evidence of hydrogen bonding between the framework oxygen atoms and the beta-cage substructure and aid in explanation of analog unit cell trends. All of the investigated sodalites have an ordered array of their framework tetrahedral cations and crystallize in the cubic space group P43nBAR, Z = 2. Two of these new sodalites were characterized by single-crystal X-ray diffraction. Na3(AlGeO4)3.4H2O, with a = 8.965(1) angstrom, d(Al-O) = 1.746(4) angstrom, d(Ge-O) = 1.758(4) angstrom, and THETA(Al-O-Ge) = 129.6(2)degrees, has beta-cages which contain a defect-''cubane''-like Na3.4H2O array. Final disagreement factors: R = 1.93% and R(w) = 2.19% for 208 observed reflections [I > 3sigma(I)]. Na3(GaGeO4)3-4H2O, with a = 9.0033(7) angstrom, d(Ga-O) = 1.839(3) angstrom, d(Ge-O) = 1.745(3) angstrom, and THETA(Ga-O-Ge) = 125.3(2)degrees, has the same beta-cage contents. Final disagreement factors of R = 1.00% and R(w) = 1.29% were obtained for 183 observed reflections [I > 3sigma(I)]. The structure of Na3-[(GaSiO4)3].4H2O was determined by Rietveld refinement of room-temperature X-ray powder diffraction data, with a = 8.8614(2) angstrom, d(Ga-O) = 1.847(4) angstrom, d(Si-O) = 1.580(3) angstrom, THETA(Ga-O-Si) = 131.9(3)degrees, and the same beta-cage contents. Final disagreement factors of R(p) = 10.07% and R(wp) = 13.75% for 4099 data were obtained. The structure of Na3(ZnASO4)3.4H2O was determined from low-temperature continuous-wavelength neutron powder diffraction data, with a = 9.0276(7) angstrom, d(Zn-O) = 1.974(4) angstrom, d(As-O) = 1.689(4) angstrom, THETA(Zn-O-As) = 121.1(3)degrees, and the same beta-cage contents, with evidence of hydrogen bonding between cubane and framework atoms. Final disagreement factors of R(p) = 4.26% and R(wp) = 5.52% for 3268 data were obtained. These isomorphs are compared with other Na3[](ABO4)3.4H2O types of sodalite structures in terms of geometrical trends in 6-ring topologies and cation and water molecule sitings. Further structural information is obtained through presented spectral, thermogravimetric, and physical data. C1 UNIV CALIF SANTA BARBARA, DEPT CHEM, SANTA BARBARA, CA 93106 USA. UNIV HOUSTON, DEPT CHEM, HOUSTON, TX 77204 USA. NATL INST STAND & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. NR 31 TC 42 Z9 42 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD MAY 25 PY 1994 VL 33 IS 11 BP 2472 EP 2480 DI 10.1021/ic00089a026 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA NN518 UT WOS:A1994NN51800026 ER PT J AU BANNISTER, ME GUO, XQ KOJIMA, TM DUNN, GH AF BANNISTER, ME GUO, XQ KOJIMA, TM DUNN, GH TI RESONANCE STRUCTURE AND ABSOLUTE CROSS-SECTIONS IN NEAR-THRESHOLD ELECTRON-IMPACT EXCITATION OF THE 4S(21)S-]4S4P(3)P INTERCOMBINATION TRANSITION IN KR6+ SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY-LOSS; BEAMS AB First measurements of absolute total cross sections for electron-impact excitation of an intercombination transition to a nonradiating state of an ion are reported. The cross sections for near-threshold excitation of the 4s2 1S --> 4s4p 3p transition of Kr6+ are dominated by dielectronic resonances. The measurements can serve as a benchmark for theoretical predictions of dielectronic resonance structure in the excitation of multicharged ions. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP BANNISTER, ME (reprint author), OAK RIDGE NATL LAB,DEPT PHYS,OAK RIDGE,TN 37831, USA. NR 18 TC 22 Z9 22 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 MAY 23 PY 1994 VL 72 IS 21 BP 3336 EP 3338 DI 10.1103/PhysRevLett.72.3336 PG 3 WC Physics, Multidisciplinary SC Physics GA NM835 UT WOS:A1994NM83500012 ER PT J AU LYNN, JW ROSOV, N GRIGEREIT, TE ZHANG, H CLINTON, TW AF LYNN, JW ROSOV, N GRIGEREIT, TE ZHANG, H CLINTON, TW TI VORTEX DYNAMICS AND MELTING IN NIOBIUM SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; FLUX-LINE LATTICES; NEUTRON-DIFFRACTION; MONTE-CARLO; NB; IRREVERSIBILITY; YBA2CU3O7; STATE AB Small angle neutron scattering has been used to investigate the vortex scattering in single crystal niobium. In the mixed state (H(c1) < H < H(c2)) a sixfold hexagonal pattern of peaks is observed at all temperatures. Below the irreversibility line these peaks are resolution limited, while above it the width in the transverse direction increases with temperature due to the vortex dynamics. Close to H(c2) the radial widths of the peaks also broaden. However, the basic hexagonal pattern of peaks is maintained throughout, indicating that a correlated flux fluid exists in the reversible regime. C1 UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCTIV RES,COLLEGE PK,MD 20742. RP LYNN, JW (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 24 TC 26 Z9 26 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 23 PY 1994 VL 72 IS 21 BP 3413 EP 3416 DI 10.1103/PhysRevLett.72.3413 PG 4 WC Physics, Multidisciplinary SC Physics GA NM835 UT WOS:A1994NM83500032 ER PT J AU Murphy, DM Fahey, DW AF Murphy, D. M. Fahey, D. W. TI An estimate of the flux of stratospheric reactive nitrogen and ozone into the troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB The globally averaged net downward annual fluxes of reactive nitrogen (NOy) and O-3 from the stratosphere are estimated using observed correlations of N2O with NOy and O-3. The linearity of the observed correlations in the lower stratosphere allows the downward fluxes of NOy and O-3 to be related to the upward flux of N2O. The upward flux of N2O can be calculated from a mass balance and stratospheric photochemistry. In this way, the complicated photochemistry and transport of NOy and O-3 can be bounded by a much simpler calculation involving N2O. The estimated NOy net flux of 0.45 Tg (N) yr(-1) ( range 0.23-0.73) is slightly less than previous estimates, but within the range of uncertainty. Precipitation of NOy from the Antarctic winter stratosphere may be a significant fraction of the annual global flux out of the lower stratosphere. The global budget for stratospheric NOy shows that an N2O lifetime greater than 160 years is inconsistent with extensive mass flow through the Antarctic winter vortex. The estimated O-3 flux of 3.5x10(10) molecules cm(-2) s(-1) (range 1.5-6.8) agrees well with previous estimates using completely independent techniques. C1 [Murphy, D. M.; Fahey, D. W.] NOAA, ERL, Aeron Lab, Boulder, CO 80303 USA. RP Murphy, DM (reprint author), NOAA R E AL6, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Murphy, Daniel/J-4357-2012; Fahey, David/G-4499-2013 OI Murphy, Daniel/0000-0002-8091-7235; Fahey, David/0000-0003-1720-0634 NR 37 TC 117 Z9 118 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1994 VL 99 IS D3 BP 5325 EP 5332 DI 10.1029/93JD03558 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V04QH UT WOS:000207072400005 ER PT J AU Reinsel, GC Tiao, GC Wuebbles, DJ Kerr, JB Miller, AJ Nagatani, RM Bishop, L Ying, LH AF Reinsel, Gregory C. Tiao, George C. Wuebbles, Donald J. Kerr, James B. Miller, Alvin J. Nagatani, Ronald M. Bishop, Lane Ying, Lisa H. TI Seasonal trend analysis of published ground-based and TOMS total ozone data through 1991 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB A seasonal trend analysis of published Dobson (including stations' newly revised and Brewer-simulated Dobson) total ozone data through 1991 from a network of 56 stations has been performed, using three different data periods. The trend results for the longest data period 1964-1991 indicate substantial negative trends in ozone in the higher northern latitudes during the winter and spring seasons, some evidence of negative trend in the higher southern latitudes (30 degrees S-55 degrees S) during all seasons, and trends close to zero for all seasons over the 30 degrees S-30 degrees N latitude range. For the shortest data period, November 1978 through 1991, there is a clear indication that trends have become more negative in the higher northern latitudes, especially during the winter and spring seasons, and also in the higher southern latitudes in all seasons. A seasonal trend analysis of zonal averages of total ozone mapping spectrometer (TOMS) satellite total ozone data for the comparable period November 1978 through 1991 has also been performed, and moderately good agreement is found between trends in Dobson and TOMS data over this period. C1 [Reinsel, Gregory C.; Ying, Lisa H.] Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. [Bishop, Lane] Allied Signal Inc, Ctr Appl Math, Buffalo, NY 14210 USA. [Kerr, James B.] Atmospher Environm Serv, Toronto, ON M3H 5T4, Canada. [Miller, Alvin J.; Nagatani, Ronald M.] Natl Ocean & Atmospher Adm, NWS Climate Anal Ctr, Washington, DC 20233 USA. [Tiao, George C.] Univ Chicago, Grad Sch Business, Chicago, IL 60637 USA. [Wuebbles, Donald J.] Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Reinsel, GC (reprint author), Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. EM reinsel@stat.wisc.edu; gct@gsbgct.uchicago.edu; wuebbles@llnl.gov; jkerr@dow.on.doe.ca; miller@upair.wwb.noaa.gov; bishop@research.allied.com FU Alternative Fluorocarbons Environmental Acceptability Study (AFEAS); National Aeronautics and Space Administration (NASA); National Oceanic and Atmospheric Administration (NOAA) FX This research was supported in part by the Alternative Fluorocarbons Environmental Acceptability Study (AFEAS), the National Aeronautics and Space Administration ( NASA), and the National Oceanic and Atmospheric Administration (NOAA). The authors also would like to thank the reviewers for several helpful comments that improved the paper. NR 20 TC 64 Z9 68 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 MAY 20 PY 1994 VL 99 IS D3 BP 5449 EP 5464 DI 10.1029/93JD03517 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V04QH UT WOS:000207072400013 ER PT J AU STRAHAN, SE MAHLMAN, JD AF STRAHAN, SE MAHLMAN, JD TI EVALUATION OF THE SKYHI GENERAL-CIRCULATION MODEL USING AIRCRAFT N2O MEASUREMENTS .1. POLAR WINTER STRATOSPHERIC METEOROLOGY AND TRACER MORPHOLOGY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WIND MEASUREMENTS; ER-2; VORTEX; OZONE; RECONSTRUCTION; TEMPERATURE; EXPEDITION; TRENDS; WAVES; DC-8 AB Winter polar stratospheric nitric oxide (N2O) measurements made during two NASA polar aircraft field campaigns are used to evaluate the dynamics of the Geophysical Fluid Dynamics Laboratory's ''SKYHI'' general circulation model. SKYHI has 1-degrees latitude by 1.2-degrees longitude grid spacing and 40 vertical levels (up to 80 km) and prescribed N2O dissociation coefficients. The model has been integrated a total of 20 months, producing one Antarctic and two Arctic winters. The climatologies of these winters are compared with the known northern and southern hemisphere climatologies and to the meteorological conditions during the time of the field campaigns. The two Arctic SKYHI winters show considerable interannual variability. In the lower stratosphere, SKYHI realistically simulates the magnitude and variability of winds and temperatures both inside and outside the polar vortex and can produce a credible sudden warming. In the Antarctic the magnitude and variability of winds and temperatures around the polar vortex are quite realistic, but inside the vortex, temperatures are too low. Flight data from each mission have been averaged together to produce a contour map showing N2O morphology in and around the vortex. Because the N2O distribution in the lower stratosphere is under dynamical control, the mean N2O field can be used to interpret the dynamics of the polar stratosphere. At the Arctic vortex edge, AASE data show large gradients of N2O on isentropic surfaces. SKYHI vortex edge gradients are nearly as large, and model mixing ratios between 400 and 500 K (potential temperature) are similar to the observations. In the Antarctic, model mixing ratios are too high everywhere and the edge gradients are flatter than the observed gradients. The comparison of mean N2O fields suggests realistic wave activity in the SKYHI Arctic winter but inadequate wave activity in the SKYHI Antarctic winter. C1 PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08544 USA. NOAA, GEOPHYSICAL FLUID DYNAM LAB, PRINCETON, NJ USA. RI Strahan, Susan/H-1965-2012 NR 28 TC 29 Z9 30 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 MAY 20 PY 1994 VL 99 IS D5 BP 10305 EP 10318 DI 10.1029/93JD02332 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NN517 UT WOS:A1994NN51700001 ER PT J AU STRAHAN, SE MAHLMAN, JD AF STRAHAN, SE MAHLMAN, JD TI EVALUATION OF THE SKYHI GENERAL-CIRCULATION MODEL USING AIRCRAFT N2O MEASUREMENTS .2. TRACER VARIABILITY AND DIABATIC MERIDIONAL CIRCULATION SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB Winter polar stratospheric nitrous oxide (N2O) measurements made during two NASA polar aircraft field campaigns provide a unique opportunity to evaluate the performance of the 1-degrees latitude resolution version of the Geophysical Fluid Dynamics Laboratory's ''SKYHI'' general circulation model. This high-resolution model has been integrated 20 months, producing one Antarctic and two Arctic winters. Power spectra of the dynamically controlled tracer N2O are used as a diagnostic of wave activity. Comparison of the spectra of SKYHI and the observations shows that the SKYHI Arctic winter lower stratosphere is dynamically active enough to generate realistic mesoscale tracer variability but that the SKYHI Antarctic has deficient variability at scales of 220-3000 km. Low-pass filtering is applied to a new type of analysis that attempts to discriminate between different sources of atmospheric variability, to the extent that different sources are characterized by different timescales. The goal is to diagnose mesoscale sources of tracer variability in the model and in the observations and then to assess whether SKYHI generates variability for the right physical reasons. This analysis shows that variability from ''slow'' processes such as planetary wave breaking dominates and is generated in realistic amounts in the SKYHI Arctic winters. The SKYHI Antarctic vortex shows insufficient ''debris'' from planetary wave breaking at scales below 700 km. The balance between diabatic descent inside the vortex and wave breaking in the ''surf zone'' generates N2O gradients at the vortex edge in the model and the real atmosphere. Because the diabatic circulation is driven by wave activity, the strength of model wave activity diagnosed by the spectral analysis and the mean N2O gradients can be used to evaluate SKYHI's diabatic circulation and net tracer transport. In the Arctic, SKYHI temperatures, spectral results, and realistic N2O gradients at the vortex edge suggest a reasonable diabatic meridional circulation and transport. Antarctic spectral results, low vortex temperatures, and flatter N2O gradients at the edge all support the conclusion that the diabatic circulation and wave activity in the model southern hemisphere is too weak. C1 PRINCETON UNIV, ATMOSPHER & OCEAN SCI PROGRAM, PRINCETON, NJ 08544 USA. NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ USA. RI Strahan, Susan/H-1965-2012 NR 13 TC 27 Z9 27 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 MAY 20 PY 1994 VL 99 IS D5 BP 10319 EP 10332 DI 10.1029/94JD00044 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NN517 UT WOS:A1994NN51700002 ER PT J AU TYAHLA, LJ LOPEZ, RE AF TYAHLA, LJ LOPEZ, RE TI EFFECT OF SURFACE CONDUCTIVITY ON THE PEAK MAGNETIC-FIELD RADIATED BY 1ST RETURN STROKES IN CLOUD-TO-GROUND LIGHTNING SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHEASTERN COLORADO; DIRECTION FINDERS; PROPAGATION AB The effect of surface conductivity on the peak magnetic field radiated by the first return stroke in cloud-to-ground lightning was investigated by comparing the peak magnetic fields from return strokes that struck water with those that struck land. The data were obtained from a network of three gated, wideband magnetic direction finders (DFs) at the NASA Kennedy Space Center during the summer of 1985. Two geographical areas that were equidistant from two of the direction finders were compared where the flash distances ranged from approximately 40 to 60 km. An unbiased data set was obtained by correcting site errors, equalizing differences in sensor gain, eliminating directional biases in DF triggering, and keeping differences in signal attenuation over the two surfaces to a minimum. When a statistical analysis was performed on the frequency distributions of the signal amplitudes, there was no statistically significant difference in the peak amplitudes of first return strokes over land (lambda = 8.2 x 10(-3) Mho m-1) and over water (lambda = 4 mho m-1). Therefore we infer that the conductivity of the underlying surface does not significantly affect the magnitude of the peak magnetic field, and hence the peak current, in the first return stroke of a cloud-to-ground lightning flash. C1 NOAA, NATL SEVERE STORMS LAB, 1313 HALLEY CIRCLE, NORMAN, OK 73069 USA. RP TYAHLA, LJ (reprint author), UNIV ARIZONA, INST ATMOSPHER PHYS, TUCSON, AZ 85721 USA. NR 19 TC 4 Z9 4 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 MAY 20 PY 1994 VL 99 IS D5 BP 10517 EP 10525 DI 10.1029/94JD00384 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NN517 UT WOS:A1994NN51700017 ER PT J AU NAPPO, CJ VANDOP, H AF NAPPO, CJ VANDOP, H TI SIMPLE BOUNDARY-LAYER DESCRIPTION FOR GLOBAL DISPERSION MODELS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; TROPOSPHERIC OZONE AB A simple parameterization of the diurnally varying planetary boundary layer (PBL) is developed for use in global scale dispersion and air chemistry models. The parameterization captures the essential features of the convective and stable boundary layers and includes the effects of surface and volumetric sources of pollutants and trace gases. Initial tests are performed with a one-dimensional model. These tests show that the parameterization is mass conserving and gives realistic results. The volumetric source term can be used to model photochemical production of ozone in the convective PBL, and the surface source term can be used to model emissions such as radon or methane. C1 UNIV UTRECHT, INST MARINE & ATMOSPHER RES, DEPT PHYS & ASTRON, UTRECHT, NETHERLANDS. RP NAPPO, CJ (reprint author), NOAA, AIR RESOURCES LAB, DIV ATMOSPHER TURBULENCE & DIFFUS, OAK RIDGE, TN USA. NR 15 TC 3 Z9 3 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1994 VL 99 IS D5 BP 10527 EP 10534 DI 10.1029/94JD00317 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NN517 UT WOS:A1994NN51700018 ER PT J AU MATHUR, R SCHERE, KL NATHAN, A AF MATHUR, R SCHERE, KL NATHAN, A TI DEPENDENCIES AND SENSITIVITY OF TROPOSPHERIC OXIDANTS TO PRECURSOR CONCENTRATIONS OVER THE NORTHEAST UNITED-STATES - A MODEL STUDY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INCREMENTAL HYDROCARBON REACTIVITY; NITROGEN-OXIDES; OZONE PRODUCTION; MECHANISM AB Atmospheric distribution of photochemical oxidants has been a subject of interest and concern not only because of their deleterious effects on human health and vegetation but also because of their crucial role in determining the chemical composition of the atmosphere. Several important issues related to the distribution and production of photochemical species are examined through an analysis of results obtained from applications of a comprehensive three-dimensional regional scale photochemical model over the Northeast United States. The Regional Oxidant Model (ROM) is used to simulate the response of various photochemical species to specific anthropogenic emission strategies involving NO(x) and hydrocarbon reductions for an episodic period during July 1988. Domain and temporal averages of predicted concentrations are examined for various species. Their relative influence on oxidant chemistry over the modeled domain is investigated. Further, spatial distributions of O3 with respect to those of NO(x), NO(y) and hydrocarbons over the modeled domain are examined and the variations in O3 levels for different chemical regimes classified by characteristic NO(x)/reactive organic gases and NO(x)/NO(y) ratios are investigated. Temporal trends in domain-averaged concentrations indicate that the model replicates the expected diurnal trends in species concentrations. The relative benefits of reductions in NO(x) and hydrocarbon emissions on predicted O3 levels are also examined. In general, for this modeled domain, reductions in NO(x) emissions with or without reductions in hydrocarbon emissions have more impact on reducing predicted O3 levels compared to reductions only in hydrocarbon emissions. C1 NOAA, AIR RESOURCES LAB, DIV ATMOSPHER SCI MODELING, RES TRIANGLE PK, NC USA. CMP SCI CORP, RES TRIANGLE PK, NC USA. RP MATHUR, R (reprint author), MCNC N CAROLINA SUPERCOMP PROGRAM, ENVIRONM ROGRAMS, POB 12889, RES TRIANGLE PK, NC 27709 USA. NR 30 TC 14 Z9 14 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 MAY 20 PY 1994 VL 99 IS D5 BP 10535 EP 10552 DI 10.1029/93JD03580 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NN517 UT WOS:A1994NN51700019 ER PT J AU LEDBETTER, H LEI, M HERMANN, A SHENG, ZZ AF LEDBETTER, H LEI, M HERMANN, A SHENG, ZZ TI LOW-TEMPERATURE ELASTIC-CONSTANTS OF Y1BA2CU3O7 SO PHYSICA C LA English DT Article ID SUPERCONDUCTING TRANSITION; SINGLE-CRYSTALS; YBA2CU3O7-DELTA; PRESSURE AB Using ultrasonic methods, we studied the 4-295 K elastic constants of a ''good'' Y1Ba2Cu3O7 polycrystal. We report the bulk, shear, Young moduli and the Poisson ratio. Except for the Poisson ratio, all elastic constants show smooth temperature behavior. Near T(c), during cooling, the Poisson ratio decreases irregularly. Focusing on the bulk modulus B, we use simple thermodynamics to show that the harmonic-observed decrement at T=0 corresponds to expectation, but the temperature effect dB/dT is too large by about a factor of two. We attribute the irregular slope to oxygen-atom reordering. Against many reports, our bulk-modulus value is approximately that found in monocrystals or that predicted by an ionic-crystal model calculation. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV ARKANSAS,FAYETTEVILLE,AR 72701. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 29 TC 27 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAY 20 PY 1994 VL 225 IS 3-4 BP 397 EP 403 DI 10.1016/0921-4534(94)90741-2 PG 7 WC Physics, Applied SC Physics GA NP354 UT WOS:A1994NP35400027 ER PT J AU HUIE, RE AF HUIE, RE TI THE REACTION-KINETICS OF NO2 SO TOXICOLOGY LA English DT Article; Proceedings Paper CT Symposium on Effects of Exposure to Nitrogen Dioxide CY OCT 28, 1992 CL WALTER REED ARMY INST RES, WASHINGTON, DC HO WALTER REED ARMY INST RES DE FREE RADICALS; NITRIC OXIDE; NITROGEN DIOXIDE; NITROGEN OXIDES; REACTION KINETICS ID ELECTRON-TRANSFER-REACTIONS; GAS-PHASE REACTION; NITROGEN-DIOXIDE; NITRIC-OXIDE; AQUEOUS-SOLUTION; RATE CONSTANTS; PEROXY-RADICALS; INORGANIC RADICALS; PEROXYNITROUS ACID; CHLORINE DIOXIDE AB The chemistry of NO2. is reviewed. Experimental results from both the liquid and gas phase, and from both aqueous and non-aqueous systems, are used to gain insight into the basic chemistry of this radical. RP HUIE, RE (reprint author), NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. RI Huie, Robert/A-5645-2010; Weschler, Charles/A-9788-2009 OI Weschler, Charles/0000-0002-9097-5850 NR 97 TC 85 Z9 85 U1 3 U2 16 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD MAY 20 PY 1994 VL 89 IS 3 BP 193 EP 216 DI 10.1016/0300-483X(94)90098-1 PG 24 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA NU842 UT WOS:A1994NU84200003 PM 8023329 ER PT J AU NGUYEN, NV CHANDLERHOROWITZ, D AMIRTHARAJ, PM PELLEGRINO, JG AF NGUYEN, NV CHANDLERHOROWITZ, D AMIRTHARAJ, PM PELLEGRINO, JG TI SPECTROSCOPIC ELLIPSOMETRY DETERMINATION OF THE PROPERTIES OF THE THIN UNDERLYING STRAINED SI LAYER AND THE ROUGHNESS AT SIO2/SI INTERFACE SO APPLIED PHYSICS LETTERS LA English DT Article ID SI-SIO2 INTERFACE; OPTICAL EVIDENCE; SILICON; SURFACES; STRESS; OXIDE; GAAS AB The existence of both the strain and microroughness at the interface of thermally grown SiO2 films on Si was ascertained unambiguously for the first time by high accuracy spectroscopic ellipsometry. The dielectric function of the interface was determined by a comprehensive data analysis procedure. By carefully examining the dielectric function obtained by our model, the strain was seen to cause a red shift of 0.042 eV of the interband critical point E1 compared with the bulk silicon value. The thickness of the interface region was found to be 2.2 nm of which a significant part is due to the strain. RP NGUYEN, NV (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899, USA. NR 15 TC 49 Z9 50 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 16 PY 1994 VL 64 IS 20 BP 2688 EP 2690 DI 10.1063/1.111492 PG 3 WC Physics, Applied SC Physics GA NL618 UT WOS:A1994NL61800024 ER PT J AU SPREEUW, RJC GERZ, C GOLDNER, LS PHILLIPS, WD ROLSTON, SL WESTBROOK, CI REYNOLDS, MW SILVERA, IF AF SPREEUW, RJC GERZ, C GOLDNER, LS PHILLIPS, WD ROLSTON, SL WESTBROOK, CI REYNOLDS, MW SILVERA, IF TI DEMONSTRATION OF NEUTRAL ATOM TRAPPING WITH MICROWAVES SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-POLARIZED HYDROGEN; MAGNETIC TRAP; RADIATION AB We demonstrate trapping of neutral Cs atoms by the magnetic dipole force due to a microwave field. The trap is formed in a spherical microwave cavity tuned near the ground state hyperfine transition (9.193 GHz). With a microwave power of 83 W, the trap is almost-equal-to 0.1 mK deep. It is loaded with Cs atoms laser cooled to almost-equal-to 4 muK. We observe oscillatory motion of atoms in the trap at frequencies of 1-3 Hz. This type of trap has certain advantages for achieving the conditions for Bose-Einstein condensation in hydrogen or the alkalis, because it can confine atoms predominantly in the lowest energy spin state. C1 HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138. RP SPREEUW, RJC (reprint author), NATL INST STANDARDS & TECHNOL,PHY A-167,GAITHERSBURG,MD 20899, USA. RI Westbrook, Christoph/B-6092-2009; rolston, steven/L-5175-2013; Spreeuw, Robert/B-7571-2008 OI Westbrook, Christoph/0000-0002-6490-0468; rolston, steven/0000-0003-1671-4190; Spreeuw, Robert/0000-0002-2631-5698 NR 13 TC 59 Z9 60 U1 0 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 MAY 16 PY 1994 VL 72 IS 20 BP 3162 EP 3165 DI 10.1103/PhysRevLett.72.3162 PG 4 WC Physics, Multidisciplinary SC Physics GA NL609 UT WOS:A1994NL60900008 ER PT J AU SANDER, LC SHARPLESS, KE CRAFT, NE WISE, SA AF SANDER, LC SHARPLESS, KE CRAFT, NE WISE, SA TI DEVELOPMENT OF ENGINEERED STATIONARY PHASES FOR THE SEPARATION OF CAROTENOID ISOMERS SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; POLYCYCLIC AROMATIC-HYDROCARBONS; TRACE-METAL ACTIVITY; REVERSED-PHASE; COLUMN SELECTIVITY; HPLC SEPARATION; BETA-CAROTENE; RETENTION MECHANISMS; CALCIUM HYDROXIDE; BONDING DENSITY AB A variety of bonded phase parameters (endcapping, phase chemistry, ligand length, and substrate parameters) were studied for their effect on column retention and selectivity toward carotenoids. Decisions were made on how each of these variables should be optimized based on the separation of carotenoid and polycyclic aromatic hydrocarbon test probes. A column was designed with the following properties: high absolute retention, enhanced shape recognition of structured solutes, and moderate silanol activity. These qualities were achieved by triacontyl (C-30) polymeric surface modification of a moderate pore size (similar to 20 nm), moderate surface area (similar to 200 m(2)/g) silica, without subsequent endcapping. The effectiveness of this ''carotenoid phase'' was demonstrated for the separation of a mixture of structurally similar carotenoid standards, an extract of a food matrix Standard Reference Material, and a p-carotene dietary supplement under consideration as an agent for cancer intervention/prevention. RP SANDER, LC (reprint author), NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. OI Sharpless, Katherine/0000-0001-6569-198X NR 65 TC 278 Z9 288 U1 0 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 15 PY 1994 VL 66 IS 10 BP 1667 EP 1674 DI 10.1021/ac00082a012 PG 8 WC Chemistry, Analytical SC Chemistry GA NL329 UT WOS:A1994NL32900015 PM 15943024 ER PT J AU BENNETT, LH MCMICHAEL, RD TANG, HC WATSON, RE AF BENNETT, LH MCMICHAEL, RD TANG, HC WATSON, RE TI MONTE-CARLO SIMULATIONS OF THE MAGNETOCALORIC EFFECT IN SUPERFERROMAGNETIC CLUSTERS HAVING UNIAXIAL MAGNETIC-ANISOTROPY SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB The magnetic entropy change, DELTAS (hence the heating or cooling) of ferromagnetically coupled magnetic clusters induced by an application of a magnetic field is substantial and occurs over a broad temperature range. This behavior contrasts with a ferromagnetic material, where larger entropy changes can be obtained, but only over small temperature ranges close to the Curie point. Monte Carlo simulations have been carried out to obtain DELTAS when the spins are subjected to uniaxial anisotropy fields. While previous calculations for interacting spins showed increases in the Curie temperature and enhancements of DELTAS in the vicinity of the Curie point with increasing anisotropy, the present results for interacting clusters show similar increases in the temperature of DELTAS peaks accompanied by decreases in the peak values of DELTAS. These results show that the flattening of the DELTAS peaks, which make superferromagnetic materials valuable for magnetic refrigeration is assisted by the presence of uniaxial anisotropy. Some effects on DELTAS of placing the spins on fixed BCC, FCC, and sc lattices are reported. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP BENNETT, LH (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI C, Y/G-5456-2010; McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 10 TC 22 Z9 23 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 5493 EP 5495 DI 10.1063/1.355667 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400008 ER PT J AU MCMICHAEL, RD AF MCMICHAEL, RD TI METHOD FOR DETERMINING BOTH MAGNETOSTRICTION AND ELASTIC-MODULUS BY FERROMAGNETIC-RESONANCE SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID FILMS; CONSTANTS AB The magnetostriction constant lambda(s) includes a combination of both elastic constants c(ij) and magnetoelastic coupling constants B(i). To provide information on both c(ij) and B(i), a method for measurement of both lambda(s) and the elastic modulus Y of thin films has been developed using ferromagnetic resonance (FMR). As in prior FMR schemes for measuring lambda(s), a strain is produced in the film by bending the substrate, and the resulting anisotropy field is measured. However, by using a triangular polymer beam as a substrate, three important advantages are obtained (i) the triangular beam shape has uniform strain along its surface, (ii) the polymer material supports large strains (>10(-3)) without breaking, and (iii) the low elastic modulus of the beam allows measurement of the sample elastic modulus through variation of the sample aspect ratio. Measurements on Ni foils yield values of lambda(s) and Y which fall within the scatter of literature data. RP MCMICHAEL, RD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 15 TC 4 Z9 4 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 5650 EP 5652 DI 10.1063/1.355625 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400069 ER PT J AU VAJDA, F DELLATORRE, E MCMICHAEL, RD AF VAJDA, F DELLATORRE, E MCMICHAEL, RD TI DEMAGNETIZED-STATE DEPENDENCE OF HENKEL PLOTS .1. THE PREISACH MODEL SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID RECORDING MEDIA; REMANENT MAGNETIZATION; PARTICULATE AB The interpretation of interaction through Henkel plots and DELTAm plots has become popular in recent years; however, the demagnetized state is often not specified. In this paper, the demagnetized state dependence of Henkel plots is calculated using the classical Preisach model, the moving.model, and the complete-moving-hysteresis model. In the calculation of the virgin remanence curve, ac, dc+, and dc- demagnetized states were used. The resulting collection of Henkel plots contains examples of ''up'' and ''down'' deviations from the Wohlfarth line by changing the demagnetized state only. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP VAJDA, F (reprint author), GEORGE WASHINGTON UNIV,INST MAGNET RES,WASHINGTON,DC 20052, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 17 TC 80 Z9 81 U1 2 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 5689 EP 5691 DI 10.1063/1.355638 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400082 ER PT J AU MCMICHAEL, RD VAJDA, F DELLATORRE, E AF MCMICHAEL, RD VAJDA, F DELLATORRE, E TI DEMAGNETIZED-STATE DEPENDENCE OF HENKEL PLOTS .2. DOMAIN-WALL MOTION SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID FILM RECORDING MEDIA; PREISACH MODEL; PARTICULATE; HYSTERESIS AB The interpretation of various magnetization curves through Henkel plots and DELTAm plots as become popular in recent years for characterization of interactions in hysteresis. To investigate this approach, we have calculated Henkel plots using a hysteresis model based on independently moving domain walls. A variety of demagnetized states produced by ac, dc+, and dc-demagnetization methods as well as microscopically and randomly demagnetized states are used to calculate m(r)(H). The resulting collection of Henkel plots contains examples of both ''positive'' and ''negative'' deviations from the Wohlfarth relation which depend on the demagnetization method. Also, the Henkel plot calculated for the ac demagnetized state deviates from the square-root law previously calculated for domain wall pinning using a classical Preisach model. C1 GEORGE WASHINGTON UNIV,INST MAGNET RES,WASHINGTON,DC 20052. RP MCMICHAEL, RD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 14 TC 16 Z9 16 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 5692 EP 5694 DI 10.1063/1.355639 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400083 ER PT J AU GEHRING, PM HIROTA, K MAJKRZAK, CF SHIRANE, G AF GEHRING, PM HIROTA, K MAJKRZAK, CF SHIRANE, G TI DEPTH-DEPENDENT MAGNETIC CORRELATION LENGTH IN TERBIUM SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP GEHRING, PM (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 5959 EP 5959 DI 10.1063/1.355526 PN 2A PG 1 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400183 ER PT J AU LYNN, JW ROSOV, N ACET, M BACH, H AF LYNN, JW ROSOV, N ACET, M BACH, H TI POLARIZATION ANALYSIS OF THE MAGNETIC EXCITATIONS IN FE65NI35 INVAR SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID LONGITUDINAL FLUCTUATIONS; ISOTROPIC FERROMAGNET AB Triple-axis inelastic polarized neutron measurements have been performed as a function of temperature on a single crystal of the Invar alloy Fe65Ni35 to distinguish longitudinal from transverse magnetic excitations in the magnetically ordered phase. Well below the Curie temperature of 501 K the magnetic excitation spectrum is dominated by conventional transverse spin-wave excitations, which in fact follow the predictions of spin-wave theory very well. In particular, we find no evidence for propagating longitudinal excitations in this system, in sharp contrast to the behavior observed in the amorphous Invar Fe86B14 material as well as the non-Invar amorphous system Fe40Ni40P14B6. C1 UNIV DUISBURG,W-4100 DUISBURG,GERMANY. RUHR UNIV BOCHUM,W-4630 BOCHUM,GERMANY. UNIV MARYLAND,COLL PK,MD 20742. RP LYNN, JW (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. RI Acet, Mehmet/F-4442-2012 NR 14 TC 20 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6069 EP 6071 DI 10.1063/1.355460 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400221 ER PT J AU ROSOV, N LYNN, JW KASTNER, J WASSERMANN, EF CHATTOPADHYAY, T BACH, H AF ROSOV, N LYNN, JW KASTNER, J WASSERMANN, EF CHATTOPADHYAY, T BACH, H TI TEMPERATURE-DEPENDENCE OF THE MAGNETIC EXCITATIONS IN ORDERED AND DISORDERED FE72PT28 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID INVAR ALLOY; FE3PT AB We have performed inelastic neutron scattering measurements of the long-wavelength spin wave excitations of both ordered and disordered Fe72Pt28 single crystals below their critical temperatures, T(C)=510 and 375 K, respectively. The spin waves followed the expected E=Dq2 dependence,and the temperature-dependent spin stiffness D decreased as (T/T(C))5/2, as expected for an isotropic ferromagnet. The extrapolated zero-temperature spin stiffness was D = 98(4) meV angstrom2 and 107(1) meV angstrom2 for the disordered and ordered alloy, respectively. These values are significantly higher than the zero-temperature stiffness as determined by magnetization measurements. C1 UNIV DUISBURG,D-47057 DUISBURG,GERMANY. RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV MARYLAND,COLL PK,MD 20742. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP ROSOV, N (reprint author), NAT INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 10 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6072 EP 6074 DI 10.1063/1.355461 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400222 ER PT J AU PECHAN, MJ ANKNER, JF MAJKRAZK, CF KELLY, DM SCHULLER, IK AF PECHAN, MJ ANKNER, JF MAJKRAZK, CF KELLY, DM SCHULLER, IK TI MAGNETIC PROFILE AS A FUNCTION OF STRUCTURAL DISORDER IN FE/CR SUPERLATTICES SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID GIANT MAGNETORESISTANCE; INTERLAYER EXCHANGE; NEUTRON-DIFFRACTION; FE LAYERS; MULTILAYERS; ROUGHNESS; CR AB Structural disorder has been systematically introduced in an [Fe(30 angstrom)/Cr(17 angstrom)]10 superlattice to investigate its effects on the magnetization profile. Low angle x-ray and neutron scattering results indicate progressive structural degradation in samples produced with increased argon pressure (3, 6, and 12 mTorr). The x-ray spectra from the more disordered samples are characterized by a decreased intensity and increased linewidth of the superlattice Bragg peaks, along with a systematic disappearance of the finite size intensity oscillations. Elastic, polarized, low angle, neutron reflectivity data exhibit decreasing superlattice Bragg intensities and increasing linewidths, indicating increased disorder in agreement with x-ray data. Antiferromagnetic alignment of adjacent Fe layers is inferred by the appearance of magnetic peaks between the structural peaks and by the lack of magnetic contribution to the structural superlattice peaks. Interestingly, the magnetic superlattice peak does not exhibit appreciable degradation with increasing disorder in the structure, indicating a magnetic coherence length significantly greater than that of the chemical superlattice structure. C1 NIST,GAITHERSBURG,MD 20899. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RP PECHAN, MJ (reprint author), MIAMI UNIV,DEPT PHYS,OXFORD,OH 45056, USA. OI Ankner, John/0000-0002-6737-5718 NR 15 TC 13 Z9 13 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 MAY 15 PY 1994 VL 75 IS 10 BP 6178 EP 6180 DI 10.1063/1.355448 PN 2A PG 3 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400263 ER PT J AU SCHAFER, M WOLF, JA GRUNBERG, P ANKNER, JF SCHREYER, A ZABEL, H MAJKRZAK, CF AF SCHAFER, M WOLF, JA GRUNBERG, P ANKNER, JF SCHREYER, A ZABEL, H MAJKRZAK, CF TI GROWTH TEMPERATURE-DEPENDENCE OF BIQUADRATIC COUPLING IN FE/CR(100) SUPERLATTICES STUDIED BY POLARIZED NEUTRON REFLECTIVITY AND X-RAY-DIFFRACTION SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 RUHR UNIV BOCHUM,FAK PHYS & ASTRON,W-4630 BOCHUM,GERMANY. RP SCHAFER, M (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. RI Zabel, Hartmut/C-1994-2009 NR 0 TC 3 Z9 3 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 MAY 15 PY 1994 VL 75 IS 10 BP 6193 EP 6193 PN 2A PG 1 WC Physics, Applied SC Physics GA NN734 UT WOS:A1994NN73400268 ER PT J AU CROSS, RW KOS, AB AF CROSS, RW KOS, AB TI LOCAL MAGNETORESISTANCE AND POINT-SOURCE EXCITATION OF NI-FE THIN-FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract RP CROSS, RW (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6400 EP 6400 DI 10.1063/1.355363 PN 2B PG 1 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600067 ER PT J AU UNGURIS, J CELOTTA, RJ PIERCE, DT AF UNGURIS, J CELOTTA, RJ PIERCE, DT TI OSCILLATORY EXCHANGE COUPLING IN FE/AU/FE(100) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID FE AB Scanning electron microscopy with polarization analysis was used to investigate the interlayer exchange coupling in Fe/Au/Fe(100) sandwich structures. The films were epitaxially grown on single-crystal Fe(100) substrates. Electron diffraction measurements revealed that the Au spacer film grew with a surface reconstruction consistent with that observed for bulk Au crystals. The exchange coupling oscillates between primarily ferromagnetic and antiferromagnetic coupling for Au spacer layers up to 65 layers (13 nm) thick, but a significant biquadratic coupling component was also observed. The oscillatory coupling exhibited two components with periods of 2.48+/-0.05 layers (0.506+/-0.010 nm) and 8.6+/-0.3 layers (1.75+/-0.06 nm). The measured periods are in excellent agreement with those calculated from spanning vectors of the Au Fermi surface. RP UNGURIS, J (reprint author), NIST,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Unguris, John/J-3989-2014 NR 11 TC 70 Z9 70 U1 1 U2 6 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 MAY 15 PY 1994 VL 75 IS 10 BP 6437 EP 6439 DI 10.1063/1.356954 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600083 ER PT J AU CELOTTA, RJ UNGURIS, J PIERCE, DT AF CELOTTA, RJ UNGURIS, J PIERCE, DT TI HOT-ELECTRON SPIN-VALVE EFFECT IN COUPLED MAGNETIC LAYERS SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID SECONDARY ELECTRONS; TRANSITION-METALS; POLARIZATION; TRANSMISSION; DIFFRACTION; GROWTH AB SEMPA observations of magnetic exchange coupling in the Fe/Ag/Fe, Fe/Au/Fe, and Fe/Cr/Fe systems reveal an intensity variation in the emitted secondary electron signal that depends only on whether the Fe layers are coupled in a ferromagnetic or antiferromagnetic sense. We ascribe this new effect to spin dependence in the transport of electrons between the two magnetic layers. RP CELOTTA, RJ (reprint author), NIST,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. RI Unguris, John/J-3989-2014 NR 17 TC 11 Z9 11 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 MAY 15 PY 1994 VL 75 IS 10 BP 6452 EP 6454 DI 10.1063/1.356959 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600088 ER PT J AU LEE, WT KAISER, H RHYNE, JJ DUMESNIL, K DUFOUR, C MANGIN, P MARCHAL, G AF LEE, WT KAISER, H RHYNE, JJ DUMESNIL, K DUFOUR, C MANGIN, P MARCHAL, G TI EXCHANGE COUPLING IN [DY-VERTICAL-BAR-ER] METALLIC SUPERLATTICES SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB Magnetic exchange coupling in metallic superlattices of [Dy\Er], grown by molecular-beam epitaxy, has been examined by neutron diffraction. In a superlattice of 65-angstrom layers of Dy and 55-angstrom layers of Er, distinct ordering temperatures were observed for the Dy and Er layers. Basal plane helical ordering of the Dy layers was initiated at temperatures close to T(N) for bulk Dy (178 K) with a long-range interaction, preserving both phase and chirality, mediated through the Er layers. At a temperature near 70 K, the helical coupling of the Dy spins is replaced by an antiferromagnetic coupling of adjacent ferromagnetically ordered Dy layers coexisting with a remanent helical order. At a temperature well below T(N) of bulk Er, c-axis ordering of the Er spins occurs in the superlattice, and in measurements at 10 K there is evidence of basal plane moment ordering in the Er. C1 UNIV NANCY 1,PHYS SOLIDE LAB,F-54506 VANDOEUVRE NANCY,FRANCE. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP LEE, WT (reprint author), UNIV MISSOURI,CTR RES REACTOR,COLUMBIA,MO 65211, USA. NR 2 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6477 EP 6479 DI 10.1063/1.357035 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600099 ER PT J AU BORCHERS, JA ANKNER, JF MAJKRZAK, CF ENGEL, BN WIEDMANN, MH VANLEEUWEN, RA FALCO, CM AF BORCHERS, JA ANKNER, JF MAJKRZAK, CF ENGEL, BN WIEDMANN, MH VANLEEUWEN, RA FALCO, CM TI SPATIAL MODULATION OF THE MAGNETIC-MOMENT IN CO/PD SUPERLATTICES OBSERVED BY POLARIZED NEUTRON REFLECTIVITY SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID INTERFACE AB We have measured the specular reflectivity of spin-polarized neutrons from two (111) superlattices, [Pd 80 angstrom\Co 60 angstrom] x 20/Pd 300 angstrom/Co 10 angstrom/GaAs and [Pd 53 angstrom\Co 32 angstrom]x 10/Pd 30 angstrom/Cu 354 angstrom/Si, grown by molecular-beam epitaxy. In a saturating field of 2300 Oe, we extract for the first superlattice a Co moment value of corresponding to 78% of the bulk Co moment. At temperatures ranging from 38 to 295 K, no excess magnetic moment from polarization of the Pd atoms is evident in the nominal Pd layer. Comparable reflectivity data from the second sample support these conclusions. C1 UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. RP BORCHERS, JA (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. OI Ankner, John/0000-0002-6737-5718 NR 11 TC 2 Z9 2 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 MAY 15 PY 1994 VL 75 IS 10 BP 6498 EP 6500 DI 10.1063/1.356949 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600106 ER PT J AU OTI, JO RUSSEK, SE SANDERS, SC AF OTI, JO RUSSEK, SE SANDERS, SC TI MAGNETIC AND MAGNETORESISTIVE PROPERTIES OF INHOMOGENEOUS MAGNETIC DUAL-LAYER FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID MICROMAGNETIC MODEL AB Magnetic and magnetoresistive properties of sputtered Co alloy dual-layer films are compared with micromagnetic simulations. The simulations elucidate the details of the switching behavior of the dual-layer films as a function of the interlayer exchange and magnetostatic interactions. The simulations have led to a conceptual understanding of the coercive field splitting caused by the interlayer interactions. A calculation of the anisotropic magnetoresistance (AMR) has been included in the simulations. The AMR provides a second independent macroscopic quantity (in addition to the average magnetization) which can be measured and compared with the micromagnetic simulations. The AMR is more sensitive to the micromagnetic structure perpendicular to the applied field and is a better test of the accuracy of the micromagnetic model. The simulations qualitatively describe the measured AMR data on CoNi-Cr-CoNi dual layers. RP OTI, JO (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6519 EP 6521 DI 10.1063/1.356934 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600117 ER PT J AU ROBINSON, RA LYNN, JW LAWSON, AC NAKOTTE, H AF ROBINSON, RA LYNN, JW LAWSON, AC NAKOTTE, H TI TEMPERATURE-DEPENDENCE OF MAGNETIC ORDER IN SINGLE-CRYSTALLINE UPDSN SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB The noncollinear hexagonal antiferromagnet UPdSn exhibits two magnetic phase transitions, at 35.5 and 23 K The first transition is from a hexagonal paramagnetic state to a noncollinear antiferromagnetic state with a doubled unit cell (phase 1). The second 23-K transition is to a monoclinic magnetic structure (phase II). Ever since these transitions were discovered, the question has been whether the moments simply rotate at 23 K, or whether the y and z components of the moment order at 35.5 K while the x component orders out of incipient fluctuations at the lower 23-K transition. While previous powder studies were rather inconclusive on this point, in this study new single-crystal neutron-diffraction results are presented that show the second picture to be correct. In addition, the structural distortions that accompany the change in symmetry are discussed and show that there is phase-II type magnetic short-range order between 23 and 35.5 K C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. UNIV AMSTERDAM,VAN DER WAALS ZEEMAN LAB,1018 XE AMSTERDAM,NETHERLANDS. RP ROBINSON, RA (reprint author), LOS ALAMOS NATL LAB,LANSCE,LOS ALAMOS,NM 87545, USA. NR 10 TC 11 Z9 11 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 MAY 15 PY 1994 VL 75 IS 10 BP 6589 EP 6591 DI 10.1063/1.356904 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600143 ER PT J AU EVERITT, BA SALAMON, MB FLYNN, CP PARK, BJ BORCHERS, JA ERWIN, RW TSUI, F AF EVERITT, BA SALAMON, MB FLYNN, CP PARK, BJ BORCHERS, JA ERWIN, RW TSUI, F TI MAGNETIC-PROPERTIES OF DY-LU ALLOYS SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Although many binary heavy rare-earth alloy systems have been studied extensively, there has been little work reported on the Dy-Lu system. The properties of single-crystal DyxLu1-x films grown by molecular beam epitaxy are reported. SQUID magnetometer and neutron diffraction measurements on samples with x=0.4, 0.5, and 0.6 show that the samples order helimagnetically with Neel temperatures of T(N)=90, 105, and 120 K, respectively. The helical turn angle was mapped as a function of temperature for each of the three alloys. Magnetic x-ray scattering, the first in an alloy, was observed at the (002)+/- positions at 15 and 60 K in the x=0.4 sample using resonant exchange scattering of synchrotron radiation at the Dy L(III) edge. C1 NIST, GAITHERSBURG, MD 20899 USA. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. RP UNIV ILLINOIS, URBANA, IL 61801 USA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6592 EP 6594 DI 10.1063/1.356905 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600144 ER PT J AU WU, SY HSIEH, WT LI, WH LEE, KC LYNN, JW YANG, HD AF WU, SY HSIEH, WT LI, WH LEE, KC LYNN, JW YANG, HD TI 2-DIMENSIONAL MAGNETIC ORDER IN PB2SR2TBCU3O8 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID ERBA2CU3O7; IONS; ER; DY AB Neutron diffraction techniques have been used to investigate the magnetic ordering of the Tb ions in polycrystalline Pb2Sr2TbCu3O8. Significant magnetic correlations are found to develop below approximately 10 K, and these correlations are two dimensional in nature, representative of the strongly anisotropic magnetic interactions in these layered materials. The correlation length increases with decreasing temperature, and long-range order is observed to develop at T(N) almost-equal-to 5.5 K. However, the sawtooth Bragg profile for the scattering demonstrates that the long-range order is two dimensional, rather than three dimensional, with a spin configuration where nearest-neighbor spins are antiparallel The scattering profile can be explained quantitatively by assuming long-range order within the ab plane, with no significant correlations along the c axis to the lowest temperatures measured (1.36 K). Our results suggest that the system is well described by a two-dimensional Ising model. The only other (pure) system where a crossover to three-dimensional behavior is not observed is DyBa2Cu4O8. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. NATL SUN YAT-SEN UNIV,DEPT PHYS,KAOHSIUNG 80424,TAIWAN. RP WU, SY (reprint author), NATL CENT UNIV,DEPT PHYS,CHUNGLI 32054,TAIWAN. NR 10 TC 21 Z9 21 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 MAY 15 PY 1994 VL 75 IS 10 BP 6598 EP 6600 DI 10.1063/1.356907 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600146 ER PT J AU BERRY, SD BORCHERS, JA ERWIN, RW LIND, DM SHAW, KA LOCHNER, E AF BERRY, SD BORCHERS, JA ERWIN, RW LIND, DM SHAW, KA LOCHNER, E TI STUDIES OF THE VERWEY TRANSITION IN FE3O4/NIO SUPERLATTICES BY SQUID MAGNETOMETRY AND NEUTRON-DIFFRACTION TECHNIQUES SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 FLORIDA STATE UNIV,MARTECH,TALLAHASSEE,FL 32306. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP BERRY, SD (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6691 EP 6691 DI 10.1063/1.356897 PN 2B PG 1 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600184 ER PT J AU LYNN, JW AF LYNN, JW TI MAGNETIC NEUTRON-SCATTERING SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB The application of neutron scattering techniques to magnetic problems is reviewed. We will first discuss diffraction techniques used to solve magnetic structures, as well as to measure magnetic form factors, order parameters, critical phenomena, and the scattering from low-dimensional systems. We will also discuss inelastic scattering techniques, including polarized beam methods, utilized to determine the spin dynamics of various materials. Information will be provided about the types of spectrometers available at the user-oriented national facilities located at Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, The National Institute of Standards and Technology, and Oak Ridge National Laboratory, as well as the spectrometers at the Missouri University Research Reactor. RP LYNN, JW (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 14 TC 3 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6806 EP 6910 DI 10.1063/1.356839 PN 2B PG 105 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600235 ER PT J AU SHULL, RD KERCH, HM RITTER, JJ AF SHULL, RD KERCH, HM RITTER, JJ TI MAGNETIC-PROPERTIES OF COLLOIDAL SILICA - POTASSIUM SILICATE GEL IRON NANOCOMPOSITES SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB Homogeneous composites of Fe and silica containing 5-40 wt % Fe have been prepared by infiltration of ferric nitrate solution into a colloidal silica: potassium silicate gel at room temperature. Previous electron microscopy, small angle neutron scattering, and nitrogen sorption (BET) measurements on such gels have shown they are comprised of an interconnected silica matrix, having pores ranging from 2-800 nm in size. Mossbauer effect and magnetization data show the Fe is in a paramagnetic environment with weak antiferromagnetic interactions. Curie-Weiss analysis indicated negative intercepts of the temperature axis for all the samples and that the magnetic moment per Fe atom (mu(Fe)) decreased as the Fe content increased at a rate of -0.0058 mu(B)/% Fe. For most of the samples mu(Fe) almost-equal-to-2.1 mu(B). By contrast, in silica gel/Fe nanocomposites formed by the polymerization of an aqueous solution of tetraethoxysilane and iron nitrate, the Fe possessed magnetic moments varying from 3.9 to 2.9 mu(B). It is suggested that the difference is a result of the different pore structures of the gels, and not due to the different methods (e.g., postmatrix infiltration as compared to premixing prior to matrix polymerization) used to introduce the Fe. RP SHULL, RD (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Shull, Robert/F-5971-2013 NR 11 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6840 EP 6842 DI 10.1063/1.356802 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600247 ER PT J AU RICE, P MORELAND, J WADAS, A AF RICE, P MORELAND, J WADAS, A TI DC MAGNETIC FORCE MICROSCOPY IMAGING OF THIN-FILM RECORDING HEAD SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC AB Using a new form of magnetic force microscope (dc MFM) magnetic force images of a thin-film recording head have been made. Using dc MFM, atomic force microscope images are presented of the surface topography and magnetic forces taken simultaneously, allowing direct correlation of magnetic fields to the pole pieces. Magnetic force images of the head at typical head-to-disk spacings are presented. The tips used for these images had two different magnetic coatings. RP RICE, P (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 9 TC 12 Z9 12 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6878 EP 6880 DI 10.1063/1.356978 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600260 ER PT J AU OTI, JO RICE, P RUSSEK, SE AF OTI, JO RICE, P RUSSEK, SE TI PROPOSED ANTIFERROMAGNETICALLY COUPLED DUAL-LAYER MAGNETIC FORCE MICROSCOPE TIPS SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Conference on Magnetism and Magnetic Materials (MMM 93) CY NOV 15-18, 1993 CL MINNEAPOLIS, MN SP AMER INST PHYS, MAGNET SOC, IEEE, MINERALS MET & MAT SOC, AMER SOC TESTING & MAT, USN, OFF NAVAL RES, AMER CERAM SOC ID MAGNETORESISTANCE; OSCILLATIONS AB A magnetic force microscope tip designed from dual-layer magnetic films of antiferromagnetically coupled magnetic layers is proposed. A theoretical analysis of the possible advantages of such a tip over conventional single-layer tips is given, using an extension to dual layers of a previously described micromagnetic model of single-layer tips. In contrast to single-layer tips, the magnetic domains of dual-layer tips are less sensitive to the fringing fields of the specimen, and the tips' stray fields are greatly reduced, thus minimizing the likelihood of erasure of the sample magnetization. These properties of dual-layer tips should lead to improved resolution of magnetic force microscopy images. RP OTI, JO (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 6 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1994 VL 75 IS 10 BP 6881 EP 6883 DI 10.1063/1.356815 PN 2B PG 3 WC Physics, Applied SC Physics GA NN736 UT WOS:A1994NN73600261 ER PT J AU DOMENECH, JL ANDREWS, AM BELOV, SP FRASER, GT LAFFERTY, WJ AF DOMENECH, JL ANDREWS, AM BELOV, SP FRASER, GT LAFFERTY, WJ TI INFRARED DIODE-LASER SPECTRA OF THE NU(9) AND NU(11) N-O STRETCHING BANDS OF N2O4 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SUPERSONIC JET EXPANSIONS; RESOLUTION FTIR SPECTRA; TRANSITION FREQUENCIES; ROVIBRATIONAL ANALYSIS; DINITROGEN TETROXIDE; LINE STRENGTHS; N2O4; SPECTROSCOPY; TEMPERATURE; MATRIX AB The rotationally resolved jet-cooled infrared spectra of the b-type nu(9) (b(2u)) fundamental band at 1757 cm(-1) and the a-type nu(11) (b(3u)) fundamental band at 1261 cm(-1) of the N-O stretches of N2O4 have been recorded with a diode laser. The vg band was found to be unperturbed, and it was possible to assign nearly 100% of the observed lines with-a signal to noise greater than 2. In contrast, most of the K-a states of the nu(11) band were found to be strongly perturbed. A large number of strong lines (approximate to 20%) are unassigned and presumably arise from the perturbing state as well as torsional hot band transitions. The rotational analysis yields precise spectroscopic constants for the ground vibrational state which are interpreted in terms of a planar centrosymmetric dimer with a N-N bond length of 1.756(10) Angstrom. The observed nuclear-spin statistical weights and near-zero inertial defect are consistent with the planar centrosymmetric structure determined in earlier electron-diffraction studies. C1 APPL PHYS INST,MOLEC SPECT LAB,NIZHNII NOVGOROD 603024,RUSSIA. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RI Domenech, Jose/F-5561-2013 OI Domenech, Jose/0000-0001-8629-2566 NR 39 TC 23 Z9 23 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1994 VL 100 IS 10 BP 6993 EP 6999 DI 10.1063/1.466900 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NL685 UT WOS:A1994NL68500001 ER PT J AU SCHUDER, MD NESBITT, DJ AF SCHUDER, MD NESBITT, DJ TI HIGH-RESOLUTION NEAR-INFRARED SPECTROSCOPY OF HCL-DCL AND DCL-HCL - RELATIVE BINDING-ENERGIES, ISOMER INTERCONVERSION RATES, AND MODE-SPECIFIC VIBRATIONAL PREDISSOCIATION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HYDROGEN-FLUORIDE DIMER; HF DIMER; LASER SPECTROSCOPY; SUPERSONIC JETS; STRETCHING FUNDAMENTALS; SPECTRUM; (HF)2; MICROWAVE; STATE; DYNAMICS AB Both D- and H-bonded isomers of the mixed dimers formed between HCl and DCl are investigated via high resolution infrared difference frequency and diode laser spectroscopy in the 2885 and 2064 cm(-1) regions. From an analysis of the relative integrated absorption intensities, the D-bonded complex (i.e., HCl-DCl) is determined to be more stable by 16+/-4 cm(-1) than the H-bonded (i.e., DCl-HCl) species. All four chlorine isotopic combinations of the lower energy (HCl-DCl) complex are probed via excitation of both HCl(v(acc)(HCl) = 1 <-- 0) and DCl (v(don)(DCl) = 1 <-- 0) stretches. Additionally, two chlorine isotopomers of the higher energy (DCl-HCl) complex are investigated through HCl excitation. Compared to the facile tunneling observed in both (HCl)(2) or (DCl)(2) complexes, these mixed dimers exhibit more rigid behaviour characteristic of two distinct isomeric species. However, the relatively small energy difference (16+/-4 cm(-1)) between the two isomers still allows the wave functions for both species to sample both the HCl-DCl and DCl-HCl local minima on the potential surface. This intermediate level of angular localization of the wave function is modeled via 3D quantum mechanical calculations including all three internal rotor angular degrees of freedom. Additionally, a 1D treatment along the minimum energy tunneling path is investigated, which quantifies the asymmetry in the tunneling coordinate due to isotopic dependence of the H- and D-bonded zero point bending and torsion energies. Vibrational predissociation lifetimes in excess of the slit jet instrument line shape are determined from homogeneous broadening of the spectral line widths. The HCl stretch excited lifetime of H-bonded DCl-HCl [Delta nu(don)(HCl) = 44(6) MHz, tau(don)(HCl) = 3.6(5) ns] is threefold shorter than the corresponding lifetime of D-bonded HCl-DCl [Delta nu(acc)(HCl) = 16(3) MHz, tau(acc)(HCl) = 9.6(16) ns]. This ratio is quite comparable to the results obtained in investigations of (HCl)2 and consistent with a stronger, mode specific coupling to the dissociation coordinate for excitation of the bonded-HX vs free-HX moiety. However, the absolute lifetimes of both v(acc)(HCl) = 1 HCl-DCl and vdonHCl = 1 DCl-HCl complexes are tenfold shorter than the corresponding excited vibrational state lifetimes in (HCl)(2). This suggest a near resonant channel for predissociation into HCl(v = 0) + DCl(v = 1) which minimizes the energy deposited into rotation and relative translation of the diatomic fragments. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 45 TC 33 Z9 33 U1 3 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1994 VL 100 IS 10 BP 7250 EP 7267 DI 10.1063/1.466872 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NL685 UT WOS:A1994NL68500026 ER PT J AU LIU, AK PENG, CY SCHUMACHER, JD AF LIU, AK PENG, CY SCHUMACHER, JD TI WAVE-CURRENT INTERACTION STUDY IN THE GULF OF ALASKA FOR DETECTION OF EDDIES BY SYNTHETIC-APERTURE RADAR SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID REFRACTION; AGULHAS; SEA AB High resolution ERS-1 Synthetic Aperture Radar (SAR) images are used to detect a mesoscale eddy. Such features limit dispersal of pollock larvae and therefore likely influence recruitment of fish in the Gulf of Alaska. During high sea states and high winds, the direct surface signature of the eddy was not clearly visible, but the wave refraction in the eddy area was observed. The rays of the wave field are traced-out directly from the SAR image. The ray pattern gives information on the refraction pattern and on the relative variation of the wave energy along a ray through wave-current interaction. These observations are simulated by a ray-tracing model which incorporates a surface current field associated with the eddy. The numerical results of the model show that the waves are refracted and diverge in the eddy field with energy density decreasing. The model-data comparison for each ray shows the model predictions are in good agreement with the SAR data. C1 SCI SYST & APPLICAT INC,LANHAM,MD 20706. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP LIU, AK (reprint author), NASA,GODDARD SPACE FLIGHT CTR,OCEANS & ICE BRANCH,GREENBELT,MD 20771, USA. NR 31 TC 27 Z9 29 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 MAY 15 PY 1994 VL 99 IS C5 BP 10075 EP 10085 DI 10.1029/94JC00422 PG 11 WC Oceanography SC Oceanography GA NL930 UT WOS:A1994NL93000024 ER PT J AU THACKER, WC RAGHUNATH, R AF THACKER, WC RAGHUNATH, R TI THE RIGID LIDS CONTRIBUTION TO THE ILL-CONDITIONING OF OCEANIC INVERSE PROBLEMS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GENERAL-CIRCULATION MODEL; DATA ASSIMILATION AB Fitting oceanographic general circulation models to data is a difficult computational undertaking. This paper addresses difficulties stemming from the rigid lid approximation. Adjusting the barotropic stream function to achieve the fit, in effect, requires the solution of a hidden elliptical equation, the resolution-dependent difficulty of the elliptical problem manifest in the optimization problem. Adjusting the independent (subsuface) baroclinic velocity variables also contributes to the ill-conditioning of the least squares computation, but Lagrange multipliers can be used to adjust all baroclinic velocity variables (surface and subsurface) symmetrically. Similarly, Lagrange multipliers can be used to adjust the total velocity variables, thereby circumventing the use of barotropic stream function and baroclinic velocities; determining the multipliers at each optimization iteration requires the solution of an elliptical partial differential equation, the solution of which can be thought of as a preconditioning transformation. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,COOPERAT INST MARINE & ATMOSPHER STUDIES,MIAMI,FL 33149. RP THACKER, WC (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Thacker, Carlisle/I-3813-2013 OI Thacker, Carlisle/0000-0002-9285-8826 NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1994 VL 99 IS C5 BP 10131 EP 10141 DI 10.1029/94JC00053 PG 11 WC Oceanography SC Oceanography GA NL930 UT WOS:A1994NL93000028 ER PT J AU MANNING, JP OEY, LY PACKER, D VITALIANO, J FINNERAN, TW YOU, KW FROMM, S AF MANNING, JP OEY, LY PACKER, D VITALIANO, J FINNERAN, TW YOU, KW FROMM, S TI OBSERVATIONS OF BOTTOM CURRENTS AND ESTIMATES OF RESUSPENDED SEDIMENT TRANSPORT AT THE NEW-YORK-BIGHT 12-MILE DUMPSITE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID COMBINED WAVE; SHELF AB To document storm events that may induce a redistribution of sediment in the vicinity of the New York Bight 12-mile sewage sludge dumpsite, current meter moorings were deployed in water depths from 20 m (near the mouth of New York Harbor) to 53 m (within the Hudson Shelf Valley) from July 1986 through June 1989. Ten usable instrument records ranging from one month to one year in duration were obtained; eight of them near-bottom records. Seasonal and geographic variability of wind-induced flow were examined. The wind is most efficient in driving the subtidal currents in the 2-10 day frequency band during winter when the water column is well mixed and when the eastward component of the wind often induces and sustains an up-valley (northward) bottom flow. Maximum efficiency occurs for wind from 300-degrees (WNW) and at sites located within the Hudson Shelf Valley. A continental shelf bottom boundary layer model (Glenn and Grant, 1987) was used to estimate resuspended sediment transport. Model inputs include bottom currents (observed), orbital wave velocities (estimated), and sediment grain size (from the literature). Model output indicates that sediment resuspension at the current meter sites occurs approximately 5% of the time, primarily during winter months. The difference in along-valley flux between two moorings provides a rough estimate (6-month time series) of deposition and erosion. The net deposition (+.02 mm) was no greater than the deposition and erosion resulting from individual storms. A three-dimensional circulation model (You et al., 1991) is applied to increase the spatial resolution of the near-bottom current field (4 km grid) for a storm event in May of 1987. Given these velocities that vary in space and time, the redistribution of sediment was modeled for different surface wave conditions. Areas of deposition aligned with the Hudson Shelf Valley due to less wave-induced resuspension in deeper waters. Given all the uncertainties in the input variables (grain size, surface waves) and the simplistic assumptions made in modeling the deposition and erosion, it is still uncertain how much sludge is permanently removed from the area, but episodic redistribution of surficial sediment evidently occurs throughout the Inner New York Bight. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08542. STEVENS INST TECHNOL,DEPT CIVIL ENVIRONM & OCEAN ENGN,HOBOKEN,NJ 07030. NOAA,NATL MARINE FISHERIES SERV,JAMES J HOWARD LAB,HIGHLANDS,NJ 07732. RP MANNING, JP (reprint author), NOAA,NATL MARINE FISHERIES SERV,WOODS HOLE,MA 02543, USA. NR 25 TC 11 Z9 11 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 MAY 15 PY 1994 VL 99 IS C5 BP 10221 EP 10239 DI 10.1029/93JC03273 PG 19 WC Oceanography SC Oceanography GA NL930 UT WOS:A1994NL93000034 ER PT J AU SEAGER, R ZEBIAK, SE AF SEAGER, R ZEBIAK, SE TI CONVECTIVE INTERACTION WITH DYNAMICS IN A LINEAR PRIMITIVE EQUATION MODEL SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FREQUENCY INTRASEASONAL OSCILLATIONS; GENERAL-CIRCULATION MODEL; VERTICAL NORMAL-MODES; TROPICAL ATMOSPHERE; CUMULUS CONVECTION; JULIAN OSCILLATION; ADJUSTMENT SCHEME; SURFACE FLUXES; WATER-VAPOR; PARAMETERIZATION AB A new global atmosphere model purpose designed for climate studies is introduced. The model is solved in terms of the normal modes of the linearized primitive equations on a sphere, which allows use of long time steps without introducing computational instability or phase errors of the linear wave components. The model is tested by attempting to simulate the tropical intraseasonal oscillation using an idealized sea surface temperature distribution. Simple treatments of radiation and boundary-layer processes are used together with the much more complete Betts-Miller convection scheme. The Betts-Miller scheme maintains the atmosphere in a state of near neutrality to reversible saturated ascent. It is found that for different values of the surface evaporation time scale, either the evaporation-wind feedback mechanism postulated by Neelin et al. and Emmanuel or low-level convergence of moisture can create eastward propagating deep convective modes. In general, both mechanisms seem important, but it is the latter mechanism that provides phase speeds more in line with observations. Moisture convergence in this model works to erode the low-level equivalent potential temperature inversion that is ubiquitous in nonconvecting regions, thus triggering convection. In contrast to CISK models, changes in boundary-layer equivalent potential temperature are essential in this model to create propagating modes. The primary deficiency of the model is the tendency of the model to favor horizontal scales of convective disturbances that are much smaller than the zonal wavenumber one or two disturbances observed. This is related to the absence in the model of any pulsation of convection on an intraseasonal time scale over the warmest water regions that has been observed in satellite OLR data. Possible reasons for these differences are discussed. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,SEATTLE,WA 98195. RP SEAGER, R (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,NOAA,PROGRAM CLIMATE & GLOBAL CHANGE,PALISADES,NY 10964, USA. NR 48 TC 11 Z9 12 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 15 PY 1994 VL 51 IS 10 BP 1307 EP 1331 DI 10.1175/1520-0469(1994)051<1307:CIWDIA>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL467 UT WOS:A1994NL46700007 ER PT J AU KUMAR, A GALLAWA, RL AF KUMAR, A GALLAWA, RL TI BENDING-INDUCED LOSS IN DUAL-MODE RECTANGULAR WAVE-GUIDES SO OPTICS LETTERS LA English DT Article ID CORE OPTICAL FIBERS; 2-MODE FIBER; WAVE-GUIDES AB We examine how the bending-induced mode losses in a dual-mode rectangular-core waveguide vary with bend orientation. Bending about the minor axis [case (i)] and bending about the major axis [case (ii)] are considered. The second (LP11) mode is more lossy in case (i) than in case (ii), while the reverse is true for the first (LP01) mode. Further, in case (i) the LP11-mode loss is larger than the LP01-mode loss, but in case (ii) the LP01-mode loss is, surprisingly, larger than the LP11-mode loss. LP11-mode loss is consistent with the recent experimental results. This study should be useful in designing efficient elliptical-core fiber components such as LP11-mode strippers based on differential mode loss of the first two modes. RP NIST, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 EI 1539-4794 J9 OPT LETT JI Opt. Lett. PD MAY 15 PY 1994 VL 19 IS 10 BP 707 EP 709 DI 10.1364/OL.19.000707 PG 3 WC Optics SC Optics GA NK819 UT WOS:A1994NK81900009 PM 19844419 ER PT J AU PIERCE, DT STROSCIO, JA UNGURIS, J CELOTTA, RJ AF PIERCE, DT STROSCIO, JA UNGURIS, J CELOTTA, RJ TI INFLUENCE OF CR GROWTH ON EXCHANGE COUPLING IN FE/CR/FE(100) SO PHYSICAL REVIEW B LA English DT Article ID LAYERED MAGNETIC-STRUCTURES; INTERLAYER EXCHANGE; MAGNETORESISTANCE; MULTILAYERS; MECHANISM; MICROSCOPY; DIFFUSION; SI(001); ENERGY; IRON AB Scanning electron microscopy with polarization-analysis (SEMPA) measurements of the dependence of the oscillations of the exchange coupling in Fe/Cr/Fe(100) structures on the Cr growth temperature are correlated with the thickness fluctuations in Cr films measured by scanning tunneling microscopy (STM) at similar growth temperatures. Layer-by-layer growth was observed by STM for Cr deposition on very flat Fe(100) whiskers at deposition temperatures greater-than-or-equal-to 300-degrees-C. The SEMPA measurements of the magnetization of the Fe overlayer as a function of Cr spacer-layer thickness at this temperature could be simulated well by oscillatory coupling with periods 2.105+/-0.005d and 12+/-1d, where d is the layer spacing. Rougher Cr growth, limited by diffusion kinetics, occurs at lower growth temperatures giving a distribution of thicknesses in the growth front as determined by STM. We modeled the Fe magnetization for lower-temperature Cr growth by assuming that the exchange coupling at each discrete Cr thickness is the same as found for layer-by-layer growth. The total coupling at each average Cr spacer-layer thickness was determined by adding the weighted contribution to the coupling from each Cr layer thickness contributing to the average thickness. Thus, by taking into account the thickness fluctuations in the Cr spacer layer as determined by STM, very good agreement was obtained between the model and the SEMPA measurement of the Fe overlayer magnetization for Cr growth at lower temperatures without including other consequences of roughness at the interface, such as the breakdown of translational invariance. Important characteristic length scales and the role of biquadratic coupling in the SEMPA measurements are addressed. RP PIERCE, DT (reprint author), NATL INST STAND & TECHNOL, ELECTRON PHYS GRP, GAITHERSBURG, MD 20899 USA. RI Unguris, John/J-3989-2014 NR 32 TC 79 Z9 79 U1 0 U2 6 PU AMER 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 MAY 15 PY 1994 VL 49 IS 20 BP 14564 EP 14572 DI 10.1103/PhysRevB.49.14564 PG 9 WC Physics, Condensed Matter SC Physics GA NR423 UT WOS:A1994NR42300054 ER PT J AU YSERN, X FIELDS, BA BHAT, TN GOLDBAUM, FA DALLACQUA, W SCHWARZ, FP POLJAK, RJ MARIUZZA, BA AF YSERN, X FIELDS, BA BHAT, TN GOLDBAUM, FA DALLACQUA, W SCHWARZ, FP POLJAK, RJ MARIUZZA, BA TI SOLVENT REARRANGEMENT IN AN ANTIGEN-ANTIBODY INTERFACE INTRODUCED BY SITE-DIRECTED MUTAGENESIS OF THE ANTIBODY COMBINING SITE SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Note DE 3-DIMENSIONAL STRUCTURE; SITE-DIRECTED MUTAGENESIS; ANTIGEN-ANTIBODY REACTION; ENTHALPY-ENTROPY; HYDROPHOBIC EFFECT ID BINDING C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,ROCKVILLE,MD 20850. NCI,FREDERICK CANC RES & DEV CTR,CTR BIOMED SUPERCOMP,STRUCT BIOCHEM PROGRAM,FREDERICK,MD 21202. RP YSERN, X (reprint author), US FDA,CTR DRUG EVALUAT & RES,ROCKVILLE,MD 20857, USA. NR 17 TC 58 Z9 58 U1 0 U2 2 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 MAY 13 PY 1994 VL 238 IS 4 BP 496 EP 500 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA NM066 UT WOS:A1994NM06600002 PM 8176740 ER PT J AU MATSON, M STEPHENS, G AF MATSON, M STEPHENS, G TI UNUSUAL ARSON FIRES IN THE UNITED-STATES SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Note RP MATSON, M (reprint author), NOAA,WASHINGTON,DC 20233, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAY 10 PY 1994 VL 15 IS 7 BP 1363 EP 1364 PG 2 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA NQ127 UT WOS:A1994NQ12700001 ER PT J AU WAGNER, CA KLOKOCNIK, J AF WAGNER, CA KLOKOCNIK, J TI ACCURACY OF THE GEM-T2 GEOPOTENTIAL FROM GEOSAT AND ERS-1 CROSSOVER ALTIMETRY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GRAVITY MODEL IMPROVEMENT; SATELLITE ALTIMETRY; ORBIT; SEASAT; ERRORS; TIDES AB Extensive analyses of altimetrically determined sea height differences at crossovers have been used to assess the accuracy of the GEM-T2 geopotential. The orbits used were determined with GEM-T2 for Geosat in its 17-day Exact Repeat Mission (ERM) in 1986-1989 and ERS 1 in both its 3-day ERM in 1991-1992 and its 35-day ERM in 1992. The data examined are completely independent of the data used in GEM-T2's development though GEM-T2 had considerable use of Doppler tracking information on Geosat. The test of the radial accuracy of the ERS 1 orbit (98.5-degrees inclination) is especially significant because it is not ''close'' to any other orbit well represented in GEM-T2. The assessment consists of a comparison of observed mean height differences at thousands of distinct geographic locations with error projections from the GEM-T2 covariance matrix which was estimated from other data sources. This first comprehensive, independent test of the purely radial accuracy of an orbit-geopotential model clearly shows that the covariant predictions for GEM-T2 are broadly reliable for this purpose. Thus, the agreement of crossover predictions and observations suggests that the total radial errors for these ERMs, due only to GEM-T2 (but excluding the effects of initial state error) are about 23 cm for Geosat and 115 cm (rms) for ERS 1. However, there is little detailed agreement of measurements and predictions for ERS 1 and only partial agreement in detail for Geosat. Our 30,000 mean crossover discrepancies for Geosat (derived from ERM cycles 1-44) are also shown to reduce substantially the crossover height differences in cycles 45-61, almost exactly as predicted if these are the true GEM-T2 errors for this orbit. C1 ACAD SCI CZECH REPUBL, INST ASTRON, CS-25165 ONDREJOV OBSERV, CZECHOSLOVAKIA. RP WAGNER, CA (reprint author), NOAA, NATL OCEAN SERV, OES-11, 1305 E W HIGHWAY, SILVER SPRING, MD 20910 USA. RI Klokocnik, Jaroslav/G-9025-2014 NR 54 TC 17 Z9 17 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1994 VL 99 IS B5 BP 9179 EP 9201 DI 10.1029/93JB03109 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NL920 UT WOS:A1994NL92000012 ER PT J AU BUTTERFIELD, DA MCDUFF, RE MOTTL, MJ LILLEY, MD LUPTON, JE MASSOTH, GJ AF BUTTERFIELD, DA MCDUFF, RE MOTTL, MJ LILLEY, MD LUPTON, JE MASSOTH, GJ TI GRADIENTS IN THE COMPOSITION OF HYDROTHERMAL FLUIDS FROM THE ENDEAVOR SEGMENT VENT FIELD - PHASE-SEPARATION AND BRINE LOSS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DE-FUCA RIDGE; EAST PACIFIC RISE; SEAFLOOR GEOTHERMAL SYSTEMS; HOT-SPRING FLUIDS; MID-OCEAN RIDGES; SUPERCRITICAL REGION; BASALT ALTERATION; AXIAL VOLCANO; JUAN; CONSTRAINTS AB Hydrothermal fluid samples collected in 1984, 1987, and 1988 from a large vent field near 47-degrees-57'N on the Endeavour segment of the Juan de Fuca Ridge (JFR) have been analyzed for major and minor elements and gases. There are of the order of 100 individual smoker vents on approximately 10 large sulfide structures, which are localized along faults and fault intersections across the vent field. Each sulfide structure has a characteristic fluid composition, which varies very little from one vent orifice to the next, or from year to year, on a given structure. However, there are large gradients in fluid composition across the vent field, with endmember chlorinity increasing from approximately 255 mmol/kg in the SW to 505 mmol/kg in the NE. End-member concentrations of major elements are well correlated with chlorinity, and endmember volatile concentrations in the lowest chlorinity fluids are approximately twice as high as in the highest chlorinity fluids. The gradients in composition across the vent field and measured vent fluid temperatures >400-degrees-C are consistent with supercritical phase separation and loss of brine phase below the seafloor. The factor-of-2 variation in CO2 (and H2S) is larger than expected for loss of a very high-chlorinity brine. Concentrations of iron and manganese are not positively correlated with chlorinity, suggesting that temperature and pH are more important in controlling metal solubility. Elevated ammonia and bromide/chloride ratios indicate that there has been subseafloor interaction between the hydrothermal fluids and organic matter, and high boron concentrations point to a sedimentary source. C1 NOAA, HATFIELD MARINE SCI CTR, PACIFIC MARINE ENVIRONM LAB, NEWPORT, OR 97365 USA. UNIV HAWAII, DEPT OCEANOG, HONOLULU, HI 96822 USA. UNIV WASHINGTON, SCH OCEANOG, SEATTLE, WA 98195 USA. UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEAN, SEATTLE, WA 98195 USA. RP BUTTERFIELD, DA (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, BLDG 3, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Butterfield, David/H-3815-2016 OI Butterfield, David/0000-0002-1595-9279 NR 60 TC 178 Z9 182 U1 1 U2 35 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1994 VL 99 IS B5 BP 9561 EP 9583 DI 10.1029/93JB03132 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NL920 UT WOS:A1994NL92000038 ER PT J AU VANDERHART, DL MANLEY, RSJ BARNES, JD AF VANDERHART, DL MANLEY, RSJ BARNES, JD TI PROTON SPIN-DIFFUSION STUDIES OF POLYMER BLENDS HAVING MODEST MONOMER SIZE .2. BLENDS OF CELLULOSE WITH EITHER POLY(ACRYLONITRILE) OR POLY(4-VINYLPYRIDINE) SO MACROMOLECULES LA English DT Article ID N,N-DIMETHYLACETAMIDE LITHIUM-CHLORIDE; MULTIPLE PULSE NMR; MAGIC-ANGLE; RESOLUTION; SOLIDS AB Blends of cellulose (CELL) with either poly(4-vinylpyridine) (P4VPy) or poly(acrylonitrile) (PAN) have been examined by solid-state proton NMR. Multiple-pulse techniques combined with the phenomenology of spin diffusion allow one to obtain information about average domain size along the thinnest dimension of the domains. In addition, one can obtain information about the stoichiometry of the phases. CELL/P4VPy blends were examined over a composition range from 30 to 70% CELL; CELL/PAN blends spanned a composition range from 32 to 88% CELL. It was found that average overall repeat distances for the CELL/P4VPy blends were in the 8-12-nm range, while for the CELL/PAN blends the range was ca. 16-24 nm. As a function of overall composition, there were no sudden changes in dimensions or, by implication, in miscibility. As to stoichiometry, very little mixing took place; typically <5 % of polymer A would be found in a polymer B-rich phase. Given this weak mixing, it is surmised that the thermodynamics of mixing are quite unfavorable for these pairs; i.e., the kinetics of phase separation are important in defining the morphology. The importance of kinetics is also manifested in a rather wide dispersion of domain size in the CELL/P4VPy blends; dispersion is smaller in the CELL/PAN blends. Small-angle X-ray scattering was also applied to a representative sample of each blend. The SAXS results corroborated the NMR results regarding domain size and size dispersion. Finally, the fact that dynamic mechanical analysis (at 11 Hz) had previously been reported on these blends enabled us to comment on the critical domain size below which the molecular motion (or T(g)) for PAN would be influenced by the rigidity of the surrounding CELL phase. That critical size was found to be in the 10-13-nm range. C1 MCGILL UNIV,PULP & PAPER RES CTR,MONTREAL H3A 2A7,QUEBEC,CANADA. MCGILL UNIV,DEPT CHEM,MONTREAL H3A 2A7,QUEBEC,CANADA. RP VANDERHART, DL (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 24 TC 26 Z9 26 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 MAY 9 PY 1994 VL 27 IS 10 BP 2826 EP 2836 DI 10.1021/ma00088a025 PG 11 WC Polymer Science SC Polymer Science GA NL250 UT WOS:A1994NL25000025 ER PT J AU VANDERHART, DL AF VANDERHART, DL TI PROTON SPIN-DIFFUSION STUDIES OF POLYMER BLENDS HAVING MODEST MONOMER SIZE .1. POLYSTYRENE POLY(XYLYLENE ETHER), A MISCIBLE BLEND SO MACROMOLECULES LA English DT Article ID MULTIPLE PULSE NMR; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); MECHANICAL-PROPERTIES; H-1-NMR; SOLIDS AB Proton spin diffusion experiments, utilizing multiple-pulse methods, have been conducted on three samples of a 50/50 blend of polystyrene (PS) and poly(xylylene ether) (PXE) as well as on the PS and PXE homopolymers. The PS/PXE blend is considered miscible on a molecular scale; this was verified by demonstrating the strength of the early-time spin diffusion between the PS and PXE protons. An attempt was made to estimate the average number of dissimilar monomers surrounding a repeat unit of a given type, and for this discussion a model of a simple cubic lattice was adopted. This exercise involved several other assumptions and was semiquantitative. It was judged that, allowing for chain continuity, the number of dissimilar nearest neighbors surrounding any given repeat unit is close to or greater than that dictated by the relative abundances of the respective monomer units. A second motivation for this study is that it provides a base line for other spin diffusion studies on glassy, phase-separated blends of similar monomer size. In the general case, spin diffusion data from such blends involves three kinds of spin equilibration, namely, homopolymer, intraphase heteropolymer (assuming phases of mixed composition), and interphase heteropolymer, where only the latter process is considered interesting. The PS/PXE data and the homopolymer data relate to the appropriate modeling of the first two kinds of equilibration. Homopolymer equilibration is seen to be better than 99 % complete after 1 ms of spin diffusion, while intraphase heteropolymer equilibration has an initial fast component followed by a rather long tail, extending past 10 ms of spin diffusion, owing mostly to the statistics of mixing or the fluctuations in average composition over small volumes. RP VANDERHART, DL (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 23 TC 36 Z9 36 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 MAY 9 PY 1994 VL 27 IS 10 BP 2837 EP 2845 DI 10.1021/ma00088a026 PG 9 WC Polymer Science SC Polymer Science GA NL250 UT WOS:A1994NL25000026 ER PT J AU CIRAC, JI LEWENSTEIN, M ZOLLER, P AF CIRAC, JI LEWENSTEIN, M ZOLLER, P TI QUANTUM STATISTICS OF A LASER COOLED IDEAL-GAS SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLARIZED ATOMIC-HYDROGEN; PHOTON RECOIL; BOSE; MOTION; FIELD AB We study the dynamics of a system of bosonic or fermionic atoms in a microscopic trap undergoing laser cooling. We show that the stationary state can be described by a Bose-Einstein or Fermi-Dirac distribution, respectively, Fluorescence from the system reflects quantum statistical properties. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP CIRAC, JI (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Zoller, Peter/O-1639-2014; Lewenstein, Maciej/I-1337-2014 OI Zoller, Peter/0000-0003-4014-1505; Lewenstein, Maciej/0000-0002-0210-7800 NR 33 TC 43 Z9 43 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 9 PY 1994 VL 72 IS 19 BP 2977 EP 2980 DI 10.1103/PhysRevLett.72.2977 PG 4 WC Physics, Multidisciplinary SC Physics GA NK457 UT WOS:A1994NK45700001 ER PT J AU ZHANG, H GALLAGHER, PD SATIJA, SK LINDSTROM, RM PAUL, RL RUSSELL, TP LAMBOOY, P KRAMER, EJ AF ZHANG, H GALLAGHER, PD SATIJA, SK LINDSTROM, RM PAUL, RL RUSSELL, TP LAMBOOY, P KRAMER, EJ TI GRAZING-INCIDENCE PROMPT GAMMA EMISSIONS AND RESONANCE-ENHANCED NEUTRON STANDING WAVES IN A THIN-FILM SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-FLUORESCENCE; MEMBRANES AB We report simultaneous measurements of neutron-capture prompt gamma emissions as well as neutron reflectivity on a polymer film with an embedded Gd layer. Enhanced gamma-ray signals and reduced neutron reflectivity were observed when the neutron standing waves were resonantly amplified in the film. Fitting of both the gamma-ray and reflectivity data is of significant aid in uniquely characterizing the depth profile of the polymer film as well as locating the Gd layer. C1 NATL INST SCI & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. IBM CORP, ALMADEN RES CTR, SAN JOSE, CA 95120 USA. UNIV MARYLAND, DEPT MAT & NUCL ENGN, COLL PK, MD 20742 USA. CORNELL UNIV, DEPT MAT SCI & ENGN, ITHACA, NY 14853 USA. CORNELL UNIV, CTR MAT SCI, ITHACA, NY 14853 USA. NATL INST SCI & TECHN CREAT, DIV INORGAN ANALYT RES, GAITHERSBURG, MD 20899 USA. RP ZHANG, H (reprint author), NATL INST SCI & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. NR 11 TC 25 Z9 26 U1 2 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 9 PY 1994 VL 72 IS 19 BP 3044 EP 3047 DI 10.1103/PhysRevLett.72.3044 PG 4 WC Physics, Multidisciplinary SC Physics GA NK457 UT WOS:A1994NK45700018 ER PT J AU POWELL, CJ JABLONSKI, A TANUMA, S PENN, DR AF POWELL, CJ JABLONSKI, A TANUMA, S PENN, DR TI EFFECTS OF ELASTIC AND INELASTIC ELECTRON-SCATTERING ON QUANTITATIVE SURFACE-ANALYSES BY AES AND XPS SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 5th International Conference on Electron Spectroscopy (ICES 5) CY JUL 25-AUG 01, 1993 CL INST THEORET PHYS, KIEV, UKRAINE SP ACAD SCI UKRAINE HO INST THEORET PHYS ID MEAN FREE PATHS; X-RAY PHOTOELECTRON; LOW-ENERGY ELECTRONS; TOUGAARD BACKGROUND SUBTRACTION; LEAST-SQUARES ANALYSIS; AUGER-ELECTRON; ATTENUATION LENGTHS; RELATIVE INTENSITIES; ANGULAR-DISTRIBUTION; ANALYTICAL EXPRESSION AB A review is given that describes the complications due to elastic and inelastic electron scattering in quantitative surface analyses by Auger-electron spectroscopy and x-ray photoelectron spectroscopy. Four principal topics are addressed. First, the simple formulae for surface analyses are based on a model that ignores elastic scattering. Recent work assessing the effects of elastic scattering is summarized which shows that the simple formulae are valid in certain analytical situations but with an appropriate choice of the parameter describing inelastic scattering. Second, we review measurements of effective attenuation lengths and point out many sources of significant systematic error in these measurements. Third, we describe recent calculations of inelastic mean free paths (IMFPs) in over fifty materials that have been utilized to develop a predictive IMFP formula. Finally, we discuss the complicating effects of inelastic scattering on reliable measurements of AES and XPS intensities. C1 POLISH ACAD SCI,INST PHYS CHEM,PL-01224 WARSAW,POLAND. NIPPON MIN CO LTD,ANAL RES CTR,TODA,SAITAMA 335,JAPAN. RP POWELL, CJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Tanuma, Shigeo/H-2681-2011 NR 97 TC 49 Z9 49 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY 6 PY 1994 VL 68 BP 605 EP 616 DI 10.1016/0368-2048(94)80023-5 PG 12 WC Spectroscopy SC Spectroscopy GA NP538 UT WOS:A1994NP53800069 ER PT J AU POZSGAY, V COXON, B AF POZSGAY, V COXON, B TI SYNTHESIS AND 2-DIMENSIONAL NUCLEAR-MAGNETIC-RESONANCE ANALYSIS OF A TETRA-SACCHARIDE AND A HEXASACCHARIDE FRAGMENT OF THE O-SPECIFIC POLYSACCHARIDE OF SHIGELLA-DYSENTERIAE TYPE-1 SO CARBOHYDRATE RESEARCH LA English DT Article ID B STREPTOCOCCAL POLYSACCHARIDES; TRI-SACCHARIDE; STEREOSELECTIVE SYNTHESIS; STRUCTURAL-ANALYSIS; COMMON ANTIGEN; DI-SACCHARIDE; ACETYL GROUPS; OLIGOSACCHARIDES; TRISACCHARIDE; SPECTROSCOPY AB The synthesis of the tetra- and hexa-saccharide methyl glycosides alpha-D-Gal p-(1 --> 3)-alpha-D-Glc p NAc-(1 --> 3)-alpha-L-Rha p-(1 --> 3)-alpha-L-Rha p-OMe (1), and alpha-L-Rha p-(1 --> 3)-alpha-L-Rha p-(1 --> 2)-alpha-D-Gal p-(1 --> 3)-alpha-D-Glc p NAc-(1 --> 3)-alpha-L-Rha p-(1 --> 3)-alpha-L-Rha p-OMe (3) is described, which represent various epitopes of the O-specific polysaccharide of Shigella dysenteriae type 1. The following monosaccharide intermediates were used: 1,3-di-O-acetyl-2- O-benzoyl-4-O-benzyl-alpha-L-rhamnopyranose (6 alpha), methyl 2,4-di-O-benzyl-alpha-L-rhamnopyranoside (7), methyl 2,4-di-O-benzoyl-1-thio-alpha-L-rhamnopyranoside (8), 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl bromide (9), methyl 3,4,6-tri-O-benzyl-2-O-(4-methoxybenzyl)-1-thio-beta-D-galactopyranoside (13), methyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-galactopyranoside (16), and 2-azido-4,6-O-benzylidene-3-O-bromoacetyl-2-deoxy-beta-D-glucopyranosyl chloride (19). A detailed analysis of the H-1 and C-13 NMR spectra of oligosaccharides I and 3 confirmed that the hexasaccharide 3 better approaches the conformation of the native polysaccharide, than either 1 or the homologous pentasaccharide 41. C1 NIDDKD,MED CHEM LAB,BETHESDA,MD 20892. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. RP POZSGAY, V (reprint author), NICHHD,DEV & MOLEC IMMUN LAB,BLDG 6,RM 145,BETHESDA,MD 20892, USA. NR 47 TC 38 Z9 38 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD MAY 5 PY 1994 VL 257 IS 2 BP 189 EP 215 DI 10.1016/0008-6215(94)80035-9 PG 27 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA NL078 UT WOS:A1994NL07800003 PM 8013005 ER PT J AU WALHOUT, M WITTE, A ROLSTON, SL AF WALHOUT, M WITTE, A ROLSTON, SL TI PRECISION-MEASUREMENT OF THE METASTABLE 6S [3/2]2 LIFETIME IN XENON SO PHYSICAL REVIEW LETTERS LA English DT Article ID STATES; ATOMS AB Using a magneto-optical trap to isolate an isotopically pure sample of xenon, we determine the metastable 6s [3/2]2 state lifetime by measuring the rate of VUV emission due to magnetic quadrupole decay. We find lifetimes of 42.9(9) s and 42.4(13) s for Xe-132 and Xe-136, respectively (1 sigma uncertainties). These values are less than half the theoretical predictions. We also find that nuclear-spin-induced decay produces a much shorter metastable lifetime in Xe-129. C1 UNIV MARYLAND,DEPT PHYS,COLL PK,MD 20742. RP WALHOUT, M (reprint author), NATL INST STAND & TECHNOL,BLDG 221,ROOM A167,GAITHERSBURG,MD 20899, USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 11 TC 38 Z9 39 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 MAY 2 PY 1994 VL 72 IS 18 BP 2843 EP 2846 DI 10.1103/PhysRevLett.72.2843 PG 4 WC Physics, Multidisciplinary SC Physics GA NJ297 UT WOS:A1994NJ29700006 ER PT J AU LAMBOOY, P RUSSELL, TP KELLOGG, GJ MAYES, AM GALLAGHER, PD SATIJA, SK AF LAMBOOY, P RUSSELL, TP KELLOGG, GJ MAYES, AM GALLAGHER, PD SATIJA, SK TI OBSERVED FRUSTRATION IN CONFINED BLOCK-COPOLYMERS SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN-FILMS; NEUTRON REFLECTIVITY; DIBLOCK COPOLYMERS AB Symmetric, diblock copolymers confined between two solid surfaces were studied by neutron reflectivity. A multilayered morphology with an integral number of layers oriented parallel to the solid interfaces was found in all cases. The period of the confined multilayers deviated from the bulk period in a cyclic manner as a function of the confined film thickness. A first-order transition occurred between the expanded and contracted states of the copolymer chains. The data suggest that the deviation of the period from the bulk value decreases with increasing separation distance. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. NATL INST STAND & TECHNOL,DIV REACTOR & RADIAT,GAITHERSBURG,MD 20878. RP LAMBOOY, P (reprint author), IBM CORP,DIV RES,ALMADEN RES CTR,650 HARRY RD,SAN JOSE,CA 95120, USA. NR 18 TC 234 Z9 236 U1 3 U2 36 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 2 PY 1994 VL 72 IS 18 BP 2899 EP 2902 DI 10.1103/PhysRevLett.72.2899 PG 4 WC Physics, Multidisciplinary SC Physics GA NJ297 UT WOS:A1994NJ29700020 ER PT J AU VARANASI, U STEIN, JE TILBURY, KL MEADOR, JP SLOAN, CA CLARK, RC CHAN, SL AF VARANASI, U STEIN, JE TILBURY, KL MEADOR, JP SLOAN, CA CLARK, RC CHAN, SL TI CHEMICAL CONTAMINANTS IN GRAY WHALES (ESCHRICHTIUS-ROBUSTUS) STRANDED ALONG THE WEST-COAST OF NORTH-AMERICA SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE GRAY WHALE; MARINE MAMMAL; CHLORINATED HYDROCARBONS; METALS ID SOLE PAROPHRYS-VETULUS; PUGET-SOUND; AROMATIC-HYDROCARBONS; HEAVY-METALS; WASHINGTON; ORGANOCHLORINES; LESIONS; TISSUES; ESTUARY; URBAN AB The concentrations of selected chlorinated hydrocarbons (e.g. PCBs, DDTs, DDEs, chlordanes) and essential (e.g. zinc, selenium, copper) and toxic (e.g. mercury, lead, arsenic) elements were measured in tissues and stomach contents from 22 gray whales (Eschrichtius robustus) stranded between 1988 and 1991 at sites from the relatively pristine areas of Kodiak Island, AK, to more urbanized areas in Puget Sound, WA, and San Francisco Bay, CA..The majority of animals were stranded at sites on the Washington outer coast and in Puget Sound. The gray whale has the unique feeding strategy among Mysticeti of filtering sediments to feed on benthic (bottom dwelling) invertebrates. Thus, the wide geographical distribution of the stranded whales allowed (1) an initial assessment of whether concentrations of chemical contaminants in these whales exhibited region specific differences and (2) whether toxic chemicals that accumulate in sediments may have contributed to the mortality and stranding of gray whales near the more polluted urban areas. Analyses for chlorinated hydrocarbons in blubber from 22 animals showed no apparent significant differences among stranding sites. The concentrations of SIGMAPCBs and SIGMADDEs in blubber, for example, ranged from 120 to 10000 and 9 to 2100 p.p.b. (ng/g) wet weight, respectively. Additionally, analyses of chlorinated hydrocarbons and selected elements in liver (n = 10) also showed no apparent significant differences between whales stranded in Puget Sound and whales stranded at more pristine sites (Alaska, Washington outer coast and Strait of Juan de Fuca and Strait of Georgia). For example, the concentrations of SIGMAPCBs and SIGMADDEs in liver ranged from 79 to 1600 and 7 to 280 p.p.b., respectively, and the concentrations of the toxic elements, mercury and lead ranged from 9 to 120 and 20 to 270 p.p.b., respectively. Analyses of stomach contents revealed low concentrations of chlorinated hydrocarbons, but high concentrations (wet weight) of aluminum (1 700 000 +/- 450 000 p.p.b.), iron (320 000 +/- 250 000 p.p.b.), manganese (23 000 +/- 15 000 p.p.b.), and chromium (3400 +/- 1300 p.p.b.), but no significant differences were observed between whales stranded in Puget Sound compared to whales stranded at the more pristine sites. The relative proportions of these elements in stomach contents of stranded whales were similar to the relative proportions in sediments, which is consistent with a geological source of these elements from the ingestion of sediment during feeding. Thus, overall, the concentrations of anthropogenic chemicals in stranded gray whales showed little relation to the levels of chemical contaminants at the stranding sites. Further, the results showed that the concentrations of potentially toxic chemicals in tissues were relatively low when compared with the concentrations in tissues of marine mammals feeding on higher trophic level species, such as fish. The lack of data from apparently healthy gray whales, however, limits the assessment of whether the levels of anthropogenic contaminants found in tissues may have deleterious effects on the health of gray whales. RP VARANASI, U (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 49 TC 30 Z9 32 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAY 2 PY 1994 VL 145 IS 1-2 BP 29 EP 53 DI 10.1016/0048-9697(94)90296-8 PG 25 WC Environmental Sciences SC Environmental Sciences & Ecology GA NJ799 UT WOS:A1994NJ79900004 PM 8016628 ER PT J AU SPAL, RD AF SPAL, RD TI THE EFFECT OF A CRYSTAL MONOCHROMATOR ON THE LOCAL ANGULAR DIVERGENCE OF AN X-RAY-BEAM SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID SYNCHROTRON RADIATION AB The performance of an X-ray optical system often depends critically on the local angular divergence of the X-ray beam. For example, in systems for radiography, tomography and diffraction topography, the angular divergence of the incident beam at a point in the sample determines the limiting spatial resolution. In this paper, formulas are derived for the local divergence in the diffracted beam of the non-dispersive asymmetric reflection double-flat-crystal monochromator, illuminated by synchrotron or characteristic radiation. The formulas are analyzed to determine the general behavior of the local divergence as a function of the asymmetry factors of the crystal reflections. For synchrotron radiation. one surprising conclusion is that the local divergence of the magnifying monochromator is always greater than that of the symmetric monochromator, significantly so for even moderate magnification factors. This result, which contradicts a claim in the literature, is attributed to a prismatic property of asymmetric reflection that has not previously been identified. RP SPAL, RD (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 4 TC 2 Z9 2 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1994 VL 50 BP 295 EP 301 DI 10.1107/S0108767393009286 PN 3 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA NM316 UT WOS:A1994NM31600004 ER PT J AU MA, Q POMPE, W FRENCH, JD CLARKE, DR AF MA, Q POMPE, W FRENCH, JD CLARKE, DR TI RESIDUAL-STRESSES IN AL2O3-ZRO2 COMPOSITES - A TEST OF STOCHASTIC STRESS MODELS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article AB In cooling sintered composites of Al2O3-ZrO2 from their fabrication temperature residual stresses are created as a result of both the difference in thermal expansion between the two phases and the crystallographically anisotropic thermal expansion of the Al2O3 Phase. In this work the first and second moments of the residual stress distribution have been measured as a function of volume fraction of zirconia from 0.01 to 0.90. The measurement technique used is piezo-spectroscopy based on the optical fluorescence from Cr3+ dopants in the alumina phase. For zirconia volume fractions up to 0.35 the average stress accurately fits the predictions given by the upper Hashin bound and this fit provides a value of the average thermal strain in the composites. Using this value, the effective medium approximation produces an excellent description of the average stress over the entire volume fraction. It is also shown that the fluorescence broadening due to stress fluctuations lies close to the predicted upper and lower Hashin bounds modified by the restrictions imposed by the principle of maximum entropy. The measured moments and those predicted by stochastic stress analysis compare well suggesting that the stochastic analysis provides a reliable method of calculating residual stress in composites. C1 TECH UNIV DRESDEN, DEPT MAT SCI, O-8027 DRESDEN, GERMANY. NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP MA, Q (reprint author), UNIV CALIF SANTA BARBARA, DEPT MAT, SANTA BARBARA, CA 93106 USA. RI Clarke, David/D-2616-2009; Albe, Karsten/F-1139-2011 NR 15 TC 72 Z9 72 U1 3 U2 9 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 MAY PY 1994 VL 42 IS 5 BP 1673 EP 1681 DI 10.1016/0956-7151(94)90377-8 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NC237 UT WOS:A1994NC23700018 ER PT J AU LAWN, BR PADTURE, NP GUIBERTEAU, F CAI, H AF LAWN, BR PADTURE, NP GUIBERTEAU, F CAI, H TI A MODEL FOR MICROPACK INITIATION AND PROPAGATION BENEATH HERTZIAN CONTACTS IN POLYCRYSTALLINE CERAMICS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID SUBTHRESHOLD INDENTATION FLAWS; FRACTURE-MECHANICS MODEL; SODA-LIME GLASS; BRITTLE SOLIDS; CRACK-RESISTANCE; GRAIN-SIZE; ALUMINA; DEFORMATION; FATIGUE; STRESS AB A fracture mechanics model of damage evolution within Hertzian stress fields in heterogeneous brittle ceramics is developed. Discrete microcracks generate from shear faults associated with the heterogeneous ceramic microstructure; e.g. in polycrystalline alumina, they initiate at the ends of intragrain twin lamellae and extend along intergrain boundaries. Unlike the well-defined classical cone fracture that occurs in the weakly tensile region outside the surface contact in homogeneous brittle solids, the fault-microcrack damage in polycrystalline ceramics is distributed within a subsurface shear-compression zone below the contact. The shear faults are modelled as sliding interfaces with friction, in the manner of established rock mechanics descriptions but with provision for critical nucleation and matrix restraining stresses. This allows for constrained microcrack pop-in during the loading half-cycle. Ensuing stable microcrack extension is then analyzed in terms of a K-field formulation. For simplicity, only mode I extension is considered specifically here, although provision exists for including mode II. The compressive stresses in the subsurface field constrain microcrack growth during the loading half-cycle, such that enhanced extension occurs during unloading. Data from damage observations in alumina ceramics are used to illustrate the theoretical predictions. Microstructural scaling is a vital element in the microcrack description: initiation is unstable only above a critical grain size, and extension increases as the grain size increases. Internal residual stresses also play an important role in determining the extent of microcrack damage. Implications of the results in the practical context of wear and fatigue properties are discussed. C1 NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Padture, Nitin/A-9746-2009 OI Padture, Nitin/0000-0001-6622-8559 NR 56 TC 62 Z9 62 U1 4 U2 16 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 MAY PY 1994 VL 42 IS 5 BP 1683 EP 1693 DI 10.1016/0956-7151(94)90378-6 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NC237 UT WOS:A1994NC23700019 ER PT J AU OHNO, Y AF OHNO, Y TI INTEGRATING SPHERE SIMULATION - APPLICATION TO TOTAL FLUX SCALE REALIZATION SO APPLIED OPTICS LA English DT Article DE CALIBRATION; COMPUTER SIMULATION; INTEGRATING SPHERE; LUMEN; LUMINOUS FLUX; PHOTOMETER; PHOTOMETRY; RADIANT FLUX; RAY TRACING; SCALE; STANDARDS; TOTAL FLUX AB A method is proposed for realizing the total flux scale of light sources by use of an integrating sphere with an opening to introduce a known amount of flux from a luminous intensity standard or a spectral irradiance standard lamp placed outside the sphere. Computer simulations were made on several models of an integrating sphere, designed to compare the total flux of a test lamp inside the sphere with the flux introduced from an external source. I describe the theory and algorithm of the simulation, present the results of the simulation for varying conditions of sphere geometry such as size and location of the baffles, internal source, and wall reflectance, and predict that one of the models has sufficient accuracy to calibrate lamps for total flux. RP OHNO, Y (reprint author), NATL INST STAND & TECHNOL, DIV RADIOMETR PHYS, ROOM A305, BLDG 220, GAITHERSBURG, MD 20899 USA. NR 16 TC 22 Z9 22 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 1 PY 1994 VL 33 IS 13 BP 2637 EP 2647 PG 11 WC Optics SC Optics GA NJ771 UT WOS:A1994NJ77100029 PM 20885619 ER PT J AU PETERSON, D FREIMAN, SW AF PETERSON, D FREIMAN, SW TI SUMMARY OF NIST DOE WORKSHOP - PHASE-DIAGRAMS FOR HIGH T(C) SUPERCONDUCTORS SO APPLIED SUPERCONDUCTIVITY LA English DT Article ID CRYSTAL-CHEMISTRY; EQUILIBRIA; YBA2CU3O6+X; SYSTEMS AB On June 2-4, 1993, a workshop on Phase Diagrams for High T(c) Superconductors was held at the Picacho Plaza Hotel Hotel in Santa Fe, New Mexico. The purpose of this workshop was to allow workers in this field to present the most up-to-date picture of phase diagrams and related data in chemical systems important for the processing and application of high T(c) superconductors. In addition to phase equilibria information, a number of attendees presented recently obtained data on the newly discovered Hg containing superconductors which have reported T(c)'s as high as 133 K. This summary is divided into sections, each section dealing with a particular superconducting system. The final section consists of suggested priorities for future phase equilibria studies reached by consensus of the attendees. C1 NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RP PETERSON, D (reprint author), LOS ALAMOS NATL LAB,CTR SUPERCONDUCT TECHNOL,LOS ALAMOS,NM 87545, USA. NR 10 TC 0 Z9 0 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD MAY PY 1994 VL 2 IS 5 BP 367 EP 372 DI 10.1016/0964-1807(94)90022-1 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA PH677 UT WOS:A1994PH67700006 ER PT J AU BENZ, AO GUDEL, M AF BENZ, AO GUDEL, M TI THE SOFT-X-RAY MICROWAVE RATIO OF SOLAR AND STELLAR FLARES AND CORONAE SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE STARS, ACTIVITY; SUN, FLARES; RADIO CONTINUUM, STARS; X-RAYS, STARS; STARS, CORONAE; STARS, FLARE ID RS-CANUM-VENATICORUM; ACTIVE BINARY-SYSTEMS; RADIO-CONTINUUM; EMISSION; STARS; RADIATION; EINSTEIN AB We have carried out plasma diagnostics of solar flares using soft X-ray (SXR) and simultaneous microwave observations and have compared the ratio of X-ray to microwave luminosities of solar flares with various active late-type stars available in the published literature. Both the SXR low-level ('quiescent') emission from stellar coronae and the flaring emission from the Sun and stars are generally interpreted as thermal radiations of coronal plasmas. On the other hand, the microwave emission of stars and solar flares is generally attributed to an extremely hot or nonthermal population of electrons. Solar flare SXR are conventionally measured in a narrower and harder passband than the stellar sources. Observations of the GOES-2 satellite in two energy channels have been used to estimate the luminosity of solar flares as it would appear in the ROSAT satellite passband. The solar and stellar flare luminosities fit well at the lower end of the active stellar coronae. The flare SXR/microwave ratio is similar to the ratio for stellar coronae. The average ratio follows a power-law relation L(X) is-proportional-to L(R)0.73 +/- 0.03 over 10 orders of magnitude from solar microflares to RS CVn and FK Com-type coronae. Dwarf Me and Ke stars, and RS CVn stars are also compatible with a linear SXR/microwave relation, but the ratio is slightly different for each type of star. Considering the differerces between solar flares, stellar flares and the various active stellar coronae, the similarity of the SXR/microwave ratios is surprising. It suggests that the energetic electrons in low-level stellar coronae observed in microwaves are related in a similar way to the coronal thermal plasma as flare electrons to the flare thermal plasma, and, consequently, that the heating mechanism of active stellar coronae is a flare-like process. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA. RP BENZ, AO (reprint author), SWISS FED INST TECHNOL, INST ASTRON, CH-8092 ZURICH, SWITZERLAND. RI Guedel, Manuel/C-8486-2015 OI Guedel, Manuel/0000-0001-9818-0588 NR 30 TC 106 Z9 106 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAY PY 1994 VL 285 IS 2 BP 621 EP 630 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NM403 UT WOS:A1994NM40300035 ER PT J AU BEGELMAN, MC LI, ZY AF BEGELMAN, MC LI, ZY TI ASYMPTOTIC DOMINATION OF COLD RELATIVISTIC MHD WINDS BY KINETIC-ENERGY FLUX SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; PLASMAS; RELATIVITY; STARS, MASS LOSS ID ROTATING COMPACT OBJECTS; STELLAR WINDS; HYDROMAGNETIC FLOWS; JETS; PULSARS; MODEL; DISKS AB We study the conditions which lead to the conversion of most Poynting flux into kinetic energy flux in cold, relativistic hydromagnetic winds. It is shown that plasma acceleration along a precisely radial flow is extremely inefficient due to the near cancellation of the toroidal magnetic pressure and tension forces. However, if the flux tubes in a flow diverge even slightly faster than radially, the fast magnetosonic point moves inward from infinity to a few times the light cylinder radius. Once the flow becomes supermagnetosonic, further divergence of the flux tubes beyond the fast point can accelerate the flow via the magnetic nozzle'' effect, thereby further converting Poynting flux to kinetic energy flux. We show that the Grad-Shafranov equation admits a generic family of kinetic energy-dominated asymptotic wind solutions with finite total magnetic flux. The Poynting flux in these solutions vanishes logarithmically with distance. The way in which the flux surfaces are nested within the flow depends only on the ratio of angular velocity to poloidal 4-velocity as a function of magnetic flux. Radial variations in flow structure can be expressed in terms of a pressure boundary condition on the outermost flux surface, provided that no external toroidal field surrounds the flow. For a special case, we show explicitly how the flux surfaces merge gradually to their asymptotes. For flows confined by an external medium of pressure decreasing to zero at infinity we show that, depending on how fast the ambient pressure declines, the final flow state could be either a collimated jet or a wind that fills the entire space. We discuss the astrophysical implications of our results for jets from active galactic nuclei and for free pulsar winds such as that believed to power the Crab Nebula. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. RP BEGELMAN, MC (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 29 TC 140 Z9 140 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 MAY 1 PY 1994 VL 426 IS 1 BP 269 EP 278 DI 10.1086/174061 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NG668 UT WOS:A1994NG66800028 ER PT J AU CURRIE, LA SHEFFIELD, AE RIEDERER, GE AF CURRIE, LA SHEFFIELD, AE RIEDERER, GE TI IMPROVED ATMOSPHERIC UNDERSTANDING THROUGH EXPLORATORY DATA-ANALYSIS AND COMPLEMENTARY MODELING - THE URBAN K-PB-C SYSTEM SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE CARBONACEOUS AEROSOL; URBAN POLLUTION; SOURCE APPORTIONMENT; CARBON ISOTOPES; ELEMENTAL TRACERS; MULTIPLE LINEAR REGRESSION; POLYCYCLIC AROMATIC HYDROCARBONS; EXPLORATORY DATA ANALYSIS; URBAN ATMOSPHERIC SIGNATURE; WOODBURNING AEROSOL; MOTOR VEHICLE AEROSOL BIOMASS BURNING AB Univariate and multivariate exploration of urban carbonaceous aerosol data have revealed some interesting and important facets of aerosol carbon characteristics, sources and modeling assumptions. Data were obtained from wintertime sampling in Albuquerque-a time and location for which the two-source (motor vehicle, woodburning) aerosol carbon hypothesis is believed valid. Carbon isotopic tracers (C-14, C-12) provided a unique, absolute and direct means for tracing and quantifying fossil carbon and wood carbon contributions to the total aerosol carbon. Lead and mineral-corrected potassium served as unique, but indirect and uncalibrated (non-absolute) tracers for the two carbonaceous aerosol sources. Results for the two models showed excellent consistency for daytime carbon and good agreement for most samples, but the indirect tracer model underpredicted woodcarbon aerosol at night. Multivariate data exploration, including temperature as well as both elemental and organic (polycyclic) tracers suggested that the regression lack of fit, and excess nocturnal wood carbon were due to a third 'statistical'' component in the data. which in turn reflects a chemical non-linearity, apparently associated with volatility. Important conclusions from analysis of the combined isotopic, elemental and organic data from this study are that: (1) high molecular weight, condensed polycyclic hydrocarbons [benzo (ghi) perylene and coronene] appeared to be effective tracers for motor-vehicle carbon; and (2) at least two independent aerosol carbon components derived from woodburning, one of which-presumably involving volatile-to-aerosol carbon condensation-was uncoupled from elemental (K) tracer emissions from woodburning. Finally, some insight was gained into the process of characterizing urban and regional aerosol ''fingerprints'' on the basis of the observed variance-covariance structure of their isotopic and elemental composition. This was illustrated for the wintertime Albuquerque atmosphere, which was found to exhibit a bi-polar signature. C1 ALLEGHENY COLL,MEADVILLE,PA 16335. UNIV MARYLAND,COLL PK,MD 20742. RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 20 Z9 20 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1994 VL 28 IS 8 BP 1359 EP 1369 DI 10.1016/1352-2310(94)90199-6 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR411 UT WOS:A1994NR41100002 ER PT J AU SHEFFIELD, AE GORDON, GE CURRIE, LA RIEDERER, GE AF SHEFFIELD, AE GORDON, GE CURRIE, LA RIEDERER, GE TI ORGANIC, ELEMENTAL, AND ISOTOPIC TRACERS OF AIR-POLLUTION SOURCES IN ALBUQUERQUE, NM SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE RECEPTOR MODELING; RADIOCARBON; WOODSMOKE; RETENE; SEMIVOLATILE ORGANIC COMPOUNDS ID POLYCYCLIC AROMATIC-HYDROCARBONS; ACCELERATOR MASS-SPECTROMETRY; RESIDENTIAL WOOD COMBUSTION; CAPILLARY GAS-CHROMATOGRAPHY; MICROGRAM SAMPLES; CHEMICAL CHARACTERIZATION; CARBONACEOUS PARTICLES; SOURCE APPORTIONMENT; PARTICULATE MATTER; MOLECULAR MARKER AB To explore the use of organic compounds as tracers for air pollution sources, data for radiocarbon, trace elements, carbon, and low-polarity organic compounds were obtained for Albuquerque, NM, in December 1985. Measurement of radiocarbon in the organic fraction permitted unambiguous discrimination of modem carbon (wood burning) and fossil carbon (motor vehicle emissions). Modern and fossil carbon co-varied at night, but during the day, modern carbon was correlated with retene, a proposed tracer for softwood combustion. Similar diurnal differences were observed in a multiple linear regression of elemental tracers of woodsmoke and motor vehicle emissions. Using a physical adsorption model, the gas particle distribution of semi-volatile organic compounds in the samples was estimated. The results suggest that, for some compounds, distribution between the gas and particle phases may act as a third 'source'' affecting measured particulate concentrations. Supporting this conclusion, a factor analysis of the daytime data gave three factors associated with woodsmoke, motor vehicles, and volatile species, respectively. C1 UNIV MARYLAND, DEPT CHEM & BIOCHEM, COLL PK, MD 20742 USA. NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. RP SHEFFIELD, AE (reprint author), ALLEGHENY COLL, DEPT CHEM, MEADVILLE, PA 16335 USA. NR 62 TC 42 Z9 43 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1994 VL 28 IS 8 BP 1371 EP 1384 DI 10.1016/1352-2310(94)90200-3 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR411 UT WOS:A1994NR41100003 ER PT J AU Strom, J Heintzenberg, J Noone, KJ Noone, KB Ogren, JA Albers, F Quante, M AF Strom, J. Heintzenberg, J. Noone, K. J. Noone, K. B. Ogren, J. A. Albers, F. Quante, M. TI Small crystals in cirriform clouds: A case study of residue size distribution, cloud water content and related cloud properties SO ATMOSPHERIC RESEARCH LA English DT Article AB In-situ measurements with the counterflow virtual impactor (CVI) during the ICE-89 campaign are presented. These include measurements of size distribution of ice crystal residues and independent measurements of crystal number concentration and cloud water content (CWC). The investigated clouds appeared to consist predominantly of small ice crystals with a number density weighted radius of mean mass (RMM) of less than 30 mu m. This is also supported by a comparison of the CVI and concurrent PMS 2D2-C probe data. Crystal number concentrations and CWC were low and typically less than 301(-1) and 3 mg m(-3) respectively. The flight average residual size distributions, as measured by the PMS ASASP-X-SP, showed two very distinct modes around 0.17 mu m and 0.35 mu m radius. A closer look at the evolution of the residual distribution as a function of time, revealed that the modes usually do not appear together, but rather excluded each other. C1 [Strom, J.; Heintzenberg, J.] Stockholm Univ, Dept Meteorol MISU, S-10691 Stockholm, Sweden. [Noone, K. J.; Noone, K. B.] Atmos Chem Dept, Sch Oceanog, Narragansett, RI 02882 USA. [Ogren, J. A.] NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. [Albers, F.; Quante, M.] Inst Phys, D-2054 Geesthacht, Germany. RP Strom, J (reprint author), Stockholm Univ, Dept Meteorol MISU, S-10691 Stockholm, Sweden. RI Ogren, John/M-8255-2015; Noone, Birgitta/I-8825-2016 OI Ogren, John/0000-0002-7895-9583; Noone, Birgitta/0000-0001-8165-3887 NR 22 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD MAY PY 1994 VL 32 IS 1-4 BP 125 EP 141 DI 10.1016/0169-8095(94)90056-6 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V38LJ UT WOS:000209344600011 ER PT J AU KLOKOCNIK, J WAGNER, CA AF KLOKOCNIK, J WAGNER, CA TI A TEST OF GEM T2 FROM GEOSAT CROSSOVERS USING LATITUDE LUMPED COEFFICIENTS SO BULLETIN GEODESIQUE LA English DT Article ID ALTIMETRY; TIDES AB New Latitude Lumped Coefficients (LLC) of a geopotential model are defined as representing the principal differences of the radial distance to a satellite due to the model at single-orbit crossovers in an Exact Repeat Mission. In contrast with previously defined orbital lumped coefficients, the LLC here are dependent only on the geopotential order (without degree distinction) and the latitude. We examine discrepancies in altimetrically determined sea surface heights at over 30000 crossover positions or GEOSAT during its ERM, 1986-1989, after removal of many variable media and surface effects (Chency et al., 1991) as well as initial condition orbit error. The mean of these discrepancies along well represented latitude bands in the southern hemisphere are used to determine the LLC errors for Goddard Earth model T2, which was the reference for the GEOSAT sea surface heights. GEM T2 was derived from satellite-only tracking data with good representation of the GEOSAT orbit. Relating the ''measured'' LLC discrepancies to projections of commission error from the GEM T2 variance-covariance matrix, we find that - except for order 3 - GEM T2's performance is as expected. This test represents the first spectral calibration of a gravity model with independent, purely radial orbit data. C1 NOAA,SILVER SPRING,MD 20910. RP KLOKOCNIK, J (reprint author), CZECHOSLOVAK ACAD SCI,INST ASTRON,CS-25165 ONDREJOV OBSERVA,CZECHOSLOVAKIA. RI Klokocnik, Jaroslav/G-9025-2014 NR 27 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4632 J9 B GEOD JI Bull. Geod. PD MAY PY 1994 VL 68 IS 2 BP 100 EP 108 DI 10.1007/BF00819386 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NL004 UT WOS:A1994NL00400004 ER PT J AU HUDSON, JH HANSON, KJ HALLEY, RB KINDINGER, JL AF HUDSON, JH HANSON, KJ HALLEY, RB KINDINGER, JL TI ENVIRONMENTAL IMPLICATIONS OF GROWTH-RATE CHANGES IN MONTASTREA-ANNULARIS - BISCAYNE-NATIONAL-PARK, FLORIDA SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID SPIN-OFF EDDIES; CORAL; RECORD AB Long-term annual growth rates were determined for 25 Montastrea annularis colonies at eight reef sites in Biscayne National Park, Florida, X-radiographs of slabbed coral cores revealed chronologies that averaged 113.5 years in length with a range of 40 to 242 years. A total of 2,837 annual growth increments were identified and measured. Dating of density bands was verified by visually crossdating fluorescent bands within the coral skeleton. Average accretion rates of individual colonies varied from 5.0 mm.yr-1 in the northernmost sector of the Park to 11.3 mm.yr-1 in the southernmost sector. Long-term growth rates of most corals in this study were greatest prior to about 1950 except for a major, 3-5 year, decline in the growth record of older corals centered around 1878. Waxing and waning coral growth rates are discussed in relation to natural and anthropogenic perturbations that impact this high latitude reef ecosystem. Attention is drawn to nutrients from sewage outfalls as a possible contributing factor to observed growth rate decline since 1950. C1 US GEOL SURVEY,COASTAL CTR,ST PETERSBURG,FL 33701. RP HUDSON, JH (reprint author), KEY LARGO NATL MARINE SANCTUARY,POB 1083,KEY LARGO,FL 33037, USA. RI kohki, sowa/D-2955-2011 NR 30 TC 39 Z9 42 U1 0 U2 3 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 MAY PY 1994 VL 54 IS 3 BP 647 EP 669 PG 23 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700006 ER PT J AU HALLEY, RB SWART, PK DODGE, RE HUDSON, JH AF HALLEY, RB SWART, PK DODGE, RE HUDSON, JH TI DECADE-SCALE TREND IN SEA-WATER SALINITY REVEALED THROUGH DELTA-O-18 ANALYSIS OF MONTASTRAEA-ANNULARIS ANNUAL GROWTH BANDS SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID STABLE ISOTOPES; FLORIDA BAY; REEF; CORALS; CARBONATES; OXYGEN AB Stable oxygen isotope ratios (delta18O) of coral skeletons are influenced by ambient water temperature and by the oxygen isotope ratio in the surrounding sea water, which, in turn, is linked to evaporation (salinity) and precipitation. To investigate this relationship more thoroughly, we collected hourly temperature data from the Hen and Chickens Reef in the Florida Keys between 1975 and 1988 and compared them to the deltaO-18 of Montastraea annularis skeleton that grew during the same interval. To ensure that we obtained the correct oxygen isotopic range in the skeleton we typically sampled the coral at a resolution of 20-30 samples in 1 year; in 1 year we sampled the coral at a resolution of 70 samples.year-1. Despite our high-resolution sampling, we were unable to obtain the full temperature-induced deltaO-18 range in the skeleton. Our data suggest that, during the summer, evaporation causes isotopic enrichment in the water, partially masking the temperature-induced signal. Our data also show that oxygen isotopic composition of seawater at the reef has increased since 1981. This increase indicates that salinity has increased slightly during the past decade, perhaps as a result of increased evaporation in waters of Florida Bay and the Keys. This phenomenon is probably not caused by a decrease in the outflow of freshwater into Florida Bay from the Everglades but may be related to the measured deficit in precipitation that has occurred over the past decade. C1 NOAA,FLORIDA KEYS NAT MARINE SANCTUARY,KEY LARGO,FL 33037. UNIV MIAMI,RSMAS,MGG,STABLE ISOTOPE LAB,MIAMI,FL 33149. NOVA UNIV,CTR OCEANOG,DANIA,FL 33004. RP HALLEY, RB (reprint author), US GEOL SURVEY,CTR COASTAL GEOL,COASTAL CTR,600 4TH ST S,ST PETERSBURG,FL 33701, USA. RI Swart, Peter/K-7041-2016 NR 30 TC 11 Z9 12 U1 0 U2 2 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 MAY PY 1994 VL 54 IS 3 BP 670 EP 678 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700007 ER PT J AU THAYER, GW MURPHEY, PL LACROIX, MW AF THAYER, GW MURPHEY, PL LACROIX, MW TI RESPONSES OF PLANT-COMMUNITIES IN WESTERN FLORIDA BAY TO THE DIE-OFF OF SEAGRASSES SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID ABUNDANCE; HABITATS AB Seagrass habitats in western Florida Bay have been undergoing changes from monotypic Thalassia testudinum meadows to large landscapes of barren bottoms or to increasingly heterogeneous Thalassia meadows as a result of seagrass die-off patch formation. The cause of this die-off is unknown but current hypotheses point to environmental stress making this seagrass susceptible to disease. The potential exists for colonization and recovery of these die-off patches but the sequence of events and the persistence of the recovery have not been evaluated. Based on an existing model that represents theoretical successional steps toward the Thalassia climax, four habitat types were sampled in each of two basins of western Florida Bay. Data demonstrated a high potential for recovery of the denuded die-off patches. The alga Batophora oerstedi is the first colonizer with replacement by other algal species and subsequently Halodule wrightii and eventually Thalassia. Under the existing conditions of high resuspended carbonate sediment and biological turbidity, which are thought to be secondary responses of the system to the die-off of seagrasses, persistence of the colonizing habitats and the climax community itself is tenuous. Decreases in both Halodule and Thalassia in non-die-off areas of Johnson Key Basin between spring and fall 1991 occurred as did decreases in densities of these species in recovering patches. Subsequent visits in 1993 revealed that the sample sites were devoid of seagrasses. RP THAYER, GW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,101 PIVERS ISL RD,BEAUFORT,NC 28516, USA. NR 14 TC 31 Z9 33 U1 1 U2 7 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 MAY PY 1994 VL 54 IS 3 BP 718 EP 726 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700010 ER PT J AU CHA, SS MCGOWAN, MF RICHARDS, WJ AF CHA, SS MCGOWAN, MF RICHARDS, WJ TI VERTICAL-DISTRIBUTION OF FISH LARVAE OFF THE FLORIDA-KEYS, 26 MAY 5 JUNE 1989 SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID ICHTHYOPLANKTON; MIGRATIONS; MOVEMENTS; DENSITY; PREY; SEA AB A preliminary description of the vertical distribution of fish larvae offshore of the Florida Keys was derived from quantitative analysis of the fish families represented in the catch from selected stations on the 26 May to 5 June 1989 cruise of Project SEFCAR (Southeastern Florida and Caribbean Recruitment). Eight nighttime samples were taken at stations > 150 m deep by MOCNESS tows with individual nets sampling 25 m vertical depth strata. Larvae of 65 families of fishes were identified. The depth distribution of the 14 most abundant families was explored. These families comprised three groups based on the observed depth of 50% or more of their abundance. The Scombridae, Carangidae, Labridae, and Bothidae occurred <25 m deep. The Gonostomatidae, Gobiidae, Myctophidae, Serranidae, Paralepididae, Scorpaenidae, and Bregmacerotidae occurred <50 m deep. The Paralichthyidae, Synodontidae, and Phosichthyidae occured >50 m deep. The larvae of the remaining 51 families also could be assigned to these three vertical depth categories with approximately equal numbers of families in each depth category but greatest total abundance in the second category (0-50 m). C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI,FL 33149. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV MARINE BIOL & FISHERIES,MIAMI,FL 33149. RP CHA, SS (reprint author), CHONNAM NATL UNIV,COLL NAT SCI,DEPT OCEANOG,KWANGJU 500757,SOUTH KOREA. NR 31 TC 25 Z9 25 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 MAY PY 1994 VL 54 IS 3 BP 828 EP 842 PG 15 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700019 ER PT J AU LIMOUZYPARIS, C MCGOWAN, MF RICHARDS, WJ UMARAN, JP CHA, SS AF LIMOUZYPARIS, C MCGOWAN, MF RICHARDS, WJ UMARAN, JP CHA, SS TI DIVERSITY OF FISH LARVAE IN THE FLORIDA-KEYS - RESULTS FROM SEFCAR SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI AB The ichthyoplankton collections of SEFCAR (Southeast Florida and Caribbean Recruitment Project) contain a highly diverse mixture of larvae from fishes of the Caribbean, Gulf of Mexico, Florida Keys, and the Florida Current. Larvae from 91 families of fishes were collected at 29 MOCNESS stations near the Florida Keys in May and June 1989. The nine most abundant families were Bregmacerotidae, Myctophidae, Gobiidae, Bothidae, Gonostomatidae, Serranidae, Scombridae, Clupeidae, and Carangidae in that order. Each of these families made up more than 2% of the total of 20,052 larvae. The most specious families were the Myctophidae(31), Serranidae(12), Ophichthidae(8), and Scombridae(7); the Congridae, Labridae, and Paralichthyidae all had 6 species. Of 68 Florida Keys fish families associated with coral reefs, we collected larvae of 43 families during 1 week of sampling. Illustrations are provided of Liopropoma sp., and Eupomacentrus leucostictus. The high biodiversity of fish larvae near the Florida Keys may be a sensitive indicator for the effects of climate change and human impacts on the regional fish fauna. Comprehensive identifications and descriptions of fish larvae help establish the baseline from which to document changes. C1 CHONNAM NATL UNIV,COLL NAT SCI,DEPT OCEANOG,KWANGJU 500757,SOUTH KOREA. NOAA,NMFS,SE FISHERIES SCI CTR,MIAMI,FL 33149. RP LIMOUZYPARIS, C (reprint author), UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,4600 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. OI Paris, Claire/0000-0002-0637-1334 NR 12 TC 19 Z9 21 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 MAY PY 1994 VL 54 IS 3 BP 857 EP 870 PG 14 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700021 ER PT J AU BOHNSACK, JA HARPER, DE MCCLELLAN, DB AF BOHNSACK, JA HARPER, DE MCCLELLAN, DB TI FISHERIES TRENDS FROM MONROE COUNTY, FLORIDA SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID SOUTHEASTERN UNITED-STATES; MANAGEMENT; POPULATION; CATCH AB Fishing is an important activity in the Florida Keys National Marine Sanctuary (FKNMS). Concern exists that excessive fishing could be deleterious to individual species, disrupt marine ecosystems, and damage the overall economy of the Florida Keys. We examined data from commercial, recreational, and marine life fisheries in Monroe County, Florida. Invertebrates comprised the majority of commercial landings. In 1992, the total reported commercial landings were composed of 52% invertebrates (4.09 x 10(6) kg), 28% reef fishes (2.19 x 10(6) kg), and 21% non-reef fishes (1.62 x 10(6) kg). In the recreational headboat fishery, reef fishes accounted for 92% of 0.107 x 10(6) kg average total annual landings from the Dry Tortugas and 86% of 0.201 x 10(6) kg landed from the Florida Keys since 1981. Average annual landings for other recreational fisheries were estimated at 1.79 x 10(6) kg for reef fishes (45%) and 2.17 x 10(6) kg for non-reef fishes (55%) from 1980 through 1992. Finer resolution of catch and effort data are needed, especially for recreational fisheries. Landings for some species varied greatly over time. The most conspicuous declines were for pink shrimp, combined grouper, and king mackerel while the most conspicuous increases were for amberjack, stone crab, blue crab, and yellowtail snapper. Landings of spiny lobster have generally remained constant. Fisheries closed to harvest included queen conch, Nassau grouper, jewfish, and stony corals. Effective fishing effort has increased over time with more participants and more effective fishing technology. Since 1965, the number of registered private recreational vessels has increased over six times, while the number of commercial and headboat vessels has remained stable. The number of management actions have continually increased and become more restrictive with increased fishing effort. Comparison of fisheries was complicated because different fisheries targeted different species and different sized organisms. Also, landings were sometimes reported by numbers and sometimes by weight. Measures of reproductive value and spawning potential are suggested as useful parameters for comparing effects of different fisheries. The new FKNMS provides a unique opportunity to shift management emphasis from a species approach to an ecosystem and habitat based approach. RP BOHNSACK, JA (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI LAB,75 VIRGINIA BEACH DR,MIAMI,FL 33149, USA. NR 35 TC 49 Z9 52 U1 0 U2 9 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 MAY PY 1994 VL 54 IS 3 BP 982 EP 1018 PG 37 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700031 ER PT J AU SCHIRRIPA, MJ GOODYEAR, CP AF SCHIRRIPA, MJ GOODYEAR, CP TI SIMULATION MODELING OF CONSERVATION STANDARDS FOR SPOTTED SEA-TROUT (CYNOSCION-NEBULOSUS) IN EVERGLADES-NATIONAL-PARK SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID FLORIDA BAY AB A stock assessment was conducted on the spotted seatrout (Cynoscion nebulosus) stock of Florida Bay in Everglades National Park including simulated outcomes of six possible regulatory options. Female ovarian weight (grams) was regressed on total length (inches) (ovarian weight = 9.62E-04.total length3.542661; r = 0.78). Annual estimates of fishing mortality (F) for fully recruited fish (age 4-8) ranged from F = 0.28 in 1981 to F = 0.91 in 1974 with an overall average of F = 0.54. Annual estimates of spawning potential ratio ranged from a low of 28% in 1974 to a high of 35% in 1981. Yield-per-recruit analysis suggests that with 10% release mortality the fishery is now operating very near the level of mortality that would produce the maximum yield-per-recruit. However, a 25% release mortality would place the fishery beyond this level. Simulations indicate that if fishing mortality continues at the estimated levels for 1990 then increasing the minimum size to 16 inches would increase yield-per-recruit by 15% and increase the spawning potential ratio to 40% within 5 years. RP SCHIRRIPA, MJ (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES CTR,MIAMI LAB,MIAMI,FL 33149, USA. NR 25 TC 5 Z9 5 U1 0 U2 2 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 MAY PY 1994 VL 54 IS 3 BP 1019 EP 1035 PG 17 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700032 ER PT J AU KLEIN, CJ ORLANDO, SP AF KLEIN, CJ ORLANDO, SP TI A SPATIAL FRAMEWORK FOR WATER-QUALITY MANAGEMENT IN THE FLORIDA-KEYS-NATIONAL-MARINE-SANCTUARY SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 1992 Symposium on Florida Keys Regional Ecosystem CY NOV, 1992 CL MIAMI, FL SP ROSENSTIEL SCH, COOPERAT INST MARINE & ATOMOSPHER STUDIES, CTR MARINE & ENV ANAL, NOAA, NATL UNDERSEA RES PROGRAM, SE FISHERIES SCI CTR, ATLANT OCEANOG & METEOROL LAB, NATL SCI FDN, SIGMA XI ID SPIN-OFF EDDIES; VARIABILITY AB This paper establishes a spatial framework for the analysis of water quality behavior in the Florida Keys National Marine Sanctuary. It defines subareas as based upon the variability of circulation behavior and its affect on water quality. The spatial domains are suggested for the aggregation and analysis of data as affected by the circulation characteristics of the subarea for both strategic and tactical issues. The framework recognizes nine unique circulation regimes as based upon our current understanding of the circulation dynamics within the sanctuary and its surrounding waters. Application of the framework is viewed as part of an interative process as ongoing research and monitoring provide the basis for its refinement and use in the development of area specific water quality management strategies. RP KLEIN, CJ (reprint author), NOAA,NATL OCEAN SERV,NIORCA 13,1305 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 10 TC 9 Z9 9 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 MAY PY 1994 VL 54 IS 3 BP 1036 EP 1044 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PQ267 UT WOS:A1994PQ26700033 ER PT J AU MENZEL, WP PURDOM, JFW AF MENZEL, WP PURDOM, JFW TI INTRODUCING GOES-I - THE 1ST OF A NEW-GENERATION OF GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VAS AB In the spring of 1994, the first of the National Oceanic and Atmospheric Administration's (NOAA's) next generation of geostationary satellites, GOES-I, is scheduled for launch. The introduction of this major component of NOAA's modernization represents a significant advance in geostationary remote sensing. All major components of the GOES-I system are new or greatly improved: 1) the satellite is earth oriented to improve instrument performance; 2) sounding and imaging operations are now performed by different and separate instruments; 3) a five-band multispectral radiometer with higher spatial resolution improves imaging capabilities; 4) a sounder with higher radiometric sensitivity enables operational temperature and moisture profile retrieval from geostationary altitude for the first time; 5) a different data format is used to retransmit raw data to direct-receive users; and 6) a new ground data processing system handles the high data volume and distributes advanced products to a variety of users. This article describes the features of the GOES-I spacecraft and instruments, imaging and sounding schedules, data handling systems, and remote sensing products. Simulations of GOES-I imager and sounder products are presented and compared with GOES-I products. The simulations show that GOES-I imagery, derived product images, and sounder products should be significant improvements in both frequency of coverage and accuracy. C1 NOAA,NTL ENVIRONM SATELLITE DATA & INFORMAT SERV,REG & MESOSCALE METEOROL BRANCH,FT COLLINS,CO. RP MENZEL, WP (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ADV SATELLITE PROD PROJECT,ROOM 201,MADISON,WI 53706, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 29 TC 245 Z9 248 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1994 VL 75 IS 5 BP 757 EP 781 DI 10.1175/1520-0477(1994)075<0757:IGITFO>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NP066 UT WOS:A1994NP06600001 ER PT J AU LANDIS, RC AF LANDIS, RC TI FORECASTING IN METEOROLOGY - COMMENT SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP LANDIS, RC (reprint author), NOAA,NATL WEATHER SERV,1325 E W HIGHWAY,ROOM 18164,SILVER SPRING,MD 20910, USA. NR 13 TC 5 Z9 5 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 MAY PY 1994 VL 75 IS 5 BP 823 EP 877 PG 55 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NP066 UT WOS:A1994NP06600005 ER PT J AU KASPRZAK, KS ZASTAWNY, TH NORTH, SL RIGGS, CW DIWAN, BA RICE, JM DIZDAROGLU, M AF KASPRZAK, KS ZASTAWNY, TH NORTH, SL RIGGS, CW DIWAN, BA RICE, JM DIZDAROGLU, M TI OXIDATIVE DNA-BASE DAMAGE IN RENAL, HEPATIC, AND PULMONARY CHROMATIN OF RATS AFTER INTRAPERITONEAL INJECTION OF COBALT(II) ACETATE SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID MAMMALIAN CHROMATIN; HYDROGEN-PEROXIDE; FREE-RADICALS; CHELATORS; EXCRETION; METAL; CARCINOGENICITY; RADIATION; CO(II); KIDNEY AB DNA base damage was studied in renal, hepatic, and pulmonary chromatin of male and female F344/NCr rats that had been given either 50 or 100 mu mol of Co(II) acetate/kg body wt in a single ip dose and killed 2 or 10 days later. Control rats received 200 mu mol of sodium acetate/kg body wt. Chromatin was isolated from organs and analyzed by gas chromatography/mass spectrometry with selected ion monitoring. The following II products derived from purine and pyrimidine bases in DNA were quantified: 5-hydroxy-5-methylhydantoin, 5-hydroxyhydantoin, 5-(hydroxymethyl)uracil (5-OHMe-Ura), 5-hydroxycytosine (5-OH-Cyt), thymine glycol, 5,6-dihydroxycytosine, 4,6-diamino-5-formamido-pyrimidine (FapyAde),2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua), 7,8-dihyaro-8-oxoadenine,2-oxoadenine, and 7,8-dihydro-8-oxoguanine. The response was organ-specific. Eight of the DNA base products in renal chromatin of Co(II)-treated rats (mostly 5-OH-Cyt and other pyrimidine products), five in hepatic chromatin (mostly FapyGua and other purine products), and two in pulmonary chromatin (5-OHMe-Ura > FapyAde) were increased by 30% to more than 200% over control levels with increasing Co(II) dose. The renal and hepatic, but not pulmonary, DNA base damage tended to increase with time. No significant differences in response were found between male and female rats. The bases determined were typical products of hydroxyl radical attack on DNA, suggesting a role for this radical in the mechanism(s) of DNA damage caused by Co(II) in vivo. Some of these bases have been shown previously to be promutagenic. The present results imply involvement of oxidative DNA base damage in Co(II)-induced genotoxic and carcinogenic effects. C1 NCI,FREDERICK CANC RES & DEV CTR,DYNCORP,PROGRAM RESOURCES INC,BIOL CARCINOGENESIS DEV PRO,FREDERICK,MD 21702. NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP KASPRZAK, KS (reprint author), NCI,FREDERICK CANC RES & DEV CTR,COMPARAT CARCINOGENESIS LAB,BLDG 538,ROOM 205,FREDERICK,MD 21702, USA. NR 40 TC 40 Z9 41 U1 0 U2 4 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 MAY-JUN PY 1994 VL 7 IS 3 BP 329 EP 335 DI 10.1021/tx00039a009 PG 7 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA NL680 UT WOS:A1994NL68000009 PM 8075364 ER PT J AU PURI, R SANTORO, RJ SMYTH, KC AF PURI, R SANTORO, RJ SMYTH, KC TI THE OXIDATION OF SOOT AND CARBON-MONOXIDE IN HYDROCARBON DIFFUSION FLAMES SO COMBUSTION AND FLAME LA English DT Article ID SURFACE GROWTH; ELEVATED-TEMPERATURES; LAMINAR METHANE; GENERATED SOOT; AIR FLAMES; PARTICLES; INCEPTION; KINETICS; RATES; OH AB Quantitative OH . concentrations and primary soot particle sizes have been determined in the soot oxidation regions of axisymmetric diffusion flames burning methane, methane/butane, and methane/1-butene in air at atmospheric pressure. The total carbon flow rate was held constant in these flames while the maximum amount of soot varied by a factor of seven along the centerline. Laser-induced fluorescence measurements of OH . were placed on an absolute basis by calibration against earlier absorption results. The primary size measurements of the soot particles were made using thermophoretic sampling and transmission electron microscopy. OH . concentrations are greatly reduced in the presence of soot particles. Whereas large super-equilibrium ratios are observed in the high-temperature reaction zones in the absence of soot, the OH . concentrations approach equilibrium values when the soot loading is high. The diminished OH . concentrations are found to arise from reactions with the soot particles and only to a minor degree from lower temperatures due to soot radiation losses. Analysis of the soot oxidation rates computed from the primary particle size profiles as a function of time along the flame centerlines shows that OH . is the dominant oxidizer of soot, with O2 making only a small contribution. Higher collision efficiencies of OH . reactions with soot particles are found for the flames containing larger soot concentrations at lower temperatures. A comparison of the soot and CO oxidation rates shows that although CO is inherently more reactive than soot, the soot successfully competes with CO for OH . and hence suppresses CO oxidation for large soot concentrations. C1 PENN STATE UNIV,DEPT MECH ENGN,UNIV PK,PA 16802. NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. NR 48 TC 101 Z9 102 U1 0 U2 10 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 MAY PY 1994 VL 97 IS 2 BP 125 EP 144 DI 10.1016/0010-2180(94)90001-9 PG 20 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA NN987 UT WOS:A1994NN98700001 ER PT J AU TOWNSEND, DW CAMMEN, LM HOLLIGAN, PM CAMPBELL, DE PETTIGREW, NR AF TOWNSEND, DW CAMMEN, LM HOLLIGAN, PM CAMPBELL, DE PETTIGREW, NR TI CAUSES AND CONSEQUENCES OF VARIABILITY IN THE TIMING OF SPRING PHYTOPLANKTON BLOOMS SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID CONTINUOUS PLANKTON RECORDS; NORTH-ATLANTIC OCEAN; ELEMENTAL COMPOSITION; NARRAGANSETT BAY; CRITICAL-DEPTH; DIATOM BLOOM; SEA; ZOOPLANKTON; TEMPERATURE; SUMMER AB Established conceptual models of the initiation and progression of spring phytoplankton blooms are reconsidered in light of recent observations. We use biological simulation modelling as a tool for the analysis of spring plankton blooms in shallow, coastal waters in temperate latitudes of the North Atlantic. The model shows that interannual variability in the timing of bloom initiation arises from year-to-year differences in incident irradiation, as determined by weather (cloudiness). This variability in timing results in some years when the spring bloom occurs in cold water temperatures near 0-degrees-C. Model results suggest that due to low temperature inhibition of heterotrophic consumption, more fresh organic material is delivered to the benthos in these cold-water blooms than when the bloom occurs in waters only 3-degrees-C warmer. Thus we suggest that variable bloom timing can be important to the trophodynamic fate of bloom products. We suggest that variability in timing of spring phytoplankton blooms in offshore and open ocean waters is also related to weather, through controls on the light field and wind mixing. Our analyses of wind-driven vertical mixing demonstrate such blooms can begin following the winter period of deep convection, and prior to the vernal development of stratification, provided that wind speed is below a certain, predictable threshold, which we estimate. In such cases, there may be several spring bloom pulses, each interrupted by self-shading light limitation or vertical mixing events. Eventually the seasonal thermocline develops and nutrient exhaustion curtails bloom production. This means that the spring phytoplankton bloom in offshore and open ocean areas may be significantly more productive, result in more export production, and be more important to the carbon cycle, than has been previously assumed. Furthermore, these features of temperate marine planktonic ecosystems are not only sensitive to annual variations in weather, but also any trends that might result from greenhouse warming or other factors that affect the climate system. C1 NOAA,NATL SEA GRANT COLL PROGRAM,SILVER SPRING,MD 20910. UNIV MAINE,CTR MARINE STUDIES,ORONO,ME 04469. PLYMOUTH MARINE LAB,PLYMOUTH PL1 3DH,ENGLAND. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. RP TOWNSEND, DW (reprint author), UNIV MAINE,DEPT OCEANOG,ORONO,ME 04469, USA. NR 69 TC 126 Z9 127 U1 4 U2 49 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD MAY-JUN PY 1994 VL 41 IS 5-6 BP 747 EP 765 DI 10.1016/0967-0637(94)90075-2 PG 19 WC Oceanography SC Oceanography GA NW695 UT WOS:A1994NW69500001 ER PT J AU YOU, CF BUTTERFIELD, DA SPIVACK, AJ GIESKES, JM GAMO, T CAMPBELL, AJ AF YOU, CF BUTTERFIELD, DA SPIVACK, AJ GIESKES, JM GAMO, T CAMPBELL, AJ TI BORON AND HALIDE SYSTEMATICS IN SUBMARINE HYDROTHERMAL SYSTEMS - EFFECTS OF PHASE-SEPARATION AND SEDIMENTARY CONTRIBUTIONS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID EAST PACIFIC RISE; SEAFLOOR GEOTHERMAL SYSTEMS; BACK-ARC BASIN; DE-FUCA RIDGE; ISOTOPE SYSTEMATICS; GALAPAGOS RIFT; OKINAWA TROUGH; GUAYMAS BASIN; VENT FLUIDS; CHEMISTRY AB Systematic studies of the distributions of B, deltaB-11, NH4, halides (Cl, Br, 1) and trace alkalis (Li, Rb, Cs) in vent fluids, combined with experimental data on super- and subcritical phase separation, provide a method for separating the effects of interaction with basalts and/ or sediments from those of phase separation. This allows a more general understanding of geochemical processes in submarine hydrothermal systems, especially where a connection with sediment is not otherwise obvious (e.g., Endeavour Segment, Juan de Fuca Ridge). Based on B and deltaB-11 corrected for wallrock reactions, all published boron and chloride data from mid-ocean ridge systems (MOR) (e.g., 11-degrees-N, 13-degrees-N and 21-degrees-N of the East Pacific Rise), except for the Endeavour Segment, Juan de Fuca Ridge, are consistent with experimental phase separation data, suggesting a dominant control by the latter process. Fluids from sedimented ridge (SR) (e.g., Escanaba Trough and Guaymas Basin), and from back-arc basins (BAB) (e.g., Mariana Trough, Lau Basin and Okinawa Trough), when compared with mid-ocean ridge data, show expected effects of organic matter and/or sediment contributions. This is particularly noticeable from enhanced levels of Br, I, NH4, and trace alkali metal contents (such as Li, Rb and Cs). High B concentrations and elevated deltaB-11 in Endeavour Segment can be explained by a small, but distinguishable contribution from sediments, which is confirmed by slightly enhanced levels of Br, I and NH4. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV TOKYO,OCEAN RES INST,TOKYO 113,JAPAN. OWFN,NUCL REGULATORY COMMISS,WASHINGTON,DC 20555. RP YOU, CF (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. RI Butterfield, David/H-3815-2016 OI Butterfield, David/0000-0002-1595-9279 NR 48 TC 69 Z9 74 U1 3 U2 18 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 MAY PY 1994 VL 123 IS 1-4 BP 227 EP 238 DI 10.1016/0012-821X(94)90270-4 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NR205 UT WOS:A1994NR20500018 ER PT J AU LIVERMORE, R MCADOO, D MARKS, K AF LIVERMORE, R MCADOO, D MARKS, K TI SCOTIA SEA TECTONICS FROM HIGH-RESOLUTION SATELLITE GRAVITY SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID RIDGE AXIS GRAVITY; MARGINAL BASINS; SOUTH-ATLANTIC; SPREADING RATE; OCEAN; PLATE; ANOMALIES; PACIFIC AB The release of altimetric data from the Geosat Geodetic Mission by the US Navy [1] is leading to a much-improved understanding of tectonics in the Southern Ocean, a region in which remoteness and adverse physical conditions have limited the acquisition of geophysical data by research ships. The Scotia Sea is an outstanding example of back-arc spreading, which is revealed in some detail by free-air gravity anomaly maps derived from the latest release of data acquired south of 30-degrees-S [2]. Sea surface height data for this region have been reduced to a grid of free-air gravity anomalies, and are illustrated here by means of colour shaded relief and contour maps. The new data confirm the existence of a number of inactive spreading ridges within the Scotia Sea and surrounding small basins. The amplitudes and wavelengths of gravity anomalies over these ridges conform, in general, to the expected relationship with spreading rate, except in the central Scotia Sea, where a proposed Miocene slow-spreading ridge appears to have left no clear signature. The spreading ridge axis in the east Scotia Sea comprises seven or more segments, separated by small, mainly sinistral, offsets and exhibits a median valley with depths of 200-1000 m that is reflected in free-air lows of 10-40 mGal. Near both its northern and southern termini, the gravity signature of the ridge becomes less distinct, with a less pronounced axial low. The northernmost segments of the ridge are displaced in a right-lateral sense by a feature which appears to represent a southward migrating non-transform offset. Whereas the process of spreading in Drake Passage and the east Scotia Sea was comparable to mid-ocean ridges, that in the central Scotia Sea may have been disorganized, as observed in some western Pacific back-arc basins. C1 NOAA,NATL OCEAN SERV,SILVER SPRING,MD 20910. RP LIVERMORE, R (reprint author), NERC,BRITISH ANTARCT SURVEY,HIGH CROSS,MADINGLEY RD,CAMBRIDGE CB3 0ET,ENGLAND. RI Marks, Karen/F-5610-2010; McAdoo, Dave/F-5612-2010 OI Marks, Karen/0000-0001-6524-1495; McAdoo, Dave/0000-0002-7533-5564 NR 34 TC 70 Z9 72 U1 0 U2 4 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 MAY PY 1994 VL 123 IS 1-4 BP 255 EP 268 DI 10.1016/0012-821X(94)90272-0 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NR205 UT WOS:A1994NR20500020 ER PT J AU HOBSON, ES AF HOBSON, ES TI ECOLOGICAL RELATIONS IN THE EVOLUTION OF ACANTHOPTERYGIAN FISHES IN WARM-TEMPERATE COMMUNITIES OF THE NORTHEASTERN PACIFIC SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Review DE TROPHIC RELATIONS; COMMUNITY STRUCTURE; LATITUDINAL DIVERSITY GRADIENTS; ZOOGEOGRAPHY ID GREAT BARRIER-REEF; BOTTOM KELP FOREST; HERBIVOROUS FISHES; TELEOSTEAN FISHES; SANTA-BARBARA; CALIFORNIA; ACANTHURIDAE; BIOGEOGRAPHY; SURFPERCHES; PERCIFORMES AB The species composition of acanthopterygian fishes in warm-temperate communities of the northeastern Pacific reflects the influence of ecological relations on teleostean evolution. The species are of either temperate or tropical derivation, with the temperate derivatives (e.g., scorpaeniforms, pleuronectiforms and zoarcoid perciforms) being mostly generalized carnivores, and the tropical derivatives (almost all of them perciforms) ranging from generalized carnivores to a diversity of specialized carnivores and herbivores. The tropical group dominates, with species of the labroid families Pomacentridae, Embiotocidae and Labridae being especially prominent, based mainly on specialized abilities to feed on sessile invertebrates and zooplankters. Other perciforms of tropical stock that do well here include kyphosids, which are herbivores. These trophic capabilities have been inherited from tropical ancestors and are poorly developed among the temperate derivatives. Despite their successes in warm-temperate habitats, few tropical derivatives have extended their distributions into the cold-temperate region; similarly, temperate derivatives have been to a large extent limited in spreading southward into the warm-temperate region. These limits to distribution cannot be attributed to problems with food resources, but are readily explained by effects of surface currents on early life-history stages in this coastal upwelling system. RP HOBSON, ES (reprint author), SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 162 TC 14 Z9 15 U1 1 U2 6 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 MAY PY 1994 VL 40 IS 1 BP 49 EP 90 DI 10.1007/BF00002182 PG 42 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA NL553 UT WOS:A1994NL55300004 ER PT J AU MYERS, RA ROSENBERG, AA MACE, PM BARROWMAN, N RESTREPO, VR AF MYERS, RA ROSENBERG, AA MACE, PM BARROWMAN, N RESTREPO, VR TI IN SEARCH OF THRESHOLDS FOR RECRUITMENT OVERFISHING SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE SPAWNING STOCK BIOMASS; RICKER CURVE; BEVERTON-HOLT CURVE; SHEPHERD CURVE ID MANAGEMENT AB In this study we consider the problem of estimating, for management purposes, a minimum biomass reference level at which recruitment to a fish stock is seriously reduced. We take an empirical-comparative approach to the problem by examining observations on a wide range of fish stocks. Eight methods for estimating spawning stock biomass thresholds for recruitment overfishing are investigated. Their behaviour is tested using stock and recruitment data for 72 finfish populations, each with at least 20 years of data. We considered three classes of thresholds defined by: (1) the stock size corresponding to 50% of the maximum predicted average recruitment; (2) the minimum stock size that would produce a good year class when environmental conditions are favourable; and (3) the stock size corresponding to 20% of various estimates of virgin stock size. The estimators of the first type are generally preferable because they are easily understood, relatively robust if only data at low stock sizes are available, and almost always result in higher levels of recruitment above the threshold. C1 NATL MARINE FISHERIES SERV,WOODS HOLE,MA 02543. SEACONSULT LTD,ST JOHNS A1C 5R6,NF,CANADA. NATL MARINE FISHERIES SERV,SILVER SPRING,MD 20910. UNIV MIAMI,MIAMI,FL 33149. RP MYERS, RA (reprint author), FISHERIES & OCEANS,SCI BRANCH,POB 5667 CANADA,ST JOHNS A1C 5X1,NF,CANADA. NR 20 TC 101 Z9 102 U1 1 U2 16 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 MAY PY 1994 VL 51 IS 2 BP 191 EP 205 DI 10.1006/jmsc.1994.1020 PG 15 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA NZ766 UT WOS:A1994NZ76600006 ER PT J AU EVENSON, KM CHOU, CC BACH, BW BACH, KG AF EVENSON, KM CHOU, CC BACH, BW BACH, KG TI NEW CW CO2-LASER LINES - THE 9-MU-M HOT-BAND SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID TRANSITIONS AB We have made what we think is the first observation of the oscillation of the 9-mum hot-band lines 01(1)1 --> [11(1)0, 03(1)0]II of CO2. We have observed 40 lines with a maximum power of 8 W. They will provide a new source of laser radiation for spectroscopy. The set of lines has been positively identified by directly measuring the frequencies of two of the lines with a heterodyne technique using a CO2 laser standard. C1 NATL TSING HUA UNIV,DEPT PHYS,HSINCHU 30043,TAIWAN. HYPERFINE INC,BOULDER,CO 80301. RP EVENSON, KM (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 6 TC 33 Z9 35 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAY PY 1994 VL 30 IS 5 BP 1187 EP 1188 DI 10.1109/3.303679 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA NY698 UT WOS:A1994NY69800008 ER PT J AU JOHNK, RT KANDA, M AF JOHNK, RT KANDA, M TI ALTERNATIVE CONTOUR TECHNIQUE FOR THE EFFICIENT COMPUTATION OF THE EFFECTIVE LENGTH OF AN ANTENNA SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Note AB The scattering of a plane wave broadside incident to a dipole antenna with a symmetrically placed, open-circuited gap is treated. The induced currents on the antenna are found by solving the electric-field integral equation by means of a Galerkin moment method. The resulting current distribution is then used to compute line integrals of the scattered electric field along appropriate paths. The line integral is first evaluated directly across the dipole gap in order to compute the effective length, but severe convergence problems are encountered. This problem is due to the presence of charge singularities at the gap edges. Instead of incorporating the singular charge behavior into the basis functions, a line integral is evaluated along a path that alleviates the convergence difficulties. This remedy is developed first for an electrostatic case and then for the dynamic scattering problem. RP JOHNK, RT (reprint author), NIST,BOULDER,CO 80303, USA. NR 12 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 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD MAY PY 1994 VL 42 IS 5 BP 747 EP 749 DI 10.1109/8.299577 PG 3 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA NW194 UT WOS:A1994NW19400022 ER PT J AU KHERA, D CRESSWELL, MW LINHOLM, LW RAMANATHAN, G BUZZEO, J NAGARAJAN, A AF KHERA, D CRESSWELL, MW LINHOLM, LW RAMANATHAN, G BUZZEO, J NAGARAJAN, A TI INCREASING PROFITABILITY AND IMPROVING SEMICONDUCTOR MANUFACTURING THROUGHPUT USING EXPERT-SYSTEMS SO IEEE TRANSACTIONS ON ENGINEERING MANAGEMENT LA English DT Article DE QUALITY CONTROL; EXPERT SYSTEM; SEMICONDUCTOR MANUFACTURING; THROUGHPUT; SCREENING; WORK-IN-PROCESS; INDUCTION; KNOWLEDGE BASE AB This paper describes a new procedure for using a machine-learning classification technique coupled with an expert system to increase profitability and improve throughput in a semiconductor manufacturing environment. The authors show how to use this procedure to identify relationships between work-in-process data (information obtained during semiconductor fabrication) and potential integrated circuit yield. The relationships, in the form of IF-THEN rules, are extracted from databases of previously fabricated integrated circuits and final yield. It is further shown that these rules, when incorporated into expert systems, can advise the human operator as to which batches of circuits are likely to produce submarginal yield if processed to completion, thereby providing a basis for developing or enhancing a quality control strategy. These rules also identify the parameters and values which have historically provided the highest and lowest final wafer yields. A cost analysis is given to illustrate the cost-effectiveness of this procedure. An introduction to semiconductor manufacturing and a glossary are provided. C1 IBM CORP,HOPEWELL JCT,NY 12533. RP KHERA, D (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 12 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 0018-9391 J9 IEEE T ENG MANAGE JI IEEE Trans. Eng. Manage. PD MAY PY 1994 VL 41 IS 2 BP 143 EP 151 DI 10.1109/17.293381 PG 9 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA NV885 UT WOS:A1994NV88500006 ER PT J AU FAHR, A BRAUN, W AF FAHR, A BRAUN, W TI ERROR ANALYSIS FOR COMPLEX KINETICS SYSTEMS METHYL-VINYL CROSS-RADICAL REACTIONS SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID SENSITIVITY AB Many rate constants, particularly for radical-radical reactions, are determined in systems exhibiting complex kinetics. Parameters often comprise several species concentrations, absorption cross sections, and rate constants. They cannot be obtained from an exact analytic expression, and therefore, must be solved iteratively through an efficient numerical differential equation solver. We examine here the reaction kinetics of the CH3 and the C2H3 mixed-radical system, generated by excimer laser photolysis of methyl vinyl ketone (MVK) at 193.3 nm. As a model, a detailed error analysis for determination of the cross-radical reaction rate constant, the initial CH3 and C2H3 radical concentrations are performed using a least-squares modeling program (Acufit). The least-squares program, an assumed mechanism, a detailed set of signal-averaged data, are viewed as the measuring ''instrument.'' The output of the ''instrument'' consists of a ''signal'' that is fit to the data using the least-squares criterion. This gives estimated parameters that are examined with respect to random as well as systematic errors. The biases due to uncertainties of each known parameter and combined uncertainties on the measured parameters are assessed. (C) 1994 John Wiley & Sons, Inc.** RP FAHR, A (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 16 TC 5 Z9 5 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 MAY PY 1994 VL 26 IS 5 BP 535 EP 544 DI 10.1002/kin.550260506 PG 10 WC Chemistry, Physical SC Chemistry GA NG296 UT WOS:A1994NG29600005 ER PT J AU LOVEJOY, ER RAVISHANKARA, AR HOWARD, CJ AF LOVEJOY, ER RAVISHANKARA, AR HOWARD, CJ TI YIELD OF (OSO)-O-16-O-18 FROM THE (OH)-O-18 INITIATED OXIDATION OF CS2 IN O-16(2) SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID KINETICS; OH; CONSTANT; OXYGEN AB The yield of (OSO)-O-16-O-18 from the (0H)-O-18 initiated oxidation of CS2 in O-16(2) was measured by using a discharge flow reactor coupled to a chemical ionization mass spectrometer. (OSO)-O-16-O-18 is the dominant SO2 isotopomer produced with a yield of 0.90 +/- 0.20 relative to (OH)-O-18 loss. The errors are estimates for the uncertainty at the 95% confidence level. The implications of these results to the understanding of the CS2 oxidation mechanism are discussed. (C) 1994 John Wiley & Sons, Inc.** C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP LOVEJOY, ER (reprint author), NOAA,AERON LAB,BOULDER,CO 80303, USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 19 TC 9 Z9 9 U1 0 U2 4 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 MAY PY 1994 VL 26 IS 5 BP 551 EP 560 DI 10.1002/kin.550260508 PG 10 WC Chemistry, Physical SC Chemistry GA NG296 UT WOS:A1994NG29600007 ER PT J AU KRAMER, TR AF KRAMER, TR TI ISSUES CONCERNING MATERIAL REMOVAL SHAPE ELEMENT VOLUMES (MSREVS) SO INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING LA English DT Article AB In machining discrete parts, material removal shape element volumes (MRSEVs) may be used to convey shape information from process planning to NC-programming. This paper discusses 16 issues regarding MRSEVs and presents, in summary form, a proposed library of MRSEVs for three-axis machining. RP KRAMER, TR (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,ROOM B-124,BLDG 220,GAITHERSBURG,MD 20899, USA. NR 23 TC 5 Z9 5 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0951-192X J9 INT J COMP INTEG M JI Int. J. Comput. Integr. Manuf. PD MAY-JUN PY 1994 VL 7 IS 3 BP 139 EP 151 DI 10.1080/09511929408944604 PG 13 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA ND721 UT WOS:A1994ND72100001 ER PT J AU MULROY, WJ DOMANSKI, PA DIDION, DA AF MULROY, WJ DOMANSKI, PA DIDION, DA TI GLIDE MATCHING WITH BINARY AND TERNARY ZEOTROPIC REFRIGERANT MIXTURES .1. AN EXPERIMENTAL-STUDY SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE ZEOTROPIC MIXTURES; LORENZ CYCLE; REFRIGERATION; HEAT PUMPING; REFRIGERANT MIXTURES; NONLINEARITY AB An improvement of the coefficient of performance (COP) of the refrigeration cycle can be realized when temperature profiles of the refrigerant mixture and the heat transfer fluid (HTF) are matched. For the same temperature lift, the benefit of glide matching increases as the application glide increases. High-glide binary mixtures composed of components far apart in boiling points tend to have a non-linear relationship between temperature and enthalpy in the two-phase region. The introduction of an intermediate boiler as a third component can linearize this relationship and, theoretically, increase the cycle COP when heat-source and heat-sink fluids are substantially linear (e.g. water, brines, dry air). The research described in this paper was directed at exemplifying this characteristic of ternary mixtures by experimental evaluation of the performance of an R23/142b binary mixture and an R23/22/142b ternary mixture in a generic laboratory breadboard refrigeration system. RP MULROY, WJ (reprint author), NATL INST STAND & TECHNOL,THERMAL MACHINERY GRP,GAITHERSBURG,MD 20899, USA. NR 4 TC 20 Z9 24 U1 1 U2 3 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD MAY PY 1994 VL 17 IS 4 BP 220 EP 225 DI 10.1016/0140-7007(94)90037-X PG 6 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA NE648 UT WOS:A1994NE64800002 ER PT J AU DOMANSKI, PA MULROY, WJ DIDION, DA AF DOMANSKI, PA MULROY, WJ DIDION, DA TI GLIDE MATCHING WITH BINARY AND TERNARY ZEOTROPIC REFRIGERANT MIXTURES .2. A COMPUTER-SIMULATION SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE ZEOTROPIC MIXTURES; BOILING POINTS; REFRIGERANT MIXTURES; SIMULATION AB The glide-matching study presented in Part 1 was a laboratory investigation which demonstrated the evaporator performance in detail. However, since it was not possible to instrument the condenser sufficiently, some computer simulation work was conducted using a semi-theoretical model CYCLE-11, which has been under continual development at NIST for the past five years. As in the experimental effort, R22, R142b, R22/142b, R23/22/142b and R23/142b working fluids were investigated, but the simulation work did not include heat pump operation with liquid-line/evaporator heat exchange. By utilizing the model to quantify entropy generation at various state points within the cycle, it was possible to locate the likelihood of temperature profile pinch points in both the condenser and evaporator. This information clarified the impact of non-linearities on the system performance. RP DOMANSKI, PA (reprint author), NATL INST STAND & TECHNOL,THERMAL MACHINERY GRP,GAITHERSBURG,MD 20899, USA. NR 5 TC 16 Z9 21 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD MAY PY 1994 VL 17 IS 4 BP 226 EP 230 DI 10.1016/0140-7007(94)90038-8 PG 5 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA NE648 UT WOS:A1994NE64800003 ER PT J AU BOYES, SJ WEBER, LA AF BOYES, SJ WEBER, LA TI VAPOR-PRESSURES AND GAS-PHASE PVT DATA FOR 1-CHLORO-1,2,2,2-TETRAFLUOROETHANE (R124) SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE 1-CHLORO-1,2,2,2-TETRAFLUOROETHANE; DENSITY; GAS-PHASE PVT; REFRIGERANT R124; SATURATED VAPOR DENSITY; VAPOR PRESSURES; VIRIAL COEFFICIENTS AB We present new data for the vapor pressure and PVT surface of 1-chloro-1,2,2,2-tetrafluoroethane (designated R124 by the refrigeration industry) in the temperature range 278-423 K. The PVT data are for the gas phase at densities up to 1.5 times the critical density. Correlating equations are given for the vapor pressures from 220 K to the critical temperature, 395.43 K, and for the P VT surface at densities up to 2 mol.L-1 (approximately 0.5 times the critical density). Second and third virial coefficients have been derived from the PVT measurements. RP BOYES, SJ (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 17 TC 16 Z9 16 U1 3 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAY PY 1994 VL 15 IS 3 BP 443 EP 460 DI 10.1007/BF01563707 PG 18 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA NT199 UT WOS:A1994NT19900004 ER PT J AU WEBER, LA AF WEBER, LA TI ESTIMATING THE VIRIAL-COEFFICIENTS OF SMALL POLAR-MOLECULES SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE DENSITY; PVT; POLAR MOLECULES; REFRIGERANTS; VIRIAL COEFFICIENTS ID OF-SOUND MEASUREMENTS; RHO-T MEASUREMENTS; PHASE PVT-DATA; BINARY-MIXTURES; THERMOPHYSICAL PROPERTIES; GASEOUS REFRIGERANTS; VAPOR-PRESSURES; CARBON-DIOXIDE; GAS; SYSTEM AB We adapt existing models for estimating the second and third virial coefficients of small molecules to the halogenated methanes and ethanes. We compare the results with the abundant new, high-quality PVT data resulting from the search for alternative refrigerants. The present model provides an accurate method for calculating densities, and therefore it should provide reliable thermodynamic properties and fugacity coefficients. We give equations and parameters useful for estimating the properties of pure refrigerants and their mixtures when no PVT data are available. RP WEBER, LA (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 40 TC 56 Z9 58 U1 1 U2 5 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 MAY PY 1994 VL 15 IS 3 BP 461 EP 482 DI 10.1007/BF01563708 PG 22 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA NT199 UT WOS:A1994NT19900005 ER PT J AU MCCLURE, JL CEZAIRLIYAN, A AF MCCLURE, JL CEZAIRLIYAN, A TI MEASUREMENT OF THE HEAT OF FUSION OF TANTALUM BY A MICROSECOND-RESOLUTION TRANSIENT TECHNIQUE SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE ELECTRICAL RESISTIVITY; HEAT OF FUSION; HIGH TEMPERATURES; MELTING; PULSE HEATING; REFRACTORY METALS; TRANSIENT TECHNIQUES; TANTALUM ID LIQUID TANTALUM; TUNGSTEN AB The heat of fusion of tantalum was measured using a microsecond-resolution pulse-heating technique. The technique is based on rapid (about 100-mus) resistive self-heating of a specimen by a high-current pulse from a capacitor discharge system and measuring the current through the specimen, voltage across the specimen, and radiance temperature of the specimen as functions of time. Melting of a specimen is manifested by a plateau in the radiance temperature versus time function. The time integral of the power absorbed by the specimen during melting yields the beat of fusion. Measurements gave a value of 34.8 kJ . mol-1 for the heat of fusion of tantalum, with a total uncertainty of +/- 6%. Electrical resistivity of solid and liquid tantalum at its melting temperature was also measured. RP MCCLURE, JL (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 15 TC 2 Z9 2 U1 0 U2 0 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 MAY PY 1994 VL 15 IS 3 BP 505 EP 511 DI 10.1007/BF01563710 PG 7 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA NT199 UT WOS:A1994NT19900007 ER PT J AU MATROSOV, SY ORR, BW KROPFLI, RA SNIDER, JB AF MATROSOV, SY ORR, BW KROPFLI, RA SNIDER, JB TI RETRIEVAL OF VERTICAL PROFILES OF CIRRUS CLOUD MICROPHYSICAL PARAMETERS FROM DOPPLER RADAR AND INFRARED RADIOMETER MEASUREMENTS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RADIATIVE PROPERTIES; SCATTERING AB This paper describes a new method to retrieve vertical profiles of the parameters of cirrus cloud microphysics that are important for the estimation of climatic feedback. These parameters are the particle characteristic size and ice mass content. The method also allows calculations of vertical profiles of particle concentrations and ice mass flux. The method uses measurements of radar reflectivities and Doppler velocities from the ground-based zenith-viewing radar combined with measurements of downwelling brightness temperatures from an infrared radiometer operating in the ''window'' (10-12 mum) region. The proposed method is illustrated on data obtained on 26 November 1991 during FIRE-II [First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment] in Coffeyville, Kansas. This paper also presents estimates of uncertainties of parameter retrieval due to different a priori assumptions about particle shapes, distributions, fall velocity-size relationships and due to errors in measurements. Comparisons with in situ measurements showed reasonable agreement. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. RP MATROSOV, SY (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,ETL 325 BROADWAY,R-E-ET6,BOULDER,CO 80303, USA. NR 20 TC 64 Z9 64 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAY PY 1994 VL 33 IS 5 BP 617 EP 626 DI 10.1175/1520-0450(1994)033<0617:ROVPOC>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NJ724 UT WOS:A1994NJ72400004 ER PT J AU STEIN, SE BROWN, RL AF STEIN, SE BROWN, RL TI ESTIMATION OF NORMAL BOILING POINTS FROM GROUP CONTRIBUTIONS SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article ID COMPONENT VAPOR-PRESSURES; UNIFAC GROUP-CONTRIBUTION; PREDICTION AB A group contribution method for normal boiling point estimations was developed using a data base of 4426 diverse organic compounds. With this data set, boiling point predictions had a average absolute error of 15.5 K corresponding to a 3.2 average percent error. For a data set of 6584 other compounds, not used in deriving the method, the average absolute error was 20.4 K with a 4.3 average percent error. A vapor pressure equation was tested and used to extrapolate boiling points measured at reduced pressure. Thus this method may also be used to predict vapor pressures. RP STEIN, SE (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899, USA. NR 15 TC 149 Z9 152 U1 5 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD MAY-JUN PY 1994 VL 34 IS 3 BP 581 EP 587 DI 10.1021/ci00019a016 PG 7 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA NN745 UT WOS:A1994NN74500016 ER PT J AU HELLER, SR BIGWOOD, DW MAY, WE AF HELLER, SR BIGWOOD, DW MAY, WE TI EXPERT-SYSTEMS FOR EVALUATING PHYSICOCHEMICAL PROPERTY-VALUES .1. AQUEOUS SOLUBILITY SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article ID HENRY LAW CONSTANTS; WATER SOLUBILITY; POLYCHLORINATED-BIPHENYLS; PARTITION-COEFFICIENT; ALKYLBENZENES; INSECTICIDES; HYDROCARBONS; TEMPERATURE; PESTICIDES; CHEMICALS AB Providing consistent data evaluation is critical to scientific studies. An expert system for evaluating the efficacy of the reported methodology for determining aqueous solubility is described and compared with two other similar manual data quality evaluation systems. The expert system, SOL, is a post-peer review filter for data evaluation. SOL has been designed to run on any IBM-PC compatible computer using the CLIPS public domain expert system shell. C1 USDA,NATL AGR LAB,BELTSVILLE,MD 20705. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP HELLER, SR (reprint author), USDA ARS,BELTSVILLE AGR RES CTR,NPS,BELTSVILLE,MD 20705, USA. NR 55 TC 10 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD MAY-JUN PY 1994 VL 34 IS 3 BP 627 EP 636 DI 10.1021/ci00019a023 PG 10 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA NN745 UT WOS:A1994NN74500023 ER PT J AU FRASER, GT PATE, BH AF FRASER, GT PATE, BH TI THE MOLECULAR STARK-EFFECT IN REGIONS OF HIGH STATE DENSITY - OVERALL SIMPLICITY AND UNDERLYING COMPLEXITY IN THE RESPONSE TO A STATIC ELECTRIC-FIELD SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-ENERGY REDISTRIBUTION; PENDULAR STATES; MICROWAVE IONIZATION; POLYATOMIC-MOLECULES; CHAOTIC SYSTEMS; SPECTROSCOPY; SPECTRA; FLUORESCENCE; FORMALDEHYDE; ORIENTATION AB We present the high-resolution (11 MHz) infrared measurement of the molecular Stark effect for the R(0) transition of the acetylenic C-H stretch in 2-propyn-1-ol. The field-free spectrum is fragmented into three eigenstate components due to the effects of intramolecular vibrational energy redistribution (IVR). As the field strength increases from 0 to 25 kV/cm, the number of eigenstates increases linearly. The center-of-gravity of the fragmented R(0) transition follows the simple, second-order Stark shift (Delta v alpha E(2)) expected for the bright state. However, when viewed at the eigenstate level, the mechanism of the Stark shift is rather complex. At lower field strengths, the eigenstates shift in energy, as occurs for Stark effects in lower state density regimes. As the number of coupled states increases, energy shifting of the eigenvalues is quenched. To preserve the second-order Stark shift of the center-of-gravity, the intensity ''rolls over'' the largely rigid eigenvalue structure. For molecules in regions of high state density, the reduced energy shifting of the eigenvalues as the electric field is increased means that lack of deflection by inhomogeneous electric fields is not necessarily a consequence of the molecule being nonpolar. RP FRASER, GT (reprint author), NIST, DIV MOLEC PHYS, GAITHERSBURG, MD 20899 USA. NR 60 TC 18 Z9 18 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 1994 VL 100 IS 9 BP 6210 EP 6220 DI 10.1063/1.467084 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NH846 UT WOS:A1994NH84600013 ER PT J AU FROST, MJ KATO, S BIERBAUM, VM LEONE, SR AF FROST, MJ KATO, S BIERBAUM, VM LEONE, SR TI KINETICS AND DYNAMICS OF VIBRATIONALLY STATE-RESOLVED ION-MOLECULE REACTIONS - N-14(2)+ (V=1 AND 2) AND N-15(2)+(V=0, 1, AND 2) WITH N-14(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; CHARGE-TRANSFER REACTIONS; COLLISIONAL RELAXATION; THERMAL ENERGIES; HIGH-RESOLUTION; CROSS-SECTIONS; BINARY COMPLEX; CO+-CO; EXCHANGE; N-2+ AB Vibrationally state-selected measurements of the kinetics and dynamics of N-14(2)+ (upsilon=1 and 2) and N-15(2)+ (upsilon=0, 1, and 2) in collisions with N-14(2) are made using a selected ion flow tube (SIFT), laser induced fluorescence (LIF) technique at thermal energies. Kinetics are measured by monitoring the LIF signal amplitudes of N-2(+) (upsilon) as a function of N-14(2) concentration, added after ion injection. By comparison with the known N-2(+) (upsilon=1) + Ar rate, the N-15(2)+ (upsilon=0) + N-14(2) rate constant is found to be one-half of the Langevin collision rate, or 4.2+/-0.2x10(-10) cm(3) molecule(-1) s(-1). This suggests that the reaction proceeds via an N-4(+) energized adduct in which charge is shared on a time scale shorter than the adduct lifetime. The removal rates of N-14(2)+ (upsilon=1 and 2) with N-14(2) are 21%-26% faster than those for N-14(2)+ (upsilon) with N-14(2) in which both charge and vibrational energy are transferred between the collision partners. This pathway is also observed directly by the appearance of N-14(2)+ (upsilon=1 and 2) product states. For this channel to proceed, vibrational energy transfer between the two highest frequency modes of the N-4(+) energized adduct must occur on a time scale comparable to the adduct lifetime. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP FROST, MJ (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 48 TC 20 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 1994 VL 100 IS 9 BP 6359 EP 6367 DI 10.1063/1.467097 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NH846 UT WOS:A1994NH84600026 ER PT J AU WEIDA, MJ NESBITT, DJ AF WEIDA, MJ NESBITT, DJ TI COLLISIONAL ALIGNMENT OF CO2 ROTATIONAL ANGULAR-MOMENTUM STATES IN A SUPERSONIC EXPANSION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID OPTICAL DOUBLE-RESONANCE; MOLECULAR-BEAM; DIFFERENTIAL SCATTERING; ORIENTED MOLECULES; REORIENTATION; ORIENTATION; POLARIZATION; NA2; HE AB The rotational alignment of CO2 seeded in a supersonic expansion is measured using a general, direct absorption method based on fast (75 kHz) polarization modulation and phase sensitive detection with of a narrow band tunable IR laser. The anisotropic distribution of \M(J)\ states is created by a directed velocity slip between the carrier gas and a nonspherical seed gas. Strong alignment signals are observed in a pinhole expansion that depend systematically on the carrier gas, stagnation pressure, and J state. In a slit expansion, however, no alignment is detected for comparable conditions. The observed effects are quite significant and occur at rather modest expansion conditions (e.g., 2.5% CO2 in He at 1000 Torr). As much as 60% enhancement of n(perpendicular to) /n(parallel to), i.e., the ratio of molecules with J directed perpendicular vs parallel to the expansion axis is obtained. The data indicate that the observed alignment is correlated with the magnitude of the velocity slip, and that elastic collisions where Delta J=0 and Delta M(j) not equal 0 are primarily responsible for creating and sustaining the alignment. C1 NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP WEIDA, MJ (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 54 TC 72 Z9 72 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 1994 VL 100 IS 9 BP 6372 EP 6385 DI 10.1063/1.467047 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NH846 UT WOS:A1994NH84600028 ER PT J AU GUTMAN, GG AF GUTMAN, GG TI GLOBAL DATA ON LAND-SURFACE PARAMETERS FROM NOAA AVHRR FOR USE IN NUMERICAL CLIMATE MODELS SO JOURNAL OF CLIMATE LA English DT Article; Proceedings Paper CT Joint Session on Land-Atmosphere Interactions at Regional and Global Scales, at 10th Conference on Biometeorology and Aerobiology; Special Session on Hydrometeorology CY SEP 10-13, 1991 CL SALT LAKE CITY, UT SP AMER METEOROL SOC ID VEGETATION INDEXES; SATELLITE DATA; ATMOSPHERIC CORRECTION; DATA SET; CLASSIFICATION; MOISTURE; COVER; PREDICTION; ALGORITHM; RADIANCES AB This paper reviews satellite datasets from the NOAA Advanced Very High Resolution Radiometer that could be employed in support of numerical climate modeling at regional and global scales. Presently available NOAA operational and research datasets of different resolutions as well as the NASA-NOAA Pathfinder dataset, a in the near future, are briefly described. Specific problems in deriving surface characteristics in the context of their potential use for models are discussed. Possible ways of solving these problems are briefly described, based on the state-of-the-art level of understanding in this area of research. Some examples of seasonal variability of AVHRR-derived surface parameters, such as albedo, greenness, and clear-sky midafternoon temperature, for different climatic regions are presented. Validation issues and potential operational production of such land climate parameters are discussed. RP GUTMAN, GG (reprint author), NOAA,NESDIS,SATELLITE RES LAB,ERA12,WWB 712,WASHINGTON,DC 20233, USA. NR 66 TC 14 Z9 14 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 MAY PY 1994 VL 7 IS 5 BP 669 EP 680 DI 10.1175/1520-0442(1994)007<0669:GDOLSP>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL465 UT WOS:A1994NL46500005 ER PT J AU TARPLEY, JD AF TARPLEY, JD TI MONTHLY EVAPOTRANSPIRATION FROM SATELLITE AND CONVENTIONAL METEOROLOGICAL OBSERVATIONS SO JOURNAL OF CLIMATE LA English DT Article; Proceedings Paper CT Joint Session on Land-Atmosphere Interactions at Regional and Global Scales, at 10th Conference on Biometeorology and Aerobiology; Special Session on Hydrometeorology CY SEP 10-13, 1991 CL SALT LAKE CITY, UT SP AMER METEOROL SOC ID LAND SURFACE-TEMPERATURE; MOISTURE; MODEL; SET AB Monthly mean satellite measurements of surface heating rate, surface temperature, and normalized difference vegetation index were collected for seven locations in Kansas. These were combined with monthly average surface observations and used in a surface energy balance model to estimate monthly mean evapotranspiration at each site. The modeled evapotranspiration and surface energy fluxes are reasonable. The nature of the surface energy balance model is such that it can be solved with satellite measurements and numerical weather forecast model output alone. This suggests that large-scale evapotranspiration climatologies can be made without in situ observations. RP TARPLEY, JD (reprint author), NOAA,NESDIS,SATELLITE RES LAB,WASHINGTON,DC 20233, USA. NR 26 TC 12 Z9 12 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1994 VL 7 IS 5 BP 704 EP 713 DI 10.1175/1520-0442(1994)007<0704:MEFSAC>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL465 UT WOS:A1994NL46500007 ER PT J AU HOERLING, MP TING, MF AF HOERLING, MP TING, MF TI ORGANIZATION OF EXTRATROPICAL TRANSIENTS DURING EL-NINO SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE TEMPERATURE ANOMALIES; GENERAL-CIRCULATION MODEL; SOUTHERN OSCILLATION; ATMOSPHERIC RESPONSE; WINTERTIME CIRCULATION; NORTHERN WINTER; VARIABILITY; PATTERNS; CLIMATE; EXTREMES AB Four observed El Nino-Southern Oscillation (ENSO) events are studied to determine the mechanisms responsible for the anomalous extratropical atmospheric circulation during northern winter. A parallel analysis of a GCM's response to El Nino is performed in order to assess if similar mechanisms are operative in the model atmosphere. The observed stationary wave anomalies over the Pacific/North American (PNA) region are found to be similar during the four winters despite appreciable differences in sea surface temperatures. The anomalous transient vorticity fluxes are remarkably robust over the North Pacific during each event, with an eastward extension of the climatological storm track leading to strong cyclonic forcing near 40-degrees-N, 150-degrees-W. This forcing is in phase with the seasonal mean Aleutian trough anomaly suggesting the importance of eddy-mean flow interactions. By comparison, the intersample variability of the GCM response over the PNA region is found to exceed the observed inter-El Nino variability. This stems primarily from a large variability in the model's anomalous transients over the North Pacific. Further analysis using a linear stationary wave model reveals that the extratropical vorticity transients are the primary mechanism maintaining the stationary wave anomalies over the PNA region during all four observed ENSO winters. In the case of the GCM, the organization of transient eddies is ill defined over the North Pacific, a behavior that appears more indicative of model error than the unpredictable component of seasonal mean storm track anomalies. A physical model is proposed to explain the robustness of the tropical controlling influence of the extratropical transients in nature. A simple equatorial Pacific heat source directly forces a tropical anticyclone whose phase relative to the climatological tropical anticyclone leads to an eastward extension of the subtropical jet stream. This mechanism appears to be equally effective for a heat source located either in the central or eastern Pacific basin. C1 UNIV ILLINOIS,DEPT ATMOSPHER SCI,URBANA,IL 61801. RP HOERLING, MP (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOX 449,BOULDER,CO 80309, USA. NR 36 TC 130 Z9 132 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1994 VL 7 IS 5 BP 745 EP 766 DI 10.1175/1520-0442(1994)007<0745:OOETDE>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL465 UT WOS:A1994NL46500010 ER PT J AU PHILLIPPS, PJ HELD, IM AF PHILLIPPS, PJ HELD, IM TI THE RESPONSE TO ORBITAL PERTURBATIONS IN AN ATMOSPHERIC MODEL COUPLED TO A SLAB OCEAN SO JOURNAL OF CLIMATE LA English DT Article ID CLIMATE MODEL; SENSITIVITY; CO2 AB The sensitivity of an atmospheric GCM coupled to a mixed-layer ocean to changes in orbital parameters is investigated. Three experiments are compared. One has perihelion at summer solstice and a large obliquity; another has perihelion at winter solstice and a low obliquity. The first of these is favorable for warm summers; the second for cool summers. A third experiment, with perihelion at summer solstice and the lower value of obliquity, is used to examine the relative importance of the changes in perihelion and obliquity. The eccentricity is set at 0.04 in all cases. Surface temperature responses are as large as 15-degrees-C, with the largest response over North America in summer. Changes in monsoons and Arctic sea ice are consistent with previous GCM studies. A perpetual summer version of the atmospheric model is used to investigate the positive feedback due to soil moisture. Drying of the soil over North America is found to increase the temperature response by approximately 50% and is also essential to the decrease in summertime precipitation in that region. Soil moisture changes also enhance the precipitation response over central Africa, but have little effect on the model's Asian monsoon. The orbital parameters most favorable for expansion of the Northern Hemisphere glaciers, that is, minimal seasonality, do not produce permanent snow cover. Several model deficiencies that act to accelerate the melting of snow in spring may be responsible. RP PHILLIPPS, PJ (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08544, USA. NR 22 TC 28 Z9 28 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 MAY PY 1994 VL 7 IS 5 BP 767 EP 782 DI 10.1175/1520-0442(1994)007<0767:TRTOPI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL465 UT WOS:A1994NL46500011 ER PT J AU RAVAL, A OORT, AH RAMASWAMY, V AF RAVAL, A OORT, AH RAMASWAMY, V TI OBSERVED DEPENDENCE OF OUTGOING LONGWAVE RADIATION ON SEA-SURFACE TEMPERATURE AND MOISTURE SO JOURNAL OF CLIMATE LA English DT Article ID BUDGET EXPERIMENT ERBE; CLIMATE MODELS; INFRARED RADIATION; TROPICAL OCEANS; EARTH; PARAMETERIZATION; SIMULATION; ANOMALIES; CLOUDS AB The authors have empirically examined the dependence of the outgoing longwave radiation (OLR) on sea surface temperature (T(s)), precipitable water (W), and height-mean relative humidity (RHBAR). The OLR is obtained from 4 yr of data from the Earth Radiation Budget Experiment (ERBE), while T(s), W, and RHBAR are from objective analyses of rawinsonde and ship data. It is found that in the midlatitudes, the surface temperature explains over 80% of the variability in the clear-sky OLR (F(cs)) and almost half of the variability in the total OLR (F(tot)). It fails badly in the tropics and subtropics, however, where T(s) explains only about 20% of the variability in F(cs), and is largely decoupled from F(tot). The two-dimensional contour plot of the OLR binned with respect to T(s) and RHBAR is marked by distinct changes in the gradient that are consistent with inferences from earlier investigations. For low values of T(s)(< 10-degrees-C), the OLR depends mainly on T(s). For values of T(s) above 10-degrees-C, the OLR depends increasingly on RHBAR. Specifically, in the tropics (T(s) approximately 25-degrees-C), the total and clear-sky OLR depend significantly on both T(s) and RHBAR. The well-known drop in OLR in the tropics with increasing T(s) correlates directly to an increase in RHBAR, and not to changes in T(s). The authors suggest that the observed dependence of the OLR on T(s) and RHBAR be a minimum performance standard for climate models. This approach is illustrated by comparing the observed dependence with the results of a radiative transfer model and an R15 general circulation model, and by discussing the strengths and limitations of using RHBAR to parameterize the OLR. C1 NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542. PRINCETON UNIV,AOS PROGRAM,PRINCETON,NJ 08544. NR 31 TC 39 Z9 39 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1994 VL 7 IS 5 BP 807 EP 821 DI 10.1175/1520-0442(1994)007<0807:ODOOLR>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NL465 UT WOS:A1994NL46500014 ER PT J AU SHEARER, KD ASGARD, T ANDORSDOTTIR, G AAS, GH AF SHEARER, KD ASGARD, T ANDORSDOTTIR, G AAS, GH TI WHOLE-BODY ELEMENTAL AND PROXIMATE COMPOSITION OF ATLANTIC SALMON (SALMO-SALAR) DURING THE LIFE-CYCLE SO JOURNAL OF FISH BIOLOGY LA English DT Article DE ATLANTIC SALMON; PROXIMATE COMPOSITION; ELEMENTAL COMPOSITION; LIFE CYCLE ID AMINO-ACID-REQUIREMENTS; RAINBOW-TROUT; GROWTH; MATURATION; GAIRDNERI; DIETS; ZINC; PARR; FRY C1 AGR RES COUNCIL NORWAY,INST AQUACULTURE RES,N-6600 SUNNDALSORA,NORWAY. FISHERIES LAB FAROES,TORSHAVN,DENMARK. RP SHEARER, KD (reprint author), NATL MARINE FISHERIES SERV,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. OI Hansen Aas, Grete/0000-0003-4643-4755 NR 38 TC 114 Z9 115 U1 3 U2 23 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD MAY PY 1994 VL 44 IS 5 BP 785 EP 797 DI 10.1006/jfbi.1994.1076 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA NM645 UT WOS:A1994NM64500004 ER PT J AU COFFEY, HE AF COFFEY, HE TI GEOMAGNETIC AND SOLAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material RP COFFEY, HE (reprint author), NOAA,WORLD DATA CTR SOLAR TERR PHYS A,BOULDER,CO 80302, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1994 VL 99 IS A5 BP 8789 EP 8790 DI 10.1029/94JA00968 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NK217 UT WOS:A1994NK21700025 ER PT J AU ROBINS, LH BLACK, DR AF ROBINS, LH BLACK, DR TI DEFECT MAPPING OF A SYNTHETIC DIAMOND SINGLE-CRYSTAL BY CATHODOLUMINESCENCE SPECTROSCOPY SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; OPTICAL-CENTERS; ISOTOPE SHIFTS; FILMS; LUMINESCENCE; IMPURITIES; PARTICLES; NITROGEN AB Cathodoluminescence (CL) spectroscopy in a scanning electron microscope was used to identify and to map the spatial distribution of luminescent defects in a synthetic diamond single crystal. Several defect CL bands were observed in the 1.5-3.5 eV region: (i) a band with a zero-phonon line at 2.156 eV, attributed to a center containing nitrogen and atomic vacancies; (ii) a broadband centered at approximately 2.2 eV, tentatively attributed to a boron-containing center; (iii) a doublet line at 2.33 eV, attributed to a nitrogen-containing center; (iv) a zero-phonon line at 2.555 eV, attributed to a nickel-containing center; (v) a broadband centered at approximately 2.85 eV, attributed to a dislocation-related center; and (vi) a zero-phonon line at 3.188 eV, attributed to a center containing nitrogen and a carbon interstitial. Lines due to free and acceptor-bound excitons were observed in the 5.0-5.4 eV region. The spatial variation of the CL was examined in the vicinity of regions of relatively high dislocation density (approximately 10(6) dislocations cm-2), which had been found in a previous x-ray diffraction imaging experiment. A quantitative analysis was made of the spatial variation of the band intensities. Upon moving from a relatively defect-free region to the center of a high dislocation density region, the intensities of defect bands (i) and (v) increased by very large factors (these bands were observed only within the high dislocation density regions); the intensity of defect band (vi) increased by a factor of approximately 2; the acceptor-bound exciton intensity increased by a factor of approximately 1.3; the intensities of defect bands (ii)-(iv) decreased by a factor of approximately 2; and the free exciton intensity decreased by a factor of approximately 7.5. RP ROBINS, LH (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 22 TC 6 Z9 6 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAY PY 1994 VL 9 IS 5 BP 1298 EP 1306 DI 10.1557/JMR.1994.1298 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA NH285 UT WOS:A1994NH28500031 ER PT J AU CHEN, YM RUFF, AW DALLY, JW AF CHEN, YM RUFF, AW DALLY, JW TI A HYBRID METHOD FOR DETERMINING MATERIAL PROPERTIES FROM INSTRUMENTED MICRO-INDENTATION EXPERIMENTS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SIMULATION AB The impact code EPIC was employed to study the relationship between the applied force and the penetration depth in a micrometer-scale indentation experiment with oxygen free high conductivity (OFHC) copper. EPIC is an elastic-plastic finite element code that uses a Lagrangian formulation and triangular mesh, which can accommodate large deformation without the need to remesh during the computation process. By fitting the force-penetration curves for a triangular indenter with second degree polynomials, it was demonstrated that the fit changed with two material constants in the constitutive equation. A systematic procedure for determining the material constants is described that is based on matching either the slope or the curvature of the force penetration depth curves from numerical simulation and experiments. It is concluded that material constants can be determined from indentation data obtained using pyramidal or spherical indenters as well as a flat-ended indenter. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RP UNIV MARYLAND, DEPT MECH ENGN, COLL PK, MD 20742 USA. NR 27 TC 10 Z9 10 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD MAY PY 1994 VL 9 IS 5 BP 1314 EP 1321 DI 10.1557/JMR.1994.1314 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA NH285 UT WOS:A1994NH28500033 ER PT J AU TOLMAN, HL AF TOLMAN, HL TI WIND-WAVES AND MOVEABLE-BED BOTTOM FRICTION SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CALIFORNIA CONTINENTAL-SHELF; BOUNDARY-LAYER; CURRENT FLOWS; SHEAR-STRESS; SEDIMENT; DISSIPATION; ROUGHNESS; RESUSPENSION; PREDICTIONS; DYNAMICS AB Effects of moveable-bed bottom friction for wave observations and wave modeling are investigated using a state-of-the-art bottom friction model. This model combines the hydrodynamic friction model of Madsen et al. with a moveable-bed roughness model based on Grant and Madsen. Analyzing the present model for idealized swell cases, it is shown that swell might result in wave-generated sand ripples. The large change of roughness corresponding to initial ripple formation results in a preferred wave height for swell, related to bathymetric scales as generally occur in shelf seas away from the coast. The corresponding wave-generated bottom roughness is not defined by the local wave conditions, but is related to the overall energy balance of the wave field. Sediment data thus is imperative for the interpretation of observed decay rates and friction factors for swell. For idealized depth-limited wind seas, near-bottom wave motion is expected to generate partially washed-out ripples and moderate sheet-flow roughness. A comparison with previous models explains the apparent success of several models that do not explicitly account for moveable-bed effects. Such models, however, are not expected to reproduce the above preferred wave-height concept. RP TOLMAN, HL (reprint author), NOAA, NMC,DIV DEV,MARINE PREDICT BRANCH,NMC21,ROOM 206, 5200 AUTH RD, CAMP SPRINGS, MD 20746 USA. NR 47 TC 45 Z9 45 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1994 VL 24 IS 5 BP 994 EP 1009 DI 10.1175/1520-0485(1994)024<0994:WWAMBB>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA NL324 UT WOS:A1994NL32400009 ER PT J AU PAUL, RL LINDSTROM, RM VINCENT, DH AF PAUL, RL LINDSTROM, RM VINCENT, DH TI COLD NEUTRON PROMPT GAMMA-ACTIVATION ANALYSIS AT NIST - A PROGRESS REPORT SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article AB An instrument for prompt gamma-ray activation analysis is now in operation at the NIST Cold Neutron Research Facility (CNRF). The cold neutron beam is relatively free of contamination by fast neutrons and reactor gamma rays, and the neutron fluence rate is 1.5 . 10(8) cm-2 . s-1 (thermal equivalent). As a result of a compact target-detector geometry the sensitivity is better by a factor of as much as seven than that obtained with an existing thermal instrument, and hydrogen background is a factor of 50 lower. We have applied this instrument to multielement analysis of the Allende meteorite and other materials. C1 UNIV MICHIGAN,DEPT NUCL ENGN,ANN ARBOR,MI 48109. RP PAUL, RL (reprint author), NATL INST STAND & TECHNOL,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 14 TC 19 Z9 19 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD MAY PY 1994 VL 180 IS 2 BP 263 EP 269 DI 10.1007/BF02035914 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA NQ669 UT WOS:A1994NQ66900009 ER PT J AU LINDSTROM, RM PAUL, RL VINCENT, DH GREENBERG, RR AF LINDSTROM, RM PAUL, RL VINCENT, DH GREENBERG, RR TI MEASURING HYDROGEN BY COLD-NEUTRON PROMPT-GAMMA ACTIVATION-ANALYSIS SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article ID RAY SPECTROMETRY; SCATTERING AB By irradiating with cold neutrons and avoiding hydrogenous materials of construction, we have developed a PGAA instrument at the Cold Neutron Research Facility at NIST with hydrogen detection limits in the microgram range in many materials. Quantities of 5-10 mug H/g are presently measurable in gram-sized samples of silicon or quartz, and of order 0.01 wt % can be quantitatively measured in complex silicate rocks. C1 UNIV MICHIGAN,DEPT NUCL ENGN,ANN ARBOR,MI 48109. RP LINDSTROM, RM (reprint author), NATL INST STAND & TECHNOL,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 19 TC 25 Z9 25 U1 0 U2 1 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD MAY PY 1994 VL 180 IS 2 BP 271 EP 275 DI 10.1007/BF02035915 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA NQ669 UT WOS:A1994NQ66900010 ER PT J AU LEE, KC CAGE, ME ROWE, PS AF LEE, KC CAGE, ME ROWE, PS TI SOURCES OF UNCERTAINTY IN A DVM-BASED MEASUREMENT SYSTEM FOR A QUANTIZED HALL RESISTANCE STANDARD SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE DIGITAL VOLTMETER; DVM METHOD; ELECTRICAL METROLOGY; ELECTRICAL REFERENCE STANDARDS; QUANTIZED HALL RESISTANCE; QUANTUM HALL EFFECT; RESISTANCE CALIBRATION AB Transportable 10 kOMEGA standard resistors have become fairly widespread in industrial, university, and government standards laboratories because of their low temperature coefficient of resistance, ease of transportation, and convenient value. The values of these resistors, however, tend to drift with time, requiring periodic recalibration against an invariant standard such as the quantized Hall resistance. The availability of a simple, inexpensive measurement system for calibrating 10 kOMEGA resistors against such an invariant standard would be of great benefit to primary standards laboratories. This paper decribes a simple automated measurement system that uses a single, high accuracy, commercially available digital voltmeter (DVM) to compare the voltages developed across a 10 kOMEGA standard resistor and a quantized Hall resistor when the same current is passed through the two devices. From these measurements, the value of the 10 kOMEGA standard resistor is determined. The sources of uncertainty in this system are analyzed in detail and it is shown that it is possible to perform calibrations with relative combined standard uncertainties less than 1X10(-7) (0.1 ppm). RP LEE, KC (reprint author), NATL INST STAND & TECHNOL, DIV ELECT, GAITHERSBURG, MD 20899 USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 227 EP 240 DI 10.6028/jres.099.018 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200001 ER PT J AU WU, YC KOCH, WF FENG, D HOLLAND, LA JUHASZ, E ARVAY, E TOMEK, A AF WU, YC KOCH, WF FENG, D HOLLAND, LA JUHASZ, E ARVAY, E TOMEK, A TI A DC METHOD FOR THE ABSOLUTE DETERMINATION OF CONDUCTIVITIES OF THE PRIMARY STANDARD KCL SOLUTIONS FROM 0-DEGREES-C TO 50-DEGREES-C SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ABSOLUTE MEASUREMENT; CONDUCTANCE; ELECTROLYTIC CONDUCTIVITY; POTASSIUM CHLORIDE; PRIMARY STANDARDS; RESISTANCE STANDARD ID ELECTROLYTIC CONDUCTIVITY AB A new method for the absolute determination of electrolytic conductivity based on direct current and potentiometric measurements is described. The unique design of the cell uses a removable center section whose length and cross-sectional area are accurately known. Two pairs of matched Ag, AgCl electrodes are used in a four terminal mode of resistance measurement. Measurements of the electrolytic conductivity of primary standard potassium chloride solution using this novel dc conductance cell are compared with the currently adopted IUPAC and OIML recommendations. In addition, measurements have been made of the electrolytic conductivity of a solution of potassium chloride having a molality of 1 mol/kg (mole KCl per kilogram H2O). The values so obtained over the temperature range of 0-degrees-C to 50-degrees-C arc recommended as the new primary standards for electrolytic conductivity. C1 NATL OFF MEASURE, DEPT CHEM, BUDAPEST, HUNGARY. RP WU, YC (reprint author), NATL INST STAND & TECHNOL, DIV INORGAN ANALYT RES, CHEM SCI & TECHNOL LAB, ELECTROANALYT RES GRP, GAITHERSBURG, MD 20899 USA. RI Holland, Lisa/C-2208-2011 NR 7 TC 13 Z9 13 U1 1 U2 6 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 241 EP 246 DI 10.6028/jres.099.019 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200002 ER PT J AU MISAKIAN, M FENIMORE, C AF MISAKIAN, M FENIMORE, C TI 3-AXIS COIL PROBE DIMENSIONS AND UNCERTAINTIES DURING MEASUREMENT OF MAGNETIC-FIELDS FROM APPLIANCES SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE APPLIANCE; COIL PROBE; MAGNETIC FIELD; MEASUREMENT; MEASUREMENT UNCERTAINTY; POWER FREQUENCY AB Comparisons are made between the average magnetic flux density for a three-axis circular coil probe and the flux density at the center of the probe. The results, which are determined assuming a dipole magnetic field, provide information on the uncertainty associated with measurements of magnetic fields from some electrical appliances and other electrical equipment. The present investigation extends an earlier treatment of the problem, which did not consider all orientations of the probe. A more comprehensive examination of the problem leaves unchanged the conclusions reached previously. RP MISAKIAN, M (reprint author), NATL INST STAND & TECHNOL, DIV ELECT, GAITHERSBURG, MD 20899 USA. NR 5 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 MAY-JUN PY 1994 VL 99 IS 3 BP 247 EP 253 DI 10.6028/jres.099.020 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200003 ER PT J AU WALKER, JH THOMPSON, A AF WALKER, JH THOMPSON, A TI IMPROVED AUTOMATED CURRENT CONTROL FOR STANDARD LAMPS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CONTROL; CURRENT; LAMP; IRRADIANCE; RADIANCE; RADIOMETRY; STANDARDS AB As radiometric lamp standards improve, the need to set lamp current to specific values becomes more important. Commercially available power supplies typically provide 12 bit internal digital-to-analog logic which permits current control with a relative expanded uncertainty of about 1 part in 4096, corresponding to an expanded uncertainty of the current of about 2 mA at 8 A (in this paper, expanded uncertainties are given as 2 standard deviations). For an FEL-type standard spectral irradiance lamp, this corresponds to a spectral irradiance difference of 0.12% at 655 nm. We have developed a technique using 16 bit digital-to-analog conversion which permits current control with a relative expanded uncertainty of about 1 part in 65536, corresponding to an expanded uncertainty of the current of about 0.1 mA at 8 A. This corresponds to a spectral irradiance difference of approximately 0.006% for an FEL lamp at 655 nm. We describe the technique used to achieve this improvement and we show data from a lamp demonstrating the effect of the improvement. We also describe the limitation provided by the uncertainty of the resistance of the current measuring shunt. RP WALKER, JH (reprint author), NATL INST STAND & TECHNOL, PHYS LAB, DIV RADIOMETR PHYS, GAITHERSBURG, MD 20899 USA. NR 5 TC 11 Z9 11 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 255 EP 261 DI 10.6028/jres.099.021 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200004 ER PT J AU BRUNO, TJ WOOD, MA HANSEN, BN AF BRUNO, TJ WOOD, MA HANSEN, BN TI REFRACTIVE-INDEXES OF FLUIDS RELATED TO ALTERNATIVE REFRIGERANTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ALTERNATIVE REFRIGERANTS; BROMINATED CHLORINATED ETHANES; ETHENES; ETHERS; PROPANES; PROPYNES; REFRACTIVE INDEX ID CHEMICAL-ANALYSIS; VORTEX TUBE; APPARATUS AB As part of a comprehensive program to develop suitable methods of chemical analysis for alternative refrigerants and their products, we have compiled a database of spectral, chromatographic, and physical property data that can aid in compound identification. As a small part of this effort, we have measured the refractive indices of a number of such fluids for which data were unavailable. The measurements were performed on a commercially available, digital Abbe refractometer that was modified for the relatively low temperature measurements (0-degrees-C to 20-degrees-C) that are sometimes required with these samples. RP BRUNO, TJ (reprint author), NATL INST STAND & TECHNOL, DIV THERMOPHYS, PROC SEPARAT GRP, PROFESS RES EXPERIENCE PROGRAM, BOULDER, CO 80303 USA. RI Wood, Marcelo/G-9527-2012 NR 28 TC 0 Z9 0 U1 0 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 263 EP 266 DI 10.6028/jres.099.022 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200005 ER PT J AU KESSLER, EG HENINS, A DESLATTES, RD NIELSEN, L ARIF, M AF KESSLER, EG HENINS, A DESLATTES, RD NIELSEN, L ARIF, M TI PRECISION COMPARISON OF THE LATTICE-PARAMETERS OF SILICON MONOCRYSTALS (VOL 99, PG 1, 1994) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Correction RP KESSLER, EG (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 1 TC 5 Z9 5 U1 0 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 285 EP 285 DI 10.6028/jres.099.025 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200009 ER PT J AU FELDMAN, A HOLLY, S KLEIN, CA LU, G AF FELDMAN, A HOLLY, S KLEIN, CA LU, G TI WORKSHOP ON CHARACTERIZING DIAMOND FILMS .3. GAITHERSBURG, MD, FEBRUARY 24-25, 1994) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article C1 ROCKWELL INT CORP, CANOGA PK, CA 91304 USA. CAK ANALYT, LEXINGTON, MA 02173 USA. NORTON DIAMOND FILM, NORTHBOROUGH, MA 01532 USA. RP FELDMAN, A (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 4 TC 7 Z9 7 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 1994 VL 99 IS 3 BP 287 EP 293 DI 10.6028/jres.099.026 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC262 UT WOS:A1994PC26200010 ER PT J AU SRIDHAR, N YANG, WH SROLOVITZ, DJ FULLER, ER AF SRIDHAR, N YANG, WH SROLOVITZ, DJ FULLER, ER TI MICROSTRUCTURAL MECHANICS MODEL OF ANISOTROPIC-THERMAL-EXPANSION-INDUCED MICROCRACKING SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GRAIN-SIZE; COMPUTER-SIMULATION; BRITTLE MATERIALS; CERAMICS; MICROFRACTURE; CRACKING; GROWTH AB Thermal-expansion-induced microcracking in single-phase ceramics has been simulated using a simple mechanics model based upon a regular lattice of brittle, elastic springs. Microcracks preferentially form at grain boundaries and propagate either into the bulk or along grain boundaries, depending on the toughness of the boundaries relative to the grain interiors. The present results show that anisotropic-thermal-expansion-induced microcracking can be more severe for either large or small grain size samples depending on the damage measure employed. At very small misfit strains, the large grain microstructure develops microcracks before the small grain microstructure. However, over most of the misfit strain regime examined, the total length/area of all cracks in a sample is larger when the grain size is small. This is manifested in a larger decrement of the elastic modulus in small grain size samples as compared with large grain size samples at the same misfit (DELTAT). However, large grain sizes are more detrimental with regard to fracture properties. This is because the fracture stress scales as inversely with the crack length and large grain samples exhibit larger microcracks than small grain samples. Unlike in the unconstrained samples, when a sample is constrained during a temperature excursion, the stress created by the overall thermal expansion can directly lead to fracture of the entire sample. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP SRIDHAR, N (reprint author), UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109, USA. NR 23 TC 33 Z9 34 U1 0 U2 8 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1994 VL 77 IS 5 BP 1123 EP 1138 DI 10.1111/j.1151-2916.1994.tb05384.x PG 16 WC Materials Science, Ceramics SC Materials Science GA NM655 UT WOS:A1994NM65500001 ER PT J AU XU, HHK JAHANMIR, S AF XU, HHK JAHANMIR, S TI SIMPLE TECHNIQUE FOR OBSERVING SUBSURFACE DAMAGE IN MACHINING OF CERAMICS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB A simple technique is proposed for directly observing subsurface damage in the machining of ceramics. The technique requires two polished specimens and an optical microscope with Nomarski illumination for examination. The subsurface damage created by the grinding of an alumina ceramic is investigated using this technique. The mode of damage is identified as intragrain twinning/slip, and intergranular and transgranular cracking. Chipping along the twinned planes and along the transgranular crack planes, and dislodgement of the intergranularly debonded grains are suggested to be the mechanisms of material removal in the machining of this alumina ceramic. RP XU, HHK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 82 Z9 86 U1 0 U2 14 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1994 VL 77 IS 5 BP 1388 EP 1390 DI 10.1111/j.1151-2916.1994.tb05424.x PG 3 WC Materials Science, Ceramics SC Materials Science GA NM655 UT WOS:A1994NM65500041 ER PT J AU BURNS, TJ AF BURNS, TJ TI A SIMPLE CRITERION FOR THE ONSET OF DISCONTINUOUS PLASTIC-DEFORMATION IN METALS AT VERY-LOW TEMPERATURES SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article ID COMPUTER-SIMULATION; BIFURCATION; INSTABILITY AB THE METHOD of small strain-rate-sensitivity asymptotics, which is the analogue of high-activation-energy asymptotics in the mathematical theory of combustion, is used to simplify a model of discontinuous plastic deformation in metals during tensile loading at cryogenic temperatures. The procedure is analogous to what has been used to derive the ignition problem in combustion theory. It is shown that a degenerate Poincare-Andronov-Hopf bifurcation occurs in the simplified model as a control parameter which is proportional to the applied strain rate is increased. The bifurcation point is shown to correspond closely to the onset of ''serrations'' in the load-displacement response predicted by the original model. RP BURNS, TJ (reprint author), NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899, USA. NR 31 TC 9 Z9 9 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD MAY PY 1994 VL 42 IS 5 BP 797 EP 811 DI 10.1016/0022-5096(94)90043-4 PG 15 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA NJ956 UT WOS:A1994NJ95600005 ER PT J AU XIA, HR CIRAC, JI SWARTZ, S KOHLER, B ELLIOTT, DS HALL, JL ZOLLER, P AF XIA, HR CIRAC, JI SWARTZ, S KOHLER, B ELLIOTT, DS HALL, JL ZOLLER, P TI PHASE-SHIFTS AND INTENSITY DEPENDENCE IN FREQUENCY-MODULATION SPECTROSCOPY SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID SATURATION SPECTROSCOPY AB We discuss experimental observations of an induced phase shift of the rf signal produced in frequency-modulated saturated-absorption measurements under the conditions of large probe-beam intensities. This phase shift can be understood in terms of the phase difference between the phase modulation of the optical driving field and the steady-state macroscopic polarization of the medium. We also present theoretically calculated spectra that are based on the optical Bloch equations and that are in excellent agreement with the experimental results. C1 E CHINA NORMAL UNIV,DEPT PHYS,SHANGHAI 200062,PEOPLES R CHINA. UNIV CASTILLA LA MANCHA,FAC CIENCIAS QUIM,DEPT FIS APLICADA,E-13071 CIUDAD REAL,SPAIN. UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. PURDUE UNIV,SCH ELECT ENGN,W LAFAYETTE,IN 47907. NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,WASHINGTON,DC. RP XIA, HR (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Zoller, Peter/O-1639-2014 OI Zoller, Peter/0000-0003-4014-1505 NR 14 TC 6 Z9 6 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 MAY PY 1994 VL 11 IS 5 BP 721 EP 730 DI 10.1364/JOSAB.11.000721 PG 10 WC Optics SC Optics GA NL959 UT WOS:A1994NL95900004 ER PT J AU STROSCIO, JA PIERCE, DT AF STROSCIO, JA PIERCE, DT TI GROWTH OF IRON ON IRON WHISKERS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ENERGY-ELECTRON-DIFFRACTION; MOLECULAR-BEAM EPITAXY; INTENSITY OSCILLATIONS; SCALING ANALYSIS; DIFFUSION; DEPOSITION; GAAS; SURFACES; SI(001); ORIGIN AB Real space views of the homoepitaxial growth of Fe on Fe(001) whiskers is reported, observed by scanning tunneling microscopy (STM), during the initial stages of growth. Scaling of the Fe island sizes and separation distributions are observed as a function of the diffusion rate to the deposition rate. A measure of the surface diffusion of the Fe atoms is obtained over the temperature range of 20-250-degrees-C from the temperature dependence of the island density. The effect of the diffusion kinetics is also observed in the surface morphology as a decrease in surface roughness with increasing temperature in thin Fe films. A comparison of real and reciprocal space techniques is obtained from a comparison of STM images and reflection-high-energy-electron-diffraction measurements during growth. RP NATL INST STAND & TECHNOL, ELECTRON PHYS GRP, GAITHERSBURG, MD 20899 USA. NR 20 TC 29 Z9 29 U1 0 U2 3 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1994 VL 12 IS 3 BP 1783 EP 1788 DI 10.1116/1.587599 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA NR918 UT WOS:A1994NR91800102 ER PT J AU STROSCIO, JA PIERCE, DT UNGURIS, J CELOTTA, RJ AF STROSCIO, JA PIERCE, DT UNGURIS, J CELOTTA, RJ TI SCANNING-TUNNELING-MICROSCOPY STUDY OF THE GROWTH OF CR-FE(001) - CORRELATION WITH EXCHANGE COUPLING OF MAGNETIC LAYERS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID SURFACE; MAGNETORESISTANCE; DIFFUSION; SI(001); ENERGY; SI AB Scanning tunneling microscopy (STM) and reflection high-energy electron diffraction (RHEED) were used to study the epitaxial growth of Cr on Fe(001) whiskers as a function of the Fe whisker temperature during growth. The STM images give real space views of the morphology of Cr growth, which can be correlated with the nature of the RHEED intensity oscillations. Layer by layer growth is found for Cr deposition on an Fe(001) surface at 300-degrees-C, and very rough growth, limited by diffusion kinetics, is observed at lower temperatures. The variation in the interlayer exchange coupling in Fe/Cr/Fe sandwiches as a function of the thickness of the Cr interlayer, which has been found to depend strongly on the growth temperature of the Cr interlayer, can be explained by the thickness fluctuations determined from the STM measurements of Cr films gown at different temperatures. RP STROSCIO, JA (reprint author), NATL INST STAND & TECHNOL, ELECTRON PHYS GRP, GAITHERSBURG, MD 20899 USA. RI Unguris, John/J-3989-2014 NR 13 TC 20 Z9 20 U1 0 U2 5 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1994 VL 12 IS 3 BP 1789 EP 1792 DI 10.1116/1.587600 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA NR918 UT WOS:A1994NR91800103 ER PT J AU SCHOLTEN, RE MCCLELLAND, JJ PALM, EC GAVRIN, A CELOTTA, RJ AF SCHOLTEN, RE MCCLELLAND, JJ PALM, EC GAVRIN, A CELOTTA, RJ TI NANOSTRUCTURE FABRICATION VIA DIRECT WRITING WITH ATOMS FOCUSED IN LASER FIELDS SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 1993 International Conference on Scanning Tunneling Microscopy (STM 93) CY AUG 09-13, 1993 CL BEIJING, PEOPLES R CHINA SP CHINESE ACAD SCI, INST CHEM, STATE SCI & TECHNOL COMMISS, CHINA ASSOC SCI & TECHNOL, NATL NAT SCI FDN CHINA, MINIST PERSONNEL BEIJING, STATE EDUC COMMISS, AMER VACUUM SOC, AVS NANOMETER SCALE SCI & TECHNOL DIV, SONY CORP RES CTR, ULVAC CORP, NIPPON STEEL, TOSHIBA R&D CTR, MATSUSHITA ELECT IND CO, SURFACE SCI RES FDN ID RESONANCE-RADIATION PRESSURE; BEAM; LIGHT AB The techniques of atom optics can be applied during the deposition of atoms onto a surface to produce nanostructures. A laser is used to form a standing wave intensity pattern in front of the substrate. An atom beam, which has been collimated by optical means, is focused onto the substrate by dipole forces from the standing wave pattern so as to deposit a series of lines spaced by half the laser wavelength. We describe the fabrication of a Cr nanograting formed using this new technique. The experimental arrangement for deposition and the optical collimation of the atom beam are described. Scanning electron microscopy (SEM) and atomic force microscopy (AFM)images of the resulting nanostructures are presented. RP SCHOLTEN, RE (reprint author), NATL INST STAND & TECHNOL,ELECTRON,GAITHERSBURG,MD 20899, USA. RI Scholten, Robert/A-8586-2013; McClelland, Jabez/A-2358-2015 OI Scholten, Robert/0000-0002-2337-8036; McClelland, Jabez/0000-0001-5672-5965 NR 13 TC 18 Z9 19 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1994 VL 12 IS 3 BP 1847 EP 1850 DI 10.1116/1.587653 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA NR918 UT WOS:A1994NR91800117 ER PT J AU ARMSTRONG, RA AF ARMSTRONG, RA TI GRAZING LIMITATION AND NUTRIENT LIMITATION IN MARINE ECOSYSTEMS - STEADY-STATE SOLUTIONS OF AN ECOSYSTEM MODEL WITH MULTIPLE FOOD-CHAINS SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID GRAPHICAL APPROACH; IRON LIMITATION; PHYTOPLANKTON; PLANKTON; DYNAMICS; PACIFIC; PRODUCTIVITY; CHEMOSTAT; PREDATION; AMMONIUM AB Here I develop a model with multiple phytoplankton-zooplankton food chains where each food chain is based on a different size class of algae. Model parameters were chosen to allow food chains based on smaller algal size classes to dominate under oligotrophic conditions, with larger size classes being added sequentially with increased nutrient loading. The model makes use of allometric relations among size classes to minimize the number of free parameters, facilitating numerical exploration of its steady state behavior. The model is simple, yet it is complex enough to allow simultaneous predator limitation of algal size classes (or species) and nutrient limitation of total phytoplankton biomass. This perspective, not obtainable from models with single phytoplankton and zooplankton size classes, is applied to the particular case of elevated nitrate levels in the equatorial Pacific. The model shows clearly that it is possible for each phytoplankton size class to be limited by its herbivores, while at the same time micronutrient (notably iron) deficiency may limit the number of size classes that can exist in the community and hence the total phytoplankton biomass that can be supported. RP ARMSTRONG, RA (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,SAYRE HALL,POB CN710,PRINCETON,NJ 08544, USA. RI Armstrong, Robert/C-9086-2009 NR 38 TC 119 Z9 121 U1 2 U2 16 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 MAY PY 1994 VL 39 IS 3 BP 597 EP 608 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA NT264 UT WOS:A1994NT26400011 ER PT J AU KERFOOT, WC LAUSTER, G ROBBINS, JA AF KERFOOT, WC LAUSTER, G ROBBINS, JA TI PALEOLIMNOLOGICAL STUDY OF COPPER MINING AROUND LAKE-SUPERIOR - ARTIFICIAL VARVES FROM PORTAGE LAKE PROVIDE A HIGH-RESOLUTION RECORD SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SEDIMENTS; MICHIGAN; CHEMISTRY; TOXICITY; RATES AB On the Keweenaw Peninsula region of Lake Superior, approximately 0.5 Gt of copper mine tailings were dumped along rivers, lakes, and connecting waterways between 1850 and 1968-an era of active copper and silver mining. In the low-energy environment of Portage Lake, a part of the Keweenaw Waterway, clay particles from stamp sand discharges created artificially varved lake sediments that preserved a remarkably detailed record. Measurements of these varves, in conjunction with radiodating techniques, allow precise determinations of deposition rates, sediment, and Cu fluxes. Concentration and flux profiles produce fundamentally different patterns. Copper concentrations have remained high in sediments despite complete cessation of active tailings discharge. However, densitometer scans of X-rayed cores and flux calculations at sites closest to sluicing locations reveal a good correspondence with the historic record of stamp sand production. Sedimentation rates and Cu fluxes have declined steadily since cessation of native copper mining, although elevated Cu levels continue to circulate in the ecosystem. Comparisons of Cu profiles from sediment cores across eastern Lake Superior suggest wide-spread signatures of mining and major contribution to sediments. C1 MICHIGAN TECHNOL UNIV, DEPT BIOL SCI, HOUGHTON, MI 49931 USA. NOAA, GREAT LAKES ENVIRONM RES LAB, ANN ARBOR, MI 48105 USA. RP KERFOOT, WC (reprint author), MICHIGAN TECHNOL UNIV, LAKE SUPER ECOSYST RES CTR, HOUGHTON, MI 49931 USA. NR 29 TC 31 Z9 31 U1 2 U2 16 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0024-3590 EI 1939-5590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAY PY 1994 VL 39 IS 3 BP 649 EP 669 PG 21 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA NT264 UT WOS:A1994NT26400014 ER PT J AU ROSEL, PE DIZON, AE HEYNING, JE AF ROSEL, PE DIZON, AE HEYNING, JE TI GENETIC-ANALYSIS OF SYMPATRIC MORPHOTYPES OF COMMON DOLPHINS (GENUS DELPHINUS) SO MARINE BIOLOGY LA English DT Article ID EVOLUTION; POPULATIONS; STENELLA AB Sympatric populations of two forms of the common dolphin, currently recognized collectively as Delphinus delphis Linnaeus, occur in several areas of the world's oceans. A molecular genetic study was initiated to determine whether these forms are genetically distinct in the Northeast Pacific. We compared mitochondrial DNA sequences from the control region and cytochrome b gene between specimens of the long-beaked and the short-beaked morphotypes collected between 1986 and 1989 off the coast of southern California. Additional short-beaked specimens collected from the eastern tropical Pacific (in 1978 and 1982) and the Black Sea (in 1989) were also compared. There were no shared mitochondrial DNA haplotypes between the two morphotypes, and both gene regions exhibited frequency and fixed nucleotide substitutions between the two morphotypes. This genetic differentiation, coupled with unique morphological characters of the short-beaked and long-beaked morphotypes determined in a parallel study, indicate that although sympatric, these populations of common dolphin are reproductively isolated from one another and may represent separate species. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. SW FISHERIES SCI CTR,LA JOLLA,CA 92038. NAT HIST MUSEUM LOS ANGELES,BIRDS & MAMMALS SECT,LOS ANGELES,CA 90007. NR 27 TC 136 Z9 150 U1 1 U2 12 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD MAY PY 1994 VL 119 IS 2 BP 159 EP 167 DI 10.1007/BF00349552 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA NP599 UT WOS:A1994NP59900001 ER PT J AU BELL, GD BOSART, LF AF BELL, GD BOSART, LF TI MIDTROPOSPHERIC CLOSED CYCLONE FORMATION OVER THE SOUTHWESTERN UNITED-STATES, THE EASTERN UNITED-STATES, AND THE ALPS SO MONTHLY WEATHER REVIEW LA English DT Article ID LEE CYCLOGENESIS; BAROCLINIC WAVES; DEEP CYCLOGENESIS; DYNAMICS; CLIMATOLOGY; INSTABILITY AB Observational composites of midtropospheric closed cyclone formation arc constructed and diagnosed for three regions: the southwestern United States, the eastern United States, and the southern lee of the Alps. The spatial scales upon which closed cyclone formation occurs are then examined by zonally decomposing the composite 500-hPa height fields into three distinct wave groups: the planetary scale (zonal waves 1-3), the large synoptic scale (zonal waves 4-9), and the small synoptic scale (zonal waves 10-25). This analysis leads to a description of closed cyclogenesis as a combined wave interaction and wave superposition process involving both wave groups 4-9 and 10-25, which is intimately linked to preexisting along-stream speed variations and flow curvature. This description is inconsistent with modal and nonmodal analytical instability theories of cyclogenesis. The essence of the closed cyclogenesis process is contained in the relative positioning of, and interaction between, preexisting jets and waves. In all regions the precursor wave pattern is characterized by a broad trough over the impending cyclone region, with the strongest meridional flow and implied geostrophic vorticity MaXimum located upstream of this trough axis. This flow configuration is associated with sustained cyclonic vorticity advection into the amplifying trough axis, and also provides a conduit by which intensifying transient short-wave trough-jet streak features can propagate into the downstream trough. A closed circulation then develops as the geostrophic wind spect maximum moves into the base of the trough and cyclonic vorticity becomes concentrated within the trough axis. This evolution also occurs coincident with the movement of the transient trough feature directly into the amplifying long-wave trough axis. In the southwestern United States and Alps cases, the favorable northwesterly flow configuration is initiated two days prior to closed cyclone formation by vigorous upstream wave amplification and by the rapid eastward movement of the upstream ridge axis relative to the downstream trough axis. Downstream of the cyclogenesis region, relatively modest anticyclogenesis, and modest mid- and lower-tropospheric thermal advection, is observed in these cases. In contrast, the favorable northwesterly flow configuration in the eastern United States cases is already established two days prior to closed cyclone formation. These cases are also characterized by vigorous downstream planetary-scale ridge amplification and a well-defined pattern of mid- and lower-tropospheric thermal advection. C1 SUNY ALBANY, DEPT ATMOSPHER SCI, ALBANY, NY 12222 USA. NOAA, NWS, NMC, CTR CLIMATE ANAL, WASHINGTON, DC 20230 USA. NR 31 TC 10 Z9 10 U1 0 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 MAY PY 1994 VL 122 IS 5 BP 791 EP 813 DI 10.1175/1520-0493(1994)122<0791:MCCFOT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NJ570 UT WOS:A1994NJ57000003 ER PT J AU LEE, JL BROWNING, GL AF LEE, JL BROWNING, GL TI ANALYSIS OF ERRORS IN THE HORIZONTAL DIVERGENCE DERIVED FROM HIGH TEMPORAL RESOLUTION OF THE WIND SO MONTHLY WEATHER REVIEW LA English DT Article ID INITIALIZATION AB The vorticity method is applied to determine horizontal divergence using the dynamical balance of terms in the vorticity equation. The viability of the method is analyzed in terms of dynamical approximations, sensitivity to observation and truncation errors, and numerical experiments. This analysis is also applied to the kinematic method, which calculates the horizontal divergence by adding together the appropriate finite-difference approximations of its individual terms. The analysis of errors in the vorticity and kinematic methods is based on the accuracy of the data. It is proven analytically that errors in the divergence derived from the vorticity method are smaller than those of the kinematic method by a factor equal to the Rossby number, even though the former method involves higher-order derivatives. When a 10% random error is included, the error of the large-scale divergence in the kinematic method exceeds 100%, whereas the error derived by the vorticity method is less than 30% and is comparable to the error in the horizontal wind as expected from the error analysis. An essential result is that the temporal variation of the vorticity is not adequately resolved by the 12-h rawinsonde observing systems and must instead be derived from high temporal resolution wind data such as those measured by the Wind Profiler Demonstration Network. Due to the unavailability of the profiler data in the planetary boundary layer, the vorticity method is primarily applicable to the free atmosphere. RP LEE, JL (reprint author), NOAA,ERL,FORECAST SYST LAB,MAIL CODE REFS,325 BROADWAY,BOULDER,CO 80303, USA. RI Lee, JIN-LUEN/G-5364-2015 NR 25 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1994 VL 122 IS 5 BP 851 EP 863 DI 10.1175/1520-0493(1994)122<0851:AOEITH>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NJ570 UT WOS:A1994NJ57000006 ER PT J AU FRANZREB, K FINE, J AF FRANZREB, K FINE, J TI MEASUREMENT OF EMISSION-ANGLE-RESOLVED TIME-OF-FLIGHT DISTRIBUTIONS OF SPUTTERED MG+ IONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 15th International Conference on Atomic Collisions in Solids (ICACS-15) CY JUL 26-30, 1993 CL UNIV W ONTARIO, LONDON, CANADA HO UNIV W ONTARIO ID INELASTIC PROCESSES; SURFACE COLLISIONS; PHOTON-EMISSION; AR+ COLLISIONS; TOF-SARS; MAGNESIUM; SCATTERING; FRACTIONS; NE+; CHEMISORPTION AB We describe an experiment designed to perform emission-angle-resolved time-of-flight (TOF) analysis of sputter-ejected secondary ions as well as of laser-postionized sputtered neutral particles. The apparatus includes a rotatable linear TOF mass spectrometer and an electron-cyclotron-resonance (ECR) plasma ion source for the bombardment of the target with a mass-filtered Ar+ ion beam pulse in the keV energy region (ion pulse width about 30 ns). We present emission-angle-resolved time-of-flight spectra of Mg+ secondary ions sputter-ejected from a polycrystalline Mg-24 target bombarded at 45-degrees incidence. These TOF spectra also contain additional information on the emission-angle dependence of high energy argon projectiles scattered from the target surface. RP FRANZREB, K (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE & MICROANAL SCI,GAITHERSBURG,MD 20899, USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1994 VL 90 IS 1-4 BP 513 EP 517 DI 10.1016/0168-583X(94)95605-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NM766 UT WOS:A1994NM76600107 ER PT J AU CHEN, H MILDNER, DFR DOWNING, RG BENENSON, RE XIAO, QF SHAROV, VA AF CHEN, H MILDNER, DFR DOWNING, RG BENENSON, RE XIAO, QF SHAROV, VA TI NEUTRON FOCUSING USING CAPILLARY OPTICS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 3rd European Conference on Accelerators in Applied Research and Technology (ECAART-3) CY AUG 31-SEP 04, 1993 CL ORLEANS, FRANCE SP CNRS, DIRECT RECH & ETUDE TECH, SECRETARIAT GEN DEF NATL, CONSEIL REG CTR, CONSEIL GEN LOIRET, MAIRIE D ORLEANS ID PIPE AB Using the principle of multiple mirror reflection from smooth surfaces at small grazing angles, polycapillary fibers of narrow inner channels (diameter of a few micrometers) have been used to transport and bend slow neutron beams. Neutrons in the cold and thermal range have been focused to a small spot to produce significant gains (approximately x 10) in intensity. We report studies of neutron transmission properties of individual capillaries, using cold and thermal neutrons at the CNRF (Cold Neutron Research Facility) of the NBSR (the 20 MW research reactor at the National Institute of Standards and Technology, USA). Several aspects of these properties are investigated, namely, the transmission as a function of bending curvature, of length of the fibers, and of composition of fiber materials. From these studies we obtain information on the critical angle of reflection, the reflectivity, and the roughness of the inner surface. We also report the characterization of the first prototype neutron lens constructed at the Kurchatov Institute in Moscow and show that a focal point of 1 mm has been achieved. Finally we discuss the design of a lens suitable for neutron absorption experiments at the end of a neutron guide. C1 XRAY OPT SYST,ALBANY,NY 12222. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. RP CHEN, H (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 26 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1994 VL 89 IS 1-4 BP 401 EP 411 DI 10.1016/0168-583X(94)95208-6 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NL001 UT WOS:A1994NL00100077 ER PT J AU MILLER, MA SLABACK, LA AF MILLER, MA SLABACK, LA TI COMPUTER-BASED TRAINING AT A RESEARCH REACTOR SO NUCLEAR PLANT JOURNAL LA English DT Article RP MILLER, MA (reprint author), NATL INST STAND & TECHNOL,RADP C125,GAITHERSBURG,MD 20899, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU EQES INC PI GLEN ELLYN PA 799 ROOSEVELT RD, BUILDING 6, STE 208, GLEN ELLYN, IL 60137-5925 SN 0892-2055 J9 NUCL PLANT J JI Nucl. Plant J. PD MAY-JUN PY 1994 VL 12 IS 3 BP 33 EP & PG 0 WC Energy & Fuels; Nuclear Science & Technology SC Energy & Fuels; Nuclear Science & Technology GA NR432 UT WOS:A1994NR43200001 ER PT J AU TRAIL, WK MORRISON, MA ZHOU, HL WHITTEN, BL BARTSCHAT, K MACADAM, KB GOFORTH, TL NORCROSS, DW AF TRAIL, WK MORRISON, MA ZHOU, HL WHITTEN, BL BARTSCHAT, K MACADAM, KB GOFORTH, TL NORCROSS, DW TI LOW-ENERGY-ELECTRON COLLISIONS WITH SODIUM - ELASTIC AND INELASIC SCATTERING FROM THE GROUND-STATE SO PHYSICAL REVIEW A LA English DT Review ID LASER-EXCITED ATOMS; R-MATRIX METHOD; DIFFERENTIAL CROSS-SECTIONS; SPIN-POLARIZED ELECTRONS; IMPACT EXCITATION; SUPERELASTIC SCATTERING; GENERAL PROGRAM; OPTICAL METHOD; NA(3P); ORIENTATION AB The electron-Na system is the prototype for nonrelalivistic scattering of a charged particle from a quasi-one-electron system, At scattering energies below several eV, e-Na cross sections are particularly sensitive to the exchange interaction and manifest a rich variety of near-threshold structures in various spin channels. By applying the nonperturbative coupled-channel R-matrix method in carefully converged calculations we have generated a comprehensive data base of accurate scattering quantities for studying these phenomena and for comparison to present and future experimental data. In particular, we examine elastic scattering and excitation of the 3p, 4s, 3d, and 4p excited states at energies from threshold to 8.6 eV. In addition to conventional integrated and differential cross sections, we consider partial cross sections for changes in the projection of the spin and orbital angular momentum of the Na valence electron, comparing results for all these quantities to experimental data where available. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV OKLAHOMA,DEPT PHYS & ASTRON,NORMAN,OK 73019. COLORADO COLL,DEPT PHYS,COLORADO SPRINGS,CO 80903. DRAKE UNIV,DEPT PHYS & ASTRON,DES MOINES,IA 50311. UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506. SW OKLAHOMA STATE UNIV,DEPT PHYS,WEATHERFORD,OK 73096. RP TRAIL, WK (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Bartschat, Klaus/I-2527-2012 NR 117 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1994 VL 49 IS 5 BP 3620 EP 3645 DI 10.1103/PhysRevA.49.3620 PN A PG 26 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NL385 UT WOS:A1994NL38500058 ER PT J AU WEIMER, CS BOLLINGER, JJ MOORE, FL WINELAND, DJ AF WEIMER, CS BOLLINGER, JJ MOORE, FL WINELAND, DJ TI ELECTROSTATIC MODES AS A DIAGNOSTIC IN PENNING-TRAP EXPERIMENTS SO PHYSICAL REVIEW A LA English DT Article ID NONNEUTRAL ION PLASMA; CYCLOTRON-RESONANCE; PHASE-TRANSITION; TRANSPORT; EQUILIBRIUM; RESOLUTION; RADIATION; CRYSTAL; COLUMN; LIQUID AB A subset of the electrostatic modes of a cold cloud of electrons, a non-neutral electron plasma, trapped in a Penning trap has been observed and identified using a recent theoretical model. The detection of these modes is accomplished using electronic techniques which could apply to any ion species. The modes are observed in the low-density, low-rotation limit of the cloud where the cloud approaches a two-dimensional charged disk. We observe both axially symmetric and asymmetric drumhead modes. The shape, rotation frequency, and density of the cloud are found in a real-time nondestructive manner by measuring the frequency of these modes. In addition, it is found that radio-frequency sideband cooling compresses the cloud, increasing its density. The ability to measure and control the density of a trapped ion cloud might be useful for experiments on low-temperature ion-neutral-atom collisions, recombination rates, and studies of the confinement properties of non-neutral plasmas. RP WEIMER, CS (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 70 TC 51 Z9 51 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1994 VL 49 IS 5 BP 3842 EP 3853 DI 10.1103/PhysRevA.49.3842 PN B PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NL386 UT WOS:A1994NL38600005 ER PT J AU JULIENNE, PS SUOMINEN, KA BAND, Y AF JULIENNE, PS SUOMINEN, KA BAND, Y TI COMPLEX-POTENTIAL MODEL OF COLLISIONS OF LASER-COOLED ATOMS SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM DEFECT ANALYSIS; DIATOMIC-MOLECULES; ULTRACOLD SODIUM; OPTICAL TRAPS; PHOTOASSOCIATION; STATE; HALF; SPECTROSCOPY; SCATTERING; LOSSES AB We apply a fully-quantum-mechanical complex-potential model to calculate the S matrix to test the validity of semiclassical methods for describing collisions of ground and excited laser-cooled Cs, Na, or Li atoms in a magneto-optical trap (MOT). The model includes the, role of bound-state resonances in closed channels when the collision energy is smaller than the detuning from the atomic cooling transition. The model also illustrates the factorization of the S matrix into inner and outer parts, as used in simpler semiclassical theories. Our fully quantum results agree with other calculations that demonstrate much smaller rate coefficients for Cs collisions at low temperature than predicted by a semiclassical optical-Bloch-equation treatment. We show that an even simpler semiclassical Landau-Zener model accurately describes the S matrix at MOT temperatures and below for a weak laser intensity. There is no evidence for any significant contribution from the off-resonant excitation that is prominent in local-equilibrium models. The effect of excited-state spontaneous decay during the collision is much less for the light species Li than for the heavy species Cs. Semiclassical models still work well for Li. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. BEN GURION UNIV NEGEV,DEPT PHYS,IL-84105 BEER SHEVA,ISRAEL. BEN GURION UNIV NEGEV,DEPT CHEM,IL-84105 BEER SHEVA,ISRAEL. RP JULIENNE, PS (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 36 TC 28 Z9 28 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1994 VL 49 IS 5 BP 3890 EP 3896 DI 10.1103/PhysRevA.49.3890 PN B PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NL386 UT WOS:A1994NL38600010 ER PT J AU SUOMINEN, KA HOLLAND, MJ BURNETT, K JULIENNE, PS AF SUOMINEN, KA HOLLAND, MJ BURNETT, K JULIENNE, PS TI EXCITED-STATE SURVIVAL PROBABILITIES FOR COLD COLLISIONS IN A WEAK LASER FIELD SO PHYSICAL REVIEW A LA English DT Article ID LEVEL-CROSSINGS; OPTICAL TRAPS; WAVE AB We show that in the cold collisions between laser-cooled and trapped atoms the probability to survive in the excited state during the collision can be obtained, in the weak-field limit, from a simple Landau-Zener approach. This is shown by comparing the method with a fully quantum and time-dependent wave-packet treatment. We also show that the optical Bloch equation method is not the proper semiclassical tool to use at low energies, at least in its present form. The unexpectedly low quantum survival probability reported by Boesten et al. [Phys. Rev. A 48, 1428 (1993)] is in fact predicted by the semiclassical Landau-Zener approach. This in turn shows that off-resonant excitation is not important in the low-energy regime. C1 NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP SUOMINEN, KA (reprint author), UNIV OXFORD,DEPT PHYS,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 11 TC 27 Z9 27 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 MAY PY 1994 VL 49 IS 5 BP 3897 EP 3902 DI 10.1103/PhysRevA.49.3897 PN B PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NL386 UT WOS:A1994NL38600011 ER PT J AU CIRAC, JI BLATT, R ZOLLER, P AF CIRAC, JI BLATT, R ZOLLER, P TI NONCLASSICAL STATES OF MOTION IN A 3-DIMENSIONAL ION-TRAP BY ADIABATIC PASSAGE SO PHYSICAL REVIEW A LA English DT Note ID COLD CESIUM ATOMS; QUANTIZED MOTION; LASER AB A scheme for the preparation of nonclassical states of motion in a three-dimensional harmonic ion trap is proposed. The technique is based on adiabatic passage along dressed energy levels of the strongly coupled ion-trap system by varying the laser frequency. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV CASTILLA LA MANCHA,FAC CIENCIAS QUIM,DEPT FIS APLICADA,E-13071 CIUDAD REAL,SPAIN. INST LASER PHYS,D-20355 HAMBURG 36,GERMANY. RP CIRAC, JI (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Zoller, Peter/O-1639-2014 OI Zoller, Peter/0000-0003-4014-1505 NR 14 TC 73 Z9 74 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 MAY PY 1994 VL 49 IS 5 BP R3174 EP R3177 PN A PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NL385 UT WOS:A1994NL38500009 ER PT J AU HIROTA, K SHIRANE, G GEHRING, PM MAJKRZAK, CF AF HIROTA, K SHIRANE, G GEHRING, PM MAJKRZAK, CF TI NEUTRON-SCATTERING STUDIES OF THE 2 MAGNETIC CORRELATION LENGTHS IN TERBIUM SO PHYSICAL REVIEW B LA English DT Article ID CRITICAL FLUCTUATIONS; SRTIO3; SCALES; PHASE; TB AB Extensive neutron-scattering experiments have been performed in order to characterized the nature of the two correlation lengths observed in Tb, a phenomenon common to Ho as well as SrTiO3. In the vicinity of the transition temperature, each of those crystals exhibits an anomalous two-component q profile in the critical scattering; the usual broad peak and an unexpected additional narrow peak. In order to clarify the spatial origin of the narrow component, the (0, 0, delta) magnetic satellite peak of Tb has been closely examined using a very narrow neutron beam realized by a high spatial resolution reflectometer at the National Institute of Standards and Technology, which can produce well-defined beam widths of 0.3 mm and less. The small scattering angle (theta almost-equal-to 1.35-degrees) and the narrow beam width result in an extraordinarily fine q and E resolution. As recently reported, we have confirmed that the intensity of the narrow component is enhanced near the edge of the crystal; it demonstrates that the major part is located within the near surface volume or ''skin'' of the crystal. A skin thickness of approximately 0.2 mm full width at half maximum (FWHM) is obtained by fitting the results to a model scatterer distribution which convolutes the beam profile. In contrast to the case of the central peak observed in SrTiO3, this unusual spatial distribution establishes the narrow component as a distinct entity in the critical fluctuations. We have shown that the narrow component possesses a different temperature dependence of delta from that of the broad one. Moreover, high E resolution scans show that the narrow component has a distinct energy width which is smaller than our resolution limit (approximately 2 mueV FWHM), and that it is essentially temperature independent. We believe that this quasistatic character of the narrow component is the important key to understanding its physical origin. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP HIROTA, K (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Hirota, Kazuma/C-6797-2008; OI Gehring, Peter/0000-0002-9236-2046 NR 22 TC 52 Z9 52 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 MAY 1 PY 1994 VL 49 IS 17 BP 11967 EP 11978 DI 10.1103/PhysRevB.49.11967 PG 12 WC Physics, Condensed Matter SC Physics GA NL643 UT WOS:A1994NL64300048 ER PT J AU HSIEH, WT CHANG, KJ LI, WH LEE, KC LYNN, JW LAI, CC KU, HC AF HSIEH, WT CHANG, KJ LI, WH LEE, KC LYNN, JW LAI, CC KU, HC TI MAGNETIC-ORDERING OF PR AND CU IN TLBA2PRCU2O7-Y SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-STRUCTURE; SUPERCONDUCTIVITY; Y1-XPRXBA2CU3O7; FLUCTUATIONS; PRBA2CU3O7-Y; TLBA2YCU2O7; RBA2CU3O6+X; ERBA2CU3O7; BEHAVIOR AB Neutron-scattering measurements have been performed to study the magnetic ordering of Pr and Cu in semiconducting TlBa2PrCu2O7-y. This compound has a nuclear structure which is similar to that of YBa2Cu3O7 but with the CuO-chain layers fully replaced by TlO layers. At low temperatures the magnetic diffraction pattern reveals magnetic Bragg peaks of the {1/2 1/2 1/2} type, which are associated with the antiferromagnetic ordering of the Pr moments. The magnetic structure consists of nearest-neighbor spins along all three crystallographic directions being antiparallel. The spin direction is along the c axis, with a saturated moment of 1.05 mu(B). The temperature dependence of the intensity of these reflections indicates a Neel temperature T(N) almost-equal-to 8 K, which is about half that observed in the related PrBa2Cu3O7 system. A second set of magnetic reflections, of the {1/2 1/2 1} type, are also observed, and these are associated with the Cu magnetic sublattice. This magnetic structure is identical to the ''plane ordering'' observed in the related 1:2:3 system, where the nearest-neighbor Cu spins are again antiparallel. The spin direction is in the tetragonal ab plane, with a saturated ordered moment of 0.59 mu(B). The temperature dependence indicates a Neel temperature of almost-equal-to 370 K for the Cu spins. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. NATL CHIAO TUNG UNIV,INST ELECTR,HSINCHU 30043,TAIWAN. NATL TSING HUA UNIV,DEPT PHYS,HSINCHU 30043,TAIWAN. RP HSIEH, WT (reprint author), NATL CENT UNIV,DEPT PHYS,CHUNGLI 32054,TAIWAN. NR 26 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1994 VL 49 IS 17 BP 12200 EP 12205 DI 10.1103/PhysRevB.49.12200 PG 6 WC Physics, Condensed Matter SC Physics GA NL643 UT WOS:A1994NL64300076 ER PT J AU MCGHIE, AR FISCHER, JE HEINEY, PA STEPHENS, PW CAPPELLETTI, RL NEUMANN, DA MUELLER, WH MOHN, H TERMEER, HU AF MCGHIE, AR FISCHER, JE HEINEY, PA STEPHENS, PW CAPPELLETTI, RL NEUMANN, DA MUELLER, WH MOHN, H TERMEER, HU TI PHASE-TRANSITIONS IN SOLID C70 - SUPERCOOLING, METASTABLE PHASES, AND IMPURITY EFFECT SO PHYSICAL REVIEW B LA English DT Article ID ORDERING TRANSITION; C-70 CRYSTALS; DYNAMICS; C-60 AB Modulated differential scanning calorimetry of sublimed C70 shows clear evidence for four first-order transitions, two strong and two weak, which we associate with the two different molecular rotational degrees of freedom in majority (equilibrium) and minority (metastable) phases. The latter correspond to two different stacking sequences of close-packed layers, and their relative contributions to the thermal data correlate well with high-temperature x-ray powder-diffraction results. The upper (long axis tumbling) transition in the majority phase exhibits 50 K supercooling when scanned at 2 K/min. C60 impurities at the few % level depress the transition temperatures substantially. C1 UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. OHIO UNIV,DEPT PHYS & ASTRON,ATHENS,OH 45701. HOECHST AG,CENT RES,D-65926 FRANKFURT,GERMANY. RP MCGHIE, AR (reprint author), UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104, USA. NR 19 TC 61 Z9 61 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1994 VL 49 IS 18 BP 12614 EP 12618 DI 10.1103/PhysRevB.49.12614 PG 5 WC Physics, Condensed Matter SC Physics GA NM433 UT WOS:A1994NM43300023 ER PT J AU BRAUN, RJ MCFADDEN, GB CORIELL, SR AF BRAUN, RJ MCFADDEN, GB CORIELL, SR TI MORPHOLOGICAL INSTABILITY IN PHASE-FIELD MODELS OF SOLIDIFICATION SO PHYSICAL REVIEW E LA English DT Article ID DISALLOWED CRYSTAL-GROWTH; CRITICAL-BEHAVIOR; INTERFACE; DIFFUSION; PLANAR; COMPUTATION; TRANSITIONS; STABILITY; KINETICS AB We analyze the linear stability of a planar solidification front with sharp-interface and phase-field models in two physical situations: (1) an isothermal system at the melting point in the unperturbed state, and (2) constant-speed growth of a crystal into its hypercooled melt. The parameters in the phase-field models are chosen to scale with the nondimensional interface thickness so that in the limit of vanishing interface thickness, the sharp-interface model is recovered. Comparison of the results from the two models shows the following trends as the interface between the melt and solid is made thicker. (1) Perturbations to the plane front are stabilized as if the surface energy of the interface was increased. (2) The planar front and its perturbations behave as if the interfacial attachment kinetics was made faster, as long as the interface is significantly smaller than the capillary length. If the interface thickness is on the order of the capillary length, then the attachment kinetics may appear either slower or faster than for sharp-interface models. Stability results under ''heat trapping'' conditions are computed, and only planar fronts whose speed increases with undercooling are found to be stable. RP BRAUN, RJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 49 TC 36 Z9 37 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1994 VL 49 IS 5 BP 4336 EP 4352 DI 10.1103/PhysRevE.49.4336 PN B PG 17 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA NN995 UT WOS:A1994NN99500006 ER PT J AU BASKO, MM AF BASKO, MM TI RAYLEIGH-TAYLOR EIGENMODES OF A THIN-LAYER IN THE NONLINEAR REGIME SO PHYSICS OF PLASMAS LA English DT Article ID HYDRODYNAMIC INSTABILITIES; LASER-FUSION; STABILIZATION; SIMULATION; EVOLUTION; PLASMA AB In the long-wavelength limit, many aspects of the Rayleigh-Taylor (RT) instability of accelerated fluid shells can be explored by using the thin sheet approximation. For two-dimensional (2-D) planar eigenmodes, analytic nonlinear solutions [E. Ott, Phys. Rev. Lett. 29, 1429 (1972)] are available. Comparing the simplest of them for the nonconstant acceleration, g is-proportional-to t-2, with Ott's solution for constant g, the applicability of nonlinear results obtained for constant g to situations with variable acceleration is analyzed. Nonlinear three-dimensional (3-D) effects are investigated by comparing the numerical solutions- for axisymmetric Bessel eigenmodes with Ott's solution for 2-D modes. It is shown that there is a qualitative difference between 2-D and 3-D bubbles in the way they rupture a RT unstable fluid shell: In contrast to the exponential thinning of 2-D bubbles, mass is fully eroded from the top of an axisymmetric 3-D bubble within a finite time of (1.1-1.2)gamma-1 after the onset of the free-fall stage; gamma is the RT growth rate. C1 UNIV COLORADO, BOULDER, CO 80309 USA. MOSCOW THEORET & EXPTL PHYS INST, MOSCOW 117259, RUSSIA. RP NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RI Basko, Mikhail/Q-7767-2016 OI Basko, Mikhail/0000-0001-8809-8601 NR 20 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1994 VL 1 IS 5 BP 1270 EP 1278 DI 10.1063/1.870725 PN 1 PG 9 WC Physics, Fluids & Plasmas SC Physics GA NK071 UT WOS:A1994NK07100022 ER PT J AU BOLLINGER, JJ WINELAND, DJ DUBIN, DHE AF BOLLINGER, JJ WINELAND, DJ DUBIN, DHE TI NONNEUTRAL ION PLASMAS AND CRYSTALS, LASER COOLING, AND ATOMIC CLOCKS SO PHYSICS OF PLASMAS LA English DT Review ID PURE ELECTRON-PLASMA; ONE-COMPONENT PLASMA; MONTE-CARLO CALCULATIONS; FREQUENCY STANDARD; NONNEUTRAL PLASMA; FINITE LENGTH; PENNING TRAP; STORAGE RING; N-DEPENDENCE; STORED IONS AB Experimental work which uses Penning and Paul traps to confine non-neutral ion plasmas is discussed. Penning traps use a static uniform magnetic field and a static electric field to confine ions. The Paul trap uses the ponderomotive force from inhomogeneous radio-frequency fields to confine ions to a region of minimum field strength. In many atomic physics experiments, these traps are designed to produce a harmonic restoring force for small numbers of stored ions (< 10(4)). Under these conditions and at low temperatures, both traps produce plasmas with simple shapes whose mode properties can be calculated exactly. Laser cooling has been used to reduce the temperature of trapped ions to less than 10 mK with ion spacings less than 20 mum. At such temperatures and interion spacings, the Coulomb potential energy between nearest neighbor ions is greater than the ion thermal energy and the ions exhibit spatial correlations characteristic of a liquid or crystal. Laser beams also apply a torque which, by changing the plasma angular momentum, changes the plasma density. Atomic clocks are an important application of ion trap plasmas. Better control of the plasma dynamics will reduce fluctuations in the relativistic time dilation, yielding better clocks. C1 UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RP BOLLINGER, JJ (reprint author), NIST,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 76 TC 73 Z9 73 U1 3 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1994 VL 1 IS 5 BP 1403 EP 1414 DI 10.1063/1.870690 PN 2 PG 12 WC Physics, Fluids & Plasmas SC Physics GA NK072 UT WOS:A1994NK07200004 ER PT J AU COLES, WA FREHLICH, RG KOJIMA, M AF COLES, WA FREHLICH, RG KOJIMA, M TI DESIGN OF A 74-MHZ ANTENNA FOR RADIO ASTRONOMY SO PROCEEDINGS OF THE IEEE LA English DT Article AB We describe here the design and construction of an 8000 m2 74-MHz phased array dedicated to measurement of the solar-wind velocity using the interplanetary scintillation (IPS) technique, and a simple and novel autocalibration system that measures and corrects phase and amplitude errors to a level of 1-degrees and 0.2 dB rms. In the IPS technique, intensity fluctuations of compact radio sources caused by plasma turbulence in the solar wind are observed with multiple antennas. The time lag between the antennas is estimated using a cross-correlation analysis. The primary requirement of such a system is sensitivity so that one may observe a large number of compact sources. A secondary requirement is high beam efficiency so that one may observe near the sun without being overwhelmed by solar interference. The scan angle was limited to allow the largest possible array element and thus the simplest feed system. The feed was designed to have independent phase and amplitude control of each element. Although this is not strictly necessary it permits the use of the feed as a phase-switched interferometer with which any element can be correlated against any other group of elements. This provides a simple and accurate calibration of the entire array. The antenna was completely prefabricated, the site preparation was minimal, and the installation was quick and accurate. The system is remotely operated. The control information, system diagnostics, and data are transmitted over a leased telephone line. The entire system is powered by storage batteries charged by solar cells. In addition to IPS it has been used extensively for pulsar observations which have similar requirements. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA 442,JAPAN. RP COLES, WA (reprint author), UNIV CALIF SAN DIEGO,DEPT ELECT & COMP ENGN,LA JOLLA,CA 92093, USA. NR 4 TC 1 Z9 1 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 0018-9219 J9 P IEEE JI Proc. IEEE PD MAY PY 1994 VL 82 IS 5 BP 697 EP 704 DI 10.1109/5.284736 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA NL639 UT WOS:A1994NL63900007 ER PT J AU WALKER, B KASIANOWICZ, J KRISHNASASTRY, M BAYLEY, H AF WALKER, B KASIANOWICZ, J KRISHNASASTRY, M BAYLEY, H TI A PORE-FORMING PROTEIN WITH A METAL-ACTUATED SWITCH SO PROTEIN ENGINEERING LA English DT Article DE DIVALENT METAL ION; HISTIDINE; MUTAGENESIS; PORE; SENSOR; ZINC ID STAPHYLOCOCCAL ALPHA-TOXIN; DESIGNED PROTEIN; AUREUS; BINDING; MUTAGENESIS; MECHANISM; HEMOLYSIN; ENZYME; STABILIZATION; PURIFICATION AB Staphylococcal alpha-hemolysin, a pore-forming exotoxin, is a polypeptide of 293 amino acids that is secreted by Staphylococcus aureus as a water-soluble monomer. It assembles to form hexameric pores in lipid bilayers. Previous studies of pore formation have established the involvement of a central glycine-rich loop. Here, we show that when five consecutive histidine residues replace amino acids 130-134 at the midpoint of the loop, they provide a switch with which pore activity can be (i) turned off by micromolar concentrations of divalent zinc ions and (ii) turned back on with the chelating agent EDTA. Planar bilayer recordings show that Zn2+ and EDTA can act on open channels from either side of the bilayer and thus demonstrate that the central loop lines part of the conductive pathway. Our results suggest that genetically-engineered pore-forming proteins might make useful components of metal ion sensors. C1 WORCESTER FDN EXPTL BIOL INC,SHREWSBURY,MA 01545. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 48 TC 69 Z9 72 U1 1 U2 6 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0269-2139 J9 PROTEIN ENG JI Protein Eng. PD MAY PY 1994 VL 7 IS 5 BP 655 EP 662 DI 10.1093/protein/7.5.655 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA NM001 UT WOS:A1994NM00100008 PM 8073035 ER PT J AU YAN, XH ZHENG, QA HO, CR TAI, CK CHENEY, RE AF YAN, XH ZHENG, QA HO, CR TAI, CK CHENEY, RE TI DEVELOPMENT OF THE PATTERN-RECOGNITION AND THE SPATIAL INTEGRATION FILTERING METHODS FOR ANALYZING SATELLITE ALTIMETER DATA SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID EQUATORIAL KELVIN; PACIFIC-OCEAN; EL-NINO; WAVES; GEOSAT; TRANSPORT AB A pattern recognition method and a spatial integration filtering method have been developed to analyze satellite altimeter sea surface elevation anomaly (SSEA) data for the tropical Pacific Ocean. The pattern recognition method treats SSEA as an independent variable of the ocean, and SSEA map, its two-dimensional distribution image, as similar to a normal satellite image. The results of the pattern recognition processing of the SSEA maps quantitatively reveal the information of the movement of SSEA patterns. The spatial integration filtering method is used as low-pass filtering to detect the equatorial Kelvin waves from Geosat SSEA time series data. The wave patterns and the frequency spectra are derived from SSEA data. This article describes these two methods, including an overview of the algorithms used and the results derived. Further applications of the methods are then suggested. C1 NOAA,GEOSCI LAB,ROCKVILLE,MD 20852. RP YAN, XH (reprint author), UNIV DELAWARE,GRAD COLL MARINE STUDIES,CTR REMOTE SENSING,NEWARK,DE 19716, USA. RI Zheng, Quanan/F-9025-2010; Tai, C.K./F-5628-2010 NR 25 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD MAY PY 1994 VL 48 IS 2 BP 147 EP 158 DI 10.1016/0034-4257(94)90137-6 PG 12 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA NN409 UT WOS:A1994NN40900004 ER PT J AU STEHLING, KR AF STEHLING, KR TI SSC LAB - NO - SPACE LAB - NO - OCEAN LAB - YES SO SEA TECHNOLOGY LA English DT Article RP STEHLING, KR (reprint author), NOAA,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD MAY PY 1994 VL 35 IS 5 BP 93 EP 93 PG 1 WC Engineering, Ocean SC Engineering GA NL436 UT WOS:A1994NL43600014 ER PT J AU BOGGS, PT TOLLE, JW AF BOGGS, PT TOLLE, JW TI CONVERGENCE PROPERTIES OF A CLASS OF RANK-2 UPDATES SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE OPTIMIZATION; QUASI-NEWTON ALGORITHMS; MATRIX UPDATES; CONVERGENCE ANALYSIS ID QUASI-NEWTON METHODS; CONSTRAINED OPTIMIZATION; MATRICES AB Many optimization algorithms generate, at each iteration, a pair (x(k), H-k) consisting of an approximation to the solution x(k) and a Hessian matrix approximation H-k that contains local second-order information about the problem. Much is known about the convergence of x(k) to the solution of the problem, but relatively little is known about the behavior of the sequence of matrix approximations. The sequence {H-k}, generated by the extended Broyden class of updating schemes independently of the optimization setting in which they are used, is analyzed. Various conditions under which convergence is assured are derived, and the structure of the limits is delineated. Rates of convergence are also obtained. These results extend and clarify those already in the literature. C1 UNIV N CAROLINA,DEPT MATH,CHAPEL HILL,NC 27599. UNIV N CAROLINA,DEPT OPERAT RES,CHAPEL HILL,NC 27599. RP BOGGS, PT (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 15 TC 6 Z9 6 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PD MAY PY 1994 VL 4 IS 2 BP 262 EP 287 DI 10.1137/0804015 PG 26 WC Mathematics, Applied SC Mathematics GA PW285 UT WOS:A1994PW28500003 ER PT J AU HOSKER, RP AF HOSKER, RP TI WIELICZKA-SALT-MINES SO SMITHSONIAN LA English DT Letter RP HOSKER, RP (reprint author), NOAA,OAK RIDGE,TN 37830, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SMITHSONIAN ASSOCIATES PI WASHINGTON PA 900 JEFFERSON DRIVE, WASHINGTON, DC 20560 SN 0037-7333 J9 SMITHSONIAN JI Smithsonian PD MAY PY 1994 VL 25 IS 2 BP 11 EP 11 PG 1 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA NJ230 UT WOS:A1994NJ23000006 ER PT J AU LUDWIG, F DANTSKER, E NEMETH, DT KOELLE, D MIKLICH, AH CLARKE, J KNAPPE, S KOCH, H THOMSON, R AF LUDWIG, F DANTSKER, E NEMETH, DT KOELLE, D MIKLICH, AH CLARKE, J KNAPPE, S KOCH, H THOMSON, R TI FABRICATION ISSUES IN OPTIMIZING YBA2CU3O7-X FLUX TRANSFORMERS FOR LOW 1/F NOISE SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID MAGNETOMETER AB We describe an improved interconnect technology for the fabrication of multiturn flux transformers from YBa2Cu3O7-x-SrTiO3-YBa2Cu3O7-x multilayers. The essential improvements are reductions in the thicknesses of the trilayer films, typically to 100 nm, 250 nm and 250 nm respectively, and in the deposition rate, to 0.07 nm/laser pulse. This process yields crossovers in which the critical current density in the upper YBa2Cu3O7-x film at 77 K is (2-3) X 10(6) cm-2. In situ trilayers exhibited 1/f flux noise levels at 1 Hz below the measurement sensitivity of 15 muPHI0 Hz-1/2, where PHI0 is the flux quantum. However the flux noise of trilayers in which each layer had been patterned was significantly higher. The best flip-chip magnetometer had a white noise of 40 fT Hz-1/2, increasing to 340 fT Hz-1/2 at 1 Hz; the corresponding flux noise levels were 9 muPHI0 Hz-1/2 and 75 muPHI0 Hz-1/2. C1 LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. PHYS TECH BUNDESANSTALT, INST BERLIN, D-10587 BERLIN, GERMANY. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RI Koelle, Dieter/E-5111-2011 NR 13 TC 17 Z9 17 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 EI 1361-6668 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD MAY PY 1994 VL 7 IS 5 BP 273 EP 276 DI 10.1088/0953-2048/7/5/011 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA NM578 UT WOS:A1994NM57800012 ER PT J AU HARRIS, RE ONO, RH AF HARRIS, RE ONO, RH TI THIS ISSUE COMPRISES PAPERS PRESENTED AT THE INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE HELD AT BOULDER, CO, USA, IN AUGUST 1993 - FOREWORD SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Editorial Material RP HARRIS, RE (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 MAY PY 1994 VL 7 IS 5 BP U235 EP U235 PG 1 WC Physics, Applied; Physics, Condensed Matter SC Physics GA NM578 UT WOS:A1994NM57800001 ER PT J AU WANG, CM IYER, HK AF WANG, CM IYER, HK TI TOLERANCE INTERVALS FOR THE DISTRIBUTION OF TRUE VALUES IN THE PRESENCE OF MEASUREMENT ERRORS SO TECHNOMETRICS LA English DT Article DE CHI-SQUARED APPROXIMATION; GROWTH CURVES; STANDARD REFERENCE MATERIALS; VARIANCE COMPONENTS ID ANOVA RANDOM MODEL; LIMITS AB A tolerance-interval procedure for the distribution N(theta, sigma1(2) - sigma2(2)) is derived based on the mutually independent statistics theta, S1(2), and S2(2), which are distributed as follows: theta has a normal distribution with mean theta and variance sigma1(2)/n, n1S1(2)/sigma1(2) is chi-squared with n1 df, and n2S2(2)/sigma2(2) is chi-squared with n2 df. Application to the construction of tolerance intervals for the distribution of true values when observations are contaminated with measurement errors is explained. This includes the problem of constructing tolerance intervals in some growth-curve models. Numerical examples are given to illustrate the procedures. C1 COLORADO STATE UNIV,DEPT STAT,FT COLLINS,CO 80523. RP WANG, CM (reprint author), NATL INST STAND & TECHNOL,DIV STAT ENGN,BOULDER,CO 80303, USA. NR 25 TC 25 Z9 25 U1 0 U2 2 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD MAY PY 1994 VL 36 IS 2 BP 162 EP 170 DI 10.2307/1270228 PG 9 WC Statistics & Probability SC Mathematics GA NH522 UT WOS:A1994NH52200009 ER PT J AU VANDENDOOL, HM AF VANDENDOOL, HM TI SEARCHING FOR ANALOGS, HOW LONG MUST WE WAIT SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article AB A three-way relationship is derived between the size of a library (M years) of historical atmospheric data, the distance between an arbitrarily picked state of the atmosphere and its nearest neighbor (or analogue), and the size of the spatial domain, as measured by the number of spatial degrees of freedom (N). It is found that it would take a library of order 10(30) years to find 2 observed flows that match to within current observational error over a large area such as the Northern Hemisphere. Obviously, with only 10-100 years of data, the probability of finding natural analogous is very small, unless one is satisfied with analogy over small areas or in just 2 of 3 degrees of freedom as represented, for instance, by 2 or 3 leading empirical orthogonal modes. We further propose the notion that analogues can be constructed by combining a number of observed flow patterns. We have found at least one application where linearly constructed analogues are conclusively better at specifying US surface weather from concurrent 700 mb geopotential height than natural analogues are. RP VANDENDOOL, HM (reprint author), NOAA,NWS,NMC,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 0 TC 143 Z9 143 U1 1 U2 3 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 MAY PY 1994 VL 46 IS 3 BP 314 EP 324 DI 10.1034/j.1600-0870.1994.t01-2-00006.x PG 11 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA NL588 UT WOS:A1994NL58800006 ER PT J AU BRANNAS, E LUNDQVIST, H PRENTICE, E SCHMITZ, M BRANNAS, K WIKLUND, BS AF BRANNAS, E LUNDQVIST, H PRENTICE, E SCHMITZ, M BRANNAS, K WIKLUND, BS TI USE OF THE PASSIVE INTEGRATED TRANSPONDER (PIT) IN A FISH IDENTIFICATION AND MONITORING-SYSTEM FOR FISH BEHAVIORAL-STUDIES SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SALVELINUS-ALPINUS AB Use of the passive integrated transponder (PIT) as a fish identification and monitoring system for behavioral study of Arctic char Salvelinus alpinus was evaluated. The system was developed in order to track individual differences, mainly in rheotactic behavior. In a preliminary experimental setup, Arctic char (N = 20, 9-140 g each) were PIT-tagged and their movements were recorded at regular intervals in a circular stream channel. Two PIT tag loop detectors, placed on a narrow part of the channel, automatically recorded identity and swimming direction of tagged fish. We demonstrate some of the applications in behavioral research, such as individual, general, and diel locomotor activity patterns, rheotactic behavior, and sociograms showing activity relationships among individuals within a group. C1 NATL MARINE FISHERIES SERV,MANCHESTER,WA 98353. UMEA UNIV,DEPT ECON,S-90187 UMEA,SWEDEN. RP BRANNAS, E (reprint author), SWEDISH UNIV AGR SCI,DEPT AQUACULTURE,S-90183 UMEA,SWEDEN. NR 10 TC 46 Z9 46 U1 2 U2 16 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 MAY PY 1994 VL 123 IS 3 BP 395 EP 401 DI 10.1577/1548-8659(1994)123<0395:UOTPIT>2.3.CO;2 PG 7 WC Fisheries SC Fisheries GA NT404 UT WOS:A1994NT40400013 ER PT J AU JAFVERT, CT VANHOOF, PL HEATH, JK AF JAFVERT, CT VANHOOF, PL HEATH, JK TI SOLUBILIZATION OF NONPOLAR COMPOUNDS BY NONIONIC SURFACTANT MICELLES SO WATER RESEARCH LA English DT Article DE SURFACTANT; HEXACHLOROBENZENE; POLYETHOXYLATE; PHASE DISTRIBUTION; PARTITIONING SOLUBILIZATION; REMEDIATION ID POLYOXYETHYLENE LAURYL ETHER; ORGANIC-COMPOUNDS; PARTITION-COEFFICIENTS; WATER SOLUBILITY; SYSTEMS AB The distribution of non-polar hydrophobic organic compounds (HOCs) between various surfactant micellar pseudophases and water is examined. Experimental measurements have been made with nine non-ionic surfactants and one anionic surfactant with hexachlorobenzene. These distributions have been quantified with micelle-water partition coefficients, K-m(M(-1)), which are calculated utilizing the chemical's solubility in distilled water. With this data and information previously published on other HOCs and surfactants, a simple semi-empirical equation was constructed that relates micelle-water partition coefficients, K-m, to octanol-water partition coefficients, K-ow, and surfactant structural properties. Only two parameters in the final equation define surfactant structural characteristics. A rationale of the final model construct is presented. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. TECHNOL APPLICAT INC,ATHENS,GA 30613. RP JAFVERT, CT (reprint author), PURDUE UNIV,SCH CIVIL ENGN,W LAFAYETTE,IN 47907, USA. RI Jafvert, Chad/D-9551-2013 NR 23 TC 117 Z9 119 U1 2 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0043-1354 J9 WATER RES JI Water Res. PD MAY PY 1994 VL 28 IS 5 BP 1009 EP 1017 DI 10.1016/0043-1354(94)90185-6 PG 9 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA NC448 UT WOS:A1994NC44800002 ER PT J AU BOETTINGER, WJ WHEELER, AA MURRAY, BT MCFADDEN, GB AF BOETTINGER, WJ WHEELER, AA MURRAY, BT MCFADDEN, GB TI PREDICTION OF SOLUTE TRAPPING AT HIGH SOLIDIFICATION RATES USING A DIFFUSE INTERFACE PHASE-FIELD THEORY OF ALLOY SOLIDIFICATION SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID MODEL; TRANSITIONS; BOUNDARY; KINETICS; GROWTH; MOTION AB A phase-field model for solidification of a binary alloy is developed that includes gradient energy contributions for the phase field and for the composition field. When the gradient energy coefficient for the phase field is smaller than that for the solute field, planar steady-state solutions exhibit a reduction in segregation in the liquid phase ahead of an advancing front (solute trapping), and in the limit of high solidification speeds predict alloy solidification with no redistribution of composition. Comparison is made with the Aziz model of solute trapping. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 27 TC 39 Z9 41 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD APR 30 PY 1994 VL 178 IS 1-2 BP 217 EP 223 DI 10.1016/0921-5093(94)90546-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA NH615 UT WOS:A1994NH61500039 ER PT J AU PRATT, KW AF PRATT, KW TI AUTOMATED, HIGH-PRECISION COULOMETRIC TITRIMETRY .1. ENGINEERING AND IMPLEMENTATION SO ANALYTICA CHIMICA ACTA LA English DT Article DE COULOMETRY (CONSTANT-CURRENT); AUTOMATED TITRIMETRY; HIGH-PRECISION ASSAYS; PRIMARY STANDARDS AB Automated constant-current coulometry, based on Faraday's Laws, achieves uncertainties (relative standard deviation) of less than 1 part in 20000 without chemical standardization. It is applicable to acid-base, redox, and precipitation titrations of high-purity compounds and solutions. Automation of the technique permits unsupervised operation and reduces operator-dependent errors. Initial setup and sample introduction are the sole manual steps. Each assay consists of a main titration at high, constant current, bracketed by the initial and final endpoint routines, each at a lower current. The coulometric assay is analogous to a conventional titration in which two different concentrations of the titrant are used to attain optimum accuracy. The initial endpoint determination corresponds to the blank determination in a classical titration. Each titration includes a statistical analysis of the random and systematic uncertainties associated with the analysis. Individual steps in the procedure are performed by a hierarchical series of subroutines to reduce program complexity. Results are presented for K2Cr2O7, benzoic acid, and solutions of strong acids. RP PRATT, KW (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 12 TC 15 Z9 15 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD APR 29 PY 1994 VL 289 IS 2 BP 125 EP 134 DI 10.1016/0003-2670(94)80095-2 PG 10 WC Chemistry, Analytical SC Chemistry GA NH533 UT WOS:A1994NH53300001 ER PT J AU PRATT, KW AF PRATT, KW TI AUTOMATED, HIGH-PRECISION COULOMETRIC TITRIMETRY .2. STRONG AND WEAK ACIDS AND BASES SO ANALYTICA CHIMICA ACTA LA English DT Article DE COULOMETRY; AUTOMATED ANALYSIS; ACIDIMETRY; HIGH-PRECISION ASSAY AB Automated constant-current coulometric acidimetry, based on Faraday's Laws, is uncertain to less than 1 part in 20000 (relative standard deviation) and requires no chemical standardization. It is applicable to strong and weak acids and bases, with bases back-titrated after addition of excess strong acid. Initial setup and sample introduction are the sole manual steps. Assays of HCl, benzoic acid, Na2CO3, and tris(hydroxymethyl)aminomethane are presented. In the endpoint determination procedure, a generalized titration equation yields the theoretical charge remaining to the endpoint before each charge addition. The ratio of the experimental to the theoretical charge for the preceding aliquot corrects for experimental deviations. RP PRATT, KW (reprint author), NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 13 TC 13 Z9 13 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD APR 29 PY 1994 VL 289 IS 2 BP 135 EP 142 DI 10.1016/0003-2670(94)80096-0 PG 8 WC Chemistry, Analytical SC Chemistry GA NH533 UT WOS:A1994NH53300002 ER PT J AU YAMASAKI, S BINZ, T HAYASHI, T SZABO, E YAMASAKI, N EKLUND, M JAHN, R NIEMANN, H AF YAMASAKI, S BINZ, T HAYASHI, T SZABO, E YAMASAKI, N EKLUND, M JAHN, R NIEMANN, H TI BOTULINUM NEUROTOXIN TYPE-G PROTEOLYSES THE ALA(81)-ALA(82) BOND OF RAT SYNAPTOBREVIN-2 SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID INTEGRAL MEMBRANE-PROTEIN; SYNAPTIC VESICLES; BRAIN AB Tetanus toxin and the botulinum neurotoxins types A to F inhibit neurotransmitter release from presynaptic nerve endings by selectively proteolysing the synaptic proteins synaptobrevin, syntaxin, or SNAP-25. Here, we show that botulinum toxin type G cleaves rat synaptobrevin 2 between Ala(81) and Ala(82), a peptide bond that differs from those attacked by tetanus toxin and the botulinal toxins types B, D, and F. Synaptobrevin isoforms carrying a Gly in the P1 position are poor substrates. Analyses of N-terminal deletion mutants of rat synaptobrevin 2 showed that a substrate starting at Leu(54) is cleaved efficiently, whereas substrates beginning at Leu(60) or Phe(77) are cleaved partially or not at all, respectively. (C) 1994 Academic Press, Inc. C1 FED RES CTR VIRUS DIS ANIM,DEPT MICROBIOL,D-72001 TUBINGEN,GERMANY. YALE UNIV,SCH MED,DEPT PHARMACOL,NEW HAVEN,CT 06510. YALE UNIV,SCH MED,DEPT CELL BIOL,NEW HAVEN,CT 06510. YALE UNIV,SCH MED,HOWARD HUGHES MED INST,NEW HAVEN,CT 06510. NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,SEATTLE,WA 98112. NR 24 TC 100 Z9 102 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 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD APR 29 PY 1994 VL 200 IS 2 BP 829 EP 835 DI 10.1006/bbrc.1994.1526 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA NH738 UT WOS:A1994NH73800024 PM 7910017 ER PT J AU BOYES, SJ AF BOYES, SJ TI THE INTERATOMIC POTENTIAL OF ARGON SO CHEMICAL PHYSICS LETTERS LA English DT Article ID THERMAL-CONDUCTIVITY; VIRIAL-COEFFICIENTS; ROOM-TEMPERATURE; ABSOLUTE DETERMINATION; NOBLE-GASES; NITROGEN; VISCOSITY; PRESSURES; HYDROGEN; HELIUM AB The recent literature abounds with proposed interatomic potential functions for argon. Of these the Hartree-Fock dispersion (HFD) type functions have been very successful and are considered to be among the best characterizations of the argon interaction to date. It is the purpose of this Letter, however, to show that of the proposed HFD-type potentials, none predict the recent acoustic virial coefficients measured by Moldover et al. In view of this an alternative interatomic potential has been constructed for argon. The potential is of the Hartree-Fock dispersion individually damped (HFD-ID) type and represents a subtle but significant improvement for the interaction. RP BOYES, SJ (reprint author), NATL INST STAND & TECHNOL, DIV THERMOPHYS, GAITHERSBURG, MD 20899 USA. NR 51 TC 23 Z9 23 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 29 PY 1994 VL 221 IS 5-6 BP 467 EP 472 DI 10.1016/0009-2614(94)00303-3 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NJ120 UT WOS:A1994NJ12000023 ER PT J AU TURNIPSEED, AA BARONE, SB RAVISHANKARA, AR AF TURNIPSEED, AA BARONE, SB RAVISHANKARA, AR TI KINETICS OF THE REACTIONS OF CF3OX RADICALS WITH NO, O3 AND O2 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID UV ABSORPTION; 222 NM; OZONE AB The technique of pulsed laser photolysis/pulsed laser-induced fluorescence detection of CF3O was used to study the stratospherically important reactions of CF3O radicals with NO (k(5))r O-3 (k(4)), and O-2 (k(6)) and that of CF3-OO with NO (k(2)) and O-3 (k(3)). Over the temperature range 233-360, K, k(5)(T) = (3.34 +/- 0.68) X 10(-11) exp[(l60 +/- 45)/T] cm(3) molecule(-1) s(-1). At 298 K, k(2) = (1.57 /- 0.38) x 10(-11) cm(3) molecule(-1) s(-1) in agreement with past work. The reactions of CF3O and CF3OO with O-3 were found to be slow with rate coefficients at 298 K of k(4) = (2.5(-1.5)(+0.7)) x 10(-14) cm(3) molecule(-1) s(-1) and k(3) less than or equal to 7 x 10(-5) cm(3) molecule(-1) s(-1), respectively. No reaction of CF3O with O-2 was observed at 298 or 373 K, leading to an upper limit of k(6) less than or equal to 4 x 10(-17) cm(3) molecule(-1) s(-1) at 373 K. The implications of these results to the chemistry of CF3Ox radicals and O-3 in the stratosphere are discussed. C1 NOAA,AERON LAB,ERL,RE AL 2,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 33 TC 45 Z9 45 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 28 PY 1994 VL 98 IS 17 BP 4594 EP 4601 DI 10.1021/j100068a019 PG 8 WC Chemistry, Physical SC Chemistry GA NJ538 UT WOS:A1994NJ53800019 ER PT J AU BARONE, SB TURNIPSEED, AA RAVISHANKARA, AR AF BARONE, SB TURNIPSEED, AA RAVISHANKARA, AR TI KINETICS OF THE REACTIONS OF THE CF3O RADICAL WITH ALKANES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID A2A1-X2E TRANSITION; TRIFLUOROMETHOXY AB Utilizing the technique of pulsed laser photolysis/pulsed laser induced fluorescence, we have investigated the atmospherically important reactions of the (trifluoromethyl)peroxy radical, CF3O, with several alkanes. The reaction rate coefficients for CF3O + CH4 (k(3)), C2H6 (k4), C3H8 (k(5)), (CH3)(3)CH (k(6)), and CD4 (k(7)) Were measured, as functions of temperature, to be k(3) = (1.92 +/- 0.33) X 10(-12) exp[-(1370 +/- 85)/T] cm(3) molecule(-1) s(-1), k(4) = (4.84 +/- 1.11) X 10(-12) exp[-(400 +/- 70)/T] cm(3) molecule(-1) s(-1), k(5) = (5.12 +/- 1.12) X 10(-12) exp[-(15 +/- 30)/T] cm(3) molecule(-1) s(-1), k(6) = (4.32 +/- 0.42) X 10(-12) exp[(135 +/- 30)/T] cm(3) molecule(-1) s(-1), and k(7) = (0.91 +/- 0.31) X 10(-12) exp[-(1540 +/- 100)] cm(3) molecule(-1) s(-1), respectively. These kinetic data are compared with results from previous studies. The atmospheric implications of these findings are discussed. C1 NOAA,AERON LAB,ERL,RE AL2,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 33 TC 43 Z9 43 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 28 PY 1994 VL 98 IS 17 BP 4602 EP 4608 DI 10.1021/j100068a020 PG 7 WC Chemistry, Physical SC Chemistry GA NJ538 UT WOS:A1994NJ53800020 ER PT J AU GULDI, DM NETA, P ASMUS, KD AF GULDI, DM NETA, P ASMUS, KD TI ELECTRON-TRANSFER REACTIONS BETWEEN C-60 AND RADICAL IONS OF METALLOPORPHYRINS AND ARENES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PULSE-RADIOLYSIS; CHROMIUM(III) PORPHYRINS; 2-ELECTRON REDUCTION; ABSORPTION-SPECTRA; C60; CATIONS; OXIDATION; ANIONS; BUCKMINSTERFULLERENE; PYRIDYLPORPHYRINS AB Electron-transfer reactions with C-60 leading to the singly reduced and oxidized radical ions, C-60(.-) and C-60(.+) have been studied by pulse radiolysis. pi-Radical anions of several metalloporphyrins (tetraphenyl- and tetrapyridylporphyrins) reduced C-60 With rate constants of (1-3) x 10(9) L mol(-1) s(-1), whereas metalloporphyrins which are reduced at the metal center (Ni-I, Cu-I, Cr-II) reacted with C-60 somewhat more slowly, with rate constants of (0.7-2.3) x 10(8) L mol(-1) s(-1). Sb(V)OEP(.-) (octaethylporphyrin) did not reduce C-60 (k less than or equal to 10(7) L mol(-1) s(-1)) and Sn-IV(Ph)(3)(Py)P-.- reacted in an equilibrium process (K = 14). Electron transfer from C-60 to several aromatic radical cations (derived from naphthalene, biphenyl, m-terphenyl, and trans-stilbene) also took place rapidly (k = (2.5-7.9) x 10(9) L mol(-1) s(-1)) to produce C-60(.+); the radical cations of anthracene and chrysene, on the other hand, did not exhibit any significant reactivity toward C-60. C1 HAHN MEITNER INST BERLIN GMBH, BEREICH S, STRAHLENCHEM ABT, D-14109 BERLIN, GERMANY. RP GULDI, DM (reprint author), NIST, DIV CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20899 USA. RI Guldi, Dirk/G-1422-2015 NR 31 TC 51 Z9 51 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 APR 28 PY 1994 VL 98 IS 17 BP 4617 EP 4621 DI 10.1021/j100068a022 PG 5 WC Chemistry, Physical SC Chemistry GA NJ538 UT WOS:A1994NJ53800022 ER PT J AU GELTMAN, S AF GELTMAN, S TI SHORT-PULSE MODEL-ATOM STUDIES OF IONIZATION IN INTENSE LASER FIELDS SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID MULTIPHOTON IONIZATION; SUPPRESSION; RADIATION AB We study the evolution of ionization probability in a simple one-dimensional model atom with a delta-function potential for very short, intense laser pulses. The intensities are in the ranges where tunnelling and over-the-barrier ionization take place. A full numerical solution for the time-dependent Schrodinger equation is obtained and a detailed comparison is made between the results for rectangular and smooth pulses. The ultra-intense field limit is verified to follow the ionization expected from an oscillating Volkov wavepackect which is uniformly spreading. No signs of ionization suppression or bound state stabilization are seen. RP GELTMAN, S (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 19 TC 21 Z9 22 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 28 PY 1994 VL 27 IS 8 BP 1497 EP 1514 DI 10.1088/0953-4075/27/8/011 PG 18 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NK149 UT WOS:A1994NK14900011 ER PT J AU BALSARA, NP HAMMOUDA, B KESANI, PK JONNALAGADDA, SV STRATY, GC AF BALSARA, NP HAMMOUDA, B KESANI, PK JONNALAGADDA, SV STRATY, GC TI IN-SITU SMALL-ANGLE NEUTRON-SCATTERING FROM A BLOCK-COPOLYMER SOLUTION UNDER SHEAR SO MACROMOLECULES LA English DT Article ID CONCENTRATION FLUCTUATIONS; FLOW; TRANSITION; ORDER; BIREFRINGENCE AB Small-angle neutron scattering profiles from a concentrated (65 wt %) polystyrene-polyisoprene block copolymer solution in dioctyl phthalate under shear were obtained both above and below the quiescent order-disorder transition (ODT). The ordered solution has a lamellar structure under quiescent conditions. The shear-induced structure was inferred from scattering measurements in two planes: the v-vxdelv plane and the delv-vxdelv plane (v is the fluid velocity direction and delv is the velocity gradient direction). Below the quiescent ODT, oscillatory shear produces lamellae that are aligned along the shearing surface, while steady shear results in a reorientation of the lamellae normals from the v-vxdelv plane to the delv-vxdelv plane. Above the quiescent ODT, steady shear induces order above a critical shear rate. The resulting scattering anisotropy obtained at different temperatures obeys a universal scaling law, and the critical shear rate increases exponentially with temperature. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NATL INST STAND & TECHNOL, DIV THERMOPHYS, BOULDER, CO 80303 USA. RP POLYTECH INST NEW YORK, SIX METROTECH CTR, DEPT CHEM ENGN, BROOKLYN, NY 11201 USA. NR 31 TC 67 Z9 67 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD APR 25 PY 1994 VL 27 IS 9 BP 2566 EP 2573 DI 10.1021/ma00087a027 PG 8 WC Polymer Science SC Polymer Science GA NJ226 UT WOS:A1994NJ22600027 ER PT J AU ZHANG, ZG PADMAJA, S SAINI, RD HUIE, RE KURYLO, MJ AF ZHANG, ZG PADMAJA, S SAINI, RD HUIE, RE KURYLO, MJ TI REACTIONS OF HYDROXYL RADICALS WITH SEVERAL HYDROFLUOROCARBONS - THE TEMPERATURE DEPENDENCIES OF THE RATE CONSTANTS FOR CHF2CF2CH(2)F (HFC-245CA), CF3CHFCHF2 (HFC-236EA), CF3CHFCF3 (HFC-227EA), AND CF3CH2CH2CF3 (HFC-356FFA) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID OH; HYDROCHLOROFLUOROCARBONS; KINETICS AB Rate constants were determined for the gas-phase reactions of the hydroxyl radical with four hydrofluorocarbon compounds, CF3CHFCF3 (HFC-227ea), CF3CHFCHF2 (HFC-236ea), CHF2CF2CH2F (HFC-245ca), and CF3CH2CH2CF3 (HFC-356ffa), using the flash photolysis resonance fluorescence technique over the temperature range 260-365 K. Arrhenius expressions were derived for the four OH reactions: k(CF3CHFCF3) = 3.63 X 10-(13) exp[(1613 +/- 135)/T], k(CF3CHFCHF2) = 1.05 x 10(-12) exp[(1434 +/- 161)/T], k(CHF2CF2CH2F) = 2.87 X 10(-12) exp[(1661 +/- 170)/T],and k(CF3CH2CH2CF3) = 2.94 X 10(-12)exp[(1734 +/- 87)/T] cm(3) molecule(-1) s(-1). Tropospheric lifetimes for the four compounds were estimated to be 43, 7.8, 6.5, and 8.2 years, respectively. C1 NIST,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 16 TC 27 Z9 28 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 21 PY 1994 VL 98 IS 16 BP 4312 EP 4315 DI 10.1021/j100067a017 PG 4 WC Chemistry, Physical SC Chemistry GA NH490 UT WOS:A1994NH49000017 ER PT J AU CHURNSIDE, JH HANSON, SG AF CHURNSIDE, JH HANSON, SG TI EFFECT OF PENETRATION DEPTH AND SWELL-GENERATED TILT ON DELTA-K-LIDAR PERFORMANCE SO APPLIED OPTICS LA English DT Article ID SURFACE; SEA; FREQUENCY; RADAR AB Delta-k lidar can be used to measure the amplitudes of small waves on the surface of the ocean as long as the tilt of the surface is known. This tilt can be inferred from DELTAk measurements at orthogonal polarizations. The wavelength of the lidar must be chosen so that the penetration depth of the light is much less than the length of the surface wave being measured; otherwise, the DELTAk signal will be reduced. C1 RISO NATL LAB, DK-4000 ROSKILDE, DENMARK. RP CHURNSIDE, JH (reprint author), NOAA, ENVIRONM RES LAB, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. RI Hanson, Steen/E-6542-2010; Churnside, James/H-4873-2013 NR 9 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1994 VL 33 IS 12 BP 2363 EP 2368 PG 6 WC Optics SC Optics GA NF491 UT WOS:A1994NF49100017 PM 20885587 ER PT J AU REICHERT, GA RODRIGUEZPASCUAL, PM ALLOIN, D CLAVEL, J CRENSHAW, DM KRISS, GA KROLIK, JH MALKAN, MA NETZER, H PETERSON, BM WAMSTEKER, W ALTAMORE, A ALTIERI, B ANDERSON, KS BLACKWELL, JH BOISSON, C BROSCH, N CARONE, TE DIETRICH, M ENGLAND, MN EVANS, IN FILIPPENKO, AV GASKELL, CM GOAD, M GONDHALEKAR, PM HORNE, K KAZANAS, D KOLLATSCHNY, W KORATKAR, AP KORISTA, KT MACALPINE, GM MAOZ, D MAZEH, T MCCOLLUM, B MILLER, HR DEOLIVEIRA, CM OBRIEN, PT PASTORIZA, MG PELAT, D PEREZ, E PEROLA, GC POGGE, RW PTAK, RL RECONDOGONZALEZ, MC RODRIGUEZESPINOSA, J ROSENBLATT, EI SADUN, AC SANTOSLLEO, M SHIELDS, JC SHRADER, CR SHULL, JM SIMKIN, SM SITKO, ML SNIJDERS, MAJ SPARKE, LS STIRPE, GM STONER, R STORCHIBERGMANN, T SUN, WH WANG, T WELSH, WF WHITE, RJ WINGE, C ZHENG, W AF REICHERT, GA RODRIGUEZPASCUAL, PM ALLOIN, D CLAVEL, J CRENSHAW, DM KRISS, GA KROLIK, JH MALKAN, MA NETZER, H PETERSON, BM WAMSTEKER, W ALTAMORE, A ALTIERI, B ANDERSON, KS BLACKWELL, JH BOISSON, C BROSCH, N CARONE, TE DIETRICH, M ENGLAND, MN EVANS, IN FILIPPENKO, AV GASKELL, CM GOAD, M GONDHALEKAR, PM HORNE, K KAZANAS, D KOLLATSCHNY, W KORATKAR, AP KORISTA, KT MACALPINE, GM MAOZ, D MAZEH, T MCCOLLUM, B MILLER, HR DEOLIVEIRA, CM OBRIEN, PT PASTORIZA, MG PELAT, D PEREZ, E PEROLA, GC POGGE, RW PTAK, RL RECONDOGONZALEZ, MC RODRIGUEZESPINOSA, J ROSENBLATT, EI SADUN, AC SANTOSLLEO, M SHIELDS, JC SHRADER, CR SHULL, JM SIMKIN, SM SITKO, ML SNIJDERS, MAJ SPARKE, LS STIRPE, GM STONER, R STORCHIBERGMANN, T SUN, WH WANG, T WELSH, WF WHITE, RJ WINGE, C ZHENG, W TI STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI .5. VARIABILITY OF THE ULTRAVIOLET CONTINUUM AND EMISSION-LINES OF NGC-3783 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, ACTIVE; GALAXIES, INDIVIDUAL (NGC 3783); GALAXIES, NUCLEI; GALAXIES, SEYFERT; ULTRAVIOLET, GALAXIES ID SEYFERT-GALAXY NGC-5548; OPTICAL WAVELENGTHS; EXPLORER IUE; SWP CAMERA; FE-II; NGC-3783; QUASARS; SPECTROSCOPY; ACCURACY; GEOMETRY AB We report on the result of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or ''dips,'' the first lasting less than or similar to 20 days and the second less than or similar to 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became ''harder'' when brighter. The variations in the continuum occurred simultaneously at all wavelengths (Delta t <2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Ly alpha), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or ''lag'' As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of(formally) similar to 0 days for He II + O III], and similar to 4 days for Ly alpha and C IV. The data further suggest lags of similar to 4 days for Si IV + O IV] and 8-30 days for Si III] + C III]. Mg II lagged the 1460 Angstrom continuum by similar to 9 days, although this result depends on the method of measuring the line flux and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over timescales of less than or similar to 2 days, and that the character of the continuum variability may change with time. C1 ESA IUE OBSERV,E-28080 MADRID,SPAIN. UNIV PARIS 07,OBSERV PARIS,CNRS,URA 173,F-92195 MEUDON,FRANCE. EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,DIV ASTROPHYS,ISO OBSERV,2200 AG NOORDWIJK,NETHERLANDS. NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,ASTRON PROGRAM,GREENBELT,MD 20771. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024. TEL AVIV UNIV,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. TEL AVIV UNIV,WISE OBSERV,IL-69978 TEL AVIV,ISRAEL. OHIO STATE UNIV,DEPT ASTRON,COLUMBUS,OH 43210. UNIV ROMA LA SAPIENZA,IST ASTRON,I-00161 ROME,ITALY. EUROPEAN SO OBSERV,SANTIAGO 19001,CHILE. NEW MEXICO STATE UNIV,DEPT ASTRON,LAS CRUCES,NM 88003. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV STERNWARTE,W-3400 GOTTINGEN,GERMANY. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. RUTHERFORD APPLETON LAB,ASTROPHYS GRP,DIDCOT OX11 0QX,OXON,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. UNIV MICHIGAN,DEPT ASTRON,ANN ARBOR,MI 48109. INST ADV STUDY,PRINCETON,NJ 08540. NASA,WASHINGTON,DC 20546. GEORGIA STATE UNIV,DEPT PHYS & ASTRON,ATLANTA,GA 30303. UNIV BRITISH COLUMBIA,DEPT ASTRON,VANCOUVER V6T 1W5,BC,CANADA. UNIV FED RIO GRANDE SUL,INST FIS,DEPT ASTRON,BR-91500 PORTO ALEGRE,RS,BRAZIL. INST ASTROFIS CANARIAS,E-38200 LA LAGUNA,SPAIN. BOWLING GREEN STATE UNIV,DEPT PHYS & ASTRON,BOWLING GREEN,OH 43403. UNIV CALIF SAN DIEGO,CTR ASTROPHYS & SPACE SCI,LA JOLLA,CA 92093. AGNES SCOTT COLL,DEPT PHYS & ASTRON,DECATUR,GA 30030. AGNES SCOTT COLL,BRADLEY OBSERV,DECATUR,GA 30030. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. UNIV TUBINGEN,INST ASTRON,W-7400 TUBINGEN,GERMANY. UNIV WISCONSIN,DEPT ASTRON,MADISON,WI 53706. OSSERV ASTRON BOLOGNA,I-40126 BOLOGNA,ITALY. NATL CENT UNIV,ASTRON INST,CHUNGLI 32054,TAIWAN. UNIV SCI & TECHNOL CHINA,HEFEI 230026,PEOPLES R CHINA. RP REICHERT, GA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 668,GREENBELT,MD 20771, USA. RI Brosch, Noah/C-7889-2009; Mendes de Oliveira, Claudia/F-2391-2012; 王, 挺贵/B-8293-2013; Recondo, Carmen/B-1215-2012; Stirpe, Giovanna/O-9393-2015; OI Mendes de Oliveira, Claudia/0000-0002-7736-4297; Recondo, Carmen/0000-0001-9813-6798; Stirpe, Giovanna/0000-0002-3702-8731; Gaskell, C/0000-0003-4888-2009; Perez, Enrique/0000-0001-9737-4559 NR 67 TC 117 Z9 117 U1 3 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1994 VL 425 IS 2 BP 582 EP 608 DI 10.1086/174007 PN 1 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PM579 UT WOS:A1994PM57900017 ER PT J AU ARPAG, KH JOHNSTON, PV MILLER, HL SANDERS, RW SOLOMON, S AF ARPAG, KH JOHNSTON, PV MILLER, HL SANDERS, RW SOLOMON, S TI OBSERVATIONS OF THE STRATOSPHERIC BRO COLUMN OVER COLORADO, 40-DEGREES-N SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NEAR-ULTRAVIOLET SPECTROSCOPY; MCMURDO-STATION; ABSORPTION-MEASUREMENTS; ANTARCTICA; ABUNDANCES; OZONE; OCLO; O-3; NO2; DESTRUCTION AB The column abundance of BrO has been measured at 40-degrees-N throughout the period from January 22 to May 24,1993, providing the first remote sensing observations of this key molecule at midlatitudes. The near-ultraviolet BrO absorption bands at 349 and 355 nm have been clearly identified in the measured scattered sky spectra, with additional confirmation provided by the 339-nm band and by analysis tests showing that spectral overlap with NO2 does not pose a problem for BrO measurement. The observed slant column abundances showed substantial variability and may be affected in part by heterogeneous chemistry associated with Pinatubo aerosols. The zenith angle dependence and magnitude of the slant column measurements indicate that the bulk of the BrO is located near 15-20 km and that the mixing ratio there is of the order of 5-8 parts per trillion by volume. C1 NATL INST WATER & ATMOSPHER RES, OTAGA, NEW ZEALAND. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP ARPAG, KH (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Miller, Henry/D-7628-2013 OI Miller, Henry/0000-0002-7155-8314 NR 27 TC 30 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1994 VL 99 IS D4 BP 8175 EP 8181 DI 10.1029/94JD00144 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NH263 UT WOS:A1994NH26300010 ER PT J AU GRANT, WB BROWELL, EV FISHMAN, J BRACKETT, VG VEIGA, RE NGANGA, D MINGA, A CROS, B BUTLER, CF FENN, MA LONG, CS STOWE, LL AF GRANT, WB BROWELL, EV FISHMAN, J BRACKETT, VG VEIGA, RE NGANGA, D MINGA, A CROS, B BUTLER, CF FENN, MA LONG, CS STOWE, LL TI AEROSOL-ASSOCIATED CHANGES IN TROPICAL STRATOSPHERIC OZONE FOLLOWING THE ERUPTION OF MOUNT-PINATUBO SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIRBORNE LIDAR OBSERVATIONS; GAS EXPERIMENT-II; EL-CHICHON; HETEROGENEOUS CHEMISTRY; SULFATE AEROSOLS; MT-PINATUBO; SAGE-I; SATELLITE; DEPLETION; PROFILES AB The large amount of sulfuric acid aerosol formed in the stratosphere by conversion of sulfur dioxide emitted by the eruption of Mount Pinatubo (15.14-degrees-N, 120.35-degrees-E) in the Philippines around June 15, 1991, has had a pronounced effect on lower stratospheric ozone in the tropics. Measurements of stratospheric ozone in the tropics using electrochemical concentration cell (ECC) sondes before and after the eruption and the airborne UV differential absorption lidar (DIAL) system after the eruption are compared with Stratospheric Aerosol and Gas Experiment II (SAGE II) measurements from several years before the eruption and ECC sonde measurements from the year prior to the eruption to determine the resulting changes. Ozone decreases of up to 33% compared with SAGE II climatological values were found to be directly correlated with altitude regions of enhanced aerosol loading in the 16- to 28-km range. A maximum partial-column decrease of 29 +/- 9 Dobson units (DU) was found over the 16- to 28-km range in September 1991 along with small increases (to 5.9 +/- 2 DU) from 28 to 31.5 km. A large decrease of ozone was also found at 4-degrees to 8-degrees-S from May to August 1992, with a maximum decrease of 33 +/- 7 DU found above Brazzaville in July. Aerosol data from the visible channel of the advanced very high resolution radiometer (AVHRR) and the visible wavelength of the UV DIAL system were used to examine the relationship between aerosol (surface area) densities and ozone changes. The tropical stratospheric ozone changes we observed in 1991 and 1992 are likely be explained by a combination of dynamical (vertical transport) perturbations, radiative perturbations on ozone photochemistry, and heterogeneous chemistry. C1 SCI APPLICAT INT CORP, HAMPTON, VA USA. UNIV MAIEN NGOUABI, BRAZZAVILLE, CONGO. NOAA, NWS, NMC, CTR CLIMATE ANAL, WASHINGTON, DC 20230 USA. NOAA, NESDIS, ORA, SATELLITE RES LAB, WASHINGTON, DC 20230 USA. RP GRANT, WB (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23665 USA. RI Grant, William/B-8311-2009 OI Grant, William/0000-0002-1439-3285 NR 79 TC 79 Z9 80 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1994 VL 99 IS D4 BP 8197 EP 8211 DI 10.1029/93JD03314 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NH263 UT WOS:A1994NH26300012 ER PT J AU MCINNES, LM COVERT, DS QUINN, PK GERMANI, MS AF MCINNES, LM COVERT, DS QUINN, PK GERMANI, MS TI MEASUREMENTS OF CHLORIDE DEPLETION AND SULFUR ENRICHMENT IN INDIVIDUAL SEA-SALT PARTICLES COLLECTED FROM THE REMOTE MARINE BOUNDARY-LAYER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PACIFIC-OCEAN; AEROSOLS; CHEMISTRY AB Changes in the elemental ratios of Cl/Na and S/Na in sea-salt particles are expected from the atmospheric reactions of sulfuric and nitric acids with these particles. Chloride depletion is expected to occur upon the liberation of HCI to the gas phase, with the particles remaining enriched in sulfate or nitrate. The elemental ratios of Ca/Na, Mg/Na and K/Na should remain constant during this process. Analysis of chloride depletion and sulfur enrichment was obtained for individual sodium-containing particles from the remote marine Pacific atmosphere in both the accumulation mode (0.06 less-than-or-equal-to Dp less-than-or-equal-to 1.0 mum, where Dp is the particle diameter) and the coarse mode (Dp > 1.0 mum) size range. Sodium-containing particles comprised close to 100% of the coarse mode and 11 to 31% of the accumulation mode by number. Aerosols were collected with a low-pressure impactor and examined with a transmission electron microscope (TEM) coupled with an energy-dispersive X ray (EDX) detector. The elemental ratios obtained from the atmospheric particles were determined by comparison with values obtained from laboratory-generated sea-salt, sodium chloride, and sodium sulfate particles of known size and chemical composition, which served as a calibration set. The elemental ratios of Ca/Na, Mg/Na, and K/Na were found to remain fairly constant between individual sea-salt particles of various sizes for more than 85% of the particles examined. Deviations in the ratio of Cl/Na and S/Na from that of reference seawater values were observed most commonly for the submicrometer sea-salt aerosol. The CI/Na ratio was significantly (Student's t test, 99.9%) lower than that of reference seawater for 89% of the particles examined, while the S/Na ratios were higher for 100% of the particles. The Cl/Na ratio measured in 48% of the coarse sea-salt particles (1.0 < Dp less-than-or-equal-to 2.5 mum) reflected the ratio in bulk seawater, while the remaining particles had statistically lower ratios and qualitatively different morphologies. All but 3% of these coarse particles had enhanced S/Na ratios over that of bulk seawater. Estimates of non-sea-salt (nss) sulfate mass ranged from 216 to 1422 fg for particles of 0.50 mum in diameter to 861 and 5235 fg for particles of 0.80 mum in diameter, corresponding to 74 to 96% of the sea-salt particle mass. These values are compared with the recent measurements of Mouri and Okada [1993] as well as predictions from the atmospheric chemistry models of in-cloud sulfate production of Hegg et al., [19921 and estimations of S(IV) oxidation in sea-salt aerosol water by Chameides and Stelson [1992]. C1 UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEAN, SEATTLE, WA 98195 USA. NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. MCCRONE ASSOCIATES, WESTMONT, IL USA. RP MCINNES, LM (reprint author), UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. RI Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 24 TC 119 Z9 121 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1994 VL 99 IS D4 BP 8257 EP 8268 DI 10.1029/93JD03453 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NH263 UT WOS:A1994NH26300018 ER PT J AU DUTTON, EG REDDY, P RYAN, S DELUISI, JJ AF DUTTON, EG REDDY, P RYAN, S DELUISI, JJ TI FEATURES AND EFFECTS OF AEROSOL OPTICAL DEPTH OBSERVED AT MAUNA-LOA, HAWAII - 1982-1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC TRANSMISSION; EL-CHICHON; DIRECT-SOLAR; MODEL; DISTRIBUTIONS; EXPLOSIONS; TRANSPORT; PINATUBO; CLOUD AB Spectral aerosol optical depth, tau(a), observed at Mauna Loa, Hawaii, for the past 11 years is analyzed for background variations and the effects of two major volcanic eruptions: El Chichon in 1982 and Mount Pinatubo in 1991. A previously known annual variation and near-background levels are present in the record. The data are of high accuracy, being primarily obtained from an automatic precision sunphotometer and reduced using the Langley-plot slope method. The tau(a) values over Mauna Loa were greater immediately after the eruption of El Chichon than after Mount Pinatubo due to more direct transport from El Chichon. However, Pinatubo had a greater temporally integrated impact because of greater erupted sulfur mass. A mean solar irradiance decrease of 6.5 (+/-2. 5) W m-2 per 0.1 tau(a) (500 nm) averaged over 24 hours is observed for both volcanic eruptions. Slight differences are suggested between the eruptions, but the differences are not statistically significant. Small differences between the two eruptions in the aerosol size distributions derived from tau(a) observations are also indicated and are consistent with the suggested difference in total solar irradiance aerosol sensitivity. The near-background tau(a) values compare well with in situ surface-based aerosol light-scattering measurements extrapolated through the upper troposphere. RP DUTTON, EG (reprint author), NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NR 46 TC 100 Z9 101 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1994 VL 99 IS D4 BP 8295 EP 8306 DI 10.1029/93JD03520 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NH263 UT WOS:A1994NH26300021 ER PT J AU DEAKYNE, CA KNUTH, DM SPELLER, CV MEOTNERMAUTNER, M SIECK, LW AF DEAKYNE, CA KNUTH, DM SPELLER, CV MEOTNERMAUTNER, M SIECK, LW TI FILLING OF SOLVENT SHELLS ABOUT IONS .3. ISOMERIC CLUSTERS OF (HCN)N(NH3)MH+ SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article ID GAS-PHASE SOLVATION; PROTON AFFINITIES; BINDING-ENERGIES; MIXED CLUSTERS; HYDROGEN-BOND; AMMONIUM ION; COMPLEXES; NH3; DECOMPOSITIONS; STABILITIES AB Clustering enthalpies of (HCN)n(NH3)(m)H+ ions have been studied via high pressure mass spectrometry and ab initio calculations. Fully optimized geometries have been obtained for n + m less-than-or-equal-to 5 at the HF/6-31G* level of calculation. Five isomeric forms of the (HCN)n(NH3)(m)H+ ions have been considered. All of the complexes were found to contain an NH4+ core ion. One isomer has all of the ligands bound to the NH4+ ion whereas the other four have one of the ligands bound to another ligand. The former isomer is the most stable for all clusters; however, the latter isomers containing an NCH...NH3 or an NCH...NCH hydrogen bond become competitive in stability as n + m increases. MP2/6-31 +G(2d,2p)//HF/6-3 IG* stabilization enthalpies adjusted for BSSE have been compared to the experimental values. With two exceptions the values agree to within +/- 6 kJ mol-1. The agreement between the calculated and experimental DELTAS-degrees and DELTAG-degrees values is less good at +/- 27 J K-1 mol-1 and +/- 12 kJ mol-1, respectively. The smooth decrease with n in the plot of -DELTAH(n-1,n)-degrees vs. n for (HCN)n(NH3)H+ and the ab initio results for (HCN)n(NH3)H+ and (HCN)(NH3)(m)H+ suggest that mixtures of isomeric clusters may be present at equilibrium when n and m are greater-than-or-equal-to 4. C1 NATL INST STAND & TECHNOL, CHEM KINET & THERMODYNAM, GAITHERSBURG, MD 20876 USA. UNIV MISSOURI, DEPT CHEM, COLUMBIA, MO 65211 USA. RP EASTERN ILLINOIS UNIV, DEPT CHEM, CHARLESTON, IL 61920 USA. NR 47 TC 4 Z9 4 U1 0 U2 0 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 APR 20 PY 1994 VL 113 BP 217 EP 238 PG 22 WC Chemistry, Physical SC Chemistry GA NJ872 UT WOS:A1994NJ87200021 ER PT J AU KUMAR, A GALLAWA, RL AF KUMAR, A GALLAWA, RL TI BENT RECTANGULAR CORE WAVE-GUIDES - AN ACCURATE PERTURBATION APPROACH SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE DIELECTRIC WAVE-GUIDE; CORE WAVE-GUIDE; OPTICAL FIBER; PERTURBATION METHOD AB We discuss a method of evaluating the effective indices of quasi-modes of a bent rectangular core waveguide taking into account the correct dielectric constant of the corner regions, which is ignored in earlier methods. At small bend curvatures and low V values, the corner regions contribute much more to the effective index change than the bending itself. (C) 1994 John Wiley & Sons, Inc. RP KUMAR, A (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD APR 20 PY 1994 VL 7 IS 6 BP 281 EP 285 DI 10.1002/mop.4650070609 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA NC882 UT WOS:A1994NC88200008 ER PT J AU KRAUSS, M AF KRAUSS, M TI THE ELECTRONIC EXCITED-STATES OF THE H-BONDED COMPLEX OF THE PHENOL CATION AND WATER SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article ID RAMAN-SPECTRUM; PHOTOELECTRON-SPECTROSCOPY; BENZYL; RADICALS AB Complete active space multireference first-order configuration interaction (FOCI) calculations are use to determine the excitation energies of organic radicals. Application is made to the analysis of the effect of H-bonded interactions on the spectra of the phenoxyl radical and the phenol cation. Although earlier tests have been successful, the FOCI excitation energies of the benzyl radical, which is isoelectronic with phenoxyl, is compared to both experiment and earlier multiconfiguration self-consistent field (MCSCF) values providing additional corroboration of the accuracy of FOCI methods. The well-known 398 nm transition in the pheoxyl radical is represented well by the FOCI calculation. Two additional lower energy transitions are also predicted. The transition at 461 nm in vacuo is assigned to a broad experimental fluorescence band observed in the 425 nm region. No spectrum of the phenol cation has been reported. A broad transition around 373 nm has been attributed to the phenol cation complex with a single water molecule. Shifts in, the spectra of the phenol cation and phenoxyl complexes relevant to the analysis of this transition are calculated to be of the order of 500 cm-1. This result supports the spectral assignment to the phenol cation complex and the conclusion that proton transfer does not occur in the ground state of this complex. RP KRAUSS, M (reprint author), NAT INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 23 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD APR 20 PY 1994 VL 113 BP 47 EP 54 PG 8 WC Chemistry, Physical SC Chemistry GA NJ872 UT WOS:A1994NJ87200007 ER PT J AU GALLAGHER, T ALEXANDER, P BRYAN, P GILLILAND, GL AF GALLAGHER, T ALEXANDER, P BRYAN, P GILLILAND, GL TI 2 CRYSTAL-STRUCTURES OF THE B1 IMMUNOGLOBULIN-BINDING DOMAIN OF STREPTOCOCCAL PROTEIN-G AND COMPARISON WITH NMR SO BIOCHEMISTRY LA English DT Article ID LEAST-SQUARES REFINEMENT; B2 AB The structure of the 56-residue B1 immunoglobulin-binding domain from streptococcal protein G has been determined in two different crystal forms. The crystal structures were deduced by molecular replacement, based on the structure of the B2 domain (Brookhaven accession code 1PGX). Final R values are 0.174 and 0.198 for orthorhombic and trigonal forms, for diffraction data from 6.0 to 2.07 Angstrom and from 6 to 1.92 Angstrom, respectively. The orthorhombic crystals have an unusually high packing density for protein crystals, with V-m = 1.66 and a solvent content of 26%. The protein structure is found to be very similar (rms deviation 0.25 Angstrom for 56 C alpha's) in the two crystal forms, with an efficiently packed hydrophobic core between a four-stranded beta-sheet and a four-turn alpha-helix. The B1 domain has the same fold and general structure as the B2 domain (rms deviations 0.36 and 0.39 Angstrom), despite the six residue differences between them. The crystallographic models differ from NMR-derived models in several local regions, primarily in the loop involving residues 46-51; other significant variations are observed in the helix and in the structure of bound water. The primary crystal contact is the same in both crystal forms, involving both sheet edges to form extended beta-sheets throughout the crystals. C1 NATL INST STAND & TECHNOL,ROCKVILLE,MD 20850. RP GALLAGHER, T (reprint author), UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 24 TC 297 Z9 300 U1 2 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 19 PY 1994 VL 33 IS 15 BP 4721 EP 4729 DI 10.1021/bi00181a032 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA NH493 UT WOS:A1994NH49300036 PM 8161530 ER PT J AU CHEN, H MILDNER, DFR XIAO, QF AF CHEN, H MILDNER, DFR XIAO, QF TI NEUTRON FOCUSING LENS USING POLYCAPILLARY FIBERS SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICS AB Multiple mirror reflection at small grazing angles from the smooth surfaces of the narrow channels of polycapillary fibers can be used to transport, bend, and focus thermal neutron beams. We report the results of the focusing of a polychromatic cold neutron beam using a compact lens of borosilicate fibers and with a focal distance of 57 mm. The intensity profile of the beam at the focus is approximately conical in shape with a full width at half-maximum of 0.49 mm, and with an average gain in intensity of about 20. These experimental results agree well with those obtained by computer simulation. C1 X-RAY OPT SYST INC,ALBANY,NY 12222. RP CHEN, H (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 17 TC 11 Z9 11 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 18 PY 1994 VL 64 IS 16 BP 2068 EP 2070 DI 10.1063/1.111709 PG 3 WC Physics, Applied SC Physics GA NG495 UT WOS:A1994NG49500008 ER PT J AU BOOI, PAA BENZ, SP AF BOOI, PAA BENZ, SP TI EMISSION LINEWIDTH MEASUREMENTS OF 2-DIMENSIONAL ARRAY JOSEPHSON OSCILLATORS SO APPLIED PHYSICS LETTERS LA English DT Article ID JUNCTION ARRAYS AB We have coupled emission from 10 X 10 arrays of Josephson junctions at 4 K to a room-temperature mixer through a fin-line antenna and a WR-12 waveguide. A single voltage-tunable peak was detected in the frequency range from 53 to 230 GHz. A stripline resonance in the antenna reduced the array's dynamic resistance and thereby the emission linewidth to as low as 10 kHz. We extract an effective noise temperature of 14 K from the linewidth data. RP BOOI, PAA (reprint author), NATL INST STAND & TECHNOL,DIV 81403,325 BROADWAY,BOULDER,CO 80303, USA. NR 15 TC 53 Z9 54 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 18 PY 1994 VL 64 IS 16 BP 2163 EP 2165 DI 10.1063/1.111984 PG 3 WC Physics, Applied SC Physics GA NG495 UT WOS:A1994NG49500041 ER PT J AU PANDEY, PC WEETALL, HH AF PANDEY, PC WEETALL, HH TI APPLICATION OF PHOTOCHEMICAL-REACTION IN ELECTROCHEMICAL DETECTION OF DNA INTERCALATION SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; FLOW-INJECTION ANALYSIS; ETHIDIUM; KINETICS AB A flow injection analysis (FIA) system for the detection of the compounds that intercalate within DNA is reported. A derivative of 9,10-anthraquinone has been used as the reference compound for photoelectrochemical detection. The sodium salts of 9,10-anthraquinone-2,6-disulfonic acid and 9,10-anthraquinone-2-sulfonic acid are photochemically activated and then reduced in the presence of an electron donor (glucose). The electrochemical signal is based on the measurement of the anodic current resulting from the oxidation of the reduced form of 9,10-anthraquinone. The reduced form of the 9,10-anthraquinone is oxidized through a mediated mechanism at the surface of a tetracyanoquinodimethane-(TCNQ)-modified graphite paste electrode covered by a Nucleopore membrane. TCNQ acts as an efficient mediator for the oxidation of reduced 9,10-anthraquinone. Cyclic voltammetry, photocyclic voltammetry, and the photoelectrochemical FIA response of 9,10-anthraquinone are reported, Experimental results show that these anthraquinones can be intercalated within the helix of double-stranded calf thymus DNA. The anthraquinone molecules that are intercalated within DNA cannot be oxidized due to their limited transport to the modified electrode surface. This results in a decrease in the anodic current at a constant concentration of anthraquinone after intercalation. There is a linear relation between the decrease in electrochemical response and the DNA concentration at a constant concentration of anthraquinone. The intercalated anthraquinone molecules can be completely replaced by another intercalating agent (i.e., ethidium bromide) that is more strongly intercalated within DNA, thereby regenerating the electrochemical response. The calibration curve for the analysis of this compound is reported. C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 35 TC 57 Z9 59 U1 7 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 15 PY 1994 VL 66 IS 8 BP 1236 EP 1241 DI 10.1021/ac00080a007 PG 6 WC Chemistry, Analytical SC Chemistry GA NF411 UT WOS:A1994NF41100010 PM 8210041 ER PT J AU OORT, AH ANDERSON, LA PEIXOTO, JP AF OORT, AH ANDERSON, LA PEIXOTO, JP TI ESTIMATES OF THE ENERGY CYCLE OF THE OCEANS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID AVAILABLE POTENTIAL-ENERGY; NORTH-ATLANTIC; WORLD OCEAN; WIND STRESS; MODEL; SENSITIVITY; MASS AB A new formulation of the general problem of the large-scale energetics for the global oceans is presented and analyzed. Using a variety of ocean surface observations, some of the terms in the energy balance equations, such as the time rates of change, the generation rates of available gravitational potential energy G(P) and kinetic energy G(K), and the conversion rate from available gravitational potential energy into kinetic energy C(P, K), are estimated for annual and seasonal mean conditions. An attempt is also made to measure the uncertainty of these terms in order to assess the reliability of the results. The interseasonal variability is analyzed showing that the winter hemisphere represents the most active region of the globe. Using the data and some reasonable assumptions, pictures of the energy cycle in the global oceans for yearly and seasonal conditions are constructed. The hemispheric and global dissipation rates of available gravitational potential energy D(P) and of kinetic energy D(K) are estimated as residuals, assuming that the contribution from the internal energy C(I, K) is only a minor factor. After analyzing the general consistency of the picture of the energy cycle for the oceans, the conclusion is reached that the G(P) and G(K) terms are about equally important terms needed to describe and understand the structure and dynamics of the global ocean circulation. C1 HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. INST GEOFIS INFANTE D LUIS,P-581200 LISBON,PORTUGAL. RP OORT, AH (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 23 TC 56 Z9 56 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1994 VL 99 IS C4 BP 7665 EP 7688 DI 10.1029/93JC03556 PG 24 WC Oceanography SC Oceanography GA NG710 UT WOS:A1994NG71000028 ER PT J AU JOHNSON, ES LUTHER, DS AF JOHNSON, ES LUTHER, DS TI MEAN ZONAL MOMENTUM BALANCE IN THE UPPER AND CENTRAL EQUATORIAL PACIFIC-OCEAN SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TAHITI SHUTTLE EXPERIMENT; TROPICAL PACIFIC; INTERNAL WAVES; UNDERCURRENT; TURBULENCE; ATLANTIC; PARAMETERIZATION; CIRCULATION; VARIABILITY; CURRENTS AB We examine the mean zonal momentum balance in the tropical mid-Pacific using a year of acoustic Doppler current profiler velocities and conductivity-temperature-depth profiler densities from the Hawaii-to-Tahiti Shuttle Experiment. All significant contributions from the mean, annual cycle, and higher-frequency flow fields are determined with the exception of the vertical stresses. We find that even neglecting vertical stresses, the zonal momentum equation is in rough balance at 90-117-m depth at all latitudes from 4-degrees-S to 10-degrees-N. While the formal error bars are large, this rough balance is reproducible over four to five independent latitudes and so is probably real. The balance at 90-m depth is geostrophic to within 5-degrees of the equator. Closer to the equator, meridional mean convergence and meridional eddy stresses contribute important forces to balance the mean pressure gradient. Nearer the surface, the zonal momentum equation is dominated by eastward pressure gradients near the equator and eastward Coriolis forces from a strong, northward Ekman flow poleward of 2-degrees-N. In the vertical integral these forces roughly balance the surface wind stress; thus vertical stresses suffice to close our momentum budget. We conclude that on average vertical stresses arising from the wind forcing do not penetrate deeper than 90 m into the tropical ocean. This contradicts an earlier study of the equatorial zonal momentum budget but is consistent with turbulent dissipation measurements on the equator. Previous findings of stronger, deeper dissipation on the equator are probably due to the stronger, deeper mean shear there rather than to a locally altered stress profile. Vertical turbulent viscosities derived from our observations agree with previous observations on the equator but contradict the conventional, Richardson number parameterization off the equator. C1 UNIV HAWAII,SCH OCEAN & EARTH SCI & TECHNOL,HONOLULU,HI 96822. RP JOHNSON, ES (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 37 TC 41 Z9 41 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1994 VL 99 IS C4 BP 7689 EP 7705 DI 10.1029/94JC00033 PG 17 WC Oceanography SC Oceanography GA NG710 UT WOS:A1994NG71000029 ER PT J AU BATES, TS KIENE, RP WOLFE, GV MATRAI, PA CHAVEZ, FP BUCK, KR BLOMQUIST, BW CUHEL, RL AF BATES, TS KIENE, RP WOLFE, GV MATRAI, PA CHAVEZ, FP BUCK, KR BLOMQUIST, BW CUHEL, RL TI THE CYCLING OF SULFUR IN SURFACE SEAWATER OF THE NORTHEAST PACIFIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID DIMETHYL SULFIDE PRODUCTION; DIMETHYLSULFONIUM PROPIONATE; OCEANIC DIMETHYLSULFIDE; SEASONAL-VARIATIONS; ATMOSPHERIC SULFUR; EQUATORIAL PACIFIC; COASTAL WATERS; CLOUD ALBEDO; SEA-WATER; PHYTOPLANKTON AB Oceanic dimethylsulfide (DMS) emissions to the atmosphere are potentially important to the Earth's radiative balance. Since these emissions are driven by the surface seawater concentration of DMS, it is important to understand the processes controlling the cycling of sulfur in surface seawater. During the third Pacific Sulfur/Stratus Investigation (PSI-3, April 1991) we measured the major sulfur reservoirs (total organic sulfur, total low molecular weight organic sulfur, ester sulfate, protein sulfur, dimethylsulfoniopropionate (DMSP), DMS, dimethylsulfoxide) and quantified many of the processes that cycle sulfur through the upper water column (sulfate assimilation, DMSP consumption, DMS production and consumption, air-sea exchange of DMS, loss of organic sulfur by particulate sinking). Under conditions of low plankton biomass (<0.4 mug/L chlorophyll a) and high nutrient concentrations (>8 muM nitrate), 250 km off the Washington State coast, DMSP and DMS were 22% and 0.9%, respectively, of the total particulate organic sulfur pool. DMS production from the enzymatic cleavage of DMSP accounted for 29% of the total sulfate assimilation. However, only 0.3% of sulfate-S assimilated was released to the atmosphere. From these data it is evident that air-sea exchange is currently only a minor sink in the seawater sulfur cycle and thus there is the potential for much higher DMS emissions under different climatic conditions. C1 DREXEL UNIV,DEPT CHEM,PHILADELPHIA,PA 19104. UNIV WISCONSIN MILWAUKEE,CTR GREAT LAKES STUDIES,MILWAUKEE,WI 53204. UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,SEATTLE,WA 98195. UNIV GEORGIA,INST MARINE,SAPELO ISL,GA. MONTEREY BAY AQUARIUM RES INST,PACIFIC GROVE,CA 93950. RP BATES, TS (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Bates, Timothy/L-6080-2016 NR 56 TC 136 Z9 140 U1 2 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1994 VL 99 IS C4 BP 7835 EP 7843 DI 10.1029/93JC02782 PG 9 WC Oceanography SC Oceanography GA NG710 UT WOS:A1994NG71000038 ER PT J AU KELECY, TM BORN, GH PARKE, ME ROCKEN, C AF KELECY, TM BORN, GH PARKE, ME ROCKEN, C TI PRECISE MEAN SEA-LEVEL MEASUREMENTS USING THE GLOBAL POSITIONING SYSTEM SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID AMBIGUITY AB This paper describes the results of a sea level measurement test conducted off La Jolla, California, in November of 1991. The purpose of this test was to determine accurate sea level measurements using a Global Positioning System (GPS) equipped buoy. These measurements were intended to be used as the sea level component for calibration of the ERS 1 satellite altimeter. Measurements were collected on November 25 and 28 when the ERS 1 satellite overflew the calibration area. Two different types of buoys were used. A waverider design was used on November 25 and a spar design on November 28. This provided the opportunity to examine how dynamic effects of the measurement platform might affect the sea level accuracy. The two buoys were deployed at locations approximately 1.2 km apart and about 15 km west of a reference GPS receiver located on the rooftop of the Institute of Geophysics and Planetary Physics at the Scripps Institute of Oceanography. GPS solutions were computed for 45 minutes on each day and used to produce two sea level time series. An estimate of the mean sea level at both locations was computed by subtracting tide gage data collected at the Scripps Pier from the GPS-determined sea level measurements and then filtering out the high-frequency components due to waves and buoy dynamics. In both cases the GPS estimate differed from Rapp's mean altimetric surface by 0.06 m. Thus the gradient in the GPS measurements matched the gradient in Rapp's surface. These results suggest that accurate sea level can be determined using GPS on widely differing platforms as long as care is taken to determine the height of the GPS antenna phase center above water level. Application areas include measurement of absolute sea level, of temporal variations in sea level, and of sea level gradients (dominantly the geoid). Specific applications would include ocean altimeter calibration, monitoring of sea level in remote regions, and regional experiments requiring spatial and temporal resolution higher than that available from altimeter data. C1 UNIV COLORADO,COLORADO CTR ASTRODYNAM RES,BOULDER,CO 80309. UNIV COLORADO,UNIV CORP ATMOSPHER RES,UNIV NAVSTAR CONSORTIUM,BOULDER,CO 80303. NOAA,OFF OCEAN & EARTH SCI,SILVER SPRING,MD 20910. NR 9 TC 17 Z9 19 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1994 VL 99 IS C4 BP 7951 EP 7959 DI 10.1029/93JC03355 PG 9 WC Oceanography SC Oceanography GA NG710 UT WOS:A1994NG71000047 ER PT J AU HARLAN, JA GEORGES, TM AF HARLAN, JA GEORGES, TM TI AN EMPIRICAL RELATION BETWEEN OCEAN-SURFACE WIND DIRECTION AND THE BRAGG LINE RATIO OF HF RADAR SEA ECHO SPECTRA SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SKYWAVE RADAR; HORIZON; WAVES AB Twelve days of tests with six U.S. Air Force OTH-B over-the-horizon radars produced a large surface wind direction data set covering much of the North Atlantic and Pacific oceans. We compare wind directions derived from the sea echo Bragg line ratio with concurrent in situ measurements made by ships and buoys and with the National Meteorological Center (NMC) Global Data Assimilation System model. Using 1900 such comparisons, we derive an empirical model for the dependence of surface wind direction on the Bragg line ratio of HF radar sea echoes. The rms difference between the empirical model and the combined NMC and in situ data is about 33-degrees. When only very high quality radar data are used, the rms difference between the radar and buoy measurements alone is 24-degrees. The pattern of surface streamlines derived from 1 day's radar measurements over the northeastern Pacific Ocean closely matches that derived from the NMC model. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. RP HARLAN, JA (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 31 TC 17 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1994 VL 99 IS C4 BP 7971 EP 7978 DI 10.1029/93JC03560 PG 8 WC Oceanography SC Oceanography GA NG710 UT WOS:A1994NG71000049 ER PT J AU COOK, RF BRAUN, LM CANNON, WR AF COOK, RF BRAUN, LM CANNON, WR TI TRAPPED CRACKS AT INDENTATIONS .1. EXPERIMENTS ON YTTRIA TETRAGONAL ZIRCONIA POLYCRYSTALS SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID TRANSFORMATION-TOUGHENED ZIRCONIA; PARTIALLY-STABILIZED ZIRCONIA; GRAIN-SIZE DEPENDENCE; FRACTURE-TOUGHNESS; MECHANICAL-PROPERTIES; SINGLE-CRYSTALS; TZP CERAMICS; DEFORMATION AB Indentation radial cracking has been examined in a series of yttria-tetragonal zirconia polycrystals (Y-TZP) with a range of grain sizes. For all materials, two distinct types of cracks were found to exist. Above a threshold indentation load, short cracks of variable length were observed, ''trapped'' in a compressive, contact-induced transformation zone. Above a second threshold, longer, ''well-developed'' cracks of more consistent length formed, extending beyond the zone boundary. The stochastic nature of the formation of both types of cracks, and the existence of the transformation zone in general, generate many artefacts in toughness estimates made using unmodified indentation fracture mechanics analyses. C1 NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RUTGERS STATE UNIV,DEPT CERAM ENGN,PISCATAWAY,NJ 08855. RP COOK, RF (reprint author), IBM CORP,DIV RES,T J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. NR 40 TC 21 Z9 21 U1 0 U2 1 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 15 PY 1994 VL 29 IS 8 BP 2133 EP 2142 DI 10.1007/BF01154691 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA NJ064 UT WOS:A1994NJ06400021 ER PT J AU COOK, RF BRAUN, LM AF COOK, RF BRAUN, LM TI TRAPPED CRACKS AT INDENTATIONS .2. FRACTURE-MECHANICS MODEL SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ELASTIC-PLASTIC INDENTATION; SODA-LIME GLASS; PHASE-TRANSFORMATION; STABILIZED ZIRCONIA; INITIATION; TOUGHNESS; CERAMICS; SOLIDS; DEFORMATION; NUCLEATION AB A fracture-mechanics model for indentation cracking in phase-transforming materials is developed, based on the competing interaction of the tensile residual-mismatch field and the compressive contact-induced transformation field. In addition to the usual subthreshold and well-developed cracking ranges, the model predicts the trapping of cracks at indentations, within the transformation zone. As an example, the model is used to describe the dependence of radial crack length on indentation load in a range of yttria-tetragonal zirconia polycrystals (Y-TZP), explicitly addressing the trapping behaviour observed in Part I. The crucial parameters of the model obtained from the experimental fits, the size of the transformation zone relative to the contact impression, b/a, and the magnitude of the transformation stress relative to the hardness, sigma(T)/H, agree with independent measurements. Although applied to phase-transforming materials here, the principles of the model are generally applicable to systems with short-range, compensating stress fields competing with longer-ranged, dominant fields, leading to two discrete crack populations. C1 NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RP COOK, RF (reprint author), IBM CORP, DIV RES, T J WATSON RES CTR, YORKTOWN HTS, NY 10598 USA. NR 40 TC 10 Z9 10 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD APR 15 PY 1994 VL 29 IS 8 BP 2192 EP 2204 DI 10.1007/BF01154700 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA NJ064 UT WOS:A1994NJ06400030 ER PT J AU LIU, XD BRIBER, RM BAUER, BJ AF LIU, XD BRIBER, RM BAUER, BJ TI ELECTRON-BEAM CROSS-LINKING OF POLY(VINYLMETHYL ETHER) SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE RADIATION; ELECTRON BEAM; POLY(VINYLMETHYL ETHER); CROSS-LINKING; BRANCHING; CHARACTERIZATION; GEL PERMEATION CHROMATOGRAPHY; NETWORK AB The electron beam induced branching of poly (vinylmethyl ether) (PVME) in bulk and in isopropanol solutions has been studied by gel permeation chromatography. The branching probability of bulk PVME induced by high-energy electrons can be characterized by gel permeation chromatography and a simple probability constant obtained. In isopropanol solutions this branching probability is not constant as a function of dose and is found to decrease with decreasing concentration. These results indicate the importance of solvent effects on the crosslinking of PVME in isopropanol solution by electron beam radiation. (C) 1994 John Wiley & Sons, Inc. C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLL PK,MD 20742. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 11 TC 6 Z9 6 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD APR 15 PY 1994 VL 32 IS 5 BP 811 EP 815 DI 10.1002/polb.1994.090320504 PG 5 WC Polymer Science SC Polymer Science GA NA335 UT WOS:A1994NA33500004 ER PT J AU WANG, XL AF WANG, XL TI THE COUPLING OF THE ANNUAL CYCLE AND ENSO OVER THE TROPICAL PACIFIC SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN OSCILLATION; EL-NINO; SEASONAL CYCLE; OCEAN; VARIABILITY; ATMOSPHERE; FIELDS AB In the tropical Pacific, the annual variation of sea surface temperature (SST) consists of two distinct components with respect to the equator, 1) an antisymmetric extratropical annual cycle and 2) a symmetric equatorial annual cycle (SEAC). The former, explaining about 70% of SST variance on average, is primarily a delayed response to the solar radiation, while the latter, accounting for about 15% of total SST variance, is a result of equatorial ocean-atmosphere interaction. The antisymmetric extratropical annual cycle does not interact directly with the El Nino-Southern Oscillation (ENSO). However, the symmetric equatorial annual cycle is mutually coupled with ENSO evolution, and the artificial separation between the two can result in a distorted description of some ENSO characteristics. The SEAC-ENSO coupling involves at least two modes. One mode represents the equatorial eastern Pacific with an apparent phase evolution corresponding to the annual development of the cold tongue regime. In this mode, about half of the local interannual variance is modulated by the annual cycle, and the most preferable modulation occurs around later winter-early spring. The other mode is a standing SST pattern concentrated in the central Pacific. About one-third of the local interannual variance is directly projected on the mean annual cycle with a maximum strength in later northern summer to early fall. RP WANG, XL (reprint author), NOAA,NWS,NMC,CTR CLIMATE ANAL,W NMC52,WASHINGTON,DC 20233, USA. RI Wang, Julian/C-3188-2016 NR 29 TC 17 Z9 18 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 15 PY 1994 VL 51 IS 8 BP 1115 EP 1136 DI 10.1175/1520-0469(1994)051<1115:TCOTAC>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NJ888 UT WOS:A1994NJ88800007 ER PT J AU FENG, YP MAJKRZAK, CF SINHA, SK WIESLER, DG ZHANG, H DECKMAN, HW AF FENG, YP MAJKRZAK, CF SINHA, SK WIESLER, DG ZHANG, H DECKMAN, HW TI DIRECT OBSERVATION OF NEUTRON-GUIDED WAVES IN A THIN-FILM WAVE-GUIDE SO PHYSICAL REVIEW B LA English DT Note AB Guided propagation of neutrons in thin films was directly observed in a TiO2/Ti/Si waveguide by exciting one of its discrete guided modes from an external neutron beam. The condition found experimentally for exciting this particular mode agrees well with theory. The measured intensity of the guided neutrons was also in good agreement with a calculation based on a previous coupling theory. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP FENG, YP (reprint author), EXXON RES & ENGN CO,ANNANDALE,NJ 08801, USA. NR 11 TC 36 Z9 37 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 APR 15 PY 1994 VL 49 IS 15 BP 10814 EP 10817 DI 10.1103/PhysRevB.49.10814 PG 4 WC Physics, Condensed Matter SC Physics GA NJ756 UT WOS:A1994NJ75600101 ER PT J AU WANG, L HAEGEL, NM LOWNEY, JR AF WANG, L HAEGEL, NM LOWNEY, JR TI BAND-TO-BAND PHOTOLUMINESCENCE AND LUMINESCENCE EXCITATION IN EXTREMELY HEAVILY CARBON-DOPED EPITAXIAL GAAS SO PHYSICAL REVIEW B LA English DT Article ID P-TYPE GAAS; MOLECULAR-BEAM EPITAXY; GALLIUM-ARSENIDE; N-TYPE; CONCENTRATION-DEPENDENCE; PHOTO-LUMINESCENCE; IMPURITY BANDS; GAP; ABSORPTION; SEMICONDUCTORS AB Heavily carbon-doped GaAs samples with doping levels as high as 4.1 X 10(20) cm-3 were studied by photoluminescence and luminescence excitation spectroscopies. Luminescence and absorption band gaps were determined, from which the positions of the Fermi levels were deduced. A variety of factors which affect the observed emission spectra, including diffraction and refraction of the luminescence, substrate effects, and lattice contraction in the carbon-doped epilayer, were examined. A first-principles calculation was performed to calculate the density of states, the band pp, the Fermi energy, and the emission spectrum. Comparison of the calculation results with the experiments shows that the theoretical model we use is a good approximation for describing band structure for doping levels higher than 10(20) cm-3. However, the discrepancy between the measured and the calculated emission spectra indicates that the usual assumptions such as constant momentum matrix elements and quasiequilibrium distribution of photoexcited electrons in the conduction band may not be appropriate in treating the transition processes in highly degenerate semiconductors. C1 NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899. RP WANG, L (reprint author), UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90024, USA. NR 40 TC 6 Z9 6 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1994 VL 49 IS 16 BP 10976 EP 10985 DI 10.1103/PhysRevB.49.10976 PG 10 WC Physics, Condensed Matter SC Physics GA NK063 UT WOS:A1994NK06300014 ER PT J AU REKHARSKY, MV SCHWARZ, FP TEWARI, YB GOLDBERG, RN TANAKA, M YAMASHOJI, Y AF REKHARSKY, MV SCHWARZ, FP TEWARI, YB GOLDBERG, RN TANAKA, M YAMASHOJI, Y TI THERMODYNAMIC AND NMR-STUDY OF THE INTERACTIONS OF CYCLODEXTRINS WITH CYCLOHEXANE DERIVATIVES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ALPHA-CYCLODEXTRIN; AQUEOUS-SOLUTION; COMPLEX-FORMATION; INCLUSION-COMPOUNDS; BINDING CONSTANTS; TITRATION; STABILITY; 298.15-K; ALCOHOLS; PHENOLS AB Equilibrium constants and standard molar enthalpies of reaction have been determined by titration calorimetry for a series of cyclohexane derivatives (cis-1,2-cyclohexanediol, cis,cis-1,3,5-cyclohexanetriol, trans-1,2-cyclohexanediol, cyclohexanol, cyclohexanone, 2-methylcyclohexanone, 2,5-piperazinedione, and delta-valerolactam) with alpha-cyclodextrin and beta-cyclodextrin. For the reactions involving cyclohexanol, standard molar heat-capacity changes were also determined from calorimetric measurements performed at several temperatures. The equilibrium constants for the reactions of these substances with beta-cyclodextrin are in all cases larger than those for the corresponding reactions with alpha-cyclodextrin. It was also found that the equilibrium constants for the reactions of these substances with gamma-cyclodextrin were too small (<4) to measure with this method. An important feature of these reactions is that while the standard molar enthalpies of reaction are approximately the same for both cyclodextrins, the standard molar entropy changes for the reactions of these substances with beta-cyclodextrin are substantially more positive than for the reactions with alpha-cyclodextrin. The hydrophilic nature of the groups on the cyclohexane ring as well as steric effects was found to influence the thermodynamics of these reactions. The standard molar enthalpy of transfer of the cyclohexane derivatives from the alpha-cyclodextrin complex to the beta-cyclodextrin complex was found to be a linear function of the standard molar entropy change for this same transfer reaction. NMR results indicate that while the proximity of these cyclohexane derivatives to the walls of the alpha-cyclodextrin and that to the walls of the beta-cyclodextrin are comparable, the cyclohexane derivatives penetrate deeper into the larger beta-cyclodextrin cavity than into the smaller alpha-cyclodextrin cavity. C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. OSAKA UNIV,FAC ENGN,DEPT APPL CHEM,SUITA,OSAKA 565,JAPAN. NR 28 TC 83 Z9 84 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 14 PY 1994 VL 98 IS 15 BP 4098 EP 4103 DI 10.1021/j100066a032 PG 6 WC Chemistry, Physical SC Chemistry GA NG219 UT WOS:A1994NG21900032 ER PT J AU PENG, YG TAYLOR, TB FINCH, RE SWITZER, RC RAMSDELL, JS AF PENG, YG TAYLOR, TB FINCH, RE SWITZER, RC RAMSDELL, JS TI NEUROEXCITATORY AND NEUROTOXIC ACTIONS OF THE AMNESIC SHELLFISH POISON, DOMOIC ACID SO NEUROREPORT LA English DT Article DE DOMOIC ACID; C-FOS; NEURODEGENERATION; TOXIN; HIPPOCAMPUS; SOLITARIS ID KAINIC ACID; HIPPOCAMPAL DAMAGE; INDUCED SEIZURES; RAT-BRAIN; MUSSELS; FOS; NEURODEGENERATION; EXPRESSION; MICE AB WE have investigated the action of domoic acid in the mouse brain following systemic exposure. Domoic acid increased c-fos mRNA within 15 min and its translational product (c-Fos) within 1 h. c-Fos immunoreactivity was most prominent in the hippocampal formation, lateral septal nucleus, olfactory bulb, area postrema and the nucleus of the solitary tract. We next examined irreversible toxic effects of domoic acid. Domoic acid caused extensive degeneration in CA1-2 of the hippocampus, lateral septal nucleus and olfactory bulb. No degeneration was evident in the dentate gyrus or brain stem. These studies demonstrate that domoic acid has only neuroexcitatory effects on brain stem regions associated with visceral function whereas it has permanent neurotoxic effects on brain regions associated with memory formation. C1 NATL MARINE FISHERIES SERV,MARINE BIOTOXINS PROGRAM,CHARLESTON,SC 29412. MED UNIV S CAROLINA,CHARLESTON,SC 29412. NEUROSCI ASSOCIATES,KNOXVILLE,TN. FU NIDDK NIH HHS [DK 43107] NR 25 TC 65 Z9 71 U1 0 U2 3 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0959-4965 J9 NEUROREPORT JI Neuroreport PD APR 14 PY 1994 VL 5 IS 8 BP 981 EP 985 DI 10.1097/00001756-199404000-00032 PG 5 WC Neurosciences SC Neurosciences & Neurology GA NK709 UT WOS:A1994NK70900032 PM 8061308 ER PT J AU HAMMOUDA, B BAUER, BJ RUSSELL, TP AF HAMMOUDA, B BAUER, BJ RUSSELL, TP TI SMALL-ANGLE NEUTRON-SCATTERING FROM DEUTERATED POLYSTYRENE POLY(BUTYL METHACRYLATE) HOMOPOLYMER BLEND MIXTURES SO MACROMOLECULES LA English DT Article ID POLYVINYL METHYL-ETHER); POLYMER BLENDS; THERMODYNAMICS; MISCIBILITY; DIMENSIONS; DYNAMICS C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. IBM RES, ALMADEN RES CTR, SAN JOSE, CA 95120 USA. RP HAMMOUDA, B (reprint author), NATL INST STAND & TECHNOL, BLDG 235 E151, GAITHERSBURG, MD 20899 USA. NR 23 TC 28 Z9 28 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 11 PY 1994 VL 27 IS 8 BP 2357 EP 2359 DI 10.1021/ma00086a065 PG 3 WC Polymer Science SC Polymer Science GA NF810 UT WOS:A1994NF81000065 ER PT J AU OSSADNIK, P GYURE, MF STANLEY, HE GLOTZER, SC AF OSSADNIK, P GYURE, MF STANLEY, HE GLOTZER, SC TI MOLECULAR-DYNAMICS SIMULATION OF SPINODAL DECOMPOSITION IN A 2-DIMENSIONAL BINARY-FLUID MIXTURE SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 NATL INST STANDARDS & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RP OSSADNIK, P (reprint author), BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215, USA. NR 3 TC 36 Z9 36 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 APR 11 PY 1994 VL 72 IS 15 BP 2498 EP 2498 DI 10.1103/PhysRevLett.72.2498 PG 1 WC Physics, Multidisciplinary SC Physics GA NE851 UT WOS:A1994NE85100048 ER PT J AU BASKO, M AF BASKO, M TI NICKEL BUBBLE INSTABILITY AND MIXING IN SN-1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; INSTABILITIES; NUCLEAR REACTIONS, NUCLEOSYNTHESIS, ABUNDANCES; STARS, INDIVIDUAL (SN-1987A); STARS, INTERIORS ID RAYLEIGH-TAYLOR INSTABILITY; SUPERNOVA 1987A; HYDRODYNAMIC INSTABILITIES; EARLY EVOLUTION; LINE-PROFILES; SN 1987A; X-RAYS; FE-II; DIMENSIONS; EMISSION AB At least three stages where dynamical instabilities can cause macroscopic mixing have been identified in the hydrodynamics of SN 1987A. With a specific aim to investigate the mixing of Ni-56, we consider the latest stage which occurs in nickel bubbles inflated by heating due to the Ni-56 --> Co-56 --> Fe-56 radioactive decays. One-dimensional hydrodynamics simulations show that a snowplowed shell around each inflating blob of Ni-56 is Rayleigh-Taylor unstable and, after t congruent-to 3-5 days, should be broken and mixed into the expanding nickel in the form of O-C-He-H clumps. To evaluate the additional acceleration of nickel resulting from its percolation through the ruptured shell, we adopt a simple model based on the thin-shell snowplow approximation and a relaxation-type equation for the mass transfer by mixing. Our calculations indicate that, despite the beneficial role of mixing, the increase in the nickel radial velocity at the stage of nickel bubble instability is relatively modest and, when combined with the published results for the preceding stage of instabilities in SN 1987A, not sufficient to explain the observed Ni/Co/Fe velocities of congruent-to 3000 km s-1. The observed velocities could however be explained if the preceding stage ended (at t congruent-to 10(4) s) by ejection of a few nickel clumps with masses M(n) congruent-to 0.1M(Ni) congruent-to 0.007 M. and radial velocities congruent-to 1800 km s-1. The values of the Ni/Co/Fe volume filling factor, f(n) = 0.3-0.9, that we calculate with our model agree very well with those inferred by Li, McCray, & Sunyaev (1993) from the emission-line data. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RI Basko, Mikhail/Q-7767-2016 OI Basko, Mikhail/0000-0001-8809-8601 NR 35 TC 28 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1994 VL 425 IS 1 BP 264 EP 273 DI 10.1086/173983 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NE028 UT WOS:A1994NE02800028 ER PT J AU BRUM, JL JOHNSON, RD HUDGENS, JW AF BRUM, JL JOHNSON, RD HUDGENS, JW TI ELECTRONIC-SPECTRUM OF THE ALPHA,ALPHA-DIFLUOROETHYL RADICAL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MULTIPHOTON IONIZATION SPECTROSCOPY; VIBRATIONAL FREQUENCIES; ABINITIO; ASSIGNMENTS; CATION; STATES; CF AB The first electronic spectrum of the alpha,alpha-difluoroethyl radical (CF2CH3) was observed between 335 and 475 nm by resonance-enhanced multiphoton ionization (REMPI) spectroscopy. The spectrum arises from two-photon resonances with a 3p Rydberg state. A third laser photon ionized the radicals. The electronic origin is tentatively assigned at nu(00) = 43 275 cm(-1), and the vibrational progression is assigned as the nu(9)'(CF2 wag) = 530 cm(-1). In support of these spectral assignments, we report ab initio calculations at the MP2/6-31G*, G1, and G2 theory levels which found the optimum structures, vibrational frequencies, and relative energies of CF2CH3, CF2CH3+, CHF2CH2, and CHF2CH2+. C1 NIST,DIV CHEM KINET & THERMODYNAM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. NR 21 TC 1 Z9 1 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 7 PY 1994 VL 98 IS 14 BP 3645 EP 3649 DI 10.1021/j100065a017 PG 5 WC Chemistry, Physical SC Chemistry GA NF765 UT WOS:A1994NF76500017 ER PT J AU LINDLE, DW LESMANNER, W STEINBECK, L VILLALOBOS, E LEVIN, JC SELLIN, IA AF LINDLE, DW LESMANNER, W STEINBECK, L VILLALOBOS, E LEVIN, JC SELLIN, IA TI AUGER-ELECTRON PHOTOION COINCIDENCE MEASUREMENTS OF ATOMS AND MOLECULES USING X-RAY SYNCHROTRON-RADIATION SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article ID HIGH-ENERGY-RESOLUTION; SHAKE-OFF; ABSORPTION; THRESHOLD; BEAMLINE; EMISSION; SPECTRA; ARGON; KR AB As the availability of intense beams of hard X-rays from synchrotron-radiation sources has increased, interest in the fundamental interactions of X-rays with deep core electrons in free atoms and molecules has undergone a resurgence. These powerful X-ray sources have led to more highly differential measurements, providing ever more detailed information about atomic and molecular structure and dynamics. One such improvement in measurement technique is the application of electron-ion coincidence spectroscopy, which only recently has been extended to studies of deep core levels. A collaborative research program focusing on the dynamics of photoionization and Auger decay following hard X-ray absorption by atoms and small molecules, as well as subsequent fragmentation in the molecular case, has been ongoing at the National Synchrotron Light Source for the past few years. This report summarizes the capabilities of the program by reviewing results on argon near the K edge, and discusses briefly newer measurements on xenon and a few sulfur- and chlorine-containing molecules. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37891 USA. UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. RP UNIV NEVADA, DEPT CHEM, LAS VEGAS, NV 89154 USA. NR 29 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 EI 1873-2526 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD APR 4 PY 1994 VL 67 IS 2 BP 373 EP 385 DI 10.1016/0368-2048(93)02061-P PG 13 WC Spectroscopy SC Spectroscopy GA NJ329 UT WOS:A1994NJ32900012 ER PT J AU CAHN, JW TAYLOR, JE AF CAHN, JW TAYLOR, JE TI OVERVIEW NO-113 - SURFACE MOTION BY SURFACE-DIFFUSION SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID CAHN-HILLIARD EQUATION; MEAN-CURVATURE; BOUNDARY; MODEL; EXISTENCE; GROWTH; ENERGY; FLOW AB Geometry growth laws for morphological change are developed and examined for the class of dynamic problems where surface diffusion is the only transport mechanism and hence volume is conserved, attachment kinetics is treated, and the only driving force for surface motion is the reduction in total surface free energy. The two limiting laws in the isotropic case are: motion by the Laplacian of mean curvature as originally derived by Mullins, and motion by the difference between mean curvature and the average of mean curvature. A general law linking these limiting laws is formulated, and derived both from a physical model and from gradient flows. Anisotropic laws are given. We survey possible mathematical techniques for studying interface motion under all these laws. Among these are possible applications of modified phase field methods. C1 RUTGERS STATE UNIV, DEPT MATH, NEW BRUNSWICK, NJ 08903 USA. RP NATL INST STAND & TECHNOL, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 87 TC 166 Z9 168 U1 0 U2 25 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 APR PY 1994 VL 42 IS 4 BP 1045 EP 1063 DI 10.1016/0956-7151(94)90123-6 PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NA125 UT WOS:A1994NA12500001 ER PT J AU FASSETT, JD BEARY, ES XIONG, XX MOORE, LJ AF FASSETT, JD BEARY, ES XIONG, XX MOORE, LJ TI COMPARATIVE STRATEGIES FOR CORRECTION OF INTERFERENCES IN ISOTOPE-DILUTION MASS-SPECTROMETRIC DETERMINATION OF VANADIUM SO ANALYTICAL CHEMISTRY LA English DT Article ID RESONANCE IONIZATION; THERMAL ATOMIZATION; COUNTING DETECTION AB Vanadium has been determined in SRM 1573a, Tomato Leaves, by isotope dilution mass spectrometry using thermal ionization (TIMS) and resonance ionization (RIMS). The capabilities of the two techniques to compensate for interferences from chromium and titanium are compared. For thermal ionization, corrections to the m/e 50 signal of 13-60% were made for interferences. The resulting V concentration had a relative standard deviation of 1.2%. Regression analysis of the data identified second-order corrections that resulted in a between sample precision of 0.46%. Resonance ionization had a demonstrated specificity of 2000:1 against Cr and Ti interferences. The resulting ratio measurements were less precise than the thermal ionization, but the vanadium ratio could be measured directly with no corrections necessary for interferences. The concentration (+/- 1 sigma measurement uncertainty) for V determined was 835.4 +/- 3.8 ppb by TIMS with second-order interference corrections, 824 +/- 10 ppb by TIMS as initially measured, and 828 +/- 15 ppb as measured by RIMS. C1 EASTERN ANALYT INC,COLLEGE PK,MD 20742. RP FASSETT, JD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 12 TC 4 Z9 4 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 1 PY 1994 VL 66 IS 7 BP 1027 EP 1031 DI 10.1021/ac00079a017 PG 5 WC Chemistry, Analytical SC Chemistry GA ND415 UT WOS:A1994ND41500019 ER PT J AU BENITEZ, EL DARK, ML HUSK, DE SCHNATTERLY, SE TARRIO, C AF BENITEZ, EL DARK, ML HUSK, DE SCHNATTERLY, SE TARRIO, C TI SOFT-X-RAY DAMAGE TO P-TERPHENYL COATINGS FOR DETECTORS SO APPLIED OPTICS LA English DT Article DE P-TERPHENYL; PHOSPHOR; PHOTOLUMINESCENCE; SOFT X-RAY; DETECTOR; EFFICIENCY; PHOTON DAMAGE ID SODIUM-SALICYLATE; QUANTUM EFFICIENCY; PHOTODIODES; ULTRAVIOLET; REGIME; RANGE AB The organic phosphor p-terphenyl is used as a wavelength-converter coating in some soft-x-ray detectors. We have measured the absolute photoluminescent efficiency of p-terphenyl as a function of incident photon energy from 36 to 191 eV. We have also measured changes in the efficiency caused by soft-x-ray fluence (total photons absorbed per unit area) at several photon energies in this range. We find that efficiency drops rapidly as a function of fluence, with the rate of decrease increasing with higher soft x-ray energies. C1 NATL INST STAND & TECHNOL, PHYS LAB, GAITHERSBURG, MD 20899 USA. RP BENITEZ, EL (reprint author), UNIV VIRGINIA, DEPT PHYS, CHARLOTTESVILLE, VA 22903 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 1994 VL 33 IS 10 BP 1854 EP 1856 PG 3 WC Optics SC Optics GA ND424 UT WOS:A1994ND42400011 PM 20885518 ER PT J AU THORARINSSON, R LANDOLT, ML ELLIOTT, DG PASCHO, RJ HARDY, RW AF THORARINSSON, R LANDOLT, ML ELLIOTT, DG PASCHO, RJ HARDY, RW TI EFFECT OF DIETARY VITAMIN-E AND SELENIUM ON GROWTH, SURVIVAL AND THE PREVALENCE OF RENIBACTERIUM-SALMONINARUM INFECTION IN CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) SO AQUACULTURE LA English DT Article ID RAINBOW-TROUT SALMO; BACTERIAL KIDNEY-DISEASE; OXIDIZED FISH OIL; ATLANTIC SALMON; IMMUNE-RESPONSE; GAIRDNERI RICHARDSON; TISSUE PEROXIDATION; ALPHA-TOCOPHEROL; FATTY-ACIDS; DEFICIENCY AB Groups of juvenile spring chinook salmon naturally infected with Renibacterium salmoninarum, the causative agent of bacterial kidney disease, were fed diets containing different levels of vitamin E and selenium for 214 days in fresh water and 110 days in seawater. The fish were fed vitamin E at concentrations of either 53 +/- 3 mg (designated e) or 299 +/- 9 mg (designated E) alpha-tocopheryl acetate equivalence/kg dry diet in combination with sodium selenite to give selenium concentrations of either 0.038 +/- 0.008 mg (designated s) or 2.49 +/- 0.15 mg (designated S)/kg dry diet. No mortality occurred in the group fed the S/E diet, whereas mortality was 3% in the groups fed the s/E and S/e diets, and 31% in the group fed the s/e diet. At the end of the experiment, weight gain and hematocrit values were significantly greater in those fish fed the E diets compared with those fed the e diets, whereas the hepato-somatic index was significantly higher in fish fed the e diets. Glutathione peroxidase activity in blood plasma was significantly higher in fish fed the S diets compared with those fed the s diets. No definite effect of dietary vitamin E and selenium on the prevalence and severity of natural R. salmoninarum infections was demonstrated. C1 UNIV WASHINGTON,SCH FISHERIES,WH-10,SEATTLE,WA 98195. US FISH & WILDLIFE SERV,NATL FISHERIES RES CTR,NAVAL STN,SEATTLE,WA 98115. NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. NR 43 TC 23 Z9 31 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD APR 1 PY 1994 VL 121 IS 4 BP 343 EP 358 DI 10.1016/0044-8486(94)90269-0 PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA NJ368 UT WOS:A1994NJ36800004 ER PT J AU SKINNER, SL BROWN, A AF SKINNER, SL BROWN, A TI THE ENIGMATIC T-TAURI RADIO-SOURCE SO ASTRONOMICAL JOURNAL LA English DT Article ID VLA OBSERVATIONS; MASS-LOSS; STARS; EMISSION; WINDS; COMPANION; OUTFLOWS; AURIGA; CLOUDS; SEARCH AB We have analyzed eight high angular resolution images of the prototype low mass pre-main-sequence star T Tauri obtained with the Very Large Array between 1987 and 1990. Our objectives were to confirm a recent report that the radio emission is both variable and circularly polarized, to determine whether this behavior originates in the optical star or in the infrared source lying 0.6'' to its south, and to identify possible emission mechanisms. No variability or circular polarization was detected in the weak (almost-equal-to 1 mJy) radio emission associated with the visible star, down to levels of almost-equal-to 10%. The observed flux can be accounted for by free-free emission from an ionized wind with a mass-loss rate M = 3.7 x 10(-8) M. yr-1, but a more accurate determination of the spectral index is needed to test the validity of spherical wind models. In sharp contrast, the 3.6 cm emission of the infrared source is variable (almost-equal-to 4-7 mJy) on time scales less-than-or-equal-to 3 days and circularly polarized at low levels of almost-equal-to 3%-5%. The polarization was left circular when detected during periods of low radio activity but changed to right circular during a radio outburst, similar to the reversals that have been seen in some RS CVn binary systems. The spectral index is negative during ''quiescence,'' and we argue that the emission is nonthermal gyrosynchrotron radiation. The detection of magnetic radio activity in this optically invisible infrared source sparks new interest in clarifying its evolutionary status. Sensitive 3.6 cm images reveal weak emission extending almost-equal-to 1'' west of the T Tau system that is probably associated with high-velocity shock-excited gas flowing toward HH-1555. We find no radio evidence for a putative third component north of the visible star. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 40 TC 37 Z9 37 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 1994 VL 107 IS 4 BP 1461 EP 1468 DI 10.1086/116959 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NC565 UT WOS:A1994NC56500026 ER PT J AU FOX, DC LINSKY, JL VEALE, A DEMPSEY, RC BROWN, A NEFF, JE PAGANO, I RODONO, M BROMAGE, GE KURSTER, M SCHMITT, JHMM AF FOX, DC LINSKY, JL VEALE, A DEMPSEY, RC BROWN, A NEFF, JE PAGANO, I RODONO, M BROMAGE, GE KURSTER, M SCHMITT, JHMM TI ROTATIONAL MODULATION AND FLARES ON RS-CANUM-VENATICORUM AND BY-DRACONIS STARS .18. COORDINATED VLA, ROSAT, AND IUE OBSERVATIONS OF RS-CVN BINARIES SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE STARS, BINARIES, CLOSE; STARS, CORONAE; STARS, FLARE; RADIO CONTINUUM, STARS; ULTRAVIOLET, STARS; X-RAYS, STARS ID RADIO-EMISSION; CONTINUUM EMISSION; STELLAR ACTIVITY; COOL STARS; HR 1099; SYSTEMS; POLARIZATION; COMPONENTS; RADIATION; CORONAE AB As part of a coordinated program of multi-wavelength observations of RS CVn close binary systems, we observed 15 systems with the VLA and 10 systems with IUE, simultaneously or nearly simultaneously with the ROSAT All Sky Survey observations of these stars. Of the 22 systems observed with ROSAT, three were observed both by IUE and the VLA. The principal aim of this program was to check the validity of the existing empirical correlations between the radio and soft X-ray emissions of their coronae, and between the chromospheric/transition region and coronal emissions. Previous studies of these correlations were usually based on nonsimultaneous observations and thus might be biased by source variability. Radio observations were made at 3.6, 6 and 20 cm. Of the 15 observed RS CVn systems, we detected 11 with greater-than-or-equal-to 4sigma confidence at one or more wavelengths. The IUE observations were made within the RIASS (ROSAT-IUE All Sky Survey) program. We present the results of the VLA observations, along with the corresponding subsets of the ROSAT PSPC X-ray and WFC XUV survey, and RIASS IUE observations. We obtained an extended VLA/IUE/ROSAT simultaneous coverage of one system, TY Pyx, covering more than one orbital period. These observations reveal that the quiescent radio flux of TY Pyx is relatively constant over time scales of up to 7 hours, but that it did change by a factor of 3 over 24 hours, probably due to a flare on 1990 Nov 12. The UV, XUV and X-ray fluxes do not show large day-to-day or phase-related variability. The observation of the decay phase of a radio flare on El Eri, with no accompanying X-ray or XUV flare, suggests that the lack of a strong correlation between X-ray and radio flares previously noted for dMe flare stars holds for RS CVn systems as well. We suggest that the radio flare may have been due to a coherent emission process such as electron cyclotron emission. The simultaneous measurements presented here provide a unique test of the general correlation between radio and soft X-ray luminosities, L(radio) approximately L(x)m (Drake et al. 1989) with a power-law slope close to unity, which was previously derived using data obtained years apart. Our derived slopes are consistent with and thus support the general correlations between coronal and chromospheric/transition region emissions previously derived from nonsimultaneous measurements of a much larger sample of these variable sources. However, the importance of simultaneous measurements for accurate energy balance calculations is stressed. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. PENN STATE UNIV, DEPT ASTRON & ASTROPHYS, UNIV PK, PA 16802 USA. OSSERV ASTROFIS CATANIA, I-95125 CATANIA, ITALY. UNIV CATANIA, IST ASTRON, I-95125 CATANIA, ITALY. MAX PLANCK INST EXTRATERR PHYS, D-85740 GARCHING, GERMANY. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RI Pagano, Isabella/I-6934-2015 OI Pagano, Isabella/0000-0001-9573-4928 NR 54 TC 26 Z9 27 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 APR PY 1994 VL 284 IS 1 BP 91 EP 104 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ND829 UT WOS:A1994ND82900018 ER PT J AU DRECHSEL, H HAAS, S LORENZ, R MAYER, P AF DRECHSEL, H HAAS, S LORENZ, R MAYER, P TI NEW PHOTOMETRIC AND SPECTROSCOPIC RESULTS FOR IU-AURIGAE - AN EARLY-TYPE ECLIPSING BINARY IN A MULTIPLE SYSTEM SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE BINARIES, ECLIPSING; STARS, EARLY-TYPE; STARS, FUNDAMENTAL PARAMETERS; STARS, IU-AUR ID TRIPLE SYSTEM; LIGHT CURVES; PARAMETERS AB Improved light curve solutions and new spectroscopic results for the eclipsing multiple system IU Aur are presented. The early-type binary serves as a test case for the application of a newly developed light curve solution code taking into account the radiation pressure effects caused by the mutual irradiation of the binary components. Improved orbital elements and absolute dimensions are derived. The system is of special interest due to a gravitationally bound third component in a noncoplanar orbit causing a precessional motion of the orbital plane of the close binary. The long-term inclination change with time was investigated by an analysis of the variation of eclipse minimum depths. The nodal rotation period of 335 years and the inclination of the third body orbit are consistent with the theoretically expected values, if a third body mass of 17-18 M. is assumed, which fully complies with the restraints required by the light time orbit. High resolution Coude/CCD spectra were used for an improved determination of the binary mass ratio, which agrees well with the revised photometric solutions. The spectra also allowed for a first spectroscopic detection of the third component. The photometric third light contribution of about 20% and the line strengths of the third body are inconsistent with its mass if ascribed to a single early B-type star. It is therefore suggested that IU Aur is actually not a triple, but a double binary system. C1 NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV ERLANGEN NURNBERG, INST ASTRON, D-96049 BAMBERG, GERMANY. CHARLES UNIV, INST ASTRON, CR-15000 PRAGUE 5, CZECH REPUBLIC. RP DRECHSEL, H (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. RI Drechsel, Horst/D-9696-2013 NR 23 TC 27 Z9 27 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR PY 1994 VL 284 IS 3 BP 853 EP 864 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NJ385 UT WOS:A1994NJ38500014 ER PT J AU PARSONS, D DABBERDT, W COLE, H HOCK, T MARTIN, C BARRETT, AL MILLER, E SPOWART, M HOWARD, M ECKLUND, W CARTER, D GAGE, K WILSON, J AF PARSONS, D DABBERDT, W COLE, H HOCK, T MARTIN, C BARRETT, AL MILLER, E SPOWART, M HOWARD, M ECKLUND, W CARTER, D GAGE, K WILSON, J TI THE INTEGRATED SOUNDING SYSTEM - DESCRIPTION AND PRELIMINARY-OBSERVATIONS FROM TOGA-COARE SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID WIND PROFILER; PACIFIC-OCEAN; CONVECTION AB An Integrated Sounding System (ISS) that combines state-of the-art remote and in situ sensors into a single transportable facility has been developed jointly by the National Center for Atmospheric Research (NCAR) and the Aeronomy Laboratory of the National Oceanic and Atmospheric Administration (NOAA/AL). The instrumentation for each ISS includes a 915-MHz wind profiler, a Radio Acoustic Sounding System (RASS), an Omega-based NAVAID sounding system, and an enhanced surface meteorological station. The general philosophy behind the ISS is that the integration of various measurement systems overcomes each system's respective limitations while taking advantage of its positive attributes. The individual observing systems within the ISS provide high-level data products to a central workstation that manages and integrates these measurements. The ISS software package performs a wide range of functions: real-time data acquisition, database support, and graphical displays; data archival and communications; and operational and posttime analysis. The first deployment of the ISS consists of six sites in the western tropical Pacific-four land-based deployments and two ship-based deployments. The sites serve the Coupled Ocean-Atmosphere Response Experiment (COARE) of the Tropical Ocean and Global Atmosphere (TOGA) program and TOGA's enhanced atmospheric monitoring effort. Examples of ISS data taken during this deployment are shown in order to demonstrate the capabilities of this new sounding system and to demonstrate the performance of these in situ and remote sensing instruments in a moist tropical environment. In particular, a strong convective outflow with a pronounced impact of the atmospheric boundary layer and heat fluxes from the ocean surface was examined with a shipboard ISS. If these strong outflows commonly occur, they may prove to be an important component of the surface energy budget of the western tropical Pacific. C1 NOAA,AERON LAB,BOULDER,CO 80303. RP PARSONS, D (reprint author), NATL CTR ATMOSPHER RES,DIV ATMOSPHER TECHNOL,POB 3000,BOULDER,CO 80307, USA. NR 30 TC 125 Z9 125 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 APR PY 1994 VL 75 IS 4 BP 553 EP 567 DI 10.1175/1520-0477(1994)075<0553:TISSDA>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG920 UT WOS:A1994NG92000002 ER PT J AU JI, M KUMAR, A LEETMAA, A AF JI, M KUMAR, A LEETMAA, A TI A MULTISEASON CLIMATE FORECAST SYSTEM AT THE NATIONAL-METEOROLOGICAL-CENTER SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID NINO SOUTHERN OSCILLATION; TROPICAL PACIFIC-OCEAN; EL-NINO; EQUATORIAL PACIFIC; SEASONAL CYCLE; MODEL; CIRCULATION; VARIABILITY; SIMULATION; ATMOSPHERE AB The Coupled Model Project was established at the National Meteorological Center (NMC) in January 1991 to develop a multiseason forecast system based on coupled ocean-atmosphere general circulation models. This provided a focus to combine expertise in near real-time ocean modeling and analyses situated in the Climate Analysis Center (CAC) with expertise in atmospheric modeling and data assimilation in the Development Division. Since the inception of the project, considerable progress has been made toward establishing a coupled forecast system. A T40 version of NMC's operational global medium-range forecast model (MRF) has been modified so as to have improved response to boundary forcing from the Tropics. In extended simulations, which are forced with observed historical global sea surface temperature (SST) fields, the model reproduces much of the observed tropical Pacific and North American rainfall and temperature variability. An ocean reanalysis has been performed for the Pacific basin starting from July 1982 to present and uses a dynamical model-based assimilation system. This also provides the ocean initial conditions for coupled forecast experiments. The current coupled forecast model consists of an active Pacific Ocean model coupled to the T40 version of the NMC's MRF. In the future, a global ocean model will be used to include climate information from the other ocean basins. The initial experiments focused on forecasting Northern Hemisphere winter SST anomalies in the tropical Pacific with a lead time of two seasons. The coupled model showed considerable skill during these experiments. Work is currently under way to quantify the skill in predicting climatic variability over North America. RP JI, M (reprint author), NOAA,NWS,NATL METEOROL CTR,COUPLED MODEL PROJECT,5200 AUTH RD,ROOM 807,CAMP SPRINGS,MD 20746, USA. NR 41 TC 81 Z9 90 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 APR PY 1994 VL 75 IS 4 BP 569 EP 577 DI 10.1175/1520-0477(1994)075<0569:AMCFSA>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG920 UT WOS:A1994NG92000003 ER PT J AU OHRING, G AOKI, T HALPERN, D HENDERSON-SELLERS, A CHARLOCK, T JOSEPH, J LABITZKE, K RASCHKE, E SMITH, W AF OHRING, G AOKI, T HALPERN, D HENDERSON-SELLERS, A CHARLOCK, T JOSEPH, J LABITZKE, K RASCHKE, E SMITH, W TI JOINT IAMAS-IAHS SYMPOSIUM-J1 ON GLOBAL MONITORING AND ADVANCED OBSERVING TECHNIQUES IN THE ATMOSPHERE AND HYDROSPHERE SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB Seventy papers were presented at the two-and-a-half-day Symposium on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere. The symposium was jointly organized by the International Association of Meteorology and Atmospheric Sciences (IAMAS) and the International Association of Hydrological Sciences (IAHS) and took place in Yokohama, Japan, 13-15 July 1993, as part of the IAMAS/IAHS Joint Assembly. Global observing systems are receiving increased attention in connection with such problems as monitoring global climate change. The symposium included papers on observational requirements; measurement methodologies; descriptions of available datasets; results of analysis of observational data; plans for future observing systems, including the Global Climate Observing System (GCOS) and the Global Ocean Observing System (GOOS); and the programs and plans of the space agencies. C1 METEOROL RES INST, RES LAB 4, TOKYO 166, JAPAN. MACQUARIE UNIV, CTR CLIMAT IMPACTS, N RYDE, NSW 2113, AUSTRALIA. UNIV WISCONSIN, COOPERAT INST METEOROL SATELLITE STUDIES, MADISON, WI 53706 USA. FREE UNIV BERLIN, INST METEOROL, W-1000 BERLIN 33, GERMANY. TEL AVIV UNIV, DEPT GEOPHYS & PLANETARY SCI, IL-69978 TEL AVIV, ISRAEL. JET PROP LAB, PASADENA, CA 91109 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. GKSS FORSCHUNGSZENTRUM GEESTHACHT GMBH, INST PHYS, GEESTHACT TESPERHADE, GERMANY. RP OHRING, G (reprint author), NOAA, NESDIS, SATELLITE RES LAB, WASHINGTON, DC 20233 USA. RI Ohring, George/F-5616-2010; Henderson-Sellers, Ann/H-5323-2011 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1994 VL 75 IS 4 BP 595 EP 599 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG920 UT WOS:A1994NG92000006 ER PT J AU WILLOUGHBY, HE AF WILLOUGHBY, HE TI THE 20TH CONFERENCE ON HURRICANES AND TROPICAL METEOROLOGY SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material RP WILLOUGHBY, HE (reprint author), NOAA,AOML,DIV HURRICANE RES,4301 RICKERBACKER CAUSEWAY,MIAMI,FL 33149, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1994 VL 75 IS 4 BP 601 EP 611 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG920 UT WOS:A1994NG92000007 ER PT J AU RICE, SD THOMAS, RE MOLES, A AF RICE, SD THOMAS, RE MOLES, A TI PHYSIOLOGICAL AND GROWTH DIFFERENCES IN 3 STOCKS OF UNDERYEARLING SOCKEYE-SALMON (ONCORHYNCHUS-NERKA) ON EARLY ENTRY INTO SEAWATER SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article AB We compared the impact of exposure to seawater on three sockeye salmon (Oncorhynchus nerka) stocks: one that normally migrates to sea as underyearlings (sea-type) and two with the more common life history strategies of 1 (river-type) or 2 (lake-type) yr of freshwater residence prior to seaward migration. Innate differences in survival, ability to regulate tissue chlorides, and oxygen consumption when first introduced into salt water were more evident in April and May when fish were less than 50 mm in length. In fish longer than 50 mm, the only significant differences among the stocks were in saltwater growth. Between June and August, sea-type fish showed faster growth than river-type fish which in turn grew faster than lake-type fish. When introduced into salt water in October, virtually no growth occurred in any stock, regardless of fish size. River-type and lake-type sockeye, which normally overwinter 1 and 2 yr, respectively, in freshwater, can be reared in seawater if underyearlings are raised to a length of 50 mm before release into salt water, similar to the normal life history of sea-type underyearlings. Early life history appears to be influenced more by habitat than by genetics. C1 CALIF STATE UNIV CHICO,DEPT BIOL SCI,CHICO,CA 95929. NOAA,NATL MARINE FISHERIES SERV,AUKE BAY LAB,JUNEAU,AK 99801. NR 26 TC 8 Z9 9 U1 1 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 APR PY 1994 VL 51 IS 4 BP 974 EP 980 DI 10.1139/f94-097 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA NR098 UT WOS:A1994NR09800023 ER PT J AU LAMAZE, GP DOWNING, RG HACKENBERGER, LB PILIONE, LJ MESSIER, R AF LAMAZE, GP DOWNING, RG HACKENBERGER, LB PILIONE, LJ MESSIER, R TI ANALYSIS OF CUBIC BORON-NITRIDE THIN-FILMS BY NEUTRON DEPTH PROFILING SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 4th European Conference on Diamond, Diamond-like and Related Materials (Diamond Films 93) CY SEP 20-24, 1993 CL ALBUFEIRA, PORTUGAL SP AEA TECHNOL, SURF TECHNOL, HARWELL LAB, ASTEX, COMMISS EUROPEAN COMMUNITIES, DG TEER COATING SERV LTD, DIAMOND & RELATED MAT, DRUKKER INT BV, GENASYSTEMS INC, KOBE STEEL USA INC, ELECTR MAT CTR, NORTON DIAMOND FILM, RENISHHAW TRANSDUCER SYST LTD, US DEPT DEF AB Cubic boron nitride (c-BN) thin films are of interest in such diverse areas as semiconducting devices, wear resistant coatings, and low friction coatings, owing to the exceptional electrical and mechanical properties of that material. In this work, the boron to nitrogen ratio of thin films produced by physical vapor deposition (PVD) was determined and compared with the crystal phase of BN thin films. Thin films (approximately 0.1 mum) of c-BN were deposited onto heated silicon substrates by electron beam evaporation of boron with concurrent nitrogen and argon ion bombardment. The films were characterized by IR spectroscopy. The stoichiometry of the BN layer was determined by neutron depth profiling (NDP) using the nuclear reactions B-10(n,alpha) Li-7 and N-14(n,p) C-14. Boron-to-nitrogen ratios were determined with uncertainties of 2%-3%. Shifts in IR spectra were observed over a narrow range of boron-to-nitrogen ratios near unity. Stoichiometric results are compared with the crystal phase. Details of the NDP analysis are presented. C1 PENN STATE UNIV,INTERCOLL MAT RES LAB,UNIV PK,PA 16802. RP LAMAZE, GP (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL,BLDG 235,GAITHERSBURG,MD 20899, USA. NR 6 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 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR PY 1994 VL 3 IS 4-6 BP 728 EP 731 DI 10.1016/0925-9635(94)90258-5 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA NN160 UT WOS:A1994NN16000085 ER PT J AU JIN, S FANCIULLI, M MOUSTAKAS, TD ROBINS, LH AF JIN, S FANCIULLI, M MOUSTAKAS, TD ROBINS, LH TI ELECTRONIC CHARACTERIZATION OF DIAMOND FILMS PREPARED BY ELECTRON-CYCLOTRON-RESONANCE MICROWAVE PLASMA SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 4th European Conference on Diamond, Diamond-like and Related Materials (Diamond Films 93) CY SEP 20-24, 1993 CL ALBUFEIRA, PORTUGAL SP AEA TECHNOL, SURF TECHNOL, HARWELL LAB, ASTEX, COMMISS EUROPEAN COMMUNITIES, DG TEER COATING SERV LTD, DIAMOND & RELATED MAT, DRUKKER INT BV, GENASYSTEMS INC, KOBE STEEL USA INC, ELECTR MAT CTR, NORTON DIAMOND FILM, RENISHHAW TRANSDUCER SYST LTD, US DEPT DEF ID CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; CATHODOLUMINESCENCE; DEFECTS; GROWTH; TEMPERATURES; CONDUCTIVITY; CVD AB Diamond films with different surface morphologies were produced by the electron cyclotron resonance microwave-plasma-assisted CVD method from gas mixtures containing CO-H-2-O2 at a relatively low pressure. The electrical conductivity of the samples along the growth direction was measured in the temperature range from 200 to 800-degrees-C. The films with (111) morphologies have conductivity activation energies of between 0.3 and 0.4 eV consistent with boron incorporation in such films. On the contrary, films with (100) morphologies have a conductivity activation energy of 1.5 eV consistent with nitrogen incorporation in such films. Electron spin resonance and cathodoluminescence measurements show the simultaneous existence of boron and nitrogen impurities. Owing to their high solubility, boron and nitrogen are the most common impurities in natural and synthetic diamonds. The results suggest that electrically active boron and nitrogen incorporation takes place more efficiently when growth proceeds along the (111) and (100) directions respectively. C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP JIN, S (reprint author), BOSTON UNIV,DEPT ELECT ENGN,BOSTON,MA 02215, USA. RI Fanciulli, Marco/J-9940-2013; Moustakas, Theodore/D-9249-2016 OI Fanciulli, Marco/0000-0003-2951-0859; Moustakas, Theodore/0000-0001-8556-884X NR 19 TC 10 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR PY 1994 VL 3 IS 4-6 BP 878 EP 882 DI 10.1016/0925-9635(94)90291-7 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA NN160 UT WOS:A1994NN16000118 ER PT J AU BLOOD, DM MATARESE, AC YOKLAVICH, MM AF BLOOD, DM MATARESE, AC YOKLAVICH, MM TI EMBRYONIC-DEVELOPMENT OF WALLEYE POLLOCK, THERAGRA-CHALCOGRAMMA, FROM SHELIKOF STRAIT, GULF-OF-ALASKA SO FISHERY BULLETIN LA English DT Article ID EARLY LIFE-HISTORY; TEMPERATURE AB Eggs of walleye pollock, Theragra chalcogramma, from Shelikof Strait, Alaska, were reared at three temperatures: 3.8-degrees, 5.7-degrees, and 7.7-degrees-C. Development was divided into 21 stages. A piecewise regression model with midpoints of each stage describes the relation between time to each stage of development and temperature. Preserved eggs of each stage are described, illustrated, and photographed. Midpoint of hatch was 393 hours at 3.8-degrees-C, 303 hours at 5.7-degrees-C, and 234 hours at 7.7-degrees-C. Mean length of larvae at hatch increased linearly with temperature. We compared rate of development, time to 50% hatch, and morphological development with other studies of walleye pollock eggs. Rate of development and time to 50% hatch were similar among populations of eastern North Pacific walleye pollock. Western North Pacific walleye pollock required longer incubation times than eastern North Pacific walleye pollock. Morphological development of Shelikof Strait eggs differs from development of western North Pacific walleye pollock eggs: optic vesicles, myomeres, eye lenses, heart, and otic capsules appear earlier than in Shelikof Strait eggs, and eye pigment appears later. The differences in development may be exacerbated by the condition of the eggs in which they were examined (e.g. preserved vs. live). Developmental differences between stocks are discussed with the conclusion that model components for egg mortality and spawning biomass must be based on specimens collected in the area of interest. RP BLOOD, DM (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 25 TC 28 Z9 29 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 207 EP 222 PG 16 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700003 ER PT J AU BRODEUR, RD RUGEN, WC AF BRODEUR, RD RUGEN, WC TI DIEL VERTICAL-DISTRIBUTION OF ICHTHYOPLANKTON IN THE NORTHERN GULF OF ALASKA SO FISHERY BULLETIN LA English DT Article ID POLLOCK THERAGRA-CHALCOGRAMMA; LARVAL WALLEYE POLLOCK; PLANKTONIC COPEPOD; SHELIKOF STRAIT; MIGRATION; ZOOPLANKTON; FISHES; CALIFORNIA; PREDATORS; PREY AB The diel vertical distribution patterns of several abundant ichthyoplankton taxa were examined from depth-stratified tows off Kodiak Island in the western Gulf of Alaska during 1986 and 1987. Most larvae were found in the upper 45 m of the water column throughout the diel period but were concentrated in higher densities near the surface (0-15 m) in daylight hours and at greater depths at night. Four of the five dominant taxa examined in detail showed significantly greater weighted mean depths during the night than during the day. This pattern was the opposite to that previously reported for the numerically dominant taxa (Theragra chalcogramma) in this area. Since there was no clear relation between the diel vertical distribution of these taxa and the vertical distribution of water temperature and density or copepod nauplii prey, we hypothesize that this reverse migration is either a strategy to minimize spatial overlap with predators that follow a normal diel migration pattern or one to optimize light levels for feeding. RP BRODEUR, RD (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 34 TC 31 Z9 32 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 223 EP 235 PG 13 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700004 ER PT J AU DITTY, JG SHAW, RF GRIMES, CB COPE, JS AF DITTY, JG SHAW, RF GRIMES, CB COPE, JS TI LARVAL DEVELOPMENT, DISTRIBUTION, AND ABUNDANCE OF COMMON DOLPHIN, CORYPHAENA-HIPPURUS, AND POMPANO DOLPHIN, C-EQUISELIS (FAMILY, CORYPHAENIDAE), IN THE NORTHERN GULF-OF-MEXICO SO FISHERY BULLETIN LA English DT Article ID SPATIAL-DISTRIBUTION; WATERS; FISHES; PLUME AB Dolphinfishes are highly prized commercial and recreational species of worldwide distribution in tropical and subtropical seas, but the development and distribution of their larvae are poorly understood. Common dolphin eggs hatch in about 38 hours at 25-degrees-C based on a predictive relationship among egg diameter, water temperature, and development time. Morphometrics are generally greater in pompano dolphin than in common dolphin. Pompano dolphin are deeper-bodied and have a larger eye by 9 mm, and a larger mouth and longer pre-anal length by about 13 mm. Differences in pigment along the caudal peduncle and its finfold separate common dolphin from pompano dolphin <4.0-4.5 mm SL; common dolphin lack pigment in these areas. Number of spines along the outer shelf of the preopercle also separate species although preopercle spines are often difficult to count on larvae not cleared and stained; common dolphin have four spines along the outer preopercular shelf and pompano dolphin have five. Pigmented pelvic fins and bands of pigment laterally on both the body and median fins of common dolphin are diagnostic for separating species >8 mm SL; pompano dolphin lack these characters. Both common dolphin and pompano dolphin larvae usually are found at greater-than-or-equal-to 24-degrees-C, greater-than-or-equal-to 33 ppt, and beyond the 50 m isobath. Preflexion larvae (<7.0-7.5 mm SL) were primarily collected in oceanic waters. Both species may spawn year-round, at least in the southern part of the survey area. Larval common dolphin are significantly more abundant than pompano dolphin. C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,PANAMA CITY LAB,PANAMA CITY,FL 32408. RP DITTY, JG (reprint author), LOUISIANA STATE UNIV,CTR COASTAL ENERGY & ENVIRONM RESOURCES,INST COASTAL FISHERIES,BATON ROUGE,LA 70803, USA. NR 41 TC 32 Z9 32 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 275 EP 291 PG 17 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700008 ER PT J AU KASTELLE, CR KIMURA, DK NEVISSI, AE GUNDERSON, DR AF KASTELLE, CR KIMURA, DK NEVISSI, AE GUNDERSON, DR TI USING PB-210/RA-226 DISEQUILIBRIA FOR SABLEFISH, ANOPLOPOMA-FIMBRIA, AGE VALIDATION SO FISHERY BULLETIN LA English DT Article ID PB-210-RA-226; OTOLITHS; GROWTH; LONGEVITY; FECUNDITY; PISCES; PO-210; PB-210 AB Age determination of sablefish (Anoplopoma fimbria) is typically done by counting growth zones on the burnt cross-section of the otolith. The break-and-burn method of age determination is difficult to apply to sablefish. Therefore, we applied a relatively new method of fish age validation, using the disequilibrium of Pb-210/Ra-226 in the otoliths. This method of validation complements previous methods which used oxytetracycline (OTC) marking to validate incremental growth in sablefish otoliths. The Pb-210/Ra-226 disequilibria generally confirmed the ageing criteria used to interpret the otolith's burnt cross-section. C1 UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98195. RP KASTELLE, CR (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 36 TC 29 Z9 29 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 292 EP 301 PG 10 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700009 ER PT J AU PERRIN, WF SCHNELL, GD HOUGH, DJ GILPATRICK, JW KASHIWADA, JV AF PERRIN, WF SCHNELL, GD HOUGH, DJ GILPATRICK, JW KASHIWADA, JV TI REEXAMINATION OF GEOGRAPHIC-VARIATION IN CRANIAL MORPHOLOGY OF THE PANTROPICAL SPOTTED DOLPHIN, STENELLA-ATTENUATA, IN THE EASTERN PACIFIC SO FISHERY BULLETIN LA English DT Article ID TROPICAL PACIFIC; SEXUAL DIMORPHISM; OCEAN; LONGIROSTRIS AB The spotted dolphin (Stenella attenuata) is found throughout much of the eastern tropical Pacific Ocean. A previous study evaluated morphological variation in skull morphology, but now specimens are available for a greater portion of the range. Also, corrections have been made in data and an assessment has been made evaluating repeatability of character measurements. We reassessed geographic variation in 30 cranial features (26 morphometric measures and 4 tooth counts) based on 611 museum specimens. All characters except two tooth counts showed statistically significant geographic variation, while 21 of the 30 characters exhibited significant sexual dimorphism. Males were larger in most characters; females were larger in some length measurements involving the rostrum and ramus. As in previous analyses, inshore S. attenuata were found to be very distinctive, so subsequent analyses focused on offshore spotted dolphins from 29 5-degrees latitude-longitude blocks. Mantel tests and matrix correlations for 19 of the 30 features demonstrated significant ''regional patterning,'' whereas 22 of the characters were shown to have ''local patterning.'' Principal-components, canonical-variates, and cluster (UPGMA and function-point) analyses also were employed to assess geographic variation. In the eastern portion of the range, the subdivision between northern and southern offshore S. attenuata found in the previous investigation was confirmed. In general, blocks to the west (including one encompassing part of the Hawaiian Islands) were more like the southern blocks than those of the northeast. Morphological patterns were similar to those found in a number of environmental variables, particularly water depth, solar insolation (January), sea surface temperature (January and July), surface salinity, and thermocline depth (winter and summer). Present management units are inconsistent with the pattern of cranial variation; spotted dolphins from west of lat. 120-degrees-W probably should not be pooled with those to the east, as they show closer affinity with the Southern Offshore unit. In addition, the boundary between the Northern and Southern units should probably be moved north to about lat. 5-degrees-N. C1 UNIV OKLAHOMA,OKLAHOMA BIOL SURVEY,NORMAN,OK 73019. UNIV OKLAHOMA,DEPT ZOOL,NORMAN,OK 73019. RP PERRIN, WF (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 29 TC 9 Z9 9 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 324 EP 346 PG 23 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700012 ER PT J AU PRAGER, MH AF PRAGER, MH TI A SUITE OF EXTENSIONS TO A NONEQUILIBRIUM SURPLUS-PRODUCTION MODEL SO FISHERY BULLETIN LA English DT Article ID BOOTSTRAP CONFIDENCE-INTERVALS; CATCH-EFFORT DATA; POPULATIONS; APPROPRIATE; JACKKNIFE; ABUNDANCE; YIELD; AREA AB Surplus-production models, because of their simplicity and relatively undemanding data needs, are attractive tools for many stock assessments. This paper reviews the logistic production model, starting with the basic differential equation and continuing with a description of the model development without the equilibrium assumption. It then describes several extensions, including ''tuning'' the model to a biomass index; partitioning fishing mortality by gear, time, or area; and making projections. Computation of confidence intervals on quantities of interest (e.g. maximum sustainable yield (MSY), effort at MSY, level of stock biomass relative to the optimum level) can be done through boot-strapping, and the bootstrap can also be used to construct nonparametric tests of hypotheses about changes in catchability. To fit the model, an algorithm that uses a forward solution of the population equations can be implemented on a small computer. An example of the utility of surplus-production models (illustrating several of these extensions) is given. The example is loosely based on swordfish (Xiphias gladius) in the North Atlantic Ocean, but is not intended to describe the actual status of that stock. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,COOPERAT UNIT FISHERIES EDUC & RES,MIAMI,FL 33149. RP PRAGER, MH (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI LAB,MIAMI,FL 33149, USA. NR 71 TC 120 Z9 135 U1 1 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 374 EP 389 PG 16 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700014 ER PT J AU WARLEN, SM AF WARLEN, SM TI SPAWNING TIME AND RECRUITMENT DYNAMICS OF LARVAL ATLANTIC MENHADEN, BREVOORTIA-TYRANNUS, INTO A NORTH-CAROLINA ESTUARY SO FISHERY BULLETIN LA English DT Article ID FISH AB Larval Atlantic menhaden, Brevoortia tyrannus, were collected weekly during their expected recruitment (November-April) to the estuary near Beaufort, North Carolina, over seven consecutive years beginning 1985-86. The larval density in nighttime quantitative samples was calculated and ages determined from otolith microstructure. Back-calculated birthdates and larval abundance data were used to estimate the relative contribution of weekly age cohorts to seasonal recruitment of larvae. Summaries of these data were measures of the spawning distributions. Larvae were recruited to the estuary from mid-November through April, with about 86% collected during February-April. In all years, age and size of larvae increased linearly throughout recruitment until the end of March and then declined. The mean age of recruited larvae over all years was 61 days and the mean standard length was 24.6 mm. Atlantic menhaden spawning season was protracted, lasting 4-6 months. In every spawning season, a dominant birthweek mode in either December or January contributed from 25-43% of the total recruits. More than 76% of all spawning occurred in the December-January period. Individual birthweek cohorts recruited to the estuary over periods from one week to several months. Cohorts that usually contributed the greatest number of individuals to estuarine recruitment usually recruited over longer periods. Atlantic menhaden have apparently selected a spawning season and location that ensures transport of larvae across the southeast United States continental shelf and arrival of most larvae during a time when conditions are conducive to optimal survival in the estuary. RP WARLEN, SM (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,101 PIVERS ISL RD,BEAUFORT,NC 28516, USA. NR 33 TC 49 Z9 50 U1 0 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 420 EP 433 PG 14 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700017 ER PT J AU REILLY, SB FIEDLER, PC AF REILLY, SB FIEDLER, PC TI INTERANNUAL VARIABILITY OF DOLPHIN HABITATS IN THE EASTERN TROPICAL PACIFIC .1. RESEARCH VESSEL SURVEYS, 1986-1990 SO FISHERY BULLETIN LA English DT Article ID ABUNDANCE; STENELLA; OCEAN; POPULATIONS AB We used canonical correspondence analysis (CCA), an eigenvector ordination technique that includes direct gradient analysis, to investigate habitat use by spotted, Stenella attenuata, spinner, S.longirostris, striped, S. coeruleoalba, and common, Delphinis delphis, dolphins in the eastern tropical Pacific during 1986-90. Data were collected during annual research vessel cruises conducted in August-November of each year. Environmental variables included in the analyses were surface temperature, salinity, sigma-t, and chlorophyll, and thermocline depth and thickness. The dominant pattern in the species-environment relationship (1st canonical axis) separated common dolphins from spotted and spinner dolphins, based on their associations with cool upwelling habitat and warm tropical habitat, respectively. The second axis separated whitebelly spinners from eastern spinner dolphins. Both occurred in tropical water, but were separated primarily by thermocline topography. The species-environment correlations were 0.67 on the first axis, 0.42 on the second. Overall, the environmental data explained 15% of the variance in the species data. For individual school types this ranged from 36% for common dolphins to 6% for striped dolphins. Interannual variability in the species data was small but was judged significant by a Monte Carlo randomization test. Residual interannual variance was insignificant after removing variance associated with environmental variables. RP REILLY, SB (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 48 TC 59 Z9 65 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 APR PY 1994 VL 92 IS 2 BP 434 EP 450 PG 17 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700018 ER PT J AU FIEDLER, PC REILLY, SB AF FIEDLER, PC REILLY, SB TI INTERANNUAL VARIABILITY OF DOLPHIN HABITATS IN THE EASTERN TROPICAL PACIFIC .2. EFFECTS ON ABUNDANCES ESTIMATED FROM TUNA VESSEL SIGHTINGS, 1975-1990 SO FISHERY BULLETIN LA English DT Article ID STENELLA-LONGIROSTRIS; OCEAN; SIZE AB The results of a canonical correspondence analysis (CCA) of data from research vessel surveys of the eastern tropical Pacific were applied to time series of estimated dolphin abundances from tuna vessel sightings. The research vessel survey data consisted of daily dolphin school sightings and concurrent environmental variables for August-November of 1986 through 1990. Seasonal fields of habitat quality for 1975-90 were calculated from historical bathythermograph data by using the CCA ordination results. For spotted (Stenella attenuata) and eastern spinner (S. longirostris orientalis) dolphins, annual abundance estimates or interannual changes in those estimates are significantly correlated with habitat quality. This effect is at least partly due to expansion of high quality habitat beyond the geographic ranges assumed for the abundance estimate. We discuss ways that environmental data could be used to reduce error in dolphin abundance estimates. RP FIEDLER, PC (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 20 TC 26 Z9 27 U1 0 U2 2 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1994 VL 92 IS 2 BP 451 EP 463 PG 13 WC Fisheries SC Fisheries GA NH457 UT WOS:A1994NH45700019 ER PT J AU SELVERSTONE, J GUTZLER, DS AF SELVERSTONE, J GUTZLER, DS TI POST-125 MA CARBON STORAGE ASSOCIATED WITH CONTINENT-CONTINENT COLLISION - REPLY SO GEOLOGY LA English DT Note ID FLUID; METAMORPHISM; SUBDUCTION; TRANSPORT C1 NOAA,AERONOMY LAB,BOULDER,CO 80303. RP SELVERSTONE, J (reprint author), UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309, USA. RI Selverstone, Jane/A-9809-2008 OI Selverstone, Jane/0000-0003-4234-4111 NR 11 TC 1 Z9 1 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD APR PY 1994 VL 22 IS 4 BP 382 EP 383 PG 2 WC Geology SC Geology GA NE800 UT WOS:A1994NE80000026 ER PT J AU BURKHOLDER, JB TALUKDAR, RK AF BURKHOLDER, JB TALUKDAR, RK TI TEMPERATURE-DEPENDENCE OF THE OZONE ABSORPTION-SPECTRUM OVER THE WAVELENGTH RANGE 410 TO 760 NM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MCMURDO STATION; CROSS-SECTIONS; SPECTROSCOPY; ANTARCTICA; NO2; O-3 AB The ozone, O3, absorption cross sections between 410 and 760 nm, the Chappuis band, were measured at 220, 240, 260, and 280 K relative to that at room temperature using a diode array spectrometer. The measured cross sections varied very slightly, < 1%, with decreasing temperature between 550 and 660 nm, near the peak of the Chappuis band. At wavelengths away from the peak, the absorption cross sections decreased with decreasing temperature; e.g., approximately 40% at 420 nm between 298 and 220 K. These results are compared with previous measurements and the impact on atmospheric measurements are discussed. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP BURKHOLDER, JB (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80309, USA. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 14 TC 78 Z9 82 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1994 VL 21 IS 7 BP 581 EP 584 DI 10.1029/93GL02311 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NE512 UT WOS:A1994NE51200019 ER PT J AU BURKHOLDER, JB TALUKDAR, RK RAVISHANKARA, AR AF BURKHOLDER, JB TALUKDAR, RK RAVISHANKARA, AR TI TEMPERATURE-DEPENDENCE OF THE CLONO2 UV ABSORPTION-SPECTRUM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CROSS-SECTIONS AB The temperature dependence of the ClONO2 absorption spectrum has been measured between 220 and 298 K and between 195 and 430 nm using a diode array spectrometer. The absorption cross sections were determined using both: (1) absolute pressure measurements at 296 K and (2) measurements at various temperatures relative to 296 K using a dual absorption cell arrangement. The temperature dependence of the ClONO2 absorption spectrum shows very broad structure. The amplitude of the temperature dependence relative to that at 296 K is weak at short wavelengths, < 2 % at 215 nm and 220 K, but significant at the wavelengths important in the stratosphere, approximately 30 % at 325 nm and 220 K. Our ClONO2 absorption cross section data are in good general agreement with the previous measurements of Molina and Molina [1979]. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP BURKHOLDER, JB (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80309, USA. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 8 TC 42 Z9 42 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1994 VL 21 IS 7 BP 585 EP 588 DI 10.1029/93GL03303 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NE512 UT WOS:A1994NE51200020 ER PT J AU APPELL, GF MERO, TN BETHEM, TD FRENCH, GW AF APPELL, GF MERO, TN BETHEM, TD FRENCH, GW TI THE DEVELOPMENT OF A REAL-TIME PORT INFORMATION-SYSTEM SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article AB A port information system was developed for Tampa Bay, FL, that provides data in real time. Current, water level, and weather systems measure various parameters from around the bay and report at 6-min intervals via a packet-modern-controlled telemetry system. A central receiving station and data acquisition system process the data and make it available in various formats. A voice data response system provides immediate access to the data via touchtone telephone. A voice processor is used to compose phrases that provide a user with environmental information based on the selection made from the voice menu. The design and development of all aspects of the system are described. This system has proven to be a valuable asset to the local and regional marine community, providing information for safe navigation, oil spills, search and rescue, fishing, and existing weather conditions. RP APPELL, GF (reprint author), NOAA,NATL OCEAN SERV,OFF OCEAN & EARTH SCI,OCEAN SYST DEV GRP,SILVER SPRING,MD 20910, USA. NR 6 TC 4 Z9 4 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 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1994 VL 19 IS 2 BP 149 EP 157 DI 10.1109/48.286636 PG 9 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA NR065 UT WOS:A1994NR06500001 ER PT J AU SHANG, EC WANG, YY AF SHANG, EC WANG, YY TI TOMOGRAPHIC INVERSION OF THE EL-NINO PROFILE BY USING A MATCHED-MODE PROCESSING (MMP) METHOD SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article ID OCEAN ACOUSTIC TOMOGRAPHY; SOURCE LOCALIZATION; DEPTH ESTIMATION; GROUP-VELOCITY; SHALLOW-WATER; WAVE-GUIDES; RANGE; SPACE AB A high-resolution mode-matching (HRMM) estimator is used to invert El Nino profile perturbations. By matching a proper set of modal travel time perturbations in a 2-D parameter space constructed by the first two coefficients of the empirical orthogonal function (EOF), the El Nino profile can be efficiently inverted. As contrasted with the conventional linear inversion scheme, the performance of the matched-mode scheme is significantly improved because the nonlinearity of the modal travel time perturbation has been taken into account. RP SHANG, EC (reprint author), UNIV COLORADO,NOAA,WAVE PROPAGAT LAB,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303, USA. NR 22 TC 8 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1994 VL 19 IS 2 BP 208 EP 213 DI 10.1109/48.286643 PG 6 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA NR065 UT WOS:A1994NR06500008 ER PT J AU FIALA, J LUMIA, R AF FIALA, J LUMIA, R TI THE EFFECT OF TIME-DELAY AND DISCRETE CONTROL ON THE CONTACT STABILITY OF SIMPLE POSITION CONTROLLERS SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Note AB By analysis of the driving-point admittane, it is shown how time delays and discrete control can create instabilities for a simple position controller in contact with the environment. The lowest frequency of contact instability due to time delay or sampling is determined analytically. It is shown bow mechanical compliance between the motor and point of contact can eliminate these instabilities. To achieve the best relative stability when contacting arbitrary environments, the mechanical/control design of manipulators should maintain a critical relationship between the frequency of the compliant mode and a frequency associated with contact instability. RP FIALA, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 2 Z9 2 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 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD APR PY 1994 VL 39 IS 4 BP 870 EP 873 DI 10.1109/9.286273 PG 4 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA NH601 UT WOS:A1994NH60100028 ER PT J AU STENBAKKEN, GN SOUDERS, TM AF STENBAKKEN, GN SOUDERS, TM TI DEVELOPING LINEAR ERROR MODELS FOR ANALOG DEVICES SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB Techniques are presented for developing linear error models for analog and mixed-signal devices. A simulation program developed to understand the modeling process is described, and results of simulations are presented. Methods for optimizing the size of empirical error models based on simulated error analyses are included. Once established, the models can be used in a comprehensive approach for optimizing the testing of the subject devices. Models are developed using data from a group of 13-bit A/D converters and compared with the simulation results. RP STENBAKKEN, GN (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 6 TC 27 Z9 27 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1994 VL 43 IS 2 BP 157 EP 163 DI 10.1109/19.293413 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA NU259 UT WOS:A1994NU25900010 ER PT J AU ROSENTHAL, PA GROSSMAN, EN AF ROSENTHAL, PA GROSSMAN, EN TI TERHERTZ SHAPIRO STEPS IN HIGH-TEMPERATURE SNS JOSEPHSON-JUNCTIONS SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT 4th International Symposium on Space Terahertz Technology CY MAR, 1993 CL UNIV CALIF LOS ANGELES, LOS ANGELES, CA SP NASA, OFF ADV CONCEPTS & TECHNOL, IEEE, MICROWAVE THEORY & TECH SOC, UNIV MICHIGAN, NASA CTR SPACE TERAHERTZ TECHNOL, UCLA CTR HIGH FREQUENCY ELECTR HO UNIV CALIF LOS ANGELES ID SUPERCONDUCTING TUNNEL-JUNCTIONS; WEAK LINKS; NOISE; MICROBRIDGES; RESISTANCE; DC AB We have studied the far infrared behavior of high-T(c) superconductor-normal metal-superconductor (SNS) microbridges with T(c) > 85 K and critical current-resistance products (I(c)R(N)) as high as 10 mV at 4 K. These are the highest I(c)R(N) products reported to date for microfabricated Josephson junctions of any material. The junctions were integrated at the feeds of planar log-periodic antennas made from Au thin films. The junctions had dc normal state resistances R(N) between 6 and 38 OMEGA, reasonably well matched to the antenna's estimated RF impedance of 53 OMEGA. Far infrared laser radiation at 404, 760, and 992 GHz induced distinct Shapiro steps (i.e. constant voltage steps at voltages n(hf/2e), n = 1, 2, ...) in the current voltage characteristics as well as modulation of the critical current. Steps were observed at voltages up to 17 mV and 6 mV, at temperatures of 9 K and 57 K, respectively. This corresponds to maximum Josephson oscillation frequencies of 8 and 3 THz at these temperatures. These are the first far infrared measurements performed on high T(c) junctions. Measurements of the power, frequency, and temperature dependence of the Shapiro steps are presented and discussed in the context of a resistively and capacitively shunted junction (RCSJ) model. A value of 4.5 fF for the junction capacitance is inferred from the hysteresis of the slightly underdamped current-voltage characteristics. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP ROSENTHAL, PA (reprint author), ADV FUEL RES INC,E HARTFORD,CT, USA. NR 24 TC 34 Z9 34 U1 1 U2 3 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 APR PY 1994 VL 42 IS 4 BP 707 EP 714 DI 10.1109/22.285085 PN 2 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA NM299 UT WOS:A1994NM29900003 ER PT J AU TOYOKUNI, S MORI, T DIZDAROGLU, M AF TOYOKUNI, S MORI, T DIZDAROGLU, M TI DNA-BASE MODIFICATIONS IN RENAL CHROMATIN OF WISTAR RATS TREATED WITH A RENAL CARCINOGEN, FERRIC NITRILOTRIACETATE SO INTERNATIONAL JOURNAL OF CANCER LA English DT Article ID HYDROGEN-PEROXIDE; MAMMALIAN CHROMATIN; LIPID-PEROXIDATION; OXIDATIVE DAMAGE; CELL CARCINOMA; NEPHROTOXICITY; KIDNEY; 8-HYDROXYDEOXYGUANOSINE; INDUCTION; PRODUCTS AB Ferric nitrilotriacetate (Fe-NTA) causes renal proximal tubular necrosis, a consequence of iron ion-mediated free-radical-associated damage, that finally leads to a high incidence of renal adenocarcinoma in male rats and mice. We have investigated the levels of typical hydroxyl radical-induced DNA base modifications in renal chromatin of male Wistar rats treated with a single or repeated administrations of Fe-NTA. Five pyrimidine-derived and 5 purine-derived modified DNA bases were identified and quantified by gas chromatography/mass spectrometry with selected-ion monitoring. The modified bases were 5-hydroxy-5-methylhydantoin, 5-(hydroxymethyl)uracil, 5-hydroxycytosine, thymine glycol, 5,6-dihydroxyuracil, 4,6-diamino-5-formamidopyrimidine, 8-hydroxyadenine, xanthine, 2-hydroxyadenine and 8-hydroxyguanine. The amounts of most of these compounds were significantly increased over control levels in renal chromatin of Fe-NTA-treated rats as measured 3 and 24 hr after treatment. Elevated levels of modified bases were accompanied by proximal tubular necrosis. On the 19th day, however, accumulation of modified DNA bases was not observed. Morphologically, scattered karyomegalic cells were seen in the proximal tubules, but necrosis was rarely found. Some of the identified DNA base lesions are known to be promutagenic, although others have not been investigated. Presence of modified DNA bases concomitant with necrosis and regeneration of the renal proximal tubules may be a critical step in Fe-NTA-induced carcinogenesis. (C) 1994 Wiley-Liss, Inc. C1 UNIV OSAKA PREFECTURE,ADV SCI & TECHNOL RES INST,DIV RADIAT CHEM,SAKAI,OSAKA 593,JAPAN. NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RP TOYOKUNI, S (reprint author), KYOTO UNIV,FAC MED,DEPT PATHOL,SAKYO KU,KYOTO 606,JAPAN. RI Toyokuni, Shinya/C-1358-2010 OI Toyokuni, Shinya/0000-0002-5757-1109 NR 30 TC 138 Z9 139 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7136 J9 INT J CANCER JI Int. J. Cancer PD APR 1 PY 1994 VL 57 IS 1 BP 123 EP 128 DI 10.1002/ijc.2910570122 PG 6 WC Oncology SC Oncology GA NE128 UT WOS:A1994NE12800021 PM 8150530 ER PT J AU FIALA, JC LUMIA, R ROBERTS, KJ WAVERING, AJ AF FIALA, JC LUMIA, R ROBERTS, KJ WAVERING, AJ TI TRICLOPS - A TOOL FOR STUDYING ACTIVE VISION SO INTERNATIONAL JOURNAL OF COMPUTER VISION LA English DT Article ID EYE AB The design, performance, and application of The Real-time, Intelligently ControLled, Optical Positioning (TRICLOPS) are described in this article. TRICLOPS is a multiresolution trinocular camera-pointing system which provides a center wide-angle view camera and two higher-resolution vergence cameras. It is a direct-drive system that exhibits dynamic performance comparable to the human visual system. The mechanical design and performance of various active vision systems are discussed and compared to those of TRICLOPS. The multiprocessor control system for TRICLOPS is described. The kinematics of the device are also discussed and calibration methods are given. Finally, as an example of real-time visual control, a problem in visual tracking with TRICLOPS is examined. In this example, TRICLOPS is shown to be capable of tracking a ball moving at 3 m/s, which results in rotational velocities of the vergence cameras in excess of 6 rad/s (344 deg/s). RP FIALA, JC (reprint author), NATL INST STAND & TECHNOL,DIV ROBOT SYST,GAITHERSBURG,MD 20899, USA. NR 29 TC 16 Z9 16 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0920-5691 J9 INT J COMPUT VISION JI Int. J. Comput. Vis. PD APR PY 1994 VL 12 IS 2-3 BP 231 EP 250 DI 10.1007/BF01421204 PG 20 WC Computer Science, Artificial Intelligence SC Computer Science GA NL558 UT WOS:A1994NL55800005 ER PT J AU DESROSIERS, MF LE, FG MCLAUGHLIN, WL AF DESROSIERS, MF LE, FG MCLAUGHLIN, WL TI INTER-LABORATORY TRIALS OF THE EPR METHOD FOR THE DETECTION OF IRRADIATED MEATS CONTAINING BONE SO INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY LA English DT Article DE ESR; FOOD; FOOD CONTROL METHOD; IDENTIFICATION; INTERNATIONAL METHOD PROTOCOL; LABELING COMPLIANCE; TEST EVALUATION ID IDENTIFICATION AB Three international trials on the use of electron paramagnetic resonance (EPR) to detect irradiated meats containing bone were sponsored as part of a coordinated research programme by the International Atomic Energy Agency. In these trials, 11 laboratories used EPR to examine a total of 154 bone samples from three different meats. In one of the trials food irradiation processing conditions were simulated. The results were 100% successful for identifying both irradiated and unirradiated bones. A protocol for the EPR method is provided. RP DESROSIERS, MF (reprint author), US TECHNOL ADM,NATL INST STAND & TECHNOL,PHYS LAB,DIV IONIZING RADIAT,GAITHERSBURG,MD 20899, USA. NR 5 TC 11 Z9 11 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0950-5423 J9 INT J FOOD SCI TECH JI Int. J. Food Sci. Technol. PD APR PY 1994 VL 29 IS 2 BP 153 EP 159 PG 7 WC Food Science & Technology SC Food Science & Technology GA NT568 UT WOS:A1994NT56800005 ER PT J AU MOUNTAIN, RD AF MOUNTAIN, RD TI SIMULATIONS OF GLASS-FORMING LIQUIDS - WHAT HAS BEEN LEARNED SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C-PHYSICS AND COMPUTERS LA English DT Article; Proceedings Paper CT 2nd IMACS Conference on Computational Physics CY OCT 06-09, 1993 CL ST LOUIS, MO SP INT ASSOC MATH & COMP SIMULAT, ST LOUIS UNIV, PARKS COLL ID MOLECULAR-DYNAMICS; SUPERCOOLED LIQUIDS; TRANSITION; RELAXATION; FLUID AB Molecular dynamics simulations of supercooled fluid mixtures of soft-spheres and of Lennard-Jones particles have revealed the existence of a kinetic transition that occurs above the glass transition temperature. This transition appears to be thermodynamic in origin. It is associated with a change in the local mobility of the particles. The basis for these conclusions is discussed. RP MOUNTAIN, RD (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C-Phys. Comput. PD APR PY 1994 VL 5 IS 2 BP 247 EP 249 DI 10.1142/S0129183194000258 PG 3 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA NR061 UT WOS:A1994NR06100015 ER PT J AU THOMPSON, PE GODBEY, D HOBART, K GLASER, E KENNEDY, T TWIGG, M SIMONS, D AF THOMPSON, PE GODBEY, D HOBART, K GLASER, E KENNEDY, T TWIGG, M SIMONS, D TI PARAMETRIC INVESTIGATION OF SI1-XGEX/SI MULTIPLE-QUANTUM-WELL GROWTH SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article; Proceedings Paper CT 5th International Symposium on Silicon Molecular Beam Epitaxy (SIMBE-5), at the 1993 International Conference on Solid State Devices and Materials (SSDM 93) CY AUG 30-SEP 01, 1993 CL NIPPON CONVENT CTR, MAKUHARI MESSE, JAPAN SP JAPAN SOC APPL PHYS HO NIPPON CONVENT CTR DE SI1-XGEX/SI MULTIPLE QUANTUM WELLS; PHOTOLUMINESCENCE; MOLECULAR BEAM EPITAXY; SECONDARY ION MASS SPECTROMETRY ID MOLECULAR-BEAM EPITAXY; CHEMICAL-VAPOR-DEPOSITION; MAGNETIC-RESONANCE; PHOTOLUMINESCENCE; LUMINESCENCE; SILICON AB Si0.8Ge0.2/Si multiple quantum wells (3 nm/30 nm) have been grown by molecular beam epitaxy and have been characterized using photoluminescence (PL), secondary ion mass spectrometry, and transmission electron microscopy. A parametric investigation relating the growth conditions to the PL was carried out. The existence of phonon-resolved band-edge PL appears to be strongly related to the background impurity concentration. The connection between phonon-resolved band-edge PL and higher substrate growth temperatures is probably due to the temperature- dependent incorporation of impurities. In the as-grown samples a correlation of the broad PL with platelet density in the quantum wells was observed. The broad PL may be associated with Cr at the platelets since a high temperature (710-degrees-C) anneal extinguished the broad PL and caused a reduction in the Cr found in the quantum wells, but had no effect on the platelet density. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP THOMPSON, PE (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 14 TC 9 Z9 9 U1 0 U2 1 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD APR PY 1994 VL 33 IS 4B BP 2317 EP 2321 DI 10.1143/JJAP.33.2317 PG 5 WC Physics, Applied SC Physics GA NR959 UT WOS:A1994NR95900037 ER PT J AU ZACHARIAH, MR BURGESS, DRF AF ZACHARIAH, MR BURGESS, DRF TI STRATEGIES FOR LASER-EXCITED FLUORESCENCE SPECTROSCOPY - MEASUREMENTS OF GAS-PHASE SPECIES DURING PARTICLE FORMATION SO JOURNAL OF AEROSOL SCIENCE LA English DT Article ID FLAMES; OH AB Characterization of gas phase species is of fundamental importance to a greater understanding of ps to particle conversion processes of interest to materials synthesis. This paper describes the use of Laser Excited Fluorescence as an in situ method for characterization of gas phase species in a densely laden particle forming flow. The method provides for non-invasive, high spatial resolution measurements in a high temperature hostile environment. Examples of the application of the method will be described for the measurement of OH and SiO in a silica particle forming high temperature flow. RP ZACHARIAH, MR (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 16 TC 25 Z9 25 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD APR PY 1994 VL 25 IS 3 BP 487 EP 497 DI 10.1016/0021-8502(94)90066-3 PG 11 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NQ279 UT WOS:A1994NQ27900005 ER PT J AU BRAND, PC PRASK, HJ AF BRAND, PC PRASK, HJ TI NEW METHODS FOR THE ALIGNMENT OF INSTRUMENTATION FOR RESIDUAL-STRESS MEASUREMENTS BY MEANS OF NEUTRON-DIFFRACTION SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB Adequate alignment of instrumentation and specimens is imperative for the successful performance of residual-stress measurements by means of neutron diffraction. This paper presents a number of alignment methods that enable the user to align reproducibly a stress-measurement setup and a specimen positioned therein. Most of these methods employ the position and the direction of the incident neutron beam as their primary source of geometric reference. A mathematical description for each of the proposed alignment steps is given, which makes the alignment quantitative and enables quantitative assessment of the alignment quality after each alignment step. Examples from actual practice show that the alignment quality that can be achieved using these methods is better than 0.05 mm for translations and better than 0.05-degrees for rotations. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. RP BRAND, PC (reprint author), UNIV MARYLAND,COLL PK,MD 20742, USA. NR 5 TC 9 Z9 10 U1 0 U2 1 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 APR 1 PY 1994 VL 27 BP 164 EP 176 DI 10.1107/S0021889893007605 PN 2 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA ND161 UT WOS:A1994ND16100007 ER PT J AU XU, Q QIU, CJ YU, JX AF XU, Q QIU, CJ YU, JX TI ADJOINT-METHOD RETRIEVALS OF LOW-ALTITUDE WIND FIELDS FROM SINGLE-DOPPLER REFLECTIVITY MEASURED DURING PHOENIX-II SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB The simple adjoint method of Qiu and Xu is upgraded and tested with the Phoenix II data for retrieving the low-altitude winds from the movements of reflectivity patterns measured by a single-Doppler radar. The upgraded method uses an improved reflectivity advection equation that contains not only the advection terms but also the eddy diffusion terms. The test results show that (i) utilizing multiple-time-level data provides more information and, thus, increases the accuracy of the retrieval; (ii) the adjoint method can retrieve not only the time-mean (or running mean) velocity field but also the coefficients of horizontal and vertical eddy diffusion (retrieving the eddy coefficients improves the velocity retrieval); (iii) the retrieval is improved by judiciously setting the weights in the cost function and by spatial noise-filtering and temporal interpolation of the data; (iv) the retrieval is further improved when the observed radial wind (along the radar beam) is used. RP XU, Q (reprint author), UNIV OKLAHOMA,NOAA,COOPERAT INST MESOSCALE METEOROL STUDIES,ROOM 1110,100 E BOYD,NORMAN,OK 73019, USA. NR 0 TC 44 Z9 59 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1994 VL 11 IS 2 BP 275 EP 288 DI 10.1175/1520-0426(1994)011<0275:AMROLA>2.0.CO;2 PN 1 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA NE047 UT WOS:A1994NE04700004 ER PT J AU XU, Q QIU, CJ AF XU, Q QIU, CJ TI SIMPLE ADJOINT METHODS FOR SINGLE-DOPPLER WIND ANALYSIS WITH A STRONG CONSTRAINT OF MASS CONSERVATION SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Three schemes are developed to incorporate a strong constraint of (incompressible) mass conservation into the basic scheme (scheme B) of the simple adjoint method of Qiu and Xu for retrieving the time-mean wind field from a sequence of single-Doppler scans. In the first scheme (S1), the two-dimensional wind field on a surface normal to the radar beam is partitioned into an irrotational component expressed by the velocity potential and a nondivergent component expressed by the streamfunction. The velocity potential can be obtained directly from single-Doppler observations, and the streamfunction is retrieved by the adjoint method. In this way, the retrieved wind field satisfies the mass conservation equation precisely. The second scheme (S2) is the same as scheme S1 except that a spectral expression is used to replace the grid representation of the streamfunction. The third scheme (S3) imposes a strong mass conservation constraint through a postadjustment after the wind field is retrieved by scheme B with a weak mass conservation constraint. These schemes are tested with artificial data. Their relative merits and disadvantages are examined and compared in terms of accuracy, convergence rate, sensitivity to errors, and computational efficiency. RP XU, Q (reprint author), UNIV OKLAHOMA,NOAA,COOPERAT INST MESOSCALE METEOROL STUDIES,ROOM 1110,100 E BOYD,NORMAN,OK 73019, USA. NR 0 TC 20 Z9 30 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 APR PY 1994 VL 11 IS 2 BP 289 EP 298 DI 10.1175/1520-0426(1994)011<0289:SAMFSD>2.0.CO;2 PN 1 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA NE047 UT WOS:A1994NE04700005 ER PT J AU XU, Q QIU, CJ YU, JX AF XU, Q QIU, CJ YU, JX TI ADJOINT-METHOD RETRIEVALS OF LOW-ALTITUDE WIND FIELDS FROM SINGLE-DOPPLER WIND DATA SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note AB The simple adjoint method of Qiu and Xu is extended and used to retrieve the low-altitude horizontal wind field from single-Doppler radial wind data measured during the Phoenix II field experiment. Since the extended method uses only the radial momentum equation on a low-altitude horizontal plane with a weak nondivergence constraint for the horizontal winds, the pressure gradient and vertical advection are treated as an unknown residual forcing. The test results show that (i) the method can retrieve the low-altitude time-mean (or running mean) horizontal winds (averaged over a period of several sequential radar scans) from single-Doppler radial wind data; (ii) retrieving the time-mean part of the unknown residual forcing term improves the wind retrieval; (iii) the detailed data treatments and proper settings of the weights considered in Xu et al. remain useful for improving the retrieval. RP XU, Q (reprint author), UNIV OKLAHOMA,NOAA,CIMMS,100 E BOYD,RM 1110,NORMAN,OK 73109, USA. NR 0 TC 35 Z9 46 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 APR PY 1994 VL 11 IS 2 BP 579 EP 585 DI 10.1175/1520-0426(1994)011<0579:AMROLA>2.0.CO;2 PN 2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA NE049 UT WOS:A1994NE04900013 ER PT J AU TATARSKAIA, MS TATARSKII, VV TATARSKII, VI WESTWATER, ER AF TATARSKAIA, MS TATARSKII, VV TATARSKII, VI WESTWATER, ER TI QUALITY-CONTROL OF GROUND-BASED RADIOMETRIC OBSERVATIONS OF INTEGRATED MOISTURE USING SURFACE METEOROLOGICAL OBSERVATIONS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note AB A method of quality control is presented for ground-based, dual-channel microwave measurements of integrated moisture. Such a method is necessary to eliminate spurious data arising from calibration uncertainties, electronic fluctuations, and strong rain and melting snow on the radiometer antenna. The method is based on the prediction of integrated moisture content from surface measurements of temperature and dewpoint temperature. The statistical prediction was based on regression using a carefully screened multiyear training set of surface meteorological observations, and radiosonde and dual-channel radiometric measurements of moisture. Five years of twice-daily data (six years for the summer months) from Denver, Colorado, as well as data obtained from special experiments at Elbert and Platteville, Colorado, formed the training set. Both linear and nonlinear predictions were compared. The method was applied to independent data obtained during 1991-92 experiments at the three locations. The method predicted data quality with a 91% accuracy rate. C1 NOAA,ERL,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303. NR 0 TC 0 Z9 0 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 APR PY 1994 VL 11 IS 2 BP 599 EP 607 DI 10.1175/1520-0426(1994)011<0599:QCOGBR>2.0.CO;2 PN 2 PG 9 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA NE049 UT WOS:A1994NE04900016 ER PT J AU TOMAZIC, BB BROWN, WE SCHOEN, FJ AF TOMAZIC, BB BROWN, WE SCHOEN, FJ TI PHYSICOCHEMICAL PROPERTIES OF CALCIFIC DEPOSITS ISOLATED FROM PORCINE BIOPROSTHETIC HEART-VALVES REMOVED FROM PATIENTS FOLLOWING 2-13 YEARS FUNCTION (VOL 28, PG 527, 1994) SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Correction, Addition C1 BRIGHAM & WOMENS HOSP,DEPT PATHOL,BOSTON,MA 02115. RP TOMAZIC, BB (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 1 TC 2 Z9 2 U1 0 U2 2 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 APR PY 1994 VL 28 IS 4 BP 527 EP 527 DI 10.1002/jbm.820280416 PG 1 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA NA517 UT WOS:A1994NA51700015 ER PT J AU DEFIBAUGH, DR MORRISON, G WEBER, LA AF DEFIBAUGH, DR MORRISON, G WEBER, LA TI THERMODYNAMIC PROPERTIES OF DIFLUOROMETHANE SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB The pressure-volume-temperature (PVT) behavior of difluoromethane (R32) has been measured using a vibrating tube densimeter apparatus and a Burnett/isochoric apparatus. Liquid PVT data from the vibrating tube densimeter ranged in temperature from 242 to 348 K with a pressure range of 2000-6500 kPa. Data from the Burnett apparatus consisted of 11 isochores for the gas and supercritical fluid, along with vapor pressure measurements. The temperature ranged from 268 to 373 K. The gas-phase data are correlated with a virial equation of state. The compressed liquid data are fit with an abbreviated form of the modified Benedict-Webb-Rubin (mBWR) equation. A table of thermodynamic properties is presented for the saturated liquid and vapor states. RP DEFIBAUGH, DR (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 18 TC 51 Z9 51 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD APR PY 1994 VL 39 IS 2 BP 333 EP 340 DI 10.1021/je00014a032 PG 8 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA NH509 UT WOS:A1994NH50900032 ER PT J AU SETTLE, JL GREENBERG, E HUBBARD, WN OHARE, PAG AF SETTLE, JL GREENBERG, E HUBBARD, WN OHARE, PAG TI THE STANDARD MOLAR ENTHALPY OF FORMATION OF LIQUID-HYDROGEN FLUORIDE DELTA(F)H(M)(DEGREES)(HF, L) AT THE TEMPERATURE 298.15-K DETERMINED BY DIRECT COMBINATION OF THE ELEMENTS IN A FLUORINE-BOMB CALORIMETER SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article C1 NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 43 TC 1 Z9 1 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD APR PY 1994 VL 26 IS 4 BP 435 EP 448 DI 10.1006/jcht.1994.1053 PG 14 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA NE609 UT WOS:A1994NE60900011 ER PT J AU MILLY, PCD DUNNE, KA AF MILLY, PCD DUNNE, KA TI SENSITIVITY OF THE GLOBAL WATER CYCLE TO THE WATER-HOLDING CAPACITY OF LAND SO JOURNAL OF CLIMATE LA English DT Article ID AMAZON DEFORESTATION; CLIMATE CHANGE; SOIL-MOISTURE AB The sensitivity of the global water cycle to the water-holding capacity of the plant-root zone of continental soils is estimated by simulations using a mathematical model of the general circulation of the atmosphere, with prescribed ocean surface temperatures and prescribed cloud. With an increase of the globally constant storage capacity, evaporation from the continents rises and runoff falls, because a high storage capacity enhances the ability of the soil to store water from periods of excess for later evaporation during periods of shortage. In addition to this direct effect, atmospheric feedbacks associated with the resulting higher precipitation and lower potential evaporation drive further changes in evaporation and runoff. Most of the changes in evaporation and runoff occur in the tropics and in the northern middle-latitude rain belts. Global evaporation from land increases by about 7 cm for each doubling of storage capacity in the range from less than 1 cm to almost 60 cm. Sensitivity is negligible for capacity above 60 cm. In the tropics and in the extratropics, the increased continental evaporation is split, in approximately equal parts, between increased continental precipitation and decreased convergence of atmospheric water vapor from ocean to land. In the tropics, this partitioning is strongly affected by induced circulation changes, which are themselves forced by changes in latent heating. The increased availability of water at the continental surfaces leads to an intensification of the Hadley circulation and a weakening of the monsoonal circulations. In the northern middle and high latitudes, the increased continental evaporation moistens the atmosphere. This change in humidity of the atmosphere is greater above the continents than above the oceans, and the resulting reduction in the sea-land humidity gradient causes a decreased onshore transport of water vapor by transient eddies. Results established here may have implications for certain problems in global hydrology and climate dynamics, including the effects of water resource development on global precipitation, climatic control of plant rooting characteristics, climatic effects of tropical deforestation, and climate-model errors induced by errors in land-surface hydrologic parameterizations. RP MILLY, PCD (reprint author), NOAA,GFDL,US GEOL SURVEY,POB 308,PRINCETON,NJ 08542, USA. NR 21 TC 149 Z9 157 U1 7 U2 25 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1994 VL 7 IS 4 BP 506 EP 526 DI 10.1175/1520-0442(1994)007<0506:SOTGWC>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG434 UT WOS:A1994NG43400003 ER PT J AU NEMESURE, S CESS, RD DUTTON, EG DELUISI, JJ LI, ZQ LEIGHTON, HG AF NEMESURE, S CESS, RD DUTTON, EG DELUISI, JJ LI, ZQ LEIGHTON, HG TI IMPACT OF CLOUDS ON THE SHORTWAVE RADIATION BUDGET OF THE SURFACE ATMOSPHERE SYSTEM FOR SNOW-COVERED SURFACES SO JOURNAL OF CLIMATE LA English DT Article AB Recent data from the Earth Radiation Budget Experiment (ERBE) have raised the question as to whether or not the addition of clouds to the atmospheric column can decrease the top-of-the-atmosphere (TOA) albedo over bright snow-covered sur-faces. To address this issue, ERBE shortwave pixel measurements have been collocated with surface insolation measurements made at two snow-covered locations: the South Pole and Saskatoon, Saskatchewan. Both collocated datasets show a negative correlation (with solar zenith angle variability removed) between TOA albedo and surface insolation. Because increased cloudiness acts to reduce surface insolation, these negative correlations demonstrate that clouds increase the TOA albedo at both snow-covered locations. C1 SUNY STONY BROOK,MARINE SCI RES CTR,INST TERR & PLANETARY ATMOSPHERES,STONY BROOK,NY 11794. NOAA,ENVIRONM RES LABS,CLIMATE & DIAGNOST LAB,BOULDER,CO 80303. MCGILL UNIV,DEPT ATMOSPHER & OCEAN SCI,MONTREAL H3A 2T5,QUEBEC,CANADA. CANADA CTR REMOTE SENSING,OTTAWA,ON,CANADA. RI Li, Zhanqing/F-4424-2010 OI Li, Zhanqing/0000-0001-6737-382X NR 12 TC 17 Z9 17 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1994 VL 7 IS 4 BP 579 EP 585 DI 10.1175/1520-0442(1994)007<0579:IOCOTS>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG434 UT WOS:A1994NG43400009 ER PT J AU LIVEZEY, RE BARNSTON, AG GRUZA, GV RANKOVA, EY AF LIVEZEY, RE BARNSTON, AG GRUZA, GV RANKOVA, EY TI COMPARATIVE SKILL OF 2 ANALOG SEASONAL TEMPERATURE PREDICTION SYSTEMS - OBJECTIVE SELECTION OF PREDICTORS SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION; CLIMATE; ANOMALIES; FORECASTS; ATLANTIC; QBO AB Analog prediction systems developed in the United States and the former Soviet Union are compared for U.S. seasonal temperature prediction. Of primary interest is the viability of the Russian ''optimization'' concept for a priori selection of U.S. seasonal analog forecast predictors. Optimization is a specific technique for choosing predictor variables for analog matching on a forecast-by-forecast basis. Validation of this procedure would lead to more efficient design of analog prediction models and the elimination of some subjectivity in the process that inevitably results in overstatements in realizable skill. The procedure's effectiveness was tested using predictor and predictand datasets from the U.S. system in a cross-validation framework. Skills of different models were assessed on the basis of 40 seasonal forecasts at 92 U.S. stations. The Russian system (called GRAN for ''Group Analog'') was first run without optimization using the a posteriori selected predictors used in the U.S. system. A version of the U.S. system (without use of antianalogs) that is conceptually very similar to GRAN without optimization was run for comparison in this calibration step. The results reveal that these systems perform in a nearly identical manner when predictor and predictand datasets are the same. Next GRAN forecasts were made using all available predictors and then using only predictors selected via optimization. The results not only show that objective a priori predictor selection by optimization is just as effective (in terms of skill) as subjective a posteriori selection but also suggest it may produce superior results in summer forecasts. C1 RUSSIAN ACAD SCI,INST GLOBAL CLIMATE & ECOL,MOSCOW,RUSSIA. RP LIVEZEY, RE (reprint author), NOAA,NWS,NMC,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. NR 20 TC 13 Z9 16 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1994 VL 7 IS 4 BP 608 EP 615 DI 10.1175/1520-0442(1994)007<0608:CSOTAS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NG434 UT WOS:A1994NG43400011 ER PT J AU GIEBULTOWICZ, TM FASCHINGER, W NUNEZ, V KLOSOWSKI, P BAUER, G SITTER, H FURDYNA, JK AF GIEBULTOWICZ, TM FASCHINGER, W NUNEZ, V KLOSOWSKI, P BAUER, G SITTER, H FURDYNA, JK TI ANTIFERROMAGNETIC SPIN ORDERING AND INTERLAYER MAGNETIC CORRELATIONS IN MNTE/CDTE SUPERLATTICES SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 6th International Conference on I-VI Compounds and Related Optoelectronic Materials CY SEP 13-17, 1993 CL NEWPORT, RI ID 4-COMPONENT VECTOR MODELS; PHYSICAL REALIZATIONS; 1ST-ORDER TRANSITIONS; EPSILON-EXPANSION; CDTE-ZNTE; STRAIN; SYMMETRY AB Results of neutron scattering studies on MnTe/CdTe superlattices with ultrathin non-magnetic CdTe ''barriers'' are presented and compared with data from earlier studies on MnSe/ZnSe, MnTe/ZnTe, and MnSe/ZnTe multilayers with thick non-magnetic spacers. The experiments revealed two qualitatively new effects - namely, (i) the existence of pronounced interlayer magnetic correlations in the case of the CdTe thickness corresponding to two single monolayers and (ii) the coexistence of two magnetic phases that never occurred simultaneously in the previously studied systems. C1 UNIV LINZ,INST EXPTL PHYS,A-4040 LINZ,AUSTRIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MARYLAND,COLL PK,MD 20742. RP GIEBULTOWICZ, TM (reprint author), UNIV NOTRE DAME,NOTRE DAME,IN 46556, USA. NR 14 TC 14 Z9 14 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 APR PY 1994 VL 138 IS 1-4 BP 877 EP 883 DI 10.1016/0022-0248(94)90924-5 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA NN997 UT WOS:A1994NN99700156 ER PT J AU BRUSH, LN MCFADDEN, GB CORIELL, SR AF BRUSH, LN MCFADDEN, GB CORIELL, SR TI THE EFFECT OF CRYSTALLINE ANISOTROPY ON PATTERN-FORMATION IN LASER-MELTED THIN SILICON FILMS SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID SURFACE-TENSION; SI; RECRYSTALLIZATION; MORPHOLOGIES; LIQUID AB When heated radiatively, thin silicon films on a cooled substrate can develop partially melted regions consisting of alternating parallel bands of liquid and solid phases separated by planar or nearly planar solid-liquid interfaces. As the power of the heat source increases, the lamellar array can break down, giving rise to a corrugated set of interface patterns. In this work we investigate the effect of surface tension anisotropy on nonlinear, finite amplitude pattern formation, extending previous results that have only included the effect of isotropic surface tension. Using weakly nonlinear perturbation theory, we show that parallel lamellar interfaces may become unstable with respect to the development of a finite amplitude traveling wave, due to the anisotropy in surface tension. However, for lamella aligned in special crystallographic orientations (corresponding to extrema in the surface tension) instability is time-independent. In the latter case, using a simple model for anisotropic surface tension, we show that if the alignment of the lamellar interfaces is an orientation having less than the average value of the interfacial energy, then a perturbation of the most dangerous wavenumber will bifurcate subcritically from the planar state, provided that the surface tension anisotropy is above a critical value. Furthermore, for larger anisotropy, the subcritical behavior becomes increasingly more severe. For those lamellar arrays having interfaces initially of higher than average interfacial energy, bifurcation of the most dangerous wavenumber is supercritical. By using a boundary integral method to obtain steady-state numerical solutions for nonplanar solid-liquid interfaces and by using eigenvalue calculations to determine the linear stability of the nonplanar interface shapes, we show the manner in which anisotropic surface tension alters the stability of shapes and influences the interaction between unstable modes. 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 16 TC 2 Z9 2 U1 0 U2 0 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 APR PY 1994 VL 137 IS 3-4 BP 355 EP 374 DI 10.1016/0022-0248(94)90972-5 PG 20 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA NE892 UT WOS:A1994NE89200006 ER PT J AU SNAIL, KA LU, ZP WEIMER, R HEBERLEIN, J PFENDER, E HANSSEN, LM AF SNAIL, KA LU, ZP WEIMER, R HEBERLEIN, J PFENDER, E HANSSEN, LM TI CONFIRMATION OF (113) FACETS ON DIAMOND GROWN BY CHEMICAL-VAPOR-DEPOSITION SO JOURNAL OF CRYSTAL GROWTH LA English DT Letter ID HIGH-TEMPERATURE AB Recent observations of {113} facets on diamond films grown epitaxially at high temperatures with a chemical vapor deposition (CVD) process have been confirmed. Cylinder growth experiments employing both oxygen-acetylene flames and a DC plasma torch show clear evidence of {113} facetting. These results lend additional support to the hypothesis that an earlier crystal growth theory developed for silicon CVD may also apply to diamond CVD. C1 UNIV MINNESOTA,DEPT MECH ENGN,MINNEAPOLIS,MN 55455. NATL INST STAND & TECHNOL,DIV RADIOMETR PHYS,GAITHERSBURG,MD 20899. RP SNAIL, KA (reprint author), USN,RES LAB,DIV OPT SCI,CODE 5622,WASHINGTON,DC 20375, USA. NR 10 TC 9 Z9 9 U1 0 U2 4 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 APR PY 1994 VL 137 IS 3-4 BP 676 EP 679 DI 10.1016/0022-0248(94)91014-6 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA NE892 UT WOS:A1994NE89200047 ER PT J AU SQUIRES, D AF SQUIRES, D TI FIRM BEHAVIOR UNDER INPUT RATIONING SO JOURNAL OF ECONOMETRICS LA English DT Article DE RATIONING; QUOTAS; VIRTUAL PRICES ID PROFIT FUNCTION; MODEL AB This paper uses the concept of virtual prices to evaluate the impact of an input quantity constraint, such as a ration or quantity control, upon the competitive multiproduct profit-maximizing firm's factor demand, output supply, multiproduct cost and revenue structures, marginal implicit valuations of fixed factors, and capacity utilization. The properties of the input-rationed and unrationed output supply and factor demand functions, costs, and capacity utilization are related, consistently describing behavior under both regimes. Both Hicksian and Marshallian functions are assessed. The potential effects of input rationing upon wet rice production and labor utilization in the islands of Indonesia off-Java serves as a case study. RP SQUIRES, D (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 32 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0304-4076 J9 J ECONOMETRICS JI J. Econom. PD APR PY 1994 VL 61 IS 2 BP 235 EP 257 DI 10.1016/0304-4076(94)90085-X PG 23 WC Economics; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Business & Economics; Mathematics; Mathematical Methods In Social Sciences GA NB644 UT WOS:A1994NB64400002 ER PT J AU BRILL, RW JONES, DR AF BRILL, RW JONES, DR TI THE INFLUENCE OF HEMATOCRIT, TEMPERATURE AND SHEAR RATE ON THE VISCOSITY OF BLOOD FROM HIGH-ENERGY-DEMAND TELEOST, THE YELLOWFIN TUNA THUNNUS ALBACARES SO JOURNAL OF EXPERIMENTAL BIOLOGY LA English DT Article DE BLOOD; VISCOSITY; HEMATOCRIT; YELLOWFIN TUNA; THUNNUS ALBACARES ID OXYGEN-TRANSPORT; KATSUWONUS-PELAMIS; SKIPJACK TUNA; RAINBOW-TROUT; BEHAVIORAL THERMOREGULATION; PLASMA VISCOSITY; METABOLIC RATES; WINTER FLOUNDER; ACUTE-HYPOXIA; FISH AB The high cardiac output, arterial blood pressure and cardiac energy demand of tuna make it likely that blood viscosity has an important influence on cardiovascular function. Furthermore, tuna regularly subject themselves to ambient temperature changes of 10 degrees C or more during their daily vertical migrations. They can also maintain muscle temperatures several degrees Celsius above ambient and reach maximum muscle temperatures of approximately 15 degrees C above ambient. The blood of tuna is, therefore, subjected to more frequent and rapid temperature changes than those that occur in other teleosts. Nothing is known, however, about the effects of temperature, shear rate or hematocrit on the viscosity of tuna blood. Viscosity of yellowfin tuna blood (hematocrits of 0-55%) was measured at 15, 25 and 35 degrees C and at shear rates of 45, 90, 225 and 450 s(-1) using a cone-plate viscometer. As found for the blood of other vertebrates, viscosity increased with increasing hematocrit. Viscosity also increased nonlinearly with decreasing shear rate, until a shear rate of 90s(-1) was reached. There was no significant increase in viscosity when shear rate was decreased further, to 45 s(-1). Because of the relatively flat hematocrit-viscosity curves, predicted optimal hematocrit curves were nearly flat above a hematocrit of approximately 30%. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822, USA. NR 54 TC 10 Z9 12 U1 0 U2 3 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE, CAMBS, ENGLAND CB4 4DL SN 0022-0949 J9 J EXP BIOL JI J. Exp. Biol. PD APR PY 1994 VL 189 BP 199 EP 212 PG 14 WC Biology SC Life Sciences & Biomedicine - Other Topics GA NF093 UT WOS:A1994NF09300012 ER PT J AU GONZALEZ, WD JOSELYN, JA KAMIDE, Y KROEHL, HW ROSTOKER, G TSURUTANI, BT VASYLIUNAS, VM AF GONZALEZ, WD JOSELYN, JA KAMIDE, Y KROEHL, HW ROSTOKER, G TSURUTANI, BT VASYLIUNAS, VM TI WHAT IS A GEOMAGNETIC STORM SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Review ID INTERPLANETARY MAGNETIC-FIELD; CORONAL MASS EJECTA; PHASE RING CURRENT; SOLAR-WIND; MAGNETOSPHERIC SUBSTORMS; SEMIANNUAL VARIATION; MEDIUM PARAMETERS; RADIAL DIFFUSION; ENERGY; MODEL AB After a brief review of magnetospheric and interplanetary phenomena for intervals with enhanced solar wind-magnetosphere interaction, an attempt is made to define a geomagnetic storm as an interval of time when a sufficiently intense and long-lasting interplanetary convection electric field leads, through a substantial energization in the magnetosphere-ionosphere system, to an intensified ring current sufficiently strong to exceed some key threshold of the quantifying storm time Dst index. The associated storm/substorm relationship problem is also reviewed. Although the physics of this relationship does not seem to be fully understood at this time, basic and fairly well established mechanisms of this relationship are presented and discussed. Finally, toward the advancement of geomagnetic storm research, some recommendations are given concerning future improvements in monitoring existing geomagnetic indices as well as the solar wind near Earth. C1 NAGOYA UNIV, SOLAR TERR ENVIRONM LAB, TOYOKAWA 442, JAPAN. NOAA, NATL GEOPHYS DATA CTR, BOULDER, CO 80303 USA. UNIV ALBERTA, DEPT PHYS, EDMONTON T6G 2G1, ALBERTA, CANADA. JET PROP LAB, PASADENA, CA 91109 USA. MAX PLANCK INST AERON, W-3411 KATLENBURG DUHM, GERMANY. RP NOAA, ENVIRONM RES LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 141 TC 837 Z9 862 U1 13 U2 83 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD APR 1 PY 1994 VL 99 IS A4 BP 5771 EP 5792 DI 10.1029/93JA02867 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NF580 UT WOS:A1994NF58000008 ER PT J AU YEH, KC MA, SY LIN, KH CONKRIGHT, RO AF YEH, KC MA, SY LIN, KH CONKRIGHT, RO TI GLOBAL IONOSPHERIC EFFECTS OF THE OCTOBER 1989 GEOMAGNETIC STORM SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TOTAL ELECTRON-CONTENT; LOW LATITUDE AURORAE; 13 MARCH 1989; MAGNETIC STORM; MAGNETOSPHERIC STORM; UPPER-ATMOSPHERE; GRAVITY-WAVES; F-REGION; DISTURBANCES; EQUATORIAL AB Based on a large data base from 40 ionosonde stations distributed worldwide and 12 total electron content stations, a case study is made on the global behavior of ionospheric responses to the great magnetic storm of October 1989. The magnetic storm was triggered by a solar flare with the largest class of X13/4B and started with a sudden storm commencement (ssc) at 0917 UT on October 20. After the initial phase the storm underwent two periods of maximum activities in the following 2 days. Low-latitude auroras were sighted and reported in widely separated areas in both northern and southern hemispheres. In response to these magnetic and auroral activities the ionosphere showed remarkable effects. Depending on the local time of ssc occurrence, the ionospheric response differed appreciably. Impressive changes were long-lasting, large-scale effects, such as the severe depressions of foF2 at higher latitudes, the temporary suppression of the equatorial anomaly and large horizontal gradients at certain latitudes. Also observed were positive storm effects of short duration during the post-sunset period in response to the onset of both ssc and main phase of the magnetic storm. These two positive storm effects showed different patterns suggesting different causal mechanisms. In addition, global propagation of large-scale traveling ionospheric disturbances (TIDs) was seen during 2 nights, identified by dramatic rises of h'F with periodic fluctuations. The equatorward propagation velocities of the TIDs varied between 330 m/s and 680 m/s for the east Asia region. C1 WUHAN UNIV,DEPT SPACE PHYS,WUHAN 430072,PEOPLES R CHINA. UNIV ILLINOIS,DEPT ELECT & COMP ENGN,URBANA,IL 61801. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303. NR 33 TC 50 Z9 51 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1994 VL 99 IS A4 BP 6201 EP 6218 DI 10.1029/93JA02543 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NF580 UT WOS:A1994NF58000045 ER PT J AU LU, G RICHMOND, AD EMERY, BA REIFF, PH DELABEAUJARDIERE, O RICH, FJ DENIG, WF KROEHL, HW LYONS, LR RUOHONIEMI, JM FRIISCHRISTENSEN, E OPGENOORTH, H PERSSON, MAL LEPPING, RP RODGER, AS HUGHES, T MCEWIN, A DENNIS, S MORRIS, R BURNS, G TOMLINSON, L AF LU, G RICHMOND, AD EMERY, BA REIFF, PH DELABEAUJARDIERE, O RICH, FJ DENIG, WF KROEHL, HW LYONS, LR RUOHONIEMI, JM FRIISCHRISTENSEN, E OPGENOORTH, H PERSSON, MAL LEPPING, RP RODGER, AS HUGHES, T MCEWIN, A DENNIS, S MORRIS, R BURNS, G TOMLINSON, L TI INTERHEMISPHERIC ASYMMETRY OF THE HIGH-LATITUDE IONOSPHERIC CONVECTION PATTERN SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; MAPPING ELECTRODYNAMIC FEATURES; INCOHERENT-SCATTER RADAR; DEPENDENT PLASMA-FLOW; ELECTRIC-FIELD; POLAR-CAP; BOUNDARY-LAYER; IMF-BY; PARTICLE-PRECIPITATION; LOCALIZED OBSERVATIONS AB The assimilative mapping of ionospheric electrodynamics technique has been used to derive the large-scale high-latitude ionospheric convection patterns simultaneously in both northern and southern hemispheres during the period of January 27-29, 1992. When the interplanetary magnetic field (IMF) B(z) component is negative, the convection patterns in the southern hemisphere are basically the mirror images of those in the northern hemisphere. The total cross-polar-cap potential drops in the two hemispheres are similar. When B(z) is positive and \B(y)\ > B(z), the convection configurations are mainly determined by B(y) and they may appear as normal ''two-cell'' patterns in both hemispheres much as one would expect under southward IMF conditions. However, there is a significant difference in the cross-polar-cap potential drop between the two hemispheres, with the potential drop in the southern (summer) hemisphere over 50% larger than that in the northern (winter) hemisphere. As the ratio of \B(y)\/B(z) decreases (less than one), the convection configuration in the two hemispheres may be significantly different, with reverse convection in the southern hemisphere and weak but disturbed convection in the northern hemisphere. By comparing the convection patterns with the corresponding spectrograms of precipitating particles, we interpret the convection patterns in terms of the concept of merging cells, lobe cells, and viscous cells. Estimates of the ''merging cell'' potential drops, that is, the potential ascribed to the opening of the dayside field lines, are usually comparable between the two hemispheres, as they should be. The ''lobe cell'' provides a potential between 8.5 and 26 kV and can differ greatly between hemispheres, as predicted. Lobe cells can be significant even for southward IMF, if \B(y)\ > \B(z)\. To estimate the potential drop of the ''viscous cells,'' we assume that the low-latitude boundary layer is on closed field lines. We find that this potential drop varies from case to case, with a typical value of 10 kV. If the source of these cells is truly a viscous interaction at the flank of the magnetopause, the process is likely spatially and temporally varying rather than steady state. C1 AUSTRALIA ANARCTIC DIV,KINGSTON,TAS,AUSTRALIA. SRI INT,MENLO PK,CA 94025. PHILLIPS LAB,BEDFORD,MA 01731. AUSTRALIAN GEOL SURVEY ORG,CANBERRA,AUSTRALIA. DANISH METEOROL INST,DK-2791 COPENHAGEN,DENMARK. NATL RES COUNCIL CANADA,HERZBERG INST ASTROPHYS,OTTAWA K1A 0R6,ONTARIO,CANADA. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. AEROSP CORP,LOS ANGELES,CA 90009. SWEDISH INST SPACE PHYS,S-75590 UPPSALA,SWEDEN. UNIV HOUSTON,DEPT SPACE PHYS & ASTRON,HOUSTON,TX 77251. BRITISH ANTARCTIC SURVEY,CAMBRIDGE CB3 0ET,ENGLAND. JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723. INST GEOL & NUCL SCI,CHRISTCHURCH 9,NEW ZEALAND. RP LU, G (reprint author), NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307, USA. RI Lu, Gang/A-6669-2011; Reiff, Patricia/D-2564-2014 OI Reiff, Patricia/0000-0002-8043-5682 NR 70 TC 88 Z9 90 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1994 VL 99 IS A4 BP 6491 EP 6510 DI 10.1029/93JA03441 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NF580 UT WOS:A1994NF58000067 ER PT J AU KUMAR, A GALLAWA, RL GOYAL, IC AF KUMAR, A GALLAWA, RL GOYAL, IC TI MODAL CHARACTERISTICS OF BENT DUAL-MODE PLANAR OPTICAL WAVE-GUIDES SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID ACOUSTOOPTIC FREQUENCY SHIFTER; FIELD DEFORMATION; 2-MODE FIBER; WAVE-GUIDES AB Modal characteristics of bent dual-mode planar optical waveguides are obtained. The bending-induced changes in the modal power distribution is found to be quite different for the two modes. Surprisingly, unlike the fundamental mode, bending causes the fractional modal power for the second mode to increase in the inner core-half and to decrease in the outer core-half of the waveguide. Interestingly, this leads to a decrease in effective index of the second mode due to bending at sufficiently high V-values. C1 INDIAN INST TECHNOL, DEPT PHYS, NEW DELHI 110016, INDIA. RP NATL INST STAND & TECHNOL ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. NR 15 TC 15 Z9 16 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0733-8724 EI 1558-2213 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD APR PY 1994 VL 12 IS 4 BP 621 EP 624 DI 10.1109/50.285355 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA NP299 UT WOS:A1994NP29900007 ER PT J AU BEATON, SP EVENSON, KM BROWN, JM AF BEATON, SP EVENSON, KM BROWN, JM TI ROTATIONAL SPECTROSCOPY OF THE COH RADICAL IN ITS GROUND 3-PHI STATE BY FAR-INFRARED LASER MAGNETIC-RESONANCE - DETERMINATION OF MOLECULAR-PARAMETERS SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SOLAR IDENTIFICATION; HYDRIDE; SPECTRUM; FEH AB Five rotational transitions of CoH in its ground (3) phi state have been detected by far-infrared laser magnetic resonance, three in the lowest Omega = 4 component and two in the Omega = 3 component. All the Zeeman transitions show an octet hyperfine pattern due to the Co-59 nucleus (I = 7/2). The much smaller proton doubling was also resolved for most transitions. The data have been fitted to experimental accuracy by an effective Hamiltonian for a molecule in an isolated (3) phi state. The electron orbital and spin g factors determined by the data confirm conclusively that the ground state of CoH is a (3) phi state. The accurate measurement of the rotational constant allows the equilibrium bond length to be determined: r(e)= 0.15138435(80) nm. A small Delta-type doubling was resolved in the (3) phi(3) component, suggesting the proximity of a (3) Sigma state among the low-lying electronic states. The cobalt hyperfine splittings have been fitted to determine magnetic dipole and electric quadrupole parameters, which are interpreted in terms of the dominant configuration description for the (3) phi ground state. (C) 1994 Academic Press, Inc. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. PHYS CHEM LAB,OXFORD OX1 3QZ,ENGLAND. NR 25 TC 26 Z9 26 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 APR PY 1994 VL 164 IS 2 BP 395 EP 415 DI 10.1006/jmsp.1994.1084 PG 21 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA NC819 UT WOS:A1994NC81900008 ER PT J AU YEH, LI LEE, YT HOUGEN, JT AF YEH, LI LEE, YT HOUGEN, JT TI VIBRATION-ROTATION SPECTROSCOPY OF THE HYDRATED HYDRONIUM IONS H5O2+ AND H9O4+ SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FAR INFRARED-SPECTRUM; WATER DIMER; TUNNELING SPECTRUM; MICROWAVE-SPECTRUM; HYDRAZINE; CARBODIIMIDE; DYNAMICS; HNCNH; H2O2 AB High-resolution vibration-rotation spectra in the OH antisymmetric stretching region near 3700 cm(-1) are reported for H5O2+ and H9O4+. The clusters are produced in a corona discharge ion source, cooled by supersonic expansion, mass-selected, and trapped in an RF octopole ion trap. Spectroscopic interrogation using a two-color laser scheme leads to rovibrational excitation of the trapped ions followed by preferential multiphoton dissociation of the vibrationally excited ions and detection of the resultant fragment ions. Many more lines appear in the partially resolved vibration-rotation spectrum of H5O2+ than can be explained if the molecule is rigid, and we have assumed that these additional lines arise from tunneling splittings caused by large-amplitude internal motions in this ion. Despite the low signal-to-noise ratio, all the observed spectral features can be grouped into roughly 12 R branches with a line spacing only 14% less than the B + C value calculated from the ab initio structure. Theoretically expected splitting patterns were calculated using a formalism developed earlier for tunneling motions in hydrazine, since H2N-NH2 and H2O-H+-OH2 are group-theoretically similar if the central proton of the ion is located symmetrically between the two water molecules. We tentatively conclude that the 12 branches represent the overlapping of six tunneling-split components for the in-phase and six for the out of-phase OH antisymmetric stretching vibrations expected in this region, but the low signal-to-noise ratio in the present measurements prevented unambiguous comparison of theory and experiment. (C) 1994 Academic Press, Inc. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP YEH, LI (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012 NR 45 TC 66 Z9 66 U1 0 U2 9 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1994 VL 164 IS 2 BP 473 EP 488 DI 10.1006/jmsp.1994.1090 PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA NC819 UT WOS:A1994NC81900014 ER PT J AU MATSUSHIMA, F EVENSON, KM ZINK, LR AF MATSUSHIMA, F EVENSON, KM ZINK, LR TI ABSOLUTE FREQUENCY MEASUREMENTS OF METHANOL FROM 1.5 TO 6.5 THZ SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FAR-INFRARED SPECTROSCOPY; FOURIER SPECTRUM; CM-1; CH3OH; TRANSITIONS; REGION AB Frequencies of 445 CH3OH rotational transitions between 1.5 and 6.5 THz have been measured with an accuracy of one part in 10(9). The far-infrared radiation used for the measurements was generated from the radiation of two CO2 lasers using a MIM diode as a nonlinear mixer. The high resolution and sensitivity of the spectrometer also enabled us to observe a series of forbidden Q-branch transitions (Delta n = 1 and Delta K = 0) for J = 12 to 26. (C) 1994 Academic Press, Inc. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP MATSUSHIMA, F (reprint author), TOYAMA UNIV,DEPT PHYS,GOFU KU,TOYAMA 930,JAPAN. NR 12 TC 21 Z9 22 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1994 VL 164 IS 2 BP 517 EP 530 DI 10.1006/jmsp.1994.1094 PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA NC819 UT WOS:A1994NC81900018 ER PT J AU VARBERG, TD EVENSON, KM AF VARBERG, TD EVENSON, KM TI THE PURE ROTATIONAL SPECTRA OF CUH AND CUD IN THEIR GROUND-STATES MEASURED BY TUNABLE FAR-INFRARED SPECTROSCOPY SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID TRANSFORM EMISSION-SPECTROSCOPY; COPPER AB Pure rotational transitions of CuH and CuD within the X(1) Sigma(+) (upsilon = O) state were measured over the ranges J'' = 1 to 10 for CuH and J'' = 2 to 18 for CuD, including both the (CU)-C-63 and Cu-65 isotopes. The rotational parameters B-0,B- D-0, H-0, and L(0) were separately determined for each of the four isotopomers by least-squares fitting to the observed transitions. For (CUH)-C-65, (CUD)-C-63, and (CUD)-C-65, these parameters are about two orders of magnitude more accurate than those determined by previous workers. Accurate calculated frequencies of all four isotopomers which will be useful in astronomical studies of CuH and CuD are given. (C) 1994 Academic Press, Inc. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. NR 12 TC 4 Z9 4 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1994 VL 164 IS 2 BP 531 EP 535 DI 10.1006/jmsp.1994.1095 PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA NC819 UT WOS:A1994NC81900019 ER PT J AU JUNTTILA, ML LAFFERTY, WJ BURKHOLDER, JB AF JUNTTILA, ML LAFFERTY, WJ BURKHOLDER, JB TI THE HIGH-RESOLUTION SPECTRUM OF THE NU(1) BAND AND GROUND-STATE ROTATIONAL-CONSTANTS OF HOCL SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Note ID HYPOCHLOROUS ACID C1 NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. NOAA,AERON LAB,BOULDER,CO 80303. RI Burkholder, James/H-4914-2013 NR 10 TC 34 Z9 34 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1994 VL 164 IS 2 BP 583 EP 585 DI 10.1006/jmsp.1994.1102 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA NC819 UT WOS:A1994NC81900026 ER PT J AU OVERLAND, JE SPILLANE, MC HURLBURT, HE WALLCRAFT, AJ AF OVERLAND, JE SPILLANE, MC HURLBURT, HE WALLCRAFT, AJ TI A NUMERICAL STUDY OF THE CIRCULATION OF THE BERING SEA BASIN AND EXCHANGE WITH THE NORTH PACIFIC-OCEAN SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ALASKAN STREAM; CURRENT SYSTEM; VARIABILITY; MODEL; SLOPE; EDDY AB A limited-area, primitive equation, three-layer hydrodynamic model, with realistic coastlines and bathymetry and 1/8-degrees resolution, is used to investigate the circulation of the Bering Sea basin and the adjacent North Pacific Ocean. The westward flowing Alaskan Stream to the south of the Aleutian Island chain is specified as a boundary condition at inflow and outflow ports with a constant throughput of 15 Sv (Sv = 1 X 10(6), m3 s-1). Atmospheric forcing is based on the Hellerrman and Rosenstein monthly climatological wind field. The model is spun up over 50 years and the statistics of the final decade are described. The general features of the model circulation as discussed below are consistent with available hydrographic and buoy drift observations. The model Alaskan Stream separates from the Aleutian Island chain near 175-degrees-E; beyond this point there is strong interannual variability associated with meandering and occasional eddy shedding along the northern arm of the western subarctic gyre. There is a generally cyclonic, but spatially complex and nonstationary, circulation within the Bering Sea basin, fed by inflow through the Aleutian passes; outflow is confined to Kamchatka Strait and varies seasonally, between 8.5 Sv in summer and 13 Sv in winter. A region of intense eddy activity lies west-northwest of Bowers Ridge. The model predicts seasonal reversals in the Bering slope current that are not clearly evident in the temporally sparse observational database. The numerical study demonstrates that flow instabilities contribute to substantial interannual variability in the circulation of the Bering Sea and adjacent northwest Pacific Ocean. C1 UNIV WASHINGTON,JOINT INST STUDY ATMOSPHERE & OCEAN,SEATTLE,WA 98195. USN,RES LAB,BAY ST LOUIS,MS. PLANNING SYST INC,SLIDELL,LA. RP OVERLAND, JE (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,BIN C15700,BLDG 3,SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Spillane, Michael/I-7870-2015 OI Spillane, Michael/0000-0003-0794-5675 NR 40 TC 41 Z9 45 U1 0 U2 4 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 APR PY 1994 VL 24 IS 4 BP 736 EP 758 DI 10.1175/1520-0485(1994)024<0736:ANSOTC>2.0.CO;2 PG 23 WC Oceanography SC Oceanography GA NG407 UT WOS:A1994NG40700002 ER PT J AU EZER, T MELLOR, GL AF EZER, T MELLOR, GL TI CONTINUOUS ASSIMILATION OF GEOSAT ALTIMETER DATA INTO A 3-DIMENSIONAL PRIMITIVE EQUATION GULF-STREAM MODEL SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID THERMAL-ANALYSIS SYSTEM; HUDSON-RARITAN ESTUARY; GENERAL-CIRCULATION; DELAWARE BAY; RIVER SYSTEM; OCEAN MODELS; INTERPOLATION; SIMULATION; ATLANTIC; REGION AB A three-dimensional data assimilation scheme is described and tested, using the Geosat altimeter data and a high-resolution, primitive equation, numerical ocean model of the Gulf Stream region. The assimilation scheme is based on an optimal interpolation approach in which data along satellite tracks are continuously interpolated horizontally and vertically into the model grid and assimilated with the model prognostic fields. Preprocessed correlations between surface elevation anomalies and subsurface temperature and salinity anomalies are used to project surface information into the deep ocean; model and data error estimates are used to optimize the assimilation. Analysis fields derived from the Navy's Optimum Thermal Interpolation System are used to initialize the model and to provide some estimate of errors. To evaluate the effectiveness of the assimilation scheme, the errors of model oceanic fields (surface elevation, Gulf Stream axis, temperature) with data assimilation are compared with errors without data assimilation (i.e., a pure forecast). Although some mesoscale meanders and rings are not well produced by the assimilation model, consistent reduction of errors by the assimilation is demonstrated. The vertical distribution of errors reveals that the scheme is most effective in nowcasting temperatures at middepth (around 500 m) and less effective near the surface and in the deep ocean. The scheme is also more effective in nowcasting the Gulf Stream axis location than in nowcasting temperature variations. A comparison of the assimilation scheme during two periods shows that the nowcast skill of the assimilated model is reduced in May-September 1988, compared to May-July 1987, due to poor coverage of the altimeter data during 1988. This paper is one step toward a dynamic model and data assimilation system, which when fully developed, should provide useful nowcast and forecast information. RP EZER, T (reprint author), PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,SAYRE HALL,POB CN710,PRINCETON,NJ 08544, USA. OI Ezer, Tal/0000-0002-2018-6071 NR 39 TC 73 Z9 80 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD APR PY 1994 VL 24 IS 4 BP 832 EP 847 DI 10.1175/1520-0485(1994)024<0832:CAOGAD>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA NG407 UT WOS:A1994NG40700007 ER PT J AU STABENO, PJ REED, RK AF STABENO, PJ REED, RK TI CIRCULATION IN THE BERING SEA BASIN OBSERVED BY SATELLITE-TRACKED DRIFTERS - 1986-1993 SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Note ID CURRENT SYSTEM; VARIABILITY; PACIFIC; SLOPE; FLOW AB From 1986 through April 1993, 86 satellite-tracked buoys were deployed in the North Pacific and Bering Sea. Most of the buoys were drogued at 40 m. A composite current pattern is derived using these data. The two principal currents (the Alaskan Stream and Kamchatka Current) are clearly evident. Eddy kinetic-mean kinetic energy ratios are low in the stream and along the western Bering Sea basin. An eastward flowing current occurred along the north flank of the Aleutian Islands; this flow was modified by inflow at the passes. Westward flow occurred north of 56-degrees-N; its source was the Bering Slope Current. The Kamchatka Current originated near 175-degrees-E along the Russian coast. Numerous eddies and meanders were observed in the Kamchatka Current; eddies were also present on the eastern side of the basin. RP STABENO, PJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,NOAA BLDG 3,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 23 TC 81 Z9 87 U1 1 U2 7 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 APR PY 1994 VL 24 IS 4 BP 848 EP 854 DI 10.1175/1520-0485(1994)024<0848:CITBSB>2.0.CO;2 PG 7 WC Oceanography SC Oceanography GA NG407 UT WOS:A1994NG40700008 ER PT J AU GUINN, VP GAVRILASGUINN, M DEMIRALP, R AF GUINN, VP GAVRILASGUINN, M DEMIRALP, R TI MEASUREMENT OF ARSENIC IN SECTIONED HAIR SAMPLES BY INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article AB In a recent Texas murder case, bundles of head hair from the female victim (aligned with all root ends together) were washed, cut into 7 mm sections, air-dried and weighed, activated in a nuclear reactor neutron flux, and then counted with a Ge(Li) detector/4096-channel gamma-ray spectrometer. In each of the 15 samples, the 559 keV gamma-ray peak of 26.3 hour As-76 was measured. In the section closest to the scalp, an arsenic concentration of 107 ppm was found (cf. a ''normal'' level of about 1 ppm As). Barium ingestion was also possible so Ba was looked for, but not found. The victim's husband was found guilty of murder by chronic arsenic poisoning. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP GUINN, VP (reprint author), UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLL PK,MD 20742, USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD APR PY 1994 VL 179 IS 2 BP 365 EP 368 DI 10.1007/BF02040172 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA NP721 UT WOS:A1994NP72100021 ER PT J AU NATALISORA, I WONGNG, W HUANG, Q ROTH, RS RAWN, CJ BURTON, BP SANTORO, A AF NATALISORA, I WONGNG, W HUANG, Q ROTH, RS RAWN, CJ BURTON, BP SANTORO, A TI X-RAY AND NEUTRON-DIFFRACTION STUDY OF CABI2O4 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID BOND-VALENCE PARAMETERS; BI2O3-CAO; SYSTEM AB The crystal structure of the 1:1 CaO-Bi2O3 compound (CaBi2O4) has been determined by single crystal X-ray and neutron powder diffraction techniques. The compound crystallizes with the symmetry of the monoclinic space group C2/c and lattice parameters a = 16.6130(5) angstrom, b = 11.5900(4) angstrom, c = 13.9939(4) angstrom, beta = 134.048(1)-degrees. The structure consists of sheets parallel to the b-c plane and connected by Ca-O bonds. There is a structural unit in each layer consisting of four Bi atoms, ten oxygen atoms, and two calcium atoms. The Bi atoms are fourfold coordinated and the coordination polyhedron may be described as a short distorted pyramid, open on one end to accommodate the lone-pair electrons of the bismuth atoms. Calcium is seven-coordinated and the coordination polyhedron may be described as a monocapped trigonal prism. (C) 1994 Academic Press, Inc. RP NATALISORA, I (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Natali Sora, Isabella/C-8357-2011 NR 12 TC 15 Z9 15 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD APR PY 1994 VL 109 IS 2 BP 251 EP 258 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA NG892 UT WOS:A1994NG89200007 ER PT J AU ZUTSHI, A HABER, RA NIESZ, DE ADAMS, JW WACHTMAN, JB FERBER, MK HSU, SM AF ZUTSHI, A HABER, RA NIESZ, DE ADAMS, JW WACHTMAN, JB FERBER, MK HSU, SM TI PROCESSING, MICROSTRUCTURE, AND WEAR BEHAVIOR OF SILICON-NITRIDE HOT-PRESSED WITH ALUMINA AND YTTRIA SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE ENERGY; STRENGTH; SI3N4; TOUGHNESS; MECHANISM; WATER AB Commercial silicon nitride powder with Al2O3 and Y2O3 additives was hot-pressed to complete density. The resulting microstructure contained elongated grains with no trace of remaining alpha-Si3N4. The aspect ratio of the elongated grains increased with increasing soak time at a fixed hot-pressing temperature. X-ray diffraction analysis showed that the crystalline phase in the hot-pressed samples was beta-sialon (Si6-zAlzOzN8-z) with z values that increased with soak time. The fracture strength and fracture toughness of the samples increased as the aspect ratio of the grains increased. The Vickers hardness decreased slightly as the soak time was increased, which was attributed to a grain size effect. Wear tests of silicon nitride against silicon nitride were conducted on a reciprocating pin-on-disk apparatus with paraffin oil as a lubricant. Correlation studies of wear with microstructure and mechanical properties were performed. The wear rate increased rapidly with increasing soak time in spite of the increased strength and toughness. This was attributed to increased third-body wear caused by pullout of pieces from the wear surface. The pullout mechanism was not conclusively identified. However, TEM examination showed clear evidence of dislocation motion under the wear scar. Grain boundary microstresses caused by the anisotropic thermal expansion and elastic properties of the elongated grains may have contributed to the observed pullout. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP ZUTSHI, A (reprint author), RUTGERS UNIV STATE,CTR CERAM RES,PISCATAWAY,NJ 08855, USA. NR 47 TC 36 Z9 37 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 APR PY 1994 VL 77 IS 4 BP 883 EP 890 DI 10.1111/j.1151-2916.1994.tb07243.x PG 8 WC Materials Science, Ceramics SC Materials Science GA NG916 UT WOS:A1994NG91600003 ER PT J AU CHEN, W PECHENIK, A DAPKUNAS, SJ PIERMARINI, GJ MALGHAN, SG AF CHEN, W PECHENIK, A DAPKUNAS, SJ PIERMARINI, GJ MALGHAN, SG TI NOVEL EQUIPMENT FOR THE STUDY OF THE COMPACTION OF FINE POWDERS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB This paper describes a highly specialized system for studies of time-dependent compaction of nano-size and other fine-size powders under a variety of atmospheres and at temperatures ranging from 77 to 1000 K. The system incorporates a 10000 kg screw-driven press with a piston-cylinder type of die and can produce cylindrical powder compacts, 3mm in diameter and of various thicknesses, utilizing pressures up to 3 GPa. The system is computer-controlled and permits measurements of the sample volume with an uncertainty of 0.07mm3 and, after appropriate calibration, can determine the rate and degree of densification of the compacting powder as pressure is applied. To illustrate its capabilities, the system was used to study the densification of several powders, including nano-size gamma-Al2O3, submicrometer 95% alpha-Si3N4, RbBr, and KCl. The results obtained on RbBr and KCl, used for calibration and testing of the equipment, are in good agreement with previously published data for these materials. RP CHEN, W (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 14 TC 17 Z9 17 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 1994 VL 77 IS 4 BP 1005 EP 1010 DI 10.1111/j.1151-2916.1994.tb07259.x PG 6 WC Materials Science, Ceramics SC Materials Science GA NG916 UT WOS:A1994NG91600019 ER PT J AU STEIN, SE AF STEIN, SE TI ESTIMATING PROBABILITIES OF CORRECT IDENTIFICATION FROM RESULTS OF MASS-SPECTRAL LIBRARY SEARCHES SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID MATCHING SYSTEM; PREDICTION; RETRIEVAL AB This work presents a method for using mass spectral match factors reported by library search systems to obtain certain probabilistic indicators of correct identification. The overall probability that a retrieval is correct is formally separated into two independent terms. One of these is the probability that a retrieval is correct assuming that the correct match is contained in the library. This can be computed directly from test results. The other term represents the probability that the spectrum of the unknown compound is actually in the library. While the absolute value of this term cannot be computed, a relative value based solely on search results can be derived. This value may, if desired, be used to refine an initial estimate of the overall probability. Parameters used in this calculation are based on changes in test results caused by the logical removal of the test compounds from the library. These methods were parameterized from results of searching the NIST/EPA/NIH Mass Spectral Database with 12,592 good quality replicate spectra and a simple mass spectral comparison function. The methodology should be equally applicable to other libraries and search systems. RP STEIN, SE (reprint author), NATL INST STAND & TECHNOL,NIST MASS SPECT DATA CTR,GAITHERSBURG,MD, USA. NR 19 TC 87 Z9 87 U1 2 U2 16 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 APR PY 1994 VL 5 IS 4 BP 316 EP 323 DI 10.1016/1044-0305(94)85022-4 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA NF015 UT WOS:A1994NF01500012 PM 24222569 ER PT J AU XU, Q AF XU, Q TI SEMIBALANCE MODEL - CONNECTION BETWEEN GEOSTROPHIC-TYPE AND BALANCED-TYPE INTERMEDIATE MODELS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID BAROTROPIC CONTINENTAL-SHELF; SLOPE FLOW-FIELDS; BAROCLINIC INSTABILITY; MOMENTUM APPROXIMATION; FRONTAL CIRCULATIONS; PERIODIC DOMAINS; Q-VECTOR; EQUATIONS; FORMULATION; STABILITY AB A hybrid intermediate model, called the semibalance model, is derived from a single truncation of the vector vorticity equation with a balanced vorticity approximation that neglects the advection and stretching-tilting of the unbalanced secondary flow vorticity. This approximation applies not only to straight fronts, like the semi-geostrophy (SG), but also to highly curved fronts and vortices in which the balanced leading-order velocity and unbalanced secondary vorticity are nearly parallel with slow spatial variations along the front or vortex flow. The semibalance model is similar to the balance equations based on momentum equations (BEM) except that the leading-order flow is nonlinearly balanced and the secondary circulation is not free of vertical vorticity. As in BEM, the truncated potential vorticity in the semibalance model is more accurate than in SG, and the problem with spurious high-frequency oscillation in BEM is eliminated in the semibalance model. The potential vorticity in the semibalance model is not only conserved but also ''invertible,'' so the semibalance dynamics can be examined through ''potential vorticity thinking.'' In this sense, the semibalance model combines the advantages of SG and BEM. Diagnostic equations for the secondary circulation are derived. The associated boundary value problem is shown to be well posed in iterative form, provided the leading-order potential vorticity is positive and, thus, the flow is inertially and convectively stable. Methods for the numerical solution of the semibalance model are presented. Under more restrictive conditions, the semibalance model reduces to the quasi-balance and bilinear quasi-balance models. Through the semibalance and quasi-balance models, the geostrophic-type and balanced-type models are connected. RP XU, Q (reprint author), UNIV OKLAHOMA,NOAA,CIMMS,ROOM 1110,100 E BOYD,NORMAN,OK 73019, USA. NR 39 TC 15 Z9 19 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 1 PY 1994 VL 51 IS 7 BP 953 EP 970 DI 10.1175/1520-0469(1994)051<0953:SMBGTA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NF987 UT WOS:A1994NF98700003 ER PT J AU STAFFORD, GR AF STAFFORD, GR TI THE ELECTRODEPOSITION OF AL3TI FROM CHLOROALUMINATE ELECTROLYTES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SODIUM CHLORIDE BATH; AL-MN ALLOYS; MOLTEN-SALTS; ALUMINUM; NUCLEATION; TITANIUM; PHASE; MICROSTRUCTURES; TRIALUMINIDES; DEFORMATION AB The electrochemistry of Ti(II) in 2:1 AlCl3:NaCl and the electrodeposition of metastable aluminum-titanium alloys containing up to 28 atom percent Ti are reported. Ti(II)/Ti(III) was studied by chronoamperometry, chronopotentiometry, cyclic voltammetry, and convolution voltammetry during the electrochemical dissolution of titanium. It was concluded that Ti(II)/Ti(III) behaves reversibly in this electrolyte and that, at low current densities, titanium dissolves to form Ti(II). The dissolution follows Faraday's law for Ti(II) concentrations approaching 75 mmol/liter, though concentrations up to 325 mmol/liter can be obtained at dissolution current efficiencies less than 100%. Single-phase Al3Ti with the ordered face-centered cubic L1(2) structure is deposited under conditions where the Ti partial current is not diffusion limited. Current transients and microscopic analysis of the early stages of potentiostatic deposition suggest that Al3Ti forms by instantaneous three-dimensional nucleation at potentials where the growth process is under mixed kinetic and diffusion control. RP STAFFORD, GR (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 45 TC 31 Z9 34 U1 1 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 APR PY 1994 VL 141 IS 4 BP 945 EP 953 DI 10.1149/1.2054863 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA NF410 UT WOS:A1994NF41000024 ER PT J AU BRUNO, TJ AF BRUNO, TJ TI MEASUREMENT OF DIFFUSION IN FLUID SYSTEMS - APPLICATIONS TO THE SUPERCRITICAL-FLUID REGION SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID CHROMATOGRAPHY SFC; CARBON-DIOXIDE; COEFFICIENTS; CO2; NAPHTHALENE; CAFFEINE; BENZENE AB In this article, the experimental procedures that are applicable to the measurement of diffusion in supercritical fluid solutions will be reviewed. This topic is of great importance to the proper design of advanced aircraft and turbine fuels, since the fuels on these aircraft may sometimes operate under supercritical fluid conditions. More specifically, we will consider measurements of the binary interaction diffusion coefficient D12 of a solute (species 1) and the solvent (species 2). In this discussion the supercritical fluid will be species 2, and the solute, species 1, will be at a relatively low concentration, sometimes approaching infinite dilution. After a brief introduction to the concept of diffusion, we will discuss in detail the use of chromatographic methods, and then briefly treat light scattering, nuclear magnetic resonance spectra, and physical methods. RP BRUNO, TJ (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 28 TC 5 Z9 5 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD APR-JUN PY 1994 VL 8 IS 2 BP 329 EP 333 DI 10.2514/3.542 PG 5 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA NG696 UT WOS:A1994NG69600020 ER PT J AU SUNDA, WG HUNTSMAN, SA AF SUNDA, WG HUNTSMAN, SA TI PHOTOREDUCTION OF MANGANESE OXIDES IN SEAWATER SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 12th International Symposium on Chemistry of the Mediterranean CY MAY 18-23, 1992 CL ROVINJ, CROATIA ID NATURAL-WATERS; OXIDATION RATE; SUNLIGHT; BACTERIA; MN(II); DISSOLUTION; REDUCTION; DIOXIDE; ESTUARY; COPPER AB Experiments were conducted on the photoreductive dissolution of Mn-54-labeled synthetic oxides, prepared from MnO4(2-) oxidation of Mn-54-(II), and natural labeled oxides formed in seawater from microbial oxidation of Mn-54-(II). Sunlight increased the dissolution rate of synthetic oxides in seawater, and effect that increased with the duration of light exposure. The photodissolution of these oxides was found to result primarily from Mn reduction by H2O2, produced in seawater from the photoreduction of O2 by dissovled organic matter. This conclusion was based on the previously observed marked stimulation of photodissolution by added humic compounds, the observed reductive dissolution of the oxides by added H2O2 and on the almost complete reversal of photodissolution by enzymatic (catalase) removal of H2O2. Sunlight had an even larger stimulatory effect on the reductive dissolution Mn-54-labeled natural oxides. It increased specific dissolution rates to values of 6-13% h-1, 6-70 times higher than rates in the dark. In contrast to synthetic oxides, rates for natural oxides did not increase measurably with the duration of light exposure, were not appreciably altered by humic acid addition or by photolytic removal of natural organic matter, and were not substantially reduced by catalase addition. Furthermore, rates for the reductive dissolution of natural oxides by H2O2 were only about 1/6th of those for synthetic oxides. These results indicate that the photoreductive dissolution of natural oxides in seawater is not primarily related to the photoproduction of H2O2, although such production appears to account for a small portion (ca. 10-20%) of the overall effect. Instead, both the chromophore and the reductant(s) involved in the reaction appear to reside with the bacterial/Mn oxide aggregates themselves. Although several possibilities can be postulated, the exact mechanism of the photochemical reaction remains obscure. RP SUNDA, WG (reprint author), NOAA,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 25 TC 73 Z9 76 U1 3 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD APR PY 1994 VL 46 IS 1-2 BP 133 EP 152 DI 10.1016/0304-4203(94)90051-5 PG 20 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA NF585 UT WOS:A1994NF58500012 ER PT J AU BOEHLERT, GW MUNDY, BC AF BOEHLERT, GW MUNDY, BC TI VERTICAL AND ONSHORE-OFFSHORE DISTRIBUTIONAL PATTERNS OF TUNA LARVAE IN RELATION TO PHYSICAL HABITAT FEATURES SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE SCOMBRIDAE; LARVAL ECOLOGY; SPAWNING; ISLANDS; HAWAII ID BLUEFIN THUNNUS-MACCOYII; SEA-SURFACE TEMPERATURES; SOUTHERN BLUEFIN; INDIAN-OCEAN; KATSUWONUS-PELAMIS; TROPICAL PACIFIC; HAWAIIAN-ISLANDS; YELLOWFIN TUNA; SKIPJACK TUNA; SCOMBRIDAE AB The seasonal and spatial distributions of larval scombrids in Waters off Oahu, Hawaii, were studied in September and December 1985 and April and June 1986 to determine vertical and onshore-offshore patterns. Horizontal distribution was resolved by sampling transects of 3 stations on the windward (east; 3.7, 9.3, and 27.8 km offshore) and leeward (west; 1.8, 9.3, and 27.8 km offshore) sides of the island. Vertical distribution was resolved by sampling with MOCNESS and Manta nets in 8 depth strata (0 to 80 m) at the 2 nearshore stations and 9 depth strata (0 to 200 m) at the 4 offshore stations. Scombrid larvae were abundant in all months except December. Collections in September and June were dominated by Thunnus spp.; about half were large enough to be identified to species and were predominantly T. albacares. Thunnus spp. generally were most abundant closest to shore on the leeward side of the island. Larval Thunnus were not taken at > 60 m, were most abundant in the upper 20 m, and were captured in the neuston at night but rarely in daytime. The other 2 dominant larval scombrids, Katsuwonus pelamis and Auxis spp., were most abundant in slightly deeper water. K. pelamis were most abundant at offshore stations, but Auxis spp. showed no clear onshore-offshore pattern. In April, Auxis spp. were most abundant and comprised over 99% of all larval scombrids. Diel vertical distribution patterns were not consistent between cruises or sides of the island for any species studied. No evidence was found for diel Migratory behavior. The physical structure of the water column, particularly temperature and salinity, altered the spatial and temporal distribution patterns of larvae on short time and space scales and also on the seasonal Scale. Seasonal patterns of spawning were likely dependent upon availability of appropriate thermal habitat. Larval Thunnus spp. and K. pelamis, in particular, were abundant only when temperatures were relatively warm. Auxis spp. larvae were found over a wider range of temperature than were the other genera. We suggest that the high concentrations of scombrid larvae, particularly Thunnus spp., near islands may be related to habitat characteristics that promote higher larval survival than in oceanic waters. C1 NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, HONOLULU LAB, HONOLULU, HI 96822 USA. UNIV HAWAII, JOINT INST MARINE & ATMOSPHER RES, HONOLULU, HI 96822 USA. NR 60 TC 54 Z9 55 U1 0 U2 8 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 APR PY 1994 VL 107 IS 1-2 BP 1 EP 13 DI 10.3354/meps107001 PG 13 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA NH216 UT WOS:A1994NH21600001 ER PT J AU KRISHNAKUMAR, PK CASILLAS, E VARANASI, U AF KRISHNAKUMAR, PK CASILLAS, E VARANASI, U TI EFFECT OF ENVIRONMENTAL CONTAMINANTS ON THE HEALTH OF MYTILUS-EDULIS FROM PUGET-SOUND, WASHINGTON, USA .1. CYTOCHEMICAL MEASURES OF LYSOSOMAL RESPONSES IN THE DIGESTIVE CELLS USING AUTOMATIC IMAGE-ANALYSIS SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE MUSSELS; LYSOSOMAL RESPONSES; GROWTH; CONTAMINANTS; IMAGE ANALYSIS ID QUANTITATIVE CYTO-CHEMISTRY; PHYSIOLOGICAL ENERGETICS; AROMATIC-HYDROCARBONS; LITTORINA-LITTOREA; BIVALVE MOLLUSKS; ARCA-ZEBRA; MUSSEL; PHENANTHRENE; OIL; ACCUMULATION AB Lysosomal responses in the digestive cells of Mytilus edulis from 9 sites in Puget Sound, Washington, USA, with varying degrees of sediment contamination were measured using automatic image analysis. Mussels from urban-associated sites (areas with elevated sediment concentration of anthropogenic contaminants such as PAHs, PCBs, DDTs, and toxic elements) showed pathological changes in the lysosomes (reduced lysosomal labilization period, reduced lysosomal stability and increased N-acetyl beta-hexosaminidase activity), enhanced lipofuscin deposition and increased accumulation of lysosomal and cytoplasmic unsaturated neutral lipids. Morphometric measures of growth showed that mussels were generally smaller in size and that somatic tissue weight relative to shell length was lower in mussels from urban-associated sites relative to those from minimally contaminated sites. Highly significant correlations were observed between concentrations of tissue PAH, PCB, and selected toxic elements (measures of anthropogenic exposure) and lysosomal labilization period. Pathological alterations in the lysosomal system of mussels from the urban-associated sites were probably induced by the high tissue concentrations of organic and inorganic contaminants rather than as a result of potential confounding biotic (spawning stress) or abiotic (temperature, salinity and food availability) factors. The results show that cytochemical measurement of lysosomal responses combined with automatic image analysis have the potential to be used as sensitive, accurate and rapid techniques for assessing the biological impact of environmental contaminants in mussels in the near coastal environment. C1 NOAA, NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR, DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E, SEATTLE, WA 98112 USA. CENT MARINE FISHERIES INST, COCHIN 682031, KERALA, INDIA. NR 59 TC 101 Z9 106 U1 3 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 APR PY 1994 VL 106 IS 3 BP 249 EP 261 DI 10.3354/meps106249 PG 13 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA NE201 UT WOS:A1994NE20100004 ER PT J AU BAKER, JD FOWLER, CW ANTONELIS, GA AF BAKER, JD FOWLER, CW ANTONELIS, GA TI BODY-WEIGHT AND GROWTH OF JUVENILE MALE NORTHERN FUR SEALS, CALLORHINUS-URSINUS SO MARINE MAMMAL SCIENCE LA English DT Article DE NORTHERN FUR SEALS; CALLORHINUS-URSINUS; BODY WEIGHT; GROWTH, SURVIVAL ID ARCTOCEPHALUS-GAZELLA AB To mark-recapture study conducted in 1987-1992 provided weight measurements of juvenile male northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska, at ages ranging from approximately 1. 5 mo to 5 yr. Males born in 1987 tended to weigh less at ages 3 and 4 yr than those born in other years. Weights of individuals at ages 2, 3, and 4 yr were significantly correlated with their weights as pups (P < 0.05). Weights at ages 2 and 3, 3 and 4, and 4 and 5 yr were significantly correlated (P < 0.001), although weight changes with age were highly variable. Data indicate that larger than average male pups born during 1987-1990 were more likely to survive, but this effect was less evident than among pups born during 1960-1965 when average pup weights were lower. RP BAKER, JD (reprint author), NOAA,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,7600 SAND POINT,SEATTLE,WA 98115, USA. NR 23 TC 11 Z9 11 U1 1 U2 5 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 1994 VL 10 IS 2 BP 151 EP 162 DI 10.1111/j.1748-7692.1994.tb00257.x PG 12 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA NL734 UT WOS:A1994NL73400002 ER PT J AU HARVEY, JT ANTONELIS, GA AF HARVEY, JT ANTONELIS, GA TI BIASES ASSOCIATED WITH NONLETHAL METHODS OF DETERMINING THE DIET OF NORTHERN ELEPHANT SEALS SO MARINE MAMMAL SCIENCE LA English DT Article ID FEEDING-HABITS; PHOCA-VITULINA; OTOLITHS; CONSUMPTION C1 NOAA,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. NR 15 TC 38 Z9 39 U1 0 U2 6 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 1994 VL 10 IS 2 BP 178 EP 187 DI 10.1111/j.1748-7692.1994.tb00259.x PG 10 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA NL734 UT WOS:A1994NL73400004 ER PT J AU SINCLAIR, EH AF SINCLAIR, EH TI PREY OF JUVENILE NORTHERN ELEPHANT SEALS (MIROUNGA-ANGUSTIROSTRIS) IN THE SOUTHERN CALIFORNIA BIGHT SO MARINE MAMMAL SCIENCE LA English DT Note ID FEEDING-HABITS RP SINCLAIR, EH (reprint author), ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 45 TC 9 Z9 11 U1 0 U2 0 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 1994 VL 10 IS 2 BP 230 EP 239 DI 10.1111/j.1748-7692.1994.tb00267.x PG 10 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA NL734 UT WOS:A1994NL73400012 ER PT J AU WEISS, MA WEISSERT, TP AF WEISS, MA WEISSERT, TP TI SIFTING THROUGH 9 YEARS OF NIST CLOCK DATA WITH TA2 SO METROLOGIA LA English DT Article ID TIME SCALE ALGORITHM; PRECISION FREQUENCY SOURCES; ATOMIC CLOCKS; VARIANCE; MODELS AB We have extended the new TA2 post-processed time scale at the NIST beyond our previous reports to include all of the period from January 1984 to December 1992. Derived from the ensemble of clocks at the NIST, this time scale includes the benefits of several recent refinements to the algorithm. By iteratively running the algorithm on the ensemble clock data and characterizing anomalous behaviour in the dominant individual clocks of the ensemble between iterations, we obtain an optimized scale which benefits from the informed anticipation of that anomalous behaviour and demonstrates an overall decrease in scale disruption. Herein we discuss changes to the TA2 algorithm that we made while processing the eight-year run, our method of characterizing anomalous behaviour in individual clocks, the way unanticipated anomalous behaviour is dealt with by the algorithm, and our resulting nine-year time scale. C1 ST JOSEPHS UNIV,DEPT PHYS,PHILADELPHIA,PA 19131. RP WEISS, MA (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 29 TC 3 Z9 3 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD APR PY 1994 VL 31 IS 1 BP 9 EP 19 DI 10.1088/0026-1394/31/1/003 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV371 UT WOS:A1994NV37100002 ER PT J AU TILFORD, CR AF TILFORD, CR TI 3 AND A HALF CENTURIES LATER - THE MODERN-ART OF LIQUID-COLUMN MANOMETRY SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS ID ULTRASONIC INTERFEROMETER; MERCURY; DENSITY AB After three and a half centuries the Torricellian mercury manometer remains the most accurate pressure standard. State-of-the-art manometers achieve parts-per-million total uncertainties near atmospheric pressures and imprecisions as low as 0,01 Pa. The total uncertainty is determined primarily by uncertainties in the measurement of the height of the mercury surfaces and the average mercury density. The latter is limited generally by the uncertainty of the average temperature of the mercury. The techniques used to locate the mercury surfaces and determine their heights not only determine the imprecision and accuracy of the height measurement, but can also have a significant effect on the maintenance of a stable and uniform mercury temperature. This review discusses the factors important in high-accuracy manometers with particular emphasis on surface detection and height measurement techniques. Specifically discussed are capacitance detection, white-light fringes, optical interferometry, with and without floats, and ultrasonic measurements. RP TILFORD, CR (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 37 TC 5 Z9 5 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 APR PY 1994 VL 30 IS 6 BP 545 EP 552 DI 10.1088/0026-1394/30/6/001 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000002 ER PT J AU EHRLICH, C AF EHRLICH, C TI A REVIEW OF GAS-OPERATED PISTON GAUGES SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS ID PRESSURE MEASUREMENT; 5 MPA; RANGE AB While hydraulic piston gauge technology dates from the mid-1800s, the first practical gas-lubricated pneumatic piston gauges for metrological applications were not developed until almost one hundred years later. The major reason for this delay was the need for adequate materials and machining technology to fabricate pistons and cylinders with tight enough tolerances for acceptable instrument operation. As the need for reduced uncertainties increased for gas pressure measurements in the ranges covered by manometry and above, technological improvement in gas-operated piston gauges advanced rapidly. Requirements for the development of high-quality air bearings added stimulus to the push for improved piston and cylinder technology. Investigations into the possible use of pneumatic piston gauges as primary pressure standards competitive with manometry had begun by 1965. Although lack of a fundamental detailed model of the vertical momentum transfer from the moving gas to the flanks of the piston currently somewhat limits this application, improvements in understanding and technology are continually being made. The relatively recent discoveries of the sometimes significant dependence of the effective area of certain pneumatic piston gauges on the gas species used during operation, or on whether the gauge is operating in the gauge or absolute mode, underscore the need for continued research in this field. RP EHRLICH, C (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 50 TC 1 Z9 1 U1 0 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD APR PY 1994 VL 30 IS 6 BP 585 EP 590 DI 10.1088/0026-1394/30/6/007 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000008 ER PT J AU MEYER, CW REILLY, ML AF MEYER, CW REILLY, ML TI MEASUREMENTS OF THE GAS DEPENDENCE OF THE EFFECTIVE AREA OF A PISTON GAUGE USING H2, HE-3, HE-4, N2, CO2 AND SF6 SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS ID MODE AB Measurements have been performed to investigate the gas dependence of the absolute mode effective area A(eff) of a piston gauge. The gases studied were H-2, He-3, He-4, N2, CO2 and SF6. The data obtained were used to determine DELTAA(eff) = A(eff)(gas) - A(eff)(N2) in the pressure range 1,4 kPa to 103 kPa for He-3 and 1,4 kPa to 162 kPa for H-2, He-4, CO2 and SF6. Above 1,4 kPa, the uncertainty in DELTAA(eff) was less-than-or-equal-to 2 parts per million. The measurements yielded effective area differences ranging from 26 ppm at 1,4 kPa to 4 ppm at 45 kPa; from 100 kPa to 162 kPa, the maximum difference, to within the resolution of the measurements, was constant at 6 ppm to 7 ppm. RP MEYER, CW (reprint author), NATL INST STAND & TECHNOL,DIV PROC MEASUREMENTS,GAITHERSBURG,MD 20899, USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD APR PY 1994 VL 30 IS 6 BP 595 EP 597 DI 10.1088/0026-1394/30/6/009 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000010 ER PT J AU SCHMIDT, JW WELCH, BE EHRLICH, CD AF SCHMIDT, JW WELCH, BE EHRLICH, CD TI GAS AND MODE, VERTICAL AND ROTATIONAL EFFECTS WITH A 3 PISTON GAUGE APPARATUS SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS ID PRESSURE AB A semi-automated three piston gauge apparatus has been used to measure gas species and mode effects in a low pressure pneumatic dead-weight piston gauge. Two gases, He and N2, were used in both gauge and absolute modes, as well as several ''intermediate'' modes, to characterize a single gauge. The results of the measurements are compared with a model for crevice effects that incorporates both molecular and viscous flow regimes. The model has previously been applied to spin decay rate measurements on the four gases He, N2, H-2 and SF6, and has now been extended to account for differences in effective area arising from species changes. Mode effects remain that cannot be predicted by the model. RP SCHMIDT, JW (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 8 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 APR PY 1994 VL 30 IS 6 BP 599 EP 602 DI 10.1088/0026-1394/30/6/010 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000011 ER PT J AU MOLINAR, GF CRESTO, PC EHRLICH, C HOUCK, J AF MOLINAR, GF CRESTO, PC EHRLICH, C HOUCK, J TI ELASTIC DISTORTION CALCULATIONS ON A SPECIAL PISTON GAUGE (PG27) UP TO 28 MPA IN DIFFERENT OPERATIONAL MODES SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS ID PRESSURE AB The elastic distortions of a special hydraulic piston gauge (PG27) operating at up to 28 MPa in simple, reentrant and controlled-clearance configurations were calculated by an iterative analytical technique. It was possible to determine die radial displacements of the piston and the cylinder at any pressure, and the pressure distribution in the clearance with different fluids, and to compute the pressure distortion coefficient of die piston-cylinder unit under conditions of use. Calculations show that the elastic distortion, the pressure distribution in the clearance and the pressure distortion coefficients are not fluid-dependent, at least for two of the most commonly used fluids. In the simple configuration, the radial distortion of the piston-cylinder unit at die maximum pressure is of the same magnitude as the undistorted radial clearance (0,527 mum). Agreement between the experimental and the calculated pressure distortion coefficients is about 1,4 % and corresponds to less than 0,6 part per million difference in effective area at 28 MPa. In the re-entrant configuration, the clearance between the piston and cylinder decreases to a minimum value of 0,282 mum at 28 MPa. Agreement between the experimental and the calculated pressure distortion coefficients is within 14,3 % and corresponds to 8,0 ppm difference in effective area at 28 MPa. In the controlled-clearance configuration, the distortions of the cylinder are, on average, equal to zero, as expected with controlled-clearance piston gauges, and die pressure distribution in die clearance is die most linear of the three operating modes. Agreement between the experimental and the calculated pressure distortion coefficients corresponds to less than 11,0 ppm difference in effective area at 14 MPa and 28 MPa. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. RP MOLINAR, GF (reprint author), CNR,IST METROL G COLONNETTI,STRADA DELLE CACCE 73,I-10135 TURIN,ITALY. NR 6 TC 0 Z9 0 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 APR PY 1994 VL 30 IS 6 BP 635 EP 640 DI 10.1088/0026-1394/30/6/017 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000018 ER PT J AU MOLINAR, GF MAGHENZANI, R BEAN, VE WARD, D AF MOLINAR, GF MAGHENZANI, R BEAN, VE WARD, D TI EXPERIENCE IN THE USE OF A STRAIN-GAUGE PRESSURE TRANSDUCER FOR COMPARISON IN LIQUID-MEDIA UP TO 600 MPA BETWEEN THE NIST AND THE IMGC SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS AB Primary standard piston gauges are frequently used to perform pressure comparisons, but at other times, and particularly in the pressure range greater than 300 MPa, suitable transfer standards are used for the same purpose. The IMGC and the NIST have completed a bilateral intercomparison for gauge pressure measurements in liquid media up to 600 MPa using a strain-gauge pressure transducer as the transfer standard. The main metrological characteristics of the transducer are discussed, particularly the stability with time and the uncertainty limits for use as a transfer standard. The pressure scale between 100 MPa and 600 MPa as maintained by the two laboratories is described, and the results of the comparison are discussed in order to demonstrate the agreement in pressure measurement between the IMGC and the NIST. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP MOLINAR, GF (reprint author), CNR,IST METROL G COLONNETTI,STRADA DELLE CACCE 73,I-10135 TURIN,ITALY. NR 3 TC 0 Z9 0 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 APR PY 1994 VL 30 IS 6 BP 717 EP 720 DI 10.1088/0026-1394/30/6/034 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000035 ER PT J AU BEAN, VE AF BEAN, VE TI DYNAMIC PRESSURE METROLOGY SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS AB According to the ANSI MC88.1-1972 standard A Guide for the Dynamic Calibration of Pressure Transducers, the properties to be determined when calibrating a dynamic pressure transducer are sensitivity, amplitude as a function of frequency, phase as a function of frequency, resonant frequency, damping ratio, rise time and overshoot. A static calibration yields only the sensitivity. The properties of dynamic pressure transducers and various methods for determining them are reviewed. RP BEAN, VE (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 18 TC 11 Z9 11 U1 0 U2 3 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD APR PY 1994 VL 30 IS 6 BP 737 EP 741 DI 10.1088/0026-1394/30/6/037 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000038 ER PT J AU BEAN, VE BOWERS, WJ HURST, WS ROSASCO, GJ AF BEAN, VE BOWERS, WJ HURST, WS ROSASCO, GJ TI DEVELOPMENT OF A PRIMARY STANDARD FOR THE MEASUREMENT OF DYNAMIC PRESSURE AND TEMPERATURE SO METROLOGIA LA English DT Article; Proceedings Paper CT 2nd International Seminar on Pressure Metrology from 1 kPa to 1 GPa CY JUN 02-04, 1993 CL LAB NATL ESSAIS, PARIS, FRANCE SP D H INSTRUMENTS CO, USA, RUSKA CO, USA HO LAB NATL ESSAIS AB The National Institute of Standards and Technology is developing a primary standard for the measurement of dynamic pressure and temperature. Our method requires a dynamic source and a technique for calibrating it. The source is a shock tube; the calibration technique is based on die properties of diatomic gas molecules measured by laser spectroscopic methods. RP BEAN, VE (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 8 TC 7 Z9 7 U1 1 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 APR PY 1994 VL 30 IS 6 BP 747 EP 750 DI 10.1088/0026-1394/30/6/039 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA NV370 UT WOS:A1994NV37000040 ER PT J AU ALTMAN, SA ZASTAWNY, TH RANDERS, L LIN, ZL LUMPKIN, JA REMACLE, J DIZDAROGLU, M RAO, G AF ALTMAN, SA ZASTAWNY, TH RANDERS, L LIN, ZL LUMPKIN, JA REMACLE, J DIZDAROGLU, M RAO, G TI TERT-BUTYL HYDROPEROXIDE-MEDIATED DNA-BASE DAMAGE IN CULTURED-MAMMALIAN-CELLS SO MUTATION RESEARCH LA English DT Article ID HYDROGEN-PEROXIDE; DEOXYRIBONUCLEIC-ACID; ESCHERICHIA-COLI; OXIDATIVE DAMAGE; SUPEROXIDE; CHROMATIN; HEPATOCYTES; RADICALS; IRON; CARCINOGENESIS AB tert.-Butyl hydroperoxide has been utilized to study the effect of oxidative stress on living cells; however, its effect on DNA bases in cells has not been characterized. In the present work, we have investigated DNA base damage in mammalian cells exposed to this organic hydroperoxide. SP2/0 derived murine hybridoma cells were treated with 4 concentrations of tert.-butyl hydroperoxide for varying periods of time. Chromatin was isolated from treated and control cells and subsequently analyzed by gas chromatography-mass spectrometry with selected-ion monitoring for DNA base damage. Quantification of damaged DNA bases was achieved by isotope-dilution mass spectrometry. The amounts of 8 products were significantly higher than control levels in cells treated with tert.-butyl hydroperoxide at a concentration range of 0.01-0.1 mM. At concentrations from 1.0 to 10 mM, product formation was inhibited and the amounts of products were similar to those in control cells. The bimodal nature of the dose-response may be qualitatively analogous to previous reports of bimodal killing of E. coli bacteria by hydrogen peroxide. The nature of the identified DNA base lesions suggests the involvement of the hydroxyl radical in their formation. tert.-Butyl hydroperoxide is known to produce the tert.-butoxyl radical in reactions with metal ions. However, it is unlikely that the tert.-butoxyl radical produces these DNA lesions. It is suggested that DNA base damage arises from tert.-butyl hydroperoxide-mediated oxidative stress in cells, resulting in formation of hydroxyl radicals in close proximity to DNA. The inhibition of product formation at high concentrations of tert.-butyl hydroperoxide may be explained by the scavenging of tert.-butoxyl radical by tert.-butyl hydroperoxide resulting in inhibition of oxidative stress. The Plausibility of the scavenging mechanism was evaluated with a mathematical simulation of the dose-response for DNA damage in solutions containing hydrogen peroxide. The simulation model predicted a bimodal dose-response which agreed qualitatively with the results in this study and with other in vivo and in vitro studies reported in the literature. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM ENGN,227 TECHNOL RES CTR,CATONSVILLE,MD 21228. NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR MED BIOTECHNOL,BALTIMORE,MD 21201. FAC UNIV NOTRE DAME PAIX,BIOCHIM CELLULAIRE LAB,B-5000 NAMUR,BELGIUM. RI Lin, Zhanglin/A-7232-2011 FU NCRR NIH HHS [RR-06562] NR 39 TC 61 Z9 63 U1 6 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8262 J9 MUTAT RES PD APR 1 PY 1994 VL 306 IS 1 BP 35 EP 44 DI 10.1016/0027-5107(94)90165-1 PG 10 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA ND637 UT WOS:A1994ND63700004 PM 7512201 ER PT J AU THOMSON, RE MORELAND, J ROSHKO, A AF THOMSON, RE MORELAND, J ROSHKO, A TI SURFACE MODIFICATION OF YBA2CU3O7-DELTA THIN-FILMS USING THE SCANNING TUNNELING MICROSCOPE - 5 METHODS SO NANOTECHNOLOGY LA English DT Review ID ATOMIC-FORCE; OXYGEN; GOLD; SUPERCONDUCTORS; TEMPERATURE; TOPOGRAPHY AB We have investigated using the scanning tunneling microscope (STM) as a tool for surface modification of YBa2Cu3O7-delta (YBCO) thin films and have identified five distinct methods whereby the STM tip can modify the superconductor surface. (i) By lowering the tunneling resistance we make the tip scratch or 'mill' the sample surface mechanically. (ii) By increasing the bias voltage above about 4 V we can modify the surface by an apparent electron beam damaging process. (iii) By increasing the bias voltage above 10 V and raising the tunneling current, we can cause a more dramatic effect which is probably due to a thermal process. (iv) By operating the STM in a damp carbon dioxide atmosphere we can cause the STM tip to etch the surface electrochemically. (v) Finally, we have some preliminary data suggesting that the high field under an extremely sharp tip displaces the oxygen atoms in the YBCO lattice. Examples of each of these techniques are shown and discussed. RP NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. NR 27 TC 34 Z9 34 U1 2 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 EI 1361-6528 J9 NANOTECHNOLOGY JI Nanotechnology PD APR PY 1994 VL 5 IS 2 BP 57 EP 69 DI 10.1088/0957-4484/5/2/001 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA PN222 UT WOS:A1994PN22200001 ER PT J AU MOHR, PJ AF MOHR, PJ TI QED EFFECTS IN HIGH-Z FEW-ELECTRON ATOMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 16th International Conference on X-ray and Inner-Shell Process (X 93) CY JUL 12-16, 1993 CL HUNGARIAN ACAD SCI, INST NUCL RES, DEBRECEN, HUNGARY SP CITY DEBRECEN, CTY HAJDU BIHAR, EUROPEAN PHYS SOC, HUNGARY ACAD SCI, INT SCI FDN, INT UNION PURE & APPL PHYS, PROFESSOR KAZUOSHI WAKIYA, MINIST IND & TRADE HUNGARY, NATL COMM TECHNOL DEV HUNGARY, SOROS FDN, UNIV DEBRECEN HO HUNGARIAN ACAD SCI, INST NUCL RES ID HYDROGEN-LIKE ATOMS; SELF-ENERGY; QUANTUM ELECTRODYNAMICS; VACUUM POLARIZATION; HEAVY-ATOMS; LAMB SHIFT; BINDING; FIELD AB Calculations of quantum electrodynamic (QED) effects in high-Z few-electron atoms are reviewed. Attention is focused on the specific example of the ground state of one- and two-electron uranium. Based on currently available theoretical results from QED, the energy level of the 1S state of hydrogen-like uranium is E(1S) = -131 815.0(6) eV and the energy level of the 1(1)S0 state in helium-like uranium is E(1S-1(0)) = -261383(4) eV. The effects considered here are relevant to the innermost level in heavy neutral atoms as well. RP MOHR, PJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 37 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1994 VL 87 IS 1-4 BP 232 EP 236 DI 10.1016/0168-583X(94)95265-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NJ597 UT WOS:A1994NJ59700038 ER PT J AU SOUTHWORTH, SH AF SOUTHWORTH, SH TI RESONANCE AND THRESHOLD EFFECTS IN POLARIZED X-RAY-EMISSION FROM ATOMS AND MOLECULES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 16th International Conference on X-ray and Inner-Shell Process (X 93) CY JUL 12-16, 1993 CL HUNGARIAN ACAD SCI, INST NUCL RES, DEBRECEN, HUNGARY SP CITY DEBRECEN, CTY HAJDU BIHAR, EUROPEAN PHYS SOC, HUNGARY ACAD SCI, INT SCI FDN, INT UNION PURE & APPL PHYS, PROFESSOR KAZUOSHI WAKIYA, MINIST IND & TRADE HUNGARY, NATL COMM TECHNOL DEV HUNGARY, SOROS FDN, UNIV DEBRECEN HO HUNGARIAN ACAD SCI, INST NUCL RES ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; FLUORESCENCE; SCATTERING; CHLOROFLUOROMETHANES; PERFORMANCE; ABSORPTION AB Strongly anisotropic and polarized K-V (valence to K-vacancy) X-ray emission has been observed from gas-phase molecules following excitation of a K-shell electron to valence-like subthreshold resonances using a narrow bandwidth, linearly polarized X-ray beam. Distinctively different polarizations and angular distributions are observed for emission involving molecular orbitals of different symmetries. A classical model of the X-ray absorption/emission process accurately describes the observed radiation pattems. Relatively weak polarizations and anisotropies are observed following excitation of atomic subthreshold resonances, due to averaging over unresolved final states. However, resonance and threshold studies of atomic X-ray spectra illustrate the inelastic resonance scattering process and the onset of characteristic fluorescence. RP SOUTHWORTH, SH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 27 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1994 VL 87 IS 1-4 BP 247 EP 252 DI 10.1016/0168-583X(94)95268-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NJ597 UT WOS:A1994NJ59700041 ER PT J AU MIAO, QM THUNELL, RC ANDERSON, DM AF MIAO, QM THUNELL, RC ANDERSON, DM TI GLACIAL-HOLOCENE CARBONATE DISSOLUTION AND SEA-SURFACE TEMPERATURES IN THE SOUTH CHINA AND SULU SEAS SO PALEOCEANOGRAPHY LA English DT Article ID OCEAN PLANKTONIC-FORAMINIFERA; INDIAN-OCEAN; CALCIUM-CARBONATE; PACIFIC; CIRCULATION; SEDIMENTS; LEVEL AB Sediment cores from the South China and Sulu seas have been used to study sea surface temperature changes in these two western equatorial Pacific basins during the last 25,000 years. Sea surface temperature (SST) estimates were derived using the planktonic foraminiferal transfer function FP-12E previously developed by Thompson (1981). The water depths for the cores range from 500 m to more than 4,000 m and thus provide a good opportunity to evaluate the effect of carbonate dissolution on quantitative paleotemperature estimates. The sea surface temperature time series from shallow, well-preserved cores indicate that average winter and summer temperatures during the Holocene were approximately 27-degrees-C and 29.5-degrees-C, respectively, for both the South China and Sulu seas. These estimates agree well with modem observations. During the last glacial maximum, summer sea surface temperatures were approximately 28.5-degrees-C in the South China Sea and 29-degrees-C in the Sulu Sea and thus were very similar to the Holocene. In contrast, glacial winter sea surface temperatures are estimated at approximately 21-degrees-C for the South China Sea and 24-degrees-C for the Sulu Sea. This decrease in glacial winter sea surface temperatures results in a much larger seasonality during the last glacial (5-degrees-8-degrees-C) compared to the Holocene (2-degrees-C). These seasonal contrasts are much greater than those estimated by Climate: Long-Range Investigation, Mapping, and Prediction Members (1981) for this region of the western equatorial Pacific. Variation in intensity of the monsoon system and surface water exchange rates between these basins and the open ocean are the major factors controlling glacial-interglacial SST fluctuations in the South China and Sulu seas. One factor influencing the accuracy of the SST estimates is the quality of preservation of the planktonic foraminiferal assemblages. Our results demonstrate that depth-dependent increases in dissolution result in systematically cooler SST estimates. This is due to the fact that warm water planktonic foraminifera tend to be more solution susceptible, and as dissolution progresses, the assemblage becomes enriched in the more resistant, cooler water taxa. Since dissolution is more intense during interglacials than glacials in the Pacific, dissolution tends to reduce the amplitude of the glacial-interglacial temperature difference. C1 UNIV S CAROLINA,DEPT GEOL SCI,COLUMBIA,SC 29208. NOAA,NATL GEOPHYS & SOLAR TERR DATA CTR,PALEOCLIMATOL PROGRAM,BOULDER,CO 80303. RI anderson, david/E-6416-2011 NR 44 TC 85 Z9 118 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD APR PY 1994 VL 9 IS 2 BP 269 EP 290 DI 10.1029/93PA02830 PG 22 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA NH622 UT WOS:A1994NH62200006 ER PT J AU BLUE, JL CANDELA, GT GROTHER, PJ CHELLAPPA, R WILSON, CL AF BLUE, JL CANDELA, GT GROTHER, PJ CHELLAPPA, R WILSON, CL TI EVALUATION OF PATTERN CLASSIFIERS FOR FINGERPRINT AND OCR APPLICATIONS SO PATTERN RECOGNITION LA English DT Article DE EVALUATION OF CLASSIFIERS; OPTICAL CHARACTER RECOGNITION; FINGERPRINTS; PROBABILISTIC NEURAL NETWORKS; RADIAL BASIS FUNCTIONS; STATISTICAL CLASSIFIERS; NEURAL NETWORKS ID RECOGNITION; NETWORKS AB The classification accuracy of four statistical and three neural network classifiers for two image based pattern classification problems is evaluated, These are optical character recognition (OCR) for isolated handprinted digits, and fingerprint classification. It is hoped that the evaluation results reported will be useful for designers of practical systems for these two important commercial applications. For the OCR problem, the Karhunen Loeve (K-L) transform of the images is used to generate the input feature set. Similarly for the fingerprint problem, the K-L transform of the ridge directions is used to generate the input feature set. The statistical classifiers used are Euclidean minimum distance, quadratic minimum distance, normal, and k-nearest neighbor. The neural network classifiers used are multi-layer perceptron, radial basis function, and probabilistic neural network- The OCR data consist of 7480 digit images for training and 23,140 digit images for testing. The fingerprint data used consist of 2000 training and 2000 testing images. In addition to evaluation for accuracy. the multi-layer perceptron and radial basis function networks are evaluated for size and generalization capability. For the evaluated datasets the best accuracy obtained for either problem is provided by a probabilistic neural network. Minimum classification error is 2.5% for OCR and 7.2%) for fingerprints. C1 UNIV MARYLAND,DEPT ELECT ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,CTR AUTOMAT RES,COLLEGE PK,MD 20742. UNIV MARYLAND,DEPT COMP SCI,COLLEGE PK,MD 20742. UNIV MARYLAND,INST ADV COMP STUDIES,COLLEGE PK,MD 20742. RP BLUE, JL (reprint author), NATL INST STAND & TECHNOL,MATH MODELING GRP,GAITHERSBURG,MD 20899, USA. NR 53 TC 66 Z9 68 U1 5 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0031-3203 J9 PATTERN RECOGN JI Pattern Recognit. PD APR PY 1994 VL 27 IS 4 BP 485 EP 501 DI 10.1016/0031-3203(94)90031-0 PG 17 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA NK592 UT WOS:A1994NK59200003 ER PT J AU NOLLE, CS KOILLER, B MARTYS, N ROBBINS, MO AF NOLLE, CS KOILLER, B MARTYS, N ROBBINS, MO TI EFFECT OF QUENCHED DISORDER ON MOVING INTERFACES IN 2 DIMENSIONS SO PHYSICA A LA English DT Article; Proceedings Paper CT 1st IUPAP Topical Conference/2nd Taipei International Symposium on Statistical Physics: Order-Disorder Transitions and Criticality CY AUG 01-07, 1993 CL TAIPEI, TAIWAN SP INT UNION PURE & APPL PHYS ID CHARGE-DENSITY WAVES; AFFINE FRACTAL INTERFACES; POROUS-MEDIA; FLUID INVASION; SELF-AFFINE; IMMISCIBLE DISPLACEMENT; DOMAIN GROWTH; MODEL; PERCOLATION; TRANSITION AB We consider the morphology and dynamics of an interface driven through a random two-dimensional medium by an applied force f. The onset of motion is a critical phenomenon, with mean velocity upsilon approximately (f - f(c))zeta above the threshold force f(c). Fluctuations in the velocity exhibit a power law noise spectrum. At large length scales the moving interfaces are self-affine with roughness exponent alpha = 0.5. There is a crossover to different scaling behavior below the correlation length, xi approximately (f - f(c))-nu. The type of scaling at small lengths depends upon the nature and strength of the disorder. Two examples are considered - a magnetic domain wall model exhibiting self-similar structure characteristic of percolation, and a fluid invasion model which produces self-affine scaling. C1 PONTIFICIA UNIV CATOLICA RIO DE JANEIRO,DEPT FIS,BR-22453 RIO JANEIRO,BRAZIL. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP NOLLE, CS (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 36 TC 15 Z9 15 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD APR 1 PY 1994 VL 205 IS 1-3 BP 342 EP 354 DI 10.1016/0378-4371(94)90512-6 PG 13 WC Physics, Multidisciplinary SC Physics GA NG610 UT WOS:A1994NG61000027 ER PT J AU SCHRODER, A LYNN, JW ERWIN, RW LOEWENHAUPT, M VONLOHNEYSEN, H AF SCHRODER, A LYNN, JW ERWIN, RW LOEWENHAUPT, M VONLOHNEYSEN, H TI MAGNETIC-STRUCTURE OF THE HEAVY-FERMION ALLOY CECU5.5AU0.5 SO PHYSICA B LA English DT Article; Proceedings Paper CT International Conference on Strongly Correlated Electron Systems (SCES 93) CY AUG 16-19, 1993 CL UNIV CALIF SAN DIEGO, SAN DIEGO, CA SP UNIV CALIF SAN DIEGO, INST PURE & APPL PHYS SCI, UNIV CALIF SAN DIEGO, AMER PHYS SCI, INST MECH & MAT, INT SCI FDN, WASHINGTON, DC, LOS ALAMOS NATL LAB, NATL HIGH MAGNET FIELD LAB, US DOE, US NATL SCI FDN HO UNIV CALIF SAN DIEGO AB Neutron diffraction measurements were performed on a single crystal of the heavy fermion compound CeCu5.5Au0.5. Below TN = 1.00 +/- 0.05 K an incommensurate magnetic structure was found with wave vector q = (+/- 0.59, 0, 0), which completely explains the previous powder diffraction data. This wave vector differs from the wave vectors characterizing the correlated fluctuations in CeCu6, where q along the a direction is commensurate. C1 FORSCHUNGSZENTRUM JULICH,IFF,JULICH,GERMANY. UNIV KARLSRUHE,INST PHYS,W-7500 KARLSRUHE,GERMANY. NIST,RRD,GAITHERSBURG,MD 20899. RP SCHRODER, A (reprint author), MCMASTER UNIV,DEPT PHYS,HAMILTON L8S 4M1,ONTARIO,CANADA. NR 8 TC 41 Z9 41 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1994 VL 199 BP 47 EP 48 DI 10.1016/0921-4526(94)91733-7 PG 2 WC Physics, Condensed Matter SC Physics GA NV538 UT WOS:A1994NV53800018 ER PT J AU SINHA, SK SANYAL, MK SATIJA, SK MAJKRZAK, CF NEUMANN, DA HOMMA, H SZPALA, S GIBAUD, A MORKOC, H AF SINHA, SK SANYAL, MK SATIJA, SK MAJKRZAK, CF NEUMANN, DA HOMMA, H SZPALA, S GIBAUD, A MORKOC, H TI X-RAY-SCATTERING STUDIES OF SURFACE-ROUGHNESS OF GAAS/ALAS MULTILAYERS SO PHYSICA B LA English DT Article; Proceedings Paper CT International Conference on Surface X-Ray and Neutron Scattering (SXNS-3) CY JUN 24-29, 1993 CL DUBNA, RUSSIA SP JOINT INST NUCL RES, FRANK LAB NEUTRON PHYS, COMMISS EUROPEAN COMMUNITY ID NEUTRON-SCATTERING AB We discuss the theory of X-ray scattering from multilayers with conformal roughness of the interfaces, and illustrate with an analysis of specular, diffuse and wide-angle scattering from a GaAs/AlAs multilayer. This is a highly coherent multilayer structure deposited on a stepped, but otherwise smooth surface. The roughness due to the steps propagates through the layers and a distinct anisotropy is observed in the diffuse scattering. We discuss a method to treat diffuse scattering from such surfaces with slightly irregular steps. C1 BHABHA ATOM RES CTR,BOMBAY 40000885,INDIA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV ILLINOIS,URBANA,IL 61801. CUNY BROOKLYN COLL,BROOKLYN,NY 11210. UNIV MAINE,F-72017 LE MANS,FRANCE. RP SINHA, SK (reprint author), EXXON RES & ENGN CO,ANNANDALE,NJ 08801, USA. RI sanyal, milan/J-2527-2015 OI sanyal, milan/0000-0002-3847-8793 NR 12 TC 81 Z9 81 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1994 VL 198 IS 1-3 BP 72 EP 77 DI 10.1016/0921-4526(94)90131-7 PG 6 WC Physics, Condensed Matter SC Physics GA NR013 UT WOS:A1994NR01300020 ER PT J AU GIEBULTOWICZ, TM LUO, H SAMARTH, N FURDYNA, JK NUNEZ, V RHYNE, JJ FASCHINGER, W SPRINGHOLTZ, G BAUER, G SITTER, H AF GIEBULTOWICZ, TM LUO, H SAMARTH, N FURDYNA, JK NUNEZ, V RHYNE, JJ FASCHINGER, W SPRINGHOLTZ, G BAUER, G SITTER, H TI STRAIN-INDUCED HELIMAGNETISM, FINITE THICKNESS EFFECTS, AND INTERLAYER COUPLING IN MAGNETIC SEMICONDUCTOR MULTILAYERS SO PHYSICA B LA English DT Article; Proceedings Paper CT International Conference on Surface X-Ray and Neutron Scattering (SXNS-3) CY JUN 24-29, 1993 CL DUBNA, RUSSIA SP JOINT INST NUCL RES, FRANK LAB NEUTRON PHYS, COMMISS EUROPEAN COMMUNITY ID ANTIFERROMAGNETS; SUPERLATTICES AB Neutron diffraction studies of antiferromagnetic semiconductor superlattices are reviewed. Mn-VI/II-VI multilayers (e.g. MnSe/ZnTe, MnSe/ZnSe) exhibit a variety of strain-induced effects in spin ordering and phase transition phenomena. In MnTe/CdTe systems, in which the thickness of the non-magnetic CdTe spacers can be very thin (approximately 6 angstrom) and comparable with the range of the Mn-Mn exchange interactions, the measurements clearly show the onset of interlayer coupling. Pronounced interlayer coupling has been observed in experiments on another system, EuTe/PbTe, with much thicker (30-40 angstrom) non-magnetic layers - arguably, this coupling is maintained by dipolar fields. C1 JOHANNES KEPLER UNIV,A-4040 LINZ,AUSTRIA. UNIV MARYLAND,COLL PK,MD 20742. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. UNIV MISSOURI RES REACTOR,COLUMBIA,MO 65211. RP GIEBULTOWICZ, TM (reprint author), UNIV NOTRE DAME,NOTRE DAME,IN 46556, USA. RI Samarth, Nitin/C-4475-2014 OI Samarth, Nitin/0000-0003-2599-346X NR 12 TC 10 Z9 10 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1994 VL 198 IS 1-3 BP 163 EP 168 DI 10.1016/0921-4526(94)90152-X PG 6 WC Physics, Condensed Matter SC Physics GA NR013 UT WOS:A1994NR01300041 ER PT J AU WIESLER, DG MAJKRZAK, CF AF WIESLER, DG MAJKRZAK, CF TI NEUTRON REFLECTOMETRY STUDIES OF SURFACE OXIDATION SO PHYSICA B LA English DT Article; Proceedings Paper CT International Conference on Surface X-Ray and Neutron Scattering (SXNS-3) CY JUN 24-29, 1993 CL DUBNA, RUSSIA SP JOINT INST NUCL RES, FRANK LAB NEUTRON PHYS, COMMISS EUROPEAN COMMUNITY ID OXIDE FILM; TITANIUM; TIO2 AB We have employed neutron reflectometry to study the thickness and density of thin oxide films of Ti in contact with electrolyte. Such films play an important role in corrosion resistance and surface chemistry in aqueous environments. We compare the structures of such oxides formed by either ramping the potential or by step polarization. The effect of subsequent cathodic bias on the films is explored, and the time evolution of the hydrogen content in the oxide and metal is investigated. RP WIESLER, DG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 24 Z9 25 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1994 VL 198 IS 1-3 BP 181 EP 186 DI 10.1016/0921-4526(94)90156-2 PG 6 WC Physics, Condensed Matter SC Physics GA NR013 UT WOS:A1994NR01300045 ER PT J AU SCHREYER, A ANKNER, JF ZABEL, H SCHAFER, M MAJKRZAK, CF GRUNBERG, P AF SCHREYER, A ANKNER, JF ZABEL, H SCHAFER, M MAJKRZAK, CF GRUNBERG, P TI DIRECT OBSERVATION OF NONCOLLINEAR SPIN STRUCTURES IN FE/CR(100) SUPERLATTICES USING SPIN-POLARIZED NEUTRON REFLECTIVITY SO PHYSICA B-CONDENSED MATTER LA English DT Article ID FE LAYERS; OSCILLATIONS AB Using the sensitivity of spin polarized neutron reflectivity with exit beam polarization analysis to the orientation of the in-plane magnetic moment, we have directly observed a non-collinear magnetization profile in Fe/Cr (1 0 0) superlattices which results from biquadratic coupling. A new approach is presented which allows the quantitative understanding of the data and which leads to detailed conclusions about the magnetization profile and magnetic domain structure in the sample. These conclusions are fully validated by domain observations with Kerr microscopy. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. FORSCHUNGSZENTRUM JULICH, D-52425 JULICH, GERMANY. RP SCHREYER, A (reprint author), RUHR UNIV BOCHUM, D-44780 BOCHUM, GERMANY. RI Zabel, Hartmut/C-1994-2009; OI Ankner, John/0000-0002-6737-5718 NR 13 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD APR PY 1994 VL 198 IS 1-3 BP 173 EP 176 DI 10.1016/0921-4526(94)90154-6 PG 4 WC Physics, Condensed Matter SC Physics GA NR013 UT WOS:A1994NR01300043 ER PT J AU STOREY, P SLEATOR, T COLLETT, M WALLS, D AF STOREY, P SLEATOR, T COLLETT, M WALLS, D TI CONTRACTIVE STATES OF A FREE ATOM SO PHYSICAL REVIEW A LA English DT Article ID STANDARD QUANTUM LIMIT; PODOLSKY-ROSEN PARADOX; FREE-MASS POSITION AB A position-measurement scheme is discussed which prepares an atom in a contractive state. Two operating regimes are analyzed. In the first, the quadratic form of the interaction potential is responsible for the focusing. In the second regime the potential varies approximately linearly with position, and the focusing results from the measurement itself. In this second regime the scheme provides a very close realization of the Einstein-Podolsky-Rosen Gedankenexperiment an analogy that allows some insight into the production of measurement-induced contractive states. C1 NYU,DEPT PHYS,NEW YORK,NY 10003. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP STOREY, P (reprint author), UNIV AUCKLAND,DEPT PHYS,PRIVATE BAG 92019,AUCKLAND,NEW ZEALAND. RI Collett, Matthew/B-4762-2010 NR 13 TC 34 Z9 34 U1 1 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 APR PY 1994 VL 49 IS 4 BP 2322 EP 2328 DI 10.1103/PhysRevA.49.2322 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NG485 UT WOS:A1994NG48500017 ER PT J AU MARZOLI, I CIRAC, JI BLATT, R ZOLLER, P AF MARZOLI, I CIRAC, JI BLATT, R ZOLLER, P TI LASER COOLING OF TRAPPED 3-LEVEL IONS - DESIGNING 2-LEVEL SYSTEMS FOR SIDE-BAND COOLING SO PHYSICAL REVIEW A LA English DT Article AB Laser cooling of three-level ions of the cascade, vee, and lambda configuration is considered with simultaneous excitation on a weak and strong transition. Choosing appropriate parameters for the Rabi frequencies and the respective detunings allows one to eliminate adiabatically one of the levels. The thus designed two-level ion can acquire decay rates GAMMA' smaller than the trap frequency nu such that sideband cooling becomes possible and accordingly allows cooling of the ion to its lowest oscillator state [n] = 0 in the trap. Explicit expressions for the detunings and the Pabi frequencies for sideband cooling of the effective two-level system are derived. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. UNIV CASTILLA LA MANCHA,FAC CIENCIAS QUIM,DEPT FIS APLICADA,E-13071 CIUDAD REAL,SPAIN. UNIV HAMBURG,INST LASER PHYS,D-20355 HAMBURG,GERMANY. RP MARZOLI, I (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Zoller, Peter/O-1639-2014 OI Zoller, Peter/0000-0003-4014-1505 NR 15 TC 85 Z9 86 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1994 VL 49 IS 4 BP 2771 EP 2779 DI 10.1103/PhysRevA.49.2771 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA NG485 UT WOS:A1994NG48500074 ER PT J AU COFFEY, MW AF COFFEY, MW TI DEFORMABLE SUPERCONDUCTOR MODEL FOR THE FLUXON MASS SO PHYSICAL REVIEW B LA English DT Article ID INERTIAL MASS; VORTEX; CREEP AB Outstanding difficulties in a deformable type-II superconductor model for the fluxon inertial mass per unit length mu(d) are resolved. An identity for the inertial mass, valid for an arbitrary quasiparticle fraction when the ionic displacement field is irrotational, plays a critical role in the analysis. This approach avoids previously employed approximations, leading to qualitatively different results, including a fluxon mass which properly vanishes at the transition temperature and which has a greatly reduced magnitude. A framework for the solution of the elasticity equation for an isotropic superconductor is presented and the close relation between mu(d) and the ionic strain field is shown. RP COFFEY, MW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 20 TC 30 Z9 30 U1 2 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 APR 1 PY 1994 VL 49 IS 14 BP 9774 EP 9777 DI 10.1103/PhysRevB.49.9774 PG 4 WC Physics, Condensed Matter SC Physics GA NG486 UT WOS:A1994NG48600054 ER PT J AU CHATTOPADHYAY, T LYNN, JW ROSOV, N GRIGEREIT, TE BARILO, SN ZHIGUNOV, DI AF CHATTOPADHYAY, T LYNN, JW ROSOV, N GRIGEREIT, TE BARILO, SN ZHIGUNOV, DI TI MAGNETIC-ORDERING IN EU2CUO4 SO PHYSICAL REVIEW B LA English DT Article ID PHASE-TRANSITIONS; NEUTRON-SCATTERING; ND2CUO4; SUPERCONDUCTIVITY; R2CUO4; PR2CUO4 AB Neutron-diffraction experiments have been performed to study the magnetic ordering of Cu ions in a single crystal of Eu2CuO4. Magnetic reflections corresponding to the wave vector k=(1/2, 1/2, 0) develop below the Neel temperature T(N) = 265(5) K, showing a long-range antiferromagnetic ordering of Cu moments in Eu2CuO4. The low-temperature saturated moment was determined to be (0.4 +/- 0.1)mu(B), with the spin direction restricted to the a-b plane. Magnetic-field-dependent studies show no hysteretic behavior at intermediate temperatures, which strongly suggests that the antiferromagnetic spin structure is of the noncollinear double-k type previously observed in Sm2CuO4 and also in Nd2CuO4 at the intermediate temperature. We do not find any evidence of spin reorientation below the Neel temperature down to 1.4 K, the lowest temperature investigated. C1 UNIV MARYLAND,CTR SUPERCONDUCT RES,DEPT PHYS,COLL PK,MD 20742. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. BELARUSSIAN ACAD SCI,INST PHYS SOLIDS & SEMICOND,MINSK 220726,BYELARUS. RP CHATTOPADHYAY, T (reprint author), INST MAX VON LAUE PAUL LANGEVIN,BOITE POSTALE 156X,F-38042 GRENOBLE,FRANCE. NR 30 TC 30 Z9 30 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 1994 VL 49 IS 14 BP 9944 EP 9948 DI 10.1103/PhysRevB.49.9944 PG 5 WC Physics, Condensed Matter SC Physics GA NG486 UT WOS:A1994NG48600073 ER PT J AU MARTYS, N BENTZ, DP GARBOCZI, EJ AF MARTYS, N BENTZ, DP GARBOCZI, EJ TI COMPUTER-SIMULATION STUDY OF THE EFFECTIVE VISCOSITY IN BRINKMAN EQUATION SO PHYSICS OF FLUIDS LA English DT Article ID DIMENSIONAL POROUS-MEDIA; MICROSCOPIC FLOW; SURFACE; RENORMALIZATION; SCALES; MODEL AB Brinkman's equation is often used to match solutions of Stokes' equation to solutions of Darcy's law at free-fluid:porous medium interfaces by the introduction of an effective viscosity parameter, mu(e). Theoretical predictions of the dependence Of mu(e) on the porosity of the porous medium have given conflicting results. A finite difference solution of Stokes' equation in three dimensions was used to study fluid flow near the interface between a free fluid and a porous medium. It was found that in order to match solutions of Brinkman's equation to the numerical solutions, the value of mu(e) had to be greater than the free-fluid viscosity. Within numerical precision, the effective viscosity mu(e) was monotonically increasing with decreasing porosity. Good fits to the numerical fluid velocity profiles were obtained for porosities ranging from 50% to 80%. RP MARTYS, N (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,DIV BLDG MAT,226-B348,GAITHERSBURG,MD 20899, USA. NR 22 TC 75 Z9 76 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD APR PY 1994 VL 6 IS 4 BP 1434 EP 1439 DI 10.1063/1.868258 PG 6 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA NB666 UT WOS:A1994NB66600004 ER PT J AU BUR, AJ WANG, FW THOMAS, CL ROSE, JL AF BUR, AJ WANG, FW THOMAS, CL ROSE, JL TI IN-LINE OPTICAL MONITORING OF POLYMER INJECTION-MOLDING SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID INTRAMOLECULAR EXCIMER FORMATION; FLUORESCENCE POLARIZATION; EPOXY-RESINS; FREE-VOLUME; DYNAMICS; ORIENTATION; VISCOSITY; MOTIONS; PROBES; MELTS AB An optical sensor, consisting of optical fibers to transmit light to and from the mold cavity, was constructed for the purpose of measuring the onset of polymer solidification during injection molding. The sensor was used to detect characteristic fluorescence radiation from a dye which had been doped into the resin at very low concentration. By measuring changes in fluorescence intensity it was possible to detect whether the state of the resin was liquid or solid. We observed that, as the resin cooled in the mold. the onset of solidification was indicated by highly characteristic and distinct changes in the fluorescence intensity/time profile. Application of the method involved the use of a calibration relationship between the fluorescence intensity and temperature of the doped polymer in order to deter-mine the distinct features which characterize the onset of solidification. Injection molding of a glass forming polymer (polystyrene) and a crystallizable polymer (polyethylene) was monitored by this technique. C1 DREXEL UNIV,DEPT MECH ENGN & MECH,PHILADELPHIA,PA 19104. RP BUR, AJ (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 29 TC 24 Z9 24 U1 1 U2 2 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 APR PY 1994 VL 34 IS 8 BP 671 EP 679 DI 10.1002/pen.760340809 PG 9 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA NJ191 UT WOS:A1994NJ19100008 ER PT J AU MALGHAN, SG PREMACHANDRAN, RS PEI, PT AF MALGHAN, SG PREMACHANDRAN, RS PEI, PT TI MECHANISTIC UNDERSTANDING OF SILICON-NITRIDE DISPERSION USING CATIONIC AND ANIONIC POLYELECTROLYTES SO POWDER TECHNOLOGY LA English DT Article ID STERIC STABILIZATION; FLOCCULATION; CERAMICS; POLYMERS; OXIDE AB The influence of interface properties of silicon nitride powder on the dispersion and particle size distribution in aqueous environments was investigated in the presence of cationic and anionic polyelectrolytes. The isoelectric point of as-received silicon nitride powder at pH 6.6 shifted to 4.0 in the presence of 1500 ppm ammonium polymethacrylate, an anionic polyelectrolyte (APE). However, no isoelectric point could be observed up to pH 10.8 when 1500 ppm quaternized polyamine epoxychlorohydrin, a cationic polyelectrolyte (CPE), was present in the silicon nitride suspensions. The dispersion characteristics of silicon nitride powder in the presence of various concentrations of the two polyelectrolytes and by pH variation were examined. The slightly better dispersion of silicon nitride powder in the presence of CPE than that in the presence of APE is explained in terms of differences in the adsorption characteristics and surface charge concentration in aqueous environments. A mechanistic understanding of the role of interface chemistry and, in particular, polyelectrolyte adsorption on the dispersion of silicon nitride powder is presented. RP MALGHAN, SG (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 20 TC 20 Z9 20 U1 0 U2 4 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 APR PY 1994 VL 79 IS 1 BP 43 EP 52 DI 10.1016/0032-5910(93)02792-9 PG 10 WC Engineering, Chemical SC Engineering GA NF616 UT WOS:A1994NF61600005 ER PT J AU PREMACHANDRAN, RS MALGHAN, SG AF PREMACHANDRAN, RS MALGHAN, SG TI DISPERSION CHARACTERISTICS OF CERAMIC POWDERS IN THE APPLICATION OF CATIONIC AND ANIONIC POLYELECTROLYTES SO POWDER TECHNOLOGY LA English DT Article ID SUSPENSIONS; ADSORPTION; POLYMERS; ALUMINA AB Dispersion characteristics of silicon nitride, silicon carbide, alumina, aluminum nitride and yttria powders in aqueous solutions of anionic and cationic polyelectrolytes were studied by measuring particle size distribution using a gravity sedimentation technique. The influence of polyelectrolyte concentration and suspension pH on the dispersion was examined. All powders examined in this study could be well dispersed in the presence of either cationic or anionic polyelectrolyte by adjusting the dispersion pH to at least 2.5 pH units away from the effective pH(iep) (iep=isoelectric point) of the powder-polyelectrolyte system. The dispersion characteristics of these powders in the presence of polyelectrolytes are explained in terms of interfacial interactions in the powder-polyelectrolyte systems. These interactions between the powder and polyelectrolytes as a function of suspension pH, and possible mechanisms leading to the stability of particles in a dispersion, are discussed. RP PREMACHANDRAN, RS (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 19 TC 22 Z9 22 U1 0 U2 2 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 APR PY 1994 VL 79 IS 1 BP 53 EP 60 DI 10.1016/0032-5910(93)02793-A PG 8 WC Engineering, Chemical SC Engineering GA NF616 UT WOS:A1994NF61600006 ER PT J AU FELDSTEIN, SB ROBINSON, WA AF FELDSTEIN, SB ROBINSON, WA TI SPATIAL STRUCTURE OF ULTRA-LOW FREQUENCY VARIABILITY OF THE FLOW IN A SIMPLE ATMOSPHERIC CIRCULATION MODEL - COMMENT SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article ID ANGULAR-MOMENTUM; HEMISPHERE AB James and James (1992) examine internally generated interannual variability in a multi-level primitive-equation model. The authors claim that the variability in the global mean relative angular velocity is associated with fluctuations in the mid-latitude zonally-averaged zonal winds. We question this relationship, and present results from an aqua-planet GCM which indicate that, instead, the global mean relative angular velocity is primarily related to changes in the tropical zonally-averaged zonal winds. Furthermore, we also question whether the 'ultra-low-frequency variability' examined by James and James is not simply just 'climate noise'. C1 UNIV ILLINOIS,URBANA,IL 61801. RP FELDSTEIN, SB (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI Robinson, Walter/I-3782-2012 OI Robinson, Walter/0000-0002-6669-7408 NR 11 TC 10 Z9 10 U1 0 U2 2 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 1994 VL 120 IS 517 BP 739 EP 745 DI 10.1002/qj.49712051714 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NP012 UT WOS:A1994NP01200013 ER PT J AU FARAHANI, M EICHMILLER, FC MCLAUGHLIN, WL AF FARAHANI, M EICHMILLER, FC MCLAUGHLIN, WL TI SHIELDING SMALL-FIELD HIGH-ENERGY ELECTRON-BEAMS IN CANCER-TREATMENT SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID RADIATION-THERAPY; IRRADIATION AB The purpose of this study was to find an effective material that can be prepared quickly and easily prior to small-held electron-beam treatments so that lesions of the head and neck can be treated with minimal irradiation of the surrounding healthy tissue. Conventional preparation of custom anatomical prosthetic radiation shields, which are usually metal alloy masks, has been time-consuming and uncomfortable for the patients. New materials, made from light-body Reprosil(TM) (L. L. Caulk) filled with fine metal powder consisting of 70% Ag-30% Cu alloy, can be made by blending 90% (w/w) metal powder with 10% polysiloxane base and adding the polymerization catalyst separately. These combinations were mixed to form comfortably fitted shielding composites of different thicknesses. The electron-beam attenuation properties of slabs of this material were studied by irradiating calibrated radiochromic him (GafChromic(TM)) dosimeters behind different thicknesses of composite samples with small-held 13-, 15- and 18-MeV electron beams from a therapeutic linear accelerator. The results showed that this material can suitably attenuate high-energy electron beams when used in reasonable thicknesses. RP FARAHANI, M (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,ADAHF PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 21 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-5724 J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD APR PY 1994 VL 43 IS 4 BP 357 EP 360 DI 10.1016/0969-806X(94)90027-2 PG 4 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA MM659 UT WOS:A1994MM65900011 ER PT J AU SCHAUER, DA DESROSIERS, MF LE, FG SELTZER, SM LINKS, JM AF SCHAUER, DA DESROSIERS, MF LE, FG SELTZER, SM LINKS, JM TI EPR DOSIMETRY OF CORTICAL BONE AND TOOTH ENAMEL IRRADIATED WITH X-RAYS AND GAMMA-RAYS - STUDY OF ENERGY-DEPENDENCE SO RADIATION RESEARCH LA English DT Article ID INVIVO RADIATION DOSIMETER; DENTAL ENAMEL; ELECTRON AB Previous investigators have reported that the radiation-induced EPR signal intensity in compact or cortical bone increases up to a factor of two with decreasing photon energy for a given absorbed dose. If the EPR signal intensity was dependent on energy, it could limit the application of EPR spectrometry and the additive reirradiation method to obtain dose estimates. We have recently shown that errors in the assumptions governing conversion of measured exposure to absorbed dose can lead to similar ''apparent'' energy-dependence results. We hypothesized that these previous results were due to errors in the estimated dose in bone, rather than the effects of energy dependence per se. To test this hypothesis we studied human adult cortical bone from male and female donors ranging in age from 23 to 95 years, and bovine tooth enamel, using 34 and 138 keV average energy X-ray beams and Cs-137 (662 keV) and Co-60 (1250 keV) gamma rays. In a femur from a 47-year-old male (subject I), there was a difference of borderline significance at the alpha = 0.05 level in the mean radiation-induced hydroxyapatite signal intensities as a function of photon energy. No other statistically significant differences in EPR signal intensity as a function of photon energy were observed in this subject, or in the tibia from a 23-year-old male (subject 2) and the femur from a 75-year-old female (subject 3). However, there was a trend toward a decrease (12-15%) in signal intensity at the lowest energy compared with the highest energy in subjects 1 and 3. Further analysis of the data from subject 1 revealed that this trend, which is in the opposite direction of previous reports but is consistent with theory, is statistically significant. There were no effects of energy dependence in the tooth samples. C1 JOHNS HOPKINS MED INST,SCH HYG & PUBL HLTH,DIV RADIAT HLTH SCI,BALTIMORE,MD 21205. JOHNS HOPKINS MED INST,SCH HYG & PUBL HLTH,DIV NUCL MED,BALTIMORE,MD 21205. RP SCHAUER, DA (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,TECHNOL ADM,GAITHERSBURG,MD 20899, USA. NR 16 TC 32 Z9 34 U1 1 U2 3 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD APR PY 1994 VL 138 IS 1 BP 1 EP 8 DI 10.2307/3578840 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA NE501 UT WOS:A1994NE50100001 PM 8146288 ER PT J AU BUCKMAN, SJ CLARK, CW AF BUCKMAN, SJ CLARK, CW TI ATOMIC NEGATIVE-ION RESONANCES SO REVIEWS OF MODERN PHYSICS LA English DT Review ID DOUBLY-EXCITED-STATES; ELECTRON-IMPACT EXCITATION; LOW-ENERGY ELECTRON; DIFFERENTIAL CROSS-SECTIONS; 2-ELECTRON IONIZATION LADDER; N = 3; PLUS POLARIZATION FORMULATION; FREE RADIATIVE TRANSITIONS; POST-COLLISION INTERACTION; NEAR-THRESHOLD EXCITATION AB The authors attempt to give a comprehensive discussion of observations of atomic negative-ion resonances throughout the periodic table. A review of experimental and theoretical approaches to the study of negative-ion resonances is given together with a consideration of the various schemes that are used for their classification. In addition to providing, where possible, tabulated data for the energies, widths, and symmetries of these states, the authors also attempt to highlight regularities in their behavior both within groups of the periodic table and along isoionic sequences. C1 NATL INST STANDARDS & TECHNOL,DIV ELECTR & OPT PHYS,TECHNOL ADM,GAITHERSBURG,MD 20899. RP BUCKMAN, SJ (reprint author), AUSTRALIAN NATL UNIV,INST ADV STUDIES,RES SCH PHYS SCI & ENGN,ELECTR PHYS GRP,CANBERRA,ACT 2601,AUSTRALIA. RI Clark, Charles/A-8594-2009; Buckman, Stephen/B-4750-2009 OI Clark, Charles/0000-0001-8724-9885; NR 712 TC 294 Z9 297 U1 0 U2 24 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 APR PY 1994 VL 66 IS 2 BP 539 EP 655 DI 10.1103/RevModPhys.66.539 PG 117 WC Physics, Multidisciplinary SC Physics GA NQ514 UT WOS:A1994NQ51400005 ER PT J AU CHAMEIDES, WL KASIBHATLA, PS YIENGER, J LEVY, H AF CHAMEIDES, WL KASIBHATLA, PS YIENGER, J LEVY, H TI GROWTH OF CONTINENTAL-SCALE METRO-AGRO-PLEXES, REGIONAL OZONE POLLUTION, AND WORLD FOOD-PRODUCTION SO SCIENCE LA English DT Article ID UNITED-STATES; PHOTOCHEMICAL PRODUCTION; MODEL AB Three regions of the northern mid-latitudes, the continental-scale metro-agro-plexes, presently dominate global industrial and agricultural productivity. Although these regions cover only 23 percent of the Earth's continents, they account for most of the world's commercial energy consumption, fertilizer use, food-crop production, and food exports. They also account for more than half of the world's atmospheric nitrogen oxide (NO(x)) emissions and, as a result, are prone to ground-level ozone (O3) pollution during the summer months. On the basis of a global simulation of atmospheric reactive nitrogen compounds, it is estimated that about 10 to 35 percent of the world's grain production may occur in parts of these regions where ozone pollution may reduce crop yields. Exposure to yield-reducing ozone pollution may triple by 2025 if rising anthropogenic NO(x) emissions are not abated. C1 PRINCETON UNIV, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. RP CHAMEIDES, WL (reprint author), GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. RI Kasibhatla, Prasad/A-2574-2010; OI Kasibhatla, Prasad/0000-0003-3562-3737 NR 39 TC 281 Z9 312 U1 2 U2 25 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 1 PY 1994 VL 264 IS 5155 BP 74 EP 77 DI 10.1126/science.264.5155.74 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ND536 UT WOS:A1994ND53600031 PM 17778137 ER PT J AU PARANTHAMAN, M FOLDEAKI, M BALZAR, D LEDBETTER, H NELSON, AJ HERMANN, AM AF PARANTHAMAN, M FOLDEAKI, M BALZAR, D LEDBETTER, H NELSON, AJ HERMANN, AM TI ENHANCED FLUX-PINNING VIA CHEMICAL SUBSTITUTION IN BULK SUPERCONDUCTING TL-2212 SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID NEUTRON-DIFFRACTION DATA; RIETVELD ANALYSIS; MOTION; MODEL AB The flux-pinning characteristics in both pure and doped superconducting Tl2Ba2CaCu2O8 (referred to as Tl-2212) systems were studied via DC magnetic hysteresis as well as flux-penetration and flux-expulsion measurements. At 5 K between 0 and 4.5 T, the 5 at.% Mg-doped Tl-2212 (Tl, Mg-2212) samples displayed enhanced pinning as demonstrated by a field-dependent increase of the magnetic critical current density J(c) by 18-25% as compared with the pure Tl-2212. Excess Mg (10-15 at.%), however, is deleterious. Rietveld refinement of the x-ray diffraction pattern showed Mg on the Tl sites. AES analysis showed part of the Mg appearing on grain boundaries. Both Tl-2212 and Tl, Mg-2212 displayed a persisting remanent magnetization M(rem) with a higher value for Tl, Mg-2212, as well as an asymmetrical behaviour between flux expulsion and flux penetration. The flux-creep activation energies are higher for flux expulsion than for flux penetration in both samples; Tl, Mg-2212 displayed higher individual values. Our results demonstrate an increase in both intrinsic pinning and lock-in transition of flux lines as a result of increased density of atomic-size structural defects via Mg doping in Tl-2212. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80303. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 20 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD APR PY 1994 VL 7 IS 4 BP 227 EP 233 DI 10.1088/0953-2048/7/4/008 PG 7 WC Physics, Applied; Physics, Condensed Matter SC Physics GA NF677 UT WOS:A1994NF67700008 ER PT J AU DAVIS, RW MOORE, EF CHEN, LD ROQUEMORE, WM VILIMPOC, V GOSS, LP AF DAVIS, RW MOORE, EF CHEN, LD ROQUEMORE, WM VILIMPOC, V GOSS, LP TI A NUMERICAL EXPERIMENTAL-STUDY OF THE DYNAMIC STRUCTURE OF A BUOYANT JET DIFFUSION FLAME SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS LA English DT Article ID VISUALIZATION AB An overview of a joint numerical/experimental investigation of the dynamic structure of a low-speed buoyant jet diffusion flame is presented. The dynamic interactions between the flame surface and the surrounding fluid mechanical structures are studied by means of a direct numerical simulation closely coordinated with experiments. The numerical simulation employs the full compressible axisymmetric Navier-Stokes equations coupled with a flame sheet model. Counterrotating vortex structures both internal and external to the flame surface are seen to move upward along with flame sheet bulges. These buoyancy-driven dynamic features compare well with those observed experimentally by means of phase-locked flow visualizations over entire flame-flickering cycles. The flicker frequencies measured both computationally and experimentally also compare well. Other aspects of this investigation which are discussed include sudden jumps in flicker frequency with increasing coflow velocity and the utilization of background pressure changes to simulate gravitational force variations experimentally. C1 UNIV IOWA,DEPT MECH ENGN,IOWA CITY,IA 52242. WRIGHT RES & DEV CTR,AERO PROPULS & POWER LAB,WRIGHT PATTERSON AFB,OH 45433. SYST RES LABS INC,DIV ARVIN CALSPAN,DAYTON,OH 45440. RP DAVIS, RW (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 24 TC 16 Z9 16 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0935-4964 J9 THEOR COMP FLUID DYN JI Theor. Comput. Fluid Dyn. PD APR PY 1994 VL 6 IS 2-3 BP 113 EP 123 DI 10.1007/BF00312344 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA NQ082 UT WOS:A1994NQ08200004 ER PT J AU BAUM, HR EZEKOYE, OA MCGRATTAN, KB REHM, RG AF BAUM, HR EZEKOYE, OA MCGRATTAN, KB REHM, RG TI MATHEMATICAL-MODELING AND COMPUTER-SIMULATION OF FIRE PHENOMENA SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS LA English DT Article AB An approach to the study of gas phase combustion and convection processes in fires using a combination of mathematical analysis and computer simulation is presented. It seeks to solve the governing equations directly (if approximately) by decomposing the fire into a large-scale convective and radiative transport problem coupled to a small-scale ''thermal-element'' model of combustion and radiative emission. The thermal-element model solves the combustion equations in a local Lagrangian coordinate system convected by the large-scale motion, which in turn is driven by the heat released by the combustion processes. The large-scale flow is studied using finite-difference techniques to solve large-eddy simulations of the Navier-Stokes equations. The basic theory behind the methodology is outlined and sample results of both large- and small-scale phenomena are presented. An analytical model of a large eddy is used to show how the simulation can be assembled to yield radiation feedback from a fire plume to a target surface. RP BAUM, HR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 21 Z9 22 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0935-4964 J9 THEOR COMP FLUID DYN JI Theor. Comput. Fluid Dyn. PD APR PY 1994 VL 6 IS 2-3 BP 125 EP 139 DI 10.1007/BF00312345 PG 15 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA NQ082 UT WOS:A1994NQ08200005 ER PT J AU MORRIS, CS GILL, SK AF MORRIS, CS GILL, SK TI VARIATION OF GREAT-LAKES WATER LEVELS DERIVED FROM GEOSAT ALTIMETRY SO WATER RESOURCES RESEARCH LA English DT Article ID SATELLITE ALTIMETRY AB A technique for using satellite radar altimetry data to estimate the temporal variation of the water level in moderate to large lakes and enclosed seas is described. Great Lakes data from the first 2 years of the U.S. Navy's Geosat Exact Repeat Mission (November 1986 to November 1988), for which there is an improved orbit, are used to demonstrate the technique. The Geosat results are compared to the lake level data collected by the Great Lakes Section, National Ocean Service, National Oceanic and Atmospheric Administration, and are found to reproduce the temporal variations of the five major lakes with root-mean-square error (rms) ranging from 9.4 to 13.8 cm and a combined average of 11.1 cm. Geosat data are also analyzed for Lake St. Clair, representing a moderate-sized lake, with a resulting rms of 17.0 cm. During this study period, the water level in the Great Lakes varied in a typical annual cycle of about 0.2 m (0.5 m for Lake Ontario) superimposed on a general decline of approximately 0.5 m. The altimeter data reproduced the general decline reasonably well for the lakes, but the annual cycle was obscured in some lakes due to systematic errors in the altimeter data. Current and future altimetry missions will have markedly improved accuracy which will permit many moderate (25 km diameter) or larger lakes or enclosed seas to be routinely monitored. C1 NOAA,NATL OCEAN SERV,SILVER SPRING,MD 20910. RP MORRIS, CS (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 18 TC 34 Z9 38 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1994 VL 30 IS 4 BP 1009 EP 1017 DI 10.1029/94WR00064 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA NE300 UT WOS:A1994NE30000015 ER PT J AU TATARSKII, VI TATARSKII, VV AF TATARSKII, VI TATARSKII, VV TI STATISTICAL DESCRIPTION OF ROUGH-SURFACE SCATTERING USING THE QUASI-SMALL-SLOPE APPROXIMATION FOR RANDOM SURFACES WITH A GAUSSIAN MULTIVARIATE PROBABILITY-DISTRIBUTION SO WAVES IN RANDOM MEDIA LA English DT Article AB In a previous paper we presented the quasi-slope expansion for the scattering amplitude for the problem of wave scattering by an arbitrary soft boundary. In this paper we consider the statistical description of this problem. Under the assumption that the probability density of elevations of N arbitrary points of a surface is a multivariate Gaussian distribution, we obtain an analytical expression for the scattering cross-section. This expression consists of different contributions that correspond to different terms of the quasi-slope expansion for the scattering amplitude. It is proved that under appropriate conditions the expression for the scattering cross-section corresponds either to the small-perturbation on formula or to the Kirchhoff formula. The results of numerical calculation of the angular dependence of the scattering cross-section for several values of parameters are presented for a Gaussian correlation function for surface elevations. By continuously changing the wavelength, we show the continuous transition from the results of small-perturbation theory to results corresponding to the Kirchhoff case. To estimate the accuracy of the theory, we also calculate the contribution to the scattering cross-section caused by one of the second-order (in powers of slope) terms of the quasi-slope expansion. The comparison with the experimental results for the scattering of H-polarized light by a rough metal surface shows good quantitative agreement with our calculations including grazing angles of scattering. RP TATARSKII, VI (reprint author), NOAA,ERL,WAVE PROPAGAT LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 18 Z9 18 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0959-7174 J9 WAVE RANDOM MEDIA JI Waves Random Media PD APR PY 1994 VL 4 IS 2 BP 191 EP 214 DI 10.1088/0959-7174/4/2/008 PG 24 WC Physics, Multidisciplinary SC Physics GA NH161 UT WOS:A1994NH16100008 ER PT J AU THOMSON, R AF THOMSON, R TI FUNDAMENTALS OF FRACTURE - A 1993 PROLOGUE, AND OTHER COMMENTS SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Editorial Material AB In the first part of this paper, I discuss the trends in fracture science as it is reflected in the papers given at this and the past three conferences on the fundamentals of fracture. In the second part of the paper, I present some results carried out by myself and collaborators on certain atomic aspects of fracture in a simple two-dimensional hexagonal lattice, i.e. the dislocation emission criterion, the non-local shift in the emission criterion caused by the shielding of dislocations already present, and the structure and some properties of the interfacial crack. RP THOMSON, R (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 9 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 31 PY 1994 VL 176 IS 1-2 BP 1 EP 7 DI 10.1016/0921-5093(94)90952-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ND321 UT WOS:A1994ND32100004 ER PT J AU WIEDERHORN, SM FIELDS, BA HOCKEY, BJ AF WIEDERHORN, SM FIELDS, BA HOCKEY, BJ TI FRACTURE OF SILICON-NITRIDE AND SILICON-CARBIDE AT ELEVATED-TEMPERATURES SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID DAMAGE-ENHANCED CREEP; MICROSTRUCTURE; ACCUMULATION; MECHANISMS; CERAMICS; BEHAVIOR; TENSILE; GROWTH AB High temperature fracture of structural ceramics often results from creep and creep-related processes. Creep cavitation in particular plays an important role in the failure process, resulting in crack nucleation and crack growth prior to failure. Equations modelling cavitation and crack growth mechanisms are consistent with the Monkman-Grant behavior observed for structural ceramics. Both the mechanism of fracture and the mode of crack growth are affected by the test geometry. In fleuxure, cracks tend to remain stable because of stress relaxation near the tensile surface of test specimens. In tensile specimens, stress relaxation due to cavity formation occurs in the vicinity of crack tips. Intermittent crack growth results, in which the density of cavities at the crack tip has to reach a critical level for the occurrence of crack motion. Crack growth occurs by microcrack nucleation and linkage with the dominant crack. RP WIEDERHORN, SM (reprint author), NIST, GAITHERSBURG, MD 20899 USA. NR 34 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 31 PY 1994 VL 176 IS 1-2 BP 51 EP 60 DI 10.1016/0921-5093(94)90958-X PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ND321 UT WOS:A1994ND32100010 ER PT J AU MASUDAJINDO, K ZHOU, SJ THOMSON, R CARLSSON, AE AF MASUDAJINDO, K ZHOU, SJ THOMSON, R CARLSSON, AE TI ATOMIC THEORY OF FRACTURE OF CRYSTALLINE MATERIALS - CLEAVAGE AND DISLOCATION EMISSION CRITERIA SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 36th Yamada Conference/International Conference on Fundamentals of Fracture CY MAY 31-JUN 04, 1993 CL URABANDAI, JAPAN SP YAMADA SCI FDN AB Using the lattice Green function approach, we study the crack-dislocation effects in the fracture of crystalline materials. Firstly, we calculate the Green function for the defective lattice, with dislocation and crack, by solving the Dyson equation. After the lattice Green functions have been determined, the relaxation problem for the reconstituted bonds in the cohesive zone is solved. The external force F with tensile and shear components is applied, as a pair of forces, to the atoms at the center of the crack. In this calculation the dislocation emission is chosen to be on a cleavage plane as well as on a glide plane of the two-dimensional lattice (hexagonal and graphite lattices). We compare the cleavage and dislocation emission criteria of the atomistic simulation with those of linear elasticity theory. C1 WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130. NIST,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 14 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 31 PY 1994 VL 176 IS 1-2 BP 255 EP 261 DI 10.1016/0921-5093(94)90983-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ND321 UT WOS:A1994ND32100035 ER PT J AU TONEY, MF HOWARD, JN RICHER, J BORGES, GL GORDON, JG MELROY, OR WIESLER, DG YEE, D SORENSEN, LB AF TONEY, MF HOWARD, JN RICHER, J BORGES, GL GORDON, JG MELROY, OR WIESLER, DG YEE, D SORENSEN, LB TI VOLTAGE-DEPENDENT ORDERING OF WATER-MOLECULES AT AN ELECTRODE-ELECTROLYTE INTERFACE SO NATURE LA English DT Article ID X-RAY-DIFFRACTION; DYNAMICS; SILVER; ADSORPTION; SURFACE; SIMULATION; LAYER; FACE AB THE arrangement of water molecules at charged, aqueous interfaces is an important question in electrochemistry, geochemistry and biology. Theoretical studies1-11 suggest that the molecules become arranged in several layers adjacent to a solid interface. with densities similar to that in the bulk, and that the molecules in the first layer are reoriented from oxygen-up to oxygen-down as the electrode charge changes from negative to positive. Few of these predictions have been verified experimentally12-16, however. Using X-ray scattering, we have measured the water density profile perpendicular to a silver (111) surface at two applied voltages. We find that the water molecules are ordered in layers extending about three molecular diameters from the electrode, and that the spacing between the electrode and first water layer indicates an oxygen-up (oxygen-down) average orientation for negative (positive) charge. Contrary to current models, however, we find that the first layer has a far greater density than that in bulk water. This implies that the hydrogen-bonding network is disrupted in this layer, and that the properties of the water in the layer are likely to be very different from those in the bulk. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV WASHINGTON,DEPT PHYS FM15,SEATTLE,WA 98195. RP TONEY, MF (reprint author), IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120, USA. NR 25 TC 369 Z9 372 U1 7 U2 72 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 31 PY 1994 VL 368 IS 6470 BP 444 EP 446 DI 10.1038/368444a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ND120 UT WOS:A1994ND12000059 ER PT J AU JAMES, PL HECK, KL AF JAMES, PL HECK, KL TI THE EFFECTS OF HABITAT COMPLEXITY AND LIGHT-INTENSITY ON AMBUSH PREDATION WITHIN A SIMULATED SEAGRASS HABITAT SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE CARIDEAN SHRIMP; PREDATOR-PREY INTERACTION; SEAGRASS; SEAHORSE ID LEPOMIS-MACROCHIRUS; LARGEMOUTH BASS; PREY SELECTION; FISH PREDATION; ABUNDANCE; MEADOWS; BEHAVIOR; SIZE; CONSEQUENCES; VEGETATION AB Laboratory studies were used to evaluate the effects of varying structural complexity (at densities of 0, 747, 1494, 2250 and 3032 blades/m2 artificial seagrass) and light intensity (0, 1.67, 76.28 muEin/m2/sec) on the foraging behavior and success rate of an ambush predator, the lined seahorse (Hippocampus erectus Perry). In the presence of artificial seagrass, seahorses used ''sit and wait'' foraging behavior, but in the absence of structure, seahorses actively pursued prey. Even the highest seagrass densities did not significantly reduce seahorse captures of their skrimp [Hippolyte zostericola (Smith)] prey, in contrast to the reduced capture rates often reported for actively foraging fish predators in dense vegetation. However, capture rates were significantly reduced at low light levels, even though seahorses were able to capture small numbers of shrimp in 0 light treatments. We conclude that variation in structural complexity appears to have little effect on the foraging success of this visual ''sit and wait'' predator, while variation in light level produces significant shifts in capture rates. C1 UNIV SO ALABAMA,MARINE ENVIRONM SCI CONSORTIUM,POB 369,DAUPHIN ISL,AL 36528. NOAA,FLORIDA KEYS NATL MARINE SANCTUARY,MARATHON,FL 33043. NR 56 TC 111 Z9 112 U1 2 U2 36 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD MAR 29 PY 1994 VL 176 IS 2 BP 187 EP 200 PG 14 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA NE436 UT WOS:A1994NE43600003 ER PT J AU HOBBIE, EK BAUER, BJ HAN, CC AF HOBBIE, EK BAUER, BJ HAN, CC TI FRACTAL GROWTH DURING EARLY-STAGE SPINODAL DECOMPOSITION IN A HYDROGEN-BONDED POLYMER BLEND SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOUBLE CRITICAL-POINT; MIXTURES; DYNAMICS; THERMODYNAMICS; FLUCTUATIONS; AGGREGATION; SCATTERING; VISCOSITY; MODELS AB Small-angle neutron scattering has been used to study phase separation in a polymer blend made miscible by a dilute, random distribution of hydrogen bonds between the two components. In the one-phase region, scattering below a well-defined wave vector q(c) remains weak as the critical point is approached. During the early stages of spinodal decomposition, the formation of domains of a characteristic size R(t) greater-than-or-equal-to 1/q(c) is apparent as a peak in the time-dependent structure factor, which scales as q-2.40 independent of quench depth, raising interesting questions about the morphology of early-stage spinodal decomposition in these mixtures. RP HOBBIE, EK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Hobbie, Erik/C-8269-2013 NR 38 TC 20 Z9 20 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 MAR 21 PY 1994 VL 72 IS 12 BP 1830 EP 1833 DI 10.1103/PhysRevLett.72.1830 PG 4 WC Physics, Multidisciplinary SC Physics GA NB622 UT WOS:A1994NB62200014 ER PT J AU KRASNOPOLSKY, VM BREAKER, LC AF KRASNOPOLSKY, VM BREAKER, LC TI THE PROBLEM OF AVHRR IMAGE NAVIGATION REVISITED SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID ORBITAL ELEMENTS; ARGOS AB In this study, Earth location errors in AVHRR satellite data and methods for their correction are examined with particular application to oceanic regions far removed from ground control. A general correction procedure, using landmarks or Ground Control Points (GCPs) and taking into account landmark uncertainties, is presented. Correction functions are derived as expansions for any complete basis. Operationally-available estimates of Earth location are used as a first-guess in developing the correction procedure. In particular, polynomial expansions are used to represent the correction functions which provide the basis for renavigating the satellite data. The coefficients of the polynomial expansions are obtained using the method of least-squares. The stability of the correction procedure with respect to local errors in navigation, (i.e. within a scene) and bow to select the correct order of the correction polynomials are examined. Uncertainty in extrapolating navigation corrections over remote regions is examined and quantified. The importance of landmark uncertainty in degrading renavigation accuracy is also addressed. Several parameters are introduced to optimize the choice of GCPs and their distributions. The procedures which are developed are then applied to simulated and actual AVHRR imagery. Finally, the impact of local errors in navigation, which most likely arise from rapid variations in spacecraft attitude, on renavigation accuracy is emphasized and one possible solution proposed. C1 NOAA,NATL WEATHER SERV,NATL METEOROL CTR,WASHINGTON,DC 20233. RP KRASNOPOLSKY, VM (reprint author), GEN SCI CORP,6100 CHEVY CHASE DR,LAUREL,MD 20707, USA. NR 22 TC 22 Z9 23 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAR 20 PY 1994 VL 15 IS 5 BP 979 EP 1008 PG 30 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA NH660 UT WOS:A1994NH66000003 ER PT J AU EILES, TM DEVORET, MH MARTINIS, JM AF EILES, TM DEVORET, MH MARTINIS, JM TI COULOMB-BLOCKADE OF ANDREEV REFLECTION IN THE NSN SINGLE-ELECTRON TRANSISTOR SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 10th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-10) CY MAY 31-JUN 04, 1993 CL NEWPORT, RI SP USA, RES OFF, NATL SCI FDN, USN, OFF NAVAL RES, SUNY BUFFALO, DEPT PHYS & ASTRON, BROWN UNIV, CTR ADV MAT RES ID SMALL TUNNEL-JUNCTIONS AB We have measured at low temperatures the current through a submicrometer superconducting island connected to normal-metal leads by ultrasmall tunnel junctions. At low bias voltages, the current changes from being e-periodic in the applied gate charge to 2e-periodic. We interpret this 2e-periodic current as a manifestation of a sequence of Andreev reflection events which transports two electrons at a time across the island. This behavior is clear evidence that there is a difference in total energy between ground states of an even or odd number of electrons. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. CEA,SERV PHYS ETAT CONDENSE,F-91190 GIF SUR YVETTE,FRANCE. RP EILES, TM (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 20 PY 1994 VL 305 IS 1-3 BP 536 EP 540 DI 10.1016/0039-6028(94)90949-0 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ND674 UT WOS:A1994ND67400100 ER PT J AU NOVELLI, PC MASARIE, KA TANS, PP LANG, PM AF NOVELLI, PC MASARIE, KA TANS, PP LANG, PM TI RECENT CHANGES IN ATMOSPHERIC CARBON-MONOXIDE SO SCIENCE LA English DT Article ID EARTHS ATMOSPHERE; DIOXIDE; INCREASE; METHANE; TRENDS AB Measurements of carbon monoxide (CO) in air samples collected from 27 locations between 71 degrees N and 41 degrees S show that atmospheric levels of this gas have decreased worldwide over the past 2 to 5 years. During this period, CO decreased at nearly a constant rate in the high northern latitudes. In contrast, in the tropics an abrupt decrease occurred beginning at the end of 1991. In the Northern Hemisphere, CO decreased at a spatially and temporally averaged rate of 7.3 (+/- 0.9) parts per billion per year (6.1 percent per year) from June 1990 to June 1993, whereas in the Southern Hemisphere, CO decreased 4.2 (+/- 0.5) parts per billion per year (7.0 percent per year). This recent change is opposite a long-term trend of a 1 to 2 percent per year increase inferred from measurements made in the Northern Hemisphere during the past 30 years. C1 NOAA,ENVIRONM RES LAB,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP NOVELLI, PC (reprint author), UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 26 TC 130 Z9 136 U1 0 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 18 PY 1994 VL 263 IS 5153 BP 1587 EP 1590 DI 10.1126/science.263.5153.1587 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NB673 UT WOS:A1994NB67300023 PM 17744786 ER PT J AU SALIT, ML GUENTHER, FR KRAMER, GW GRIESMEYER, JM AF SALIT, ML GUENTHER, FR KRAMER, GW GRIESMEYER, JM TI INTEGRATING AUTOMATED SYSTEMS WITH MODULAR ARCHITECTURE SO ANALYTICAL CHEMISTRY LA English DT Article C1 SANDIA NATL LABS,CTR INTELLIGENT SYST & ROBOT,DIV INTELLIGENT MACHINE SYST,TECH STAFF,ALBUQUERQUE,NM 87185. RP SALIT, ML (reprint author), NIST,DIV INORGAN ANALYT RES,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 6 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 15 PY 1994 VL 66 IS 6 BP A361 EP A367 PG 7 WC Chemistry, Analytical SC Chemistry GA NB214 UT WOS:A1994NB21400004 ER PT J AU TODOROV, PG HUBBELL, JH AF TODOROV, PG HUBBELL, JH TI ON THE EPSTEIN-HUBBELL GENERALIZED ELLIPTIC-TYPE INTEGRAL SO APPLIED MATHEMATICS AND COMPUTATION LA English DT Article AB We give a simple method for obtaining the power expansion and a basic representation by means of the Gauss hypergeometric function in K4 of the Epstein-Hubbell generalized elliptic-type integral (1). C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP TODOROV, PG (reprint author), PAISSII HILENDARSKI UNIV,DEPT MATH,BU-4000 PLOVDIV,BULGARIA. NR 10 TC 16 Z9 16 U1 1 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0096-3003 J9 APPL MATH COMPUT JI Appl. Math. Comput. PD MAR 15 PY 1994 VL 61 IS 2-3 BP 157 EP 161 DI 10.1016/0096-3003(94)90045-0 PG 5 WC Mathematics, Applied SC Mathematics GA NN197 UT WOS:A1994NN19700004 ER PT J AU BAKER, DN BLAKE, JB CALLIS, LB CUMMINGS, JR HOVESTADT, D KANEKAL, S KLECKER, B MEWALDT, RA ZWICKL, RD AF BAKER, DN BLAKE, JB CALLIS, LB CUMMINGS, JR HOVESTADT, D KANEKAL, S KLECKER, B MEWALDT, RA ZWICKL, RD TI RELATIVISTIC ELECTRON ACCELERATION AND DECAY TIME SCALES IN THE INNER AND OUTER RADIATION BELTS - SAMPEX SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PROTONS AB High-energy electrons have been measured systematically in a low-altitude (520 x 675 km), nearly polar (inclination = 82-degrees) orbit by sensitive instruments onboard the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX). Count rate channels with electron energy thresholds ranging from 0.4 MeV to 3.5 MeV in three different instruments have been used to examine relativistic electron variations as a function of L-shell parameter and time. A long run of essentially continuous data (July 1992 - July 1993) shows substantial acceleration of energetic electrons throughout much of the magnetosphere on rapid time scales. This acceleration appears to be due to solar wind velocity enhancements and is surprisingly large in that the radiation belt ''slot'' region often is filled temporarily and electron fluxes are strongly enhanced even at very low L-values (L approximately 2). A superposed epoch analysis shows that electron fluxes rise rapidly for 2.5 less than or similar L less than or similar 5. These increases occur on a time scale of order 1-2 days and are most abrupt for L-values near 3. The temporal decay rate of the fluxes is dependent on energy and L-value and may be described by J = Ke-t/to with t(O) almost-equal-to 5-10 days. Thus, these results suggest that the Earth's magnetosphere is a cosmic electron accelerator of substantial strength and efficiency. C1 AEROSP CORP,EL SEGUNDO,CA 90245. NASA,LANGLEY RES CTR,HAMPTON,VA 23681. CALTECH,PASADENA,CA 91125. MAX PLANCK INST EXTRATERR PHYS,GARCHING,GERMANY. NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP BAKER, DN (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 690,GREENBELT,MD 20771, USA. NR 12 TC 157 Z9 162 U1 0 U2 4 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 MAR 15 PY 1994 VL 21 IS 6 BP 409 EP 412 DI 10.1029/93GL03532 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NC446 UT WOS:A1994NC44600004 ER PT J AU HOFMANN, DJ OLTMANS, SJ LATHROP, JA HARRIS, JM VOMEL, H AF HOFMANN, DJ OLTMANS, SJ LATHROP, JA HARRIS, JM VOMEL, H TI RECORD LOW OZONE AT THE SOUTH-POLE IN THE SPRING OF 1993 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEPLETION AB On October 12, 1993, a balloon-borne ozone detector recorded a total ozone value of 91+/-5 Dobson Units (DU) at the US. Amsudsen-Scott Station at the south pole. This is the lowest value of total ozone ever recorded anywhere, 13% below the previous low of 105 DU at the south pole m October of 1992 [Hofmann and Oltmans, 1993]. A region with a thickness of 5 km, fmm 14 to 19 km, was totally devoid of ozone as compared to only about half this thickness for the ozone void in 1992. Sub-100 DU total ozone values were observed on several soundings during 1993 whereas the 105 DU value was observed on only one occasion in 1992. The vertical profile of ozone indicates that the main reason for the record low ozone values in 1993 was an approximately 1 lan upward extension of the ozone hole caused by unusual ozone loss in the 18-23 km region. Temperatures in this region were unusually low in September and October. Thus, the extension of the ozone hole may have been the result of the prolonged presence of polar stratospheric clouds st 18-23 km combined with the continued presence of sulfate aerosol from the Pinatubo eruption and, finally, in chlorine levels. This scenario resulted in elevated ozone loss in a region where the ozone loss process is normally not saturated. RP HOFMANN, DJ (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 8 TC 44 Z9 44 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 MAR 15 PY 1994 VL 21 IS 6 BP 421 EP 424 DI 10.1029/94GL00309 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NC446 UT WOS:A1994NC44600007 ER PT J AU BAKWIN, PS TANS, PP NOVELLI, PC AF BAKWIN, PS TANS, PP NOVELLI, PC TI CARBON-MONOXIDE BUDGET IN THE NORTHERN-HEMISPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BARROW; ALASKA AB To improve urban air quality the major industrialized nations of the West took steps during the 1970s and 1980s to reduce carbon monoxide (CO) emissions from automobiles and other industrial sources. Overall, CO/CO2 emission ratios from the mix of fossil fuel combustion sources have been reduced by about half during 1976-1990. Also, the tropospheric abundance of hydroxyl radical (OH), which is the main sink for CO, is proposed to have increased globally by about 1.0+/-0.8% yr-1 [Prinn et al., 1992]. We use a simple two-box model to examine the impact of shrinking emissions and increasing, OH on the global abundance of CO. We find that these factors contribute about equally in reducing CO levels in the Northern Hemisphere troposphere by about l.8+/-0.8 ppb yr-l on average. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP BAKWIN, PS (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 19 TC 36 Z9 37 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 MAR 15 PY 1994 VL 21 IS 6 BP 433 EP 436 DI 10.1029/94GL00006 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NC446 UT WOS:A1994NC44600010 ER PT J AU HICKERNELL, RK CHRISTENSEN, DH PELLEGRINO, JG WANG, J LEBURTON, JP AF HICKERNELL, RK CHRISTENSEN, DH PELLEGRINO, JG WANG, J LEBURTON, JP TI DETERMINATION OF THE COMPLEX REFRACTIVE-INDEX OF INDIVIDUAL QUANTUM-WELLS FROM DISTRIBUTED REFLECTANCE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAAS; ALXGA1-XAS AB We investigate the measurement of the complex refractive index of individual quantum wells by reflectance spectroscopy. Placing the wells at half-wavelength spacing to cause resonant feedback produces an order-of-magnitude increase in measurement sensitivity over that of nonresonant structures. Quantum well dispersive and absorptive effects on reflectance can be differentiated in certain spectral regions. Experimental data confirm a theoretical model of refractive index and absorption for quantum wells of GaAs in Al0.2Ga0.8As in the region of the well band gap. C1 NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899. UNIV ILLINOIS,ENGN RES CTR COMPOUND SEMICOND MICROELECTR,DEPT ELECT & COMP ENGN,URBANA,IL 61801. RP HICKERNELL, RK (reprint author), NATL INST STAND & TECHNOL,OPT ELECTR METR GRP,BOULDER,CO 80303, USA. NR 13 TC 5 Z9 5 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 MAR 15 PY 1994 VL 75 IS 6 BP 3056 EP 3059 DI 10.1063/1.356153 PG 4 WC Physics, Applied SC Physics GA NB413 UT WOS:A1994NB41300049 ER PT J AU KING, DS SAUDER, DG CASASSA, MP AF KING, DS SAUDER, DG CASASSA, MP TI CLUSTER EFFECTS IN O-3/H2O PHOTOCHEMISTRY - DYNAMICS OF THE O+H2O-]2OH REACTION PHOTOINITIATED IN THE O-3-CENTER-DOT-H2O DIMER SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARTLEY BAND PHOTODISSOCIATION; ABINITIO POTENTIAL SURFACES; ENERGY; OZONE; STATE; SPECTROSCOPY; COMPLEXES; DISSOCIATION; BEAM; DISTRIBUTIONS AB The dynamics of the 266 nm photoinitiated reaction of O-16(3) and (H2O)-O-18 were studied using O-16(3).(H2O)-O-18 van der Waals dimers to orient the initial reagents. In the absence of perturbations, the geometry of the O-16(3).(H2O)-O-18 dimer is such that 266 mm photolysis of cluster-bound ozone initiates glancing O + H2O trajectories, with a 3 Angstrom impact parameter. Laser induced fluorescence probes show that 81+/-7% (2 sigma) of the ''new''-(OH)-O-16 and essentially all of the ''old''-(OH)-O-18 products were formed with v=O, with a slight preference for the II(A') Lambda doublets, and average rotational energies of 900+/-130 and 760+/-80 cm(-1), respectively. Approximately 19% of the ''new''-(OH)-O-16 products form with v=1 and average rotational energy of 930+/-210 cm(-1). No significant OH scattering anisotropy or other vector correlations were observed. Sub-Doppler resolution experiments showed average kinetic energies for new-(OH)-O-16(v=0) products about 19% higher than for old-(OH)-O-18(v=0) products in the same rotational levels; increasing from values of about 500 cm(-1) at low rotational levels, to about 1500 cm(-1) at the highest rotational levels populated. Similar OH internal and kinetic energies were observed when the clusters were photolyzed at 281.5 nm. These dimer results are very different from those observed for the bimolecular O(D-1)+H2O-->2OH reaction, photoinitiated in gas phase mixtures of O-16(3) and (H2O)-O-18. The gas phase O(D-1)+H2O-->2OH reaction produces OH with pronounced recoil anisotropy, these OH products carry far more internal energy than seen in the cluster products, and there is greater disparity between the internal energies of the gas phase (OH)-O-16 and (OH)-O-18 products. Evidently, cooperative effects in the cluster environment result in a significant change in reaction path. C1 HOOD COLL,DEPT CHEM,FREDERICK,MD 21701. RP KING, DS (reprint author), NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 48 TC 25 Z9 25 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1994 VL 100 IS 6 BP 4200 EP 4210 DI 10.1063/1.466304 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NA918 UT WOS:A1994NA91800017 ER PT J AU WANG, DW LIU, AK PENG, CY MEINDL, EA AF WANG, DW LIU, AK PENG, CY MEINDL, EA TI WAVE-CURRENT INTERACTION NEAR THE GULF-STREAM DURING THE SURFACE-WAVE DYNAMICS EXPERIMENT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID REFRACTION; AGULHAS; SPECTRA AB This paper presents a case study on the wave-current interaction near the local curvature of a Gulf Stream meander. The wave data were obtained from in situ measurements by a pitch-roll discus buoy during the Surface Wave Dynamics Experiment (SWADE) conducted off Wallops Island, Virginia, from October 1990 to March 1991. Owing to the advection of the Gulf Stream by the semidiurnal tide, the discus buoy was alternately located outside and inside the Gulf Stream. The directional wave measurements from the buoy show the changes in wave direction, wave energy, and directional spreading when waves encountered the current in the Gulf Stream meanders. A wave refraction model, using the ray-tracing method with an estimated Gulf Stream velocity field and meandering condition, was used to simulate wave refraction patterns and to estimate wave parameters at relative locations corresponding to buoy measurements. The numerical simulation shows that a focusing zone of wave rays was formed near the boundary and behind the crest of a simulated Gulf Stream meander. The focusing of wave rays causes changes in wave direction, increases in wave energy, and decreases in wave directional spreading, which are in good agreement with the results from the buoy measurements. C1 NASA,GODDARD SPACE FLIGHT CTR,SCI SYST & APPLICAT INC,GREENBELT,MD 20771. NATL DATA BUOY CTR,BAY ST LOUIS,MS. NASA,GODDARD SPACE FLIGHT CTR,OCEANS & ICE BRANCH,GREENBELT,MD 20771. RP WANG, DW (reprint author), COMP SCI CORP,BLDG 3203,BAY ST LOUIS,MS 39529, USA. NR 28 TC 10 Z9 11 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1994 VL 99 IS C3 BP 5065 EP 5079 DI 10.1029/93JC02714 PG 15 WC Oceanography SC Oceanography GA NC605 UT WOS:A1994NC60500005 ER PT J AU EMERY, WJ YU, YY WICK, GA AF EMERY, WJ YU, YY WICK, GA TI CORRECTING INFRARED SATELLITE ESTIMATES OF SEA-SURFACE TEMPERATURE FOR ATMOSPHERIC WATER-VAPOR ATTENUATION SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SKIN AB A new satellite sea surface temperature (SST) algorithm is developed that uses nearly coincident measurements from the microwave special sensor microwave imager (SSM/I) to correct for atmospheric moisture attenuation of the infrared signal from the advanced very high resolution radiometer (AVHRR). This new SST algorithm is applied to AVHRR imagery from the South Pacific and Norwegian seas, which are then compared with simultaneous in situ (ship based) measurements of both skin and bulk SST. In addition, an SST algorithm using a quadratic product of the difference between the two AVHRR thermal infrared channels is compared with the in situ measurements. While the quadratic formulation provides a considerable improvement over the older cross product (CPSST) and multichannel (MCSST) algorithms, the SSM/I corrected SST (called the water vapor or WVSST) shows overall smaller errors when compared to both the skin and bulk in situ SST observations. Applied to individual AVHRR images, the WVSST reveals an SST difference pattern (CPSST-WVSST) similar in shape to the water vapor structure while the CPSST-quadratic SST difference appears unrelated in pattern to the nearly coincident water vapor pattern. An application of the WVSST to week-long composites of global area coverage (GAC) AVHRR data demonstrates again the manner in which the WVSST corrects the AVHRR for atmospheric moisture attenuation. By comparison the quadratic SST method underestimates the SST corrections in the lower latitudes and overestimates the SST in the higher latitudes. Correlations between the AVHRR thermal channel differences and the SSM/I water vapor demonstrate the inability of the channel difference to represent water vapor in the midlatitude and high latitudes during summer. Compared against drifting buoy data the WVSST and the quadratic SST both exhibit the same general behavior with relatively small differences with the buoy temperatures. C1 UNIV HAMBURG,INST METEOROL,W-2000 HAMBURG 13,GERMANY. NATL WEATHER SERV,CTR CLIMATE ANAL,WASHINGTON,DC. RP EMERY, WJ (reprint author), UNIV COLORADO,COLORADO CTR ASTRODYNAM RES,BOULDER,CO 80309, USA. RI Yu, Yunyue/F-5636-2010; OI Emery, William/0000-0002-7598-9082 NR 17 TC 61 Z9 66 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1994 VL 99 IS C3 BP 5219 EP 5236 DI 10.1029/93JC03215 PG 18 WC Oceanography SC Oceanography GA NC605 UT WOS:A1994NC60500014 ER PT J AU ZIEGLER, CL MACGORMAN, DR AF ZIEGLER, CL MACGORMAN, DR TI OBSERVED LIGHTNING MORPHOLOGY RELATIVE TO MODELED SPACE-CHARGE AND ELECTRIC-FIELD DISTRIBUTIONS IN A TORNADIC STORM SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID THUNDERSTORM ELECTRIFICATION; MOUNTAIN THUNDERSTORM; HAIL GROWTH; THUNDERCLOUDS; DOPPLER AB This study uses a kinematic numerical cloud model that includes electrification and lightning discharge processes to investigate hypotheses concerning intracloud lightning flash rates in the Binger, Oklahoma, tornadic storm of 22 May 1981. MacGorman et al. have observed that intracloud (IC) flash rates in this storm's mesocyclone region peak when overall storm intensity is greatest and cloud-to-ground flash rates are low. They hypothesize that precipitation interactions involved in reflectivity growth at the 7-9-km level of the updraft are involved in precipitation charging and electrification. They also hypothesize that the intense convection in the mesocyclone region elevates the lower negative charge of the storm closer to upper positive charge, thereby enhancing IC flash rates. These hypotheses are tested by examining the charge and electric field distributions and charging rates produced by the kinematic model for the Binger storm. The model produces maximum electric field and net space charge magnitudes of around 200 kV m-1 and 1 nC m-3 in runs where the threshold for activating simulated lightning discharges was set at 200 kV m-1. The noninductive mechanism, driven by charge separation during rebounding collisions between ice particles and riming graupel, generally dominates the inductive mechanism in the model. Computed precipitation charging rates of up to -5 x 10(-11) C m-3 s-1 are partially compensated by cloud particle charging from discharges in middle levels of the updraft. Simulated discharges add positive charge to cloud particles in the main negative precipitation charge region and negative charge to cloud particles in the upper positive precipitation charge region. The principal effect of lightning in the model is not to neutralize the charge on individual particles, but to partially mask the net charge carried by precipitation. The simulated discharges occur at a rate of 12 min-1, comparable to the peak observed IC flash rate of 13 min-1 within 10 km of the mesocyclone. The model results also suggest that lightning, combined with subsequent particle motions, creates new regions of charge comparable to those created by particle collisions. RP ZIEGLER, CL (reprint author), NOAA,NATL SEVERE STORMS LAB,DIV STORMSCALE RES & APPLICAT,NORMAN,OK 73069, USA. NR 39 TC 53 Z9 67 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 15 PY 1994 VL 51 IS 6 BP 833 EP 851 DI 10.1175/1520-0469(1994)051<0833:OLMRTM>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ND285 UT WOS:A1994ND28500003 ER PT J AU WHITAKER, JS DAVIS, CA AF WHITAKER, JS DAVIS, CA TI CYCLOGENESIS IN A SATURATED ENVIRONMENT SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MOIST BAROCLINIC INSTABILITY; SMALL STABILITY; B CYCLOGENESIS; FRONTOGENESIS; CONVECTION; MODELS; FLOW; FRONTS AB The dynamics of baroclinic wave growth in a saturated environment is examined using linear and nonlinear models employing a parameterization of latent heat release that assumes all rising air is saturated, and saturation equivalent potential temperature is conserved on ascent. Piecewise potential vorticity (PV) diagnostics are used to interpret the results. When the stability to vertical displacements in saturated air is allowed to increase with height, as it must in an atmosphere with a constant, positive lapse rate of potential temperature, the growth rates of the most unstable modes of the Eady problem grow only marginally faster than the modes of the dry problem. The vertical variation of moist static stability produces a gradient of moist potential vorticity in the rising air, eliminating the shortwave cutoff present in the dry Eady problem. The destabilization of the short waves is shown to be associated with the interaction between surface potential temperature anomalies and diabatically generated lower-tropospheric potential vorticity anomalies. Nonlinear primitive equation simulations, starting from normal-mode initial conditions, show that while the dry wave grows at nearly the linear growth rate until maximum amplitude is reached, the moist wave grows significantly faster than the linear growth rate at finite amplitude. This enhanced growth is associated with the rapid amplification of a mesoscale PV anomaly generated by latent heat release at the warm front. The rapid amplification of the surface cyclone results from the superposition of the circulation associated with this mesoscale PV anomaly upon the circulation associated with the surface and upper boundary potential temperature anomalies. Additional integrations with finite-amplitude initial conditions more typical of atmospheric conditions exhibit similar behavior. It is suggested that many of the rapid cyclogenesis events that occur as upper-tropospheric PV anomalies cross the east coasts of continents may arise from the rapid generation of PV anomalies by condensational heating in the moist maritime lower troposphere. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP WHITAKER, JS (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,NOAA,CAMPUS BOX 449,BOULDER,CO 80309, USA. NR 33 TC 46 Z9 47 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 15 PY 1994 VL 51 IS 6 BP 889 EP 907 DI 10.1175/1520-0469(1994)051<0889:CIASE>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ND285 UT WOS:A1994ND28500006 ER PT J AU STROSCIO, JA PIERCE, DT AF STROSCIO, JA PIERCE, DT TI SCALING OF DIFFUSION-MEDIATED ISLAND GROWTH IN IRON-ON-IRON HOMOEPITAXY SO PHYSICAL REVIEW B LA English DT Note ID THIN-FILMS; NUCLEATION; SI(001); SI AB An analysis of the island size and separation distributions of Fe islands, observed in the initial stages of growth in the homoepitaxy of Fe on Fe(001) whiskers, shows scaling properties recently predicted in nucleation and growth theories. A critical size of one atom, where islands greater than the critical size undergo irreversible nucleation, is supported by the measured scaling functions for the Fe on Fe system in the temperature range of 20-250-degrees-C. RP STROSCIO, JA (reprint author), NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899, USA. NR 22 TC 248 Z9 252 U1 0 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAR 15 PY 1994 VL 49 IS 12 BP 8522 EP 8525 DI 10.1103/PhysRevB.49.8522 PG 4 WC Physics, Condensed Matter SC Physics GA NG116 UT WOS:A1994NG11600084 ER PT J AU GAYLE, FW TACK, WT SWANSON, G HEUBAUM, FH PICKENS, JR AF GAYLE, FW TACK, WT SWANSON, G HEUBAUM, FH PICKENS, JR TI COMPOSITION AND ANISOTROPY IN AL-CU-LI-AG-MG-ZR ALLOYS SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article C1 MARTIN MARIETTA ASTRONAUT GRP,DENVER,CO 80201. MARTIN MARIETTA CORP,BALTIMORE,MD 21227. RP GAYLE, FW (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 18 TC 18 Z9 20 U1 3 U2 4 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 MAR 15 PY 1994 VL 30 IS 6 BP 761 EP 766 DI 10.1016/0956-716X(94)90195-3 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA MT536 UT WOS:A1994MT53600016 ER PT J AU JARUGA, P ZASTAWNY, TH SKOKOWSKI, J DIZDAROGLU, M OLINSKI, R AF JARUGA, P ZASTAWNY, TH SKOKOWSKI, J DIZDAROGLU, M OLINSKI, R TI OXIDATIVE DNA-BASE DAMAGE AND ANTIOXIDANT ENZYME-ACTIVITIES IN HUMAN LUNG-CANCER SO FEBS LETTERS LA English DT Article DE OXIDATIVE DNA DAMAGE; HYDROXYL RADICAL; MUTATION; MODIFIED BASE; ANTIOXIDANT ENZYME ID MAMMALIAN CHROMATIN; HYDROGEN-PEROXIDE; FREE-RADICALS; HUMAN-CELLS AB We have investigated levels of antioxidant enzymes and free radical-induced DNA base modifications in human cancerous lung tissues and in their cancer-free surrounding tissues. Various DNA base lesions in chromatin of lung tissues were measured by gas chromatography-mass spectrometry. Activities of superoxide dismutase, catalase and glutathione peroxidase were also measured in lung tissues. Higher levels of DNA lesions were observed in cancerous tissues than in cancer-free surrounding tissues. Antioxidant enzyme levels were lower in cancerous tissues. The results indicate an association between decreased activities of antioxidant enzymes and increased levels of DNA lesions in cancerous tissues. Higher levels of DNA lesions suggest that free radical reactions may be increased in malignant tumor cells. C1 MED SCH BYDGOSZCZ,DEPT CLIN BIOCHEM,PL-20899 BYDGOSZCZ,POLAND. NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. RI Olinski, Ryszard/E-9607-2014; Jaruga, Pawel/M-4378-2015 NR 37 TC 179 Z9 185 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD MAR 14 PY 1994 VL 341 IS 1 BP 59 EP 64 DI 10.1016/0014-5793(94)80240-8 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA NB189 UT WOS:A1994NB18900013 PM 8137923 ER PT J AU STEPHENS, JA GREENE, CH AF STEPHENS, JA GREENE, CH TI QUANTUM-DEFECT DESCRIPTION OF H-3 RYDBERG STATE DYNAMICS SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC EMISSION-SPECTRUM; TRIATOMIC HYDROGEN; PERPENDICULAR BANDS; TRANSITIONS; SURFACES; SERIES; D-3 AB We develop a multichannel quantum defect formulation to describe the collision of a Rydberg or continuum electron with a vibrating and rotating polyatomic ion. We formulate a full rovibronic frame transformation which accounts simultaneously for vibrationally and rotationally inelastic collisions (preionization) and l uncoupling. Interactions among degenerate Rydberg series, arising from Jahn-Teller distortions of molecular geometry, play an important role in the formulation. An application to the 1s(2)3sA1' --> 1S2epsilonpA2'', epsilonpE' Rydberg photoabsorption spectrum of H-3 accounts for many of its observed features. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP STEPHENS, JA (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 26 TC 33 Z9 33 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 14 PY 1994 VL 72 IS 11 BP 1624 EP 1627 DI 10.1103/PhysRevLett.72.1624 PG 4 WC Physics, Multidisciplinary SC Physics GA NA492 UT WOS:A1994NA49200013 ER PT J AU LINDSAY, JA KLIMAS, DM AF LINDSAY, JA KLIMAS, DM TI LIABILITY FOR CONTAMINATED SEDIMENTS - IMPLICATIONS FOR DREDGING PERMITS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,BOSTON,MA. NOAA,SAN FRANCISCO,CA 94105. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 1 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401908 ER PT J AU FRIEND, DG AF FRIEND, DG TI STANDARD REFERENCE DATABASES FOR THE THERMOPHYSICAL PROPERTIES OF FLUIDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 4 EP CHAS PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401358 ER PT J AU HOFFMAN, DK ORTIZ, C HUNSTON, DL MCDONOUGH, W AF HOFFMAN, DK ORTIZ, C HUNSTON, DL MCDONOUGH, W TI THE CHEMISTRY OF TOUGHENED EPOXY-RESINS VIA PREFORMED DISPERSIONS OF ACRYLIC ELASTOMERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 DOW CHEM CO USA,CENT RES & DEV,MIDLAND,MI 48674. 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 MAR 13 PY 1994 VL 207 BP 4 EP PMSE PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501463 ER PT J AU ORTIZ, C HUNSTON, DL MCDONOUGH, W HOFFMAN, D AF ORTIZ, C HUNSTON, DL MCDONOUGH, W HOFFMAN, D TI THE EFFECT OF CONCENTRATION AND PARTICLE-SIZE ON THE TOUGHNESS OF EPOXIES MODIFIED WITH DISPERSED ACRYLIC ELASTOMERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. DOW CHEM CO USA,MIDLAND,MI 48674. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 5 EP PMSE PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501464 ER PT J AU HAMMOUDA, B AF HAMMOUDA, B TI SANS FROM POLYMERS - USEFULNESS OF THE RPA SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKLYN POLYTECH UNIV,DEPT CHEM,BROOKLYN,NY 11201. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 6 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501037 ER PT J AU HAN, CC AF HAN, CC TI SHEAR RATE DEPENDENCE OF THE CRITICAL-DYNAMICS IN POLYMER MIXTURES 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 MAR 13 PY 1994 VL 207 BP 7 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501038 ER PT J AU CHASE, MW AF CHASE, MW TI STANDARD REFERENCE DATA PROGRAM AND COPYRIGHT EXPERIENCES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,STAND REFERENCE DATA PROGRAM,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 9 EP CINF PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401363 ER PT J AU LIGGETT, WS INN, KGW AF LIGGETT, WS INN, KGW TI EXPERIMENTAL METHODS FOR IMPROVING SAMPLING PROTOCOLS 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 MAR 13 PY 1994 VL 207 BP 10 EP CEI PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95502020 ER PT J AU LONG, ER WOLFE, DA LINSE, JC AF LONG, ER WOLFE, DA LINSE, JC TI SPATIAL EXTENT OF SEDIMENT TOXICITY IN SELECTED BAYS AND ESTUARIES OF THE USA SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,ORCA,SEATTLE,WA 98115. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 16 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401923 ER PT J AU TSANG, W WALKER, JA AF TSANG, W WALKER, JA TI SINGLE-PULSE SHOCK-TUBE STUDIES ON THE UNIMOLECULAR DECOMPOSITION OF LARGE UNSATURATED MOLECULES - TRANS-1-PHENYL-1-PENTENE 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 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 20 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402257 ER PT J AU BURGESS, D TSANG, W ZACHARIAH, MR WESTMORELAND, PR AF BURGESS, D TSANG, W ZACHARIAH, MR WESTMORELAND, PR TI FLUORINATED HYDROCARBON FLAME SUPPRESSION CHEMISTRY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. UNIV MASSACHUSETTS,DEPT CHEM ENGN,AMHERST,MA 01003. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 21 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402258 ER PT J AU SHADDIX, CR HARRINGTON, JE SMYTH, KC AF SHADDIX, CR HARRINGTON, JE SMYTH, KC TI ENHANCED SOOT FORMATION IN FLICKERING DIFFUSION FLAMES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 1 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 MAR 13 PY 1994 VL 207 BP 23 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402260 ER PT J AU KRANBUEHL, DE VERDIER, PH AF KRANBUEHL, DE VERDIER, PH TI EFFECTS OF VARIABLE EXCLUDED-VOLUME ON THE RELAXATION BEHAVIOR OF OFF-LATTICE POLYMER-CHAINS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 COLL WILLIAM & MARY,DEPT CHEM,WILLIAMSBURG,VA 23187. 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 MAR 13 PY 1994 VL 207 BP 30 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501061 ER PT J AU VERDIER, PH KRANBUEHL, DE AF VERDIER, PH KRANBUEHL, DE TI PHASE-SEPARATION IN POLYMER BLENDS - OFF-LATTICE SIMULATION STUDIES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. COLL WILLIAM & MARY,WILLIAMSBURG,VA 23187. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 31 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501062 ER PT J AU MACDONALD, DD LONG, ER CALDER, FD AF MACDONALD, DD LONG, ER CALDER, FD TI AN EVALUATION OF THE PREDICTABILITY OF TOXICITY BY SEDIMENT QUALITY GUIDELINES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 MACDONALD ENVIRONM SCI LTD,LADYSMITH V0R 2E0,BC,CANADA. NOAA,ORCA,SEATTLE,WA 98115. FLORIDA DEPT ENVIRONM PROTECT,TALLAHASSEE,FL 32399. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 33 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401940 ER PT J AU DOWNING, RG AF DOWNING, RG TI ANALYTICAL MEASUREMENTS USING A POLYCAPILLARY NEUTRON FOCUSING LENS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,NUCL METHODS GRP,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 1 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 MAR 13 PY 1994 VL 207 BP 58 EP NUCL PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500051 ER PT J AU ANTONUCCI, JM SKRTIC, D EANES, ED AF ANTONUCCI, JM SKRTIC, D EANES, ED TI POLYMERIC CALCIUM-PHOSPHATE COMPOSITES WITH REMINERALIZATION POTENTIAL SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NIDR,BONE RES BRANCH,BETHESDA,MD 20892. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 60 EP BTEC PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501803 ER PT J AU VETTER, TW PRATT, KW TURK, GC BECK, CM BUTLER, TA AF VETTER, TW PRATT, KW TURK, GC BECK, CM BUTLER, TA TI USING INSTRUMENTAL TECHNIQUES TO INCREASE THE ACCURACY OF CLASSICAL-ANALYSIS IN THE GRAVIMETRIC-DETERMINATION OF SULFATE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,INORGAN ANALYT RES DIV,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 66 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95400342 ER PT J AU STANSBURY, JW LIU, DW KIM, SI AF STANSBURY, JW LIU, DW KIM, SI TI POLYMER-SUPPORTED CATALYSTS FOR SYNTHESIS OF CYCLOPOLYMERIZABLE MONOMERS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMER,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 84 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501115 ER PT J AU LEONE, SR AF LEONE, SR TI STATE-RESOLVED DYNAMICS OF ION COLLISIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 94 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500734 ER PT J AU SCHANTZ, MM WISE, SA BOLT, DL AF SCHANTZ, MM WISE, SA BOLT, DL TI USE OF PERDEUTERATED AND C-13 LABELED POLYCYCLIC AROMATIC-HYDROCARBONS (PAHS) AS INTERNAL STANDARDS FOR THE DETERMINATION OF PAHS IN NATURAL MATRIX STANDARD REFERENCE MATERIALS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV ANALYT RES,GAITHERSBURG,MD 20899. CAMBRIDGE ISOTOPE LABS,WOBURN,MA 01801. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 97 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402004 ER PT J AU EADIE, BJ ROBBINS, JA BELL, GL MEYERS, PA AF EADIE, BJ ROBBINS, JA BELL, GL MEYERS, PA TI PROBING PARTICLE PROCESSES IN THE GREAT-LAKES USING SEDIMENT TRAPS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. UNIV MICHIGAN,DEPT GEOL,ANN ARBOR,MI 48109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 121 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402028 ER PT J AU JOHNSON, WE PLIMMER, JR KROLL, RB PAIT, AS AF JOHNSON, WE PLIMMER, JR KROLL, RB PAIT, AS TI CHESAPEAKE BAY - A DECADE OF PESTICIDE MONITORING SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USDA,BELTSVILLE,MD 20705. ABC LABS,COLUMBIA,MO 65205. DEPT ENVIRONM,BALTIMORE,MD 21224. NOAA,ROCKVILLE,MD 20852. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 126 EP AGRO PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95400199 ER PT J AU JAFVERT, CT VANHOOF, P AF JAFVERT, CT VANHOOF, P TI A QSAR FOR SOLUBILIZATION OF NONPOLAR COMPOUNDS BY NONIONIC SURFACTANT MICELLES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 PURDUE UNIV,SCH CIVIL ENGN,W LAFAYETTE,IN 47907. NOAA,GREAT LAKES ENVIRONM LAB,ANN ARBOR,MI 48105. RI Jafvert, Chad/D-9551-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 140 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402047 ER PT J AU AGARWALA, JP TODD, P PELLEGRINO, JJ AF AGARWALA, JP TODD, P PELLEGRINO, JJ TI BIOMIMETIC IMMOBILIZED LIQUID MEMBRANE SEPARATOR FOR AQUEOUS SOLUTES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 151 EP BIOT PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95400550 ER PT J AU HAMMOUDA, B LIN, CC BALSARA, NP AF HAMMOUDA, B LIN, CC BALSARA, NP TI KINETICS OF PHASE-SEPARATION OF HOMOPOLYMER AND BLOCK-COPOLYMER MIXTURES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BROOKLYN POLYTECH UNIV,DEPT CHEM,BROOKLYN,NY 11201. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 152 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501184 ER PT J AU HUANG, SX FISCHER, DA GLAND, JL AF HUANG, SX FISCHER, DA GLAND, JL TI IN-SITU KINETIC-STUDIES OF ANILINE ON NICKEL SINGLE-CRYSTAL SURFACES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 152 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95401603 ER PT J AU CAMPAGNOLA, PJ VORSA, V BUCHENAU, HK LINEBERGER, WC AF CAMPAGNOLA, PJ VORSA, V BUCHENAU, HK LINEBERGER, WC TI PHOTOCHEMISTRY AND DYNAMICS OF (CO2)N- CLUSTERS - PHOTOPRODUCTION OF CO3- SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,DEPT CHEM & BIOCHEM,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 155 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500794 ER PT J AU MACDONALD, RC NEMECEKMARSHALL, M FALL, R AF MACDONALD, RC NEMECEKMARSHALL, M FALL, R TI INVESTIGATIONS OF METHANOL EMISSION FROM PLANTS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 161 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402068 ER PT J AU SIEVERS, RE VELTKAMP, PR BARKLEY, RM HANSEN, KJ AF SIEVERS, RE VELTKAMP, PR BARKLEY, RM HANSEN, KJ TI ORGANIC-COMPOUNDS IN AEROSOL-PARTICLES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 185 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95402092 ER PT J AU CABEZAS, H COLE, KD AF CABEZAS, H COLE, KD TI ELECTROCHROMATOGRAPHIC PURIFICATION OF PROTEINS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 232 EP BIOT PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY954 UT WOS:A1994MY95400630 ER PT J AU KATO, S FROST, MJ KISIEL, KR BIERBAUM, VM LEONE, SR AF KATO, S FROST, MJ KISIEL, KR BIERBAUM, VM LEONE, SR TI VIBRATIONALLY SPECIFICITY IN STATE-SELECTED ION-MOLECULE REACTIONS OF N2+(V=0,1,2) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 250 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500886 ER PT J AU LEACH, GW YOKOYAMA, K KIM, JB LINEBERGER, WC AF LEACH, GW YOKOYAMA, K KIM, JB LINEBERGER, WC TI HIGH-RESOLUTION PHOTODETACHMENT SPECTROSCOPY OF C3H2- SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 262 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500898 ER PT J AU WILLIAMS, RM LEONE, SR AF WILLIAMS, RM LEONE, SR TI INFRARED VIBRATIONAL EMISSION-SPECTROSCOPY OF NAPHTHALENE FOLLOWING UV LASER EXCITATION SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 300 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500936 ER PT J AU HUANG, SX FISCHER, DA GLAND, JL AF HUANG, SX FISCHER, DA GLAND, JL TI THE CORRELATION OF THE STRUCTURE AND REACTIVITY OF ANILINE ON THE NI(111) SURFACE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 321 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500957 ER PT J AU LINEBERGER, WC PAPANIKOLAS, JM CAMPAGNOLA, PJ VORSA, V NADAL, M BUCHENAU, HK AF LINEBERGER, WC PAPANIKOLAS, JM CAMPAGNOLA, PJ VORSA, V NADAL, M BUCHENAU, HK TI TIME-RESOLVED DYNAMICS IN LARGE MOLECULAR CLUSTER IONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,DEPT CHEM,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 358 EP PHYS PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95500994 ER PT J AU BALSARA, NP HAMMOUDA, B AF BALSARA, NP HAMMOUDA, B TI EFFECT OF SHEAR ON CONCENTRATED BLOCK-COPOLYMER SOLUTIONS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 POLYTECH INST NEW YORK,DEPT CHEM ENGN,BROOKLYN,NY 11201. 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 MAR 13 PY 1994 VL 207 BP 359 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501390 ER PT J AU JACKSON, CL MUTHUKUMAR, M BARNES, KA MORRISON, FA MAYS, JW NAKATANI, AI HAN, CC AF JACKSON, CL MUTHUKUMAR, M BARNES, KA MORRISON, FA MAYS, JW NAKATANI, AI HAN, CC TI SHEAR-EXCITED MORPHOLOGICAL STATES IN A TRIBLOCK COPOLYMER SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MASSACHUSETTS,DEPT POLYMER SCI & ENGN,AMHERST,MA 01003. MICHIGAN TECHNOL UNIV,DEPT CHEM ENGN,HOUGHTON,MI 49931. UNIV ALABAMA,DEPT CHEM,UNIVERSITY,AL 35486. US DEPT COMMERCE,NATL INST STAND & TECHNOL,TECHNOL ADM,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RI Morrison, Faith/G-2996-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 360 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501391 ER PT J AU RABEONY, M DOZIER, WD PEIFFER, DG LIN, MY THIYAGARAJAN, P BEHAL, SK DISKO, M AF RABEONY, M DOZIER, WD PEIFFER, DG LIN, MY THIYAGARAJAN, P BEHAL, SK DISKO, M TI SCATTERING BY STRETCHED GRAFT-COPOLYMERS - FROM 2-POINT TO BUTTERFLY PATTERNS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. ARGONNE NATL LAB,INTENSE PULSE NEUTRON SOURCE,ARGONNE,IL 60439. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 13 PY 1994 VL 207 BP 411 EP POLY PN 2 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA MY955 UT WOS:A1994MY95501442 ER PT J AU BROWN, JM ZINK, LR EVENSON, KM AF BROWN, JM ZINK, LR EVENSON, KM TI A MEASUREMENT OF THE J=2[-1 FINE-STRUCTURE INTERVAL FOR SI-28 AND SI-29 IN THE GROUND P-3 STATE SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC DATA; LINE, IDENTIFICATION; ISM, ATOMS; RADIO LINES, ISM ID LASER-MAGNETIC-RESONANCE; ATOMIC CARBON; GJ-FACTORS AB We report the first observation of the far-infrared laser magnetic resonance spectrum associated with the J = 2 <-- 1 fine-structure interval of Si-28 and Si-29 in the 3P ground state. In Si-28 this separation is 4378.3280(2) GHz, and for Si-29 it is 4378.3306(6) GHz. The magnetic hyperfine parameter A2 has also been determined for Si-29 apparently for the first time. The value obtained corresponds to a value for the electronic expectation value [r-3]l of 1.626 x 10(31) m-3. Zero-field transition frequencies for the hyperfine components of the J = 2 <-- 1 transition in Si-29 are determined and will aid in their identification in interstellar sources. C1 NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303. RP BROWN, JM (reprint author), PHYS CHEM LAB,S PARKS RD,OXFORD OX1 3QZ,ENGLAND. NR 18 TC 11 Z9 11 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 MAR 10 PY 1994 VL 423 IS 2 BP L151 EP L154 DI 10.1086/187259 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NA097 UT WOS:A1994NA09700020 ER PT J AU EMBLEY, RW FEELY, RA LUPTON, JE AF EMBLEY, RW FEELY, RA LUPTON, JE TI INTRODUCTION TO SPECIAL SECTION ON VOLCANIC AND HYDROTHERMAL PROCESSES ON THE SOUTHERN JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SULFIDE DEPOSITS; WATER-COLUMN; PLUMES; VENTS; DIFFUSE; FIELDS C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. RP EMBLEY, RW (reprint author), NOAA, DIV OCEAN ENVIRONM RES, HATFIELD MARINE SCI CTR, 2115 SE OSU DR, NEWPORT, OR 97365 USA. NR 53 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4735 EP 4740 DI 10.1029/93JB03217 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700031 ER PT J AU EMBLEY, RW CHADWICK, WW AF EMBLEY, RW CHADWICK, WW TI VOLCANIC AND HYDROTHERMAL PROCESSES ASSOCIATED WITH A RECENT PHASE OF SEA-FLOOR SPREADING AT THE NORTHERN CLEFT SEGMENT - JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-OCEAN RIDGE; SEA MARC-I; AXIAL VOLCANO; RIFT-VALLEY; LAVA FLOWS; ZONES; VARIABILITY; ERUPTION; CENTERS AB The northern portion of the Cleft segment, which is the southernmost segment of the Juan de Fuca Ridge, is the site of a seafloor spreading episode during the mid-1980s that was originally discovered by the occurrence of anomalous hydrothermal bursts (megaplumes) and later documented by seafloor mapping of new pillow mounds (NPM) that were erupted. Several field seasons of investigations using sidescan sonar, a deep-tow camera system, and the submersible Alvin reveal that about 30 km of the ridge crest is hydrothermally active and/or has experienced recent volcanic and tectonic activity associated with this episode. The most intense hydrothermal activity within this area and all the known high-temperature vents lie along a fissure from which a young sheet flow (YSF) erupted. Extinct chimneys located within 100-200 m on either side of the fissure system represent an older (>100 years) and probably less intense, hydrothermal regime. The bathymetry and the morphology of the YSF suggest that this eruption occurred over a 1-2 km section of the fissure system that forms its eastern boundary and that it flowed to the south. Fields of lava pillars concentrated at the margins of the YSF where lava probably formed when the lava stagnated near the edges of the flow. A comparison of sidescan data sets collected in 1982 and 1987 implies that the YSF was erupted at least 7 months prior to the NPM, consistent with analysis of bottom photographs that suggests that the eruptions of the YSF and NPM were only separated by a few years. The low hydrothermal flux over the NPM relative to the YSF suggests a rapidly cooled underlying heat source beneath the former. We propose that the NPM were erupted from a dike or dikes injected laterally to the north from a magma body lying beneath the YSF. Recent evidence of a decrease in the intensity of the overlying hydrothermal plumes suggests that the system is continuing to cool down. C1 OREGON STATE UNIV, HATFIELD MARINE SCI CTR, COOPERAT INST MARINE RESOURCES, NEWPORT, OR 97365 USA. RP EMBLEY, RW (reprint author), NOAA, HATFIELD MARINE SCI CTR, OCEAN ENVIRONM RES DIV, PACIFIC MARINE ENVIRONM LAB, 2115 SE OSU DR, NEWPORT, OR 97365 USA. NR 53 TC 120 Z9 122 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4741 EP 4760 DI 10.1029/93JB02038 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700032 ER PT J AU CHADWICK, WW EMBLEY, RW AF CHADWICK, WW EMBLEY, RW TI LAVA FLOWS FROM A MID-1980S SUBMARINE ERUPTION ON THE CLEFT SEGMENT, JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; VOLCANIC RIFT ZONES; KILAUEA VOLCANO; GALAPAGOS RIFT; MAGMA; ICELAND; HAWAII; 21-DEGREES-N; VALLEY; KRAFLA AB A series of lava flows with a total volume of 0.05 km3 were erupted in the mid-1980s along 17 km of the northern Cleft segment of the Juan de Fuca Ridge. Observations from camera tows and submersible dives show that the new flows are all similar in appearance and consist entirely of pillow lava with a mixture of smooth and striated surface textures, suggesting a relatively uniform eruption rate approaching 1 m3/s at point source vents. The flows vary in size from small patches to large steep-sided ridges and were probably erupted from a dike intruded along the ridge axis because they are aligned along a linear fissure/graben system. Observations at north Cleft show that the physical appearance of new flows changes more rapidly than previously realized and that earlier qualitative dating of young lavas based on sediment cover and glassy surface texture were probably overestimates by an order of magnitude. Sediment accumulation on the lavas is quite variable and locally surprisingly substantial, mainly due to hydrothermal deposits that formed while the lava flows were cooling. Biological vent communities photographed on the new flows in 1989 show that vent animals can colonize new vent sites rapidly but that warm water was still venting only in a few places. Nonvent animals are much slower to colonize the new flows and rates of colonization observed at north Cleft may be useful for making improved age estimates of young (<10 years) lava flows elsewhere. The north Cleft eruption represents about 2% of the estimated average annual volcanic output along the global mid-ocean ridge, implying that many other submarine eruptions are occurring undetected. C1 NOAA, HATFIELD MARINE SCI CTR, PACIFIC MARINE ENVIRONM LAB, NEWPORT, OR 97365 USA. RP CHADWICK, WW (reprint author), OREGON STATE UNIV, HATFIELD MARINE SCI CTR, COOPERAT INST MARINE RESOURCES STUDIES, NEWPORT, OR 97365 USA. NR 56 TC 76 Z9 76 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4761 EP 4776 DI 10.1029/93JB02041 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700033 ER PT J AU MCDONALD, MA WEBB, SC HILDEBRAND, JA CORNUELLE, BD FOX, CG AF MCDONALD, MA WEBB, SC HILDEBRAND, JA CORNUELLE, BD FOX, CG TI SEISMIC STRUCTURE AND ANISOTROPY OF THE JUAN-DE-FUCA RIDGE AT 45-DEGREES-N SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID UPPER OCEANIC-CRUST; EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SPREAD PROFILES; DEEP; REFRACTION; EVOLUTION; POROSITY AB A seismic refraction experiment was conducted with air guns and ocean bottom seismometers on the Juan de Fuca Ridge at 45-degrees-N, at the northern Cleft segment and at the overlapping rift zone between the Cleft and Vance segments. These data determine the average velocity structure of the upper crust and map the thickness variability of the shallow low-velocity layer, which we interpret as the extrusive volcanic layer. The experiment is unique because a large number of travel times were measured along ray paths oriented at all azimuths within a small (20 km by 35 km) area. These travel times provide evidence for compressional velocity anisotropy in the upper several hundred meters of oceanic crust, presumed to be caused by ridge-parallel fracturing. Compressional velocities are 3.35 km/s in the ridge strike direction and 2.25 km/s across strike. Travel time residuals are simultaneously inverted for anisotropy as well as lateral thickness variations in the low-velocity layer. Extrusive layer thickness ranges from approximately 200 m to 550 m with an average of 350 m. The zone of the thinnest low-velocity layer is within the northern Cleft segment axial valley, in a region of significant hydrothermal activity. Layer thickness variability is greatest near the Cleft-Vance overlapping rift zone, where changes of 300 m occur over as little as several kilometers laterally. These low-velocity layer thickness changes may correspond to fault block rotations in an episodic spreading system, where the low side of each fault block accumulates more extrusive volcanics. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, HATFIELD MARINE SCI CTR, NEWPORT, OR 97365 USA. RP MCDONALD, MA (reprint author), UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, LA JOLLA, CA 92093 USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 46 TC 42 Z9 42 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4857 EP 4873 DI 10.1029/93JB02801 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700038 ER PT J AU STEVENSON, JM HILDEBRAND, JA ZUMBERGE, MA FOX, CG AF STEVENSON, JM HILDEBRAND, JA ZUMBERGE, MA FOX, CG TI AN OCEAN-BOTTOM GRAVITY STUDY OF THE SOUTHERN JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SEA MARC-I; CRUSTAL STRUCTURE; SEISMIC STRUCTURE; 3-DIMENSIONAL ANALYSIS; SPREADING CENTERS; MIDOCEAN RIDGE; ANOMALIES; POROSITY AB We use seafloor and sea surface gravity data to model density structure along the southern Juan de Fuca Ridge. We determine the average density of the shallow oceanic crust at the ridge using seafloor gravity measurements and then use these data in conjunction with sea surface gravity observations to construct density structure models. Of 63 seafloor gravity measurements obtained, 42 observations were distributed over the 3-km left-lateral overlapping rift zone (ORZ), located at latitude 45-degrees-03'N, and separating the Juan de Fuca ridge into the Cleft and Vance segments. A 21-measurement seafloor gravity transect was made perpendicular to the ridge strike at latitude 44-degrees-52'N, a region of linear ridge geometry on the Cleft segment. These seafloor gravity measurements, which are sensitive to shallow crustal density variations, were augmented by roughly 800 km of sea surface gravity measurements. Using a bathymetry-Bouguer anomaly analysis of the seafloor gravity data, we determined the average density of the shallow (roughly upper 2 km) oceanic crust at these two locations to be 2630 kg m-3 +/- 50 kg m-3. Within the uncertainties of the density determinations, there is no difference between the average shallow oceanic crustal density at the linear Cleft segment and at the Cleft-Vance ORZ. Using the seafloor measurements, we modeled the study area's underlying density to provide constraints on its fine-scale structure. Localized porosity of up to 17% within the upper 500 m of oceanic crust (layer 2A) provide a possible explanation for the observed gravity anomalies at the Cleft segment. Two-dimensional density models of the crust underlying the linear Cleft segment (44-degrees-52'N) show that no deep source is required to explain the topographical asymmetry observed between the east and west sides of the ridge axis. For the Cleft-Vance ORZ, three-dimensional modeling suggests low-density material between the rifts, in agreement with thickened layer 2A from seismic observations. In contrast, layer 2A variations do not explain the low density inferred at the northern end of the Cleft segment since seismic observations suggest a thin layer 2A. The magmatic activity recently observed in this region may have a distinct, deeper source. C1 UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, LA JOLLA, CA 92093 USA. NOAA, HATFIELD MARINE SCI CTR, PACIFIC MARINE ENVIRONM LAB, DIV MARINE RESOURCES RES, NEWPORT, OR USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 68 TC 18 Z9 18 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4875 EP 4888 DI 10.1029/93JB02076 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700039 ER PT J AU BAKER, ET AF BAKER, ET TI A 6-YEAR TIME-SERIES OF HYDROTHERMAL PLUMES OVER THE CLEFT SEGMENT OF THE JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SOUTHERN JUAN; VENT FIELD; SMOKER PLUMES; TEMPERATURE; SEAFLOOR; HEAT; EARTHQUAKES; TECTONICS AB The causal links between magmatic/tectonic processes and hydrothermal venting along the mid-ocean ridge axis will be difficult to discern without broadband observations of the temporal variability of hydrothermal activity. I report here on temporal variability in the intensity and distribution of chronic and event plumes generated by continuous and episodic hydrothermal discharge at two vent fields on the Cleft segment of the Juan de Fuca Ridge. Hydrothermal temperature (DELTAtheta) and light attenuation (DELTAc) anomalies were comprehensively mapped between 1 and 4 times per year during nine cruises from 1986 to 1991. Intensity of DELTAtheta and DELTAc in the chronic plume overlying the north Cleft vent field showed more variability between years than within a given year. Both DELTAtheta and DELTAc were exceptionally high in 1986, fell to moderate levels during 1988 to 1990, and declined to minimum values in 1991. The chronic plume over the south Cleft vent field varied similarly. Superimposed on the chronic plumes were brief and intense releases of hydrothermal fluid that created event plumes distinguishable by their symmetry and exceptional rise height. Event plumes at the north Cleft field ranged from the 1986 megaplume, with a rise height exceeding 1000 m, to smaller events in 1987 and 1989 with rise heights of approximately 400 m. Chronic hydrothermal heat (660 +/- 277 (1sigma) MW) and mass (204 +/- 86 (1sigma) g s-1) fluxes from the north Cleft field were determined by assuming these fluxes were equivalent to the long-term net advection of a mean cross-section of the vertically integrated DELTAtheta and DELTAc in the plume. This 6-year history of hydrothermal plumes indicates that episodic discharge has been an important component of the recent hydrothermal flux and that the aggregate heat and mass fluxes declined significantly, though not consistently, between 1986 and 1991. RP BAKER, ET (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 51 TC 62 Z9 63 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4889 EP 4904 DI 10.1029/93JB01030 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700040 ER PT J AU MASSOTH, GJ BAKER, ET LUPTON, JE FEELY, RA BUTTERFIELD, DA VONDAMM, KL ROE, KK LEBON, GT AF MASSOTH, GJ BAKER, ET LUPTON, JE FEELY, RA BUTTERFIELD, DA VONDAMM, KL ROE, KK LEBON, GT TI TEMPORAL AND SPATIAL VARIABILITY OF HYDROTHERMAL MANGANESE AND IRON AT CLEFT SEGMENT, JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SOUTHERN JUAN; PLUMES; SEAWATER; CHEMISTRY; 21-DEGREES-N; FLUIDS; OCEAN; WATER AB A unique data set for hydrothermal Mn and Fe was collected at Cleft segment on the Juan de Fuca Ridge between 1983 and 1991. The data set includes observations of focused and diffuse venting fluids and neutrally buoyant plumes formed by chronic and episodic venting. Manganese/heat and iron/heat ratios for plumes from the north end of the Cleft segment were combined with independently determined estimates of plume heat flux to yield annually averaged chronic venting fluxes for Mn of 0.36 +/- 0.17 mol s-1 and for Fe of 0.61 +/- 0.34 mol s-1. Over 6 years of plume measurements at North Cleft segment, observed episodic hydrothermal discharge accounted for approximately 15% of the total vented Mn and approximately 35% of vented Fe. The chronic fluxes for Mn and Fe at a second venting center located at the south end of the Cleft segment were estimated to be approximately equal to the fluxes at North Cleft segment. Chronic plumes at North Cleft segment are mixtures of focused and diffuse discharge that contribute heat, Mn, and Fe in variable proportions. Similar examination of South Cleft segment data strongly suggests the presence of an as yet unobserved venting source relatively depleted in Mn and Fe but contributing substantially to the overall heat. Temporal and spatial variations in the concentrations of Mn and Fe and in Mn/heat and Fe/heat ratios for focused seafloor vents were difficult to resolve within complex chronic plumes. Manganese/heat and iron/heat ratios of megaplumes suggest they may have derived from reservoirs of diffuse fluids while smaller event plumes may have formed by different processes and have properties similar to chronic plumes. The accurate assessment of segment-scale hydrothermal fluxes of Mn and Fe requires coordinated measurements of representative seafloor sources and the neutrally buoyant plume that integrates all seafloor discharge. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, NEWPORT, OR 97365 USA. UNIV NEW HAMPSHIRE, DEPT EARTH SCI, DURHAM, NH 03824 USA. RP MASSOTH, GJ (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Wright, Dawn/A-4518-2011; Butterfield, David/H-3815-2016 OI Wright, Dawn/0000-0002-2997-7611; Butterfield, David/0000-0002-1595-9279 NR 66 TC 55 Z9 56 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4905 EP 4923 DI 10.1029/93JB02799 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700041 ER PT J AU TREFRY, JH BUTTERFIELD, DB METZ, S MASSOTH, GJ TROCINE, RP FEELY, RA AF TREFRY, JH BUTTERFIELD, DB METZ, S MASSOTH, GJ TROCINE, RP FEELY, RA TI TRACE-METALS IN HYDROTHERMAL SOLUTIONS FROM CLEFT SEGMENT ON THE SOUTHERN JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; ORE SOLUTION CHEMISTRY; SULFIDE DEPOSITS; HOT SPRINGS; FLUIDS; CONSTRAINTS; 21-DEGREES-N; SEAWATER; CHIMNEYS; BASALT AB Concentrations of trace metals in Fe- and Cl-rich hydrothermal solutions from the southern Juan de Fuca Ridge (SJFR) have been determined and corrected for residual precipitates formed in the sampler. Precipitate corrections for Ag, Cd, Cu, Mo, Pb, Sb, and Zn were variable, contributing an average of 20% to total solution concentrations whereas corrections for Co averaged less than 5% and essentially no corrections were required for Fe and Mn. Values for Cu, Co, and Mo in these solutions showed a strong dependence on temperature with sharp decreases in concentrations as temperatures decreased to less than 320-degrees-C. In addition, and unlike most other metals studied, all vent fluids from the SJFR were almost completely depleted in Mo relative to seawater values of about 110 nmol kg-1. In contrast to the Cu-Co-Mo group, concentrations of Ag, Cd, Sb, and Pb correlated well with those for Zn and are presumed to follow a distribution that is influenced less by temperature over the 246 to 332-degrees-C range encountered in this study and more by the combined chemical processes that control Zn levels along the transport pathway from the deep reaction zone to the vent orifice. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. RP TREFRY, JH (reprint author), FLORIDA INST TECHNOL, DEPT OCEANOG, MELBOURNE, FL 32901 USA. RI Butterfield, David/H-3815-2016; OI Butterfield, David/0000-0002-1595-9279; Trefry, John/0000-0002-8451-5524 NR 41 TC 52 Z9 52 U1 2 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4925 EP 4935 DI 10.1029/93JB02108 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700042 ER PT J AU BUTTERFIELD, DA MASSOTH, GJ AF BUTTERFIELD, DA MASSOTH, GJ TI GEOCHEMISTRY OF NORTH CLEFT SEGMENT VENT FLUIDS - TEMPORAL CHANGES IN CHLORINITY AND THEIR POSSIBLE RELATION TO RECENT VOLCANISM SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DE-FUCA RIDGE; HYDROTHERMAL ALTERATION PROCESSES; SEAWATER-BASALT INTERACTION; SEA MARC-I; THEORETICAL CONSTRAINTS; SUPERCRITICAL REGION; CHEMICAL-EXCHANGE; MIDOCEAN RIDGES; OCEANIC-CRUST; 500 BARS AB Hydrothermal vent fluids from the North Cleft segment of the Juan de Fuca Ridge between 44-degrees-54' and 45-degrees-00'N were sampled in 1988, 1990, 1991, and 1992. In 1988, chloride-depleted (relative to seawater) diffuse fluids with low dissolved metal concentrations (relative to other mid-ocean ridge (MOR) fluids) were sampled over a distance of approximately 10 km along axis. In 1990 and 1991, both high-temperature (>200-degrees-C) and diffuse vents were consistently metal- and chloride-enriched. The end-member compositions of high-temperature vents and nearby diffuse vents were very similar. There were small but significant correlated changes in diffuse and high-temperature composition from 1990 to 1991. The large-scale but temporary venting of low-chlorinity fluids over the entire North Cleft segment provides a resolution to the apparent mass imbalance implied by observations of continuous venting of chloride-enriched fluids. It is possible that a volcanic event along the North Cleft segment prior to 1987, for which there is firm geologic evidence, initially caused a boiling event which resulted in the preferential venting of vapor-enriched fluids through 1988, followed by a transition to brine-enriched fluids by 1990. High iron, low sodium, and low Sr/Ca ratios in the high-chlorinity fluids suggest that the brine phase has continued to react and approach reequilibration with an alteration mineral assemblage after the phase separation event. The absence of chloride-depleted fluids from 1990 onward, and the systematics of lithium, boron, and manganese with chloride in the high-temperature fluids from North Cleft suggest that the evolution toward lower chlorinity at Monolith vent from 1990 to 1992 is caused by progressive dilution of a brine with hydrothermal seawater. C1 UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEAN, SEATTLE, WA 98195 USA. RP BUTTERFIELD, DA (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Wright, Dawn/A-4518-2011; Butterfield, David/H-3815-2016 OI Wright, Dawn/0000-0002-2997-7611; Butterfield, David/0000-0002-1595-9279 NR 53 TC 121 Z9 126 U1 2 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4951 EP 4968 DI 10.1029/93JB02798 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700044 ER PT J AU CHIN, CS COALE, KH ELROD, VA JOHNSON, KS MASSOTH, GJ BAKER, ET AF CHIN, CS COALE, KH ELROD, VA JOHNSON, KS MASSOTH, GJ BAKER, ET TI IN-SITU OBSERVATIONS OF DISSOLVED IRON AND MANGANESE IN HYDROTHERMAL VENT PLUMES, JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; RARE-EARTH ELEMENTS; NORTHEAST PACIFIC; SOUTHERN JUAN; AXIAL VOLCANO; FLOW-ANALYSIS; DEEP-SEA; SEAWATER; OCEAN AB In situ measurements of dissolved manganese and total dissolved iron were conducted in hydrothermal plumes over the Juan de Fuca Ridge using a submersible chemical analyzer (Scanner). The Scanner was deployed as part of a CTD/transmissometer/rosette instrument package on both tow-yos and vertical casts during the VENTS Leg I cruise in 1989. Dissolved manganese and total dissolved iron concentrations, along with temperature and light attenuation anomalies, were determined over the ridge crest every 5 s. Discrete samples for laboratory analyses of dissolved iron II, total dissolved iron II+III and manganese were also collected. Metal to heat ratios (Me:Q) measured in situ were extremely variable in one steady state plume, while an event plume had constant Me:Q. Uniform values of Mn:Q in the event plume demonstrate that Mn behaves conservatively in the near-field plume. Variability in the Mn:Q ratios in a steady state plume indicated the presence of at least two hydrothermal sources with distinct Me:Q values. A simple mixing model shows that the contribution of Mn from high Me:Q sources, with a composition characteristic of black smoker vents, varies between 1 % and 99 % within the core of the steady state plume with an average value of 55 %. On average, over 50 % of the excess heat within the plume originates from low Me:Q ratio sources, with a composition characteristic of low-temperature, diffuse flow vent fluids. Less than 4 % of the volume of hydrothermal fluids in the plume originates from black smokers. The Fe II concentrations were used to provide an estimate of plume age on a transect across the ridge axis. Plume ages were about 2.5 days on axis and > 12 days off axis. These plume ages were modeled to provide estimates of plume transport and horizontal diffusion and show excellent agreement with ages determined using Rn-222. C1 MOSS LANDING MARINE LABS, POB 450, MOSS LANDING, CA 95039 USA. NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. RI Johnson, Kenneth/F-9742-2011 OI Johnson, Kenneth/0000-0001-5513-5584 NR 73 TC 38 Z9 40 U1 0 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4969 EP 4984 DI 10.1029/93JB02036 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700045 ER PT J AU FEELY, RA MASSOTH, GJ TREFRY, JH BAKER, ET PAULSON, AJ LEBON, GT AF FEELY, RA MASSOTH, GJ TREFRY, JH BAKER, ET PAULSON, AJ LEBON, GT TI COMPOSITION AND SEDIMENTATION OF HYDROTHERMAL PLUME PARTICLES FROM NORTH CLEFT SEGMENT, JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; MID-ATLANTIC RIDGE; SOUTHERN JUAN; SULFIDE DEPOSITS; AXIAL VOLCANO; WATER-COLUMN; VENT FIELD; MANGANESE; OCEAN; CHEMISTRY AB In 1990 and 1991, particles from buoyant and neutrally buoyant hydrothermal plumes above hydrothermal vents at the North Cleft segment of the Juan de Fuca Ridge were sampled to study their changing composition and fluxes away from the vent field. In the rising buoyant plume, >75% of the P, V, Cr, and As scavenging from seawater by hydrothermal precipitates occurs in the first 50 m above the vent. Cu and Zn are most enriched in buoyant plume particles collected from the first few meters above the vent. However, the degree of enrichment decreases very rapidly with increased height above die vents due to sedimentation of the more dense Cu- and Zn-rich sulfide phases. Using the plume data, coupled with the results of our analysis of sediment trap samples, we estimated that more than 99% and 99.9%, respectively, of the total hydrothermal Fe and Mn produced at the vent field are transported beyond the vent field and dispersed in the open ocean. C1 FLORIDA INST TECHNOL, DEPT OCEANOG OCEAN ENGN & ENVIRONM SC, MELBOURNE, FL 32901 USA. RP FEELY, RA (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. OI Trefry, John/0000-0002-8451-5524 NR 65 TC 76 Z9 76 U1 0 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 4985 EP 5006 DI 10.1029/93JB02509 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700046 ER PT J AU GENDRON, JF TODD, JF FEELY, RA BAKER, ET KADKO, DC AF GENDRON, JF TODD, JF FEELY, RA BAKER, ET KADKO, DC TI EXCESS RN-222 ABOVE THE CLEFT SEGMENT OF THE JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST-PACIFIC-RISE; SUBMARINE HYDROTHERMAL SOLUTIONS; GALAPAGOS RIFT; ENDEAVOR RIDGE; VENT FIELDS; HOT SPRINGS; OCEAN; PLUMES; HEAT; CHEMISTRY AB The distributions of excess Rn-222 above the North Cleft segment of the Juan de Fuca Ridge were determined from 1988 to 1991 in order to obtain a better understanding of the temporal variability of heat flux from this ridge segment. Based on the inventories of excess Rn-222, the hydrothermal heat flux was estimated to be 2.7 +/- 1.3 GW in 1990. The large uncertainty results from errors in calculating the standing crop of Rn-222, the difficulty in determining the Rn-222 to heat ratio, and the problem of entrainment of low-temperature waters into the rising plume. The high-resolution sampling program carried out in 1990 permitted the mapping of apparent plume ages for different sections of the neutrally buoyant plume. About 3 km to the east of the ridge axis there is a sharp gradient in the apparent age of the plume, while to the west the plume appears to be younger. This plume age distribution could indicate a current flow to the northwest during the time this transect was sampled. The mean Rn-222/heat ratios for the high- and low-temperature vent fluids were 0.0017 disintegrations per minute (dpm) g-1-degrees-C-1 and 0.0044 dpm g-1-degrees-C-1, respectively. The extrapolated end-member concentrations of excess Rn-222 in low-temperature vent fluids are a factor of 6 greater than the high-temperature fluids, based on the regressions of excess Rn-222 activity and Mg concentration in North Cleft segment vent fluid samples. C1 NOAA, OFF GLOBAL PROGRAMS, SILVER SPRING, MD 20910 USA. UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. RP GENDRON, JF (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, NOAA BLDG 3, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 41 TC 16 Z9 16 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 5007 EP 5015 DI 10.1029/93JB03209 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700047 ER PT J AU KADKO, D FEELY, R MASSOTH, G AF KADKO, D FEELY, R MASSOTH, G TI SCAVENGING OF TH-234 AND PHOSPHORUS REMOVAL FROM THE HYDROTHERMAL EFFLUENT PLUME OVER THE NORTH CLEFT SEGMENT OF THE JUAN-DE-FUCA RIDGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EAST PACIFIC RISE; EARTH ELEMENT COMPOSITION; METALLIFEROUS SEDIMENTS; NAZCA PLATE; OCEAN; DISEQUILIBRIA; DISTRIBUTIONS; GEOCHEMISTRY; PARTICLES; RATES AB Dissolved and total Th-232 (t1/2 = 24.1 days) profiles were measured over the hydrothermal field located within the North Cleft segment of the Juan de Fuca Ridge. Above the hydrothermal effluent plume, which rose approximately 200 m from the seafloor, greater-than-or-equal-to 90% of the Th-234 was dissolved, and the total Th-234 activity was in equilibrium with its parent uranium. This is typical of deep water for which the residence time of dissolved Th-234 with respect to particle uptake is greater than 200 days. Within the effluent plume, however, as little as 30% of the Th-234 was in the dissolved state and the residence time of dissolved Th-234 with respect to particle uptake was then of the order of only a few weeks. The flux (J(Th)) of dissolved Th-234 to the particle phase was about 300 disintegrations per minute (dpm) cm-2 yr-1. The total Th-234 was still approximately in equilibrium with U, indicating that the residence time of the Th-234-bearing particles with respect to sinking was greater than 100 days. Particulate P, V, and As, while insignificant above the plume, attained concentrations as high as 60, 0.65, and 0.45 nmol/L within the plume. The particulate [p]/[Th-234] ratio and the Th-234 flux (J(Th)) are used to calculate a removal flux of P resulting from hydrothermal scavenging of approximately 50 mug cm-2 yr-1 or approximately 5.0 x 10(6) g p yr-1 per kilometer of active ridge crest. Similarly, 1.0 x 10(5) g km-1 of V and As are removed per year from the water column by hydrothermal scavenging over this region. Extrapolation to a global scale suggests that ridge crest scavenging removes less-than-or-equal-to 10% of these elements from the ocean. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. RP KADKO, D (reprint author), UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MAC, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. NR 29 TC 19 Z9 19 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1994 VL 99 IS B3 BP 5017 EP 5024 DI 10.1029/93JB02952 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NB207 UT WOS:A1994NB20700048 ER PT J AU HAPIOT, P PINSON, J FRANCESCH, C MHAMDI, F ROLANDO, C NETA, P AF HAPIOT, P PINSON, J FRANCESCH, C MHAMDI, F ROLANDO, C NETA, P TI OXIDATIVE DIMERIZATION OF PHENOLIC ALDEHYDES RELATED TO LIGNIN FORMATION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LINEAR SWEEP VOLTAMMETRY; ELECTRON REDOX POTENTIALS; PHENOXYL RADICALS; ELECTROCHEMICAL OXIDATION; ELECTRODIMERIZATION; MECHANISMS; REDUCTION AB The first steps of the polymerization of phenolic aldehydes (coumaraldehyde (1H), coniferaldehyde (2H), and sinapaldehyde (3H) have been examined by cyclic voltammetry and pulse radiolysis in aqueous (water/methanol mixture) and in organic solvents (acetonitrile and CH2Cl2). The mechanism involves an electron transfer of the corresponding phenolate to give the phenoxy radical which dimerizes. The values of the dimerization rate constants have been measured in water and acetonitrile (ACN) and found to be sensitive to the nature of the solvent. The standard potentials for the different phenoxyl radical/phenolate couples have been determined in the different solvents. C1 UNIV PARIS 06,ECOLE NORMALE SUPER,DEPT CHIM,CNRS,UNITE RECH 1679,F-75231 PARIS 05,FRANCE. NATL INST STAND & TECHNOL,DIV CHEM KINET & THERMODYNAM,GAITHERSBURG,MD 20889. RP HAPIOT, P (reprint author), UNIV PARIS 07,ELECTROCHIM MOLEC LAB,CNRS,UNITE RECH 438,2 PL JUSSIEU,F-75251 PARIS 05,FRANCE. RI PINSON, Jean/L-7028-2013; Rolando, Christian/E-8278-2011; Pinson, Jean/M-9116-2016 OI Rolando, Christian/0000-0002-3266-8860; NR 41 TC 11 Z9 11 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 10 PY 1994 VL 98 IS 10 BP 2641 EP 2645 DI 10.1021/j100061a022 PG 5 WC Chemistry, Physical SC Chemistry GA NA046 UT WOS:A1994NA04600022 ER PT J AU Habib, JM Seyoum, HM Bennett, LH Swartzendruber, LJ Blendell, JE AF Habib, J. M. Seyoum, H. M. Bennett, L. H. Swartzendruber, L. J. Blendell, J. E. TI STRONG FLUX PINNING EFFECTS IN BULK Y1Ba2Cu3O7-delta SO MODERN PHYSICS LETTERS B LA English DT Article AB A modification of the quench-melt-growth (QMG) method of Sawano et al. has been used to produce highly textured superconducting samples of YBa2Cu3O7-delta (123) with a high density of inclusions, a high density of parallel microcracks, and strong flux pinning persisting up to temperatures close to T-c. A selected sample has: 1) a very sharp transition width, similar or equal to 0.3 K as determined from ac susceptibility, and < 0.5 K as determined from diamagnetic shielding or trapped flux measurements; 2) a zero Meissner effect in applied fields as low as 5 Oe; 3) a high magnetic critical current sustained over a broad temperature range; and 4) wide hysteresis loops at temperatures up to 0.5 K below T-c. C1 [Bennett, L. H.; Swartzendruber, L. J.; Blendell, J. E.] NIST, Gaithersburg, MD 20899 USA. [Habib, J. M.; Seyoum, H. M.] Univ Dist Columbia, Dept Phys, Washington, DC 20008 USA. RP Habib, JM (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. FU NIH grant [GMO7677] FX Supported by NIH grant No. GMO7677. NR 15 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD MAR 10 PY 1994 VL 8 IS 6 BP 351 EP 359 DI 10.1142/S0217984994000364 PG 9 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA V25YD UT WOS:000208512400001 ER PT J AU SCHMIDT, DL COBURN, CE DEKOVEN, BM POTTER, GE MEYERS, GF FISCHER, DA AF SCHMIDT, DL COBURN, CE DEKOVEN, BM POTTER, GE MEYERS, GF FISCHER, DA TI WATER-BASED NONSTICK HYDROPHOBIC COATINGS SO NATURE LA English DT Article ID CONTACT ANGLES; ADSORPTION; SURFACE AB THERE is a considerable demand for materials that have surfaces to which other substances mill not easily stick. Coatings with these properties might be used to make surfaces non-adhesive towards soil, ice, biological foulants, graffiti and other unwanted contaminants. Here we describe a class of water-based non-stick Coatings prepared by self-assembly and immobilization of reactive polymeric surfactants(1,2). These polymer surfactants contain pendant perfluoroalkyl groups which become oriented so as to yield surfaces with very low energy. Immobilization by crosslinking increases non-stick performance and film toughness. These hard, clear coatings release adhesives and cannot bk wetted or attacked by solvents. C1 DOW CHEM CO USA,CENT RES & DEV,MAT SCI & DEV LAB,MIDLAND,MI 48667. DOW CHEM CO USA,ANALYT SCI,MICHIGAN RES & DEV,MIDLAND,MI 48667. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP SCHMIDT, DL (reprint author), DOW CHEM CO USA,CENT RES & DEV,ADV POLYMER SYST LAB,1712 BLDG,MIDLAND,MI 48674, USA. NR 26 TC 201 Z9 204 U1 5 U2 42 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 3 PY 1994 VL 368 IS 6466 BP 39 EP 41 DI 10.1038/368039a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MY569 UT WOS:A1994MY56900045 ER PT J AU BOISVERT, RF AF BOISVERT, RF TI CHARTER AND SCOPE TRANSACTIONS ON MATHEMATICAL SOFTWARE (TOMS) SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Editorial Material RP BOISVERT, RF (reprint author), NATL INST STAND & TECHNOL,DIV APPL & COMPUTAT MATH,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD MAR PY 1994 VL 20 IS 1 BP 1 EP 2 PG 2 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA NJ364 UT WOS:A1994NJ36400001 ER PT J AU JOSELL, D AF JOSELL, D TI INTERFACIAL FREE-ENERGIES FROM SUBSTRATE CURVATURE MEASUREMENTS OF THE CREEP OF MULTILAYER THIN-FILMS SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID ELASTIC-MODULI; SURFACE STRESS; PARTICLES AB The equilibrium biaxial curvature of a multilayer thin film adhering to a free standing substrate is determined when plastic flow is possible in the multilayer. The relationship found between the equilibrium biaxial curvature and the interfaces in the multilayer is modified to account for grain boundaries in the layers. Two possible experiments that utilize the resulting relationship to determine interfacial free energies are described. RP JOSELL, D (reprint author), NAT INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 40 TC 12 Z9 14 U1 0 U2 1 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 MAR PY 1994 VL 42 IS 3 BP 1031 EP 1038 DI 10.1016/0956-7151(94)90297-6 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA MY328 UT WOS:A1994MY32800042 ER PT J AU GALLOWAY, JN LEVY, H KASHIBHATLA, PS AF GALLOWAY, JN LEVY, H KASHIBHATLA, PS TI YEAR 2020 - CONSEQUENCES OF POPULATION-GROWTH AND DEVELOPMENT ON DEPOSITION OF OXIDIZED NITROGEN SO AMBIO LA English DT Article ID PHOTOCHEMICAL PRODUCTION; SEASONAL-VARIATION; GLOBAL MODEL; EMISSIONS; ACIDIFICATION; CIRCULATION; ATMOSPHERE; OZONE AB With a current world population of 5.3 billion, fossil fuel and biomass burning have already greatly increased the emission of fixed nitrogen to the global atmosphere. In 2020, with a projected population of 8.5 billion and an assumed 100% increase in per capita energy consumption relative to 1980 by the lesser developed countries, we predict an approximate 25% increase in total nitrogen deposition in the more-developed-country source regions such as North America. In addition, reactive nitrogen deposition will at least double in less-developed regions, such as SE Asia and Latin America, and will increase by more than 50% over the oceans of the Northern Hemisphere. Although we also predict significant increases in the deposition of nitrogen from fossil-fuel sources over most of the Southern Hemisphere, particularly Africa, the tropical eastern Pacific, and the southern Atlantic and Indian Oceans, biomass burning and the natural sources of nitrogen oxides (lightning and biogenic soil emissions) are also important in these regions. This increased deposition has the potential to fertilize both terrestrial and marine ecosystems, resulting in the sequestering of carbon. Increases in nitrogen deposition have also been shown not only to acidify ecosystems but also to increase emissions of nitric oxide (NO), nitrous oxide (N2O), carbonyl sulfide (COS), and carbon + sulfur (CS2) to the atmosphere and decrease methane (CH4) consumption in forest soils. We also find that the atmospheric levels of nitrogen oxides increase significantly throughout much of the Northern Hemisphere and populated regions of the Southern Hemisphere. This increase may lead to larger ozone concentrations with resulting increases in the oxidative capacity of the remote atmosphere and in its ability to absorb IR radiation. C1 NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. RP GALLOWAY, JN (reprint author), UNIV VIRGINIA,DEPT ENVIRONM SCI,CLARK HALL,CHARLOTTESVILLE,VA 22903, USA. RI Galloway, James/C-2769-2013; OI Galloway, James/0000-0001-7676-8698; Kasibhatla, Prasad/0000-0003-3562-3737 NR 29 TC 171 Z9 197 U1 2 U2 28 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0044-7447 J9 AMBIO JI Ambio PD MAR PY 1994 VL 23 IS 2 BP 120 EP 123 PG 4 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA NG514 UT WOS:A1994NG51400003 ER PT J AU PAERL, HW PRUFERTBEBOUT, LE GUO, CZ AF PAERL, HW PRUFERTBEBOUT, LE GUO, CZ TI IRON-STIMULATED N-2 FIXATION AND GROWTH IN NATURAL AND CULTURED POPULATIONS OF THE PLANKTONIC MARINE CYANOBACTERIA TRICHODESMIUM SPP SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID WATERS; LIMITATION; AVAILABILITY; MOLYBDENUM; PACIFIC; OCEAN AB In light of recent proposals that iron (Fe) availability may play an important role in controlling oceanic primary production and nutrient flux, its regulatory impact on N-2 fixation and production dynamics was investigated in the widespread and biogeochemically important diazotrophic, planktonic cyanobacteria Trichodesmium spp. Fe additions, as FeCl3 and EDTA-chelated FeCl3, enhanced N-2 fixation (nitrogenase activity), photosynthesis (CO2 fixation), and growth (chlorophyll a production) in both naturally occurring and cultured (on unenriched oligotrophic seawater) Trichodesmium populations. Maximum enhancement of these processes occurred under FeEDTA-amended conditions. On occasions, EDTA alone led to enhancement. No evidence for previously proposed molybdenum or phosphorus limitation was found. Our findings geographically extend support for Fe limitation of N-2 fixation and primary production to tropical and subtropical oligotrophic ocean waters often characterized by Trichodesmium blooms. C1 NOAA,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516. RP PAERL, HW (reprint author), UNIV N CAROLINA,INST MARINE SCI,3431 ARENDELL ST,MOREHEAD CITY,NC 28557, USA. NR 21 TC 101 Z9 104 U1 0 U2 10 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1994 VL 60 IS 3 BP 1044 EP 1047 PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA MZ137 UT WOS:A1994MZ13700044 PM 16349210 ER PT J AU VEASEY, DL LARSON, DR VEIGL, I AF VEASEY, DL LARSON, DR VEIGL, I TI WAVE-GUIDE POLARIZERS PROCESSED BY LOCALIZED PLASMA-ETCHING SO APPLIED OPTICS LA English DT Article ID GUIDE AB We develop a downstream localized plasma-etching process that permits in situ monitoring of light throughput in a semiconductor-clad channel waveguide as the semiconductor thickness is trimmed. Hydrogenated amorphous silicon films are deposited on ion-exchanged channel waveguides by plasma-enhanced chemical vapor deposition. We then employ the localized plasma-etching process to maximize accurately the extinction ratio between TE and TM polarizations propagating in the clad waveguide. We achieve polarization extinction ratios of greater than 30 dB for both TE-pass and TM-pass polarizers. C1 INTEGRIERTE OPT TECHNOL, W-6833 WAGHAUSEL KIRRLACH, GERMANY. RP VEASEY, DL (reprint author), NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 1 PY 1994 VL 33 IS 7 BP 1242 EP 1244 PG 3 WC Optics SC Optics GA NB422 UT WOS:A1994NB42200018 PM 20862145 ER PT J AU WONGNG, W FREIMAN, SW AF WONGNG, W FREIMAN, SW TI HIGH-TC SUPERCONDUCTING BI-SR-CA-CU-O GLASS-CERAMICS - A REVIEW SO APPLIED SUPERCONDUCTIVITY LA English DT Review ID 2223 PHASE FORMATION; MELT-QUENCHING METHOD; TEMPERATURE-GRADIENT; RETROGRADE DENSIFICATION; BI2SR2CACU2OX GLASS; REACTION-MECHANISM; THERMAL-STABILITY; BI-2223 PHASE; 2212 PHASE; FINE RODS AB Glass-ceramic technology provides a convenient method for forming materials into a variety of near-net shapes. This paper reviews the current status of this method for preparing bulk Bi-Sr (Pb)-Ca-Cu-O superconducting ceramics. We also include discussion of the precursor glasses, processing techniques, and reported formation mechanisms of the high T(c) phases. RP WONGNG, W (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 92 TC 17 Z9 17 U1 7 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0964-1807 J9 APPL SUPERCOND JI Appl. Supercond. PD MAR-APR PY 1994 VL 2 IS 3-4 BP 163 EP 180 DI 10.1016/0964-1807(94)90004-3 PG 18 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA NT631 UT WOS:A1994NT63100004 ER PT J AU ANTONELIS, GA MELIN, SR BUKHTIYAROV, YA AF ANTONELIS, GA MELIN, SR BUKHTIYAROV, YA TI EARLY SPRING FEEDING-HABITS OF BEARDED SEALS (ERIGNATHUS-BARBATUS) IN THE CENTRAL BERING SEA, 1981 SO ARCTIC LA English DT Article DE BEARDED SEAL; ERIGNATHUS-BARBATUS; DIET; DEMERSAL AND PELAGIC FISH; BENTHIC INVERTEBRATES; PREY SPECIES DIVERSITY AB The diet of bearded seals, Erignathus barbatus, near St. Matthew Island, Bering Sea, was studied during the early spring of 1981. Eighty-six percent of the 78 seals' stomachs examined contained fish. Other prey taxon groups, in decreasing order of their percentages of occurrence, were crabs (73%), clams (55%), snails (47%), amphipods (32%), shrimp (18%), mysids (13%), marine worms (13%) and cephalopods (4%). The most frequently occurring prey species were capelin, Mallotus villosus (82%); codfishes, Gadidae (64%); narrow snow crab, Chionoecetes opilio (63%); eelpouts, Lycodes spp. (56%); longsnout prickelback, Lumpenella longirostris (49%); nutshell clams, Nuculana sp. (42%); and moon snails, Polinices sp. (27%). Seventy-seven percent of the seals examined had consumed prey from three or more different taxon groups. We identified seven food items not previously reported as prey of the bearded seal in the Bering Sea. No differences were detected between the diets of males and females and between adults and juveniles, indicating no apparent segregation of foraging by sex or age. Bearded seals in the St. Matthew Island region of the Bering Sea forage in a manner similar to their conspecifics in other areas where fish constitute a major portion of their diet. Prey selection is probably dependent on availability, and diet may be highly diversified even within a relatively small area during a short period of time. Variety in prey consumption exemplifies the ability of the bearded seal to forage in the seasonally changing habitat associated with the advance and retreat of the ice front. C1 PACIFIC SCI RES INST MARINE FISHERIES & OCEANOG,MAGADAN 685013,RUSSIA. RP ANTONELIS, GA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,7600 SAND POINT WAY NE,BIN C15700,BLDG 4,SEATTLE,WA 98115, USA. NR 27 TC 22 Z9 23 U1 1 U2 5 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY AB T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD MAR PY 1994 VL 47 IS 1 BP 74 EP 79 PG 6 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA NF036 UT WOS:A1994NF03600009 ER PT J AU DOVE, JB SHULL, JM AF DOVE, JB SHULL, JM TI PHOTOIONIZATION OF DISK GALAXIES - AN EXPLANATION OF THE SHARP EDGES IN THE H-1 DISTRIBUTION SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INDIVIDUAL (NGC-3198); GALAXIES, ISM; GALAXIES, STRUCTURE; RADIATIVE TRANSFER; RADIO LINES, GALAXIES ID DARK MATTER; MASS-DISTRIBUTION; ROTATION CURVES; SPIRAL GALAXIES; CLOUDS; NGC-3198; EMISSION; DENSITY; MODELS; LIMITS AB We have reproduced the observed radial truncation of the H I distribution in isolated spiral galaxies with a model in which extragalactic radiation photoionizes the gaseous disk. For a galactic mass distribution model that reproduces the observed rotation curves, including dark matter in the disk and halo, the vertical structure of the gas is determined self-consistently. The ionization structure and column densities of H and He ions are computed by solving the radiation transfer equation for both continuum and lines. Our model is similar to that of Maloney, and the H I structure differs by less than 10%. The radial structure of the column density of H I is found to be more sensitive to the extragalactic radiation field than to the distribution of mass. For this reason, considerable progress can be made in determining the extragalactic flux of ionizing photons, PHI(ex), with more 21 cm observations of isolated galaxies. However, owing to the uncertainty of the radial distribution of total hydrogen at large radii, inferring the extragalactic flux by comparing the observed edges to photoionization models is somewhat subjective. We find 1 x 10(4) cm-2 s-1 less than or similar to PHI(ex) less than or similar to 5 x 10(4) cm-2 s-1, corresponding to 2.1 less than or similar to I0 less than or similar to 10.5( x 10(-23)) ergs cm-2 s-1 Hz-1 sr-1 for a nu-1 spectrum. Although somewhat higher, our inferred range of I0 is consistent with the large range of values obtained by Kulkarni & Fall from the ''proximity effect'' toward QSOs at z almost-equal-to 0.5. C1 UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP DOVE, JB (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,CAMPUS BOX 440,BOULDER,CO 80309, USA. NR 37 TC 91 Z9 93 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 MAR 1 PY 1994 VL 423 IS 1 BP 196 EP 206 DI 10.1086/173799 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MZ152 UT WOS:A1994MZ15200016 ER PT J AU PITCHFORD, ML MCMURRY, PH AF PITCHFORD, ML MCMURRY, PH TI RELATIONSHIP BETWEEN MEASURED WATER-VAPOR GROWTH AND CHEMISTRY OF ATMOSPHERIC AEROSOL FOR GRAND-CANYON, ARIZONA, IN WINTER 1990 SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Conference on Visibility and Fine Particles CY SEP 15-18, 1992 CL VIENNA, AUSTRIA DE HYGROSCOPIC AEROSOL; AEROSOL MIXTURES; RELATIVE HUMIDITY EFFECTS; PARTICLE SAMPLING; AEROSOL SIZE DISTRIBUTIONS ID RELATIVE-HUMIDITY; LOS-ANGELES; SIZE; CALIBRATION; PARTICLES; CYCLE AB Size-resolved aerosol growth measurements (growth = moist particle diameter/dry particle diameter) and chemical composition monitoring were conducted during a 3 month period in the winter of 1990 at the South Rim of Grand Canyon National Park, AZ as part of the Navajo Generating Station Visibility Study. Particle growth data are from a Tandem Differential Mobility Analyzer (TDMA). Typically for relative humidities above 75%, the TDMA-measured moist particle distribution is distinctly bimodal, indicating two aerosol fractions based on growth and providing direct evidence of an external mixture of soluble and insoluble constituents. In this study both particle fractions grew in size, thus the terms ''more hygroscopic'' and ''less hygroscopic'' were used to distinguish them. Micro-Orifice Uniform Deposit Impactors (MOUDI) collected size-segregated 24 h duration samples for subsequent analysis by XRF, ion chromatography, and by thermo-optical analysis (i.e. for carbon). A model that synthesizes growth and compositional information was developed to partition the overall volume fraction of the soluble material as determined from the MOUDI composition data, epsilon, to the two growth fractions obtained from the TDMA data (i.e. epsilon is partitioned between epsilon(m) and epsilon(l)). The model calculates epsilon(m) and epsilon(l) for each TDMA measurement as well as growth capacity of the soluble material at the measurement relative humidity, G(s), which is assumed to be the same for both growth fractions. Model results indicate that on average, the more hygroscopic particles are composed of equal volumes of soluble and insoluble materials, while the less hygroscopic fraction is dominated by insoluble material (about 85%). C1 UNIV MINNESOTA,DEPT MECH ENGN,PARTICLE TECHNOL LAB,MINNEAPOLIS,MN 55455. RP PITCHFORD, ML (reprint author), US EPA,NOAA,LAS VEGAS,NV 89193, USA. RI McMurry, Peter/A-8245-2008 OI McMurry, Peter/0000-0003-1609-5131 NR 39 TC 74 Z9 78 U1 3 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1994 VL 28 IS 5 BP 827 EP 839 DI 10.1016/1352-2310(94)90242-9 PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR215 UT WOS:A1994NR21500011 ER PT J AU MULHOLLAND, GW BRYNER, NP AF MULHOLLAND, GW BRYNER, NP TI RADIOMETRIC MODEL OF THE TRANSMISSION CELL-RECIPROCAL NEPHELOMETER SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Conference on Visibility and Fine Particles CY SEP 15-18, 1992 CL VIENNA, AUSTRIA DE ABSORPTION COEFFICIENT; AEROSOL; AGGLOMERATES; EXTINCTION COEFFICIENT; NEPHELOMETER; SCATTERING COEFFICIENT; SMOKES ID NUCLEAR WINTER; SMOKE; SCATTERING; ABSORPTION; SIZE AB A radiometric model has been developed to assess the effects of angular truncation, finite size of the detector, and angle response characteristics of the cosine sensor on the measurement of the total scattering coefficient by a transmission cell-reciprocal nephelometer. These effects are computed for monodisperse polystyrene spheres over the size range 0.02-8 mum based on Mie theory and for smoke agglomerates ranging from 10 to 10(7) primary units based on the Fisher-Burford approximation. The accuracy of the model calculations is determined by comparison with exact solutions for the case of a detector with an infinitesimal area and for a finite area detector with a diffuse scattering function. The predicted results are compared with measured results for six different sizes of monodisperse polystyrene sphere aerosols with particle diameters in the range 0.1-2.35 mum. The measurements were carried out as a function of the distance between the laser beam and detector for 1.3 and 2.7 cm diameter cosine sensors. A table of design parameters for making accurate total scattering measurements is obtained for both spheres and agglomerates. An accuracy of +/-5% was obtained for spherical particles with diameters less-than-or-equal-to 1.1 mum with our TCRN, and we estimate that similar performance would be obtained for smoke agglomerates with up to 3 x 10(3) primary spheres per agglomerate. RP MULHOLLAND, GW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 22 TC 20 Z9 20 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1994 VL 28 IS 5 BP 873 EP 887 DI 10.1016/1352-2310(94)90246-1 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR215 UT WOS:A1994NR21500015 ER PT J AU DOBBINS, RA MULHOLLAND, GW BRYNER, NP AF DOBBINS, RA MULHOLLAND, GW BRYNER, NP TI COMPARISON OF A FRACTAL SMOKE OPTICS MODEL WITH LIGHT EXTINCTION MEASUREMENTS SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Conference on Visibility and Fine Particles CY SEP 15-18, 1992 CL VIENNA, AUSTRIA DE ABSORPTION CROSS-SECTIONS; AGING (MATERIALS); CARBONACEOUS SMOKE; FRACTALS; SCATTERING CROSS-SECTIONS; SMOKE; SPECIFIC EXTINCTION ID DIFFUSION FLAME; ACETYLENE SMOKE; SOOT; SCATTERING; ABSORPTION; PARTICLES; CLUSTERS; EMISSIONS; DIMENSION; AEROSOL AB Optical cross-sections of carbonaceous aggregates (smoke) formed by combustion sources have been computed based on fractal concepts. Specific extinction depends upon the primary particle size, the structure of the aggregate as represented by the fractal dimension, the fractal prefactor, and the real and imaginary components of the refractive index of the particle material. While the fractal dimension and primary particle diameter are narrowly defined, the refractive index, to which the results are highly sensitive, are disputed. Specific extinction was measured at lambda = 450, 630 and 1000 nm in a smoke-filled chamber with an optical path length of 1.0 m that was equipped to continuously monitor both particle mass and number concentration as the smoke aged during a 90-120 min interval. The smoke was generated by the burning of crude oil in a pool fire. Specific extinction at all three values of lambda was found to be constant even though the aggregate number concentration decreases by a factor of 24 owing to cluster-cluster aggregation. The refractive indices at several wavelengths that are required to give agreement with the measured specific extinction are compared with literature values. The inadequacy of Mie theory for spheres in predicting the optical properties of soot aggregates is reiterated. C1 NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. RP DOBBINS, RA (reprint author), BROWN UNIV,DIV ENGN,PROVIDENCE,RI 02912, USA. NR 34 TC 105 Z9 110 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1994 VL 28 IS 5 BP 889 EP 897 DI 10.1016/1352-2310(94)90247-X PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR215 UT WOS:A1994NR21500016 ER PT J AU MALM, WC TRIJONIS, J SISLER, J PITCHFORD, M DENNIS, RL AF MALM, WC TRIJONIS, J SISLER, J PITCHFORD, M DENNIS, RL TI ASSESSING THE EFFECT OF SO2 EMISSION CHANGES ON VISIBILITY SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Conference on Visibility and Fine Particles CY SEP 15-18, 1992 CL VIENNA, AUSTRIA DE VISIBILITY ASSESSMENT; SO2 EMISSION REDUCTION; ACID DEPOSITION EFFECTS ID EXTINCTION; AEROSOLS AB During the 1970s the effect of acid rain on the environment became a growing concern to scientists, public policy officials, interest groups, and the general population. The United States' Congress mandated a 10-year study, National Acid Precipitation Assessment Program (NAPAP), to examine the relationship between acid rain related emissions and environmental effects including visibility. It was found that averaging over both space and time (1 yr) that a 21% improvement in visibility could be expected from a 10-million ton reduction in SO2 emissions. The biggest improvement is expected along the Ohio River Valley. Examining the distribution of visibility improvements shows that 15 d yr-1 with lowest sulfate concentrations and least sulfate reduction there will be a just perceptible improvement, while on the other end of the spectrum 15 d yr-1 with the highest sulfate concentration and with the largest sulfate reduction there will be a 35% improvement in extinction. The paper also reviews the assumptions required to carry out the assessment and points out shortcomings in our understanding of the relationship between SO2 emissions and visibility. C1 COLORADO STATE UNIV,COOPERAT INST RES ATMOSPHER,FT COLLINS,CO 80523. SANTA FE RES CORP,BLOOMINGTON,MN 55438. US EPA,NOAA,LAS VEGAS,NV 89193. US EPA,DIV ATMOSPHER CHARACTERIZAT & MODELING,RES TRIANGLE PK,NC 27711. RP MALM, WC (reprint author), NATL PK SERV,CIRA FOOTHILLS CAMPUS,FT COLLINS,CO 80523, USA. NR 27 TC 12 Z9 12 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1994 VL 28 IS 5 BP 1023 EP 1034 DI 10.1016/1352-2310(94)90262-3 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR215 UT WOS:A1994NR21500031 ER PT J AU PITCHFORD, ML MALM, WC AF PITCHFORD, ML MALM, WC TI DEVELOPMENT AND APPLICATIONS OF A STANDARD VISUAL INDEX SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Conference on Visibility and Fine Particles CY SEP 15-18, 1992 CL VIENNA, AUSTRIA DE VISIBILITY; VISUAL PERCEPTION; VISIBILITY VALUATION; EXTINCTION COEFFICIENT AB A standard visual index appropriate for characterizing visibility through uniform hazes, is defined in terms of either of the traditional metrics: visual range or extinction coefficient. This index was designed to be linear with respect to perceived visual changes over its entire range in a way that is analogous to the decibel scale for sound. Neither visual range nor extinction coefficient have this useful property, which has resulted in their misuse for some applications. By assuming the availability of sensitive scenic targets at every distance, it can be demonstrated that any specific fractional change in extinction coefficient (or visual range) is equally perceptible regardless of baseline visibility conditions. The new index is defined so that its scale, which is expressed in deciview (dnu), is linear with respect to fractional changes in extinction coefficient, b(ext), as 10 ln(b(ext)/0.01 km-1), where extinction coefficient is expressed in km-1. A 1 dnu change is about a 10% change in extinction coefficient, which is a small but perceptible scenic change under many circumstances. Since the deciview scale is near zero for a pristine atmosphere (dnu = 0 for Rayleigh conditions at about 1.8 km elevation) and increases as visibility is degraded, it measures perceived haziness. Use of the deciview scale in visibility perception and benefits research will promote improved study design and more appropriate use of results. It should also allow the visibility consequences of alternative air pollution-related decisions to be more easily presented and evaluated. C1 COLORADO STATE UNIV,NATL PK SERV,AIR QUAL OFF,FT COLLINS,CO 80523. RP PITCHFORD, ML (reprint author), US EPA,NOAA,LAS VEGAS,NV 89193, USA. NR 15 TC 46 Z9 47 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1994 VL 28 IS 5 BP 1049 EP 1054 DI 10.1016/1352-2310(94)90264-X PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NR215 UT WOS:A1994NR21500033 ER PT J AU LAMBERTY, A DEBIEVRE, P MOODY, JR AF LAMBERTY, A DEBIEVRE, P MOODY, JR TI THE IRMM-INTERNATIONAL MEASUREMENT EVALUATION PROGRAM (IMEP) - REALIZATION OF TRACEABILITY TO THE SI SYSTEM BY FIELD LABORATORIES SO ATOMIC SPECTROSCOPY LA English DT Article C1 NIST,GAITHERSBURG,MD 20899. RP LAMBERTY, A (reprint author), EC,INST REFERENCE MAT & MEASUREMENTS,B-2440 GEEL,BELGIUM. NR 2 TC 4 Z9 4 U1 0 U2 2 PU PERKIN-ELMER CORP PI NORWALK PA 761 MAIN AVE, NORWALK, CT 06859-0105 SN 0195-5373 J9 ATOM SPECTROSC JI Atom. Spectrosc. PD MAR-APR PY 1994 VL 15 IS 2 BP 107 EP 108 PG 2 WC Spectroscopy SC Spectroscopy GA NL613 UT WOS:A1994NL61300008 ER PT J AU PRESSER, C GUPTA, AK AVEDISIAN, CT SEMERJIAN, HG AF PRESSER, C GUPTA, AK AVEDISIAN, CT SEMERJIAN, HG TI EFFECT OF DODECANOL CONTENT ON THE COMBUSTION OF METHANOL SPRAY FLAMES SO ATOMIZATION AND SPRAYS LA English DT Article ID LIQUID AB The structure of a swirl-stabilized spray flame, fueled by a 75/25 mixture (by volume) of methanol and dodecanol has been examined. Spatially resolved information on droplet size and velocity distributions was obtained under burning conditions using a phase Doppler interferometry system. The effect of system gain (i.e., voltage setting of the photomultiplier tube detectors and laser power) on interpretation of the results was also assessed. The relatively large volatility difference between methanol and dodecanol provided an opportunity to examine the occurrence of microexplosions within spray flames. Evidence of microexploded droplets was revealed by a sudden decrease in droplet size and velocity, and an increase in number density at different spatial positions within the flame. On this basis, results were obtained that indicated the occurrence of microexplosions in the 75/25 mixture flame, but at a reduced extent as compared to prior results reported for methanol flames containing a larger fraction of dodecanol. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. CORNELL UNIV,SIBLEY SCH MECH & AEROSP ENGN,ITHACA,NY 14853. RP PRESSER, C (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 12 TC 9 Z9 9 U1 0 U2 0 PU BEGELL HOUSE INC PI NEW YORK PA 79 MADISON AVE, SUITE 1205, NEW YORK, NY 10016-7892 SN 1044-5110 J9 ATOMIZATION SPRAY JI Atom. Sprays PD MAR-APR PY 1994 VL 4 IS 2 BP 207 EP 222 PG 16 WC Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA NK785 UT WOS:A1994NK78500005 ER PT J AU MIWA, S YAN, LG SWANSON, P AF MIWA, S YAN, LG SWANSON, P TI LOCALIZATION OF 2 GONADOTROPIN RECEPTORS IN THE SALMON GONAD BY IN-VITRO LIGAND AUTORADIOGRAPHY SO BIOLOGY OF REPRODUCTION LA English DT Article ID FOLLICLE-STIMULATING-HORMONE; ONCORHYNCHUS-RHODURUS; AMAGO SALMON; GTH-II; RAINBOW-TROUT; LUTEINIZING-HORMONE; OVARIAN FOLLICLES; SEXUAL-MATURATION; COHO SALMON; PITUITARY GONADOTROPHS AB Receptors for two salmon gonadotropins, GTH I and GTH II, were localized by use of in vitro ligand autoradiography of coho salmon gonads at various stages of sexual maturation. The results in both sexes revealed the presence of two types of GTH receptors: type I (GTH-RI), which interacts with both GTHs, and type II (GTH-RII), which interacts specifically with GTH II. GTH-RI was found at all stages of spermatogenesis examined and was localized on cells that were most likely Sertoli cells; however, it could not be determined whether GTH-RI was also localized on Leydig cells. In contrast, GTH-RI was found only in Leydig cells in the testis from a spermiating fish. In the vitellogenic ovary, GTH-RI was localized in the thecal layer and intensely on granulosa cells; in the preovulatory follicle, in contrast, GTH-RI was found in the thecal layer and in interstitial connective tissue, but not in the granulosa layer. Among all the stages of oogenesis examined, only granulosa cells of the preovulatory follicle exhibited GTH-RII. The appearance of GTH-RII coincides well with the in crease in plasma levels of GTH II that occurs during final oocyte maturation and spermiation in coho salmon. The nature, distribution, and timing of appearance of these two receptors can explain, at least in part, the results of previous studies on steroidogenic activities of the two GTHs. The present study also suggests the functional homology of salmon GTH I and GTH II to mammalian FSH and LH, respectively, during gonadal development. C1 NW FISHERIES SCI CTR,SEATTLE,WA 98112. NR 61 TC 97 Z9 108 U1 0 U2 8 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD MAR PY 1994 VL 50 IS 3 BP 629 EP 642 DI 10.1095/biolreprod50.3.629 PG 14 WC Reproductive Biology SC Reproductive Biology GA MX277 UT WOS:A1994MX27700021 PM 8167235 ER PT J AU HSU, JC HWANG, JTG LIU, HK RUBERG, SJ AF HSU, JC HWANG, JTG LIU, HK RUBERG, SJ TI CONFIDENCE-INTERVALS ASSOCIATED WITH TESTS FOR BIOEQUIVALENCE SO BIOMETRIKA LA English DT Article DE BIOEQUIVALENCE; CONFIDENCE COEFFICIENT; CONFIDENCE INTERVAL; CONFIDENCE SEQUENCE; COVERAGE PROBABILITY; SYMMETRICAL CONFIDENCE INTERVAL ID COMPARATIVE BIOAVAILABILITY TRIALS; CLINICAL-TRIALS; EQUIVALENCE AB Previously, the connection between bioequivalence tests and their associated confidence intervals was not well understood. In fact, the alpha-level two one-sided tests approach was thought to be associated with a 1 - 2 alpha confidence interval. In this paper, we build up connections which allow us to construct 1 - alpha confidence intervals from alpha-level tests and vice versa. When applied to the alpha-level two one-sided tests, the resultant 1 - alpha confidence intervals are properly contained in Westlake's 1 - alpha symmetric interval (1976). Our approach is readily generalized to different settings, including the nonparametric setting, the ratio parameter setting, and the repeated confidence interval setting. C1 CORNELL UNIV,DEPT MATH,ITHACA,NY 14853. MARION MERRELL DOW INC,DEPT STAT,KANSAS CITY,MO 64137. NIST,DIV STAT ENGN,GAITHERSBURG,MD 20899. RP HSU, JC (reprint author), OHIO STATE UNIV,DEPT STAT,1958 NEIL AVE,COLUMBUS,OH 43210, USA. NR 34 TC 58 Z9 58 U1 1 U2 3 PU BIOMETRIKA TRUST PI LONDON PA UNIV COLLEGE LONDON GOWER ST-BIOMETRIKA OFFICE, LONDON, ENGLAND WC1E 6BT SN 0006-3444 J9 BIOMETRIKA JI Biometrika PD MAR PY 1994 VL 81 IS 1 BP 103 EP 114 PG 12 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA NL538 UT WOS:A1994NL53800010 ER PT J AU KISHORE, N TEWARI, YB YAP, WT GOLDBERG, RN AF KISHORE, N TEWARI, YB YAP, WT GOLDBERG, RN TI THERMODYNAMICS OF THE HYDROLYSIS OF PENICILLIN-G AND AMPICILLIN SO BIOPHYSICAL CHEMISTRY LA English DT Article DE ACIDITY CONSTANTS; AMPICILLIN; APPARENT EQUILIBRIUM CONSTANTS; CALORIMETRY; CEPHALOSPORIN C; ENTHALPY; BETA-LACTAMASE; PENICILLIN G; THERMODYNAMICS ID PHYSICOCHEMICAL PROPERTIES; SPECIFIED PH; EQUILIBRIUM; DEGRADATION; SYSTEMS; PROTON; PMG AB Apparent equilibrium constants and calorimetric enthalpies of reaction have been measured for the beta-lactamase catalyzed hydrolysis of penicillin G(aq) and ampicillin(aq) to penicillinoic acid(aq) and to ampicillinoic acid(aq), respectively. High-pressure liquid-chromatography and microcalorimetery were used to perform these measurements. The results for the reference reactions at T = 298.15 K and I-m = 0 are: K degrees = (9.4 +/- 3.1) x 10(-7), Delta(r)G degrees = (34.4 +/- 1.0) kJ mol(-1), Delta(r)H degrees = -(73.7 +/- 0.4) kJ mol(-1), and Delta(r)S degrees = -(363 +/- 4) J K-1 mol(-1) for penicillin G(-)(aq)+ H2O(1)= penicillinoic acid(2-)(aq)S H+(aq); K degrees = (6.0 +/- 3.0) X 10(-6), Delta(r)G degrees = (29.8 +/- 1.7) kJ mol(-1), Delta(r)H degrees = -(70.0 +/- 7.5) kJ mol(-1), and Delta(r)S degrees = - (335 +/- 26) J K-1 mol(-1) for ampicillin(-)(aq)+ H2O(1)= ampicillinoic acid(2-)(aq)+ H+(aq). Calorimetric enthalpies of reaction for the p-lactamase cat alyzed hydrolysis of cephalosporin C have also been measured but the reaction products have not been identified and the measured enthalpies cannot be assigned to a specific reaction. Acidity constants for ampicillin, penicillin G, ampicillinoic acid, and penicillinoic acid are also reported. A strain energy of 116 kJ mol(-1) for the beta-lactam ring is obtained from thermochemical data. C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 30 TC 9 Z9 9 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD MAR PY 1994 VL 49 IS 2 BP 163 EP 174 DI 10.1016/0301-4622(93)E0067-F PG 12 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA MZ863 UT WOS:A1994MZ86300006 PM 8155816 ER PT J AU ANGEVINE, WM WHITE, AB AVERY, SK AF ANGEVINE, WM WHITE, AB AVERY, SK TI BOUNDARY-LAYER DEPTH AND ENTRAINMENT ZONE CHARACTERIZATION WITH A BOUNDARY-LAYER PROFILER SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID RADAR AB A technique for determining the height of the convective atmospheric boundary layer (CBL) with a 915 MHz boundary-layer profiler is discussed. The results are compared with CBL heights determined from radiosonde measurements. The profiler provides continuous CBL height measurements with very good time resolution (30 minutes or less), allowing for detailed understanding of the growth and fluctuations of the CBL. In addition, the profiler provides information about the degree of definition of the CBL top and the thickness of the entrainment zone. The measurements discussed were taken during the Rural Oxidants in the Southern Environment II (ROSE II) experiment. RP ANGEVINE, WM (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. RI White, Allen/A-7946-2009; Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 10 TC 150 Z9 164 U1 3 U2 22 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 MAR PY 1994 VL 68 IS 4 BP 375 EP 385 DI 10.1007/BF00706797 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NQ626 UT WOS:A1994NQ62600003 ER PT J AU PENNER, JE CHARLSON, RJ HALES, JM LAULAINEN, NS LEIFER, R NOVAKOV, T OGREN, J RADKE, LF SCHWARTZ, SE TRAVIS, L AF PENNER, JE CHARLSON, RJ HALES, JM LAULAINEN, NS LEIFER, R NOVAKOV, T OGREN, J RADKE, LF SCHWARTZ, SE TRAVIS, L TI QUANTIFYING AND MINIMIZING UNCERTAINTY OF CLIMATE FORCING BY ANTHROPOGENIC AEROSOLS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID CLOUD-CONDENSATION-NUCLEI; LONG-RANGE TRANSPORT; SULFATE AEROSOL; ATMOSPHERIC SULFUR; OPTICAL-PROPERTIES; RADIATIVE-TRANSFER; MARINE ATMOSPHERE; ORGANIC AEROSOLS; SOLAR-RADIATION; ARCTIC HAZE AB Anthropogenic aerosols are composed of a variety of aerosol types and components including water-soluble inorganic species (e.g., sulfate, nitrate, ammonium), condensed organic species, elemental or black carbon, and mineral dust. Previous estimates of the clear sky forcing by anthropogenic sulfate aerosols and by organic biomass-burning aerosols indicate that this forcing is of sufficient magnitude to mask the effects of anthropogenic greenhouse gases over large regions. Here, the uncertainty in the forcing by these aerosol types is estimated. The clear sky forcing by other anthropogenic aerosol components cannot be estimated with confidence, although the forcing by these aerosol types appears to be smaller than that by sulfate and biomass-burning aerosols. The cloudy sky forcing by anthropogenic aerosols, wherein aerosol cloud condensation nuclei concentrations are increased, thereby increasing cloud droplet concentrations and cloud albedo and possibly influencing cloud persistence, may also be significant. in contrast to the situation with the clear sky forcing, estimates of the cloudy sky forcing by anthropogenic aerosols are little more than guesses, and it is not possible to quantity the uncertainty of the estimates. In view of present concerns over greenhouse gas-induced climate change, this situation dictates the need to quantify the forcing by anthropogenic aerosols and to define and minimize uncertainties in the calculated forcings. In this article, a research strategy for improving the estimates of the clear sky forcing is defined. The strategy encompasses five major, and necessarily coordinated, activities: surface-based observations of aerosol chemical and physical properties and their influence on the radiation field; aircraft-based observations of the same properties; process studies to refine model treatments; satellite observations of aerosol abundance and size distribution; and modeling studies to demonstrate consistency between the observations, to provide guidance for determination of the most important parameters, and to allow extension of the limited set of observations to the global scale. Such a strategy, if aggressively implemented, should allow these effects to be incorporated into climate models in the next several years. A similar strategy for defining the magnitude of the cloudy sky forcing should also be possible, but the less firm understanding of this forcing suggests that research of a more exploratory nature be carried out before undertaking a research strategy of the magnitude recommended for the clear sky forcing. C1 UNIV WASHINGTON, SEATTLE, WA 98195 USA. ENVAIR, RICHLAND, WA USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. ENVIRONM MEASUREMENTS LAB, NEW YORK, NY USA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. RP PENNER, JE (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, L-262, LIVERMORE, CA 94550 USA. RI Schwartz, Stephen/C-2729-2008; Penner, Joyce/J-1719-2012 OI Schwartz, Stephen/0000-0001-6288-310X; NR 92 TC 276 Z9 280 U1 5 U2 42 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1994 VL 75 IS 3 BP 375 EP 400 DI 10.1175/1520-0477(1994)075<0375:QAMUOC>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NC607 UT WOS:A1994NC60700003 ER PT J AU ARKIN, PA XIE, PP AF ARKIN, PA XIE, PP TI THE GLOBAL PRECIPITATION CLIMATOLOGY PROJECT - 1ST ALGORITHM INTERCOMPARISON PROJECT SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SATELLITE-DERIVED RAINFALL; TROPICAL OCEANIC RAINFALL; SOUTHERN OSCILLATION; SCALE PRECIPITATION; SURFACE-TEMPERATURE; SURROUNDING WATERS; JAPAN; MICROWAVE; CLOUD; VARIABILITY AB The Global Precipitation Climatology Project (GPCP) was established by the World Climate Research Programme to produce global analyses of area- and time-averaged precipitation for use in climate research. To achieve the required spatial coverage, the GPCP uses simple rainfall estimates derived from IR and microwave satellite observations. In this paper, we describe the GPCP and its first Algorithm Intercomparison Project (AIP/1), which compared a variety of rainfall estimates derived from Geostationary Meteorological Satellite visible and IR observations and Special Sensor Microwave/Imager microwave observations with rainfall derived from a combination of radar and raingage data over the Japanese islands and the adjacent ocean regions during the June and mid-July through mid-August periods of 1989. To investigate potential improvements in the use of satellite IR data for the estimation of large-scale rainfall for the GPCP, the relationship between rainfall and the fractional coverage of cold clouds in the AIP/1 dataset is examined. Linear regressions between fractional coverage and rainfall are analyzed for a number of latitude-longitude areas and for a range of averaging times. The results show distinct differences in the character of the relationship for different portions of the area. In general, to the south and east of the mountainous axis of Japan, rainfall and fractional coverage are highly correlated for thresholds colder than 245 K, and correlations can be increased by averaging in space and in time up to the dominant period of the precipitation events. To the north and west of the axis, the correlations between rainfall and fractional coverage, while generally smaller for all scales, are highest for thresholds warmer than 245 K. The proportional coefficients relating rainfall to fractional coverage at cold thresholds, however, differ greatly between the two periods and both differ significantly from those found for the GARP (Global Atmospheric Research Program) Atlantic Tropical Experiment. These results suggest that the simple IR-based estimation technique currently used in the GPCP can be used to estimate rainfall for global tropical and subtropical areas, provided that a method for adjusting the proportional coefficient for varying areas and seasons can be determined. RP ARKIN, PA (reprint author), NATL METEOROL CTR, NOAA, WOMC, NWS, WASHINGTON, DC 20233 USA. RI Arkin, Phillip/F-5808-2010 NR 52 TC 149 Z9 165 U1 2 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1994 VL 75 IS 3 BP 401 EP 419 DI 10.1175/1520-0477(1994)075<0401:TGPCPF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NC607 UT WOS:A1994NC60700004 ER PT J AU KATO, S FROST, MJ BIERBAUM, VM LEONE, SR AF KATO, S FROST, MJ BIERBAUM, VM LEONE, SR TI VIBRATIONAL SPECIFICITY FOR CHARGE-TRANSFER VERSUS DEACTIVATION IN N-2(+) (UPSILON=0, 1, 2) PLUS AR AND O-2 REACTIONS SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article ID ION-MOLECULE REACTIONS; STATE-TO-STATE; LASER-INDUCED FLUORESCENCE; CROSS-SECTIONS; TEMPERATURE-DEPENDENCE; THERMAL ENERGIES; EXCITED N-2+; COLLISIONS; O2; N+ AB Rate constants for charge transfer and vibrational deactivation in the N-2(+)(X(2) Sigma(g)(+), upsilon = 0, 1, 2) + Ar and O-2 reactions are directly measured by a state-resolved optical detection method. The novel selected-ion flow tube, laser-induced fluorescence (SIFT-LIF) technique is used to study the vibrationally specific reactions at near-thermal collision energy. The total rate constant for N-2(+)(upsilon = 1, 2) + Ar increases by more than a factor of 40 relative to N-2(+)(upsilon = 0). This enhancement is due exclusively to an increase in the charge transfer channel. The charge transfer rate constants for the N-2(+)(upsilon) + Ar reaction are found to be almost identical for upsilon 1 and upsilon = 2; this differs slightly from previous results at higher collision energies. The vibrational deactivation rate constant for the N-2(+)(upsilon = 1) + Ar reaction is measured for the first time; the upper limit for the branching fraction is approximate to 3%, confirming that this reaction is a useful monitor for N-2(+)(upsilon > 0) The total rate constant for N-2(+)(upsilon = 1, 2) + O-2 increases by factors of 2.6 and 3.3, respectively, relative to N-2(+)(upsilon = 0) In contrast to the N-2(+) + Ar reaction, this enhancement is largely due to the occurrence of vibrational deactivation, which is found to be slightly faster for upsilon = 2 than for upsilon = 1. For N-2(+)(upsilon = 2)+ O-2, the upsilon = 2 --> 1 and upsilon = 2 --> 0 vibrational deactivation channels are found to occur with comparable rates. The lack of substantial enhancement in the charge transfer channel in the N-2(+)(upsilon)+O-2 reaction by vibrational excitation (up to upsilon = 2) is in contrast to the observed translational enhancement, which opens a higher lying, endothermic O-2(+)(a(4)II(u)) product channel. These results are consistent with a short-range, curve-crossing mechanism that efficiently channels energy into the O-2(+)(a(4)II(u)) state. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, DIV QUANTUM PHYS, BOULDER, CO 80303 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 53 TC 18 Z9 18 U1 0 U2 4 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD MAR PY 1994 VL 72 IS 3 BP 625 EP 636 DI 10.1139/v94-087 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA NL412 UT WOS:A1994NL41200020 ER PT J AU PLISETSKAYA, EM MOON, TW LARSEN, DA FOSTER, GD DICKHOFF, WW AF PLISETSKAYA, EM MOON, TW LARSEN, DA FOSTER, GD DICKHOFF, WW TI LIVER-GLYCOGEN, ENZYME-ACTIVITIES, AND PANCREATIC HORMONES IN JUVENILE ATLANTIC SALMON (SALMO-SALAR) DURING THEIR 1ST SUMMER IN SEAWATER SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PARR-SMOLT TRANSFORMATION; COD GADUS-MORHUA; COHO SALMON; ONCORHYNCHUS-KISUTCH; GLUCAGONLIKE PEPTIDE; HEPATIC GLYCOGEN; INSULIN; GLUCOSE; METABOLISM; AMYLIN AB Our observation of very low liver glycogen concentration in 1-yr-old feeding Atlantic salmon (Salmo salar) in seawater net-pens in Puget Sound, Washington, led to studies of their metabolic status. We assessed liver glycogen concentration, activities of some hepatic enzymes involved in glycogen synthesis, depletion, and gluconeogenesis, and plasma profiles of glucose and pancreatic hormones (insulin and glucagon) in yearling Atlantic salmon before and after seawater transfer. Liver glycogen concentration in Atlantic salmon during the several months after seawater entry was much lower than in coho salmon (Oncorhynchus kisutch) of the same age in seawater. Other metabolic and hormonal indices throughout the study did not differ substantially between the two species. During their first summer in seawater netpens, seemingly healthy, feeding 1-yr-old Atlantic salmon smolts are prone to high mortality. We hypothesize that the virtual absence of glycogen reserves in the liver makes seawater-adapted 1-yr-old Atlantic salmon juveniles particularly susceptible to stress and may contribute to high summer mortality. C1 UNIV OTTAWA,DEPT BIOL,OTTAWA K1N 6N5,ONTARIO,CANADA. NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. UNIV OTTAWA,DEPT BIOL,OTTAWA K1N 6N5,ONTARIO,CANADA. RP PLISETSKAYA, EM (reprint author), UNIV WASHINGTON,SCH FISHERIES HF-15,SEATTLE,WA 98195, USA. NR 45 TC 18 Z9 19 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 MAR PY 1994 VL 51 IS 3 BP 567 EP 576 DI 10.1139/f94-059 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA NN390 UT WOS:A1994NN39000009 ER PT J AU ROUSE, RC PEACOR, DR DUNN, PJ SU, SC CHI, PH YEATES, H AF ROUSE, RC PEACOR, DR DUNN, PJ SU, SC CHI, PH YEATES, H TI SAMFOWLERITE, A NEW CA MN ZN BERYLLOSILICATE MINERAL FROM FRANKLIN, NEW-JERSEY - ITS CHARACTERIZATION AND CRYSTAL-STRUCTURE SO CANADIAN MINERALOGIST LA English DT Article DE SAMFOWLERITE; NEW MINERAL SPECIES; CRYSTAL STRUCTURE; BERYLLOSILICATE OF CALCIUM; MANGANESE AND ZINC; FRANKLIN; NEW-JERSEY AB Samfowlerite, ideally Ca14Mn3Zn2(Zn,Be)2Be6(SiO4)6(Si2O7)4(OH,F)6, is monoclinic, P2(1)/c, with a 9.068(2), b 17.992(2), c 14.586(2) angstrom, beta 104.86(1)-degrees, and Z = 2. It occurs as colorless 0.05-mm-diameter crystals in andradite-lined vugs in franklinite - willemite ore from Franklin, Sussex County, New Jersey. Electron- and ion-microprobe analyses yielded CaO 34.1, MgO 0.2, MnO 9.3, ZnO 9.5, BeO 5.6, SiO2 36.9, F 1.0, H2O (by difference) 3.8, less O=F 0.4, total 100 wt%. Optically, it is biaxial negative, 2V 29.0(1)-degrees, with alpha 1.674(3), beta 1.680(3), and gamma 1.681(3). The measured and calculated densities are 3.28 +/- 0.05 and 3.31 g/cm3, respectively. The strongest powder X-ray-diffraction lines are [d in angstrom (I)(hkl)]: 2.863(100)(321BAR,053), 2,653(50)(251), 2.388(50)(334BAR,172BAR), 2.771(40)(125BAR), 2.272(30)(172,234,402BAR,155BAR), 1.832(30)(374BAR), 1.860(20)(327BAR,406BAR,066), and 1.803(20)(381BAR,0.10.0,382BAR). The crystal structure has been solved and refined to an unweighted residual of 0.043 for 2495 observed reflections. Although samfowlerite is, strictly speaking, a mixed-anion (SiO4 and Si2O7) silicate, the structure may be viewed as being composed of layers of vertex-sharing TO4 tetrahedra (T = Si,Be,Zn) alternating with layers of vertex- and edge-sharing CaO8 bicapped trigonal prisms and MnO6 octahedra, the layers being parallel to (102). The TO4 groups and CaO8-MnO6 groups share vertices with one another across the layer boundaries to form the three-dimensional structure. Within the layers of tetrahedra, the TO4 groups form a network of 4-, 5-, and 8-membered rings. The apparent substitution of Be for Zn in the ratio 5/8 to 3/8 on one of the T sites suggests that the space group P2(1)/c is only that of an average structure, and that the true structure is of lower symmetry, with ordering of Zn and Be on separate sites. C1 SMITHSONIAN INST,DEPT MINERAL SCI,WASHINGTON,DC 20560. HERCULES INC,RES CTR,WILMINGTON,DE 19894. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP ROUSE, RC (reprint author), UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109, USA. NR 8 TC 6 Z9 6 U1 0 U2 2 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD MAR PY 1994 VL 32 BP 43 EP 53 PN 1 PG 11 WC Mineralogy SC Mineralogy GA NK856 UT WOS:A1994NK85600005 ER PT J AU HUGHES, MK DIAZ, HF AF HUGHES, MK DIAZ, HF TI WAS THERE A MEDIEVAL WARM PERIOD, AND IF SO, WHERE AND WHEN SO CLIMATIC CHANGE LA English DT Article ID SUMMER TEMPERATURE PATTERNS; TREE-RING DENSITY; NORTHERN HEMISPHERE; CLIMATIC CHANGES; SIERRA-NEVADA; UNITED-STATES; RECONSTRUCTION; RECORD; EASTERN; AMERICA AB It has frequently been suggested that the period encompassing the ninth to the fourteenth centuries A.D. experienced a climate warmer than that prevailing around the turn of the twentieth century. This epoch has become known as the Medieval Warm Period, since it coincides with the Middle Ages in Europe. In this review a number of lines of evidence are considered, (including climate-sensitive tree rings, documentary sources, and montane glaciers) in order to evaluate whether it is reasonable to conclude that climate in medieval times was, indeed, warmer than the climate of more recent times. Our review indicates that for some areas of the globe (for example, Scandinavia, China, the Sierra Nevada in California, the Canadian Rockies and Tasmania), temperatures, particularly in summer, appear to have been higher during some parts of this period than those that were to prevail until the most recent decades of the twentieth century. These warmer regional episodes were not strongly synchronous. Evidence from other regions (for example, the Southeast United States, southern Europe along the Mediterranean, and parts of South America) indicates that the climate during that time was little different to that of later times, or that warming, if it occurred, was recorded at a later time than has been assumed. Taken together, the available evidence does not support a global Medieval Warm Period, although more support for such a phenomenon could be drawn from high-elevation records than from low-elevation records. The available data exhibit significant decadal to century scale variability throughout the last millennium. A comparison of 30-year averages for various climate indices places recent decades in a longer term perspective. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,ERL,CDC,BOULDER,CO 80303. RP HUGHES, MK (reprint author), UNIV ARIZONA,TREE RING RES LAB,TUCSON,AZ 85721, USA. RI Hughes, Malcolm/F-3350-2014 OI Hughes, Malcolm/0000-0003-1062-3167 NR 88 TC 326 Z9 355 U1 3 U2 51 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD MAR PY 1994 VL 26 IS 2-3 BP 109 EP 142 DI 10.1007/BF01092410 PG 34 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NP890 UT WOS:A1994NP89000001 ER PT J AU DIAZ, HF PULWARTY, RS AF DIAZ, HF PULWARTY, RS TI AN ANALYSIS OF THE TIME SCALES OF VARIABILITY IN CENTURIES-LONG ENSO-SENSITIVE RECORDS IN THE LAST 1000 YEARS SO CLIMATIC CHANGE LA English DT Article ID SOUTHERN OSCILLATION; CLIMATIC FLUCTUATIONS; GLOBAL TEMPERATURE; SERIES AB We document the characteristic time scales of variability for seven climate indices whose time-dependent behavior is sensitive to some aspect of the El Nino/Southern Oscillation (ENSO). The ENSO sensitivity arises from the location of these long-term records on the periphery of the Indian and Pacific Oceans. Three of the indices are derived principally from historical sources, three others consist of tree-ring reconstructions (one of summer temperature, and the other two of winter rainfall), and one is an annual record of oxygen isotopic composition for a high-elevation glacier in Peru. Five of the seven indices sample at least portions of the Medieval Warm Period (approximately A.D. 950 to 1250). Time series spectral analysis was used to identify the major time scales of variability among the different indices. We focus on two principal time scales: a high frequency band (approximately 2-10 yr), which comprises most of the variability found in the modem record of ENSO activity, and a low frequency band to highlight variations on decadal to century time scales (11 < P < 150 yr). This last spectral band contains variability on time scales that are of general interest with respect to possible changes in large-scale air-sea exchanges. A technique called evolutive spectral analysis (ESA) is used to ascertain how stable each spectral peak is in time. Coherence and phase spectra are also calculated among the different indices over each full common period, and following a 91-yr window through time to examine whether the relationships change. In general, spectral power on time scales of approximately 2-6 yr is statistically significant and persists throughout most of the time intervals sampled by the different indices. Assuming that the ENSO phenomenon is the source of much of the variability at these time scales, this indicates that ENSO has been an important part of interannual climatic variations over broad areas of the circum-Pacific region throughout the last millennium. Significant coherence values were found for El Nino and reconstructed Sierra Nevada winter precipitation at approximately 2-4 yr throughout much of their common record (late 1500s to present) and between 6 and 7 yr from the mid-18th to the early 20th century. At decadal time scales each record generally tends to exhibit significant spectral power over different periods at different times. Both the Quelccaya Ice Cap deltaO-18 series and the Quinn El Nino event record exhibit significant spectral power over frequencies approximately 35 to 45 yr; however, there is low coherence between these two series at those frequencies over their common record. The Sierra Nevada winter rainfall reconstruction exhibits consistently strong variability at periods of approximately 30-60 yr. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT GEOG,BOULDER,CO 80309. RP DIAZ, HF (reprint author), NOAA,ERL,CDC,325 BROADWAY,BOULDER,CO 80303, USA. NR 49 TC 59 Z9 67 U1 1 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD MAR PY 1994 VL 26 IS 2-3 BP 317 EP 342 DI 10.1007/BF01092422 PG 26 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NP890 UT WOS:A1994NP89000013 ER PT J AU BARNES, G MOYER, DD GJATA, G AF BARNES, G MOYER, DD GJATA, G TI EVALUATING THE EFFECTIVENESS OF ALTERNATIVE APPROACHES TO THE SURVEYING AND MAPPING OF CADASTRAL PARCELS IN ALBANIA SO COMPUTERS ENVIRONMENT AND URBAN SYSTEMS LA English DT Article AB This paper describes the challenges facing Albania and other eastern European countries as they move towards a private property system that requires a comprehensive cadastre and land registration system (C&LRS). The foundation of a C&LRS is created through the survey and mapping of individual parcels. The challenge in Albania is to put in place an orderly C&LRS before an active land market emerges involving the transfer subdivision, and consolidation of property parcels. To achieve this, it will be necessary to survey over 2 million parcels. If this goal is to be achieved within the existing time constraints, it will be essential to select the most effective approaches towards surveying and mapping. This paper describes the existing surveying and mapping environment in Albania, as well as the most feasible options. An evaluation model has been developed as a means of evaluating the most effective approach under different circumstances. By collecting data on inputs, field conditions, and productivity during the first part of a C&LRS project, this research aims to identify how competitive existing approaches are with respect to other more modern approaches such as GPS. C1 NATL GEODET SURV,MADISON,WI. TIRANA POLYTECH,TIRANE,ALBANIA. RP BARNES, G (reprint author), UNIV FLORIDA,DEPT CIVIL ENGN,345 WEIL HALL,GAINESVILLE,FL 32601, USA. NR 3 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 0198-9715 J9 COMPUT ENVIRON URBAN JI Comput. Environ. Urban Syst. PD MAR-APR PY 1994 VL 18 IS 2 BP 123 EP 131 DI 10.1016/0198-9715(94)90007-8 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Environmental; Environmental Studies; Geography; Operations Research & Management Science SC Computer Science; Engineering; Environmental Sciences & Ecology; Geography; Operations Research & Management Science GA NM691 UT WOS:A1994NM69100007 ER PT J AU DICKENSVENZ, SH TAKAGI, S CHOW, LC BOWEN, RL JOHNSTON, AD DICKENS, B AF DICKENSVENZ, SH TAKAGI, S CHOW, LC BOWEN, RL JOHNSTON, AD DICKENS, B TI PHYSICAL AND CHEMICAL-PROPERTIES OF RESIN-REINFORCED CALCIUM-PHOSPHATE CEMENTS SO DENTAL MATERIALS LA English DT Article ID GLASS-IONOMER; HYDROXIDE; DENTIN AB Objectives. The purpose of this study was to improve the handling and physical properties of a self-setting, water-based calcium phosphate cement by combining it with polymerizable resins and to study the setting reactions involved. Methods. Dual-cured composite cements were prepared from a calcium phosphate cement powder and dental monomers that contain carboxylated hydrophilic resins or resin/water mixtures. The setting reaction of the calcium phosphate cement in the presence of the resins was evaluated by pH measurements, infrared spectroscopy, diametral tensile strength, x-ray diffraction analysis, and scanning electron microscopy. Results. Carboxylated resins were chosen because they can form ionic bonds to the mineral filler, which was confirmed by appearance of an infrared absorbance peak at 1552 cm(-1) within 24 h after mixing due to the formation of a carboxylate salt. Hydroxyapatite did not develop in composites prepared from resin and calcium phosphate cement. However, composites from calcium phosphate cement, resin and water showed approximately 40% hydroxyapatite. The resulting composite cements have moderately high DTS of 14-15 MPa and high pH. Significance. Hydrophilic acidic resins allows mixing with water and/or allow rapid diffusion of water into the resinous cement so that the dissolution and reprecipitation processes required for the conversion of the calcium phosphate components to hydroxyapatite can occur. The characteristics of the resulting composite cements suggest that the materials may be useful in pulp capping and/or cavity lining. C1 AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD. RP DICKENSVENZ, SH (reprint author), NIST,AMER DENT ASSOC HLTH FDN,PRC,DIV POLYMERS,BLDG 224,ROOM A153,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [P50 DE09322] NR 26 TC 42 Z9 44 U1 0 U2 3 PU ACAD DENTAL MATERIALS PI DALLAS PA BAYLOR COLLEGE DENTISTRY, 3302 GASTON AVE, DALLAS, TX 75266-0677 SN 0109-5641 J9 DENT MATER JI Dent. Mater. PD MAR PY 1994 VL 10 IS 2 BP 100 EP 106 DI 10.1016/0109-5641(94)90048-5 PG 7 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA PR224 UT WOS:A1994PR22400005 PM 7758844 ER PT J AU LANG, KL GRIMES, CB SHAW, RF AF LANG, KL GRIMES, CB SHAW, RF TI VARIATIONS IN THE AGE AND GROWTH OF YELLOWFIN TUNA LARVAE, THUNNUS-ALBACARES, COLLECTED ABOUT THE MISSISSIPPI RIVER PLUME SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE DAILY AGING; OTOLITHS; SAGITTAE; SCOMBRIDAE ID SOUTHERN BLUEFIN TUNA; SPATIAL-DISTRIBUTION; FISH; MACCOYII; MEXICO; GULF AB Eight hundred and one yellowfin tuna larvae ranging from 2.57-7.48 mm SL were collected near the Mississippi River discharge plume in the Gulf of Mexico during July and September, 1987. Larvae were most abundant at intermediate salinities (i.e. frontal waters) where chlorophyll a and macrozooplankton displacement values were also highest. Using sagittal otolith microstructure, we estimated larval ages ranging from 3-14 d. These ages were used to back calculate spawning dates from 13-24 July and 22-31 August. Mean absolute individual growth rate (length age-1) was 0.47 mm d-1, with the least squares linear regression SL = 1.67 + 0.47 AGE (r2 = 0.60, Pr > F = 0.0001) representing the best growth curve. Highest growth occurred at intermediate salinities near 31 parts per thousand, and temperatures near 29-degrees-C. There was significant temporal variation in growth, with larvae collected in July growing slower than those from September (0.37 and 0.48 mm d-1, respectively). The pooled instantaneous daily mortality rate (Z) of the larvae was estimated to be 0.33 d-1 (0.16 d-1 in July and 0.41 d-1 in September). These results show that significant spawning of yellowfin tuna may occur in the northern Gulf of Mexico in the vicinity of the Mississippi River discharge plume, and suggest that larval growth and survival may be enhanced in the plume frontal waters. C1 NOAA,NMFS,SEFSC,PANAMA CITY BEACH,FL 32408. LSU,COASTAL FISHERIES INST,CTR WETLAND RESOURCES,BATON ROUGE,LA 70803. RP LANG, KL (reprint author), NOAA,NMFS,NEFSC,166 WATER ST,WOODS HOLE,MA 02543, USA. NR 38 TC 48 Z9 48 U1 0 U2 6 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 MAR PY 1994 VL 39 IS 3 BP 259 EP 270 DI 10.1007/BF00005128 PG 12 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA NA684 UT WOS:A1994NA68400005 ER PT J AU DAVIS, MW OLLA, BL AF DAVIS, MW OLLA, BL TI ONTOGENIC SHIFT IN GEOTAXIS FOR WALLEYE POLLOCK, THERAGRA-CHALCOGRAMMA FREE EMBRYOS AND LARVAE - POTENTIAL ROLE IN CONTROLLING VERTICAL-DISTRIBUTION SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Note DE BEHAVIOR; BUOYANCY; ORIENTATION; RESTING; SWIMMING; YOLKSAC LARVAE ID LIGHT; RESPONSES AB The behavioral capability of walleye pollock, Theragra chalcogramma free embryos and larvae to control vertical distribution was assessed by examining buoyancy during resting and swimming orientation and activity as they developed in complete darkness from hatching to first feeding readiness (1 to 7 d post hatching at 6-degrees-C). Free embryos exhibited positive geotaxis 1 d post hatching, actively swimming through a density gradient to remain in the lower water column. Activity increased with free embryo development and by 7 d post hatching, feeding-ready larvae reversed their vertical orientation, now exhibiting negative geotaxis as they migrated to the upper water column. The results indicate that even at the earliest developmental stages, walleye pollock possess the capability to control vertical distribution. Laboratory results are compared with patterns of vertical distribution observed in the sea. RP DAVIS, MW (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD MAR PY 1994 VL 39 IS 3 BP 313 EP 318 DI 10.1007/BF00005132 PG 6 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA NA684 UT WOS:A1994NA68400009 ER PT J AU EMENHISER, C SCHWARTZ, SJ SANDER, LC AF EMENHISER, C SCHWARTZ, SJ SANDER, LC TI HPLC SEPARATION OF CIS-TRANS-CAROTENOIDS IN HUMAN SERUM USING A NOVEL C30 STATIONARY-PHASE SO FASEB JOURNAL LA English DT Meeting Abstract C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 2 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR PY 1994 VL 8 IS 4 BP A191 EP A191 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA ND196 UT WOS:A1994ND19601106 ER PT J AU MARGOLIS, SA AF MARGOLIS, SA TI ASCORBIC-ACID ASSAY - A COLLABORATIVE ASSESSMENT OF LABORATORY ACCURACY AND PRECISION SO FASEB JOURNAL LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR PY 1994 VL 8 IS 4 BP A446 EP A446 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA ND196 UT WOS:A1994ND19602578 ER EF