FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Weaver, JF Gruntfest, E Levy, GM AF Weaver, JF Gruntfest, E Levy, GM TI Two floods in Fort Collins, Colorado: Learning from a natural disaster SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB A flash flood in Fort Collins, Colorado, on 28 July 1997 resulted in 5 deaths, 62 injuries, and more than $250 million in property damage. Following the 1997 flood, a great many changes were made in the city's preparedness infrastructure. On 30 April 1999, a combination of heavy rain and melting snow caused a second, less serious flood event. This article reports on the changes implemented following the first flood and their effectiveness during the second. C1 Colorado State Univ, CIRA, NESDIS, NOAA, Ft Collins, CO 80523 USA. Ft Collins Off Emergency Management, Ft Collins, CO USA. RP Weaver, JF (reprint author), Colorado State Univ, CIRA, NESDIS, NOAA, Ft Collins, CO 80523 USA. NR 6 TC 17 Z9 18 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 2000 VL 81 IS 10 BP 2359 EP 2366 DI 10.1175/1520-0477(2000)081<2359:TFIFCC>2.3.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359QR UT WOS:000089624000003 ER PT J AU Keenan, T Rutledge, S Carbone, R Wilson, J Takahashi, T May, P Tapper, N Platt, M Hacker, J Sekelsky, S Moncrieff, M Saito, K Holland, G Crook, A Gage, K AF Keenan, T Rutledge, S Carbone, R Wilson, J Takahashi, T May, P Tapper, N Platt, M Hacker, J Sekelsky, S Moncrieff, M Saito, K Holland, G Crook, A Gage, K TI The Maritime Continent Thunderstorm Experiment (MCTEX): Overview and some results SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID NORTHERN AUSTRALIA; CONVECTIVE STORMS; MELVILLE ISLANDS; SQUALL LINES; PRECIPITATION; RADAR; SYSTEMS; CLOUD; WIND; IDENTIFICATION AB A description is given of the Maritime Continent Thunderstorm Experiment held over the Tiwi Islands (12 degrees S, 130 degrees E) during the period November-December 1995. The unique nature of regularly occurring storms over these islands enabled a study principally aimed at investigating the life cycle of island-initiated mesoscale convective systems within the Maritime Continent. The program objectives are first outlined and then selected results from various observationally based and modeling studies are summarized. These storms are shown to depend typically on island-scale forcing although external mesoscale disturbances can result in significant storm activity as they pass over the heated island. Particular emphasis is given to summarizing the environmental characteristics and the impact this has on the location of storm development and the associated rainfall distribution. The mean rainfall production from these storms is shown to be about 760 x 10(5) m(3), with considerable variability. The mesoscale evolution is summarized and during the rapid development phase the interaction of storms with preexisting convergence zones is highlighted. In situ microphysical observations show the occurrence of very large rain drops (up to 8-mm diameter) and very large concentrations of ice crystals in the -10 degrees to -60 degrees C temperature range associated with the very intense updrafts. Occurrence of graupel aloft is shown to be strongly linked to cloud to ground lightning. Polarimetric radar-based rainfall estimates using specific differential phase shift are shown to be considerably better than reflectivity based estimates. Studies relating to the structure of anvil cloud and the effect on the radiative heating profile are also summarized. Initial attempts at modeling storm development are also presented. Two different nonhydrostatic models on days with markedly different evolution are employed and indicate that the models show considerable promise in their ability to develop mesoscale systems. However, important differences still remain between observed storm evolution and that modeled. C1 Bur Meteorol Res Ctr, Melbourne, Vic 3001, Australia. Colorado State Univ, Ft Collins, CO 80523 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Obirin Univ, Tokyo, Japan. Monash Univ, Melbourne, Vic 3004, Australia. Commonwealth Sci & Ind Res Org, Div Atmospher Res, Melbourne, Vic, Australia. Flinders Univ S Australia, Adelaide, SA 5001, Australia. Univ Massachusetts, Amherst, MA 01003 USA. Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO USA. RP Keenan, T (reprint author), Bur Meteorol Res Ctr, GPO Box,1289K, Melbourne, Vic 3001, Australia. NR 62 TC 68 Z9 70 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 2000 VL 81 IS 10 BP 2433 EP 2455 DI 10.1175/1520-0477(2000)081<2433:TMCTEM>2.3.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359QR UT WOS:000089624000008 ER PT J AU Moser, HG Charter, RL Watson, W Ambrose, DA Butler, JL Charter, SR Sandknop, EM AF Moser, HG Charter, RL Watson, W Ambrose, DA Butler, JL Charter, SR Sandknop, EM TI Abundance and distribution of rockfish (Sebastes) larvae in the Southern California Bight in relation to environmental conditions and fishery exploitation SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID EL-NINO; YELLOWTAIL ROCKFISH; ECOSYSTEM RESPONSE; GENUS SEBASTES; PACIFIC-OCEAN; NE PACIFIC; CLIMATE; REPRODUCTION; VARIABILITY; JORDANI AB In this study we describe seasonal, interannual, and long-term changes in the larval abundance of six rockfish (Sebastes) taxa in relation to spawning biomass and to variability ill the ocean environment. We used rockfish larvae from a total of 11.472 CalCOFI plankton rows taken in the Southern California Bight from 1951 to 1998. Species included in the study were bocaccio (S. paucispinis), cowcod (S. levis), shortbelly rockfish (S. jordani). aurora rockfish (S. aurora), and splitnose rockfish (S. diploproa). Interannual trends in occurrance and abundance are described for each species in relation to biomass trends of adults and to changes in the ocean environment caused by ENSO events and by the cool and warm regimes of the Pacific Decadal Oscillation (PDO). Larval abundance of S. paucispinis and S. levis declined abruptly during the shift to a warm regime and continued to decline, as did the adult biomass. Abundance of S. jordani larvae declined during the regime shift but increased after the 1982-83 El Nino, reaching the peak value for the time series ill 1991. Within each regime, minor declines in larval occurrence and abundance were associated with ENSO episodes. The tightly grouped series of three La Nina events in 1970-76 immediately preceded the shift front the cool to the warm regime late in 1976 and may have contributed to the marked decline ill larval occurrence and abundance that, for most species, continued through the 1982-83 El Nino. The decline in larval rockfish abundance during the regime shift may be a consequence of the decline in rockfish populations caused by the expanding rockfish fishery; however, the ocean environment may be a causal factor, because larvae of S. jordani, an unexploited species, underwent declines similar to those of fishery target species during that period. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Moser, HG (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 70 TC 33 Z9 34 U1 3 U2 4 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 2000 VL 41 BP 132 EP 147 PG 16 WC Fisheries SC Fisheries GA 410HT UT WOS:000167435100009 ER PT J AU Schwing, FB Moore, CS Ralston, S Sakuma, KM AF Schwing, FB Moore, CS Ralston, S Sakuma, KM TI Record coastal upwelling in the California Current in 1999 SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID LARGE-SCALE; TRANSITION; PACIFIC; STATE AB An extremely unusual level of coastal upwelling in the spring and summer of 1999 over much of the California Current system (CCS) is described, based on direct and indirect observations. Wind and ocean anomalies in 1999, a period characterized by an equatorial La Nina, are compared to climate trends for the previous several years, and specifically contrasted with the extremes associated with the 1997-98 El Nino event. Conditions in the CCS during the spring and summer of 1999) were consistent with extremely high levels of sustained coastal upwelling. The Pacific Fisheries Environmental Laboratory (PFEL) upwelling indices reached record highs fur a series extending back to 1946. Strong, sustained upwelling-favorable winds were measured at coastal buoys through late 1998 and much of 1999. Coastal sea-surface temperatures (SSTs) were 3 degrees -4 degreesC below their seasonal mean in spring 1999, and about 10 degrees cooler than the region experienced in late 1997. Hydrographic surveys of central California suggest upwelling of water by 100 m or more relative to the long-term spring average. Coastal sea-level (CSL) anomalies ill the northern CCS were the lowest in at least 65 years. Greater than usual southward transport by the California Current is implied. A number of population and ecological changes observed during this period may be linked to the unusual ocean conditions and the striking transition from El Nino to La Nina. Physical conditions in the CCS can change swiftly and dramatically, and its marine populations appear to respond nearly as rapidly. The large physical and biological changes that occurred in 1999 may signify the initiation of a new climate regime for the CCS. C1 NOAA, Natl Marine Fisheries Serv, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. RP Schwing, FB (reprint author), NOAA, Natl Marine Fisheries Serv, Pacific Fisheries Environm Lab, 1352 Lighthouse Ave, Pacific Grove, CA 93950 USA. NR 19 TC 63 Z9 64 U1 0 U2 2 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 2000 VL 41 BP 148 EP 160 PG 13 WC Fisheries SC Fisheries GA 410HT UT WOS:000167435100010 ER PT J AU Thedinga, JF Wertheimer, AC Heintz, RA Maselko, JM Rice, SD AF Thedinga, JF Wertheimer, AC Heintz, RA Maselko, JM Rice, SD TI Effects of stock, coded-wire tagging, and transplant on straying of pink salmon (Oncorhynchus gorbuscha) in southeastern Alaska SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID POPULATIONS; TSHAWYTSCHA; HATCHERY AB Straying of pink salmon (Oncorhynchus gorbuscha) from two wild stocks (intertidal and upstream) in southeastern Alaska was estimated. Secondary factors (coded-wire tagging and transplanting of the intertidal stock) that may influence straying were also evaluated. In 1996, 321 494 fry were marked with either coded-wire tags or pelvic-fin clips. A total of 3828 marked adults were recovered in their natal streams and 79 strays were recovered in streams within 60 km of the release sites. The overall estimated straying rate was 5.1%. Estimated straying for the intertidal stock (9.2%) was higher than straying of the upstream stock (3.7%) but was not statistically different due to high variance of the estimates. The proportion of fish straying was significantly greater (P = 0.01) for coded-wire-tagged than for pelvic-fin-clipped fish for the upstream but not for the transplanted stock. Straying and distribution of the transplanted stock were more similar to those of the upstream stock, which was endemic to the natal watershed and release site of the transplant, than to those of the intertidal stock, which was the donor stock for the transplant. Although tagging may influence straying, incubation and initial estuarine environment appear to be major determinants of the natural straying of pink salmon in southeastern Alaska. C1 Natl Marine Fisheries Serv, NOAA, Alaska Fisheries Sci Ctr, Auke Bay Fisheries Lab, Juneau, AK 99801 USA. RP Thedinga, JF (reprint author), Natl Marine Fisheries Serv, NOAA, Alaska Fisheries Sci Ctr, Auke Bay Fisheries Lab, 11305 Glacier Hwy, Juneau, AK 99801 USA. EM john.thedinga@noaa.gov RI Piper, Walter/B-7908-2009 NR 35 TC 21 Z9 23 U1 0 U2 2 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 2000 VL 57 IS 10 BP 2076 EP 2085 DI 10.1139/cjfas-57-10-2076 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 371PX UT WOS:000165188300012 ER PT J AU Hutson, ND Reisner, BA Yang, RT Toby, BH AF Hutson, ND Reisner, BA Yang, RT Toby, BH TI Silver ion-exchanged zeolites Y, X, and low-silica X: Observations of thermally induced cation/cluster migration and the resulting effects on the equilibrium adsorption of nitrogen SO CHEMISTRY OF MATERIALS LA English DT Article ID BOND-VALENCE PARAMETERS; CRYSTAL-STRUCTURE; POWDER DIFFRACTION; AIR SEPARATION; CLUSTERS; SPECTROSCOPY; ETHYLENE; MOLECULE; CATIONS AB Silver is known to strongly affect the adsorptive properties of some zeolites. It is also known that thermal vacuum dehydration of some argentiferous zeolites leads to the formation of charged silver clusters within the zeolite. In this work we have synthesized silver zeolites of the types Y, X, and low-silica X. The zeolites were treated in such a way as to promote the formation of intracrystalline charged silver clusters. Equilibrium room-temperature isotherms were measured for adsorption of nitrogen for each of the zeolites after various heat treatments and dehydration. These materials were structurally characterized via Rietveld refinement using neutron powder diffraction data. Color changes upon heat treatment and subsequent X-ray photoemission spectroscopy confirmed some reduction of Ag+ --> Ag-0. The effects of various dehydration conditions, including the time, temperature, and atmosphere, on the room-temperature adsorption of nitrogen are discussed. Structural characterization, along with valence bond calculations, revealed the presence of cations in site II*, which are more active in Ag-LSX samples that were vacuum dehydrated at 450 degreesC as compared to those that were vacuum dehydrated at 350 degreesC. C1 Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Yang, RT (reprint author), Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. RI Toby, Brian/F-3176-2013; OI Toby, Brian/0000-0001-8793-8285; Reisner, Barbara/0000-0003-3160-0351 NR 30 TC 44 Z9 44 U1 1 U2 33 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 2000 VL 12 IS 10 BP 3020 EP 3031 DI 10.1021/cm000294n PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 366YT UT WOS:000090034400032 ER PT J AU Loureiro, SM Felser, C Huang, Q Cava, RJ AF Loureiro, SM Felser, C Huang, Q Cava, RJ TI Refinement of the crystal structures of strontium cobalt oxychlorides by neutron powder diffraction SO CHEMISTRY OF MATERIALS LA English DT Article AB The crystal structures of strontium cobalt oxychlorides of general formula Sr2CoO3Cl (Co-1L), Sr3Co2O5Cl2 (Co-2L), and Sr4Co3O7.5Cl2 (Co-3L) have been determined from neutron powder data. The compounds crystallize in tetragonal symmetry, space group P4/nmm (Co-1L) or I4/mmm (Co-2L and Co-3L). Their structures are analogous to the Ruddlesden-Popper phases of general formula Srn+1MnO2n+1. All three structures contain layers of highly distorted CoO5Cl octahedron. The Co-3L structure, in addition, has a layer of regular CoO6 octahedra. Because the in-plane oxygen position of the latter is partially occupied, some of the Co atoms adopt pyramidal coordination, with their basal planes parallel to the c-axis. The temperature dependence of the magnetic susceptibility is also reported. The moment per mole of Co atom decreases with increasing number of (CoO2) layers. C1 Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08544 USA. Univ Mainz, Inst Anorgan & Anal Chem, D-55099 Mainz, Germany. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Loureiro, SM (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. RI Felser, Claudia/A-5779-2009 OI Felser, Claudia/0000-0002-8200-2063 NR 9 TC 36 Z9 36 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 2000 VL 12 IS 10 BP 3181 EP 3185 DI 10.1021/cm000410m PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 366YT UT WOS:000090034400053 ER PT J AU Covey, C Abe-Ouchi, A Boer, GJ Boville, BA Cubasch, U Fairhead, L Flato, GM Gordon, H Guilyardi, E Jiang, X Johns, TC Le Treut, H Madec, G Meehl, GA Miller, R Noda, A Power, SB Roeckner, E Russell, G Schneider, EK Stouffer, RJ Terray, L von Storch, JS AF Covey, C Abe-Ouchi, A Boer, GJ Boville, BA Cubasch, U Fairhead, L Flato, GM Gordon, H Guilyardi, E Jiang, X Johns, TC Le Treut, H Madec, G Meehl, GA Miller, R Noda, A Power, SB Roeckner, E Russell, G Schneider, EK Stouffer, RJ Terray, L von Storch, JS TI The seasonal cycle in coupled ocean-atmosphere general circulation models SO CLIMATE DYNAMICS LA English DT Article ID SURFACE AIR-TEMPERATURE; SPATIAL VARIABILITY; CLIMATE SENSITIVITY; CO2; INCREASE; PROJECT; LAYER AB We examine the seasonal cycle of near-surface air temperature simulated by 17 coupled ocean-atmosphere general circulation models participating in the Coupled Model Intercomparison Project (CMIP). Nine of the models use ad hoc "flux adjustment" at the ocean surface to bring model simulations close to observations of the present-day climate. We group flux-adjusted and non-flux-adjusted models separately and examine the behaviol- of each class. When averaged over all of the flux-adjusted model simulations, near-surface air temperature falls within 2 K of observed values over the oceans. The corresponding average over non-flux-adjusted models shows errors up to similar to6 K in extensive ocean areas. Flux adjustments are not directly applied over land, and near-surface land temperature errors are substantial in the average over flux-adjusted models, which systematically underestimates (by similar to5 K) temperature in areas of elevated terrain. The corresponding average over non-flux-adjusted models forms a similar error pattern (with somewhat increased amplitude) over land. We use the temperature difference between July and January to measure seasonal cycle amplitude. Zonal means of this quantity from the individual flux-adjusted models form a fairly tight cluster (all within similar to 30% of the mean) centered on the observed values. The nonflux-adjusted models perform nearly as well at most latitudes. In Southern Ocean mid-latitudes, however, the non-flux-adjusted models overestimate the magnitude of January-minus-July temperature differences by similar to5 K due to an overestimate of summer (January) near-surface temperature. This error is common to five of the eight non-flux-adjusted models. Also, over Northern Hemisphere mid-latitude land areas, zonal mean differences between July and January temperatures simulated by the non-flux-adjusted models show a greater spread (positive and negative) about observed values than results from the flux-adjusted models. Elsewhere, differences between the two classes of models are less obvious. At no latitude is the zonal mean difference between averages over the two classes of models greater than the standard deviation over models. The ability of coupled GCMs to simulate a reasonable seasonal cycle is a necessary condition for confidence in their prediction of long-term climatic changes (such as global warming), but it is not a sufficient condition unless the seasonal cycle and long-term changes involve similar climatic processes. To test this possible connection, we compare seasonal cycle amplitude with equilibrium warming under doubled atmospheric carbon dioxide for the models in our data base. A small but positive correlation exists between these two quantities. This result is predicted by a simple conceptual model of the climate system, and it is consistent with other modeling experience, which indicates that the seasonal cycle depends only weakly on climate sensitivity. C1 Univ Calif Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Livermore, CA 94550 USA. Ctr Climate Syst Res, Tokyo 153, Japan. Canadian Ctr Climate Modeling & Anal, Victoria, BC V8W 2Y2, Canada. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. German Climate Comp Ctr, D-20146 Hamburg, Germany. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. CNRS, Meteorol Dynam Lab, F-75252 Paris 05, France. CSIRO, Div Atmospher Res, Mordialloc, Vic 3195, Australia. CERFACS, Climate Modeling & Global Change Team, F-31057 Toulouse, France. Goddard Inst Space Studies, New York, NY 10025 USA. UK Meteorol Off, Hadley Ctr, Bracknell RG12 2SY, Berks, England. Lab Dynam Oceanog & Climatol, F-75252 Paris 05, France. Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. Bur Meteorol Res Ctr, Melbourne, Vic 3001, Australia. Ctr Ocean Land Atmosphere Studies, Calverton, MD 20705 USA. Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Hamburg, Inst Meteorol, D-20146 Hamburg, Germany. RP Covey, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Mail Code L-264, Livermore, CA 94550 USA. RI madec, gurvan/E-7825-2010; Guilyardi, Eric/D-4868-2011; Abe-Ouchi, Ayako/M-6359-2013; Flato, Gregory/K-6711-2015; Terray, Laurent/B-8056-2008 OI madec, gurvan/0000-0002-6447-4198; Guilyardi, Eric/0000-0002-2255-8625; Abe-Ouchi, Ayako/0000-0003-1745-5952; Terray, Laurent/0000-0001-5512-7074 NR 33 TC 32 Z9 35 U1 1 U2 8 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD OCT PY 2000 VL 16 IS 10-11 BP 775 EP 787 DI 10.1007/s003820000081 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 368LD UT WOS:000090117700004 ER PT J AU Rumminger, MD Linteris, GT AF Rumminger, MD Linteris, GT TI The role of particles in the inhibition of premixed flames by iron pentacarbonyl SO COMBUSTION AND FLAME LA English DT Article ID OXIDE-SILICA NANOCOMPOSITES; SIZE DISTRIBUTION FUNCTION; VAPOR-PHASE SYNTHESIS; DIFFUSION FLAMES; SHOCK-WAVES; HOMOGENEOUS NUCLEATION; AEROSOL-PARTICLES; METAL VAPORS; SOOT; CONDENSATION AB Laser light scattering has been used to investigate particle formation in Fe(CO)(5)-inhibited premixed flames in order to understand the influence of metal and metal oxide condensation on flame inhibition. In premixed CH4-air flames, particles form early in the flame zone, nucleate and grow to a peak scattering cross section, then disappear as the temperature increases to its peak value. Downstream in the postcombustion gases, the peak scattering signal is several orders of magnitude larger than the peak value near the main reaction zone of the flame. Thermophoretic particle sampling and numerical estimates indicate nanoparticles with diameters between 10 and 30 nm. As the mole fraction of iron pentacarbonyl in the flame is increased, a concentration is reached at which both the burning velocity becomes constant and particle nucleation begins. A model of an ideal heterogeneous inhibitor shows that radical recombination on particle surfaces alone cannot account for the magnitude of the observed inhibition. Measurements in three CO-H-2 flames with similar adiabatic flame temperatures but different burning velocities demonstrate the importance of residence time for particle formation in premixed flames. (C) 2000 by The Combustion Institute. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Linteris, GT (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 68 TC 22 Z9 23 U1 0 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD OCT PY 2000 VL 123 IS 1-2 BP 82 EP 94 DI 10.1016/S0010-2180(00)00153-X PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 357AJ UT WOS:000089476100005 ER PT J AU Mell, P Marks, D McLarnon, M AF Mell, P Marks, D McLarnon, M TI A denial-of-service resistant intrusion detection architecture SO COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING LA English DT Article DE intrusion detection; denial of service; security architecture; mobile agents; computer security AB As the capabilities of intrusion detection systems (IDSs) advance, attackers may disable organizations' IDSs before attempting to penetrate more valuable targets. To counter this threat, we present an IDS architecture that is resistant to denial-of-service (DOS) attacks. The architecture frustrates attackers by making IDS components invisible to attackers' normal means of "seeing" in a network. Upon a successful attack, the architecture allows IDS components to relocate from attacked hosts to operational hosts thereby mitigating the attack. These capabilities are obtained by using mobile agent technology, utilizing network topology features, and by restricting the communication allowed between different types of IDS components. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Comp Secur Div, Gaithersburg, MD 20899 USA. RP Mell, P (reprint author), Natl Inst Stand & Technol, Comp Secur Div, 100 Bur Dr,Stop 8930, Gaithersburg, MD 20899 USA. NR 12 TC 13 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1389-1286 J9 COMPUT NETW JI Comput. Netw. PD OCT PY 2000 VL 34 IS 4 BP 641 EP 658 DI 10.1016/S1389-1286(00)00141-9 PG 18 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 352FH UT WOS:000089203500008 ER PT J AU Ralls, K Taylor, BL AF Ralls, K Taylor, BL TI Better policy and management decisions through explicit analysis of uncertainty: New approaches from marine conservation - Introduction SO CONSERVATION BIOLOGY LA English DT Editorial Material C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Ralls, K (reprint author), Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. NR 4 TC 7 Z9 9 U1 0 U2 3 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1240 EP 1242 DI 10.1046/j.1523-1739.2000.99408.x PG 3 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800009 ER PT J AU Taylor, BL Wade, PR De Master, DP Barlow, J AF Taylor, BL Wade, PR De Master, DP Barlow, J TI Incorporating uncertainty into management models for marine mammals SO CONSERVATION BIOLOGY LA English DT Article ID EASTERN TROPICAL PACIFIC; DOLPHIN STENELLA; CONSERVATION; MORTALITY; POWER; SIZE AB Good management models and good models for understanding biology differ in basic philosophy. Management models must facilitate management decisions despite large amounts of uncertainty about the managed populations. Such models must be based on parameters that can be estimated readily must explicitly account for uncertainty, and should be simple to understand and implement In contrast biological models are designed to elucidate the workings of biology,and should not be constrained by management concerns. We illustrate the need to incorporate uncertainty in management models by reviewing the inadequacy of using standard biological models to manage marine mammals in the United States. Past management was based on a simple model that, although it may have represented population dynamics adequately,failed as a management tool because the parameter that triggered management action was extremely difficult to estimate for the majority of populations. Uncertainty in parameter estimation resulted in few conservation actions We describe a recently adopted management scheme that incorporates uncertainty and its resulting implementation. The approach used in this simple management scheme, which was tested by using simulation models, incorporates uncertainty and mandates monitoring abundance and human-caused mortality. Although the entire scheme may be suitable for application to some terrestrial and marine problems, two features are broadly applicable: the incorporation of uncertainty through simulations of management and the use of quantitative management criteria to translate verbal objectives into levels of acceptable risk. C1 SW Fisheries Sci Ctr, La Jolla, CA 93028 USA. Natl Marine Mammal Lab, Natl Marine Fisheries Serv, Off Protected Resources, St Paul, MN 55108 USA. RP Taylor, BL (reprint author), SW Fisheries Sci Ctr, 8604 La Jolla Shores Dr, La Jolla, CA 93028 USA. NR 48 TC 73 Z9 79 U1 2 U2 15 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1243 EP 1252 DI 10.1046/j.1523-1739.2000.99409.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800010 ER PT J AU Slooten, E Fletcher, D Taylor, BL AF Slooten, E Fletcher, D Taylor, BL TI Accounting for uncertainty in risk assessment: Case study of Hector's dolphin mortality due to gillnet entanglement SO CONSERVATION BIOLOGY LA English DT Article ID POPULATION VIABILITY ANALYSIS; EXTINCTION RISKS; BANKS-PENINSULA; NEW-ZEALAND; CONSERVATION; SENSITIVITY; SURVIVAL AB Uncertainties about biological data and human effects often delay decisions on management of endangered species Some decision makers argue that uncertainty about the risk posed to a species should lead to precautionary decisions whereas others argue for delaying protective measures until there Is strong evidence that a human activity Is having a serious effect on the species. We have developed a method that incorporates uncertainty into the estimate of risk so that delays in action can be reduced or eliminated We illustrate our method with an actual situation of a deadlock over how to manage Hector's dolphin (Cephalorhychus hectori). The management question is whether sufficient risk is posed to the dolphins by mortalities in gillnets to warrant regulating the fisheries. In our quantitative risk assessment, we use a population model that incorporates both demographic (between-individual) and environmental (between year) stochasticity. We incorporate uncertainty in estimates of model parameters by repeatedly running the model for different combinations of survival and reproductive rates. Each value is selected at random from a probability distribution that represents the uncertainty in estimating that parameter. Before drawing conclusions, we perform sensitivity analyses to see whether model assumptions alter conclusions and to recommend priorities for future research. In this example, uncertainty did not alter the conclusion that there is a high risk of population decline if current levels of gillnet mortality continue. Sensitivity analyses revealed this to be a robust conclusion. Thus our analysis removes uncertainty in the scientific data ns an excuse for inaction. C1 Univ Otago, Dept Math & Stat, Dundee, Scotland. SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Slooten, E (reprint author), Univ Otago, Dept Math & Stat, Dundee, Scotland. EM liz.slooten@stonebow.otago.ac.nz RI Slooten, Elisabeth/E-7425-2014 OI Slooten, Elisabeth/0000-0001-5384-511X NR 29 TC 50 Z9 55 U1 4 U2 31 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1264 EP 1270 DI 10.1046/j.1523-1739.2000.00099-411.x PG 7 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800012 ER PT J AU Forney, KA AF Forney, KA TI Environmental models of cetacean abundance: Reducing uncertainty in population trends SO CONSERVATION BIOLOGY LA English DT Article ID STATISTICAL POWER; DETECTING TRENDS; HARBOR PORPOISE; CALIFORNIA; FISHERIES; DOLPHINS; WATERS AB Trends in population abundance are often used to monitor species affected by human activities For highly mobile species in dynamic environments, however such as cetaceans in the marine realm, natural variability can confound attempts to detect and interpret trends in abundance. Environmental variability can cause dramatic shifts in the distribution of cetaceans, and thus abundance estimates for a fixed region may be based on a different proportion of the population each time. This adds variability decreasing statistical power to detect trends and introducing uncertainty whether apparent trends represent true changes in population size or merely reflect natural changes in the distribution of cetaceans To minimize these problems, surveys ideally would be based on species-specific design criteria that optimize sampling within all relevant habitat throughout a species' range. Our knowledge of cetacean habitats is limited how ever, and financial and logistic constraints generally force those surveying cetacean abundance to include an species within a limited geographic region. Alternately, it may be possible to account for environmental variability analytically by including models of species-environment patterns in trend analyses, bur this will be successful only if such models have interannual predictive power. I developed and evaluated generalized additive models of cetacean sighting rates in relation to environmental variables. I used data from shipboard surveys of Dall's porpoise (Phocoenoides dalli) and short-beaked common dolphins (Delphinus delphis) conducted in 1991, 1993, and 1996 off California. Sighting rates for these two species are variable and can be partially accounted for by environmental models, but additional surveys are needed to model species-environment relationships adequately. If patterns are consistent across years, generalized additive models may represent an effective tool for reducing uncertainty caused by environmental variability and for improving our ability to detect and interpret trends in abundance. C1 Nat Marine Fisheries Soc, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Forney, KA (reprint author), SW Fisheries Sci Ctr, 110 Shaffer Rd, Santa Cruz, CA 95060 USA. NR 36 TC 80 Z9 86 U1 1 U2 17 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1271 EP 1286 DI 10.1046/j.1523-1739.2000.99412.x PG 16 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800013 ER PT J AU Taylor, BL Chivers, SJ Sexton, S Dizon, AE AF Taylor, BL Chivers, SJ Sexton, S Dizon, AE TI Evaluating dispersal estimates using mtDNA data: Comparing analytical and simulation approaches SO CONSERVATION BIOLOGY LA English DT Article ID HUMAN MITOCHONDRIAL-DNA; GENE FLOW; POPULATION-STRUCTURE; CONSERVATION; DEMOGRAPHY; POWER AB Using genetic data to estimate dispersal is attractive because direct estimation is often infeasible. Unfortunately, analytical tools remain rudimentary. Various standard population genetic formulae estimate dispersal rates between populations but require unrealistic assumptions,such as equal population size. Recent increases in computer speed enable simulations of genetic processes in populations We designed stimulation models to evaluate the adequacy of using analytical formulae to estimate dispersal rates needed for conservation decisions Our models incorporated genetic stochasticity They adhered closely to the assumptions of the standard formulae except that we relaxed the assumption that all populations were equal in size. We found that measures of population differentiation, such as the statistic Phi(ST), varied greatly over time, reflecting the stochastic nature of genetic systems, lit some cases, however, even large amounts of variation over time made no difference in defining population structure for management purposes whereas in other cases the opposite was true. Statistics of genetic differentiation were so variable that management decisions based on analytical formulae would often be incorrect. Adjoining populations with little dispersal between them that should be managed separately were by chance alone so genetically similar that they appear panmictic, incorrectly implying that they should be managed as a single unit The form of distributions of these statistics was complex and did not conform to standard statistical distributions Furthermore, differences between these distributions for equal and unequal abundance cases indicated that pursuits of simple adjustments to analytical formulae are unlikely to be fruitful. In contrast, our simulation technique can be used in a decision analysis framework: because it incorporates uncertainties into a probability distribution. We conclude with a case in which a manager wants to know whether current human-caused mortality levels can be sustained while maintaining the local population at healthy levels. The example demonstrates how decision analysis for population structure can use the probability distributions generated from simulations to incorporate uncertainty and estimate over- and underprotection errors. C1 SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Taylor, BL (reprint author), SW Fisheries Sci Ctr, 8604 La Jolla Shore Dr, La Jolla, CA 92038 USA. NR 27 TC 11 Z9 12 U1 1 U2 3 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1287 EP 1297 DI 10.1046/j.1523-1739.2000.99413.x PG 11 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800014 ER PT J AU Wade, PR AF Wade, PR TI Bayesian methods in conservation biology SO CONSERVATION BIOLOGY LA English DT Article ID STATISTICAL POWER ANALYSIS; IMPORTANCE RESAMPLING ALGORITHM; STOCK ASSESSMENT; BOWHEAD WHALES; INFERENCE; FISHERIES; UNCERTAINTY; MANAGEMENT; PARAMETERS; MODEL AB Bayesian statistical inference provides an alternate way to analyze data that is likely to be more appropriate to conservation biology problems than traditional statistical methods. I contrast Bayesian techniques with traditional hypothesis-testing techniques using examples applicable to conservation. I use a trend analysis of two hypothetical populations to illustrate how easy it is to understand Bayesian results, which are given in terms of probability Bayesian trend analysis indicated that the two populations had very different chances of declining at biologically important rates. For example, the probability that the first population was declining faster than 5% per year was 0.00, compared to a probability of 0.86 for the second population. The Bayesian results appropriately identified which population was of greater conservation concern. The Bayesian results contrast with those obtained with traditional hypothesis testing Hypothesis testing indicated that the first population, which the Bayesian analysis indicated had no chance of declining at >5% per year, was declining significantly because it was declining at a slow rate and the abundance estimates were precise. Despite the high probability that the second population was experiencing a serious decline, hypothesis testing failed to reject the null hypothesis of no decline because the abundance estimates were imprecise. Finally, I extended the trend analysis to illustrate Bayesian decision theory, which allows for choice between more than two decisions and allows explicit specification of the consequences of various errors. The Bayesian results again differed from the traditional results: the decision analysis led to the conclusion that the first population was declining slowly and the second population was declining rapidly. C1 Natl Marine Mammal Lab, Natl Marine Fisheries Serv, Off Protected Resources, Seattle, WA 98155 USA. RP Wade, PR (reprint author), Natl Marine Mammal Lab, Natl Marine Fisheries Serv, Off Protected Resources, 7600 Sand Point Way NE, Seattle, WA 98155 USA. NR 54 TC 143 Z9 148 U1 2 U2 34 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1308 EP 1316 DI 10.1046/j.1523-1739.2000.99415.x PG 9 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800016 ER PT J AU Kalinowski, ST Hedrick, PW Miller, PS AF Kalinowski, ST Hedrick, PW Miller, PS TI Inbreeding depression in the Speke's gazelle captive breeding program SO CONSERVATION BIOLOGY LA English DT Article ID MAMMALIAN POPULATIONS; PEROMYSCUS-POLIONOTUS; GENETIC-VARIATION; ELIMINATION; SELECTION AB The Speke's gazelle (Gazella spekei) captive breeding program has been presented as one of the few examples of selection reducing the genetic load of a population and as a potential model for the captive breeding of endangered species founded from a small number of individuals. In this breeding program, three generations of mate selection apparently increased the viability of inbred individuals. We reanalyzed the Speke's gazelle studbook and examined potential causes for the reduction of inbreeding depression. Our analysis indicates that the decrease in inbreeding depression is not consistent with any model of genetic improvement in the herd. Instead, we found that the effect of inbreeding decreased from severe to moderate during the first generation of inbreeding, and that this change is responsible for almost all of the decline in inbreeding depression observed during the breeding program, This eliminates selection as a potential explanation for the decrease in inbreeding depression and suggests that inbreeding depression may be more sensitive to environmental influences than is usually thought. C1 Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. Conservat Breeding Specialist Grp, Apple Valley, MN 55124 USA. RP Kalinowski, ST (reprint author), NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Kalinowski, Steven/A-7607-2008 NR 33 TC 40 Z9 42 U1 2 U2 21 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1375 EP 1384 DI 10.1046/j.1523-1739.2000.98209.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800027 ER PT J AU Amorim, AF Arfelli, CA Castro, JI AF Amorim, AF Arfelli, CA Castro, JI TI Description of a juvenile megamouth shark, Megachasma pelagios, caught off Brazil SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE Chondrichthyes; Megachasmidae; elasmobranch; new record; Atlantic; morphometrics AB A juvenile male megamouth shark was caught by a commercial longline vessel off Brazil. This specimen is the only juvenile megamouth examined and the only one from the Atlantic Ocean. Megamouth shark is one of the rarest sharks in the world. Only 14 specimens have been reported since its description in 1983 by Taylor et al. All previous specimens examined have been adults from the Pacific and Indian Oceans. It appears that the species is cosmopolitan. C1 Inst Pesca, BR-11030906 Santos, SP, Brazil. NOAA, NMFS, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Mote Marine Lab, Ctr Shark Res, Sarasota, FL 34236 USA. RP Amorim, AF (reprint author), Inst Pesca, Av Bartolomeu de Gusmao 192, BR-11030906 Santos, SP, Brazil. NR 14 TC 5 Z9 7 U1 1 U2 5 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 OCT PY 2000 VL 59 IS 2 BP 117 EP 123 DI 10.1023/A:1007609617773 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 351DR UT WOS:000089143000001 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Effects of group membership and size distribution within a group on growth rates of juvenile sablefish Anoplopoma fimbria SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE fish behavior; schooling; size disparity; density; growth; food availability ID SALVELINUS-ALPINUS L; ARCTIC CHARR; GASTEROSTEUS-ACULEATUS; SOCIAL CONSTRAINTS; ONCORHYNCHUS-KETA; FOOD DISTRIBUTION; ATLANTIC SALMON; RAINBOW-TROUT; CHUM SALMON; CANNIBALISM AB Group membership can confer both advantages and disadvantages to growth in juvenile fishes. The balance between costs and benefits of social interactions can shift depending on such factors as the composition of the group (density and size disparity) and the availability of food. We examined the effect of these factors on absolute growth and growth depensation in juvenile sablefish, Anoplopoma fimbria. Increasing density and increasing size disparity had little influence on absolute growth rates of juvenile sablefish and the effects of these social factors were not modified by ration level. In experiments testing density effects, absolute growth did not differ among groups of 1, 3, or 10 fish held at high rations, but at low rations single fish exhibited a different pattern of size-dependent growth compared to fish in groups. In experiments testing disparity effects, absolute growth did not differ between groups with an even size distribution and groups with a mixed size distribution. The relative size of an individual within a group, i.e., small, medium, or large, also did not modify growth, despite evidence of higher chasing behavior in mixed size distributions. Although the growth of small fish was not diminished in the presence of large fish, negative impacts of size disparity were expressed in high levels of cannibalism, which occurred in 42% of groups with a mixed size distribution. Significant growth depensation over time occurred in the density experiment, but not in the size disparity experiment, possibly due to the shorter duration of the latter experiment. We suggest that growth depensation was generated by individual variability in growth capacity rather than social effects on growth rates. Schooling behavior, measured by group cohesion indices, increased with fish size and was higher in groups with an even vs. a mixed size distribution. These results for sablefish are consistent with other schooling species in which growth variability is determined by exploitative competition and/or genetic variability in growth capacity rather than interference competition. C1 Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NR 54 TC 13 Z9 15 U1 4 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD OCT PY 2000 VL 59 IS 2 BP 199 EP 209 DI 10.1023/A:1007659903444 PG 11 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 351DR UT WOS:000089143000008 ER PT J AU Kang, WJ Trefry, JH Nelsen, TA Wanless, HR AF Kang, WJ Trefry, JH Nelsen, TA Wanless, HR TI Direct atmospheric inputs versus runoff fluxes of mercury to the lower Everglades and Florida Bay SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID RECENT SEDIMENTATION; LAKE-MICHIGAN; DEPOSITION; PB-210; RIVER; CONTAMINATION; GEOCHRONOLOGY; MINNESOTA; STATES; MARINE AB Age-dated sediments from the lower Everglades and Florida Bay provide a record of inputs of excess Hg from direct atmospheric input versus runoff. Direct atmospheric fluxes of excess Hg to sediments in the lower Everglades and Florida Bay, calculated using a mass balance model tar excess Pb-210, currently average 24 +/- 9 mu g m(-2) yr(-1) and are comparable with recent results from bulk atmospheric deposition. in contrast, present-day runoff fluxes of excess Hg to area sediments are variable, ranging from about 4-160 mu g m(-2) yr(-1). The runoff flux now carries 60-80% of the total flux of excess Hg to the sediments in areas near river sloughs but less than 20% of the total flux of excess Hg in more remote areas of Florida Bay. These results show the greater importance of runoff relative to direct atmospheric deposition for Hg inputs to many areas of the lower Everglades and immediately adjacent Florida Bay. Thus, the choice of future water management strategies can play an important role in controlling Hg inputs to the lower Everglades and portions of Florida Bay. C1 Florida Inst Technol, Div Marine & Environm Syst, Melbourne, FL 32901 USA. Univ Miami, Dept Geol Sci, Coral Gables, FL 33124 USA. NOAA, Atlantic Oceanog & Meteorol Lab, OCD, Miami, FL 33149 USA. RP Trefry, JH (reprint author), Florida Inst Technol, Div Marine & Environm Syst, 150 W Univ Blvd, Melbourne, FL 32901 USA. OI Trefry, John/0000-0002-8451-5524 NR 40 TC 20 Z9 23 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT 1 PY 2000 VL 34 IS 19 BP 4058 EP 4063 DI 10.1021/es0010608 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 359HB UT WOS:000089604500018 ER PT J AU Long, ER MacDonald, DD Severn, CG Hong, CB AF Long, ER MacDonald, DD Severn, CG Hong, CB TI Classifying probabilities of acute toxicity in marine sediments with empirically derived sediment quality guidelines SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE sediment quality guidelines; sediment toxicity AB Matching, marine sediment chemistry, and toxicity data (n = 1,513), compiled from three studies conducted in the United States, were analyzed to determine both the frequency of acute toxicity to amphipods and average percentage survival in laboratory bioassays within ranges in toxicant concentrations. We determined that the probability of observing acute toxicity was relatively low (<10%) and that average control-adjusted survival equaled or exceeded 92% in samples in which sediment quality guidelines were not exceeded. Both the incidence of toxicity increased and average survival decreased as chemical concentrations increased relative to the guidelines. In sediments with highest contaminant concentrations, 73 to 83% of the samples were highly toxic, and average control-adjusted amphipod survival was 37 to 46%. Results of this study confirm that the relationships between sediment chemical concentrations and toxicity reported in a previous study were robust. Further, they indicate that numerical guidelines for saltwater sediments can be used to estimate the probability of observing toxic effects in acute amphipod tests. C1 NOAA, Natl Ctr Coastal Ocean Sci, Seattle, WA 98115 USA. MacDonald Environm Sci Ltd, Nanaimo, BC V9X 1W5, Canada. EVS Environm Consultants, Seattle, WA 98119 USA. RP Long, ER (reprint author), NOAA, Natl Ctr Coastal Ocean Sci, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 9 TC 127 Z9 129 U1 7 U2 18 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD OCT PY 2000 VL 19 IS 10 BP 2598 EP 2601 DI 10.1897/1551-5028(2000)019<2598:CPOATI>2.3.CO;2 PG 4 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 360PN UT WOS:000089676600028 ER PT J AU Cotner, JB Sada, RH Bootsma, H Johengen, T Cavaletto, JF Gardner, WS AF Cotner, JB Sada, RH Bootsma, H Johengen, T Cavaletto, JF Gardner, WS TI Nutrient limitation of heterotrophic bacteria in Florida Bay SO ESTUARIES LA English DT Article ID DISSOLVED ORGANIC-CARBON; N-P RATIOS; BACTERIOPLANKTON PRODUCTION; FRESH-WATER; MARINE BACTERIOPLANKTON; PHOSPHORUS LIMITATION; THALASSIA-TESTUDINUM; MICROBIAL PLANKTON; GROWTH; PHYTOPLANKTON AB We examined heterotrophic bacterial nutrient limitation at four sites in Florida Bay, U.S. in summer 1994 and winter 1995. Bacterial growth and biomass production in this system were most limited by inorganic phosphorus (P) in the eastern and southern regions of the bay. Nutrient additions stimulated productivity and biomass accumulation mostly in summer. The magnitude of growth responses (thymidine incorporation) to nutrient additions was nearly an order of magnitude less in winter than summer. Biomass-normalized alkaline phosphatase activity in the northeast and south-central region was 5-20 times greater than in the northwest and north-central regions, suggesting that P is most limiting to planktonic growth in those areas. Chlorophyll levels were higher in the northwest and north-central regions and P-uptake into particles > 1 mum, primarily phytoplankton, was also higher in these regions. Consistent with these observations, others have observed that P is advected into the bay primarily in the northwestern region. Abundant seagrasses in Florida Bay may promote heterotrophic bacterial production relative to phytoplankton production by releasing dissolved organic carbon that makes bacteria more competitive for limiting quantities of inorganic phosphate, especially in the eastern bay where turbidity is low, P is most limiting, and light levels reaching the benthic plants are high. C1 Texas A&M Univ, Dept Fisheries & Wildlife Sci, College Stn, TX 77843 USA. Univ Wisconsin, Great Lakes Water Inst, Milwaukee, WI 53204 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Texas, Inst Marine Sci, Port Aransas, TX 78373 USA. RP Cotner, JB (reprint author), Univ Minnesota, Dept Ecol Evolut & Behav, 1987 Upper Buford Circle, St Paul, MN 55108 USA. NR 52 TC 46 Z9 50 U1 1 U2 15 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD OCT PY 2000 VL 23 IS 5 BP 611 EP 620 DI 10.2307/1352888 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 383QH UT WOS:000165893500002 ER PT J AU Brodziak, J Mikus, R AF Brodziak, J Mikus, R TI Variation in life history parameters of Dover sole, Microstomus pacificus, off the coasts of Washington, Oregon, and northern California SO FISHERY BULLETIN LA English DT Article ID FLATFISHES; PATTERNS; MATURITY; CLIMATE; FISHES; GROWTH AB Variation in the life history parameters of Dover sole (Microstomus pacificus) off the coasts of Washington, Oregon, and northern California was investigated by using research survey data. We compared growth, maturation, and length-weight curves of Dover sole within the International North Pacific Fisheries Commission (INPFC) statistical areas of Monterey, Eureka, Columbia, and Vancouver. We found strong evidence of dimorphism in growth and maturation rates between sexes. In addition, geographic variation in both growth and maturation rates was also suggested. Male and female Dover sole from the Columbia area had lower Brody growth coefficients and larger asymptotic lengths than Dover sole from other areas. Further; there was an apparent latitudinal dine in maturation rates because males and females matured at smaller size and younger ages at higher latitudes. In contrast, no difference between male and female length-weight relationships was detected. In comparison with other pleuronectids, we found that Dover sole matured at relatively larger sizes and younger ages. These differences likely reflect adaptation of Dover sole to the inherent variability of the California Current. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. Hatfield Marine Sci Ctr, Oregon Dept Fish & Wildlife, Newport, OR 97365 USA. RP Brodziak, J (reprint author), NW Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 40 TC 14 Z9 15 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 661 EP 673 PG 13 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100001 ER PT J AU Gledhill, CT Lyczkowski-Shultz, J AF Gledhill, CT Lyczkowski-Shultz, J TI Indices of larval king mackerel (Scomberomorus cavalla) abundance in the Gulf of Mexico for use in population assessments SO FISHERY BULLETIN LA English DT Article ID OF-MEXICO; FISHERIES MANAGEMENT; UNITED-STATES; NORTH-SEA; FISH; GROWTH; VARIABILITY; JUVENILES; FECUNDITY; AGE AB The stock status of the Gulf of Mexico migratory group of king mackerel (Scomberomorus cavalla) is currently evaluated by using age-based sequential virtual population analysis (VPA). We examined king mackerel larval occurrence and abundance indices from annual ichthyoplankton surveys, developed an age-adjusted abundance index, and questioned whether larval indices of abundance are useful for calibrating the king mackerel VPA. Gulf of Mexico king mackerel larval occurrence and abundance increased over a fourteen-year time series from 1982 to 1995 and were highly correlated with spawning stock size. Correlations between stock size and larval occurrence, and between stock size and larval abundance,were 0.82 and 0.84, respectively. The correlation between larval occurrence and stock size for the years 1986-35 increased to 0.91, owing to the addition in 1986 of a fall survey with added coverage during peak spawning. Daily instantaneous mortality rate (Z) was estimated by regression of larval catch curves. Although a large amount of interannual variability in mortality rates was noted, no statistical differences were detected among years. The instantaneous daily mortality rate estimated by pooling all years, Z = 0.53, was used to develop an age-adjusted index for king mackerel in order to eliminate the influence of variable larval age composition among years. This adjusted index did not improve correlations between stock size and larval abundance (r=0.78). For now, indices of larval occurrence and unadjusted larval abundance from ichthyoplankton collections reflect trends in spawning stock size and provide useful variables for calibrating the king mackerel VPA. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Pascagoula, MS 39568 USA. RP Gledhill, CT (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 3209 Frederic St, Pascagoula, MS 39568 USA. NR 32 TC 9 Z9 10 U1 1 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 684 EP 691 PG 8 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100003 ER PT J AU Hoff, GR AF Hoff, GR TI Biology and ecology of threaded sculpin, Gymnocanthus pistilliger, in the eastern Bering Sea SO FISHERY BULLETIN LA English DT Article AB The threaded sculpin (Gymnocanthus pistilliger) is distributed in the North Pacific from Norton Sound south to Southeast Alaska and west to Russia and Japan. It reaches its greatest abundance in the eastern Bering Sea in Bristol Bay where it is typically found in waters less than 50 m deep. Alaska Fisheries Science Center groundfish surveys in the eastern Bering Sea have estimated densities of up to 102 fish per hectare (catch per unit of effort, CPUE) for 1997 and 1998. Population estimates for 1997 were 111.20 million and for 1998 were 51.70 million. The population estimate drop is reflected in length-frequency data that suggest a complete lack of a-year-old fish for 1998. Gymnocanthus pistilliger is a short-lived species (age estimates from otoliths range up to 10 years for males and up to 9 years for females), and the maximum size is 161 mm and 201 mm total length for males and females, respectively During June, when specimen collections were made, ovaries are in the resting stage and contain some residual eggs from a previous spawning. The diet of G. pistilliger changes from predominantly gammarid amphipods and polychaetes to crangonid shrimp and fish with increased total length. Comparisons with studies from the western North Pacific on G. pistilliger suggest biological differences between populations, which may reflect adaptation to different habitats. C1 Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP Hoff, GR (reprint author), Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM jerry.hoff@noaa.gov NR 21 TC 5 Z9 7 U1 1 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 EI 1937-4518 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 711 EP 722 PG 12 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100006 ER PT J AU Lindley, ST Mohr, MS Prager, MH AF Lindley, ST Mohr, MS Prager, MH TI Monitoring protocol for Sacramento River winter chinook salmon, Oncorhynchus tshawytscha: application of statistical power analysis to recovery of an endangered species SO FISHERY BULLETIN LA English DT Article ID POPULATION SIZES; MANAGEMENT; VIABILITY; TRENDS AB when monitoring endangered species, natural resource managers require a recovery benchmark and a statistical procedure to test whether the benchmark has been met. We applied statistical power analysis to devise such a procedure for the endangered Sacramento River winter chinook salmon (Oncorhynchus tshawytscha). Winter chinook salmon management currently focuses on population growth rate, and our procedure used a Student's t-test to evaluate whether the average population growth rate is significantly lower than the management goal of 0.57 per generation. In the test, the null hypothesis was that the growth rate was not lower than the desired rate. In contrast to the usual hypothesis-testing framework, our procedure did not control for the type-I error rate. Instead, it controlled for the statistical power (the complement of the type-II error rate) and uses the resulting type-I error rate, computed from the sample size and other information, for the test. This procedure is conservative for winter chinook salmon in that, if all assumptions are met, it provides the specified level of assurance of detecting dangerously low population growth rates. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, Tiburon, CA 94920 USA. RP Lindley, ST (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, 3150 Paradise Dr, Tiburon, CA 94920 USA. RI Lindley, Steven/G-3997-2014 OI Lindley, Steven/0000-0001-9556-0411 NR 20 TC 5 Z9 5 U1 1 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 759 EP 766 PG 8 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100010 ER PT J AU Wilson, MT AF Wilson, MT TI Effects of year and region on the abundance and size of age-0 walleye pollock, Theragra chalcogramma, in the western Gulf of Alaska, 1985-1988 SO FISHERY BULLETIN LA English DT Article ID COD GADUS-MORHUA; SHELIKOF-STRAIT; FISHERIES OCEANOGRAPHY; OTOLITH ANALYSIS; STRIPED BASS; JUVENILE; LARVAL; RECRUITMENT; MORTALITY; NEWFOUNDLAND AB Effects of year and region on young-of-the-year (age-0) walleye pollock abundance and size were examined by using bottom and midwater trawl collections made during 1985-88. Samples were collected from shelf and coastal areas in three adjacent regions of the western Gulf of Alaska. The primary focus was to examine regional differences in recruitment prediction and annual differences in fish distribution. Fish density was used to indicate abundance, and length was included as a relevant factor in fish production. Year and region significantly interacted as effects on age-0 density. Recruitment prediction was best in the Kodiak Island region, upstream of the main spawning area, where fish densities were high during 1985 and 1988 in relation to 1986 and 1987. On a large scale, fish were evenly distributed every year, except during 1987 when their density increased strongly from east to west. Age-0 length also varied with year and region. This was apparent after accounting for daily increases in mean length (0.09 cm/d). Fish were comparatively small during 1986, intermediate during 1985, and large during 1987 and 1988. Regional differences in fish length were due to a relative abundance of large-size fish around Kodiak Island where the average size was about 0.75 cm larger than elsewhere. Thus, a relative abundance of large individuals in this region was associated with good recruitment prediction. These results are discussed in terms of their relevance to spatial variation in the production of recruits. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Wilson, MT (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point NE, Seattle, WA 98115 USA. NR 63 TC 14 Z9 14 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 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 823 EP 834 PG 12 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100015 ER PT J AU Ignell, S Haynes, E AF Ignell, S Haynes, E TI Geographic patterns in growth of the giant Pacific sea scallop, Patinopecten caurinus SO FISHERY BULLETIN LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Ignell, S (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 29 TC 6 Z9 6 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 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 849 EP 853 PG 5 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100018 ER PT J AU Johnson, DL AF Johnson, DL TI Preliminary examination of the match-mismatch hypothesis and recruitment variability of yellowtail flounder, Limanda ferruginea SO FISHERY BULLETIN LA English DT Article ID FISH C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab Sandy Hook, Highlands, NJ 07732 USA. RP Johnson, DL (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab Sandy Hook, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 18 TC 6 Z9 6 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 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 854 EP 863 PG 10 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100019 ER PT J AU Wing, BL Murphy, JM Rutecki, TL AF Wing, BL Murphy, JM Rutecki, TL TI Occurrence of Pacific sardine, Saudinops sagax, off southeastern Alaska SO FISHERY BULLETIN LA English DT Article C1 Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Wing, BL (reprint author), Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 20 TC 6 Z9 7 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2000 VL 98 IS 4 BP 881 EP 883 PG 3 WC Fisheries SC Fisheries GA 381EV UT WOS:000165750100023 ER PT J AU Kvenberg, J Stolfa, P Stringfellow, D Garrett, ES AF Kvenberg, J Stolfa, P Stringfellow, D Garrett, ES TI HACCP development and regulatory assessment in the United States of America SO FOOD CONTROL LA English DT Article DE HACCP; food safety; critical control points; critical limits; pathogen reduction; regulatory; risk; verification; validation AB Hazard Analysis Critical Control Point (HACCP) is internationally recognized as the best method of assuring product safety by controlling foodborne safety hazards. Currently, within the USA, the FDA has mandated HACCP for fish and fishery products and is proposing mandating HACCP for fruit and vegetable juices. The USDA has mandated Pathogen Reduction/HACCP requirements for meat and poultry processing, and the NMFS Seafood Inspection Program operates a voluntary HACCP program for seafood plants. The requirements for mandatory implementation and proposed regulations represent a significant change in the manner in which foods are regulated for food safety and necessitate a new understanding of the different roles and responsibilities between the food industries and the regulatory agencies within the USA. Each agency will approach the evaluation process differently given their unique legislative authorities and programmatic operations. Nevertheless, each agency agrees that HACCP is the best food control system of choice and is committed to improve food safety requirements. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 US FDA, Div HACCP Programs, HFS 615, Washington, DC 20204 USA. USDA, FSIS, Washington, DC 20250 USA. Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, Pascagoula, MS 39568 USA. RP Kvenberg, J (reprint author), US FDA, Div HACCP Programs, HFS 615, 200 St SW, Washington, DC 20204 USA. NR 30 TC 15 Z9 18 U1 1 U2 11 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-7135 J9 FOOD CONTROL JI Food Control PD OCT PY 2000 VL 11 IS 5 BP 387 EP 401 DI 10.1016/S0956-7135(99)00090-0 PG 15 WC Food Science & Technology SC Food Science & Technology GA 314BL UT WOS:000087034200010 ER PT J AU Murphy, KE Beary, ES Rearick, MS Vocke, RD AF Murphy, KE Beary, ES Rearick, MS Vocke, RD TI Isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS) for the certification of lead and cadmium in environmental standard reference materials SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID SAMPLE INTRODUCTION; SEDIMENT AB Lead(Pb) and cadmium (Cd) have been determined in six new environmental standard reference materials (SRMs) using isotope dilution inductively coupled Plasma mass spectrometry (ID ICP-MS). The SRMs are the following: SRM 1944. New York-New Jersey Waterway Sediment, SRMs 2583 and 2584, Trace Elements in Indoor Dust, Nominal 90 m/kg and 10,000 mg/kg Lead, respectively, SRMs 2586 and 2587, Trace Elements in Soil Containing Lead from Paint, Nominal 500 mg/kg and 3000 mg/kg Lead, respectively, and SRM 2782, Industrial Sludge. The capabilities of ID ICP-MS for the certification of Pb and Cd in these materials are assessed. Sample preparation and ratio measurement uncertainties have been evaluated. Reproducibility and accuracy of the established procedures are demonstrated by determination of gravimetrically prepared primacy standard solutions and by comparison with isotope dilution thermal ionization mass spectrometry, (ID TIMS). Material heterogeneity was readily demonstrated to be the dominant source of uncertainty in the certified values. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Murphy, KE (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8391, Gaithersburg, MD 20899 USA. NR 31 TC 31 Z9 34 U1 0 U2 12 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD OCT PY 2000 VL 368 IS 4 BP 362 EP 370 DI 10.1007/s002160000454 PG 9 WC Chemistry, Analytical SC Chemistry GA 366EC UT WOS:000089991000008 PM 11227505 ER PT J AU Tziperman, E AF Tziperman, E TI Uncertainties in thermohaline circulation response to greenhouse warming SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC CO2; FLUX ADJUSTMENTS; CLIMATE MODEL; OCEAN; SYSTEM AB The uncertainty in the response of the thermohaline circulation to greenhouse forcing due to the use of flux adjustments in coupled ocean-atmosphere models is evaluated. This is done by using a different yet physically justifiable flux adjustment procedure and examining its effect on the thermohaline response to greenhouse forcing in a three dimensional primitive equations coupled ocean atmosphere general circulation model. It is found that while the initial thermohaline circulation weakening is robust, its eventual recovery which is seen in some coupled model simulations may be more sensitive to the details of the flux adjustment procedure and may therefore be less certain. C1 Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. Princeton Univ, Geophys Fluid Dynam Lab, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Tziperman, E (reprint author), Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. NR 14 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2000 VL 27 IS 19 BP 3077 EP 3080 DI 10.1029/2000GL006108 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 361FG UT WOS:000089711900013 ER PT J AU McCaffrey, R Long, MD Goldfinger, C Zwick, PC Nabelek, JL Johnson, CK Smith, C AF McCaffrey, R Long, MD Goldfinger, C Zwick, PC Nabelek, JL Johnson, CK Smith, C TI Rotation and plate locking at the southern Cascadia subduction zone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEFORMATION; WASHINGTON; OREGON; EARTHQUAKES; MOTION; MODEL AB Global Positioning System vectors and surface tilt rates are inverted simultaneously for the rotation of western Oregon and plate locking on the southern Cascadia subduction thrust fault. Plate locking appears to be largely offshore, consistent with earlier studies, and is sufficient to allow occasional great earthquakes inferred from geology. Clockwise rotation of most of Oregon about a nearby pole is likely driven by collapse of the Basin and Range and results in shortening in NW Washington State. The rotation pole lies along the Olympic - Wallowa Lineament and explains the predominance of extension south of the pole and contraction north of it. C1 Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY 12180 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97330 USA. Natl Geodet Survey, Salem, OR 97309 USA. Seafloor Surveys Int, Seattle, WA 98121 USA. RP McCaffrey, R (reprint author), Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY 12180 USA. RI Long, Maureen/A-1383-2009; Wright, Dawn/A-4518-2011 OI Long, Maureen/0000-0003-1936-3840; Wright, Dawn/0000-0002-2997-7611 NR 24 TC 108 Z9 110 U1 1 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2000 VL 27 IS 19 BP 3117 EP 3120 DI 10.1029/2000GL011768 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 361FG UT WOS:000089711900023 ER PT J AU Murphy, DM Thomson, DS AF Murphy, DM Thomson, DS TI Halogen ions and NO+ in the mass spectra of aerosols in the upper troposphere and lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CHLORINE; PARTICLES; IODINE AB Mass spectra of individual aerosol particles were acquired at altitudes up to 19 km during the WE-57 Aerosol Mission. Fluorine and chlorine were more abundant in tropospheric aerosols than in stratospheric aerosols. Chlorine in tropospheric aerosols was often associated with organics, soot, and mineral dust. Small amounts of perchlorate were observed in stratospheric sulfate aerosols, but aerosols do not represent a significant sink for total fluorine or chlorine in the lower stratosphere. Bromine was most common in aerosols just above the tropopause. where it may represent a significant fraction of inorganic Br. Both bromine and iodine were highly correlated with organics and probably were present in particles with HE. The OH- and NO+ peak areas increased at temperatures below 195 K, providing evidence for the uptake of H2O and HNO3 by aerosols near a cold tropopause. There was evidence for uptake of chlorine but not the other halogens below 190 K. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Murphy, DM (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. RI Murphy, Daniel/J-4357-2012 OI Murphy, Daniel/0000-0002-8091-7235 NR 21 TC 37 Z9 40 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2000 VL 27 IS 19 BP 3217 EP 3220 DI 10.1029/1999GL011267 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 361FG UT WOS:000089711900048 ER PT J AU McConnaughey, RA Mier, KL Dew, CB AF McConnaughey, RA Mier, KL Dew, CB TI An examination of chronic trawling effects on soft-bottom benthos of the eastern Bering Sea SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International-Council-for-the-Exploration-of-the-Sea Symposium on Marine Benthos Dynamics: Environmental and Fisheries Impacts CY OCT 05-07, 1998 CL INST MARINE BIOL CRETE, IRAKLION, GREECE SP Int Council Explorat Sea, DGXII, DGXIV, Greek Gen Secretariat Res & Technol HO INST MARINE BIOL CRETE DE anthropogenic disturbance; Bering Sea; bottom trawls; macrofauna; soft-bottom benthos; recovery trawl impacts ID CONTINENTAL-SHELF; GEORGES BANK; DISTURBANCE; COMMUNITIES; HABITAT; IMPACTS; BAY; TRACKS AB The eastern Bering Sea has experienced rapid and intensive development of commercial trawl fisheries. Because of good record keeping and the relatively brief history of fishing it is possible to reconstruct the spatial and temporal patterns of exploitation. Previously unfished (UF) areas can be identified and directly compared with heavily fished (HF) areas to investigate long-term consequences for the benthos. Using this approach, macrofauna populations in a shallow (48 m average) soft-bottom area were studied during 1996. Samples of 92 taxa (reduced for analysis) were collected at 84-1 nm(2) sites straddling a closed-area boundary. Multi- and univariate statistical tests and raw patterns in the data support the Following generalizations: (1) sedentary macrofauna (e.g., anemones, soft corals, sponges, whelk eggs, bryozoans, ascidians), neptunid whelks and empty shells were more abundant in the UF area; (2) mixed responses were observed within motile groups (e.g. crabs, sea stars; whelks) and infaunal bivalves, suggesting the importance of life history characteristics, such as habitat requirements acid feeding mode; and (3) overall diversity and niche breadth of sedentary taxa were greater in the UF area. A systematic approach is required to address the complex issue of bottorn-trawl disturbances. This begins with the identification of chronic and acute impacts, followed by focused investigations of ecological implications and, ultimately, cost-benefit analyses to evaluate specific resource-management options. (C) 2000 International Council for the Exploration of the Sea. C1 US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP McConnaughey, RA (reprint author), US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 61 TC 78 Z9 82 U1 1 U2 23 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD OCT PY 2000 VL 57 IS 5 BP 1377 EP 1388 DI 10.1006/jmsc.2000.0906 PG 12 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 385AJ UT WOS:000165979200011 ER PT J AU Mills, K Scholtz, J Sollins, K AF Mills, K Scholtz, J Sollins, K TI Workshop on smart spaces SO IEEE PERSONAL COMMUNICATIONS LA English DT Editorial Material C1 Natl Inst Stand & Technol, Adv Networking Technol Div, Gaithersburg, MD 20899 USA. George Mason Univ, Fairfax, VA 22030 USA. Def Adv Res Projects Agcy, Informat Technol Off, Arlington, VA USA. MIT, Comp Sci Lab, Adv Networking Architecture Grp, Cambridge, MA 02139 USA. RP Mills, K (reprint author), Natl Inst Stand & Technol, Adv Networking Technol Div, Gaithersburg, MD 20899 USA. RI Scholtz, Jean/E-8955-2013 NR 0 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1070-9916 J9 IEEE PERS COMMUN JI IEEE Pers. Commun. PD OCT PY 2000 VL 7 IS 5 BP 35 EP 35 DI 10.1109/MPC.2000.878534 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 366EU UT WOS:000089992500007 ER PT J AU Holloway, CL Kuester, EE AF Holloway, CL Kuester, EE TI Impedance-type boundary conditions for a periodic interface between a dielectric and a highly conducting medium SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE conducting materials; impedance boundary conditions; nonhomogeneous media; periodic boundary conditions ID SURFACE IMPEDANCE; ELECTROMAGNETIC WAVES; ROUGH SURFACE; REFLECTION; SEA AB Using the homogenization method, we derive a generalized impedance-type equivalent boundary condition for the electromagnetic,(EM) field at a two-dimensional (2-D) periodic highly conducting rough surface with small-scale roughness. The results obtained in this paper generalize ones obtained previously for the case of a perfectly conducting rough surface. We will show that the coefficients in this equivalent boundary condition can be interpreted in terms of electric and magnetic polarizability densities. We also show that when the roughness dimensions are small compared to a skin depth of the conducting region (a smooth interface), the generalized impedance boundary condition given here reduces to the standard Leontovich condition. Results for the reflection coefficient of a plane wave incident onto a 2-D conducting interface are presented. We show the importance of the boundary-layer fields (as used in this study) over that of classical methods when calculating the reflection coefficient from a highly conducting rough interface. This work will lead to an analysis of the effects of surface roughness on power loss in MIMIC circuits. C1 US Dept Commerce, Inst Telecommun Sci, Boulder Labs, Boulder, CO 80303 USA. Univ Colorado, Dept Elect & Comp Engn, Boulder, CO 80309 USA. RP Holloway, CL (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM holloway@its.bldrdoc.gov NR 35 TC 28 Z9 29 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-926X EI 1558-2221 J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD OCT PY 2000 VL 48 IS 10 BP 1660 EP 1672 DI 10.1109/8.899683 PG 13 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QR UT WOS:000166824300019 ER PT J AU Geyer, RG Wait, JR AF Geyer, RG Wait, JR TI Dipole radiation over an inhomogeneous thin sheet SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE dipole antenna; nonhomogeneous materials; thin films AB A general Sommerfeld integral formulation is given for the electromagnetic (EM) fields of an oscillating vertical magnetic or electric dipole over an electrically inhomogeneous thin sheet. The electrical properties of the sheet are characterized by a conductance function that is an arbitrary function of spatial coordinates. When the conductance function has axial symmetry relative to the source dipole, the general solution form simplifies to a Fredholm integral equation of the third kind. The general solution is shown to reduce to the special case of an infinite sheet having uniform conductance. When the sheet conductance is either uniform or varies linearly, the field expressions show an algebraic dependence on the conductance. For a general inhomogeneous conductance distribution, the field dependence is not algebraic. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. RP Geyer, RG (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 11 TC 1 Z9 1 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD OCT PY 2000 VL 48 IS 10 BP 1685 EP 1690 DI 10.1109/8.899685 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QR UT WOS:000166824300021 ER PT J AU Holloway, CL Kuester, EF AF Holloway, CL Kuester, EF TI Power loss associated with conducting and superconducting rough interfaces SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE impedance boundary condition; power loss; rough surfaces; superconducting rough interface ID IMPEDANCE BOUNDARY-CONDITION; METAL-SURFACE AB In recent work, a generalized impedance boundary condition for two-dimensional conducting rough interfaces was derived. In this study, the impedance boundary condition is used to calculate the power loss associated with conducting rough interfaces. Results for two-dimensional conducting and superconducting roughness profiles are shown in this paper, and comparisons to other results in the literature are given. The importance of these roughness effects in microwave and millimeter-wave integrated circuits is also discussed. Suggestions are made to extend this study to three-dimensional random rough interfaces. C1 US Dept Commerce, Boulder Labs, Inst Telecommun Sci, Boulder, CO 80303 USA. Univ Colorado, Dept Elect & Comp Engn, Boulder, CO 80309 USA. RP Holloway, CL (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 35 TC 47 Z9 47 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD OCT PY 2000 VL 48 IS 10 BP 1601 EP 1610 DI 10.1109/22.873886 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 363FL UT WOS:000089824400001 ER PT J AU Phillips, PJ Moon, H Rizvi, SA Rauss, PJ AF Phillips, PJ Moon, H Rizvi, SA Rauss, PJ TI The FERET evaluation methodology for face-recognition algorithms SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE face recognition; algorithm evaluation; FERET database AB Two of the most critical requirements in support of producing reliable face-recognition systems are a large database of facial images and a testing procedure to evaluate systems. The Face Recognition Technology (FERET) program has addressed both issues through the FERET database of facial images and the establishment of the FERET tests. To date, 14,126 images from 1,199 individuals are included in the FERET database, which is divided into development and sequestered portions of the database. In September 1996, the FERET program administered the third in a series of FERET face-recognition tests. The primary objectives of the third test were to 1) assess the slate of the art, 2) identify future areas of research, and 3) measure algorithm performance. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Lau Technol, Littleton, MA 01460 USA. CUNY Coll Staten Isl, Dept Engn Sci & Phys, Staten Isl, NY 10314 USA. USA, Res Lab, Adelphi, MD 20783 USA. RP Natl Inst Stand & Technol, 100 Bur Dr,STOP 8940, Gaithersburg, MD 20899 USA. EM jonathon@nist.gov; hm@lautechnologies.com; rizvi@wagner.csi.cuny.edu; rauss@erim-it.com RI Rauss, Patrick/A-3029-2011 NR 16 TC 2172 Z9 2316 U1 14 U2 108 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD OCT PY 2000 VL 22 IS 10 BP 1090 EP 1104 DI 10.1109/34.879790 PG 15 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 369LQ UT WOS:000165067100003 ER PT J AU Mestas-Nunez, AM AF Mestas-Nunez, AM TI Orthogonality properties of rotated empirical modes SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE orthogonal rotation; principal component analysis; empirical orthogonal function analysis; eigenvector analysis; empirical modes; global models); climate variable(s) ID SURFACE TEMPERATURE VARIABILITY; PRINCIPAL COMPONENT ANALYSIS; CIRCULATION PATTERNS; TROPICAL ATLANTIC; UNITED-STATES; PRECIPITATION; EOF AB The properties (spatial orthogonality and temporal uncorrelatedness) of orthogonally rotated empirical modes depend on the normalization of the modes, prior to rotation. It is shown here that these properties also depend on how the empirical modes are formulated. The preferred convention is one that allows us to reconstruct the data from the unrotated or rotated modes. When the empirical modes are normalized so that the spatial eigenvectors are unit length (i.e. empirical orthogonal functions (EOFs)), the rotated modes preserve spatial orthogonality, but are no longer temporally uncorrelated. Relaxing the temporal orthogonality in this way does not prejudice conclusions that can be inferred regarding the temporal couplings of the rotated modes. Copyright (C) 2000 Royal Meteorological Society. C1 Univ Miami, Cooperat Inst Marine & Atmospher Studies, Miami, FL USA. RP Mestas-Nunez, AM (reprint author), NOAA, AOMI, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Mestas-Nunez, Alberto/A-1427-2012 OI Mestas-Nunez, Alberto/0000-0002-3546-3668 NR 24 TC 31 Z9 32 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD OCT PY 2000 VL 20 IS 12 BP 1509 EP 1516 DI 10.1002/1097-0088(200010)20:12<1509::AID-JOC553>3.0.CO;2-Q PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367MD UT WOS:000090065300008 ER PT J AU O'Neal, CL Crouch, DJ Rollins, DE Fatah, AA AF O'Neal, CL Crouch, DJ Rollins, DE Fatah, AA TI The effects of collection methods on oral fluid codeine concentrations SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article ID SALIVA C1 Univ Utah, Ctr Human Toxicol, Dept Pharmacol & Toxicol, Salt Lake City, UT 84112 USA. Natl Inst Stand & Technol, Off Law Enforcement Stand, Gaithersburg, MD 20899 USA. RP Crouch, DJ (reprint author), Univ Utah, Ctr Human Toxicol, Dept Pharmacol & Toxicol, 20 S 2030 E,Room 490, Salt Lake City, UT 84112 USA. FU NCRR NIH HHS [5M01RR00064]; NIDA NIH HHS [DA07820] NR 12 TC 48 Z9 49 U1 0 U2 4 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD OCT PY 2000 VL 24 IS 7 BP 536 EP 542 PG 7 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 361AT UT WOS:000089700100010 PM 11043656 ER PT J AU Cheng, YT Mildner, DFR Chen-Mayer, HH Sharov, VA Glinka, CJ AF Cheng, YT Mildner, DFR Chen-Mayer, HH Sharov, VA Glinka, CJ TI An imaging-plate detector for small-angle neutron scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SILVER BEHENATE; OF-STANDARDS; OPTIMIZATION; TECHNOLOGY; POWDER AB Small-angle neutron scattering (SANS) measurements have been performed on long-flight-path pinhole-collimation SANS instruments using, as a two-dimensional position-sensitive detector, both a neutron imaging plate, incorporating gadolinium, and a two-step transfer method, with dysprosium foil as the image transfer medium. The measurements are compared with corresponding data taken using conventional position-sensitive gas proportional counters on the SANS instruments in order to assess the viability of the imaging techniques. The imaging plates have pixel sizes of about two orders of magnitude smaller than those of the gas proportional counter. The reduced pixel size provides definite advantages over the gas counter in certain specific situations, namely when limited space necessitates a short sample-to-detector distance, when only small samples (comparable in size to the detector pixels) are available, or when used in conjunction with focusing beam optics. C1 NeuTek, Gaithersburg, MD 20878 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cheng, YT (reprint author), NeuTek, 13537 Scottish Autumn Lane, Gaithersburg, MD 20878 USA. NR 20 TC 4 Z9 4 U1 0 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 2000 VL 33 BP 1253 EP 1261 DI 10.1107/S0021889800009067 PN 5 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 357RX UT WOS:000089515600009 ER PT J AU Cheary, RW Dooryhee, E Lynch, P Armstrong, N Dligatch, S AF Cheary, RW Dooryhee, E Lynch, P Armstrong, N Dligatch, S TI X-ray diffraction line broadening from thermally deposited gold films SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID RESOLUTION POWDER DIFFRACTION; AXIAL DIVERGENCE; VOIGT FUNCTION; GRAIN-SIZE; DIFFRACTOMETER; DISLOCATIONS; STRESS AB Diffraction profiles were analysed from thermally deposited 111-oriented gold films, ranging in thickness from 300 to 1900 Angstrom. The data were collected using the high-resolution powder diffractometer on beamline BM16 at the European Synchrotron Research Facility (ESRF) set at a wavelength of 0.3507 Angstrom. The profiles were measured under conventional symmetric theta-2 theta reflection conditions and by asymmetric transmission diffraction to ensure that only crystallites oriented normal to the substrate contribute to the diffraction. An analysis of the instrument profile shape of the diffractometer was undertaken using the SRM 660 LaB6 line profile standard. A parallel study of the films using atomic force microscopy and transmission electron microscopy was also undertaken to provide information on the dimensions of the crystallite columns in the films and the presence of dislocations. All the films displayed diffraction broadening arising from both crystallite-size effects and dislocation-induced strain effects. Analysis of the magnitude and anisotropy of the dislocation-induced broadening with hkl indicates that the dislocations have a mixed screw/edge character and tend to form primarily on (111) slip planes parallel to the substrate at densities of similar to 10(15) to 10(16) m(-2). C1 Univ Technol Sydney, Dept Appl Phys, Broadway 2007, Australia. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Cheary, RW (reprint author), Univ Technol Sydney, Dept Appl Phys, POB 123, Broadway 2007, Australia. RI dooryhee, eric/D-6815-2013 NR 42 TC 29 Z9 29 U1 1 U2 13 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 2000 VL 33 BP 1271 EP 1283 DI 10.1107/S0021889800009936 PN 5 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 357RX UT WOS:000089515600011 ER PT J AU McMillin, LM Crosby, DS AF McMillin, LM Crosby, DS TI A study of the solar radiation effect on the 4.3-mu m channels of the High-Resolution Infrared Radiation Sounder SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB Measurements of infrared radiation from the National Oceanic and Atmospheric Administration series of satellites are used to retrieve atmospheric temperature, moisture, and ozone. It is well known that the measurements from the 4.3-mum channels of the High-Resolution Infrared Radiation Sounder (HIRS) are affected by solar radiation. These effects can have an important effect on retrieved parameters and have caused difficulties in the use of the higher-peaking shortwave channels for many applications. In the channels that respond to the upper atmosphere, this effect can reach 2 K for high solar angles. In this paper, a regression procedure is used on nighttime data to determine a relationship between these channels and the other channels of the HIRS and the Microwave Sounding Unit of the Television and Infrared Operation Satellite Operational Vertical Sounder. This regression then is applied to daytime data to study the effect of solar radiation on these channels. This paper provides a method for estimating and partially removing these effects. C1 NESDIS, Off Res & Applicat, Climate Res & Applicat Div, Camp Springs, MD 20746 USA. American Univ, Dept Math & Stat, Washington, DC 20016 USA. RP McMillin, LM (reprint author), NESDIS, Off Res & Applicat, Climate Res & Applicat Div, 5200 Auth Rd,Room 810, Camp Springs, MD 20746 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2000 VL 39 IS 10 BP 1791 EP 1796 DI 10.1175/1520-0450(2000)039<1791:ASOTSR>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 373DX UT WOS:000165274100012 ER PT J AU Key, JR Intrieri, JM AF Key, JR Intrieri, JM TI Cloud particle phase determination with the AVHRR SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CIRRUS CLOUDS; IMAGERY AB An accurate determination of cloud particle phase is required for the retrieval of other cloud properties from satellite and for radiative flux calculations in climate models. The physical principles underlying phase determination using the advanced very high resolution radiometer (AVHRR) satellite sensor are described for daytime and nighttime, cold cloud and warm cloud conditions. It is demonstrated that the spectral properties of cloud particles provide necessary, but not sufficient, information for phase determination, because the relationship between the cloud and surface temperatures is also important. Algorithms based on these principles are presented and tested. Validation with lidar and aircraft data from two Arctic held experiments shows the procedures to be accurate in identifying the phase of homogeneous water and ice clouds, though optically thin, mixed-phase, and multilayer clouds are problematic. C1 NOAA, NESDIS, Madison, WI 53706 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Key, JR (reprint author), NOAA, NESDIS, 1225 W Dayton St, Madison, WI 53706 USA. RI Key, Jeffrey/F-5597-2010; Intrieri, Janet/D-5608-2015 OI Key, Jeffrey/0000-0001-6109-3050; NR 18 TC 40 Z9 46 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2000 VL 39 IS 10 BP 1797 EP 1804 DI 10.1175/1520-0450-39.10.1797 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 373DX UT WOS:000165274100013 ER PT J AU Walsh, KM Bennett, B Cooper, MA Holle, RL Kithil, R Lopez, RE AF Walsh, KM Bennett, B Cooper, MA Holle, RL Kithil, R Lopez, RE TI National Athletic Trainers' Association position statement: Lightning safety for athletics and recreation SO JOURNAL OF ATHLETIC TRAINING LA English DT Article DE lightning; policies and procedures; lightning casualties; severe-storm hazards; environmental hazards; emergency action plan; thunderstorms; lightning-safety policy; athletics; recreation ID INJURIES; CASUALTIES; COLORADO; POLICY; DEATHS; STRIKE AB Objective: To educate athletic trainers and others about the dangers of lightning, provide lightning-safety guidelines, define safe structures and locations, and advocate prehospital care for lightning-strike victims. Background: Lightning may be the most frequently encountered severe-storm hazard endangering physically active people each year. Millions of lightning flashes strike the ground annually in the United States, causing nearly 100 deaths and 400 injuries. Three quarters of all lightning casualties occur between May and September, and nearly four fifths occur between 10:00 AM and 7:00 PM, which coincides with the hours for most athletic or recreational activities. Additionally, lightning casualties from sports and recreational activities have risen alarmingly in recent decades. Recommendations: The National Athletic Trainers' Association recommends a proactive approach to lightning safety, including the implementation of a lightning-safety policy that identifies safe locations for shelter from the lightning hazard. Further components of this policy are monitoring local weather forecasts, designating a weather watcher, and establishing a chain of command. Additionally, a flash-to-bang count of 30 seconds or more should be used as a minimal determinant of when to suspend activities. Waiting 30 minutes or longer after the last flash of lightning or sound of thunder is recommended before athletic or recreational activities are resumed. Lightning-safety strategies include avoiding shelter under trees, avoiding open fields and spaces, and suspending the use of land-line telephones during thunderstorms. Also outlined in this document are the prehospital care guidelines for triaging and treating lightning-strike victims. It is important to evaluate victims quickly for apnea, asystole, hypothermia, shock, fractures, and burns. Cardiopulmonary resuscitation is effective in resuscitating pulseless victims of lightning strike. Maintenance of cardiopulmonary resuscitation and first-aid certification should be required of all persons involved in sports and recreational activities. C1 E Carolina Univ, Greenville, NC USA. Coll William & Mary, Williamsburg, VA USA. Univ Illinois, Chicago, IL USA. Natl Severe Storms Lab, Norman, OK 73069 USA. Natl Lightning Safety Inst, Louisville, CO USA. RP Walsh, KM (reprint author), Natl Athlet Trainers Assoc, Dept Commun, 2952 Stemmons Freeway, Dallas, TX 75247 USA. NR 31 TC 18 Z9 19 U1 0 U2 1 PU NATL ATHLETIC TRAINERS ASSOC INC PI DALLAS PA 2952 STEMMONS FREEWAY, DALLAS, TX 75247 USA SN 1062-6050 J9 J ATHL TRAINING JI J. Athl. Train. PD OCT-DEC PY 2000 VL 35 IS 4 BP 471 EP 477 PG 7 WC Sport Sciences SC Sport Sciences GA 393PH UT WOS:000166478500014 PM 16558665 ER PT J AU Lenschow, DH Wulfmeyer, V Senff, C AF Lenschow, DH Wulfmeyer, V Senff, C TI Measuring second- through fourth-order moments in noisy data SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CONVECTIVE BOUNDARY-LAYER; DIFFERENTIAL ABSORPTION LIDAR; WATER-VAPOR; RADAR-RASS; TURBULENCE; PERFORMANCE; STATISTICS; SKEWNESS; PROFILES AB The authors derive expressions for correcting second- through fourth-order moments of measured variables that are contaminated by random uncorrelated noise. These expressions are then tested by applying them to an artificially produced time series as well as measurements from two upward-pointing ground-based lidar systems: a differential absorption lidar that measures water vapor density and a high-resolution Doppler lidar that measures Vertical wind velocity. Both sets of measurements were obtained in a convective boundary layer, and contain sufficient noise to significantly affect measurements of second- and fourth-order moments (as well as integral scale and skewness) throughout the boundary layer. It is shown that the corrections derived here can be used to obtain useful measurements of these moments from instruments such as lidars, which are inherently noisy. The authors also obtain information on higher-order moments of the noise as well as the correlation between noise and atmospheric measurements. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Lenschow, DH (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. RI Senff, Christoph/I-2592-2013; OI LENSCHOW, DONALD/0000-0003-4353-0098 NR 28 TC 83 Z9 83 U1 1 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 2000 VL 17 IS 10 BP 1330 EP 1347 DI 10.1175/1520-0426(2000)017<1330:MSTFOM>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 368GW UT WOS:000090110200004 ER PT J AU Chow, LC Hirayama, S Takagi, S Parry, E AF Chow, LC Hirayama, S Takagi, S Parry, E TI Diametral tensile strength and compressive strength of a calcium phosphate cement: Effect of applied pressure SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article AB The diametral tensile strength (DTS) and compressive strength (CS) of a calcium phosphate cement comprised of tetracalcium phosphate and dicalcium phosphate anhydrous were studied. Cement powder and water were mixed at a powder/liquid ratio of 4.0. The resulting cement pastes were placed in molds and a pressure ranging from 0-2.8 MPa was applied for various lengths of time (0.5-24 h). DTS and CS measurements were conducted on 24-h wet samples. The strength was found to be significantly (p < 0.05) affected by the pressure but not by the time, Samples prepared under a pressure of 0.7 MPa had a mean DTS value of 10.8 +/- 1.0 MPa (n = 5), which is comparable to the values reported in the literature for the same cement prepared under similar conditions. In contrast, the mean CS value obtained in the present study, 66.1 +/- 5.0 MPa (n = 5), was significantly higher than the value (51 +/- 4.5 MPa) previously reported. The higher CS may be attributed to an improved mold design that may reduce sample damage during demolding, and to the use of a loading device that applied a constant pressure to the sample during setting. The average standard deviation of the mean for the 19 DTS sample groups (n = 5 in each group) was 1.1 MPa, corresponding to 9.6% of the mean DTS value. The average standard deviation of the 7 CS sample groups (n = 5 in each group) was 4.5 MPa, corresponding to 7.1% of the mean CS value. (C) 2000 John Wiley & Sons, Inc.*. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Gaithersburg, MD 20899 USA. RP Chow, LC (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Bldg 224,Room A153, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE11789] NR 10 TC 72 Z9 74 U1 1 U2 11 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD OCT PY 2000 VL 53 IS 5 BP 511 EP 517 DI 10.1002/1097-4636(200009)53:5<511::AID-JBM10>3.0.CO;2-E PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 356XK UT WOS:000089469300010 PM 10984699 ER PT J AU Xu, HHK Eichmiller, FC Giuseppetti, AA AF Xu, HHK Eichmiller, FC Giuseppetti, AA TI Reinforcement of a self-setting calcium phosphate cement with different fibers SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE calcium phosphate cement; fiber reinforcement mechanisms; hydroxyapatite; fiber strength; fiber length; volume fraction ID ACRYLIC BONE-CEMENT; CANAL SEALER-FILLER; MECHANICAL-PROPERTIES; HYDROXYAPATITE CEMENT; FAILURE MECHANISMS; COMPOSITES; RESIN; RECONSTRUCTION; BEHAVIOR; IMPLANT AB A water-based calcium phosphate cement (CPC) has been used in a number of medical and dental procedures due to its excellent osteoconductivity and bone replacement capability. However, the low tensile strength of CPC prohibits its use in many unsupported defects and stress-bearing locations. Little investigation has been carried out on the fiber reinforcement of CPC. The aims of the present study, therefore, were to examine whether fibers would strengthen CPC, and to investigate the effects of fiber type, fiber length, and volume fraction. Four different fibers were used: aramid, carbon, E-glass, and polyglactin. Fiber length ranged from 3-200 mm, and fiber volume fraction ranged from 1.9-9.5%. The fibers were mixed with CPC paste and placed into molds of 3 x 4 x 25 mm. A flexural test was used to fracture the set specimens and to measure the ultimate strength, work-of-fracture, and elastic modulus. Scanning electron microscopy was used to examine specimen fracture surfaces. Fiber type had significant effects on composite properties. The composite ultimate strength in MPa (mean +/- SD; n = 6) was (62 +/- 16) for aramid, (59 +/- 11) for carbon, (29 +/- 8) for E-glass, and (24 +/- 4) for polyglactin, with 5.7% volume fraction and 75 mm fiber length. In comparison, the strength of unreinforced CPC was (13 +/- 3). Fiber length also played an important role. For composites containing 5.7% aramid fibers, the ultimate strength was (24 +/- 3) for 3 mm fibers, (36 +/- 13) for 8 mm fibers, (48 +/- 14) for 25 mm fibers, and (62 +/- 16) for 75 mm fibers. At 25 mm fiber length, the ultimate strength of CPC composite was found to be linearly proportional to fiber strength. In conclusion, a self-setting calcium phosphate cement was substantially strengthened via fiber reinforcement. Fiber length, fiber volume fraction, and fiber strength were found to be key microstructural parameters that controlled the mechanical properties of CPC composites. (C) 2000 John Wiley & Sons, Inc. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, 100 Bur Dr,Stop 8546, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [P50 DE09322, R29 DE12476] NR 45 TC 91 Z9 101 U1 4 U2 40 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD OCT PY 2000 VL 52 IS 1 BP 107 EP 114 DI 10.1002/1097-4636(200010)52:1<107::AID-JBM13>3.3.CO;2-S PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 337NV UT WOS:000088369000013 PM 10906680 ER PT J AU Patrickios, CS Lue, L AF Patrickios, CS Lue, L TI Equation of state for star polymers in good solvents SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATION; INTEGRAL-EQUATION; INTRAMOLECULAR STRUCTURES; CHEMICAL-EQUILIBRIA; CHAIN MOLECULES; CLUSTER THEORY; FLUIDS; DILUTE; THERMODYNAMICS; PRESSURE AB We develop a free-energy model for star polymers in good solvents that accurately describes concentrated polymer solutions and displays the correct universal scaling behavior, in the limit of infinite molecular weight, for dilute and semidilute polymer concentrations. The architecture of the polymer molecules enters the model through the value of the second virial coefficient and the rescaled penetration function <(Psi)over bar>, the ratio of the penetration function Psi(f) to its asymptotic, infinite-molecular-weight value Psi*(f), where f is the number of arms on the star polymer. The direction of approach of the equation of state to the universal, infinite-molecular-weight scaling limit depends on the relative magnitude of <(Psi)over bar>. For <(Psi)over bar>>1, the scaling equation of state is approached from "above," while for <(Psi)over bar><1, the scaling equation of state is approached from "below." We also perform new Monte Carlo simulations for the pressure and mean-square radius of gyration of star polymers composed of tangent-hard-spheres. The theory compares well with the Monte Carlo simulation data for the equation of state. (C) 2000 American Institute of Physics. [S0021-9606(00)50637-0]. C1 Univ Cyprus, Dept Chem, CY-1678 Nicosia, Cyprus. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Univ Manchester, Dept Chem Engn, POB 88, Manchester M60 1QD, Lancs, England. RI Lue, Leo/E-7846-2011; OI Lue, Leo/0000-0002-4826-5337; Patrickios , Costas S. /0000-0001-8855-0370 NR 47 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 2000 VL 113 IS 13 BP 5485 EP 5492 AR PII [S0021-9606(00)50637-0] DI 10.1063/1.1289883 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 354TC UT WOS:000089344900045 ER PT J AU Tewari, YB Goldberg, RN Rozzell, JD AF Tewari, YB Goldberg, RN Rozzell, JD TI Thermodynamics of reactions catalysed by branched-chain-amino-acid transaminase SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE apparent equilibrium constant; branched-chain-amino-acid transaminase; 3,3-dimethyl-2-oxobutanoate; enthalpy; entropy; Gibbs free energy; L-glutamate; L-leucine; 2-oxoglutarate; 2-oxoisocaproate; 2-oxoisovalerate; L-tert-leucine; L-valine ID EQUILIBRIUM AB Apparent equilibrium constants and calorimetric enthalpies of reaction have been measured for reaction a catalysed by branched-chain-amino-acid transaminase. The following biochemical reactions have been studied at the temperature 298.15 K and in the pH range (7.15 to 7.24): L-valine(aq) + 2-oxoglutarate(aq) = 2-oxoisovalerate(aq) + L-glutamate(aq); L-leucine(aq) + 2-oxoglutarate(aq) = 2-oxoisocaproate(aq) + L-glutamate(aq); and L-tert-leucine(aq) + 2-oxoglutarate(aq) = 3,3-dimethyl-2-oxobutanoate(aq) + L-glutamate(aq). The results have been used to calculate equilibrium constants and standard molar enthalpy Delta H-r(m)o, entropy Delta S-r(m)o, and Gibbs free energy Delta (r)G(m)(o) changes for reference reactions involving specific species. Apparent equilibrium constants and standard transformed Gibbs free energy changes for these reactions under physiological conditions have also been calculated. The use of these results fur optimization of product yields of the branched-chain amino acids is discussed. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. BioCatalyt Inc, Pasadena, CA 91105 USA. RP Goldberg, RN (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Mailstop 8312, Gaithersburg, MD 20899 USA. NR 29 TC 11 Z9 11 U1 3 U2 7 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD OCT PY 2000 VL 32 IS 10 BP 1381 EP 1398 PG 18 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 381VH UT WOS:000165783800007 ER PT J AU Soden, BJ Schroeder, SR AF Soden, BJ Schroeder, SR TI Decadal variations in tropical water vapor: A comparison of observations and a model simulation SO JOURNAL OF CLIMATE LA English DT Letter ID DATASET AB Multiple satellite records of tropical-mean water vapor are compared with a general circulation model (GCM) simulation to assess the ability to monitor and to predict low-frequency changes in total precipitable water. Particular attention is focused on the drying between 1979 and 1995 recorded by a TOVS statistical retrieval that is calibrated to radiosondes. Both a GCM integrated with observed SSTs and microwave and TOVS physical retrievals that overlap the drying period show no sustained drying. This discrepancy is consistent with the suggestion by Ross and Gaffen that the TOVS statistical algorithm is vulnerable to radiosonde instrumentation changes over this period that introduce an artificial drying trend into the retrieval. C1 Natl Ocean & Atmospher Adm, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. RP Soden, BJ (reprint author), Natl Ocean & Atmospher Adm, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 16 TC 10 Z9 10 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT 1 PY 2000 VL 13 IS 19 BP 3337 EP 3341 DI 10.1175/1520-0442(2000)013<3337:DVITWV>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367RJ UT WOS:000090075000001 ER PT J AU Curran, EB Holle, RL Lopez, RE AF Curran, EB Holle, RL Lopez, RE TI Lightning casualties and damages in the United States from 1959 to 1994 SO JOURNAL OF CLIMATE LA English DT Article ID DEATHS; SAFETY; POLICY AB Lightning-caused fatalities, injuries, and damage reports for the United States are listed in the National Oceanic and Atmospheric Administration publication Storm Data. Previously published studies of lightning casualties and damages in the United States covered only portions of the period since Storm Data began publication in 1959, did not weight by population, or did not present complete information with respect to time of year and day. Therefore, an analysis was made of all 3239 deaths, 9818 injuries, and 19 814 property damage reports in Storm Data due to lightning from 1959 to 1994. This paper depicts lightning casualties (deaths and injuries combined) and damage reports stratified by state and region of the United States, decade, population, time of year and day, and all other information in Storm Data. Florida had the most deaths (345) and injuries (1178) from lightning, and Pennsylvania had the most damage reports (1441). A rate of one fatality per 86 000 cloud-to-ground flashes is estimated from recent lightning detection network information. After population was taken into account, Wyoming and New Mexico had the highest death, injury, and casualty rates. The U.S. rate is 0.42 lightning deaths per million people per year from 1959 to 1994. Highest population-weighted damage rates were on the plains, but the pattern was variable from decade to decade. July had more lightning entries of all types than any other month; damage reports were spread more evenly through the year. Casualties and damages in the northern half of the United States had narrower distributions centered on summer than did the southern half. Two-thirds of the casualties were between noon and 6 P.M.; damage reports were relatively frequent at night in the plains and Midwest. Most lightning incidents involved one person, and males were five times as likely as females to be killed or injured. Storm Data excludes most small losses but includes more expensive and widely known lightning-related losses. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Natl Weather Serv, Forecast Off, Ft Worth, TX USA. RP Holle, RL (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 34 TC 94 Z9 102 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT 1 PY 2000 VL 13 IS 19 BP 3448 EP 3464 DI 10.1175/1520-0442(2000)013<3448:LCADIT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367RJ UT WOS:000090075000007 ER PT J AU Adams, JM Bond, NA Overland, JE AF Adams, JM Bond, NA Overland, JE TI Regional variability of the Arctic heat budget in fall and winter SO JOURNAL OF CLIMATE LA English DT Article ID MEAN MERIDIONAL TRANSPORT; ENERGY FLUX; ATMOSPHERE; RADIATION; OCEAN; REANALYSES; DATASET; SYSTEM; FIELDS; ICE AB In the Arctic atmosphere, the fall cooling cycle involves the evolution of the zonally symmetric circulation in late summer into the asymmetric flow of winter. This paper uses historical reanalysis data to document how the dominant components of the Arctic heat budget influence the summer-winter transition. The spatial variability of 20-yr climatologies of 700-mb temperature and geopotential height, the net surface flux, and the horizontal convergence of eddy sensible heat fluxes are examined for September through February. The development of the zonal asymmetries in the temperature and geopotential height fields in the Arctic is linked to the land-water-ice distribution that regulates the surface fluxes and the baroclinic zones in the hemispheric circulation, which lead to regional heating/cooling by the transient and standing eddies. These eddies serve to transport the heat energy gained via the surface fluxes over the North Atlantic and North Pacific to the continental and ice-covered regions of the central Arctic, where the net surface flux is small. The transient eddies are especially important in the Atlantic and Eurasian sectors of the Arctic, while the standing eddies play the larger role in the heat budget on the Pacific side of the Arctic in early to mid-winter The Arctic oscillation (AO) has a small effect on the basinwide pattern of heating and cooling by the eddy circulations, but on smaller spatial scales there are isolated regions where the AO influences the Arctic heat budget. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Adams, JM (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. NR 35 TC 10 Z9 12 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT 1 PY 2000 VL 13 IS 19 BP 3500 EP 3510 DI 10.1175/1520-0442(2000)013<3500:RVOTAH>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367RJ UT WOS:000090075000010 ER PT J AU Shirley, EL AF Shirley, EL TI Theory and simulation of resonant inelastic X-ray scattering in s-p bonded systems: graphite, hexagonal boron nitride, diamond, and cubic boron nitride SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE inelastic X-ray scattering; graphite; hexagonal boron nitride; diamond; cubic boron nitride ID AB-INITIO CALCULATION; BAND-STRUCTURE; OPTICAL-ABSORPTION; INSULATORS; SEMICONDUCTORS; ENERGIES; GAPS AB This work discusses the theory of resonant inelastic X-ray scattering (RMS) in the s-p bonded solids, graphite, hexagonal boron nitride (hBN), diamond, and cubic boron nitride (cBN). In RIXS, core electrons are resonantly excited to unoccupied states, and X-ray emission (because of radiative core hole-valence electron recombination) is studied. In particular, evolution of the emission spectrum with increasing incident photon energy is of interest. This work begins with the independent-electron approach originally set forth by Ma and co-workers, which is based on the Kramers-Heisenberg formula for light scattering. However, simulations presented also examine effects of the inclusion of the attraction between the promoted electron and core hole in intermediate states. The results suggest that, while RIXS emission spectra can be influenced by that attraction, many features of the independent-electron picture are essentially preserved. The interplay between electron interactions, band-structure effects, and the effects being omitted is discussed. (C) 2000 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Shirley, EL (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. EM eric.shirley@nist.gov NR 32 TC 29 Z9 29 U1 0 U2 14 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 OCT PY 2000 VL 110 IS 1-3 SI SI BP 305 EP 321 DI 10.1016/S0368-2048(00)00170-5 PG 17 WC Spectroscopy SC Spectroscopy GA 362JH UT WOS:000089774500018 ER PT J AU Moon, KW Boettinger, WJ Kattner, UR Biancaniello, FS Handwerker, CA AF Moon, KW Boettinger, WJ Kattner, UR Biancaniello, FS Handwerker, CA TI Experimental and thermodynamic assessment of Sn-Ag-Cu solder alloys SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TENNESSEE SP Miner, Met & Mat Soc, Extract & Process Div DE Pb-free solder; Sn-Ag-Cu solder; phase diagram; ternary eutectic; and thermal analysis ID PHASE-DIAGRAM; SYSTEM; OPTIMIZATION AB Sn-rich alloys in the Sn-Ag-Gu system are being studied for their potential as Pb-free solders. Thus, the location of the ternary eutectic involving L, (Sn), Ag3Sn and Cu6Sn, phases is of critical interest. Phase diagram data in the Sn-rich corner of the Sn-Ag-Cu system are measured. The ternary eutectic is confirmed to be at a composition of 3.5 wt.% Ag, 0.9 wt.% Cu at a temperature of 217.2 +/- 0.2 degrees C (2 sigma). A thermodynamic calculation of the Sn-rich part of the diagram from the three constituent binary systems and the available ternary data using the CALPHAD method is conducted. The best fit to the experimental data is 3.66 wt.% Ag and 0.91 wt.% Cu at a temperature of 216.3 degrees C. Using the thermodynamic description to obtain the enthalpy-temperature relation, the DTA signal is simulated and used to explain the difficulty of liquidus measurements in these alloys. C1 NIST, Div Met, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Moon, KW (reprint author), NIST, Div Met, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 24 TC 373 Z9 386 U1 5 U2 79 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD OCT PY 2000 VL 29 IS 10 BP 1122 EP 1136 DI 10.1007/s11664-000-0003-x PG 15 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 364LU UT WOS:000089894500003 ER PT J AU Grafton, RQ Squires, D Fox, KJ AF Grafton, RQ Squires, D Fox, KJ TI Private property and economic efficiency: A study of a common-pool resource SO JOURNAL OF LAW & ECONOMICS LA English DT Article ID FRONTIER PRODUCTION FUNCTION; SULFUR-DIOXIDE EMISSIONS; ALLOCATIVE INEFFICIENCY; COST FUNCTION; RIGHTS; MARKET; QUOTA; FISHERIES; PROGRAMS; MODEL AB The British Columbia halibut fishery provides a natural experiment of the effects of "privatizing the commons." Using firm-level data from the fishery 2 years before private harvesting rights were introduced, the year they were implemented, and 3 years afterward, a stochastic frontier is estimated to test for changes in technical, allocative, and economic efficiency. The study indicates that (1) the short-run efficiency gains from privatization may take several years to materialize and can be compromised by restrictions on transferability, duration, and divisibility of the property right; (2) substantial long-run gains in efficiency can be jeopardized by preexisting regulations and the bundling of the property right to the capital stock; and (3) the gains from privatization are not just in terms of cost efficiency but include important benefits in revenue and product form. C1 Univ Ottawa, Inst Environm, Ottawa, ON K1N 6N5, Canada. US Natl Marine Fisheries Serv, Charleston, SC USA. Univ New S Wales, Kensington, NSW 2033, Australia. RP Grafton, RQ (reprint author), Univ Ottawa, Inst Environm, Ottawa, ON K1N 6N5, Canada. RI Grafton, R. Quentin/A-5277-2008 OI Grafton, R. Quentin/0000-0002-0048-9083 NR 64 TC 119 Z9 121 U1 3 U2 25 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0022-2186 J9 J LAW ECON JI J. Law Econ. PD OCT PY 2000 VL 43 IS 2 BP 679 EP 713 PG 35 WC Economics; Law SC Business & Economics; Government & Law GA 370QW UT WOS:000165134600013 ER PT J AU Myatt, CJ King, BE Turchette, QA Sackett, CA Kielpinski, D Itano, WM Monroe, C Wineland, DJ AF Myatt, CJ King, BE Turchette, QA Sackett, CA Kielpinski, D Itano, WM Monroe, C Wineland, DJ TI Decoherence of motional states of trapped ions SO JOURNAL OF MODERN OPTICS LA English DT Article ID QUANTUM; ATOM AB We have studied the decoherence of motional-state superpositions of single trapped ions caused by their coupling to fluctuating fields. We illustrate these studies by showing how Schroedinger-cat state superpositions decohere in the presence of purposely-applied uniform stochastic electric fields and we compare these results to the decoherence caused by ambient fields in the experiments. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Myatt, CJ (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RI Monroe, Christopher/G-8105-2011; OI Kielpinski, David/0000-0002-2816-6892 NR 23 TC 6 Z9 6 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD OCT PY 2000 VL 47 IS 12 BP 2181 EP 2186 DI 10.1080/09500340008235140 PG 6 WC Optics SC Optics GA 355TJ UT WOS:000089402200013 ER PT J AU Flaud, JM Arcas, P Lafferty, WJ Burger, H Pawelke, G AF Flaud, JM Arcas, P Lafferty, WJ Burger, H Pawelke, G TI First high-resolution infrared observation of the symmetry-forbidden nu(5) band of (B2H6)-B-10 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID DIBORANE AB Spectra of B-10 monoisotopic diborane, B2H6, have been recorded at high resolution (2-3 X 10(-3) cm(-1)) by means of Fourier transform spectroscopy in the region 700-1300 cm(-1). A thorough analysis of the nu(18) a-type, nu(14) c-type, and nu(5) symmetry-forbidden band has been performed. Of particular interest are the results concerning the nu(5) symmetry-forbidden band, which is observed only because it borrows intensity through an a-type Coriolis interaction with the very strong nu(18) infrared band located approximately 350 cm(-1) higher in wavenumber. The nu(5) band has been observed around 833 cm(-1) and consists of a well-resolved Q branch accompanied by weaker P- and R-branch lines. Very anomalous Line intensities are seen, with the low K-a transitions being vanishingly weak, and Raman-like selection rules observed. The determination of the upper state Hamiltonian constants proved to be difficult since the corresponding energy levels of each of the bands are strongly perturbed by nearby dark states. To account for these strong localized resonances, it was necessary to introduce the relevant interacting terms in the Hamiltonian. As a result the upper state energy levels were calculated satisfactorily, and precise vibrational energies and rotational and coupling constants were determined. In particular the following band centers were derived: nu(0) (nu(5)) = 832.8496(70) cm(-1), nu(0) (nu(14)) = 977.57843(70) cm(-1), and nu(0) (nu(18)) = 1178.6346(40) cm(-1). (Type A standard uncertainties (1 sigma) are given in parentheses.) (C) 2000 Academic Press. C1 Univ Paris 11, CNRS, Photophys Mol Lab, F-91405 Orsay, France. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ GH, FB 9, D-42097 Wuppertal, Germany. RP Flaud, JM (reprint author), Univ Paris 11, CNRS, Photophys Mol Lab, Batiment 210, F-91405 Orsay, France. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 2000 VL 203 IS 2 BP 249 EP 254 DI 10.1006/jmsp.2000.8180 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 359GY UT WOS:000089604200006 ER PT J AU Flaud, JM Lafferty, WJ Burger, H Pawelke, G Domenech, JL Bermejo, D AF Flaud, JM Lafferty, WJ Burger, H Pawelke, G Domenech, JL Bermejo, D TI First observation of the nu(17)-nu(4) difference bands of diborane (B2H6)-B-10 and (B2H6)-B-11 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID RESOLUTION AB An analysis of the nu(17)-nu(4) difference bands near 800 cm(-1) of two isotopic species, (B2H6)-B-10 and (B2H6)-B-11, of diborane has been carried out using infrared spectra recorded with a resolution of ca. 0.003 cm(-1). In addition, the nu(17) band of (B2H6)-B-10 has been recorded and assigned. Since this band in (B2H6)-B-11 had already been studied (R. L. Sans, T. A. Blake, S. W. Sharpe, J.-M. Flaud, and W. J. Lafferty, J. Mol. Spectrosc. 191, 331-342 (1998)), it was possible to derive precise energy levels and Hamiltonian constants for the 4(1) vibrational states of both isotopic species. (C) 2000 Academic Press. C1 Univ Paris 11, CNRS, Photophys Mol Lab, F-91405 Orsay, France. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Berg Univ Gesamthsch Wuppertal, FB 9, D-42097 Wuppertal, Germany. CSIC, Inst Estructura Mat, E-28006 Madrid, Spain. RP Flaud, JM (reprint author), Univ Paris 11, CNRS, Photophys Mol Lab, Batiment 210, F-91405 Orsay, France. RI Domenech, Jose/F-5561-2013 OI Domenech, Jose/0000-0001-8629-2566 NR 8 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 2000 VL 203 IS 2 BP 339 EP 344 DI 10.1006/jmsp.2000.8196 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 359GY UT WOS:000089604200016 ER PT J AU Walters, GE Wilderbuer, TK AF Walters, GE Wilderbuer, TK TI Decreasing length at age in a rapidly expanding population of northern rock sole in the eastern Bering Sea and its effect on management advice SO JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 4th International Symposium on Flatfish Ecology CY OCT 18-23, 1999 CL ATLANTIC BEACH, NORTH CAROLINA SP Netherlands Inst Sea Res, Marine Fisheries, N Carolina Div, N Carolina Sea Grant, N Carolina State Univ DE length-at-age; rock sole; density-dependence; Bering Sea; distribution shift; stock-assessment ID DENSITY-DEPENDENT GROWTH; COD GADUS-MORHUA; SILVER HAKE; PACIFIC; TEMPERATURE; ATLANTIC; RECRUITMENT; VARIABILITY; IMPACTS; HADDOCK AB The highly productive eastern Bering Sea shelf has undergone a dramatic increase in the size of flatfish stocks during the last 20 years. This has been highlighted by the northern rock sole stock. which has increased well over 15 times from approximately 175 x 10(6) kg in 1975 to nearly 3 x 10(9) kg in 1994. Annual bottom trawl surveys and an age-structured population model have been used to track the increase. A new evaluation of the data has shown significant decreases in length-at-age (and resultant weight-at-age) as the population increased and expanded westward toward the shelf edge. The downward trend in length-at-age primarily affected year classes between 1979 and 1987. A small increase has occurred subsequently. Potential density-dependent relationships are examined with the significant regression of mean length at age-3 versus population changes. These differences in growth were incorporated into a stock assessment model to examine their effect on estimates of recruitment variability, fluctuations in stock biomass and yield recommendations. Published by Elsevier Science B.V. C1 Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Walters, GE (reprint author), Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 25 TC 12 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1385-1101 J9 J SEA RES JI J. Sea Res. PD OCT PY 2000 VL 44 IS 1-2 BP 17 EP 26 DI 10.1016/S1385-1101(00)00045-9 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 395TZ UT WOS:000166598500003 ER PT J AU Burke, JS Monaghan, JP Yokoyama, S AF Burke, JS Monaghan, JP Yokoyama, S TI Efforts to understand stock structure of summer flounder (Paralichthys dentatus) in North Carolina, USA SO JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 4th International Symposium on Flatfish Ecology CY OCT 18-23, 1999 CL ATLANTIC BEACH, NORTH CAROLINA SP Netherlands Inst Sea Res, Marine Fisheries, N Carolina Div, N Carolina Sea Grant, N Carolina State Univ DE mark recapture; larval immigration; salinity tolerance; zoogeographic barrier ID EARLY-LIFE-HISTORY; OLIVACEUS; POPULATIONS; TEMPERATURE; PATTERNS; GROWTH AB Understanding the stock structure of the summer flounder is critical to attempts to manage this species. Currently such research is particularly urgent due to increased interest in commercial culture and stock enhancement of summer flounder as this creates pressure to transplant fish among geographic areas. Studies of summer flounder in the coastal waters of North Carolina are of particular relevance to the stock structure due to the existence of a zoogeographic boundary at Cape Hatteras, NC. The importance of this boundary is being investigated through mark-recapture studies of adults, field sampling of larvae and laboratory experiments on larvae and juveniles originating from different brood stocks. Twenty-three thousand summer flounder were marked in coastal waters and movement of recaptured animals relative to season and the zoogeographic boundary analysed. Seasonal occurrence of larvae relative to this boundary was compared and animals were characterised in terms of fin ray numbers and size and developmental stage at arrival at the coast. In the laboratory we reared larvae from two brood stocks; one originating from the northern portion of the summer flounders range, and the other from North Carolina. These animals were used to determine the importance of temperature to fin ray formation and to compare growth of the two groups of larvae relative to temperature. Additional laboratory experiments include comparisons of salinity tolerance of larvae during the settlement period. Our results support the existence of different groups relative to this zoogeographic barrier and suggest that extensive movement of summer flounder from one region to another for stock enhancement or culture should be prohibited. Published by Elsevier Science B.V. C1 NOAA, NOS, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. N Carolina Div Marine Fisheries, Morehead City, NC 28557 USA. Hokkaido Inst Mariculture, Shikabe, Hokkaido 04114, Japan. RP Burke, JS (reprint author), NOAA, NOS, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 32 TC 19 Z9 21 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1385-1101 J9 J SEA RES JI J. Sea Res. PD OCT PY 2000 VL 44 IS 1-2 BP 111 EP 122 DI 10.1016/S1385-1101(00)00047-2 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 395TZ UT WOS:000166598500011 ER PT J AU Eisler, TJ AF Eisler, TJ TI Backscattering cross section of a rigid biconic reflector SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Plane wave incidence on a rigid biconic target is considered. A biconic reflector consists of two cones truncated by planes perpendicular to their axes and joined at their smaller flat faces. The cone angles are allowed to be variable, provided their sum is equal to 90 degrees. The backscattering cross section is expressed in terms of a surface integral of the geometrical acoustics field, which results from incident singly and doubly reflected rays. A saddle-point calculation gives a first-order high-frequency approximation in which the backscattering cross section is proportional to the incident wave number and a function of the angle of incidence, cone angles, and inner and outer radii of the truncated cones. This expression is algebraically complex but easy to implement numerically. Results are presented that exercise the parameters of the problem. An interesting result of the solution is that for fixed outer radii there is a nonzero optimum inner radius for backscattering strength. For broadside incidence on 45 degrees cones with equal outer radii, this optimum value is approximately equal to 11% of the outer radius. [S0001-4966(00)04910-9]. C1 NOAA, Coast Survey Dev Lab, NCS11, Silver Spring, MD 20910 USA. RP Eisler, TJ (reprint author), NOAA, Coast Survey Dev Lab, NCS11, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD OCT PY 2000 VL 108 IS 4 BP 1474 EP 1479 DI 10.1121/1.1310193 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 364LW UT WOS:000089894700010 PM 11051473 ER PT J AU Paik, U Hackley, VA AF Paik, U Hackley, VA TI Influence of solids concentration on the isoelectric point of aqueous barium titanate SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID POLYACRYLIC-ACID; AMMONIUM SALT; BATIO3; SUSPENSIONS; PARTICLES AB We report on findings that the particle surface charge is influenced by solids concentration in aqueous suspensions of BaTiO3. Three decades in solids concentration were analyzed by combining results from two different electrokinetic methods. Combined results demonstrate a systematic acidic shift in the isoelectric pH with decreasing solids concentration. The shift is attributed to the development of a Ba-depleted, TiO2-rich surface layer. Using kinetic arguments, it is shown that the thickness of this layer will be proportional to the surface-to-volume ratio. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. Hanyang Univ, Dept Ceram Engn, Seoul 133791, South Korea. RP Hackley, VA (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 17 TC 52 Z9 52 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2000 VL 83 IS 10 BP 2381 EP 2384 PG 4 WC Materials Science, Ceramics SC Materials Science GA 363KG UT WOS:000089834400006 ER PT J AU Eluszkiewicz, J Hemler, RS Mahlman, JD Bruhwiler, L Takacs, LL AF Eluszkiewicz, J Hemler, RS Mahlman, JD Bruhwiler, L Takacs, LL TI Sensitivity of age-of-air calculations to the choice of advection scheme SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; SEMI-LAGRANGIAN TRANSPORT; SHAPE-PRESERVING INTERPOLATION; TRACE CONSTITUENT TRANSPORT; ISENTROPIC-SIGMA-MODEL; CARBON-DIOXIDE; STRATOSPHERIC TRANSPORT; RESIDUAL CIRCULATION; TROPOSPHERE EXCHANGE; NUMERICAL ADVECTION AB The age of air has recently emerged as a diagnostic of atmospheric transport unaffected by chemical parameterizations, and the features in the age distributions computed in models have been interpreted in terms of the models' large-scale circulation field. This study shows, however, that in addition to the simulated large-scale circulation, three-dimensional age calculations can also be affected by the choice of advection scheme employed in solving the tracer continuity equation. Specifically, using the 3.0 degrees latitude x 3.6 degrees longitude and 40 vertical level version of the Geophysical Fluid Dynamics Laboratory SKYHI GCM and six online transport schemes ranging from Eulerian through semi-Lagrangian to fully Lagrangian, it will be demonstrated that the oldest ages are obtained using the nondiffusive centered-difference schemes while the youngest ages are computed with a semi-Lagrangian transport (SLT) scheme. The centered-difference schemes are capable of producing ages older than 10 years in the mesosphere, thus eliminating the "young bias" found in previous age-of-air calculations. At this stage, only limited intuitive explanations can be advanced for this sensitivity of age-of-air calculations to the choice of advection scheme. In particular, age distributions computed online with the National Center for Atmospheric Research Community Climate Model (MACCM3) using different Varieties of the SLT scheme are substantially older than the SKYHI SLT distribution. The different varieties, including a noninterpolating-in-the-vertical version (which is essentially centered-difference in the vertical), also produce a narrower range of age distributions than the suite of advection schemes employed in the SKYHI model. While additional MACCM3 experiments with a wider range of schemes would be necessary to provide more definitive insights, the older and less variable MACCM3 age distributions can plausibly be interpreted as being due to the semi-implicit semi-Lagrangian dynamics employed in the MACCM3. This type of dynamical core (employed with a 60-min time step) is likely to reduce SLT's interpolation errors that are compounded by the short-term variability characteristic of the explicit centered-difference dynamics employed in the SKYHI model (time step of 3 min). In the extreme case of a very slowly varying circulation, the choice of advection scheme has no effect on two-dimensional (latitude-height) age-of-air calculations, owing to the smooth nature of the transport circulation in 2D models. These results suggest that nondiffusive schemes may be the preferred choice for multiyear simulations of tracers not overly sensitive to the requirement of monotonicity (this category includes many greenhouse gases). At the same rime, age-of-air calculations offer a simple quantitative diagnostic of a scheme's long-term diffusive properties and may help in the evaluation of dynamical cores in multiyear integrations. On the other hand, the sensitivity of the computed ages to the model numerics calls for caution in using age of air as a diagnostic of a GCM's large-scale circulation field. C1 Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Eluszkiewicz, J (reprint author), Atmospher & Environm Res Inc, 840 Mem Dr, Cambridge, MA 02139 USA. NR 63 TC 33 Z9 33 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD OCT 1 PY 2000 VL 57 IS 19 BP 3185 EP 3201 DI 10.1175/1520-0469(2000)057<3185:SOAOAC>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 362MW UT WOS:000089782600001 ER PT J AU Pace, RM AF Pace, RM TI Winter survival rates of American woodcock in south central Louisiana SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE American woodcock; hunting; Louisiana; mortality; predation; Scolopax minor; survival; telemetry AB Declines in abundance of American woodcock (Scolopax minor; hereafter woodcock) have led to more restrictive hunting regulations imposed by the U.S. Fish and Wildlife Service, although there is little evidence to suggest that declines were related to hunting. To estimate winter survival and document hunting mortality rates, I radiotagged 160 female woodcock on a public hunting area in south central Louisiana. Woodcock were captured in fields at night from late November through December during 1994-96 and monitored at least daily. At least 37 woodcock died, primarily from avian predators. Day of capture and condition at date of capture were not predictive of survival. Survival rates were similar across ages and years except for lower survival of juvenile birds during 1993-94. The overall survival rate for the period 1 December to 15 February (77 days) was 72 +/- 5%, which was the same or higher than reported elsewhere in winter. Hunting mortality varied from 1.6 to 12.2%, which seemed relatively low given the ample public hunting opportunity and a high winter-long fidelity to the study area. C1 Louisiana State Univ, Louisiana Cooperat Fis & Wildlife Res Unit, Biol Resource Div, US Geol Survey, Baton Rouge, LA 70803 USA. RP Pace, RM (reprint author), NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 26 TC 10 Z9 10 U1 1 U2 3 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 USA SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 2000 VL 64 IS 4 BP 933 EP 939 DI 10.2307/3803201 PG 7 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA 369EL UT WOS:000165053000005 ER PT J AU Dahlgren, TG Weinberg, JR Halanych, KM AF Dahlgren, TG Weinberg, JR Halanych, KM TI Phylogeography of the ocean quahog (Arctica islandica): influences of paleoclimate on genetic diversity and species range SO MARINE BIOLOGY LA English DT Article ID HUMAN MITOCHONDRIAL-DNA; MIDDLE ATLANTIC BIGHT; POPULATION-STRUCTURE; NORTHWEST ATLANTIC; CONTINENTAL-SHELF; COALESCENT THEORY; MARINE MOLLUSKS; BOREAL MOLLUSKS; GROWTH-RATES; PHYLOGENY AB The ocean quahog, Arctica islandica (Linnaeus, 1767), is a commercially important bivalve found on continental shelves throughout much of the North Atlantic. To assess genetic subdivision in this species. we sequenced 385 nucleotides of the mitochondrial cytochrome b (cyt b) gene from 83 specimens collected from 12 localities between September 1998 and July 1999 (based on preliminary data, the Internal Transcribed Spacers, ITS, of the nuclear ribosomal repeat were not useful). The cyt b data delimited 11 haplotypes with 0.26 to 8.1% nucleotide difference (coded by 36 variable nucleotide positions) among them. Only three haplotypes were detected in 39 specimens collected along the USA coastline, compared to five haplotypes from nine Icelandic individuals. The western Atlantic populations ranging from Penobscot Bay (Maine, USA) to southern Virginia showed relatively low diversity and appeared genetically similar in that region. Based on the presence of shared haplotypes, AMOVA analyses, and phylogenetic reconstructions, Icelandic populations appear to be more genetically similar to western Atlantic populations than eastern Atlantic populations. Specimens from the Faroe Islands (II = 4) show mixed affinities. These data are consistent with the hypothesis that a warm Holocene climatic optimum (ca. 7,500 years BP), and not glacial refugia, shaped the present-day genetic structure in A. islandica. C1 Woods Hole Oceanog Inst, Biol Dept MS 33, Woods Hole, MA 02543 USA. Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. RP Halanych, KM (reprint author), Woods Hole Oceanog Inst, Biol Dept MS 33, Woods Hole, MA 02543 USA. RI Halanych, Ken/A-9480-2009; Dahlgren, Thomas/B-1636-2010 OI Halanych, Ken/0000-0002-8658-9674; NR 80 TC 85 Z9 89 U1 1 U2 17 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD OCT PY 2000 VL 137 IS 3 BP 487 EP 495 DI 10.1007/s002270000342 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 371PH UT WOS:000165187000012 ER PT J AU Forcada, J Aguilar, A AF Forcada, J Aguilar, A TI Use of photographic identification in capture-recapture studies of Mediterranean monk seals. SO MARINE MAMMAL SCIENCE LA English DT Article DE abundance estimate; Cap Blanc; capture-recapture; field techniques; Mediterranean monk seals; Monachus monachus; photo-identification; western Sahara ID MONACHUS-SCHAUINSLANDI; WESTERN SAHARA; SIZE; SURVIVAL; TIME AB The use of photo-identification and its reliability in capture-recapture studies of Mediterranean monk seals were assessed using slides collected in the colony at Cap Blanc, western Sahara, from 1993 to 1996. Five tests indicated that researchers involved in photo-identification were proficient in matching slides of identified seals, consistent in classifying the side of the seal shown in slides and in assigning the morphological stage of the seal, and that changes of markings over a period of three years were insufficient to affect matching success. The certainty of identifying a seal was not dependent on the number of slides used but on distinctiveness of the markings and the quality of the slides taken. Capture-recapture abundance estimates were biased upwards when including poor quality slides. The exclusive use of excellent- and good-quality slides provided the best estimates. The proportion of distinctive seals varied between morphological stages and was significantly lower in juveniles. When including the identification histories of juveniles, the heterogeneity of capture probabilities was higher. Therefore, abundance estimates were less biased when all juveniles were considered as non-distinctive seals. Reliable abundance estimates required a balance between duration of capture occasions and time interval between these. C1 Univ Barcelona, Fac Biol, Dept Biol Anim, E-08028 Barcelona, Spain. RP Forcada, J (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. EM jforcada@ucsd.edu RI Aguilar, Alex/L-1283-2014 OI Aguilar, Alex/0000-0002-5751-2512 NR 41 TC 34 Z9 38 U1 1 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0824-0469 EI 1748-7692 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 2000 VL 16 IS 4 BP 767 EP 793 DI 10.1111/j.1748-7692.2000.tb00971.x PG 27 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 362MK UT WOS:000089781600005 ER PT J AU Jefferson, TA AF Jefferson, TA TI Websteris whales and dolphins of the world SO MARINE MAMMAL SCIENCE LA English DT Software Review C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Jefferson, TA (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 2000 VL 16 IS 4 BP 844 EP 846 PG 3 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 362MK UT WOS:000089781600012 ER PT J AU Becker, PR AF Becker, PR TI Concentration of chlorinated hydrocarbons and heavy metals in Alaska Arctic marine mammals SO MARINE POLLUTION BULLETIN LA English DT Article DE Alaska-Arctic; cetaceans; marine mammals; chlorinated hydrocarbons; chlorinated pesticides; heavy metals; pinnipeds; polychlorinated biphenyls ID WHALES DELPHINAPTERUS-LEUCAS; SEALS CALLORHINUS-URSINUS; LAWRENCE BELUGA WHALES; ORGANOCHLORINE CONTAMINANTS; ENVIRONMENTAL CONTAMINANTS; TRACE-METALS; HARBOR SEALS; WEST-COAST; TISSUES; ELEMENTS AB Over the last decade, a baseline database on anthropogenic contaminants in Alaska marine mammals has been developing through the efforts of several independent investigations as well as larger research programs, Although still somewhat limited in scope, the largest amount of data exists for polychlorinated biphenyls (PCBs), DDT, mercury, and cadmium in walrus, beluga whale, bowhead whale, and ringed seal. Because of their relatively large contribution to the total chlorinated hydrocarbon levels in Arctic species, chlordane and toxaphene are two pesticides that are also gaining attention, Comparison of the Alaska database with the results of studies conducted in Canada and Greenland, indicates that patterns of many accumulative substances are quite similar in species that occur across the North American Arctic. (C) 2000 Elsevier Science Ltd, All rights reserved. C1 USA, Waterways Expt Stn, CEWES,ER,C, Vicksburg, MS 39180 USA. RP Becker, PR (reprint author), NIST, Charleston Lab, 219 Ft Johnson Rd, Charleston, SC 29412 USA. EM paul.beckler@nist.gov NR 66 TC 25 Z9 26 U1 4 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD OCT PY 2000 VL 40 IS 10 BP 819 EP 829 DI 10.1016/S0025-326X(00)00076-X PG 11 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 370TA UT WOS:000165137300013 ER PT J AU Mitch, MG Zimmerman, BE Lamperti, PJ Seltzer, SM Coursey, BM AF Mitch, MG Zimmerman, BE Lamperti, PJ Seltzer, SM Coursey, BM TI Well-ionization chamber response relative to NIST air-kerma strength standard for prostate brachytherapy seeds SO MEDICAL PHYSICS LA English DT Article DE air-kerma strength; brachytherapy; iodine-125; ionization chamber; palladium-103 AB The response of well-ionization chambers to the emissions of Pd-103 and I-125 radioactive seed sources used in prostate cancer brachytherapy has been measured. Calibration factors relating chamber response (current or dial setting) to measured air-kerma strength have been determined for seeds from nine manufacturers, each with different designs. Variations in well-ionization chamber response relative to measured air-kerma strength have been observed because of differences in the emitted energy spectrum due to bath the radionuclide support material (I-125 seeds) and the mass ratio of Pd-103 to Pd-102 (Pd-103 seeds). Obtaining accurate results from quality assurance measurements using well-ionization chambers at a therapy clinic requires knowledge of such differences in chamber response as a function of seed design. [S0094-2405(00)00910-X]. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. RP Mitch, MG (reprint author), Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 4 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD OCT PY 2000 VL 27 IS 10 BP 2293 EP 2296 DI 10.1118/1.1290715 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 367YG UT WOS:000090089500012 PM 11099196 ER PT J AU Beckermann, C Gu, JP Boettinger, WJ AF Beckermann, C Gu, JP Boettinger, WJ TI Development of a freckle predictor via Rayleigh number method for single-crystal nickel-base superalloy castings SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PB-SN ALLOYS; CHANNEL FORMATION; DIRECTIONAL SOLIDIFICATION; THERMOSOLUTAL CONVECTION; MULTICOMPONENT ALLOYS; NONLINEAR-ANALYSIS; ARRAYED GROWTH; BINARY-ALLOYS; MUSHY LAYERS; MACROSEGREGATION AB A Rayleigh number based criterion is developed for predicting the formation of freckles in Ni-base superalloy castings. This criterion relies on finding the maximum local Rayleigh number in the mush, where the ratio of the driving buoyancy force to the retarding frictional force is the largest. A critical Rayleigh number for freckle formation of approximately 0.25 is found from available experimental data on directional solidification of a Ni-base superalloy. If the Rayleigh number in a superalloy casting is below this critical value, freckles are not expected to form, Full numerical simulations of freckling in directional solidification of superalloys are conducted for a large variety of casting conditions, alloy compositions, and inclinations of the system with respect to gravity. For the vertical cases, the Rayleigh numbers at the starting points of the predicted freckles are in good agreement with the critical value established from the experiments. The simulations confirm that the same critical Rayleigh number applies to different superalloys, The simulations for inclined domains show that even a small amount of inclination (less than 10 deg) significantly lowers the critical Rayleigh number and moves the freckles to the sidewall of the casting, where the mushy zone has advanced the most relative to gravity. In application of the Rayleigh number criterion to complex-shaped superalloy castings, the absence of freckles near upper and lower boundaries and in sections of insufficient cross-sectional area or height needs to be taken into account as well, The criterion can be used to study the tradeoffs between different superalloy compositions, applied temperature gradients, and casting speeds. Additional experiments, in particular for other superalloys and for a range of inclinations, are desirable to confirm the critical Rayleigh numbers found in the present study. C1 Univ Iowa, Dept Mech Engn, Iowa City, IA 52242 USA. PCC Struct Inc, Portland, OR 97206 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Beckermann, C (reprint author), Univ Iowa, Dept Mech Engn, Iowa City, IA 52242 USA. RI Beckermann, Christoph/F-7158-2010 OI Beckermann, Christoph/0000-0002-9976-0995 NR 35 TC 103 Z9 106 U1 3 U2 33 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD OCT PY 2000 VL 31 IS 10 BP 2545 EP 2557 DI 10.1007/s11661-000-0199-7 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 364WQ UT WOS:000089917400015 ER PT J AU Rodriguez, H Akman, SA Holmquist, GP Wilson, GL Driggers, WJ LeDoux, SP AF Rodriguez, H Akman, SA Holmquist, GP Wilson, GL Driggers, WJ LeDoux, SP TI Mapping oxidative DNA damage using ligation-mediated polymerase chain reaction technology SO METHODS-A COMPANION TO METHODS IN ENZYMOLOGY LA English DT Article ID MITOCHONDRIAL-DNA; HUMAN-CELLS; SUBSTRATE-SPECIFICITY; NUCLEOTIDE RESOLUTION; RINR-38 CELLS; REPAIR; GENE; MUTATIONS; ADDUCTS; OXYGEN AB Reactive oxygen species induce a pharmacopoeia of oxidized bases in DNA. DNA can be cleaved at most of the sites of these modified bases by digestion with a combination of two base excision repair glycosylases from Escherichia coli, Fpg glycosylase, and endonuclease iii. The frequency of the resulting glycosylase-dependent 5'-phosphoryl ends can be mapped at nucleotide resolution along a sequencing gel autoradiogram by a genomic sequencing technique, ligation-mediated polymerase chain reaction (LMPCR). In cultured rat cells, the frequency of endogenous oxidized bases in mitochondrial DNA is sufficiently high, about one oxidized base per 100 kb, to be directly mapped from 0.1 mug of total cellular DNA preparations by LMPCR. Nuclear DNA has a lower frequency of endogenous oxidative base damage which cannot be mapped from 1-mug preparations of total cellular DNA. Preparative gel electrophoresis of the PGK1 and p53 genes from 300 mug of restriction endonuclease-digested genomic DNA showed a 25-fold enrichment for the genes and, after endonuclease digestion followed by LMPCR, gave sufficient signal to map the frequency of oxidized bases from human cells treated with 50 muM H2O2. (C) 2000 Academic Press. C1 City Hope Natl Med Ctr, Beckman Res Inst, Dept Biol, Duarte, CA 91010 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Wake Forest Univ, Ctr Comprehens Canc, Dept Canc Biol, Winston Salem, NC 27157 USA. Univ S Alabama, Coll Med, Dept Struct & Cellular Biol, Mobile, AL 36888 USA. RP Holmquist, GP (reprint author), City Hope Natl Med Ctr, Beckman Res Inst, Dept Biol, Duarte, CA 91010 USA. FU NCI NIH HHS [1P01CA69449]; NIEHS NIH HHS [ES034656, ES5865] NR 38 TC 14 Z9 14 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1046-2023 J9 METHODS JI Methods PD OCT PY 2000 VL 22 IS 2 BP 148 EP 156 DI 10.1006/meth.2000.1055 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 366BJ UT WOS:000089984700006 PM 11020329 ER PT J AU Szunyogh, I Toth, Z Morss, RE Majumdar, SJ Etherton, BJ Bishop, CH AF Szunyogh, I Toth, Z Morss, RE Majumdar, SJ Etherton, BJ Bishop, CH TI The effect of targeted dropsonde observations during the 1999 winter storm reconnaissance program SO MONTHLY WEATHER REVIEW LA English DT Article ID ADAPTIVE OBSERVATIONS; SINGULAR VECTORS; ANALYSIS SYSTEM; SENSITIVITY; TRACK; NCEP AB In this paper, the effects of targeted dropsonde observations on operational global numerical weather analyses and forecasts made at the National Centers for Environmental Prediction (NCEP) are evaluated. The data were collected during the 1999 Winter Storm Reconnaissance field program at locations that were found optimal by the ensemble transform technique for reducing specific forecast errors over the continental United States and Alaska. Two parallel analysis-forecast cycles are compared; one assimilates all operationally available data including those from the targeted dropsondes, whereas the other is identical except that it excludes all dropsonde data collected during the program. It was found that large analysis errors appear in areas of intense baroclinic energy conversion over the northeast Pacific and are strongly associated with errors in the first-guess field. The "signal," defined by the difference between analysis-forecast cycles with and without the dropsonde data, propagates at an average speed of 30 degrees per day along the storm track to the east. Hovmoller diagrams and eddy statistics suggest that downstream development plays a significant role in spreading out the effect of the dropsondes in space and time. On average, the largest rms surface pressure errors are reduced by 10%-20% associated with the eastward-propagating leading edge of the signal. The dropsonde data seem to be more effective in reducing forecast errors when zonal how prevails over the eastern Pacific. Results from combined verification statistics (based on surface pressure, tropospheric winds, and precipitation amount) indicate that the dropsonde data improved the forecasts in 18 of the 25 targeted cases, while the impact was negative (neutral) in only 5 (2) cases. C1 Natl Ctr Environm Predict, EMC, Camp Springs, MD 20746 USA. Natl Ctr Environm Predict, Gen Sci Corp, Camp Springs, MD 20746 USA. MIT, Program Atmospheres Ocean & Climate, Cambridge, MA 02139 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Eotvos Lorand Univ, Dept Meteorol, Budapest, Hungary. RP Szunyogh, I (reprint author), Natl Ctr Environm Predict, EMC, 5200 Auth Rd,WWB,Room 207, Camp Springs, MD 20746 USA. EM Istvan.Szunyogh@noaa.gov RI Szunyogh, Istvan/G-9248-2012; Etherton, Brian/E-7419-2015; Toth, Zoltan/I-6624-2015 OI Etherton, Brian/0000-0002-2760-0095; Toth, Zoltan/0000-0002-9635-9194 NR 40 TC 90 Z9 105 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2000 VL 128 IS 10 BP 3520 EP 3537 DI 10.1175/1520-0493(2000)128<3520:TEOTDO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367AY UT WOS:000090040300009 ER PT J AU Cortinas, J AF Cortinas, J TI A climatology of freezing rain in the Great Lakes region of North America SO MONTHLY WEATHER REVIEW LA English DT Article ID WINTER STORMS; PRECIPITATION; CYCLONES AB A 15-yr climatology of freezing rain surrounding the Great Lakes region of North America has been constructed using data from rawinsondes, surface stations, and gridded reanalyses from the National Centers for Environmental Prediction. This climatology reveals that there is a general increase in the freezing-rain frequency from west to east; however, the distribution shows large spatial and temporal variability. Most freezing-rain events are short lived and occur near sunrise between the months of December and March. Continuous freezing rain typically lasts less than 1 h, with 7% of events lasting longer than 5 h. Most freezing rain is associated with extratropical cyclones, occurring northeast of the cyclone center in the presence of midlevel upward vertical motion, and air that is nearly saturated at low and midlevels, subfreezing near the surface, and warm (>0 degreesC) at low levels (approximate to 850 hPa). The location of the mean extratropical cyclone track during freezing-rain events in the Great Lakes region east of 87 degreesW and the climatological cyclone track during January partially explains the eastward increase in freezing-rain frequency. Additionally, it appears that the proximity of the Atlantic Ocean to the area east of 81 degreesW provides a large moisture source for these events, while western events appear to receive moisture from the distant Gulf of Mexico. The Great Lakes appear to have some effect on reducing the occurrence of freezing rain very near the western shores. C1 Univ Colorado, Cooperat Inst Mesoscale Meteorol Studies, NOAA, Norman, OK 73069 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Cortinas, J (reprint author), Univ Colorado, Cooperat Inst Mesoscale Meteorol Studies, NOAA, 1313 Halley Circle, Norman, OK 73069 USA. NR 34 TC 37 Z9 38 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2000 VL 128 IS 10 BP 3574 EP 3588 DI 10.1175/1520-0493(2001)129<3574:ACOFRI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367AY UT WOS:000090040300012 ER PT J AU Lu, CG Xie, YF AF Lu, CG Xie, YF TI Spatial computational modes in the centered finite-differencing schemes SO MONTHLY WEATHER REVIEW LA English DT Article AB The computational modes associated with a centered finite-differencing scheme in space are studied. The existence and impact of these computational modes in a numerical solution are demonstrated with the use of theoretical analyses and numerical experiments. The results show that the computational modes due to a spatial discretization can have a detrimental effect on the numerical solution in situations where flows are evolved near shock (or having large spatial derivative). The numerical diffusion can reduce the impact of the computational modes, but can also impose an adverse effect on the physical modes. C1 NOAA, OAR, Forecast Syst Lab, Boulder, CO 80303 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO USA. RP Lu, CG (reprint author), NOAA, OAR, Forecast Syst Lab, Boulder, CO 80303 USA. RI Xie, Yuanfu/G-4413-2015 NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2000 VL 128 IS 10 BP 3674 EP 3682 DI 10.1175/1520-0493(2000)128<3674:SCMITC>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367AY UT WOS:000090040300020 ER PT J AU Avila, LA Pasch, RJ Jiing, JG AF Avila, LA Pasch, RJ Jiing, JG TI Atlantic tropical systems of 1996 and 1997: Years of contrasts SO MONTHLY WEATHER REVIEW LA English DT Article ID PACIFIC HURRICANE SEASON AB A total of 62 and 63 tropical waves were counted in the Atlantic from May to November during 1996 and 1997, respectively. These waves led to the formation of 12 of the 13 total number of tropical cyclones in 1996 and only 3 of 7 tropical cyclones in 1997. All of the tropical depressions became tropical storms in 1996 and only one failed to become a named storm in 1997. On average, 62% of the Atlantic tropical depressions develop from tropical waves. These waves contributed to the formation of 92% of the eastern Pacific tropical cyclones in 1996 and 83% in 1997. Tropical waves and their environment during the 1996 and 1997 seasons are discussed. C1 NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, Miami, FL 33165 USA. RP Avila, LA (reprint author), NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 18 TC 18 Z9 18 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2000 VL 128 IS 10 BP 3695 EP 3706 DI 10.1175/1520-0493(2000)128<3695:ATSOAY>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367AY UT WOS:000090040300023 ER PT J AU Currie, LA Klinedinst, DB Burch, R Feltham, N Dorsch, R AF Currie, LA Klinedinst, DB Burch, R Feltham, N Dorsch, R TI Authentication and dating of biomass components of industrial materials; links to sustainable technology SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Accelerator Mass Spectrometry CY SEP 06-10, 1999 CL VIENNA, AUSTRIA DE dual isotopic authentication; biomass feedstock; renewable resource; 1,3-propanediol; polypropylene terephthalate; C-14 dating year of crop growth; isotopic-stoichiometric mass balance; high accuracy isotopic (C-13-C-14) metrology AB There are twin pressures mounting in US industry for increased utilization of biomass feedstocks and biotechnology in production. The more demanding pressure relates to economic sustainability, that is, because of increased competition globally, businesses will fail unless a minimum margin of profit is maintained while meeting the demands of consumers for less expensive products. The second pressure relates to "Green Technology" where environmental sustainability, linked for example to concerns about climate change and the preservation of natural resources, represents a worldwide driving force to reduce the consumption of fossil hydrocarbons. The resulting transition of biomass production in the industrial plant, as opposed to the agricultural plant, has resulted in an increasing need for isotopic methods of authenticating and dating feedstocks, intermediates and industrial products. The research described represents a prototypical case study leading to the definition of a unique dual isotopic (C-13, C-14) signature or "fingerprint" for a new biomass-based commercial polymer, polypropylene terephthalate (3GT). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Dupont Co, Wilmington, DE 19880 USA. RP Currie, LA (reprint author), Natl Inst Stand & Technol, 100 Bureau Dr Stop 8370, Gaithersburg, MD 20899 USA. NR 5 TC 14 Z9 16 U1 1 U2 5 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 OCT PY 2000 VL 172 BP 281 EP 287 DI 10.1016/S0168-583X(00)00218-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 372JR UT WOS:000165231000048 ER PT J AU Currie, LA Kessler, JD Marolf, JV McNichol, AP Stuart, DR Donohue, JC Donahue, DJ Burr, GS Biddulph, D AF Currie, LA Kessler, JD Marolf, JV McNichol, AP Stuart, DR Donohue, JC Donahue, DJ Burr, GS Biddulph, D TI Low-level (submicromole) environmental C-14 metrology SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Accelerator Mass Spectrometry CY SEP 06-10, 1999 CL VIENNA, AUSTRIA DE environmental C-14; dilution AMS; submicromole C-14 measurement; modern carbon quantification limit; black carbon; Greenland snowy; on-line mass spectrometry ID NOSAMS AB Accelerator mass spectrometry (AMS) measurements of environmental C-14 have been employed during the past decade at the several micromole level (tens of mug carbon), but advanced research in the atmospheric and marine sciences demands still higher (mug) sensitivity, an extreme example being the determination of C-14 in elemental or "black" carbon (BC) at levels of 2-10 mug per kg of Greenland snow and ice (Currie et al., 1998). A fundamental limitation for C-14 AMS is Poisson counting statistics, which sets in at about 1 mug modern-C. Using the small sample (25 mug) AMS target preparation facility at NOSAMS (Pearson et al., 1998), and the microsample combustion-dilution facility at NIST, we have demonstrated an intrinsic modern-C quantification limit (m(Q)) of ca. 0.9 mug, based on a 1-parameter fit to the empirical AMS variance function. (For environmental C-14, the modern carbon quantification limit is defined as that mass (m(Q)) corresponding to 10% relative standard deviation (rsd) for the fraction of modern carbon, sigma(*f(M))/(f(M).) Stringent control, required for quantitative dilution factors (DL), is achieved with the NIST on-line manometric/mass spectrometry facility that compensates also for unsuspected trace impurities from vigorous chemical processing (e.g., acid digestion). Our current combustion blank is trivial (mean: 0.16+/-0.02 mug C, n = 13) but lognormally distributed (dispersion [sigma]: 0.07 +/- 0.01 mug). An iterative numerical expression is introduced to assess the quantitative impacts of fossil and modern carbon blank components on m(Q); and a new "clean chemistry" BC processing system is described for the minimization of such blanks. For the assay of soot carbon in Greenland snow/ice, the overall processing blank has been reduced from nearly 7 mug total carbon to less than 1 mug, and is undetectable for BC. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Woods Hole Oceanog Inst, NOSAMS, Woods Hole, MA 02543 USA. Univ Arizona, NSF, Arizona AMS Facil, Tucson, AZ 85721 USA. RP Currie, LA (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8370, Gaithersburg, MD 20899 USA. NR 11 TC 20 Z9 20 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 OCT PY 2000 VL 172 BP 440 EP 448 DI 10.1016/S0168-583X(00)00217-2 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 372JR UT WOS:000165231000076 ER PT J AU Broecker, WS Peng, TH AF Broecker, WS Peng, TH TI Comparison of Ar-39 and C-14 ages for waters in the deep ocean SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Accelerator Mass Spectrometry CY SEP 06-10, 1999 CL VIENNA, AUSTRIA DE oceans; thermohaline structure and circulation ID SOUTHERN-OCEAN AB Ar-39 ages on ocean water samples are consistently younger than C-14 ages. The difference is the result of diffusive mixing in the sea which has a greater impact on ages based on short-lived than those based on long-lived radiotracers. It is clear that a more dense survey of Ar-39 with higher accuracy measurements would prove of great value in constraining ocean general circulation models. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Broecker, WS (reprint author), Columbia Univ, Lamont Doherty Earth Observ, 61 Route 9W,POB 100, Palisades, NY 10964 USA. NR 11 TC 19 Z9 19 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 OCT PY 2000 VL 172 BP 473 EP 478 DI 10.1016/S0168-583X(00)00272-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 372JR UT WOS:000165231000082 ER PT J AU Klinedinst, DB Currie, LA AF Klinedinst, DB Currie, LA TI Radiocarbon blank correction: Methodologies and limitations in a major urban study of carbonaceous aerosols SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Accelerator Mass Spectrometry CY SEP 06-10, 1999 CL VIENNA, AUSTRIA DE AMS; radiocarbon; atmospheric particulate; blank correction; NFRAQS ID ACCELERATOR MASS-SPECTROMETRY; MICROGRAM SAMPLES; SYSTEM AB The Northern Front Range Air Quality Study (NFRAQS) was the latest and most ambitious of a series of efforts to apportion sources of carbonaceous aerosol "soot" in the Denver, Colorado metropolitan area. The study was mandated by the Colorado State Legislature as a result of the continuing impact of aerosol carbon on visibility in the region. Apportionment of fossil and biomass carbon was based on blank-corrected values of carbon mass concentrations (mug/m(3)) and C-14 data (f(M), fraction of modem carbon) of a selected subset of the samples collected in conjunction with this program. Over 100 C-14 measurements were made on size segregated (less than or equal to2.5 mum diameter) atmospheric aerosol samples collected during the summer of 1996 and the winter of 1996-1997. The reported f(M) values required correction for both the mass and f(M) of the overall carbon blank. Lack of direct f(M) data for the field blanks had a substantial effect on the estimated uncertainty of the final results, and in a few of the most extreme cases blank-corrected f(M) data had to be designated as "indeterminate". Blank correction procedures and limitations will be illustrated with quantitative data from the NFRAQS study. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Klinedinst, DB (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Mail Stop 8372, Gaithersburg, MD 20899 USA. NR 24 TC 6 Z9 6 U1 0 U2 4 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 OCT PY 2000 VL 172 BP 545 EP 550 DI 10.1016/S0168-583X(00)00233-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 372JR UT WOS:000165231000093 ER PT J AU Campbell, H Herrick, SF Squires, D AF Campbell, H Herrick, SF Squires, D TI The role of research in fisheries management: The conservation of dolphins in the eastern tropical Pacific and the exploitation of Southern Bluefin Tuna in the southern ocean SO OCEAN DEVELOPMENT AND INTERNATIONAL LAW LA English DT Article; Proceedings Paper CT ECDPM-ISNAR Expert Consultation on Closing the Loop CY NOV 10-11, 1997 CL MASTRICHT, NETHERLANDS DE scientific research; policy formation; property rights; fisheries ID STENELLA; IMPACTS; SCHOOL; SIZE AB This article uses two case studies to assess the role of research in policy formation and fishery management. One study focuses on measures to limit the mortality of dolphins taken when tuna are harvested in the eastern tropical Pacific. The other studies measures taken to limit harvests of Southern Bluefin Tuna. Both of these fisheries involve fugitive resources and transboundary, resources spreading across both national exclusive economic zones and the high seas. Both fisheries were initially based on open access, but public policy has led to greater exclusive use through individual transferable quotas for Southern Bluefin Tuna and dolphin mortality limits. A number of policy conclusions are drawn. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Univ Queensland, Dept Econ, Brisbane, Qld, Australia. RP Squires, D (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 70 TC 5 Z9 6 U1 0 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0090-8320 J9 OCEAN DEV INT LAW JI Ocean Dev. Int. Law PD OCT-DEC PY 2000 VL 31 IS 4 BP 347 EP 375 PG 29 WC International Relations; Law SC International Relations; Government & Law GA 396PM UT WOS:000166645800002 ER PT J AU Wooldridge, C AF Wooldridge, C TI The new regulatory framework for commercial remote sensing SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Editorial Material C1 Natl Ocean & Atmospher Adm, Silver Spring, MD 20910 USA. RP Wooldridge, C (reprint author), Natl Ocean & Atmospher Adm, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD OCT PY 2000 VL 66 IS 10 BP 1171 EP + PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 358FC UT WOS:000089546300002 ER PT J AU Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Takacs, E AF Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Takacs, E TI Absolute measurement of the resonance lines in heliumlike vanadium on an electron-beam ion trap SO PHYSICAL REVIEW A LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; X-RAY-DIFFRACTION; 1S LAMB SHIFT; PRECISION-MEASUREMENT; ISOELECTRONIC SEQUENCE; EMISSION LINE; GROUND-STATE; DIRAC-FOCK; ENERGY; TRANSITIONS AB Absolute measurements of the energies of resonance lines in heliumlike vanadium on an electron-beam ion trap are reported. The 1s2p P-1(1)-->1s(2), 1s2p P-3(2)-->1s(2) (1s2p P-3(1)-->1s(2) and 1s2p P-3(0)-->1s(2)) blend and 1s2s S-3(1)-->1s(2) transitions are 5205.10 +/- 0.14 eV, 5189.12 +/- 0.21 eV, 5180.22 +/- 0.17 eV, and 5153.82 +/- 0.14 eV, respectively. This agrees with recent theoretical calculations and the experimental precision lies at the same level as the current uncertainty in theory (0.1 eV). These measurements represent a 5.7-8% determination of the QED contribution to the transition energies and are the most precise measurements of heliumlike resonance lines in the Z=19-31 range. The measurement of the 1s2s S-3(1)-->1s(2) transition is also sensitive to the 1s2s S-3(1) QED contribution at the 40% level. The intensity of the strong 1s2p P-3(1)-->1s(2) component of the blend compared to the total blend intensity is 94% +/- 12%. This is in accord with current theoretical predictions but disagrees with an earlier reported ratio. C1 Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Debrecen, Inst Expt Phys, H-4026 Debrecen, Hungary. RP Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 55 TC 44 Z9 44 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2000 VL 62 IS 4 AR 042501 DI 10.1103/PhysRevA.62.042501 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 360VU UT WOS:000089688700031 ER PT J AU Larson, A Djuric, N Zong, W Greene, CH Orel, AE Al-Khalili, A Derkatch, AM Le Padellec, A Neau, A Rosen, S Shi, W Vikor, L Danared, H af Ugglas, M Larsson, M Dunn, GH AF Larson, A Djuric, N Zong, W Greene, CH Orel, AE Al-Khalili, A Derkatch, AM Le Padellec, A Neau, A Rosen, S Shi, W Vikor, L Danared, H af Ugglas, M Larsson, M Dunn, GH TI Resonant ion-pair formation in electron collisions with HD+ and OH+ SO PHYSICAL REVIEW A LA English DT Article ID DISSOCIATIVE RECOMBINATION; CROSS-SECTIONS; DIELECTRONIC RECOMBINATION; RYDBERG STATES AB Resonant ion-pair formation from collisions of electrons with electronic and vibronic ground-state diatomic molecular ions has been studied in the present work for HD+ and OH+. The cross section for HD+ has a magnitude of the order of 3 x 10(-19) cm(2) and is characterized by an energy threshold and 14 resolved peaks in the energy range up to 16 eV. A theoretical study confirms that the structures derive primarily from quantum interference of the multiple dissociation pathways. Measurements for OH+ reveal that the cross section for H+ and O- formation is lower than 10(-21) cm(2) at energies of 6 and 12 eV. C1 Royal Inst Technol, Dept Phys, S-10044 Stockholm, Sweden. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. Univ Toulouse 3, LCAR, UMR 5589, F-31062 Toulouse 4, France. Manne Siegbahn Lab, S-10405 Stockholm, Sweden. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. RP Larson, A (reprint author), Royal Inst Technol, Dept Phys, S-10044 Stockholm, Sweden. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 29 TC 12 Z9 12 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 OCT PY 2000 VL 62 IS 4 AR 042707 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 360VU UT WOS:000089688700046 ER PT J AU Yurovsky, VA Ben-Reuven, A Julienne, PS Williams, CJ AF Yurovsky, VA Ben-Reuven, A Julienne, PS Williams, CJ TI Atom loss and the formation of a molecular Bose-Einstein condensate by Feshbach resonance SO PHYSICAL REVIEW A LA English DT Article ID COLLISIONS AB In experiments conducted recently at MIT on Na Bose-Einstein condensates [S. Inouye et nl., Nature (London) 392, 151 (1998); J. Stenger ct al., Phys. Rev. Lett. 82, 2422 (1999)], large loss rates were observed when a time-varying magnetic field was used to tune a molecular Feshbach resonance state near the state of a pair of atoms in the condensate. A collisional deactivation mechanism affecting a temporarily formed molecular condensate [see V. A. Yurovsky, A. Ben-Reuven, P. S. Julienne and C. J. Williams, Phys. Rev. A 60, R765 (1999)], studied here in more detail, accounts for the results of the slow-sweep experiments. A best fit to the MIT data yields a rate coefficient for deactivating atom-molecule collisions of 1.6 x 10(-10) cm(3)/s. In the case of the fast-sweep experiment, a study is carried out of the combined effect of two competing mechanisms, the three-atom (atom-molecule) or four-atom (molecule-molecule) collisional deactivation versus a process of two-atom crap-state excitation by curve crossing [F. H. Mies, P. S. Julienne, and E. Tiesinga, Phys. Rev. A 61, 022721 (2000)]. It is shown that both mechanisms contribute to the loss comparably and nonadditively. C1 Tel Aviv Univ, Sch Chem, IL-69978 Tel Aviv, Israel. Natl Inst Stand & Technol, Atom Phys Div, Bethesda, MD 20889 USA. RP Yurovsky, VA (reprint author), Tel Aviv Univ, Sch Chem, IL-69978 Tel Aviv, Israel. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 25 TC 36 Z9 36 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2000 VL 62 IS 4 AR 043605 DI 10.1103/PhysRevA.62.043605 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 360VU UT WOS:000089688700069 ER PT J AU Zheludev, A Masuda, T Tsukada, I Uchiyama, Y Uchinokura, K Boni, P Lee, SH AF Zheludev, A Masuda, T Tsukada, I Uchiyama, Y Uchinokura, K Boni, P Lee, SH TI Magnetic excitations in coupled Haldane spin chains near the quantum critical point SO PHYSICAL REVIEW B LA English DT Article ID DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; NEUTRON-SCATTERING; GAP ANTIFERROMAGNETS; SIGMA-MODEL; DYNAMICS; CSNICL3; INTEGER; Y2BANIO5; SYSTEMS; CSMNI3 AB Two quasi-one-dimensional S = 1 quantum antiferromagnetic materials, PbNi2V2O8 and SrNi2V2O8, are studied by inelastic neutron scattering on powder samples. A simple model Hamiltonian is proposed for the two systems and used to analyze the data. Quantitative information on in-chain and interchain interactions obtained from this analysis is discussed in the context of qualitatively different ground-state properties: magnetic long-range order in SrNi2V2O8 and disordered "spin liquid" Haldane-gap state in PbNi2V2O8. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Tokyo, Dept Adv Mat Sci, Tokyo, Japan. RP Zheludev, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 32 TC 52 Z9 52 U1 0 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2000 VL 62 IS 13 BP 8921 EP 8930 DI 10.1103/PhysRevB.62.8921 PG 10 WC Physics, Condensed Matter SC Physics GA 361QH UT WOS:000089733800069 ER PT J AU Jentschura, UD AF Jentschura, UD TI Resummation of nonalternating divergent perturbative expansions SO PHYSICAL REVIEW D LA English DT Article ID HYDROGEN-ATOM; HIGH-ORDER; FIELD AB A method for the resummation of a nonalternating divergent perturbation series is described. The procedure constitutes a generalization of the Borel-Pade method. Of crucial importance is a special integration contour in the complex plane. Nonperturbative imaginary contributions can be inferred from the purely real perturbative coefficients. A connection is drawn from the quantum field theoretic problem of resummation to divergent perturbative expansions in other areas of physics. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden, Germany. RP Jentschura, UD (reprint author), Natl Inst Stand & Technol, Mail Stop 8401, Gaithersburg, MD 20899 USA. EM ulj@nist.gov NR 27 TC 18 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 1 PY 2000 VL 62 IS 7 AR 076001 DI 10.1103/PhysRevD.62.076001 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 361XK UT WOS:000089749400074 ER PT J AU Lue, L Evans, DJ AF Lue, L Evans, DJ TI Configurational temperature for systems with constraints SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-DYNAMICS; ALGORITHM; SIMULATIONS; ALKANES AB A general method is developed for constructing configurational expressions for the temperature of systems with constraints. As an example, this method is applied to molecular systems with bonding constraints, and an explicit formula for the temperature, in terms of only the configurational variables of the system, is derived. This formula is tested against molecular-dynamics simulations for freely jointed Lennard-Jones 8-mer chains and Monte Carlo simulations for a system of diatomic Lennard-Jones molecules. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Lue, L (reprint author), Univ Manchester, Inst Sci & Technol, Dept Chem Engn, POB 88, Manchester M60 1QD, Lancs, England. RI Lue, Leo/E-7846-2011; Evans, Denis/C-1653-2009 OI Lue, Leo/0000-0002-4826-5337; NR 7 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD OCT PY 2000 VL 62 IS 4 BP 4764 EP 4768 DI 10.1103/PhysRevE.62.4764 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 365XY UT WOS:000089976800041 ER PT J AU Zou, X Wang, B Liu, H Anthes, RA Matsumura, T Zhu, YJ AF Zou, X Wang, B Liu, H Anthes, RA Matsumura, T Zhu, YJ TI Use of GPS/MET refraction angles in three-dimensional variational analysis SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE GPS/MET refraction angles; ray tracing; variational analysis ID GLOBAL POSITIONING SYSTEM; EARTHS ATMOSPHERE; ASSIMILATION; ADJOINT; MODEL; IMPLEMENTATION; SENSITIVITY AB The Spectral Statistical Interpolation (SSI) analysis system of the National Centers for Environmental Prediction (NCEP) is modified to include GPS/MET data (meteorological data from the Global Positioning Satellite system) using a GPS ray-tracing operator. The new system is tested by incorporating 30 actual GPS/MET observations of refraction angles obtained during the GPS/MET experiment. This is the first time that real radio occultation refraction angles and refractivities have been incorporated into a three-dimensional variational analysis system. We examine the magnitude and the vertical distribution of the analysis adjustments that result from using refraction-angle observations in the NCEP SSI analysis system. The average magnitudes of the adjustments in the temperature and specific-humidity fields are approximately 0.4 degC and 0.6 g kg(-1), respectively. Individual changes can be as large as 4 degC and 4 g kg(-1), respectively. The greatest adjustments to the temperature occur in the middle and upper troposphere and stratosphere, while the major changes in specific humidity occur in the lower troposphere. An assessment of the impact of the GPS/MET observations on the analysis, verified by conventional (mostly radiosonde) data, is difficult because of the small number of GPS/MET data used. Nevertheless, it is found that, even over data-rich regions (regions containing many radiosonde observations), and even when the verification data were the radiosonde data themselves, the use of GPS/MET refraction angles makes a slight improvement, overall, to the analysed temperatures and winds. The impact on the water-vapour analyses, again as measured against radiosonde data, is mixed, with improvements shown in some layers and degradation in others. Compared with the background field, the use of refraction angles from one occultation results in an analysis whose simulated refraction angles are much closer to the withheld GPS/MET refraction angles at the two nearby occultation locations, and whose temperature and moisture profiles are also closer to those resulting from the direct assimilation of the two withheld occultations. Although the forward model used in this study, with the ray tracing being carried out in a two-dimensional plane, is much cheaper than a more accurate three-dimensional forward model, it is still quite expensive. In order to further reduce the computational requirement for the assimilation of GPS/MET data, we test a scheme in which the GPS/MET-retrieved refractivities (instead of refraction angles) are used above a selected height for each occultation. These heights are determined objectively based on the departures from spherical symmetry of the model held. It is shown that the mixed use of GPS/MET refraction angles and refractivities produces an analysis result similar to the one using refraction angles alone, while the computational cost is reduced by more than 30%. C1 Florida State Univ, Tallahassee, FL 32306 USA. Univ Corp Atmospher Res, Boulder, CO 80303 USA. Natl Ctr Environm Predict, Camp Springs, MD USA. RP Zou, X (reprint author), Florida State Univ, Tallahassee, FL 32306 USA. RI Wang, Bin/P-9121-2014; Wang, Bin/D-9724-2012 OI Wang, Bin/0000-0001-7374-3786; Wang, Bin/0000-0002-3133-7197 NR 22 TC 48 Z9 59 U1 0 U2 6 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2000 VL 126 IS 570 BP 3013 EP 3040 DI 10.1256/smsqj.57002 PN B PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 381VF UT WOS:000165783600002 ER PT J AU Nagy, V Sleptchonok, OF Desrosiers, MF Weber, RT Heiss, AH AF Nagy, V Sleptchonok, OF Desrosiers, MF Weber, RT Heiss, AH TI Advancements in accuracy of the alanine EPR dosimetry system Part III: Usefulness of an adjacent reference sample SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article DE alenine dosimetry; EPR; ESR; adjacent reference sample; accuracy; ruby AB High stability of the radiation-induced radicals in alanine and the high reproducibility of alanine response to radiation make it possible to determine radiation doses accurately with Electron Paramagnetic Resonance (EPR) spectral analysis. Small uncontrollable variations of the EPR spectrometer sensitivity, however, can significantly deteriorate the accuracy of the method. The errors due to these variations I-an be eliminated or markedly decreased if an adjacent reference sample (such as a synthetic ruby crystal) is permanently present in the cavity, and if ratios of the alanine and ruby signal amplitudes are used throughout the dosimetric session instead of the absolute alanine amplitudes. This paper addresses methodological aspects of using such adjacent reference samples in alanine dosimetry and provides illustrations of the usefulness of this technique. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Bruker Instruments Inc, EPR Div, Billerica, MA 01821 USA. RP Nagy, V (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 33 Z9 33 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD OCT PY 2000 VL 59 IS 4 BP 429 EP 441 DI 10.1016/S0969-806X(00)00275-9 PG 13 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 359QJ UT WOS:000089623300012 ER PT J AU Desrosiers, MF Nagy, VY Slepchonok, OF AF Desrosiers, MF Nagy, VY Slepchonok, OF TI Concerns regarding alanine dosimetry recent NIST publications on - Reply SO RADIATION PHYSICS AND CHEMISTRY LA English DT Letter C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Desrosiers, MF (reprint author), Natl Inst Stand & Technol, Ionizing Radiat Div, Room C229,Bldg 245, Gaithersburg, MD 20899 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD OCT PY 2000 VL 59 IS 4 BP 445 EP 447 DI 10.1016/S0969-806X(00)00313-3 PG 3 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 359QJ UT WOS:000089623300014 ER PT J AU Hamilton, CA AF Hamilton, CA TI Josephson voltage standards SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Review ID ZERO CURRENT BIAS; SERIES-ARRAY; 1 V; FREQUENCY RELATION; PHASE-LOCK; JUNCTIONS; 10-V; AC; BIPM; PRECISION AB This paper reviews the development and use of Josephson voltage standards over the last 30 years, including classical dc standards, programmable standards based on binary weighted arrays, pulse-driven delta-sigma standards for ac wave-form synthesis, and single-flux-quantum voltage multipliers. [S0034-6748(00)00810-8]. C1 Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. EM hamilton@boulder.nist.gov NR 115 TC 85 Z9 87 U1 3 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2000 VL 71 IS 10 BP 3611 EP 3623 AR PII [S0034-6748(00)00810-8] DI 10.1063/1.1289507 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 358JG UT WOS:000089554500001 ER PT J AU Neuman, JA Gao, RS Schein, ME Ciciora, SJ Holecek, JC Thompson, TL Winkler, RH McLaughlin, RJ Northway, MJ Richard, EC Fahey, DW AF Neuman, JA Gao, RS Schein, ME Ciciora, SJ Holecek, JC Thompson, TL Winkler, RH McLaughlin, RJ Northway, MJ Richard, EC Fahey, DW TI A fast-response chemical ionization mass spectrometer for in situ measurements of HNO3 in the upper troposphere and lower stratosphere SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NITRIC-ACID; UNITED-STATES; CHEMISTRY; MODEL AB A chemical ionization mass spectrometer instrument has been developed for in situ measurements of nitric acid (HNO3) in the upper troposphere and lower stratosphere from the NASA WB-57 aircraft. Fast and sensitive measurements of HNO3 are achieved by using a low surface area heated Teflon sampling inlet and detection techniques that employ ion-molecule reactions. Sensitivity to HNO3 is determined in flight by adding HNO3 from a calibrated HNO3 permeation source into the sample air flow, and instrument background is measured by displacing ambient air from the sampling inlet with a flow of dry nitrogen in the sampling inlet. Instrument temperatures, pressures, and gas flows are controlled in flight to maintain a constant detection sensitivity in a changing ambient operating environment. The initial performance of this new instrument is evaluated using HNO3 and ozone data obtained between 6 and 19 km during the 1999 NASA Atmospheric Chemistry of Combustion Emissions Near the Tropopause mission. The data reveal a sensitivity of 0.73 Hz/pptv, a detection limit of 30 pptv for 10 s integration times, and a fast time response (< 1 s). Further reductions in the background HNO3 signal will improve performance. (C) 2000 American Institute of Physics. [S0034-6748(00)01710-X]. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. RP Neuman, JA (reprint author), Univ Colorado, CIRES, Boulder, CO 80309 USA. RI Neuman, Andy/A-1393-2009; Gao, Ru-Shan/H-7455-2013; Ciciora, Steven/I-4916-2013; McLaughlin, Richard/I-4386-2013; Fahey, David/G-4499-2013 OI Neuman, Andy/0000-0002-3986-1727; Fahey, David/0000-0003-1720-0634 NR 17 TC 30 Z9 30 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2000 VL 71 IS 10 BP 3886 EP 3894 DI 10.1063/1.1289679 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 358JG UT WOS:000089554500046 ER PT J AU Crosby, MP Abu-Hilal, A Al-Homoud, A Erez, J Ortal, R AF Crosby, MP Abu-Hilal, A Al-Homoud, A Erez, J Ortal, R TI Interactions among scientists, managers and the public in defining research priorities and management strategies for marine and coastal resources: Is the Red Sea Marine Peace Park a new paradigm? SO WATER AIR AND SOIL POLLUTION LA English DT Article DE coral reef; Gulf of Aqaba; management; marine protected area; Red Sea; research; sustainable use ID CORAL AB It has been assumed that marine habitats and resources, especially, are almost unlimited, and that if one habitat became degraded or a particular fisheries resource depleted, there always would be another to replace it. Therefore, natural resource management principals are beginning to include human motivation and responses as part of the marine and coastal systems that are being studied and managed. Managers of marine resources face the challenge of balancing conservation and development objectives in the context of the inherent uncertainty of natural systems and the political and social pressures of human systems. Natural resource managers, scientists and the general public seem to share a vision for the future as a world in which societal and economic decisions will be strongly coupled with an increasingly comprehensive understanding of the environment. This in turn will lead to both socio-economic health and ecosystem health. A paradigm shift is being seen in the evolution of the role of scientists in society from simply observers of the natural world with tenuous linkages to resource managers and the public, to partners in modern society's quest for answers to pressing questions related to sustainable use and conservation of natural resources. A US Agency for International Development supported, joint effort between the US National Oceanic and Atmospheric Administration, the Government of Israel and the Hashemite Kingdom of Jordan to conduct a comprehensive research and monitoring program directed at the new Binational Red Sea Marine Pearce Park will be a pioneering effort to employ and test this new paradigm. C1 Natl Ocean & Atmospher Adm, Washington, DC 20233 USA. Marine Sci Stn, Aqaba, Jordan. Aqaba Reg Author, Aqaba, Jordan. Inter Univ Inst, Eilat, Israel. Nat & Natl Pk Protect Author, Jerusalem, Israel. RP Crosby, MP (reprint author), Natl Ocean & Atmospher Adm, Washington, DC 20233 USA. NR 35 TC 15 Z9 15 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD OCT PY 2000 VL 123 IS 1-4 BP 581 EP 594 DI 10.1023/A:1005281403279 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA 364FH UT WOS:000089881000046 ER PT J AU Ellrod, GP Nelson, JP Witiw, MR Bottos, L Roeder, WP AF Ellrod, GP Nelson, JP Witiw, MR Bottos, L Roeder, WP TI Experimental GOES Sounder products for the assessment of downburst potential SO WEATHER AND FORECASTING LA English DT Article ID MICROBURST ACTIVITY; UNITED-STATES; SOUNDINGS; DRIVEN; MODEL AB Several experimental products derived from Geostationary Operational Environmental Satellite (GOES) Sounder retrievals (vertical profiles of temperature and moisture) have been developed to assist weather forecasters in assessing the potential for convective downbursts. The product suite currently includes the wind index (WINDEX), a dry microburst index, and the maximum difference in equivalent potential temperature (theta (e)) from the surface to 300 hPa. The products are displayed as color-coded boxes or numerical values, superimposed on GOES visible, infrared, or water vapor imagery, and are available hourly, day and night, via the Internet. After two Full summers of evaluation, the products have been shown to be useful in the assessment of atmospheric conditions that may lead to strong, gusty surface winds from thunderstorms. Two case studies are presented: 1) a severe downburst storm in southern Arizona that produced historic surface wind speeds and damage, and 2) multiple dry and wet downbursts in western Kansas that resulted in minor damage. Verification involved comparing the parameters with radiosonde data, numerical model first guess data, or surface wind reports from airports, mesonetworks, or storm spotters. Mean absolute WINDEX from the GOES retrievals differed from the mean surface wind gust reports by <2 kt (1 m s(-1)) for 82 events, but underestimated wind gusts for 7 nighttime events by 22 kt (11 In s-1). GOES WINDEX was also slightly better than that derived from the concurrent National Centers for Environmental Prediction's Era Model first guess. There are plans to incorporate these downburst parameters into a future upgrade of the National Weather Service's Advanced Weather Interactive Processing System, with the option to derive them from either GOES Sounder data, radiosondes, or numerical model forecast data. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. Florida Inst Technol, Melbourne, FL 32901 USA. 45th Weather Squadron, Patrick AFB, FL USA. RP Ellrod, GP (reprint author), NOAA, WWBG, ERA2,Room 601,5200 Auth Rd, Camp Springs, MD 20748 USA. NR 42 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD OCT PY 2000 VL 15 IS 5 BP 527 EP 542 DI 10.1175/1520-0434(2000)015<0527:EGSPFT>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369FW UT WOS:000165056100003 ER PT J AU Stensrud, DJ Wandishin, MS AF Stensrud, DJ Wandishin, MS TI The correspondence ratio in forecast evaluation SO WEATHER AND FORECASTING LA English DT Article ID NATIONAL-METEOROLOGICAL-CENTER; NUMERICAL WEATHER PREDICTION; ENSEMBLE PREDICTION; PHYSICAL PARAMETERIZATIONS; SKILL SCORES; MODEL; VERIFICATION; PERFORMANCE; PRECIPITATION; CYCLOGENESIS AB The correspondence ratio is developed to evaluate output from an ensemble of numerical weather prediction models. This measure is a simple extension of the threat score, or critical success index, to more than two fields and is used to measure the divergence of the forecast fields. The ratio is compared with two commonly used measures: the anomaly correlation, and the mean square error. Results indicate that the correspondence ratio is sensitive to the bias and, when calculated for several threshold values, can provide information beyond that supplied by the mean-square error and anomaly correlation measures. The correspondence ratio is particularly useful in evaluating discontinuous Acids, such as precipitation. While no one measure can provide a complete assessment of forecast success, this ratio provides useful information that can increase our understanding of model forecast quality. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Arizona, Tucson, AZ USA. RP Stensrud, DJ (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 33 TC 20 Z9 20 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD OCT PY 2000 VL 15 IS 5 BP 593 EP 602 DI 10.1175/1520-0434(2000)015<0593:TCRIFE>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369FW UT WOS:000165056100008 ER PT J AU Zapotocny, TH Nieman, SJ Menzel, WP Nelson, JP Jung, JA Rogers, E Parrish, DF DiMego, GJ Baldwin, M Schmit, TJ AF Zapotocny, TH Nieman, SJ Menzel, WP Nelson, JP Jung, JA Rogers, E Parrish, DF DiMego, GJ Baldwin, M Schmit, TJ TI A case study of the sensitivity of the Eta Data Assimilation System SO WEATHER AND FORECASTING LA English DT Article ID WATER; MODEL; WINDS AB A ease study is utilized to determine the sensitivity of the Era Data Assimilation System (EDAS) to all operational observational data types used within it. The work described in this paper should be of interest to Eta Model users trying to identify the impact of each data type and could benefit other modelers trying to use EDAS analyses and forecasts as initial conditions for other models. The case study chosen is one characterized by strong Atlantic and Pacific maritime cyclogenesis, and is shortly after the EDAS began using three-dimensional variational analysis. The control run of the EDAS utilizes all 34 of the operational data types. One of these data types is then denied for each of the subsequent experimental runs. Differences between the experimental and control runs are analyzed to demonstrate the sensitivity of the EDAS system to each data type for the analysis and subsequent 48-h forecasts. Results show the necessity of various nonconventional observation types, such as aircraft data, satellite precipitable water, and cloud drift winds. These data types are demonstrated to have a significant impact, especially observations in maritime regions. C1 Univ Wisconsin, CIMSS, Madison, WI 53706 USA. Natl Environm Satellite Data & Informat Serv, Madison, WI USA. Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC USA. Cooperat Inst Mesoscale Meteorol Studies, Norman, OK USA. RP Menzel, WP (reprint author), Univ Wisconsin, CIMSS, 1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011; Schmit, Timothy/F-5624-2010 OI Menzel, W. Paul/0000-0001-5690-1201; NR 19 TC 31 Z9 31 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD OCT PY 2000 VL 15 IS 5 BP 603 EP 621 DI 10.1175/1520-0434(2000)015<0603:ACSOTS>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369FW UT WOS:000165056100009 ER PT J AU Jefferson, TA AF Jefferson, TA TI Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters SO WILDLIFE MONOGRAPHS LA English DT Review DE abundance; behavior; conservation status; distribution; Hong Kong; human interactions; IndoPacific hump-backed dolphin; life history; mortality; reproduction; social organization; Sousa chinensis ID BOTTLE-NOSED DOLPHINS; TURSIOPS-TRUNCATUS; MARINE MAMMALS; PERSISTENT ORGANOCHLORINES; SOUSA-CHINENSIS; SMALL CETACEANS; COASTAL WATERS; BELUGA WHALES; SOUTH-AFRICA; EAST COAST AB The Indo-Pacific hump-backed dolphin (Sousa chinensis Osbeck, 1765) is found throughout the western Pacific and Indian oceans, from southern China and northern Australia in the east to South Africa in the west. Throughout most of its range it has not been well studied, and in southern China very little is known of its biology. The goal of the present study was to provide scientific information needed for the long-term conservation and management of the population that occurs in Hong-Kong waters. From September 1997 to November 1998, 38,105 km of systematic line transect surveys were conducted throughout marine waters of the Hong Kong Special Administrative Region (SAR) of the People's Republic of China (PRC) and adjacent waters to provide data on distribution and abundance. Photo-identification of individual dolphins allowed for examination of movement patterns, home ranges, and social organization. Collection of stranded dolphin carcasses and detailed neeropsies provided information on causes of death as well as samples for life history studies, such as feeding habits, growth and reproduction, ecotoxicology, and stock structure. The dolphin population appears to be centered around the Pearl River Estuary, and Hong Kong waters represent the eastern portion of the range, which extends far into mainland Chinese waters (Lingding Bay) and covers at least 1,800 km(2). Within Hong Kong, dolphins only occur in western waters around Lantau Island. The area north of Lantau Island is heavily used throughout the year and represents by far the most important habitat in Hong Kong. Line transect analyses indicate that between 88 (spring) and 145 (summer) dolphins occur in Hong Kong. Based on 27,6000 photographs taken, 213 individual dolphins were identified. The total size of the Pearl River breeding population is unknown, but is estimated to consist of at least 1,028 dolphins, based on line transect analysis. An apparent decline in the number of dolphins in the North Lantau area over the period from 1996-1998 was not statistically significant. Individual dolphins have overlapping home ranges of about 30-400 km(2) in different sections of the population's overall range. Groups of dolphins in Hong Kong number up to 23 animals, with an average group size of 3.8 +/- s.d. 3.63 animals. There is no significant seasonal variation in group size, but groups feeding behind pair trawl fishing vessels (mean = 8.3 +/- s.d. 7.84) are significantly larger than those in Hong Kong. Groups are very fluid and change composition frequently, with association indices ranging from 0-0.333. Behavioral patterns are similar to those of other coastal dolphins, but Hong Kong hump-backed dolphins only rarely ride bow waves. Following pair trawlers represents an important feeding strategy for some individuals. Construction work on an airport fuel facility in the dolphins' main habitat appears to have caused some disturbance (indicated by increased swimming speeds) and possibly temporary evacuation of the surrounding area. There is a great deal of developmental variation in the color pattern of southern Chinese hump-backed dolphins, with a general lightening from newborn to adult stages. Males appear to retain more spots in adulthood than females. Length at birth appears to be about 100 cm, and postnatal development is characterized by rapid growth in the first year and a levelling-off of the growth curve after reaching adulthood. Asymptotic length is reached at around 243 cm. Length and weight are related exponentially, with the maximum weight about 250 kg. Calving occurs throughout the year, but most young are born from January through August, with a peak in spring/summer. Scant evidence suggests that sexual maturity in females is reached at about 9-10 years of age. Dolphins feed mainly on several demersal and pelagic fish species that are often associated with estuaries. There is a lack of evidence for long-distance movements (on the order of hundreds of linear kilometers), and this presumably results in isolation of groups around major Chinese river mouths. Thus it appears that there may be at least 8 separate populations of hump-backed dolphins along the coast of southern China. The Pearl River Estuary, including Hong Kong, is apparently inhabited by one of these populations, although preliminary genetic work has shown only equivocal evidence of population separation from dolphins in the Xiamen area. Human-related causes of mortality include entanglement in fishing nets and vessel collisions. Some environmental contaminants (especially the heavy metal mercury and the pesticide DDT) were found in high levels in some dolphins, and preliminary evidence suggests that these may be affecting the health of the animals. A series of recommendations for management and for further research have been made to aid in the conservation of these animals. Principles for the conservation of wild living resources should be followed, and information from both the natural and social sciences are needed for proper management. Research and long-term monitoring of the population must continue for management strategies to be evaluated and refined. Overall, the population of hump-backed dolphins that occurs in Hong Kong waters appears to be viable and should be able to survive with appropriate conservation efforts. C1 Ocean Pk Conservat Fdn, Aberdeen, Hong Kong, Peoples R China. RP Jefferson, TA (reprint author), NOAA, NMFS, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 141 TC 94 Z9 111 U1 5 U2 57 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0084-0173 EI 1938-5455 J9 WILDLIFE MONOGR JI Wildl. Monogr. PD OCT PY 2000 IS 144 BP 1 EP 65 PG 65 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA 369GC UT WOS:000165056700001 ER PT J AU Kareiva, P Levin, PS McClure, MM AF Kareiva, P Levin, PS McClure, MM TI Many plans, one bottom line: Save endangered salmon SO SCIENCE LA English DT Letter C1 NW Fisheries Sci Ctr, Fish Ecol Div, NMFS, Seattle, WA 98118 USA. RP Kareiva, P (reprint author), NW Fisheries Sci Ctr, Fish Ecol Div, NMFS, 2725 Montlake Blvd E, Seattle, WA 98118 USA. RI McClure, Michelle/O-7853-2015 OI McClure, Michelle/0000-0003-4791-8719 NR 0 TC 3 Z9 3 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 29 PY 2000 VL 289 IS 5488 BP 2281 EP 2281 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 359CG UT WOS:000089593500019 PM 11041793 ER PT J AU Johnson, W AF Johnson, W TI Dislocation damping after plastic deformation in interstitial-free and carbon steels SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 12th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS-12) CY JUL 19-23, 1999 CL BUENOS AIRES, ARGENTINA SP Abdus Salam Int Ctr Theoret Phys, Ctr Ind Res, Comis Nacl Actividades Espaciales, Comis Nacl Energia Atom, Consejo Nacl Invest Cientif & Tecn, Electrargen SRL, Fabr Aleaciones Especiales SA, Fdn Jose A Balseiro, Fdn Desarrikki Technol, Fdn YPF, Leybold Vacuum, Monditec, UNESCO, Vibran Technologies Inc DE steel; plastic deformation; metals; dislocation damping; point defects; internal friction; ultrasonics AB Ultrasonic resonance measurements were performed on interstitial-free and commercial carbon steels subjected to plastic deformation. Specimens had a trapped-mode cylindrical geometry which localized resonant vibrations and minimized acoustic losses into the grips of a mechanical testing machine that was attached to the ends of the specimens, Deformation induced an increase in Q(-1) and a corresponding decrease in velocity that partially recovered with time. The frequency dependence and relative magnitude of velocity changes during recovery are found to be inconsistent with a single Debye farm of the Granato-Lucke overdamped dislocation model. A distribution of Debye functions arising from a random distribution of pinning paints also fails to explain the experimental results. Published by Elsevier Science S.A. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Johnson, W (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 4 Z9 4 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 28 PY 2000 VL 310 BP 423 EP 426 DI 10.1016/S0925-8388(00)00976-2 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 357CK UT WOS:000089480800086 ER PT J AU Ogi, H Ledbetter, H Kim, S AF Ogi, H Ledbetter, H Kim, S TI Snoek relaxation in a copper-precipitated alloy steel SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 12th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS-12) CY JUL 19-23, 1999 CL BUENOS AIRES, ARGENTINA SP Abdus Salam Int Ctr Theoret Phys, Ctr Ind Res, Comis Nacl Actividades Espaciales, Comis Nacl Energia Atom, Consejo Nacl Invest Cientif & Tecn, Electrargen SRL, Fabr Aleaciones Especiales SA, Fdn Jose A Balseiro, Fdn Desarrikki Technol, Fdn YPF, Leybold Vacuum, Monditec, UNESCO, Vibran Technologies Inc DE point defects; metals; elasticity; dislocations and disclinations ID TERNARY BCC ALLOYS; DISLOCATIONS; MICROSCOPY; FE AB We studied the effect of thermal embrittlement of a steel containing 1.29 at% copper on the Suoek relaxation. The hardness increased with isothermal aging at 723 K and decreased after showing a maximum. Hardness change is governed by bcc-copper clusters precipitated from the ferrite iron crystal. Using a forced-vibration torsion-pendulum method, we studied the internal-friction spectrum and recovery of the maximum relaxation strength after quenching from 723 K. We observed a broad nonsymmetrical spectrum which apparently consists of three Debye peaks. With higher hardness, the recovery rate increased. We interpreted our results in terms Nowick's theory of interstitiaL/substitutional-solute interactions. For recovery, we used the Cottrell-Bilby-Harper of t(2/3)model. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Osaka Univ, Grad Sch Engn Sci, Toyonaka, Osaka 5608531, Japan. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Osaka Univ, Grad Sch Engn Sci, Machikaneyama 1-3, Toyonaka, Osaka 5608531, Japan. EM ogi@me.es.osaka-u.ac.jp NR 19 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 28 PY 2000 VL 310 BP 432 EP 435 DI 10.1016/S0925-8388(00)00978-6 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 357CK UT WOS:000089480800088 ER PT J AU Ogi, H Hamaguchi, T Hirao, M AF Ogi, H Hamaguchi, T Hirao, M TI In-situ monitoring of ultrasonic attenuation during rotating bending fatigue of carbon steel with electromagnetic acoustic resonance SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 12th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS-12) CY JUL 19-23, 1999 CL BUENOS AIRES, ARGENTINA SP Abdus Salam Int Ctr Theoret Phys, Ctr Ind Res, Comis Nacl Actividades Espaciales, Comis Nacl Energia Atom, Consejo Nacl Invest Cientif & Tecn, Electrargen SRL, Fabr Aleaciones Especiales SA, Fdn Jose A Balseiro, Fdn Desarrikki Technol, Fdn YPF, Leybold Vacuum, Monditec, UNESCO, Vibran Technologies Inc DE ultrasonics; dislocations and disclinations; metals; fatigue; resonance method ID EMAT AB Using electromagnetic acoustic resonance (EMAR), we studied the evolution of the surface-shear-wave attenuation and phase velocity during rotating bending fatigue of a 0.45% C steel. In the EMAR method, we used a magnetostrictively-coupled electromagnetic acoustic transducer (EMAT) for the contactless measurements of the axial shear wave that is a surface-shear wave, propagating in a cylinder-specimen circumference direction with the axial polarization. The attenuation coefficient always showed sharp peaks around 90% of the fatigue life, independent of the fatigue-stress amplitude. In addition to the ultrasonic measurements, we made crack-growth observations using replicas and measured recovery of attenuation and velocity after stopping the cyclic loading just before and after the peak. From these results, we concluded that the evolution of the ultrasonic properties is caused by a drastic change in dislocation mobility bring accompanied by the crack growth. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Osaka Univ, Grad Sch Engn Sci, Toyonaka, Osaka 5608531, Japan. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Ogi, H (reprint author), Osaka Univ, Grad Sch Engn Sci, Machikaneyama 1-3, Toyonaka, Osaka 5608531, Japan. RI 苏, 日亮/D-4386-2009 NR 10 TC 17 Z9 17 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 28 PY 2000 VL 310 BP 436 EP 439 DI 10.1016/S0925-8388(00)01020-3 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 357CK UT WOS:000089480800089 ER PT J AU Louis, F Gonzalez, CA Huie, RE Kurylo, MJ AF Louis, F Gonzalez, CA Huie, RE Kurylo, MJ TI An ab initio study of the kinetics of the reactions of halomethanes with the hydroxyl radical. 2. A comparison between theoretical and experimental values of the kinetic parameters for 12 partially halogenated methanes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; COLLINEAR REACTIONS; HYDROGEN MOLECULES; OH AB Ab initio calculations have been performed for the H-atom abstraction reactions from a series of 12 halogenated methanes by the hydroxyl radical. Geometry optimization and vibrational frequency calculations were performed for reactants, transition states, and products at the MP2/6-311G(2d,2p) level of theory. Single-point energy calculations were carried out at the PMP4(SDTQ) level with both 6-311G(3df,2p) and 6-311++G(3df,3pd) basis sets. Canonical transition state theory with Wigner's tunneling correction was used to predict the rate constants as function of the temperature (250-400 K). It is found that the treatment of the kinetics of these reactions with the lower level of theory, PMP4(SDTQ)/6-911G(3df,2p)//MP2/6-311G(2d,2p), leads to results in good agreement with experimental values and suggests the possibility of using this methodology in the implementation of a theoretical tool that properly describes the kinetics of reactions such as hydrogen abstractions by OH radicals from partially halogenated organic compounds. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Louis, F (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012; OI Louis, Florent/0000-0002-9533-557X NR 30 TC 45 Z9 45 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 28 PY 2000 VL 104 IS 38 BP 8773 EP 8778 DI 10.1021/jp001225v PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 358ME UT WOS:000089561200022 ER PT J AU Stevermer, AJ Petropavlovskikh, IV Rosen, JM DeLuisi, JJ AF Stevermer, AJ Petropavlovskikh, IV Rosen, JM DeLuisi, JJ TI Development of a global stratospheric aerosol climatology: Optical properties and applications for UV SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PINATUBO VOLCANIC AEROSOL; IN-SITU MEASUREMENTS; OZONE PROFILE DATA; SIZE DISTRIBUTION; EL-CHICHON; ATMOSPHERIC TURBIDITY; TREND ANALYSIS; SULFURIC-ACID; MT-PINATUBO; LIDAR AB A long-term stratospheric aerosol climatology is constructed using SAGE II spectral extinction measurements, worldwide lidar observations, and time series of atmospheric turbidity and transmission data. The results contain important information for assessing stratospheric aerosol effects on ultraviolet (UV) radiation and are intended to provide more accurate stratospheric aerosol corrections for the Umkehr-retrieved ozone profiles. The record, dating from 1953 to 1997, is also useful for climate studies and for estimating errors to other remote sensing methods. A significant part of this study involves examination of the relationships between aerosol size distribution and optical properties as a function of wavelength. These relationships provide empirical means for estimating aerosol extinction at various wavelengths, including UV-B wavelengths, from a single lidar backscatter value or from an extinction value at a different wavelength. A total of 134 size distributions, reported in the literature by several investigators, were used in this analysis. The results suggest the existence of a bounded and predictable domain for aerosol optical properties and indicate distinct differences between volcanic and background aerosol regimes. This paper summarizes the data and methods used in the development of a stratospheric aerosol climatology and illustrates the resulting long-term time series of monthly and zonally averaged stratospheric aerosol optical depth at 0.320 mu m. This wavelength was selected because it is close to the midpoint of the Umkehr C-pair wavelengths of 0.311 and 0.332 mu m. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Air Resources Lab, Boulder, CO 80303 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. RP RARL, 325 Broadway, Boulder, CO 80303 USA. EM amy@srrb.noaa.gov NR 66 TC 17 Z9 17 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2000 VL 105 IS D18 BP 22763 EP 22776 DI 10.1029/2000JD900368 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359EF UT WOS:000089598000008 ER PT J AU Kim, S Gopalan, V Steiner, B AF Kim, S Gopalan, V Steiner, B TI Direct x-ray synchrotron imaging of strains at 180 degrees domain walls in congruent LiNbO3 and LiTaO3 crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID FIELD; ORIGIN AB We present direct evidence for wide regions of strain on length scales of many micrometers associated with 180 degrees domain walls in congruent LiNbO3 and LiTaO3 crystals. Strain contrast in symmetric high-resolution diffraction images of these crystals in Bragg geometry arises in part from curvature in the basal planes (0001) across a domain wall as well as from lateral variation in the lattice spacing of the basal planes extending over many micrometers in going across a wall. (C) 2000 American Institute of Physics. [S0003-6951(00)02739-X]. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kim, S (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NR 16 TC 45 Z9 47 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 25 PY 2000 VL 77 IS 13 BP 2051 EP 2053 DI 10.1063/1.1312854 PG 3 WC Physics, Applied SC Physics GA 354RW UT WOS:000089344300044 ER PT J AU Kumar, RS Ijiri, S Kight, K Swanson, P Dittman, A Alok, D Zohar, Y Trant, JM AF Kumar, RS Ijiri, S Kight, K Swanson, P Dittman, A Alok, D Zohar, Y Trant, JM TI Cloning and functional expression of a thyrotropin receptor from the gonads of a vertebrate (bony fish): potential thyroid-independent role for thyrotropin in reproduction SO MOLECULAR AND CELLULAR ENDOCRINOLOGY LA English DT Article DE thyroid-stimulating hormone receptor; fish; ovary; testis ID LUTEINIZING-HORMONE RECEPTOR; FOLLICLE-STIMULATING-HORMONE; SALMON ONCORHYNCHUS-RHODURUS; CHORIONIC-GONADOTROPIN; MOLECULAR-CLONING; CHORIOGONADOTROPIN RECEPTOR; CDNA; CELLS; OVARY; LH AB The thyroid stimulating hormone receptor (TSHR) mediates the pituitary control of the development, growth and function of the thyroid. The expression of the gene encoding this receptor is known only in the thyroid, lymphocytes, fibroblasts, retro-orbital tissue and fat cells. We have cloned a TSHR from the gonads of a non-mammalian vertebrate, a bony fish (striped bass, Mol one saxatilis) in the course of our search for gonadotropin receptors (follicle stimulating hormone receptor, FSHR and luteinizing hormone receptor, LHR). RT-PCR analysis demonstrated that the striped bass TSHR (stbTSHR) transcripts were abundant in both the thyroid and gonads and detectable in skeletal muscle, heart and brain tissues. The stbTSHR cDNA encoded a 779-amino acid glycoprotein hormone receptor with much higher homology (57-59%) to the mammalian TSH receptors than the mammalian LH receptors (47-49%) and FSH receptors (47%), and salmon and catfish gonadotropin receptors (42-45%). There was a TSHR-specific insertion in the extracellular domain as seen in mammalian receptors. Moreover, PCR analysis of genomic DNA indicated the absence of the LHR-specific intron in the striped bass TSHR gene. Recombinant stbTSHR expressed in COS1 cells activated reporter genes (luciferase) driven by either a cAMP response element or the c-fos promoter in response to bovine TSH, stbLH or hCG, but not human FSH. In situ hybridization studies revealed the presence of stbTSHR transcripts in the gametes but not in the follicular cells. This pattern of expression is unique and suggests a direct, albeit unknown, role for TSH in gamete physiology. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved. C1 Univ Maryland, Inst Biotechnol, Ctr Marine Biotechnol, Baltimore, MD 21202 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Trant, JM (reprint author), Univ Maryland, Inst Biotechnol, Ctr Marine Biotechnol, 701 E Pratt St, Baltimore, MD 21202 USA. RI Ijiri, Shigeho/C-4726-2013 NR 32 TC 50 Z9 54 U1 0 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0303-7207 J9 MOL CELL ENDOCRINOL JI Mol. Cell. Endocrinol. PD SEP 25 PY 2000 VL 167 IS 1-2 BP 1 EP 9 DI 10.1016/S0303-7207(00)00304-X PG 9 WC Cell Biology; Endocrinology & Metabolism SC Cell Biology; Endocrinology & Metabolism GA 358RU UT WOS:000089571600001 PM 11000515 ER PT J AU Leo, PJ Williams, CJ Julienne, PS AF Leo, PJ Williams, CJ Julienne, PS TI Collision properties of ultracold Cs-133 atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALKALI-METAL ATOMS; FREQUENCY STANDARD; CESIUM FOUNTAIN; ENERGY; POTENTIALS; RELAXATION; SHIFT; CS-2 AB We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Chin ct al. [preceding Letter, Phys. Rev. Lett. 85, 2717 (2000)] at fields of up to 25 mT. This analysis provides the most accurate characterization of the collisional properties of ground state Cs atoms currently available and clearly shows, in contrast to previous work, that Bose-Einstein condensation of Cs-133 cannot be ruled out. The X(1)Sigma(g)(+) and a(3)Sigma(u), scattering lengths are constrained to (280 +/- 10)a(0) and (2400 +/- 100)a(0), respectively (1a(0) = 0.0529177 nm), and the van der Waals Cg coefficient to 6890 +/- 35 a.u. (1 a.u. = 0.0957345 x 10(-24) J . nm(6)). C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Leo, PJ (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Williams, Carl/B-5877-2009; Leo, Paul/B-3470-2011; Julienne, Paul/E-9378-2012 OI Leo, Paul/0000-0001-8325-4134; Julienne, Paul/0000-0002-5494-1442 NR 22 TC 117 Z9 117 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 25 PY 2000 VL 85 IS 13 BP 2721 EP 2724 DI 10.1103/PhysRevLett.85.2721 PG 4 WC Physics, Multidisciplinary SC Physics GA 356WD UT WOS:000089465100017 ER PT J AU Eremets, MI Gregoryanz, EA Struzhkin, VV Mao, HK Hemley, RJ Mulders, N Zimmerman, NM AF Eremets, MI Gregoryanz, EA Struzhkin, VV Mao, HK Hemley, RJ Mulders, N Zimmerman, NM TI Electrical conductivity of xenon at megabar pressures SO PHYSICAL REVIEW LETTERS LA English DT Article ID INSULATOR-METAL TRANSITION; SOLID XENON; OPTICAL-ABSORPTION; X-RAY; METALLIZATION AB The electrical transport properties of solid xenon were directly measured at pressures up to 155 GPa and temperatures from 300 K to 27 mK. The temperature dependence of resistance changed from semiconducting to metallic at pressures between 121 and 138 GPa, revealing direct proof of metallization of a rare-gas solid by electrical transport measurements. Anomalies in the conductivity are observed at low temperatures in the vicinity of the transition such that purely metallic behavior is observed only at 155 GPa over the entire temperature range. C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Carnegie Inst Washington, Ctr High Pressure Res, Washington, DC 20015 USA. Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Eremets, MI (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. RI Struzhkin, Viktor/J-9847-2013 OI Struzhkin, Viktor/0000-0002-3468-0548 NR 23 TC 70 Z9 70 U1 2 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 25 PY 2000 VL 85 IS 13 BP 2797 EP 2800 DI 10.1103/PhysRevLett.85.2797 PG 4 WC Physics, Multidisciplinary SC Physics GA 356WD UT WOS:000089465100036 ER PT J AU Changnon, SA Easterling, DR AF Changnon, SA Easterling, DR TI Disaster management - US policies pertaining to weather and climate extremes SO SCIENCE LA English DT Article ID UNITED-STATES; IMPACTS C1 NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. Univ Illinois, Dept Geog, Champaign, IL 61820 USA. RP NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. EM deasterl@ncdc.noaa.gov NR 21 TC 13 Z9 14 U1 2 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD SEP 22 PY 2000 VL 289 IS 5487 BP 2053 EP 2055 DI 10.1126/science.289.5487.2053 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 356EG UT WOS:000089430900024 PM 11032554 ER PT J AU Easterling, DR Meehl, GA Parmesan, C Changnon, SA Karl, TR Mearns, LO AF Easterling, DR Meehl, GA Parmesan, C Changnon, SA Karl, TR Mearns, LO TI Climate extremes: Observations, modeling, and impacts SO SCIENCE LA English DT Review ID TROPICAL CYCLONE ACTIVITY; LONG-TERM TRENDS; UNITED-STATES; EUPHYDRYAS-EDITHA; BUTTERFLY METAPOPULATION; ENVIRONMENTAL VARIATION; PRECIPITATION EVENTS; POPULATION-DYNAMICS; ATLANTIC HURRICANES; AUSTRALIAN REGION AB One of the major concerns with a potential change in climate is that an increase in extreme events will occur. Results of observational studies suggest that in many areas That have been analyzed, changes in total precipitation are amplified at the tails, and changes in some temperature extremes have been observed. Model output has been analyzed that shows changes in extreme events for future climates, such as increases in extreme high temperatures. decreases in extreme Low temperatures, and increases in intense precipitation events. In addition, the societal infrastructure is becoming more sensitive to weather and climate extremes, which would be exacerbated by climate change. In wild plants and animals, climate-induced extinctions, distributional and phenological changes, and species' range shifts are being documented at an increasing rate. Several apparently gradual biological changes are Linked to responses to extreme weather and climate events. C1 NOAA, Natl Climate Data Ctr, Asheville, NC 28801 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. Univ Texas, Austin, TX 78712 USA. Illinois State Water Survey, Champaign, IL 61820 USA. RP Easterling, DR (reprint author), NOAA, Natl Climate Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. EM david.r.easterling@noaa.gov NR 130 TC 1823 Z9 1929 U1 128 U2 1007 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD SEP 22 PY 2000 VL 289 IS 5487 BP 2068 EP 2074 DI 10.1126/science.289.5487.2068 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 356EG UT WOS:000089430900033 PM 11000103 ER PT J AU Silver, E Schnopper, H Bandler, S Brickhouse, N Murray, S Barbera, M Takacs, E Gillaspy, JD Porto, JV Kink, I Laming, JM Madden, N Landis, D Beeman, J Haller, EE AF Silver, E Schnopper, H Bandler, S Brickhouse, N Murray, S Barbera, M Takacs, E Gillaspy, JD Porto, JV Kink, I Laming, JM Madden, N Landis, D Beeman, J Haller, EE TI Laboratory astrophysics survey of key X-ray diagnostic lines using a microcalorimeter on an electron beam ion trap SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; line : identification; methods : laboratory; plasmas; X-rays : general ID POLARIZATION; EMISSION AB Cosmic plasma conditions created in an electron beam ion trap (EBIT) make it possible to simulate the dependencies of key diagnostic X-ray lines on density, temperature, and excitation conditions that exist in astrophysical sources. We used a microcalorimeter for such laboratory astrophysics studies because it has a resolving power approximate to 1000, quantum efficiency approaching 100%, and a bandwidth that spans the X-ray energies from 0.2 keV to 10 keV. Our microcalorimeter, coupled with an X-ray optic to increase the effective solid angle, provides a significant new capability for laboratory astrophysics measurements. Broadband spectra obtained from the National Institute of Standards and Technology EBIT with an energy resolution approaching that of a Bragg crystal spectrometer are presented for nitrogen, oxygen, neon, argon, and krypton in various stages of ionization. We have compared the measured line intensities to theoretical predictions for an EBIT plasma. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osserv Astron GS Vaiana, I-90134 Palermo, Italy. MIT, Cambridge, MA 02139 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. RP Silver, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Bandler, Simon/A-6258-2010; OI Bandler, Simon/0000-0002-5112-8106; Brickhouse, Nancy/0000-0002-8704-4473; Barbera, Marco/0000-0002-3188-7420 NR 18 TC 36 Z9 37 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 495 EP 500 DI 10.1086/309420 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300049 ER PT J AU Rafac, RJ Young, BC Beall, JA Itano, WM Wineland, DJ Bergquist, JC AF Rafac, RJ Young, BC Beall, JA Itano, WM Wineland, DJ Bergquist, JC TI Sub-dekalhertz ultraviolet spectroscopy of Hg-199(+) SO PHYSICAL REVIEW LETTERS LA English DT Article ID FREQUENCY STANDARD; OPTICAL FREQUENCY; ION; STABILIZATION; OSCILLATOR; LASERS; LEVEL; TRAP AB Using a laser that is frequency locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d(10)6s S-2(1/2)(F = 0) <----> 5d(9)6s(2) D-2(5/2)(F = 2) Delta m(F) = 0 electric-quadrupole transition of a single laser-cooled Hg-199(+) ion stored in a cryogenic radio-frequency ion trap. We observe Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 x 10(15) Hz), yielding a line Q approximate to 1.6 x 10(14). We perform a preliminary measurement of the 5d(9)6s(2) D-2(5/2) electric-quadrupole shift due to interaction with the static fields of the trap, and discuss the implications for future trapped-ion optical frequency standards. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 27 TC 206 Z9 216 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 18 PY 2000 VL 85 IS 12 BP 2462 EP 2465 DI 10.1103/PhysRevLett.85.2462 PG 4 WC Physics, Multidisciplinary SC Physics GA 355NV UT WOS:000089392500013 ER PT J AU Kriesel, JM Driscoll, CF AF Kriesel, JM Driscoll, CF TI Two regimes of asymmetry-induced transport in non-neutral plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID PURE ELECTRON-PLASMA; NONNEUTRAL PLASMA; PENNING TRAP; CONFINEMENT; TIME; ANTIHYDROGEN AB Confinement of charged particles in cylindrical Penning-Malmberg traps depends strongly on cross-magnetic-field transport induced by electric and/or magnetic asymmetries. New measurements in pure-electron plasmas demonstrate two separate transport regimes depending on the particle bounce-to-rotation ratio, or rigidity, R = (f) over bar(b)/f(E). For R < 10, the transport scales as VaR-2, where V-a is the strength of an applied electrostatic asymmetry. For R greater than or similar to 10-20, this "R-2 transport" ceases abruptly, leaving "B-independent" transport which scales as V-a(2) and does not depend directly on the rigidity. C1 Univ Calif San Diego, Dept Phys, San Diego, CA 92093 USA. RP Kriesel, JM (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 34 TC 46 Z9 46 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 SEP 18 PY 2000 VL 85 IS 12 BP 2510 EP 2513 DI 10.1103/PhysRevLett.85.2510 PG 4 WC Physics, Multidisciplinary SC Physics GA 355NV UT WOS:000089392500025 ER PT J AU Kuck, LR Smith, T Balsley, BB Helmig, D Conway, TJ Tans, PP Davis, K Jensen, ML Bognar, JA Arrieta, RV Rodriquez, R Birks, JW AF Kuck, LR Smith, T Balsley, BB Helmig, D Conway, TJ Tans, PP Davis, K Jensen, ML Bognar, JA Arrieta, RV Rodriquez, R Birks, JW TI Measurements of landscape-scale fluxes of carbon dioxide in the Peruvian Amazon by vertical profiling through the atmospheric boundary layer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID REGIONAL SURFACE FLUXES; RAIN-FOREST; CO2; BUDGET; KITES; CYCLE AB Vertical profiles of carbon dioxide were measured within and above the atmospheric boundary layer at a tropical forest site in the Peruvian Amazon during July 1996 using a tethered balloon sampling platform. Flask samples were collected within and above the mixed layer and analyzed off-site for carbon dioxide by nondispersive infrared spectrophotometry. Ozone and temperature vertical profiles were used to determine the boundary layer heights and growth rates. The mean values for methane, carbon monoxide, hydrogen, carbon-13, and oxygen-18 ratios were determined within and above the mixed layer. Daytime carbon dioxide flux values were calculated using the budget method. Nocturnal fluxes were estimated by integrating the carbon dioxide mixing ratios as a function of height from the ground to the inversion layer and dividing the total accumulated carbon dioxide by the time since sunset. The daytime carbon dioxide flux of -13 +/- 2 mu mol C m(-2) s(-1) and the nocturnal flux of +5.0 +/- 1.0 mu mol C m(-2) s(-1) are in good agreement with previous studies in the Brazilian Amazon. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Minnesota, Dept Soil Water & Climate, St Paul, MN 55108 USA. Univ Piura, Fac Ingn, Piura, Peru. RP Kuck, LR (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 35 TC 20 Z9 21 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22137 EP 22146 DI 10.1029/2000JD900105 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100002 ER PT J AU Weatherhead, EC Reinsel, GC Tiao, GC Jackman, CH Bishop, L Frith, SMH DeLuisi, J Keller, T Oltmans, SJ Fleming, EL Wuebbles, DJ Kerr, JB Miller, AJ Herman, J McPeters, R Nagatani, RM Frederick, JE AF Weatherhead, EC Reinsel, GC Tiao, GC Jackman, CH Bishop, L Frith, SMH DeLuisi, J Keller, T Oltmans, SJ Fleming, EL Wuebbles, DJ Kerr, JB Miller, AJ Herman, J McPeters, R Nagatani, RM Frederick, JE TI Detecting the recovery of total column ozone SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC OZONE; ANTARCTIC OZONE; TRENDS; TEMPERATURE; NIMBUS-7; LATITUDE; UMKEHR; HOLE AB International agreements for the limitation of ozone-depleting substances have already resulted in decreases in concentrations of some of these chemicals in the troposphere. Full compliance and understanding of all factors contributing to ozone depletion are still uncertain; however, reasonable expectations are for a gradual recovery of the ozone layer over the next 50 years. Because of the complexity of the processes involved in ozone depletion, it is crucial to detect not just a decrease in ozone-depleting substances but also a recovery in the ozone layer. The recovery is likely to be detected in some areas sooner than others because of natural variability in ozone concentrations. On the basis of both the magnitude and autocorrelation of the noise from Nimbus 7 Total Ozone Mapping Spectrometer ozone measurements, estimates of the time required to detect a fixed trend in ozone at various locations around the world are presented. Predictions from the Goddard Space Flight Center (GSFC) two-dimensional chemical model are used to estimate the time required to detect predicted trends in different areas of the world. The analysis is based on our current understanding of ozone chemistry, full compliance with the Montreal Protocol and its amendments, and no intervening factors, such as major volcanic eruptions or enhanced stratospheric cooling. The results indicate that recovery of total column ozone is likely to be detected earliest in the Southern Hemisphere near New Zealand, southern Africa, and southern South America and that the range of time expected to detect recovery for most regions of the world is between 15 and 45 years. Should the recovery be slower than predicted by the GSFC model, owing, for instance, to the effect of greenhouse gas emissions, or should measurement sites be perturbed, even longer times would be needed for detection. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. Univ Chicago, Grad Sch Business, Chicago, IL 60637 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Allied Signal Corp, Buffalo, NY 14210 USA. Steven Myers & Assoc Corp, Arlington, VA 22201 USA. NOAA, Air Resources Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Illinois, Dept Atmospher Sci, Champaign, IL 61801 USA. Atmospher Environm Serv, Downsview, ON M3H 5T4, Canada. Natl Weather Serv, Washington, DC 20233 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Weatherhead, EC (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RI Jackman, Charles/D-4699-2012; McPeters, Richard/G-4955-2013; Weatherhead, Elizabeth/I-7091-2015; OI McPeters, Richard/0000-0002-8926-8462; Weatherhead, Elizabeth/0000-0002-9252-4228; Herman, Jay/0000-0002-9146-1632 NR 27 TC 76 Z9 85 U1 2 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22201 EP 22210 DI 10.1029/2000JD900063 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100006 ER PT J AU Mate, B Lugez, CL Solodov, AM Fraser, GT Lafferty, WJ AF Mate, B Lugez, CL Solodov, AM Fraser, GT Lafferty, WJ TI Investigation of the collision-induced absorption by O-2 near 6.4 mu m in pure O-2 and O-2/N-2 mixtures SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; OXYGEN; CONTINUUM; SPECTRUM; SOUNDER; BAND AB The collision-induced fundamental vibrational band of molecular oxygen has been measured between 1300 and 2000 cm(-1) using a Fourier-transform infrared spectrometer and an optical path length of 84 m. Spectra were recorded for pure O-2 and O-2/N-2 mixtures at densities up to 10 times the density of an ideal gas at standard temperature (273.15 K) and pressure (101.325 kPa), and for temperatures between 228 and 296 K. The band is dominated by the Delta J = 0, Q branch and the Delta J = 2, S and Delta J = -2, O branch shoulders, with the S branch exhibiting ripples previously attributed to bound dimer transitions, pure quadrupole transitions of O-2 perturbed by line mixing, and intercollisional interferences. The ripples are seen at the same wavenumbers in O-2-Ar mixtures, with intensities dependent on both the O-2 and Ar densities, suggesting that the ripples are not due to bound dimer transitions. The integrated band intensity S is related to the collision-induced absorption coefficients by S = S(O2-O2)rho(O2)(2) + SO2-N2 rho(O2)rho(N2), where SO2-O2 and SO2-N2 are the integrated binary collision-induced absorption coefficients for O-2-O-2 and O-2-N-2 collisions, respectively, and rho(O2) and rho(N2) are the O-2 and N-2 gas densities. We find values for SO2-O2 = 6.972(66) X 10(-4) cm(-2) and SO2-N2 = 7.12(22) X 10(-4) cm(-2) respectively, at 296 K,when the gas density is equal to that found at STP (i.e., SO2-O2 6.972(66) X 10(-4) cm(-2) amagat(-2) and SO2-N2 = 7.12(22) X 10(-4) cm(-2) amagat(-2)). C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Mate, B (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. EM gerald.fraser@nist.gov RI Mate, Belen/F-1135-2016 OI Mate, Belen/0000-0002-5478-8644 NR 23 TC 11 Z9 11 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22225 EP 22230 DI 10.1029/2000JD900295 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100008 ER PT J AU Baumgardner, D Raga, GB Kok, G Ogren, J Rosas, I Baez, A Novakov, T AF Baumgardner, D Raga, GB Kok, G Ogren, J Rosas, I Baez, A Novakov, T TI On the evolution of aerosol properties at a mountain site above Mexico City SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIR-POLLUTION; MORTALITY; PARTICLES AB Size distributions, scattering and absorption coefficients, and the bulk chemical composition of aerosols have been measured at a mountain site 400 m above the southwest sector of the Mexico City basin during a two-week period in November 1997. Variations in these properties are primarily related to local meteorology, i.e., wind direction and relative humidity; however, a link was found between carbon monoxide and ozone and the partitioning of aerosols between Aitken and accumulation mode sizes. Relative humidity was also found to affect this partitioning of aerosol size and volume. In addition, the fraction of sulfate in the aerosols was much higher on a high-humidity day than on a very low humidity day; however, the fraction of the mass contained in organic and elemental carbon was the same regardless of humidity levels. The daily variations of aerosol properties are associated with the arrival of new particles at the research site transported from the city basin and their subsequent mixture with aged aerosols that remain in the residual layer from the night before. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Calif Berkeley, Berkeley Natl Lab, Berkeley, CA 94720 USA. NOAA, CMDL, Boulder, CO 80303 USA. RP Baumgardner, D (reprint author), Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Circuito Exteriro,Ciudad Univ, Mexico City 04510, DF, Mexico. EM darrel@servidor.unam.mx; raga@servidor.unam.mx; kok@ucar.edu; jogren@cmdl.noaa.gov; tnovakov@lbl.gov RI Raga, Graciela/A-4340-2008; Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 25 TC 34 Z9 34 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22243 EP 22253 DI 10.1029/2000JD900299 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100010 ER PT J AU Khain, A Ginis, I Falkovich, A Frumin, M AF Khain, A Ginis, I Falkovich, A Frumin, M TI Interaction of binary tropical cyclones in a coupled tropical cyclone-ocean model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SCALE VORTICES; NUMERICAL-SIMULATION; MOTION; LAYER AB The motion and evolution of binary tropical cyclones was investigated using a coupled tropical cyclone-ocean movable nested grid model. The model consists of eight-layer atmospheric and seven-layer ocean primitive equation models. Several regimes of binary storm interaction have been identified, depending on the initial separation distance (d) and differences in storm strengths. At d less than a few hundred kilometers, interacting storms experienced complete merger (CM) or partial merger (PM). At larger d (between about 600 km and 1000 km), three regimes of storm interaction have been found: PM, straining out (SO), characterized by complete disintegration of the weaker storm, and mutual straining out (MSO), characterized by weakening and dissipation of both storms. SO occurred when the interacting storms had substantially different intensities and strengths. MSO was observed when the interacting storms were comparable in size and intensity. In the latter case the storms were unable to approach each other at distances smaller than a certain minimum distance (of about 450-500 km) without being mutually stretched out. Moreover, initial attraction of the storms in this regime was replaced by repulsion, as frequently observed in the western Pacific. At d exceeding about 1000 km, elastic interaction CEI) was found, when the storms interact without any significant changes in their intensity and structure. In additional experiments with a conditional instability of the second kind (CISK) type parameterization of convective heating the storm interaction was very different: The storms were nearly axisymmetric and very compact, and they continued approaching each other until they merged Thus more realistic simulations of binary storm interaction can be achieved by using a physically more reasonable convective parameterization. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC 20203 USA. Hebrew Univ Jerusalem, Inst Earth Sci, Dept Atmospher Sci, IL-91904 Jerusalem, Israel. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. RP Khain, A (reprint author), Natl Ctr Environm Predict, Environm Modeling Ctr, World Weather Bldg,5200 Auth Rd,Room 7241, Washington, DC 20203 USA. EM khain@vms.huji.ac.il NR 35 TC 5 Z9 5 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 SEP 16 PY 2000 VL 105 IS D17 BP 22337 EP 22354 DI 10.1029/2000JD900268 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100015 ER PT J AU Mazur, V Ruhnke, LH Bondiou-Clergerie, A Lalande, P AF Mazur, V Ruhnke, LH Bondiou-Clergerie, A Lalande, P TI Computer simulation of a downward negative stepped leader and its interaction with a ground structure SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MODEL AB A scheme for computer simulation of a negative stepped leader is developed, based on a physical description of the processes occurring during step development. The scheme is applied to a three-dimensional model of the interaction between a downward negative leader and a grounded mast under two assumptions, one with and one without an upward positive leader initiated from the tip of the mast. The modeling is performed for 2-m and 10-m-diameter leaders under a -10-MV and -40-MV electrical potential, respectively. The downward leader reacts to the mast only at the final jump-over, irrespective of the emission of the positive leader from the mast, thus suggesting the critical role of the final jump. The dominant factor in the interaction of the negative leader with a grounded mast of fixed height is shown to be the leader's potential, which determines the length of the leader step and, thus, the length of the final jump to the ground structure. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Off Natl Etud & Rech Aerosp, F-92322 Chatillon, France. RP Mazur, V (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM mazur@nssl.noaa.gov NR 16 TC 20 Z9 25 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22361 EP 22369 DI 10.1029/2000JD900278 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100017 ER PT J AU Matrosov, SY Heymsfield, AJ AF Matrosov, SY Heymsfield, AJ TI Use of Doppler radar to assess ice cloud particle fall velocity-size relations for remote sensing and climate studies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TERMINAL VELOCITIES; CIRRUS CLOUDS; PARAMETERS; RETRIEVALS; RADIATION AB Knowledge of ice crystal terminal velocities, both for individual crystals and for size distributions, is important for an adequate representation of ice particle sedimentation in climate models. While the terminal velocities (nu(t)) of individual crystals of simple shapes have been measured, theoretical relations of the form nu(t) = AD(B) (where D is the maximum particle dimension), obtained using expressions for the aerodynamic drag force, are often more useful because they can be applied to a wide range of particle sizes and heights and temperatures in the atmosphere. For high tropospheric ice clouds the coefficient A has been found to vary over 1 order of magnitude; the exponent B is generally within the range 0.7-1.4. Aerodynamic drag force calculations show that A and B are related. A and B can also be used to characterize terminal-velocity-particle characteristic size relations for size distributions. In this study we use collocated, vertically pointing measurements of ice cloud radar reflectivity, Doppler velocity, and IR brightness temperatures to estimate the vertical profiles of cloud particle characteristic size, cloud ice water content, and vertically averaged value of the coefficient A, emphasizing cirrus clouds. We analyze variations in terminal-velocity-size relations for individual particles and corresponding variations for ensembles of particles: for example, in relations between the reflectivity-weighted terminal velocity and the median volume size and between the mass-weighted terminal velocity and the median volume size. The retrievals indicate that A ranges from similar to 250 to almost 4000 legs units), similar to the range found from the theoretical calculations. The coefficient A tends to decrease as a characteristic particle size (e.g., median size) increases. As a simplification for climate modeling efforts, we present an empirical relation between median size and A, although there is a fair amount of variability about this relation. Using the Doppler measurements and retrieval data, we also derive relations between the mass-weighted terminal velocity and cloud ice water content. Such relations are useful for representing fallout of ice particles in climate and cloud-resolving models. C1 Natl Ctr Atmospher Res, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Matrosov, SY (reprint author), R-E-ET6,325 Broadway, Boulder, CO 80303 USA. EM smatrosov@etl.noaa.gov RI Heymsfield, Andrew/E-7340-2011 NR 22 TC 22 Z9 22 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2000 VL 105 IS D17 BP 22427 EP 22436 DI 10.1029/2000JD900353 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356XH UT WOS:000089469100021 ER PT J AU Allison, TC Friedman, RS Kaufman, DJ Truhlar, DG AF Allison, TC Friedman, RS Kaufman, DJ Truhlar, DG TI Analysis of the resonance in H+D-2 -> HD (nu '=3)+D SO CHEMICAL PHYSICS LETTERS LA English DT Article ID QUANTIZED TRANSITION-STATES; REACTION-PATH; CHEMICAL-REACTIONS; REACTION-RATES; H-3; THRESHOLDS; COLLISIONS; SCATTERING; DYNAMICS; ENERGIES AB The resonance recently observed by Fernandez-Alonso et al. at a total energy of 1.83 eV for H + D-2 (upsilon = j = 0) --> HD(upsilon' = 3,j' = 0)+ D is analyzed in terms of a locally vibrationally adiabatic model. The resonance is assigned as a upsilon(1) = 3, upsilon(2) = 0 vibrational state of a D-DH complex with total angular momentum quantum numbers of about 20, and it is associated with a vibrationally adiabatic barrier at a D-D distance of 2.9 to 3.1 a(0). The assignment explains the preferential decay into the upsilon' = 3, j' = 0 state of HD. (C) 2000 Published by Elsevier Science B.V. C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Minnesota, Inst Supercomp, Minneapolis, MN 55455 USA. NIST, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. Indiana Univ Purdue Univ, Dept Chem, Ft Wayne, IN 46805 USA. RP Truhlar, DG (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. RI Truhlar, Donald/G-7076-2015 OI Truhlar, Donald/0000-0002-7742-7294 NR 37 TC 26 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 15 PY 2000 VL 327 IS 5-6 BP 439 EP 445 DI 10.1016/S0009-2614(00)00885-X PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 353XZ UT WOS:000089301900026 ER PT J AU Tsunoda, PT Ecklund, WL Johnston, PE AF Tsunoda, PT Ecklund, WL Johnston, PE TI Radar measurements of electric fields in the topside of the equatorial electrojet: First results SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We show that the vertical polarization electric field (E-p) in the topside of the equatorial electrojet can be determined from the Doppler spectra of type-2 echoes obtained with a radar that is appropriately displaced in latitude from the magnetic dip equator. Using a 49.92 MHz radar on Christmas Island (2.9 degrees magnetic dip latitude), we found unexpectedly large E-p at altitudes at least as high as 120 km over the dip equator. Another new and related finding is the transient appearance of type-1 echoes at 99 km over Christmas Island, which likely was produced by an E-p of at least 11 mV/m that must have appeared at 114 km altitude over the dip equator. Elevated electron temperatures inferred from the type-1 Doppler spectra are consistent with the presence of anomalous energetics. C1 SRI Int, Menlo Park, CA 94025 USA. NOAA, CIRES, Boulder, CO USA. RP Tsunoda, PT (reprint author), SRI Int, 333 Ravenswood Ave, Menlo Park, CA 94025 USA. RI Johnston, Paul/E-1914-2016 OI Johnston, Paul/0000-0002-4046-9351 NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2000 VL 27 IS 18 BP 2861 EP 2864 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 355MX UT WOS:000089390400010 ER PT J AU Fitzenberger, R Bosch, H Camy-Peyret, C Chipperfield, MP Harder, H Platt, U Sinnhuber, BM Wagner, T Pfeilsticker, K AF Fitzenberger, R Bosch, H Camy-Peyret, C Chipperfield, MP Harder, H Platt, U Sinnhuber, BM Wagner, T Pfeilsticker, K TI First profile measurements of tropospheric BrO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DIFFERENT LATITUDES; BROMINE CHEMISTRY; BOUNDARY-LAYER; POLAR SUNRISE; AEROSOLS; SEASONS; OXIDE; DOAS; HBR AB Tropospheric BrO profiles (about 0.6+/-0.2 ppt, and 2.0+/-0.8 ppt at profile maximum) were measured for the first time. Our measurements add new information to recent speculations - based on indirect evidence - of BrO possibly being ubiquitous in the free troposphere [Harder. et al., 1998; Friess et al., 1999; Van Roozendael et al., 1999; Pundt et al., 2000]. Our study relies on a detailed comparison of BrO slant column densities (BrO-SCD) measured in the troposphere from the LPMA/DOAS (Laboratoire de Physique Moleculaire et Applications and Differential Optical Absorption Spectroscopy) gondola by direct Sun absorption, and BrO-SCD values subsequently measured in the lowermost stratosphere during balloon ascent. The difference in total atmospheric BrO-SCDs measured in the troposphere and lowermost stratosphere - after a suitable correction for the change in BrO due to photochemistry and the observation geometry - is then attributed to tropospheric BrO. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. Univ Paris 06, CNRS, LPMA, Paris, France. Univ Leeds, Sch Environm, Leeds, W Yorkshire, England. Max Planck Inst Chem, Mainz, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Fitzenberger, R (reprint author), Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany. RI Sinnhuber, Bjorn-Martin/A-7007-2013; Chipperfield, Martyn/H-6359-2013; Harder, Hartwig/L-2511-2014; Boesch, Hartmut/G-6021-2012 OI Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Chipperfield, Martyn/0000-0002-6803-4149; Harder, Hartwig/0000-0002-6868-714X; NR 22 TC 71 Z9 72 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2000 VL 27 IS 18 BP 2921 EP 2924 DI 10.1029/2000GL011531 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 355MX UT WOS:000089390400025 ER PT J AU McMichael, RD Lee, CG Bonevich, JE Chen, PJ Miller, W Egelhoff, WF AF McMichael, RD Lee, CG Bonevich, JE Chen, PJ Miller, W Egelhoff, WF TI Strong anisotropy in thin magnetic films deposited on obliquely sputtered Ta underlayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GROWTH AB Anisotropy fields in excess of 120 kA/m (1500 Oe) have been produced in 3-5-nm-thick polycrystalline films of Co by oblique sputtering of Ta underlayers. The unusually high anisotropy is magnetostatic in origin and is induced by corrugations on the surface of an obliquely sputtered Ta underlayer. Cross-sectional transmission electron microscopy reveals 4 nm columnar grains of Ta tilted toward the Ta source and elongated perpendicular to the Ta flux in the film plane. The anisotropy field of the Co film increases with both the underlayer thickness and the angle between the Ta source and the film normal. In spin valve samples, the anisotropy is attenuated by more than an order of magnitude across a 4-nm-thick Cu spacer. Magnetoresistance measurements on a spin valve indicate less than 2 degrees dispersion in hard axis directions, and despite the nanometer-scale roughness of the underlayer there is weak broadening of the ferromagnetic resonance line. (C) 2000 American Institute of Physics. [S0021-8979(00)05019-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Changwon Natl Univ, Dept Met & Mat Engn, Changwon 641773, Kyungnam, South Korea. RP McMichael, RD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. OI McMichael, Robert/0000-0002-1372-664X NR 16 TC 32 Z9 33 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2000 VL 88 IS 6 BP 3561 EP 3564 DI 10.1063/1.1289517 PG 4 WC Physics, Applied SC Physics GA 349GB UT WOS:000089034700063 ER PT J AU Reid, JP Marcy, TP Kuehn, S Leone, SR AF Reid, JP Marcy, TP Kuehn, S Leone, SR TI The direct production of CO(v=1-9) in the reaction of O(P-3) with the ethyl radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSFORM INFRARED-EMISSION; RESOLVED FTIR EMISSION; LASER FLASH-PHOTOLYSIS; CH3 RADICALS; TIME; KINETICS; ATOMS; DYNAMICS; CO; ACETONE AB A new product channel that yields vibrationally excited CO(v=1-9) in the reaction of the ethyl radical with O(P-3) is experimentally observed by time-resolved Fourier transform infrared emission spectroscopy. The branching ratios for the different vibrational states are estimated to be 0.21 +/- 0.06, 0.27 +/- 0.03, 0.14 +/- 0.02, 0.08 +/- 0.02, 0.07 +/- 0.02, 0.07 +/- 0.02, 0.06 +/- 0.02, 0.05 +/- 0.02, and 0.05 +/- 0.02 for v=1-9, respectively. Previously, only the CH3+H2CO, CH3CHO+H, and C2H4+OH channels were known. Kinetics tests are provided to verify that the CO is produced directly in the reaction and not from secondary chemistry. The two possible new product channels are CO+CH4+H and CO+CH3+H-2. The implications of this previously unexplored reaction channel for combustion chemistry and the possible mechanisms for this reaction are discussed. (C) 2000 American Institute of Physics. [S0021-9606(00)00935-1]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Reid, JP (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Reid, Jonathan/D-9411-2013 NR 41 TC 22 Z9 23 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 2000 VL 113 IS 11 BP 4572 EP 4580 DI 10.1063/1.1288791 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 351DC UT WOS:000089139900011 ER PT J AU Huang, HP Sardeshmukh, PD AF Huang, HP Sardeshmukh, PD TI Another look at the annual and semiannual cycles of atmospheric angular momentum SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO; SOUTHERN OSCILLATION; ROTATIONAL FLOW; CHI-PROBLEM; LENGTH; FLUCTUATIONS; CIRCULATION; TROPICS; MODEL; HEMISPHERE AB The annual variation of global atmospheric angular momentum (AAM) is dominated by its first and second harmonic components. The first, harmonic is associated with maximum global AAM in winter (December-January-February) and minimum in summer, but the second harmonic is important enough to produce a distinct secondary midwinter minimum. Locally, the second harmonic has largest amplitude in the Tropics and subtropics of the upper troposphere. At present, little is known concerning the fundamental cause of this semiannual variation. The problem is investigated here by focusing on the upper-tropospheric winds, whose angular momentum is an excellent proxy of global AAM. The annual variation of the rotational part of these winds (the part that contributes to the global AAM) is diagnosed in a nonlinear upper-tropospheric vorticity-equation model with specified horizontal wind divergence and transient-eddy forcing. The divergence forcing is the more important of the two, especially in the Tropics and subtropics, where it is associated with tropical hearing and cooling. Given the harmonics of the forcing, the model predicts the harmonics of the response, that is, the vorticity, from which the harmonics of angular momentum can then be calculated. The surprising but clear conclusion from this diagnosis is that the second harmonic of AAM arises more as a nonlinear response to the first harmonic of the divergence forcing than as a linear response to the second harmonic of the divergence forcing. This result has implications for general circulation model simulations of semiannual variations, not only of global AAM but also of other quantities. C1 Univ Colorado, Climate Diagnost Ctr, NOAA, CIRES, Boulder, CO 80309 USA. RP Huang, HP (reprint author), Univ Colorado, Climate Diagnost Ctr, NOAA, CIRES, Campus Box 216, Boulder, CO 80309 USA. NR 45 TC 8 Z9 8 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP 15 PY 2000 VL 13 IS 18 BP 3221 EP 3238 DI 10.1175/1520-0442(2000)013<3221:ALATAA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 364MN UT WOS:000089896300002 ER PT J AU Muller, D Cornell, EA Prevedelli, M Schwindt, PDD Zozulya, A Anderson, DZ AF Muller, D Cornell, EA Prevedelli, M Schwindt, PDD Zozulya, A Anderson, DZ TI Waveguide atom beam splitter for laser-cooled neutral atoms SO OPTICS LETTERS LA English DT Article ID WIRE; INTERFEROMETER; TRAP AB A laser-cooled neutral-atom beam from a low-velocity intense source is split into two beams while it is guided hy a magnetic-field potential. We generate our multimode beam-splitter potential with two current-carrying wires upon a glass substrate combined with an external transverse bias field. The atoms are guided around curves and a beam-splitter region within a 10-cm guide length. We achieve a maximum integrated flux of 1.5 x 10(5) atoms/s with a current density of 5 x 10(4) amp/cm(2) in the 100-mu m-diameter wires. The initial beam can be split into two beams with a 50/50 splitting ratio. (C) 2000 Optical Society of America. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. RP Muller, D (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. OI Prevedelli, Marco/0000-0002-3136-2392 NR 15 TC 51 Z9 54 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 15 PY 2000 VL 25 IS 18 BP 1382 EP 1384 DI 10.1364/OL.25.001382 PG 3 WC Optics SC Optics GA 353JT UT WOS:000089271600024 PM 18066224 ER PT J AU McFadden, GB Wheeler, AA Anderson, DM AF McFadden, GB Wheeler, AA Anderson, DM TI Thin interface asymptotics for an energy/entropy approach to phase-field models with unequal conductivities SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE phase-field model; sharp interface analysis; thin interface analysis; dendritic growth; isothermal asymptotics ID ANISOTROPIC SHARP; BOUNDARY MOTION; ORDER-PARAMETER; SOLIDIFICATION; KINETICS; TRANSITIONS; DYNAMICS; VECTOR; ENERGY; ALLOY AB Karma and Rappel [Phys. Rev. E 57 (1998) 4342] recently developed a new sharp interface asymptotic analysis of the phase-field equations that is especially appropriate for modeling dendritic growth at low undercoolings. Their approach relieves a stringent restriction on the interface thickness that applies in the conventional asymptotic analysis, and has the added advantage that interfacial kinetic effects can also be eliminated. However, their analysis focussed on the case of equal thermal conductivities in the solid and liquid phases; when applied to a standard phase-field model with unequal conductivities, anomalous terms arise in the limiting forms of the boundary conditions for the interfacial temperature that are not present in conventional sharp interface solidification models, as discussed further by Almgren [SIAM J, Appl. Math. 59 (1999) 2086]. In this paper we apply their asymptotic methodology to a generalized phase-field model which is derived using a thermodynamically consistent approach that is based on independent entropy and internal energy gradient functionals that include double wells in both the entropy and internal energy densities. The additional degrees of freedom associated with the generalized phase-field equations can be used to eliminate the anomalous terms that arise for unequal conductivities. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Southampton, Fac Math Studies, Southampton SO17 1BJ, Hants, England. George Mason Univ, Dept Math Sci, Fairfax, VA 22030 USA. RP Natl Inst Stand & Technol, Room 365,Bldg 820,100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. EM mcfadden@nist.gov RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 34 TC 43 Z9 43 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 EI 1872-8022 J9 PHYSICA D JI Physica D PD SEP 15 PY 2000 VL 144 IS 1-2 BP 154 EP 168 DI 10.1016/S0167-2789(00)00064-6 PG 15 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 352GX UT WOS:000089208000010 ER PT J AU Yildirim, T Ciraci, S Kilic, C Buldum, A AF Yildirim, T Ciraci, S Kilic, C Buldum, A TI First-principles investigation of structural and electronic properties of solid cubane and its doped derivatives SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; ORIENTATIONAL DISORDER; VIBRATIONAL-SPECTRA; FORCE MICROSCOPY; PHASE-TRANSITION; PSEUDOPOTENTIALS; DYNAMICS; MOLECULE; NMR AB The electronic and structural properties of molecular and solid cubane have been studied by first-principles, self-consistent field total energy calculations. Calculated molecular properties such as equilibrium geometry and electronic and vibrational spectra are found to be in good agreement with experimental data. Structural parameters and the energetics of both the low-temperature, orientationally ordered and high-temperature, orientationally disordered or plastic phases of solid cubane are determined. The valence band of solid cubane is derived from the molecular states; the energy gap between the lowest unoccupied and highest occupied molecular orbital bands is rather large due to the saturated carbon atoms. The effect of alkali-metal-atom doping on the electronic energy bands is investigated. It is found that the metallic band of doped cubane is derived from the undoped solid cubane's lowest conduction band with a significant contribution from the alkali-metal atom. C1 Bilkent Univ, Dept Phys, Ankara, Turkey. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Yildirim, T (reprint author), Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. RI yildirim, taner/A-1290-2009; Kilic, Cetin/E-1336-2011 OI Kilic, Cetin/0000-0003-2690-4940 NR 51 TC 21 Z9 22 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2000 VL 62 IS 11 BP 7625 EP 7633 DI 10.1103/PhysRevB.62.7625 PG 9 WC Physics, Condensed Matter SC Physics GA 355XH UT WOS:000089413500121 ER PT J AU Gasparov, LV Tanner, DB Romero, DB Berger, H Margaritondo, G Forro, L AF Gasparov, LV Tanner, DB Romero, DB Berger, H Margaritondo, G Forro, L TI Infrared and Raman studies of the Verwey transition in magnetite SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY; FE3O4; GAP AB We present infrared and Raman measurements of magnetite (Fe3O4). This material is known to undergo a metal-insulator and a structural transition (Verwey transition) at T-V = 120 K. The structural aspect of the Verwey transition is disclosed by the appearance of additional infrared-active and Raman-active phonons. The frequencies of the infrared-active phonons show no significant singularities at the transition whereas their linewidths increase. The frequency and linewidth of the Raman-active phonon at 670 cm(-1) change abruptly at the transition. For T 0.05) in the amount of each microparticulate diet or Artemia consumed. This data indicates that once first-feeding walleye start on a diet, they will consume that diet to a similar fixed level of satiation. Given the differences in the amounts of water and nutrients in the various diets, more nutrients were delivered to the gut of walleye larvae feeding on microparticulate diets than on the Artemia control. C1 NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, Seattle, WA 98112 USA. Oregon State Univ, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. US Fish & Wildlife Serv, Bozeman Fish Technol Ctr, Bozeman, MT USA. RP Rust, MB (reprint author), NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, Seattle, WA 98112 USA. NR 25 TC 11 Z9 14 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1353-5773 J9 AQUACULT NUTR JI Aquac. Nutr. PD SEP PY 2000 VL 6 IS 3 BP 153 EP 158 PG 6 WC Fisheries SC Fisheries GA 346RC UT WOS:000088884000003 ER PT J AU Johnson, KE Leitherer, C Vacca, WD Conti, PS AF Johnson, KE Leitherer, C Vacca, WD Conti, PS TI Hubble Space Telescope observations of He 2-10: Outflows and young super-star clusters SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : interactions; galaxies : starburst; galaxies : star clusters ID STARBURST GALAXY HENIZE-2-10; WOLF-RAYET GALAXIES; GLOBULAR-CLUSTERS; MASS-LOSS; INTERSTELLAR-MEDIUM; ANTENNAE GALAXIES; DWARF GALAXIES; EMISSION; GAS; SPECTROSCOPY AB We use Hubble Space Telescope (HST) WFPC2 optical images and GHRS ultraviolet spectroscopy to examine the recent star formation history and properties of the Wolf-Rayet galaxy He 2-10. The high spatial resolution afforded by HST has allowed the identification of a number of starburst knots, or "super-star clusters" (SSCs). The spatial morphology newly revealed by these HST images exhibits a prominent dust lane between the starburst regions known as A and B and a spur of material to the northwest of the nuclear region. Broadband photometry of the SSCs confirms that these objects have ages as young as a few Myr and masses up to 10(5) M-circle dot. Narrowband Ha photometry of the SSCs indicates large equivalent widths for nearly half of them, consistent with ages less than 10 Myr. Since an appreciable fraction of SSCs are this young, the star formation history necessarily must be strongly peaked and not continuous. GHRS UV spectra were obtained for sections of the two starburst regions and were used to determine the parameters of the starburst regions. For a stellar population produced in a single burst with stellar masses between 1 and 100 M-circle dot, the UV luminosities indicate regions A and B have masses between 1.6-2.6 x 10(6) M-circle dot and 2.6-6.6 x 10(4) M-circle dot, respectively. The total starburst mass was between 1 and 100 M-circle dot consistent with the UV luminosity ranges between 1.6 and 2.6 x 10(6) M-circle dot and 2.6 and 6.6 x 10(4) M-circle dot for regions A and B, respectively. The observed integrated H alpha flux is similar to that predicted by the models, implying that the leakage and/or dust absorption of Lyman continuum photons from the starburst regions is small. The integrated Ha equivalent widths of the two regions are substantially smaller than predicted, We attribute this to contamination by the continuum in the starburst regions (the starburst knots do not uniformly fill the GHRS apertures). The UV spectroscopy of starburst region A indicates a large-scale outflow of the interstellar medium of He 2-10 with speeds of at least 360 km s(-1) and a total mass of at least 106 Mo. We estimate that the mass in metals which He 2-10 will expel is enough to raise primordial abundances in approximate to 1 Mpc(3) to 10(-3) to 10(-2) solar. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Inst Astron, Honolulu, HI 96822 USA. RP Johnson, KE (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 67 TC 75 Z9 75 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1273 EP 1288 DI 10.1086/301541 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300009 ER PT J AU Penton, SV Stocke, JT Shull, JM AF Penton, SV Stocke, JT Shull, JM TI The local Ly alpha forest. I. Observations with the GHRS/G160M on the Hubble space telescope SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : halos; intergalactic medium; quasars : absorption lines; ultraviolet : galaxies ID LINE KEY PROJECT; HIGH-RESOLUTION SPECTROGRAPH; SPECTROSCOPIC-EXPLORER OBSERVATIONS; HIGH-VELOCITY CLOUDS; ACTIVE GALACTIC NUCLEI; LOW-REDSHIFT; LYMAN-ALPHA; ABSORPTION-LINES; INTRINSIC ABSORPTION; INTERGALACTIC MEDIUM AB We present the target selection, observations, and data reduction and analysis process for a program aimed at discovering numerous, weak (equivalent width less than or equal to 100 m Angstrom) Ly alpha absorption lines in the local universe (0.003 less than or equal to z less than or equal to 0.069). The purpose of this program is to study the physical conditions of the local intergalactic medium, including absorber distributions in Doppler width and H I column density, redshift evolution of absorber number density, line-of-sight two-point correlation function, and the baryonic content and metallicity. By making use of large-angle, nearby galaxy redshift surveys, we will investigate the relationship (if any) between these Ly alpha absorbers and galaxies, superclusters, and voids. In Paper I we present high-resolution (similar to 19 km s(-1)) spectroscopic observations of 15 very bright (V less than or equal to 14.5) active galactic nuclei (AGNs) targets made with the Goddard High-Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST). We find 81 definite (greater than or equal to4 sigma) and 30 possible (3-4 sigma) Ly alpha absorption lines in these spectra, which probe a total path length of 116,000 km s(-1) (Deltaz similar to 0.4) at very low redshift (z less than or equal to 0.069) and column density (12.5 less than or equal to log N(HI) less than or equal to 14.5). We found numerous metal lines arising in the Milky Way halo, including absorption from high-velocity clouds in 10 of 15 sight lines and numerous absorptions intrinsic to the target AGN. We present reduced spectra, absorption-line lists, "pie diagrams," showing the known galaxy distributions in the direction of each target, and nearest galaxy tables for each absorber. In Papers TI and III, we use the data presented here to determine the basic physical characteristics of the low-z Ly alpha forest and to investigate the relationship of the absorbers to the local galaxy distribution. C1 Univ Colorado, Dept Astrophys & Planetary Sci, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. RP Penton, SV (reprint author), Univ Colorado, Dept Astrophys & Planetary Sci, Ctr Astrophys & Space Astron, Campus Box 391, Boulder, CO 80309 USA. EM spenton@casa.colorado.edu; stocke@casa.colorado.edu; mshull@casa.colorado.edu NR 82 TC 67 Z9 67 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2000 VL 130 IS 1 BP 121 EP 164 DI 10.1086/317345 PG 44 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 372LY UT WOS:000165236200005 ER PT J AU Cheok, GS Stone, WC Lipman, RR Witzgall, C AF Cheok, GS Stone, WC Lipman, RR Witzgall, C TI Ladars for construction assessment and update SO AUTOMATION IN CONSTRUCTION LA English DT Article; Proceedings Paper CT 16th International Symposium on Automation and Robotics in Construction (ISARC 99) CY SEP 22-24, 1999 CL MADRID, SPAIN SP Int Assoc Automat & Robot Construct, Int Federat Automat Control, IEEE, Robot & Automat Soc DE 3-D models; construction automation; cut-and-fill calculation; laser radar; laser imaging; metrology; terrain modeling AB Work at the National Institute of Standards and Technology (NIST) on laser radar imaging of a construction site is described. The objective of the NIST research is to make measurements required in a construction project quicker and cheaper than current practice and to do so without impacting existing operations. This can be done by developing techniques for real-time assessment and documentation in terms of 3-D as-built models of the construction process. Once developed, this technology may be used for other applications such as condition assessment of a hazardous environment where human intervention would be impossible. (C) 2000 Published by Elsevier Science B.V. C1 NIST, Construct Metrol & Automat Grp, Gaithersburg, MD 20899 USA. NIST, Comp Integrated Construct Environm Grp, Gaithersburg, MD 20899 USA. NIST, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. RP Cheok, GS (reprint author), NIST, Construct Metrol & Automat Grp, Gaithersburg, MD 20899 USA. NR 5 TC 27 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-5805 J9 AUTOMAT CONSTR JI Autom. Constr. PD SEP PY 2000 VL 9 IS 5-6 BP 463 EP 477 DI 10.1016/S0926-5805(00)00058-3 PG 15 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA 335EJ UT WOS:000088230300005 ER PT J AU Levin, PS Tolimieri, N Nicklin, M Sale, PF AF Levin, PS Tolimieri, N Nicklin, M Sale, PF TI Integrating individual behavior and population ecology: the potential for habitat-dependent population regulation in a reef fish SO BEHAVIORAL ECOLOGY LA English DT Article DE damselfish; habitat structure; ideal free distribution; recruitment; Stegastes planifrons ID IDEAL-FREE-DISTRIBUTION; SIZE-SELECTIVE MORTALITY; COMPETITIVE INTERACTIONS; DECAPOD CRUSTACEANS; PATCH SIZE; RECRUITMENT; DENSITY; SETTLEMENT; DAMSELFISH; PREDATION AB We used the predictions of the ideal free and ideal despotic distributions (IFD and IDD, respectively) as a basis to evaluate the link between spatial heterogeneity, behavior, and population dynamics in a Caribbean coral reef fish. Juvenile three-spot damselfish (Stegastes planifrons) were more closely aggregated in patch reef habitat than on continuous back reef. Agonistic interactions were more frequent but feeding rates were lower in the patch versus the continuous reef habitat. Growth rates were lower in patch reef habitat than on the continuous reef, but mortality rates did not differ. A separate experiment using standard habitat units demonstrated that the patterns observed in natural habitat were the result of the spatial distribution of the habitat patches rather than resource differences between habitats. Our results do not follow the predictions of simple IFD or IDD models. This deviation from IFD and IDD predictions may be the result of a number of factors, including lack of perfect information about habitat patches, high movement costs, and higher encounter rates of dispersed patches. Our results demonstrate that behavioral interactions are an integral part of population dynamics and that it is necessary to consider the spatial organization of the habitat in both behavioral and ecological investigations. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Univ Auckland, Leigh Marine Lab, Warkworth, New Zealand. Northeastern Univ, Dept Biol, Boston, MA 02115 USA. Univ Windsor, Dept Biol, Windsor, ON N9B 3P4, Canada. RP Levin, PS (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM phil.levin@noaa.gov NR 85 TC 38 Z9 38 U1 2 U2 23 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1045-2249 EI 1465-7279 J9 BEHAV ECOL JI Behav. Ecol. PD SEP-OCT PY 2000 VL 11 IS 5 BP 565 EP 571 DI 10.1093/beheco/11.5.565 PG 7 WC Behavioral Sciences; Biology; Ecology; Zoology SC Behavioral Sciences; Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Zoology GA 358WL UT WOS:000089580100014 ER PT J AU Baker, DM Davies, B Dickhoff, WW Swanson, P AF Baker, DM Davies, B Dickhoff, WW Swanson, P TI Insulin-like growth factor I increases follicle-stimulating hormone (FSH) content and gonadotropin-releasing hormone-stimulated FSH release from coho salmon pituitary cells in vitro SO BIOLOGY OF REPRODUCTION LA English DT Article DE anterior pituitary; FSH; growth factors; insulin; LH; puberty ID TROUT ONCORHYNCHUS-MYKISS; FEMALE RAINBOW-TROUT; REPRODUCTIVE-CYCLE; GTH-II; IGF-I; FACTOR SYSTEM; EXPRESSION; RECEPTORS; BINDING; PUBERTY AB The effects of insulin-like growth factor I (IGF-I) and insulin on the function of coho salmon gonadotropes in vitro were investigated. Dispersed pituitary cells from immature coho salmon (Oncorhynchus kisutch) were incubated with ICF-I for 1, 3, 7, or 10 days, then incubated with salmon GnRH for an additional 24 h. Medium FSH content before and after GnRH treatment and intracellular FSH content after GnRH treatment were measured. Incubation of pituitary cells with ICF-I for 7 or 10 days increased GnRH-stimulated FSH release and remaining cell content, but did not affect basal release. To examine the specificity of the effects of IGF-I, we compared FSH release and cell content of FSH and LH after 10-day incubation with a range of concentrations of IGF-I or insulin. Incubation with physiological concentrations of IGF-I resulted in significantly higher GnRH-stimulated FSH release and remaining cell content of FSH and LH. Conversely, supraphysiological concentrations of insulin were required to produce more moderate effects on gonadotropin levels. These results suggest that elevation of gonadotropin levels by ICF-I may be one mechanism by which somatic growth and nutrition promote pubertal development in salmon. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. NW Fisheries Sci Ctr, Seattle, WA USA. RP Baker, DM (reprint author), Univ Washington, Sch Fisheries, Box 355020, Seattle, WA 98195 USA. NR 43 TC 45 Z9 46 U1 0 U2 3 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD SEP PY 2000 VL 63 IS 3 BP 865 EP 871 DI 10.1095/biolreprod63.3.865 PG 7 WC Reproductive Biology SC Reproductive Biology GA 348EK UT WOS:000088972400029 PM 10952933 ER PT J AU Criales, MM Bello, MJ Yeung, C AF Criales, MM Bello, MJ Yeung, C TI Diversity and recruitment of penaeoid shrimps (Crustacea : decapoda) at Bear Cut, Biscayne Bay, Florida, USA SO BULLETIN OF MARINE SCIENCE LA English DT Article ID MANGROVE ESTUARY; MERGUIENSIS; CARPENTARIA; ABUNDANCE; TRANSPORT; AUSTRALIA; GULF AB Postlarval and juvenile penaeoid shrimps were collected with moored channel nets at Bear Cut, a tidal pass between the Atlantic and Biscayne Bay, Florida, from January through December 1994. Results show a much higher number of species than in previous reports. Among juveniles, Metapenaeopsis spp., which comprised five species, was the most abundant and diverse genus. Two of them, M. martinella and M. hobbsi, constitute new records for North American waters. Despite the abundance of Metapenaeopsis spp., neither small juveniles (CL <2.0 mm) nor larger adults (CL >12.5 mm) were caught at Bear Cut. The genus Farfantepenaeus was represented by the pink shrimp, F. duorarum, and the pink spotted shrimp, F. brasiliensis, in a proportion of 2:1. Monthly mean densities of the juvenile penaeoids Farfantepenaeus spp., Metapenaeopsis spp., Sicyonia spp., and Rimapenaeus constrictus showed a seasonal pattern. Densities were lowest between May and October, and highest between December and February. A two-factor repeated-measures ANOVA of density by depth and tidal period showed that depth does not have a significant effect on the density for any of the juvenile taxa, but the effect of the tidal period is highly significant (alpha = 0.05). The reverse result was obtained for Farfantepenaeus spp, postlarvae; depth effect was significant but not tidal period. F. duorarum and F brasiliensis juveniles exhibited the greatest carapace length in January and February, when the highest density of shrimps were leaving the Bay. Farfantepenaeus spp. postlarvae showed a bimodal distribution with peaks in March and November. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. RP Criales, MM (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. NR 71 TC 9 Z9 9 U1 1 U2 2 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 2000 VL 67 IS 2 BP 773 EP 788 PG 16 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 371PD UT WOS:000165186600007 ER PT J AU Dabberdt, WF Hales, J Zubrick, S Crook, A Krajewski, W Doran, JC Mueller, C King, C Keener, RN Bornstein, R Rodenhuis, D Kocin, P Rossetti, MA Sharrocks, F Stanley, EM AF Dabberdt, WF Hales, J Zubrick, S Crook, A Krajewski, W Doran, JC Mueller, C King, C Keener, RN Bornstein, R Rodenhuis, D Kocin, P Rossetti, MA Sharrocks, F Stanley, EM TI Forecast issues in the urban zone: Report of the 10th Prospectus Development Team of the US Weather Research Program SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID HEAT-STORAGE; MODEL; SNOW AB The 10th Prospectus Development Team (PDT-IO) of the U.S. Weather Research Program was charged with identifying research needs and opportunities related to the short-term prediction of weather and air quality in urban forecast zones. Weather has special and significant impacts on large numbers of the U.S. population who live in major urban areas. It is recognized that urban users have different weather information needs than do their rural counterparts. Further, large urban areas can impact local weather and hydrologic;ic processes in various ways. The recommendations of the team emphasize that human life and well-being in urban areas can be protected and enjoyed to a significantly greater degree. In particular, PDT-IO supports the need for 1) improved access to real-time weather information, 2) improved tailoring of weather data to the specific needs of individual user groups, and 3) more user-specific forecasts of weather and air quality. Specific recommendations fall within nine thematic areas: 1) development of a user-oriented weather database; 2) focused research on the impacts of visibility and icing on transportation; 3) improved understanding and forecasting of winter storms; 4) improved understanding and Forecasting of convective storms; 5) improved forecasting of intense/severe lightning; 6) further research into the impacts of large urban areas on the location and intensity of urban convection; 7) focused research on the application of mesoscale forecasting in support of emergency response and air quality; 8) quantification and reduction of uncertainty in hydrological, meteorological, and air quality modeling; and 9) the need for improved observing systems. An overarching recommendation of PDT-10 is that research into understanding and predicting weather impacts in urban areas should receive increased emphasis by the atmospheric science community at large, and that urban weather should be a focal point of the U.S. Weather Research Program. C1 Natl Ctr Atmospher Res, Off Director, Boulder, CO 80307 USA. Envair, Pasco, WA USA. Natl Weather Serv, Natl Ocean & Atmospher Adm, Sterling, VA USA. Univ Iowa, Iowa Inst Hydraul Res, Iowa City, IA 52242 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Ocean & Atmospher Adm, Environm Techniques Lab, Boulder, CO USA. Duke Energy, Charlotte, NC USA. San Jose State Univ, San Jose, CA 95192 USA. Natl Weather Serv, Kansas City, MO USA. Weather Channel, Atlanta, GA USA. US Dept Transportat, Cambridge, MA USA. Fed Emergency Management Assoc, Washington, DC USA. RP Dabberdt, WF (reprint author), Natl Ctr Atmospher Res, Off Director, POB 3000, Boulder, CO 80307 USA. NR 37 TC 32 Z9 33 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2047 EP 2064 DI 10.1175/1520-0477(2000)081<2047:FIITUZ>2.3.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100002 ER PT J AU Rappaport, EN AF Rappaport, EN TI Loss of life in the United States associated with recent Atlantic tropical cyclones SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID HURRICANE AB A datahase was established for the period 1970-99 to assess the threat to life in the contiguous United States and adjacent coastal waters from Atlantic tropical cyclones. Freshwater floods caused more than one-half of the 600 U.S. deaths directly associated with tropical cyclones or their remnants during that 30-year period. More than three-quarters of the victims under age 13 died in rain-induced floods. Most fatalities occurred in inland counties. Storm surge losses were significantly (but perhaps only temporarily) less than in previous periods of comparable length. This paper presents a statistical summary of the casualties, explores reasons for the losses, and reviews efforts to mitigate the threats. C1 NWS, NOAA, TPC, NHC, Miami, FL 33165 USA. RP Rappaport, EN (reprint author), NWS, NOAA, TPC, NHC, 11691 SW 17th St, Miami, FL 33165 USA. NR 22 TC 118 Z9 120 U1 0 U2 13 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2065 EP 2073 DI 10.1175/1520-0477(2000)081<2065:LOLITU>2.3.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100003 ER PT J AU Landsea, CW Knaff, JA AF Landsea, CW Knaff, JA TI How much skill was there in forecasting the very strong 1997-98 El Nino? SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SEA-SURFACE TEMPERATURES; SOUTHERN OSCILLATION; OCEAN MODEL; PREDICTION; ENSO AB The very strong 1997-98 El Nino was the first major event in which numerous forecasting groups participated in its real-time prediction. A previously developed simple statistical tool-the El Nino-Southern Oscillation Climatology and Persistence (ENSO-CLIPER) model-is utilized as a baseline for determination of skill in forecasting this event. Twelve statistical and dynamical models were available in real time for evaluation. Some of the models were able to outperform ENSO-CLIPER in predicting either the onset or the decay of the 1997-98 El Nino, but none were successful at both for a medium-range two season (6-8 months) lead time. There were no models, including ENSO-CLIPER, able to anticipate even one-half of the actual amplitude of the El Nino's peak at medium-range (6-11 months) lead. In addition, none of the models showed skill (i.e., lower root-mean-square error than ENSO-CLIPER) at the zero season (0-2 months) through the two season (6-8 months) lead times. No dynamical model and only two of the statistical models [the canonical correlation analysis (CCA) and the constructed analog (ANALOG)] outperformed ENSO-CLIPER by more than 5% of the root-mean-square error at the three season (9-11 months) and four season (12-14 months) lead time. El Nino impacts were correctly anticipated by national meteorological centers one half-year in advance, because of the tendency for El Nino events to persist into and peak during the boreal winter. Despite this, the zero to two season (0-8 month) forecasts of the El Nino event itself were no better than ENSO-CLIPER and were, in that sense, not skillful-a conclusion that remains unclear to the general meteorological and oceanographic communities. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. NOAA, Cooperat Inst Res Atmosphere, Ft Collins, CO USA. RP Landsea, CW (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RI Knaff, John /F-5599-2010 OI Knaff, John /0000-0003-0427-1409 NR 38 TC 99 Z9 103 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2107 EP 2119 DI 10.1175/1520-0477(2000)081<2107:HMSWTI>2.3.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100006 ER PT J AU Buizer, JL Foster, J Lund, D AF Buizer, JL Foster, J Lund, D TI Global impacts and regional actions: Preparing for the 1997-98 El Nino SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB It has been estimated that severe El Nino-related flooding and droughts in Africa, Latin America, North America, and Southeast Asia resulted in more than 22 000 lives lost and in excess of $36 billion in damages during 1997-98. As one of the most severe events this century, the 1997-98 El Nino was unique not only in terms of physical magnitude, but also in terms of human response. This response was made possible by recent advances in climate-observing and forecasting systems, creation and dissemination of forecast information by institutions such as the International Research institute fur Climate Prediction and NOAA's Climate Prediction Center, and individuals in climate-sensitive sectors willing to act on forecast information by incorporating it into their decision-making. The supporting link between the forecasts and their practical application was a product of efforts by several national acid international organizations, and a primary focus of the United States National Oceanic and Atmospheric Administration Office of Global Programs (NOAA/OGP). NOAA/OGP over the last decade has supported pilot projects in Latin America, the Caribbean, the South Pacific, Southeast Asia, and Africa to improve transfer of forecast information to climate sensitive sectors, study linkages between climate and human health, and distribute climate information products in certain areas. Working with domestic and international partners, NOAA/OGP helped organize a total of 11 "Climate Outlook Fora" around the world during the 1997-98 El Nino. At each Outlook Forum, climatologists and meteorologists created regional, consensus-based, seasonal precipitation forecasts and representatives from climate-sensitive sectors discussed options for applying forecast information. Additional ongoing activities during 1997-98 included research programs focused on the social and economic impacts of climate change and the regional manifestations of global-scale climate variations and their effect on decision-making in climate-sensitive sectors in the United States. The overall intent of NOAA/OGP's activities was to make experimental forecast information broadly available to potential users, and to foster a learning process on how seasonal-to-interannual forecasts could be applied in sectors susceptible to climate variability. This process allowed users to explore the capabilities and limitations of climate forecasts currently available, and forecast producers to receive feedback on the utility of their products. Through activities in which NOAA/OGP and its partners were involved, it became clear that further application of forecast information will be aided by improved forecast accuracy and detail, creation of common validation techniques, continued training in forecast generation and application, alternate methods for presenting forecast information, and a systematic strategy for creation and dissemination of forecast products. C1 NOAA, OGP, Silver Spring, MD 20910 USA. RP Foster, J (reprint author), NOAA, OGP, 1100 Wayne Ave,Suite 1225, Silver Spring, MD 20910 USA. NR 4 TC 22 Z9 22 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2121 EP 2139 DI 10.1175/1520-0477(2000)081<2121:GIARAP>2.3.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100007 ER PT J AU Williams, CN Basist, A Peterson, TC Grody, N AF Williams, CN Basist, A Peterson, TC Grody, N TI Calibration and verification of land surface temperature anomalies derived from the SSM/I SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID MICROWAVE BRIGHTNESS TEMPERATURES; SNOW COVER; IMAGER AB The current network of internationally exchanged in situ station data is not distributed evenly nor densely around the globe. Consequently, the in situ data contain insufficient information to identify fine spatial structure and variations over many areas of the world. Therefore, satellite observations need to be blended with in situ data to obtain higher resolution over the global land surface. Toward this end, the authors calibrated and independently verified an algorithm that derives land surface temperatures from the Special Sensor Microwave/Imager (SSM/I). This study explains the technique used to refine a set of equations that identify various surface types and to make corresponding dynamic emissivity adjustments. This allowed estimation of the shelter height temperatures from the seven channel measurements flown on the SSM/I instrument. Data from first-order in situ stations over the eastern half of the United States were used for calibration and intersatellite adjustment. The results show that the observational difference between the in situ point measurements and the SSM/I-derived areal values is about 2 degrees C With statistical characteristics largely independent of surface type. High-resolution monthly mean anomalies generated from the U.S. cooperative network served as independent verification over the same study area. This verification work determined that the standard deviation of the monthly mean anomalies: is 0.76 degrees C at each 1 degrees x 1 degrees grid box. This level of accuracy is adequate to blend the SSM/I-derived temperature anomaly data with in situ data for monitoring global temperature anomalies in finer detail. C1 NOAA, Natl Climat Data Ctr, NESDIS, Asheville, NC 28801 USA. NOAA, Off Res & Applicat, NESDIS, Camp Springs, MD USA. RP Williams, CN (reprint author), NOAA, Natl Climat Data Ctr, NESDIS, 151 Patton Ave, Asheville, NC 28801 USA. NR 24 TC 21 Z9 21 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2141 EP 2156 DI 10.1175/1520-0477(2000)081<2141:CAVOLS>2.3.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100008 ER PT J AU Peterson, TC Basist, AN Williams, CN Grody, NC AF Peterson, TC Basist, AN Williams, CN Grody, NC TI A blended satellite - In situ near-global surface temperature dataset SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID CLIMATE DATA; NETWORK; SERIES AB A near-global surface temperature dataset was produced by blending several sources of information. For the oceans, these include in situ and infrared satellite-derived sea surface temperatures that were already processed into a monthly product. Land data analysis uses two sources of data. The first is high quality monthly in situ reports from the Global Historical Climatologic Network with more than 1000 stations from around the world. The second source of information is the recently developed passive microwave satellite-derived land surface temperature derivation methodology described in Williams ct al. These data are blended on a 1 degrees x 1 degrees grid that excludes only ice- and snow-covered regions lacking in situ observations. Available starting in January 1992 and updated 10 days after the end of the calendar month, this product is useful for monitoring regional climate anomalies and provides insights into climate variations. C1 NOAA, Natl Climat Data Ctr, NESDIS, Asheville, NC 28801 USA. NOAA, Off Res & Applicat, NESDIS, Camp Springs, MD USA. RP Peterson, TC (reprint author), NOAA, Natl Climat Data Ctr, NESDIS, 151 Patton Ave, Asheville, NC 28801 USA. NR 14 TC 14 Z9 16 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2157 EP 2164 DI 10.1175/1520-0477(2000)081<2157:ABSSNS>2.3.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100009 ER PT J AU Kellison, GT Eggleston, DB Burke, JS AF Kellison, GT Eggleston, DB Burke, JS TI Comparative behaviour and survival of hatchery-reared versus wild summer flounder (Paralichthys dentatus) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ONCORHYNCHUS-MYKISS; JAPANESE FLOUNDER; LIFE-HISTORY; BLUE CRABS; TROUT; SAND; JUVENILES; SELECTION; RESPONSES; OLIVACEUS AB We describe the use of laboratory trials to compare substrate-specific behaviour and susceptibility to predation of hatchery-reared (HR) versus wild summer flounder (Paralichthys dentatus) juveniles. HR fish spent significantly more time swimming in the water column than wild fish and took significantly longer to become cryptic on the benthos than wild fish, regardless of substrate type. In predation trials with a blue crab (Callinectes sapidus) predator, nauve HR fish were significantly more susceptible to predation than wild fish. Antipredator-conditioned HR fish were significantly less susceptible to predation than nauve HR fish but significantly more susceptible than wild fish, irrespective of substrate. The modified behavioural patterns and increased susceptibility to predation of HR individuals observed in this study indicate that flounder reared in psychosensory-deprived hatchery environments may be poorly equipped to survive in natural habitats; they also indicate that it may be possible to mitigate detrimental behavioural patterns by exposing nauve HR fish to natural stimuli before release into natural environments. These results have important implications for stock enhancement, suggesting that stocked organisms are more likely to achieve postrelease survival if they are conditioned with natural stimuli prior to release into the wild. C1 N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. Natl Ocean Serv, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. RP Kellison, GT (reprint author), N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Box 8208, Raleigh, NC 27695 USA. NR 36 TC 63 Z9 65 U1 0 U2 9 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 2000 VL 57 IS 9 BP 1870 EP 1877 DI 10.1139/cjfas-57-9-1870 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 349FV UT WOS:000089033700011 ER PT J AU Fahnenstiel, GL Stone, RA McCormick, MJ Schelske, CL Lohrenz, SE AF Fahnenstiel, GL Stone, RA McCormick, MJ Schelske, CL Lohrenz, SE TI Spring isothermal mixing in the Great Lakes: evidence of nutrient limitation and nutrient-light interactions in a suboptimal light environment SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PHYTOPLANKTON GROWTH-RATES; MICHIGAN PHYTOPLANKTON; PHOSPHORUS DEFICIENCY; CHLOROPHYLL-A; ZEBRA MUSSEL; DYNAMICS; BIOMASS; ONTARIO; CARBON; BAY AB During the spring isothermal mixing period (April-May) in 1993-1995, photosynthesis-irradiance and growth-irradiance experiments were conducted in Lakes Erie, Huron, Michigan, and Ontario to assess light limitation. Additionally, nutrient enrichment experiments were conducted in Lake Ontario. Results from the photosynthesis-irradiance experiments suggested that phytoplankton communities in all the lakes can be either light limited or light saturated, as the threshold parameter (I-k) was similar to mean water column irradiances (mean (I) over bar(wc), ratio = 1.0). Growth-irradiance experiments also suggested the potential for light saturation; mean daily irradiance exceeded the threshold growth irradiance (I-k,I-g) in 95% of cases. Growth rates became light saturated at lower irradiances than photosynthetic rates. Evidence for a nutrient-light interaction in controlling in situ growth rates was also found in the nutrient enrichment experiments at incubation irradiances greater than or equal to (I) over bar(wc). Our results suggest that an interaction between nutrients and light is often controlling phytoplankton growth during spring mixing in the Great Lakes. The role of these nutrient-light interactions has increased in the past decade due to increased light availability in the lower lakes caused by phosphorus load reductions and the filtering activities of nonindigenous mussels. C1 NOAA, Lake Michigan Field Stn, GLERL, Muskegon, MI 49441 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. Univ So Mississippi, Inst Marine Sci, Stennis Space Ctr, MS 39529 USA. RP Fahnenstiel, GL (reprint author), NOAA, Lake Michigan Field Stn, GLERL, 1431 Beach St, Muskegon, MI 49441 USA. OI Lohrenz, Steven/0000-0003-3811-2975 NR 39 TC 37 Z9 37 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 2000 VL 57 IS 9 BP 1901 EP 1910 DI 10.1139/cjfas-57-9-1901 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 349FV UT WOS:000089033700014 ER PT J AU Scholz, NL Truelove, NK French, BL Berejikian, BA Quinn, TP Casillas, E Collier, TK AF Scholz, NL Truelove, NK French, BL Berejikian, BA Quinn, TP Casillas, E Collier, TK TI Diazinon disrupts antipredator and homing behaviors in chinook salmon (Oncorhynchus tshawytscha) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID CHEMICAL ALARM SIGNALS; RAINBOW-TROUT; CYPRINODON-VARIEGATUS; ENDOCRINE FUNCTION; MOLECULAR-FORMS; ACETYLCHOLINESTERASE; PESTICIDE; PREDATION; TOXICITY; PARR AB Neurotoxic pesticides are known to contaminate surface waters that provide habitat for salmonids, including some listed for protection under the U.S. Endangered Species Act. Despite their widespread use, the impacts of these pesticides on the neurological health of wild salmon are not well understood. Of particular concern are the organophosphate and carbamate insecticides that block synaptic transmission by inhibiting neuronal acetylcholinesterase. Here we assess the effects of diazinon, an organophosphate insecticide, on alarm pheromone induced antipredator responses and homing behavior in chinook salmon (Oncorhynchus tshawytscha). Nominal exposure concentrations (0.1, 1.0, and 10.0 mu g.L-1) were chosen to emulate diazinon pulses in the natural environment. In the antipredator study, diazinon had no effect on swimming behavior or visually guided food capture. However, the pesticide significantly inhibited olfactory-mediated alarm responses at concentrations as low as 1.0 mu g.L-1. Similarly, homing behavior was impaired at 10.0 mu g.L-1. Our results suggest that olfactory-mediated behaviors are sensitive to anticholinesterase neurotoxicity in salmonids and that short-term, sublethal exposures to these insecticides may cause significant behavioral deficits. Such deficits may have negative consequences for survival and reproductive success in these fish. C1 Natl Ctr Marine Res, NOAA, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Scholz, NL (reprint author), Natl Ctr Marine Res, NOAA, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Scholz, Nathaniel/L-1642-2013 OI Scholz, Nathaniel/0000-0001-6207-0272 NR 40 TC 123 Z9 133 U1 2 U2 35 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 2000 VL 57 IS 9 BP 1911 EP 1918 DI 10.1139/cjfas-57-9-1911 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 349FV UT WOS:000089033700015 ER PT J AU Buckley, LJ Lough, RG Peck, MA Werner, FE AF Buckley, LJ Lough, RG Peck, MA Werner, FE TI Comment: Larval Atlantic cod and haddock growth models, metabolism, ingestion, and temperature effects SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Editorial Material ID GADUS-MORHUA; MELANOGRAMMUS-AEGLEFINUS; FISH; RESPIRATION; EFFICIENCY; RATES C1 Univ Rhode Isl, Grad Sch Oceanog, NOAA, CMER Program, Narragansett, RI 02882 USA. Natl Marine Fisheries Serv, NOAA, Woods Hole Lab, Woods Hole, MA 02543 USA. Univ N Carolina, Marine Sci Program, Chapel Hill, NC 27599 USA. RP Buckley, LJ (reprint author), Univ Rhode Isl, Grad Sch Oceanog, NOAA, CMER Program, S Ferry Rd, Narragansett, RI 02882 USA. RI Peck, Myron/H-6164-2011 NR 21 TC 18 Z9 18 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 2000 VL 57 IS 9 BP 1957 EP 1960 DI 10.1139/cjfas-57-9-1957 PG 4 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 349FV UT WOS:000089033700019 ER PT J AU Vogel, GL Mao, Y Chow, LC Proskin, HM AF Vogel, GL Mao, Y Chow, LC Proskin, HM TI Fluoride in plaque fluid, plaque, and saliva measured for 2 hours after a sodium fluoride monofluorophosphate rinse SO CARIES RESEARCH LA English DT Article DE fluoride; plaque; plaque fluid; rinse; saliva ID DENTAL PLAQUE; 2-SOLUTION RINSE; NAF; REMINERALIZATION; DENTIFRICES; EFFICACY; INVITRO; ENAMEL; INVIVO; MFP AB Sodium monofluorophosphate (NaMFP) and sodium fluoride (NaF) are the two most common sources of fluoride used in currently marketed fluoride dentifrices. The purpose of this study was to investigate the effect of mouth rinses containing NaF or NaMFP on the concentrations of fluoride, or the MFP ion, in saliva, whole plaque, and plaque fluid. Twelve subjects abstained from tooth brushing for 48 h, fasted overnight, and then rinsed 1 min with 12 mmol/l (228 ppm [mu g/g] F) NaF or NaMFP in the morning. Before the rinse and at 30, 60 and 120 min afterwards, upper and lower molar and premolar plaque samples and whole saliva samples were collected. Aliquots of plaque fluid and centrifuged saliva were obtained from these samples, and the whole plaque residue acid extracted. The F and MFP concentrations were then measured in these samples using ultramicro methods. For both rinses, a higher concentration of plaque fluid fluoride was found at lower molar sites while the reverse was true for the whole plaque fluoride. Furthermore, for both rinses, plaque fluid, whole plaque, but not salivary, fluoride concentrations were above baseline at 120 min. Following the NaMFP rinse, a substantial amount of unhydrolyzed MFP was found in plaque fluid and saliva. Although there was a very large range in these measurements, fluoride in plaque fluid (excluding fluoride in unhydrolyzed MFP) and whole plaque were significantly (p<0.05) greater after the NaF rinse at all time periods. In saliva, the NaF rinse produced a statistically significant greater salivary fluoride (excluding fluoride in unhydrolyzed MFP) only at 60 min. The lack of a clear correlation between these measurements and clinical studies suggest a novel mechanism may enhance the effectiveness of NaMFP dentifrices. Copyright (C) 2000 S. Karger AG, Basel. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Howard M Proskin & Associates, Rochester, NY USA. RP Vogel, GL (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Room A153,Bldg 224, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE05354, DE10840] NR 39 TC 32 Z9 36 U1 0 U2 3 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD SEP-OCT PY 2000 VL 34 IS 5 BP 404 EP 411 DI 10.1159/000016615 PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 353NA UT WOS:000089280300006 PM 11014907 ER PT J AU Ablowitz, MJ Biondini, G Ostrovsky, LA AF Ablowitz, MJ Biondini, G Ostrovsky, LA TI Optical solitons: Perspectives and applications SO CHAOS LA English DT Article ID NONLINEAR OPTICS; PULSE DYNAMICS; GENERATION AB This article serves as an introduction to the focus issue on optical solitons. After a short review of the history of solitons and the field of integrable systems, a brief overview of the development of nonlinear optics and optical solitons is provided. Next, the various contributions to this focus issue are presented, and a few separate remarks are devoted to optical communications, where solitons promise to play a decisive role in the next generation of commercial systems. (C) 2000 American Institute of Physics. [S1054-1500(00)02303-X]. C1 Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. Northwestern Univ, Dept Engn Sci & Appl Math, Evanston, IL 60208 USA. Univ Colorado, NOAA, Environm Technol Lab, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. RP Ablowitz, MJ (reprint author), Univ Colorado, Dept Appl Math, Campus Box 526, Boulder, CO 80309 USA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 52 TC 25 Z9 25 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD SEP PY 2000 VL 10 IS 3 BP 471 EP 474 AR PII [S1054-1500(00)02303-X] DI 10.1063/1.1310721 PG 4 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 352BK UT WOS:000089194500001 ER PT J AU Cundiff, ST Collings, BC Bergman, K AF Cundiff, ST Collings, BC Bergman, K TI Polarization locked vector solitons and axis instability in optical fiber SO CHAOS LA English DT Article ID PULSE-PROPAGATION; LASERS; DISPERSION; EVOLUTION; LOCKING; DEVICES; MEDIA AB We experimentally observe polarization-locked vector solitons in optical fiber. Polarization locked-vector solitons use nonlinearity to preserve their polarization state despite the presence of birefringence. To achieve conditions where the delicate balance between nonlinearity and birefringence can survive, we studied the polarization evolution of the pulses circulating in a laser constructed entirely of optical fiber. We observe two distinct states with fixed polarization. This first state occurs for very small values birefringence and is elliptically polarized. We measure the relative phase between orthogonal components along the two principal axes to be +/-pi/2. The relative amplitude varies linearly with the magnitude of the birefringence. This state is a polarization locked vector soliton. The second, linearly polarized, state occurs for larger values of birefringence. The second state is due to the fast axis instability. We provide complete characterization of these states, and present a physical explanation of both of these states and the stability of the polarization locked vector solitons. (C) 2000 American Institute of Physics. [S1054-1500(00)00103-8]. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Lucent Technol, Bell Labs, Holmdel, NJ 07733 USA. Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. RP Cundiff, ST (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Cundiff, Steven/B-4974-2009 OI Cundiff, Steven/0000-0002-7119-5197 NR 35 TC 8 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD SEP PY 2000 VL 10 IS 3 BP 613 EP 624 AR PII [S1054-1500(00)00103-8] DI 10.1063/1.1286246 PG 12 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 352BK UT WOS:000089194500013 ER PT J AU Roberson, SV AF Roberson, SV TI The dividends of hard work SO CHEMICAL INNOVATION LA English DT Editorial Material C1 NIST, Analyt Microscopy Grp, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Roberson, SV (reprint author), NIST, Analyt Microscopy Grp, Surface & Microanal Sci Div, 100 Bur Dr,Stop 8371, Gaithersburg, MD 20899 USA. EM roberson@nist.gov NR 2 TC 3 Z9 3 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1527-4799 J9 CHEM INNOV JI Chem. Innov. PD SEP PY 2000 VL 30 IS 9 BP 3 EP 4 PG 2 WC Chemistry, Applied SC Chemistry GA 349PW UT WOS:000089055700002 ER PT J AU Hewes, JD AF Hewes, JD TI High throughput methodologies: A new paradigm for chemicals and materials research SO CHIMICA OGGI-CHEMISTRY TODAY LA English DT Article AB A new paradigm is now taking hold in the research and development (R&D) centers of Japanese, European and U.S. advanced materials industries (catalysts, polymers, specialty and fine chemicals, optical materials, and electronic materials). High throughput methods for materials R&D are leveraging the combinatorial chemistry methodologies developed over the past ten years in the pharmaceutical industry. The implementation of this emerging methodology by materials innovators will enable new technologies having broad technological and economic impact. The commercial implication for high throughput methods will be more complex compositions created and analyzed in a reduced cycle time and at lower cost. The implication for basic research will be in elucidating new phenomena and in the development of new technology platforms. C1 Natl Inst Stand & Technol, US Dept Commerce,Technol Adm, Adv Technol Program, Chem & Life Sci Off, Gaithersburg, MD 20899 USA. NR 7 TC 3 Z9 3 U1 1 U2 2 PU TEKNOSCIENZE PUBL PI MILAN PA VIA AURELIO SAFFI 23, 20123 MILAN, ITALY SN 0392-839X J9 CHIM OGGI JI Chim. Oggi-Chem. Today PD SEP PY 2000 VL 18 IS 9 BP 20 EP 24 PG 5 WC Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary SC Biotechnology & Applied Microbiology; Chemistry GA 363YK UT WOS:000089865100003 ER PT J AU Delworth, TL Mann, ME AF Delworth, TL Mann, ME TI Observed and simulated multidecadal variability in the Northern Hemisphere SO CLIMATE DYNAMICS LA English DT Article ID OCEAN-ATMOSPHERE MODEL; SURFACE-TEMPERATURE; THERMOHALINE CIRCULATION; INTERDECADAL VARIABILITY; ATLANTIC OSCILLATION; CLIMATE OSCILLATIONS; TRANSIENT RESPONSES; SOLAR-RADIATION; GRADUAL CHANGES; GLOBAL CLIMATE AB Analyses of proxy based reconstructions of surface temperatures during the past 330 years show the existence of a distinct oscillatory mode of variability with an approximate time scale of 70 years. This variability is also seen in instrumental records, although the oscillatory nature of the variability is difficult to assess due to the short length of the instrumental record. The spatial pattern of this variability is hemispheric or perhaps even global in scale, but with particular emphasis on the Atlantic region. Independent analyses of multi century integrations of two versions of the GFDL coupled atmosphere-ocean model also show the existence of distinct multidecadal variability in the North Atlantic region which resembles the observed pattern. The model variability involves fluctuations in the intensity of the thermohaline circulation in the North Atlantic. It is our intent here to provide a direct comparison of the observed variability to that simulated in a coupled ocean-atmosphere model, making use of both existing instrumental analyses and newly available proxy based multi-century surface temperature estimates. The analyses demonstrate a substantial agreement between the simulated and observed patterns of multidecadal variability in sea surface temperature (SST) over the North Atlantic. There is much less agreement between the model and observations for sea level pressure. Seasonal analyses of the variability demonstrate that for both the model and observations SST appears to be the primary carrier of the multidecadal signal. C1 Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. RP Delworth, TL (reprint author), Geophys Fluid Dynam Lab, Route 1,Forrestal Campus, Princeton, NJ 08542 USA. RI Delworth, Thomas/C-5191-2014; Mann, Michael/B-8472-2017 OI Mann, Michael/0000-0003-3067-296X NR 52 TC 625 Z9 644 U1 4 U2 67 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD SEP PY 2000 VL 16 IS 9 BP 661 EP 676 DI 10.1007/s003820000075 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353ZA UT WOS:000089304300002 ER PT J AU Raviv, D AF Raviv, D TI The visual looming navigation cue: A unified approach SO COMPUTER VISION AND IMAGE UNDERSTANDING LA English DT Article ID TIME-TO-COLLISION; AUTONOMOUS NAVIGATION; DEPTH; FOCUS; FLOW; FIXATION; CAMERA; SHAPE AB Visual looming is related to an increasing projected size of an object on a viewer's retina as the relative distance between the viewer and the object decreases. It is an indication for threat that may be used along with visual fixation to accomplish navigation tasks. This paper defines visual looming as the time derivative of the relative distance (range) between the observer and the object divided by the relative distance itself. It introduces a unified approach to visual looming by showing how visual looming can be calculated from the relative temporal change in the following attributes of a 2D image sequence: (i) image area, (ii) image brightness, (iii) texture density in the image, and (iv) image blur, It is shown that a closed-form unified expression can be adopted in all these methods. Experimental results illustrate how the measured values of looming are related to the actual values. Finally, looming is used in the sense of a threat of collision, along with visual fixation, to navigate in an unknown environment, (C) 2000 Academic Press. C1 Florida Atlantic Univ, Dept Elect Engn, Boca Raton, FL 33431 USA. Florida Atlantic Univ, Robot Ctr, Boca Raton, FL 33431 USA. Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Florida Atlantic Univ, Dept Elect Engn, Boca Raton, FL 33431 USA. EM ravivd@fau.edu NR 46 TC 2 Z9 2 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3142 EI 1090-235X J9 COMPUT VIS IMAGE UND JI Comput. Vis. Image Underst. PD SEP PY 2000 VL 79 IS 3 BP 331 EP 363 DI 10.1006/cviu.2000.0862 PG 33 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 353XA UT WOS:000089299700001 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI Determining the determinant SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. IDA, Ctr Comp Sci, Bowie, MD 20715 USA. RP Beichl, I (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2000 VL 2 IS 5 BP 63 EP 66 PG 4 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 353PD UT WOS:000089283900011 ER PT J AU Xu, HHK Eichmiller, FC Antonucci, JM Schumacher, GE Ives, LK AF Xu, HHK Eichmiller, FC Antonucci, JM Schumacher, GE Ives, LK TI Dental resin composites containing ceramic whiskers and precured glass ionomer particles SO DENTAL MATERIALS LA English DT Article DE ceramic whisker; glass ionomer; reinforcement; resin composite; strength; fluoride ID TERM FLUORIDE RELEASE; MECHANICAL-PROPERTIES; FRACTURE-TOUGHNESS; FIBER COMPOSITES; SILICON-NITRIDE; CEMENTS; RESTORATIONS; INVITRO; DAMAGE; SHRINKAGE AB Objectives: Glass ionomer, resin-modified glass ionomer, and compomer materials are susceptible to brittle fracture and are inadequate for use in large stress-bearing posterior restorations. The aim of this study was to use ceramic single crystal whiskers to reinforce composites formulated with precured glass ionomer, and to examine the effects of whisker-to-precured glass ionomer mass ratio on mechanical properties, fluoride release, and polishability of the composites. Methods: Silica particles were fused onto silicon nitride whiskers to facilitate silanization and to improve whisker retention in the matrix. Hardened glass ionomer was ground into a fine powder, mixed with whiskers, and used as fillers for a dental resin. Four control materials were also tested: a glass ionomer, a resin-modified glass ionomer, a compomer, and a hybrid composite. A three-point flexural test was used to measure flexural strength, modulus, and work-of-fracture. A fluoride ion-selective electrode was used to measure fluoride release. Composite surfaces polished simulating clinical procedures were examined by SEM and profilometry. Results: At whisker/(whisker + precured glass ionomer) mass fractions of 1.0 and 0.91, the whisker composite had a flexural strength in MPa (mean (SD); n = 6) of (196 (10)) and (150 (16)), respectively, compared to (15 (7)) for glass ionomer, (39 (8)) for resin-modified glass ionomer, (89 (18)) for compomer, and (120 (16)) for hybrid composite. The whisker composite had a cumulative fluoride release of nearly 20% of that of the glass ionomer after 90 days. The whisker composites had surface roughness comparable to the hybrid resin composite. Significance: Composites filled with precured glass ionomer particles and whiskers exhibit moderate fluoride release with improved mechanical properties; the whisker-to-glass ionomer ratio is a key microstructural parameter that controls fluoride release and mechanical properties. Published by Elsevier Science Ltd on behalf of Academy of Dental Materials. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [R29 DE12476, P 50 DE09322] NR 51 TC 30 Z9 32 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0109-5641 J9 DENT MATER JI Dent. Mater. PD SEP PY 2000 VL 16 IS 5 BP 356 EP 363 DI 10.1016/S0109-5641(00)00028-2 PG 8 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA 343RE UT WOS:000088714700006 PM 10915897 ER PT J AU Sherman, K AF Sherman, K TI Why regional coastal monitoring for assessment of ecosystem health? SO ECOSYSTEM HEALTH LA English DT Article ID ZOOPLANKTON; MANAGEMENT; FISHERIES; NORTHEAST; ATLANTIC AB During recent years, the public and the scientific communities have signaled concern over growing degradation of ecosystem health, depleted fisheries, pollution, and habitat loss. Public concern has been registered in newspapers, electronic media, and congressional actions. Scientific concern has moved from the pages of journals to the actions of professional societies, as for example the Sustainable Biosphere Initiative of the Ecological Society of America (Lubchenco et al. 1991). Responsive actions at the national and international levels have resulted in Conventions and Protocols on Climate Change, Biodiversity, Ozone, and internationally recognized declarations for sustaining marine fisheries. C1 USDOC, NOAA, NMFS, Narragansett Lab, Narragansett, RI 02882 USA. RP Sherman, K (reprint author), USDOC, NOAA, NMFS, Narragansett Lab, 28 Tarzwell Dr, Narragansett, RI 02882 USA. NR 70 TC 7 Z9 8 U1 2 U2 5 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1076-2825 J9 ECOSYST HEALTH JI Ecosyst. Health PD SEP PY 2000 VL 6 IS 3 BP 205 EP 216 DI 10.1046/j.1526-0992.2000.006003205.x PG 12 WC Ecology; Environmental Studies SC Environmental Sciences & Ecology GA 410EF UT WOS:000167426500004 ER PT J AU Long, ER AF Long, ER TI Spatial extent of sediment toxicity in US estuaries and marine bays SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article; Proceedings Paper CT 4th Symposium on the Environmental Monitoring and Assessment Program (EMAP) CY APR 06-08, 1999 CL SAN FRANCISCO, CALIFORNIA DE sediment quality; estuaries; sediment contamination; sediment toxicity; benthic resources; toxicity tests ID INFAUNAL COMMUNITY COMPOSITION; SAN-FRANCISCO BAY; QUALITY TRIAD; CONTAMINATION; ECOSYSTEMS AB Acute, laboratory toxicity tests were performed by the National Oceanic and Atmospheric Administration (NOAA) on 1543 surficial sediment samples collected during 1991 through 1997 throughout 25 estuaries and marine bays. Selected areas were sampled along the Atlantic, Gulf of Mexico, and Pacific coasts. The toxicity of each sample was determined with 10-day amphipod survival tests performed with solid-phase (bulk) sediments. Collectively, the 1543 samples tested through 1997 represented a total area of approximately 7300 km(2). Toxicity was observed with the amphipod survival tests in samples that represented approximately 6% of the combined area. Using similar tests conducted on samples collected in different: but overlapping, study areas, the U.S. Environmental Protection Agency (EPA) estimated that approximately 7% of the combined estuarine area sampled was toxic. Generally, toxicity was most severe in northeastern and southwestern estuaries and least prevalent in southeastern and northwestern areas. However, considerable portions of the Pacific coast have not been tested with the same methods. In tests of CYP1A enzyme induction (n = 464), samples were toxic that represented about 5% of the combined study areas. Toxicity was much more widespread, however, when the results of two sub-lethal tests were analyzed. Significant results occurred in samples that represented approximately 25% and 39% of the study areas in tests of sea urchin fertilization (n = 1309) and microbial bioluminescence (n = 1215),respectively. C1 Natl Ocean Serv, Natl Ocean & Atmospher Adm, Natl Ctr Coastal Ocean Sci, Seattle, WA 98115 USA. RP Long, ER (reprint author), Natl Ocean Serv, Natl Ocean & Atmospher Adm, Natl Ctr Coastal Ocean Sci, 7600 Sand Pt Way NE, Seattle, WA 98115 USA. NR 37 TC 29 Z9 31 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD SEP PY 2000 VL 64 IS 1 BP 391 EP 407 DI 10.1023/A:1006407621853 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA 352XL UT WOS:000089244600030 ER PT J AU Mulholland, GW Croarkin, C AF Mulholland, GW Croarkin, C TI Specific extinction coefficient of flame generated smoke SO FIRE AND MATERIALS LA English DT Article ID OPTICAL-PROPERTIES; DIFFUSION FLAMES; FUELS AB The experimental results for the mass specific extinction coefficient (sigma (s)) at lambda = 633 nm for flame generated smoke are summarized for seven studies involving 29 fuels. The measurements are for post-flame smoke generated by overventilated burning, From an analysis of variance for the seven studies, it was found that between-laboratory differences were the major source of variability. The estimated mean value of sigma (s) is 8.7 m(2)/g with an expanded uncertainty (95% confidence interval) of 1.1 m(2)/g. A major implication of this nearly universal value is that one can infer mass concentration of smoke by making light extinction measurements. Published in 2000 by John Wiley & Sons Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Mulholland, GW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 29 Z9 29 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD SEP-OCT PY 2000 VL 24 IS 5 BP 227 EP 230 DI 10.1002/1099-1018(200009/10)24:5<227::AID-FAM742>3.0.CO;2-9 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 376FN UT WOS:000165447700003 ER PT J AU Mulholland, GW Johnson, EL Fernandez, MG Shear, DA AF Mulholland, GW Johnson, EL Fernandez, MG Shear, DA TI Design and testing of a new smoke concentration meter SO FIRE AND MATERIALS LA English DT Article ID TURBULENT-DIFFUSION FLAMES; MODEL AB The design of a new smoke concentration meter based on light-extinction measurements with a He-Ne laser is described. The measurement allows the determination of the mass-generation rate of smoke and smoke yield during a fire test with little more time or labour than is required for performing heat-release-rate and mass-loss-rate measurements, The new smoke concentration meter was motivated by the finding from several studies of a nearly universal value of the specific extinction coefficient of post-flame smoke produced by over ventilated fires, Key design features include the use of a stabilized laser, purge flow to eliminate smoke deposition on the optics, U channel construction to minimize the effect of heating on the optical alignment and beam correction optics. The facility was fabricated almost entirely from commercially available components to allow this design to be easily reproduced by fire research and testing laboratories. The smoke concentration meter was able to measure a smoke yield as small as 0.005 for a propane fire to as large as 0.10 for a toluene pool fire. A detailed uncertainty assessment was made, The result for a 50 cm diameter heptane pool fire agrees well with previous smoke yield measurements made for the same fuel and pool diameter based on filter collection and weighing, Copyright (C) 2000 John Wiley & Sons Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. MIT, Cambridge, MA 02139 USA. RP Mulholland, GW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 31 TC 9 Z9 11 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD SEP-OCT PY 2000 VL 24 IS 5 BP 231 EP 243 DI 10.1002/1099-1018(200009/10)24:5<231::AID-FAM743>3.3.CO;2-E PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 376FN UT WOS:000165447700004 ER PT J AU Parrish, RH Schwing, FB Mendelssohn, R AF Parrish, RH Schwing, FB Mendelssohn, R TI Mid-latitude wind stress: the energy source for climatic shifts in the North Pacific Ocean SO FISHERIES OCEANOGRAPHY LA English DT Article DE North Pacific; regime shift; SST; sustainable fisheries; wind stress ID SEA-SURFACE TEMPERATURE; INTERANNUAL VARIABILITY; CALIFORNIA CURRENT; SALMON PRODUCTION; WEST-COAST; HEAT-FLUX; EL-NINO; AMERICA; CIRCULATION; ANOMALIES AB Analyses of atmospheric observations in the North Pacific demonstrate extensive decadal-scale variations in the mid-latitude winter surface wind stress. In the decade after 1976 winter, eastward wind stress doubled over a broad area in the central North Pacific and the winter zero wind stress curl line was displaced about 6 degrees southward. This resulted in increased southward Ekman transport, increased oceanic upwelling, and increased turbulent mixing as well as a southward expansion of the area of surface divergence. All these factors contributed to a decadal winter cold anomaly along the subtropical side of the North Pacific Current. In summer the cold anomaly extended eastward, almost reaching the coast of Oregon. The increased gradient in wind stress curl and southward displacement of the zero curl line also resulted in an increase in total North Pacific Current transport, primarily on the Equator side of this Current. Thus, surface water entering the California Current was of more subtropical origin in the post-1976 decade. Southward (upwelling favourable) wind stress and sea surface temperature (SST) in the area off San Francisco exhibit at least three different types of decadal departures from mean conditions. In association with the 1976 climatic shift, marine fishery production in the Oyashio, California and Alaska Currents altered dramatically, suggesting that these natural environmental variations significantly alter the long-term yields of major North Pacific fisheries. C1 Natl Marine Fisheries Serv, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. RP Parrish, RH (reprint author), Natl Marine Fisheries Serv, Pacific Fisheries Environm Lab, 1352 Lighthouse Ave, Pacific Grove, CA 93950 USA. NR 58 TC 50 Z9 51 U1 1 U2 8 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD SEP PY 2000 VL 9 IS 3 BP 224 EP 238 PG 15 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 355RY UT WOS:000089400500003 ER PT J AU Fahey, DW Gao, RS Del Negro, LA Keim, ER Kawa, SR Salawitch, RJ Wennberg, PO Hanisco, TF Lanzendorf, EJ Perkins, KK Lloyd, SA Swartz, WH Proffitt, MH Margitan, JJ Wilson, JC Stimpfle, RM Cohen, RC McElroy, CT Webster, CR Loewenstein, M Elkins, JW Bui, TP AF Fahey, DW Gao, RS Del Negro, LA Keim, ER Kawa, SR Salawitch, RJ Wennberg, PO Hanisco, TF Lanzendorf, EJ Perkins, KK Lloyd, SA Swartz, WH Proffitt, MH Margitan, JJ Wilson, JC Stimpfle, RM Cohen, RC McElroy, CT Webster, CR Loewenstein, M Elkins, JW Bui, TP TI Ozone destruction and production rates between spring and autumn in the Arctic stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUMMER; PHOTOCHEMISTRY; NITROGEN; POLARIS; NO2; O-3; RADICALS; REGION; CLO AB In situ measurements of radical and long-lived species were made in the lower Arctic stratosphere (18 to 20 km) between spring and early autumn in 1997. The measurements include O-3, ClO, OH, HO2, NO, NO2, N2O, CO, and overhead O-3 A photochemical box model constrained by these and other observations is used to compute the diurnally averaged destruction and production rates of O-3 in this region. The rates show a strong dependence on solar exposure and ambient O-3. Total destruction rates, which reach 19%/month in summer, reveal the predominant role of NOx and HOx catalytic cycles throughout the period. Production of O-3 is significant only in midsummer air parcels. A comparison of observed O-3 changes with destruction rates and transport effects indicates the predominant role of destruction in spring and an increased role of transport by early autumn. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Aerospace Corp, Los Angeles, CA 90009 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20723 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. Atmospher Environm Serv, Downsview, ON, Canada. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fahey, DW (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012; Swartz, William/A-1965-2010; Kawa, Stephan/E-9040-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; Swartz, William/0000-0002-9172-7189; Fahey, David/0000-0003-1720-0634 NR 21 TC 15 Z9 15 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2000 VL 27 IS 17 BP 2605 EP 2608 DI 10.1029/2000GL011404 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353BW UT WOS:000089254700005 ER PT J AU Ferraro, RR Weng, FH Grody, NC Zhao, LM AF Ferraro, RR Weng, FH Grody, NC Zhao, LM TI Precipitation characteristics over land from the NOAA-15 AMSU sensor SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MICROWAVE IMAGER; RAINFALL AB Window channel measurements from the NOAA-15 Advanced Microwave Sounding Unit (AMSU) are used to retrieve rain rates. This study focuses on the rain rate retrievals over land and uses measurements at 89 and 150 GHz to detect a scattering signal by millimeter-sized ice particles under precipitating atmospheres. An operational algorithm using the AMSU-A module (89 GHz) implemented in August 1999 is also described. The algorithms are calibrated with hourly surface rain observations. It is shown that identification of stratiform rain can be dramatically improved using measurements at 150 GHz from the AMSU-B sensor. Improved spatial resolution of AMSU-B is a major factor contributing to this algorithm. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. QSS Grp Inc, Lanham, MD USA. RP Ferraro, RR (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd,Room 601, Camp Springs, MD 20746 USA. RI Ferraro, Ralph/F-5587-2010; Weng, Fuzhong/F-5633-2010 OI Ferraro, Ralph/0000-0002-8393-7135; Weng, Fuzhong/0000-0003-0150-2179 NR 9 TC 59 Z9 62 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2000 VL 27 IS 17 BP 2669 EP 2672 DI 10.1029/2000GL011665 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353BW UT WOS:000089254700021 ER PT J AU Xue, Y Leetmaa, A AF Xue, Y Leetmaa, A TI Forecasts of tropical Pacific SST and sea level using a Markov model SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NINO SOUTHERN-OSCILLATION; 1997-98 EL-NINO; VARIABILITY; PREDICTION; CYCLES; ONSET AB A seasonally varying Markov model is constructed in a multivariate EOF space of observed SST and sea level analysis for 1981-98. The hindcast skill of SST and sea level is estimated with a cross-validation scheme. For SST, the correlation skill is highest in the central-eastern equatorial Pacific at about 0.5 at 9 month lead. The Markov model has a marginal SST forecast skill at 3 month lead (> 0.4) in the north-western Pacific (NWP) around 10 degrees N. For sea level, the correlation skill is highest in the central equatorial Pacific and the NWP around 10 degrees N at above 0.5 at 9 month lead. In the western Pacific, sea level anomalies are generally more predictable than SST anomalies. The real time forecast of sea level by the Markov model is available at the official web site of the Climate Prediction Center, NOAA (http://www.cpc.ncep.noaa.gov/pacdir). C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC USA. Res Data Syst Corp, Greenbelt, MD USA. RP Xue, Y (reprint author), NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC USA. NR 11 TC 14 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2000 VL 27 IS 17 BP 2701 EP 2704 DI 10.1029/1999GL011107 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353BW UT WOS:000089254700029 ER PT J AU Burnett, WH Kamenkovich, VM Jaffe, DA Gordon, AL Mellor, GL AF Burnett, WH Kamenkovich, VM Jaffe, DA Gordon, AL Mellor, GL TI Dynamical balance in the Indonesian Seas circulation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID THROUGHFLOW AB A high resolution, four-open port, non-linear, barotropic ocean model (2D POM) is used to analyze the Indonesian Seas circulation. Both local and overall momentum balances are studied. It is shown that geostrophy holds over most of the area and that the Pacific-Indian Ocean pressure difference is essentially balanced by the resultant of pressure forces acting on the bottom. C1 Naval Meteorol & Oceanog Command, Stennis Space Ctr, MS USA. Univ So Mississippi, Dept Marine Sci, Stennis Space Ctr, MS USA. Univ Calif Irvine, Irvine, CA USA. Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Burnett, WH (reprint author), Naval Meteorol & Oceanog Command, Stennis Space Ctr, MS USA. RI Gordon, Arnold/H-1049-2011 OI Gordon, Arnold/0000-0001-6480-6095 NR 7 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2000 VL 27 IS 17 BP 2705 EP 2708 DI 10.1029/2000GL011494 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353BW UT WOS:000089254700030 ER PT J AU Lee, K Wanninkhof, R Feely, RA Millero, FJ Peng, TH AF Lee, K Wanninkhof, R Feely, RA Millero, FJ Peng, TH TI Global relationships of total inorganic carbon with temperature and nitrate in surface seawater SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID EASTERN EQUATORIAL PACIFIC; EL-NINO; ATMOSPHERIC CO2; PARTIAL-PRESSURE; DIOXIDE ANALYSIS; ATLANTIC-OCEAN; MARINE; DISSOCIATION; VARIABILITY; CONSTANTS AB High quality total inorganic carbon (C-T) measurements made in the major ocean basins as part of the Joint Global Ocean Flux Study (JGOFS), the National Oceanic and Atmospheric Administration/Ocean Atmosphere Carbon Exchange Study (NOAA/OACES), and the Department of Energy/World Ocean Circulation Experiment (DOE/WOCE) programs are related to sea surface temperature (SST) and nitrate (NO3-). A simple two-parameter function with SST and NO3- of the form NCT = a + b SST + c SST2 + d NO3- fits salinity (S)-normalized surface C-T(NCT = C-T x 35/S) data for different parts of the oceans within an area-weighted error of +/-7 mu mol kg(-1) (1 sigma). Estimated values of NCT using the derived algorithms with NO3- and SST are compared with values calculated from the surface partial pressure of CO2 (pCO(2SW)) [Takahashi et al., 1997] and total alkalinity (A(T)) [Millero et at, 1998] fields using thermodynamic models. Comparisons of the estimated values of NCT with measurements not used to derive the same algorithms, and comparisons with the values calculated from global A(T) and pCO(2SW) fields, give a realistic uncertainty of +/-15 mu mol kg(-1) in estimated C-T The derived correlations of NCT with SST and NO3- presented here make it possible to estimate surface C-T over the ocean from climatological SST, S, and N-3(-) fields. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MAC, Miami, FL 33149 USA. Univ Miami, CIMAS, Rosenstiel Sch Marine & Atmospher Sci, Coral Gables, FL 33124 USA. RP Lee, K (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Lee, Kitack/G-7184-2015 NR 45 TC 39 Z9 40 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP PY 2000 VL 14 IS 3 BP 979 EP 994 DI 10.1029/1998GB001087 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 350EZ UT WOS:000089089000019 ER PT J AU Bass, AL Witzell, WN AF Bass, AL Witzell, WN TI Demographic composition of immature green turtles (Chelonia mydas) from the east central Florida coast: Evidence from mtDNA markers SO HERPETOLOGICA LA English DT Article DE foraging population; mixed-stock analysis; migration; life history; neritic environment ID SEA-TURTLES; MIGRATIONS; POPULATION; ISLAND; LAGOON; TESTS; CHI-2 AB Green turtles are highly migratory and difficult to study in aquatic habitats. Despite much progress in recent decades, some aspects of the green turtle's life history remain obscure. Long distance migrations by adults between foraging grounds and nesting habitats are striking, yet juvenile movements are poorly known. We performed mixed-stock analysis using mtDNA markers on a foraging population of juvenile green sea. turtles, Chelonia mydas, from Hutchinson Island, Florida, to determine the origin of these animals. The results indicate that contributions to this population from previously surveyed nesting populations were 53% from Costa Rica, 42% from the United States and Mexico, and 4% from Aves Island (Venezuela) and Surinam. Results differed significantly from a similar juvenile foraging population in the nearby Bahamas (Costa Rica: 80%; United States and Mexico: 5%; Aves Island and Surinam: 14%; Ascension Island and Guinea Bissau: 1%). This difference may be due to a number of factors resulting in geographic or temporal changes in haplotype composition. Results of this study reinforce the need for cooperative international management of migratory species. C1 Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. US Dept Commerce, NOAA, Natl Marine Fisheries Serv, Miami Lab, Miami, FL 33149 USA. RP Bass, AL (reprint author), Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. NR 50 TC 47 Z9 51 U1 1 U2 6 PU HERPETOLOGISTS LEAGUE PI EMPORIA PA EMPORIA STATE UNIV, DIVISION BIOLOGICAL SCIENCES, 1200 COMMERCIAL ST, EMPORIA, KS 66801-5087 USA SN 0018-0831 J9 HERPETOLOGICA JI Herpetologica PD SEP PY 2000 VL 56 IS 3 BP 357 EP 367 PG 11 WC Zoology SC Zoology GA 359NA UT WOS:000089615900008 ER PT J AU Dudley, DG Pao, HY Hill, DA AF Dudley, DG Pao, HY Hill, DA TI Special issue - In memoriam: James R. Wait - Introduction SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Editorial Material C1 US Dept Commerce, NIST, Boulder, CO 80303 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NIST, Radio Frequency Technol Div, Boulder, CO 80305 USA. RP Dudley, DG (reprint author), US Dept Commerce, NIST, 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 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2000 VL 48 IS 9 BP 1287 EP 1288 DI 10.1109/TAP.2000.898759 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QQ UT WOS:000166824200003 ER PT J AU Wait, JR Hill, DA AF Wait, JR Hill, DA TI Ground wave of an idealized lightning return stroke SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE ground wave; height-gain function; lightning return stroke; Sommerfeld integral; vertical electric dipole ID FIELDS AB We model a lightning return stroke by a vertical traveling wave of current with a complex propagation constant. The Sommerfeld-integral analysis is similar to that of a vertical electric dipole over a lossy earth except that the source is distributed in height. When the integration over the source current is performed analytically, an extra term appears in addition to the classical Sommerfeld attenuation function. This term is a result of the height-gain function of the distributed source due to an effective elevated height of the source dipole moment, In most cases of interest, the extra term is small and the height-gain function is not much larger than one. The results have application to remote sensing of lightning from a ground-based observer. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. NR 13 TC 4 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2000 VL 48 IS 9 BP 1349 EP 1353 DI 10.1109/8.898767 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QQ UT WOS:000166824200011 ER PT J AU Holloway, CL Hill, DA Dalke, RA Hufford, GA AF Holloway, CL Hill, DA Dalke, RA Hufford, GA TI Radio wave propagation characteristics in lossy circular waveguides such as tunnels, mine shafts, and boreholes SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE circular waveguides; geologic measurement; mining industry ID MICROWAVE DIELECTRIC BEHAVIOR; WET SOIL; MODELS AB In this paper, we present the characteristics of radio propagation in a circular lossy waveguide whose walls are composed of earth soil materials with frequency-dependent properties. This type of structure is used to represent a radio link for an underground wireless communication channel such as a tunnel, mine shaft, or borehole. We present calculated results of the attenuation constant for various propagation modes in the soil waveguide structure for various soil constituents and moisture levels. Transverse field plots of the various modes for different soil types are also presented. Finally, it is shown that for small \k(2)a\ (where k(2) is the wavenumber in the soil and a is the radius of the waveguide) some modes in the waveguide disappear and a discussion of this behavior and how it relates to excitation problems is given. C1 US Dept Commerce, Inst Telecommun Sci, Boulder Labs, Boulder, CO 80303 USA. Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder Labs, Boulder, CO 80303 USA. RP Holloway, CL (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder Labs, 325 Broadway, Boulder, CO 80303 USA. NR 37 TC 42 Z9 44 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2000 VL 48 IS 9 BP 1354 EP 1366 DI 10.1109/8.898768 PG 13 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QQ UT WOS:000166824200012 ER PT J AU Hsu, CC Indeck, RS Jander, A Muller, MW Ross, CA Twisselmann, DJ AF Hsu, CC Indeck, RS Jander, A Muller, MW Ross, CA Twisselmann, DJ TI MFM observation of magnetization reversal process in recording media with lithographically defined texture SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE magnetic recording; MFM; magnetization reversal; texture ID THIN-FILM MEDIA; ORIENTATION; ANISOTROPY AB Periodically textured magnetic recording media with different groove depths are investigated. A spatial map of variation in the switching field and switching field distribution are derived From a series of MFM images. When the reversing field is applied along the texture, long chains of reversal are formed and channeled by the texture grooves. Most grains switch within a relatively small range of applied fields. For fields applied transverse to the texture, short chains of reversal Form along the textured grooves, and switching occurs over a broader applied field range. C1 Washington Univ, Magnet & Informat Sci Ctr, St Louis, MO 63130 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RP Hsu, CC (reprint author), Washington Univ, Magnet & Informat Sci Ctr, St Louis, MO 63130 USA. NR 7 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2327 EP 2329 DI 10.1109/20.908418 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700060 ER PT J AU Russek, SE Kaka, S AF Russek, SE Kaka, S TI Time and frequency domain measurements of ferromagnetic resonance in small spin-valve SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE FMR; GMR; magnetic device dynamics; MRAM; spin-valve ID DEVICES AB Time and frequency domain magnetoresistance measurements of ferromagnetic resonance (FMR) in small spin-valve devices are presented along with comparisons to single-domain simulations. The measurements and simulations give consistent results for rotational motion with angular deviations of less than 30 degrees from the easy axis, White the time and frequency domain measurements produce similar results for ideal devices in the linear regime, each technique provides different information as the devices become nonlinear and less ideal. Both time and frequency domain magnetoresistance measurements allow the study of FMR in considerably smaller magnetic structures than can be done with conventional techniques. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Russek, SE (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 15 Z9 15 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2560 EP 2562 DI 10.1109/20.908509 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700133 ER PT J AU Gafron, TJ Burkett, SL Russek, SE AF Gafron, TJ Burkett, SL Russek, SE TI Current density limitations of spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE current density; lifetime; magnetoresistance; spin valves AB As spin valve technology evolves, understanding the limitations and design constraints is a critical consideration. Choosing the correct materials combination, aspect ratio and size depends upon careful device characterization. Analysis of spin valves in this study shows that device lifetime and durability are determined by allowable current densities and the internal temperatures that result. Parameters such as maximum sustained current and device degradation can be predicted and calculated, allowing the designer to choose the correct parameters for a specific application. C1 Boise State Univ, Dept Elect Engn, Boise, ID 83725 USA. Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Gafron, TJ (reprint author), Boise State Univ, Dept Elect Engn, Boise, ID 83725 USA. NR 6 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2611 EP 2613 DI 10.1109/20.908532 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700150 ER PT J AU Bae, S Egelhoff, WF Chen, PJ Judy, JH AF Bae, S Egelhoff, WF Chen, PJ Judy, JH TI Structural and microscopic analyses of (alpha-Fe2O3/Co(NiFe)/Cu/Co(NiFe) bottom GMR spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE crystal structure; surface roughness; Ni-Cu intermixing; alpha-Fe2O3 based GMR spin valve AB The structural and microscopic analyses of Si/alpha -Fe2O3/Co(NiFe)/Cu/Co(NiFe) bottom GMR spin valves with Co or NiFe free and pinned layers were performed from the point of view of material characteristics. The input sputtering power, substrate bias, and sputtering power source (RF; or DC magnetron) were used as experimental variables. It was confirmed that the crystal structure of alpha -Fe2O3 related to the anti-ferromagnetic crystalline anisotropy, the surface roughness associated with coupling field(bias field) between the free and the pinned layers through the nonmagnetic Cu layer, and the inter-diffusion were crucial factors in determining the GMR performance of Si/alpha -Fe2O3/Co(NiFe)/Cu/Co(NiFe). The increase of Ni-Cu intermixing region due to the Cu inter-diffusion was shown to be a much more dominant factor as compared to the interfacial surface roughness in reduction of GMR ratio in alpha -Fe2O3 bottom spin valve. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NIST, Magnet Mat Grp, Gaithersburg, MD 20899 USA. RP Bae, S (reprint author), Univ Minnesota, Dept Elect & Comp Engn, 200 Union St SE, Minneapolis, MN 55455 USA. NR 5 TC 1 Z9 1 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2617 EP 2619 DI 10.1109/20.908534 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700152 ER PT J AU Bae, S Egelhoff, WF Chen, PJ Judy, JH AF Bae, S Egelhoff, WF Chen, PJ Judy, JH TI Effects of deposition process parameters on exchange coupling of alpha-Fe2O3/NiFe Bi-layers and GMR of alpha-Fe2O3/NiFe/Cu/NiFe spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE alpha-Fe2O3 based GMR; alpha-Fe2O3/NiFe bi-layer; deposition parameters; exchange coupling AB Effects of deposition process parameters on the exchange coupling of alpha -Fe2O3/NiFe bi-layers acid GMR characteristics of alpha -Fe2O3/NiFe/Cu/NiFe spin-valves using optimized anti-ferromagnetic alpha -Fe2O3 layer have been investigated. The exchange bias field was increased in alpha -Fe2O3(50 nm)/ NiFe (7 nm) bi-layers by increasing oxygen partial pressure to 14.7%, substrate bias to 125 V, and input sputtering power up to 800 W of RF reactively sputtered alpha -Fe2O3 films, The thickness of NiFe and alpha -Fe2O3 layers also had an influence on the exchange coupling characteristics. By decreasing NiFe thickness from 35 nm to 5 nm and increasing alpha -Fe2O3 thickness from 5-50 nm, the exchange bias field dramatically increased up to 62.5 Oe, However, in the alpha -Fe2O3 thickness range of 50-100 nm, the exchange bias field decreased from 62.5 to 21.5 Oe, The GMR performance of as-deposited Si/ alpha -Fe2O3(50 nm)/NiFe(3.25 nm)/Cu(2 nm)/ NiFe(3.25 nm)/ Au (5.4 nm) spin valve structures was characterized. The GMR ratio and MR sensitivity was 5.2% and 0.6%/Oe, respectively. C1 Univ Minnesota, MINT, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NIST, Magnet Mat Grp, Gaithersburg, MD 20899 USA. RP Bae, S (reprint author), Univ Minnesota, MINT, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NR 7 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2892 EP 2895 DI 10.1109/20.908619 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700233 ER PT J AU Russek, SE Bailey, WE AF Russek, SE Bailey, WE TI Magnetic domain structure and imaging of Co-Pt multilayer thin-film nanostructures SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE CoPt; magnetic imaging reference samples; MFM; patterned media ID FORCE MICROSCOPY; TIPS AB Dots, with diameters of 100 nm and 220 nm, have been fabricated from (CoxPt0.8nm)(25) multilayer structures, where the Co thickness a: was varied from 0.2 nm to 0.45 nm, The unpatterned films show perpendicular anisotropy with perpendicular coercive fields of 20 kA/m to 100 kA/m, The patterned structures show a transition from multidomain to single domain behavior as the dot dimension is reduced from 220 nm to 100 nm, The remanent hysteresis loops of the 100 nm dots were measured using magnetic force microscopy (MFM) and compared to remanent hysteresis loops of the unpatterned films. MFM line scans of the 100 nm dots were compared to calculations of the field gradients expected above uniformly magnetized dots. The calculations indicate that narrow features in the magnetic field gradients should be observed near the edges of the dots and that these samples may be of use as a magnetic imaging resolution standard. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Russek, SE (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 8 TC 12 Z9 12 U1 0 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2990 EP 2992 DI 10.1109/20.908651 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700264 ER PT J AU Kabos, P Kaka, S Russek, SE Silva, TJ AF Kabos, P Kaka, S Russek, SE Silva, TJ TI Metastable states in large angle magnetization rotations SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE small particles; spin valves; switching; spin dynamics and relaxation; magnetocrystalline anisotropy ID DAMPING CONSTANT; DYNAMICS AB Large angle rotations were studied in Permalloy thin films and spin valve devices. It is shown that edge effects or inhomogeneities strongly influence the magnetization behavior under certain initial conditions. Complicated intermediate states can form which significantly increase the magnetization response time. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Kabos, P (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Silva, Thomas/C-7605-2013 OI Silva, Thomas/0000-0001-8164-9642 NR 8 TC 8 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3050 EP 3052 DI 10.1109/20.908675 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700284 ER PT J AU Alejos, O Della Torre, E AF Alejos, O Della Torre, E TI Improving numerical simulations of Preisach models for accuracy and speed SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE cobweb grid; hard magnetic materials; hysteresis modeling Preisach models AB We present a useful technique to calculate the magnetic response of hard magnetic materials to the application of magnetic fields. We consider that these materials can be described by means of Preisach-based models and the parameters defining the material are distributed according to a Gaussian function. We find that the utilization of a grid in a "cobweb" style can help us to improve both accuracy and speed for this kind of simulations. We show the usefulness of this grid by solving in an easy way inverse type problems. C1 George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Alejos, O (reprint author), George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. RI Alejos, Oscar/K-5745-2014 NR 4 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3102 EP 3104 DI 10.1109/20.908698 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700301 ER PT J AU Bennett, LH Waterstrat, RM Swartzendruber, LJ Watson, RE AF Bennett, LH Waterstrat, RM Swartzendruber, LJ Watson, RE TI Structure and magnetism in the systems Zr-3(Rh1-xRux)(4) and Zr-3(Rh1-yPdy)(4) SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE B2 structure; ferromagnetism; incommensurate waves; Pu3Pd4 structure; Zr-Rh-Pd; Zr-Rh-Ru systems ID FERROMAGNETISM AB The Zr-3(Rh(1-y)Pdy)(4) system in the Pu3Pd4 structure, reported on previously, is further investigated here, it exhibits an incommensurate density wave for 0.04 less than or equal to y less than or equal to 0.06, accompanied by strongly varying paramagnetism, It displays weak ferromagnetism at one composition and weak superconductivity at an other, Changes in cooperative behavior with such small changes in composition are unique for a metallic system, The present results indicate that there is a charge density wave of constant wave vector direction and varying lattice displacements in this composition range, with microcracks developing for y = 0.04. C1 George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bennett, LH (reprint author), George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3502 EP 3504 DI 10.1109/20.908874 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700422 ER PT J AU Evans, MB AF Evans, MB TI Challenges in developing research-based web design guidelines SO IEEE TRANSACTIONS ON PROFESSIONAL COMMUNICATION LA English DT Article DE evidence-based guidelines; research-based guidelines; usability guidelines; Web design; Web usability ID TRIALS; BIAS AB Formulating design guidelines from research results can potentially offer two advantages: available empirical knowledge is distilled into a readily accessible form, and practitioners can judge the authority of those guidelines for themselves. But a case history demonstrates that challenges confront the der eloper of research-based guidelines for website design. First, few studies of people using the Web have yet been conducted. Second, when the process of guideline development is not systematic and designed to control bias and subjectivity, the resulting guidelines can be compromised. This paper describes the issues and problems one guideline developer encountered and suggests a guideline development process that might resolve them. C1 NOAA, Off Response & Restorat, Seattle, WA 98115 USA. RP Evans, MB (reprint author), NOAA, Off Response & Restorat, Seattle, WA 98115 USA. NR 31 TC 8 Z9 8 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0361-1434 J9 IEEE T PROF COMMUN JI IEEE Trans. Prof. Commun. PD SEP PY 2000 VL 43 IS 3 BP 302 EP 312 DI 10.1109/47.867946 PG 11 WC Communication; Engineering, Multidisciplinary SC Communication; Engineering GA 352MH UT WOS:000089222100006 ER PT J AU Howe, DA AF Howe, DA TI The total deviation approach to long-term characterization of frequency stability SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article; Proceedings Paper CT Joint Meeting of the European-Frequency-and-Time-Forum/IEEE International Frequency Control Symposium CY APR 13-16, 1999 CL BESANCON, FRANCE SP Soc Francaise Microtechn & Chronometrie, IEEE ID VARIANCE AB Total variance represents the first advancement in the estimation of an oscillating signal's long-term frequency stability since the conventional Allan variance estimator. It is called "Totvar" (pronounced tot'-var) for short. Its commonly reported square-root is the total deviation function called "Totdev" (tot'-dev). Totdev efficiently extracts broadband FM oscillator noise levels and types commonly encountered at long-term tau-averaging times, even though these are difficult to measure. The notable advantages of Totdev include: significantly improved confidence for estimating long-term frequency stability, lower sensitivity to the removal of linear frequency drift, and exact decomposition of the sample variance of frequency residuals. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Howe, DA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM dhowe@nist.gov NR 25 TC 25 Z9 35 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD SEP PY 2000 VL 47 IS 5 BP 1102 EP 1110 DI 10.1109/58.869040 PG 9 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 355EE UT WOS:000089372500004 PM 18238647 ER PT J AU Vukicevic, N Zibrov, AS Hollberg, L Walls, FL Kitching, J Robinson, HG AF Vukicevic, N Zibrov, AS Hollberg, L Walls, FL Kitching, J Robinson, HG TI Compact diode-laser based rubidium frequency reference SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article; Proceedings Paper CT Joint Meeting of the European-Frequency-and-Time-Forum/IEEE International Frequency Control Symposium CY APR 13-16, 1999 CL BESANCON, FRANCE SP Soc Francaise Microtechn & Chronometrie, IEEE ID SPECTROSCOPY AB The performance of a simple microwave frequency reference based on Raman scattering in an atomic vapor is examined. This reference has the potential to be compact, low-power, and insensitive to acceleration. Several design architectures have been evaluated with a tabletop experiment in order to guide the future development of a compact system. Fractional frequency deviations of less than or equal to 5 X 10(-11) appear to be feasible. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Vukicevic, N (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, M-S 847-10,325 Broadway, Boulder, CO 80303 USA. RI Zibrov, Alexander/G-7419-2014 NR 10 TC 16 Z9 16 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD SEP PY 2000 VL 47 IS 5 BP 1122 EP 1126 DI 10.1109/58.869047 PG 5 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 355EE UT WOS:000089372500007 PM 18238650 ER PT J AU Romisch, S Kitching, J Ferre-Pikal, E Hollberg, L Walls, FL AF Romisch, S Kitching, J Ferre-Pikal, E Hollberg, L Walls, FL TI Performance evaluation of an optoelectronic oscillator SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article; Proceedings Paper CT Joint Meeting of the European-Frequency-and-Time-Forum/IEEE International Frequency Control Symposium CY APR 13-16, 1999 CL BESANCON, FRANCE SP Soc Francaise Microtechn & Chronometrie, IEEE AB Phase noise measurements of an optoelectronic oscillator (OEO) at frequencies less than 10 Hz from the carrier (10.6 GHz) as well as the measured Allan variance are presented for the first time. The system has a measured single-side-band (SSB) phase-noise of -123 dB/Ha at 10 kHz from the carrier and a sigma(y)(tau) = 10(-10) for an integration time between 1 and 10 seconds. The importance of amplifier phase-noise and environmental fluctuations in determining the noise of the oscillator at these low Fourier frequencies is verified experimentally and analyzed using a generalized model of noise sources in the OEOs. This analysis then allows prediction of the oscillator performance from measured parameters of individual components in the system. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Wyoming, Laramie, WY 82071 USA. RP Romisch, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM romisch@boulder.nist.gov NR 10 TC 40 Z9 40 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD SEP PY 2000 VL 47 IS 5 BP 1159 EP 1165 DI 10.1109/58.869060 PG 7 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 355EE UT WOS:000089372500013 PM 18238656 ER PT J AU Voorhees, EM AF Voorhees, EM TI Variations in relevance judgments and the measurement of retrieval effectiveness SO INFORMATION PROCESSING & MANAGEMENT LA English DT Article DE relevance; test collections; text retrieval evaluation; TREC ID INFORMATION AB Test collections have traditionally been used by information retrieval researchers to improve their retrieval strategies. To be viable as a laboratory tool, a collection must reliably rank different retrieval variants according to their true effectiveness. In particular, the relative effectiveness of two retrieval strategies should be insensitive to modest changes in the relevant document set since individual relevance assessments are known to vary widely. The test collections developed in the TREC workshops have become the collections of choice in the retrieval research community. To verify their reliability, NIST investigated the effect changes in the relevance assessments have on the evaluation of retrieval results. Very high correlations were found among the rankings of systems Produced using different relevance judgment sets. The high correlations indicate that the comparative evaluation of retrieval performance is stable despite substantial differences in relevance judgments, and thus reaffirm the use of the TREC collections as laboratory tools. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Voorhees, EM (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8940, Gaithersburg, MD 20899 USA. RI Voorhees, Ellen/D-1755-2013 NR 17 TC 96 Z9 96 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4573 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PD SEP PY 2000 VL 36 IS 5 BP 697 EP 716 DI 10.1016/S0306-4573(00)00010-8 PG 20 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA 318QP UT WOS:000087256800001 ER PT J AU Bentley, ML Mote, TL Byrd, SF AF Bentley, ML Mote, TL Byrd, SF TI A synoptic climatology of derecho producing mesoscale convective systems in the North-Central Plains SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE derechos; Great Plains; synoptic climatology ID SEVERE WEATHER OUTBREAKS; UNITED-STATES; SQUALL LINES; REAR-INFLOW; BOW ECHO; EVOLUTION; COMPLEXES; STORMS AB Synoptic-scale environments favourable for producing derechos, or widespread convectively induced windstorms, in the North-Central Plains are examined with the goal of providing pattern-recognition/diagnosis techniques. Fifteen derechos were identified across the North-Central Plains region during 1986-1995. The synoptic environment at the initiation, mid-point and decay of each derecho was then evaluated using surface, upper-air and National Center for Atmospheric Research (NCAR)/National Center for Environmental Prediction (NCEP) reanalysis datasets. Results suggest that the synoptic environment is critical in maintaining derecho producing mesoscale convective systems (DMCSs). The synoptic environment in place downstream of the MCS initiation region determines the movement and potential strength of the system. Circulation around surface low pressure increased the instability gradient and maximized leading edge convergence in the initiation region of nearly all events regardless of DMCS location or movement. Other commonalities in the environments of these events Include the presence of a weak thermal boundary, high convective instability and a layer of dry low-to-mid-tropospheric air. Of the two corridors sampled, northeastward moving derechos tend to initiate east of synoptic-scale troughs, while southeastward moving derechos form on the northeast periphery of a synoptic-scale ridge. Other differences between these two DMCS events are also discussed. Copyright (C) 2000 Royal Meteorological Society. C1 No Illinois Univ, Dept Geog, De Kalb, IL 60115 USA. Univ Georgia, Climatol Res Lab, Athens, GA 30602 USA. Natl Weather Serv, Forecast Off, Valley, NE USA. RP Bentley, ML (reprint author), No Illinois Univ, Dept Geog, De Kalb, IL 60115 USA. NR 44 TC 16 Z9 16 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD SEP PY 2000 VL 20 IS 11 BP 1329 EP 1349 DI 10.1002/1097-0088(200009)20:11<1329::AID-JOC537>3.0.CO;2-F PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 355ZE UT WOS:000089417800002 ER PT J AU Zhu, JY Choi, MY Mulholland, GW Gritzo, LA AF Zhu, JY Choi, MY Mulholland, GW Gritzo, LA TI Measurement of soot optical properties in the near-infrared spectrum SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID VOLUME FRACTION; REFRACTIVE-INDEXES; DIFFUSION FLAMES; TEMPERATURE; OXIDATION AB The dimensionless extinction constant, K-e, was measured using the NIST Large Agglomerate Optics Facility (LAOF) for soot produced from acetylene and ethene flames. Measurements were performed simultaneously using light sources at 632.8 and 856 nm. The experiments at 856 nm represent the longest wavelength for which accurate extinction measurements have been performed for soot. The mean values of present measurements of K-e at 632.8 nm for the acetylene and ethene soot are 8.12 +/- 0.59 and 9.65 +/- 0.54, respectively. For acetylene, the mean Value of K-e measured at 856 nm was 8.83 +/- 0.69, whereas the mean value for ethene at the same wavelength was 9.35 +/- 0.51. The reduction in discrepancy for the fuels between 632.8 and 856 nm may be related to beam shielding effects. As in the case of 632.8 nm, the measured K-e values for 856 nm are significantly larger than values calculated using traditional methods. The present measurements provide a more reliable value of K-e for use in optical-based soot diagnostics. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Mech Engn, Chicago, IL 60607 USA. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Sandia Natl Labs, Unsteady & React Fluid Mech, Albuquerque, NM 87185 USA. RP Choi, MY (reprint author), Univ Illinois, Dept Mech Engn, 842 W Taylor St, Chicago, IL 60607 USA. NR 19 TC 20 Z9 20 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 2000 VL 43 IS 18 BP 3299 EP 3303 DI 10.1016/S0017-9310(99)00382-8 PG 5 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 333YY UT WOS:000088159400004 ER PT J AU Jargon, JA Gupta, KC DeGroot, DC AF Jargon, JA Gupta, KC DeGroot, DC TI Artificial neural network modeling for improved on-wafer OSLT calibration standards SO INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING LA English DT Article DE artificial neural network; network analyzer; calibration model; standards ID DESIGN AB We apply artificial neural networks (ANNs) to improve the modeling of an-wafer open-short-load-thru (OSLT) standards used for calibrating vector network analyzers, The ANNs are trained with measurement data obtained from a benchmark multiline thru-reflect-line (TRL) calibration. We assess the accuracy of an OSLT calibration using these ANN-modeled standards, and find that it compares favorably (less than a 0.02 difference in magnitude) to the benchmark multiline TRL calibration over a 40 GHz bandwidth. We also quantify the training errors and training times as a function of both the number of training points and the number of neurons in the hidden layer. (C) 2000 John Wiley Be Sons, Inc. C1 Natl Inst Stand & Technol, RF Elect Grp, Boulder, CO 80303 USA. Univ Colorado, CAMPmode, Boulder, CO 80309 USA. RP Gupta, KC (reprint author), Natl Inst Stand & Technol, RF Elect Grp, 325 Broadway, Boulder, CO 80303 USA. NR 20 TC 4 Z9 4 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1096-4290 J9 INT J RF MICROW C E JI Int. J. RF Microw. Comput-Aid. Eng. PD SEP PY 2000 VL 10 IS 5 BP 319 EP 328 DI 10.1002/1099-047X(200009)10:5<319::AID-MMCE7>3.0.CO;2-5 PG 10 WC Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 350EW UT WOS:000089088700006 ER PT J AU Wilhelm, J Gillis, KA Mehl, JB Moldover, MR AF Wilhelm, J Gillis, KA Mehl, JB Moldover, MR TI An improved Greenspan acoustic viscometer SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE acoustic resonator; argon; Greenspan viscometer; helium; helium-xenon mixture; methane; nitrogen; speed of sound; viscosity of gases; xenon ID THERMAL-CONDUCTIVITY; NOBLE-GASES; SPEED; SOUND; TEMPERATURES; PRESSURES; MIXTURES; METHANE; ARGON AB An improved Greenspan acoustic viscometer (double Helmholtz resonator) was used to measure the viscosity of gases at temperatures from 250 to 400 K and at pressures up to 3.4 MPa. The improvements include a vibration damping suspension and the relocation of the fill duct. The fill duct, which is needed to supply gas to the resonator, was connected to the center of the resonator to eliminate acoustic coupling between the resonator and the manifold. In anticipation of handling corrosive gases, all surfaces of the apparatus that are exposed to the test gas are made of metal. The viscometer was tested with argon, helium, xenon, nitrogen, and methane. Isothermal measurements were carried out at 298.15 and 348.15 K and at pressures up to 3.2 MPa. Without calibration, the results differed from published viscosity data by -0.8% to +0.3% (0.47% r.m.s.). These results are significantly better than previous results from Greenspan viscometers. The measurements also yielded the speed of sound, which differed from literature data by +0.16% to +0.20% (0.18% r.m.s.). Adding empirical effective-urea and effective-volume corrections to the data analysis decreased the r.m.s. deviations to 0.12% for the viscosity and to 0.006% for the speed of sound. No unusual phenomena were encountered when the viscometer was tested with a helium-xenon mixture between 250 and 375 K. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Moldover, MR (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 19 TC 12 Z9 12 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2000 VL 21 IS 5 BP 983 EP 997 DI 10.1023/A:1026471901657 PG 15 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 380NA UT WOS:000165706900001 ER PT J AU Magee, JW Outcalt, SL Ely, JF AF Magee, JW Outcalt, SL Ely, JF TI Molar heat capacity C-v, vapor pressure, and (p, rho, T) measurements from 92 to 350 K at pressures to 35 MPa and a new equation of state for chlorotrifluoromethane (R13) SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE calorimeter; chlorotrifluoromethane; density; equation of state; heat capacity; isochoric; liquid; R13; vapor; vapor pressure AB Measurements of the molar heat capacity at constant volume C-V for chlorotrifluoromethane (R13) were conducted using an adiabatic method. Temperatures ranged from 95 to 338 K, and pressures were as high as 35 MPa. Measurements of vapor pressure were made using a static technique from 250 to 302 K. Measurements of (p, rho, T) properties were conducted using an isochoric method; comprehensive measurements were conducted at 15 densities which varied from dilute vapor to highly compressed liquid, at temperatures from 92 to 350 K. The R13 samples were obtained from the same sample bottle whose mole fraction purity was measured at 0.9995. A test equation of stale including ancillary equations was derived using the new vapor pressures and (p, rho, T) data in addition to similar published data. The equation of stale is a modified Benedict-Webb-Rubin type with 32 adjustable coefficients. Acceptable agreement of C-V predictions with measurements was found. Published C-V(rho, T) data suitable for direct comparison with this study do not exist. The uncertainty of the C-V values is estimated to be less than 2.0% for vapor and 0.5% for liquid. The uncertainty of the vapor pressures is 1 kPa, and that of the density measurements is 0.1%. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 23 TC 9 Z9 9 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2000 VL 21 IS 5 BP 1097 EP 1121 DI 10.1023/A:1026446004383 PG 25 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 380NA UT WOS:000165706900007 ER PT J AU Watts, LA Louie, B AF Watts, LA Louie, B TI Apparatus for measuring vapor-liquid equilibria and phase densities of complex aqueous solutions SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE azeotrope; corrosive; density; ethanol; mixture; salts; vapor-liquid equilibria; VLE; vapor pressure ID THERMODYNAMIC PROPERTIES; PRESSURES; MIXTURES; ETHANOL; TEMPERATURE; 1-ALKANOLS; ALCOHOLS; EQUATION; OXYGEN; STATE AB A new apparatus has been designed and constructed to measure the vapor-liquid equilibria and phase densities of corrosive, complex aqueous solutions containing organic solvents and salts. The apparatus is designed for isothermal operation from ambient temperatures to 400 K. Phase equilibrium measurements at higher temperatures may be achieved without density measurements. This paper presents a detailed description and performance testing of the apparatus. Measurements of the vapor pressures and saturated liquid densities of ethanol and the vapor pressure of an ethanol-water mixture (X-ethanol = 0.6743 mole fraction) from 308 to 385 K at pressures to 15 MPa are used as performance tests. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Watts, LA (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. RI Watts, Laurel/G-4532-2013 OI Watts, Laurel/0000-0002-0834-3329 NR 15 TC 4 Z9 4 U1 1 U2 6 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2000 VL 21 IS 5 BP 1139 EP 1151 DI 10.1023/A:1026450105292 PG 13 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 380NA UT WOS:000165706900009 ER PT J AU Bruckner, AW AF Bruckner, AW TI New threat to coral reefs: Trade in coral organisms SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Article C1 Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. RP Bruckner, AW (reprint author), Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. NR 0 TC 4 Z9 4 U1 2 U2 3 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 2000 VL 17 IS 1 BP 63 EP 68 PG 6 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 397RJ UT WOS:000166709100039 ER PT J AU Rose, JB Daeschner, S Easterling, DR Curriero, FC Lele, S Patz, JA AF Rose, JB Daeschner, S Easterling, DR Curriero, FC Lele, S Patz, JA TI Climate and waterborne disease outbreaks SO JOURNAL AMERICAN WATER WORKS ASSOCIATION LA English DT Article ID UNITED-STATES; INFECTIOUS-DISEASES; CRYPTOSPORIDIUM; MILWAUKEE; TURBIDITY; RAINFALL; GIARDIA AB Regional climate change and variability and their effect on water resources have not been the subject of much study. Climate predictions suggest that storms will be of greater intensity and that the average precipitation event is likely to be heavier. Rainfall and runoff have been associated with individual outbreaks of waterborne disease caused by fecal-oral pathogens. Waterborne disease outbreak data from 1971 through 1994 were analyzed for groundwater and surface water in 2,105 US watersheds. Between 20 and 40 percent of outbreaks were associated with extreme precipitation. This relationship with extreme precipitation was found to be statistically significant for both surface water and groundwater, although it was more apparent with surface water outbreaks. The authors offer recommendations for improving the assessment of changes in water quality and the effect that climate variability and environmental factors have on waterborne disease risk. C1 Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. Natl Ocean & Atmospher Adm, Global Climate Lab, Asheville, NC 28801 USA. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Biostat, Baltimore, MD 21205 USA. Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2G1, Canada. Johns Hopkins Univ, Dept Environm Hlth Sci, Baltimore, MD 21218 USA. RP Rose, JB (reprint author), Univ S Florida, Coll Marine Sci, 140 7th Ave S, St Petersburg, FL 33701 USA. NR 33 TC 59 Z9 63 U1 0 U2 17 PU AMER WATER WORKS ASSOC PI DENVER PA 6666 W QUINCY AVE, DENVER, CO 80235 USA SN 0003-150X J9 J AM WATER WORKS ASS JI J. Am. Water Work Assoc. PD SEP PY 2000 VL 92 IS 9 BP 77 EP 87 PG 11 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA 434VG UT WOS:000168836100007 ER PT J AU Tai, SSC Welch, MJ AF Tai, SSC Welch, MJ TI Determination of 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid in a urine-based standard reference material by isotope-dilution liquid chromatography-mass spectrometry with electrospray ionization SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article ID SOLID-PHASE EXTRACTION; GC-MS; CERTIFICATION; METABOLITE C1 Coll Amer Pathologists, Northfield, IL 60093 USA. NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Tai, SSC (reprint author), Coll Amer Pathologists, Northfield, IL 60093 USA. NR 12 TC 15 Z9 16 U1 0 U2 0 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD SEP PY 2000 VL 24 IS 6 BP 385 EP 389 PG 5 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 352QF UT WOS:000089228800001 PM 10999343 ER PT J AU Zrnic, DS Keenan, TD Carey, LD May, P AF Zrnic, DS Keenan, TD Carey, LD May, P TI Sensitivity analysis of polarimetric variables at a 5-cm wavelength in rain SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID POLARIZATION RADAR MEASUREMENTS; PROPAGATION PHASE-SHIFT; DIFFERENTIAL PHASE; WIND-TUNNEL; PRECIPITATION; SYSTEMS; GAUGES; RATES; SHAPE; WATER AB Sensitivity of 5-cm-wavelength polarimetric radar measurements to raindrop size and distribution is investigated. At this wavelength, resonance occurs for sizes larger than about 5 mm, and therefore several polarimetric variables exhibit nonmonotone dependence on the drop diameter The resonance effect is examined for temperatures of 0 degrees, 10 degrees, 20 degrees, and 30 degrees C. Through use of truncated gamma distributions (parameterized as a function of rain rate from the Maritime Continent Thunderstorm Experiment), and truncated Marshall-palmer distributions, the influence of the upper tail of the drop size distribution is brought out This poorly documented region of sizes can have a significant effect on some polarimetric variables. These simulations are extended further to include estimates of rain rate from the reflectivity factor Z, the specific differential phase K-DP, the combined use of K-DP and differential reflectivity Z(DR), and the combined use of Z and Z(DR). C1 NOAA Ocean & Atmospher Res, Natl Severe Storms Lab, Norman, OK 73069 USA. But Meteorol Res Ctr, Melbourne, Vic, Australia. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Zrnic, DS (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 49 TC 33 Z9 33 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 2000 VL 39 IS 9 BP 1514 EP 1526 DI 10.1175/1520-0450(2000)039<1514:SAOPVA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 360KC UT WOS:000089665700007 ER PT J AU Boone, A Masson, V Meyers, T Noilhan, J AF Boone, A Masson, V Meyers, T Noilhan, J TI The influence of the inclusion of soil freezing on simulations by a soil-vegetation-atmosphere transfer scheme SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID LAND-SURFACE SCHEME; SEASONALLY FROZEN SOILS; FORCE-RESTORE METHOD; PARAMETERIZATION SCHEMES; BOUNDARY-LAYER; HYDRAULIC-PROPERTIES; HETEROGENEOUS LAND; HAPEX-MOBILHY; CLIMATE MODEL; ENERGY FLUXES AB The interactions between the soil biosphere, and atmosphere (ISBA) land surface parameterization scheme has been modified to include soil ice. The liquid water equivalent volumetric ice content is modeled using two reservoirs within the soil: a thin surface layer that directly affects the surface energy balance, and a deep soil layer The freezing/drying, wetting/thawing analogy is used, and a description of the modifications to the ISBA force-restore scheme, in particular to the hydrological and thermal transfer coefficients, is presented. In addition, the ISBA surface/vegetation scheme is coupled to a multilayer explicit diffusion soil heat and mass transfer model in order to investigate the accuracy of the force-restore formalism soil freezing parameterization as compared with a higher-order scheme, An example of the influence of the inclusion of soil freezing in ISBA on predicted surface and soil temperatures and surface fluxes is examined using prescribed atmospheric forcing from a micrometeorological case study that includes freeze-thaw cycles. Surface temperature prediction is improved in comparison with the observed values, especially at night. primarily from the release of latent heat as the soil freezes. There is an improvement in the overall surface flux prediction, although for some specific periods there is increased error in the prediction of various components of the surface energy budget. Last, the simplified force-restore approach is found to produce surface Bur and temperature predictions consistent with the higher-resolution model, on typical numerical weather prediction model timescales (on the order of several days to two weeks) for this particular site. C1 Meteo France, CNRM, GMME, F-31057 Toulouse, France. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN USA. RP Boone, A (reprint author), Meteo France, CNRM, GMME, MC2,42 Ave Coriolis, F-31057 Toulouse, France. EM boone@cnrm.meteo.fr RI Meyers, Tilden/C-6633-2016 NR 64 TC 77 Z9 77 U1 0 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 2000 VL 39 IS 9 BP 1544 EP 1569 DI 10.1175/1520-0450(2000)039<1544:TIOTIO>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 360KC UT WOS:000089665700009 ER PT J AU Eischeid, JK Pasteris, PA Diaz, HF Plantico, MS Lott, NJ AF Eischeid, JK Pasteris, PA Diaz, HF Plantico, MS Lott, NJ TI Creating a serially complete, national daily time series of temperature and precipitation for the western United States SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB The development of serially complete (no missing values) daily maximum-minimum temperatures and total precipitation time series over the western United States is documented. Several estimation techniques based on spatial objective analysis schemes are used to estimate daily values, with the "best" estimate chosen as a missing value replacement. The development of a continuous and complete daily dataset will be useful in a variety of meteorological and hydrological research applications. The spatial interpolation schemes are evaluated separately by interpolation method and calendar month. Cross validation of the results indicates a distinct seasonality to the efficiency (error) of the estimates, although no systematic bias in the estimation procedures was found. The resulting number of serially complete dairy time series for the western United States (ail states west of the Mississippi River) includes 2034 maximum-minimum temperature stations and 2962 total daily precipitation locations. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. Nat Resources Conservat Serv, Portland, OR USA. NOAA, Resources Conservat Serv, Boulder, CO USA. NOAA, Natl Climat Data Ctr, Asheville, NC USA. RP Eischeid, JK (reprint author), Univ Colorado, CIRES, Campus Box 449, Boulder, CO 80309 USA. NR 14 TC 99 Z9 106 U1 2 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 2000 VL 39 IS 9 BP 1580 EP 1591 DI 10.1175/1520-0450(2000)039<1580:CASCND>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 360KC UT WOS:000089665700011 ER PT J AU Kim, S Ledbetter, H Ogi, H AF Kim, S Ledbetter, H Ogi, H TI Elastic stiffnesses of an Nb-Ti/Cu-composite superconductive wire SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ACOUSTIC-RESONANCE; BORON-ALUMINUM; CONSTANTS; SPECTROSCOPY AB Elastic-stiffness coefficients were determined on a 1.4-mm-diameter wire consisting of superconducting Nb-Ti fibers in a copper matrix, with a polyvinyl-resin coating. The matrix contained 324 Nb-Ti fibers. An electromagnetic-acoustic-resonance method was used to obtain five independent elastic-stiffness coefficients assuming transverse-isotropic symmetry. From these we calculated Young moduli, bulk modulus, and principal Poisson ratios. As a check, we used a mechanical-impulse-excitation method to directly measure the Young modulus in the fiber direction. The three-phase composite wire showed a 10% anisotropy in the Young modulus. (C) 2000 American Institute of Physics. [S0021-8979(00)03518-0]. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. Osaka Univ, Grad Sch Engn Sci, Osaka, Japan. RP Kim, S (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, 325 Broadway, Boulder, CO 80303 USA. NR 12 TC 4 Z9 4 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2000 VL 88 IS 5 BP 2378 EP 2381 AR PII [S0021-8979(00)03518-0] DI 10.1063/1.1288220 PG 4 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500032 ER PT J AU Robey, SW Sinniah, K AF Robey, SW Sinniah, K TI Initial etching of GaAs (001) during H-2 plasma cleaning SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RESONANCE HYDROGEN PLASMA; SURFACE-ROUGHNESS; LOW-TEMPERATURES; ATOMIC-HYDROGEN; CYCLOTRON; (100)SILICON; MORPHOLOGY; OXIDE AB The initial etching of GaAs (001) during remote H-2 plasma etching for oxide removal was examined using atomic force microscopy, coupled with in situ reflection high energy diffraction and Auger spectroscopy. Localized etching of the GaAs surface is particularly evident for etch temperatures below similar to 650 K and leads to the formation of etch pits 5-10 nm deep and 20-50 nm in diameter. Etch pit formation was found to occur well before complete oxide removal. The development of etch pits is influenced by surface mis-cut steps, possibly due to increased hydrogen incorporation into the near surface at surface defects such as steps. [S0021-8979(00)00217-6]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Calvin Coll, Dept Chem & Biochem, Grand Rapids, MI 49546 USA. RP Robey, SW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Schaff, William/B-5839-2009 NR 18 TC 1 Z9 1 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2000 VL 88 IS 5 BP 2994 EP 2998 AR PII [S0021-8979(00)00217-6] DI 10.1063/1.1287125 PG 5 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500129 ER PT J AU White, AB Jordan, JR Martner, BE Ralph, FM Bartram, BW AF White, AB Jordan, JR Martner, BE Ralph, FM Bartram, BW TI Extending the dynamic range of an S-band radar for cloud and precipitation studies SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MICROPHYSICAL PARAMETERS; PROFILER AB A new S-band vertical profiler with a coupler option for extending the dynamic range of the radar's receiver is discussed. The added dynamic range allows the profiler to record radar reflectivity measurements in moderate to heavy precipitation that otherwise would not have been possible with this system because of receiver saturation. The radar hardware, signal processor, and operating software are based on existing S-band and UHF profiler technology. Results from a side-by side comparison with a calibrated Ka-band radar are used to determine the calibration and sensitivity of the S-band profiler. In a typical cloud profiling mode of operation, the sensitivity is -14 dBZ at 10 km. Examples taken from a recent field campaign are shown to illustrate the profiler's ability to measure vertical velocity and radar reflectivity profiles in clouds and precipitation, with particular emphasis on the benefit provided by the coupler technology. C1 NOAA, ETL, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP White, AB (reprint author), NOAA, ETL, 325 Broadway,R-ET7, Boulder, CO 80303 USA. RI White, Allen/A-7946-2009 NR 14 TC 53 Z9 54 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2000 VL 17 IS 9 BP 1226 EP 1234 DI 10.1175/1520-0426(2000)017<1226:ETDROA>2.0.CO;2 PG 9 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 362MY UT WOS:000089782800006 ER PT J AU Trokhimovski, YG AF Trokhimovski, YG TI Gravity-capillary wave curvature spectrum and mean-square slope retrieved from microwave radiometric measurements (Coastal Ocean Probing Experiment) SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID COUPLED SHEAR-FLOW; SEA-SURFACE SLOPE; SHORT WIND-WAVES; NUMBER SPECTRA; IMPROVED MODEL; FREQUENCY; WATER; SCATTERING; GROWTH; BACKSCATTERING AB Brightness temperature of the sea surface is determined by surface waves of different scales. Polarimetric measurements collected by microwave radiometers at several viewing angles and frequencies give an opportunity to convert the observed brightness temperatures to the mean-square slope of long waves and curvature spectral density in the gravity-capillary interval without a priori assumptions about the shape of spectrum. Such an inversion was made using radiometric data collected during the Coastal Ocean Probing Experiment (COPE'95) from a blimp. It is shown that at low and moderate wind speed conditions typical for COPE'95 (4-7 m s(-1)) the curvature spectrum has a maximum at wavenumber of about 4.5 rad cm(-1), slightly higher than the wavenumber of the phase velocity minimum. The maximum corresponds to the wavenumber with the highest initial growth rate as predicted by theory for the growth rate of wind-induced gravity-capillary waves based on the OrrSommerfeld equation. The author's estimation of the mean-square slope of surface waves is very close to the Cox and Munk values for stable and unstable atmospheric stratification. The radiometric results are compared with several gravity-capillary wave spectral models. C1 NOAA, Environm Technol Lab, ERL, Boulder, CO 80303 USA. RP Trokhimovski, YG (reprint author), NOAA, Environm Technol Lab, ERL, R-E-ET1,325 Broadway, Boulder, CO 80303 USA. NR 59 TC 16 Z9 17 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2000 VL 17 IS 9 BP 1259 EP 1270 DI 10.1175/1520-0426(2000)017<1259:GNCWCS>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 362MY UT WOS:000089782800010 ER PT J AU Onsager, T Ginet, GP Behnke, RA AF Onsager, T Ginet, GP Behnke, RA TI Space Weather Week - Preface SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Editorial Material C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Onsager, T (reprint author), NOAA, Space Environm Ctr, 325 Broadway R-E-SE, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD SEP PY 2000 VL 62 IS 14 BP 1221 EP 1221 DI 10.1016/S1364-6826(00)00108-5 PG 1 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 372VW UT WOS:000165255600001 ER PT J AU Tobiska, WK Woods, T Eparvier, F Viereck, R Floyd, L Bouwer, D Rottman, G White, OR AF Tobiska, WK Woods, T Eparvier, F Viereck, R Floyd, L Bouwer, D Rottman, G White, OR TI The SOLAR2000 empirical solar irradiance model and forecast tool SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT NOAA Space Weather Week Meeting CY APR 19-23, 1999 CL BOULDER, COLORADO SP NOAA, Space Environm Ctr, USAF Res Lab, Natl Sci Fdn DE solar spectrum; solar irradiances; solar EUV; SOLAR2000; space weather forecasts ID EUV FLUX MODEL; SOLSPEC SPECTROMETER; SPECTRAL IRRADIANCE; ULTRAVIOLET FLUX; VARIABILITY; NM AB SOLAR2000 is a collaborative project for accurately characterizing solar irradiance variability across the spectrum. A new image- and full-disk proxy empirical solar irradiance model, SOLAR2000, is being developed that is valid in the spectral range of 1-1,000,000 nm for historical modeling and forecasting throughout the solar system. The overarching scientific goal behind SOLAR2000 is to understand how the Sun varies spectrally and through time from X-ray through infrared wavelengths. This will contribute to answering key scientific questions and will aid national programmatic goals related to solar irradiance specification. SOLAR2000 is designed to be a fundamental energy input into planetary atmosphere models, a comparative model with numerical/first principles solar models, and a tool to model or predict the solar radiation component of the space environment, It is compliant with the developing International Standards Organization (ISO) solar irradiance standard. SOLAR2000 captures the essence of historically measured solar irradiances and this expands our knowledge about the quiet and variable Sun including its historical envelope of variability. The implementation of the SOLAR2000 is described, including the development of a new EUV proxy, E10.7, which has the same units as the commonly used F10.7. SOLAR2000 also provides an operational forecasting and global specification capability for solar irradiances and information can be accessed at the website address of http://www.spacenvironment.net. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, FDC, Pasadena, CA 91109 USA. Univ Colorado, LASP, Boulder, CO 80309 USA. NOAA, FDC, SEC, Boulder, CO 80303 USA. RP Tobiska, WK (reprint author), CALTECH, Jet Prop Lab, FDC, 4800 Oak Grove Dr,MS 264-580, Pasadena, CA 91109 USA. NR 45 TC 295 Z9 302 U1 5 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD SEP PY 2000 VL 62 IS 14 BP 1233 EP 1250 DI 10.1016/S1364-6826(00)00070-5 PG 18 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 372VW UT WOS:000165255600003 ER PT J AU Smith, Z Dryer, M Ort, E Murtagh, W AF Smith, Z Dryer, M Ort, E Murtagh, W TI Performance of interplanetary shock prediction models: STOA and ISPM SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT NOAA Space Weather Week Meeting CY APR 19-23, 1999 CL BOULDER, COLORADO SP NOAA, Space Environm Ctr, USAF Res Lab, Natl Sci Fdn DE space weather; shock predictions ID SOLAR-WIND; DISTURBANCES; SCINTILLATION AB The shock time of arrival (STOA) model and the interplanetary shock propagation model (ISPM) give predictions of the time of arrival and strength of solar-initiated interplanetary shocks. This paper presents the first operational predictions made of interplanetary shocks that follow solar events. The time interval of this study was February 1997-March 1999 (the rise of Solar Cycle 23). The results are presented in contingency-table form (whether or not a shock was predicted and/or observed) and also as the time differences (errors) between the predicted and observed shock arrivals. These results are compared to the accuracies that would be obtained using a constant, representative value (Rule of Thumb or R-T) for the transit time. The results show the percentage of successful predictions to within an accuracy of 12 h of shocks for the STOA, ISPM and R-T are 53, 58, and 33%, respectively. The corresponding root mean square (rms) errors of the shock arrival times are 15.0, 15.1 and 14.8 h. Note that the rms heavily weights outlying points, so although only 3 of the ISPM-predictions were off by more than 12 h, the ISPM rms is worse than that for STOA and R-T models; both of which had prediction errors > \12\ h for eight events. Statistics presented in this paper not only show the capabilities of these models, but also allow for comparison to future shuck-arrival forecasting models. These results may be considered as reference metrics in evaluating forecasting skill. The relationship of the interplanetary shocks to geomagnetic activity is also briefly considered. Published by Elsevier Science Ltd. C1 NOAA, SEC, Boulder, CO 80303 USA. NOAA Crops, Boulder, CO 80303 USA. USAF, Boulder, CO 80303 USA. RP Smith, Z (reprint author), NOAA, SEC, 325 Broadway Blvd, Boulder, CO 80303 USA. RI xue, yansheng/A-9712-2012 NR 20 TC 52 Z9 55 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD SEP PY 2000 VL 62 IS 14 BP 1265 EP 1274 DI 10.1016/S1364-6826(00)00082-1 PG 10 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 372VW UT WOS:000165255600006 ER PT J AU Ahn, BH Kroehl, HW Kamide, Y Kihn, EA AF Ahn, BH Kroehl, HW Kamide, Y Kihn, EA TI Seasonal and solar cycle variations of the auroral electrojet indices SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT NOAA Space Weather Week Meeting CY APR 19-23, 1999 CL BOULDER, COLORADO SP NOAA, Space Environm Ctr, USAF Res Lab, Natl Sci Fdn DE auroral electrojet indices; semiannual magnetic variations; electric field ID GEOMAGNETIC-ACTIVITY; IONOSPHERIC ELECTRODYNAMICS; SEMIANNUAL VARIATION; INDEXES; CONDUCTIVITY; SUBSTORM; FIELD AB Using hourly mean auroral electrojet indices for the past 20 years, we examine the seasonal and solar cycle variations of the AU and AL indices as well as the smaller time-scale fluctuations in these indices. The AU and AL indices maximize during summer and equinoctial months, respectively. By removing the effects of the solar conductance from the AU index, it is found that the electric field contribution to the AU index exhibits the same semiannual variation pattern as the AL index, indicating that the semiannual magnetic variations are controlled by the electric field. Since the auroral electrojets are mostly Hall currents flowing in the east-west direction, the fluctuations of the auroral electrojet indices can be interpreted in terms of fluctuations in the north-south component of the electric field and the Hall conductance. The AU fluctuation is largely due to that of the electric field, while the AL fluctuation is attributed to both the electric field and Hall conductance with their contributions being comparable. The high fluctuation of AL compared to that of AU is attributed to particle precipitation associated with substorm activity. However, the fluctuations of the electric field and conductance do not show any noticeable seasonal dependence. The variation pattern of the yearly mean AL index follows the mirror image of the AU index during the past 20 years, indicating that the absolute values of the two indices are proportional to each other. This suggests again that the electric field is the main modulator of magnetic disturbance. On the other hand, they show a tendency to become higher during the declining phase of the solar cycle. This is the same variation pattern confirmed from the aa index. However, the fluctuations of the electric field and the Hall conductance do not show any apparent dependence on the solar cycle. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Kyungpook Natl Univ, Dept Earth Sci, Coll Teachers, Taegu 702701, South Korea. NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Nagoya Univ, Solar Terr Environm Lab, Toyokawa, Japan. RP Ahn, BH (reprint author), Kyungpook Natl Univ, Dept Earth Sci, Coll Teachers, Taegu 702701, South Korea. RI Kihn, Eric/A-8204-2009 NR 33 TC 19 Z9 19 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD SEP PY 2000 VL 62 IS 14 BP 1301 EP 1310 DI 10.1016/S1364-6826(00)00073-0 PG 10 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 372VW UT WOS:000165255600009 ER PT J AU Harper, WW Nizkorodov, SA Nesbitt, DJ AF Harper, WW Nizkorodov, SA Nesbitt, DJ TI Quantum state-resolved reactive scattering of F+CH4 -> HF(v,J)+CH3: Nascent HF(v,J) product state distributions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; MOLECULAR-BEAM; INFRARED CHEMILUMINESCENCE; CROSS-SECTIONS; CH4+F->CH3+FH REACTION; ANGULAR-DISTRIBUTIONS; F+H-2->HF+H REACTION; SUPERSONIC JETS; FLUORINE ATOMS; REACTION F+D-2 AB State-to-state reactive scattering of F+CH4--> HF(upsilon,J) + CH3 is studied using crossed supersonic jets and high-resolution (Delta nu approximate to 0.0001 cm(-1)) IR laser direct absorption techniques. Rovibrational state-resolved HF column-integrated absorption profiles are obtained under single collision conditions and converted to populations via appropriate density-to-flux transformation. Nascent rovibrational distributions in each HF(upsilon,J) state are reported. Summed over all product rotational levels, the nascent vibrational quantum state populations for HF(upsilon) [(upsilon = 3) 0.106(3); (upsilon = 2) 0.667(14); (upsilon = 1) 0.189(27); (upsilon = 0) 0.038(78); 2 sigma error bars] are in agreement with previous flow cell studies by Setser, Heydtmann, and co-workers [Chem. Phys. 94, 109 (1985)]. At the rotational state level, however, the current studies indicate nascent distributions for HF(upsilon,J) that are significantly hotter than previously reported, ostensibly due to reduced collisional relaxation effects under supersonic jet conditions. Final HF rotational states from F+CH4 are observed near the maximum energetically accessible J values in both the upsilon = 2 and upsilon = 3 vibrational manifolds, which provides experimental support for a bent F-H-C transition state structure. (C) 2000 American Institute of Physics. [S0021-9606(00)00433-5]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Harper, WW (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Nizkorodov, Sergey/I-4120-2014 OI Nizkorodov, Sergey/0000-0003-0891-0052 NR 48 TC 62 Z9 63 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2000 VL 113 IS 9 BP 3670 EP 3680 DI 10.1063/1.1287398 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 346NR UT WOS:000088878400022 ER PT J AU Kishore, N Tewari, YB Goldberg, RN AF Kishore, N Tewari, YB Goldberg, RN TI Thermodynamic study of the hydrolysis of L-glutamine to (L-glutamate plus ammonia) and of L-asparagine to (L-aspartate plus ammonia) SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE ammonia; asparaginase; L-asparagine; L-aspartate; enthalpy; equilibrium constants; glutaminase; L-glutamate; L-glutamine ID ADENOSINE 5'-TRIPHOSPHATE; SPECIFIED PH AB Calorimetric enthalpies of reaction have been measured for the following enzyme-catalysed reactions: L-glutamine(aq) + H2O(1) = L-glutamate(aq) + ammonia(aq), L-asparagine(aq) + H2O(1) = L-aspartate(aq) + ammonia(aq). An equilibrium model that accounted for the multiplicity of ionic forms of the reactants and products was used to calculate standard molar enthalpies for reference reactions involving specific species. Values of equilibrium constants for the reference reactions were obtained using results from the literature in thermochemical cycle calculations. The thermodynamic results are discussed in relation to the structural changes involved in these reactions. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Goldberg, RN (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 40 TC 5 Z9 5 U1 2 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD SEP PY 2000 VL 32 IS 9 BP 1077 EP 1090 PG 14 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 370QM UT WOS:000165133800002 ER PT J AU Kumar, A Barnston, AG Peng, PT Hoerling, MP Goddard, L AF Kumar, A Barnston, AG Peng, PT Hoerling, MP Goddard, L TI Changes in the spread of the variability of the seasonal mean atmospheric states associated with ENSO SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURES; INTERANNUAL VARIABILITY; SST ANOMALIES; EL-NINO; PREDICTABILITY; PACIFIC; GCM; TELECONNECTIONS; PREDICTIONS; SIMULATIONS AB For a fixed sea surface temperature (SST) forcing, the variability of the observed seasonal mean atmospheric states in the extratropical latitudes can be characterized in terms of probability distribution functions (PDFs). Predictability of the seasonal mean anomalies related to interannual variations in the SSTs, therefore, entails understanding the influence of SST forcing on various moments of the probability distribution that characterize the variability of the seasonal means. Such an understanding for changes in the first moment of the PDF for the seasonal means with SSTs is well documented. In this paper the analysis is extended to include also the impact of SST forcing on the second moment of the PDFs. The analysis is primarily based on ensemble atmospheric general circulation model (AGCM) simulations forced with observed SSTs for the period 1950-94. To establish the robustness of the results and to ensure that they are not unduly affected by biases in a particular AGCM, the analysis is based on simulations from four different AGCMs. The analysis of AGCM simulations indicates that over the Pacific-North American region, the impact of interannual variations in SSTs on the spread of the seasonal mean atmospheric states (i.e., the second moment of the PDFs) may be small. This is in contrast to their well-defined impact on the first moment of the PDF for the seasonal mean atmospheric state that is manifested as an anomalous wave train over this region. For seasonal predictions, the results imply that the dominant contribution to seasonal predictability comes from the impact of SSTs on the first moment of the PDF, with the impact of SSTs on the second moment of the PDFs playing a secondary role. C1 NOAA, Natl Weather Serv, EMC, NCEP,Climate Modeling Branch, Washington, DC USA. NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, Washington, DC USA. NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. IRI SIO, Expt Forecast Div, La Jolla, CA USA. RP Kumar, A (reprint author), EMC NCEP, Climate Modeling Branch, 5200 Auth Rd,Rm 807, Camp Springs, MD 20746 USA. NR 23 TC 43 Z9 43 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP 1 PY 2000 VL 13 IS 17 BP 3139 EP 3151 DI 10.1175/1520-0442(2000)013<3139:CITSOT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359GM UT WOS:000089603200007 ER PT J AU Chelliah, M Ropelewski, CF AF Chelliah, M Ropelewski, CF TI Reanalyses-based tropospheric temperature estimates: Uncertainties in the context of global climate change detection SO JOURNAL OF CLIMATE LA English DT Article ID MICROWAVE SOUNDING UNIT; ATMOSPHERE; SATELLITE; DATASET; SERIES; TRENDS AB Uncertainties in estimates of tropospheric mean temperature were investigated in the context of climate change detection through comparisons of the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) 40-yr reanalysis (1958-97), the National Aeronautics and Space Administration Data Assimilation Office (NASA/DAO) 14-yr reanalysis (1980-93), the European Centre for Medium-Range Weather Forecasts Reanalysis Project (ERA) 15-yr reanalysis (1979-94), and the satellite microwave sounding unit channel 2 (MSU Ch2) (1979-97) temperature data. The maximum overlap period for comparison among these datasets is the 14 full years January 1980 to December 1993. This study documents similar shifts in the relative bias between the MSU Ch2 and the ERA and the NCEP-NCAR reanalyses in the 1991-97 period suggesting changes in the satellite analysis. However, the intercomparisons were not able to rule out the changes in the reanalysis systems and/or the input data on which the reanalyses are based as prime factors for the changes in the relative bias between the MSU and ERA and NCEP-NCAR reanalyses. These temporal changes in the relative bias among the reanalyses suggest their limitations for global change studies. Nonetheless, the analysis also shows that the pattern correlations (r) between the MSU Ch2 monthly mean fields and each of the reanalyses are very high, r > 0.96, and remain relatively high for the anomaly fields, r > 0.8, generally >0.9. This result suggests that reanalysis may be used for comparisons to numerical model-generated forecast fields (from GCM simulation runs) and in conjunction with "fingerprint'" techniques to identify climate change. In comparisons of the simple linear trends present in each dataset for the 1980-90 period, each of the reanalyses had spatial patterns similar to MSU Ch2 except that the NCEP-NCAR reanalysis showed smaller "positive" (warming) trends in comparison with the MSU while the ERA reanalysis showed larger positive trends. The NASA/DAO reanalysis showed a mixed pattern. Many regions of the globe are identified that showed consistent warming/cooling patterns among the major reanalyses and MSU, even though there were disagreements in the exact magnitude among the analyses. The spatial patterns of linear trends changed, however, with the addition of three years of data to extend the trend analysis to the 1980-93 period. This result suggests that such simple linear trend analyses are very sensitive to the temporal span in these relatively shea datasets and thus are of limited usefulness in the context of climate change detection except, however, when the signal is large and shows consistency among all datasets. The long record (1958-96) of seasonal mean 2-m temperature anomalies from NCEP-NCAR reanalysis is well correlated with gridded analyses of station-based observed surface temperature, with correlations between 0.65 and 0.85. It is argued that these correlations might suggest an upper limit to the magnitudes of the pattern correlations that might be obtained by correlating observed surface temperature analyses with those from multiyear GCM simulation runs made in the context of fingerprint climate change detection. C1 NCEP NWS NOAA, Climate Predict Ctr, Camp Springs, MD 20746 USA. Columbia Univ, Lamont Doherty Earth Observ, Int Res Inst Climate Predict, Palisades, NY USA. RP Chelliah, M (reprint author), NCEP NWS NOAA, Climate Predict Ctr, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 23 TC 29 Z9 29 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP 1 PY 2000 VL 13 IS 17 BP 3187 EP 3205 DI 10.1175/1520-0442(2000)013<3187:RBTTEU>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359GM UT WOS:000089603200010 ER PT J AU Boukari, H Long, GG Harris, MT AF Boukari, H Long, GG Harris, MT TI Polydispersity during the formation and growth of the Stober silica particles from small-angle X-ray scattering measurements SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE small-angle X-ray scattering; SAXS; USAXS; silica particles; maximum entropy; cumulant method ID MAXIMUM-ENTROPY METHOD; SIZE DISTRIBUTIONS; MONOMER-ADDITION; ALKOXIDES; PRECIPITATION; HYDROLYSIS; KINETICS; DYNAMICS; SPHERES; MODEL AB The early stages of formation of Stober silica particles have been investigated in situ during the hydrolysis and condensation of tetraethylorthosilicate under base-ammonia conditions in different alcoholic solvents. Time-resolved ultra-small-angle X-ray scattering by the entities produced in the solutions is used for structural characterization and monitoring of the growth kinetics of the particles. Our primary focus is to assess the polydispersity of the formed colloidal particles and its evolution as a function of time. We first applied a maximum entropy analysis of the scattering data to determine the size distribution and the time evolution of the size distribution of the colloidal particles. Second, we extended the cumulant method to analyze our earlier small-angle X-ray scattering data (H. Boukari, J. S. Lin, and M. T. Harris, J. Colloid Interface Sci. 194, 311, 1997; Chem. Mater. 9, 2376, 1997) and search for the presence of a distribution of fractal particles. The maximum entropy analysis indicates that there is a continuous nucleation of particles during the synthesis, and that this takes place within a relatively narrow size distribution. The cumulant analysis shows that, except at later times, the data are not adequate to confirm conclusively the presence of a distribution of fractal dimension at any time during the experiment. We discuss the impact of these results on growth kinetic models proposed for this system. (C) 2000 Academic Press. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Boukari, H (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 29 TC 54 Z9 54 U1 3 U2 29 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 1 PY 2000 VL 229 IS 1 BP 129 EP 139 DI 10.1006/jcis.2000.7007 PG 11 WC Chemistry, Physical SC Chemistry GA 347LE UT WOS:000088930300015 ER PT J AU Shang, EC Voronovich, AG Wang, YY Naugolnykh, K Ostrovsky, L AF Shang, EC Voronovich, AG Wang, YY Naugolnykh, K Ostrovsky, L TI New schemes of ocean acoustic tomography SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article ID REFRACTION-MODAL TOMOGRAPHY; INTERNAL SOLITONS; COASTAL ZONE; WAVE; PROPAGATION; SEA AB Ocean acoustic tomography based on modal horizontal refraction/phase difference measurement has been developed in recent years. In this paper, potential opportunities for remotely sensing various interesting ocean dynamic structures by using the modal-horizontal-reaction tomography and modal-phase tomography are discussed, including: (1) retrieval of the 3-D structure of a mesoscale eddy, (2) monitoring of the transverse component of the current, (3) retrieval of ocean frontal parameters, and (4) acoustically diagnosing internal solitary waves (ISW) in the coastal zone. C1 Univ Colorado, Cooperat Inst Res Environm Sci, NOAA, ERL,Environm Technol Lab, Boulder, CO 80303 USA. RP Shang, EC (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, NOAA, ERL,Environm Technol Lab, Boulder, CO 80303 USA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 21 TC 2 Z9 5 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-396X J9 J COMPUT ACOUST JI J. Comput. Acoust. PD SEP PY 2000 VL 8 IS 3 BP 459 EP 471 DI 10.1016/S0218-396X(00)00030-3 PG 13 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA 362LY UT WOS:000089780500005 ER PT J AU Murray, BT Coriell, SR Chernov, AA McFadden, GB AF Murray, BT Coriell, SR Chernov, AA McFadden, GB TI The effect of oscillatory shear flow on step bunching SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE morphological stability; step motion; anisotropic kinetics; shear flow; floquet theory ID KINETIC SELF-STABILIZATION; MORPHOLOGICAL STABILITY; VICINAL FACE; BINARY ALLOY; GROWTH; SOLIDIFICATION; INSTABILITY; INTERFACE AB During crystal growth, an imposed shear Row at the crystal-fluid interface can alter the conditions for the onset of morphological instability. In previous work, we studied the effect of time-independent shear flows and anisotropic interface kinetics on the morphological stability of a crystal growing from supersaturated solution. The model assumes that growth is by the motion of elementary steps, which is treated by a macroscopic anisotropic kinetic law; morphological instability corresponds to the bunching of elementary steps. Predictions from linear stability theory indicate that a solution flowing above a vicinal face of a crystal can either enhance or prevent the development of step bunches, depending on the direction of the steady shear flow in relation to the direction of step motion: this is also observed in experiments. Here we extend the linear stability analysis to include the effect of an oscillatory shear flow on the morphological stability of a crystal growing from solution and present results for a model system for a range of oscillatory shear rate amplitudes and frequencies both with and without a steady shear component. In the presence of a steady shear flow, modulation can either stabilize or destabilize the system, depending on the modulation amplitude and frequency. Numerical solutions of the linearized Navier-Stokes and diffusion equations and an approximate analytical treatment Show that the flow oscillations weakens both the stabilization and destabilization induced by steady-state flow. This weakening comes from mixing of solution above the perturbed interface and a modification to the phase shift between the interface perturbation wave and the corresponding concentration and flow waves. Optimal values of modulation frequency and amplitude are found when the steady flow is destabilizing. (C) 2000 Elsevier Science B.V. AII rights reserved. C1 SUNY Binghamton, Dept Engn Mech, Binghamton, NY 13902 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Space Res Assoc, Huntsville, AL 35806 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35806 USA. RP Murray, BT (reprint author), SUNY Binghamton, Dept Engn Mech, Binghamton, NY 13902 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 16 TC 14 Z9 16 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 2000 VL 218 IS 2-4 BP 434 EP 446 DI 10.1016/S0022-0248(00)00566-2 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 358UH UT WOS:000089575200038 ER PT J AU Berejikian, BA Tezak, EP LaRae, AL AF Berejikian, BA Tezak, EP LaRae, AL TI Female mate choice and spawning behaviour of chinook salmon under experimental conditions SO JOURNAL OF FISH BIOLOGY LA English DT Article DE courtship behaviour; mate choice; Pacific salmon; intersexual communication ID TROUT ONCORHYNCHUS-MYKISS; ATLANTIC SALMON; PACIFIC SALMON; SOCKEYE-SALMON; REPRODUCTIVE-BEHAVIOR; BREEDING COMPETITION; SEXUAL SELECTION; MATURE MALE; BODY-SIZE; KISUTCH AB After spawning their first nest, female chinock salmon Oncorhynchus tshawytscha paired with small males (c. 46% of Female weight) spent an average of 16.2 h between spawning of successive nests compared with 9.6 h for females paired with large males (c. 112% of female weight) (P<0.05). Neither frequencies of female nest construction behaviours (digging and probing) nor male courtship behaviour (crossovers and quivers) differed between large- and small-male pairs. Male quivering frequencies were correlated significantly with female digging and probing frequencies, whereas the crossover frequencies were not. It is suggested that delayed spawning by females in the presence of relatively small males is a primary mechanism by which females in the genus Oncorhynchus exhibit mate choice. C1 Natl Marine Fisheries Serv, Resource Enhancement & Utlizat Technol Div, Manchester Res Stn, Manchester, WA 98535 USA. Pacific State Marine Fisheries Commiss, Gladstone, OR 97027 USA. RP Berejikian, BA (reprint author), Natl Marine Fisheries Serv, Resource Enhancement & Utlizat Technol Div, Manchester Res Stn, POB 130, Manchester, WA 98535 USA. NR 41 TC 50 Z9 50 U1 2 U2 12 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD SEP PY 2000 VL 57 IS 3 BP 647 EP 661 DI 10.1111/j.1095-8649.2000.tb00266.x PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 355UD UT WOS:000089406200008 ER PT J AU Hoff, GR Buckley, TW Drazen, JC Duncan, KM AF Hoff, GR Buckley, TW Drazen, JC Duncan, KM TI Biology and ecology of Nezumia liolepis and N-stelgidolepis from the west coast of North America SO JOURNAL OF FISH BIOLOGY LA English DT Article DE Nezumia; grenadier; macrouridae; deep sea fish; age and growth; life history ID MACROURID FISH; PACIFIC; STRATEGIES; GROWTH; SLOPE; SEA AB Nezumia liolepis and Nezumia stelgidolepis were collected during a National Marine Fisheries Service 1997 groundfish survey along the pacific coast of North America. Bottom trawling was conducted From 188 to 1260 m depths. Nezumia liolepis were collected from 581 to 1247 m (3.4-5.7 degrees C) and N. stelgidolepis from 285 to 555 m (6.0-8.4 degrees C). The two species find distinct depth and temperature distributions and the majority of the specimens for each species came from narrow depth ranges. Nezumia stelgidolepis attains a larger pre-anal fin length (117 mm) than N. liolepis (83 mm), and age estimates from otolith ring counts indicate ages from 3 to 9 years for N. liolepis and 7 and 13 years for N. stelgidolepis from specimens collected. The gonads of N. liolepis were not reproductively active, and a single N. stelgidolepis possessed eggs of various sizes suggesting batch spawning. N. liolepis and N. stelgidolepis fed benthically, primarily on crustaceans such as amphipods, shrimp, mysids and polychaete worms. Although diet overlap was high, these two species appear to limit competition for resources by habitat separation. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Calif San Diego, Marine Biol Res Div, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Hoff, GR (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Drazen, Jeffrey/C-1197-2013 OI Drazen, Jeffrey/0000-0001-9613-3833 NR 41 TC 11 Z9 11 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD SEP PY 2000 VL 57 IS 3 BP 662 EP 680 DI 10.1006/jfbi.2000.1343 PG 19 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 355UD UT WOS:000089406200009 ER PT J AU Hoke, ME Jahncke, ML Silva, JL Hearnsberger, JO Chamul, RS Suriyaphan, O AF Hoke, ME Jahncke, ML Silva, JL Hearnsberger, JO Chamul, RS Suriyaphan, O TI Stability of washed frozen mince from channel catfish frames SO JOURNAL OF FOOD SCIENCE LA English DT Article DE catfish mince; lipids; frozen storage; rancidity; antioxidants ID STORAGE; SURIMI; HAKE; MACKEREL; LIFE AB Sodium citrate, sodium erythorbate, sodium citrate plus sodium erythorbate, sodium citrate plus sodium erythorbate, and polyphosphate were used in washed and unwashed channel catfish mince. Washing reduced (P less than or equal to 0.05) lipids and increased (P less than or equal to 0.05) Hunter 'L' value (lightness) of mince. Thiobarbituric reactive substances and free fatty-acid changes during frozen storage were reduced in the washed mince. Addition of antioxidants did not significantly improve the overall quality and shelf-life of the frozen mince. Washing did not have an effect on the fatty-acid composition of neutral and phospholipids in the mince. C1 Mississippi State Univ, Mississippi Agr & Forestry Expt Stn, Dept Food Sci & Technol, Mississippi State, MS 39762 USA. Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, Pascagoula, MS USA. RP Silva, JL (reprint author), Mississippi State Univ, Mississippi Agr & Forestry Expt Stn, Dept Food Sci & Technol, Mississippi State, MS 39762 USA. NR 45 TC 16 Z9 16 U1 0 U2 0 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 USA SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD SEP PY 2000 VL 65 IS 6 BP 1083 EP 1086 DI 10.1111/j.1365-2621.2000.tb09422.x PG 4 WC Food Science & Technology SC Food Science & Technology GA 370NR UT WOS:000165129600030 ER PT J AU Duewer, DL Richie, KL Reeder, DJ AF Duewer, DL Richie, KL Reeder, DJ TI RFLP band size standards: NIST Standard Reference Material (R) 2390 SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; DNA typing; data analysis; HaeIII; HinfI; D1S7; D2S44; D4S139; D5S110; D7S467; D7Z2; D8S358; D10S28; D14S13; D17S26; D17S79; DYZI; standard reference material ID DNA PROFILING MEASUREMENTS AB The procedural standard for DNA profiling developed by the U.S. advisory board on DNA quality assurance methods mandates annual confirmation of forensic DNA measurement systems against an appropriate reference material supplied by or traceable to the National Institute of Standards and Technology (NIST). NIST Standard Reference Material(R) (SRM(R)) 2390 is a suitable and appropriate standard for HaeIII restriction enzyme-based restriction fragment length polymorphism (RFLP) profiling systems. Originally issued in 1992, an among-laboratory SRM 2390 recertification study was initiated in 1997. Using data provided by the 20 state, local, or commercial forensic laboratory participants, quantitative band sizes values (expected mean values and associated bivariate tolerance intervals) are established for two different source DNAs (female cell line K562 and healthy male "TAW") for genetic loci D1S7, D2S44, D4S139, D5S110, D10S28, and D17S79. Methods for validating an RFLP measurement system, validating a control material or other secondary standard, and for tracing a particular set of RFLP measurements to NIST SRM 2390 are described in detail. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. NIST, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Reeder, DJ (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, 100 Bur Dr,Stop 8311, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 19 TC 6 Z9 7 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD SEP PY 2000 VL 45 IS 5 BP 1093 EP 1105 PG 13 WC Medicine, Legal SC Legal Medicine GA 353GY UT WOS:000089267500020 PM 11005187 ER PT J AU Duewer, DL Gary, KT Reeder, DJ AF Duewer, DL Gary, KT Reeder, DJ TI RFLP band size standards: Cell line K562 values from 1991 to 1997 proficiency studies SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; DNA typing; data analysis; HaeIII; HinfI; D1S7; D1S339; D2S44; D2S92; D4S139; D4S163; D5S43; D5S110; D6S132; D7S21; D7S22; D7S467; D7Z2; D8S358; D10S28; D12S11; D14S13; D16S85; D16S309; D17S26; D17S79; K562 DNA; control; proficiency tests ID DNA PROFILING MEASUREMENTS; MEASUREMENT ERRORS; FRAGMENT-LENGTH; MATCH CRITERIA; CHROMOSOME AB Cell line K562 is the defacto forensic control material for forensic restriction fragment length polymorphism (RFLP) DNA profiling in the U.S. Fifty-one proficiency tests conducted from 1991 through 1997 enable a detailed description of RFLP measurement performance during this period. Sufficient data are available to define reference distributions for all commonly utilized and many less commonly reported genetic loci, for both HaeIII- and HinfI-based RFLP systems. The average measured size of HaeIII locus D1S7 and D5S110 bands has varied slightly over time; while relatively small, these temporal changes add to the overall interlaboratory measurement uncertainty. The characteristic standard deviation for HinfI RFLP system measurements has a nearly identical dependence on expected band size as does the standard deviation for Haem measurements. The ellipsoidal distance, K, is suggested for use as an RFLP data quality metric; the critical threshold value that on average excludes 1% of plausibly valid proficiency data for a given polymorphic locus is K-1% = 14.2. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. NIST, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Reeder, DJ (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, 100 Bur Dr,Stop 8311, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 25 TC 3 Z9 3 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD SEP PY 2000 VL 45 IS 5 BP 1106 EP 1118 PG 13 WC Medicine, Legal SC Legal Medicine GA 353GY UT WOS:000089267500021 PM 11005188 ER PT J AU Kiffney, PM Bull, JP AF Kiffney, PM Bull, JP TI Factors controlling periphyton accrual during summer in headwater streams of southwestern British Columbia, Canada SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article ID COASTAL RAINFOREST STREAM; AUTOTROPHIC PRODUCTION; NUTRIENT BUDGETS; LIGHT LIMITATION; VANCOUVER-ISLAND; RESPONSES; ECOSYSTEM; BIOMASS; CANOPY AB In headwater coastal streams of southwestern British Columbia, previous research suggested that light limited periphyton growth and abundance of grazing invertebrates. Logging along a reach of stream allowed us to further examine the importance of light, as well as other abiotic factors, in regulating stream periphyton and grazers. We placed unglazed ceramic tiles in three watershed, two of which served as controls. In the third watershed, we placed tiles in one reach that was newly harvested, as well as in an upstream, forested reach. Tires were placed in streams in late June and removed weekly over a six-week period for determination of periphyton chlorophyll a and ash-free dry mass. We also measured discharge, dissolved nitrate and phosphate, and counted the number of invertebrate grazers on each removed the weekly. Peak biomass, as chlorophyll a was reached on day 29 with alga biomass at the logged site (19 mu g m(-2)) seven to fourteen times higher than at the control sites. Stepwise, multiple Linear regression suggested that Light was the single best predictor explaining 64% of the variation in peak biomass of chlorophyll a. Although periphyton biomass on tiles was much higher in the clearcut reach, so was fine sediment. Inorganic mass entrapped in the periphyton mat was two to four times higher in the clearcut stream than at other sites. Grazer abundance was not related to periphyton biomass, but was negatively related to sediment levels. Our results are consistent with the hypothesis that grazer abundance was determined by sediment levels rather than alga biomass. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Environm Conservat Div, Seattle, WA 98112 USA. Univ British Columbia, Dept Forest Sci, Vancouver, BC V6T 1Z4, Canada. RP Kiffney, PM (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 46 TC 27 Z9 28 U1 1 U2 13 PU OIKOS PUBL INC PI LA CROSSE PA PO BOX 2558, LA CROSSE, WI 54601 USA SN 0270-5060 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD SEP PY 2000 VL 15 IS 3 BP 339 EP 351 DI 10.1080/02705060.2000.9663752 PG 13 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 343PB UT WOS:000088709800006 ER PT J AU Harrison, DE Vecchi, GA Weisberg, RH AF Harrison, DE Vecchi, GA Weisberg, RH TI Eastward surface jets in the central equatorial Pacific, November 1991-March 1992 SO JOURNAL OF MARINE RESEARCH LA English DT Article ID CENTRAL TROPICAL PACIFIC; EL-NINO; SOUTHERN OSCILLATION; OCEAN; MODEL; TEMPERATURE; VARIABILITY; WINDS; FLUX AB The central equatorial Pacific typically has westward surface and near-surface flow, interrupted by periods of eastward flow. The processes that may have been responsible for two periods of eastward flow during the 1991-92 El Nino between October 1991 and March 1992 are explored here, based on realistic hindcasts from a high-vertical resolution ocean general circulation model. The model balances indicate that the November-December 1991 surface trapped jet is fully nonlinear, and both wind stress and horizontal pressure gradient forcing are significant. The January-February 1992 jet is less strongly nonlinear. Both jets are strongly affected by local and remote westerly wind event forcing. Linear dynamics are not consistent with the model balances. We note that the mid-November to early December 1991 jet plausibly created the vertical salinity gradient that was observed in late December 1991. Although this salinity gradient can contribute to the maintenance of a vertically sheared eastward flow, it does not appear to have been fundamental in the creation of the two jets observed during this period. Accurate sampling of this region during periods of high variability requires frequent measurements. Local dynamics arrays with high vertical resolution current profiles, from the surface to beneath the Equatorial Undercurrent, are critical to the advancement of our understanding of equatorial dynamics, to evaluating the skill of our numerical models, and to accurate simulation and state estimation for this fascinating area of the ocean. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, JISAO, Seattle, WA 98195 USA. Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Vecchi, Gabriel/A-2413-2008; Harrison, Don/D-9582-2013 OI Vecchi, Gabriel/0000-0002-5085-224X; NR 32 TC 5 Z9 5 U1 0 U2 0 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD SEP PY 2000 VL 58 IS 5 BP 735 EP 754 DI 10.1357/002224000321358882 PG 20 WC Oceanography SC Oceanography GA 383JU UT WOS:000165880000004 ER PT J AU Lang, CI Sordelet, DJ Besser, MF Shechtman, D Biancaniello, FS Gonzalez, EJ AF Lang, CI Sordelet, DJ Besser, MF Shechtman, D Biancaniello, FS Gonzalez, EJ TI Quasicrystalline coatings: Thermal evolution of structure and properties SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID AL-PD-MN; QUASI-CRYSTALLINE COATINGS; ICOSAHEDRAL PHASE; FE; ALLOYS; SYSTEM; CONDUCTIVITY; DIAGRAM; STATE; ORDER AB Quasicrystals (QCs) are known to exhibit unique properties as a result of their unique quasiperiodic structure. Real quasicrystalline (QC) materials, however, may exhibit complex phase structures, and as a consequence, their properties may differ from expectations. In the present work, QC coatings of the Al-Cu-Fe, Al-Cu-Fe-Cr, and Al-Pd-Mn systems were prepared by a plasma spray process, followed by heat treatments in the range 500-800 degrees C. The phase structure and evolution of the coatings were evaluated, and thermal diffusivity, hardness, and friction coefficient were measured. The presence of quasicrystalline and crystalline phases and their influence on these properties is systematically considered for the first time. Broadly, the coatings exhibit the properties expected of QC materials, low thermal diffusivity, high hardness, and low coefficients of friction, but it is also shown that these properties can be sensitive to the phase structure of the coatings. This suggests that phase structure may be manipulated by heat treatment to optimize the properties of QC coatings. C1 Univ Cape Town, Dept Mat Engn, ZA-7700 Rondebosch, South Africa. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Lang, CI (reprint author), Univ Cape Town, Dept Mat Engn, ZA-7700 Rondebosch, South Africa. NR 41 TC 11 Z9 11 U1 3 U2 14 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2000 VL 15 IS 9 BP 1894 EP 1904 DI 10.1557/JMR.2000.0275 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800009 ER PT J AU Hurley, DC Balzar, D Purtscher, PT AF Hurley, DC Balzar, D Purtscher, PT TI Nonlinear ultrasonic assessment of precipitation hardening in ASTM A710 steel SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ACOUSTIC HARMONIC-GENERATION; PARAMETER; MATRIX; MISFIT AB We investigated several specimens of ASTM A710 steel containing copper-rich precipitates with variations in the final aging treatment. X-ray diffraction line-broadening and small-angle neutron-scattering experiments revealed the existence of the precipitates and associated coherency strain. We determined the nonlinear ultrasonic parameter beta for each specimen by harmonic-generation experiments and measured the ultrasonic longitudinal velocity upsilon(L) and attenuation alpha(L). Although upsilon(L) and or, showed no consistent trends, beta increased with increasing strain. This correlation is compared to a microstructural model for harmonic generation that includes a contribution from precipitate-pinned dislocations. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Hurley, DC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 23 TC 20 Z9 22 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2000 VL 15 IS 9 BP 2036 EP 2042 DI 10.1557/JMR.2000.0292 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800026 ER PT J AU Lee, SW Chae, HB Park, DS Choa, YH Niihara, K Hockey, BJ AF Lee, SW Chae, HB Park, DS Choa, YH Niihara, K Hockey, BJ TI Thermal conductivity of unidirectionally oriented Si3N4w/Si3N4 composites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SINTERED SILICON-NITRIDE; MICROSTRUCTURE; SI3N4 AB beta-silicon nitride whiskers were aligned unidirectionally in silicon nitride sintered with 2 wt% Al2O3 and 6 wt% Y2O3. It was be densified by the Gas Pressure Sintering (GPS) method. Thermal conductivity of the sintered body with different amount of beta- silicon nitride whiskers was measured by the direct contact method from 298 K to 373 K. This unidirectionally oriented beta-silicon nitride whiskers grew into the large elongated grains, and improved also the thermal conductivity. The amount of beta-silicon nitride whiskers changed the microstrcuture, which changed the thermal conductivity. (C) 2000 Kluwer Academic Publishers. C1 Sun Moon Univ, Dept Mat Engn, Asan 336840, South Korea. Sunchunhyang Univ, Dept Phys, Asan 336840, South Korea. Korea Inst Machinery & Mat, Changwon 641010, South Korea. Osaka Univ, ISIR, Osaka 5670047, Japan. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lee, SW (reprint author), Sun Moon Univ, Dept Mat Engn, Asan 336840, South Korea. RI Choa, Yongho/D-3625-2011 NR 18 TC 8 Z9 11 U1 0 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD SEP PY 2000 VL 35 IS 18 BP 4487 EP 4493 DI 10.1023/A:1004807516791 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 348KL UT WOS:000088984000001 ER PT J AU Ohashi, N Hougen, JT AF Ohashi, N Hougen, JT TI Approximate selection rules for vertical bar K vertical bar=1-0 and 1-1 tunneling-rotation transitions in the methanol dimer SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article AB Approximate K = 0 and \K\ = 1 tunneling-rotation eigenfunctions for the four A, four E, and one G symmetry species present in the methanol dimer, derived from molecular parameters obtained previously from a least-squares fit to transition frequencies involving K = 0 and 1 levels, are used to clarify some apparent contradictions associated with traditional b- and c-type transition designations in the E and G tunneling-rotational states of this dimer. These approximate eigenfunctions also predict strong and weak line intensities which are consistent with the pattern of strong a-, b-, and c-type transitions observed, thus supporting our previous separate K-state analysis based only on energy level differences. Some of the predicted weaker \K\ = 1 a-type transitions should be experimentally observable with more signal averaging. (C) 2000 Academic Press. C1 Kanazawa Univ, Fac Sci, Dept Phys, Kanazawa, Ishikawa 9201192, Japan. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Ohashi, N (reprint author), Kanazawa Univ, Fac Sci, Dept Phys, Kanazawa, Ishikawa 9201192, Japan. NR 3 TC 2 Z9 2 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 2000 VL 203 IS 1 BP 170 EP 174 DI 10.1006/jmsp.2000.8153 PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347WM UT WOS:000088952200021 ER PT J AU Glotzer, SC AF Glotzer, SC TI Spatially heterogeneous dynamics in liquids: insights from simulation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID GLASS-FORMING LIQUIDS; MODE-COUPLING-THEORY; SUPERCOOLED ORTHO-TERPHENYL; INTERMEDIATE SCATTERING FUNCTION; HYPERNETTED-CHAIN APPROXIMATION; TRANSLATION-ROTATION PARADOX; ANOMALOUS LIGHT-SCATTERING; LENNARD-JONES MIXTURE; MOLECULAR-DYNAMICS; STRUCTURAL RELAXATION AB In this paper, review of recent theoretical and simulation work on dynamical heterogeneity and correlated particle motion in glass-forming liquids and polymers is presented. Evidence for increasing mobility fluctuations in these systems with decreasing temperature, and the relationship between dynamical heterogeneity and decoupling of diffusion and structural relaxation is described. The relationship between dynamical heterogeneity, string-like collective motion, the clustering of strings, and mode-coupling theory is briefly discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RP Glotzer, SC (reprint author), NIST, Div Polymers, Room A311,Mat Bldg 223, Gaithersburg, MD 20899 USA. NR 119 TC 310 Z9 312 U1 0 U2 48 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 342 EP 355 DI 10.1016/S0022-3093(00)00225-8 PG 14 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300047 ER PT J AU Park, YS Sohn, HY Butt, DP AF Park, YS Sohn, HY Butt, DP TI Thermal removal of gallium from gallia-doped ceria SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID REDUCTION AB The potential for removing gallium from Ga-doped CeO2-x by thermal means was studied for the purpose of assessing gallium removal from PuO2-x. The latter is of interest to those considering the storage or use of weapon-grade Pu, for example as a mixed oxide fuel component. Experiments were done by varying temperature, gas composition, exposure time, sample size, particle size, and gas flow rate. The kinetics of gallium removal were assessed through measurements of weight change, scanning electron microscopy, and chemical analyses. Results suggest that the gallium level can be reduced significantly by thermal treatments in Ar-6% H-2. Gallium species segregate to grain boundaries because of the low solubility of Ga2O3 in CeO2. The kinetics and microstructural observations suggest that both gaseous and solid-state diffusion of gallium species are important for the removal of gallium. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Utah, Dept Met Engn, Salt Lake City, UT 84112 USA. RP Park, YS (reprint author), US Dept Commerce, Natl Inst Stand & Technol, MS 8250, Gaithersburg, MD 20899 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 26 TC 15 Z9 15 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2000 VL 280 IS 3 BP 285 EP 294 DI 10.1016/S0022-3115(00)00064-7 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 343XJ UT WOS:000088727500004 ER PT J AU Archer, DG AF Archer, DG TI Thermodynamic properties of the NaNO3+H2O system SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE activity coefficient; aqueous; enthalpy; Gibbs energy; heat capacity; osmotic coefficient; sodium nitrate; solubility; thermodynamics; vapor pressure ID ACTIVITY-COEFFICIENTS; HEAT-CAPACITIES; SODIUM-NITRATE; SUPERCOOLED STATES; AQUEOUS-SOLUTIONS; VAPOR-PRESSURES; NACL+H2O SYSTEM; WATER; TEMPERATURES; 25-DEGREES-C AB New equations that describe the thermodynamic properties of the NaNO3 + H2O system were obtained from previously published measurements for this system. The measured values included in the fitted equations spanned the range of temperatures of approximately 236-425 K for NaNO3(aq) and 16-548 K for NaNO3(cr). New equations and/or values for the following properties are given in the present work: (1) thermal properties of NaNO3(cr) from 0 K to near the lambda transition, 548.6 K, (2) the change in chemical potential for both NaNO3 and H2O in NaNO3(aq) as a function of temperature, and molality, valid from 236 to 425 K, and the molality range of 0 mol (.) kg(-1) to the lesser of the saturation molality or 25 mol (.) kg(-1), and (3) standard-state properties for the aqueous solution process. (C) 2001 by the U.S. Secretary of Commerce on behalf of the United States, All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Proper Div, Gaithersburg, MD 20899 USA. RP Archer, DG (reprint author), Natl Inst Stand & Technol, Phys & Chem Proper Div, Gaithersburg, MD 20899 USA. NR 97 TC 34 Z9 34 U1 0 U2 12 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 2000 VL 29 IS 5 BP 1141 EP 1156 DI 10.1063/1.1329317 PG 16 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 425MH UT WOS:000168294200003 ER PT J AU Sloyan, BM Rintoul, SR AF Sloyan, BM Rintoul, SR TI Estimates of area-averaged diapycnal fluxes from basin-scale budgets SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SOUTH-ATLANTIC OCEAN; WESTERN-BOUNDARY CURRENT; INDIAN-OCEAN; DEEP-WATER; HYDROGRAPHIC SECTION; BOTTOM WATER; INVERSE METHODS; PACIFIC-OCEAN; WORLD OCEAN; CIRCULATION AB Estimates of area-averaged diapycnal fluxes for the southern oceans are derived from basin-scale budgets of mass, heat, and salt using a box inverse model. The diapycnal fluxes are found to be significant terms in the isopycnal budgets of mass, heat, and salt. Dense water entering the subtropical Indian and Pacific basins from the south is returned below the thermocline as less dense deep water. In the Southern Ocean deep water is converted to denser jeep and bottom water. Water properties at intermediate depth are substantially modified by diapycnal fluxes of heat and salt, but the modification of intermediate water is not solely driven by interior mixing. The inferred fluxes help explain the changes in temperature-salinity curves observed across each basin, and they are consistent with our understanding of the overall three-dimensional circulation of the Southern Ocean. The fact that area-averaged diapycnal fluxes can be determined from basin-scale budgets using a suitably designed inverse model is encouraging: similar methods applied to the high-quality measurements collected during the World Ocean Circulation Experiment promise to provide the first global maps of diapycnal fluxes derived from ocean observations. C1 Univ Tasmania, Antarctic Cooperat Res Ctr, Hobart, Tas, Australia. Univ Tasmania, Inst Antarctic & So Ocean Studies, Hobart, Tas 7001, Australia. CSIRO, Div Marine Res, Hobart, Tas, Australia. RP Sloyan, BM (reprint author), NOAA, Pacific Marine Environm Lab, OCRD, 7600 Sand Point Way Ne,Bldg 3, Seattle, WA 98115 USA. RI Rintoul, Stephen /A-1471-2012; Sloyan, Bernadette/N-8989-2014 OI Rintoul, Stephen /0000-0002-7055-9876; NR 70 TC 42 Z9 43 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2000 VL 30 IS 9 BP 2320 EP 2341 DI 10.1175/1520-0485(2000)030<2320:EOAADF>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA 361PY UT WOS:000089732500011 ER PT J AU Gupta, AK Damm, T Charagundla, SR Presser, C AF Gupta, AK Damm, T Charagundla, SR Presser, C TI Role of oxygen-enriched atomization in kerosene spray flames SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID DROPLET TRANSPORT AB The effect of oxygen enrichment to the atomization air is examined here in a twin-fluid atomizer. A commercially available solid-cone, air-assist atomizer was used in which the atomization airstream was enriched to contain a volume fraction of 35 and 45% oxygen in nitrogen. The results are compared with the baseline case of 21% O-2 because air is the most commonly used mode of operation for twin-fluid atomizers. Data were obtained on droplet size, number density, and velocity at several spatial locations in the spray dames using a two-component phase Doppler interferometer, The global features of the spray flames, recorded photographically, were affected dramatically by oxygen enrichment of the atomization air Specifically, the flame luminosity increases, and the flame height and volume decreases with an increase in oxygen concentration supplied to the atomization air. A moderate increase in oxygen concentration produced a whitish color high-temperature violent combustion zone near the nozzle exit. In addition, dames with oxygen-enriched atomization air reduced the number of unburned droplets escaping the dame plume into the surrounding environment. This observation was supported by the phase Doppler measurements in which droplet mean size and velocity increased and droplet number density decreased as a result of enhanced droplet vaporization. The results suggest that oxygen enrichment of the atomization air provides a significant improvement to the initial mixing between the reactants immediately downstream of the nozzle exit. This improvement, in turn, influences droplet vaporization and transport, dame stability, and combustion intensity. C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Gupta, AK (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. NR 15 TC 1 Z9 2 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2000 VL 16 IS 5 BP 845 EP 852 DI 10.2514/2.5650 PG 8 WC Engineering, Aerospace SC Engineering GA 354NC UT WOS:000089335700016 ER PT J AU King, LB Gallimore, AD AF King, LB Gallimore, AD TI Ion-energy diagnostics in the plasma exhaust plume of a hall thruster SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Of primary concern with the integration of Hall thrusters oil conventional satellite designs is the possible damaging effect of high-energy exhaust ions impinging upon spacecraft surfaces. This paper reports on measurements of plasma ion-energy distributions within the plume of an SPT-100 Hall thruster using a custom-designed molecular-beam mass spectrometer. With this instrument ion energy was measured over a complete 360-deg circumference about the thruster at a radius of 0.5 m from the exit plane and over a total inclusive are of 260 deg at 1.0-m radius. These data uncovered the existence of high-energy ions departing the thruster at angles exceeding 90 deg from the thrust vector and continuing well into the backflow region of the plume. Through an analysis of the energy structure, the evidence of charge-exchange collisions occurring between plume ions and background neutrals was documented; such collisions produced anomalous distributions of ions having voltages greater than that applied to the thruster discharge. C1 Univ Michigan, Dept Aerosp Engn, Plasmadynam & Elect Prop Lab, Ann Arbor, MI 48105 USA. RP King, LB (reprint author), Natl Inst Stand & Technol, Div Time & Frequency 847, 325 Broadway, Boulder, CO 80303 USA. NR 19 TC 11 Z9 11 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2000 VL 16 IS 5 BP 916 EP 922 DI 10.2514/2.5660 PG 7 WC Engineering, Aerospace SC Engineering GA 354NC UT WOS:000089335700025 ER PT J AU Alfassi, ZB AF Alfassi, ZB TI In-house absolute calibration of gamma-emitting radioactive voluminous samples: Detector setups using natural radionuclides SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID COINCIDENCE-SUMMING CORRECTIONS; RAY SPECTROMETRY AB A method for the absolute calibrations of gamma-rays spectrometers for voluminous samples using natural radionuclides is suggested. The method is based on relative calibration with a solution of Th-232 salts and absolute calibration with K2CO3 or KCl. C1 Ben Gurion Univ Negev, Dept Nucl Engn, IL-84105 Beer Sheva, Israel. Natl Inst Stand & Technol, Div Ionizing Radiat, Gaithersburg, MD 20899 USA. RP Alfassi, ZB (reprint author), Ben Gurion Univ Negev, Dept Nucl Engn, IL-84105 Beer Sheva, Israel. NR 14 TC 8 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD SEP PY 2000 VL 245 IS 3 BP 561 EP 565 DI 10.1023/A:1006761327365 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 360NE UT WOS:000089673500016 ER PT J AU Hurly, JJ Moldover, MR AF Hurly, JJ Moldover, MR TI Ab initio values of the thermophysical properties of helium as standards SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE diffusion coefficient; helium; intermolecular potential; second virial; thermal conductivity; thermal diffusion factor; thermophysical standards; transport properties; viscosity ID POTENTIAL-ENERGY CURVE; CORRELATED GAUSSIAN FUNCTIONS; 2ND VIRIAL-COEFFICIENT; THERMAL-CONDUCTIVITY; NOBLE-GASES; DISPERSION COEFFICIENTS; ABSOLUTE DETERMINATION; TEMPERATURE-RANGE; ROOM-TEMPERATURE; DIMER AB Recent quantum mechanical calculations of the interaction energy of pairs of helium atoms are accurate and some include reliable estimates of their uncertainty. We combined these ab initio results with earlier published results to obtain a helium-helium interatomic potential that includes relativistic retardation effects over all ranges of interaction. From this potential, we calculated the thermophysical properties of helium, i.e., the second virial coefficients, the dilute-gas viscosities, and the dilute-gas thermal conductivities of He-3, He-4, and their equimolar mixture from 1 K to 10(4) K. We also calculated the diffusion and thermal diffusion coefficients of mixtures of He-3 and He-4. For the pure fluids, the uncertainties of the calculated values are dominated by the uncertainties of the potential; for the mixtures, the uncertainties of the transport properties also include contributions from approximations in the transport theory. In all cases, the uncertainties are smaller than the corresponding experimental uncertainties; therefore, we recommend the ab initio results be used as standards for calibrating instruments relying on these thermophysical properties. We present the calculated thermophysical properties in easy-to-use tabular form. C1 Natl Inst Stand & Technol, Fluid Sci Grp, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Hurly, JJ (reprint author), Natl Inst Stand & Technol, Fluid Sci Grp, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. EM john.hurly@nist.gov; michael.moldover@nist.gov RI Moldover, Michael/E-6384-2013 NR 75 TC 111 Z9 114 U1 0 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2000 VL 105 IS 5 BP 667 EP 688 DI 10.6028/jres.105.054 PG 22 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200001 PM 27551630 ER PT J AU Shaw, PS Larason, TC Gupta, R Brown, SW Lykke, KR AF Shaw, PS Larason, TC Gupta, R Brown, SW Lykke, KR TI Improved near-infrared spectral responsivity scale SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE cryogenic radiometer; detector standards; electrical substitution; IR detector; near infrared; radiometry; responsivity ID ACCURACY CRYOGENIC RADIOMETER; ULTRAVIOLET RADIOMETRY; NATIONAL-INSTITUTE; CALIBRATION; DETECTORS; STANDARDS; RADIATION; FACILITY; NIST AB A cryogenic radiometer-based system was constructed at the National Institute of Standards and Technology for absolute radiometric measurements to improve detector spectral power responsivity scales in the wavelength range from 900 nm to 1800 nm. In addition to the liquid-helium-cooled cryogenic radiometer, the system consists of a 100 W quartz-tungsten-halogen lamp light source and a 1 m single-grating monochromator for wavelength selection. The system was characterized and the uncertainty in spectral power responsivity measurements evaluated. A variety of photodetectors, including indium gallium arsenide photodiodes (InGaAs), germanium (Ge) photodiodes, and pyroelectric detectors, were subsequently calibrated. Over most of the spectral range, the spectral power responsivity of the photodetectors can be measured with a combined relative standard uncertainty of 0.4 % or less. This is more than a factor of two smaller than our previous capabilities, and represents a significant improvement in the near infrared (NIR) spectral power responsivity scale maintained at NIST. We discuss the characterization of the monochromator-based system and present results of photodetector spectral power responsivity calibrations. C1 Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Opt Sensor Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Phys Lab, Spectroradiometr Detector Measurement Calibrat Se, Gaithersburg, MD 20899 USA. RP Shaw, PS (reprint author), Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Opt Sensor Grp, Gaithersburg, MD 20899 USA. EM ping-shine.shaw@nist.gov; thomas.larason@nist.gov; rajeev.gupta@nist.gov; steven.brown@nist.gov; keith.lykke@nist.gov NR 14 TC 12 Z9 12 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 SEP-OCT PY 2000 VL 105 IS 5 BP 689 EP 700 DI 10.6028/jres.105.055 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200002 PM 27551631 ER PT J AU O'Brien, M Lamperti, P AF O'Brien, M Lamperti, P TI Comparison of the NIST and NPL air kerma standards used for X-ray measurements between 10 kV and 80 kV SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE air kerma; free-air ionization chamber; primary standard; reference radiation qualities AB A direct comparison was made between the air kerma primary standards used for the measurements of low-energy x rays at the National Institute of Standards and Technology (NIST) and the National Physical Laboratory (NPL). The comparison was conducted at the NPL using NPL reference radiation qualities between 10 kV and 80 kV. The results show the primary air-kerma standards to agree within 0.6 % of their values for beam qualities up to 80 kV. C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Dosimetry & Interact Grp, Gaithersburg, MD 20899 USA. Natl Phys Lab, Ctr Ionising Radiat Metrol, Teddington, Middx, England. RP O'Brien, M (reprint author), Natl Inst Stand & Technol, Ionizing Radiat Div, Dosimetry & Interact Grp, Gaithersburg, MD 20899 USA. EM michelle.obrien@nist.gov; paul.lamperti@nist.gov NR 6 TC 2 Z9 2 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2000 VL 105 IS 5 BP 701 EP 707 DI 10.6028/jres.105.056 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200003 PM 27551632 ER PT J AU Munro, RG AF Munro, RG TI Material properties of titanium diboride SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE evaluated data; material properties; mechanical properties; physical properties; thermal properties; titanium diboride ID MECHANICAL-PROPERTIES; TIB2; CERAMICS; STRENGTH; SINTERABILITY; COMPOSITES; ADDITIVES; BEHAVIOR; ALUMINA; NICKEL AB The physical, mechanical, and thermal properties of polycrystalline TiB2 are examined with an emphasis on the significant dependence of the properties on the density and grain size of the material specimens. Using trend analysis, property relations, and interpolation methods, a coherent set of trend values for the properties of polycrystalline TiB2 is determined for a mass fraction of TiB2 greater than or equal to 98 %, a density of (4.5+/-0.1) g/cm(3), and a mean grain size of (9+/-1) mum. C1 Natl Inst Stand & Technol, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Munro, RG (reprint author), Natl Inst Stand & Technol, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. EM ronald.munro@nist.gov NR 55 TC 303 Z9 310 U1 8 U2 62 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2000 VL 105 IS 5 BP 709 EP 720 DI 10.6028/jres.105.057 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200004 PM 27551633 ER PT J AU Hakegard, JE AF Hakegard, JE TI Coding and modulation for LMDS and analysis of the LMDS channel SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE co-channel interference; Ka-band channel; LMDS; modem design; non-linear HPA; pragmatic TCM ID PUNCTURED CONVOLUTIONAL-CODES; PREDISTORTION; AMPLIFIERS AB Local Multipoint Distribution Service (LMDS) has the potential to become a viable alternative to coaxial cable, fiber and other wired and wireless technologies providing "last mile" communication services. A major obstacle, however, is the high equipment cost. While for example cable modems supporting two-way services are available for $200 to $300, LMDS modem providing similar services will cost over $1000. The major cost driver of LMDS equipment is the radio frequency (RF) unit, as Ka-band technology still is quite expensive. The modem design must minimize the overall architecture cost, and low-cost modems requiring an expensive architecture should not be used. The channel characteristics of LMDS systems are very different from those of fiber, coaxial cable, and lower frequency wireless links, major channel impairments being non-linear high power amplifier (HPA), high phase noise and high co-channel interference. Modems should therefore be developed specifically for LMDS systems. This report deals with the choice of coding and modulation schemes, the LMDS channel, and how the channel impairments should be overcome by digital signal processing algorithms. C1 Natl Inst Stand & Technol, Informat Technol Lab, Adv Network Technol Div, Wireless Commun Technol Grp, Gaithersburg, MD 20899 USA. RP Hakegard, JE (reprint author), SINTEF, Telecom & Informat, N-7034 Trondheim, Norway. EM jan.e.hakegard@informatics.sintef.no NR 36 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2000 VL 105 IS 5 BP 721 EP 754 DI 10.6028/jres.105.058 PG 34 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200005 PM 27551634 ER PT J AU Beers, JS Penzes, WB AF Beers, JS Penzes, WB TI The NIST length scale interferometer (vol 104, pg 225, 1999) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Correction C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Beers, JS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2000 VL 105 IS 5 BP 779 EP 779 DI 10.6028/jres.105.060 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 377UT UT WOS:000165545200007 PM 27551636 ER PT J AU Lee, KS Jung, YG Peterson, IM Lawn, BR Kim, DK Lee, SK AF Lee, KS Jung, YG Peterson, IM Lawn, BR Kim, DK Lee, SK TI Model for cyclic fatigue of quasi-plastic ceramics in contact with spheres SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COMPRESSIVE STRESS STATES; SILICON-NITRIDE; CRACK-GROWTH; STRENGTH DEGRADATION; HERTZIAN CONTACTS; MECHANICAL CHARACTERIZATION; POLYCRYSTALLINE CERAMICS; INDENTATION FRACTURE; BRITTLE SOLIDS; STRAIN CURVES AB A model of contact damage accumulation from cyclic loading with spheres and ensuing strength degradation in relatively tough, heterogeneous ceramics is developed. The damage takes the form of a quasi-plastic zone beneath the contact, consisting of an array of closed frictional shear faults with attendant "wing" microcracks at their ends. Contact fatigue takes place by attrition of the frictional resistance at the sliding fault interfaces, in accordance,vith an empirical degradation law, allowing the microcracks to extend. At large numbers of cycles or loads the microcracks coalesce, ultimately into radial cracks. Fracture mechanics relations for the strength degradation as a function of number of cycles and contact load are derived. Indentation-strength data from two well-studied coarse-grain quasi-plastic ceramics, a micaceous glass-ceramic and a silicon nitride, are used to evaluate the model. Comparative tests in static and cyclic contact loading confirm a dominant mechanical component in the fatigue. At the same time, the presence of water is shown to enhance the fatigue. The model accounts for the broader trends in the strength degradation data, and paves the way for consideration of key variables in microstructural design for optimum fatigue resistance, C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. Caterpillar Inc, Ctr Tech, Adv Mat Technol, Mossville, IL 61656 USA. RP Lee, KS (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Kim, Do Kyung/C-2039-2011 OI Kim, Do Kyung/0000-0001-9092-9427 NR 57 TC 29 Z9 29 U1 0 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2000 VL 83 IS 9 BP 2255 EP 2262 PG 8 WC Materials Science, Ceramics SC Materials Science GA 352EL UT WOS:000089201500018 ER PT J AU Bergeson, SD Baldwin, KGH Lucatorto, TB McIlrath, TJ Cheng, CH Eyler, EE AF Bergeson, SD Baldwin, KGH Lucatorto, TB McIlrath, TJ Cheng, CH Eyler, EE TI Doppler-free two-photon spectroscopy in the vacuum ultraviolet: helium 1(1)S-2(1)S transition SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID STATE LAMB SHIFT; GROUND-STATE; LASER SPECTROSCOPY; ATOMIC-HYDROGEN; HIGH-RESOLUTION; VUV RADIATION; GENERATION; FREQUENCY; AMPLIFICATION; DEUTERIUM AB We describe techniques for laser spectroscopy in the vacuum-UV (VUV) spectral region that combine high spectral resolution with high absolute accuracy. A nearly transform-limited nanosecond laser source at 120 nm is constructed with difference-frequency mixing. This source is used to perform the first, to our knowledge, Doppler-free VUV measurement. We measure the inherently narrow 1(1)S-2(1)S two-photon transition in atomic helium with a spectral resolution of 7 parts in 10(8) (180 MHz), the narrowest line width so far observed at such short wavelengths. Careful measurements of optical phase perturbations allow us to determine the absolute frequency of the line center to a fractional uncertainty of 1 part in 10(8). Improvements now in progress should reduce this uncertainty to 2 parts in 10(9). (C) 2000 Optical Society of America [S0740-3224(00)01009-2]. C1 Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Canberra, ACT 0200, Australia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Amer Phys Soc, College Pk, MD 20740 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Bergeson, SD (reprint author), Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. RI Baldwin, Kenneth/A-4928-2008; Bergeson, Scott/L-8959-2013 OI Baldwin, Kenneth/0000-0002-2043-5330; Bergeson, Scott/0000-0002-3124-9226 NR 37 TC 25 Z9 25 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 2000 VL 17 IS 9 BP 1599 EP 1606 DI 10.1364/JOSAB.17.001599 PG 8 WC Optics SC Optics GA 352RP UT WOS:000089231900017 ER PT J AU Ellefson, RE Miiller, AP AF Ellefson, RE Miiller, AP TI Recommended practice for calibrating vacuum gauges of the thermal conductivity type SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB This article describes and recommends various methods for calibration of thermal conductivity vacuum gauges in the pressure range of the order of 10(-1) Pa ( 10(-3) Torr) to an atmosphere and is one of a series published by the American Vacuum Society. It contains data from many sources and represents the opinions of a number of experts in the field. The text was developed by a sub-committee of the Recommended Practice Committee of the American Vacuum Society. The Thermal Conductivity Gauging Committee is made up of users and manufacturers of vacuum gauges who have a variety of experience in the practical use of thermal conductivity gauges. (C) 2000 American Vacuum Society. [S0734-2101(00)01505-0]. C1 Leybold Inficon Inc, E Syracuse, NY 13057 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ellefson, RE (reprint author), Leybold Inficon Inc, E Syracuse, NY 13057 USA. NR 18 TC 8 Z9 8 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2000 VL 18 IS 5 BP 2568 EP 2577 DI 10.1116/1.1286024 PG 10 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 356GD UT WOS:000089434800081 ER PT J AU Guyer, JE Tseng, WF Pellegrino, JG AF Guyer, JE Tseng, WF Pellegrino, JG TI Diffuse reflectance spectroscopy for in situ process monitoring and control during molecular beam epitaxy growth of InGaAs/AlGaAs pseudomorphic high electron mobility transistors SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID TEMPERATURE-MEASUREMENT; PERFORMANCE; HEMT AB We report the use of diffuse reflectance spectroscopy for active, closed-loop control of substrate temperature during the growth of a modulation doped heterostructure. Measurement and control of substrate temperature is a common difficulty for molecular beam epitaxy (MBE), as well as other semiconductor deposition techniques. To examine the effect of the temperature lag experienced during conventional MBE, we have grown identical pairs of GaAs/InGaAs/AlGaAs pseudomorphic high electron mobility transistors (pHEMTs). For one pHEMT in each pair, the input signal for substrate temperature control was the standard thermocouple (TC); fur the other, it was diffuse reflectance spectroscopy (DRS). Under TC control, an overshoot of up to 70 degreesC was observed during the temperature upramp following the lower-temperature deposition of the InGaAs layer. This overshoot was eliminated under DRS control. Temperature errors can lead to heterolayer changes such as segregation, desorption, and changes in dopant activation. [S0734-211X(00)01205-0]. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Guyer, JE (reprint author), Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RI Guyer, Jonathan/M-5165-2016 OI Guyer, Jonathan/0000-0002-1407-6589 NR 20 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 2000 VL 18 IS 5 BP 2518 EP 2522 DI 10.1116/1.1310660 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 365LB UT WOS:000089951800035 ER PT J AU Barrett, CB AF Barrett, CB TI World water crisis seeks engineering solutions SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Editorial Material C1 NOAA, Natl Weather Serv, Off Hydrol, Int Hydrol Technol Transfer Ctr, Silver Spring, MD 20910 USA. RP Barrett, CB (reprint author), NOAA, Natl Weather Serv, Off Hydrol, Int Hydrol Technol Transfer Ctr, 1325 East West Hwy, Silver Spring, MD 20910 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD SEP-OCT PY 2000 VL 126 IS 5 BP 268 EP 269 DI 10.1061/(ASCE)0733-9496(2000)126:5(268) PG 2 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA 347DX UT WOS:000088913100001 ER PT J AU Bishop, RE Torres, JJ Crabtree, RE AF Bishop, RE Torres, JJ Crabtree, RE TI Chemical composition and growth indices in leptocephalus larvae SO MARINE BIOLOGY LA English DT Article ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; HERRING CLUPEA-HARENGUS; EARLY LIFE-HISTORY; OTOLITH MICROSTRUCTURE; ANGUILLA-JAPONICA; JAPANESE EEL; DAILY INCREMENTS; AGE VALIDATION; FISHES; SIZE AB Leptocephali grow at extremely high rates (>1 mm d(-1)), but, unlike most fish larvae, leptocephali may remain in the plankton as larvae for several months before metamorphosing into the juvenile form. During their planktonic phase, leptocephali accumulate energy reserves in the form of glycosaminoglycans which are then expended along with lipid reserves to fuel metamorphosis. Otolith growth rates were determined using scanning electron microscopy for four species of leptocephali common in the Gulf of Mexico, Paraconger caudilimbatus (Poey, 1867), Ariosoma balearicum (Delaroche, 1809), Gymnothorax saxicola (Jordan and Davis, 1891), and Ophichthus gomesii (Castelnou, 1855). Proximate composition, RNA:DNA ratios and protein growth rates were examined with respect to mass, length and age. The leptocephalus growth strategy was strongly reflected in the growth indices. Mass (Y) in all four species increased with increasing age (X) according to the equation Y = aX(b), where a is a species-specific constant and 1.05 less than or equal to b < 2.40. The accumulation of acellular mass was evident in protein growth rates and RNA:DNA ratios, and was observed as a shift in increasing size from rapid growth in length to a greater increase in mass with age. These results suggest that the proportion of actively metabolizing tissue declines with size and is replaced by the metabolically inert energy depot: the glycosaminoglycans. Leptocephali can thus grow to large size very rapidly with minimal metabolic penalty, an unusual and successful developmental strategy. C1 Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. Natl Marine Fisheries Serv, SE Reg Off, St Petersburg, FL 33702 USA. RP Bishop, RE (reprint author), Univ S Florida, Dept Marine Sci, 140 7Th Ave S, St Petersburg, FL 33701 USA. NR 48 TC 27 Z9 29 U1 1 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD SEP PY 2000 VL 137 IS 2 BP 205 EP 214 DI 10.1007/s002270000362 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 357PY UT WOS:000089511100003 ER PT J AU Sabine, CL Wanninkhof, R Key, RM Goyet, C Millero, FJ AF Sabine, CL Wanninkhof, R Key, RM Goyet, C Millero, FJ TI Seasonal CO2 fluxes in the tropical and subtropical Indian Ocean SO MARINE CHEMISTRY LA English DT Article DE Indian ocean; carbon dioxide; sea surface; flux; biogeochemistry ID ATMOSPHERIC CARBON-DIOXIDE; ARABIAN-SEA; SURFACE SEAWATER; PARTIAL-PRESSURE; PACIFIC-OCEAN; SOUTH-PACIFIC; NITROUS-OXIDE; GAS-EXCHANGE; WORLD OCEAN; WATER AB Improved estimates of the variability in air-sea CO2 fluxes on seasonal and interannual time scales are necessary to help constrain the net partitioning of CO2 between the atmosphere, oceans and terrestrial biosphere. Few direct measurements of the carbon system have been made in the main Indian Ocean basin. In the mid 1990s, several global carbon measurement programs focused on the Indian Ocean, greatly increasing the existing carbon database for this basin. This study examines the combined surface CO2 measurements from three major US programs in the Indian Ocean: the global carbon survey cruises, conducted in conjunction with the World Ocean Circulation Experiment (WOCE), the NOAA Ocean-Atmosphere Carbon Exchange Study (OACES) Indian Ocean survey and the Joint Global Ocean Flux Study (JGOFS) Arabian Sea Process Study. These data are fit with multiparameter linear regressions as a function of commonly measured hydrographic parameters. These fits are then used with NCEP/NCAR reanalysis and Levitus 94 gridded values to evaluate the seasonal variability of surface seawater CO2 in the tropical and subtropical Indian Ocean and to estimate the magnitude of the Indian Ocean as a net sink for atmospheric CO2 The net annual flux for the Indian Ocean (north of 36 degrees S) was - 12.4 +/- 0.5 X 10(12) mol of carbon (equivalent to -0.15 Pg C) in 1995. The relatively small net flux results from the very different surface water pCO(2) distributions and seasonal variations in the northern and southern Indian Ocean. The equatorial and northern hemisphere regions have values that are generally above atmospheric values. During the S-W monsoon, pCO(2) values in the Arabian Sea coastal upwelling region are among the highest observed in the oceans. The upwelling is seasonal in nature, however, and only affects a relatively small area. The Indian Ocean equatorial region generally has values slightly above atmospheric. Unlike the Pacific and Atlantic Oceans, however, no clear equatorial upwelling signature was observed in 1995. The Southern Hemisphere Indian Ocean, which represents the largest region by area, generally has values below atmospheric. The strongest undersaturations are observed in the austral winter, with summer values reaching near or slightly above atmospheric. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Washington, Joint Inst Study Atmosphere & Ocean, NOAA, PMEL, Seattle, WA 98115 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Dept, Miami, FL 33149 USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Woods Hole Oceanog Inst, MC&G Dept, Woods Hole, MA 02543 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Sabine, CL (reprint author), Univ Washington, Joint Inst Study Atmosphere & Ocean, NOAA, PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM sabine@pmel.noaa.gov NR 54 TC 30 Z9 31 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD SEP PY 2000 VL 72 IS 1 BP 33 EP 53 DI 10.1016/S0304-4203(00)00064-5 PG 21 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 354TF UT WOS:000089345200003 ER PT J AU Miles, RB Grinstead, J Kohl, RH Diskin, G AF Miles, RB Grinstead, J Kohl, RH Diskin, G TI The RELIEF flow tagging technique and its application in engine testing facilities and for helium-air mixing studies SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE fluid flow velocity; mixing; turbulence; vorticity; transport; RELIEF flow tagging; Raman excitation; oxygen; oxygen laser-induced fluorescence; engine inlet monitoring; flow field monitoring; combustion diagnostics; mixing studies; turbulent studies ID VELOCITY-MEASUREMENT; VELOCIMETRY; O2 AB Raman excitation plus laser-induced electronic fluorescence (RELIEF) images the motion of oxygen molecules in air and other gas mixtures. This is accomplished by tagging oxygen molecules through vibrational excitation and imaging them after a short period of time by laser-induced electronic fluorescence. The vibrational lifetime of oxygen is sufficiently long and the signal sufficiently strong to allow this technique to be used over a wide range of how conditions, from low subsonic to hypersonic, and in a variety of gas mixtures including high humidity environments. The utilization of a molecular tagging technique such as this is critical for environments in which seeding is impossible or unreliable and for measurements in which a wide range of scales needs to be observed simultaneously. Two experiments which have been conducted at national laboratories in medium- to large-scale facilities are reported. At the Arnold Engineering Development Center, RELIEF was used to examine velocity in a 1 m diameter tunnel for applications in the area of engine testing. At the NASA Langley Research Center, RELIEF is being used to examine supersonic mixing of helium in air in a coaxial jet in association with studies of fuel-air mixing in hypersonic engines. These applications are two examples of the wide range of practical uses for this new technology. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ronald H Kohl & Associates, Tullahoma, TN 37388 USA. NASA, Langley Res Ctr, Hyperson Airbreathing Prop Branch, Hampton, VA 23681 USA. RP Princeton Univ, Dept Mech & Aerosp Engn, Room D-414 Engn Quadrangle,Olden St, Princeton, NJ 08544 USA. EM miles@princeton.edu; jhg@nist.gov; kohl@cafes.net; g.s.diskin@larc.nasa.gov NR 24 TC 31 Z9 31 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD SEP PY 2000 VL 11 IS 9 BP 1272 EP 1281 DI 10.1088/0957-0233/11/9/304 PG 10 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 354TB UT WOS:000089344800005 ER PT J AU Cziczo, DJ Thomson, DS Murphy, DM AF Cziczo, DJ Thomson, DS Murphy, DM TI In situ measurements and laboratory studies of meteoritic material in stratospheric aerosols. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A46 EP A46 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400063 ER PT J AU Toby, BH Khosrovani, N Dartt, CD Davis, ME Parise, JB AF Toby, BH Khosrovani, N Dartt, CD Davis, ME Parise, JB TI Structure-directing agents and stacking faults in the CON system: a combined crystallographic and computer simulation study SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article DE molecular sieve; zeolite; structure-directing agent; neutron diffraction; molecular modeling; stacking fault ID POWDER DIFFRACTION; ZEOLITE; MODEL AB To better understand the role of structure-directing agents (SDAs) in the formation of molecular sieves and how SDA cations can inhibit the growth of stacking faults, we determined the location of SDA cations in the molecular sieve CIT-1, a member of the CON family, using a combination of crystallography and forcefield-based computer simulations. A Monte Carlo docking algorithm was used to develop trial structural models, which were used as the starting point for structure determination from synchrotron X-ray and neutron powder diffraction data using Rietveld refinements. Our results demonstrate that the SDA cations site in a single location, but with two different orientations. Experimental and computer simulation results indicate that four SDA cations can pack in the pores of CIT-1, invalidating the Monte Carlo docking result, which predicts that only three can be accommodated. Forcefield minimization studies demonstrated clear differences between two SDA cations that can be used to produce CON and a third that does not, but failed to provide information about how stacking faults are inhibited in CIT-1 by one particular SDA. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. RP Toby, BH (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 14 TC 7 Z9 7 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-1811 J9 MICROPOR MESOPOR MAT JI Microporous Mesoporous Mat. PD SEP PY 2000 VL 39 IS 1-2 BP 77 EP 89 DI 10.1016/S1387-1811(00)00178-5 PG 13 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 354ZK UT WOS:000089361000008 ER PT J AU Helmerson, K Phillips, WD AF Helmerson, K Phillips, WD TI Cooling, trapping and manipulation of neutral atoms and Bose-Einstein condensates by electromagnetic fields SO MODERN PHYSICS LETTERS B LA English DT Article; Proceedings Paper CT 13th Physics Summer School on Bose-Einstein Condensation: From Atomic Physics to Quantum Fluids CY JAN 17-28, 2000 CL AUSTRALIAN NATL UNIV, CANBERRA, AUSTRALIA HO AUSTRALIAN NATL UNIV ID RESONANCE-RADIATION PRESSURE; PHOTON RECOIL ENERGY; OPTICAL MOLASSES; SODIUM ATOMS; DOPPLER LIMIT; LASER-LIGHT; ATTRACTIVE INTERACTIONS; BRAGG SCATTERING; MULTILEVEL ATOMS; MAGNETIC-FIELD AB We give a general discussion of the mechanical effects of light, and of laser cooling and trapping techniques. This is followed by a description of experiments in the manipulation of Bose-Einstein condensates with optical laser pulses. C1 Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Helmerson, K (reprint author), Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Helmerson, Kristian/E-3683-2013 NR 139 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD SEP PY 2000 VL 14 SU S BP 231 EP 280 DI 10.1142/S0217984900001567 PG 50 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 380YB UT WOS:000165730700008 ER PT J AU Lue, L Friend, DG Elliott, JR AF Lue, L Friend, DG Elliott, JR TI Critical compressibility factors for chain molecules SO MOLECULAR PHYSICS LA English DT Article ID POLYMER-SOLUTIONS; EQUATION; FLUIDS; STATE; SIMULATION; UNIVERSALITY; EQUILIBRIA AB For many proposed equations of state for fluids composed of chain-like molecules, the compressibility factor is related to the chain number concentration only through the total monomer concentration. For these theories, the virial coefficients do not scale correctly with the chain molecular weight in the long chain limit, which can lead to a poor description of the phase diagram. In addition, for equations of state that are analytical at the critical point, it is found that the critical compressibility factor approaches 1/3 in the limit of infinitely long chains, contrary to experimental trends. Appropriate scaling leads to the proper trend for the compressibility factor, as demonstrated with a simple equation. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Univ Akron, Dept Chem Engn, Akron, OH 44325 USA. RP Lue, L (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, M-S 838,325 Broadway, Boulder, CO 80303 USA. RI Lue, Leo/E-7846-2011; Elliott, J. Richard/K-2544-2016 OI Lue, Leo/0000-0002-4826-5337; NR 25 TC 14 Z9 14 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD SEP PY 2000 VL 98 IS 18 BP 1473 EP 1477 DI 10.1080/002689700417583 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 352KE UT WOS:000089213500010 ER PT J AU Askelson, MA Aubagnac, JP Straka, JM AF Askelson, MA Aubagnac, JP Straka, JM TI An adaptation of the Barnes filter applied to the objective analysis of radar data SO MONTHLY WEATHER REVIEW LA English DT Article ID ANALYSIS SCHEME; FIELDS; ERRORS; INTERPOLATION AB Spatial objective analysis is routinely performed in several applications that utilize radar data. Because of their relative simplicity and computational efficiency, one-pass distance-dependent weighted-average (DDWA) schemes that utilize either the Cressman or the Barnes filter are often used in these applications. The DDWA schemes that have traditionally been used do not, however directly account for two fundamental characteristics of radar data. These are 1) the spacing of radar data depends on direction and 2) radar data density systematically decreases with increasing range. A DDWA scheme based on an adaptation of the Barnes tilter is proposed. This scheme, termed the adaptive Barnes (A-B) scheme, explicitly takes into account radar data properties 1 and 2 above. Both theoretical and experimental investigations indicate that two attributes of the A-B scheme, direction-splitting and automatic adaptation to data density, may facilitate the preservation of the maximum amount of meaningful information possible within the confines of one-pass DDWA schemes. It is shown that in the idealized situation of infinite, continuous data and for an analysis in rectangular-Cartesian coordinates, a direction-splitting scheme does not induce phase shifts if the weight function is even in each direction. Moreover, for radar data that are infinite, collected at regular radial, azimuthal, and elevational increments, and collocated with analysis points, the direction-splitting design of the A-B filter removes gradients in the analysis weights. This is a beneficial attribute when considering the treatment of gradient information of rectangular Cartesian data by an analysis system because then postanalysis gradients equal the analysis of gradients. The direction-splitting design of the A-B filter is unable, however, to circumvent the impact of the varying physical distances between adjacent measurements that are inherent to the spherical coordinate system of ground-based weather radars. Because of this, even with the direction-splitting design of the A-B tilter postanalysis gradients do not equal the analysis of gradients. Ringing in the response function of a one-dimensional Barnes filter is illustrated. The negative impact of data windows on the main lobe of the response function is found to decrease rapidly as the window is widened relative to the weight function. Unless an analysis point is near a data boundary, in which case both ringing and phase shifting will adversely affect the analysis, window effects are unlikely to be significant in applications of the A-B filter to radar data. The A-B tilter has potential drawbacks, the most significant of which is misinterpretations owing to the use of the A-B tilter without comprehension of its direction- and range-dependent response function. Despite its drawbacks, the A-B tilter has the potential to improve analyses owing to the aforementioned attributes and thus to aid research efforts in areas such as multiple-Doppler wind analyses, pseudo-dual-Doppler analyses, and retrieval studies. C1 Univ Oklahoma, Energy Ctr, Sch Meteorol, Norman, OK 73019 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Ctr Anal & Predict Storms, Sch Meteorol, Norman, OK 73019 USA. RP Askelson, MA (reprint author), Univ Oklahoma, Energy Ctr, Sch Meteorol, 100 E Boyd St, Norman, OK 73019 USA. NR 47 TC 20 Z9 23 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 2000 VL 128 IS 9 BP 3050 EP 3082 DI 10.1175/1520-0493(2000)128<3050:AAOTBF>2.0.CO;2 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356UK UT WOS:000089461100002 ER PT J AU Smith, SB LaDue, JG MacGorman, DR AF Smith, SB LaDue, JG MacGorman, DR TI The relationship between cloud-to-ground lightning polarity and surface equivalent potential temperature during three tornadic outbreaks SO MONTHLY WEATHER REVIEW LA English DT Article ID CONTIGUOUS UNITED-STATES; ELECTRICAL STRUCTURE; RADAR OBSERVATIONS; GREAT-PLAINS; STORM; THUNDERSTORMS; SUPERCELL; OKLAHOMA; EVOLUTION AB The relationship between cloud-to-ground (CGI lightning polarity and surface equivalent potential temperature (theta(e)) is examined for the 26 April 1991, Andover-Wichita, Kansas; the 13 March 1990, Hesston, Kansas; and the 28 August 1990, Plainfield, Illinois, tornadic storm events. The majority of thunderstorms whose CG lightning activity was dominated by negative flashes (labeled negative storms) formed in regions of weak theta(e) gradient and downstream of a theta(e) maximum. The majority of thunderstorms whose initial CG lightning activity was dominated by positive hashes formed in regions of strong theta(e) gradient, upstream of a theta(e) maximum. Some of these storms moved adjacent to the theta(e) maximum and were dominated by positive CG lightning throughout their lifetimes (labeled "positive storms"). The ether initially positive storms moved through the theta(e) maximum where their updrafts appeared to undergo intensification. The storms' dominant CG polarity switched from positive to negative after they crossed the theta(e) maximum (labeled reversal storms). Summary statistics based on this storm classification show that all the reversal storms examined for these three events were severe and half of them produced tornadoes of F3-F5 intensity. By comparison, only 58% of the negative storms produced severe weather and only 10% produced tornadoes of F3-F5 intensity. It is suggested that the CG lightning reversal process may be initiated by rapid updraft intensification brought about by an increase in the buoyancy of low-level inflow air as initially positive storms pass through mesoscale regions of high theta(e). As these storms move out of a theta(e) maximum, massive precipitation fallout may occur when their updrafts weaken and can no longer support the mass of liquid water and ice aloft. The fallout may in turn cause a major redistribution of the electrical charge within the storm resulting in polarity reversal and/or downdraft-induced tornadogenesis. C1 NOAA, NWS, Off Syst Dev, Tech Dev Lab, Silver Spring, MD 20910 USA. NOAA, Natl Weather Serv, Operat Training Branch, Operat Support Facil, Norman, OK USA. NOAA, Off Ocean & Atmospher Res, Environm Res Labs, Natl Severe Storms Lab, Norman, OK USA. RP Smith, SB (reprint author), NOAA, NWS, Off Syst Dev, Tech Dev Lab, WOSD24,1325 East West Highway,SSMC2, Silver Spring, MD 20910 USA. NR 31 TC 26 Z9 28 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 2000 VL 128 IS 9 BP 3320 EP 3328 DI 10.1175/1520-0493(2000)128<3320:TRBCTG>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356UK UT WOS:000089461100017 ER PT J AU Knaff, JA Weaver, JF AF Knaff, JA Weaver, JF TI A mesoscale low-level thunderstorm outflow boundary associated with Hurricane Luis SO MONTHLY WEATHER REVIEW LA English DT Article ID LAYER RECOVERY; BEHAVIOR; TORNADO; TOGA AB A large low-level thunderstorm outflow boundary was observed as it exited from beneath the cirrus canopy of Hurricane Luis following a period of intense convection in the storm's eyewall. A description of the feature and a short summary of its behavior are presented. C1 Colorado State Univ, NOAA, CIRA, Ft Collins, CO 80523 USA. NOAA, NESDIS, RAMM Team, Ft Collins, CO USA. RP Knaff, JA (reprint author), Colorado State Univ, NOAA, CIRA, Ft Collins, CO 80523 USA. RI Knaff, John /F-5599-2010 OI Knaff, John /0000-0003-0427-1409 NR 21 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 2000 VL 128 IS 9 BP 3352 EP 3355 DI 10.1175/1520-0493(2000)128<3352:AMLLTO>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356UK UT WOS:000089461100021 ER PT J AU Ding, J Hunt, FY AF Ding, J Hunt, FY TI Error estimates for quasi-compact Markov operators SO NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS LA English DT Article DE Markov operators; quasi-compactness ID FROBENIUS-PERRON OPERATORS; INVARIANT-MEASURES; FINITE APPROXIMATION; TRANSFORMATIONS C1 Univ So Mississippi, Dept Math, Hattiesburg, MS 39406 USA. Natl Inst Stand & Technol, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. RP Ding, J (reprint author), Univ So Mississippi, Dept Math, Hattiesburg, MS 39406 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0362-546X J9 NONLINEAR ANAL-THEOR JI Nonlinear Anal.-Theory Methods Appl. PD SEP PY 2000 VL 42 IS 1 BP 85 EP 95 DI 10.1016/S0362-546X(98)00335-6 PG 11 WC Mathematics, Applied; Mathematics SC Mathematics GA 334FJ UT WOS:000088175600007 ER PT J AU Wulfmeyer, V Randall, M Brewer, A Hardesty, RM AF Wulfmeyer, V Randall, M Brewer, A Hardesty, RM TI 2-mu m Doppler lidar transmitter with high frequency stability and low chirp SO OPTICS LETTERS LA English DT Article ID SINGLE-FREQUENCY; MODE-OPERATION; RING LASER; INJECTION; STABILIZATION AB A coherent Doppler lidar system was frequency stabilized in a master-slave configuration by a phase-modulation technique. The short-term frequency stability, similar to 0.2 MHz rms, was maintained in a vibrational environment on a ship during a field campaign in the tropical Pacific Ocean. The long-term frequency stability was <2.6 kHz/h. Thus, in many applications, shot-to-shot frequency correction can be disregarded, which will result in increased speed and simplicity of the data-acquisition system. A frequency chirp could not be detected. These properties permit Doppler wind measurements with high efficiency and duty cycles to be made, even on airborne and spaceborne platforms. (C) 2000 Optical Society of America OCIS codes: 280.3640, 140.3570. C1 Natl Ctr Atmospher Res, Atmospher Technol Div, Remote Sensing Facil, Boulder, CO 80307 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Wulfmeyer, V (reprint author), Natl Ctr Atmospher Res, Atmospher Technol Div, Remote Sensing Facil, POB 3000, Boulder, CO 80307 USA. RI Hardesty, Robert/H-9844-2013; Brewer, Wm Alan/I-3920-2013 NR 8 TC 70 Z9 70 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 1 PY 2000 VL 25 IS 17 BP 1228 EP 1230 DI 10.1364/OL.25.001228 PG 3 WC Optics SC Optics GA 349KV UT WOS:000089045000002 PM 18066175 ER PT J AU Gensemer, SD Gould, PL Leo, PJ Tiesinga, E Williams, CJ AF Gensemer, SD Gould, PL Leo, PJ Tiesinga, E Williams, CJ TI Ultracold Rb-87 ground-state hyperfine-changing collisions in the presence and absence of laser light SO PHYSICAL REVIEW A LA English DT Article ID TRAP-LOSS COLLISIONS; PHOTOASSOCIATIVE SPECTROSCOPY; MAGNETOOPTICAL TRAP; SODIUM ATOMS; COLD ATOMS; SCATTERING; MOLECULES; TIME AB We have measured the rate of hyperfine-changing collisions between ground-state Rb-87 atoms in a magnetooptical trap. Using a population switching technique, we directly measure the rate of these collisions in both the presence and absence of near-resonant trap laser light. We see a dramatic enhancement of the collision rate by the light and observe that, in the absence of the light, the rate increases with increasing temperature. There is consistency between this latter measured rate at temperatures below similar to 100 mu K and theoretical calculations constrained by other recent experiments. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Gensemer, SD (reprint author), Univ Connecticut, Dept Phys, U-46, Storrs, CT 06269 USA. RI Williams, Carl/B-5877-2009; Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 27 TC 0 Z9 0 U1 2 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 SEP PY 2000 VL 62 IS 3 BP art. no. EP 030702 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400004 ER PT J AU Djuric, N Neau, A Rosen, S Zong, W Dunn, GH AF Djuric, N Neau, A Rosen, S Zong, W Dunn, GH TI Light-ionic fragment production in dissociative electron-molecular-ion collisions: Detection of D+ and D-2(+) from NDn+ (n=2-4) and ODn+ (n=2,3) SO PHYSICAL REVIEW A LA English DT Article ID EXCITATION; RECOMBINATION AB Absolute cross sections are reported for the electron impact dissociative excitation of the deuterated ions NDn+ (n=2-4) and ODn+ (n=2,3) from threshold up to 70 eV using a crossed beams technique. The method focuses on measuring light dissociation-product ions from a heavy target. For all studied targets, D+ formation is the dominant channel, with absolute cross section values in the range of (1.3-2) x 10(-16) cm(2), once the initial rise from the threshold is past, continuing to 70 eV. The present measurements for dissociation of OD2+ and OD3+ yielding D+ are compared with recent results obtained in the storage ring experiments, these cross sections are found to be ina reasonable agreement within the quoted uncertainties over the part of the energy range where they are expected to be the-same. The cross sections for obtaining D-2(+) are about an order of magnitude smaller than the cross sections for D+ formation from the same targets. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. RP Djuric, N (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 21 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2000 VL 62 IS 3 AR 032702 DI 10.1103/PhysRevA.62.032702 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400041 ER PT J AU Kmety, CR Huang, QZ Lynn, JW Erwin, RW Manson, JL McCall, S Crow, JE Stevenson, KL Miller, JS Epstein, AJ AF Kmety, CR Huang, QZ Lynn, JW Erwin, RW Manson, JL McCall, S Crow, JE Stevenson, KL Miller, JS Epstein, AJ TI Noncollinear antiferromagnetic structure of the molecule-based magnet Mn[N(CN)(2)](2) SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL COMPLEXES; POWDER DIFFRACTION; PHENOMENOLOGICAL MODEL; INTERCALATION COMPOUND; NEUTRON-SCATTERING; PHASE-TRANSITIONS; DICYANAMIDE ANION; WEAK FERROMAGNETS; HEAT; M-II(2) AB The crystallographic and magnetic properties of the Mn[N(CN)(2)](2) compound have been investigated by de magnetization. ac susceptibility, specific heat, and zero-field neutron diffraction on polycrystalline samples. The magnetic structure consists of two sublattices which are antiferromagnetically coupled and spontaneously canted. The spin orientation is mainly along the a axis with a small uncompensated moment along the b axis. The ground state is a crystal-field sextet with large magnetic anisotropy. The crystal structure consists of discrete octahedra which are axially elongated and successively tilted in the ab plane. Comparisons of the magnetic structures for the isostructural M[N(CN)(2)](2) (M = Mn, Fe, Co, Ni) series suggest that the spin direction is stabilized by crystal fields and the spin canting is induced by the successive tilting of the octahedra. Wr propose that the superexchange interaction is the mechanism responsible for the magnetic ordering in these compounds and we find that a crossover from noncollinear antiferromagnetism to collinear ferromagnetism occurs for a superexchange angle of alpha(c) = 142.0(5)degrees. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Indiana Univ Purdue Univ, Dept Chem, Ft Wayne, IN 46805 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Kmety, CR (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. RI McCall, Scott/G-1733-2014 OI McCall, Scott/0000-0002-7979-4944 NR 61 TC 89 Z9 90 U1 1 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 5576 EP 5588 DI 10.1103/PhysRevB.62.5576 PG 13 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900059 ER PT J AU Fawcett, LD Kim, ES Greenblatt, M Croft, M Bendersky, LA AF Fawcett, LD Kim, ES Greenblatt, M Croft, M Bendersky, LA TI Properties of the electron-doped layered manganates La2-2xCa1+2xMn2O7 (0.6 <= x <= 1.0) SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; COLOSSAL MAGNETORESISTANCE; MAGNETIC-PROPERTIES; MANGANESE OXIDES; PEROVSKITE; FERROMAGNETISM; LA1-XCAXMNO3; SYSTEM AB The La2-2xCa1+2xMn2O7 (0.6 less than or equal to x less than or equal to 1.0) series has been successfully synthesized using a citrate gel technique in order to study their structure and properties as a function of x in the Mn4+-rich region of the phase diagram. Rietveld refinement of powder x-ray diffraction data, combined with electron microscopy, shows that the phases are of high purity and adopt the n=2 Ruddlesden-Popper structure comprised of perovskite bilayers separated by rocksalt layers. The lattice parameter c reaches a minimum at x similar to 0.7 and the increase with x is attributed to elongation of the apical Mn-O bonds due to preferential A-site occupancy and/or splitting of the t(2g): levels of Mn4+. X-ray absorption spectroscopy measurements confirm that the Mn-valence variation in these series tracks formal valence expectations. In the region 0.6 less than or equal to x less than or equal to 0.8 the magnetic susceptibility manifests a peak or shoulder at similar to 280 K due to charge and orbital ordering, and antiferromagnetic order develops at lower temperatures (T(N)similar to 150-200 K) with quasi-two-dimensional antiferromagnetic fluctuation effects being evidenced above T-N. The magnetic properties change significantly at 0.825 less than or equal to x less than or equal to 1.0: at higher temperatures two-dimensional magnetic coupling is observed and at similar to 115 K the system spontaneously orders antiferromagnetically, but with a ferromagnetic moment. The transport results indicate insulating behavior at all compositions, but with an enhanced localization upon charge/orbital ordering in the x=0.7 material. C1 Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. RP Fawcett, LD (reprint author), Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. NR 30 TC 19 Z9 19 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 10 BP 6485 EP 6495 PG 11 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400055 ER PT J AU Shaffner, TJ AF Shaffner, TJ TI Semiconductor characterization and analytical technology SO PROCEEDINGS OF THE IEEE LA English DT Article DE analytical techniques; characterization review; Fourier transform infrared; Fourier transform photoluminescence; materials characterization; microspot analysis; radiochemical techniques; Rutherford backscattering spectrometry; scanning Auger microscopy; scanning electron microscopy; scanning probe microscopy; secondary ion mass spectrometry semiconductor; thin-film analysis; time-of-flight SIMS; total-reflection X-ray fluorescence; transmission electron microscopy; X-ray diffraction; X-ray fluorescence; X-ray topography ID ION MASS-SPECTROMETRY; CAPACITANCE MICROSCOPY MEASUREMENTS; HIGH-RESOLUTION; INTERLABORATORY DETERMINATION; OXYGEN PRECIPITATION; INTERSTITIAL OXYGEN; INFRARED-ABSORPTION; ELECTRON-MICROSCOPY; ACTIVATION ANALYSIS; MAGNETIC-RESONANCE AB The utility of semiconductor characterization techniques continues to be measured by industry requirements for smaller device geometry atomically smooth surfaces and interfaces, and increased material purity. Those techniques that specialize in the microspot and structural analysis of microcircuits are reviewed in this paper with examples of applications ro manufacturing and process development. Brief tutorials, case studies, and comparisons show how the strengths and weaknesses of each should be understood before selecting those methods most suitable for the problem at hand. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Shaffner, TJ (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM thomas.shaffner@nist.gov NR 99 TC 6 Z9 6 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD SEP PY 2000 VL 88 IS 9 BP 1416 EP 1437 DI 10.1109/5.883315 PG 22 WC Engineering, Electrical & Electronic SC Engineering GA 373XL UT WOS:000165315300004 ER PT J AU Sharov, VA Xiao, QF Ponomarev, IY Mildner, DFR Chen-Mayer, HH AF Sharov, VA Xiao, QF Ponomarev, IY Mildner, DFR Chen-Mayer, HH TI Cold neutron microprobe for materials analysis using tapered capillary optics SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID GAMMA-ACTIVATION-ANALYSIS; LENS AB A prototype monolithic capillary lens for focusing neutrons produced by thermally drawing straight multicapillary bundles has been characterized with cold neutrons, and gives an intensity gain of a factor of 25 at a focal distance of 8 mm, over the focal spot area of width 87 mu m. This is over an order of magnitude smaller in area than for the multifiber capillary lens. The spatial resolution available with the lens has been tested with prompt gamma measurements on slivers of dysprosium. Background problems that can affect the spatial resolution of measurements taken at the focal position of the lens are addressed. The boron glass of the tapered monolithic lens provides good shielding from unfocused neutrons in the vicinity of the lens focus. (C) 2000 American Institute of Physics. [S0034-6748(00)05109-1]. C1 Xray Opt Syst Inc, Albany, NY 12203 USA. NIST, Gaithersburg, MD 20899 USA. RP Sharov, VA (reprint author), Inst Genom Res, 9712 Med Ctr Dr, Rockville, MD 20850 USA. NR 10 TC 2 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3247 EP 3253 DI 10.1063/1.1288262 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700001 ER PT J AU Snyder, ES Suehle, JS AF Snyder, ES Suehle, JS TI Fast breakdown detection in ultra-thin dielectrics SO SOLID STATE TECHNOLOGY LA English DT Article ID SOFT BREAKDOWN; GATE OXIDES; SILICON AB We propose a voltage ramp technique that detects ultra-thin oxide breakdown when other techniques (such as noise) fail. This technique provides a straightforward method of extending conventional ramp breakdown techniques to ultra-thin dielectrics. We show for the first time that the post-stress leakage current is independent of oxide area over seven orders of magnitude and for an oxide thickness range of 2.3-20nm. In addition, we show that the voltage ramp Weibull distribution statistics scale with area and are consistent with constant voltage stress tests on 2nm gate oxides. We model the post-breakdown I-V characteristics and show space-charge limited behavior. This observation is used to explain why a modified voltage ramp technique is needed for ultra-thin oxides and defect-detecting large area structures. Finally we demonstrate that new noise techniques may be necessary to detect breakdown during constant voltage stress in ultra-thin gate oxides. C1 Sandia Technol Inc, Albuquerque, NM 87109 USA. NIST, Semicond Elect Div, Gaithersburg, MD 20899 USA. RP Snyder, ES (reprint author), Sandia Technol Inc, 6003 Osuna Rd NE, Albuquerque, NM 87109 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 USA SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD SEP PY 2000 SU S BP S4 EP S8 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 355GH UT WOS:000089377600002 ER PT J AU Lamaze, GP Chen-Mayer, HH Gerouki, A Goldner, RB AF Lamaze, GP Chen-Mayer, HH Gerouki, A Goldner, RB TI Analysis of lithium transport in electrochromic multilayer films by neutron depth profiling SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE electrochromic films; depth profiling; lithium; multilayers; neutrons; optical transmission AB Thin film 'rocking-chair' type cells hold great promise for 'smart window' and rechargeable battery applications. Smart windows alter the transmissivity between any two states over the solar spectrum by electrical current modulation, which causes lithium ions to migrate back and forth between the two electrochromic layers, This paper reports measurement of the lithium distribution in each layer and transport between layers by the method of neutron depth profiling (NDP). Samples are irradiated by a beam of 'cold' neutrons that induce the Li-6(n,alpha)H-3 reaction. Both the intensity and energy of the reaction products-the alpha-particles and tritons-are measured by surface barrier detectors. Comparing the emission intensity with that of a known standard leads to quantitative determination of the lithium concentrations. The energy loss of the emitted charged particles due to interactions with the matrix provides a direct measurement of the depth of the originating lithium nucleus. The non-destructive nature of the NDP technique allows in situ measurements of the lithium concentration under different voltage bias conditions, The data acquisition method and data analysis techniques are explained. Results of the concentration measurements as a function of bias are presented. possible applications into other lithium multilayers are also discussed. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Tufts Univ, Electro Opt Technol Ctr, Medford, MA 02115 USA. RP Lamaze, GP (reprint author), NIST, Chem Sci & Technol Lab, 100 Bur Dr Stop 8395, Gaithersburg, MD 20899 USA. NR 12 TC 1 Z9 1 U1 1 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD SEP PY 2000 VL 29 IS 9 BP 638 EP 642 PG 5 WC Chemistry, Physical SC Chemistry GA 355HU UT WOS:000089380900009 ER PT J AU Hendry, AP Dittman, AH Hardy, RW AF Hendry, AP Dittman, AH Hardy, RW TI Proximate composition, reproductive development, and a test for trade-offs in captive sockeye salmon SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID FEMALE ATLANTIC SALMON; ONCORHYNCHUS-NERKA; LIFE-HISTORY; SPAWNING MIGRATION; LIPID DISTRIBUTION; ARCTIC CHARR; BODY-SIZE; SALAR; ALLOCATION; SURVIVAL AB Energy limitations during reproduction should lead to the evolution of adaptive patterns of energy use and should cause trade-offs in the expression of different traits. We addressed these issues by measuring secondary sexual development, gonad investment, and proximate composition for sockeye salmon Oncorhynchus nerka maturing in captivity. Each of the last 3 months before maturity was characterized by a different pattern of reproductive development and energy use. From June to July, gonad mass increased (1.1% to 5.2% of male body mass; from 1.3% to 2.7% of female body mass), muscle fat decreased (15.1% to 8.6% sex-specific values averaged), and viscera fat decreased (23.9% to 16.7%). From July to August, male gonad mass did not change appreciably, but female gonad mass nearly doubled (to 5.5% of body mass). Muscle fat and viscera fat continued to decrease (to 6.0% and 8.8%, respectively), but muscle protein remained relatively constant. From August to maturity (September-October), female gonad mass more than tripled (to 18.6% of body mass) and secondary sexual characters increased in linear dimension by as much as 20.0% (male snout length). Viscera fat continued to decline (to 3.3%), but muscle fat did not decrease appreciably. The conservation of muscle protein until after fat was depleted may postpone reductions in performance that would accompany muscle degeneration. Mass-specific energy decreased between June and maturity in muscle (9.5-5.6 kJ (.) g(-1)) and viscera (11.2-4.9 kJ (.) g(-1)). We found no evidence for trade-offs in allocation between stored somatic energy, the size of secondary sexual characters, and gonad investment. An important area requiring further research is the effect of variation in energy stores prior to maturity on reproductive development at maturity. This prebreeding energy variation may obscure phenotypic trade-offs. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Hendry, AP (reprint author), Univ Massachusetts, Organism & Evolut Biol Program, 319 Morrill Sci Ctr, Amherst, MA 01003 USA. RI Hendry, Andrew/C-5765-2008 OI Hendry, Andrew/0000-0002-4807-6667 NR 45 TC 19 Z9 19 U1 2 U2 11 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 2000 VL 129 IS 5 BP 1082 EP 1095 DI 10.1577/1548-8659(2000)129<1082:PCRDAA>2.0.CO;2 PG 14 WC Fisheries SC Fisheries GA 375VQ UT WOS:000165422300002 ER PT J AU Furey, PR Gupta, VK AF Furey, PR Gupta, VK TI Space-time variability of low streamflows in river networks SO WATER RESOURCES RESEARCH LA English DT Article ID RECESSION AB A low-flow equation is derived from Darcy's law and a mass balance equation for base flow from a hillside by assuming that groundwater recharge is constant over short time periods. This low-flow equation reduces to many of the existing mechanistic low-flow equations, but in its general form looks like a linear regression model and captures spatial variability in base flow among hillsides in a basin. As a result, it unifies the mechanics and statistics of low flows in river networks. This equation is tested against low-flow data from the Flint River basin in Georgia and the Gasconade River basin in Missouri, both of which are approximately 7000 km(2) in size. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Dept Geol Sci, Boulder, CO 80309 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Dept Civil & Environm Engn, Boulder, CO 80309 USA. RP Furey, PR (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Dept Geol Sci, Boulder, CO 80309 USA. NR 45 TC 21 Z9 21 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD SEP PY 2000 VL 36 IS 9 BP 2679 EP 2690 DI 10.1029/2000WR900136 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 351XE UT WOS:000089184100022 ER PT J AU Sieber, JR AF Sieber, JR TI X-rays in research and development at the National Institute of Standards and Technology SO X-RAY SPECTROMETRY LA English DT Article ID CURVED CRYSTAL SPECTROMETER; MICROFLUORESCENCE ANALYSIS; GEOLOGICAL SAMPLES; FLUORESCENCE SPECTROMETRY; QUANTITATIVE-ANALYSIS; INDIVIDUAL PARTICLES; HIGH-RESOLUTION; MICROANALYSIS; MICROCALORIMETER; EMISSION AB Researchers at the National Institute of Standards and Technology make extensive use of x-rays for everything from elemental analysis and microanalysis to metrology and lithography to basic research in physics. Instrumentation includes commercial x-ray spectrometers to synchrotron beam lines to the custom-designed electron beam ion trap, Without including diffraction, one will find x-rays as a research topic or as an analytical tool in five of the seven technical laboratories: Electronics and Electrical Engineering, Chemical Science and Technology, Physics, Materials Science and Engineering, and Building and Fire Research. This paper provides a brief tour of these x-ray facilities and current research, in both Gaithersburg, Maryland and Boulder, Colorado, that fall within the scope of X-Ray Spechometry (and then some). Published in 2000 by John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sieber, JR (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8391, Gaithersburg, MD 20899 USA. NR 72 TC 3 Z9 3 U1 1 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0049-8246 J9 X-RAY SPECTROM JI X-Ray Spectrom. PD SEP-OCT PY 2000 VL 29 IS 5 BP 327 EP 338 PG 12 WC Spectroscopy SC Spectroscopy GA 363PP UT WOS:000089844000002 ER PT J AU Dailey, MD Gulland, FMD Lowenstine, LJ Silvagni, P Howard, D AF Dailey, MD Gulland, FMD Lowenstine, LJ Silvagni, P Howard, D TI Prey, parasites and pathology associated with the mortality of a juvenile gray whale (Eschrichtius robustus) stranded along the northern California coast SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE cetacean stranding; pacific gray whale; Eschrichtius robustus; hematology; pathology; parasites; prey species AB An eastern Pacific gray whale (Eschrichtius robustus) stranded off Pelican Point, Tomales Bay, California, USA, was examined for physiological parameters, prey, parasites and associated pathology. The whale was emaciated, and hematological examination revealed an elevation in hematocrit, serum sodium, potassium, electrolyte values and hypoglycemia. Parasites recovered included 5 species, 1 ectoparasite (Cyamus scammoni), and 4 helminths (Anisakis simplex, Ogmogaster antarcticus, Ogmogaster pentalineatus, Bolbosoma balanae) with the latter causing multifocal transmural abscesses, Histological examination indicated severe acute lung congestion, minimal, multifocal, lymphocytic, interstitial myocarditis, and mild hepatocellular and Kupffer cell hemosiderosis. The prey taxa present in the stomach indicated the whale was feeding on hard bottom communities prior to death. C1 Marine Mammal Ctr, Sausalito, CA 94965 USA. Univ Calif Davis, Vet Med Teaching Hosp, Davis, CA 95616 USA. Gulf Farallones Natl Marine Sanctuary, San Francisco, CA 94123 USA. RP Dailey, MD (reprint author), Marine Mammal Ctr, 1065 Ft Cronkhite, Sausalito, CA 94965 USA. NR 30 TC 8 Z9 8 U1 1 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD AUG 31 PY 2000 VL 42 IS 2 BP 111 EP 117 DI 10.3354/dao042111 PG 7 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 364KQ UT WOS:000089891900004 PM 11023250 ER PT J AU Marquez, M Mari, F Gonzalez, CA AF Marquez, M Mari, F Gonzalez, CA TI Ab initio study of the reactions between a series of substituted singlet nitrenium ions and water (vol 103A, pg 6191, 1999) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Correction C1 Florida Atlantic Univ, Dept Chem & Biochem, Boca Raton, FL 33431 USA. Florida Atlantic Univ, Ctr Mol Biol & Biotechnol, Boca Raton, FL 33431 USA. Yale Univ, Dept Chem, New Haven, CT 06520 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Mari, F (reprint author), Florida Atlantic Univ, Dept Chem & Biochem, 777 Glades Rd, Boca Raton, FL 33431 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 31 PY 2000 VL 104 IS 34 BP 8154 EP 8154 DI 10.1021/jp002138+ PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 349VX UT WOS:000089067200030 ER PT J AU Phelps, AV Greene, CH Burke, JP AF Phelps, AV Greene, CH Burke, JP TI Collision cross sections for argon atoms with argon atoms for energies from 0.01 eV to 10 keV SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ELASTIC-SCATTERING MEASUREMENTS; MONTE-CARLO SIMULATION; HIGH-ELECTRIC-FIELD; GLOW-DISCHARGE; INTERMOLECULAR POTENTIALS; THERMAL-CONDUCTIVITY; SLOW COLLISIONS; CHARGE-TRANSFER; FAST NEUTRALS; GAS-DENSITY AB Differential and angular integrated cross sections for elastic collisions of Ar atoms with Ar atoms are calculated from representative potential energy curves for collision energies from 0.01 eV to 10 keV. The scattering phase shifts are calculated using the WKB approximation. The cross sections are compared with data obtained from beam scattering experiments and transport coefficient measurements. On the basis of assessments of experimental reliability and of theoretical potentials, we make a selection from the available short-range interatomic potentials. Consideration of experimental elastic and inelastic cross section data leads to the suggestion that our theoretical results should be interpreted as the sum of the elastic and inelastic differential cross sections. The theoretical differential, total and viscosity cross sections are fitted with empirical functions covering the energy range from 1 eV to 10 keV to facilitate their use in models of discharge plasmas, etc. Procedures for use of these cross sections are summarized briefly. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Phelps, AV (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 69 TC 38 Z9 39 U1 1 U2 18 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD AUG 28 PY 2000 VL 33 IS 16 BP 2965 EP 2981 DI 10.1088/0953-4075/33/16/303 PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 354YW UT WOS:000089359700009 ER PT J AU Cornish, SL Claussen, NR Roberts, JL Cornell, EA Wieman, CE AF Cornish, SL Claussen, NR Roberts, JL Cornell, EA Wieman, CE TI Stable Rb-85 Bose-Einstein condensates with widely tunable interactions SO PHYSICAL REVIEW LETTERS LA English DT Article ID FESHBACH RESONANCES; ATTRACTIVE INTERACTIONS; SCATTERING; COLLISIONS; COLLAPSE; RUBIDIUM; CESIUM; GASES; ATOMS AB Bose-Einstein condensation has been achieved in a magnetically trapped sample of Rb-85 atoms. Long lived condensates of up to 10(4) atoms have been produced by using a magnetic-field-induced Feshbach resonance to reverse the sign of the scattering length. This system provides new opportunities for the study of condensate physics. The variation of the scattering length near the resonance has been used to magnetically tune the condensate self-interaction energy over a wide range, extending from strong repulsive to large attractive interactions. When the interactions were switched from repulsive to attractive, the condensate shrank to below our resolution limit; and after similar to 5 ms emitted a burst of high-energy atoms. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Cornell, EA (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Cornish, Simon/K-4966-2012 OI Cornish, Simon/0000-0003-1407-4126 NR 26 TC 708 Z9 716 U1 11 U2 30 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 28 PY 2000 VL 85 IS 9 BP 1795 EP 1798 DI 10.1103/PhysRevLett.85.1795 PG 4 WC Physics, Multidisciplinary SC Physics GA 348BW UT WOS:000088965300004 ER PT J AU Stoudt, MR Cammarata, RC Ricker, RE AF Stoudt, MR Cammarata, RC Ricker, RE TI Suppression of fatigue cracking with nanometer-scale multilayered coatings SO SCRIPTA MATERIALIA LA English DT Article DE fatigue; multilayers; plating; surfaces; crack initiation ID DAMAGE ACCUMULATION; THIN-FILMS; SURFACE; DEFORMATION; INITIATION; METALS C1 Natl Inst Stand & Technol, Div Met, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. RP Stoudt, MR (reprint author), Natl Inst Stand & Technol, Div Met, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. RI Cammarata, Robert /A-3307-2010; Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 25 TC 31 Z9 32 U1 3 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 28 PY 2000 VL 43 IS 6 BP 491 EP 496 DI 10.1016/S1359-6462(00)00449-8 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 355EJ UT WOS:000089373000003 ER PT J AU Olsen, MA Gallus, WA Stanford, JL Brown, JM AF Olsen, MA Gallus, WA Stanford, JL Brown, JM TI Fine-scale comparison of TOMS total ozone data with model analysis of an intense Midwestern cyclone SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TOTAL COLUMN OZONE; POTENTIAL VORTICITY; MASS-EXCHANGE; TROPOSPHERE; EVOLUTION; FIELDS; WAVES AB High-resolution (similar to 40 km) along-track total column ozone data from the Total Ozone Mapping Spectrometer (TOMS) instrument are compared with a high-resolution mesoscale numerical model analysis of an intense cyclone in the Midwestern United States. Total ozone increased by similar to 100 DU (nearly 38%) as the TOMS instrument passed over the associated tropopause fold region. Complex structure is seen in the meteorological fields and compares well with the total ozone observations. Ozone data support the meteorological analysis showing that stratospheric descent was confined to levels above similar to 600 hPa; significant positive potential vorticity at lower levels is attributable to diabatic processes. Likewise, meteorological fields show that two pronounced ozone streamers extending north and northeastward into Canada at high levels are not bands of stratospheric air feeding into the cyclone; one is a channel of exhaust downstream from the system, and the other apparently previously connected the main cyclonic circulation to a southward intrusion of polar stratospheric air and advected eastward as the cut-off cyclone evolved. Good agreement between small-scale features in the model output and total ozone data underscores the latter's potential usefulness in diagnosing upper-tropospheric/lower-stratospheric dynamics and kinematics. C1 Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Geol & Atmospher Sci, Ames, IA 50011 USA. NOAA, R FSI, Environm Res Lab, Forecast Syst Lab, Boulder, CO 80303 USA. RP Olsen, MA (reprint author), Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. EM molsen@iastate.edu; wgallus@iastate.edu; stanford@iastate.edu; jmbrown@fsl.noaa.gov RI Brown, John/D-3361-2015 NR 33 TC 17 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2000 VL 105 IS D16 BP 20487 EP 20495 DI 10.1029/2000JD900205 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 350NH UT WOS:000089107600004 ER PT J AU Hamilton, K Fan, SM AF Hamilton, K Fan, SM TI Effects of the stratospheric quasi-biennial oscillation on long-lived greenhouse gases in the troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; ATMOSPHERIC METHANE; MIDDLE ATMOSPHERE; INTERANNUAL VARIABILITY; GROWTH-RATE; OZONE; SENSITIVITY; CH4 AB An analysis is presented of results of an extended integration with a global general circulation model that includes treatment of a long-lived tropospheric trace constituent as well as a momentum source that forces a realistic stratospheric quasibiennial oscillation (QBO) It is shown that the dynamical QBO may modulate stratosphere-troposphere exchange in such a manner as to produce a QBO in global-mean tropospheric tracer mixing ratio. For the growth rate of tropospheric methane this transport-induced QBO is expected to have a peak-to-peak amplitude of 1-2 ppbv yr(-1) which, while modest compared with the full range of observed variability in growth rate, is still significant. The observed methane growth rate time series during 1983-1999 is shown to be consistent with the predicted QBO effect,although the record is definitely dominated by other interannual variations. C1 Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08542 USA. RP Hamilton, K (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, NOAA, POB 308, Princeton, NJ 08542 USA. EM kph@gfdl.gov; fan@splash.princeton.edu NR 24 TC 8 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2000 VL 105 IS D16 BP 20581 EP 20587 DI 10.1029/2000JD900331 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 350NH UT WOS:000089107600011 ER PT J AU Thompson, RS Snyder, WH Weil, JC AF Thompson, RS Snyder, WH Weil, JC TI Laboratory simulation of the rise of buoyant thermals created by open detonation SO JOURNAL OF FLUID MECHANICS LA English DT Article AB Laboratory experiments were conducted in a water tank to investigate the rise through the atmosphere of thermals generated by the detonation of surplus military munitions. The fall of a dense volume of fluid through the water in the tank follows the same governing equations as the rise of a buoyant volume of gas in the atmosphere. By filling the tank with a layer of water and a layer of salt water, an elevated step change in density was obtained, simulating a temperature inversion or jump in the atmosphere. The growth of the linear dimensions of the thermal and its volume were determined and used in the development of a criterion for predicting when a thermal will fully penetrate the inversion. Replacing the second layer of fluid with water of gradually increasing salinity, an elevated constant density gradient was obtained. In these cases, the maximum penetration distance of the thermal was observed and the equilibrium position and vertical spread were determined experimentally. These observations and the empirical relationships determined from them should prove useful in the development and evaluation of air pollution dispersion models for predicting the atmospheric transport and diffusion of material released during such detonations. C1 US EPA, Natl Exposure Res Lab, Atmospher Modeling Div, Res Triangle Pk, NC 27711 USA. NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Thompson, RS (reprint author), US EPA, Natl Exposure Res Lab, Atmospher Modeling Div, Res Triangle Pk, NC 27711 USA. NR 14 TC 9 Z9 12 U1 1 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD AUG 25 PY 2000 VL 417 BP 127 EP 156 DI 10.1017/S0022112000001191 PG 30 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 355NT UT WOS:000089392300005 ER PT J AU Torres, CR Hanazaki, H Ochoa, J Castillo, J Van Woert, M AF Torres, CR Hanazaki, H Ochoa, J Castillo, J Van Woert, M TI Flow past a sphere moving vertically in a stratified diffusive fluid SO JOURNAL OF FLUID MECHANICS LA English DT Article AB Numerical studies are described of the flows generated by a sphere moving vertically in a uniformly stratified fluid. It is found that the axisymmetric standing vortex usually found in homogeneous fluids at moderate Reynolds numbers (25 less than or equal to Re less than or equal to 200) is completely collapsed by stable stratification, generating a strong vertical jet. This is consistent with our experimental visualizations. For Re = 200 the complete collapse of the vortex occurs at Froude number F similar or equal to 19, and the critical Froude number decreases slowly as Re increases. The Froude number and the Reynolds number are here defined by F = W/Na and Re = 2Wa/v, with W being the descent velocity of the sphere, N the Brunt-Vaisala frequency, a the radius of the sphere and v the kinematic viscosity coefficient. The inviscid processes, including the generation of the vertical jet, have been investigated by Eames & Hunt (1997) in the context of weak stratification without buoyancy effects. They showed the existence of a singularity of vorticity and density gradient on the rear axis of the flow and also the impossibility of realizing a steady state. When there is no density diffusion, all the isopycnal surfaces which existed initially in front of the sphere accumulate very near the front surface because of density conservation and the fluid in those thin layers generates a rear jet when returning to its original position. In the present study, however, the fluid has diffusivity and the buoyancy effects also exist. The density diffusion prevents the extreme piling up of the isopycnal surfaces and allows the existence of a steady solution, preventing the generation of a singularity or a jet. On the other hand, the buoyancy effect works to increase the vertical velocity to the rear of the sphere by converting the potential energy to vertical kinetic energy, leading to the formation of a strong jet. We found that the collapse of the vortex and the generation of the jet occurs at much weaker stratifications than those necessary for the generation of strong lee waves, showing that jet formation is independent of the internal waves. At low Froude numbers (F less than or equal to 2) the lee wave patterns showed good agreement with the linear wave theory and the previous experiments by Mowbray & Rarity (1967). At very low Froude numbers (F less than or equal to 1) the drag on a sphere increases rapidly, partly due to the lee wave drag but mainly due to the large velocity of the jet. The: jet causes a reduction of the pressure on the rear surface of the sphere, which leads to the increase of pressure drag. High velocity is induced also just outside the boundary layer of the sphere so that the frictional drag increases even more significantly than the pressure drag. C1 Univ Autonoma Baja California, Inst Invest Oceanol, Ensenada 22800, Baja California, Mexico. Tohoku Univ, Inst Fluid Sci, Aoba Ku, Sendai, Miyagi 9808577, Japan. Ctr Invest Cient & Educ Super Ensenada, Ensenada, Baja California, Mexico. San Diego State Univ, Dept Math, San Diego, CA 92812 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. Univ Tokyo, Dept Mech Engn, Bunkyo Ku, Tokyo 1138656, Japan. RP Torres, CR (reprint author), Univ Autonoma Baja California, Inst Invest Oceanol, AP 453, Ensenada 22800, Baja California, Mexico. OI /0000-0001-6121-3972 NR 27 TC 28 Z9 29 U1 2 U2 10 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD AUG 25 PY 2000 VL 417 BP 211 EP 236 DI 10.1017/S0022112000001002 PG 26 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 355NT UT WOS:000089392300008 ER PT J AU Manderson, JP Phelan, BA Stoner, AW Hilbert, J AF Manderson, JP Phelan, BA Stoner, AW Hilbert, J TI Predator-prey relations between age-1 + summer flounder (Paralichthys dentatus, Linnaeus) and age-0 winter flounder (Pseudopleuronectes americanus, Walbaum): predator diets, prey selection, and effects of sediments and macrophytes SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE flatfish predator; prey choice; prey size selection; burial; sea grass; sea lettuce ID WINTER FLOUNDER; HABITAT COMPLEXITY; PSEUDOPLEURONECTES-AMERICANUS; PLEURONECTES-PLATESSA; SEDIMENT PREFERENCE; 0-GROUP FLATFISHES; FIELD OBSERVATIONS; JUVENILE PLAICE; LARGEMOUTH BASS; SUMMER FLOUNDER AB Laboratory experiments and weekly trammel net surveys in the Navesink River, New Jersey (USA) were used to examine the predator-prey interaction between age-1 + summer flounder (Paralichthys dentatus) and age-0 winter flounder (Pseudopleuronectes americanus). Winter flounder (24-67 mm TL) were the dominant piscine prey of summer flounder (n = 95, 252-648 mm TL) collected in trammel nets. We observed a temporal shift in summer flounder diets from sand shrimp (Crangon septemspinosa) and winter flounder, dominant during June and early July, to blue crabs (Callinectes sapidus) and other fishes (primarily Atlantic silversides, Menidia menidia and Atlantic menhaden, Brevortia tyrannus) later in the summer. Variations in prey selection appeared to be related to changes in the spatial distribution of predators and spatiotemporal variation in prey availability. In laboratory experiments, summer flounder (271-345 mm total length, TL) preferred demersal winter flounder to a pelagic fish (Atlantic silversides) and a benthic invertebrate (sand shrimp) prey, and the vulnerability of winter flounder increased with increasing prey body size from 20 to 90 mm TL. Experiments testing habitat effects showed that mortality of winter flounder in three different size classes (20-29, 40-49, 60-69 mm TL) was not influenced by sediment grain sizes permitting differential burial of the prey. However, vegetation enhanced survival, with fish suffering lower mortality in eelgrass (Zostera marina, 15+/-0.04%) than in sea lettuce (Ulva lactuca, 38+/-0.04%) or bare sand (70+/-0.07%) when the macrophytes were planted to produce similar leaf surface areas (5000 cm(2) m(-2)). Prey vulnerability appeared to be related to the role of vision in the predator's attack strategy and prey activity levels. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Behav Ecol Branch, Highlands, NJ 07732 USA. RP Manderson, JP (reprint author), NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Behav Ecol Branch, Highlands, NJ 07732 USA. NR 76 TC 71 Z9 74 U1 0 U2 10 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 AUG 23 PY 2000 VL 251 IS 1 BP 17 EP 39 DI 10.1016/S0022-0981(00)00191-X PG 23 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 353PN UT WOS:000089284800002 ER PT J AU Luy, B Marino, JP AF Luy, B Marino, JP TI Direct evidence for Watson-Crick base pairs in a dynamic region of RNA structure SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LEAD-DEPENDENT RIBOZYME; HYDROGEN-BONDS; SCALAR COUPLINGS; ANTISENSE RNA; MESSENGER-RNA; BINDING; PROTEINS; IDENTIFICATION; SPECTROSCOPY; RECOGNITION C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. RP Marino, JP (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Luy, Burkhard/I-1918-2013 OI Luy, Burkhard/0000-0001-9580-6397 NR 26 TC 37 Z9 37 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 23 PY 2000 VL 122 IS 33 BP 8095 EP 8096 DI 10.1021/ja0000910 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 350CE UT WOS:000089082500037 ER PT J AU Harvey, AH Hodges, MP AF Harvey, AH Hodges, MP TI The effect of anisotropy on the second virial coefficient of H-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article C1 Natl Inst Stand & Technol, Div Phys & Chem Properties, Boulder, CO 80305 USA. Univ Nottingham, Sch Chem, Nottingham NG7 2RD, England. RP Harvey, AH (reprint author), Natl Inst Stand & Technol, Div Phys & Chem Properties, Boulder, CO 80305 USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 22 PY 2000 VL 113 IS 8 BP 3474 EP 3476 DI 10.1063/1.1287176 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800065 ER PT J AU Hayashi, M Grull, H Esker, AR Weber, M Sung, L Satija, SK Han, CC Hashimoto, T AF Hayashi, M Grull, H Esker, AR Weber, M Sung, L Satija, SK Han, CC Hashimoto, T TI Neutron reflectivity study of diblock formation during reactive blending processes SO MACROMOLECULES LA English DT Article ID POLYMER-POLYMER INTERFACES; DOMAIN-BOUNDARY STRUCTURE; X-RAY-SCATTERING; HOMOPOLYMER INTERFACES; LAMELLAR MICRODOMAINS; IMMISCIBLE POLYMERS; REACTION-KINETICS; BLOCK COPOLYMERS; MOLECULAR-WEIGHT; CHAIN-LENGTH AB In a series of neutron reflectivity experiments, we studied the fundamental process of diblock formation during reactive blending processes of an immiscible blend comprised of normal polysulfone (hPSU) containing 30% reactive end group-modified deuterated polysulfone (dPSU-R) and polyamide (PA). Diblock formation (dPSU-b-PA) and dPSU-R enrichment at the interface between the incompatible polymers were monitored in thin bilayer films using neutron reflectivity. These results are compared to experimental results obtained with bilayer films of pure nonreactive deuterated PSU (dPSU) and PA and pure reactive dPSU-R and PA, respectively. The interfacial width in the pure reactive system is slightly larger than that in the pure nonreactive system, indicating the formation of a diblock copolymer at the interface of the reactive system. The results for the diluted system (30% dPSU-R + 70% hPSU) show an enrichment of the deuterated species at the interface. The amount of dPSU-R at the interface rises from 30 vol % initially, up to an equilibrium value of 47 vol % after annealing at 210 degrees C within about 30 min. This is interpreted as the formation of diblock copolymer out of the reactive components, dPSU-R and PA, as an interfacial reaction. Annealing at T = 210 degrees C for substantially longer times reveals no further evolution of the interfacial profile, indicating that the diblock, once formed, stays localized at the interface. The formation of a diblock monolayer with complete coverage of the interfacial area is not observed. This is probably due to steric hindrance and strong segregation of the diblock between dPSU-R and PA. The block copolymer layer once formed at the interface suppresses the approach of additional dPSU-R homopolymer toward the interface due to the conformational entropy costs to the homopolymer and block copolymer already at the interface. For these reasons, it is possible to diminish but not eliminate the interfacial tension (gamma > 0) between the PSU and PA, as it is not possible to build up a large enough normalized surface excess, z*/R-g < 1, of dPSU-b-PA. C1 Kyoto Univ, Grad Sch Engn, Dept Polymer Chem, Kyoto 6068501, Japan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. BASF AG, Engn Plast, Polymer Res Lab, D-67056 Ludwigshafen, Germany. RP Hashimoto, T (reprint author), Kyoto Univ, Grad Sch Engn, Dept Polymer Chem, Kyoto 6068501, Japan. NR 52 TC 8 Z9 8 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 22 PY 2000 VL 33 IS 17 BP 6485 EP 6494 DI 10.1021/ma000109r PG 10 WC Polymer Science SC Polymer Science GA 348AK UT WOS:000088961400040 ER PT J AU Choi, S Briber, RM Bauer, BJ Liu, DW Gauthier, M AF Choi, S Briber, RM Bauer, BJ Liu, DW Gauthier, M TI Small-angle neutron scattering of blends of arborescent polystyrenes SO MACROMOLECULES LA English DT Article ID MOLECULAR-WEIGHT DEPENDENCE; LINEAR POLYMER DIMENSION; X-RAY-SCATTERING; COLLAPSED REGIME; CO-POLYMER; DENDRITIC MACROMOLECULES; POLYVINYL METHYL-ETHER); SPHERICAL MICRODOMAINS; STARBURST DENDRIMERS; DILUTE CONCENTRATION C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. Univ Waterloo, Dept Chem, Polymer Res Inst, Waterloo, ON N2L 3G1, Canada. RP Briber, RM (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 64 TC 13 Z9 13 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 22 PY 2000 VL 33 IS 17 BP 6495 EP 6501 DI 10.1021/ma000160v PG 7 WC Polymer Science SC Polymer Science GA 348AK UT WOS:000088961400041 ER PT J AU Goyette, AN Wang, YC Olthoff, JK AF Goyette, AN Wang, YC Olthoff, JK TI Inductively coupled plasmas in low global-warming-potential gases SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID ELECTRON-ATTACHMENT; ENERGY-DISTRIBUTIONS; ION-BOMBARDMENT; CROSS-SECTIONS; REFERENCE CELL; CF3I; HALOCARBONS; IONIZATION; DISCHARGES; ABSORPTION AB Many high-density discharges used in microelectronics fabrication use fluorocarbon gases with coincidentally high global-warming potentials (GWPs). We have determined the identities, fluxes, and energy distributions of ions produced in high-density discharges generated in two low GWP gases, CF3I and CF3CH2F (HFC-134a), which have attracted interest for plasma processing applications. Measurements were made using a combined ion energy analyser-mass spectrometer that samples ions through an orifice in the lower electrode of an inductively coupled Gaseous Electronics Conference (GEC) rf reference cell. The effects of plasma operating conditions and Ar dilution on ion fluxes and energies were examined. Nearly complete dissociation of CF3I occurs in CF3I discharges and I+ comprises almost all of the ion yield. Mean ion energies range from 5 eV to 10 eV for the operating conditions investigated. Discharges generated in mixtures of CF3I with Ar have ion fluxes and energies resembling those in pure CF3I discharges. Pure HFC-134a discharges produce several ions of significant intensity, with HF+ and Si+ bring the most abundant. Mean ion energies range from 20 eV to 35 eV, and decrease as HFC-134a is diluted with Ar. Higher discharge powers result in greater dissociation in HFC-134a discharges, shifting the ion composition towards higher fluxes of lighter ions. C1 Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. RP Goyette, AN (reprint author), Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. NR 27 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD AUG 21 PY 2000 VL 33 IS 16 BP 2004 EP 2009 DI 10.1088/0022-3727/33/16/312 PG 6 WC Physics, Applied SC Physics GA 349XB UT WOS:000089069900012 ER PT J AU Ichikawa, N Uchida, S Tranquada, JM Niemoller, T Gehring, PM Lee, SH Schneider, JR AF Ichikawa, N Uchida, S Tranquada, JM Niemoller, T Gehring, PM Lee, SH Schneider, JR TI Local magnetic order vs superconductivity in a layered cuprate SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; EARTH-DOPED LA2-XSRXCUO4; CHARGE-STRIPE ORDER; FERMI-LIQUID; PHASE; LA1.48ND0.4SR0.12CUO4; FLUCTUATIONS; SUBSTITUTION; SPINS; HOLES AB We report on the phase diagram for charge-stripe order in La1.6-xNd0.4SrxCuO4, determined by neutron and x-ray scattering studies and resistivity measurements. From an analysis of the in-plane resistivity motivated by recent nuclear-quadrupole-resonance studies, we conclude that the transition temperature for local charge ordering decreases monotonically with x, and hence that local antiferromagnetic order is uniquely correlated with the anomalous depression of superconductivity at x approximate to 1/8. This result is consistent with theories in which superconductivity depends on the existence of charge-stripe correlations. C1 Univ Tokyo, Sch Engn, Dept Superconduct, Bunkyo Ku, Tokyo 1138656, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. DESY, Hamburger Synchrotronstrahlungslabor, HASYLAB, D-22603 Hamburg, Germany. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Ichikawa, N (reprint author), Kyoto Univ, Inst Chem Res, Uji 6110011, Japan. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Gehring, Peter/0000-0002-9236-2046 NR 33 TC 189 Z9 190 U1 2 U2 17 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 21 PY 2000 VL 85 IS 8 BP 1738 EP 1741 DI 10.1103/PhysRevLett.85.1738 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100039 ER PT J AU Allison, TC Poster, D Huie, RE Bamford, HA Baker, JE AF Allison, TC Poster, D Huie, RE Bamford, HA Baker, JE TI Computational and experimental determination of Henry's law constants of polynuclear aromatic hydrocarbons and polychlorinated biphenyls. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD USA. Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, College Pk, MD 20742 USA. RI Baker, Joel/A-9685-2011 OI Baker, Joel/0000-0002-9980-7781 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 305-PHYS BP U200 EP U201 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301123 ER PT J AU Allison, TC Gonzalez, CA AF Allison, TC Gonzalez, CA TI Development of a flexible and efficient software platform for geometry optimization in computational chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Exptl Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 292-PHYS BP U198 EP U199 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301110 ER PT J AU Anderson, DL Mackey, EA Lamaze, GP Lindstrom, RM Chen-Mayer, HH Liposky, PJ AF Anderson, DL Mackey, EA Lamaze, GP Lindstrom, RM Chen-Mayer, HH Liposky, PJ TI Thermal neutron capture prompt gamma-ray activation analysis facility at the National Center for Neutron Research. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US FDA, Elemental Res Branch HFS 338, Washington, DC 20204 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 132-NUCL BP U22 EP U22 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300132 ER PT J AU Antonucci, JM Stansbury, JW Fowler, BO AF Antonucci, JM Stansbury, JW Fowler, BO TI Improved synthesis of ethyl alpha-hydroxymethylacrylate, a unique isomeric analog of HEMA. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, DMMG, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 37-POLY BP U251 EP U251 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301436 ER PT J AU Ashley, K Raghavan, D Meredith, JC Karim, A AF Ashley, K Raghavan, D Meredith, JC Karim, A TI High throughput dewetting of polystyrene on gradient etched silicon surfaces. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Howard Univ, Dept Chem, Washington, DC 20059 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 295-COLL BP U271 EP U271 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201429 ER PT J AU Beck, CM AF Beck, CM TI Brief look at chemistry in Washington, DC from 1880 to 1925 through the eyes of William F. Hillebrand. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 8-HIST BP U409 EP U409 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202166 ER PT J AU Benner, BA Degrasse, JA AF Benner, BA Degrasse, JA TI On-line trace analysis of human hair: Forensic and health-related applications. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. George Washington Univ, Dept Chem, Washington, DC 20052 USA. RI DeGrasse, Jeffrey/J-1151-2014 OI DeGrasse, Jeffrey/0000-0003-3178-6301 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 93-ANYL BP U92 EP U93 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200420 ER PT J AU Blaauw, M Chen-Mayer, HH AF Blaauw, M Chen-Mayer, HH TI Neutron incoherent scattering as a tool to determine hydrogen concentrations and chemical state in titanium. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Delft Univ Technol, Interfac Reactor Inst, Dept Radiochem, NL-2629 JB Delft, Netherlands. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 115-NUCL BP U19 EP U19 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300115 ER PT J AU Briggman, KA Richter, LJ Stephenson, JC Wallace, WE AF Briggman, KA Richter, LJ Stephenson, JC Wallace, WE TI Determination of molecular structure at polymer interfaces by sum-frequency generation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Opt Technol, Gaithersburg, MD 20899 USA. NIST, Surface & Microanalys Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 119-COLL BP U243 EP U243 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201255 ER PT J AU Brown, CM Soles, CL Lichtenhan, JD Neumann, DA AF Brown, CM Soles, CL Lichtenhan, JD Neumann, DA TI Inelastic neutron scattering of octa-methylsilsesquioxane. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Maryland, NIST, Dept Mech & Nucl Engn, College Pk, MD 20749 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 60-PHYS BP U164 EP U164 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300879 ER PT J AU Bunk, DM Welch, MJ AF Bunk, DM Welch, MJ TI Characterization of iron-containing proteins in human serum. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 43-ANYL BP U85 EP U85 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200370 ER PT J AU Chen, TH Mardis, K Gilson, MK Payne, GF AF Chen, TH Mardis, K Gilson, MK Payne, GF TI Adsorptive separations for the recovery of compounds from renewable resources. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Maryland, Ctr Agr Biotechnol Chem & Biochem Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Gaithersburg, MD USA. Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, College Pk, MD 20742 USA. Univ Maryland, Ctr Agr Biotechnol, College Pk, MD 20742 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 135-IEC BP U432 EP U432 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202311 ER PT J AU Chen-Mayer, HH Lamaze, GP Lindstrom, RM Mildner, DFR AF Chen-Mayer, HH Lamaze, GP Lindstrom, RM Mildner, DFR TI Imaging of neutron incoherent scattering from hydrogen in metals. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 114-NUCL BP U19 EP U19 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300114 ER PT J AU Chin, JW Martin, JW Embree, E Byrd, E AF Chin, JW Martin, JW Embree, E Byrd, E TI Use of integrating spheres as uniform sources for accelerated UV weathering of advanced materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Building Mat Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 74-PMSE BP U339 EP U339 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301939 ER PT J AU Dalton, G AF Dalton, G TI Publishing scientific data for electronic books: Challenges and opportunities. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 48-CINF BP U201 EP U202 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201027 ER PT J AU DeRose, PC Travis, JC Smith, MV Kramer, GW AF DeRose, PC Travis, JC Smith, MV Kramer, GW TI Metal coatings on fused silica and the effects of surface features on the transmittance of optical filters. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 89-ANYL BP U92 EP U92 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200416 ER PT J AU Diallo, MS Glinka, CJ Goddard, WA Johnson, JH AF Diallo, MS Glinka, CJ Goddard, WA Johnson, JH TI Small angle neutron scattering investigations of Suwanee River fulvic acid aggregates in aqueous solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Dept Civil Engn, Pasadena, CA 91125 USA. Howard Univ, Washington, DC 20059 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. CALTECH, Proc Simulat Ctr, Pasadena, CA 91125 USA. Howard Univ, Dept Civil Engn, Washington, DC 20059 USA. NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 184-ENVR BP U345 EP U345 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201806 ER PT J AU Dimeo, RM Neumann, DA AF Dimeo, RM Neumann, DA TI Effects of confinement on rotational tunneling in methyl iodide. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 139-PHYS BP U176 EP U176 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300957 ER PT J AU Elliott, JT Meuse, CW Vanderah, DJ Silin, V Plant, AL AF Elliott, JT Meuse, CW Vanderah, DJ Silin, V Plant, AL TI Hybrid bilayer membranes: Fabrication and characterization of biomimetic surfaces for biosensor applications. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Biomol Mat Grp, Div Biotechnol, Gaithersburg, MD 20899 USA. Georgetown Univ, Dept Chem, Washington, DC 20057 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 207-COLL BP U257 EP U257 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201343 ER PT J AU Feresenbet, E Raghavan, D Holmes, GA AF Feresenbet, E Raghavan, D Holmes, GA TI Influence of silane coupling agent composition on the fiber-matrix interfacial shear strength. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Howard Univ, Dept Chem, Washington, DC 20059 USA. Howard Univ, Div Polymer Sci, Washington, DC 20059 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 158-COLL BP U249 EP U249 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201294 ER PT J AU Ferreiro, V Douglas, JF Karim, A Coulon, G AF Ferreiro, V Douglas, JF Karim, A Coulon, G TI Atomic force microscopy studies of phase ordering in polymer blends and clay-filled systems. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Lille, Lab Struct & Proprietes Etat Solide, Lille, France. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 179-POLY BP U281 EP U281 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301578 ER PT J AU Floyd, CJE Dickens, SH AF Floyd, CJE Dickens, SH TI Effects of diluent monomers on properties of experimental dental polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 62-ANYL BP U88 EP U88 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200389 ER PT J AU Gebremichael, Y Schroeder, TB Glotzer, SC AF Gebremichael, Y Schroeder, TB Glotzer, SC TI Clustering of cooperatively moving monomers in a glass-forming polymer liquid. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 412-PHYS BP U216 EP U216 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301230 ER PT J AU Gilman, JW Morgan, AB Harris, RH Trulove, PC De Long, HC Sutto, TE AF Gilman, JW Morgan, AB Harris, RH Trulove, PC De Long, HC Sutto, TE TI Polymer layered silicate nanocomposites: Thermal stability of organic cationic treatments. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Fire Sci Div, Mat Fire Res Grp, Gaithersburg, MD 20899 USA. USN Acad, Dept Chem, Annapolis, MD 21402 USA. RI Morgan, Alexander/A-9672-2009 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 68-PMSE BP U338 EP U338 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301933 ER PT J AU Gilson, MK David, L Luo, R Mardis, KL Potter, M AF Gilson, MK David, L Luo, R Mardis, KL Potter, M TI Modeling molecular recognition: Theory and application. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Montreal, Dept Inform Rech Operat, Montreal, PQ, Canada. Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 80-PHYS BP U167 EP U167 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300899 ER PT J AU Glotzer, SC AF Glotzer, SC TI Dynamically heterogeneous nature of glass-forming liquids. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 110-PHYS BP U171 EP U172 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300928 ER PT J AU Gonzalez, CA Louis, F Huie, RE Kurylo, MJ AF Gonzalez, CA Louis, F Huie, RE Kurylo, MJ TI Frugal quantum chemist approach to computational kinetics. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Computat Chem Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 296-PHYS BP U199 EP U199 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301114 ER PT J AU Greenberg, RR AF Greenberg, RR TI Sources of uncertainty in instrumental neutron activation analysis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 177-ANYL BP U104 EP U105 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200504 ER PT J AU Greenberg, RR AF Greenberg, RR TI Role of neutron activation analysis in the development and certification of NIST complex-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 Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 158-NUCL BP U26 EP U26 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300158 ER PT J AU Greene, CH Burke, JP Esry, BD AF Greene, CH Burke, JP Esry, BD TI Molecule formation in ultracold three-body collisions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD USA. Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. RI Greene, Chris/C-3821-2011; Esry, Brett/H-7511-2013 OI Greene, Chris/0000-0002-2096-6385; Esry, Brett/0000-0003-3207-8526 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 255-PHYS BP U193 EP U193 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301073 ER PT J AU Grohn, F Bauer, BJ Amis, EJ AF Grohn, F Bauer, BJ Amis, EJ TI Hydrophobically modified dendrimers as inverse micelles: Formation of cylindrical multi-dendrimer nanostructures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 96-PHYS BP U170 EP U170 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300914 ER PT J AU Guenther, F Leigh, S AF Guenther, F Leigh, S TI Errors in both variables for calibration lines. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 178-ANYL BP U105 EP U105 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200505 ER PT J AU Heimer, TA Kleiman, VD Burkey, TJ Heilweil, EJ AF Heimer, TA Kleiman, VD Burkey, TJ Heilweil, EJ TI Self-association reactions studied by broadband ultrafast IR spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. USN, Res Lab, Elect Sci & Opt Technol Div, Washington, DC USA. Univ Memphis, Memphis, TN 38152 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 163-PHYS BP U179 EP U179 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300981 ER PT J AU Hewes, JD AF Hewes, JD TI Investing in new ideas, new technologies, and new markets: The advanced technology program. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Chem & Life Sci Off, ATP, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 26-IEC BP U416 EP U416 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202203 ER PT J AU Huang, TH Stranick, S Tarlov, M AF Huang, TH Stranick, S Tarlov, M TI Fluorescence detection of DNA hybridization based on surface orientation changes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Process Measurements Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Microanalys Sci Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 308-COLL BP U273 EP U273 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201442 ER PT J AU Hudgens, JW Gonzalez, CA AF Hudgens, JW Gonzalez, CA TI Addition and metathesis reactions of chlorine and allene studied by ab initio calculations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 359-PHYS BP U209 EP U209 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301177 ER PT J AU Irikura, KK Johnson, RD AF Irikura, KK Johnson, RD TI Discovering chemical reactions using quantum mechanics. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Proper Div, Gaithersburg, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 329-CHED BP U180 EP U180 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200922 ER PT J AU Irikura, KK AF Irikura, KK TI Data, methods, and software from NIST. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Chem Properties Div, Gaithersburg, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 291-PHYS BP U198 EP U198 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301109 ER PT J AU Johnson, RD AF Johnson, RD TI NIST computational chemistry comparison and benchmark catabase. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 490-PHYS BP U228 EP U228 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301305 ER PT J AU Julienne, PS AF Julienne, PS TI Survey of molecule formation processes from ultracold atoms. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 219-PHYS BP U187 EP U187 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301037 ER PT J AU Kacker, RN AF Kacker, RN TI Interpretation of the guide to the expression of uncertainty in measurement. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 174-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200501 ER PT J AU Karim, A Sehgal, A Amis, EJ AF Karim, A Sehgal, A Amis, EJ TI AFM studies of confined dewetting on gradient patterned surfaces. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 209-POLY BP U286 EP U286 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301608 ER PT J AU Khatri, CA Antonucci, JM Stansbury, JW Schultheisz, CR AF Khatri, CA Antonucci, JM Stansbury, JW Schultheisz, CR TI Synthesis, characterization and evaluation of urethane derivatives of Bis-GMA. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, DMMG, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 321-POLY BP U302 EP U302 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301720 ER PT J AU Klassen, JK AF Klassen, JK TI NIST Mass Spectral Database through the ages. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 59-CINF BP U203 EP U203 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201038 ER PT J AU Kuwana, T Coleman, B Huang, TH Kelly, RS Flynn, JE AF Kuwana, T Coleman, B Huang, TH Kelly, RS Flynn, JE TI CV and FIA study of ions and molecules partitioning into fractured carbon fiber electrodes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Kansas, Dept Chem, Lawrence, KS 66045 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Process Measurements Div, Gaithersburg, MD 20899 USA. Merrimack Coll, Dept Chem, N Andover, MA 01845 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 171-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200498 ER PT J AU Lamaze, GP Chen-Mayer, HH AF Lamaze, GP Chen-Mayer, HH TI Elemental analysis of thin films by neutron depth profiling. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 117-NUCL BP U20 EP U20 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300117 ER PT J AU Leone, SR Amitay, Z Ballard, J AF Leone, SR Amitay, Z Ballard, J TI Coherent control dynamics of rotational and vibrational degrees of freedom in wave packet superposition states. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 278-PHYS BP U196 EP U196 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301096 ER PT J AU Lett, PD Jones, KM Fatemi, F AF Lett, PD Jones, KM Fatemi, F TI Photoassociation spectroscopy of ultracold sodium. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 183-PHYS BP U182 EP U182 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301001 ER PT J AU Levenson, MS AF Levenson, MS TI Statistical experimental design concepts for uncertainty evaluation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 175-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200502 ER PT J AU Lewis, BA Waraksa, CC Saupe, GB Kaschak, DM Schaak, RE Mallouk, TE AF Lewis, BA Waraksa, CC Saupe, GB Kaschak, DM Schaak, RE Mallouk, TE TI Photoinduced electron transfer in porphyrin-oxide semiconductor-viologen triads. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Penn State Univ, Dept Chem, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Proc Sensing Grp, Gaithersburg, MD USA. RI Mallouk, Thomas/K-7391-2012 OI Mallouk, Thomas/0000-0003-4599-4208 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 35-IEC BP U418 EP U418 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202212 ER PT J AU Lin, M AF Lin, M TI Using neutron scattering to study hydrocarbons. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 51-PETR BP U146 EP U146 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300795 ER PT J AU Lindstrom, RM Chen-Mayer, HH Paul, RL AF Lindstrom, RM Chen-Mayer, HH Paul, RL TI Preparation and characterization of standards for hydrogen in titanium alloy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 113-NUCL BP U19 EP U19 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300113 ER PT J AU Manion, JA Tsang, W Anikeev, V AF Manion, JA Tsang, W Anikeev, V TI Chemical kinetics in supercritical water: A stirred reactor with direct substrate injection and on-line sampling. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 406-PHYS BP U215 EP U215 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301224 ER PT J AU Melinger, JS Kleiman, VD McMorrow, D Grohn, F Bauer, BJ Amis, EJ AF Melinger, JS Kleiman, VD McMorrow, D Grohn, F Bauer, BJ Amis, EJ TI Ultrafast dynamics of gold nanoparticles embedded in a dendrimer host. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USN, Res Lab, Washington, DC 20375 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 429-PHYS BP U219 EP U219 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301247 ER PT J AU Meuse, CW AF Meuse, CW TI Molecular structure of biomolecular surfaces. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 288-COLL BP U269 EP U270 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201422 ER PT J AU Mitchell, JF Osborn, R Gray, KE Berger, A Argyriou, DN Bader, SD Ling, C Millburn, JE Sinha, S Seeck, O Vasiliu-Doloc, L Lynn, J AF Mitchell, JF Osborn, R Gray, KE Berger, A Argyriou, DN Bader, SD Ling, C Millburn, JE Sinha, S Seeck, O Vasiliu-Doloc, L Lynn, J TI Neutron scattering investigations of magnetism and structure in layered perovskite manganites SrO(La1-xSrxMnO3)(2). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Ling, Chris D/B-2228-2009; Osborn, Raymond/E-8676-2011; Bader, Samuel/A-2995-2013; Berger, Andreas/D-3706-2015 OI Ling, Chris D/0000-0003-2205-3106; Osborn, Raymond/0000-0001-9565-3140; Berger, Andreas/0000-0001-5865-6609 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 24-PHYS BP U159 EP U159 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300843 ER PT J AU Morgan, AB Antonucci, JM VanLandingham, MR Harris, RH Kashiwagi, T AF Morgan, AB Antonucci, JM VanLandingham, MR Harris, RH Kashiwagi, T TI Thermal and flammability properties of a silica-PMMA nanocomposite. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymer, DMMG, Gaithersburg, MD USA. Natl Inst Stand & Technol, Building & Fire Res Lab, Gaithersburg, MD USA. Natl Inst Stand & Technol, Mat Fire Res Grp, Gaithersburg, MD USA. RI Morgan, Alexander/A-9672-2009 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 67-PMSE BP U338 EP U338 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301932 ER PT J AU Morgan, AB Gilman, JW Harris, RH Jackson, CL Wilkie, CA Zhu, J AF Morgan, AB Gilman, JW Harris, RH Jackson, CL Wilkie, CA Zhu, J TI Flammability of polystyrene-clay nanocomposites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Fire Sci Div, Mat Fire Res Grp, Gaithersburg, MD 20899 USA. Marquette Univ, Dept Chem, Milwaukee, WI 53233 USA. RI Morgan, Alexander/A-9672-2009 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 64-PMSE BP U338 EP U338 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301929 ER PT J AU Mountain, RD AF Mountain, RD TI Molecular dynamics study of voids, clusters, and solutes in supercritical fluids. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 139-COMP BP U297 EP U297 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201590 ER PT J AU Nakatani, AI Ivkov, R Papanek, P Yang, HH Gerspacher, M AF Nakatani, AI Ivkov, R Papanek, P Yang, HH Gerspacher, M TI Concentration dependence of bound polymer dynamics by inelastic neutron scattering. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Sid Richardson Carbon Co, Ft Worth Res Ctr, Ft Worth, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 273-COLL BP U267 EP U267 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201407 ER PT J AU Nguyen, T Chin, JW Aouadi, DK Raghavan, D AF Nguyen, T Chin, JW Aouadi, DK Raghavan, D TI Sorption and diffusion of alkaline solution in organic coatings at ambient and elevated temperatures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Building & Fire Res Lab, Organ Building Mat Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Building Mat Grp, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Div Polymer Sci, Washington, DC 20059 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 90-PMSE BP U342 EP U342 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301955 ER PT J AU Nguyen, T Martin, J Byrd, E Embree, N AF Nguyen, T Martin, J Byrd, E Embree, N TI Effects of relative humidity on photodegradation of acrylic melamine coatings: A quantitative study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Building Mat Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 18-PMSE BP U330 EP U330 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301883 ER PT J AU O'Hern, CS Langer, SA Liu, AJ Nagel, SR AF O'Hern, CS Langer, SA Liu, AJ Nagel, SR TI Is the glass transition a jamming transition?. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Angeles, Dept Chem, Los Angeles, CA 90095 USA. Univ Chicago, Dept Chem, Los Angeles, CA USA. Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. RI O'Hern, Corey/I-3459-2014 OI O'Hern, Corey/0000-0002-8272-5640 NR 0 TC 0 Z9 0 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 78-PHYS BP U167 EP U167 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300897 ER PT J AU Olsen, KG Steel, AB Tarlov, MJ AF Olsen, KG Steel, AB Tarlov, MJ TI Immobilized DNA electrodes: The effect of target length on DNA hybridization. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Loyola Coll, Dept Chem, Baltimore, MD 21210 USA. Gene Log Inc, DNA Chip R&D, Columbia, MD USA. Natl Inst Stand & Technol, Proc Measurements Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 310-COLL BP U273 EP U273 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201444 ER PT J AU Pait, AS Nelson, J AF Pait, AS Nelson, J TI Use of the killifish Fundulus heteroclitus to assess endocrine disruption in the Chesapeake Bay. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Ctr Coastal Monitoring & Assessment, Silver Spring, MD 20910 USA. Univ Maryland, Dept Entomol, Baltimore, MD 21201 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 138-AGRO BP U68 EP U68 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200291 ER PT J AU Parris, RM Welch, MJ Schantz, MM AF Parris, RM Welch, MJ Schantz, MM TI Quantification of measurement uncertainty for organic analytical measurements: Current practice - Current/future needs. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 180-ANYL BP U105 EP U105 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200507 ER PT J AU Paul, RL AF Paul, RL TI Development of a radiochemical neutron activation analysis procedure to measure sulfur in steels. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 155-NUCL BP U25 EP U25 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300155 ER PT J AU Poskrebyshev, G Neta, P Huie, RE AF Poskrebyshev, G Neta, P Huie, RE TI Equilibrium constant of the reaction OH+HNO3=H2O+NO3inaqueous solution. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 306-PHYS BP U201 EP U201 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301124 ER PT J AU Roitberg, AE Worthington, SE Krauss, M AF Roitberg, AE Worthington, SE Krauss, M TI MD/QN study of the chorismate mutase catalyzed Claisen rearrangement reaction. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Ctr Adv Res Biotechnol, Div Biotechnol, Rockville, MD 20850 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 158-COMP BP U300 EP U300 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201609 ER PT J AU Rumble, J AF Rumble, J TI Chemical informatics careers at NIST: Reliable data for chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 32-CINF BP U199 EP U199 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201012 ER PT J AU Sander, LC Wise, SA AF Sander, LC Wise, SA TI Mew standard reference material for lc column evaluation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 23-ANYL BP U82 EP U82 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200350 ER PT J AU Saupe, GB Tarlov, MJ AF Saupe, GB Tarlov, MJ TI Effect of DNA probe structure and target length on hybridization kinetics and efficiency of DNA self-assembled monolayers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 309-COLL BP U273 EP U273 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201443 ER PT J AU Schantz, MM Parris, RM Wise, SA AF Schantz, MM Parris, RM Wise, SA TI Performance-based quality assurance program for the analysis of PAHs, PCB congeners, and chlorinated pesticides in marine tissue and sediment samples. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 98-ANYL BP U93 EP U93 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200425 ER PT J AU Schmidt, G Nakatani, A Butler, PD Karim, A Han, CC AF Schmidt, G Nakatani, A Butler, PD Karim, A Han, CC TI Viscoelastic polymer clay solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Butler, Paul/D-7368-2011 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 274-COLL BP U267 EP U267 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201408 ER PT J AU Scott, GI Fulton, M Kucklick, J Bearden, D Stozier, ED Leight, AK Key, PB Daugomah, JW Wirth, EF Delorenzo, MG Chandler, GT AF Scott, GI Fulton, M Kucklick, J Bearden, D Stozier, ED Leight, AK Key, PB Daugomah, JW Wirth, EF Delorenzo, MG Chandler, GT TI Ecotoxicological assessment of agricultural nonpoint source pesticide runoff impacts on living marine resources of South Carolina and south Florida watersheds. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, NOS, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Univ S Carolina, Sch Publ Hlth, Columbia, SC 29208 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 160-AGRO BP U72 EP U72 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200313 ER PT J AU Skrtic, D Antonucci, JM Eanes, DE AF Skrtic, D Antonucci, JM Eanes, DE TI Polymer matrix effects on the properties of amorphous calcium phosphate-filled composites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, PRC, ADAHF, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, DMMG, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 311-POLY BP U301 EP U301 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301710 ER PT J AU Smeller, JM AF Smeller, JM TI Quantifying uncertainty in an EDTA titration. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 179-ANYL BP U105 EP U105 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200506 ER PT J AU Smith, AP Meredith, JC Amis, EJ Karim, A AF Smith, AP Meredith, JC Amis, EJ Karim, A TI Morphological characterization of symmetric diblock copolymers via novel combinatorial methods. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 316-PMSE BP U376 EP U376 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091302181 ER PT J AU Starr, FW Schroeder, TB Glotzer, SC AF Starr, FW Schroeder, TB Glotzer, SC TI Dynamics of a filled polymer melt from molecular dynamics simulations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RI Starr, Francis/C-7703-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 553-PHYS BP U237 EP U237 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301367 ER PT J AU Sung, LP Nadal, ME Stutzman, P McKnight, ME AF Sung, LP Nadal, ME Stutzman, P McKnight, ME TI Characterization of coating microstructure using laser scanning confocal microscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Bldg Mat Div, Gaithersburg, MD 20899 USA. Univ Maryland, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 148-PMSE BP U350 EP U350 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091302013 ER PT J AU Tiesinga, E AF Tiesinga, E TI Ultracold molecule formation via two-body resonances. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 254-PHYS BP U193 EP U193 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301072 ER PT J AU Trevino, SF AF Trevino, SF TI Methyl group rotations in solid nitromethane. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USA, Res Lab, Polymer Res Branch, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 116-NUCL BP U19 EP U20 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300116 ER PT J AU Tsang, W Orchard, Q AF Tsang, W Orchard, Q TI High temperature gas phase kinetics. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 264-PHYS BP U194 EP U194 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301082 ER PT J AU Turk, GC AF Turk, GC TI Assignment of certified value and uncertainty for the NIST SRM 3100 series of single-element standard solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 182-ANYL BP U105 EP U105 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200509 ER PT J AU Udovic, TJ Trevino, SF Young, SK Crawford, MK Sun, Q AF Udovic, TJ Trevino, SF Young, SK Crawford, MK Sun, Q TI Characterization of the interactions of Nafion membranes and water using neutron scattering techniques. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. USA, Res Lab, Polymer Res Branch, Adelphi, MD 20783 USA. NIST, Gaithersburg, MD 20899 USA. EI Du Pont Nemours & Co, Wilmington, DE USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 315-COLL BP U274 EP U274 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201449 ER PT J AU Valincius, G Vilker, V Reipa, V AF Valincius, G Vilker, V Reipa, V TI Electrochemical properties of new binary metal oxide electrodes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 182-COLL BP U253 EP U253 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201318 ER PT J AU van Zee, RD Miller, CC Stephenson, JC AF van Zee, RD Miller, CC Stephenson, JC TI Mechanism of the reaction, CH4+O(D-1(2)) -> 2 CH3+OH, studied by ultrafast and state-resolved photolysis/probe spectroscopy of the CH4 center dot O-3 van der Waals complex. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 447-PHYS BP U222 EP U222 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301263 ER PT J AU Vanderah, DJ Pham, GP Springer, SK Silin, V Zeiger, DN Meuse, CW AF Vanderah, DJ Pham, GP Springer, SK Silin, V Zeiger, DN Meuse, CW TI Structural variability of the self-assembled monolayers (SAMS) of HS(CH2CH2O)(X)CNH2N+1, X=3-8 and N=1, 10, 18, on gold. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Georgetown Univ, Washington, DC 20057 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 293-COLL BP U270 EP U270 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201427 ER PT J AU VanLandingham, MR Villarrubia, JS Meyers, GF AF VanLandingham, MR Villarrubia, JS Meyers, GF TI Nanoindentation of polymers: Overview. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Building & Fire Res Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Mfg Engn Lab, Gaithersburg, MD 20899 USA. Dow Chem Co, Midland, MI 48674 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 3-POLY BP U246 EP U246 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301402 ER PT J AU Vetter, T AF Vetter, T TI Stepwise approach to quantification of uncertainty in analytical measurements. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 176-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200503 ER PT J AU Vetter, T AF Vetter, T TI Quantifying uncertainty in analytical measurement: The new Eurachem/CITAC Guide. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 173-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200500 ER PT J AU Villanueva, M Olsen, KG Steel, AB Tarlov, MJ AF Villanueva, M Olsen, KG Steel, AB Tarlov, MJ TI DNA hybridization on electrode surfaces. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Loyola Coll, Dept Chem, Baltimore, MD 21210 USA. Natl Inst Stand & Technol, Process Sensing Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 132-CHED BP U144 EP U144 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200726 ER PT J AU Waddell, EA Barker, SLR Rose, DJ Locascio, LE Kramer, GW AF Waddell, EA Barker, SLR Rose, DJ Locascio, LE Kramer, GW TI Laser ablation of polymer substrates for the fabrication of microfluidic devices. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NIST, Process Measurements Div, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 86-ANYL BP U91 EP U92 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200413 ER PT J AU Wang, H Han, CC AF Wang, H Han, CC TI Cessation of spherulitic growth in phase-separating polyolefin blends. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 466-POLY BP U323 EP U323 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301865 ER PT J AU Waraksa, CC Lewis, BA Saupe, GB Kaschak, DM Schaak, RE Mallouk, TE AF Waraksa, CC Lewis, BA Saupe, GB Kaschak, DM Schaak, RE Mallouk, TE TI Growth and characterization of an electron staircase with exfoliated layered semiconductor sheets. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Penn State Univ, Dept Chem, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Process Sensing Grp, Gaithersburg, MD USA. RI Mallouk, Thomas/K-7391-2012 OI Mallouk, Thomas/0000-0003-4599-4208 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 185-IEC BP U440 EP U440 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202361 ER PT J AU Watters, RL AF Watters, RL TI Impact of a unified approach to estimating measurement uncertainty of the international comparability of measurements and standards. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Technol Serv, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 172-ANYL BP U104 EP U104 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200499 ER PT J AU Whung, PY Robarge, W AF Whung, PY Robarge, W TI Gaseous ammonia emissions near poultry houses and swine operations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Off Atmospher & Ocean Res, Off Sci Support, Silver Spring, MD 20910 USA. N Carolina State Univ, Dept Soil Sci, Raleigh, NC 27695 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 156-AGRO BP U73 EP U73 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200319 ER PT J AU Worthington, SE Roitberg, AE Krauss, M AF Worthington, SE Roitberg, AE Krauss, M TI Chorismate mutase reactivity: An ab initio study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 109-COMP BP U293 EP U293 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201560 ER PT J AU Wright, SC Amy, GL Pellegrino, J Ranville, JF AF Wright, SC Amy, GL Pellegrino, J Ranville, JF TI Characterizing complex solute mixtures using field flow fractionation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Dept Civil & Environm Engn, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Colorado Sch Mines, Dept Chem & Geochem, Golden, CO 80401 USA. RI Ranville, James/H-1428-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 78-ENVR BP U328 EP U328 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201700 ER PT J AU Yoon, Y Yoon, L Amy, G Liang, S Pellegrino, J AF Yoon, Y Yoon, L Amy, G Liang, S Pellegrino, J TI Use of surfactants to modify negatively charged ultrafiltration membranes for perchlorate removal. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Dept Civil & Environm Engn, Boulder, CO 80309 USA. Metropolitan Water Dist S Calif, Los Angeles, CA USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 77-ENVR BP U328 EP U328 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201699 ER PT J AU Young, SK Trevino, SF Tan, NB Paul, R AF Young, SK Trevino, SF Tan, NB Paul, R TI Utilization of prompt gamma neutron activation analysis in the evaluation of various counterion Nafion (TM) membranes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USA, Ballist Res Lab, Polymers Res Branch, Aberdeen Proving Ground, MD 21005 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 134-NUCL BP U22 EP U22 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300134 ER PT J AU Yu, LL AF Yu, LL TI Uncertainty budgeting in the certification of reference materials by ICP-MS. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Spectrochem Methods Grp, Gaithersburg, MD 20899 USA. RI Yu, Lee/N-7263-2015 OI Yu, Lee/0000-0002-8043-6853 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 183-ANYL BP U105 EP U105 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200510 ER PT J AU Zeisler, R AF Zeisler, R TI Determination of homogeneity in reference materials by INAA. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Analyt Chem, Nucl Methods Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 159-NUCL BP U26 EP U26 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300159 ER PT J AU Johns-Krull, CM Valenti, JA Linsky, JL AF Johns-Krull, CM Valenti, JA Linsky, JL TI An IUE atlas of pre-main-sequence stars. II. Far-ultraviolet accretion diagnostics in T Tauri stars SO ASTROPHYSICAL JOURNAL LA English DT Review DE accretion, accretion disks; circumstellar matter; stars : activity; stars : pre-main-sequence ID SOLAR-TYPE STARS; X-RAY SOURCES; MAGNETOCENTRIFUGALLY DRIVEN FLOWS; YOUNG STELLAR OBJECTS; DISK ACCRETION; CHROMOSPHERIC ACTIVITY; MAGNETIC ACTIVITY; BP TAURI; SYNCHRONIZED BINARIES; ATOMIC DATABASE AB We use our ultraviolet (UV) atlas of pre-main-sequence stars constructed from all useful, short-wavelength, low-resolution spectra in the International Ultraviolet Explorer (IUE) satellite Final Archive to analyze the short-wavelength UV properties of 49 T Tauri stars (TTSs). We compare the line and continuum fluxes in these TTSs with each other and with previously published parameters of these systems, including rotation rate, infrared excess, and mass accretion rate. The short-wavelength continuum in the classical TTSs (CTTSs) appears to originate in a similar to 10,000 K optically thick plasma, while in the naked TTSs (NTTSs-stars without dusty disks) the continuum appears to originate in the stellar atmosphere. We show that all of the TTSs in our sample lie in the regime of "saturated" magnetic activity due to their small Rossby numbers. However, while some of the TTSs show emission line surface fluxes consistent with this saturation level, many CTTSs show significantly stronger emission than predicted by saturation. In these stars, the emission line luminosity in the high ionization lines present in the spectrum between 1200 and 2000 a correlates well with the mass accretion rate. Therefore, we conclude that the bulk of the short-wavelength emission seen in CTTSs results from accretion related processes and not from dynamo-driven magnetic activity. Using CTTSs with known mass accretion rates, we calibrate the relationship between M and L-Crv to derive the mass accretion rate for some CTTSs which for various reasons have never had their mass accretion rates measured. Finally, several of the CTTSs show strong emission from molecular hydrogen. While emission from H-2 cannot form in gas at a temperature of similar to 10(5) K, the strength of the molecular hydrogen emission is nevertheless well correlated with all the other emissions displayed in the IUE short-wavelength bandpass. This suggests that the H-2 emission is in fact fluorescent emission pumped by the emission (likely Ly alpha) from hotter gas. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. RP Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM cmj@ssl.berkeley.edu; valenti@stsci.edu; jlinsky@jila.colorado.edu NR 101 TC 104 Z9 106 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 815 EP 833 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600030 ER PT J AU Jablonski, A Powell, CJ AF Jablonski, A Powell, CJ TI Effects of interaction potential on elastic-electron-scattering parameters in surface-sensitive electron spectroscopies SO SURFACE SCIENCE LA English DT Article DE aluminum; Auger electron spectroscopy; carbon; computer simulations; copper; electron-solid interactions; electron-solid interactions, scattering, diffraction; electron solid scattering and transmission - elastic; gold; Monte Carlo simulations; silver; X-ray photoelectron spectroscopy ID MEAN FREE PATHS; RAY-PHOTOELECTRON-SPECTROSCOPY; MEDIUM-ENERGY ELECTRONS; ANGULAR-DISTRIBUTION; RELATIVE INTENSITIES; POLYCRYSTALLINE SOLIDS; ATTENUATION LENGTHS; ESCAPE PROBABILITY; CORRECTION FORMULA; AUGER ELECTRONS AB The interaction potential for elastic-scattering of electrons by atoms influences the magnitudes of calculated elastic-scattering cross sections. We have investigated the influence of two choices of interaction potential? the Thomas-Fermi-Dirac (TFD) potential and the Dirac-Hartree-Fock-Slater (DHFS) potential, on the differential elastic-scattering cross sections and the total elastic-scattering cross sections for the elastic-scattering of 1000 eV electrons by six representative elements (Be, C, Al, Cu, Ag, and Au). The differential cross sections for the two potentials varied by up to a factor of three for scattering angles less than 30 degrees, while total cross sections varied between 15 and 61%. In contrast, transport cross sections (which emphasize large-angle scattering events) calculated from the two potentials differed by between 1 and 8.5% for the six elements. We compared results of Monte Carlo calculations of elastic backscattering probabilities of normally incident 1000 eV electrons on Be, C, Al, Cu, Ag, and Au with the two potentials, and found percentage differences in these probabilities varying between 1.2 and 9.4% for emission angles of 45 +/- 10 degrees. Monte Carlo calculations were also made of signal intensities in X-ray photoelectron spectroscopy (XPS), emission depth distribution functions (EDDFs) in XPS, and mean escape depths (MEDs) in XPS for selected photoelectron lines from Be, C, Al, Cu, Ag, and Au using the TFD and DHFS potentials and a common XPS configuration. The percentage deviations in the results for the two potentials did not exceed 2% for the signal intensities, were generally less than 10% for the emission depth distribution functions, and less than 2.5% for the mean escape depths. The lack of sensitivity of the Monte Carlo results to interaction potential is due to the fact that small-angle elastic-scattering events are not significant in the transport of signal electrons in XPS and Auger electron spectroscopy (AES). We point out that XPS signal intensities and EDDFs and MEDs for both XPS and AES can be calculated from a solution of the Boltzmann equation within the transport approximation. This approach is useful for the correction of elastic-scattering effects in quantitative AES and XPS because the only parameter used to describe elastic-scattering effects is the transport cross section (which is relatively insensitive to the choice of interaction potential). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. RP Powell, CJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 65 TC 15 Z9 15 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 20 PY 2000 VL 463 IS 1 BP 29 EP 54 DI 10.1016/S0039-6028(00)00587-2 PG 26 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 349CV UT WOS:000089027000008 ER PT J AU King, DB Butler, JH Montzka, SA Yvon-Lewis, SA Elkins, JW AF King, DB Butler, JH Montzka, SA Yvon-Lewis, SA Elkins, JW TI Implications of methyl bromide supersaturations in the temperate North Atlantic Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ORGANIC-COMPOUNDS; TROPICAL TROPOPAUSE; ATMOSPHERIC CH3BR; PACIFIC-OCEAN; WATER; DEGRADATION; SEAWATER; SEA AB Methyl bromide saturation anomalies measured in the springtime North Atlantic and summertime North Pacific Oceans during 1998 revealed persistent supersaturations in the temperate waters of the northeastern Atlantic but undersaturations in tropical waters of both oceans. A comparison of data from this study with those from a previous cruise to the northeastern Atlantic suggests that methyl bromide is cycled seasonally in these waters and perhaps in all temperate open-ocean waters. This means that the calculated net flux of methyl bromide into the oceans is slightly less negative than previously reported. With these new insights we estimate that the global air-sea flux of methyl bromide ranges from -11 to -20 Gg yr-l Data combined from this and three previous cruises support a flux dependence upon sea surface temperature, as reported recently by Groszko and Moore [1998]. Whereas sea surface temperature can account for 40-70% of the observed variability in methyl bromide globally, it is able to reproduce only a small fraction of the observed seasonal cycle in the temperate northeastern Atlantic. The development of reliable predictions of air-sea fluxes of methyl bromide will require information on additional variables as well. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP King, DB (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80303 USA. EM dking@cmdl.noaa.gov RI Yvon-Lewis, Shari/E-4108-2012; OI Yvon-Lewis, Shari/0000-0003-1378-8434; Montzka, Stephen/0000-0002-9396-0400 NR 27 TC 28 Z9 29 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 AUG 16 PY 2000 VL 105 IS D15 BP 19763 EP 19769 DI 10.1029/2000JD900251 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600001 ER PT J AU Crosley, DR Goldan, PD Nicks, DK Benner, RL Farwell, SO MacTaggart, DL Bamsberger, WL AF Crosley, DR Goldan, PD Nicks, DK Benner, RL Farwell, SO MacTaggart, DL Bamsberger, WL TI Gas-Phase Sulfur Intercomparison Experiment 2: Analysis and conclusions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMILUMINESCENCE DETECTOR AB A diffusion denuder, total sulfur chemiluminescence detector instrument for the measurement of SO2 was tested as the second part of the Gas-Phase Sulfur Intercomparison Experiment (GASIE 2). The SO2 at mixing ratios between 27 and 182 parts per trillion by volume (pptv) was Provided by a dynamic dilution apparatus. The data were kept blind from the other party and analyzed by two independent referees. The following was concluded: (1) The independent calibrations of each system are within a few percent. (2) The precision on any one day is better than day-to-day variability. (3) Runs in dry air show a small but significant nonzero intercept in correlation plots. (4) No effects of adding NO2 + O-3 or CO2 + CH4 + CO + dimethylsulfide are distinguishable. (5) A small but significant effect due to added H2O is evident in both slope and intercept, but the source could not be discerned. (6) On any one day the systems can distinguish among 0, 20, and 40 pptv, but because of day-to-day variability, they can only distinguish among 0, 30, and 60 pptv on different days. C1 SRI Int, Mol Phys Lab, Menlo Pk, CA 94025 USA. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO 80303 USA. Univ Alaska, Dept Chem & Biochem, Fairbanks, AK 99701 USA. S Dakota Sch Mines & Technol, Atmospher Analyt Chem Lab, Rapid City, SD 57701 USA. Washington State Univ, Lab Atmospher Res, Pullman, WA 99163 USA. RP Crosley, DR (reprint author), SRI Int, Mol Phys Lab, 333 Ravenswood Ave, Menlo Pk, CA 94025 USA. EM drc@mplvax.sri.com; pgoldan@al.noaa.gov; dnicks@al.noaa.gov; fflrb@aurora.alaska.edu; sfarwell@msmailgw.sdsmt.edu; dougmactaggart@earthlink.net; bamesber@wsu.edu NR 8 TC 1 Z9 1 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2000 VL 105 IS D15 BP 19787 EP 19793 DI 10.1029/2000JD900008 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600004 ER PT J AU Hurst, DF Dutton, GS Romashkin, PA Elkins, JW Herman, RL Moyer, EJ Scott, DC May, RD Webster, CR Grecu, J Loewenstein, M Podolske, JR AF Hurst, DF Dutton, GS Romashkin, PA Elkins, JW Herman, RL Moyer, EJ Scott, DC May, RD Webster, CR Grecu, J Loewenstein, M Podolske, JR TI Comparison of in situ N2O and CH4 measurements in the upper troposphere and lower stratosphere during STRAT and POLARIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TOTAL HYDROGEN BUDGET; NITROUS-OXIDE; SPECTROMETER AB Nitrous oxide (N2O) and methane (CH4) were measured in the upper troposphere and lower stratosphere by multiple instruments aboard the NASA ER-2 aircraft during the 1995-1996 Stratospheric Tracers of Atmospheric Transport (STRAT) and 1997 Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) campaigns. Differences between coincidental, in situ measurements are examined to evaluate the agreement and variability in the agreement between these instruments during each flight. Mean N2O measurement differences for each flight were much smaller than limits calculated from quoted values of N2O measurement accuracy and for all but two flights were less than or equal to 8.7 ppb (3.5%). Mean CH4 measurement differences for flights were similarly much smaller than calculated limits and for all but three flights were less than or equal to 65 ppb (4.4%). Typical agreement between instruments during flights averaged 6.2 ppb (2.5%) for N2O and 43 ppb (2.9%) for CH4. In contrast, for about half of the flights, the variability of N2O and CH4 measurement differences exceeded limits calculated from quoted values of measurement precision. The typical measurement difference variability (lo) during a flight averaged +/-8.0 ppb for N2O and +/-43 ppb (2.9%) for CH4. For some flights, large differences or variations in differences are attributable to the poor measurement accuracy or precision of one instrument. It is demonstrated that small offsets between the computer clocks of these instruments can result in significant differences between their "coincidental" N2O and CH4 data, especially when there is high spatial variability in tracer abundance along a flight track. C1 Natl Ocean & Atmospher Adm, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hurst, DF (reprint author), Natl Ocean & Atmospher Adm, Climate Monitoring & Diagnost Lab, MS R-CMDL1,325 Broadway, Boulder, CO 80303 USA. EM dhurst@cmdl.noaa.gov RI Herman, Robert/H-9389-2012; Hurst, Dale/D-1554-2016 OI Herman, Robert/0000-0001-7063-6424; Hurst, Dale/0000-0002-6315-2322 NR 16 TC 5 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2000 VL 105 IS D15 BP 19811 EP 19822 DI 10.1029/2000JD900218 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600006 ER PT J AU Miller, SD Stephens, GL Drummond, CK Heidinger, AK Partain, PT AF Miller, SD Stephens, GL Drummond, CK Heidinger, AK Partain, PT TI A multisensor diagnostic satellite cloud property retrieval scheme SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR-RADIATION MEASUREMENTS; EFFECTIVE PARTICLE RADIUS; CIRRUS CLOUDS; OPTICAL-THICKNESS; LIGHT-SCATTERING; INFRARED OBSERVATIONS; ICE CRYSTALS; MU-M; FIRE; TEMPERATURE AB Active sensor data, in the form of lidar and radar cloud vertical boundaries, are used as a priori information to passive sensor satellite retrievals of cloud optical depth and effective particle radius. Correct placement of cloud in the vertical eliminates the need to approximate cloud height from multispectral passive techniques and is shown to improve uncertainties in nighttime retrievals of thin cirrus in excess of 30%. The new method is exemplified by two case studies using imager data from GOES but remains valid for any passive/active remote sensing application. A strength of this method is its ability to diagnose components of the retrieval uncertainty and thereby quantify retrieval performance. Errors associated with the forward model and measurement uncertainties, and an independent validation of the retrieval, are discussed. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Ford Motor Co, Dearborn, MI 48126 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. RP Miller, SD (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. EM miller@atmos.colostate.edu RI Heidinger, Andrew/F-5591-2010 OI Heidinger, Andrew/0000-0001-7631-109X NR 63 TC 34 Z9 34 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2000 VL 105 IS D15 BP 19955 EP 19971 DI 10.1029/2000JD900273 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600018 ER PT J AU Skamarock, WC Powers, JG Barth, M Dye, JE Matejka, T Bartels, D Baumann, K Stith, J Parrish, DD Hubler, G AF Skamarock, WC Powers, JG Barth, M Dye, JE Matejka, T Bartels, D Baumann, K Stith, J Parrish, DD Hubler, G TI Numerical simulations of the July 10 Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone/Deep Convection Experiment convective system: Kinematics and transport SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID REDISTRIBUTION; THUNDERSTORM; STORM; CO AB The observed July 10, 1996, Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone (STERAO) convective system is broadly reproduced in a nonhydrostatic cloud model simulation using an idealized horizontally homogeneous sounding and no terrain. System evolution from a multicellular line to a supercell, along with line orientation, anvil structure, horizontal wind fields, depth of convection, and derived radar reflectivity, compares well with observations. Simulated passive tracer transport of CO and ozone generally agrees with aircraft measurements and shows a small amount of entrainment of environmental air in the updrafts, and a small amount of dilution occurring with transport downwind in the anvil; the entrainment and dilution are less pronounced in the supercell stage. The horizontally integrated vertical flux divergence for CO in the simulation shows a net gain at almost all levels above 8 km mean sea level (msl). The rate of increase of CO mass above 8 km varies significantly in time, with a peak at early times, followed by a decline and minimum as the system transitions to a supercell and a steady increase as the supercell matures. Trajectory analyses show that updrafts in the simulation are ingesting air from a layer spanning from 2 km to 3.5 km msl (from 0.5 to 2 km above the surface). The residence times for parcels in the updraft varies from just under 10 min to more than 20 min, with most parcels taking approximately 10 min to ascend to the anvil. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, Severe Storms Lab, Boulder, CO 80303 USA. Univ N Dakota, Dept Atmospher Sci, Grand Pks, ND USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Skamarock, WC (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM skamaroc@ucar.edu RI Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010 OI Parrish, David/0000-0001-6312-2724 NR 18 TC 42 Z9 42 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2000 VL 105 IS D15 BP 19973 EP 19990 DI 10.1029/2000JD900179 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600019 ER PT J AU Easterling, DR Karl, TR Gallo, KP Robinson, DA Trenberth, KE Dai, A AF Easterling, DR Karl, TR Gallo, KP Robinson, DA Trenberth, KE Dai, A TI Observed climate variability and change of relevance to the biosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GRIDPOINT TEMPERATURE ANOMALIES; UNITED-STATES; RADIOSONDE VALIDATION; VEGETATION COVER; AIR-TEMPERATURE; SNOW COVER; AVHRR DATA; TRENDS; SATELLITE; SURFACE AB In this paper we review the current instrumental evidence regarding climate variations and change during the 20th century emphasizing those changes that are likely to have direct interactions with the biosphere. Three basic questions are addressed: (1) Is the climate getting warmer, (2) is the hydrologic cycle changing, and (3) is the climate becoming more extreme. Based on global near-surface temperature measurements for the 20th century, it is clear that a warming of similar to 0.5 degrees C has occurred. More importantly for biospheric systems, however, are the observed asymmetric changes in daily maximum and minimum temperature? with the minimum temperatures increasing at a rate approximately twice that of the maximum temperature. Other temperature-sensitive measures, such as glacial and snow cover extent, reinforce the observed temperature trends. Examination of the hydrologic cycle indicates that changes also appear to be occurring, although less confidence can be placed on these analyses than those for temperature. Recent studies suggest that precipitation has increased in higher latitudes, particularly in the Northern Hemisphere. Increases in cloudiness, atmospheric water vapor, and changes in stream flow also suggest that changes to a more vigorous hydrologic cycle are taking place. The final question regarding climate extremes is much more difficult to assess due to a lack of high temporal resolution climate databases. Of the few studies that have been performed, however, there is evidence that precipitation extremes, particularly heavy rainfall events, are increasing in the United States and Australia, also suggesting an enhanced hydrologic cycle as the planet warms. C1 NOAA, Natl Climate Data Ctr, Asheville, NC 28801 USA. Rutgers State Univ, Dept Geog, New Brunswick, NJ 08903 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Easterling, DR (reprint author), NOAA, Natl Climate Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. EM deasterl@ncdc.noaa.gov RI Gallo, Kevin P./F-5588-2010; Trenberth, Kevin/A-5683-2012; Dai, Aiguo/D-3487-2009 OI Trenberth, Kevin/0000-0002-1445-1000; NR 48 TC 62 Z9 66 U1 0 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2000 VL 105 IS D15 BP 20101 EP 20114 DI 10.1029/2000JD900166 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 347LG UT WOS:000088930600027 ER PT J AU Burkholder, JB Mills, M McKeen, S AF Burkholder, JB Mills, M McKeen, S TI Upper limit for the UV absorption cross sections of H2SO4 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GAS-PHASE REACTION; SULFURIC-ACID; MODEL; STRATOSPHERE; VAPOR; WATER; SO3 AB An upper limit for the gas phase absorption cross sections for H2SO4 over the wavelength range 195 to 330 nm has been determined. Absorption measurements were made using a diode array spectrometer and a 100 cm long heated absorption cell. Gas phase H2SO4 was generated in a gas flow by titrating (equilibrating)known amounts of SO, via the reaction SO3 + H2O <----> H2SO4 (3) at elevated temperatures, similar to 500 K. Upper limits to the H2SO4 absorption cross sections were obtained, < 1 x 10(-21) cm(2) molecule(-1), and provide an upper limit to the atmospheric photolysis rate of H2SO4. The implications of this cross section limit to stratospheric sulfur chemistry are discussed. C1 NOAA, Boulder, CO 80303 USA. Univ Colorado, LASP, Boulder, CO 80309 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Burkholder, JB (reprint author), NOAA, 325 Broadway, Boulder, CO 80303 USA. RI Burkholder, James/H-4914-2013; McKeen, Stuart/H-9516-2013; Mills, Michael/B-5068-2010 OI Mills, Michael/0000-0002-8054-1346 NR 20 TC 34 Z9 34 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2000 VL 27 IS 16 BP 2493 EP 2496 DI 10.1029/1999GL011271 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 344QZ UT WOS:000088771500036 ER PT J AU VanZandt, TE Clark, WL Gage, KS Williams, CR Ecklund, WL AF VanZandt, TE Clark, WL Gage, KS Williams, CR Ecklund, WL TI A dual-wavelength radar technique for measuring the turbulent energy dissipation rate epsilon SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We used the ratio of simultaneous observations of radar reflectivity by S- and UHF-band radars together with Hill's model of refractivity fluctuations due to turbulence to infer epsilon, the rate of viscous dissipation of turbulent kinetic energy per unit mass. Observations were made for 25 days from November 13 to December 7, 1995, at 11.4 degrees S, 130.4 degrees E (about 100 km northwest of Darwin, Australia) during the Maritime Continent Thunderstorm Experiment (MCTEX). The 500 m pulse length data covered the height range 872 to 3032 m MSL. The observed distribution of epsilon has a strong diurnal variation, with mean daytime and nighttime values of epsilon of the order of 10(-3) and 10(-5) m(2)s(-3), respectively. With the dual-wavelength technique most non-turbulent echoes (including particulate echoes) are identified and filtered out, since the ensemble of turbulent observations is identified by its conformity to Hill's model. The technique is self-calibrating, requiring only the relative calibration of the two radars using observations during rain, and does not require precise absolute calibration of either radar. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. RP VanZandt, TE (reprint author), NOAA, Aeron Lab, R-AL3,325 Broadway, Boulder, CO 80305 USA. RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 9 TC 6 Z9 6 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2000 VL 27 IS 16 BP 2537 EP 2540 DI 10.1029/2000GL011628 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 344QZ UT WOS:000088771500047 ER PT J AU Folkins, I Oltmans, SJ Thompson, AM AF Folkins, I Oltmans, SJ Thompson, AM TI Tropical convective outflow and near surface equivalent potential temperatures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC WATER-VAPOR; TROPOPAUSE; FOUNTAIN AB We use clear sky heating rates to show that convective outflow in the tropics decreases rapidly with height between the 350 K and 360 K potential temperature surfaces (or between roughly 13 and 15 km). There is also a rapid fall-off in the pseudoequivalent potential temperature probability distribution of near surface air parcels between 350 K and 360 K. This suggests that the vertical variation of convective outflow in the upper tropical troposphere is to a large degree determined by the distribution of sub cloud layer entropy. C1 Dalhousie Univ, Dept Oceanog, Atmospher Sci Program, Halifax, NS B3H 4J1, Canada. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Folkins, I (reprint author), Dalhousie Univ, Dept Oceanog, Atmospher Sci Program, Halifax, NS B3H 4J1, Canada. RI Thompson, Anne /C-3649-2014 OI Thompson, Anne /0000-0002-7829-0920 NR 14 TC 35 Z9 35 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2000 VL 27 IS 16 BP 2549 EP 2552 DI 10.1029/2000GL011524 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 344QZ UT WOS:000088771500050 ER PT J AU Berg, WK Anderson, DM Bates, JJ AF Berg, WK Anderson, DM Bates, JJ TI Satellite observations of a Pacific moisture surge associated with flooding in Las Vegas SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MARITIME TROPICAL AIR; UNITED-STATES; CALIFORNIA; MONSOON; GULF AB A severe storm struck Las Vegas, Nevada, on July 8, 1999 causing widespread flooding and leading to a loss of life. SSM/I and GOES satellite observations reveal that this event was associated with a moisture surge originating in the tropical eastern Pacific. An evaluation of SSM/I and GOES imagery from June through September 1999 indicates that several moisture surges occurred during the North American monsoon season, seldom reaching Las Vegas, but sometimes pushing tropical moisture as far north as Lake Tahoe. The ability to identify and track these surges offers possibilities for improved understanding of the conditions leading to devastating storm events in northwestern Mexico and the southwestern United States. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Berg, WK (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Campus Box 216, Boulder, CO 80309 USA. RI Bates, John/D-1012-2009 OI Bates, John/0000-0002-8124-0406 NR 8 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2000 VL 27 IS 16 BP 2553 EP 2556 DI 10.1029/2000GL011367 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 344QZ UT WOS:000088771500051 ER PT J AU Beal, LM Molinari, RL Chereskin, TE Robbins, PE AF Beal, LM Molinari, RL Chereskin, TE Robbins, PE TI Reversing bottom circulation in the Somali Basin SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ARABIAN SEA; DEEP-WATER; CURRENTS; FLOW AB Two sets of direct velocity measurements were taken, concurrent with hydrographic data, in the bottom waters of the northern Somali Basin in June and September, 1995. The velocities indicate a temporal flow reversal in the bottom circulation, which is consistent with the changing density structure between the sections. In June, there is evidence of a southward Deep Western Boundary Current with a transport of 5 Sv. By September, flow close to the boundary is northward, with a transport of 2.6 Sv. Furthermore, the deep density gradient across the interior of the Somali Basin also changes between occupations, implying a cyclonic circulation in June and anticyclonic flow in September. Rossby wave activity is high in this region during the southwest monsoon, yet there is also evidence of a strong barotropic component to the Great Whirl in September, which may cause the reversal in the abyssal circulation. C1 Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Beal, LM (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA. OI Beal, Lisa/0000-0003-3678-5367 NR 12 TC 12 Z9 12 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2000 VL 27 IS 16 BP 2565 EP 2568 DI 10.1029/1999GL011316 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 344QZ UT WOS:000088771500054 ER PT J AU Kelly, PS Lwiza, KMM Cowen, RK Goni, GJ AF Kelly, PS Lwiza, KMM Cowen, RK Goni, GJ TI Low-salinity pools at Barbados, West Indies: Their origin, frequency, and variability SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTH BRAZIL CURRENT; CURRENT RETROFLECTION; WATER; CIRCULATION; ALTIMETRY; DYNAMICS; ESTUARY; RA-228 AB A vertical array of conductivity-temperature recorders moored off the west coast of Barbados, West Indies, from May 1996 to November 1997 revealed a heterogeneous and variable salinity pattern punctuated by five pools of low-salinity water (<34.5 practical salinity units (psu)) entering the region. A typical pool extended to 30-m depth and lasted similar to 25 days, although one pool extended to 47 m and lasted 94 days. Water samples taken from a pool in May 1997 have radium 228/226 activity ratios of similar to 1, consistent with previous measurements in Barbados of water that originated in the Amazon River mixing zone. The Amazon water likely was translated to Barbados in rings spawned from the North Brazil Current, Analysis of sea height anomaly and residual derived from the TOPEX/Poseidon satellite supports this conclusion and reveals that, contrary to previous studies, rings are shed throughout the year, mostly during spring. The pools of low-salinity water and their associated velocities dramatically changed the already variable flow in our study area. We believe the complex salinity and flow we observed represented the disorganized remnants of North Brazil Current rings that were at or near the ends of their lives. The changes we observed in the velocity and water structure are interesting in their own right as evidence of the Barbados region as a mixing zone and fur their influence on recruitment of larval fishes to the reef along the island's west coast. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Kelly, PS (reprint author), SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. RI Goni, Gustavo/D-2017-2012 OI Goni, Gustavo/0000-0001-7093-3170 NR 19 TC 22 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 2000 VL 105 IS C8 BP 19699 EP 19708 DI 10.1029/1999JC900328 PG 10 WC Oceanography SC Oceanography GA 344FJ UT WOS:000088748300014 ER PT J AU Wickliffe, ME Lawler, JE Nave, G AF Wickliffe, ME Lawler, JE Nave, G TI Atomic transition probabilities for DyI and DyII SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID ARGON BRANCHING RATIOS; OSCILLATOR-STRENGTHS; LIFETIME MEASUREMENTS; SOLAR SPECTRUM; DYSPROSIUM; SPECTROMETER; CALIBRATION AB Atomic transition probabilities for 915 spectral lines of neutral and singly ionized dysprosium are reported. Typical uncertainties are less than or equal to +/-10%. Branching fractions, measured using the 1.0 m Fourier transform spectrometer (FTS) at the National Solar Observatory and the 2.0 m FTS at the National Institute of Standards and Technology (NIST), are combined with recently published radiative lifetimes, measured using time-resolved laser-induced fluorescence on a slow atomic/ionic be;lm, to determine these transition probabilities. Reference sets of Ar I and ArII branching ratios are used in most of the work reported here to establish a radiometric calibration for the Fourier transform spectral from the National Solar Observatory. A subset of the lines are also measured using the NIST FTS. Most importantly, an independent radiometric calibration based on standard lamps is used with the NIST FTS. The generally good agreement between these independent measurements provides additional confidence in the radiometric calibration and the accuracy of the measurements. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Lawler, JE (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 28 TC 94 Z9 94 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD AUG 15 PY 2000 VL 66 IS 4 BP 363 EP 404 DI 10.1016/S0022-4073(99)00173-9 PG 42 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 315AZ UT WOS:000087091600004 ER PT J AU Thomson, R Levine, LE Stauffer, D AF Thomson, R Levine, LE Stauffer, D TI Theory of strain percolation in metals: mean field and strong boundary universality class SO PHYSICA A LA English DT Article DE dislocation percolation; metal deformation ID DISLOCATION AB For the percolation model of strain in a deforming metal proposed earlier, we develop sum rule and mean field approximations which predict a critical point. The numerical work is restricted to the simpler of two cases proposed in the earlier work, in which the cell walls are "strong", and unzipping of the dislocation entities which lock the walls into the lattice is not permitted. For this case, we find that strain percolation is a new form of correlated percolation, but that it is in the same universality class as standard percolation. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Cologne, Inst Theoret Phys, D-50923 Cologne, Germany. RP Levine, LE (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 22 TC 16 Z9 16 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD AUG 15 PY 2000 VL 283 IS 3-4 BP 307 EP 327 DI 10.1016/S0378-4371(00)00097-2 PG 21 WC Physics, Multidisciplinary SC Physics GA 338QN UT WOS:000088430900001 ER PT J AU Benz, SP Burroughs, CJ Dresselhaus, PD AF Benz, SP Burroughs, CJ Dresselhaus, PD TI Low harmonic distortion in a Josephson arbitrary waveform synthesizer SO APPLIED PHYSICS LETTERS LA English DT Article ID BIPOLAR VOLTAGE-SOURCE; AC AB The use of broadband integrated filters has enabled practical operating margins for ac waveforms synthesized from the perfectly quantized voltage pulses of Josephson junction arrays. This improvement enabled the digital synthesis of arbitrary waveforms with low harmonic distortion; the second and higher harmonics are all at least 94 dB below the fundamental [-94 dBc (carrier)]. This is a 47 dB lower distortion compared to that of the same sine wave synthesized by the semiconductor-based code generator which drives the array. We present operating margins for synthesized dc voltages and demonstrate synthesized waveforms with multiple tones at kilohertz and megahertz frequencies with harmonic distortion and intermodulation products below -80 dBc. [S0003-6951(00)00133-9]. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Benz, SP (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 33 Z9 33 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 14 PY 2000 VL 77 IS 7 BP 1014 EP 1016 DI 10.1063/1.1288597 PG 3 WC Physics, Applied SC Physics GA 344YE UT WOS:000088788000032 ER PT J AU Bu, ZM Neumann, DA Lee, SH Brown, CM Engelman, DM Han, CC AF Bu, ZM Neumann, DA Lee, SH Brown, CM Engelman, DM Han, CC TI A view of dynamics changes in the molten globule-native folding step by quasielastic neutron scattering SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE protein dynamics; protein folding dynamics; molten globule; quasielastic neutron scattering; alpha-lactalbumin ID BOVINE ALPHA-LACTALBUMIN; PROTEIN-STRUCTURE; TERTIARY FOLD; GUINEA-PIG; STATE; ENERGETICS; DIFFUSION; MOTIONS; ENTROPY; SIMULATIONS AB In order to understand the changes in protein dynamics that occur in the final stages of protein folding, we have used neutron scattering to probe the differences between a protein in its folded state and the molten globule states. The internal dynamics of bovine alpha-lactalbumin (BLA) and its molten globules (MBLA) have been examined using incoherent, quasielastic neutron scattering (IQNS). The IQNS results show length scale dependent, pico-second dynamics changes on length scales from 3.3 to 60 Angstrom studied. On shorter-length scales, the non-exchangeable protons undergo jump motions over potential barriers, as those involved in sidechain rotamer changes. The mean potential barrier to local jump motions is higher in BLA than in MBLA, as might be expected. On longer length scales, the protons undergo spatially restricted diffusive motions with the diffusive motions being more restricted in BLA than in MBLA. Both BLA and MBLA have similar mean square amplitudes of high frequency motions comparable to the chemical bond vibrational motions. Bond vibrational motions thus do not change significantly upon folding. Interestingly, the quasielastic scattering intensities show pronounced maxima for both BLA and MBLA, suggesting that "clusters" of atoms are moving collectively within the proteins on picosecond time scales. The correlation length, or "the cluster size", of such atom clusters moving collectively is dramatically reduced in the molten globules with the correlation length being 6.9 Angstrom in MBLA shorter than that of 18 Angstrom in BLA. Such collective motions may be important for the stability of the folded state, and may influence the protein folding pathways from the molten globules. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. RP Bu, ZM (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Brown, Craig/B-5430-2009 OI Brown, Craig/0000-0002-9637-9355 FU NIGMS NIH HHS [GM 22778] NR 56 TC 45 Z9 46 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD AUG 11 PY 2000 VL 301 IS 2 BP 525 EP 536 DI 10.1006/jmbi.2000.3978 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 345TK UT WOS:000088831100021 PM 10926525 ER PT J AU Alpert, B Greengard, L Hagstrom, T AF Alpert, B Greengard, L Hagstrom, T TI An integral evolution formula for the wave equation SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE small-cell problem; stability AB We present a new time-symmetric evolution formula for the scalar wave equation. It is simply related to the classical D'Alembert or spherical means representations, but applies equally well in two space dimensions. It can be used to develop stable, robust numerical schemes on irregular meshes. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. NYU, Courant Inst Math Sci, New York, NY 10012 USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM 87131 USA. RP Alpert, B (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 5 TC 16 Z9 16 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD AUG 10 PY 2000 VL 162 IS 2 BP 536 EP 543 DI 10.1006/jcph.2000.6547 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 343LL UT WOS:000088703800011 ER PT J AU Wullschleger, SD Wilson, KB Hanson, PJ AF Wullschleger, SD Wilson, KB Hanson, PJ TI Environmental control of whole-plant transpiration, canopy conductance and estimates of the decoupling coefficient for large red maple trees SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE energy balance; forest water use; sap velocity; stomatal control; thermal dissipation probes ID XYLEM SAP FLOW; BROAD-LEAVED FOREST; SURFACE CONDUCTANCE; STAND TRANSPIRATION; PINE FOREST; WATER-USE; FLUX; LEAF; EVAPORATION; DEPENDENCE AB There is a strong need to extend whole-tree measurements of sap flow into broad-leaved forests where characteristics of stand structure, surface roughness, leaf dimension, and aerodynamic and canopy conductance may interact to partially decouple the canopy from the atmosphere. The implications partial decoupling to understanding the environmental control of canopy transpiration and to the modeling of forest water use are many. Therefore, thermal dissipation probes were used over a three-month period (June through August, 1997) to quantify day-to-day and tree-to-tree variation in whole-tree sap Row (Q) for 12 red maple (Acer rubrum L.) trees growing in an upland oak forest of eastern Tennessee. Whole-tree Q was calculated as the product of measured sap velocity, sapwood area and the fraction of sapwood functional in water transport. Daily canopy transpiration (E-c) was calculated from whole-tree Q and projected crown area, whereas average daily conductance (g(c)) was derived by inverting the Penman-Monteith equation. Maximum Q averaged 73 kg per tree per day and varied between 45 and 160 kg per day for trees that ranged in stem diameter (DBH) from 17 to 35 cm, and from 19 to 26 m in height. Canopy transpiration peaked at 3.0 mm per day in early July and averaged 1.5 mm per day over the 3-month measurement period. Tree-to-toe variability for E-c was high. Maximum rates of E-c varied from 1.9 mm per day for the tree with the smallest projected crown area to 5.7 mm per day for one of the largest trees. Day-to-day variation in E-c was a function of daily differences in net radiation (R-n) and atmospheric humidity deficit (delta(e)). Increases in daily R-n and delta(e) led to linear increases in canopy transpiration and there was no indication that a plateau-style relationship existed between E-c and average daily delta(e). Mean daily g(c) ranged from 1.4 to 6.7 mm s(-1), and averaged 3.4 mm s(-1) across the 12 study trees. Some of the tree-to-tree variation observed for E-c and g(c) was related to the fact that not all trees occupied the same vertical position within the stand. Variation in estimates of the daily decoupling coefficient (0 less than or equal to Omega less than or equal to 1) was also considerable and for individual trees the seasonally-averaged Omega varied from 0.12 to 0.37, and averaged 0.23 for the 12 study trees. An Omega of this magnitude indicates that red maple canopies are partially decoupled from the atmosphere and suggests that significant vertical gradients of air temperature and delta(e) from the canopy surface to the bulk air several meters above the canopy are possible. Model analysis of hourly data indicated that simulated surface temperatures in mid-July were 3.6-5.8 degrees C higher than above-canopy reference temperatures, and delta(e) at the canopy surface was 0.3 kPa higher than that of the bulk atmosphere. These calculations were partially supported by leaf-level measurements taken on one of the trees from a 20-m canopy-access tower. The implications of this partial decoupling to understanding and modeling the environmental control of canopy transpiration are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NOAA, Air Res Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP Wullschleger, SD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Hanson, Paul J./D-8069-2011; Wullschleger, Stan/B-8297-2012 OI Hanson, Paul J./0000-0001-7293-3561; Wullschleger, Stan/0000-0002-9869-0446 NR 36 TC 69 Z9 90 U1 2 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD AUG 8 PY 2000 VL 104 IS 2 BP 157 EP 168 DI 10.1016/S0168-1923(00)00152-0 PG 12 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 339XL UT WOS:000088503100006 ER PT J AU Walker, ARH Fraser, GT Suenram, RD Lovas, FJ AF Walker, ARH Fraser, GT Suenram, RD Lovas, FJ TI The structure of O-3-CH4 and the implications for the O+CH4 precursor-initiated reaction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PULSED-MOLECULAR-BEAM; GAS-PHASE; COMPLEXES; WATER; DYNAMICS; DIMER; OZONE; CH4; SPECTROMETER; ROTATION AB The rotational spectrum of the O-3-CH4 complex has been measured in a molecular beam using a pulsed-nozzle Fourier-transform microwave spectrometer. An a-type pure-rotation and a c-type rotation-inversion electric-dipole spectrum is observed, complicated by the nearly free internal rotation of the CH4 top and the inversion tunneling of the O-3. The nuclear-spin statistics of the equivalent oxygen nuclei leads to only one tunneling component existing for each rotation-internal-rotation state, indicating that the transition state has a heavy-atom, C-2v-symmetry geometry. The tunneling splitting is determined to be 30 to 40 MHz, dependent on the CH4 internal-rotor state. Only two of the three methane internal-rotor states have been assigned. These two states of A and F symmetry have asymmetric-rotor energy-level structures, weakly perturbed by the ozone-inversion tunneling. The zero-point structure of the complex has a heavy-atom plane of symmetry with the two terminal O atoms equidistant above and below this plane. The angle between the line joining the center of masses of the two subunits and the O-3, C-2 axis is 118.2(5)degrees, with the central O directed away from the CH4. The shortest O-C separation is 3.57 Angstrom. The geometry of the complex suggests two outcomes for the reaction of an O atom produced by 267 nm photolysis of O-3 in the complex (assuming that the initial O-3 photodissociation dynamics are not perturbed by complexation), either nonreaction or reaction by stripping of a hydrogen atom at high impact parameters, leading to fast, highly rotationally excited, OH product. [S0021-9606(00)00430-X]. C1 NIST, Opt Tech Div, Gaithersburg, MD 20899 USA. RP NIST, Opt Tech Div, Gaithersburg, MD 20899 USA. RI Hight Walker, Angela/C-3373-2009 OI Hight Walker, Angela/0000-0003-1385-0672 NR 29 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 2000 VL 113 IS 6 BP 2139 EP 2144 AR PII [S0021-9606(00)00430-X] DI 10.1063/1.482026 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 344XT UT WOS:000088786900013 ER PT J AU Vanderah, DJ Pham, CP Springer, SK Silin, V Meuse, CW AF Vanderah, DJ Pham, CP Springer, SK Silin, V Meuse, CW TI Characterization of a series of self-assembled monolayers of alkylated 1-thiaoligo (ethylene oxides)(4-8) on Gold SO LANGMUIR LA English DT Article ID HYBRID BILAYER-MEMBRANES; SILVER SURFACES; LIPID BILAYERS; ADSORPTION; OXIDE); ATTACHMENT; MOLECULES; GLYCOL) AB Self-assembled monolayers of a series of linear thiols containing a 1-thiaoligo(ethylene oxide) (TOEO) moiety, i.e., HS(EO)(x)R (where R = C10H21, EO = -CH2CH2O-, and x = 4-8), were prepared on polycrystalline gold and characterized by visible spectroscopic ellipsometry (SE), infrared spectroscopic ellipsometry, and surface plasmon resonance. The TOEO segment was found to adopt a 7/2 helical structure oriented normal to the substrate for x = 5-7. Different structures were found for the other compounds in this series. When x = 4, the TOEO segment adopts a predominantly trans-extended conformation, whereas when x = 8, the TOEO appears to be disordered with some helical conformation. Monolayer thicknesses determined by SE are consistent with these structural changes. The significant increase in disorder with extension of the hydrophilic segment by two ethylene oxide units from 6 to 8 is potentially valuable for protein reconstitution in supported hybrid bilayer constructs. C1 Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Georgetown Univ, Washington, DC 20057 USA. RP Vanderah, DJ (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 29 TC 30 Z9 30 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG 8 PY 2000 VL 16 IS 16 BP 6527 EP 6532 DI 10.1021/la9916833 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 341MG UT WOS:000088593700025 ER PT J AU Meredith, JC Karim, A Amis, EJ AF Meredith, JC Karim, A Amis, EJ TI High-throughput measurement of polymer blend phase behavior SO MACROMOLECULES LA English DT Article ID COMBINATORIAL LIBRARY; DISCOVERY C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Meredith, JC (reprint author), Georgia Inst Technol, Sch Chem Engn, Atlanta, GA 30332 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 14 TC 140 Z9 142 U1 4 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 5760 EP 5762 DI 10.1021/ma0004662 PG 3 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700004 ER PT J AU Grohn, F Bauer, BJ Akpalu, YA Jackson, CL Amis, EJ AF Grohn, F Bauer, BJ Akpalu, YA Jackson, CL Amis, EJ TI Dendrimer templates for the formation of gold nanoclusters SO MACROMOLECULES LA English DT Article ID SMALL-ANGLE SCATTERING; HYDROPHILIC BLOCK-COPOLYMERS; STARBURST DENDRIMERS; EPR TECHNIQUE; COLLOIDS; NANOCOMPOSITES; NANOPARTICLES; CATALYSIS; TRANSFORMATION; PHOSPHATE AB Charged poly(amidoamine) (PAMAM) dendrimers are used to create organic-inorganic hybrid colloids in aqueous solution. The formation of gold colloids upon reduction of a gold salt precursor serves as a model reaction to study the influence of reaction conditions and dendrimer generation on the resulting nanostructures. Characterization by transmission electron microscopy (TEM), small-angle neutron scattering (SANS), and small-angle X-ray scattering (SAXS) show that the gold particles are formed inside the dendrimer and located offset from the center. Although lower generation dendrimers aggregate when stabilizing the metal particles formed, dendrimers of generation 6-9 can template one gold colloid per dendrimer molecule, the size of which is well-controlled by the number of gold atoms added per dendrimer. For generation 10, multiple smaller gold particles per dendrimer are observed. The effectiveness of PAMAM dendrimers as templates in the host-guest nanoscale synthesis is confirmed for different chemical reactions. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Amis, EJ (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. OI Jackson, Catheryn/0000-0003-1611-3926 NR 34 TC 304 Z9 310 U1 9 U2 92 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6042 EP 6050 DI 10.1021/ma000149v PG 9 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700045 ER PT J AU Genzer, J Sivaniah, E Kramer, EJ Wang, JG Xiang, ML Char, K Ober, CK Bubeck, RA Fischer, DA Graupe, M Colorado, R Shmakova, OE Lee, TR AF Genzer, J Sivaniah, E Kramer, EJ Wang, JG Xiang, ML Char, K Ober, CK Bubeck, RA Fischer, DA Graupe, M Colorado, R Shmakova, OE Lee, TR TI Molecular orientation of single and two-armed monodendron semifluorinated chains on "soft" and "hard" surfaces studied using NEXAFS SO MACROMOLECULES LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; BLOCK-COPOLYMERS; ALKANETHIOLATE MONOLAYERS; SIDE-CHAINS; THIN-FILMS; X-RAY; SPECTROSCOPY; POLYMERS AB Near-edge absorption fine structure (NEXAFS) measurements are used to probe the molecular orientation of semifluorinated (SF) mesogens, -(CH2)(x)(CF2)(y)F, which are attached to (i) the isoprene backbone of polyisoprene or a styrene-isoprene diblock copolymer ("soft" substrate), and (ii) a Au-covered solid substrate via a thiol link ("hard" substrate). The SF groups on both surfaces are oriented and on average are tilted from the sample normal. The tilt angle, [tau(F)-helix], of the fluorinated part of the SF group on each substrate is determined exclusively by the combination of x and y, increasing with increasing x and with decreasing y. Moreover, [tau(F)-helix] is found to be independent of the surface topology (flat surfaces vs surfaces covered with holes or islands of the copolymer), casting solvent, and the architecture of the SF group (single vs 2-armed monodendron). Comparing the orientation of the SF groups on both substrates reveals that [tau(F)-helix] is approximately 14 degrees higher on the "soft" substrate. C1 N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. Michigan Mol Inst, Midland, MI 48640 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. RP Genzer, J (reprint author), N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. OI Lee, T. Randall/0000-0001-9584-8861 NR 34 TC 49 Z9 51 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6068 EP 6077 DI 10.1021/ma991710w PG 10 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700048 ER PT J AU VanderHart, DL Alamo, RG Nyden, MR Kim, MH Mandelkern, L AF VanderHart, DL Alamo, RG Nyden, MR Kim, MH Mandelkern, L TI Observation-of resonances associated with stereo and regio defects in the crystalline regions of isotactic polypropylene: Toward a determination of morphological partitioning SO MACROMOLECULES LA English DT Article ID ZIEGLER-NATTA CATALYSTS; C-13 NMR-SPECTRA; POLYMER; CHAINS; FRACTIONATION; PROPENE; PHASE AB We report defect-resonance patterns associated with two kinds of low-concentration defects typically found in metallocene-synthesized isotactic polypropylenes (iPP's). These defects are the simple mrrm stereo defect and the regio 2,1-erythro defect. This work is a critical part of our effort to determine the extent to which various defects, typically found in isotactic polypropylene (iPP) samples, are incorporated into the crystalline regions of this semicrystalline polymer. The relationship between defect concentrations and mechanical (as well as thermal) properties is quite dependent on the extent of incorporation of defects into the crystalline regions. Several melt-crystallized (at a cooling rate of 1 degrees C/min) iPP samples, whose concentrations of various stereo and regio defects are known from high-resolution NMR, have been examined in the solid state by C-13 NMR. Using a method based on differences in the rotating-frame proton relaxation times of the crystalline (CR) and the noncrystalline (NC) regions, signals from the CR and the NC regions are separated. The resulting "CR" spectra, pertaining to the CR regions of the iPP, are examined for distinct resonances associated with such defects; relative integrals associated with these resonances are also determined. Definite defect-resonance patterns associated with both the simple mrrm stereo defect and the regio 2,1-erythro defect have been identified. One of our samples, having a rather low molecular weight, contained a substantial amount of the regio 1,3 defect. The corresponding CR spectrum had no sharper resonances that would indicate the presence of 1,3 defects in the CR lattice. Associated with each type of defect, "i", we define a partitioning coefficient, P-CR(i), as the ratio of the ith-defect concentration in the CR region to the overall ith-defect concentration. While we cannot, at this point, be absolutely sure about assignments which ultimately dictate the crucial correspondence between defect populations and defect intensities, we can make arguments or assumptions about this correspondence and then suggest P-CR values for the stereo and regio defects. On the basis of the arguments and assumptions made herein, the following values are obtained: P-CR(stereo: mrrm) = 0.48 +/- 0.06 and P-CR(regio: 2,1-erythro) = 0.28 +/- 0.08. In principle, partitioning coefficients might depend on both on the crystallization kinetics and the crystal habit. Many of our samples possessed mixed amounts of alpha- and gamma-crystallites. The few indications we have suggest that there is only a weak dependence, if any, on kinetics or crystal habit. The hypothesis is considered that those defects seen in the CR spectrum are highly concentrated at the CR/NC interface. On the basis of a modeling of the experimental proton polarization, including spin diffusion, it is concluded that the defects are not highly concentrated on the CR side of the interface; at the same time, we have no information about the possibility of defect concentration on the NC side of the interface; Finally, one of our samples was an iPP pseudofraction derived from an inhomogeneous Ziegler-Natta polymerization. P-CR(stereo) for this sample was lower than for the metallocene iPP's, including one with a similar overall defect concentration. Our results support the notion hat the Ziegler-Natta pseudofraction consists of a much more inhomogeneous distribution of defect concentrations per chain than that which typifies metallocene iPP's. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Florida State Univ, Florida Agr Mech Univ, Dept Chem Engn, Tallahassee, FL 32310 USA. Florida State Univ, Dept Chem, Tallahassee, FL 32306 USA. RP VanderHart, DL (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 44 TC 67 Z9 67 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6078 EP 6093 DI 10.1021/ma992041p PG 16 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700049 ER PT J AU Alamo, RG VanderHart, DL Nyden, MR Mandelkern, L AF Alamo, RG VanderHart, DL Nyden, MR Mandelkern, L TI Morphological partitioning of ethylene defects in random propylene-ethylene copolymers SO MACROMOLECULES LA English DT Article; Proceedings Paper CT ACS 99 Meeting CY AUG 22-26, 1999 CL NEW ORLANDS, LOUISIANA SP ACS ID NUCLEAR-MAGNETIC-RESONANCE; ZIEGLER-NATTA CATALYSTS; GAMMA-ISOTACTIC POLYPROPYLENE; C-13 NMR DETERMINATION; CRYSTALLIZATION BEHAVIOR; PROPENE; FRACTIONS; POLYMERIZATION; SPECTROSCOPY; POLYETHYLENE AB A series of four propylene/ethylene, metallocene-catalyzed random copolymer samples, with ethylene mole fractions ranging from 0.8% to 7.5% and melt crystallization histories of cooling at 1 degrees C/min, were studied by C-13 solid-state NMR techniques. The principal objective of the study was to determine the partitioning of the ethylene "defect" residues within the semicrystalline morphology of these isotactic poly(propylene/ethylene) copolymers: Signals from the crystalline (CR) and the noncrystalline (NC) regions were separated on the basis of contrasting T-1 rho(H) behaviors. Four new resonances, three distinct and one strongly overlapping, were identified in the spectrum of the CR regions. The assignment of these new defect resonances to specific carbons at or near the ethylene defect site was made principally on the basis of quantum mechanical chemical shift calculations. These calculations were performed on two methyl-terminated oligomers of about 6.5 monomers in length with a 3(1) helical backbone conformation, characteristic of the iPP backbone conformation in the CR state. One oligomer was the pure iPP chain, and the other contained one centrally located ethylene repeat unit. Good agreement between the experimental shifts associated with the ethylene defect and the computed shifts supported the assumption that the chain conformation in the CR regions in the vicinity of the ethylene defect remained a 3(1) helix. This good agreement between shifts was obtained when the computed shifts were not used directly, but used in a difference mode. This mode was based on the computed shift differences for corresponding carbons on the two oligomers where these differences were applied to the experimental shifts of the main iPP peaks with the same chemical identity. The assignment of the defect resonances, along with the loss of chemical shift equivalences seen in solution-state spectra, was also rationalized in the context of gamma-gauche and vicinal-gauche. interactions as applied to the 3(1) helical structure. Defect line width differences that parallel the line width differences of the main iPP resonances also aid in assigning the defect resonances to particular types of carbons. Over the range of ethylene concentrations studied herein, the partitioning coefficient, P-CR(eth), given by the ratio of the concentration of ethylene residues in the CR region to the sample-average concentration of ethylene residues, is found to be constant, taking a value of 0.42 with a standard uncertainty of 0.03. On the basis of measurements of the NMR crystallinities, this partitioning translates to a fraction of the total ethylene residues in CR regions ranging from 0.24 to 0.30 and an average concentration of ethylenes in the NC region about twice the overall concentration. We also looked for evidence that the ethylene residues become highly concentrated at the CR/NC interface. While we cannot say whether this is happening on the NC side of the interface, since we cannot identify any NC defect resonances, we can claim that a high concentration of ethylene residues is not found on the CR side near the interface. C1 Florida State Univ, Florida Agr & Mech Univ, Dept Chem Engn, Tallahassee, FL 32310 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Florida State Univ, Dept Chem, Tallahassee, FL 32306 USA. RP Alamo, RG (reprint author), Florida State Univ, Florida Agr & Mech Univ, Dept Chem Engn, 2525 Pottsdamer St, Tallahassee, FL 32310 USA. NR 48 TC 76 Z9 78 U1 2 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6094 EP 6105 DI 10.1021/ma000267i PG 12 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700050 ER PT J AU Xiang, ML Li, XF Ober, CK Char, K Genzer, J Sivaniah, E Kramer, EJ Fischer, DA AF Xiang, ML Li, XF Ober, CK Char, K Genzer, J Sivaniah, E Kramer, EJ Fischer, DA TI Surface stability in liquid-crystalline block copolymers with semifluorinated monodendron side groups SO MACROMOLECULES LA English DT Article ID DENDRITIC DIBLOCK COPOLYMERS; LOW-ENERGY SURFACES; FLUORINATED POLYSILOXANES; ESTER FUNCTION; SOLID-STATE; POLYMERS; MACROMOLECULES; MONOLAYERS; DENDRIMERS; BEHAVIOR AB Block copolymers with semifluorinated monodendron side groups were synthesized by attachment of a first generation 2- or 3-armed monodendron acid chloride to a hydroxylated poly(styrene-b-1,2/3,4-isoprene). A convergent growth strategy was developed to synthesize the monodendron groups in good yield using an approach that could be extended to higher generation monodendrons. High extents of attachment were achieved despite the steric effects of the bulky monodendron side groups. The resulting polymers formed a smectic B mesophase at room temperature as determined by WAXS data. The transition temperatures, mesophase range, and enthalpy of the smectic B-isotropic transition were all affected by side-group structural factors such as flexible spacer length, mesogen length, and monodendron core. The critical surface tensions of the resulting semifluorinated polymers were as low as similar to 8 mN/m as determined by Zisman analysis. Surface stability of polymer films in a polar liquid environment was strongly dependent on the extent of attachment exhibited by the semifluorinated groups. The monodendron -CF2-helix within 1 nm of the surfaces has a net orientation normal to the surface as measured by near-edge X-ray absorption fine structure (NEXAFS) methods, but the orientational order parameter S-helix is much higher for the 2-armed monodendrons than for the 3-armed monodendrons. In both cases S-helix seems insensitive to monodendron attachment density along the isoprene block. We suggest that packing frustration of the monodendron subunits produces surfaces with spontaneous curvature that differs depending on whether the monodendrons are 2- or 3-armed. The more highly curved surface topology of the 3-armed monodendrons may provide a partial explanation for its decreased orientational order. C1 Cornell Univ, Ithaca, NY 14853 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Ober, CK (reprint author), Cornell Univ, Bard Hall, Ithaca, NY 14853 USA. NR 43 TC 102 Z9 105 U1 2 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6106 EP 6119 DI 10.1021/ma992111s PG 14 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700051 ER PT J AU Yim, H Kent, M Matheson, A Ivkov, R Satija, S Majewski, J Smith, GS AF Yim, H Kent, M Matheson, A Ivkov, R Satija, S Majewski, J Smith, GS TI Adsorption of poly(styrenesulfonate) to the air surface of water by neutron reflectivity SO MACROMOLECULES LA English DT Article ID X-RAY REFLECTIVITY; POLY-ELECTROLYTE ADSORPTION; ADSORBED BETA-CASEIN; AIR/WATER INTERFACE; IONIC-STRENGTH; CONCENTRATION PROFILES; POLYSTYRENE SULFONATE; SOLVENT CONDITIONS; AQUEOUS-SOLUTIONS; DENSITY PROFILE AB The adsorption of the strong polyelectrolyte poly(styrenesulfonate) (PSS) to the air surface of dilute aqueous solutions was investigated as a function of molecular weight and salt concentration. Detailed segment profiles of the deuterated polymer were determined by neutron reflection. Surface activity was also examined through surface tension measurements. In general, the segment profiles are composed of a thin layer (10-20 Angstrom thick) of high concentration at the air surface, followed by a distinct second layer of much lower segment concentration that extends to larger depths into the liquid. The high segment density at the air surface is due to a strong surface attraction, arising from the low surface energy of the PSS backbone relative to the surface tension of water. At low salt concentration, the profiles tend toward a single dense layer, suggesting that the chains lie nearly flat at the interface in that limit. The adsorbed amount increases with salt concentration, with a stronger dependence for higher molecular weight chains. The adsorbed amounts at the air/water interface are higher than reported previously for PSS adsorbed onto neutral solid surfaces, consistent with the fact that the air-liquid interface provides a stronger surface attraction. While the trends of adsorbed amount with salt concentration and molecular weight are in good agreement with numerical self-consistent-field lattice calculations, the measured bilayer profiles are rather different from the smoothly decaying theoretical profiles. The surface tensions of the PSS solutions are significantly lowered relative to those of pure salt solutions. Combining the reflectivity and surface tension measurements, an approximately linear relationship is established between the surface pressure and the PSS adsorbed amount. C1 Sandia Natl Labs, Dept 1832, Albuquerque, NM 87185 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM USA. RP Kent, M (reprint author), Sandia Natl Labs, Dept 1832, POB 5800, Albuquerque, NM 87185 USA. RI Lujan Center, LANL/G-4896-2012; Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 54 TC 32 Z9 32 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 8 PY 2000 VL 33 IS 16 BP 6126 EP 6133 DI 10.1021/ma000266q PG 8 WC Polymer Science SC Polymer Science GA 343FU UT WOS:000088691700053 ER PT J AU Grinstead, JH Barker, PF AF Grinstead, JH Barker, PF TI Coherent Rayleigh scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID BRILLOUIN GAIN SPECTROSCOPY AB The spectrum of coherent scattering induced by electrostriction in gases has been analyzed in the previously unexplored, free-molecule limit by solving Boltzmann's equation with a periodic force due to the optical fields. Calculated and measured spectra of several gases at rarefied conditions are nearly Gaussian with widths approximately 10% wider than the spontaneous Rayleigh widths. Our results are the first spectrally resolved measurements of coherent Rayleigh scattering in the free-molecule limit, where the hydrodynamic analysis of stimulated Rayleigh-Brillouin scattering does not apply. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. RP Grinstead, JH (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Barker, Peter/A-4581-2011; OI Barker, Peter/0000-0001-9669-9853 NR 7 TC 45 Z9 45 U1 2 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 AUG 7 PY 2000 VL 85 IS 6 BP 1222 EP 1225 DI 10.1103/PhysRevLett.85.1222 PG 4 WC Physics, Multidisciplinary SC Physics GA 341VN UT WOS:000088611800021 ER PT J AU Wu, JF Sunda, W Boyle, EA Karl, DM AF Wu, JF Sunda, W Boyle, EA Karl, DM TI Phosphate depletion in the western North Atlantic Ocean SO SCIENCE LA English DT Article ID PACIFIC-OCEAN; NITROGEN-FIXATION; FERTILIZATION EXPERIMENT; DISSOLVED PHOSPHORUS; NUTRIENT; IRON; DENITRIFICATION; PHYTOPLANKTON; TRICHODESMIUM; RATIOS AB Surface waters of the subtropical Sargasso Sea contain dissolved inorganic phosphate (DIP) concentrations of 0.2 to 1.0 nanomolar, which are sufficiently Low to result in phosphorus control of primary production. The DIP concentrations in this area (which receives high inputs of iron-rich dust from arid regions of North Africa) are one to two orders of magnitude lower than surface Levels in the North Pacific (where eolian iron inputs are much Lower and water column denitrification is much more substantial). These data indicate a severe relative phosphorus depletion in the Atlantic. We hypothesize that nitrogen versus phosphorus Limitation of primary production in the present-day ocean may be closely linked to iron supply through control of dinitrogen (N(2)) fixation, an iron-intensive metabolic process. Although the oceanic phosphorus inventory may set the upper Limit for the total amount of organic matter produced in the ocean over geological time scales, at any instant in geological time, oceanic primary production may fall below this Limit because of a persistent insufficient iron supply. By controlling N(2) fixation, iron may control not only nitrogen versus phosphorus Limitation but also carbon fixation and export stoichiometry and hence biological sequestration of atmospheric carbon dioxide. C1 MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NOAA, Beaufort Lab, Beaufort, NC 28516 USA. Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. RP Wu, JF (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RI Wu, Jingfeng/B-1301-2012 NR 62 TC 442 Z9 466 U1 13 U2 109 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 4 PY 2000 VL 289 IS 5480 BP 759 EP 762 DI 10.1126/science.289.5480.759 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 341FZ UT WOS:000088581500035 PM 10926534 ER PT J AU Bhobe, AU Holloway, CL Piket-May, M Hall, R AF Bhobe, AU Holloway, CL Piket-May, M Hall, R TI Coplanar waveguide fed wideband slot antenna SO ELECTRONICS LETTERS LA English DT Article AB A new design for a coplanar waveguide (CPW) fed slot antenna is presented. The impedance matching and the radiation characteristics of this structure were studied using the method of moment technique. This antenna has an impedance bandwidth (for a VSWR < 2) of 49% and a radiation bandwidth of 42% about its 4.8GHz centre frequency, compared to the 12-20% impedance bandwidth of the standard CPW fed slot antenna. The cross-polarisation in both the principle planes is at least 20dB below co-polarisation across the entire bandwidth. Simulated and measured results of the antenna are presented. This wideband antenna has significant applications in wireless technologies. C1 Univ Colorado, Dept Elect & Comp Engn, Boulder, CO 80309 USA. Natl Inst Stand & Technol, US Dept Commerce, Boulder Labs, Boulder, CO 80303 USA. Ansoft Corp, Boulder, CO 80303 USA. RP Bhobe, AU (reprint author), Univ Colorado, Dept Elect & Comp Engn, Boulder, CO 80309 USA. NR 7 TC 42 Z9 43 U1 0 U2 4 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD AUG 3 PY 2000 VL 36 IS 16 BP 1340 EP 1342 DI 10.1049/el:20000984 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 344MJ UT WOS:000088762800005 ER PT J AU Brown, SS Ravishankara, AR Stark, H AF Brown, SS Ravishankara, AR Stark, H TI Simultaneous kinetics and ring-down: Rate coefficients from single cavity loss temporal profiles SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ABSORPTION-SPECTROSCOPY; RADICAL REACTIONS; N2O5 PHOTOLYSIS; QUANTUM YIELDS; RATE CONSTANTS; SELF-REACTION; 330 NM; NO3; SPECTRUM; C6H5 AB Cavity ring-down spectroscopy is a recently developed technique for highly sensitive detection of atomic and molecular absorptions. Here, we demonstrate the application of this technique to the measurement of kinetics that occur on the same time scale as the loss of light intensity from an optical cavity. We report rate constants for the reactions NO + NO3 --> 2NO(2) and OH + HNO3 --> H2O + NO3 at 296 K, measured as a test of this method. Observed ring-down profiles with a changing absorber concentration match calculated profiles, and fits to these profiles produce rate constants that agree with literature values to within the uncertainty of the measurements. The technique is general and should provide a simple means of measuring kinetic parameters for fast reactions. We also note the possible uses of this method for a variety of kinetics experiments and the outlook for future improvements. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Ravishankara, AR (reprint author), NOAA, Aeron Lab, R-AL2,325 Broadway, Boulder, CO 80303 USA. RI Stark, Harald/E-7433-2010; Brown, Steven/I-1762-2013; Ravishankara, Akkihebbal/A-2914-2011 NR 36 TC 52 Z9 53 U1 1 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 3 PY 2000 VL 104 IS 30 BP 7044 EP 7052 DI 10.1021/jp0013715 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 340FN UT WOS:000088522600020 ER PT J AU Roitberg, AE Worthington, SE Holden, MJ Mayhew, MP Krauss, M AF Roitberg, AE Worthington, SE Holden, MJ Mayhew, MP Krauss, M TI The electronic spectrum of the prephenate dianion. An experimental and theoretical (MD/QM) comparison SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MONOFUNCTIONAL CHORISMATE MUTASE; BACILLUS-SUBTILIS; TRANSITION-STATE; MECHANISM; REARRANGEMENT; PURIFICATION; SOLVATION; CATALYSIS; CHARGES; ENZYME AB Prephenate is the product of a Claisen rearrangement of chorismate. The enzyme chorismate mutase (CM from B. subtilis) accelerates the reaction by a factor of 10(6). The standard method for quantifying prephenate measures the electronic absorption spectrum after acid conversion to phenylpyruvate and subsequent alkaline treatment. To the best of our knowledge, there is no reported UV/Vis spectrum for pure prephenate. The present experimental measurement thus solves this lack of data. A novel molecular dynamics/quantum mechanics method was used to theoretically compute the electronic spectrum, and was used as supporting analysis for the new experimental spectrum. The agreement between theory and experiment is excellent in the position of the absorption peaks, their relative intensities, and their widths. A number of prephenate conformers are possible in aqueous solution, with the active conformer of CM binding just one conformer which is analogous to the dominant conformer in solution. The conformers are studied in vacuo and in the enzyme active site by ab Initio quantum chemical calculations, and in solution with a classical molecular dynamics simulation. The data presented here also suggest that the electronic spectrum of prephenate bound to the chorismate mutase active site should be observed, even in the presence of other members of the aromatic amino acid pathway. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Roitberg, AE (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr,Stop 8312, Gaithersburg, MD 20899 USA. RI Roitberg, Adrian/A-2378-2009 NR 25 TC 24 Z9 24 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 2 PY 2000 VL 122 IS 30 BP 7312 EP 7316 DI 10.1021/ja9945358 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 342RF UT WOS:000088658400019 ER PT J AU Robinson, KA Ladner, JE Tordova, M Gilliland, GL AF Robinson, KA Ladner, JE Tordova, M Gilliland, GL TI Cryosalts: suppression of ice formation in macromolecular crystallography SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID DIFFRACTION; CRYOCRYSTALLOGRAPHY; TEMPERATURE; MOSAICITY; CRYSTALS AB Quality data collection for macromolecular cryocrystallography requires suppressing the formation of crystalline or microcrystalline ice that may result from flash-freezing crystals. Described here is the use of lithium formate, lithium chloride and other highly soluble salts for forming ice-ring-free aqueous glasses upon cooling from ambient temperature to 100 K. These cryosalts are a new class of cryoprotectants that are shown to be effective with a variety of commonly used crystallization solutions and with proteins crystallized under different conditions. The influence of cryosalts on crystal mosaicity and diffraction resolution is comparable with or superior to traditional organic cryoprotectants. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Maryland Biotechnol Inst, Rockville, MD 20850 USA. Five Oaks Res Inst, Cincinnati, OH 45238 USA. RP Gilliland, GL (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. EM gary.gilliland@nist.gov NR 21 TC 2 Z9 2 U1 0 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0907-4449 EI 1399-0047 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD AUG PY 2000 VL 56 BP 996 EP 1001 PN 8 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 337WD UT WOS:000088384200008 ER PT J AU Cahn, JW Novick-Cohen, A AF Cahn, JW Novick-Cohen, A TI Motion by curvature and impurity drag: Resolution of a mobility paradox SO ACTA MATERIALIA LA English DT Article DE phase transformations; theory & modeling; kinetics; surfaces; ordering; critical phenomena ID CAHN-HILLIARD EQUATION; MIGRATING DIFFUSE INTERFACES; PHASE-SEPARATION; BOUNDARY MOTION; ORDER-DISORDER; SURFACE MOTION; ALLOYS; MODEL; TRANSFORMATIONS; PRECIPITATION AB We rederive and explain the paradoxical prediction, confirmed by experiment. that the normal velocity, V. of a curved antiphase domain boundary (APB) in an ordered alloy tends to a finite limit at a critical point, where the APB effectively disappears. its surface energy gamma tending to 0, and its thickness lambda diverging. The prediction is in apparent contradiction to the expectation that the velocity of the APE should tend to 0 based on the notion that V should be proportional to gamma and inversely proportional to lambda. Combining an Allen-Cahn equation for the rate of change of the order parameter, a non-conserved quantity, with a Cahn-Hilliard equation for the diffusion of one of the chemical components of an alloy, a conserved quantity, we obtain a system from which we derive an expression, via formal asymptotics, for V of an APE domain boundary in an ordered alloy. The drags from the two types of quantities are Found to be additive. We find that the drag from the changes in ordering accompanying the motion of the APE decreases inversely as the thickness. Thus, at the critical temperature where the thickness of an APE diverges and its gamma tends to 0, the drag tends to 0. This resolves the paradoxical behavior of APE at the critical point: they continue to move up to the limiting condition where they, and their driving force for motion, disappear. The drag from the conserved component, which moves with the boundary as an adsorbed layer, exerts a drag on the boundary that is similar to what is predicted for impurity drag. In general the drag is given by a compositional integral through the interface that is not simply related to either the thickness or the total adsorption. However, for thick compositional wetting layers the drag indeed varies with thickness. We believe that the distinction we have encountered in the behavior of composition and order parameter is quite general for motion of interfaces. unless strong cross-effects influence the evolution of the system. Our results yield a unification and reconciliation of several diverse theories of interface motion. (C) 2000 Published by Elsevier, Science Ltd on behalf of Acta Metallurgica Inc. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Technion Israel Inst Technol, Dept Math, IL-32000 Haifa, Israel. RP Cahn, JW (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 39 TC 13 Z9 13 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 1 PY 2000 VL 48 IS 13 BP 3425 EP 3440 DI 10.1016/S1359-6454(00)00144-0 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CL UT WOS:000089196900014 ER PT J AU Chopra, HD Repetski, EJ Brown, HJ Chen, PJ Swartzendruber, LJ Egelhoff, WF AF Chopra, HD Repetski, EJ Brown, HJ Chen, PJ Swartzendruber, LJ Egelhoff, WF TI Magnetic behavior of atomically engineered NiO-Co-Cu-based giant magnetoresistance spin valves using Pb as a surface modifier SO ACTA MATERIALIA LA English DT Article DE magnetoresistive effects; surfaces and interfaces; multilayers; magnetic structure; magnetic properties ID FCC-FE FILMS; FREE-ENERGIES; GROWTH; SUPERLATTICES; CU(100); METALS; AU; MULTILAYERS; ANISOTROPY AB The present study illustrates the efficacy of using surface modifiers, or simply surfactants, to alter, modify, or control the nature of interfaces and film morphology in order to control physical properties in magnetic multilayers. In particular, the magnetic properties of giant magnetoresistive NiO-Co-Cu-based symmetric spin valves are discussed in relation to the modification of interfaces and nanostructure using surface modifier Pb. Results show that a ML of Pb deposited on the first Co/Cu bilayer of the symmetric spin valve leads to reduced in-plane magnetic anisotropy and coupling. In the presence of Pb, the coherent growth mode of Co-Cu layers is disrupted, leading to a fine grain size (approximate to 1-5 nm) in the metal layers. Although this grain size corresponds to the critical wavelength for maximum coupling due to Neel's so-called "orange-peel" effect, the absence of topographical correlation between various interfaces prevent the occurrence of this form of coupling. At the same time, averaging of exchange interactions over such a fine grain size, which is much lower than the characteristic exchange length for Co (approximate to 25-45 nm), precludes the display of local magnetocrystalline easy axes, thereby leading to low switching fields. The nature of magnetization reversal in the "free" Co layer of the Pb-free spin valve is highly local in nature and occurs by nucleation, growth and coalescence together of irregular micron or sub-micron sized domains. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 SUNY Buffalo, Dept Mech & Aerosp Engn, Mat Program, Thin Films & Nanosynth Lab, Buffalo, NY 14260 USA. NIST, Gaithersburg, MD 20899 USA. RP Chopra, HD (reprint author), SUNY Buffalo, Dept Mech & Aerosp Engn, Mat Program, Thin Films & Nanosynth Lab, Buffalo, NY 14260 USA. NR 30 TC 17 Z9 21 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 1 PY 2000 VL 48 IS 13 BP 3501 EP 3508 DI 10.1016/S1359-6454(00)00146-4 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CL UT WOS:000089196900020 ER PT J AU Tully, LA Parsons, TJ Steighner, RJ Holland, MM Marino, MA Prenger, VL AF Tully, LA Parsons, TJ Steighner, RJ Holland, MM Marino, MA Prenger, VL TI A sensitive denaturing gradient-gel electrophoresis assay reveals a high frequency of heteroplasmy in hypervariable region 1 of the human mtDNA control region SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID HUMAN MITOCHONDRIAL-DNA; SINGLE-BASE CHANGES; SUBSTITUTION RATE VARIATION; POINT MUTATIONS; GC-CLAMP; HUMAN-EVOLUTION; D-LOOP; SEQUENCE; POLYMORPHISM; REPLICATION AB A population study of heteroplasmy in the hypervariable region 1 (HV1) portion of the human mtDNA control region was performed. Blood samples from 253 randomly chosen individuals were examined using a sensitive denaturing gradient-gel electrophoresis (DGGE) system, This method is capable of detecting heteroplasmic proportions as low as 1% and virtually all heteroplasmy where the minor component is greater than or equal to 5%. Heteroplasmy was observed in 35 individuals (13.8%; 95% confidence interval [CI] 9.6-18.0). Of these individuals, 33 were heteroplasmic at one nucleotide position, whereas 2 were heteroplasmic at two different positions (a condition known as "triplasmy"), Although heteroplasmy occurred at a total of 16 different positions throughout HV1, it was most frequently observed at positions 16093 (n = 13) and 16129 (n = 6), In addition, the majority of heteroplasmic variants occurred at low proportions and could not be detected by direct sequencing of PCR products. This study indicates that low-level heteroplasmy in HV1 is relatively common and that it occurs at a broad spectrum of sites. Our results corroborate those of other recent reports indicating that heteroplasmy in the control region is more common than was previously believed-a finding that is of potential importance to evolutionary studies and forensic applications that are based on mtDNA variation. C1 Univ Maryland, Sch Med, Div Human Genet, Baltimore, MD 21201 USA. Armed Forces Inst Pathol, Ctr Med & Mol Genet, Rockville, MD USA. Armed Forces Inst Pathol, Armed Forces DNA Identificat Lab, Rockville, MD USA. RP Tully, LA (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr,MS 8311, Gaithersburg, MD 20899 USA. NR 68 TC 87 Z9 94 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD AUG PY 2000 VL 67 IS 2 BP 432 EP 443 DI 10.1086/302996 PG 12 WC Genetics & Heredity SC Genetics & Heredity GA 354YA UT WOS:000089357800018 PM 10873789 ER PT J AU Salit, ML Vocke, RD Kelly, WR AF Salit, ML Vocke, RD Kelly, WR TI An ICP-OES method with 0.2% expanded uncertainties for the characterization of LiAlO2 SO ANALYTICAL CHEMISTRY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; INTERNAL STANDARDIZATION; PERFORMANCE; DETECTOR; LITHIUM AB An improved inductively coupled plasma-optical emission spectrometry (ICP-OES) method(1) has been applied to the determination of Li and Al mass fractions and the Li/Al amount-of-substance ratio in representative samples of LiAlO2. This ICP-OES method has uncertainty on the order of 0.2%,(2,3) comparable to the best analytical methods. This method is based on several strategies, which are detailed in this work. The mean measured mass fractions of Id and Al in eight samples were 0.10151 +/- 0.00016 (+/-0.16%) and 0.41068 +/- 0.00056 (+/-0.14%), and the mean Li/Al amount-of-substance ratio was 0.9793 +/- 0.0017 (+/-0.17%). The uncertainty is dominated by sample handling and heterogeneity-about a factor of 2 larger than the ICP-OES instrumental uncertainties, which were 0.04% for Al and 0.07% for Li. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Salit, ML (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Analyt Chem, 100 Bur Dr,M-S 8391, Gaithersburg, MD 20899 USA. NR 18 TC 20 Z9 20 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 2000 VL 72 IS 15 BP 3504 EP 3511 DI 10.1021/ac0000877 PG 8 WC Chemistry, Analytical SC Chemistry GA 340EP UT WOS:000088520400035 ER PT J AU Duewer, DL Kline, MC Sharpless, KE Thomas, JB Stacewicz-Sapuntzakis, M Sowell, AL AF Duewer, DL Kline, MC Sharpless, KE Thomas, JB Stacewicz-Sapuntzakis, M Sowell, AL TI NIST Micronutrients Measurement Quality Assurance Program: Characterizing individual participant measurement performance over time SO ANALYTICAL CHEMISTRY LA English DT Article ID VITAMIN-RELATED-COMPOUNDS AB The mission of the Micronutrients Measurement Quality Assurance Program (M(2)QAP) at the National institute of Standards and Technology is enhanced interlaboratory measurement comparability for fat-soluble vitamin-related measurands in human serum. We recently described improved tools for evaluating individual participant measurement performance in single interlaboratory comparison exercises; we here apply and extend these tools to the evaluation of participant performance over the entire 15-year history of the M(2)QAP. We describe and illustrate a set of interconnected graphical reporting tools for identifying long-term trends and single-exercise events. We document and discuss recurrent patterns we observe in the measurement performance characteristics for M(2)QAP participants. The graphical analysis techniques utilized may he applicable to other interlaboratory comparison programs. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Illinois, Dept Human Nutr & Dietet, Chicago, IL 60612 USA. Ctr Dis Control & Prevent, Nutr Biochem Branch, Atlanta, GA 30341 USA. RP Duewer, DL (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008; OI Sharpless, Katherine/0000-0001-6569-198X NR 7 TC 20 Z9 20 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 2000 VL 72 IS 15 BP 3611 EP 3619 DI 10.1021/ac991481b PG 9 WC Chemistry, Analytical SC Chemistry GA 340EP UT WOS:000088520400050 PM 10952550 ER PT J AU Zou, L Rishbeth, H Muller-Wodarg, ICF Aylward, AD Millward, GH Fuller-Rowell, TJ Idenden, DW Moffett, RJ AF Zou, L Rishbeth, H Muller-Wodarg, ICF Aylward, AD Millward, GH Fuller-Rowell, TJ Idenden, DW Moffett, RJ TI Annual and semiannual variations in the ionospheric F2-layer. I. Modelling SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article DE atmospheric composition and structure; thermosphere-composition and chemistry; ionosphere; mid-latitude ionosphere; modelling and forecasting ID THERMOSPHERE; CIRCULATION; NITROGEN; DENSITY; STORM; GAS AB Annual, seasonal and semiannual variations of F2-layer electron density (NmF2) and height (hmF2) have been compared with the coupled thermosphere-ionosphere-plasmasphere computational model (CTIP), for geomagnetically quiet conditions. Compared with results from ionosonde data from midlatitudes, CTIP reproduces quite well many observed features of NmF2, such as the dominant winter maxima at high midlatitudes in longitude sectors near the magnetic poles, the equinox maxima in sectors remote from the magnetic poles and at lower latitudes generally, and the form of the month-to-month variations at latitudes between about 60 degrees N and 50 degrees S. CTIP also reproduces the seasonal behaviour of NmF2 at midnight and the summer-winter changes of hmF2. Some features of the F2-layer, not reproduced by the present version of CTIP, are attributed to processes not included in the modelling. Examples are the increased prevalence of the winter maxima of noon NmF2 at higher solar activity, which may be a consequence of the increase of F2-layer loss rate in summer by vibrationally excited molecular nitrogen, and the semiannual variation in hmF2, which may be due to tidal effects. An unexpected feature of the computed distributions of NmF2 is an east-west hemisphere difference, which seems to be linked to the geomagnetic field configuration. Physical discussion is reserved to the companion paper by Rishbeth et al. C1 Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. UCL, Atmospher Phys Lab, London W1P 7PP, England. Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Sheffield, Sch Math & Stat, Sheffield S3 7RH, S Yorkshire, England. RP Rishbeth, H (reprint author), Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. EM hr@phys.soton.ac.uk RI Mueller-Wodarg, Ingo/M-9945-2014 OI Mueller-Wodarg, Ingo/0000-0001-6308-7826 NR 52 TC 70 Z9 76 U1 4 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0992-7689 J9 ANN GEOPHYS-ATM HYDR JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD AUG PY 2000 VL 18 IS 8 BP 927 EP 944 DI 10.1007/s00585-000-0927-8 PG 18 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 349ZC UT WOS:000089074700009 ER PT J AU Rishbeth, H Muller-Wodarg, ICF Zou, L Fuller-Rowell, TJ Millward, GH Moffett, RJ Idenden, DW Aylward, AD AF Rishbeth, H Muller-Wodarg, ICF Zou, L Fuller-Rowell, TJ Millward, GH Moffett, RJ Idenden, DW Aylward, AD TI Annual and semiannual variations in the ionospheric F2-layer: II. Physical discussion SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article DE atmospheric composition and structure; thermosphere-composition and chemistry; ionosphere; mid-latitude ionosphere; modelling and forecasting ID CIRCULATION; PRECIPITATION; THERMOSPHERE; MIDDLE; STORM; MODEL AB The companion paper by Zou et al. shows that the annual and semiannual variations in the peak F2-1ayer electron density (NmF2) at midlatitudes can be reproduced by a coupled thermosphere-ionosphere computational model (CTIP), without recourse to external influences such as the solar wind, or waves and tides originating in the lower atmosphere. The present work discusses the physics in greater detail. It shows that noon NmF2 is closely related to the ambient atomic/molecular concentration ratio, and suggests that the variations of NmF2 with geographic and magnetic longitude are largely due to the geometry of the auroral ovals. It also concludes that electric fields play no important part in the dynamics of the midlatitude thermosphere. Our modelling leads to the following picture of the global three-dimensional thermospheric circulation which, as envisaged by Duncan, is the key to explaining the F2-layer variations. At solstice, the almost continuous solar input at high summer latitudes drives a prevailing summer-to-winter wind, with upwelling at low latitudes and throughout most of the summer hemisphere, and a zone of downwelling in the winter hemisphere, just equatorward of the auroral oval. These motions affect thermospheric composition more than do the alternating day/night (np-and-down) motions at equinox. As a result, the thermosphere as a whole is more molecular at solstice than at equinox. Taken in conjunction with the well-known relation of F2-layer electron density to the atomic/molecular ratio in the neutral air, this explains the F2-layer semiannual effect in NmF2 that prevails at low and middle latitudes. At higher midlatitudes, the seasonal behaviour depends on the geographic latitude of the winter downwelling zone, though the effect of the composition changes is modified by the large solar zenith angle at midwinter. The zenith angle effect is especially important in longitudes far from the magnetic poles. Here, the downwelling occurs at high geographic latitudes, where the zenith angle effect becomes overwhelming and causes a midwinter depression of electron density, despite the enhanced atomic/molecular ratio. This leads to a semiannual variation of NmF2. A different situation exists in winter at longitudes near the magnetic poles, where the downwelling occurs at relatively low geographic latitudes so that solar radiation is strong enough to produce large values of NmF2. This circulation-driven mechanism provides a reasonably complete explanation of the observed pattern of F2 layer annual and semiannual quiet-day variations. C1 Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. UCL, Atmospher Phys Lab, London W1P 7PP, England. Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Sheffield, Sch Math & Stat, Sheffield S3 7RH, S Yorkshire, England. RP Rishbeth, H (reprint author), Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. EM hr@phys.soton.ac.uk RI Mueller-Wodarg, Ingo/M-9945-2014 OI Mueller-Wodarg, Ingo/0000-0001-6308-7826 NR 36 TC 126 Z9 132 U1 5 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0992-7689 J9 ANN GEOPHYS-ATM HYDR JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD AUG PY 2000 VL 18 IS 8 BP 945 EP 956 DI 10.1007/s00585-000-0945-6 PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 349ZC UT WOS:000089074700010 ER PT J AU Kiffney, PM Richardson, JS Feller, MC AF Kiffney, PM Richardson, JS Feller, MC TI Fluvial and epilithic organic matter dynamics in headwater streams of southwestern British Columbia, Canada SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article DE organic matter; epilithic; fluvial; streams; headwater ID COASTAL RAINFOREST STREAM; PERIPHYTON BIOMASS; CARNATION CREEK; NEW-ZEALAND; CARBON; TRANSPORT; EXPORT; RIVER; PERSPECTIVE; WATERSHEDS AB To characterize organic matter dynamics in headwater streams of southwestern British Columbia, Canada, we monitored epilithic biomass and fluvial transport of organic matter. Fluvial organic matter was collected once to twice monthly from 7 streams: samples were processed as coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), and dissolved organic matter (DOM). Epilithon was collected monthly from unglazed, ceramic tiles in 12 stream reaches and measured for ash-free dry mass (AFDM) and chlorophyll-a. CPOM and FPOM concentrations were higher during the wet season (1 October-30 April) than the dry season (1 May-30 September). Averaged across sites, CPOM and FPOM concentrations were positively related to mean daily discharge averaged over the 7 days before sample collection. In contrast, discharge and DOM concentration were inversely related. DOM concentration was positively correlated to chlorophyll-a accrual. Seasonal variation in epilithic chlorophyll-a and AFDM accumulation was high. AFDM accumulation rates ranged from a low in January 1997 of 0.31 to a high of 3.6 mu g cm(-2) d(-1) in May 1997. As with organic matter in stream water, discharge influenced the temporal dynamics of epilithic biomass accumulation; there was a negative correlation between discharge and epilithic AFDM. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. Univ British Columbia, Dept Forest Sci, Vancouver, BC V6T 1Z4, Canada. RP Kiffney, PM (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Richardson, John/G-1513-2012 OI Richardson, John/0000-0001-8135-7447 NR 55 TC 38 Z9 40 U1 2 U2 7 PU E SCHWEIZERBARTSCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD AUG PY 2000 VL 149 IS 1 BP 109 EP 129 PG 21 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA 341LH UT WOS:000088591500006 ER PT J AU Steel, AB Levicky, RL Herne, TM Tarlov, MJ AF Steel, AB Levicky, RL Herne, TM Tarlov, MJ TI Immobilization of nucleic acids at solid surfaces: Effect of oligonucleotide length on layer assembly SO BIOPHYSICAL JOURNAL LA English DT Article ID MOLECULAR-INTERACTIONS; HIGH-DENSITY; DNA; GOLD; HYBRIDIZATION; MONOLAYERS; ARRAYS; MICROARRAYS; SPECTROSCOPY; ADSORPTION AB This report investigates the effect of DNA length and the presence of an anchoring group on the assembly of presynthesized oligonucleotides at a gold surface. The work seeks to advance fundamental insight into issues that impact the structure and behavior of surface-immobilized DNA layers, as in, for instance, DNA microarray and biosensor devices. The present study contrasts immobilization of single-stranded DNA (ssDNA) containing a terminal, 5' hexanethiol anchoring group with that of unfunctionalized oligonucleotides for lengths from 8 to 48 bases. Qualitatively, the results indicate that the thiol anchoring group strongly enhances oligonucleotide immobilization, but that the enhancement is reduced for longer strand lengths. interestingly, examination of the probe coverage as a function of strand length suggests that adsorbed thiol-ssDNA oligonucleotides shorter than 24 bases tend to organize in end-tethered, highly extended configurations for which the long-term surface coverage is largely independent of oligonucleotide length. For strands longer than 24 bases, the surface coverage begins to decrease notably with probe length. The decrease is consistent with a less ordered arrangement of the DNA chains, presumably reflecting increasingly polymeric behavior. C1 Gene Log Inc, Gaithersburg, MD 20878 USA. Columbia Univ, Dept Chem Engn & Appl Chem, New York, NY 10027 USA. Natl Inst Stand & Technol, Proc Sensing Grp, Gaithersburg, MD 20899 USA. RP Steel, AB (reprint author), Gene Log Inc, 708 Quince Orchard Rd, Gaithersburg, MD 20878 USA. NR 29 TC 430 Z9 439 U1 3 U2 78 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD AUG PY 2000 VL 79 IS 2 BP 975 EP 981 PG 7 WC Biophysics SC Biophysics GA 340YF UT WOS:000088563700033 PM 10920027 ER PT J AU Fairaill, CW Hare, JE Edson, JB McGillis, W AF Fairaill, CW Hare, JE Edson, JB McGillis, W TI Parameterization and micrometeorological measurement of air-sea gas transfer SO BOUNDARY-LAYER METEOROLOGY LA English DT Article; Proceedings Paper CT Symposium on Transfer Processes in the Natural Environment CY AUG 25-27, 1998 CL AUSTRALIAN ACAD SCI, CANBERRA, AUSTRALIA SP Australian Acad Sci HO AUSTRALIAN ACAD SCI DE gas flux; carbon dioxide; air-sea interaction; diffusion sublayer; turbulent transport ID ATMOSPHERIC SURFACE-LAYER; PATH CO2 ANALYZERS; WATER-VAPOR; EDDY-ACCUMULATION; FLUX MEASUREMENTS; TURBULENT FLUXES; BOUNDARY-LAYER; CARBON-DIOXIDE; SCALAR FLUXES; MASS-TRANSFER AB Because of the combination of small concentrations and/or small fluxes, the determination of air-sea gas fluxes presents unusual measurement difficulties. Direct measurements (i.e., eddy correlation) of the fluxes are rarely attempted. In the last decade, there has been an intense scientific effort to improve measurement techniques and to place bulk parameterizations of gas transfer on firmer theoretical grounds. Oceanic tracer experiments, near-surface mean concentration profiles, eddy accumulation, and direct eddy covariance methods have all been used. Theoretical efforts have focused primarily in the realm of characterizing the transfer properties of the oceanic molecular sublayer. Recent major field efforts organized by the U.S.A. (GASEX-98) and the European Union (ASGAMAGE) have yielded atmospheric-derived results much closer to those from oceanographic methods. In this paper, we review the physical basis of a bulk-to-bulk gas transfer parameterization that is generalized for solubility and Schmidt number. We also discuss various aspects of recent sensor and technique developments used for direct measurements and demonstrate experimental progress with results from ASGAMAGE and GASEX-98. It is clear that sensor noise, sensitivity, and cross talk with other species and even ship motion corrections still need improvement for accurate measurements of trace gas exchange over the ocean. Significant work remains to resolve issues associated with the effects of waves, bubbles, and surface films. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80303 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NR 110 TC 115 Z9 117 U1 1 U2 12 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-8314 EI 1573-1472 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD AUG PY 2000 VL 96 IS 1-2 BP 63 EP 105 DI 10.1023/A:1002662826020 PG 43 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 323VQ UT WOS:000087586000006 ER PT J AU Baldocchi, D Finnigan, J Wilson, K Paw U, KT Falge, E AF Baldocchi, D Finnigan, J Wilson, K Paw U, KT Falge, E TI On measuring net ecosystem carbon exchange over tall vegetation on complex terrain SO BOUNDARY-LAYER METEOROLOGY LA English DT Article; Proceedings Paper CT Symposium on Transfer Processes in the Natural Environment CY AUG 25-27, 1998 CL AUSTRALIAN ACAD SCI, CANBERRA, AUSTRALIA SP Australian Acad Sci HO AUSTRALIAN ACAD SCI DE AmeriFlux; FLUXNET; carbon balance; micrometeorology; deciduous forest; eddy covariance; ecophysiology ID WATER-VAPOR EXCHANGE; LONG-TERM MEASUREMENTS; BOREAL ASPEN FOREST; DECIDUOUS FOREST; FLUX MEASUREMENTS; DIOXIDE EXCHANGE; EDDY COVARIANCE; GAS-EXCHANGE; CO2 EFFLUX; ATMOSPHERE AB To assess annual budgets of CO2 exchange between the biosphere and atmosphere over representative ecosystems, long-term measurements must be made over ecosystems that do not exist on ideal terrain. How to interpret eddy covariance measurements correctly remains a major task. At present, net ecosystem CO2 exchange is assessed, by members of the micrometeorological community, as the sum of eddy covariance measurements and the storage of CO2 in the underlying air. This approach, however, seems unsatisfactory as numerous investigators are reporting that it may be causing nocturnal respiration flux densities to be underestimated. A new theory was recently published by Lee (1998, Agricultural and Forest Meteorology 91: 39-50) for assessing net ecosystem-atmosphere CO2 exchange (N-e) over non-ideal terrain. It includes a vertical advection term. We apply this equation over a temperate broadleaved forest growing in undulating terrain. Inclusion of the vertical advection term yields hourly, daily and annual sums of net ecosystem CO2 exchange that are more ecologically correct during the growing season. During the winter dormant period, on the other hand, corrected CO2 flux density measurements of an actively respiring forest were near zero. This observation is unrealistic compared to chamber measurements and model calculations. Only during midday, when the atmosphere is well-mixed, do measurements of N-e match estimates based on model calculations and chamber measurements. On an annual basis, sums of N-e without the advection correction were 40% too large, as compared with computations derived from a validated and process-based model. With the inclusion of the advection correction term, we observe convergence between measured and calculated values of N-e on hourly, daily and yearly time scales. We cannot, however, conclude that inclusion of a one-dimensional, vertical advection term into the continuity equation is sufficient for evaluating CO2 exchange over tall forests in complex terrain. There is an indication that the neglected term, u}(partial derivative cmacr/partial derivative x), is non-zero and that CO2 may be leaking from the sides of the control volume during the winter. In this circumstance, forest floor CO2 efflux densities exceed effluxes measured above the canopy. C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. CSIRO, Canberra, ACT 2601, Australia. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA. RP Baldocchi, D (reprint author), Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, 151 Hilgard Hall, Berkeley, CA 94720 USA. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 47 TC 193 Z9 215 U1 5 U2 18 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 AUG PY 2000 VL 96 IS 1-2 BP 257 EP 291 DI 10.1023/A:1002497616547 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 323VQ UT WOS:000087586000011 ER PT J AU Bridgeman, TB Messick, G Vanderploeg, HA AF Bridgeman, TB Messick, G Vanderploeg, HA TI Sudden appearance of cysts and ellobiopsid parasites on zooplankton in a Michigan lake: a potential explanation of tumor-like anomalies SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article AB Cysts on calanoid and cyclopoid copepods, previously reported as tumor-like anomalies (TLAs) in Lake Michigan and Europe, appeared briefly in Patterson Lake, a small Michigan inland lake. Cysts were rare (4% maximum) in samples collected on September 11, 1999, but appeared with high frequency on calanoid adults (49%) and cyclopoid nauplii (73%) in samples collected on October 16. By October 30, cysts were again rare (0.4% maximum). Cysts most commonly appeared on the lateral surface of the animal at the articulation of the 1(st) and 2(nd) prosomal segments and often consisted of herniated copepod tissues. Transparent, pyriform cysts co-occurred in low frequency with other types of cysts and are believed to be the trophomeres and gonomeres of ellobiopsid parasites. Histologic manifestations of cysts were diverse; herniations consisted of acellular yolk-like material and apparent host tissue, while cysts thought to be Ellobiopsis contained cells with different degrees of nuclear staining and unusual spherical bodies. Hernias were experimentally induced on live calanoid copepods by piercing the carapace with a fine needle, suggesting that ellobiopsid parasites may cause the hernias by puncturing the carapace of their hosts. Ellobiopsid parasites are common on marine crustacean zooplankton but have been recorded only once before in freshwater. C1 Univ Michigan, Cooperat Inst Lake Ecosyst Res, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Biol, Ann Arbor, MI 48109 USA. NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res Cooperat, Oxford Lab, Oxford, MD 21654 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Bridgeman, TB (reprint author), Univ Michigan, Cooperat Inst Lake Ecosyst Res, 830 N Univ Ave, Ann Arbor, MI 48109 USA. OI Vanderploeg, Henry/0000-0003-1358-8475 NR 12 TC 12 Z9 14 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 2000 VL 57 IS 8 BP 1539 EP 1544 DI 10.1139/cjfas-57-8-1539 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 335YA UT WOS:000088273200001 ER PT J AU Garrison, LP AF Garrison, LP TI Spatial and dietary overlap in the Georges Bank groundfish community SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID FISH ASSEMBLAGES; NICHE; LIZARDS AB Patterns in spatial and trophic resource partitioning in the fish community of the Georges Bank region are identified, accounting for size-based changes in diets. During autumn and spring, this community is divided into geographic assemblages of species that have high spatial overlap. Similarity in spatial distribution is primarily related to similarity in depth preferences, and seasonal differences in species composition within assemblages are related to migrations. There is also important trophic structure within the Georges Bank community separating predators based upon prey size and location in the water column. Ontogenetic changes in diets are an important feature of the trophic structure in this system, particularly in the major piscivores. Seasonal changes in trophic structure reflect both predator and prey migrations. Dietary overlap among predator types is independent of either spatial overlap or depth preferences. There is spatial segregation within trophic guilds, and this spatial partitioning reduces the potential for exploitative competition within this community. Given the observed spatial patterns in trophic structure, the geographic assemblages on Georges Bank may be considered ecologically distinct functional units within this ecosystem. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Garrison, LP (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 28 TC 37 Z9 41 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 2000 VL 57 IS 8 BP 1679 EP 1691 DI 10.1139/cjfas-57-8-1679 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 335YA UT WOS:000088273200015 ER PT J AU McLaughlin, SM Elsayed, EE Faisal, M AF McLaughlin, SM Elsayed, EE Faisal, M TI Analysis of extracellular proteins of two Perkinsus spp. isolated from the softshell clam Mya arenaria in vitro SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY LA English DT Article DE softshell clam; Perkinsus spp; serine protease; enzymes; temperature; salinity; culture; pathogenicity ID RIBOSOMAL-RNA GENE; CRASSOSTREA-VIRGINICA; IN-VITRO; MARINUS APICOMPLEXA; EASTERN OYSTER; PROPAGATION; PROTEASES; PATHOGEN; INFECTION; PRODUCTS AB Biochemical characterization of the extracellular proteins (ECP) of two softshell clam Perkinsus spp. cloned isolates. Perkinsus chesapeaki isolate G-117 and Perkinsus marinus H-49, was performed and compared to that of the oyster-derived P. marinus isolate P-1. G-117 and H-49 demonstrated distinct differences in enzyme activities; however, all three isolates shared common bands. Substrate-impregnated gels showed H-49 to possess proteolytic activities while G-117 did not. Inhibition studies revealed that H-49 ECP contain serine proteases similar to those described for P-1. The G-117 ECP lacked proteolytic activity but showed a higher production of lipolytic enzymes than H-49 or P-1. Optimal in vitro growth temperatures for the two clam isolates were generally lower than those for P-1. G-117 showed faster growth at lower salinities than either H-49 or P-1. Clam Perkinsus spp. isolates appear to be better adapted to lower salinities and temperatures than the P. marinus isolate of the eastern oyster. (C) 2000 Elsevier Science Inc. All rights reserved. C1 Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. Natl Ocean Serv, NOAA, Ctr Coastal Environm Hlth & Biomol Res, Oxford, MD 21654 USA. Cairo Univ, Fac Vet Med, Giza, Egypt. RP Faisal, M (reprint author), Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. EM faisal@vims.edu FU CSR NIH HHS [NA56 RG0141] NR 30 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1096-4959 EI 1879-1107 J9 COMP BIOCHEM PHYS B JI Comp. Biochem. Physiol. B-Biochem. Mol. Biol. PD AUG PY 2000 VL 126 IS 4 BP 587 EP 598 DI 10.1016/S0305-0491(00)00231-5 PG 12 WC Biochemistry & Molecular Biology; Zoology SC Biochemistry & Molecular Biology; Zoology GA 342TY UT WOS:000088662300014 PM 11026671 ER PT J AU Read, AJ Wade, PR AF Read, AJ Wade, PR TI Status of marine mammals in the United States SO CONSERVATION BIOLOGY LA English DT Review ID CONSERVATION BIOLOGY; POPULATION AB The 1994 amendments to the U.S. Marine Mammal Protection Act required, for the first time, an assessment of the status of every marine mammal stock in the United States. We draw conclusions about the status of marine mammals from assessments of 153 stocks conducted to meet the requirements of these amendments. We found important regional differences in the status of stocks. Most stocks in the Atlantic and Pacific experience human-induced mortality (takes), primarily from gill-net fisheries. The proportion of stocks with takes was lower in the Gulf of Mexico and Hawaii, areas with few gill-net fisheries. Estimated takes exceeded removal limits for 29% of stocks in the Atlantic, 14% in the Pacific, 8% in Alaska, 7% in the Gulf of Mexico, and 0% in Hawaii. Twenty-eight stocks are listed as threatened or endangered under the U.S. Endangered Species Act. Most, but not all, baleen whale stocks are recovering after cessation of commercial harvests. Many species of pelagic cetaceans, including beaked and sperm whales, are vulnerable to mortality in pelagic drift-net fisheries. Most pinniped stocks experience takes, but none of these takes exceeds removal limits, and all pinniped stocks on mainland coasts of the United States are increasing in abundance. Quantitative data on trends in abundance are available for few cetacean stocks, emphasizing the difficulty of monitoring trends in these species. These stock assessments have greatly advanced our understanding of the status of marine mammals in the United States, but information gaps remain, particularly regarding stock structure and possible mortality in unmonitored fisheries. C1 Duke Univ, Nicholas Sch Environm, Beaufort, NC 28516 USA. Natl Marine Mammal Lab, Natl Marine Fisheries Serv, Off Protected Resources, Seattle, WA 98115 USA. RP Read, AJ (reprint author), Duke Univ, Nicholas Sch Environm, 135 Duke Marine Lab Rd, Beaufort, NC 28516 USA. NR 16 TC 31 Z9 32 U1 2 U2 17 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD AUG PY 2000 VL 14 IS 4 BP 929 EP 940 DI 10.1046/j.1523-1739.2000.99107.x PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 338UV UT WOS:000088442400005 ER PT J AU D'agrosa, C Lennert-Cody, CE Vidal, O AF D'agrosa, C Lennert-Cody, CE Vidal, O TI Vaquita bycatch in Mexico's artisanal gillnet fisheries: Driving a small population to extinction SO CONSERVATION BIOLOGY LA English DT Article ID HARBOR PORPOISE; PHOCOENA-SINUS; CONSERVATION; MORTALITY; FISH AB The world's most endangered marine cetacean, the vaquita (Phocoena sinus), continues to be caught in small-mesh gillnet fisheries throughout much of its range. We monitored fishing effort and incidental vaquita mortality in the upper Gulf of California, Mexico, from January 1993 to January 1995 to study the magnitude and causes of the incidental take. Of those factors studied, including net mesh size, soaktime, and geographic area, none contributed significantly to the incidental mortality rate of the vaquita, implying that the principal cause of mortality is fishing with gillnets per se. The total estimated incidental mortality caused by the fleet of El Golfo de Santa Clara was 39 vaquitas per year (95% CI = 14, 93), over 17% of the most recent estimate of population size. El Golfo de Santa Clara is one of three main ports that support gillnet fisheries throughout the range of the vaquita. Preliminary results indicate that fishing effort for San Felipe, Baja California, is comparable to that of El Golfo de Santa Clara, suggesting that this estimate of incidental mortality of vaquitas represents a minimum. We strongly recommend a complete and permanent ban on gillnets in the area. Alternative or supplemental mitigation strategies include (1) a maximum annual allowable mortality limit of vaquitas; (2) mandatory observer coverage of all boats fishing within the Upper Gulf of California and Colorado River Delta Biosphere Reserve; (3) extension of the Upper Gulf of California and Colorado River Delta Biosphere Reserve to encompass all known vaquita habitat; (4) rigorous enforcement of new and existing regulations; and (5) development of alternative sources of income for gillnet fishers. C1 Inst Tecnol & Estudios Super Monterrey, Guaymas 85400, Sonora, Mexico. Interamer Trop Tuna Commiss, La Jolla, CA 92037 USA. RP D'agrosa, C (reprint author), Duke Univ, Marine Lab, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort, NC 28516 USA. NR 38 TC 56 Z9 60 U1 9 U2 48 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD AUG PY 2000 VL 14 IS 4 BP 1110 EP 1119 DI 10.1046/j.1523-1739.2000.98191.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 338UV UT WOS:000088442400021 ER PT J AU Chassignet, EP Arango, H Dietrich, D Ezer, T Ghil, M Haidvogel, DB Ma, CC Mehra, A Paiva, AM Sirkes, Z AF Chassignet, EP Arango, H Dietrich, D Ezer, T Ghil, M Haidvogel, DB Ma, CC Mehra, A Paiva, AM Sirkes, Z TI DAMEE-NAB: the base experiments SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article DE DAMEE,-NAB; base experiments; north Atlantic circulation ID COORDINATE OCEAN MODELS; GULF-OF-MEXICO; NORTH-ATLANTIC; MEDITERRANEAN OUTFLOW; EQUATORIAL ATLANTIC; FLORIDA CURRENT; HEAT-TRANSPORT; WIND-DRIVEN; CIRCULATION; VARIABILITY AB The results of an intercomparison experiment performed with five numerical ocean models of different architecture are presented, While all models are able to simulate the large-scale characteristics of the North Atlantic circulation with a fair degree of realism, they also exhibit differences that can be attributed to the choices made in vertical coordinates, domain size, and boundary conditions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Meteorol & Phys Oceanog, Miami, FL 33149 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Mississippi State Univ, Ctr Air Sea Technol, Stennis Space Ctr, MS 39529 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ So Mississippi, Ctr Ocean & Atmospher Modeling, Stennis Space Ctr, MS 39529 USA. RP Chassignet, EP (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Meteorol & Phys Oceanog, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. OI Ezer, Tal/0000-0002-2018-6071 NR 64 TC 71 Z9 73 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD AUG PY 2000 VL 32 IS 3-4 BP 155 EP 183 DI 10.1016/S0377-0265(00)00046-4 PG 29 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA 338UE UT WOS:000088441000001 ER PT J AU Ezer, T Mellor, GL AF Ezer, T Mellor, GL TI Sensitivity studies with the North Atlantic sigma coordinate Princeton Ocean Model SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article DE North Atlantic Ocean; sigma coordinate; Princeton Ocean Model ID GULF-STREAM; CIRCULATION; SIMULATIONS; VARIABILITY; SEPARATION AB The sigma coordinate, Princeton Ocean Model (POM) has been configured for the North Atlantic ocean between 5 degrees N and 50 degrees N as part of data assimilation, model predictability and intercomparison studies. The model uses a curvilinear orthogonal grid with higher resolution in the western North Atlantic and lower resolution in the eastern North Atlantic. A series of experiments, each one of a 10-year duration, are performed to evaluate the sensitivity of the ocean mean state and variability to model parameters and model configuration; these experiments include open vs. closed boundary conditions, low vs, high resolution grids, and different choices of diffusion and viscosity, The results show that the use of closed boundaries together with near-boundary buffer zones where temperature and salinity are relaxed towards the observed values give less realistic flows, weaker recirculation gyres and less realistic Gulf Stream separation than do open boundary conditions. The experiments show that the sensitivity of the ocean variability in the model to the choice of the Smagorinsky diffusion and viscosity coefficients significantly differs from one region to another and largely depends on other attributes such as the mean position of the Gulf Stream in each simulation. A 50% change in model resolution in the Gulf Stream region has a larger effect on ocean variability than a change of diffusivity by a factor of 10. In areas where either the high or the low resolution models have sufficient resolution, as in the Gulf of Mexico, they are able to produce variability comparable to that observed from altimeter data; elsewhere, model variability is underestimated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Ezer, T (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. NR 25 TC 36 Z9 39 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD AUG PY 2000 VL 32 IS 3-4 BP 185 EP 208 DI 10.1016/S0377-0265(00)00047-6 PG 24 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA 338UE UT WOS:000088441000002 ER PT J AU Petrik, R Levin, PS AF Petrik, R Levin, PS TI Estimating relative abundance of seagrass fishes: a quantitative comparison of three methods SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE throw traps; otter trawl; minnow trap; North Carolina; sampling methods ID POPULATION; MACROFAUNA AB Precise descriptions of ecological patterns are fundamental to generating hypotheses about both the patterns and the mechanisms generating them. Fishes in seagrass meadows are difficult to sample because dense vegetation and turbid water make it necessary to rely on traps, nets or enclosure devices. We compared the relative abundance of species and community structure in a North Carolina estuary caught by otter trawls, throw traps and minnow traps and determined how habitat structure affected estimates of abundance from the different sampling methods. We collected more fishes with otter trawls than with throw traps or minnow traps, and our estimates of species richness were highest with trawls. The rank order of pinfish, Lagodon rhomboides, abundance and species richness were concordant among all three sampling methods, but varied for pigfish, Orthopristis chrysoptera. Our results suggest that minnow traps and throw traps were not affected by variability in seagrass biomass. Our results also indicate that selection of a particular sampling method may have important consequences for conclusions drawn from studies using different methodologies. C1 Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. RP Levin, PS (reprint author), NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM phil.levin@noaa.gov NR 17 TC 11 Z9 11 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0378-1909 EI 1573-5133 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD AUG PY 2000 VL 58 IS 4 BP 461 EP 466 DI 10.1023/A:1007604314576 PG 6 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 331PX UT WOS:000088028400011 ER PT J AU Munroe, TA Allen, RL Baltz, DM Ross, SW AF Munroe, TA Allen, RL Baltz, DM Ross, SW TI Symphurus civitatium (Pleuronectiformes : Cynoglossidae), a second estuarine-occurring tonguefish off the southeastern United States and northern Gulf of Mexico SO ESTUARIES LA English DT Article ID LOUISIANA ESTUARY; JUVENILE FLATFISH; MICROHABITAT USE; ABUNDANCE; FISHES; CAROLINA; GEORGIA; DIVERSITY; SYSTEM AB Two species of tonguefishes, Symphurus plagiusa (Linnaeus 1766) and Symphurus civitatium Ginsburg 1951, occur sympatrically and sometimes syntopically in shallow water habitats in North Carolina and Louisiana estuaries. In North Carolina, approximately Pro of 430 small (< 75 mm SL) tonguefishes collected were S. civitatium, while in Barataria Bay, Louisiana, this species was more abundant and cosmopolitan in distribution than was S. plagiusa, comprising over 82% of 3,564 tonguefishes collected with a small beam trawl over a 2-yr period. Historical literature has regarded S. plagiusa as the only tonguefish species inhabiting inshore waters in both regions. Presence of a second Symphurus species in shallow estuaries has been overlooked, most probably due to difficulties in identifying early post-settlement juveniles because both species have similar morphologies and overlapping dorsal-fin and anal-fin ray counts. Juveniles can be readily recognized by differences in number of caudal-fin rays (10 in S. plagiusa versus 12 in S. civitatium), especially when used in combination with pigmentation patterns and posterior extent of the jaws relative to the posterior margin of the lower eye. The most distinctive pigmentation difference between juveniles of these two species (allowing for accurate identifications of over 98% of juveniles) is the absence in S. civitatium (12-61 mm SL) of a series of melanophores overlying pterygiophore regions of the dorsal and anal hm on the blind side. This feature contrasts markedly with that of juvenile S. plagiusa (12-65 mm SL), which are characterized by two interrupted, diagonal series of dark chromatophores converging, but not merging, with posterior tapering of the body Occurrence of two sympatric species of tonguefishes in estuarine environments in the northcentral Gulf of Mexico and southeastern U.S. potentially compromises results of earlier ecological and distributional studies that assumed presence of only a single tonguefish species in these regions. C1 Natl Museum Nat Hist, Natl Marine Fisheries Serv, Natl Systemat Lab, Washington, DC 20560 USA. Louisiana State Univ, Ctr Coastal Energy & Environm Resources, Coastal Fisheries Inst, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ctr Coastal Energy & Environm Resources, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA. N Carolina Natl Estuarine Res Reserve, Wilmington, NC 28409 USA. RP Munroe, TA (reprint author), Natl Museum Nat Hist, Natl Marine Fisheries Serv, Natl Systemat Lab, Washington, DC 20560 USA. RI Baltz, Donald/A-9374-2009 NR 39 TC 3 Z9 3 U1 0 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD AUG PY 2000 VL 23 IS 4 BP 439 EP 448 DI 10.2307/1353137 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 357TE UT WOS:000089516300002 ER PT J AU O'Connor, WP Chao, BF Zheng, DW Au, AY AF O'Connor, WP Chao, BF Zheng, DW Au, AY TI Wind stress forcing of the North Sea 'pole tide' SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE Chandler wobble; North Sea; pole tide; sea level; tides; winds ID EUROPEAN CONTINENTAL-SHELF; STORM-SURGE MODEL; NUMERICAL-MODEL; GLOBAL OCEANS; DYNAMICS; CIRCULATION; LEVEL AB We conduct numerical simulations of the wind forcing of sea level variations in the North Sea using a barotropic ocean model with realistic geography and bathymetry to examine the forcing of the 14 month 'pole tide', which is known to be anomalously large along the Denmark-Netherlands coast. The simulation input is the monthly mean surface wind stress field from the National Centers for Environmental Prediction (NCEP) reanalysis for the 40 year period 1958-1997. The ocean model output sea level response is then compared with 10 coastal tide gauge records from the Permanent Service for Mean Sea Level (PSMSL) over the same period of time. Besides the strong seasonal variations, several prominent quasi-periodicities exist near 7 years, 3 years, 14 months, 9 months and 6.5 months. Correlations and spectral analyses show remarkable agreement between the model output and the observations, particularly in the 14 month, or Chandler, period band. The latter indicates that the enhanced pole tide found in the North Sea along the Denmark-Netherlands coast is actually the coastal set-up response to wind stress forcing with a periodicity of around 14 months. We find no need to invoke a geophysical explanation involving resonance enhancement of the pole tide in the North Sea to explain the observations. C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. NOAA, NOS, Coast Survey Dev Lab, Silver Spring, MD 20910 USA. Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China. Raytheon ITSS, Lanham, MD 20706 USA. RP Chao, BF (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Code 926, Greenbelt, MD 20771 USA. RI Chao, Benjamin Fong/N-6156-2013 NR 51 TC 10 Z9 10 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD AUG PY 2000 VL 142 IS 2 BP 620 EP 630 DI 10.1046/j.1365-246x.2000.00184.x PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 339NG UT WOS:000088482700025 ER PT J AU Soden, BJ AF Soden, BJ TI The diurnal cycle of convection, clouds, and water vapor in the tropical upper troposphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIANCES; SATELLITE; HUMIDITY; METEOSAT AB Hourly observations of the 6.7 mu m water vapor radiances from geostationary satellites are used to document the diurnal cycle in upper tropospheric water vapor and its relationship to cloud cover and convection. A coherent diurnal cycle in tropical water vapor is observed which lags the variations in cloud cover by approximately 2 hours. The variations in upper tropospheric cloud and water vapor occur (roughly) in phase with changes in deep convection over land, but nearly 12 hours out of phase with those over ocean. This feature is shown to be associated with differences in the vertical structure of land and ocean convection and offers a useful test of convective parameterizations in atmospheric models. C1 Princeton Univ, Geophys Fluid Dynam Lab, Natl Ocean & Atmospher Adm, Princeton, NJ 08542 USA. RP Soden, BJ (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Natl Ocean & Atmospher Adm, Princeton, NJ 08542 USA. NR 14 TC 61 Z9 61 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2173 EP 2176 DI 10.1029/2000GL011436 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200001 ER PT J AU Angell, JK AF Angell, JK TI Difference in radiosonde temperature trend for the period 1979-1998 of MSU data and the period 1959-1998 twice as long SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERIC TEMPERATURE; AIR-TEMPERATURE; SURFACE; SATELLITE; OZONE; INHOMOGENEITIES; RECORDS; CLIMATE; WINTER AB The difference in temperature trend for the 20-year period 1979-1998 and 40-year period 1959-1998 is estimated from a 63-station global radiosonde network. The variability of radiosonde-station temperature trends, as measured by their standard deviation, is about twice as great for 1979-1998 as 1959-1998. The cooling trend in the 100-50 mb layer of the low stratosphere is similar in polar, temperate and tropical zones, and about twice as great during 1979-1998 as 1959-1998. The cooling trend in the 300-100 mb layer of extratropics is also greater during 1979-1998 than 1959-1998, but the slight tropical warming is almost the same for the 2 periods. The warming trend in the tropospheric 850-300 mb layer is similar during 1959-1998 and 1979-1998, except in the south temperate zone where there is indicated to be cooling during 1979-1998. At the surface of the north polar zone the warming trend during 1979-1998 is nearly 3 times the warming during 1959-1998. In the global average the surface and 850-300 mb warmings are the same during 1959-1998, but the surface warms relative to the 850-300 mb layer during 1979-1998. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Angell, JK (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 34 TC 11 Z9 14 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2177 EP 2180 DI 10.1029/2000GL011435 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200002 ER PT J AU Ross, MN Toohey, DW Rawlins, WT Richard, EC Kelly, KK Tuck, AF Proffitt, MH Hagen, DE Hopkins, AR Whitefield, PD Benbrook, JR Sheldon, WR AF Ross, MN Toohey, DW Rawlins, WT Richard, EC Kelly, KK Tuck, AF Proffitt, MH Hagen, DE Hopkins, AR Whitefield, PD Benbrook, JR Sheldon, WR TI Observation of stratospheric ozone depletion associated with Delta II rocket emissions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IN-SITU MEASUREMENT; MOTOR EXHAUST; ALUMINUM-OXIDE; PLUMES AB Ozone, chlorine monoxide, methane, and submicron particulate concentrations were measured in the stratospheric plume wake of a Delta II rocket powered by a combination of solid (NH4ClO4/Al) and liquid (LOX/kerosene) propulsion systems. We apply a simple kinetics model. describing the main features of gas-phase chlorine reactions in solid propellant exhaust plumes to derive the abundance of total reactive chlorine in the plume and estimate the associated cumulative ozone loss. Measured ozone loss during two plume encounters (12 and 39 minutes after launch) exceeded the estimate by about a factor of about two. Insofar as only the most significant gas-phase chlorine reactions are included in the calculation, these results suggest that additional plume wake chemical processes or emissions other than reactive chlorine from the Delta II propulsion system affect ozone levels in the plume. C1 Aerospace Corp, Environm Syst Directorate, Los Angeles, CA 90009 USA. Univ Colorado, Atmospher Sci Programme, Boulder, CO 80309 USA. Phys Sci Inc, Andover, MA 01810 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. World Meteorol Org, Environm Div, Geneva, Switzerland. Univ Missouri, Cloud & Aerosol Sci Lab, Rolla, MO 65401 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. RP Ross, MN (reprint author), Aerospace Corp, Environm Syst Directorate, POB 92957, Los Angeles, CA 90009 USA. RI Tuck, Adrian/F-6024-2011; Toohey, Darin/A-4267-2008 OI Tuck, Adrian/0000-0002-2074-0538; Toohey, Darin/0000-0003-2853-1068 NR 16 TC 18 Z9 18 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2209 EP 2212 DI 10.1029/1999GL011159 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200010 ER PT J AU Erle, F Platt, U Pfeilsticker, K AF Erle, F Platt, U Pfeilsticker, K TI Measurement of OBrO upper limits in the nighttime stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OPTICAL-ABSORPTION SPECTROSCOPY; BROMINE; ERROR; BRO; NO2 AB Recent balloon-borne spectroscopic observations of stratospheric OBrO absorption features [Renard et al., 1998] gave rise to speculations whether OBrO is an important nighttime reservoir for stratospheric bromine. We have analyzed direct moon light spectra collected during 6 Transall flights for OBrO absorption signatures occurring between 470 and 550 nm. OBrO absorptions were not detected by stratospheric measurements at mid- or high latitude, both early or late in the night, made in early winter, or spring. Using the recently measured OBrO absorption cross section (sigma(OBrO) = (1.8 +/- 0.5) x 10(-17) cm(2)) by Knight et al. [2000], or the previously assumed OBrO cross section (sigma(OBrO) = 1.5 x 10(-17) cm(2)) by Renard et al. [1998] [further on all the results based oil the latter cross section are given in 0 for direct comparison], our measurements imply an upper limit for stratospheric OBrO of < 6.4 (7.7) ppt (typically 2.5 (3) ppt), and as low as 1.5 (1.8) ppt for an assumed Gaussian profile that maximises at 28 km. Although our result is closer in magnitude to the results of Renard et al. [1998], it does not confirm their findings, but it points more to the results of a modeling study that reject sizeable amounts (< 0.01 ppt) of stratospheric OBrO being formed by known gas-phase reactions even using extreme assumptions in favor of OBrO at night [Chipperfield et al, 1998]. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Erle, F (reprint author), Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany. NR 17 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2217 EP 2220 DI 10.1029/2000GL011532 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200012 ER PT J AU Kasibhatla, P Levy, H Moxim, WJ Pandis, SN Corbett, JJ Peterson, MC Honrath, RE Frost, GJ Knapp, K Parrish, DD Ryerson, TB AF Kasibhatla, P Levy, H Moxim, WJ Pandis, SN Corbett, JJ Peterson, MC Honrath, RE Frost, GJ Knapp, K Parrish, DD Ryerson, TB TI Do emissions from ships have a significant impact on concentrations of nitrogen oxides in the marine boundary layer? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE; NOX AB The potential impact of ship emissions on concentrations of nitrogen oxides and reactive nitrogen compounds in the marine boundary layer is assessed using a global chemical transport model. The model predicts significant enhancements of these compounds over large regions, especially over the northern midlatitude oceans. This result is consistent with a recently published study, though the impacts predicted here are more widespread and the peak enhancements are not as large. However, comparisons of model results with recent measurements over the central North Atlantic Ocean do not provide support for these model predictions. While one cannot completely overlook the possibility that emissions of nitrogen oxides from ships may be overestimated, our analysis suggests that there may be a gap in our understanding of the chemical evolution of ship plumes as they mix into the background atmosphere in the marine boundary layer. On a related note, it is also possible that the overestimate of the impacts of ships on nitrogen oxides in the marine boundary layer by global models is due to the lack of parameterized representations of plume dynamics and chemistry in these models. C1 Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA. Michigan Technol Univ, Dept Civil & Environm Engn, Houghton, MI 49931 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80303 USA. RP Kasibhatla, P (reprint author), Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. RI Corbett, James/B-3321-2009; Kasibhatla, Prasad/A-2574-2010; Parrish, David/E-8957-2010; Pandis, Spyros/D-3680-2013; Ryerson, Tom/C-9611-2009; Frost, Gregory/I-1958-2013; OI Corbett, James/0000-0002-2588-3474; Parrish, David/0000-0001-6312-2724; Kasibhatla, Prasad/0000-0003-3562-3737; Pandis, Spyros/0000-0001-8085-9795 NR 8 TC 52 Z9 53 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2229 EP 2232 DI 10.1029/2000GL011387 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200015 ER PT J AU Burnett, WH Kamenkovich, VM Mellor, GL Gordon, AL AF Burnett, WH Kamenkovich, VM Mellor, GL Gordon, AL TI The influence of the pressure head on the Indonesian Seas circulation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PACIFIC AB A high resolution, regional, non-linear, barotropic ocean model (2D POM) was used to show that a pressure difference between the Pacific and Indian Ocean does not significantly influence the total transport of the Indonesian throughflow. C1 USN, Meteorol & Oceanog Command, Stennis Space Ctr, MS 39529 USA. Univ So Mississippi, Dept Marine Sci, Stennis Space Ctr, MS 39529 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Burnett, WH (reprint author), USN, Meteorol & Oceanog Command, Stennis Space Ctr, MS 39529 USA. RI Gordon, Arnold/H-1049-2011 OI Gordon, Arnold/0000-0001-6480-6095 NR 11 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 2000 VL 27 IS 15 BP 2273 EP 2276 DI 10.1029/1999GL010918 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 341JL UT WOS:000088587200026 ER PT J AU Law, BE Williams, M Anthoni, PM Baldocchi, DD Unsworth, MH AF Law, BE Williams, M Anthoni, PM Baldocchi, DD Unsworth, MH TI Measuring and modelling seasonal variation of carbon dioxide and water vapour exchange of a Pinus ponderosa forest subject to soil water deficit SO GLOBAL CHANGE BIOLOGY LA English DT Article DE biogeochemistry; carbon exchange; evaporation; latent heat exchange; micrometeorology; models; net ecosystem production; physiological ecology; transpiration ID BROAD-LEAVED FOREST; STOMATAL CONDUCTANCE; PRIMARY PRODUCTIVITY; DECIDUOUS FOREST; WESTERN OREGON; HARVARD FOREST; LEAF-AREA; ATMOSPHERE; PHOTOSYNTHESIS; RESPIRATION AB We conducted ecosystem carbon and water vapour exchange studies in an old-growth Pinus ponderosa forest in the Pacific North-west region of the United States. The canopy is heterogeneous, with tall multiaged trees and an open, clumped canopy with low leaf area. Carbon assimilation can occur throughout relatively mild winters, although night frosts can temporarily halt the process and physiological factors limit its efficiency. In contrast, carbon assimilation is often limited in the 'growing season' by stomatal closure associated with high evaporative demand (D) and soil water deficits. All of these factors present a challenge to effectively modelling ecosystem processes. Our objective was to generate an understanding of the controls on ecosystem processes across seasonal and annual cycles from a combination of fine-scale process modelling, ecophysiological measurements, and carbon and water vapour fluxes measured by the eddy covariance method. Flux measurements showed that 50% and 70% of the annual carbon uptake occurred outside the 'growing season' (defined as bud break to senescence, similar to days 125-275) in 1996 and 1997. On a daily basis in summer, net ecosystem productivity (NEP) was low when D and soil water deficits were large. Whole ecosystem water vapour fluxes (LE) increased from spring to summer (1.0-1.9 mm d(-1)) as conducting leaf area increased by 30% and as evaporative demand increased, while evaporation from the soil surface became a smaller portion of total LE as soil water deficits increased. The models underestimated soil evaporation, particularly following rain. In the SPA model, varying the temperature optimum for photosynthesis seasonally resulted in overestimation of carbon uptake in winter and spring, showing that in coniferous forests, assumptions about temperature optima are clearly important. Daily estimates of soil surface CO2 flux from measurements and site meteorological data demonstrated that modelling of soil CO2 flux based on an Arrhenius-type equation in CANPOND overestimated CO2 respired from the soil during drought and when temperatures were low. C1 Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. RP Law, BE (reprint author), Oregon State Univ, Dept Forest Sci, 328 Richardson Hall, Corvallis, OR 97331 USA. RI Baldocchi, Dennis/A-1625-2009; Williams, Mathew/G-6140-2016; OI Baldocchi, Dennis/0000-0003-3496-4919; Williams, Mathew/0000-0001-6117-5208; Law, Beverly/0000-0002-1605-1203 NR 60 TC 133 Z9 145 U1 5 U2 45 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD AUG PY 2000 VL 6 IS 6 BP 613 EP 630 DI 10.1046/j.1365-2486.2000.00339.x PG 18 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 345GJ UT WOS:000088808000002 ER PT J AU Syrjala, SE AF Syrjala, SE TI Critique on the use of the delta distribution for the analysis of trawl survey data SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE delta distribution; lognormal distribution; skewed distributions; estimation of the mean; estimation of abundance; trawl survey ID LOGNORMAL-BASED ESTIMATORS; PLANKTON SURVEYS; ROBUSTNESS; ABUNDANCE AB The sample mean, as an estimator of the population mean, is recognized as being sensitive to the presence of the occasional extreme observation that can occur, especially when sampling from a highly skewed distribution. When sample data are non-negative and right-skewed, the minimum variance unbiased estimator of the mean of the delta distribution (Delta -distribution) has been proposed as an appropriate alternative to the sample mean. Demersal trawl data were used to compare the behaviour of these two estimators. For the survey data analyzed, the Delta -distribution estimate of the mean was found to be greater than the sample mean, on average twice as large. Empirical populations were constructed by combining data from 16 annual surveys, so that sampling could be conducted from known populations. Goodness-of-fit tests on samples from these populations could not reliably detect the departure from the assumed lognormality for the positive observations in the samples. For these populations, however, the Delta -distribution estimator of the mean was found to be a positively biased estimator of the mean, indicating that this estimator is not robust to seemingly small departures from the assumed Delta -distribution. C1 NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP Syrjala, SE (reprint author), NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 20 TC 18 Z9 19 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD AUG PY 2000 VL 57 IS 4 BP 831 EP 842 DI 10.1006/jmsc.2000.0571 PG 12 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 365DU UT WOS:000089933800005 ER PT J AU Overholtz, WJ Link, JS Suslowicz, LE AF Overholtz, WJ Link, JS Suslowicz, LE TI Consumption of important pelagic fish and squid by predatory fish in the northeastern USA shelf ecosystem with some fishery comparisons SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE consumption; predation; diet compositions; pelagic fishes; predator diet analysis ID DOGFISH SQUALUS-ACANTHIAS; FOOD-CONSUMPTION; STOMACH CONTENTS; MARINE; REGRESSION; HAKE AB The fish biomass on the continental shelf off the eastern USA and Southeastern Canada has shifted towards a higher proportion of pelagic fishes in the 1990s. This study provides estimates of consumption by 12 piscivorous fishes on Atlantic mackerel (Scomber scombrus), Atlantic herring (Clupea harengus), butterfish (Peprilus triacanthus), sand lance (Ammodytes sp.), short-finned squid (Illex illecebrosus), and long-finned squid (Loligo pealei during 1977-1997. Results suggest that total consumption tall prey) by the 12 predatory fish species is probably large relative to standing stocks of the above prey. Total consumption by these piscivores (all prey) ranged from 1.5-3.0 million tonnes during this period. The flow of fish biomass from these prey pelagic species to these 12 predators is an important and large fraction of the overall energy budget of the Northeast USA shelf ecosystem. The abundance of prey fishes and squids was reflected in the diets of individual predators; for example several prey species, such as sand lance and Atlantic herring, were very prominent at specific times during the period 1977-1997. Consumption of pelagic fish and squid by predatory fish appears to equal or exceed landings in most years from 1977-1997. In several cases, notably for long-finned squid, Atlantic herring and butterfish, consumption by piscivores may approach or exceed the current estimates of maximum sustainable yield, suggesting that changes in predator abundance may have important implications for long-term fishery yields of pelagic species. (C) 2000 International Council for the Exploration of the Sea. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Overholtz, WJ (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 35 TC 60 Z9 70 U1 3 U2 19 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD AUG PY 2000 VL 57 IS 4 BP 1147 EP 1159 DI 10.1006/jmsc.2000.0802 PG 13 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 365DU UT WOS:000089933800034 ER PT J AU Schabetsberger, R Brodeur, R Ciannelli, L Napp, JM Swartzman, GL AF Schabetsberger, R Brodeur, R Ciannelli, L Napp, JM Swartzman, GL TI Diel vertical migration and interaction of zooplankton and juvenile walleye pollock (Theragra chalcogramma) at a frontal region near the Pribilof Islands, Bering Sea SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE Theragra chalcogramma; vertical distribution; acoustics; zooplankton; feeding ID TARGET-STRENGTH; SOUND-SCATTERING; PREY SELECTION; BEHAVIOR; FISHES; ALASKA; LIGHT; THERMOCLINES; EVACUATION; PALLAS AB The diel vertical migration of age-0-walleye pollock (Theragra chalcogramma Pallas) and their principal prey organisms were examined at a productive frontal region in the Bering Sea using 38 kHz acoustic measurements and net samples. Small copepods dominated the catch of depth-stratified plankton tows. Two copepod species (Calanus marshallae and Metridia pacifica), euphausiids and chaetognaths, exhibited strong diel vertical migrations, although the magnitude and timing of the migrations varied among taxa. Age-0 pollock dominated midwater trawl catches (92% by number) that targeted layers of strong acoustic backscatter. Distributions of target strengths (TS) recorded within the layers corresponded well with predicted values based on empirical length/TS relationships for age-0 walleye pollock. Juvenile pollock in these layers migrated from daytime maxima at 40 m depths to less than 20m at night. The proportion of large copepods, euphausiids, and chaetognaths in the diet of juvenile pollock increased with increasing fish size, but prey composition did not change significantly throughout the diel period. (C) 2000 International Council for the Exploration of the Sea. C1 Salzburg Univ, Inst Zool, A-5020 Salzburg, Austria. NOAA, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. NOAA, Appl Phys Lab, Seattle, WA 98115 USA. RP Schabetsberger, R (reprint author), Salzburg Univ, Inst Zool, Hellbrunnerstr 34, A-5020 Salzburg, Austria. EM Robert.Schabetsberger@sbg.ac.at NR 43 TC 61 Z9 61 U1 0 U2 11 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD AUG PY 2000 VL 57 IS 4 BP 1283 EP 1295 DI 10.1006/jmsc.2000.0814 PG 13 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 365DU UT WOS:000089933800046 ER PT J AU Sandera, S AF Sandera, S TI Editorial - Reflections of Moto Kanda SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Editorial Material C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Sandera, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, 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 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 2000 VL 42 IS 3 BP 245 EP 245 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 350TW UT WOS:000089118100001 ER PT J AU Sun, BM Groisman, PY AF Sun, BM Groisman, PY TI Cloudiness variations over the former Soviet Union SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE cloudiness; heavy precipitation; Russia; trends ID SEA-SURFACE TEMPERATURES; PRECIPITATION; CLIMATOLOGY; COVER; WARM AB In the former Soviet Union (FUSSR), low-level cloud cover has significantly decreased over the period 1936-1990. This change has an opposite sign to that of the total cloud cover. Analysis of the occurrences of cloud types suggests that the decrease in low-level cloud cover was primarily due to the decrease in stratiform clouds. The presence of stratiform clouds is generally related to atmospheric static stability and/or frontal system passages. Thus, the reported decrease in occurrence of these clouds could be caused by weakened atmospheric stability and/or circulation associated with the increase in surface air temperature and reduction of the meridional temperature gradient. A spectacular increase in cumulus clouds over the FUSSR has been discovered over the past several decades. This increase (bring supported by a significant increase of cirrus clouds) is a manifestation of intensified convective processes over Northern Eurasia in the second half of the 20th century, and is consistent with the observed increase in heavy precipitation. While over the European part of the FUSSR the increase in heavy precipitation (above 20 mm/day) is a part of the general increase in annual and summer precipitation totals over the past century and/or past 50 years, a statistically significant increase in heavy precipitation in Siberia has occurred when the precipitation frequency and totals declined over the past 60 years. The present findings (increase in cumulus and decrease in stratiform clouds) explain these phenomena. Changes in total cloud cover, and particularly in its components, indicate that cloud interaction with other climate variables is changing somewhat. Therefore, it would be important to extend this study to other regions of the globe when more related data are available. Copyright (C) 2000 Royal Meteorological Society. C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. Univ Massachusetts, Morrill Sci Ctr, Dept Geosci, Amherst, MA 01003 USA. RP Groisman, PY (reprint author), Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. RI Sun, Bomin/P-8742-2014 OI Sun, Bomin/0000-0002-4872-9349 NR 17 TC 64 Z9 79 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD AUG PY 2000 VL 20 IS 10 BP 1097 EP 1111 DI 10.1002/1097-0088(200008)20:10<1097::AID-JOC541>3.3.CO;2-X PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348UN UT WOS:000089005000004 ER PT J AU Butler, BD Haeffner, DR Lee, PL Welberry, TR AF Butler, BD Haeffner, DR Lee, PL Welberry, TR TI High-energy X-ray diffuse scattering using Weissenberg flat-cone geometry SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID TLSBOGEO4 AB A technique for the measurement of diffuse X-ray scattering on individual reciprocal-space planes using high-energy X-ray photons is described. The method is demonstrated using a disordered crystal of the compound TlSbOGeO4 and compared to data collected with a sealed-tube Cu anode source. Measurements were made on a synchrotron undulator beamline at an energy of 45 keV using Weissenberg flat-cone geometry and a storage phosphor (image) plate to detect the scattered X-rays. Advantages of the method include: extension of the accessible diffraction space to both higher and lower wavevectors, the ability to use crystals of irregular shape without the need for complicated absorption corrections, less need to prepare sample surfaces carefully, and the ability to filter fluorescence simply. C1 Argonne Natl Lab, Adv Photon Source, SRI CAT, Argonne, IL USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Haeffner, DR (reprint author), Argonne Natl Lab, Adv Photon Source, SRI CAT, Argonne, IL USA. EM haeffner@aps.anl.gov RI Welberry, Thomas/H-7847-2014 OI Welberry, Thomas/0000-0002-6906-9191 NR 5 TC 9 Z9 9 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8898 EI 1600-5767 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 2000 VL 33 BP 1046 EP 1050 DI 10.1107/S0021889800005318 PN 4 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 337LR UT WOS:000088363000007 ER PT J AU Cohn, SA Angevine, WM AF Cohn, SA Angevine, WM TI Boundary layer height and entrainment zone thickness measured by lidars and wind-profiling radars SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MIXED-LAYER; DEPTHS AB The authors examine measurements of boundary layer height z(i) and entrainment zone thickness observed with two lidars and with a radar wind profiler during the Flatland96 Lidars in Flat Terrain experiment. Lidar backscatter is proportional to aerosol content land some molecular scatter) in the boundary layer, and wind profiler backscatter depends on the refractive index structure (moisture gradients and turbulence strength). Although these backscatter mechanisms are very different, good agreement is found in measurements of z(i) at 1-h resolution. When the dataset is limited to daytime convective conditions (times between 1000 and 1700 LT), correlation coefficients between the profiler and each lidar are 0.87 and 0.95. Correlation between the two lidars is 0.99. Comparisons of entrainment zone thickness show less agreement, with correlation coefficients of about 0.6 between the profiler and lidars and 0.8 between the two lidars. The lidar measurements of z(i) make use of coefficients of a Haar continuous wavelet transform of the backscatter profile. The wind profiler measurements use a standard technique. The wavelet transform technique is shown to provide consistent results with lidar data at 1-s time resolution. C1 Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Cohn, SA (reprint author), Natl Ctr Atmospher Res, Atmospher Technol Div, POB 3000, Boulder, CO 80307 USA. RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 29 TC 133 Z9 139 U1 0 U2 18 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2000 VL 39 IS 8 BP 1233 EP 1247 DI 10.1175/1520-0450(2000)039<1233:BLHAEZ>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348JE UT WOS:000088981100001 ER PT J AU Li, J Wolf, WW Menzel, WP Zhang, WJ Huang, HL Achtor, TH AF Li, J Wolf, WW Menzel, WP Zhang, WJ Huang, HL Achtor, TH TI Global soundings of the atmosphere from ATOVS measurements: The algorithm and validation SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID TIROS-N; RETRIEVAL; SOUNDER; TEMPERATURE; RADIANCES AB The International Advanced Television and Infrared Observation Satellite Operational Vertical Sounder (ATOVS) Processing Package (IAPP) has been developed to retrieve the atmospheric temperature profile, moisture profile, atmospheric total ozone, and other parameters in both clear and cloudy atmospheres from the ATOVS measurements. The algorithm that retrieves these parameters contains four steps: 1) cloud detection and removal, 2) bias adjustment for ATOVS measurements, 3) regression retrieval processes, and 4) a nonlinear iterative physical retrieval. Nine (3 X 3) adjacent High-Resolution Infrared Sounder (HIRS)/3 spot observations, together with Advanced Microwave Sounding Unit-A observations remapped to the HIRS/3 resolution, are used to retrieve the temperature profile, moisture profile, surface skin temperature, total atmospheric ozone and microwave surface emissivity, and so on. ATOVS profile retrieval results are evaluated by root-mean-square differences with respect to radiosonde observation profiles. The accuracy of the retrieval is about 2.0 K for the temperature at 1-km vertical resolution and 3.0-6.0 K for the dewpoint temperature at 2-km vertical resolution in this study. The IAPP is now available to users worldwide for processing the real-time ATOVS data. C1 Univ Wisconsin, SSEC, CIMSS, Madison, WI 53706 USA. NOAA, Off Res & Applicat, Natl Environm Satellite, Data & Informat Serv, Madison, WI USA. China Meteorol Adm, Natl Satellite Meteorol Ctr, Beijing, Peoples R China. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies Space Sc, Madison, WI USA. RP Li, J (reprint author), Univ Wisconsin, SSEC, CIMSS, Rm 219,1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011; Wolf, Walter/E-7935-2011; Li, Jun/H-3579-2015 OI Menzel, W. Paul/0000-0001-5690-1201; Wolf, Walter/0000-0002-2102-8833; Li, Jun/0000-0001-5504-9627 NR 25 TC 106 Z9 125 U1 2 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2000 VL 39 IS 8 BP 1248 EP 1268 DI 10.1175/1520-0450(2000)039<1248:GSOTAF>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348JE UT WOS:000088981100002 ER PT J AU Falkovich, A Kalnay, E Lord, S Mathur, MB AF Falkovich, A Kalnay, E Lord, S Mathur, MB TI A new method of observed rainfall assimilation in forecast models SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID NUMERICAL WEATHER PREDICTION; NATIONAL-METEOROLOGICAL-CENTER; PHYSICAL INITIALIZATION; CUMULUS INITIALIZATION; SPECTRAL MODEL; GAGE DATA; PRECIPITATION; TROPICS; CLOUD; RATES AB A method to assimilate observed rain rates in the Tropics for improving initial fields in forecast models is proposed. It consists of a 6-h integration of a numerical forecast model; the specific humidity at every time step at each grid point is modified (nudged) in such a way that the total model precipitation accumulated during this integration becomes very close to that observed. An increase in the model precipitation is achieved by moistening the lower troposphere above a grid point with prescribed supersaturation; a decrease in the model rainfall is brought about by decreasing the specific humidity in the lower troposphere in proportion to the difference between the model and reference specific humidity profiles. The modified values depend on the difference between the model and target precipitation. The depth of the atmospheric column in which the humidity is changed is proportional to the target rain rate. Quality criteria of a rain assimilation procedure are proposed. The quality of the assimilation method was verified using a test in which precipitation generated by a forecast model without nudging ("control" experiment) was considered to be "quasi-target" data and the nudging procedure was used for assimilation of the rain produced in the control experiment. The following experiments were performed: control (C)-without nudging, "simulated nudge" (S)-nudging to the 6-h accumulated rainfall from the C experiment, and "satellite nudge"-nudging to the 6-h accumulated satellite-retrieved (observed) rainfall. Each experiment consisted of a 6-h forecast (first guess), analysis, next 6-h forecast (first guess), next analysis, and 24-h forecast. Nudging was applied during the two successive 6-h calculations of the first guess over the tropical belt. Parameters of the nudging procedure were determined in such a way that the assimilation procedure converged quickly and simulated the observed precipitation very closely. The difference in forecast fields between the S and C experiments after a 24-h forecast turned out to be small, indicating high quality of the assimilation procedure. The high sensitivity of forecast fields to the quality of rain retrieval is demonstrated. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC USA. RP Falkovich, A (reprint author), NCEP, EMC, 5200 Auth Rd,WWB,Room 209, Camp Springs, MD 20746 USA. RI Kalnay, Eugenia/F-4393-2010; OI Kalnay, Eugenia/0000-0002-9984-9906 NR 36 TC 26 Z9 28 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2000 VL 39 IS 8 BP 1282 EP 1298 DI 10.1175/1520-0450(2000)039<1282:ANMOOR>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348JE UT WOS:000088981100004 ER PT J AU Straka, JM Zrnic, DS Ryzhkov, AV AF Straka, JM Zrnic, DS Ryzhkov, AV TI Bulk hydrometeor classification and quantification using polarimetric radar data: Synthesis of relations SO JOURNAL OF APPLIED METEOROLOGY LA English DT Review ID DUAL-POLARIZATION RADAR; ATMOSPHERIC ICE PARTICLES; COLORADO CONVECTIVE STORMS; MULTIPARAMETER RADAR; DIFFERENTIAL PHASE; WEATHER RADAR; SIZE SPECTRA; PRECIPITATION DEVELOPMENT; OPERATIONAL APPLICATIONS; STRATIFORM REGION AB A new synthesis of information forming the foundation for rule-based systems to deduce dominant bulk hydrometeor types and amounts using polarimetric radar data is presented. The information is valid for a 10-cm wavelength and consists of relations that are based on an extensive list of previous and recent observational and modeling studies of polarimetric signatures of hydrometeors. The relations are expressed as boundaries and thresholds in a space of polarimetric radar variables. Thus, the foundation is laid out for identification of hydrometeor types (species), estimation of characteristics of hydrometeor species (size, concentrations, etc.), and quantification of bulk hydrometeor contents (amounts). A fuzzy classification algorithm that builds upon this foundation will be discussed in a forthcoming paper. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Univ Oklahoma, Ctr Anal & Predict Storms, Norman, OK 73019 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Zrnic, DS (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 203 TC 226 Z9 239 U1 4 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2000 VL 39 IS 8 BP 1341 EP 1372 DI 10.1175/1520-0450(2000)039<1341:BHCAQU>2.0.CO;2 PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348JE UT WOS:000088981100008 ER PT J AU Turchinskaya, M Smith, DT Roytburd, AL Kaiser, DL AF Turchinskaya, M Smith, DT Roytburd, AL Kaiser, DL TI Vortex pinning in microindented YBa2Cu3O7-x single crystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIC-FLUX PENETRATION; SUPERCONDUCTING (BI,PB)(2)SR2CA2CU3OX COMPOSITES; REGULAR ARRAY; FILMS; DEFECTS; POLYCRYSTALS; BOUNDARIES; TAPES; SHEAR; HTSC AB A high resolution magneto-optical technique with a magnetic indicator film was used to study the effect of a regular array of micrometer-sized mechanical indentations on magnetization dynamics at the surface of a twinned single crystal of YBa2Cu3O7-delta as a function of applied magnetic field, H-a (0 to +/- 68 mT) at temperatures in the range of 10-70 K. Direct visualization of the magnetic flux interaction with the individual indentations was observed for the first time. During magnetization at low H-a up to 15 mT at 60 K, the first row of indentations provides resistance to the flux front. In the indented area, flux is preferably pinned at the indentation sites. With increasing H-a, the vortex density at the indentations approaches the magnetic flux density in the surrounding material. During demagnetization down to H-a=0 mT, the outgoing flux is trapped by the indentations in areas where the density of the trapped flux is small; flux is also trapped along the (110) twin boundaries behind the indentations. For H-a=0 to +/- 10 mT, the average value of the magnetic induction gradient in the vicinity of an indentation is approximate to 0.4 mT/mu m at 20-60 K. The average induction gradient and, thus, the critical current density in the indented material is estimated to be 1.5-2 times greater than in the unindented material at temperatures from 40 to 70 K and H-a from 18 to 68 mT. (C) 2000 American Institute of Physics. [S0021- 8979(00)07715-X]. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Chem & Nucl Engn, College Pk, MD 20742 USA. RP Turchinskaya, M (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 30 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 2000 VL 88 IS 3 BP 1541 EP 1546 DI 10.1063/1.373852 PG 6 WC Physics, Applied SC Physics GA 334CA UT WOS:000088166500051 ER PT J AU Early, EA Barnes, PY Johnson, BC Butler, JJ Bruegge, CJ Biggar, SF Spyak, PR Pavlov, MM AF Early, EA Barnes, PY Johnson, BC Butler, JJ Bruegge, CJ Biggar, SF Spyak, PR Pavlov, MM TI Bidirectional reflectance round-robin in support of the Earth Observing System program SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CALIBRATION; EOS AB Laboratory measurements of the bidirectional reflectance distribution function (BRDF) of diffuse reflectors are required to support calibration in the Earth Observing System (EOS) program of the National Aeronautics and Space Administration. To assess the ability of the instrument calibration laboratories to perform accurate BRDF measurements, a round-robin with the National Institute of Standards and Technology (NIST) as the central laboratory was initiated by the EOS Project Science Office. The round-robin parameters include sample type, wavelength, and incident and viewing angles. The results show that the participating calibration laboratories are, with a few exceptions due to experimental techniques or sample properties, generally able to measure BRDF for the round-robin parameters to within 2% of the values measured by NIST. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Networks, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Sensor Calibrat Off, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Arizona, Ctr Opt Sci, Remote Sensing Grp, Tucson, AZ 85721 USA. Raytheon Santa Barbara Remote Sensing, Goleta, CA USA. Calif State Polytech Univ Pomona, Dept Chem, Pomona, CA 91768 USA. Swales Aerosp, Beltsville, MD USA. RP Early, EA (reprint author), Natl Inst Stand & Technol, Opt Technol Div, 100 Bur Dr,Stop 8442, Gaithersburg, MD 20899 USA. RI Butler, James/D-4188-2013 NR 22 TC 40 Z9 41 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 2000 VL 17 IS 8 BP 1077 EP 1091 DI 10.1175/1520-0426(2000)017<1077:BRRRIS>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 353GN UT WOS:000089266600007 ER PT J AU Schlatter, TW AF Schlatter, TW TI Variational assimilation of meteorological observations in the lower atmosphere: a tutorial on how it works SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 1999 CEDAR Meeting and CEDAR-GEM-SHINE Session CY JUN, 1999 CL BOULDER, COLORADO DE data assimilation; variational data assimilation; meteorological data assimilation; 3DVAR; 4DVAR ID OBJECTIVE ANALYSIS AB Data assimilation combines atmospheric measurements with knowledge of atmospheric behavior as codified in computer models, thus producing a "best" estimate of current conditions that is consistent with both information sources. The four major challenges in data assimilation are: (1) to generate an initial state for a computer forecast that has the same mass-wind balance as the assimilating model, (2) to deal with the common problem of highly non-uniform distribution of observations, (3) to exploit the value of proxy observations (of parameters that are not carried explicitly in the model), and (4) to determine the statistical error properties of observing systems and numerical model alike so as to give each information source the proper weight. Variational data assimilation is practiced at major meteorological centers around the world. It is based upon multivariate linear regression, dating back to Gauss, and Variational calculus. At the heart of the method is the minimization of a cost function, which guarantees that the analyzed fields will closely resemble both the background field (a short forecast containing a priori information about the atmospheric state) and current observations. The size of the errors in the background and the observations (the latter, arising from measurement and non-representativeness) determine how close the analysis is to each basic source of information. Three-dimensional variational (3DVAR) assimilation provides a logical framework for incorporating the error information (in the form of variances and spatial covariances) and deals directly with the problem of proxy observations. 4DVAR assimilation is an extension of 3DVAR assimilation that includes the time dimension; it attempts to find an evolution of model states that most closely matches observations taken over a time interval measured in hours. Both 3DVAR and, especially, 4DVAR assimilation require very large computing resources. Researchers are trying to find more efficient numerical solutions to these problems. Variational assimilation is applicable in the upper atmosphere, but practical implementation demands accurate modeling of the physical processes that occur at high altitudes and multiple sources of observations. Published by Elsevier Science Ltd. C1 NOAA, OAR FSL RFS, David Skaggs Res Ctr, Forecast Syst Lab, Boulder, CO 80305 USA. RP Schlatter, TW (reprint author), NOAA, OAR FSL RFS, David Skaggs Res Ctr, Forecast Syst Lab, 325 Broadway, Boulder, CO 80305 USA. RI Schlatter, Thomas /E-7480-2015 NR 16 TC 9 Z9 9 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD AUG PY 2000 VL 62 IS 12 BP 1057 EP 1070 DI 10.1016/S1364-6826(00)00096-1 PG 14 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 365ZK UT WOS:000089980200003 ER PT J AU Skrtic, D Antonucci, JM Eanes, ED Eichmiller, FC Schumacher, GE AF Skrtic, D Antonucci, JM Eanes, ED Eichmiller, FC Schumacher, GE TI Physicochemical evaluation of bioactive polymeric composites based on hybrid amorphous calcium phosphates SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE composites; amorphous calcium phosphate; remineralization; mechanical strength ID PHOSPHATE/METHACRYLATE COMPOSITES AB Amorphous calcium phosphate (ACP)-filled methacrylate composites were recently found to effectively remineralize in vitro caries-like enamel lesions. Their inferior mechanical properties compared to glass-filled composites, however, limit their use as a dental restorative material. In this study, the feasibility of introducing glass-forming elements (tetraethoxysilane or zirconyl chloride) during the low-temperature synthesis of ACP was investigated. Composites based on such hybrid fillers (mass fraction, 40%) were evaluated to establish whether hybridization strengthened the composites, ia improved interfacial interactions with the polymer phase without compromising the release of the mineral ions. Two types of visible-light cured resins were prepared: BTHZ resin from 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenyl] propane (BisGMA), triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA) and zirconyl methacrylate (ZrM), and TIP resin front TEGDMA and pyromellitic glycerol dimethacrylate (PMGDM). Hybridized fillers and BTHZ- and TP-based composites were characterized by the IR spectroscopy, X-ray diffraction, dissolution/transformation kinetic studies, and biaxial flexure strength (BFS) testing before and after immersion in buffered saline solutions. The feasibility of improving the BFS via hybridization, while retaining, if not enhancing the remineralizing potential was demonstrated for BTHZ-based composites. Both BFS and remineralizing ability of the TP-composites, however, deteriorated upon their exposure to an aqueous environment. Therefore, hybridized ACP-filled BTHZ composites have a potential for utilization in more demanding restorative, sealant, and adhesive applications. (C) 2000 John Wiley & Sons. Inc.*. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Dent & Med Mat Grp, Div Polymer, Gaithersburg, MD 20899 USA. Natl Inst Dent & Craniofacial Res, Mineral Chem & Struct Sect, NIH, Bethesda, MD USA. RP Skrtic, D (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, 100 Bur Dr,Stop 8546, Gaithersburg, MD 20899 USA. NR 12 TC 77 Z9 78 U1 2 U2 15 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD AUG PY 2000 VL 53 IS 4 BP 381 EP 391 DI 10.1002/1097-4636(2000)53:4<381::AID-JBM12>3.0.CO;2-H PG 11 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 336MU UT WOS:000088307500012 PM 10898879 ER PT J AU Tewari, YB Davis, AM Reddy, P Goldberg, RN AF Tewari, YB Davis, AM Reddy, P Goldberg, RN TI A thermodynamic study of the conversion of chorismate to isochorismate SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE apparent equilibrium constant; chorismate; enthalpy; entropy; Gibbs free energy; isochorismate synthase; transformed thermodynamic quantities ID ESCHERICHIA-COLI; SYNTHASE; ENTEROBACTIN; EQUILIBRIUM; PREPHENATE; PATHWAY; ENZYMES; ACID; ENTC AB Microcalorimetry and high performance liquid chromatography were used to conduct a thermodynamic investigation of the biochemical reaction chorismate(aq) = isochorismate(aq). This reaction occurs at the branch point of the chorismate metabolic pathway that leads to the synthesis of enterobactin. Isochorismate synthase, the enzyme that catalyzes this reaction, was prepared for this study by using molecular biology techniques. The equilibrium and calorimetric measurements were performed at T = 298.15 K and at the respective pHs 7.34 and 6.93. For the chemical reference reaction chorismate(2-)(aq) = isochorismate(2-)(aq), the equilibrium constant K = (0.84 +/- 0.04) and the standard molar enthalpy of reaction Delta(r)H(m)(O) = -(0.81 +/- 0.27) kJ . mol(-1) at T = 298.15 K and ionic strength I-m = 0. Under approximately physiological conditions, die apparent equilibrium constant K' = 0.83 and the standard transformed gibbs energy change Delta(r)G'(O)(m) = 0.48 kJ . mol(-1) for the overall biochemical reaction. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Goldberg, RN (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Mailstop 8312, Gaithersburg, MD 20899 USA. OI Davis, Andrew/0000-0001-7955-6236 NR 26 TC 6 Z9 6 U1 1 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD AUG PY 2000 VL 32 IS 8 BP 1057 EP 1070 PG 14 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 356XN UT WOS:000089469600009 ER PT J AU Black, RX Dole, RM AF Black, RX Dole, RM TI Storm tracks and barotropic deformation in climate models SO JOURNAL OF CLIMATE LA English DT Article ID HEMISPHERE WINTERTIME CIRCULATION; NORTHERN HEMISPHERE; TELECONNECTION PATTERNS; GENERAL-CIRCULATION; INSTABILITY; FLOW; PROPAGATION; STATISTICS; CCM3 AB The relationship between the time-mean planetary-scale deformation field and the structure of midlatitude storm tracks is studied in wintertime simulations of the National Center for Atmospheric Research (NCAR) Community Climate Model and the National Aeronautics and Space Administration (NASA) Goddard Earth Observing System model. Model biases are determined by contrasting model simulations (forced by observed SSTs) with parallel analyses of NCEP-NCAR reanalyses. Barotropic diagnostics are employed to identify potential dynamical linkages between regional biases in the midlatitude storm tracks and the horizontal deformation field. Initial observational analyses confirm that synoptic eddies are optimally configured to transfer kinetic energy to the mean flow in the jet exit regions, where strong stretching deformation exists. In these regions, the major axes of the synoptic eddies are aligned along the dilatation axes of the mean Row. Consequently, mean flow advection stretches synoptic eddies along their major axes, thereby increasing their anisotropy and weakening their kinetic energy. A strong link is identified between model biases in the horizontal structure of the midlatitude storm tracks and the representation of upper-tropospheric barotropic deformation. In particular, model-simulated storm tracks extend too far downstream in regions where the zonal stretching deformation (associated with horizontal diffluence in jet exit regions) is either too weak in magnitude or displaced westward in comparison with observations. These biases are associated with anomalously weak or westward-displaced patterns of negative barotropic energy conversions, which normally act as a sink of synoptic eddy activity in the jet exit. The anomalous energy conversion patterns are primarily due to model biases in the winter-mean Row rather than the simulated horizontal eddy structures, which closely resemble observations. The results indicate that the horizontal structure of midlatitude storm tracks in climate models is strongly controlled by the large-scale patterns of barotropic deformation in the upper troposphere. It is suggested that barotropic deformation analyses may provide a useful diagnostic measure for assessing climate simulation errors in atmospheric general circulation models. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NOAA, Climate Diagnost Ctr, Boulder, CO USA. RP Black, RX (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RI Black, Robert/L-8522-2014 NR 27 TC 17 Z9 18 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG 1 PY 2000 VL 13 IS 15 BP 2712 EP 2728 DI 10.1175/1520-0442(2000)013<2712:STABDI>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JB UT WOS:000088811900004 ER PT J AU Smith, TM AF Smith, TM TI Tropical Pacific sea level variations (1948-98) SO JOURNAL OF CLIMATE LA English DT Article ID NINO SOUTHERN OSCILLATION; EL-NINO; SURFACE TEMPERATURES; DATA ASSIMILATION; OCEAN; CLIMATE; VARIABILITY; SYSTEM; INTERPOLATION; PREDICTION AB Monthly sea level in the Pacific Ocean (30 degrees S-30 degrees N) is analyzed for the 1948-98 period. It is shown that most sea level variations in this region have large scales, and so the available network of tide gauge stations is sufficient for analysis over this period. Analysis is done using statistically optimal interpolation and the full covariance structure defined by a more recent well-sampled period. The analysis reflects major variations in the station data, including warm and cool episodes in the tropical Pacific and an increase in variance in the second half of the analysis period, At the tide gauge stations, the analysis correlation with observations generally exceeds 0.9. Cross-validation tests show that errors in the tropical Pacific sea level analysis are typically less than 4.5 cm throughout the analysis period and less than 3 cm in the best-sampled most recent period. This result compares well with the TOPEX/Poseidon (Ocean Topography Experiment) satellite error estimate of 2 cm. Rotated EOF analysis of the 1948-98 sea level anomalies shows the dominance of ENSO variations. Taken together, the first three modes account fur most of the variance and represent different phases of the ENSO cycle, with two buildup modes and a mature phase mode. One of the buildup modes is associated with a western Pacific warm pool centered north of the equator and is negatively correlated with variations in the east-equatorial Pacific. The other buildup mode is associated with a western Pacific warm pool centered south of the equator, which gives a strong indication of cast-equatorial Pacific variations a year in advance, An increasing trend in the sea level over the record period may be related to increasing variance in the sea level, which is reflected by stronger and more frequent ENSO variations in the second half of the record. C1 NOAA, Anal Branch, Climate Predict Ctr, NCEP,NWS, Camp Springs, MD 20746 USA. RP Smith, TM (reprint author), NOAA, Anal Branch, Climate Predict Ctr, NCEP,NWS, Camp Springs, MD 20746 USA. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 27 TC 15 Z9 18 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG 1 PY 2000 VL 13 IS 15 BP 2757 EP 2769 DI 10.1175/1520-0442(2000)013<2757:TPSLV>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JB UT WOS:000088811900007 ER PT J AU Bennett, AF Chua, BS Harrison, DE McPhaden, MJ AF Bennett, AF Chua, BS Harrison, DE McPhaden, MJ TI Generalized inversion of Tropical Atmosphere-Ocean (TAO) data and a coupled model of the tropical Pacific. Part II: The 1995-96 La Nina and 1997-98 El Nino SO JOURNAL OF CLIMATE LA English DT Article ID WEATHER PREDICTION MODEL; SOUTHERN OSCILLATION AB The investigation of the consequences of trying to blend tropical Pacific observations from the Tropical Atmosphere-Ocean (TAO) array into the dynamical framework of an intermediate coupled ocean-atmosphere model is continued. In a previous study it was found that the model dynamics, the prior estimates of uncertainty in the observations, and the estimates of the errors in the dynamical equations of the model could not be reconciled with data from the 1994-95 period. The error estimates and the data forced the rejection of the model physics as being unacceptably in error. In this work, data from two periods (1995-96 and 1997-98) were used when the tropical Pacific was in states very different from the previous study. The consequences of increasing the prior error estimates were explored in an effort to find out ii it is possible at least to use the intermediate model physics to assist in mapping the observations into fields in a statistically consistent way. It was found that such a result is possible for the new data periods, with larger prior error assumptions. However. examination of the behavior of the mapped fields indicates that they have no dynamical utility. The model dynamical residuals, that is, the size of the quantity that is left after evaluating all of the terms in each intermediate model equation, dominate the terms themselves. Evidently the intermediate model is not able to add insight into the processes that caused the tropical Pacific to behave as it was observed to, during these time intervals. The inverse techniques described here together with the relatively dense TAO dataset have made it possible for the unambiguous rejection of the nonlinear intermediate model dynamical system. This if the first time that for the unambiguous rejection of the nonlinear intermediate model dynamical system. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Oregon State Univ, Coll Ocean & Atmospher Sci, 104 Ocean Adm Bldg, Corvallis, OR 97331 USA. EM bennett@oce.orst.edu RI Harrison, Don/D-9582-2013; McPhaden, Michael/D-9799-2016 NR 11 TC 26 Z9 26 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD AUG 1 PY 2000 VL 13 IS 15 BP 2770 EP 2785 DI 10.1175/1520-0442(2000)013<2770:GIOTAO>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JB UT WOS:000088811900008 ER PT J AU de Verdiere, AC Huck, T AF de Verdiere, AC Huck, T TI A 2 degree of freedom dynamical system for interdecadal oscillations of the ocean-atmosphere SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; THERMOHALINE CIRCULATION; PARAMETER SENSITIVITY; HEAT-FLUX; VARIABILITY; MODEL; CLIMATE; ADJUSTMENT; DRIVEN AB A four-box model of the ocean-atmosphere is constructed that exhibits self-sustained oscillations in the regime of decadal to interdecadal periods found in oceanic general circulation models under certain boundary conditions. The oscillations are assumed to be caused by a type of baroclinic instability that relies on the store of available potential energy in the ocean. To represent this process in a low-order model, the authors propose Landau's equation to govern the evolution of the overturning branch of the oceanic circulation. The domains of the unstable oscillations are found from linear stability analysis, and the nonlinear regimes are explored numerically. On these long timescales the atmospheric temperatures follow the oceanic temperatures. If the atmospheric temperatures are forced to be constant, the oscillations become strongly damped and disappear The implications of the simple physics of this model for the decadal oscillations observed in more complex two- or three-dimensional GCMs are discussed. C1 Univ Bretagne Occidentale, Lab Phys Oceans, F-29285 Brest, France. Princeton Univ, Princeton, NJ 08544 USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. RP de Verdiere, AC (reprint author), Univ Bretagne Occidentale, Lab Phys Oceans, 6 Ave Le Gorgeu,BP 809, F-29285 Brest, France. RI Huck, Thierry/L-5549-2015 OI Huck, Thierry/0000-0002-2885-5153 NR 39 TC 1 Z9 1 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG 1 PY 2000 VL 13 IS 15 BP 2801 EP 2817 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JB UT WOS:000088811900011 ER PT J AU Gioffre, M Grigoriu, M Kasperski, M Simiu, E AF Gioffre, M Grigoriu, M Kasperski, M Simiu, E TI Wind-induced peak bending moments in low-rise building frames SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB We present a procedure for estimating peaks of non-Gaussian processes representing fluctuating internal forces induced by wind in low-rise building frames. The procedure is designed for inclusion in computer programs that use surface pressure databases to obtain peak internal forces in frames. In general, the processes of interest are non-Gaussian, and we apply translation models to estimate the distribution of their peaks. To illustrate the procedure we calibrate a translation model to the record of a 1 h time history of the bending moment at the upwind bent of a low-rise frame. C1 Univ Perugia, Fac Engn, Inst Energy Sci, I-06125 Perugia, Italy. Cornell Univ, Dept Civil & Environm Engn, Ithaca, NY 14853 USA. Ruhr Univ Bochum, D-4630 Bochum, Germany. Natl Inst Stand & Technol, Build & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Gioffre, M (reprint author), Univ Perugia, Fac Engn, Inst Energy Sci, I-06125 Perugia, Italy. NR 3 TC 16 Z9 16 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD AUG PY 2000 VL 126 IS 8 BP 879 EP 881 PG 3 WC Engineering, Mechanical SC Engineering GA 337PD UT WOS:000088370100013 ER PT J AU St Cyr, OC Howard, RA Sheeley, NR Plunkett, SP Michels, DJ Paswaters, SE Koomen, MJ Simnett, GM Thompson, BJ Gurman, JB Schwenn, R Webb, DF Hildner, E Lamy, PL AF St Cyr, OC Howard, RA Sheeley, NR Plunkett, SP Michels, DJ Paswaters, SE Koomen, MJ Simnett, GM Thompson, BJ Gurman, JB Schwenn, R Webb, DF Hildner, E Lamy, PL TI Properties of coronal mass ejections: SOHO LASCO observations from January 1996 to June 1998 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID DISCONNECTED MAGNETIC-STRUCTURE; SOLAR-WIND; SMM OBSERVATIONS; WHITE-LIGHT; FLOW SPEEDS; FLUX ROPE; APRIL 7; EIT; TRANSIENT; EARTH AB We report the properties of all the 841 coronal mass ejections (CMEs) observed by the Solar and Heliospheric Observatory (SOHO) Large Angle Spectroscopic Coronagraph (LASCO) C2 and C3 white-light coronagraphs from January 1996 through June 1998, and we compare those properties to previous observations by other similar instruments. Both the CME rate and the distribution of apparent locations of CMEs varied during this period as expected based on previous solar cycles. The distribution of apparent speeds and the fraction of CMEs showing acceleration were also in agreement with earlier reports. The pointing stability provided by an L-l orbit and the use of CCD detectors have resulted in superior brightness sensitivity for LASCO over earlier coronagraphs; however, we have not detected a significant population of fainter (i.e., low mass) CMEs. The general shape of the distribution of apparent sizes for LASCO CMEs is similar to those of earlier reports, but the average (median) apparent size of 72 degrees (50 degrees) is significantly larger. The larger average apparent size is predominantly the result of the detection of a population of partial and complete halo CMEs at least some of which appear to be events with a significant longitudinal component directed along the Sun-Earth line, either toward or away from the Earth. Using full disk solar images obtained by the Extreme ultraviolet Imaging Telescope (EIT) on SOHO, we found that 40 out of 92 of these events might have been directed toward the Earth, and we compared the timing of those with the I(I) geomagnetic storm index in the days following the CME, Although the "false alarm" rate was high, we found that 15 out of 21 (71%) of the K-p greater than or equal to 6 storms could be accounted for as SOHO LASCO/EIT frontside halo CMEs. If we eliminate three Kp, storms that occurred following LASCO/EIT data gaps. then the possible association rate was 15 out of 18 (83%). C1 Computat Phys Inc, Fairfax, VA USA. USN, Res Lab, Washington, DC 20375 USA. Univ Space Res Assoc, Washington, DC USA. Ball Aerosp Corp, Boulder, CO 80301 USA. Sachs Freeman Associates Inc, Naval Res Lab, Washington, DC 20375 USA. Univ Birmingham, Sch Phys & Space Res, Birmingham B15 2TT, W Midlands, England. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Max Planck Inst Aeron, D-37189 Lindau, Germany. Boston Coll, Inst Sci Res, Chestnut Hill, MA 02167 USA. Space Vehicles Directorate, Air Force Res Lab, Hanscom AFB, MA USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Astron Spatiale Lab, F-13248 Marseille, France. RP Computat Phys Inc, Fairfax, VA USA. RI Thompson, Barbara/C-9429-2012 NR 73 TC 347 Z9 347 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18169 EP 18185 DI 10.1029/1999JA000381 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600001 ER PT J AU Garcia, FJ Kelley, MC Makela, JJ Sultan, PJ Pi, X Musman, S AF Garcia, FJ Kelley, MC Makela, JJ Sultan, PJ Pi, X Musman, S TI Mesoscale structure of the midlatitude ionosphere during high geomagnetic activity: Airglow and GPS observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID F-REGION; ELECTRIC-FIELD; ARECIBO; NETWORK AB On the night of November 22, 1997, the Cornell All-Sky Imager recorded a spectacular display of structure in the 630.0 nm emission over Arecibo, Puerto nice. This event is an example of a phenomenon we have termed "intense midlatitude spread F." In this paper we describe the stormtime geophysical conditions for the period and detail the evolution of the event. The daytime midlatitude ionosphere was disturbed for four consecutive days. The initial daytime doubling of the total electron content (TEC) was associated with equatorward propagation of a high-TEC patch that seemed to have associated composition changes. The following days had distinct diurnal double maxima (DDM). The TEC in the Caribbean was very high during the first night of the storm and was extremely structured. Airglow depletions and enhancements surged poleward, bifurcating numerous times in the process. The airglow depletions were collocated wit;ll TEC minima along similar lines of sight to Global Positioning System satellites. Eventually, four parallel and very similar airglow wave packets were visible and oriented at an angle similar to the less violent structures reported in the companion paper [Garcia et al., this issue] and moving slowly toward the southwest. We explore a number of possible explanations for these features. We are most confident that secondary instabilities of the generalized ExB process can explain the evolution of the structures once they are formed. The initial process itself remains controversial. C1 Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Geosci Res Div, Silver Spring, MD 20910 USA. RP Garcia, FJ (reprint author), Cornell Univ, Sch Elect Engn, 318 Rhodes Hall, Ithaca, NY 14853 USA. NR 17 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18417 EP 18427 DI 10.1029/1999JA000306 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600020 ER PT J AU Dettinger, MD Diaz, HF AF Dettinger, MD Diaz, HF TI Global characteristics of stream flow seasonality and variability SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID SEA-SURFACE TEMPERATURES; WESTERN NORTH-AMERICA; SOUTHERN OSCILLATION; UNITED-STATES; EL-NINO; CLIMATE VARIABILITY; TROPICAL PACIFIC; PRECIPITATION; CIRCULATION; PATTERNS AB Monthly stream flow series from 1345 sites around the world are used to characterize geographic differences in the seasonality and year-to-year variability of stream how. Stream flow seasonality varies regionally, depending on the timing of maximum precipitation, evapotranspiration, and contributions from snow and ice. Lags between peaks of precipitation and stream flow vary smoothly from long delays in high-latitude and mountainous regions to short delays in the warmest sectors. Stream flow is most variable from year to year in dry regions of the southwest United States and Mexico, the Sahel, and southern continents, and it varies more (relatively) than precipitation in the same regions. Tropical rivers have the steadiest hows. El Nino variations are correlated with stream flow in many parts of the Americas, Europe, and Australia. Many stream flow series from North America, Europe, and the Tropics reflect North Pacific climate, whereas series from the eastern United States, Europe, and tropical South America and Africa reflect North Atlantic climate variations. C1 Univ Calif San Diego, Scripps Inst Oceanog, US Geol Survey, Dept 0224, La Jolla, CA 92093 USA. NOAA, OAR, Climate Diagnost Ctr, Boulder, CO USA. RP Dettinger, MD (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, US Geol Survey, Dept 0224, 9500 Gilman Dr, La Jolla, CA 92093 USA. NR 66 TC 143 Z9 146 U1 5 U2 32 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD AUG PY 2000 VL 1 IS 4 BP 289 EP 310 DI 10.1175/1525-7541(2000)001<0289:GCOSFS>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357VE UT WOS:000089520800001 ER PT J AU Kim, J Miller, NL Farrara, JD Hong, SY AF Kim, J Miller, NL Farrara, JD Hong, SY TI A seasonal precipitation and stream flow hindcast and prediction study in the western United States during the 1997/98 winter season using a dynamic downscaling system SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODEL; OROGRAPHIC PRECIPITATION; WEATHER PREDICTION; BOUNDARY-LAYER; SNOW BUDGET; RIVER FLOW; SIMULATION; CALIFORNIA; SCHEME; PARAMETERIZATION AB The authors present a seasonal hindcast and prediction of precipitation in the western United States and stream flow in a northern California coastal basin for December 1997-February 1998 (DJF) using the Regional Climate System Model (RCSM). In the seasonal hindcast simulation, in which the twice-daily National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis was used for the initial conditions and time-dependent boundary forcing, RCSM has simulated realistically the temporal and spatial variations of precipitation in California and stream flow in a northern California coastal basin. For the headwater basin of the Russian River in the northern California Coast Ranges, the Topography-Based Hydrologic Model (TOP-MODEL) forced by observed daily precipitation resulted in a correlation coefficient of 0.88 between observed and simulated DJF stream flow. In the coupled stream flow hindcast, the authors obtained a correlation coefficient of 0.7 between simulated and observed stream flow for the same period. The coupled hindcast has generally overestimated(underestimated) low (high) flow events in the basin. Errors in the simulated stream flow were due mostly to the errors in the simulated precipitation. A seasonal hydroclimate prediction experiment, in which RCSM was nested within the global forecast data from the University of California, Los Angeles, GCM, has predicted well the season-total precipitation in the western United States. Temporal variations of predicted precipitation were affected strongly by the predictability of the general circulation model. The predicted DJF-total snowfall agrees well with the snowfall simulated in the hindcast, especially in the central Cascades and the Sierra Nevada, where snowfall was the heaviest. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. Natl Ctr Environm Predict, Environm Modeling Ctr, Camp Springs, MD USA. RP Kim, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS90-1116,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Hong, Song-You/I-3824-2012 NR 55 TC 44 Z9 44 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD AUG PY 2000 VL 1 IS 4 BP 311 EP 329 DI 10.1175/1525-7541(2000)001<0311:ASPASF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357VE UT WOS:000089520800002 ER PT J AU Crawford, TM Stensrud, DJ Carlson, TN Capehart, WJ AF Crawford, TM Stensrud, DJ Carlson, TN Capehart, WJ TI Using a soil hydrology model to obtain regionally averaged soil moisture values SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID NUMERICAL WEATHER PREDICTION; PROFILE MODEL; WATER CONTENT; SURFACE; PARAMETERIZATION; AVAILABILITY; VEGETATION AB The Soil Hydrology Model (SHM) was modified, and daily simulations of soil volumetric water content were made at 38 Oklahoma Mesonet sites for July 1997. These model results were compared with soil moisture observations made at the mesonet sites at depths of 5. 25, 60, and 75 cm. This work is believed to be the first time that a hydrological model has been evaluated with in situ soil moisture measurements over such an extensive area spanning several climate zones. Comparisons of time series between the observed and modeled domain-averaged volumetric water content at 5 cm revealed similar phase and amplitude changes, a coefficient of determination (R-2) Of 0.64, and small mean bias and root-mean-square errors (MBE and rmse) of 0.03 and 0.09, respectively. At 25, 60, and 75 cm, the model performance was slightly worse, with R-2 values between 0.27 and 0.40, MBE between -0.01 and 0.02, and rmse between 0.11 and 0.13. The model response to changes in soil water at these levels was sluggish, possibly because of, among other things, a lack of ability to model preferential downward water flow through cracks in the soil. The results of this study suggest that SHM can be used effectively to initialize 5-cm soil moisture values in numerical prediction models. At deeper soil levels, however, the relatively small R-2 values and negligible MBE suggest that the model may be better suited for initializing a regionally averaged soil moisture value rather than unique gridbox values. These results illustrate the difficulty in using point measurements to validate a hydrological model, especially deeper in the soil where moisture values are more dependent on soil properties (which can vary sharply over small distances) and are less dependent on recent rainfall. C1 NOAA, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73069 USA. Penn State Univ, University Pk, PA 16802 USA. S Dakota Sch Mines & Technol, Rapid City, SD USA. RP Crawford, TM (reprint author), NOAA, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, 1313 Halley Circle, Norman, OK 73069 USA. NR 33 TC 20 Z9 21 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD AUG PY 2000 VL 1 IS 4 BP 353 EP 363 DI 10.1175/1525-7541(2000)001<0353:UASHMT>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357VE UT WOS:000089520800004 ER PT J AU Lee, KS Rhee, YW Blackburn, DH Lawn, BR Chai, H AF Lee, KS Rhee, YW Blackburn, DH Lawn, BR Chai, H TI Cracking of brittle coatings adhesively bonded to substrates of unlike modulus SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SILICON-NITRIDE BILAYERS; CERAMIC COATINGS; MECHANICAL CHARACTERIZATION; CONTACT DAMAGE; INDENTATION; FRACTURE AB The role of elastic mismatch in determining critical conditions for indentation fracture in brittle coatings on substrates of unlike modulus was investigated. A model transparent trilayer system, consisting of a glass coating layer bonded to a thick substrate of different glass or polymer by a thin layer of epoxy adhesive, facilitated in situ observations of crack initiation and propagation. A tungsten carbide sphere was used to load the layer system. Abrasion flaws were introduced into the top and bottom glass coating surfaces to control the flaw populations and to predetermine the origins of fracture: cone cracks occurred at abraded top surfaces, radial cracks at abraded bottom surfaces, Analytical relations for the critical loads are presented for each crack system in terms of elastic modulus mismatch, indenter and coating dimensions, and material fracture parameters. Implications concerning materials selection for resistance to crack initiation are considered. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Tel Aviv Univ, Fac Engn, Dept Solid Mech Mat & Struct, IL-69978 Tel Aviv, Israel. RP Lee, KS (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 23 TC 18 Z9 18 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 AUG PY 2000 VL 15 IS 8 BP 1653 EP 1656 DI 10.1557/JMR.2000.0237 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 341KD UT WOS:000088588800002 ER PT J AU Khattra, JS Gresoviac, SJ Kent, ML Myers, MS Hedrick, RP Devlin, RH AF Khattra, JS Gresoviac, SJ Kent, ML Myers, MS Hedrick, RP Devlin, RH TI Molecular detection and phylogenetic placement of a microsporidian from English sole (Pleuronectes vetulus) affected by X-cell pseudotumors SO JOURNAL OF PARASITOLOGY LA English DT Article ID SALMON ONCORHYNCHUS-TSHAWYTSCHA; POSITION; DNA AB Flatfish tissue samples exhibiting X-cell pseudotumors were rested with a number of ribosomal DNA (rDNA) general primers in polymerase chain reactions (PCRs). Microsporidian primers resulted in the amplification of an rDNA fragment and molecular phylogenetic analysis indicated that although the organism did not relate closely with any current microsporidian genera, it was most similar to Nucleospora salmonis and branched within the Enterocytozoonidae. Re-examination of the original tissues used for DNA extractions revealed the presence of putative microsporidian spores in PCR-positive samples. These observations reiterate the highly sensitive diagnostic feature of PCR, allowing detection of organisms overlooked by conventional methods and demonstrate the occurrence of rare, coinfecting organisms. C1 Fisheries & Oceans Canada, W Vancouver Lab, W Vancouver, BC V7V 1N6, Canada. Univ Calif Davis, Sch Vet Med, Dept Med & Epidemiol, Davis, CA 95616 USA. Fisheries & Oceans Canada, Pacific Biol Stn, Nanaimo, BC V9R 5K6, Canada. Natl Marine Fisheries Serv, NOAA, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Khattra, JS (reprint author), Fisheries & Oceans Canada, W Vancouver Lab, 4160 Marine Dr, W Vancouver, BC V7V 1N6, Canada. NR 22 TC 13 Z9 13 U1 1 U2 2 PU AMER SOC PARASITOLOGISTS PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0022-3395 J9 J PARASITOL JI J. Parasitol. PD AUG PY 2000 VL 86 IS 4 BP 867 EP 871 DI 10.1645/0022-3395(2000)086[0867:MDAPPO]2.0.CO;2 PG 5 WC Parasitology SC Parasitology GA 344AW UT WOS:000088736300041 PM 10958476 ER PT J AU Cahn, JW AF Cahn, JW TI "Die Heterogenen Gleichgewichte (The Heterogeneous Equilibria)" a century later SO JOURNAL OF PHASE EQUILIBRIA LA English DT Article ID PHASE-EQUILIBRIA; MODEL AB Hendrik Willem Bakhuys Roozeboom's "Die Heterogenen Gleichgewichte vom Standpunkte der Phasenlehre" (The Heterogeneous Equilibria from the Points of View of the Phase Rule) was a monumental work that established and taught many fundamental principles that have since found unexpected uses in many fields.([1]) The principles were based on thermodynamic laws that will always be valid, but the development of some depended on nineteenth century concepts about the physical world. Bakhuys Roozeboom also shed light on many issues of his time that have remained with us throughout this century. This paper will explore the present status of some of these issues. In the nineteenth century, solids were thought to be inert and of definite chemical proportions. Bakhuys Roozeboom participated in the first discoveries that the composition of solids could vary continuously. The chemistry of the solid state is still undergoing rapid development. For example, equilibria of solids under nonhydrostatic stress are very different from what is seen for fluids under pressure, and defects in solids often play important parts,([2]) Surfaces are a pervasive presence in heterogeneous equilibria, whose effects were long ignored. Their effect on the equilibria of three-dimensional phases becomes more pronounced as the scale of subdivision by surfaces becomes smaller. Surfaces, as two-dimensional phases, have equilibria of their own, which can be described by another kind of geometrical thermodynamics. The theory of Van der Waals about the continuity between a liquid and its vapor was still new in Bakhuys Roozeboom's time.([3]) It gave an explanation for the critical point that can occur when these two phases become identical, and raised the hope that critical points would occur between other pairs of phases. The theory relied implicitly on the fact that the symmetry of a liquid is the same as that of a vapor. For pairs of phases with differing symmetries, the matter is more complex. A critical point is impossible when the symmetries of the phases are as different as that of a crystal and its melt. Although Bakhuys Roozeboom argued convincingly and correctly that there cannot be a critical point where an equilibrated liquid and a crystal become identical, the belief was slow to die. However, continuity at the interface is another matter. It is an important assumption of the phase field theory of the interface between a liquid and a crystal, which has many interesting and useful predictions. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Cahn, JW (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 31 TC 1 Z9 1 U1 0 U2 3 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1054-9714 J9 J PHASE EQUILIB JI J. Phase Equilib. PD AUG PY 2000 VL 21 IS 4 BP 327 EP 335 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 348UL UT WOS:000089004800005 ER PT J AU Huang, NE Shih, HH Shen, Z Long, SR Fan, KL AF Huang, NE Shih, HH Shen, Z Long, SR Fan, KL TI The ages of large amplitude coastal seiches on the Caribbean Coast of Puerto Rico SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID INTERNAL WAVES; HILBERT SPECTRUM; GENERATION; EXCITATION; SEA AB Using a process denoted here as the empirical mode decomposition and the Hilbert spectral analysis, the ages of the seiches on the Caribbean coast of Puerto Rico are determined from their dispersion characteristics with respect to time. The ages deduced from this method are less than a day; therefore, the seiches could be locally generated. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Lab Hydrospher Proc, Wallops Island, VA 23337 USA. CALTECH, Pasadena, CA 91125 USA. NOAA, Natl Ocean Serv, Silver Spring, MD USA. Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92717 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Observat Sci Branch,Lab Hydrospher Proc, Wallops Island, VA 23337 USA. Natl Taiwan Univ, Inst Oceanog, Taipei 10764, Taiwan. RP Long, SR (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Lab Hydrospher Proc, WFF Code 972,Bldg N-159,Room W-134, Wallops Island, VA 23337 USA. RI Long, Steven/D-7248-2012 NR 25 TC 31 Z9 44 U1 1 U2 3 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 AUG PY 2000 VL 30 IS 8 BP 2001 EP 2012 DI 10.1175/1520-0485(2000)030<2001:TAOLAC>2.0.CO;2 PG 12 WC Oceanography SC Oceanography GA 347DG UT WOS:000088911700012 ER PT J AU Gnanadesikan, A Hallberg, RW AF Gnanadesikan, A Hallberg, RW TI On the relationship of the Circumpolar Current to Southern Hemisphere winds in coarse-resolution ocean models SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GENERAL-CIRCULATION MODEL; LINEAR HOMOGENEOUS MODEL; MOMENTUM BALANCE; DRAKE PASSAGE; OBSCURANTIST PHYSICS; NUMERICAL-MODEL; FORM DRAG; WORLD OCEAN; TRANSPORT; CHANNEL AB The response of the Circumpolar Current to changing winds has been the subject of much debate. To date most theories of the current have tried to predict the transport using various forms of momentum balance. This paper argues that it is also important to consider thermodynamic as well as dynamic balances. Within large-scale general circulation models, increasing eastward winds within the Southern Ocean drive a northward Ekman Bur of light water, which in turn produces a deeper pycnocline and warmer deep water to the north of the Southern Ocean. This in turn results in much larger thermal wind shear across the Circumpolar Current. which, given relatively small near-bottom velocities, results in an increase in Antarctic Circumpolar Current (ACC) transport. The Ekman flux near the surface is closed by a deep return flow below the depths of the ridges. A simple model that illustrates this picture is presented in which the ACC depends most strongly on the winds at the northern and southern edges of the channel. The sensitivity of this result to the formulation of buoyancy forcing is illustrated using a second simple model. A number of global general circulation model runs are then presented with different wind stress patterns in the Southern Ocean. Within these runs, neither the mean wind stress in the latitudes of Drake Passage nor the wind stress curl at the northern edge of Drake Passage produces a prediction for the transport of the ACC. However, increasing the wind stress within the Southern Ocean does increase the ACC transport. C1 NOAA, GFDL, Princeton, NJ 08544 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Gnanadesikan, A (reprint author), NOAA, GFDL, 302 Sayre Hall,POB CN710, Princeton, NJ 08544 USA. RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 49 TC 93 Z9 95 U1 0 U2 2 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 AUG PY 2000 VL 30 IS 8 BP 2013 EP 2034 DI 10.1175/1520-0485(2000)030<2013:OTROTC>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA 347DG UT WOS:000088911700013 ER PT J AU Sadek, F Mohraz, B Riley, MA AF Sadek, F Mohraz, B Riley, MA TI Linear procedures for structures with velocity-dependent dampers SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article AB Passive energy dissipation devices are used to reduce the damage from earthquakes by absorbing a portion of the earthquake-induced energy in structures. Wide acceptance of these devices in structures will depend on the availability of simplified methods for their analysis and design. The objectives of this study are to (1) investigate the effect of increased viscous damping on the seismic response of structures; (2) assess the accuracy of the linear static and linear dynamic procedures recommended in the NEHRP Guidelines for the Seismic Rehabilitation of Buildings (FEMA 273) for design of structures with velocity-dependent passive energy dissipation devices; and (3) propose modifications to the current design procedures to improve their accuracy. Based on the analysis of single-degree-of-freedom structures subjected to a large number of earthquake records, the study identifies the following limitations of the FEMA 273 procedures: (1) The use of a constant reduction factor for the displacement response of short-period structures; and (2) the assumption of a harmonic response to compute the peak velocity as well as the story and base shears. In many cases, these assumptions result in nonconservative estimates of the peak response and base shear. Comparisons of the results using the methods proposed in this study and in FEMA 273 with time-history analyses for several single- and multi-degree-of-freedom structures indicate that the proposed procedures give more accurate results. C1 So Methodist Univ, Dallas, TX 75275 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sadek, F (reprint author), So Methodist Univ, Dallas, TX 75275 USA. NR 9 TC 21 Z9 21 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD AUG PY 2000 VL 126 IS 8 BP 887 EP 895 DI 10.1061/(ASCE)0733-9445(2000)126:8(887) PG 9 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA 337PF UT WOS:000088370300005 ER PT J AU Soler, T Fury, RJ AF Soler, T Fury, RJ TI GPS alignment surveys and meridian convergence SO JOURNAL OF SURVEYING ENGINEERING-ASCE LA English DT Article ID SYSTEM AB Since the advent of the Global positioning System (GPS), geodetic azimuths can be accurately computed by simple implementation of well-known 3D concepts. However, when GPS alignment surveys involving azimuths are designed in advance, and later observed and reduced (e.g., during kinematic GPS work), corrections due to the convergence of the meridians should be kept in mind and not ignored. In this study a practical algorithm was used to compare accurately determined "meridian convergence" against the classical formalism available in standard textbooks. Thr typical approximate formulation available in the open literature was round adequate for GPS engineering surveys such as airport runway profiles, alignment of power lines or conveyor belts, stake positioning in highway construction, etc. A practical GPS survey was used to corroborate the results. Finally, a new 3D alternative to computing meridian convergence, which is equivalent to the rigorous formalism, is presented. C1 NOAA, NOS, Nat Geodet Survey, Global Positioning Sys Branch, Silver Spring, MD 20910 USA. RP Soler, T (reprint author), NOAA, NOS, Nat Geodet Survey, Global Positioning Sys Branch, 1315 East West Hwy, Silver Spring, MD 20910 USA. RI Soler, Tomas/F-6386-2010 NR 13 TC 2 Z9 2 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9453 J9 J SURV ENG-ASCE JI J. Surv. Eng.-ASCE PD AUG PY 2000 VL 126 IS 3 BP 69 EP 82 DI 10.1061/(ASCE)0733-9453(2000)126:3(69) PG 14 WC Engineering, Civil SC Engineering GA 338XR UT WOS:000088449000001 ER PT J AU Yoon, KJ Wiederhorn, SM Luecke, WE AF Yoon, KJ Wiederhorn, SM Luecke, WE TI Comparison of tensile and compressive creep behavior in silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMICS; CARBIDE; ALLOYS AB The creep behavior of a commercial grade of Si3N4 was studied at 1350 degrees and 1400 degrees C. Stresses ranged from 10 to 200 MPa in tension and from 30 to 300 MPa in compression. In tension, the creep rate increased linearly with stress at low stresses and exponentially at high stresses. By contrast, the creep rate in compression increased linearly with stress over the entire stress range, Although compressive and tensile data exhibited an Arrhenius dependence on temperature, the activation energies for creep In tension, 715.3 +/- 22.9 kJ/mol, and compression, 489.2 +/- 62.0 kJ/mol, were trot the same. These differences in creep behavior suggests that mechanisms of creep in tension and compression are different. Creep in tension is controlled by the formation of cavities, The cavity volume fraction increased linearly with increased tensile creep strain with a slope of unity. A cavitation model of creep, developed for materials that contain a triple-junction network of second phase, rationalizes the observed creep behavior at high and low stresses. In compression, cavitation plays a less important role in the creep process, The volume fraction of cavities in compression was similar to 18% of that in tension at 1.8% axial strain and approached zero at strains <1%, The linear dependence of creep rate on applied stress is consistent with a model for compressive creep involving solution-precipitation of Si3N4. Although the tensile and compressive creep rates overlapped at the lowest stresses, cavity volume fraction measurements showed that solution-precipitation creep of Si3N4 did not contribute substantially to the tensile creep rate. Instead, cavitation creep dominated at high and low stresses. C1 Korea Res Inst Stand & Sci, Mat Evaluat Ctr, Taejon 305600, South Korea. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Yoon, KJ (reprint author), Korea Res Inst Stand & Sci, Mat Evaluat Ctr, Taejon 305600, South Korea. NR 25 TC 47 Z9 47 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2000 VL 83 IS 8 BP 2017 EP 2022 PG 6 WC Materials Science, Ceramics SC Materials Science GA 341ZR UT WOS:000088621300026 ER PT J AU MacDonald, AE Lee, JL Xie, Y AF MacDonald, AE Lee, JL Xie, Y TI The use of quasi-nonhydrostatic models for mesoscale weather prediction SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DIFFERENTIAL-EQUATIONS; TIME SCALES; MOUNTAIN; SYSTEMS; WAVES AB In recent years, there has been extensive study of the mathematical basis of weather prediction leading to a new system of continuous equations that are well posed, and a set of conditions that make discrete atmospheric and other models stable and potentially more accurate. In particular, the theory deals with initial boundary value problems that admit multiple timescales. Using this theory, a quasi-nonhydrostatic model called QNH was developed at NOAA's Forecast Systems Laboratory. The model is fully compressible and explicit in the vertical as well as the horizontal direction. It is characterized by a parameter, "alpha" (typically the square of the vertical to horizontal aspect ratio), which multiplies the hydrostatic terms in the vertical equation of motion. In this paper, the authors describe the theoretical basis for the use of these models in mesoscale weather prediction. It is shown that fur the mesoscale, the parameter has the effect of decreasing both the frequency and amplitude of the gravity wave perturbation response to small-scale impulses in forcing and to unbalanced initial conditions. This allows a modelar to choose a length scale below which gravity wave generation is suppressed. A weakness of the approach is that the hydrostatic adjustment process is slowed down. The analysis indicates that the parameter does not have an effect on the Rossby waves, the larger horizontal-scale gravity waves, nor on forced solutions such as those created by heating. The bounded derivative initialization is discussed. Since the speeds of the vertical acoustic waves are decreased, quasi-nonhydrostatic models can calculate the vertical equations explicitly and still meet the Courant-Friedrichs-Levy criteria. It is concluded that the unique characteristics of quasi-nonhydrostatic models may make them valuable in mesoscale weather prediction, particularly of clouds and precipitation. C1 NOAA, ERL, Forecast Syst Lab, Boulder, CO 80303 USA. RP MacDonald, AE (reprint author), NOAA, ERL, Forecast Syst Lab, R-E-FS,325 Broadway, Boulder, CO 80303 USA. RI Xie, Yuanfu/G-4413-2015; Lee, JIN-LUEN/G-5364-2015 NR 23 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 1 PY 2000 VL 57 IS 15 BP 2493 EP 2517 DI 10.1175/1520-0469(2000)057<2493:TUOQNM>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 342QD UT WOS:000088655900010 ER PT J AU Numaguti, A Hayashi, Y AF Numaguti, A Hayashi, Y TI Gravity-wave dynamics of the hierarchical structure of super cloud clusters SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID FREQUENCY TROPICAL WAVES; AQUA PLANET MODEL; WESTERN PACIFIC; INTRASEASONAL OSCILLATIONS; CUMULUS CONVECTION; UNITED MECHANISMS; TOGA COARE; CIRCULATION; GENERATION; ATMOSPHERE AB The hierarchical structures of eastward-moving tropical super cloud clusters (SCC) and embedded westward-moving quasi-periodic cloud clusters (QPCC) are successfully simulated by a simple longitude-height two-dimensional model with simple moist processes. The model results clearly show a life cycle of cloud activity. The cloud area starts as a low-level shallow cloud, develops into deep convection, becomes a top-heavy cloud, and decays. Gravity-wave packets are excited by the growth and decay of this cloud and propagate both eastward and westward. The westward-propagating gravity waves are coupled with cloud activity and form westward-moving QPCC. On the other hand, the eastward propagating waves are not immediately coupled with deep convective activity. A deep convective cloud develops only after the low and middle troposphere is sufficiently moistened and cooled. The quasi-periodic emergence of the new convective cloud to the east results in the eastward movement of the envelope of QPCC, forming an eastward-moving SCC. It is suggested that the excitation of gravity waves of two vertical modes by grow and decay of the heating with top-heavy vertical profile is essential to this hierarchical structure. Especially, the net upward parcel displacement due to the shallow gravity-wave cell have a important role in the generation of new QPCC. Although bath eastward-moving SCC and westward-moving SCC are possible in a non-rotating atmosphere with no external origins of east-west asymmetry, eastward-moving SCC can be selected under existence of some external asymmetry, such as the beta effect, mean zonal wind shear, or asymmetry of latent heat flux due to WISHE (wind-induced surface heat exchange) effect. C1 Univ Tokyo, Ctr Climate Syst Res, Tokyo, Japan. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. RP Numaguti, A (reprint author), Hokkaido Univ, Grad Sch Environm Earth Sci, N10W5, Sapporo, Hokkaido 0600810, Japan. EM numa@ees.hokudai.ac.jp NR 35 TC 9 Z9 9 U1 0 U2 0 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 AUG PY 2000 VL 78 IS 4 BP 301 EP 331 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 362CT UT WOS:000089761600001 ER PT J AU Hicks, RL Strand, IE AF Hicks, RL Strand, IE TI The extent of information: Its relevance for random utility models SO LAND ECONOMICS LA English DT Article ID CHOICE SET; RECREATION DEMAND; MARKET AB This paper examines the effect of the researcher's definition of a recreator's choice set on the parameter and welfare estimates from standard random utility models. Three choice set definitions are compared: choice sets based on all alternatives within the survey, those alternatives within a specified distance from the respondents home, and alternatives familiar to the individual. We show that parameter and welfare estimates are sensitive to the definition of the choice set. Welfare measures of site closures differ in varying ways depending on the familiarity level of the sites in question. (JEL Q26). C1 Univ Maryland, College Pk, MD 20742 USA. Natl Marine Fisheries Serv, Fisheries Stat & Econ Div, College Pk, MD USA. RP Hicks, RL (reprint author), Coll William & Mary, Dept Coastal & Ocean Policy, Williamsburg, VA 23187 USA. NR 21 TC 17 Z9 17 U1 1 U2 3 PU UNIV WISCONSIN PI MADISON PA SOCIAL SCIENCE BLDG, MADISON, WI 53706 USA SN 0023-7639 J9 LAND ECON JI Land Econ. PD AUG PY 2000 VL 76 IS 3 BP 374 EP 385 DI 10.2307/3147035 PG 12 WC Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA 362LJ UT WOS:000089779200004 ER PT J AU Mourtada, FA Soares, CG Seltzer, SM Lott, SH AF Mourtada, FA Soares, CG Seltzer, SM Lott, SH TI Dosimetry characterization of P-32 catheter-based vascular brachytherapy source wire SO MEDICAL PHYSICS LA English DT Article DE restenosis; brachytherapy; Monte Carlo; beta dosimetry; P-32 ID BALLOON ANGIOPLASTY; INTIMAL HYPERPLASIA; REDUCE RESTENOSIS; BETA-IRRADIATION; RADIATION; ASSAY; MODEL AB Dosimetry measurements and Monte Carlo simulations for a catheter-based P-32 endovascular brachytherapy source wire are described. The measured dose rates were obtained using both radiochromic dye film and an automated plastic scintillator. The investigated source has dimensions of 27 mm in length and 0.24 mm in diameter, and is encapsulated in NiTi. For the radiochromic film measurements, calibrated radiochromic dye film was irradiated at distances between 1 and 5 mm from the source axis in A-150 plastic, and read out with a high-resolution scanning densitometer. The depth-dose curve measured in A-150 is then converted to that in water using correction factors obtained from Monte Carlo calculations. For the scintillator system, direct measurements in water were acquired at distances between 1 and 6 mm from the center of the source, along the perpendicular bisector of the source axis. The scintillator was calibrated in terms of absorbed-dose rate in a reference beta-particle field at multiple depths. The measured dose rates obtained from the film and scintillator measurements were then normalized to the measured source activity, i.e., to convert the measured data to units of cGy/s/mCi. Theoretical dosimetry calculations of the catheter-based P-32 wire geometry were also obtained from Monte Carlo simulations using the Electron Gamma Shower code (EGS4), the Monte Carlo N-particle transport code (MCNP4B), and CYLTRAN from the integrated Tiger Series codes (ITS v.3) and found to be in good agreement. The results of both measurements and calculations are expressed as absorbed-dose rate in water per unit of contained activity (cGy/s/mCi). Comparisons indicate that the measured and calculated dosimetry are in good agreement (<10%) within the relevant treatment distances (1-5 mm). This work fully characterizes the radiation held around a novel P-32 beta brachytherapy source in water. The depth-dose curve can be used to calculate the dose to the vessel wall from a 27 mm 32P source wire centered within the vessel lumen. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)00108-5]. C1 Johns Hopkins Univ, Sch Med, Dept Radiol & Radiol Sci, Baltimore, MD 21205 USA. Natl Inst Stand & Technol, Div Ionizing Radiat, Gaithersburg, MD 20899 USA. Guidant Vasc Intervent, Houston, TX 77054 USA. RP Mourtada, FA (reprint author), Johns Hopkins Univ, Sch Med, Dept Radiol & Radiol Sci, Baltimore, MD 21205 USA. RI Grams, Michael/G-5197-2011 NR 27 TC 47 Z9 47 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD AUG PY 2000 VL 27 IS 8 BP 1770 EP 1776 DI 10.1118/1.1286551 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 347KM UT WOS:000088928300011 PM 10984223 ER PT J AU Taylor, PL Rodgers, JE Shobe, J AF Taylor, PL Rodgers, JE Shobe, J TI Scatter fractions from linear accelerators with x-ray energies from 6 to 24 MV (vol 26, pg 1442, 1999) SO MEDICAL PHYSICS LA English DT Correction C1 Georgetown Univ, Med Ctr, Dept Radiat Med, Washington, DC 20007 USA. Natl Inst Stand & Technol, Ionizing Radiat Phys Div, Gaithersburg, MD 20899 USA. RP Taylor, PL (reprint author), Georgetown Univ, Med Ctr, Dept Radiat Med, Washington, DC 20007 USA. NR 1 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD AUG PY 2000 VL 27 IS 8 BP 2000 EP 2000 DI 10.1118/1.1287649 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 347KM UT WOS:000088928300037 ER EF