FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Proctor, FM Shackleford, WP AF Proctor, FM Shackleford, WP BE Orban, PE TI Real-time operating system timing jitter and its impact on motor control SO SENSORS AND CONTROLS FOR INTELLIGENT MANUFACTURING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Controls for Intelligent Manufacturing II CY OCT 28, 2001 CL BOSTON, MA SP SPIE DE jitter; real-time operating system; task scheduling; stepper motor AB General-purpose microprocessors are increasingly being used for control applications due to their widespread availability and software support for non-control functions like networking and operator interfaces. Two classes of real-time operating systems (RTOS) exist for these systems. The traditional RTOS serves as the sole operating system, and provides all OS services. Examples' include ETS, LynxOS, QNX, Windows CE and VxWorks. RTOS extensions add real-time scheduling capabilities to non-real-time OSes, and provide minimal services needed for the time-critical portions of an application. Examples include RTAI and RTL for Linux, and HyperKernel, OnTime and RTX for Windows NT. Timing jitter is an issue in these systems, due to hardware effects such as bus locking, caches and pipelines, and software effects from mutual exclusion resource locks, non-preemtible critical sections, disabled interrupts, and multiple code paths in the scheduler. Jitter is typically on the order of a microsecond to a few tens of microseconds for hard real-time operating systems, and ranges from milliseconds to seconds in the worst case for soft real-time operating systems. The question of its significance on the performance of a controller arises. Naturally, the smaller the scheduling period required for a control task, the more significant is the impact of timing jitter. Aside from this intuitive relationship is the greater significance of timing on open-loop control, such as for stepper motors, than for closed-loop control, such as for servo motors. Techniques for measuring timing jitter are discussed, and comparisons between various platforms are presented. Techniques to reduce jitter or mitigate its effects are presented. The impact of jitter on stepper motor control is analyzed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Proctor, FM (reprint author), Natl Inst Stand & Technol, Bldg 220,Room B124, Gaithersburg, MD 20899 USA. NR 2 TC 7 Z9 8 U1 1 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4291-7 J9 P SOC PHOTO-OPT INS PY 2001 VL 4563 BP 10 EP 16 DI 10.1117/12.452653 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Manufacturing; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Engineering; Instruments & Instrumentation GA BT92V UT WOS:000174463300002 ER PT S AU Hefner, A Berning, D Blackburn, D Chapuy, C Bouche, S AF Hefner, A Berning, D Blackburn, D Chapuy, C Bouche, S GP IEEE IEEE IEEE TI A high-speed thermal imaging system for semiconductor device analysis SO SEVENTEENTH ANNUAL IEEE SEMICONDUCTOR THERMAL MEASUREMENT AND MANAGEMENT SYMPOSIUM, PROCEEDINGS 2001 SE PROCEEDINGS, IEEE SEMICONDUCTOR THERMAL MEASUREMENT AND MANAGEMENT SYMPOSIUM LA English DT Proceedings Paper CT 17th Annual IEEE Semiconductor Thermal Measurement and Management Symposium CY MAR 20-22, 2001 CL SAN JOSE, CA SP IEEE, Components, Package, & Mfr Technol Soc AB A new high-speed transient thermal imaging system is presented that provides the capability to measure the transient temperature distributions on the surface of a semiconductor chip with 1-mus time, and 15-mum spatial resolution. The system uses virtual instrument graphical user interface software that controls an infrared thermal microscope, translation stages, digitizing oscilloscope, and a device test fixture temperature controller. The computer interface consists of a front panel for viewing the temperature distribution and includes a movie play-back feature that enables viewing of the temperature distribution versus time. The computer user interface also has a sub-panel for emissivity mapping and calibration of the infrared detector. The utility of the system is demonstrated in this paper using a bipolar transistor hotspot current constriction process. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Hefner, A (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 3 TC 6 Z9 7 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1065-2221 BN 0-7803-6649-2 J9 P IEEE SEMICOND THER PY 2001 BP 43 EP 49 DI 10.1109/STHERM.2001.915143 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA BS03Z UT WOS:000168411800006 ER PT B AU Ripple, DC Strouse, GF Tew, WL AF Ripple, DC Strouse, GF Tew, WL GP IEEE IEEE IEEE IEEE TI The role of high-purity noble metals in precision thermometry SO SICON/01: ISA/IEEE SENSORS FOR INDUSTRY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 1st ISA/IEEE Sensors for Industry Conference CY NOV 05-07, 2001 CL ROSEMONT, IL SP Instrument, Syst & Automat Soc, IEEE Instrument & Measurement Soc ID TEMPERATURE AB A variety of alternate calibration schemes which approximate the ITS-90 are possible when using high-purity noble metals. The high purity of the sensor materials allows the use of correlations that exist between the measured properties at fixed point temperatures. The data from NIST Standard Reference Materials 1749 and 1750 serve to illustrate the degree to which such schemes may succeed using comparable material. The result is a variable cost versus accuracy tradeoff in calibration procedures that can be customized to the measurement needs of various industry sectors. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ripple, DC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6659-X PY 2001 BP 12 EP 17 DI 10.1109/SFICON.2001.968491 PG 6 WC Instruments & Instrumentation; Remote Sensing SC Instruments & Instrumentation; Remote Sensing GA BT68J UT WOS:000173723900003 ER PT B AU Gilsinn, JD Lee, K AF Gilsinn, JD Lee, K GP IEEE IEEE IEEE IEEE TI Wireless interfaces for IEEE 1451 sensor networks SO SICON/01: ISA/IEEE SENSORS FOR INDUSTRY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 1st ISA/IEEE Sensors for Industry Conference CY NOV 05-07, 2001 CL ROSEMONT, IL SP Instrument, Syst & Automat Soc, IEEE Instrument & Measurement Soc AB NIST started working with industry and the Institute Of Electrical and Electronics Engineers (IEEE) in the mid 90's to develop a standardized interface to network smart sensors. With the spread of wireless technology, more industries are looking to incorporate wireless communications into their products and manufacturing processes. This paper discusses the IEEE 1451 standard interface for smart sensors, emerging wireless communication technologies, and possible solutions for creating a wireless interface for the IEEE 1451 standard. C1 US Dept Commerce, Natl Inst Stand & Technol, Technol Admin, Washington, DC 20230 USA. RP Gilsinn, JD (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Technol Admin, Washington, DC 20230 USA. NR 9 TC 1 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6659-X PY 2001 BP 45 EP 50 DI 10.1109/SFICON.2001.968497 PG 6 WC Instruments & Instrumentation; Remote Sensing SC Instruments & Instrumentation; Remote Sensing GA BT68J UT WOS:000173723900009 ER PT B AU Richter, CA Vogel, EM Hodge, AM Hefner, AR AF Richter, CA Vogel, EM Hodge, AM Hefner, AR BE Tsoukalas, D Tsamis, C TI Differences between quantum-mechanical capacitance-voltage simulators SO SIMULATION OF SEMICONDUCTOR PROCESSES AND DEVICES 2001 LA English DT Proceedings Paper CT International Conference on Simulation of Semiconductor Processes and Devices (SISPAD 01) CY SEP 05-07, 2001 CL Athens, GREECE ID OXIDES AB We present an extensive benchmarking comparison of an ensemble of the most advanced quantum-mechanical (QM) capacitance-voltage (CV) simulators available. Quantitative differences in the accumulation capacitance of p-channel and n-channel devices as large as 20% are found in a systematic comparison. Some of the underlying physics and models that lead to the observed differences are described. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM Curt.Richter@NIST.gov RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 9 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, A-1201 VIENNA, AUSTRIA BN 3-211-83708-6 PY 2001 BP 340 EP 343 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BT40A UT WOS:000172900500077 ER PT S AU Tarrio, C Lucatorto, TB Grantham, S Squires, MB Arp, U Deng, L AF Tarrio, C Lucatorto, TB Grantham, S Squires, MB Arp, U Deng, L BE Tichenor, DA Folta, JA TI Upgrades to the NIST/DARPA EUV Reflectometry Facility SO SOFT X-RAY AND EUV IMAGING SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Soft X-Ray and EUV Imaging Systems II CY JUL 31-AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE extreme ultraviolet; metrology; reflectometry; lithography AB We have recently installed a new sample chamber at the NIST/DARPA EUV Reflectometry Facility at the National Institute of Standards and Technology. The chamber replaces a much smaller system on Beamline 7 at the Synchrotron Ultraviolet Radiation Facility that was commissioned almost ten years ago as a dedicated facility for the measurement of normal-incidence extreme ultraviolet optics used in lithography development, astronomy, and plasma physics. The previous measurement chamber was limited to optics less than 10 cm in diameter, and, thus, we were not able to measure many of the optics used in modern telescopes and extreme ultraviolet lithography steppers. The new chamber was designed to accommodate optics up to 36 cm in diameter and weighing up to 40 kg, and with modifications will be able to measure optics up to 50 cm in diameter. It has three translation and three rotation axes for the sample and two rotation axes for the detector, with an accuracy of better than 0.5 mm in translation and 0.04degrees in rotation. We will describe design considerations, performance of the positioning mechanisms, and initial reflectivity measurements of both curved and flat surfaces. C1 Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Tarrio, C (reprint author), Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. OI Arp, Uwe/0000-0002-6468-9455 NR 8 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4220-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4506 BP 32 EP 38 AR UNSP 4506-06 DI 10.1117/12.450961 PG 7 WC Optics; Physics, Applied; Imaging Science & Photographic Technology SC Optics; Physics; Imaging Science & Photographic Technology GA BU16D UT WOS:000175177600005 ER PT S AU Schaake, J Duan, QY Koren, V Hall, A AF Schaake, J Duan, QY Koren, V Hall, A BE Dolman, AJ Hall, AJ Kavvas, ML Oki, T Pomeroy, JW TI Toward improved parameter estimation of land surface hydrology models through the Model Parameter Estimation Experiment (MOPEX) SO SOIL-VEGETATION-ATMOSPHERE TRANSFER SCHEMES AND LARGE-SCALE HYDROLOGICAL MODELS SE IAHS PUBLICATION LA English DT Proceedings Paper CT International Symposium on Soil-Vegetation-Atmosphere Transfer Schemes and Large-Scale Hydrological Models CY JUL 18-27, 2001 CL MAASTRICHT, NETHERLANDS SP Int Assoc Hydrol Sci DE hydrological models; parameter estimation; model calibration; parameter regionalization; MOPEX ID BASIN AB A key issue in land surface modelling is to estimate model parameters that vary spatially and are unique to each computational element. An international Model Parameter Estimation Experiment (MOPEX) was established to develop techniques for the a priori estimation of the parameters used in land surface parameterization schemes of atmospheric models and in hydrological models. The major effort to achieve this goal is to assemble a large number of high quality historical hydrometeorological and river basin characteristics data sets for a wide range of intermediate-scale river basins (500-10 000 km(2)) throughout the world. Data sets from Phase I of MOPEX are available via the Internet. MOPEX Phase II activities will collect additional data from the USA as well as data for basins from other countries. During the next three years, the scientific community will use the available MOPEX data sets to estimate basin parameters and to relate them to basin characteristics. This paper presents the MOPEX science strategy, describes the MOPEX data sets, and illustrates the execution of MOPEX strategy with an example based on the Sacramento Soil Moisture Accounting model (SAC-SMA) used by US National Weather Service for river and flood forecasting. C1 Hydrol Lab Natl Weather Serv, Silver Spring, MD 20910 USA. RP Schaake, J (reprint author), Hydrol Lab Natl Weather Serv, 1325 East West Highway, Silver Spring, MD 20910 USA. NR 8 TC 6 Z9 6 U1 0 U2 1 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD OX10 8BB, ENGLAND SN 0144-7815 BN 1-901502-61-9 J9 IAHS-AISH P PY 2001 IS 270 BP 91 EP 97 PG 7 WC Engineering, Civil; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BT42X UT WOS:000172971900013 ER PT S AU Singer, HJ Heckman, GR Hirman, JW AF Singer, H. J. Heckman, G. R. Hirman, J. W. BE Song, P Singer, HJ Siscoe, GL TI Space Weather Forecasting: A Grand Challenge SO SPACE WEATHER SE Geophysical Monograph Series LA English DT Proceedings Paper CT Chapman Conference on Space Weather CY MAR 20-JUN 24, 2001 CL Clearwater, FL AB Space Environment Center (SEC) is the United States' official source of space weather alerts, warnings, and forecasts. Forecasts are used to support activities that are impacted by space weather such as electric power transmission, satellite operations, humans in space, navigation, and communication. This article presents a brief review of current space weather forecasting capabilities, and then focuses on the science, the models, the data, the new technologies, and the process for transitioning research into operations that is needed to meet the challenge to improve space weather forecasting in the new millennium. Forecasting critical parameters such as the interplanetary magnetic field at the magnetopause, and critical events such as coronal mass ejections are two examples of challenges to the research, observation, and modeling communities. Major improvements in space weather forecasting will be achieved when these, as well as other, challenges are met. The forecasting challenge is also discussed in the context of the goals of the US National Space Weather Program (NSWP) and other international activities. C1 [Singer, H. J.; Heckman, G. R.; Hirman, J. W.] NOAA, Space Environm Ctr, R SEC, Boulder, CO 80305 USA. RP Singer, HJ (reprint author), NOAA, Space Environm Ctr, R SEC, 325 Broadway, Boulder, CO 80305 USA. EM howard.singer@noaa.gov; howard.singer@noaa.gov NR 8 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 978-0-87590-984-4 J9 GEOPH MONOG SERIES PY 2001 VL 125 BP 23 EP 29 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BOP22 UT WOS:000277201400003 ER PT B AU Lunsford, C Haldorson, L Fujioka, JT Quinn, TJ AF Lunsford, C Haldorson, L Fujioka, JT Quinn, TJ BE Kruse, GH Bez, N Booth, A Dorn, MW Hills, S Lipcius, RN Pelletier, D Roy, C Smith, SJ Witherell, D TI Distribution patterns and survey design considerations of pacific ocean perch (Sebastes alutus) in the Gulf of Alaska SO SPATIAL PROCESSES AND MANAGEMENT OF MARINE POPULATIONS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT Symposium on Spatial Processes and Management of Marine Populations CY OCT 27-30, 1999 CL ANCHORAGE, AK SP Alaska Dept Fish & Game, N Pacific Fishery Management Council, US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Alaska Sea Grant Coll Program, Univ Alaska Fairbanks AB In the Gulf of Alaska, a stratified-random trawl survey has been conducted triennially since 1984 to obtain abundance estimates for major groundfish species. There is considerable uncertainty in the survey biomass estimates for Pacific ocean perch (Sebastes alutus) (POP). Using a geographic information system (GIS) and log-linear analyses, survey and commercial fishery data were analyzed to determine POP distribution patterns in the Gulf of Alaska (GOA). The survey and the fishery appear to encounter POP in the same areas throughout the GOA, and POP distribution does not appear to change temporally. Analysis of CPUE data indicates POP exhibit a tightly aggregated distribution pattern which is related to habitat type. The improvement of the survey design, or relative efficiency compared to a random estimate was 65%. Altering the allocation and stratification of the current design may improve the precision of POP biomass estimates but may be limited by the clustered distribution exhibited by POP in the GOA and the need to assess other species. Work is being conducted to evaluate the merits of adaptive cluster sampling for providing improved estimates for rockfish populations. C1 Natl Marine Fisheries Serv, Alaska Fishery Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Lunsford, C (reprint author), Natl Marine Fisheries Serv, Alaska Fishery Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. NR 29 TC 6 Z9 6 U1 0 U2 0 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-068-3 J9 LOW WAKE FI PY 2001 VL 17 BP 281 EP 302 PG 22 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA BU03H UT WOS:000174771600014 ER PT B AU Turk, TA AF Turk, TA BE Kruse, GH Bez, N Booth, A Dorn, MW Hills, S Lipcius, RN Pelletier, D Roy, C Smith, SJ Witherell, D TI Spatial distribution and selected habitat preferences of weathervane scallops (Patinopecten caurinus) in Alaska SO SPATIAL PROCESSES AND MANAGEMENT OF MARINE POPULATIONS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT Symposium on Spatial Processes and Management of Marine Populations CY OCT 27-30, 1999 CL ANCHORAGE, AK SP Alaska Dept Fish & Game, N Pacific Fishery Management Council, US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Alaska Sea Grant Coll Program, Univ Alaska Fairbanks ID EASTERN GEORGES BANK; SEA SCALLOP; GROWTH AB Over the past 30 years, the weathervane scallop (Patinopecten caurinus) fishery, located from the Oregon coast to the Bering Sea, has largely been passively managed by state agencies without adequate information on the abundance or ecology of the species. My objective was to obtain information on the life history, distribution, and ecology of weathervane scallops in order to promote effective management of the resource. Selected commercial logbook information from the 1993-1997 fishery was compiled, analyzed using ArcView((R)) GIS (geographic information system) and used to delineate and characterize scallop beds. In addition, scallop data were compared with sediment type data from U.S. Geological Survey (USGS) surveys. Average CPUE (catch per unit of effort) was highest on sand and clayey silt-to-silt substrates and lowest on bedrock. Depth did not appear to correlate with CPUE. These results suggest resource managers should consider sediment type as well as fishery effort when designing future scallop surveys. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Ctr, Seattle, WA 98112 USA. RP Turk, TA (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Ctr, Seattle, WA 98112 USA. NR 22 TC 2 Z9 2 U1 2 U2 3 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-068-3 J9 LOW WAKE FI PY 2001 VL 17 BP 463 EP 477 PG 15 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA BU03H UT WOS:000174771600024 ER PT B AU Garrison, LP AF Garrison, LP BE Kruse, GH Bez, N Booth, A Dorn, MW Hills, S Lipcius, RN Pelletier, D Roy, C Smith, SJ Witherell, D TI Spatial patterns in species composition in the northeast United States continental shelf fish community during 1966-1999 SO SPATIAL PROCESSES AND MANAGEMENT OF MARINE POPULATIONS SE Lowell Wakefield Fisheries Symposia Series LA English DT Proceedings Paper CT Symposium on Spatial Processes and Management of Marine Populations CY OCT 27-30, 1999 CL ANCHORAGE, AK SP Alaska Dept Fish & Game, N Pacific Fishery Management Council, US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Alaska Sea Grant Coll Program, Univ Alaska Fairbanks ID GEORGES BANK; ASSEMBLAGES; ECOSYSTEM; OVERLAP AB I evaluated spatial structure in the northeast United States continental shelf groundfish community based on a 30-year time series of bottom trawl survey data. Four major faunal regions were identified based on similarity in species composition. The faunal regions had consistent geographic boundaries across the time series. There were significant changes in species composition within faunal regions through time, reflecting changes in both species abundances and spatial patterns. Species that declined in abundance tended to contract their spatial range while those that increased tended to expand the total area covered by the population. However, the more general pattern in this community was a northward shift in spatial distribution observed in many exploited and unexploited species. The major changes in community structure and spatial distributions associated with both fishing pressure and climate variation have important implications for the trophic dynamics of this ecosystem. C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. RP Garrison, LP (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. EM Lance.Garrison@noaa.gov NR 21 TC 3 Z9 5 U1 0 U2 1 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-068-3 J9 LOW WAKE FI PY 2001 VL 17 BP 513 EP 537 PG 25 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA BU03H UT WOS:000174771600027 ER PT B AU Morgan, LE Botsford, LW AF Morgan, LE Botsford, LW BE Kruse, GH Bez, N Booth, A Dorn, MW Hills, S Lipcius, RN Pelletier, D Roy, C Smith, SJ Witherell, D TI Managing with reserves: Modeling uncertainty in larval dispersal for a sea urchin fishery SO SPATIAL PROCESSES AND MANAGEMENT OF MARINE POPULATIONS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT Symposium on Spatial Processes and Management of Marine Populations CY OCT 27-30, 1999 CL ANCHORAGE, AK SP Alaska Dept Fish & Game, N Pacific Fishery Management Council, US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Alaska Sea Grant Coll Program, Univ Alaska Fairbanks ID MARINE RESERVES; STRONGYLOCENTROTUS-FRANCISCANUS; NORTHERN CALIFORNIA; SPATIAL VARIABILITY; MANAGEMENT; RECRUITMENT; POPULATIONS; SETTLEMENT; TRANSPORT; ADULT AB The commercial fishery for the northern California red sea urchin, Strongylocentrotus franciscanus, began in 1985, peaked in 1989, and has declined steadily since that time. An alternative to traditional management is spatial management using no-take reserves that may improve the management of this and other fisheries. We formulated a size-structured metapopulation model with 24 patches and a dispersal matrix to address the key issue of larval linkages between reserve and fished patches. We explored four conceptual models of metapopulation connectivity including source-sink, limited distance, larval pool, and headlands dispersal models. These models indicated that the mode of dispersal led to potentially large differences in reserve performance. Larval pool models require little knowledge of spatial patterns in order to design an effective reserve network, while source-sink dynamics require a detailed understanding of larval dispersal if reserves are to be an effective means of fisheries management. Reserve networks can be optimized with knowledge of larval dispersal patterns; however, they are rarely known with certainty. A decision analysis used to evaluate alternative dispersal modes suggested a reserve system comprising approximately 25% of the total area can maintain catch in the red sea urchin fishery, buffering uncertainty in the pattern of larval replenishment and fishing mortality rate. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Tiburon, CA 94920 USA. RP Morgan, LE (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Tiburon, CA 94920 USA. NR 46 TC 6 Z9 6 U1 0 U2 2 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-068-3 J9 LOW WAKE FI PY 2001 VL 17 BP 667 EP 684 PG 18 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA BU03H UT WOS:000174771600036 ER PT S AU Leo, PJ Peach, G Whittingham, IB Woschnik, T Wenz, H Behmenburg, W AF Leo, PJ Peach, G Whittingham, IB Woschnik, T Wenz, H Behmenburg, W BE Seidel, J TI Broadening and shift of the Na Transition 3p P-2(1/2)-3d D-2(3/2) Perturbed by He SO SPECTRAL LINE SHAPES, VOL 11: 15TH ICSLS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 15th International Conference on Spectral Line Shapes CY JUL 10-14, 2000 CL BERLIN, GERMANY SP German Natl Meterol Inst ID LINES AB A comparison is made between the experimental broadening and shift constants for the sodium transition 3p(2)P(1/2) - 3d(2)D(3/2) perturbed by helium and corresponding quantum mechanical calculations. C1 NIST, Div Atom Phys, Gaithersburg, MD 20899 USA. RP Leo, PJ (reprint author), NIST, Div Atom Phys, Gaithersburg, MD 20899 USA. RI Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-991-2 J9 AIP CONF PROC PY 2001 VL 559 BP 319 EP 321 PG 3 WC Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical SC Physics GA BS20D UT WOS:000169065800073 ER PT B AU Kelleher, DE Martin, WC Wiese, WL Fuhr, JR Musgrove, A Olson, K Mohr, PJ Reader, J Sansonetti, JE Podobedova, L AF Kelleher, DE Martin, WC Wiese, WL Fuhr, JR Musgrove, A Olson, K Mohr, PJ Reader, J Sansonetti, JE Podobedova, L BE Ferland, G Savin, DW TI NIST databases on atomic spectra SO SPECTROSCOPIC CHALLENGES OF PHOTOIONIZED PLASMAS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Photoionized Plasmas 2000 Conference CY NOV 15-18, 2001 CL UNIV KENTUCKY, LEXINGTON, KY SP NASA Appl Informat Syst Res Program HO UNIV KENTUCKY AB A summary of the contents and features of the National Institute of Standards and Technology (NIST) Atomic Spectra Database (ASD) and other published and upcoming compilations and databases from NIST is presented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kelleher, DE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-085-4 J9 ASTR SOC P PY 2001 VL 247 BP 159 EP 160 PG 2 WC Astronomy & Astrophysics; Optics; Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Astronomy & Astrophysics; Optics; Physics; Spectroscopy GA BU54X UT WOS:000176291800015 ER PT B AU Powell, CJ Conny, JM Jablonski, A AF Powell, CJ Conny, JM Jablonski, A BE Baer, DR Clayton, CR Davis, GD Halada, GP TI Some issues in quantitative x-ray photoelectron Spectroscopy and auger-electron spectroscopy SO STATE-OF-THE ART APPLICATION OF SURFACE AND INTERFACE ANALYSIS METHODS TO ENVIRONMENTAL MATERIALS INTERACTIONS: IN HONOR OF JAMES E. CASTLE'S 65TH YEAR, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on State-of-the-Art Application of Surface and Interface Analysis Methods to Environmental Material Interaction held in Honor of James F Castle CY MAR 26-27, 2001 CL WASHINGTON, D.C. SP Electrochem Soc, Corros Div, ASTM Com E-42 Surface Analysis ID PEAK-PARAMETER ERRORS; STANDARD TEST DATA; MEAN FREE PATHS; ATTENUATION LENGTHS; ELASTIC-SCATTERING; 50-2000-EV RANGE; XPS; ENERGIES; AES; INTENSITIES AB We give an overview of two issues that are important in quantitative X-ray photoelectron spectroscopy (XPS) and Auger-electron spectroscopy (AES). First, we review the use of XPS standard test data (STD) that consist mainly of synthesized doublets. The STD were designed to test the reliability of peak energies and peak intensities obtained from fits to measured spectra containing overlapping components (i.e., that are often associated with different chemical states). The biases and random errors in peak positions can each be 0.1 eV or more when the doublet peak separation is less than 0.5 eV. In such cases, the median biases in relative peak intensities for the doublet components could be up to a factor of four, while the random errors could be up to factor of two. Second, we discuss the effects of elastic-electron scattering in measurements of overlayer-film thickness by AES or XPS. In such measurements, the effective attenuation length (EAL) should be used instead of the inelastic mean free path (IMFP). As an example, we present calculations of practical EALs for thin films of silicon dioxide on silicon for common XPS measurement conditions. For Mg and Al Kalpha x rays and photoelectron emission angles less than about 60degrees with respect to the surface normal, the average practical EALs are between 6.5% and 9.4% less than the corresponding IMFPs; the actual difference depends on the x-ray source, the SiO(2) thickness, and the XPS configuration. For larger emission angles, the practical EALs can vary appreciably with SiO(2) thickness and emission angle; in these circumstances, practical EALs should be determined for the specific measurement conditions. If XPS is performed with smaller x-ray energies (i.e., with synchrotron radiation), the practical EALs can be up to about 30% less than the IMFP and can differ for emission angles of 0degrees and 55degrees as found in recent experiments. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Powell, CJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 27 TC 0 Z9 0 U1 0 U2 2 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-311-3 J9 ELEC SOC S PY 2001 VL 2001 IS 5 BP 15 EP 45 PG 31 WC Chemistry, Analytical; Materials Science, Characterization & Testing; Spectroscopy SC Chemistry; Materials Science; Spectroscopy GA BX89S UT WOS:000186759900002 ER PT S AU Mulkens, E Roberts, J AF Mulkens, E Roberts, J BE Woods, AJ Bolas, MT Merritt, JO Benton, SA TI Effects of display geometry and pixel structure on stereo display usability SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Stereoscopic Displays and Virtual Reality Systems VIII CY JAN 22-25, 2001 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE stereo display measurement; stereo display standards C1 NIST, Gaithersburg, MD 20899 USA. RP Mulkens, E (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3975-4 J9 P SOC PHOTO-OPT INS PY 2001 VL 4297 BP 276 EP 289 DI 10.1117/12.430826 PG 14 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BS89M UT WOS:000171334300033 ER PT B AU Sardeshmukh, P Penland, C Newman, M AF Sardeshmukh, P Penland, C Newman, M BE Imkeller, P VonStorch, JS TI Rossby waves in a stochastically fluctuating medium SO STOCHASTIC CLIMATE MODELS SE PROGRESS IN PROBABILITY LA English DT Proceedings Paper CT Workshop on Stochastic Climate Models CY MAY 31-JUN 02, 1999 CL CHORIN, GERMANY ID DIFFERENTIAL-EQUATIONS AB It is well known that rapid fluctuations of the zonal mean wind speed can contribute significantly to the variability of planetary-scale atmospheric waves (Rossby waves). What seems to be less appreciated is that these same fluctuations can also contribute to the climatological mean wave pattern. In this study, the extent to which stochastic zonal wind fluctuations affect the mean and variance of the wave response to steady forcing is investigated in the context of a simple numerical model of the global atmosphere, i.e. a barotropic vorticity equation model. It is first shown that rapid variations of the zonal wind can justifiably be treated as stochastic. Then, the appropriate modifications to the barotropic vorticity equation are derived using the classical theory of stochastic differential equations. Finally, the effect of the stochastic fluctuations on the mean Rossby-wave response is illustrated in two qualitatively different cases. The first experiment considers stochastic fluctuations in the zonally-symmetric component of the wind, and it is shown that those fluctuations amount to a net damping of the Rossby wave. In the second experiment, random fluctuations in the frictional damping are considered, and are shown to have a net destabilizing influence. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Sardeshmukh, P (reprint author), NOAA, CIRES, Climate Diagnost Ctr, 325 Broadway, Boulder, CO 80303 USA. RI Newman, Matthew /F-8336-2010 OI Newman, Matthew /0000-0001-5348-2312 NR 13 TC 20 Z9 20 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND BN 3-7643-6520-X J9 PROG PROBAB PY 2001 VL 49 BP 369 EP 384 PG 16 WC Mathematics, Applied; Meteorology & Atmospheric Sciences; Statistics & Probability SC Mathematics; Meteorology & Atmospheric Sciences GA BS47H UT WOS:000169962700017 ER PT J AU Didion, DA Brown, JS AF Didion, DA Brown, JS TI Challenges in developing environmentally safe heat pumping systems SO STROJNISKI VESTNIK-JOURNAL OF MECHANICAL ENGINEERING LA English DT Article; Proceedings Paper CT ASME-ZSITS International Thermal Science Seminar CY JUN 11-14, 2000 CL BLED, SLOVENIA SP Amer Soc Mech Engineers, Assoc Mech Engineers & Technicians Slovenia, Int Ctr Heat & Mass Transfer, Int Inst Refrigerat, Commiss B1, Republic Slovenia Minist Sci & Technol, Danfoss Compressors dd, Gorenje dd, Krka, Pharmaceut Ind dd, Nucl Power Plant Krsko, Petrol, Slovene Oil Co dd, Trimo dd AB The advent of the global warming crisis has brought about a viewpoint, in many governments, that the halogen family of refrigerants should be replaced, in part or in toto, by the so-called natural refrigerants, For this proposal to be valid it is necessary to consider both the refrigerant's direct environmental impact and its life-long performance under field conditions. This is particularly true in the case of global warming because, for most applications, it is the heat pump's operating efficiency and its impact on the central power plant's emissions that is the dominating environmental factor. Any refrigerant must also meet a variety of other criteria that deal with durability, safety and costs. A simple comparison of basic fluid properties is conducted to indicate what system design considerations must be made if a refrigerant is to become an acceptable alternative. It is also reasoned that while computer models and laboratory prototypes are a necessary beginning, they are not sufficient to determine the true environmental impact of any system. Finally, the question is raised as to whether the refrigerant specification approach is the better path to an improved environment or if it is wiser to leave all options open for researchers and manufacturers to meet an environmental performance standard any way they choose. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Catholic Univ Amer, Dept Mech Engn, Washington, DC 20064 USA. RP Didion, DA (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RI Brown, J. Steven/F-9841-2011 OI Brown, J. Steven/0000-0003-4914-7778 NR 13 TC 2 Z9 2 U1 0 U2 0 PU ASSOC MECHANICAL ENGINEERS TECHNICIANS SLOVENIA PI LJUBLJANA PA PO BOX 197-IV, LJUBLJANA 61001, SLOVENIA SN 0039-2480 J9 STROJ VESTN-J MECH E JI Strojniski Vestn.-J. Mech. Eng. PY 2001 VL 47 IS 8 BP 356 EP 365 PG 10 WC Engineering, Mechanical SC Engineering GA 510YP UT WOS:000173235400003 ER PT J AU Simiu, E Heckert, NA Filliben, JJ Johnson, SK AF Simiu, E Heckert, NA Filliben, JJ Johnson, SK TI Extreme wind load estimates based on the Gumbel distribution of dynamic pressures: an assessment SO STRUCTURAL SAFETY LA English DT Article DE building technology; extreme value statistics; structural engineering; wind engineering; wind forces AB We present a contribution to the current debate on whether it is more appropriate to fit a Gumbel distribution to the time series of the extreme dynamic pressures (i.e. of the squares of the extreme wind speeds) than to fit an extreme value distribution to the time series of the extreme wind speeds themselves. It has been shown that the use of time series of the extreme dynamic pressures would be justified if the time series of the wind speed data taken at small intervals (e.g. 1 h) were, at least approximately, Rayleigh-distributed. We show that, according to sets of data we believe are typical, this is not the case. In addition, we show results of probability plot correlation coefficient (PPCC) analyses of 100 records of sample size 23 to 54, according to which the fit of reverse Weibull distributions to largest yearly wind speeds is considerably better than the fit of Gumbel distributions to the corresponding largest yearly dynamic pressures. We interpret the data and results presented in the paper as indicating that there is no convincing support to date for the hypothesis that the Gumbel distribution should be used as a model of extreme dynamic pressures. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NIST, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Simiu, E (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 8 TC 39 Z9 43 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-4730 J9 STRUCT SAF JI Struct. Saf. PY 2001 VL 23 IS 3 BP 221 EP 229 DI 10.1016/S0167-4730(01)00016-9 PG 9 WC Engineering, Civil SC Engineering GA 509MN UT WOS:000173151700003 ER PT S AU Germer, TA Nadal, ME AF Germer, TA Nadal, ME BE Gu, ZH Maradudin, AA TI Modeling the appearance of special effect pigment coatings SO SURFACE SCATTERING AND DIFFRACTION FOR ADVANCED METROLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Surface Scattering and Diffraction for Advanced Metrology CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE appearance; coatings; colorimetry; metallic; paint; pearlescent; polarization; scattering ID OUT-OF-PLANE; OPTICAL SCATTER INSTRUMENT; SUBSURFACE DEFECTS; DIELECTRIC FILM; POLARIZATION; ELLIPSOMETRY; SURFACE; SILICON; SPHERES AB Metallic and pearlescent coatings are becoming increasingly important in automotive, currency, and cosmetic applications. These coatings consist of metallic or dielectric platelets suspended in a binder, and are often applied between a pigmented basecoat, and a transparent topcoat. The scattering properties of these composite coatings vary depending upon the incident and viewing directions, as well as the wavelength. The complex nature of the scattering arises from the competition between multiple scattering sources: front surface reflection from the topcoat, reflection from the platelets, diffuse scattering from the pigmented undercoat, and scattering between platelets. The complex interplay between multiple scattering sources affects the ability to achieve quality control during the preparation of these coatings. In addition, the topcoat surface morphology, the properties of the pigmented basecoat, and the intrinsic properties, concentration, and angular distribution of the platelets influence the final appearance of the coating. In this paper, we will present models for light scattering from front surface facet reflection, subsurface flake reflection, and diffuse subsurface scattering. Experimental scattering measurements on pearlescent coatings show that the polarization can be well described in different geometry regimes by these different scattering sources. The models can be used to extract the slope distribution function of the flakes from the intensity data, but some aspects of the results behave inconsistently. Comparison is also made between experimental and calculated diffuse reflectance spectra. These results are intended to enable improved characterization of special effect coatings necessary for quality control and appearance modeling applications. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Germer, TA (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 21 TC 27 Z9 27 U1 3 U2 11 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4161-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4447 BP 77 EP 86 DI 10.1117/12.446721 PG 10 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BT41R UT WOS:000172924500009 ER PT J AU Pfeifer, L AF Pfeifer, L TI The bird yard Parliamentary Standard SO SURVEY REVIEW LA English DT Article AB This article presents a definitive determination of the thermal expansion and length at standard temperature (62 degreesF) of the Bird Yard (1760) Parliamentary Standard (P-2), legal standard of length of the British Empire 1825-1855, destroyed in the fire of the House of Parliament on 16 October 1834. C1 NOAA, Cheyenne, WY 82009 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU COMMONWEALTH ASSOC SURVEYING LAND ECONOMY, C A S L E PI BRISTOL PA UNIV WEST ENGLAND, C/O FACULTY BUILT ENVIRONMENT, FRENCHAY CAMPUS, COLDHARBOUR L, BRISTOL BS16 1QY, ENGLAND SN 0039-6265 J9 SURV REV JI Surv. Rev. PD JAN PY 2001 VL 36 IS 279 BP 12 EP 22 PG 11 WC Engineering, Civil; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA 389AD UT WOS:000166214600002 ER PT B AU Higgins, RW Leetmaa, A Kousky, VE AF Higgins, RW Leetmaa, A Kousky, VE GP AMS AMS TI The leading patterns of climate variability and winter weather extremes in the United States - Part 1: Temperature SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID EXTRATROPICAL CIRCULATION; ANNULAR MODES; OSCILLATION; TRENDS C1 NCEP, CPC, Camp Springs, MD 20746 USA. RP Higgins, RW (reprint author), NCEP, CPC, Rm 605,5200 Auth Road, Camp Springs, MD 20746 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 3 EP 10 PG 8 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900003 ER PT B AU Xue, Y Leetmaa, A AF Xue, Y Leetmaa, A GP AMS AMS TI A statistical forecast model for tropical SST, sea level and precipitation: Predictability of warm pool area SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID PREDICTION; ENSO; VARIABILITY; TIME C1 Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. RP Xue, Y (reprint author), Room 807 WWB,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 57 EP 64 PG 8 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900013 ER PT B AU Compo, GP Sardeshmukh, PD Penland, C AF Compo, GP Sardeshmukh, PD Penland, C GP AMS AMS TI Changes of subseasonal variability associated with El Nino SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID OSCILLATION; EVENTS C1 NOAA, CIRIS, Climate Diagnost Ctr, Boulder, CO 80309 USA. RP Compo, GP (reprint author), NOAA, CIRIS, Climate Diagnost Ctr, 325 Broadway,R-E-CDC1, Boulder, CO 80309 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 74 EP 81 PG 8 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900017 ER PT B AU McPhaden, MJ AF McPhaden, MJ GP AMS AMS TI Moored buoy observations for seasonal-to-interannual climate prediction SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP McPhaden, MJ (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI McPhaden, Michael/D-9799-2016 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 94 EP 94 PG 1 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900020 ER PT B AU Winkler, CR Newman, M Sardeshmukh, PD AF Winkler, CR Newman, M Sardeshmukh, PD GP AMS AMS TI An empirical-dynamical extended range forecast model incorporating tropical diabatic forcing SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Newman, M (reprint author), NOAA, CIRES, Climate Diagnost Ctr, Mail Code R-CDC,325 Broadway, Boulder, CO 80303 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 99 EP 102 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900022 ER PT B AU Chen, WY Kanamitsu, M AF Chen, WY Kanamitsu, M GP AMS AMS TI Simulation of seasonal to decadal variations by CPC's new climate model SO SYMPOSIUM ON CLIMATE VARIABILITY, THE OCEANS AND SOCIETAL IMPACTS LA English DT Proceedings Paper CT Symposium on Climate Variability, the Oceans and Societal Impacts CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 USA. RP Chen, WY (reprint author), NOAA, NWS, NCEP, Climate Predict Ctr, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 138 EP 144 PG 7 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BU98Y UT WOS:000177563900029 ER PT B AU Bodner, MJ Browning, PA Lupo, AR Berger, CL AF Bodner, MJ Browning, PA Lupo, AR Berger, CL GP AMS AMS TI A climatology of heavy snowfall events in Northwest Missouri : The synoptic and dynamic characteristics of heavy snowfall SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID CYCLONES C1 Natl Weather Serv, Forecast Off, Pleasant Hill, MO 64080 USA. RP Bodner, MJ (reprint author), Natl Weather Serv, Forecast Off, 1803 N 7 Highway, Pleasant Hill, MO 64080 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 1 EP 5 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600001 ER PT B AU Manikin, GS Rogers, E AF Manikin, GS Rogers, E GP AMS AMS TI NCEP short-range model guidance for the 24-26 January 2000 East Coast winter storm SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NCEP EMC, Mesoscale Modeling Branch, Camp Springs, MD 20746 USA. RP Manikin, GS (reprint author), NCEP EMC, Mesoscale Modeling Branch, Room 204,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 6 EP 7 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600002 ER PT B AU White, AB Ralph, FM Neiman, PJ Kingsmill, DE Persson, PG AF White, AB Ralph, FM Neiman, PJ Kingsmill, DE Persson, PG GP AMS AMS TI Process partitioning of rainfall enhanced by coastal orography SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID RADAR; BAND C1 NOAA, ETL, R ET 7, Boulder, CO 80303 USA. RP White, AB (reprint author), NOAA, ETL, R ET 7, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 8 EP 11 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600003 ER PT B AU Wolyn, P AF Wolyn, P GP AMS AMS TI Case study and mesoscale modeling of the 28 April to 1 May 1999 heavy rain event over southeast Colorado SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Natl Weather Serv, Pueblo, CO 81001 USA. RP Wolyn, P (reprint author), NOAA, Natl Weather Serv, 3 Eaton Way, Pueblo, CO 81001 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 17 EP 21 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600006 ER PT B AU Janjic, Z DiMego, G AF Janjic, Z DiMego, G GP AMS AMS TI Effects of mountain representation and nonhydrostatic dynamics in a case of orographic precipitation SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID COORDINATE; MODEL; SCHEMES C1 NCEP, EMC, Camp Springs, MD 20746 USA. RP Janjic, Z (reprint author), NCEP, EMC, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 24 EP 28 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600008 ER PT B AU Neiman, PJ Ralph, FM White, AB Kingsmill, DA Persson, POG Gottas, D AF Neiman, PJ Ralph, FM White, AB Kingsmill, DA Persson, POG Gottas, D GP AMS AMS TI Orographic precipitation enhancement in the coastal mountains of California during The Caljet Field Experiment SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Neiman, PJ (reprint author), NOAA, Environm Technol Lab, Mail Code R-ET7,325 Broadway, Boulder, CO 80303 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 33 EP 37 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600010 ER PT B AU Torgerson, KL AF Torgerson, KL GP AMS AMS TI An analysis of significant WSR-88D precipitation underestimation over the Palmer Divide: 28 April to 1 May 1999 heavy rain event SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, Pueblo, CO 81001 USA. RP Torgerson, KL (reprint author), Natl Weather Serv, 3 Eaton Way, Pueblo, CO 81001 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 51 EP 55 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600014 ER PT B AU Rogers, E Manikin, G AF Rogers, E Manikin, G GP AMS AMS TI Forecast experiments for the 24-26 January 2000 East Coast storm using the NCEP ETA model SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NCEP, NOAA, NWS, Camp Springs, MD 20746 USA. RP Rogers, E (reprint author), NCEP, NOAA, NWS, W-NP22,Room 207, Camp Springs, MD 20746 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 56 EP 56 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600015 ER PT B AU Gourley, JJ Zhang, J Maddox, RA Calvert, CM Howard, KW AF Gourley, JJ Zhang, J Maddox, RA Calvert, CM Howard, KW GP AMS AMS TI A real-time precipitation monitoring algorithm quantitative precipitation estimation and segregation using multiple sensors (QPE SUMS) SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID PROFILE C1 Natl Severe Storms Lab, NOAA, Norman, OK 73069 USA. RP Gourley, JJ (reprint author), Natl Severe Storms Lab, NOAA, 1313 Halley Circle, Norman, OK 73069 USA. NR 4 TC 11 Z9 11 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 57 EP 60 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600016 ER PT B AU Tracton, MS Jun, D AF Tracton, MS Jun, D GP AMS AMS TI Application of the NCEP/EMC short range ensemble forecast system (SREF) to predicting extreme precipitation events SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NCEP EMC, Camp Springs, MD 20746 USA. RP Tracton, MS (reprint author), NCEP EMC, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 64 EP 65 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600018 ER PT B AU Grumm, RH Hart, R AF Grumm, RH Hart, R GP AMS AMS TI Anticipating heavy rainfall: Forecast aspects SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, State Coll, PA 16803 USA. RP Grumm, RH (reprint author), 227 W Beaver Ave, State Coll, PA 16803 USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 66 EP 70 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600019 ER PT B AU McDonald, BE Graziano, TM AF McDonald, BE Graziano, TM GP AMS AMS TI The national precipitation verifcation unit (NPVU): Operational implementation SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID MODEL C1 NOAA, NWS, NCEP, HPC, Camp Springs, MD USA. RP McDonald, BE (reprint author), NOAA, NWS, NCEP, HPC, Camp Springs, MD USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 71 EP 74 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600020 ER PT B AU Loughe, AF Henderson, JK Mahoney, JL Tollerud, E AF Loughe, AF Henderson, JK Mahoney, JL Tollerud, E GP AMS AMS TI A verification approach suitable for assessing the quality of model-based precipitation forecasts during extreme precipitation events SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, OAR, FSL AD, Boulder, CO 80305 USA. RP Loughe, AF (reprint author), NOAA, OAR, FSL AD, R-FS5,325 Broadway, Boulder, CO 80305 USA. RI Henderson, Judy/B-4902-2016 NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 77 EP 81 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600022 ER PT B AU Zhu, Y Toth, Z AF Zhu, Y Toth, Z GP AMS AMS TI Extreme weather events and their probabilistic prediction by the NCEP ensemble forecast system SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, NCEP, Environm Modeling Ctr, Washington, DC 20233 USA. RP Toth, Z (reprint author), NOAA, NCEP, Environm Modeling Ctr, Washington, DC 20233 USA. EM Zoltan.Toth@noaa.gov RI Toth, Zoltan/I-6624-2015 OI Toth, Zoltan/0000-0002-9635-9194 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 82 EP 85 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600023 ER PT B AU Carter, GM Graziano, TM AF Carter, GM Graziano, TM GP AMS AMS TI Restructuring the national weather service quantitative precipitation forecast process SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Natl Weather Serv, Eastern Reg Headquarters, Bohemia, NY 11716 USA. RP Carter, GM (reprint author), NOAA, Natl Weather Serv, Eastern Reg Headquarters, 630 Johnson Ave, Bohemia, NY 11716 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 86 EP 90 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600024 ER PT B AU Hoke, JE Reynolds, DW AF Hoke, JE Reynolds, DW GP AMS AMS TI The hydrometeorological prediction center restructuring its products and services for the 21(ST) century SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. RP Hoke, JE (reprint author), Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 91 EP 95 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600025 ER PT B AU Junker, NW AF Junker, NW GP AMS AMS TI Challenges facing the operational quantitative precipitation forecaster when predicting heavy to extreme events SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID FLOOD C1 Hydrometeorol Predict Ctr, NWS, NCEP, Camp Springs, MD USA. RP Junker, NW (reprint author), Hydrometeorol Predict Ctr, NWS, NCEP, Camp Springs, MD USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 107 EP 110 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600029 ER PT B AU Kelsch, M AF Kelsch, M GP AMS AMS TI The relationship between intense, short-duration precipitation and flash floods SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID HEAVY RAINFALL EVENTS C1 UCAR, COMET, Boulder, CO 80307 USA. RP Kelsch, M (reprint author), UCAR, COMET, POB 3000, Boulder, CO 80307 USA. NR 18 TC 1 Z9 1 U1 2 U2 2 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 124 EP 128 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600033 ER PT B AU Julian, LT Vogel, JL AF Julian, LT Vogel, JL GP AMS AMS TI Extreme precipitation frequency in the Semiarid Southwest SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. RP Julian, LT (reprint author), NOAA, Natl Weather Serv, Off Hydrol, 1325 East West Highway, Silver Spring, MD 20910 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 133 EP 136 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600035 ER PT B AU Marroquin, A Caracena, F Tollerud, EI AF Marroquin, A Caracena, F Tollerud, EI GP AMS AMS TI Potential vorticity streamers and their role in the development of mesoscale convective systems, Part III: Numerical weather simulations SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, OAR, FSL R, Boulder, CO 80305 USA. RP Marroquin, A (reprint author), NOAA, OAR, FSL R, 325 Broadway,FS1, Boulder, CO 80305 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 151 EP 154 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600040 ER PT B AU Blaha, RA AF Blaha, RA GP AMS AMS TI October 1998 extreme rains over South Central Texas SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, New Braunfels, TX 78130 USA. RP Blaha, RA (reprint author), 2090 Airport Rd, New Braunfels, TX 78130 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 157 EP 161 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600042 ER PT B AU Douglas, MW Pena, M Ordinola, N Flores, L Boustead, J AF Douglas, MW Pena, M Ordinola, N Flores, L Boustead, J GP AMS AMS TI Synoptic and spatial variability of the rainfall along the northern Peruvian coast during the 1997-8 El Nino event SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, NSSL, Norman, OK 73069 USA. RP Douglas, MW (reprint author), NOAA, NSSL, 1313 Halley Circle, Norman, OK 73069 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 170 EP 173 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600045 ER PT B AU Glass, FH Gagan, JP Moore, JT AF Glass, FH Gagan, JP Moore, JT GP AMS AMS TI The extreme east-central Missouri flash flood of 6-7 May 2000 SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, Natl Weather Serv, St Charles, MO 63304 USA. RP Glass, FH (reprint author), NOAA, Natl Weather Serv, 12 Res Pk Dr, St Charles, MO 63304 USA. NR 14 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 174 EP 179 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600046 ER PT B AU Koch, SE Mitchem, J AF Koch, SE Mitchem, J GP AMS AMS TI The role of dual cold fronts aloft in a major tornado and flash flooding event SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID SQUALL LINE; PRECIPITATION C1 NOAA, OAR, FSL, Boulder, CO 80303 USA. RP Koch, SE (reprint author), NOAA, OAR, FSL, 325 Broadway,R-FS1, Boulder, CO 80303 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 180 EP 184 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600047 ER PT B AU Davis, RS AF Davis, RS GP AMS AMS TI An AMBER playback of the Kansas City, Missouri flash flood of 05 October 1998 SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, Moon Twp, PA 15108 USA. RP Davis, RS (reprint author), Natl Weather Serv, 192 Shafer Rd, Moon Twp, PA 15108 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 213 EP 216 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600055 ER PT B AU Anderson, DM Berg, WK Bates, JJ AF Anderson, DM Berg, WK Bates, JJ GP AMS AMS TI Satellite observations of pacific moisture surges associated with the North American monsoon SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID SOUTHWESTERN UNITED-STATES; MARITIME TROPICAL AIR; CALIFORNIA; GULF C1 NOAA, ETL, Boulder, CO 80303 USA. RP Anderson, DM (reprint author), NOAA, ETL, 325 Broadway R-ET1A, Boulder, CO 80303 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 217 EP 220 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600056 ER PT B AU Cox, GM Arthur, AT Slayter, D Kuhnert, N AF Cox, GM Arthur, AT Slayter, D Kuhnert, N GP AMS AMS TI National basin delineation and flash flood database creation SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Cox, GM (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 221 EP 224 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600057 ER PT B AU Breidenbach, JP Seo, DJ Tilles, P Pham, C AF Breidenbach, JP Seo, DJ Tilles, P Pham, C GP AMS AMS TI Seasonal variation in multi-radar coverage for WSR-88D precipitation estimation in a mountainous region SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NWS Off Hydrol, Silver Spring, MD 20910 USA. RP Breidenbach, JP (reprint author), NWS Off Hydrol, 1325 East West Hwy, Silver Spring, MD 20910 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 225 EP 229 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600058 ER PT B AU Arthur, AT Howard, KW AF Arthur, AT Howard, KW GP AMS AMS TI Evaluation of the Areal Mean Basin estimated rainfall (AMBER) flash flood algorithm at the Tulsa, OK and Sterling, VA NWSFOS SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Arthur, AT (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 230 EP 233 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600059 ER PT B AU Falkovich, A Lord, S Treadon, R AF Falkovich, A Lord, S Treadon, R GP AMS AMS TI A new methodology of rainfall retrievals from indirect measurements. SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID CLOUD C1 NCEP, EMC, WWB, Camp Springs, MD 20746 USA. RP Falkovich, A (reprint author), NCEP, EMC, WWB, Room 209,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 234 EP 235 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600060 ER PT B AU Bright, DR Mullen, SL Maddox, RA AF Bright, DR Mullen, SL Maddox, RA GP AMS AMS TI Short range mesoscale ensemble forecasts of precipitation over the southwest United States during the summer convective season SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, Tucson, AZ 85719 USA. RP Bright, DR (reprint author), Natl Weather Serv, Suite 304,520 N Pk Ave, Tucson, AZ 85719 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 244 EP 247 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600063 ER PT B AU Marks, FD AF Marks, FD GP AMS AMS TI Quantitative precipitation forecasting in hurricanes: Issues and opportunities SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID TROPICAL CYCLONES; RADAR C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Marks, FD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 293 EP 296 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600077 ER PT B AU Scofield, RA DeMaria, M del Alfaro, RM AF Scofield, RA DeMaria, M del Alfaro, RM GP AMS AMS TI Space - Based rainfall capabilities in hurricanes offshore and inland SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID PRECIPITATION C1 NOAA, Sci Ctr, NESDIS, ORA,Hydrol Team, Camp Springs, MD 20746 USA. RP Scofield, RA (reprint author), NOAA, Sci Ctr, NESDIS, ORA,Hydrol Team, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI DeMaria, Mark/F-5583-2010 NR 20 TC 5 Z9 5 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 297 EP 301 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600078 ER PT B AU Ward, JD AF Ward, JD GP AMS AMS TI Extreme rains in South Texas associated with tropical Storm Charley (1998) SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, New Braunfels, TX 78130 USA. RP Ward, JD (reprint author), 2090 Airport Rd, New Braufeis, TX 78130 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 310 EP 313 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600082 ER PT B AU MacCracken, RF Thiaw, WM AF MacCracken, RF Thiaw, WM GP AMS AMS TI Circulation patterns and rainfall associated with the Feb-Mar 2000 Mozambique floods SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 CPC, NOAA, NWS, NCEP, Camp Springs, MD 20746 USA. RP MacCracken, RF (reprint author), CPC, NOAA, NWS, NCEP, Camp Springs, MD 20746 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 336 EP 339 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600090 ER PT B AU DeMaria, M Tuleya, RE AF DeMaria, M Tuleya, RE GP AMS AMS TI Evaluation of quantitative precipitation forecasts from the GFDL hurricane model SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Colorado State Univ, RAMMT, NESDIS, NOAA, Ft Collins, CO 80523 USA. RP DeMaria, M (reprint author), Colorado State Univ, RAMMT, NESDIS, NOAA, W Laporte Ave, Ft Collins, CO 80523 USA. RI DeMaria, Mark/F-5583-2010 NR 5 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 340 EP 343 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600091 ER PT B AU Kuligowski, RJ Ba, MB AF Kuligowski, RJ Ba, MB GP AMS AMS TI A self-calibrating blended satellite algorithm for estimating heavy precipitation SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NESDIS, NOAA, Off Res & Applicat, Camp Springs, MD USA. RP Kuligowski, RJ (reprint author), Kuligowski 5200 Auth Rd,WWB 601, Camp Springs, MD 20746 USA. RI Kuligowski, Robert/C-6981-2009 OI Kuligowski, Robert/0000-0002-6909-2252 NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 348 EP 349 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600093 ER PT B AU Cope, AM AF Cope, AM GP AMS AMS TI Radar-derived rainfall estimates for hurricane Floyd over New Jersey SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc ID WSR-88D; REFLECTIVITY; EVENTS C1 Natl Weather Serv, Mt Holly, NJ 08060 USA. RP Cope, AM (reprint author), Natl Weather Serv, 732 Woodlane Rd, Mt Holly, NJ 08060 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 352 EP 356 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600095 ER PT B AU Lushine, JB AF Lushine, JB GP AMS AMS TI Improving public response to hurricane flooding SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 NOAA, NWS, WFO Miami, Miami, FL 33165 USA. RP Lushine, JB (reprint author), NOAA, NWS, WFO Miami, 11691 SW 17th St, Miami, FL 33165 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 371 EP 372 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600100 ER PT B AU Pfost, RL AF Pfost, RL GP AMS AMS TI Basic landfalling tropical cyclone quantitative precipitation forecasting SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, Weather Forecast Off, Miami, FL 33165 USA. RP Pfost, RL (reprint author), Natl Weather Serv, Weather Forecast Off, 11691 SW 17th St, Miami, FL 33165 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 373 EP 377 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600101 ER PT B AU Sharp, DW Spratt, SM AF Sharp, DW Spratt, SM GP AMS AMS TI Graphically depicting threat assessment information for flood situations in East Central Florida SO SYMPOSIUM ON PRECIPITATION EXTREMES: PREDICTION, IMPACTS, AND RESPONSES LA English DT Proceedings Paper CT Symposium on Precipitation Extremes - Prediction, Impacts and Responses CY JAN 14-18, 2001 CL ALBUQUERQUE, NM SP Amer Meteorol Soc C1 Natl Weather Serv, MLB, Melbourne, FL 32935 USA. RP Sharp, DW (reprint author), Natl Weather Serv, MLB, 421 Croton Rd, Melbourne, FL 32935 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2001 BP 378 EP 380 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BV03A UT WOS:000177651600102 ER PT J AU Lewis, JM Raeder, KD Errico, RM AF Lewis, JM Raeder, KD Errico, RM TI Vapor flux associated with return flow over the Gulf of Mexico: a sensitivity study using adjoint modeling SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID GENERAL-CIRCULATION MODELS; MESOSCALE MODEL; OF-MEXICO; PARAMETERIZATION; GUFMEX AB The moisture flux associated with a return-now event in the Gulf of Mexico is studied with the aid of a regional forecast model and its adjoint. The adjoint model allows us to determine the derivatives of some aspect of the model output (a scalar, J) with respect to elements of the control vector (initial and boundary conditions). We choose J to be the northward moisture flux through a vertical cross section in the northwestern corner of the Gulf at the time when the moisture surge in the US is a maximum. The sensitivities (delJ) are used in conjunction with a set of optimal perturbations to estimate the impact of each of the perturbations on the moisture nux. The perturbations are chosen to have the structure of the sensitivities (making them optimal as described in the text), with magnitudes based on the (assumed) uncertainties in the model's initial and boundary conditions. The linear impact estimate is simply the projection of the perturbation onto the sensitivity fields. In complementary fashion, we introduce perturbations into the nonlinear forecast model and decompose the actual impact on J into thermodynamic and dynamic components, in order to better understand the nature of the sensitivity. From this numerical experiment we conclude the following. J is more sensitive to the temperature field than to the other prognostic variables, roughly by a factor of 3 or 4, based on the optimal perturbations used here. The sensitivity to each of the 3-D prognostic variables peaks in the lower atmosphere near 85 kPa. The sensitivity of J to the sea surface temperature (T-s, a fixed boundary condition) increases with forecast length. More than 30 h before the verification time, the impact of an optimal perturbation to T-s is comparable to the impact of an optimal perturbation to the whole 3-D air temperature field. The zones of sensitivity to the T-s are intimately tied to the trajectories of low-level air which terminate at the cross section. The impact of an optimal perturbation to the topography along the Sierra Madre Oriental mountains is comparable to the impact of optimal perturbations in each of the 3-D prognostic variables (except T). C1 Natl Ctr Atmospher Res, Boulder, CO 80305 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. RP Raeder, KD (reprint author), Natl Ctr Atmospher Res, Boulder, CO 80305 USA. NR 25 TC 13 Z9 13 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD JAN PY 2001 VL 53 IS 1 BP 74 EP 93 DI 10.1034/j.1600-0870.2001.01108.x PG 20 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 398ZH UT WOS:000166786000005 ER PT S AU Gibson, CE Yoon, HW Tsai, BK Johnson, BC Saunders, RD AF Gibson, CE Yoon, HW Tsai, BK Johnson, BC Saunders, RD BE Rozlosnik, AE Dinwiddie, RB TI Non-contact thermometry in the Optical Technology Division at NIST SO THERMOSENSE XXIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thermosense XXIII Conference CY APR 16-19, 2001 CL ORLANDO, FL SP SPIE DE blackbody; calibration; ITS-90; non-contact thermometry; radiation thermometer ID CALIBRATIONS; TEMPERATURE; FACILITY AB The Optical Technology Division (OTD) at the National Institute of Standards and Technology (NIST) maintains the thermodynamic temperature scale above the silver freezing point using spectral radiance ratios according to the International Temperature Scale of 1990 (ITS-90). Radiance temperature calibration services are performed in the OTD, and NIST's calibration services support industry, government agencies, national standards laboratories, pyrometer and blackbody manufacturers, universities, and U.S. military service calibration laboratories. In addition, the OTD also offers a four day Short Course on Temperature Measurement by Radiation Thermometry every year that extensively covers many aspects of radiation thermometry. Routine intercomparisons of the thermodynamic temperature scale are done with other national measurement laboratories for international verification of the accuracy of the issued calibrations. We describe research into alternatives to the ITS-90 - the use of absolute detector standards to directly measure the temperature of a high temperature blackbody. C1 Natl Inst Stand & Technol, Opt Tech Div, Gaithersburg, MD 20899 USA. RP Gibson, CE (reprint author), Natl Inst Stand & Technol, Opt Tech Div, Gaithersburg, MD 20899 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4055-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4360 BP 333 EP 341 DI 10.1117/12.421011 PG 9 WC Thermodynamics; Instruments & Instrumentation; Optics SC Thermodynamics; Instruments & Instrumentation; Optics GA BS34B UT WOS:000169530500039 ER PT S AU Tsai, BK Widmann, JF Bundy, M Hill, SM AF Tsai, BK Widmann, JF Bundy, M Hill, SM BE Rozlosnik, AE Dinwiddie, RB TI Characterization of an infrared spectrograph for non-contact thermometry applications using a sodium heat pipe blackbody SO THERMOSENSE XXIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thermosense XXIII Conference CY APR 16-19, 2001 CL ORLANDO, FL SP SPIE DE blackbody; calibration; infrared imaging; non-contact thermometry; radiation thermometer; sodium heat pipe blackbody; spectral radiance; spectrograph; temperature ID TEMPERATURE AB A two-dimensional imaging spectrograph, developed for non-intrusive temperature measurements in flames, has been characterized using a pressure-controlled sodium heat pipe blackbody (Na-HPBB). The spectrograph contains a two-dimensional PtSi CCD array and provides spatial information in one dimension and spectral information in the other dimension. The usable range of the spectrograph, which images a line approximately 35 mm in length, covers the region from 2.5 mum to 5.0 mum Using the stable and uniform Na-HPBB, the spectrograph was calibrated for absolute spectral radiance by employing Planck's Law. These measurements show that the spectrograph uniformity is within 0.26 % (k = 2), and provide calibration constants that can be applied to future measurements. The results presented here will enable the spectrograph to be used to measure the emission characteristics of high temperature surfaces, gases, and particles, and as a transfer detector to calibrate other secondary sources. C1 NIST, Opt Tech Div, Gaithersburg, MD 20899 USA. RP Tsai, BK (reprint author), NIST, Opt Tech Div, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4055-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4360 BP 438 EP 446 DI 10.1117/12.421022 PG 9 WC Thermodynamics; Instruments & Instrumentation; Optics SC Thermodynamics; Instruments & Instrumentation; Optics GA BS34B UT WOS:000169530500050 ER PT J AU Kruzic, LM Scarnecchia, DL Roper, BB AF Kruzic, LM Scarnecchia, DL Roper, BB TI Comparison of midsummer survival and growth of age-0 hatchery coho salmon held in pools and riffles SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SOUTHEAST ALASKA STREAM; ONCORHYNCHUS-KISUTCH; HABITAT USE; STEELHEAD; COVER; RESPONSES; PREDATORS; DENSITY; CHINOOK; OREGON AB Habitat use studies have shown that juvenile coho salmon Oncorhynchus kisutch select pools over riffles. However, stream alterations have caused pool habitat to be lost or degraded throughout the Pacific Northwest. This study compared the growth and survival of age-0 coho salmon in riffles and pools in four streams in the South Umpqua River basin, Oregon. Hatchery coho salmon were stocked in block-netted riffles and pools. At the end of the study, the fish were recovered in order to measure their growth and survival in each habitat type. The survival of coho salmon was significantly higher (P < 0.01) in pools (67%) than in riffles (27%). This variation in survival was related primarily to water depth. The growth of coho salmon did not differ significantly (P > 0.05) between pools and riffles. The condition factor of the coho salmon was significantly (P < 0.05) lower at the end of the experiment but did not differ between fish in pools and riffles (P > 0.05). The results of this study suggest that land management activities that reduce pool habitat may also reduce juvenile coho salmon survival or rearing capacity in small streams. C1 Univ Idaho, Dept Fish & Wildlife Resources, Moscow, ID 83844 USA. US Forest Serv, Tiller Ranger Dist, Tiller, OR USA. RP Kruzic, LM (reprint author), Natl Marine Fisheries Serv, 525 NE Oregon St,Suite 510, Portland, OR 97232 USA. RI Roper, Brett/F-2891-2010 NR 37 TC 9 Z9 11 U1 2 U2 10 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 JAN PY 2001 VL 130 IS 1 BP 147 EP 154 DI 10.1577/1548-8659(2001)130<0147:COMSAG>2.0.CO;2 PG 8 WC Fisheries SC Fisheries GA 430BM UT WOS:000168553700013 ER PT B AU Mindek, RB Whitenton, EP Evans, CJ AF Mindek, RB Whitenton, EP Evans, CJ GP NAMRI/SME NAMRI/SME TI Visualization of grit interactions during the ductile to brittle polishing transition SO TRANSACTIONS OF THE NORTH AMERICAN MANUFACTURING RESEARCH INSTITUTION OF SME, VOL XXIX, 2001 LA English DT Proceedings Paper CT 29th North American Manufacturing Research Conference (NAMRC XXIX) CY MAY 22-25, 2001 CL GAINESVILLE, FL SP Soc Mfg Engineers, N Amer Mfg Res Inst ID ELASTIC-PLASTIC INDENTATION AB Dual strobe and single strobe once per revolution imaging techniques are employed on the Rapidly Renewable Lap (RRL) to study the ductile to brittle transition observed during the polishing of silicon and calcium fluoride. Analysis of video images during polishing, optical microscopy of the lapped surfaces and scanning electron microscopy (SEM) of the lapping film after polishing suggest the observed step increase in material removal rate with diamond size is due to an increase beyond the critical grit penetration depth necessary for crack initiation, the ductile to brittle transition commonly observed in ceramic and glass materials. A model derived for lateral crack extension in ceramics is applied to the brittle material removal regime here and found to agree with the experimental data. An explanation for apparent shifts in the ductile to brittle transition during lapping of ductile materials using lapping films of various compliances is also discussed. C1 NIST, Mfg Metrol Div, Mfg Engn Lab, Gaithersburg, MD 20899 USA. RP NIST, Mfg Metrol Div, Mfg Engn Lab, Gaithersburg, MD 20899 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SOC MANUFACTURING ENGINEERS PI DEARBORN PA ONE SME DR, PO BOX 930, DEARBORN, MI 48128 USA BN 0-87263-600-3 PY 2001 BP 213 EP 220 PG 8 WC Engineering, Manufacturing; Engineering, Mechanical; Metallurgy & Metallurgical Engineering SC Engineering; Metallurgy & Metallurgical Engineering GA BV60L UT WOS:000179483900029 ER PT J AU Zhang, XH Gates, RS Anders, S Hsu, SM AF Zhang, XH Gates, RS Anders, S Hsu, SM TI An accelerated wear test method to evaluate lubricant thin films on magnetic hard disks SO TRIBOLOGY LETTERS LA English DT Article DE magnetic hard disks; lubrication; lubricant; monolayer; Z-Dol; durability ID RECORDING DISKS AB A high speed ball-on-inclined-plane test method has been developed to evaluate the lubrication effectiveness of Z-Dol on magnetic hard disks. The test evaluates the combined durability of the lubricant film and the carbon overcoat under sliding conditions. A polished ruby (Al2O3) ball without suspension is used to simulate the head material. The ball slides over an inclined (at an angle of 0.055 degrees +/- 0.005 degrees) section of the disk surface at 2.0 m/s linear velocity, The load is controlled by the geometric interference of the preloaded ball and the inclined plane. The contact forces are sampled periodically at 2 rpm and the frictional coefficients calculated. Repeated sliding between the ball and the disk sample leads to an increase in friction approaching that of the unlubricated case, Post test analysis using atomic force microscopy (AFM) suggests that the increase in friction is due to the loss of lubricant effectiveness of the lubricant and the wear of the carbon overcoat. X-ray photoemission microscopy (PEEM) results suggest progressive oxidation of Z-Dol as one of the degradation mechanisms leading to wear. The durability of the lubricating thin films is defined by the number of cycles to failure. Test repeatability is about 10%, depending on lubricant, film thickness, and surface roughness. The test cart be used to evaluate different lubricant chemistries as well as different carbon overcoats. Compared to other pin-on-disk tests and step loading ball-on-disk methods, this test introduces two additional factors: high speed impact and wear acceleration by the inclined angle. The high speed impact simulates potential thermal stresses associated with head-disk contact. With an inclined angle, the load increases evenly for each contact cycle, hence simulates the ability of the lubricant layer to react to dynamic loads. The test is intended as a basic research tool to measure the fundamental resistance of the lubricant layer to resist repeated high speed contacts. C1 Univ Maryland, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Zhang, XH (reprint author), Univ Maryland, College Pk, MD 20742 USA. RI Raoux, Simone/G-3920-2016 NR 11 TC 17 Z9 18 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2001 VL 11 IS 1 BP 15 EP 21 DI 10.1023/A:1016677321278 PG 7 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 466VV UT WOS:000170667600003 ER PT J AU McGuiggan, PM AF McGuiggan, PM TI The boundary lubrication properties of model esters SO TRIBOLOGY LETTERS LA English DT Article DE lubrication; friction; ester; surface forces apparatus; monolayer ID SURFACES; FILMS; MECHANISMS; ADHESION; LIQUID; FORCES AB The friction of three chemically distinct esters was measured in order to determine how molecular architecture influences friction. The friction coefficients mu of mica surfaces separated by a thin film (<2 nm) of -chlorodecyl benzoate, w-chlorodecyl pentafluoro benzoate, and omega -chlorodecyl perfluoro hexanoate were measured to be 0.15 +/- 0.015, 0.13 +/- 0.012, and 0.12 +/- 0.02, respectively. The friction coefficients for the esters are lower than the previously measured friction coefficients of simple hydrocarbon liquids such as n-tetradecane (mu = 0.8), but are comparable to the friction coefficients of surfactant monolayer coated surfaces (mu = 0.001-0.2). The results suggest that the ester molecules adsorb onto the mica surface with the (phenyl or hexyl) carbonyl next to the surface and the hydrocarbon tail pointing away from the surface. Hence, the friction is controlled by die packing density and properties of the hydrocarbon tail. Changes in the chemistry and structure of the carboxylic acid portion of the ester only give rise to small changes in the friction coefficient. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP McGuiggan, PM (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI McGuiggan, Patricia/A-3379-2010 NR 22 TC 2 Z9 2 U1 0 U2 5 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2001 VL 11 IS 1 BP 49 EP 53 DI 10.1023/A:1016669812240 PG 5 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 466VV UT WOS:000170667600007 ER PT S AU Chism, W Diebold, A Canterbury, J Richter, C AF Chism, W Diebold, A Canterbury, J Richter, C BE Heyns, M Mertens, P Meuris, M TI Characterization and production metrology of thin transistor gate dielectric films SO ULTRA CLEAN PROCESSING OF SILICON SURFACES 2000 SE SOLID STATE PHENOMENA LA English DT Article; Proceedings Paper CT 5th International Symposium on Ultra Clean Processing of Silicon Surfaces (UCPSS 2000) CY SEP 18-20, 2000 CL OOSTENDE, BELGIUM SP Akrion, Arch Chem, Ashland Chem, ATMI, EKC Technol Ltd, GeMeTeC, Horiba Europe, IMEC, IN USA Inc, Infineon Technol, KLA Tencor, Mallinckrodt, Merck KgA, Metron Technol, Millipore, MSP, Pall Europe, Philips Analyt, PMT Benelux, SEMI, Semitool, Sonosys, SOPRA, Tokyo Elektron Europe, ASM Int, IEEE, SCP Global Technol, Wacker Siltron DE dispersion models; ellipsometry; gate dielectrics ID SILICON; OXYNITRIDES AB We report use of spectroscopic ellipsometry (SE) to meet thickness and material composition characterization requirements for current and future production gate dielectrics. We determine optical dispersion for zirconium dioxide high k dielectric, material composition at an interface beneath the zirconium dioxide, and discuss related issues. We also report the development of optical models which extract nitrogen content in thin oxynitride gates. C1 Int Sematech Inc, Austin, TX 78741 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Chism, W (reprint author), Int Sematech Inc, 2706 Montopolis Dr, Austin, TX 78741 USA. NR 8 TC 5 Z9 5 U1 0 U2 0 PU SCITEC PUBLICATIONS LTD PI UETIKON-ZUERICH PA BRANDRAIN 6, CH-8707 UETIKON-ZUERICH, SWITZERLAND SN 1012-0394 BN 3-908450-57-8 J9 SOL ST PHEN PY 2001 VL 76-77 BP 177 EP 180 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA BS04V UT WOS:000168449500043 ER PT S AU Cundiff, ST Shacklette, JM Lorenz, VO AF Cundiff, ST Shacklette, JM Lorenz, VO BE Jiang, HX Tsen, KT Song, JJ TI Interaction effects in optically dense materials SO ULTRAFAST PHENOMENA IN SEMICONDUCTORS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultrafast Phenomena in Semiconductors V CY JAN 25-26, 2001 CL SAN JOSE, CA SP SPIE DE transient four-wave-mixing; ultrafast spectroscopy; optically dense; Lorentz local field; semiconductors; potassium ID BAND-GAP RENORMALIZATION; SEMICONDUCTOR QUANTUM-WELLS; LORENTZ LOCAL-FIELD; SELECTIVE REFLECTION; LINE-SHAPE; BULK GAAS; SPECTROSCOPY; EXCITATION; TRANSITIONS; RELAXATION AB The properties of optically dense materials are influenced by interactions between elementary optical excitations (oscillators). Since such interactions are absent in the dilute limit, the resulting properties are unique to optically dense materials. While linear optical experiments can probe these effects, for example the Lorentz-Lorenz resonance shift, they are often more apparent in nonlinear experiments that are sensitive to coherence. Direct gap semiconductors are typically optically dense close to the fundamental gap and have been extensively studied using ultrafast coherent spectroscopy over the last ten years. However, their coherent optical properties are very complex because of many-body interactions among the extended excitations (electron-hole pairs or excitons). Dense atomic vapors have also been studied, but typically using frequency domain techniques. We present the results of using ultrafast techniques to study both semiconductors and dense atomic vapors. This reveals the similarities and differences of the two systems, yielding insight into the characteristics of each individually. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP Cundiff, ST (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Cundiff, Steven/B-4974-2009 OI Cundiff, Steven/0000-0002-7119-5197 NR 31 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3958-4 J9 P SOC PHOTO-OPT INS PY 2001 VL 4280 BP 138 EP 148 DI 10.1117/12.424728 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BS36Q UT WOS:000169642000017 ER PT S AU Jacoff, A Messina, E Evans, J AF Jacoff, A Messina, E Evans, J BE Gerhart, GR Shoemaker, CM TI Reference test courses for autonomous mobile robots SO UNMANNED GROUND VEHICLE TECHNOLOGY III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology III CY APR 16-17, 2001 CL ORLANDO, FL SP SPIE DE performance metrics; autonomous robots; mobile robots; urban search and rescue AB One approach to measuring the performance of intelligent systems is to develop standardized or reproducible tests. These tests may be in a simulated environment or in a physical test course. The National Institute of Standards and Technology has developed a test course for evaluating the performance of mobile autonomous robots operating in an urban search and rescue mission. The test course is designed to simulate a collapsed building structure at various levels of fidelity. The course will be used in robotic competitions, such as the American Association for Artificial Intelligence (AAAI) Mobile Robot Competition and the RoboCup Rescue. Designed to be repeatable and highly reconfigurable, the test course challenges a robot's cognitive capabilities such as perception, knowledge representation, planning, autonomy and collaboration. The goal of the test course is to help define useful performance metrics for autonomous mobile robots which, if widely accepted, could accelerate development of advanced robotic capabilities by promoting the re-use of algorithms and system components. The course may also serve as a prototype for further development of performance testing environments which enable robot developers and purchasers to objectively evaluate robots for a particular application. In this paper we discuss performance metrics for autonomous mobile robots, the use of representative urban search and rescue scenarios as a challenge domain, and the design criteria for the test course. C1 NIST, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Jacoff, A (reprint author), NIST, Intelligent Syst Div, 100 Bur Dr,MS 8230, Gaithersburg, MD 20899 USA. OI Messina, Elena/0000-0002-1727-9357 NR 3 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4059-0 J9 P SOC PHOTO-OPT INS PY 2001 VL 4364 BP 341 EP 348 DI 10.1117/12.439994 PG 8 WC Computer Science, Artificial Intelligence; Robotics; Transportation Science & Technology SC Computer Science; Robotics; Transportation GA BT28L UT WOS:000172533400035 ER PT J AU Herst, AN Epelboim, J Steinman, RM AF Herst, AN Epelboim, J Steinman, RM TI Temporal coordination of the human head and eye during a natural sequential tapping task SO VISION RESEARCH LA English DT Article DE saccade; head movement; eye movement; head/eye coordination; gaze-shift ID LOOKING TASKS; GAZE SHIFTS; 2 KINDS; DISTRACTER TASK; ARM MOVEMENTS; TARGETS; SACCADES AB The 'natural' temporal coordination of head and eye was examined as four subjects tapped a sequence of targets arranged in 3D on a worktable in front of them. The head started to move before the eye 48% of the time. Both the head and eye started to move 'simultaneously' (within 8 ms of each other) 37% of the time. The eye started to move before the eye only 15% of the time. Gaze-shifts required to perform the tapping task were relatively large, 68% of them were between 27degrees and 57degrees. Gaze-shifts were symmetrical. There were almost as many lefts as rights. Very little inter- or intra-subject variability was observed. These results were not expected on the basis of prior studies of head/eye coordination performed under less natural conditions. They also were not expected given the results of two rather similar, relatively natural, prior experiments. We conclude that more observations under natural conditions will have to be made before we understand why, when and how human beings coordinate head and eyes as they perform everyday tasks in the work-a-day world.(C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Dept Psychol, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Herst, AN (reprint author), Univ Maryland, Dept Psychol, College Pk, MD 20742 USA. NR 33 TC 16 Z9 17 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-6989 J9 VISION RES JI Vision Res. PY 2001 VL 41 IS 25-26 BP 3307 EP 3318 DI 10.1016/S0042-6989(01)00158-4 PG 12 WC Neurosciences; Ophthalmology SC Neurosciences & Neurology; Ophthalmology GA 508KM UT WOS:000173087300009 PM 11718775 ER PT S AU Hall, TA AF Hall, TA BE Mouchtaris, P TI Objective speech quality measures for Internet telephony SO VOICE OVER IP (VOIP) TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Voice Over IP (VOIP) Technology CY AUG 21, 2001 CL DENVER, CO SP SPIE, Colorado Photon Ind Assoc DE speech quality; Internet telephony; voice over IP; network metrology AB Measuring voice quality for telephony is not a new problem. However, packet-switched, best-effort networks such as the Internet present significant new challenges for the delivery of real-time voice traffic. Unlike the circuit-switched PSTN, Internet protocol (IP) networks guarantee neither sufficient bandwidth for the voice traffic nor a constant, minimal delay. Dropped packets and varying delays introduce distortions not found in traditional telephony. In addition, if a low bitrate codec is used in voice over IP (VoIP) to achieve a high compression ratio, the original waveform can be significantly distorted. These new potential sources of signal distortion present significant challenges for objectively measuring speech quality. Measurement techniques designed for the PSTN may not perform well in VoIP environments. Our objective is to find a speech quality metric that accurately predicts subjective human perception under the conditions present in VoIP systems. To do this, we compared three types of measures: perceptually weighted distortion measures such as enhanced modified Bark spectral distance (EMBSD) and measuring normalizing blocks (MNB), word-error rates of continuous speech recognizers, and the ITU E-model. We tested the performance of these measures under conditions typical of a VoIP system. We found that the E-model had the highest correlation with mean opinion scores (MOS). The E-model is well-suited for online monitoring because it does not use the original (undistorted) signal to compute its quality metric and because it is computationally simple. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hall, TA (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,STOP 8920, Gaithersburg, MD 20899 USA. NR 9 TC 11 Z9 11 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4246-1 J9 P SOC PHOTO-OPT INS PY 2001 VL 4522 BP 128 EP 136 DI 10.1117/12.434293 PG 9 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BT21U UT WOS:000172292700014 ER PT J AU Reish, DJ Oshida, PS Mearns, AJ Ginn, TC Buchman, M AF Reish, Donald J. Oshida, Philip S. Mearns, Alan J. Ginn, Thomas C. Buchman, Michael TI EFFECTS OF POLLUTION ON MARINE ORGANISMS SO WATER ENVIRONMENT RESEARCH LA English DT Article C1 [Reish, Donald J.] Calif State Univ Long Beach, Dept Biol Sci, Long Beach, CA 90840 USA. [Oshida, Philip S.] US EPA, Washington, DC 20460 USA. [Mearns, Alan J.; Buchman, Michael] NOAA, Seattle, WA USA. [Ginn, Thomas C.] Exponent Environm Grp, Bellevue, WA USA. RP Reish, DJ (reprint author), Calif State Univ Long Beach, Dept Biol Sci, Long Beach, CA 90840 USA. NR 221 TC 0 Z9 0 U1 1 U2 5 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 USA SN 1061-4303 EI 1554-7531 J9 WATER ENVIRON RES JI Water Environ. Res. PY 2001 VL 73 IS 5 BP 1581 EP 1657 DI 10.2175/106143001X144519 PG 77 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA V19HR UT WOS:000208064000034 ER PT J AU Roebber, PJ Eise, J AF Roebber, PJ Eise, J TI The 21 June 1997 flood: Storm-scale simulations and implications for operational forecasting SO WEATHER AND FORECASTING LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; MODEL; RESOLUTION; SKILL; MM5 AB On 20-21 June 1997, a convective outbreak in Nebraska, Iowa, Illinois, and Wisconsin resulted in two fatalities, eight injuries, and approximately $104 million in damage. The majority of the damage ($92 million) was the result of flooding in southeastern Wisconsin owing to nearly 250 mm of rain produced by training convection and to a lesser extent the passage of a persistent, elongated convective system. The flood event is analyzed and storm-scale (5- and 1.67-km grid spacing) resolution model simulations at 0-24-, 12-36-, and 24-48-h ranges are produced to study the evolution and predictability of the rainfall. Synoptic conditions corresponded closely to the mesohigh pattern frequently associated with heavy rainfall events. Despite the recognition by National Weather Service forecasters of the potential for heavy rainfall, uncertainty concerning event magnitude and affected areas, exacerbated by poor operational model guidance, resulted in a failure to issue flash flood watches prior to the onset of flooding. Simulations of the event using 5- km grid spacing show that short-range forecasts (0-24 h) are able to suggest focused precipitation in southeastern Wisconsin. Initiation of the convection is tied to lift at the leading edge of a low-level jet (LLJ), with a focus along a weak frontogenetic boundary. A rapid loss of predictability at the 12-36- and 24-48-h ranges results in part from poorer representations of the LLJ. Increased resolution (1.67-km grid spacing) is necessary to capture the magnitude of the event. The increased resolution led to little change in available moisture or lift, but substantial increases in precipitation efficiency, arising from the capability to resolve the details of convective organization in an aggregate, time-averaged sense. With 1.67-km grid spacing, the probability of detection (false alarm ratio) for critical precipitation thresholds of 25, 50, 75, and 125 mm in the heavy rainfall region are 0.79 (0.01), 0.60 (0.21), 0.51 (0.23), and 0.36 (0.32), respectively. Precipitation forecast skill as measured by the Kuiper skill score for these same thresholds is 0.30, 0.36, 0.39, and 0.33. However, on a county warning area basis for flash flooding, these same forecasts yield probability of detection (false alarm ratio) of 0.71 (0.55). The results of this study suggest that the consistent use of storm-scale model output in conjunction with observations in such events will likely lead to improved forecasts and greater forecast value, although significant constraints related to real-world application of such models and procedures would still remain. In order to firmly establish these points, it is necessary to analyze a number of such cases within an operational context. C1 Univ Wisconsin, Dept Math Sci, Atmospher Sci Grp, Milwaukee, WI 53211 USA. NOAA, Natl Weather Serv, Sullivan, WI USA. RP Roebber, PJ (reprint author), Univ Wisconsin, Dept Math Sci, Atmospher Sci Grp, 3200 N Cramer Ave, Milwaukee, WI 53211 USA. NR 26 TC 17 Z9 17 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. PY 2001 VL 16 IS 2 BP 197 EP 218 DI 10.1175/1520-0434(2001)016<0197:TJFSSS>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 425GY UT WOS:000168283900001 ER PT J AU DeMaria, M Knaff, JA Connell, BH AF DeMaria, M Knaff, JA Connell, BH TI A tropical cyclone genesis parameter for the Tropical Atlantic SO WEATHER AND FORECASTING LA English DT Article ID EL-NINO; CYCLOGENESIS; ATMOSPHERE; MECHANISMS; INTENSITY AB A parameter to evaluate the potential for tropical cyclone formation (genesis) in the North Atlantic between Africa and the Caribbean islands is developed. Climatologically, this region is the source of about 40% of the Atlantic basin tropical cyclones but roughly 60% of the major hurricanes. The genesis parameter is the product of appropriately scaled 5-day running mean vertical shear, vertical instability, and midlevel moisture variables. The instability and shear variables are calculated from operational NCEP analyses, and the midlevel moisture variable is determined from cloud-cleared GOES water vapor imagery. The average shear and instability variables from 1991 to 1999 and moisture variable from 1995 to 1999 indicate that tropical cyclone formation in the early part of the season is limited by the vertical instability and midlevel moisture. Formation at the end of the season is limited by the vertical shear. On average, there is only a short period from mid-July to mid-October when all three variables are favorable for development. This observation helps explains why tropical cyclone formation in the tropical Atlantic has such a peaked distribution in time. The parameter also helps explain intra- and interseasonal variability in tropical cyclone formation. An independent evaluation of the parameter and possible applications to operational forecasting are presented using data from the 2000 hurricane season. The possibility of determining additional thermodynamic information from the GOES sounder is also discussed. C1 Colorado State Univ, NOAA, NESDIS, ORA, Ft Collins, CO 80523 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP DeMaria, M (reprint author), Colorado State Univ, NOAA, NESDIS, ORA, W Laporte Ave, Ft Collins, CO 80523 USA. RI Knaff, John /F-5599-2010; DeMaria, Mark/F-5583-2010 OI Knaff, John /0000-0003-0427-1409; NR 28 TC 126 Z9 134 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 2 BP 219 EP 233 DI 10.1175/1520-0434(2001)016<0219:ATCGPF>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 425GY UT WOS:000168283900002 ER PT J AU Hux, JD Knappenberger, PC Michaels, PJ Stenger, PJ Cobb, HD Rusnak, MP AF Hux, JD Knappenberger, PC Michaels, PJ Stenger, PJ Cobb, HD Rusnak, MP TI Development of a Discriminant Analysis Mixed Precipitation (DAMP) forecast model for mid-Atlantic winter storms SO WEATHER AND FORECASTING LA English DT Article ID EASTERN UNITED-STATES; FREEZING-RAIN; WEATHER AB The frequency of "wintry mix'' precipitation-freezing rain and ice pellets-is considerable in the mid-Atlantic region of the United States. Despite the fact that the general conditions necessary to support the various winter precipitation types have been known for years, in that region, the proper forecast of type and duration of winter precipitation is one of the most difficult challenges in operational meteorology, with extensive public safety and economic ramifications. The purpose of this project is to report on an improved methodology for winter precipitation forecasts. This study analyzed precipitation type and surface temperature data from NOAA's hourly surface airway observations and temperatures and heights for all mandatory and significant levels from NOAA's Radiosonde Data of North America from Washington Dulles International Airport, Virginia (1962-95), and Greensboro, North Carolina (1948-95). Precipitation that occurred within 2 h of a sounding for the months November through March was used for analysis. The upper-air data were combined to create vertical temperature profiles for each observation of precipitation type-rain, freezing rain mix, ice pellets, and snow. Those profiles were then categorized by the number of freezing levels (i.e., the number of times the sounding crossed the 0 degreesC isotherm) and examined to determine if they could be used to isolate specific precipitation types and as a result segregate winter precipitation scenarios by forecasting difficulty. Four basic temperature profiles were found for both Greensboro and Washington Dulles Airport during winter-zero, one, two, and three or more freezing level(s). Each of these profiles produced characteristic types of precipitation (snow, freezing rain, freezing rain mix, and rain); for each profile, either climatology or discriminant analysis was used to statistically determine precipitation type. The results of these analyses were used to develop the site-specific Discriminant Analysis Mixed Precipitation (DAMP) models for Greensboro and Washington Dulles Airport. The variables required to run the model are the height( s) of the freezing level( s) and critical temperature( s) from a modeled or observed sounding. The DAMP models are easy for the forecaster to use and understand and provide probability guidance in situations that are difficult to resolve. The overall classification results showed that the models were very effective for predicting precipitation type. Probabilities of detection were 98.4%, 85.8%, and 92.6% for rain, freezing rain mix, and snow, respectively, for Washington Dulles Airport, and 98.7%, 87.1%, and 89.7% for Greensboro. C1 Univ Virginia, State Climatol Off, Charlottesville, VA USA. Natl Weather Serv, Forecast Off, Wakefield, VA USA. RP Hux, JD (reprint author), 291 McCormick Rd,POB 400123, Charlottesville, VA 22904 USA. NR 25 TC 6 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 2 BP 248 EP 259 DI 10.1175/1520-0434(2001)016<0248:DOADAM>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 425GY UT WOS:000168283900004 ER PT J AU Friedman, KS Sikora, TD Pichel, WG Clemente-Colon, P Hufford, G AF Friedman, KS Sikora, TD Pichel, WG Clemente-Colon, P Hufford, G TI Using spaceborne synthetic aperture radar to improve marine surface analyses SO WEATHER AND FORECASTING LA English DT Article ID MESOSCALE CYCLONE ACTIVITY; POLAR LOW; SYNOPTIC CLIMATOLOGY; ANTARCTICA; IMAGERY; ALASKA; SEA AB The ever-changing weather and lack of in situ data in the Bering Sea warrants experimentation with new meteorological observing systems for this region. Spaceborne synthetic aperture radar (SAR) is well suited for observing the sea surface footprints of marine meteorological phenomena because its radiation is sensitive to centimeter-scale sea surface roughness, regardless of the time of day or cloud conditions. The near-surface wind field generates this sea surface roughness. Therefore, the sea surface footprints of meteorological phenomena are often revealed by SAR imagery when the main modulator of sea surface roughness is the wind. These attributes, in addition to the relatively high resolution of SAR products, make this instrument an excellent candidate for filling the meteorological observing needs over the Bering Sea. This study demonstrates the potential usefulness of SAR for observing Bering Sea meteorology by focusing on its ability to image the sea surface footprints of polar mesoscale cyclones (PMCs). These storms can form unexpectedly and are threatening to maritime interests. In this demonstration, a veteran meteorologist at the Anchorage National Weather Service Forecast Office is asked to produce a surface reanalysis for three separate archived cases when SAR imaged a PMC but the original analysis, produced without the aid of SAR data, did not display it. The results show that in these three cases the inclusion of SAR data in the analysis procedure leads to large differences between the original surface analysis and the reanalysis. Of particular interest is that, in each case, the PMC is added into the reanalysis. It is argued that the reanalyses more accurately portray the near-surface meteorology for each case. C1 Caelum Res Corp, Camp Springs, MD USA. USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Annapolis, MD USA. RP NOAA, WWBG, E RA3, Room 102,5200 Auth Rd, Camp Springs, MD 20746 USA. EM Karen.Friedman@noaa.gov RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 24 TC 11 Z9 11 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 EI 1520-0434 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 2 BP 270 EP 276 DI 10.1175/1520-0434(2001)016<0270:USSART>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 425GY UT WOS:000168283900006 ER PT J AU Scofield, RA AF Scofield, RA TI Comments on "A quantitative assessment of the NESDIS Auto-Estimator'' SO WEATHER AND FORECASTING LA English DT Editorial Material C1 NOAA, NESDIS, Camp Springs, MD 20746 USA. RP Scofield, RA (reprint author), NOAA, NESDIS, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 5 TC 6 Z9 7 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. PY 2001 VL 16 IS 2 BP 277 EP 278 DI 10.1175/1520-0434(2001)016<0277:COAQAO>2.0.CO;2 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 425GY UT WOS:000168283900007 ER PT J AU Brady, RH Waldstreicher, JS AF Brady, RH Waldstreicher, JS TI Observations of mountain wave-induced precipitation shadows over northeast Pennsylvania SO WEATHER AND FORECASTING LA English DT Article ID GRAVITY-WAVES; LEE WAVES; MODEL; TERRAIN; FLOW AB WSR-88D depictions of two mountain wave-induced precipitation shadows observed near the Wyoming Valley of northeast Pennsylvania are presented. These mountain waves developed in similar synoptic environments that featured a strong south to southeast low-level jet, a stable layer situated near mountaintop level, and cross-barrier flow that decreased with height. One event was associated with a well-defined, singular precipitation shadow, while the second event displayed multiple precipitation shadows. Subtle differences in the vertical distribution of temperature and wind shear between the two cases appeared to be instrumental in defining what type of structure the mountain wave and their associated precipitation shadows displayed. This is supported by calculations of Froude number, Brunt-Vaisala frequency, Scorer parameter, and horizontal wavelength for the two events. These mountain waves appear to have a significant effect on the local precipitation distribution in and near the heavily populated Wyoming Valley, with amounts reduced within and up to 15 km downstream of the valley. These effects are evident in the radar-estimated storm total precipitation products for both cases, and implied by rain gauge data for one of the events. Precipitation drift appears to play a role in the actual surface location of these precipitation minima with respect to the radar-indicated position, in cases of strong low-level flow. C1 NOAA, Natl Weather Serv, Johnson City, NY 13790 USA. RP Brady, RH (reprint author), NOAA, Natl Weather Serv, 32 Dawes Dr, Johnson City, NY 13790 USA. NR 38 TC 8 Z9 8 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 3 BP 281 EP 300 DI 10.1175/1520-0434(2001)016<0281:OOMWIP>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 440DE UT WOS:000169160000001 ER PT J AU Steenburgh, WJA Blazek, TR AF Steenburgh, WJA Blazek, TR TI Topographic distortion of a cold front over the Snake River Plain and central Idaho Mountains SO WEATHER AND FORECASTING LA English DT Article ID CONTINENTAL UNITED-STATES; LEVEL PRESSURE REDUCTION; ROCKY-MOUNTAINS; DOPPLER OBSERVATIONS; MESOSCALE OROGRAPHY; SURFACE-ANALYSIS; COAST; WIND; SYSTEM; RADAR AB The topographic distortion of a cold front over the Snake River Plain (SRP) and central Idaho Mountains on 3 December 1998 is described using high-density surface observations from MesoWest, a collection of meteorological networks over the western United States. Although relatively unperturbed upstream of central Idaho, the cold front became distorted as it was deflected and accelerated up the low-elevation SRP, where a pronounced frontal bulge developed. The speed of the cold front over the SRP was comparable to the magnitude of the postfrontal winds that, due to terrain channeling, were oriented normal to the front. Meanwhile, the front advanced more slowly over the central Idaho mountains and southwest Montana, becoming increasingly diffuse over the former. Eventually, cold air surrounded the central Idaho Mountains and the two portions of the cold front merged over eastern Idaho. The cold front intensified as it moved from the eastern to central SRP, with rapid changes in temperature and pressure observed at locations in the southern half of the SRP. Intensification of the cross-frontal temperature gradient in this region appeared to be the result of confluence between southerly prefrontal winds, which experienced downslope warming to the lee of the Jarbidge-Caribou Highlands, and terrain-channeled postfrontal winds. Although the rapid changes in temperature and pressure suggested that the front developed the local structure of a gravity current, the frontal motion over the SRP was not consistent with gravity current theory and instead appeared to be the result of advection of the front by the terrain-induced flow field. The case study illustrates the value of high-density and multielevation MesoWest observations for advancing knowledge of frontal evolution over the western United States and improving operational surface analyses. Such observations aid in the identification of large-scale airmass and circulation changes that can be masked by boundary layer processes, valley inversions, and local and mesoscale terrain-induced wind systems. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. NOAA, Cooperat Inst Reg Predict, Salt Lake City, UT 84112 USA. RP Steenburgh, WJA (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 East,Room 819, Salt Lake City, UT 84112 USA. NR 65 TC 15 Z9 15 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 3 BP 301 EP 314 DI 10.1175/1520-0434(2001)016<0301:TDOACF>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 440DE UT WOS:000169160000002 ER PT J AU Evans, JS Doswell, CA AF Evans, JS Doswell, CA TI Examination of derecho environments using proximity soundings SO WEATHER AND FORECASTING LA English DT Article ID CONVECTIVE STORMS; BOW ECHO; EVOLUTION; WINDS; MODEL; MESOCYCLONES; SYSTEMS AB Observed upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms. Sixty-seven derechos, accompanied by 113 proximity soundings, were identified during the years 1983-93. Owing to the large variability of the synoptic-scale environments associated with derechos, each derecho was further divided into categories based on the strength of synoptic-scale forcing associated with each event. Derechos are shown to develop and persist in a wide range of shear and instability conditions. Although this range of shear and instability narrows when derechos are grouped by synoptic-scale forcing strength, considerable variation of values remains, primarily with the shear. These results suggest that ambient shear and instability values alone are not sufficient to distinguish derecho environments from those associated with nonsevere mesoscale convective system (MCS) environments. Though the ground-relative (ambient) shear values vary, more consistency is found in the system-relative winds. It is found that midlevel system-relative winds are consistently weak, while low-level system-relative inflow is strong. This is especially valid for events associated with weak synoptic-scale forcing. Fast forward propagation is associated with weak system-relative midlevel winds, which may in turn be associated with outflow-dominated storms having strong cold pools at the ground. In addition, a comparison between weak forcing derecho and nonderecho MCSs suggests that it is the strength of the mean flow, and its possible effects on speed of movement, that enhance the potential for sustained severe wind gusts at the surface, given similar thermodynamic environments. These results indicate that there is a larger range of shear and instability environments associated with derechos than has been suggested by some observational studies and numerical cloud simulations. In addition, little correlation is evident in operational observations between events with strong cold pools and those with correspondingly strong low-level (0-2/0-3 km) ambient shear. Owing to the large variance of convective available potential energy (CAPE)/shear values found in this observational study, forecasters should be aware of the potential for derecho formation within environments with weaker shear than suggested by numerical simulations. This is especially true in the absence of a deep, progressive midtropospheric trough and an associated surface cold front. When synoptic-scale forcing is strong, derechos can develop and persist within environments with almost no CAPE evident on nearby upper air soundings. C1 Storm Predict Ctr, Norman, OK 73069 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Evans, JS (reprint author), Storm Predict Ctr, 1313 Halley CR, Norman, OK 73069 USA. RI Doswell III, Charles/E-7662-2010 NR 37 TC 106 Z9 111 U1 2 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 3 BP 329 EP 342 DI 10.1175/1520-0434(2001)016<0329:EODEUP>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 440DE UT WOS:000169160000004 ER PT J AU DeLisi, MP Cope, AM Franklin, JK AF DeLisi, MP Cope, AM Franklin, JK TI Weekly precipitation cycles along the northeast corridor? SO WEATHER AND FORECASTING LA English DT Article ID MELBOURNE AB Twenty years of precipitation data from seven cities along or near the east coast of the United States from the northern mid-Atlantic region to northern New England have been analyzed to determine if there are any weekly cycles in either daily precipitation frequency or intensity. Any such weekly cycle could be considered evidence of anthropogenic influence on the climate of that region. Data were examined for each individual site and for all sites combined. The data were subjected to various statistical procedures, including one-way analysis of variance, Student's t-test, and the chi-square goodness-of-fit test. Overall, results were not significant at the 95% confidence level. Thus, this study is unable to detect any weekly cycle in daily precipitation intensity or frequency. C1 Natl Weather Serv, Forecast Off, Mt Holly, NJ 08060 USA. Natl Weather Serv, Taunton, MA USA. RP DeLisi, MP (reprint author), Natl Weather Serv, Forecast Off, 732 Woodlane Rd, Mt Holly, NJ 08060 USA. NR 14 TC 20 Z9 21 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. PY 2001 VL 16 IS 3 BP 343 EP 353 DI 10.1175/1520-0434(2001)016<0343:WPCATN>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 440DE UT WOS:000169160000005 ER PT J AU Dunn, LB Vasiloff, SV AF Dunn, LB Vasiloff, SV TI Tornadogenesis and operational considerations of the 11 August 1999 Salt Lake City tornado as seen from two different Doppler radars SO WEATHER AND FORECASTING LA English DT Article ID SUPERCELL THUNDERSTORM; VORTEX; WATERSPOUT; COLORADO; ROTATION; TERRAIN; WSR-88D; ORIGINS AB On 11 August 1999 a climatologically rare F2 tornado developed just west of downtown Salt Lake City, Utah (SLC), and moved directly through the city during the noon hour. Tornadogenesis was observed from a mountaintop WSR-88D Doppler radar 76 km (41 n mi) to the northwest of and 0.7 km (2300 ft) above SLC and also from a Terminal Doppler Weather Radar (TDWR) located only 22.2 km (12 n mi) north of and at the same elevation as SLC. Data from the TDWR offer an unambiguous view of the development of a nondescending tornado as an intensifying updraft became juxtaposed over enhanced cyclonic shear along a surface-based convergence zone. The convergence zone intensified and developed upward with a circulation center directly beneath the updraft eventually contracting to the scale of a tornado vortex. After tornadogenesis, the previously disorganized thunderstorm displayed characteristics commonly associated with supercells, such as a hook echo, bounded weak-echo region, a WSR-88D algorithm detection of a mesocyclone, and a visible wall cloud. The mountaintop WSR-88D was able to identify the tornado in the base velocity data and via the latest operational version of the Tornado Detection Algorithm. However, interpretation of velocity products produced by the radar system for real-time operations was problematic due to degradation with range of the displayed data. Without access to the full-resolution velocity data in real time, it would be impossible for a forecaster to corroborate the algorithm tornado detection. C1 Natl Weather Serv, Forecast Off, Salt Lake City, UT 84116 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Dunn, LB (reprint author), Natl Weather Serv, Forecast Off, 2242 W N Temple, Salt Lake City, UT 84116 USA. NR 39 TC 9 Z9 9 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. PY 2001 VL 16 IS 4 BP 377 EP 398 DI 10.1175/1520-0434(2001)016<0377:TAOCOT>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 459UZ UT WOS:000170271000001 ER PT J AU Whiteman, CD Zhong, S Shaw, WJ Hubbe, JM Bian, X Mittelstadt, J AF Whiteman, CD Zhong, S Shaw, WJ Hubbe, JM Bian, X Mittelstadt, J TI Cold pools in the Columbia basin SO WEATHER AND FORECASTING LA English DT Article ID BOUNDARY-LAYER EVOLUTION; CANYONLAND BASIN; STABLE LAYERS; HEAT BUDGETS AB Persistent midwinter cold air pools produce multiday periods of cold, dreary weather in basins and valleys. Persistent stable stratification leads to the buildup of pollutants and moisture in the pool. Because the pool sometimes has temperatures below freezing while the air above is warmer, freezing precipitation often occurs, with consequent effects on transportation and safety. Forecasting the buildup and breakdown of these cold pools is difficult because the interacting physical mechanisms leading to their formation, maintenance, and destruction have received little study. In this paper, persistent wintertime cold pools in the Columbia River basin of eastern Washington are studied. First a succinct meteorological definition of a cold pool is provided and then a 10-yr database is used to develop a cold pool climatology. This is followed by a detailed examination of two cold pool episodes that were accompanied by fog and stratus using remote and in situ temperature and wind sounding data. The two episodes illustrate many of the physical mechanisms that affect cold pool evolution. In one case, the cold pool was formed by warm air advection above the basin and was destroyed by downslope winds that descended into the southern edge of the basin and progressively displaced the cold air in the basin. In the second case, the cold pool began with a basin temperature inversion on a clear night and strengthened when warm air was advected above the basin by a westerly flow that descended from the Cascade Mountains. The cold pool was nearly destroyed one afternoon by cold air advection aloft and by the growth of a convective boundary layer (CBL) following the partial breakup of the basin stratus. The cold pool restrengthened, however, with nighttime cooling and was destroyed the next afternoon by a growing CBL. C1 Pacific NW Natl Lab, Richland, WA USA. NOAA, NWS, Forecast Off, Pendleton, OR USA. RP Whiteman, CD (reprint author), Battelle NW Lab, POB 999, Richland, WA 99352 USA. NR 24 TC 72 Z9 72 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 4 BP 432 EP 447 DI 10.1175/1520-0434(2001)016<0432:CPITCB>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 459UZ UT WOS:000170271000004 ER PT J AU Toth, Z Zhu, YJ Marchok, T AF Toth, Z Zhu, YJ Marchok, T TI The use of ensembles to identify forecasts with small and large uncertainty SO WEATHER AND FORECASTING LA English DT Article ID PREDICTION SYSTEM; SKILL AB In the past decade ensemble forecasting has developed into an integral part of numerical weather prediction. Flow-dependent forecast probability distributions can be readily generated from an ensemble, allowing for the identification of forecast cases with high and low uncertainty. The ability of the NCEP ensemble to distinguish between high and low uncertainty forecast cases is studied here quantitatively. Ensemble mode forecasts, along with traditional higher-resolution control forecasts, are verified in terms of predicting the probability of the true state being in 1 of 10 climatologically equally likely 500-hPa height intervals. A stratification of the forecast cases by the degree of overall agreement among the ensemble members reveals great differences in forecast performance between the cases identified by the ensemble as the least and most uncertain. A new ensemble-based forecast product, the "relative measure of predictability,'' is introduced to identify forecasts with below and above average uncertainty. This measure is standardized according to geographical location, the phase of the annual cycle, lead time, and also the position of the forecast value in terms of the climatological frequency distribution. The potential benefits of using this and other ensemble-based measures of predictability is demonstrated through synoptic examples. C1 NCEP, Environm Modeling Ctr, Camp Springs, MD 20746 USA. RP Toth, Z (reprint author), NCEP, Environm Modeling Ctr, 5200 Auth Rd,Room 207, Camp Springs, MD 20746 USA. RI Toth, Zoltan/I-6624-2015 OI Toth, Zoltan/0000-0002-9635-9194 NR 28 TC 41 Z9 55 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. PY 2001 VL 16 IS 4 BP 463 EP 477 DI 10.1175/1520-0434(2001)016<0463:TUOETI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 459UZ UT WOS:000170271000006 ER PT J AU Hunter, SM Underwood, SJ Holle, RL Mote, TL AF Hunter, SM Underwood, SJ Holle, RL Mote, TL TI Winter lightning and heavy frozen precipitation in the southeast United States SO WEATHER AND FORECASTING LA English DT Article ID CONDITIONAL SYMMETRIC INSTABILITY; MARCH 1993 SUPERSTORM; SYNOPTIC-SCALE; THUNDERSTORMS; CYCLOGENESIS; SNOWSTORMS; MESOSCALE AB This study addresses winter season lightning by examining synoptic-scale circulations, cloud-to-ground (CG) lightning patterns, and frozen precipitation. Specifically, locations, frequencies, and polarities of CG flashes are related to the location, intensity, and type of heavy frozen precipitation (snow, freezing rain, or ice pellets) for seven winter storms affecting the southeast United States from 1994 through 1997. The results suggest two distinct phases of winter storm development, each producing different patterns of CG lightning and frozen precipitation. These phases are termed the arctic front (AF) and migratory cyclone (MC) types. Analysis was performed on 27 periods within the seven cases. In several periods, there were significant numbers of CG flashes within or near a subfreezing surface air mass and frozen precipitation when a quasistationary arctic front existed. These periods were classified as AF phases. This flash pattern indicates a connection between the intensity of convection (associated with CG flashes) and downwind frozen precipitation. In these situations there was strong southwesterly flow aloft, which may have advected ice particles from these convective clouds into stratiform clouds near the frontal surface. This process resembles the "seeder-feeder'' mechanism of precipitation growth. The AF phases eventually developed into MC phases, and the latter were more common in this study. The MC phases in general exhibit a different spatial relationship between CG lightning and heavy frozen precipitation; that is, CG flashes retreat toward the warm sector of the cyclone and thus are not proximal to the 0 degreesC surface isotherm. There appears to be little connection between convection and frozen precipitation in most of these situations. The distinction between AF and MC phases, in conjunction with CG lightning monitoring, may aid forecasts of the duration and amount of frozen precipitation during winter storms. C1 NOAA, Natl Weather Serv, Dodge City, KS USA. Calif State Univ Fresno, Dept Geog, Fresno, CA 93740 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Georgia, Dept Geog, Athens, Greece. RP US Bur Reclamat, Denver, CO 80225 USA. EM smhunter@do.usbr.gov NR 37 TC 16 Z9 16 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 EI 1520-0434 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 4 BP 478 EP 490 DI 10.1175/1520-0434(2001)016<0478:WLAHFP>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 459UZ UT WOS:000170271000007 ER PT J AU Grasso, LD Hilgendorf, ER AF Grasso, LD Hilgendorf, ER TI Observations of a severe left moving thunderstorm SO WEATHER AND FORECASTING LA English DT Article ID NUMERICAL-SIMULATION; EVOLUTION; DYNAMICS; SHEAR AB Observations have shown that right moving thunderstorms are favored in environments characterized by clockwise-turning hodographs. There are, however, a few observational and numerical studies of long-lived, left moving storms within environments characterized by clockwise-turning hodographs. For example, a documented left mover that occurred on 26 May 1992, near Coldspring, Texas, with a mesoanticyclone and hail spike (also called a three-body scattering signature) produced severe weather. Although a few cases have been documented, left moving thunderstorms have received less study than right moving cells. The long-lived, severe thunderstorm of 17 May 1996 is presented to improve documentation of left moving thunderstorms. The storm occurred over eastern Nebraska and will be referred to as the York County storm. This left mover resulted from storm splitting and moved to the west of a surface cold front. The relatively isolated storm subsequently split approximately 1 h later, yielding a new right moving thunderstorm. Doppler radial velocities suggested the existence of a mesoanticyclone within the York County storm. Hail, 1.75 in. in diameter, was produced by the storm around the time the updraft split. There were many similarities between the York County storm and the 26 May 1992 Coldspring left moving severe thunderstorm. Both storms were relatively isolated, contained mesoanticyclones, and produced severe weather after the vertically integrated liquid water obtained a maximum value. Due to the dearth of material on left-moving storms, general statements concerning their evolution are lacking. This current study is a first step toward improving the sparse documentation of such thunderstorms. More work is needed in this area to help identify physical processes that lead to left moving thunderstorms, particularly those that become severe. C1 Colorado State Univ, NOAA, NESDIS, RAMMT CIRA, Ft Collins, CO 80523 USA. RP Grasso, LD (reprint author), Colorado State Univ, NOAA, NESDIS, RAMMT CIRA, W Laporte Ave, Ft Collins, CO 80523 USA. NR 26 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 4 BP 500 EP 511 DI 10.1175/1520-0434(2001)016<0500:OOASLM>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 459UZ UT WOS:000170271000009 ER PT J AU Dostalek, JF Schmit, TJ AF Dostalek, JF Schmit, TJ TI Total precipitable water measurements from GOES sounder derived product imagery SO WEATHER AND FORECASTING LA English DT Article ID RETRIEVAL ALGORITHM; ENVIRONMENT; SOUNDINGS AB Statistics are compiled comparing calculations of total precipitable water (TPW) as given by GOES sounder derived product imagery (DPI) to that computed from radiosonde data for the 12-month period March 1998-February 1999. In order to investigate the impact of the GOES sounder data, these results are evaluated against statistics generated from the comparison between the first guess fields used by the DPI (essentially Eta Model forecasts) and the radiosonde data. It is found that GOES data produce both positive and negative results. Biases in the first guess are reduced for moist atmospheres, but are increased in dry atmospheres. Time tendencies in TPW as measured by the DPI show a higher correlation to radiosonde data than does the first guess. Two specific examples demonstrating differences between the DPI and Eta Model forecasts are given. C1 Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. NOAA, NESDIS, Adv Satellite Prod Team, Off Res & Applicat, Madison, WI USA. RP Dostalek, JF (reprint author), Colorado State Univ, Cooperat Inst Res Atmosphere, W Laporte Ave, Ft Collins, CO 80523 USA. RI Schmit, Timothy/F-5624-2010 NR 19 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 5 BP 573 EP 587 DI 10.1175/1520-0434(2001)016<0573:TPWMFG>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478ME UT WOS:000171349300004 ER PT J AU Marzban, C Witt, A AF Marzban, C Witt, A TI A Bayesian neural network for severe-hail size prediction SO WEATHER AND FORECASTING LA English DT Article ID DOPPLER RADAR; VERIFICATION; PROBABILITY; FORECASTS; ALGORITHM; WSR-88D AB The National Severe Storms Laboratory has developed algorithms that compute a number of Doppler radar and environmental attributes known to be relevant for the detection/prediction of severe hail. Based on these attributes, two neural networks have been developed for the estimation of severe-hail size: one for predicting the severe-hail size in a physical dimension, and another for assigning a probability of belonging to one of three hail size classes. Performance is assessed in terms of multidimensional (i.e., nonscalar) measures. It is shown that the network designed to predict severe-hail size outperforms the existing method for predicting severe-hail size. Although the network designed for classifying severe-hail size produces highly reliable and discriminatory probabilities for two of the three hail-size classes (the smallest and the largest), forecasts of midsize hail, though highly reliable, are mostly nondiscriminatory. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale & Meteorol Studies, Norman, OK 73019 USA. Univ Oklahoma, Dept Phys, Norman, OK 73019 USA. RP Marzban, C (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 29 TC 48 Z9 52 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 5 BP 600 EP 610 DI 10.1175/1520-0434(2001)016<0600:ABNNFS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478ME UT WOS:000171349300006 ER PT J AU Koch, SE Saleeby, S AF Koch, SE Saleeby, S TI An automated system for the analysis of gravity waves and other mesoscale phenomena SO WEATHER AND FORECASTING LA English DT Article ID MIDLATITUDE SQUALL LINE; TRAILING REGION; STRATIFORM RAIN; UNITED-STATES; PRECIPITATION; PREDICTION; SATELLITE; CCOPE; RADAR AB An automated near-real-time system for the surface analysis of gravity waves and other mesoscale phenomena is developed, tested, and applied to several cases. Five-minute observations from the Automated Surface Observing System (ASOS) network provide the primary source of data for the mesoanalysis system. ASOS time series data are downloaded, subjected to considerable quality control, bandpass filtered, and objectively analyzed using a time-to-space conversion (TSC) adaptation of the traditional Barnes scheme. The resultant analyses, which can resolve features in the ASOS network with wavelengths as short as 150 km and at 15-min intervals, are made available as animated contoured fields. Even though this mesoanalysis system was designed primarily for gravity wave detection, it is capable of resolving other kinds of mesoscale phenomena and allowing the analyst to monitor their changing structure. The effectiveness of the system is demonstrated with two recent events selected from several cases that have been analyzed. The first case consisted of a gravity wave train that propagated through the Ohio River valley and produced multiple precipitation bands. The second event involved a complex family of mesohighs and wake lows associated with a convective system over the southeastern United States. Variations in the surface wind field and precipitation distribution are related to the mesoscale pressure field in both cases. The ability of this mesoanalysis system to monitor mesoscale phenomena resides in the successful application of TSC principles to high temporal resolution surface data. Although the TSC assumption may not be strictly valid in more complex situations, for many applications this mesoanalysis system offers critical information needed for making accurate nowcasts, with the caveat that the means by which ASOS 5-min data are made available can be improved. C1 NOAA, Forecast Syst Lab, Boulder, CO 80305 USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP NOAA, Forecast Syst Lab, R-FS1,325 Broadway, Boulder, CO 80305 USA. EM koch@fsl.noaa.gov NR 32 TC 16 Z9 16 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 EI 1520-0434 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 6 BP 661 EP 679 DI 10.1175/1520-0434(2001)016<0661:AASFTA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 502AT UT WOS:000172721400002 ER PT J AU Connell, BH Gould, KJ Purdom, JFW AF Connell, BH Gould, KJ Purdom, JFW TI Resolution GOES-8 visible and infrared cloud frequency composites over northern Florida during the summers 1996-99 SO WEATHER AND FORECASTING LA English DT Article ID UNITED-STATES; SATELLITE; CLIMATOLOGIES; CONVECTION; 1ST AB GOES-8 visible and infrared cloud frequency composites have been created from imagery collected during June, July, and August for the years 1996-99 over northern Florida. These cloud frequency composites are unique because they offer high-resolution coverage over a small area and have been tailored to address forecast needs. Both monthly and regime cloud frequency composites are presented. Nine regimes were designated to reflect the strength and development of the sea-breeze front under various synoptic winds and the resulting effect on convective development. The regimes were designated by mean boundary layer wind speed and direction over the region of interest. Results from four of the regimes are presented. A total of 222 days (60% of all possible days) were designated for the various wind regimes. Regime 4 (W to SW flow) occurred most frequently (24%) and had the most widespread distribution of higher cloud frequency, occurring both near the coast and inland. Regime 2, with contrasting E to NE flow, was the next most frequently occurring regime (17%) and had lower cloud frequencies, particularly inland in Alabama and Georgia. Regime 5, with strong W to SW flow (15%, not presented) was third, followed by Regime 8 with N to NW flow (13%) and Regime 1 (11%) with light and variable or light SE flow. The monthly composites included the days from the various regime days as well as those with a completely disturbed or completely suppressed sea-breeze circulation. Nonetheless, the influence of the sea-breeze circulation can readily be seen in the diurnal progression of cloud frequency over a month. The variations seen in monthly cloud frequency composites for June, July, and August 1996-99 highlight periods of high and low cloud frequency and offer a different perspective on year-to-year and month-to-month variability. The regime cloud frequency results are actively being used during the summer season in aviation and public forecasting to supplement available information. C1 Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. Natl Weather Serv, Tallahassee, FL USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Camp Springs, MD USA. RP Connell, BH (reprint author), Colorado State Univ, Cooperat Inst Res Atmosphere, Foothills Campus, Ft Collins, CO 80523 USA. NR 15 TC 13 Z9 14 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. PY 2001 VL 16 IS 6 BP 713 EP 724 DI 10.1175/1520-0434(2001)016<0713:HRGVAI>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 502AT UT WOS:000172721400005 ER PT J AU Grumm, RH Hart, R AF Grumm, RH Hart, R TI Standardized anomalies applied to significant cold season weather events: Preliminary findings SO WEATHER AND FORECASTING LA English DT Article ID MERGER CYCLOGENESIS EVENT; 25-26 JANUARY 1978; UNITED-STATES; WAVE; PRECIPITATION; FLOOD AB Forecasting significant weather events, such as floods, heat waves, arctic outbreaks, ice storms, large severe weather outbreaks, and major winter storms, is a critical function for all weather services. However, conventional pressure level geopotential and temperature fields often are insufficient to determine whether an event represents a large departure from normal. This is largely due to the variability that exists throughout the year and regionally throughout the world. What represents an unusual departure from average conditions in fall may not be as unusual in winter. What is an unusual departure from average conditions in California may be normal in New England. This paper presents a method, normalized field departures from local climatology, that gives forecasters guidance on the relative rarity of events. Thus, in this paper a method is presented to help forecasters identify potentially significant weather events. The focus of this paper is on significant winter storms. However, a record winter warmth event is shown to demonstrate the broad potential use of this method. The results suggest that many record snowstorms in the literature were associated with storms that departed significantly from normal. Using model data, it is demonstrated that models can successfully forecast events that represent a significant departure from normal. In fact, the results suggest that the models are quite successful at forecasting unusually strong weather systems in the short range (2-3 days) and show some success out to 6 days. C1 NOAA, Natl Weather Serv, State Coll, PA USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Grumm, RH (reprint author), Natl Weather Serv Off, 277 W Beaver Ave,Suite 402, State Coll, PA 16801 USA. NR 22 TC 36 Z9 37 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2001 VL 16 IS 6 BP 736 EP 754 DI 10.1175/1520-0434(2001)016<0736:SAATSC>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 502AT UT WOS:000172721400007 ER PT B AU McLean, C Shao, GD AF McLean, C Shao, GD BE Peters, BA Smith, JS Medeiros, DJ Rohrer, MW TI Simulation of shipbuilding operations SO WSC'01: PROCEEDINGS OF THE 2001 WINTER SIMULATION CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT Winter Simulation Conference (WSC 01) CY 2001 CL ARLINGTON, VA SP Amer Stat Assoc, ACM SIGSIM, IEEE Comp Soc, IEEE Syst, Man & Cybernet Soc, Inst Ind Engineers, INFORMS Coll Simulat, Natl Inst Stand & Technol, Soc Comp Simulat Int AB This paper discusses the objectives and requirements for a shipbuilding simulation. It presents an overview of a generic simulation of shipbuilding operations. The shipbuilding simulation model can be used as a tool to analyze the schedule impact of new workload, evaluate production scenarios, and identify resource problems. The simulation helps identify resource constraints and conflicts between competing jobs. The simulation can be used to show expected results of inserting new technologies or equipment into the shipyard, particularly with respect to operating costs and schedule impact. The use of DOD High Level Architecture (HLA) and Run Time Infrastructure (RTI) as an integration mechanism for distributed simulation is also discussed briefly. C1 NIST, Mfg Simulat & Visualizat Grp, Gaithersburg, MD 20899 USA. RP McLean, C (reprint author), NIST, Mfg Simulat & Visualizat Grp, 100 Bur Dr,Ms 8260, Gaithersburg, MD 20899 USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7307-3 PY 2001 BP 870 EP 876 PG 7 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BV20W UT WOS:000178162700113 ER PT B AU McLean, C Leong, S AF McLean, C Leong, S BE Peters, BA Smith, JS Medeiros, DJ Rohrer, MW TI The expanding role of simulation in future manufacturing SO WSC'01: PROCEEDINGS OF THE 2001 WINTER SIMULATION CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT Winter Simulation Conference (WSC 01) CY 2001 CL ARLINGTON, VA SP Amer Stat Assoc, ACM SIGSIM, IEEE Comp Soc, IEEE Syst, Man & Cybernet Soc, Inst Ind Engineers, INFORMS Coll Simulat, Natl Inst Stand & Technol, Soc Comp Simulat Int AB Simulation technology holds tremendous promise for reducing costs, improving quality, and shortening the time-to-market for manufactured goods. Unfortunately, this technology still remains largely under-utilized by industry today. This paper suggests benefits to industry resulting from the widespread, pervasive implementation of manufacturing simulation technology. Potential simulation impact areas are closely intertwined with strategic manufacturing. Yet, a number of factors currently inhibit the deployment of simulation technology in industry today. The development of new simulation interface standards could help increase the deployment of simulation technology. Interface standards could improve the accessibility of this technology by helping to reduce the expenses associated with acquisition and deployment, minimize model development time and costs, and provide new types of simulation functionality that are not available today. C1 Natl Inst Stand & Technol, Mfg Simulat & Modeling Grp, Gaithersburg, MD 20899 USA. RP McLean, C (reprint author), Natl Inst Stand & Technol, Mfg Simulat & Modeling Grp, Gaithersburg, MD 20899 USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7307-3 PY 2001 BP 1478 EP 1486 PG 9 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BV20W UT WOS:000178162700202 ER PT S AU Jach, T Durbin, S Bakulin, A Bright, D Stagarescu, CB Srajer, G Haskel, D Pedulla, J AF Jach, T Durbin, S Bakulin, A Bright, D Stagarescu, CB Srajer, G Haskel, D Pedulla, J BE McNulty, I TI Wide-field x-ray microscopy with Kirkpatrick-Baez optics SO X-RAY MICRO- AND NANO-FOCUSING: APPLICATIONS AND TECHNIQUES II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Micro- and Nano-Focusing - Applications and Techniques II CY JUL 30, 2001 CL SAN DIEGO, CA SP SPIE DE x-ray; Kirkpatrick-Baez; microscope; multilayer; imaging ID SYNCHROTRON RADIATION; MICROPROBE AB Modem technology permits the fabrication of Kirkpatrick-Baez (KB) multilayer optics with performance close to the theoretical limit. We have constructed a KB field-imaging microscope which operates in the x-ray energy range 6-10 keV with a field of view of 40-150 pm. The optics perform at a reflectivity of 80% at the first Bragg peak. Using highly-collimated synchrotron radiation, we realize a resolution of 900 nm at 9 keV. The intensity and magnification are sufficient to perforin real-time imaging with a CCD x-ray camera, with increases in field of view and resolution at this energy due to improvements in both data collection and image processing. The collimation of the incident radiation corresponds to Kohler illumination. The dynamic range of the images using a 12-bit camera allows us to extend the field of view at the Bragg reflection over several Kiessig fringes. We have adjusted the energy to take advantage of absorption at the excitation edges of elements and have performed imaging using circularly polarized radiation. We have used this instrument to demonstrate wide-field imaging in both absorption and diffraction, We resent magnified images of multiple layers in a test integrated circuit in absorption and of a metal single crystal in diffraction. C1 NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Jach, T (reprint author), NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4213-5 J9 P SOC PHOTO-OPT INS PY 2001 VL 4499 BP 38 EP 44 DI 10.1117/12.450220 PG 7 WC Microscopy; Optics; Imaging Science & Photographic Technology SC Microscopy; Optics; Imaging Science & Photographic Technology GA BU13P UT WOS:000175126400006 ER PT S AU McCray, R AF McCray, R BE Holt, SS Hwang, U TI SN1987A: the youngest supernova remnant SO YOUNG SUPERNOVA REMNANTS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Annual Astrophysics Conference CY OCT 16-18, 2000 CL COLLEGE PK, MD ID SPACE-TELESCOPE OBSERVATIONS; SN 1987A; X-RAY; CIRCUMSTELLAR RING; SN-1987A; EMISSION; MODEL; PROGENITOR; DISTANCE; IMPACT AB Supernova 1987A became a supernova remnant about 10 years after outburst, when the luminosity resulting from the impact of its debris with its circumstellar matter dominated the luminosity due to internal radioactivity. Today, with the Hubble Space Telescope, we clearly see optical and ultraviolet emission from the reverse shock and from several "hot spots," where the blast wave is beginning to strike the inner circumstellar ring. With the Chandra Observatory, we also see X-ray emission from the hot shocked gas between the reverse shock and the blast wave. Here I review the observations of this remarkable event and forecast what we can expect to see during the coming decade. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP McCray, R (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0001-6 J9 AIP CONF PROC PY 2001 VL 565 BP 95 EP 108 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BS29B UT WOS:000169367800012 ER PT J AU German, CR Livermore, RA Baker, ET Bruguier, NI Connelly, DP Cunningham, AP Morris, P Rouse, IP Statham, PJ Tyler, PA AF German, CR Livermore, RA Baker, ET Bruguier, NI Connelly, DP Cunningham, AP Morris, P Rouse, IP Statham, PJ Tyler, PA TI Hydrothermal plumes above the East Scotia Ridge: an isolated high-latitude back-arc spreading centre SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE hydrothermal conditions; spreading centers; Antarctica; biogeography ID MID-ATLANTIC RIDGE; PACIFIC RISE; MANGANESE; DEEP AB We have identified first evidence for the presence of submarine hydrothermal activity along the East Scotia Ridge an isolated back-are spreading centre located at 55-60 degreesS in the Atlantic sector of the Southern Ocean. Using a combination of in situ optical light-scattering sensor data, and total dissolvable Mn concentrations, we demonstrate the existence of hydrothermal plumes overlying two segments of this similar to 500 km ridge-crest; both segments exhibit anomalous topography and at least one segment is also underlain by an axial magma chamber seismic reflector. Future investigation of the fauna that inhabit these remote hydrothermal environments may provide an important 'missing link' between the distinct biogeographical provinces delimited from previous investigation of northern Atlantic versus eastern Pacific vent-sites. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England. British Antarctic Survey, Cambridge CB3 0ET, England. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP German, CR (reprint author), Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England. NR 31 TC 43 Z9 46 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC 30 PY 2000 VL 184 IS 1 BP 241 EP 250 DI 10.1016/S0012-821X(00)00319-8 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 391CA UT WOS:000166335500018 ER PT J AU Grell, GA Schade, L Knoche, R Pfeiffer, A Egger, J AF Grell, GA Schade, L Knoche, R Pfeiffer, A Egger, J TI Nonhydrostatic climate simulations of precipitation over complex terrain SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HIGH-RESOLUTION GCM; CONVECTIVE SYSTEMS; MODEL; ALPS AB A climate version of the nonhydrostatic fifth-generation Penn State/NCAR Mesoscale Model has been used to downscale a global climate scenario to cloud-resolving scales over complex terrain (the Alps). After first describing the model and methodology, we then present comparison results from the model-predicted and ensemble-averaged regional-scale winter and summer season precipitation distribution with results from the global simulation and analyzed observed precipitation climatologies. Finally, results from the cloud-resolving simulations are compared to the regional simulations. It is shown that the degree to which the terrain is resolved in the various runs significantly alters the simulation of the precipitation climatologies. This is caused not only by the complex interaction of the flow with the topography but also by the different treatment of the convective processes (resolved versus nonresolved) in the model. Even in winter, the model-simulated seasonally averaged precipitation patterns change drastically with every increase in horizontal resolution. Furthermore, with a horizontal grid resolution of 1 km, when seen on a local scale and over complex terrain, the model-simulated precipitation patterns are not guaranteed to converge to one solution. This behavior is still more complicated in summer. Here it is shown that parameterized convection in the regional model simulation tends to be locked to the mountains, while in the cloud-resolving simulations the convection moves with the upper level flow, producing precipitation maxima away from the mountain tops. C1 Univ Munich, Inst Meteorol, D-8000 Munich, Germany. Fraunhofer Inst Atmosphar Umweltforsch, D-8100 Garmisch Partenkirchen, Germany. RP NOAA, OAR, FSL, CIRES, 325 Bdwy, Boulder, CO 80305 USA. EM grell@fsl.noaa.gov RI Knoche, Richard/A-7090-2013; Garmisch-Pa, Ifu/H-9902-2014; grell, georg/B-6234-2015 OI grell, georg/0000-0001-5214-8742 NR 20 TC 25 Z9 25 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 2000 VL 105 IS D24 BP 29595 EP 29608 DI 10.1029/2000JD900445 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 391LY UT WOS:000166358500023 ER PT J AU Mo, K Kanamitsu, M Juang, HMH Hong, SY AF Mo, K Kanamitsu, M Juang, HMH Hong, SY TI Ensemble regional and global climate prediction for the 1997/1998 winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SURFACE TEMPERATURE ANOMALIES; SOUTHERN OSCILLATION; SPECTRAL MODEL; PRECIPITATION; SIMULATION; NCEP/NCAR; SKILL AB The ensemble global and regional forecasts for the 1997/1998 winter were made in October 1997. The forecasted sea surface temperature anomalies (SSTA) in the tropical Pacific are obtained from the National Centers for Environmental Prediction (NCEP) coupled atmosphere-ocean model. Outside of the tropical Pacific the observed SSTs at the initial date are relaxed to the SST climatology with the e-folding time of 1 month. The global forecasts with the resolution of T62 are then downscaled using the NCEP regional spectral model (RSM) to enhance precipitation and temperature anomalies over the United States. The horizontal resolution of the RSM is 50 km. The global forecasts over this warm El Nino-Southern Oscillation (ENSO) winter have high skill over the Pacific North American region. Overall, the RSM downscaling improves the surface temperature and precipitation forecasts over the United States. However, it is more difficult to predict precipitation over a small region with certainty, because the spread among the members in the ensemble increases with the increase of horizontal resolution. The 50-km RSM model is unable to forecast anomalies over high mountains and many centers of precipitation maxima along the California coast. The sensitivity test shows that to forecast basin scale precipitation, a regional model with 20 km or less is needed. Although the 20-km RSM forecasts tend to overestimate precipitation maxima, it provides a more realistic distribution of precipitation. It can distinguish rainfall belts over high mountains and the relative dryness over the valley. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. NOAA, Environm Modelling Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. RP Mo, K (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, W-NP51,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 33 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 2000 VL 105 IS D24 BP 29609 EP 29623 DI 10.1029/2000JD900260 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 391LY UT WOS:000166358500024 ER PT J AU Hong, SY Pan, HL AF Hong, SY Pan, HL TI Impact of soil moisture anomalies on seasonal, summertime circulation over North America in a Regional Climate Model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CENTRAL UNITED-STATES; LATERAL BOUNDARY; SPECTRAL MODEL; LAND-SURFACE; 1988 DROUGHT; SENSITIVITY; PARAMETERIZATION; SIMULATION; RAINFALL; PRECIPITATION AB The impact of initial soil moisture on seasonal? summertime atmospheric circulation over North America is investigated using the National Centers for Environmental Prediction Regional Spectral Model (NCEP RSM). Three-month-long simulations are conducted for the two summers, May-June-July (MJJ) 1988 (drought in the Great Plains) and MJJ 1993 (a flooding event). Overall, the climate responses due to soil moisture anomalies in the RSM is in line with the previous findings from global models and observational studies, with strong positive feedback between initial soil moisture anomalies and simulated seasonal precipitation. The impact of the initial soil moisture anomalies persists for the 3-month integration period, but effects are mostly confined to the near-surface climate with little impact on the dynamic circulation in the upper troposphere. Influence of soil moisture anomaly on the low-level structure and their interaction with precipitation mechanism are highlighted. The regional climate responses in the RSM were not significantly dependent on the size of the domain of integration. C1 NCEP, EMC, Camp Springs, MD 20746 USA. Gen Sci Corp, Beltsville, MD USA. RP Hong, SY (reprint author), NCEP, EMC, 5200 Auth Rd,Room 207, Camp Springs, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 32 TC 35 Z9 38 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 2000 VL 105 IS D24 BP 29625 EP 29634 DI 10.1029/2000JD900276 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 391LY UT WOS:000166358500025 ER PT J AU Magid, LJ Li, Z Butler, PD AF Magid, LJ Li, Z Butler, PD TI Flexibility of elongated sodium dodecyl sulfate micelles in aqueous sodium chloride: A small-angle neutron scattering study SO LANGMUIR LA English DT Article ID POLYMER-LIKE MICELLES; ELASTIC LIGHT-SCATTERING; SHEAR-INDUCED STRUCTURES; 2ND VIRIAL-COEFFICIENT; PERSISTENCE LENGTH; EXCLUDED-VOLUME; CETYLPYRIDINIUM BROMIDE; SEMIFLEXIBLE POLYMERS; ANGULAR DISSYMMETRY; SURFACTANT MICELLES AB Aqueous salt solutions containing elongated micelles of sodium dodecyl sulfate (SDS) have been studied at 45 degreesC using small-angle neutron scattering. At NaCl concentrations in the 1-2 M range, the scattering data are consistent with semiflexible rather than rigid rodlike micelles, and this conclusion is consistent with previous studies of SDS micelles using small-angle scattering. However, until now quantitative determinations of micellar flexibility, that is, of persistence lengths, especially as a function of ionic strength, have not been available. By making measurements in the range of scattering vectors appropriate for this length scale and by incorporating the effect of intermicellar interactions into the fitting protocol, it has been possible to determine persistence lengths accurately. Partitioning of the values into intrinsic and electrostatic components is discussed, and the results are compared with data for the highly flexible anionic polyelectrolyte sodium polystyrenesulfonate. The one-dimensional bending moduli for the flexible SDS micelles are compared to the analogous two-dimensional bending moduli for SDS bilayers. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Natl Inst Stand & Technol, NCNR, Gaithersburg, MD 20899 USA. RP Magid, LJ (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RI Butler, Paul/D-7368-2011 NR 58 TC 84 Z9 87 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 26 PY 2000 VL 16 IS 26 BP 10028 EP 10036 DI 10.1021/la0006216 PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 388DG UT WOS:000166161700014 ER PT J AU Glazier, SA Vanderah, DJ Plant, AL Bayley, H Valincius, G Kasianowicz, JJ AF Glazier, SA Vanderah, DJ Plant, AL Bayley, H Valincius, G Kasianowicz, JJ TI Reconstitution of the pore-forming toxin alpha-hemolysin in phospholipid/18-octadecyl-1-thiahexa(ethylene oxide) and phospholipid/n-octadecanethiol supported bilayer membranes SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; HEPTAMERIC TRANSMEMBRANE PORE; LIPID BILAYERS; ION-CHANNEL; INFRARED-SPECTROSCOPY; DIELECTRIC-CONSTANT; THIOL MONOLAYERS; GOLD SURFACES; BETA-BARREL; PROTEIN AB We are studying the functional reconstitution of membrane-bound proteins into supported bilayer membranes (SBMs). Here, we describe the physical properties of SBMs formed by a layer of egg-phosphatidyl choline deposited on a monolayer of either 18-octadecyl-1-thiahexa(ethylene oxide) [THEO-C-18] or n-octadecanethiol on gold. We also show that the pore-forming protein a-hemolysin (alpha HL) self-assembles in these thin films. The insulating properties and the stability of the THEO-C-18 self-assembled monolayers were characterized by ac impedance spectroscopy and voltammetry. An impedance model, including constant phase elements, was determined for THEO-C-18 monolayers and the SBMs. Cyclic voltammetry measurements demonstrated virtually full blockage of ferricyanide oxidation and reduction by the THEO-C-18 monolayers. The monolayer stability test showed that, at applied potentials between +/-400 mV versus Ag/AgCl in 3 M KCl, the electrical properties of THEO-C-18 SAMs did not change with time. The reconstitution bf alpha HL in SBMs caused a decrease in impedance and an increased permeability to redox ions. The impedance model parameters suggest that alpha HL partially penetrates into the SBMs, increasing the dielectric constant of the alkane portion of the monolayers. The complete reconstitution of alpha HL that could provide the free access of the redox ions to the metal surface was not observed in these thin films. C1 Natl Inst Stand & Technol, Div Biotechnol, Biomol Mat Grp, Gaithersburg, MD 20899 USA. Texas A&M Univ Syst, Ctr Hlth Sci, Dept Med Genet & Biochem, College Stn, TX 77843 USA. Vilnius State Univ, Dept Chem Phys, LT-2006 Vilnius, Lithuania. RP Kasianowicz, JJ (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Biomol Mat Grp, ACSL 227 A251, Gaithersburg, MD 20899 USA. NR 43 TC 58 Z9 59 U1 0 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 26 PY 2000 VL 16 IS 26 BP 10428 EP 10435 DI 10.1021/la000690k PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 388DG UT WOS:000166161700070 ER PT J AU Jeon, HS Nakatani, AI Han, CC Colby, RH AF Jeon, HS Nakatani, AI Han, CC Colby, RH TI Melt rheology of lower critical solution temperature polybutadiene/polyisoprene blends SO MACROMOLECULES LA English DT Article ID LINEAR VISCOELASTIC BEHAVIOR; MISCIBLE POLYMER BLENDS; INTERFACIAL-TENSION; PHASE-SEPARATION; SHEAR; MORPHOLOGY; MODEL; EMULSIONS; FLOW AB The viscoelastic properties of near critical entangled polybutadiene (PB)/polyisoprene (PI) blends were investigated in oscillatory shear above and below the lower critical solution temperature (LCST). The terminal loss modulus of a near critical PB/PI blend above and below the LCST is well described by means of a log additive mixing rule. A single master curve in the loss modulus of the critical blend exhibiting WLF behavior was obtained above and below the LCST by using the empirical time-temperature superposition (tTS) principle. However, the storage modulus above the LCST deviates from both the tTS principle and the log additive mixing rule. The phase-separated PB/PI blends within the linear viscoelastic regime display higher than expected values of storage modulus at low frequencies, due to the interfacial tension between the two phases of the blend. This increase causes a discontinuity in the temperature dependence of the storage modulus at low frequencies. The discontinuity occurs at a frequency-dependent temperature that extrapolates in the limit of zero frequency to the cloud point measured under quiescent conditions by optical microscopy. The evaluations of interfacial tension from low-frequency linear viscoelasticity are compared with the expectations of Helfand-Tagami theory. The rheological determinations of interfacial tension are within a factor of 2 of the expected values for all compositions except those near the phase-inversion point. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Jeon, HS (reprint author), New Mexico Inst Min & Technol, Dept Chem & Petr Engn, 801 Leroy Pl, Socorro, NM 87801 USA. NR 36 TC 55 Z9 58 U1 1 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 26 PY 2000 VL 33 IS 26 BP 9732 EP 9739 DI 10.1021/ma000714u PG 8 WC Polymer Science SC Polymer Science GA 388PJ UT WOS:000166189900037 ER PT J AU Meredith, JC Smith, AP Karim, A Amis, EJ AF Meredith, JC Smith, AP Karim, A Amis, EJ TI Combinatorial materials science for polymer thin-film dewetting SO MACROMOLECULES LA English DT Article ID DISCOVERY; CATALYSTS; PHOSPHOR; DYNAMICS; PARALLEL; RUPTURE; DEFECTS; LIBRARY AB Combinatorial methods involving data collection in multiparameter space allow a rapid identification of measured property trends as a function of system parameters. The technique has been applied with success to pharmaceutical, inorganic and organic materials synthesis, but not significantly to measurements of polymeric films and coatings. We demonstrate the use of 2-D combinatorial libraries to investigate thin-film dewetting. We have prepared libraries of thin films of polystyrene on silicon substrates containing orthogonal, continuous variations of thickness (h), and temperature (T) that represent about 1200 practical state points per library. The libraries were screened for dewetting behavior using automated optical microscopy. Dewetting trends were visibly apparent on the libraries, and a comprehensive map of the T, h, and time (t) dependence was generated in a few hours. The combinatorial libraries, spanning a large T, h, and t range, not only reproduced known dewetting structures and phenomena but also enabled a novel T, h superposition of the heterogeneous nucleated hole dewetting kinetics. We observed three hole nucleation regimes as a function of thickness: heterogeneously nucleated holes (h > 55 nm), a crossover regime where both heterogeneous and capillary instability nucleation compete (33 nm < h < 55 nm), and a regime of holes nucleated by capillary instability (16 nm < h < 33 nm). C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Div Polymers, 100 Bur Dr Stop 8542, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 37 TC 167 Z9 169 U1 3 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD DEC 26 PY 2000 VL 33 IS 26 BP 9747 EP 9756 DI 10.1021/ma001298g PG 10 WC Polymer Science SC Polymer Science GA 388PJ UT WOS:000166189900039 ER PT J AU Fair, JR Nesbitt, DJ AF Fair, JR Nesbitt, DJ TI Cluster photofragmentation dynamics: Quasiclassical trajectory studies of Ar-n-H2S and Ar-n-SH (n=1,2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; RESOLUTION ELECTRONIC SPECTROSCOPY; FREE-RADICAL CLUSTERS; PREDISSOCIATION DYNAMICS; OH-AR; INTERMOLECULAR VIBRATIONS; COMPLEXES; KR; PHOTODISSOCIATION; FRAGMENTATION AB Quasiclassical trajectory calculations with model potential energy surfaces have been used to elucidate the formation dynamics of open-shell radical clusters by "gentle-recoil" photolysis of closed-shell hydride clusters. Specifically, model surfaces for Ar-H2S and Ar-2-H2S have been constructed and used to explore photofragmentation dynamics at 193 and 248 nm for comparison with previous experimental results. A remarkable efficiency (as high as 25%) for forming highly excited radical Ar-SH and Ar-2-SH clusters is calculated, despite photolysis recoil energies more than 100-fold in excess of the dissociation limit. This surprisingly high survival probability is traced to two dynamical sources. First, ejection of the light H atom from Ar-n-H2S effectively removes all but a small fraction of the excess photolysis energy from the nascent radical cluster in the center-of-mass frame. Second, although trajectory calculations indicate that nearly 50% of the surviving clusters contain energies up to two-fold higher than the dissociation limit, these clusters are classically bound due to novel angular momentum barriers predicted by Pollak [J. Chem. Phys. 86, 1645 (1987)] for a polyatomic system. Finally, an analysis is presented that indicates the "gentle-recoil" photolysis mechanism may permit efficient formation of highly internally excited, chemically reactive radical clusters of OH and SH with light species such as H-2 and D-2. (C) 2000 American Institute of Physics. [S0021- 9606(00)00348-2]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Fair, JR (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 40 TC 10 Z9 10 U1 0 U2 0 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 DEC 22 PY 2000 VL 113 IS 24 BP 10962 EP 10972 DI 10.1063/1.1326066 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 382TZ UT WOS:000165841300015 ER PT J AU Thompson, PE Hobart, KD Twigg, ME Rommel, SL Jin, N Berger, PR Lake, R Seabaugh, AC Chi, P AF Thompson, PE Hobart, KD Twigg, ME Rommel, SL Jin, N Berger, PR Lake, R Seabaugh, AC Chi, P TI Epitaxial Si-based tunnel diodes SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society CY MAY 29-JUN 02, 2000 CL STRASBOURG, FRANCE SP European Mat Res Soc DE tunnel diodes; epitaxy; delta doping; silicon; silicon-germanium ID MOLECULAR-BEAM EPITAXY; SURFACE SEGREGATION; LOW-TEMPERATURES; SI(100); GROWTH; SILICON; SB AB Tunneling devices in combination with transistors offer a way to extend the performance of existing technologies by increasing circuit speed and decreasing static power dissipation. We have investigated Si-based tunnel diodes grown using molecular beam epitaxy (MBE). The basic structure is a p(+) layer formed by B delta doping, an undoped spacer layer, and an n(+) layer formed by Sb delta doping. In the n-on-p configuration, low temperature epitaxy (300-370 degreesC) was used to minimize the effect of dopant segregation and diffusion. In the p-on-n configuration, a combination of growth temperatures from 320 to 550 degreesC was used to exploit the Sb segregation to obtain a low Sb concentration in the B-doped layer. Post-growth rapid thermal anneals for 1 min in the temperature interval between 600 and 825 degreesC were required to optimize the device characteristics. J(p), the peak current density, and the peak-to-valley current ratio (PVCR), were measured at room temperature. An n-on-p diode having a spacer layer composed of 4 nm Si0.6Ge0.4 bounded on either side by 1 nm Si, had a J(p)= 2.3 kA/cm(2) and PVCR = 2.05. A p-on-n tunnel diode with an 8 nm Si spacer (5 nm grown at 320 degreesC, 3 nm grown at 550 degreesC) had a J(p)= 2.6 kA/cm(2) and PVCR = 1.7. (C) 2000 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Delaware, Dept Elect & Comp Engn, Newark, DE 19716 USA. Raytheon Syst Co, Appl Res Lab, Dallas, TX 75243 USA. Univ Notre Dame, Dept Elect Engn, Notre Dame, IN 46556 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Thompson, PE (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Seabaugh, Alan/I-4473-2012; Rommel, Sean/F-9654-2013; Berger, Paul/I-4063-2014 OI Seabaugh, Alan/0000-0001-6907-4129; Rommel, Sean/0000-0001-5996-0813; Berger, Paul/0000-0002-2656-2349 NR 24 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 22 PY 2000 VL 380 IS 1-2 BP 145 EP 150 DI 10.1016/S0040-6090(00)01490-5 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 392CU UT WOS:000166393700039 ER PT J AU Laming, JM Kink, I Takacs, E Porto, JV Gillaspy, JD Silver, EH Schnopper, HW Bandler, SR Brickhouse, NS Murray, SS Barbera, M Bhatia, AK Doschek, GA Madden, N Landis, D Beeman, J Haller, EE AF Laming, JM Kink, I Takacs, E Porto, JV Gillaspy, JD Silver, EH Schnopper, HW Bandler, SR Brickhouse, NS Murray, SS Barbera, M Bhatia, AK Doschek, GA Madden, N Landis, D Beeman, J Haller, EE TI Emission-line intensity ratios in Fe XVII observed with a microcalorimeter on an electron beam ion trap SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; methods : laboratory; stars : individual (Capella); Sun : corona; techniques : spectroscopic; X-rays : general ID X-RAY-SPECTRA; SOLAR-FLARE; ACTIVE-REGION; POLARIZATION; PLASMAS; DENSITY AB We report new observations of emission line intensity ratios of Fe XVII under controlled experimental conditions, using the National Institute of Standards and Technology electron beam ion trap (EBIT) with a microcalorimeter detector. We compare our observations with collisional-radiative models using atomic data computed in distorted wave and R-matrix approximations, which follow the transfer of the polarization of level populations through radiative cascades. Our results for the intensity ratio of the 2p(6) S-1(0)-2p(5)3d P-1(1) 15.014 Angstrom line to the 2p(6) S-1(0)- 2p(5) 3d D-3(1) 15.265 Angstrom line are 2.94 +/- 0.18 and 2.50 +/- 0.13 at beam energies of 900 and 1250 eV, respectively. These results are not consistent with collisional-radiative models and support conclusions from earlier EBIT work at the Lawrence Livermore National Laboratory that the degree of resonance scattering in the solar 15.014 Angstrom line has been overestimated in previous analyses. Further observations assess the intensity ratio of the three lines between the 2p(6)-2p(5)3s configurations to the three lines between the 2p(6)-2p(5)3d configurations. Both R-matrix and distorted wave approximations agree with each other and our experimental results much better than most solar and stellar observations, suggesting that other processes not present in our experiment must play a role in forming the Fe XVII spectrum in solar and astrophysical plasmas. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. MIT, Cambridge, MA 02139 USA. Univ Debrecen, H-4026 Debrecen, Hungary. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron GS Vaiana, I-90134 Palermo, Italy. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Laming, JM (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RI Bandler, Simon/A-6258-2010; OI Bandler, Simon/0000-0002-5112-8106; Brickhouse, Nancy/0000-0002-8704-4473 NR 31 TC 71 Z9 72 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2000 VL 545 IS 2 BP L161 EP L164 DI 10.1086/317876 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 393EL UT WOS:000166456200021 ER PT J AU Vasiliu-Doloc, L Osborn, R Rosenkranz, S Mesot, J Mitchell, JF Sinha, SK Seeck, OH Lynn, JW Islam, Z AF Vasiliu-Doloc, L Osborn, R Rosenkranz, S Mesot, J Mitchell, JF Sinha, SK Seeck, OH Lynn, JW Islam, Z TI Polaron ordering in ferromagnetic colossal magnetoresistive oxides SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 3rd International Conference on Stripes and High Tc Superconductivity (STRIPES 2000) CY SEP 25-30, 2000 CL UNIV ROME LA SPIENZA, ROME, ITALY SP Univ Roma La Sapienza, Ist Nazl Fis Materia, CNR, Grp Nazl Struttra Materia HO UNIV ROME LA SPIENZA ID X-RAY-SCATTERING; NEUTRON-SCATTERING; CHARGE; LA1.2SR1.8MN2O7; LA1-XSRXMNO3; MANGANITES; TRANSITION; DISTORTION; COLLAPSE; STRIPES AB We review our recent x-ray and neutron scattering studies that reveal static diffuse scattering due to polarons in the paramagnetic phase of the colossal magnetoresistive manganites La2-2xSr1+2x,Mn2O7, with x = 0.40 and 0.44. We show that the polarons exhibit short-range incommensurate correlations that grow with decreasing temperature, but disappear abruptly at the combined ferromagnetic and metal-insulator transition in the x = 0.40 system because of the sudden charge delocalization, while persisting at low temperature in the antiferromagnetic x = 0.44 system. The "melting" of the polaron ordering as we cool through Te occurs with the collapse of the polaron scattering itself in the x = 0.40 system. The polaron order is characterized by an ordering wave vector q = (0.3,0,1) that is almost independent of x for x greater than or equal to 0.40, and is consistent with a model of disordered stripes. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Vasiliu-Doloc, L (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. RI Rosenkranz, Stephan/E-4672-2011; Osborn, Raymond/E-8676-2011 OI Rosenkranz, Stephan/0000-0002-5659-0383; Osborn, Raymond/0000-0001-9565-3140 NR 24 TC 1 Z9 1 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 20 PY 2000 VL 14 IS 29-31 BP 3711 EP 3718 DI 10.1142/S021797920000426X PG 8 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 394CW UT WOS:000166507300066 ER PT J AU Carter, MM Elsner, JB Bennett, SP AF Carter, MM Elsner, JB Bennett, SP TI A quantitative precipitation forecast experiment for Puerto Rico SO JOURNAL OF HYDROLOGY LA English DT Article DE atmospheric precipitation; prediction; tropical; model studies ID SCORE; NMC AB A quantitative precipitation forecast (QPF) experiment is conducted for the island of Puerto Rico. The experiment ranks the utility of six objective rainfall models and an operational forecast issued by the National Weather Service Forecast Office, San Juan. This is believed to be the first experiment to rank the utility of rainfall forecast schemes in the tropics. Using an analysis of variance tool called common factor analysis (CFA), the island of Puerto Rico is divided into convective rainfall regions. These regions are statistically independent and represent the forecast domains for the experiment. All forecasts and realizations are area-averaged over each convective region. The QPF experiment is conducted in real-time over three 6-week periods in 1998. The periods fall in three separate rainfall seasons. All seven forecast schemes are configured to produce an area-averaged 24 h rainfall forecast. Forecasts are realized through a network of 114 data rain gauges, whose 24 h values are also area-averaged within convective region. We conduct this experiment in a Bayesian framework. Users may determine the ex ante value of forecast products through the Bayesian correlation score (BCS). Over each of the three seasons, the climatology forecast held the highest ex ante utility for users. Although objective forecast utility scores for heavy rain events are low, they yield higher BCS values than operational forecasts. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Florida State Univ, Dept Geog, Tallahassee, FL 32306 USA. NOAA, Natl Weather Serv, Brownsville, TX 78521 USA. RP Carter, MM (reprint author), Worldwide Weather Trading Co, 20 Exchange Pl,33rd Floor, New York, NY 10005 USA. NR 31 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC 20 PY 2000 VL 239 IS 1-4 BP 162 EP 178 DI 10.1016/S0022-1694(00)00349-8 PG 17 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 384HV UT WOS:000165937500012 ER PT J AU Seo, DJ Perica, S Welles, E Schaake, JC AF Seo, DJ Perica, S Welles, E Schaake, JC TI Simulation of precipitation fields from probabilistic quantitative precipitation forecast SO JOURNAL OF HYDROLOGY LA English DT Article DE probabilistic; quantitative precipitation forecast; ensemble; simulation; precipitation ID REAL-TIME ESTIMATION; RAIN-GAUGE DATA; MODEL; PREDICTION; NMC AB To assimilate Probabilistic Quantitative Precipitation Forecast (PQPF) into ensemble hydrologic forecasting, a procedure is needed that generates ensemble traces of future precipitation fields from PQPF. This paper describes one such procedure used in the National Weather Service's (NWS) Ensemble Precipitation Processor (EPP). Given PQPF for the first 24 h valid at the forecast scale (approximately 64 x 64 km(2)), the procedure generates ensemble traces of 24- or 6-h precipitation at the simulation scale (approximately 4 x 4 km(2)) in space or in space and time, respectively. The steps involved are quasi-analytical downscaling of PQPF and conditional simulation of precipitation fields based on optimal linear estimation techniques that explicitly account for both intermittency and inner variability. To evaluate the procedure. radar-based precipitation data from the Ohio River Forecast Center (OHRFC) are used to develop a climatological PQPF, and to compare ensemble statistics between simulated and observed precipitation. Published by Elsevier Science B.V. C1 NOAA, Natl Weather Serv, Hydrol Lab, Off Hydrol Dev, Silver Spring, MD 20910 USA. RP Seo, DJ (reprint author), Univ Utah, Dept Civil & Environm Engn, Salt Lake City, UT 84112 USA. NR 34 TC 24 Z9 25 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC 20 PY 2000 VL 239 IS 1-4 BP 203 EP 229 DI 10.1016/S0022-1694(00)00345-0 PG 27 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 384HV UT WOS:000165937500014 ER PT J AU Antolik, MS AF Antolik, MS TI An overview of the National Weather Service's centralized statistical quantitative precipitation forecasts SO JOURNAL OF HYDROLOGY LA English DT Article DE statistical weather forecasts; model output statistics; objective precipitation forecasting ID MODEL; PROBABILITIES; SYSTEM AB The current operational statistical quantitative precipitation forecast (QPF) system of the US National Weather Service (NWS) is described, This system produces categorical QPF for stations within the contiguous US and Alaska, and utilizes the Model Output Statistics (MOS) technique applied to output from the NWS Nested Grid Model (NGM). Operational forecasts from this system improve significantly over the gridpoint precipitation forecasts available directly from the NGM. Although most NGM QPF guidance is disseminated to forecasters in categorical form, the categorical forecasts are based on probabilistic information produced by the MOS regression equations. This probabilistic information is shown to have significant skill relative to forecasts produced by using climatic variables, and expected-value estimates from the set of NGM MOS probabilities show promise in helping to fine-tune the categorical forecasts. Since the development of the NGM MOS QPF system, advances in computer processing power have enabled the more frequent introduction and enhancement of operational numerical weather prediction models. Precipitation estimates have evolved as well, with traditional manual observations being replaced by a network of automated observing sites and radar-based estimates. These changes mean that future MOS systems will need to be based on short and potentially unstable samples of model output and predictand data. Strategies for adapting the MOS technique to this environment are discussed. Skillful MOS guidance still can be produced under these conditions, as an experimental QPF system based on a limited sample of data from the NWS eta-coordinate model has shown. Results from these experiments are described, as well as the ongoing development of MOS QPF guidance based on the NWS Global Spectral Model. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Weather Serv, Off Syst Dev, Tech Dev Lab, Silver Spring, MD 20910 USA. RP Antolik, MS (reprint author), NOAA, Natl Weather Serv, Off Syst Dev, Tech Dev Lab, 1325 East West Highway,Room 10378, Silver Spring, MD 20910 USA. NR 41 TC 39 Z9 44 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC 20 PY 2000 VL 239 IS 1-4 BP 306 EP 337 DI 10.1016/S0022-1694(00)00361-9 PG 32 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 384HV UT WOS:000165937500020 ER PT J AU Sundberg, EJ Urrutia, M Braden, BC Isern, J Tsuchiya, D Fields, BA Malchiodi, EL Tormo, J Schwarz, FP Mariuzza, RA AF Sundberg, EJ Urrutia, M Braden, BC Isern, J Tsuchiya, D Fields, BA Malchiodi, EL Tormo, J Schwarz, FP Mariuzza, RA TI Estimation of the hydrophobic effect in an antigen-antibody protein-protein interface SO BIOCHEMISTRY LA English DT Article ID X-RAY-DIFFRACTION; CAVITY-CREATING MUTATIONS; STRUCTURAL-ANALYSIS; MOLECULAR-BASIS; GROWTH-HORMONE; HUMAN LYSOZYME; AMINO-ACIDS; T4 LYSOZYME; FREE-ENERGY; BINDING AB Antigen-antibody complexes provide useful models for analyzing the thermodynamics of protein-protein association reactions. We have employed site-directed mutagenesis, X-ray crystallography, and isothermal titration calorimetry to investigate the role of hydrophobic interactions in stabilizing the complex between the Fv fragment of the anti-hen egg white lysozyme (HEL) antibody D1.3 and HEL. Crystal structures of six FvD1.3-HEL mutant complexes in which an interface tryptophan residue (V(L)W92) has been replaced by residues with smaller side chains (alanine, serine, valine, aspartate, histidine, and phenylalanine) were determined to resolutions between 1.75 and 2.00 Angstrom. In the wild-type complex, V(L)W92 occupies a large hydrophobic pocket on the surface of HEL and constitutes an energetic "hot spot" for antigen binding. The losses in apolar buried surface area in the mutant complexes, relative to wild-type, range from 25 (V(L)F92) to 115 Angstrom (2) (V(L)A92), with no significant shifts in the positions of protein atoms at the mutation site for any of the complexes except V(L)A92, where there is a peptide flip. The affinities of the mutant Fv fragments for HEL are 10-100-fold lower than that of the original antibody. Formation of all six mutant complexes is marked by a decrease in binding enthalpy that exceeds the decrease in binding free energy, such that the loss in enthalpy is partly offset by a compensating gain in entropy. No correlation was observed between decreases in apolar, polar, or aggregate (sum of the apolar and polar) buried surface area in the V(L)92 mutant series and changes in the enthalpy of formation. Conversely, there exist linear correlations between losses of apolar buried surface and decreases in binding free energy (R-2 = 0.937) as well as increases in the solvent portion of the entropy of binding (R-2 = 0.909). The correlation between binding free energy and apolar buried surface area corresponds to 21 cal mol(-1) Angstrom (-2) (1 cal = 4.185 J) for the effective hydrophobicity at the V(L)92 mutation site. Furthermore, the slope of the line defined by the correlation between changes in binding free energy and solvent entropy approaches unity, demonstrating that the exclusion of solvent from the binding interface is the predominant energetic factor in the formation of this protein complex. Our estimate of the hydrophobic contribution to binding at site V(L)92 in the D1.3-HEL interface is consistent with values for the hydrophobic effect derived from classical hydrocarbon solubility models. We also show how residue V(L)W92 can contribute significantly less to stabilization when buried in a more polar pocket, illustrating the dependence of the hydrophobic effect on local environment at different sites in a protein-protein interface. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. Bowie State Univ, Bowie, MD 20715 USA. Univ Buenos Aires, Fac Farm & Bioquim, CONICET,Catedra Inmunol, Inst Estudios Inmunidad Humoral, RA-1113 Buenos Aires, DF, Argentina. RP Mariuzza, RA (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. OI Malchiodi, Emilio/0000-0001-7501-3330 FU NIGMS NIH HHS [GM52801] NR 55 TC 74 Z9 74 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 19 PY 2000 VL 39 IS 50 BP 15375 EP 15387 DI 10.1021/bi000704l PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 383GV UT WOS:000165875500010 PM 11112523 ER PT J AU Borchers, JA Ijiri, Y Lind, DM Ivanov, PG Erwin, RW Qasba, A Lee, SH O'Donovan, KV Dender, DC AF Borchers, JA Ijiri, Y Lind, DM Ivanov, PG Erwin, RW Qasba, A Lee, SH O'Donovan, KV Dender, DC TI Detection of field-dependent antiferromagnetic domains in exchange-biased Fe3O4/NiO superlattices SO APPLIED PHYSICS LETTERS LA English DT Article ID MAGNETORESISTIVE SENSORS; THIN-FILMS; MODEL; STABILIZATION; INTERFACES; BILAYERS AB Neutron diffraction studies of Fe3O4/NiO superlattices reveal that the field dependence of domains in the antiferromagnetic NiO is correlated with the presence or absence of exchange biasing. Measurements of the full width at half maximum of the (111) NiO reflection show that after cooling in zero field, the antiferromagnetic domain size both parallel and perpendicular to the growth axis is sensitive to the strength of the applied field. In contrast, after cooling from room temperature in a field of 5 T, the domain size is generally smaller than the zero-field-cooled value and does not vary with field. These data suggest that exchange biasing originates from domain walls frozen into the antiferromagnet upon field cooling. (C) 2000 American Institute of Physics. [S0003-6951(00)00352-1]. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Oberlin Coll, Dept Phys, Oberlin, OH 44074 USA. Florida State Univ, Dept Phys, MARTECH, Tallahassee, FL 32306 USA. RP Borchers, JA (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 25 TC 25 Z9 25 U1 0 U2 9 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 DEC 18 PY 2000 VL 77 IS 25 BP 4187 EP 4189 DI 10.1063/1.1333684 PG 3 WC Physics, Applied SC Physics GA 382LR UT WOS:000165824200036 ER PT J AU Williams, J Roberts, JM Bertman, SB Stroud, CA Fehsenfeld, FC Baumann, K Buhr, MP Knapp, K Murphy, PC Nowick, M Williams, EJ AF Williams, J Roberts, JM Bertman, SB Stroud, CA Fehsenfeld, FC Baumann, K Buhr, MP Knapp, K Murphy, PC Nowick, M Williams, EJ TI A method for the airborne measurement of PAN, PPN, and MPAN SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PEROXYACETYL NITRATE PAN; GAS-CHROMATOGRAPHIC DETERMINATION; ORGANIC NITRATES; BIOGENIC HYDROCARBONS; NITROGEN-DIOXIDE; UNITED-STATES; AMBIENT AIR; PEROXYISOBUTYRYL NITRATE; REGIONAL OZONE; CAPILLARY AB An aircraft-based instrument for the measurement of peroxyacetic nitric anhydride (PAN) and related compounds peroxypropionic nitric anhydride (PPN), and peroxymethacrylic nitric anhydride (MPAN) is described. The instrument functions by direct injection of a small sample (2 ambient cm(3)) into a wide bore fused silica capillary gas chromatographic separation column with subsequent detection by electron capture. The efficiency of separation and early elution of water made possible a sampling frequency of once every 5 min. The selective destruction of PAN type compounds at 125 degreesC in actual ambient samples showed that no interfering species were present. Calibration of the instrument was accomplished by the total odd-nitrogen (NO) measurement of air mixtures of high-purity PANs. Inflight calibrations of PAN in either thermally decomposed ambient air or dry zero air showed that the sensitivity of the instrument to PAN was not affected by other matrix species such as carbon dioxide or water. The instrument response to PPN and MPAN relative to that of PAN was consistent (within 5%) over the span of several months. The instrument response to PAN was linear up to 3.5 ppbv and the slope of the response versus [PAN] indicated a relative standard deviation of 2% over the course of a 30-day field study. The detection limits of the method for PAN and PPN were estimated to be 5 pptv (3s) based on the uncertainty of peak detection. The overall accuracy of the PAN measurement was estimated to be +/-(5 pptv+15%) in one campaign and +/-(5 pptv+20%) in others. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80305 USA. Univ Colorado, Boulder, CO 80309 USA. RP Williams, J (reprint author), Max Planck Inst Chem, D-55020 Mainz, Germany. RI Roberts, James/A-1082-2009; Fehsenfeld, Frederick/I-4876-2013 OI Roberts, James/0000-0002-8485-8172; NR 53 TC 49 Z9 50 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 16 PY 2000 VL 105 IS D23 BP 28943 EP 28960 DI 10.1029/2000JD900373 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 389UQ UT WOS:000166257400006 ER PT J AU Waddell, E Wang, Y Stryjewski, W McWhorter, S Henry, AC Evans, D McCarley, RL Soper, SA AF Waddell, E Wang, Y Stryjewski, W McWhorter, S Henry, AC Evans, D McCarley, RL Soper, SA TI High-resolution near-infrared imaging of DNA microarrays with time-resolved acquisition of fluorescence lifetimes SO ANALYTICAL CHEMISTRY LA English DT Article ID SINGLE-NUCLEOTIDE POLYMORPHISMS; PHOTON COUNTING INSTRUMENT; OLIGONUCLEOTIDE ARRAYS; DIODE-LASER; CAPILLARY ELECTROPHORESIS; SEQUENCING APPLICATIONS; TRICARBOCYANINE DYES; MOLECULE DETECTION; IDENTIFICATION; HYBRIDIZATION AB Ultrasensitive, near-infrared (NIR), time-resolved fluorescence is evaluated as a detection method for reading DNA hybridization events on solid surfaces for microarray applications. In addition, the potential of mulitiplexed analyses using time-resolved identification protocols is described. To carry out this work, a NIR time-resolved confocal imager was constructed to read fluorescence signatures from the arrays. The device utilized a 780-nm pulsed diode laser, a single-photon avalanche diode (SPAD), and a high-numerical-aperture microscope objective mounted in an epi-illumination format. Due to the small size of the components that are required to con; struct this imager, the entire detector could easily be mounted on high-resolution translational stages and scanned over the stationary arrays. The instrument response function of the device was determined to be 275 ps (fwhm), which is adequate for measuring fluorophores with subnanosecond lifetimes, To characterize the system, NIR dyes were deposited directly on different substrate materials typically used for DNA microarrays, and the fluorescence lifetimes of two representative dyes were measured. The fluorescence lifetime for aluminum tetrasulfonated naphthalocyanine was found to be 1.92 ns, and a value of 1.21 ns was determined for the tricarbocyanine dye, IRD800, when it was deposited onto poly(methyl methacrylate) (PMMA) and measured in the dry state. Finally, the imager was used to monitor hybridization events using probe oligonucleotides chemically tethered to a PMMA substrate via a glutardialdehyde linkage to an aminated-PMMA surface. The limit of detection for oligonucleotides containing a NIR fluorescent reporter was determined to be 0.38 molecules/mum(2), with this detection limit improving by a factor of 10 when a time-gate was implemented. Fluorescence lifetime analysis of the hybridization events on PMMA indicated a lifetime value of 1.23 ns for the NIR-labeled oligonucleotides when using maximum-likelihood estimators. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Radius Biosci, Medfield, MA USA. RP McCarley, RL (reprint author), NIST, Gaithersburg, MD 20899 USA. RI McCarley, Robin/F-4483-2014 OI McCarley, Robin/0000-0002-4769-552X FU NCI NIH HHS [R23-CA84625]; PHS HHS [R01-01499] NR 43 TC 68 Z9 68 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 2000 VL 72 IS 24 BP 5907 EP 5917 DI 10.1021/ac0009705 PG 11 WC Chemistry, Analytical SC Chemistry GA 383JT UT WOS:000165879900007 PM 11140756 ER PT J AU Barker, SLR Ross, D Tarlov, MJ Gaitan, M Locascio, LE AF Barker, SLR Ross, D Tarlov, MJ Gaitan, M Locascio, LE TI Control of flow direction in microfluidic devices with polyelectrolyte multilayers SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARIES; ELECTROPHORESIS AB Electroosmotic flow (EOF) is commonly utilized in microfluidics. Because the direction of the EOF can be determined by the substrate surface charge, control of the surface chemical state offers the potential, in addition to voltage control, to direct the flow in microfluidic devices. We report the use of polyelectrolyte multilayers (PEMs) to alter the surface charge and control the direction of how in polystyrene and acrylic microfluidic devices. Relatively complex now patterns with simple arrangements of applied voltages are realized by derivatization of different arms of a single device with oppositely charged polyelectrolytes. In addition, flow in opposite directions in the same channel is possible. A positively derivatized plastic substrate with a negatively charged lid was used to achieve top-bottom opposite flows. Derivatization of the two sides of a plastic microchannel with oppositely charged polyelectrolytes was used to achieve side-by-side opposite flows. The flow is characterized using fluorescence imaging and particle velocimetry. C1 NIST, Gaithersburg, MD 20899 USA. RP Barker, SLR (reprint author), NIST, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 21 TC 138 Z9 141 U1 3 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 2000 VL 72 IS 24 BP 5925 EP 5929 DI 10.1021/ac0008690 PG 5 WC Chemistry, Analytical SC Chemistry GA 383JT UT WOS:000165879900009 PM 11140758 ER PT J AU Knipp, DJ Lin, CH Emery, BA Ruohoniemi, JM Rich, FJ Evans, DS AF Knipp, DJ Lin, CH Emery, BA Ruohoniemi, JM Rich, FJ Evans, DS TI Hemispheric asymmetries in ionospheric electrodynamics during the solar wind void of 11 May 1999 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; LATITUDE AB We use the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure to produce composite maps of high-latitude ionospheric parameters for II May 1999. On that day there was a near void in the solar wind momentum flux. Yet, focused high-latitude interactions occurred at Earth. Our maps of convection, Joule heating, particle precipitating power and field-aligned current show a striking asymmetry between hemispheres. In the latter three parameters there is at least a five-fold difference in values between the hemispheres. The northern hemisphere polar cap particle precipitation is the strongest we have ever mapped. Strong electrodynamic interactions were focused above 70 degrees north magnetic latitude. In the southern hemisphere only weak, irregular patterns are mapped. We attribute these differences to the strong interplanetary magnetic field spiral configuration, the sunward tilt of the northern hemisphere and the direct beam or "strahl" of solar electrons impinging on the northern polar cap during the momentum void. C1 USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. Natl Cent Univ, Chungli 32054, Taiwan. NCAR, High Altitude Observ, Boulder, CO 80301 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Space Vehicles Directorate, Hanscom AFB, MA USA. Space Environm Ctr, Boulder, CO 80303 USA. RP Knipp, DJ (reprint author), USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. NR 6 TC 4 Z9 4 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 DEC 15 PY 2000 VL 27 IS 24 BP 4013 EP 4016 DI 10.1029/2000GL003801 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 390TB UT WOS:000166311700013 ER PT J AU Wu, W Lin, EK Lin, QH Angelopolous, M AF Wu, W Lin, EK Lin, QH Angelopolous, M TI Small angle neutron scattering measurements of nanoscale lithographic features SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; X-RAY-LITHOGRAPHY; SIDEWALL ROUGHNESS; EDGE-ROUGHNESS; COLD NEUTRONS; GRATINGS; PMMA AB State-of-the-art lithographic techniques are able to fabricate structures for the semiconductor and other nanofabrication industries with dimensions below 150 nm. The relentless drive to further miniaturize semiconductor devices has placed increasingly stringent demands on current microscopy-based techniques for precisely measuring the size and the quality (line-edge roughness) of lithographically produced features. Using newly developed neutron optics, we demonstrate the first application of small-angle neutron scattering to nondestructively and quantitatively measure both the dimension and the quality of 150 nm lines fabricated on single crystal silicon wafers. (C) 2000 American Institute of Physics. [S0021-8979(00)07524-1]. C1 Natl Inst Stand & Technol, Div Polymers, MSEL, Gaithersburg, MD 20899 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Wu, W (reprint author), Natl Inst Stand & Technol, Div Polymers, MSEL, Gaithersburg, MD 20899 USA. EM wenli@nist.gov NR 11 TC 6 Z9 6 U1 0 U2 2 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 DEC 15 PY 2000 VL 88 IS 12 BP 7298 EP 7303 AR PII [S0021-8979(00)07524-1] DI 10.1063/1.1324688 PG 6 WC Physics, Applied SC Physics GA 377UD UT WOS:000165543900053 ER PT J AU Abdulaev, NG Ngo, T Chen, RW Lu, ZJ Ridge, KD AF Abdulaev, NG Ngo, T Chen, RW Lu, ZJ Ridge, KD TI Functionally discrete mimics of light-activated rhodopsin identified through expression of soluble cytoplasmic domains SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROTEIN-COUPLED RECEPTORS; C-TERMINAL PEPTIDES; CONNECTING HELIX-C; F LOOP REGION; ESCHERICHIA-COLI; BOVINE RHODOPSIN; DEPENDENT PHOSPHORYLATION; CONSTITUTIVE ACTIVATION; CONFORMATIONAL-CHANGES; TRANSDUCIN ACTIVATION AB Numerous studies on the seven-helix receptor rhodopsin have implicated the cytoplasmic loops and carboxyl-terminal region in the binding and activation of proteins involved in visual transduction and desensitization. In our continuing studies on rhodopsin folding, assembly, and structure, we have attempted to reconstruct the interacting surface(s) for these proteins by inserting fragments corresponding to the cytoplasmic loops and/or the carboxyl-terminal tail of bovine opsin either singly, or in combination, onto a surface loop in thioredoxin. The purpose of the thioredoxin fusion is to provide a soluble scaffold for the cytoplasmic fragments thereby allowing them sufficient conformational freedom to fold to a structure that mimics the protein-binding sites on light-activated rhodopsin. All of the fusion proteins are expressed to relatively high levels in Escherichia coli and can be purified using a two- or three-step chromatography procedure. Biochemical studies show that some of the fusion proteins effectively mimic the activated conformation(s) of rhodopsin in stimulating G-protein or competing with the light-activated rhodopsin/G-protein interaction, in supporting phosphorylation of the carboxyl-terminal opsin fragment by rhodopsin kinase, and/or phosphopeptide-stimulated arrestin binding. These results suggest that specific segments of the cytoplasmic surface of rhodopsin can adopt functionally discrete conformations in the absence of the connecting transmembrane helices and retinal chromophore. C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Rockville, MD 20850 USA. Genet Inst Inc, Cambridge, MA 02140 USA. RP Ridge, KD (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. FU NEI NIH HHS [EY11112] NR 89 TC 36 Z9 36 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD DEC 15 PY 2000 VL 275 IS 50 BP 39354 EP 39363 DI 10.1074/jbc.M005642200 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 384PB UT WOS:000165953100058 PM 10988291 ER PT J AU Xu, HHK Smith, DT Schumacher, GE Eichmiller, FC AF Xu, HHK Smith, DT Schumacher, GE Eichmiller, FC TI Whisker-reinforced dental core buildup composites: Effect of filler level on mechanical properties SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE dental composites; core buildup; ceramic whisker reinforcement; filler level; strength; toughness; indentation; modulus ID SILICON-NITRIDE; HUMAN ENAMEL; INDENTATION; FATIGUE; RESTORATIONS; HARDNESS; NANOINDENTATION; STRENGTH; BEHAVIOR; AMALGAM AB The strength and toughness of dental core buildup composites in large stress-bearing restorations need to be improved to reduce the incidence of fracture due to stresses from chewing and clenching. The aims of the present study-were to develop novel core buildup composites reinforced with ceramic whiskers, to examine the effect of filler level, and to investigate the reinforcement mechanisms. Silica particles were fused onto the whiskers to facilitate silanization and to roughen the whisker surface for improved retention in the matrix. Filler level was varied from 0 to 70%. Flexural strength, compressive strength, and fracture toughness of the composites were measured. A nanoindentation system was used to measure elastic modulus and,hardness. Scanning electron microscopy (SEM) was used to examine the fracture surfaces of specimens. Whisker filler level had significant effects on composite properties. The flexural strength in MPa (mean +/- SD; n = 6) increased from (95 +/- 15) for the unfilled resin to (193 +/- 8) for the composite with 50% filler level, then slightly decreased to (176 +/- 12) at 70% filler level. The compressive strength increased from (149 +/- 33) for the unfilled resin to (282 +/- 48) at 10% filler level, and remained equivalent from 10 to 70% filler level. Both the modulus and hardness increased monotonically with filler level. Ln conclusion, silica particle-fused ceramic single-crystalline whiskers significantly reinforced dental core buildup composites. The reinforcement mechanisms appeared to be crack deflection and bridging by the whiskers. Whisker filler level had significant effects on the flexural strength, compressive strength, elastic modulus, and hardness of composites. (C) 2000 John Wiley & Sons, Inc. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, 100 Bur Dr Stop 8546,Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 FU NIDCR NIH HHS [R29 DE12476] NR 48 TC 12 Z9 12 U1 0 U2 3 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 DEC 15 PY 2000 VL 52 IS 4 BP 812 EP 818 PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 358UY UT WOS:000089576600026 PM 11033564 ER PT J AU Robbins, JA Holmes, C Halley, R Bothner, M Shinn, E Graney, J Keeler, G tenBrink, M Orlandini, KA Rudnick, D AF Robbins, JA Holmes, C Halley, R Bothner, M Shinn, E Graney, J Keeler, G tenBrink, M Orlandini, KA Rudnick, D TI Time-averaged fluxes of lead and fallout radionuclides to sediments in Florida Bay SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID UNITED-STATES; CS-137; PLUTONIUM; MOBILITY; PB-210; PU; DIAGENESIS; TRANSPORT; GASOLINE; PU-239,PU-240 AB Recent, unmixed sediments from mud banks of central Florida Bay were dated using Pb-210/Ra-226, and chronologies were verified by comparing sediment lead temporal records with Pb/Ca ratios in annual layers of coral (Montastrea annularis) located on the ocean side of the Florida Keys. Dates of sediment lead peaks (1978 +/- 2) accord with prior observations of a 6 year lag between the occurrence of maximum atmospheric lead in 1972 and peak coral lead in 1978. Smaller lags of 1-2 years occur between the maximum atmospheric radionuclide fallout and peaks in sediment temporal records of Cs-137 and Pu. Such lags are consequences of system time averaging (STA) in which atmospherically delivered particle-associated constituents accumulate and mix in a (sedimentary?) reservoir before transferring to permanent sediments and coral. STA model calculations, using time-dependent atmospheric inputs, produced optimized profiles in excellent accord with measured sediment 137Cs, Pu, lead, and coral lead distributions. Derived residence times of these particle tracers (16 +/- 1, 15.7 +/- 0.7, 19 +/- 3, and 16 +/- 2 years, respectively) are comparable despite differences in sampling locations, in accumulating media, and in element loading histories and geochemical properties. For a 16 year weighted mean residence time, STA generates the observed 6 year lead peak lag. Evidently, significant levels of nondegradable, particle-associated contaminants can persist in Florida Bay for many decades following elimination of external inputs. Present results, in combination with STA model analysis of previously reported radionuclide profiles, suggest that decade-scale time averaging may occur widely in recent coastal marine sedimentary environments. C1 NOAA, Great Lakes Environm Res Lab, US Dept Commerce, Ann Arbor, MI 48105 USA. US Geol Survey, Ctr Coastal & Reg Marine Geol, St Petersburg, FL 33701 USA. US Geol Survey, Woods Hole Field Ctr, Marine & Coastal Program, Woods Hole, MA 02543 USA. Univ Michigan, Dept Environm & Ind Hlth, Sch Publ Hlth, Ann Arbor, MI 48109 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. S Florida Water Management Dist, W Palm Beach, FL 33146 USA. RP Robbins, JA (reprint author), NOAA, Great Lakes Environm Res Lab, US Dept Commerce, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 71 TC 39 Z9 39 U1 3 U2 7 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 DEC 15 PY 2000 VL 105 IS C12 BP 28805 EP 28821 DI 10.1029/1999JC000271 PG 17 WC Oceanography SC Oceanography GA 388XR UT WOS:000166208800019 ER PT J AU Cockayne, E AF Cockayne, E TI Generation of quasicrystals via a single cluster SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7th International Conference on Quasicrystals (ICQ7) CY SEP 20-24, 1999 CL UNIV STUTTGART, STUTTGART, GERMANY SP German Sci Fdn, State Baden Wurttemberg, Minist Sci Res & Culture, Univ Tubingen, Max Planck Inst Met Res, Landesbank Baden Wurttemberg, Volksbank Trossingen HO UNIV STUTTGART DE quasicrystals; decagonal clusters ID DECAGONAL QUASI-CRYSTAL; MODEL AB We present a columnar cluster with 46 atoms per repeat distance which forces a quasicrystal when space is filled by interpenetrating copies of itself. The atomic positions in the resultant quasicrystal are remarkably similar to those in models for real decagonal quasicrystals. The axes of the pentagonal antiprism subclusters of this model reveal an even simpler tile decoration, with only three atoms, that forces a quasicrystal under certain constraints. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Cockayne, E (reprint author), Natl Inst Stand & Technol, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 10 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2000 VL 294 SI SI BP 224 EP 227 DI 10.1016/S0921-5093(00)01304-6 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 388HW UT WOS:000166175900050 ER PT J AU Widom, M Al-Lehyani, I Wang, Y Cockayne, E AF Widom, M Al-Lehyani, I Wang, Y Cockayne, E TI Ab initio energetics of transition metal ordering in decagonal Al-Co-Cu SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7th International Conference on Quasicrystals (ICQ7) CY SEP 20-24, 1999 CL UNIV STUTTGART, STUTTGART, GERMANY SP German Sci Fdn, State Baden Wurttemberg, Minist Sci Res & Culture, Univ Tubingen, Max Planck Inst Met Res, Landesbank Baden Wurttemberg, Volksbank Trossingen HO UNIV STUTTGART DE decagonal quasicrystal; Al-Co-Cu; ab initio AB We perform ab initio total energy calculations fur approximants to a model of decagonal Al-Co-Cu. These calculations support previously proposed chemical ordering of Co and Cu atoms along tile edges. Preferred arrow orientations are identified and shown to obey a subset of the single-arrow Penrose matching rules. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Piittsburgh Supercomp Ctr, Pittsburgh, PA 15213 USA. NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Widom, M (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI Widom, Michael/P-2531-2014 OI Widom, Michael/0000-0001-5972-5696 NR 9 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2000 VL 294 SI SI BP 295 EP 298 DI 10.1016/S0921-5093(00)01215-6 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 388HW UT WOS:000166175900067 ER PT J AU Jach, T AF Jach, T TI Quasicrystal element correlations from X-ray standing waves SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7th International Conference on Quasicrystals (ICQ7) CY SEP 20-24, 1999 CL UNIV STUTTGART, STUTTGART, GERMANY SP German Sci Fdn, State Baden Wurttemberg, Minist Sci Res & Culture, Univ Tubingen, Max Planck Inst Met Res, Landesbank Baden Wurttemberg, Volksbank Trossingen HO UNIV STUTTGART DE quasicrystal; X-ray standing wave; dynamical diffraction ID DYNAMICAL DIFFRACTION; ICOSAHEDRAL PHASE; QUASI-CRYSTAL; ALPDMN AB X-ray standing waves associated with dynamical diffraction in perfect crystals are also present during diffraction in high-quality quasicrystals. The fluorescence observed from quasicrystals while scanning the rocking curve of a particular Bragg reflection shows an identical form to that observed from periodic planes in a perfect crystal. In this case, however, the coherent fraction is the value of a correlation function: the Fourier component of a given elemental distribution at the wavevector associated with the Bragg peak. We show, using a model fur Al-Pd-Mn, how the observed value for the coherent position at a given reflection is a sensitive indicator of the centrosymmetry of the distribution, and the observed value for the coherent fraction is a test of the elemental distribution predicted from the model. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jach, T (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2000 VL 294 SI SI BP 315 EP 318 DI 10.1016/S0921-5093(00)01181-3 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 388HW UT WOS:000166175900071 ER PT J AU Cappello, G Dechelette, A Schmithusen, F Decossas, S Chevrier, J Comin, F Formoso, V de Boissieu, M Jack, T Colella, R Lograsso, TA Jenks, C AF Cappello, G Dechelette, A Schmithusen, F Decossas, S Chevrier, J Comin, F Formoso, V de Boissieu, M Jack, T Colella, R Lograsso, TA Jenks, C TI Bulk and surface evidence for the long-range spatial modulation of X-ray absorption in the Al-Pd-Mn quasicrystal at Bragg incidence SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7th International Conference on Quasicrystals (ICQ7) CY SEP 20-24, 1999 CL UNIV STUTTGART, STUTTGART, GERMANY SP German Sci Fdn, State Baden Wurttemberg, Minist Sci Res & Culture, Univ Tubingen, Max Planck Inst Met Res, Landesbank Baden Wurttemberg, Volksbank Trossingen HO UNIV STUTTGART DE quasicrystal; X-ray diffraction; X-ray standing wave; surfaces ID STANDING WAVES; ALPDMN; DIFFRACTION; SYMMETRY AB An X-ray standing waves experiment was performed at the ID32 beam line of the ESRF on an Al-Pd-Mn quasicrystal with the X-ray beam at normal incidence. The X-ray photoemission core levels for each element were recorded to probe the surface. The drain current, i.e. the electron current from ground needed to neutralize the irradiated sample and to compensate the photoemitted electrons was also recorded as a bulk probe that integrates over all atoms of the sample. Within the two-beam approximation applied to quasicrystals, a simple analysis of this effect is proposed. This provides a direct-space illustration of the diffraction process in a quasiperiodic structure. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CNRS, LEPES, F-38042 Grenoble 9, France. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Inst Natl Polytech Grenoble, LTPCM, F-38402 St Martin Dheres, France. NIST, Gaithersburg, MD 20899 USA. Purdue Univ, W Lafayette, IN 47907 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Chevrier, J (reprint author), CNRS, LEPES, BP 166, F-38042 Grenoble 9, France. EM chevrier@esrf.fr RI Chevrier, Joel/D-3280-2012; OI Chevrier, Joel/0000-0001-5609-6863 NR 11 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2000 VL 294 SI SI BP 863 EP 866 DI 10.1016/S0921-5093(00)01080-7 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 388HW UT WOS:000166175900200 ER PT J AU Boisvert, R Dyksen, W Houstis, E AF Boisvert, R Dyksen, W Houstis, E TI 1999 International Symposium on Computational Sciences, to honor John R. Rice - Preface SO MATHEMATICS AND COMPUTERS IN SIMULATION LA English DT Editorial Material C1 Natl Inst Stand & Technol, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. Purdue Univ, Dept Comp Sci, W Lafayette, IN 47807 USA. Univ Nebraska, Coll IS&T, Omaha, NE 68182 USA. RP Houstis, E (reprint author), Natl Inst Stand & Technol, Math & Computat Sci Div, 100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. OI Boisvert, Ronald/0000-0002-4445-1044 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4754 J9 MATH COMPUT SIMULAT JI Math. Comput. Simul. PD DEC 15 PY 2000 VL 54 IS 4-5 BP 223 EP 223 DI 10.1016/S0378-4754(00)00183-X PG 1 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 386FT UT WOS:000166050700001 ER PT J AU Boisvert, RF AF Boisvert, RF TI Mathematical software: past, present, and future SO MATHEMATICS AND COMPUTERS IN SIMULATION LA English DT Article; Proceedings Paper CT International Symposium on Computational Sciences to honor John R Rice CY MAY 22-26, 1999 CL W LAFAYETTE, INDIANA SP Purdue Univ, Dept Comp Sci, Int Federat Informat Processing, Working Grp 2 5, Int Assoc Math & Comp Simulat DE mathematical software; numerical computing; history of computing ID PARTIAL-DIFFERENTIAL EQUATIONS; LINEAR ALGEBRA SUBPROGRAMS; SCIENTIFIC SOFTWARE; COLLOCATION; PERFORMANCE; LIBRARIES; DOMAINS; SYSTEM; ORDER; SET AB This paper provides some reflections on the field of mathematical software on the occasion of John Rice's 65th birthday. I describe some of the common themes of research in this field and recall some significant events in its evolution. Finally, I raise a number of issues that are of concern to future developments. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Informat Technol Lab, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. RP Boisvert, RF (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Math & Computat Sci Div, Stop 8910,100 Bur Dr, Gaithersburg, MD 20899 USA. OI Boisvert, Ronald/0000-0002-4445-1044 NR 81 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4754 J9 MATH COMPUT SIMULAT JI Math. Comput. Simul. PD DEC 15 PY 2000 VL 54 IS 4-5 BP 227 EP 241 DI 10.1016/S0378-4754(00)00185-3 PG 15 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 386FT UT WOS:000166050700003 ER PT J AU Hyman, RA Stiles, MD Zangwill, A AF Hyman, RA Stiles, MD Zangwill, A TI Gradient search method for orbital-dependent density-functional calculations SO PHYSICAL REVIEW B LA English DT Article ID EFFECTIVE-POTENTIAL METHOD; LOCAL-SPIN-DENSITY; EXACT EXCHANGE; APPROXIMATION; SEMICONDUCTORS; ENERGY; ATOMS AB We describe a gradient search method appropriate for electronic structure problems where the energy functionals are explicitly orbital dependent. The ground state is found by minimizing the total energy with respect to the scalar and vector potentials that enter the Kohn-Sham equations. The method is exact in principle and provides an alternative to the conventional procedure that requires the numerical solution of an integral equation. We demonstrate the method for atoms with spherical effective potentials using (i) a local-spin-density functional that does not depend explicitly on the orbitals and (ii) an exact exchange functional that does depend explicitly on the orbitals. C1 Depaul Univ, Dept Phys, Chicago, IL 60614 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Hyman, RA (reprint author), Depaul Univ, Dept Phys, Chicago, IL 60614 USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 20 TC 9 Z9 9 U1 0 U2 0 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 DEC 15 PY 2000 VL 62 IS 23 BP 15521 EP 15526 DI 10.1103/PhysRevB.62.15521 PG 6 WC Physics, Condensed Matter SC Physics GA 385GK UT WOS:000165995100053 ER PT J AU Kautz, RL Keller, MW Martinis, JM AF Kautz, RL Keller, MW Martinis, JM TI Noise-induced leakage and counting errors in the electron pump SO PHYSICAL REVIEW B LA English DT Article ID COULOMB-BLOCKADE ELECTROMETER; SELF-ORGANIZED CRITICALITY; TUNNELING DEVICES; METROLOGICAL ACCURACY; CURRENT STANDARDS; CHARGE NOISE; 1/F NOISE; TRANSISTOR; JUNCTIONS; FABRICATION AB Computer simulations reveal that the lowest rates of leakage and counting errors observed in the electron pump can be explained by photon-assisted tunneling driven by 1/f noise. The noise power at microwave frequencies required to account for the observed errors is consistent with extrapolation of the low-frequency noise spectrum commonly recorded in single-electron transistors. Pump simulations, based on the ground-capacitance model, include cotunneling as well as single-junction photon-assisted tunneling. Quantitative agreement between theory and experiment is obtained for leakage and counting errors in pumps with four, five, six, and seven junctions in the limit of low temperatures and low counting rates. The effect of self-heating is explored. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Kautz, RL (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. NR 50 TC 27 Z9 27 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 DEC 15 PY 2000 VL 62 IS 23 BP 15888 EP 15902 DI 10.1103/PhysRevB.62.15888 PG 15 WC Physics, Condensed Matter SC Physics GA 385GK UT WOS:000165995100095 ER PT J AU Kilic, C Ciraci, S Gulseren, O Yildirim, T AF Kilic, C Ciraci, S Gulseren, O Yildirim, T TI Variable and reversible quantum structures on a single carbon nanotube SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-PROPERTIES; SUPERLATTICES; MICROTUBULES; TRANSPORT AB The band gap of a semiconducting single wall carbon nanotube decreases and eventually vanishes leading to metalization as a result of increasing radial deformation. This sets in a band offset between the undeformed and deformed regions of a single nanotube. Based on the superlattice calculations, we show that these features can be exploited to realize various quantum well structures on a single nanotube with variable and reversible electronic properties. These quantum structures and nanodevices incorporate mechanics and electronics. C1 Bilkent Univ, Dept Phys, Ankara, Turkey. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. RP Kilic, C (reprint author), Bilkent Univ, Dept Phys, Ankara, Turkey. RI yildirim, taner/A-1290-2009; Kilic, Cetin/E-1336-2011 OI Kilic, Cetin/0000-0003-2690-4940 NR 30 TC 45 Z9 45 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 DEC 15 PY 2000 VL 62 IS 24 BP 16345 EP 16348 PG 4 WC Physics, Condensed Matter SC Physics GA 390QL UT WOS:000166307800034 ER PT J AU Hong, SY Kalnay, E AF Hong, SY Kalnay, E TI Role of sea surface temperature and soil-moisture feedback in the 1998 Oklahoma-Texas drought SO NATURE LA English DT Article ID UNITED-STATES; TROPICAL PACIFIC; PRECIPITATION; CLIMATE; SUMMER; MODEL; VARIABILITY; ANOMALIES; WAVE; ENSO AB The drought that affected the US states of Oklahoma and Texas in the summer of 1998 was strong and persistent, with soil moisture reaching levels comparable to those of the 1930s 'dust bowl'(1,2). Although other effects of the record-strength 1997-98 El Nino were successfully predicted over much of the United States, the Oklahoma-Texas drought was not(3). Whereas the response of the tropical atmosphere to strong anomalies in sea surface temperature is quite predictable, the response of the extratropical atmosphere is more variable(4,5). Here we present results from mechanistic experiments to clarify the origin and maintenance of this extratropical climate extreme. In addition to global tmospheric models(6-11), we use a regional model(12,13) to isolate regional climate feedbacks. We conclude that during April and May 1998, sea surface temperature anomalies combined with a favourable atmospheric circulation to establish the drought. In June-August, the regional positive feedback associated with lower evaporation and precipitation contributed substantially to the maintenance of the drought. The drought ended in the autumn, when stronger large-scale weather systems were able to penetrate the region and overwhelm the soil-moisture feedback. Our results show the potential for numerical models including appropriate physical processes to make skilful predictions of regional climate. C1 Yonsei Univ, Dept Atmospher Sci, Seoul 134, South Korea. Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. RP Kalnay, E (reprint author), Yonsei Univ, Dept Atmospher Sci, Seoul 134, South Korea. RI Kalnay, Eugenia/F-4393-2010; Hong, Song-You/I-3824-2012; OI Kalnay, Eugenia/0000-0002-9984-9906 NR 22 TC 82 Z9 83 U1 0 U2 21 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 14 PY 2000 VL 408 IS 6814 BP 842 EP 844 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 382PK UT WOS:000165831300045 PM 11130719 ER PT J AU Zamlynny, V Burgess, I Szymanski, G Lipkowski, J Majewski, J Smith, G Satija, S Ivkov, R AF Zamlynny, V Burgess, I Szymanski, G Lipkowski, J Majewski, J Smith, G Satija, S Ivkov, R TI Electrochemical and neutron reflectivity studies of spontaneously formed amphiphilic surfactant bilayers at the gold-solution interface SO LANGMUIR LA English DT Article ID AU(111) ELECTRODE; ADSORPTION; MONOLAYERS; DIFFUSION; PYRIDINE AB We have employed electrochemical and neutron reflectivity measurements to study the transfer of 4-pentadecyl-pyridine (C15-4Py), an insoluble amphiphilic surfactant, from the gas-solution (G-S) interface to the metal-solution IM-S) interface of a Au(lll) electrode. Neutron reflectivity experiments have demonstrated that C15-4Py forms a bilayer at the Au(111) electrode surface. Electrochemical experiments demonstrated that this bilayer is formed spontaneously when the electrode surface is brought in contact with the film-covered G-S interface. The surfactant molecules can move from the G-S to the M-S interface across the triple-phase boundary formed where the metal, solution, and gas phases are in contact. Time-dependence experiments have shown that the spreading process is irreversible. Having formed a bilayer or monolayer at the M-S interface, the C15-4Py surfactant molecules do not move back to a film-free G-S interface. Three models were used to analyze the kinetics of spreading. Our results are best explained assuming that the spreading is a first-order surface reaction controlled by the activation barrier that the surfactant molecules have to overcome when crossing the triple-phase line. C1 Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr 12, Los Alamos, NM 87545 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Lipkowski, J (reprint author), Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. RI Lujan Center, LANL/G-4896-2012; Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 22 TC 18 Z9 18 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 12 PY 2000 VL 16 IS 25 BP 9861 EP 9870 DI 10.1021/la000022z PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 380VM UT WOS:000165724200029 ER PT J AU Arnold, CS Pappas, DP AF Arnold, CS Pappas, DP TI Gd(0001): A semi-infinite three-dimensional heisenberg ferromagnet with ordinary surface transition SO PHYSICAL REVIEW LETTERS LA English DT Article ID CURIE-TEMPERATURE; PHASE-TRANSITION; CRITICAL-BEHAVIOR; GD FILMS; MAGNETIC REORIENTATION; SPIN POLARIZATION; GADOLINIUM; ORDER; SUSCEPTIBILITY; RECONSTRUCTION AB By comparing the surface and, bulk magnetization of smooth, well-ordered Gd samples, we show that the surface has an ordinary transition, i.e., a common Curie temperature for surface and bulk;. A quantitative statistical analysis of the temperature dependent magnetization is presented. Critical exponents for both surface, beta (S) = 0.83 +/- 0.04, and bulk, beta (B) = 0.376 +/- 0.015, are consistent with the semi-infinite three-dimensional Heisenberg model with homogeneous exchange. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Arnold, CS (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. NR 52 TC 36 Z9 36 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 11 PY 2000 VL 85 IS 24 BP 5202 EP 5205 DI 10.1103/PhysRevLett.85.5202 PG 4 WC Physics, Multidisciplinary SC Physics GA 382CC UT WOS:000165800000047 ER PT J AU Rols, S Benes, Z Anglaret, E Sauvajol, JL Papanek, P Fischer, JE Coddens, G Schober, H Dianoux, AJ AF Rols, S Benes, Z Anglaret, E Sauvajol, JL Papanek, P Fischer, JE Coddens, G Schober, H Dianoux, AJ TI Phonon density of states of single-wall carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID INELASTIC-NEUTRON-SCATTERING; DIFFRACTION; ROPES; MODES AB The Vibrational density of states of single-walt carbon nanotubes (SWNT) was obtained from inelastic neutron scattering data from 0 to 225 meV. The spectrum is similar to that of graphite above 40 meV, white intratube features are clearly observed at 22 and 36 meV. An unusual energy dependence below 10 meV is assigned to contributions from intertube modes in the 2D triangular lattice of SWNT bundles, and from intertube coupling to intratube excitations. Good agreement between experiment and a calculated density of states for the SWNT lattice is found over the entire energy range. C1 Univ Montpellier 2, Dynam Phases Condensees Grp, UMR CNRS 5581, F-34095 Montpellier 5, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Univ Penn, Dept Met & Mat Engn, Philadelphia, PA 19104 USA. Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Ctr Etud Saclay, Leon Brillouin Lab, CEA CNRS, F-91191 Gif Sur Yvette, France. RP Rols, S (reprint author), Univ Montpellier 2, Dynam Phases Condensees Grp, UMR CNRS 5581, F-34095 Montpellier 5, France. RI ROLS, Stephane/A-1609-2013 OI ROLS, Stephane/0000-0002-9892-816X NR 24 TC 53 Z9 54 U1 2 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 11 PY 2000 VL 85 IS 24 BP 5222 EP 5225 DI 10.1103/PhysRevLett.85.5222 PG 4 WC Physics, Multidisciplinary SC Physics GA 382CC UT WOS:000165800000052 ER PT J AU Baron, E Branch, D Hauschildt, PH Filippenko, AV Kirshner, RP Challis, PM Jha, S Chevalier, R Fransson, C Lundqvist, P Garnavich, P Leibundgut, B McCray, R Michael, E Panagia, N Phillips, MM Pun, CSJ Schmidt, B Sonneborn, G Suntzeff, NB Wang, L Wheeler, JC AF Baron, E Branch, D Hauschildt, PH Filippenko, AV Kirshner, RP Challis, PM Jha, S Chevalier, R Fransson, C Lundqvist, P Garnavich, P Leibundgut, B McCray, R Michael, E Panagia, N Phillips, MM Pun, CSJ Schmidt, B Sonneborn, G Suntzeff, NB Wang, L Wheeler, JC TI Preliminary spectral analysis of the Type II supernova 1999em SO ASTROPHYSICAL JOURNAL LA English DT Article DE radiative transfer; stars : atmospheres; supernovae : individual (SN 1999em) ID DISTANCE; ATMOSPHERES; SN-1993J; 1987A AB We have calculated fast direct spectral model fits to two early-time spectra of the Type II plateau SN 1999em, using the SYNOW synthetic spectrum code. The first is an extremely early blue optical spectrum and the second a combined Hubble Space Telescope and optical spectrum obtained one week later. Spectroscopically this supernova appears to be a normal Type II, and these fits are in excellent agreement with the observed spectra. Our direct analysis suggests the presence of enhanced nitrogen. We have further studied these spectra with the full non-LTE general model atmosphere code PHOENIX. While we do not find confirmation for enhanced nitrogen (nor do we rule it out), we do require enhanced helium. An even more intriguing possible line identification is complicated Balmer and He I lines, which we show falls naturally out of the detailed calculations with a shallow density gradient. We also show that very early spectra such as those presented here combined with sophisticated spectral modeling allow an independent estimate of the total reddening to the supernova, since when the spectrum is very blue, dereddening leads to changes in the blue flux that cannot be reproduced by altering the "temperature" of the emitted radiation. These results are extremely encouraging since they imply that detailed modeling of early spectra can shed light on both the abundances and total extinction of SNe II, the latter improving their utility and reliability as distance indicators. C1 Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Stockholm Observ, SE-13336 Saltsjobaden, Sweden. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. European So Observ, D-85748 Garching, Germany. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Carnegie Inst Washington, Las Campanas Observ, La Serena, Chile. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Australian Natl Univ, Mt Stromlo Observ, Weston, ACT 2611, Australia. NOAA, Cerro Tololo Interamer Observ, La Serena, Chile. Univ Texas, Dept Astron, Austin, TX 78712 USA. RP Baron, E (reprint author), Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. RI Baron, Edward/A-9041-2009; Sonneborn, George/D-5255-2012; OI Baron, Edward/0000-0001-5393-1608; Schmidt, Brian/0000-0001-6589-1287 NR 22 TC 92 Z9 93 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2000 VL 545 IS 1 BP 444 EP 448 DI 10.1086/317795 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 385RW UT WOS:000166018300043 ER PT J AU Hart, SR Staudigel, H Koppers, AAP Blusztajn, J Baker, ET Workman, R Jackson, M Hauri, E Kurz, M Sims, K Fornari, D Saal, A Lyons, S AF Hart, S. R. Staudigel, H. Koppers, A. A. P. Blusztajn, J. Baker, E. T. Workman, R. Jackson, M. Hauri, E. Kurz, M. Sims, K. Fornari, D. Saal, A. Lyons, S. TI Vailu'u undersea volcano: The New Samoa SO GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS LA English DT Article DE Samoa; volcano; vailulu'u; hydrothermal; nephelometry; isotopes AB Vailulu'u Seamount is identified as an active volcano marking the current location of the Samoan hotspot. This seamount is located 45 km east of Ta'u Island, Samoa, at 169 degrees 03.5'W, 14 degrees 12.9'S. Vailulu'u defines the easternmost edge of the Samoan Swell, rising from the 5000-m ocean floor to a summit depth of 590 m and marked by a 400-m-deep and 2-km-wide summit crater. Its broad western rift and stellate morphology brand it as a juvenile progeny of Ta'u. Seven dredges, ranging from the summit to the SE Rift zone at 4200 m, recovered only alkali basalts and picrites. Isotopically, the volcane is strongly EM2 in character and clearly of Samoan pedigree (Sr-87/Sr-86: 0.7052-0.7067; Nd-143/Nd-144: 0.51267-0.51277; Pb-206/Pb-204: 19.19-19.40). The Po-210-Pb-210 data on two summit basalts indicate ages than 50 years; all of the rocks are extremely fresh and veneered with glass. An earthquake swarm in early 1995 may attest to a recent eruption cycle. A detailed nephelometry survey of the water column shows clear evidence for hydrothermal plume activity in the summit crater. The water inside the crater is very turbid (nephelometric turbidity unit (NTU) values up to 1.4), and a halo of "smog" several hundred meters thick encircles and extends away from the summit for at least 7 km. The turbid waters are highly enriched in manganese (up to 7.3 nmol/kg), providing further evidence of hydrothermal activity. Vailulu'u is similar to Loihi (Hawaii) in being an active volcanic construct at the eastern end of a hotspot chain; it differs importantly from the Hawaiian model in its total lack of tholeiitic basalt compositions. C1 [Hart, S. R.; Blusztajn, J.; Workman, R.; Kurz, M.; Sims, K.; Fornari, D.] Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. [Staudigel, H.; Koppers, A. A. P.; Lyons, S.] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. [Baker, E. T.] NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. [Jackson, M.] Yale Univ, Dept Geol & Geophys, New Haven, CT 06511 USA. [Hauri, E.] Carnegie Inst Sci, Dept Terr Magnetism, Washington, DC 20015 USA. [Saal, A.] Lamont Doherty Geol Observ, Palisades, NY 10964 USA. RP Hart, SR (reprint author), Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. EM shart@whoi.edu; hstaudig@ucsd.edu; akoppers@ucsd.edu; jblusztajn@whoi.edu; baker@pmel.noaa.gov; rworkman@whoi.edu; montanajacks@hotmail.com; hauri@dtm.ciw.edu; mkurz@whoi.edu; ksims@whoi.edu; dfornari@whoi.edu; asaal@ldeo.columbia.edu; slyons@ucsd.edu FU NSF; VENTS of NOAA (PMEL) [2243]; U.S. Coast Guard FX This work would not have been possible without the help of many individuals at sea, including Kendra Arbesman, Ron Comer, Jennifer Dodds, Scott Herman, Jasper Konter, Theresea-Mae Lassak, Gene Pillard, Ryan Taylor, and the crew of the R/V Melville and the Coast Guard's Polar Star. Kristin M. Sanborn helped us unlock the SeaBird CTD software. Bob Engdahl kindly supplied the 1995 earthquake locations. We acknowledge funding from the NSF Ocean Science program, the VENTS program of NOAA (PMEL contribution 2243), and the U.S. Coast Guard for their generous support of our endeavors on Vailulu'u. NR 35 TC 17 Z9 17 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1525-2027 J9 GEOCHEM GEOPHY GEOSY JI Geochem. Geophys. Geosyst. PD DEC 8 PY 2000 VL 1 DI 10.1029/2000GC000108 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA V22KI UT WOS:000208273700002 ER PT J AU Wang, H Composto, RJ AF Wang, H Composto, RJ TI Thin film polymer blends undergoing phase separation and wetting: Identification of early, intermediate, and late stages SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIRECTED SPINODAL DECOMPOSITION; BINARY-FLUID MIXTURES; LIGHT-SCATTERING; ISOBUTYRIC-ACID; LIQUID-MIXTURES; WATER MIXTURES; DOMAIN GROWTH; SILICA-GEL; DYNAMICS; KINETICS AB Using forward recoil spectrometry and atomic force microscopy, the phase evolution of a critical blend thin film of deuterated poly(methyl methacrylate) (dPMMA) and poly(styrene-ran-acrylonitrile) (SAN) is found to develop by three distinct stages. During the early stage, dPMMA-rich wetting layers rapidly grow at the air/polymer and polymer/substrate interfaces. A hydrodynamic flow mechanism is proposed based on the scaling of the layer thickness with time, t(-1), and the direct observation of an interconnected, bicontinuous morphology across the depletion zone. The lateral wave number of this morphology grows rapidly as t(-1) but slows down to t(-1/3) when the phase size approaches the film thickness. During the intermediate stage, the wetting layer thins and, concurrently, dPMMA-rich domains spanning the SAN-rich middle grow as t(-0.41) in good agreement with an interfacially driven growth model. During the late stage, these capillary fluctuations eventually cause spontaneous rupturing of the middle layer resulting in an interconnected 2D network which eventually coarsens into isolated SAN-rich droplets encapsulated by a thick dPMMA-rich wetting layer. The surface roughness increases rapidly initially, reaches a constant value, and then increases at a much faster rate than that predicted by a trilayer model based on capillary fluctuations. (C) 2000 American Institute of Physics. [S0021-9606(00)51046-0]. C1 Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. RP NIST, Div Polymer, Gaithersburg, MD 20899 USA. NR 94 TC 92 Z9 94 U1 4 U2 37 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 DEC 8 PY 2000 VL 113 IS 22 BP 10386 EP 10397 AR PII [S0021-9606(00)51046-0] DI 10.1063/1.1322638 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 378LB UT WOS:000165584900061 ER PT J AU Grodkowski, J Dhanasekaran, T Neta, P Hambright, P Brunschwig, BS Shinozaki, K Fujita, E AF Grodkowski, J Dhanasekaran, T Neta, P Hambright, P Brunschwig, BS Shinozaki, K Fujita, E TI Reduction of cobalt and iron phthalocyanines and the role of the reduced species in catalyzed photoreduction of CO2 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-METAL COMPLEXES; CARBON-DIOXIDE ACTIVATION; PHOTOCHEMICAL REDUCTION; ELECTROCATALYTIC REDUCTION; ELECTROCHEMICAL REDUCTION; ONE-ELECTRON; HOMOGENEOUS CATALYSIS; RADIOLYTIC REDUCTION; AQUEOUS-SOLUTIONS; TETRASODIUM SALT AB The role of cobalt and iron phthalocyanines in catalytic CO2 reduction has been studied. Chemical, photochemical, and radiolytic reductions of the metal phthalocyanines (Pc) have been carried out in organic solvents, and reduction of their tetrasulfonated derivatives (TSPc) in aqueous solutions. (CoPc)-Pc-II and (FePc)-Pc-II are readily reduced to [(CoPc)-Pc-I](-) and [F-I'Pc](-), which do not react with CO2. Reduction of [(CoPc)-Pc-I](-) yields a product which is characterized as the radical anion, [(CoPc.-)-Pc-I](2-), on the basis of its absorption spectra in the visible and IR regions. This species is stable under dry anaerobic conditions and reacts rapidly with CO2. Catalytic formation of CO and formate is confirmed by photochemical experiments in DMF and acetonitrile solutions containing triethylamine (TEA) as a reductive quencher. The photochemical yields are greatly enhanced by the addition of p-terphenyl (TP). The radical anion, TP.-, formed from the reductive quenching of the singlet excited state with TEA, reduces the phthalocyanines very rapidly. The rate constants for reduction of (CoPc)-Pc-II, [(CoPc)-Pc-I](-), and [(FePc)-Pc-I](-) by TP.-, determined by pulse radiolysis in DMF solutions, are nearly diffusion-controlled. The mono-reduced species formed from [(CoPc)-Pc-I](-) is unstable under the pulse radiolysis conditions but is longer-lived under the flash photolysis conditions. The interaction of this species with CO2 is either too weak or too slow to detect in the current experiments, where a competing reaction with protons predominates. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Neta, P (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Brunschwig, Bruce/G-4249-2011; Fujita, Etsuko/D-8814-2013 NR 51 TC 76 Z9 76 U1 7 U2 55 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 DEC 7 PY 2000 VL 104 IS 48 BP 11332 EP 11339 DI 10.1021/jp002709y PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 380WB UT WOS:000165725500013 ER PT J AU Devlin, RH Swanson, P Clarke, WC Plisetskaya, E Dickhoff, W Moriyama, S Yesaki, TY Hew, CL AF Devlin, RH Swanson, P Clarke, WC Plisetskaya, E Dickhoff, W Moriyama, S Yesaki, TY Hew, CL TI Seawater adaptability and hormone levels in growth-enhanced transgenic coho salmon, Oncorhynchus kisutch SO AQUACULTURE LA English DT Article DE transgenic; growth; smolt; osmoregulation; growth hormone; salmon ID PARR-SMOLT TRANSFORMATION; FACTOR-I GENE; RAINBOW-TROUT; ATLANTIC SALMON; IGF-I; THYROID-HORMONES; OSMOREGULATORY ACTIONS; BRANCHIAL CARTILAGE; SULFATE UPTAKE; THYROXINE INJECTIONS AB Transgenic coho salmon containing a growth hormone (GH) gene construct have been examined for their hormone levels and ability to osmoregulate in sea water. Relative to their smaller nontransgenic siblings (age controls), GH-transgenic coho precociously develop external phenotypes and hypo-osmoregulatory ability typical of smolts. Specific growth rates of the transgenic coho were approximately 2.7-fold higher than older nontransgenic animals of similar size, and 1.7-fold higher than their nontransgenic siblings. GH levels were increased dramatically (19.3- to 32.1-fold) relative to size control salmon, but IGF-I levels were only modestly affected, being slightly enhanced in one experiment and slightly reduced in another. Insulin levels in transgenic animals did not differ from size controls, but were higher than nontransgenic siblings, and thyroxine levels in transgenic animals were intermediate between levels found in size and age controls. The homeostatic controls of, and interactions among, these hormones are discussed with respect to their effects on growth and osmoregulation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fisheries & Oceans Canada, W Vancouver Lab, W Vancouver, BC V7V 1N6, Canada. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Fisheries & Oceans Canada, Nanaimo, BC V9R 5K6, Canada. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Univ Toronto, Dept Biochem & Clin Biochem, Toronto, ON M5G 1L5, Canada. RP Devlin, RH (reprint author), Fisheries & Oceans Canada, W Vancouver Lab, 4160 Marine Dr, W Vancouver, BC V7V 1N6, Canada. RI Hew, Choy Leong/I-1501-2012 OI Hew, Choy Leong/0000-0002-9441-0064 NR 100 TC 46 Z9 48 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD DEC 5 PY 2000 VL 191 IS 4 BP 367 EP 385 DI 10.1016/S0044-8486(00)00484-1 PG 19 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 364HF UT WOS:000089886400008 ER PT J AU Thompson, RE Voit, EO Scott, GI AF Thompson, RE Voit, EO Scott, GI TI A probabilistic model for predicting distributions of PAH ratios between oysters and marine sediments SO ECOLOGICAL MODELLING LA English DT Article DE bioaccumulation; PAHs; Equilibrium Partitioning Model; Weibull distribution; loglogistic distribution; sediment pollution ID ORGANIC-CHEMICALS; NATURAL SEDIMENTS; QUALITY CRITERIA; SORPTION AB Modeling the uptake of organic chemicals by aquatic organisms is an important step in assessing human exposure to harmful environmental contaminants via seafood consumption. In many cases, investigators have applied the Equilibrium Partitioning (EqP) Model to determine the bioavailability of organic contaminants. This model assumes that a thermodynamic equilibrium exists between local environmental phases. It relies on point-estimated biota-to-sediment ratios (BSRs) to predict the concentration of organic residuals in the lipid tissues of organisms from the measured amounts of contaminants in the organic carbon component of the sediment. The paper presents a modeling analysis of polycyclic aromatic hydrocarbon (PAH) oyster and sediment contamination data collected at Murrells Inlet, SC, a high salinity estuary located in a heavily urbanized area just south of Myrtle Beach, SC. Three representative PAH analytes are considered: phenanthrene (PHE), pyrene (PYR) and chrysene (CRY). Statistical tests and scatter plots of lipid and organic carbon-normalized data clearly indicate that point-estimated BSRs of the EqP model are not appropriate for this system. As an alternative, the paper proposes a probabilistic model that describes the distributions of BSR values for each analyte. BSR upper limit confidence intervals given by these models are equal in magnitude to those derived from equilibrium partitioning. However, contrary to the predictions of the EqP model, BSR values appear to decrease with an increase in the molecular weight of the analyte. This suggests that heavier PAHs are 'falling out' of the water column into the sediment and become less available for uptake by oysters. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Med Univ S Carolina, Dept Biometry & Epidemiol, Charleston, SC 29425 USA. NOAA, NOS Charleston Ctr Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Thompson, RE (reprint author), Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Biostat, 615 N Wolfe St, Baltimore, MD 21205 USA. NR 31 TC 10 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD DEC 5 PY 2000 VL 135 IS 2-3 BP 231 EP 242 DI 10.1016/S0304-3800(00)00367-7 PG 12 WC Ecology SC Environmental Sciences & Ecology GA 389PR UT WOS:000166247400007 ER PT J AU Chapekar, MS AF Chapekar, MS TI Tissue engineering: Challenges and opportunities SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE tissue engineering; biomaterials; cells; biomolecules; Advanced Technology Program ID IN-VITRO; STEM-CELLS; MATRICES; REPLACEMENT; EQUIVALENT; CHANNEL; TENDON AB This article reviews the key developments in the tissue engineering field over the past several years. The issues related to the development of the components of tissue-engineered products including cells, biomaterials, and biomolecules, and their integration into safe and effective products are presented, Moreover, the article outlines the challenges to the commercialization of tissue-engineered products, and highlights the ongoing efforts by the American Society for Testing and Materials (ASTM) in developing standards for tissue-engineered medical products, Furthermore, funding opportunities at the Advanced Technology Program at NIST are presented, (C) 2000 John Wiley & Sons, Inc.* C1 US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Adv Technol Program,Chem & Life Sci Office, Gaithersburg, MD 20899 USA. RP Chapekar, MS (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Adv Technol Program,Chem & Life Sci Office, 100 Bur Dr,Mail Stop 4730, Gaithersburg, MD 20899 USA. NR 40 TC 147 Z9 155 U1 0 U2 16 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 DEC 5 PY 2000 VL 53 IS 6 BP 617 EP 620 DI 10.1002/1097-4636(2000)53:6<617::AID-JBM1>3.0.CO;2-C PG 4 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 375DN UT WOS:000165384400001 PM 11074418 ER PT J AU Sambasivan, S Fischer, DA DeKoven, BM Kuperman, A AF Sambasivan, S Fischer, DA DeKoven, BM Kuperman, A TI Direct observations of propylene and silver transformations on the surface and in the pores of silver Y zeolites SO ADVANCED MATERIALS LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; SHELL EXCITATION-SPECTRA; CLUSTERS; ACIDITY; ATOMS; OXIDATION; REDUCTION; AG(110); STATE; NMR C1 Dow Chem Co, Midland, MI 48674 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Dow Chem Co USA, Sci Analyt Lab, Midland, MI 48667 USA. RP Kuperman, A (reprint author), Chevron Res & Technol Co, 100 Chevron Way, Richmond, CA 94802 USA. NR 34 TC 5 Z9 5 U1 0 U2 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD DEC 1 PY 2000 VL 12 IS 23 BP 1809 EP 1813 DI 10.1002/1521-4095(200012)12:23<1809::AID-ADMA1809>3.0.CO;2-B PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 390JK UT WOS:000166291800016 ER PT J AU Beckman, BR Fairgrieve, W Cooper, KA Mahnken, CVW Dickhoff, WW AF Beckman, BR Fairgrieve, W Cooper, KA Mahnken, CVW Dickhoff, WW TI Endocrine correlates of growth in ocean dwelling coho salmon. SO AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 NW Fisheries Sci Ctr, Natl Marina, Seattle, WA 98112 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD DEC PY 2000 VL 40 IS 6 BP 940 EP 940 PG 1 WC Zoology SC Zoology GA 422RA UT WOS:000168132000052 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 AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. RI Halanych, Ken/A-9480-2009; Dahlgren, Thomas/B-1636-2010 OI Halanych, Ken/0000-0002-8658-9674; NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD DEC PY 2000 VL 40 IS 6 BP 989 EP 989 PG 1 WC Zoology SC Zoology GA 422RA UT WOS:000168132000175 ER PT J AU Moore, SE DeMaster, DP Dayton, PK AF Moore, SE DeMaster, DP Dayton, PK TI Cetacean habitat selection in the Alaskan Arctic during summer and autumn SO ARCTIC LA English DT Article; Proceedings Paper CT Conference on Arctic Seas - Currents of Change CY OCT 21-24, 1998 CL MYSTIC, CT DE Alaska; Arctic; Beaufort Sea; bowhead whale; Chukchi Sea; gray whale; habitat selection; white whale ID COD BOREOGADUS-SAIDA; BERING STRAIT; INTERANNUAL VARIABILITY; BOWHEAD WHALES; BEAUFORT SEA; POINT BARROW; CHUKCHI SEAS; ICE EDGE; OCEAN; DISTRIBUTIONS AB Ten years (1982-91) of sighting data from aerial surveys offshore of northern Alaska were analyzed to investigate seasonal variability in cetacean habitat selection. Distinct habitats were described for bowhead whales (Balaena mysticetus), white whales (Delphinapterus leucas), and gray whales (Eschrichtius robustus) on the basis of habitat selection ratios calculated for bathymetric and ice cover regimes. In summer, bowheads selected continental slope waters and moderate ice conditions; white whales selected slope and basin waters and moderate to heavy ice conditions; and gray whales selected coastal/shoal waters and open water. In autumn, bowheads selected inner shelf waters and light ice conditions; white whales selected outer shelf and slope waters and moderate to heavy ice; and gray whales selected coastal and shoal/trough habitats in light ice and open water. Habitat differences among species were significant in both seasons (ANOVA F > 28, p < 0.00001). Interseasonal depth and ice cover habitats were significantly different for bowhead whales (p < 0.00002), but not for gray whales p > 0.35). White whale depth habitat was significantly different between seasons (p < 0.00002), but ice cover habitat was not (p < 0.08). C1 SAIC, Maritime Serv Div, San Diego, CA 92110 USA. NOAA, Natl Marine Fisheries Serv, AFSC, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Univ Calif San Diego, Scripps Inst Oceanog, Marine Life Res Grp, La Jolla, CA 92093 USA. RP Moore, SE (reprint author), NOAA, Natl Marine Fisheries Serv, AFSC, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM Sue.Moore@noaa.gov NR 74 TC 64 Z9 66 U1 2 U2 15 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 EI 1923-1245 J9 ARCTIC JI Arctic PD DEC PY 2000 VL 53 IS 4 BP 432 EP 447 PG 16 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 388UP UT WOS:000166201700009 ER PT J AU Moore, SE AF Moore, SE TI Variability of Cetacean distribution and habitat selection in the Alaskan Arctic, autumn 1982-91 SO ARCTIC LA English DT Article; Proceedings Paper CT Conference on Arctic Seas - Currents of Change CY OCT 21-24, 1998 CL MYSTIC, CONNECTICUT DE Alaska; Arctic; Beaufort Sea; bowhead whale; Chukchi Sea; gray whale; habitat selection; white whale ID COD BOREOGADUS-SAIDA; INTERANNUAL VARIABILITY; BERING STRAIT; CHUKCHI SEA; CLIMATIC-CHANGE; AERIAL SURVEYS; BEAUFORT SEA; ICE EXTENT; WATERS; OCEAN AB Ten years (1982-91) of autumn sighting data from aerial surveys offshore northern Alaska were analyzed to investigate variability in cetacean distribution and habitat selection. Habitat selection indices were calculated for bowhead, white, and gray whales in heavy, moderate, and light ice conditions; and for high, moderate, and low transport (inflow) conditions at Bering Strait. Bowhead whales selected shallow inner-shelf waters during moderate and light ice, and deeper slope habitat in heavy ice conditions (chi (2), p < 0.05 - 0.001). White whales selected slope habitat ((2), p < 0.001), and gray whales selected coastal/shoal and shelf/trough habitat ((2), p < 0.025 - 0.001), in all ice conditions. In the Alaskan Beaufort Sea, bowheads selected shelf waters and white whales chose slope waters, without regard to transport conditions ((2), P < 0.01 - 0.001). In the northern Chukchi Sea, gray whales selected coastal/shoal habitat in high transport conditions ((2), p < 0.005), and shelf/trough habitat ((2), p < 0.001) during moderate and low transport conditions. Variability in distribution and habitat selection among these species is likely linked to prey availability at dissimilar trophic levels, although this hypothesis has yet to be rigorously tested. C1 Scripps Inst Oceanog, SAIC, Maritime Serv Div, San Diego, CA 92110 USA. RP Moore, SE (reprint author), NOAA, Natl Marine Fisheries Serv, AFSC, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 69 TC 22 Z9 24 U1 0 U2 6 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD DEC PY 2000 VL 53 IS 4 BP 448 EP 460 PG 13 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 388UP UT WOS:000166201700010 ER PT J AU Grady, CA Devine, D Woodgate, B Kimble, R Bruhweiler, FC Boggess, A Linsky, JL Plait, P Clampin, M Kalas, P AF Grady, CA Devine, D Woodgate, B Kimble, R Bruhweiler, FC Boggess, A Linsky, JL Plait, P Clampin, M Kalas, P TI Stis coronagraphic imaging of the Herbig Ae star: HD 163296 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems; stars : individual (HD 163296); stars : pre-main-sequence ID MODEL SCATTERING ENVELOPES; YOUNG STELLAR OBJECTS; X-RAY-EMISSION; AE/BE STARS; CIRCUMSTELLAR DISKS; PLANET FORMATION; HIGH-RESOLUTION; BETA-PICTORIS; HD-163296; SYSTEMS AB Coronagraphic imaging with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveals a similar to 450 AU radius circumstellar disk around the Herbig Ae star HD 163296. A broadband (0.2-1.0 mum) reflected light image shows the disk oriented at a position angle of 140 degrees +/- 5 degrees and inclined to our line of sight by similar to 60 degrees +/- 5 degrees. The disk includes an annulus of reduced scattering at 325 AU and exhibits a flat trend of surface brightness in to 180-122 AU (1."5-1 "), consistent with a cleared central zone. For r greater than or equal to 370 AU the disk surface brightness drops as r to the approximately -3.5 power. The disk cannot: be traced beyond 450 AU in our data. The disk is accompanied by a chain of nebulosities at P.A. = 42 degrees .5 +/- 3 degrees .5, compatible with detection of a Herbig-Haro flow. The HD 163296 disk most closely resembles the disk of HD 141569. As in the HD 141569 system, the dynamical effects of a planet may be necessary to explain the structure in the outer disk. C1 NOAO, STIS, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Adv Comp Concepts Inc, Potomac, MD 20854 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Grady, CA (reprint author), NOAO, STIS, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012 NR 48 TC 95 Z9 95 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2000 VL 544 IS 2 BP 895 EP 902 DI 10.1086/317222 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 384FA UT WOS:000165931100026 ER PT J AU Osten, RA Brown, A Ayres, TR Linsky, JL Drake, SA Gagne, M Stern, RA AF Osten, RA Brown, A Ayres, TR Linsky, JL Drake, SA Gagne, M Stern, RA TI Radio, X-ray, and extreme-ultraviolet coronal variability of the short-period RS canum venaticorum binary sigma(2) coronae borealis SO ASTROPHYSICAL JOURNAL LA English DT Article DE radio continuum : stars; stars : activity; stars : coronae; stars : late-type; X-rays : stars ID CHROMOSPHERICALLY ACTIVE BINARIES; H-ALPHA EMISSION; CA-II-H; SOLAR-FLARES; CVN BINARIES; AU-MICROSCOPII; AR-LACERTAE; CONTINUUM EMISSION; QUIESCENT EMISSION; STELLAR CORONAE AB We present the results of a coordinated observing campaign on the short-period (1.14 days) RS CVn binary sigma (2) Coronae Borealis with the VLA, ASCA, and RXTE. We also discuss earlier observations of the same system obtained by the Extreme Ultraviolet ExpEorer (EUVE). Dramatic coronal variability is present in all of these observations across the electromagnetic spectrum. sigma (2) CrB undergoes frequent large flares that occur close together in time. Radio flares are unambiguously correlated with X-ray flares; the X-ray flares peak as much as 1.4 hr before the corresponding radio maxima. Response to flares is more rapid in higher energy X-ray bandpasses, signaling an increase in temperature during the course of the flare. Flares are seen more frequently in the harder RXTE bandpass than in simultaneously taken ASCA observations. There is greater contrast between flaring and nonflaring conditions in the RXTE light curve. Complex Raring is seen in the radio at 3 and 6 cm, consistent with optically thin nonthermal gyrosynchrotron emission for most of the duration of the observation. Bursts of left-circularly polarized emission at 20 cm lasting less than or equal to 5 minutes appear to be due to a coherent emission process. EUVE spectra reveal coronal material at n(e) less than or equal to 10(12) cm(-3), With no discernible density differences between flaring and quiescent time intervals. Quiescent ASCA spectra show lower than solar photospheric abundances with iron depleted by a factor of 4 from the solar photospheric value. The abundances increase during a large flare observed with ASCA, with iron enhanced to the solar photospheric value during the rise phase of the hare. Two-temperature fits to extracted spectra show a low-temperature quiescent value of 8 MK and a high-temperature component that varies from 22 MK during quiescence to 50 MK at the peak of the flare. Emission measure distributions measured from the ASCA observations are consistent with the temperatures derived from the discrete two-temperature fits and indicate the presence of very hot (> 100 MK) plasma during the rise phase of the ASCA Bare. Many of the flares observed with EUVE, ASCA, and RXTE show a double exponential decay phase, further highlighting the importance of this phenomenon in diagnosing flaring conditions. We also find that the observed second decay timescale cannot be explained by some of the currently used flare parameterizations. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, HEASARC, Greenbelt, MD 20771 USA. W Chester Univ, W Chester, PA 19383 USA. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA 94304 USA. RP Osten, RA (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. RI Gagne, Marc/C-1130-2013 NR 79 TC 37 Z9 37 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2000 VL 544 IS 2 BP 953 EP 976 DI 10.1086/317249 PN 1 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 384FA UT WOS:000165931100033 ER PT J AU Rodionov, S Assel, R AF Rodionov, S Assel, R TI Atmospheric teleconnection patterns and severity of winters in the laurentian Great Lakes basin SO ATMOSPHERE-OCEAN LA English DT Article ID NORTHERN HEMISPHERE WINTER; SEA-SURFACE TEMPERATURE; GEOPOTENTIAL HEIGHT FIELD; UNITED-STATES CLIMATE; CIRCULATION PATTERNS; SOUTHERN OSCILLATION; ICE-COVER; EL-NINO; SST ANOMALIES; LA NINA AB We analyzed the relationship between an index of Great Lakes winter severity (winters 1950-1998) and atmosphere circulation characteristics. Classification and Regression Tree analysis methods allowed us to develop a simpler characterization of warm, normal and cold winters in terms of teleconnection and their combinations. Results are presented in the form of decision trees. The single most important classifies for warm winters was the Polar/Eurasian index (POL). A majority of warm winters (12 out of 15) occurred when this index was substantially positive (POL > 0.23). There were no cold winters (12 out of 15) occurred when this index was substantially positive (POL > 0.23). There were no cold winters when this condition was in place. Warm winters are associated with a positive phase of the Western Pacific pattern and El Nino events in the equatorial Pacific. The association between cold winters and La Nina events was much weaker. Thus, the effect of the El Nino/Southern Oscillation (ENSO) on severity of winters in the great Lakes basin is not symmetric. The structure of the relationship between the index of winter severity and telecommunication indices is more complex for cold winters than for warm winters. It takes two or more indices to successfully classify cold winters. In general, warm winters are characterized by a predominantly zonal type of atmospheric circulation over the Northern Hemisphere (type W1). Within this type of circulation it is possible to distinguish two sub-types, W2 and W3. Sub-type W2 is characterized by a high-pressure cell over North America, which is accompanied by enhanced cyclonic activity over the eastern North Pacific. Due to a broad southerly "anomalous" flow, surface air temperatures (SATs) are above normal almost everywhere over the continent. During the W3 sub-type, the polar jet stream over North America instead of forming a typical ridge-trough pattern, is almost entirely zonal, thus effectively blocking an advection of cold Arctic air to the south. Cold winters tend to occur when the atmospheric circulation is more meridional (type C1). As with warm winters, there are two sub-types of circulation, C2 and C3. In the case of C2, the jet stream loops southward over the western part of North America, but its northern excursion over the eastern part is suppressed. In this situation, the probability of a cold winter is higher for Lake Superior than for the lower Great Lakes. Sub-type C3 is characterized by an amplification of the climatological ridge over the Rockies and the trough over the East Coast. The strongest negative SAT anomalies are located south of the Great Lakes basin, so that the probability of a cold winter is higher for the lower Great Lakes then for Lake Superior. C1 Natl Ocean & Atmospher Adm, US Dept Commerce, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Assel, R (reprint author), Natl Ocean & Atmospher Adm, US Dept Commerce, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. OI Rodionov, Sergei/0000-0002-5318-9746 NR 50 TC 26 Z9 26 U1 0 U2 7 PU CANADIAN METEOROLOGICAL OCEANOGRAPHIC SOC PI OTTAWA PA 150 LOUIS PASTEUR PVT., STE 112, MCDONALD BUILDING, OTTAWA, ONTARIO K1N 6N5, CANADA SN 0705-5900 J9 ATMOS OCEAN JI Atmos.-Ocean PD DEC PY 2000 VL 38 IS 4 BP 601 EP 635 PG 35 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 392HY UT WOS:000166406700004 ER PT J AU Green, EP Bruckner, AW AF Green, EP Bruckner, AW TI The significance of coral disease epizootiology for coral reef conservation SO BIOLOGICAL CONSERVATION LA English DT Review DE coral; disease; mortality; incidence; epizootiology ID BLACK-BAND DISEASE; ACROPORA-PALMATA; FLORIDA-KEYS; CARIBBEAN COAST; MASS MORTALITY; SEA FANS; GROWTH; POPULATIONS; GORGONIIDAE; COMMUNITY AB There are many aspects of coral disease that are poorly understood. The relationship, if any, between human activities and the incidence of coral disease is particularly important since it is frequently assumed that the number and prevalence of diseases are increasing, and are indicative of a general decline in the marine environment. Certainly a good understanding of these issues would assist in the conservation of coral reefs by identifying targets for mitigating management programmes. In situ observations of coral disease and associated mortality were therefore compiled from more than 150 sources, and reviewed. Although there have been cases where disease has caused major changes in the composition and structure of reefs, most notably in the Caribbean, these are exceptions when compared to the number of locations at which disease has been observed. With the exception of white-band disease, most frequently observed diseases do not appear to be specific in their host requirements, affecting species in many different genera. The overwhelming majority of disease in the Caribbean (97% of locations) has been recorded from coral reefs where human activities are expected to have medium to high impacts. Regional scale patterns in the incidence of coral disease may therefore be suitable bio-indicators of disturbance to coral reefs. This potential relationship should be investigated further with a view to using patterns of disease to monitor specific sources of stress on reefs. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 WCMC, UNEP, Cambridge CB3 0DL, England. NOAA, Natl Marine Fisheries Serv, Silver Spring, MD 20910 USA. RP Green, EP (reprint author), WCMC, UNEP, 219 Huntingdon Rd, Cambridge CB3 0DL, England. NR 123 TC 165 Z9 173 U1 4 U2 53 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0006-3207 J9 BIOL CONSERV JI Biol. Conserv. PD DEC PY 2000 VL 96 IS 3 BP 347 EP 361 DI 10.1016/S0006-3207(00)00073-2 PG 15 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 368VR UT WOS:000090138600009 ER PT J AU Cole, KD Akerman, B AF Cole, KD Akerman, B TI Enhanced capacity for electrophoretic capture of plasmid DNA by agarase treatment of agarose gels SO BIOMACROMOLECULES LA English DT Article ID CIRCULAR DNA; MOLECULAR-WEIGHT; BEHAVIOR; POLYACRYLAMIDE; ORIENTATION; MIGRATION; DYNAMICS AB Agarase was used investigate the effect of increasing the number of polymer ends on the electrophoretic trapping of circular DNA in agarose gels. The electric field strength required to trap circular DNA was found to be the same in control and treated gels, indicating the treatment did not result in longer traps. Loading experiments indicated that treated gels had a significantly higher capacity for the open circular DNA. Electrophoretic mobility measurements using pulsed fields indicated a higher density of active traps for treated gels compared to controls. Linear dichroism experiments showed that impalement occurred by a fast and a slow process that had characteristic time constants in the one and tens of seconds ranges, respectively. The open circular DNA was more efficiently impaled in the treated gel compared to the control. The considerably higher efficiency of trapping indicated that agarase treatment increased the concentration of traps substantially. C1 Natl Inst Stand & Technol, Div Biotechnol, Bioproc Engn Grp, Gaithersburg, MD 20899 USA. Chalmers Univ Technol, Dept Phys Chem, S-41296 Gothenburg, Sweden. RP Cole, KD (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Bioproc Engn Grp, Gaithersburg, MD 20899 USA. NR 22 TC 12 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1525-7797 J9 BIOMACROMOLECULES JI Biomacromolecules PD WIN PY 2000 VL 1 IS 4 BP 771 EP 781 DI 10.1021/bm005594c PG 11 WC Biochemistry & Molecular Biology; Chemistry, Organic; Polymer Science SC Biochemistry & Molecular Biology; Chemistry; Polymer Science GA 433JD UT WOS:000168755500038 PM 11710211 ER PT J AU Tarek, M Tobias, DJ AF Tarek, M Tobias, DJ TI The dynamics of protein hydration water: A quantitative comparison of molecular dynamics simulations and neutron-scattering experiments SO BIOPHYSICAL JOURNAL LA English DT Article ID AQUEOUS-SOLUTION; RIBONUCLEASE-A; GLOBULAR PROTEIN; SLOW DYNAMICS; RELAXATION DISPERSION; ANOMALOUS DIFFUSION; SUPERCOOLED WATER; GLASS-TRANSITION; THERMAL MOTIONS; BACTERIORHODOPSIN AB We present results from an extensive molecular dynamics simulation study of water hydrating the protein Ribonuclease A, at a series of temperatures in cluster, crystal, and powder environments. The dynamics of protein hydration water appear to be very similar in crystal and powder environments at moderate to high hydration levels. Thus, we contend that experiments performed on powder samples are appropriate for discussing hydration water dynamics in native protein environments. Our analysis reveals that simulations performed on cluster models consisting of proteins surrounded by a finite water shell with free boundaries are not appropriate for the study of the solvent dynamics. Detailed comparison to available x-ray diffraction and inelastic neutron-scattering data shows that current generation force fields are capable of accurately reproducing the structural and dynamical observables. On the time scale of tens of picoseconds, at room temperature and high hydration, significant water translational diffusion and rotational motion occur. At low hydration, the water molecules are translationally confined but display appreciable rotational motion. Below the protein dynamical transition temperature, both translational and rotational motions of the water molecules are essentially arrested. Taken together, these results suggest that water translational motion is necessary for the structural relaxation that permits anharmonic and diffusive motions in proteins. Furthermore, it appears that the exchange of protein-water hydrogen bonds by water rotational/librational motion is not sufficient to permit protein structural relaxation. Rather, the complete exchange of protein-bound water molecules by translational displacement seems to be required. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Univ Calif Irvine, Inst Surface & Interface Sci, Irvine, CA 92697 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. RP Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. EM dtobias@uci.edu RI Tobias, Douglas/B-6799-2015 NR 67 TC 219 Z9 221 U1 0 U2 50 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 0006-3495 EI 1542-0086 J9 BIOPHYS J JI Biophys. J. PD DEC PY 2000 VL 79 IS 6 BP 3244 EP 3257 PG 14 WC Biophysics SC Biophysics GA 381EH UT WOS:000165749000041 PM 11106628 ER PT J AU Majkrzak, CF Berk, NF Krueger, S Dura, JA Tarek, M Tobias, D Silin, V Meuse, CW Woodward, J Plant, AL AF Majkrzak, CF Berk, NF Krueger, S Dura, JA Tarek, M Tobias, D Silin, V Meuse, CW Woodward, J Plant, AL TI First-principles determination of hybrid bilayer membrane structure by phase-sensitive neutron reflectometry SO BIOPHYSICAL JOURNAL LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SPECULAR REFLECTION; INVERSE PROBLEM; X-RAY; SURFACE; INFORMATION; RECONSTRUCTION; PROFILES; WATER; GOLD AB The application of a new, phase-sensitive neutron reflectometry method to reveal the compositional depth profiles of biomimetic membranes is reported. Determination of the complex reflection amplitude allows the related scattering length density (SLD) profile to be obtained by a first-principles inversion without the need for fitting or adjustable parameters. The SLD profile so obtained is unique for most membranes and can therefore be directly compared with the SLD profile corresponding to the chemical compositional profile of the film, as predicted, for example, by a molecular dynamics simulation. Knowledge of the real part of the reflection amplitude, in addition to enabling the inversion, makes it possible to assign a spatial resolution to the profile for a given range of wavevector transfer over which the reflectivity data are collected. Furthermore, the imaginary part of the reflection amplitude can be used as a sensitive diagnostic tool for recognizing the existence of certain in-plane inhomogeneities in the sample. Measurements demonstrating the practical realization of this phase-sensitive technique were performed on a hybrid bilayer membrane (self-assembled monolayer of thiahexa (ethylene oxide) alkane on gold and a phospholipid layer) in intimate contact with an aqueous reservoir. Analysis of the experimental results shows that accurate compositional depth profiles can now be obtained with a spatial resolution in the subnanometer range, primarily limited by the background originating from the reservoir and the roughness of the film's supporting substrate. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Chem, Philadelphia, PA 19103 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Krueger, S (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, 108 Bur Dr,Stop 8562, Gaithersburg, MD 20899 USA. RI Dura, Joseph/B-8452-2008 OI Dura, Joseph/0000-0001-6877-959X NR 37 TC 50 Z9 51 U1 0 U2 7 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD DEC PY 2000 VL 79 IS 6 BP 3330 EP 3340 PG 11 WC Biophysics SC Biophysics GA 381EH UT WOS:000165749000048 PM 11106635 ER PT J AU Cole, KD AF Cole, KD TI Laboratory database to manage electrophoresis and chromatography separations and the associated samples SO BIOTECHNIQUES LA English DT Article AB A database was developed to store, organize, and retrieve the data associated with electrophoresis and chromatography separations. It allows laboratories to store extensive data on separation techniques (analytical and preparative). The data for gel electrophoresis includes gel composition, staining methods, electric fields, analysis, and samples loaded. The database stores data on chromatography conditions, the samples used and the fractions collected. The data structure of this database was designed to maintain the link between samples (including fractions) from chromatography separations and their analysis by gel electrophoresis. The database will allow laboratories to organize and maintain a large amount of separation and sample data in a uniform data environment. If will facilitate the retrieval of the separation history of important samples and the separation conditions used. C1 NIST, Div Biotechnol, Bioproc Engn Grp, Gaithersburg, MD 20899 USA. RP Cole, KD (reprint author), NIST, Div Biotechnol, Bioproc Engn Grp, Stop 8312, Gaithersburg, MD 20899 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD DEC PY 2000 VL 29 IS 6 BP 1256 EP + PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 382QG UT WOS:000165833300017 PM 11126129 ER PT J AU Paw, KT Baldocchi, DD Meyers, TP Wilson, KB AF Paw, KT Baldocchi, DD Meyers, TP Wilson, KB TI Correction of eddy-covariance measurements incorporating both advective effects and density fluxes SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE advection; carbon dioxide; density correction; eddy covariance ID SURFACE-AIR EXCHANGE; MICROMETEOROLOGICAL OBSERVATIONS; TALL VEGETATION; ENERGY; FOREST; HEAT AB Equations are presented to correct eddy-covariance measurements for both fluctuations in density and non-zero mean advection, induced by convergence or divergence of flow, and spatial source/sink inhomogeneity, under steady-state and transient conditions. This correction collapses to the Webb-Pearman-Leuning expression if the mean vertical velocity is zero, and formally adds the Webb-Pearman-Leuning expression to the corrections suggested by Lee for conditions of non-zero vertical velocity and source/sink and mean scalar horizontal homogeneity. The equation requires measurement of the mean vertical gradients of the scalar concentration of interest (air temperature, humidity, CO2) as well as an accurate estimation of the mean vertical velocity, in addition to the vertical eddy covariance of the scalar. Simple methods for the approximation of sensor tilt and complex terrain flow angle are presented, to allow estimation of non-zero mean vertical velocities. The equations are applied to data from a maize crop and a forest to give examples of when the correction is significant. In addition, a term for the thermodynamic expansion energy associated with water vapour flux is derived, which implies that the sonic temperature derived sensible heat flux will accurately include this contribution. C1 Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. NOAA, Atmospher Turbulence & Diffus Div, Environm Res Lab, Oak Ridge, TN 37830 USA. RP Paw, KT (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Baldocchi, Dennis/A-1625-2009; Meyers, Tilden/C-6633-2016 OI Baldocchi, Dennis/0000-0003-3496-4919; NR 24 TC 64 Z9 66 U1 6 U2 22 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD DEC PY 2000 VL 97 IS 3 BP 487 EP 511 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357JV UT WOS:000089496000006 ER PT J AU Schlatter, T AF Schlatter, T TI The coming metamorphosis of BAMS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 NOAA, Forecast Syst Lab, Boulder, CO 80303 USA. RP Schlatter, T (reprint author), NOAA, Forecast Syst Lab, 325 Broadway, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 2000 VL 81 IS 12 BP 3010 EP 3013 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 379ZG UT WOS:000165672600011 ER PT J AU McConnaughey, RA Smith, KR AF McConnaughey, RA Smith, KR TI Associations between flatfish abundance and surficial sediments in the eastern Bering Sea SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COD GADUS-MORHUA; GEORGES-BANK; ENGLISH SOLE; HABITAT; GROWTH; HIPPOGLOSSOIDES; SELECTION; MATURITY; ECOLOGY; BENTHOS AB Spatially explicit relationships between pleuronectid flatfish abundance and surficial sediments in the eastern Bering Sea were investigated using published sediment descriptions and trawl survey data (1982-1994). Flatfish food habits were also examined because sediment properties are known to affect the distribution and abundance of benthic prey. For six species, we compared sediment textures in areas of highest and lowest abundance (kilograms per hectare). Sand predominated in areas of high yellowfin sole (Pleuronectes asper) (YFS) (p < < 0.001) and rock sole (Lepidopsetta spp.) (RS) (p < < 0.001) abundance, while mixed sand and mud was most common in areas of lowest abundance. In contrast, mixed sand and mud predominated in areas preferred by flathead sole (Hippoglossoides elassodon) (FHS) (p < < 0.001), Alaska plaice (Pleuronectes quadrituberculatus) (AP) (p = 0.002), and arrowtooth flounder (Atheresthes stomias) (ATF) (p = 0.004), with more diverse substrates in low-density areas. Areas of high and low Greenland turbot (Reinhardtius hippoglossoides) (GT) (p = 0.845) abundance had similar sediment textures (primarily mixed sand and mud). Species with highly restricted diets (AP) or piscivores with weak sediment associations (GT, ATF) had relatively inflexible food habits, whereas YFS, RS, and FHS food habits varied considerably with sediment type. Our findings suggest that benthic-feeding pleuronectids prefer certain sediment textures because of adaptive differences in prey availability. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP McConnaughey, RA (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM bob.mcconnaughey@noaa.gov NR 42 TC 67 Z9 69 U1 1 U2 7 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 2000 VL 57 IS 12 BP 2410 EP 2419 DI 10.1139/cjfas-57-12-2410 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 388RY UT WOS:000166196700008 ER PT J AU Garrison, LP Michaels, W Link, JS Fogarty, MJ AF Garrison, LP Michaels, W Link, JS Fogarty, MJ TI Predation risk on larval gadids by pelagic fish in the Georges Bank ecosystem. I. Spatial overlap associated with hydrographic features SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID HADDOCK MELANOGRAMMUS-AEGLEFINUS; COD GADUS-MORHUA; ATLANTIC COD; VERTICAL-DISTRIBUTION; GROWTH; EGGS AB We investigated the relationship between hydrographic variables on Georges Bank and the spatial distribution of larval Atlantic cod (Gadus morhua), larval haddock (Melanogrammus aeglefinus), and two planktivorous fish, Atlantic herring (Clupea harengus) and Atlantic mackerel (Scomber scombrus). We conducted cruises during April-May of 1990, 1994, and 1995 to document spatial distributions and employed logistic regression and a spatial-overlap index to assess relationships between hydrographic variables, spatial distributions and spatial overlap between gadid larvae and planktivorous fish. Cod larvae were more abundant in shallow well-mixed areas, while both haddock larvae and herring were more abundant in stratified areas. Atlantic mackerel occurred in deeper water and had little spatial overlap with the other species. In 1995, the presence of Scotian Shelf water and an intrusion of continental slope water altered temperature and salinity distributions and increased spatial overlap between cod larvae and herring. The stratified areas offer a higher concentration of prey for larval haddock, however there is increased exposure to planktivorous fish predators, creating a potential trade-off between predation and starvation. Due to the high abundance of planktivorous fish and high spatial and temporal overlap, predation is likely an important factor influencing survival of gadid larvae on Georges Bank. 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 35 TC 39 Z9 39 U1 1 U2 7 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 DEC PY 2000 VL 57 IS 12 BP 2455 EP 2469 DI 10.1139/cjfas-57-12-2455 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 388RY UT WOS:000166196700012 ER PT J AU Barbarulo, R Marchand, J Snyder, KA Prene, S AF Barbarulo, R Marchand, J Snyder, KA Prene, S TI Dimensional analysis of ionic transport problems in hydrated cement systems - Part 1. Theoretical considerations SO CEMENT AND CONCRETE RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Transport Properties and Microstructure of Cement-Based Systems CY NOV 29-30, 1999 CL BOSTON, MASSACHUSETTS DE transport properties; modeling; cement systems; reaction ID BINDING ISOTHERMS; CHLORIDE; MIGRATION; DIFFUSION AB The validity of the local equilibrium assumption in hydrated cement systems that a particular chemical reaction is instantaneous with respect to transport is examined using a dimensional analysis of electrochemical transport in cementitious materials. The transport equation parameters are scaled, resulting in a dimensionless equation. The dimensionless coefficient for each reaction/transport term determines its relative contribution to the overall process. The diffusion of ions in a reactive porous medium can be fully described on the basis of six independent dimensionless numbers. The analysis demonstrates that the kinetics of the reaction determine the appropriate time constant for the analysis. The formalism is applied to the dissolution of calcium hydroxide under an electrochemical potential gradient. The results are in agreement with previous observations and demonstrate quantitatively the local equilibrium hypothesis is valid in most practical cases where ions are transported by diffusion through a saturated material. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Laval, Dept Genie Civil, CRIB, St Foy, PQ G1K 7P4, Canada. Elect France, Dept EMA, Div Rech & Dev, F-77250 Moret Sur Loing, France. Natl Inst Stand & Technol, BFRL, Gaithersburg, MD 20899 USA. RP Marchand, J (reprint author), Univ Laval, Dept Genie Civil, CRIB, St Foy, PQ G1K 7P4, Canada. RI Chen, Wei/A-5694-2010 NR 24 TC 17 Z9 17 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD DEC PY 2000 VL 30 IS 12 SI SI BP 1955 EP 1960 DI 10.1016/S0008-8846(00)00383-5 PG 6 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 405LQ UT WOS:000167161300014 ER PT J AU Babushok, V Tsang, W AF Babushok, V Tsang, W TI Inhibitor rankings for alkane combustion SO COMBUSTION AND FLAME LA English DT Article ID AROMATIC HYDROCARBON FORMATION; METHANE-AIR FLAMES; FIRE SUPPRESSANTS; PREMIXED METHANE; BURNING VELOCITIES; OXIDATION; TEMPERATURE AB The effect of hydrocarbon fuel type on the ranking of inhibitor effectiveness has been investigated through computer simulations. The approach involves carrying out sensitivity analysis on the detailed kinetics of the combustion of C-1-C-4 hydrocarbons. Tt is demonstrated that the main reactions determining burning velocities are the same. Similar suppressant rankings from the combustion of different hydrocarbon fuels are largely due to the reactions of a number of small radicals that are common to ail of these systems. Inhibitor addition reduces the concentration of these radicals with the active agents being recycled by the common breakdown products of the fuel. Inhibitor effectiveness of additives in a variety of fuels was analyzed using experimental data on the effects of additives on burning velocity in small additive concentration ranges. An universal ranking of additive efficiency is presented. The results demonstrate that the active agents in practically all cases are the small inorganic compounds created from decomposition processes. Inhibition effectiveness of agents is at a maximum at low concentrations. At higher concentrations, saturation effects, brought about by the approach of active radicals to their equilibrium concentrations, lead to substantial decreases in the effectiveness of high efficiency suppressants in comparison with their effects at small concentrations. The results show that the probable maximum increase in total flame suppression effectiveness of high efficiency agents will not exceed one order of magnitude in molar fractions in comparison with the effect of halon 1301 (CF3Br). (C) 2000 by The Combustion Institute. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Babushok, V (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 64 TC 66 Z9 68 U1 3 U2 19 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 DEC PY 2000 VL 123 IS 4 BP 488 EP 506 DI 10.1016/S0010-2180(00)00168-1 PG 19 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 373QT UT WOS:000165300900003 ER PT J AU Morris, KC Flater, D AF Morris, KC Flater, D TI Design of a flexible, integrated testing system for STEP and OMG standards SO COMPUTER STANDARDS & INTERFACES LA English DT Article DE conformance testing; manufacturing; software; standards AB New software standards supporting integration of manufacturing and engineering systems are emerging at a rapid pace. Two groups, the Object Management Group (OMG) and the community producing the Standard for the Exchange of Product Model Data (STEP, formally known as ISO 10303), dominate in the production of standards for manufacturing and engineering industries. Their standards are based on common methods, which can be exploited in developing tests for systems supporting the standards. This paper describes the methods employed and a system that builds on those methods to support the automatic and rapid development of conformance tests for the emerging standards. (C) 2000 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 16 TC 2 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5489 J9 COMP STAND INTER JI Comput. Stand. Interfaces PD DEC PY 2000 VL 22 IS 5 BP 297 EP 305 DI 10.1016/S0920-5489(00)00057-X PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA 378ZN UT WOS:000165616500002 ER PT J AU Rosenbaum, HC Egan, MG Clapham, PJ Brownell, RL Malik, S Brown, MW White, BN Walsh, P Desalle, R AF Rosenbaum, HC Egan, MG Clapham, PJ Brownell, RL Malik, S Brown, MW White, BN Walsh, P Desalle, R TI Utility of North Atlantic right whale museum specimens for assessing changes in genetic diversity SO CONSERVATION BIOLOGY LA English DT Article ID EUBALAENA-GLACIALIS; POPULATION BOTTLENECK; MITOCHONDRIAL-DNA; EXTINCT; VARIABILITY AB We examined six historical specimens of the endangered North Atlantic right whale (Eubalaena glacialis) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near-exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the species most likely occurred prior to the late nineteenth century. One historical specimen was from the last documented female capable of propagating one of the maternal lineages in the population today; no females in the existing population have been found to carry this mtDNA haplotype. Analysis of the only specimens from the eastern North Atlantic right whale population ever to be examined revealed that eastern and western North Atlantic right whales may not have been genetically differentiated populations. Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest and the six decades of protection have been successful in maintaining much of the maternal lineage diversity that was present in the late nineteenth century. C1 Amer Museum Nat Hist, Mol Systemat Lab, New York, NY 10024 USA. Wildlife Conservat Soc, Bronx, NY 10460 USA. Natl Marine Fisheries Serv, NEFSC, Woods Hole, MA 02543 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. McMaster Univ, Dept Biol, Hamilton, ON L8S 4K1, Canada. Ctr Coastal Studies, Provincetown, MA 02657 USA. East Coast Ecosyst, Toronto, ON M5A 2T5, Canada. RP Rosenbaum, HC (reprint author), Amer Museum Nat Hist, Mol Systemat Lab, 79h St & CPW, New York, NY 10024 USA. NR 25 TC 26 Z9 30 U1 0 U2 5 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD DEC PY 2000 VL 14 IS 6 BP 1837 EP 1842 DI 10.1046/j.1523-1739.2000.99310.x PG 6 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 385ZV UT WOS:000166035800032 ER PT J AU Gazmuri, RJ Hoffner, E Ayoub, IM Epstein, M Kingston, S AF Gazmuri, RJ Hoffner, E Ayoub, IM Epstein, M Kingston, S TI Ventricular fibrillation (VF) worsens ischemia-induced intramyocardial sodium accumulation: Effect of Na+-influx limiting interventions SO CRITICAL CARE MEDICINE LA English DT Meeting Abstract C1 N Chicago VA Med Ctr, N Chicago, IL USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Duquesne Univ, Pittsburgh, IL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD DEC PY 2000 VL 28 IS 12 SU S MA 131 BP A66 EP A66 PG 1 WC Critical Care Medicine SC General & Internal Medicine GA 388ZD UT WOS:000166212200133 ER PT J AU Hodgson, M Brodt, W Henderson, D Loftness, V McCrone, R Roselle, G Rosenfeld, A Woods, J Wright, R AF Hodgson, M Brodt, W Henderson, D Loftness, V McCrone, R Roselle, G Rosenfeld, A Woods, J Wright, R TI Needs and opportunities for improving the health, safety, and productivity of medical research facilities SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Leadership Conference on Biomedical Research and the Environment CY NOV 01-02, 1999 CL BETHESDA, MARYLAND SP Natl Assoc Physicians Environm, Assoc Higher Educ Facil Officers, US Natl Inst Environm Hlth Sci, W Alton Jones Fdn, Mitchell Kapor Fdn, Shulsky Fdn, Hahn Family Fdn, Baxter Int Inc DE best practices; built environment; construction; emerging pathogens; healthy buildings; indoor environment; medical research; occupational health; preventive strategies; productivity; sick building; standards ID SICK-BUILDING SYNDROME; SYMPTOMS; TRANSMISSION; ASTHMA; OFFICE; RISK AB Medical research facilities, indeed all the nation's constructed facilities, must be designed, operated, and maintained in a manner that supports the health, safety, and productivity of the occupants. The National Construction Goals, established by the National Science and Technology Council, envision substantial improvements in occupant health and worker productivity. The existing research and best practices case studies support this conclusion, but too frequently building industry professionals lack the knowledge to design, construct, operate, and maintain facilities at these optimum levels. There is a need for more research and more collaborative efforts between medical and facilities engineering researchers and practitioners in order to attain the National Construction Goals. Such collaborative efforts will simultaneously support attainment of the National Health Goals. This article is the summary report of the Healthy Buildings Committee for the Leadership Conference: Biomedical Facilities and the Environment sponsored by the National institutes of Health, the National Association of Physicians for the Environment, and the Association of Higher Education Facilities Officers on 1-2 November 1999 in Bethesda, Maryland, USA. C1 NIH, Bethesda, MD 20892 USA. Dept Vet Affairs, Washington, DC USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Dept Vet Affairs, Cincinnati, OH USA. Dept Energy, Washington, DC USA. HP Woods Res Inst, Herndon, VA USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Brodt, W (reprint author), NIH, Bldg 13,Rm 2W48, Bethesda, MD 20892 USA. NR 44 TC 1 Z9 1 U1 0 U2 0 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 2000 VL 108 SU 6 BP 1003 EP 1008 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 386TP UT WOS:000166077900008 PM 11124125 ER PT J AU Emmett, R Llanso, R Newton, J Thom, R Hornberger, M Morgan, C Levings, C Copping, A Fishman, P AF Emmett, R Llanso, R Newton, J Thom, R Hornberger, M Morgan, C Levings, C Copping, A Fishman, P TI Geographic signatures of North American West Coast estuaries SO ESTUARIES LA English DT Review ID SAN-FRANCISCO BAY; COLUMBIA RIVER ESTUARY; CLAM POTAMOCORBULA-AMURENSIS; PUGET-SOUND; REMARKABLE INVASION; PACIFIC-NORTHWEST; STANDING STOCK; SALT MARSHES; CALIFORNIA; WASHINGTON AB West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include El Ninos, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97330 USA. Washington Dept Ecol, Olympia, WA 98504 USA. Pacific NW Natl Lab, Battelle Marine Sci Lab, Sequim, WA 98382, Australia. US Geol Survey, Menlo Pk, CA 94025 USA. Oregon State Univ, Cooperat Inst Marine Resource Studies, Newport, OR 97365 USA. Canadian Dept Fisheries Oceans, Pacific Environm Sci Ctr, N Vancouver, BC V7H 1V2, Canada. Univ Washington, Washington Sea Grant Program, Seattle, WA 98105 USA. Fishman Environm Serv, Portland, OR 97209 USA. RP Emmett, R (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97330 USA. EM Robert.Emmett@noaa.gov NR 169 TC 75 Z9 77 U1 3 U2 36 PU ESTUARINE RESEARCH FEDERATION PI PORT REPUBLIC PA 2018 DAFFODIL, PO BOX 510, PORT REPUBLIC, MD 20676 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 2000 VL 23 IS 6 BP 765 EP 792 DI 10.2307/1352998 PG 28 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 400BF UT WOS:000166848200002 ER PT J AU Hicks, BB Valigura, RA Courtright, FB AF Hicks, BB Valigura, RA Courtright, FB TI The role of the atmosphere in coastal ecosystem decline - Future research directions SO ESTUARIES LA English DT Article ID CHESAPEAKE BAY ESTUARY; GASEOUS DRY DEPOSITION; NITROGEN DEPOSITION; UNITED-STATES; ORGANIC CONTAMINANTS; SURFACE RESISTANCES; MODELING SYSTEM; FLUXES; INPUTS; EUTROPHICATION AB Current assessments of the role of atmospheric deposition in the declining health of aquatic ecosystems indicate that the atmosphere could account for as much as 30% to 40% of total external nitrogen loading to some coastal waters. All such assessments are uncertain and need to be refined. To focus attention on the problem as it affects eastern North American coastal waters, a series of interdisciplinary workshops has been conducted, bringing together scientists and regulators. The series started with a meeting at Mt. Washington, Maryland in 1994, with subsequent meetings at Warrenton, Virginia in 1995, and Raleigh, North Carolina in 1997. Although the workshops considered all nitrogen species, toxic chemicals, trace metals, precipitation chemistry, airborne aerosols, and supporting meteorological investigation, most of the discussion centered around the issue of nitrogen-species deposition. It was concluded that work is urgently needed to establish integrated monitoring stations to provide high quality deposition and watershed retention data within the catchment area, to take spatial and temporal variability into account in atmospheric deposition models, to improve biogeochemical watershed models, especially from the perspective of biological utilization and cycling of deposited materials, to refine emissions inventories and projections on which scenario investigations are based, to enhance all ongoing data collection efforts, especially those related to specific process studies, and to improve spatial resolution by increasing the number of deposition measurement sites. An overall conclusion was that there must be a strong effort to include considerations of air pollution and atmospheric deposition in the water quality regulatory process. It was repeatedly emphasized that any new efforts should build on existing programs rather than risk new starts that compete with ongoing and already productive work. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. Maryland Dept Environm, Baltimore, MD 21224 USA. RP Hicks, BB (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. EM bruce.hicks@noaa.gov NR 44 TC 9 Z9 9 U1 0 U2 4 PU ESTUARINE RESEARCH FEDERATION PI PORT REPUBLIC PA 2018 DAFFODIL, PO BOX 510, PORT REPUBLIC, MD 20676 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 2000 VL 23 IS 6 BP 854 EP 863 DI 10.2307/1353002 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 400BF UT WOS:000166848200006 ER PT J AU O'Shea, ML Brosnan, TM AF O'Shea, ML Brosnan, TM TI Trends in indicators of eutrophication in Western Long Island sound and the Hudson-Raritan Estuary SO ESTUARIES LA English DT Article ID NEW-YORK; DISSOLVED-OXYGEN; SEWAGE ABATEMENT; WATER-QUALITY; RIVER; NUTRIENTS; HYPOXIA; DEPLETION AB Significant improvements in water quality have been observed for several decades throughout much of the Hudson-Raritan Estuary, primarily as a result of regional abatement of municipal and industrial discharges. These improvements include area-wide, order-of-magnitude reductions in ambient coliform concentrations and significant increases in dissolved oxygen (DO) concentrations. In contrast to these improvements, DO in bottom waters of the western Long Island Sound (WLIS) appears to have decreased in the last two decades. Although there is no consensus as to why hypoxia in WLIS may have recently become more severe, several related hypotheses have been suggested, including an increase in eutrophication, increased density stratification, and changes in wastewater loads. To determine if eutrophication has increased in WLIS, trends in several indicators of eutrophication were examined from a long-term water quality data set. Since the mid-1980s surface DO supersaturation has increased, bottom minimum DO has decreased, and vertical DO stratification has increased in WLIS. Other areas of the Hudson-Raritan Estuary, such as Jamaica Bay and Raritan Bay, exhibit similar evidence of declining water quality and may be experiencing increasing eutrophication. Temporal changes in vertical density stratification indicate that surface to bottom temperature differences have increased to a greater extent and have had a more significant impact on bottom DO depletion in WLIS than in the shallower Jamaica Bay and Raritan Bay. Additional factors contributing to the observed decline in water quality include recent changes in wastewater loads and possible increases in upstream and nonpoint source loads. C1 US EPA, Water Supply & Water Resource Div, Natl Risk Mangement Res Lab,Agcy Off Res & Dev, Urban Watershed Management Branch, Edison, NJ 08837 USA. NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP O'Shea, ML (reprint author), US EPA, Water Supply & Water Resource Div, Natl Risk Mangement Res Lab,Agcy Off Res & Dev, Urban Watershed Management Branch, Edison, NJ 08837 USA. NR 100 TC 32 Z9 32 U1 4 U2 14 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 2000 VL 23 IS 6 BP 877 EP 901 DI 10.2307/1353004 PG 25 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 400BF UT WOS:000166848200008 ER PT J AU Williams, EH Quinn, TJ AF Williams, EH Quinn, TJ TI Pacific herring, Clupea pallasi, recruitment in the Bering Sea and north-east Pacific Ocean, I: relationships among different populations SO FISHERIES OCEANOGRAPHY LA English DT Article DE Bering Sea; multivariate cluster analysis; north-east Pacific Ocean; Pacific herring; recruitment; weight-at-age; year-class strength ID HARENGUS-PALLASI AB We examined recruitment and average weight-at-age rime series for Pacific herring (Clupea pallasi) populations from the Bering Sea and north-east Pacific Ocean to determine similarities. Statistical correlation and multivariate clustering methods indicated Pacific herring populations form large-scale groups. Large year classes occur synchronously among several Pacific herring populations. Multivariate cluster analyses of recruitment and weight-at-age data indicated that Bering Sea herring populations are distinct from north-east Pacific Ocean populations. Within the NE Pacific Ocean, there appear to be three groups of herring populations: a British Columbia group, a south-east Alaska coastal group, and an outer Gulf of Alaska group. Jackknife and randomization tests indicate these groups are robust and not the result of random chance. Deviations from observed herring population groups were examined for indications of anthropogenic perturbations. The Prince William Sound herring populations did not show any strong deviations corresponding to the oil spill of 1989. There might not yet be enough data since the spill to detect changes in the recruitment or weight-at-age data since that time, particularly if oil spill effects were concentrated on the early life history stages. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, Tiburon, CA 94920 USA. Univ Alaska, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. RP Williams, EH (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, 3150 Paradise Dr, Tiburon, CA 94920 USA. EM Erik.Williams@noaa.gov NR 26 TC 16 Z9 17 U1 2 U2 9 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD DEC PY 2000 VL 9 IS 4 BP 285 EP 299 DI 10.1046/j.1365-2419.2000.00145.x PG 15 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 414RN UT WOS:000167680100001 ER PT J AU Williams, EH Quinn, TJ AF Williams, EH Quinn, TJ TI Pacific herring, Clupea pallasi, recruitment in the Bering Sea and north-east Pacific Ocean, II: relationships to environmental variables and implications for forecasting SO FISHERIES OCEANOGRAPHY LA English DT Article DE Baring Sea; environmental variable; forecasting; north-east Pacific Ocean; Pacific herring; recruitment; spawner-recruit model ID HARENGUS-PALLASI; BRITISH-COLUMBIA; TEMPERATURE; MORTALITY; LARVAE; POPULATIONS; MANAGEMENT; DISCHARGE; ATLANTIC; GEORGIA AB Previous studies have shown that Pacific herring populations in the Bering Sea and north-east Pacific Ocean can be grouped based on similar recruitment time series. The scale of these groups suggests large-scale influence on recruitment fluctuations from the environment. Recruitment time series from 14 populations were analysed to determine links to various environmental variables and to develop recruitment forecasting models using a Ricker-type environmentally dependent spawner-recruit model. The environmental variables used for this investigation included monthly time series of the following: southern oscillation index, North Pacific pressure index, sea surface temperatures, air temperatures, coastal upwelling indices, Bering Sea wind, Bering Sea ice cover, and Bering Sea bottom temperatures. Exploratory correlation analysis was used for focusing the time period examined for each environmental variable. Candidate models for forecasting herring recruitment were selected by the ordinary and recent cross-validation prediction errors. Results indicated that forecasting models using air and sea surface temperature data lagged to the year of spawning generally produced the best forecasting models. Multiple environmental variables showed marked improvements in prediction over single-environmental-variable model. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, Tiburon, CA 94920 USA. Univ Alaska, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. RP Williams, EH (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Tiburon Lab, 3150 Paradise Dr, Tiburon, CA 94920 USA. NR 61 TC 21 Z9 21 U1 2 U2 9 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 DEC PY 2000 VL 9 IS 4 BP 300 EP 315 DI 10.1046/j.1365-2419.2000.00146.x PG 16 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 414RN UT WOS:000167680100002 ER PT J AU Horne, JK AF Horne, JK TI Acoustic approaches to remote species identification: a review SO FISHERIES OCEANOGRAPHY LA English DT Review DE acoustics; backscatter amplitude; species identification; target strength ID COD GADUS-MORHUA; VOLUME SCATTERING STRENGTHS; FREQUENCY SOUND-SCATTERING; FISH SIZE DISTRIBUTIONS; ECHO PEAK PDF; TARGET-STRENGTH; ATLANTIC COD; FISHERIES ACOUSTICS; CYNOSCION REGALIS; SWIMMING BEHAVIOR AB Noninvasive species identification remains a longterm goal of fishers, researchers, and resource managers who use sound to locate, map, and count aquatic organisms. Since the first biological applications of underwater acoustics, four approaches have been used singly or in combination to survey marine and freshwater environments: passive sonar; prior knowledge and direct sampling; echo statistics from high-frequency measures; and matching models to low-frequency measures, Echo amplitudes or targets measured using any sonar equipment are variable signals. Variability in reflected sound is influenced by physical factors associated with the transmission of sound through a compressible fluid, and by biological factors associated with the location, reflective properties, and behaviour of a target. The current trend in acoustic target identification is to increase the amount of information collected through increases in frequency bandwidth or in the number of acoustic beams. Exclusive use of acoustics to identify aquatic organisms reliably will require a set of statistical metrics that discriminate among a aide range of similar body types at any packing density, and incorporation of these algorithms in routine data processing. C1 Univ Michigan, Ann Arbor, MI 48109 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Horne, JK (reprint author), Univ Washington, 7600 Sand Point Way NE,Bldg 4, Seattle, WA 98115 USA. NR 190 TC 92 Z9 96 U1 3 U2 34 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 DEC PY 2000 VL 9 IS 4 BP 356 EP 371 DI 10.1046/j.1365-2419.2000.00143.x PG 16 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 414RN UT WOS:000167680100006 ER PT J AU Johnson, AN Wright, JD Nakao, S Merkle, CL Moldover, MR AF Johnson, AN Wright, JD Nakao, S Merkle, CL Moldover, MR TI The effect of vibrational relaxation on the discharge coefficient of critical flow venturis SO FLOW MEASUREMENT AND INSTRUMENTATION LA English DT Article ID TRANSFER STANDARD; RATES; GAS AB This paper identifies a new mechanism that can affect the discharge coefficient of critical nozzle flows. Specifically, vibrational relaxation effects are demonstrated to significantly influence the discharge coefficient of selected gases in critical venturi flows. This phenomenon explains why certain gases - like carbon dioxide - exhibit calibration characteristics that differ significantly from other gases (e.g., N-2, O-2, Ar, He, and H-2). A mathematical model is developed which predicts this behavior, and vibrational non-equilibrium effects are further substantiated by two independent experiments. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Johnson, AN (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 32 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-5986 J9 FLOW MEAS INSTRUM JI Flow Meas. Instrum. PD DEC PY 2000 VL 11 IS 4 BP 315 EP 327 DI 10.1016/S0955-5986(00)00004-2 PG 13 WC Engineering, Mechanical; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 363QX UT WOS:000089847000009 ER PT J AU Farrugia, CJ Singer, HJ Evans, D Berdichevsky, D Scudder, JD Ogilvie, KW Fitzenreiter, RJ Russell, CT AF Farrugia, CJ Singer, HJ Evans, D Berdichevsky, D Scudder, JD Ogilvie, KW Fitzenreiter, RJ Russell, CT TI Response of the equatorial and polar magnetosphere to the very tenuous solar wind on May 11, 1999 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RAIN; PRECIPITATION AB We examine effects in the equatorial and polar magnetosphere during 9-13 May, 1999. Earth's field at geostationary orbit became closely dipolar for similar to 16 hours when solar wind densities n(sw) were < 1 cm(-3) Electron precipitation in the northern polar cap intensified as n(sw) decreased, with significant fluxes up to similar to 15 keV energy on May 11. The simultaneous precipitation void in the southern polar cap implies a very pronounced north-south asymmetry, also reflected in the hemispherical power deposition. With an intense and collimated strahl, these observations support the ideas of Fairfield and Scudder [1985] on the preferential entry of the strahl into the northern hemisphere under the observed IMF away sector as a source of the north-south precipitation asymmetry. The polar rain north-south asymmetry argues against an ejecta source for the solar wind drop-out. The temporal profiles of solar wind parameters were very asymmetric with respect to the time of minimum n(sw), and strong compressions and substorm activity prevailed as n(sw) recovered. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. NOAA, Space Environm Ctr, Boulder, CO USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Raytheon ITSS, Lanham, MD USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Farrugia, CJ (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RI Scudder, Jack/D-8417-2013; OI Scudder, Jack/0000-0001-7975-5630; Russell, Christopher/0000-0003-1639-8298 NR 8 TC 21 Z9 21 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 DEC 1 PY 2000 VL 27 IS 23 BP 3773 EP 3776 DI 10.1029/2000GL003800 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700004 ER PT J AU Chilson, PB Belova, E Rietveld, MT Kirkwood, S Hoppe, UP AF Chilson, PB Belova, E Rietveld, MT Kirkwood, S Hoppe, UP TI First artificially induced modulation of PMSE using the EISCAT heating facility SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR MESOSPHERE; AEROSOLS AB A coordinated experiment involving ionospheric heating and VHF observations of polar mesosphere summer echoes (PMSE) has recently been conducted at the EISCAT facility near Tromso, Norway. We have demonstrated for the first time that ionospheric heating can influence VHF radar returns associated with PMSE. Artificially elevating the electron temperatures within the PMSE layer has been shown to reduce the echo power. Based on this and other results from the experiment, it is suggested that the observed reduction in PMSE power is related to an enhancement of the electron diffusivity through the heating. C1 Swedish Inst Space Phys, MRI Atmospher Res Programme, S-98128 Kiruna, Sweden. EISCAT, Ramfjordbotn, Norway. Max Planck Inst Aeron, Katlenburg Lindau, Germany. Swedish Inst Space Phys, MRI Atmospher Res Programme, Kiruna, Sweden. Norwegian Def Res Estab, Kjeller, Norway. RP Chilson, PB (reprint author), Univ Colorado, NOAA, CIRES, Boulder, CO 80309 USA. NR 9 TC 76 Z9 76 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 2000 VL 27 IS 23 BP 3801 EP 3804 DI 10.1029/2000GL011897 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700011 ER PT J AU Lee, AM Roscoe, HK Oltmans, S AF Lee, AM Roscoe, HK Oltmans, S TI Model and measurements show Antarctic ozone loss follows edge of polar night SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEPLETION; VORTEX AB A three-dimensional chemical-transport model of the stratosphere has been used to study the 1996 austral winter and spring. Both the model and ozonesonde measurements show that ozone depletion associated with the Antarctic ozone hole follows the edge of polar night: very little ozone-depleted air mixes ahead of the terminator as it sweeps poleward, until the terminator reaches 80 degreesS. Other details of the model ozone field show very good agreement with measurements. C1 Univ Cambridge, Ctr Atmospher Sci, Dept Chem, Cambridge CB2 1EW, England. British Antarctic Survey, NERC, Cambridge CB3 0ET, England. NOAA, CMDL, Boulder, CO USA. RP Lee, AM (reprint author), Univ Cambridge, Ctr Atmospher Sci, Dept Chem, Lensfield Rd, Cambridge CB2 1EW, England. NR 14 TC 17 Z9 17 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 DEC 1 PY 2000 VL 27 IS 23 BP 3845 EP 3848 DI 10.1029/2000GL011441 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700022 ER PT J AU Custer, TG Kato, S Fall, R Bierbaum, VM AF Custer, TG Kato, S Fall, R Bierbaum, VM TI Negative ion mass spectrometry and the detection of carbonyls and HCN front clover SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VOLATILE ORGANIC-COMPOUNDS; GAS-PHASE; HYDROGEN-CYANIDE; CHEMISTRY; EMISSIONS; ACETONE; ANION; AIR AB We have demonstrated that negative ion-chemical ionization mass spectrometry (NI-CIMS) can be used to distinguish several isomeric volatile organic compounds (VOCs) that are emitted from wounded plants. Reaction chemistry with HO-, hydrogen/deuterium exchange patterns, and collision-induced dissociation spectra allow identification of the isomers. Laboratory studies of emissions from wounded clover using NI-CIMS show several previously detected VOCs, but also clearly demonstrate the emission of HCN. This compound is presumably formed by the decomposition of cyanogenic glycosides which also form aldehyde and ketone byproducts. These results suggest that NI-CIMS may be a valuable tool for investigating VOCs and HCN release from vegetation. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Custer, TG (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. NR 24 TC 10 Z9 10 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 2000 VL 27 IS 23 BP 3849 EP 3852 DI 10.1029/2000GL011873 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700023 ER PT J AU Wilson, RJ AF Wilson, RJ TI Evidence for diurnal period Kelvin waves in the Martian atmosphere from Mars Global Surveyor TES data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Midlevel (similar to 25 km) atmospheric temperatures derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) spectra indicate the presence of stationary waves and thermal tides. Stationary waves are prominent, at middle to high latitudes where westerly zonal flow is indicated by the meridional temperature gradient. Longitudinal variability within 30 degreesS to 30 degreesN is dominated by topographically-forced nonmigrating thermal tides that have westward and eastward propagating components. The MGS mapping data are available at two fixed local times so that it is not possible to distinguish between these components or isolate the sun-synchronous tide. A comparison with Mars general circulation model (MGCM) simulations suggests that the observed wave patterns are consistent with the presence of eastward propagating, diurnal period Kelvin waves with zonal wavenumbers one and two. These waves can propagate to great heights and may account for observed zonal variations in thermospheric density. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Wilson, RJ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 12 TC 51 Z9 51 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 DEC 1 PY 2000 VL 27 IS 23 BP 3889 EP 3892 DI 10.1029/2000GL012028 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700033 ER PT J AU Min, DH Bullister, JL Weiss, RF AF Min, DH Bullister, JL Weiss, RF TI Constant ventilation age of thermocline water in the eastern subtropical North Pacific Ocean from chlorofluorocarbon measurements over a 12-year period SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CIRCULATION; SEAWATER; CCL2F2; CCL3F AB Northeastern Pacific chlorofluorocarbon (CFC) data collected between 1982 and 1994 near Geochemical Ocean Sections Study (GEOSECS) station 1 (28.5 degreesN, 122.5 degreesW) record decadal timescale ventilation processes of the subtropical thermocline in this region. The CFC-12 concentration age field versus potential density has been remarkably constant over the 12-year period, although CFC concentrations in the upper kilometer of the water column have increased with time. Results from a simple one-dimensional advection-diffusion model are consistent with an advection velocity of ca. 0.8-0.9 cm s(-1) from the source area. The influence of the 1982-83 El Nino is noticeable in the 1983 observations. While the main stream of subarctic source water al,pears to spread southward at a constant rate, during El Nino years the influence of comparatively CFC-free tropical thermocline waters is enhanced in this region, leading to reduced vertical inventories of CFCs, but without changing the apparent CFC ages as functions of potential density. Apparent oxygen utilization rates decrease with increasing CFC age, and also appear not to have changed significantly ol er the 12-year measurement period. C1 Univ Calif Davis, Scripps Inst Oceanog, Davis, CA 95616 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Min, DH (reprint author), Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. NR 19 TC 8 Z9 8 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 DEC 1 PY 2000 VL 27 IS 23 BP 3909 EP 3912 DI 10.1029/1999GL011318 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700038 ER PT J AU Soler, T Foote, RH Hoyle, D Bocean, V AF Soler, T Foote, RH Hoyle, D Bocean, V TI Accurate GPS orientation of a long baseline for neutrino oscillation experiments at Fermilab SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Recent research in elementary particle physics is concentrating a great amount of effort on neutrino oscillation experiments. These studies require the accurate pointing of neutrino beams between two distant points. The Fermi National Accelerator Laboratory (Fermilab) intends to build a new particle beamline to direct a beam of muon neutrinos from its Main Injector toward a far-off (735 km away) underground detector capable of searching for non-zero neutrino mass by looking for neutrino oscillations. This paper describes the GPS work carried out to accurately position the reference ground marks at the two sites from which the spatial orientation of the baseline can be accurately determined. The effect of plate rotations on the absolute orientation of the baseline was also investigated. C1 NOAA, NOS, Natl Geodet Survey, Silver Spring, MD 20910 USA. Fermi Natl Accelerator Lab, Ctr Tech, Batavia, IL 60510 USA. RP Soler, T (reprint author), NOAA, NOS, Natl Geodet Survey, 1315 EW Highway, Silver Spring, MD 20910 USA. RI Soler, Tomas/F-6386-2010 NR 10 TC 2 Z9 2 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 DEC 1 PY 2000 VL 27 IS 23 BP 3921 EP 3924 DI 10.1029/2000GL011539 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700041 ER PT J AU Sarmiento, JL Monfray, P Maier-Reimer, E Aumont, O Murnane, RJ Orr, JC AF Sarmiento, JL Monfray, P Maier-Reimer, E Aumont, O Murnane, RJ Orr, JC TI Sea-air CO2 fluxes and carbon transport: A comparison of three ocean general circulation models SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC CO2; GLOBAL OCEAN; WORLD OCEAN; INTERHEMISPHERIC TRANSPORT; HEAT TRANSPORTS; NORTH-ATLANTIC; BERING STRAIT; STEADY-STATE; DIOXIDE; CYCLE AB Many estimates of the atmospheric carbon budget suggest that most of the sink for CO2 produced by fossil fuel burning and cement production must be in the Northern Hemisphere. Keeling et al. [1989] hypothesized that this asymmetry could be explained instead by a northward preindustrial transport of similar to1 Pg C y(-1) in the atmosphere balanced by an equal and opposite southward transport in the ocean. We explore this hypothesis by examining the processes that determine the magnitude of the preindustrial interhemispheric flux of carbon in three ocean carbon models. This study is part of the first stage of the Ocean Carbon Model Intercomparison Project organized by International Geosphere Biosphere Programme Global Analysis, Interpretation, and Modelling Task Force, We find that the combination of interhemispheric heat transport (with its associated carbon transport), a finite gas exchange, and the biological pump, yield a carbon flux of only -0.12 to +0.04 Pg C y(-1) across the equator (positive to the north). An important reason for the low carbon transport is the decoupling of the carbon flux from the interhemispheric heat transport due to the long sea-air equilibration time for surface CO2. A possible additional influence on the interhemispheric exchange is oceanic transport of carbon from rivers. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. Commissariat Energie Atom, CNRS, Lab Sci Climat & Environm, Saclay, France. Max Planck Inst Meteorol, Hamburg, Germany. RP Sarmiento, JL (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Sayre Hall,Forrestal Campus,POB CN710, Princeton, NJ 08544 USA. RI Orr, James/C-5221-2009; Aumont, Olivier/G-5207-2016; OI Aumont, Olivier/0000-0003-3954-506X; Orr, James/0000-0002-8707-7080 NR 61 TC 52 Z9 55 U1 1 U2 14 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 DEC PY 2000 VL 14 IS 4 BP 1267 EP 1281 DI 10.1029/1999GB900062 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 391EK UT WOS:000166341000021 ER PT J AU Suntharalingam, P Sarmiento, JL Toggweiler, JR AF Suntharalingam, P Sarmiento, JL Toggweiler, JR TI Global significance of nitrous-oxide production and transport from oceanic low-oxygen zones: A modeling study SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID WORLD OCEAN; INTERHEMISPHERIC TRANSPORT; NORTH-ATLANTIC; PACIFIC-OCEAN; ARABIAN SEA; EL-NINO; NITRIFICATION; CARBON; HEAT; N2O AB Recent studies of marine nitrous oxide have focused attention on the suboxic and low-oxygen zones associated with ocean basin eastern boundaries. It has been suggested that complex N2O cycling mechanisms in these regions magi provide a net source to the oceanic interior and a significant portion of the ocean-atmosphere flux. In this study we evaluate the global significance of N2O formation in these regions. N2O is treated as a nonconserved tracer in an ocean general circulation model; a simple source function is developed which models NaO production as a function of organic matter remineralization and local oxygen concentration. Model results are evaluated against both surface and deep observational data sets. The oceanic oxygen minimum zones are predominantly found in the upper water column of tropical latitudes and overlain by regions of strong: upwelling in the surface ocean. Simulations of increased N2O production under low-oxygen conditions indicate that the majority of the N2O thus formed escapes directly to the atmosphere and is not subject to significant meridional transport. Results indicate that while enhanced N2O production in these regions cannot be held accountable for the majority of the sea-air flux and interior distribution, it may, however, have significance for the local distribution anti provide as much as 25-50% of the global oceanic source. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Suntharalingam, P (reprint author), Harvard Univ, Dept Earth & Planetary Sci, Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA. NR 54 TC 43 Z9 45 U1 2 U2 17 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 DEC PY 2000 VL 14 IS 4 BP 1353 EP 1370 DI 10.1029/1999GB900100 PG 18 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 391EK UT WOS:000166341000026 ER PT J AU Fleming, MD Chapin, FS Cramer, W Hufford, GL Serreze, MC AF Fleming, MD Chapin, FS Cramer, W Hufford, GL Serreze, MC TI Geographic patterns and dynamics of Alaskan climate interpolated from a sparse station record SO GLOBAL CHANGE BIOLOGY LA English DT Article DE climate; Alaska; global change; temperature; precipitation AB Data from a sparse network of climate stations in Alaska were interpolated to provide 1-km resolution maps of mean monthly temperature and precipitation-variables that are required at high spatial resolution for input into regional models of ecological processes and resource management. The interpolation model is based on thin-plate smoothing splines, which uses the spatial data along with a digital elevation model to incorporate local topography. The model provides maps that are consistent with regional climatology and with patterns recognized by experienced weather forecasters. The broad patterns of Alaskan climate are well represented and include latitudinal and altitudinal trends in temperature and precipitation and gradients in continentality. Variations within these broad patterns reflect both the weakening and reduction in frequency of low-pressure centres in their eastward movement across southern Alaska during the summer, and the shift of the storm tracks into central and northern Alaska in late summer. Not surprisingly, apparent artifacts of the interpolated climate occur primarily in regions with few or no stations. The interpolation model did not accurately represent low-level winter temperature inversions that occur within large valleys and basins. Along with well-recognized climate patterns, the model captures local topographic effects that would not be depicted using standard interpolation techniques. This suggests that similar procedures could be used to generate high-resolution maps for other high-latitude regions with a sparse density of data. C1 USGS EROS Field Off, Anchorage, AK 99508 USA. Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. Potsdam Inst Climate Impact Res, D-14412 Potsdam, Germany. Natl Weather Serv, Anchorage, AK 99513 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Fleming, MD (reprint author), USGS EROS Field Off, 4230 Univ Dr, Anchorage, AK 99508 USA. RI Cramer, Wolfgang/B-8221-2008 OI Cramer, Wolfgang/0000-0002-9205-5812 NR 33 TC 39 Z9 40 U1 1 U2 11 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 DEC PY 2000 VL 6 SU 1 BP 49 EP 58 DI 10.1046/j.1365-2486.2000.06008.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 399FA UT WOS:000166799900004 ER PT J AU Eugster, W Rouse, WR Pielke, RA McFadden, JP Baldocchi, DD Kittel, TGF Chapin, FS Liston, GE Vidale, PL Vaganov, E Chambers, S AF Eugster, W Rouse, WR Pielke, RA McFadden, JP Baldocchi, DD Kittel, TGF Chapin, FS Liston, GE Vidale, PL Vaganov, E Chambers, S TI Land-atmosphere energy exchange in Arctic tundra and boreal forest: available data and feedbacks to climate SO GLOBAL CHANGE BIOLOGY LA English DT Review DE Arctic tundra; boreal forest; circumpolar high-latitudes; climate feedbacks; eddy covariance flux data; surface energy balance ID WILLOW BIRCH FOREST; BLACK SPRUCE FOREST; HUDSON-BAY LOWLANDS; WATER-BALANCE; EASTERN SIBERIA; CARBON-DIOXIDE; EDDY-CORRELATION; NET-RADIATION; PINE FOREST; SEASONAL-VARIATION AB This paper summarizes and analyses available data on the surface energy balance of Arctic tundra and boreal forest. The complex interactions between ecosystems and their surface energy balance are also examined, including climatically induced shifts in ecosystem type that might amplify or reduce the effects of potential climatic change. High latitudes are characterized by large annual changes in solar input. Albedo decreases strongly from winter, when the surface is snow-covered, to summer, especially in nonforested regions such as Arctic tundra and boreal wetlands. Evapotranspiration (Q(E)) of high-latitude ecosystems is less than from a freely evaporating surface and decreases late in the season, when soil moisture declines, indicating stomatal control over Q(E), particularly in evergreen forests. Evergreen conifer forests have a canopy conductance half that of deciduous forests and consequently lower Q(E) and higher sensible heat flux (Q(H)), There is a broad overlap in energy partitioning between Arctic and boreal ecosystems, although Arctic ecosystems and light taiga generally have higher ground heat flux because there is less leaf and stem area to shade the ground surface, and the thermal gradient from the surface to permafrost is steeper. Permafrost creates a strong heat sink in summer that reduces surface temperature and therefore heat flux to the atmosphere. Loss of permafrost would therefore amplify climatic warming. If warming caused an increase in productivity and leaf area, or fire caused a shift from evergreen to deciduous forest, this would increase Q(E) and reduce Q(H). Potential future shifts in vegetation would have varying climate feedbacks, with largest effects caused by shifts from boreal conifer to shrubland or deciduous forest (or vice versa) and from Arctic coastal to wet tundra. An increase of logging activity in the boreal forests appears to reduce Q(E) by roughly 50% with little change in Q(H), while the ground heat flux is strongly enhanced. C1 Univ Bern, Inst Geog, CH-3012 Bern, Switzerland. McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4K1, Canada. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. NOAA, ERL, ATDD, Oak Ridge, TN 37831 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. Russian Acad Sci, Inst Forestry, Krasnoyarsk 660036, Russia. RP Eugster, W (reprint author), Univ Bern, Inst Geog, Hallerstr 12, CH-3012 Bern, Switzerland. EM eugster@giub.unibe.ch RI Pielke, Roger/A-5015-2009; Eugster, Werner/E-5116-2010; Kittel, Timothy/F-2792-2011; Baldocchi, Dennis/A-1625-2009; OI Eugster, Werner/0000-0001-6067-0741; Kittel, Timothy/0000-0002-4153-1006; Baldocchi, Dennis/0000-0003-3496-4919; Chapin III, F Stuart/0000-0002-2558-9910; Vidale, Pier Luigi/0000-0002-1800-8460 NR 132 TC 200 Z9 207 U1 18 U2 126 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD DEC PY 2000 VL 6 SU 1 BP 84 EP 115 DI 10.1046/j.1365-2486.2000.06015.x PG 32 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 399FA UT WOS:000166799900007 ER PT J AU Oechel, WC Vourlitis, GL Verfaillie, J Crawford, T Brooks, S Dumas, E Hope, A Stow, D Boynton, B Nosov, V Zulueta, R AF Oechel, WC Vourlitis, GL Verfaillie, J Crawford, T Brooks, S Dumas, E Hope, A Stow, D Boynton, B Nosov, V Zulueta, R TI A scaling approach for quantifying the net CO2 flux of the Kuparuk River Basin, Alaska SO GLOBAL CHANGE BIOLOGY LA English DT Article DE Arctic; global change; ecophysiology; eddy covariance; trace-gas flux; tundra ID ARCTIC TUNDRA ECOSYSTEMS; CARBON-DIOXIDE FLUX; TUSSOCK TUNDRA; PRIMARY PRODUCTIVITY; VEGETATION INDEX; ATMOSPHERIC CO2; CLIMATE-CHANGE; ENERGY FLUXES; REGIONS; MODEL AB Net CO2 flux measurements conducted during the summer and winter of 1994-96 were scaled in space and time to provide estimates of net CO2 exchange during the 1995-96 (9 May 1995-8 May 1996) annual cycle for the Kuparuk River Basin, a 9200 km(2) watershed located in NE Alaska. Net CO2 flux was measured using dynamic chambers and eddy covariance in moist-acidic, nonacidic, wet-sedge, and shrub tundra, which comprise 95% of the terrestrial landscape of the Kuparuk Basin. CO2 flux data were used as input to multivariate models that calculated instantaneous and daily rates of gross primary production (GPP) and whole-ecosystem respiration (R) as a function of meteorology and ecosystem development. Net CO2 flux was scaled up to the Kuparuk Basin using a geographical information system (GIS) consisting of a vegetation map, digital terrain map, dynamic temperature and radiation fields, and the models of GPP and R. Basin-wide estimates of net CO2 exchange for the summer growing season (9 May-5 September 1995) indicate that nonacidic tundra was a net sink of -31.7+/-21.3 GgC (1 Gg = 10(9) g), while shrub tundra lost 32.5+/-6.3 GgC to the atmosphere (negative values denote net ecosystem CO2 uptake). Acidic and wet sedge tundra were in balance, and when integrated for the entire Kuparuk River Basin (including aquatic surfaces), whole basin summer net CO2 exchange was estimated to be in balance (-0.9 +/- 50.3 GgC). Autumn to winter (6 September 1995-8 May 1996) estimates of net CO2 flux indicate that acidic, nonacidic, and shrub tundra landforms were all large sources of CO2 to the atmosphere (75.5 +/- 8.3, 96.4 +/- 11.4, and 43.3 +/- 4.7 GgC for acidic, nonacidic, and shrub tundra, respectively). CO2 loss from wet sedge surfaces was not substantially different from zero, but the large losses from the other terrestrial landforms resulted in a whole basin net CO2 loss of 217.2 +/- 24.1 GgC during the 1995-96 cold season. When integrated for the 1995-96 annual cycle, acidic (66.4+/-25.25 GgC), nonacidic (64.7+/-29.2 GgC), and shrub tundra (75.8 +/- 8.4 GgC) were substantial net sources of COP to the atmosphere, while wet sedge tundra was in balance (0.4+0.8 GgC). The Kuparuk River Basin as a whole was estimated to be a net CO2 source of 218.1 +/- 60.6 GgC over the 1995-96 annual cycle. Compared to direct measurements of regional net COP flux obtained from aircraft-based eddy covariance, the scaling procedure provided realistic estimates of CO2 exchange during the summer growing season. Although winter estimates could not be assessed directly using aircraft measurements of net COP exchange, the estimates reported here are comparable to measured values reported in the literature. Thus, we have high confidence in the summer estimates of net CO2 exchange and reasonable confidence in the winter net CO2 flux estimates terrestrial landforms of the Kuparuk river basin. Although there is larger uncertainty in the aquatic estimates, the small surface area of aquatic surfaces in the Kuparuk river basin (approximate to5%) presumably reduces the potential for this uncertainty to result in large errors in basin-wide CO2 flux estimates. C1 San Diego State Univ, Dept Biol, Global Change Res Grp, San Diego, CA 92182 USA. Calif State Univ, Biol Sci Program, San Marcos, CA 92096 USA. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. San Diego State Univ, Dept Geog, San Diego, CA 92182 USA. RP Oechel, WC (reprint author), San Diego State Univ, Dept Biol, Global Change Res Grp, San Diego, CA 92182 USA. RI Oechel, Walter/F-9361-2010; Dumas, Edward/C-6669-2016 OI Oechel, Walter/0000-0002-3504-026X; Dumas, Edward/0000-0002-9154-9052 NR 53 TC 55 Z9 56 U1 3 U2 22 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 DEC PY 2000 VL 6 SU 1 BP 160 EP 173 DI 10.1046/j.1365-2486.2000.06018.x PG 14 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 399FA UT WOS:000166799900011 ER PT J AU Chapin, FS McGuire, AD Randerson, J Pielke, R Baldocchi, D Hobbie, SE Roulet, N Eugster, W Kasischke, E Rastetter, EB Zimov, SA Running, SW AF Chapin, FS McGuire, AD Randerson, J Pielke, R Baldocchi, D Hobbie, SE Roulet, N Eugster, W Kasischke, E Rastetter, EB Zimov, SA Running, SW TI Arctic and boreal ecosystems of western North America as components of the climate system SO GLOBAL CHANGE BIOLOGY LA English DT Article DE arctic; boreal forest; carbon balance; energy exchange; methane flux; vegetation change ID ATMOSPHERIC CO2; CARBON-CYCLE; FORESTS; TUNDRA; SINK; PLEISTOCENE; EXCHANGE; BALANCE; ALASKA; BUDGET AB Synthesis of results from several Arctic and boreal research programmes provides evidence for the strong role of high-latitude ecosystems in the climate system. Average surface air temperature has increased 0.3 degreesC per decade during the twentieth century in the western North American Arctic and boreal forest zones. Precipitation has also increased, but changes in soil moisture are uncertain. Disturbance rates have increased in the boreal forest; for example, there has been a doubling of the area burned in North America in the past 20 years. The disturbance regime in tundra may not have changed. Tundra has a 3-6-fold higher winter albedo than boreal forest, but summer albedo and energy partitioning differ more strongly among ecosystems within either tundra or boreal forest than between these two biomes. This indicates a need to improve our understanding of vegetation dynamics within, as well as between, biomes. If regional surface warming were to continue, changes in albedo and energy absorption would likely act as a positive feedback to regional warming due to earlier melting of snow and, over the long term, the northward movement of treeline. Surface drying and a change in dominance from mosses to vascular plants would also enhance sensible heat flux and regional warming in tundra. In the boreal forest of western North America, deciduous forests have twice the albedo of conifer forests in both winter and summer, 50-80% higher evapotranspiration, and therefore only 30-50% of the sensible heat flux of conifers in summer. Therefore, a warming-induced increase in fire frequency that increased the proportion of deciduous forests in the landscape, would act as a negative feedback to regional warming. Changes in thermokarst and the aerial extent of wetlands, lakes, and ponds would alter high-latitude methane flux. There is currently a wide discrepancy among estimates of the size and direction of CO2 flux between high-latitude ecosystems and the atmosphere. These discrepancies relate more strongly to the approach and assumptions for extrapolation than to inconsistencies in the underlying data. Inverse modelling from atmospheric CO2 concentrations suggests that high latitudes are neutral or net sinks for atmospheric CO2, whereas field measurements suggest that high latitudes are neutral or a net CO2 source. Both approaches rely on assumptions that are difficult to verify. The most parsimonious explanation of the available data is that drying in tundra and disturbance in boreal forest enhance CO2 efflux. Nevertheless, many areas of both tundra and boreal forests remain net sinks due to regional variation in climate and local variation in topographically determined soil moisture. Improved understanding of the role of high-latitude ecosystems in the climate system requires a concerted research effort that focuses on geographical variation in the processes controlling land-atmosphere exchange, species composition, and ecosystem structure. Future studies must be conducted over a long enough time-period to detect and quantify ecosystem feedbacks. C1 Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. Univ Alaska, US Geol Survey, Alaska Cooperat Fish & Wildlife Res Unit, Fairbanks, AK 99775 USA. Univ Calif Berkeley, Dept Atmospher Sci, Berkeley, CA 94720 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. Univ Minnesota, Dept Ecol Evolut & Behav, St Paul, MN 55108 USA. McGill Univ, Dept Geog, Montreal, PQ H3A 2K6, Canada. Univ Bern, Inst Geog, CH-3012 Bern, Switzerland. ERIM Int Inc, Ann Arbor, MI 48113 USA. Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA. NE Sci Stn, Cherskii 678830, Sakha Yakutia, Russia. Univ Montana, Sch Forestry, Missoula, MT 59812 USA. RP Chapin, FS (reprint author), Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. RI Pielke, Roger/A-5015-2009; Baldocchi, Dennis/A-1625-2009; Eugster, Werner/E-5116-2010; OI Baldocchi, Dennis/0000-0003-3496-4919; Eugster, Werner/0000-0001-6067-0741; Chapin III, F Stuart/0000-0002-2558-9910; Hobbie, Sarah/0000-0001-5159-031X NR 61 TC 307 Z9 317 U1 18 U2 207 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 DEC PY 2000 VL 6 SU 1 BP 211 EP 223 DI 10.1046/j.1365-2486.2000.06022.x PG 13 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 399FA UT WOS:000166799900015 ER PT J AU Hu, XS Shin, K Rafailovich, M Sokolov, J Stein, R Chan, Y Williams, K Wu, WL Kolb, R AF Hu, XS Shin, K Rafailovich, M Sokolov, J Stein, R Chan, Y Williams, K Wu, WL Kolb, R TI Anomalies in the optical index of refraction of spun cast polystyrene thin films SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 3rd Annual Garcia Materials Science Research and Engineering Center Workshop (MRSEC) CY FEB 16-17, 2000 CL GARCIA, SOUTH KOREA SP Korean Atom Energy Res Inst, Korean Adv Inst Sci & Technol, Natl Sci Fdn, Mat Sci Res & Engn Ctr ID SOLVENT AB We used x-ray reflectivity in combination with optical ellipsometry to measure the optical index of refraction, n, in thin spun cast polystyrene films. We have found that n is independent of the molecular weight, but is a sharp Function of the film thickness for films less than 100 nm. in all cases the deviation from the bulk, Deltan, is negative and varies linearly with wavelength in the visible region. The magnitude of Deltan, was found to be as large as 0.25 for films 7 nm thick. The bulk index of refraction was recovered in all films after annealing for 2 h above T-g at 160 degreesC. X-ray reflectivity measurements of the scattering critical angle show minimal density deviations from the bulk (less than 0.5%) between the annealed and unannealed films. Consequently the large molecular-weight-independent value of Deltan is interpreted as being due to a radially symmetric segmental orientation induced by the spinning process. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Univ Massachusetts, Dept Chem & Engn, Amherst, MA 01003 USA. Wheatley High Sch, Old Westbury, NY 11568 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Veeco Instruments Inc, Plainview, NY 11803 USA. Exxon Res & Engn Co, Annandale, NJ 08801 USA. RP Hu, XS (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RI Shin, Kwanwoo /C-4979-2012; OI Shin, Kwanwoo/0000-0002-7563-8581 NR 11 TC 13 Z9 14 U1 0 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0954-0083 J9 HIGH PERFORM POLYM JI High Perform. Polym. PD DEC PY 2000 VL 12 IS 4 BP 621 EP 629 DI 10.1088/0954-0083/12/4/318 PG 9 WC Polymer Science SC Polymer Science GA 387MA UT WOS:000166125300019 ER PT J AU Penzes, WB Allen, RA Cresswell, MW Linholm, LW Teague, EC AF Penzes, WB Allen, RA Cresswell, MW Linholm, LW Teague, EC TI A new method to measure the distance between graduation lines on graduated scales SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE bridge resistance; electrical calibration; electrical test structure; laser interferometry; length; line scale; measurement uncertainty; optical calibration; potentiometer; scale graduations; stage micrometer; voltage-dividing AB Line scales are used throughout industry for a variety of applications. The most common is the stage micrometer, a small, graduated glass scale for the calibration of optical instruments such as microscopes. However, stage micrometers are generally not calibrated, except for critical applications, due to the time and cost of optical calibration techniques. A method for calibrating line scales is presented which uses electrical test structure metrology, A description of the technique as well as examples of results from this technique are presented. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Penzes, WB (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 2000 VL 49 IS 6 BP 1285 EP 1288 DI 10.1109/19.893272 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 394MP UT WOS:000166528100023 ER PT J AU Kitching, J Knappe, S Vukicevic, N Hollberg, L Wynands, R Weidmann, W AF Kitching, J Knappe, S Vukicevic, N Hollberg, L Wynands, R Weidmann, W TI A microwave frequency reference based on VCSEL-driven dark line resonances in Cs vapor SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE atomic clock; frequency reference; VCSEL; vertical-cavity; surface-emitting laser ID RUBIDIUM ATOMIC CLOCK; LASER PHASE NOISE; SEMICONDUCTOR-LASER; RAMAN TRANSITION; RESOLUTION SPECTROSCOPY; POPULATION-INVERSION; AMPLITUDE NOISE; RAMSEY FRINGES; EMISSION; CESIUM AB Dark line resonances, narrowed with a buffer gas to less than 100 Hz width, are observed in a Cs vapor cell using a directly modulated vertical-cavity surface-emitting laser (VCSEL). An external oscillator locked to one of these resonances exhibits a short-term stability of sigma (y)(tau) = 9.3 x 10-12/root tau, Which drops to 1.6 x 10(-12) at 100 s, A physics package for a frequency-reference based on this design could be compact, low-power, and simple to implement. C1 Univ Colorado, JILA, Boulder, CO 80302 USA. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Univ Bonn, Inst Angew Phys, D-53115 Bonn, Germany. RP Kitching, J (reprint author), Univ Colorado, JILA, Boulder, CO 80302 USA. NR 31 TC 107 Z9 111 U1 5 U2 23 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 2000 VL 49 IS 6 BP 1313 EP 1317 DI 10.1109/19.893276 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 394MP UT WOS:000166528100027 ER PT J AU Arz, U Williams, DF Walker, DK Grabinski, H AF Arz, U Williams, DF Walker, DK Grabinski, H TI Asymmetric coupled CMOS lines - An experimental study SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT IEEE MTT-S International Microwave Symposium (IMS2000) CY JUN 11-16, 2000 CL BOSTON, MASSACHUSETTS SP IEEE, MTT S DE coupled mode analysis; integrated circuit interconnections; measurement; multiconductor transmission line; parameter estimation; silicon ID S-PARAMETER MEASUREMENTS; TRANSMISSION-LINES AB This paper investigates the properties of asymmetric coupled lines built in a 0.25-mum CMOS technology over the frequency range of 50 MHz to 26.5 GHz. We show that the frequency-dependent line parameters extracted from calibrated four-port scattering-parameter measurements agree well with numerical predictions. We also demonstrate by measurement and calculation that the two fundamental modes of the coupled-line system share significant cross power. To our knowledge, this is the first complete experimental characterization of asymmetric coupled lines on silicon ever reported. C1 Univ Hannover, Informat Technol Lab, D-30167 Hannover, Germany. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Arz, U (reprint author), Univ Hannover, Informat Technol Lab, D-30167 Hannover, Germany. NR 18 TC 12 Z9 13 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 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 2000 VL 48 IS 12 BP 2409 EP 2414 DI 10.1109/22.898991 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA 397RN UT WOS:000166709500027 ER PT J AU Love, DP Toomb, DS Wilkinson, DC Parkinson, JB AF Love, DP Toomb, DS Wilkinson, DC Parkinson, JB TI Penetrating electron fluctuations associated with GEO spacecraft anomalies SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE author; please supply index terms; E-mail keywords@ieee.org for info ID RELATIVISTIC ELECTRONS; MAGNETOSPHERE; SATELLITE AB Space weather is a known factor in spacecraft anomalies. Solar minimum carries with it an enhanced electron content, Electrons with sufficient energy to penetrate a spacecraft structure pose a hazard. They can accumulate in interior dielectrics creating an electric potential sufficient to cause a spontaneous breakdown. The resulting electrostatic discharge has been a cause of operational anomalies. The physical process by which the geosynchronous earth orbit (GEO) environment is populated by high-energy electrons is not fully understood. However, the solar-cycle, seasonal, and solar-rotational patterns observed are well documented. This paper reviews temporal fluence patterns and shows how some notorious satellite failures relate to them. It should be noted, however, the temporal response of a discharge is not necessarily at the instantaneous peak flux, but related to total local fluence and hom the dielectric responds to stress. Knowledge of the changes in mechanical and electrical properties of dielectrics in the space environment and a growing understanding of the variability of the electron population at GEO will enable the resolution of anomalies and facilitate their prevention. C1 GenCorp Aerojet, Azusa, CA 91702 USA. SAVEinc, Claremont, CA 91711 USA. NOAA, EEG2, Boulder, CO 80303 USA. RP Love, DP (reprint author), GenCorp Aerojet, Azusa, CA 91702 USA. NR 21 TC 16 Z9 22 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 2075 EP 2084 DI 10.1109/27.902234 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400028 ER PT J AU Han, JH Pratt, M Regli, WC AF Han, JH Pratt, M Regli, WC TI Manufacturing feature recognition from solid models: A status report SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article DE computer-aided design (CAD); manufacturing feature recognition; process planning; solid modeling ID INTERACTING MACHINING FEATURES; CONVEX DECOMPOSITION; VOLUME DECOMPOSITION; BAYESIAN-APPROACH; FORM FEATURES; EXTRACTION AB The field of solid modeling has developed a variety of techniques for unambiguous representations of three-dimensional objects. Feature recognition is a sub-discipline of solid modeling that focuses on the design and implementation of algorithms for detecting manufacturing information from solid models produced by computer-aided design (CAD) systems. Examples of this manufacturing information include features such as holes, slots, pockets and other shapes that can be created on modern computer numerically controlled machining systems. Automated feature recognition has been an active research area in solid modeling for many years and is considered to be a critical component for integration of CAD and computer-aided manufacturing. This paper gives an overview of the state-of-the-art in feature recognition research. Rather than giving an exhaustive survey, we focus on the three of the major algorithmic approaches for feature recognition: graph-based algorithms, volumetric decomposition techniques, and hint-based geometric reasoning. For each approach, we present a detailed description of the algorithms being employed along with some assessments of the technology. We conclude by outlining important open research and development issues. C1 Sungkyunkwan Univ, Sch Elect & Comp Engn, Comp Graph Lab, Suwon 440746, South Korea. Natl Inst Stand & Technol, Mfg Syst Integrat Div, Gaithersburg, MD 20899 USA. Drexel Univ, Dept Math & Comp Sci, Geometr & Intelligent Comp Lab, Philadelphia, PA 19104 USA. RP Sungkyunkwan Univ, Sch Elect & Comp Engn, Comp Graph Lab, Suwon 440746, South Korea. EM han@ece.skku.ac.kr; pratt@cme.nist.gov; regli@drexel.edu NR 95 TC 97 Z9 111 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD DEC PY 2000 VL 16 IS 6 BP 782 EP 796 DI 10.1109/70.897789 PG 15 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA 397GH UT WOS:000166684600015 ER PT J AU Benford, DJ Allen, CA Chervenak, JA Freund, MM Kutyrev, AS Moseley, SH Shafer, RA Staguhn, JG Grossman, EN Hilton, GC Irwin, KD Martinis, JM Nam, SW Reintsema, OD AF Benford, DJ Allen, CA Chervenak, JA Freund, MM Kutyrev, AS Moseley, SH Shafer, RA Staguhn, JG Grossman, EN Hilton, GC Irwin, KD Martinis, JM Nam, SW Reintsema, OD TI Multiplexed readout of superconducting bolometers SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE bolometers; SQUIDs; multiplexing; transition edge sensors; far infrared; submillimeter ID ARRAYS; DESIGN AB Studies of emission in the far-infrared and submillimeter from astrophysical sources require large arrays of detectors containing hundreds to thousands of elements. A multiplexed readout is necessary for practical implementation of such arrays, and can be developed using SQUIDs, such that, e.g., a 32x32 array of bolometers can be read out using similar to 100 wires rather than the >2000 needed with a brute force expansion of existing arrays. These bolometer arrays are made by micromachining techniques, using superconducting transition, edge sensors as the thermistors. We describe the development of this multiplexed superconducting bolometer array architecture as a step toward bringing about the first astronomically useful arrays of this design. This technology will be used in the SAFIRE instrument on SOFIA, and is a candidate for a wide variety of other spectroscopic and photometric instruments. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NIST, Boulder, CO 80305 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Moseley, Harvey/D-5069-2012 OI Benford, Dominic/0000-0002-9884-4206; NR 14 TC 27 Z9 27 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD DEC PY 2000 VL 21 IS 12 BP 1909 EP 1916 DI 10.1023/A:1006752416612 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 379QN UT WOS:000165654100001 ER PT J AU Hryniewicz, P Szeri, AZ Jahanmir, S AF Hryniewicz, P Szeri, AZ Jahanmir, S TI Coolant flow in surface grinding with non-porous wheels SO INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES LA English DT Article DE grinding fluid; coolant rejection; drop formation ID RAYLEIGH-TAYLOR INSTABILITY; FLUID-FLOW; ZONE AB A parameter that is often used in the assessment of cooling efficiency in grinding is the amount of fluid that flows through the grinding zone. This paper shows that when grinding with wheels possessing no bulk porosity, only a portion of the now through the grinding zone is effective. Even at the highest wheel speeds employed, it is observed that ample fluid travels on the wheel surface and is re-directed into the grinding zone - a phenomenon that may adversely affect cooling and wheel cleaning. Therefore fluid rejection off the wheel is important. A theoretical model for fluid rejection is proposed, that describes the drop formation process, presents the operating instabilities, identifies characteristic time and length scales, and predicts the amount of rejected fluid. Although the surface roughness of the wheel is important in quantifying coolant Row rates, a smooth wheel is employed in this work to study first order effects. Preliminary experimental results obtained for a rough grinding wheel are in conformance with those for a smooth wheel. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Hryniewicz, P (reprint author), Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA. NR 15 TC 13 Z9 13 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7403 J9 INT J MECH SCI JI Int. J. Mech. Sci. PD DEC PY 2000 VL 42 IS 12 BP 2347 EP 2367 DI 10.1016/S0020-7403(99)00084-3 PG 21 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 340JW UT WOS:000088530200006 ER PT J AU Naugolnykh, KA Shang, EC Wang, YY AF Naugolnykh, KA Shang, EC Wang, YY TI Acoustic sensing of temperature changes in a strongly range-dependent ocean SO INVERSE PROBLEMS LA English DT Article AB The inverse problem of inferring information about the intervening ocean can be solved by a comparison of the computed arrival times and measured patterns of arrivals. This approach is Very effective if in the process of sound signal propagation the modal energy exchange is negligible, the mode propagation can be considered as adiabatic and each mode has a clear amplitude and phase. In the range-dependent ocean, drastic 'repopulation' of the modes takes place due to intense energy exchange. The energy distribution between modes changes, and the order of modal arrivals varies. For the strong-mode-coupling case a fixed mode travel time does not have a monotonic relationship with the temperature variation. To obtain monotonic dependence of the sound signal parameters upon the environmental characteristics, specific approaches to the forward problem solution have to be used; two of them-the collective arrival time and the cumulative sum-are considered in this paper. They consists of defining trends in the signal arrival pattern caused by the temperature changes, and computing average parameters of the arriving signal ensemble. C1 Univ Colorado, NOAA, CIRES, Environm Technol Lab 325, Boulder, CO 80303 USA. RP Naugolnykh, KA (reprint author), Univ Colorado, NOAA, CIRES, Environm Technol Lab 325, Broadway, Boulder, CO 80303 USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD DEC PY 2000 VL 16 IS 6 BP 1667 EP 1678 DI 10.1088/0266-5611/16/6/305 PG 12 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 387VN UT WOS:000166142700006 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 (vol 33, 1046, 2000) SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Correction C1 SRI, CAT, Adv Photon Source, Argonne Natl Lab, Argonne, IL USA. Natl Inst Stand & Technol, Div Phys & Chem Properties, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Haeffner, DR (reprint author), SRI, CAT, Adv Photon Source, Argonne Natl Lab, Argonne, IL USA. RI Welberry, Thomas/H-7847-2014 OI Welberry, Thomas/0000-0002-6906-9191 NR 2 TC 0 Z9 0 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 2000 VL 33 BP 1449 EP 1048 DI 10.1107/S0021889800013911 PN 6 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 376ZV UT WOS:000165488200024 ER PT J AU Nystuen, JA McPhaden, MJ Freitag, HP AF Nystuen, JA McPhaden, MJ Freitag, HP TI Surface measurements of precipitation from an ocean mooring: The underwater acoustic log from the South China Sea SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RAINFALL; SOUND; CLASSIFICATION; WINDS; NOISE AB Surface measurements of precipitation in oceanic environments have proven especially difficult to obtain because traditional technologies such as tipping-bucket rain gauges are unsuitable for deployment from oceanic platforms such as ships and moorings. Recently, the Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration has modified a collection gauge, the R. M. Young Company rain gauge, for long-term deployment on deep ocean moorings. This instrumentation package was deployed during part of the South China Sea Monsoon Experiment. Also deployed on the same mooring were two acoustic rain gauges (ARGs) that monitor precipitation through the interpretation of the high-frequency, from 500 to 50 000 Hz, underwater sound field. The mooring was located at 20 degrees 22.2'N, 116 degrees 31.2'E and was in place from 7 April-5 June 1998. Unfortunately, pirates stole the surface instrumentation on 6 May 1998, limiting data from the R. M. Young rain gauge to satellite transmissions prior to the attack. The ARGs survived the attack and reported data throughout the deployment. The acoustic data are interpreted to provide quantification of wind speed; detection, classification, and quantification of rainfall; and the detection and quantification of near-surface bubble layers. Percentage-of-time-raining data from the two rainfall measurements are in excellent agreement. Based on comparison with the R. M. Young rain gauge data, modified acoustic rainfall algorithms are proposed. The acoustic detection of several instances of high near-surface bubble injections during extremely heavy rainfall is described. C1 Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Nystuen, JA (reprint author), Univ Washington, Appl Phys Lab, 1013 NE 40th St, Seattle, WA 98105 USA. EM nystuen@apl.washington.edu RI McPhaden, Michael/D-9799-2016 NR 28 TC 13 Z9 14 U1 1 U2 6 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 DEC PY 2000 VL 39 IS 12 BP 2182 EP 2197 DI 10.1175/1520-0450(2001)040<2182:SMOPFA>2.0.CO;2 PN 1-2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386BJ UT WOS:000166040000015 ER PT J AU Gage, KS Williams, CR Johnston, PE Ecklund, WL Cifelli, R Tokay, A Carter, DA AF Gage, KS Williams, CR Johnston, PE Ecklund, WL Cifelli, R Tokay, A Carter, DA TI Doppler radar profilers as calibration tools for scanning radars SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MESOSCALE CONVECTIVE SYSTEMS; RAINDROP SIZE DISTRIBUTIONS; WIND PROFILER; DROP-SIZE; VERTICAL MOTION; CLOUD SYSTEMS; PRECIPITATION; UHF; STRATIFORM AB The National Oceanic and Atmospheric Administration's Aeronomy Laboratory has modified a standard 915-MHz profiler for use as a precipitation profiler in support of Tropical Rainfall Measuring Mission ground validation field campaigns. This profiler was modified to look vertically with a fixed dish antenna. It was operated during the Texas and Florida Underflights Experiment (TEFLUN) A in south Texas in April-May 1998 and during TEFLUN B in central Florida in August-September 1998. Collocated with the profiler was a Distromet, Inc., RD-69 Joss-Waldvogel disdrometer in Texas and Florida and a two-dimensional video disdrometer in Florida. The disdrometers are used to calibrate the profiler at the lowest range gates. At higher altitudes, the calibrated profiler reflectivities are compared with observations made by scanning radars such as the Weather Surveillance Radar-1988 Doppler in Dickinson, Texas, and Melbourne, Florida, and the S-band Doppler dual-polarization radar in Florida. The authors conclude that it is possible to use profilers as transfer standards to calibrate and to validate the reflectivities measured by the scanning radars. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Gage, KS (reprint author), NOAA, Aeron Lab, MS R-E-AL3,325 Broadway, Boulder, CO 80303 USA. EM kgage@al.noaa.gov RI Williams, Christopher/A-2723-2015; Johnston, Paul/E-1914-2016 OI Williams, Christopher/0000-0001-9394-8850; Johnston, Paul/0000-0002-4046-9351 NR 31 TC 33 Z9 33 U1 0 U2 2 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 DEC PY 2000 VL 39 IS 12 BP 2209 EP 2222 DI 10.1175/1520-0450(2001)040<2209:DRPACT>2.0.CO;2 PN 1-2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386BJ UT WOS:000166040000017 ER PT J AU Ignatov, A Stowe, L AF Ignatov, A Stowe, L TI Physical basis, premises, and self-consistency checks of aerosol retrievals from TRMM VIRS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID OPTICAL-PROPERTIES; SATELLITE; VALIDATION; OCEANS; AVHRR; SEA; ALGORITHM; THICKNESS; ATLANTIC; DEPTH AB This paper outlines the processing stream for aerosol retrievals over oceans from the visible and infrared scanner [VIRS; a five-channel radiometer similar to the National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer (AVHRR)] aboard the Tropical Rainfall Measuring Mission (TRMM) satellite, launched in November 1997. Emphasis is on 1) the applying the previously developed AVHRR second-generation aerosol retrieval algorithm to VIRS data to derive an aerosol parameter, indicative of particle size; 2) removing the unwanted "thermal leak'' signal in the 1.61-mum channel; 3) giving examples of the first aerosol retrievals from space at this wavelength; and 4) assessing the accuracy of the retrievals with theoretical error analyses and empirical self- and interconsistency checks. Aerosol optical depths tau (A)(1) and tau (A)(2) are retrieved from reflected solar radiances in VIRS channels 1 and 2 centered at wavelengths lambda (1) = 0.63 and lambda (2) = 1.61 mum, using two independent lookup tables. When tau (A)(1) and tau (4)(2) exceed a certain threshold tau (A)(min) an effective Angstrom exponent alpha related to particle size is derived as alpha = -ln(tau (A)(1)/tau (A)(2))/ln(lambda (1)/lambda (2)). Channel 2 is contaminated by a thermal leak,originating from a secondary spectral response peak centred at similar to5.2 mum. If uncorrected, it leads to errors in tau (A)(2) of 100% or more. To minimize this error, nighttime VIRS "dark" radiances in channel 2 have been related empirically to radiances in channels 4 and 5 (10.8 and 12 mum, respectively), and view angle through regression analyses. The reflected component in channel-2 daytime measurements is estimated by subtracting the empirically derived thermal component from the total signal and is used in the retrieval of tau 24. Theoretical error analysis is used to identify the limitations of the VIRS retrieval algorithm, whereas actual retrievals are preliminarily evaluated using a set of specially developed empirical checks. The checks show, on average, a high degree of self- and interconsistency but also identify problems with the retrievals, the most noteworthy being trends in retrieved optical depths with viewing and illumination angles. These problems will be tackled in the next-generation aerosol retrieval algorithm. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Climate Res & Applicat Div, Off Res & Applicat, Washington, DC 20233 USA. RP Ignatov, A (reprint author), NOAA, WWBG, E-RA1,Rm 712,5200 Auth Rd, Camp Springs, MD 20746 USA. EM aignatov@nesdis.noaa.gov RI Ignatov, Alexander/F-5594-2010 OI Ignatov, Alexander/0000-0002-7463-5944 NR 37 TC 38 Z9 37 U1 1 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. PY 2000 VL 39 IS 12 BP 2259 EP 2277 DI 10.1175/1520-0450(2001)040<2259:PBPASC>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386BJ UT WOS:000166040000021 ER PT J AU Atlas, D Matrosov, SY Heymsfield, AJ Chou, MD Wolff, DB AF Atlas, D Matrosov, SY Heymsfield, AJ Chou, MD Wolff, DB TI Radar and radiation properties of ice clouds (vol 34, pg 2329, 1995) SO JOURNAL OF APPLIED METEOROLOGY LA English DT Correction C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, OAR, ETL, Boulder, CO USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Appl Res Corp, Landover, MD 20785 USA. RP Atlas, D (reprint author), NASA, Goddard Space Flight Ctr, Code 912-1, Greenbelt, MD 20771 USA. EM datlas@radar.gsfc.nasa.gov RI Heymsfield, Andrew/E-7340-2011 NR 2 TC 0 Z9 0 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. PY 2000 VL 39 IS 12 BP 2495 EP 2495 DI 10.1175/1520-0450(2000)039<2495:C>2.0.CO;2 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386BJ UT WOS:000166040000038 ER PT J AU Klein, R O'Hare, PAG Jacob, I AF Klein, R O'Hare, PAG Jacob, I TI Enthalpies of formation of alloys in the pseudobinary LaAlxNi5-x system SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE alloy; aluminum; formation enthalpy; lanthanum; nickel ID STANDARD MOLAR ENTHALPIES; ZR(ALXFE1-X)2 SYSTEM; HYDROGEN ABSORPTION; LANI5-XALX AB The pseudobinary system LaAlxNi5-x has a composition limit at x approximate to 1.4. The standard molar enthalpies of formation Delta H-f(m)0(298.15 K) for this system were determined by solution calorimetry in HCl (c = 6 mol.dm(-3)) to be: -(129.4 +/- 6.5) kJ.mol(-1) for x = 0; -(159.5 +/- 15.9) kJ.mol(-1) for x = 0.25; -(185.9 +/- 6.7) kJ.mol(-1) for x = 0.375; -(191.8 +/- 12.4) kJ.mol(-1) for x = 0.5; and -(283.2 +/- 8.9) kJ.mol(-1) for x = 1. Uncertainties correspond to twice the standard deviation of the mean and include contributions from the scatter of the calorimetric results and electrical calibrations, as well as analytical uncertainties. Previous results for Delta H-f(m)0(LaNi5) fall into two groups; they are compared with the present determination. The plot of Delta H-f(m)0 against x is linear within experimental error. (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Ben Gurion Univ Negev, Dept Nucl Engn, IL-84105 Beer Sheva, Israel. RP Klein, R (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 27 TC 2 Z9 2 U1 0 U2 1 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 DEC PY 2000 VL 32 IS 12 BP 1607 EP 1615 DI 10.1006/jcht.2000.0701 PG 9 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 402PB UT WOS:000166996400003 ER PT J AU Nadal, ME Thompson, EA AF Nadal, ME Thompson, EA TI New primary standard for specular gloss measurements SO JOURNAL OF COATINGS TECHNOLOGY LA English DT Article AB A new primary specular gloss standard has been developed at the National Institute of Standards and Technology to overcome the disadvantages of black glass. This new standard is a high-purity BaK50 glass with good mechanical durability and homogeneity. In addition, the index of refraction n(D) = 1.5677 is close to the value specified for the theoretical standard, and the dispersion characteristics are similar to black glass. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Nadal, ME (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 11 TC 27 Z9 27 U1 0 U2 2 PU FEDERATION SOC COATING TECH PI BLUE BELL PA 492 NORRISTOWN ROAD, BLUE BELL, PA 19422 USA SN 0361-8773 J9 J COATING TECHNOL JI J. Coat. Technol. PD DEC PY 2000 VL 72 IS 911 BP 61 EP 66 DI 10.1007/BF02720526 PG 6 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA 382WD UT WOS:000165849600009 ER PT J AU Bailey, SM Woods, TN Barth, CA Solomon, SC Canfield, LR Korde, R AF Bailey, SM Woods, TN Barth, CA Solomon, SC Canfield, LR Korde, R TI Measurements of the solar soft X-ray irradiance by the Student Nitric Oxide Explorer: First analysis and underflight calibrations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EUV FLUX MODEL; EXTREME-ULTRAVIOLET; SILICON PHOTODIODES; PHOTOELECTRON FLUX; CELIAS/SEM; STABILITY; REGION; SOHO AB Beginning on March 11, 1998, the Student Nitric Oxide Explorer (SNOE) satellite has made daily observations of the solar soft X-ray irradiance. These measurements are carried out by a multichannel photometer system. The spectral range between 2 and 20 nm is covered by three channels with bandpasses of 2 - 7 nm, 6 - 19 nm, and 17 - 20 nm respectively. Absolute sensitivities were measured preflight using the Synchrotron Ultraviolet Radiation Facility of the National Institute of Standards and Technology. The results of the first 1.5 years of SNOE solar measurements are presented. During this time period the F-10.7 solar index varied between 80 and 250 x 10(-22) W m(-2) Hz(-1) and the 81-day average of the F-10.7 solar index varied between 100 and 175 x 10(-22) W m(-2) Hz(-1). The solar irradiances in the 2 - 7 nm interval varied between 0.3 and 2.5 mW m(-2), while the irradiances in the 6 - 19 and 17 20 nm intervals varied between 0.5 and 3.5 and 1.0 and 3.5 mW m(-2), respectively. The measured irradiances are correlated with the F10.7 solar index with a correlation coefficient of similar to0.9 in all three bandpasses. For the levels of activity observed so far the SNOE measurements are typically a factor of 4.0 larger than the irradiances predicted by the Hinteregger et al. [1981] empirical model thereafter the Hinteregger model). This fact and a long-term trend in the ratio of SNOE measurements to Hinteregger model predictions show that the Hinteregger model underpredicts the long-term variability in the solar soft X-ray irradiance. It is shown that other empirical models provide a reasonable representation of the 27-day variability but also underpredict the magnitude and long term variability. A sounding rocket measurement made on November 2, 1998, by the Thermosphere Ionosphere Mesosphere Energetics and Dynamics Solar EUV Experiment prototype instrument using the same technique measured the solar irradiance in similar wavelength bands and produced results that are in good agreement with the SNOE measurements. C1 Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Int Radiat Detectors, Torrance, CA 90505 USA. RP Bailey, SM (reprint author), Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RI Solomon, Stanley/J-4847-2012 OI Solomon, Stanley/0000-0002-5291-3034 NR 41 TC 69 Z9 70 U1 0 U2 1 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 DEC 1 PY 2000 VL 105 IS A12 BP 27179 EP 27193 DI 10.1029/2000JA000188 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 386BL UT WOS:000166040200010 ER PT J AU Coffey, HE AF Coffey, HE TI Geomagnetic and solar data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article C1 NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80303 USA. RP Coffey, HE (reprint author), NOAA, World Data Ctr Solar Terr Phys A, Boulder, CO 80303 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 2000 VL 105 IS A12 BP 27845 EP 27849 DI 10.1029/2000JA900149 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 386BL UT WOS:000166040200064 ER PT J AU Hogue, TS Sorooshian, S Gupta, H Holz, A Braatz, D AF Hogue, TS Sorooshian, S Gupta, H Holz, A Braatz, D TI A multistep automatic calibration scheme for river forecasting models SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID RAINFALL-RUNOFF MODELS; SHUFFLED COMPLEX EVOLUTION; GLOBAL OPTIMIZATION; PARAMETER OPTIMIZATION; ALGORITHMS AB Operational flood forecasting models vary in complexity. but nearly all have parameters for which values must be estimated. The traditional and widespread manual calibration approach requires considerable training and experience and is typically laborious and time consuming. Under the Advanced Hydrologic Prediction System modernization program. National Weather Service (NWS) hydrologists must produce rapid calibrations for roughly 4000 forecast points throughout the United States. The classical single-objective automatic calibration approach, although fast and objective, has not received widespread acceptance among operational hydrologists. In the work reported here. University of Arizona researchers and NWS personnel have collaborated to combine the strengths of the manual and automatic calibration strategies. The result is a multistep automatic calibration scheme (MACS) that emulates the progression of steps followed by NWS hydrologists during manual calibration and rapidly provides acceptable parameter estimates. The MACS approach was tested on six operational basins (drainage areas from 671 to 1302 km(2)) in the North Central River Forecast Center (NCRFC) area. The results were found to compare favorably with the NCRFC manual calibrations in terms of both visual inspection and statistical measures, such as daily root-mean-square error and percent bias by flow group. Further, implementation of the MACS procedure requires only about 3-4 person hours per basin, in contrast to the 15-20 person hours typically required using the manual approach. Based on this study, the NCRFC has opted to perform further testing of the MACS procedure at a large number of forecast points that constitute the Grand River (Michigan) forecast group. MACS is a time-saving, reliable approach that can provide calibrations that are of comparable quality to the NCRFC`s current methods. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. NOAA, Natl Weather Serv, N Cent River Forecast Ctr, Chanhassen, MN USA. RP Hogue, TS (reprint author), Univ Arizona, Dept Hydrol & Water Resources, Bldg 11,Room 122, Tucson, AZ 85721 USA. RI Gupta, Hoshin/D-1642-2010; sorooshian, soroosh/B-3753-2008 OI Gupta, Hoshin/0000-0001-9855-2839; sorooshian, soroosh/0000-0001-7774-5113 NR 37 TC 78 Z9 82 U1 0 U2 7 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 DEC PY 2000 VL 1 IS 6 BP 524 EP 542 DI 10.1175/1525-7541(2000)001<0524:AMACSF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 397NF UT WOS:000166701200004 ER PT J AU Lawrimore, JH Peterson, TC AF Lawrimore, JH Peterson, TC TI Pan evaporation trends in dry and humid regions of the United States SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID TEMPERATURE AB Decreasing pan evaporation trends in many regions of the world have been viewed as evidence of a decrease in the terrestrial evaporation component of the hydrologic cycle. However, some researchers suggest that the relationship between pan evaporation and terrestrial evaporation depends on the environment in which the measurements are recorded and that pan evaporation trends run counter to trends in terrestrial evaporation in some climates. To determine whether evidence of this kind of relationship exists in the observational record. pan evaporation trends were compared with precipitation trends in eight regions within the United States. To the extent that warm-season precipitation can be used as an indicator of surface evaporation, these results support the view that pan evaporation and actual evaporation can be inversely related. C1 NOAA, NESDIS, Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Lawrimore, JH (reprint author), NOAA, NESDIS, Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. NR 14 TC 89 Z9 96 U1 2 U2 10 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 DEC PY 2000 VL 1 IS 6 BP 543 EP 546 DI 10.1175/1525-7541(2000)001<0543:PETIDA>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 397NF UT WOS:000166701200005 ER PT J AU Pierce, DT Davies, AD Stroscio, JA Tulchinsky, DA Unguris, J Celotta, RJ AF Pierce, DT Davies, AD Stroscio, JA Tulchinsky, DA Unguris, J Celotta, RJ TI Non-collinear exchange coupling in Fe/Mn/Fe(001): insight from scanning tunneling microscopy SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE exchange coupling; magnetic multilayer; film growth; whiskers; STM; SEMPA; RHEED ID ENERGY-ELECTRON-DIFFRACTION; SANDWICH STRUCTURES; MAGNETIC MULTILAYERS; FE/CR MULTILAYERS; MN FILMS; GROWTH; FE(100); CR; IRON; SUPERLATTICES AB The film growth and morphology of epitaxial Mn films grown on Fe(001) single-crystal whiskers measured with scanning tunneling microscopy (STM) provides insight into the mechanism of interlayer exchange coupling in Fe/Mn/Fe(001) trilayers. The proximity model of Slonczewski for exchange coupling through an antiferromagnet predicts that the coupling angle between the ferromagnetic layers will oscillate around a mean value of 90 degrees with an amplitude that is very sensitive to the width of the thickness distribution of the spacer layer. We measure the thickness distribution with the STM and find that the coupling angle variation predicted by the proximity model is qualitatively consistent with the actual coupling angle variations in Fe/Mn/Fe(001)measured with scanning electron microscopy with polarization analysis (SEMPA). Going beyond the proximity model and allowing for a non-uniform magnetization of the thin Fe overlayer provides an improved explanation of the results. We contrast the behavior of Fe/Mn/Fe(001),where the proximity model appears applicable, to coupling through antiferro-magnetic Cr in Fe/Cr/Fe(001), where it is not, and discuss possible reasons for the difference. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Electron Phys Grp, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Electron Phys Grp, Bldg 220,Rm B-206,Mailstop 8412, Gaithersburg, MD 20899 USA. EM daniel.pierce@nist.gov RI Unguris, John/J-3989-2014 NR 36 TC 22 Z9 22 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD DEC PY 2000 VL 222 IS 1-2 BP 13 EP 27 DI 10.1016/S0304-8853(00)00551-5 PG 15 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 387HF UT WOS:000166116600003 ER PT J AU Chaung, TJ Lee, S AF Chaung, TJ Lee, S TI Elastic flexure of bilayered beams subject to strain differentials SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB The residual stresses present in a thin film and the curvature formed at its substrate during deposition have been a great concern to electrochemists and process engineers. Here a new hybrid analytical method is presented to reanalyze the flexural problem subjected to a strain differential in the general case. It was shown that the present solutions for ultrathin films agree with Stoney's equation. Moreover, single or dual neutral axes resulted, depending on materials and thickness ratios between the film and the substrate. Quantitative differences with others in the solutions of deformed curvature and residual stress are discussed in a representative case of GaAs top coat/Si substrate wafers. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 30043, Taiwan. RP Chaung, TJ (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 12 TC 13 Z9 15 U1 0 U2 0 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 DEC PY 2000 VL 15 IS 12 BP 2780 EP 2788 DI 10.1557/JMR.2000.0397 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 381CZ UT WOS:000165745900030 ER PT J AU Harris, CD Holder, AJ Eick, JD Chappelow, CC Stansbury, JW AF Harris, CD Holder, AJ Eick, JD Chappelow, CC Stansbury, JW TI Semiempirical and ab initio conformational analysis of 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane with application of GIAO-SCF methods to NMR spectrum interpretation SO JOURNAL OF MOLECULAR GRAPHICS & MODELLING LA English DT Article DE chemical shift; GIAO-SCF; spiroorthocarbonate; isotropic shielding; nuclear magnetic resonance; conformational population distribution ID SHIELDING TENSORS; CHEMICAL-SHIFTS AB The GIAO-SCF method for calculating isotropic nuclear magnetic shielding values has been utilized to explain certain features in the H-1-NMR spectrum of 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane. Population distributions of the low-energy conformers based on their ab initio energies were used to produce weighting factors for the individual calculated shielding values to calculate the weighted average of the shielding values for a complete set of conformers. The differences in H-1 chemical shifts between the hydrogens of the two methyl groups and between the axial and equatorial hydrogens in 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane were shown to be due to energy differences between the chair and boat orientations of the six-membered ring and contribution from a twist-boat conformation. Results suggest a hypothesis that intramolecular differences in chemical shift might be calculated to a greater degree of accuracy than chemical shifts calculated relative to a standard. (C) 2000 by Elsevier Science Inc. C1 Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. Univ Missouri, Sch Dent, Kansas City, KS USA. Midwest Res Inst, Kansas City, MO 64110 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Harris, CD (reprint author), Univ Missouri, Dept Chem, 5100 Rockhill Rd, Kansas City, MO 64110 USA. FU NIDCR NIH HHS [DE08450, DE09696] NR 12 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1093-3263 J9 J MOL GRAPH MODEL JI J. Mol. Graph. PD DEC PY 2000 VL 18 IS 6 BP 567 EP 580 DI 10.1016/S1093-3263(00)00039-5 PG 14 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Computer Science, Interdisciplinary Applications; Crystallography; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Computer Science; Crystallography; Mathematical & Computational Biology GA 387KX UT WOS:000166122700001 PM 11155313 ER PT J AU Lyons, ET DeLong, RL Gulland, FM Melin, SR Tolliver, SC Spraker, TR AF Lyons, ET DeLong, RL Gulland, FM Melin, SR Tolliver, SC Spraker, TR TI Comparative biology of Uncinaria spp. in the California sea lion (Zalophus californianus) and the northern fur seal (Callorhinus ursinus) in California SO JOURNAL OF PARASITOLOGY LA English DT Article AB Studies on several aspects of the life cycle of hookworms (Uncinaria spp.) in the California sea lion (Zalophus californianus) and northern fur seal (Callorhinus ursinus) were conducted on material collected on San Miguel Island (SMI), California and at The Marine Mammal Center, Sausalito, California in 1997, 1998, and 1999. Examination of Z. californianus intestines for adult hookworms and feces for eggs revealed that longevity of these parasites in pups is about 6-8 mo, and infections are probably not present in older sea lions. Parasitic third-stage larvae (L-3) were recovered from the ventral abdominal tissue of Z. californianus, suggesting transmammary transmission. Callorhinus ursinus pups had no hookworm eggs in their feces or adult worms (except for 1 probable contaminant) in their intestines in the fall and early winter, revealing that adult Uncinaria spp. are spontaneously lost at <3 mo of age of the pups. Sand samples from rookeries, used by both Z. californianus and C. ursinus, on SMI were negative for free-living, L-3 in summer months but positive in fall and winter months, indicating seasonality occurred. C1 Univ Kentucky, Gluck Equine Res Ctr, Dept Vet Sci, Lexington, KY 40546 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Golden Gate Natl Recreat Area, Marin Headlands, Marine Mammal Ctr, Sausalito, CA 94965 USA. Colorado State Univ, Coll Vet Med, Dept Pathol, Ft Collins, CO 80523 USA. RP Lyons, ET (reprint author), Univ Kentucky, Gluck Equine Res Ctr, Dept Vet Sci, Lexington, KY 40546 USA. NR 12 TC 21 Z9 21 U1 2 U2 5 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 DEC PY 2000 VL 86 IS 6 BP 1348 EP 1352 DI 10.1645/0022-3395(2000)086[1348:CBOUSI]2.0.CO;2 PG 5 WC Parasitology SC Parasitology GA 388MF UT WOS:000166184200029 PM 11191915 ER PT J AU Yu, ZJ McCreary, JP Kessler, WS Kelly, KA AF Yu, ZJ McCreary, JP Kessler, WS Kelly, KA TI Influence of equatorial dynamics on the Pacific North Equatorial Countercurrent SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CENTRAL TROPICAL PACIFIC; WIND STRESS; OCEAN; CIRCULATION; SENSITIVITY; TRANSPORT; CURRENTS; SYSTEM; MODEL AB The Pacific North Equatorial Countercurrent (NECC) is generally not well simulated in numerical models. In this study, the causes of this problem are investigated by comparing model solutions to observed NECC estimates. The ocean model is a general circulation model of intermediate complexity. Solutions are forced by climatological and interannual wind stresses, tau = (tau (x), tau (y)), from Florida State University and the European Centre for Medium-Range Weather Forecasts. Estimates of the observed NECC structure and transport are prepared from expendable bathythermograph data and from the ocean analysis product of NOAA/National Centers for Environmental Prediction. In solutions forced by climatological winds, the NECC develops a discontinuity in the central Pacific that is not present in the observations. The character of the error suggests that it arises from the near-equatorial (5 degreesS-5 degreesN) zonal wind stress, tau (s),being relatively too strong compared to the y derivative of the wind stress curl term, (curl tau)(y), associated with the intertropical convergence zone. This is confirmed in solutions forced by interannual winds, which exhibit a wide range of responses from being very similar to the observed NECC to being extremely poor, the latter occurring when near-equatorial tau (x) is relatively too strong. Results show further that the model NECC transport is determined mainly by the strength of (curl t) y, but that its structure depends on near-equatorial tau (x); thus, NECC physics involves equatorial as well as Sverdrup dynamics. Only when the two forcing features are properly prescribed do solutions develop a NECC with both realistic spatial structure and transport. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. RP Yu, ZJ (reprint author), Univ Hawaii, SOEST, IPRC, 2525 Correa Rd, Honolulu, HI 96822 USA. NR 22 TC 15 Z9 15 U1 0 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 DEC PY 2000 VL 30 IS 12 BP 3179 EP 3190 DI 10.1175/1520-0485(2000)030<3179:IOEDOT>2.0.CO;2 PG 12 WC Oceanography SC Oceanography GA 386AL UT WOS:000166037500010 ER PT J AU Schmid, C Siedler, G Zenk, W AF Schmid, C Siedler, G Zenk, W TI Dynamics of intermediate water circulation in the subtropical South Atlantic SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ANTARCTIC MODE WATER; BENGUELA CURRENT; VENTILATED THERMOCLINE; NORTH-ATLANTIC; BRAZIL CURRENT; OCEAN; TRANSPORT; VARIABILITY; DRIVEN; LAYER AB The circulation of the low-salinity Antarctic Intermediate Water in the South Atlantic and the associated dynamical processes are studied, using recent and historical hydrographic profiles, Lagrangian and Eulerian current measurements as well as wind stress observations. The circulation pattern inferred for the Antarctic Intermediate Water supports the hypothesis of an anticyclonic basinwide recirculation of the intermediate water in the subtropics. The eastward current of the intermediate anticyclone is fed mainly by water recirculated in the Brazil Current and by the Malvinas Current. An additional source region is the Polar Frontal zone of the South Atlantic. The transport in the meandering eastward current ranges from 6 to 26 Sv (Sv = 10(6) m(3) s(-1)). The transport of the comparably uniform westward flow of the gyre varies between 10 and 30 Sv. Both transports vary with longitude. At the western boundary near 28 degreesS, in the Santos Bifurcation, the westward current splits into two branches. About three-quarters of the 19 Sv at 40 degreesW go south as an intermediate western boundary current. The remaining quarter flows northward along the western boundary. Simulations with a simple model of the ventilated thermocline reveal that the wind-driven subtropical gyre has a vertical extent of over 1200 m. The transports derived from the simulations suggest that about 90% of the transport in the westward branch of the intermediate gyre and about 50% of the transport in the eastward branch can be attributed to the wind-driven circulation. The structure of the simulated gyre deviates from observations to some extent. The discrepancies between the simulations and the observations are most likely caused by the interoceanic exchange south of Africa, the dynamics of the boundary currents, the nonlinearity, and the seasonal variability of the wind field. A simulation with an inflow/outflow condition for the eastern boundary reduces the transport deviations in the eastward current to about 20%. The results support the hypothesis that the wind field is of major importance for the subtropical circulation of Antarctic Intermediate Water followed by the interoceanic exchange. The simulations suggest that the westward transport in the subtropical gyre undergoes seasonal variations. The transports and the structure of the intermediate subtropical gyre from the Parallel Ocean Climate Model (Semtner-Chervin model) agree better with observations. C1 Univ Kiel, Inst Meereskunde, D-2300 Kiel, Germany. RP Schmid, C (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, PHOD, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Schmid, Claudia/D-5875-2013 OI Schmid, Claudia/0000-0003-2132-4736 NR 60 TC 37 Z9 37 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD DEC PY 2000 VL 30 IS 12 BP 3191 EP 3211 DI 10.1175/1520-0485(2000)030<3191:DOIWCI>2.0.CO;2 PG 21 WC Oceanography SC Oceanography GA 386AL UT WOS:000166037500011 ER PT J AU Adams, NG Lesoing, M Trainer, VL AF Adams, NG Lesoing, M Trainer, VL TI Environmental conditions associated with domoic acid in razor clams on the Washington coast SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE Pseudo-nitzschia; domoic acid; razor clams; upwelling ID DIATOM PSEUDONITZSCHIA-AUSTRALIS; PRINCE-EDWARD-ISLAND; US WEST-COAST; PSEUDO-NITZSCHIA; SHELLFISH; IDENTIFICATION; CALIFORNIA; RECEPTOR; CANADA; WATERS AB In October 1998, record levels of the neurotoxin domoic acid (DA) were detected in razor clams (Siliqua patula, Dixon) resulting in the closure of shellfish harvesting areas along the Washington coast. This toxin was detected in seawater samples collected at Kalaloch Beach and Second Beach on the central Washington coast using a receptor binding assay and liquid chromatography tandem mass spectroscopy. Domoic acid levels ranging from 0-2700 ng/L were measured in seawater samples containing from 70-100% Pseudo-nitzschia pseudodelicatissima (Hasle) Hasle at concentrations of 1.0-15 x 10(6) cells/L, resulting in maximum levels of cellular toxin of approximately 500 fg/cell. A cultured isolate of this species collected from Kalaloch Beach also produced DA, as determined by the receptor binding assay, during late exponential and stationary stages of growth. The toxic P. pseudodelicatissima bloom in the late summer and autumn of 1998 occurred 2-3 weeks after strong coastal upwelling during a period of anomalously low rainfall, typical in post-el Nino years. Higher toxin levels in seawater at Kalaloch Beach compared to Second Beach were attributed to the periodic nature of upwelling at Kalaloch Bench, demonstrated by a 175-fold increase in nitrate in seawater coincident with a 5 OC decrease in sea sui face temperature on September 1. The upwelling event in September was followed by wind relaxation and reversal at the end of that month, resulting in the transport of toxic cells toward the coast where nutrients were already present to fuel the algal bloom. A pulse of nutrients, either from rainfall or upwelling, to coastal regions that have experienced several weeks of low nutrients, followed by wind relaxation or reversal events that transport cells to inshore regions, are suggested to be important factors in the initiation of the most toxic Pseudo-nitzschia species blooms on the Washington coast. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. Quileute Indian Tribe, Quileute Nat Resources, La Push, WA 98350 USA. RP Adams, NG (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 36 TC 52 Z9 52 U1 4 U2 21 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 2000 VL 19 IS 2 BP 1007 EP 1015 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 391WW UT WOS:000166380100044 ER PT J AU Drabarek, E Bartlett, JR Hanley, HJM Woolfrey, JL Muzny, CD Butler, BD AF Drabarek, E Bartlett, JR Hanley, HJM Woolfrey, JL Muzny, CD Butler, BD TI Shear-induced restructuring of colloidal silica gels SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Workshop on Glasses, Ceramics, Hybrids, and Nanocomposites from Gels CY SEP 19-24, 1999 CL YOKOHAMA, JAPAN DE silica; gel structure; shear-induced restructuring; gelation mechanism AB Continuous oscillatory experiments were used to investigate the viscoelastic properties and structural evolution of silica gels obtained from unsheared and presheared sols, at pH 8. The processes controlling structural evolution before, at and after the gel point are discussed. Although the viscoelastic properties of the aged gels are comparable (implying similar structures on length scales of several microns), their chemical properties and microstructures (<1 mum) are significantly different. This is directly related to the different aggregate structures formed in the unsheared and presheared systems (50 and 700 nm, respectively) and the associated concentration of surface hydroxyls available for cross-linking and formation of stable siloxane bonds. C1 Australian Nucl Sci & Technol Org, Div Mat, Menai, NSW 2234, Australia. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Bartlett, JR (reprint author), Australian Nucl Sci & Technol Org, Div Mat, Private Mail Bag 1, Menai, NSW 2234, Australia. NR 7 TC 3 Z9 3 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PD DEC PY 2000 VL 19 IS 1-3 BP 279 EP 283 DI 10.1023/A:1008765111690 PG 5 WC Materials Science, Ceramics SC Materials Science GA 394VX UT WOS:000166544900048 ER PT J AU Ogi, H Heyliger, P Ledbetter, H Kim, S AF Ogi, H Heyliger, P Ledbetter, H Kim, S TI Mode-selective resonance ultrasound spectroscopy of a layered parallelepiped SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ELECTROMAGNETIC ACOUSTIC-RESONANCE; COMPOSITE AB The resonance frequencies of mechanical free vibration of a three-layer material calculated by a discrete-layer model and measured by acoustic-resonance methods were compared. The material was composed of an aluminum parallelepiped sandwiched by two stainless-steel parallelepipeds. The discrete-layer model developed here used linear Lagrange basis functions through the layered dimension and continuous global power-series basis functions in the plane perpendicular to the layer thickness. Using such a basis function for the layer-thickness direction allows discontinuity in the elastic properties across the interface between dissimilar layers. The resonance frequencies were measured using two methods: mode-selective electromagnetic acoustic resonance (EMAR) and resonance ultrasound spectroscopy (RUS). The measurements agreed with the calculations typically within 1%. The EMAR method allows the selective detection of vibrational modes possessing particular displacement patterns. This selectivity was supported by the model calculation. Thus, using the EMAR method makes mode identification clear and this is essential for developing and improving the model calculation of such a complicated structure. Internal friction was also measured by the two acoustic methods, which reveals the mechanical-contact effect on the internal-friction measurement in the RUS method. (C) 2000 Acoustical Society of America. [S0001-4966(00)04812-8]. C1 Osaka Univ, Grad Sch Engn Sci, Toyonaka, Osaka 5608531, Japan. Colorado State Univ, Dept Civil Engn, Ft Collins, CO 80523 USA. 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. NR 14 TC 13 Z9 13 U1 0 U2 4 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 DEC PY 2000 VL 108 IS 6 BP 2829 EP 2834 DI 10.1121/1.1323722 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 381TV UT WOS:000165780300015 ER PT J AU Roberts, AP Garboczi, EJ AF Roberts, AP Garboczi, EJ TI Elastic properties of model porous ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID EFFECTIVE STIFFNESS TENSOR; MINIMUM SOLID AREA; HETEROGENEOUS MATERIALS; COMPOSITE MEDIA; MODULI AB The finite-element method (FEM) is used to study the influence of porosity and pore shape on the elastic properties of model porous ceramics. Young's modulus of each model is practically independent of the solid Poisson's ratio. At a sufficiently high porosity, Poisson's ratio of the porous models converges to a fixed value independent of the solid Poisson's ratio. Young's modulus of the models is in good agreement with experimental data. We provide simple formulas that can be used to predict the elastic properties of ceramics and allow the accurate interpretation of empirical property-porosity relations in terms of pore shape and structure. C1 NIST, Bldg Mat Div, Gaithersburg, MD 20899 USA. Univ Queensland, Ctr Microscopy & Microanal, St Lucia, Qld 4072, Australia. RP Roberts, AP (reprint author), NIST, Bldg Mat Div, Gaithersburg, MD 20899 USA. RI Roberts, Anthony/A-3613-2011 OI Roberts, Anthony/0000-0001-5915-300X NR 40 TC 230 Z9 232 U1 5 U2 59 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 DEC PY 2000 VL 83 IS 12 BP 3041 EP 3048 PG 8 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300023 ER PT J AU Seabaugh, MM Messing, GL Vaudin, MD AF Seabaugh, MM Messing, GL Vaudin, MD TI Texture development and microstructure evolution in liquid-phase-sintered alpha-alumina ceramics prepared by templated grain growth SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PLATELIKE ABNORMAL GRAINS; BISMUTH TITANATE; ELECTRICAL-PROPERTIES; ORIENTATION; FABRICATION; AL2O3; MORPHOLOGY AB Texture development in alumina that contains calcia and silica and has been templated with platelet-shaped alpha -Al2O3 particles has been evaluated. The texture fraction is shown to be related directly to template growth. Texture quality is controlled by the template concentration, decreasing at template concentrations of >10%, as a result of template-template interactions during tape casting. Almost fully textured alumina has been obtained at template concentrations of greater than or equal to 20%. The growth of template grains is much more rapid in the radial direction and is shown to be inversely related to the thickness of the grain-boundary liquid. The activation energy for growth (376 KJ/mol) and the inverse relation with the grain-boundary thickness indicate that template growth in the radial direction is controlled by Al3+ diffusion. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Seabaugh, MM (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NR 47 TC 41 Z9 42 U1 1 U2 23 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 DEC PY 2000 VL 83 IS 12 BP 3109 EP 3116 PG 8 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300033 ER PT J AU Goldschmidt, RJ Wetzel, SJ Blair, WR Guttman, CM AF Goldschmidt, RJ Wetzel, SJ Blair, WR Guttman, CM TI Post-source decay in the analysis of polystyrene by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID COLLISION-INDUCED DISSOCIATION; LITHIUM-ATTACHMENT IONS; DESORPTION IONIZATION; SYNTHETIC-POLYMERS; POLYDISPERSE POLYMERS; POSTSOURCE DECAY; ORGANIC-SOLIDS; MALDI; DISTRIBUTIONS; PEPTIDES AB Various secondary series are observed in matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectra of polystyrene. The number and positions of the series depend on the choice of matrix and added cation. For a given treatment, series observed in linear mode are not necessarily observed in reflectron mode, and vice versa. Post-source decay analysis was used to determine that the secondary series arise at least in part from formation and decay of adducts of polystyrene with matrix species. There is some treatment-to-treatment variation, but adduct formation and decay were observed for all tested treatments. The multiplicity of secondary series makes it unclear whether post-source decay occurs for the main series (polystyrene + cation)(+) ions under the conditions normally used for polystyrene analysis. Such ions do undergo post-source decay at laser fluences greater than normally used. Although only polystyrene was Investigated in this work, other polymers may also produce adduct and decay series in MALDI analysis. Their presence can mask the presence of minor components in a sample, but at least as observed here, do not have a strong influence on molecular mass determinations. (J Am Soc Mass Spectrom 2000, 11, 1095-1106) (C) 2000 American Society for Mass Spectrometry. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Goldschmidt, RJ (reprint author), Natl Inst Stand & Technol, Div Polymers, 100 Bur Dr Stop 8541, Gaithersburg, MD 20899 USA. NR 53 TC 23 Z9 23 U1 2 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD DEC PY 2000 VL 11 IS 12 BP 1095 EP 1106 DI 10.1016/S1044-0305(00)00177-X PG 12 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 378CZ UT WOS:000165568600008 PM 11118117 ER PT J AU Matthews, AJ Kiladis, GN AF Matthews, AJ Kiladis, GN TI A model of Rossby waves linked to submonthly convection over the eastern tropical Pacific SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID NORTHERN WINTER; EXTRATROPICAL INTERACTION; PROPAGATION; CIRCULATION; ATMOSPHERE; FREQUENCY AB Equatorward-propagating wave trains in the upper troposphere are observed to be associated with deep convection over the eastern tropical Pacific on the submonthly timescale during northern winter. The convection occurs in the regions of ascent and reduced static stability ahead of cyclonic anomalies in the wave train. In this study an atmospheric primitive equation model is used to examine the roles of the dry wave dynamics and the diabatic heating associated with the convection. Many features of a dry integration initialized with a localized wave train in the African-Asian jet on a three-dimensional climatological basic state quantitatively agree with the observations, including the zonal wavenumber 6-7 scale of the waves, the time period of approximately 12 days, and the cross-equatorial Rossby wave propagation over the eastern Pacific. There is ascent and reduced static stability ahead of the cyclonic anomalies, consistent with the interpretation that the waves force the convection. The spatial scale of the waves appears to be set by the basic state; baroclinic growth upstream in the Asian jet favors waves with zonal wavenumber 6. On reaching the Pacific sector, lower-wavenumber components of the wave train are not refracted so strongly equatorward, while higher-wavenumber components are advected quickly along the Pacific jet before they can propagate equatorward. Once over the Pacific, the wave train approximately obeys barotropic Rossby wave dynamics. The observed lower-tropospheric anomalies include an equatorial Rossby wave that propagates westward from the region of cross-equatorial wave propagation and tropical convection. However, this equatorial Rossby wave is not forced directly by the dry equatorward-propagating wave train but appears in a separate integration as a forced response to the observed diabatic heating associated with the tropical convection. C1 Monash Univ, Cooperat Res Ctr So Hemisphere Meteorol, Melbourne, Vic 3004, Australia. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Matthews, AJ (reprint author), Univ E Anglia, Sch Environm Sci, Norwich NR4 7TJ, Norfolk, England. RI Matthews, Adrian/A-6444-2011 OI Matthews, Adrian/0000-0003-0492-1168 NR 25 TC 13 Z9 13 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 2000 VL 57 IS 23 BP 3785 EP 3798 DI 10.1175/1520-0469(2000)057<3785:AMORWL>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 380TZ UT WOS:000165720700001 ER PT J AU Moffat, TP Bonevich, JE Huber, WH Stanishevsky, A Kelly, DR Stafford, GR Josell, D AF Moffat, TP Bonevich, JE Huber, WH Stanishevsky, A Kelly, DR Stafford, GR Josell, D TI Superconformal electrodeposition of copper in 500-90 nm features SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID IN-SITU STM; SULFURIC-ACID-SOLUTION; ASPECT-RATIO TRENCHES; POLYETHYLENE-GLYCOL; 4,5-DITHIAOCTANE-1,8-DISULFONIC ACID; ELECTROPLATING BATH; ORGANIC ADDITIVES; ROOM-TEMPERATURE; DISK ELECTRODE; BENZOTRIAZOLE AB Superconformal electrodeposition of copper in 500 nm deep trenches ranging from 500 to 90 nm in width has been demonstrated using an acid cupric sulfate electrolyte containing chloride (Cl). polyethylene glycol (PEG), and 3-mercapto-1-propanesulfonate (MPSA). In contrast, similar experiments using either an additive-free electrolyte, or an electrolyte containing the binary combinations Cl-PEG. Cl-MPSA. or simply benzotriazole (BTAH), resulted in the formation of a continuous void within the center of the trench. Void formation in the latter electrolytes is shown to be reduced through the geometrical leveling effect associated with conformal deposition in trenches or vias with sloping sidewalls. The slanted sidewalls also counterbalance the influence of the differential cupric ion concentration that develops within the trenches. Examination of the i-E deposition characteristics of the electrolytes reveals a hysteretic response associated with the Cl-PEG-MPSA electrolyte that can be usefully employed to monitor and explore additive efficacy and consumption. Likewise, resistivity measurements performed on corresponding blanket films can be used to quantify the extent of additive incorporation and its influence on microstructural evolution. The films deposited from the Cl-PEG-MPSA electrolyte exhibit spontaneous recrystallization at room temperature that results in a 23% drop in resistivity with in a few hours of deposition. (C) 2000 The Electrochemical Society. S0013-4651(00)04-078-7. All rights reserved. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, Inst Plasma Res, College Pk, MD 20742 USA. RP Moffat, TP (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. EM tmoffat@nist.gov NR 51 TC 323 Z9 323 U1 15 U2 118 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 2000 VL 147 IS 12 BP 4524 EP 4535 DI 10.1149/1.1394096 PG 12 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 376RD UT WOS:000165469800022 ER PT J AU Wu, CC Bender, MA Kurihara, Y AF Wu, CC Bender, MA Kurihara, Y TI Typhoon forecast with the GFDL hurricane model: Forecast skill and comparison of predictions using AVN and NOGAPS global analyses SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID TROPICAL CYCLONE TRACK; SYSTEM; IMPROVEMENTS; PERFORMANCE; INTENSITY; ENSEMBLE AB A hurricane model developed at GFDL, NOAA, was combined with each of AVN and NOGAPS global analyses to construct typhoon prediction systems GFDS and GFDN, respectively. The CFDS system performed 125 (178) forecast experiments for 16 (24) storms in the western North Pacific basin during 1995 (1996). It exhibited considerable skill in the forecast of tropical cyclone tracks. The average forecast position errors at 12, 24, 36, 48 and 72 h in 1995 (1996) were 95 (108), 146 (178), 193 (227), 249 (280), and 465 (480) km. The improvement with GFDS in the typhoon position forecast over CLIPER was roughly 30 (ro. The reduction of position errors in both average and standard deviations indicates superior forecast accuracy and consistency of GFDS, although there existed systematic northward bias in the forecast motion at low latitudes. On the other hand, intensity forecast was not satisfactory, showing a tendency to overpredict weak storms and underpredict strong storms, similar to the tendency in the Atlantic. Two sets of forecasts performed in the 1996 season, the one by GFDS and the other by GFDN, were compared with each other. Forecast skills of the storm position with the two systems were comparable. However, the two forecast positions tended to be systematically biased toward different directions. As a result, when the two forecasts were averaged, the mean error was 10 % smaller than that of each forecast. Also, overall improvement in track forecast was obtained in supplemental experiments in which individual forecasts were corrected for systematic biases. Though systematic bias is not steady, there may be ways to utilize it for improvement of tropical cyclone forecasts. C1 Natl Taiwan Univ, Dept Atmospher Sci, Taipei 10772, Taiwan. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Wu, CC (reprint author), Natl Taiwan Univ, Dept Atmospher Sci, 61 Ln 144,Sec 4,Keelung Rd, Taipei 10772, Taiwan. EM cwu@typhoon.as.ntu.edu.tw OI Wu, Chun-Chieh/0000-0002-3612-4537 NR 15 TC 9 Z9 10 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 DEC PY 2000 VL 78 IS 6 BP 777 EP 788 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 403MN UT WOS:000167047200007 ER PT J AU Trainer, VL Adams, NG Bill, BD Stehr, CM Wekell, JC Moeller, P Busman, M Woodruff, D AF Trainer, VL Adams, NG Bill, BD Stehr, CM Wekell, JC Moeller, P Busman, M Woodruff, D TI Domoic acid production near California coastal upwelling zones, June 1998 SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID DIATOM PSEUDONITZSCHIA-AUSTRALIS; PRINCE-EDWARD-ISLAND; POINT CONCEPTION; PSEUDO-NITZSCHIA; MONTEREY BAY; WHOLE-CELL; WEST-COAST; SEA LIONS; IDENTIFICATION; SHELLFISH AB Sea lion mortalities in central California during May and June 1998 were traced to their ingestion of sardines and anchovies that had accumulated the neurotoxin domoic acid. The detection of toxin in urine, feces, and stomach contents of several sea lions represents the first proven occurrence of domoic acid transfer through the food chain to a marine mammal. The pennate diatoms, Pseudo-nitzschia multiseries and P. australis, were the dominant, toxin-producing phytoplankton constituting algal blooms near Monterey Bay, Half Moon Bay, and Oceano Dunes, areas where sea lions with neurological symptoms stranded. Toxic Psendo-nitzschia were also found near Morro Bay, Paint Conception, Point Arguello, and Santa Barbara, demonstrating that these species were widespread along the central California coast in June 1998. Measurements of domoic acid during three cruises in early June showed the highest cellular toxin levels in P. multiseries near Point Ano Nuevo at 6 pg cell(-1) and in P. australis from Morro Bay at 78 pg cell(-1). Maximum cellular domoic acid levels were observed within 20 ion of the coast between 0 and 5 m depth, although toxin was also measured to depths of 40 m. Hydrographic data indicated that the highest toxin levels and greatest numbers of toxic cells were positioned in water masses associated with upwelling zones near coastal headlands. Nutrient levels at these sites were less than those typically measured during periods of active upwelling, due to the 1998 El Nino event. The flow of cells and/or nutrients from coastal headlands into embayments where cells can multiply in a stratified environment is a possible mechanism of bloom development along the central California coast. This coupling of toxic Pseudo-nitzschia growth near upwelling zones with physical processes involved in cell transport will be understood only when long-term measurements are made at several key coastal locations, aiding in our capability to predict domoic-acid producing algal blooms. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Trainer, VL (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM Vera.L.Trainer@noaa.gov NR 54 TC 108 Z9 110 U1 1 U2 25 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD DEC PY 2000 VL 45 IS 8 BP 1818 EP 1833 PG 16 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 382QX UT WOS:000165834700015 ER PT J AU Garza, JC Desmarais, E AF Garza, JC Desmarais, E TI Derivation of a simple microsatellite locus from a compound ancestor in the genus Mus SO MAMMALIAN GENOME LA English DT Article ID DNA-SEQUENCES; SIZE HOMOPLASY; HOUSE MOUSE; EVOLUTION; PHYLOGENY; MUTATIONS; ORIGIN; POLYMORPHISMS; CHIMPANZEES; FRAMESHIFT AB Many microsatellite loci contain more than a single repeat motif. These compound microsatellites are perhaps most easily explained as arising from simple ancestors. We have uncovered a contrary example in mice of the genus Mus. Sequence analysis of the locus D1MIT29 in most of the members of the genus Mus reveals that this locus is compound in all species except M. musculus, in which it is simple. Moreover, phylogenetic analyses of base substitutions in the non-repetitive flanking region gives trees which are consistent with the previously accepted phylogenetic hypothesis that M. musculus is nested within the subgenus Mus. This confirms that the history of this locus is similar to that of molecular markers previously used in phylogenetic studies of this group and, therefore, demonstrates that the simple state in this lineage is derived from a compound ancestor. We also demonstrate the utility of this type of nuclear sequence variation for phylogeographic studies in the genus Mus. Finally, our sequences reveal homoplasy for size, reemphasizing the danger of using microsatellite size variation alone when the individuals under study are not closely related. C1 Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Univ Montpellier 2, CNRS, UPR 9060, Lab Genome & Populat, F-34095 Montpellier 5, France. RP Garza, JC (reprint author), Natl Marine Fisheries Serv, Santa Cruz Lab, 110 Shaffer Rd, Santa Cruz, CA 95060 USA. FU NIGMS NIH HHS [GM40282] NR 31 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD DEC PY 2000 VL 11 IS 12 BP 1117 EP 1122 DI 10.1007/s003350010200 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 378XR UT WOS:000165611100012 PM 11130981 ER PT J AU Sol, SY Johnson, LL Horness, BH Collier, TK AF Sol, SY Johnson, LL Horness, BH Collier, TK TI Relationship between oil exposure and reproductive parameters in fish collected following the Exxon Valdez oil spill SO MARINE POLLUTION BULLETIN LA English DT Article DE oil spill; hydrocarbons; reproduction; dolly varden; pollock; yellowfin sole ID SOLE PAROPHRYS-VETULUS; ENGLISH SOLE; PUGET-SOUND; AROMATIC-COMPOUNDS; COHO SALMON; CRUDE-OIL; WASHINGTON; STEROIDS; BILE AB Following the Exxon Valdez oil spill (EVOS) in 1989, the effect of oil exposure on reproductive parameters was investigated in wild populations of female dolly varden, yellowfin sole, and pollock, Exposure to oil was the highest in the first year of sampling and decreased in the subsequent years of sampling, Both positive and negative correlations between reproductive parameters and indices of exposure were detected in varying degrees for all three species. Reproductive parameters were not measured in the first year of sampling. For those parameters found to be significantly correlated to oil exposure, an exponential regression function was used to project reproductive parameters of fish sampled in the first year of the spill. A higher proportion of dolly varden sampled in 1989 were projected to have depressed plasma estradiol-17 beta compared to the fish sampled in 1990, Published by Elsevier Science Ltd. C1 Natl Oceanog & Atmospher Adm, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Natl Oceanog & Atmospher Adm, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 35 TC 12 Z9 13 U1 0 U2 6 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 DEC PY 2000 VL 40 IS 12 BP 1139 EP 1147 DI 10.1016/S0025-326X(00)00074-6 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 384PU UT WOS:000165954700022 ER PT J AU Rozas, LP Minello, TJ Henry, CB AF Rozas, LP Minello, TJ Henry, CB TI An assessment of potential oil spill damage to salt marsh habitats and fishery resources in Galveston Bay, Texas SO MARINE POLLUTION BULLETIN LA English DT Article DE benthic infauna; estuary; fisheries; nekton; salt marsh; sediment hydrocarbon concentration ID CRUDE-OIL; AROMATIC-HYDROCARBONS; PENAEUS-AZTECUS; WEST-FALMOUTH; SEDIMENTS; IMPACT; WATER; POPULATIONS; SELECTION; PETROLEUM AB We sampled nekton, benthic infauna, and sediments in salt marshes of upper Galveston Bay, Texas to examine relationships between habitat use and sediment hydrocarbon concentration. Most marsh sediment samples were contaminated with relatively low concentrations of weathered petroleum hydrocarbons. We found few statistically significant negative relationships between animal density and hydrocarbon concentration (6 of 63 taxa examined using simple linear regression). Hydrocarbon concentration did not contribute significantly to Stepwise Multiple Regression models we used to explore potential relationships between animal densities and environmental parameters; in most cases where hydrocarbon concentration was an important variable in the models, the relationship was positive (i.e., animal densities increased with hydrocarbon concentration). Low hydrocarbon concentrations in sediments of upper Galveston Bay marshes could have contributed to our results either because levels were too low to be toxic or levels were toxic but too low to be detected by most organisms. Published by Elsevier Science Ltd. C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Fishery Ecol Branch, Galveston Lab, Galveston, TX 77551 USA. NOAA Hazmat, Seattle, WA 98115 USA. RP Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Fishery Ecol Branch, Galveston Lab, 4700 Ave U, Galveston, TX 77551 USA. EM lawrence.rozas@noaa.gov NR 55 TC 13 Z9 13 U1 0 U2 21 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 DEC PY 2000 VL 40 IS 12 BP 1148 EP 1160 DI 10.1016/S0025-326X(00)00075-8 PG 13 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 384PU UT WOS:000165954700023 ER PT J AU Kesling, DE AF Kesling, DE TI Scientific diving - Why man? SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 Univ N Carolina, Natl Undersea Res Ctr, NOAA, Wilmington, NC 28401 USA. RP Kesling, DE (reprint author), Univ N Carolina, Natl Undersea Res Ctr, NOAA, Wilmington, NC 28401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD WIN PY 2000 VL 34 IS 4 BP 3 EP 4 PG 2 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 396UN UT WOS:000166655000001 ER PT J AU Dinsmore, DA AF Dinsmore, DA TI The history of diving within the National Oceanic and Atmospheric Administration (NOAA) SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB As the nation's premiere ocean science agency, the National Oceanic and Atmospheric Administration (NOAA) has a variety of programs that require research below the ocean's surface. This research is conducted using a variety of diving methodologies, including wet diving, seafloor habitats, remotely operated vehicles, and manned submersibles. For almost fifty years NOAA and its predecessors, the Bureau of Commercial Fisheries and the Coast and Geodetic Survey, have been actively involved in undersea research. Many of the lessons Learned and technologies developed during this time have been adopted by the recreational, scientific, and military diving communities, thus benefiting divers everywhere. This paper traces the history of NOAA's two major diving prog rams; the NOAA Diving Program and the National Undersea Research Program, and highlights some of the significant accomplishments of each program. C1 NOAA, Diving Program, Seattle, WA 98115 USA. RP Dinsmore, DA (reprint author), NOAA, Diving Program, Seattle, WA 98115 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD WIN PY 2000 VL 34 IS 4 BP 11 EP 22 PG 12 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 396UN UT WOS:000166655000003 ER PT J AU Boettinger, WJ Williams, ME Coriell, SR Kattner, UR Mueller, BA AF Boettinger, WJ Williams, ME Coriell, SR Kattner, UR Mueller, BA TI Alpha case thickness modeling in investment castings SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID TITANIUM AB The alpha case thickness at the surface of a Ti-6Al-4V (wt pet) step wedge investment casting has been measured and successfully predicted. The prediction uses temperature-time results obtained from a heat flow simulation of the casting. The temperature-time results were coupled to a simple model for diffusion of oxygen into the beta phase during continuous cooling. Oxygen concentration and microhardness profiles were measured from the surface in contact with the ZrO(2) face coat of the shell mold into the interior of the casting. The oxygen content in the metal at the shell mold interface was between 5 and 9.5 wt pet in general agreement with a thermodynamic calculation for bcc Ti in contact with ZrO(2). At the limit of the alpha case region, as determined by standard metallographic technique, the oxygen concentration was found to be no more than 0.02 wt pet above the level of oxygen in the bulk alloy. Using this information and one particular literature value for the activation energy for diffusion of oxygen, a nearly linear relationship was obtained between the measured and predicted alpha case thicknesses at various positions on the casting surface. Reduction of the prefactor of this diffusion coefficient by a factor of 7.5 produces excellent agreement between predicted and measured alpha case thicknesses. Such a reduction is not inconsistent with the scatter of literature values for the diffusion coefficient. C1 NIST, Div Met, Gaithersburg, MD 20899 USA. Howmet Corp, Whitehall, MI 49461 USA. RP Boettinger, WJ (reprint author), NIST, Div Met, Gaithersburg, MD 20899 USA. NR 9 TC 29 Z9 31 U1 0 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD DEC PY 2000 VL 31 IS 6 BP 1419 EP 1427 DI 10.1007/s11663-000-0026-y PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 386FR UT WOS:000166050600026 ER PT J AU Shu, JF Munson, A Rhodes, M Rearick, M Rosenwald, AG AF Shu, JF Munson, A Rhodes, M Rearick, M Rosenwald, AG TI ARL1 and ATC1/LIC4 interact to regulate lithium homeostasis in Saccharomyces cerevisiae SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Georgetown Univ, Washington, DC 20057 USA. Natl Inst Stand & Technol, Washington, DC 20057 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 1758 BP 339A EP 339A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525901762 ER PT J AU Rao, DV Cesareo, R Brunetti, A Gigante, GE AF Rao, DV Cesareo, R Brunetti, A Gigante, GE TI Computed tomography with image intensifier: potential use for nondestructive testing and imaging of small objects SO NDT & E INTERNATIONAL LA English DT Article DE computed tomography; image intensifier; nondestructive imaging AB An image intensifier based computed tomography scanner and a tube source of X-rays are used for nondestructive evaluation, imaging of small objects for archaeological studies and conservation of works of art and micro analysis of soft materials. It consists of a charge coupled device (CCD) camera and an acquisition board. The CCD camera and the acquisition board allow image processing, filtration and restoration. The object is irradiated by an X-ray tube with a conical collimator and rotated on 180 degrees. Projections are obtained at various angles as cross sectional image slices. A reconstruction program written in PASCAL is able to give the reconstruction matrix of the linear attenuation coefficients, simulates the matrix and related tomography, The flux emitted by the tube is filtered using the appropriate filters at the chosen optimum energy and reasonable monochromacy is achieved for all the images. Although X-ray imaging is a potential tool for strongly attenuating materials, the images of weakly attenuating materials provide new information to know about their structure and also the foreign body for the image reconstruction at an optimum value, The image of the plastic material which contains the internal defect is studied thoroughly at the optimum value in order to image the small objects for nondestructive testing, archaeological studies and conservation of works of art, The images are analysed using the profile data showing the internal defect of the object to obtain information at the optimum value. At the optimum value and with the aid of the tomographic image, the size and location of the defect could be ascertained. (C) 2000 Elsevier Science Ltd, All rights reserved. C1 Sir CRR Autonomous Coll, Dept Phys, Eluru 534007, Andhra Pradesh, India. Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. Univ Sassari, Ist Matemat & Fis, I-07100 Sassari, Italy. Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. RP Rao, DV (reprint author), Natl Inst Stand & Technol, Ionizing Radiat Div 8460, Radiat Phys Bldg 245, Gaithersburg, MD 20899 USA. RI brunetti, antonio/F-3370-2011; OI brunetti, antonio/0000-0002-0116-1899; Gigante, Giovanni Ettore/0000-0001-5943-9366 NR 7 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0963-8695 J9 NDT&E INT JI NDT E Int. PD DEC PY 2000 VL 33 IS 8 BP 523 EP 530 DI 10.1016/S0963-8695(00)00002-5 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA 371ZE UT WOS:000165208500002 ER PT J AU Muir, WD McCabe, GT Parsley, MJ Hinton, SA AF Muir, WD McCabe, GT Parsley, MJ Hinton, SA TI Diet of first-feeding larval and young-of-the-year white sturgeon in the lower Columbia River SO NORTHWEST SCIENCE LA English DT Article ID ACIPENSER-TRANSMONTANUS; FISHES; FOOD AB In some Snake and Columbia River reservoirs, adult white sturgeon (Acipenser transmontanus) are common but few juvenile fish are found, indicating a lack of spawning success or poor survival of larvae. In contrast, recruitment of young-of-the-year white sturgeon to juvenile and adult stages is successful in the unimpounded Columbia River downstream of Bonneville Dam. The availability and size of preferred prey during the period when white sturgeon larvae begin exogenous feeding could be an important determinant of year-class strength. To explore this issue, we examined the diet composition of 352 larval and young-of-the year white sturgeon collected from 1989 through 1991 in the lower Columbia River. Samples were collected downstream from Bonneville Dam and upstream from the dam in Bonneville and The Dalles Reservoirs. Fish that ranged in size from 15 to 290 mm in total length fed primarily on gammarid amphipods (Corophium spp.) during all months. This diet item became increasingly important to all sizes of white sturgeon examined as they grew. The length of Corophium spp. eaten by larval and young-of-the-year white sturgeon increased with increasing fish length (r(2) = 45.6%, P < 0.0001). Copepods (Cyclopoida), Ceratopogonidae larvae, and Diptera pupae and larvae (primarily chironomids) were also consumed, especially at the onset of exogenous feeding. A small percentage of white sturgeon were found with empty stomachs during June (1.6% downstream from Bonneville Dam) and July (4.5% downstream and 2.6% in the reservoirs). Diets of larval and young-of-the year white sturgeon from both impounded and free-flowing sections of the Columbia River were similar and we found no evidence of larval starvation in the areas investigated, areas currently supporting healthy white sturgeon populations. C1 Natl Marine Fisheries Serv, Fish Ecol Div, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Muir, WD (reprint author), Natl Marine Fisheries Serv, Fish Ecol Div, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 39 TC 13 Z9 13 U1 2 U2 10 PU WASHINGTON STATE UNIV PI PULLMAN PA PO BOX 645910, PULLMAN, WA 99164-5910 USA SN 0029-344X J9 NORTHWEST SCI JI Northwest Sci. PD WIN PY 2000 VL 74 IS 1 BP 25 EP 33 PG 9 WC Ecology SC Environmental Sciences & Ecology GA 302MR UT WOS:000086369600005 ER PT J AU Dherin, C Dizdaroglu, M Doerflinger, H Boiteux, S Radicella, JP AF Dherin, C Dizdaroglu, M Doerflinger, H Boiteux, S Radicella, JP TI Repair of oxidative DNA damage in Drosophila melanogaster: identification and characterization of dOgg1, a second DNA glycosylase activity for 8-hydroxyguanine and formamidopyrimidines SO NUCLEIC ACIDS RESEARCH LA English DT Article ID BASE EXCISION-REPAIR; SACCHAROMYCES-CEREVISIAE; OGG1 PROTEIN; ESCHERICHIA-COLI; SUBSTRATE-SPECIFICITY; MOLECULAR-CLONING; REACTIVE OXYGEN; FREE-RADICALS; HUMAN HOMOLOG; GENE AB In Drosophila, the S3 ribosomal protein has been shown to act as a DNA glycosylase/AP lyase capable of releasing 8-hydroxyguanine (8-OH-Gua) in damaged DNA. Here we describe a second Drosophila protein (dOgg1) with 8-OH-Gua and abasic (AP) site DNA repair activities. The Drosophila OGG1 gene codes for a protein of 327 amino acids, which shows 33 and 37% identity with the yeast and human Ogg1 proteins, respectively. The DNA glycosylase activity of purified dOgg1 was investigated using gamma -irradiated DNA and gas chromatography/ isotope dilution mass spectrometry (GC/IDMS). The dOgg1 protein excises 8-OH-Gua and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua) from gamma -irradiated DNA. with k(cat)/K(M) values of 21.0 x 10(-5) and 11.2 x 10(-5) (min(-1) nM(-1)), respectively. Enzymatic assays using oligodeoxyribonucleotides containing a single lesion show that dOgg1 displays a marked preference for DNA duplexes containing 8-OH-Gua, 8-OH-Ade or an AP site placed opposite a cytosine, The cleavage of the 8-OH-Gua-containing strand results from the excision of the damaged base followed by a beta -elimination reaction at the 3'-side of the resulting AP site. Cleavage of 8-OH-Gua.C duplex involves the formation of a reaction intermediate that is converted into a stable covalent adduct in the presence of sodium borohydre. dOgg1 complements the mutator phenotype of fpg mutY mutants of Escherichia coli. Whole-mount in situ hybridizations on tissues at different stages of Drosophila development reveal that the dOGG1 messenger is expressed uniformly at a low level in cells in which mitotic division occurs. Therefore, Drosophila possesses two DNA glycosylase activities that can excise 8-OH-Gua and formamidopyrimidines from DNA, dOgg1 and the ribosomal protein S3. C1 CEA, Dept Radiobiol & Radiopathol, CNRS, UMR 217, F-92265 Fontenay Aux Roses, France. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Paris 06, Univ Paris 07, CNRS, Inst Jacques Monod, F-75251 Paris, France. RP Radicella, JP (reprint author), CEA, Dept Radiobiol & Radiopathol, CNRS, UMR 217, 60 Rue Gen Leclerc,BP6, F-92265 Fontenay Aux Roses, France. EM jpradicella@cea.fr NR 54 TC 37 Z9 39 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD DEC 1 PY 2000 VL 28 IS 23 BP 4583 EP 4592 DI 10.1093/nar/28.23.4583 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 381QL UT WOS:000165774400003 PM 11095666 ER PT J AU Patel, JK Govindarajan, M Shevgaonkar, RK AF Patel, JK Govindarajan, M Shevgaonkar, RK TI Analysis of diffuse indoor infrared data links SO OPTICAL AND QUANTUM ELECTRONICS LA English DT Article DE optical communication; infrared; indoor wireless communication ID CHANNELS AB The authors present a simple channel model for diffuse infra-red indoor data communication systems. Based on the model, important trade-offs between the transmitted optical power, the bit-rate, and the receiver parameters are presented for the first time. C1 Natl Inst Stand & Technol, Adv Network Technol Div, Gaithersburg, MD 20899 USA. Indian Inst Technol, Dept Elect Engn, Bombay 400076, Maharashtra, India. RP Patel, JK (reprint author), Natl Inst Stand & Technol, Adv Network Technol Div, 820 W Diamond Ave, Gaithersburg, MD 20899 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0306-8919 J9 OPT QUANT ELECTRON JI Opt. Quantum Electron. PD DEC PY 2000 VL 32 IS 12 BP 1319 EP 1323 DI 10.1023/A:1026415911018 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA 381WX UT WOS:000165788000005 ER PT J AU Michels, A Weissmuller, J Wiedenmann, A Pedersen, JA Barker, JG AF Michels, A Weissmuller, J Wiedenmann, A Pedersen, JA Barker, JG TI Measuring the exchange-stiffness constant of nanocrystalline solids by elastic small-angle neutron scattering SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID MAGNETIC MICROSTRUCTURE; NANOSTRUCTURED FE; FERROMAGNETIC NI; SPIN-WAVES; NICKEL; DISPERSION; CO AB In ferromagnets with a non-uniform magnetocrystalline and/or magnetoelastic anisotropy, such as nanocrystalline or cold-worked polycrystalline materials, the static magnetic microstructure gives rise to elastic magnetic small-angle neutron scattering (SANS). The paper explores a method for determining the exchange-stiffness constant A by analysis of the dependence of the elastic SANS cross-section on the applied magnetic field. Experimental results for A and for the spin-wave stiffness constant D in cold-worked or nanocrystalline Ni and Co are found to agree with literature data obtained by inelastic neutron scattering on single-crystal specimens. C1 Univ Saarland, D-66041 Saarbrucken, Germany. Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. Riso Natl Lab, DK-4000 Roskilde, Denmark. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Michels, A (reprint author), Univ Saarland, D-66041 Saarbrucken, Germany. EM anmi@nano.uni-saarland.de RI Weissmuller, Jorg/C-3967-2009; Pedersen, Jan/A-8346-2008; Michels, Andreas/F-6588-2014 OI Weissmuller, Jorg/0000-0002-8958-4414; Pedersen, Jan/0000-0002-7768-0206; NR 19 TC 22 Z9 22 U1 2 U2 9 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD DEC PY 2000 VL 80 IS 12 BP 785 EP 792 DI 10.1080/0950083001000180S PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 382BP UT WOS:000165798800005 ER PT J AU Nave, G Griesmann, U AF Nave, G Griesmann, U TI New energy levels and classifications of spectral lines from neutral and singly-ionized dysprosium (Dy I and dy II) SO PHYSICA SCRIPTA LA English DT Article ID VACUUM ULTRAVIOLET; HOLLOW-CATHODE AB We present new energy-level classifications for over 400 lines in the spectra of neutral and singly-ionized dysprosium. These lines were observed using Fourier transform spectrometry of high current hollow cathode lamps and cover the wavelength range 230 nm to 1.6 mum. They were classified by 43 new energy levels of Dy I and 24 new energy levels of Dy II. The standard uncertainty of the energy levels and the strongest lines is estimated at 0.005 cm(-1). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nave, G (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 4 Z9 5 U1 1 U2 2 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD DEC PY 2000 VL 62 IS 6 BP 463 EP 473 DI 10.1238/Physica.Regular.062a00463 PG 11 WC Physics, Multidisciplinary SC Physics GA 382LK UT WOS:000165823600005 ER PT J AU Branning, D Migdall, AL Sergienko, AV AF Branning, D Migdall, AL Sergienko, AV TI Simultaneous measurement of group and phase delay between two photons SO PHYSICAL REVIEW A LA English DT Article ID POLARIZATION MODE DISPERSION; 2 PHOTONS; INTERFERENCE; CANCELLATION; TIME; CONVERSION AB We report on an experiment to determine both the group and phase delays experienced by orthogonally polarized photon pairs traveling through a birefringent medium. Both types of delay are determined from the same set of coincidence-counting data. The experiment is based on an interference technique using two-photon multipath indistinguishability to produce an interference feature. Earlier work has shown that this interference feature can be used to measure the group velocity of single-photon wave packets in dielectric media. In the current: work, the two-photon interferometer has been modified to produce an additional interference feature that is sensitive to the phase velocity of the light. We have used this technique to simultaneously measure the group delay in crystal quartz with a precision of 0.1 fs and the phase delay with a precision of 8 attoseconds. Our analysis clarifies the effects of group and phase delays and shows the unexpected result that dispersive temporal broadening, which is well known to be canceled for the original interferometer setup, is not canceled for this type of ''postponed compensation'' interferometer. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Boston Univ, Dept Elect & Comp Engn, Boston, MA 02215 USA. RP NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 21 TC 25 Z9 25 U1 0 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 DEC PY 2000 VL 62 IS 6 AR 063808 DI 10.1103/PhysRevA.62.063808 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200103 ER PT J AU Carr, LD Clark, CW Reinhardt, WP AF Carr, LD Clark, CW Reinhardt, WP TI Stationary solutions of the one-dimensional nonlinear Schrodinger equation. I. Case of repulsive nonlinearity SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATE; SOLITARY WAVES; SOLITONS; GASES; DYNAMICS; STATES AB All stationary solutions to the one-dimensional nonlinear Schrodinger equation under box and periodic boundary conditions are presented in analytic form. We consider the case of repulsive nonlinearity; in a companion paper we treat the attractive case. Our solutions take the form of stationary trains of dark or gray density-notch solitons. Real stationary states are in one-to-one correspondence with those of the linear Schrodinger equation. Complex stationary states are uniquely nonlinear, nodeless, and symmetry breaking. Our solutions apply to many physical contexts, including the Bose-Einstein condensate and optical pulses in fibers. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. US Dept Commerce, Technol Adm, Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. RP Carr, LD (reprint author), Univ Washington, Dept Phys, Seattle, WA 98195 USA. RI Clark, Charles/A-8594-2009; Carr, Lincoln/E-3819-2016 OI Clark, Charles/0000-0001-8724-9885; Carr, Lincoln/0000-0002-4848-7941 NR 41 TC 191 Z9 192 U1 0 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 063610 DI 10.1103/PhysRevA.62.063610 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200088 ER PT J AU Carr, LD Clark, CW Reinhardt, WP AF Carr, LD Clark, CW Reinhardt, WP TI Stationary solutions of the one-dimensional nonlinear Schrodinger equation. II. Case of attractive nonlinearity SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATE; FESHBACH RESONANCES; SCATTERING; COLLAPSE; SOLITON AB All stationary solutions to the one-dimensional nonlinear Schrodinger equation under box or periodic boundary conditions are presented in analytic form for the case of attractive nonlinearity. A companion paper treated the repulsive case. Our solutions take the form of bounded, quantized, stationary trains of bright solitons. Among them are two uniquely nonlinear classes of nodeless solutions, whose properties and physical meaning are discussed in detail. The full set of symmetry-breaking stationary states are described by the C-n, character tables from the theory of point groups. We make experimental predictions for the Bose-Einstein condensate, and show that, though these are the analog of some of the simplest problems in linear quantum mechanics, nonlinearity introduces surprising phenomena. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. US Dept Commerce, Technol Adm, Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. RP Carr, LD (reprint author), Univ Washington, Dept Phys, Seattle, WA 98195 USA. RI Clark, Charles/A-8594-2009; Carr, Lincoln/E-3819-2016 OI Clark, Charles/0000-0001-8724-9885; Carr, Lincoln/0000-0002-4848-7941 NR 27 TC 151 Z9 152 U1 1 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 DEC PY 2000 VL 62 IS 6 AR 063611 DI 10.1103/PhysRevA.62.063611 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200089 ER PT J AU Skripov, AV Cook, JC Udovic, TJ Kozhanov, VN AF Skripov, AV Cook, JC Udovic, TJ Kozhanov, VN TI Quasielastic neutron scattering study of hydrogen motion in C15-type HfMo2H0.26 SO PHYSICAL REVIEW B LA English DT Article ID H(D) ATOMS; DIFFUSION; ZRCR2HX AB In order to evaluate the parameters of H motion in the cubic (C15-type) Laves phase HfMo2, we have performed quasielastic neutron scattering measurements on HfMo2H0.26 in the temperature range 15-390 K. The results are consistent with the fast localized I-I motion within the hexagons formed by interstitial g(Hf2Mo2) sites. The slower jump process corresponding to H hopping from one hexagon to another has been probed by recent proton NMR measurements [A. V. Skripov et al., J. Phys.: Condens. Matter 11, 10 393 (1999)]. Comparison of the NMR and the quasielastic neutron scattering results shows that the ratio of the characteristic hopping rates for the two jump processes, tau (d)/taul, is 2.4X 10(3) at 300 K; this ratio increases with decreasing temperature. For the series of CIS-type AB(2) compounds TaV2-HfMo2-ZrMo2-ZrCr2, it is found that the increase in the ratio of the metallic radii of the elements A and B, R-A/R-B, leads to the decrease in tau (d)/tau (l). C1 Russian Acad Sci, Ural Branch, Inst Phys Met, Ekaterinburg 620219, Russia. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Skripov, AV (reprint author), Russian Acad Sci, Ural Branch, Inst Phys Met, Ekaterinburg 620219, Russia. RI Skripov, Alexander/K-4525-2013 OI Skripov, Alexander/0000-0002-0610-5538 NR 24 TC 26 Z9 26 U1 0 U2 0 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 DEC 1 PY 2000 VL 62 IS 21 BP 14099 EP 14104 DI 10.1103/PhysRevB.62.14099 PG 6 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200052 ER PT J AU Hwang, SR Li, WH Lee, KC Lynn, JW Wu, CG AF Hwang, SR Li, WH Lee, KC Lynn, JW Wu, CG TI Spiral magnetic structure of Fe in Van der Waals gapped FeOCl and polyaniline-intercalated FeOCl SO PHYSICAL REVIEW B LA English DT Article ID POLYMERS; PYRROLE; SYSTEM AB High-resolution and magnetic neutron-diffraction measurements were performed to investigate the crystal and magnetic structures of bilayered FeOCl and polyaniline-intercalated FeOCl. A quasi-two-dimensional crystallographic structure, where charge neutral (Fe2O2Cl2)(n) lamellas are weakly linked via Van der Waals interactions, has made FeOCl a good host for accommodating guest molecules. A three-dimensional long-range ordering of the Fe spins in FeOCl develops below 80 K, with a magnetic unit cell 28 times the size of the nuclear one. A spiral magnetic structure was obtained, reflecting the competition between antiferromagnetic superexchange coupling and ferromagnetic direct exchange coupling. Polyaniline intercalation interrupts the magnetic correlations between the neighboring bilayers, rendering a coupled-bilayer quasi-two-dimensional magnetic order for the Fe spins in (C6D4ND)(0.16)FeOCl, No significant change on the ordering temperature of the Fe spins by the intercalation reaction was observed. C1 Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Natl Cent Univ, Dept Chem, Chungli 32054, Taiwan. RP Hwang, SR (reprint author), Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NR 32 TC 16 Z9 17 U1 5 U2 31 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 DEC 1 PY 2000 VL 62 IS 21 BP 14157 EP 14163 DI 10.1103/PhysRevB.62.14157 PG 7 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200061 ER PT J AU Bao, W Pagliuso, PG Sarrao, JL Thompson, JD Fisk, Z Lynn, JW Erwin, RW AF Bao, W Pagliuso, PG Sarrao, JL Thompson, JD Fisk, Z Lynn, JW Erwin, RW TI Incommensurate magnetic structure of CeRhIn5 SO PHYSICAL REVIEW B LA English DT Article ID CEIN3 AB The magnetic structure of the heavy fermion antiferromagnet CeRhIn5 is determined using neutron diffraction. We find a magnetic wave vector q(M)=(1/2,112,0.297), which is temperature independent up to T-N =3.8 K. A staggered moment of 0.264(4) mu (B) at 1.4 K, residing on the Ce ion, spirals transversely along the c axis. The nearest-neighbor moments on the tetragonal basal plane are aligned antiferromagnetically. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Florida State Univ, Tallahassee, FL 32306 USA. RP Bao, W (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Pagliuso, Pascoal/C-9169-2012; Bao, Wei/E-9988-2011 OI Bao, Wei/0000-0002-2105-461X NR 13 TC 150 Z9 150 U1 1 U2 17 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 DEC 1 PY 2000 VL 62 IS 22 BP 14621 EP 14624 DI 10.1103/PhysRevB.62.R14621 PG 4 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800006 ER PT J AU Yong, G Toulouse, J Erwin, R Shapiro, SM Hennion, B AF Yong, G Toulouse, J Erwin, R Shapiro, SM Hennion, B TI Pretransitional diffuse neutron scattering in the mixed perovskite relaxor K1-xLixTaO3 SO PHYSICAL REVIEW B LA English DT Article ID ELECTRIC-DIPOLE SYSTEM; PHASE-TRANSITION; RAMAN-SCATTERING; KTAO3; CRYSTALS; LI; DIFFRACTION; BEHAVIOR; GLASS; IONS AB Several previous studies of K1-xLixTaO3 (KLT) have revealed the presence, above the structural transition, of polar nanoregions. Recently, these have been shown to play an essential role in the relaxer behavior of KLT. In order to characterize these regions, we have performed a neutron-scattering study of KLT crystals with different lithium concentrations, both above and below the critical concentration. This study reveals the existence of diffuse scattering that appears upon formation of these regions. The rodlike distribution of the diffuse scattering along cubic directions indicates that the regions form in the shape of discs in the various cubic planes. From the width of the diffuse scattering we extract values for a correlation length or size of the regions as a function of temperature. Finally, on the basis of the reciprocal lattice points around which the diffuse scattering is most intense, we conclude that the regions have tetragonal symmetry. The large increase in Bragg intensities at the first-order transition suggests that the polar regions freeze to form large structural domains and the transition is triggered by the percolation of strain fields through the crystals. C1 Lehigh Univ, Dept Phys, Bethlehem, PA 18015 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. CEA Saclay, Leon Brillouin Lab, F-91191 Gif Sur Yvette, France. RP Lehigh Univ, Dept Phys, Bldg 16, Bethlehem, PA 18015 USA. NR 28 TC 25 Z9 25 U1 1 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 2000 VL 62 IS 22 BP 14736 EP 14743 DI 10.1103/PhysRevB.62.14736 PG 8 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800028 ER PT J AU Scala, A Starr, FW La Nave, E Stanley, HE Sciortino, F AF Scala, A Starr, FW La Nave, E Stanley, HE Sciortino, F TI Free energy surface of supercooled water SO PHYSICAL REVIEW E LA English DT Article ID SINGULARITY-FREE INTERPRETATION; LIQUID WATER; SLOW DYNAMICS; BEHAVIOR; PHASE; TRANSITION; COMPRESSIBILITY; THERMODYNAMICS; SIMULATION; LATTICE AB We present a detailed analysis of the free energy surface of a well characterized rigid model for water in supercooled states. We propose a functional form for the liquid free energy, supported by recent theoretical predictions [Y. Rosenfeld and P. Tarazona, Mel. Phys. 95, 141 (1998)], and use it to locate the position of a liquid-liquid critical point at T-C' = 130+/-5 K, P-C' = 290+/-30 MPa, and rho (C') = 1.10+/-0.03 g/cm(3). The observation of the critical point strengthens the possibility that the extended simple point charge model of water may undergo a liquid-liquid phase transition. Finally, we discuss the possibility that the approach to the liquid-liquid critical point could be pre-empted by the glass transition. C1 Boston Univ, Ctr Polymer Studies, Ctr Computat Sci, Boston, MA 02215 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Rome La Sapienza, Ist Nazl Fis Mat, I-00185 Rome, Italy. NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RP Scala, A (reprint author), Boston Univ, Ctr Polymer Studies, Ctr Computat Sci, Boston, MA 02215 USA. RI Sciortino, Francesco/B-4768-2012; Starr, Francis/C-7703-2012; Scala, Antonio/A-2098-2012 OI Scala, Antonio/0000-0002-3414-2686 NR 52 TC 52 Z9 52 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2000 VL 62 IS 6 BP 8016 EP 8020 DI 10.1103/PhysRevE.62.8016 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JM UT WOS:000165879400072 ER PT J AU Sobolewski, MA AF Sobolewski, MA TI Sheath model for radio-frequency-biased, high-density plasmas valid for all omega/omega(i) SO PHYSICAL REVIEW E LA English DT Article ID BOMBARDMENT ENERGY-DISTRIBUTIONS; DRIVEN RF DISCHARGES; PLATE ETCH REACTOR; THAN-OMEGA-I; RADIOFREQUENCY DISCHARGES; ELECTRICAL CHARACTERIZATION; PLANAR DISCHARGES; REFERENCE CELL; DYNAMIC-MODEL; ION CURRENT AB A model is proposed for sheaths in high-density discharges, with radio-frequency (rf) bias applied at frequencies omega comparable to omega (i), the ion plasma frequency at the edge of the sheath. The model treats ion dynamics using fluid equations, including all time-dependent terms. Model predictions for current, impedance, and power were compared to measurements performed in high-density discharges in argon at 1.33 Pa (10 mTorr) at rf bias frequencies from 0.1 to 10 MHz (omega/omega (i) from 0.006 to 1.8) and rf bias voltages from 1 to 200 V. Model predictions were in good agreement with measurements, much better than that obtained by models that neglect time-dependent ion dynamics. In particular, differences of as much as 40-50 % between power measurements and the power predicted by previous models are now explained and eliminated. The model also explains why methods of extracting plasma parameters from electrical measurements using previous sheath models may fail, and it suggests more accurate methods of extracting these parameters. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sobolewski, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 45 TC 52 Z9 52 U1 0 U2 7 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 DEC PY 2000 VL 62 IS 6 BP 8540 EP 8553 DI 10.1103/PhysRevE.62.8540 PN B PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500040 ER PT J AU Wong-Ng, W Kaduk, JA Huang, Q Roth, RS AF Wong-Ng, W Kaduk, JA Huang, Q Roth, RS TI Crystal structure of the monoclinic perovskite Sr(3.94)Ca(1.31)Bi(2.70)O(12) SO POWDER DIFFRACTION LA English DT Article ID POWDER DIFFRACTION PATTERNS; BOND-VALENCE PARAMETERS; PHASE-EQUILIBRIA; SUPERCONDUCTORS; SYSTEM; FIELD AB The crystal structure of the low-temperature oxidized form of Sr(49.5)Ca(16.5)Bi(34)O(151) has been determined using a combination of neutron, synchrotron, and laboratory X-ray powder diffraction data. The structure is pseudo-orthorhombic; systematic absences and successful refinement indicated the true structure to be monoclinic, with space group P2(1)/n. Structural refinement using only neutron powder data yielded the lattice parameters a=8.38 898(29) Angstrom, b=5.99 334(21) Angstrom, c=5.89586(20) Angstrom, beta =89.997(8)degrees and V=296.43(3) Angstrom (3). This compound is a distorted perovskite phase [described in the perovskite ABO(3) formula as ST(Bi(0.7)Ca(0.3))O(3)] With ordering of the M-site cations, resulting in the formula A(2)MM'O(6). In this ordered structure, the A sites are solely occupied by Sr, the M sites mainly by Bi, while on the M' sites Bi and Ca are distributed in an approximate ratio of 2:3. The MO(6) and M'O(6) octahedra share corners, and are tilted with respect to the neighboring layers with an angle of similar to 15 degrees around all three axes. The tilt system symbol is a(+)a(-)a(-) according to Glazer notation. All Pi ions are in the 5(+) oxidation state. (C) 2000 International Centre for Diffraction Data. [S0885-7156(00)00304-3]. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Wong-Ng, W (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 23 TC 4 Z9 4 U1 0 U2 1 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD DEC PY 2000 VL 15 IS 4 BP 227 EP 233 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA 382YJ UT WOS:000165854700005 ER PT J AU Swathi, PS Sharada, MK Yajnik, KS AF Swathi, PS Sharada, MK Yajnik, KS TI A coupled physical-biological-chemical model for the Indian Ocean SO PROCEEDINGS OF THE INDIAN ACADEMY OF SCIENCES-EARTH AND PLANETARY SCIENCES LA English DT Article; Proceedings Paper CT International Symposium on Biogeochemistry of the Arabian Sea CY JAN 18-20, 1999 CL BANGALORE, INDIA DE coupled ocean models; Indian Ocean; carbon flux; marine productivity; JGOFS ID 3-DIMENSIONAL ECOSYSTEM MODEL; MIXED-LAYER PHYSICS; NORTH-ATLANTIC; ARABIAN SEA; EUPHOTIC ZONE; PRODUCTIVITY; VARIABILITY; ADVECTION; DYNAMICS AB A coupled physical-biological-chemical model has been developed at C-MMACS for studying the time-variation of primary productivity and air-sea carbon-dioxide exchange in the Indian Ocean. The physical model is based on the Modular Ocean Model, Version 2 (MOM2) and the biological model describes the nonlinear dynamics of a 7-component marine ecosystem, The chemical model includes dynamical equation for the evolution of dissolved inorganic carbon and total alkalinity, The interaction between the biological and chemical model is through the Redfield ratio, The partial pressure of carbon dioxide (pCO(2)) of the surface layer is obtained from the chemical equilibrium equations of Peng et al 1987. Transfer coefficients for air-sea exchange of CO2 are computed dynamically based on the wind speeds. The coupled model reproduces the high productivity observed in the Arabian Sea off the Somali and Omani coasts during the Southwest (SW) monsoon. The entire Arabian Sea is an outgassing region for CO2 in spite of high productivity with transfer rates as high as 80 m-mol C/m(2)/day during SW monsoon near the Somali Coast on account of strong winds. C1 CSIR, Ctr Math Modelling & Comp Simulat, Bangalore 560037, Karnataka, India. RP Swathi, PS (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, Forrestal Campus,POB CN 710, Princeton, NJ 08544 USA. RI Swathi, P /G-2860-2010; CMMACS, CSIR/A-2491-2011 NR 28 TC 11 Z9 11 U1 1 U2 2 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0253-4126 J9 P INDIAN AS-EARTH JI Proc. Indian Acad. Sci.-Earth Planet. Sci PD DEC PY 2000 VL 109 IS 4 BP 503 EP 537 PG 35 WC Geosciences, Multidisciplinary SC Geology GA 416GT UT WOS:000167772500012 ER PT J AU Chunchuzov, I Vachon, PW Li, X AF Chunchuzov, I Vachon, PW Li, X TI Analysis and modeling of atmospheric gravity waves observed in RADARSAT SAR images SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID MIDDLE ATMOSPHERE; GEOSTROPHIC ADJUSTMENT; NUMERICAL EXPERIMENTS; MU RADAR; PARAMETERIZATION; STRATOSPHERE; VORTEX AB Four case studies of RADARSAT synthetic aperture radar (SAR) observations of atmospheric gravity waves are presented to demonstrate SAR's capability to measure associated near surface wind field variations. A brief review of the main characteristics and scales of atmospheric gravity waves (AGWs) first establishes their importance in atmospheric dynamics. The shape and scale of the wave patterns observed in successive SAR images are compared with those calculated from AGW models. There is agreement between the small-scale wind variations across wave patterns in SAR images and the larger-scale wind field that plays a role in the generation of the observed waves. (C) 2000 Published by Elsevier Science Ireland Ltd. C1 Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. NOAA, Ctr Sci, Camp Springs, MD USA. RP Vachon, PW (reprint author), Canada Ctr Remote Sensing, 588 Booth St, Ottawa, ON K1A OY7, Canada. RI Li, Xiaofeng/B-6524-2008 OI Li, Xiaofeng/0000-0001-7038-5119 NR 61 TC 27 Z9 28 U1 1 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC PY 2000 VL 74 IS 3 BP 343 EP 361 DI 10.1016/S0034-4257(00)00076-6 PG 19 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 387UL UT WOS:000166140200002 ER PT J AU Kogan, FN AF Kogan, FN TI Satellite-observed sensitivity of world land ecosystems to El Nino/La Nina SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID HIGH-RESOLUTION RADIOMETER; DIFFERENCE VEGETATION INDEX; GLOBAL DROUGHT-WATCH; SOUTHERN OSCILLATION; UNITED-STATES; AVHRR DATA; INFRARED CHANNELS; DATA SETS; TEMPERATURE; CALIBRATION AB The recent strong 1997-1998 Nino and the following 1998-1999 La Nina disturbed weather, environment, economy, and human lives worldwide. The total impact of these events (ENSO) on societies is estimated in billions of dollars and consequences include famine, human health problems, loss of life, property damage, and destruction of the environment. Areas sensitive to ENSO have been identified in some world areas from climatic historical records and recently from the normalized difference vegetation index. This paper examines the last 15-year association between monthly sea surface temperature (SST) anomalies in the tropical Pacific and vegetation health (condition) index for the entire world. The vegetation health (condition) index, derived from a combination of Advanced Very High Resolution Radiometer-based normalized difference vegetation index and 10-mum to 11-mum thermal radiances, was designed for monitoring moisture and thermal impacts on vegetation health (greenness and vigor). Two types of responses were identified. In boreal winter, ecosystems of northern South America, southern Africa, and Southeast Asia experienced severe moisture and thermal stress during El Nino and favorable conditions during La Nina years. In Argentina and southwestern United States/Mexico regions, the response was the opposite. World ecosystems are less sensitive to SSTs during boreal summer, except for the areas in northern Brazil and Southeast Asia, where vegetation conditions deteriorate/improve during the warm/cold water cycle in the tropical Pacific. In some areas, ENSO impacts on ecosystems are clearly identified from satellites and not from in situ data (or vice versa). During the boreal winter, these discrepancies occurred in Central America, northern Brazil, and southeastern United States; during the boreal summer, the discrepancies occurred in the sub-Sahara Africa and in the northern part of South America. In the course of the 1997-1999 ENSOs, world vegetation generally responded in accordance with the vegetation health/SST teleconnection patterns. However, in southern Africa, January-March 1998 vegetation stress was not as severe and widespread as in other El Nino years. Similarly, no stress was recorded in Argentina during the 1998-1999 La Nina. (C) Elsevier Science Inc., 2000. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Ctr Sci, Camp Springs, MD 20746 USA. RP Kogan, FN (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Ctr Sci, Room 712,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Kogan, Felix/F-5600-2010 OI Kogan, Felix/0000-0001-8216-900X NR 62 TC 40 Z9 44 U1 7 U2 19 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC PY 2000 VL 74 IS 3 BP 445 EP 462 DI 10.1016/S0034-4257(00)00137-1 PG 18 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 387UL UT WOS:000166140200011 ER PT J AU Clark, AV Hehman, CS Nguyen, TN AF Clark, AV Hehman, CS Nguyen, TN TI Ultrasonic measurement of stress using a rotating EMAT SO RESEARCH IN NONDESTRUCTIVE EVALUATION LA English DT Article ID RESIDUAL-STRESS; PHASE AB The acoustic birefringence method is primarily used to measure differences of principal stresses in regions where principal stresses coincide with material symmetry axes. To determine the differences of principal stresses also requires knowledge of the unstressed birefringence at the measurement locations. Consequently, variability in texture can introduce errors in stress determination. In contrast, the ultrasonic measurement of shear stress is independent of texture. The shear stress causes a rotation phi of the pure-mode polarization directions of the SH waves used in our experiments. We constructed a motorized electromagnetic-acoustic transducer (EMAT) and used it to measure phase as the EMAT is rotated. We developed an algorithm to determine phi and the birefringence B. We measured the shear stress along parallel scanlines in a residual-stress specimen with known stress state. We calculated the shear stress gradient and used it in the stress-equilibrium equation to determine the normal stress acting along the scanline direction. The other plane stress component was determined from an acoustoelastic relation between B and the difference of normal stresses. Good agreement was obtained with theoretical stress values. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RI 苏, 日亮/D-4386-2009 NR 22 TC 2 Z9 3 U1 1 U2 8 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0934-9847 EI 1432-2110 J9 RES NONDESTRUCT EVAL JI Res. Nondestruct. Eval. PD DEC PY 2000 VL 12 IS 4 BP 217 EP 239 DI 10.1080/09349840008968172 PG 23 WC Materials Science, Characterization & Testing SC Materials Science GA 437PL UT WOS:000169002700002 ER PT J AU Brownell, RL Tillman, MF di Sciara, GN Berggren, P Read, AJ AF Brownell, RL Tillman, MF di Sciara, GN Berggren, P Read, AJ TI Further scrutiny of scientific whaling SO SCIENCE LA English DT Letter C1 SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Ist Cent Ric Applicata Mare, I-00166 Rome, Italy. Stockholm Univ, Dept Zool, S-10691 Stockholm, Sweden. Duke Univ, Nicholas Sch Environm, Beaufort, NC 28516 USA. RP Brownell, RL (reprint author), SW Fisheries Sci Ctr, Post Off 271, La Jolla, CA 92038 USA. NR 0 TC 5 Z9 5 U1 4 U2 5 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 DEC 1 PY 2000 VL 290 IS 5497 BP 1696 EP 1696 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 379FY UT WOS:000165632400019 PM 11186389 ER PT J AU Conny, JM Powell, CJ AF Conny, JM Powell, CJ TI Standard test data for estimating peak parameter errors in x-ray photoelectron spectroscopy III. Errors with different curve-fitting approaches SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE XPS; curve fitting; reference data; bias; accuracy; random error; precision; algorithm testing ID LINE-SHAPES; DATA SETS; XPS AB We present results in the final part of a three-part study employing standard test data (STD) to estimate errors in peak parameters derived from data analysis procedures used in x-ray photoelectron spectroscopy (XPS), The XPS-STD are simulated doublet and singlet XPS spectra based on spline polynomial models of measured C 1s spectra, The XPS-STD contained 10 sets of spectra, each of which consisted of 18 doublets and 4 singlets, The doublet spectra in each set were treated from a factorial design with three factors: peak separation; relative intensity of the component peaks; and fractional Poisson noise. Each of the XPS-STD sets contained the same complement of doublet and singlet spectra and Poisson noise at the same levels; however, the noise distributions were unique in each spectral set. Seven curve-fitting approaches were used by a group of 20 analysts to represent single peaks: a single Gaussian (G), a Gaussian-Lorentzian (G-L), a Voigt function, a G function with an asymmetry term, a G-L function with an asymmetry term and dual G or G-L functions. We statistically analyzed errors in binding energies and intensities by the type of curve-fitting approach using the Kruskal-Wallis test and the Mann-Whitney U-test, Bias was used to measure the accuracy of a curve-fitting approach, whereas random error was used to measure the precision of the approach. Despite the fact that individual peaks were nearly symmetrical, curve-fitting approaches that accounted for peak asymmetry proved to be the most accurate for determining both peak intensities and binding energies. For the doublets exhibiting the larger peak at the higher binding energy, the use of dual G-L functions to fit individual peaks, as a way to account for peak asymmetry, produced the highest accuracy in determining peak binding energy. This dual peak-shape approach for this particular spectral condition is also preferable for determining peak intensities and produces better precision. The XPS-STD and the statistical analysis methods presented here provide a means to distinguish differences in the accuracy of various curve-fitting approaches for spectral conditions that resemble those of the XPS-STD, To obtain the XPS-STD and to have an online evaluation of curve-fitting accuracy and precision, consult the following web site: http://www.acg.nist.gov/std. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Conny, JM (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 24 TC 40 Z9 41 U1 2 U2 14 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 DEC PY 2000 VL 29 IS 12 BP 856 EP 872 PG 17 WC Chemistry, Physical SC Chemistry GA 391EG UT WOS:000166340700008 ER PT J AU Coelho, VR Williams, AB Rodrigues, SD AF Coelho, VR Williams, AB Rodrigues, SD TI Trophic strategies and functional morphology of feeding appendages, with emphasis on setae, of Upogebia omissa and Pomatogebia operculata (Decapoda : Thalassinidea : Upogebiidae) SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE shrimp; filter feeder; deposit feeder; pereiopods ID GROOMING BEHAVIOR; CRUSTACEA; ECOLOGY; CLASSIFICATION; MOUTHPARTS; PEREIOPODS; MODES AB Although species of Upogebiidae historically have been considered filter feeders, recent studies show that many species of this group also deposit feed. In this study, the degrees of trophic specialization of two species of this family, Upogebia omissa and Pomatogebia operculata, were analysed. Feeding mechanisms, stomach contents and morphology of the feeding appendages, with emphasis on setae, were examined. U. omissa, found in sandy substrate, is a generalistic feeder while P. operculata inhabits burrows inside corals, being more specialized in filter feeding. Only 21% of the 57 setal types described were common to both species. Setal types were clustered in three main categories: plumed, serrate and plumodenticulate. No simple setae were found. P. operculata has lower setal diversity, with higher ratio of plumodenticulate to serrate setal types than U. omissa. The 1st and 2nd pereiopods have an important role in collecting food. The mouthparts have two main Functions: to brush and retain particles so that food can be transported from the pereiopods to the mouth. Generally in these appendages, the dactyli and basal endites are responsible for brushing particles and the meri and coxal endites for particle retention. The diversity of setal types and complexity of their distribution on the appendages may be related to the necessity to select and triturate particles prior to ingestion, reflecting the differences in trophic strategies utilized by U. omissa and P. operculata. Setal characters appear to be indicators of the relative importance of a specific feeding mode for species of this group. (C) 2000 The Linnean Society or London. C1 Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05422970 Sao Paulo, Brazil. Univ Sao Paulo, Inst Biociencias, Dept Ecol Geral, BR-05422970 Sao Paulo, Brazil. Smithsonian Inst, Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. RP Coelho, VR (reprint author), Columbia Univ, Biosphere 2 Ctr, 32540 Biosphere Rd, Oracle, AZ 85623 USA. NR 45 TC 19 Z9 19 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD DEC PY 2000 VL 130 IS 4 BP 567 EP 602 DI 10.1111/j.1096-3642.2000.tb02202.x PG 36 WC Zoology SC Zoology GA 384LU UT WOS:000165944800006 ER PT J AU Johnson, KTM Graham, DW Rubin, KH Nicolaysen, K Scheirer, DS Forsythe, DW Baker, ET Douglas-Priebe, LM AF Johnson, KTM Graham, DW Rubin, KH Nicolaysen, K Scheirer, DS Forsythe, DW Baker, ET Douglas-Priebe, LM TI Boomerang Seamount: the active expression of the Amsterdam-St. Paul hotspot, Southeast Indian Ridge SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE mantle plumes; hot spots; Southeast Indian Ridge; hydrothermal conditions; Amsterdam Island; Saint Paul Island ID RODRIGUEZ TRIPLE JUNCTION; KERGUELEN PLUME; SEA-FLOOR; BASALTS; OCEAN; GEOCHEMISTRY; ARCHIPELAGO; PLATEAU; SR; ANTARCTICA AB During a survey of the axis of the Southeast Indian Ridge (SEIR), we discovered a 1100 m tall, volcanically active submarine volcano, Boomerang Seamount, near the spreading center on the Amsterdam-St. Paul (ASP) Plateau. The: summit of the volcano is 650 m below sea level and has a 200-m-deep, 2-km-wide circular caldera. Samples of very fresh volcanic glass, dated by the Po-210-Pb-210 technique at similar to5 months old, were collected from the floor of the caldera in March 1996. The volcano is 18 km northeast of Amsterdam Island near the intersection of a long spreading segment and the Boomerang Transform Fault. It is built on the stationary Antarctic Plate, where widely scattered volcanic activity thickens the crust, continuing to build the plateau. Water column profiles reveal a 1.7 degreesC temperature anomaly and a 0.3 V stepped nephelometer (water column turbidity) anomaly within the caldera, nearly an order of magnitude larger than other hydrothermal plume anomalies we measured. These anomalies suggest hydrothermal activity within the caldera. Volcanic glass compositions at two sample sites on the volcano summit are similar to each other and to Amsterdam and St. Paul Island basalts, but have some important differences as well. K2O/TiO2 ratios in Boomerang Seamount glasses are similar to St. Paul Island samples, but differ significantly from Amsterdam Island samples. Rare earth element patterns in lavas from Boomerang, Amsterdam, and St. Paul are similar. Sr, Nd, and Pb isotope ratios in samples from the Boomerang Caldera floor are similar to samples from Amsterdam Island. However, another sample from Boomerang Seamount deviates from a SEIR-St. Paul-Amsterdam mixing trend and shows evidence of mixing with a Kerguelen-like source component. The geochemical complexity of these three closely spaced volcanic edifices on the ASP Plateau suggests that the Boomerang Seamount source is heterogeneous on a very small scale. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Bishop Museum, Dept Geol, Honolulu, HI 96817 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Univ Hawaii, Dept Geol & Geophys, Honolulu, HI 96822 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Johnson, KTM (reprint author), Bishop Museum, Dept Geol, Honolulu, HI 96817 USA. RI Rubin, Kenneth/B-3685-2008 OI Rubin, Kenneth/0000-0002-8554-1337 NR 49 TC 27 Z9 28 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD NOV 30 PY 2000 VL 183 IS 1-2 BP 245 EP 259 DI 10.1016/S0012-821X(00)00279-X PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 377PD UT WOS:000165521200020 ER PT J AU Knight, G Ravishankara, AR Burkholder, JB AF Knight, G Ravishankara, AR Burkholder, JB TI Laboratory studies of OBrO SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO; 298 K; BROMINE DIOXIDES; RATE COEFFICIENT; ANTARCTIC OZONE; SPECTRUM; SYSTEM; BR2O3; OCLO AB UV/vis absorption cross sections for gas phase OBrO at room temperature were measured using a fast gas flow absorption cell and a diode array spectrometer. The OBrO concentration was determined by chemical titration NO + OBrO --> NO2 + BrO (1) with quantitative measurement of the NO2 product by UV absorption. The cross section at the peak of the C (2)A(2) (710) <-- X B-2(1) (000) transition, 491 nm, was determined to be (1.8 +/- 0.5) x 10(-17) cm(2) molecule(-1). During these measurements another gas phase UV absorber was observed to originate from the OBrO source. The possible identity of this species and its influence on the OBrO absorption cross section determination are discussed. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Burkholder, JB (reprint author), NOAA, R-AL2,325 Broadway, Boulder, CO 80305 USA. RI Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 NR 25 TC 16 Z9 16 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 30 PY 2000 VL 104 IS 47 BP 11121 EP 11125 DI 10.1021/jp002226u PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 378TN UT WOS:000165600500016 ER PT J AU Snyder, CR Douglas, JF AF Snyder, CR Douglas, JF TI Determination of the dielectric constant of nanoparticles. 1. Dielectric measurements of buckminsterfullerene solutions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID POROUS-MEDIA; C-60; POLARIZABILITY; FULLERENE; TRANSPORT AB The static dielectric constant epsilon of buckminsterfullerene (C-60) particles is determined in cis-decalin, toluene, and 1,2-dichlorobenzene using continuum models for spherical and spherical shell inclusions. The value for epsilon for isolated C-60 in cis-decalin and toluene agrees well with molecular beam measurements using a spherical shell model, but the epsilon estimate in the highly polar solvent 1,2-dichlorobenzene deviated from these other measurements. Complications of measurements in highly polar solvents are summarized. We conclude that virial measurements have a great potential for determining the effective properties of nanoparticles from the properties of nanofilled materials over a range of dilute filler concentrations. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Snyder, CR (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Snyder, Chad/B-4957-2008 OI Snyder, Chad/0000-0002-2916-9809 NR 47 TC 9 Z9 9 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD NOV 30 PY 2000 VL 104 IS 47 BP 11058 EP 11065 DI 10.1021/jp002024y PG 8 WC Chemistry, Physical SC Chemistry GA 378TP UT WOS:000165600700018 ER PT J AU Raghavan, D VanLandingham, M Gu, X Nguyen, T AF Raghavan, D VanLandingham, M Gu, X Nguyen, T TI Characterization of heterogeneous regions in polymer systems using tapping mode and force mode atomic force microscopy SO LANGMUIR LA English DT Article ID ORGANIC COATINGS; BLOCK-COPOLYMERS; PHASE-DETECTION; FUNCTIONAL-GROUPS; SURFACE; AFM; RESOLUTION; BLENDS; ELECTROLYTE; INDENTATION AB In this study, atomic force microscopy (AFM) is used to investigate the heterogeneity of blenlded films of poly(methyl methacrylate) (PMMA) and polybutadiene (PB) on silicon substrates before and after annealing. The blended films with different ratios of PMMA to PB are prepared by spin casting onto silicon substrates from solution. The surface morphology and composition of these cast films are investigated using tapping mode and force mode AFM. Annealing the samples in air at 75 +/- 5 degreesC causes changes in the relative chemical and mechanical differences between PMMA and PB, so the phase image contrast is studied as a function of annealing time. The effect of tapping force level on phase image contrast is also explored. To identify the different components in polymer blends and to understand the influence of relative surface stiffness on the phase images, nanoscale indentation measurements are made on the observed phase-separated regions. Interpretation of AFM results is aided by data collected from both conditioned and annealed PB and PMMA films using Fourier transform infrared spectroscopy, dynamic mechanical analysis, differential scanning calorimetry, and contact angle measurements. A loss in phase contrast between PB-rich and PMMA-rich regions is observed as a function of heating time. This observation correlates well with the increases in glass transition temperature, modulus, and polarity of pure PB with respect to pure PMMA. C1 Howard Univ, Polymer Sci Div, Dept Chem, Washington, DC 20059 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Howard Univ, Polymer Sci Div, Dept Chem, Washington, DC 20059 USA. EM draghavan@howard.edu NR 63 TC 85 Z9 88 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 28 PY 2000 VL 16 IS 24 BP 9448 EP 9459 DI 10.1021/la991694w PG 12 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 376VR UT WOS:000165477900056 ER PT J AU Meuse, CW AF Meuse, CW TI Infrared spectroscopic ellipsometry of self-assembled mono layers SO LANGMUIR LA English DT Article ID MOLECULAR MONOLAYERS; IR ELLIPSOMETRY; FILMS; GOLD; DEPENDENCE; AU(111) AB Ellipsometry measures the relative intensity of and the phase difference between the parallel and perpendicular components of a polarized electric field vector interacting with a sample. In this paper, a technique using polarized Fourier transform infrared spectroscopy for measuring this information,as the complex optical density function, is presented. The advantage of the complex optical density function is that it, relates the properties of the polarized electric field vector to the supporting surface instead of the plane of incidence. In this configuration, the precise positioning of the sample surface compared to the reference surface and the reproducibility of the analyzer movement are the most important contributions to the errors in the complex optical density function. We demonstrate that these errors are small compared to the complex optical density function measured from the presence of an organic monolayer on a metal surface. The measured complex optical density function provides a signature that is related to both the thickness and molecular structure of the sample layers. Electromagnetic wave theory can be used to predict the signature for any set of sample properties. By matching measurement and prediction, the thicknesses and molecular structures of a series of alkanethiol monolayers are determined. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Meuse, CW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 23 TC 34 Z9 37 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 NOV 28 PY 2000 VL 16 IS 24 BP 9483 EP 9487 DI 10.1021/la000146b PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 376VR UT WOS:000165477900060 ER PT J AU Winans, GA Urawa, S AF Winans, GA Urawa, S TI Allozyme variability of Oncorhynchus nerka in Japan SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE sockeye salmon; allozyme; genetic variability ID SOCKEYE-SALMON; GENETIC-VARIATION; NORTH-AMERICA; HETEROZYGOSITY; POPULATIONS; FITNESS AB We examined allozymic variation in 65 protein-coding loci in three samples of sockeye salmon (Oncorhynchus nerka) from Hokkaido, and Honshu, Japan. Overall, six variable loci were seen and each of the three samples was variable at 3-5 loci. Two loci, mAH-1,2*, and ALAT*, were variable at the P-0.95 level. Average heterozygosity ranged from 0.012 to 0.013, representing some of the lowest recorded values for the species. Although frequencies of ALAT* alleles differed significantly among the three samples. the overall chi (2) for six polymorphic loci was not statistically significant. New data for four Russian samples at 45-64 loci were also obtained. In comparison to the Japanese samples, three samples from the Kamchatka Peninsula had two to three times the level of variation; and a sample from Iturup Island (Kuril Island archipelago) was slightly more variable. Although the anadromous sockeye salmon were originally planted from Iturup Island to Lake Shikotsu, a close genetic affinity was not indicated. These seven samples of O. nerka were compared with representative samples previously studied in North America using five polymorphic loci. Two large groups of samples were indicated in multilocus analyses: 1) a cluster of the seven Asian samples, one Alaskan sample, and one northern British Columbia sample: and 2) a group that included a southern British Columbia sample (Fraser River). and samples from the Columbia River and Washington. We discuss these findings in light of maintaining viable populations of both forms of O. nerka. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. Fisheries Agcy Japan, Natl Salmon Resources Ctr, Toyohira Ku, Sapporo, Hokkaido 0620922, Japan. RP Winans, GA (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 31 TC 5 Z9 5 U1 1 U2 1 PU ICHTHYOLOGICAL SOC JAPAN PI TOKYO PA BUSINESS CENTER ACADEMIC SOC JAPAN, 5-16-9 HONKOMAGOME, BUNKYO-KU, TOKYO, 113, JAPAN SN 1341-8998 J9 ICHTHYOL RES JI Ichthyol. Res. PD NOV 27 PY 2000 VL 47 IS 4 BP 343 EP 352 DI 10.1007/BF02674261 PG 10 WC Zoology SC Zoology GA 403WL UT WOS:000167065400005 ER PT J AU Yienger, JJ Galanter, M Holloway, TA Phadnis, MJ Guttikunda, SK Carmichael, GR Moxim, WJ Levy, H AF Yienger, JJ Galanter, M Holloway, TA Phadnis, MJ Guttikunda, SK Carmichael, GR Moxim, WJ Levy, H TI The episodic nature of air pollution transport from Asia to North America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; GENERAL-CIRCULATION MODEL; PEM-WEST B; TROPOSPHERIC OZONE; MAUNA-LOA; GLOBAL DISTRIBUTION; PACIFIC-OCEAN; ATMOSPHERIC TRANSPORT; UNITED-STATES; EMISSIONS AB We employ the Geophysical Fluid Dynamics Laboratory (GFDL) global chemistry transport model (GCTM) address the episodic nature of trans-Pacific pollution. The strongest Asian CO episodes over North America (NA), occurring most frequently between February and May, are often associated with disturbances that entrain pollution over eastern Asia and amplify over the western Pacific Ocean. Using 55 ppb of Asian CO as a criterion for major events, we find that during a typical year three to five Asian pollution events analogous to those observed by Jaffe et al. [1999] are expected in the boundary layer all along the U.S. West Coast between February and May. Tn contrast to CO, Asia currently has a small impact on the magnitude and variability of background ozone arriving over NA from the west. Direct and indirect Asian contributions to episodic O-3 events over the western United States are generally in the 3 - 10 pphv range. The two largest total O-3 events (>60 pphv), while having trajectories which pass over Asia, show negligible impact from Asian emissions. However, this may change. A future emission scenario, in which Asian NOx emissions increase by a factor of 4 from those in 1990 produces late spring ozone episodes at the surface of California with Asian contributions reaching 40 ppb. Such episodic contributions are certain to exacerbate local NA pollution events, especially in elevated areas more frequently exposed to free tropospheric and more heavily Asian -influenced air. C1 Univ Iowa, CGRER, Iowa City, IA 52242 USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. NOAA, GFDL, Princeton, NJ 08542 USA. RP Yienger, JJ (reprint author), Univ Iowa, CGRER, Iowa City, IA 52242 USA. EM gcarmich@jcaen.uiowa.edu; gl@gfdl.gov RI Hastings, Meredith/C-6199-2008 OI Hastings, Meredith/0000-0001-6716-6783 NR 49 TC 141 Z9 142 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 27 PY 2000 VL 105 IS D22 BP 26931 EP 26945 DI 10.1029/2000JD900309 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 378MY UT WOS:000165589200010 ER PT J AU Pincus, R Klein, SA AF Pincus, R Klein, SA TI Unresolved spatial variability and microphysical process rates in large-scale models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; BOUNDARY-LAYER CLOUDS; HORIZONTAL VARIABILITY; STRATOCUMULUS CLOUDS; CLIMATE MODELS; WATER-CONTENT; SCHEME; PARAMETERIZATION; PRECIPITATION; ALBEDO AB Prognostic cloud schemes in large-scale models are typically formulated in terms of grid-cell average values of cloud condensate concentration q, although variability in q at spatial scales smaller than the grid cell is known to exist. Because the source and sink processes modifying q are nonlinear, the process rates computed using the mean value of q are biased relative to process rates which account for subgrid-scale variability. A preliminary assessment shows that these biases can modify instantaneous process rates by as much as a factor of 2. Observations of q at a continental site suggest that the bias is avoided in current practice through the arbitrary tuning of model parameters. Models might be improved if subgrid-scale variability in q were explicitly considered; several approaches to this goal are suggested. C1 Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. RP Pincus, R (reprint author), Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, 1225 W Dayton St, Madison, WI 53706 USA. EM Robert.Pincus@ssec.wisc.edu; sak@gfdl.gov RI Pincus, Robert/B-1723-2013; Klein, Stephen/H-4337-2016 OI Pincus, Robert/0000-0002-0016-3470; Klein, Stephen/0000-0002-5476-858X NR 26 TC 81 Z9 82 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 NOV 27 PY 2000 VL 105 IS D22 BP 27059 EP 27065 DI 10.1029/2000JD900504 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 378MY UT WOS:000165589200020 ER PT J AU McIntosh, A Lin, P Lucchese, RR Bevan, JW Brugh, DJ Suenram, RD AF McIntosh, A Lin, P Lucchese, RR Bevan, JW Brugh, DJ Suenram, RD TI The microwave spectrum and ground state dynamics of Kr-IH SO CHEMICAL PHYSICS LETTERS LA English DT Article ID INFRARED-SPECTROSCOPY; AB-INITIO; AR-HBR; HCN-HF; COMPLEXES; CLUSTERS; MODEL; HI AB The structure and ground state dynamics of the atom-diatom interaction between Kr and HI has been investigated by pulsed-nozzle Fourier-transform microwave spectroscopy. The ground state of Kr-84-IH is shown to have R-cm = 4.0526(1) Angstrom, theta = 152.87(1)degrees while R-cm = 4.0195(1) Angstrom, theta = 158.85(1)degrees for Kr-84-ID. The potential surface from an ab initio molecular orbital calculation was scaled and shifted to yield a non-linear least-squares fit of the rovibrational state energies to the experimental data. The ground state, Kr-IH isomeric structure is similar to Ar-IH but contrasts with other members of the homologous series Kr-HX (X=F, Cl and Br). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Bevan, JW (reprint author), Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. RI Bevan, John/B-6529-2015; Lucchese, Robert/O-4452-2014; OI Bevan, John/0000-0003-0264-6596; Lucchese, Robert/0000-0002-7200-3775; Lin, Ping/0000-0003-1200-4423 NR 22 TC 11 Z9 11 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 24 PY 2000 VL 331 IS 1 BP 95 EP 100 DI 10.1016/S0009-2614(00)01157-X PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 377LM UT WOS:000165515100016 ER PT J AU Knyazev, VD Tsang, W AF Knyazev, VD Tsang, W TI Chemically and thermally activated decomposition of secondary butyl radical SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID COLLISIONAL ENERGY-TRANSFER; MASTER EQUATION ANALYSIS; CHANNEL UNIMOLECULAR REACTIONS; RATE CONSTANTS; TEMPERATURE-DEPENDENCE; RATE COEFFICIENTS; METHYL RADICALS; MULTIPLE-WELL; DELTA-E; KINETICS AB Experimental literature data on the chemically and thermally activated decomposition of sec-C4H9 radical were analyzed by weak collision master equation modeling. A reaction model with very little flexibility in its properties was created on the basis of ab initio calculations and experimental kinetic and thermochemical data. Rate constants and branching fractions for the:chemically activated reaction were calculated using the virtual component formalism. The resultant model quantitatively describes (1) data on the stabilization-to-decomposition ratios as functions of temperature and pressure obtained in experiments using H + butene reactions as the sources of chemical activation and (2) experimental data on the thermal decomposition bf sec-C4H9 radicals. Values of (DeltaE)(down), the average energy transferred per deactivating collision, derived from modeling of experimental data demonstrate strong positive temperature dependencies for a variety of bath gases. Qualitative shapes of falloff curves for the chemically activated reaction were analyzed. Comparison of the weak collision model with the results of the modified strong collision treatment demonstrates the inadequacy of the latter. C1 Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Knyazev, VD (reprint author), Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. NR 98 TC 42 Z9 42 U1 0 U2 6 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 NOV 23 PY 2000 VL 104 IS 46 BP 10747 EP 10765 DI 10.1021/jp001921z PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 379MR UT WOS:000165646800023 ER PT J AU Werner, RM Stivers, JT AF Werner, RM Stivers, JT TI Kinetic isotope effect studies of the reaction catalyzed by uracil DNA glycosylase: Evidence for an oxocarbenium ion-uracil anion intermediate SO BIOCHEMISTRY LA English DT Article ID TRANSITION-STATE ANALYSIS; ESCHERICHIA-COLI; ADP-RIBOSYLATION; PERTUSSIS TOXIN; HYDROLYSIS; MECHANISM; GLUCOPYRANOSYL; NAD(+); REPAIR; SALTS AB The DNA repair enzyme uracil DNA glycosylase catalyzes the first step in the uracil base excision repair pathway, the hydrolytic cleavage of the N-glycosidic bond of deoxyuridine in DNA. Here we report kinetic isotope effect (KIE) measurements that have allowed the determination of the transition-state structure for this important reaction. The small primary C-13 KIE (=1.010 +/- 0.009) and the large Secondary alpha -deuterium KIE (=1.201 +/- 0.021) indicate that (i) the glycosidic bond is essentially completely broken in the transition state and (ii) there is significant sp(2) character at the anomeric carbon. Large secondary beta -deuterium KIEs were observed when [2'R-H-2] = 1.102 +/- 0.011 and [2'S-H-2] = 1.106 +/- 0.010. The nearly equal and large magnitudes of the two stereospecific beta -deuterium KIEs indicate strong hyperconjugation between the elongated glycosidic bond and both of the C2'-H2' bonds. Geometric interpretation of these beta -deuterium KIEs indicates that the furanose ring adopts a mild 3'-exo sugar pucker in the transition state, as would be expected for maximal stabilization of an oxocarbenium ion. Taken together, these results strongly indicate that the reaction proceeds through a dissociative transition state, with complete dissociation of the uracil anion followed by addition of water. To our knowledge, this is the first transition-state structure determined for enzymatic cleavage of the glycosidic linkage in a pyrimidine deoxyribonucleotide. C1 Univ Maryland, Inst Biol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. RP Stivers, JT (reprint author), Univ Maryland, Inst Biol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. FU NIGMS NIH HHS [R01 GM056834, R01 GM56834] NR 59 TC 110 Z9 111 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 21 PY 2000 VL 39 IS 46 BP 14054 EP 14064 DI 10.1021/bi0018178 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 374QK UT WOS:000165355700006 PM 11087352 ER PT J AU Rye, BJ AF Rye, BJ TI Estimate optimization parameters for incoherent backscatter heterodyne lidar including unknown return signal bandwidth SO APPLIED OPTICS LA English DT Article ID SPECTRAL WIDTH; VELOCITY; POWER AB The conditions for optimizing the precision of heterodyne atmospheric lidar measurements using extended (deep) targets are investigated. The minimum standard deviation of each unknown (return power, Doppler shift, and signal bandwidth) is approximately twice the optical limit at best and is only weakly dependent on knowledge of the other parameters, at optimal power levels. Somewhat stronger signal power levels are needed for bandwidth estimation. Results are displayed as a function of a time-bandwidth product to clarify the trade-off between estimate precision and range weighting. Realization under ideal conditions is confirmed by use of simulations. (C) 2000 Optical Society of America OCIS codes: 010.3640, 040.2840, 280.3340. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80303 USA. RP Rye, BJ (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, R-E-ET2,325 Broadway, Boulder, CO 80303 USA. EM brye@etl.noaa.gov NR 26 TC 3 Z9 3 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 2000 VL 39 IS 33 BP 6086 EP 6096 DI 10.1364/AO.39.006086 PG 11 WC Optics SC Optics GA 372WT UT WOS:000165257600005 PM 18354614 ER PT J AU Liu, WC Houde-Walter, SN Veasey, DL Peskin, AP AF Liu, WC Houde-Walter, SN Veasey, DL Peskin, AP TI Design and optimization of a diode-pumped fiber-coupled Yb : Er glass waveguide laser SO APPLIED OPTICS LA English DT Article ID PHOSPHATE-GLASS; ERBIUM; NM AB An adaptive simulated annealing optimization algorithm is used to derive laser rate equation and waveguiding models with which the best design for a diode-pumped fiber-coupled, Yb:Er glass waveguide laser can be determined. Material parameters that correspond to commercially available laser-glass and diode-pump sources are used in this study. Given a continuous-wave 300-mW pump at 977 nm, approximately 48 mW of power at 1540 nn can be coupled into the LP01 mode of an optical fiber. Fabrication and alignment tolerance analyses are presented. (C) 2000 Optical Society of America OCIS codes: 140.3500, 130.3120, 220.4830, 136.2790, 140.5680. C1 Univ Rochester, Rochester, NY 14627 USA. Rochester Theory Ctr Opt Sci & Engn, Rochester, NY USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Liu, WC (reprint author), Natl Taiwan Normal Univ, Dept Phys, Taipei 106, Taiwan. EM shw@optics.rochester.edu NR 16 TC 1 Z9 3 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 2000 VL 39 IS 33 BP 6165 EP 6173 DI 10.1364/AO.39.006165 PG 9 WC Optics SC Optics GA 372WT UT WOS:000165257600015 PM 18354624 ER PT J AU Penton, SV Shull, JM Stocke, JT AF Penton, SV Shull, JM Stocke, JT TI The local Ly alpha forest. II. Distribution of HI absorbers, Doppler widths, and baryon content SO ASTROPHYSICAL JOURNAL LA English DT Article DE intergalactic medium; quasars : absorption lines; ultraviolet : galaxies ID HIGH-RESOLUTION SPECTROGRAPH; LINE KEY PROJECT; INTERGALACTIC HYDROGEN CLOUDS; LOW-REDSHIFT; ABSORPTION SYSTEMS; METAL ENRICHMENT; GALACTIC HALO; QUASAR; EVOLUTION; SPECTRUM AB In Paper I of this series we described observations of 15 extragalactic targets taken with the Hubble Space Telescope+ GHRS + G160M grating for studies of the low-z Ly alpha forest. We reported the detection of 111 Ly alpha absorbers at significance level (SL) greater than or equal to3 sigma, 81 with SL greater than or equal to 4 sigma, in the redshift range 0.002 < z < 0.069, over a total path length c Deltaz = 116,000 km s(-1) (Deltaz = 0.387). In this second paper, we evaluate the physical properties of these Lya absorbers and compare them to their high-z counterparts. The SL greater than or equal to 4 a distribution of Doppler parameters is similar to that at high redshift, with = 38.0 +/- 15.7 km s(-1). The true Doppler parameter may be somewhat lower, owing to component blends and nonthermal velocities. The distribution of equivalent widths exhibits a significant break at W less than or equal to 133 m Angstrom, with an increasing number of weak absorbers (10 m Angstrom < W < 100 m Angstrom). Adopting a curve of growth with b = 25 +/- 5 km s(-1) and applying a sensitivity correction as a function of equivalent width and wavelength, we derive the distribution in column density, N-HI(-1.72+/-0.06) for 12.5 less than or equal to log [N-HI] less than or equal to 14.0. We find no redshift evolution within the current sample at z < 0.07, but we do see a significant decline in d N /dz compared to values at z > 1.6. Similar to the high equivalent width (W > 240 m Angstrom) absorbers, the number density of low-W absorbers at z = 0 is well above the extrapolation of d N /dz from z > 2, but we observe no difference in the mean evolution of dN/dz between absorbers of high (W > 240 m Angstrom) and low (W less than or equal to 100 m Angstrom) equivalent width. While previous work has suggested slower evolution in number density of lower W absorbers, our new data do not support this conclusion. A consistent evolutionary pattern is that the slowing in the evolution of the low column density clouds occurs at lower redshift than for the higher column density clouds. A 4-5 a signal in the two-point correlation function of Ly alpha absorbers for velocity separations Deltav less than or equal to 150 km s(-1) is consistent with results at high z, but with somewhat greater amplitude. Applying a photoionization correction, we find that the low-z Ly alpha forest may contain similar to 20% of the total number of baryons, with closure parameter OmegaL(y alpha) = (0.008 +/- 0.001)h(70)(-1), for a standard absorber size and ionizing radiation held. Some of these clouds appear to be primordial matter, owing to the lack of detected metals (Si III) in a composite spectrum, although current limits on composite metallicity are not strong. 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, Boulder, CO 80309 USA. NR 78 TC 119 Z9 120 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 150 EP 175 DI 10.1086/317179 PN 1 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300015 ER PT J AU Christov, IP Kapteyn, HC Murnane, MM AF Christov, IP Kapteyn, HC Murnane, MM TI Quasi-phase matching of high-harmonics and attosecond pulses in modulated waveguides SO OPTICS EXPRESS LA English DT Article ID HOLLOW-CORE FIBER; SOFT X-RAYS; LASER-PULSES; GENERATION AB We describe theoretically a new technique for quasi-phase-matched generation of high harmonics and attosecond pulses in a gas medium, in a high ionization limit. A corrugated hollow-core fiber modulates the intensity of the fundamental pulse along the direction of propagation, resulting in a periodic modulation of the harmonic emission at wavelengths close to the cutoff. This leads to an increase of the harmonic yield of up to three orders of magnitude. At the same time the highest harmonics merge in a broad band that corresponds to a single attosecond pulse, using 15-fs driving pulses. (C) 2000 Optical Society of America. C1 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. RP Christov, IP (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Kapteyn, Henry/H-6559-2011; Christov, Ivan/D-4446-2014 OI Kapteyn, Henry/0000-0001-8386-6317; Christov, Ivan/0000-0002-9146-6708 NR 19 TC 65 Z9 65 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD NOV 20 PY 2000 VL 7 IS 11 BP 362 EP 367 PG 6 WC Optics SC Optics GA 375HF UT WOS:000165392900001 PM 19407887 ER PT J AU Shaw, JA Marston, C AF Shaw, JA Marston, C TI Polarized infrared emissivity for a rough water surface SO OPTICS EXPRESS LA English DT Article ID SEA-SURFACE AB The polarization state of infrared emission from water at large viewing angles is explained mathematically by a polarization-dependent emissivity. To provide polarized emissivity values for a wind-roughened water surface in a convenient format, this electronic paper provides interactive tables and plots of polarized water emissivity for the spectral range of 3-15 mum. The rough surface is modeled as a collection of specular facets with slopes given by a Gaussian distribution. The interactive electronic format provides a tutorial on emission polarization and it allows readers to copy the desired numbers and paste them into their electronic applications without the difficulty of transcribing numbers from printed tables. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Shaw, JA (reprint author), NOAA, Environm Technol Lab, Boulder, CO 80305 USA. NR 14 TC 22 Z9 22 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD NOV 20 PY 2000 VL 7 IS 11 BP 375 EP 380 PG 6 WC Optics SC Optics GA 375HF UT WOS:000165392900003 PM 19407889 ER PT J AU Fatemi, FK Jones, KM Lett, PD AF Fatemi, FK Jones, KM Lett, PD TI Observation of optically induced Feshbach resonances in collisions of cold atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATE; SCATTERING LENGTH; LIGHT; FIELD; PHOTOASSOCIATION; SPECTROSCOPY; SUPPRESSION; TIME AB We have observed optically induced Feshbach resonances in a cold (<1 mK) sodium vapor. The optical coupling of the ground and excited-state potentials changes the scattering properties of an ultracold gas in much the same way as recently observed magnetically induced Feshbach resonances, but allows for some experimental conveniences associated with using lasers. The scattering properties can be varied by changing either the intensity or the detuning of a laser tuned near a photoassociation transition to a molecular state in the dimer. In principle this method allows the scattering length of any atomic species to be altered. A simple model is used to fit the dispersive resonance line shapes. C1 NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. Williams Coll, Dept Phys, Williamstown, MA 01267 USA. RP Fatemi, FK (reprint author), NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. NR 24 TC 140 Z9 140 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 20 PY 2000 VL 85 IS 21 BP 4462 EP 4465 DI 10.1103/PhysRevLett.85.4462 PG 4 WC Physics, Multidisciplinary SC Physics GA 375KU UT WOS:000165399000013 ER PT J AU Bousquet, P Peylin, P Ciais, P Le Quere, C Friedlingstein, P Tans, PP AF Bousquet, P Peylin, P Ciais, P Le Quere, C Friedlingstein, P Tans, PP TI Regional changes in carbon dioxide fluxes of land and oceans since 1980 SO SCIENCE LA English DT Article ID ATMOSPHERIC CO2; EL-NINO; EQUATORIAL PACIFIC; SINK; VARIABILITY; CYCLE AB We have applied an inverse model to 20 years of atmospheric carbon dioxide measurements to infer yearly changes in the regional carbon balance of oceans and continents. The model indicates that global terrestrial carbon fluxes were approximately twice as variable as ocean fluxes between 1980 and 1998, Tropical Land ecosystems contributed most of the interannual changes in Earth's carbon balance over the 1980s, whereas northern mid- and high-latitude Land ecosystems dominated from 1990 to 1995, Strongly enhanced uptake of carbon was found over North America during the 1992-1993 period compared to 1989-1990. C1 Lab Sci Climat Environm, F-91198 Gif Sur Yvette, France. Univ Versailles St Quentin Yvelines, F-78035 Versailles, France. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Bousquet, P (reprint author), Lab Sci Climat Environm, F-91198 Gif Sur Yvette, France. RI Vuichard, Nicolas/A-6629-2011; Friedlingstein, Pierre/H-2700-2014; Le Quere, Corinne/C-2631-2017 OI Le Quere, Corinne/0000-0003-2319-0452 NR 26 TC 448 Z9 483 U1 11 U2 59 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 NOV 17 PY 2000 VL 290 IS 5495 BP 1342 EP 1346 DI 10.1126/science.290.5495.1342 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 375BN UT WOS:000165379800045 PM 11082059 ER PT J AU Ryerson, TB Williams, EJ Fehsenfeld, FC AF Ryerson, TB Williams, EJ Fehsenfeld, FC TI An efficient photolysis system for fast-response NO2 measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INDUCED FLUORESCENCE DETECTION; POWER-PLANT PLUMES; NORTH-ATLANTIC; LOWER STRATOSPHERE; NITROGEN-OXIDES; NITRIC-ACID; PEM-TROPICS; OZONE; AIRCRAFT; PHOTOCHEMISTRY AB A new photolytic converter for NO2 measurement is described and its performance assessed using laboratory, ground-, and aircraft-based field data. Focusing the output of a 200-W short-are Hg lamp into a photolytic cell attains conversion fractions of NO2 to NO greater than 0.70 in cell residence times of less than a second. Limiting lamp output to wavelengths greater than 350 nm by means of optical filters increases specificity for NO2, affording a peroxyacetyl nitrate conversion fraction of less than 0.006 and negligible conversion of HNO3. Unwanted (artifact) signal in clean synthetic air is also greatly minimized through the use of optical filters. Fast instrument response is achieved by minimizing NO2 inlet line and photolysis cell residence times, NO and NO2 sample residence times are matched in a multichannel instrument so that signal from ambient NO may be easily subtracted from the total signal and ambient NO2 calculated by difference at high time resolution. Induced change in the ambient ratio of NO to NO2, due to reaction of ozone and other oxidants with NO during sampling, is minimized in the new design. This configuration permits simple and accurate retrieval of NO2 concentrations in aircraft transects of power plant plumes, where ambient NO concentrations can change over several orders of magnitude in seconds. at lower concentrations found in the planetary boundary layer, agreement between calculated and observed NO2 is within +/-(40 pptv + 7%) for a 10-s average. The new converter consumes less power, is more efficient, and is less expensive to operate than previous photolysis designs. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ryerson, TB (reprint author), NOAA, Aeron Lab, 325 Broadway,R-AL 7, Boulder, CO 80303 USA. EM tryerson@al.noaa.gov RI Williams, Eric/F-1184-2010; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013 NR 39 TC 150 Z9 155 U1 0 U2 27 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 16 PY 2000 VL 105 IS D21 BP 26447 EP 26461 DI 10.1029/2000JD900389 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375VH UT WOS:000165421600008 ER PT J AU Brock, CA Schroder, F Karcher, B Petzold, A Busen, R Fiebig, M AF Brock, CA Schroder, F Karcher, B Petzold, A Busen, R Fiebig, M TI Ultrafine particle size distributions measured in aircraft exhaust plumes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CONDENSATION NUCLEUS COUNTER; IN-SITU OBSERVATIONS; FUEL SULFUR-CONTENT; AEROSOL-PARTICLES; AIRBORNE OBSERVATIONS; CONTRAIL FORMATION; TWOMEY ALGORITHM; EMISSION INDEXES; ENGINE; CRUISE AB Fast-response measurements of particle size distributions were made for the first time in the near-field plume of a Boeing 737-300 aircraft burning fuel with fuel sulfur (S) contents (FSCs) of 56 and 2.6 ppmm, as well as in fresh and dissipating contrails from the same aircraft, using nine particle counters operating in parallel. Nonsoot particles were present in high concentrations, with number maxima at diameters less than or equal to3 nm. From these and ancillary measurements we determined the apparent emission index, EI*, or amount produced per kilogram of fuel burned, for particle number, surface, and volume, and the value of eta*, the apparent fraction of fuel S found in the particulate phase in the plume assuming the particles were composed of sulfuric acid and water. All of these parameters were functions of the age of the plume since emission, FSC, and presence or absence of contrail. The measurements support the use of values of eta* of <10% in numerical models of the effects of the current aircraft fleet on the atmosphere, suggest that non-S species become important contributors to particulate mass at very low FSCs, and place significant constraints on numerical models of plume microphysical processes. C1 Univ Denver, Dept Engn, Denver, CO 80208 USA. Deutsch Luft & Raumfahrt, Inst Phys Atmosphare, Wessling, Germany. NOAA, Aeron Lab, Boulder, CO USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Brock, CA (reprint author), Univ Denver, Dept Engn, Denver, CO 80208 USA. EM cbrock@al.noaa.gov; franz.schroeder@dlr.de; bernd.kaercher@dlr.de; andreas.petzold@dlr.de; reinhold.busen@dlr.de; markus.fiebig@dlr.de RI Brock, Charles/G-3406-2011; Fiebig, Markus/I-4872-2012; Petzold, Andreas/J-2347-2012; Karcher, Bernd/D-5325-2014 OI Brock, Charles/0000-0002-4033-4668; Fiebig, Markus/0000-0002-3380-3470; Petzold, Andreas/0000-0002-2504-1680; Karcher, Bernd/0000-0003-0278-4980 NR 47 TC 81 Z9 82 U1 2 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 16 PY 2000 VL 105 IS D21 BP 26555 EP 26567 DI 10.1029/2000JD900360 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375VH UT WOS:000165421600016 ER PT J AU Pomeroy, JW Li, L AF Pomeroy, JW Li, L TI Prairie and arctic areal snow cover mass balance using a blowing snow model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; COMPLEX TERRAIN; WIND-SPEED; TRANSPORT; SUBLIMATION; SALTATION; THRESHOLD; PROFILES AB Algorithms to calculate the threshold wind speed and the effect of exposed vegetation on saltation and to describe vertical profiles of humidity in blowing snow, permit the calculation of point blowing snow transport and sublimation fluxes using standard meteorological and landcover data or simple interfaces with climate models. Blowing snow transport and sublimation fluxes can be upscaled to calculate open environment snow accumulation by accounting for their variability over open snow fields, increase in transport and sublimation with fetch, and the effect of exposed vegetation on partitioning the shear stress available to drive transport. Blowing snow fluxes scaled in this manner were used to calculate snow mass balance and to simulate seasonal snow accumulation at a southern Saskatchewan prairie and an arctic site. Field measurements at these sites indicated that from 48% to 58% of snowfall was removed by blowing snow before melt began. Simulations suggest that the ratios of snow removed and sublimated by blowing snow to that transported were 2:1 and 1:1 at the prairie and arctic sites respectively. The resulting methodology was capable of estimating winter season mass balances for these snowpacks that compared well with snowfall and snow accumulation measurements. C1 Univ Wales, Inst Geog & Earth Sci, Ctr Glaciol, Aberystwyth SY23 3DB, Dyfed, Wales. NOAA, Natl Operat Hydrol Remote Sensing Ctr, Off Hydrol, Chanhassen, MN 55317 USA. RP Pomeroy, JW (reprint author), Univ Wales, Inst Geog & Earth Sci, Ctr Glaciol, Aberystwyth SY23 3DB, Dyfed, Wales. EM wpp@aber.ac.uk; li@nohrsc.nws.gov RI Pomeroy, John/A-8589-2013 OI Pomeroy, John/0000-0002-4782-7457 NR 48 TC 68 Z9 71 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 16 PY 2000 VL 105 IS D21 BP 26619 EP 26634 DI 10.1029/2000JD900149 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375VH UT WOS:000165421600022 ER PT J AU Srinivasan, G Robock, A Entin, JK Luo, LF Vinnikov, KY Viterbo, P AF Srinivasan, G Robock, A Entin, JK Luo, LF Vinnikov, KY Viterbo, P CA AMIP Modeling Grp TI Soil moisture simulations in revised AMIP models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SURFACE PARAMETERIZATION SCHEMES; ASIAN SUMMER MONSOON; INTERANNUAL VARIABILITY; ECMWF REANALYSIS; INTERCOMPARISON PROJECT; WETNESS PROJECT; WATER-BALANCE; LAND; CLIMATE; PRECIPITATION AB Soil moisture is important both in its influence on climate and for assessing impacts of future climate change. It is therefore necessary to simulate it correctly in global climate models. We have used the revisit simulations contributed by six of the Atmospheric Model Intercomparison Project 1 participating modeling groups to examine the impacts of model revisions, particularly the land surface representations, on soil moisture simulations, by comparing the simulations to actual soil moisture observations. The revised models do not show any systematic improvement in their ability to simulate observed seasonal variations of soil moisture over the regions studied. Many of the revised models continue to have a strong tendency toward dry soil conditions during Northern Hemisphere summer months, both globally and regionally. There are no indications of conceptually more realistic land surface representations producing better soil moisture simulations in the revised climate models. As the revised models continue to produce incorrect simulations of the seasonal cycle of regional precipitation, it is not possible to isolate the effect of land surface schemes on the simulations. The European Centre for Medium Range Weather Forecasts and National Centers for Environmental Prediction/National Center for Atmospheric Research reanalyses, however, which are driven by observed precipitation, do capture some of the observed interannual variability of soil moisture over Illinois. C1 Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. Indian Meteorol Dept, Reg Meteorol Ctr, Bombay 400005, Maharashtra, India. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Raytheon ITSS, Greenbelt, MD 20771 USA. Bur Meteorol Res Ctr, Melbourne, Vic, Australia. Ctr Natl Rech Meteorol, Toulouse, France. Dept Numer Math, Moscow, Russia. Geophys Fluid Dynam Lab, Princeton, NJ USA. Meteorol Dynam Lab, Paris, France. Yonsei Univ, Seoul 120749, South Korea. RP Srinivasan, G (reprint author), Rutgers State Univ, Dept Environm Sci, 14 Coll Farm Rd, New Brunswick, NJ 08901 USA. EM sriniren@vsnl.com; robock@envsci.rutgers.edu; jentin@dao.gsfc.nasa.gov; luo@envsci.rutgers.edu; kostya@atmos.umd.edu; p.viterbo@ecmwf.int RI Luo, Lifeng/C-8734-2009; Vinnikov, Konstantin/F-9348-2010; Viterbo, Pedro/B-7184-2008; Robock, Alan/B-6385-2016; OI Viterbo, Pedro/0000-0001-6587-3062; Robock, Alan/0000-0002-6319-5656 NR 43 TC 27 Z9 27 U1 0 U2 4 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 NOV 16 PY 2000 VL 105 IS D21 BP 26635 EP 26644 DI 10.1029/2000JD900443 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375VH UT WOS:000165421600023 ER PT J AU Reid, JP Loomis, RA Leone, SR AF Reid, JP Loomis, RA Leone, SR TI Competition between N-H and N-D bond cleavage in the photodissociation of NH2D and ND2H SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID STATE AMMONIA MOLECULES; ULTRAVIOLET-ABSORPTION SPECTRUM; EXTENDED CROSS-CORRELATION; OPTICAL DOUBLE-RESONANCE; JET-COOLED AMMONIA; (A)OVER-TILDE STATE; DYNAMICS; NH3; EMISSION; DISSOCIATION AB The adiabatic dissociation dynamics of NH2D((A) over tilde) and ND2H((A) over tilde) have been probed by time-resolved Fourier transform infrared emission spectroscopy. A product-state spectral pattern recognition technique is employed to separate out the emission features arising from the different photofragmentation channels following the simultaneous excitation of mixtures of the four parent molecules NH3, NH2D, ND2H, and ND3 at 193.3 nm. The rotational energy partitioning about the primary a-axis of the fragments NH2((A) over tilde ,v(2)' = 0) and ND2((A) over tilde ,v(2)' = 0) from NH2D(A) and ND2H((A) over tilde), respectively, is bimodal. We suggest that the origin of this excitation reflects the competition between two distinct dissociation mechanisms that sample two different geometries during the bond cleavage. A larger quantum yield for producing ND2((A) over tilde ,v(2)' = 0) from the photodissociation of ND2H than ND3 is attributed to the lower dissociation energy of the N-H as compared with the N-D bond and to the enhanced tunneling efficiency of H atoms over D atoms through the barrier to dissociation. Similarly, the quantum yield for producing the NH2((A) over tilde ,v(2)' = 0) fragment is lower when an N-D bond must be cleaved in comparison to an N-H bond. Photodissociation of ND2H by cleavage of an N-H bond leads to an ND2((A) over tilde) fragment with a much larger degree of vibrational excitation (v(2)' = 1,2), accompanied by substantial rotation about the minor b/c-axes, than when an N-D bond is cleaved in the photodissociation of ND3. The quantum yield for producing NHD((A) over tilde) is larger for cleavage of an N-H bond from NH2D than by cleavage of an N-D from ND2H. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Biochem & Chem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, 325 Broadway, Boulder, CO 80309 USA. RI Reid, Jonathan/D-9411-2013 NR 35 TC 27 Z9 27 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 16 PY 2000 VL 104 IS 45 BP 10139 EP 10149 DI 10.1021/jp001065r PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 374QG UT WOS:000165355400011 ER PT J AU Lovejoy, ER Bianco, R AF Lovejoy, ER Bianco, R TI Temperature dependence of cluster ion decomposition in a quadrupole ion trap SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PROTONATED WATER CLUSTERS; INFRARED RADIATIVE DISSOCIATION; THERMAL UNIMOLECULAR REACTIONS; GAS-PHASE; ISOMERIC CLUSTERS; BINDING-ENERGIES; DIMETHYL ETHER; HYDROGEN-BONDS; NEGATIVE IONS; LOW-PRESSURES AB Rate coefficients for the thermal decomposition of H+(H2O)(3,4), H+(CH3OH)(3), H+(C2H5OH)(2), H+(CH3CN)(2), H+((CH3)(2)CO)(2), NO3-(HNO3)(1,2), and Cl-H2O are measured as a function of temperature in a quadrupole ion trap over the pressure range 0.2-2 mTorr of He. The kinetics are in the low pressure limit and the decomposition activation energies are significantly less than the bond energies. The difference between the bond energy and the activation energy is reproduced by theory. The vibrational frequencies of the cluster ions necessary for the theoretical treatment of the dissociation rate constants are calculated ab initio at the HF/6-31G* level. This work demonstrates that cluster ion bond energies may be determined accurately from activation energies for dissociation at the low-pressure limit. The measurements also yield fundamental information about the intermolecular energy transfer between the helium buffer gas and the cluster ions. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Lovejoy, ER (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. NR 74 TC 19 Z9 19 U1 1 U2 8 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 NOV 16 PY 2000 VL 104 IS 45 BP 10280 EP 10287 DI 10.1021/jp001216q PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 374QG UT WOS:000165355400029 ER PT J AU Harder, H Bosch, H Camy-Peyret, C Chipperfield, MP Fitzenberger, R Payan, S Perner, D Platt, U Sinnhuber, BM Pfeilsticker, K AF Harder, H Bosch, H Camy-Peyret, C Chipperfield, MP Fitzenberger, R Payan, S Perner, D Platt, U Sinnhuber, BM Pfeilsticker, K TI Comparison of measured and modeled stratospheric BrO: Implications for the total amount of stratospheric bromine SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DIFFERENT LATITUDES; SEASONS AB Stratospheric BrO was spectroscopically monitored by its UV absorption in direct sunlight on 8 balloon flights that were conducted at middle and high latitudes in 1996 through 2000 [e.g., Ferlemann et al., 1998, 2000]. For conditions where detailed photochemical model calculations [Chipperfield, 1999] correctly predict other measured chemical (e.g., NO2, O-3) and dynamical (e.g. N2O, F12, et cetera) tracers, the total stratospheric bromine (organic and inorganic) amount (Br,) is inferred. An excellent agreement between measured and modeled stratospheric BrO is found, assuming JPL-97 kinetics and Br-y=20 ppt in the photochemical model. As the BrO absorption cross section (sigma (BrO)) is the only external parameter used in the measurement, our finding tightly constrains the amount of total inorganic bromine (Br-y(in)), 20+/-2.5 ppt above 25 km in 1996/97, as well as the photochemistry of stratospheric bromine. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. Max Planck Inst Chem, D-55128 Mainz, Germany. Univ Paris 06, CNRS, LPMA, Paris, France. Univ Leeds, Sch Environm, Leeds, W Yorkshire, England. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Harder, H (reprint author), Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. EM harder@essc.psu.edu 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 15 TC 27 Z9 27 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 NOV 15 PY 2000 VL 27 IS 22 BP 3695 EP 3698 DI 10.1029/1999GL011215 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 375TW UT WOS:000165418200023 ER PT J AU Smith, CA Sardeshmukh, PD AF Smith, CA Sardeshmukh, PD TI The effect of ENSO on the intraseasonal variance of surface temperatures in winter SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE ENSO; temperature; intraseasonal variance; probability; Pacific-North American sector ID UNITED-STATES; VARIABILITY; CIRCULATION; PATTERNS; ANOMALIES; EXTREMES; FLORIDA; EVENTS; MODEL AB The effect of the El Nino-Southern Oscillation (ENSO) on the probability distribution of daily surface air temperature over the Pacific-North American sector is investigated using the US National Centers for Environmental Prediction (NCEP) Reanalysis data for 1959-1998. The El Nino response is characterized by reduced intraseasonal variance over most of the US, western Canada and the Gulf of Alaska. Conversely, there is an increase of variance during La Nino over the US and the west coast, northward to Alaska. The sign of this response is consistent for most individual El Nino/La Nina years in regions with a strong signal. The response is also robust with respect to differing definitions of ENSO or choice of dataset. Finally, a similar response is evident in station data for an earlier period. The change of variance is associated both with altered skewness, and a change in high and low extremes. Extremes of both signs are reduced during El Nino, and are slightly increased during La Nina. These results are consistent with other studies, suggesting an increased incidence of blocking along the west coast of North America during El Nino, leading to less storm activity and less incursions of warm and cold air over the eastern US. While an understanding of the changed variance is important in itself, it also has implications for changes in exceedence statistics (e.g. heating degree days) and the occurrence of extreme values. Copyright (C) 2000 Royal Meteorological Society. C1 Univ Colorado, NOAA, CIRES, Climate Diagnost Ctr,R CDC, Boulder, CO 80305 USA. RP Smith, CA (reprint author), Univ Colorado, NOAA, CIRES, Climate Diagnost Ctr,R CDC, 325 Broadway, Boulder, CO 80305 USA. EM cas@cdc.noaa.gov RI Smith, Catherine/H-5055-2016 OI Smith, Catherine/0000-0003-2687-6046 NR 25 TC 108 Z9 109 U1 2 U2 17 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV 15 PY 2000 VL 20 IS 13 BP 1543 EP 1557 DI 10.1002/1097-0088(20001115)20:13<1543::AID-JOC579>3.0.CO;2-A PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 376EP UT WOS:000165445500003 ER PT J AU Wang, YC Misakian, M Goyette, AN Olthoff, JK AF Wang, YC Misakian, M Goyette, AN Olthoff, JK TI Ion fluxes and energies in inductively coupled radio-frequency discharges containing CHF3 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HIGH-DENSITY PLASMAS; RF REFERENCE CELL; ELECTRON INTERACTIONS; FLUOROCARBON PLASMAS; CF4; ARGON; SIMULATIONS; C2F6 AB Measurements of ion energy distributions, relative ion intensities, and absolute total ion current densities were made at the grounded electrode of an inductively coupled Gaseous Electronics Conference (GEC) radio-frequency reference cell for discharges generated in CHF3 and its mixtures with argon. In general, the dominant ion species detected were not due to direct ionization of the CHF3 feed gas. Results are presented for plasmas generated with and without a confining quartz annulus that has recently been used to extend the operating parameter range of inductively coupled GEC cells for certain etching gases. Compared to similar plasmas generated without the annulus, the presence of the ring increases the ion flux density by approximately a factor of 2, and increases the mean ion energies. The presence of the ring does not significantly affect the measured relative ion intensities. [S0021-8979(00)04123-2]. C1 Natl Inst Stand & Technol, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Wang, YC (reprint author), Natl Inst Stand & Technol, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. NR 24 TC 11 Z9 12 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 NOV 15 PY 2000 VL 88 IS 10 BP 5612 EP 5617 DI 10.1063/1.1319968 PG 6 WC Physics, Applied SC Physics GA 369MA UT WOS:000165068700014 ER PT J AU Gerardin, O Ben Youssef, J Le Gall, H Vukadinovic, N Jacquart, PM Donahue, MJ AF Gerardin, O Ben Youssef, J Le Gall, H Vukadinovic, N Jacquart, PM Donahue, MJ TI Micromagnetics of the dynamic susceptibility for coupled Permalloy stripes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS AB The dynamic susceptibility of arrays of narrow Permalloy stripes (9 mm x several mum x 200 nm) has been investigated using a single-coil broadband susceptibility spectrometer. Disagreement is observed between experimental results and the macroscopic Landau-Lifshitz model. This model does not take into account the dipolar interaction between magnetic stripes. We have performed micromagnetic calculations that include these dipolar interactions, and have found the resulting frequency dependence of the dynamic susceptibility in the linear regime to be in good agreement with our experimental data. (C) 2000 American Institute of Physics. [S0021-8979(00)03723-3]. C1 Univ Brest, CNRS, UMR 6135, Lab Magnetisme Bretagne, F-29285 Brest, France. Dassault Aviat, F-92552 St Cloud, France. NIST, Gaithersburg, MD 20899 USA. RP Gerardin, O (reprint author), Univ Brest, CNRS, UMR 6135, Lab Magnetisme Bretagne, F-29285 Brest, France. NR 11 TC 27 Z9 27 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 NOV 15 PY 2000 VL 88 IS 10 BP 5899 EP 5903 PG 5 WC Physics, Applied SC Physics GA 369MA UT WOS:000165068700060 ER PT J AU Davico, GE Ramond, TM Lineberger, WC AF Davico, GE Ramond, TM Lineberger, WC TI Photoelectron spectroscopy of SnO- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID ULTRAVIOLET REGION; PBO; SPECTRUM; OXIDES; TIN C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Lineberger, WC (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM wcl@jila.colorado.edu NR 22 TC 5 Z9 5 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 15 PY 2000 VL 113 IS 19 BP 8852 EP 8853 AR PII [S0021-9606(00)00343-3] DI 10.1063/1.1318194 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 369TR UT WOS:000165083500054 ER PT J AU Higgins, RW Leetmaa, A Xue, Y Barnston, A AF Higgins, RW Leetmaa, A Xue, Y Barnston, A TI Dominant factors influencing the seasonal predictability of US precipitation and surface air temperature SO JOURNAL OF CLIMATE LA English DT Article ID NORTH-ATLANTIC OSCILLATION; EL-NINO; VARIABILITY; CLIMATE; PACIFIC; ATMOSPHERE; FORECASTS; PATTERNS; DECADES; FIELDS AB The relative contributions of El Nino-Southern Oscillation (ENSO), long-term tropical Pacific variations, and the Arctic oscillation (AO) to the explained variance of U.S. precipitation and surface air temperature are investigated. The time variability of monthly precipitation in the tropical pacific basin is separated into high-pass and low-pass filtered components. The leading EOFs of the high-pass and low-pass filtered data capture ENSO cycle-related interannual variability and ENSO-like interdecadal variability, respectively. The dominant mode of variability in the extratropics is the AO, which has been implicated in some of the secular variability of climate in the Northern Hemisphere extratropics. ENSO produces large, reasonably reproducible spatial and temporal shifts in tropical precipitation. The tropical interdecadal variability produces more subtle, but still significant, shifts in tropical precipitation that contribute significantly to the explained variance and to trends in the North Pacific sector, over the United States, and extending into the North Atlantic sector. Consistent with previous studies, the largest and most significant AO-related contributions are during the cold season (October-March). particularly over the eastern half of the United States, the North Atlantic sector, Eurasia, and the polar cap. The results indicate that a significant portion of the skill of climate forecast models will likely arise from an ability to forecast the temporal and spatial variability of the interdecadal shifts in tropical precipitation as well as the associated teleconnection patterns into midlatitudes. Because the AO encompasses the North Atlantic oscillation, it appears that additional increases in skill over portions of North America require forecasts of the AO. C1 NOAA, NCEP, NWS,Climate Predict Ctr, Anal Branch, Camp Springs, MD 20746 USA. RP Higgins, RW (reprint author), NOAA, NCEP, NWS,Climate Predict Ctr, Anal Branch, World Weather Bldg,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 35 TC 76 Z9 82 U1 0 U2 10 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 NOV 15 PY 2000 VL 13 IS 22 BP 3994 EP 4017 DI 10.1175/1520-0442(2000)013<3994:DFITSP>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375ZK UT WOS:000165433200006 ER PT J AU Owen, TW Gallo, KP AF Owen, TW Gallo, KP TI Updated population metadata for United States historical climatology network stations SO JOURNAL OF CLIMATE LA English DT Article ID COVER AB The United States Historical Climatology Network (HCN) serial temperature dataset is comprised of 1211 high-quality, long-term climate observing stations. The HCN dataset is available in several versions, one of which includes population-based temperature modifications to adjust urban temperatures for the "heat-island" effect. Unfortunately, the decennial population metadata file is not complete as missing values are present for 17.6% of the 12 210 population values associated with the 1221 individual stations during the 1900-90 interval. Retrospective grid-based populations; within a fixed distance of an HCN station, were estimated through the use of a gridded population density dataset and historically available U.S. Census county data. The grid-based populations for the HCN stations provide values derived from a consistent methodology compared to the current HCN populations that can vary as definitions of the area associated with a city change over time. The use of grid-based populations may minimally be appropriate to augment populations for HCN climate stations that lack any population data, and are recommended when consistent and complete population data are required. The recommended urban temperature adjustments based on the HCN and grid-based methods of estimating station population can be significantly different for individual stations within the HCN dataset. C1 Natl Climat Data Ctr, Asheville, NC USA. NESDIS, NOAA, Off Res & Applicat, Camp Springs, MD USA. RP Gallo, KP (reprint author), USGS EROS Data Ctr, 47914 252nd St, Sioux Falls, SD 57198 USA. RI Gallo, Kevin P./F-5588-2010 NR 8 TC 6 Z9 6 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 NOV 15 PY 2000 VL 13 IS 22 BP 4028 EP 4033 DI 10.1175/1520-0442(2001)013<4028:UPMFUS>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375ZK UT WOS:000165433200008 ER PT J AU Lanzante, JR Gahrs, GE AF Lanzante, JR Gahrs, GE TI The "clear-sky bias" of TOVS upper-tropospheric humidity SO JOURNAL OF CLIMATE LA English DT Article ID WATER-VAPOR RADIANCES; TEMPERATURE; VARIABILITY; CLIMATOLOGY; SATELLITE AB A temporal sampling bias may be introduced due to the inability of a measurement system to produce a valid observation during certain types of situations. In this study the temporal sampling bias in satellite-derived measures of upper-tropospheric humidity (UTH) was examined through the utilization of similar humidity measures derived from radiosonde data. This bias was estimated by imparting the temporal sampling characteristics of the satellite system onto the radiosonde observations. This approach was applied to UTH derived from Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder radiances from the NOAA-10 satellite from the period 1987-91 and from the "Angell" network of 63 radiosonde stations for the same time period. Radiative modeling was used to convert both the satellite and radiosonde data to commensurate measures of UTH. Examination of the satellite temporal sampling bias focused on the effects of the "clear-sky bias" due to the inability of the satellite system to produce measurements when extensive cloud cover is present. This study indicates that the effects of any such bias are relatively small in the extratropics (about several percent relative humidity) but may be similar to5%-10% in the most convectively active regions in the Tropics. Furthermore, there is a systematic movement and evolution of the bias pattern following the seasonal migration of convection, which reflects the fact that the bias increases as cloud cover increases. The bias is less noticeable for shorter timescales (seasonal values) but becomes more obvious as the averaging time increases (climatological values); it may be that small-scale noise partially obscures the bias for shorter time averages. Based on indirect inference it is speculated that the bias may lead to an underestimate of the magnitude of trends in satellite UTH in the Tropics, particularly in the drier regions. C1 Princeton Univ, GFDL, NOAA, Princeton, NJ 08544 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ USA. RP Lanzante, JR (reprint author), Princeton Univ, GFDL, NOAA, POB 308, Princeton, NJ 08544 USA. NR 18 TC 25 Z9 25 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 NOV 15 PY 2000 VL 13 IS 22 BP 4034 EP 4041 DI 10.1175/1520-0442(2000)013<4034:TCSBOT>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375ZK UT WOS:000165433200009 ER PT J AU Wainer, I Gent, P Goni, G AF Wainer, I Gent, P Goni, G TI Annual cycle of the Brazil-Malvinas confluence region in the National Center for Atmospheric Research Climate System Model SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SOUTH-ATLANTIC-OCEAN; GEOSTROPHIC CIRCULATION; SOUTHWESTERN ATLANTIC; SEASONAL VARIABILITY; BOUNDARY CURRENTS; ARGENTINE BASIN; WORLD OCEAN; TRANSPORTS; SEPARATION; CCM3 AB The objective of this study is to compare the mean and seasonal variability of the circulation in the southwest Atlantic with observations. The results used in the comparison are from the last 200 years of a 300 year control integration of the Climate System Model (CSM). The area of study includes the confluence region between the subtropical and subpolar waters represented by the Brazil and Malvinas Currents. The seasonal variation of transport and its relationship to changes in the wind stress forcing and in the sea surface temperature are examined and compared to available oceanographic observations. This study shows that a coarse resolution climate model, such as the CSM, can successfully reproduce major characteristics of the Brazil-Malvinas confluence seasonality, although the mesoscale features involving recirculation and meander dynamics are not resolved. The CSM transport values in the region of 38 degreesS are consistent with hydrographically derived values. The transport of the CSM Brazil Current is higher during austral summer and smaller during austral winter. Conversely, the Malvinas Current transport is weaker during austral summer and stronger during austral winter. This is also consistent with observations. The CSM seasonal cycle in transport associated with both the Brazil and Malvinas Currents and its meridional displacement is closely linked to the seasonal variations in the local wind stress curl. However, the displacement is much smaller in the model than in observations. The CSM results show that the latitudinal displacement of the 24 degreesC and 17 degreesC at the South American coast beween austral summer and winter is 20 degrees and 12 degrees, respectively. This is very similar to the displacement seen in observations. C1 Univ Sao Paulo, Dept Phys Oceanog, BR-05508900 Sao Paulo, Brazil. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. US Dept Commerce, Natl Ocean & Atmospher Adm, US Atlantic Oceanog & Meteorol Lab, Miami, FL USA. RP Wainer, I (reprint author), Univ Sao Paulo, Dept Phys Oceanog, Praca Oceanog 191, BR-05508900 Sao Paulo, Brazil. RI Wainer, Ilana/B-4540-2011; Goni, Gustavo/D-2017-2012 OI Wainer, Ilana/0000-0003-3784-623X; Goni, Gustavo/0000-0001-7093-3170 NR 39 TC 29 Z9 31 U1 1 U2 1 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 NOV 15 PY 2000 VL 105 IS C11 BP 26167 EP 26177 DI 10.1029/1999JC000134 PG 11 WC Oceanography SC Oceanography GA 374NU UT WOS:000165351900008 ER PT J AU Vanderah, TA Febo, W Chan, JY Roth, RS Loezos, JM Rotter, LD Geyer, RG Minor, DB AF Vanderah, TA Febo, W Chan, JY Roth, RS Loezos, JM Rotter, LD Geyer, RG Minor, DB TI Phase equilibria and dielectric behavior in the CaO : Al(2)O(3): Nb(2)O(5) system SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE CaO : Al(2)O(3): Nb(2)O(5); xCa(2)AlNbO(6):(1-x)Ca(3)Nb O(8); Ca(2)AlNbO(6); Ca(3)Nb(2)O(8); Ca(4)Nb(2)O(9); CaO : Nb(2)O(5); microwave dielectric properties; phase diagram; calcium aluminum niobates; calcium niobates ID CRYSTAL-STRUCTURE; MICROWAVE-FREQUENCIES; COMPLEX PEROVSKITES; CERAMICS; OXIDES; POLARIZABILITIES; CAO-NB2O5; CA2NB2O7; NIOBIUM AB Subsolidus phase equilibria in the CaO:Al(2)O,:Nb(2)O(5) system at 1325 degreesC in air have been determined. One ternary phase forms, Ca(2)AlNbO(6), which exhibits a perovskite-related structure with 1:1 or NaCl-type ordering of Al(3+) and Nb(5+) on the B sites. Indexed X-ray powder diffraction data for this monoclinic compound are given (P2(1)/n (No. 11); a = 5.3780(1), b = 5.4154(1), c = 7.6248(2) Angstrom, beta = 89.968(2)degrees). The subsystem CaO-Nb(2)O(5) was reexamined at CaO contents above 70 mol% to clarify inconsistencies in the literature. Two phases were confirmed to form in this region: the polymorphic-ordered perovskite Ca(4)Nb(2)O(9), with solid solution ranging from approximately 17 to 20.5 mol% Nb(2)O(5), and the compound referred to as Ca(3)Nb(2)O(8), which was shown here to occur as essentially a point compound at the composition 75.25:24.75 CaO:Nb(2)O(5). The perovskite-related structure of the Ca(3)Nb(2)O(8)-type phase was shown to be noncubic, and further studies are in progress. Capacitance methods at 1 MHz were used to determine the dielectric constants and associated temperature coefficients for eleven compounds in the CaO:Al(2)O(3):Nb(2)O(5) system. Ca(2)AlNbO(6) and Ca(3)Nb(2)O(8) coexist in equilibria and were found to exhibit temperature coefficients of permittivity with opposite signs. Five compositions in the xCa(2)AlNbO(6):(1 -x)Ca(3)Nb(2)O(8) system mere prepared and their dielectric properties measured by dielectric resonator methods at 5-7 GHz. The relative permittivities and temperature coefficients of resonant frequency obtained for the endmembers Ca(2)AlNbO(6) and Ca(3)Nb(2)O(8) were 30, -88ppm/degreesC, and 45, +113 ppm/degreesC, respectively. Temperature compensation of the resonant frequency was obtained near x = 0.67 with a permittivity of 32; no solid solution was detected by X-ray powder diffraction. (C) 2000 Academic Press. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Puerto Rico, Cayey, PR 00736 USA. Natl Inst Stand & Technol, Elect & Elect Engn Lab, Boulder, CO 80303 USA. RP Vanderah, TA (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Chan, Julia/C-5392-2008 OI Chan, Julia/0000-0003-4434-2160 NR 50 TC 21 Z9 21 U1 2 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 15 PY 2000 VL 155 IS 1 BP 78 EP 85 DI 10.1006/jssc.2000.8894 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 378QL UT WOS:000165595000012 ER PT J AU Khalifah, P Huang, Q Ho, DM Zandbergen, HW Cava, RJ AF Khalifah, P Huang, Q Ho, DM Zandbergen, HW Cava, RJ TI La7Ru3O18 and La4.87Ru2O12: Geometric frustration in two closely related structures with isolated RuO6 octahedra SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE geometric frustration; antiferromagnets; lanthanum ruthenium oxides; valence bond sum; La7Ru3O18; La4.87Ru2O12; Sr5Re2O12 ID BOND-VALENCE PARAMETERS; CRYSTAL-STRUCTURE; MAGNETS AB The crystal structures of La7Ru3O18 and La4.87Ru2O12 have been solved from powder neutron diffraction data (R-p = 0.032) and single-crystal X-ray diffraction data (R-w = 0.070 for all 3125 reflections), respectively. Although these compounds are both the first example of their structure types, La7Ru3O18, La4.87Ru2O12, and the known compound Sr5Re2O12 all have closely related structures. La7Ru3O18 crystallizes in the rhombohedral space group R3c, with cell constants of a = 9.83677(23) Angstrom and c = 56.3493(16) Angstrom in the hexagonal setting, and with Z = 12 formula units per cell, Monoclinic La4.87Ru2O12 crystallizes in the P2(1)/c space group with cell constants of a = 5.5798(6) Angstrom, b = 10.1286(11) Angstrom, c = 19.0095(20) Angstrom, beta = 90,815(4)degrees, and Z = 4. These structures contain isolated RuO6 octahedra (d(Ru-Ru) similar to 5.7 Angstrom), which are organized into well-defined layers having trigonal or pseudo-trigonal symmetry. Furthermore, the three-dimensional patterning of Ru atoms is a nearly perfect close-packed arrangement, despite the large Ru-Ru distances, Magnetic measurements show that geometric frustration suppresses the ordering of the Ru spins and that monoclinic La4.87Ru2O12, is more frustrated than rhombohedral La7Ru3O18. (C) 2000 Academic Press. C1 Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08544 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Tech Univ Delft, Natl Ctr High Resolut Elect Microscopy, NL-2628 AL Delft, Netherlands. RP Khalifah, P (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. NR 15 TC 13 Z9 13 U1 1 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 15 PY 2000 VL 155 IS 1 BP 189 EP 197 DI 10.1006/jssc.2000.8933 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 378QL UT WOS:000165595000025 ER PT J AU Wang, CZ AF Wang, CZ TI On the atmospheric responses to tropical Pacific heating during the mature phase of El Nino SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN-OSCILLATION; ROSSBY WAVES; EQUATORIAL PACIFIC; SEASONAL CYCLE; SIMPLE-MODEL; ENSO EVENTS; LA-NINA; OCEAN; CLIMATE AB The atmospheric heating and sea surface temperature (SST) anomalies during the mature phase of El Nino are observed to show both eastern and western Pacific anomaly patterns, with positive anomalies in the equatorial eastern/central Pacific and negative anomalies in the off-equatorial western Pacific. The detailed spatial patterns of the heating anomalies differ from the SST anomalies. The heating anomalies are more equatorially confined than the SST anomalies, and maxima of positive and negative heating anomalies are located farther to the west than the SST anomalies. The Gill-Zebiak atmospheric model assumes that the atmospheric initial heating has the same spatial patterns as the SST anomalies. This assumption results in some unrealistic model simulations for El Nino. When the model heating anomaly forcing is modified to resemble the observed heating anomalies during the mature phase of El Nino, the model simulations have been improved to 1) successfully simulate equatorial easterly wind anomalies in the western Pacific, 2) correctly simulate the position of maximum westerly wind anomalies, and 3) reduce unrealistic easterly wind anomalies in the off-equatorial eastern Pacific. This paper shows that off-equatorial western Pacific negative atmospheric heating (or cold SST) anomalies are important in producing equatorial easterly wind anomalies in the western Pacific. These off-equatorial cold SST anomalies in the western Pacific also contribute to equatorial westerly wind anomalies observed in the central Pacific during the mature phase of El Nino. Although off-equatorial cold SST anomalies in the western Pacific are smaller than equatorial positive SST anomalies in the eastern Pacific, they are enough to produce atmospheric responses of comparable magnitude to the equatorial eastern Pacific. This is because the atmospheric mean state is convergent in the western Pacific and divergent in the equatorial eastern Pacific. By either removing the atmospheric mean convergence or removing off-equatorial cold SST anomalies in the western Pacific, the atmospheric responses show no equatorial easterly wind anomalies in the western Pacific. In the Gill-Zebiak model, the mean wind divergence field is an important background state, whereas the mean SST is secondary. C1 Univ Miami, NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, Miami, FL 33149 USA. RP Wang, CZ (reprint author), Univ Miami, NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Wang, Chunzai /C-9712-2009 OI Wang, Chunzai /0000-0002-7611-0308 NR 51 TC 16 Z9 24 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV 15 PY 2000 VL 57 IS 22 BP 3767 EP 3781 DI 10.1175/1520-0469(2000)057<3767:OTARTT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 375PV UT WOS:000165411200006 ER PT J AU Lehman, JH Radojevic, AM Osgood, RM Levy, M Pannell, CN AF Lehman, JH Radojevic, AM Osgood, RM Levy, M Pannell, CN TI Fabrication and evaluation of a freestanding pyroelectric detector made from single-crystal LiNbO3 film SO OPTICS LETTERS LA English DT Article AB We have packaged a rectangular 3 mm x 4 mm, 10-mum-thick Z-cut lithium niobate (LiNbO3) film produced by crystal ion slicing (CIS) and evaluated its performance as a pyroelectric optical detector. We justify the difficulty of preparing the film by showing that the freestanding detector has much greater sensitivity than the same detector bonded to a substrate. We compare the sensitivity of three CIS-film detectors with that of a detector based on a 230-mum-thick LiNbO3 plate and describe the detectors' spatial uniformity and noise-equivalent power. OCIS codes: 040.0040, 160.1890, 160.2260, 160.3730. C1 Natl Inst Stand & Technol, Sources & Detectors Grp, Boulder, CO 80303 USA. Columbia Univ, Microelect Sci Labs, New York, NY 10027 USA. Univ Kent, Sch Phys Sci, Canterbury CT2 7NZ, Kent, England. RP Lehman, JH (reprint author), Natl Inst Stand & Technol, Sources & Detectors Grp, 325 Broadway, Boulder, CO 80303 USA. NR 10 TC 24 Z9 24 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 NOV 15 PY 2000 VL 25 IS 22 BP 1657 EP 1659 DI 10.1364/OL.25.001657 PG 3 WC Optics SC Optics GA 373GX UT WOS:000165281800013 PM 18066306 ER PT J AU Ye, J Hall, JL Diddams, SA AF Ye, J Hall, JL Diddams, SA TI Precision phase control of an ultrawide-bandwidth femtosecond laser: a network of ultrastable frequency marks across the visible spectrum SO OPTICS LETTERS LA English DT Article ID MODE-LOCKED LASER AB We demonstrate that the stability of the current optical frequency comb generated by a Kerr-lens mode-locked femtosecond laser is limited by the microwave reference used for phase locking the comb spacing. Hence we implement precision frequency/phase control of the entire comb to the fundamental and second-harmonic frequencies of a stable cw laser without any external microwave reference. The stability of a cw iodine-stabilized laser is transferred to millions of comb lines (with an instability of 3 x 10(-13)) covering more than one octave of the optical frequency spectrum. In addition, the mode spacing of the comb can be used as a stable microwave frequency derived directly from a stable optical oscillator. (C) 2000 Optical Society of America OCIS codes: 230.4910, 320.7090, 120.3930, 190.2620, 220.4840. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Ye, J (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011; Diddams, Scott/L-2819-2013 NR 13 TC 52 Z9 53 U1 1 U2 5 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 NOV 15 PY 2000 VL 25 IS 22 BP 1675 EP 1677 DI 10.1364/OL.25.001675 PG 3 WC Optics SC Optics GA 373GX UT WOS:000165281800019 PM 18066312 ER PT J AU Yildirim, T Gulseren, O Kilic, C Ciraci, S AF Yildirim, T Gulseren, O Kilic, C Ciraci, S TI Pressure-induced interlinking of carbon nanotubes SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-DYNAMICS; MICROTUBULES; C-60 AB We predict new forms of carbon consisting of one- and two-dimensional networks of interlinked single-wall carbon nanotubes, some of which are energetically more stable than van del Waals packing of the nanotubes on a hexagonal lattice. These interlinked nanotubes are further transformed with higher applied external pressures to more dense and complicated stable structures, in which curvature-induced carbon sp(3) rehybridizations are formed. We also discuss the energetics of the bond formation between nanotubes and the electronic properties of these predicted novel structures. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. RP Yildirim, T (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI yildirim, taner/A-1290-2009; Kilic, Cetin/E-1336-2011 OI Kilic, Cetin/0000-0003-2690-4940 NR 18 TC 59 Z9 59 U1 1 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 2000 VL 62 IS 19 BP 12648 EP 12651 DI 10.1103/PhysRevB.62.12648 PG 4 WC Physics, Condensed Matter SC Physics GA 374XJ UT WOS:000165369700022 ER PT J AU Messick, GA Shields, JD AF Messick, GA Shields, JD TI Epizootiology of the parasitic dinoflagellate Hematodinium sp in the American blue crab Callinectes sapidus SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE Hematodinium sp.; Callinectes sapidus; seasonality; size; salinity; disease; dinoflagellate ID LOBSTER NEPHROPS-NORVEGICUS; CHIONOECETES-BAIRDI; N-SP; SEASONAL PREVALENCE; LIFE-CYCLE; WEST-COAST; KING CRAB; INFECTION; FISHERY; MANAGEMENT AB Hematodinium sp. is a parasitic dinoflagellate that infects and kills blue crabs Callinectes sapidus. Periodic outbreaks of dinoflagellate infections with subsequent high host mortalities prompted a study of the epizootiology and distribution of the crab pathogen. Hemolymph samples from over 13 000 crabs were assessed for infections over 8 yr. Moderate to high prevalences were found at several locations along the Atlantic and Gulf coasts of the United States. In the coastal bays of Maryland and Virginia, prevalence followed a seasonal pattern, with a sharp peak in late autumn. Infections were significantly more prevalent in crabs measuring less than 30 mm carapace width; host sex did not influence prevalence. Prevalences were highest in crabs collected from salinities of 26 to 30 parts per thousand; no infected crabs were found in salinities below 11 parts per thousand. Intensity of infection did not vary among crab sizes, molt stages, or sexes. Naturally and experimentally infected crabs died over 35 and 55 d in captivity, with a mean time to death of approximately 13 and 42 d, respectively. Several other crustaceans, including gammaridean amphipods, xanthid (mud) crabs, and the green crab Carcinus maenus, were found with Hematodinium-like infections. Considering its widespread distribution and high pathogenicity, we suggest that Hematodinium sp. represents a significant threat to blue crab populations in high salinity estuaries along the Atlantic and Gulf coasts of the USA. C1 Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Cooperat Oxford Lab, Oxford, MD 21654 USA. Coll William & Mary, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP Messick, GA (reprint author), Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Cooperat Oxford Lab, 904 S Morris St, Oxford, MD 21654 USA. NR 53 TC 67 Z9 76 U1 3 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 NOV 14 PY 2000 VL 43 IS 2 BP 139 EP 152 DI 10.3354/dao043139 PG 14 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 389PG UT WOS:000166246500007 PM 11145454 ER PT J AU Geltman, S AF Geltman, S TI Short-time dynamics of static field excitation and ionization SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article AB The time evolution of the excitation and ionization of a ground-state hydrogen atom in a static electric field is studied using a close-coupling expansion. The tunnelling and over-the-barrier ionization regimes of electric field strength are investigated over a range of times from zero to about 1000 au. Comparisons are made with the results of quasi-classical tunnelling theories. We find large departures from the exponential decay of the initial state that is assumed by tunnelling and Stark broadening theories. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Geltman, S (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 5 TC 8 Z9 8 U1 1 U2 1 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 NOV 14 PY 2000 VL 33 IS 21 BP 4769 EP 4777 DI 10.1088/0953-4075/33/21/320 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 379WM UT WOS:000165666200027 ER PT J AU Leo, PJ Peach, G Whittingham, IB AF Leo, PJ Peach, G Whittingham, IB TI Investigation of sodium-helium interaction potentials SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID FINE-STRUCTURE TRANSITIONS; RARE-GAS COLLISIONS; 2P(5)3S-2P(5)3P NEON LINES; CLOSE-COUPLED CALCULATION; HYPERFINE DENSITY SHIFTS; NOBLE-GASES; TEMPERATURE-DEPENDENCE; EXCITED-STATES; MATTER WAVES; PRESSURE AB We present a detailed theoretical investigation of the sodium-helium interaction and report results of quantum close-coupled calculations for the pressure-broadened widths and shifts of the sodium D lines and the 819.48 nm line over the temperature range 70-500 K, and for the total and fine-structure cross sections in the 3p(2)P level. We also present the first theoretical investigation of the hyperfine pressure shifts using a semiclassical scattering formalism and report results for the hyperfine transition in the 3s(2)S(1/2) ground state over the temperature range 70-1000 K. Finally, we calculate the refractive index of helium for sodium matter waves with velocities up to 2000 m s(-1) Several of the calculations were performed using two versions of the adiabatic molecular potentials of Peach (Peach G 1996 unpublished) and the results compared with those obtained using the I-dependent pseudo-potentials of Pascale (Pascale J 1985 XIII Summer School on euantum Optics ed J Fiutak and J Mizerski pp 39-91) and Peach (Peach G 1996 unpublished). Detailed comparisons with other theoretical calculations and experimental results are also made. C1 NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. James Cook Univ N Queensland, Sch Math & Phys Sci, Townsville, Qld 4811, Australia. RP NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 53 TC 11 Z9 11 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 14 PY 2000 VL 33 IS 21 BP 4779 EP 4797 DI 10.1088/0953-4075/33/21/321 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 379WM UT WOS:000165666200028 ER PT J AU Zheng, LA Lairson, BM Barrera, EV Shull, RD AF Zheng, LA Lairson, BM Barrera, EV Shull, RD TI Formation of nanomagnetic thin films by dispersed fullerenes SO APPLIED PHYSICS LETTERS LA English DT Article ID NOBLE-METAL SURFACES; C-60; SCATTERING; PRESSURE; AU(111); CARBON; MEDIA; C60 AB A method of forming magnetic materials using dispersed fullerenes in ferromagnetic materials has been studied. Fullerenes (C-60) have been integrated into the matrix of Co, Fe, CoFe thin films by thermal vapor codeposition. The size effects and interaction of the C-60 molecules to the metallic atoms promote a self-assembly grain growth mode to produce thin films with unique evoluted microstructures characterized by nanosize columnar grains with uniformly dispersed C-60 on the grain boundaries. These nanocrystalline films have displayed a series of promising magnetic properties, such as high out of plane remanence, high coercivity, fast magnetic switching, and unusual hysteresis behavior. (C) 2000 American Institute of Physics. [S0003- 6951(00)03646-9]. C1 Rice Univ, Dept Mech Engn & Mat Sci, Houston, TX 77005 USA. Natl Inst Stand & Technol, Magnet Mat Grp, Gaithersburg, MD 20899 USA. RP Zheng, LA (reprint author), Micron Technol Inc, 800 S Fed Way, Boise, ID 83707 USA. RI Shull, Robert/F-5971-2013 NR 20 TC 10 Z9 10 U1 0 U2 3 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 NOV 13 PY 2000 VL 77 IS 20 BP 3242 EP 3244 DI 10.1063/1.1326040 PG 3 WC Physics, Applied SC Physics GA 371FJ UT WOS:000165167600038 ER PT J AU Nakao, H Ohwada, K Takesue, N Fujii, Y Isobe, M Ueda, Y Von Zimmermann, M Hill, JP Gibbs, D Woicik, JC Koyama, I Murakami, Y AF Nakao, H Ohwada, K Takesue, N Fujii, Y Isobe, M Ueda, Y Von Zimmermann, M Hill, JP Gibbs, D Woicik, JC Koyama, I Murakami, Y TI X-ray anomalous scattering study of a charge-ordered state in NaV2O5 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-PEIERLS COMPOUND; ALPHA'-NAV2O5; TEMPERATURE; TRANSITION; SYSTEMS; EDGE AB Charge ordering of V4+ and V5+ in NaV2O5 has been studied by an x-ray diffraction technique using anomalous scattering near a vanadium K-absorption edge to critically enhance a contrast between the two ions. A dramatic energy dependence of the superlattice intensities is observed below T-C = 35 K. The charge ordering pattern is the fully charged zigzag-type ladder with the unit cell 2a X 2b X 4c, but not the chain-type originally proposed for the spin-Peierls state. Charge disproportionation suggested in our model as the average valence V4.5+/-deltac/2 is observed below T-C, showing continuous variation of delta (c) as a function of temperature. C1 Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Univ Tokyo, Inst Solid State Phys, Mat Design & Characterizat Lab, Minato Ku, Tokyo 1068666, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. High Energy Accelerator Res Org KEK, Inst Mat Struct Sci, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. RP Nakao, H (reprint author), High Energy Accelerator Res Org KEK, Inst Mat Struct Sci, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. RI Isobe, Masahiko/B-5616-2015 NR 26 TC 56 Z9 56 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 13 PY 2000 VL 85 IS 20 BP 4349 EP 4352 DI 10.1103/PhysRevLett.85.4349 PG 4 WC Physics, Multidisciplinary SC Physics GA 372RK UT WOS:000165247700039 ER PT J AU Zaliznyak, IA Hill, JP Tranquada, JM Erwin, R Moritomo, Y AF Zaliznyak, IA Hill, JP Tranquada, JM Erwin, R Moritomo, Y TI Independent freezing of charge and spin dynamics in La1.5Sr0.5CoO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC ORDER; SUPERCONDUCTIVITY; PHASE; LA0.5CA0.5MNO3; LA0.5SR1.5MNO4; MANGANITES AB We present elastic and quasielastic neutron scattering measurements characterizing peculiar short-range charge-orbital and spin order in the layered perovskite material La1.5Sr0.5CoO4. We find that below T-c approximate to 750 K holes introduced by Sr doping lose mobility and enter a statically ordered charge glass phase with loosely correlated checkerboard arrangement of empty and occupied d(3z)2-r(2) orbitals (Co3+ and Co2+). The dynamics of the resultant mixed spin system is governed by the anisotropic nature of the crystal-field Hamiltonian and the peculiar exchange pattern produced by the orbital order. It undergoes a spin freezing transition at a much lower temperature, T-s less than or similar to 30 K. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Nagoya Univ, CIRSE, Nagoya, Aichi 46401, Japan. Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 46401, Japan. RP Zaliznyak, IA (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Tranquada, John/A-9832-2009; Hill, John/F-6549-2011; Zaliznyak, Igor/E-8532-2014; OI Tranquada, John/0000-0003-4984-8857; Zaliznyak, Igor/0000-0002-9886-3255; moritomo, yutaka/0000-0001-6584-7489 NR 22 TC 66 Z9 66 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 13 PY 2000 VL 85 IS 20 BP 4353 EP 4356 DI 10.1103/PhysRevLett.85.4353 PG 4 WC Physics, Multidisciplinary SC Physics GA 372RK UT WOS:000165247700040 ER PT J AU Cheng, YT Mildner, DFR AF Cheng, YT Mildner, DFR TI A sensitive high resolution neutron imaging detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE background interference; converter foil activation; imaging plate detector; neutron beam profiles; neutron field distribution; photostimulable luminescence; portable neutron area detector; storage photostimulable phosphor ID PLATE; PERFORMANCE; RADIOGRAPHY; LUMINESCENCE; STORAGE; SINQ AB We present a two-step method for a high-resolution neutron area detector in which a metal foil with a high absorption cross section acts as a neutron to charged particle converter. After the foil is activated, the neutron field information is transferred from the converter foil to an imaging device by autoradiography. This two-step process using a storage photostimulable phosphor avoids interferences from non-neutron radiation found in the radiation field. (C) 2000 Elsevier Science B.V. All rights reserved. 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 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 11 PY 2000 VL 454 IS 2-3 BP 452 EP 459 DI 10.1016/S0168-9002(00)00495-2 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LC UT WOS:000165514200017 ER PT J AU Li, J Bierbaum, VM Leone, SR AF Li, J Bierbaum, VM Leone, SR TI Laser-induced fluorescence study of two weak vibrational bands of the O-2(+) A(2)IIu-X(2)IIg system SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CHARGE-TRANSFER REACTIONS; ION-MOLECULE REACTIONS; THERMAL ENERGIES; STATE DISTRIBUTIONS; AR; RELAXATION; COLLISIONS; O-2+; KR AB Two weak vibrational bands, the (8,0) and (8,1) bands of the O-2(+) A(2)Pi (u)-X(2)Pi (g) system, are characterized by laser-induced fluorescence for the first time. Preliminary laser-induced fluorescence (LIF) determinations on the O-2(+)(nu = 0, 1) distributions from the reactions of Ar+ and Xe+ with oxygen are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 24 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 10 PY 2000 VL 330 IS 3-4 BP 331 EP 338 DI 10.1016/S0009-2614(00)01116-7 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 375TT UT WOS:000165417900018 ER PT J AU Fayer, R Trout, JM Graczyk, TK Lewis, EJ AF Fayer, R Trout, JM Graczyk, TK Lewis, EJ TI Prevalence of Cryptosporidium, Giardia and Eimeria infections in post-weaned and adult cattle on three Maryland farms SO VETERINARY PARASITOLOGY LA English DT Article DE Cryptosporidium parvum; Cryptosporidium andersoni; Eimeria bovis; Eimeria ellipsoidalis; Giardia duodenalis; bovine-protozoa; epidemiology-protozoa ID NORTHEASTERN SPAIN; DAIRY CALVES; OOCYSTS; PARVUM; SPECIMENS; PATTERNS; DIARRHEA; HERDS; FECES; CALF AB The prevalence of Cryptosporidium, Giardia and Eimeria, in healthy, asymptomatic, post-weaned and mature cattle was investigated on three Maryland farms. One farm, a dairy research facility, had 150 multiparous Holstein milking cows; 24 were examined and Cryptosporidium andersoni was detected in three (12.5%) but neither Giardia nor Eimeria was detected. The second farm, a commercial dairy, had 57 multiparous Holstein milking cows and an equal number of heifers. Of 19 cows examined, C. parvum, Giardia duodenalis, and Eimeria bovis and/or E. ellipsoidalis were detected in two (10.5%), two (10.5%) and one (5.26%) cow, respectively. Of 23 heifers examined, C. parvum, Giardia, and E. bovis and E. ellipsoidalis, was detected in two (8.7%), four (17.4%), and five (21.7%), heifers, respectively. The third farm, a beef cattle breeding and genetics research facility, had 180 7- to 9-month old purebred black Angus. Of 118 examined for C. parvum and Giardia, 34 (28.8%) and 44 (37.3%) were positive, respectively, of 97 examined for E. bovis and/or E. ellipsoidalis 32 (33.0%) were positive. These findings, based on a method with a minimum detection level of 100 oocysts of C. parvum/g of feces, which underestimates the number of infected cattle, clearly demonstrate the presence of low level, asymptomatic infections in post-weaned and adult cattle in the United States and indicate the potential role of such cattle as reservoirs of infectious parasites. Published by Elsevier Science B.V. C1 USDA ARS, Beltsville, MD 20705 USA. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, Baltimore, MD 21205 USA. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Environm Hlth Sci, Baltimore, MD 21205 USA. NOAA, NOS, Cooperat Oxford Lab, Oxford, MD 21654 USA. RP Fayer, R (reprint author), USDA ARS, 10300 Baltimore Ave,Bldg 1040, Beltsville, MD 20705 USA. NR 37 TC 95 Z9 98 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4017 J9 VET PARASITOL JI Vet. Parasitol. PD NOV 10 PY 2000 VL 93 IS 2 BP 103 EP 112 DI 10.1016/S0304-4017(00)00356-3 PG 10 WC Parasitology; Veterinary Sciences SC Parasitology; Veterinary Sciences GA 367DL UT WOS:000090046400002 PM 11035228 ER PT J AU Sarmiento, J AF Sarmiento, J TI That sinking feeling SO NATURE LA English DT Editorial Material ID CLIMATE-CHANGE; CARBON-CYCLE; CO2 C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Sarmiento, J (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. NR 16 TC 10 Z9 11 U1 0 U2 0 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 9 PY 2000 VL 408 IS 6809 BP 155 EP 156 DI 10.1038/35041676 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 371LL UT WOS:000165180400029 PM 11089958 ER PT J AU Allman, BE McMahon, PJ Nugent, KA Paganin, D Jacobson, DL Arif, M Werner, SA AF Allman, BE McMahon, PJ Nugent, KA Paganin, D Jacobson, DL Arif, M Werner, SA TI Imaging - Phase radiography with neutrons SO NATURE LA English DT Article C1 Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. RP Allman, BE (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. RI paganin, david/B-9717-2009; Nugent, Keith/J-2699-2012; Nugent, Keith/I-4154-2016 OI Nugent, Keith/0000-0003-1522-8991; Nugent, Keith/0000-0002-4281-3478 NR 10 TC 113 Z9 118 U1 0 U2 10 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 9 PY 2000 VL 408 IS 6809 BP 158 EP 159 DI 10.1038/35041626 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 371LL UT WOS:000165180400031 PM 11089960 ER PT J AU Park, SH Parise, JB Gies, H Liu, HM Grey, GP Toby, BH AF Park, SH Parise, JB Gies, H Liu, HM Grey, GP Toby, BH TI A new porous lithosilicate with a high ionic conductivity and ion-exchange capacity SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article C1 SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11790 USA. RP Park, SH (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013; Gies, Hermann/B-6637-2009; Park, So-Hyun/F-3746-2017 OI Toby, Brian/0000-0001-8793-8285; Gies, Hermann/0000-0002-2110-2458; Park, So-Hyun/0000-0003-3127-7662 NR 14 TC 29 Z9 29 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 NOV 8 PY 2000 VL 122 IS 44 BP 11023 EP 11024 DI 10.1021/ja005527q PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 375EC UT WOS:000165385700041 ER PT J AU Nguyen, NV Richter, CA Cho, YJ Alers, GB Stirling, LA AF Nguyen, NV Richter, CA Cho, YJ Alers, GB Stirling, LA TI Effects of high-temperature annealing on the dielectric function of Ta2O5 films observed by spectroscopic ellipsometry SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; SI AB Postdeposition annealing of high-k dielectric Ta2O5 films to eliminate contaminations can adversely cause the films to crystallize, which can be detrimental to their complementary metal-oxide-semiconductor device performances. In this letter, we will show that spectroscopic ellipsometry can be used to quickly and nondestructively detect such crystallization by identifying the two relatively sharp absorption peaks at 4.7 and 5.2 eV in the complex dielectric function of the films. Such peaks are absent in amorphous Ta2O5 films. In general, these sharp structures in the dielectric function are expected from the presence of long-range order in materials, which produces singularities in their interband density of states. Using this approach, we will show that Ta2O5 films become crystalline when annealed at or above 750 degreesC and remain amorphous below 700 degreesC. (C) 2000 American Institute of Physics. [S0003-6951(00)05445-0]. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Bell Labs, Lucent Technol, Orlando, FL 32819 USA. Korea Sci & Engn Fdn, Taejon 305350, South Korea. RP Nguyen, NV (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 8 TC 26 Z9 28 U1 2 U2 10 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 NOV 6 PY 2000 VL 77 IS 19 BP 3012 EP 3014 AR PII [S0003-6951(00)05445-0] DI 10.1063/1.1324730 PG 3 WC Physics, Applied SC Physics GA 369MG UT WOS:000165069500024 ER PT J AU Molodtsov, SL Halilov, SV Servedio, VDP Schneider, W Danzenbacher, S Hinarejos, JJ Richter, M Laubschat, C AF Molodtsov, SL Halilov, SV Servedio, VDP Schneider, W Danzenbacher, S Hinarejos, JJ Richter, M Laubschat, C TI Cooper minima in the photoemission spectra of solids SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOIONIZATION CROSS-SECTIONS; RESONANT PHOTOEMISSION; DILUTE ALLOYS; VALENCE-BAND; DISPERSION; ELECTRONS; WEIGHTS; STATES AB Variations of the photoionization cross section of valence states as a function of interatomic distance are studied by means of atomic and solid-state density functional approaches and compared with photo-emission data. In contrast to the free atom case, a series of Cooper minima is found fur 4d, 5d, and 5f states in Pd, Ag, Au, and U metals. The discovered fundamental phenomenon is of high importance for the correct interpretation of photoemission data. C1 TU Dresden, Inst Oberflachenphys & Mikrostrukturphys, D-01062 Dresden, Germany. NIST, Elect Phys Grp, Gaithersburg, MD 20899 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. IFW Dresden, Dept Theoret Solid State Phys, D-01171 Dresden, Germany. RP Molodtsov, SL (reprint author), TU Dresden, Inst Oberflachenphys & Mikrostrukturphys, D-01062 Dresden, Germany. RI Servedio, Vito Domenico Pietro/P-4965-2015; Richter, Manuel/F-2485-2016 OI Servedio, Vito Domenico Pietro/0000-0003-3221-5973; Richter, Manuel/0000-0002-9999-8290 NR 20 TC 18 Z9 18 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 NOV 6 PY 2000 VL 85 IS 19 BP 4184 EP 4187 DI 10.1103/PhysRevLett.85.4184 PG 4 WC Physics, Multidisciplinary SC Physics GA 370HX UT WOS:000165118400050 PM 11056655 ER PT J AU Kareiva, P Marvier, M McClure, M AF Kareiva, P Marvier, M McClure, M TI Recovery and management options for spring/summer chinook salmon in the Columbia River Basin SO SCIENCE LA English DT Article AB Construction of four dams on the lower Snake River (in northwestern United States) between 1961 and 1975 altered salmon spawning habitat, elevated smolt and adult migration mortality, and contributed to severe declines of Snake River salmon populations. By applying a matrix model to long-term population data, we found that (i) dam passage improvements have dramatically mitigated direct mortality associated with dams; (ii) even if main stem survival were elevated to 100%, Snake River spring/summer chinook salmon (Oncorhynchus tshawytscha) would probably continue to decline toward extinction; and (iii) modest reductions in first-year mortality or estuarine mortality would reverse current population declines. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Santa Clara Univ, Dept Biol, Santa Clara, CA 95053 USA. RP McClure, M (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI McClure, Michelle/O-7853-2015 OI McClure, Michelle/0000-0003-4791-8719 NR 17 TC 177 Z9 182 U1 12 U2 90 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 NOV 3 PY 2000 VL 290 IS 5493 BP 977 EP 979 DI 10.1126/science.290.5493.977 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 370BV UT WOS:000165103200047 PM 11062128 ER PT J AU Parson, R Faeder, J Delaney, N AF Parson, R Faeder, J Delaney, N TI Charge flow and solvent dynamics in the photodissociation of solvated molecular ions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FEMTOSECOND PHOTOELECTRON-SPECTROSCOPY; GEMINATE RECOMBINATION DYNAMICS; I2-(CO2)N CLUSTER IONS; STIMULATED RAMAN-SCATTERING; SOLUTE ELECTRONIC-STRUCTURE; VB RESONANCE THEORY; VIBRATIONAL-RELAXATION; ULTRAFAST PHOTODISSOCIATION; NONEQUILIBRIUM SOLVATION; QUANTUM-THEORY AB We survey recent experimental and theoretical studies of photodissociation and recombination of dihalide ions in gas-phase clusters and liquid solution. A crucial property of these systems is the flow of excess charge within the solute, which is strongly coupled to the motion of the surrounding molecules. Using a model inspired by the theory of electron-transfer reactions, we have constructed a comprehensive physical picture of the interplay of charge flow and solvent dynamics on multiple, coupled electronic states. The consequences are sometimes surprising: for example, in excited states having antibonding character, the charge moves to the less solvated atom as the solute dissociates, leading to more efficient recombination than in neutral systems. Our analysis also predicts extremely efficient spin-orbit quenching (associated with solvent-induced curve crossings) following UV excitation of I-2(-) clustered with CO2, which has been confirmed by experiment and suggests a revised interpretation of the transient absorption peak seen in pump-probe experiments. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Parson, R (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 76 TC 28 Z9 28 U1 0 U2 5 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 NOV 2 PY 2000 VL 104 IS 43 BP 9653 EP 9665 DI 10.1021/jp0019916 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 371UN UT WOS:000165197800001 ER PT J AU Stoliarov, SI Knyazev, VD Slagle, IR AF Stoliarov, SI Knyazev, VD Slagle, IR TI Experimental study of the reaction between vinyl and methyl radicals in the gas phase. Temperature and pressure dependence of overall rate constants and product yields SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID KINETIC DATA; LASER PHOTOLYSIS AB The vinyl-methyl cross-radical reaction was studied by laser photolysis/photoionization mass spectroscopy. Overall rate constants and quantitative product yields were obtained in direct real-time experiments in the temperature region 300-900 K and bath gas (He) density (3-12) x 10(16) molecules cm(-3). The observed overall C2H3 + CH3 rate constant is independent of pressure and demonstrates a slight negative temperature dependence, which can be represented by the expression k(4) = 5.1 x 10(-7)T(-1.26) exp(-362/T) molecule(-1) cm(3) s(-1) (The expression has +/-10% uncertainty, see text for details.). Propene, acetylene, and allyl radicals were identified as primary products of the C2H3 + CH3 reaction. At room temperature propene and acetylene are the major products of the reaction, whereas at 900 K production of allyl radicals becomes the dominating channel. On the basis of these experimental results, a mechanism consisting of two major routes is proposed. One route proceeds via direct abstraction of a hydrogen atom from the vinyl radical by the methyl radical resulting in the formation of acetylene and methane. The other route proceeds via the formation of chemically activated propene that can undergo either collisional stabilization or further decomposition into allyl radical and hydrogen atom. C1 Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Slagle, IR (reprint author), Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. NR 25 TC 28 Z9 28 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 2 PY 2000 VL 104 IS 43 BP 9687 EP 9697 DI 10.1021/jp992476e PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 371UN UT WOS:000165197800006 ER PT J AU Lawn, BR Lee, KS Chai, H Pajares, A Kim, DK Wuttiphan, S Peterson, IM Hu, XZ AF Lawn, BR Lee, KS Chai, H Pajares, A Kim, DK Wuttiphan, S Peterson, IM Hu, XZ TI Damage-resistant brittle coatings SO ADVANCED ENGINEERING MATERIALS LA English DT Article ID CERAMICS; INDENTATION; COMPOSITES; ALUMINA; FRACTURE; FATIGUE 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. Univ Extremadura, Dept Fis, E-06071 Badajoz, Spain. Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. Natl Met & Mat Technol Ctr, Bangkok 10400, Thailand. Corning Inc, Corning, NY 14831 USA. Univ Western Australia, Dept Mech & Mat Engn, Nedlands, WA 6907, Australia. RP Lawn, BR (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Pajares, Antonia/I-3881-2015; Kim, Do Kyung/C-2039-2011; Hu, Xiaozhi /H-4353-2011 OI Pajares, Antonia/0000-0002-1086-7586; Kim, Do Kyung/0000-0001-9092-9427; NR 25 TC 56 Z9 56 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 1438-1656 EI 1527-2648 J9 ADV ENG MATER JI Adv. Eng. Mater. PD NOV PY 2000 VL 2 IS 11 BP 745 EP 748 DI 10.1002/1527-2648(200011)2:11<745::AID-ADEM745>3.0.CO;2-E PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 378PQ UT WOS:000165593100012 ER PT J AU Begley, EF Sturrock, CP AF Begley, EF Sturrock, CP TI MatML: XML for materials property data SO ADVANCED MATERIALS & PROCESSES LA English DT Article AB MatML is a language developed specifically for the exchange of materials property data on the World Wide Web. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Begley, EF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD NOV PY 2000 VL 158 IS 5 BP 72 EP 74 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 369PG UT WOS:000165075700007 ER PT J AU Eppeldauer, G Racz, M AF Eppeldauer, G Racz, M TI Spectral power and irradiance responsivity calibration of InSb working-standard radiometers SO APPLIED OPTICS LA English DT Article ID CRYOGENIC BOLOMETER AB New, improved-performance InSb power-irradiance meters have been developed and characterized to maintain the National Institute of Standards and Technology (NIST) spectral responsivity scale between 2 and 5.1 mum. The InSb radiometers were calibrated against the transfer-standard cryogenic bolometer that is tied to the primary-standard cryogenic radiometer of the NIST. The InSb radiometers serve as easy-to-use working standards for routine spectral power and irradiance responsivity calibrations. The spectral irradiance responsivities were derived from the spectral power responsivities by use of the measured area of the apertures in front of the InSb detectors. (C) 2000 Optical Society of America. OCIS codes: 040.0040, 040.3060, 040.5350, 120.5630, 230.5160. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Hungarian Acad Sci, Res Inst Tech Phys & Mat Sci, Natl Inst Stand & Technol, H-1121 Budapest, Hungary. Konkoly Observ Budapest, H-1121 Budapest, Hungary. RP Eppeldauer, G (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. EM geppeldauer@nist.gov NR 12 TC 12 Z9 12 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 2000 VL 39 IS 31 BP 5739 EP 5744 DI 10.1364/AO.39.005739 PG 6 WC Optics SC Optics GA 369EJ UT WOS:000165052800011 PM 18354571 ER PT J AU Etzel, SM Rose, AH Wang, CM AF Etzel, SM Rose, AH Wang, CM TI Dispersion of the temperature dependence of the retardance in SiO2 and MgF2 SO APPLIED OPTICS LA English DT Article AB We have directly measured the retardance versus temperature for single-crystal quartz (SiO2) and magnesium fluoride (MgF2) at wavelengths of 633, 788, 1318, and 1539 nm and over a temperature range of 24-80 degreesC. To our knowledge, the temperature dependence of retardance for these two materials has not been directly measured. We compared our direct measurements of the normalized temperature derivative of the retardance gamma with derived values from previously reported indirect measurements and found our results to be in agreement and our measurement uncertainties to be typically a factor of 4 smaller. Our overall mean value for gamma (SiO2) is -1.23 X 10(-4) with a combined standard uncertainty of 0.02 X 10(-4) and little wavelength dependence over the 633-1539-nm range. Our overall mean value for gamma (MgF2) is -5.37 X 10(-5) with a combined standard uncertainty of 0.17 X 10(-5) and with a small wavelength dependence over the 633-1539-nm range. (C) 2000 Optical Society of America OCIS codes: 120.5410, 120.6780, 160.4760. C1 US Dept Commerce, Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Etzel, SM (reprint author), US Dept Commerce, Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM etzel@boulder.nist.gov NR 9 TC 6 Z9 6 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 2000 VL 39 IS 31 BP 5796 EP 5800 DI 10.1364/AO.39.005796 PG 5 WC Optics SC Optics GA 369EJ UT WOS:000165052800020 PM 18354580 ER PT J AU Shearer, KD Swanson, P AF Shearer, KD Swanson, P TI The effect of whole body lipid on early sexual maturation of 1+age male chinook salmon (Oncorhynchus tshawytscha) SO AQUACULTURE LA English DT Article DE chinook salmon (Oncorhynchus tshawytscha); early male maturation; spermatogenesis; gonadotropin; insulin like growth factor-I ID GROWTH-FACTOR-I; MALE ATLANTIC SALMON; PARR-SMOLT TRANSFORMATION; MALE MASU SALMON; REPRODUCTIVE-CYCLE; COHO SALMON; SALAR L; PRECOCIOUS MATURATION; PITUITARY-CELLS; GONADOTROPIN-I AB Early sexual maturation of male chinook salmon (maturation 1 to 4 years prior to females in the same age class) results in reduced effectiveness of stock enhancement programs and a financial loss to the salmon farming industry, previous studies in Atlantic salmon have shown that the age of maturity in males is affected by growth and/or body energy stores, but the relative roles of these two factors are not well understood. Therefore, an experiment was designed to determine when spermatogenesis was initiated, to characterize the endocrine changes during the onset of puberty in male salmon, and to determine if the level of whole-body lipid affects the incidence of early male maturation in a wild stock (Yakima River) of 1 + spring chinook salmon. Fry were fed a commercial diet from February until August and were then divided into groups of 320 fish (mean weight, 5.6 g) and fed one of five experimental diets (two replicate groups/diet) containing 4%, 9%, 14%, 18% or 22% lipid and 82%, 77%, 73%, 69%, or 65% protein for 13 months. Fish were reared on natural photoperiod and ambient temperature (6 degrees C to 16 degrees C), and pair-fed to a level based on the tank with the lowest feed consumption. Fish were weighed monthly and sampled to determine body composition, pituitary follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, plasma insulin-like growth factor I(IGF-I) levels, and stage of gonadal development. Throughout the experimental period the mean fish weight was similar among treatment groups. However, from December through the end of the experiment in the following September, maturing males were significantly larger than nonmaturing fish. Initial lipid levels in 0-age experimental fish were near 6%, which is similar to wild fish of the same stock and age captured in the Yakima River during August. Fish fed diets containing more than 4% lipid increased in whole-body lipid content during the first 2 months of feeding and then maintained at relatively constant levels during the course of the experiment. Whole-body lipid levels for the dietary treatment groups averaged 5.6%, 7.1%, 8.2%, 9.4%, and 9.6% from October through the following September. Based on histological examination of the testes of experimental fish, type B spermatogonia and primary spermatocytes were first observed in some of the yearling males during November. These were designated maturing males. Pituitary FSH levels were significantly higher in maturing than nonmaturing males at this time and for the remainder of the study. Pituitary FSH levels increased as spermatogenesis proceeded in maturing fish, whereas pituitary LPI levels increased in maturing 1 + males only during July and August, when testes were in late stages of spermatogenesis and in September during spermiation. Plasma IGF-I levels were significantly higher in maturing males than nonmaturing fish from December through the end of experiment. Since maturing males were significantly larger than nonmaturing fish of both sexes from December through September, the difference in IGF-I levels could be due to differences in growth or due to maturation. The percentage of maturing males was significantly influenced by whole-body lipid, increasing from 34% in fish fed the 4% lipid diet to 45% in fish fed the 22% lipid diet. These data suggest that whole-body lipid levels influenced the incidence of maturation of male spring chinook salmon. In addition, both endocrine and histological indicators suggest that maturation was initiated in males approximately a full year prior to the time the fish will spawn. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Shearer, KD (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM karl.d.shearer@noaa.gov NR 76 TC 88 Z9 89 U1 4 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD NOV 1 PY 2000 VL 190 IS 3-4 BP 343 EP 367 DI 10.1016/S0044-8486(00)00406-3 PG 25 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 352NG UT WOS:000089224300011 ER PT J AU Hyrenbach, KD Forney, KA Dayton, PK AF Hyrenbach, KD Forney, KA Dayton, PK TI Marine protected areas and ocean basin management SO AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS LA English DT Review DE fronts; highly migratory species; marine protected area (MPA); migration routes; ocean basin conservation; pelagic conservation; seamounts ID NORTH PACIFIC-OCEAN; SPERM WHALE DISTRIBUTIONS; EASTERN TROPICAL PACIFIC; STREAM FRONTAL EDDIES; CALIFORNIA CURRENT; BERING SEA; SUBMARINE-CANYON; FORAGING ECOLOGY; THUNNUS-ALALUNGA; PHYTOPLANKTON AB 1. All reserve designs must be guided by an understanding of natural history and habitat variability. 2. Differences in scale and predictability set aside highly dynamic pelagic systems from terrestrial and nearshore ecosystems, where wildlife reserves were first implemented. Yet, as in static systems, many pelagic species use predictable habitats to breed and forage. Marine protected areas (MPAs) could be designed to protect these foraging and breeding aggregations. 3. Understanding the physical mechanisms that influence the formation and persistence of these aggregations is essential in order to define and implement pelagic protected areas. We classify pelagic habitats according to their dynamics and predictability into three categories: static, persistent and ephemeral features. 4. While traditional designs are effective in static habitats, many important pelagic habitats are neither fixed nor predictable. Thus, pelagic protected areas will require dynamic boundaries and extensive buffers. 5. In addition, the protection of far-ranging pelagic vertebrates will require dynamic MPAs defined by the extent and location of large-scale oceanographic features. 6. Recent technological advances and our ability to implement large-scale conservation actions will facilitate the implementation of pelagic protected areas. 7. The establishment of pelagic MPAs should include enforcement, research and monitoring programmes to evaluate design effectiveness. 8. Ultimately, society will need a holistic management scheme for entire ocean basins. Such overarching management will rely on many innovative tools, including the judicious use of pelagic MPAs. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Scripps Inst Oceanog, La Jolla, CA 92093 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Monterey, CA USA. RP Scripps Inst Oceanog, La Jolla, CA 92093 USA. EM khyrenba@coast.ucsd.edu NR 167 TC 184 Z9 194 U1 11 U2 77 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1052-7613 EI 1099-0755 J9 AQUAT CONSERV JI Aquat. Conserv.-Mar. Freshw. Ecosyst. PD NOV-DEC PY 2000 VL 10 IS 6 BP 437 EP 458 DI 10.1002/1099-0755(200011/12)10:6<437::AID-AQC425>3.3.CO;2-H PG 22 WC Environmental Sciences; Marine & Freshwater Biology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 384MC UT WOS:000165945800004 ER PT J AU Fisher, WS Oliver, LM Winstead, JT Long, ER AF Fisher, WS Oliver, LM Winstead, JT Long, ER TI A survey of oysters Crassostrea virginica from Tampa Bay, Florida: associations of internal defense measurements with contaminant burdens SO AQUATIC TOXICOLOGY LA English DT Article DE oyster; Crassostrea virginica; internal defense; immune system; chemical contamination; estuarine contamination; Tampa Bay; trace metals; bioaccumulation ID MUSSEL MYTILUS-EDULIS; COMMON MARINE MUSSEL; PERKINSUS-MARINUS; EASTERN OYSTERS; APALACHICOLA BAY; HEMOCYTES WITHDRAWN; EXPOSURE; TRIBUTYLTIN; VARIABILITY; MERCENARIA AB Oysters from 16 sites in Tampa Bay, Florida, were collected during a 6-week period in winter 1993 and analyzed for both biological characteristics and tissue chemical concentrations. Using previous sediment contamination and toxicity data, oyster tissues from the selected sites were expected to exhibit a wide range in both quantity and type of chemicals. Chemical analysis showed tissue concentrations at some of these sites to be greater than national averages, as reported by the National Status and Trends Mussel Watch Program, for total PAH, total PCB, total chlordanes, DDT, Cu, Pb and Zn. Measures of oyster internal defense, including hemocyte density, rate of locomotion and superoxide generation, varied significantly among sites and were generally higher at sites with higher tissue concentrations of xenobiotic chemicals. Potential associations between oyster defense characteristics and accumulated chemical contaminants, either singly or in chemical classes, were explored using correlation analysis and a composited ranking procedure. Positive relationships were found for hemocyte characteristics with certain trace metal (Cu, Sn and Zn) and PAH analytes, whereas negative relationships were found with certain PCB and pesticide analytes. Heightened defenses in contaminated conditions may reflect a hemocyte process for sequestration and detoxification of environmental contaminants. Oysters from four of the 16 sites were additionally collected in June and September 1993 and site-related differences did not closely parallel those obtained in winter. Seasonal environmental factors may have altered contaminant-related differences among sites. (C) 2000 Elsevier Science B.V. All rights reserved. C1 US EPA, Natl Hlth & Environm Effects Res Lab, Gulf Ecol Div, Gulf Breeze, FL 32561 USA. NOAA, Natl Ctr Coastal Ocean Sci, Seattle, WA 98115 USA. RP Fisher, WS (reprint author), US EPA, Natl Hlth & Environm Effects Res Lab, Gulf Ecol Div, 1 Sabine Isl Dr, Gulf Breeze, FL 32561 USA. EM fisher.william@epa.gov NR 61 TC 65 Z9 72 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X EI 1879-1514 J9 AQUAT TOXICOL JI Aquat. Toxicol. PD NOV PY 2000 VL 51 IS 1 BP 115 EP 138 DI 10.1016/S0166-445X(00)00082-5 PG 24 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA 358DZ UT WOS:000089543100010 PM 10998504 ER PT J AU Tsai, AM Neumann, DA Bell, LN AF Tsai, AM Neumann, DA Bell, LN TI Molecular dynamics of solid-state lysozyme as affected by glycerol and water: A neutron scattering study SO BIOPHYSICAL JOURNAL LA English DT Article ID LYOPHILIZED BOVINE SOMATOTROPIN; THERMALLY-INDUCED DENATURATION; GLASS-TRANSITION; PROTEIN DYNAMICS; NATIVE PROTEIN; TEMPERATURE; MYOGLOBIN; STABILIZATION; VISCOSITY; TREHALOSE AB Glycerol has been shown to lower the heat denaturation temperature (T-m) of dehydrated lysozyme while elevating the T-m of hydrated lysozyme (Bell, Hageman, and Muraoka, 1995. J. Pharm. Sci. 84:707-712). Here, we report an in situ elastic neutron scattering study of the effect of glycerol and hydration on the internal dynamics of lysozyme powder. Anharmonic motions associated with structural relaxation processes were not detected for dehydrated lysozyme in the temperature range of 40 to 450K. Dehydrated lysozyme was found to have the highest T-m by Bell et al. (1995b). Upon the addition of glycerol or water, anharmonicity was recovered above a dynamic transition temperature (T-d), which may contribute to the reduction of T-m values for dehydrated lysozyme in the presence of glycerol. The greatest degree of anharmonicity, as well as the lowest T-d, was observed for lysozyme solvated with water. Hydrated lysozyme was also found to have the lowest T-m by Bell et al. (1995b). In the regime above T-d, larger amounts of glycerol lead to a higher rate of change in anharmonic motions as a function of temperature, rendering the material more heat labile. Below T-d, where harmonic motions dominate, the addition of glycerol resulted in a lower amplitude of motions, correlating with a stabilizing effect of glycerol on the protein. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Auburn Univ, Auburn, AL 36849 USA. RP Tsai, AM (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, 100 Bureau Dr, Gaithersburg, MD 20899 USA. EM amos.tsai@nist.gov NR 39 TC 128 Z9 129 U1 3 U2 29 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 2000 VL 79 IS 5 BP 2728 EP 2732 PG 5 WC Biophysics SC Biophysics GA 370CE UT WOS:000165104500043 PM 11053145 ER PT J AU Peppler, RA Bahrmann, CP Barnard, JC Campbell, JR Cheng, MD Ferrare, RA Halthore, RN Heilman, LA Hlavka, DL Laulainen, NS Lin, CJ Ogren, JA Poellot, MR Remer, LA Sassen, K Spinhirne, JD Splitt, ME Turner, DD AF Peppler, RA Bahrmann, CP Barnard, JC Campbell, JR Cheng, MD Ferrare, RA Halthore, RN Heilman, LA Hlavka, DL Laulainen, NS Lin, CJ Ogren, JA Poellot, MR Remer, LA Sassen, K Spinhirne, JD Splitt, ME Turner, DD TI ARM Southern Great Plains site observations of the smoke pall associated with the 1998 Central American fires SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID RAMAN LIDAR MEASUREMENTS; OPTICAL-PROPERTIES; WATER-VAPOR; SIZE DISTRIBUTION; ATMOSPHERIC RADIATION; AEROSOL EXTINCTION; MICROPULSE LIDAR; FLOW PATTERNS; TRAJECTORIES; BRAZIL AB Drought-stricken areas of Central America and Mexico were victimized in 1998 by forest and brush fires that burned out of control during much of the first half of the year. Wind currents at various times during the episode helped transport smoke from these fires over the Gulf of Mexico and into portions of the United Slates. Visibilities were greatly reduced during favorable flow periods from New Mexico to south Florida and northward to Wisconsin as a result of this smoke and haze. In response to the reduced visibilities and increased pollutants, public health advisories and information statements were issued by various agencies in Gulf Coast states and in Oklahoma. This event was also detected by a unique array of instrumentation deployed at the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program Southern Great Plains Cloud and Radiation Testbed and by sensors of the Oklahoma Department of Environmental Quality/Air Quality Division. Observations from these measurement devices suggest elevated levels of aerosol loading and ozone concentrations during May 1998 when prevailing winds were favorable for the transport of the Central American smoke pall into Oklahoma and Kansas. In particular, aerosol extinction profiles derived from the ARM Raman lidar measurements revealed large variations in the vertical distribution of the smoke. C1 Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. Pacific NW Natl Lab, Richland, WA USA. Sci Syst & Applicat Inc, Lanham, MD USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NASA, Langley Res Ctr, Sci Applicat Int Corp, Hampton, VA 23665 USA. Oak Ridge Associated Univ, Oak Ridge, TN USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ N Dakota, Grand Forks, ND 58201 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Utah, Salt Lake City, UT USA. Univ Utah, Cooperat Inst Reg Predict, Salt Lake City, UT USA. RP Peppler, RA (reprint author), Cooperat Inst Mesoscale Meteorol Studies, 100 E Boyd St,Room 1110, Norman, OK 73019 USA. RI Campbell, James/C-4884-2012; Cheng, Meng-Dawn/C-1098-2012; Xiongfei, Zhao/G-7690-2015; Ogren, John/M-8255-2015; Lin, Che-Jen/K-1808-2013; OI Campbell, James/0000-0003-0251-4550; Ogren, John/0000-0002-7895-9583; Lin, Che-Jen/0000-0001-5990-3093; Splitt, Michael/0000-0002-7690-5100 NR 52 TC 51 Z9 52 U1 2 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 NOV PY 2000 VL 81 IS 11 BP 2563 EP 2591 DI 10.1175/1520-0477(2000)081<2563:ASGPSO>2.3.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370BB UT WOS:000165101300001 ER PT J AU Shukla, J Anderson, J Baumhefner, D Brankovic, C Chang, Y Kalnay, E Marx, L Palmer, T Paolino, D Ploshay, J Schubert, S Straus, D Suarez, M Tribbia, J AF Shukla, J Anderson, J Baumhefner, D Brankovic, C Chang, Y Kalnay, E Marx, L Palmer, T Paolino, D Ploshay, J Schubert, S Straus, D Suarez, M Tribbia, J TI Dynamical seasonal prediction SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PREDICTABILITY; MODEL; SIMULATION; VARIABILITY; CIRCULATION; FORECASTS; ANOMALIES; PROJECT; ENSO AB Dynamical Seasonal Prediction (DSP) is an informally coordinated multi-institution research project to investigate the predictability of seasonal mean atmospheric circulation and rainfall. The basic idea is to test the feasibility of extending the technology of routine numerical weather prediction beyond the inherent limit of deterministic predictability of weather to produce numerical climate predictions using state-of-the-art global atmospheric models. Atmospheric general circulation models (AGCMs) either forced by predicted sea surface temperature (SST) or as part of a coupled forecast system have shown in the past that certain regions of the extratropics, in particular, the Pacific-North America (PNA) region during Northern Hemisphere winter, can be predicted with significant skill especially during years of large tropical SST anomalies. However, there is still a great deal of uncertainty about how much the details of various AGCMs impact conclusions about extratropical seasonal prediction and predictability. DSP is designed to compare seasonal simulation and prediction results from five state-of-the-art U.S. modeling groups (NCAR, COLA, GSFC, GFDL, NCEP) in order to assess which aspects of the results are robust and which are model dependent. The initial emphasis is on the predictability of seasonal anomalies over the PNA region. This paper also includes results from the ECMWF model, and historical forecast skill over both the PNA region and the European region is presented for all six models. It is found that with specified SST boundary conditions, all models show that the winter season mean circulation anomalies over the Pacific-North American region are highly predictable during years of large tropical sea surface temperature anomalies. The influence of large anomalous boundary conditions is so strong and so reproducible that the seasonal mean forecasts can be given with a high degree of confidence. However, the degree of reproducibility is highly variable from one model to the other, and quantities such as the PNA region signal to noise ratio are found to vary significantly between the different AGCMs. It would not be possible to make reliable estimates of predictability of the seasonal mean atmosphere circulation unless causes for such large differences among models are understood. C1 George Mason Univ, Ctr Ocean Land Atmosphere Studies, Calverton, MD 20705 USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. Goddard Space Flight Ctr, Greenbelt, MD USA. Natl Ctr Environm Predict, Camp Springs, MD USA. RP Shukla, J (reprint author), George Mason Univ, Ctr Ocean Land Atmosphere Studies, 4041 Powder Mill Rd,Suite 302, Calverton, MD 20705 USA. RI Kalnay, Eugenia/F-4393-2010; OI Palmer, Tim/0000-0002-7121-2196; Kalnay, Eugenia/0000-0002-9984-9906 NR 30 TC 175 Z9 181 U1 1 U2 17 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 NOV PY 2000 VL 81 IS 11 BP 2593 EP 2606 DI 10.1175/1520-0477(2000)081<2593:DSP>2.3.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370BB UT WOS:000165101300002 ER PT J AU Gruber, A Su, XJ Kanamitsu, M Schemm, J AF Gruber, A Su, XJ Kanamitsu, M Schemm, J TI The comparison of two merged rain gauge-satellite precipitation datasets SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GLOBAL PRECIPITATION; RETRIEVAL; PROJECT AB Two large-scale precipitation datasets, one produced by the Global Precipitation Climatology Project (GPCP) and the other by the Climate Prediction Center of the National Weather Service, and called Climate Prediction Center Merged Analysis of Precipitation (CMAP), were compared. Both datasets blend satellite and gauge estimates of precipitation. And while the latter has its heritage in the GPCP, different analysis procedures and some additional types of input data used by CMAP yielded different values. This study used the error characteristics of the data to assess the significance of the observed differences. Despite good spatial and temporal correlations between the two fields some of the observed differences were significant at the 95% level. These were traced to the use of some different input data such as the use by CMAP of atoll gauges in the tropical Pacific and gauges uncorrected for wetting evaporation and aerodynamic effects. The former impacts the tropical ocean rain amounts and the latter is particularly noticeable in the Northern Hemisphere land areas. Also, the application of these datasets to the validation of atmospheric general circulation models is discussed. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. NOAA, NWS, Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. RP Gruber, A (reprint author), NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. NR 21 TC 69 Z9 72 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 NOV PY 2000 VL 81 IS 11 BP 2631 EP 2644 DI 10.1175/1520-0477(2000)081<2631:TCOTMR>2.3.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370BB UT WOS:000165101300005 ER PT J AU Droegemeier, KK Smith, JD Businger, S Doswell, C Doyle, J Duffy, C Foufoula-Georgiou, E Graziano, T James, LD Krajewski, V LeMone, M Lettenmaier, D Mass, C Pielke, R Ray, P Rutledge, S Schaake, J Zipser, E AF Droegemeier, KK Smith, JD Businger, S Doswell, C Doyle, J Duffy, C Foufoula-Georgiou, E Graziano, T James, LD Krajewski, V LeMone, M Lettenmaier, D Mass, C Pielke, R Ray, P Rutledge, S Schaake, J Zipser, E TI Hydrological aspects of weather prediction and flood warnings: Report of the Ninth Prospectus Development Team of the US Weather Research Program SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID FLASH-FLOOD; RADAR; SYSTEMS; DESIGN AB Among the many natural disasters that disrupt human and industrial activity in the United States each year, including tornadoes, hurricanes, extreme temperatures, and lightning, floods are among the most devastating and rank second in the loss of life. Indeed, the societal impact of floods has increased during the past few years and shows no sign of abating. Although the scientific questions associated with flooding and its accurate prediction are many and complex, an unprecedented opportunity now exists-in light of new observational and computing systems and infrastructures, a much improved understanding of small-scale meteorological and hydrological processes, and the availability of sophisticated numerical models and data assimilation systems-to attack the flood forecasting problem in a comprehensive manner that will yield significant new scientific insights and corresponding practical benefits. The authors present herein a set of recommendations for advancing our understanding of floods via the creation of natural laboratories situated in a variety of local meteorological and hydrological settings. Emphasis is given to floods caused by convection and cold season events, fronts and extratropical cyclones, orographic forcing, and hurricanes and tropical cyclones following landfall. Although the particular research strategies applied within each laboratory setting will necessarily vary, all will share the following principal elements: (a) exploitation of those couplings important to flooding that exist between meteorological and hydrological processes and models; (b) innovative use of operational radars, research radars, satellites, and rain gauges to provide detailed spatial characterizations of precipitation fields and rates, along with the use of this information in hydrological models and for improving and validating microphysical algorithms in meteorological models; (c) comparisons of quantitative precipitation estimation algorithms from both research (especially multiparameter) and operational radars against gauge data as well as output produced by meso- and storm-scale models; (d) use of data from dense, temporary river gauge networks to trace the fate of rain from its starting location in small basins to the entire stream and river network; and (e) sensitivity testing in the design and implementation of separate as well as coupled meteorological and hydrologic models, the latter designed to better represent those nonlinear feedbacks between the atmosphere and land that are known to play an important role in runoff prediction. Vital to this effort will be the creation of effective and sustained linkages between the historically separate though scientifically related disciplines of meteorology and hydrology, as well as their observational infrastructures and research methodologies. C1 Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. US Geol Survey, Boulder, CO USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. USN, Res Lab, Washington, DC 20375 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Minnesota, Twin Cities, MN USA. Natl Weather Serv, Meteorol Off, Silver Spring, MD USA. Natl Sci Fdn, Arlington, VA 22230 USA. Univ Iowa, Iowa City, IA USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Washington, Seattle, WA 98195 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Florida State Univ, Tallahassee, FL 32306 USA. Natl Weather Serv, Off Hydrol, Silver Spring, MD USA. Univ Utah, Salt Lake City, UT USA. RP Droegemeier, KK (reprint author), Univ Oklahoma, Sch Meteorol, Sakeys Energy Ctr Suite 1310,100 E Boyd St, Norman, OK 73019 USA. RI Pielke, Roger/A-5015-2009; lettenmaier, dennis/F-8780-2011 OI lettenmaier, dennis/0000-0003-3317-1327 NR 31 TC 50 Z9 50 U1 0 U2 9 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 NOV PY 2000 VL 81 IS 11 BP 2665 EP 2680 DI 10.1175/1520-0477(2000)081<2665:HAOWPA>2.3.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370BB UT WOS:000165101300007 ER PT J AU Lowry, LF Burkanov, VN Frost, KJ Simpkins, MA Davis, R DeMaster, DP Suydam, R Springer, A AF Lowry, LF Burkanov, VN Frost, KJ Simpkins, MA Davis, R DeMaster, DP Suydam, R Springer, A TI Habitat use and habitat selection by spotted seals (Phoca largha) in the Bering Sea SO CANADIAN JOURNAL OF ZOOLOGY LA English DT Article ID STATISTICAL TECHNIQUES; RESOURCE SELECTION; SATELLITE TRACKING; CHUKCHI SEAS; ICE COVER; TELEMETRY AB Twelve spotted seals (Phoca largha) equipped with satellite-linked tags were tracked in the Bering Sea for 46-272 days during August-June 1991-1994. Alaskan seals were mostly near shore during August-October and 100-200 km offshore in January-June, and were broadly distributed in the region north of the 200-m isobath. Russian seals were located primarily near shore and within 100 km of the 200-m isobath during all months. During August-October, all seals were usually more than 200 km south of the sea-ice edge. In January-June, seals were mostly 0-200 km north of the sea-ice edge, often in areas with extensive ice coverage (7/10-9/10). We tested for habitat selection by determining how frequently a randomly moving seal would have been located in each habitat and comparing that with observed habitat use. Russian seals selected for nearshore and shallow-water areas in September-October and for near shore, within 25 km of the 200-m isobath, and the ice front during November-April. Alaskan seals selected for near shore areas in September-December; for offshore, shallow water, and the ice front in January-February; and for shallow water and pack ice in March-April. Biological processes associated with the highly productive "Green Belt" may have influenced the habitat use of Russian seals, but this did not appear to have been the case with Alaskan seals. C1 Alaska Dept Fish & Game, Fairbanks, AK 99701 USA. Alaska Sea Life Ctr, Seward, AK 99664 USA. Univ Alaska, Sch Fisheries & Ocean Sci, Fairbanks, AK 99775 USA. Texas A&M Univ, Dept Marine Biol, Galveston, TX 77553 USA. NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. N Slope Borough Dept Wildlife Management, Barrow, AK 99723 USA. RP Lowry, LF (reprint author), Alaska Dept Fish & Game, 1300 Coll Rd, Fairbanks, AK 99701 USA. EM llowry@eagle.ptialaska.net NR 36 TC 25 Z9 26 U1 1 U2 11 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4301 EI 1480-3283 J9 CAN J ZOOL JI Can. J. Zool. PD NOV PY 2000 VL 78 IS 11 BP 1959 EP 1971 DI 10.1139/cjz-78-11-1959 PG 13 WC Zoology SC Zoology GA 366QQ UT WOS:000090016400010 ER PT J AU Widmann, JF Charagundla, SR Presser, C AF Widmann, JF Charagundla, SR Presser, C TI Aerodynamic study of a vane-cascade swirl generator SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE swirl; turbulence; fluid mechanics; numerical analysis; simulation; CFD; pitot probe; spray combustion ID TURBULENCE MODELS; FLOWS; EXPANSION; CLOSURE AB The air how through a vane-cascade swirl generator is examined both experimentally and numerically to characterize the inlet combustion air flow entering a reference spray combustion facility at NIST. A three-dimensional model is used to simulate the aerodynamics in the 12-vane-cascade swirl generator that imparts the desired degree of angular momentum to the air in the annulus leading into the reactor. A numerical simulation using the renormalization group method (RNG) k-epsilon turbulence model results in a velocity profile consistent with experimental measurements, and correctly predicts a recirculation zone that is experimentally observed at the exit of the annular passage. The standard k-epsilon turbulence model does not compare as well with the experimental data and fails to predict the recirculation zone at the exit. This work is part of a larger project at NIST in which benchmark data are collected for input and validation of multiphase combustion models, and the results presented provide a well-characterized inlet condition for the spray combustion reactor. The good agreement between the experimental data and the simulation with the RNG k-epsilon turbulence model provides further validation for this model in confined, annular flows. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Widmann, JF (reprint author), NIST, Chem Sci & Technol Lab, 100 Bur Dr,Stop 8360, Gaithersburg, MD 20899 USA. NR 20 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD NOV PY 2000 VL 55 IS 22 BP 5311 EP 5320 DI 10.1016/S0009-2509(00)00145-7 PG 10 WC Engineering, Chemical SC Engineering GA 373YZ UT WOS:000165318800009 ER PT J AU Plazanet, M Johnson, MR Gale, JD Yildirim, T Kearley, GJ Fernandez-Diaz, MT Sanchez-Portal, D Artacho, E Soler, JM Ordejon, P Garcia, A Trommsdorff, HP AF Plazanet, M Johnson, MR Gale, JD Yildirim, T Kearley, GJ Fernandez-Diaz, MT Sanchez-Portal, D Artacho, E Soler, JM Ordejon, P Garcia, A Trommsdorff, HP TI The structure and dynamics of crystalline durene by neutron scattering and numerical modelling using density functional methods SO CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-CRYSTALS; VIBRATIONAL-RELAXATION; SYSTEMS; SPECTRA; ACETANILIDE; EXCITATION; SOLIDS; STATES; MODES AB Inelastic neutron scattering (INS) and single crystal diffraction measurements of tetramethylbenzene (durene) are reported along with first-principles calculations, based on density functional theory (DFT), of structure and dynamics. Atomic positions obtained from refinement of the neutron scattering data and from three different DFT methodologies are in excellent agreement. Normal modes and INS spectra are calculated within the harmonic approximation using the direct cell finite displacement technique. DFT affords a reliable description of intramolecular and intermolecular interactions with the result that the vibrational spectra are well reproduced by all calculations. The advantage over traditional ab initio, single molecule calculations is the improved description of the low frequency vibrations that are influenced by intermolecular interactions. No refinement of force constants has been undertaken. This structural and vibrational analysis is discussed in the context of optical work in durene host lattices. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Univ Grenoble 1, Spectrometrie Phys Lab, CNRS UMR 5588, F-38402 St Martin Dheres, France. Univ London Imperial Coll Sci Technol & Med, Dept Chem, London SW7 2AY, England. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Delft Univ Technol, Infacultair Reactor Inst, NL-2629 JB Delft, Netherlands. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Autonoma Madrid, Dept Fis Mat Condensada, E-28049 Madrid, Spain. CSIC, Inst Ciencia Mat Barcelona, E-08193 Barcelona, Spain. Univ Basque Country, Dept Fis Aplicada 2, E-48080 Bilbao, Spain. RP Johnson, MR (reprint author), Inst Max Von Laue Paul Langevin, BP 156, F-38042 Grenoble 9, France. EM johnson@ill.fr RI Garcia, Alberto/A-7460-2008; yildirim, taner/A-1290-2009; Sanchez-Portal, Daniel /E-5858-2010; Gale, Julian/B-7987-2009; Soler, Jose/B-6253-2008; Ordejon, Pablo/D-3091-2014; Fernandez-Diaz, Maria Teresa/D-7373-2014; Artacho, Emilio/G-2616-2015 OI Garcia, Alberto/0000-0001-5138-9579; Gale, Julian/0000-0001-9587-9457; Soler, Jose/0000-0003-1046-7221; Ordejon, Pablo/0000-0002-2353-2793; Artacho, Emilio/0000-0001-9357-1547 NR 53 TC 39 Z9 39 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 EI 1873-4421 J9 CHEM PHYS JI Chem. Phys. PD NOV 1 PY 2000 VL 261 IS 1-2 SI SI BP 189 EP 203 DI 10.1016/S0301-0104(00)00229-9 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 368MT UT WOS:000090121700015 ER PT J AU Yildirim, T AF Yildirim, T TI Structure and dynamics from combined neutron scattering and first-principles studies SO CHEMICAL PHYSICS LA English DT Article DE neutron scattering; first-principles methods; structure and dynamics; solid cubane; protonic conductors ID SOLID CUBANE AB Using combined first-principles and neutron-scattering techniques, we have studied the structural and dynamical properties of several materials including solid cubane and protonic-conducting oxides. The measured lattice parameters, atomic positions, and vibrational densities-of-states are compared with those obtained from first-principles calculations. In most cases, good agreement was obtained, even for systems as diverse as molecular solids and oxides. In particular, using the van der Waals solid cubane, we tested density functional theory within the local density approximation (LDA) and the generalized gradient approximation (GGA). While calculations within the LDA are in good agreement with the experimental data, GGA calculations predict too large a lattice constant and too small a cohesive energy for solid cubane. (C) 2000 Published by Elsevier Science B.V. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Yildirim, T (reprint author), NIST, Ctr Neutron Res, Bldg 235,Room E112, Gaithersburg, MD 20899 USA. EM taner@nist.gov RI yildirim, taner/A-1290-2009 NR 22 TC 42 Z9 43 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 EI 1873-4421 J9 CHEM PHYS JI Chem. Phys. PD NOV 1 PY 2000 VL 261 IS 1-2 SI SI BP 205 EP 216 DI 10.1016/S0301-0104(00)00231-7 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 368MT UT WOS:000090121700016 ER PT J AU Hoffmeister, D Ichinose, K Domann, S Faust, B Trefzer, A Drager, G Kirschning, A Fischer, C Kunzel, E Bearden, DW Rohr, J Bechthold, A AF Hoffmeister, D Ichinose, K Domann, S Faust, B Trefzer, A Drager, G Kirschning, A Fischer, C Kunzel, E Bearden, DW Rohr, J Bechthold, A TI The NDP-sugar co-substrate concentration and the enzyme expression level influence the substrate specificity of glycosyltransferases: cloning and characterization of deoxysugar biosynthetic genes of the urdamycin biosynthetic gene cluster SO CHEMISTRY & BIOLOGY LA English DT Article DE deoxysugar biosynthesis; glycosyltransferase; D-olivose; L-rhodinose; urdamycin ID SACCHAROPOLYSPORA-ERYTHRAEA; STREPTOMYCES-FRADIAE; ESCHERICHIA-COLI; INACTIVATION; ANTIBIOTICS; PRODUCTS; HYBRID; DNA AB Background: Streptomyces fradiae is the principal producer of urdamycin A. The antibiotic consists of a polyketide-derived aglycone, which is glycosylated with four sugar components, 2X D-olivose (first and last sugar of a C-glycosidically bound trisaccharide chain at the g-position), and 2 x L-rhodinose (in the middle of the trisaccharide chain and at the 12b-position). Limited information is available about both the biosynthesis of D-olivose and L-rhodinose and the influence of the concentration of both sugars on urdamycin biosynthesis. R Results: To further investigate urdamycin biosynthesis, a 5.4 kb section of the urdamycin biosynthetic gene cluster was sequenced. Five new open reading frames (ORFs) (urdZ3, urdQ, urdR, urdS, urdT) could be identified each one showing significant homology to deoxysugar biosynthetic genes. We inactivated four of these newly allocated ORFs (urdZ3, urdQ, urdR, urdS) as well as urdZ1, a previously found putative deoxysugar biosynthetic gene. Inactivation of urdZ3, urdQ and urdZ1 prevented the mutant strains from producing L-rhodinose resulting in the accumulation of mainly urdamycinone B. Inactivation of urdR led to the formation of the novel urdamycin M, which carries a C-glycosidically attached D-rhodinose at the 9-position. The novel urdamycins N and O were detected after overexpression of urdGT1c in two different chromosomal urdGT1c deletion mutants. The mutants lacking urdS and urdQ accumulated Various known diketopiperazines. Conclusions: Analysis of deoxysugar biosynthetic genes of the urdamycin biosynthetic gene cluster revealed a widely common biosynthetic pathway leading to D-olivose and L-rhodinose. Several enzymes responsible for specific steps of this pathway could be assigned. The pathway had to be modified compared to earlier suggestions. Two glycosyltransferases normally involved in the C-glycosyltransfer of D-olivose at the 9-position (UrdGT2) and in conversion of 100-2 to urdamycin G (UrdGT1c) show relaxed substrate specificity for their activated deoxysugar co-substrate and their alcohol substrate, respectively. They can transfer activated D-rhodinose (instead of D-olivose) to the B-position, and attach L-rhodinose to the 4A-position normally occupied by a D-olivose unit, respectively. C1 Univ Kiel, D-24118 Kiel, Germany. Univ Tokyo, Grad Sch Pharmaceut Sci, Bunkyo Ku, Tokyo 1130033, Japan. Tech Univ Clausthal, Inst Organ Chem, D-38678 Clausthal Zellerfeld, Germany. Med Univ S Carolina, Dept Pharmaceut Sci, Charleston, SC 29425 USA. Natl Ocean Serv, NOAA, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Bechthold, A (reprint author), Univ Kiel, Gutenbergstr 76, D-24118 Kiel, Germany. RI Rohr, Jurgen/G-5375-2014 OI Rohr, Jurgen/0000-0001-6447-5951 NR 37 TC 76 Z9 80 U1 1 U2 7 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD NOV PY 2000 VL 7 IS 11 BP 821 EP 831 DI 10.1016/S1074-5521(00)00029-6 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 376NR UT WOS:000165464100002 PM 11094336 ER PT J AU Jansen, WA AF Jansen, WA TI Countermeasures for mobile agent security SO COMPUTER COMMUNICATIONS LA English DT Article DE mobile agents; computer security; countermeasures AB Security is an important issue for the widespread deployment of applications based on software agent technology. It is generally agreed that without the proper countermeasures in place, use of agent-based applications will be severely impeded. However, not all applications require the same set of countermeasures, nor can they depend entirely on the agent system to provide them. Instead, countermeasures are applied commensurate with the anticipated threat profile and intended security objectives for the application. While countermeasures typically include any action, device, procedure, technique, or other measure that reduces the vulnerability of or threat to a system, our focus here is specifically on technical mechanisms, as opposed to procedural or non-technical measures. Such countermeasures can be integrated directly into an agent system, or incorporated into the design of an agent to supplement the capabilities of an underlying agent system. This paper gives an overview of the threats associated with software agent systems and their technical countermeasures, including the strengths and weaknesses of the techniques involved. Emphasis is on mobile software agents, since they typically face a more severe set of threats than do static agents and, therefore, demand more rigorous countermeasures. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jansen, WA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 36 TC 44 Z9 60 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD NOV 1 PY 2000 VL 23 IS 17 BP 1667 EP 1676 DI 10.1016/S0140-3664(00)00253-X PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 368ME UT WOS:000090120100011 ER PT J AU Casas, AM Cortes, AL Maestro, A Soriano, MA Riaguas, A Bernal, J AF Casas, AM Cortes, AL Maestro, A Soriano, MA Riaguas, A Bernal, J TI LINDENS: A program for lineament length and density analysis SO COMPUTERS & GEOSCIENCES LA English DT Article DE lineament; density map; directional analysis; satellite images; Duero Basin; Fortran ID EBRO BASIN; IMAGERY; SPAIN AB Analysis of lineaments from satellite images normally includes the determination of their orientation and density. The spatial variation in the orientation and/or number of lineaments must be obtained by means of a network of cells, the lineaments included in each cell being analysed separately. The program presented in this work, LINDENS, allows the density of lineaments (number of lineaments per km(2) and length of lineaments per km2) to be estimated. It also provides a tool for classifying the lineaments contained in different cells, so that their orientation can be represented in frequency histograms and/or rose diagrams. The input file must contain the planar coordinates of the beginning and end of each lineament. The density analysis is done by creating a network of square cells, and counting the number of lineaments that are contained within each cell, that have one of their ends within the cell or that cross-cut the cell boundary. The lengths of lineaments are then calculated. To obtain a representative density map the cell size must be fixed according to: (1) the average lineament length; (2) the distance between the lineaments; and (3) the boundaries of zones with low densities due to lithology or outcrop features. An example from the Neogene Duero Basin (Northern Spain) is provided to test the reliability of the density maps obtained with different cell sizes. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Zaragoza, Fac Ciencias, Dept Geol, E-50009 Zaragoza, Spain. Univ Zaragoza, Dept Didact Ciencias Expt, E-50009 Zaragoza, Spain. Univ Zaragoza, Dept Matemat Aplicada, E-50009 Zaragoza, Spain. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Casas, AM (reprint author), Univ Zaragoza, Fac Ciencias, Dept Geol, E-50009 Zaragoza, Spain. RI Soriano, Maria Asuncion/H-3422-2012; Maestro, Adolfo/K-2434-2014; Casas, Antonio/L-5751-2014; OI Maestro, Adolfo/0000-0002-7474-725X; Casas, Antonio/0000-0003-3652-3527; Riaguas, Andres/0000-0001-6097-1202; Cortes Gracia, Angel Luis/0000-0002-7075-9683 NR 12 TC 27 Z9 27 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-3004 J9 COMPUT GEOSCI-UK JI Comput. Geosci. PD NOV-DEC PY 2000 VL 26 IS 9-10 BP 1011 EP 1022 DI 10.1016/S0098-3004(00)00017-0 PG 12 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA 362XU UT WOS:000089804200003 ER PT J AU Esler, D Bowman, TD Dean, TA O'Clair, CE Jewett, SC McDonald, LL AF Esler, D Bowman, TD Dean, TA O'Clair, CE Jewett, SC McDonald, LL TI Correlates of Harlequin Duck densities during winter in Prince William Sound, Alaska SO CONDOR LA English DT Article DE density; Exxon Valdez oil spill; food; habitat; Harlequin Duck; Histrionicus histrionicus; population recovery ID EXXON-VALDEZ OIL; SURVIVAL; SPILL; BIRDS; SIZE; FOOD AB We evaluated relationships of Harlequin Duck (Histrionicus histrionicus) densities to habitat attributes, history of habitat contamination by the 1989 Exxon Valdez oil spill, and prey biomass density and abundance during winters 1995-1997 in Prince William Sound, Alaska. Habitat features that explained variation in duck densities included distance to streams and reefs, degree of exposure to wind and wave action, and dominant substrate type. After accounting for these effects, densities were lower in oiled than unoiled areas, suggesting that population recovery from the oil spill was not complete, due either to lack of recovery from initial oil spill effects or continuing deleterious effects. Prey biomass density and abundance were not strongly related to duck densities after accounting for habitat and area effects. Traits of Harlequin Ducks that reflect their affiliation with naturally predictable winter habitats, such as strong site fidelity and intolerance of increased energy costs, may make their populations particularly vulnerable to chronic oil spill effects and slow to recover from population reductions, which may explain lower densities than expected on oiled areas nearly a decade following the oil spill. C1 US Geol Survey, Alaska Biol Sci Ctr, Anchorage, AK 99503 USA. US Fish & Wildlife Serv, Anchorage, AK 99503 USA. Coastal Resources Assoc Inc, Vista, CA 92083 USA. Natl Oceanog & Atmospher Adm, Auke Bay Lab, Juneau, AK 99801 USA. Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. Western Ecosyst Technol Inc, Cheyenne, WY 82001 USA. RP Esler, D (reprint author), US Geol Survey, Alaska Biol Sci Ctr, 1011 E Tudor Rd, Anchorage, AK 99503 USA. NR 29 TC 17 Z9 17 U1 2 U2 3 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0010-5422 J9 CONDOR JI Condor PD NOV PY 2000 VL 102 IS 4 BP 920 EP 926 DI 10.1650/0010-5422(2000)102[0920:COHDDD]2.0.CO;2 PG 7 WC Ornithology SC Zoology GA 376NV UT WOS:000165464400023 ER PT J AU Tucker, JB Rao, MV Holland, OW Chi, PH Braga, GCB Freitas, JA Papanicolaou, N AF Tucker, JB Rao, MV Holland, OW Chi, PH Braga, GCB Freitas, JA Papanicolaou, N TI Material and n-p junction characteristics of As- and Sb-implanted SiC SO DIAMOND AND RELATED MATERIALS LA English DT Article DE SiC; ion-implantation; arsenic; antimony ID HIGH-POWER DEVICES; SILICON-CARBIDE; ION-IMPLANTATION; NITROGEN IMPLANTS; EPITAXIAL LAYERS; ACTIVATION; PHOTOLUMINESCENCE; SIMULATION; BEHAVIOR; DEFECTS AB Single and multiple energy As and Sb implantations were performed into p-type 6H-SiC epitaxial layers at room temperature (RT) and 800 degreesC. Secondary ion mass spectrometry measurements showed severe implant loss for annealing temperatures > 1500 degreesC. Rutherford backscattering spectroscopy/channeling (RBS/C) measurements indicated a high degree of residual lattice damage for RT implantations even after 1600 degreesC annealing while less damage was detected in 800 degreesC implanted samples. Electrical activations (ratios of sheet carrier concentrations to implant doses) of 11 and 20% were measured for 800 degreesC As and Sb implantations annealed at 1500 degreesC, respectively. The Schottky capacitance-voltage profiling measurements indicated substitutional concentrations in the low 10(18) cm(-3) range for both As and Sb. Based on the experimental data, carrier ionization energies of 130 and 88 meV were estimated for As and Sb donors, respectively. Vertical n-p junction diodes were made by using multiple energy As and Sb implanted epitaxial layers Elevated temperature As implanted diodes exhibited a room temperature reverse leakage current of approximate to 8 x 10 A/cm(2) with no passivation at - 100 V bias and a forward series resistance of 460 Ohm. (C) 2000 Elsevier Science B.V. All rights reserved. C1 George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. RP Rao, MV (reprint author), George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. NR 43 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD NOV PY 2000 VL 9 IS 11 BP 1887 EP 1896 DI 10.1016/S0925-9635(00)00340-X PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 371RC UT WOS:000165191100009 ER PT J AU Meyer, CG Holland, KN Wetherbee, BM Lowe, CG AF Meyer, CG Holland, KN Wetherbee, BM Lowe, CG TI Movement patterns, habitat utilization, home range size and site fidelity of whitesaddle goatfish, Parupeneus porphyreus, in a marine reserve SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE coral reef fishes; diel behavior patterns; acoustic telemetry; remote monitoring; hardwired array; management tools ID FISHERIES CONSERVATION ZONE; MANAGEMENT; FRENCH; GRUNTS; HAWAII AB Suitability of small (< 1 km(2)) marine reserves for protecting a commercially important endemic Hawaiian goatfish, Parupeneus porphyreus, was examined by quantifying goatfish habitat use, home range size and site fidelity in an existing marine reserve (Coconut Island in Kaneohe Bay, Hawaii). Five goatfish equipped with acoustic transmitters were tracked for up to 93 h each over 3-14 days. Daytime habitat use patterns of two of these fish were continuously monitored for one month using a fixed hydrophone hardwired to an onshore computer. Acoustically tagged fish showed consistent diel patterns of behavior, refuging in holes in the reef by day and moving over extensive areas of sand and coral rubble habitat at night. Remote monitoring of daytime habitat use by two goatfish revealed that the same daytime refuge was used by both fish for at least one month (the battery life of the transmitters). Home ranges of all fish were within the boundaries of the Coconut Island reserve suggesting that even small areas containing suitable habitat can make effective reserves for this species. A relatively low abundance of reproductive size P. porphyreus at Coconut Island in comparison with deeper areas may indicate an ontogenetic shift to deeper habitat in this species. C1 Univ Hawaii Manoa, Dept Zool, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Hawaii Inst Marine Biol, Kaneohe, HI 96744 USA. NOAA, Natl Marine Fisheries Serv, NESC, Narragansett, RI 02882 USA. Calif State Univ Long Beach, Long Beach, CA 90840 USA. RP Meyer, CG (reprint author), Univ Hawaii Manoa, Dept Zool, Edmonson Hall, Honolulu, HI 96822 USA. NR 26 TC 98 Z9 101 U1 4 U2 37 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 NOV PY 2000 VL 59 IS 3 BP 235 EP 242 DI 10.1023/A:1007664813814 PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 365YR UT WOS:000089978500001 ER PT J AU Fletcher, RA Bright, DS AF Fletcher, RA Bright, DS TI Shape factors of ISO 12103-A3 (medium test dust) SO FILTRATION & SEPARATION LA English DT Article ID SCANNING ELECTRON-MICROSCOPY; PARTICLE ANALYSIS; MACINTOSH; PROGRAM; IMAGE; SIZE AB A new derivative of Arizona sand, ISO Medium Test Dust, is coming into use for calibrating liquid optical particle counters. ISO Medium Test Dust and optical particle counters ave used to test filtering efficiency. Particle shape plays a role in both filtering and optical detection. To establish a new Standard Reference Material for the fluid power industry, the National Institute of Standards and Technology (NIST) performed scanning electron microscopy (SEM) on large numbers of medium test dust particles over the size range of 0.5-50 mum. Aspect ratio, longest chord to projected area diameter ratio, and circularity were derived from the boundaries of the SEM images. C1 NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Fletcher, RA (reprint author), NIST, Surface & Microanal Sci Div, 100 Bur Dr STOP 8371, Gaithersburg, MD 20899 USA. NR 28 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0015-1882 J9 FILTR SEPARAT JI Filtr. Sep. PD NOV PY 2000 VL 37 IS 9 BP 49 EP 56 PG 8 WC Engineering, Chemical SC Engineering GA 381ET UT WOS:000165749900008 ER PT J AU Kashiwagi, T Gilman, JW Butler, KM Harris, RH Shields, JR Asano, A AF Kashiwagi, T Gilman, JW Butler, KM Harris, RH Shields, JR Asano, A TI Flame retardant mechanism of silica gel/silica SO FIRE AND MATERIALS LA English DT Article ID POLYMERS; NANOCOMPOSITES; COMBUSTION AB Various types of silica, silica gel, fumed silicas and fused silica were added to polypropylene and polyethylene oxide to determine their flame retardant effectiveness and mechanisms. Polypropylene was chosen as a non-char-forming thermoplastic and polyethylene oxide was chosen as a polar char-forming (slight) thermoplastic. Flammability properties were measured in the cone calorimeter and the mass loss rate was measured in our radiative gasification device in nitrogen to exclude any gas phase oxidation reactions. The addition of low density, large surface area silicas, such as fumed silicas and silica gel to polypropylene and polyethylene oxide significantly reduced the heat release rate and mass loss rate. However, the addition of fused silica did not reduce the flammability properties as much as other silicas. The mechanism of reduction in flammability properties is based on the physical processes in the condensed phase instead of chemical reactions. The balance between the density and the surface area of the additive and polymer melt viscosity determines whether the additive accumulates near the sample surface or sinks through the polymer melt layer. Fumed silicas and silica gel used in this study accumulated near the surface to act as a thermal insulation layer and also to reduce the polymer concentration near the surface. However, fused silica used in this study mainly sank through the polymer melt layer and did not accumulate near the surface. The heat release and the mass loss rate of polypropylene decreased nearly proportionally with an increase in mass loading level of silica gel up to 20% mass fraction. Polyethylene oxide samples with fumed silicas and silica gel formed physically strong char/silica surface layers. This layer acted not only as thermal insulation to protect virgin polymer but also acted as a barrier against the migration of the thermal degradation products to the surface. Published in 2000 by John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Mat Fire Res Grp, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymer, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Kashiwagi, T (reprint author), Natl Inst Stand & Technol, Mat Fire Res Grp, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 16 TC 91 Z9 98 U1 2 U2 37 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 NOV-DEC PY 2000 VL 24 IS 6 BP 277 EP 289 DI 10.1002/1099-1018(200011/12)24:6<277::AID-FAM746>3.3.CO;2-1 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 397ZY UT WOS:000166730300004 ER PT J AU Polikhronidi, NG Batyrova, RG Abdulagatov, IM AF Polikhronidi, NG Batyrova, RG Abdulagatov, IM TI Isochoric heat capacity measurements of nitrogen tetroxide system at temperatures between 410 and 484 K and pressures up to 35 MPa SO FLUID PHASE EQUILIBRIA LA English DT Article DE coexistence curve; critical point; isochoric heat capacity; nitrogen tetroxide; thermodynamic properties ID CARBON-DIOXIDE; REGION AB The heat capacity of nitrogen tetroxide was measured in the temperature range from 410 to 484 K at densities between 201.21 and 980.39 kg m(-3) and for pressures up to 35 MPa using a high-temperature and high-pressure adiabatic calorimeter. The measurements were performed in the one-phase region at 17 isochores (11 liquid and 6 vapor densities) including coexistence curve and critical region. Uncertainties of the measurements are estimated to be 2%. The original temperatures and C-V data were converted to the ITS-90. The liquid and vapor one-phase isochoric heat capacities, temperatures and densities at saturation were extracted from experimental data for each measured isochore. Some of the experimental data (T-S, rho (S)), C-V along isochores and at saturation are compared with values derived from isobaric heat capacity C-P, sound velocity W, and PVT measurements. The values of critical parameters for N2O4 are measured using quasi-static thermograms method. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Phys, Dagestan Sci Ctr, Makhachkala, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 26 TC 33 Z9 33 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD NOV 1 PY 2000 VL 175 IS 1-2 BP 153 EP 174 DI 10.1016/S0378-3812(00)00457-X PG 22 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 380MD UT WOS:000165704900014 ER PT J AU Elliott, JR Rainwater, JC AF Elliott, JR Rainwater, JC TI The Bancroft point and vapor-liquid equilibria in the system benzene plus isopropanol SO FLUID PHASE EQUILIBRIA LA English DT Article DE vapor-liquid equilibria; data; vapor pressure; azeotrope; Bancroft point; equation of state ID STATE; EQUATION AB Vapor-liquid equilibria data from the literature for the system benzene + isopropanol are reviewed in detail. The data span a pressure range from 0.1 to 4.1 MPa, and indicate azeotropic behavior with the composition of the azeotrope shifting from being benzene-rich at low pressure to isopropanol-rich at high pressure. We attribute this behavior to the nature of the Bancroft point in this system and discuss the prevalence of Bancroft points in general. In a study comprising 1350 pure components, 64,103 Bancroft points were identified. (C) 2000 Published by Elsevier Science B.V. C1 Univ Akron, Dept Chem Engn, Akron, OH 44325 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Elliott, JR (reprint author), Univ Akron, Dept Chem Engn, Akron, OH 44325 USA. RI Elliott, J. Richard/K-2544-2016 NR 25 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD NOV 1 PY 2000 VL 175 IS 1-2 BP 229 EP 236 DI 10.1016/S0378-3812(00)00449-0 PG 8 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 380MD UT WOS:000165704900019 ER PT J AU Oltmans, SJ Vomel, H Hofmann, DJ Rosenlof, KH Kley, D AF Oltmans, SJ Vomel, H Hofmann, DJ Rosenlof, KH Kley, D TI The increase in stratospheric water vapor from balloonborne, frostpoint hygrometer measurements at Washington, DC, and Boulder, Colorado SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRENDS AB Stratospheric water vapor concentrations measured at two midlatitude locations in the northern hemisphere show water vapor amounts have increased at a rate of 1-1.5% yr(-1) (0.05-0.07 ppmv yr(-1)) for the past 35 years. At Washington, D.C., measurements were made from 1964-1976, and at Boulder, Colorado, observations began in 1980 and continue to the present. While these two data sets do not comprise a single time series, they individually show increases over their respective measurement periods. At Boulder the trends do not show strong seasonal differences; significant increases are found throughout the year in the altitude range 16-28 km. In winter these trends are significant down to about 13 km. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Colorado, PAOS, Boulder, CO 80309 USA. Forschungszentrum, Julich, Germany. RP Oltmans, SJ (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80305 USA. RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 23 TC 159 Z9 166 U1 1 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 NOV 1 PY 2000 VL 27 IS 21 BP 3453 EP 3456 DI 10.1029/2000GL012133 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 369JW UT WOS:000165063000005 ER PT J AU Hall, JL AF Hall, JL TI Optical frequency measurement: 40 years of technology revolutions SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article ID 1S-2S TRANSITION FREQUENCY; MODE-LOCKED LASERS; SPECTROSCOPY; COMB; WAVELENGTH; GENERATION; ION; OSCILLATOR; MICROWAVE; STABILITY C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 67 TC 27 Z9 31 U1 5 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1077-260X EI 1558-4542 J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD NOV-DEC PY 2000 VL 6 IS 6 BP 1136 EP 1144 DI 10.1109/2944.902162 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 407MP UT WOS:000167275600032 ER PT J AU Drexler, ES AF Drexler, ES TI Plastic strain in thermally cycled flip-clip PBGA solder bumps SO IEEE TRANSACTIONS ON ADVANCED PACKAGING LA English DT Article DE deformation; electron-beam moire; flip-chip PBGA; reliability; solder bumps; strain; thermal cycling ID CHIP AB Electron-beam moire, a technique to measure displacements on the sub-micrometer scale, was used to observe and calculate strain in an underfilled, flip-chip plastic ball grid array (PBGA) package. A cross section of the package, instrumented with 450-nm-pitch gratings, was thermally cycled ten times between -55 and 125 degreesC. During cycling, solder bumps were observed and digital images collected from the edge, from an area one quarter of the way across, and from near the midpoint of the Si chip. A comparison of these images with respect to the initial, no-load condition revealed the change in the moire fringe field due to the thermal. load, and the change due to the coefficient of thermal expansion mismatch among the contained materials that resulted in plastic deformation. Data from the images were analyzed to produce plots of displacement versus position from line traces through the observed solder bumps. The slopes of the plots from the data generated within the solder bump define the average strain in the solder bump. Strains mere calculated in the solder bumps at room temperature, at -55 degreesC, and at 125 degreesC during each thermal cycle. The initial high-temperature strain, out of the plane elf the Si chip, was greater for the inner solder bumps than for the solder bump at the edge of the chip. The magnitude of the initial low-temperature compressive strain was greater at the edge of the chip than in the interior of the Si chip. It was also found that for the in-plane strains, the solder bump was put into compression both at high and low temperatures. The expansion of the underfill and solder mask at high temperature was so great that they exerted a compressive force on the solder bumps. Strain in the solder bumps changed with subsequent thermal cycles. The strains decreased in value with increasing number of thermal cycles, particularly at the edge of the chip. By the 10th thermal cycle the solder bump at the edge remained in compression even at 125 degreesC. Also, the final room-temperature images showed the solder bumps in all three measured locations to be in a state of permanent compression with respect to the initial, no-load images. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Drexler, ES (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. NR 14 TC 5 Z9 5 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1521-3323 J9 IEEE TRANS ADV PACK JI IEEE Trans. Adv. Packag. PD NOV PY 2000 VL 23 IS 4 BP 646 EP 651 DI 10.1109/6040.883754 PG 6 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 373QD UT WOS:000165299400009 ER PT J AU Baum, E Irisov, V AF Baum, E Irisov, V TI Modulation of microwave radiance by internal waves: Critical point modeling of ocean observations SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE internal waves; microwave; ocean ID RADIATION; SURFACE AB Microwave polarimetric radiance measurements of the ocean surface have revealed some characteristic modulations in response to strong internal waves. This paper demonstrates that the major features of these modulations are all consistent with a model that evaluates the response of radiance to the modulation of surface roughness. This is a two-scale model that divides the spectrum of unresolved waves into a short and a long wavelength domain. The short wave "critical point" model, which evaluates resonant interactions occurring when the surface roughness scale and microwave wavelengths are comparable, is based on the solution of Gershenzon et al., [7] to the simpler problem of determining the effect on the emissivity of a monochromatic wave propagating in direction phi with respect to the incidence plane. The model of the response of radiance to the modulation of long unresolved waves uses the Kirchhoff approximation and Gaussian slope probability function (PDF), This second contribution to the radiance modulation is not significant with respect to the dominant features of the observations, but it could contribute to some of the more subtle features. C1 TRW Space & Elect Grp, Redondo Beach, CA 90278 USA. NOAA, Environm Res Lab, Boulder, CO 80303 USA. RP Baum, E (reprint author), TRW Space & Elect Grp, Redondo Beach, CA 90278 USA. NR 16 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD NOV PY 2000 VL 38 IS 6 BP 2455 EP 2464 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 377AQ UT WOS:000165490100002 ER PT J AU Harris, GR Preston, RC DeReggi, AS AF Harris, GR Preston, RC DeReggi, AS TI The impact of piezoelectric PVDF on medical ultrasound exposure measurements, standards, and regulations SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Review ID MEMBRANE HYDROPHONE PERFORMANCE; SHOCK-WAVE LITHOTRIPTER; POLYMER FILM HYDROPHONE; BROAD-BAND PIEZO; POLARIZATION DISTRIBUTION; POLYVINYLIDENE FLUORIDE; PRESSURE DETERMINATION; DIAGNOSTIC ULTRASOUND; FREQUENCY-RESPONSE; ACOUSTIC FIELDS AB This paper describes the development of PVDF hydrophones for characterizing medical ultrasound fields. The polymer hydrophone approaches that have re suited from this work are discussed, with emphasis given to the spot-poled membrane design that has become the de facto reference device for these measurements. The various national and international standards and regulations that have followed from the successful use of PVDF hydrophones also are summarized. The works discussed encompass polymer-based hydrophones designed primarily for diagnostic and lithotripsy exposure measurements, both in water and in vivo. The advent of these hydrophones has made possible accurate and reliable measurements of exposure levels encountered in medical ultrasound and, thus, has allowed questions of ultrasound bioeffects and device safety to be addressed in a consistent and scientifically sound manner. C1 US FDA, Ctr Devices & Radiol Hlth, Rockville, MD 20850 USA. Natl Phys Lab, Ctr Mech & Acoust Metrol, Teddington TW11 0LW, Middx, England. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Harris, GR (reprint author), US FDA, Ctr Devices & Radiol Hlth, Rockville, MD 20850 USA. NR 188 TC 25 Z9 26 U1 4 U2 22 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 NOV PY 2000 VL 47 IS 6 BP 1321 EP 1335 DI 10.1109/58.883521 PG 15 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 371HE UT WOS:000165172200008 PM 18238678 ER PT J AU Morse, E Lewis, M Olsen, KA AF Morse, E Lewis, M Olsen, KA TI Evaluating visualizations: using a taxonomic guide SO INTERNATIONAL JOURNAL OF HUMAN-COMPUTER STUDIES LA English DT Article ID INFORMATION-RETRIEVAL; ALGORITHM AB Although visualizations are components of many information interfaces, testing of these visual elements is rarely undertaken except as a part of overall usability testing. For this reason, it is unclear what role, if any, visualizations actually perform. Our method involves the creation of simple visual prototypes and task sets based on a visual taxonomy which allows testing of the visualization in isolation from the rest of the system. By defining tests using a visual taxonomy rather than customary tasks from the application domain, our method circumvents the problems of restricting evaluation of newer more capable systems to only those tasks which might be accomplished with older, less capable ones. This paper will discuss methods for exhaustively testing the capabilities of a visualization by mapping from a domain-independent taxonomy of visual tasks to a specific domain, i.e. information retrieval. Experimental results are presented illustrating this approach to determining the role visualizations may play in supporting users in information-seeking environments. Our methods could easily be extended to other domains including data visualization. (C) 2000 Academic Press. C1 Univ Pittsburgh, Sch Informat Sci, Pittsburgh, PA 15260 USA. Molde Coll, N-6401 Molde, Norway. RP Morse, E (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8940, Gaithersburg, MD 20899 USA. EM morse@nist.gov; ml@sis.pitt.edu; kai.olsen@molde.no NR 22 TC 31 Z9 31 U1 2 U2 7 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1071-5819 EI 1095-9300 J9 INT J HUM-COMPUT ST JI Int. J. Hum.-Comput. Stud. PD NOV PY 2000 VL 53 IS 5 BP 637 EP 662 DI 10.1006/ijhc.2000.0412 PG 26 WC Computer Science, Cybernetics; Ergonomics; Psychology, Multidisciplinary SC Computer Science; Engineering; Psychology GA 376ZZ UT WOS:000165488600002 ER PT J AU Magee, JW AF Magee, JW TI Isochoric p-rho-T measurements for 2,2-dichloro-1,1,1-trifluoroethane (R123) at temperatures from 176 to 380 K and 1-chloro-1,2,2,2-tetrafluoroethane (R124) from 104 to 400 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE 1-chloro-1,2,2,2-tetrafluoroethane; density; 1,2-dichloro-1,1,1-trifluoroethanel; p-rho-T data; R123; R124; saturated liquid AB The p-p-T relationships were measured for 2,2-djchloro-1,1,1-trifluoroethane (R123) and 1-chloro-1,2,2,2-tetrafluoroethane (R124) by an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged from 176 to 380 K For R123 and from 104 to 400 K for R124, while pressures extended lip to 35 MPa. Measurements were conducted on compressed liquid samples. Mort published p-p-T data are in good agreement with this study. The uncertainty is 0.03 K for temperature and 0.01% for pressure at p > 3 MPa and 0.05 % at p < 3 MPa. The principal source of uncertainty is the cell volume (similar to 28.5 cm(3)), with a standard uncertainty of 0.003 cm3. When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor k = 2 and, thus, a 2-SD estimate) of the density measurements is estimated to be 0.05%. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 6 TC 5 Z9 5 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 NOV PY 2000 VL 21 IS 6 BP 1291 EP 1301 DI 10.1023/A:1006765026817 PG 11 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 426VA UT WOS:000168368000004 ER PT J AU Magee, JW AF Magee, JW TI Isochoric heat capacity measurements for 2,2-dichloro-1,1,1-trifluoroethane (R123) at temperatures from 167 to 341 K and 1-chloro-1,2,2,2-tetrafluoroethane (R124) from 94 to 341 K at pressures to 35 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE 1-chloro-1,2,2,2-tetrafluoroethan; 2,2-dichloro-1,1,1-trifluoroethane; heat capacity; R123; R124; vapor pressure ID LIQUID AB Molar hear capacities at a constant volume (C-v) of 2,2-dichloro-1,1,1-trifluoroethane (R123) and 1-chloro-1,2,2,2-tetrafluoroethane (R124) were measured with an adiabatic calorimeter. Temperatures ranged from 167 K for R123 and from 94 K for R124 to 341 K, and pressures were up to 33 MPa. Measurements were conducted an the liquid in equilibrium with its vapor and on compressed liquid samples. The samples were of a high purity, verified by chemical analysis of each fluid. For the samples, calorimetric results were obtained for two-phase (C-v((2))), saturated liquid (C sigma or C-x'), and single-phase (C-v) molar heat capacities, The C-sigma data were used to estimate vapor pressures for values less than 100 kPa by applying a thermodynamic relationship between the saturated liquid heat capacity and the temperature derivatives of the vapor pressure. Doe ro the tendency of both R123 and R124 to subcool, the triple-point temperature (T-tr) and the enthalpy of fusion (Delta H-fus) could not be measured. The principal sources of uncertainty al e the temperature rise measurement and the change-of-volume work adjustment. The expanded uncertainty (at the 2 sigma level) for C-v is estimated to be 0.7%, for C-v((2)) it is 0.5%, and for C-sigma it is 0.7%. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 12 TC 4 Z9 4 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 NOV PY 2000 VL 21 IS 6 BP 1303 EP 1320 DI 10.1023/A:1006717110887 PG 18 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 426VA UT WOS:000168368000005 ER PT J AU Magee, JW Duarte-Garza, HA AF Magee, JW Duarte-Garza, HA TI Molar heat capacity at constant volume of trifluoromethane (R23) from the triple-point temperature to 342 K at pressures to 33 MPa SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE enthalpy of fusion; heat capacity; trifluoromethane; triple point; R23; vapor pressure ID SUBATMOSPHERIC VAPOR-PRESSURES; INTERNAL-ENERGY MEASUREMENTS AB Molar heat capacities at constant volume (C, of trifluoromethane (R23) have been measured with an adiabatic calorimeter, Temperatures ranged From the triple point to 342 K, and pressures up to 33.5 MPa. Measurements were conducted on the liquid in equilibrium with its vapor and on compressed liquid and gaseous samples. The samples were of high purity, as verified by chemical analysis. Calorimetric quantities are reported for the two-phase (C-v((2))), saturated-liquid (C-sigma or C-x'), and single-phase (C-v) molar heat capacities. The C-v((2)) data were used to estimate vapor pressures for values less than 100 kPa by applying a thermodynamic relationship between the two-phase internal energy U-(2) and the temperature derivatives of the vapor pressure. The triple-point temperature and the enthalpy of fusion were also measured. The principal sources of uncertainty are the temperature rise measurement and the change-of-volume work adjustment. The expanded relative uncertainty (with a coverage factor k = 2 and thus a two-standard deviation estimate) is estimated to be 0.7% for C-v, 0.5% for C-v((2)) and 0.7% for C-sigma. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 19 TC 8 Z9 8 U1 0 U2 1 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 NOV PY 2000 VL 21 IS 6 BP 1351 EP 1372 DI 10.1023/A:1006605426791 PG 22 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 426VA UT WOS:000168368000008 ER PT J AU Kiselev, SB Ely, JF Abdulagatov, IM Magee, JW AF Kiselev, SB Ely, JF Abdulagatov, IM Magee, JW TI Crossover SAFT equation of state and thermodynamic properties of propan-1-ol SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Review DE associating fluids; critical state; crossover theory; equation of state; enthalpies; heat capacities; n-alkanols thermodynamic properties; speed of sound; vapor-liquid equilibrium ID SPHERE-CHAIN EQUATION; PENG-ROBINSON EQUATION; LENNARD-JONES FLUID; CRITICAL REGION; BINARY-MIXTURES; ASSOCIATING MOLECULES; PERTURBATION-THEORY; LIQUID DENSITIES; CUBIC EQUATION; PHASE-BEHAVIOR AB In this work we have developed a nea; equation of state (EOS;) for propan-1-ol on the basis of the crossover modification (CR) of the statistical-associating-fluid-theory (SAFT) EOS recently developed and applied to n-alkanes. The CR SAFT EOS reproduces the nonanalytical scaling laws in the asymptotic critical region and reduces to the analytical-classical SAFT EOS far av;av from the critical paint. Unlike the previous crossover EOS, the new CR SAFT EOS is based on the parametric sine model for the universal crossover function and is able to represent analytically connected van der Waals loops in the metastable fluid region. The CR SAFT EOS contains 10 system-dependent parameters and allows an accurate representation of the thermodynamic properties of propan-1-ol over a wide range thermodynamic states including the asymptotic singular behavior in the nearest vicinity of the critical paint. The EOS was tested against experimental isochoric and isobaric specific heats, speed of sound, PVT, and VLE data in and beyond the critical region. In the one-phase region, the CR SAFT equation represents the experimental values of pressure with an average absolute deviation (AAD) of less than 1% in the critical and supercritical regions and the liquid densities with an AAD of about 1%. A corresponding states principle is used for the extension of the new CR SAFT EOS for propan-1-ol to higher n-alkanols. C1 Colorado Sch Mines, Chem Engn & Petr Refining Dept, Golden, CO 80401 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Kiselev, SB (reprint author), Colorado Sch Mines, Chem Engn & Petr Refining Dept, Golden, CO 80401 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 140 TC 23 Z9 23 U1 0 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 NOV PY 2000 VL 21 IS 6 BP 1373 EP 1405 DI 10.1023/A:1006657410862 PG 33 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 426VA UT WOS:000168368000009 ER PT J AU Romanov, P Gutman, G Csiszar, I AF Romanov, P Gutman, G Csiszar, I TI Automated monitoring of snow cover over North America with multispectral satellite data SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID REFLECTANCE MODEL; IMAGERY; IDENTIFICATION; RESOLUTION; PRODUCTS; SURFACE; CLOUDS AB Current National Oceanic and Atmospheric Administration (NOAA) operational global- and continental-scale snow cover maps are produced interactively by visual analysis of satellite imagery. This snow product is subjective, and its preparation requires a substantial daily human effort. The primary objective of the current study was to develop an automated system that could provide NOAA analysts with a first-guess snow cover map and thus to reduce the human labor in the daily snow cover analysis. The proposed system uses a combination of observations in the visible, midinfrared, and infrared made by the Imager instrument aboard Geostationary Operational Environmental Satellites (GOES) and microwave observations of the Special Sensor Microwave Imager (SSM/I) aboard the polar-orbiting Defense Meteorological Satellite Program platform. The devised technique was applied to satellite data for mapping snow cover for the North American continent during the winter season of 1998/99. To assess the system performance, the automatically produced snow maps were compared with the NOAA interactive operational product and were validated against in situ land surface observations. Validation tests revealed that in 85% of cases the automated snow maps fit exactly the ground snow cover reports. Snow identification with the combination of GOES and SSM/I observations was found to be more efficient than the one based solely on satellite microwave data. Comparisons between the automated maps and the NOAA operational product have shown their good agreement in the distribution of snow covet and its area coverage. The accuracy of the automated product was found to be similar to and sometimes higher than the accuracy of the operational snow cover maps manually produced at NOAA. C1 NOAA, NESDIS, ORA, Camp Springs, MD 20746 USA. NASA Headquarters, Washington, DC USA. RP Romanov, P (reprint author), NOAA, NESDIS, ORA, WWB 712,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Romanov, Peter/F-5622-2010; Csiszar, Ivan/D-2396-2010 OI Romanov, Peter/0000-0002-2153-8307; NR 23 TC 76 Z9 82 U1 0 U2 8 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 NOV PY 2000 VL 39 IS 11 BP 1866 EP 1880 DI 10.1175/1520-0450(2000)039<1866:AMOSCO>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 378QF UT WOS:000165594500007 ER PT J AU Siu, IL Islam, MN Walker, JC AF Siu, IL Islam, MN Walker, JC TI Comparison of surface spin wave modes at Fe/MnF2 and Fe/Mn interfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SEMI-INFINITE FERROMAGNET; TEMPERATURE-DEPENDENCE; MAGNETIZATION; ANISOTROPY AB We have studied the thermal demagnetization in semi-infinite ferromagnets in Fe/MnF2 and Fe/Mn bilayers using Mossbauer spectroscopy. We find that the hyperfine field at the Fe/MnF2 interface follows a quasilinear temperature dependence, which reverts to a T-3/2 dependence further into the bulk. The region in which linear temperature dependence was observed also showed significantly higher spin canting than in the film's bulk layers. The interface in the Fe/Mn system immediately showed a T-3/2 dependence which persisted deeper into the bulk. We attribute the linear temperature behavior to surface spin wave modes created by a perpendicular surface anisotropy at the interface. This behavior diminishes farther away from the interface, until the hyperfine field goes like T-3/2 as expected for bulk, 3D spin waves. We conclude that the perpendicular surface anisotropy is much stronger at the Fe/MnF2 than the Fe/Mn interface. (C) 2000 American Institute of Physics. [S0021-8979(00)01322-0]. C1 Johns Hopkins Univ, Henry A Rowland Dept Phys & Astron, Baltimore, MD 21218 USA. RP Siu, IL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 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 NOV 1 PY 2000 VL 88 IS 9 BP 5293 EP 5295 DI 10.1063/1.1314871 PG 3 WC Physics, Applied SC Physics GA 363BL UT WOS:000089813800058 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)50021-8]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Changwon Natl Univ, Dept Met & Mat Sci, Changwon 641773, Kyungnam, South Korea. RP McMichael, RD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 19 TC 33 Z9 33 U1 0 U2 11 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 NOV 1 PY 2000 VL 88 IS 9 BP 5296 EP 5299 AR PII [S0021-8979(00)50021-8] DI 10.1063/1.1323436 PG 4 WC Physics, Applied SC Physics GA 363BL UT WOS:000089813800059 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 (vol 88, pg 3561, 2000) SO JOURNAL OF APPLIED PHYSICS LA English DT Correction C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Changwon Natl Univ, Dept Met & Mat Sci, Changwon 641773, Kyungnam, South Korea. RP McMichael, RD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McMichael, Robert/J-8688-2012 NR 2 TC 0 Z9 0 U1 0 U2 3 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 NOV 1 PY 2000 VL 88 IS 9 BP 5501 EP 5501 DI 10.1063/1.1323467 PG 1 WC Physics, Applied SC Physics GA 363BL UT WOS:000089813800095 ER PT J AU Bamford, HA Poster, DL Baker, JE AF Bamford, HA Poster, DL Baker, JE TI Henry's law constants of polychlorinated biphenyl congeners and their variation with temperature SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; STRUCTURE PROPERTY RELATIONSHIPS; AIR PARTITION-COEFFICIENTS; LAKE-SUPERIOR; AQUEOUS SOLUBILITIES; ORGANIC POLLUTANTS; WATER-INTERFACE; VAPOR-PRESSURES; CHESAPEAKE BAY; CHEMICALS AB The Henry's law constants for 26 polychlorinated biphenyl (PCB) congeners were measured using a gas-stripping apparatus at five environmentally relevant temperatures between (4 and 31) degreesC. The Henry's law constants ranged between (0.079 +/- 0.003) Pa.m(3).mol(-1) for 2,2',3,3',4,4',5,6-octachlorobiphenyl (IUPAC congener #195) at 4 degreesC and (308 +/- 29) Pa.m(3)mol(-1) for 2,2',3,3',4,5',6,6'-octachlorobiphenyl (IUPAC congener #201) at 31 degreesC. The temperature dependence of each PCB congener's Henry's law constant was modeled to calculate the enthalpy and entropy of the phase change between the gaseous and dissolved phases. For many PCB congeners, this study reports the first experimentally measured temperature variations of their Henry's law constants. The enthalpies of phase change (DeltaH(H)) ranged between (14.5 +/- 3.4) kJ.mol(-l) for 2,2',4,6,6'-pentachlorabiphenyl (IUPAC congener #104) and (167 +/- 13) kJ.mol(-l) for 2,2',3,3',4,4',5,6-octachlorobiphenyl (IUPAC congener #195). These data can be used to predict PCB congener Henry's law values within the experimental temperature range within a relative standard error of less than 10%. C1 Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, Solomons, MD 20688 USA. NIST, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Baker, JE (reprint author), Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, POB 38, Solomons, MD 20688 USA. RI Baker, Joel/A-9685-2011 OI Baker, Joel/0000-0002-9980-7781 NR 41 TC 87 Z9 87 U1 3 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 2000 VL 45 IS 6 BP 1069 EP 1074 DI 10.1021/je0000266 PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 375WC UT WOS:000165423400019 ER PT J AU Abdulagatov, IM Mursalov, BA Dvoryanchikov, VI AF Abdulagatov, IM Mursalov, BA Dvoryanchikov, VI TI Vapor-liquid-solid phase transitions in aqueous sodium sulfate and sodium carbonate from heat capacity measurements near the first critical end point. 1. Sodium sulfate SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID WATER AB Heat capacities at constant volume and composition are reported for aqueous sodium sulfate for three compositions, 1 mass %, 5 mass %, and 10 mass %, respectively, and along 19 isochores, from 250 kg .m(-3) to 1073 kg .m(-3) in the temperature range from 350 K to 670 a. In the range from 630 K to 650 K, many of these isochores display two features in the heat capacity as a function of the temperature: one peak or step when solid salt first precipitates and, on further heating, a lambda -shaped peak when the vapor- or liquid-phase disappears. In Part 2 of this paper, these features will be interpreted. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Makhachkala 367030, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 2000 VL 45 IS 6 BP 1133 EP 1138 DI 10.1021/je0001227 PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 375WC UT WOS:000165423400033 ER PT J AU Valyashko, VM Abdulagatov, IM Sengers, JMHL AF Valyashko, VM Abdulagatov, IM Sengers, JMHL TI Vapor-liquid-solid phase transitions in aqueous sodium sulfate and sodium carbonate from heat capacity measurements near the first critical end point. 2. Phase boundaries SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID EQUILIBRIA; SYSTEMS; BINARY; WATER AB The constant volume, constant composition heat capacity data for aqueous sodium sulfate show several interesting features: one peak or step when solid salt first precipitates and, on further heating, a lambda -shaped peak when the vapor- or liquid-phase disappears. These features are interpreted in terms of the solid-liquid-vapor phase diagram, and their consistency is shown with earlier PVTx, phase boundary, and three-phase data from the literature. New data, are presented on the density of liquid solutions saturated with respect to the vapor. New liquid compositions or densities supplement the three-phase data available in the literature, and new fluid densities ale reported near the critical end point. For aqueous Na2SO4, we find T-cep = (648.2 +/- 0.2) K, and for aqueous Na2CO3, T-cep = (649.0 +/- 0.2) K. The present heat capacity data, as well as recent data for aqueous sodium carbonate, have sufficient resolution to distinguish, for the first time, the temperature of the critical end points in aqueous sodium sulfate and aqueous sodium carbonate from the critical temperature of pure water, T-c = (647.1 +/- 0.1) K. C1 Russian Acad Sci, NS Kurnakov Gen & Inorgan Chem Inst, Moscow 117907, SU, Russia. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Makhachkala 367030, Dagestan, Russia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Abdulagatov, IM (reprint author), Russian Acad Sci, NS Kurnakov Gen & Inorgan Chem Inst, Moscow 117907, SU, Russia. NR 34 TC 29 Z9 30 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 2000 VL 45 IS 6 BP 1139 EP 1149 DI 10.1021/je000123z PG 11 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 375WC UT WOS:000165423400034 ER PT J AU Delworth, TL Dixon, KW AF Delworth, TL Dixon, KW TI Implications of the recent trend in the Arctic/North Atlantic oscillation for the North Atlantic thermohaline circulation SO JOURNAL OF CLIMATE LA English DT Letter ID OCEAN ATMOSPHERE MODEL; COUPLED GCM; TRANSIENT RESPONSES; GRADUAL CHANGES; GREENHOUSE-GAS; CLIMATE MODEL; TEMPERATURE; CO2 AB Most projections of greenhouse gas-induced climate change indicate a weakening of the thermohaline circulation (THC) in the North Atlantic in response to increased freshening and warming in the subpolar region. These changes reduce high-latitude upper-ocean density and therefore weaken the THC. Using ensembles of numerical experiments with a coupled ocean-atmosphere model, it is found that this weakening could be delayed by several decades in response to a sustained upward trend in the Arctic/North Atlantic oscillation during winter, such as has been observed over the last 30 years. The stronger winds over the North Atlantic associated with this trend extract more heat from the ocean, thereby cooling and increasing the density of the upper ocean and thus opposing the previously described weakening of the THC. This result is of particular importance if the positive trend in the Arctic/North Atlantic oscillation is a response to increasing greenhouse gases, as has been recently suggested. C1 Princeton Univ, GFDL, NOAA, Princeton, NJ 08542 USA. RP Delworth, TL (reprint author), Princeton Univ, GFDL, NOAA, POB 308, Princeton, NJ 08542 USA. RI Delworth, Thomas/C-5191-2014; Dixon, Keith/L-7120-2015 OI Dixon, Keith/0000-0003-3044-326X NR 22 TC 68 Z9 70 U1 0 U2 10 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 NOV 1 PY 2000 VL 13 IS 21 BP 3721 EP 3727 DI 10.1175/1520-0442(2000)013<3721:IOTRTI>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 373EP UT WOS:000165275700001 ER PT J AU Mirowski, E Leone, SR AF Mirowski, E Leone, SR TI Enhancement in the crystalline quality of palladium silicide films: multiple versus single deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE methods of crystal growth; defects in crystals; X-ray diffraction; LEED; palladium silicide ID TRANSMISSION ELECTRON-MICROSCOPY; THIN-FILMS; PD2SI FILMS; PD FILMS; INTERFACES; SI; KINETICS; SURFACE; GROWTH; TRANSFORMATION AB Alternate deposition and anneal cycles involving the deposition of 100 Angstrom of Pd metal and annealing at 350 degreesC are used to grow thick Pd2Si films on Si(1 1 1). The surface ordering and bulk crystal properties are compared to films grown by using a single deposition of 200-600 Angstrom Pd metal followed by annealing at 350 degreesC to give the same nominal Pd2Si film thickness. We observe that the surface of the multiple deposition samples remains well ordered after total depositions of 100, 400 and 600 Angstrom Pd. For the single deposition method, the onset of degradation in surface ordering is observed even at the 200 Angstrom Pd metal deposition indicating that there are Pd2Si grains ((15 A) present in the upper portion of the film. X-ray diffraction analysis reveals that the bulk structure of the multiple deposition film is single crystal in nature, while the single deposition film has a polycrystalline upper layer. Glancing angle X-ray diffraction data indicate that not only is the polycrystalline portion concentrated at the top of the film, but also the grain size may be smaller near the surface. Growth mechanisms to explain the differences between the multiple and single deposition films are explored. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 32 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 2000 VL 219 IS 4 BP 368 EP 378 DI 10.1016/S0022-0248(00)00760-0 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 369XD UT WOS:000165092300007 ER PT J AU Zhokhov, AA Emelchenko, GA Naumenko, IG Barilo, SN Khasanov, SS Zverkov, SA Lynn, JW AF Zhokhov, AA Emelchenko, GA Naumenko, IG Barilo, SN Khasanov, SS Zverkov, SA Lynn, JW TI Growth of large PrBa2Cu3O7-delta single crystals by modified TSSG method using zirconium dioxide crucibles SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE PrBa2Cu3O7-delta bulk single crystals; TSSG; structure; fast crystallization ID YBA2CU3O7-DELTA AB Bulk PrBa2Cu3O7-delta single crystals of 2.5g weight were seed-grown by modified TSSG technique using yttria stabilized zirconium dioxide crucibles. A chemical composition analysis revealed a visible yttrium substitution (from the seed and crucible material) of Pr atoms to x = 0.2-0.3 in the Pr1-xYxBa2Cu3O7-delta formula. Neutron diffraction and X-ray diffraction measurements showed the block structure of different disorientation along the [0 0 1]- and [1 0 0]-directions. FWHM of the rocking curve on (0 0 6) reflection is 0.9 degrees by neutron diffraction and 0.5 degrees by X-ray diffraction. FWHM of the rocking curve on a (200) reflection is 0.3 degrees by X-ray diffraction. The antiferromagnetic ordering of Pr magnetic moments was found at a temperature T-N = 11 K by neutron diffraction. It was attempted to change the cation distribution and to increase the c-lattice parameter in a Pr123 crystal by fast crystallization. At a cooling rate of 200 K/s the c-parameter increased from 11.68 to 11.75 Angstrom, which is insufficient for a possible appearance of superconductivity in this crystal. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Distr, Russia. Inst Solid State Phys & Semicond, Minsk 220072, Byelarus. NIST, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Emelchenko, GA (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Distr, Russia. RI Khasanov, Salavat/R-8690-2016 NR 11 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 2000 VL 219 IS 4 BP 385 EP 389 DI 10.1016/S0022-0248(00)00610-2 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 369XD UT WOS:000165092300009 ER PT J AU Xu, HHK Quinn, JB Giuseppetti, AA Eichmiller, FC AF Xu, HHK Quinn, JB Giuseppetti, AA Eichmiller, FC TI Effects of whisker-to-silica ratio on the reinforcement of dental resin composites with silica-fused whiskers SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE filler level; reinforcement mechanisms; resin composite; strength; whisker-to-silica ratio ID MECHANICAL-PROPERTIES; FIBER COMPOSITES; RESTORATIONS; INDENTATION; CONVERSION; STRENGTH; INLAY; WATER; MODEL AB Resin composites need to be strengthened to improve their performance in large stress-bearing restorations. This study aimed to reinforce composites with whiskers and to investigate the effects of the whisker:silica ratio. It was hypothesized that changing the whisker-silica ratio would affect the whisker-matrix bonding and the filler's distribution, and hence alter the composite properties. Silica particles and whiskers were mixed at various whisker:silica mass ratios, thermally fused, and combined with a dental resin at filler mass fractions of 0-65%. Whisker:silica ratio and filler level had significant effects on composite properties. At 60% filler level, the silica composite (whisker:silica = 0:1) had a flexural strength (mean = SD; n = 6) of 104 +/- 21 MPa; that at a whisker:silica ratio of 1:0 was 74 +/- 36 MPa. However that of the silica-fused whisker composite (whisker:silica = 5:1) was 210 +/- 14 MPa, compared with 109 +/- 23 MPa and 114 +/- 18 MPa of two prosthetic controls. Mixing silica with whiskers minimized whisker entanglement, improved filler distribution in the matrix, and facilitated whisker silanization and bonding to the matrix, thus resulting in substantially stronger composites. 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,Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [R29 DE12476] NR 35 TC 10 Z9 11 U1 0 U2 2 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD NOV PY 2000 VL 79 IS 11 BP 1844 EP 1849 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 400AC UT WOS:000166845600005 PM 11145353 ER PT J AU Handy, EM Rao, MV Holland, OW Chi, PH Jones, KA Derenge, MA Vispute, RD Venkatesan, T AF Handy, EM Rao, MV Holland, OW Chi, PH Jones, KA Derenge, MA Vispute, RD Venkatesan, T TI Al, B, and Ga ion-implantation doping of SiC SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE SiC; ion implantation; (Al,B,Ga implants); AlN encapsulant ID SILICON-CARBIDE; ALUMINUM IMPLANTATION; NITROGEN; BORON; ACTIVATION; PHOSPHORUS; PROFILES; DAMAGE; LAYERS; LASER AB A series of single energy Al, B, and Ga ion implants were performed in the energy range 50 keV to 4 MeV into 6H-SiC to characterize the implant depth profiles using secondary ion mass spectrometry (SIMS). From the implant depth profiles empirical formulae were developed to model the range statistics as functions of ion energy. Multiple energy implants were performed into 6H- and 4H-SiC and annealed with both AlN and graphite encapsulants to determine the ability of the encapsulants to protect the implants from out-diffusion and redistribution. Al and Ga were thermally stable, but B out-diffused even with AlN or graphite encapsulation. Electrical activation was determined by Hall and capacitance-voltage measurements. An acceptor substitutional concentration of 7 x 10(16) cm(-3) was achieved for 1 x 10(17) cm(3) Al implantation. C1 George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USA, Res Lab, SEDD, Adelphi, MD 20783 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Handy, EM (reprint author), George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. RI Venkatesan, Thirumalai/E-1667-2013 NR 34 TC 18 Z9 18 U1 0 U2 14 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 NOV PY 2000 VL 29 IS 11 BP 1340 EP 1345 DI 10.1007/s11664-000-0135-z PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 370AC UT WOS:000165099100008 ER PT J AU Horne, JK Walline, PD Jech, JM AF Horne, JK Walline, PD Jech, JM TI Comparing acoustic model predictions to in situ backscatter measurements of fish with dual-chambered swimbladders SO JOURNAL OF FISH BIOLOGY LA English DT Article DE acoustic backscatter; cyprinid; lavnun; Mirogrex terraesanctae; swimbladder; target strength ID HERRING CLUPEA-HARENGUS; GAS BUBBLE RELEASE; COD GADUS-MORHUA; TARGET-STRENGTH; LAKE KINNERET; 3-SPINED STICKLEBACKS; SCATTERING MODELS; PELAGIC FISH; ISRAEL AB Lavnun Mirogrex terraesanctae have a dual-chambered swimbladder and are the dominant fish species in Lake Kinneret, Israel. Pi-monthly acoustic assessments are used to monitor lavnun abundance but the relation between the amount of reflected sound and organism morphology is not well described. Predictions from Kirchhoff-ray mode (KRM) backscatter models show a sensitivity of echo amplitude to fish length and fish aspect. Predicted mean KRM target strengths matched maximum in situ target strength measurements of eight tethered fish within 2.5 dB at 120 kHz and within 7 dB at 420 kHz. Tilt and roll of lavnun during tethered measurements increased variance of backscatter measurements. Accurate abundance and length frequency distribution estimates cannot be obtained from in situ acoustic measurements without supplementary net samples. (C) 2000 The Fisheries Society of the British Isles. C1 Univ Washington, Cooperat Inst Limnol & Ecosyst Res, Seattle, WA 98115 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI USA. Israel Oceanog & Limnol Res, Yigal Allon Kinneret Limnol Lab, IL-14102 Tiberias, Israel. RP Horne, JK (reprint author), Univ Washington, Cooperat Inst Limnol & Ecosyst Res, 7600 Sand Point Way NE,Bldg 4, Seattle, WA 98115 USA. NR 46 TC 20 Z9 22 U1 0 U2 5 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 NOV PY 2000 VL 57 IS 5 BP 1105 EP 1121 DI 10.1006/jfbi.2000.1372 PG 17 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 377BA UT WOS:000165491000002 ER PT J AU Reardon, MR MacCrehan, WA Rowe, WF AF Reardon, MR MacCrehan, WA Rowe, WF TI Comparing the additive composition of smokeless gunpowder and its handgun-fired residues SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; criminalistics; capillary electrophoresis; compositional analysis; diphenylamine; ethyl centralite; gunpowder; gunshot residue; handgun; nitroglycerin ID ELECTROKINETIC CAPILLARY ELECTROPHORESIS; GUNSHOT RESIDUE; IDENTIFICATION; AMMUNITION AB Detecting the use of handguns via the determination of the organic additives in smokeless gunpowder residues (OGSR) presents a promising alternative to primer metal residue analysis. Compositional analysis of the gunpowder additives nitroglycerin, diphenylamine, and ethyl centralite provides information that can associate residue samples with unfired gunpowder. We evaluated the composition of seven reloading smokeless gunpowders, both in bulk and as single particles, by ultrasonic solvent extraction/capillary electrophoresis. Handgun-fired residues obtained from three common weapon calibers loaded with the known reloading powders were compared with the unfired powders. In general, the composition of the residues was similar to that found in the unfired powders. For double-base powders, comparing the ratio of the propellant (P) to the total amount of stabilizer (S) for both residue and gunpowder samples proved to be a useful measurement for identification. This P/S ratio demonstrated that the additives in the residues did not greatly change relative to the unfired powder, providing a useful indicator to aid in forensic powder and residue evaluation. C1 George Washington Univ, Dept Forens Sci, Washington, DC 20052 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP MacCrehan, WA (reprint author), 100 Bur Dr,Mailstop 8394, Gaithersburg, MD 20899 USA. NR 11 TC 29 Z9 29 U1 0 U2 12 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 NOV PY 2000 VL 45 IS 6 BP 1232 EP 1238 PG 7 WC Medicine, Legal SC Legal Medicine GA 374WY UT WOS:000165368400009 PM 11110174 ER PT J AU Sibeck, DG Kudela, K Lepping, RP Lin, R Nemecek, Z Nozdrachev, MN Phan, TD Prech, L Safrankova, J Singer, H Yermolaev, Y AF Sibeck, DG Kudela, K Lepping, RP Lin, R Nemecek, Z Nozdrachev, MN Phan, TD Prech, L Safrankova, J Singer, H Yermolaev, Y TI Magnetopause motion driven by interplanetary magnetic field variations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS BOW SHOCK; UPSTREAM PRESSURE VARIATIONS; SOLAR-WIND; MAGNETOSPHERIC RESPONSE; 3-DIMENSIONAL PLASMA; DIAMAGNETIC CAVITIES; FLUX; HOT; WAVES AB We use previously reported observations of hot flow anomalies (HFAs) and foreshock cavities to predict the characteristics of corresponding features in the dayside magnetosheath, at the magnetopause, and in the outer dayside magnetosphere. We compare these predictions with Interball 1, Magion 4, and GOES 8/GOES 9 observations of magnetopause motion on the dusk flank of the magnetosphere from 1800 UT on January 17 to 0200 UT on January 18, 1996. As the model predicts, strong (factor of 2 or more) density enhancements bound regions of depressed magnetosheath densities and/or outward magnetopause displacements. During the most prominent event, the geosynchronous spacecraft observe an interval of depressed magnetospheric magnetic field strength bounded by two enhancements. Simultaneous Wind observations indicate that the intervals of depressed magnetosheath densities and outward magnetopause displacements correspond to periods in which the east/west (By) component of the interplanetary magnetic field (IMF) decreases to values near zero rather than to variations in the solar wind dynamic pressure, the north/south component of the IMF, or the IMF cone angle. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Expt Phys, Kosice 04353, Slovakia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Charles Univ, Dept Elect & Vacuum Phys, CR-18000 Prague, Czech Republic. Moscow Space Res Inst, Moscow 117810, Russia. NOAA, Space Environm Lab, Boulder, CO 80303 USA. RP Sibeck, DG (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Sibeck, David/D-4424-2012 NR 32 TC 30 Z9 30 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-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2000 VL 105 IS A11 BP 25155 EP 25169 DI 10.1029/2000JA900109 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YX UT WOS:000165096300021 ER PT J AU Andrus, RD Stokoe, KH AF Andrus, RD Stokoe, KH TI Liquefaction resistance of soils from shear-wave velocity SO JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING LA English DT Article ID CONE PENETRATION TEST; EARTHQUAKES; CPT AB A simplified procedure using shear-wave velocity measurements for evaluating the liquefaction resistance of soils is presented. The procedure was developed in cooperation with industry, researchers, and practitioners and evolved From workshops in 1996 and 1998. It follows the general format of the Seed-Idriss simplified procedure based on standard penetration test blow count and was developed using case history data From 26 earthquakes and >70 measurement sites in soils ranging from fine sand to sandy gravel with cobbles to profiles including silty clay layers. Liquefaction resistance curves were established by applying a modified relationship between the shear-wave velocity and cyclic stress ratio for the constant average cyclic shear strain suggested by R. Dobry. These curves correctly predicted moderate to high liquefaction potential for >95% of the liquefaction case histories and are shown to be consistent with the standard penetration test based curves in sandy soils. A case study is provided to illustrate application of the procedure. Additional data are needed, particularly from denser soil deposits shaken by stronger ground motions, to further validate the simplified procedure. C1 Clemson Univ, Dept Civil Engn, Clemson, SC 29634 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Texas, Dept Civil Engn, Jennie C & Milton T Graves Chair, Austin, TX 78712 USA. RP Clemson Univ, Dept Civil Engn, Clemson, SC 29634 USA. NR 53 TC 193 Z9 212 U1 4 U2 41 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 1090-0241 EI 1943-5606 J9 J GEOTECH GEOENVIRON JI J. Geotech. Geoenviron. Eng. PD NOV PY 2000 VL 126 IS 11 BP 1015 EP 1025 DI 10.1061/(ASCE)1090-0241(2000)126:11(1015) PG 11 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA 366VW UT WOS:000090027800007 ER PT J AU Debevec, EM Gates, RB Masuda, M Pella, J Reynolds, J Seeb, LW AF Debevec, EM Gates, RB Masuda, M Pella, J Reynolds, J Seeb, LW TI SPAM (Version 3.2): Statistics program for analyzing mixtures SO JOURNAL OF HEREDITY LA English DT Article ID MIXED-STOCK FISHERIES; CHUM SALMON; DNA; POPULATIONS; MARKERS C1 Alaska Dept Fish & Game, Gene Conservat Lab, Div Commercial Fisheries, Anchorage, AK 99518 USA. Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA. DAPD, MathSoft, Seattle, WA USA. Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK USA. RP Seeb, LW (reprint author), Alaska Dept Fish & Game, Gene Conservat Lab, Div Commercial Fisheries, 333 Raspberry Rd, Anchorage, AK 99518 USA. RI Reynolds, Joel/E-1445-2011 OI Reynolds, Joel/0000-0003-4506-0501 NR 15 TC 80 Z9 90 U1 0 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD NOV-DEC PY 2000 VL 91 IS 6 BP 509 EP 510 DI 10.1093/jhered/91.6.509 PG 2 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 399NJ UT WOS:000166819000017 PM 11218094 ER PT J AU Sankar, S Dender, D Borchers, JAS Smith, DJ Erwin, RW Kline, SR Berkowitz, AE AF Sankar, S Dender, D Borchers, JAS Smith, DJ Erwin, RW Kline, SR Berkowitz, AE TI Magnetic correlations in non-percolated Co-SiO2 granular films SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd EruoConference on Magnetic Properties of Fine Particles and Their Relevance to Materials Science CY OCT 19-22, 1999 CL BARCELONA, SPAIN SP European Commiss, Minist Educ & Culture, Univ Barcelona, Vicerectorat Recerca, Univ Barcelona, Div Ciencies Exptl Math, Comiss Univ Recerca, Gen Catalunya, Univ Barcelona, Dept Fis Fonamental, Fac Fis, Grp Magnetisme Propietats Transport DE granular films; dipolar interactions; magnetic nanoparticles; magnetic correlations ID ANGLE NEUTRON-SCATTERING; INTERACTING PARTICLES; THIN-FILMS; SYSTEM; SUPERPARAMAGNETISM; MEDIA AB The zero-field-cooled state of Co-x(SiO2)(1-x) granular films was investigated with small-angle neutron scattering, low-field AC magnetic susceptibility chi>(*) over bar * (T), and magnetoresistance measurements. Films with metallic volume fraction x = 0.41, which consist of 40 Angstrom isolated particles that are superparamagnetic at room temperature, show an ordered magnetic state below 150 K consisting of 550 Angstrom correlated regions that are aligned antiferromagnetically. The ordering is attributed to dipolar interactions. The temperature for the onset of correlated behavior, obtained from SANS (faster than 10(-10) s), coincides with the frequency-independent maximum of chi'(T) for frequencies ranging from 0.1 to 1000 Hz. Furthermore, consistent with ferromagnetic correlations, the ZFC resistance is not the maximum resistance. Films with x = 0.32 exhibit evidence of magnetic interactions but no extended magnetic correlation - the magnetic correlation length corresponds to the particle size. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, Dept Phys, Ctr Magnet Recording Res, La Jolla, CA 92093 USA. Natl Inst Stand & Technol, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. RP Berkowitz, AE (reprint author), Univ Calif San Diego, Dept Phys, Ctr Magnet Recording Res, MS 0401,9500 Gilman Dr, La Jolla, CA 92093 USA. NR 35 TC 58 Z9 59 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD NOV PY 2000 VL 221 IS 1-2 BP 1 EP 9 DI 10.1016/S0304-8853(00)00391-7 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 369XK UT WOS:000165092900002 ER PT J AU Neubauer, CM Garboczi, EJ Jennings, HM AF Neubauer, CM Garboczi, EJ Jennings, HM TI The use of digital images to determine deformation throughout a microstructure - Part I - Deformation mapping technique SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SCANNING ELECTRON-MICROSCOPE; DRYING SHRINKAGE; COMPOSITES AB Materials with heterogeneous microstructures do not deform uniformly under stress (mechanical or environmental). A new deformation mapping technique (DMT), which compares digital images of microstructures of the same field of view before and after deformation occurs, is reported. Two digital images are required: a reference image, taken before deformation; and a deformed image, taken after deformation. The displacements of pixels required to match the deformed image to the reference image are computed, and these displacements are used to calculate the percent deformation in the two principal directions. Results are presented as either a deformation map, as a histogram, or as data files containing the displacements at the corner of each pixel. Comparison with exact solutions generated on a simulated microstructure shows that the accuracy of this technique is quite good. C1 Northwestern Univ, Dept Mat Sci, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Northwestern Univ, Dept Civil Engn, Evanston, IL 60208 USA. RP Neubauer, CM (reprint author), Valspar Corp, Pittsburgh, PA 15233 USA. RI Jennings, Hamlin/B-7006-2009 NR 18 TC 6 Z9 6 U1 0 U2 2 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 NOV PY 2000 VL 35 IS 22 BP 5741 EP 5749 DI 10.1023/A:1004874911909 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 369WG UT WOS:000165090300031 ER PT J AU Brown, A Tipping, RH Mate, B AF Brown, A Tipping, RH Mate, B TI Theoretical study of the collision-induced double transition CO2 (nu(3)=1)+N-2 (nu(1)=1) <- CO2 (nu(3)=0)+N-2 (nu(1)=0) at 296 K SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ABSORPTION-SPECTRA; N2-N2 PAIRS; TEMPERATURES AB A procedure is presented for the calculation of the double vibrational collision-induced absorption CO2 (v(3) = 1) + N-2 (v(1) = 1) <-- CO2 (v(3) = 0) + N-2 (v(1) = 0) on the basis of quantum lineshapes computed using an isotropic potential and dipole-induced dipole functions. The linestrengths and energies of the vibration-rotation transitions are treated explicitly for N-2, utilizing the HITRAN database for CO2. The theoretical absorption profile is compared to recent experimental results. By narrowing the width of the individual lines contributing to the overall absorption profile relative to their values determined for N-2-N-2 collision-induced absorption, excellent agreement between theory and experiment is obtained. (C) 2000 Academic Press. C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Tipping, RH (reprint author), Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RI Mate, Belen/F-1135-2016 OI Mate, Belen/0000-0002-5478-8644 NR 17 TC 3 Z9 3 U1 0 U2 4 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 NOV PY 2000 VL 204 IS 1 BP 153 EP 158 DI 10.1006/jmsp.2000.8214 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 371UY UT WOS:000165198700019 ER PT J AU Span, R Lemmon, EW Jacobsen, RT Wagner, W Yokozeki, A AF Span, R Lemmon, EW Jacobsen, RT Wagner, W Yokozeki, A TI A reference equation of state for the thermodynamic properties of nitrogen for temperatures from 63.151 to 1000 K and pressures to 2200 MPa SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE caloric properties; density; equation of state; fundamental equation; nitrogen; thermodynamic properties ID VIRIAL-COEFFICIENTS; COMPRESSED-LIQUID; CARBON-DIOXIDE; SOUND-VELOCITY; HEAT-CAPACITY; MELTING LINE; FLUID REGION; T RELATION; 12 MPA; RANGE AB A new formulation for the thermodynamic properties of nitrogen has been developed. Many new data sets have become available, including high accuracy data from single and dual-sinker apparatuses which improve the accuracy of the representation of the p rhoT surface of gaseous, liquid, and supercritical nitrogen, including the saturation states. New measurements of the speed of sound from spherical resonators yield accurate information on caloric properties in gaseous and supercritical nitrogen. Isochoric heat capacity and enthalpy data have also been published. Sophisticated procedures for the optimization of the mathematical structure of equations of state and special functional forms for an improved representation of data in the critical region were used. Constraints regarding the structure of the equation ensure reasonable results up to extreme conditions of temperature and pressure. For calibration applications, the new reference equation is supplemented by a simple but also accurate formulation, valid only for supercritical nitrogen between 250 and 350 K at pressures up to 30 MPa. The uncertainty in density of the new reference equation of state ranges from 0.02% at pressures less than 30 MPa up to 0.6% at very high pressures, except in the range from 270 to 350 K at pressures less than 12 MPa where the uncertainty in density is 0.01%. The equation is valid from the triple point temperature to temperatures of 1000 K and up to pressures of 2200 MPa. From 1000 to 1800 K, the equation was validated with data of limited accuracy. The extrapolation behavior beyond 1800 K is reasonable up to the limits of chemical stability of nitrogen, as indicated by comparison to experimental shock tube data. (C) 2001 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. C1 Ruhr Univ Bochum, Lehrstuhl Thermodynam, D-44780 Bochum, Germany. NIST, Phys & Chem Properties Div, Boulder, CO 80305 USA. Univ Idaho, Coll Engn, Ctr Appl Thermodynam Studies, Moscow, ID 83844 USA. Dupont Co Inc, Fluoro Prod Lab, Wilmington, DE 19880 USA. RP Span, R (reprint author), ALSTOM Power Technol Ltd, Segelhof 1, CH-5405 Baden, Switzerland. NR 229 TC 281 Z9 288 U1 10 U2 61 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 NOV-DEC PY 2000 VL 29 IS 6 BP 1361 EP 1433 DI 10.1063/1.1349047 PG 73 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 431CA UT WOS:000168613300001 ER PT J AU Hwang, PA Wang, DW Walsh, EJ Krabill, WB Swift, RN AF Hwang, PA Wang, DW Walsh, EJ Krabill, WB Swift, RN TI Airborne measurements of the wavenumber spectra of ocean surface waves. Part I: Spectral slope and dimensionless spectral coefficient SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GREENLAND ICE-SHEET; SHORT WATER-WAVES; DIRECTIONAL SPECTRUM; LASER ALTIMETRY; CLOVERLEAF BUOY; NUMBER SPECTRA; WIND-WAVES; FETCH; EVOLUTION; JONSWAP AB An airborne scanning lidar system acquires 3D spatial topography of ocean surface waves. From the spatial data, wavenumber spectra are computed directly. The spectral analyses of two distinctively different wave fields are presented. The first one is a quasi-steady wave field under active wind generation, and the second one is a decaying wave field following a slackening of the wind field. Subtle differences in different representations of the one-dimensional spectrum (omnidirectional, marginal, and traverse) are illustrated. The spectral properties in terms of the dimensionless spectral coefficient and spectral slope in the equilibrium range are investigated using the wavenumber spectra directly computed from the 3D topography of the ocean surface. The results are in excellent agreement with existing data. The rapid data acquisition afforded by an airborne system provides an enhanced capability for studying the spatial variation of a wave field with minimal temporal changes in the environmental forcing conditions. The data of the 3D surface topography are also ideal for the quantitative investigation of the directional properties of a random wave field. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. NASA, Goddard Space Flight Ctr, WFF, Wallops Island, VA 23337 USA. EG&G, WFF, Wallops Island, VA USA. NOAA, ETL, Boulder, CO USA. RP Hwang, PA (reprint author), USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. NR 37 TC 73 Z9 74 U1 0 U2 8 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 NOV PY 2000 VL 30 IS 11 BP 2753 EP 2767 DI 10.1175/1520-0485(2001)031<2753:AMOTWS>2.0.CO;2 PG 15 WC Oceanography SC Oceanography GA 378MQ UT WOS:000165588500008 ER PT J AU Hwang, PA Wang, DW Walsh, EJ Krabill, WB Swift, RN AF Hwang, PA Wang, DW Walsh, EJ Krabill, WB Swift, RN TI Airborne measurements of the wavenumber spectra of ocean surface waves. Part II: Directional distribution SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GREENLAND ICE-SHEET; WIND-WAVES; LASER ALTIMETRY; FETCH; EVOLUTION AB An airborne scanning lidar system acquires three-dimensional (3D) spatial topography of ocean surface waves. From the spatial data, wavenumber spectra are computed directly. The spectral properties in terms bf the spectral slope and dimensionless spectral coefficient have been verified to be in very good agreement with existing data. One of the unique features of the 3D spatial data is its exceptional directional resolution. Directional properties such as the wavenumber dependence of the directional spreading function and the evolution of bimodal development are investigated with these high-resolution, phase-resolving spatial measurements. Equations for the spreading parameters, the lobe angle, and the lobe ratio are established from the airborne scanning lidar datasets. Fourier decomposition of the measured directional distribution is presented. The directional parameters can be represented by a small number (4) of the Fourier components. The measured directional distributions are compared with numerical experiments of nonlinear wave simulations to explore the functional form of the dissipation source term. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. NASA, Goddard Space Flight Ctr, WFF, Wallops Island, VA 23337 USA. EG&G, WFF, Wallops Island, VA USA. NOAA, ETL, Boulder, CO USA. RP Hwang, PA (reprint author), USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. NR 26 TC 49 Z9 50 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD NOV PY 2000 VL 30 IS 11 BP 2768 EP 2787 DI 10.1175/1520-0485(2001)031<2768:AMOTWS>2.0.CO;2 PG 20 WC Oceanography SC Oceanography GA 378MQ UT WOS:000165588500009 ER PT J AU Wang, WM McPhaden, MJ AF Wang, WM McPhaden, MJ TI The surface-layer heat balance in the equatorial Pacific Ocean. Part II: Interannual variability SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID NINO-SOUTHERN OSCILLATION; GENERAL-CIRCULATION MODEL; TROPICAL PACIFIC; EL-NINO; SEASONAL CYCLE; WARM POOL; SATELLITE DATA; GLOBAL OCEAN; WIND STRESS; SEA-LEVEL AB The surface-layer heat balance on interannual timescales in the equatorial Pacific has been examined in order to determine the processes responsible for sea surface temperature (SST) variability associated with warm and cold phases of the ENSO cycle (El Nino and La Nina). Principal datasets include multiyear time series of surface winds, upper-ocean temperature, and velocity obtained from the Tropical Atmosphere Ocean buoy allay at four locations along the equator in the western (165 degreesE), central (170 degreesW), and eastern (140 degreesW and 110 degreesW) Pacific. A blended satellite/in situ SST product and surface heat fluxes based on the Comprehensive Ocean-Atmosphere Data Set are also used. Changes in heat storage, horizontal heal advection, and heat fluxes at the surface are estimated directly from data; vertical fluxes of heat out of the base of the mixed layer are calculated as a residual. Results indicate that all terms in the hear, balance contribute to SST change on interannual timescales, depending on location and rime period. Zonal advection is important everywhere, although relative to other processes, it is most significant in the central Pacific. The inferred vertical heat flux out of the base of the mixed layer is likewise important everywhere, especially so in the eastern equatorial Pacific where the mean thermocline is shallow. Meridional advection (primarily due to instability waves in this analysis) is a negative feedback term on SST change in the eastern equatorial Pacific, tending to counteract the development of warm and cold anomalies. Likewise, the net surface heat flux generally represents a negative feedback, tending to damp SST anomalies created by ocean dynamical processes. The implications of these results for ENSO modeling and theory are discussed. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Wang, WM (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI McPhaden, Michael/D-9799-2016 NR 58 TC 91 Z9 94 U1 1 U2 7 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 NOV PY 2000 VL 30 IS 11 BP 2989 EP 3008 DI 10.1175/1520-0485(2001)031<2989:TSLHBI>2.0.CO;2 PG 20 WC Oceanography SC Oceanography GA 378MQ UT WOS:000165588500022 ER PT J AU Tsukada, M Sato, D Endo, K Yanaga, M Currie, LA Glascock, MD Ondov, JM Han, M AF Tsukada, M Sato, D Endo, K Yanaga, M Currie, LA Glascock, MD Ondov, JM Han, M TI Determination of elements in Japanese standard soil materials by means of insturmental neutron activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB Instrumental neutron activation analysis (INAA), and inductively coupled plasma mass spectroscopy (ICP-MS) were applied to the determination of major elements and rare earth elements in Japanese Standard Soil Materials (NDG-1 to -8). Eight major elements, Al, Fe, Ti, Ca, Mg Mn, K, and Na were determined by INAA. A comparison of the data for rare earth elements obtained by INAA and ICP-MS shows that the data of the contents determined by the two different analytical methods are in fairly good agreement with each other. C1 Meiji Univ, Fac Agr, Dept Agr Chem, Kawasaki, Kanagawa 2148571, Japan. Showa Coll Pharmaceut Sci, Machida, Tokyo 1948543, Japan. Shizuoka Univ, Fac Sci, Radiochem Res Lab, Shizuoka 4228529, Japan. Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. Univ Missouri, Res Reactor Ctr, Columbia, MO 65211 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. RP Tsukada, M (reprint author), Meiji Univ, Fac Agr, Dept Agr Chem, Kawasaki, Kanagawa 2148571, Japan. OI Glascock, Michael D./0000-0003-0686-7556 NR 10 TC 5 Z9 5 U1 0 U2 1 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 NOV PY 2000 VL 246 IS 2 BP 463 EP 466 DI 10.1023/A:1006709010585 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 375EZ UT WOS:000165387700040 ER PT J AU Eppeldauer, GP Lynch, DC AF Eppeldauer, GP Lynch, DC TI Opto-mechanical and electronic design of a tunnel-trap Si radiometer SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE detector; irradiance; photocurrent; photodiode; radiant power; reference detector; responsivity; spectral response; transfer standard ID ACCURACY CRYOGENIC RADIOMETER; SPECTRAL RESPONSE; SILICON PHOTODIODES; QUANTUM-EFFICIENCY; DETECTORS; CALIBRATION; SCALE AB A transmission-type light-trap silicon radiometer has been developed to hold the NIST spectral power and irradiance responsivity scales between 406 nm and 920 nm. The device is built from replace able input apertures and tightly packed different-size silicon photodiodes. The photodiodes ave positioned in a triangular shape tunnel such that beam clipping is entirely eliminated within an 8 degrees field-of-view (FOV). A light trap is attached to the output of the radiometer to collect the transmitted radiation and to minimize the effect of ambient light. The photodiodes, selected for equal shunt resistance, are connected in parallel. The capacitance and the resultant shunt resistance of the device were measured and frequency compensations were applied in the feedback network of the photocurrent-to-voltage converter to optimize signal-, voltage-, and loop-gain characteristics. The trap radiometer can measure either dc or ac optical radiation with high sensitivity. The noise-equivalent-power of the optimized device is 47 fW in dc mode and 5.2 fW at 10 Hz chopping. The relative deviation from the cosine responsivity in irradiance mode was measured to be equal to or less than 0.02 % within 5 degrees FOV and 0.05 % at 8 degrees FOV. The trap-radiometer can transfer irradiance responsivities with uncertainties comparable to those of primary standard radiometers. Illuminance and irradiance meters, holding the SI units (candela, color- and radiance-temperature), will be calibrated directly against the transfer standard trap-radiometer to obtain improved accuracy in the base-units. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Reyer Corp, New Market, MD 21774 USA. RP Eppeldauer, GP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM george.eppeldauer@nist.gov NR 21 TC 28 Z9 28 U1 0 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 NOV-DEC PY 2000 VL 105 IS 6 BP 813 EP 828 DI 10.6028/jres.105.064 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000001 PM 27551638 ER PT J AU Itano, WM AF Itano, WM TI External-field shifts of the Hg-199(+) optical frequency standard SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE atomic polarizabilities; electric quadrupole interaction; mercury ion; optical frequency standards; Stark shift; Zeeman shift ID LASER; ION; SPECTROSCOPY; ULTRAVIOLET; LIFETIME; STATE; TRAP AB Frequency shifts of the Hg-199(+) 5d(10)6s S-2(1/2) (F = 0, M-F = 0) to 5d(9)6s(2) D-2(5/2) (F = 2, M-F = 0) electric-quadrupole transition at 282 nm due to external fields ave calculated, based on a combination of measured atomic parameters and ab initio calculations. This transition is under investigation as an optical frequency standard. The perturbations calculated ave the quadratic Zeeman shift, the scalar and tensor quadratic Stark shifts, and the interaction between an external electric field gradient and the atomic quadrupole moment. The quadrupole shift is likely to be the most difficult to evaluate in a frequency standard and may have a magnitude of about 1 Hz for a single ion in a Paul trap. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Itano, WM (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. EM itano@boulder.nist.gov NR 29 TC 127 Z9 129 U1 2 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 NOV-DEC PY 2000 VL 105 IS 6 BP 829 EP 837 DI 10.6028/jres.105.065 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000002 PM 27551639 ER PT J AU Rose, AH Wang, CM Dyer, SD AF Rose, AH Wang, CM Dyer, SD TI Round robin for optical fiber Bragg grating metrology SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE dispersion; metrology; optical fiber Bragg grating; optical fiber sensors; reflectance; relative group delay; transmittance; wavelength division multiplexing ID COHERENCE INTERFEROMETRIC MEASUREMENTS; DISPERSION AB NIST has administered the first round robin of measurements for optical fiber Bragg gratings. We compared the measurement of center wavelength, bandwidth, isolation, minimum relative transmittance, and relative group delay among several grating types in two industry groups, telecommunications and sensors. We found that the state of fiber Bragg grating metrology needs improvement in most areas. Specifically, when tunable losers ave used a filter is needed to remove broadband emissions from the laser. The linear slope of relative group delay measurements is sensitive to drift and systematic bias in the rf-modulation technique. The center wavelength measurement had a range of about 27 pm in the sensors group and is not adequate to support long-term structural monitoring applications. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Rose, AH (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM arose@boulder.nist.gov; jwang@boulder.nist.gov; sdyer@boulder.nist.gov NR 6 TC 7 Z9 8 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2000 VL 105 IS 6 BP 839 EP 866 DI 10.6028/jres.105.066 PG 28 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000003 PM 27551640 ER PT J AU Kalukin, AR Winn, B Wang, YX Jacobsen, C Levine, ZH Fu, J AF Kalukin, AR Winn, B Wang, YX Jacobsen, C Levine, ZH Fu, J TI Calibration of high-resolution X-ray tomography with atomic force microscopy SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE atomic force microscopy; scanning electron microscope; x-ray microscopy ID TRANSMISSION; MICROTOMOGRAPHY; RECONSTRUCTION; INTERCONNECT; PROJECTIONS AB For two-dimensional x-ray imaging of thin films, the technique of scanning transmission x-ray microscopy (STXM) has achieved images with feature sizes as small as 40 nm in recent years. However, calibration of three-dimensional tomographic images that are produced with STXM data at this scale has not yet been described in the scientific literature, and the calibration procedure has novel problems that have not been encountered by x-ray tomography carried out at a larger scale. In x-ray microtomography, for example, one always has the option of using optical imaging on a section of the object to verify the x-ray projection measurements. with STXM, on the other hand, the sample Features are too small to be resolved by light at optical wavelengths. This fact implies that one must rely on procedures with higher resolution, such as atomic force microscopy (AFM), for the calibration. Such procedures, however, generally depend on a highly destructive sectioning of the sample, and are difficult to interpret because they give surface information rather than depth information. In this article, a procedure for calibration is described that overcomes these limitations and achieves a calibration of an STXM tomography image with an AFM image and a scanning electron microscopy image of the same object. A Ge star-shaped pattern was imaged at a synchrotron with a scanning transmission x-ray microscope. Nineteen high-resolution projection images of 200x200 pixels were tomographically reconstructed into a three-dimensional image. Features in two-dimensional images as small as 40 nm and features as small as 80 nm in the three-dimensional reconstruction were resolved. Transverse length scales based on atomic force microscopy, scanning electron microscopy, x-ray transmission and tomographic reconstruction agreed to within 10 nm. Toward the center of the sample, the pattern thickness calculated from projection images was (51 +/- 15) nm vs (80 +/- 52) nm for tomographic reconstruction, where the uncertainties are evaluated at the level of two standard deviations. C1 Rensselaer Polytech Inst, Troy, NY 12180 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Kalukin, AR (reprint author), Eastman Kodak Co, 1447 St Paul St, Rochester, NY 14653 USA. EM kaluka2@rpi.edu; bwinn@bnl.gov; swang@xradia.com; chris.jacobsen@sunysb.edu; zlevine@nist.gov; joseph.fu@nist.gov RI Jacobsen, Chris/E-2827-2015 OI Jacobsen, Chris/0000-0001-8562-0353 NR 20 TC 1 Z9 1 U1 1 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2000 VL 105 IS 6 BP 867 EP 874 DI 10.6028/jres.105.067 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000004 PM 27551641 ER PT J AU Sims, JS Hagedorn, JG Ketcham, PM Satterfield, SG Griffin, TJ George, WL Fowler, HA am Ende, BA Hung, HK Bohn, RB Koontz, JE Martys, NS Bouldin, CE Warren, JA Feder, DL Clark, CW Filla, BJ Devaney, JE AF Sims, JS Hagedorn, JG Ketcham, PM Satterfield, SG Griffin, TJ George, WL Fowler, HA am Ende, BA Hung, HK Bohn, RB Koontz, JE Martys, NS Bouldin, CE Warren, JA Feder, DL Clark, CW Filla, BJ Devaney, JE TI Accelerating scientific discovery through computation and visualization SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE discovery science; distributed processing; immersive environments; IMPI; interoperable MPI; message passing interface; MPI; parallel processing; scientific visualization ID MULTIPLE-SCATTERING CALCULATIONS; DISSIPATIVE-PARTICLE-DYNAMICS; MOLECULAR-DYNAMICS; DENDRITIC GROWTH; MODEL; SIMULATION; BREAKDOWN; COMPLEX; MPI AB The rate of scientific discovery can be accelerated through computation and visualization. This acceleration results from the synergy of expertise, computing tools, and hardware for enabling highperformance computation, information science, and visualization that is provided by a team of computation and visualization scientists collaborating in a peer-to-peer effort with the research scientists. In the context of this discussion, high performance refers to capabilities beyond the current state of the art in desktop computing. To be effective in this arena, a team comprising a critical mass of talent, parallel computing techniques, visualization algorithms, advanced visualization hardware, and a recurring investment is required to stay beyond the desktop capabilities. This article describes, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing and visualization to accelerate condensate modeling, (2) fluid flow in porous materials and in other complex geometries, (3) flows in suspensions, (4) x-ray absorption, (5) dielectric breakdown modeling, and (6) dendritic growth in alloys. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sims, JS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 65 TC 6 Z9 6 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2000 VL 105 IS 6 BP 875 EP 894 PG 20 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000005 PM 27551642 ER PT J AU O'Brien, M Lamperti, P Williams, T Sander, T AF O'Brien, M Lamperti, P Williams, T Sander, T TI Comparison of the NIST and NPL air Kerma standards used for X-ray measurements between 10 kV and 80 kV (vol 105, pg 701, 2000) 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. Natl Phys Lab, Teddington TW11 0LW, Middx, England. RP O'Brien, M (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM michelle.obrien@nist.gov; paul.lamperti@nist.gov NR 1 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2000 VL 105 IS 6 BP 901 EP 902 DI 10.6028/jres.105.070 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 428JR UT WOS:000168459000007 PM 27551644 ER PT J AU Singh, RB Huber, AH AF Singh, RB Huber, AH TI Development of a microscale emission factor model for CO for predicting real-time motor vehicle emissions SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID CARBON-MONOXIDE EMISSIONS; AIR-QUALITY; INSPECTION AB The U.S. Environmental Protection Agency's (EPA) National Exposure Research Laboratory has initiated a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project goal is;to develop improved methods for modeling the source through the air pathway to human exposure in significant microenvironments of exposure. This paper presents the technical description of a newly developed model for CO emissions. The sensitivity analysis and evaluation of this emission model is presented in a companion paper titled "Sensitivity Analysis and Evaluation of MicroFacCO: A Microscale Motor Vehicle Emission Factor Model for CO Emissions."(1) The MOBILE models (used in the United States, except California) and EMFAC models (used in California only) used to estimate emissions are suitable for supporting mostly regional (county)-scale modeling and emission inventory because of their dependence on vehicle-miles-traveled aggregate data. These emission models are not designed to estimate real-time emissions needed for human exposure studies near roadways. A number of independent studies have found that current mobile source emission factor models are not very reliable at estimating microscale emissions and are, therefore, inappropriate for use with microscale modeling necessary to estimate human exposures near roadways. A microscale emission factor model for predicting real-world real-time motor vehicle CO emissions (MicroFacCO) has been developed. It uses available information on the vehicle fleet composition. The algorithm used to calculate emission factors in MicroFacCO is disaggregated based on the on-road vehicle fleet. The emission factors are calculated from a real-time fleet rather than from a fleet-wide average estimated by a vehicle-miles-traveled weighting of the emission factors for different vehicle classes. MicroFacCO uses the same database used to develop the MOBILE6 model. As compared with MOBILE emission models, MicroFacCO requires only a few input variables, which are necessary to characterize the real-time fleet being modeled. The main input variables required are on-road vehicle fleet, time and day of year, ambient temperature, and relative humidity. C1 US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. NOAA, Atmospher Sci Modeling Div, Air Resources Lab, Res Triangle Pk, NC 27711 USA. RP Singh, RB (reprint author), US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. NR 55 TC 9 Z9 9 U1 1 U2 5 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD NOV PY 2000 VL 50 IS 11 BP 1980 EP 1991 PG 12 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 375GF UT WOS:000165390600012 PM 11111342 ER PT J AU Lide, B Spivack, RN AF Lide, B Spivack, RN TI Advanced technology program's Information Infrastructure for Healthcare focused program: A brief history SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Review AB This review examines how a "bottom-up" model of a civilian technology program works by recounting the story of the "genesis" of the Information Infrastructure for Healthcare (IIH) focused program of the Advanced Technology Program. The IIH program began with an exchange of ideas among members of the private and public sectors (through the submission of "white papers" by members of industry, workshops conducted by the Am, and meetings among persons from both groups) to identify the technologies that are necessary for the development of a national information infrastructure in health care. What the ATP hoped to gain through this process and how the private sector responded are noted. A statistical description of the participants and a discussion of changes in the ATP review and selection process is included. C1 NIST, Adv Technol Program, Gaithersburg, MD 20899 USA. RP Spivack, RN (reprint author), NIST, Adv Technol Program, Adm Bldg,Room A303, Gaithersburg, MD 20899 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PD NOV-DEC PY 2000 VL 7 IS 6 BP 559 EP 563 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA 376LT UT WOS:000165459600006 PM 11062229 ER PT J AU Orlanski, I Gross, B AF Orlanski, I Gross, B TI The life cycle of baroclinic eddies in a storm track environment SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WAVES; DOWNSTREAM; FRONTOGENESIS; FLUXES AB The life cycle of baroclinic eddies in a controlled storm track environment has been examined by means of long model integrations on a hemisphere. A time-lagged regression that captures disturbances with large meridional velocities has been applied to the meteorological variables. This regressed solution is used to describe the life cycle of the baroclinic eddies. The eddies grow as expected by strong poleward heat fluxes at low levels in regions of strong surface baroclinicity at the entrance of the storm track, in a manner similar to that of Charney modes. As the eddies evolve into a nonlinear regime, they grow deeper by fluxing energy upward, and the characteristic westward tilt exhibited in the vorticity vanishes by rotating into a meridional tilt, in which the lower-level cyclonic vorticity center moves poleward and the upper-level center moves equatorward. This rather classical picture of baroclinic evolution is radically modified by the simultaneous development of an upper-level eddy downstream of the principal eddy. The results suggest that this eddy is an integral part of a self-sustained system here named as a couplet, such that the upstream principal eddy in its evolution fluxes energy to the upper-level downstream eddy, whereas at lower levels the principal eddy receives energy fluxes from its downstream companion but grows primarily from baroclinic sources. This structure is critically dependent on the strong zonal variations in baroclinicity encountered within the storm track environment, A second important result revealed by this analysis is the fact that the low-level vorticity centers that migrate poleward tend to follow isotachs that closely correspond to the phase speed of the eddies. It is suggested that the maximum westward momentum that the eddies deposit at lower levels corresponds to the phase velocity, a quantity that can be estimated just from the upstream conditions. The intensity and direction of propagation of these waves will determine the overall structure of the storm track. C1 Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Orlanski, I (reprint author), Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NR 24 TC 9 Z9 9 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV 1 PY 2000 VL 57 IS 21 BP 3498 EP 3513 DI 10.1175/1520-0469(2000)057<3498:TLCOBE>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 373PQ UT WOS:000165298200003 ER PT J AU Janjic, ZI AF Janjic, ZI TI Comments on "Development and evaluation of a convection scheme for use in climate models" SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Editorial Material ID ADJUSTMENT SCHEME C1 Natl Ctr Environm Predict, Camp Springs, MD USA. RP Janjic, ZI (reprint author), NOAA, Ctr Sci, WWB, Room 207,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 4 TC 135 Z9 142 U1 2 U2 7 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 NOV 1 PY 2000 VL 57 IS 21 BP 3686 EP 3686 DI 10.1175/1520-0469(2000)057<3686:CODAEO>2.0.CO;2 PG 1 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 373PQ UT WOS:000165298200013 ER PT J AU Goyette, AN Wang, YC Misakian, M Olthoff, JK AF Goyette, AN Wang, YC Misakian, M Olthoff, JK TI Ion fluxes and energies in inductively coupled radio-frequency discharges containing C2F6 and c-C4F8 SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID RF REFERENCE CELL; PLASMA; DISTRIBUTIONS; BOMBARDMENT AB We report ion energy distributions (IEDs), relative ion intensities, and absolute total ion current densities at the grounded electrode of an inductively coupled Gaseous Electronics Conference (GEC) radio-frequency (rf) reference cell for discharges generated in pure C2F6, c-C4F8, and in mixtures of each gas with Ar. These discharges contain several ions of significant intensity, with the dominant ion seldom that expected from direct ionization of the feed gas. Neither the C2F6 nor the C-C4F8 fraction in the Ar mixtures significantly influences the reactive ion composition. IEDs vary from single peaked to bimodal, the latter indicating rf modulation of the ions' energy as they traverse the plasma sheath. Elevated gas pressures and higher fractions of either C2F6 or c-C4F8 all result in comparatively broader and more bimodal IEDs. IEDs in pure c-C4F8 discharges, compared to C2F6 discharges, generally exhibit more pronounced broadening and bimodality. [S0734-2101(00)01106-4]. C1 NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Goyette, AN (reprint author), NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. NR 17 TC 26 Z9 26 U1 0 U2 0 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 NOV-DEC PY 2000 VL 18 IS 6 BP 2785 EP 2790 DI 10.1116/1.1308590 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 375FH UT WOS:000165388500020 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Effect of Zn, Mn, and Fe on Cd accumulation in phytoplankton: Implications for oceanic Cd cycling SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID NORTHEAST PACIFIC WATERS; NATURAL ORGANIC-LIGANDS; MARINE-PHYTOPLANKTON; DIATOM THALASSIOSIRA; COASTAL DIATOM; SOUTHERN-OCEAN; GROWTH-RATE; CADMIUM; ZINC; IRON AB Cd and phosphate concentrations in seawater are closely related, suggesting that Cd distributions, like those of PO(4), are controlled by algal uptake and regeneration. But the factors that control Cd levels in phytoplankton and their influence on oceanic Cd versus PO(4) relationships are poorly known. We examined the effect of important controlling factors (free ion concentrations of Cd, Zn, and Mn and Fe Limitation of growth rate) on Cd accumulation by an oceanic diatom (Thalassiosira oceanica). More Limited comparative experiments were also conducted with a coastal diatom (T. weissflogii) and an oceanic coccolithophore (Emiliania huxleyi). Cellular Cd:C ratios increased with increasing Cd ion concentrations and decreasing Zn ion concentrations in all species and with decreasing ionic Mn in the diatoms. The effects of Mn and Zn apparently are related to the uptake of Cd by the cells' Mn and Cd/Co transport systems, which an under negative feedback regulation by cellular Mn and Zn. Cd:C ratios were determined in the oceanic diatom as functions of free ion concentrations of Cd, Zn, and Mn over the oceanic range of these metal ions. The data were combined with estimates of free ion concentrations of these metals in seawater to construct models of Cd:C and Cd:P ratios in oceanic phytoplankton. The modeled Cd:P ratios showed good agreement with slopes of Cd versus P relationships in different oceanic regimes. The models suggest that the high Cd versus phosphate slopes found in iron-depleted waters of the Southern Ocean and subarctic Pacific result from unusually high levels of zinc depletion in these waters. The resulting low zinc ion concentrations induce high levels of Cd uptake by phytoplankton, yielding high algal Cd:P ratios. The heavy depletion of zinc may be linked to elevated Zn:C and Zn:P ratios in iron-limited diatoms, as observed in experiments we conducted with T. oceanica. C1 NOAA, Beaufort Lab, Beaufort, NC 28516 USA. RP Sunda, WG (reprint author), NOAA, Beaufort Lab, Beaufort, NC 28516 USA. NR 45 TC 117 Z9 118 U1 2 U2 30 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 2000 VL 45 IS 7 BP 1501 EP 1516 PG 16 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 373AW UT WOS:000165267100005 ER PT J AU Huang, WL Bu, X Nguyen, L Gammon, RH Bullister, JL AF Huang, WL Bu, X Nguyen, L Gammon, RH Bullister, JL TI Production and consumption of methyl halides in a freshwater lake SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MARINE-PHYTOPLANKTON; LABORATORY CULTURES; PACIFIC-OCEAN; BROMIDE; CHLORIDE; DEGRADATION; CHEMISTRY; SEAWATER; OZONE; RATES AB The concentrations of the methyl halides CH3Cl and CH3Br in Lake Washington and its tributary streams were measured during the period 1994-1998. Strong seasonal variation was observed. In summer, the surface mixed layer in the middle of the lake was found to be generally undersaturated for CH3Cl but consistently supersaturated for CH3Br relative to air-water gas equilibrium; meanwhile, the deep waters (z(max) = 65 m) of the summertime lake were found to be depleted to near zero levels for both compounds. In winter, the methyl halides were observed to be vertically well mixed throughout the water column and strongly undersaturated in both species. A simple mass-balance box model indicates that the wintertime lake (T = 8 degreesC) is a net sink for atmospheric methyl halides with estimated loss rates of similar to2.6-3.2 pM d(-1) for CH3Cl (1 pM = 10(-12) mol L-1) and 0.09-0.13 pM d(-1) for CH3Br, probably because of unspecified microbiological processes. In summer, the mass balance model indicates that there is a net source of CH3Br in the surface mixed layer (0.17-0.25 pM d(-1)), as required to maintain the observed strong supersaturation. However, the summer surface waters are apparently a sink for CH3Cl, (1.9-2.9 pM d(-1)), with enhanced biological production compensated by larger combined microbial and chemical sinks terms. In summer, methyl halide concentrations in the deep waters continue to decrease exponentially at the observed wintertime rate, while both production and loss rates in the surface waters are likely much faster than in winter, resulting in much shorter turnover timescales. An order-of-magnitude extrapolation of these Lake Washington methyl halide fluxes to a global source/sink from freshwater lakes implies a negligible contribution (<0.05%) with respect to the currently estimated global budgets of these gases. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. RP Bullister, JL (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. EM bullister@pmel.noaa.gov NR 45 TC 5 Z9 6 U1 0 U2 2 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 2000 VL 45 IS 7 BP 1537 EP 1545 DI 10.4319/lo.2000.45.7.1537 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 373AW UT WOS:000165267100008 ER PT J AU Tamburri, MN AF Tamburri, MN TI Chemically regulated feeding by a midwater medusa SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SELECTIVE PREDATION; PELAGIC CNIDARIANS; BEHAVIOR; RATES; PREY; CTENOPHORES; ATTRACTION; FISH; SEA AB Planktonic cnidarians are principal predators in the vast habitats between the ocean's surface and the deep-sea floor. Almost nothing is known, however, about the chemical ecology of these fragile midwater animals because of difficulties associated with collecting healthy specimens and conducting experiments in the field. With the use of a remotely operated vehicle, we found that the hydromedusa Mitrocoma cellularia is not a passive "drift-net" predator. This relatively simple gelatinous organism reacted to both the taste and smell of prey in the laboratory and in situ. Our results comprise the first definitive demonstration that a species of pelagic cnidarian responds behaviorally to chemical signals, and they lend new insight into the role of chemoreception in structuring midwater communities. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Monterey Bay Natl Marine Sanctuary, Monterey, CA 93940 USA. RP Tamburri, MN (reprint author), Monterey Bay Aquarium Res Inst, 7700 Sandholdt Rd, Moss Landing, CA 95039 USA. RI Tamburri, Mario/F-7193-2013 NR 28 TC 7 Z9 8 U1 2 U2 8 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 2000 VL 45 IS 7 BP 1661 EP 1666 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 373AW UT WOS:000165267100019 ER PT J AU Maxwell, MR Buresch, KM Hanlon, RT AF Maxwell, MR Buresch, KM Hanlon, RT TI Pattern of inheritance of microsatellite loci in the squid Loligo pealeii (Mollusca : Cephalopoda) SO MARINE BIOTECHNOLOGY LA English DT Article DE squid; microsatellites; inheritance; sexual selection; cephalopod ID MULTIPLE PATERNITY; DNA MARKERS; POPULATIONS; MOLECULES; FORBESI AB Six microsatellite loci are described for the squid Loligo pealeii. All loci exhibit some degree of allelic diversity. The pattern of inheritance was tested for 3 loci through an analysis of the filial genotypes from a female-male mating. At all 3 loci, the ratios of the filial genotypes conformed to the ratios expected by Mendelian inheritance. The hypervariable loci will be useful in studies on sexual selection in this species, whereas the relatively less variable loci will be useful to address questions of population structure. C1 Marine Biol Lab, Marine Resources Ctr, Woods Hole, MA 02543 USA. RP Maxwell, MR (reprint author), Univ Calif San Diego, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. RI Hanlon, Roger/Q-8687-2016 OI Hanlon, Roger/0000-0003-0004-5674 NR 21 TC 8 Z9 8 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1436-2228 J9 MAR BIOTECHNOL JI Mar. Biotechnol. PD NOV-DEC PY 2000 VL 2 IS 6 BP 517 EP 521 DI 10.1007/s101260000036 PG 5 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 385HF UT WOS:000165997500002 PM 14961175 ER PT J AU Downs, CA Mueller, E Phillips, S Fauth, JE Woodley, CM AF Downs, CA Mueller, E Phillips, S Fauth, JE Woodley, CM TI A molecular biomarker system for assessing the health of coral (Montastraea faveolata) during heat stress SO MARINE BIOTECHNOLOGY LA English DT Article DE coral reefs; heat stress; molecular biomarkers ID NADH-UBIQUINONE OXIDOREDUCTASE; SHOCK-PROTEIN; OXIDATIVE STRESS; PHOTOSYSTEM-II; ELEVATED-TEMPERATURES; ULTRAVIOLET-RADIATION; SCLERACTINIAN CORALS; ENDOSYMBIOTIC ALGAE; ELECTRON-TRANSPORT; ZOOXANTHELLAE AB Using a novel molecular biomaker system (MBS), we assessed the physiological status of coral (Montastraea faveolata) challenged by heat stress by assaying specific cellular and molecular parameters. This technology is particularly relevant for corals because heat stress is thought to be an essential component of coral bleaching. This phenomenon is widely believed to be responsible for coral mortality worldwide, particularly during 1997-1998. Specific parameters of coral cellular physiology were assayed using the MBS that are indicative of a nonstressed or stressed condition. The MBS distinguished the separate and combined effects of heat and light on the 2 coral symbionts, a sclerctinian coral and a dinoflagellate algae (zooxanthellae). This technology aids in the accurate diagnosis of coral condition because each parameter is physiologically well understood. Finally, the MBS technology is relatively inexpensive, easy to implement, and precise, and it can be quickly adapted to a high-throughout robotic system for mass sample analysis. C1 Envirtue Biotechnol Inc, Clayton, CA 94517 USA. NOAA, Marine Biotechnol Program, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Mote Marine Lab, Ctr Trop Res, Summerland Key, FL 33042 USA. Brevard Community Coll, Dept Sci Biol, Palm Bay, FL 32909 USA. Univ Charleston, Dept Biol, Charleston, SC 29422 USA. RP Downs, CA (reprint author), Envirtue Biotechnol Inc, 1361 Yosernite Circle, Clayton, CA 94517 USA. NR 62 TC 137 Z9 141 U1 0 U2 21 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1436-2228 J9 MAR BIOTECHNOL JI Mar. Biotechnol. PD NOV-DEC PY 2000 VL 2 IS 6 BP 533 EP 544 DI 10.1007/s101260000038 PG 12 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 385HF UT WOS:000165997500004 PM 14961177 ER PT J AU Fukuyama, AK Shigenaka, G Hoff, RZ AF Fukuyama, AK Shigenaka, G Hoff, RZ TI Effects of residual Exxon Valdez oil on intertidal protothaca staminea: Mortality, growth, and bioaccumulation of hydrocarbons in transplanted clams SO MARINE POLLUTION BULLETIN LA English DT Article DE Exxon Valdez; Alaska; oil spill; Protothaca staminea; growth; bioaccumulation ID ACCUMULATION; RELEASE; SPILL; BAY AB Effects of residual Exxon Valdez oil on the intertidal clam, Protothaca staminea, were studied using reciprocal experimental transplants of clams between unoiled and oiled sites. Individually tagged clams were transplanted in 1994 and collected in 1995 and 1996, Mortality, growth, and tissue chemistry data were collected from reference unoiled and oiled clams, clams transplanted from an oiled to unoiled site, and clams moved from an unoiled to oiled site. Greatest mortality occurred in clams originating from the oiled site. Best growth occurred in clams moved from the oiled site to the unoiled area, Largest tissue burdens of hydrocarbons occurred in oiled site clams, There was indication of depuration of hydrocarbons when oiled site clams were transplanted to the unoiled site. Clams transplanted from the unoiled site to oiled site accumulated hydrocarbons after one year. Our results indicate that residual oil, 5-6 years following the EV oil spill, affected survival and growth rates of clams. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Univ Washington, Washington Cooperat Fish & Wildlife Res Unit, Seattle, WA 98195 USA. NOAA, Hazardous Mat Response Div, Seattle, WA 98115 USA. RP Univ Washington, Sch Fisheries, POB 355020, Seattle, WA 98195 USA. EM allanf@fish.washington.edu NR 33 TC 27 Z9 29 U1 0 U2 13 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 NOV PY 2000 VL 40 IS 11 BP 1042 EP 1050 DI 10.1016/S0025-326X(00)00055-2 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 381RF UT WOS:000165776300030 ER PT J AU Campbell, CE Boettinger, WJ AF Campbell, CE Boettinger, WJ TI Transient liquid-phase bonding in the Ni-Al-B system SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID MULTIPHASE DIFFUSION COUPLES; ISOTHERMAL SOLIDIFICATION; ALLOYS; BOUNDARIES; KINETICS; METAL AB Transient liquid-phase (TLP) bonding experiments were performed using a Ni-10.3 at, pet Al alloy and a Ni-10 at. pet B filler material, and the results were compared to simulations performed using the finite-difference diffusion code, DICTRA. For the simulations, a thermodynamic assessment of the Ni-Al-B system was used to define the phase diagram and the thermodynamic factors of the diffusion coefficients. Composition-dependent diffusion mobilities were assessed for the ternary system. Predicted liquid widths as functions of time were in good agreement with the experiments. The calculated and experimental Al composition profiles agree in the matrix but not in the liquid. The simulations qualitatively predicted the observed precipitation and later dissolution of the intermetallic tau -phase (Ni20Al3B6) in the base material. This research demonstrated the potential for modeling the formation of spurious phases during TLP bonding of practical superalloy systems. C1 NIST, Gaithersburg, MD 20899 USA. RP Campbell, CE (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 37 TC 45 Z9 45 U1 5 U2 16 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 NOV PY 2000 VL 31 IS 11 BP 2835 EP 2847 DI 10.1007/BF02830355 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 375HJ UT WOS:000165393200014 ER PT J AU Marinenko, RB Roberson, S Small, JS Thorne, BB Blackburn, D Kauffman, D Leigh, S AF Marinenko, RB Roberson, S Small, JS Thorne, BB Blackburn, D Kauffman, D Leigh, S TI Preparation and certification of K-411 glass microspheres SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE automated electron probe microanalyzer particle analysis; certified standard; electron probe microanalysis; glass microspheres; NIST Standard Reference Material; particle analysis; particle standard; Standard Reference Materials (R) AB The production and characterization of NBS K-411 glass microspheres in the 2-40 mum range for certification as NIST Standard Reference Material(R) 2066 (SRM(R)) are described. Quantitative analysis and heterogeneity testing of the microspheres were done with an electron probe microanalyzer-X-ray energy dispersive spectrometry (EPMA-EDS) automated particle analysis procedure. Results for the trimmed and normalized data produced mean compositions for the elements Mg, Si, Ca, Fe, and O (calculated from stoichiometry) that are in good agreement with the certified values for the K-411 bulk glass (NBS SRM 470 Glasses for Mineral Analysis), but with uncertainties about twice as large as those for the bulk material. Differences from the bulk are attributable to microsphere geometry as well as mass and size effects. C1 NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. NIST, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Marinenko, RB (reprint author), NIST, Surface & Microanal Sci Div, 100 Bur Dr,MS 8371, Gaithersburg, MD 20899 USA. NR 16 TC 3 Z9 4 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD NOV-DEC PY 2000 VL 6 IS 6 BP 542 EP 550 DI 10.1017/S1431927600000738 PG 9 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 381BY UT WOS:000165743500003 ER PT J AU Rosenbaum, HC Brownell, RL Brown, MW Schaeff, C Portway, V White, BN Malik, S Pastene, LA Patenaude, NJ Baker, CS Goto, M Best, PB Clapham, PJ Hamilton, P Moore, M Payne, R Rowntree, V Tynan, CT Bannister, JL DeSalle, R AF Rosenbaum, HC Brownell, RL Brown, MW Schaeff, C Portway, V White, BN Malik, S Pastene, LA Patenaude, NJ Baker, CS Goto, M Best, PB Clapham, PJ Hamilton, P Moore, M Payne, R Rowntree, V Tynan, CT Bannister, JL DeSalle, R TI World-wide genetic differentiation of Eubalaena: questioning the number of right whale species SO MOLECULAR ECOLOGY LA English DT Article DE cetaceans; conservation; phylogeny; right whales; taxonomy ID MITOCHONDRIAL-DNA; HUMPBACK WHALES; BALEEN WHALES; EVOLUTIONARY SIGNIFICANCE; POPULATION-STRUCTURE; CONSERVATION; HAPLOTYPES; SEQUENCES; AUSTRALIS; GLACIALIS AB Few studies have examined systematic relationships of right whales (Eubalaena spp.) since the original species descriptions, even though they are one of the most endangered large whales. Little morphological evidence exists to support the current species designations for Eubalaena glacialis in the northern hemisphere and E. australis in the southern hemisphere. Differences in migratory behaviour or antitropical distribution between right whales in each hemisphere are considered a barrier to gene flow and maintain the current species distinctions and geographical populations. However, these distinctions between populations have remained controversial and no study has included an analysis of all right whales from the three major ocean basins. To address issues of genetic differentiation and relationships among right whales, we have compiled a database of mitochondrial DNA control region sequences from right whales representing populations in all three ocean basins that consist of: western North Atlantic E. glacialis, multiple geographically distributed populations of E. australis and the first molecular analysis of historical and recent samples of E. glacialis from the western and eastern North Pacific Ocean. Diagnostic characters, as well as phylogenetic and phylogeographic analyses, support the possibility that three distinct maternal lineages exist in right whales, with North Pacific E. glacialis being more closely related to E. australis than to North Atlantic E. glacialis. Our genetic results provide unequivocal character support for the two usually recognized species and a third distinct genetic lineage in the North Pacific under the Phylogenetic Species Concept, as well as levels of genetic diversity among right whales world-wide. C1 Amer Museum Nat Hist, Mol Systemat Lab, New York, NY 10024 USA. Wildlife Conservat Soc, Sci Resource Ctr, Bronx, NY 10460 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Ctr Coastal Studies, Provincetown, MA 02657 USA. E Coast Ecosyst, Freeport, NS B0V 1B0, Canada. American Univ, Dept Biol, Washington, DC 20016 USA. Smithsonian Inst, Natl Zool Pk, Mol Genet Lab, Washington, DC 20560 USA. McMaster Univ, Dept Biol, Hamilton, ON L8S 4K1, Canada. Inst Cetacean Res, Chuo Ku, Tokyo 1040055, Japan. Univ Auckland, Sch Biol Sci, Ecol & Evolut Grp, Auckland 1, New Zealand. Univ Pretoria, S African Museum, Mammal Res Inst, ZA-8000 Cape Town, South Africa. Natl Marine Fisheries Serv, NEFSC, Woods Hole, MA 02543 USA. New England Aquarium, Boston, MA 02110 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Whale Conservat Inst, Lincoln, MA 01773 USA. Univ Washington, Natl Marine Mammal Lab, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98115 USA. Western Australian Museum, Perth, WA 6000, Australia. RP Rosenbaum, HC (reprint author), Amer Museum Nat Hist, Mol Systemat Lab, 79th St & CPW, New York, NY 10024 USA. RI Moore, Michael/E-1707-2015; OI Moore, Michael/0000-0003-3074-6631; Schaeff, Catherine/0000-0003-3728-9402 NR 64 TC 66 Z9 74 U1 6 U2 34 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD NOV PY 2000 VL 9 IS 11 BP 1793 EP 1802 DI 10.1046/j.1365-294x.2000.01066.x PG 10 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 375MX UT WOS:000165404800010 PM 11091315 ER PT J AU Cinzano, P Falchi, F Elvidge, CD Baugh, KE AF Cinzano, P Falchi, F Elvidge, CD Baugh, KE TI The artificial night sky brightness mapped from DMSP satellite Operational Linescan System measurements SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE scattering; atmospheric effects; light pollution; site testing ID CITY LIGHTS; HUMAN-SETTLEMENTS; UNITED-STATES; POPULATION; EMISSIONS; SITES; MODEL AB We present a method to map the artificial sky brightness across large territories in astronomical photometric bands with a resolution of approximately 1 km. This is of use in quantifying the situation regarding night sky pollution, recognizing potential astronomical sites and allowing future monitoring of trends. The artificial sky brightness present in the chosen direction at a given position on the surface of the Earth is obtained by the integration of the contributions produced by every surface area in the surroundings. Each contribution is computed via detailed models for the propagation in the atmosphere of the upward light flux emitted by the area. The light flux is measured with top-of-atmosphere radiometric observations made by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System. We have applied the described method to Europe, obtaining maps of artificial sky brightness in the V and B bands. C1 Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. NOAA, Natl Geophys Data Ctr, Solar Terr Phys Div, Boulder, CO 80303 USA. RP Cinzano, P (reprint author), Univ Padua, Dipartimento Astron, Vicolo Osservatorio 5, I-35122 Padua, Italy. RI Elvidge, Christopher/C-3012-2009 NR 64 TC 68 Z9 68 U1 3 U2 16 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 1 PY 2000 VL 318 IS 3 BP 641 EP 657 DI 10.1046/j.1365-8711.2000.03562.x PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JR UT WOS:000165454900006 ER PT J AU Romero, R Doswell, CA Ramis, C AF Romero, R Doswell, CA Ramis, C TI Mesoscale numerical study of two cases of long-lived quasi-stationary convective systems over eastern Spain SO MONTHLY WEATHER REVIEW LA English DT Article ID WESTERN MEDITERRANEAN REGION; ADJUSTMENT SCHEME; MODEL; SIMULATION; RESOLUTION; DIAGNOSIS; CATALONIA; RAINFALL; EVENTS; STORMS AB A set of mesoscale numerical simulations using the Pennsylvania State University-National Center for Atmospheric Research model is used to investigate two cases of extreme precipitation over eastern Spain. Both cases (3-4 November 1987 and 20 October 1982) were characterized by quasi-stationary mesoscale convective systems that developed over the Valencia region and lasted more than 30 and 12 h, respectively. Rainfall totals in 24 h exceeded 800 mm on 3-4 November and 400 mm on 20 October at some localities of that region. The first event occurred within a weak and very stagnant synoptic pattern under a persistent easterly/northeasterly low-level jet stream impinging on the Valencian orography. In contrast, the second case involved a westward-moving surface low driven by an upper-level jet streak, which evolved along the northern edge of an upper-level cutoff low over North Africa. In both cases, the mesoscale model forecast spatial details of the precipitation field reasonably accurately, as well as capturing its long duration, but underestimated the storm total precipitation. Model output fields suggest that the development of a surface mesolow by latent heat release, as well as lee cyclogenesis induced by the Atlas Mountains, could have played an important role in both events by providing low-level convergence and enhanced upslope winds. Thus, a factor separation technique is used to explore this issue. For the event of 3-4. November 1987, latent heat is decisive for explaining the precipitation maximum over central Valencia, and the Atlas orography induces rainfall enhancement over the same zone. For the event of 20 October 1982, me latent heat release is again shown to be important, whereas the Atlas Mountains orography factor appears to inhibit rainfall. This is the first time that it has been documented that the Atlas-induced modulation of the surface pressure field is not a positive factor for heavy precipitations over eastern Spain. This exceptional case may be due to a negative interaction between the Atlas Mountains and the upper-level dynamics and frontal forcing for this event. C1 NOAA, Environm Res Lab, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Illes Balears, Dept Fis, Meteorol Grp, E-07071 Palma de Mallorca, Spain. RP Romero, R (reprint author), NOAA, Environm Res Lab, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. RI Doswell III, Charles/E-7662-2010 NR 45 TC 74 Z9 77 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 NOV PY 2000 VL 128 IS 11 BP 3731 EP 3751 DI 10.1175/1520-0493(2001)129<3731:MNSOTC>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370UT UT WOS:000165141300002 ER PT J AU Parsons, DB Shapiro, MA Miller, E AF Parsons, DB Shapiro, MA Miller, E TI The mesoscale structure of a nocturnal dryline and of a frontal-dryline merger SO MONTHLY WEATHER REVIEW LA English DT Article ID SEVERE STORM ENVIRONMENT; BOUNDARY-LAYER; CONVECTIVE STORM; OKLAHOMA DRYLINE; COLD-FRONT; COPS-91; INITIATION; EVOLUTION; SURFACE; TOPOGRAPHY AB A horizontal gradient in moisture, termed the dryline, is often detected at the surface over the southern Great Plains of the United States during the spring and early summer. The dryline exhibits distinct diurnal variations in both its movement and structure. Recent research has focused on dryline structure during the afternoon and evening, particularly showing how strong (similar to1-5 m s(-1)) ascent frequently creates an environment favorable to the initiation of convection, quite close (within similar to 10 km) to the dryline interface. To date, however, there have been very few detailed analyses of the dryline interface at night, so that the nocturnal behavior of the interface predicted by theory and numerical studies is relatively poorly evaluated. In this study, special observations taken by a Doppler lidar, serial rawinsonde ascents, and a dual-channel microwave radiometer are utilized to describe the behavior of a nocturnal dryline observed on 12-13 May 1985. The analysis presented here reveals that the mesoscale structure of the nocturnal dryline prior to the formation of deep convection is a gently sloping, slow-moving interface. The movement of the dryline at night was related to the evolution of the low-level jet within the moist air. Wavelike structures and evidence for vertical mixing were observed in the moist air as low Richardson numbers occurred below the height of the jet. The previously discussed strong ascent is largely lacking in the present nocturnal case so that the circulations inherent to an undisturbed dryline at night are far less favorable for the initiation of deep convection than in the afternoon and early evening. In the present case, severe convection developed as a weak cold front approached and merged with the nocturnal dryline and the environment rapidly destabilized. Between soundings taken 2.5 h apart, the convective available potential energy increased from 524 to 3417 J kg(-1) and the absolute value of the convective inhibition decreased from 412 to 9 J kg(-1). The vertical shear of the horizontal wind also dramatically increased with time, so that the bulk Richardson number was within values normally associated with supercell convection. The timescale of the changes in stability and in the moisture field (similar to1-2.5 h) has implications for the type of observing network needed to nowcast severe convection and for assessing the performance of research and operational numerical models. C1 Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. Natl Ocean & Atmoshper Adm, Environm Res Lab, Environm Technol Lab, Boulder, CO USA. RP Parsons, DB (reprint author), Natl Ctr Atmospher Res, Atmospher Technol Div, POB 3000, Boulder, CO 80307 USA. NR 47 TC 23 Z9 25 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 NOV PY 2000 VL 128 IS 11 BP 3824 EP 3838 DI 10.1175/1520-0493(2001)129<3824:TMSOAN>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370UT UT WOS:000165141300007 ER PT J AU Chou, CB Huang, HP AF Chou, CB Huang, HP TI Application of AVHRR data to a one-dimensional variational retrieval scheme for cloudy TOVS data SO MONTHLY WEATHER REVIEW LA English DT Article ID SATELLITE SOUNDING RADIANCES; NUMERICAL WEATHER PREDICTION; CLEARED RADIANCES; ASSIMILATION; INVERSION; SYSTEM; BUREAU; TAIWAN AB The use of the Advanced Very High Resolution Radiometer (AVHRR) data in a one-dimensional variational scheme is examined to retrieve cloud parameters and atmospheric profiles. The variational scheme used TIROS Operational Vertical Sounder radiance data for retrieval. The AVHRR data were used in the partly cloudy and cloudy cases to provide initial guesses for cloud parameters in the iterative scheme, to detect the presence of cirrus clouds, and to determine the sea surface temperature used in retrieval. Sensitivity tests showed that the error in the initial guesses of cloud parameters has substantial impact on the accuracy of the retrieved fields; this sensitivity increases with increased cloudiness. Cloud parameters deduced from AVHRR data are nearly optimal, in terms of maximizing the efficiency of convergence, as the initial guesses for the retrieval scheme. In the absence of cirrus cloud, a retrieval procedure incorporating AVHRR initial guesses produced temperature and humidity profiles for partly cloudy cases that are about as accurate as those for clear cases. In both cases the maximum improvement made in the retrieval procedure over background error was about 0.2 K in the temperature profile, and 0.05 tin logarithm of mixing ratio) in the humidity profile. For partly cloudy cases, best retrieval results were obtained for a low cloud top, or a middle cloud top bur with small cloud fraction. Cirrus cloud remains a problem, as its presence generally degrades the quality of retrieval. C1 Cent Weather Bur, Satellite Ctr, Taipei, Taiwan. NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. RP Chou, CB (reprint author), Cent Weather Bur, Satellite Ctr, 64 Kung Yuan Rd, Taipei, Taiwan. NR 19 TC 0 Z9 0 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 NOV PY 2000 VL 128 IS 11 BP 3867 EP 3878 DI 10.1175/1520-0493(2001)129<3867:AOADTA>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 370UT UT WOS:000165141300010 ER PT J AU Berman, HM Bhat, TN Bourne, PE Feng, ZK Gilliland, G Weissig, H Westbrook, J AF Berman, HM Bhat, TN Bourne, PE Feng, ZK Gilliland, G Weissig, H Westbrook, J TI The Protein Data Bank and the challenge of structural genomics SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID FILE AB The PDB has created systems for the processing, exchange, query, and distribution of data that will enable many aspects of high throughput structural genomics. C1 Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Rockville, MD 20850 USA. Univ Calif San Diego, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. Univ Calif San Diego, Dept Pharmacol, La Jolla, CA 92093 USA. Univ Maryland, Maryland Biotechnol Inst, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Berman, HM (reprint author), Rutgers State Univ, Dept Chem, 610 Taylor Rd, Piscataway, NJ 08854 USA. RI Bourne, Philip/C-2073-2008 NR 14 TC 286 Z9 292 U1 6 U2 17 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD NOV PY 2000 VL 7 SU S BP 957 EP 959 DI 10.1038/80734 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 563YQ UT WOS:000176285900012 PM 11103999 ER PT J AU Liu, PC AF Liu, PC TI Wave grouping characteristics in nearshore Great Lakes SO OCEAN ENGINEERING LA English DT Article DE wind waves; wave grouping; nearshore; Great Lakes; wavelet transform ID SIGNAL AB The recently advanced approach of wavelet transform is applied to the analysis of wave data measured in the nearshore areas of the Great Lakes. The conventional spectrum analysis of wave time series in the frequency domain can be readily generalized to the frequency and time domain using the wavelet transform. The traditional Fourier transform approach has not been able to directly assess the time localized nature of wave groups. With the application of wavelet transformation, the relatively unexplored wave grouping characteristics come to Light as the predominant feature of wave processes. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Liu, PC (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 9 TC 36 Z9 37 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0029-8018 J9 OCEAN ENG JI Ocean Eng. PD NOV PY 2000 VL 27 IS 11 BP 1221 EP 1230 DI 10.1016/S0029-8018(99)00042-6 PG 10 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 311VZ UT WOS:000086907700004 ER PT J AU Earle, MD Steele, KE Wang, DWC AF Earle, MD Steele, KE Wang, DWC TI Comments and discussion on 'Wave direction analysis from data buoys' by Min-Chih Huang and Jia-Yuan Chen SO OCEAN ENGINEERING LA English DT Article ID PITCH C1 NOAA, Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. Neptune Sci Inc, Slidell, LA USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. RP Steele, KE (reprint author), NOAA, Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. NR 10 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0029-8018 J9 OCEAN ENG JI Ocean Eng. PD NOV PY 2000 VL 27 IS 11 BP 1265 EP 1272 DI 10.1016/S0029-8018(99)00038-4 PG 8 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 311VZ UT WOS:000086907700007 ER PT J AU Im, YS Paek, EG Tang, X Choe, JY Oh, TK AF Im, YS Paek, EG Tang, X Choe, JY Oh, TK TI Experimental nonmechanical image rotation to 20 angles using an acousto-optic dove prism SO OPTICAL ENGINEERING LA English DT Article DE optical information processing; image rotation; parallel processing; pattern recognition; acousto-optic beam deflector AB An experimental demonstration of nonmechanical optical image rotation to 20 different angles is described. The optical system consists of a polygon mirror with 20 facets in a half cylinder and a 2-D acousto-optic beam deflector. Experimental details including the requirements of components are described. Various issues such as number of rotation angles, resolution, aberration, and noise are analyzed. (C) 2000 Society of Photo-Optical instrumentation Engineers. [S0091-3286(00)00411-6]. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. USN, Res Lab, Radar Div, Washington, DC 20375 USA. USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Im, YS (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 2000 VL 39 IS 11 BP 2909 EP 2914 DI 10.1117/1.1314592 PG 6 WC Optics SC Optics GA 376WH UT WOS:000165479400010 ER PT J AU Oates, CW Curtis, EA Hollberg, L AF Oates, CW Curtis, EA Hollberg, L TI Improved short-term stability of optical frequency standards: approaching 1 Hz in 1 s with the Ca standard at 657 nm SO OPTICS LETTERS LA English DT Article ID QUANTUM PROJECTION NOISE; SPECTROSCOPY; LASER AB For a neutral Ca-40-based optical frequency standard we report a fractional frequency instability of 4 x 10(-15) in 1 s, which represents a fivefold improvement over existing atomic frequency standards. Using the technique of optical Borde-Ramsey spectroscopy with a sample of 10(7) trapped atoms, we have resolved linewidths as narrow as 200 Bz (FWHM). With colder atoms this system could potentially achieve an instability as low as 2 x 10(-16) in 1 s. Such low instabilities are important for frequency standards and precision tests of fundamental physics. OCIS codes: 300.6320, 140.3320, 020.7010. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Oates, CW (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 13 TC 70 Z9 72 U1 0 U2 1 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 NOV 1 PY 2000 VL 25 IS 21 BP 1603 EP 1605 DI 10.1364/OL.25.001603 PG 3 WC Optics SC Optics GA 366CW UT WOS:000089988100013 PM 18066290 ER PT J AU Cava, RJ Yamaura, K Loureiro, S Huang, Q Erwin, RW Lynn, JW Young, D AF Cava, RJ Yamaura, K Loureiro, S Huang, Q Erwin, RW Lynn, JW Young, D TI Magnets, mischief, and metals in cobalt analogs of the superconducting cuprates SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity High Temperature Superconductors VI CY FEB 20-25, 2000 CL HOUSTON, TEXAS ID REFLECTIVITY; CU AB Layered Cobalt oxides provide the possibility for direct comparison with the superconducting cuprates to determine which structural, electronic or chemical factors are required for the occurrence of high temperature superconductivity. Recent results on the study of such materials are reported here. C1 Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08540 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NIST, Ctr Neurtron Res, Gaithersburg, MD 20899 USA. RP Cava, RJ (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV PY 2000 VL 341 BP 351 EP 354 DI 10.1016/S0921-4534(00)00509-8 PN 1 PG 4 WC Physics, Applied SC Physics GA 382YT UT WOS:000165855500126 ER PT J AU Potrepka, DM Budnick, JI Moodenbaugh, AR Fischer, DA Hines, WA AF Potrepka, DM Budnick, JI Moodenbaugh, AR Fischer, DA Hines, WA TI Combined Cu-63,Cu-65 NQR and NMR study of Y1-xCaxBa2Cu3Oy SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity High Temperature Superconductors VI CY FEB 20-25, 2000 CL HOUSTON, TEXAS ID TEMPERATURE AB Zero-field Cu-63,Cu-65 nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) spectra were obtained at 1.3 K for powdered samples of Y1-xCaxBa2Cu3OY with 0 less than or equal to x less than or equal to 0.20. The results for the deoxygenated samples (y = 6.05) demonstrate the existence of an internal magnetic field at the Cu(2) planar sites for Ca content x less than or equal to 0.20 and provide insight into the coexistence of superconductivity and antiferromagnetic correlations as a function of hole doping in the CuO2 planes due to Ca substitution. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. ARL, Sensors & Elect Devices Directorate, Adelphi, MD 20783 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Potrepka, DM (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. OI Potrepka, Daniel/0000-0002-0528-1038; Moodenbaugh, Arnold/0000-0002-3415-6762 NR 5 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV PY 2000 VL 341 BP 611 EP 612 DI 10.1016/S0921-4534(00)00613-4 PN 1 PG 2 WC Physics, Applied SC Physics GA 382YT UT WOS:000165855500231 ER PT J AU Jardim, RF Early, EA Maple, MB AF Jardim, RF Early, EA Maple, MB TI Superconductivity in polycrystalline Sm-1.85(Ce1-xThx)(0.15)CuO4-y compounds SO PHYSICA C LA English DT Article; Proceedings Paper CT International Conference on Materials and Mechanisms of Superconductivity High Temperature Superconductors VI CY FEB 20-25, 2000 CL HOUSTON, TEXAS ID ELECTRON AB We report a study on structural and superconducting properties of Sm-1.85(Ce1-xThx)(0.15)CuO4-y; 0 less than or equal to x less than or equal to 1; samples sintered at temperatures 1100 less than or equal to T-S less than or equal to 1200 degreesC. Electrical resistivity data reveal that the onset of the superconducting critical temperature T-ci decreases systematically with increasing Th content in this series. We found that T-ci in the Sm1.85Th0.15CuO4-y compound assumes values as high as 13 K which is higher than the one first reported of similar to 9 K. Measurements performed in samples subjected to different sintering temperatures T-s show that T-ci increases with increasing sintering temperature and attains its maximum value in samples sintered at 1200 degreesC. This feature is more pronounced in samples with high Th content and sintered at temperatures T-s less than or equal to 1100 degreesC suggesting a low Th diffusion into Sm2CuO4-y matrix. C1 Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. NIST, Gaithersburg, MD 20899 USA. Univ Calif San Diego, Inst Pure & Appl Phys Sci, La Jolla, CA 92093 USA. RP Jardim, RF (reprint author), Univ Sao Paulo, Inst Fis, CP 66318, BR-05315970 Sao Paulo, Brazil. RI Jardim, Renato/J-8068-2014 OI Jardim, Renato/0000-0002-2000-0257 NR 5 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV PY 2000 VL 341 BP 675 EP 676 DI 10.1016/S0921-4534(00)00645-6 PN 1 PG 2 WC Physics, Applied SC Physics GA 382YT UT WOS:000165855500263 ER PT J AU Boisseau, C Audouard, E Vigue, J Julienne, PS AF Boisseau, C Audouard, E Vigue, J Julienne, PS TI Reflection approximation in photoassociation spectroscopy SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; LASER COOLED ATOMS; SCATTERING LENGTHS; ELASTIC-SCATTERING; SODIUM ATOMS; COLLISIONS; COLD; STATE; LI-7; GAS AB We construct an analytical wave function in the phase-amplitude formalism to describe collisions between two neutral atoms. This wave function is valid from intermediate to asymptotic internuclear distance over a large energy range near zero energy, and is especially suitable for cold and ultracold collisions. We have used this analytic wave function with the reflection approximation formula for calculating Franck-Condon factors for photoassociative spectroscopy. Numerical tests show very satisfactory agreement between the resulting analytic formula and the fully quantum numerical results in most cases investigated. Finally, we show in a model case that our analytical wave function enables us to relate the scattering length directly to a preasymptotic node in the ground-state wave function, which in principle can be measured by photoassociative spectroscopy. C1 Univ Toulouse 3, Lab Collis Agregats React, CNRS, UMR 5589, F-31062 Toulouse, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Boisseau, C (reprint author), Univ Toulouse 3, Lab Collis Agregats React, CNRS, UMR 5589, 118 Route Narbonne, F-31062 Toulouse, France. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 46 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 BP art. no. EP 052705 DI 10.1103/PhysRevA.62.052705 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800062 ER PT J AU Mohr, PJ Sapirstein, J AF Mohr, PJ Sapirstein, J TI Evaluation of two-photon exchange graphs for excited states of highly charged heliumlike ions SO PHYSICAL REVIEW A LA English DT Article ID MANY-BODY PROBLEM; GROUND-STATE; LAMB-SHIFT; ENERGY; 2-PHOTON-EXCHANGE; TRANSITION AB Energy shifts arising from two-photon-exchange graphs are calculated for n = 2 triplet states of heliumlike ions and tabulated for the range of nuclear charges Z = 30-92. The results are compared with second-order many-body perturbation theory (MBPT), and the differences are identified as QED effects associated with retardation and negative energy states not included in MBPT. C1 NIST, Gaithersburg, MD 20899 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. RP Mohr, PJ (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 18 TC 40 Z9 40 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 BP art. no. EP 052501 DI 10.1103/PhysRevA.62.052501 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800039 ER PT J AU Wang, H Nikolov, AN Ensher, JR Gould, PL Eyler, EE Stwalley, WC Burke, JP Bohn, JL Greene, CH Tiesinga, E Williams, CJ Julienne, PS AF Wang, H Nikolov, AN Ensher, JR Gould, PL Eyler, EE Stwalley, WC Burke, JP Bohn, JL Greene, CH Tiesinga, E Williams, CJ Julienne, PS TI Ground-state scattering lengths for potassium isotopes determined by double-resonance photoassociative spectroscopy of ultracold K-39 SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; ELASTIC-SCATTERING; ATOMS; COLLISIONS; FIELD; DISPERSION; ASYMPTOTE; CONSTANTS; LITHIUM; VAPOR AB We use double-resonance photoassociative spectroscopy of ultracold K-39 atoms to precisely determine the triplet a (3)Sigma (t)(u) scattering length for the various isotopes of potassium. Photoassociation of free K-39 atoms to the pure long-range 0(g)(-) (v' = 0, J' = 2) level is followed by stimulated emission to high-lying levels of the a (3)Sigma (t)(u) potential. The binding energies of levels within 5 GHz below the lowest ground-state 4s(1/2)(f(a) = 1) +4s(1/2)(f(b) = 1) hyperfine asymptote are measured by both trap loss and ionization detection. The locations of these near-threshold hyperfine-coupled molecular levels allow us to constrain the triplet potential and thereby determine the triplet scattering length. The result for K-39, a(t) = -33 +/- 5a(0) (1a(0) = 0.0529177 nm), is a factor of similar to5 improvement over previous determinations and establishes that a large K-39 Bose-Einstein condensate will not be stable. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. 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 20899 USA. Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. RP Wang, H (reprint author), Aerospace Corp, El Segundo, CA 90245 USA. RI Williams, Carl/B-5877-2009; Greene, Chris/C-3821-2011; Julienne, Paul/E-9378-2012 OI Greene, Chris/0000-0002-2096-6385; Julienne, Paul/0000-0002-5494-1442 NR 26 TC 47 Z9 47 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 BP art. no. EP 052704 DI 10.1103/PhysRevA.62.052704 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800061 ER PT J AU Erdmann, R Branning, D Grice, W Walmsley, IA AF Erdmann, R Branning, D Grice, W Walmsley, IA TI Restoring dispersion cancellation for entangled photons produced by ultrashort pulses SO PHYSICAL REVIEW A LA English DT Article ID PARAMETRIC DOWN-CONVERSION; QUANTUM TELEPORTATION; INTERFERENCE; PUMP AB It is a well-known and remarkable fact that in certain coincidence photon-counting experiments with cw-pumped parametric down-converters, the effects of group-velocity dispersion arising from media interposed between source and detectors are completely canceled, even if the media physically affect only one of the photons of the pair. Recently Perina et al. [Phys. Rev. A 59, 2359 (1999)] showed that this phenomenon does not occur when certain classical timing information is available about the arrival of individual photons at the detectors, as is the case when the photon pairs are produced via spontaneous parametric down-conversion using an ultrashort pump pulse. In this paper we show that the nonlocal cancellation of dispersion far such a source of entangled photons can be restored in principle by proper engineering of the source properties. In particular, we describe techniques for recovering interference in coincidence-counting experiments by suppressing distinguishing information without the post selection of photons. Moreover, a precise classical timing signal coincident with the photon pair is still available. C1 USAF, Res Lab, SNDP, Griffiss AFB, NY 13441 USA. NIST, Gaithersburg, MD 20899 USA. So Illinois Univ, Dept Phys, Edwardsville, IL 62026 USA. Univ Rochester, Inst Opt, Rochester, NY 14627 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. RP USAF, Res Lab, SNDP, Griffiss AFB, NY 13441 USA. RI Grice, Warren/L-8466-2013 NR 20 TC 35 Z9 35 U1 1 U2 6 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 NOV PY 2000 VL 62 IS 5 AR 053810 DI 10.1103/PhysRevA.62.053810 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800114 ER PT J AU Feder, DL Pindzola, MS Collins, LA Schneider, BI Clark, CW AF Feder, DL Pindzola, MS Collins, LA Schneider, BI Clark, CW TI Dark-soliton states of Bose-Einstein condensates in anisotropic traps SO PHYSICAL REVIEW A LA English DT Article ID VORTEX STABILITY; OPTICAL SOLITONS; MATTER WAVES; GAS; VORTICES; FIBERS; PULSES; APPROXIMATION; EXCITATION; CREATION AB Bark soliton states of Bose-Einstein condensates in harmonic traps are studied both analytically and computationally by the direct solution of the Gross-Pitaevskii equation in three dimensions. The ground and self-consistent excited states are found numerically by relaxation in imaginary time. The energy of a stationary soliton in a harmonic trap is shown to be independent of density and geometry for large numbers of atoms. Large-amplitude field modulation at a frequency resonant with the energy of a dark soliton is found to give rise to a state with multiple vortices. The Bogoliubov excitation spectrum of the soliton state contains complex frequencies, which disappear for sufficiently small numbers of atoms or large transverse confinement. The relationship between these complex modes and the snake instability is investigated numerically by propagation in real time. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Natl Sci Fdn, Div Phys, Arlington, VA 22230 USA. RP Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 49 TC 159 Z9 160 U1 3 U2 9 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 NOV PY 2000 VL 62 IS 5 AR 053606 DI 10.1103/PhysRevA.62.053606 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800104 ER PT J AU Kim, YK Santos, JP Parente, F AF Kim, YK Santos, JP Parente, F TI Extension of the binary-encounter-dipole model to relativistic incident electrons SO PHYSICAL REVIEW A LA English DT Article ID K-SHELL IONIZATION; CROSS-SECTIONS; IMPACT IONIZATION; ENERGY-DEPENDENCE; CHARGED PARTICLES; ATOMS; BOMBARDMENT; MOLECULES; ARGON; BEAM AB Formulas for the total ionization cross section by electron impact based on the binary-encounter-dipole (BED) model and its simpler version, the binary-encounter-Bethe (BEB) model are extended to relativistic incident electron energies. Total ionization cross sections for the hydrogen and helium atoms from the new relativistic formulas are compared to experimental data. Relativistic effects double the total ionization cross section of H and He at incident electron energy approximate to 300 keV and dominate the cross section thereafter. A simple modification of the original BED-BEB formulas is: proposed for applications to ion targets and inner-shell electrons of neutral atoms and molecules. The relativistic and nonrelativistic BEB cross sections are compared to the K-shell ionization cross sections by electron impact for the carbon, argon, nickel, niobium, and silver atoms. For carbon and argon, the relativistic effects are small, and both forms of the BEB cross sections agree well with available experimental data. For the nickel and heavier atoms, the relativistic increase of cross sections becomes noticeable from about 100 keV and higher in the incident electron energy. The empirical formula by Casnati ef al. [J.. Phys. B 15, 155 (1982)] after correcting for relativistic effects as shown by Quarles [Phys. Rev. A 13, 1278 (1976)] agrees well with the BEB cross sections for light atoms. However, the peak values of the Casnati cross sections become higher than the relativistic BEB peak cross sections as the atomic number increases. The BEB model is also applied to the total ionization cross section of the xenon atom, and the theory agrees well with experiments at low incident electron energies, but disagrees with experiment at relativistic incident energies. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Fis, P-2825114 Monte De Caparica, Caparica, Portugal. Univ Lisbon, Ctr Fis Atom, P-1649003 Lisbon, Portugal. Univ Lisbon, Dept Fis, P-1649003 Lisbon, Portugal. RP Kim, YK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Santos, Jose Paulo/F-4186-2010 OI Santos, Jose Paulo/0000-0002-5890-0971 NR 57 TC 82 Z9 82 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 AR 052710 DI 10.1103/PhysRevA.62.052710 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800067 ER PT J AU Turchette, QA Myatt, CJ King, BE Sackett, CA Kielpinski, D Itano, WM Monroe, C Wineland, DJ AF Turchette, QA Myatt, CJ King, BE Sackett, CA Kielpinski, D Itano, WM Monroe, C Wineland, DJ TI Decoherence and decay of motional quantum states of a trapped atom coupled to engineered reservoirs SO PHYSICAL REVIEW A LA English DT Article ID ZERO-POINT ENERGY; PAUL TRAP; IONS AB We present results from an experimental study of the decoherence and decay of quantum states of a trapped atomic ion's harmonic motion interacting with several types of engineer ed reservoirs. We experimentally simulate three types of reservoirs: a high-temperature amplitude reservoir, a zero-temperature amplitude reservoir, and a high-temperature phase reservoir. Interaction with these environments causes the ion's motional state to decay or heat, and in the case of superposition states, to lose coherence. We report measurements of the decoherence of superpositions of coherent states and two-Fock-state superpositions into these reservoirs, as well as the decay and heating of Fock states. We confirm the theoretically well-known scaling laws that predict that the decoherence rate of superposition states scales with the square of the "size"' of the state. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Turchette, QA (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RI Monroe, Christopher/G-8105-2011 NR 32 TC 156 Z9 159 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 AR 053807 DI 10.1103/PhysRevA.62.053807 PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800111 ER PT J AU Wang, HY Chang, CH Hwang, SR Li, WH Lee, KC Lynn, JW Luo, HM Ku, HC AF Wang, HY Chang, CH Hwang, SR Li, WH Lee, KC Lynn, JW Luo, HM Ku, HC TI Variation in the structural and magnetic properties induced by La doping in Pr(Br1-xLax)(2)Cu3O7+y SO PHYSICAL REVIEW B LA English DT Article ID SOLID-SOLUTION; PRBA2CU3O7; PR; SUPERCONDUCTIVITY; OXYGEN; SUSCEPTIBILITY; HYBRIDIZATION; SUPPRESSION; NEUTRON; SYSTEM AB Neutron diffraction and ac magnetic susceptibility measurements were performed to study the effects of La doping on the structural and magnetic properties of polycrystalline Pr(Ba1-xLax)(2)Cu3O7+y. Structural studies using high-resolution neutron diffraction and Rietveld analysis indicate that La doping triggers the occupation of O on the antichain sites which reduces the degree of orthorhombicity in the system. Tetragonal symmetry was observed in the 29% La-doped compound. Magnetic orderings of the Pr ions as well as the Cu ions were evident in the susceptibility. The Pr spin ordering was confirmed by the neutron magnetic diffraction data. Significant reductions in the ordering temperature of Pr were found upon increased La doping, while the spin configuration remained. No obvious changes were observed in the ordering temperature of Cu. C1 Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Natl Tsing Hua Univ, Dept Phys, Hsinchu 300, Taiwan. RP Wang, HY (reprint author), Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NR 35 TC 3 Z9 3 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 NOV 1 PY 2000 VL 62 IS 17 BP 11549 EP 11555 DI 10.1103/PhysRevB.62.11549 PG 7 WC Physics, Condensed Matter SC Physics GA 371WH UT WOS:000165201900053 ER PT J AU Lising, LJ Hwang, SR Adams, JM Bowles, TJ Browne, MC Chupp, TE Coulter, KP Dewey, MS Freedman, SJ Fujikawa, BK Garcia, A Greene, GL Jones, GL Mumm, HP Nico, JS Richardson, JM Robertson, RGH Steiger, TD Teasdale, WA Thompson, AK Wasserman, EG Wietfeldt, FE Welsh, RC Wilkerson, JF AF Lising, LJ Hwang, SR Adams, JM Bowles, TJ Browne, MC Chupp, TE Coulter, KP Dewey, MS Freedman, SJ Fujikawa, BK Garcia, A Greene, GL Jones, GL Mumm, HP Nico, JS Richardson, JM Robertson, RGH Steiger, TD Teasdale, WA Thompson, AK Wasserman, EG Wietfeldt, FE Welsh, RC Wilkerson, JF CA emiT Collaboration TI New limit on the D coefficient in polarized neutron decay SO PHYSICAL REVIEW C LA English DT Article ID TIME-REVERSAL INVARIANCE; ELECTRIC-DIPOLE MOMENT; CP-VIOLATION; BETA-DECAY; SUPERMIRRORS; KAON AB We describe an experiment that has set new limits on the time reversal invariance violating D coefficient in neutron beta decay. The emiT experiment measured the angular correlation [J] . (p(e) x p(p)) using an octagonal symmetry that optimizes electron-proton coincidence rates. The result is D=[-0.6+/-1.2(stat)+/-0.5(syst)] x 10(-3). This improves constraints on the phase of g(A)/g(V) and limits contributions to T violation due to leptoquarks. This paper presents details of the experiment, data analysis, and the investigation of systematic effects. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Michigan, Ann Arbor, MI 48101 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Washington, Seattle, WA 98195 USA. RP Lising, LJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 28 TC 53 Z9 53 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 2000 VL 62 IS 5 AR 055501 DI 10.1103/PhysRevC.62.055501 PG 11 WC Physics, Nuclear SC Physics GA 374XF UT WOS:000165369400062 ER PT J AU Parra, E Alexeev, I Fan, J Kim, KY McNaught, SJ Milchberg, HM AF Parra, E Alexeev, I Fan, J Kim, KY McNaught, SJ Milchberg, HM TI X-ray and extreme ultraviolet emission induced by variable pulse-width irradiation of Ar and Kr clusters and droplets SO PHYSICAL REVIEW E LA English DT Article ID INTENSE LASER-PULSES; ATOMIC CLUSTERS; HOT NANOPLASMAS; ARGON CLUSTERS; GAS; ABSORPTION; EXPLOSION; PRESSURE; YIELDS AB Measurements are presented of x-ray (>1.5 keV) and extreme ultraviolet (EUV, lambda = 2-44 nm) emission from argon and krypton supersonic gas jets at room (T = 300 K) and cryogenic (T = 173 K) temperatures irradiated with constant energy (50 mJ), variable width laser pulses ranging from 100 fs to 10 ns. Two regimes of jet operation are explored: cluster formation (radius < 100 nm) and droplet formation (radius > 1 mum). The results for both clusters and droplets can be understood in terms of two time scales: a short time scale for optimal resonant absorption at the critical density layer in the expanding plasma, and a longer time scale for the plasma to drop below critical density. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Parra, E (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 26 TC 94 Z9 96 U1 0 U2 15 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 NOV PY 2000 VL 62 IS 5 BP R5931 EP R5934 DI 10.1103/PhysRevE.62.R5931 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 374JH UT WOS:000165341700015 ER PT J AU Battaglia, F Rehm, RG Baum, HR AF Battaglia, F Rehm, RG Baum, HR TI The fluid mechanics of fire whirls: An inviscid model SO PHYSICS OF FLUIDS LA English DT Article AB Whirling fire plumes are known to increase the danger of naturally occurring or post-disaster fires. In order for a fire whirl to exist, there must be an organized source of angular momentum to produce the large swirl velocities as air is entrained into the fire plume. These vorticity-driven fires occur over a large range of length and velocity scales, and significantly alter the entrainment and combustion dynamics. A new model is derived for a buoyant plume that incorporates angular rotation and neglects dissipation; the result is a form of the steady state Euler equations. Included is a general solution for large density and temperature variations. Results are presented that identify the mechanisms and their effects toward creating a fire whirl. (C) 2000 American Institute of Physics. [S1070- 6631(00)50211-6]. C1 Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Battaglia, F (reprint author), Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. RI Battaglia, Francine/E-9189-2014 OI Battaglia, Francine/0000-0002-0380-3402 NR 13 TC 21 Z9 23 U1 3 U2 15 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2000 VL 12 IS 11 BP 2859 EP 2867 DI 10.1063/1.1308510 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 360FZ UT WOS:000089656900017 ER PT J AU Karim, A Liu, DW Douglas, JF Nakatani, AI Amis, EJ AF Karim, A Liu, DW Douglas, JF Nakatani, AI Amis, EJ TI Modification of the phase stability of polymer blends by fillers SO POLYMER LA English DT Article DE phase stability; polymer blends; fillers ID METHACRYLATE) MIXTURES; SEMIDILUTE SOLUTION; SHEAR-FLOW; COMPATIBILITY; SEPARATION AB We investigate the influence of filler particles on the phase stability of a model blend of polystyrene (PS) and polybutadiene (PB). The upper critical solution temperature cloud point curve of a PS:PB blend is "destabilized" (upward shift of cloud point temperature) by the addition of untreated fumed silica filler particles. Preliminary cloud point measurements on surface-functionalized fumed silica particles were also performed. A small downward shift of the cloud point temperature was observed by functionalizing the filler particles with grafted polystyrene chains, while grafting with a silane coupling agent resulted in a large apparent "stabilization" effect or a decrease of the cloud point temperature. (Further measurements on surface-functionalized filler particles over a range of polymer compositions are required to determine the filler concentration dependence of the shift of the blend critical temperature.) Surface treatments were selected to demonstrate that modifying the filler particle surface chemistry can alter the blend phase boundary. These phase boundary shifts have significance in commercial blends containing dispersions of filler particles. (C) 2000 Elsevier Science Ltd. All rights reserved. RP Karim, A (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 21 TC 41 Z9 43 U1 1 U2 15 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD NOV PY 2000 VL 41 IS 23 BP 8455 EP 8458 DI 10.1016/S0032-3861(00)00245-7 PG 4 WC Polymer Science SC Polymer Science GA 337RR UT WOS:000088375900034 ER PT J AU Hastie, JW Bonnell, DW Schenck, PK AF Hastie, JW Bonnell, DW Schenck, PK TI Development and application of very high temperature mass spectrometry. Vapor pressure determinations over liquid refractories SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 10th International Conference on High Temperature Materials Chemistry (HTMC-X) CY APR 10-14, 2000 CL JULICH, GERMANY ID THIN-FILM DEPOSITION; PLUMES AB Existing thermodynamic and vaporization data for liquid refractories are based either on estimates or on data extrapolated from studies on the solids obtained at much lower temperatures. Previously, we have shown that pulsed laser heating, coupled with time-dependent mass spectrometry of the free-expansion vapor plume, can be used for semi-quantitattive measurements of vaporization thermochemistry. The present work extends this approach with the development of (a) more direct, and more accurate, methods for determining the system temperature and pressure, (b) improved experimental and theoretical determinations of key parameters such as ionization cross sections; and (c) improved characterization of the gas dynamic expansion and thermal equilibration processes. Example material systems considered include C, SiC, Al2O3, ZrO2-7%Y2O3, and Y2O3 at temperatures and total pressures typically in the range of 3000 to 5000 K and 0.01 to 10 bar, respectively (1 bar = 10(5) Nm(-2)). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hastie, JW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 38 TC 15 Z9 15 U1 0 U2 0 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD NOV PY 2000 VL 72 IS 11 BP 2111 EP 2126 DI 10.1351/pac200072112111 PG 16 WC Chemistry, Multidisciplinary SC Chemistry GA 407DV UT WOS:000167257500004 ER PT J AU Nakatani, AI Ivkov, R Papanek, P Yang, H Gerspacher, M AF Nakatani, AI Ivkov, R Papanek, P Yang, H Gerspacher, M TI Inelastic neutron scattering from filled elastomers SO RUBBER CHEMISTRY AND TECHNOLOGY LA English DT Article ID CARBON BLACK INTERACTIONS; METHYL-GROUP DYNAMICS; GLASS-TRANSITION; NATURAL-RUBBER; POLYBUTADIENE; POLYISOBUTYLENE; POLYISOPRENE; POLYETHYLENE; RESONANCE; MOTION AB Inelastic neutron scattering experiments are powerful techniques for evaluating local molecular dynamics. These methods are especially sensitive to hydrogen atoms containing motions. An overview of these experimental techniques is presented. Neutron filter analyzer and time-of-flight spectroscopy methods are used to characterize the local dynamics of polymers in the presence and absence of fillers. Of particular interest is the comparison between bound rubber attached to the filler surface and the pure, unbound rubber. A commercial synthetic polyisoprene containing approximately 100% cis-1,4 isomers was compounded with three different carbon blacks: N299, G299 (graphitized N299), and N762. Soxhlet extraction on each of the samples was performed so that corresponding samples containing purely bound rubber with filler were obtained. The filter analyzer and time-of flight spectra show distinct differences between the bound and pure rubber as well as differences based on carbon black type. Correlation of the spectral differences to the type of carbon black and initial concentration of carbon black are discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. Sid Richardson Carbon Co, Ft Worth, TX 76106 USA. RP Nakatani, AI (reprint author), Rohm & Haas Co, POB 904,727 Norristown Rd, Spring House, PA 19477 USA. RI Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 33 TC 7 Z9 7 U1 1 U2 3 PU AMER CHEMICAL SOC INC PI AKRON PA RUBBER DIV UNIV AKRON PO BOX 499, AKRON, OH 44309-0499 USA SN 0035-9475 J9 RUBBER CHEM TECHNOL JI Rubber Chem. Technol. PD NOV-DEC PY 2000 VL 73 IS 5 BP 847 EP 863 DI 10.5254/1.3547624 PG 17 WC Polymer Science SC Polymer Science GA 407PX UT WOS:000167280900005 ER PT J AU Newbury, DE AF Newbury, DE TI Measures for spectral quality in low-voltage x-ray microanalysis SO SCANNING LA English DT Article DE charging; conducting grid method; Duane-Hunt limit; electron beam x-ray microanalysis; low-voltage scanning electron microscopy; overvoltage AB Characteristic x-ray production with energetic electrons depends strongly on the overvoltage, the ratio of the incident beam energy to the critical excitation energy for the atomic species of interest. Low-voltage x-ray microanalysis (beam energy less than or equal to5 keV) is especially susceptible to artifacts due to sample charging because the overvoltage is low and even slight charging can strongly affect peak intensities. The Duane-Hunt bremsstrahlung limit is a good diagnostic to detect sample charging. Dynamic charging effects, however, can influence spectra despite an apparently satisfactory Duane-Hunt limit. Dynamic charging effects must be examined by time series experiments, or through use of dynamic energy windows continuously measuring count rates placed across the spectrum. When charging is a problem, conductive surface coatings can eliminate the effects.. When pristine surfaces must be examined without coating, the use of a conductive grid can control charging so that, useful x-ray spectra can be obtained. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Newbury, DE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 6 Z9 6 U1 0 U2 3 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430-0832 USA SN 0161-0457 J9 SCANNING JI Scanning PD NOV-DEC PY 2000 VL 22 IS 6 BP 345 EP 351 PG 7 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 381TG UT WOS:000165779100002 PM 11145259 ER PT J AU Reid, GC AF Reid, GC TI Solar variability and the Earth's climate: Introduction and overview SO SPACE SCIENCE REVIEWS LA English DT Editorial Material CT Workshop of the ISSI on Solar Variability and Climate CY JUN 28-JUL 02, 1999 CL INT SPACE SCI INST, BERN, SWITZERLAND HO INT SPACE SCI INST DE solar variability; Earth's climate ID IRRADIANCE VARIATIONS; SURFACE-TEMPERATURE; MAUNDER MINIMUM; PROTON EVENTS; IMPACT; CYCLE; LINK AB Numerous attempts have been made over the years to link various aspects of solar variability to changes in the Earth's climate. There has been growing interest in this possible connection in recent years, spurred largely by the need to understand the natural causes of climate change, against which the expected global warming due to man's activities will have to be detected. The time scale of concern here is that of decades to centuries, and excludes the longer millennial scale in which orbital variations play a dominant role. The field has long been plagued by the lack of an acceptable physical mechanism by which solar variability can affect climate, but the discovery of variability in the Sun's total irradiance (the solar "constant'' of meteorology) by spacecraft instruments has pointed to a direct mechanism. Other less direct mechanisms that have been suggested involve variations in the Sun's ultraviolet flux and in the plasma outflow of the solar wind. The purpose of this paper is to summarize the current state of the field, emphasizing the proposed mechanisms as an introduction to the more detailed papers that follow. The particular case of sea-surface temperature data will be used as an illustration. C1 Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Reid, GC (reprint author), Univ Colorado, CIRES, Boulder, CO 80303 USA. NR 37 TC 61 Z9 65 U1 2 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD NOV PY 2000 VL 94 IS 1-2 BP 1 EP 11 DI 10.1023/A:1026797127105 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 379FM UT WOS:000165631400001 ER PT J AU Norris, JR AF Norris, JR TI What can cloud observations tell us about climate variability? SO SPACE SCIENCE REVIEWS LA English DT Review AB Clouds have a large impact on the Earth's radiation budget and hence have the potential to exert strong feedbacks on climate variability and climate change. These feedbacks are not well-understood, so it is essential to investigate observed relationships between cloud properties and other parameters of the climate system. Suitable cloud datasets based on surface observations and satellite observations are described and various advantages and disadvantages of each are discussed. In particular it is noted that significant inhomogeneities likely exist in the datasets which have important implications for studies of climate variability. Recommendations are made for the use of cloud data in future investigations. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RI Norris, Joel/A-9785-2008 OI Norris, Joel/0000-0003-4384-0977 NR 14 TC 39 Z9 41 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD NOV PY 2000 VL 94 IS 1-2 BP 375 EP 380 DI 10.1023/A:1026704314326 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 379FM UT WOS:000165631400034 ER PT J AU Kreider, KG Gillen, G AF Kreider, KG Gillen, G TI High temperature materials for thin-film thermocouples on silicon wafers SO THIN SOLID FILMS LA English DT Article DE rapid thermal processing; thin film thermocouples; calibration; rhodium; palladium; iridium; platinum; wafer AB We have developed an instrumented calibration wafer for radiometric temperature measurements in rapid thermal processing (RTP) tools for semiconductor processing. The instrumented wafers have sputter deposited thin-film thermocouples to minimize the thermal disturbance of the wafer by the sensors. The National Institute of Standards and Technology (NIST) calibration wafer also employs platinum-palladium wire thermocouples to achieve a combined standard uncertainty of 0.4 degreesC in the temperature measurement of the thin-film thermocouple junction at 900 degreesC. The high temperatures of the wafer has required the development of new thin-film material systems. We have reported the results of our testing and characterization of sputtered platinum, palladium, rhodium, and iridium thin films using titanium bond coats on thermally oxidized silicon wafers. Depth profiling with secondary ion mass spectrometry was used to determine the diffusion profiles from the metal film to the silicon after heat treatments as high as 1000 degreesC. Electron microscopy and optical microscopy were used to follow the reactions and the deterioration of the thermoelectric films. In addition, performance tests up to 1000 degreesC in the NIST RTP test bed were used to determine the stability of the material systems. Failure mechanisms and limitations of the thin-him thermocouple materials have been discussed with data on hysteresis and drift in thermometry performance. The results of our evaluations indicated that Rh/Ir thin-film thermocouples have the best properties for wafer temperatures above 900 degreesC. (C) 2000 Elsevier Science S.A. All rights reserved. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Kreider, KG (reprint author), NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 11 TC 40 Z9 42 U1 2 U2 35 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV 1 PY 2000 VL 376 IS 1-2 BP 32 EP 37 DI 10.1016/S0040-6090(00)01346-8 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 371YT UT WOS:000165207400006 ER PT J AU Doucette, GJ Powell, CL Do, EU Byon, CY Cleves, F McClain, SG AF Doucette, GJ Powell, CL Do, EU Byon, CY Cleves, F McClain, SG TI Evaluation of 11-[H-3]-tetrodotoxin use in a heterologous receptor binding assay for PSP toxins SO TOXICON LA English DT Article DE paralytic shellfish poisoning; receptor binding assay; tetrodotoxin; saxitoxin; toxic dinoflagellates; harmful algal blooms ID TETRODOTOXIN AB This report describes the preparative scale production of 11-[H-3]-tetrodotoxin (TTX) and its evaluation as a substitute for [H-3]-saxitoxin (STX) as the radioligand in a receptor binding assay for paralytic shellfish poisoning (PSP) toxins. Restrictions on the world-wide distribution of [H-3]-STX imposed by the international Chemical Weapons Convention served as the primary impetus for this study. We have incorporated on a preparative scale, a nonexchangeable tritium label into the TTX molecule at a specific activity of 12.90 Ci/mmol and recovered material of high radiochemical purity (98%). The resulting 11-[H-3]TTX was found to exhibit site-specific binding characteristics in the receptor assay (dissociation constant (K-d) = 4.77 +/- 1.54 nM; maximum binding (B-max) = 1.62 +/- 0.24 pmol/mg of synaptosomal protein). The inhibition constant (K-i) for the assay was 1.46 +/- 0.28 nM STX equiv. (n = 6), with an estimated detection limit of ca. 2-4 ng STX equiv./ml in a sample extract. Moreover, quantitative comparisons indicated that 11-[H-3]-TTX could be used interchangeably with [H-3]-STX in the receptor assay for determination of PSP toxicity in shellfish and algal extracts without compromising assay performance. We conclude that the 11-[H-3]-TTX produced and evaluated herein exhibits physical, chemical and biological characteristics suitable not only for use in the PSP receptor binding assay, but likely for other applications employing [H-3]-STX as the radioligand. Published by Elsevier Science Ltd. C1 Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, NOAA, Marine Biotoxins Program, Charleston, SC 29412 USA. NEN Life Sci Prod, Boston, MA 02118 USA. RP Doucette, GJ (reprint author), Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, NOAA, Marine Biotoxins Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. RI Doucette, Gregory/M-3283-2013 NR 11 TC 16 Z9 17 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0041-0101 J9 TOXICON JI Toxicon PD NOV PY 2000 VL 38 IS 11 BP 1465 EP 1474 DI 10.1016/S0041-0101(99)00240-8 PG 10 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 323XJ UT WOS:000087590000001 PM 10775748 ER PT J AU Scharf, FS AF Scharf, FS TI Patterns in abundance, growth, and mortality of juvenile red drum across estuaries on the Texas Coast with implications for recruitment and stock enhancement SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID MARINE DEMERSAL FISH; SCIAENOPS-OCELLATUS; CLASS STRENGTH; CONTINENTAL-SHELF; FOOD-HABITS; LARVAL; VARIABILITY; PREDATION; LOUISIANA; WATERS AB The interannual variation in patterns of abundance, growth, and mortality of juvenile red drum Sciaenops ocellatus was examined with long-term monitoring data from nine estuaries along the Texas Gulf Coast during a 20-year period. Estimates of abundance and mortality exhibited order-of-magnitude differences. Growth rates varied two- to threefold across years within each estuary and across estuaries within a single year. For age-0 juveniles, abundance was typically highest in late fall, length increased exponentially, and mortality was generally low. Variation in growth and mortality was not related among estuaries, suggesting that the factors affecting the feeding and survival of young red drum are specific to individual estuarine systems. Estimates of age-0 red drum abundance were characterized by the intermittent occurrence of strong year-classes and were positively correlated across estuaries, indicating that factors determining abundance and distribution vary on a large spatial scale. Correlative evidence suggests that compensatory mech anisms affect the survival of age-0 red drum. Variation in abundance during early juvenile stages was not related to abundance variability in later juvenile stages and was significantly reduced by the end of the first year of life, indicating that processes occurring during the juvenile stage may be important in regulating the year-class strength of red drum. Clear effects of increased stocking rates of hatchery-reared fingerlings during the last decade on the abundance of age-0 and age-1 red drum were not detected. C1 Texas Pk & Wildlife Coastal Fisheries Div, Seabrook Marine Lab, Seabrook, TX 77586 USA. RP Scharf, FS (reprint author), NOAA, NMFS, NEFSC, James J Howard Marine Lab, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 47 TC 41 Z9 42 U1 3 U2 17 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 NOV PY 2000 VL 129 IS 6 BP 1207 EP 1222 DI 10.1577/1548-8659(2000)129<1207:PIAGAM>2.0.CO;2 PG 16 WC Fisheries SC Fisheries GA 405DB UT WOS:000167141400001 ER PT J AU Dongmo, LS Villarrubia, JS Jones, SN Renegar, TB Postek, M Song, JF AF Dongmo, LS Villarrubia, JS Jones, SN Renegar, TB Postek, M Song, JF TI Experimental test of blind tip reconstruction for scanning probe microscopy SO ULTRAMICROSCOPY LA English DT Article DE SPM; dimensional metrology; tip characterization; blind reconstruction ID ATOMIC-FORCE MICROSCOPY; TUNNELING MICROSCOPY; ROUGH SURFACES; GOLD PARTICLES; IMAGES; RESTORATION; GEOMETRY; SHAPE AB Determination of the tip geometry is a prerequisite to converting the scanning probe microscope (SPM) from a simple imaging instrument to a tool that can perform width measurements accurately. Recently we developed blind reconstruction, a method to characterize the SPM tip shape. In principle this method allows estimation of the tip shape from an image of a till characterizer sample that need not be known independently. In this work, we compare blind reconstruction results to those obtained by scanning electron microscopy for two diamond stylus profiler tips, one of which has a gentle shape and the other a more complicated profile. Of the two comparisons, the poorer agreement is still better than 30 nm for parts of the tip within a several micrometer neighborhood of the apex. In both cases the differences are comparable to the combined standard uncertainties of the measurements. We estimate uncertainties from five sources, the most significant of which is the repeatability of the stylus profiling instrument. In a separate measurement we determine the geometry of a silicon nitride SPM tip. The measured radius, 4-fold symmetry, included angle, and tilt are all consistent with expectations for such a tip. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Nanoscale Metrol Grp, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Villarrubia, JS (reprint author), Natl Inst Stand & Technol, Nanoscale Metrol Grp, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 30 TC 70 Z9 78 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD NOV PY 2000 VL 85 IS 3 BP 141 EP 153 DI 10.1016/S0304-3991(00)00051-6 PG 13 WC Microscopy SC Microscopy GA 367DN UT WOS:000090046600003 ER PT J AU Siewert, T McCowan, C Bushey, R Robinson, B Christ, T Hildebrand, K AF Siewert, T McCowan, C Bushey, R Robinson, B Christ, T Hildebrand, K TI Preserving a national landmark SO WELDING JOURNAL LA English DT Article C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. ESAB Welding & Cutting Prod, Florence, Italy. Off Architect Capitol, Washington, DC USA. RP Siewert, T (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD NOV PY 2000 VL 79 IS 11 BP 54 EP 60 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 370UN UT WOS:000165141000012 ER PT J AU Dong, J Drohat, AC Stivers, JT Pankiewicz, KW Carey, PR AF Dong, J Drohat, AC Stivers, JT Pankiewicz, KW Carey, PR TI Raman spectroscopy of uracil DNA glycosylase-DNA complexes: Insights into DNA damage recognition and catalysis SO BIOCHEMISTRY LA English DT Article ID BASE-EXCISION-REPAIR; ESCHERICHIA-COLI; CRYSTAL-STRUCTURES; MECHANISM; PROTEIN AB Using off-resonance Raman spectroscopy, we have examined each complex along the catalytic pathway of the DNA repair enzyme uracil DNA glycosylase (UDG). The binding of undamaged DNA to UDG results in decreased intensity of the DNA Raman bands, which can be attributed to an increased level of base stacking, with little perturbation in the vibrational modes of the DNA backbone. A specific complex between UDG and duplex DNA containing 2'-beta -fluorodeoxyuridine shows similar increases in the level of DNA base stacking, but also a substrate-directed conformational change in UDG that is not observed with undamaged DNA, consistent with an induced-fit mechanism for damage site recognition. The similar increases in the level of DNA base stacking for the nonspecific and specific complexes suggest a common enzyme-induced distortion in the DNA, potentially DNA bending. The difference spectrum of the extrahelical uracil base in the substrate-analogue complexes reveals only a small electron density reorganization in the uracil ring for the ground state complex, but large 34 cm(-1) downshifts in the carbonyl normal modes. Thus, UDG activates the uracil ring in the ground state mainly through H bonds to its C=O groups, without destroying its quasi-aromaticity. This result is at variance with the conclusion from a recent crystal structure, in which the UDG active site significantly distorts the flipped-out pseudouridine analogue such that a change in hybridization at C1 occurs [Parikh, S. S., et al, (2000) Proc. Natl. Acad Sci. USA 97, 5083]. The Raman vibrational signature of the bound uracil product differs significantly from that of free uracil at neutral pH, and indicates that the uracil is anionic. This is consistent with recent NMR results, which established that the enzyme stabilizes the uracil anion leaving group by 3.4 pK(a) units compared to aqueous solution, contributing significantly to catalysis, These observations are generally not apparent from the high-resolution crystal structures of UDG and its complexes with DNA; thus, Raman spectroscopy can provide unique and valuable insights into the nature of enzyme-DNA interactions. C1 Case Western Reserve Univ, Dept Biochem, Cleveland, OH 44106 USA. Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. Pharmasset Inc, Tucker, GA 30084 USA. RP Carey, PR (reprint author), Case Western Reserve Univ, Dept Biochem, 10900 Euclid Ave, Cleveland, OH 44106 USA. FU NIGMS NIH HHS [GM54072, R01GMS56834, R01 GM056834] NR 24 TC 40 Z9 41 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 31 PY 2000 VL 39 IS 43 BP 13241 EP 13250 DI 10.1021/bi001437m PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 368FQ UT WOS:000090107400017 PM 11052677 ER PT J AU Hayashi, M Hashimoto, T Hasegawa, H Takenaka, M Grull, H Esker, AR Weber, M Satija, SK Han, CC Nagao, M AF Hayashi, M Hashimoto, T Hasegawa, H Takenaka, M Grull, H Esker, AR Weber, M Satija, SK Han, CC Nagao, M TI Interface between a polysulfone and polyamide as studied by combined neutron reflectivity and small-angle neutron scattering techniques SO MACROMOLECULES LA English DT Article ID POLYMER-POLYMER INTERFACES; STAGE SPINODAL DECOMPOSITION; SPONGE-LIKE STRUCTURES; DIBLOCK COPOLYMERS; REACTION-KINETICS; LIGHT-SCATTERING; BLENDS; COMPATIBILIZATION; MIXTURES; LIQUIDS AB Interfaces between the two phases formed in immiscible polymer pairs were studied by means of neutron reflectivity (NR) combined with small-angle neutron scattering (SANS). The interfacial widths evaluated by the two methods were compared for two systems: a nonreactive system composed of polyamide (PA) and polysulfone (PSU) and a reactive system composed of PA and PSU with a phthalic anhydride reactive end group (PSU-R) in which PSU-b-PA block copolymers can be formed at the interface. SANS measurements were made on bulk mixtures, and the NR measurements were performed on thin film bilayer stacks of PA and PSU or PSU-R. The intrinsic interfacial widths, WI,(diffuse), obtained from the two methods were compared for the samples that underwent similar annealing protocols and were quenched below the glass transition temperatures Tg's to room temperature. A consistent result for W-I,W-diffuse can be obtained for the two methods only after taking into account the following important factors: (i) the SANS intensity should be corrected for the frozen density heterogeneities within each phase as well as the frozen thermal composition fluctuations; (ii) the contribution of capillary wave fluctuations to a net (or observed) interfacial width, Wi,obs, is more significant for NR than SANS. Without the former correction, the SANS profiles at high scattering vector, q, showed asymptotic behavior of q(-n) (n < 4), giving an erroneous conclusion on WI,obs The WI,obs values obtained for the reactive system were found to be larger than those for the nonreactive system for both methods, reflecting block copolymer formation at the interfaces. The interfacial area density, , for the bulk mixture of the reactive system rapidly decreased with time and reached a constant value within ca. 2 min after annealing above the T-g's, while Sigma for the nonreactive system kept decreasing with time. This elucidates that the growth of the phase-separating domains in the reactive system was pinned by the formation of block copolymers at the interfaces during early annealing times. C1 Kyoto Univ, Grad Sch Engn, Dept Polymer Chem, Kyoto 6068501, Japan. NIST, Div Polymer, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. BASF AG, Polymer Res Lab, D-67056 Ludwigshafen, Germany. Univ Tokyo, Inst Solid State Phys, Neutron Scattering Facil, Tokai, Ibaraki, Japan. RP Hashimoto, T (reprint author), Kyoto Univ, Grad Sch Engn, Dept Polymer Chem, Kyoto 6068501, Japan. NR 48 TC 7 Z9 7 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 31 PY 2000 VL 33 IS 22 BP 8375 EP 8387 DI 10.1021/ma000661g PG 13 WC Polymer Science SC Polymer Science GA 370UL UT WOS:000165140700040 ER PT J AU Ye, J Yoon, TH Hall, JL Madej, AA Bernard, JE Siemsen, KJ Marmet, L AF Ye, J Yoon, TH Hall, JL Madej, AA Bernard, JE Siemsen, KJ Marmet, L TI Accuracy comparison of absolute optical frequency measurement between harmonic-generation synthesis and a frequency-division femtosecond comb SO PHYSICAL REVIEW LETTERS LA English DT Article ID MODE-LOCKED LASER; RYDBERG CONSTANT; THZ; TRANSITIONS; HYDROGEN; SINGLE; CHAIN AB Using an iodine-stabilized He-Ne laser as a transfer oscillator, we compare absolute measurements of the optical frequency from a traditional frequency synthesis chain based on harmonic generation and from the frequency division technique of an ultrawide bandwidth femtosecond frequency comb. The agreement between these two measurements, both linked to the Cs standard, is 220 +/- 770 Hz, yielding a measure ment accuracy of 1.6 x 10(-12). We report 473 612 353 604.8 +/- 1.2 kHz as a preliminary updated value of the absolute frequency of the "f" component for the He-Ne laser international standard at 633 nm. C1 NIST, Quantum Phys Div, Boulder, CO 80309 USA. KRISS, Taejon 305600, South Korea. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Res Council Canada, Inst Natl Measurement Stand, Ottawa, ON K1A 0R6, Canada. Bur Int Poids & Mesures, F-92312 Sevres, France. RP Ye, J (reprint author), NIST, Quantum Phys Div, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011 NR 21 TC 65 Z9 66 U1 5 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 30 PY 2000 VL 85 IS 18 BP 3797 EP 3800 DI 10.1103/PhysRevLett.85.3797 PG 4 WC Physics, Multidisciplinary SC Physics GA 368ZA UT WOS:000090146300014 ER PT J AU Keimer, B Casa, D Ivanov, A Lynn, JW von Zimmermann, M Hill, JP Gibbs, D Taguchi, Y Tokura, Y AF Keimer, B Casa, D Ivanov, A Lynn, JW von Zimmermann, M Hill, JP Gibbs, D Taguchi, Y Tokura, Y TI Spin dynamics and orbital state in LaTiO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID LAMNO3; SCATTERING; CRYSTAL; YVO3 AB A neutron scattering study of the Mott-Hubbard insulator LaTiO3 (T-N = 132 K)reveals a spin wave spectrum that is well described by a nearest-neighbor superexchange constant J = 15.5 meV and a small Dzyaloshinskii-Moriya interaction (D = 1.1 meV). The nearly isotropic spin wave spectrum is surprising in view of the absence of a static Jahn-Teller distortion that could quench the orbital angular momentum, and it may indicate strong orbital fluctuations. A resonant x-ray scattering study has uncovered no evidence of orbital order in LaTiO3. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Tokyo 113, Japan. RP Keimer, B (reprint author), Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. RI Taguchi, Yasujiro/A-3048-2010; Tokura, Yoshinori/C-7352-2009; Casa, Diego/F-9060-2016 NR 22 TC 154 Z9 155 U1 2 U2 32 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 30 PY 2000 VL 85 IS 18 BP 3946 EP 3949 DI 10.1103/PhysRevLett.85.3946 PG 4 WC Physics, Multidisciplinary SC Physics GA 368ZA UT WOS:000090146300051 ER PT J AU Adams, CP Lynn, JW Mukovskii, YM Arsenov, AA Shulyatev, DA AF Adams, CP Lynn, JW Mukovskii, YM Arsenov, AA Shulyatev, DA TI Charge ordering and polaron formation in the magnetoresistive oxide La0.7Ca0.3MnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLOSSAL-MAGNETORESISTANCE; SPIN DYNAMICS; SINGLE-CRYSTALS; LA1-XCAXMNO3; LA1-XSRXMNO3; MANGANITES; STRIPES; PHASE; LA0.85SR0.15MNO3; TRANSITION AB Neutron scattering has been used to study the nature of the ferromagnetic transition in a single crystal of the perovskite La0.7Ca0.3MnO3. Diffuse scattering from lattice polarons develops as the Curie temperature is approached from below, along with short range polaron correlations that are consistent with stripe formation. Both the scattering due to the polaron correlations and the anomalous quasielastic component in the magnetic fluctuation spectrum maximize very close to Tc, in a manner remarkably similar to the resistivity, indicating that they have a common origin. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Moscow Steel & Alloys Inst, Moscow 117936, Russia. RP Adams, CP (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Shulyatev, Dmitry/M-7278-2014 OI Shulyatev, Dmitry/0000-0002-7642-0277 NR 36 TC 188 Z9 188 U1 2 U2 18 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 30 PY 2000 VL 85 IS 18 BP 3954 EP 3957 DI 10.1103/PhysRevLett.85.3954 PG 4 WC Physics, Multidisciplinary SC Physics GA 368ZA UT WOS:000090146300053 ER PT J AU Lee, S Leone, SR AF Lee, S Leone, SR TI Rate coefficients for the reaction of C2H with O-2 at 90 K and 120 K using a pulsed Laval nozzle apparatus SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RATE-CONSTANT MEASUREMENTS; SPECTROSCOPY; ATMOSPHERE; MECHANISM; RADICALS; CO AB Absolute rate coefficients for the reaction of C2H with O-2 are measured at 90 K and 120 K by using a pulsed Laval nozzle apparatus with laser ionization, time-of-flight mass spectrometry (TOF-MS). The C2H radicals are generated by laser photolysis of C2H2 at 193 nm, and the products of the reaction with O-2 and C2H2, HCCO and C4H2, respectively, are directly detected by laser ionization at 118 nm. Rate coefficients of (9.0+/-2.0) x 10(-11) and (5.0 +/- 1.5) x 10(-11) cm(3) molecule(-1) s(-1) are obtained at 90 K and 120 K for the C2H + O-2 reaction, respectively, by detecting the rise of the product HCCO. (C) 2000 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. NR 23 TC 22 Z9 22 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 27 PY 2000 VL 329 IS 5-6 BP 443 EP 449 DI 10.1016/S0009-2614(00)01022-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 371EA UT WOS:000165164000018 ER PT J AU Wang, SL Shi, Y Gorshkova, I Schwarz, FP AF Wang, SL Shi, Y Gorshkova, I Schwarz, FP TI RNA polymerase-cNMP-ligated cAMP receptor protein (CRP) mutant interactions in the enhancement of transcription by CRP mutants SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID CAP-DNA COMPLEX; ESCHERICHIA-COLI; ACTIVATOR PROTEIN; LAC PROMOTER; BINDING; MUTATIONS; IDENTIFICATION; PURIFICATION; POSITION-127; OPERON AB The enhancement of the transcription of three synthetic promoters by cNMP-ligated cAMP receptor protein (CRP)/mutant complexes was determined from the transcription yields of a short AAUU transcript in an abortive initiation in vitro transcription assay, The cNMP-ligated CRP and mutants were cAMP, cGMP, and cIMP ligated with CRP, T127L CRP, S128A CRP, and T127L/S128A CRP, The transcriptional activation of a 152-base pair lacUV5 promoter (synlac promoter) with a CRP consensus binding site sequence (syncon promoter) was enhanced by an average factor of 12.3 +/- 0.5 with the cAMP-ligated complexes of CRP/mutants and cGMP-ligated T127L, although their promoter binding site affinities varied by a factor of 5. However, in the presence of bound RNA polymerase, the binding affinities only ranged from 0.8 +/- 0.2 x 10(7) M-1 for cAMP-ligated CRP* to 1.8 +/- 0.3 x 10(7) M-1 for cAMP-ligated CRP, indicating that the CRP/mutant interacts with the bound RNA polymerase, which would account for the near constancy of the enhancement factors. The corresponding enhancement factors for the synlac promoter and a promoter with a different CRP binding site sequence (syngal promoter) were also nearly the same, 7.2 +/- 0.7 and 6 +/- 1, respectively, The binding reaction of the syncon promoter to the RNA polymerase is exothermic, with a binding constant (K-b) = 2.1 +/- 0.2 x 10(7) m(-1). C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Schwarz, FP (reprint author), NIST, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 27 TC 5 Z9 5 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 27 PY 2000 VL 275 IS 43 BP 33457 EP 33463 DI 10.1074/jbc.M004877200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 368EK UT WOS:000090104600040 PM 10934201 ER PT J AU Chin, M Savoie, DL Huebert, BJ Bandy, AR Thornton, DC Bates, TS Quinn, PK Saltzman, ES De Bruyn, WJ AF Chin, M Savoie, DL Huebert, BJ Bandy, AR Thornton, DC Bates, TS Quinn, PK Saltzman, ES De Bruyn, WJ TI Atmospheric sulfur cycle simulated in the global model GOCART: Comparison with field observations and regional budgets SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHARACTERIZATION EXPERIMENT ACE-1; MARINE BOUNDARY-LAYER; SEA-SALT SULFATE; DIMETHYL-SULFIDE; PACIFIC-OCEAN; TRANSPORT; DIOXIDE; SO2; CHEMISTRY; EMISSIONS AB We present a detailed evaluation of the atmospheric sulfur cycle simulated in the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model. The model simulations of SO2, sulfate? dimethylsulfide (DMS), and methanesulfonic acid (MSA) are compared with observations from different regions on various timescales. The model agrees within 30% with the regionally averaged sulfate concentrations measured over North America and Europe but overestimates the SO2 concentrations by more than a factor of 2 there. This suggests that either the emission rates are too high, or an additional loss of SO2 which does not lead to a significant sulfate production is needed. The average wintertime sulfate concentrations over Europe in the model are nearly a factor of 2 lower than measured values, a discrepancy which may be attributed largely to the sea-salt sulfate collected in the data. The model reproduces the sulfur distributions observed over the oceans in both long-term surface measurements and short-term aircraft campaigns. Regional budget analyses show that sulfate production from SO2 oxidation is 2 to 3 times more efficient and the lifetimes of SO2 and sulfate are nearly a factor of 2 longer over the ocean than over the land. This is due to a larger free tropospheric fraction of SO2 column over the ocean than over the land, hence less loss to the surface. The North Atlantic and northwestern Pacific regions are heavily influenced by anthropogenic activities? with more than 60% of the total SO2 originating from anthropogenic sources. The average production efficiency of SO2 from DMS oxidation is estimated at 0.87 to 0.91. in most oceanic regions. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Chin, M (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM chin@rondo.gsfc.nasa.gov; dsavoie@rsmas.miami.edu; huebert@soest.hawaii.edu; bandyar@drexel.edu; dct@drexel.edu; bates@pmel.noaa.gov; quinn@pmel.noaa.gov; esaltzma@nsf.gov; debruyn@rsmas.miami.edu RI Chin, Mian/J-8354-2012; Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 50 TC 82 Z9 83 U1 2 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2000 VL 105 IS D20 BP 24689 EP 24712 DI 10.1029/2000JD900385 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367NQ UT WOS:000090068700006 ER PT J AU Yu, SC Saxena, VK Wenny, BN DeLuisi, JJ Yue, GK Petropavlovskikh, IV AF Yu, SC Saxena, VK Wenny, BN DeLuisi, JJ Yue, GK Petropavlovskikh, IV TI A study of the aerosol radiative properties needed to compute direct aerosol forcing in the southeastern United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL DEPTH; ANTHROPOGENIC AEROSOLS; SIZE DISTRIBUTION; NORTH-CAROLINA; CLIMATE; US; UNCERTAINTY; SHORTWAVE; IMPACT; INDEX AB To assess the direct radiative forcing due to aerosols in southeastern United States where a mild cooling is under way, an accurate set of data describing the aerosol radiative properties are needed. We report here aerosol optical depth (AOD) and diffuse-to-direct solar irradiance ratio (DDR) at three operational wavelengths (415, 500, 673 nm) determined by using Multifilter Rotating Shadowband Radiometers (MFRSR) at two sites (a mountain top site: Mount Gibbes, 35,78 degreesN, 82.29 degreesW, 2006 m mean sea level (msl); a valley site: Black Mountain, 35,66 degreesN, 82.38 degreesW, 951 m msl), which are separated horizontally by 10 km and vertically by 1 km. The characteristics AOD and DDR were determined from the field measurements obtained during 1995, It was found that the representative total AOD values at 500 nm at the valley site for highly polluted (HP), marine (M) and continental (C) air masses were 0.68 +/- 0.33, 0.29 +/- 0.19, and 0.10 +/- 0,04, respectively. The fact that the ratio of the mean 1 km layer optical depth to total mean optical depth at 500 nm from the valley site was 71% indicates that the major portion of the atmospheric aerosol was located in the lowest 1 km surface boundary layer (SBL). There was a significant linear correlation between the DDR and the total AOD at both sites. A simple, fast, and operative search-graph method was used to retrieve the columnar size distribution (number concentration N, effective radius r(eff), and geometric standard deviation a) from the optical depth observations at the three operational wavelengths. The ground albedo, single-scattering albedo, and imaginary part of the refractive index are calculated using a mathematically unique procedure involving a Mie code and a radiative transfer code in conjunction with the retrieved aerosol size distribution, AOD, and DDR, It was found that N, r(eff) and sigma (g) were in the range of 1.9 x 10 to 1.7 x 10(4) cm(-3), 0.09-0.68 mum, and 1.12-2.70, respectively. The asymmetry factor and single-scattering albedo were in the ranges of 0.63-0.75 and 0.74-0.99 respectively. The ground albedo over the forested terrain and the imaginary part of refractive index were found to be in the range of 0.08-0.29 and 0,005-0.051, respectively. C1 NOAA, Surface Radiat Res Branch, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80302 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Yu, SC (reprint author), Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. EM saxena@eos.ncsu.edu RI yu, shaocai/G-7806-2011; yu, shaocai/F-1394-2014 NR 37 TC 24 Z9 24 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2000 VL 105 IS D20 BP 24739 EP 24749 DI 10.1029/2000JD900346 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367NQ UT WOS:000090068700010 ER PT J AU Skripov, AV Udovic, TJ Huang, Q Cook, JC Kozhanov, VN AF Skripov, AV Udovic, TJ Huang, Q Cook, JC Kozhanov, VN TI Neutron diffraction study of the location of deuterium in the deuterium-stabilized ZrTi2D3.83 phase SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE metal hydrides; laves phases; neutron powder diffraction ID HYDROGEN MOTION; SCATTERING; LATTICE AB The location of D atoms in the deuterium-stabilized ZrTi2D3.83 phase with CIS-type host lattice has been studied by neutron diffraction in the temperature range 11-300 K. It is found that D atoms occupy two types of sites of the space group Fd (3) over bar m: 32e (ZrTi3) and 96g (Zr2Ti2). Most of the deuterium atoms are located in 32e sites. The occupancy of these sites is found to increase from 0.81 at 300 K to 0.94 a; 11 K. Thus, as the temperature decreases, the ZrTi2-D system approaches the fully ordered state with the completely occupied sublattice of 32e sites. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Russian Acad Sci, Inst Met Phys, Urals Branch, Ekaterinburg 620219, Russia. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Skripov, AV (reprint author), Russian Acad Sci, Inst Met Phys, Urals Branch, Ekaterinburg 620219, Russia. RI Skripov, Alexander/K-4525-2013 OI Skripov, Alexander/0000-0002-0610-5538 NR 18 TC 13 Z9 14 U1 0 U2 1 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 OCT 26 PY 2000 VL 311 IS 2 BP 234 EP 237 DI 10.1016/S0925-8388(00)01108-7 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 360NF UT WOS:000089673600023 ER PT J AU Mate, B Walker, AH Suenram, RD Craig, NC AF Mate, B Walker, AH Suenram, RD Craig, NC TI Complete structure of gauche 1,1,2,2-tetrafluoroethane determined by microwave spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID RESOLUTION INFRARED-SPECTROSCOPY; MOLECULAR-BEAM; DIPOLE-MOMENTS; 1,2-DIFLUOROETHANE; SPECTRA; TRANS-1,2-DIFLUOROETHYLENE; CONFORMATIONS AB The complete molecular structure of the high-energy gauche rotamer of 1,1,2,2-tetrafluoroethane (TFEA), Freon F134, has been determined using pulsed-molecular-beam Fourier transform microwave spectroscopy. Five different C-13- and H-2-substituted isotopomers, in addition to the normal species, were studied. Unlike the nonpolar anti rotamer, the gauche form has a permanent electric dipole moment, which permits a direct rotational analysis. The electric dipole moment was also determined using the Stark effect of two low-J transitions. The resulting dipole moment is mu (c) = 8.186(7) x 10(-30) C m [2.454(2) Debye] where the numbers in parentheses are the standard uncertainties (i.e., 1 sigma). The experimental results for the geometric parameters of TFEA are compared with two recent ab initio calculations. C1 Oberlin Coll, Dept Chem, Oberlin, OH 44074 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Craig, NC (reprint author), Oberlin Coll, Dept Chem, Oberlin, OH 44074 USA. RI Mate, Belen/F-1135-2016 OI Mate, Belen/0000-0002-5478-8644 NR 23 TC 4 Z9 4 U1 3 U2 4 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 OCT 26 PY 2000 VL 104 IS 42 BP 9489 EP 9493 DI 10.1021/jp001913i PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 369QD UT WOS:000165077700013 ER PT J AU Silverstein, JT Wolters, WR Shimizu, M Dickhoff, WW AF Silverstein, JT Wolters, WR Shimizu, M Dickhoff, WW TI Bovine growth hormone treatment of channel catfish: strain and temperature effects on growth, plasma IGF-I levels, feed intake and efficiency and body composition SO AQUACULTURE LA English DT Article DE recombinant growth hormone; genetic effects; temperature effects ID SALMON ONCORHYNCHUS-KISUTCH; FOOD-INTAKE; INSULIN; CHICKEN; TSHAWYTSCHA; FAT; PERFORMANCE; ENDOCRINE; RESPONSES; INJECTION AB Channel catfish from two strains, USDA-103 and Norris, were reared in circular 800-1 tanks and injected once weekly with 2.5 mu g recombinant bovine growth hormone (rbGH) per gram body weight, or the saline vehicle. In addition to the rbGH, and strain treatments, half the tanks were supplied with well water of 26.0 degrees C and the other half received water of 21.7 degrees C. Growth rate, plasma insulin-like growth factor I (IGF-I) levels, feed consumption and body fatness of the fish injected with rbGH were higher than in saline-injected controls. Strain and temperature effects were also significant. Feed consumption was significantly greater with growth hormone treatment, higher temperature, and in the USDA-103 strain of catfish. Feed efficiency was significantly better in rbGH-injected fish. The effect of temperature on feed efficiency was also significant, higher temperature treatments performed better. Growth hormone enabled channel catfish to grow better at lower and higher temperatures than saline-treated counterparts. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ARS, USDA, Catfish Genet Res Unit, Thad Cochran Natl Warmwater Aquaculture Ctr, Stoneville, MS 38776 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Silverstein, JT (reprint author), ARS, USDA, Catfish Genet Res Unit, Thad Cochran Natl Warmwater Aquaculture Ctr, POB 38, Stoneville, MS 38776 USA. NR 40 TC 78 Z9 83 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD OCT 25 PY 2000 VL 190 IS 1-2 BP 77 EP 88 DI 10.1016/S0044-8486(00)00387-2 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 349AP UT WOS:000089021900006 ER PT J AU Tarek, M Martyna, GJ Tobias, DJ AF Tarek, M Martyna, GJ Tobias, DJ TI Amplitudes and frequencies of protein dynamics: Analysis of discrepancies between neutron scattering and molecular dynamics simulations SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TEMPERATURE-DEPENDENCE; SUPEROXIDE-DISMUTASE; GLOBULAR PROTEIN; GLASS-TRANSITION; HYDRATION WATER; MYOGLOBIN; MOTIONS; BACTERIORHODOPSIN; BEHAVIOR; SPECTROSCOPY C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RP Tobias, DJ (reprint author), Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RI Tobias, Douglas/B-6799-2015 NR 36 TC 41 Z9 42 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 25 PY 2000 VL 122 IS 42 BP 10450 EP 10451 DI 10.1021/ja0016506 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 368UZ UT WOS:000090137000021 ER PT J AU Wen, YH Wang, Y Bendersky, LA Chen, LQ AF Wen, YH Wang, Y Bendersky, LA Chen, LQ TI Microstructural evolution during the alpha(2)->alpha(2)+O transformation in Ti-Al-Nb alloys: Phase-field simulation and experimental validation SO ACTA MATERIALIA LA English DT Article DE computer simulation; phase transformations; precipitation; Ti-Al-Nb alloys; microstructure ID HIGH-TEMPERATURE PHASES; ORTHORHOMBIC STRUCTURES; COMPUTER-SIMULATION; TI-24AL-15NB ALLOY; EXPERIMENTAL TEM; SYSTEM; TI3AL; BCC; HCP AB The microstructural development during precipitation of a coherent orthorhombic phase (O-phase) from an alpha (2) matrix (DO19) in a Ti-Al-Nb system is investigated through computer simulations using the phase-held approach and through experimental observations using transmission electron microscopy (TEM). Two compositions were considered in the simulations in order to examine the influence of volume fraction of the O-phase on the microstructure. It is found that in the alloy with higher volume fraction of the O-phase, the precipitates have either square or rectangular shapes on (0001)(alpha2) or (001)(O) planes. All the particles are interconnected by sharing their corners. In the alloy with lower volume fraction, the dominant morphology for the precipitates is thin plate. The spatial distribution of precipitates is highly non-uniform with the precipitates aggregating together to form various unique patterns to accommodate the elastic energy arising from the lattice misfit between the alpha (2) and O-phase. All the interfaces between the alpha (2) and O-phase are found to be undistorted habit planes of the type {470)(O), and the domain boundaries between different orientation variants of the O-phase are twin boundaries which are the strain-free planes {110)(O) or {130)(O). The simulation predictions agree remarkably well with existing experimental observations and the concurrent TEM study. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. RP Wen, YH (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI Wang, Yunzhi/B-2557-2010; Chen, LongQing/I-7536-2012 OI Chen, LongQing/0000-0003-3359-3781 NR 23 TC 39 Z9 41 U1 3 U2 39 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 OCT 24 PY 2000 VL 48 IS 16 BP 4125 EP 4135 DI 10.1016/S1359-6454(00)00186-5 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 372XG UT WOS:000165258900012 ER PT J AU Dobson, CM Ellison, GB Tuck, AF Vaida, V AF Dobson, CM Ellison, GB Tuck, AF Vaida, V TI Atmospheric aerosols as prebiotic chemical reactors SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SELF-REPRODUCING VESICLES; ACIDS; PARTICLES; METEORITE; LIFE AB Aerosol particles in the atmosphere have recently been found to contain a large number of chemical elements and a high content of organic material. The latter property is explicable by an inverted micelle model. The aerosol sizes with significant atmospheric lifetimes are the same as those of single-celled organisms, and they are predicted by the interplay of aerodynamic drag, surface tension, and gravity. We propose that large populations of such aerosols could have afforded an environment, by means of their ability to-concentrate molecules in a wide variety of physical conditions, for key chemical transformations in the prebiotic world. We also suggest that aerosols could have been precursors to life, since it is generally agreed that the common ancestor of terrestrial life Was a single-celled organism, The early steps in some of these initial transformations should be accessible to experimental investigation. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Oxford, Oxford Ctr Mol Sci, New Chem Lab, Oxford OX1 3QT, England. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Tuck, AF (reprint author), NOAA, Aeron Lab, David Skaggs Bldg,325 Broadway, Boulder, CO 80305 USA. RI Tuck, Adrian/F-6024-2011; Vaida, Veronica/N-6069-2014 OI Tuck, Adrian/0000-0002-2074-0538; Vaida, Veronica/0000-0001-5863-8056 NR 39 TC 109 Z9 111 U1 4 U2 32 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 24 PY 2000 VL 97 IS 22 BP 11864 EP 11868 DI 10.1073/pnas.200366897 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 367PQ UT WOS:000090071000031 PM 11035775 ER PT J AU Belmonte, A AF Belmonte, A TI Feasibility study for the simulation of beam propagation: consideration of coherent lidar performance SO APPLIED OPTICS LA English DT Article ID 3-DIMENSIONAL RANDOM-MEDIA; ATMOSPHERIC-TURBULENCE; REFRACTIVE-TURBULENCE; WAVE-PROPAGATION; GAUSSIAN-BEAM; PHASE-SCREEN; OPTICAL-BEAM; POINT-SOURCE; SPECTRUM; INTENSITY AB To analyze the effects of atmospheric refractive turbulence on coherent lidar performance in a realistic way it is necessary to consider the use of simulations of beam propagation in three-dimensional random media. The capability of the split-step solution to simulate the propagation phenomena is shown, and the limitations and numerical requirements for a simulation of given accuracy are established. Several analytical theories that describe laser beam spreading, beam wander, coherence diameters, and variance and autocorrelation of the beam intensity are compared with results from simulations. Although the analysis stems from a study of coherent lidar performance, the conclusions of the method are applicable to other areas related to beam propagation in the atmosphere. (C) 2000 Optical Society of America OCIS codes: 010.3640, 010.1300, 010.1330, 030.1670. C1 Univ Politecn Cataluna, Dept Signal Theory & Communicat, ES-08034 Barcelona, Spain. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Belmonte, A (reprint author), Univ Politecn Cataluna, Dept Signal Theory & Communicat, Campus Nord,Bldg D3,C Jordi Girona 1-3, ES-08034 Barcelona, Spain. EM belmonte@tsc.upc.es NR 59 TC 66 Z9 75 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 2000 VL 39 IS 30 BP 5426 EP 5445 DI 10.1364/AO.39.005426 PG 20 WC Optics SC Optics GA 364ZV UT WOS:000089924700004 PM 18354539 ER PT J AU Devine, D Grady, CA Kimble, RA Woodgate, B Bruhweiler, FC Boggess, A Linsky, JL Clampin, M AF Devine, D Grady, CA Kimble, RA Woodgate, B Bruhweiler, FC Boggess, A Linsky, JL Clampin, M TI A Ly alpha bright jet from a Herbig Ae star SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems; stars : individual (HD 163296); stars : pre-main-sequence ID YOUNG STELLAR OBJECTS; AE/BE STARS; HARO OBJECTS; OUTFLOWS; EMISSION; SPECTRA; MODELS; WINDS AB We report the detection in Ly alpha of a collimated, bipolar outflow (HH 409) associated with the 1.5-10 Myr old Herbig Ae star HD 163296. A blueshifted jet is visible in Ly alpha and Si III extending toward the southwest for at least 6" (725 AU). The combination of low line-of-sight extinction and relative faintness of the central star near Ly alpha enables us to trace the jet to within an unprecedented 0".06 (7.3 AU) of HD 163296. The jet has a radial velocity of 335-380 km s(-1), which is common for protostellar outflows. We also detected redshifted Ly alpha emission southwest of the star that may be due to infall or a poorly collimated wind component. If the age of the star is correct, then protostellar outflows may last up to 10 times longer than previously believed. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Devine, D (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. RI Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012 NR 23 TC 46 Z9 46 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP L115 EP L118 DI 10.1086/312939 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YQ UT WOS:000165095700010 ER PT J AU Coxon, B AF Coxon, B TI Boat conformations. Analysis and simulation of the complex H-1 NMR spectrum of methyl 2,6 : 3,4-dianhydro-alpha-D-altropyranoside SO CARBOHYDRATE RESEARCH LA English DT Article DE altropyranoside; boat conformations; carbon-13-proton chemical shift correlation; 2,6 : 3,4-dianhydride; gradient-enhanced 2D HSQC; long-range coupling constants; molecular dynamics; simulated annealing; spin-lattice relaxation times ID SPECTROSCOPY; ENHANCEMENT; FIELD AB The complex H-1 NMR spectrum of methyl 2,6:3,4-dianhydro-alpha-D-altropyranoside (1) has been analyzed and simulated in detail by using input parameters derived from experimental H-1 chemical shifts, long- and short-range coupling constants, spin-lattice relaxation times, and effective, spin-spin relaxation times obtained by trial and error matching of the experimental and simulated spectra. The C-13 spin-lattice relaxation times of 1 have also been measured, and along with the H-1-H-1 long- and short-range coupling constants, have been interpreted in terms of the geometry of 1 defined by molecular dynamics with simulated annealing. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Coxon, B (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr Stop 8311, Gaithersburg, MD 20899 USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD OCT 20 PY 2000 VL 329 IS 1 BP 131 EP 139 DI 10.1016/S0008-6215(00)00173-7 PG 9 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA 365CN UT WOS:000089931000014 PM 11086693 ER PT J AU Brown, CM Yildirim, T Neumann, DA Heben, MJ Gennett, T Dillon, AC Alleman, JL Fischer, JE AF Brown, CM Yildirim, T Neumann, DA Heben, MJ Gennett, T Dillon, AC Alleman, JL Fischer, JE TI Quantum rotation of hydrogen in single-wall carbon nanotubes SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GRAPHITE NANOFIBERS; LASER VAPORIZATION; SOLID C-60; ADSORPTION; STORAGE; H-2; ENERGY AB We report inelastic neutron scattering results on hydrogen adsorbed onto samples containing single-wall carbon nanotubes. These materials have attracted considerable interest recently due to reports of high density hydrogen storage at room temperature. Inelastic neutron scattering clearly shows the ortho-para conversion of physisorbed hydrogen in a nanotube containing soot loaded with hydrogen. From the rotational J = 0 --> 1 transition, no indication of a significant barrier to quantum rotation is seen. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD USA. Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Rochester Inst Technol, Ctr Mat Sci & Engn, Rochester, NY 14623 USA. RP Neumann, DA (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI yildirim, taner/A-1290-2009; Brown, Craig/B-5430-2009 OI Brown, Craig/0000-0002-9637-9355 NR 27 TC 118 Z9 120 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 20 PY 2000 VL 329 IS 3-4 BP 311 EP 316 DI 10.1016/S0009-2614(00)01003-4 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 367WX UT WOS:000090085500019 ER PT J AU Brown, JM Buenker, RJ Carrington, A Di Lauro, C Dixon, RN Field, RW Hougen, JT Huttner, W Kuchitsu, K Mehring, M Merer, AJ Miller, TA Quack, M Ramsay, DA Veseth, L Zare, RN AF Brown, JM Buenker, RJ Carrington, A Di Lauro, C Dixon, RN Field, RW Hougen, JT Huttner, W Kuchitsu, K Mehring, M Merer, AJ Miller, TA Quack, M Ramsay, DA Veseth, L Zare, RN TI Remarks on the signs of g factors in atomic and molecular Zeeman spectroscopy SO MOLECULAR PHYSICS LA English DT Article AB Various magnetic moments, associated with rotational, vibrational, nuclear spin, electron orbital and electron spin angular momenta, can contribute to the Zeeman effect in atoms and molecules. They are considered in this paper in the context of the effective Hamiltonian where relativistic and other corrections as well as the effects of mixing with other electronic states are absorbed in appropriate g factors. In spherically symmetric systems, the magnetic dipole moment arising from a specific angular momentum can be written as the product of three factors: the nuclear or Bohr magneton (which is positive), the g factor (which may be positive or negative), and the corresponding angular momentum (which is a vector). A convention is discussed, in which the sign of the g factor is positive when the dipole moment is parallel to its angular momentum and negative when it is antiparallel. This would have the advantage that it could be applied consistently in any situation. Such a choice would require the g factors for the electron orbital and electron spin angular momenta to be negative. This concept can easily be extended to the case of a general molecule where the relation between the dipole and angular momentum vectors has tensorial character. C1 Univ Ulm, Phys Chem Abt, D-89069 Ulm, Germany. Univ Oxford, Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. Berg Univ Gesamthsch Wuppertal, D-42097 Wuppertal, Germany. Univ Southampton, Dept Chem, Southampton SO9 5NH, Hants, England. Univ Naples Federico II, Dipartimento Chim Farmaceut & Tossicol, I-80131 Naples, Italy. Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England. MIT, Dept Chem, Cambridge, MA 02139 USA. NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Josai Univ, Dept Chem, Sakado, Saitama 3500295, Japan. Univ Stuttgart, Inst Phys 2, D-70550 Stuttgart, Germany. Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada. Ohio State Univ, Dept Chem, Newman & Wolfrom Lab, Columbus, OH 43210 USA. ETH Zentrum, Chem Phys Lab, CH-8092 Zurich, Switzerland. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Univ Oslo, Dept Phys, N-0316 Oslo 3, Norway. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Huttner, W (reprint author), Univ Ulm, Phys Chem Abt, D-89069 Ulm, Germany. RI Zare, Richard/A-8410-2009; Miller, Terry/F-6607-2014; Quack, Martin/H-4457-2016 OI Miller, Terry/0000-0003-0731-8006; NR 33 TC 3 Z9 3 U1 1 U2 1 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 OCT 20 PY 2000 VL 98 IS 20 BP 1597 EP 1601 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 363DH UT WOS:000089819200001 ER PT J AU Weber, DS Stewart, BS Garza, JC Lehman, N AF Weber, DS Stewart, BS Garza, JC Lehman, N TI An empirical genetic assessment of the severity of the northern elephant seal population bottleneck SO CURRENT BIOLOGY LA English DT Article ID DNA; DIVERSITY; EVOLUTION AB A bottleneck in population size of a species is often correlated with a sharp reduction in genetic variation, The northern elephant seal (Mirounga angustirostris) has undergone at least one extreme bottleneck, having rebounded from 20-100 individuals a century ago to over 175,000 individuals today. The relative lack of molecular-genetic variation in contemporary populations has been documented, but the extent of variation before the late 19th century remains unknown. We have determined the nucleotide sequence of a 179 base-pair segment of the mitochondrial DNA (mtDNA) control region from seals that lived before, during and after a bottleneck low in 1892. A 'primerless' PCR was used to improve the recovery of information from older samples. Only two mtDNA genotypes were present in all 150+ seals from the 1892 bottleneck on, but we discovered four genotypes in five pre-bottleneck seals. This suggests a much greater amount of mtDNA genotypic variation before this bottleneck, and that the persistence of two genotypes today is a consequence of random lineage sampling. We cannot correlate the loss of mtDNA genotypes with a lowered mean fitness of individuals in the species today. However, we show that the species historically possessed additional genotypes to those present now, and that sampling of ancient DNA could elucidate the genetic consequences of severe reductions in population size. C1 SUNY Albany, Dept Biol Sci, Albany, NY 12222 USA. Hubbs Seaworld Res Inst, San Diego, CA 92109 USA. US Dept State, Off Marine Convers, Bur Oceans Environm & Sci, Washington, DC 20520 USA. Natl Marine Fisheries Serv, Long Marine Lab, Santa Cruz, CA 95060 USA. RP Lehman, N (reprint author), SUNY Albany, Dept Biol Sci, 1400 Washington Ave, Albany, NY 12222 USA. RI Lehman, Niles/A-3434-2008; Weber, Diana/O-1059-2016 OI Weber, Diana/0000-0002-6459-9695 NR 17 TC 62 Z9 63 U1 3 U2 32 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0960-9822 J9 CURR BIOL JI Curr. Biol. PD OCT 19 PY 2000 VL 10 IS 20 BP 1287 EP 1290 DI 10.1016/S0960-9822(00)00759-4 PG 4 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 366YR UT WOS:000090034300020 PM 11069110 ER PT J AU Werner, RM Jiang, YL Gordley, RG Jagadeesh, GJ Ladner, JE Xiao, GY Tordova, M Gilliland, GL Stivers, JT AF Werner, RM Jiang, YL Gordley, RG Jagadeesh, GJ Ladner, JE Xiao, GY Tordova, M Gilliland, GL Stivers, JT TI Stressing-out DNA? The contribution of serine-phosphodiester interactions in catalysis by uracil DNA glycosylase SO BIOCHEMISTRY LA English DT Article ID SITE-DIRECTED MUTAGENESIS; BASE-EXCISION-REPAIR; CHIRAL PHOSPHOROTHIOATES; MECHANISM; KINETICS; BINDING; DAMAGE AB The DNA repair enzyme uracil DNA glycosylase (UDG) pinches the phosphodiester backbone of damaged DNA using the hydroxyl side chains of a conserved trio of serine residues, resulting in flipping of the deoxyuridine from the DNA helix into the enzyme active site. We have investigated the energetic role of these serine-phosphodiester interactions using the complementary approaches of crystallography, directed mutagenesis, and stereospecific phosphorothioate substitutions. A new crystal structure of UDG bound to 5'-HO-dUAAp-3' (which lacks the 5' phosphodiester group that interacts with the Ser88 pinching finger) shows that the glycosidic bond of dU has been cleaved, and that the enzyme has undergone the same specific clamping motion that brings key active site groups into position as previously observed in the structures of human UDG bound to large duplex DNA substrates. From this structure, it may be concluded that glycosidic bond cleavage and the induced fit conformational change in UDG can occur without the 5' pinching interaction. The S88A, S189A, and S192G "pinching" mutations exhibit 360-, 80-, and 21-fold damaging effects on k(cat)/K-m, respectively, while the S88A/S189A double mutant exhibits an 8200-fold damaging effect. A free energy analysis of the combined effects of nonbridging phosphorothioate substitution and mutation at these positions reveals the presence of a modest amount of strain energy between the compressed 5' and 3' phosphodiester groups flanking the bound uridine. Overall, these results indicate a role for these serine-phosphodiester interactions in uracil flipping and preorganization of the sugar ring into a reactive conformation. However, in contrast to a recent proposal [Parikh, S. S., et al. (2000) Proc Natl. Acad. Scf. 94, 5083], there is no evidence that conformational strain of the glycosidic bond induced by serine pinching plays a major role in the 10(12)-fold rate enhancement brought about by UDG. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. RP Stivers, JT (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. FU NIGMS NIH HHS [R01 GM056834, R01 GM56834] NR 30 TC 57 Z9 58 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 17 PY 2000 VL 39 IS 41 BP 12585 EP 12594 DI 10.1021/bi001532v PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 372BQ UT WOS:000165214100009 PM 11027138 ER PT J AU Lenhart, JL van Zanten, JH Dunkers, JP Parnas, RS AF Lenhart, JL van Zanten, JH Dunkers, JP Parnas, RS TI Interfacial response of a fluorescent dye grafted to glass SO LANGMUIR LA English DT Article ID EXCIMER FLUORESCENCE; BLEND MISCIBILITY; MOLECULAR PROBE; POLY(METHYL METHACRYLATE); TRANSITION TEMPERATURE; POLYMER SURFACES; WATER-ADSORPTION; EPOXY CURE; MOBILITY; FILMS AB The properties of an epoxy/glass interfacial region are studied by covalently grafting a fluorescent probe to the glass surface. A dimethylaminonitrostilbene fluorophore is tethered to a triethoxysilane-coupling agent, generating a fluorescently labeled silane coupling agent (FLSCA). The glass surface is coated with a silane layer that was doped with small amounts of FLSCA. When the FLSCA-doped, silane-coated glass is immersed in epoxy resin, a 42-nm blue shift in fluorescence occurs during resin cure over the grafted FLSCA layer. When the dye is dissolved in bulk epoxy a 64-nm blue shift occurs during resin cure. The difference in blue shift is attributed to higher polarity and enhanced mobility in the buried interface. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. RP Parnas, RS (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 57 TC 15 Z9 15 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 17 PY 2000 VL 16 IS 21 BP 8145 EP 8152 DI 10.1021/la000553n PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 362VX UT WOS:000089799900039 ER PT J AU Lefebvre, AA Lee, JH Balsara, NP Hammouda, B AF Lefebvre, AA Lee, JH Balsara, NP Hammouda, B TI Neutron scattering from pressurized polyolefin blends near the limits of metastability SO MACROMOLECULES LA English DT Article ID POLYSTYRENE POLYVINYL METHYL-ETHER); MULTICOMPONENT POLYMER BLENDS; ORDER-DISORDER TRANSITION; BLOCK-COPOLYMER MELTS; THERMODYNAMIC INTERACTIONS; HYDROCARBON POLYMERS; INTERACTION PARAMETER; DIBLOCK COPOLYMER; MIXTURES; COMPRESSIBILITY AB Small-angle neutron scattering experiments were conducted on a series of off-critical binary polymethylbutylene/polyethylbutylene (PMB/PEB) blends over a wide range of blend compositions, component molecular masses, temperatures, and pressures. The blends become more immiscible with either decreasing temperature or increasing pressure. A simple extension of the Flory-Huggins theory that accounts for finite volume changes of mixing (DeltaV) is presented. Our extension demonstrates the validity of the usual mean-field theory of scattering from polymer mixtures based on the random phase approximation (RPA) at elevated pressures. We use this framework to analyze the temperature and pressure dependence of the small-angle neutron scattering profiles obtained from binary PMB/PEB blends. We propose that the volume change of mixing is a linear response to the repulsive interactions between monomers. We demonstrate that off-critical PMB/PEB blends can be undercooled or superpressurized deep into the metastable two-phase region (e.g., up to 50 degreesC undercooling) without detectable signs of phase separation. The chi parameters and the statistical segment lengths obtained by fitting the data obtained in the metastable region are within experimental error of those determined from stable, single-phase PMB/PEB blends well-removed from a phase boundary. This indicates that the concentration fluctuations in the metastable region of the phase diagram have a mean-field character similar to those in stable, single-phase blends that have been extensively characterized by the RPA-based theory. C1 Polytech Univ, Dept Chem Engn Chem & Mat Sci, Brooklyn, NY 11201 USA. NIST, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Balsara, NP (reprint author), Polytech Univ, Dept Chem Engn Chem & Mat Sci, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. NR 47 TC 25 Z9 25 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 17 PY 2000 VL 33 IS 21 BP 7977 EP 7989 DI 10.1021/ma000462x PG 13 WC Polymer Science SC Polymer Science GA 367ZH UT WOS:000090092300044 ER PT J AU Hayakawa, T Wang, JG Xiang, ML Li, XF Ueda, M Ober, CK Genzer, J Sivaniah, E Kramer, EJ Fischer, DA AF Hayakawa, T Wang, JG Xiang, ML Li, XF Ueda, M Ober, CK Genzer, J Sivaniah, E Kramer, EJ Fischer, DA TI Effect of changing molecular end groups on surface properties: Synthesis and characterization of poly(styrene-b-semifluorinated isoprene) block copolymers with -CF2H end groups SO MACROMOLECULES LA English DT Article ID DIBLOCK COPOLYMERS; SIDE-CHAINS; TENSIONS AB Poly(styrene-b-semifluorinated isoprene) block copolymers with -CF2H-terminated side groups were synthesized by the esterification reaction of a poly(styrene-b-hydroxylated 1,2-/3,4-isoprene) block copolymer with semifluorinated acid chlorides. Two distinct first-order transitions were observed by DSC measurements in the resulting block copolymers at temperatures below the glass transition of polystyrene. The transition temperatures of the longer fluorocarbon units (10 -CF2- units) were found to be higher than the shorter fluorocarbon units (eight -CF2- units). By comparing the block copolymers having -CF3 end groups with those with -CF2H end groups, it was found that both the thermal behavior and surface properties are significantly affected by the terminal group of the semifluorinated side chains in the block copolymer. NEXAFS spectroscopy reveals that, although the surface coverage by semifluorinated groups is roughly the same regardless of whether the ends are -CF2H or -CF3, the orientational order of the -CF2H surfaces is significantly poorer than that of the -CF3 surfaces. After long-term water exposure the -CF2H surfaces were observed to reconstruct to more hydrophilic ones even though the analogous polymers with -CF3-terminated semifluorinated side chains were quite stable. The ease of surface reconstruction is probably related to the relatively poor orientation order of the polymers with -CF2H end groups as determined by NEXAFS. C1 Cornell Univ, Ithaca, NY 14853 USA. Yamagata Univ, Grad Sch Engn, Yonezawa, Yamagata 992, Japan. NCSU, Dept Chem Engn, Raleigh, NC USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Hayakawa, T (reprint author), Cornell Univ, Ithaca, NY 14853 USA. NR 18 TC 48 Z9 49 U1 1 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 OCT 17 PY 2000 VL 33 IS 21 BP 8012 EP 8019 DI 10.1021/ma992112k PG 8 WC Polymer Science SC Polymer Science GA 367ZH UT WOS:000090092300049 ER PT J AU Holloway, JS Jakoubek, RO Parrish, DD Gerbig, C Volz-Thomas, A Schmitgen, S Fried, A Wert, B Henry, B Drummond, JR AF Holloway, JS Jakoubek, RO Parrish, DD Gerbig, C Volz-Thomas, A Schmitgen, S Fried, A Wert, B Henry, B Drummond, JR TI Airborne intercomparison of vacuum ultraviolet fluorescence and tunable diode laser absorption measurements of tropospheric carbon monoxide SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FAST-RESPONSE; MIXING RATIOS; OZONE; INSTRUMENT; PRECISION AB During the fall 1997 North Atlantic Regional Experiment (NARE 97), two separate intercomparisons of aircraft-based carbon monoxide measurement instrumentation were conducted. On September 2, CO measurements were simultaneously made aboard the National Oceanic and Atmospheric Administration (NOAA) WP-3 by vacuum ultraviolet (VUV) fluorescence and by tunable diode laser absorption spectroscopy (TDLAS), On September 18, an intercomparison flight was conducted between two separate instruments, both employing the VUV fluorescence method, on the NOAA WP-3 and the U,K. Meteorological Office C-130 Hercules. The results indicate that both of the VUV fluorescence instruments and the TDLAS system are capable of measuring ambient CO accurately and precisely with no apparent interferences in 5 s. The accuracy of the measurements, based upon three independent calibration systems, is indicated by the agreement to within 11% with systematic offsets of less than 1 ppbv. In addition, one of the groups participated in the Measurement of Air Pollution From Satellite (MAPS) intercomparison [Novelli ef at., 1998] with a different measurement technique but very similar calibration system, and agreed with the accepted analysis to within 5%. The precision of the measurements is indicated by the variability of the ratio of simultaneous measurements from the separate instruments, This variability is consistent with the estimated precisions of 1.5 ppbv and 2.2 ppbv for the 5 s average results of the C-130 and the WP-3 instruments, respectively, and indicates a precision of approximately 3.6% for the TDLAS instrument. The excellent agreement of the instruments in both intercomparisons demonstrates that significant interferences in the measurements are absent in air masses that ranged from 7 km in the midtroposphere to boundary layer conditions including subtropical marine air and continental outflow with embedded urban plumes. The intercomparison of the two VUV instruments that differed widely in their design indicates that the VUV fluorescence technique for CO measurements is not particularly sensitive to the details of its implementation. These intercomparisons help to establish the reliability of ambient CO measurements by the VUV fluorescence technique. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Forschungszentrum Julich, Inst Chem & Dynam Geosphare, D-52425 Julich, Germany. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Toronto, Dept Phys, Toronto, ON M5 51A7, Canada. RP Parrish, DD (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM parrish@al.noaa.gov; a.volz-thomas@kfa-juelich.de; jim@atmosp.physics.utoronto.ca RI Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Gerbig, Christoph/L-3532-2013; Drummond, James/O-7467-2014; Volz-Thomas, Andreas/J-7223-2012 OI Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; Gerbig, Christoph/0000-0002-1112-8603; Volz-Thomas, Andreas/0000-0003-3700-1667 NR 30 TC 106 Z9 106 U1 1 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2000 VL 105 IS D19 BP 24251 EP 24261 DI 10.1029/2000JD900237 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300006 ER PT J AU Cohen, RC Perkins, KK Koch, LC Stimpfle, RM Wennberg, PO Hanisco, TF Lanzendorf, EJ Bonne, GP Voss, PB Salawitch, RJ Del Negro, LA Wilson, JC McElroy, CT Bui, TP AF Cohen, RC Perkins, KK Koch, LC Stimpfle, RM Wennberg, PO Hanisco, TF Lanzendorf, EJ Bonne, GP Voss, PB Salawitch, RJ Del Negro, LA Wilson, JC McElroy, CT Bui, TP TI Quantitative constraints on the atmospheric chemistry of nitrogen oxides: An analysis along chemical coordinates SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IN-SITU MEASUREMENTS; INDUCED FLUORESCENCE INSTRUMENT; DIODE-LASER SPECTROMETER; NASA ER-2 AIRCRAFT; LOWER STRATOSPHERE; REACTIVE NITROGEN; SULFATE AEROSOLS; 2-DIMENSIONAL MODEL; INSITU MEASUREMENTS; OZONE DEPLETION AB In situ observations of NO2, NO, NOy, ClONO2, OH, O-3, aerosol surface area, spectrally resolved solar radiation, pressure and temperature obtained from the ER-2 aircraft during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) experiments are used to examine the factors controlling the fast photochemistry connecting NO and NO2 and the slower chemistry connecting NOx and HNO3. Our analysis uses "chemical coordinates" to examine gradients of the difference between a model and precisely calibrated measurements to provide a quantitative assessment of the accuracy of current photochemical models. The NO/NO2 analysis suggests that reducing the activation energy for the NO+O-3 reaction by 1.7 kJ/mol will improve model representation of the temperature dependence of the NO/NO2 ratio in the range 215-235 K. The NOx/HNO3 analysis shows that systematic errors in the relative rate coefficients used to describe NOx loss by the reaction OH + NO2 --> HNO3 and by the reaction set NO2+O-3-->NO3; NO2+NO3 --> N2O5; N2O5+H2O --> 2HNO(3) are in error by +8.4% (+30/-45%) (OH + NO2 too fast) in models using the Jet Propulsion Laboratory 1997 recommendations [DeMore et al., 1997]. Models that use recommendations for OH+NO2 and OH+HNO3 based on reanalysis of recent and past laboratory measurements are in error by 1.2% (+30/-45%) (OH + NO2 too slow). The +30%/-45% error limit reflects systematic uncertainties, while the statistical uncertainty is 0.65%. This analysis also shows that the POLARIS observations only modestly constrain the relative rates of the major NOx production reactions HNO3 + OH --> H2O + NO3 and HNO3 + hv --> OH + NO2. Even under the assumption that all other aspects of the model are perfect, the POLARIS observations only constrain the rate coefficient for OH+HNO3 to a range of 65% around the currently recommended value. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Colorado, Dept Chem, Boulder, CO 80309 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Div Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Denver, Dept Mech Engn, Denver, CO 80208 USA. Environm Canada, Downsview, ON M3H 5T4, Canada. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Cohen, RC (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM cohen@cchem.berkeley.edu RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; NR 80 TC 15 Z9 15 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 OCT 16 PY 2000 VL 105 IS D19 BP 24283 EP 24304 DI 10.1029/2000JD900290 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300008 ER PT J AU Longfellow, CA Ravishankara, AR Hanson, DR AF Longfellow, CA Ravishankara, AR Hanson, DR TI Reactive and nonreactive uptake on hydrocarbon soot: HNO3, O-3, and N2O5 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BLACK CARBON SOOT; LOWER STRATOSPHERE; HETEROGENEOUS REACTION; UPPER TROPOSPHERE; REACTION-KINETICS; OZONE; NO2; SURFACES; AEROSOLS; IONS AB The reactive and physical uptakes of HNO3, O-3, and N2O5 were examined on hydrocarbon soot by using a flow tube equipped with a chemical ionization mass spectrometer. The uptake of HNO3 at 298 K was found to be reversible, and it did not produce NO2 or NO; i.e., HNO3 was not reduced. The uptake of O-3 on to soot was measured at 298 and 253 K and found to be small when the surface area of the soot was taken into account. We conclude that neither the HNO3 nor the O-3 reaction on soot has much impact on the atmosphere. We observed the production of gas phase NO2 from the uptake of N2O5 on the soot surface with an efficiency of close to unity. It was concluded that the uptake of N2O5 on soot is reactive. The implications of the N2O5 reaction on soot to the atmosphere are not clear, because not all the products of this reactive uptake have been identified. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Longfellow, CA (reprint author), Philadelphia Univ, Dept Chem, Philadelphia, PA 19144 USA. EM longfellow@philau.edu; ravi@al.noaa.gov; dhanson@ucar.edu RI Ravishankara, Akkihebbal/A-2914-2011 NR 27 TC 44 Z9 46 U1 0 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2000 VL 105 IS D19 BP 24345 EP 24350 DI 10.1029/2000JD900297 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300012 ER PT J AU Feingold, G Kreidenweis, S AF Feingold, G Kreidenweis, S TI Does cloud processing of aerosol enhance droplet concentrations? SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CONDENSATION NUCLEI; DOPPLER RADAR; STRATOCUMULUS; TURBULENCE; DRIZZLE; GASES AB In this paper we explore phase space for cloud processing of cloud condensation nuclei (CCN) via heterogeneous chemistry. A range of input CCN size spectra, parameterized as lognormal distributions, are used as input to a parcel model driven along trajectories derived from a large-eddy simulation of the stratocumulus-capped marine boundary layer. A simple sulfate chemistry model is coupled to the microphysical model. Gas phase concentrations of SO2, O-3, H2O5, and NH3 are varied so as to generate one case for which SO2 processing is dominated by oxidation via O-3 and another case for which processing is dominated by oxidation via H2O2. The processed aerosol spectra are then used as input to an adiabatic parcel model that predicts the drop concentration for a given updraft velocity. Comparisons are made between predictions of drop concentration based on input of aerosol spectra that have experienced processing and an equivalent set that has not experienced processing. It is shown that for both of the chemical processing scenarios, heterogeneous processing can either enhance or suppress the number of drops activated in the subsequent cloud cycle, depending on the input CCN distribution and the magnitude of the updraft. Enhancement of drop concentration occurs in cases where the subsequent cloud cycle has low vertical velocity. A reduction in drop number occurs when updraft velocities in the subsequent cloud cycle are high. The size of the smallest CCN size category activated in the subsequent cloud cycle, relative to that experienced in the original cloud cycle, is important in determining the change in number of activated drops. By applying probability distribution functions of the vertical velocity, we calculate that,on average, drop concentrations are likely to be enhanced by between 10% and 20% for the cases examined. Nevertheless, the potential for both positive and negative changes in drop concentration due to cloud processing may complicate predictions of the indirect effect of aerosols on climate. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Feingold, G (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80305 USA. EM gfeingold@etl.noaa.gov RI Feingold, Graham/B-6152-2009; Kreidenweis, Sonia/E-5993-2011 OI Kreidenweis, Sonia/0000-0002-2561-2914 NR 15 TC 36 Z9 36 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2000 VL 105 IS D19 BP 24351 EP 24361 DI 10.1029/2000JD900369 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300013 ER PT J AU Parrish, DD Holloway, JS Jakoubek, R Trainer, M Ryerson, TB Hubler, G Fehsenfeld, FC Moody, JL Cooper, OR AF Parrish, DD Holloway, JS Jakoubek, R Trainer, M Ryerson, TB Hubler, G Fehsenfeld, FC Moody, JL Cooper, OR TI Mixing of anthropogenic pollution with stratospheric ozone: A case study from the North Atlantic wintertime troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PEM-WEST-A; CARBON-MONOXIDE; NASA DC-8; ATMOSPHERIC LAYERS; TROPOPAUSE FOLD; DISTRIBUTIONS; AIRCRAFT; SYSTEMS; FRONTS; SITES AB As part of the North Atlantic Regional Experiment (NARE), instrumentation for the measurement of O-3 and CO was included on research flights conducted by the National Oceanic and Atmospheric Administration WP-3D Orion aircraft from St. John' s, Newfoundland, Canada, and Keflavik, Iceland, from February 2 to 25, 1999. These flights sampled the lower troposphere over the western North Atlantic Ocean. One significant feature observed during these flights was the close proximity of air masses with contrasting source signatures: high levels of anthropogenic pollution immediately adjacent to elevated O-3, of stratospheric origin. Here we present a case study showing the most pronounced example of this proximity, which was associated with a frontal passage across North America and out into the North Atlantic region. Trajectory analyses and satellite imagery are used to investigate the transport mechanisms that create the interleaving of air masses from the different sources. One important chemical feature was noted: in air masses with differing amounts of anthropogenic pollution admired, O-3, was negatively correlated with CO, which indicates that emissions from surface anthropogenic sources had reduced O-3, in this wintertime period, even in air masses transported into the free troposphere. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. RP Parrish, DD (reprint author), NOAA, Aeron Lab, Boulder, CO 80305 USA. EM parrish@al.noaa.gov RI Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Cooper, Owen/H-4875-2013; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013 OI Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; NR 31 TC 43 Z9 43 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2000 VL 105 IS D19 BP 24363 EP 24374 DI 10.1029/2000JD900291 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300014 ER PT J AU Ramachandran, S Ramaswamy, V Stenchikov, GL Robock, A AF Ramachandran, S Ramaswamy, V Stenchikov, GL Robock, A TI Radiative impact of the Mount Pinatubo volcanic eruption: Lower stratospheric response SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID QUASI-BIENNIAL OSCILLATION; GENERAL-CIRCULATION MODEL; EL-CHICHON; MT-PINATUBO; NORTHERN-HEMISPHERE; OZONE DEPLETION; TEMPERATURE-CHANGES; TROPICAL OZONE; AEROSOL LAYER; CLIMATE AB Volcanic aerosols in the stratosphere produce significant transitory solar and infrared radiative perturbations, which warm the stratosphere, cool the surface and affect stratospheric circulation. In this study, using the Geophysical Fluid Dynamics Laboratory SKYHI general circulation model (GCM) with a high vertical resolution and a recently improved radiative transfer code, we investigate the aerosol radiative forcing and the stratospheric temperature response for the June 15, 1991, Mount Pinatubo eruption, the most well observed and largest volcanic eruption of the 20th Century. The investigation is carried out using an updated, comprehensive monthly and zonal-mean Pinatubo aerosol spectral optical properties data set. While the near-infrared solar spectral effects contribute substantially to the total stratospheric heating due to aerosols, over the entire global domain the longwave component exceeds the solar in causing a warming of the lower stratosphere (30-100 hPa). In contrast, the magnitude of the solar perturbation (increased reflection) in the overall surface-atmosphere radiative heat balance exceeds that due to the longwave (infrared trapping effect). The troposphere affects the stratospheric radiative forcing, mainly because of the dependence of the reflected solar and upward longwave radiation on cloudiness, and this adds to the uncertainty in the calculation of the stratospheric temperature response. A four-member ensemble of 2-year GCM integrations (June 1991 to May 1993) were performed using fixed sea surface temperatures and a cloud prediction scheme, one set with and another without the volcanic aerosols. The temperature of the tropical lower stratosphere increases by a statistically significant 3 K, which is almost 1 K less than in previous investigations that employed coarser vertical resolution in the stratosphere, but is still larger than observed. In the low latitudes the evolution of the simulated temperature response mimics that observed only through about the first year. Thereafter, despite a significant aerosol optical depth perturbation in the tropical atmosphere, there is a lack of a signature in the temperature response that can be unambiguously attributed to the Pinatubo aerosols, suggesting other forced or unforced variations (e.g., ozone changes, quasi-biennial oscillation) occurring in the actual atmosphere which are unaccounted for in the model. In the high latitudes the large interannual variability prohibits a clear quantitative comparison between simulated and observed temperature changes and renders the aerosol-induced thermal signals statistically insignificant. In the global mean the evolution of the simulated lower stratospheric temperature response is in excellent agreement with the observation for the entire 2-year period, in contrast to the model-observation comparison at the low latitudes. This arises because in the global mean the stratospheric response is not sensitive to dynamical adjustments within the atmosphere caused by internal variations, and depends principally on the external radiative forcing caused by the aerosols. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, AOS Program, Princeton, NJ 08544 USA. Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. RP Ramachandran, S (reprint author), Phys Res Lab, Planetary Atmospher Sci Div, Ahmadabad 380009, Gujarat, India. EM ram@prl.ernet.in; vr@gfdl.gov; gera@envsci.rutgers.edu; robock@envsci.rutgers.edu RI Georgiy, Stenchikov/J-8569-2013; Robock, Alan/B-6385-2016; OI Robock, Alan/0000-0002-6319-5656 NR 76 TC 59 Z9 60 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2000 VL 105 IS D19 BP 24409 EP 24429 DI 10.1029/2000JD900355 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300017 ER PT J AU Jackson, C AF Jackson, C TI Sensitivity of stationary wave amplitude to regional changes in Laurentide ice sheet topography in single-layer models of the atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; FRESH-WATER INPUT; NORTH-ATLANTIC; BAROTROPIC ATMOSPHERE; THERMOHALINE CIRCULATION; HEINRICH EVENTS; YOUNGER DRYAS; OCEAN; PROPAGATION; OROGRAPHY AB Climate variability on millennial timescales has been observed in many geologic records covering the last glacial cycle. A potential source of this variability is the Laurentide ice sheet (LIS) in its periodic discharge of large quantities of icebergs to the North Atlantic. The present analysis considers whether regional variations in LIS topography could exert a significant influence on the atmosphere's stationary wave circulation. The maximum effect that regional changes in LIS topography have on the atmosphere's stationary wave circulation is determined using single-layer models of the atmosphere. Model experiments measure the individual contribution of 4.5 degrees x 7.5 degrees sections of the LIS and Greenland topography to global mean stationary wave amplitude. Results show the possibility for a limited region of topography to control a disproportionate amount of the atmosphere's total response to topography. Moreover, the possibility exists for a reduction in topographic forcing to increase stationary wave amplitude. These results can be understood by considering how the mean flow controls the horizontal propagation of wave energy and superposition of wave amplitude. The location of regions with enhanced stationary wave sensitivity to topographic alteration is found to be sensitive to mean topographic height but not mean wind strength. The latter is found to primarily affect the overall amplitude of sensitivity rather than the pattern. The impact of two hypothetical changes in LIS topography is considered, and they are found to have widely different effects on the global stationary wave field. Stationary wave sensitivity to topography within the single-layer models suggests that variations in the size or shape of the LIS can be one factor important to climate variability on millennial timescales. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08542 USA. RP Jackson, C (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Forrestal Campus,US Route 1, Princeton, NJ 08542 USA. EM csj@gfdl.gov RI Jackson, Charles/A-2202-2009 OI Jackson, Charles/0000-0002-2870-4494 NR 33 TC 10 Z9 10 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 OCT 16 PY 2000 VL 105 IS D19 BP 24443 EP 24454 DI 10.1029/2000JD900377 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 366WM UT WOS:000090029300019 ER PT J AU Barker, SLR Tarlov, MJ Canavan, H Hickman, JJ Locascio, LE AF Barker, SLR Tarlov, MJ Canavan, H Hickman, JJ Locascio, LE TI Plastic microfluidic devices modified with polyelectrolyte multilayers SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROPHORETIC SEPARATIONS; POLYMER LAYERS; CAPILLARIES; SURFACES; SYSTEMS; FILMS AB Control of the polymer surface chemistry is a crucial aspect of development of plastic microfluidic devices. When commercially available plastic substrates are used to fabricate microchannels, differences in the EOF mobility from plastic to plastic can be very high. Therefore, we have used polyelectrolyte multilayers (PEMs) to alter the surface of microchannels fabricated in plastics. Optimal modification of the microchannel surfaces was obtained by coating the channels with alternating layers of poly(allylamine hydrochloride) and poly(styrene sulfonate). Polystyrene (PS) and poly(ethylene terephthalate) glycol (PETG) were chosen las substrate materials because of the significant differences in the polymer chemistries and in the EOF of channels fabricated in these two plastic materials. The efficacy of the surface modification has been evaluated using XPS and by measuring the EOF mobility. When microchannels prepared in both PS and PETG are modified with PEMs, they demonstrate very similar electroosmotic mobilities. The PEMs are easily fabricated and provide a means for controlling the now direction and the electroosmotic mobility in the channels. The PEM-coated microchannels have excellent wettability, allowing facile filling of the channels. In addition, the PEMs produce reproducible results and are robust enough to withstand long-term storage. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. George Washington Univ, Washington, DC 20052 USA. RP Barker, SLR (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 23 TC 130 Z9 135 U1 0 U2 14 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 OCT 15 PY 2000 VL 72 IS 20 BP 4899 EP 4903 DI 10.1021/ac000548o PG 5 WC Chemistry, Analytical SC Chemistry GA 364ZW UT WOS:000089924800018 ER PT J AU Zeeb, DJ Nelson, BC Albert, K Dalluge, JJ AF Zeeb, DJ Nelson, BC Albert, K Dalluge, JJ TI Separation and identification of twelve catechins in tea using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID GREEN TEA; POLYPHENOLS; CANCER; FLAVAN-3-OLS; ANTIOXIDANTS; MECHANISMS; CAFFEINE; PLASMA; HEALTH; DIET AB A method has been developed for the direct microscale determination of 12 catethins in green and black tea infusions. The method is based on liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS). Standard catechin mixtures and tea infusions were analyzed by LC/APCI-MS with detection of protonated molecular ions and characteristic fragment ions for each compound, The identities of eight major catechins and caffeine in tea were established based on LC retention times and simultaneously recorded mass spectra. In addition, monitoring of the catechin-specific retro Diels-Alder fragment ion at m/z 139 throughout the chromatogram provided a unique fingerprint for catechin content in the samples that led to the identification of four minor chemically modified catechin derivatives in the infusions. This report is the first to describe the comprehensive determination of all 12 reported catechins in a single analysis. The utility of LC/APCI-MS for providing routine separation and identification of catechins at femtomole to low-picomole levels without extraction or sample pretreatment, and its potential as a standard analytical tool for the determination of polyphenols in natural products and biological fluids, are discussed. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ Tubingen, Inst Organ Chem, D-72076 Tubingen, Germany. RP Dalluge, JJ (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, 100 Bur Dr,Stop 8392, Gaithersburg, MD 20899 USA. NR 30 TC 95 Z9 97 U1 3 U2 22 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 OCT 15 PY 2000 VL 72 IS 20 BP 5020 EP 5026 DI 10.1021/ac000418f PG 7 WC Chemistry, Analytical SC Chemistry GA 364ZW UT WOS:000089924800036 PM 11055724 ER PT J AU Marti, GE Gaigalas, A Vogt, RF AF Marti, GE Gaigalas, A Vogt, RF TI Recent developments in quantitative fluorescence calibration for analyzing cells and microarrays SO CYTOMETRY LA English DT Editorial Material ID CYTOMETRY C1 US FDA, Ctr Biol Evaluat & Res, Off Therapeut Res & Review, Div Cell & Gene Therapy, Bethesda, MD USA. NIST, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. Ctr Dis Control & Prevent, Natl Diabet Lab, Atlanta, GA USA. RP Vogt, RF (reprint author), CDC, Mailstop F19, Atlanta, GA 30341 USA. NR 9 TC 9 Z9 10 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-4763 J9 CYTOMETRY JI Cytometry PD OCT 15 PY 2000 VL 42 IS 5 BP 263 EP 263 DI 10.1002/1097-0320(20001015)42:5<263::AID-CYTO1>3.0.CO;2-Q PG 1 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 366DG UT WOS:000089989100001 PM 11025482 ER PT J AU Lee, SH Kajii, Y Akimoto, H AF Lee, SH Kajii, Y Akimoto, H TI Improvement of the new NO detection method using laser-induced two-photon ionization with a TOF mass spectrometer SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID OZONE PRODUCTION; DISTRIBUTIONS; TROPOSPHERE; INSTRUMENT; JAPAN AB We have developed a new method to detect low concentrations of tropospheric NO, using laser induced two-photon ionization (Lee, S.-H.; Hirokawa, J.; Yoshizumi, Y.; Akimoto, H. Rev. Sci. Instrum. 1997, 68,2891). This method uses a frequency-doubled pulsed-dye laser operating near 226 nm to photoionize MO by resonance enhanced two-photon ionization via its A(2)X(2) (0,0) band. This work reports our recent results regarding the improvement of the overall instrumental performance obtained by applying a time-of-flight (TOF) mass spectrometer and further discusses the water vapor influence in this method. NO ion signals were discriminated efficiently from the other ions generated by impurities in the ionization cell by using a TOF mass spectrometer. The obtained sensitivity of this method was 10 pptv (S/N = 2), at a laser power of 44 muJ and an integration time of 1 min. Also, the background signal was decreased from 5 to 0.25 Hz as compared to the previous study, indicating that a nearly signal-limited condition was obtained, which enables NO detection free from background noise. In our laser ionization instrument, the uncertainty in NO ion intensity caused by the fluctuation of laser power was deviated less than 3% from a long-term average. Moreover, by comparison with the ozone-chemiluminescence method, water vapor influence has been investigated by introducing humid sampling gases into the molecular beam. As the relative humidity in the sampling gases varied from 0 to 85% at room temperature, no significant change in the NO detection efficiency was observed. This demonstrates an important advantage over the ozone-chemiluminescence method, although further field intercomparisons are required to certify the applicability of this new NO ionization method into the atmospheric study. C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo 153, Japan. RP Lee, SH (reprint author), NOAA, Aeron Lab, R AL7, Boulder, CO 80303 USA. RI Lee, Shan-Hu/F-9913-2014 NR 25 TC 6 Z9 6 U1 0 U2 3 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 15 PY 2000 VL 34 IS 20 BP 4434 EP 4438 DI 10.1021/es990879m PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 365UZ UT WOS:000089970000028 ER PT J AU Pfeilsticker, K Sturges, WT Bosch, H Camy-Peyret, C Chipperfield, MP Engel, A Fitzenberger, R Muller, M Payan, S Sinnhuber, BM AF Pfeilsticker, K Sturges, WT Bosch, H Camy-Peyret, C Chipperfield, MP Engel, A Fitzenberger, R Muller, M Payan, S Sinnhuber, BM TI Lower stratospheric organic and inorganic bromine budget for the Arctic winter 1998/99 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DIFFERENT LATITUDES; PROFILES; ATMOSPHERE; SEASONS AB In the Arctic winter 1998/99, two balloon payloads were launched in a co-ordinated study of stratospheric bromine. Vertical profiles (9-28 km) of all known major organic Br species (CH3Br, C2H5Br, CH2BrCl, CHBrCl2, CH2Br2, CHBr2Cl, CHBr3, H1301, H1211, H2402, and H1202) were measured, and total organic Br (henceforth called Br-y(org)) originating from these organic precursors was inferred as a function of altitude. This was compared with total inorganic reactive Br (henceforth called Br-y(in)) derived from spectroscopic BrO observations, after accounting for modeled stratospheric Br-y partitioning. Within the studied altitude range the two profiles differed by less than the estimated accumulated uncertainties. This good agreement suggests that the lower stratospheric budget and chemistry of Br is well understood for the specified conditions. For early 1999 our data suggest a Br-y(in) mixing ratio of 1.5 ppt in air just above the local Arctic tropopause (similar to 9.5 km), whilst at 25 km in air of 5.6 yr mean age it was estimated to be 18.4(+1.8/-1.5) ppt from organic pr cursor measurements, and (21.5+/-3.0) ppt from BrO measurements and photochemical modelling, respectively. This suggests a Br-y(in) influx of 3.1(-2.9/+3.5) ppt from the troposphere to the stratosphere. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. Univ Paris 06, CNRS, LPMA, Paris, France. Univ Leeds, Sch Environm, Leeds, W Yorkshire, England. Univ E Anglia, Sch Environm Sci, Norwich NR4 7TJ, Norfolk, England. Univ Frankfurt, Inst Meteorol & Geophys, D-6000 Frankfurt, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Pfeilsticker, K (reprint author), Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany. RI Sinnhuber, Bjorn-Martin/A-7007-2013; Chipperfield, Martyn/H-6359-2013; Boesch, Hartmut/G-6021-2012; Engel, Andreas/E-3100-2014 OI Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Chipperfield, Martyn/0000-0002-6803-4149; Engel, Andreas/0000-0003-0557-3935 NR 25 TC 69 Z9 70 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 15 PY 2000 VL 27 IS 20 BP 3305 EP 3308 DI 10.1029/2000GL011650 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 365RR UT WOS:000089964700019 ER PT J AU Thompson, AM Doddridge, BG Witte, JC Hudson, RD Luke, WT Johnston, JE Johnston, BJ Oltmans, SJ Weller, R AF Thompson, AM Doddridge, BG Witte, JC Hudson, RD Luke, WT Johnston, JE Johnston, BJ Oltmans, SJ Weller, R TI A tropical Atlantic paradox: Shipboard and satellite views of a tropospheric ozone maximum and wave-one in January-February 1999. SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODIFIED-RESIDUAL METHOD AB During the Aerosols99 trans-Atlantic cruise from Norfolk, VA, to Cape Town, South Africa, daily ozonesondes were launched from the R/V Ronald H Brown between 17 January and 6 February 1999. A composite of tropospheric ozone profiles along the latitudinal transect shows 4 zones, nearly identical to the ozone distribution during a January-February 1993 trans-Atlantic cruise [Weller et al., 1996]. Sondes from the cruise and Ascension Island (8S, 14.5W), as well as the Earth-Probe (EP)/TOMS satellite instrument, show elevated tropospheric ozone (> 35 Dobson Units) throughout the south Atlantic in January 1999. Ozone layers associated with biomass burning north of the ITCZ (Intertropical Convergence Zone) are prominent at 0-5 km from 10-0N, but even higher ozone (100 ppbv, 5-15 km) occurred south of the ITCZ, where it was not burning - an ozone "paradox" that contributes to a wave-one zonal pattern in tropospheric ozone. Back trajectories, satellite observations and shipboard tracers suggest that the south Atlantic ozone results from a combination of interhemispheric transport, aged stratospheric-upper tropospheric air, and possibly from ozone supplied by lightning nitric oxide. C1 NASA, Goddard Space Flight Ctr, EITI, Greenbelt, MD 20771 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Univ Washington, NOAA, PMEL, JISAO, Seattle, WA 98115 USA. NOAA, Air Resources Lab, SSMC, Silver Spring, MD 20910 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. RP Thompson, AM (reprint author), NASA, Goddard Space Flight Ctr, EITI, Code 916, Greenbelt, MD 20771 USA. RI Hudson, Robert/F-4506-2010; Luke, Winston/D-1594-2016; Thompson, Anne /C-3649-2014 OI Luke, Winston/0000-0002-1993-2241; Thompson, Anne /0000-0002-7829-0920 NR 14 TC 92 Z9 92 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 2000 VL 27 IS 20 BP 3317 EP 3320 DI 10.1029/1999GL011273 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 365RR UT WOS:000089964700022 ER PT J AU O'Neill, NT Ignatov, A Holben, BN Eck, TF AF O'Neill, NT Ignatov, A Holben, BN Eck, TF TI The lognormal distribution as a reference for reporting aerosol optical depth statistics; Empirical tests using multi-year, multi-site AERONET sunphotometer data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Aerosol optical depth data representative of various types of aerosols was employed to empirically demonstrate that the lognormal probability distribution is a better reference for reporting optical depth statistics than a normal probability distribution. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, NESDIS, Climate Res & Applicat Div, Camp Springs, MD USA. Univ Sherbrooke, CARTEL, LOA, Sherbrooke, PQ J1K 2R1, Canada. RP O'Neill, NT (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Ignatov, Alexander/F-5594-2010; ECK, THOMAS/D-7407-2012 OI Ignatov, Alexander/0000-0002-7463-5944; NR 9 TC 89 Z9 93 U1 1 U2 6 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 15 PY 2000 VL 27 IS 20 BP 3333 EP 3336 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 365RR UT WOS:000089964700026 ER PT J AU Misakian, M Benck, E Wang, YC AF Misakian, M Benck, E Wang, YC TI Time evolution of ion energy distributions and optical emission in pulsed inductively coupled radio frequency plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-IMPACT IONIZATION; CYCLOTRON-RESONANCE PLASMA; H-MODE TRANSITION; CROSS-SECTIONS; REFERENCE CELL; ARGON; DISCHARGES; OXYGEN AB This article reports the results of time-resolved measurements of ion energy distributions (IEDs), relative ion densities, as well as optical emissions and electrical characteristics in pulsed inductively coupled plasmas for the simple gas mixture of oxygen and argon (50%Ar:50%O-2). The peak radio frequency power, frequency, repetition rate, and duty cycle were 200 W, 13.56 MHz, 500 Hz, and 85%, respectively. Examination of the time evolution of the data over the pulse cycle indicates that when the plasma is energized, it begins in the dim (E) mode undergoing at first slow changes in certain plasma parameters. After about 1.2 ms, a sudden transition to the bright (H) mode occurs. The characteristics of the IEDs are consistent with an average plasma potential profile that has (a) a relatively large collisionless sheath and narrow presheath during the dim mode and (b) a very narrow sheath and greatly extended presheath during the bright mode; the ion mean free path influences the peak position of the IED during the bright mode. For most of the pulse cycle, the relative abundances of the ions Ar+, O-2(+), and O+ maintain the relation %O(2)(+)greater than or equal to%Ar+>%O+. [S0021-8979(00)01621-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Misakian, M (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 25 TC 2 Z9 2 U1 0 U2 5 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 OCT 15 PY 2000 VL 88 IS 8 BP 4510 EP 4517 DI 10.1063/1.1311827 PG 8 WC Physics, Applied SC Physics GA 358HP UT WOS:000089552800007 ER PT J AU Michaels, CA Stranick, SJ Richter, LJ Cavanagh, RR AF Michaels, CA Stranick, SJ Richter, LJ Cavanagh, RR TI Scanning near-field infrared microscopy and spectroscopy with a broadband laser source SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FREE-ELECTRON LASER; OPTICAL MICROSCOPY; RAMAN-SPECTROSCOPY; SUBWAVELENGTH RESOLUTION; FIBER PROBES; MODE; FABRICATION; ARTIFACTS; SILICON; STRESS AB A scanning near-field microscope that allows the fast acquisition of midinfrared absorption spectra is described. The microscope couples the nanoscale spatial resolution of a scanning probe microscope with the chemical specificity of vibrational spectroscopy. Key design elements of the microscope include a tunable broadband infrared light source; an infrared focal plane array-based spectrometer which allows parallel detection of the entire pulse bandwidth (200 cm(-1)); and a single mode, fluoride glass, near-field probe fabricated with a chemical etching protocol. Infrared transmission images of a micropatterned thin gold film are presented that demonstrate spatial resolution conservatively estimated to be lambda/7.5 at 3.4 mu m, in the absence of optical artifacts due to topography. Constant height mode images of a polymer nanocomposite demonstrate instrumental sensitivity to fractional transmission changes of 1x10(-3). Near-field absorption spectra (lambda=3.4 mu m) of a 2 mu m thick polystyrene film are presented which demonstrate the instrumental sensitivity required for high spatial resolution, near-field absorption imaging. These spectra are acquired in 2 s and indicate a film thickness detection limit for polystyrene of 200 nm. Measurements exploring the coupling between the infrared absorption magnitude and changes in tip-sample separation suggest that near-field absorption imaging is relatively insensitive to topographic artifacts. [S0021-8979(00)07420-X]. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Michaels, CA (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 51 TC 39 Z9 39 U1 1 U2 10 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 OCT 15 PY 2000 VL 88 IS 8 BP 4832 EP 4839 DI 10.1063/1.1309034 PG 8 WC Physics, Applied SC Physics GA 358HP UT WOS:000089552800060 ER PT J AU Sun, DZ AF Sun, DZ TI The heat sources and sinks of the 1986-87 El Nino SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN OSCILLATION; INTERANNUAL VARIABILITY; EQUATORIAL PACIFIC; TROPICAL PACIFIC; OCEAN; ATMOSPHERE; MODEL; ENSO; CLIMATE AB The heat balance of the coupled tropical ocean-atmosphere system during the Earth Radiation Budget Experiment (ERBE) period (1985-89) is analyzed in an attempt to better understand the heat sources and sinks of the 1986-87 El Nino. The analysis involves the use of radiation data from ERBE, circulation statistics from National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis, and the assimilated data for the Pacific ocean. Accumulation of heat in the equatorial upper ocean is found prior to the onset of the 1986-87 El Nino. The accumulated heat in the equatorial upper ocean comes from the surface heating, which exceeds the poleward transport of heat in the upper ocean. The accumulated heat in the upper ocean resurfaces in the eastern Pacific and the 1986-87 El Nino warming develops. The warming results in a substantial increase in the equator-to-pole heat transport in the equatorial ocean. The ocean warming is also accompanied by a significant increase in the poleward transport of energy in the atmosphere and a significant reduction in the surface heat Aux into the equatorial ocean, though these changes are smaller than the increases in the poleward heat transport in the ocean. Because of the feedbacks from water vapor and clouds, the variations in the net radiative energy flux at the top of the atmosphere are small and the surface heat flux into the equatorial ocean is mainly modulated by the poleward transport of energy in the atmosphere, which is in turn modulated by the intensity of the cold tongue. The anomalous poleward ocean heat transport does not stop right at the time when the surface warming is terminated, and this "overshooting" pushes the equatorial ocean to a cold state-the 1988-89 La Nina-during which the poleward transport in the atmosphere and ocean is reduced and heat starts to accumulate in the upper ocean again. The coupled system is then in a situation similar to 1985 and is preparing for the onset of another El Nino. The results suggest that ENSO system behaves like a heat pump: the equatorial ocean absorbs heat during the cold phase and pushes the heat to the subtropical ocean during the warm phase. This picture for El Nino implies that the surface heat flux into the equatorial ocean may be a driving force of El Nino. The relationship between this picture for El Nino and the delayed oscillator hypothesis is explored. An explanation for the absence of El Nino in the tropical Atlantic ocean is offered by noting that the zonal width of the basin limits the amount of heat that can be accumulated in the upper ocean. The implication of the present findings for the response of El Nino to global warming is discussed. C1 NOAA, CIRES, Climate Diagnost Ctr RCDCI, Boulder, CO 80303 USA. RP Sun, DZ (reprint author), NOAA, CIRES, Climate Diagnost Ctr RCDCI, 325 Broadway, Boulder, CO 80303 USA. NR 34 TC 21 Z9 22 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT 15 PY 2000 VL 13 IS 20 BP 3533 EP 3550 DI 10.1175/1520-0442(2000)013<3533:THSASO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600001 ER PT J AU Meinen, CS McPhaden, MJ AF Meinen, CS McPhaden, MJ TI Observations of warm water volume changes in the equatorial Pacific and their relationship to El Nino and La Nina SO JOURNAL OF CLIMATE LA English DT Article ID HEAT-CONTENT VARIABILITY; OCEAN RECHARGE PARADIGM; TROPICAL PACIFIC; SOUTHERN OSCILLATION; TEMPERATURE ANALYSES; CONCEPTUAL-MODEL; WAVE DYNAMICS; ENSO; INTERPOLATION; SYSTEM AB This paper describes observed changes in surface winds, sea surface temperature (SST), and the volume of water warmer than 20 degreesC (WWV) in the equatorial Pacific Ocean for the period 1980-99. The purpose is to test recent, hypotheses about the relationship between variations in WWV and the Fl Nino-Southern Oscillation (ENSO) cycle. The results confirm inferences based on theory, models, and previous empirical analyses using proxy data (namely sea level) that ENSO involves a recharge and discharge of WWV along the equator and that the cyclic nature of ENSO results from a disequilibrium between zonal winds and zonal mean thermocline depth. The authors also find that the magnitude of ENSO SST anomalies is directly related to the magnitude of zonal mean WWV anomalies. Furthermore, for a given change in equatorial WWV, the corresponding warm Fl Nino SST anomalies are larger than the corresponding cold La Nino anomalies. This asymmetry between the warm and cold phases of the ENSO cycle implies differences in the relative importance of physical processes controlling SST during El Nino and La Nino events. C1 NOAA, Pacific Marine Environm Lab, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Meinen, CS (reprint author), NOAA, Pacific Marine Environm Lab, Joint Inst Study Atmosphere & Oceans, 7600 Sand Point Way NE,OCRD Bldg 3, Seattle, WA 98115 USA. RI Meinen, Christopher/G-1902-2012; McPhaden, Michael/D-9799-2016 OI Meinen, Christopher/0000-0002-8846-6002; NR 41 TC 252 Z9 256 U1 2 U2 18 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT 15 PY 2000 VL 13 IS 20 BP 3551 EP 3559 DI 10.1175/1520-0442(2000)013<3551:OOWWVC>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600002 ER PT J AU Kessler, WS Kleeman, R AF Kessler, WS Kleeman, R TI Rectification of the Madden-Julian oscillation into the ENSO cycle SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; OCEAN-ATMOSPHERE MODEL; TROPICAL PACIFIC-OCEAN; INTRASEASONAL OSCILLATIONS; EQUATORIAL OCEAN; OPTIMAL-GROWTH; EL-NINO; CONVECTION; VARIABILITY; ANOMALIES AB An ocean general circulation model, forced with idealized, purely oscillating wind stresses over the western equatorial Pacific similar to those observed during the Madden-Julian oscillation (MJO), developed rectified low-frequency anomalies in SST and zonal currents, compared to a run in which the forcing was climatological. The rectification in SST resulted from increased evaporation under stronger than normal winds of either sign, from correlated intraseasonal oscillations in both vertical temperature gradient and upwelling speed forced by the winds, and from zonal advection due to nonlinearly generated equatorial currents. The net rectified signature produced by the MJO-like wind stresses was SST cooling (about 0.4 degreesC) in the west Pacific, and warming (about 0.1 degreesC) in the central Pacific, tending to flatten the background zonal SST gradient. It is hypothesized that, in a coupled system, such a pattern of SST anomalies would spawn additional westerly wind anomalies as a result of SST-induced changes in the low-level zonal pressure gradient. This was tested in an intermediate coupled model initialized to 1 January 1997, preceding the 1997-98 Fl Nino. On its own, the model hindcast a relatively weak warm event, but when the effect of the rectified SST pattern was imposed, a coupled response produced the hypothesized additional westerlies and the hindcast El Nino became about 50% stronger (measured by east Pacific SST anomalies), suggesting that the MJO can interact constructively with the ENSO cycle. This implies that developing the capacity to predict, if not individual MJO events, then the conditions that affect their amplitude, may enhance predictability of the strength of oncoming El Ninos. C1 NOAA, Pacific Marine Environm Lab, OC, Seattle, WA 98115 USA. Bur Meteorol Res Ctr, Melbourne, Vic, Australia. RP Kessler, WS (reprint author), NOAA, Pacific Marine Environm Lab, OC, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 61 TC 200 Z9 212 U1 3 U2 20 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 15 PY 2000 VL 13 IS 20 BP 3560 EP 3575 DI 10.1175/1520-0442(2000)013<3560:ROTMJO>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600003 ER PT J AU Mo, KC Paegle, JN AF Mo, KC Paegle, JN TI Influence of sea surface temperature anomalies on the precipitation regimes over the Southwest United States SO JOURNAL OF CLIMATE LA English DT Article ID INTERANNUAL VARIABILITY; SUMMER RAINFALL; PACIFIC; TELECONNECTIONS AB Precursory signals in sea surface temperature anomalies (SSTAs) associated with summer precipitation over the Southwest (SW) United States are examined using data from 1900 to 1996. Two patterns of SSTAs are found to influence summer and winter precipitation evolution. One pattern shows positive anomalies extending from the central Pacific to the west coast of the Americas during winter. Warm SSTAs over the equatorial central Pacific in winter are associated with wet conditions in the SW and dry conditions over the Pacific Northwest. The following summer, SSTAs in the central Pacific diminish, but positive SSTAs remain over the tropical eastern Pacific and in the vicinity of Central America. Warm SSTs are conducive to enhanced rising motion and convection. A compensating downward branch is found over the SW favoring dry conditions over that area. Negative SSTAs have the opposite effect. This mode is similar to the SSTA pattern discussed by Higgins et al. When this mode is active, a wet (dry) SW winter is followed by a dry (wet) summer. In addition to SSTAs over the central and eastern Pacific, another controlling factor is the SSTA over the North Pacific. Negative (positive) SSTAs over the North Pacific persist from winter to summer and favor positive (negative) rainfall anomalies over the SW. When this mode is active, a wet (dry) SW persists from winter to summer. The authors conclude that SW rainfall evolution from winter to the following summer is modulated by both SSTAs over the equatorial Pacific arid over the North Pacific. SSTAs in the equatorial Pacific alone are not sufficient to explain the observed summer rainfall variability over the southwest United States. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. RP Mo, KC (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 20 TC 27 Z9 27 U1 2 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 15 PY 2000 VL 13 IS 20 BP 3588 EP 3598 DI 10.1175/1520-0442(2000)013<3588:IOSSTA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600005 ER PT J AU Mo, KC AF Mo, KC TI Relationships between low-frequency variability in the Southern Hemisphere and sea surface temperature anomalies SO JOURNAL OF CLIMATE LA English DT Article ID INTERDECADAL VARIABILITY; CLIMATE SYSTEM; INDIAN-OCEAN; ANNUAL CYCLE; CIRCULATION; ATMOSPHERE; MODES; ENSO AB Long-term trends and interannual variations of circulation anomalies in the Southern Hemisphere are examined using the National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis from 1949 to 1998. The changes in planetary circulation regimes are linked to global sea surface temperature anomalies (SSTAs). Empirical orthogonal function (EOF) analysis was performed on 500-hPa height anomalies. The leading mode EOF1 shows a strong zonal symmetry with a phase reversal between height anomalies in high and midlatitudes. Apart from zonal symmetry, a zonal wavenumber 3 is evident with three centers located in three southern oceans. In the low-frequency band with fluctuations longer than 60 months, EOF1 is associated with the second rotated EOF mode of SSTAs with positive loadings over three southern oceans and negative loadings in the North Pacific and the North Atlantic. The next two modes are the Pacific-South American (PSA) patterns. They depict wave-3 patterns in quadrature with each other and a well-defined wave train from the tropical Pacific to Argentina with large amplitudes in the Pacific-South American sector. On decadal timescales, the abrupt warming over the central and eastern Pacific is related to the strengthening of PSA1. In the interannual band, PSA1 is associated with the low-frequency part of El Nino-Southern Oscillation (ENSO) variability with the dominant period of 40-48 months. PSA2 is associated with the quasi-biennial component of ENSO variability with a period of 26 months. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. RP Mo, KC (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 32 TC 188 Z9 204 U1 2 U2 13 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 15 PY 2000 VL 13 IS 20 BP 3599 EP 3610 DI 10.1175/1520-0442(2000)013<3599:RBLFVI>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600006 ER PT J AU Peng, PT Kumar, A Barnston, AG Goddard, L AF Peng, PT Kumar, A Barnston, AG Goddard, L TI Simulation skills of the SST-forced global climate variability of the NCEP-MRF9 and the Scripps-MPI ECHAM3 models SO JOURNAL OF CLIMATE LA English DT Article ID LOW-FREQUENCY VARIABILITY; SEA-SURFACE TEMPERATURE; EMPIRICAL ORTHOGONAL FUNCTIONS; GENERAL-CIRCULATION MODEL; OCEAN-ATMOSPHERE MODEL; SOUTHERN OSCILLATION; INTERANNUAL VARIABILITY; NORTHERN-HEMISPHERE; EQUATORIAL PACIFIC; EL-NINO AB The global responses of two atmospheric general circulation models (AGCM), the National Centers for Environmental Prediction-Medium Range Forecast (NCEP-MRF9) and the University of Hamburg climate model-3 (ECHAM), to simultaneous global SST forcing are examined on a 3-month timescale. Rotated principal components analysis of the model and observations is also used to identify and compare their leading modes of coherent variability. The scope of the present analyses is largely descriptive and does not attempt to explain the differences in model behavior in terms of their formulations. The authors' main focus is to quantify the simulation skill of the two comprehensive AGCMs on seasonal timescales and compare it to skill obtained using empirical prediction models. Both models are found to exhibit realistic responses to Fl Nino-Southern Oscillation (ENSO)-related forcing, with the ECHAM response slightly more accurate in the spatial phasing and structure of the atmospheric anomalies. The ECHAM model exhibits realistic atmospheric responses to tropical Pacific SST forcing as well as patterns associated with extratropical internal atmospheric dynamics [e.g., North Atlantic oscillation (NAO) and a high latitude north-south dipole in the Pacific]. It shows a slightly higher signal-to-noise ratio than that found in the real world, while the NCEP model's signal-to-noise ratio is approximately equal to that in nature. The NCEP model responds with more zonally symmetric atmospheric patterns than observed, although this does not prevent it from forming realistic responses to ENSO over the Pacific-North American region. The NCEP model's NAO variability is only about half as strong as that observed. In terms of simulation skill with respect to observations, the ECHAM model generally tends to outperform the NCEP model for global 500-hPa geopotential height and surface climate. A decomposition of the observed and model data into rotated principal components indicates that both models reproduce the ENSO-related anomalies in circulation and surface climate of the real atmosphere quite well. The ECHAM model, which handles ENSO variability and impacts slightly better than the NCEP model, shows a larger increment of capability in reproducing other global climate processes. Two linear statistical benchmarks, which are used as skill control measures, sometimes outperform the NCEP model but are more comparable, on average, to the skill of the ECHAM model. Thus as noted in other recent studies, the dynamical models and the statistical models have roughly the same simulation skill and would be expected to have similar forecast skill if the models used forecasted SSTs as their boundary conditions. To first order, the linear component of the relationships appears to be modeled well by the two dynamical models. It is undetermined whether instances of better performance of the dynamical models than the statistical benchmarks are partly attributable to the models' effective exploitation of nonlinearities in the relationships between tropical SST and global climate. One reason for this inconclusiveness is that evidence for nonlinearities in the present analyses is nor compelling. Hence, the question of whether dynamical models have untapped potential to consistently outperform statistical models on the seasonal timescale remains open and may require close examination of each physical formulation in the dynamical models. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Washington, DC 20233 USA. NOAA, Climate Modeling Branch, EMC, NCEP,NWS, Washington, DC USA. Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, La Jolla, CA 92093 USA. RP Peng, PT (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, W-NP51,5200 Auth Rd,Room 604, Washington, DC 20233 USA. NR 47 TC 54 Z9 54 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 OCT 15 PY 2000 VL 13 IS 20 BP 3657 EP 3679 DI 10.1175/1520-0442(2000)013<3657:SSOTSF>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369JR UT WOS:000165062600010 ER PT J AU Gu, W Xu, Q AF Gu, W Xu, Q TI Baroclinic Eady wave and fronts. Part III: Unbalanced dynamics - Departures from viscous semigeostrophy SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PLANETARY BOUNDARY-LAYER; NONLINEAR EQUILIBRATION; POTENTIAL VORTICITY; FRONTOGENESIS; COLLAPSE; MODEL; RAINBANDS; EQUATIONS AB By subtracting the viscous semigeostrophic (SG) equations from the primitive equations, a set of nonlinear perturbation equations is derived and used to study the unbalanced perturbations generated during the process of Eady wave frontogenesis and quantify the errors in the viscous SG solutions with two types (free slip and nonslip) of boundary conditions. This set of equations shows that the unbalanced perturbation is generated by a Vector forcing, called the SG forcing, whose components are defined by the SG Lagrangian time derivatives of three ageostrophic components in the cross-frontal wind, along-frontal wind and buoyancy fields, respectively. It is found that the unbalanced perturbations are generated almost totally by the wind-forcing components and the buoyancy forcing is always negligibly small. In the free-slip case, the along-frontal wind forcing is weaker than the cross-frontal one and the unbalanced perturbations are generated largely as a linear response in the form of inertial gravity waves to die forcing. In the nonslip case, the along-frontal wind-forcing component is slightly stronger than the cross-frontal forcing, but the unbalanced perturbations are generated in the form of enhanced planetary boundary layer pumping immediately ahead of the front and in the form of inertial gravity waves in the warm sector farther away from the front. In both cases, the unbalanced perturbations are much weaker than their balanced counterparts even when the fronts are fully developed. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Xu, Q (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 21 TC 3 Z9 3 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 OCT 15 PY 2000 VL 57 IS 20 BP 3414 EP 3425 DI 10.1175/1520-0469(2000)057<3414:BEWAFP>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 369FC UT WOS:000165054500006 ER PT J AU Hudson, LT Tolk, NH Bao, C Nordlander, P Russell, DP Xu, J AF Hudson, LT Tolk, NH Bao, C Nordlander, P Russell, DP Xu, J TI Electron- and photon-stimulated desorption of atomic hydrogen from radiation-modified alkali halide surfaces SO PHYSICAL REVIEW B LA English DT Article ID TRANSLATIONAL ENERGY-DISTRIBUTION; ADSORPTION; IMPACT; H+; MECHANISMS; IONS; CHEMISORPTION; SPECTROSCOPY; DISSOCIATION; EXCITATION AB The desorption yields of excited hydrogen atoms from the surfaces of KCl, KBr, NaCl, NaF, and LiF have been measured as a function of incident photon and electron energy and flux, time of irradiation, dosing pressure of H-2 and sample temperature. As these surfaces are exposed to Il, gas during electron or photon bombardment, the fluorescence from excited hydrogen atoms ejected from the surface is monitored. The desorption yields are found to be contingent upon surface damage induced by the incident particle radiation, leading to dissociative adsorption at surface sites containing an excess of alkali metal. A desorption mechanism is presented in which incident electrons or photons induce a valence excitation to a neutral, antibonding state of the surface alkali hydride molecule complex, leading to the desorption of hydrogen atoms possessing several eV of kinetic energy. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Rice Univ, Dept Phys, Houston, TX 77251 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Nordlander, Peter/A-2560-2008 OI Nordlander, Peter/0000-0002-1633-2937 NR 54 TC 7 Z9 7 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2000 VL 62 IS 15 BP 10535 EP 10543 DI 10.1103/PhysRevB.62.10535 PG 9 WC Physics, Condensed Matter SC Physics GA 365YB UT WOS:000089977100102 ER PT J AU Hutchinson, DAW Burnett, K Dodd, RJ Morgan, SA Rusch, M Zaremba, E Proukakis, NP Edwards, M Clark, CW AF Hutchinson, DAW Burnett, K Dodd, RJ Morgan, SA Rusch, M Zaremba, E Proukakis, NP Edwards, M Clark, CW TI Gapless mean-field theory of Bose-Einstein condensates SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID COLLECTIVE EXCITATIONS; FINITE TEMPERATURES; GAS; DYNAMICS AB We present a topical review of the development of finite-temperature field theories of Bose-Einstein condensation in weakly interacting atomic gases. We highlight the difficulties in obtaining a consistent finite-temperature theory that has a gapless excitation spectrum in accordance with Goldstone's theorem and which is free from both ultraviolet and infrared divergences. We present results from the two consistent theories developed so far. These are the Hartree-Fock-Bogoliubov theory within the Popov approximation and a many-body T-matrix approach which we have termed gapless-Hartree-Fock-Bogoliubov (GHFB). Comparison with the available experimental results is made and the remaining difficulties are highlighted. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. Inst Elect Struct & Laser, Fdn Res & Technol Hellas, Heraklion 71110, Crete, Greece. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Hutchinson, DAW (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 32 TC 70 Z9 70 U1 0 U2 2 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 OCT 14 PY 2000 VL 33 IS 19 BP 3825 EP 3846 DI 10.1088/0953-4075/33/19/302 PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 367ZB UT WOS:000090091600003 ER PT J AU Bruun, GM Clark, CW AF Bruun, GM Clark, CW TI Detection of the BCS transition in a trapped Fermi gas SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID SUPERFLUID STATE; LI-6 AB We investigate theoretically the quasiparticle properties of a trapped gas of fermionic atoms in both the normal and the superfluid phases. Our analysis, which accounts for the shell structure of the normal phase spectrum, shows that the single-particle response of the gas to a modulation of the trapping frequency should indicate the onset of superfluidity. The results are discussed in the context of current experiments on trapped Fermi gases. C1 US Dept Commerce, Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Bruun, GM (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 17 TC 19 Z9 19 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD OCT 14 PY 2000 VL 33 IS 19 BP 3953 EP 3959 DI 10.1088/0953-4075/33/19/310 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 367ZB UT WOS:000090091600011 ER PT J AU Wood, BE Ambruster, CW Brown, A Linsky, JL AF Wood, BE Ambruster, CW Brown, A Linsky, JL TI The MgII and Ly alpha lines of nearby K dwarfs: Interstellar medium components and flux measurements SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : atoms; stars : chromospheres; stars : late-type; ultraviolet : ISM; ultraviolet : stars ID HIGH-RESOLUTION SPECTROGRAPH; CHROMOSPHERICALLY ACTIVE STARS; EPSILON-CANIS-MAJORIS; LOCAL CLOUD; D/H RATIO; GAS; PHOTOMETRY; DEUTERIUM; SIGHT; ABUNDANCES AB We analyze local interstellar medium (LISM) absorption observed in the Ly alpha and Mg II h and k lines of six nearby K dwarf stars, using UV spectra of these stars obtained with the Goddard High Resolution Spectrograph on the Hubble Space Telescope. For four of the six stars, we detect an absorption component with a velocity and column density consistent with the Local Interstellar Cloud (LIC). For HD 197890, there is no observed component at the expected LIC velocity or at the projected velocity of the G cloud, which is a nearby cloud in the general direction of the Galactic center. It also seems doubtful that either of the two components seen toward HD 82558 are LIC or G cloud absorption. The total H I column density toward HD 82558 (d = 18.3 pc) is extremely high (log N-H = 19.05 +/- 0.15), representing the largest average H I density detected for any line of sight through the nearby LISM (n(H) approximate to 0.2 cm(-3)). This is particularly remarkable considering that this star is only 39 degrees from the "interstellar tunnel" toward is an element of CMa, where column densities are an order of magnitude lower than this toward stars that are an order of magnitude farther away. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. RP Wood, BE (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 49 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 411 EP 420 DI 10.1086/309540 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400040 ER PT J AU Wood, BE Muller, HR Zank, GP AF Wood, BE Muller, HR Zank, GP TI Hydrogen Ly alpha absorption predictions by Boltzmann models of the heliosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; shock waves; solar wind; ultraviolet : ISM ID LOCAL INTERSTELLAR-MEDIUM; SOLAR-WIND INTERACTION; HST-GHRS OBSERVATIONS; COSMIC-RAYS; D/H RATIO; SIRIUS-A; HELIOPAUSE; CENTAURI; SIGHT; LINE AB We use self-consistent kinetic/hydrodynamic models of the heliosphere to predict H I Ly alpha absorption profiles for various lines of sight through the heliosphere. These results are compared with Ly alpha absorption lines of six nearby stars observed by the Hubble Space Telescope. The directions of these lines of sight range from nearly upwind (36 Oph) to nearly downwind (is an element of Eri). Only three of the Ly alpha spectra (36 Oph, alpha Cen, and Sirius) actually show evidence for the presence of heliospheric absorption, which is blended with the ubiquitous interstellar absorption, but the other three spectra still provide useful upper limits for the amount of heliospheric absorption for those lines of sight. Most of our models use a Boltzmann particle code for the neutrals, allowing us to estimate neutral velocity distributions throughout the heliosphere, from which we compute model Ly alpha absorption profiles. In comparing these models with the data, we find they predict too much absorption in sidewind and downwind directions, especially when higher Mach numbers are assumed for the interstellar wind. Models created assuming different values of the interstellar temperature and proton density fail to improve the agreement. Somewhat surprisingly, a model that uses a multifluid treatment of the neutrals rather than the Boltzmann particle code is more consistent with the data, and we speculate as to why this may be the case. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Wood, BE (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 35 TC 37 Z9 38 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 493 EP 503 DI 10.1086/309541 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400048 ER PT J AU Wohl, EE Pulwarty, RS Zhang, JY AF Wohl, EE Pulwarty, RS Zhang, JY TI Assessing climate impacts SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT 2nd Annual Symposium on Chinese-American Frontiers of Science CY AUG 20-22, 1999 CL BEIJING, PEOPLES R CHINA ID RECORD AB Assessing climate impacts involves identifying sources and characteristics of climate variability, and mitigating potential negative impacts of that variability. Associated research focuses on climate driving mechanisms, biosphere-hydrosphere responses and mediation, and human responses. Examples of climate impacts come from 1998 flooding in the Yangtze River Basin and hurricanes in the Caribbean and Central America. Although we have limited understanding of the fundamental driving-response interactions associated with climate variability, increasingly powerful measurement and modeling techniques make assessing climate impacts a rapidly developing frontier of science. C1 NOAA, Off Global Programs, Silver Spring, MD 20910 USA. Colorado State Univ, Dept Earth Resources, Ft Collins, CO 80523 USA. Minist Water Resources, Water Resources Informat Ctr, Beijing 100761, Peoples R China. RP Wohl, EE (reprint author), NOAA, Off Global Programs, Silver Spring, MD 20910 USA. NR 8 TC 0 Z9 0 U1 2 U2 3 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 10 PY 2000 VL 97 IS 21 BP 11141 EP 11142 DI 10.1073/pnas.97.21.11141 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 363GA UT WOS:000089825700004 PM 11027321 ER PT J AU Sortais, Y Bize, S Nicolas, C Clairon, A Salomon, C Williams, C AF Sortais, Y Bize, S Nicolas, C Clairon, A Salomon, C Williams, C TI Cold collision frequency shifts in a Rb-87 atomic fountain SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATE; STANDARD; STATE AB We present measurements of cavity frequency pulling and collisional frequency shifts in a Rb-87 fountain with a frequency resolution of 3 x 10(-16) Agreement with theory is found for the cavity pulling and the measured collisional shifts. The clock shift is found at least 50 times smaller than in Cs-133. C1 Observ Paris, LPTF, BNM, F-75014 Paris, France. ENS, Lab Kastler Brossel, F-75005 Paris, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Observ Paris, LPTF, BNM, 61 Ave Observ, F-75014 Paris, France. RI Williams, Carl/B-5877-2009 NR 17 TC 81 Z9 85 U1 0 U2 4 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 OCT 9 PY 2000 VL 85 IS 15 BP 3117 EP 3120 DI 10.1103/PhysRevLett.85.3117 PG 4 WC Physics, Multidisciplinary SC Physics GA 362ZH UT WOS:000089807800013 PM 11019280 ER PT J AU Jacox, ME Irikura, KK Thompson, WE AF Jacox, ME Irikura, KK Thompson, WE TI The reaction of BF3 with H2O: Infrared spectrum of BF2OH trapped in solid neon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HIGH-RESOLUTION; TRANSITION; (H2O)-O-16; STRENGTHS; ARGON; BANDS AB When a Ne:BF3 sample is passed through a long stainless steel deposition line before being frozen onto a cryogenic observation surface maintained at approximately 5 K, the infrared spectrum of the resulting deposit includes prominent absorptions assigned to BF2OH and weaker absorptions contributed by F-3 B-11-OH2. Pretreatment of the deposition line with isotopically substituted water leads to the appearance of absorptions of the O-18- and D-substituted products. The assignments are supported by the results of ab initio calculations at several different levels and by a least-squares force constant fit to the infrared absorptions of the isotopomers of BF2OH. The thermochemistry of the reactions of BF3 and H2O to form F3B-OH2 and to form BF2OH+HF has been calculated at the G2 level. Although the heats of reaction calculated for 298 K somewhat favor formation of the complex, when the entropy is also considered the two reactions become more competitive. (C) 2000 American Institute of Physics. [S0021-9606(00)00538-9]. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 37 TC 29 Z9 29 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 8 PY 2000 VL 113 IS 14 BP 5705 EP 5715 AR PII [S0021-9606(00)00538-9] DI 10.1063/1.1290287 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 357WU UT WOS:000089524400013 ER PT J AU Rao, CN Reddy, P Reeder, DJ Liu, YY Stack, SM Kisiel, W Woodley, DT AF Rao, CN Reddy, P Reeder, DJ Liu, YY Stack, SM Kisiel, W Woodley, DT TI Prokaryotic expression, purification, and reconstitution of biological activities (antiprotease, antitumor, and heparin-binding) for tissue factor pathway inhibitor-2 SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article DE Kunitz-type serine protease inhibitors; recombinant TFPI-2; heparin; extracellular matrix; prokaryotic expression; protein refolding; antitumor activity; glycosylation ID SERINE-PROTEASE INHIBITOR; PROTEINASE-INHIBITORS; MATRIX DEGRADATION; ESCHERICHIA-COLI; NUDE-MICE; CELLS; PLASMINOGEN; ACTIVATION; METASTASIS; UROKINASE AB We report the expression of tissue factor pathway inhibitor-2 (TFPI-2) (also known as PP-5, placental protein-5; MSPI, matrix-associated serine protease inhibitor) in E. coli as a 25-kDa nonglycosylated protein with a glycine substituted for aspartic acid at the amino terminus. High-level expression of TFPI-2 was obtained with pRE1 expression vector under the transcriptional and translational controls of the lambda P-L promoter and lambda c(II) ribosome-binding site, respectively, with ATG initiation codon. TFPI-2 was produced as inclusion bodies and accounted for 25-30% of the total E. coli proteins. The inclusion bodies containing TFPI-2 were solubilized with urea, sufitolyzed, purified, and refolded through a disulfide interchange reaction. The refolded E. coli TFPI-2 inhibited plasmin with an inhibition constant (K-i) of 5 nM that is similar with the TFPI-2 expressed in a mammalian system. The refolded E. coli TFPI-2 bound heparin and also inhibited plasmin, regardless of whether the enzyme was in the fluid phase or was bound to the membranes of HT-1080 fibrosarcoma cells. In addition, refolded E. coli TFPI-2 inhibited radiolabeled matrix degradation and Matrigel matrix invasion by HT-1080 fibrosarcoma cells and B16-F10 melanoma cells. Together, our results suggest that glycosylation is not essential for antiprotease, antitumor, and matrix-binding activities of TFPI-2, Based on these collective data, we conclude that a biologically active nonglycosylated TFPI-2 can be produced in E. coli and that the protein can be produced in high-enough quantities to conduct in vivo studies for determination of the role of this inhibitor in tumor invasion and metastasis. (C) 2000 Academic Press. C1 Northwestern Univ, Sch Med, Dept Dermatol, Chicago, IL 60611 USA. Northwestern Univ, Sch Med, Dept Obstet & Gynecol, Chicago, IL 60611 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20877 USA. Univ New Mexico, Sch Med, Dept Pathol, Santa Fe, NM 87131 USA. RP Rao, CN (reprint author), Ctr Prostate Dis Res, 1530 E Jefferson St, Rockville, MD 20852 USA. NR 31 TC 8 Z9 19 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD OCT 5 PY 2000 VL 276 IS 3 BP 1286 EP 1294 DI 10.1006/bbrc.2000.3611 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 362TL UT WOS:000089794300073 PM 11027624 ER PT J AU Gilles, MK Talukdar, RK Ravishankara, AR AF Gilles, MK Talukdar, RK Ravishankara, AR TI Rate coefficients for the OH+CF3I reaction between 271 and 370 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID OZONE DEPLETION; CF3I; HOI; PRODUCTS; KINETICS; O(P-3); OH; POTENTIALS; ENERGY; CH3I AB The rate coefficient, k(1), for the reaction OH + CF3I --> products was measured under pseudo-first-order conditions in hydroxyl radical, OH. OH temporal profiles were monitored by laser-induced fluorescence (LIF), and CF3I concentrations were determined by UV/Visible absorption. We determined k(1) (T) to be (2.10 +/- 0.80) x 10(-11) exp[-(2000 +/- 140)/T] cm(3) molecule(-1) s(-1), over the temperature range 271 to 370 K. The quoted uncertainties are 2 sigma (95% confidence limits, sigma(A) = A sigma(lnA)) Previous measurements of k(1)(T) are compared with our values, and possible reasons for the discrepancies are discussed. The heat of formation of HOI is deduced to be less than -16 kcal mole(-1), if the products of reaction 1 are mostly HOI and CF3. These measurements support the earlier conclusion that the reaction of OH with CSI plays a negligibly small role in the atmospheric removal of CF3I. C1 NOAA, ERL, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Gilles, MK (reprint author), NOAA, ERL, Aeron Lab, R-AL2,325 Broadway, Boulder, CO 80305 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 24 TC 9 Z9 9 U1 1 U2 4 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 OCT 5 PY 2000 VL 104 IS 39 BP 8945 EP 8950 DI 10.1021/jp001827i PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 361EY UT WOS:000089711000014 ER PT J AU Allen, MR Stott, PA Mitchell, JFB Schnur, R Delworth, TL AF Allen, MR Stott, PA Mitchell, JFB Schnur, R Delworth, TL TI Quantifying the uncertainty in forecasts of anthropogenic climate change SO NATURE LA English DT Article ID GENERAL-CIRCULATION MODEL; FINGERPRINT METHOD; SULFATE AEROSOLS; GREENHOUSE-GAS; ATMOSPHERE; ATTRIBUTION; SURFACE; RECORD; GCM AB Forecasts of climate change are inevitably uncertain. It is therefore essential to quantify the risk of significant departures from the predicted response to a given emission scenario. Previous analyses of this risk have been based either on expert opinion(1), perturbation analysis of simplified climate models(2-5) or the comparison of predictions from general circulation models(6). Recent observed changes that appear to be attributable to human influence(7-12) provide a powerful constraint on the uncertainties in multi-decadal forecasts. Here we assess the range of warming rates over the coming 50 years that are consistent with the observed near-surface temperature record as well as with the overall patterns of response predicted by several general circulation models. We expect global mean temperatures in the decade 2036-46 to be 1-2.5 K warmer than in pre-industrial times under a 'business as usual' emission scenario. This range is relatively robust to errors in the models' climate sensitivity, rate of oceanic heat uptake or global response to sulphate aerosols as long as these errors are persistent over time. Substantial changes in the current balance of greenhouse warming and sulphate aerosol cooling would, however, increase the uncertainty. Unlike 50-year warming rates, the final equilibrium warming after the atmospheric composition stabilizes remains very uncertain, despite the evidence provided by the emerging signal. C1 Rutherford Appleton Lab, Space Sci & Technol Dept, Didcot OX11 0QX, Oxon, England. Meteorol Off, Hadley Ctr Climate Predict & Res, Bracknell RG12 2SZ, Berks, England. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Allen, MR (reprint author), Rutherford Appleton Lab, Space Sci & Technol Dept, Didcot OX11 0QX, Oxon, England. RI Allen, Myles/A-5172-2012; Delworth, Thomas/C-5191-2014; Stott, Peter/N-1228-2016 OI Stott, Peter/0000-0003-4853-7686 NR 32 TC 215 Z9 219 U1 0 U2 51 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 5 PY 2000 VL 407 IS 6804 BP 617 EP 620 DI 10.1038/35036559 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 362HP UT WOS:000089772800043 ER PT J AU Drohat, AC Stivers, JT AF Drohat, AC Stivers, JT TI Escherichia coli uracil DNA glycosylase: NMR characterization of the short hydrogen bond from His187 to uracil O2 SO BIOCHEMISTRY LA English DT Article ID ISOTOPE FRACTIONATION FACTORS; H-1-NMR CHEMICAL-SHIFTS; N-15 NMR; TRIOSEPHOSPHATE ISOMERASE; ENZYMATIC CATALYSIS; SERINE PROTEASES; ACTIVE-SITE; ELECTROSTATIC STABILIZATION; TRANSITION-STATES; HETERONUCLEAR NMR AB Uracil DNA glycosylase (UDG) cleaves the glycosidic bond of deoxyuridine in DNA using a hydrolytic mechanism, with an overall catalytic rate enhancement of 10(12)-fold over the solution reaction. The nature of the enzyme-substrate interactions that lead to this large rate enhancement are key to understanding enzymatic DNA repair. Using H-1 and heteronuclear NMR spectroscopy, we have characterized one such interaction in the ternary product complex of Escherichia coli UDG, the short (2.7 Angstrom) H bond between His187 N-epsilon 2 and uracil O2. The H bond proton is highly deshielded at 15.6 ppm, indicating a short N-O distance and exhibits a solvent exchange rate that is 400- and 10(5)-fold slower than free imidazole at pH 7.5 and pH 10, respectively. Heteronuclear NMR experiments at neutral pH show that this H bond involves the neutral imidazole form of His187 and the N1-O2 imidate form of uracil. The excellent correspondence of the FK, for the disappearance of the H bond (pK(a) = 6.3 +/- 0.1) with the previously determined pK(a) = 6.4 for the N1 proton of enzyme-bound uracil indicates that the H bond requires negative charge on uracil O2 [Drohat, A. C., and Stivers, J. T. (2000) J. Am. Chem. Sec. 122, 1840-1841]. Although the above characteristics suggest a short strong H bond, the D/H fractionation factor of phi = 1.0 is more typical of a normal H bond. This unexpected observation may reflect a large donor-acceptor pK(alpha) mismatch or the net result of two opposing effects on vibrational frequencies: decreased N-H bond stretching frequencies (phi < 1) and increased bending frequencies (phi > 1) relative to the O-H bonds of water. The role of this H bond in catalysis by UDG and several approaches to quantify the H bond energy are discussed. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Rockville, MD 20850 USA. RP Stivers, JT (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. FU NIGMS NIH HHS [GM56834, R01 GM056834] NR 64 TC 57 Z9 57 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 3 PY 2000 VL 39 IS 39 BP 11865 EP 11875 DI 10.1021/bi000922e PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 360XW UT WOS:000089693500004 PM 11009598 ER PT J AU Schmidt, G Nakatani, AI Butler, PD Karim, A Han, CC AF Schmidt, G Nakatani, AI Butler, PD Karim, A Han, CC TI Shear orientation of viscoelastic polymer-clay solutions probed by flow birefringence and SANS SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; X-RAY-SCATTERING; AQUEOUS KAOLINITE SUSPENSIONS; PARTICLE INTERACTIONS; DISPERSIONS; RHEOLOGY; BEHAVIOR; COLLOIDS; LIGHT C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Schmidt, G (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Butler, Paul/D-7368-2011 NR 35 TC 128 Z9 128 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 OCT 3 PY 2000 VL 33 IS 20 BP 7219 EP 7222 DI 10.1021/ma9918811 PG 4 WC Polymer Science SC Polymer Science GA 361RA UT WOS:000089735800001 ER PT J AU Ogata, HY Shearer, KD AF Ogata, HY Shearer, KD TI Influence of dietary fat and adiposity on feed intake of juvenile red sea bream Pagrus major SO AQUACULTURE LA English DT Article DE red sea bream; dietary fat; feed intake; adiposity; appetite ID FOOD-INTAKE; RAINBOW-TROUT; SALVELINUS-ALPINUS; ATLANTIC SALMON; ARCTIC CHARR; OBESE GENE; GROWTH; ENERGY; PROTEIN; FISH AB A two-phase experiment was conducted to examine the effects of dietary fat and adiposity on feed intake of red sea bream. In Phase 1, juveniles (9.7 g, 20 fish tank(-1), 4 replicates) were fed low fat (LF; 15.3% fat, 60.6% protein, 22.2 kJ g(-1) energy, 0.61 g ml(-1) density) or high fat (HF; 24.6% fat, 54.9% protein, 24.2 kJ g(-1) energy, 0.68 g ml(-1) density) diets for 4 weeks to produce fish which differed in adiposity. In Phase 2, all groups were fed the LF and HF diets alternately for 8 days. Fish were fed to apparent satiation by hand twice daily and daily feed consumption was recorded. Fish were weighed at the start, weekly during Phase 1 and at the end of Phase 2. Proximate composition was determined at the start of the experiment and after Phase I and 2. In Phase 1 the amount (18.6 +/- 0.35 vs. 17.1 +/- 0.19 g) and Volume (30.6 +/- 0.58 vs. 25.2 +/- 0.28 ml) of feed consumed was significantly greater in fish fed the LF diet; energy intakes (LF, 412 +/- 7.8; HF, 413 +/- 4.7 kJ) and terminal mean fish weights (LF, 28.2 +/- 0.5; HF, 27.7 +/- 0.1 g) were similar. Fish fed the HF diet had a significantly higher proportion of visceral (37.6 +/- 1.5 vs. 28.9 +/- 1.2%) and carcass fat (9.7 +/- 0.3 vs. 8.0 +/- 0.3%). In Phase 2, fish fed the LF diet in Phase 1 consumed more of both the LF diet (2.9 +/- 0.2 vs. 2.4 +/- 0.1 g, p < 0.05) and HF diet (3.2 +/- 0.1 vs. 2.9 +/- 0.1 g, P < 0.07). Within each treatment fish consumed equal volumes of HF and LF feed, but the fish fed the LF diet in Phase 1 consumed a significantly greater total volume of feed (9.5 +/- 0.4 vs. 8.1 +/- 0.3 ml). Fish weights at the end of Phase 2 did not differ (LF, 34.6 +/- 0.9 vs. HF, 33.8 +/- 0.4). Our results indicate that the fish ate to meet an energy demand during Phase 1 and suggest that stomach volume increased in fish fed the lower energy (LF) diet, allowing increased meal size. This increase in meal size persisted when these fish were fed alternating HF or LF diets for 8 days (Phase 2). We were unable to unequivocally demonstrate an effect of adiposity on appetite during Phase 2, although this can be inferred since the fish fed the HF diet in Phase 1 should also have had the ability to increase their feed intake during Phase 1, but did not. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Natl Res Inst Aquaculture, Nansei, Mie 5160193, Japan. RP Shearer, KD (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 38 TC 26 Z9 31 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD OCT 2 PY 2000 VL 189 IS 3-4 BP 237 EP 249 DI 10.1016/S0044-8486(00)00374-4 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 344QF UT WOS:000088769800003 ER PT J AU Adams, CP Mason, TE Fawcett, E Menshikov, AZ Frost, CD Forsyth, JB Perring, TG Holden, TM AF Adams, CP Mason, TE Fawcett, E Menshikov, AZ Frost, CD Forsyth, JB Perring, TG Holden, TM TI High-energy magnetic excitations and anomalous spin-wave damping in FeGe2 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID DENSITY-WAVE; ANTIFERROMAGNETISM; SUPERCONDUCTIVITY; SCATTERING; CHROMIUM; DYNAMICS; NICKEL; IRON AB Inelastic neutron scattering has been used to measure the high-energy, low-temperature magnetic excitations of the itinerant antiferromagnet FeGe2. The spin-wave excitations follow a Heisenberg dispersion with exchange constant along the c-axis SJ(FM) = 68 +/- 1 meV an order of magnitude higher than the basal-plane antiferromagnetic constant SJ(AFM) = -4.4 +/- 0.6 meV. The c-axis spin waves are highly damped, even at temperatures small compared to SJ(FM) The damping is roughly quadratic in energy las in the hydrodynamic model) up to similar to 250 meV, beyond which a continuum of excitations emerges. C1 Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Inst Met Phys, Ekaterinburg, Russia. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Natl Res Council, Chalk River, ON K0J 1J0, Canada. RP Adams, CP (reprint author), Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Mason, Thomas/M-5809-2014 OI Mason, Thomas/0000-0003-1880-3971 NR 25 TC 3 Z9 3 U1 1 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 2 PY 2000 VL 12 IS 39 BP 8487 EP 8493 DI 10.1088/0953-8984/12/39/311 PG 7 WC Physics, Condensed Matter SC Physics GA 365MW UT WOS:000089955900014 ER PT J AU Anderson, BP Haljan, PC Wieman, CE Cornell, EA AF Anderson, BP Haljan, PC Wieman, CE Cornell, EA TI Vortex precession in Bose-Einstein condensates: Observations with filled and empty cores SO PHYSICAL REVIEW LETTERS LA English DT Article ID VORTICES; STABILITY; DYNAMICS; SOLITONS; GASES AB We have observed and characterized the dynamics of singly quantized vortices in dilute-gas Bose-Einstein condensates. Our condensates are produced in a superposition of two internal states of Rb-87, with one state supporting a vortex and the other filling the vortex core. Subsequently, the state filling the core can be partially or completely removed, reducing the radius of the core by as much as a factor of 13, all the way down to its bare value of the healing length. The corresponding superfluid rotation rates, evaluated at the core radius, vary by a factor of 150, but the precession frequency of the vortex core about the condensate axis changes by only a factor of 2. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Anderson, BP (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. RI Anderson, Brian/A-2286-2009 OI Anderson, Brian/0000-0002-0442-7867 NR 32 TC 170 Z9 171 U1 3 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 2 PY 2000 VL 85 IS 14 BP 2857 EP 2860 DI 10.1103/PhysRevLett.85.2857 PG 4 WC Physics, Multidisciplinary SC Physics GA 358XA UT WOS:000089581400004 PM 11005953 ER PT J AU Henrickson, SE Misakian, M Robertson, B Kasianowicz, JJ AF Henrickson, SE Misakian, M Robertson, B Kasianowicz, JJ TI Driven DNA transport into an asymmetric nanometer-scale pore SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-ION CHANNEL; AUREUS ALPHA-TOXIN; POLYMER TRANSLOCATION; ESCHERICHIA-COLI; MEMBRANE; MOLECULES; DYNAMICS; SITES AB To understand the mechanism by which individual DNA molecules enter nanometer-scale pores, we studied the concentration and voltage dependence of polynucleotide-induced ionic-current blockades of a single cu-hemolysin ion channel. We find that the blockade frequency is proportional to the polymer concentration, that it increases exponentially with the applied potential, and that DNA enters the pore more readily through the entrance that has the larger vestibule. We also measure the minimum value of the electrical potential that confines a modified polymer inside the pore against random diffusion and repulsive forces. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NIST, Div Elect, Gaithersburg, MD 20899 USA. RP Kasianowicz, JJ (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 30 TC 356 Z9 358 U1 1 U2 50 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 2 PY 2000 VL 85 IS 14 BP 3057 EP 3060 DI 10.1103/PhysRevLett.85.3057 PG 4 WC Physics, Multidisciplinary SC Physics GA 358XA UT WOS:000089581400053 PM 11006002 ER PT J AU Bullock, OR AF Bullock, OR TI Modeling assessment of transport and deposition patterns of anthropogenic mercury air emissions in the United States and Canada SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT 5th International Conference on Mercury as a Global Pollutant CY MAY 23-28, 1999 CL RIO JANEIRO, BRAZIL SP Ctr Miner Technol, Canadian Int Dev Agcy, Brazilian Res Council, Elect Power Res Inst, Res Support Fdn DE mercury; atmospheric; modeling; deposition; emission ID ATMOSPHERIC MERCURY; PRECIPITATION; CHEMISTRY AB In December 1997, the U.S. Environmental Protection Agency submitted its mercury study report to Congress, which included a modeling assessment of the long-range transport and deposition of mercury from various residential and industrial sources within the United States, based on numerical simulations of elemental mercury gas, divalent mercury gas and particulate mercury, using a special version of the Regional Lagrangian Model of Air Pollution (RELMAP). Observations of the deposition of total precipitated mercury at several locations within the U.S. were compared to the modeling results in order to evaluate the accuracy of the RELMAP simulations. However, the lack of Canadian mercury emissions data in the RELMAP modeling limited the usefulness of this model evaluation at locations near the Canadian border. An inventory of Canadian mercury emissions obtained from Environment Canada has now been added to the RELMAP mercury modeling, and the previous simulations and evaluation of modeled wet deposition have been repeated. The results indicate that emissions of mercury from Canada, as represented by the new inventory, do not significantly impact simulated wet deposition over the United States, nor the general results of the previous model evaluation. Analyses of the simulated transport and deposition patterns of mercury emissions from both the United States and Canada are presented, along with the simulated fraction of total mercury wet deposition, separately attributable to sources within each nation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. RP Bullock, OR (reprint author), NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Mail Drop 80, Res Triangle Pk, NC 27711 USA. EM bro@hpcc.epa.gov NR 22 TC 27 Z9 28 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD OCT 2 PY 2000 VL 259 IS 1-3 BP 145 EP 157 PG 13 WC Environmental Sciences SC Environmental Sciences & Ecology GA 358ZJ UT WOS:000089586800016 ER PT J AU Smith, LW AF Smith, LW TI The reproductive biology of an open-water spawning Lake Malawi cichlid, Copadichromis chrysonotus SO AFRICAN ZOOLOGY LA English DT Article DE breeding; dimorphism; fecundity; fertility; gonadosomatic index; maturity; mouthbrooding; spawning; territoriality ID PARENTAL CARE; FISHES; AFRICA; BEHAVIOR; PISCES; EVOLUTION AB Copadichromis chrysonotus is a zooplanktivorous cichlid member of the diverse fish community inhabiting Lake Malawi's rocky, littoral habitat. Like most Lake Malawi cichlids, this species' reproductive strategy is based on maternal mouthbrooding, but it is the only littoral species known to spawn in the open water without a substrate-based territory. This study investigated length at maturity, sexual dimorphism, spawning behaviour, breeding seasonality, fecundity, fertility, egg size, and brooding habits of C, chrysonotus in southern Lake Malawi. Males in breeding colouration aggregated in sheltered areas at least several metres deep, and each male defended a mobile breeding territory near the surface while attempting to attract females. Breeding was mostly continuous from August to May, with peaks in August-September and January-March. A major lull in breeding activity occurred in May and June. Mean fecundity and fertility increased significantly with female total length, while mean egg length, mean egg mass and gonadosomatic index did not increase significantly with female total length. Females brooded their young up to 15-16 mm total length before abandoning them. Open-water spawning by C. chrysonotus may be an adaptation to reduce both egg predation during spawning and competition for substrate-based breeding territories. C1 Lake Malawi Natl Pk, Monkey Bay, Malawi. RP Smith, LW (reprint author), Natl Marine Fisheries Serv, 515 NE Oregon St,Suite 500, Portland, OR 97232 USA. NR 69 TC 1 Z9 1 U1 0 U2 4 PU ZOOLOGICAL SOC SOUTHERN AFRICA PI PRETORIA PA AFRICAN ZOOLOGY CIRCULATION OFFICE, PO BOX 11663,, PRETORIA 0028, SOUTH AFRICA SN 1562-7020 J9 AFR ZOOL JI Afr. Zool. PD OCT PY 2000 VL 35 IS 2 BP 151 EP 164 PG 14 WC Zoology SC Zoology GA 453GD UT WOS:000169907400001 ER PT J AU Wylie, AG Verkouteren, JR AF Wylie, AG Verkouteren, JR TI Amphibole asbestos from Libby, Montana: Aspects of nomenclature SO AMERICAN MINERALOGIST LA English DT Article AB Richterite-asbestos and winchite-asbestos are not listed in the federal regulations governing asbestos. However, asbestiform winchite is found in the gangue at the Libby, Montana, vermiculite deposit, where asbestos-related diseases have been reported among the miners and millers. Changing amphibole nomenclature, uncertainties in Fe2+/Fe3+, and natural compositional variability result in samples of the asbestiform amphibole from Libby being variably classified as soda tremolite, richterite, sub-calcic actinolite, and winchite. A classification of winchite-asbestos is assigned for two samples of Libby asbestos analyzed for this report, consistent with the most recent International Mineralogical Association classification system. Although some of the unit-cell parameters and optical properties reported here are distinctive, others are very similar to the tremolite-actinolite series. C1 Univ Maryland, Dept Geol, Lab Mineral Deposits Res, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Wylie, AG (reprint author), Univ Maryland, Dept Geol, Lab Mineral Deposits Res, College Pk, MD 20742 USA. NR 14 TC 42 Z9 43 U1 0 U2 6 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD OCT PY 2000 VL 85 IS 10 BP 1540 EP 1542 PG 3 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 361NJ UT WOS:000089728900028 ER PT J AU Minh, TB Nakata, H Watanabe, M Tanabe, S Miyazaki, N Jefferson, TA Prudente, M Subramanian, A AF Minh, TB Nakata, H Watanabe, M Tanabe, S Miyazaki, N Jefferson, TA Prudente, M Subramanian, A TI Isomer-specific accumulation and toxic assessment of polychlorinated biphenyls, including coplanar congeners, in cetaceans from the North Pacific and Asian coastal waters SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID PERSISTENT ORGANOCHLORINE CONTAMINANTS; WHALES DELPHINAPTERUS-LEUCAS; MUSSELS PERNA-VIRIDIS; HONG-KONG; AQUATIC ECOSYSTEMS; RISK ASSESSMENT; MARINE MAMMALS; PCBS; SEA; DOLPHINS AB To elucidate the global distribution and toxicological impacts of polychlorinated biphenyls (PCBs) on cetaceans, the present study determined the concentrations of individual PCB congeners, including toxic non-ortho (IU PAC Nos. 77, 126, 169) and mono-ortho (IUPAC Nos. 105, 118, 156) coplanar congeners, in the blubber of 10 species of adult male odontocetes collected from several locations in the North Pacific Ocean and along coastal waters of Japan, Hong Kong, the Philippines, and India during 1985-1997. Total PCB concentrations in cetaceans from temperate and cold waters were higher than those in cetaceans from tropical regions. Residue levels were found to be the highest in Fraser's dolphins collected off Kii Peninsula, Japan, and hump-backed dolphins from Hong Kong, reflecting Serious marine pollution by PCBs in industrialized Asian countries. Penta- and hexa-chlorobiphenyls were the predominant PCB congeners, accounting for about 70% of the total PCBs. 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents (TEQs) of non- and mono-ortho coplanar PCBs in the blubber of cetaceans ranged from 36 (in spinner dolphins from the Philippines) to 510 pg/g wet weight (in hump-backed dolphins from Hong Kong). Toxic evaluation of coplanar PCBs using the TEQ concept indicates an greater impact on cetaceans from mid-latitudes. Toxicity contribution of mono-ortho congener IUPAC 118 was prominent in species from high latitude oceans, such as the Bering Sea and the North Pacific, whereas non-ortho congener IUPAC 126 accounted for the highest contribution in cetaceans from lower latitude regions, such as the Philippines and India. The estimated TEQ concentrations in the blubber of some cetacean species, such as northern right whale dolphin and Pacific white-sided dolphin from the northern North Pacific, Dall's porpoise from the Japan Sea, striped dolphin off Sanriku and Fraser's dolphin off Kii Peninsula, Japan, hump-backed dolphin and finless porpoise from Hong Kong, exceeded the levels associated with immunosuppression in harbour seals. C1 Ehime Univ, Ctr Marine Environm Studies, Matsuyama, Ehime 7908566, Japan. Kumamoto Univ, Grad Sch Nat Sci & Technol, Dept Environm Sci, Kumamoto 8608555, Japan. Univ Tokyo, Ocean Res Inst, Otsuchi Marine Res Ctr, Otsuchi, Iwate 0281102, Japan. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, NOAA, La Jolla, CA 92038 USA. Ocean Pk Conservat Fdn, Aberdeen, Hong Kong, Peoples R China. De La Salle Univ, Sci Educ Dept, Manila 1004, Philippines. Annamalai Univ, Ctr Adv Study Marine Biol, Parangipettai 608502, India. RP Tanabe, S (reprint author), Ehime Univ, Ctr Marine Environm Studies, Tarumi 3-5-7, Matsuyama, Ehime 7908566, Japan. RI Tanabe, Shinsuke/G-6950-2013; OI Miyazaki, Nobuyuki/0000-0001-8094-683X NR 44 TC 45 Z9 55 U1 6 U2 16 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 2000 VL 39 IS 3 BP 398 EP 410 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 352QA UT WOS:000089228300017 PM 10948292 ER PT J AU Gibson, BK Giroux, ML Penton, SV Putman, ME Stocke, JT Shull, JM AF Gibson, BK Giroux, ML Penton, SV Putman, ME Stocke, JT Shull, JM TI Metal abundances in the Magellanic Stream SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (III Zw 2, Fairall 9, NGC 7469); galaxies : Seyfert; galaxy : halo; Magellanic Clouds ID HIGH-VELOCITY CLOUDS; INTERSTELLAR ABUNDANCES; ABSORPTION-LINES; CHEMICAL-COMPOSITION; GALACTIC HALO; MILKY-WAY; ORIGIN; GAS; METALLICITY; WAVELENGTHS AB We report on the first metallicity determination for gas in the Magellanic Stream, using archival. Hubble Space Telescope (HST) GHRS data for the background targets Fairall 9, III Zw 2, and NGC 7469. For Fairall 9, using two subsequent HST revisits and new Parkes multibeam narrowband observations, we have unequivocally detected the MS I H I component of the Stream (near its head) in S II lambda lambda 1250, 1253, yielding a metallicity of [S II/H] = -0.55 +/- 0.06(r)(-0.21)(+0.17)(s), where r and s are the associated random and systematic uncertainties, consistent with either an SMC or LMC origin and with the earlier upper limit set recently by Lu, Savage, & Sembach. We also detect the saturated Si II lambda 1260 line, but set a lower limit of only [Si II/H] greater than or similar to -1.5. We present two HST serendipitous detections of the Stream, seen in Mg II lambda lambda 2796, 2803 absorption with column densities of (0.5-1) x 10(13) cm(-2) toward the Seyfert galaxies III Zw 2 and NGC 7469. These latter sight lines probe gas near the tip of the Stream (similar to 15 degrees from the peak of the MS V H I component and similar to 80 degrees down-Stream of Fairall 9). For III Zw 2, the lack of an accurate H I column density determination and the uncertain Mg III ionization correction severely limit the degree to which we can constrain [Mg/H]; we found a lower limit of [Mg II/H I] greater than or similar to -1.3 for this sight line. For NGC 7469, an accurate H I column density determination exists, but the extant Faint Object Spectrograph (FOS) spectrum limits our ability to constrain the Mg II column density, and we conclude that [Mg II/H I] greater than or similar to -1.5 for this sight line. Ionization corrections associated with Mg III and H II suggest that the corresponding [Mg/H] may range lower by similar to 0.3-1.0 dex. However, an upward revision of similar to 0.5-1.0 dex would be expected under the assumption that the Stream exhibits a dust depletion pattern similar to that seen in both the Large and Small Magellanic Clouds. While our abundance analysis allows us to rule out a primordial origin for the Stream, the remaining systematic uncertainties in the H I column density along the lines of sight makes it difficult to differentiate between an LMC and an SMC origin. C1 Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. RP Gibson, BK (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Campus Box 389, Boulder, CO 80309 USA. RI Gibson, Brad/M-3592-2015 OI Gibson, Brad/0000-0003-4446-3130 NR 46 TC 61 Z9 61 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 OCT PY 2000 VL 120 IS 4 BP 1830 EP 1840 DI 10.1086/301545 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 364GQ UT WOS:000089884400020 ER PT J AU Augustine, JA DeLuisi, JJ Long, CN AF Augustine, JA DeLuisi, JJ Long, CN TI SURFRAD - A national surface radiation budget network for atmospheric research SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PROGRAM; CLOUD AB A surface radiation budget observing network (SURFRAD) has been established for the United States to support satellite retrieval validation, modeling, and climate, hydrology, and weather research. The primary measurements are the downwelling and upwelling components of broadband solar and thermal infrared irradiance. A hallmark of the network is the measurement and computation of ancillary parameters important to the transmission of radiation. SURFRAD commenced operation in 1995. Presently, it, is made up of six stations in diverse climates, including the moist subtropical environment of the U.S. southeast, the cool and dry northern plains, and the hot and arid desert southwest. Network operation involves a rigorous regimen of frequent calibration, quality assurance, and data quality control. An efficient supporting infrastructure has been created to gather, check, and disseminate the basic data expeditiously. Quality controlled daily processed data files from each station are usually available via the Internet within a day of real time. Data from SURFRAD have been used to validate measurements from NASA's Earth Observing System series of satellites, satellite-bused retrievals of surface erythematogenic radiation, the national ultraviolet index, and real-time National Environmental Satellite, Data, and Information Service (NESDIS) products. It has also been used for carbon sequestration studies, to check radiative transfer codes in various physical models, for basic research and instruction at universities, climate research, and fur many other applications. Two stations now have atmospheric energy flux and soil heat flux instrumentation, making them full surface energy balance sites. It is hoped that eventually all SURFRAD stations will have this capability. C1 NOAA, Air Resources Lab, Surface Radiat Res Branch, Boulder, CO 80303 USA. Pacific NW Natl Lab, Radiat Measurement Program, Richland, WA 99352 USA. RP Augustine, JA (reprint author), NOAA, Air Resources Lab, Surface Radiat Res Branch, 325 Broadway, Boulder, CO 80303 USA. NR 18 TC 162 Z9 162 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 2000 VL 81 IS 10 BP 2341 EP 2357 DI 10.1175/1520-0477(2000)081<2341:SANSRB>2.3.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 359QR UT WOS:000089624000002 ER EF