FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Baird, RC AF Baird, RC TI Sea grant: Policy, performance and programs SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Natl Sea Grant Coll Program, Silver Spring, MD 20910 USA. RP Baird, RC (reprint author), NOAA, Natl Sea Grant Coll Program, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD JAN PY 2000 VL 41 IS 1 BP 41 EP 43 PG 3 WC Engineering, Ocean SC Engineering GA 280CP UT WOS:000085084900013 ER PT B AU Marzban, C Witt, A AF Marzban, C Witt, A GP AMS AMS TI A neural network for hail size prediction SO SECOND CONFERENCE ON ARTIFICIAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd Conference on Artificial Intelligence CY FEB 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID DOPPLER RADAR; VERIFICATION C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Marzban, C (reprint author), Natl Severe Storms Lab, Norman, OK 73069 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 38 EP 44 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BS02Y UT WOS:000168377900007 ER PT B AU Lakshmanan, V Rabin, R DeBrunner, V AF Lakshmanan, V Rabin, R DeBrunner, V GP AMS AMS TI Identifying and tracking storms in satellite images SO SECOND CONFERENCE ON ARTIFICIAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd Conference on Artificial Intelligence CY FEB 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc AB Both the correlation methods and cell-identification methods currently used to identify and track individual storms in remotely sensed weather images have drawbacks. A hybrid method is introduced wherein we use segmentation-based approach to identify storms in images and arrange the identified storms heirarchially. A genetic-algorithm method of matching these segmented regions across frames is also introduced. We show how this method can easily handle splits and merges of storm cells. Since it deals with all scales, this method should, theoretically, overcome the drawbacks inherent in the cross-correlation and cell-tracking methods. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Lakshmanan, V (reprint author), Natl Severe Storms Lab, Norman, OK 73069 USA. NR 6 TC 4 Z9 5 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 90 EP 95 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BS02Y UT WOS:000168377900018 ER PT B AU Jarrell, JD AF Jarrell, JD GP AMS AMS TI Collaborations between meteorologists and emergency managers: Hurricanes SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Hurricane Ctr, Trop Predict Ctr, Miami, FL 33165 USA. RP Jarrell, JD (reprint author), Natl Hurricane Ctr, Trop Predict Ctr, Miami, FL 33165 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 2000 BP 17 EP 17 PG 1 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300002 ER PT B AU Gaffen, DJ Ross, RJ Wang, JXL AF Gaffen, DJ Ross, RJ Wang, JXL GP AMS AMS TI Observed trends in summertime extreme heat events in the US and China SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID UNITED-STATES; WATER-VAPOR; TEMPERATURE; CLIMATOLOGY; IMPACTS; MAXIMUM C1 NOAA, R E AR, Silver Spring, MD 20910 USA. RP Gaffen, DJ (reprint author), NOAA, R E AR, 1315 East West Hwy, Silver Spring, MD 20910 USA. EM dian.gaffen@noaa.gov RI Wang, Julian/C-3188-2016 NR 16 TC 0 Z9 0 U1 0 U2 2 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 53 EP 56 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300010 ER PT B AU Richards, F AF Richards, F GP AMS AMS TI A twentieth century history of flooding in the US and what the future might hold SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. RP Richards, F (reprint author), Natl Weather Serv, Off Hydrol, 1325 E W Hwy 7214, Silver Spring, MD 20910 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 2000 BP 144 EP 151 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300027 ER PT B AU Schaefer, JT Brooks, HE AF Schaefer, JT Brooks, HE GP AMS AMS TI Convective storms and their impact SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID UNITED-STATES; FLASH-FLOOD; CLIMATOLOGY; EVENTS; RADAR C1 NOAA, Natl Weather Serv, Storm Predict Ctr, Norman, OK 73069 USA. RP Schaefer, JT (reprint author), NOAA, Natl Weather Serv, Storm Predict Ctr, 1313 Halley Cr, Norman, OK 73069 USA. NR 35 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 152 EP 159 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300028 ER PT B AU Crowe, M Karl, T AF Crowe, M Karl, T GP AMS AMS TI Modern climatic data applications SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NOAA, Natl Climate Data Ctr, Asheville, NC 28801 USA. RP Crowe, M (reprint author), NOAA, Natl Climate Data Ctr, 151 Patton Ave, Asheville, NC 28801 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 2000 BP 198 EP 198 PG 1 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300039 ER PT B AU Horvitz, A Leffler, R Changery, M Taylor, G AF Horvitz, A Leffler, R Changery, M Taylor, G GP AMS AMS TI The National Climate Extremes Committee SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NOAA, Natl Weather Serv, Silver Spring, MD 20910 USA. RP Horvitz, A (reprint author), NOAA, Natl Weather Serv, 1325 East West Highway, Silver Spring, MD 20910 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 2000 BP 201 EP 202 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300041 ER PT B AU Rutledge, GK Stanley, A Page, E Spayd, L Brundage, J AF Rutledge, GK Stanley, A Page, E Spayd, L Brundage, J GP AMS AMS TI Applications for the NOAAPort Data Archive and Retrieval System (NDARS) at the National Climatic Data Center SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Rutledge, GK (reprint author), Natl Climat Data Ctr, Asheville, NC 28801 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 2000 BP 203 EP 206 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300042 ER PT B AU Concannon, PR Brooks, HE Doswell, CA AF Concannon, PR Brooks, HE Doswell, CA GP AMS AMS TI Climatological risk of strong and violent tornadoes in the United States SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Brooks, HE (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 5 TC 11 Z9 11 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 212 EP 219 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300045 ER PT B AU Crowe, M Karl, TR AF Crowe, M Karl, TR GP AMS AMS TI Developing and tracking climate indices for the weather derivatives market SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID UNITED-STATES; INDEXES C1 NOAA, Natl Climate Data Ctr, Asheville, NC 28801 USA. RP Crowe, M (reprint author), NOAA, Natl Climate Data Ctr, 151 Patton Ave, Asheville, NC 28801 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 2000 BP 231 EP 232 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300049 ER PT S AU Proctor, F Michaloski, J Birla, S Weinert, G AF Proctor, F Michaloski, J Birla, S Weinert, G BE Orban, PE Knopf, GK TI Analysis of behavioral requirements for component-based machine controllers SO SENSORS AND CONTROLS FOR INTELLIGENT MANUFACTURING 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 CY NOV 07, 2000 CL BOSTON, MA SP SPIE DE Finite State Machine; component; module; control; standard; modularity; machine; ppen architecture AB Machine controllers built from standardized software components have the greatest potential to reap open architecture benefits - including plug-and-play, reusability and extensibility. A challenge to component-based controllers relates to standardizing behavior in a non-restrictive manner to accommodate component packaging and component integration Control component packaging requires behavior to be dependable, well-defined, and well-understood among a variety of users to help ensure the reusability of the component, the reliability of the component, and the correctness of the system built using the component. Integration of control components requires that the behavior model is consistent not just within a single component, but across all components in a system so that the components interoperate correctly. At the same time, the component behavioral model must be reasonably flexible to accommodate all behavioral situations and not be restrictive to a single programming methodology. Further, not all the behavior in the system may be pre-packaged as part of a component. Thus, another issue is the suitability of the standard behavior model for programming and integration of new control logic, Ideally, we need a vendor-neutral, tool-neutral, controller-neutral behavior model to allow the export/import of any and all types of control logic programs. This paper will analyze the requirements of component-based, machine controller behavior, then offer a refinement of a Finite State Machine as the basis of a behavior model to satisfy these requirements. Examples will be presented based on the behavioral model the efforts of the Open, Modular, Architecture Controller (OMAC) User's Group Application Programming Interface (API) for standardized, interchangeable machine controller components. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Proctor, F (reprint author), Natl Inst Stand & Technol, MS 8230, Gaithersburg, MD 20899 USA. NR 7 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 0-8194-3856-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4191 BP 10 EP 18 PG 9 WC Automation & Control Systems; Computer Science, Interdisciplinary Applications; Engineering, Manufacturing SC Automation & Control Systems; Computer Science; Engineering GA BS07U UT WOS:000168562000002 ER PT S AU Shackleford, WP Proctor, FM AF Shackleford, WP Proctor, FM BE Orban, PE Knopf, GK TI Use of open source distribution for a machine tool controller SO SENSORS AND CONTROLS FOR INTELLIGENT MANUFACTURING 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 CY NOV 07, 2000 CL BOSTON, MA SP SPIE DE open architecture; open source; open architecture control; computer-numerical control; real-time control; Linux AB In recent years a growing number of government and university labs, non-profit organizations and even a few for-profit corporations have found that making their source code public is good for both developers and users. In machine tool control, a growing number of users are demanding that the controllers they buy be "open architecture," which would allow third parties and end-users at least limited ability to modify, extend or replace the components of that controller. This paper examines the advantages and dangers of going one step further, and providing "open source" controllers by relating the experiences of users and developers of the Enhanced Machine Controller (EMC). We also examine some implications for the development of standards for open-architecture but closed-source controllers. Some of the questions we hope to answer include: How can the quality be maintained after the source code has been modified? Can the code be trusted to run on expensive machines and parts, or when the safety of the operator is an issue? Can "open-architecture" but closed-source controllers ever achieve the level of flexibility or extensibility that open-source controllers can? C1 NIST, Gaithersburg, MD 20899 USA. RP Shackleford, WP (reprint author), NIST, 100 Bur Dr,Stop 8230, Gaithersburg, MD 20899 USA. NR 31 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 0-8194-3856-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4191 BP 19 EP 30 PG 12 WC Automation & Control Systems; Computer Science, Interdisciplinary Applications; Engineering, Manufacturing SC Automation & Control Systems; Computer Science; Engineering GA BS07U UT WOS:000168562000003 ER PT S AU Stouffer, K Horst, J AF Stouffer, K Horst, J BE Orban, PE Knopf, GK TI Controller driven VRML animation of the next generation inspection system (NGIS) real-time controller SO SENSORS AND CONTROLS FOR INTELLIGENT MANUFACTURING 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 CY NOV 07, 2000 CL BOSTON, MA SP SPIE DE online monitoring; open architecture control; remote access and inspection; VRML AB Virtual objects in a web-based environment can be interfaced to and controlled by external real world controllers. A Virtual Reality Modeling Language (VRML) inspection cell was created that models a real-time inspection system. The tested consists of a Cordax Coordinate Measuring Machine (CMM), a vision system for determining the part position and orientation, and an open architecture controller. Because of the open architecture, data such as the probe position and the part position and orientation, can be obtained from the controller to drive a VRML model of the system. The VRML CMM is driven using a socket connection between the collaborator's web browser and the real world controller. The current probe position, which is stored in a world model buffer in the controller, is collected by a Java applet running on the web page. The applet updates the VRML model of the CMM via the External Authoring Interface (EAI) of the VRML plug-in. The part position and orientation is obtained from the vision system and the part is updated in the VRML model to represent the part's real world position and orientation. The remote access web site also contains a client-controlled pan/tilt/zoom camera, which sends video to the client allowing them to monitor a remote inspection with a PC and an Internet connection. C1 NIST, Gaithersburg, MD 20899 USA. RP Stouffer, K (reprint author), NIST, 100 Bur Dr,Stop 823, Gaithersburg, MD 20899 USA. NR 5 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 0-8194-3856-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4191 BP 31 EP 37 PG 7 WC Automation & Control Systems; Computer Science, Interdisciplinary Applications; Engineering, Manufacturing SC Automation & Control Systems; Computer Science; Engineering GA BS07U UT WOS:000168562000004 ER PT J AU Ahmed, F Cole, KD AF Ahmed, F Cole, KD TI Affinity liquid chromatographic systems SO SEPARATION AND PURIFICATION METHODS LA English DT Article ID PURIFICATION; SUPPORTS; ADSORPTION; POLYMERS; PROTEINS C1 Phenomenex Inc, Torrance, CA 90501 USA. Natl Inst Stand & Technol, Bioproc Engn Grp, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Ahmed, F (reprint author), Phenomenex Inc, 2320 W 205th St, Torrance, CA 90501 USA. NR 38 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 1 EP 25 DI 10.1081/SPM-100100001 PG 25 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900001 ER PT J AU Bruno, TJ AF Bruno, TJ TI A review of capillary and packed column gas chromatographs SO SEPARATION AND PURIFICATION METHODS LA English DT Article DE gas chromatography; data systems; detectors; injectors AB In this review, the essential aspects of gas chromatography are discussed. The article begins with a very brief discussion of basic chromatographic theory, followed by an in-depth treatment of the instrumentation involved. This discussion starts a discussion of chromatographic columns, the distinctions among which are used to classify the different modes of gas chromatography. Following this is an in-depth discussion of instrumentation, the treatment of which follows the classification by column types; This discussion includes the operational principles and applications of injectors, detectors and data handling systems. In conclusion, a listing of suggested further reading is provided. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 27 EP 61 DI 10.1081/SPM-100100002 PG 35 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900002 ER PT J AU Bruno, TJ AF Bruno, TJ TI A review of hyphenated chromatographic instrumentation SO SEPARATION AND PURIFICATION METHODS LA English DT Review DE atomic emission spectrometry; gas chromatography; liquid chromatography; supercritical fluid chromatography; infrared spectrophotometry; mass spectrometry C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 63 EP 89 DI 10.1081/SPM-100100003 PG 27 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900003 ER PT J AU Pellegrino, J AF Pellegrino, J TI Filtration and ultrafiltration equipment and techniques SO SEPARATION AND PURIFICATION METHODS LA English DT Article AB The spectrum of filtration separations runs from the millimeter scale (beach sand and activated carbon particles) using coarse filters, to the angstrom scale (metal ions and gas molecules) using reverse osmosis or gas separation membranes. Between there are microfiltration (bacteria and emulsions), ultrafiltration (proteins, viruses, and colloids), and nanofiltration (sugars, herbicides, small organic molecules). In the analytical environment it is likely that membrane and filtration systems involving this entire spectrum will be used to provide high purity water, gases, reagents, and even special functions within instruments. In addition to these applications, membranes and filters will often also be used in sample preparation and perhaps initial characterization. In this entry, we will discuss the principles, materials, and devices used to accomplish coarse, micro- and ultrafiltration on the laboratory scale. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Pellegrino, J (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. OI PELLEGRINO, JOHN/0000-0001-7749-5003 NR 4 TC 3 Z9 3 U1 0 U2 4 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 91 EP 118 DI 10.1081/SPM-100100004 PG 28 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900004 ER PT J AU Mitchell, GD AF Mitchell, GD TI A review of permeation tubes and permeators SO SEPARATION AND PURIFICATION METHODS LA English DT Review DE calibration; permeators; permeation tubes AB In this review, the basic principles underlying the design and application of permeation tubes and permeators are discussed. The fundamental theory is cast in terms of Fick's Laws and Henry's law. The various types of polymer materials and permeation tube devices are then discussed, with a view toward the final application of the devices. Finally, calibration and and lifetime issues are treated. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Mitchell, GD (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 10 TC 12 Z9 12 U1 0 U2 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 119 EP 128 DI 10.1081/SPM-100100005 PG 10 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900005 ER PT J AU Todd, P Pellegrino, J AF Todd, P Pellegrino, J TI Electrokinetic analyzers SO SEPARATION AND PURIFICATION METHODS LA English DT Article AB Electrokinetic analysis is a family of techniques for estimating the charge on solid surfaces, macroscopic particles, colloidal species, and macromolecular aggregates. Charges on surfaces are critical to the behavior of colloids, coatings, films, fibers, and many other materials in a variety of application areas. In addition to estimating the charge, electrokinetic analysis provides the means for measuring how the surrounding medium and imposed electric fields interact with extended flat surfaces, channels, pores, particles, and molecular aggregates to produce motion. Such motion has found wide use as a means for separating complex mixtures into their components. This section will present how measurements are made, some theoretical underpinnings, and examples of the instrumentation used for making measurements. C1 Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Univ Colorado, Dept Chem Engn, Campus Box 424, Boulder, CO 80309 USA. OI PELLEGRINO, JOHN/0000-0001-7749-5003 NR 10 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-2540 J9 SEPAR PURIF METHOD JI Sep. Purif. Methods PY 2000 VL 29 IS 1 BP 149 EP 169 DI 10.1081/SPM-100100007 PG 21 WC Chemistry, Analytical; Engineering, Chemical SC Chemistry; Engineering GA 361DG UT WOS:000089706900007 ER PT B AU Michel, M Devaney, JE AF Michel, M Devaney, JE BE Shibata, Y TI A generalized approach for transferring data-types with arbitrary communication libraries SO SEVENTH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS: WORKSHOPS, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on Parallel and Distributed Systems Workshops (ICPADS 2000) CY JUL 04-07, 2000 CL IWATE, JAPAN SP IEEE Comp Soc, Iwate Prefectural Univ, Takizawa Village, Morioka City, Commun Res Lab of Minist PO, IEEE Taipei Sect, Informat Processing Soc Japan, Iwate Prefectural AB We present a generalized algorithm for implementing a communications library for dynamic data structures created with heterogeneous composed data types such us multiple C structs, and where rite data-types may De nested and may contain pointers. This algorithm is divided into an absolute part that is the same for all instantiations, and a relative part that is specific to the communications mechanism used, such as PVM or MPI. We describe the algorithm in terms of our AutoMap/AutoLink implementation in C/MPI. First, we will talk of the MPI case and of the AutoMap and AutoLink solutions (with ideas from version 3.0). Then we discuss what is to be followed in or-der to generalize the data-types transfer concepts presented by this article. With this addition to AutoMap/AutoLink we can ex-tend the functions provided from the current send and receive functions (blocking and non blocking) available for any data-types, to any kind of transfer function;from broadcast to reduce las long as the reduce called process is "message aware "). This will also simplify the extension of this work to data-types load balancing. C1 NIST, Gaithersburg, MD 20899 USA. RP Michel, M (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0571-6 PY 2000 BP 83 EP 87 DI 10.1109/PADSW.2000.884519 PG 3 WC Computer Science, Theory & Methods SC Computer Science GA BQ99Q UT WOS:000165310500013 ER PT S AU Edgar, JH Robins, LH Coatney, SE Liu, L Chaudhuri, J Ignatiev, K Rek, Z AF Edgar, JH Robins, LH Coatney, SE Liu, L Chaudhuri, J Ignatiev, K Rek, Z BE Carter, CH Devaty, RP Rohrer, GS TI A comparison of aluminum nitride freely nucleated and seeded on 6H-silicon carbide SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE bulk crystal growth; cathodoluminescence; Raman spectroscopy; X-ray topography ID SINGLE-CRYSTALS AB The crystal quality, vibrational and luminescence properties of AlN crystals prepared by the sublimation-recondensation method with free nucleation on the crucible walls or seeded growth on 6H-SiC wafers were compared. Freely nucleated needles and platelets exhibited near-band-edge cathodoluminescence, narrow Raman peak widths, and a relatively low dislocation density as revealed by synchrotron white-beam x-ray topography. In contrast, thick films deposited on on-axis, (0001) 6H-silicon carbide wafers exhibited luminescence only at 3.5 eV, had much broader Raman peak widths, and a mosaic crystal structure. C1 Kansas State Univ, Dept Chem Engn, Manhattan, KS 66506 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Edgar, JH (reprint author), Kansas State Univ, Dept Chem Engn, Durland Hall, Manhattan, KS 66506 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 5 TC 11 Z9 11 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1599 EP 1602 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700388 ER PT S AU Andrews, JB Hayes, LJ Arikawa, Y Coriell, SR AF Andrews, JB Hayes, LJ Arikawa, Y Coriell, SR BE Roosz, A Rettenmayr, M Watring, D TI Microgravity solidification of Al-In alloys SO SOLIDIFICATION AND GRAVITY 2000 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 3rd International Conference on Solidification and Gravity (SG 99) CY APR 25-29, 1999 CL MISKOLC LILLAFURED, HUNGARY SP Univ Miskolc, Fac Met, Phys Met Dept, Darmstadt Univ Technol, Mat Sci Inst, NASA Marshall Space Flight Ctr, Hungarian Acad Sci, Miskolc Comm, Hungarian Astronaut Soc, Hungarian Space Off, ASM Hungarian Chapter DE immiscibles; microgravity; directional solidification AB Several aluminum-indium alloy samples were directionally solidified under microgravity conditions during the Life and Microgravity Spacelab Mission in 1996. These samples were processed as part of the "Coupled Growth in Hypermonotectics'' night experiment which is scheduled for completion aboard the International Space Station. The overall objective of this flight experiment is to obtain a fundamental understanding of the physics controlling solidification processes in immiscible alloy systems. Convective instability is anticipated in the Al-In alloys processed due to the low density solute depleted boundary layer that forms in advance of the solidification front. The three samples were processed using the Advanced Gradient Heating Facility and consisted of a 17.3 wt%In monotectic composition sample and two hypermonotectic composition samples, one containing 18.5 wt%In and the other 19.7 wt%In. Post flight analysis revealed the presence of small voids in two of the night samples which may have had an impact on the ability to maintain steady state growth conditions. Precision density measurements revealed compositional variations along the length of ground processed samples which were representative of results anticipated due to convective mixing in the melt. Flight samples showed an initial compositional variation indicative of minimal mixing in the melt. Interface stability was obtained in one of the hypermonotectic flight samples over a region of the sample. Microstructural comparisons between flight samples indicate the increased volume fraction of the aligned rod-like phase in hypermonotectic samples is accommodated by an increased number of rods in the structure but a minimal change in rod diameter. C1 Univ Alabama, Birmingham, AL 35294 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Andrews, JB (reprint author), Univ Alabama, Birmingham, AL 35294 USA. NR 9 TC 3 Z9 3 U1 2 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-852-4 J9 MATER SCI FORUM PY 2000 VL 329-3 BP 247 EP 257 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ57Z UT WOS:000088851000036 ER PT S AU Weiss, A Zimmermann, G Rex, S Coriell, SR AF Weiss, A Zimmermann, G Rex, S Coriell, SR BE Roosz, A Rettenmayr, M Watring, D TI Investigation on morphological instability during directional solidification on a sounding rocket SO SOLIDIFICATION AND GRAVITY 2000 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 3rd International Conference on Solidification and Gravity (SG 99) CY APR 25-29, 1999 CL MISKOLC LILLAFURED, HUNGARY SP Univ Miskolc, Fac Met, Phys Met Dept, Darmstadt Univ Technol, Mat Sci Inst, NASA Marshall Space Flight Ctr, Hungarian Acad Sci, Miskolc Comm, Hungarian Astronaut Soc, Hungarian Space Off, ASM Hungarian Chapter DE initial transient; transparent alloy; microgravity; power-down-technique; crystal-melt interface; planar-cellular transition; cellular array AB The morphological instability of a solid-liquid interface in directional solidification was investigated under diffusive conditions during a sounding rocket flight. The use of the transparent binary alloy Succinonitrile-Acetone allowed an in-situ observation of the evolution of interfacial perturbations. By applying a quite high cooling rate the morphological instability occured at the beginning of the initial transient of the solidification phase. Both the accelerated movement of the planar solidification front until instability and the formation of cellular structure are compared under mu g and 1g conditions. The time-dependent change of cellular solidification morphology is represented by the characteristic parameters primary spacing and cell amplitude. C1 ACCESS EV, DE-52072 Aachen, Germany. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Weiss, A (reprint author), ACCESS EV, Intzestr 5, DE-52072 Aachen, Germany. NR 11 TC 4 Z9 4 U1 1 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-852-4 J9 MATER SCI FORUM PY 2000 VL 329-3 BP 277 EP 284 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ57Z UT WOS:000088851000040 ER PT S AU Black, D Gallagher, T Arnowitz, L AF Black, D Gallagher, T Arnowitz, L BE ElGenk, MS TI Applying x-ray tomography and diffractometry to improve protein crystal growth SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2000) CY JAN 30-FEB 03, 2000 CL ALBUQUERQUE, NM SP Boeing Co, Lockheed Martin Corp, NASA, US DOE, Sandia Natl Lab, Los Almos Natl Lab, Amer Astronaut Soc, Amer Inst Chem Engineers, Div Heat Transfer & Energy Convers, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer inst Aeronaut & Astronaut, Local Sect, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Div Nucl Engn, Amer Soc Mech Engineers, Div Heat Transfer, Inst Elect & Electr Engineers Inc, Nucl & Plasma Sci Soc, Int Astronaut Federat, NASA, Natl Space Grant Coll & Fellowship Program, New Mexico Space grant Consortium AB In order to obtain adequate diffraction data to determine the structure of the protein of interest, crystal quality is important. Although in this context there may be no single concise definition of quality, it must involve adequate size, singleness (ideally the crystal comprises a single molecular lattice), and several diffraction criteria. Diffraction is key to the crystal's usefulness: resolution and mosaicity are the two best estimators of diffraction quality, yet each is difficult to measure objectively. In the final analysis, every protein presents its own challenges to obtaining well-diffracting crystals, and there is probably no single definition of quality that will do for all cases. This paper describes the growth of ribonuclease S crystals under otherwise similar conditions in space and on earth and the techniques used to compare the crystals that were obtained. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Black, D (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 5 TC 1 Z9 1 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 1-56396-919-X J9 AIP CONF PROC PY 2000 VL 504 BP 50 EP 56 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BP88C UT WOS:000086475500007 ER PT S AU Thompson, A Datla, R Saunders, R Parr, A AF Thompson, A Datla, R Saunders, R Parr, A BE ElGenk, MS TI International Space Station utilization for radiometric calibration support to earth remote sensing programs SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2000) CY JAN 30-FEB 03, 2000 CL ALBUQUERQUE, NM SP Boeing Co, Lockheed Martin Corp, NASA, US DOE, Sandia Natl Lab, Los Almos Natl Lab, Amer Astronaut Soc, Amer Inst Chem Engineers, Div Heat Transfer & Energy Convers, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer inst Aeronaut & Astronaut, Local Sect, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Div Nucl Engn, Amer Soc Mech Engineers, Div Heat Transfer, Inst Elect & Electr Engineers Inc, Nucl & Plasma Sci Soc, Int Astronaut Federat, NASA, Natl Space Grant Coll & Fellowship Program, New Mexico Space grant Consortium ID NEAR-INFRARED CHANNELS; ABSOLUTE CALIBRATION; TEMPERATURE TRENDS; IN-FLIGHT; SATELLITE; SURFACE; SENSORS; SERIES; MSU AB The idea of utilizing the International Space Station (ISS) to provide a platform for manned and maintained NIST/SI traceable standard sensors in the visible, infrared, and microwave spectral regions to augment the spectral calibration of other remote sensing sensors is being well received in the calibration community. Review of the current state of the art in solar monitoring as evidenced by intercomparison between different satellite sensors for total solar irradiance, solar spectral irradiance and measured spectral irradiance versus reference spectra very much proves this point. Analysis of the Microwave Sounding Unit (MSU) radiometer data to deduce global temperature trends also shows the dire need for a better calibration of these instruments flown on sequential satellites to a very high degree of accuracy. In this regard possible radiometric calibration missions on ISS as envisioned by NIST will be discussed. Also the current plan for a feasibility study for these missions on ISS that address issues such as ISS platform dynamics and contamination levels and effects will be discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Thompson, A (reprint author), Natl Inst Stand & Technol, 100 Bur Dr Stop 8442, Gaithersburg, MD 20899 USA. NR 22 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 1-56396-919-X J9 AIP CONF PROC PY 2000 VL 504 BP 429 EP 434 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BP88C UT WOS:000086475500070 ER PT S AU Heavner, TP Hollberg, LW Jefferts, SR Kitching, J Meekhof, DM Parker, TE Phillips, WD Rolston, SL Robinson, HG Shirley, JH Sullivan, DB Walls, FL Ashby, N Klipstein, WM Maleki, L Seidel, DJ Thompson, RJ Wu, S Young, L Vessot, RFC DeMarchi, A AF Heavner, TP Hollberg, LW Jefferts, SR Kitching, J Meekhof, DM Parker, TE Phillips, WD Rolston, SL Robinson, HG Shirley, JH Sullivan, DB Walls, FL Ashby, N Klipstein, WM Maleki, L Seidel, DJ Thompson, RJ Wu, S Young, L Vessot, RFC DeMarchi, A BE ElGenk, MS TI A laser-cooled atomic clock in space SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2000) CY JAN 30-FEB 03, 2000 CL ALBUQUERQUE, NM SP Boeing Co, Lockheed Martin Corp, NASA, US DOE, Sandia Natl Lab, Los Almos Natl Lab, Amer Astronaut Soc, Amer Inst Chem Engineers, Div Heat Transfer & Energy Convers, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer inst Aeronaut & Astronaut, Local Sect, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Div Nucl Engn, Amer Soc Mech Engineers, Div Heat Transfer, Inst Elect & Electr Engineers Inc, Nucl & Plasma Sci Soc, Int Astronaut Federat, NASA, Natl Space Grant Coll & Fellowship Program, New Mexico Space grant Consortium AB This paper describes work aimed at producing a "Primary Atomic Reference Clock in Space (PARCS)," scheduled for flight on the International Space Station in 2004. The microgravity environment of space will allow this clock to achieve an uncertainty ten times lower than can be achieved on earth. The experimental objectives are to measure several relativistic effects on clocks and to provide both time and frequency references available as a international standards accessible to anyone on earth. C1 Natl Inst Stand & Technol, Boulder, CO 80304 USA. RP Heavner, TP (reprint author), Natl Inst Stand & Technol, Boulder, CO 80304 USA. EM donald.sullivan@nist.gov RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 6 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-919-X J9 AIP CONF PROC PY 2000 VL 504 BP 691 EP 694 PG 4 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BP88C UT WOS:000086475500119 ER PT S AU Wilkinson, DC Shea, MA Smart, DF AF Wilkinson, DC Shea, MA Smart, DF BE Rostoker, G TI A case history of solar and galactic space weather effects on the geosynchronous communications satellite TDRS-1 SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron ID UPSETS AB Energetic particles of both galactic and solar origin have the potential to cause state changes in memory devices used on-board spacecraft. The particular memory device used in the attitude control system of the Tracking and Data Relay System (TDRS-1) lends itself to the study of this phenomena due to its high susceptibility to such upsets. An eight-year record of TDRS-1 on-orbit upsets reflect the solar cycle variation in galactic radiation as well as radiation enhancements due to solar events. The proton and alpha particle data from the GOES space environment monitor are used to illustrate the radiation environment responsible for these upsets. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. USAF, Res Lab, VSBS, Bedford, MA 01731 USA. RP Wilkinson, DC (reprint author), NOAA, Natl Geophys Data Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 1 BP 27 EP 30 DI 10.1016/S0273-1177(99)01022-4 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000004 ER PT S AU Obara, T Nagatsuma, T Den, M Sagawa, E Onsager, TG AF Obara, T Nagatsuma, T Den, M Sagawa, E Onsager, TG BE Rostoker, G TI Effects of the IMF and substorms on the rapid enhancement of relativistic electrons in the outer radiation belt during storm recovery phase SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Review CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron ID INTERPLANETARY AB It is often the case that the flux of the relativistic electrons in the outer radiation belt decreases substantially once the major magnetic storm takes place. After the disappearance of the relativistic electrons which can last as much as one day, an increase in the flux occurs, often to levels that exceed the pre-storm level. We have investigated a correlation of the increment of the relativistic electron flux at geosynchronous orbit with the interplanetary magnetic field (IMF) properties as well as the magnetic disturbance signature during the magnetic storms. Results demonstrate that a large flux enhancement occurs when the IMF is southward during the storm recovery phase. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Hiraiso Solar Terr Res Ctr, CRL, Hitachinaka, Ibaraki 3111202, Japan. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Obara, T (reprint author), Hiraiso Solar Terr Res Ctr, CRL, 3601 Isozaki, Hitachinaka, Ibaraki 3111202, Japan. OI Nagatsuma, Tsutomu/0000-0002-9334-0738 NR 10 TC 9 Z9 9 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2000 VL 26 IS 1 BP 89 EP 92 DI 10.1016/S0273-1177(99)01030-3 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000012 ER PT S AU Friedel, RHW Reeves, G Belian, D Cayton, T Mouikis, C Korth, A Blake, B Fennell, J Selesnick, R Baker, D Onsager, T Kanekal, S AF Friedel, RHW Reeves, G Belian, D Cayton, T Mouikis, C Korth, A Blake, B Fennell, J Selesnick, R Baker, D Onsager, T Kanekal, S BE Rostoker, G TI A multi-spacecraft synthesis of relativistic electrons in the inner magnetosphere using LANL, GOES, GPS, SAMPEX, HEO and polar SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron ID RADIATION BELT; PARTICLE; SOLAR AB One of the Brussels Radiation Belt Workshop recommendations was the establishment of a near-real-time data driven model of the inner magnetospheric energetic particle population (L < 8). Although the "ideal" missions and data sets for such a model do not exist at present, more spacecraft than ever before are currently sampling the inner magnetosphere. We attempt here in a case study of the January 10, 1997 magnetic cloud event to construct such a model with the energetic electron data available from 5 geosynchronous and 5 elliptically orbiting satellites. We examine the constraints and difficulties of putting together a large number of datasets which are measured near-simultaneously at very different locations in the inner magnetosphere. First results indicate that we can achieve a time resolution of about 3 hours for a given "snapshot" of the inner magnetosphere, and that large azimuthal asymmetries of the energetic electron population can be observed during large storms. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Max Planck Inst Aeron, Katlenburg Lindau, Germany. Aerospace Corp, El Segundo, CA 90245 USA. LASP, Boulder, CO USA. NOAA, SEC, Boulder, CO USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Friedel, RHW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Friedel, Reiner/D-1410-2012; Reeves, Geoffrey/E-8101-2011 OI Friedel, Reiner/0000-0002-5228-0281; Reeves, Geoffrey/0000-0002-7985-8098 NR 12 TC 10 Z9 12 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 1 BP 93 EP 98 DI 10.1016/S0273-1177(99)01031-5 PG 6 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000013 ER PT J AU Barker, CH Galt, JA AF Barker, CH Galt, JA TI Analysis of methods used in spill response planning: Trajectory analysis planner TAP II SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Article; Proceedings Paper CT 3rd International Marine Environmental Modelling Seminar CY MAR, 1999 CL LILLEHAMMER, NORWAY DE oil spill response; oil spill planning; oil spill trajectories; statistics AB Long records of geophysical forcing have been used in numerous studies to estimate a statistical distribution of oil spill scenarios. The resulting set of spill scenarios is then used as a basis for planning a robust response capability that should be able to handle all likely real spills. For model developers to be able to support these expectations there are a number of criteria that must be satisfied: (1) Models must develop and retain the data necessary to answer key response questions; (2) developers must understand the limitations in resolution imposed by the specific algorithms they use; and (3) the cardinality of the long geophysical records (with respect to modeled spill behavior) should be determined and the final collection of spill scenarios must span this set. This paper considers these specific constraints and discusses methods that can be used to quantify some aspects of the uncertainty in the output. Published by Elsevier Science Ltd. C1 NOAA, Off Response & Restorat, Hazardous Mat Response & Assessment Div, Seattle, WA 98115 USA. RP Barker, CH (reprint author), NOAA, Off Response & Restorat, Hazardous Mat Response & Assessment Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 4 TC 8 Z9 8 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1353-2561 J9 SPILL SCI TECHNOL B JI Spill Sci. Technol. Bull. PY 2000 VL 6 IS 2 BP 145 EP 152 DI 10.1016/S1353-2561(00)00041-4 PG 8 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 348DN UT WOS:000088970100006 ER PT J AU Lehr, WJ AF Lehr, WJ TI Langmuir circulation and oil spills: A tale of two tribes - Preface SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Editorial Material C1 NOAA, HAZMAT, Seattle, WA 98115 USA. RP Lehr, WJ (reprint author), NOAA, HAZMAT, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1353-2561 J9 SPILL SCI TECHNOL B JI Spill Sci. Technol. Bull. PY 2000 VL 6 IS 3-4 BP 207 EP 207 DI 10.1016/S1353-2561(01)00038-X PG 1 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 423GK UT WOS:000168166900001 ER PT J AU Lehr, WJ Simecek-Beatty, D AF Lehr, WJ Simecek-Beatty, D TI The relation of Langmuir circulation processes to the standard oil spill spreading, dispersion, and transport algorithms SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Article DE Langmuir; oil spill; oil slick ID BREAKING WAVES; FLOATING PARTICLES; STATISTICS; BUBBLES AB Most standard oil spill modeling programs neglect the effects of Langmuir circulation (LC), The authors have identified three areas where LC effects may be important in spill behavior. These three areas are spreading, dispersion, and transport, LC will cause the slick to break into windrows when the wind-row formation velocity is comparable to Fay and other spreading forces. Oil dispersion is likely to be enhanced, with droplets carried to greater depth and distributed non-uniformly. Transport velocities for different parts of the slick will vary because of LC, a phenomenon that also occurs because of other factors. (C) 2001 Published by Elsevier Science Ltd. C1 NOAA, HAZMAT, Seattle, WA 98115 USA. RP Lehr, WJ (reprint author), NOAA, HAZMAT, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 32 TC 15 Z9 16 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1353-2561 J9 SPILL SCI TECHNOL B JI Spill Sci. Technol. Bull. PY 2000 VL 6 IS 3-4 BP 247 EP 253 PG 7 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 423GK UT WOS:000168166900006 ER PT J AU Simecek-Beatty, D Lehr, WJ AF Simecek-Beatty, D Lehr, WJ TI Langmuir circulation and oil spill trajectory models workshop - Comments and recommendations SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Article ID DISPERSION C1 NOAA, HAZMAT, Hazardous Mat Response Div, Seattle, WA 98115 USA. RP Simecek-Beatty, D (reprint author), NOAA, HAZMAT, Hazardous Mat Response Div, Seattle, WA 98115 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1353-2561 J9 SPILL SCI TECHNOL B JI Spill Sci. Technol. Bull. PY 2000 VL 6 IS 3-4 BP 273 EP 274 DI 10.1016/S1353-2561(01)00046-9 PG 2 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 423GK UT WOS:000168166900009 ER PT J AU Simecek-Beatty, D Overstreet, R AF Simecek-Beatty, D Overstreet, R TI More about Langmuir circulation and oil spill modeling - A bibliography SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Bibliography C1 NOAA, Hazardous Mat Response Div, Seattle, WA 98115 USA. RP Simecek-Beatty, D (reprint author), NOAA, Hazardous Mat Response Div, Seattle, WA 98115 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1353-2561 J9 SPILL SCI TECHNOL B JI Spill Sci. Technol. Bull. PY 2000 VL 6 IS 3-4 BP 275 EP 279 PG 5 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 423GK UT WOS:000168166900010 ER PT S AU Gillaspy, JD AF Gillaspy, JD BE Hilborn, RC Tino, GM TI High precision experimental tests of the symmetrization postulate for fermions SO SPIN-STATISTICS CONNECTION AND COMMUTATION RELATIONS: EXPERIMENTAL TESTS AND THEORETICAL IMPLICATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Spin-Statistics Connection and Commutation Relations CY MAY 31-JUN 03, 2000 CL ANACAPRI, ITALY SP Int Advisory Comm, Local Organizing Comm, Univ Napoli, Ctr Int Cultura Sci, Univ Napoli, Fed Dipartimento Sci Fis, Ist Italiano Studi Filosofci, Ist Nazl Fis Nucl, Ist Nazl Fis Materia, CNR Grp Nazl Struttura Materia ID PAULI EXCLUSION-PRINCIPLE; SMALL VIOLATIONS; ATOMIC ELECTRONS; SEARCH; TRANSITIONS; STATISTICS; NUCLEONS; LIMITS; HELIUM AB A review is given of experiments that have been used to infer an upper bound on the degree (beta (2)) to which the symmetrization postulate might be violated in nature. A proposed grouping of the experiments into seven different categories is put forth, based on different conceptual difficulties associated with interpreting them. Some comments are made about the strengths and weaknesses of representative experiments from several of the categories. It is suggested that there may be a considerable body of existing experimental data that could be analyzed to infer additional limits on SP-violation; as an example of this 1 consider the suppression of molecular recombination in spin-polarized atomic hydrogen by strong magnetic fields. While this article is limited to experiments involving fermions, an extensive bibliography on both theory and experiments related to the spin-statistics connection in general is referred to. C1 NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Gillaspy, JD (reprint author), NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. NR 33 TC 3 Z9 3 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 1-56396-974-2 J9 AIP CONF PROC PY 2000 VL 545 BP 241 EP 252 PG 12 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Particles & Fields; Physics, Mathematical SC Physics GA BR39N UT WOS:000166298600026 ER PT S AU Roberts, JW Slattery, OT AF Roberts, JW Slattery, OT BE Merritt, JO Benton, SA Woods, AJ Bolas, MT TI Display characteristics and the impact on usability for stereo SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS VII 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 VII CY JAN 24-27, 2000 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE AB Over the past decade, the number of electronic display technologies available. to consumers has risen dramatically, and the capabilities of existing technologies have been expanded. This proliferation of choices provides new opportunities for visual stereo presentation, but also new challenges. The methods of implementing stereo on an electronic display, optimized for the original capabilities of the original displays, may no longer be the best choices. Features such as response time, frame rate; aspect ratio, syne timing pixel registration, and temporal modulation of grayscale (rightness) and color can strongly influence the process of selecting an optimum presentation format for a given display technology. Display perfomance issues such as brightness, contrast, flicker, image distortion, defective pixels, and mura are more critical in 3D imagery than in 2D. Susceptibility to burn-in limits the implementation choices for a display that is to be used for both 3D and 2D applications. Resolution and frame rate establish the overall capability for representing depth, and also establish the performance requirements for the engine providing the 3D material. This paper surveys the capabilities and characteristics of traditional displays such as CRT and LCD panel, and a broad assortment of newer display technologies, including color plasma, field emission, micromirror and other reflective systems, and the general classes of microdisplays. Relevance of display characteristics to various stereo presentation formats is discussed, with description of laboratory experimentation to provide hard numbers. Recommendations are made regarding the stereo formats to be used with various display technologies, and the display technologies to be used with various stereo formats. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Roberts, JW (reprint author), Natl Inst Stand & Technol, MS 8951, Gaithersburg, MD 20899 USA. NR 6 TC 9 Z9 9 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 0-8194-3575-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3957 BP 128 EP 137 DI 10.1117/12.384436 PG 10 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BQ35Z UT WOS:000088119500014 ER PT S AU Simiu, E AF Simiu, E BE Broomhead, DS Luchinskaya, EA McClintock, PVE Mullin, T TI A unified theory of deterministic and noise-induced transitions: Melnikov processes and their application in engineering, physics and neuroscience SO STOCHASTIC AND CHAOTIC DYNAMICS IN THE LAKES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Stochastic and Chaotic Dynamics in the Lakes CY AUG, 1999 CL AMBLESIDE, ENGLAND ID CHAOTIC DYNAMICS APPROACH; SYSTEMS AB For a class of deterministic systems chaotic dynamics entails irregular transitions between motions within a potential well (librations) and motions across a potential barrier (rotations). The necessary condition for the occurrence of chaos - and transitions - is that the system's Melnikov function have simple zeros. The behavior of those systems' stochastic counterparts, including their chaotic behavior, is similarly characterized by their Melnikov processes. The application of the Melnikov method shows that deterministic and stochastic excitations play similar roles in the promotion of chaos, meaning that stochastic systems exhibiting transitions between librations and rotations have chaotic behavior, including sensitivity to initial conditions, just like their deterministic counterparts. We briefly review the Melnikov method and its use to obtain: criteria guaranteeing the non-occurrence of transitions in systems excited by bounded processes; upper bounds for the probability that transitions can occur during a specified time interval in systems excited by unbounded processes; and assessments of the influence of the excitation's spectral density on the transition rate. We also briefly review applications of Melnikov processes. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Simiu, E (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 8 TC 1 Z9 1 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 1-56396-915-7 J9 AIP CONF PROC PY 2000 VL 502 BP 266 EP 271 PG 6 WC Mathematics, Applied; Physics, Multidisciplinary SC Mathematics; Physics GA BP75Z UT WOS:000086079200037 ER PT S AU Scott, JHJ Windsor, ES AF Scott, JHJ Windsor, ES BE Buchanan, DA Edwards, AH VonBardeleben, HJ Hattori, T TI Chemical and structural characterization of ultrathin dielectric films using AEM SO STRUCTURE AND ELECTRONIC PROPERTIES OF ULTRATHIN DIELECTRIC FILMS ON SILICON AND RELATED STRUCTURES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Structure and Electronic Properties of Ultrathin Dielectric Films on Silicon and Related Structures at the 1999 MRS Fall Meeting CY NOV 29-DEC 01, 1999 CL BOSTON, MA SP Mat Res Soc AB The structure of ultrathin silicon oxynitride films, used as gate dielectrics in integrated circuits (ICs), is studied using analytical electron microscopy (AEM). Laterally homogeneous blanket films approximately 2 nm in thickness are characterized in cross section using a 300 keV field emission TEM/STEM. High resolution imaging (HRTEM) is used to investigate the accuracy and precision of film thickness measurements and their comparability to other techniques such as secondary ion mass spectrometry, spectroscopic ellipsometry, x-ray reflectivity, x-ray photoelectron spectroscopy, and medium energy ion scattering. A two dimensional magnification calibration scheme that fits a pair of basis vectors to experimental images is presented, and integrated intensity profiles are used to define film boundaries for measurement. These image processing tools simultaneously improve the repeatability of the measurements and remove subjective operator bias from the measurement process. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Scott, JHJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-500-5 J9 MATER RES SOC SYMP P PY 2000 VL 592 BP 153 EP 158 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied SC Engineering; Materials Science; Physics GA BR35U UT WOS:000166183800023 ER PT S AU Sengers, JMHL AF Sengers, JMHL BE Kiran, E Debenedetti, PG Peters, CJ TI Supercritical fluids: Their properties and applications SO SUPERCRITICAL FLUIDS: FUNDAMENTALS AND APPLICATIONS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES LA English DT Proceedings Paper CT Conference of the NATO-Advanced-Study-Institute on Supercritical Fluids CY JUL 12-24, 1998 CL KEMER, TURKEY SP NATO ID PRESSURES; TEMPERATURE; EQUATION; REGION; POINT; STATE C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Sengers, JMHL (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. EM johanna.sengers@nist.gov NR 27 TC 17 Z9 17 U1 2 U2 6 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-132X BN 0-7923-6235-7 J9 NATO ADV SCI I E-APP PY 2000 VL 366 BP 1 EP 29 PG 29 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA BR46S UT WOS:000166546300001 ER PT S AU Shaw, PS Lykke, KR Gupta, R Arp, U Lucatorto, TB Parr, AC AF Shaw, PS Lykke, KR Gupta, R Arp, U Lucatorto, TB Parr, AC BE Pianetta, P Arthur, J Brennan, S TI The new UV radiometry facility at SURF SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th US National Conference on Synchrotron Radiation Instrumentation CY OCT 13-15, 1999 CL STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA HO STANFORD SYNCHROTRON RADIAT LAB ID SYNCHROTRON-RADIATION; BESSY AB The Synchrotron Ultraviolet Radiation Facility (SURF III) at the National Institute of Standards and Technology (NIST) provides a unique opportunity for high-accuracy vacuum ultraviolet (VUV) to visible radiometry with the completion of a recent upgrade to improve the uniformity of the magnetic field along the electron trajectory. In response to the rapid development from the semiconductor industry to astrophysics instrumentation, the major goal for UV radiometry at SURF III includes improving the UV radiometric standard of the nation for detector calibration and a national standard UV light source for source intercomparison. To further enhance the existing radiometric program at SURF III, two more beamlines (beamlines 3 and 4) are now dedicated for radiometry from the VUV to the visible range. The major component of beamline 4 is an Absolute Cryogenic Radiometer, which measures the incident radiation by an electrical substitution method. The beamline provides a facility for UV detector calibration and research in UV detector radiation damage, detector surface reflectivity, and determination of UV material optical constants. We are also constructing beamline 3 that will use SURF as an accurate standard light source to improve the UV scale of other conventional light sources. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Shaw, PS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 1 Z9 1 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 1-56396-941-6 J9 AIP CONF PROC PY 2000 VL 521 BP 81 EP 86 PG 6 WC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy SC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy GA BQ56A UT WOS:000088762600014 ER PT S AU Furst, ML Arp, U Cauchon, GP Graves, RM Hamilton, AD Hughey, LR Lucatorto, TB Tarrio, C AF Furst, ML Arp, U Cauchon, GP Graves, RM Hamilton, AD Hughey, LR Lucatorto, TB Tarrio, C BE Pianetta, P Arthur, J Brennan, S TI Selected programs at the new SURF III electron storage ring SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th US National Conference on Synchrotron Radiation Instrumentation CY OCT 13-15, 1999 CL STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA HO STANFORD SYNCHROTRON RADIAT LAB ID EXTREME-ULTRAVIOLET; SYNCHROTRON AB The conversion of the electron storage ring at NIST (the National Institute of Standards and Technology) to SURF III (the Synchrotron Ultraviolet Radiation Facility) has resulted in a significant improvement to the azimuthal uniformity of the magnetic field as well as the capability for operating at higher beam energies. Measurements of magnetic field strength revealed azimuthal uniformity of better than +/- 0.05% at field strengths equivalent to operating energies of 52 MeV to 417 MeV. Initial operation is restricted to energies up to 331 MeV due to temporary limitations in the rf transmission system. Even at 331 MeV there is already a significant extension of the usable short wavelength range of the synchrotron radiation as compared to the range available at the 284 MeV operating energy of SURF II. These and other improvements have a major impact on SURF programs including: the Nanodetector, a conversion microscope which is a prototype real-time imaging system for EUV (extreme ultraviolet) lithography; the Spectrometer Calibration Beamline, used for high-accuracy absolute calibration of spectrometers; and the National EUV Reflectometry Facility, used to measure optical constants of thin-film multilayer optics. C1 Natl Inst Stand & Technol, Electron Opt Phys Div, Gaithersburg, MD 20899 USA. RP Furst, ML (reprint author), Natl Inst Stand & Technol, Electron Opt Phys Div, 100 Bur Dr,Stop 8411, Gaithersburg, MD 20899 USA. NR 7 TC 3 Z9 3 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 1-56396-941-6 J9 AIP CONF PROC PY 2000 VL 521 BP 87 EP 90 PG 4 WC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy SC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy GA BQ56A UT WOS:000088762600015 ER PT S AU Vest, RE Canfield, LR AF Vest, RE Canfield, LR BE Pianetta, P Arthur, J Brennan, S TI New developments for the extreme ultraviolet detector radiometry beamline at SURF III SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th US National Conference on Synchrotron Radiation Instrumentation CY OCT 13-15, 1999 CL STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA HO STANFORD SYNCHROTRON RADIAT LAB AB The upgrade of the SURF electron storage ring has provided an opportunity to make several improvements to the detector radiometry beamline (BL-9). A new control and data acquisition system has been developed and new high-order-suppression filters have been installed. Fundamental beamline characterizations have been made to evaluate the impact of the upgraded synchrotron radiation source on the calibration of NIST transfer standard photodiodes. C1 Natl Inst Stand & Technol, Electron & Opt Phys Div, US Dept Commerce, Technol Adm, Gaithersburg, MD 20899 USA. RP Vest, RE (reprint author), Natl Inst Stand & Technol, Electron & Opt Phys Div, US Dept Commerce, Technol Adm, Gaithersburg, MD 20899 USA. NR 2 TC 4 Z9 4 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 1-56396-941-6 J9 AIP CONF PROC PY 2000 VL 521 BP 104 EP 107 PG 4 WC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy SC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy GA BQ56A UT WOS:000088762600019 ER PT S AU Long, GG Allen, AJ Ilavsky, J Jemian, PR Zschack, P AF Long, GG Allen, AJ Ilavsky, J Jemian, PR Zschack, P BE Pianetta, P Arthur, J Brennan, S TI The ultra-small-angle x-ray scattering instrument on UNICAT at the APS SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th US National Conference on Synchrotron Radiation Instrumentation CY OCT 13-15, 1999 CL STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA HO STANFORD SYNCHROTRON RADIAT LAB ID CAMERA AB A new ultra-small-angle X-ray scattering (USAXS) instrument has been commissioned as part of the UNICAT facility on the 33-ID line at the Advanced Photon Source. The instrument offers continuously-tunable optics for anomalous USAXS, 1000 times the throughput of earlier USAXS instruments(1,2), high sensitivity and high resolution at low scattering vector, and a scattering vector range from below 0.00015 Angstrom(-1) to above 0.5 Angstrom(-1). Early results include USAXS from colloidal silica suspensions, and anomalous USAXS from rare- earth oxides in the presence of similarly-sized cavities in silicon nitride. The addition of side-reflection optics, in an optional configuration of this instrument, enables USAXS measurements of anisotropic as well as isotropic materials. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Long, GG (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI USAXS, APS/D-4198-2013 NR 8 TC 26 Z9 26 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-941-6 J9 AIP CONF PROC PY 2000 VL 521 BP 183 EP 187 PG 5 WC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy SC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy GA BQ56A UT WOS:000088762600034 ER PT S AU Bosch, RA Eisert, DE Furst, ML Graves, RM Greenler, L Hamilton, A Hughey, LR Madden, RP Robl, P Shaw, PS Trzeciak, WS Vest, RE Wahl, D AF Bosch, RA Eisert, DE Furst, ML Graves, RM Greenler, L Hamilton, A Hughey, LR Madden, RP Robl, P Shaw, PS Trzeciak, WS Vest, RE Wahl, D BE Pianetta, P Arthur, J Brennan, S TI SURF III - A new electron storage ring at NIST SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th US National Conference on Synchrotron Radiation Instrumentation CY OCT 13-15, 1999 CL STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA HO STANFORD SYNCHROTRON RADIAT LAB AB The National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS), has operated the Synchrotron Ultraviolet Radiation Facility (SURF), based on an electron accelerator, continuously since the early 1960s. SURF I was established in 1961, utilizing a 180 MeV electron synchrotron at NBS in Washington, D.C This accelerator was moved to the Gaithersburg, MD site in 1968, specifically for the continuation of SURF I operations. It was converted to an electron storage ring, SURF II, in 1974 under contract with the Physical Sciences Laboratory (PSL) at the University of Wisconsin-Madison (UW), and became a national standard of irradiance in the UV and VUV spectral region. To improve its performance in this application and broaden its spectral range, SURF II. has been converted to SURF III, commissioned in December 1998. The design and construction of the new system were overseen by PSL and the Synchrotron Radiation Center at UW. SURF III remains a weak-focusing, single-magnet storage ring with a circular orbit. However the original 140 ton (1.25 MN) laminated iron core magnet has been replaced with one having a 200 ton (1.78 MN) solid iron core of revised geometry, allowing operation over an energy range of 100 MeV - 400 MeV. The magnet system design was optimized using both 2-D and 3-D calculations. The predicted circumferential field uniformity of the order of 2 parts in 10(4), a factor of 40 improvement, was confirmed experimentally over the electron energy range of anticipated radiometric applications. The storage ring vacuum system has been updated, two more radiation ports have been added, and the control system has been modernized. The exceptional magnetic field uniformity in this machine is already giving rise to interesting beam dynamical effects. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. RP Bosch, RA (reprint author), Natl Inst Stand & Technol, Phys Lab, 100 Bur Dr,Stop 8411, Gaithersburg, MD 20899 USA. NR 2 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-941-6 J9 AIP CONF PROC PY 2000 VL 521 BP 383 EP 390 PG 8 WC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy SC Instruments & Instrumentation; Microscopy; Optics; Spectroscopy GA BQ56A UT WOS:000088762600071 ER PT J AU Barros, V Gonzalez, M Liebmann, B Camilloni, I AF Barros, V Gonzalez, M Liebmann, B Camilloni, I TI Influence of the South Atlantic convergence zone and South Atlantic Sea surface temperature on interannual summer rainfall variability in Southeastern South America SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article ID CIRCULATION; OSCILLATION; BRAZIL AB In subtropical Argentina, Paraguay and southern Brazil, precipitation is most abundant during summer but its interannual variability is large. At this time a zone of low-level convergence, upper-level divergence, and intense convection is developed to the north of this area. This feature is known as the South Atlantic convergence zone (SACZ) and seems to be related to the interannual variability of summer rainfall to its south. The aim of this work is to document this relationship. Reduced (increased) precipitation in southern Brazil, most of Uruguay and northeastern Argentina is associated with a strong (weak) SACZ and a northward (southward) displacement of it, while increased (reduced) rainfall occurs further south in subtropical Argentina. Also, warm (cold) SST in the region 20 degrees S-40 degrees S and west of 30 degrees W is likely accompanied by a southward (northward) shift of the SACZ. Aside of this relation with the SACZ that affect on the precipitation field of Southeastern South America, the proximate Atlantic Ocean SST seems to force the precipitation over this region by other mechanisms as well. The result of this additional SST forcing is to enhance the signal of the SACZ in northeastern Argentina, Uruguay and southern Brazil and to oppose the SACZ effect in southern subtropical Argentina. C1 Univ Buenos Aires, Dept Atmospher Sci, RA-1428 Buenos Aires, DF, Argentina. Univ Colorado, NOAA, Climate Diagnost Ctr, Boulder, CO 80309 USA. Univ Buenos Aires, CONICET, CIMA, Ctr Invest Mar & Atmosfera, RA-1053 Buenos Aires, DF, Argentina. RP Barros, V (reprint author), Univ Buenos Aires, Dept Atmospher Sci, 2 Piso Pabellon 2 Ciudad Univ, RA-1428 Buenos Aires, DF, Argentina. NR 16 TC 52 Z9 57 U1 0 U2 7 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-798X J9 THEOR APPL CLIMATOL JI Theor. Appl. Climatol. PY 2000 VL 67 IS 3-4 BP 123 EP 133 DI 10.1007/s007040070002 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 392CP UT WOS:000166393300002 ER PT S AU Slifka, AJ Filla, BJ Stalick, JK AF Slifka, AJ Filla, BJ Stalick, JK BE Uher, C Morelli, D TI Thermal conductivity of two compositions of yttria-stabilized zirconia SO THERMAL CONDUCTIVITY 25: THERMAL EXPANSION 13 SE THERMAL CONDUCTIVITY LA English DT Proceedings Paper CT 25th International Thermal Conductivity Conference/13th International Thermal Expansion Symposium CY JUN 13-16, 1999 CL UNIV MICHIGAN, ANN ARBOR, MI HO UNIV MICHIGAN ID BARRIER COATINGS; CERAMICS AB The thermal conductivities of two different compositions of yttria-stabilized zirconia have been measured using an absolute, steady-state method. The measurements were made in a one-sided guarded-hot-plate apparatus from 130 degreesC to 950 degreesC. One material has a predominantly tetragonal phase composition, and the other is predominantly cubic. The average measured values of thermal conductivity at 950 OC for the two compositions of yttria-stabilized zirconia are 2.8 Wm(-1)K(-1) and 2.3 Wm(-1)K(-1), respectively. The thermal conductivities of both compositions are nearly independent of temperature. The results show that both materials show promise as potential candidates for standard reference materials for high-temperature thermal conductivity. C1 NIST, Div Mat Reliabil, Boulder, CO 80303 USA. RP Slifka, AJ (reprint author), NIST, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0163-9005 BN 1-56676-806-3 J9 THERM COND PY 2000 VL 25 BP 147 EP 154 PG 8 WC Thermodynamics; Engineering, Chemical; Materials Science, Multidisciplinary SC Thermodynamics; Engineering; Materials Science GA BS16F UT WOS:000168892500017 ER PT S AU Zarr, RR Dalton, GR Fioravante, SM AF Zarr, RR Dalton, GR Fioravante, SM BE Uher, C Morelli, D TI Development of a NIST Standard Reference Database for thermal conductivity of building materials SO THERMAL CONDUCTIVITY 25: THERMAL EXPANSION 13 SE THERMAL CONDUCTIVITY LA English DT Proceedings Paper CT 25th International Thermal Conductivity Conference/13th International Thermal Expansion Symposium CY JUN 13-16, 1999 CL UNIV MICHIGAN, ANN ARBOR, MI HO UNIV MICHIGAN AB The development of a National Institute of Standards and Technolgy (NIST) Standard Reference Database for the thermal conductivity of building materials is presented. The source of the data is the collection of thermal conductivity measurements produced by NIST from 1932 to 1983 using the NIST 200 mm guarded-hot-plate apparatus. During its service, the apparatus was considered the U.S. National Standard for measurements of thermal conductivity of building materials and was instrumental in the early development of ASTM Test Method C 177 for the guarded-hot-plate method. The database currently contains 2175 records of thermal conductivity data for a variety of thermal insulations including cellular plastics, corkboard, glass fiber and other mineral fiber insulations as well as other building materials such as fiberboard and light-weight concrete. The final product will be available for public distribution on the Internet through the World Wide Web. C1 NIST, Gaithersburg, MD 20899 USA. RP Zarr, RR (reprint author), NIST, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 6 TC 1 Z9 1 U1 1 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0163-9005 BN 1-56676-806-3 J9 THERM COND PY 2000 VL 25 BP 259 EP 265 PG 7 WC Thermodynamics; Engineering, Chemical; Materials Science, Multidisciplinary SC Thermodynamics; Engineering; Materials Science GA BS16F UT WOS:000168892500029 ER PT B AU Didion, DA Brown, JS AF Didion, DA Brown, JS BE Bergles, AE Golobic, I TI Challenges in developing environmentally safe heat pumping systems SO THERMAL SCIENCES 2000 LA English DT 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 tote, 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 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Didion, DA (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZACIJE ENKRATNI ZALOZNISKO PI LJUBLJANA PA LJUBLJANA, SLOVENIA BN 961-6353-26-8 PY 2000 BP 57 EP 66 PG 10 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA BQ99T UT WOS:000165310800005 ER PT S AU Yoon, HW Davies, MA Burns, TJ Kennedy, MD AF Yoon, HW Davies, MA Burns, TJ Kennedy, MD BE Dinwiddie, RB LeMieux, DH TI Calibrated thermal microscopy of the tool-chip interface in machining SO THERMOSENSE XXII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thermosense XXII Conference CY APR 25-27, 2000 CL ORLANDO, FL SP SPIE DE thermal imaging; microscopy; calibration; machining; tool-chip interface AB A critical parameter in predicting tool wear during machining and in accurate computer simulations of machining is the spatially-resolved temperature at the tool-chip interface. We describe the development and the calibration of a nearly diffraction-limited thermal-imaging microscope to measure the spatially-resolved temperatures during the machining of an AISI 1045 steel with a tungsten-carbide tool bit. The microscope has a target area of 0.5 mm x 0.5 mm square region with a < 5 mu m spatial resolution and is based on a commercial InSb 128 x 128 focal plane array with an all reflective microscope objective. The minimum frame image acquisition time is < 1 ms. The microscope is calibrated using a standard blackbody source from the radiance temperature calibration laboratory at the National Institute of Standards and Technology, and the emissivity of the machined material is deduced from the infrared reflectivity measurements. The steady-state thermal images from the machining of 1045 steel are compared to previous determinations of tool temperatures from micro-hardness measurements and are found to be in agreement with those studies. The measured average chip temperatures are also in agreement with the temperature rise estimated from energy balance considerations. From these calculations and the agreement between the experimental and the calculated determinations of the emissivity of the 1045 steel, the standard uncertainty of the temperature measurements is estimated to be about 45 degrees C at 900 degrees C. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Yoon, HW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 16 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3646-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4020 BP 27 EP 37 DI 10.1117/12.381557 PG 11 WC Optics SC Optics GA BQ31Z UT WOS:000087919600004 ER PT S AU Stoudt, MR Cammarata, RC Ricker, RE AF Stoudt, MR Cammarata, RC Ricker, RE BE Vinci, R Kraft, O Moody, N Besser, P Shaffer, E TI Influence of nanometer-scale multilayered thin films on fatigue crack initiation SO THIN FILMS-STRESSES AND MECHANICAL PROPERTIES VIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium V on Thin Films-Stresses and Mechanical Properties VIII held at the 1999 MRS Fall Meeting CY NOV 29-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Adv Micro Devices Inc, AMIA Labs, Appl Mat Inc, Dow Chem Co, Hysitron Inc, IBM, T J Watson Res Ctr, Lucent Technol, Micron Syst Corp, Novellus Syst Inc, MTS Syst Corp, Seagate Technol Inc ID SURFACE; METALS AB The hypothesis that a thin nanometer-scale multilayered surface film could delay crack initiation and extend fatigue lives was evaluated by electrodepositing a Cu-Ni multilayer on Cu fatigue samples. A significant improvement in fatigue lives resulted and this improvement is attributed to properties of the multilayer coating. C1 NIST, Tech Adm, Div Met, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Stoudt, MR (reprint author), NIST, Tech Adm, Div Met, US Dept Commerce, Gaithersburg, MD 20899 USA. RI Cammarata, Robert /A-3307-2010; Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 12 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-502-1 J9 MATER RES SOC SYMP P PY 2000 VL 594 BP 15 EP 17 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA BR05C UT WOS:000165506400003 ER PT B AU Goens, DW Krumm, WR AF Goens, DW Krumm, WR GP AMS AMS TI Another look at the weather factors related to the 1949 Mann Gulch Fire SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Weather Serv, Missoula, MT 59803 USA. RP Goens, DW (reprint author), Natl Weather Serv, POB 9350, Missoula, MT 59803 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 1 EP 2 PG 2 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400001 ER PT B AU Page, EM Meyers, MP Chamberlain, M McAnelly, R AF Page, EM Meyers, MP Chamberlain, M McAnelly, R GP AMS AMS TI Operational use of mesoscale models in fire weather forecasting SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID RAMS C1 Natl Weather Serv, UCAR, COMET, Boulder, CO 80307 USA. RP Page, EM (reprint author), Natl Weather Serv, UCAR, COMET, POB 3000, Boulder, CO 80307 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 53 EP 54 PG 2 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400013 ER PT B AU Vasiloff, S AF Vasiloff, S GP AMS AMS TI Use of model soundings and real-time radar data to predict dry microbursts SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NOAA, ERL, NSSL, NWS,WR,SSD, Salt Lake City, UT 84138 USA. RP Vasiloff, S (reprint author), NOAA, ERL, NSSL, NWS,WR,SSD, WR Hq,125 S State St,Room 1210, Salt Lake City, UT 84138 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 2000 BP 72 EP 75 PG 4 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400020 ER PT B AU Bothwell, PD AF Bothwell, PD GP AMS AMS TI Forecasting dry thunderstorms as a part of fire weather outlooks at the Storm Prediction Center SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Storm Predict Ctr, Norman, OK 73069 USA. RP Bothwell, PD (reprint author), Storm Predict Ctr, 1313 Halley Circle, Norman, OK 73069 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 2000 BP 76 EP 79 PG 4 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400021 ER PT B AU Hoadley, JL AF Hoadley, JL GP AMS AMS TI Applications of AWIPS in fire weather forecasting SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Weather Serv, NOAA, Missoula, MT 59807 USA. RP Hoadley, JL (reprint author), Natl Weather Serv, NOAA, POB 9350, Missoula, MT 59807 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 2000 BP 90 EP 92 PG 3 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400024 ER PT B AU Bach, L Cacciola, A AF Bach, L Cacciola, A GP AMS AMS TI The Northeast Fire Danger Index System SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Natl Weather Serv, NOAA, Forecast Off, Albany, NY USA. RP Bach, L (reprint author), Natl Weather Serv, NOAA, Forecast Off, Suite B-300,251 Fuller Rd, Albany, NY 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 2000 BP 107 EP 110 PG 4 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400029 ER PT B AU Stoppkotte, JW AF Stoppkotte, JW GP AMS AMS TI The north central Nebraska prairie fire of 16 March 1999 SO THIRD SYMPOSIUM ON FIRE AND FOREST METEOROLOGY LA English DT Proceedings Paper CT 3rd Symposium on Fire and Forest Meteorology CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc AB What came to be the second largest wildfire on record for the state of Nebraska ripped through the sandhills of north central Nebraska during the afternoon and evening hours of Tuesday, 16 March 1999, with flare-ups continuing into the following day. By the evening of Wednesday, 17 March, nearly 72,000 acres of grassland had burned, numerous cattle perished, and one ranch house had burned. The meteorological setup was marked by gusty west winds at the surface, ahead of a cold front due to arrive in central Nebraska during the evening of 16 March. The National Weather Service (NWS) Warning Forecast Office (WFO) in North Platte played a vital role in the ultimate control of the fire by issuing timely spot forecasts. Forecasters at the WFO in North Platte were called on frequently to provide detailed forecasts primarily of wind direction and speed, which gusted at times, to near 50 mph after the cold frontal passage that occurred around 9 PM CST on 16 March. This paper will look at the meteorological events leading up to the fire, which started near an abandoned house close to the town of Mullen. as well as the use of the Advanced Weather Interactive Processing System (AWIPS) in making those forecasts. This will include a look at the passage of the cold front that changed the direction of fire spread, ultimately culminating in the evacuation of a small town in its path, during the early morning hours of 17 March 1999. C1 Natl Weather Serv Off, N Platte, NE 69101 USA. RP Stoppkotte, JW (reprint author), Natl Weather Serv Off, N Platte, NE 69101 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 2000 BP 120 EP 124 PG 5 WC Forestry; Meteorology & Atmospheric Sciences SC Forestry; Meteorology & Atmospheric Sciences GA BS01L UT WOS:000168322400034 ER PT S AU Holmes, GA Peterson, RC Hunston, DL McDonough, WG Schutte, CL AF Holmes, GA Peterson, RC Hunston, DL McDonough, WG Schutte, CL BE Schapery, RA Sun, CT TI The effect of nonlinear viscoelasticity on interfacial shear strength measurements SO TIME DEPENDENT AND NONLINEAR EFFECTS IN POLYMERS AND COMPOSITES SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Time Dependent and Nonlinear Effects inPolymers and Composites CY MAY 04-05, 1998 CL ATLANTA, GA SP Amer Soc Testing & Mat, Comm D-30 Composite Mat DE single-fiber fragmentation test; viscoelasticity; nonlinear matrix behavior; strain-rate dependence; interfacial shear strength; epoxy resin; E-glass fiber; Cox model; Kelly-Tyson model ID STRESS-DISTRIBUTION; MODEL COMPOSITES; EPOXY COMPOSITES; FIBER; SYSTEMS; FRAGMENTATION; MODULUS; MATRIX AB Experimental evidence demonstrates that diglycidyl ether of bisphenol-A (DGEBA)/meta phenylenediamine (m-PDA) epoxy wsin matrix used in the single fiber fragmentation tests exhibits nonlinear stress strain behavior in the region where E-glass fiber fracture occurs. rn addition, strain hardening after the onset of yield is observed. Therefore, linear elastic shear-lag models and the Kelly-Tyson model are inappropriate for the determination of the interfacial shear strength for this epoxy resin system. Using a strain-dependent Secant modulus in the Cox model, the calculated interfacial shear strength is shown to be relatively lower by at least 15% than the value determined using a linear elastic modulus. This decrease is consistent with numerical simulations which show the linear elastic approximation:over predicts the number of fragments in the fragmentation test. In addition, the value obtained by the strain-dependent secant modulus is approximately 300% relatively higher than the value predicted by the Kelly-Tyson model. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Holmes, GA (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 46 TC 9 Z9 9 U1 1 U2 2 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2601-8 J9 AM SOC TEST MATER PY 2000 VL 1357 BP 98 EP 117 DI 10.1520/STP15831S PG 20 WC Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BP76D UT WOS:000086082200006 ER PT J AU Teel, DJ Milner, GB Winans, GA Grant, WS AF Teel, DJ Milner, GB Winans, GA Grant, WS TI Genetic population structure and origin of life history types in chinook salmon in British Columbia, Canada SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID ONCORHYNCHUS-TSHAWYTSCHA; STOCK IDENTIFICATION; PACIFIC SALMON; STREAM-TYPE; OCEAN-TYPE; DNA VARIATION; COHO SALMON; NEW-ZEALAND; RIVER; PATTERNS AB We used protein electrophoresis to examine genetic population structure and origin of life history types of chinook salmon Oncorhynchus tshawytscha in British Columbia, Canada. Among 31 allozyme loci resolved in 91 samples from 63 populations of chinook salmon in rivers and hatcheries throughout British Columbia, population heterozygosities averaged 0.084 (range 0.048-0.108) and were typical of values for populations in other regions. A hierarchical gene diversity analysis indicated that 91.3% of the total allele-frequency diversity was attributable to within-population variability; the remaining 8.7% was attributable to geographic variability among populations, which was partitioned into among-river (3.3%), among-area (3.5%), and among-region (1.9%) components. Two major groups of populations appeared in the principal components analysis and in cluster analysis of genetic distances. A coastal group included populations in four subgroups: Central coast, Georgia Strait, lower Fraser River, and west Vancouver Island. An inland group included six subgroups: Nass River, Skeena River, north Thompson River, upper and mid-Fraser River, south Thompson River, and lower Thompson River. The geographic extents of the inland and coastal groups largely coincided with the geographic distributions of stream- and ocean-type juvenile forms and may reflect postglacial colonization by two ancestral lineages that survived in Pleistocene refugia. The presence of genetically undifferentiated stream-type fish in coastal streams populated by ocean-type fish may reflect either postglacial life history differentiation from ancestral ocean-type fish or life history flexibility of ocean-type fish. C1 NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. RP Teel, DJ (reprint author), NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 49 TC 37 Z9 38 U1 4 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 2000 VL 129 IS 1 BP 194 EP 209 DI 10.1577/1548-8659(2000)129<0194:GPSAOO>2.0.CO;2 PG 16 WC Fisheries SC Fisheries GA 349ZV UT WOS:000089076300016 ER PT J AU Ward, C Eshrenroder, RL Bence, JR AF Ward, C Eshrenroder, RL Bence, JR TI Relative abundance of lake trout and burbot in the main basin of Lake Michigan in the early 1930s SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID LAMPREY PETROMYZON-MARINUS; GREAT-LAKES; BATHYTHERMAL DISTRIBUTION; SUPERIOR; FISH; ONTARIO; GROWTH; WATERS AB We used general linear models to compare and to assess the sources of variation in CPUEs (catches per unit effort) of lake trout Salvelinus namaycush and burbot Lota lota netted in small-mesh gill nets from the main basin of Lake Michigan in the early 1930s, before populations of both species collapsed. Spring, summer, and fall CPUEs were modeled separately. In all seasons combined, CPUEs were over 2.5 times greater for lake trout than for burbot, and lake trout CPUEs were greater than burbot CPUEs in five of six regions of the lake. The hypothesized sources of variability in log(e)(CPUE) included lake region, depth (either as a linear [depth only] or a quadratic [depth and depth(2) included] relationship), number of nights out that the nets fished (also as either a linear or quadratic relationship), and the possibility that the effects of depth could vary among regions. The models predicted 57-68% of the variation in lake trout CPUE and 29-37% of the variation in burbot CPUE (log scales). Lake region was highly significant for both species in all seasons. In all seasons, the relationship between lake trout log(e)(CPUE) and depth was quadratic and varied among regions. For lake trout we did not find any effects of number of nights out. Burbot log(e)(CPUE) varied linearly with depth and with nights out in the spring. In the summer, log(e)(CPUE) for burbot varied linearly with nights out, and its relationship with depth was quadratic and varied among regions. In the fall, quadratic relationships between burbot log(e)(CPUE) and depth again differed among regions, but there was no relationship with nights out. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Michigan State Univ, Dept Fisheries & Wildlife, E Lansing, MI 48824 USA. RP Eshrenroder, RL (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd,Suite 209, Ann Arbor, MI 48105 USA. RI Bence, James/E-5057-2017 OI Bence, James/0000-0002-2534-688X NR 42 TC 5 Z9 7 U1 1 U2 6 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 2000 VL 129 IS 1 BP 282 EP 295 DI 10.1577/1548-8659(2000)129<0282:RAOLTA>2.0.CO;2 PG 14 WC Fisheries SC Fisheries GA 349ZV UT WOS:000089076300022 ER PT S AU Stafford, GR Jovic, VD Hussey, CL AF Stafford, GR Jovic, VD Hussey, CL BE Uskokovic, DP Battiston, GA Nedeljkovic, JM Milonjic, SK Rakovic, DI TI Electrodeposition of Cu-Al alloys and underpotential deposition of Al onto Cu single crystals from a room-temperature chloroaluminate molten salt SO TRENDS IN ADVANCED MATERIALS AND PROCESSES SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 3rd Yugoslov-Materials-Research-Society Conference CY SEP 20-24, 1999 CL HERCEG-NOVI, YUGOSLAVIA SP Fed Republic Yugoslavia, Minist Dev, Sci & Environm, Republic Serbia, Minist Sci & Technol, ZAMTES, Inst Inorgan Chem, Inorgan Technol & Adv Mat, Yugoslav Mat Res Soc DE Cu(100); Cu(110); Cu(111); Cu-Al alloys; electrodeposition; phase composition; room-temperature molten salt; UPD of Al ID COBALT-ALUMINUM ALLOYS; ELECTROCHEMISTRY; EQUILIBRIA; COPPER; MELT C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Mississippi, Dept Chem, University, MS 38677 USA. RP Stafford, GR (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 16 TC 5 Z9 7 U1 1 U2 5 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-859-1 J9 MATER SCI FORUM PY 2000 VL 352 BP 49 EP 55 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA BS04U UT WOS:000168448800007 ER PT S AU Jovic, BM Jovic, VD Stafford, GR AF Jovic, BM Jovic, VD Stafford, GR BE Uskokovic, DP Battiston, GA Nedeljkovic, JM Milonjic, SK Rakovic, DI TI Electrochemical formation and characterization of silver (I) oxide SO TRENDS IN ADVANCED MATERIALS AND PROCESSES SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 3rd Yugoslov-Materials-Research-Society Conference CY SEP 20-24, 1999 CL HERCEG-NOVI, YUGOSLAVIA SP Fed Republic Yugoslavia, Minist Dev, Sci & Environm, Republic Serbia, Minist Sci & Technol, ZAMTES, Inst Inorgan Chem, Inorgan Technol & Adv Mat, Yugoslav Mat Res Soc DE 3D nucleation; kinetics of Ag2O formation; morphology; precipitation ID POLYCRYSTALLINE SILVER; NUCLEATION; MECHANISM; KINETICS; GROWTH; RATES AB The kinetics of Ag2O formation has been investigated in 0.1M, 0.3M, 1M and 2M NaOH solutions on polycrystalline Ag electrodes by cyclic voltammetry and potentiostatic pulse techniques. It was shown that the concentration of NaOH plays an important role in the process of Ag2O formation. At high concentration of NaOH (greater than or equal to 1M) the process is not controlled by diffusion of reacting species and nucleation phenomenon is clearly detected on potentiostatic j-t transients. SEM micrographs of the chemically polished Ag surface and surface after the oxide formation reveals considerable roughening of the Ag surface after Ag2O formation and reduction. Two types of oxide morphology were detected by SEM. Glancing angle X-ray diffraction examination was found to be in good agreement with the SEM results. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Jovic, BM (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 17 TC 2 Z9 2 U1 1 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-859-1 J9 MATER SCI FORUM PY 2000 VL 352 BP 57 EP 63 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA BS04U UT WOS:000168448800008 ER PT J AU Ravikiran, A Low, TS AF Ravikiran, A Low, TS TI Nano-wear mechanism of amorphous carbon thin films SO TRIBOLOGY LETTERS LA English DT Article DE DLC; wear mechanism; thin films ID TRIBOLOGY AB Tribological performance of diamond-like carbon (DLC) overcoat on a magnetic hard disk was evaluated using a contact start stop wear tester. The analysis of worn surfaces suggests that wear of the carbon overcoat took place by a delamination type of wear mechanism at a nanoscale, resulting in the formation of wear particles of about 1.5 nm thick and 30-90 nm wide. C1 Natl Univ Singapore, Dept Elect Engn, Singapore 119260, Singapore. Natl Univ Singapore, Data Storage Inst, Singapore 119260, Singapore. RP Ravikiran, A (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2000 VL 8 IS 1 BP 41 EP 43 DI 10.1023/A:1019118714533 PG 3 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 300EZ UT WOS:000086241300006 ER PT B AU Ranganathan, M Bednarek, M Pors, F Montgomery, D AF Ranganathan, M Bednarek, M Pors, F Montgomery, D GP USENIX USENIX TI AGNI: A multi-threaded Middleware for distributed scripting SO USENIX ASSOCIATION PROCEEDINGS OF THE 7TH USENIX TCL/TK CONFERENCE (TCL/2K) LA English DT Proceedings Paper CT 7th Annual USENIX Tcl/Tk Conference CY FEB 14-18, 2000 CL AUSTIN, TX SP USENIX Assoc AB We present the design of a AGNI - a Tcl 8.1 based Middleware for building reactive, extensible, reconfigurable distributed systems, based upon an abstraction we call Mobile Streams. Using our system, a distributed, event-driven application can be scripted from a single point of control and dynamically extended and re-configured while it is in execution. Our system is suitable for building a wide variety of applications;for example, distributed test, conferencing and control-oriented applications. We illustrate the use of our system by presenting example applications. C1 NIST, Internetworking Technol Grp, Gaithersburg, MD 20899 USA. RP Ranganathan, M (reprint author), NIST, Internetworking Technol Grp, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 USA BN 1-880446-24-3 PY 2000 BP 11 EP 21 PG 11 WC Computer Science, Software Engineering SC Computer Science GA BP99W UT WOS:000086847100002 ER PT J AU Abdulaev, NG Ridge, KD AF Abdulaev, NG Ridge, KD TI Heterologous expression of bovine opsin in Pichia pastoris SO VERTEBRATE PHOTOTRANSDUCTION AND THE VISUAL CYCLE, PART A SE METHODS IN ENZYMOLOGY LA English DT Review ID FUNCTIONAL EXPRESSION; METHYLOTROPHIC YEAST; RHODOPSIN GENE; CELLS C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Maryland Biotechnol Inst, Rockville, MD 20850 USA. RP Abdulaev, NG (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. FU NEI NIH HHS [EY11112] NR 15 TC 5 Z9 5 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 2000 VL 315 BP 3 EP 11 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BQ69G UT WOS:000089206300001 PM 10736690 ER PT J AU Ridge, KD Abdulaev, NG AF Ridge, KD Abdulaev, NG TI Folding and assembly of rhodopsin from expressed fragments SO VERTEBRATE PHOTOTRANSDUCTION AND THE VISUAL CYCLE, PART A SE METHODS IN ENZYMOLOGY LA English DT Review ID BOVINE RHODOPSIN; MONOCLONAL-ANTIBODIES; POLYPEPTIDE FRAGMENTS; RETINITIS-PIGMENTOSA; GENE; PROTEIN; CELLS; BACTERIORHODOPSIN; RECONSTITUTION; RECEPTORS C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Maryland Biotechnol Inst, Rockville, MD 20850 USA. RP Ridge, KD (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. FU NEI NIH HHS [EY11112] NR 27 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 2000 VL 315 BP 59 EP 70 PG 12 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BQ69G UT WOS:000089206300004 PM 10736693 ER PT J AU Abdulaev, NG Kakuev, DL Ridge, KD AF Abdulaev, NG Kakuev, DL Ridge, KD TI Bovine retinal nucleoside diphosphate kinase: Biochemistry and molecular cloning SO VERTEBRATE PHOTOTRANSDUCTION AND THE VISUAL CYCLE, PT B SE METHODS IN ENZYMOLOGY LA English DT Review ID GUANYLATE KINASE; HUMAN-ERYTHROCYTES; OUTER SEGMENTS; PURIFICATION; EXPRESSION; RAT; DERIVATIVES; ENZYMES; GENE; ROD C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Maryland Biotechnol Inst, Rockville, MD 20850 USA. Russian Acad Sci, Shemyakin & Ovchinnikov Inst Bioorgan Chem, Moscow, Russia. RP Abdulaev, NG (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 22 TC 1 Z9 1 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 2000 VL 316 BP 87 EP 100 PG 14 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BQ22M UT WOS:000087601700006 PM 10800670 ER PT S AU Cugini, J Laskowski, S Sebrechts, M AF Cugini, J Laskowski, S Sebrechts, M BE Erbacher, RF Chen, PC Roberts, JC Wittenbrink, CM TI Design of 3-D visualization of search results: Evolution and evaluation SO VISUAL DATA EXPLORATION AND ANALYSIS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Meeting on Visual Data Exploration and Analysis CY JAN 24-26, 2000 CL SAN JOSE, CA SP SPIE, Soc Imaging & Technol DE comparison of 3-D and 2-D; design of visualization; evaluation of visualization; information visualization; usability experiment AB We discuss the evolution of the NIST Information Retrieval Visualization Engine (NIRVE), This prototype employs modern interactive visualization techniques to provide easier access to a set of documents resulting from a query to a search engine. The motivation and evaluation of several design features, such as keyword to concept mapping, explicit clustering, the use of 3-D vs. 2-D, and the relationship of visualization to logical structure are described. in particular, the results of an extensive usability experiment show how visualization may lead to either increased or decreased cognitive load. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cugini, J (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 17 TC 4 Z9 4 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 0-8194-3578-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 3960 BP 198 EP 210 DI 10.1117/12.378896 PG 13 WC Computer Science, Software Engineering SC Computer Science GA BP87X UT WOS:000086471500020 ER PT B AU Gangadean, D AF Gangadean, D BE Kane, DL TI Glacier-dammed lakes in Alaska SO WATER RESOURCES IN EXTREME ENVIRONMENTS, PROCEEDINGS SE AMERICAN WATER RESOURCES ASSOCIATION TECHNICAL PUBLICATION SERIES LA English DT Proceedings Paper CT AWRA 2000 Spring Specialty Conference on Water Resources in Extreme Environments CY MAY 01-03, 2000 CL AMER WATER RESOURCES ASSOC, ALASKA STATE SECT, ANCHORAGE, AK SP Amer Water Resources Assoc, Univ Alaska Fairbanks Water & Environm Res Ctr, Alaska Power & Tel Co, BP Explorat, GW Sci, Harza Engn Co, Meridian Management Inc, Montgomery Watson, Oasis Environm Inc, Remote Utilities Syst Grp HO AMER WATER RESOURCES ASSOC, ALASKA STATE SECT DE jokulhlaups; glacier-dammed lakes; glacier lake outbursts; Alaska glaciers AB Glacier dam lakes are hydrologic features that occur only in cold and wet environments that are conducive to glacial formation. Some of these lakes are created when a glacier encroaches on a tributary drainage and blocks the outlet. Runoff then starts to collect above the encroachment until a breach begins to form in the glacial ice and then the water is suddenly released. These jokulhlaup events occur repeatedly at locations where topography and climate permit. Typically the frequency of releases is about once a year. At some locations the subsequent wave released will achieve discharge rates that exceed the median annual maximum and cause flooding. This paper explores the factors necessary for glacier lake formation and the processes responsible for causing a glacier dam to release its water. A survey is also made of the locations where major jokulhlaup events are known to have occurred in the state of Alaska. C1 Natl Weather Serv, Alaska Pacific River Forecast Ctr, Anchorage, AK 99502 USA. RP Gangadean, D (reprint author), Natl Weather Serv, Alaska Pacific River Forecast Ctr, 6930 Sand Lake Rd, Anchorage, AK 99502 USA. NR 10 TC 0 Z9 0 U1 2 U2 2 PU AMERICAN WATER RESOURCES ASSOCIATION PI MIDDLEBURG PA 4 W FEDERAL ST, PO BOX 1626, MIDDLEBURG, VA 20118-1626 USA J9 AM WAT RES PY 2000 VL 2000 IS 1 BP 43 EP 47 PG 5 WC Water Resources SC Water Resources GA BQ54P UT WOS:000088719600008 ER PT B AU Croley, TE AF Croley, TE BE Kane, DL TI Adjusting storm frequencies for climate forecasts SO WATER RESOURCES IN EXTREME ENVIRONMENTS, PROCEEDINGS SE AMERICAN WATER RESOURCES ASSOCIATION TECHNICAL PUBLICATION SERIES LA English DT Proceedings Paper CT AWRA 2000 Spring Specialty Conference on Water Resources in Extreme Environments CY MAY 01-03, 2000 CL AMER WATER RESOURCES ASSOC, ALASKA STATE SECT, ANCHORAGE, AK SP Amer Water Resources Assoc, Univ Alaska Fairbanks Water & Environm Res Ctr, Alaska Power & Tel Co, BP Explorat, GW Sci, Harza Engn Co, Meridian Management Inc, Montgomery Watson, Oasis Environm Inc, Remote Utilities Syst Grp HO AMER WATER RESOURCES ASSOC, ALASKA STATE SECT DE storms; exceedance frequencies; weather forecasts; probability; estimation; climate AB Storm frequency estimates (e.g., maximum precipitation or flow probabilities) allow engineers and hydrologists to assess risks associated with their decisions during the design, construction, and operation of water resource projects. Storm frequencies for the future are often estimated directly from past historical records of sufficient length. The estimation requires no detailed knowledge of the area's meteorology, but presumes it remains unchanged in the future. However, the climate seldom remains static. Numerous climate forecasts of meteorology probabilities over extended periods are now available to the water resource engineer and hydrologist. It is possible to use these meteorology forecasts directly in the estimation of storm frequencies from the historical record. It is more desirable to do so now than at any time past, since meteorology forecasts have been improving and are now better than their predecessors. A heuristic approach is defined here to estimate storm frequencies that recognize forecasts of extended weather probabilities. Basically, those groups of historical meteorology record segments matching forecast meteorology probabilities are weighted more than others, during the estimation of storm frequencies. (Affiliated groups of hydrology record segments may be similarly weighted for hydrological estimation; e.g., flood frequency estimation.) An example frequency estimation of maximum flow is made using currently available agency meteorology forecasts in the US and Canada. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Croley, TE (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI MIDDLEBURG PA 4 W FEDERAL ST, PO BOX 1626, MIDDLEBURG, VA 20118-1626 USA J9 AM WAT RES PY 2000 VL 2000 IS 1 BP 269 EP 274 PG 6 WC Water Resources SC Water Resources GA BQ54P UT WOS:000088719600045 ER PT J AU Balk, B Elder, K AF Balk, B Elder, K TI Combining binary decision tree and geostatistical methods to estimate snow distribution in a mountain watershed SO WATER RESOURCES RESEARCH LA English DT Article ID SPATIAL-DISTRIBUTION; ALPINE CATCHMENT; ENERGY-BALANCE; COVER; MODEL; EQUIVALENT; TERRAIN; PRECIPITATION; SIMULATIONS; RADIATION AB We model the spatial distribution of snow across a mountain basin using an approach that combines binary decision tree and geostatistical techniques. In April 1997 and 1998, intensive snow surveys were conducted in the 6.9-km(2) Loch Vale watershed (LVWS), Rocky Mountain National Park, Colorado. Binary decision trees were used to model the large-scale variations in snow depth, while the small-scale variations were modeled through kriging interpolation methods. Binary decision trees related depth to the physically based independent variables of net solar radiation, elevation, slope, and vegetation cover type. These decision tree models explained 54-65% of the observed variance in the depth measurements. The tree-based modeled depths were then subtracted from the measured depths, and the resulting residuals were spatially distributed across LVWS through kriging techniques. The kriged estimates of the residuals were added to the tree-based modeled depths to produce a combined depth model. The combined depth estimates explained 60-85% of the variance in the measured depths. Snow densities were mapped across LVWS using regression analysis. Snow-covered area was determined from high-resolution aerial photographs. Combining the modeled depths and densities with a snow cover map produced estimates of the spatial distribution of snow water equivalence (SWE). This modeling approach offers improvement over previous methods of estimating SWE distribution in mountain basins. C1 Colorado State Univ, Dept Earth Resources, Ft Collins, CO 80523 USA. RP Balk, B (reprint author), NWS Alaska River Forecast Ctr, 6930 Sand Lake Rd, Anchorage, AK 99502 USA. NR 58 TC 90 Z9 93 U1 1 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN PY 2000 VL 36 IS 1 BP 13 EP 26 DI 10.1029/1999WR900251 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 271NZ UT WOS:000084601500004 ER PT J AU Minh, TB Prudente, MS Watanabe, M Tanabe, S Nakata, H Miyazaki, N Jefferson, TA Subramanian, A AF Minh, TB Prudente, MS Watanabe, M Tanabe, S Nakata, H Miyazaki, N Jefferson, TA Subramanian, A TI Recent contamination of persistent chlorinated endocrine disrupters in cetaceans from the North Pacific and Asian coastal waters SO WATER SCIENCE AND TECHNOLOGY LA English DT Review DE cetaceans; coplanar PCBs; persistent organochlorines; tris(4-chlorophenyl)methane; tris(4-chlorophenyl)methanol; 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents ID PORPOISE PHOCOENA-PHOCOENA; WHALES DELPHINAPTERUS-LEUCAS; ISOMER-SPECIFIC ANALYSIS; MUSSELS PERNA-VIRIDIS; POLYCHLORINATED-BIPHENYLS; MARINE MAMMALS; ST-LAWRENCE; ORGANOCHLORINE CONTAMINANTS; COPLANAR PCBS; TRIS(4-CHLOROPHENYL)METHANOL AB To elucidate the global distribution and toxicological impacts of persistent organochlorines (OCs) on cetaceans, the present study determined the concentrations of organochlorine pesticides such as DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and PCBs including toxic coplanar congeners in the blubber of 10 species of adult male odontoceti cetaceans collected from several locations in the North Pacific Ocean and coastal waters of Japan, Hong Kong, Philippines and India during 1985-1997. Concentrations of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl)methanol (TCPMOH), which are among the newly identified contaminants, were also determined. Residue pattern was in the order of DDTs greater than or equal to PCBs>CHLs>HCHs>HCB>TCPMOH>TCPMe. Greater DDT concentrations were found in cetaceans from the Japan Sea, coastal waters of Hong Kong and India, indicating serious marine pollution in industrialized Asian nations and current usage of DDTs in tropical regions. In general, cetaceans inhabiting cold and temperate waters contained relatively higher concentrations of PCBs, HCHs, CHLs and HCB as compared with those from tropical regions, reflecting atmospheric transport from the tropical sources to the northern sinks. Latitudinal distribution of TCPMe and TCPMOH in cetaceans from the North Pacific Ocean and Asian coastal waters was similar to that of DDTs, suggesting the less transportable nature of TCPMe and TCPMOH in the marine environment. Penta- and hexa-chlorobiphenyls ware 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 dolphin from Philippines) to 510pg/g wet wt tin humpbacked dolphin from I-long Kong). Toxic evaluation of coplanar PCBs using TEQ concept indicates an increasing impact on cetaceans from mid-latitudes. Mono-ortho congener IUPAC 118 or non-ortho congener IUPAC 126 was estimated to have the greatest toxicity contribution. The estimated TEQ concentrations in the blubber of some cetacean species exceeded the level associated with immunosuppresion in harbour seals. C1 Ehime Univ, Ctr Marine Environm Studies, Matsuyama, Ehime 7908566, Japan. De La Salle Univ, Sci Educ Dept, Manila 1004, Philippines. Kumamoto Univ, 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. Annamalai Univ, Ctr Adv Study Marine Biol, Parangipettai 608502, India. RP Minh, TB (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 38 TC 14 Z9 15 U1 3 U2 13 PU I W A PUBLISHING PI LONDON PA ALLIANCE HOUSE, 12 CAXTON ST, LONDON SW1H0QS, ENGLAND SN 0273-1223 J9 WATER SCI TECHNOL JI Water Sci. Technol. PY 2000 VL 42 IS 7-8 BP 231 EP 240 PG 10 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA 376WL UT WOS:000165479700029 ER PT J AU Gould, P Ostrom, P Walker, W AF Gould, P Ostrom, P Walker, W TI Foods, trophic relationships, and migration of Sooty and Short-tailed Shearwaters associated with squid and large-mesh driftnet fisheries in the North Pacific Ocean SO WATERBIRDS LA English DT Article DE Central Pacific Ocean; driftnet; food; migration; stable isotopes; trophic relationships; Short-tailed Shearwater; Sooty Shearwater Puffinus griseus; Puffinus tenuirostris ID VERTICAL-DISTRIBUTION; CARBON ISOTOPES; STABLE ISOTOPES; BERING SEA; DIET; NITROGEN; SEABIRDS; FRACTIONATION; CALIFORNIA; DELTA-C-13 AB We salvaged dead birds from high seas driftnets in the Central North Pacific Ocean during a study of the impact of high seas driftnet fishing on marine ecosystems. Digestive tract contents and stable isotopes of nitrogen and carbon in breast muscles of these birds were analyzed to assess the effect of driftnets on the trophic relationships of marine birds. The diets of Sooty (Puffinus griseus) and Short-tailed (P. tenuirostris) Shearwaters associated with high seas driftnets in the transitional region of the North Pacific Ocean over lap broadly. The principal differences between them include 1) Sooties prey more heavily on immature stages of invertebrates, especially the barnacle Lepas fascicularis than do Short-tails, 2) Pacific saury (Cololabis saira) are the primary fish taken by Sooties while lanternfish (Myctophidae) are the primary fish taken by Short-tails, and 3) Sooties lake a wider variety of prey than do Short-tails. During the last years of extensive high seas driftnet fishing (early 1990's), both shearwaters augmented their diets with about 15% offal and discards from fishing vessels. Values for stable isotopes of nitrogen and carbon in breast muscle tissues (delta(15)N and delta(15)C) indicate the extent and timing of movements of Sooty Shearwaters: including arrival of migrants from the south Pacific (April-May), east to west movement from the eastern Pacific (May-June), and west to east movement from Japan (August-September). Fall migrant Sooties were not detected. The only movements of Short-tails that ive detected were a few south-bound migrants in September-November. C1 Alaska Sci Ctr, Natl Biol Serv, Anchorage, AK 99503 USA. Michigan State Univ, Dept Geol Sci, E Lansing, MI 48824 USA. NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Gould, P (reprint author), Alaska Sci Ctr, Natl Biol Serv, 1011 E Tudor Rd, Anchorage, AK 99503 USA. EM p.j.gould@att.net NR 74 TC 6 Z9 7 U1 2 U2 12 PU WATERBIRD SOC PI WASHINGTON PA NATL MUSEUM NATURAL HISTORY SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 1524-4695 EI 1938-5390 J9 WATERBIRDS JI Waterbirds PY 2000 VL 23 IS 2 BP 165 EP 186 PG 22 WC Ornithology SC Zoology GA 350JJ UT WOS:000089097300003 ER PT J AU Esler, D Bowman, TD O'Clair, CE Dean, TA McDonald, LL AF Esler, D Bowman, TD O'Clair, CE Dean, TA McDonald, LL TI Densities of Barrow's Goldeneyes during winter in prince william sound, Alaska in relation to habitat, food and history of oil contamination SO WATERBIRDS LA English DT Article DE Alaska; Barrow's Goldeneye; Bucephala islandica; density; Exxon Valdez oil spill; food; habitat; population recovery; Prince William Sound ID EXXON-VALDEZ OIL; BUCEPHALA-ISLANDICA; SPILL; SELECTION; IMPACT; BIRDS; DUCKS; SIZE AB We evaluated variation in densities of Barrow's Goldeneyes (Bucephala islandica) during winter at 214 sites within oiled and unoiled study areas in Prince William Sound, Alaska in relation to physical habitat attributes, prey biomass, and history of habitat contamination by the 1989 Exxon Valdez oil spill. Using general linear model analyses, we found that goldeneye densities were positively associated with occurrence of a stream within 200 m, lack of exposure to wind and waves, and mixed (versus rocky) substrate. We speculate that these associations relate to habitat profitability via selection of beneficial attributes and avoidance of detrimental features. We also determined that biomass of blue mussels (Mytilus trossulus), the primary prey was not related to Barrow's Goldeneye densities; we suggest that mussel standing stock exceeds predation demands in our study areas and, thus, does not dictate goldeneye distribution. After accounting for habitat effects, we detected no effect of history of oil contamination on Barrow's Goldeneye densities, suggesting that populations have recovered from the oil spill. Although other studies documented hydrocarbon exposure in Barrow's Goldeneyes through at least 1997, either the level of exposure did not affect populations via reductions in survival, or effects of oil exposure were offset by immigration. C1 US Geol Survey, Alaska Biol Sci Ctr, Anchorage, AK 99503 USA. US Fish & Wildlife Serv, Migratory Bird Management, Anchorage, AK 99503 USA. Natl Oceanog & Atmospher Adm, Auke Bay Lab, Juneau, AK 99801 USA. Coastal Resources Associates Inc, Vista, CA 92083 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 35 TC 6 Z9 6 U1 2 U2 5 PU WATERBIRD SOC PI WASHINGTON PA NATL MUSEUM NATURAL HISTORY SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0738-6028 J9 WATERBIRDS JI Waterbirds PY 2000 VL 23 IS 3 BP 423 EP 429 DI 10.2307/1522179 PG 7 WC Ornithology SC Zoology GA 394HY UT WOS:000166519000008 ER PT J AU Thompson, RL Edwards, R AF Thompson, RL Edwards, R TI An overview of environmental conditions and forecast implications of the 3 May 1999 tornado outbreak SO WEATHER AND FORECASTING LA English DT Article ID SUPERCELL; BOUNDARIES; DRYLINE; STORMS; WINDS AB An overview of conditions associated with the Oklahoma- Kansas tornado outbreak of 3 May 1999 is presented, with emphasis on the evolution of environmental and supercellular characteristics most relevant to the prediction of violent tornado episodes. This examination provides a unique perspective of the event by combining analyses of remote observational data and numerical guidance with direct observations of the event in the field by forecasters and other observers. The 3 May 1999 outbreak included two prolific supercells that produced several violent tornadoes, with ambient parameters comparable to those of past tornado outbreaks in the southern and central Great Plains. However, not all aspects leading to the evening of 3 May unambiguously favored a major tornado outbreak. The problems that faced operational forecasters at the Storm Prediction Center are discussed in the context of this outbreak, including environmental shear and instability, subtle processes contributing to convective initiation, the roles of preexisting boundaries, and storm- relative flow. This examination reveals several specific aspects where conceptual models are deficient and/ or additional research is warranted. C1 Storm Predict Ctr, Norman, OK 73069 USA. RP Thompson, RL (reprint author), Storm Predict Ctr, 1313 Halley Circle, Norman, OK 73069 USA. NR 27 TC 40 Z9 40 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 2000 VL 15 IS 6 BP 682 EP 699 DI 10.1175/1520-0434(2000)015<0682:AOOECA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300003 ER PT J AU Kain, JS Goss, SM Baldwin, ME AF Kain, JS Goss, SM Baldwin, ME TI The melting effect as a factor in precipitation-type forecasting SO WEATHER AND FORECASTING LA English DT Article ID MODEL; TESTS AB The process of atmospheric cooling due to melting precipitation is examined to evaluate its contribution to determining precipitation type. The " melting effect'' is typically of second- order importance compared to other processes that influence the lower- tropospheric air temperature and hence the type of precipitation that reaches the ground. In some cases, however, cooling due to melting snowflakes can emerge as the dominant agent of temperature change, occasionally surprising forecasters (and the public) by inducing an unexpected changeover from rain to heavy snow. One such case occurred on 3- 4 February 1998 in east- central Tennessee and surrounding areas. Commonly applied considerations for predicting precipitation type had convinced forecasters that significant snowfall was not likely with this event. However, real- time observations and a postevent analysis by forecasters at the Storm Prediction Center led to the hypothesis that the melting effect must have provided the cooling necessary to allow widespread heavy snowfall. To test this hypothesis, the Pennsylvania State University- NCAR Mesoscale Model was used to generate a mesoscale- resolution, four- dimensional dataset for this event. Diagnostic analysis of the model output confirmed that cooling due to melting snowflakes was of a sufficient magnitude to account for the disparity between observed and forecasted lower- tropospheric temperatures in this case. A simple formula is derived to provide a " rule of thumb'' for anticipating the potential impact of the melting effect. In addition, guidelines are provided for identifying meteorological patterns that favor a predominance of the melting effect. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Cooperat Inst Mesoscale Meteorol Studies, Norman, OK USA. NOAA, NWS, Storm Predict Ctr, Norman, OK USA. RP Kain, JS (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 22 TC 36 Z9 40 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 2000 VL 15 IS 6 BP 700 EP 714 DI 10.1175/1520-0434(2000)015<0700:TMEAAF>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300004 ER PT J AU Nance, LB Colman, BR AF Nance, LB Colman, BR TI Evaluating the use of a nonlinear two-dimensional model in downslope windstorm forecasts SO WEATHER AND FORECASTING LA English DT Article ID MOUNTAIN WAVES; PREDICTION AB Severe downslope windstorms are a mesoscale, primarily wintertime, phenomenon that affect regions in the lee of large mountain ranges. The resolution of current weather prediction models is too coarse to explicitly predict downslope windstorms. Hence, additional operational tools are needed for making downslope windstorm forecasts. Current windstorm forecast techniques commonly utilize a tool referred to as a " decision tree. '' Although decision trees provide valuable guidance, operational forecasters have not found this type of tool to be highly reliable. With recent advances in computer technology, a new type of operational tool is available for forecasting downslope windstorms: two- dimensional, nonlinear, mesoscale numerical models. This study investigates whether this type of model, initialized with upstream profiles taken from operational Eta Model forecasts, can produce accurate downslope windstorm forecasts. Numerical simulations for high- wind events that affected seven regions in the United States between January 1993 and April 1997 indicate this tool is able to produce lee- slope wind speeds that meet the local peak gust threshold for a High Wind Warning for a majority of those cases where observed winds met this threshold. These simulations were initialized with upstream soundings taken from the 12- and 18- h Eta forecasts valid at the time of each high- wind event. A comparison for one region between the number of events for which High Wind Watches were posted and the number of events for which the two- dimensional model prediction met the peak gust threshold suggests this new tool would be a definite improvement over the current forecast technique. On the other hand, a preliminary test of the model's ability to differentiate between windstorm and nonwindstorm events suggests the false warning rate for this tool may be high. Further testing of this tool is ongoing and will continue through the winter months of 2000/ 01. C1 Univ Colorado, NOAA, Environm Technol Lab, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Natl Weather Serv, Forecast Off, Seattle, WA USA. RP Nance, LB (reprint author), Univ Colorado, NOAA, Environm Technol Lab, Cooperat Inst Res Environm Sci, R-ET7,325 Broadway, Boulder, CO 80303 USA. NR 27 TC 7 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 2000 VL 15 IS 6 BP 715 EP 729 DI 10.1175/1520-0434(2000)015<0715:ETUOAN>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300005 ER PT J AU Sikora, TD Friedman, KS Pichel, WG Clemente-Colon, P AF Sikora, TD Friedman, KS Pichel, WG Clemente-Colon, P TI Synthetic aperture radar as a tool for investigating polar mesoscale cyclones SO WEATHER AND FORECASTING LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; SEA-SURFACE; IMAGERY; FEATURES; WAVES; GULF; LOWS AB Polar mesoscale cyclones are intense vortices that form in cold, marine air masses poleward of major jet streams and frontal zones. Synthetic aperture radar (SAR) should be considered as a potential tool for the study of polar mesoscale cyclones because of its ability to remotely sense, at least qualitatively, the high- resolution near- surface wind field independent of daylight and atmospheric conditions. Four case studies demonstrating this ability are presented. SAR imagery from the Canadian Space Agency's RADARSAT are compared to corresponding infrared imagery, surface analyses, and upper- air analyses. In three of the four case studies, it is argued that the addition of SAR imagery to the process of generating a manual surface analysis would have led to a better product. Moreover, it is demonstrated that the SAR imagery reveals a host of marine- meteorological phenomena in the vicinity of the polar mesoscale cyclones including atmospheric gravity waves, roll vortices, and cellular convection. Because of the high- resolution attributes of SAR imagery, SAR shows promise to aid the forecaster and researcher in the study of marine- meteorological phenomena such as polar mesoscale cyclones. C1 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. Caelum Res Corp, Camp Springs, MD USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD USA. RP Sikora, TD (reprint author), USN Acad, Dept Oceanog, 572M Holloway Rd, Annapolis, MD 21402 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 37 TC 18 Z9 18 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 2000 VL 15 IS 6 BP 745 EP 758 DI 10.1175/1520-0434(2000)015<0745:SARAAT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300007 ER PT J AU Quinn, TP Gilsinn, JD Rippey, W AF Quinn, TP Gilsinn, JD Rippey, W TI A welding cell with its own web site - An automated welding cell takes advantage of Internet technologies to reduce downtime and save travel time for the people who design and maintain it SO WELDING JOURNAL LA English DT Article C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Quinn, TP (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 1 TC 0 Z9 1 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 JAN PY 2000 VL 79 IS 1 BP 46 EP 48 PG 3 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 271JU UT WOS:000084591100009 ER PT J AU Rippey, W Gilsinn, J Flitter, L AF Rippey, W Gilsinn, J Flitter, L TI Networking of welding applications: A Tutorial - Knowing the basics behind network technology will help users of welding equipment identify where networks may be most beneficial SO WELDING JOURNAL LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD USA. RP Rippey, W (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 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 JAN PY 2000 VL 79 IS 1 BP 49 EP 53 PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 271JU UT WOS:000084591100010 ER PT J AU Wijesinha, AL Kumar, SP Sidhu, DP AF Wijesinha, AL Kumar, SP Sidhu, DP TI Handover and new call blocking performance with dynamic single-channel assignment in linear cellular arrays SO WIRELESS NETWORKS LA English DT Article ID COMMUNICATION-SYSTEMS; NETWORKS; ALLOCATION AB We consider dynamic assignment of a single channel in a linear cellular array, and derive closed-form expressions for the blocking probability of handover calls and new calls in terms of the array size and traffic load assuming a Markov traffic model. Handover and new call blocking performance in the limit of large arrays and extreme traffic loads is also determined. C1 Towson Univ, Dept Comp & Informat Sci, Towson, MD 21252 USA. Natl Inst Stand & Technol, Adv Network Technol Div, Informat Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Maryland Ctr Telecommun Res, Baltimore, MD 21250 USA. Univ Maryland, Dept Comp Sci & Elect Engn, Baltimore, MD 21250 USA. RP Wijesinha, AL (reprint author), Towson Univ, Dept Comp & Informat Sci, Towson, MD 21252 USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1022-0038 J9 WIREL NETW JI Wirel. Netw. PY 2000 VL 6 IS 2 BP 121 EP 129 DI 10.1023/A:1019173111150 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 319XE UT WOS:000087368600004 ER PT S AU Deiker, S Chevenak, J Hilton, GC Huber, ME Irwin, KD Martinis, JM Nam, S Wollman, DA AF Deiker, S Chevenak, J Hilton, GC Huber, ME Irwin, KD Martinis, JM Nam, S Wollman, DA BE Flanagan, KA Siegmund, OHW TI Development of arrays of TES X-ray detectors SO X-RAY AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Instrumentation for Astronomy IX CY AUG 02-04, 2000 CL SAN DIEGO, CA SP SPIE DE transition edge sensors; microcalorimeters; cryogenic detectors; detector arrays; x-ray astronomy; microanalysis AB Both the x-ray astrophysics and microanalysis communities need large format arrays of high-spectral-resolution x-ray detectors. To meet this need, we are fabricating multi-pixel arrays of our successful single pixel transition edge sensor (TES) x-ray microcalorimeters. We will adapt SQUID multiplexing technology already in use with our infrared TES bolometer arrays to reduce the wiring and power dissipation at the cold stage of our cryostat. Room temperature digital feedback electronics have also been developed to simplify the read-out of large numbers of pixels, and microfabrication techniques are being explored to enable the fabrication of large, close-packed arrays of TES microcalorimeters. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Deiker, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Huber, Martin/B-3354-2011 NR 9 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 0-8194-3785-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 4140 BP 360 EP 366 DI 10.1117/12.409130 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BR53H UT WOS:000166723400035 ER PT S AU Shirley, EL Carlisle, JA Blankenship, SR Smith, RN Terminello, LJ Jia, JJ Callcott, TA Ederer, DL AF Shirley, EL Carlisle, JA Blankenship, SR Smith, RN Terminello, LJ Jia, JJ Callcott, TA Ederer, DL BE Dunford, RW Gemmell, DS Kanter, EP Krassig, B Southworth, SH Young, L TI A band-structure-based approach to modeling x-ray absorption, fluorescence, and resonant inelastic scattering SO X-RAY AND INNER-SHELL PROCESSES SE AIP Conference Proceedings LA English DT Proceedings Paper CT 18th International Conference on X-ray and Inner-Shell Processes CY AUG 23-27, 1999 CL CHICAGO, IL SP Argonne Natl Lab, Natl Sci Fdn, Int Union Pure & Appl Phys, Roper Scientific ID AB-INITIO CALCULATION; MEAN FREE PATHS; OPTICAL-ABSORPTION; VALENCE-BAND; INSULATORS; SEMICONDUCTORS; GRAPHITE; DIAMOND; GAPS AB X-ray optical processes in solids-absorption, fluorescence and resonant scattering-are modeled within a band-structure-based approach to describe electron states. The theory goes beyond a simple one-electron treatment by considering self-energy corrections for electron states, the perturbation acting on electron states because of a core hole, and to a lesser degree, lifetime effects for high-energy electron states in solids. Aspects of the work that suggest extensions to be made in the future are discussed Theoretical results for all three types of xray spectra (absorption, fluorescence and resonant scattering) are presented and compared to experiment. Results are presented for diamond graphite, NaF and AL. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 42 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-713-8 J9 AIP CONF PROC PY 2000 VL 506 BP 283 EP 303 PG 21 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA BP76A UT WOS:000086079900020 ER PT J AU Graham, DW Lupton, JE AF Graham, DW Lupton, JE TI Helium isotopes in historical lavas from Mount Vesuvius Comment on 'Noble gas isotopic ratios from historical lavas and fumaroles at Mount Vesuvius' by D. Tedesco et al. SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Editorial Material ID LOIHI SEAMOUNT; MANTLE VOLATILES; ISLAND; HAWAII; CHEMISTRY; ICELAND; CARBON; ETNA; HE-3 C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA. RP Graham, DW (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. OI Graham, David/0000-0002-7411-1905 NR 23 TC 1 Z9 1 U1 0 U2 1 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 1999 VL 174 IS 1-2 BP 241 EP 244 DI 10.1016/S0012-821X(99)00268-X PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 274RV UT WOS:000084779600018 ER PT J AU Topp, A Bauer, BJ Prosa, TJ Scherrenberg, R Amis, EJ AF Topp, A Bauer, BJ Prosa, TJ Scherrenberg, R Amis, EJ TI Size change of dendrimers in concentrated solution SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; STAR POLYMERS; POLYPROPYLENIMINE DENDRIMERS; ORDERING PHENOMENA; TOPOLOGY; SPHERES; LIGHT AB Solutions of the poly(propylene imine) dendrimers DAB-dendr-(PA)(32) and DAB-dendr-(PA)(64) in methanol are investigated with small angle neutron scattering over the range of dendrimer mass fraction 0.01 less than or equal to x less than or equal to 0.80. The single particle scattering function, P(q), is used to calculate the structure factor, S(q) of the dendrimer solutions and to evaluate the radius of gyration of the dendrimers in dilute solution giving R-g(+)(DAB-dendr-(PA)(32)) = 12.4 +/- 0.2 Angstrom and R-g(+)(DAB-dendr-(PA)(64)) = (15.6 +/- 0.2) Angstrom. In each case the segment density in dilute solution is 0.35 +/- 0.03 g cm(-3), leaving a large fraction of the dendrimer volume accessible to solvent. We define the "dilute solution regime" for dendrimers to extend to a concentration where the swollen dendrimer volume fraction first equals the value 0.64, which comes at a dendrimer weight fraction of x = 0.25. At this concentration, the spatial arrangement of the dendrimers can be described as a random close packing. For higher concentrations, the experimental scattering functions appear to be self-similar up to a mass fraction of x approximate to 0.60. These observations are consistent with a model of concentrated dendrimer solutions which assumes that individual dendrimers collapse to maintain a volume fraction phi approximate to 0.64, which is the volume fraction of random close packing of hard spheres. Preliminary small X-ray scattering data give further evidence of the dendrimer collapse. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. DSM Res, NL-6160 MD Geleen, Netherlands. RP Amis, EJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 40 TC 54 Z9 56 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 28 PY 1999 VL 32 IS 26 BP 8923 EP 8931 DI 10.1021/ma990433q PG 9 WC Polymer Science SC Polymer Science GA 270MY UT WOS:000084540800033 ER PT J AU Daniel, C Jao, TC Bauer, BJ Amis, EJ AF Daniel, C Jao, TC Bauer, BJ Amis, EJ TI Study of ethylene-propylene copolymer thermoreversible gels SO MACROMOLECULES LA English DT Article ID ORGANIC-SOLVENTS; POLYOLEFIN GEL; CRYSTALLINE JUNCTION; MOLECULAR-STRUCTURE; SCATTERING; NETWORK; SIZE AB Molecular structure and rheological properties of ethylene-propylene (EP) random copolymer gels formed in toluene and methylcyclohexane, respectively, have been investigated by small-angle neutron scattering (SANS) and oscillatory shear. In both solvents, SANS results are analyzed by considering a fiberlike structure with a radius cross-section distribution function expressed by w(r) similar to r(-lambda). It is shown that a small change in the EP copolymer ethylene content has a large effect on the density of network connecting fibers but a much smaller effect on the diameter of the fibers. Oscillatory shear experiments reveal that the relaxation rate of the elastic modulus increases with decreasing EP copolymer ethylene content. This behavior indicates a decrease in the density of connections between fibers with decreasing ethylene content. The relationship between the elastic modulus and polymer concentration has also been examined. The results suggest, in light of the theory developed by Jones and Marques for rigid networks, that the rigidity of fibers formed in the gel is achieved only locally. C1 Ethyl Petr Addit Inc, Richmond, VA USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jao, TC (reprint author), Ethyl Petr Addit Inc, Richmond, VA USA. NR 15 TC 2 Z9 2 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 28 PY 1999 VL 32 IS 26 BP 8938 EP 8944 DI 10.1021/ma990711l PG 7 WC Polymer Science SC Polymer Science GA 270MY UT WOS:000084540800035 ER PT J AU Burns, SP Khelif, D Friehe, CA Williams, AG Hignett, P Grant, ALM Hacker, JM Rogers, DP Bradley, EF Weller, RA Cronin, MF Anderson, SP Fairall, CW Paulson, CA AF Burns, SP Khelif, D Friehe, CA Williams, AG Hignett, P Grant, ALM Hacker, JM Rogers, DP Bradley, EF Weller, RA Cronin, MF Anderson, SP Fairall, CW Paulson, CA TI Comparisons of aircraft, ship, and buoy meteorological measurements from TOGA COARE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERE RESPONSE EXPERIMENT; TURBULENCE MEASUREMENTS; FLUX AIRCRAFT; OCEAN; LAYER AB Comparisons of mean ambient temperature, specific humidity, static pressure, and horizontal wind from the five Tropical Ocean-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) boundary layer aircraft were obtained from 38 two- and three-aircraft, close-formation, level runs. These, together with consideration of surface measurements from buoys and ships, led to proposed empirical corrections for the aircrafts temperature, humidity, and pressure measurements, minimizing the systematic errors between the aircraft data sets. The aircraft-measured winds were also compared. The TOGA COARE bulk flux algorithm was used to extrapolate the low-level aircraft data to the individual ship and buoy sensor heights for 267 overflight comparisons. In addition, all low-level aircraft data and corresponding ship and buoy data from boundary layer missions were extracted and adjusted to a 10-m reference height. The recommended aircraft corrections bring the aircraft-ship-buoy data sets into better agreement, resulting in a consistent data set for air-sea interaction analyses. Frequency distributions of the 10-m aircraft, ship, and buoy data from the boundary layer missions also agree. C1 Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 USA. Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92717 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92717 USA. Hadley Ctr Climate Predict & Res, Bracknell, Berks, England. Minist Def, Meteorol Support Grp, DGR&T, London, England. Flinders Inst Atmospher & Marine Sci, Adelaide, SA, Australia. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Commonwealth Sci & Ind Res Org Land & Water, Canberra, ACT, Australia. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Environm Technol Lab, Boulder, CO USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. RP Burns, SP (reprint author), Woods Hole Oceanog Inst, Dept Phys Oceanog, MS 29, Woods Hole, MA 02543 USA. EM sean@wave.eng.uci.edu; dkhelif@uci.edu; cfriehe@uci.edu; awilliams@meto.gov.uk; phignett.msg.mod@gtnet.gov.uk; almgrant@meto.gov.uk; j.hacker@es.flinders.edu.au; drogers@ucsd.edu; frank.bradley@cbr.clw.csiro.au; rweller@whoi.edu; cronin@pmel.noaa.gov; sanderson@whoi.edu; cfairall@etl.noaa.gov; paulson@oce.orst.edu RI Burns, Sean/A-9352-2008; Bradley, Frank/I-6574-2013; Williams, Alastair/P-6946-2014 OI Burns, Sean/0000-0002-6258-1838; Williams, Alastair/0000-0002-0568-8487 NR 28 TC 8 Z9 8 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 DEC 27 PY 1999 VL 104 IS D24 BP 30853 EP 30883 DI 10.1029/1999JD900934 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900001 ER PT J AU Angevine, WM AF Angevine, WM TI Entrainment results including advection and case studies from the Flatland boundary layer experiments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MESOSCALE ETA-MODEL; LAND-SURFACE; BUDGET ANALYSIS; BOREAL FOREST; MIXED-LAYER; MOISTURE; PRAIRIE; HEAT AB Boundary layer top entrainment measurements from the 1996 Flatland boundary layer experiment (Flatland96) were presented by Angevine et al. [1998a]. At that time, no reliable estimates of temperature advection, which could affect the heat budget approach used, were available. This paper presents the entrainment results recalculated with advection estimated from the National Centers for Environmental Prediction mesoscale Eta numerical model. Estimates of the contribution to entrainment by mechanical turbulence (shear) and of the shear-free entrainment ratio are also calculated. A number of case study examples are also presented to elucidate further the complex interactions that govern entrainment. Accounting for advection in the budgets results in a slightly smaller estimate of the entrainment ratio A(R); the mean A(R) is 0.47 + 0.11, and the median is 0.40. These results are still somewhat larger than long-accepted values and comparable to results from some other studies in comparable conditions. The experiments took place in the area near the Flatland Atmospheric Observatory near Champaign-Urbana, Illinois, in June-August 1996. The site is interesting because it is extraordinarily flat, has uniform land use, and is situated in a prime agricultural area. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Angevine, WM (reprint author), NOAA, Aeron Lab, RAL3,325 Broadway, Boulder, CO 80303 USA. EM wangevine@al.noaa.gov RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 25 TC 23 Z9 23 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 DEC 27 PY 1999 VL 104 IS D24 BP 30947 EP 30963 DI 10.1029/1999JD900930 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900006 ER PT J AU Knutson, TR Delworth, TL Dixon, KW Stouffer, RJ AF Knutson, TR Delworth, TL Dixon, KW Stouffer, RJ TI Model assessment of regional surface temperature trends (1949-1997) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DECADAL CLIMATE VARIABILITY; OCEAN-ATMOSPHERE MODEL; NORTH PACIFIC; FINGERPRINT DETECTION; NATURAL VARIABILITY; GREENHOUSE-GAS; GLOBAL TEMPERATURE; AIR-TEMPERATURE; EL-NINO; SIGNALS AB Analyses are conducted to assess whether simulated trends in SST and land surface air temperature from two versions of a coupled ocean-atmosphere model are consistent with the geographical distribution of observed trends over the period 1949-1997. The simulated trends are derived from model experiments with both constant and time-varying radiative forcing. The models analyzed are low-resolution (R15, similar to 4 degrees) and medium-resolution (R30, similar to 2 degrees) versions of the Geophysical Fluid Dynamics Laboratory (GFDL) coupled climate model. Internal climate variability is estimated from long control integrations of the models with no change of external forcing. The radiatively forced trends are based on ensembles of integrations using estimated past concentrations of greenhouse gases and direct effects of anthropogenic sulfate aerosols (G+S). For the regional assessment, the observed trends at each grid point with adequate temporal coverage during 1949-1997 are first compared with the R15 and R30 model unforced internal variability Nearly 50% of the analyzed areas have observed warming trends exceeding the 95th percentile of trends from the control simulations. These results suggest that regional warming trends over much of the globe during 1949-1997 are very unlikely to have occurred due to internal climate variability alone and suggest a role for a sustained positive thermal forcing such as increasing greenhouse gases. The observed trends are then compared with the trend distributions obtained by combining the ensemble mean G+S forced trends with the internal variability "trend" distributions from the control runs. Better agreement is found between the ensemble mean G+S trends and the observed trends than between the model internal variability alone and the observed trends. However, the G+S trends are still significantly different from the observed trends over about 30% of the areas analyzed. Reasons for these regional inconsistencies between the simulated and the observed trends include possible deficiencies in (1) specified radiative forcings, (2) simulated responses to specified radiative forcings, (3) simulation of internal climate variability, or (4) observed temperature records. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Knutson, TR (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308,Forrestal Campus, Princeton, NJ 08542 USA. EM tk@gfdl.gov; td@gfdl.gov; kd@gfdl.gov; rjs@gfdl.gov RI Delworth, Thomas/C-5191-2014; Dixon, Keith/L-7120-2015 OI Dixon, Keith/0000-0003-3044-326X NR 67 TC 86 Z9 93 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 DEC 27 PY 1999 VL 104 IS D24 BP 30981 EP 30996 DI 10.1029/1999JD900965 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900008 ER PT J AU Kiehl, JT Schneider, TL Portmann, RW Solomon, S AF Kiehl, JT Schneider, TL Portmann, RW Solomon, S TI Climate forcing due to tropospheric and stratospheric ozone SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; MAPPING SPECTROMETER; TRENDS AB Radiative forcings, preindustrial to present, are presented due to changes in both tropospheric and total ozone. Unlike previous studies, we use a combination of present-day satellite data, ozonsondes, and a chemistry model to produce a hybrid monthly mean ozone data set from 1870 to 1990. We calculate the radiative forcing due to the prescribed ozone distribution using a three-dimensional climate model that employs seasonally evolving fixed dynamical heating in the stratosphere. We find that tropospheric ozone causes a seasonal fixed dynamical radiative forcing (SEFDH) of 0.30 W m(-2) over the time period 1870-1990. The spatial pattern of forcing is correlated strongly with the change in tropospheric ozone. When we allow for observed changes in stratospheric ozone we calculate that the forcing due to total ozone from 1870 to 1990 is 0.29 W m(-2), with 0.18 from shortwave and 0.11 W m(-2) from longwave processes. Thus reduction of stratospheric ozone since 1970 offsets the forcing by only -0.01 W m(-2). We also consider to what extent increased tropospheric ozone offsets the direct forcing by sulfate aerosols. We find that for June-July-August the sulfate forcing is -0.76 W m(-2), while the addition of ozone forcing reduces this to -0.40 W m(-2). Finally, we carry out sensitivity studies with regard to the uncertainty in preindustrial ozone levels. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA Aeronomy Lab, Boulder, CO USA. RP Kiehl, JT (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM jtkon@ncarucar.edu RI Portmann, Robert/C-4903-2009; Schneider, Timothy/D-2832-2015 OI Portmann, Robert/0000-0002-0279-6087; NR 36 TC 87 Z9 90 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 1999 VL 104 IS D24 BP 31239 EP 31254 DI 10.1029/1999JD900991 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900025 ER PT J AU Wetzel, MA Stowe, LL AF Wetzel, MA Stowe, LL TI Satellite-observed patterns in stratus microphysics, aerosol optical thickness, and shortwave radiative forcing SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLOUD MICROPHYSICS; STRATIFORM CLOUDS; SULFATE AEROSOLS; VALIDATION; PARTICLES; PRODUCT; ALBEDO; MODELS AB A long-term global daily data set of satellite-derived radiances has been applied over oceans to investigate the effect of aerosol particles on marine stratus cloud physical parameters and cloud shortwave radiative forcing. Tropospheric aerosol can indirectly influence cloud reflectance and radiative forcing by acting as cloud condensation nuclei, thus modifying the droplet size distribution and cloud optical properties. The NOAA polar-orbiting satellite advanced very high resolution radiometer Pathfinder Atmosphere (PATMOS) data provide estimates of aerosol optical thickness (AOT) which were utilized to represent the amount of aerosol available to modify marine stratus. Periods of stratospheric aerosol loading were avoided for this analysis. PATMOS multichannel radiances for cloudy pixels were combined with radiative transfer modeling to estimate cloud droplet effective radius and cloud optical thickness for several months and years in (110 km)(2) grid cells between 50 degrees S and 50 degrees N. The results indicate an inverse relationship between aerosol burden and cloud droplet size, including seasonal and regional variability that compares well with known aerosol sources. Analyses suggest an AOT value above which the stratus properties do not change; that is, the indirect effect reaches a "microphysical saturation limit." Radiative flux modeling was used to evaluate the impact of observed cloud characteristics on shortwave forcing. Decreases in droplet size and increases in cloud albedo associated with enhanced AOT produce significantly increased shortwave radiative forcing estimates as compared with "clean background" cloud and aerosol conditions. These results provide observational evidence for the global influence of aerosol on the shortwave radiative forcing by stratus. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20748 USA. Desert Res Inst, Div Atmospher Sci, Reno, NV 89512 USA. RP Wetzel, MA (reprint author), NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20748 USA. EM wetzel@dri.edu NR 31 TC 39 Z9 44 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 DEC 27 PY 1999 VL 104 IS D24 BP 31287 EP 31299 DI 10.1029/1999JD900922 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900029 ER PT J AU Freidenreich, SM Ramaswamy, V AF Freidenreich, SM Ramaswamy, V TI A new multiple-band solar radiative parameterization for general circulation models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DELTA-EDDINGTON APPROXIMATION; WATER-VAPOR; EARTHS ATMOSPHERE; CIRRUS CLOUDS; ABSORPTION; CLIMATE; SCALE; CO2; H2O AB An extensive set of line-by-line plus doubling-adding reference computations for both clear and overcast skies has been utilized to develop, calibrate, and verify the accuracy of a new multiple-band solar parameterization, suitable for use in atmospheric general circulation models. In developing this parameterization the emphasis is placed on reproducing accurately the reference absorbed flux in clear and overcast atmospheres. In addition, a significantly improved representation of the reference stratospheric heating profile, in comparison with that derived from older, broadband solar parameterizations, has been attained primarily because of an improved parameterization of CO2 heating. The exponential-sum-fit technique is used to develop the parameterization of water vapor transmission in the main absorbing bands. An absorptivity approach is used to represent the heating contributions by CO2 and O-2, and a spectral averaging of the continuum-like properties is used to represent the O-3 heating. There are a total of two pseudomonochromatic intervals needed to do the radiative transfer problem in the vertically inhomogeneous atmosphere is 72. The delta-Eddington method is used to solve for the reflection and transmission of the homogeneous layers, while the "adding" method is used to combine the layers. The single-scattering properties of the homogeneous layers can account for all types of scattering and absorbing constituents (molecules, drops, ice particles, and aerosols), given their respective single-scattering properties and mass concentrations. With respect to the reference computational results the clear-sky heating rates are generally accurate to within 10%, and the atmospheric absorbed flux is accurate to within 2%. An analysis is made of the factors contributing to the error in the parameterized cloud absorption in the near infrared. Derivation of the representative drop coalbedo for a band using the mean reflection for an infinitely thick cloud (thick-averaging technique) generally results in a better agreement with the reference cloud absorbed flux than that derived using the mean drop coalbedo (thin-averaging technique), except far high, optically thin water clouds. Further, partitioning the 2500 < nu < 8200 cm(-1) spectral region into several more bands than two (the minimum required) results in an improved representation of the cloud absorbed flux, with a modest increase in the shortwave radiation computational time. The cloud absorbed flux is accurate to within 10%, and the cloudy layer heating rates are accurate to within 15%, for water clouds, while larger errors can occur for ice clouds. The atmospheric absorbed, downward surface, and upward top-of-the-atmosphere fluxes are generally accurate to within 10%. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Freidenreich, SM (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. EM smf@gfdl.gov NR 32 TC 79 Z9 81 U1 1 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 DEC 27 PY 1999 VL 104 IS D24 BP 31389 EP 31409 DI 10.1029/1999JD900456 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900037 ER PT J AU McCollum, JR Krajewski, WF AF McCollum, JR Krajewski, WF TI On the relationship between the GOES precipitation index and ISCCP data set variables SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 6th International Conference of Precipitation on Predictability of Rainfall at the Various Scales CY JUN 29-JUL 01, 1998 CL MAUNA LANI BAY, HI SP Amer Geophys Union, Amer Meterol Soc, Mauna Lani Bay Hotel & Bungalows ID CLIMATOLOGY-PROJECT; CLOUD; RAINFALL AB The GOES Precipitation Index (GPI) is used for global, monthly rainfall estimation in the Global Precipitation Climatology Project(GPCP). Previous work has identified the existence of locally and seasonally varying bias in the GPI estimates. Most sources of bias involve cloud properties, as the GPI method uses the fraction of pixels with infrared cloud temperature below 235 degrees K to estimate monthly rainfall totals averaged over 2.5 degrees x 2.5 degrees latitude/longitude grid boxes. In this work, the bias in the GPI is compared to cloud variables derived by the International Satellite Cloud Climatology Project (ISCCP). ISCCP data are used as predictor variables in regression models with the GPI estimation error as the dependent variable. The GPI estimation error is calculated using the global min gage analysis produced by the GPCP for those locations where the rain gage network density is high. Fourteen ISCCP cloud variables were selected as the predictors in linear and nonlinear regression models. The nonlinear model explains over 60% of the variance of the GPI bias, while the linear model explains about 45% of the variance. Comparison with another method of GPI bias estimation is discussed. C1 Univ Iowa, Iowa Inst Hydraul Res, Dept Civil & Environm Engn, Iowa City, IA 52242 USA. NOAA, Off Res & Applicat, NESDIS, Camp Springs, MD 20746 USA. RP McCollum, JR (reprint author), Univ Iowa, Iowa Inst Hydraul Res, Dept Civil & Environm Engn, Iowa City, IA 52242 USA. EM jmccollum@nesdis.noaa.gov; witold-krajewski@uiowa.edu NR 26 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 1999 VL 104 IS D24 BP 31467 EP 31476 DI 10.1029/1999JD900229 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900043 ER PT J AU Chen, SC Roads, JO Juang, HMH Kanamitsu, M AF Chen, SC Roads, JO Juang, HMH Kanamitsu, M TI Global to regional simulations of California wintertime precipitation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 6th International Conference of Precipitation on Predictability of Rainfall at the Various Scales CY JUN 29-JUL 01, 1998 CL MAUNA LANI BAY, HI SP Amer Geophys Union, Amer Meterol Soc, Mauna Lani Bay Hotel & Bungalows ID WESTERN UNITED-STATES; LIMITED-AREA MODEL; FORECAST SYSTEM; PREDICTION; CENTERS; CIRCULATION; SKILL; ETA AB A global to regional modeling system, capable of making large-scale climate simulations and forecasts and then downscaling these forecasts and simulations to regional scales, is evaluated for the California region. Regional climate simulations of wet and dry winters compare well with available observations, especially in comparison to global simulations. While the global model paints a broad swath of precipitation across the western United States, the regional model, forced by the large-scale background flow produced by the global model, more accurately simulates the increased precipitation over the Sierra Nevada and coastal regions. The regional model is especially advantageous for intense precipitation events at regional spatial scales. Although the regional simulations do not significantly alter the imposed large-scale features, they do significantly enhance the spatial as well as temporal variations of the hydrologic variables. Basically, downscaling by a regional model is a dynamically consistent method, which extends the usefulness of global climate forecasts. Still, current regional simulations are not perfect. Even higher resolution and further improvement in physical parameterizations are still needed. C1 Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, La Jolla, CA 92093 USA. Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. RP Chen, SC (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, 0224, La Jolla, CA 92093 USA. EM schen@ucsd.edu; jroads@ucsd.edu; wd20hh@sgi80.wwb.noaa.gov; wd23mk@sgi79.wwb.noaa.gov NR 38 TC 26 Z9 27 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 1999 VL 104 IS D24 BP 31517 EP 31532 DI 10.1029/1998JD200043 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900046 ER PT J AU Thiaw, WM Barnston, AG Kumar, V AF Thiaw, WM Barnston, AG Kumar, V TI Predictions of African rainfall on the seasonal timescale SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 6th International Conference of Precipitation on Predictability of Rainfall at the Various Scales CY JUN 29-JUL 01, 1998 CL MAUNA LANI BAY, HI SP Amer Geophys Union, Amer Meterol Soc, Mauna Lani Bay Hotel & Bungalows ID SEA-SURFACE TEMPERATURE; CANONICAL CORRELATION-ANALYSIS; NINO SOUTHERN OSCILLATION; ATMOSPHERIC RESPONSE; INDIAN-OCEAN; EAST-AFRICA; PRECIPITATION; ANOMALIES; PATTERNS; CIRCULATION AB Real-time predictions of the rainfall in July-September 1997 and January-March 1998, respectively, for the Sahel and southern Africa at I month lead are presented. The forecast technique is based on canonical correlation analysis (CCA), a multivariate linear statistical model that relates patterns in the predict and held to patterns in the predictor field. In this CCA design, four consecutive 3 month predictor periods are followed by a lead time and a single 3 month predictand period. Cross validation is used to estimate the skill in the forecasts. The forecasts are expressed in terms of departures from climatological probabilities of three equiprobable categories for above-, near-, and below-normal rainfall. Expressing the forecasts in terms of probability anomalies communicates the level of confidence in the forecasts. Forecast verifications have been performed using the Heidke skill (S) score. For the Sahel the July-September 1997 rainfall prediction at 1 month lead showed reasonable skill. Furthermore, it is shown that the Sahel rainfall in July-September is influenced at least partly by Fl Nine-Southern Oscillation (ENSO). In addition, Sahel rainfall is affected by the sea surface temperature pattern in the Atlantic Ocean and perhaps the Indian Ocean. For southern Africa, the S score was +30, suggesting a moderately good forecast for the region as a whole. The results also indicate that ENSO plays an important role in modulating rainfall variations in southern Africa. C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Climate Predict Ctr, Camp Springs, MD 20746 USA. RP Thiaw, WM (reprint author), NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Climate Predict Ctr, Room 800,5200 Auth Rd, Camp Springs, MD 20746 USA. EM wd53wt@ncep.noaa.gov NR 49 TC 23 Z9 23 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 1999 VL 104 IS D24 BP 31589 EP 31597 DI 10.1029/1999JD900906 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900051 ER PT J AU Deng, L Hagley, EW Denschlag, J Simsarian, JE Edwards, M Clark, CW Helmerson, K Rolston, SL Phillips, WD AF Deng, L Hagley, EW Denschlag, J Simsarian, JE Edwards, M Clark, CW Helmerson, K Rolston, SL Phillips, WD TI Temporal, matter-wave-dispersion Talbot effect SO PHYSICAL REVIEW LETTERS LA English DT Article ID INTERFEROMETRY; GRATINGS; ATOMS AB We analyze and experimentally demonstrate a new (temporal) Talbot effect, where a pulsed phase grating is applied to a cloud of cold atoms (Bose-Einstein condensate). In contrast to the usual (spatial) Talbot effect, our atoms gain kinetic energy when diffracted by that pulsed grating. The energy gain and the matter-wave-dispersion relation result in an exact:(no paraxial approximation) Talbot effect where the initial wave front is reconstructed at multiples of a "Talbot time" T-T. We demonstrate the Talbot effect by applying a second pulsed phase grating after a variable delay. When this second grating is applied at even (odd) multiples of T-T/2, it doubles (cancels) the effect of the first pulsed grating. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. RP Deng, L (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Hecker Denschlag, Johannes/B-6047-2008; Clark, Charles/A-8594-2009; Deng, Lu/B-3997-2012; Hagley, Edward/B-4285-2012; Helmerson, Kristian/E-3683-2013; rolston, steven/L-5175-2013 OI Hecker Denschlag, Johannes/0000-0003-1984-4994; Clark, Charles/0000-0001-8724-9885; rolston, steven/0000-0003-1671-4190 NR 26 TC 137 Z9 138 U1 3 U2 22 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 27 PY 1999 VL 83 IS 26 BP 5407 EP 5411 DI 10.1103/PhysRevLett.83.5407 PG 5 WC Physics, Multidisciplinary SC Physics GA 268GQ UT WOS:000084406300001 ER PT J AU Bruun, GM Clark, CW AF Bruun, GM Clark, CW TI Hydrodynamic excitations of trapped Fermi gases SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATE; COLLECTIVE EXCITATIONS; HARMONIC TRAP; TEMPERATURE; TRANSITION; MODES; LI-6 AB We discuss collective excitations of a trapped dilute. Fermi gas within a hydrodynamic approximation. Analytical results an derived for both high- and low-temperature limits and are applied to K-40 and Li-6 systems of current experimental interest. We identify,spectral :signatures which can be used to detect the onset of Fermi degeneracy. Also, we find an interesting::class of internal excitations with an unusual spectrum. Some of our results are relevant to the case of:;trapped bosons as well. Our analysis suggests several experiments which address fundamental problems of,collective motion in quantum fluids. C1 US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Electron & Opt Phys Div, Gaithersburg, MD 20899 USA. RP Bruun, GM (reprint author), NORDITA, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 33 TC 70 Z9 70 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 27 PY 1999 VL 83 IS 26 BP 5415 EP 5418 DI 10.1103/PhysRevLett.83.5415 PG 4 WC Physics, Multidisciplinary SC Physics GA 268GQ UT WOS:000084406300003 ER PT J AU McCormack, RP Koontz, JE Devaney, J AF McCormack, RP Koontz, JE Devaney, J TI Seamless computing with WebSubmit SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB WebSubmit is a Web browser based interface to heterogeneous collections of remote highperformance computing resources. It makes these resources easier to use by replacing a constantly changing range of unfamiliar, command-driven queuing systems and application environments with a single, seamless user interface. WebSubmit lets users run in their regular accounts on the remote system. Strong authentication using the Secure Sockets Layer protocol allows registered users to connect to the WebSubmit authority. When validated by the authority they gain access to a group of application modules. Each application module is presented as an HTML form; this form is filled out and submitted to the server, which then processes the request and executes the desired tasks on the specified remote system using the Secure Shell protocol. The system is flexible and extensible, and its modularity promotes ease of use, maintainability, and interface development. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP McCormack, RP (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD DEC 25 PY 1999 VL 11 IS 15 BP 949 EP 963 PG 15 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 307BF UT WOS:000086633000005 ER PT J AU Hobbie, EK AF Hobbie, EK TI Depletion-driven phase separation and reversible aggregation in confined colloidal mixtures SO LANGMUIR LA English DT Article ID FRAGMENTATION; FLUCTUATIONS; COAGULATION; EVOLUTION; KINETICS AB The kinetics of size segregation in quasi-two-dimensional binary mixtures of nearly hard-sphere colloids were studied with video microscopy. During the transient fluid-fluid phase separation that occurs as an intermediate step in the formation of isolated large-sphere crystallites, the structure factor of the (larger) minority component exhibits a spinodal-like evolution, while the cluster-size distribution exhibits scaling reminiscent of colloidal aggregation. The scaled distributions suggest a crossover from power-law (x < 1) to stretched-exponential (x > 1) behavior, where x = k/s is the ratio of the cluster-size index to the average cluster size. A phenomenological explanation based on the reversible Smoluchowski equation is proposed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hobbie, EK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 21 TC 10 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 21 PY 1999 VL 15 IS 26 BP 8807 EP 8812 DI 10.1021/la990397o PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 268TT UT WOS:000084432200008 ER PT J AU Conti, PS AF Conti, PS TI Three-dimensional spectral classification of WN stars: One too many? SO NEW ASTRONOMY LA English DT Article DE stars : Wolf-Rayet ID WOLF-RAYET STARS AB A "three-dimensional'' classification for WN stars has been introduced by Smith, Shara, and Moffat (MNRAS 281, 163, 1996). In addition to the well known "one-dimensional'' ionization subclasses (e.g., WN6, WN7, WN8, etc.) they have added subscripts of "h'', "a'', "b'' and "o'' to refer, respectively, to the connotation of hydrogen being present (from the Balmer/ Pickering emission line decrement), the presence of absorption lines, the appearance of broad emission lines, or no evidence of hydrogen (in stars without a "b''). I will critically evaluate the appropriateness of the latter two subscripts, utilizing the observed distribution functions of line width and line strength for Galactic and LMC WN stars. A "two-dimensional'' classification, providing information about the hydrogen in addition to the ionization is probably warranted. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Conti, PS (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 12 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1092 J9 NEW ASTRON JI New Astron. PD DEC 21 PY 1999 VL 4 IS 7 BP 489 EP 493 DI 10.1016/S1384-1076(99)00037-8 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 279ZF UT WOS:000085076300001 ER PT J AU Romanov, P O'Neill, NT Royer, A McArthur, BLJ AF Romanov, P O'Neill, NT Royer, A McArthur, BLJ TI Simultaneous retrieval of aerosol refractive index and particle size distribution from ground-based measurements of direct and scattered solar radiation SO APPLIED OPTICS LA English DT Article ID SKY BRIGHTNESS MEASUREMENTS; TROPOSPHERIC AEROSOLS; NONSPHERICAL PARTICLES; AUREOLE; ATMOSPHERE; RADIOMETER; INVERSION; AIRBORNE; LIDAR AB Ground-based sunphotometer observation of direct and scattered solar radiation is a traditional tool for providing data on aerosol optical properties. Spectral transmission and solar aureole measurements provide an optical source of aerosol information, which can be inverted for retrieval of microphysical properties (particle size distribution and refractive index). However, to infer these aerosol properties from ground-based remote-sensing measurements, special numerical inversion methods should be developed and applied. We propose two improvements to the existing inversion techniques employed to derive aerosol microphysical properties from combined atmospheric transmission and solar aureole measurements. First, the aerosol refractive index is directly included in the inversion procedure and is retrieved simultaneously with the particle size spectra. Second, we allow for real or effective instrumental pointing errors by including a correction factor for scattering angle errors as a retrieved inversion parameter. The inversion technique is validated by numerical simulations and applied to field data. It is shown that ground-based sunphotometer measurements enable one to derive the real part of the aerosol refractive index with an absolute error of 0.03-0.05 and to distinguish roughly between weakly and strongly absorbing aerosols. The aureole angular observation scheme can be refined with an absolute accuracy of 0.15-0.19 deg. Offset corrections to the scattering angle error are generally found to be small and consistently of the order of -0.17. This error magnitude is deduced to be due primarily to nonlinear field-of-view averaging effects rather than to instrumental errors. (C) 1999 Optical Society of America OCIS codes: 280.1100, 010.1100, 010.1110. C1 Univ Sherbrooke, Ctr Applicat & Rech Teledetect, Sherbrooke, PQ J1K 2R1, Canada. Atmospher Environm Serv, Toronto, ON M3H 5T4, Canada. RP Romanov, P (reprint author), NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, 5200 Auth Rd,WWB 712, Camp Springs, MD 20746 USA. EM promanov@nesdis.noaa.gov RI Romanov, Peter/F-5622-2010 OI Romanov, Peter/0000-0002-2153-8307 NR 47 TC 15 Z9 17 U1 0 U2 5 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 DEC 20 PY 1999 VL 38 IS 36 BP 7305 EP 7320 DI 10.1364/AO.38.007305 PG 16 WC Optics SC Optics GA 269NL UT WOS:000084484400001 PM 18324279 ER PT J AU Rosenkranz, S Osborn, R Mitchell, JF Vasiliu-Doloc, L Lynn, JW Sinha, SK AF Rosenkranz, S Osborn, R Mitchell, JF Vasiliu-Doloc, L Lynn, JW Sinha, SK TI Spin correlations of the magnetoresistive bilayer manganite La1.2Sr1.8Mn2O7 SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on New Theories, Discoveries and Applicatins of Superconductors and Relates Materials (New3SC-2) CY MAY 31-JUN 04, 1999 CL LAS VEGAS, NEVADA ID COLOSSAL-MAGNETORESISTANCE; LAYERED LA1.2SR1.8MN2O7; GIANT MAGNETORESISTANCE; RB2CRCL4; BEHAVIOR AB We review our recent neutron and X-ray scattering studies of the 40% hole doped bilayer manganite La1.2Sr1.8Mn2O7,, which exhibits colossal magnetoresistance above the ferromagnetic transition st T-C similar to 113 K. In the paramagnetic region, static diffuse scattering reveals the existence of correlated charges. However, the good agreement of the in-plane spin correlations with the conventional model for quasi two-dimensional XY magnets indicates that the metal-insulator transition is driven by the growth of magnetic correlations. Across the transition, the competition between antiferromagnetic superexchange and ferromagnetic double exchange, observed as canted correlations between spins in neighboring layers within each bilayer, is strongly reduced, indicating a direct link of the double exchange interaction to the hole mobility. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Rosenkranz, S (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 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 18 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 20 PY 1999 VL 13 IS 29-31 BP 3820 EP 3822 DI 10.1142/S0217979299003982 PG 3 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 273QT UT WOS:000084718900089 ER PT J AU Udovic, TJ Huang, Q Karmonik, C Rush, JJ AF Udovic, TJ Huang, Q Karmonik, C Rush, JJ TI Structural ordering and dynamics of LaH3-x SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 04-09, 1998 CL ZHEJIANG, PEOPLES R CHINA SP Zhejiang Univ DE hydrogen motions; lanthanum hydride; neutron diffraction; quasielastic neutron scattering; vibrational spectroscopy ID SWITCHABLE OPTICAL-PROPERTIES; RARE-EARTH HYDRIDES; NEUTRON-SCATTERING; LANTHANUM HYDRIDES AB The structural arrangements, optic-vibrational density of states, and diffusive motions of hydrogen land deuterium) in the light-rare-earth hydride LaH3-x (for small hydrogen-vacancy fractions x) have been measured by neutron powder diffraction, neutron vibrational spectroscopy, and quasielastic neutron scattering. Diffraction measurements of LaD3-x indicate preparation-dependent changes in structural ordering below room temperature. Vibrational spectra of both pure and isotopically mixed samples reflect the presence of significant H-H interactions involving the hydrogen located in the octahedral and tetrahedral interstices of the fcc metal sublattice. Quasielastic scattering measurements above room temperature reveal two types of hydrogen motions: a localized 'rattling' motion of the octahedrally coordinated hydrogen and a long-range diffusional motion via the hydrogen vacancies. A sample color change from black to copperish-orange observed in the vicinity of the highest hydrogen concentrations likely reflects a transition from optical opacity to optical transparency, as reported for LaH3-x thin films. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Natl Inst Stand & Technol, NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Udovic, TJ (reprint author), Natl Inst Stand & Technol, NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Karmonik, Christof/B-6150-2009 NR 12 TC 7 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD DEC 20 PY 1999 VL 293 BP 113 EP 117 DI 10.1016/S0925-8388(99)00309-6 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 262KD UT WOS:000084065500021 ER PT J AU Wang, SW Levy, H Li, G Rabitz, H AF Wang, SW Levy, H Li, G Rabitz, H TI Fully equivalent operational models for atmospheric chemical kinetics within global chemistry-transport models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC OZONE; CIRCULATION; OH AB A major portion of the computational effort in simulations by three-dimensional (3-D) chemistry-transport models is consumed in chemical kinetics calculations which repeatedly solve coupled ordinary differential equations. To address this burden, this paper introduces a high-speed fully equivalent operational model (FEOM) for chemical kinetics calculations. The FEOM consists of a hierarchical correlated-function expansion capturing the input-output relationships of chemical kinetics. As an initial test of the FEOM approach for chemical kinetics calculations in 3-D models, this paper develops the FEOMs for CO-CH4-NOy-H2O chemistry to obtain the time-dependent chemical ozone production and destruction rates in global chemistry-transport model (GCTM) simulations. The FEOMs are constructed for all GCTM model levels, all 12 months of the year, every 10 degrees of latitude, for two types of surface albedo, and for all tropospheric values of H2O, CO, NOx, and O-3. It is shown that the simulated global ozone fields using the FEOMs in the GCTM ozone simulation are at least as accurate and in some cases better than those obtained by using four-dimensional interpolative look-up tables. Future work will expand the FEOM approach to more detailed chemical schemes, including nonmethane hydrocarbon chemistry in 3-D chemistry-transport model simulations. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. RP Wang, SW (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. EM sww@gfdl.gov NR 30 TC 48 Z9 48 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1999 VL 104 IS D23 BP 30417 EP 30426 DI 10.1029/1999JD900830 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 268DR UT WOS:000084399500021 ER PT J AU Novelli, PC Lang, PM Masarie, KA Hurst, DF Myers, R Elkins, JW AF Novelli, PC Lang, PM Masarie, KA Hurst, DF Myers, R Elkins, JW TI Molecular hydrogen in the troposphere: Global distribution and budget SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC CARBON-MONOXIDE; TRACE GAS EMISSIONS; TRANSPORT MODEL; MARINE AIR; CO; CHEMISTRY; H-2; OH; FORMALDEHYDE; OXIDATION AB Molecular hydrogen (H-2) has been measured since 1989 in air samples collected using a globally distributed sampling network. Time series from 50 locations are used to better define the distribution and recent changes of H-2 in the remote lower troposphere. These data show that the globally averaged H-2 mixing ratio between 1991 and 1996 was about 531 +/- 6 parts per billion (ppb). Hydrogen exhibited well-defined seasonal cycles in each hemisphere, with similar seasonal maxima (530-550 ppb). However, in the Northern Hemisphere the seasonal minimum was 70 ppb deeper than in the Southern Hemisphere (similar to 450 and 520 ppb, respectively), resulting in similar to 3% more H-2 in the south than in the north. With these data we have reevaluated the global H-2 budget. Methane oxidation is the largest source of H-2 to the troposphere, and soil uptake accounts for much of its sink. The global annual turnover is estimated as similar to 75 Tg H-2 yr(-1). The annual turnover, combined with a calculated tropospheric burden of 155 Tg, indicates a lifetime of similar to 2 years. While our understanding of the global distribution of the sources and sinks of H-2 is Still incomplete, the lower annual minimum in the north may be reasonably attributed to hemispheric asymmetry in uptake by soils. The seasonal cycles in the two hemispheres show unusual similarities: the northern and the southern seasonal maxima and minima were offset by only a few months. We suggest that the seasonal cycle in the Southern Hemisphere is dominated by H-2 emissions from biomass burning. C1 NOAA, CMDL, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Novelli, PC (reprint author), NOAA, CMDL, 325 Broadway,R-E-CG1, Boulder, CO 80303 USA. EM pnovelli@cmdl.noaa.gov RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 81 TC 170 Z9 174 U1 0 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 DEC 20 PY 1999 VL 104 IS D23 BP 30427 EP 30444 DI 10.1029/1999JD900788 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 268DR UT WOS:000084399500022 ER PT J AU McPeters, RD Hofmann, DJ Clark, M Flynn, L Froidevaux, L Gross, M Johnson, B Koenig, G Liu, X McDermid, S McGee, T Murcray, F Newchurch, MJ Oltmans, S Parrish, A Schnell, R Singh, U Tsou, JJ Walsh, T Zawodny, JM AF McPeters, RD Hofmann, DJ Clark, M Flynn, L Froidevaux, L Gross, M Johnson, B Koenig, G Liu, X McDermid, S McGee, T Murcray, F Newchurch, MJ Oltmans, S Parrish, A Schnell, R Singh, U Tsou, JJ Walsh, T Zawodny, JM TI Results from the 1995 Stratospheric Ozone Profile Intercomparison at Mauna Loa SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INVERSION ALGORITHM; LIDAR; AEROSOL AB In August 1995, multiple instruments that measure the stratospheric ozone vertical distribution were intercompared at the Mauna Loa Observatory, Hawaii, under the auspices of the Network for the Detection of Stratospheric Change. The instruments included two UV lidar systems, one from the Jet Propulsion Laboratory and the other from Goddard Space Flight Center, electrochemical concentration cell balloon sondes, a ground-based microwave instrument, Dobson-based Umkehr measurements, and a new ground-based Fourier transform infrared instrument. The Microwave Limb Sounder instrument on the Upper Atmosphere Research Satellite provided correlative profiles of ozone, and there was one close overpass of the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument. The results show that much better consistency among instruments is being achieved than even a few years ago, usually to within the instrument uncertainties. The different measurement techniques in this comparison agree to within +/-10% at almost all altitudes, and in the 20-45 km region most agreed within +/-5%. The results show that the current generation of lidars is capable of accurate measurement of the ozone profile to a maximum altitude of 50 km. SAGE II agreed well with both lidar and balloon sonde down to at least 17 km. The ground-based microwave measurement agreed with other measurements from 22 km to above 50 km. One minor source of disagreement continues to be the pressure-altitude conversion needed to compare a measurement of ozone density versus altitude with a measurement of ozone mixing ratio versus pressure. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CIRES, Boulder, CO 80303 USA. NOAA, NESDIS, Camp Springs, MD 20746 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. Hughes STX Corp, Greenbelt, MD 20771 USA. NOAA, CMDL, Boulder, CO 80303 USA. Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. NOAA, Mauna Loa Observ 154, Hilo, HI 96720 USA. GATS Inc, Newport News, VA 23606 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP McPeters, RD (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM mcpeters@wrabbit.gsfc.nasa.gov; dhofmann@cmdl.noaa.gov; mark.clark@Colorado.edu; lflynn@orbit.nesdis.noaa.gov; lucien@mls.jpl.nasa.gov; bjohnson@cmdl.noaa.gov; koenig@cmdl1.cmdl.erl.gov; mcdermid@tmf.jpl.nasa.gov; mcgee@aeolus.gsfc.nasa.gov; murcray@ram.phys.du.edu; mike@vortex.atmos.uah.edu; soltmans@cmdl.noaa.gov; parrish@fcrao1.phast.umass.edu; rschnell@cmdl.noaa.gov; j.j.tsou@larc.nasa.gov; j.m.zawodny@larc.nasa.gov RI Flynn, Lawrence/B-6321-2009; McGee, Thomas/G-4951-2013; McPeters, Richard/G-4955-2013 OI Flynn, Lawrence/0000-0001-6856-2614; McPeters, Richard/0000-0002-8926-8462 NR 27 TC 26 Z9 26 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 DEC 20 PY 1999 VL 104 IS D23 BP 30505 EP 30514 DI 10.1029/1999JD900760 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 268DR UT WOS:000084399500026 ER PT J AU Bruhwiler, LP Hamilton, K AF Bruhwiler, LP Hamilton, K TI A numerical simulation of the stratospheric ozone quasi-biennial oscillation using a comprehensive general circulation model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ZONALLY AVERAGED TRANSPORT; INTERANNUAL VARIABILITY; MIDDLE ATMOSPHERE; 2-DIMENSIONAL MODEL; ANTARCTIC OZONE; GLOBAL QBO; OBSERVATIONAL EVIDENCE; DIMENSIONAL MODEL; BUV DATA; CYCLE AB The Geophysical Fluid Dynamics Laboratory's SKYHI general circulation model (GCM) including a new detailed stratospheric photochemistry module has been integrated for over 14 years with an imposed zonally symmetric momentum source designed to force a realistic quasi-biennial oscillation (QBO) in the tropical stratosphere. The GCM: features an internally consistent calculation of the annual stratospheric circulation cycle and exhibits realistic extratropical stratospheric interannual variability, making it appropriate for the detailed investigation of QBO/annual cycle interactions. The simulated ozone QBO is generally realistic in the tropics and subtropics, and, in particular, the QBO in total column ozone agrees quite well with that derived from satellite observations. A detailed analysis of the QBO modulation of the zonal-mean ozone budget has been performed. The advective effects of the QBO-induced residual mean circulation are found to be strongly dependent on season, in accord with recent results from some two-dimensional model studies [Jones et al., 1998; Kinnersley and Tung, 1998]. In addition, the QBO modulation of explicitly resolved eddy transport in the GCM is found to make a significant contribution to the ozone budget, and this helps account for the strong seasonal synchronization of the ozone QBO. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Bruhwiler, LP (reprint author), NOAA, Climate Monitoring & Diagnost Lab, ERL, R-E-CG1,325 Broadway, Boulder, CO 80303 USA. EM lbruhwiler@cmdl.noaa.gov; kph@gfdl.gov NR 71 TC 6 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1999 VL 104 IS D23 BP 30525 EP 30557 DI 10.1029/1999JD900385 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 268DR UT WOS:000084399500028 ER PT J AU Mate, B Lugez, C Fraser, GT Lafferty, WJ AF Mate, B Lugez, C Fraser, GT Lafferty, WJ TI Absolute intensities for the O-2 1.27 mu m continuum absorption SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR-RADIATION; WATER-VAPOR; OXYGEN; ATMOSPHERE; BAND AB Collision-induced absorption coefficients for the 1.27 mu m band of O-2 have been measured at a resolution of 0.5 cm(-1) and an optical path length of 84 m using a Fourier transform spectrometer. Spectra were recorded for sample densities rho from 1 to 10 times that of an ideal gas under standard conditions (T = 273.15 K and P = 101.325 kPa) at temperatures of 253, 273, and 296 K for pure O-2 and O-2/N-2 mixtures. After removing the contributions from the sharp lines of the nu = 0 <-- 0 component of the O-2 a(1)Delta(g) <-- X(3)Sigma(g)(-) band, which overlaps the continuum band, the integrated band strength per unit path length, S = S(O2-O2)rho(O2)(2) + S-O2-(N2) rho(N2)rho(O2), has been determined for several values of the densities, rho(O2) and rho(N2), to give values for SO2-O2 and SO2-N2. At 296 K we find SO2-O2 = 4.847(22) x 10(-43) cm(-2) (molecule/cm(3))(-2) and SO2-N2 = 0.941(50) X 10(-43) cm(-2) (molecule/cm(3))(-2). Type A standard uncertainties are given, that is, +/-1 sigma from a least squares analysis of the integrated-intensity-versus-density data. The S coefficient is in reasonable agreement with the previous measurements of Cho et al. [1963]; however, our value for SO2-N2 is 2.6 times greater than their results. Our derived air coefficient SO2-air is 37% greater than the atmospheric value of Mlawer et al. [1998], after correcting their continuum value for an updated value for the absorption coefficients for the overlapping discrete structure of the O-2 a(1)Delta(g) <-- X(3)Sigma(g)(-) band. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Mate, B (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. EM gerald.fraser@nist.gov NR 20 TC 24 Z9 24 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1999 VL 104 IS D23 BP 30585 EP 30590 DI 10.1029/1999JD900824 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 268DR UT WOS:000084399500031 ER PT J AU Muller, D Anderson, DZ Grow, RJ Schwindt, PDD Cornell, EA AF Muller, D Anderson, DZ Grow, RJ Schwindt, PDD Cornell, EA TI Guiding neutral atoms around curves with lithographically patterned current-carrying wires SO PHYSICAL REVIEW LETTERS LA English DT Article ID OPTICAL FIBERS; LASER AB Laser-cooled neutral atoms from a low-velocity atomic soul ce are guided via a magnetic field generated between two parallel wins on a glass substrate. The atoms bend around three curves, each with a 15-cm radius of curvature, while traveling along a 10-cm-long track. A maximum flux of 2 x 10(6) atoms/sec is achieved with a current density of 3 x 10(4) A/cm(2) in the 100 X 100-mu m cross-section wires. The kinetic energy of the guided atoms in one transverse dimension is measured to be 43 mu K. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Muller, D (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. NR 16 TC 179 Z9 183 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 20 PY 1999 VL 83 IS 25 BP 5194 EP 5197 DI 10.1103/PhysRevLett.83.5194 PG 4 WC Physics, Multidisciplinary SC Physics GA 266LH UT WOS:000084301100003 ER PT J AU Zaliznyak, IA Broholm, C Kibune, M Nohara, M Takagi, H AF Zaliznyak, IA Broholm, C Kibune, M Nohara, M Takagi, H TI Anisotropic spin freezing in the S=1/2 zigzag chain compound SrCuO2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPETING INTERACTIONS; RENORMALIZATION-GROUP; SINGLE-CRYSTALS; SYSTEMS; DIMERIZATION; ANTIFERROMAGNETS; SR2CUO3; MODEL AB We characterize an unusual magnetic phase in orthorhombic SrCuO2 using neutron scattering. SrCuO2 contains zigzag spin chains formed by pairs of linear S = 1/2 chains (J = 180 meV) coupled through a frustrated interaction (\ J'\ less than or similar to 0.1 J). For T < T-c1 = 5.0(4) K, an elastic peak develops in a gapless spectrum indicating spin freezing on a time scale delta t > 2 . 10(-10) s. While the frozen state has long range order along chains (xi(c) > 200c) and a substantial correlation length, xi(a) = 60(25)a, perpendicular to zigzag planes, the correlation length is only xi(b) = 2.2(3)b in the direction of frustrated interactions. We argue that slow dynamics of stripelike cooperative magnetic defects yield this anisotropic frozen state. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Tokyo, Grad Sch Frontier Sci, Dept Adv Mat Sci, Tokyo 1138656, Japan. RP Zaliznyak, IA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RI Takagi, Hidenori/B-2935-2010; Broholm, Collin/E-8228-2011; NOHARA, Minoru/B-1476-2011; Zaliznyak, Igor/E-8532-2014 OI Broholm, Collin/0000-0002-1569-9892; Zaliznyak, Igor/0000-0002-9886-3255 NR 23 TC 35 Z9 35 U1 0 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 20 PY 1999 VL 83 IS 25 BP 5370 EP 5373 DI 10.1103/PhysRevLett.83.5370 PG 4 WC Physics, Multidisciplinary SC Physics GA 266LH UT WOS:000084301100047 ER PT J AU Kozuma, M Suzuki, Y Torii, Y Sugiura, T Kuga, T Hagley, EW Deng, L AF Kozuma, M Suzuki, Y Torii, Y Sugiura, T Kuga, T Hagley, EW Deng, L TI Phase-coherent amplification of matter waves SO SCIENCE LA English DT Article ID BOSE-EINSTEIN CONDENSATION; BRAGG SCATTERING; ATOMS; TRAP AB Phase-coherent matter-wave amplification was demonstrated using Bose-Einstein-condensed rubidium-87 atoms. A small seed matter wave was created with coherent optical Bragg diffraction. Amplification of this seed matter wave was achieved by using the initial condensate as a gain medium through the superradiance effect. The coherence properties of the amplified matter wave, studied with a matter-wave interferometer, were shown to be locked to those of the initial seed wave. The active matter-wave device demonstrated here has great potential in the fields of atom optics, atom Lithography, and precision measurements. C1 Univ Tokyo, Inst Phys, Meguro Ku, Tokyo 1538902, Japan. Gakushuin Univ, Dept Phys, Toshima Ku, Tokyo 1718588, Japan. NIST, Phys Lab, Gaithersburg, MD 20899 USA. RP Kozuma, M (reprint author), Univ Tokyo, Inst Phys, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan. RI Deng, Lu/B-3997-2012; Hagley, Edward/B-4285-2012 NR 17 TC 166 Z9 173 U1 1 U2 15 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 17 PY 1999 VL 286 IS 5448 BP 2309 EP 2312 DI 10.1126/science.286.5448.2309 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 266UK UT WOS:000084318500050 ER PT J AU Mountain, RD AF Mountain, RD TI Molecular dynamics study of water-acetonitrile mixtures SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID EFFECTIVE PAIR POTENTIALS; CLUSTERING CONDITIONS; SIMULATION; LIQUID; PHASES; FLUID; MODEL AB The results of a molecular dynamics simulation study of water acetonitrile mixtures over the temperature range 297 - 415 K are reported. The emphasis is on the microheterogeneous structure present in these mixtures for compositions ranging from 0.1 - 0.9 mole fraction of water. The characterization of the microstructure is presented in terms of site-site pair correlation functions and in terms of the size and shape of water clusters and acetonitrile clusters. C1 Natl Inst Stand & Technol, Phys & Chem Proper Div, Gaithersburg, MD 20899 USA. RP Mountain, RD (reprint author), Natl Inst Stand & Technol, Phys & Chem Proper Div, 100 Bureau Dr Stop 8380, Gaithersburg, MD 20899 USA. NR 43 TC 57 Z9 57 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 16 PY 1999 VL 103 IS 50 BP 10744 EP 10748 DI 10.1021/jp992305+ PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 268PP UT WOS:000084425000011 ER PT J AU Kim, JB Wenthold, PG Lineberger, WC AF Kim, JB Wenthold, PG Lineberger, WC TI Ultraviolet photoelectron spectroscopy of o-, m-, and p-halobenzyl anions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; ELECTRON-AFFINITY; ANGULAR-DISTRIBUTIONS; NEGATIVE-IONS; BENZYL; SINGLET; PHOTODETACHMENT; ENERGIES; STATES AB The 351 nm photoelectron spectra of the ortho, meta, and para isomers of the fluorobenzyl, chlorobenzyl, and bromobenzyl anions all exhibit resolved, analyzable vibrational structure. For a given isomer, the electron affinity increases with increasing halide atomic number, while for a given halogen substituent, the meta isomer has the largest electron affinity and the para isomer has the lowest. The electron affinities of the o-, m-, and p-fluorobenzyl radicals are found to be 1.091 +/- 0.008. 1.173 +/- 0.008, and 0.937 +/- 0.008 eV, respectively, the electron affinities of the o-, m-, and p-chlorobenzyl radicals are 1.257 +/- 0.008, 1.272 +/- 0.008, and 1.174 +/- 0.008 eV, respectively, and the electron affinities of o-, m-, and p-bromobenzyl-radicals are 1.308 +/- 0.008, 1.307 +/- 0.008, and 1.229 +/- 0.008 eV, respectively. Two vibrational progressions are present in all of the halobenzyl spectra, corresponding to the ring-deformation mode and either a ring stretching mode or the CH2 bending mode. The measured electron affinities are used together with previously reported gas-phase acidities to derive the 298 K, methyl C-H bond energies for the corresponding halotoluenes. DH298(C-H) for o-, m-, and p-fluorotoluenes are found to be 90.6, 88.8 +/- 2.1, and 87.6 +/- 2.1 kcal/mol, respectively; DH298(C-H) for o-, m-, and p-chlorotoluenes are 89.0 +/- 3.1, 89.8 +/- 2.1, and 87.5 +/- 2.1 kcal/mol, respectively, and DH298(C-H) for o-, m-, and p-bromotoluenes are 90.2 +/- 3.1, 90.1 +/- 3.1, and 88.5 +/- 3.1 kcal/mol, respectively. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Lineberger, WC (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 45 TC 15 Z9 15 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 16 PY 1999 VL 103 IS 50 BP 10833 EP 10841 DI 10.1021/jp992817o PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 268PP UT WOS:000084425000023 ER PT J AU Schulz, JC Warr, GG Hamilton, WA Butler, PD AF Schulz, JC Warr, GG Hamilton, WA Butler, PD TI A new model for neutron reflectometry of adsorbed surfactant aggregates SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SILICA-WATER INTERFACE; SOLID-LIQUID INTERFACES; NONIONIC SURFACTANTS; CETYLTRIMETHYLAMMONIUM BROMIDE; CATIONIC SURFACTANTS; AQUEOUS-SOLUTION; MICELLAR SOLUTIONS; COLLOIDAL SILICA; X-RAY; ADSORPTION AB A new interpretation of neutron reflectivity data for surfactants adsorbed on hydrophilic solid surfaces has been developed. Motivated by recent atomic force microscopy results, a model of the adsorbed layer is constructed based upon an adsorbed layer consisting of discrete, micelle-like surfactant aggregates of well-defined geometries. Scattering length density profiles and reflectivity curves are calculated for conventional, laterally unstructured adsorbed layers (a bilayer), as well as for cylindrical and spherical surfactant aggregates adsorbed on a hydrophilic surface. It is shown that treating such structured surfactant films as bilayers often results in a good fit to neutron reflectivity data, but that fit parameters lead one to underestimate the film thickness and overestimate the fractional surface coverage by the adsorbed film. C1 Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Warr, GG (reprint author), Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia. RI Schulz, Jamie/B-3819-2008; Butler, Paul/D-7368-2011 NR 62 TC 16 Z9 16 U1 0 U2 4 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 DEC 16 PY 1999 VL 103 IS 50 BP 11057 EP 11063 DI 10.1021/jp990827j PG 7 WC Chemistry, Physical SC Chemistry GA 268PJ UT WOS:000084424500012 ER PT J AU Cowen, JP Shackelford, R McGee, D Lam, P Baker, ET Olson, E AF Cowen, JP Shackelford, R McGee, D Lam, P Baker, ET Olson, E TI Microbial biomass in the hydrothermal plumes associated with the 1998 axial volcano eruption SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DE-FUCA RIDGE; MICROORGANISMS; MANGANESE; VENTS AB The Axial Response Team (ART-1) documented greatly intensified chronic-style hydrothermal plumes at Axial Volcano following a 1998 eruptive event. Significantly higher numbers of bacteria were found in the plume versus background stations and depths, due largely to 5 samples with high numbers (to 1.8 x 10(5) /ml) in far field stations. Highest ratios (0.20) of metal depositing capsuled bacteria to total bacteria were found in the near-field (over caldera) plume. An unusual capsule form (FeCap), that dominated the near field plume capsule populations, was present in all plume samples, but were absent in background samples. Multi-cell filaments, metal-encrusted sheathed clusters and matrix-enmeshed colonies, all uncommon in the water column, were also present in plume samples. C1 Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Sch Oceanog, Seattle, WA 98115 USA. RP Cowen, JP (reprint author), Univ Hawaii, Dept Oceanog, 1000 Pope Rd, Honolulu, HI 96822 USA. RI Lam, Phyllis/D-9574-2011 OI Lam, Phyllis/0000-0003-2067-171X NR 15 TC 12 Z9 12 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 DEC 15 PY 1999 VL 26 IS 24 BP 3637 EP 3640 DI 10.1029/1999GL002343 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 271JQ UT WOS:000084590800015 ER PT J AU Dziak, RP Fox, CG AF Dziak, RP Fox, CG TI Long-term seismicity and ground deformation at Axial Volcano, Juan de Fuca Ridge SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Seismicity along the Juan de Fuca Ridge (JdFR) has been monitored since August 1991 using U.S. Navy hydrophones in the northeast Pacific Ocean. During this time, the focus of JdFR seismicity has been Axial Volcano, where a total of 9055 earthquakes have been detected (1669 located). This activity occurred within 48 discrete swarms along the summit caldera and flank rift zones. From August 1991 to May 1996, Axial Volcano exhibited only one swarm with greater than or equal to 50 earthquakes. From May 1996 to November 1997 swarm activity increased significantly with five swarms of greater than or equal to 50 earthquakes. Activity culminated at the volcano in January 1998 with an 11-day, 8247-event swarm that was the result of a major eruption along the summit and southern flank. Seafloor deformation sensors indicated pre-eruption swarms in October 1995, May 1996, and June 1996 coincided with subsidence of the caldera floor. The 1996-1997 swarm activity increase also coincided with horizontal extension of the north rift zone, consistent with pre-eruption deformation of the volcano. Following the 1998 eruption, swarm activity dramatically decreased and no earthquakes have been detected since April 1998. This is the longest aseismic period (similar to 1 yr) observed at the volcano since acoustic monitoring began, suggesting the January 1998 swarm marked the end of an eruptive cycle at Axial Volcano. C1 Oregon State Univ, NOAA, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. NOAA, Pacific Marine Environm Lab, Hatfield Marine Sci Ctr, Newport, OR 97265 USA. RP Dziak, RP (reprint author), Oregon State Univ, NOAA, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. NR 12 TC 21 Z9 21 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 DEC 15 PY 1999 VL 26 IS 24 BP 3641 EP 3644 DI 10.1029/1999GL002326 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 271JQ UT WOS:000084590800016 ER PT J AU Resing, JA Feely, RA Massoth, GJ Baker, ET AF Resing, JA Feely, RA Massoth, GJ Baker, ET TI The water-column chemical signature after the 1998 eruption of Axial Volcano SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FLOW-INJECTION-ANALYSIS; SPECTROPHOTOMETRIC DETECTION; HYDROTHERMAL FLUIDS; SEAWATER; PRECONCENTRATION; RIDGE; SEA AB The eruption of Axial Volcano in January 1998 produced extensive plumes in the overlying water column with large anomalies in Fe, Mn, pH, light attenuation, and temperature. A strong correlation between total iron and light attenuation (dc) suggests a low abundance of particulate sulfur (PS) in the plumes. Because total carbon dioxide (Sigma CO2) samples were not collected, high-precision pH measurements were used to estimate maximum CO2 anomalies (Delta CO2) which, when compared to the other physical and chemical data, suggest that the fluids being vented 3 weeks after eruption were formed by the interaction between an intruded dike and a mixture of interstitial seawater and mature hydrothermal fluids. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Resing, JA (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 16 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 15 PY 1999 VL 26 IS 24 BP 3645 EP 3648 DI 10.1029/1999GL002350 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 271JQ UT WOS:000084590800017 ER PT J AU Feely, RA Baker, ET Lebon, GT Gendron, JF Resing, JA Cowen, JP AF Feely, RA Baker, ET Lebon, GT Gendron, JF Resing, JA Cowen, JP TI Evidence for iron and sulfur enrichments in hydrothermal plumes at Axial Volcano following the January-February 1998 eruption SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DE-FUCA RIDGE; SITE; EVENT; RISE AB In response to 12 days of seismic activity at Axial Volcano, Juan de Fuca Ridge in January-February 1998, the NSF/NOAA-sponsored Axial Response Team conducted three response cruises in February, August, and August/September to map and sample hydrothermal plumes over the region. Vertical profiles of particulate Fe and S over the eruption site show high concentrations from about 1400 m to the bottom. Chemical and scanning electron microscope analysis of the February plume samples revealed anhydrite, Fe-ferrihydrites, elemental sulfur, and angular glassy basalt shards up to 190 mu m in the longest dimension. Many of these shards had halite coatings, which is consistent with subseafloor basalt seawater reactions at temperatures >450 degrees C at 1500 m depth. In August and September cruises the basalt shards were no longer present in the hydrothermal plumes. Instead, the plumes were predominantly composed of Fe-ferrihydrites, elemental sulfur, and sulfur filaments. A unique feature of this data set is the high concentrations of elemental sulfur in the lower 60 m of the water column. The sulfur results are suggestive of a significant enrichment of the bacterial biomass in the water column over the eruption site with time. Within the Axial caldera, approximately 10-20% of the total sulfur is present as sulfur filaments. These posteruption particle compositional changes have strong similarities to the results from the 1993 CoAxial eruption on the Juan de Fuca Ridge. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii, Dept Oceanog, SOEST, Honolulu, HI 96822 USA. RP Feely, RA (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 15 TC 17 Z9 17 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 DEC 15 PY 1999 VL 26 IS 24 BP 3649 EP 3652 DI 10.1029/1999GL002325 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 271JQ UT WOS:000084590800018 ER PT J AU Zhang, YY Feng, SC Wang, XK Tian, WS Wu, RR AF Zhang, YY Feng, SC Wang, XK Tian, WS Wu, RR TI Object oriented manufacturing resource modelling for adaptive process planning SO INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH LA English DT Article ID INTEGRATION; MANAGEMENT; FRAMEWORK; SYSTEM AB Computer-aided process planning (CAPP) performs an important function, integrating product design with production, but has not kept pace with CAD/CAM developments. More and more attention has been paid to CAPP automation, intelligence and CAD/CAPP/CAM integration, and a plethora of prototype systems has been developed. However, CAPP applications are less than satisfactory. With the objective of improving CAPP usability and adaptability, this paper proposes object-oriented manufacturing resources modelling (OOMRM) and agent-based process planning (AAPP). The OOMRM exceeds the framework of traditional manufacturing resource databases. It describes manufacturing resources capability and capacity in an object-oriented manner, which intends to encapsulate manufacturing system knowledge and the methods of using the knowledge. Based on the OOMRM, an AAPP prototype is implemented as a man-machine integrated process planning platform. It will support an experienced manufacturing engineer in mapping out a more reasonable and flexible machining process. C1 Worcester Polytech Inst, Dept Mech Engn, Worcester, MA 01609 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Tsing Hua Univ, State CIMS ERC, Beijing 100084, Peoples R China. RP Zhang, YY (reprint author), Worcester Polytech Inst, Dept Mech Engn, 100 Inst Rd, Worcester, MA 01609 USA. NR 32 TC 36 Z9 37 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0020-7543 J9 INT J PROD RES JI Int. J. Prod. Res. PD DEC 15 PY 1999 VL 37 IS 18 BP 4179 EP 4195 DI 10.1080/002075499189727 PG 17 WC Engineering, Industrial; Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 267CP UT WOS:000084337700006 ER PT J AU Rao, CRN Chen, J AF Rao, CRN Chen, J TI Revised post-launch calibration of the visible and near-infrared channels of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-14 spacecraft SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB Records of top-of-the-atmosphere albedo over several sites around the globe indicate that the formulae given in Rao and Chen (1996) to determine the post-launch calibration of the visible (channel I, approximate to 0.58-0.68 mu m) and near-infrared (channel 2, approximate to 0.72-1.1 mu m) channels of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-14 spacecraft overestimate the in-orbit degradation of the two channels, resulting in spurious upward trends in the albedo time series. Therefore, the calibration formulae have been revised to minimize the upward trends, utilizing a 3-year (1995-1997) record of albedo measurements over a calibration site (21-23 degrees N, 28-29 degrees E) in the southeastern Libyan desert. Formulae for the calculation of the revised calibration coefficients as a function of elapsed time in orbit are given. The revised calibration formulae presented here, and those presented in Rao and Chen (1996), yield radiance/albedo values within 5% (relative) of each other for about 900 days after launch in channel 1 and for about 500 days in channel 2. C1 NOAA, NESDIS, Off Res & Applicat, Washington, DC 20233 USA. QSS Grp Inc, Lanham, MD 20706 USA. RP Rao, CRN (reprint author), NOAA, NESDIS, Off Res & Applicat, Washington, DC 20233 USA. NR 8 TC 141 Z9 148 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD DEC 15 PY 1999 VL 20 IS 18 BP 3485 EP 3491 DI 10.1080/014311699211147 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 252BX UT WOS:000083481800004 ER PT J AU Sullivan, J AF Sullivan, J TI New radiance-based method for AVHRR thermal channel nonlinearity corrections SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID HIGH-RESOLUTION RADIOMETER; INFRARED CHANNELS; CALIBRATION AB Thermal channels 4 and 5 of the Advanced Very High Resolution Radiometer (AVHRR) on National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites have an onboard calibration process that provides data from which incoming scene radiance is linearly related to AVHRR count output. However, prelaunch calibration tests show that the radiance is more accurately modelled as a quadratic in count value and that the actual quadratic fit depends upon the operating temperature of the AVHRR itself. NOAA has developed a new method to provide prelaunch information to operational data users that is both concise and accurate. It corrects the linear radiance estimate instead of correcting equivalent blackbody temperature values. The nonlinear correction to the linear radiance estimate is provided by a single quadratic equation, independent of the AVHRR temperature. The new method was first applied to the NOAA-14 AVHRR. hen corrected radiance estimates for the NOAA-14 AVHRR are compared to precise prelaunch data, the rms difference is 0.14 K in channel 4 and 0.08 K in channel 5, in temperature units. At present, users of NOAA-14 AVHRR 1b data have to apply the radiance correction themselves, but for the NOAA-15 and future AVHRRs the necessary information is included in the expanded 1b datastream. Direct readout High Resolution Picture Transmission (HRPT) users have to implement the correction process themselves for NOAA-14, NOAA-15 and future AVHRRs. C1 NOAA, Natl Environm Satellite Data & Informat Serv, CRAD, Washington, DC 20233 USA. RP Sullivan, J (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, CRAD, World Weather Bldg,Rm 712, Washington, DC 20233 USA. NR 5 TC 21 Z9 22 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD DEC 15 PY 1999 VL 20 IS 18 BP 3493 EP 3501 DI 10.1080/014311699211156 PG 9 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 252BX UT WOS:000083481800005 ER PT J AU Rawitscher, GH Esry, BD Tiesinga, E Burke, JP Koltracht, I AF Rawitscher, GH Esry, BD Tiesinga, E Burke, JP Koltracht, I TI Comparison of numerical methods for the calculation of cold atom collisions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RADIAL SCHRODINGER-EQUATION; SPECTRUM AB Comparison between three different numerical techniques for solving a coupled channel Schrodinger equation is presented. The benchmark equation, which describes the collision between two ultracold atoms, consists of two channels, each containing the same diagonal Lennard-Jones potential, one of positive and the other of negative energy. The coupling potential is of an exponential form. The methods are (i) a recently developed spectral type integral equation method based on Chebyshev expansions, (ii) a finite element expansion, and (iii) a combination of an improved Numerov finite difference method and a Gordon method. The computing time and the accuracy of the resulting phase shift is found to be comparable for methods (i) and (ii), achieving an accuracy of ten significant figures with a double precision calculation. Method (iii) achieves seven significant figures. The scattering length and effective range are also obtained. (C) 1999 American Institute of Physics. [S0021-9606(99)01347-1]. C1 Univ Connecticut, Dept Phys, Storrs, CT 06268 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Connecticut, Dept Math, Storrs, CT 06268 USA. RP Rawitscher, GH (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06268 USA. RI Esry, Brett/H-7511-2013 OI Esry, Brett/0000-0003-3207-8526 NR 34 TC 20 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1999 VL 111 IS 23 BP 10418 EP 10426 DI 10.1063/1.480431 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 260AY UT WOS:000083927200005 ER PT J AU Misra, DN AF Misra, DN TI Interaction of citric or hydrochloric acid with calcium fluorapatite: Precipitation of calcium fluoride SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE calcium fluoride; citric acid; dissolution; fluorapatite; hydrochloric acid; interaction; precipitation ID HYDROXYAPATITE; ADSORPTION; ENAMEL; IONS AB The interaction of citric acid (H(3)Ci) with calcium fluorapatite(Ca-10, F-2(PO4)(6)) was explored for two reasons: (i) to determine the role of the acid in the dissolution process and hence in the mechanism of tooth fluoridation and (ii) to determine whether there is any formation of calcium citrate. It was found that the concentration of calcium or fluoride ions is not stoichiometric with respect to that of phosphate ions in the solution and the stoichiometric deficiency of the amount of fluoride ions in the solution is twice that of the calcium ions and this demonstrates that some calcium fluoride is precipitated. The interaction may be represented by the following chemical equation (pH approximate to 2.5): Ca10F2(PO4)(6) + 8H(3)Ci --> (10 - x) Ca2+ 2H(2)PO(4)(1-) + 4HPO(4)(2-) + (2 - 2x)F-1- + xCaF(2) + 8H(2)Ci(1-), where x (presently < 1) is related to the amount of CaF2 that has precipitated and may be calculated from the experimental ratio of Ca to P in the solution. In order to establish that the interaction occurs generally with all acids, the reaction of hydrochloric acid with fluoroapatite was studied, and exactly analogous behavior was observed. These facts are also in accord with the solubility of fluorapatite and calcium fluoride. When the amounts of Ca and P in solution are corrected for the precipitated CaF2, the ratio of Ca to P becomes stoichiometric (= 1.67). Preliminary X-ray analysis of the reacted fluorapatite showed that it contained calcium fluoride, The precipitated CaF2 may act as a reservoir for the subsequent fluoridation of the mineral and may inhibit bacterial action in the mouth. The concentration of citrate ions does not change in solution, and no formation of calcium citrate is observed. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Gaithersburg, MD 20899 USA. RP Misra, DN (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Gaithersburg, MD 20899 USA. NR 17 TC 8 Z9 8 U1 2 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD DEC 15 PY 1999 VL 220 IS 2 BP 387 EP 391 DI 10.1006/jcis.1999.6537 PG 5 WC Chemistry, Physical SC Chemistry GA 273NN UT WOS:000084713900025 ER PT J AU Masina, S Philander, SGH AF Masina, S Philander, SGH TI An analysis of tropical instability waves in a numerical model of the Pacific Ocean - 1. Spatial variability of the waves SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MERIDIONAL CURRENT OSCILLATIONS; EASTERN EQUATORIAL PACIFIC; SEASONAL CYCLE; LONG WAVES; DYNAMICS; ATLANTIC; PROPAGATION; CIRCULATION AB Unstable oscillations confined within the mixed layer close to the equator are generated in wind-forced experiments performed in a multilevel general circulation model configured for the tropical Pacific Ocean. The experiments indicate that the waves develop preferentially in the eastern Pacific along the northern temperature front. However, there is clear evidence of a second unstable region along the southern temperature front in the central Pacific. In both regions the instabilities propagate westward, but in the central Pacific their phase speed is considerably smaller. The differences between the wave characteristics in the eastern and central Pacific are closely correlated to the differences in the time mean conditions of the flow. The eastern instabilities have a structure with two peaks in amplitude: one located on the equator and the other a few degrees north of it. Their dispersion characteristics show many similarities to those of tropical instability waves (TIWs) observed in the Pacific Ocean, while the instabilities which grow in the central Pacific do not have any known observed correspondents. We explore the spatial variability of the simulated waves through a wavelet analysis, which provides detailed results on how the period and wavelength of the instabilities change as a function of longitude, latitude, and depth. The wavelet analysis reveals that in the eastern Pacific and close to the surface the TIWs have a phase speed of -48 cm/s, while in the central Pacific they have a phase speed of -11 cm/s. In particular, the change in the phase speed is due to a change in the dominant period of the TIWs: The period of the central Pacific instabilities is considerably longer than the period of the instabilities present in the eastern Pacific. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Masina, S (reprint author), CNR, Ist Sci Atmosfera & Oceano, Via Gobetti 101, I-40129 Bologna, Italy. EM s.masina@isao.bo.cnr.it; gphlder@splash.Princeton.EDU RI Masina, Simona/B-4974-2012 NR 38 TC 26 Z9 27 U1 1 U2 8 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 1999 VL 104 IS C12 BP 29613 EP 29635 DI 10.1029/1999JC900227 PG 23 WC Oceanography SC Oceanography GA 268DT UT WOS:000084399600007 ER PT J AU Masina, S Philander, SGH Bush, ABG AF Masina, S Philander, SGH Bush, ABG TI An analysis of tropical instability waves in a numerical model of the Pacific Ocean - 2. Generation and energetics of the waves SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ZONAL EQUATORIAL CURRENTS; DYNAMICS; FLOWS; CYCLE AB The instability processes which generate unstable waves with characteristics similar to observed tropical instability waves in the Pacific Ocean are examined through a local energy analysis based on deviations from the time mean flow. Numerical experiments indicate that the waves develop preferentially in the eastern Pacific along the northern temperature front and have a westward phase speed and a structure with two peaks in amplitude: one located on the equator and the other a few degrees north of it. The energy analysis shows that the "two-peak" structure of the eastern waves is explained by two different instability processes which occur at different latitudes. In the time mean sense the region north of the equator is baroclinically unstable, while barotropic instability prevails at the equator. The life cycle of the waves is revealed by the time evolution of the energetics. Baroclinic instability is the dominant triggering mechanism which induces growth of the waves along the northern temperature front. The eddy pressure fluxes radiate energy south of the equator where the meridional shear between the Equatorial Undercurrent and the South Equatorial Current becomes barotropically unstable. From the numerical simulations, there is evidence of a second unstable region in the central Pacific south of the equator where the instabilities have a lower phase speed. The energy analysis also shows that these waves grow from both barotropic and baroclinic conversions. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Masina, S (reprint author), CNR, Ist Sci Atmosfera & Oceano, Via Gobetti 101, I-40129 Bologna, Italy. RI Masina, Simona/B-4974-2012 NR 26 TC 44 Z9 45 U1 1 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 1999 VL 104 IS C12 BP 29637 EP 29661 DI 10.1029/1999JC900226 PG 25 WC Oceanography SC Oceanography GA 268DT UT WOS:000084399600008 ER PT J AU Stabeno, PJ Van Meurs, P AF Stabeno, PJ Van Meurs, P TI Evidence of episodic on-shelf flow in the southeastern Bering Sea SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CURRENTS; SLOPE; CIRCULATION; ADJUSTMENT; EDDY AB Trajectories from satellite-tracked drifters released over the continental slope (depth 250-500 m) in the southeastern Bering Sea revealed an episodic event of on-shelf flow. The first set of seven drifters followed the isobaths northwestward at speeds of 20-40 cm s(-1); the second set, released 12 days later, moved 60 km onto the shelf at speeds of 10-15 cm s(-1). Meanders or eddies were evident in the trajectories as the drifters were advected onto the shelf. An anticyclonic eddy formed at the shoreward termination of on-shelf flow (120 m isobath). The eddy dissipated in 8-10 days. Such events can be important mechanisms in replenishing nutrients and introducing oceanic plankton and larvae onto the shelf. C1 NOAA, Pacific Marine Environm Lab, Coastal & Arctic Res Div, Seattle, WA 98115 USA. RP Stabeno, PJ (reprint author), NOAA, Pacific Marine Environm Lab, Coastal & Arctic Res Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 20 TC 35 Z9 36 U1 1 U2 3 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 1999 VL 104 IS C12 BP 29715 EP 29720 DI 10.1029/1999JC900242 PG 6 WC Oceanography SC Oceanography GA 268DT UT WOS:000084399600012 ER PT J AU Feingold, G Cotton, WR Kreidenweis, SM Davis, JT AF Feingold, G Cotton, WR Kreidenweis, SM Davis, JT TI The impact of giant cloud condensation nuclei on drizzle formation in stratocumulus: Implications for cloud radiative properties SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MARINE BOUNDARY-LAYER; NUMERICAL SIMULATIONS; TRANSITION EXPERIMENT; MODEL; AEROSOL; ASTEX; ENTRAINMENT; COALESCENCE; PARTICLES; EXCHANGE AB The impact of giant and ultragiant cloud condensation nuclei (>5-mu m radius) on drizzle formation in stratocumuli is investigated within a number of modeling frameworks. These include a simple box model of collection, a trajectory ensemble model (comprising an ensemble of Lagrangian parcel models), a 2D eddy-resolving model, and a 3D large-eddy simulation model. Observed concentrations of giant cloud condensation nuclei (GCCN) over the ocean at ambient conditions indicate that 20-mu m radius haze particles exist in concentrations of between 10(-4) and 10(-2) cm(-3), depending on ambient wind speed and seastate. It is shown that these concentrations are sufficient to move a nonprecipitating stratocumulus into a precipitating state at typical cloud condensation nucleus (CCN) concentrations of 50 to 250 cm(-3), with higher concentrations of GCCN being required at higher CCN concentrations. However, at lower CCN concentrations, drizzle is often active anyway and the addition of GCCN has little impact. At high CCN concentrations, drizzle development is slow and GCCN have the greatest potential for enhancing the collection process. Thus, although drizzle production decreases with increasing CCN concentration, the relative impact of GCCN increases with increasing CCN concentration. It is also shown that in the absence of GCCN, a shift in the modal radius of the CCN distribution to larger sizes suppresses drizzle because larger modal radii enable the activation of larger droplet number concentrations. Finally, calculations of the impact of GCCN on cloud optical properties are performed over a range of parameter space. Results indicate that the presence of GCCN moderates the effect of CCN on optical properties quite significantly. In the absence of GCCN, an increase in CCN from 50 to 150 cm(-3) results in a threefold increase in albedo; when GCCN exist at a concentration of 10(-3) cm(-3), the increase in albedo is only twofold. Thus the variable presence of GCCN represents yet another uncertainty in estimating the influence of anthropogenic activity on climate. C1 NOAA, CIRA, Environm Technol Lab, Boulder, CO 80303 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Feingold, G (reprint author), NOAA, CIRA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 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 39 TC 174 Z9 184 U1 0 U2 22 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 15 PY 1999 VL 56 IS 24 BP 4100 EP 4117 DI 10.1175/1520-0469(1999)056<4100:TIOGCC>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267KX UT WOS:000084358100003 ER PT J AU Ledbetter, H Dunn, ML AF Ledbetter, H Dunn, ML TI Habit planes, inclusion theory, and twins SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Martensitic Transformations CY DEC 07-11, 1998 CL SAN CARLOS BARILO, ARGENTINA SP Fdn Antorchas, Consejo Nacl Invest Cient Tecnicas, Inst Invest Cient & Tecnicas Fuerzas Armadas DE crystallography; habit plane; inclusion theory; invariant-plane-strain theory; martensite; steel; twins ID MINIMIZATION; ENERGY AB This study follows a previous one by the authors, who calculated martensite habit planes by two methods: (1) invariant-plane strain based on a theory proposed by Wechsler-Lieberman-Read (WLR) and Bowles-Mackenzie (BM) and (2) elastic-strain energy minimization of a thin-disc inclusion based on a theory similar to those described by Eshelby, Mura, Khachaturyan, and others. Our previous study considered three example materials (In-TI, Au-Cd, Fe-Ni) but neglected twins. The present study introduces twins. Our model contains specifically the twinning plane, often (011)(A), and the WLR angle phi, the relative rigid-body rotation to ensure twin-interface coherency. We focused on the much-studied f.c.c.-b.c.c. transition in Fe-31Ni. Using inclusion theory, we found that the two-Bain-strain (twinned) theory gives much better agreement with invariant-plane-strain theory calculations and with observation than did the twin-free theory. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. RP Ledbetter, H (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, 325 Broadway, Boulder, CO 80303 USA. EM ledbetter@boulder.nist.gov OI DUNN, MARTIN/0000-0002-4531-9176 NR 23 TC 11 Z9 12 U1 0 U2 5 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 1999 VL 273 SI SI BP 222 EP 225 DI 10.1016/S0921-5093(99)00375-5 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 270WP UT WOS:000084560400025 ER PT J AU Schwarz, FP Robinson, S Butler, JM AF Schwarz, FP Robinson, S Butler, JM TI Thermodynamic comparison of PNA/DNA and DNA/DNA hybridization reactions at ambient temperature SO NUCLEIC ACIDS RESEARCH LA English DT Article ID PEPTIDE NUCLEIC-ACID; DNA DUPLEX STABILITY; CIRCULAR-DICHROISM; MASS-SPECTROMETRY; PNA; SEQUENCE; SINGLE; CONFORMATION; BINDING; STRAND AB The thermodynamics of 13 hybridization reactions between 10 base DNA sequences of design 5'-ATGCXYATGC-3' with X, Y = A, C, G, T and their complementary PNA and DNA sequences were determined from isothermal titration calorimetry (ITC) measurements at ambient temperature. For the PNA/DNA hybridization reactions, the binding constants range from 1.8 x 10(6) M-1 for PNA(TT)/DNA to 4.15 x 10(7) M-1 for PNA(GA)/DNA and the binding enthalpies range from -194 kJ mol(-1) for PNA(CG)/DNA to -77 kJ mol(-1) for PNA(GT)/DNA. For the corresponding DNA/ DNA binding reactions, the binding constants range from 2.9 x 10(5) M-1 for DNA(GT)/DNA to 1.9 x 10(7) M-1 for PNA(GA)/DNA and the binding enthalpies range from -223 kJ mol(-1) for DNA(CG)/DNA to -124 kJ mol(-1) for DNA(TT)/DNA. Most of the PNA sequences exhibited tighter binding affinities than their corresponding DNA sequences resulting from smaller entropy changes in the PNA/DNA hybridization reactions. van't Hoff enthalpies and extrapolated Delta G values determined from UV melting studies on the duplexes exhibited closer agreement with the ITC binding enthalpies and Delta G values for the, DNA/DNA duplexes than for the PNA/DNA duplexes. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Schwarz, FP (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Butler, John/C-7812-2011 NR 41 TC 38 Z9 38 U1 3 U2 18 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 15 PY 1999 VL 27 IS 24 BP 4792 EP 4800 DI 10.1093/nar/27.24.4792 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 270QN UT WOS:000084547200016 PM 10572180 ER PT J AU Chakrabarti, MC Schwarz, FP AF Chakrabarti, MC Schwarz, FP TI Thermal stability of PNA/DNA and DNA/DNA duplexes by differential scanning calorimetry SO NUCLEIC ACIDS RESEARCH LA English DT Article ID PEPTIDE NUCLEIC-ACID; DNA; THERMODYNAMICS; PNA AB Thermodynamics of the thermal dissociation transitions of 10 bp PNA/DNA duplexes and their corresponding DNA/DNA duplexes in 10 mM sodium phosphate buffer (pH 7.0) were determined from differential scanning calorimetry (DSC) measurements. The PNA/DNA transition temperatures ranged from 329 to 343 K and the calorimetric transition enthalpies ranged from 209 +/- 6 to 283 +/- 37 kJ mol(-1). The corresponding DNA/DNA transition temperatures were 7-20 K lower and the transition enthalpies ranged from 72 +/- 29 to 236 +/- 24 kJ mol(-1). Agreement between the DSC and UV monitored melting (UVM) determined transition enthalpies validated analyzing the UVM transitions in terms of a two-state transition model. The transitions exhibited reversibility and were analyzed in terms of an AB = A + B two-state transition model which yielded van't Hoff enthalpies in agreement with the transition enthalpies. Extrapolation of the transition enthalpies and free energy changes to ambient temperatures yielded more negative values than those determined directly from isothermal titration calorimetry measurements on formation of the duplexes. This discrepancy was attributed to thermodynamic differences in the single-strand structures at ambient and at the transition temperatures, as indicated by UVM measurements on single DNA and PNA strands. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Schwarz, FP (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 15 TC 35 Z9 36 U1 0 U2 8 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 15 PY 1999 VL 27 IS 24 BP 4801 EP 4806 DI 10.1093/nar/27.24.4801 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 270QN UT WOS:000084547200017 PM 10572181 ER PT J AU Ye, J Hall, JL AF Ye, J Hall, JL TI Optical phase locking in the microradian domain: potential applications to NASA spaceborne optical measurements SO OPTICS LETTERS LA English DT Article AB We have constructed and demonstrated a high-performance optical phase-locked loop between two cw Nd:YAG lasers. The feedback system is relatively simple, employing only the laser's internal piezoelectric transducer and an external acousto-optic modulator. A residual phase noise of the order of 1 mu rad between two optical fields is achieved in the locked condition, as is verified by time- and frequency-domain analyses by the two-oscillator approach that is conventionally used in rf measurement. Potential applications to NASA space-based optical measurements are discussed. (C) 1999 Optical Society of America OCIS codes: 120.0120, 120.4640, 120.5050, 140.3530, 350.5030. 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. EM ye@jila.colorado.edu RI Ye, Jun/C-3312-2011 NR 8 TC 28 Z9 29 U1 1 U2 13 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 EI 1539-4794 J9 OPT LETT JI Opt. Lett. PD DEC 15 PY 1999 VL 24 IS 24 BP 1838 EP 1840 DI 10.1364/OL.24.001838 PG 3 WC Optics SC Optics GA 269TL UT WOS:000084493600016 PM 18079948 ER PT J AU Williams, RM Kelly, JF Hartman, JS Sharpe, SW Taubman, MS Hall, JL Capasso, F Gmachl, C Sivco, DL Baillargeon, JN Cho, AY AF Williams, RM Kelly, JF Hartman, JS Sharpe, SW Taubman, MS Hall, JL Capasso, F Gmachl, C Sivco, DL Baillargeon, JN Cho, AY TI Kilohertz linewidth from frequency-stabilized mid-infrared quantum cascade lasers SO OPTICS LETTERS LA English DT Article ID SPECTROSCOPY; PHASE AB Frequency stabilization of mid-IR quantum cascade (QC) lasers to the kilohertz level has been accomplished by use of electronic servo techniques. With this active feedback, an 8.5-mu m QC distributed-feedback laser is locked to the side of a rovibrational resonance of nitrous oxide (N2O) at 1176.61 cm(-1). A stabilized frequency-noise spectral density of 42 Hz/root Hz has been measured at 100 kHz; the calculated laser linewidth is 12 kHz. (C) 1999 Optical Society of America OCIS codes: 000.2170, 120.5050, 120.4820, 140.5960, 000.2170. C1 Pacific NW Lab, Richland, WA 99352 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Williams, RM (reprint author), Pacific NW Lab, MS K5-25,POB 999, Richland, WA 99352 USA. NR 15 TC 82 Z9 82 U1 0 U2 10 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 DEC 15 PY 1999 VL 24 IS 24 BP 1844 EP 1846 DI 10.1364/OL.24.001844 PG 3 WC Optics SC Optics GA 269TL UT WOS:000084493600018 PM 18079950 ER PT J AU Ravishankara, AR Longfellow, CA AF Ravishankara, AR Longfellow, CA TI Reactions on tropospheric condensed matter SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Annual Meeting of the Deutsche-Bunsen-Gesellschaft-for-Physical-Chemistry CY MAY 13-15, 1999 CL DORTMUND, GERMANY ID MARINE BOUNDARY-LAYER; NITRIC-ACID TRIHYDRATE; SEA-SALT PARTICLES; HETEROGENEOUS REACTION; ICE SURFACES; GAS-PHASE; STRATOSPHERIC AEROSOL; MULTIPHASE CHEMISTRY; REMOTE TROPOSPHERE; CHEMICAL-KINETICS AB Reactions on/in condensed media play important roles in the chemistry of the troposphere. These reactions can be classified as heterogeneous reactions, those occurring on the surfaces of solids, and multiphase reactions, those occurring inside a liquid droplet. A few general considerations in the treatment of heterogeneous and multiphase reactions are discussed. Based on the knowledge and experience obtained from the study of stratospheric heterogeneous and multiphase reactions, possible characteristics of such processes in the troposphere are described and illustrated using a few examples. It is noted that the variety of condensed media in the troposphere makes this a rich field for investigation. The possible importance of reduction reactions in the oxidizing atmosphere is examined. The reactions on soot are highlighted and the potential importance of reactions on organic aerosol and other media is discussed. Finally, the outlook for progress in this area is very briefly discussed. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Ravishankara, AR (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 95 TC 36 Z9 39 U1 1 U2 8 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI PCCP Phys. Chem. Chem. Phys. PD DEC 15 PY 1999 VL 1 IS 24 BP 5433 EP 5441 DI 10.1039/a905660b PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 282WA UT WOS:000085242400007 ER PT J AU Rodriguez, H Valentine, MR Holmquist, GP Akman, SA Termini, J AF Rodriguez, H Valentine, MR Holmquist, GP Akman, SA Termini, J TI Mapping of peroxyl radical induced damage on genomic DNA SO BIOCHEMISTRY LA English DT Article ID FATTY-ACID COMPOSITION; LIPID-PEROXIDATION; ESCHERICHIA-COLI; ELECTRON-TRANSFER; ALKALINE ELUTION; OXYGEN; OXIDATION; MUTAGENESIS; 8-HYDROXYGUANINE; POLYNUCLEOTIDES AB We have examined the DNA damage produced by reaction of peroxyl radicals with human fibroblast DNA. DNA damage consisted of both strand breaks and base modifications. The extent of strand breaks and base modifications induced as a function of peroxyl radical concentration was determined by quantitation of fragment size distributions using denaturing glyoxal-agarose gel electrophoresis. Both strand breaks and base modifications increased in a log linear fashion with respect to peroxyl radical concentration. Oxidative base modifications were observed to occur to a greater extent than strand breaks at every concentration measured. The sequence-specific distribution of peroxyl radical induced base damage was mapped for 803 nucleotide positions using the method of ligation mediated PCR. A total of 87% of all guanine positions in the examined sequences was found to be significantly oxidized. The order of reactivity of DNA bases toward oxidation by peroxyl radicals was found to be G much greater than C > T. Adenine is essentially unreactive. The yield of oxidative base modifications at guanines and cytosines by peroxyl radicals depends on the exact specification of 5' and 3' flanking bases in a polarity dependent manner. Every guanine in the 5'XGC3' motif was found to be oxidized, where X is any 5' neighbor. In contrast, 5' and 3' purine flanks drastically reduced the extent of peroxyl radical G oxidation. The pattern of base modification and the influence of nearest neighbors differs substantially from that previously reported for hydrogen peroxide damage mediated by low valent transition metal ions for the identical DNA sequences. C1 City Hope Natl Med Ctr, Beckman Res Inst, Div Biol, Duarte, CA 91010 USA. NIST, Div Biotechnol, DNA Technol Grp, Gaithersburg, MD 20899 USA. Comprehens Canc Ctr Wake Forest, Dept Canc Biol, Winston Salem, NC 27157 USA. RP Termini, J (reprint author), City Hope Natl Med Ctr, Beckman Res Inst, Div Biol, 1450 E Duarte Rd, Duarte, CA 91010 USA. FU NCI NIH HHS [CA69449]; NIGMS NIH HHS [GM53962, GM59219] NR 48 TC 30 Z9 31 U1 1 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 DEC 14 PY 1999 VL 38 IS 50 BP 16578 EP 16588 DI 10.1021/bi9918994 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 266FE UT WOS:000084289300020 PM 10600120 ER PT J AU Robertson, LS Law, ME Jones, KS Rubin, LM Jackson, J Chi, P Simons, DS AF Robertson, LS Law, ME Jones, KS Rubin, LM Jackson, J Chi, P Simons, DS TI Correlation of end-of-range damage evolution and transient enhanced diffusion of boron in regrown silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID ION-IMPLANTED SILICON; DEFECTS AB Amorphization of a n-type Czochralski wafer was achieved using a series of Si+ implants of 30 and 120 keV, each at a dose of 1x10(15) cm(2). The Si+ implants produced a 2400 A deep amorphous layer, which was then implanted with 4 keV 1x10(14)/cm(2) B+. Postimplantation anneals were performed in a tube furnace at 750 degrees C, for times ranging from 15 min to 6 h. Secondary ion mass spectrometry was used to monitor the dopant diffusion after annealing. Transmission electron microscopy (TEM) was used to study the EOR defect evolution. Upon annealing, the boron peak showed no clustering, and TED was observed in the entire boron profile. TEM results show that both {311} defects and dislocation loops were present in the EOR damage region. The majority of the {311} defects dissolved in the interval between 15 min and 2 h. Results indicate that {311} defects release interstitials during the time that boron exhibits TED. These results show that there is a strong correlation between {311} dissolution in the EOR and TED in the regrown silicon layer. Quantitative TEM of dislocation loop growth and {311} dissolution indicates that in addition to {311} defects, submicroscopic sources of interstitials may also exist in the EOR which may contribute to TED. (C) 1999 American Institute of Physics. [S0003-6951(99)03848-6]. C1 Univ Florida, Gainesville, FL 32611 USA. Eaton Corp, Beverly, MA 01915 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Robertson, LS (reprint author), Univ Florida, Gainesville, FL 32611 USA. NR 13 TC 19 Z9 19 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 13 PY 1999 VL 75 IS 24 BP 3844 EP 3846 DI 10.1063/1.125475 PG 3 WC Physics, Applied SC Physics GA 265KF UT WOS:000084242600036 ER PT J AU Ye, J Vernooy, DW Kimble, HJ AF Ye, J Vernooy, DW Kimble, HJ TI Trapping of single atoms in cavity QED SO PHYSICAL REVIEW LETTERS LA English DT Article ID OPTICAL CAVITY AB By integrating the techniques of laser cooling and trapping with those of cavity quantum electrodynamics (QED), single cesium atoms have been trapped within the mode of a small, high finesse optical cavity in a regime of strong coupling. The observed lifetime for individual atoms trapped within the cavity mode is tau approximate to 28 ms, and is limited by fluctuations of light forces arising from the far-detuned intracavity field. This initial realization of trapped atoms in cavity QED should enable diverse protocols in quantum information science. C1 CALTECH 12 33, Norman Bridge Lab Phys, Pasadena, CA 91125 USA. RP Ye, J (reprint author), Univ Colorado, NIST, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011 NR 22 TC 273 Z9 282 U1 0 U2 15 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 13 PY 1999 VL 83 IS 24 BP 4987 EP 4990 DI 10.1103/PhysRevLett.83.4987 PG 4 WC Physics, Multidisciplinary SC Physics GA 263YC UT WOS:000084152000020 ER PT J AU Meyer, A Busch, R Schober, H AF Meyer, A Busch, R Schober, H TI Time-temperature superposition of structural relaxation in a viscous metallic liquid SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERCOOLED LIQUIDS; DYNAMICS; MOTION; ALLOYS AB Bulk metallic glass-forming Pd40Ni10Cu30P20 has been investigated in its equilibrium liquid by quasielastic neutron scattering. The quasielastic signal exhibits a structural relaxation as known from nonmetallic viscous liquids. Even well above the melting point, the structural relaxation is nonexponential and obeys a universal time-temperature superposition. From the mean relaxation times average diffusivities have been determined, resulting in values on a 10(-10) m(2) s(-1) scale, 3 orders of magnitude slower than in simple metallic liquids. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. CALTECH, WM Keck Labs Engn Mat, Pasadena, CA 91125 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Tech Univ Munich, Dept Phys, D-85747 Garching, Germany. RP Meyer, A (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Meyer, Andreas/F-6260-2013 NR 17 TC 72 Z9 76 U1 2 U2 19 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 13 PY 1999 VL 83 IS 24 BP 5027 EP 5029 DI 10.1103/PhysRevLett.83.5027 PG 3 WC Physics, Multidisciplinary SC Physics GA 263YC UT WOS:000084152000030 ER PT J AU Wiese, WL Kelleher, DE AF Wiese, WL Kelleher, DE TI Atomic spectra databases on the World Wide Web: an update SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wiese, WL (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8420, Gaithersburg, MD 20899 USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD DEC 13 PY 1999 VL 54 IS 13 BP 1769 EP 1770 DI 10.1016/S0584-8547(99)00113-5 PG 2 WC Spectroscopy SC Spectroscopy GA 264FE UT WOS:000084169300001 ER PT J AU Kim, DK Jung, YG Peterson, IM Lawn, BR AF Kim, DK Jung, YG Peterson, IM Lawn, BR TI Cyclic fatigue of intrinsically brittle ceramics in contact with spheres SO ACTA MATERIALIA LA English DT Article DE structural ceramics; fracture; fatigue; yeild phenomena; microstructure ID HETEROGENEOUS GRAIN-STRUCTURE; STRENGTH DEGRADATION; HERTZIAN CONTACTS; CRACK-PROPAGATION; SILICON-NITRIDE; MECHANICAL CHARACTERIZATION; POLYCRYSTALLINE CERAMICS; INDENTATION FRACTURE; DAMAGE ACCUMULATION; DYNAMIC FATIGUE AB Contact damage modes in cyclic loading with spheres are investigated in three nominally brittle ceramics, soda-lime glass, porcelain and fine-grain silicon nitride, in moist environments. Initial damage at small numbers of cycles and low loads consists of tensile-driven macroscopic cone cracks ("brittle" mode). Secondary damage at large numbers of cycles and high loads consists of shear-driven distributed microdamage ("quasi-plastic" mode), with attendant radial cracks and a new form of deeply penetrating subsidiary cone cracks. Strength tests on indented specimens are used to quantify the degree of damage. Both damage modes degrade the strength: the first, immediately after cone crack initiation, relatively slowly; the second, after development of radial cracks, much more rapidly. A fracture mechanics model describing the first mode, based on time-integration of slow growth of cone cracks, is presented. This model provides simple power-law relations for the remaining strength in terms of number of cycles and contact load for materials design. Extrapolations of these relations into the quasi-plastic region are shown to be non-conservative, highlighting the need for further understanding of the deleterious quasi-plastic mode in tougher ceramics. Comparison with static contact data indicates a strong mechanical (as opposed to chemical) component in the cyclic fatigue in the quasi-plastic region. Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Lawn, BR (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Kim, Do Kyung/C-2039-2011 OI Kim, Do Kyung/0000-0001-9092-9427 NR 73 TC 68 Z9 70 U1 3 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD DEC 10 PY 1999 VL 47 IS 18 BP 4711 EP 4725 DI 10.1016/S1359-6454(99)00246-3 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 269RW UT WOS:000084492200020 ER PT J AU Heinz, S Begelman, MC AF Heinz, S Begelman, MC TI A shotgun model for gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID TEMPORAL STRUCTURE; REGIONS AB We propose that gamma-ray bursts (GRBs) are produced by a shower of heavy blobs running into circumstellar material at highly relativistic speeds. The gamma-ray emission is produced in the shocks these bullets drive into the surrounding medium. The short-term variability seen in GRBs is set by the slowing-down time of the bullets, while the overall duration of the burst is set by the lifetime of the central engine. A requirement of this model is that the ambient medium be dense, consistent with a strong stellar wind. The efficiency of the burst can be relatively high. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO USA. RP Heinz, S (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 29 TC 20 Z9 20 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 DEC 10 PY 1999 VL 527 IS 1 BP L35 EP L38 DI 10.1086/312391 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265GW UT WOS:000084235000009 ER PT J AU Adams, RM Chen, CC McCarl, BA Weiher, RF AF Adams, RM Chen, CC McCarl, BA Weiher, RF TI The economic consequences of ENSO events for agriculture SO CLIMATE RESEARCH LA English DT Article DE ENSO events; economic effects; agriculture ID EL-NINO; FORECASTS AB Climate is the primary determinant of agricultural productivity. It is believed that in many parts of the world, including the United States, much of the year-to-year variation in climate can be traced to the El Nino-Southern Oscillation phenomenon. In 1997-98 the world experienced a severe El Nino event and this was followed by a strong La Nina in 1998-99. This paper develops estimates of the economic consequences of such events on US agriculture using a stochastic economic model of the US agricultural sector. Both phases result in economic damages to US agriculture-a $1.5 to $1.7 billion loss for El Nino and a $2.2 to $6.5 billion loss for La Nina. The range in these damage estimates reflects assumptions concerning the relationship between yields and ENSO weather patterns and how farmers respond to these potential yield differentials. C1 Oregon State Univ, Dept Agr & Resource Econ, Corvallis, OR 97331 USA. Texas A&M Univ, Dept Agr Econ, College Stn, TX 77843 USA. US Dept Commerce, NOAA, Off Policy & Strateg Planning, Washington, DC 20230 USA. RP Adams, RM (reprint author), Oregon State Univ, Dept Agr & Resource Econ, Corvallis, OR 97331 USA. RI McCarl, Bruce/E-9445-2011 NR 26 TC 24 Z9 24 U1 4 U2 9 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0936-577X J9 CLIMATE RES JI Clim. Res. PD DEC 10 PY 1999 VL 13 IS 3 BP 165 EP 172 DI 10.3354/cr013165 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 289MD UT WOS:000085624800001 ER PT J AU Chavez, FP Strutton, PG Friederich, CE Feely, RA Feldman, GC Foley, DC McPhaden, MJ AF Chavez, FP Strutton, PG Friederich, CE Feely, RA Feldman, GC Foley, DC McPhaden, MJ TI Biological and chemical response of the equatorial Pacific Ocean to the 1997-98 El Nino SO SCIENCE LA English DT Article ID SURFACE PARTIAL-PRESSURE; 40-50 DAY OSCILLATION; SOUTHERN OSCILLATION; WARM POOL; TROPICAL PACIFIC; CARBON-DIOXIDE; SEA; CO2; VARIABILITY; 150-DEGREES-W AB During the 1997-98 El Nino, the equatorial Pacific Ocean retained 0.7 x 10(15) grams of carbon that normally would have been Lost to the atmosphere as carbon dioxide. The surface ocean became impoverished in plant nutrients, and chlorophyll concentrations were the Lowest on record. A dramatic recovery occurred in mid-1998, the system became highly productive, analogous to coastal environments, and carbon dioxide flux out of the ocean was again high. The spatial extent of the phytoplankton bloom that followed recovery from El Nino was the Largest ever observed for the equatorial Pacific. These chemical and ecological perturbations were linked to changes in the upwelling of nutrient-enriched waters. The description and explanation of these dynamic changes would not have been possible without an observing system that combines biological, chemical, and physical sensors on moorings with remote sensing of chlorophyll. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Natl Marine Fisheries Serv, Honolulu Lab, Honolulu, HI 96822 USA. RP Chavez, FP (reprint author), Monterey Bay Aquarium Res Inst, 7700 Sandholdt Rd, Moss Landing, CA 95039 USA. EM chfr@mbari.org RI Strutton, Peter/C-4466-2011; McPhaden, Michael/D-9799-2016 OI Strutton, Peter/0000-0002-2395-9471; NR 50 TC 381 Z9 394 U1 8 U2 73 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 10 PY 1999 VL 286 IS 5447 BP 2126 EP 2131 DI 10.1126/science.286.5447.2126 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 264AK UT WOS:000084157300043 ER PT J AU Parks, HV Leone, SR AF Parks, HV Leone, SR TI Alignment and orientation effects in Sr energy pooling SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID REAGENT APPROACH GEOMETRY; ASSOCIATIVE IONIZATION; ORBITAL ALIGNMENT; VELOCITY DEPENDENCE; ANGULAR-MOMENTUM; POLARIZED ATOMS; CROSS-SECTIONS; COLLISIONS; 4-VECTOR; STRONTIUM AB Alignment and orientation effects in the energy pooling process, Sr(5s5p P-3(1)) + Sr(5s5p P-3(1)) --> Sr(5s5p P-1(1)) + Sr(5s(2) S-1(0)), are studied in a single atomic beam. The Sr atoms are prepared in an aligned initial state with a polarized laser, and alignment information is extracted by observing the fluorescence from the final Sr(5s5p P-1(1)) state as the atoms precess in an applied magnetic field. This allows the dependence of the total energy pooling cross section (integrated over the final state alignment) on the initial state alignment to be almost completely described. A prominent alignment effect is observed. If m(j) represents the component of total electronic angular momentum of a Sr(5s5p P-3(1)) atom along the relative velocity vector of the collision, then the total energy transfer cross section for a particular initial state alignment can be expressed as a sum of the so-called fundamental cross sections, sigma(m1m2) and sigma(m1m2;m'm2'), that describe collisions between the various m(j) states. Here sigma(m1m2) represents the cross section for energy transfer when an atom in state m(1) collides with an atom in state m(2). The cross section sigma(m1m2;m1'm2') represents the contribution to the total cross section from interference when the colliding system is in a superposition of the state m(1) colliding with m(2) and the state m(1)' colliding with m(2)'. It is found that the cross sections sigma(1-1), sigma(00), and sigma(10) as well as the interference terms Re(sigma(00;1-1)) and sigma(01;10) have relatively large values while sigma(11) and sigma(1-1;-11) are small. Coupled with future theoretical work, these results may provide new insights into the dynamics of the curve crossings that lead to energy transfer. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, 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 26 TC 1 Z9 1 U1 0 U2 0 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 9 PY 1999 VL 103 IS 49 BP 10042 EP 10048 DI 10.1021/jp991743d PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 266UM UT WOS:000084318700003 ER PT J AU Frost, GJ Ellison, GB Vaida, V AF Frost, GJ Ellison, GB Vaida, V TI Organic peroxyl radical photolysis in the near-infrared: Effects on tropospheric chemistry SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ATMOSPHERIC CHEMISTRY; REACTION-MECHANISM; ETHANE COMBUSTION; KINETICS; THERMOCHEMISTRY; SPECTROSCOPY; SPECTRA; ENOLS; HO2; OH AB We investigate the effects of near-infrared photolysis of organic peroxyl radicals (RO2) on tropospheric chemistry. We propose that the excitation of an RO2 to its lowest excited electronic state with near-infrared (near-IR) light is followed by intramolecular reactions that produce hydroxyl (OH) or hydroperoxyl (HO2) radicals. Spectra to this low-lying state have recently-been obtained, but absorption cross sections for this electronic transition and yields of the resulting photoproducts have not been directly measured. We suggest a limiting range of cross sections from estimates for the same transition in HO2 and by comparison to other allowed electronic transitions. On the basis of a thermochemical assessment, we propose that OH and an aldehyde are the principal photoproducts of near-IR photolysis of RO2. These photolysis reactions are included in a model of the troposphere with a standard photochemical mechanism and conditions appropriate to remote, rural, and urban locations. Inclusion of RO2 photolysis has a small effect on any of the major tropospheric chemical constituents if lower limit estimates of the absorption cross sections are used. Midrange or upper limit cross section estimates result in significant departures from the currently accepted photochemical scheme. These studies provide a clear need for further measurements of RO2 absorption cross sections and photoproduct yields, which are the principal uncertainties. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Frost, GJ (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Frost, Gregory/I-1958-2013; Vaida, Veronica/N-6069-2014 OI Vaida, Veronica/0000-0001-5863-8056 NR 35 TC 36 Z9 36 U1 1 U2 9 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 9 PY 1999 VL 103 IS 49 BP 10169 EP 10178 DI 10.1021/jp9917547 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 266UM UT WOS:000084318700017 ER PT J AU Sanov, A Sanford, T Butler, LJ Vala, J Kosloff, R Lineberger, WC AF Sanov, A Sanford, T Butler, LJ Vala, J Kosloff, R Lineberger, WC TI Photodissociation dynamics of gas-phase BrICl- and IBr2- anions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FEMTOSECOND PHOTOELECTRON-SPECTROSCOPY; DEPENDENT SCHRODINGER-EQUATION; STIMULATED RAMAN-SCATTERING; COHERENT VIBRATIONAL MOTION; MOLECULAR-DYNAMICS; ULTRAFAST PHOTODISSOCIATION; GEMINATE RECOMBINATION; IMPULSIVE EXCITATION; ELECTRON CORRELATION; SYMMETRY-BREAKING AB This work is the first study of mixed trihalide anions in the gas phase. We report the photochemistry and photodissociation dynamics of BrICl- and IBr2- anions near 400 nm. For BrICl-, two major photodissociation channels yielding IBr- and ICl- products are observed. The photodissociation of IBr2- yields primarily IBr- anion products. No BrCl- and Br-2(-) fragments are formed from BrICl- and IBr2-, respectively, and the parent anions are ascribed linear [Br-I-Cl](-) and [Br-I-Br](-) structures, in agreement with ab initio calculations. The IBr- and ICl- products are produced in highly vibrationally excited states. We observe fragment vibrational coherence in femtosecond pump-probe measurements by probing nascent IBr- via its photodissociation to I- + Br. The IBr- vibrational periods observed in the photodissociation of BrICl- correspond to excitations of similar to 80% of the IBr- dissociation energy (D-o). In IBr2- dissociation, the average vibrational excitation of IBr- is 84-91% of D-o. The high degrees of vibrational excitation raise questions about the effect of the proximity to the dissociation threshold on the dynamics of coherent wave packets. We analyze these dynamics analytically and by means of wave packet simulations and observe smearing of expected wave packet revivals. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Hebrew Univ Jerusalem, Fritz Haber Res Ctr Mol Dynam, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Dept Chem Phys, IL-91904 Jerusalem, Israel. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Kosloff, Ronnie/D-2388-2013 OI Kosloff, Ronnie/0000-0001-6201-2523 NR 63 TC 15 Z9 15 U1 2 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 DEC 9 PY 1999 VL 103 IS 49 BP 10244 EP 10254 DI 10.1021/jp9920803 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 266UM UT WOS:000084318700026 ER PT J AU Tuck, AF Hovde, SJ Profitt, MH AF Tuck, AF Hovde, SJ Profitt, MH TI Persistence in ozone scaling under the Hurst exponent as an indicator of the relative rates of chemistry and fluid mechanical mixing in the stratosphere SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ANTARCTIC VORTEX; ER-2 AIRCRAFT; CLOUDS; EVOLUTION; TRANSPORT; RADICALS; DYNAMICS; WINTER; HOLE AB The observed self-affine fractal behavior of ozone, wind, and temperature in the stratosphere is used to produce an indication of the rate of occurrence of chemistry relative to that of fluid mixing which, unlike the usual method, is independent of an assumed mechanism sequence of elementary chemical steps followed by application of the law of mass action to obtain differential equations describing the temporal and spatial evolution of the reacting gases. Rather, the occurrence of chemistry is deduced from the scaling of the observed variability; it is applied empirically to deduce the presence of chemical processes that are faster than fluid mechanical mixing above an altitude of 19 km during a balloon flight, and in the Antarctic spring, Arctic summer, and Arctic winter during high altitude aircraft flights. The method should apply to any volume of reacting molecules to which the equations of fluid motion apply and for which measurements can be made over a range of scales. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. WMO, CH-1211 Geneva, Switzerland. RP Tuck, AF (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Tuck, Adrian/F-6024-2011 OI Tuck, Adrian/0000-0002-2074-0538 NR 40 TC 11 Z9 11 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 9 PY 1999 VL 103 IS 49 BP 10445 EP 10450 DI 10.1021/jp9915937 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 266UM UT WOS:000084318700051 ER PT J AU Helmerson, K AF Helmerson, K TI Giving a boost to atoms SO NATURE LA English DT Editorial Material C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Helmerson, K (reprint author), Natl Inst Stand & Technol, Atom Phys Div, 100 Bur Dr,Stop 8424, Gaithersburg, MD 20899 USA. RI Helmerson, Kristian/E-3683-2013 NR 7 TC 2 Z9 2 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 9 PY 1999 VL 402 IS 6762 BP 587 EP 588 DI 10.1038/45092 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 264PC UT WOS:000084189800032 ER PT J AU Kunzel, E Faust, B Oelkers, C Weissbach, U Bearden, DW Weitnauer, G Westrich, L Bechthold, A Rohr, J AF Kunzel, E Faust, B Oelkers, C Weissbach, U Bearden, DW Weitnauer, G Westrich, L Bechthold, A Rohr, J TI Inactivation of the urdGT2 gene, which encodes a glycosyltransferase responsible for the C-glycosyltransfer of activated D-olivose, leads to formation of the novel urdamycins I, J, and K SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ANGUCYCLINE ANTIBIOTICS; STREPTOMYCES-FRADIAE; BIOSYNTHETIC GENE; GLUCOSE; DEOXYSUGARS; AQUAYAMYCIN; VENEZUELAE; NARBOMYCIN; PRODUCTS; CLONING AB A targeted search for glycosyltransferase (GT) encoding genes in the gene cluster of the urdamycin A producer Streptomyces fradiae Tu2717 resulted in the discovery of urdGT2, a GT encoding gene located approximately 7 kb downstream of the minimal polyketide synthase (PKS) encoding genes. Subsequent inactivation of this gene created a mutant strain, which produces completely different metabolites than the wild-type strain, consisting of the three new urdamycins I, J, and K. Their structures provide new insight into the important C-glycosyl-transfer step of the urdamycin biosynthetic pathway. The structures indicate that the corresponding gene product UrdGT2. catalyzes the C-glycosyl transfer of activated D-olivose to an angucyclinone precursor, which already bears the angular 12b-OH group. The structures of the new urdamycins could not have arisen without the involvement of substrate flexible post-PKS modifying genes, i.e., glycosyltransferases and oxidoreductases. This work proves that targeted gene disruption experiments can lead to novel biologically active "unnatural" natural products, which arise through a formerly nonactivated shunt pathway. This approach is especially fruitful in work toward antitumor drugs. Urdamycin J shows a good anticancer activity in in vitro tests. C1 Univ Tubingen, Inst Pharmazeut Biol, D-72076 Tubingen, Germany. Med Univ S Carolina, Dept Pharmaceut Sci, Charleston, SC 29425 USA. Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, NOAA, Charleston, SC 29412 USA. RP Bechthold, A (reprint author), Univ Tubingen, Inst Pharmazeut Biol, Morgenstelle 8, D-72076 Tubingen, Germany. RI Rohr, Jurgen/G-5375-2014 OI Rohr, Jurgen/0000-0001-6447-5951 NR 29 TC 50 Z9 52 U1 1 U2 6 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 DEC 8 PY 1999 VL 121 IS 48 BP 11058 EP 11062 DI 10.1021/ja9915347 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 263ZN UT WOS:000084155300004 ER PT J AU Valincius, G AF Valincius, G TI Electrocapillary equations of solid electrodes SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE electrocapillary equations; solid electrodes; surface stress; surface work ID SURFACE STRESS; ADSORPTION; AU(111); GOLD AB The electrocapillary equations and their application to solid electrodes are reviewed. Evidence is presented showing that solid electrodes exhibit two kinds of electrocapillary properties. For plastic deformation or immersion processes, thermodynamic properties of the solid electrodes are consistent with the classical Lippmann equation. For elastic processes, thermodynamic properties are inter-related by; the Gokhshtein equation that accounts for the influence of elastic strain on a solid electrode's charge density. The latter equation predicts the difference between the potential of zero charge and the potential of the maximum ni the electrocapillary curve. For solid metals, the presence of the electronic dipole layer is the primary reason for the difference between these two points. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Vilnius State Univ, Dept Phys Chem, LT-2006 Vilnius, Lithuania. RP Valincius, G (reprint author), NIST, 100 Bur Dr,Stop 8312, Gaithersburg, MD 20899 USA. NR 44 TC 39 Z9 40 U1 2 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD DEC 6 PY 1999 VL 478 IS 1-2 BP 40 EP 49 DI 10.1016/S0022-0728(99)00411-8 PG 10 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 326XG UT WOS:000087762100006 ER PT J AU Abdurashitov, JN Bowles, TJ Cherry, ML Cleveland, BT Davis, R Elliott, SR Gavrin, VN Girin, SV Gorbachev, VV Ibragimova, TV Kalikhov, AV Khairnasov, NG Knodel, TV Lande, K Mirmov, IN Nico, JS Shikhin, AA Teasdale, WA Veretenkin, EP Vermul, VM Wark, DL Wildenhain, PS Wilkerson, JF Yants, VE Zatsepin, GT AF Abdurashitov, JN Bowles, TJ Cherry, ML Cleveland, BT Davis, R Elliott, SR Gavrin, VN Girin, SV Gorbachev, VV Ibragimova, TV Kalikhov, AV Khairnasov, NG Knodel, TV Lande, K Mirmov, IN Nico, JS Shikhin, AA Teasdale, WA Veretenkin, EP Vermul, VM Wark, DL Wildenhain, PS Wilkerson, JF Yants, VE Zatsepin, GT CA SAGE Collaboration TI Measurement of the solar neutrino capture rate by SAGE and implications for neutrino oscillations in vacuum SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUX AB The Russian-American solar neutrino experiment has measured the capture rate of neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. Eight years of measurement give the result 67.2(-7.0-3.0)(+7.2+3.5) solar neutrino units, where the uncertainties are statistical and systematic, respectively. The restrictions these results impose on vacuum neutrino oscillation parameters are given. C1 Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Univ Penn, Philadelphia, PA 19104 USA. Univ Washington, Seattle, WA 98195 USA. NIST, Gaithersburg, MD 20899 USA. RP Abdurashitov, JN (reprint author), Russian Acad Sci, Inst Nucl Res, 60th October Anniversary Prospect 7, Moscow 117312, Russia. RI Abdurashitov, Dzhonrid/B-2206-2014; Yants, Viktor/C-1038-2014; OI Abdurashitov, Dzhonrid/0000-0002-1577-1364; Wilkerson, John/0000-0002-0342-0217 NR 17 TC 151 Z9 151 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 6 PY 1999 VL 83 IS 23 BP 4686 EP 4689 DI 10.1103/PhysRevLett.83.4686 PG 4 WC Physics, Multidisciplinary SC Physics GA 261PU UT WOS:000084018200003 ER PT J AU Killian, TC Kulin, S Bergeson, SD Orozco, LA Orzel, C Rolston, SL AF Killian, TC Kulin, S Bergeson, SD Orozco, LA Orzel, C Rolston, SL TI Creation of an ultracold neutral plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTALLIZED ION PLASMAS; ELASTIC-SCATTERING; METASTABLE XENON; ELECTRONS AB We report the creation of an ultracold neutral plasma by photoionization of laser-cooled xenon atoms. The charge carrier density is as high as 2 X 10(9) cm(-3), and the temperatures of electrons and ions are as low as 100 mK and 10 mu K, respectively. Plasma behavior is evident in the trapping of electrons by the positive ion cloud when the Debye screening length becomes smaller than the size of the sample. We produce plasmas with parameters such that bath elections and ions ale strongly coupled. C1 NIST, Gaithersburg, MD 20899 USA. RP Killian, TC (reprint author), NIST, Gaithersburg, MD 20899 USA. RI Joint Quantum Institute, NIST/UMD/H-4494-2011; rolston, steven/L-5175-2013; Bergeson, Scott/L-8959-2013 OI rolston, steven/0000-0003-1671-4190; Bergeson, Scott/0000-0002-3124-9226 NR 24 TC 309 Z9 315 U1 8 U2 28 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 6 PY 1999 VL 83 IS 23 BP 4776 EP 4779 DI 10.1103/PhysRevLett.83.4776 PG 4 WC Physics, Multidisciplinary SC Physics GA 261PU UT WOS:000084018200026 ER PT J AU Rizzo, ND Silva, TJ Kos, AB AF Rizzo, ND Silva, TJ Kos, AB TI Relaxation times for magnetization reversal in a high coercivity magnetic thin film SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEDIA; VISCOSITY AB We used a magneto-optical Kerr effect microscope to measure 180 degrees magnetization reversal in a high coercivity CoCr10Ta4 thin film subjected to nanosecond field pulses. Exponential magnetization decay occurs for pulse duration t(p) < 10 ns followed by logarithmic decay for t(p) > 10 ns, indicating a crossover from nonequilibrium magnetization relaxation at short t(p) to metastable equilibrium and thermal relaxation for longer t(p). We conclude that the nonequilibrium magnetization relaxation time (tau(n)) and that the average relaxation time of microscopic thermal fluctuations (tau(0)) is tau(n) = tau(0) approximate to 5 ns. C1 Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Rizzo, ND (reprint author), Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RI Silva, Thomas/C-7605-2013 OI Silva, Thomas/0000-0001-8164-9642 NR 28 TC 27 Z9 27 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 6 PY 1999 VL 83 IS 23 BP 4876 EP 4879 DI 10.1103/PhysRevLett.83.4876 PG 4 WC Physics, Multidisciplinary SC Physics GA 261PU UT WOS:000084018200051 ER PT J AU Misra, DN AF Misra, DN TI Adsorption from solutions on synthetic hydroxyapatite: Nonaqueous vs. aqueous solvents SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE adsorption; hydrogen-bonding; hydroxyapatite; hydrophobicity; ion-exchange; reversibility; surface orientation ID DENTAL POLYMER COMPOSITES; COUPLING AGENTS; TOOTH TISSUES; ACIDS; WATER; EXCHANGE; ADHESION; BINDING; SALTS; IONS AB It is useful in restorative dentistry and etiology of bone diseases to know that certain general rules may be derived from a priori considerations of the adsorption of chemicals to synthetic hydroxyapatite (which is the structural prototype of tooth and bone mineral). This article systematically synthesizes the extensive studies on the subject by the author, and rationalizes and extends these rules. Though not a review article, the work of some researchers may not have found an adequate representation here, because they did not determine, in the case of nonaqueous solvents, the reversibility of adsorption; or, in the case of aqueous solvents, the concentration of all constituent ions of the system, thus missing the occurrence of processes other than adsorption. The adsorption of solutes from nonaqueous solvents on hydroxyapatite is mainly regulated by the interplay of hydrogen bonding between adsorbate, adsorbent, and solvent. It does not involve any significant role of ionic nature of the apatite surface, because it is masked by the chemisorbed and physisorbed water. This interplay of hydrogen bonding in conjunction with chemical and structural characteristics of the adsorbed molecules controls their reversibility and the orientation of the adsorbates on the surface. In general, the process map be considered as true adsorption, because Fro other material exchange process is involved, The "adsorption'' of solutes from aqueous solutions generally involves ion-exchange with the apatite surface, and may be affected by the concentrations of potential determining ions (Ca2+, phosphates, H+, etc.) in the solution. The solute in aqueous solution may be removed by two other mechanisms, either by formation of a surface complex or by chemically reacting with calcium or phosphate ions to form a new phase that precipitates out of solution. Therefore, the concentration of calcium and phosphate ions in solution should also be monitored to elucidate the mechanism of the process. Adsorption of polymers seems to be determined primarily by their multiple hydrogen bonding, their relative molar mass, and their ability to self-associate. The hydrogen ion concentration plays a decisive role in each one of the above mechanisms. (C) 1999 John Wiley & Sons, Inc. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Gaithersburg, MD 20899 USA. RP Misra, DN (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Div Polymers, Gaithersburg, MD 20899 USA. NR 45 TC 28 Z9 28 U1 1 U2 11 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD DEC 5 PY 1999 VL 48 IS 6 BP 848 EP 855 DI 10.1002/(SICI)1097-4636(1999)48:6<848::AID-JBM13>3.0.CO;2-M PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 257FQ UT WOS:000083772200013 PM 10556850 ER PT J AU Vinnikov, KY Robock, A Stouffer, RJ Walsh, JE Parkinson, CL Cavalieri, DJ Mitchell, JFB Garrett, D Zakharov, VF AF Vinnikov, KY Robock, A Stouffer, RJ Walsh, JE Parkinson, CL Cavalieri, DJ Mitchell, JFB Garrett, D Zakharov, VF TI Global warming and Northern Hemisphere sea ice extent SO SCIENCE LA English DT Article ID OCEAN ATMOSPHERE MODEL; NATURAL VARIABILITY; TRANSIENT RESPONSES; GRADUAL CHANGES; CLIMATE; CO2 AB Surface and satellite-based observations show a decrease in Northern Hemisphere sea ice extent during the past 45 years. A comparison of these trends to control and transient integrations (forced by observed greenhouse gases and tropospheric sulfate aerosols) from the Geophysical Fluid Dynamics Laboratory and Hadley Centre climate models reveals that the observed decrease in Northern Hemisphere sea ice extent agrees with the transient simulations, and both trends are much Larger than would be expected from natural climate variations. From Long-term control runs of climate models, it was found that the probability of the observed trends resulting from natural climate variability, assuming that the models' natural variability is similar to that found in nature, is Less than 2 percent for the 1978-98 sea ice trends and Less than 0.1 percent for the 1953-98 sea ice trends. Both models used here project continued decreases in sea ice thickness and extent throughout the next century. C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. Meteorol Off, Hadley Ctr Climate Predict & Res, Bracknell RG12 2SZ, Berks, England. NOAA, Climate Predict Ctr, Natl Weather Serv, Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. Arctic & Antarctic Res Inst, St Petersburg 199397, Russia. RP Vinnikov, KY (reprint author), Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. RI Vinnikov, Konstantin/F-9348-2010; Parkinson, Claire/E-1747-2012; Robock, Alan/B-6385-2016 OI Parkinson, Claire/0000-0001-6730-4197; NR 24 TC 253 Z9 268 U1 6 U2 43 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 3 PY 1999 VL 286 IS 5446 BP 1934 EP 1937 DI 10.1126/science.286.5446.1934 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 261HH UT WOS:000084003400045 ER PT J AU Orkin, VL Villenave, E Huie, RE Kurylo, MJ AF Orkin, VL Villenave, E Huie, RE Kurylo, MJ TI Atmospheric lifetimes and global warming potentials of hydrofluoroethers: Reactivity toward OH, UV spectra, and IR absorption cross sections SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PARTIALLY FLUORINATED ETHERS; REACTION-RATE CONSTANTS; GAS-PHASE REACTIONS; HYDROXYL RADICALS; CYCLIC ETHERS; KINETIC DATA; FATE; CHEMISTRY; REPLACEMENTS; COEFFICIENTS AB The rate constants for the reactions of OH radicals with the fluorinated ethers, CHF2-O-CHF2 (HFOC-134) and CF3CH2-O-CH2CF3 (HFOC-356mff), were measured using the flash photolysis resonance fluorescence technique over the temperature range 277-370 K to give the following Arrhenius expressions: k(HFOC-134)(T) = (0.63(-0.16)(+0.20)) x 10(-12) exp{-(1646 +/- 76)/T} cm(3) molecule(-1) s(-1), k(HFOC-356mff)(T) (2.32(-0.41)(+0.46)) x 10(-12): exp{-(790 +/- 47)/T} cm(3) molecule(-1) s(-1). On the basis of the analysis of the available experimental results, the following Arrhenius expression can be recommended for the rate constant of the reaction between OH and HFOC-134: k(HFOC-134)(T) = (0.82(-0.24)(+0.34)) x 10(-12) exp{-(1730 +/- 110)/T} cm(3) molecule(-1) s(-1). Atmospheric lifetimes were estimated to be 24.8 years for HFOC-134 (23.8 years based on the results of this study alone) and 0.3 years for HFOC-356mff. Infrared absorption cross sections of HFOC-134, HFOC-356mff,and HFOC-125 (CHF2-O-CF3) were measured at T = 295 K from 500 to 1600 cm(-1) and the global warming potentials of the three compounds were estimated. Ultraviolet absorption spectra of the ethers were measured between 160 and 220 Mm. The general pattern of reactivity of hydrofluoroethers toward OH is discussed. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Russian Acad Sci, Inst Energy Problems Chem Phys, Moscow 117829, Russia. RP Orkin, VL (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 33 TC 36 Z9 36 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 DEC 2 PY 1999 VL 103 IS 48 BP 9770 EP 9779 DI 10.1021/jp991741t PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 263EX UT WOS:000084113100023 ER PT J AU Hufford, GL Kelley, HL Moore, RK Cotterman, JS AF Hufford, GL Kelley, HL Moore, RK Cotterman, JS TI Detection and growth of an Alaskan forest fire using GOES-9 3.9 mu m imagery SO INTERNATIONAL JOURNAL OF WILDLAND FIRE LA English DT Article DE Alaska; GOES-9; 3.9 mu.m channel; forest fire; fire detection; fire growth; hot spots; management tool; Miller's reach; automated technique ID SATELLITES AB The utility of the new GOES-9 satellite 3.9 mum channel to monitor wildfires and their subsequent changes in growth and intensity in Alaska is examined. The June, 1996 Miller's Reach forest fire is presented as a case study. Eighteen hours of sequential imagery coincident to the initiation and early stages of the fire are analyzed for hot spots. The dramatic response of the 3.9 mum channel to sub-pixel hot spots and the ability to access the data every 15 minutes makes the channel an effective tool to support forest fire management on wildfires in high latitudes to at least 61 degrees N. In the case of Miller's Reach, the fire was detected when it was less than 200 hectares in size. Changes in fire growth and intensity were also observed. An automated technique for decision makers which classifies hot spots without requiring image interpretation is proposed. C1 Natl Weather Serv, Anchorage, AK 99513 USA. RP Hufford, GL (reprint author), Natl Weather Serv, 222 W 7th Ave, Anchorage, AK 99513 USA. EM gary.hufford@noaa.gov; lee.kelley@noaa.gov; ray.moore@noaa.gov; jeff.cotterman@noaa.gov NR 10 TC 2 Z9 2 U1 0 U2 0 PU CSIRO PUBLISHING PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA SN 1049-8001 J9 INT J WILDLAND FIRE JI Int. J. Wildland Fire PD DEC PY 1999 VL 9 IS 2 BP 129 EP 136 DI 10.1071/WF00017 PG 8 WC Forestry SC Forestry GA 391DU UT WOS:000166339500006 ER PT J AU Levin, I Bendersky, LA AF Levin, I Bendersky, LA TI Symmetry classification of the layered perovskite-derived A(n)B(n)X(3n+2) structures SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID CRYSTAL-STRUCTURE; ELECTRON-MICROSCOPY; PHASES; SR2NB2O7; CA2NB2O7 AB The effects of combinations of octahedral tilts on the symmetries of layered A(n)B(n)X(3n+2) structures were considered. Two complementary approaches were used to deduce the symmetries. The space groups associated with different tilt systems were determined for structures with different layer thicknesses (n values) and for structures with different layer stacking arrangements. For the most symmetrical tilts about the orthorhombic axes of the A(n)B(n)X(3n+2) structure, maximal group/subgroup relations were established. Comparison of these results with experimental data available in the literature suggests that the symmetries of most observed A(n)B(n)X(3n+2) compounds are fully determined by the tilt systems adopted by rigid BX6 octahedra. The most common tilt system observed at room temperature is a combination of an in-phase tilt about an orthorhombic axis parallel to the pseudo-fourfold axis of the octahedron with a tilt about an orthorhombic axis perpendicular to the layers. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Levin, I (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010 NR 47 TC 29 Z9 29 U1 2 U2 16 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Sci. PD DEC 1 PY 1999 VL 55 BP 853 EP 866 DI 10.1107/S0108768199005479 PN 6 PG 14 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 267QL UT WOS:000084370700005 ER PT J AU Davis, RW Moore, EF AF Davis, RW Moore, EF TI Two model problems for testing aerosol dynamics algorithms for stagnation-flow reactors SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION AB Two simple model problems are presented that can be very useful for assessing the accuracy of numerical algorithms designed to solve for aerosol dynamics in stagnation-flow reactors via the moment transport method. These model problems have been simplified to the point that analytical solutions useful for algorithm testing are possible, although complete aerosol solutions are not obtained here. Model problem solutions are presented over a range of applicable parameters. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Davis, RW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD DEC PY 1999 VL 31 IS 6 BP 456 EP 462 DI 10.1080/027868299304002 PG 7 WC Engineering, Chemical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 259GR UT WOS:000083886600005 ER PT J AU Zhang, Y Seigneur, C Seinfeld, JH Jacobson, MZ Binkowski, FS AF Zhang, Y Seigneur, C Seinfeld, JH Jacobson, MZ Binkowski, FS TI Simulation of aerosol dynamics: A comparative review of algorithms used in air quality models SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID REGIONAL AEROSOLS; GROWTH; EVAPORATION; SIZE; URBAN; CONDENSATION AB A comparative review of algorithms currently used in air quality models to simulate aerosol dynamics is presented, This review addresses coagulation, condensational growth, nucleation, and gas/particle mass transfer, Two major approaches are used in air quality models to represent the particle size distribution: (1) the sectional approach in which the size distribution is discretized into sections and particle properties are assumed to be constant over particle size sections and (2) the modal approach in which the size distribution is approximated by several modes and particle properties are assumed to be uniform in each mode. The sectional approach is accurate for coagulation and can reproduce the major characteristics of the evolution of the particle size distribution for condensational growth with the moving-center and hybrid algorithms, For coagulation and condensational growth, the modal approach provides more accurate results when the standard deviations of the modes are allowed to vary than it does when they are fixed. Predictions of H2SO4 nucleation rates are highly sensitive to environmental variables and simulation of relative rates of condensation on existing particles and nucleation is a preferable approach. Explicit treatment of mass transfer is recommended for cases where volatile species undergo different equilibrium reactions in different particle size ranges (e.g., in the presence of coarse salt particles). The results of this study provide useful information for use in selecting algorithms to simulate aerosol dynamics in air quality models and for improving the accuracy of existing algorithms. C1 Atmospher & Environm Res Inc, San Ramon, CA 94583 USA. CALTECH, Pasadena, CA 91125 USA. Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. US EPA, Natl Ocean & Atmospher Adm, Atmospher Modeling Div, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. RP Zhang, Y (reprint author), Atmospher & Environm Res Inc, 2682 Bishop Dr,Suite 120, San Ramon, CA 94583 USA. NR 38 TC 115 Z9 115 U1 1 U2 13 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD DEC PY 1999 VL 31 IS 6 BP 487 EP 514 DI 10.1080/027868299304039 PG 28 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 259GR UT WOS:000083886600008 ER PT J AU Trelles, J McGrattan, KB Baum, HR AF Trelles, J McGrattan, KB Baum, HR TI Smoke dispersion from multiple fire plumes SO AIAA JOURNAL LA English DT Article ID BUOYANCY-DRIVEN PLUMES; COMPUTATIONAL MODEL; STRATIFIED ATMOSPHERE; RISE AB The effects of multiple fire plumes in a stably stratified atmosphere with a uniform wind are investigated. A parabolized approximation of the steady state Navier-Stokes equations obtained by replacing the windward velocity component with the ambient wind speed is the basis of the model. Lagrangian particles are used to visualize the flow, account for atmospheric fluctuations, and determine the smoke concentration field. Multiple-plume interactions can push particulate up to altitudes exceeding that of an equivalent single plume. A parametric study based on separation and heat release rates is performed for two plumes. The most dramatic increases in plume rise and spread are found for in-line plumes, parallel to the wind direction. Multiple-plume interactions can yield nonuniformities in the smoke concentration held that differ substantially from that predicted by Gaussian models. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Trelles, J (reprint author), Hughes Associates Inc, 3610 Commerce Dr,Suite 817, Baltimore, MD 21227 USA. NR 30 TC 5 Z9 5 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1999 VL 37 IS 12 BP 1588 EP 1601 DI 10.2514/2.659 PG 14 WC Engineering, Aerospace SC Engineering GA 263JB UT WOS:000084120600008 ER PT J AU Lehman, J Eppeldauer, G Aust, JA Racz, M AF Lehman, J Eppeldauer, G Aust, JA Racz, M TI Domain-engineered pyroelectric radiometer SO APPLIED OPTICS LA English DT Article AB We built a large-area domain-engineered pyroelectric radiometer with high spatial and spectral response uniformity that is an excellent primary transfer standard for measurements in the near- and the mid-infrared wavelength regions. The domain engineering consisted of inverting the spontaneous polarization over a 10-mm-diameter area in the center of a uniformly poled, 15.5 mm x 15.5 mm square, 0.25-mm-thick LiNbO3 plate. Gold black was used as the optical absorber on the detector surface, and an aperture was added to define the optically sensitive detector area. Our results indicate that we significantly reduced the acoustic sensitivity without loss of optical sensitivity. The detector noise equivalent power was not exceptionally low but was nearly constant for different acoustic backgrounds. In addition, the detector's spatial-response uniformity variation was less than 0.1% across the 7.5-mm-diameter aperture, and reflectance measurements indicated that the gold-black coating was spectrally uniform within 2%, from 800 to 1800 nm. Other detailed evaluations of the detector include detector responsivity as a function of temperature, electrical frequency response, angular response, and field of view. OCIS codes: 040.0040, 120.5630, 230.0230. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. Natl Inst Stand & Technol, Opt Tech Div, Gaithersburg, MD 20899 USA. RP Lehman, J (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. EM lehman@boulder.nist.gov NR 16 TC 22 Z9 22 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 1999 VL 38 IS 34 BP 7047 EP 7055 DI 10.1364/AO.38.007047 PG 9 WC Optics SC Optics GA 261RV UT WOS:000084023500009 PM 18324249 ER PT J AU Lehman, JH Li, X AF Lehman, JH Li, X TI A transfer standard for optical fiber power metrology SO APPLIED OPTICS LA English DT Article ID INFRARED DETECTORS AB We have developed and evaluated a transfer standard for the calibration of optical fiber power meters over the wavelength range from 750-1800 nm. The transfer standard is an optical-trap detector consisting of two germanium (Ge) photodiodes, and a spherical mirror. The photodiodes and mirror are contained in a package that is thermally stable and accepts a variety of optical fiber connectors. Spatial uniformity measurements indicate that the variation of detector response as a function of beam position is less than +/-0.15%. Comparison of the absolute responsivity for three different input conditions indicates that the detector responsivity is nearly the same for collimated beams transmitted through air, as for diverging input from an optical fiber. Small measurement-result differences between collimated and diverging inputs still remain and are discussed briefly. C1 Natl Inst Stand & Technol, Laser Sources & Detectors Grp, Boulder, CO USA. RP Lehman, JH (reprint author), Natl Inst Stand & Technol, Laser Sources & Detectors Grp, 325 Broadway, Boulder, CO USA. NR 9 TC 15 Z9 15 U1 0 U2 1 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 DEC 1 PY 1999 VL 38 IS 34 BP 7164 EP 7166 PG 3 WC Optics SC Optics GA 261RV UT WOS:000084023500029 ER PT J AU Nyden, MR AF Nyden, MR TI Real-time measurements of condensed-phase spectra in burning polymers SO APPLIED SPECTROSCOPY LA English DT Article DE mid-IR fiber-optic probe; flammability measurements; nylon-6; nanocomposites ID FIBER; NANOCOMPOSITES; RETARDANT C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Nyden, MR (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD DEC PY 1999 VL 53 IS 12 BP 1653 EP 1655 DI 10.1366/0003702991946163 PG 3 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 272JU UT WOS:000084647400028 ER PT J AU Hubbard, JD Hansen, DJ Mahoney, BA AF Hubbard, JD Hansen, DJ Mahoney, BA TI Winter sighting of beluga whales (Delphinapterus leucas) in Yakutat-Disenchantment Bay, Alaska SO ARCTIC LA English DT Article DE beluga whale; Delphinapterus leucas; Gulf of Alaska; winter distribution; Yakutat Bay AB On 19 February 1997, we made the first documented winter sighting of beluga whales in Yakutat-Disenchantment Bay, Alaska. We estimated that 10 individuals were swimming in ice-free, turbid water near the Hubbard Glacier. The sporadic record of belugas in the bay suggests they may be occasional visitors from the Cook Inlet population. C1 Minerals Management Serv, Alaska Outer Continental Shelf Reg, Anchorage, AK 99508 USA. Natl Ocean & Atmospher Adm, Natl Marine Fisheries Serv, Anchorage Field Off, Anchorage, AK 99513 USA. RP Hubbard, JD (reprint author), Minerals Management Serv, Alaska Outer Continental Shelf Reg, 949 E 36th Ave, Anchorage, AK 99508 USA. NR 12 TC 1 Z9 1 U1 2 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 1999 VL 52 IS 4 BP 411 EP 412 PG 2 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 269CU UT WOS:000084458900008 ER PT J AU Lo, AKF Zhang, LM Sievering, H AF Lo, AKF Zhang, LM Sievering, H TI The effect of humidity and state of water surfaces on deposition of aerosol particles onto a water surface SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE sub-micron particle dry deposition; humidity effect; water surfaces ID DRY DEPOSITION; LAYER; SEA; MODELS AB Deposition processes of particles with dry diameter larger than about 10 mu m are dominated by gravitational settling, while molecular diffusion and Brownian motion predominate the deposition processes of particles smaller than 0.1 mu m in dry diameter. Many air pollution derived elements exhibit characteristics common to sub-micron particles. The objective of the present study is to examine the effects of meteorological conditions within the turbulent transfer layer on the deposition velocity of particles with dry diameter between 0.1 and 1 mu m. It is for these sub-micron particles that particle growth by condensation in the deposition layer, the broken water surface effect and the enhanced transfer process due to atmospheric turbulence in the turbulent transfer layer play important roles in controlling the particle deposition velocity. Results of the present study show that the 'dry air' assumption of Williams' model is unrealistic. Effects of ambient air relative humidity and water surface temperature cannot be ignored in determining the deposition velocity over a water surface. Neglecting effects of ambient air relative humidity and water surface temperature will result in defining atmospheric stability incorrectly,lt is found that the largest effect of air relative humidity on deposition velocity occurs at an air-water temperature difference corresponding to the point of 'displaced neutral stability', For a given wind speed of U = 5 m s(-1) the additive effects of water surface temperature, T-w, changes from 5 to 25 degrees C and ambient air relative humidity variations from 85 to 60%, respectively, lead to a maximum difference in v(d) of about 20%. For a higher wind speed of 10 m s(-1), however, the corresponding change in v(d) reduces to less than 5%. This is further confirmation that wind speed is one of the strongest variables that governs the magnitude of v(d). The present study also found that the broken surface transfer coeffrcient, k(bs), given as a multiple of the smooth surface transfer coefficient, k(ss), is physically more meaningful than assigning it a constant value independent of particle size. The method used in this study requires only a single level of atmospheric data coupled with the surface temperature measurement. The present method is applicable for determining deposition velocity not only at the conventional measurement height of 10 m but also at any other heights that are different from the measurement height. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Environm Canada, Atomospher Environm Serv, Modelling & Integrat Res Div, Toronto, ON M3H 5T4, Canada. Univ Colorado, Global Change & Environm Qual Prog, Denver, CO 80217 USA. Environm Canada, Atomospher Environm Serv, Dept Environm Sci & Geog, Toronto, ON M3H 5T4, Canada. NOAA, CMDL, Aerosols Grp, Boulder, CO USA. RP Lo, AKF (reprint author), Environm Canada, Atomospher Environm Serv, Modelling & Integrat Res Div, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada. NR 17 TC 7 Z9 7 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1999 VL 33 IS 28 BP 4727 EP 4737 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 247YU UT WOS:000083249200016 ER PT J AU McCurdy, T Zelenka, MP Lawrence, PM Houston, RM Burton, R AF McCurdy, T Zelenka, MP Lawrence, PM Houston, RM Burton, R TI Acid aerosols in the Pittsburgh Metropolitan area SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE acidic sulfate; ammonia; ammonium; ozone; particle strong acid ID NORTHEASTERN UNITED-STATES; PARTICLE STRONG ACIDITY; ATMOSPHERIC AEROSOLS; PERSONAL EXPOSURES; ALLEGHENY MOUNTAIN; AIR-POLLUTION; NEW-YORK; SULFATE; GASES; ORIGINS AB This article presents data on ambient concentrations of selected acidic aerosols at four existing monitoring sites in the Pittsburgh PA metropolitan area, The data were collected by staff of the Allegheny County Health Department, Division of Air Quality during the summer and fall of 1993, The sampling protocol was focused on obtaining 24 h-average ammonia, ammonium, acidic sulfates, and particle strong acids data on a 2 to 3 day cycle. The data were obtained using Harvard University School of Public Health's "Short-HEADS" annular denuder sampling train. The Pittsburgh area is of interest because it is downwind of a major regional source of sulfur and nitrogen emissions from coal-burning power plants: the Ohio River Valley. The data presented here indicate that ground-level concentrations of acidic aerosols in Pittsburgh are highly correlated spatially and that many pollutants are higher on days when ground-level wind direction vectors indicate that wind is coming from the southwest rather than from the Pittsburgh source area itself. The monitoring site that is most upwind of the Pittsburgh source area - South Fayette - has particle strong acid levels about twice those of sites closer in to the Pittsburgh central business district. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 US EPA, Natl Exposure Res Lab, MD 56, Res Triangle Pk, NC 27711 USA. Natl Ocean & Atmospher Adm, Air Resources Lab, MD 56, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. Bur Environm Qual, Allegheny Cty Hlth Dept, Pittsburgh, PA 15201 USA. RP McCurdy, T (reprint author), US EPA, Natl Exposure Res Lab, MD 56, Res Triangle Pk, NC 27711 USA. NR 37 TC 19 Z9 19 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1999 VL 33 IS 30 BP 5133 EP 5145 DI 10.1016/S1352-2310(99)00119-3 PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 263YX UT WOS:000084153800015 ER PT J AU Parrish, DD Ryerson, TB Holloway, JS Trainer, M Fehsenfeld, FC AF Parrish, DD Ryerson, TB Holloway, JS Trainer, M Fehsenfeld, FC TI New Directions: Does pollution increase or decrease tropospheric ozone in Winter-Spring? SO ATMOSPHERIC ENVIRONMENT LA English DT Article C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Parrish, DD (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; 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 0 TC 12 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 1999 VL 33 IS 30 BP 5147 EP 5149 DI 10.1016/S1352-2310(99)00253-8 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 263YX UT WOS:000084153800016 ER PT J AU Parr, RM Kawamura, H Iyengar, GV AF Parr, RM Kawamura, H Iyengar, GV TI Acquisition of improved reference values for cesium, iodine, strontium, thorium, and uranium in selected NIST reference materials SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article; Proceedings Paper CT 1998 International Conference on Nuclear Methods in the Life Sciences (NAMLS) CY OCT 26-30, 1998 CL BEIJING, PEOPLES R CHINA SP China Inst Atom Energy, Int Atom Energy Agcy, Natl Nat Sci Fdn China, China Natl Nucl Corp, Chinese Acad Sci, Inst High Energy Phys, Chinese Nucl Soc DE analytical quality control; cesium; iodine; strontium; thorium; uranium; nuclear analytical techniques; diet; bone; tissues AB As part of a study on the ingestion and organ content of some trace elements of importance in radiological protection, additional work has been undertaken to acquire improved reference values for cesium, iodine, strontium, thorium, and uranium in four selected reference materials provided by the US National Institute of Standards and Technology. The materials are SRM-1548 Total Diet, SRM-1548a Typical Diet, SRM-1486 Bone Meal, and RM-8414 Bovine Muscle. A coordinated study was undertaken with the help of seven selected laboratories in five countries. Instrumental and radiochemical neutron activation analysis and inductively coupled plasma-mass spectrometry were the analytical main techniques used. C1 IAEA, A-1400 Vienna, Austria. Natl Inst Radiol Sci, Hitachinaka, Ibaraki 3111202, Japan. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Parr, RM (reprint author), IAEA, POB 100, A-1400 Vienna, Austria. NR 4 TC 5 Z9 5 U1 0 U2 1 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD WIN PY 1999 VL 71-2 BP 5 EP 13 DI 10.1007/BF02784185 PG 9 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 271TT UT WOS:000084610100002 PM 10676473 ER PT J AU Heller-Zeisler, SF Ondov, JM Zeisler, R AF Heller-Zeisler, SF Ondov, JM Zeisler, R TI Collection and characterization of a bulk PM2.5 air particulate matter material for use in reference materials SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article; Proceedings Paper CT 1998 International Conference on Nuclear Methods in the Life Sciences (NAMLS) CY OCT 26-30, 1998 CL BEIJING, PEOPLES R CHINA SP China Inst Atomic Energy, Int Atom Energy Agcy, Natl Nat Sci Fdn China, China Natl Nucl Corp, Chinese Academy Sci, Inst High Energy Phys, Chinese Nucl Soc DE air particulate matter; PM2.5; reference materials; high-volume sampling; cyclone separation; neutron activation analysis AB A contemporary PM2.5 (particulate matter smaller than 2.5 mu m aerodynamic diameter) aerosol material from an urban site has been collected for the production of a new standard reference material that will be made available for the development of new PM2.5 air quality standards. Air particulate matter corresponding to the PM2.5 fraction was collected at an established Environmental Protection Agency monitoring site in Baltimore, Maryland. The air-sampling system that has been constructed for this collection separates fine particles with a cyclone separator and deposits them onto an array of Teflon membrane filters. The fine air particulate material is removed by ultrasonication or by mechanical means and collected for further preparation of standards. The composition of the collected PM2.5 aerosol, as well as the composition of the deposited PM2.5 aerosol, are determined by instrumental nuclear activation analysis and other techniques. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Heller-Zeisler, SF (reprint author), Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. NR 3 TC 10 Z9 10 U1 2 U2 9 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD WIN PY 1999 VL 71-2 BP 195 EP 202 DI 10.1007/BF02784205 PG 8 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 271TT UT WOS:000084610100022 PM 10676493 ER PT J AU Zeisler, R Greenberg, RR AF Zeisler, R Greenberg, RR TI Determinations of subnanomole elemental levels by NAA and their possible impact on human health related issues SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article; Proceedings Paper CT 1998 International Conference on Nuclear Methods in the Life Sciences (NAMLS) CY OCT 26-30, 1998 CL BEIJING, PEOPLES R CHINA SP China Inst Atomic Energy, Int Atom Energy Agcy, Natl Nat Sci Fdn China, China Natl Nucl Corp, Chinese Academy Sci, Inst High Energy Phys, Chinese Nucl Soc DE neutron activation analysis; chromium; selenium; platinum; human liver; human blood; macromolecules; ultratrace analysis ID TISSUES AB Neutron activation analysis (NAA) is an appropriate tool for the determination of trace elements in biological systems. The virtually blank-free NAA procedures fittingly complement precautions employed in sampling and sample preparation of biological matrices. Results from instrumental NAA procedures used to establish baseline values and time trends for elements in human tissues demonstrate the advantages as well as the limits of these procedures for nanomole and, in a considerable number of instances, subnanomole elemental levels. Ln addition, subnanomole mass fractions have been determined with extremely low limits of detection by employing NAA with radiochemical separations isolating very low levels of radioactivity from the matrix background. The elements reviewed in this article include Cr, Se, Pt, and others that have been determined by NAA at subnanomole levels in human tissues and body fluids and in biological macromolecules. C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Zeisler, R (reprint author), NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD WIN PY 1999 VL 71-2 BP 283 EP 289 DI 10.1007/BF02784214 PG 7 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 271TT UT WOS:000084610100031 PM 10676502 ER PT J AU Akeson, M Branton, D Kasianowicz, JJ Brandin, E Deamer, DW AF Akeson, M Branton, D Kasianowicz, JJ Brandin, E Deamer, DW TI Microsecond time-scale discrimination among polycytidylic acid, polyadenylic acid, and polyuridylic acid as homopolymers or as segments within single RNA molecules SO BIOPHYSICAL JOURNAL LA English DT Article ID ION-CHANNEL; PORE AB Single molecules of DNA or RNA can be detected as they are driven through an oc-hemolysin channel by an applied electric field. During translocation, nucleotides within the polynucleotide must pass through the channel pore in sequential, single-file order because the limiting diameter of the pore can accommodate only one strand of DNA or RNA at a time. Here we demonstrate that this nanopore behaves as a detector that can rapidly discriminate between pyrimidine and purine segments along an RNA molecule. Nanopore detection and characterization of single molecules represent a new method for directly reading information encoded in linear polymers, and are critical first steps toward direct sequencing of individual DNA and RNA molecules. C1 Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA. Harvard Univ, Dept Mol & Cellular Biol, Cambridge, MA 02138 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Akeson, M (reprint author), Univ Calif Santa Cruz, Dept Chem, Santa Cruz, CA 95064 USA. FU NHGRI NIH HHS [HG01826-01] NR 20 TC 631 Z9 634 U1 6 U2 105 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 1999 VL 77 IS 6 BP 3227 EP 3233 PG 7 WC Biophysics SC Biophysics GA 264VG UT WOS:000084203200032 PM 10585944 ER PT J AU Barnett, TP Hasselmann, K Chelliah, M Delworth, T Hegerl, G Jones, P Rasmusson, E Roeckner, E Ropelewski, C Santer, B Tett, S AF Barnett, TP Hasselmann, K Chelliah, M Delworth, T Hegerl, G Jones, P Rasmusson, E Roeckner, E Ropelewski, C Santer, B Tett, S TI Detection and attribution of recent climate change: A status report SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GENERAL-CIRCULATION MODEL; SURFACE-TEMPERATURE; GREENHOUSE-GAS; FINGERPRINT METHOD; ATMOSPHERE; SIGNALS; VARIABILITY; TRENDS; SIMULATION; AEROSOL AB This paper addresses the question of where we now stand with respect to detection and attribution of an anthropogenic climate signal. Our ability to estimate natural climate variability, against which claims of anthropogenic signal detection must be made, is reviewed. The current situation suggests control runs of global climate models may give the best estimates of natural variability on a global basis, estimates that appear to be accurate to within a factor of 2 or 3 at multidecadal timescales used in detection work. Present uncertainties in both observations and model-simulated anthropogenic signals in near-surface air temperature are estimated. The uncertainty in model simulated signals is, in places, as large as the signal to be detected. Two different, but complementary, approaches to detection and attribution are discussed in the context of these uncertainties. Applying one of the detection strategies, it is found that the change in near-surface, June through August air temperature field over the last 50 years is generally different at a significance level of 5% from that expected from model-based estimates of natural variability. Greenhouse gases alone cannot explain the observed change. Two of four climate models forced by greenhouse gases and direct sulfate aerosols produce results consistent with the current climate change observations, while the consistency of the other two depends on which model's anthropogenic fingerprints are used. A recent integration with additional anthropogenic forcings (the indirect effects of sulfate aerosols and tropospheric ozone) and more complete tropospheric chemistry produced results whose signal amplitude and pattern were consistent with current observations, provided the model's fingerprint is used and detection carried out over only the last 30 years of annually averaged data. This single integration currently cannot be corroborated and provides no opportunity to estimate the uncertainties inherent in the results, uncertainties that are thought to be large and poorly known. These results illustrate the current large uncertainty in the magnitude and spatial pattern of the direct and indirect sulfate forcing and climate response. They also show detection statements depend on model-specific fingerprints, time period, and seasonal character of the signal, dependencies that have not been well explored. Most, but not all, results suggest that recent changes in global climate inferred from surface air temperature are likely not due solely to natural causes. At present it is not possible to make a very confident statement about the relative contributions of specific natural and anthropogenic forcings to observed climate change. One of the main reasons is that fully realistic simulations of climate change due to the combined effects of all anthropogenic and natural forcings mechanisms have yet to be computed. A List of recommendations for reducing some of the uncertainties that currently hamper detection and attribution studies is presented. C1 Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, Dept 0224, La Jolla, CA 92093 USA. Max Planck Inst Meteorol, Hamburg, Germany. Natl Ctr Environm Predict, Washington, DC USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. Univ Washington, JISAO, Seattle, WA 98195 USA. Univ E Anglia, Norwich NR4 7TJ, Norfolk, England. Univ Maryland, College Pk, MD 20742 USA. Lamont Doherty Earth Observ, Int Res Inst, Palisades, NY 10964 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Meteorol Off, Hadley Ctr Climate Predict & Res, Bracknell RB12 2SZ, Berks, England. RP Barnett, TP (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, Dept 0224, La Jolla, CA 92093 USA. RI Jones, Philip/C-8718-2009; Santer, Benjamin/F-9781-2011; Tett, Simon/B-1504-2013; Delworth, Thomas/C-5191-2014 OI Jones, Philip/0000-0001-5032-5493; Tett, Simon/0000-0001-7526-560X; NR 68 TC 113 Z9 115 U1 1 U2 21 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 1999 VL 80 IS 12 BP 2631 EP 2659 DI 10.1175/1520-0477(1999)080<2631:DAAORC>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 261PA UT WOS:000084016500003 ER PT J AU Kalinowski, ST Hedrick, PW Miller, PS AF Kalinowski, ST Hedrick, PW Miller, PS TI No inbreeding depression observed in Mexican and red wolf captive breeding programs SO CONSERVATION BIOLOGY LA English DT Article ID CANIS-LUPUS POPULATION; PEROMYSCUS-POLIONOTUS; CONSERVATION; SELECTION AB Inbreeding depression is expected to affect populations of outbreeding mammals in inverse proportion to their population size and can affect whether small populations persist or go extinct. We used studbook records to examine the effect of inbreeding upon juvenile viability and litter size in two endangered species that have recently been reintroduced to the wild: the Mexican wolf (Canis lupus baileyi) and the red wolf (C. rufus). We found that neither juvenile viability nor litter size was lowered by inbreeding in either taxon. In fact, both captive breeding programs appear to have less lethal equivalents than the median estimate for mammals. We did find that year of birth was correlated with increasing viability in both taxa. We conclude that there is no evidence that inbreeding depression will prove a major obstacle to the success of either recovery effort. C1 NW Fisheries Sci Ctr, Div Biol Control, Seattle, WA 98112 USA. Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. Conservat Breeding Spacialist Grp, Apple Valley, MN 55124 USA. RP Kalinowski, ST (reprint author), NW Fisheries Sci Ctr, Div Biol Control, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM steven.kalinowski@noaa.gov RI Kalinowski, Steven/A-7607-2008 NR 26 TC 41 Z9 41 U1 3 U2 34 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD DEC PY 1999 VL 13 IS 6 BP 1371 EP 1377 DI 10.1046/j.1523-1739.1999.98346.x PG 7 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 260RF UT WOS:000083963100018 ER PT J AU Miller, MW Sluka, R AF Miller, MW Sluka, R TI Coral-seagrass interaction in an anthropogenically enriched lagoon SO CORAL REEFS LA English DT Article ID GROWTH C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Oceanogr Soc Maldives, POB 2075, Male, Maldives. RP Miller, MW (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 75 Virgina Beach Dr, Miami, FL 33149 USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD DEC PY 1999 VL 18 IS 4 BP 368 EP 368 DI 10.1007/s003380050214 PG 1 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 265ZA UT WOS:000084275100013 ER PT J AU Bunce, L Gustavson, K Williams, J Miller, M AF Bunce, L Gustavson, K Williams, J Miller, M TI The human side of reef management: a case study analysis of the socioeconomic framework of Montego Bay Marine Park SO CORAL REEFS LA English DT Article DE marine park; reef management; socioeconomic; Montego Bay; Jamaica ID RURAL APPRAISAL; CORAL-REEFS; JAMAICA AB This study furthers our understanding of the role of socioeconomics in coral reef management by demonstrating the importance, as well as means, of incorporating socioeconomic information into coral reef management. A case study analysis was made of the socioeconomic context of the three primary user groups in Montego Bay Marine Park, Jamaica: fishers, hoteliers and watersports operators. The primary means of data collection were document analysis, interviews with individuals representative of user groups, focus groups and participant observation. The results regarding user's awareness, user groups' relations with the managing agency, relations among and within user groups, resource use patterns, and sociocultural values demonstrate the need to: increase public awareness of the benefits of the Park, increase user awareness of Park management activities, increase user involvement in Park management, and develop intersectoral coordination. These findings provide useful guidance for future Park management and, in a more general context, illustrate the importance of socioeconomic assessments for reef management. C1 NOAA, Int Program Off NIPO, Natl Ocean Serv, Silver Spring, MD 20910 USA. Univ Victoria, Dept Geog, Victoria, BC V8W 3P5, Canada. Montego Bay Marine Pk, Montego Bay, Jamaica. RP Bunce, L (reprint author), NOAA, Int Program Off NIPO, Natl Ocean Serv, 1305 East West Highway,SSMC 4,13th Floor, Silver Spring, MD 20910 USA. NR 37 TC 18 Z9 19 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD DEC PY 1999 VL 18 IS 4 BP 369 EP 380 DI 10.1007/s003380050215 PG 12 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 265ZA UT WOS:000084275100014 ER PT J AU Klinedinst, DB Currie, LA AF Klinedinst, DB Currie, LA TI Direct quantification of PM2.5 fossil and biomass carbon within the Northern Front Range Air Quality Study's domain SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; FACILITY; OCEAN; C-14 AB Radiocarbon (C-14) analyses of PM2.5 (particulate matter with an aerodynamic diameter of 2.5 mu m or less) of both ambient and source samples from the Northern Front Range Air Quality Study (NFRAQS) in Colorado were performed. The C-14 analyses were undertaken to provide direct fossil vs modern (biomass) carbon source discrimination data for a subset of summer and winter 1996-1997 samples collected within the Denver metropolitan area. Samples were prepared for C-14 accelerator mass spectrometry measurements using techniques specially developed for small samples, i.e., <100 mu g C. For the days and sampling periods analyzed the median and interquartile range of the winter blank corrected fraction of modern carbon was 23% (16-34%) at Welby and 27% (25-37%) at Brighten. The summer samples exhibited a more mixed signature with a median and interquartile range of 47% (9-70%). Source samples yielded C-14 signatures consistent with expectation. We conclude fossil-derived sources contribute substantially in both seasons and at both locations; however, the biomass carbon component dominates episodically in the summer. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Klinedinst, DB (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 31 TC 70 Z9 72 U1 2 U2 11 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 DEC 1 PY 1999 VL 33 IS 23 BP 4146 EP 4154 DI 10.1021/es990355m PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 261TB UT WOS:000084024200020 ER PT J AU DeLorenzo, ME Scott, GI Ross, PE AF DeLorenzo, ME Scott, GI Ross, PE TI Effects of the agricultural pesticides atrazine, deethylatrazine, endosulfan, and chlorpyrifos on an estuarine microbial food web SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE estuarine; microbial food web; deethylatrazine; endosulfan; chlorpyrifos ID PHYTOPLANKTON; WATERS; ECOSYSTEMS; PRODUCTS; BACTERIA; RIVER; SEA AB Agricultural pesticide runoff is a critical issue for many southeastern estuaries. The estuarine microbial food web plays an important role in nutrient cycling and transfer of nutrients to higher trophic levels. The present study examined the effects of agricultural pesticides on the estuarine microbial food web. Polyurethane foam substrates were used to collect microbial communities from a reference tidal creek in the North Inlet National Estuarine Research Reserve (Georgetown, SC, USA). Colonized substrates were brought into the laboratory and exposed to the following commonly used agricultural pesticides: atrazine (and a metabolite, deethylatrazine), endosulfan, and chlorpyrifos. Chlorophyll a, phototrophic carbon assimilation, dissolved oxygen, and phototrophic biovolume were significantly reduced at concentrations of 50 and 250 mu g/L atrazine and deethylatrazine. Generally, inhibition of the phytoplankton resulted in increased bacterial abundance and productivity, whereas heterotrophic ciliate and flagellate abundances were not affected. Total bacterial abundance, but not heterotrophic bacterial productivity, was significantly reduced with endosulfan treatments of 1 and 10 mu g/L. Endosulfan was primarily found to target the cyanobacteria. Changes in biomass reflected compositional shifts in the phototrophs. The abundance of heterotrophic ciliates and flagellates was significantly reduced at 10 mu g/L chlorpyrifos. Bacterial abundance and productivity increased, whereas phototrophic variables decreased. Agricultural pesticides were found to alter both functional and structural aspects of the estuarine microbial food web. C1 Natl Ocean Serv, US Dept Commerce, Natl Oceanog & Atmospher Adm, Coastal Ctr Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Colorado Sch Mines, Environm Sci & Engn Div, Golden, CO 80401 USA. RP DeLorenzo, ME (reprint author), Natl Ocean Serv, US Dept Commerce, Natl Oceanog & Atmospher Adm, Coastal Ctr Environm Hlth & Biomol Res, 219 Ft Johnson Rd, Charleston, SC 29412 USA. EM mdelorenzo@noaa.gov NR 40 TC 40 Z9 42 U1 1 U2 19 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD DEC PY 1999 VL 18 IS 12 BP 2824 EP 2835 DI 10.1897/1551-5028(1999)018<2824:EOTAPA>2.3.CO;2 PG 12 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 258ZV UT WOS:000083870300024 ER PT J AU Rilling, GC Houde, ED AF Rilling, GC Houde, ED TI Regional and temporal variability in distribution and abundance of bay anchovy (Anchoa mitchilli) eggs, larvae, and adult biomass in the Chesapeake Bay SO ESTUARIES LA English DT Article ID CTENOPHORE MNEMIOPSIS-LEIDYI; FISH ABUNDANCE; BISCAYNE BAY; LIFE-HISTORY; ICHTHYOPLANKTON; PREDATION; GROWTH; SCYPHOMEDUSAE; MORTALITY; DYNAMICS AB Patterns and variability in reproductive output of pelagic fish are seldom determined at the ecosystem scale. We examined temporal and spatial variability in spawning by bay anchovy (Anchoa mitchilli), and in distribution and abundances of its pelagic early-life stages, throughout Chesapeake Bay. On two cruises in June and July 1993, ichthyoplankton and zooplankton were collected on 15 transects at 18.5-km (10 nautical mile) intervals over the 260-km length of the bay. Finer-scale sampling was carried out in a grid of stations between two transects on each cruise. Regional abundance patterns of bay anchovy eggs and larvae in the lower, mid, and upper Bay were compared with zooplankton abundances, environmental variables, and biovolumes of two gelatinous predators-the scyphomedusa Chrysaora quinquecirrha and the lobate ctenophore Mnemiopsis leidyi. Abundances of anchovy eggs, and, especially, larvae were higher in July than in June. Baywide daily egg production increased from 4.25 x 10(12) in June to 8.43 x 10(12) in July. Concentrations of zooplankton that are potential anchovy prey nearly doubled on a baywide basis between June and July, while biovolumes of the ctenophore declined. Except for scyphomedusan biovolumes, all analyzed organisms differed regionally in abundance and were patchily distributed at 1-km to 10-km sampling scales. Negative correlations between larval anchovy abundances and gelatinous predator biovolumes suggested that predation may have controlled abundances of bay anchovy early-life stages. Biomasses of adult anchovy, estimated from daily egg productions, were higher in the lower Bay and remarkably similar-23,433 tons in June and 23,194 tons in July. Most spawning by bay anchovy occurred during July in the seaward third of Chesapeake Bay, emphasizing the importance of this region for recruitment potential of the Bay's most abundant fish. C1 Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, Solomons, MD 20688 USA. RP Rilling, GC (reprint author), NOAA, Off Ocean & Coastal Resource Management, Coastal Programs Div, 1305 EW Highway,11th Floor, Silver Spring, MD 20910 USA. RI Houde, Edward/D-8498-2012 NR 53 TC 27 Z9 28 U1 1 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1999 VL 22 IS 4 BP 1096 EP 1109 DI 10.2307/1353087 PG 14 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 280LR UT WOS:000085104700024 ER PT J AU Sherman, K Duda, AM AF Sherman, K Duda, AM TI Large marine ecosystems: An emerging paradigm for fishery sustainability SO FISHERIES LA English DT Article ID ZOOPLANKTON; ATLANTIC AB Large marine ecosystems (LMEs) are areas of ocean space with distinct bathymetry, hydrography, productivity, and trophic relationships. On a global scale, researchers have described 50 LMEs; these areas account for 95% of the annual global marine fishery yields. Retrospective analyses of the principal forces driving changes in the yields and sustainability of fisheries biomass have been completed for 33 of the LMEs. Based on the results of these studies, working groups within the National Oceanic and Atmospheric Administration and National Marine Fisheries Service have developed a five-module strategic approach for strengthening the links between science-based assessments of changing LME states and socioeconomic benefits of long-term sustainability of fisheries. The modules provide a framework for developing countries to improve assessment and management of LME fisheries, habitat and related pollution reduction needs. The LME projects currently funded or being developed in collaboration with the Global Environment Facility, World Bank, and other international donor agencies represent a broad global spectrum of stakeholders. Included are the ministries of Fisheries, Environment, Finance, and other public and private sector interests of 14 countries in Asia, 20 countries in Africa, 16 countries in Central and South America, and 9 countries in eastern Europe. C1 NE Fisheries Sci Ctr, Narraganett Lab, Off Marine Ecosyst Studies, Narragansett, RI 02882 USA. RP Sherman, K (reprint author), NE Fisheries Sci Ctr, Narraganett Lab, Off Marine Ecosyst Studies, 28 Tarzwell Dr, Narragansett, RI 02882 USA. NR 72 TC 33 Z9 38 U1 0 U2 4 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0363-2415 J9 FISHERIES JI Fisheries PD DEC PY 1999 VL 24 IS 12 BP 15 EP 26 DI 10.1577/1548-8446(1999)024<0015:LME>2.0.CO;2 PG 12 WC Fisheries SC Fisheries GA 325WE UT WOS:000087698800003 ER PT J AU Bailey, KM Bond, NA Stabeno, PJ AF Bailey, KM Bond, NA Stabeno, PJ TI Anomalous transport of walleye pollock larvae linked to ocean and atmospheric patterns in May 1996 SO FISHERIES OCEANOGRAPHY LA English DT Article DE Alaska coastal current; Alaska; currents; larval transport; recruitment; Shelikof Strait; Theragra chalcogramma; walleye pollock; wind ID GULF-OF-ALASKA; THERAGRA-CHALCOGRAMMA; SHELIKOF-STRAIT; RECRUITMENT; SURVIVAL; MORTALITY; MODEL; FISH; EGGS AB Larvae from a large aggregation of walleye pollock spawning in early spring in Shelikof Strait, Gulf of Alaska, are normally transported to the south-west in the vigorous Alaska Coastal Current. In the spring of 1996, anomalous winds resulted in unusually weak transport in the Shelikof Strait sea valley. The main aggregation of larval pollock in the Shelikof region was surveyed four times in 1996 over a period of about 40 days, including finer-scale sampling of the leading south-western edge of the larval distribution. The south-western edge of the larval distribution showed weak transport up the sea valley for a period of about 10 days, corresponding to the observations of currents, after which many larvae were transported over the shelf region to the west. These observations are unique in over 15 years of monitoring larval transport patterns and demonstrate how anomalous weather, and hence current patterns, influence variability in larval transport. C1 NOAA, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Bailey, KM (reprint author), NOAA, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 22 TC 8 Z9 9 U1 0 U2 2 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 1999 VL 8 IS 4 BP 264 EP 273 DI 10.1046/j.1365-2419.1999.00113.x PG 10 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 273AW UT WOS:000084684500003 ER PT J AU Brodeur, RD Mills, CE Overland, JE Walters, GE Schumacher, JD AF Brodeur, RD Mills, CE Overland, JE Walters, GE Schumacher, JD TI Evidence for a substantial increase in gelatinous zooplankton in the Bering Sea, with possible links to climate change SO FISHERIES OCEANOGRAPHY LA English DT Article DE Bering Sea; ecosystem change; physical-biological coupling; scyphomedusae ID SCYPHOMEDUSAN CHRYSAORA-QUINQUECIRRHA; PELAGIC CNIDARIANS; CHESAPEAKE BAY; ICE-EDGE; PREDATION; CTENOPHORES; POPULATIONS; ECOSYSTEMS; TEMPERATURE; PACIFIC AB We examined quantitative catches of large medusae from summer bottom trawl surveys that sampled virtually the same grid station on the eastern Bering Sea shelf using the same methodology every year from 1979 to 1997. This series shows a gradual increase in biomass of medusae from 1979 to 1989, followed by a dramatic increase in the 1990s. The median biomass increased tenfold between the 1982-1989 and 1990-1991 periods. Most of this biomass was found within the Middle Shelf Domain (50 < z < 100 m). The greatest rate of increase occurred in the north-west portion of this domain. Whether this dramatic increase in biomass of gelatinous zooplankton has resulted from some anthropogenic perturbation of the Bering Sea environment or is a manifestation of natural ecosystem variability is unclear. However, several large-scale winter/spring atmospheric and oceanographic variables in the Bering Sea exhibited concomitant changes beginning around 1990, indicating that a possible regime change occurred at this time. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Washington, Friday Harbor Labs, Friday Harbor, WA 98250 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Two Crow Environm Consultants, Silver City, NM 88062 USA. RP Brodeur, RD (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2030 Marine Sci Dr, Newport, OR 97365 USA. NR 68 TC 158 Z9 172 U1 3 U2 39 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 1999 VL 8 IS 4 BP 296 EP 306 DI 10.1046/j.1365-2419.1999.00115.x PG 11 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 273AW UT WOS:000084684500006 ER PT J AU Marlow, MS Stevenson, AJ Chezar, H McConnaughey, RA AF Marlow, MS Stevenson, AJ Chezar, H McConnaughey, RA TI Tidally generated sea-floor lineations in Bristol Bay, Alaska, USA SO GEO-MARINE LETTERS LA English DT Article ID SHELF AB Highly reflective linear features occur in water depths of 20-30 m in northern Bristol Bay (Alaska, USA) and are, in places, over 600 m in length. Their length-to-width ratio is over 100.1. The lineations are usually characterized by large transverse ripples with wavelengths of 1-2 m. The lineations trend about N60 degrees E, and are spaced between 20 and 350 m. Main tidal directions near the lineations are N60 degrees E (flood) and S45 degrees W (ebb), which are parallel to subparallel to the lineations. They suggest that the lineations may be tidally generated. The lineations may be bright sonar reflections from a winnowed lag concentrate of coarse sand. C1 US Geol Survey, Menlo Park, CA 94025 USA. NOAA, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP Marlow, MS (reprint author), US Geol Survey, 345 Middlefield Rd, Menlo Park, CA 94025 USA. NR 17 TC 9 Z9 9 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0276-0460 J9 GEO-MAR LETT JI Geo-Mar. Lett. PD DEC PY 1999 VL 19 IS 4 BP 219 EP 226 DI 10.1007/s003670050112 PG 8 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA 273VT UT WOS:000084729100001 ER PT J AU Embley, RW Chadwick, WW Clague, D Stakes, D AF Embley, RW Chadwick, WW Clague, D Stakes, D TI 1998 Eruption of Axial Volcano: Multibeam anomalies and sea-floor observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DE-FUCA RIDGE; CRUSTAL ACCRETION; MIDOCEAN RIDGES; EVENT AB Lava flows erupted during the January/February 1998 seismic swarm at Axial Volcano on the Juan de Fuca Ridge have been identified by differencing of pre- and post-event multibeam bathymetric surveys and by seafloor observations. A sheet flow mote than 3 km in length and 500-800 m wide erupted from the uppermost south rift is the site of a robust hydrothermal system. 1998 lavas occur over about 9 km of the upper south rift zone, or about 20% of the along-axis length of the seismicity event (similar to 50 km). The estimated volume of lava erupted is 18-76 x 10(6) m(3) for the extrusion and 100-150 x 10(6) m(3) for the intrusion. The total volume is consistent with the volume from modeling of seafloor strain measurements recorded during the event. C1 Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR USA. Oregon State Univ, Cooperat Inst Marine Resources Studies, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA USA. RP Embley, RW (reprint author), Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 13 TC 77 Z9 77 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 DEC 1 PY 1999 VL 26 IS 23 BP 3425 EP 3428 DI 10.1029/1999GL002328 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800001 ER PT J AU Dziak, RP Fox, CG AF Dziak, RP Fox, CG TI The January 1998 earthquake swarm at axial volcano, Juan de Fuca Ridge: Hydroacoustic evidence of seafloor volcanic activity. SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EVENT AB On January 25, 1998 at 11:33Z, an intense swarm of earthquakes began within the summit caldera of Axial Volcano, central Juan de Fuca Ridge (JdFR). The earthquake swarm was detected using the U.S. Navy hydrophones in the northeast Pacific Ocean. The earthquake swarm lasted 11 days and produced 8247 detected (1037 located) earthquakes. During the first two days of the swarm, earthquake activity migrated from the summit caldera similar to 50 km along the south rift zone of Axial Volcano at rates of 0.92 +/- 0.13 and 0.23 +/- 0.09 m s(-1). Earthquake epicenter migration is characteristic of a lateral magma dike injection. The largest three swarm earthquakes occurred within the caldera. Their timing and mechanisms are consistent with adjustment of the caldera floor las magma is removed from beneath the summit. Earthquakes with short T-wave rise times (shallow focal depths) cluster at two spots along the summit and south rift zone, and are considered possible seafloor eruption sites. In situ ground deformation and hydrothermal plume monitors, and later shipboard observations, confirmed the occurrence of a seafloor volcanic eruption at the volcano's summit. C1 Oregon State Univ, NOAA, Hatfield Marine Sci Ctr, Newport, OR 97265 USA. Hatfield Marine Sci Ctr, Pacific Marine Environm Lab, NOAA, Newport, OR USA. RP Dziak, RP (reprint author), Oregon State Univ, NOAA, Hatfield Marine Sci Ctr, Newport, OR 97265 USA. NR 15 TC 77 Z9 77 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 DEC 1 PY 1999 VL 26 IS 23 BP 3429 EP 3432 DI 10.1029/1999GL002332 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800002 ER PT J AU Fox, CG AF Fox, CG TI In situ ground deformation measurements from the summit of axial volcano during the 1998 volcanic episode SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DE-FUCA RIDGE; MIDOCEAN RIDGE; SEAMOUNT AB Since September 1987, seafloor instrumentation monitoring ground deformation has been maintained on the summit of Axial Volcano on the central Juan de Fuca Ridge. During a January 1998 volcanic episode, pressure records from the central caldera showed a significant increase in pressure, indicating caldera subsidence of over 3 m. This observed subsidence is interpreted to represent volcanic deflation as magma is erupted and/or injected into the volcanic flanks. Temperature anomalies of nearly 0.45 degrees C were also observed. A comparison of the subsidence record with hydroacoustic recordings indicates a continuous volcanic tremor signal coincident with the subsidence event. The time-coincidence of subsidence of the summit caldera with migration of epicenters into the volcanic rift zones confirms that during the 1998 episode, the volcanic flanks were supplied by lateral dike injection from a central magma body, rather than locally derived magma sources. C1 Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA. RP Fox, CG (reprint author), Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, 2115 SE OSU Dr, Newport, OR 97365 USA. NR 11 TC 35 Z9 35 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 1999 VL 26 IS 23 BP 3437 EP 3440 DI 10.1029/1999GL900491 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800004 ER PT J AU Chadwick, WW Embley, RW Milburn, HB Meinig, C Stapp, M AF Chadwick, WW Embley, RW Milburn, HB Meinig, C Stapp, M TI Evidence for deformation associated with the 1998 eruption of Axial Volcano, Juan de Fuca Ridge, from acoustic extensometer measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Acoustic extensometer instruments capable of making precise daily measurements of horizontal distance were deployed across the north rift zone of Axial Volcano in June 1996 and were in place when a submarine eruption began on Axial's south rift zone in January 1998. The instruments recorded a gradual 9-cm extension over a 405-m baseline leading up to the eruption, and then an abrupt, 4-cm contraction at the time of the eruption. An elastic point-source deformation model shows that deflation of Axial's summit can explain both the 4-cm distance decrease at the extensometer: array and a 3.2-m subsidence measured by another instrument in the caldera, if the pressure source is located at a depth of 3.8 km below the center of the caldera. The 9-cm distance increase may represent pre-eruption spreading across the rift zone. C1 Oregon State Univ, Hatfield Marine Sci Ctr, NOAA, Newport, OR 97365 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Chadwick, WW (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, NOAA, 2115 SE OSU Dr, Newport, OR 97365 USA. NR 5 TC 35 Z9 35 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 DEC 1 PY 1999 VL 26 IS 23 BP 3441 EP 3444 DI 10.1029/1999GL900498 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800005 ER PT J AU Baker, ET Fox, CG Cowen, JP AF Baker, ET Fox, CG Cowen, JP TI In situ observations of the onset of hydrothermal discharge during the 1998 submarine eruption of Axial Volcano, Juan de Fuca Ridge SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GROUND DEFORMATION; MIDOCEAN RIDGE; VENT FIELD; HEAT-FLUX; SEAMOUNT; DIFFUSE; SUMMIT; EVENT; APRIL; RISE AB A volcanic eruption at the summit of Axial Volcano on January 25, 1998, instantaneously created extensive and vigorous hydrothermal discharge. Moorings 2 km apart along the eruption fissure recorded temperature increases of similar to 0.6 degrees C up to 115 m above bottom within hours of initial seismic activity. Water temperatures at the mooring sites remained high for about 5 days, then declined steadily over the next 2 weeks. A response cruise 18 days after the eruption found hydrothermal temperature anomalies of similar to 0.1 degrees C over the eruption site, and a more intense and much thicker plume 20 km downstream of the eruption. We estimate the steady-state heat flux required to produce this distal plume, evidence of discharge conditions perhaps 1-13 days after the eruption, as 60-230 GW. The Axial eruption thus produced the largest vent field heat flux yet measured, but these high levels lasted less than 3 weeks. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA. Univ Hawaii, Dept Oceanog, SOEST, Honolulu, HI 96822 USA. RP Baker, ET (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 17 TC 34 Z9 34 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1999 VL 26 IS 23 BP 3445 EP 3448 DI 10.1029/1999GL002331 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800006 ER PT J AU Lupton, J Baker, E Embley, R Greene, R Evans, L AF Lupton, J Baker, E Embley, R Greene, R Evans, L TI Anomalous helium and heat signatures associated with the 1998 Axial Volcano Event, Juan de Fuca Ridge SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID COAXIAL EVENT; EVOLUTION; RATIOS; PLUMES AB Water-column plumes sampled before and after the 1998 eruptive event on Axial Volcano, Juan de Fuca Ridge, showed a complex pattern in He-3 and heat very different from that observed during previous magma injection events. Plumes detected in 1997 before the event had relatively high He-3/heat consistent with the volatile-rich character of the known hydrothermal vents within the summit caldera. A response cruise in February 1998 immediately after the event failed to detect any event plumes, but instead found an intense steady-state type plume with high-temperature signals, moderate 3He enrichments, and low He-3/heat ratios. This plume was present over the caldera and extended a considerable distance off axis. In contrast, all of the plumes detected during follow-up cruises in July-September 1998 had moderate temperature signals, high He-3 concentrations, and elevated He-3/heat ratios. Comparison with previous events suggests that the low He-3/heat plume sampled in February was either the remnant of an event plume which had already migrated off axis, or an event plume-like discharge which was smeared out by strong currents. It is likely that the high He-3/heat plumes observed in July-September were derived from the injected dike or from the new lava flow. C1 Hatfield Marine Sci Ctr, Pacific Marine Environm Lab, NOAA, Newport, OR 97365 USA. Pacific Marine Environm Lab, NOAA, Seattle, WA 98195 USA. Oregon State Univ, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resource Studies, Newport, OR 97365 USA. RP Lupton, J (reprint author), Hatfield Marine Sci Ctr, Pacific Marine Environm Lab, NOAA, Newport, OR 97365 USA. NR 15 TC 7 Z9 7 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1999 VL 26 IS 23 BP 3449 EP 3452 DI 10.1029/1999GL002330 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800007 ER PT J AU McLaughlin-West, EA Olson, EJ Lilley, MD Resing, JA Lupton, JE Baker, ET Cowen, JP AF McLaughlin-West, EA Olson, EJ Lilley, MD Resing, JA Lupton, JE Baker, ET Cowen, JP TI Variations in hydrothermal methane and hydrogen concentrations following the 1998 eruption at Axial Volcano SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DE-FUCA RIDGE; SYSTEMS; FLUIDS AB During the February response cruise to Axial Volcano, methane and hydrogen concentrations within the plume were significantly elevated above background. CH4/He-3 ratios were found to be 5-10 times greater than previously reported values for unsedimented ridges. An average delta(13)C value of -32.7 +/- 0.8 parts per thousand was determined for CH4 concentrations > 10 nM and CH4/Mn ratios were determined to be 2.2. Hydrogen concentrations as high as 183 nM were measured; however most were < 10 nM. Microbial oxidation of methane was negligible (< 0.001 day(-1)) during this sampling period. However, microbial hydrogen oxidation was sufficient to explain decreased H-2 concentrations measured at 'older' downstream stations. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. Hatfield Marine Sci Ctr, Pacific Marine Environm Lab, NOAA, Newport, OR 97365 USA. Rice Univ, Dept Environm Sci & Engn, Houston, TX 77005 USA. RP McLaughlin-West, EA (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 18 TC 15 Z9 15 U1 0 U2 9 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 1999 VL 26 IS 23 BP 3453 EP 3456 DI 10.1029/1999GL002336 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800008 ER PT J AU Cronin, MF McPhaden, MJ AF Cronin, MF McPhaden, MJ TI Diurnal cycle of rainfall and surface salinity in the western Pacific warm pool SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The diurnal cycles of rainfall and surface salinity in the western equatorial Pacific were computed for the period August 1991-December 1994 using hourly data from the Tropical Atmosphere Ocean (TAO) mooring array enhanced for the Coupled Ocean Atmosphere Response Experiment (COARE). The analysis shows preferential rainfall during predawn hours. Nighttime mixing typically caused the predawn rainfall to mix downward into higher salinity subsurface waters. In contrast, afternoon rainfall, although weaker, generally produced a stable shallow layer of very low salinity. Consequently, sea surface salinity (SSS) exhibited a weak diurnal cycle, with anomalously low salinity in the late afternoon and anomalously high salinity at night. At 1 m depth, the SSS diurnal cycle anomalies were similar to 0.005 psu. Although nearly two orders of magnitude less than the SSS standard deviation for this region, the anomalies were significant at the 95% confidence level. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Cronin, MF (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI McPhaden, Michael/D-9799-2016 NR 13 TC 20 Z9 20 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 DEC 1 PY 1999 VL 26 IS 23 BP 3465 EP 3468 DI 10.1029/1999GL010504 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800011 ER PT J AU Demirkol, MK Inan, US Bell, TF Kanekal, SG Wilkinson, DC AF Demirkol, MK Inan, US Bell, TF Kanekal, SG Wilkinson, DC TI Ionospheric effects of relativistic electron enhancement events SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VLF SIGNALS; WAVE-GUIDE; PRECIPITATION; SOLAR AB The relativistic electron population as measured both at geosynchronous orbit and at low altitudes at subauroral latitudes exhibits pronounced fluctuations in association with magnetospheric substorm and solar activity. A ground-satellite correlative study based on amplitude and phase measurements of VLF signals propagating in the earth-ionosphere waveguide indicates that the relativistic electron enhancements are accompanied bq similar enhancements in nighttime ionospheric conductivity produced by associated enhanced precipitation. VLF signal amplitudes are found to exhibit >10 dB changes, showing the same 27 day cycle and 2-3 day rise and fall time pattern as relativistic electron enhancement events recorded by GOES 7 and SAMPEX, and indicating that the nighttime lower ionospheric electron density at subauroral latitudes is detectably affected by 27-day periodicity in solar rotation. C1 Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Geophys Data Ctr, Boulder, CO 80303 USA. RP Demirkol, MK (reprint author), Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. NR 15 TC 13 Z9 13 U1 0 U2 8 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 1999 VL 26 IS 23 BP 3557 EP 3560 DI 10.1029/1999GL010686 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800034 ER PT J AU Broecker, W Lynch-Stieglitz, J Archer, D Hofmann, M Maier-Reimer, E Marchal, O Stocker, T Gruber, N AF Broecker, W Lynch-Stieglitz, J Archer, D Hofmann, M Maier-Reimer, E Marchal, O Stocker, T Gruber, N TI How strong is the Harvardton-Bear constraint? SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID AVERAGED OCEAN MODEL; ATMOSPHERIC CO2; THERMOHALINE CIRCULATION; LATITUDE; ATLANTIC AB We compare the sensitivity of the partial pressure of CO2 in the warm surface ocean and atmosphere to the influence of the ocean's cold water outcrops in a wide spectrum of models. While in simple box models the cold ocean dominates, in three-dimensional ocean general circulation models, this influence is considerably smaller, suggesting that exchange processes between the warm and cold regime in the real ocean are extremely important in determining the distribution of chemical properties. C1 Columbia Univ, Lamont Doherty Earth Observ, Dept Earth & Environm Sci, Palisades, NY 10964 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Konstanz, Fak Biol, D-78464 Constance, Germany. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Broecker, W (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Dept Earth & Environm Sci, Rt 9W, Palisades, NY 10964 USA. RI Gruber, Nicolas/B-7013-2009; Archer, David/K-7371-2012; Stocker, Thomas/B-1273-2013; OI Gruber, Nicolas/0000-0002-2085-2310; Archer, David/0000-0002-4523-7912; Lynch-Stieglitz, Jean/0000-0002-9353-1972 NR 19 TC 47 Z9 47 U1 4 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1999 VL 13 IS 4 BP 817 EP 820 DI 10.1029/1999GB900050 PG 4 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 270VK UT WOS:000084557700001 ER PT J AU Conway, TJ Tans, PP AF Conway, TJ Tans, PP TI Development of the CO2 latitude gradient in recent decades SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC CO2 AB Because 90% of the CO2 from fossil fuel combustion is emitted in the Northern Hemisphere, annual mean atmospheric CO2 mixing ratios are higher at middle and high northern latitudes than in the Southern Hemisphere. The observed CO2 latitude gradient varies interannually and has generally increased as fossil fuel CO2 emissions have increased. Back extrapolation of the measured CO2 latitude gradient to zero fossil fuel emissions gives a latitude gradient with the Northern Hemisphere lower than the Southern. A linear regression of Mauna Loa minus South Pole annual mean differences versus fossil fuel emissions for 1958 through 1996 gives a slope of 0.5 mu mol mol(-1) (abbreviated as ppm CO2) (Gt C)(-1) (sigma = 0.03) and an intercept (at zero fossil fuel emissions) of -0.8 ppm (sigma = 0.2). Shorter data records yield similar results with larger uncertainties. We argue that this extrapolated gradient does not represent preindustrial conditions but is more correctly viewed as a decadal average gradient due to natural sources and sinks that underlie the anthropogenic perturbation. We interpret the extrapolated gradient as evidence for a contemporary Northern Hemisphere sink that has been proposed on the basis of other measurement and model approaches. The slopes (ppm CO2 per gigaton of C from fossil fuel burning) calculated from sufficiently long records tend to agree with model calculations based on fossil fuel emissions, suggesting that any trend in the Northern Hemisphere sink, during the period of the measurements, has been small relative to the trend in fossil fuel emissions. C1 NOAA, ERL, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Conway, TJ (reprint author), NOAA, ERL, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80303 USA. NR 17 TC 15 Z9 15 U1 0 U2 4 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 1999 VL 13 IS 4 BP 821 EP 826 DI 10.1029/1999GB900045 PG 6 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 270VK UT WOS:000084557700002 ER PT J AU Sonnerup, RE Quay, PD McNichol, AP Bullister, JL Westby, TA Anderson, HL AF Sonnerup, RE Quay, PD McNichol, AP Bullister, JL Westby, TA Anderson, HL TI Reconstructing the oceanic C-13 Suess effect SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID LABRADOR SEA-WATER; FOSSIL-FUEL CO2; ANTHROPOGENIC CO2; SURFACE OCEANS; NORTH-ATLANTIC; PACIFIC-OCEAN; CARBON; RADIOCARBON; DELTA-C-13; INCREASE AB The anthropogenic delta(13)C change for the time period 1968 to 1991 was determined based on calculations of the preformed C-13/C-12 of dissolved inorganic carbon (DIC) distributions on isopycnal surfaces in the main thermocline of the Pacific, North Atlantic and South Indian Oceans. The time rate of change of preformed delta(13)C (the C-13 Suess effect) along isopycnals was calculated using CFC-derived water ages and yields a time history of the surface water delta(13)C change at the isopycnal outcrop location. The surface ocean Suess effect recorded on isopycnals decreased with increasing outcrop latitude from approximately -0.2 parts per thousand decade(-1) within the subtropics to around -0.1 parts per thousand decade(-1) in the subpolar oceans. In the Pacific Ocean these surface delta(13)C change rate reconstructions agree, both in magnitude and meridional trend, with direct observations of surface ocean delta(13)C changes reported from time series measurements and from comparisons of surface water delta(13)C of DIC measurements in 1970 and 1993, A global ocean average surface delta(13)C rate of change of -0.15 +/- 0.04 parts per thousand decade(-1) is determined, which is slightly smaller than a previous time series data and model-based estimate (-0.171 parts per thousand decade(-1), [Bacastow et al., 1996]). Depth integrations of the C-13 reconstructions in the Pacific, Indian, and Atlantic Oceans, when combined with these previous individual depth profile comparisons and Geochemical Ocean Sections Study bomb C-14 inventories [Quay et al., 1992], imply a global depth-integrated delta(13)C change rate of -9.7 +/- 2.4 parts per thousand m yr(-1) over the time period 1970-1990. These results imply a net oceanic CO2 uptake rate of 1.9 +/- 0.9 Gt C yr(-1) over the time period 1970-1990 when applied to an atmospheric (CO2)-C-13 and (CO2)-C-12 budget. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. Woods Hole Oceanog Inst, Natl Ocean Sci Accelerator Mass Spectrometry Faci, Woods Hole, MA 02543 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Sonnerup, RE (reprint author), Univ Copenhagen, Niels Bohr Inst Astron Phys & Geophys, Danish Ctr Earth Syst Sci, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark. EM rolf@apollo.dcess.ku.dk; pdquay@u.washington.edu; amcnichol@whoi.edu; johnb@pmel.noaa.gov NR 61 TC 53 Z9 53 U1 2 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1999 VL 13 IS 4 BP 857 EP 872 DI 10.1029/1999GB900027 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 270VK UT WOS:000084557700005 ER PT J AU Bowling, DR Baldocchi, DD Monson, RK AF Bowling, DR Baldocchi, DD Monson, RK TI Dynamics of isotopic exchange of carbon dioxide in a Tennessee deciduous forest SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID RELAXED EDDY ACCUMULATION; AMAZONIAN TROPICAL FORESTS; WATER-VAPOR EXCHANGE; BOREAL FOREST; BOUNDARY-LAYER; CO2 CONCENTRATION; FLUX MEASUREMENTS; TEMPERATE FOREST; ATMOSPHERIC CO2; STABLE OXYGEN AB The combination of isotopic measurements and micrometeorological flux measurements is a powerful new approach that will likely lead to new insight into the dynamics of CO2 exchange between terrestrial ecosystems and the atmosphere. Since the biological processes of photosynthesis and respiration modify the stable isotopic signature of atmospheric CO2 in different ways, measurements of the net fluxes of CO2, (CO2)-C-13, and (COO)-O-18 can be used to investigate the relative contribution of each process to net ecosystem CO2 exchange. We used two independent approaches to measure isotopic fluxes of CO2 over a Tennessee oak-maple-hickory forest in summer 1998. These approaches involved (1) a combination of standard eddy covariance with intensive flask sampling, and (2) a modification to the relaxed eddy accumulation technique. Strong isotopic signals associated with photosynthesis and respiration were observed and persisted in forest air despite the potential for mixing due to atmospheric turbulence. Calm nights allowed a buildup of respiratory CO2 below the canopy and were associated with isotopically depleted forest air in the morning. Windy nights were followed by a relatively more enriched early-morning isotopic signal. Entrainment of air from above the decaying nocturnal boundary layer during daytime mixed layer growth exerted strong control on isotopic composition of forest air, resulting in similar isotope ratios in the late afternoon despite different isotopic starting points following calm or windy nights. The influences of the convective boundary layer and turbulent mixing within the forest cannot be ignored when using isotopes of CO2 to investigate biological processes. C1 Univ Colorado, Dept Environm Populat & Organism Biol, Boulder, CO 80309 USA. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN USA. RP Bowling, DR (reprint author), Univ Utah, Dept Biol, 257 South 1400 East, Salt Lake City, UT 84112 USA. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 66 TC 58 Z9 62 U1 0 U2 6 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 1999 VL 13 IS 4 BP 903 EP 922 DI 10.1029/1999GB900072 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 270VK UT WOS:000084557700008 ER PT J AU Wilson, KB Carlson, TN Bunce, JA AF Wilson, KB Carlson, TN Bunce, JA TI Feedback significantly influences the simulated effect of CO2 on seasonal evapotranspiration from two agricultural species SO GLOBAL CHANGE BIOLOGY LA English DT Article DE carbon dioxide; evapotranspiration; maize; simulation; soybeans; stomatal conductance ID GLOBAL CLIMATE MODEL; ATMOSPHERIC CO2; STOMATAL CONDUCTANCE; REGIONAL TRANSPIRATION; WATER-USE; CARBON; PLANT; RESISTANCE; RESPONSES; LEAF AB The direct effect of elevated carbon dioxide on evapotranspiration over a growing season was investigated by scaling up single-leaf gas exchange measurements on soybean and corn plants grown and measured at three carbon dioxide concentrations. Stomatal conductance decreased markedly with increasing carbon dioxide in these species under most conditions. Coupled soil-vegetation-atmosphere models were used to scale up these single-leaf level measurements to simulate evapotranspiration at the regional scale from planting to harvest. The coupled modelling system introduced feedbacks over the season that are not present at the measurement level, which decreased the effect of carbon dioxide on evapotranspiration. Four sets of simulations were performed to evaluate specifically the magnitude of four feedbacks; two resulting from scale, surface layer and mixed layer feedback, one resulting from soil evaporation and one resulting from the interactions of stomatal conductance and the simulated canopy microclimate (physiological feedback). The feedbacks occurring from scale were consistent with previous analytical work indicating that transpiration becomes less dependent on stomatal conductance at larger scales. Evaporation from the soil has been generally neglected in past studies on carbon dioxide effects, but was especially important in decreasing the effects of carbon dioxide on evapotranspiration and showed a seasonal dynamic. The feedback resulting from physiological responses has also received less attention than the feedbacks from scale, but was only moderately important in these simulations. We also investigated the seasonal dynamics of how the observed increase in leaf area at elevated carbon dioxide affects evapotranspiration. Considering all the feedbacks and the observed increase in leaf area at elevated carbon dioxide, the simulated decrease in evapotranspiration was not negligible but was much less than the decrease in stomatal conductance. At the regional scale and maximum complexity in our model, the simulated decrease in seasonal evapotranspiration at doubled carbon dioxide (700 mu mol mol(-1)) was 5.4% for soybeans and 8.6% for corn. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. ARS, Climate Stress Lab, USDA, Beltsville Agr Res Ctr, Beltsville, MD 20705 USA. RP Wilson, KB (reprint author), NOAA, Atmospher Turbulence & Diffus Div, POB 2456, Oak Ridge, TN 37828 USA. NR 28 TC 38 Z9 42 U1 3 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 1999 VL 5 IS 8 BP 903 EP 917 DI 10.1046/j.1365-2486.1999.00280.x PG 15 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 279NN UT WOS:000085051700007 ER PT J AU Restrepo, VR Powers, JE AF Restrepo, VR Powers, JE TI Precautionary control rules in US fisheries management: specification and performance SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES Symposium on Confronting Uncertainty in the Evaluation and Implementation of Fisheries-Management Systems CY NOV 16-19, 1998 CL UNIV CAPE TOWN, GRAD SCH BUSINESS, CAPE TOWN, SOUTH AFRICA SP Int Council Explorat Sea, European Comm, Fdn Res Dev SA, Irvin & Johnson Ltd SA, Int Ctr Living Aquat Resources, Int Fishmeal & Oil Manufactures Assoc, Marine & Coastal Management, S African Network Coastal & Ocean Res, Suidor Fishing Pty Ltd SA, UN Food & Agr Org, Univ Cape Town HO UNIV CAPE TOWN, GRAD SCH BUSINESS DE fisheries management; harvest control rules; limits; precautionary approach; targets ID BIOLOGICAL REFERENCE POINTS AB Recent legislation in the United States has established fisheries-management criteria that have been interpreted as being consistent with international agreements and criteria for precautionary approaches. Proposed guidelines for implementing the legislation have been translated into scientific and technical guidance for developing limit and target control rules, with some suggestions for defaults. The control rules specify management actions (fishing mortality rate), based upon current stock status. The nature of these control rules is presented and discussed, giving the rationale for their specification and nature of the relationships, and some implementation problems are identified. (C) 1999 International Council for the Exploration of the Sea. C1 Int Commiss Conservat Atlantic Tunas, Madrid 28002, Spain. Natl Marine Fisheries Serv, Miami, FL 33149 USA. RP Restrepo, VR (reprint author), Int Commiss Conservat Atlantic Tunas, Corazon de Maria 8-6, Madrid 28002, Spain. NR 22 TC 58 Z9 60 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 1999 VL 56 IS 6 BP 846 EP 852 DI 10.1006/jmsc.1999.0546 PG 7 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 285MH UT WOS:000085392500006 ER PT J AU Darcy, GH Matlock, GC AF Darcy, GH Matlock, GC TI Application of the precautionary approach in the national standard guidelines for conservation and management of fisheries in the United States SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES Symposium on Confronting Uncertainty in the Evaluation and Implementation of Fisheries-Management Systems CY NOV 16-19, 1998 CL UNIV CAPE TOWN, GRAD SCH BUSINESS, CAPE TOWN, SOUTH AFRICA SP Int Council Explorat Sea, European Comm, Fdn Res Dev SA, Irvin & Johnson Ltd SA, Int Ctr Living Aquat Resources, Int Fishmeal & Oil Manufactures Assoc, Marine & Coastal Management, S African Network Coastal & Ocean Res, Suidor Fishing Pty Ltd SA, UN Food & Agr Org, Univ Cape Town HO UNIV CAPE TOWN, GRAD SCH BUSINESS DE control rules; Magnuson-Stevens Act; national standard guidelines; overfishing; precautionary approach; rebuilding; Sustainable Fisheries Act AB The passage of the Sustainable Fisheries Act (SFA) by the US Congress in 1996 fundamentally changed the approach to fisheries management in the United States. While an objective of the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act), the US Federal law controlling fisheries management in the Exclusive Economic Zone (EEZ), had always been to prevent overfishing, the attendant mechanisms for accomplishing the objective were not included in law. Some of the most significant amendments of the SFA were the addition of three new national standards, against which all proposed fishery conservation and management measures are measured, and the amendment of several other existing standards. Among the most important changes from the standpoint of conservation were changes that relate to national standard 1, regarding the prevention of overfishing and the rebuilding of overfished resources. Although the SFA did not use the term "precautionary approach" explicitly, the concept is implicitly expressed in several provisions of that Act. In developing the guidelines for implementation of the national standards, the National Marine Fisheries Service (NMFS) incorporated precautionary concepts to ensure that compliance with the SFA's measures to prevent and end overfishing are satisfied. In addition, the NMFS developed Further technical guidance to assist fishery scientists and managers in providing advice that appropriately considers risk, relative to the scientific information available, such that meaningful protection is afforded marine stocks and stock complexes. Such protection extends not only to consideration of stock recruitment, but also to maintenance of sustainable levels of stock biomass and biodiversity. (C) 1999 International Council for the Exploration of the Sea. C1 Natl Marine Fisheries Serv, Off Sustainable Fisheries, Silver Spring, MD 20910 USA. RP Darcy, GH (reprint author), Natl Marine Fisheries Serv, Off Sustainable Fisheries, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 10 TC 10 Z9 10 U1 1 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 1999 VL 56 IS 6 BP 853 EP 859 DI 10.1006/jmsc.1999.0533 PG 7 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 285MH UT WOS:000085392500007 ER PT J AU Fowler, CW AF Fowler, CW TI Management of multi-species fisheries: from overfishing to sustainability SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES Symposium on Confronting Uncertainty in the Evaluation and Implementation of Fisheries-Management Systems CY NOV 16-19, 1998 CL UNIV CAPE TOWN, GRAD SCH BUSINESS, CAPE TOWN, SOUTH AFRICA SP Int Council Explorat Sea, European Comm, Fdn Res Dev SA, Irvin & Johnson Ltd SA, Int Ctr Living Aquat Resources, Int Fishmeal & Oil Manufacturers Assoc, Marine & Coastal Management, S African Network Coastal & Ocean Res, Suidor Fishing Pty Ltd SA, UN Food & Agr Org, Univ Cape Town HO UNIV CAPE TOWN, GRAD SCH BUSINESS DE complexity; ecosystems; multi-species fisheries; risk; sustainability; systemic management ID ECOSYSTEMS; RESOURCES AB Any form of management adopted for species, ecosystems, or the biosphere must: (1) be consistent with management at other levels of biological organization; (2) account for reality, including the uncertainty of what we do not, or cannot, know, (3) result in living systems within their normal ranges of natural variation; (4) exercise precaution and consider risk in achieving sustainability; (5) be information-based and interdisciplinary: (6) include monitoring and assessment; (7) have clear goals and standards of reference; (8) be limited to controlling human activities; (9) include humans among the components of ecosystems and the biosphere. These nine objectives can be met simultaneously. The form of management that does so is described in this paper in its application to multi-species fisheries. It also applies in the management of fisheries harvesting from single populations, species, ecosystems or the biosphere. Such management would be based on empirically observed sustainability. In this paper, it is demonstrated how sustainable consumption from two groups of species in separate ecosystems is exemplified by the predators that feed on them. Such empirical examples are the result of a wide variety of factors, including the trial-and-error processes of evolution and various risks, including extinction, that impose limits. Implications for management are clear. Consumption rates by humans have been much too high and would have to be reduced significantly to match empirically proven sustainability at its maximum. Commercial takes of fish are far above the mean rates of consumption observed among predatory species in nature. It will be extremely difficult to implement the management that appears to be necessary. Nevertheless, consumption rates beyond the naturally observed limits have not been proven to sustainably avoid long-term risk. (C) 1999 International Council for the Exploration of the Sea. C1 Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Fowler, CW (reprint author), Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM charles.fowler@noaa.gov NR 24 TC 16 Z9 16 U1 1 U2 11 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 1999 VL 56 IS 6 BP 927 EP 932 DI 10.1006/jmsc.1999.0535 PG 6 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 285MH UT WOS:000085392500013 ER PT J AU DiNardo, GT Wetherall, JA AF DiNardo, GT Wetherall, JA TI Accounting for uncertainty in the development of harvest strategies for the Northwestern Hawaiian Islands lobster trap fishery SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES Symposium on Confronting Uncertainty in the Evaluation and Implementation of Fisheries-Management Systems CY NOV 16-19, 1998 CL UNIV CAPE TOWN, GRAD SCH BUSINESS, CAPE TOWN, SOUTH AFRICA SP Int Council Explorat Sea, European Comm, Fdn Res Dev SA, Irvin & Johnson Ltd SA, Int Ctr Living Aquat Resources, Int Fishmeal & Oil Manufactures Assoc, Marine & Coastal Management, S African Network Coastal & Ocean Res, Suidor Fishing Pty Ltd SA, UN Food & Agr Org, Univ Cape Town HO UNIV CAPE TOWN, GRAD SCH BUSINESS DE lobster trap fishery; risk-based harvest strategies; simulation model ID SPINY LOBSTER; RECRUITMENT AB The development of a new, risk-averse harvest policy for the Northwestern Hawaiian Islands lobster trap fishery, based on computer simulations, is described. The analysis results from a 1994 expert panel review recommendation to develop a new harvesting strategy that incorporated uncertainty in the stock assessment and variability in population processes, with the dual goals of achieving industry objectives (high average catch and catch stability) and low risk of recruitment overfishing. Monte Carlo projections of an age-based simulation model which allows for systematic, process, random and measurement error, as well as autocorrelation in recruitment innovations, were used to compare harvesting strategies and to assess their effects relative to the risk of overfishing over a range of discard mortality and retention scenarios. The expected effects of alternative strategies and consequences of uncertainty were presented to the Western Pacific Regional Fishery Management Council for evaluation, and a constant harvest rate strategy, subject to a 10% overfishing risk, was chosen. Because of the presumed high rate of discard mortality in the fishery, which has since been verified, the Council also chose a retain-all retention policy. The constant harvest rate associated with these objectives is 13%. (C) 1999 International Council for thr Exploration of the Sea. C1 Natl Marine Fisheries Serv, Honolulu Lab, SW Fisheries Sci Ctr, NOAA, Honolulu, HI 96822 USA. RP DiNardo, GT (reprint author), Natl Marine Fisheries Serv, Honolulu Lab, SW Fisheries Sci Ctr, NOAA, 2570 Dole St, Honolulu, HI 96822 USA. NR 10 TC 6 Z9 9 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 1999 VL 56 IS 6 BP 943 EP 951 DI 10.1006/jmsc.1999.0543 PG 9 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 285MH UT WOS:000085392500015 ER PT J AU Moore, ML Gazi, V Passino, KM Shackleford, WP Proctor, FM AF Moore, ML Gazi, V Passino, KM Shackleford, WP Proctor, FM TI Complex control system design and implementation - Using the NIST-RCS software library SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Article C1 Battelle Mem Inst, Columbus, OH 43201 USA. Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Control Syst Grp, Gaithersburg, MD 20899 USA. RP Moore, ML (reprint author), Battelle Mem Inst, 505 King Ave, Columbus, OH 43201 USA. RI Gazi, Veysel/M-6100-2013 OI Gazi, Veysel/0000-0002-4383-9215 NR 23 TC 4 Z9 4 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 0272-1708 J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD DEC PY 1999 VL 19 IS 6 BP 12 EP 28 DI 10.1109/37.806912 PG 17 WC Automation & Control Systems SC Automation & Control Systems GA 258ZL UT WOS:000083869500002 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 electrical calibration; electrical test structure; laser interferometry; length; line scale; measurement uncertainty; optical calibration; scale graduations; stage micrometer; potentiometer; 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. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Penzes, WB (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 5 TC 0 Z9 0 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 1999 VL 48 IS 6 BP 1178 EP 1182 DI 10.1109/19.816133 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 277GU UT WOS:000084925000028 ER PT J AU Randa, J Billinger, RL Rice, JL AF Randa, J Billinger, RL Rice, JL TI On-wafer measurements of noise temperature SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE noise; noise measurement; noise temperature; on-wafer noise; thermal noise ID PARAMETER MEASUREMENTS AB The NIST Noise Project has developed the theoretical formalism and experimental methods for performing accurate noise-temperature measurements on a wafer, This report summarizes the theoretical formulation and describes the design, methods, and results of tests performed to verify our ability to measure on-wafer noise temperature. Several different configurations with known off-wafer noise sources were used to obtain different, known, on-wafer noise temperatures. These were then measured, and the results were compared to predictions. Good agreement was found, with a worst-case disagreement of 2.6%, An uncertainty analysis of the measurements resulted in an estimated standard uncertainty (1 sigma) of 1.1% or less for most values of noise temperature. The tests also confirm our ability to produce known noise temperatures on a wafer, with an uncertainty of about 1%. C1 Natl Inst Stand & Technol, Radiofrequency Technol Div, Boulder, CO 80303 USA. RP Randa, J (reprint author), Natl Inst Stand & Technol, Radiofrequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 24 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 1999 VL 48 IS 6 BP 1259 EP 1269 DI 10.1109/19.816146 PG 11 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 277GU UT WOS:000084925000041 ER PT J AU Wang, CM Hale, PD Coakley, KJ AF Wang, CM Hale, PD Coakley, KJ TI Least-squares estimation of time-base distortion of sampling oscilloscopes SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE curve fitting; harmonic distortion; least-squares methods; mean-square error methods; timing jitter AB We present an efficient least-squares algorithm for estimating the time-base distortion of sampling oscilloscopes, The method requires measurements of signals at multiple phases and frequencies. The method can accurately estimate the order of the harmonic model that is used to account for the amplitude nonlinearity of the sampling channel. We study several practical problems related to the time-base distortion estimation, such as the effect of averaging and sample size requirements,! also compare the relative performance of various methods for estimating time-base distortion using simulated and measured data. C1 Natl Inst Stand & Technol, Stat Engn Div, Boulder, CO 80303 USA. Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Wang, CM (reprint author), Natl Inst Stand & Technol, Stat Engn Div, 325 Broadway, Boulder, CO 80303 USA. RI Hale, Paul/B-1737-2013 NR 14 TC 25 Z9 32 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 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 1999 VL 48 IS 6 BP 1324 EP 1332 DI 10.1109/19.816156 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 277GU UT WOS:000084925000051 ER PT J AU Randa, J Wiatr, W Billinger, RL AF Randa, J Wiatr, W Billinger, RL TI Comparison of adapter characterization methods SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT 1999 IEEE MTT-S International Microwave Symposium CY JUN 13-19, 1999 CL ANAHEIM, CALIFORNIA SP IEEE, Microwave Theory & Techniques Soc DE adapter characterization; microwave adapters; microwave measurements; microwave transitions AB We review and compare three different methods for characterization of precision adapters. Two of the methods are one-port techniques using two different reflective terminations in the one case and a matched load and multiple lines with reflective terminations in the other, The third technique is a conventional two-port adapter-removal technique. The intrinsic efficiencies of several different adapters are measured with each technique, and the results are compared. The results usually agree within about 0.005 for efficiencies near one. In all cases, the differences are consistent with the estimated uncertainties of the techniques, which range from about 0.002 to about 0.012, depending on the method, connectors, and frequency. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. Warsaw Univ Technol, Inst Elect Syst, Warsaw, Poland. RP Randa, J (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. RI Wiatr, Wojciech/G-4127-2013 NR 12 TC 11 Z9 12 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 1999 VL 47 IS 12 BP 2613 EP 2620 DI 10.1109/22.809014 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 264VZ UT WOS:000084204800059 ER PT J AU Narahari, Y Sudarsan, R Lyons, KW Duffey, MR Sriram, RD AF Narahari, Y Sudarsan, R Lyons, KW Duffey, MR Sriram, RD TI Design for tolerance of electro-mechanical assemblies: An integrated approach SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article DE assembly design process; assembly modeling; design tolerancing; statistical tolerancing; system level tolerancing; tolerance analysis; tolerance representation; tolerance synthesis ID MODELING SYSTEM; REPRESENTATION; PRODUCT; ENVIRONMENT; DIMENSIONS; FORM AB Tolerancing decisions can profoundly impact the quality and cost of electro-mechanical assemblies. Existing approaches to tolerance analysis and synthesis in design entail detailed knowledge of geometry of the assemblies and are mostly applicable during advanced stages of design, leading to a less than optimal design process. During the design process of assemblies, both the assembly structure and associated tolerance information evolve continuously, Therefore, significant gains can be achieved by effectively using this information to influence the design of the assembly. Motivated by this, we identify and explore two goals for future research that we believe can enhance the scope of tolerancing for the entire design process. The first goal is to advance tolerancing decisions to the earliest possible stages of design, This issue raises the need for effective representation of tolerancing information during different stages of design and for effective assembly modeling. The second goal addresses the appropriate, synergistic use of available methods and best practices for tolerance analysis and synthesis, at successive stages of design. Pursuit of these goals leads to the definition of a multilevel approach that enables tolerancing to be addressed at successive stages of design in an incremental fashion. The resulting design process, which we call the design for tolerance process, integrates three important domains: 1) design activities at successive stages of design; 2) assembly models that evolve continuously through the design process; 3) methods and best practices for tolerance analysis and synthesis. We demonstrate major steps of our proposed approach through a simple, yet illustrative, example. C1 Indian Inst Sci, Dept Comp Sci & Automat, Bangalore 560012, Karnataka, India. George Washington Univ, Sch Engn & Appl Sci, Washington, DC 20052 USA. Natl Inst Stand & Technol, Mfg Syst Integrat Div, Engn Design Grp, Gaithersburg, MD 20899 USA. George Washington Univ, Dept Engn Management, Washington, DC 20052 USA. RP Narahari, Y (reprint author), Indian Inst Sci, Dept Comp Sci & Automat, Bangalore 560012, Karnataka, India. NR 59 TC 14 Z9 16 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 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD DEC PY 1999 VL 15 IS 6 BP 1062 EP 1079 DI 10.1109/70.817670 PG 18 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA 278XV UT WOS:000085015000008 ER PT J AU Chou, YK Evans, CJ AF Chou, YK Evans, CJ TI White layers and thermal modeling of hard turned surfaces SO INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE LA English DT Article DE hard turning; phase transformation; surface integrity; white layer AB White layers in hard turned surfaces are identified, characterized and measured as a function of tool flank wear and cutting speed. White layer depth progressively increases with flank wear. It also increases with speed, but approaches an asymptote. A thermal model based on Jaeger's moving heat source problems (J.C. Jaeger, Moving source of heat and the temperature at sliding contacts, in: Proceedings of the Royal Society, NSW, vol. 56, pp. 203-224) is applied to simulate the temperature field in machined surfaces and to estimate white layer depth in terms of the penetration depth for a given critical temperature. The analysis shows good agreement with the trend in experimental results. White layer formation seems to be dominantly a thermal process involving phase transformation of the steel, possibly plastic strain activated; flank wear land rubbing may be a primary heat source for white layer formation. A strong material dependence of surface alteration is also observed. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Mfg Engn Lab, Gaithersburg, MD 20899 USA. RP Chou, YK (reprint author), Univ Alabama, Dept Mech Engn, 290 Hardaway Hall,Box 870276, Tuscaloosa, AL 35487 USA. NR 18 TC 131 Z9 135 U1 1 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0890-6955 J9 INT J MACH TOOL MANU JI Int. J. Mach. Tools Manuf. PD DEC PY 1999 VL 39 IS 12 BP 1863 EP 1881 DI 10.1016/S0890-6955(99)00036-X PG 19 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA 235WK UT WOS:000082565600003 ER PT J AU Elston, JA Hastie, JD Squires, D AF Elston, JA Hastie, JD Squires, D TI Market linkages between the US and Japan: an application to the fisheries industry SO JAPAN AND THE WORLD ECONOMY LA English DT Article DE price linkages; Granger causality; Japan ID COVARIANCE AB Recent trends in globalization of Pacific Basin commodity markets raises important questions concerning the nature of market integration and price linkages. This paper examines this issue by testing for price linkages between the United States and Japan for two species whose exports from the U.S. to Japan have risen considerably over the past decade. Empirical results indicate segmentation of price linkages for sablefish but probable price linkages for some thornyhead markets. Findings suggest that markets for these species may be less sensitive to price changes in Japan than would be expected based on commodity flows. (C) 1994 Elsevier Science B.V. All rights reserved. JEL classification: D0; F0; Q0. C1 Univ Cent Florida, Orlando, FL 32816 USA. Alsaka Fisheries Sci Ctr, Seattle, WA USA. SW Fisheries Ctr, La Jolla, CA USA. RP Elston, JA (reprint author), Univ Cent Florida, Orlando, FL 32816 USA. NR 20 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0922-1425 J9 JPN WORLD ECON JI Jpn. World Econ. PD DEC PY 1999 VL 11 IS 4 BP 517 EP 530 PG 14 WC Economics SC Business & Economics GA 261HV UT WOS:000084004500004 ER PT J AU Fujinawa, G Toraya, H Staudenmann, JL AF Fujinawa, G Toraya, H Staudenmann, JL TI Parallel-slit analyzer developed for the purpose of lowering tails of diffraction profiles SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID ANGULAR RESOLUTION; POWDER AB A parallel-slit analyzer (PSA) has been developed for the purpose of lowering tails in diffraction profiles from powders and thin films. In the present work, four different materials were used for the foils: sintered and hot-pressed tungsten (W), cold-worked stainless steel (SUS), beryllium bronze (Cu98Be2) and chemically surface-processed beryllium bronze (CuOx). The PSAs were tested in a parallel-beam geometry using Cu K alpha radiation collimated with a graded d-spacing parabolic multilayer mirror. The W and CuOx PSAs gave pseudo-Voigt profiles of similar to 80% Gaussian in the direct-beam case. Textured and roughened surfaces of W and CuOx foils are considered effective for depressing total-reflection effects from the surfaces of the foil materials, and consequently for lowering the tails of diffraction peaks. C1 Rigaku Corp, Xray Lab, Akishima, Tokyo 1968666, Japan. Nagoya Inst Technol, Ceram Res Lab, Tajimi 5070071, Japan. Natl Inst Stand & Technol, Dept Phys, Gaithersburg, MD 20899 USA. RP Fujinawa, G (reprint author), Rigaku Corp, Xray Lab, Akishima, Tokyo 1968666, Japan. NR 6 TC 8 Z9 8 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 1999 VL 32 BP 1145 EP 1151 DI 10.1107/S0021889899011462 PN 6 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 265DW UT WOS:000084226900013 ER PT J AU Rao, MV Berry, AK Do, TQ Ridgway, MC Chi, PH Waterman, J AF Rao, MV Berry, AK Do, TQ Ridgway, MC Chi, PH Waterman, J TI S and Si ion implantation in GaSb grown on GaAs SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GALLIUM ANTIMONIDE; BEHAVIOR; DAMAGE AB Single and multiple energy S and Si ion implantations were performed at room temperature (RT) and 200 degrees C into GaSb epitaxial layers grown on semi-insulating GaAs substrates. The implanted material was annealed with a Si3N4 cap at 400-600 degrees C for 5 min. Secondary ion mass spectrometry measurements indicated the thermal stability of the Si and S implants even for 600 degrees C annealing. Appreciable donor electrical activations of Si and S were obtained only for 200 degrees C implantation for annealing temperatures greater than or equal to 500 degrees C. For S implantation the calculated substitutional activation is similar to 50%. Rutherford backscattering/channeling measurements indicated a lattice quality that is close to the virgin level for samples annealed at 600 degrees C. N-type conduction was not observed in GaSb bulk material implanted at either RT or 200 degrees C. (C) 1999 American Institute of Physics. [S0021-8979(99)03723-8]. C1 George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. Australian Natl Univ, Dept Elect Mat Engn, Canberra, ACT 2601, Australia. 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. RI Ridgway, Mark/D-9626-2011 OI Ridgway, Mark/0000-0002-0642-0108 NR 10 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1999 VL 86 IS 11 BP 6068 EP 6071 DI 10.1063/1.371655 PG 4 WC Physics, Applied SC Physics GA 256ML UT WOS:000083729000021 ER PT J AU White, AB Lataitis, RJ Lawrence, RS AF White, AB Lataitis, RJ Lawrence, RS TI Space and time filtering of remotely sensed velocity turbulence SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB It is well known that the width of a clear-air Doppler radar spectrum can be used to estimate the small-scale variability of the wind. To do this accurately requires that all contributions to the spectral width be accounted for. Recently, an approximate formula for correcting Doppler spectral widths for spatial and temporal filtering effects was proposed. The formula assumes independent additive contributions to the spectral width from the inherent volume averaging of the radar-sampling volume and the finite measurement interval. In the present paper the approximate formula is compared to an exact triple-integral formulation in which the spatial and temporal effects are shown to be coupled in a nonlinear fashion. The required integrations are evaluated numerically and are carried out over the full range of scales in wavenumber space, in contrast to earlier work, where truncated forms of isotropic, inertial-subrange spectral forms were used to obtain a simple, closed-form expression. Comparisons show that the approximate formula provides a good approximation to the integral solution over small to moderate length scales, bur that it diverges from the integral solution at larger scales. Asymptotic limits to the exact integral formulation for large and small scales are presented. Finally, a double-integral solution that can be rapidly evaluated by any one of a number of commercial mathematics packages has been developed and shown to agree within 2% of the exact solution over all scales. C1 NOAA, ERL, ETL, Sci & Technol Corp, Boulder, CO 80303 USA. NOAA, Environm Tech Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80309 USA. RP White, AB (reprint author), NOAA, ERL, ETL, Sci & Technol Corp, R-E-ET7,325 Broadway, Boulder, CO 80303 USA. NR 11 TC 18 Z9 18 U1 3 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1999 VL 16 IS 12 BP 1967 EP 1972 DI 10.1175/1520-0426(1999)016<1967:SATFOR>2.0.CO;2 PG 6 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 271EK UT WOS:000084581100008 ER PT J AU Galand, M Roble, RG Lummerzheim, D AF Galand, M Roble, RG Lummerzheim, D TI Ionization by energetic protons in Thermosphere-Ionosphere Electrodynamics General Circulation Model SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID H-ATOM FLUXES; AURORAL ION PRECIPITATION; ELECTRON-PRECIPITATION; STATISTICAL-MODEL; TRANSPORT MODEL; ATMOSPHERE; COLLISIONS; HYDROGEN; MESOSPHERE; PATTERNS AB Originating in the magnetosphere and precipitating into the high-latitude ionosphere, energetic protons in the keV energy range are a common auroral phenomenon and can represent an important energy source for the auroral atmosphere. In global models describing the ionosphere-thermosphere interaction, keV protons have always been neglected or treated as if they were electrons. Here we investigate the effect of keV protons on both the ionospheric and thermospheric composition in the E region on a planetary scale. We present a parameterization of electron and ion production rates induced by an incident proton beam as a fast computational scheme for use in global models. The incident proton beam is assumed to have a Maxwellian distribution with characteristic energies between 1 and 20 keV. The parameterization is validated against a full proton transport code. By including these parameterized electron and ion production rates in a one dimension-in-space (1D-in-space) Thermosphere-Ionosphere Global Mean Model, we show that proton precipitation can cause a significant enhancement of the electron density, the major ion (O-2(+) and NO+) densities, and the nitric oxide density. As a result, the conductivities in the E region are also greatly increased. Using the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIE-GCM), we show that the proton precipitation, when added to the normal electron aurora, causes a large increase (up to 70%) in electron, O-2(+), and NO+ densities over much of the auroral oval. The NO density is affected in a larger area owing to the long lifetime of NO on the nightside. This first study of the influence of protons on a planetary scale clearly shows the significant impact that auroral keV protons can have on the ionospheric and thermospheric composition and the need to include proton precipitation in global models. C1 Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80301 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. RP Galand, M (reprint author), NOAA, Ctr Space Environm, 325 Broadway, Boulder, CO 80303 USA. RI Galand, Marina/C-6804-2009 NR 44 TC 26 Z9 26 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 1999 VL 104 IS A12 BP 27973 EP 27989 DI 10.1029/1999JA900374 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800001 ER PT J AU Odstrcil, D Pizzo, VJ AF Odstrcil, D Pizzo, VJ TI Distortion of the interplanetary magnetic field by three-dimensional propagation of coronal mass ejections in a structured solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HELIOSPHERIC PLASMA SHEET; MAJOR GEOMAGNETIC STORMS; SHOCK; CLOUDS; SIMULATION; STREAMS; PLANE AB A three-dimensional (3-D) numerical magnetohydrodynamic model is used to investigate the temporal and spatial evolution of large-scale solar wind (SW) disturbances. A tilted dipole outflow configuration is specified at the inner boundary near the Sun, and a structured, corotating SW flow with a monopolar interplanetary magnetic field (IMF) is established by dynamic relaxation between 0.14 and 1.04 AU. Time-dependent variation of the pressure and velocity at the inner boundary is applied to simulate injection of a coronal mass ejection (CME) near the streamer belt. In this model, magnetic disturbances arise solely from distortion of the spiral IMF by the bulk motion of CME material; embedded magnetic structures, such as magnetic clouds or flux ropes, are not considered. Numerical results show that the motion and appearance of a CME are affected by its interaction with the velocity and density structure of the background SW. This 3-D dynamic interaction also affects the orientation and magnitude of the IMF. Substantial excursions of the southward IMF component B-z are generated by three distinct mechanisms: shock compression of the IMF where the shock front is inclined to field lines, draping around the CME by mass how convection, and distortion of the IMF by rarefaction waves trailing the CME. The geoeffectiveness of the disturbance depends on the initial position of the CME with respect to the streamer belt as well as on the position of Earth with respect to the pulse centerline. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Odstrcil, D (reprint author), Astron Inst, Ondrejov 25165, Czech Republic. NR 34 TC 90 Z9 91 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 DEC 1 PY 1999 VL 104 IS A12 BP 28225 EP 28239 DI 10.1029/1999JA900319 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800021 ER PT J AU Pulkkinen, TI Baker, DN Cogger, LL Frank, LA Sigwarth, JB Kokubun, S Mukai, T Singer, HJ Slavin, JA Zelenyi, L AF Pulkkinen, TI Baker, DN Cogger, LL Frank, LA Sigwarth, JB Kokubun, S Mukai, T Singer, HJ Slavin, JA Zelenyi, L TI Spatial extent and dynamics of a thin current sheet during the substorm growth phase on December 10, 1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC-FIELD MODEL; BURSTY BULK FLOWS; PLASMA SHEET; TAIL; MAGNETOSPHERE; MAGNETOTAIL; RECONNECTION; GEOTAIL AB Multispacecraft observations are analyzed to examine the dynamics of thin current sheet evolution during the early phases of a substorm during the period 0630-0800 UT on December 10, 1996, The ground signatures showed two activations, one latitudinally localized at 0731 UT and another, larger expansion around 0800 UT. A local model consisting of two current sheets (a thin current sheet and a thicker plasma sheet) was developed utilizing two-spacecraft magnetic field measurements within the magnetotail. Extension of the thin current sheet model to the inner magnetotail shows that during most of the growth phase, the thin current sheet intensified simultaneously and at the same fate in the mid- magnetotail (similar to 30 R-E) and near geosynchronous orbit. These results show that a thin current sheet extended from the near-geostationary region to the midtail, and that the entire current sheet responded to the driving in a coherent way. Furthermore, timings suggest that the onset-associated disturbances were observable in the midtail before the ground or geosynchronous signatures. C1 Univ Calgary, Dept Phys, Calgary, AB T2N 1N4, Canada. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. Inst Space & Astronaut Sci, Kanagawa 229, Japan. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Russian Acad Sci, Space Res Inst, Moscow 117810, Russia. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. RP Pulkkinen, TI (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr, Boulder, CO 80303 USA. RI Slavin, James/H-3170-2012; Pulkkinen, Tuija/D-8403-2012 OI Slavin, James/0000-0002-9206-724X; Pulkkinen, Tuija/0000-0002-6317-381X NR 24 TC 25 Z9 25 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 DEC 1 PY 1999 VL 104 IS A12 BP 28475 EP 28490 DI 10.1029/1999JA900240 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800040 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, 325 Broadway, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1999 VL 104 IS A12 BP 28719 EP 28719 DI 10.1029/1999JA900429 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800060 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, 325 Broadway, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1999 VL 104 IS A12 BP 28721 EP 28721 DI 10.1029/1999JA900453 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800061 ER PT J AU Grayson, M Cerne, J Drew, HD Schmadel, DC Hughes, R Preston, JS Kung, PJ Vale, L AF Grayson, M Cerne, J Drew, HD Schmadel, DC Hughes, R Preston, JS Kung, PJ Vale, L TI The infrared Hall effect in YBCO: Temperature and frequency dependence of Hall scattering SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors (MOS-99) CY JUL 28-AUG 02, 1999 CL ROYAL INST TECHNOL, STOCKHOLM, SWEDEN SP Royal Inst Technol, Royal Swedish Acad Sci, Swedish Nat Sci, Engn Sci Res Councils, SAS, Gran Gustafsson Fdn, City of Stockholm HO ROYAL INST TECHNOL ID TC AB We measure the Hall angle, theta(H), in YBCO films in the far- and mid-infrared to determine the temperature and frequency dependence of the Hall scattering. Using novel modulation techniques we measure both the Faraday rotation and ellipticity induced by these films in high magnetic fields to deduce the complex conductivity tensor. We observe a strong temperature dependence of the mid-infrared Hall conductivity in sharp contrast to the weak dependence of the longitudinal conductivity. By fitting the frequency dependent normal state Hall angle to a Lorentzian theta(H)(omega) = omega(H)/(gamma(H) - i omega) we find the Hall frequency, omega(H), is nearly independent of temperature. The Hall scattering rate, gamma(H), is consistent with gamma(H) approximate to T-2 up to 200 K and is remarkably independent of IR frequency suggesting non-Fermi liquid behavior. C1 Univ Maryland, Ctr Supercond Res, College Pk, MD 20742 USA. Lab Phys Sci, College Pk, MD 20740 USA. McMaster Univ, Dept Phys, Hamilton, ON L8S 4L8, Canada. Adv Fuel Res Inc, E Hartford, CT USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Grayson, M (reprint author), Univ Maryland, Ctr Supercond Res, College Pk, MD 20742 USA. RI Grayson, Matthew/B-7159-2009; Preston, John/B-5773-2009; Hughes, Robert/O-1124-2013 OI Preston, John/0000-0002-1612-1048; NR 5 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD DEC PY 1999 VL 117 IS 5-6 BP 1055 EP 1058 DI 10.1023/A:1022522323029 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 269PK UT WOS:000084486600010 ER PT J AU Ehrman, SH Friedlander, SK Zachariah, MR AF Ehrman, SH Friedlander, SK Zachariah, MR TI Phase segregation in binary SiO2/TiO2 and SiO2/Fe2O3 nanoparticle aerosols formed in a premixed flame SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID METAL-OXIDE PARTICLES; SURFACE-AREA; FREE JET; SILICA; NANOCOMPOSITES; COALESCENCE; MORPHOLOGY; TIO2-SIO2; POWDERS; TITANIA AB Binary SiO2/TiO2 and SiO2/Fe2O3 nanoparticle (diameter < 100 nm) aerosols of varying mole ratios of Ti or Fe to Si were generated in a premixed Bunsen-type aerosol flame reactor. The distribution of species within the particles was investigated using transmission electron microscopy, electron energy loss spectrometry, x-ray diffraction, and Fourier transform infrared spectroscopy. Phase segregation was observed to varying degrees in qualitative agreement with segregation expected from binary phase diagrams for the bulk systems. Differences between the SiO2/TiO2 and SiO2/Fe2O3 systems can be explained by considering the variation in the thermodynamically stable liquid-phase solubility and differences in the ability of iron and titanium ions to substitute for silicon ions in the network structure. C1 Univ Calif Los Angeles, Dept Chem Engn, Air Qual & Aerosol Technol Lab, Los Angeles, CA 90095 USA. NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Ehrman, SH (reprint author), Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. NR 40 TC 55 Z9 55 U1 2 U2 29 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 1999 VL 14 IS 12 BP 4551 EP 4561 DI 10.1557/JMR.1999.0617 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 263ZK UT WOS:000084155000016 ER PT J AU Pan, YM Page, RA Long, GG Krueger, S AF Pan, YM Page, RA Long, GG Krueger, S TI Role of zirconia addition in pore development and grain growth in alumina compacts SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ANGLE NEUTRON-SCATTERING; MICROSTRUCTURE DEVELOPMENT; COMPUTER-SIMULATION; STATISTICAL-THEORY; POWDER COMPACTS; ZRO2 INCLUSIONS; DENSIFICATION; SINTERABILITY; KINETICS; AL2O3 AB The role of 12.4 vol% ZrO2 addition in the microstructure evolution of alumina compacts during the intermediate and final stages of sintering was investigated by means of small-angle neutron scattering measurements and stereological analysis. Both the pore-size evolution results and the grain-growth data indicate a narrowly defined onset density for the transition to the final sintering stage. The presence of ZrO2 as a second phase apparently maintains the stability of the intermediate sintering stage out to significantly higher density than in single-phase alumina and plays an important role in inhibiting grain growth and in preventing pore-grain boundary separation. The influence of the ZrO2 second phase on pore evolution, grain growth, and sinterability of the alumina-zirconia composite is discussed and compared to the behavior of single-phase alumina. The samples were prepared from commercially available powders, with naturally occurring porosity distributions, rather than from artifact (model) pore compacts prepared from nominally pure research-grade materials. The goal was to gain an improved understanding of microstructure development in real materials. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SW Res Inst, San Antonio, TX 78228 USA. RP Long, GG (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 29 TC 4 Z9 4 U1 0 U2 2 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 1999 VL 14 IS 12 BP 4602 EP 4614 DI 10.1557/JMR.1999.0623 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 263ZK UT WOS:000084155000022 ER PT J AU Kaiser, DL Vaudin, MD Rotter, LD Bonevich, JE Levin, I Armstrong, JT Roytburd, AL Schlom, DG AF Kaiser, DL Vaudin, MD Rotter, LD Bonevich, JE Levin, I Armstrong, JT Roytburd, AL Schlom, DG TI Effect of film composition on the orientation of (Ba,Sr)TiO3 grains in (Ba,Sr)(y)TiO2+y thin films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; ADSORPTION-CONTROLLED GROWTH; MOLECULAR-BEAM EPITAXY; BARIUM-TITANATE; POLYDOMAIN HETEROSTRUCTURES; BATIO3 FILMS; MGO; THERMODYNAMICS; STABILITY; SUBSTRATE AB Thin films of composition (Ba,Sr)(y)TiO2+y with 0.43 less than or equal to y less than or equal to 1.64, were deposited by metalorganic chemical vapor deposition on (100) MgO substrates at various growth conditions. X-ray diffraction and transmission electron microscopy studies showed that the films were composed of epitaxial Ba1-xSrxTiO3 (x approximate to 0.06) grains and an amorphous phase. The orientation of the tetragonal Ba1-xSrxTiO3 grains (pure a axis, pure c axis, or a mix of the two) was found to be strongly dependent upon film composition. This composition dependence is explained for the majority of the Ti-rich films by an analysis of average strains in the two-phase films, assuming a compressive strain of approximate to 1% in the amorphous phase. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Kaiser, DL (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010; Schlom, Darrell/J-2412-2013 OI Schlom, Darrell/0000-0003-2493-6113 NR 39 TC 4 Z9 4 U1 0 U2 4 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 1999 VL 14 IS 12 BP 4657 EP 4666 DI 10.1557/JMR.1999.0630 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 263ZK UT WOS:000084155000029 ER PT J AU Maranda, L Chan, C Martin, C AF Maranda, L Chan, C Martin, C TI Prorocentrum lima (Dinophyceae) in waters of the Great South Channel near Georges Bank SO JOURNAL OF PHYCOLOGY LA English DT Article DE diarrhetic shellfish poisoning; DSP; Georges Bank; Great South Channel; okadaic acid; Prorocentrum lima AB A 0-10 m plankton tow collected at one station in the Great South Channel near Georges Bank in June 1994 was rich in dinoflagellates, with the usually epibenthic Prorocentrum lima (Ehrenberg) Dodge present as the dominant species. Temperature and salinity profiles suggest that the phytoplankton population at this station may have been advected from waters on the southern flank of Georges Bank. This is the first unequivocal report of P. lima in the plankton community of the Great South Channel and its vicinity. C1 Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Univ Rhode Isl, Dept Biomed Sci, Narragansett, RI 02881 USA. NOAA, Natl Marine Fisheries Serv, Milford, CT 06460 USA. RP Maranda, L (reprint author), Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. EM lmaranda@gsosun1.gso.uri.edu NR 14 TC 8 Z9 9 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 BP 1158 EP 1161 DI 10.1046/j.1529-8817.1999.3561158.x PG 4 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 274JF UT WOS:000084762200008 ER PT J AU Millie, DF Dionigi, CP Schofield, O Kirkpatrick, G Tester, PA AF Millie, DF Dionigi, CP Schofield, O Kirkpatrick, G Tester, PA TI The importance of understanding the molecular, cellular, and ecophysiological bases of harmful algal blooms SO JOURNAL OF PHYCOLOGY LA English DT Editorial Material ID RED TIDE; DYNAMICS; NITROGEN C1 USDA ARS, New Orleans, LA 70124 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Mote Marine Lab, USDA ARS, Sarasota, FL 34236 USA. NOAA, Natl Ocean Serv, Beaufort, NC 28516 USA. RP Millie, DF (reprint author), Mote Marine Lab, USDA ARS, 1600 Ken Thompson Pkwy, Sarasota, FL 34236 USA. EM dmillie@nola.srrc.usda.gov NR 31 TC 12 Z9 15 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-3646 EI 1529-8817 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1353 EP 1355 DI 10.1046/j.1529-8817.1999.3561353.x PG 3 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700001 ER PT J AU Scholin, CA Marin, R Miller, PE Doucette, GJ Powell, CL Haydock, P Howard, J Ray, J AF Scholin, CA Marin, R Miller, PE Doucette, GJ Powell, CL Haydock, P Howard, J Ray, J TI DNA probes and a receptor-binding assay for detection of Pseudo-nitzschia (Bacillariophyceae) species and domoic acid activity in cultured and natural samples SO JOURNAL OF PHYCOLOGY LA English DT Article DE diatoms; domoic acid; Pseudo-nitzschia; receptor-binding assay; rRNA probe; sandwich hybridization; whole-cell hybridization ID TARGETED FLUORESCENT-PROBES; RIBOSOMAL-RNA; SINGLE CELLS; HYBRIDIZATION; IDENTIFICATION; AUSTRALIS; PUNGENS AB Large-subunit ribosomal RNA-targeted probes for Pseudo-nitzschia australis Frenguelli, P. multiseries (Hasle) Hasle, P, pseudodelicatissima (Hasle) Hasle, and P, pungens (Grunow) Hasle were applied to cultured and natural samples using whole-cell and sandwich hybridization. Testing of the latter method is emphasized here, and technique refinements that took place during 1996-1997 are documented. Application of the sandwich hybridization test showed that the signal intensity obtained for a given number of target cells remained constant as batch cultures of these organisms progressed from active through stationary growth phases. This suggests that cellular rRNA content for each target species remained relatively stable despite changes in growth state, Application of whole-cell and sandwich hybridization assays to natural samples showed that both methods could be used to detect wild P, australis, P. pseudo-delicatissima, and to a lesser degree P, multiseries, but detection of P. pungens was prone to error. A receptor-binding assay for domoic acid (DA) enabled detection of this toxin activity associated with a particulate fraction of the plankton and provided a context in which to view results of the rRNA probe tests. In one case, the probe for P. australis crossreacted with P, cf, delicatissima, The sample that contained the latter species also contained a low amount of DA activity, Under certain field conditions, results of whole-cell and sandwich hybridization tests disagreed, Detailed analysis of selected field samples illustrates how such situations arose. Collectively, the rRNA probe and toxin analyses suggest that manifestation of DA in the environment is possible in the absence of readily recognizable intact cells. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Natl Ocean Serv, Charleston, SC 29412 USA. Saigene Corp, Redmond, WA 98052 USA. RP Scholin, CA (reprint author), Monterey Bay Aquarium Res Inst, POB 628, Moss Landing, CA 95039 USA. EM scholin@mbari.org RI Doucette, Gregory/M-3283-2013 NR 49 TC 92 Z9 106 U1 2 U2 10 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1356 EP 1367 DI 10.1046/j.1529-8817.1999.3561356.x PG 12 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700002 ER PT J AU Parsons, ML Scholin, CA Miller, PE Doucette, GJ Powell, CL Fryxell, GA Dortch, Q Soniat, TM AF Parsons, ML Scholin, CA Miller, PE Doucette, GJ Powell, CL Fryxell, GA Dortch, Q Soniat, TM TI Pseudo-nitzschia species (Bacillariophyceae) in Louisiana coastal waters: Molecular probe field trials, genetic variability, and domoic acid analyses SO JOURNAL OF PHYCOLOGY LA English DT Article DE ASP; Bacillariophyceae; diatom; domoic acid; Gulf of Mexico; HAB; harmful algae; Pseudo-nitzschia ID DIATOM PSEUDONITZSCHIA-AUSTRALIS; TARGETED FLUORESCENT-PROBES; WEST-COAST; PUNGENS; MULTISERIES; SHELLFISH; BAY; PSEUDODELICATISSIMA; IDENTIFICATION; PHYTOPLANKTON AB An 18-month field survey of the Pseudo-nitzschia population present in Louisiana coastal waters was conducted comparing species abundance estimates by novel fluorescent molecular probes (16S large subunit rDNA oligonucleotide sequences) with traditional electron and differential-interference light microscopy, While the probe and microscopic analyses agreed on the presence or absence of four common Pseudo-nitzschia species (P, multiseries (Hasle) Hasle, P, pseudodelicatissima (Hasle) Hasle, P, delicatissima (P.T. Cleve) Heiden, and P. pungens (Grunow) Hasle in 66% of the samples analyzed, the probes gave conflicting results with the microscopic methods in the remaining 34% of the samples. The majority of the discrepancies appear to be because of genetic variation within the Pseudo-nitzschia population, especially in P. pseudodelicatissima, indicating that the Monterey Bay Pseudo-nitzschia spp, may not be appropriate reference strains for distinguishing Louisiana Pseudo-nitzschia spp. Additionally, P, pseudodelicatissima has been associated with domoic acid (DA) activity in three field samples, at levels up to 22 times higher than the highest value given in other published reports of DA production by this species. The contemporaneous existence of multiple strains of P. pseudodelicatissima (toxic and nontoxic) presents new challenges to the study of the ecophysiology and population dynamics of this bloom-forming species. C1 Univ Hawaii, Dept Marine Sci, Hilo, HI 96720 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Med Univ S Carolina, Dept Marine Biomed & Environm Sci, Charleston, SC 29412 USA. NOAA, Marine Biotoxins Program, Ctr Coastal Ecosyst Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. Univ Texas, Dept Bot, Austin, TX 78713 USA. Univ Texas, Dept Marine Sci, Austin, TX 78713 USA. Louisiana Univ Marine Consortium, Chauvin, LA 70344 USA. Nicholls State Univ, Dept Biol Sci, Thibodaux, LA 70310 USA. RP Parsons, ML (reprint author), Univ Hawaii, Dept Marine Sci, 200 W Kawili St, Hilo, HI 96720 USA. EM mparsons@hawaii.edu RI Doucette, Gregory/M-3283-2013 NR 55 TC 65 Z9 67 U1 1 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1368 EP 1378 DI 10.1046/j.1529-8817.1999.3561368.x PG 11 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700003 ER PT J AU Litaker, RW Tester, PA Colorni, A Levy, MG Noga, EJ AF Litaker, RW Tester, PA Colorni, A Levy, MG Noga, EJ TI The phylogenetic relationship of Pfiesteria piscicida, Cryptoperidiniopsoid sp Amyloodinoum ocellatum and a Pfiesteria-like dinoflagellate to other dinoflagellates and apicomplexans SO JOURNAL OF PHYCOLOGY LA English DT Article DE Amyloodinium ocellatum; Cryptoperidiniopsoid sp.; dinoflagellate; evolution; parasite; Pfiesteria piscicida; Small Subunit (SSU) rRNA; 18S ID SUBUNIT RIBOSOMAL-RNA; FISH KILLS; TOXIC DINOFLAGELLATE; ESTUARINE FISH; GENE SEQUENCE; LIFE-CYCLE; DNA; SUBSTITUTION; PYRROPHYTA; BEHAVIOR AB The taxonomic relationship between heterotrophic and parasitic dinoflagellates has not been studied extensively at the molecular level. In order to investigate these taxonomic relationships, we sequenced the small subunit (SSU) ribosomal RNA gene of Pfiesteria piscicida (Steidinger et Burkholder), a Pfiesteria-like dinoflagellate, Cryptoperidiniop-soid sp,, and Amyloodinium ocelllatum (Brown) and submitted those sequences to GenBank, Pfiesteria piscicida and Cryptoperidiniopsoid sp, are heterotrophic dinoflagellates, purportedly pathogenic to fish, and A, ocellatum, a major fish pathogen, has caused extensive economic losses in both the aquarium and aquaculture industries. The pathogenicity of the Pfiesteria-like dinoflagellate is unknown at this time, but its growth characteristics and in vitro food preferences are similar to those of P, piscicda. The SSU sequences of these species were aligned with the other full-length dinoflagellate sequences, as well as those of representative apicomplexans and Perkinsus species, the groups most closely related to dinoflagellates. Phylogenetic analyses indicate that Cryptoperidiniopsoid sp,, P, piscicida, and the Pfiesteria-like dinoflagellate are closely related and group into the class Blastodiniphyceae, as does A, ocellatum. None of the species examined were closely related to the apicomplexans or to Perkinsus marinus, the parasite that causes "Dermo disease" in oysters. The overall phylogenetic analyses largely supported the current class and subclass groupings within the dinoflagellates. C1 Univ N Carolina, Program Mol Biol & Biotechnol, Chapel Hill, NC 27599 USA. NOAA, Natl Ocean Serv, Beaufort, NC 28516 USA. Israel Oceanog & Limnol Res, Natl Ctr Mariculture, IL-88112 Elat, Israel. N Carolina State Univ, Coll Vet Med, Dept Microbiol Pathol & Parasitol, Raleigh, NC 27606 USA. N Carolina State Univ, Coll Vet Med, Dept Clin Sci, Raleigh, NC 27606 USA. RP Litaker, RW (reprint author), Univ N Carolina, Program Mol Biol & Biotechnol, 442 Taylor Hall, Chapel Hill, NC 27599 USA. EM wayne_litaker@med.unc.edu NR 60 TC 68 Z9 73 U1 0 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-3646 EI 1529-8817 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1379 EP 1389 DI 10.1046/j.1529-8817.1999.3561379.x PG 11 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700004 ER PT J AU Plumley, FG Wei, ZY Toivanen, TB Doucette, GJ Franca, S AF Plumley, FG Wei, ZY Toivanen, TB Doucette, GJ Franca, S TI Tn5 mutagenesis of Pseudomonas stutzeri SF/PS, a bacterium associated with Alexandrium lusitanicum (dinophyceae) and paralytic shellfish poisoning SO JOURNAL OF PHYCOLOGY LA English DT Article DE Alexandrium lusitanicum; dinoflagellate; harmful algal bloom; paralytic shellfish poisoning; Pseudomonas stutzeri SF/PS; transconjugation ID RANGE CLONING VECTOR; TRANSFORMATION; SYSTEM; TOXINS; DERIVATIVES; RESISTANCE; PBBR1MCS; CULTURE; BIOLOGY AB It is becoming increasingly clear that bacteria can play an important role in the toxin and population dynamics of harmful algal bloom (HAB) events. In this paper, we document protocols and strategies that can be used to identify bacterial genes involved in either the production of toxic compounds and/or the establishment and maintenance of relationships between bacteria and algae, The protocols we tested involved transposon mutagenesis and complementation with broad-host-range plasmids, We tested six bacterial strains thought to be involved, either directly or indirectly, in the production of toxins associated with paralytic shellfish poisoning: (PSP), Five strains were resistant to transformation under the growth conditions used. However, a single strain, Pseudomonas stutzeri SF/PS, was readily transformed when grown under appropriate conditions. This bacterium has been shown to accumulate PSP toxins and to increase toxin production when added to axenic cultures of a toxic dinoflagellate, Alexandrium lusitanicum. We conclude that a transposon mutagenesis strategy can be used to identify genes involved in HAB events. C1 Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. Univ Alaska, Dept Chem & Biochem, Fairbanks, AK 99775 USA. NOAA, Marine Biotoxins Program, Natl Ocean Serv, Charleston, SC 29412 USA. Med Univ S Carolina, Charleston, SC 29412 USA. Inst Nacl Saude, P-1649016 Lisbon, Portugal. RP Plumley, FG (reprint author), Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. EM fffgp@uaf.edu RI Doucette, Gregory/M-3283-2013 NR 36 TC 5 Z9 6 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1390 EP 1396 DI 10.1046/j.1529-8817.1999.3561390.x PG 7 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700005 ER PT J AU Van Dolah, FM Leighfield, TA AF Van Dolah, FM Leighfield, TA TI Diel phasing of the cell-cycle in the Florida red tide dinoflagellate, Gymnodinium breve SO JOURNAL OF PHYCOLOGY LA English DT Article DE cell-cycle; circadian rhythm; cyclin-dependent kinase; flow cytometry; Gymnodinium breve ID CRYPTHECODINIUM-COHNII BIECHELER; DNA-SYNTHESIS; MARINE-PHYTOPLANKTON; GONYAULAX-POLYEDRA; DIVISION; KINASE; PROTEIN; LIGHT; DARK AB The diel cycle is a key regulator of the cell-cycle in many dinoflagellates, but the mechanisms by which the diel cycle entrains the cell-cycle remain poorly understood. In this study, we describe diel phasing of the cell-cycle in the Florida red tide dinoflagellate Gymnodinium breve Davis, determine the diel cue which serves to entrain the cell-cycle, and provide evidence for the presence of cyclin-dependent kinase (CDK), a cell-cycle regulator which may be responsive to this cue. Four laboratory isolates from the West Coast of Florida were compared. When gown on a 16:8 h LD cycle, all isolates displayed phased cell division, with the S-phase beginning 6-8 h into the light phase, and mitosis following 12-14 h later, as determined by flow cytometry, A naturally occurring bloom of G. breve, studied over one diel cycle, displayed diel cell-cycle phasing similar to that in the laboratory cultures, with the S-phase beginning during daylight and the peak of mitosis occurring approximately 4 h after sunset. In the laboratory cultures, the dark/light "dawn" transition was found to provide the diel cue which serves to entrain the G, breve cell-cycle, whereas the light/ dark "dusk" transition did not appear to be involved. Evidence for the presence of CDK in G. breve was obtained using two approaches: (1) identification of a 34-kDa protein, immunoreactive to an antibody against a conserved amino acid sequence (alpha-PSTAIR) unique to the CDK protein family and (2) inhibition of the cell-cycle by olomoucine, a selective CDK inhibitor. Together, these results provide the basis from which one can begin addressing mechanisms by which the diel cycle regulates the cell-cycle in G. breve. C1 NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Van Dolah, FM (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 28 TC 43 Z9 43 U1 0 U2 2 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1404 EP 1411 DI 10.1046/j.1529-8817.1999.3561404.x PG 8 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700007 ER PT J AU Lohrenz, SE Fahnenstiel, GL Kirkpatrick, GJ Carroll, CL Kelly, KA AF Lohrenz, SE Fahnenstiel, GL Kirkpatrick, GJ Carroll, CL Kelly, KA TI Microphotometric assessment of spectral absorption and its potential application for characterization of harmful algal species SO JOURNAL OF PHYCOLOGY LA English DT Article DE absorption efficiency; harmful algal blooms; integrating sphere; microphotometry; phytoplankton; pigments; spectral absorption ID PHYTOPLANKTON ABSORPTION; DUNALIELLA-TERTIOLECTA; LIGHT-ABSORPTION; QUANTUM YIELD; FLUORESCENCE; VARIABILITY; EFFICIENCY; GROWTH AB A comparison was made of microphotometric measurements and spectrophotometric measurements of particulate spectral absorption of four algal species, including the chlorophyte Dunaliella tertiolecta Butcher; a nontoxic dinoflagellate, Amphidinium carterae Hulburt; a diatom, Chaetoceros gracilis Schutt; and a toxic dinoflagellate, Gymnodinium breve Steidinger, Particulate spectral absorption of monospecies cultures was estimated as the product of the average absorption efficiency factor, Q(a), determined by microphotometry, the cellular cross-sectional area, and the cell number density. Estimates of particulate spectral absorption from microphotometric measurements were, in most cases, within one standard deviation of values determined from spectrophotometric measurements of algal suspensions. Estimates of Q(a)(675) were shown to be consistent with values reported in previous studies for cells of similar size and pigmentation and were consistent with theoretical predictions. Absorption spectra of mixtures of C. gracilis and G. breve were numerically decomposed into contributions by absorption signatures of monospecies cultures using either spectrophotometric or microphotometric measurements as the basis for end members. Modeled contributions assigned to either species displayed trends consistent with the actual proportions contributed to the spectrum by each algal culture. However, the technique was sensitive to measurement variability, which reduced the level of agreement between modeled and actual contributions. The utility of this approach for identification of algal taxa will depend on the degree to which algal spectral absorption signatures differ and the capabilities for acquiring high-resolution data with low signal-to-noise ratios. C1 Univ So Mississippi, Dept Marine Sci, Stennis Space Ctr, MS 39529 USA. NOAA, Great Lakes Environm Res Lab, Muskegon, MI 49441 USA. Mote Marine Lab, Sarasota, FL 34236 USA. RP Lohrenz, SE (reprint author), Univ So Mississippi, Dept Marine Sci, Stennis Space Ctr, MS 39529 USA. OI Lohrenz, Steven/0000-0003-3811-2975 NR 30 TC 13 Z9 13 U1 0 U2 3 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1438 EP 1446 DI 10.1046/j.1529-8817.1999.3561438.x PG 9 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700011 ER PT J AU Doucette, GJ McGovern, ER Babinchak, JA AF Doucette, GJ McGovern, ER Babinchak, JA TI Algicidal bacteria active against Gymnodinium breve (Dinophyceae). I. Bacterial isolation and characterization of killing activity SO JOURNAL OF PHYCOLOGY LA English DT Article DE algicidal bacteria; harmful algal bloom; Gymnodinium; red tide ID RED TIDE; MARINE; HETEROSIGMA; JAPAN AB Interactions between bacteria and species of harmful and/or toxic algae are potentially important factors affecting both the population dynamics and the toxicity of these algae, Recent reports of bacteria lethal to certain harmful algal bloom (HAB) species, coupled with a rapidly evolving interest in attempting to minimize the adverse effects of HABs through various prevention, control, and mitigation strategies, have focused attention on defining the role of algicidal bacteria in bloom termination, The aim of the present study was to determine whether algicidal bacteria active against Gymnodinium breve Davis, a dinoflagellate responsible for frequent and protracted red tides in the Gulf of Mexico, are present in the waters of the west Florida shelf. To date, we have isolated two bacterial strains from this region lethal to G. breve and have begun to characterize the algicidal activity of one of these strains, 41-DBG2, This bacterium, a yellow-pigmented, gramnegative rod, was isolated from waters containing no detectable G, breve cells, suggesting that such bacteria are part of the ambient microbial community and are not restricted to areas of high G, breve abundance. Strain 41-DBG2 produced a dissolved algicidal compound(s) that was released into the growth medium, and the algicide was effective against the four Gulf of Mexico G, breve isolates tested as well as a closely related HAB species that also occurs in this region, Gymnodinium mikimotoi Miyake et Kominami ex Oda, Nonetheless, data showing that a nontoxic isolate of Gymnodinium sanguineum Hirasaka from Florida Bay was not affected indicate that the algicidal activity of this bacterium does exhibit a degree of taxonomic specificity. Our efforts are currently being directed at resolving several critical issues, including the identity of the algicide(s), the mechanisms regulating its production and ability to discriminate between target algal species, and how the growth rate of 41-DBG2 is affected by the presence of G, breve cells, We have also proposed a conceptual model for interactions between algicidal bacteria and their target species to serve as a testable framework for ensuing field studies. C1 NOAA, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. Med Univ S Carolina, Charleston, SC 29412 USA. RP Doucette, GJ (reprint author), NOAA, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, 219 Ft Johnson Rd, Charleston, SC 29412 USA. RI Doucette, Gregory/M-3283-2013 NR 22 TC 103 Z9 121 U1 2 U2 22 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD DEC PY 1999 VL 35 IS 6 SU S BP 1447 EP 1454 DI 10.1046/j.1529-8817.1999.3561447.x PG 8 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 275PN UT WOS:000084828700012 ER PT J AU Johnson, GC McPhaden, MJ AF Johnson, GC McPhaden, MJ TI Interior pycnocline flow from the subtropical to the equatorial Pacific Ocean SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID WIND-DRIVEN CIRCULATION; SUBSURFACE COUNTERCURRENTS; TROPICAL PACIFIC; MINDANAO CURRENT; TRITIUM MAXIMUM; SOUTH-PACIFIC; NORTH PACIFIC; SOURCE WATERS; MEAN WATER; VARIABILITY AB Interior circulation pathways from the subtropics to the equator are markedly different in the Northern and Southern Hemispheres of the Pacific Ocean. In the North Pacific the pycnocline shoals and strengthens dramatically under the intertropical convergence zone, separating the North Equatorial Current from the North Equatorial Countercurrent. While the high potential vorticity between these currents would intuitively seem to inhibit meridional water properly exchange between the subtopics and the equator, transient tracer analyses and some modeling studies have suggested an interior pathway from the subtropics to the equator in the pycnocline of the central North Pacific. This study delineates this pathway and estimates an upper bound for its magnitude at 5 (+/-1) x 10(9) kg s(-1). In contrast, the southern branch of the South Equatorial Current clearly brings pycnocline water estimated at 15 (+/-1) x 10(9) kg s(-1) from the southern subtropics directly to the equator in the South Pacific through an interior region of low and relatively uniform potential vorticity. In both hemispheres, these interior pathways extend downward as far as the lightest waters of the equatorial pycnostad. The subsurface countercurrents flanking the pycnostad form the equatorward limbs of tropical subsurface cyclonic gyres. These deep gyres are consistent with the absence of interior ventilation of the equator from the subtropics below the pycnocline, Measured and derived fields from a hydrographic climatology are presented on neutral surfaces and in meridional-vertical sections to show that salinity, potential vorticity, and acceleration potential are ail consonant with these arguments, The vertical extent of interior communication is also in agreement with the transient tracer results. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Johnson, GC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE,Bldg 3, Seattle, WA 98115 USA. RI Johnson, Gregory/I-6559-2012; McPhaden, Michael/D-9799-2016 OI Johnson, Gregory/0000-0002-8023-4020; NR 41 TC 142 Z9 150 U1 0 U2 20 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 1999 VL 29 IS 12 BP 3073 EP 3089 DI 10.1175/1520-0485(1999)029<3073:IPFFTS>2.0.CO;2 PG 17 WC Oceanography SC Oceanography GA 273CT UT WOS:000084690300006 ER PT J AU Ezer, T AF Ezer, T TI Decadal variabilities of the upper layers of the subtropical North Atlantic: An ocean model study SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SST ANOMALIES DRIVEN; SEA-LEVEL; INTERPENTADAL VARIABILITY; INTERDECADAL VARIABILITY; HEAT-FLUX; CIRCULATION; SIMULATION; ALTIMETER; WAVES; GYRE AB Numerical simulations of the Atlantic Ocean during the period 1950 to 1989, using a sigma coordinate, free surface numerical model, show long-term variabilities in the upper ocean subtropical gyre similar to those obtained from observations. The simulations show how westward propagating planetary waves, originated in the eastern North Atlantic, affect interdecadal variabilities of ocean properties such as the Bermuda sea level, the Gulf Stream position and strength. and subsurface temperature anomalies in the western North Atlantic. Special attention is given to the dramatic sea level drop at Bermuda in the early 1970s, which is accompanied by cooling of subsurface layers in the western North Atlantic and a northward shift and weakening of the Gulf Stream. Following these events, between 1970 and 1980, the cold temperature anomalies in the upper layers of the western North Atlantic slowly propagated eastward and downward: the strongest propagating signal in the model is found at 200-m depth, suggesting that advection of anomalies downstream by the Gulf Stream current and changes in winter mixing are involved. Significant correlations were found between the sea level anomalies at Bermuda and sea level anomalies in the eastern North Atlantic up to eight years earlier. Sensitivity experiments with different atmospheric forcing fields are used to study the ocean response to observed sea surface temperature and wind stress anomalies. It is shown that on decadal timescales, the ocean model responds in a linear fashion to the combined effect of SST and wind stress anomalies, a fact that might be exploited in future climate prediction studies. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Ezer, T (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. OI Ezer, Tal/0000-0002-2018-6071 NR 40 TC 35 Z9 36 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD DEC PY 1999 VL 29 IS 12 BP 3111 EP 3124 DI 10.1175/1520-0485(1999)029<3111:DVOTUL>2.0.CO;2 PG 14 WC Oceanography SC Oceanography GA 273CT UT WOS:000084690300009 ER PT J AU Scott, JD Alexander, MA AF Scott, JD Alexander, MA TI Net shortwave fluxes over the ocean SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SURFACE RADIATION BUDGET; NORTH PACIFIC; CIRCULATION; TEMPERATURE; REANALYSES; PROJECT; DATASET AB Net surface shortwave fluxes (Q(sw)) computed from National Aeronautics and Space Administration/Langley satellite data are compared with Q(sw) from reanalyses of the European Centre for Medium-Range Weather Forecasts (ERA) and the National Centers for Environmental Prediction (NCEP). The mean and variability of Q(sw) is examined for the period 1983-91, with a focus on the tropical and summer hemisphere oceans during June, July, August (JJA) and December, January, February (DJF). Both reanalyses exhibit a positive bias, indicating too much sunlight is absorbed at the surface, in regions where low-level stratiform clouds are most common. but a negative bias in regions where cumuliform clouds are the dominant cloud type. The ERA has a greater intermonthly variability during JJA than the satellite data over most of the Pacific, especially north of 40 degrees N and in the central and eastern equatorial Pacific. The NCEP variability in JJA is also larger than the satellite estimates over the North Pacific and the eastern equatorial Pacific, but is smaller over most of the western tropical and subtropical Pacific. During DJF, the ERA has more realistic variability in shortwave fluxes over the tropical oceans than the NCEP reanalysis, which underestimates the variability in the tropical Pacific and the Indian Ocean by a factor of 2. Ocean models using atmospheric forcing from reanalyses will be impacted not only by regional and seasonal Q(sw) biases but also by differences in Q(sw) variability. It is estimated that the largest impacts on SST due to differences in variability are in the North Pacific, eastern tropical Pacific, and western Atlantic during JJA and in the Indian Ocean and the tropical Pacific and Atlantic during DJF. C1 NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, RECDI, Boulder, CO 80303 USA. RP Scott, JD (reprint author), NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, RECDI, 325 Broadway, Boulder, CO 80303 USA. RI Alexander, Michael/A-7097-2013 OI Alexander, Michael/0000-0001-9646-6427 NR 25 TC 15 Z9 15 U1 0 U2 0 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 1999 VL 29 IS 12 BP 3167 EP 3174 DI 10.1175/1520-0485(1999)029<3167:NSFOTO>2.0.CO;2 PG 8 WC Oceanography SC Oceanography GA 273CT UT WOS:000084690300014 ER PT J AU Paraso, MC Ford, SE Powell, EN Hofmann, EE Klinck, JM AF Paraso, MC Ford, SE Powell, EN Hofmann, EE Klinck, JM TI Modeling the MSX parasite in eastern oyster (Crassostrea virginica) populations. II. Salinity effects SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE MSX; model; eastern oyster; Crassostrea virginica; Haplosporidium nelsoni; Delaware Bay; salinity ID HAPLOSPORIDIUM-NELSONI MSX; DELAWARE ESTUARY; REGULAR SPORULATION; AMERICAN OYSTER; VARIABILITY; MANAGEMENT; MORTALITY; STOCKS; BAY AB An oyster population model coupled with a model for Haplosporidium nelsoni, the causative agent of the oyster disease MSX, was used with salinity time-series constructed from Delaware River flow measurements to study environmentally-induced variations in the annual cycle of this disease in Delaware Bay oyster populations. Model simulations for the lower Bay (high salinity) sire reproduced the annual cycle observed in lower Delaware Bay. Simulations at both upper Bay (low salinity) and lower Bay sites produced prevalences and intensities that were consistent with field observations. At all sites, low freshwater discharge resulted in increased disease levels, whereas high freshwater discharge produced decreased levels. At upper Bay sites, simulated changes in runoff produced high variability in disease prevalence; in the lower Bay, they produced a much lesser effect. Changes in salinity within the 10-20 ppt range produced the greatest changes in disease levels and patterns. Simulated shifts in timing of the spring runoff from March to either February or May affected the mid-Bay (13-19 ppt) only. A February runoff reduced the spring prevalence peak and caused a complete loss of systemic infections. In contrast, a May discharge occurred too late to affect parasite proliferation in the spring so that the spring peak was higher than average. Almost 100% of the infections were systemic by June, which resulted in high oyster mortality during July at this site. Model results indicate thar parasite infection intensity under changing salinity is more complex than a simple function of salinity as it affects parasite proliferation and death rates within the oyster, and that the rate of infection is most likely reduced at low salinity. The simulated results demonstrate the ability of the model to reproduce field measurements and its usefulness in elucidating the association between the magnitude and timing of Delaware River discharge, its associated salinity variations, and the H. nelsoni annual cycle. C1 NOAA, NESDIS, Natl Oceanog Data Ctr, Coastal Ocean Lab, Silver Spring, MD 20910 USA. Rutgers State Univ, Haskin Shellfish Res Lab, Port Norris, NJ 08349 USA. Old Dominion Univ, Ctr Coastal Phys Oceanog, Norfolk, VA 23529 USA. RP Paraso, MC (reprint author), NOAA, NESDIS, Natl Oceanog Data Ctr, Coastal Ocean Lab, Silver Spring, MD 20910 USA. NR 40 TC 21 Z9 21 U1 1 U2 6 PU NATL SHELLFISHERIES ASSOC PI GROTON PA C/O DR. SANDRA E. SHUMWAY, UNIV CONNECTICUT, 1080 SHENNECOSSETT RD, GROTON, CT 06340 USA SN 0730-8000 EI 1943-6319 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 1999 VL 18 IS 2 BP 501 EP 516 PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 276YM UT WOS:000084906000022 ER PT J AU Messick, GA Jordan, SJ Van Heukelem, WF AF Messick, GA Jordan, SJ Van Heukelem, WF TI Salinity and temperature effects on Hematodinium sp in the blue crab Callinectes sapidus SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE Hematodinium sp.; Callinectes sapidus; salinity; temperature; parasite ID LOBSTER NEPHROPS-NORVEGICUS; PARASITIC DINOFLAGELLATE; CHIONOECETES-BAIRDI; FISHERY; DISEASE; MANAGEMENT; INFECTION; BAY; PREVALENCE; MORTALITY AB The parasitic dinoflagellate Hematodinium sp. infects and causes mortalities in blue crabs Callinectes sapidus Rathbun 1896 from high salinity coastal embayments. The seasonal infection cycle and apparent salinity and temperature requirements for infections reported from wild crab populations indicate that environmental factors influence the parasite's ability to proliferate within crab hemolymph. A series of experiments held crabs at various water temperatures and salinities to assay infection intensity and crab survival. There was a significant increase in mean intensity in infected crabs held in ambient 15-9 degrees C seawater for 32 days; at temperatures below 9 degrees C, mean intensity diminished. Mean intensity decreased significantly in infected crabs held in 10% or 29% artificial seawater at 9 degrees C for 73 days; the decrease was significantly greater at 10% than at 29%. Mean intensity increased in infected crabs held in 22% seawater at either 12 or 16 degrees C. Presumably uninfected crabs held at 22 degrees C presented infections after 14 days. No infections were transmitted by exposure of uninfected crabs to infected crabs after 85 days. Low water temperature and salinity appear to limit the proliferation of Hematodinium sp. in blue crab hemolymph. Apparently uninfected crabs from endemic areas can carry pre-patent or latent infections. C1 Natl Ocean Serv, NOAA, Cooperat Oxford Lab, Oxford, MD 21654 USA. Maryland Dept Nat Resources, Cooperat Oxford Lab, Oxford, MD 21654 USA. Univ Maryland, Ctr Environm Sci, Horn Point Lab, Cambridge, MD 21613 USA. RP Messick, GA (reprint author), Natl Ocean Serv, NOAA, Cooperat Oxford Lab, Oxford, MD 21654 USA. NR 35 TC 24 Z9 26 U1 1 U2 7 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 1999 VL 18 IS 2 BP 657 EP 662 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 276YM UT WOS:000084906000040 ER PT J AU Morton, SL Leighfield, TA Haynes, BL Petitpain, DL Busman, MA Moeller, PDR Bean, L Mcgowan, J Hurst, JW Van Dolah, FM AF Morton, SL Leighfield, TA Haynes, BL Petitpain, DL Busman, MA Moeller, PDR Bean, L Mcgowan, J Hurst, JW Van Dolah, FM TI Evidence of diarrhetic shellfish poisoning along the coast of Maine SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article ID OKADAIC ACID; TOXIN AB Following the occurrence of several unexplained incidents of shellfish-related gastroenteritis, field studies were conducted to determine if diarrhetic shellfish poisoning (DSP) toxins are present in Maine coastal waters. A protein phosphatase inhibition assay for DSP toxins revealed the presence of low levels of okadaic acid-like activity in blue mussels (Mytilus edulis) at sampling sites in the Frenchman Bay-Eastern Bay region. All other sires along the Maine coast were negative. Phytoplankton populations from this area were dominated by Dinophysis norvegica, a known toxic species. Two additional known toxic species of Dinophysis were also found: Dinophysis acuminata and D. rotunda. However, all plankton samples were negative for okadaic acid-like activity. Examination of the epiphytic communities from areas where mussels showed okadaic acid-like activity revealed the presence of the toxic dinoflagellate Prorocentrum lima in association with the brown alga, Ectocarpus sp. Epiphytic samples rich in P. lima were active in the phosphatase inhibition assay; Subsequent analysis of these samples using LC-MS/MS identified the presence of dinophysis toxin-l (DTX-1). Empty P. lima thecae identified in the digestive tract of mussels from these areas indicate that P. lima is consumed by mussels. This is the first confirmation of P. lima in northern United States coastal waters and identifies DSP as a potential public health issue. C1 Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, NOAA, Charleston, SC 29412 USA. Maine Dept Marine Resources, W Boothbay Harbor, ME 04575 USA. NIEHS, Marine & Freshwater Biomed Sci Ctr, Mt Desert Isl Biol Lab, Salsbury Cove, ME 04672 USA. RP Morton, SL (reprint author), Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, NOAA, Charleston, SC 29412 USA. NR 17 TC 18 Z9 18 U1 1 U2 5 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 1999 VL 18 IS 2 BP 681 EP 686 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 276YM UT WOS:000084906000043 ER PT J AU Naugolnykh, KA Egerev, SV Esipov, IB Matveev, KA AF Naugolnykh, KA Egerev, SV Esipov, IB Matveev, KA TI Nonlinear propagation of laser-generated sound pulses in a water and granular medium SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Nonlinear propagation of finite-amplitude acoustic pulse in water and through a sample of water-saturated granular medium is considered. To generate high-intensity acoustic pulses laser generation of sound was used. The region of fluid perturbed by the laser acts as a volume-distributed source. In a fluid with weak light attenuation, a cylindrical source could be formed by a narrow laser beam. The nonlinear distortion of the cylindrical finite-amplitude wave in water is investigated. The measured rate of distortion corresponds to that calculated:in the approximation of nonlinear acoustics. In a strongly light-absorbing medium, a wide (compared to the typical sound wavelength) laser beam produces a circular planar source. Such a source produces acoustical pulses of amplitude up to 3 MPa and duration about I mu s in different fluids. This source was used to investigate the propagation of high-intensity wide frequency band sound signals:in a sample of water-saturated cobalt-manganese crust (CMC). Specific acoustical features of:the crust such as nonlinear sound pulse distortion and the frequency dependance of attenuation, varying with the amplitude, are considered. Theoretical interpretation of the results is given. (C) 1999 Acoustical Society of America. [S0001-4966(99)04512-9]. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80303 USA. N Andreev Acoust Inst, Moscow 117036, Russia. RP Naugolnykh, KA (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. RI Egerev, Sergey/J-2310-2016 OI Egerev, Sergey/0000-0001-6998-1060 NR 25 TC 8 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3135 EP 3142 DI 10.1121/1.428167 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700012 ER PT J AU Stafford, KM Nieukirk, SL Fox, CG AF Stafford, KM Nieukirk, SL Fox, CG TI Low-frequency whale sounds recorded on hydrophones moored in the eastern tropical Pacific SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID GULF-OF-CALIFORNIA; BALAENOPTERA-PHYSALUS; BLUE WHALE; VOCALIZATIONS; MUSCULUS; FINBACK; MEXICO; BRYDE; EDENI; CALLS AB An array of autonomous hydrophones moored in the eastern tropical Pacific was monitored for one year to examine the occurrence of whale calls in this region. Six hydrophones which recorded from 0-40 Hz were placed at 8 degrees N, 0 degrees, and 8 degrees S along longitudes 95 degrees W and 110 degrees W. Seven types of sounds believed to be produced by large whales were detected. These sound types were categorized as either moan-type (4) or pulse-type (3) calls. Three of the moan-type calls, and probably the fourth, may be attributed to blue whales. The source(s) of the remaining calls is unknown. All of the call types studied showed seasonal and geographical variation. There appeared to be segregation between northern and southern hemispheres, such that call types were recorded primarily on the northern hydrophones in the northern winter and others recorded primarily on the southern hemisphere hydrophones in the southern winter. More calls and more call types were recorded on the eastern hydrophones than on the western hydrophones. [S0001-4966(99)06012-9]. C1 Oregon State Univ, Hatfield Marine Sci Ctr, COAS, CIMRS, Newport, OR 97365 USA. Pacific Marine Environm Lab, NOAA, Newport, OR 97365 USA. RP Oregon State Univ, Hatfield Marine Sci Ctr, COAS, CIMRS, 2030 S Marine Sci Dr, Newport, OR 97365 USA. NR 52 TC 54 Z9 59 U1 0 U2 2 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3687 EP 3698 DI 10.1121/1.428220 PG 12 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700067 PM 10615707 ER PT J AU Gianfrani, L Fox, RW Hollberg, L AF Gianfrani, L Fox, RW Hollberg, L TI Cavity-enhanced absorption spectroscopy of molecular oxygen SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID RING-DOWN SPECTROSCOPY; SYMMETRIZATION POSTULATE; SENSITIVE DETECTION; OPTICAL CAVITY; MODULATION; TRANSITION; RESONATOR; BANDS AB A high-finesse optical cavity was employed to perform highly sensitive spectroscopy of molecular oxygen at wavelengths near 763 nm. An equivalent absorption length of similar to 1 km was obtained by a 26-cm-long optical cavity with a finesse of 6000. An extended cavity diode laser was frequency locked to the cavity, and pure absorption profiles were recovered by monitoring of the cavity transmission during continuous scans of the cavity resonance through O-2 rotational lines, allowing a detailed investigation of the line shapes. Phase modulation of the laser at a frequency equal to the cavity free-spectral-range frequency was employed for detection of weak absorption signals inside the cavity. A minimum detectable absorption coefficient of 6.9 x 10(-11) cm(-1) Hz(-1/2) was measured. Finally, a test of the symmetrization postulate in O-16 nuclei was demonstrated. [S0740-3224(99)00112-5]. C1 Univ Naples Federico II, Dipartimento Sci Ambientali, I-81100 Naples, Italy. Ist Nazl Fis Mat, Unita Napoli, I-81100 Naples, Italy. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Gianfrani, L (reprint author), Univ Naples Federico II, Dipartimento Sci Ambientali, Via Arena 22, I-81100 Naples, Italy. OI Gianfrani, Livio/0000-0002-2241-7603 NR 25 TC 82 Z9 84 U1 2 U2 17 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 1999 VL 16 IS 12 BP 2247 EP 2254 DI 10.1364/JOSAB.16.002247 PG 8 WC Optics SC Optics GA 262JT UT WOS:000084064300011 ER PT J AU Ma, LS Ye, J Dube, P Hall, JL AF Ma, LS Ye, J Dube, P Hall, JL TI Ultrasensitive frequency-modulation spectroscopy enhanced by a high-finesse optical cavity: theory and application to overtone transitions of C2H2 and C2HD SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID 1.5 MU-M; SATURATED-ABSORPTION; ABSOLUTE FREQUENCY; 532 NM; ACETYLENE; LASER; IODINE; STABILIZATION; STABILITY; SPECTRUM AB The sensitivity of FM spectroscopy can be dramatically enhanced by location of the sample in a high-finesse cavity, for example, similar to 5 orders of magnitude in this study. To avoid conversion of laser frequency noise into amplitude noise by the cavity, we choose the rf modulation frequency to match the cavity's free spectral range. In this way small frequency fluctuations produce no additional noise, and a pure FM dispersion signal is recovered in transmission. We present a systematic study of the detection sensitivity, signal line shape and size, and slope at the central tuning. Experimentally, using a weakly absorbing gas such as C2H2 or C2HD placed inside an external high-finesse resonator, we obtained an integrated absorption sensitivity of 5 x 10(-13) (1 X 10(-14)/cm) for the gas's weak near-IR molecular overtone transitions. As an interesting application, a Nd:YAG laser was well stabilized on the P(5) line of the C2HD (nu(2) + 3 nu(3)) band by this technique. The high attainable sensitivity permitted selection of slow molecules with low power and gas pressure to give a linewidth 13 times below the room-temperature transit-time limit. [S0740-3224(99)01711-7]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. E China Normal Univ, Lab Quantum Opt, Shanghai 200062, Peoples R China. RP Ma, LS (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011 NR 33 TC 101 Z9 104 U1 4 U2 25 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 1999 VL 16 IS 12 BP 2255 EP 2268 DI 10.1364/JOSAB.16.002255 PG 14 WC Optics SC Optics GA 262JT UT WOS:000084064300012 ER PT J AU Renner, MS Ewing, R Bossart, GD Harris, D AF Renner, MS Ewing, R Bossart, GD Harris, D TI Sublingual squamous cell carcinoma in an Atlantic bottlenose dolphin (Tursiops truncatus) SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE bottlenose dolphin; Tursiops truncatus; neoplasia; squamous cell carcinoma; sublingual; oral cavity ID CETACEANS AB A 22-yr-old captive-born Atlantic bottlenose dolphin (Tursiops truncatus) presented with a nonhealing sublingual mucosal ulcer that was diagnosed histologically as a squamous cell carcinoma, the first such report in a dolphin. The lesion was excised completely and has not recurred. C1 Sea World Ohio, Aurora, OH 44202 USA. Univ Miami, Sch Med, Dept Pathol, Div Comparat Pathol, Miami, FL 33101 USA. Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Exot Anim Hosp, Coral Gables, FL 33129 USA. RP Renner, MS (reprint author), Sea World Ohio, 1100 Sea World Dr, Aurora, OH 44202 USA. NR 12 TC 5 Z9 6 U1 0 U2 3 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD DEC PY 1999 VL 30 IS 4 BP 573 EP 576 PG 4 WC Veterinary Sciences SC Veterinary Sciences GA 292BK UT WOS:000085774100018 PM 10749448 ER PT J AU Miller, MW Hay, ME Miller, SL Malone, D Sotka, EE Szmant, AM AF Miller, MW Hay, ME Miller, SL Malone, D Sotka, EE Szmant, AM TI Effects of nutrients versus herbivores on reef algae: A new method for manipulating nutrients on coral reefs SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MACROALGA DICTYOSPHAERIA-CAVERNOSA; DIADEMA-ANTILLARUM PHILIPPI; GREAT-BARRIER-REEF; FLORIDA-KEYS; COMMUNITY STRUCTURE; GROWTH; WATER; NITROGEN; EUTROPHICATION; PATTERNS AB There has been much discussion and some controversy regarding the role of nutrient enrichment versus other factors, such as altered rates of herbivory, in the degradation of coral reef ecosystems. The resolution of this controversy has been hampered by the lack of manipulative field studies testing the effects of ecologically relevant levels of nutrient enrichment on coral reef communities. We present a new method for adding ecologically relevant levels of nutrients to experimental substrates on coral reefs. The method elevates nutrients for sustained periods of time (>41 d without replenishment of nutrients) and allows for testing interactions of nutrients and altered levels of herbivory. Results from an offshore reef in Key Large, Florida, show strong effects of excluding large herbivorous fishes, negligible effects of nutrient enrichment-or effects that are opposite of predictions, and no interaction between nutrient levels and herbivory in affecting algal abundance. Patterns observed for this reef did not confirm predictions of previously proposed models that frondose macroalgal or crustose algal abundance would be enhanced with nutrient enrichment or that dominance of filamentous turfs would be greater in unenriched Conditions. In contrast to previous predictions, the abundance of larger macroalgae at this site was not increased by elevating nutrients above predicted threshold response levels of 1.0 mu M for total inorganic nitrogen or 0.10 mu M for soluble reactive phosphate. Also conflicting with some models, filamentous, nitrogen-fixing cyanobacteria were enhanced, rather than suppressed, by nutrient enrichment. C1 Georgia Inst Technol, Sch Biol, Atlanta, GA 30332 USA. SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Miami, FL 33149 USA. Univ Miami, Cooperat Inst Marine & Atmospher Sci, Miami, FL 33149 USA. Univ N Carolina, Natl Undersea Res Ctr, Key Largo, FL 33037 USA. Univ N Carolina, Dept Biol, Beaufort, NC 28516 USA. Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, Miami, FL 33149 USA. RP Hay, ME (reprint author), Georgia Inst Technol, Sch Biol, Atlanta, GA 30332 USA. RI Hay, Mark/D-9752-2011 OI Hay, Mark/0000-0002-6130-9349 NR 63 TC 108 Z9 114 U1 4 U2 27 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 1999 VL 44 IS 8 BP 1847 EP 1861 PG 15 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 263LF UT WOS:000084125600001 ER PT J AU Miller, MW Sluka, RD AF Miller, MW Sluka, RD TI Patterns of seagrass and sediment nutrient distribution suggest anthropogenic enrichment in Laamu Atoll, Republic of Maldives SO MARINE POLLUTION BULLETIN LA English DT Article DE fisheries; Maldives; nutrients; organic enrichment; seagrass; sediments ID THALASSIA-TESTUDINUM; FLORIDA BAY; LIMITATION; PHOSPHORUS; NITROGEN; ESTUARY; USA AB Sampling of seagrass cover and sediment nutrients was undertaken in lagoonal habitats of Laamu Atoll (Republic of Maldives) adjacent to three traditional fishing villages (fishing the predominant economic activity for more than 30 yr), three other villages (not traditional landing sites), and four uninhabited islands to determine if chronic input of organic fishing waste from the traditional fishing villages could explain spatial distribution of seagrass cover, Results indicated significantly greater cover of seagrass at the traditional fishing village sites than the other two site groups. Analysis of dried sediments showed sediments at traditional fishing village sites were significantly enriched with phosphorus, though no significant difference in nitrogen was found between groups of sites, These results, together with studies showing that sediment nutrient pools can limit seagrass bed development, suggest that anthropogenic enrichment of lagoonal sediments by fishing waste over generational time scales may have caused substantial proliferation of seagrass beds. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Oceanog Soc Maldives, Male, Maldives. RP Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 75 Virginia Beach Dr, Miami, FL 33149 USA. EM margaret.w.miller@noaa.gov NR 22 TC 8 Z9 8 U1 0 U2 5 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 1999 VL 38 IS 12 BP 1152 EP 1156 DI 10.1016/S0025-326X(99)00147-2 PG 5 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 271HA UT WOS:000084587100023 ER PT J AU Myers, E AF Myers, E TI National Undersea Research Program (NURP) SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 NOAA, Natl Undersea Res Program, Silver Spring, MD 20910 USA. RP Myers, E (reprint author), NOAA, Natl Undersea Res Program, Silver Spring, MD 20910 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 1999 VL 33 IS 4 BP 83 EP 84 PG 2 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 290MU UT WOS:000085680700010 ER PT J AU Siewert, T AF Siewert, T TI The international standards system and NDT SO MATERIALS EVALUATION LA English DT Editorial Material C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Siewert, T (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, MC 853,325 Broadway, Boulder, CO 80303 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD DEC PY 1999 VL 57 IS 12 BP 1225 EP + PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 264NZ UT WOS:000084189500004 ER PT J AU Carpenter, DT Codner, JR Barmak, K Rickman, JM AF Carpenter, DT Codner, JR Barmak, K Rickman, JM TI Issues associated with the analysis and acquisition of thin-film grain size data SO MATERIALS LETTERS LA English DT Article DE grain size distribution; thin film; transmission electron microscopy (TEM) ID GROWTH AB Reliable quantification of microstructural parameters via microscopy is of primary importance for the optimization of materials properties, especially for thin films such as those used in microelectronics or magnetic storage applications. Thus, we present a grain-size analysis for an Al thin-film microstructure consisting of the order of 10(4) grains for the purpose of examining the predictions of various grain growth models. The microstructural information was acquired with a recently developed automated grain recognition methodology, and the relatively large population obtained here permits a meaningful comparison of tabulated grain-size distributions with those inherent in theoretical models. Finally, we consider the role of grain identification criteria in determining grain-size distributions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Carpenter, DT (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. RI Barmak, Katayun/A-9804-2008 OI Barmak, Katayun/0000-0003-0070-158X NR 21 TC 30 Z9 30 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD DEC PY 1999 VL 41 IS 6 BP 296 EP 302 DI 10.1016/S0167-577X(99)00146-9 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 306RM UT WOS:000086610000006 ER PT J AU Williamson, JF Coursey, BM DeWerd, LA Hanson, WF Nath, R Rivard, RJ Ibbott, G AF Williamson, JF Coursey, BM DeWerd, LA Hanson, WF Nath, R Rivard, RJ Ibbott, G TI On the use of apparent activity (A(app)) for treatment planning of I-125 and Pd-103 interstitial brachytherapy sources: Recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee Subcommittee on Low-Energy Brachytherapy Source Dosimetry SO MEDICAL PHYSICS LA English DT Article C1 Washington Univ, Radiat Oncol Ctr, St Louis, MO 63110 USA. NIST, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. Univ Wisconsin, Accredited Dosimetry & Calibrat Lab, Madison, WI 53706 USA. MD Anderson Canc Ctr, Radiol Phys Ctr, Houston, TX 77030 USA. Yale Univ, Dept Therapeut Radiol, New Haven, CT 06510 USA. New England Med Ctr, Dept Radiat Oncol, Boston, MA 02111 USA. Univ Kentucky, Dept Radiat Med, Lexington, KY 40536 USA. RP Coursey, BM (reprint author), Washington Univ, Radiat Oncol Ctr, St Louis, MO 63110 USA. NR 9 TC 25 Z9 28 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD DEC PY 1999 VL 26 IS 12 BP 2529 EP 2530 DI 10.1118/1.598789 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 267LJ UT WOS:000084359200004 PM 10619235 ER PT J AU Rosel, PE France, SC Wang, JY Kocher, TD AF Rosel, PE France, SC Wang, JY Kocher, TD TI Genetic structure of harbour porpoise Phocoena phocoena populations in the northwest Atlantic based on mitochondrial and nuclear markers SO MOLECULAR ECOLOGY LA English DT Article DE bycatch; control region; management; microsatellite; stocks ID WHALE DELPHINAPTERUS-LEUCAS; ALLELE FREQUENCIES; CONTROL REGION; DANISH WATERS; BALTIC SEA; DNA; MICROSATELLITE; SEQUENCE; CONSERVATION; IDENTIFICATION AB The harbour porpoise, Phocoena phocoena, experiences high levels of nonnatural mortality owing to interactions with commercial fisheries throughout its range. To accurately evaluate the significance of this bycatch, information on population structure is required. We have examined the population structure of this species in the northwest Atlantic Ocean using mitochondrial DNA (mtDNA) sequence and nuclear microsatellite data. Samples from four previously proposed summer breeding populations-the Gulf of Maine, eastern Newfoundland, the Gulf of St Lawrence and West Greenland-were analysed. Control-region sequences revealed a significant partitioning of genetic variation among most of these summer populations, indicating that northwest Atlantic harbour porpoises should not be considered one panmictic population. Analysis of females alone yielded the highest levels of population subdivision, suggesting that females are more philopatric than males. At least three management units may be defined for harbour porpoises in the northwest Atlantic based on these data. Analysis of six microsatellite loci failed to detect significant population subdivision. Male-mediated gene flow may maintain homogeneity among nuclear loci, while female philopatry is sufficient to produce a signal of population subdivision in the maternally inherited mtDNA genome, mtDNA analyses also indicate that winter aggregations of harbour porpoises along the US mid-Atlantic states comprise animals from more than one summer breeding population. C1 Univ New Hampshire, Dept Zool, Durham, NH 03824 USA. Coll Charleston, Dept Biol, Charleston, SC 29424 USA. McMaster Univ, Dept Biol, Hamilton, ON L8S 4K1, Canada. RP Rosel, PE (reprint author), Natl Ocean Serv, 219 Ft Johnson Rd, Charleston, SC 29412 USA. RI Kocher, Thomas/B-3089-2013 NR 58 TC 76 Z9 83 U1 0 U2 16 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 DEC PY 1999 VL 8 IS 12 SU 1 BP S41 EP S54 DI 10.1046/j.1365-294X.1999.00758.x PG 14 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 291MB UT WOS:000085737800006 PM 10703550 ER PT J AU Taylor, BL Dizon, AE AF Taylor, BL Dizon, AE TI First policy then science: why a management unit based solely on genetic criteria cannot work SO MOLECULAR ECOLOGY LA English DT Article DE conservation; dispersal; genetic variation; management unit; population structure; statistical power ID POPULATION-STRUCTURE; STATISTICAL POWER; CONSERVATION; FLOW AB In contrast to the goals of the symposium from which this series of papers originated, we argue that attempts to apply unambiguously defined and general management unit criteria based solely on genetic parameters can easily lead to incorrect management decisions. We maintain that conservation genetics is best served by altering the perspective of data analysis so that decision making is optimally facilitated. To do so requires accounting for policy objectives early in the design and execution of the science. This contrasts with typical hypothesis testing approaches to analysing genetic data for determining population structure, which often aspire to objectivity by considering management objectives only after the analysis is complete. The null hypothesis is generally taken as panmixia with a strong predilection towards avoiding false acceptance of the alternative hypothesis (the existence of population structure). We show by example how defining management units using genetic data and standard scientific analyses that do not consider either the specific management objectives or the anthropogenic risks facing the populations being studied can easily result in a management failure by losing local populations. We then use the same example to show how an 'applied' approach driven by specific objectives and knowledge of abundance and mortality results in appropriate analyses and better decisions. Because management objectives stem from public policy, which differs among countries and among species groups, criteria for defining management units must be specific, not general. Therefore, we conclude that the most productive way to define management units is on a case-by-ease basis. We also suggest that creating analytical tools designed specifically to address decision making in a management context, rather than re-tooling academic tools designed for other purposes, will increase and improve the use of genetics in conservation. C1 SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Taylor, BL (reprint author), SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 12 TC 74 Z9 77 U1 0 U2 18 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 DEC PY 1999 VL 8 IS 12 SU 1 BP S11 EP S16 DI 10.1046/j.1365-294X.1999.00797.x PG 6 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 291MB UT WOS:000085737800003 PM 10703548 ER PT J AU Schultz, DM Schumacher, PN AF Schultz, DM Schumacher, PN TI The use and misuse of conditional symmetric instability SO MONTHLY WEATHER REVIEW LA English DT Review ID POTENTIAL VORTICITY ANOMALIES; MESOSCALE CONVECTIVE SYSTEMS; NUMERICAL WEATHER PREDICTION; BETA-SCALE CIRCULATIONS; SLANTWISE CONVECTION; FRONTAL RAINBANDS; INERTIAL INSTABILITY; PRECIPITATION BANDS; UNITED-STATES; POSITIVE CAPE AB A commonly employed explanation for single- and multiple-banded clouds and precipitation in the extratropics is slantwise convection due to the release of moist symmetric instability (MSI), of which one type is conditional symmetric instability (CSI). This article presents a review of CSI with the intent of synthesizing the results from previous observational, theoretical, and modeling studies. This review contends that CSI as a diagnostic tool to assess slantwise convection has been, and continues to be, misused and overused. Drawing parallels to an ingredients-based methodology for forecasting deep, moist convection that requires the simultaneous presence of instability, moisture, and lift, some of the misapplications of CSI can be clarified. Many of these pitfalls have been noted by earlier' authors, but are, nevertheless, often understated, misinterpreted, or neglected by later researchers and forecasters. Topics include the evaluation of the potential for slantwise convection, the relationship between frontogenesis and MSI, the coexistence of moist gravitational instability and MSI, the nature of banding associated with slantwise convection, and the diagnosis of slantwise convection using mesoscale numerical models. The review concludes with suggested directions for future observational, theoretical, and diagnostic investigation. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. NOAA, Natl Weather Serv, Sioux Falls, SD USA. RP NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM schultz@nssl.noaa.gov RI Schultz, David M./A-3091-2010 OI Schultz, David M./0000-0003-1558-6975 NR 169 TC 113 Z9 128 U1 0 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1999 VL 127 IS 12 BP 2709 EP 2732 DI 10.1175/1520-0493(1999)127<2709:TUAMOC>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 263VJ UT WOS:000084145700001 ER PT J AU Anderson, JL Anderson, SL AF Anderson, JL Anderson, SL TI A Monte Carlo implementation of the nonlinear filtering problem to produce ensemble assimilations and forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID QUASI-GEOSTROPHIC MODEL; INITIAL CONDITIONS; PREDICTION SYSTEM; SKILL; PERTURBATIONS; EQUILIBRIUM; SELECTION; IMPACT; ERROR; NMC AB Knowledge of the probability distribution of initial conditions is central to almost all practical studies of predictability and to improvements in stochastic prediction of the atmosphere. Traditionally, data assimilation for atmospheric predictability or prediction experiments has attempted to find a single "best" estimate of the initial state. Additional information about the initial condition probability distribution is then obtained primarily through heuristic techniques that attempt to generate representative perturbations around the best estimate. However, a classical theory for generating an estimate of the complete probability distribution of an initial state given a set of observations exists. This nonlinear filtering theory can be applied to unify the data assimilation and ensemble generation problem and to produce superior estimates of the probability distribution of the initial state of the atmosphere (or ocean) on regional or global scales. A Monte Carlo implementation of the fully nonlinear filter has been developed and applied to several low-order models. The method is able to produce assimilations with small ensemble mean errors while also providing random samples of the initial condition probability distribution. The Monte Carlo method can be applied in models that traditionally require the application of initialization techniques without any explicit initialization. Initial application to larger models is promising, but a number of challenges remain before the method can be extended to large realistic forecast models. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Metron Inc, Reston, VA USA. RP Anderson, JL (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 46 TC 396 Z9 412 U1 3 U2 21 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 DEC PY 1999 VL 127 IS 12 BP 2741 EP 2758 DI 10.1175/1520-0493(1999)127<2741:AMCIOT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 263VJ UT WOS:000084145700003 ER PT J AU Mo, KC AF Mo, KC TI Alternating wet and dry episodes over California and intraseasonal oscillations SO MONTHLY WEATHER REVIEW LA English DT Article ID OUTGOING LONGWAVE RADIATION; NORTHERN WINTER; TROPICAL CONVECTION; PRECIPITATION; HEMISPHERE AB The NCEP-NCAR reanalysis together with the outgoing longwave radiation anomalies (OLRAs) and a gridded daily precipitation over the United States were used to analyze precipitation over California on intraseasonal timescales. The intraseasonal (10-90 days) filtered OLRAs were subjected to singular spectrum analysis, which identifies nonlinear oscillations in noisy time series. There are two dominant oscillatory modes associated with California rainfall with periods near 36-40 and 20-25 days. The 36-40-day mode is related to the Madden-Julian Oscillation (MJO) in the Tropics. Enhanced tropical convection propagates from the western Pacific to the central Pacific. A three-cell pattern with negative OLRAs in California and positive anomalies in the eastern Pacific and the Pacific Northwest starts to develop 4 days later and rainfall starts in California. Anomalies associated with the 20-25-day mode are responsible for alternating wet and dry episodes over California with periods shorter than the timescales of the MJO. The 20-25-day mode is the leading mode in the 7-30-day band and is related to tropical convection in the Pacific. In the extratropics, cloud bands propagate northward along the west coast of North America from the eastern Pacific just north of the ITCZ through California to the Pacific Northwest. The 200-hPa streamfunction anomaly composites associated with the 20-25-day mode reveal a westward propagating wave train dominated by a zonal wavenumber 2. This mode has a spatial structure similar to the traveling pattern described by Branstator. C1 NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 USA. RP Mo, KC (reprint author), NOAA, NWS, NCEP, Climate Predict Ctr, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 26 TC 26 Z9 27 U1 1 U2 5 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 DEC PY 1999 VL 127 IS 12 BP 2759 EP 2776 DI 10.1175/1520-0493(1999)127<2759:AWADEO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 263VJ UT WOS:000084145700004 ER PT J AU Fu, J Tsai, V Koning, R Dixson, R Vorburger, T AF Fu, J Tsai, V Koning, R Dixson, R Vorburger, T TI Algorithms for calculating single-atom step heights SO NANOTECHNOLOGY LA English DT Article ID FORCE MICROSCOPY; SI(111) AB Recently, our work on the measurement of Si(lll)single atomic steps has prompted us to investigate the algorithm for the calculation of a one-sided step height. We compared the results of a two-point subtraction and a histogram technique under different conditions of surface tilt with respect to the measuring frame. By evaluating a simulated Si(lll)atomic step, we found its calculated height could deviate from the true value as high as 2% due to a misalignment of the measuring axis and sample axis of 0.1 degrees. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Fu, J (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 6 TC 23 Z9 23 U1 2 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC PY 1999 VL 10 IS 4 BP 428 EP 433 DI 10.1088/0957-4484/10/4/312 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 267CR UT WOS:000084337900012 ER PT J AU Denecke, B Eykens, R Pauwels, J Robouch, P Gilliam, DM Hodge, P Hutchinson, JMR Nico, JS AF Denecke, B Eykens, R Pauwels, J Robouch, P Gilliam, DM Hodge, P Hutchinson, JMR Nico, JS TI Characterization of actinide targets by low solid-angle alpha particle counting SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th World Conference of the International-Nuclear-Target-Development-Society CY OCT 05-09, 1998 CL OAK RIDGE, TENNESSEE SP Int Nucl Target Dev Soc DE actinide; alpha analysis; characterization of target; uranium; uniformity of target AB Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine (UF4)-U-233 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties' for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi proportional gas counter results were about 0.75% higher than those of the defined solid-angle methods. A re-examination of the correction for scattering from the polished silicon wafer substrates was undertaken to explain this discrepancy. Preliminary results of the recalculated 2 pi proportional gas counter results are also given. (C) 1999 Elsevier Science B.V. All rights reserved. C1 NIST, Gaithersburg, MD 20899 USA. Commiss European Communities, Joint Res Ctr, IRMM, B-2440 Geel, Belgium. RP Gilliam, DM (reprint author), NIST, React A-106, Gaithersburg, MD 20899 USA. NR 6 TC 8 Z9 8 U1 0 U2 0 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 DEC 1 PY 1999 VL 438 IS 1 BP 124 EP 130 DI 10.1016/S0168-9002(99)00669-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 261QP UT WOS:000084020300024 ER PT J AU Steele, KE AF Steele, KE TI Ocean wave heave time series as the sum of nonharmonic sinusoids SO OCEAN ENGINEERING LA English DT Article DE ocean; wave; wavelets; leakage; stationarity AB A discrete wave displacement time-series record is usually analyzed by a Discrete Fourier Transform (DFT), which represents the record as the sum of a finite number of harmonic sinusoids. When the dominant sinusoid of the record is not one of these harmonics, DFT "leakage" produces a distorted picture of the dominant wave, particularly for records not much longer than the largest period in the record. This paper proposes a non-Fourier method for determining the dominant wave period that is applicable even when the record is short relative to the largest period present in the record. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. RP Steele, KE (reprint author), Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 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 DEC PY 1999 VL 26 IS 12 BP 1335 EP 1357 DI 10.1016/S0029-8018(98)00072-9 PG 23 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 221WN UT WOS:000081750300005 ER PT J AU Earle, MD Steele, KE Wang, DWC AF Earle, MD Steele, KE Wang, DWC TI Use of advanced directional wave spectra analysis methods SO OCEAN ENGINEERING LA English DT Article DE buoys; wave data; wave spectra ID PITCH AB Frequency-dependent cross-spectral parameters for pitch-roll buoy data and parameters that describe directional wave spectra based on a directional Fourier series are developed by the National Data Buoy Center (NDBC) and other organizations that collect wave data. The World Meteorological Organization (WMO) specifies wave data product formats in its Wave Observation (FM 65 WAVEOB) code. Other organizations, such as the US Army Corps of Engineers Field Wave Caging Program (FWGP), have similar specifications. A directional Fourier series has poor directional resolution compared with advanced methods such as those based on maximum likelihood and maximum entropy. Transformations are developed for applying the advanced methods and working with directional wave information stored in the WMO's FM 65 WAVEOB code, the FWGP's Wave Data Analysis Standard (WDAS) format, and similar codes and formats. Using the transformations, a directional Fourier series expansion method, a Maximum Likelihood Method (MLM), and a Maximum Entropy Method (MEM) are each applied to 115 sets of NDBC directional wave data. The MEM and MLM provide better directional resolution, but the MEM produces artificial double peaks, There are considerable differences for the three used methods. The developed transformation equations enable wave data users to apply the method that best suits their applications. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Neptune Sci Inc, Reston, VA 20191 USA. Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. RP Earle, MD (reprint author), Neptune Sci Inc, 12310 Pinecrest Rd,Suite 203, Reston, VA 20191 USA. NR 11 TC 14 Z9 14 U1 1 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 DEC PY 1999 VL 26 IS 12 BP 1421 EP 1434 DI 10.1016/S0029-8018(99)00010-4 PG 14 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 221WN UT WOS:000081750300008 ER PT J AU Liu, AS AF Liu, AS TI Comment on "Intersubband optical absorption in two-level quantum wells embedded in a planar microcavity" SO OPTICAL AND QUANTUM ELECTRONICS LA English DT Editorial Material C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Liu, AS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 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 1999 VL 31 IS 12 BP 1277 EP 1278 DI 10.1023/A:1006904315504 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA 268DA UT WOS:000084398000008 ER PT J AU Hsieh, ML Paek, EG Wilson, CL Hsu, KY AF Hsieh, ML Paek, EG Wilson, CL Hsu, KY TI Performance enhancement of a joint transform correlator using the directionality of a spatial light modulator SO OPTICAL ENGINEERING LA English DT Article DE optical pattern recognition; spatial light modulators; optical information processing; joint transform correlator; optical security AB We observe that conventional electrically addressable spatial light modulators have different transfer functions along the fast (horizontal) and the slow (vertical) directions. We then propose to use the directionality of a spatial light modulator to increase the performance of a joint transform correlator. Our experimental results show that input space-bandwidth product of a joint transform correlator can be significantly increased by recording a hologram so that interference fringes run along the fast (horizontal) direction of a spatial light modulator. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)00412-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Chiao Tung Univ, Inst Electroopt Engn, Hsinchu, Taiwan. Natl Chiao Tung Univ, Inst Electroopt Engn, Hsinchu, Taiwan. RP Hsieh, ML (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Hsu, Ken/C-8645-2012 NR 5 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD DEC PY 1999 VL 38 IS 12 BP 2118 EP 2121 DI 10.1117/1.602320 PG 4 WC Optics SC Optics GA 264FN UT WOS:000084170100022 ER PT J AU Griesmann, U Burnett, JH AF Griesmann, U Burnett, JH TI Refractivity of nitrogen gas in the vacuum ultraviolet SO OPTICS LETTERS LA English DT Article AB We have measured the refractivity of nitrogen gas in the ultraviolet and the vacuum ultraviolet, using a Fourier-transform spectrometer. A new two-term Sellmeier formula for the standard refractivity between 145 and 270 nm is derived. (C) 1999 Optical Society of America. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02139 USA. RP Griesmann, U (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 9 TC 20 Z9 22 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 1 PY 1999 VL 24 IS 23 BP 1699 EP 1701 DI 10.1364/OL.24.001699 PG 3 WC Optics SC Optics GA 260PW UT WOS:000083959900015 PM 18079907 ER PT J AU Diddams, SA Ma, LS Ye, J Hall, JL AF Diddams, SA Ma, LS Ye, J Hall, JL TI Broadband optical frequency comb generation with a phase-modulated parametric oscillator SO OPTICS LETTERS LA English DT Article ID DISPERSION AB We introduce a novel broadband optical frequency comb generator consisting of a parametric oscillator with an intracavity electro-optic phase modulator. The parametric oscillator is pumped by 532-nm light and produces near-degenerate signal and idler fields. The modulator generates a comb structure about both the signal and the idler. Coupling between the two families of modes results in a dispersion-limited comb that spans 20 nm (5.3 THz). A signal-to-noise ratio of >30 dB in a 300-kHz bandwidth is observed in the beat frequency between individual comb elements and a reference laser. (C) 1999 Optical Society of America. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Diddams, SA (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011; Diddams, Scott/L-2819-2013 NR 10 TC 39 Z9 39 U1 1 U2 7 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 DEC 1 PY 1999 VL 24 IS 23 BP 1747 EP 1749 DI 10.1364/OL.24.001747 PG 3 WC Optics SC Optics GA 260PW UT WOS:000083959900031 PM 18079922 ER PT J AU Broecker, WS Clark, E McCorkle, DC Peng, TH Hajdas, I Bonani, G AF Broecker, WS Clark, E McCorkle, DC Peng, TH Hajdas, I Bonani, G TI Evidence for a reduction in the carbonate ion content of the deep sea during the course of the Holocene SO PALEOCEANOGRAPHY LA English DT Article ID PRESERVATION AB The paleo carbonate ion proxy proposed by Broecker et al. [1999] is applied in a search for trends in the Holocene acidity of waters in the transition zone between North Atlantic Deep Water and Antarctic Bottom Water (AABW). A clear signal emerges that the carbonate ion content of waters in this zone declined during the past 8000 years. In order to determine whether this decline represents a strengthening of the northward penetrating tongue of low CO3= content AABW or a global reduction of CO3= measurements were made on a core from the Ontong Java Plateau in the western equatorial Pacific. Evidence for a similar decline in CO3= ion over the course of the Holocene was obtained lending support of the latter explanation. Such a drop is consistent with the recent finding by Indermuhle et al. [1999] that the CO2 content of the atmosphere (as recorded in the Taylor Dome Antarctica ice core) rose by 20-25 ppm during the past 8000 years. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. ETH Honggerberg, Inst Theoret Phys, CH-8093 Zurich, Switzerland. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Broecker, WS (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RI Hajdas, Irka/C-6696-2011 NR 9 TC 59 Z9 60 U1 2 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD DEC PY 1999 VL 14 IS 6 BP 744 EP 752 DI 10.1029/1999PA900038 PG 9 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA 265WC UT WOS:000084268100008 ER PT J AU Burke, JP Greene, CH Bohn, JL Wang, H Gould, PL Stwalley, WC AF Burke, JP Greene, CH Bohn, JL Wang, H Gould, PL Stwalley, WC TI Determination of K-39 scattering lengths using photoassociation spectroscopy of the 0(g)(-) state SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; QUANTUM DEFECT ANALYSIS; LONG-RANGE DISPERSION; 2 K ATOMS; COLD COLLISIONS; EXCHANGE INTERACTIONS; MAGNETIC-FIELD; GROUND-STATE; COOLED ATOMS; RESONANCE AB Threshold scattering properties of K-39 atoms are extracted from a line-shape analysis of photoassociation data. Specifically, we consider the rovibrational levels (upsilon'=0-6) populated in the photoassociation process K(4S) + K(4S)+ h p omega-->K-2*[0(g)(-)(upsilon',J')]. The measured spectra exhibit several general trends, including large J' = 2 linewidths, large relative J' =4 peak intensities, and odd rotational lines which are weak or missing. The even J' features signal the presence of a d-wave shape resonance in the ground-state collisions. The combination of spectral features allows us to place the following limits on the ground-state singlet and triplet scattering lengths, a(s) = 140(-9)(+6) a.u. and a(t)= - 17-0.045(C-6- (C) over bar(6))+/-25 a.u., (C) over bar(6)= 3800 a.u. [S1050-2947(99)03512-X]. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Burke, JP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 52 TC 25 Z9 25 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1999 VL 60 IS 6 BP 4417 EP 4426 DI 10.1103/PhysRevA.60.4417 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 263WJ UT WOS:000084148000034 ER PT J AU Williams, CJ Tiesinga, E Julienne, PS Wang, H Stwalley, WC Gould, PL AF Williams, CJ Tiesinga, E Julienne, PS Wang, H Stwalley, WC Gould, PL TI Determination of the scattering lengths of K-39 from 1(u) photoassociation line shapes SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; ALKALI-METAL DIMER; RADIATIVE LIFETIME; ATOMIC-COLLISIONS; RELAXATION RATES; RB-87 ATOMS; SPECTROSCOPY; STATE; MOLECULES AB We report threshold scattering properties for K-39(f = 1) atoms obtained from analysis of experimental photoassociation spectra of the purely long-range K-39(2) lit state. The existence of hyperfine structure in the excited K-2, 1(u) state and a knowledge of the Hamiltonian structure for two colliding ground state alkali atoms enables us to obtain information on the sign and magnitudes of certain scattering lengths for ground state collisions. Analysis of the experimental photoassociation line shapes shows that the 39K scattering lengths are between -3.2 and +0.8 nm (-60a(0) and +15a(0), where 1a(0) = 1 a.u. = 0.0529177 nm) for the a (3)Sigma(u)(+) molecular state, between +4.8 and +12 nm (+90a(0) and +230a(0)) for the X(1)Sigma(g)(+) state, and between -7.9 and +1.1 nm (-150a(0) and +20a(0)) for collisions of two f = 1, m = -1 atoms. [S1050-2947(99)03612-4]. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Univ Connecticut, Storrs, CT 06269 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. RP Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 41 TC 31 Z9 32 U1 0 U2 2 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 1999 VL 60 IS 6 BP 4427 EP 4438 DI 10.1103/PhysRevA.60.4427 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 263WJ UT WOS:000084148000035 ER PT J AU Venturi, V Whittingham, IB Leo, PJ Peach, G AF Venturi, V Whittingham, IB Leo, PJ Peach, G TI Close-coupled calculation of collisions of magnetostatically trapped metastable helium atoms SO PHYSICAL REVIEW A LA English DT Article ID POLARIZED TRIPLET HELIUM; ASSOCIATIVE IONIZATION; ULTRACOLD COLLISIONS; RESONANT LIGHT; COLD; FIELDS; STATE; GAS; CONDENSATION; SUPPRESSION AB A quantum-mechanical close-coupled calculation for collisions of spin-polarized triplet helium atoms in a magnetostatic trap is presented in which the Penning and associative ionization processes are represented by a complex optical potential. The rate coefficients for the spin relaxation and relaxation-induced Penning ionization processes for a range of magnetic fields and temperatures, spanning the cold and ultracold temperature regimes, have been calculated and the sensitivity of these results to uncertainties in the molecular potentials and autoionization width investigated. The rate constants for both elastic and inelastic processes were found to be particularly sensitive to the short-range (5)Sigma(g)(+) molecular potential and, to a lesser extent, the rate constants for relaxation-induced Penning ionization displayed sensitivity to the short-range form of the (1)Sigma(g)(+) molecular a potential and the autoionization width. [S1050-2947(99)07012-2]. C1 James Cook Univ N Queensland, Sch Comp Sci Math & Phys, Townsville, Qld 4811, Australia. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Univ London Univ Coll, Dept Phys & Astron, London WC1E 6BT, England. RP Venturi, V (reprint author), James Cook Univ N Queensland, Sch Comp Sci Math & Phys, Townsville, Qld 4811, Australia. RI Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 50 TC 39 Z9 39 U1 2 U2 10 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 1999 VL 60 IS 6 BP 4635 EP 4646 DI 10.1103/PhysRevA.60.4635 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 263WJ UT WOS:000084148000057 ER PT J AU LeBrun, T Southworth, SH Armen, GB MacDonald, MA Azuma, Y AF LeBrun, T Southworth, SH Armen, GB MacDonald, MA Azuma, Y TI Radiationless resonant Raman scattering at the Ar K edge SO PHYSICAL REVIEW A LA English DT Article ID INNER-SHELL PHOTOIONIZATION; POST-COLLISION INTERACTION; SYNCHROTRON RADIATION; POSTCOLLISION-INTERACTION; QUANTUM-THEORY; ARGON; ELECTRON; THRESHOLD; SPECTRA; FLUORESCENCE AB Partial cross sections for Ar K-L2L3(D-1(2))np, n=4 and 5 spectator Auger states excited by x-ray absorption across the K edge, were measured and compared with calculations based on the theory of radiationless resonant Raman scattering. Core relaxation and coherence among bound and continuum intermediate states produce shake-up, shake-down, and photoelectron-recapture effects in the cross sections. The width and position of the 4p spectator Auger peak are shown to be sensitive to resonance structure in the partial cross section via averaging over the x-ray bandwidth. [S1050-2947(99)09712-7]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Tennessee, Knoxville, TN 37996 USA. SERC, Daresbury Lab, CLRC, Warrington WA4 4AD, Cheshire, England. KEK, IMSS, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 25 TC 23 Z9 23 U1 0 U2 4 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 1999 VL 60 IS 6 BP 4667 EP 4672 DI 10.1103/PhysRevA.60.4667 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 263WJ UT WOS:000084148000059 ER PT J AU Ravel, B Cockayne, E Newville, M Rabe, KM AF Ravel, B Cockayne, E Newville, M Rabe, KM TI Combined EXAFS and first-principles theory study of Pb1-xGexTe SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION-FINE-STRUCTURE; FERROELECTRIC TRANSITION; AMPLITUDE; SPECTRA; PB AB The narrow band-gap semiconductor Pb1-xGexTe has a low-temperature ferroelectric rhombohedral phase whose average structure is a distorted rocksalt structure. We have measured the extended x-ray-absorption-fine-structure (EXAFS) spectra of Pb1-xGexTe with x approximate to 0.3 at the Ge and Te K edges and at the Pb L-III edge. Guided by first-principles calculations, we create a model for the local structure as a distortion from the ideal rocksalt structure. By corefining the spectra from these three edges, we demonstrate that the data are consistent with our fitting model and we directly measure several secondary structural distortions predicted by the theory. This work demonstrates a powerful approach to the determination of local structures in complex materials by using first-principles calculations in conjunction with EXAFS measurements. [S0163-1829(99)13041-8]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Yale Univ, Dept Appl Phys, New Haven, CT 06520 USA. RP Ravel, B (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 22 TC 26 Z9 26 U1 2 U2 12 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 1999 VL 60 IS 21 BP 14632 EP 14642 DI 10.1103/PhysRevB.60.14632 PG 11 WC Physics, Condensed Matter SC Physics GA 263TQ UT WOS:000084141700041 ER PT J AU Hyman, RA Zangwill, A Stiles, MD AF Hyman, RA Zangwill, A Stiles, MD TI Magnetic reversal of ultrathin films with planar magnetization SO PHYSICAL REVIEW B LA English DT Article ID ANISOTROPIES; SURFACES; KERR AB Classical spin simulations are used to study magnetic reversal in ultrathin (1-6 monolayers) Alms with planar magnetization and surface roughness typical of epitaxially grown samples. Reduced site symmetry at surface steps leads to strong, local anisotropies that both nucleate reversal and pin domain wall motion. The results we obtain from realistic models with periodic roughness are interpreted using a much simpler model with a single, finite-length step. These models show how growth induced roughness can lead to oscillations in the coercive field as the film thickness is increased, as seen in some experiments. They also demonstrate explicitly how local step anisotropies become less important and magnetostatic interactions become more important as the film thickness increases. [S0163-1829(99)00946-7]. C1 Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Natl Inst Stand & Technol, Electron Phys Grp, Gaithersburg, MD 20899 USA. RP Hyman, RA (reprint author), Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 20 TC 7 Z9 7 U1 0 U2 4 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 1999 VL 60 IS 21 BP 14830 EP 14836 DI 10.1103/PhysRevB.60.14830 PG 7 WC Physics, Condensed Matter SC Physics GA 263TQ UT WOS:000084141700064 ER PT J AU Bateman, FB Haight, RC Chadwick, MB Sterbenz, SM Grimes, SM Vonach, H AF Bateman, FB Haight, RC Chadwick, MB Sterbenz, SM Grimes, SM Vonach, H TI Light charged-particle production from neutron bombardment of silicon up to 60 MeV: Role of level densities and isospin SO PHYSICAL REVIEW C LA English DT Article ID SI-29 AB Inclusive light charged-particle emission spectra and cross sections from neutron bombardment of silicon were measured at 30 degrees 60 degrees, 90 degrees, and 135 degrees over the neutron energy range from threshold to approximately 60 MeV. Source neutrons, continuous in energy, were provided by the spallation neutron source of the Los Alamos Weapons Neutron Research facility. Comparisons of our alpha-particle data with Hauser-Feshbach calculations, which include multistage emission processes and preequilibrium particle emission, indicate that the majority of alpha particles result from compound nuclear reactions. For proton and deuteron emission, direct and preequilibrium processes contribute significantly to the emission cross section. These data provide rigorous tests for the calculations while helping to guide the selection of input parameters such as nuclear level densities. The effects of assuming partial or complete isospin conservation are shown to be important for these reactions. [S0556-2813(99)02012-9]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ohio Univ, Athens, OH 45701 USA. Inst Radiumforsch & Kernphys, A-1090 Vienna, Austria. RP Bateman, FB (reprint author), NIST Radiat Interact & Dosimetry, 100 Bur Dr,Stop 8460, Gaithersburg, MD 20899 USA. NR 48 TC 33 Z9 33 U1 0 U2 2 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 DEC PY 1999 VL 60 IS 6 AR 064609 DI 10.1103/PhysRevC.60.064609 PG 14 WC Physics, Nuclear SC Physics GA 266RF UT WOS:000084313100045 ER PT J AU Starr, FW Sciortino, F Stanley, HE AF Starr, FW Sciortino, F Stanley, HE TI Dynamics of simulated water under pressure SO PHYSICAL REVIEW E LA English DT Article ID SINGULARITY-FREE INTERPRETATION; KINETIC GLASS-TRANSITION; LIQUID PHASE-TRANSITION; SUPERCOOLED WATER; MOLECULAR-DYNAMICS; BEHAVIOR; RELAXATION; POINT; MODEL; COMPRESSIBILITY AB We present molecular dynamics simulations of the extended simple-point-charge model of water to probe the dynamic properties at temperatures from 350 K down to 190 K and pressures from 2.5 GPa (25 kbar) down to -300 MPa (-3 kbar). We compare our results with those obtained experimentally, both of which show a diffusivity maximum as a function of pressure. We find that our simulation results are consistent with the predictions of the mode-coupling theory for the dynamics of weakly supercooled liquids-strongly supporting the hypothesis that the apparent divergences of dynamic properties observed experimentally may be independent of a possible thermodynamic singularity at low temperature. The dramatic change in water's dynamic and structural properties as a function of pressure allows us to confirm the predictions of MCT over a much broader range of the von Schweidler exponent values than has been studied for simple atomic liquids. We also show how structural changes are reflected in the wave-vector dependence of dynamic properties of the liquid along a path of nearly constant diffusivity. For temperatures below the crossover temperature of MCT (where the predictions of MCT are expected to fail), we find tentative evidence for a crossover of the temperature dependence of the diffusivity from power-law to Arrhenius behavior, with an activation energy typical of a strong liquid. [S1063-651X(99)11712-4]. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. Boston Univ, Ctr Computat Sci, Boston, MA 02215 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Univ La Sapienza, Dipartimento Fis, INFM, I-00185 Rome, Italy. RP Starr, FW (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Sciortino, Francesco/B-4768-2012; Starr, Francis/C-7703-2012 NR 73 TC 175 Z9 176 U1 1 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 DEC PY 1999 VL 60 IS 6 BP 6757 EP 6768 DI 10.1103/PhysRevE.60.6757 PN A PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 271NM UT WOS:000084600400068 PM 11970595 ER PT J AU Peko, BL Dyakov, IV Champion, RL Rao, MVVS Olthoff, JK AF Peko, BL Dyakov, IV Champion, RL Rao, MVVS Olthoff, JK TI Ion-molecule reactions and ion energies in a CF4 discharge SO PHYSICAL REVIEW E LA English DT Article ID CROSS-SECTIONS; REFERENCE CELL; HYBRID MODEL; PLASMA; DISTRIBUTIONS; COLLISIONS; H-3(+); TRANSPORT; HYDROGEN; ARGON AB Absolute cross sections have been measured for reactants typically found in carbon tetrafluoride (CF4) discharges for collision energies below a few hundred electron volts. The reactions investigated include collision-induced dissociation and dissociative electron transfer reactions for CF3+ and F+ colliding with CF4, and collisional electron detachment for F- colliding with CF4. Also presented are measurements of energies and relative intensities of ions generated in de Townsend CF4 discharges with E/N values ranging from 4 x 10(-18) V m(2) to 25 x 10(-18) V m(2) [4 to 25 kTd]. Ion energy and ion intensity data for the Townsend discharges are analyzed in light of the measured cross sections. [S1063-651X(99)05212-5]. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Peko, BL (reprint author), Univ Denver, Dept Phys, Denver, CO 80208 USA. NR 24 TC 20 Z9 20 U1 1 U2 3 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 1999 VL 60 IS 6 BP 7449 EP 7456 DI 10.1103/PhysRevE.60.7449 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 271NQ UT WOS:000084600700068 PM 11970693 ER PT J AU Wang, YC Van Brunt, RJ AF Wang, YC Van Brunt, RJ TI Response to "Comment on 'Calculation of electron transport in Ar-N-2 and He-Kr gas mixtures - implications for validity of Blanc's law method' " [Phys. Plasmas 6, 4794 (1999)] SO PHYSICS OF PLASMAS LA English DT Article C1 NIST, Gaithersburg, MD 20899 USA. RP Wang, YC (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 1999 VL 6 IS 12 BP 4797 EP 4797 DI 10.1063/1.873772 PG 1 WC Physics, Fluids & Plasmas SC Physics GA 255TH UT WOS:000083685900049 ER PT J AU Burnett, K Edwards, M Clark, CW AF Burnett, K Edwards, M Clark, CW TI The theory of Bose-Einstein codensation of dilute gases SO PHYSICS TODAY LA English DT Article ID COLLECTIVE EXCITATIONS; CONDENSATE; ATOMS; NUMBER; TRAP C1 Univ Oxford, Oxford, England. Georgia So Univ, Statesboro, GA 30460 USA. NIST, Gaithersburg Facil, Gaithersburg, MD USA. RP Burnett, K (reprint author), Univ Oxford, S Parks Rd, Oxford, England. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 28 TC 46 Z9 46 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD DEC PY 1999 VL 52 IS 12 BP 37 EP 42 DI 10.1063/1.882899 PG 6 WC Physics, Multidisciplinary SC Physics GA 263UA UT WOS:000084142600009 ER PT J AU Friedman, KS Clemente-Colon, P Pichel, WG Li, XF AF Friedman, KS Clemente-Colon, P Pichel, WG Li, XF TI Routine monitoring of changes in the Columbia Glacier, Alaska, with synthetic aperture radar SO REMOTE SENSING OF ENVIRONMENT LA English DT Article AB This study focuses on the use of spaceborne Synthetic Aperture Radar (SAR) from the European Remote Sensing Satellite (ERS-1) and the Canadian RADAR,FAT satellite to monitor retreating glaciers, specifically the Columbia Glacier, and the hazards caused by their recession on a routine basis. The Columbia Glacier is an important tidewater glacier to monitor because of its present rapid retreat, its generation of icebergs, and its vicinity to oil-tanker traffic in and out of the Port of Valdez, Alaska. We have established routine monitoring of the Prince William Sound area using SAR aboard the Canadian RADARSAT on a semi-weekly basis. To demonstrate the use of this data, four ERS-1 and seven RADARSAT SAR images from 1992 to 1998 are used in this study eo monitor the long-term retreat of the Columbia Glacier A loss of 17.7 +/- 0.2 square Kilometers is measured from 1992 to 1997, with 38.4% of this change occurring from 1993 to 1994. Also, hazards such as icebergs are monitored in near real-time. SAR is an efficient and cost-effective means of monitoring glaciers, where cloud cover and logistical costs and difficulties hamper other data-collection efforts. These data are available to U.S. Government users and would be of benefit to the Prince William Sound region if used operationally. Published by Elsevier Science Inc. C1 Caelum Res Corp, Camp Springs, MD 20746 USA. NOAA, NESDIS, Camp Springs, MD USA. Res & Data Syst Corp, Camp Springs, MD USA. RP Friedman, KS (reprint author), Caelum Res Corp, NOAA E-RA3,WWBG,Room 102,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 15 TC 3 Z9 3 U1 0 U2 2 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 1999 VL 70 IS 3 BP 257 EP 264 DI 10.1016/S0034-4257(99)00042-5 PG 8 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 266JF UT WOS:000084296300002 ER PT J AU Gao, RS McLaughlin, RJ Schein, ME Neuman, JA Ciciora, SJ Holecek, JC Fahey, DW AF Gao, RS McLaughlin, RJ Schein, ME Neuman, JA Ciciora, SJ Holecek, JC Fahey, DW TI Computer-controlled Teflon flow control valve SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A butterfly vane valve is described for the servo control of a gas or liquid flow. The valve is suitable for reactive species since nearly all wetted parts are Teflon. The valve is operated by a servo motor that is controlled by a dedicated microprocessor programmed in BASIC. The valve offers many other desirable features, including constant and relatively small surface area, low dead volume, high conductance in the full-open position, vacuum compatibility, firmware control, and scalability. (C) 1999 American Institute of Physics. [S0034-6748(99)03812-5]. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. RP Gao, RS (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Gao, Ru-Shan/H-7455-2013; McLaughlin, Richard/I-4386-2013; Ciciora, Steven/I-4916-2013; Fahey, David/G-4499-2013; Neuman, Andy/A-1393-2009 OI Fahey, David/0000-0003-1720-0634; Neuman, Andy/0000-0002-3986-1727 NR 3 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD DEC PY 1999 VL 70 IS 12 BP 4732 EP 4733 DI 10.1063/1.1150137 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 262EF UT WOS:000084052100045 ER PT J AU Potzick, J AF Potzick, J TI Reply to "Comment on 'Noise averaging and measurement resolution' " [Rev. Sci. Instrum. 70, 2038-2040 (1999)] SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Letter AB The Comment expands the scope of the original article. A subsequent expanded version of that article includes references to the work mentioned in the Comment. [S0034-6748(99)02912-3]. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Potzick, J (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD DEC PY 1999 VL 70 IS 12 BP 4735 EP 4735 DI 10.1063/1.1150144 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 262EF UT WOS:000084052100047 ER PT J AU Norton, JG AF Norton, JG TI Apparent habitat extensions of dolphinfish (Coryphaena hippurus) in response to climate transients in the California Current SO SCIENTIA MARINA LA English DT Article DE Coryphaena hippurus; dolphinfish; climate transients; California; Mexico; recreational fishery ID OCEANIC ROSSBY WAVES; EL-NINO SIGNAL; SOUTHERN-OSCILLATION; INTERDECADAL VARIABILITY; SURFACE-TEMPERATURE; NORTHEAST PACIFIC; NUMERICAL-MODEL; CURRENT SYSTEM; UNITED-STATES; BLUE MARLIN AB Dolphinfish, Coryphaena hippurus, a globally distributed, fast growing, predatory species has extended its habitat poleward off the west coast of North America in response to atmosphere-ocean climate transients that can be measured throughout the Pacific Ocean basin. Poleward habitat extension is measured by the availability of dolphinfish to southern California Commercial Passenger Fishing Vessel (CPFV) anglers. Before: 1972 the annual CPFV dolphinfish catch during the July-October fishing season seldom exceeded a few hundred fish. Thereafter, more than 10(3) dolphinfish were taken in 23 of the next 25 seasons. The next shift was in 1990 when catch exceeded 3.0 x 10(4) fish. More than 2.0 x 10(4) fish were reported in three of the next seven seasons. The apparent habitat extension coincides with increased ocean temperatures, forced by increases in North Pacific cyclogenesis and increases in downwelling coastal-trapped long wave transmission from the equatorial ocean. Interannual analysis shows that habitat expansion is associated with a decrease in upwelling off northern Mexico, which may be locally or remotely forced. Dolphinfish habitat shifts poleward in response to Pacific climate transients, reflecting global environmental trends. If subtropical ocean surface layers continue to warm throughout the world, as observed off southern California and northern Mexico, a global increase in the dolphinfish habitat is expected. C1 NOAA Fisheries, SW Fisheries Sci Ctr, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. RP Norton, JG (reprint author), NOAA Fisheries, SW Fisheries Sci Ctr, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. NR 73 TC 25 Z9 26 U1 0 U2 3 PU INST CIENCIAS MAR BARCELONA PI BARCELONA PA PASSEIG JOAN DE BORBO, 08039 BARCELONA, SPAIN SN 0214-8358 J9 SCI MAR JI Sci. Mar. PD DEC PY 1999 VL 63 IS 3-4 BP 239 EP 260 PG 22 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 277EH UT WOS:000084919400008 ER PT J AU Karl, TR Trenberth, KE AF Karl, TR Trenberth, KE TI The human impact on climate SO SCIENTIFIC AMERICAN LA English DT Article C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. Natl Ctr Atmospher Res, Climate Anal Sect, Boulder, CO 80307 USA. RP Karl, TR (reprint author), Natl Climat Data Ctr, Asheville, NC 28801 USA. RI Trenberth, Kevin/A-5683-2012 OI Trenberth, Kevin/0000-0002-1445-1000 NR 3 TC 6 Z9 6 U1 1 U2 4 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD DEC PY 1999 VL 281 IS 6 BP 100 EP 105 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 258TU UT WOS:000083855900028 ER PT J AU Fabijonas, BR Olver, FWJ AF Fabijonas, BR Olver, FWJ TI On the reversion of an asymptotic expansion and the zeros of the airy functions SO SIAM REVIEW LA English DT Article DE airy functions; asymptotic expansions; error bounds; inversion theorems; Lagrange's reversion theorem; phase principle; principle of the argument; symbolic computation; zeros AB The general theories of the derivation of inverses of functions from their power series and asymptotic expansions are discussed and compared. The asymptotic theory is applied to obtain asymptotic expansions of the zeros of the Airy functions and their derivatives, and also of the associated values of the functions or derivatives. A Maple code is constructed to generate exactly the coefficients in these expansions. The only limits on the number of coefficients are those imposed by the capacity of the computer being used and the execution time that is available. The sign patterns of the coefficients suggest open problems pertaining to error bounds for the asymptotic expansions of the zeros and stationary values of the Airy functions. C1 Natl Inst Stand & Technol, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Maryland, Dept Math, College Pk, MD 20742 USA. RP Fabijonas, BR (reprint author), So Methodist Univ, Dept Math, Dallas, TX 75243 USA. NR 12 TC 16 Z9 17 U1 2 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1445 J9 SIAM REV JI SIAM Rev. PD DEC PY 1999 VL 41 IS 4 BP 762 EP 773 DI 10.1137/S0036144598349538 PG 12 WC Mathematics, Applied SC Mathematics GA 262XY UT WOS:000084094600007 ER PT J AU Edmunds, JSG McCarthy, RA Ramsdell, JS AF Edmunds, JSG McCarthy, RA Ramsdell, JS TI Ciguatoxin reduces larval survivability in finfish SO TOXICON LA English DT Article ID CIGUATERA; FISH; EGGS AB Ciguatoxins are lipophilic polyether toxins which concentrate in the viscera and flesh of coral reef associated finfish (Hessel et al., 1960). In this study, we quantify the adverse effects of ciguatoxin on fish embryos by microinjection into the egg yolk of medaka (Oryzias latipis) embryos. Embryos microinjected with 0.1-0.9 pg/egg (ppb) of ciguatoxin exhibit cardiovascular, muscular, and skeletal abnormalities and those injected with higher levels (1.0-9.0 pg/egg) exhibit significantly reduced hatching success. The sensitivity of embryonic fish to direct oocyte exposure indicates that maternal transfer of low levels of ciguatoxin may represent an unrecognized threat to the reproductive success of reef fish and a previously undetected ecological consequence of proliferation of ciguatoxin-producing algae in reef systems increasingly impacted by human perturbations. Published by Elsevier Science Ltd. All rights reserved. C1 NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxin Program, Charleston, SC 29412 USA. Med Univ S Carolina, Dept Cell Biol & Anat, Charleston, SC 29425 USA. RP Ramsdell, JS (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxin Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 19 TC 24 Z9 25 U1 3 U2 12 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 DEC PY 1999 VL 37 IS 12 BP 1827 EP 1832 DI 10.1016/S0041-0101(99)00119-1 PG 6 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 237XT UT WOS:000082682400015 PM 10519658 ER PT J AU Schlenoff, C Gruninger, M Ciocoiu, M Lee, JT AF Schlenoff, C Gruninger, M Ciocoiu, M Lee, JT TI The essence of the process specification language SO TRANSACTIONS OF THE SOCIETY FOR COMPUTER SIMULATION INTERNATIONAL LA English DT Article DE manufacturing process specification; PSL; interoperability; ontology AB In all types of communication, the ability to share information is often hindered because the meaning of that information can be affected drastically by the context in which it is viewed and interpreted This is especially tore among manufacturing simulation systems because of the growing complexity of manufacturing information and the increasing need to exchange this information not only among different simulation systems but also between simulation systems and systems that perform different functions (e.g., process planning, scheduling, etc.). Different manufacturing functions may use different terms to mean the exact same concept or use the exact same terms to mean very different concepts. Often, the loosely defined natural language definitions associated with the terms contain much ambiguity that doesn't make these differences evident and/or do not provide enough information to resolve the differences. A solution to this problem is the development of a taxonomy or ontology of manufacturing concepts and terms along with their respective formal and unambiguous definitions. The Process Specification Language (PSL) (Version 1.0) developed at the National Institute of Standards and Technology identifies, formally defines, and structures the semantic concepts intrinsic to the capture and exchange of discrete manufacturing process information. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Toronto, Dept Mech & Ind Engn, Toronto, ON M5S 3G9, Canada. Univ Maryland, Syst Res Inst, College Pk, MD 20742 USA. Univ Colorado, Boulder, CO 80309 USA. RP Schlenoff, C (reprint author), Natl Inst Stand & Technol, Bldg 220,Room A127, Gaithersburg, MD 20899 USA. NR 15 TC 17 Z9 17 U1 0 U2 0 PU SOC COMPUTER SIMULATION PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92177 USA SN 0740-6797 J9 T SOC COMPUT SIMUL I JI Trans. Soc. Comput. Simul. PD DEC PY 1999 VL 16 IS 4 BP 204 EP 216 PG 13 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 299YD UT WOS:000086225300007 ER PT J AU Bromwich, DH Cullather, RI Grumbine, RW AF Bromwich, DH Cullather, RI Grumbine, RW TI An assessment of the NCEP operational global spectral model forecasts and analyses for Antarctica during FROST SO WEATHER AND FORECASTING LA English DT Article ID SOUTHERN-HEMISPHERE; TEMPERATURE INVERSION; SURFACE TEMPERATURE; NUMERICAL-ANALYSES; CLIMATE; PRECIPITATION; SIMULATION; PREDICTABILITY; OSCILLATION; NCEP/NCAR AB Analyses and medium-range numerical weather forecasts produced by the National Centers for Environmental Prediction are evaluated poleward of 50 degrees S during the July 1994 special observing period of the Antarctic First Regional Observing Study of the Troposphere project. Over the Antarctic plateau, the poor representation of the continent's terrain creates ambiguity in assessing the quality of surface variables. An examination of the vertical temperature profile, however, finds the near-surface temperature inversion strength to be substantially smaller than the observed climatology at the zero forecast hour. This arises, from surface temperatures that are warmer than expected. Significant adjustment occurs in a variety of fields over the first few days of the medium-range forecast, which likely results from the initial hour's suspect temperature profile. A spatially oscillating series of forecast anomalies in the zonally averaged temperature cross section stretches to middle latitudes by day 3. Near-surface and upper-troposphere values are found actually to improve at the South Pole with forecast time, although some fields continue to adjust through day 7. Although the examination presented here does nor give a complete diagnosis. differences between observations and analyses Suggest deficiencies with the model initial fields have a major role in producing the substantial model drift found. Atmospheric moisture over the continental interior does not change significantly with forecast hour, although the distinct contrast between nearshore and interior conditions lessens with forecast time. A spurious high-latitude wave pattern is found for a variety of variables. The pattern of this distortion remains constant with forecast hour. Over the ocean, large forecast pressure and height differences with analyses are associated with blocking conditions. However, it is unclear whether this results from deficiencies in the forecast model or the meager observational network over the Southern Ocean. C1 Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, Columbus, OH 43210 USA. Natl Ctr Environm Predict, Camp Springs, MD USA. Ohio State Univ, Dept Geog, Atmospher Sci Program, Columbus, OH 43210 USA. RP Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, 1090 Carmack Rd, Columbus, OH 43210 USA. EM Bromwich.1@osu.edu RI Grumbine, Robert/B-9865-2008; Bromwich, David/C-9225-2016 NR 35 TC 18 Z9 20 U1 0 U2 1 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. PD DEC PY 1999 VL 14 IS 6 BP 835 EP 850 DI 10.1175/1520-0434(1999)014<0835:AAOTNO>2.0.CO;2 PN 1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VU UT WOS:000084380600004 ER PT J AU Hines, KM Grumbine, RW Bromwich, DH Cullather, RI AF Hines, KM Grumbine, RW Bromwich, DH Cullather, RI TI Surface energy balance of the NCEP MRF and NCEP-NCAR reanalysis in Antarctic latitudes during FROST SO WEATHER AND FORECASTING LA English DT Article ID RANGE FORECAST MODEL; SOIL HYDROLOGY; NMC; VALIDATION; CONTINENT; PROJECT; SYSTEM AB The surface energy budget in Antarctic latitudes is evaluated for the medium-range numerical weather forecasts produced by the National Centers for Environmental Prediction (NCEP) and for the NCEP-National Center for Atmospheric Research reanalysis project during the winter, spring. and summer special observing periods (SOPs) of the Antarctic First Regional Observing Study of Troposphere project. A significant change in the energy balance resulted from an extensive model update beginning with the forecasts initialized on 11 January 1995 during the summer SOP. Both the forecasts and the reanalysis include significant errors in the surface energy balance over Antarctica. The errors often tend to cancel and thus produce reasonable surface temperature fields. General errors include downward longwave radiation about 30-50 W m(-2) too small. Lower than observed cloudiness contributes to this error and to excessive downward shortwave radiation at the surface. The model albedo over Antarctica, about 75%, is lower than that derived from observations, about 81%. During the polar day, errors in net longwave and net shortwave radiation tend to cancel. The energy balance over Antarctica in the reanalysis is, in general, degraded from that of the forecasts. Seasonal characteristics of the surface energy balance include cooling over East Antarctica and slight warming over West Antarctica during NCEP forecasts for the winter SOP. Wintertime surface warming by downward sensible hear Aux is larger than observations by 21-36 W m(-2) and tends to balance the excessive longwave cooling at the surface. During the spring SOP, forecast sensible heat flux Produces an excessive hearing contribution by about 20 W m(-2). Latent heat flux during the Antarctic winter for the reanalysis is at least an order of magnitude larger than the very small observed values. C1 Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, Columbus, OH 43210 USA. Natl Ctr Environm Predict, Camp Springs, MD USA. Ohio State Univ, Atmospher Sci Program, Columbus, OH 43210 USA. Ohio State Univ, Dept Geog, Columbus, OH 43210 USA. RP Hines, KM (reprint author), Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, 1090 Carmack Rd, Columbus, OH 43210 USA. RI Grumbine, Robert/B-9865-2008; Bromwich, David/C-9225-2016 NR 40 TC 21 Z9 23 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 851 EP 866 DI 10.1175/1520-0434(1999)014<0851:SEBOTN>2.0.CO;2 PN 1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VU UT WOS:000084380600005 ER PT J AU Sousounis, PJ Mann, GE Young, GS Wagenmaker, RB Hoggatt, BD Badini, WJ AF Sousounis, PJ Mann, GE Young, GS Wagenmaker, RB Hoggatt, BD Badini, WJ TI Forecasting during the Lake-ICE/SNOWBANDS Field Experiments SO WEATHER AND FORECASTING LA English DT Article ID EFFECT SNOW; CYCLONE AB Despite improvements in numerical weather prediction models, statistical models, forecast decision trees, and forecasting rules of thumb, human interpretation of meteorological information for a particular forecast situation can still yield a forecast that is superior to ones based solely on automated output. While such time-intensive activities may not be cost effective for routine operational forecasts, they may be crucial for the success of costly field experiments, The Lake-Induced Convection Experiment (Lake-ICE) and the Snowband Dynamics Experiment (SNOWBANDS) were conducted over the Great Lakes region during the 1997/98 winter. Project forecasters consisted of members of the academic as well as the operational forecast communities. The forecasters relied on traditional operationally available data as well as project-tailored information from special project soundings and locally run mesoscale models. The forecasting activities during Lake-ICE/SNOWBANDS are a prime example of how the man-machine mix of the forecast process can contribute significantly to forecast improvements over what is available from raw model output or even using traditional operational forecast techniques. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Penn State Univ, University Pk, PA 16802 USA. NOAA, Natl Weather Serv, Pontiac, MI USA. Univ Wisconsin, Madison, WI USA. RP Sousounis, PJ (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NR 21 TC 9 Z9 9 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 955 EP 975 DI 10.1175/1520-0434(1999)014<0955:FDTLIS>2.0.CO;2 PN 2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000002 ER PT J AU Funk, TW Darmofal, KE Kirkpatrick, JD DeWald, VL Przybylinski, RW Schmocker, GK Lin, YJ AF Funk, TW Darmofal, KE Kirkpatrick, JD DeWald, VL Przybylinski, RW Schmocker, GK Lin, YJ TI Storm reflectivity and mesocyclone evolution associated with the 15 April 1994 squall line over Kentucky and southern Indiana SO WEATHER AND FORECASTING LA English DT Article ID SIMULATED CONVECTIVE STORMS; REAR-INFLOW; BOW ECHO; CLASSIFICATION; PRECIPITATION; TORNADOES; SYSTEMS AB A long-lived highly organized squall line moved rapidly across the middle Mississippi and Ohio Valleys on 15 April 1994 within a moderately unstable. strongly sheared environment. Over Kentucky and southern Indiana, the line contained several bowing segments (bow echoes) that resulted in widespread wind damage, numerous shear vortices/rotational circulations, and several tornadoes that produced F0-F2 damage. In this study, the Louisville-Fort Knox WSR-88D is used to present a thorough discussion of a particularly long-tracked bowing line segment over central Kentucky that exhibited a very complex and detailed evolution, more so than any other segment throughout the life span of the squall line. Specifically, this segment produced abundant straight-line wind damage; cyclic, multiple core cyclonic circulations, some of which met mesocyclone criteria; several tornadoes; and embedded high precipitation supercell-like structure that evolved into a rotating comma head-comma tail pattern. The bowing segment also is examined for the presence of bookend vortices aloft and midaltitude radial convergence. In addition, the structure of other bowing segments and their attendant circulations within the squall line are discussed and compared with existing documentation. Radar sampling issues and ramifications of the squall line's complicated structure on the warning process of future similar severe weather events are touched upon as well. C1 NOAA, Natl Weather Serv, Forecast Off, Louisville, KY 40229 USA. NOAA, Natl Weather Serv, Forecast Off, St Charles, MO USA. St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO USA. RP Funk, TW (reprint author), NOAA, Natl Weather Serv, Forecast Off, 6201 Theiler Lane, Louisville, KY 40229 USA. NR 42 TC 35 Z9 38 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 976 EP 993 DI 10.1175/1520-0434(1999)014<0976:SRAMEA>2.0.CO;2 PN 2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000003 ER PT J AU Wallace, CE Maddox, RA Howard, KW AF Wallace, CE Maddox, RA Howard, KW TI Summertime convective storm environments in central Arizona: Local observations SO WEATHER AND FORECASTING LA English DT Article ID SOUTHWESTERN UNITED-STATES; MONSOON; PATTERNS; GULF; CALIFORNIA; PREDICTION; FORECASTS; BURSTS; BREAKS; AIR AB The daily evolution of local surface conditions at Phoenix, Arizona, and the characteristics of the 1200 UTC sounding at Tucson, Arizona, have been examined to determine important meteorological features that lead to thunderstorm occurrence over the low deserts of central Arizona. Each day of July and August during the period 1990-95 has been stratified based upon daily mean, surface moisture conditions at Phoenix, Arizona, and the occurrence of afternoon and evening convective activity in the Phoenix metropolitan area. The nearest operational sounding, taken 160 km to the southeast at Tucson, is shown to be nor representative of low-level thermodynamic conditions in central Arizona. Thus, Phoenix forecasters' ability to identify precursor conditions for the development of thunderstorms is impaired. On days that convective storms occur in the Phoenix area, there is a decrease in the diurnal amplitude of surface dewpoint changes, signifying increased/deeper boundary layer moisture. This signal is very subtle and may nor have much forecast utility. Additionally, it is found that surges of moist air from the Gulf of California do not occur frequently during the 36-48 h immediately prior to thunderstorm events in the Phoenix area. It is shown that the 1200 UTC Tucson wind profile has a significant northerly flow in low levels on moist days when storms do not occur in the Phoenix area. The forecaster needs information on the local temperature and moisture profile to assess the potential for thunderstorms in the Phoenix area. However, routine upper-air observations are unavailable. Steps are being taken to obtain morning soundings in Phoenix, and the improving capabilities of satellite-derived thermodynamic data and mesoscale models may also provide the forecaster critical information in the future. The findings, although specifically developed for the Phoenix area, may be relevant to thunderstorm forecasting in many regions of the interior West. C1 NOAA, Environm Res Labs, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Wallace, CE (reprint author), 1400 Independence Ave SW,S Agr Bldg,Rm 5844, Washington, DC 20250 USA. NR 27 TC 19 Z9 20 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 994 EP 1006 DI 10.1175/1520-0434(1999)014<0994:SCSEIC>2.0.CO;2 PN 2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000004 ER PT J AU Marzban, C Mitchell, ED Stumpf, GJ AF Marzban, C Mitchell, ED Stumpf, GJ TI The notion of "best predictors": An application to tornado prediction SO WEATHER AND FORECASTING LA English DT Article ID NEURAL-NETWORK; PERFORMANCE AB It is argued that the strength of a predictor is an ill-defined concept. At best, it is contingent on many assumptions, and, at worst, it is an ambiguous quantity. It is shown that many of the contingencies are met (or avoided) only in a bivariate sense, that is, one independent variable (and one dependent variable) at a time. Several such methods are offered after which data produced by the National Severe Storms Laboratory's Tornado Detection Algorithm are analyzed for the purpose of addressing the question of which storm-scale vortex attributes based on Doppler radar constitute the "best predictors" of tornadoes. C1 Univ Oklahoma, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale & Meteorol Studies, Norman, OK 73069 USA. Univ Oklahoma, Dept Phys, Norman, OK 73069 USA. RP Marzban, C (reprint author), Univ Oklahoma, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 15 TC 16 Z9 16 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 1007 EP 1016 DI 10.1175/1520-0434(1999)014<1007:TNOBPA>2.0.CO;2 PN 2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000005 ER PT J AU Schultz, DM AF Schultz, DM TI Lake-effect snowstorms in northern Utah and western New York with and without lightning SO WEATHER AND FORECASTING LA English DT Article ID FRONTAL SURFACES; POSITIVE CAPE; THUNDERSTORMS; THUNDERCLOUDS; ENVIRONMENTS AB Lake-effect snowstorms in northern Utah and western New York with and without lightning/thunder are examined. Lake-effect snowstorms with lightning have significantly higher temperatures and dewpoints in the lower troposphere and significantly lower lifted indices than lake-effect snowstorms without lightning. In contrast, there is little difference in dewpoint depressions between events with and without lightning. Surface-to-700-hPa temperature differences (a surrogate for lower-tropospheric lapse rate) for events with and without lightning differ significantly for events in northern Utah, but nor for those in western New York. Nearly all events have no convective available potential energy, regardless of the presence of lightning. These results are discussed in the context of current models of storm electrification. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Schultz, DM (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. RI Schultz, David M./A-3091-2010 OI Schultz, David M./0000-0003-1558-6975 NR 32 TC 20 Z9 20 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 1023 EP 1031 DI 10.1175/1520-0434(1999)014<1023:LESINU>2.0.CO;2 PN 2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000007 ER PT J AU Benjamin, SG Schwartz, BE Cole, RE AF Benjamin, SG Schwartz, BE Cole, RE TI Accuracy of ACARS wind and temperature observations determined by collocation SO WEATHER AND FORECASTING LA English DT Article ID AIRCRAFT; PREDICTION; SYSTEM AB A collocation study of meteorological reports from commercial aircraft relayed through the Aircraft Communications, Addressing, and Reporting System (ACARS) has been performed to estimate standard deviations of observation errors for wind and temperature. ACARS observations were collected over an area in the western and central United States for a 13-month period, and this dataset was examined for pairs of reports within small spatial (less than or equal to 10 km) and temporal (less than or equal to 10 min) windows. The results showed an observation error of a single horizontal component of wind of 1.1 m s(-1) and 0.5 K for temperature above the boundary layer. Within the boundary layer, the rms difference of wind and temperature between aircraft was larger, presumably due to larger small-scale variations in the atmosphere and, in the case of wind, from aircraft maneuvers. These observation error estimates are valuable for use in data assimilation and for determination of forecast error from ACARS observation-minus-forecast differences. By comparing standard deviations at different levels, estimates of mesoscale variability at a 10-km scale in the lower troposphere were also calculated. These values (rms vector error of 1.8 m s(-1) for wind, rms error of 0.5 K for temperature) can be interpreted as estimates of the 10-km lower-tropospheric error of representativeness. also useful for data assimilation. C1 NOAA, Environm Res Lab, Forecast Syst Lab, Boulder, CO 80303 USA. RP Benjamin, SG (reprint author), NOAA, Environm Res Lab, Forecast Syst Lab, 325 Boradway, Boulder, CO 80303 USA. RI Benjamin, Stan/C-5818-2015 OI Benjamin, Stan/0000-0002-5751-8236 NR 17 TC 40 Z9 45 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1999 VL 14 IS 6 BP 1032 EP 1038 DI 10.1175/1520-0434(1999)014<1032:AOAWAT>2.0.CO;2 PN 2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 267VY UT WOS:000084381000008 ER PT J AU Wiederhorn, SM AF Wiederhorn, SM TI High temperature deformation of silicon nitride SO ZEITSCHRIFT FUR METALLKUNDE LA English DT Article ID GRAIN-BOUNDARY PHASE; COMPRESSION CREEP; TENSILE CREEP; CERAMICS; SI3N4; MECHANISM; BEHAVIOR; ALLOYS; DENSE AB Three mechanisms for the creep of silicon nitride are discussed with regard to the microstructural variables that control creep. During the initial stages of creep, the amorphous silicate layer that coats all grains of silicon nitride is displaced from grain boundaries where the pressure is high to boundaries where the pressure is low. Once the amorphous layer has been entirely displaced from the grain boundaries, other mechanisms of deformation take over: solution-precipitation in compression; cavity formation in tension. Models of deformation for these three mechanisms suggest that the most important variable for improving creep resistance is the apparent viscosity of the intergranular phase, followed by the volume fraction of intergranular phase. In tension, grain size does not play the same important role in controlling creep as it does in compression. C1 NIST, Gaithersburg, MD 20899 USA. RP Wiederhorn, SM (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 50 TC 7 Z9 7 U1 0 U2 1 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 86 04 20, D-81679 MUNICH, GERMANY SN 0044-3093 J9 Z METALLKD JI Z. Metallk. PD DEC PY 1999 VL 90 IS 12 BP 1053 EP 1058 PG 6 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 269LQ UT WOS:000084479300015 ER PT J AU Koshyk, JN Boville, BA Hamilton, K Manzini, E Shibata, K AF Koshyk, JN Boville, BA Hamilton, K Manzini, E Shibata, K TI Kinetic energy spectrum of horizontal motions in middle-atmosphere models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; GRAVITY-WAVES; PARAMETERIZATION; STRATOSPHERE; TURBULENCE; TROPOSPHERE; CONVECTION; SIMULATION; REPRESENTATION; CLIMATOLOGY AB Data from several middle-atmosphere general circulation models are used to calculate kinetic energy spectra as a function of total horizontal wavenumber n. The horizontal and vertical resolution between models varies but all have upper. boundaries at heights greater than or similar to 80 km. Tropospheric spectra show power-law behavior with slopes slightly shallower than -3 for wavenumbers n greater than or similar to 10 (horizontal wavelengths less than or similar to 4000 km) and are dominated by the rotational part of the flow. These spectra agree well with those calculated using data obtained from a global assimilation model and with the results of previous observational studies. Stratospheric spectra have larger amplitudes than tropospheric ones at planetary scales and smaller amplitudes at smaller scales. Mesospheric spectra are characterized by enhanced spectral amplitudes at all wavenumbers compared to the stratosphere and spectral slopes in the wavenumber range n greater than or similar to 10 are generally shallower. Stratospheric and mesospheric spectra include approximately equal contributions from the rotational and divergent parts of the flow for n greater than or similar to 20 in all models. These features appear to be independent of model resolution. The divergent part of the flow, presumably associated with explicitly resolved inertiogravity waves in the models, increases more rapidly with height above the lower stratosphere than the rotational part. The divergent part is fairly insensitive to season, whereas the rotational part changes considerably between January and July in the middle-atmosphere region. Spectral amplitudes and vertical growth rates of both parts vary widely between models for a given season. The horizontal diffusion schemes used by the models are compared in an attempt to explain some of these differences. C1 Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Natl Ctr Atmospher Res, Climate Modelling Sect, Boulder, CO 80307 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Meteorol Res Inst, Climate Res Dept, Tsukuba, Ibaraki 3050052, Japan. RP Koshyk, JN (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. EM koshyk@mam.physics.utoronto.ca; boville@ncar.ucar.edu; kph@gfdl.gov; manzini@dkrz.de; kshibata@mri-jma.go.jp RI Manzini, Elisa/H-5760-2011 NR 44 TC 55 Z9 56 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 NOV 27 PY 1999 VL 104 IS D22 BP 27177 EP 27190 DI 10.1029/1999JD900814 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259BT UT WOS:000083874700001 ER PT J AU Neff, WD AF Neff, WD TI Decadal time scale trends and variability in the tropospheric circulation over the South Pole SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID ANTARCTIC OZONE HOLE; QUASI-BIENNIAL OSCILLATION; SEA-ICE CONCENTRATION; ATMOSPHERIC CIRCULATION; SEMIANNUAL OSCILLATION; SURFACE-TEMPERATURE; AIR-TEMPERATURE; KATABATIC WINDS; EAST-ANTARCTICA; FLOW PATTERNS AB This paper documents significant long-term changes in the tropospheric circulation and progression of the seasonal cycle over the South Pole and relates aspects of the changes to the enhanced springtime stratospheric ozone depletion of recent decades. During the winter-to-summer transition over Antarctica, the formation of the thermal tropopause above 150 hPa is now delayed by a month compared to the early 1960s. A similar delay occurs in the breakdown of the winter polar stratospheric vortex, a prerequisite to the formation of the strong summertime tropopause near 300 hPa A delay in tropopause formation implies delays in those aspects of the transition from winter to summer in the dynamics of the troposphere that are sensitive to its upper boundary condition, including the contraction of the Rossby radius of deformation during the shallow troposphere phase of summer. Consistent with this expectation, the normal springtime decline of baroclinic-eddy activity in the lower troposphere now occurs later by a month. Similar delays occur in the time of an early summer minimum in total cloud fraction that coincides with the time of the maximum stratification between 150 and 100 hPa. In addition, the analyses reveal (1) an increase of 15 to 20% in spring and summer cloud fraction over the last four decades; (2) a separation of spring and summer cloudiness into two transport regimes with a distinct intervening minimum in cloud fraction; (3) a decadal modulation of springtime cloudiness that is coincident with decadal shifts in the directional mode of 300-hPa winds following solar minima; (4) a long-term increase in total inversion strength, inversion depth, and 650-to 300-hPa thickness; and (5) a long-term decrease in wintertime surface wind speed, surface temperature, and near-surface lapse rate. The study also introduces a covariance technique that exploits the control by continental-scale orography of synoptic and surface flow regimes, increasing the value of lower tropospheric observations for the study of climate change over Antarctica. Finally, a cautionary note arises from the apparent effect of the Weddell Polynyas and the reduction of the maximum extent of sea ice of the middle to late 1970s, with increased tropospheric and lower stratospheric temperatures and an earlier time of formation of the tropopause. This observation suggests that the occurrence of decadal and subdecadal variability in the ocean and the atmosphere of the Southern Hemisphere may obscure the detection of long-term trends in the circulation over Antarctica. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ Colorado, Div Cryospher & Polar Proc, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Neff, WD (reprint author), NOAA, Environm Technol Lab, 325 Broadway,R-E-ET7, Boulder, CO 80303 USA. EM wneff@etl.noaa.gov RI Neff, William/E-2725-2010 OI Neff, William/0000-0003-4047-7076 NR 126 TC 33 Z9 38 U1 2 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 1999 VL 104 IS D22 BP 27217 EP 27251 DI 10.1029/1999JD900483 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259BT UT WOS:000083874700005 ER PT J AU Karcher, B Solomon, S AF Karcher, B Solomon, S TI On the composition and optical extinction of particles in the tropopause region SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID STRATOSPHERIC AEROSOL-PARTICLES; CIRRUS CLOUDS; WATER-VAPOR; UPPER TROPOSPHERE; MICROPHYSICAL PROPERTIES; VOLCANIC AEROSOLS; SULFURIC-ACID; HETEROGENEOUS CHEMISTRY; CLIMATIC IMPLICATIONS; TROPICAL TROPOPAUSE AB Liquid aerosol particles and ice crystals in subvisible cirrus clouds in the tropopause region are characterized in terms of size distributions, chemical composition, and optical extinction. These particle properties are studied by means of simple models and are related to satellite extinction measurements, particularly for midlatitudes. Sulfuric acid aerosols can take up nitric acid near the ice frost point, just before ice nucleation. Aerosols in the tropopause region may show a larger spread of extinction and extinction ratios at different wavelengths than background stratospheric aerosols. The high surface areas and low extinction ratios of subvisible cirrus deduced from satellite observations are unlikely to be due purely to aerosols, except for high sulfate loadings. It is shown that mixtures of liquid aerosols and ice particles can more readily explain these data with only small cloud fractions along the line of sight of the optical sensors. The efficiency of heterogeneous chlorine activation in aerosol/cloud mixtures, the availability of water vapor, sulfate, and nitrate, and the effects of temperature, ammonium, organics, ice nuclei and aircraft emissions on the properties of particles in the tropopause region are explored. C1 DLR, Inst Phys Atmosphare, D-82234 Wessling, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Karcher, B (reprint author), DLR, Inst Phys Atmosphare, D-82234 Wessling, Germany. EM bernd.kaercher@dlr.de; solomon@al.noaa.gov RI Karcher, Bernd/D-5325-2014 OI Karcher, Bernd/0000-0003-0278-4980 NR 107 TC 39 Z9 39 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 NOV 27 PY 1999 VL 104 IS D22 BP 27441 EP 27459 DI 10.1029/1999JD900838 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259BT UT WOS:000083874700017 ER PT J AU Lee, DH Abriola, LM AF Lee, DH Abriola, LM TI Use of the Richards equation in land surface parameterizations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOIL-MOISTURE; MODEL; HYDROLOGY; LAYER AB Accurately modeling infiltration and soil moisture within land surface parameterization schemes (LSPs) of coupled land surface-atmosphere models is essential for producing realistic simulations of energy and moisture fluxes and for partitioning precipitation into infiltration, surface runoff, and drainage to groundwater. This report compares simulations of soil moisture, runoff, infiltration, and drainage to groundwater for a bare clay loam using three approaches: a finite difference solution of the vertically integrated Richards equation (an approach commonly used in LSPs), st highly resolved (spatially and temporally) finite element solution of Richards equation, and an analytical kinematic wave solution of Richards equation. Comparisons show that depth-averaged soil moisture simulated using the vertically integrated Richards equation is only similar to those of the finite element solution for vertical spatial discretizations finer than those employed by most state-of-the-art land surface-atmosphere transfer schemes. The vertically integrated Richards equation overpredicts soil moisture in the near-surface soil column and underpredicts drainage to groundwater. The infiltration formulation is found to be critical in partitioning precipitation into runoff, soil moisture, and drainage. Different infiltration formulations and vertical spatial discretizations may partly explain the very different land surface moisture and energy fluxes reported by the LSPs evaluated as part of the Project for Intercomparison of Land Surface Parameterization Schemes (PILPS) Phase 2(b) experiment. C1 NWS Ohio River Forecast Ctr, Wilmington, OH 45177 USA. Univ Michigan, Dept Civil & Environm Engn, Ann Arbor, MI 48109 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Lee, DH (reprint author), NWS Ohio River Forecast Ctr, 1901 S State St,Route 134, Wilmington, OH 45177 USA. EM deborah.lee@noaa.gov; Linda_Abriola@um.cc.umich.edu RI Abriola, Linda/F-7624-2010 NR 12 TC 21 Z9 24 U1 1 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 NOV 27 PY 1999 VL 104 IS D22 BP 27519 EP 27526 DI 10.1029/1999JD900951 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259BT UT WOS:000083874700022 ER PT J AU McIntosh, A Walther, T Lucchese, RR Bevan, JW Suenram, RD Legon, AC AF McIntosh, A Walther, T Lucchese, RR Bevan, JW Suenram, RD Legon, AC TI The microwave spectrum and ground-state structure of H2O center dot center dot center dot HI SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LEVEL-CORRELATED CALCULATIONS; MOLECULAR ELECTRIC PROPERTIES; POLARIZED BASIS-SETS; ROTATIONAL SPECTRUM; GAS-PHASE; PULSED-NOZZLE; WATER DIMER; HYDROGEN; SPECTROSCOPY; CONSTANTS AB The microwave spectrum and ground-state structure of H2O ... HI are reported. The fitted ground-state constants include: A(0) = 428.9 GHz, B-0 = 2189.7351(5) MHz, C-0 = 2175.9546(5) MHz, chi(aa) = -1479.399(10) MHz, (chi(bb)-chi(cc)) = -17.37(1) MHz. Evidence will be presented for a complex that has an R(O-I) distance equal to 3.745(2) Angstrom. The reduction of chi(aa) from the value chi(0) in the free HI molecule, corresponds to a zero-point oscillation angle theta(av) = cos(-1)([cos(2) theta](1/2)) = 20.89(2)degrees. Ab initio calculations support the conclusion that the ground vibrational state for the H2O flapping mode is delocalized between two equilibrium structures at an energy above an inversion barrier. (C) 1999 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. Univ Exeter, Dept Chem, Exeter EX4 4QD, Devon, England. RP Bevan, JW (reprint author), Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. RI Bevan, John/B-6529-2015; Walther, Thomas/C-6212-2016; Lucchese, Robert/O-4452-2014 OI Bevan, John/0000-0003-0264-6596; Walther, Thomas/0000-0001-8114-1785; Lucchese, Robert/0000-0002-7200-3775 NR 25 TC 13 Z9 13 U1 0 U2 5 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 26 PY 1999 VL 314 IS 1-2 BP 57 EP 64 DI 10.1016/S0009-2614(99)01027-1 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 260MW UT WOS:000083955300011 ER PT J AU Black, DE Peterson, LC Overpeck, JT Kaplan, A Evans, MN Kashgarian, M AF Black, DE Peterson, LC Overpeck, JT Kaplan, A Evans, MN Kashgarian, M TI Eight centuries of North Atlantic Ocean atmosphere variability SO SCIENCE LA English DT Article ID SEA-SURFACE TEMPERATURE; TROPICAL ATLANTIC; CLIMATE-CHANGE; LAST DEGLACIATION; GREENLAND SEA; UNITED-STATES; CARIACO BASIN; ICE-AGE; CIRCULATION; MODEL AB Climate in the tropical North Atlantic is controlled Largely by variations in the strength of the trade winds, the position of the Intertropical Convergence Zone, and sea surface temperatures. A high-resolution study of Caribbean sediments provides a subdecadally resolved record of tropical upwelling and trade wind Variability spanning the past 825 years. These results confirm the importance of a decadal (12- to 13-year) mode of Atlantic variability believed to be driven by coupled tropical ocean-atmosphere dynamics. Although a well-defined interdecadal mode of variability does not appear to be characteristic of the tropical Atlantic, there is evidence that century-scale variability is substantial. The tropical Atlantic may also have been involved in a major shift in Northern Hemisphere climate variability that took place about 700 years ago. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Colorado, NOAA, Paleoclimatol Program, Boulder, CO 80309 USA. Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Black, DE (reprint author), Univ S Carolina, Dept Geol Sci, Columbia, SC 29208 USA. RI Kashgarian, Michaele/E-1665-2011; OI Kashgarian, Michaele/0000-0001-7824-8418; Black, David/0000-0002-9601-6642 NR 58 TC 153 Z9 154 U1 0 U2 17 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 26 PY 1999 VL 286 IS 5445 BP 1709 EP 1713 DI 10.1126/science.286.5445.1709 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 259UK UT WOS:000083912200030 ER PT J AU Van Poolen, LJ Holcomb, CD AF Van Poolen, LJ Holcomb, CD TI Critical temperatures, pressures, and densities for the mixtures CO2-C3H8, CO2-nC(4)H(10), C2H6-C3H8, and C3H8-nC(4)H(10) SO FLUID PHASE EQUILIBRIA LA English DT Article DE critical state; mixture; method of calculation; carbon dioxide; hydrocarbons; vapor-liquid equilibria ID VAPOR-LIQUID-EQUILIBRIUM; BINARY-SYSTEMS; NORMAL-BUTANE AB A simple method is developed to estimate mixture critical temperatures (T-c), pressures (P-c), and densities (rho(c)) as a function of overall composition (X) from near critical region experimental coexistence data. This three-step method is applied to four mixtures, CO2-C3H8, CO2-nC(4)H(10), C2H6-C3H8, and C3H8-nC(4)H(10). Isothermal Liquid-vapor coexistence data, which includes temperature, vapor pressure, coexisting densities (rho(l) and rho(v)), and coexisting compositions for the more volatile component (x(1)(v) and x(1)(l)) are used. In the first step, the difference of the saturated liquid and vapor densities (rho(l) - rho(v)) is fitted to an empirical function in ((P-c - P)/P-c) to obtain P-c. Then P/P-c and ((rho(l) + rho(v))/2 rho(c)) are simultaneously fitted to functions of a points are fitted with an equation to provide a continuous representation of the critical lines. The method is successfully tested for the mixtures, CO2-C3H8 and CO2-nC(4)H(10), for which there is a reasonable amount of isothermal data. The procedure is then applied to the mixtures, C2H6-C3H8 and C3H8-nC(4)H(10), for which there are sparse data. For all four mixtures, the critical temperature line, T-c vs. X-1, matches literature values within +/- 0.5%. The critical pressure Line, P-c vs. X-1, and critical density line, rho(c) vs. X-1, match literature values, in general, within +/- 2%. (C) 1999 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80303 USA. Calvin Coll, Dept Engn, Grand Rapids, MI 49546 USA. RP Holcomb, CD (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 19 TC 4 Z9 4 U1 1 U2 5 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 25 PY 1999 VL 165 IS 2 BP 157 EP 168 DI 10.1016/S0378-3812(99)00275-7 PG 12 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 260HL UT WOS:000083943400002 ER PT J AU Coxon, B AF Coxon, B TI Boat conformations: synthesis, NMR spectroscopy, and molecular modeling of methyl 2,6-anhydro-3-deoxy-3-phthalimido-alpha-D-mannopyranoside and its N-15-labeled analog SO CARBOHYDRATE RESEARCH LA English DT Article DE 2,6-anhydrides; boat conformations; carbon-13-proton chemical shift correlation; carbon-13-nitrogen-15 and; nitrogen-15-proton coupling constants; gradient-enhanced 2D HSQC; mannopyranoside; molecular dynamics; phthalimido derivatives; simulated annealing ID COUPLING-CONSTANTS; FIELD AB Methyl 2,6-anhydro-3-deoxy-3-phthalimido-alpha-D-mannopyranoside and its N-15-labeled analog have been synthesized by reaction of methyl 2,6:3,4-dianhydro-alpha-D-altropyranoside with a mixture of phthalimide and potassium phthalimide or their N-15-labeled analogs. The geometry of the skew conformation of the mannopyranoside derivative has been characterized by molecular dynamics with simulated annealing and correlated with vicinal and long-range H-1-H-1 and vicinal H-1-N-15 coupling constants measured by H-1 NMR spectroscopy. Dihedral angle comparisons have been made with derivatives of the parent 2,2,2-bicyclo-octane structure. The H-1-N-15 coupling constant data provide further values for definition of a Karplus equation for analysis of the stereochemistry of aminoglycosides. Published by Elsevier Science Ltd. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Coxon, B (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 21 TC 6 Z9 6 U1 1 U2 1 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 NOV 23 PY 1999 VL 322 IS 1-2 BP 120 EP 127 DI 10.1016/S0008-6215(99)00209-8 PG 8 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA 264WB UT WOS:000084205000014 ER PT J AU Das, SS Zhuang, JW Andrews, AP Greer, SC Guttman, CM Blair, W AF Das, SS Zhuang, JW Andrews, AP Greer, SC Guttman, CM Blair, W TI Living poly(alpha-methylstyrene) near the polymerization line. VII. Molecular weight distribution in a good solvent SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANIONIC-POLYMERIZATION; NEUTRON-SCATTERING; POLYMERS; EQUILIBRIUM; MICELLES; GROWTH; TETRAHYDROFURAN; AGGREGATION; TEMPERATURE; RELAXATION AB We have measured the molecular weight distribution (MWD) in a case of equilibrium polymerization. We have studied the time development of the MWD of "living" bifunctional poly(alpha-methylstyrene) in tetrahydrofuran after a quench to 21 K below the polymerization temperature, T-p. We see an intermediate Gaussian distribution evolving toward a final exponential distribution, as expected from theoretical considerations. We see a longer equilibration time for the number average molecular weight (M-n) as well as for the weight average molecular weight (M-w) than for the monomer concentration ([M)], whereas theories predict that M-n and [M] will relax together and that M-w will take much longer. We attribute the delayed equilibration and a second peak at about M-n/4 to the effects of ionic aggregation of the living polymers. We have also studied the equilibrium MWD of this system as a function of the temperature below T-p, and thus as a function of the number average degree of polymerization (L). These measurements and the time study discussed above are the first experimental evidence that the equilibrium MWD for an organic polymer in a state of equilibrium polymerization is an exponential/Flory-Schulz distribution, and is consistent with scaling predictions. Near T-p and at low L, we observe a deviation from the exponential distribution, which may be evidence of the effect of a chain-length dependence of the equilibrium constant for polymerization, or of the effects of polydispersity on correlations due to excluded volume. In addition, the measured L is about two times less than that expected from the initiator concentration; this could result from ionic aggregation or from chain transfer reactions. (C) 1999 American Institute of Physics. [S0021-9606(99)50844-1]. C1 Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Univ Maryland, Chem Phys Program, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RP Greer, SC (reprint author), Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. NR 73 TC 11 Z9 11 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 1999 VL 111 IS 20 BP 9406 EP 9417 DI 10.1063/1.480034 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 253PX UT WOS:000083565900037 ER PT J AU Dyer, SD Rochford, KB Rose, AH AF Dyer, SD Rochford, KB Rose, AH TI Fast and accurate low-coherence interferometric measurements of fiber Bragg grating dispersion and reflectance SO OPTICS EXPRESS LA English DT Article ID REFLECTOMETRY AB We demonstrate fast and accurate measurements of fiber Bragg grating dispersion and spectral reflectance using low-coherence interferometry. Both dispersion and spectral reflectance are obtained in less than 60 seconds, rendering the results immune to errors caused by temperature variations and instrumental drift. To examine the accuracy of the low-coherence technique, we compare the results with independent measurements and demonstrate an agreement better than 1.5 ps for dispersion and 25 pm for spectral reflectance wavelength. This manuscript describes work of the US Government and therefore is not subject to copyright. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Dyer, SD (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. NR 8 TC 23 Z9 23 U1 0 U2 4 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 22 PY 1999 VL 5 IS 11 BP 262 EP 266 PG 5 WC Optics SC Optics GA 258RJ UT WOS:000083852300003 PM 19401730 ER PT J AU Vasiliu-Doloc, L Rosenkranz, S Osborn, R Sinha, SK Lynn, JW Mesot, J Seeck, OH Preosti, G Fedro, AJ Mitchell, JF AF Vasiliu-Doloc, L Rosenkranz, S Osborn, R Sinha, SK Lynn, JW Mesot, J Seeck, OH Preosti, G Fedro, AJ Mitchell, JF TI Charge melting and polaron collapse in La1.2Sr1.8Mn2O7 SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-SCATTERING; MAGNETORESISTANCE; LA1-XSRXMNO3; DISTORTION; STRIPES AB X-ray and neutron scattering measurements directly demonstrate the existence of polarons in the paramagnetic phase of optimally doped colossal magnetoresistive oxides. The polarons exhibit short-range correlations that grow with decreasing temperature, but disappear abruptly at the ferromagnetic transition because of the sudden charge delocalization. The "melting" of the charge ordering as we cool through T-C occurs with the collapse of the quasistatic polaron scattering, and provides important new insights into the relation of polarons to colossal magnetoresistance. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Vasiliu-Doloc, L (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. RI Osborn, Raymond/E-8676-2011; Rosenkranz, Stephan/E-4672-2011 OI Osborn, Raymond/0000-0001-9565-3140; Rosenkranz, Stephan/0000-0002-5659-0383 NR 23 TC 144 Z9 144 U1 0 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 NOV 22 PY 1999 VL 83 IS 21 BP 4393 EP 4396 DI 10.1103/PhysRevLett.83.4393 PG 4 WC Physics, Multidisciplinary SC Physics GA 256UV UT WOS:000083745600043 ER PT J AU Fontaine, NH Young, M AF Fontaine, NH Young, M TI Two-dimensional index profiling of fibers and waveguides SO APPLIED OPTICS LA English DT Article ID REFRACTIVE-INDEX AB We have constructed a two-dimensional refracted-ray scanner that can resolve index-of-refraction increments of approximately 4 x 10(-5). This resolution is an order of magnitude finer than the uncertainty of the measurement. The scanner can be adapted to evaluate either fibers or planar waveguides. The two-dimensional scan and the high precision allow visualization of features, such as deposition layers, that are difficult if not impossible to see in conventional one-dimensional scans. OCIS codes: 060.0060, 130.0130, 060.2300, 060.2430. C1 PK Technol, Beaverton, OR 97005 USA. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. RP Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. EM myoung@mines.edu NR 11 TC 21 Z9 21 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 1999 VL 38 IS 33 BP 6836 EP 6844 DI 10.1364/AO.38.006836 PG 9 WC Optics SC Optics GA 256UC UT WOS:000083743900006 PM 18324224 ER PT J AU Peters, PM Funk, DS Peskin, AP Veasey, DL Sanford, NA Houde-Walter, SN Hayden, JS AF Peters, PM Funk, DS Peskin, AP Veasey, DL Sanford, NA Houde-Walter, SN Hayden, JS TI Ion-exchanged waveguide lasers in Er3+/Yb3+ codoped silicate glass SO APPLIED OPTICS LA English DT Article ID WAVE-GUIDE LASER; PHOSPHATE-GLASS; FIBER AMPLIFIERS; ER AB We investigated an Er3+/Yb3+ codoped silicate glass as a host material for waveguide lasers operating near 1.5 mu m. Spectroscopic properties of the glass are reported. Waveguide lasers were fabricated by K+-ion exchange from a nitrate melt. The waveguides support a single transverse mode at 1.5 mu m An investigation of the laser performance asa function of the Yb:Er ratio was performed, indicating an optimal ratio of approximately 5:1. Slope efficiencies of as great as 6.5% and output powers as high as 19.6 mW at 1.54 mu m were realized. The experimental results are compared with a waveguide laser model that is used to extract the Er3+ upconversion coefficients and the Yb3+-Er3+ cross-relaxation coefficients. The results indicate the possibility of obtaining high-performance waveguide lasers from a durable silicate host glass. OCIS codes: 140.3500, 130.2790, 130.3120, 160.2750, 160.5690. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. Natl Inst Stand & Technol, High Performance Syst & Serv Div, Boulder, CO 80303 USA. Univ Rochester, Inst Opt, Rochester, NY 14627 USA. Schott Glass Technol Inc, Res & Dev Mat Grp, Duryea, PA 18642 USA. RP Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. EM ppeters@boulder.nist.gov NR 16 TC 41 Z9 42 U1 0 U2 3 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 1999 VL 38 IS 33 BP 6879 EP 6886 DI 10.1364/AO.38.006879 PG 8 WC Optics SC Optics GA 256UC UT WOS:000083743900012 PM 18324230 ER PT J AU Frehlich, R AF Frehlich, R TI Autonomous beam alignment for coherent Doppler lidar with multielement detectors SO APPLIED OPTICS LA English DT Article ID BACKSCATTER HETERODYNE LIDAR; SPECTRAL PEAK ESTIMATION; WEAK-SIGNAL REGIME; TO-NOISE RATIO; LASER-RADAR; ATMOSPHERIC-TURBULENCE; SOLID-STATE; PERFORMANCE EVALUATION; REFRACTIVE TURBULENCE; RECEIVING EFFICIENCY AB Autonomous beam alignment for coherent Doppler lidar requires accurate information about optical misalignment and optical aberrations. A multielement heterodyne detector provides the required information without a loss in overall system performance. The effects of statistical variations from the random backscattered field (speckle field) are determined with computer simulations for both groundbased operation with a fixed calibration target and for space-based operation with random target backscatter. (C) 1999 Optical Society of America OCIS codes: 010.3640, 280.0280, 280.3640, 030.1670, 030.6140. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Campus Box 216, Boulder, CO 80309 USA. EM rgf@cires.colorado.edu NR 59 TC 0 Z9 0 U1 0 U2 1 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 1999 VL 38 IS 33 BP 6927 EP 6941 DI 10.1364/AO.38.006927 PG 15 WC Optics SC Optics GA 256UC UT WOS:000083743900018 PM 18324236 ER PT J AU Nayfonov, A Dappen, W Hummer, DG Mihalas, D AF Nayfonov, A Dappen, W Hummer, DG Mihalas, D TI The MHD equation of state with post-Holtsmark microfield distributions SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; equation of state; MHD; stars : atmospheres ID LARKIN PARTITION-FUNCTION; STRONGLY COUPLED PLASMAS; STELLAR ENVELOPES; SOLAR OSCILLATIONS; OPAL; FREQUENCIES; QUANTITIES; MODEL AB The Mihalas-Hummer-Dappen (MHD) equation of state is a part of the Opacity Project (OP), where it mainly provides ionization equilibria and level populations of a large number of astrophysically relevant species. Its basic concept is the idea of perturbed atomic and ionic states. At high densities, when many-body effects become dominant, the concept of perturbed atoms loses its sense. For that reason, the MHD equation of state was originally restricted to the plasma of stellar envelopes, that is, to relatively moderate densities, which should not exceed rho < 10(-2) g cm(-3). However, helioseismological analysis has demonstrated that this restriction is much too conservative. The principal feature of the original Hummer & Mihalas paper is an expression for the destruction probability of a bound state (ground state or excited) of a species (atomic or ionic), linked to the mean electric microfield of the plasma. Hummer dr Mihalas assumed, for convenience, a simplified form of the Holtsmark microfield for randomly distributed ions. An improved MHD equation of state (Q-MHD) is introduced. It is based on a more realistic microfield distribution that includes plasma correlations. Comparison with an alternative post-Holtsmark formalism (APEX) is made, and good agreement is shown. There is a clear signature of the choice of the microfield distribution in the adiabatic index gamma(1), which makes it accessible to present-day helioseismological analysis. However, since these thermodynamic effects of the microfield distribution are quite small, it also follows that the approximations chosen in the original MHD equation of state were reasonable. A particular feature of the original MHD papers was an explicit list of the adopted free energy and its first- and second-order analytical derivatives. The corresponding Q-MHD quantities are given in the Appendix. C1 Univ So Calif, Dept Phys & Astron, Los Angeles, CA 90089 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Aarhus Univ, Inst Phys & Astron, Theoret Astrophys Ctr, DK-8000 Aarhus, Denmark. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Nayfonov, A (reprint author), Univ So Calif, Dept Phys & Astron, Los Angeles, CA 90089 USA. NR 43 TC 36 Z9 36 U1 1 U2 5 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 1999 VL 526 IS 1 BP 451 EP 464 DI 10.1086/307972 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258XA UT WOS:000083863900039 ER PT J AU Bagheri, S Zetlin, C Dios, R AF Bagheri, S Zetlin, C Dios, R TI Estimation of optical properties of nearshore water SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB Most of the existing satellite sensors lack the spectral capabilities to discriminate phytoplankton pigments in water bodies. New satellite sensors (i.e. SeaWIFS) and future sensors on board EOS with narrow bandwidths will provide fine spectral resolution necessary to distinguish optical properties of nearshore waters provided sea data are available. This will enable spaceborne water color sensors to discriminate bloom forming phytoplankton species. The objective was to develop a library of absorption spectra for the most common phytoplankton species found within the Hudson/Raritan Estuary and coastal waters of New Jersey. Both culture-grown and field samples of phytoplankton were concentrated and analyzed using chemical and spectrometric techniques. Using spectral derivative and polynomial regression analysis, it was possible to identify wavelengths that could be used to characterize the pigment compositions of phytoplankton species in the estuary. C1 New Jersey Inst Technol, Dept Civil & Environm Engn, Newark, NJ 07102 USA. NOAA, Sandy Hook Lab, Highlands, NJ 07732 USA. New Jersey Inst Technol, Dept Math, Newark, NJ 07102 USA. RP Bagheri, S (reprint author), New Jersey Inst Technol, Dept Civil & Environm Engn, Univ Hts, Newark, NJ 07102 USA. NR 8 TC 6 Z9 11 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1999 VL 20 IS 17 BP 3393 EP 3397 DI 10.1080/014311699211417 PG 5 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 247UN UT WOS:000083238900012 ER PT J AU Gutman, GG AF Gutman, GG TI On the monitoring of land surface temperatures with the NOAA/AVHRR: removing the effect of satellite orbit drift SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID HIGH-RESOLUTION RADIOMETER; INDEX AB To study the inter-annual variability of land surface temperature with NOAA Advanced Very High Resolution Radiometer (AVHRR) data, one must account for changes in the observed radiances due to changes in the observation time caused by satellite orbit drift (SOD). This study proposes a simple method to remove the SOD component from the AVHRR thermal IIR. Spurious trends in these data should be corrected for to prevent their misidentification as real trends in the Earth's climate system and to infer more reliable conclusions from the inter-annual land surface variability studies, such as monitoring droughts. The proposed correction requires information on the observation solar zenith angle and normalized difference vegetation index for the region of interest. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. RP Gutman, GG (reprint author), NOAA, NESDIS, ERA12, WWB 712,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 13 TC 41 Z9 41 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1999 VL 20 IS 17 BP 3407 EP 3413 DI 10.1080/014311699211435 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 247UN UT WOS:000083238900014 ER PT J AU Nakayama, M Maki, M Elvidge, CD Liew, SC AF Nakayama, M Maki, M Elvidge, CD Liew, SC TI Contextual algorithm adapted for NOAA-AVHRR fire detection in Indonesia SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID IDENTIFICATION AB widely cited contextual algorithm for fire pixel detection was applied to NOAA-AVHRR data of Indonesia acquired during the severe fire season of 1997. The contextual algorithm tended to underestimate the number of fire pixels. Many fire pixels which could be identified visually in AVHRR band 3 imagery were missing in the output of the contextual algorithm. Through experimentation with the data, the authors were able to developed two alterations to the original algorithm to enhance the accuracy of fire detection in the Indonesian context. The enhanced algorithm was made capable of detecting fire pixels that the original algorithm failed to identify. C1 Utsunomiya Univ, Fac Agr, Utsunomiya, Tochigi 3218505, Japan. NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. Natl Univ Singapore, Ctr Remote Imaging Sensing & Proc, Singapore 119260, Singapore. RP Nakayama, M (reprint author), Utsunomiya Univ, Fac Agr, 350 Mine Machi, Utsunomiya, Tochigi 3218505, Japan. RI Elvidge, Christopher/C-3012-2009; Liew, Soo Chin/C-9187-2011 OI Liew, Soo Chin/0000-0001-8342-4682 NR 14 TC 18 Z9 20 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1999 VL 20 IS 17 BP 3415 EP 3421 DI 10.1080/014311699211444 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 247UN UT WOS:000083238900015 ER PT J AU Apel, EC Calvert, JG Gilpin, TM Fehsenfeld, FC Parrish, DD Lonneman, WA AF Apel, EC Calvert, JG Gilpin, TM Fehsenfeld, FC Parrish, DD Lonneman, WA TI The Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 3 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; SOUTHERN OXIDANTS; CARBON-MONOXIDE; AIR; OZONE; ATLANTA; PHOTOCHEMISTRY; TERPENES; QUALITY; SAMPLES AB The Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE) was designed to evaluate current analytical methods used to determine mixing ratios of atmospheric nonmethane hydrocarbons (NMHCs), A series of planned experiments, or tasks, were implemented to test the analytical methods in a graduated fashion. Tasks 1 and 2 involved relatively simple standard gas mixtures prepared by the National Institute for Standards and Technology (NIST). Results are presented here for task 3 in which a complex mixture containing 60 commonly observed NMHCs at concentrations of 1-30 parts per billion by volume (ppbv) in nitrogen diluent gas was prepared and distributed for analysis to 29 participating laboratories throughout the world. Reference mixing ratios were determined jointly by scientists from the National Center for Atmospheric Research (NCAR) and from the U. S. Environmental Protection Agency (EPA). Participants were asked to identify and quantify the hydrocarbons present in the mixture and submit their results to NCAR-NOMHICE scientists. The results were encouraging overall. Some laboratories performed extremely well during this exercise whereas other laboratories experienced problems in either identification or quantification or both. It is evident from the comparison of the NCAR-NOMHICE results with both the EPA analysis and the top ii analyses in the study that very good agreement is achievable between laboratories for mixtures in this concentration range. Some of the largest analytical discrepancies were from laboratories that used in-house standards for their calibration and/or syringe sample injection techniques. A major conclusion from this study is that the use of high-quality gas phase standards, introduced into the measurement instrument in a similar manner to air samples, is an important prerequisite for an accurate analysis. C1 Natl Ctr Atmospher Res, Boulder, CO 80303 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. US EPA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. RP Apel, EC (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80303 USA. EM apel@ucar.edu; calvert@ucar.edu; fcf@aztec.al.bldrdoc.gov; parrish@al.noaa.gov RI Parrish, David/E-8957-2010; Fehsenfeld, Frederick/I-4876-2013 OI Parrish, David/0000-0001-6312-2724; NR 36 TC 41 Z9 41 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26069 EP 26086 DI 10.1029/1999JD900793 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200001 ER PT J AU Pougatchev, NS Sachse, GW Fuelberg, HE Rinsland, CP Chatfield, RB Connors, VS Jones, NB Notholt, J Novelli, PC Reichle, HG AF Pougatchev, NS Sachse, GW Fuelberg, HE Rinsland, CP Chatfield, RB Connors, VS Jones, NB Notholt, J Novelli, PC Reichle, HG TI Pacific Exploratory Mission-Tropics carbon monoxide measurements in historical context SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTH-ATLANTIC OCEAN; SPECTROSCOPIC MEASUREMENTS; KITT PEAK; TRACE-A; CHEMICAL CHARACTERISTICS; VERTICAL-DISTRIBUTION; EARTHS ATMOSPHERE; MIXING RATIOS; CO; HEMISPHERE AB The three-dimensional (3-D) distribution of carbon monoxide (CO) over the southern Pacific during the NASA Global Tropospheric Experiment Pacific Exploratory Mission-Tropics (PEM-T) (August-October 1996) has been analyzed in comparison to other CO measurements. The following data sets have been used in the study: National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostic Laboratory surface level sampling; Commonwealth Scientific and Industrial Research Organization aircraft measurements over Cape Grim, Tasmania; solar spectroscopic measurements at Lauder, New Zealand; and data from two spaceborne Measurement of Air Pollution From Satellite experiments. For the PEM-T mission back trajectories analysis and 3-D modeling of the CO transport have been performed. It has been demonstrated that CO measurements obtained by different in situ and remote techniques can be used to build the picture of the CO climatology over the large geographical area. The structure of the CO distribution over the western part of the southern Pacific during the austral spring is mainly controlled by emission from biomass burning in Australia and Africa and subsequent long-range transport. The prevailing westerly transport occurs in the middle and upper troposphere, whereas the marine boundary layer remains relatively clean and uniform. Barriers in the form of the Intertropical Convergence Zone and South Pacific Convergence Zone protect the equatorial area (equator to 10 degrees S) from direct impact of biomass burning plumes from north and southwest. Consistency between the measurements taken in different years and modeling results indicates that the observed feature is a stable phenomenon. Outside the equatorial area the CO vertical distribution has a broad distinctive maximum at the altitude range 5-8 km and latitudes between 20 degrees S and 30 degrees S. This maximum is a stable feature, and its location indicates the area where the most intensive westerly transport occurs. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Natl Inst Water & Atmospher Res, Central Otago, New Zealand. Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. NOAA, CMDL, Boulder, CO 80303 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Pougatchev, NS (reprint author), NASA, Langley Res Ctr, MS 472, Hampton, VA 23681 USA. EM n.s.pougatchev@larc.nasa.gov; rinsland@mipsbox.larc.nasa.gov; chatfield@clio.arc.nasa.gov; vickie@stormy.larc.nasa.gov; jones@kea.lauder.cri.nz; jnotholt@awi-potsdam.de; pnovelli@cmdl.noaa.gov; henry_reichle@ncsu.edu RI Jones, Nicholas/G-5575-2011; Notholt, Justus/P-4520-2016 OI Jones, Nicholas/0000-0002-0111-2368; Notholt, Justus/0000-0002-3324-885X NR 58 TC 11 Z9 11 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 NOV 20 PY 1999 VL 104 IS D21 BP 26195 EP 26207 DI 10.1029/1999JD900465 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200010 ER PT J AU Levy, H Moxim, WJ Klonecki, AA Kasibhatla, PS AF Levy, H Moxim, WJ Klonecki, AA Kasibhatla, PS TI Simulated tropospheric NOx: Its evaluation, global distribution and individual source contributions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID GENERAL-CIRCULATION MODEL; OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; CHEMICAL-TRANSPORT MODEL; BIOMASS-BURNING EMISSIONS; CENTRAL NORTH PACIFIC; REACTIVE NITROGEN; PHOTOSTATIONARY STATE; OZONE PRODUCTION; COMBUSTION EMISSIONS; 3-DIMENSIONAL MODEL AB Using the 11-level Geophysical Fluid Dynamics Laboratory global chemical transport model, we simulate global tropospheric fields of NOx, peroxyacetyl nitrate (PAN), HNO3, and NOy, as well as the deposition of nitrate, extensively evaluate them against available observations from surface stations and aircraft missions, and quantify the contributions of individual natural and anthropogenic sources. The patterns and magnitudes of simulated and observed HNO3 wet deposition are generally in good agreement around the globe. Scatterplots of model simulations versus aircraft observations for NOx and NOy find similar to 50% of the points within +/-25%, find similar to 75% within +/-50%, and show no systematic global biases. Both simulated and observed vertical profiles have similar shapes with high levels (similar to 1 ppbv or greater) in the polluted boundary layer (BL), very low values in the remote BL, and values increasing from the middle to the upper troposphere. Simulated NOy, HNO3, and NOx + PAN are also in good agreement with extensive lower free tropospheric (FT) observations made at Mauna Loa Observatory. In general, the level of agreement between simulation and observation is as good as the agreement between separate, but simultaneous, observations of NO, NOx or NOy, As previous studies have shown, fossil fuel combustion and biomass burning control NOx levels in most of the lower half of the troposphere with a significant contribution from biogenic emissions. The exceptions are the remote low-NOx regions where BL and FT sources make comparable contributions. Unlike most previous studies, we find that the much smaller in situ FT sources generally dominate in the upper half of the troposphere. Lightning dominates in the tropics and summertime midlatitudes, and stratospheric injection is the major source in the summer high latitudes. The exception is transported emissions from fossil fuel combustion, which dominate in winter high latitudes. Though seldom dominant, aircraft emissions do have a significant impact on the upper troposphere and lower stratosphere of the northern hemisphere extratropics. C1 Princeton Univ, NOAA, GFDL, Princeton, NJ 08542 USA. Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. Natl Ctr Atmospher Res, Adv Studies Program, Boulder, CO 80307 USA. RP Levy, H (reprint author), Princeton Univ, NOAA, GFDL, POB 308, Princeton, NJ 08542 USA. EM hl@gfdl.gov RI Kasibhatla, Prasad/A-2574-2010 NR 125 TC 73 Z9 73 U1 2 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26279 EP 26306 DI 10.1029/1999JD900442 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200015 ER PT J AU Klassen, JK Lynton, J Golden, DM Williams, LR AF Klassen, JK Lynton, J Golden, DM Williams, LR TI Solubility of acetone in low-temperature (210-240 K) sulfuric acid solutions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UPPER TROPOSPHERE; LOWER STRATOSPHERE; HBR; COEFFICIENTS; HYDROCARBONS; MODEL AB The solubility of acetone in low-temperature sulfuric acid solutions was studied in a low-pressure Knudsen cell reactor. The time dependence of the uptake coefficient was analyzed to give effective Henry's law coefficients for acetone in 48 - 68 wt % sulfuric acid solutions between 210 and 240 K. The measured solubilities suggest that very little acetone will be partitioned into sulfate aerosol particles in the upper troposphere. Addition of ammonium sulfate to the sulfuric acid reduced the solubility slightly. No evidence was observed for reaction of dissolved acetone with itself or with nitric acid under the conditions of these experiments. C1 SRI Int, Menlo Pk, CA 94025 USA. RP Klassen, JK (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8380, Gaithersburg, MD 20899 USA. EM jane.klassen@nist.gov; golden@sri.com; lrwilliams@mediaone.net NR 26 TC 28 Z9 28 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26355 EP 26361 DI 10.1029/1999JD900751 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200019 ER PT J AU Logan, JA Megretskaia, IA Miller, AJ Tiao, GC Choi, D Zhang, L Stolarski, RS Labow, GJ Hollandsworth, SM Bodeker, GE Claude, H De Muer, D Kerr, JB Tarasick, DW Oltmans, SJ Johnson, B Schmidlin, F Staehelin, J Viatte, P Uchino, O AF Logan, JA Megretskaia, IA Miller, AJ Tiao, GC Choi, D Zhang, L Stolarski, RS Labow, GJ Hollandsworth, SM Bodeker, GE Claude, H De Muer, D Kerr, JB Tarasick, DW Oltmans, SJ Johnson, B Schmidlin, F Staehelin, J Viatte, P Uchino, O TI Trends in the vertical distribution of ozone: A comparison of two analyses of ozonesonde data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE; TROPOSPHERE; CANADA AB We present the results of two independent analyses of trends in the vertical distribution of ozone. For most of the ozonesonde stations we use data that were recently reevaluated and reprocessed to improve their quality and internal consistency. The two analyses give similar results for trends in ozone. We attribute differences in results primarily to differences in data selection criteria, rather than in statistical trend models. We find significant decreases in stratospheric ozone at all stations in middle and high latitudes of the Northern Hemisphere from 1970 to 1996, with the largest decreases located between 12 and 2i km, and trends of -3 to -10 %/decade near 17 km. The decreases are largest at the Canadian and the most northerly Japanese station and are smallest at the European stations and at Wallops Island. The mean midlatitude trend is largest, -7 %/decade, from 12 to 18 km for 1970-1996, and the decrease in ozone is significant from 10.5 to 25 km. For 1980-1996, the decrease is more negative by 1-2 %/decade, with a maximum trend of -9%/decade in the lowermost stratosphere. The trends vary seasonally from about 10 to 17 km, with largest ozone decreases in winter and spring. Trends in tropospheric ozone are highly variable and depend on the region. There are decreases or zero trends at the Canadian stations for 1970-1996, and decreases of -2 to -8 %/decade for the mid-troposphere for 1980-1996; the three European stations show increases for 1970-1996, but trends are close to zero for two stations for 1980-1996 and positive for one; there are increases in ozone for the three Japanese stations for 1970-1996, but trends are either positive or zero for 1980-1996. The United States stations show zero or slightly negative trends in tropospheric ozone after 1980. It is not possible to define reliably a mean tropospheric ozone trend for northern midlatitudes, given the small number of stations and the large variability in trends. The integrated column trends derived from the sonde data are consistent with trends derived from both surface-based and satellite measurements of the ozone column. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Natl Inst Water & Atmospher Res, Central Otago, New Zealand. Univ Chicago, Grad Sch Business, Chicago, IL 60637 USA. Meteorol Observ Hohenpeissenberg, Deutsch Wetterdienst, D-82383 Hohenpeissenberg, Germany. Royal Meteorol Inst Belgium, B-1180 Brussels, Belgium. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Atmospher Environm Serv, Toronto, ON M3H 5T4, Canada. NOAA, Natl Weather Serv, Climate Predict Ctr, Washington, DC 20233 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. ETH Honggerberg, Inst Atmospher Sci, CH-8093 Zurich, Switzerland. Japan Meteorol Agcy, Div Atmospher Environm, Chiyoda Ku, Tokyo 1008122, Japan. Swiss Meteorol Inst, Aerol Stn, CH-1530 Payerne, Switzerland. Raytheon STX, Lanham, MD USA. RP Logan, JA (reprint author), Harvard Univ, Dept Earth & Planetary Sci, 29 Oxford St, Cambridge, MA 02138 USA. RI Bodeker, Greg/A-8870-2008; Stolarski, Richard/B-8499-2013; OI Bodeker, Greg/0000-0003-1094-5852; Stolarski, Richard/0000-0001-8722-4012; Tarasick, David/0000-0001-9869-0692 NR 33 TC 143 Z9 148 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26373 EP 26399 DI 10.1029/1999JD900300 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200021 ER PT J AU Hood, LL Zhou, S AF Hood, LL Zhou, S TI Stratospheric effects of 27-day solar ultraviolet variations: The column ozone response and comparisons of solar cycles 21 and 22 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SHORT-TERM; LONG-TERM; TEMPERATURE RESPONSES; MIDDLE ATMOSPHERE; NORTHERN-HEMISPHERE; NIMBUS-7 SBUV; VARIABILITY; MODEL; CIRCULATION; IRRADIANCE AB Two unresolved observational issues concerning the response of stratospheric ozone to 27-day solar ultraviolet variations are as follows: (1) the amplitude of the column ozone response and whether it is consistent with the predictions of current two-dimensional stratospheric models and (2) whether the ozone profile response in the upper stratosphere differed appreciably during the solar cycle 22 maximum period (around 1990) as compared with the solar cycle 21 maximum period (around 1980). To investigate these issues, two separate 4-year intervals (1979 - 1982 and 1989 - 1992) of daily zonal mean Nimbus 7 Total Ozone Mapping Spectrometer, Nimbus 7 solar backscattered ultraviolet (SBUV), and/or NOAA 11 SBUV/2 data for tropical latitudes (300S to 300N) are analyzed using cross correlation and cross-spectral and regression methods. The Mg II core-to-wing ratio is employed as a measure of solar UV variations near 200 nm. Results show that the mean tropical column ozone sensitivity (percent change of ozone for a 1% change in solar flux) is 0.09 +/- 0.01 at a lag of 4-6 days during both intervals and is approximately consistent with model predictions. Ozone profile sensitivities and phase lags are also in agreement between the two 4-year intervals when statistical uncertainties and differences in data processing algorithms are considered. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NOAA, NCEP, Camp Springs, MD 20233 USA. RP Hood, LL (reprint author), Univ Arizona, Lunar & Planetary Lab, Kuiper Space Sci Bldg,1629 E Univ Blvd, Tucson, AZ 85721 USA. EM lon@1pl.arizona.edu; wd53sz@sun1.wwb.noao.gov NR 29 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26473 EP 26479 DI 10.1029/1999JD900466 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200026 ER PT J AU Newman, PA Fahey, DW Brune, WH Kurylo, MJ AF Newman, PA Fahey, DW Brune, WH Kurylo, MJ TI Including special sections - Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) CACGP/IGAC 1998 Symposium (CACGP/IGAC) - Preface SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID TROPOSPHERE EXCHANGE PROJECT; DIODE-LASER SPECTROMETER; LOWER STRATOSPHERE; NASA ER-2; TROPICAL TROPOPAUSE; MODEL-CALCULATIONS; AIRCRAFT; N2O; INSTRUMENT; PARTICLES C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. NOAA, Aeron Lab, Boulder, CO USA. Penn State Univ, Dept Meteorol, University Pk, PA USA. NIST, Gaithersburg, MD USA. NASA, Washington, DC USA. RP Newman, PA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RI Newman, Paul/D-6208-2012; Kurylo, Michael/H-2201-2012; Fahey, David/G-4499-2013 OI Newman, Paul/0000-0003-1139-2508; Fahey, David/0000-0003-1720-0634 NR 101 TC 29 Z9 29 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26481 EP 26496 DI 10.1029/1999JD900832 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200027 ER PT J AU Rosenlof, KH AF Rosenlof, KH TI Estimates of the seasonal cycle of mass and ozone transport at high northern latitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERALIZED ELIASSEN-PALM; LOWER STRATOSPHERE; DOWNWARD CONTROL; TROPOSPHERE; ER-2; SPECTROMETER; ATMOSPHERE; EXCHANGE; AIRCRAFT; WAVES AB Zonally averaged transport of mass and ozone into high northern latitudes exhibits a pronounced annual cycle. During summer, downwelling is at a minimum, and horizontal bulk advection and eddy fluxes of ozone and mass are found to be significant. This study examines in detail the ozone budget between 58 and 67 kPa in a meridional annulus ranging from 60 degrees to 70 degrees N during summer. The area of the study was chosen to correspond with the Photochemistry of Ozone Loss in the Arctic Region in Summer high-altitude aircraft experiment based in Fairbanks, Alaska, from April to September, 1997. It is found that the seasonal cycle in transport is an important contributor to the resultant seasonal march of ozone at high latitudes. The horizontal eddy contribution to the ozone tendency at high latitudes in the lower stratosphere is found to be large and negative (reducing ozone) during middle and late summer, where it more than offsets the increasing ozone tendency due to advection by the residual circulation. During early summer, the high-latitude air mass appears to be relatively isolated, with in situ chemical processes driving the ozone tendency. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Rosenlof, KH (reprint author), NOAA, Aeron Lab, Mail Stop R-E-AL6,325 Broadway, Boulder, CO 80303 USA. RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 43 TC 9 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26511 EP 26523 DI 10.1029/1999JD900329 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200029 ER PT J AU Ray, EA Moore, FL Elkins, JW Dutton, GS Fahey, DW Vomel, H Oltmans, SJ Rosenlof, KH AF Ray, EA Moore, FL Elkins, JW Dutton, GS Fahey, DW Vomel, H Oltmans, SJ Rosenlof, KH TI Transport into the Northern Hemisphere lowermost stratosphere revealed by in situ tracer measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INTERHEMISPHERIC EXCHANGE; TROPOSPHERE EXCHANGE; SULFUR-HEXAFLUORIDE; HADLEY CIRCULATION; CARBON-DIOXIDE; TROPOPAUSE; EMISSIONS; OZONE; CO2; LIFETIMES AB The Lightweight Airborne Chromatograph Experiment (LACE) has made in situ measurements of several long-lived trace gases in the upper troposphere and lower to middle stratosphere as part of the Observations of the Middle Stratosphere (OMS) balloon program. The tracers measured by LACE include several photolytic species (CFC-11, CFC-12, and halon-1211) as well as SF6. LACE measurements of these long-lived tracers as well as nearly simultaneous measurements of water vapor and CO2 are used to investigate transport into the lowermost stratosphere, a region where few in situ measurements exist. The measured photolytic species and water vapor are used in a simple mass balance calculation to estimate the mixture of tropospheric and overworld (theta > 380 K) air in the lowermost stratosphere. In the northern midlatitudes during September 1996, most of the air in the lowermost stratosphere sampled at the flight location (34.5 degrees N) was transported quasi-isentropically from the troposphere. Measurements from both a May 1998 midlatitude flight and a June 1997 high-latitude flight (64.5 degrees N) revealed the air sampled in the lowermost stratosphere to be dominated by downward advection from the overworld. Atmospheric SF6 and CO2 can uniquely reveal timescales and spatial scales of transport due to these species' large growth rates and subsequent latitudinal surface and free tropospheric gradients. Measurements in the lowermost stratosphere from the September northern midlatitude flight coupled with surface measurements of these species revealed a transport timescale of no more than 1.5 months from the surface to the lowermost stratosphere. The SF6 and CO2 mixing ratios were also consistent with mostly Northern Hemisphere tropospheric air in the lowermost stratosphere. These results point out the usefulness of high-resolution in situ measurements of long-lived tracers to help determine timescales and spatial scales of transport in the region of the upper troposphere and lowermost stratosphere. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ray, EA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. EM eray@cmdl.noaa.gov RI Ray, Eric/D-5941-2013; Rosenlof, Karen/B-5652-2008; Fahey, David/G-4499-2013 OI Ray, Eric/0000-0001-8727-9849; Rosenlof, Karen/0000-0002-0903-8270; Fahey, David/0000-0003-1720-0634 NR 38 TC 100 Z9 101 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26565 EP 26580 DI 10.1029/1999JD900323 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200032 ER PT J AU Fairlie, TD Pierce, RB Al-Saadi, JA Grose, WL Russell, JM Proffitt, MH Webster, CR AF Fairlie, TD Pierce, RB Al-Saadi, JA Grose, WL Russell, JM Proffitt, MH Webster, CR TI The contribution of mixing in Lagrangian photochemical predictions of polar ozone loss over the Arctic in summer 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VORTEX; CONSTITUENTS; STRATOSPHERE; ADVECTION; TRANSPORT; AIRCRAFT; MODEL; FLOW AB Measurements from the Halogen Occultation Experiment, together with assimilated winds, temperatures, and diabatic heating rates from the NASA Goddard data assimilation office, are used in the NASA Langley Research Center trajectory-photochemical model to compute photochemistry along three-dimensional air parcel trajectories for the Northern Hemisphere for the period March through September 1997. These calculations provide a global perspective for the interpretation of constituent measurements made fram the ER-2 platform during the Photochemistry of Ozone Loss in the Arctic Region in Summer aircraft campaign. An important component of the model is a parameterization of sub-grid-scale diffusive mixing. The parameterization uses an "n-member mixing" approach which includes an efficiency factor that enhances the mixing in regions where strain dominates the large-scale flow. Model predictions of O-3 and CH4 are compared with in situ measurements made from the ER-2. Comparison of the in situ data with model predictions, conducted with and without diffusive mixing, illustrates the contribution that irreversible mixing makes in establishing observed tracer-tracer correlations. Comparisons made for an ER-2 flight in late April 1997 show that irreversible mixing was important in establishing observed tracer-tracer correlations during spring 1997. Comparisons made in late June 1997, when filaments of very low N2O and CH4 were observed, indicate that remnants of air from the polar vortex survived unmixed in the low stratosphere 6 weeks after the breakup of the polar vortex in May. The results demonstrate that the sub-grid-scale mixing parameterization used in the model is effective not only for strong mixing conditions in late winter and early spring, but also for relatively weak mixing conditions that prevail in summer. C1 Sci & Technol Corp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fairlie, TD (reprint author), NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM t.d.fairlie@larc.nasa.gov; r.b.pierce@larc.nasa.gov; j.a.alsaadi@larc.nasa.gov; w.l.grose@larc.nasa.gov; jmr@cas.hamptonu.edu; proffitt@al.noaa.gov; cwebster@alpha1.jpl.nasa.gov RI Pierce, Robert Bradley/F-5609-2010 OI Pierce, Robert Bradley/0000-0002-2767-1643 NR 25 TC 26 Z9 26 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 NOV 20 PY 1999 VL 104 IS D21 BP 26597 EP 26609 DI 10.1029/1999JD900111 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200034 ER PT J AU Rex, M Salawitch, RJ Toon, GC Sen, B Margitan, JJ Osterman, GB Blavier, JF Gao, RS Donnelly, S Keim, E Neuman, J Fahey, DW Webster, CR Scott, DC Herman, RL May, RD Moyer, EJ Gunson, MR Irion, FW Chang, AY Rinsland, CP Bui, TP AF Rex, M Salawitch, RJ Toon, GC Sen, B Margitan, JJ Osterman, GB Blavier, JF Gao, RS Donnelly, S Keim, E Neuman, J Fahey, DW Webster, CR Scott, DC Herman, RL May, RD Moyer, EJ Gunson, MR Irion, FW Chang, AY Rinsland, CP Bui, TP TI Subsidence, mixing, and denitrification of Arctic polar vortex air measured During POLARIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MICROWAVE LIMB SOUNDER; OZONE DEPLETION; REACTIVE NITROGEN; STRATOSPHERIC CLOUD; ER-2 AIRCRAFT; WINTER; HNO3; N2O; ATMOS; CH4 AB We determine the degree of denitrification that occurred during the 1996-1997 Arctic winter using a technique that is based on balloon and aircraft borne measurements of NOy, N2O, and CH4. The NOy/N2O relation can undergo significant change due to isentropic mixing of subsided vortex air masses with extravortex air due to the high nonlinearity of the relation. These transport related reductions in NOy can be difficult to distinguish from the effects of denitrification caused by sedimentation of condensed HNO3. In this study, high-altitude balloon measurements are used to define the properties of air masses that later descend in the polar vortex to altitudes sampled by the ER-2 aircraft (i.e., similar to 20 km) and mix isentropically with extravortex air. Observed correlations of CH4 and N2O are used to quantify the degree of subsidence and mixing for individual air masses. on the basis of these results the expected mixing ratio of NOy resulting from subsidence and mixing, defined here as NOy**, is calculated and compared with the measured mixing ratio of NOy. Values of NOy and NOy** agree well during most parts of the flights. A slight deficit of NOy versus NOy** is found only for a limited region during the ER-2 flight on April 26, 1997. This deficit is interpreted as indication for weak denitrification (similar to 2-3 ppbv) in that air mass. The small degree of denitrification is consistent with the general synoptic-scale temperature history of the sampled air masses, which did not encounter temperatures below the frostpoint and had relatively brief encounters with temperatures below the nitric acid trihydrate equilibrium temperature. Much larger degrees of denitrification would have been inferred if mixing effects had been ignored, which is the traditional approach to diagnose denitrification. Our analysis emphasizes the importance of using other correlations of conserved species to be able to accurately interpret changes in the NOy/N2O relation with respect to denitrification. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Rex, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Neuman, Andy/A-1393-2009; Rex, Markus/A-6054-2009; Salawitch, Ross/B-4605-2009; Herman, Robert/H-9389-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Neuman, Andy/0000-0002-3986-1727; Rex, Markus/0000-0001-7847-8221; Salawitch, Ross/0000-0001-8597-5832; Herman, Robert/0000-0001-7063-6424; Fahey, David/0000-0003-1720-0634 NR 46 TC 42 Z9 41 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 NOV 20 PY 1999 VL 104 IS D21 BP 26611 EP 26623 DI 10.1029/1999JD900463 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200035 ER PT J AU Flocke, F Herman, RL Salawitch, RJ Atlas, E Webster, CR Schauffler, SM Lueb, RA May, RD Moyer, EJ Rosenlof, KH Scott, DC Blake, DR Bui, TP AF Flocke, F Herman, RL Salawitch, RJ Atlas, E Webster, CR Schauffler, SM Lueb, RA May, RD Moyer, EJ Rosenlof, KH Scott, DC Blake, DR Bui, TP TI An examination of chemistry and transport processes in the tropical lower stratosphere using observations of long-lived and short-lived compounds obtained during STRAT and POLARIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IN-SITU MEASUREMENTS; UPPER TROPOSPHERE; OZONE DEPLETION; N2O; CH4; AIRCRAFT; ABSORPTION; CHLORINE; RADICALS; CIRCULATION AB A suite of compounds with a wide range of photochemical lifetimes (3 months to several decades) was measured in the tropical and midlatitude upper troposphere and lower stratosphere during the Stratospheric Tracers of Atmospheric Transport (STRAT) experiment (fall 1995 and winter, summer, and fall 1996) and the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) deployment in late summer 1997. These species include various chlorofluorocarbons, hydrocarbons, halocarbons, and halons measured in whole air samples and CO measured in situ by tunable diode laser spectroscopy. Mixing ratio profiles of long-lived species in the tropical lower stratosphere are examined using a one-dimensional (1-D) photochemical model that includes entrainment from the extratropical stratosphere and is constrained by measured concentrations of OH. Profiles of tracers found using the 1-D model agree well with all the observed tropical profiles for an entrainment time scale of 85(-4)(+6) months, independent of altitude between potential temperatures of 370 and 500 K. The tropical profile of CO is used to show that the annually averaged ascent rate profile, on the basis of a set of radiative heating calculations, is accurate to approximately +/-44%, a smaller uncertainty than found by considering the uncertainties in the radiative model and its inputs. Tropical profiles of ethane and C2Cl4 reveal that the concentration of C1 is higher than expected on the basis of photochemical model simulations using standard gas phase kinetics and established relationships between total inorganic chlorine and CFC-11. Our observations suggest that short-lived organic chlorinated compounds and HCl carried across the tropical tropopause may provide an important source of inorganic chlorine to the tropical lower stratosphere that has been largely unappreciated in previous studies. The entrainment timescale found here is considerably less than the value found by a similar study that focused on observations obtained in the lower stratosphere during 1994. Several possible explanations for this difference are discussed. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Flocke, F (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM ffl@ucar.edu RI Salawitch, Ross/B-4605-2009; Herman, Robert/H-9389-2012; Rosenlof, Karen/B-5652-2008; Atlas, Elliot/J-8171-2015 OI Salawitch, Ross/0000-0001-8597-5832; Herman, Robert/0000-0001-7063-6424; Rosenlof, Karen/0000-0002-0903-8270; NR 74 TC 45 Z9 45 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26625 EP 26642 DI 10.1029/1999JD900504 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200036 ER PT J AU Romashkin, PA Hurst, DF Elkins, JW Dutton, GS Wamsley, PR AF Romashkin, PA Hurst, DF Elkins, JW Dutton, GS Wamsley, PR TI Effect of the tropospheric trend on the stratospheric tracer-tracer correlations: Methyl chloroform SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POLAR VORTEX AIR; BACKGROUND OBSERVATIONS; TRANSPORT; LIFETIMES; CH3CCL3 AB In situ measurements in the lower stratosphere in 1997 produced distinct intersecting correlations between methyl chloroform (CH3CCl3) and chlorofluorocarbon-11 (CFC-11) for air parcels sampled during spring and summer in the same physical space. The disagreement between spring and summer correlations in the stratosphere below 225 ppt of CFC-11 is in the opposite direction than is expected from the documented tropospheric trend of -15 ppt yr(-1). Summertime air parcels were enriched in CH3CCl3 compared to spring parcels. Mean ages based on sulfur hexafluoride (SF6) for CH3CCl3-rich air masses observed during summer were older by about a year than mean ages of CH3CCl3-depleted air parcels sampled during spring. The ages of stratospheric air masses and the documented history of methyl chloroform mixing ratios in the troposphere were used to normalize the stratospheric input of methyl chloroform, as if it had no tropospheric trend. The normalized correlations with and without parameterization for phyotoylic loss on the age distribution are more compact and revealed hidden anomalous mixing lines between polar vortex and midlatitude air. Higher mixing ratios of CH3CCl3, which the older air had at the time of the stratospheric entry, caused the summer correlation to be elevated on the tracer-tracer plot below 225 ppt of CFC-11. The ongoing tropospheric decrease of CH3CCl3 caused an inflection point and crossing of spring and summer correlations at 225 ppt of CFC-11. These results suggest that the tropospheric history is especially important for correlations of species that were increasing in the 1980s and are now decreasing (some CFCs, CCl4, and CH3CCl3). Distinct correlations between CH3CCl3 and CFC-11 observed for spring and summer 1997 measurements are the result of the 1991 tropospheric maximum of CH3CCl3 [Prinn et al., 1995] that has propagated into the stratosphere, where air parcels with high CH3CCl3 were sampled at 20 km altitude and 60 degrees-90 degrees N. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Romashkin, PA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80303 USA. EM promashkin@cmdl.noaa.gov RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 30 TC 6 Z9 6 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 NOV 20 PY 1999 VL 104 IS D21 BP 26643 EP 26652 DI 10.1029/1999JD900744 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200037 ER PT J AU Sen, B Osterman, GB Salawitch, RJ Toon, GC Margitan, JJ Blavier, JF Chang, AY May, RD Webster, CR Stimpfle, RM Bonne, GP Voss, PB Perkins, KK Anderson, JG Cohen, RC Elkins, JW Dutton, GS Hurst, DF Romashkin, PA Atlas, EL Schauffler, SM Loewenstein, M AF Sen, B Osterman, GB Salawitch, RJ Toon, GC Margitan, JJ Blavier, JF Chang, AY May, RD Webster, CR Stimpfle, RM Bonne, GP Voss, PB Perkins, KK Anderson, JG Cohen, RC Elkins, JW Dutton, GS Hurst, DF Romashkin, PA Atlas, EL Schauffler, SM Loewenstein, M TI The budget and partitioning of stratospheric chlorine during the 1997 Arctic summer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFATE AEROSOLS; ANTARCTIC OZONE; NITROUS-OXIDE; SULFURIC-ACID; ATMOS; ABSORPTION; AIRCRAFT; N2O; ABUNDANCE; DEPLETION AB Volume mixing ratio profiles of HCl, HOCl, ClNO3, CH3Cl, CFC-12, CFC-11, CCl4, HCFC-22, and CFC-113, were measured simultaneously from 9 to 38 km by the Jet Propulsion Laboratory MkIV Fourier Transform Infrared solar absorption spectrometer during two balloon flights from Fairbanks, Alaska (64.8 degrees N), on May 8 and July 8, 1997. The altitude variation of total organic chlorine (CCly), total inorganic chlorine (Cl-y), and the nearly constant value (3.7 +/- 0.2 ppbv) of their sum (Cl-TOT) demonstrates that the stratospheric chlorine species available to react with O-3 are supplied by the decomposition of organic chlorinated compounds whose abundances are well quantified. Measured profiles of HCL and ClNO3 agree well with profiles found by photochemical model (differences < 10% for altitudes below 35 km) constrained by various other constituents measured by MkIV. The production of HCl by ClO + OH plays a relatively small role in the partitioning of HCl and ClNO3 for the sampled air masses. However, better agreement with the measured profiles of HCl and ClNO3 is obtained when this source of HCl is included in the model. Both the measured and calculated [ClNO3]/[HCl] ratios exhibit the expected near linear variation with [O-3](2)/[CH4] over a broad range of altitudes. MkIV measurements of HCl, ClNO3, and CCly agree well with ER-2 in situ observations of these quantities for directly comparable air masses. These results demonstrate good understanding of the budget of stratospheric chlorine and that the partitioning of inorganic chlorine is accurately described by photochemical models that employ JPL97 reaction rates and production of HCl from ClO + OH for the environmental conditions encountered: relatively warm temperatures, long periods of solar illumination, and relatively low aerosol surface areas. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley, CA 94720 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sen, B (reprint author), CALTECH, Jet Prop Lab, MS 183-601, Pasadena, CA 91109 USA. EM bhaswar.sen@jpl.nasa.gov RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; Hurst, Dale/0000-0002-6315-2322 NR 44 TC 22 Z9 22 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 NOV 20 PY 1999 VL 104 IS D21 BP 26653 EP 26665 DI 10.1029/1999JD900245 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200038 ER PT J AU Del Negro, LA Fahey, DW Gao, RS Donnelly, SG Keim, ER Neuman, JA Cohen, RC Perkins, KK Koch, LC Salawitch, RJ Lloyd, SA Proffitt, MH Margitan, JJ Stimpfle, RM Bonne, GP Voss, PB Wennberg, PO McElroy, CT Swartz, WH Kusterer, TL Anderson, DE Lait, LR Bui, TP AF Del Negro, LA Fahey, DW Gao, RS Donnelly, SG Keim, ER Neuman, JA Cohen, RC Perkins, KK Koch, LC Salawitch, RJ Lloyd, SA Proffitt, MH Margitan, JJ Stimpfle, RM Bonne, GP Voss, PB Wennberg, PO McElroy, CT Swartz, WH Kusterer, TL Anderson, DE Lait, LR Bui, TP TI Comparison of modeled and observed values of NO2 and JNO(2) during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) mission SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IN-SITU MEASUREMENTS; LOWER STRATOSPHERE; ER-2 AIRCRAFT; REACTIVE NITROGEN; CHLORINE RADICALS; UPPER TROPOSPHERE; AMORPHOUS-CARBON; TEMPERATURE; O-3; ACTIVATION AB Stratospheric measurements of NO, NO2, O-3, ClO, and HO2 were made during spring, early summer, and late summer in the Arctic region during 1997 as part of the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) field campaign. In the sunlit atmosphere, NO2 and NO are in steady state through NO2 photolysis and reactions involving O-3, ClO, BrO, and HO2. By combining observations of O-3, ClO, and HO2, observed and modeled values of the NO2 photolysis rate coefficient ((NO2)-N-J), and model estimates of BrO, several comparisons are made between steady state and measured values of both NO2 and (NO2)-N-J An apparent seasonal dependence in discrepancies between calculated and measured values was found; however, a source for this dependence could not be identified. Overall, the mean linear fits in the various comparisons show agreement within 19%, well within the combined uncertainties (+/-50 to 70%). These results suggest that photochemistry controlling the NO2/NO abundance ratio is well represented throughout much of the sunlit lower stratosphere. A reduction in the uncertainty of laboratory determinations of the rate coefficient of NO + O-3 --> NO2 + O-2 would aid future analyses of these or similar atmospheric observations. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Aerosp Corp, Space & Environm Technol Ctr, Los Angeles, CA 90009 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Johns Hopkins Univ, Appl Phys Lab, Atomospher Remote Sensing Grp, Laurel, MD 20723 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Environm Canada, Atomospher Environm Serv, Downsview, ON M3H 5T4, Canada. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Del Negro, LA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, R-E-CG1,325 Broadway, Boulder, CO 80303 USA. EM ldelnegro@cmdl.noaa.gov RI Swartz, William/A-1965-2010; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013; Neuman, Andy/A-1393-2009; Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012 OI Swartz, William/0000-0002-9172-7189; Fahey, David/0000-0003-1720-0634; Neuman, Andy/0000-0002-3986-1727; Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; NR 40 TC 27 Z9 27 U1 1 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 NOV 20 PY 1999 VL 104 IS D21 BP 26687 EP 26703 DI 10.1029/1999JD900246 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200040 ER PT J AU Stimpfle, RM Cohen, RC Bonne, GP Voss, PB Perkins, KK Koch, LC Anderson, JG Salawitch, RJ Lloyd, SA Gao, RS Del Negro, LA Keim, ER Bui, TP AF Stimpfle, RM Cohen, RC Bonne, GP Voss, PB Perkins, KK Koch, LC Anderson, JG Salawitch, RJ Lloyd, SA Gao, RS Del Negro, LA Keim, ER Bui, TP TI The coupling of ClONO2, ClO, and NO2 in the lower stratosphere from in situ observations using the NASA ER-2 aircraft SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHLORINE NITRATE; HCL; ATMOSPHERE; SPECTROSCOPY; NITROGEN; GASES AB The first in situ measurements of ClONO2 in the lower stratosphere, acquired using the NASA ER-2 aircraft during the Polar Ozone Loss in the Arctic Region in Summer (POLARIS) mission, are combined with simultaneous measurements of ClO, NO2, temperature, pressure, and the calculated photolysis rate coefficient (J(CLONO2)) to examine the balance between production and loss of ClONO2. The observations demonstrate that the ClONO2 photochemical steady state approximation, [ClONO2](PSS) = k x [ClO] x [NO2] / J(ClONO2) is in good agreement with the direct measurement, [ClONO2](MEAS). For the bulk of the data (80%), where T > 220 K and latitudes > 45 degrees N, [ClONo2](PSS) = 1.15 +/- 0.36 (1 sigma) x [ClONO2](MEAS), while for T < 220 K and latitudes < 45 degrees N the result is somewhat less at 1.01 +/- 0.30. The cause of the temperature and/or latitude trend is unidentified. These results are independent of solar zenith angle and air density, thus there is no evidence in support of a pressure-dependent quantum yield for photodissociation of ClONO2 at wavelengths >300 nm. These measurements confirm the mechanism by which active nitrogen (NOx = NO + NO2) controls the abundance of active chlorine (Cl-x = ClO + Cl) in the stratosphere. C1 Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Colorado, Dept Chem, Boulder, CO 80302 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Stimpfle, RM (reprint author), Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. EM stimpfle@huarp.harvard.edu RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Gao, Ru-Shan/H-7455-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; NR 37 TC 29 Z9 29 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 NOV 20 PY 1999 VL 104 IS D21 BP 26705 EP 26714 DI 10.1029/1999JD900288 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200041 ER PT J AU Strawa, AW Drdla, K Ferry, GV Verma, S Pueschel, RF Yasuda, M Salawitch, RJ Gao, RS Howard, SD Bui, PT Loewenstein, M Elkins, JW Perkins, KK Cohen, R AF Strawa, AW Drdla, K Ferry, GV Verma, S Pueschel, RF Yasuda, M Salawitch, RJ Gao, RS Howard, SD Bui, PT Loewenstein, M Elkins, JW Perkins, KK Cohen, R TI Carbonaceous aerosol (Soot) measured in the lower stratosphere during POLARIS and its role in stratospheric photochemistry SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IN-SITU MEASUREMENTS; FRACTAL DIMENSION; UPPER TROPOSPHERE; AMORPHOUS-CARBON; BLACK CARBON; REACTION-KINETICS; OZONE DEPLETION; EXHAUST PLUMES; HEXANE SOOT; PARTICLES AB This paper describes recent measurements of carbonaceous aerosol made by wire impactors during the Photochemistry Ozone Loss in the Arctic Region in Summer (POLARIS) campaign and assesses their role in stratospheric photochemistry. Ninety-five percent of the carbonaceous aerosol collected during this campaign was in the form of b lack carbon aerosol (BCA), or soot. A new method of analyzing impactor samples is described that accounts for particle bounce and models the BCA as fractal aggregates to modify the aerodynamic collection efficiency and determine particle surface area. Results are compared to previously used methods. The new method results in an increase in the measured BCA number density of 4 times, surface area density of similar to 15 times, and an increase in mass loading of 6.15 times over one previously used approach, Average values of number, surface area, and mass densities are 0.06 no./cm(3), 0.03 mu m(2)/cm(3), and 0.64 ng/m(3), respectively. BCA number densities are similar to 1% of total aerosol number density, and BCA surface area density is similar to 10% of the measured sulfuric acid aerosol surface area. Including heterogeneous reactions on BCA in a photochemical model can affect photochemistry leading to renoxification and increased ozone depletion. However, these predicted effects are not supported by the POLARIS observations, in particular, the NOx/NOy ratios, The laboratory data is not conclusive enough to determine to what extent the heterogeneous reaction is catalytic or carbon consuming. Including catalytic reactions on BCA does not statistically improve the agreement between model and measurement in any of the several scenarios considered. Furthermore, if the reactions cause even partial carbon oxidation, the BCA would be consumed at a rate inconsistent with POLARIS observations. These inconsistencies lead us to conclude that the presence of BCA in the stratosphere did not affect stratospheric photochemistry during POLARIS. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Sci Syst & Applicat Inc, Moffett Field, CA USA. San Jose State Univ, San Jose, CA 95192 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Symtek, Moffett Field, CA USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Strawa, AW (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM astrawa@mail.arc.nasa.gov RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Gao, Ru-Shan/H-7455-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; NR 64 TC 34 Z9 35 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26753 EP 26766 DI 10.1029/1999JD900453 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200045 ER PT J AU Lloyd, S Swartz, WH Kusterer, T Anderson, D McElroy, CT Midwinter, C Hall, R Nassim, K Jaffe, D Simpson, W Kelley, J Nicks, D Griffin, D Johnson, B Evans, R Quincy, D Oltmans, S Newman, P McPeters, R Labow, G Moy, L Seftor, C Toon, G Sen, B Blavier, JF AF Lloyd, S Swartz, WH Kusterer, T Anderson, D McElroy, CT Midwinter, C Hall, R Nassim, K Jaffe, D Simpson, W Kelley, J Nicks, D Griffin, D Johnson, B Evans, R Quincy, D Oltmans, S Newman, P McPeters, R Labow, G Moy, L Seftor, C Toon, G Sen, B Blavier, JF TI Intercomparison of total ozone observations at Fairbanks, Alaska, during POLARIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID COLUMN AB The pattern of seasonal ozone loss over Fairbanks, Alaska (AK), during the NASA Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) campaign in the spring and summer of 1997 is defined. Five independent data sets of total ozone observations at Fairbanks are presented, from the Earth Probe and ADEOS Total Ozone Mapping Spectrometer (TOMS) satellite instruments, balloon-borne electrochemical concentration cell ozonesondes, and ground-based (Brewer spectroradiometer, Dobson spectrophotometer, and the Jet Propulsion Laboratory MkIV infrared interferometer) instruments. The excellent agreement between different observational techniques lends confidence to the observed rate of summertime loss of total ozone at high latitudes. In addition, the small offsets between the data sets are well understood. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Environm Canada, Atmospher Environm Serv, Downsview, ON, Canada. Univ Washington, Inst Geophys, Bothell, WA USA. Univ Alaska, Dept Chem, Fairbanks, AK 99775 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Raytheon Informat Technol & Sci Serv, Lanham, MD USA. Jet Propuls Lab, Pasadena, CA USA. RP Lloyd, S (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM Steven.Lloyd@jhuapl.edu RI Newman, Paul/D-6208-2012; Swartz, William/A-1965-2010; McPeters, Richard/G-4955-2013; Simpson, William/I-2859-2014 OI Newman, Paul/0000-0003-1139-2508; Swartz, William/0000-0002-9172-7189; McPeters, Richard/0000-0002-8926-8462; Simpson, William/0000-0002-8596-7290 NR 14 TC 8 Z9 8 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 NOV 20 PY 1999 VL 104 IS D21 BP 26767 EP 26778 DI 10.1029/1999JD900468 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200046 ER PT J AU Toon, GC Blavier, JF Sen, B Margitan, JJ Webster, CR May, RD Fahey, D Gao, R Del Negro, L Proffitt, M Elkins, J Romashkin, PA Hurst, DF Oltmans, S Atlas, E Schauffler, S Flocke, F Bui, TP Stimpfle, RM Bonne, GP Voss, PB Cohen, RC AF Toon, GC Blavier, JF Sen, B Margitan, JJ Webster, CR May, RD Fahey, D Gao, R Del Negro, L Proffitt, M Elkins, J Romashkin, PA Hurst, DF Oltmans, S Atlas, E Schauffler, S Flocke, F Bui, TP Stimpfle, RM Bonne, GP Voss, PB Cohen, RC TI Comparison of MkIV balloon and ER-2 aircraft measurements of atmospheric trace gases SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC MEASUREMENTS; INSTRUMENTS ABOARD; REACTIVE NITROGEN; ATMOS; OZONE; SPECTROMETER; WATER; OXIDE; N2O; CH4 AB On May 8, 1997, vertical profiles of over 30 different gases were measured remotely in solar occultation by the Jet Propulsion Laboratory MkIV Interferometer during a balloon flight launched from Fairbanks, Alaska. These gases included H2O, N2O, CH4, CO, NOx, NOy, HCl, ClNO3, CCl2F2, CCl3F, CCl4, CHClF2, CClF2CCl2F, SF6, CH3Cl, and C2H6, all of which were also measured in situ by instruments on board the NASA ER-2 aircraft, which was making flights from Fairbanks during this same early May time period as part of the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) experiment. A comparison of the gas volume mixing ratios in the upper troposphere and lower stratosphere reveals agreement better than 5% for most gases. The three significant exceptions to this are SF6 and CCl4 for which the remote measurements exceed the in situ observations by 15-20% at all altitudes, and H2O for which the remote measurements are up to 30% smaller than the in situ observations near the hygropause. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO USA. Natl Ocean & Atmospher Adm, Climate Monitoring & Diagnost Lab, Boulder, CO USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Toon, GC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM toon@mark4sun.jpl.nasa.gov RI Cohen, Ronald/A-8842-2011; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016; Fahey, David/G-4499-2013 OI Cohen, Ronald/0000-0001-6617-7691; Hurst, Dale/0000-0002-6315-2322; Fahey, David/0000-0003-1720-0634 NR 22 TC 79 Z9 79 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 NOV 20 PY 1999 VL 104 IS D21 BP 26779 EP 26790 DI 10.1029/1999JD900379 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200047 ER PT J AU Anderson, TL Covert, DS Wheeler, JD Harris, JM Perry, KD Trost, BE Jaffe, DJ Ogren, JA AF Anderson, TL Covert, DS Wheeler, JD Harris, JM Perry, KD Trost, BE Jaffe, DJ Ogren, JA TI Aerosol backscatter fraction and single scattering albedo: Measured values and uncertainties at a coastal station in the Pacific Northwest SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT Joint Symposium on Atmospheric Chemistry and Climate Change CY AUG 19-25, 1998 CL UNIV WASHINGTON, SEATTLE, WA SP Univ Washington Joint Inst Study Atmoshere & Ocean, NOAA Pacific Marine Environm Lab, European Commiss, US DOE, NASA, US Natl Sci Fdn, World Meteorol Org, Int Assoc Meteorol & Atmospher Sci, Commiss Atmospher Chem & Global Pollut, Int Global Atmospher Chem Project HO UNIV WASHINGTON ID CHARACTERIZATION EXPERIMENT ACE-1; ATTENUATION CROSS-SECTION; BLACK CARBON; LIGHT-ABSORPTION; TRANSPORT; SOOT; NEPHELOMETER; ENVIRONMENTS; ATMOSPHERE; SIZE AB Light scattering, hemispheric backscattering, and absorption properties of submicrometer and supermicrometer aerosol particles at low relative humidity and 550 nm wavelength are investigated as a function of air mass category during a 2-month campaign at a midlatitude Pacific coastal station at Cheeka Peak, Washington. The main source of uncertainty in single scattering albedo (omega) measurements, namely, the measurement of light absorption, is addressed by the deployment of three identical absorption photometers and by relying on a recent calibration of this device using direct optical measurements. The absorption photometer measurement is corrected for response to light scattering, and measurements of sea-salt aerosol in this campaign provide a partial validation of this correction. Scattering measurements by nephelometry are also corrected for known instrumental nonidealities. Uncertainties stemming from instrumental noise, drift, calibration, and correction factors are propagated to allow comparisons among air mass categories and with other data sets and, ultimately, to constrain the values of omega and other optical properties used in climate models. Marine aerosol over the midlatitude eastern Pacific is found to be weakly absorbing for the sub-mu m component and virtually nonabsorbing for the super-mu m component (separated at 1 mu m, low-relative humidity, aerodynamic diameter). A distinct increase in sub-mu m light extinction (especially absorption) observed during 2 days of sustained marine flow appears to be Asian pollution transported across the Pacific. Low levels of gaseous NOx during this period rule out nearby combustion sources, and low levels of particulate Fe, Al, and Si rule out a significant contribution from mineral dust. Excluding this episode, both scattering and absorption properties for marine sampling conditions are similar to those observed in the clean midlatitude Southern Hemisphere (Cape Grim, Tasmania), In general, continental influence, as indicated by trends over the air mass categories, tends to raise the backscatter ratio and lower omega. Light absorption values compared to previous marine and coastal measurements confirm the range of values found by others and the highly variable nature of this quantity. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Oregon State Univ, Corvallis, OR 97331 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Calif Davis, Crocker Nucl Lab, Davis, CA 95616 USA. Univ Alaska, Dept Geophys, Fairbanks, AK USA. Univ Washington, Bothell, WA USA. RP Anderson, TL (reprint author), Univ Washington, Joint Inst Study Atmosphere & Oceans, Box 351640, Seattle, WA 98195 USA. EM tadand@u.washington.edu RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 30 TC 100 Z9 100 U1 1 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1999 VL 104 IS D21 BP 26793 EP 26807 DI 10.1029/1999JD900172 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257KN UT WOS:000083781200049 ER PT J AU Sanov, A Faeder, J Parson, R Lineberger, WC AF Sanov, A Faeder, J Parson, R Lineberger, WC TI Spin-orbit coupling in I center dot CO2 and I center dot OCS van der Waals complexes: beyond the pseudo-diatomic approximation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; ELECTRONIC STATES; ENERGY-TRANSFER; CLUSTER IONS; ATOMS; PHOTODISSOCIATION; PHOTODETACHMENT; SPECTROSCOPY; HALIDES AB We investigate theoretically the electronic structure of I . CO2 and I . OCS van der Waals complexes including spin-orbit interaction. For the T-shaped geometry of I . CO2, we calculate the potentials using a fully polyatomic treatment and compare the results to the widely used pseudo-diatomic approximation. The latter becomes: increasingly invalid at I-CO2 distances shelter than 4 Angstrom. We calculate the potentials of linear I . SCO and I . OCS, and analyze the zero-order electronic structure of nonlinear I . OCS. We also discuss the validity of treating the spin-orbit interaction in I . CO2 and I . OCS as an atomic property of iodine and find this approximation justified at characteristic van der Weals distances. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Biochem & Chem, Boulder, CO 80309 USA. RP Lineberger, WC (reprint author), Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. NR 21 TC 20 Z9 20 U1 0 U2 6 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 19 PY 1999 VL 313 IS 5-6 BP 812 EP 819 DI 10.1016/S0009-2614(99)00893-3 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 261AJ UT WOS:000083985400013 ER PT J AU Bandyopadhyay, S Tarek, M Klein, ML AF Bandyopadhyay, S Tarek, M Klein, ML TI Molecular dynamics study of a lipid-DNA complex SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID COLUMNAR PHASE; FORCE-FIELDS; SIMULATION; MEMBRANES; MIXTURES; SODIUM; WATER AB Lipid-DNA complexes are of topical interest because of their potential for use as vectors in gene therapy. Herein, molecular dynamics simulations have been carried out to probe the nature of Lipid-DNA interactions and thereby provide a complement to recent experimental and theoretical studies. Specifically, we have investigated the DNA duplex d(CCAACGTTGG)(2), in its canonical B-form, intercalated into a lipid bilayer consisting of a neutralizing binary mixture of cationic (dimyristoyltrimethylammonium propane-DMTAP) and zwitterionic (dimyristoylphosphatidylcholine-DMPC) lipids. Surprisingly, both lipids are involved in neutralizing the anionic DNA phosphate groups. The electrostatic interactions between the cationic trimethylammonium (TAP) and zwitterionic phosphocholine (PC) headgroups of the two lipids allow the PC headgroups to orient out of the bilayer plane and thereby also become available to screen the negative charges on the DNA. C1 Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Klein, ML (reprint author), Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. NR 35 TC 85 Z9 88 U1 1 U2 11 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 18 PY 1999 VL 103 IS 46 BP 10075 EP 10080 DI 10.1021/jp9927496 PG 6 WC Chemistry, Physical SC Chemistry GA 260XJ UT WOS:000083978500001 ER PT J AU Choi, S Briber, RM Bauer, BJ Topp, A Gauthier, M Tichagwa, L AF Choi, S Briber, RM Bauer, BJ Topp, A Gauthier, M Tichagwa, L TI Small-angle neutron scattering of solutions of arborescent graft polystyrenes SO MACROMOLECULES LA English DT Article ID LINEAR POLYMER DIMENSION; REGULAR STAR POLYMERS; STARBURST DENDRIMERS; INTRINSIC-VISCOSITY; COLLAPSED REGIME; DENDRITIC MACROMOLECULES; CONCENTRATION-DEPENDENCE; THERMODYNAMIC PROPERTIES; TEMPERATURE-DEPENDENCE; TRANSITION AB Small-angle neutron scattering was used to measure the size and shape of arborescent graft polymers as a function of generation in solution. The radius of gyration of arborescent graft polymers was found to be almost independent of temperature in both deuterated cyclohexane (above the cloud point) and deuterated toluene. For dilute deuterated cyclohexane solutions the optically measured cloud point was found to be 15 +/- 1 degrees C. Two peaks were observed in the SANS data for the phase-separated (below the cloud point) deuterated cyclohexane solutions of the largest polymers (generation 3). The first peak (at smaller scattering vector) is attributed to the interference between molecules while the second peak arises from the single particle form factor which was also observed at temperatures above the cloud point. In deuterated cyclohexane the position of the form factor peak was constant at temperatures above 15 degrees C. In the phase-separated deuterated cyclohexane solutions the form factor peak shifted to higher q, indicating a fractional decrease in molecular diameter of about 15% upon phase separation. The spacing of the interference peak (at low q) in the phase-separated solutions was consistent with the molecules aggregating in clusters with little interpenetration of the molecules. A power law function was used to model the real space density profile from which scattering curves were calculated and compared to the experimental data. This power law functional form for the density profile gave fits with smaller deviations from the experimental data when compared to either a hard or hollow sphere model. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Waterloo, Dept Chem, Polymer Res Inst, Waterloo, ON N2L 3G1, Canada. RP Briber, RM (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 58 TC 20 Z9 20 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 16 PY 1999 VL 32 IS 23 BP 7879 EP 7886 DI 10.1021/ma990185y PG 8 WC Polymer Science SC Polymer Science GA 257HB UT WOS:000083775500022 ER PT J AU Yim, H Kent, M McNamara, WF Ivkov, R Satija, S Majewski, J AF Yim, H Kent, M McNamara, WF Ivkov, R Satija, S Majewski, J TI Structure within thin epoxy films revealed by solvent swelling: A neutron reflectivity study SO MACROMOLECULES LA English DT Article ID POLY(METHYL METHACRYLATE); POLYMER BLENDS; SPIN-CAST; INTERFACE SEGREGATION; END-GROUPS; SURFACE; POLY(DIMETHYLSILOXANE); NETWORKS; MICROSTRUCTURE; SPECTROSCOPY AB Structure within thin epoxy films is investigated by neutron reflectivity (NR) as a function of resin/cross-linker composition and cure temperature. Variation in the cross-link density normal to the substrate surface is examined by swelling the films with the good solvent d-nitrobenzene (d-NB). The principal observation is a large excess of d-NB near the air surface. This is not a wetting layer, but rather indicates a lower cross-link density in the near-surface region. This effect is due to preferential segregation of the cross-linker to the air surface, driven by the lower surface tension of the cross-linker relative to the epoxide oligomers. The magnitude of the effect is a function of composition and cure temperature. Exclusion of d-NB from the region immediately adjacent to the substrate surface is also observed, possibly indicating a tightly bound layer of epoxy. Regarding swelling in the bulk of the films, the behavior is nonsymmetric with departure from the stoichiometric ratio. The films deficient in curing agent show greater equilibrium swelling and faster swelling kinetics than the films with an excess of curing agent. C1 Sandia Natl Labs, Dept 1832, Albuquerque, NM 87185 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, LANCSE, Los Alamos, NM USA. RP Kent, M (reprint author), Sandia Natl Labs, Dept 1832, POB 5800, Albuquerque, NM 87185 USA. RI Lujan Center, LANL/G-4896-2012; Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 50 TC 34 Z9 34 U1 3 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 16 PY 1999 VL 32 IS 23 BP 7932 EP 7938 DI 10.1021/ma990990c PG 7 WC Polymer Science SC Polymer Science GA 257HB UT WOS:000083775500029 ER PT J AU Baker, J AF Baker, J TI NASA will operate Terra SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter C1 NOAA, Washington, DC 20233 USA. RP Baker, J (reprint author), NOAA, Washington, DC 20233 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD NOV 15 PY 1999 VL 151 IS 20 BP 10 EP 10 PG 1 WC Engineering, Aerospace SC Engineering GA 260EB UT WOS:000083935600007 ER PT J AU Bonsal, BR Lawford, RG AF Bonsal, BR Lawford, RG TI Teleconnections between El Nino and La Nina events and summer extended dry spells on the Canadian prairies SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE teleconnections; Canadian prairies; extended dry spells; El Nino; La Nina; PNA patterns; 500 hPa anomalies; North Pacific SST anomalies ID SEA-SURFACE TEMPERATURE; NORTH PACIFIC-OCEAN; CIRCULATION ANOMALIES; SOUTHERN OSCILLATION; AMERICAN DROUGHT; LINEAR-RESPONSE; SOIL-MOISTURE; VARIABILITY; CLIMATE; ATMOSPHERE AB Teleconnections among El Nino and La Nina events, North Pacific sea surface temperature anomalies, and summer (June, July, August) extended dry spells on the Canadian Prairies are documented and analysed. For the period 1948-1991, results show the majority of El Nino events associated with a persistent North Pacific SST anomaly pattern consisting of anomalously cold water in the east-central North Pacific and anomalously warm water along the west coast of North America. The average number of summer extended dry spells on the Prairies associated with El Nino events is significantly higher than for non-El Nino periods. This relationship occurs during the second summer following the mature stage of Ei Nino events. Further analysis reveals that La Nina events are associated with opposite North Pacific SST anomaly patterns that also tend to persist for several seasons. The average number of summer extended dry spells associated with these events is significantly lower than for non-La Nina periods. Even though the relationships among El Nino, La Nina, North Pacific SST anomalies, and extended dry spells show high variability, the results of this study may be considered as an initial step towards contributing to a long-range forecasting technique of summer extended dry spells on the Canadian Prairies. Copyright (C) 1999 Royal Meteorological Society. C1 Atmospher Environm Serv, Climate Res Branch, Downsview, ON M3H 5T4, Canada. NOAA, OGP, Silver Spring, MD 20910 USA. RP Bonsal, BR (reprint author), Atmospher Environm Serv, Climate Res Branch, Downsview, ON M3H 5T4, Canada. NR 37 TC 37 Z9 39 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV 15 PY 1999 VL 19 IS 13 BP 1445 EP 1458 DI 10.1002/(SICI)1097-0088(19991115)19:13<1445::AID-JOC431>3.3.CO;2-Z PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 256EE UT WOS:000083712300004 ER PT J AU Ukegawa, S Gallagher, A AF Ukegawa, S Gallagher, A TI A discharge lamp based on MgH radiation SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB We report the efficacy and spectrum of an inductively-coupled, radio-frequency discharge in mixtures of magnesium (Mg), hydrogen (H-2), and argon vapor. The predominantly green emission is dominated by the A-X band of MgH, plus some Mg lines. The discharge operates in a frit-sealed, similar to 600 degrees C alumina cell with a sapphire window, at pressures of 200-600 Pa. The plasma impedance is established from the impedance of the matching network parameters, and the electron temperature is determined from line intensity ratios. Assuming isotropic emission, a maximum energy efficiency (eta) of similar to 10% (efficacy similar to 90 lm per watt) is achieved, where eta is the ratio of visible emission to power delivered to the matching network. (C) 1999 American Institute of Physics. [S0021-8979(99)08021-4]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Ukegawa, S (reprint author), Matsushita Elect Wortks R&D Lab, Woburn, MA 01801 USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1999 VL 86 IS 10 BP 5365 EP 5371 DI 10.1063/1.371533 PG 7 WC Physics, Applied SC Physics GA 251GH UT WOS:000083435900006 ER PT J AU Kautz, RL AF Kautz, RL TI Using chaos to generate white noise SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DRIVEN DAMPED PENDULUM; BIASED JOSEPHSON JUNCTION; CHARACTERISTIC EXPONENTS; INTERMITTENT CHAOS; DIFFUSIVE MOTION; SCALING PROPERTY; NUMBER GENERATOR; SYSTEMS AB Numerical simulations reveal that a phase-locked loop can be operated in a chaotic regime to generate a high level of noise which is approximately white over a broad frequency range. Heuristic arguments indicate that the low-frequency power spectrum may be accurately uniform. [S0021-8979(99)04022-0]. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Kautz, RL (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 37 TC 8 Z9 8 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1999 VL 86 IS 10 BP 5794 EP 5800 DI 10.1063/1.371595 PG 7 WC Physics, Applied SC Physics GA 251GH UT WOS:000083435900070 ER PT J AU Kowalik, Z Stabeno, P AF Kowalik, Z Stabeno, P TI Trapped motion around the Pribilof Islands in the Bering Sea SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID RESIDUAL CIRCULATION; SHELF; CURRENTS; FLOW; BANKS AB Observations in the region of the Pribilof Islands and Canyon (PIC) reveal a clockwise circulation around the group of islands and around each of the two largest islands, St. Paul and St. George. Six current meters deployed around St. Paul Island revealed a steady clockwise flow around the island, which was strongest south of the island and weakest to the east. We use a high-resolution tidal model in the PIC region to show that this flow pattern results from tidal rectification over the shallow topography tides. Tidal residual currents of 10-15 cm s(-1) were predicted by the model, compared to mean currents of 5-20 cm s(-1) observed at the mooring sites. Both diurnal and semidiurnal tidal oscillations contribute to the clockwise circulation around the islands. In the diurnal band the enhanced currents occur also at the shelf slope where a tidal wave generates a shelf wave due to resonance with topography. In the PIC region the main shelf wave occurs in the Pribilof Canyon where both observations and measurements show enhancement of the diurnal tidal currents. C1 Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Kowalik, Z (reprint author), Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. NR 27 TC 28 Z9 28 U1 1 U2 10 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 1999 VL 104 IS C11 BP 25667 EP 25684 DI 10.1029/1999JC900209 PG 18 WC Oceanography SC Oceanography GA 255DC UT WOS:000083653400003 ER PT J AU Polyakov, IV Proshutinsky, AY Johnson, MA AF Polyakov, IV Proshutinsky, AY Johnson, MA TI Seasonal cycles in two regimes of Arctic climate SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ICE-OCEAN MODEL; SEA-ICE; MIXED-LAYER; CIRCULATION; COVER; SIMULATION; ANOMALIES; LINKAGES; BALANCE; SYSTEM AB The annual variability of the Arctic Ocean is characterized by a large seasonal cycle against a background of climatically significant interannual and decadal timescale variations. One of the most significant of these interannual variations is wind-driven motion in the upper Arctic Ocean which alternates between anticyclonic and cyclonic regimes. This study focuses on differences in the seasonal cycle in pears attributed to the cyclonic circulation regime (CCR), the anticyclonic circulation regime (ACCR), and the possible impact these seasonal anomalies have on fluctuations occurring over longer durations. Atmospheric, ice, and oceanic observational data and the results of numerical experiments with a coupled sea-ice-ocean model provide evidence that during the ACCR the arctic atmospheric pressure is higher and wind speed is lower compared with the CCR. A mean arctic ACCR winter is colder than a mean CCR winter. When the CCR dominates, precipitation increases over the ocean and decreases over the land. During the CCR, summer wind divergence effectively produces numerous sea-ice openings in the central Arctic Ocean. Repetition of this cyclonic process over several years results in overall thinner ice in the central Arctic, compared with that during the ACCR. Under the CCR, more ice-free summer areas lead to an accumulation of additional heat in the upper ocean, resulting in longer periods of ice melt, increases in fresher water content, and thinner ice. In CCR years both dynamical and thermodynamical factors cause excess ice and freshwater transport through Fram Strait from the Arctic into the Greenland Sea; the water balance in the Arctic Ocean is maintained via an increased inflow of the Atlantic water over the Barents Sea into the Nansen Basin. Finally, we stress that observed modifications of the Arctic Ocean thermohaline structure and Arctic Ocean-North Atlantic interactions in the early 1990s are a manifestation of the cyclonic circulation regime. C1 Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. RP Polyakov, IV (reprint author), Princeton Univ, NOAA, Atmospher & Ocean Sci Program, GFDL, POB 308, Princeton, NJ 08542 USA. NR 53 TC 54 Z9 54 U1 0 U2 4 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 1999 VL 104 IS C11 BP 25761 EP 25788 DI 10.1029/1999JC900208 PG 28 WC Oceanography SC Oceanography GA 255DC UT WOS:000083653400010 ER PT J AU Johns, E Wilson, WD Molinari, RL AF Johns, E Wilson, WD Molinari, RL TI Direct observations of velocity and transport in the passages between the Intra-Americas Sea and the Atlantic Ocean, 1984-1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EASTERN CARIBBEAN SEA; NORTH BRAZIL CURRENT; FLORIDA CURRENT; APRIL 1982; CIRCULATION; VARIABILITY; 27-DEGREES-N; BAHAMA AB Shipboard acoustic Doppler current profiler observations of the velocity in the upper 200 m of the water column collected during 1984-1996 using the National Oceanic and Atmospheric Administration RN Malcolm Baldrige are used to examine the velocity structure and transport in the passages between the Atlantic Ocean and the Intra-Americas Sea (IAS). Data were collected during 23 cruises along the following sections: across the Straits of Florida, in the Northwest Providence Channel (NWPC), across the northern passages into the Caribbean Sea (Windward, Mona, and Anegada), across the eastern Caribbean along 63 degrees 30' W, thereby forming a closed quadrangle, and in the Grenada Passage. The Florida Current, the eastern Caribbean, and the Grenada Passage share a similar mean velocity structure characterized by high-velocity, surface-intensified flows with strong vertical and horizontal shears. The northern Caribbean passages (NWPC, Windward, Mona, and Anegada) share a different common mean velocity structure, with subsurface velocity maxima directed into the IAS, and surface-intensified counterflows along one side of each passage. On average, there is a transport balance in the upper 200 m between waters entering and exiting the IAS, with the 16.5 +/- 2.4 Sv (1 Sv = 10(6) m(3)/s) transport of the Florida Current at 27 degrees N comprised of 0.4 +/- 0.8 Sv from the NWPC, 2.2 +/- 1.5 Sv from the Windward Passage, 2.8 +/- 2.1 and 2.4 +/- 2.8 Sv from the Mona and Anegada passages, respectively, and 9.5 +/- 4.7 Sv across the eastern Caribbean, for a total of 17.3 Sv. The four passages north of 17 degrees N (from NWPC to Anegada Passage) have a combined transport of 7.8 Sv, nearly half of the transport of the Florida Current in the upper 200 m. Of the 9.5 Sv flowing through the eastern Caribbean between 11 degrees N and 17 degrees N, 4.9 +/- 2.6 Sv, or more than half, come from the Grenada Passage. This is significant to the subject of cross-equatorial exchange of mass, heat, and salt, as the Grenada Passage is where the highest transport of waters originating in the southern hemisphere is thought to enter the Caribbean. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Johns, E (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Johns, Elizabeth/I-3547-2013 OI Johns, Elizabeth/0000-0002-2181-5052 NR 42 TC 23 Z9 23 U1 0 U2 3 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 1999 VL 104 IS C11 BP 25805 EP 25820 DI 10.1029/1999JC900235 PG 16 WC Oceanography SC Oceanography GA 255DC UT WOS:000083653400012 ER PT J AU Hamilton, K Wilson, RJ Hemler, RS AF Hamilton, K Wilson, RJ Hemler, RS TI Middle atmosphere simulated with high vertical and horizontal resolution versions of a GCM: Improvements in the cold pole bias and generation of a QBO-like oscillation in the tropics SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID QUASI-BIENNIAL OSCILLATION; MEAN FLOW INTERACTION; CIRCULATION MODEL; CLIMATE; WIND; STRATOSPHERE; SENSITIVITY; CYCLE; VARIABILITY; OZONE AB The large-scale circulation in the Geophysical Fluid Dynamics Laboratory "SKYHI" troposphere-stratosphere-mesosphere finite-difference general circulation model is examined as a function of vertical and horizontal resolution. The experiments examined include one with horizontal grid spacing of similar to 35 km and another with similar to 100 kin horizontal grid spacing but very high vertical resolution (160 levels between the ground and about 85 km). The simulation of the middle-atmospheric zonal-mean winds and temperatures in the extratropics is found to be very sensitive to horizontal resolution. For example, in the early Southern Hemisphere winter the South Pole near 1 mb in the model is colder than observed, but the bias is reduced with improved horizontal resolution (from similar to 70 degrees C in a version with similar to 300 km grid spacing to less than 10 degrees C in the similar to 35 km version). The extratropical simulation is found to be only slightly affected by enhancements of the vertical resolution. By contrast, the tropical middle-atmospheric simulation is extremely dependent on the vertical resolution employed. With level spacing in the lower stratosphere similar to 1.5 km, the lower stratospheric zonal-mean zonal winds in the equatorial region are nearly constant in lime. When the vertical resolution is doubled, the simulated stratospheric zonal winds exhibit a strong equatorially centered oscillation with downward propagation of the wind reversals and with formation of strong vertical shear layers. This appears to be a spontaneous internally generated oscillation and closely resembles the observed QBO in many respects, although the simulated oscillation has a period less than half that of the real QBO. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Hamilton, K (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 49 TC 81 Z9 82 U1 0 U2 5 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 1999 VL 56 IS 22 BP 3829 EP 3846 DI 10.1175/1520-0469(1999)056<3829:MASWHV>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 254CR UT WOS:000083594800001 ER PT J AU Ilavsky, J Long, GG Allen, AJ Berndt, CC AF Ilavsky, J Long, GG Allen, AJ Berndt, CC TI Evolution of the void structure in plasma-sprayed YSZ deposits during heating SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE thermal-spray deposits; small-angle scattering; sintering; yttria-stabilized zirconia; neutron scattering; thermal barrier coatings ID THERMAL BARRIER COATINGS; ENGINES; MICROSTRUCTURE; COMPONENTS; BEHAVIOR; ANGLE AB The evolution of the anisotropic void microstructure of plasma-sprayed yttria-stabilized zirconia (YSZ) deposits has been observed as a function of temperature by small-angle neutron scattering. Scattering experiments were carried out in-situ, in a furnace between 600 and 1400 degrees C. The terminal slope (Porod scattering) of the scattering spectra was used to derive the specific surface area of the voids. For samples with sufficient scattering anisotropy, the two major void systems - intersplat (inter-lamellar) pores and intrasplat cracks - could be characterized separately. The pore and crack specific surface areas were found to depend on temperature differently. The specific surface area of the intrasplat cracks decreased markedly at temperatures below 1000 degrees C, whereas the specific surface area of the intersplat pores began to decrease above 1000 degrees C. This indicates important differences in the sintering of these two void systems probably related to their size and shape. Changes in the void surface were observed at temperatures as low as 800 degrees C, a temperature comparable to, or less than, the usual operational temperature for this material. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. RP Ilavsky, J (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Ilavsky, Jan/D-4521-2013 OI Ilavsky, Jan/0000-0003-1982-8900 NR 30 TC 63 Z9 64 U1 2 U2 14 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 NOV 15 PY 1999 VL 272 IS 1 BP 215 EP 221 DI 10.1016/S0921-5093(99)00450-5 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 255AU UT WOS:000083648000027 ER PT J AU Lee, TL Pillai, MR Woicik, JC Labanda, G Lyman, PF Barnett, SA Bedzyk, MJ AF Lee, TL Pillai, MR Woicik, JC Labanda, G Lyman, PF Barnett, SA Bedzyk, MJ TI Atomic-resolution study of lattice distortions of buried InxGa1-xAs monolayers in GaAs(001) SO PHYSICAL REVIEW B LA English DT Article ID STRAINED-SEMICONDUCTOR ALLOYS; ABSORPTION FINE-STRUCTURE; RAY STANDING WAVES; HETEROSTRUCTURES; FILMS; DIFFRACTION; GA1-XINXAS; INAS AB X-ray standing wave measurements were used to study the strain in one monolayer of pseudobinary alloy InxGa1-xAs buried in GaAs(001) by molecular-beam epitaxy. The measured In position along the [001] direction exhibited a nearly linear dependence on the In concentration I, thus supporting the validity of macroscopic continuum elasticity theory at the one-monolayer limit. A random-cluster calculation using a valence force field was performed to explain microscopically the origin of the vertical expansion of the strained monolayer observed by the experiment. The calculated As-In-As bond angle and the positions of the first-nearest-neighbour As atoms of In suggest that the nearly linear dependence of the In height on the alloy composition is a combined result of the As-In-As bond bending and the local lattice distortion at the GaAs/InyGa1-yAs interface. The calculated In-As and Ca-As bond lengths were found to depend weakly on the In concentration, consistent with an earlier calculation for the case of a thick InxGa1-xAs film on GaAs(001) and the available x-ray absorption fine-structure data. [S0163-1829(99)05143-7]. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lee, TL (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RI Bedzyk, Michael/B-7503-2009; Barnett, Scott/B-7502-2009; Bedzyk, Michael/K-6903-2013 NR 31 TC 13 Z9 13 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 NOV 15 PY 1999 VL 60 IS 19 BP 13612 EP 13618 DI 10.1103/PhysRevB.60.13612 PG 7 WC Physics, Condensed Matter SC Physics GA 260GD UT WOS:000083940400062 ER PT J AU Zibrov, AS Lukin, MD Scully, MO AF Zibrov, AS Lukin, MD Scully, MO TI Nondegenerate parametric self-oscillation via multiwave mixing in coherent atomic media SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; OPTICAL INSTABILITIES; QUANTUM INTERFERENCE; SODIUM AB We demonstrate an efficient nonlinear process in which Stokes and anti-Stokes components are generated spontaneously in a multilevel medium coherently prepared by resonant, counterpropagating fields. A medium of this kind combines large nonlinear gain and efficient intrinsic feedback, thereby allowing for very weak optical fields to induce nonlinear processes. Mirrorless self-oscillation induced by microwatts of light power (nanojoules of pulse energy) is observed. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Max Planck Inst Quantenopt, D-85748 Garching, Germany. PN Lebedev Phys Inst, Moscow 117924, Russia. RP Zibrov, AS (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Zibrov, Alexander/G-7419-2014 NR 30 TC 131 Z9 132 U1 2 U2 10 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 15 PY 1999 VL 83 IS 20 BP 4049 EP 4052 DI 10.1103/PhysRevLett.83.4049 PG 4 WC Physics, Multidisciplinary SC Physics GA 255NQ UT WOS:000083676400020 ER PT J AU Mardis, KL Glemza, AJ Brune, BJ Payne, GF Gilson, MK AF Mardis, KL Glemza, AJ Brune, BJ Payne, GF Gilson, MK TI Differential adsorption of phenol derivatives onto a polymeric sorbent: A combined molecular modeling and experimental study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HYDROGEN-BOND; SELECTIVE ADSORPTION; MACRORETICULAR RESIN; AQUEOUS-SOLUTIONS; SOLVATION; ENERGY; DYNAMICS; DIFFUSION; PROGRAM; SYSTEM AB Oxygenated aromatic compounds (OACs) are used for the synthesis of a variety of commercial products. Lignin from wood and other plant products are potential sources of OACs, but it is difficult to separate the mixtures of OACs found in digests of these raw materials. One promising separation approach involves the use of selective adsorption resins, such as the acrylic ester sorbent XAD-7. It has been shown previously that this sorbent binds the para isomer of one OAC, methoxyphenol, more favorably that the ortho isomer when hexane is used as the solvent. The present study uses a combination of molecular modeling and experiment to elucidate the mechanism of this selectivity. The calculations yield good agreement with experimental binding affinities and indicate that hydrogen bonding is the dominant mode of adsorption of para-methoxyphenol onto XAD-7 from hexane. In contrast, ortho-methoxyphenol appears to form an intramolecular hydrogen bond that weakens the intermolecular hydrogen bond to the sorbent. As a consequence, ortho-methoxyphenol binds less strongly, and its association is dominated by van der Waals interactions and three-centered hydrogen bonds. This result is supported by quantum mechanical calculations and infrared spectroscopic experiments. It is also found that when water is the solvent, hydrogen bonding becomes an insignificant adsorption mechanism, and both molecules bind to the resin via nonpolar interactions. This explains the loss of selectivity that is observed in both experiment and calculation. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland Baltimore Cty, Dept Chem & Biochem Engn, Baltimore, MD 21250 USA. Univ Maryland Baltimore Cty, Ctr Agr Biotechnol, Baltimore, MD 21250 USA. RP Gilson, MK (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 34 TC 24 Z9 24 U1 0 U2 3 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 11 PY 1999 VL 103 IS 45 BP 9879 EP 9887 DI 10.1021/jp991499q PG 9 WC Chemistry, Physical SC Chemistry GA 256KU UT WOS:000083725100013 ER PT J AU Licci, F Marezio, M Huang, Q Santoro, A Bougerol-Chaillout, C Masini, R AF Licci, F Marezio, M Huang, Q Santoro, A Bougerol-Chaillout, C Masini, R TI Synthesis, structure and superconductivity of Hg0.75Mo0.25Ba2CuO4+delta SO PHYSICA C LA English DT Article DE mercury superconductors; molibdenum substitution; structure refinement; synthesis ID MERCURY-BASED SUPERCONDUCTOR; HIGH-PRESSURE; CRYSTAL-STRUCTURE; SUBSTITUTION; CR; MO; HGBA2CA2CU3O8+DELTA; RE; TI; BA AB Good quality samples of Hg0.75Mo0.25Ba2CuO4+delta were synthesised in a closed-ampoule system. The oxygen stoichiometry and T-c, were varied by annealing the samples in reducing and oxidising atmospheres. The relevant structural features were determined by powder neutron diffraction data, electron diffraction, and EDS. The additional oxygen, delta, is incorporated onto the Hg/Mo layer to provide four oxygen neighbours to each Mo. For the as-prepared sample, delta was found to be 0.59, corresponding to about an extra oxygen per every other Hg/Mo mesh. As shown by the structural refinement, these atoms do not occupy the (1/2, 1/2, 0) position, but are shifted along the diagonal at about (0.37, 0.37, 0) position. The Mo cations are displaced from the (000) position along the x-axis at (0.13, 0, 0). These shifts give rise to somewhat distorted oxygen tetrahedra surrounding the Mo cations. No superstructures were detected in any direction by election diffraction, The as-prepared samples were found to be overdoped, with T-c = 12 K, After annealing them in Ar atmosphere delta decreased from 0.59 +/- 0.02 to 0.51 +/- 0.02. The structural refinement of the sample with delta = 0.51, which exhibited a ir, of 40 K (with about 20% superconducting volume), showed that the annealing did not induce any major structural changes, except for the Mo cations which moved toward the center of the oxygen tetrahedra, This feature was taken as indication that a charge transfer occurs during the annealing. (C) 1999 Elsevier Science B.V. All rights reserved. C1 CNR, Ist Mat Speciali Elettr & Magnetismo, I-43010 Parma, Italy. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Grenoble 1, CNRS, Lab Cristallog, F-38042 Grenoble, France. CNR, Ist Tecnol Mat & Proc Energet, I-20125 Milan, Italy. RP Licci, F (reprint author), CNR, Ist Mat Speciali Elettr & Magnetismo, Parco Area Sci 37A, I-43010 Parma, Italy. RI Masini, Roberto/B-7894-2015; Bougerol, Catherine/M-6980-2015 OI Masini, Roberto/0000-0002-8656-1575; Bougerol, Catherine/0000-0002-4823-0919 NR 23 TC 5 Z9 5 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 10 PY 1999 VL 325 IS 1-2 BP 41 EP 48 DI 10.1016/S0921-4534(99)00530-4 PG 8 WC Physics, Applied SC Physics GA 261LT UT WOS:000084011200007 ER PT J AU Reipa, V Yeh, SML Monbouquette, HG Vilker, VL AF Reipa, V Yeh, SML Monbouquette, HG Vilker, VL TI Reorientation of tetradecylmethyl viologen on gold upon coadsorption of decanethiol and its mediation of electron transfer to nitrate reductases SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SILVER ELECTRODE; SURFACE; ELLIPSOMETRY; HEPTYLVIOLOGEN; PUTIDAREDOXIN; REDUCTION; BEHAVIOR; CATION; FILMS AB Decanethiol was coadsorbed with tetradecylmethyl viologen (C14MV; 1-Methyl-1'-tetradecyl-4,4'-bipyridinium chloride) on gold electrodes to improve stability of C14MV as an electrochemical mediator for coupling to nitrate reductase enzymes. Surface-enhanced Raman spectroscopy (SERS) and in situ spectroscopic ellipsometry were used to monitor the structural properties of surface-confined C14MV during its redox conversion. The potential range investigated was limited to that of the first electron transfer to give V.+, as the subsequent reduction to the neutral species is irreversible and could not be used for electron-transfer mediation to redox enzymes. When C14MV was adsorbed by itself, in the absence of C14MV solution species, the in situ optical studies showed the loss of initial electroactivity was due to the bipyridinium rings being oriented parallel to the electrode plane. This configuration is thought to be unfavorable for the anion (Cl-) transport in and out of the film, which is essential for the redox reaction. The electroactivity in the adsorbed film was restored by coadsorbing decanethiol (C10T) with C14MV. This gave an intercalated film with the end-on, bipyridinium ring oriented vertically relative to the electrode surface. In this film, the smaller methyl group is positioned closer to the electrode surface, and the bipyridinium electroactive groups are surrounded by longer decanethiol molecules. Both SERS and spectroscopic ellipsometry measurements show the presence of radical dimers in reduced surface films. Intercalated C14MV is stable for several thousand voltammetry scans and was found to be an efficient electron-transfer mediator to soluble nitrate reductase, despite being embedded in a decanethiolate layer. C1 Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Reipa, V (reprint author), Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. NR 27 TC 11 Z9 11 U1 3 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 9 PY 1999 VL 15 IS 23 BP 8126 EP 8132 DI 10.1021/la981371k PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 255RU UT WOS:000083684600036 ER PT J AU Solomon, S Stearns, CR AF Solomon, S Stearns, CR TI On the role of the weather in the deaths of R. F. Scott and his companions SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SOUTHERN OSCILLATION; TEMPERATURE; HEMISPHERE AB Robert Falcon Scott and his companions reached the South Pole in January of 1912, only to die on their return journey at a remote site on the Ross Ice Shelf, about 170 miles from their base camp on the coast. Numerous contributing causes for their deaths have been proposed, but it has been assumed that the cold temperatures they reported encountering on the Ross Ice Shelf, near 82-80 degrees S during their northward trek toward safety, were not unusual. The weather in the region where they perished on their unassisted trek by foot from the Pole remained undocumented for more than half a century, but it has now been monitored by multiple automated weather stations for more than a decade. The data recorded by Scott and his men from late February to March 19, 1912, display daily temperature minima that were on average 10 to 20 degrees F below those obtained in the same region and season since routine modern observations began in 1985. Only 1 year in the available 15 years of measurements from the location where Scott and his men perished displays persistent cold temperatures at this time of year close to those reported in 1912. These remarkably cold temperatures likely contributed substantially to the exhaustion and frostbite Scott and his companions endured, and their deaths were therefore due, at least in part, to the unusual weather conditions they endured during their cold march across the Ross Ice Shelf of Antarctica. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. RP Solomon, S (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM ssolomon@uswest.net NR 25 TC 5 Z9 5 U1 2 U2 5 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 NOV 9 PY 1999 VL 96 IS 23 BP 13012 EP 13016 DI 10.1073/pnas.96.23.13012 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 255BJ UT WOS:000083649400009 PM 10557264 ER PT J AU O'Farrell, CL Strom, MS AF O'Farrell, CL Strom, MS TI Differential expression of the virulence-associated protein p57 and characterization of its duplicated gene msa in virulent and attenuated strains of Renibacterium salmoninarum SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE Renibacterium salmoninarum; p57; msa; gene duplication; pathogenesis ID MAJOR SOLUBLE-ANTIGEN; BACTERIAL KIDNEY-DISEASE; LISTERIA-MONOCYTOGENES; SURFACE-PROTEINS; EVOLUTION; FISH; DNA; HEMAGGLUTININ; CLONING AB Virulence mechanisms utilized by the salmonid fish pathogen Renibacterium salmoninarum are poorly understood. One potential virulence factor is p57 (also designated MSA for major soluble antigen), an abundant 57 kDa soluble protein that is predominately localized on the bacterial cell surface with significant levels released into the extracellular milieu. Previous studies of an attenuated strain, MT 239, indicated that it differs from virulent strains in the amount of surface-associated p57. In this report, we show overall expression of p57 in R. salmoninarum MT 239 is considerably reduced as compared to a virulent strain, ATCC 33209. The amount of cell-associated p57 is decreased while the level of p57 in the culture supernatant is nearly equivalent between the strains. To determine if the lowered amount of cell-associated p57 was due to a sequence defect in p57, a genetic comparison was performed. Two copies of the gene encoding p57 (msa1 and msa2) were found in 33209 and MT 239, as well as in several other virulent isolates. Both copies from 33209 and MT 239 were cloned and sequenced and found to be identical to each other, and identical between the 2 strains. A comparison of msa1 and msa2 within each strain showed that their sequences diverge 40 base pairs 5' to the open reading frame, while sequences 3' to the open reading frame are essentially identical for at least 225 base pairs. Northern blot analysis showed no difference in steady state levels of msa mRNA between the 2 strains. These data suggest that while cell-surface localization of p57 may be important for R. salmoninarum virulence, the differences in localization and total p57 expression between 33209 and MT 239 are not due to differences in msa sequence or differences in steady state transcript levels. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, US Dept Commerce, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. US Geol Survey, Western Fisheries Res Ctr, Biol Resources Div, Seattle, WA 98115 USA. RP Strom, MS (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, US Dept Commerce, Seattle, WA 98112 USA. NR 40 TC 20 Z9 21 U1 0 U2 2 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 8 PY 1999 VL 38 IS 2 BP 115 EP 123 DI 10.3354/dao038115 PG 9 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 271TY UT WOS:000084610600005 PM 10598282 ER PT J AU Morado, JF Giesecke, RH Syrjala, SE AF Morado, JF Giesecke, RH Syrjala, SE TI Molt related mortalities of the Dungeness crab Cancer magister caused by a marine facultative ciliate Mesanophrys pugettensis SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE Dungeness crab; Cancer magister; crustacean; molt; Mesanophrys pugettensis; ciliate; mortalities ID N-SP SCUTICOCILIATIDA; CHIONOECETES-BAIRDI; CALLINECTES-SAPIDUS; HOMARUS-AMERICANUS; BLUE-CRAB; ORCHITOPHRYIDAE; INFECTION; DECAPODA; OPILIO; CYCLE AB In May of 1990, a number of Dungeness crabs Cancer magister were found dead or dying on a private beach in Samish Bay, Washington, USA. The hemolymph of a small number of randomly collected crabs was examined by bright field microscopy and found to be infected by a recently described ciliate Mesanophrys pugettensis. The same ciliate was found in subsequent 1990 collections of Dungeness, rock C. productus and kelp Pugettia producta crabs collected at the private beach and Clayton Beach, Samish Bay, Washington. M. pugettensis was again encountered in Dungeness and rock crabs collected from the same survey sites in 1991 and 1992, but not in limited beach collections in 1993. During the 1990-1992 survey period, a total of 654 Dungeness crabs were collected from the 2 study sites. Logistic regression analysis indicated that shell condition and size (i.e. carapace width) are significant predictors of ciliate infection (p < 0.0001, p < 0.005, respectively); the probability of infection is highly correlated with increase in carapace width. This is the first report implicating a ciliate as a cause of remarkable, wild crab mortalities and the first to clearly associate non-apostome ciliate infections with molting. The similarities of Dungeness crab ciliate disease to other protistan diseases of wild crustaceans is discussed, suggesting that a number of other protistan pathogens likely enter their host during or shortly after molting. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Resource Assessment & Conservat Engn Div, Seattle, WA 98115 USA. RP Morado, JF (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Resource Assessment & Conservat Engn Div, Seattle, WA 98115 USA. NR 36 TC 16 Z9 16 U1 1 U2 2 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 8 PY 1999 VL 38 IS 2 BP 143 EP 150 DI 10.3354/dao038143 PG 8 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 271TY UT WOS:000084610600008 ER PT J AU Nizkorodov, SA Harper, WW Chapman, WB Blackmon, BW Nesbitt, DJ AF Nizkorodov, SA Harper, WW Chapman, WB Blackmon, BW Nesbitt, DJ TI Energy-dependent cross sections and nonadiabatic reaction dynamics in F(P-2(3/2), P-2(1/2))+n-H-2 -> HF(v,J)+H SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DEGENERATE ELECTRONIC STATES; MOLECULAR-BEAM EXPERIMENTS; F+H2 REACTION; PHOTOELECTRON-SPECTROSCOPY; F+H-2->HF+H REACTION; REACTION-PRODUCTS; TRANSITION-STATE; ATOMIC FLUORINE; RATE CONSTANTS; REACTION F+D-2 AB High-sensitivity direct IR laser absorption methods are exploited to investigate quantum state-resolved reactive scattering dynamics of F+n-H-2 (j = 0,1) --> HF(v, J) + H in low-density crossed supersonic jets under single collision conditions. Nascent rotational state distributions and relative cross sections for reactive scattering into the energetically highest HF (v = 3,J) vibrational manifold are obtained as a function of center-of-mass collision energies from E-com =2.4 kcal/mole down to 0.3 kcal/mole. This energy range extends substantially below the theoretically predicted transition state barrier [E-barrier approximate to 1.9 kcal/mole; K. Stark and H. Werner, J. Chem. Phys. 104, 6515 (1996)] for the lowest adiabatic F(P-2(3/2)) + H-2 potential energy surface, therefore preferentially enhancing nonadiabatic channels due to spin-orbit excited F*( P-2(1/2)) (Delta Espin-orbit = 1.15 kcal/mole) in the discharge source. The HF (v = 3,J) cross sections decrease gradually from 2.4 kcal/ mole down to the lowest energies investigated (E-com approximate to 0.3 kcal/ mole), in contrast with exact adiabatic quantum calculations that predict a rapid decrease below E-com approximate to 1.9 kcal/mole and vanishing reaction probability by E-com approximate to 0.7 kcal/mol. Further evidence for a nonadiabatic F*(P-2(1/2)) reaction channel is provided by nascent rotational state distributions in HF (v = 3,J), which are >2-3-fold hotter than predicted by purely adiabatic calculations. Most dramatically, the nascent product distributions reveal multiple HF (v = 3,J) rovibrational states that would be energetically inaccessible from ground state F(P-2(3/2)) atom reactions. These quantum state resolved reactive scattering studies provide the first evidence for finite nonadiabatic dynamics involving multiple potential energy surfaces in this well-studied "benchmark'' F+H-2 reaction system. (C) 1999 American Institute of Physics. [S0021-9606(99)00242-1]. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Nizkorodov, SA (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Nizkorodov, Sergey/I-4120-2014 OI Nizkorodov, Sergey/0000-0003-0891-0052 NR 96 TC 63 Z9 65 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 1999 VL 111 IS 18 BP 8404 EP 8416 DI 10.1063/1.480182 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 249RB UT WOS:000083345100019 ER PT J AU Akpalu, YA Amis, EJ AF Akpalu, YA Amis, EJ TI Evolution of density fluctuations to lamellar crystals in linear polyethylene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-SCATTERING; INDUCTION PERIOD; SMALL-ANGLE; SOLUTION CRYSTALLIZATION; STRUCTURAL FORMATION; SINGLE-CRYSTALS; MELT; MORPHOLOGY; POLY(ETHYLENE-TEREPHTHALATE); POLYMERS AB Structure formation during the isothermal crystallization of a linear polyethylene ( M-w = 32 100 g/mol, M-w/M-n = 1.1) has been monitored by simultaneous real time small-angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) with synchrotron radiation. Changes in the crystalline and amorphous scattering in WAXS occur simultaneously with the changes observed in the SAXS intensity profile, suggesting that the resulting scattering is a consequence of forming crystals. At the early stage of crystal growth, the SAXS intensity at q<0.02 Angstrom(-1) increases while that at higher wave vectors remains constant. Meanwhile, the apparent crystallinity from WAXS increases to about 10% before two peaks in the SAXS intensity profile can be resolved. As lamellar stacks develop, the period corresponding to the first SAXS peak, L-1, decreases initially. After reaching a minimum, L-1 further increases with crystallization time. On the other hand, the period corresponding to the second SAXS peak increases with crystallization time. At late times, the rate of increase is very slow. Changes in the crystallinity obtained from WAXS and the total scattering power from SAXS were evaluated and compared with a model for the crystallizing system which accounts for changes in the fraction of lamellar aggregates. The relative importance of two secondary crystallization processes, namely the formation of new lamellar stacks and increase in the crystallinity within lamellae, were evaluated during and after primary crystallization. (C) 1999 American Institute of Physics. [S0021-9606(99)51441-4]. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP NIST, Div Polymers, Gaithersburg, MD 20899 USA. EM eric.amis@nist.gov NR 53 TC 29 Z9 29 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 8 PY 1999 VL 111 IS 18 BP 8686 EP 8695 DI 10.1063/1.480208 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 249RB UT WOS:000083345100050 ER PT J AU Li, J Bierbaum, VM Leone, SR AF Li, J Bierbaum, VM Leone, SR TI Laser ionization time-of-flight mass spectrometer detection of methyl radical produced by ion-molecule reactions in a flowing-afterglow apparatus SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; HYDROCARBON IONS; RATE CONSTANTS; 300 K; ENERGIES; ISOPROPYL; HYDROGEN; METHANE; ETHYL; CO+ AB Laser ionization time-of-flight mass spectrometer detection is coupled with a flowing-afterglow instrument for the first time to detect the methyl radical, CH,, produced from the gas phase reactions of CO+ with CH4 and N2O+ with CH4. Single-photon ionization at 118 nm (10.5 eV) permits a new means of detection for the neutral radical products of gas-phase ion-molecule reactions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Biochem & Chem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 25 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 5 PY 1999 VL 313 IS 1-2 BP 76 EP 84 DI 10.1016/S0009-2614(99)01026-X PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 256KE UT WOS:000083723800013 ER PT J AU Broecker, WS Sutherland, S Peng, TH AF Broecker, WS Sutherland, S Peng, TH TI A possible 20th-century slowdown of Southern Ocean deep water formation SO SCIENCE LA English DT Article ID WEDDELL SEA; BOTTOM-WATER; THERMOHALINE CIRCULATION; LAST DEGLACIATION; CLIMATE-CHANGE; DISTRIBUTIONS; ACCUMULATION; TEMPERATURE; HOLOCENE; BALANCE AB Chlorofluorocarbon-11 inventories for the deep Southern Ocean appear to confirm physical oceanographic and geochemical studies in the Southern Ocean, which suggest that no more than 5 x 10(6) cubic meters per second of ventilated deep water is currently being produced. This result conflicts with conclusions based on the distributions of the carbon-14/carbon ratio and a quasi-conservative property, PO4*, in the deep sea, which seem to require an ;average of about 15 x 10(6) cubic meters per second of Southern Ocean deep ventilation over about the past 800 years. A major reduction in Southern Ocean deep water production during the 20th century (from high rates during the Little Ice Age) may explain this apparent discordance. If this is true, a seesawing of deep water production between the northern Atlantic and Southern oceans may lie at the heart of the 1500-year ice-rafting cycle. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Broecker, WS (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NR 41 TC 118 Z9 118 U1 2 U2 18 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 5 PY 1999 VL 286 IS 5442 BP 1132 EP 1135 DI 10.1126/science.286.5442.1132 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 253AJ UT WOS:000083534200036 ER PT J AU Lemmon, EW Tillner-Roth, R AF Lemmon, EW Tillner-Roth, R TI A Helmholtz energy equation of state for calculating the thermodynamic properties of fluid mixtures SO FLUID PHASE EQUILIBRIA LA English DT Article DE equation of state; density; Helmholtz energy; mixture model; thermodynamic properties; vapor-liquid equilibria ID VAPOR-LIQUID-EQUILIBRIA; BINARY-SYSTEMS; PRESSURES; AMMONIA; FORMULATION; BUTANE; MPA AB A new approach has been developed for calculating the properties of mixtures based on an equation of state explicit in reduced Helmholtz energy. This approach allows for the representation of the thermodynamic properties over a wide range of fluid states and is based on highly accurate equations of state for the pure components combined at the reduced temperature and density of the mixture. The reducing parameters used for temperature and density depend on composition. For simple mixtures (those that closely follow Raoult's law), a very accurate representation of all thermodynamic properties has been achieved with relatively simple functions. For nonideal mixtures, the reducing functions for density and temperature were modified, and a departure function was added to the equation of state. Generally, the model is able to represent liquid and vapor states with uncertainties of 0.1% in density, 1% in heat capacities and 1% in bubble point pressures if experimental data of comparable uncertainties exist. Two applications of the mixture model concepts were developed independently by the authors in the United States and Germany over the same time period. These applications include the development of individual equations for each binary system and a generalization of the model which is valid for a wide variety of mixtures. The individual approaches are presented with an explanation of the similarities and differences. Although the paper focuses mainly on binary systems, some results for ternary mixtures are also presented. (C) 1999 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Univ Hannover, Inst Thermodynam, D-30167 Hannover, Germany. Univ Idaho, Ctr Appl Thermodynam Studies, Moscow, ID 83844 USA. RP Lemmon, EW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 33 TC 35 Z9 39 U1 1 U2 14 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 4 PY 1999 VL 165 IS 1 BP 1 EP 21 DI 10.1016/S0378-3812(99)00262-9 PG 21 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 254FE UT WOS:000083600600001 ER PT J AU Simon, CG Holloway, PW Gear, ARL AF Simon, CG Holloway, PW Gear, ARL TI Exchange of C-16-ceramide between phospholipid vesicles SO BIOCHEMISTRY LA English DT Article ID PROTEIN-KINASE-C; NECROSIS-FACTOR-ALPHA; NEUTRAL SPHINGOMYELINASE; UNILAMELLAR VESICLES; ACID SPHINGOMYELINASE; PLATELET-AGGREGATION; SIGNAL-TRANSDUCTION; PHYSICAL-PROPERTIES; CERAMIDE SYNTHASE; INDUCED APOPTOSIS AB Ceramide is considered to be an important signaling molecule in cellular processes such as cell growth, secretion, differentiation, and apoptosis. This implies that the molecule is able to move between cellular membranes. However, the ability of the molecule to undergo such exchange has been largely ignored despite the profound impact that this ability would have on its mechanism of action in signal-transduction cascades. With this in mind, the ability of a long-chain, radioactive ceramide, C-14-C-16-ceramide, to exchange between populations of lipid vesicles was evaluated. The rate of exchange of C-14-C-16-ceramide between lipid vesicles at lipid concentrations commonly found in cells (10-110 mM) was on the order of days (t(1/2) of 45-109 h). Simultaneous observations revealed negligible exchange of H-3-cholesteryl oleate, which was included as a nontransferable marker to control for artifacts such as vesicle fusion and aggregation. In addition, all of the ceramide was exchangeable, and the exchange followed monoexponential kinetics, indicating that the ceramide underwent transbilayer movement at a rate faster than or equal to its rate of intervesicle exchange. Two conclusions can be drawn from these observations: (i) the spontaneous transfer of ceramide between cellular membranes is too slow to play a role in rapid, inter-membrane signaling phenomena and can only be a factor in cell functions that take place over days; and (ii) without the aid of an exchange protein, ceramide can only interact with target molecules that are located at the membrane where the ceramide is formed. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Virginia, Sch Med, Dept Biochem & Mol Genet, Charlottesville, VA 22908 USA. RP Gear, ARL (reprint author), Natl Inst Stand & Technol, Div Polymers, 100 Bur Dr, Gaithersburg, MD 20899 USA. FU NHLBI NIH HHS [HL-27014] NR 67 TC 34 Z9 34 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 2 PY 1999 VL 38 IS 44 BP 14676 EP 14682 DI 10.1021/bi991537w PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 255JF UT WOS:000083665200029 PM 10545193 ER PT J AU Sander, LC Pursch, M Wise, SA AF Sander, LC Pursch, M Wise, SA TI Shape selectivity for constrained solutes in reversed-phase liquid chromatography SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; BLOCK-LIKE SOLUTES; OCTADECYLSILANE STATIONARY PHASES; ALKYL CHAIN CONFORMATION; MODIFIED SILICA SURFACES; SOLID-STATE NMR; COLUMN SELECTIVITY; MOLECULAR THEORY; NEUTRON-SCATTERING; RETENTION BEHAVIOR AB In reversed-phase Liquid chromatography (RPLC), the separation of compound mixtures of similar polarity can present a significant challenge for the analyst. Examples of such compounds include geometric isomers present kin environmental samples (e.g., polycyclic aromatic hydrocarbons, polycyclic aromatic sulfur heterocycles, and polychlorinated biphenyl congeners) and compounds of biological significance (e.g., carotenoids and steroids). In general, compounds with rigid, well-defined molecular shape are best separated using a column with enhanced shape selectivity characteristics. This perspective presents an overview of column properties that influence shape selectivity for constrained solutes. Approaches to the characterization of stationary-phase structure are described, and the findings are correlated with chromatographic performance. Finally, retention models of shape discrimination are presented that are consistent with observed retention behavior. An appreciation for shape recognition effects in RPLC will facilitate method development for certain classes of difficult to resolve compounds. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sander, LC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 61 TC 125 Z9 126 U1 3 U2 20 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 NOV 1 PY 1999 VL 71 IS 21 BP 4821 EP 4830 DI 10.1021/ac9908187 PG 10 WC Chemistry, Analytical SC Chemistry GA 252EX UT WOS:000083490100030 PM 21662833 ER PT J AU Williams, PA AF Williams, PA TI Mode-coupled artifact standard for polarization-mode dispersion: design, assembly, and implementation SO APPLIED OPTICS LA English DT Article AB A stack of quasi-randomly oriented quartz plates has been assembled as a calibration artifact for mode-coupled polarization-mode dispersion. The design of the artifact, the reasons for choosing it, the procedure for its assembly, and its implementation are described. Considerable discussion is also devoted to the fact that, this mode-coupled artifact is limited in scope to polarimetric measurement techniques (those that directly measure differential group delay as a function of wavelength). OCIS codes: 000.2270, 060.2300. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Williams, PA (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway,MS 815-02, Boulder, CO 80303 USA. EM paul.williams@nist.gov NR 21 TC 9 Z9 9 U1 0 U2 0 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 1999 VL 38 IS 31 BP 6498 EP 6507 DI 10.1364/AO.38.006498 PG 10 WC Optics SC Optics GA 253LF UT WOS:000083557500005 PM 18324181 ER PT J AU Williams, PA AF Williams, PA TI Rotating-wave-plate Stokes polarimeter for differential group delay measurements of polarization-mode dispersion SO APPLIED OPTICS LA English DT Article AB We present a description and detailed uncertainty analysis of a polarization-mode dispersion (PMD) measurement system that uses the Jones matrix eigenanalysis measurement technique based on a rotating-wave-plate Stokes polarimeter. The uncertainty of the system is 3.2 fs (similar to 95% confidence interval) and is due primarily to PMD in the fiber leads of the measurement system. OCIS codes: 060.2270, 060.2300. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Williams, PA (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway,MS 815-02, Boulder, CO 80303 USA. EM paul.williams@nist.gov NR 15 TC 31 Z9 31 U1 0 U2 1 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 1999 VL 38 IS 31 BP 6508 EP 6515 DI 10.1364/AO.38.006508 PG 8 WC Optics SC Optics GA 253LF UT WOS:000083557500006 PM 18324182 ER PT J AU Zimmerman, BE Cessna, JT AF Zimmerman, BE Cessna, JT TI The standardization of Cu-62 and experimental determinations of dose calibrator settings for generator-produced (CuPTSM)-Cu-62 SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID COPPER-62-PTSM; PET AB The Positron Emission Tomography agent Cu-62 Pyruvaldehyde Bis(N-4-methyl)thiosemicarbazone (PTSM) has been standardized by the National Institute of Standards and Technology (NIST) using 4 pi beta liquid scintillation counting with H-3-standard efficiency tracing. Using a measurement model developed at NIST for the determination of experimental dose calibrator dial settings for short-lived radionuclides, the correct dial settings for (CuPTSM)-Cu-62 in a clinically useful geometry (a 35 mi plastic syringe containing 33 mi of solution) as well as the standard NIST 5 ml glass ampoule have been elucidated. This measurement model is fully described, as is the treatment of associated uncertainties. The correct instrument settings for the NIST Capintec CRC-12 re-entrant ionization chamber ('dose calibrator') were found to be `499 +/- 6' and '489 +/- 8', respectively, for the syringe and ampoule geometries. The stated uncertainties are expanded (k = 2) uncertainties. The expanded uncertainties in the measured activity arising from these new dial settings are +/-0.8% and +/-1.4%, respectively, for the syringe and ampoule. The measured activities using these settings are lower than those obtained from the manufacture's recommended setting of '448' by 9.7% for the syringe and 7.7% for the ampoule, and underscore the need for experimental verification of the dose calibrator settings for each radionuclide and each geometry used in the clinic. Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. RP Zimmerman, BE (reprint author), Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 21 TC 12 Z9 13 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD NOV PY 1999 VL 51 IS 5 BP 515 EP 526 DI 10.1016/S0969-8043(99)00078-0 PG 12 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 223JR UT WOS:000081838400005 PM 10464921 ER PT J AU Sanger, DM Holland, AE Scott, GI AF Sanger, DM Holland, AE Scott, GI TI Tidal creek and salt marsh sediments in South Carolina coastal estuaries: I. Distribution of trace metals SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID BOTTOM-FEEDING FISH; TROPHIC TRANSFER; ACCUMULATION; ENVIRONMENTS; MEIOBENTHOS; POLLUTION; HABITATS; HISTORY; ZONE AB Twenty-eight tidal creeks were sampled along the South Carolina coast in the summer of 1995 to determine the levels of sediment trace metal contamination associated with different types and varying levels of human development in their watersheds. The particle size and total organic carbon (TOC) content of creek sediments in developed watersheds (i.e., industrial, urban, and suburban) were similar to that in watersheds with little or no development (i.e., forested or reference). Those trace metals commonly associated with urban and industrial sources, including Cu, Cr, Pb, Zn, Cd, and Hg, were in significantly higher concentrations in tidal creeks located in industrial/urban watersheds compared to the suburban and forested watersheds. Sediment trace metal concentrations were similar for creeks located in suburban and forested watersheds and 2 to 10 times lower than the creeks located in industrial/urban watersheds. Concentrations of trace metals primarily associated with the natural weathering of basement rock, including Al, Fe, As, Ni, and Mn, were not significantly different among watershed types. Four of the tidal creek-salt marsh systems were extensively sampled from the creek channel to the marsh-upland interface to characterize sediment trace metal spatial distributions within creek-marsh systems. Sediment particle size, TOC, and trace metal concentrations varied spatially within each creek-marsh system depending on the type of development in the watershed and the probable source of metals. The creek-marsh system selected to represent the industrial development had significantly higher "anthropogenic" trace metal concentrations compared to the other creek-marsh systems. This system also had trace metal distributional patterns that appeared to be associated with several localized sources of metals on the marsh surface. Both the "anthropogenic" and "natural" trace metal concentrations and spatial distributions were similar among and within the forested and suburban creek-marsh systems. C1 S Carolina Dept Nat Resources, Marine Resources Res Inst, Charleston, SC 29422 USA. Univ S Carolina, Marine Sci Program, Columbia, SC 29208 USA. Univ S Carolina, Belle W Baruch Inst Marine Biol & Coastal Res, Columbia, SC 29208 USA. Natl Ocean Serv, Natl Ocean & Atmospher Adm, Charleston Ctr Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Holland, AE (reprint author), S Carolina Dept Nat Resources, Marine Resources Res Inst, 217 Ft Johnson Rd, Charleston, SC 29422 USA. NR 35 TC 58 Z9 62 U1 2 U2 21 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 NOV PY 1999 VL 37 IS 4 BP 445 EP 457 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 246FC UT WOS:000083152900004 PM 10508892 ER PT J AU Sanger, DM Holland, AF Scott, GI AF Sanger, DM Holland, AF Scott, GI TI Tidal creek and salt marsh sediments in South Carolina coastal estuaries: II. Distribution of organic contaminants SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; GEOCHEMISTRY; HABITATS; REGION; RIVER AB Twenty-eight tidal creeks along the South Carolina coast were sampled during the summer of 1995 to determine the levels of sediment contamination including organic chemicals (i.e., polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], and DDT and its metabolites) associated with different types and varying levels of watershed development (i.e., industrial/urban, suburban, forested, and salt marsh). Organic analysis utilized high-performance liquid chromatography (HPLC) with fluorescence detection and capillary gas chromatography-ion trap mass spectrometry (GC-ITMS) for PAHs, and gas chromatography with electron capture detection (GC-ECD) for pesticides and PCBs. Results indicated that creeks with industrial/urban watersheds had significantly higher concentrations of PAHs, PCBs, and DDT compared with creeks with suburban and forested (reference) watersheds. The suburban watershed class of creeks had concentrations of half the PAH analytes and the total PCBs which exceeded the concentrations found in the forested watershed class of creeks. The spatial distribution of organic contaminants was evaluated in four of these tidal creek-salt marsh systems representing urban/industrial, suburban, and forested watersheds, from, the creek channel. to the adjacent uplands. The distribution of organic contaminants within each representative creek was not concordant with the total organic carbon or the clay content of the sediment. The representative industrial/urban creek-marsh system, Diesel Creek, had the highest concentration of PAHs in the creek channel and the highest concentration of PCBs and DDT on the marsh surface, primarily in the upper portion of the system, The representative suburban creek-marsh system, Shem Creek, had elevated levels of both PAHs and PCBs throughout the entire system. This system also had one site with a total PAH concentration of 324,000 ppb and a total DDT concentration that was 20-100 times higher than the other sites. One of the representative forested creek-marsh systems, Rathall Creek, had low levels of the three organic contaminants except for one sampling site that had PAH concentrations a factor of 10 higher than the other sites. The other representative forested creek-marsh system, Long Creek, bad low levels of PAHs and PCBs, but elevated levels of DDT were observed, particularly in the upper portion on the marsh surface. The results of this study suggest that (1) anthropogenic alteration of the land cover in the watersheds of tidal creek-salt marsh systems may increase the organic contaminant loadings in the sediment, and (2) tidal creek-salt marsh sediments, particularly in the creek channel, are repositories and potentially conduits of organic contaminants from the upland environment to the deeper estuarine areas. C1 S Carolina Dept Nat Resources, Marine Resources Res Inst, Charleston, SC 29422 USA. Univ S Carolina, Marine Sci Program, Columbia, SC 29208 USA. Univ S Carolina, Belle W Baruch Inst Marine Biol & Coastal Res, Columbia, SC 29208 USA. Natl Ocean Serv, Natl Ocean & Atmospher Adm, Charleston Ctr Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Holland, AF (reprint author), S Carolina Dept Nat Resources, Marine Resources Res Inst, 217 Ft Johnson Rd, Charleston, SC 29422 USA. NR 33 TC 79 Z9 88 U1 4 U2 27 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 NOV PY 1999 VL 37 IS 4 BP 458 EP 471 PG 14 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 246FC UT WOS:000083152900005 PM 10508893 ER PT J AU Reeder, DJ AF Reeder, DJ TI Impact of DNA typing on standards and practice in the forensic community SO ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE LA English DT Article; Proceedings Paper CT XXXIV Conference of the College-of-American-Pathologists on Molecular Pathology: Role in Improving Patient Outcome CY FEB 26-28, 1999 CL BETHESDA, MARYLAND SP Coll Amer Pathologists ID PROFILING MEASUREMENTS AB This article reviews the history of DNA-based human identification from its inception in 1985. Since the development of the technology, experts called for setting of standards and use of proficiency tests for quality assurance measures. The response of the National Institute of Standards and Technology to DNA forensic standards needs was catalyzed by the Technical Working Group on DNA Analysis Methods, sponsored by the Federal Bureau of Investigation with funding provided by the National Institute of justice. Standard reference materials were developed for the original technologies used in DNA identification and for the newer polymerase chain reaction-based technologies. Adoption of recommended standards developed through the Federal Bureau of Investigation-commissioned DNA Advisory Board show the acceptance of National Institute of Standards and Technology standards for calibration of laboratory protocols. New technologies will require a process of validation and continued testing through the use of proficiency tests, such as those provided through the College of American Pathologists. Robotics and parallel processing of samples will lead to increased efficiency in DNA testing. The use of DNA data banks of convicted felons will increase dramatically with the the Federal Bureau of Investigation's national implementation of a computerized identification system known as the Combined DNA Index System. This system that will make major use of short, tandem, repeat genetic systems and will be the major driver of technology for the next 5 to 10 years. Finally, sample collection and training are of major concern for those who look at the long-term impact of DNA testing in forensic laboratories. C1 NIST, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Reeder, DJ (reprint author), NIST, Chem Sci & Technol Lab, Div Biotechnol, 100 Bureau Dr,Stop 8311, Gaithersburg, MD 20899 USA. NR 10 TC 9 Z9 11 U1 2 U2 5 PU COLLEGE AMER PATHOLOGISTS PI NORTHFIELD PA C/O KIMBERLY GACKI, 325 WAUKEGAN RD, NORTHFIELD, IL 60093-2750 USA SN 0003-9985 J9 ARCH PATHOL LAB MED JI Arch. Pathol. Lab. Med. PD NOV PY 1999 VL 123 IS 11 BP 1063 EP 1065 PG 3 WC Medical Laboratory Technology; Medicine, Research & Experimental; Pathology SC Medical Laboratory Technology; Research & Experimental Medicine; Pathology GA 253YD UT WOS:000083584000018 PM 10539909 ER PT J AU White, RA Bliton, H Bhavsar, SP Bornmann, P Burns, JO Ledlow, MJ Loken, C AF White, RA Bliton, H Bhavsar, SP Bornmann, P Burns, JO Ledlow, MJ Loken, C TI A catalog of nearby poor clusters of galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; galaxies : clusters : general ID RICH CLUSTERS; CD GALAXIES AB A catalog of 732 optically selected, nearby poor clusters of galaxies covering the entire sky north of -3 degrees declination is presented. The poor clusters, called WBL clusters, were identified as concentrations of three or more galaxies with photographic magnitudes brighter than 15.7, possessing a galaxy surface overdensity of 10(4/3). These criteria are consistent with those used in the identification of the original Yerkes poor clusters, and this new catalog substantially increases the sample size of such objects. These poor clusters cover the entire range of galaxy associations up to and including Abell clusters, systematically including poor and rich galaxy systems spanning over 3 orders of magnitude in the cluster mass function. As a result, this new catalog contains a greater diversity of richness and structures than other group catalogs, such as the Hickson and Yerkes catalogs. The information on individual galaxies includes redshifts and cross-references to other galaxy catalogs. The entries for the clusters include redshift (where available) and cross-references to other group and cluster catalogs. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP White, RA (reprint author), NASA, Goddard Space Flight Ctr, Code 631, Greenbelt, MD 20771 USA. NR 21 TC 58 Z9 58 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 NOV PY 1999 VL 118 IS 5 BP 2014 EP 2037 DI 10.1086/301103 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800009 ER PT J AU Tumlinson, J Giroux, ML Shull, JM Stocke, JT AF Tumlinson, J Giroux, ML Shull, JM Stocke, JT TI New HST observations of the halo gas of NGC 3067: Limits on the extragalactic ionizing background at low redshift and the Lyman continuum escape fraction SO ASTRONOMICAL JOURNAL LA English DT Article DE diffuse radiation; galaxies : halos; galaxies : individual (NGC 3067); intergalactic medium; quasars : absorption lines; quasars : individual (3C 232) ID ABSORPTION SYSTEMS; RADIATIVE-TRANSFER; SPACE-TELESCOPE; ULTRAVIOLET; GALAXIES; DISKS; CLOUD AB We present ultraviolet spectroscopy from HST/GHRS and reanalyze existing Ha images of the quasar/galaxy pair 3C 232/NGC 3067 and of the halo gas associated with NGC 3067. The spectra permit measurement of, or limits on, the column densities of Fe I, Fe II, Mg I, and Mg II in the absorbing cloud. Two distinct models of the extragalactic radiation field are considered: (1) the ionizing spectrum is dominated by a power-law extragalactic continuum, and (2) the power-law spectrum contains a Lyman break, implying enhanced flux longward of 912 Angstrom relative to the hydrogen-ionizing flux. Models of the second type are required to fully explore the ionization balance of the Fe and Mg in the model cloud. The Ha images constrain the escape fraction of Lyman continuum photons from the galaxy to f(esc) less than or equal to 0.02. With the assumption that the cloud is shielded from all galactic contributions, we can constrain the intensity and shape of the extragalactic continuum. For an AGN-dominated power-law extragalactic spectrum, we derive a limit on the extragalactic ionizing flux Phi(ion) greater than or equal to 2600 photons cm(-2) s(-1), or I-0 greater than or equal to 10(-23) ergs cm(-2) s(-1) Hz(-1) sr(-1) for a v(-1.8) ionizing spectrum and a cloud of constant density. When combined with previous upper limits from the absence of Ha recombination emission from intergalactic clouds, our observations require 2600 less than or equal to Phi(ion) less than or equal to 10,000 photons cm(-2) s(-1). We show that if galactic contributions to the incident radiation are important, it is difficult to constrain Phi(ion). These results demonstrate that galactic halo opacities and their wavelength dependence are crucial to understanding the abundance of low-ionization metals in the IGM. C1 Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. RP Tumlinson, J (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, CB 389, Boulder, CO 80309 USA. NR 36 TC 31 Z9 31 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 NOV PY 1999 VL 118 IS 5 BP 2148 EP 2157 DI 10.1086/301106 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800018 ER PT J AU Ringwood, AH Hameedi, MJ Lee, RF Brouwer, M Peters, EC Scott, GI Luoma, SN DiGiulio, RT Depledge, M Steinert, S Teh, S Van Beneden, R Winston, G Epel, D Minier, C Narbonne, JF Peters, L Roesijadi, G Viarengo, A Werner, I Anderson, R Burnett, L Chu, FL Oliver, L Paynter, K AF Ringwood, AH Hameedi, MJ Lee, RF Brouwer, M Peters, EC Scott, GI Luoma, SN DiGiulio, RT Depledge, M Steinert, S Teh, S Van Beneden, R Winston, G Epel, D Minier, C Narbonne, JF Peters, L Roesijadi, G Viarengo, A Werner, I Anderson, R Burnett, L Chu, FL Oliver, L Paynter, K TI Bivalve Biomarker Workshop: overview and discussion group summaries SO BIOMARKERS LA English DT Editorial Material C1 Marine Resources Res Inst, Charleston, SC 29412 USA. NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. Univ Georgia, Skidaway Inst Oceanog, Savannah, GA 31411 USA. Univ So Mississippi, Inst Marine Sci, Dept Coastal Sci, Ocean Springs, MS 39564 USA. Tetra Tech Inc, Fairfax, VA 22030 USA. US Geol Survey, Menlo Park, CA 94025 USA. Duke Univ, Sch Environm, Durham, NC 27708 USA. Univ Maryland, Solomons, MD USA. Gulf Coast Res Lab, Ocean Springs, MS 39564 USA. Univ Charleston, Charleston, SC USA. NOAA, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. Coll William & Mary, Gloucester Point, VA USA. Univ Plymouth, Plymouth PL4 8AA, Devon, England. Stanford Univ, Pacific Grove, CA USA. US EPA, Gulf Breeze, FL USA. US Geol Serv, Menlo Park, CA USA. Lab Ecotoxicol, Lyon, France. Univ Bordeaux, Talence, France. Univ Maryland, College Pk, MD 20742 USA. Plymouth Marine Lab, Plymouth, Devon, England. Comp Sci Corp, San Diego, CA 92110 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Maine, Orono, ME USA. Dept Sci Technol, Alessandria, Italy. N Carolina State Univ, Raleigh, NC 27695 USA. RP Ringwood, AH (reprint author), Marine Resources Res Inst, 217 Ft Johnson Rd, Charleston, SC 29412 USA. RI Paynter, Kennedy/F-9717-2013 NR 0 TC 30 Z9 31 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1354-750X J9 BIOMARKERS JI Biomarkers PD NOV-DEC PY 1999 VL 4 IS 6 BP 391 EP 399 PG 9 WC Biotechnology & Applied Microbiology; Toxicology SC Biotechnology & Applied Microbiology; Toxicology GA 266AZ UT WOS:000084279600001 ER PT J AU Van Beneden, RJ Rhodes, LD Gardner, GR AF Van Beneden, RJ Rhodes, LD Gardner, GR TI Potential alterations in gene expression associated with carcinogen exposure in Mya arenaria SO BIOMARKERS LA English DT Article DE inducible gene expression; biomarker; bivalve; dioxin ID POLYMERASE CHAIN-REACTION; DIFFERENTIAL DISPLAY; RIBOSOMAL-PROTEIN; DOWN-REGULATION; MESSENGER-RNAS; CDNA; CYTOCHROME-P-450; IDENTIFICATION; TRANSCRIPTION; HERBICIDES AB Gonadal cancers in soft-shell clams (Mya arenaria) have been found at high prevalences (20-40%) in populations in eastern Maine. The aetiology of these tumours is unknown. We hypothesized that gene expression would be altered in gonadal tumours and that examination of gene expression patterns would provide some information as to the mechanism of tumour development. To investigate this hypothesis, we initiated a broad search for differentially expressed genes using differential display polymerase chain reaction (dd-PCR) to compare RNA from tumour and normal gonadal tissue. We identified two classes of genes whose expression map be altered in the gonadal tumours: genes involved in biosynthetic processes and genes with possible roles in signal transduction. We also investigated the hypothesis that environmental contaminants, such as tetrachlorodibenzo-p-dioxin (TCDD), may play a role in the development of these tumours. To investigate this hypothesis, we performed a short-term exposure of M. arenaria to [H-3]TCDD. Tissues were sampled up to 2 weeks after a 24-h exposure to 10 pptr or 2000 pptr of [H-3]TCDD in the water. Using dd-PCR, we identified potential alterations in expression of genes associated with cell proliferation: heparan sulphate proteoglycan, E3 ubiquitinating enzyme and p68 RNA helicase/initiation factor eIEF-4A. There were no observable histopathological alterations in gonadal or gill tissue from exposed animals. These results suggest possible early changes in gene expression indicative of environmental exposures. C1 Univ Maine, Dept Biochem, Orono, ME 04469 USA. Univ Maine, Sch Marine Sci, Orono, ME 04469 USA. NOAA, Natl Marine Fisheries Serv, NWFS, Seattle, WA 98112 USA. US EPA, Narragansett, RI 02882 USA. RP Van Beneden, RJ (reprint author), Univ Maine, Dept Biochem Microbiol & Mol Biol, 5751 Murray Hall, Orono, ME 04469 USA. OI Rhodes, Linda/0000-0003-4995-9426 NR 34 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1354-750X J9 BIOMARKERS JI Biomarkers PD NOV-DEC PY 1999 VL 4 IS 6 BP 485 EP 491 PG 7 WC Biotechnology & Applied Microbiology; Toxicology SC Biotechnology & Applied Microbiology; Toxicology GA 266AZ UT WOS:000084279600009 ER PT J AU Weetall, HH AF Weetall, HH TI Innovations in biomolecular electronics SO BIOTECHNOLOGY PROGRESS LA English DT Editorial Material C1 Natl Inst Stand & Technol, Adv Technol Program, Gaithersburg, MD 21771 USA. RP Weetall, HH (reprint author), Natl Inst Stand & Technol, Adv Technol Program, Gaithersburg, MD 21771 USA. NR 0 TC 2 Z9 2 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD NOV-DEC PY 1999 VL 15 IS 6 BP 963 EP 963 DI 10.1021/bp9902878 PG 1 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 263JL UT WOS:000084121500001 ER PT J AU Leung, LR Hamlet, AF Lettenmaier, DP Kumar, A AF Leung, LR Hamlet, AF Lettenmaier, DP Kumar, A TI Simulations of the ENSO hydroclimate signals in the Pacific Northwest Columbia River basin SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID REGIONAL CLIMATE MODEL; LATERAL BOUNDARY-CONDITIONS; NORTHERN-HEMISPHERE; OROGRAPHIC PRECIPITATION; SPATIAL VARIABILITY; EL-NINO; PREDICTIONS; TEMPERATURE; SKILL; PARAMETERIZATION AB Natural fluctuations in the atmosphere-ocean system related to the El Nino-Southern Oscillation (ENSO) induce climate variability over many parts of the world that is potentially predictable with lead times from seasons to decades. This study examines the potential of using a model nesting approach to provide seasonal climate and streamflow forecasts suitable for water resources management. Two ensembles of perpetual January simulations were performed with a regional climate model driven by a general circulation model (GCM), using observed climatological sea surface temperature (SST) and the mean SST of the warm ENSO years between 1950 and 1994. The climate simulations were then used to drive a macroscale hydrology model to simulate streamflow. The differences between the two ensembles of simulations are defined as the warm ENSO signals. The simulated hydroclimate signals were compared with observations. The analyses focus on the Columbia River basin in the Pacific Northwest. Results show that the global and regional models simulated a warming over the Pacific Northwest that is quite close to the observations. The models also correctly captured the strong wet signal over California and the weak dry signal over the Pacific Northwest during warm ENSO years. The regional climate model consistently performed better than the GCM in simulating the spatial distribution of regional climate and climate signals. When the climate simulations were used to drive a macroscale hydrology model at the Columbia River basin, the simulated streamflow signal resembles that derived from hydrological simulations driven by observed climate. The streamflow simulations were considerably improved when a simple bias correction scheme was applied to the climate simulations. The coupled regional climate and macroscale hydrologic simulations demonstrate the prospect for generating and utilizing seasonal climate forecasts for managing reservoirs. C1 Pacific NW Lab, Richland, WA 99352 USA. Univ Washington, Dept Civil Engn, Seattle, WA 98195 USA. NOAA, NCEP, EMC, Climate Modeling Branch, Washington, DC USA. RP Leung, LR (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. RI lettenmaier, dennis/F-8780-2011 OI lettenmaier, dennis/0000-0003-3317-1327 NR 37 TC 56 Z9 58 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1999 VL 80 IS 11 BP 2313 EP 2329 DI 10.1175/1520-0477(1999)080<2313:SOTEHS>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 253NG UT WOS:000083562200009 ER PT J AU Squires, D Kirkley, J AF Squires, D Kirkley, J TI Skipper skill and panel data in fishing industries SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID FISHERY; SPECIFICATION; ECONOMETRICS; MANAGEMENT; INPUTS; LABOR AB Skipper skill or managerial ability plays a central role in the harvesting of fish and fishing power. Examining the influences of managerial ability on catch rates, however, may be complicated, since managerial ability is generally unobservable. Using panel data on production activities in the Pacific Coast trawl fishery, we examine the use of the fixed- and random-effects panel data models to depict managerial skill by intervessel differences, representing differences in technical efficiency. The random-effects production model is selected over the fixed-effects model. We conclude that skipper skill is more related to finding fish, dealing with unforseen events, and handling inclement weather than it is to managing the economic inputs. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Coll William & Mary, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP Squires, D (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 37 TC 60 Z9 60 U1 0 U2 9 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD NOV PY 1999 VL 56 IS 11 BP 2011 EP 2018 DI 10.1139/cjfas-56-11-2011 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 253GD UT WOS:000083547400004 ER PT J AU Bentz, DP Snyder, KA AF Bentz, DP Snyder, KA TI Protected paste volume in concrete - Extension to internal curing using saturated lightweight fine aggregate SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE aggregate; concrete; curing; mixture proportioning AB One difficulty in the field use of high-performance concrete is the extensive self-desiccation and autogenous shrinkage that may occur due to its low water/cement ratio and the addition of silica fume to thr mixture proportions. Several researchers have proposed the use of saturated lightweight aggregates to provide "internal" curing for the concrete. In this communication, simple equations are developed to estimate:: the replacement level needed to ensure adequate water for complete curing of the concrete. Additionally, a three-dimensional concrete microstructural model is applied to determine the fraction of the cement paste within a given distance from the lightweight aggregate surfaces. The simulation results are compared with analytical :approximations developed previously. This new concept for curing is similar to the protected paste volume concept conventionally applied to characterizing air void systems in air-entrained concrete.: (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Bentz, DP (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, 100 Bur Dr,Stop 8621, Gaithersburg, MD 20899 USA. RI Chen, Wei/A-5694-2010 NR 17 TC 127 Z9 141 U1 3 U2 33 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 NOV PY 1999 VL 29 IS 11 BP 1863 EP 1867 DI 10.1016/S0008-8846(99)00178-7 PG 5 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 266VH UT WOS:000084320600024 ER PT J AU Harvey, AH Parry, WT AF Harvey, AH Parry, WT TI Keep your "steam tables" up-to-date SO CHEMICAL ENGINEERING PROGRESS LA English DT Article ID WATER; FORMULATION; TEMPERATURE AB Improved methods of calculating water and steam properties can provide more-accurate data for critical applications. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. GE, Power Syst Div, Schenectady, NY 12301 USA. RP Harvey, AH (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 14 TC 4 Z9 4 U1 1 U2 2 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0360-7275 J9 CHEM ENG PROG JI Chem. Eng. Prog. PD NOV PY 1999 VL 95 IS 11 BP 45 EP 49 PG 5 WC Engineering, Chemical SC Engineering GA 258VJ UT WOS:000083859700024 ER PT J AU Wetherald, RT Manabe, S AF Wetherald, RT Manabe, S TI Detectability of summer dryness caused by greenhouse warming SO CLIMATIC CHANGE LA English DT Article ID OCEAN ATMOSPHERE MODEL; TRANSIENT RESPONSES; SULFATE AEROSOLS; GRADUAL CHANGES; CARBON-DIOXIDE; CLIMATE MODELS; CO2; INCREASE; DROUGHT; GASES AB This study investigates the temporal and spatial variation of soil moisture associated with global warming as simulated by long-term integrations of a coupled ocean-atmosphere model conducted earlier. Starting from year 1765, integrations of the coupled model for 300 years were performed for three scenarios: increasing greenhouse gases only, increasing sulfate-aerosol loading only and the combination of both radiative forcings. The integration with the combined radiative forcings reproduces approximately the observed increases of global mean surface air temperature during the 20th century. Analysis of this integration indicates that both summer dryness and winter wetness occur in middle-to-high latitudes of North America and southern Europe. These features were identified in earlier studies. However, in the southern part of North America where the percentage reduction of soil moisture during summer is quite large, soil moisture is decreased for nearly the entire annual cycle in response to greenhouse warming. A similar observation applies to other semi-arid regions in subtropical to middle latitudes such as central Asia and the area surrounding the Mediterranean Sea. On the other hand, annual mean runoff is greatly increased in high latitudes because of increased poleward transport of moisture in the warmer model atmosphere. An analysis of the central North American and southern European regions indicates that the time when the change of soil moisture exceeds one standard deviation about the control integration occurs considerably later than that of surface air temperature for a given experiment because the ratio of forced change to natural variability is much smaller for soil moisture compared with temperature. The corresponding lag time for runoff change is even greater than that of either precipitation or soil moisture for the same reason. Also according to the above criterion, the inclusion of the effect of sulfate aerosols in the greenhouse warming experiment delays the noticeable change of soil moisture by several decades. It appears that observed surface air temperature is a better indicator of greenhouse warming than hydrologic quantities such as precipitation, runoff and soil moisture. Therefore, we are unlikely to notice definitive CO2-induced continental summer dryness until several decades into the 21st century. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Inst Global Change Res FRSGC, Tokyo, Japan. RP Wetherald, RT (reprint author), NOAA, Geophys Fluid Dynam Lab, Forrestal Campus,Forrestal Rd,US Route 1,POB 308, Princeton, NJ 08542 USA. NR 24 TC 69 Z9 84 U1 1 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD NOV PY 1999 VL 43 IS 3 BP 495 EP 511 DI 10.1023/A:1005499220385 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 237PW UT WOS:000082666100001 ER PT J AU Shen, CP Chacon, LC Rosov, N Elder, SH Allman, JC Bartlett, N AF Shen, CP Chacon, LC Rosov, N Elder, SH Allman, JC Bartlett, N TI The structure of R-NiF3, and synthesis, and magnetism of new R(3)over-bar (MNiF6)-Ni-II-F-IV (M = Fe, Co, Cu, Zn), and (MNiF4)-Ni-II-F-II (M = Co, Cu) SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE II FASCICULE C-CHIMIE LA English DT Article DE field-dependent magnetic susceptibility metastability; pseudo-trifluorides; room-temperature preparations ID NICKEL FLUORIDES; SALTS AB Neutron diffraction, at 2 K, of R-NiF3 indicates the formulation approaches (NiNiF6)-Ni-II-F-IV, with Ni-II-F = 1.959(3) and Ni-IV-F = 1.811(3) Angstrom, but 295 K data allow for only a slight increase in any Ni-III. Relatives have been precipitated from liquid anhydrous HF, at less than or equal to 20 degrees C, by adding K2NiF6 to M(SbF6)(2) (M = Co, Cu, Zn) or M(AsF6)(2) (M = Fe). CuNiF6 like NiNiF6 is metastable and loses Fz easily, above 40 degrees C. CuNiF6 is reduced by Xe or C3F6 at -20 degrees C; CoNiF6 Py H-2 at 350 degrees C, each giving pseudo-rutile MNiF4. Magnetic data indicate the dominant formulation is (MNiF6)-Ni-II-F-IV (Ni(IV) low spin d(6)) with field dependence in CoNiF6 (less than or equal to 220 K) and FeNiF6 (less than or equal to 295 K). (C) 1999 Academie des sciences / Editions scientifiques et medicales Elsevier SAS. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Shen, CP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. NR 24 TC 6 Z9 6 U1 1 U2 6 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1387-1609 J9 CR ACAD SCI II C JI Comptes Rendus Acad. Sci. Ser. II C PD NOV PY 1999 VL 2 IS 11-13 BP 557 EP 563 DI 10.1016/S1387-1609(00)88566-7 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 271XN UT WOS:000084620300005 ER PT J AU Kosanke, K Nell, JG AF Kosanke, K Nell, JG TI Standardisation in ISO for enterprise engineering and integration SO COMPUTERS IN INDUSTRY LA English DT Article DE enterprise engineering; enterprise integration; standardisation; process modelling; human role modelling AB The new paradigm of enterprise organisation-extended and virtual enterprises-calls for easy collaboration between partners to exploit market opportunities with varying opportunity windows. Such collaborations can only be achieved if the partner contributions can be easily evaluated by means of process models which represent the relevant parts of the partner operations. However, these models have to be linked to represent the total enterprise of the new partnership and to allow performance evaluation by simulation. To provide the required model inter-operability, the models have to adhere to a common representation for both model enactment and human understandability. International standardisation is a means to provide the necessary model commonality. The paper presents the state of the art in the relevant standardisation and identifies future work in research, development and standardisation. (C) 1999 Elsevier Science B.V. All rights reserved. C1 CIMOSA Assoc, D-71034 Boblingen, Germany. NIST, Gaithersburg, MD 20899 USA. RP Kosanke, K (reprint author), CIMOSA Assoc, Stockholmer Str 7, D-71034 Boblingen, Germany. NR 10 TC 8 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-3615 J9 COMPUT IND JI Comput. Ind. PD NOV PY 1999 VL 40 IS 2-3 BP 311 EP 319 DI 10.1016/S0166-3615(99)00034-2 PG 9 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 251WY UT WOS:000083470400020 ER PT J AU Byrne, RH McElligott, S Feely, RA Millero, FJ AF Byrne, RH McElligott, S Feely, RA Millero, FJ TI The role of pH(T) measurements in marine CO2-system characterizations SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE CO2-system; alkalinity; pH; total inorganic carbon; CO2 partial pressure; fugacity ID CARBON-DIOXIDE SYSTEM; DISSOCIATION-CONSTANTS; PH MEASUREMENTS; WATER COLUMN; BORIC-ACID; SEA-WATER; SEAWATER; THERMODYNAMICS; CONSISTENCY AB Spectrophotometric pH(T) measurements can routinely be obtained with an imprecision on the order of +/- 0.0005 pH(T) units. This level of imprecision is equivalent to an imprecision in total hydrogen ion concentration of +/- 0.1% (where pH(T) = -log[H+], and [H+](T) congruent to [H+] + [HSO4-]). At this level of precision, pH(T) measurements provide an important tool in quality control assessments of other CO2-system parameters (CO2 fugacity, total inorganic carbon, total alkalinity). CO2, fugacities and total alkalinities calculated using measured pH(T) and total inorganic carbon, for the large data set considered in this work, have relative precisions on the order of 0.15 and 0.1%, respectively. The precision of total inorganic carbon calculated via pH(T), and salinity-normalized-alkalinity is on the order of 0.02% or better. In this work, using the NOAA 1992 boreal autumn Equatorial Pacific (EqPac) dataset, it is shown that CO2-system variables calculated via pH(T) can be used to enhance both the precision and accuracy of directly measured parameters. Through the procedures described in this work significant problems were revealed in the initial version of the 1992 NOAA dataset, and the dataset was greatly improved. Additionally, in this work, we revisit CO2-system thermodynamic consistency issues in view of changes in the pH(T), values assigned to tris seawater buffers and consequential changes in the calibration of sulfonephthalein pH(T) indicators. As the principal result of a +0.0047 increase in the pK of meta cresol purple, CO2 fugacity calculations and measurements are in very good agreement for the NOAA 1992 boreal autumn EqPac dataset. We note, as well, that due to a reassignment of the titrant acid concentration used in the NOAA 1992 boreal autumn dataset. measured total alkalinities are in good agreement with total alkalinities calculated from total carbon and pH(T). (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. Merck & Co Inc, W Point, PA 19486 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Byrne, RH (reprint author), Univ S Florida, Dept Marine Sci, 140 7th Ave S, St Petersburg, FL 33701 USA. NR 20 TC 24 Z9 24 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD NOV PY 1999 VL 46 IS 11 BP 1985 EP 1997 DI 10.1016/S0967-0637(99)00031-X PG 13 WC Oceanography SC Oceanography GA 237WK UT WOS:000082679400006 ER PT J AU Paulson, AJ Balistrieri, L AF Paulson, AJ Balistrieri, L TI Modeling removal of Cd, Cu, Pb, and Zn in acidic groundwater during neutralization by ambient surface waters and groundwaters SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MINE DRAINAGE; HUMIC SUBSTANCES; MINING DISTRICT; ORGANIC-MATTER; IRON-OXIDES; ADSORPTION; TRANSPORT; SEDIMENTS; SORPTION; COLORADO AB Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter sta ges of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation. C1 NOAA, Natl Marine Fisheries Serv, NEFSC, James J Howard Lab, Highlands, NJ 07732 USA. Univ Washington, US Geol Survey, Sch Oceanog, Seattle, WA 98195 USA. RP Paulson, AJ (reprint author), NOAA, Natl Marine Fisheries Serv, NEFSC, James J Howard Lab, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 31 TC 35 Z9 36 U1 0 U2 12 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 NOV 1 PY 1999 VL 33 IS 21 BP 3850 EP 3856 DI 10.1021/es9900454 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 251RN UT WOS:000083458800039 ER PT J AU Landrum, PF Kukkonen, J Lydy, MJ Lee, H AF Landrum, PF Kukkonen, J Lydy, MJ Lee, H TI Measuring absorption efficiencies: Some additional considerations SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Letter ID PARTICLE-SIZE FRACTIONS; SEDIMENT; PAH; BIOMAGNIFICATION; BIOAVAILABILITY; ASSIMILATION; DIPOREIA; PCB C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Joensuu, FIN-80101 Joensuu, Finland. Wichita State Univ, Wichita, KS 67260 USA. US EPA, Newport, OR USA. RP Landrum, PF (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 12 TC 0 Z9 0 U1 2 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD NOV PY 1999 VL 18 IS 11 BP 2403 EP 2404 DI 10.1897/1551-5028(1999)018<2403:MAESAC>2.3.CO;2 PG 2 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 248JJ UT WOS:000083271100002 ER PT J AU Hyland, JL Van Dolah, RF Snoots, TR AF Hyland, JL Van Dolah, RF Snoots, TR TI Predicting stress in benthic communities of southeastern US estuaries in relation to chemical contamination of sediments SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE benthos; sediment contamination; sediment quality guidelines; southeastern estuaries; Environmental Monitoring and Assessment Program ID QUALITY GUIDELINES; TOXICITY; FLORIDA; MARINE; BAY AB Matching data on sediment contaminants and macroinfaunal community structure from 231 subtidal stations in southeastern U.S. estuaries were used to develop a framework for evaluating risks of benthic impacts from multiple-contaminant exposure. Sediment contamination was expressed as the mean ratio of individual contaminant concentrations relative to corresponding sediment quality guidelines, that is, to effects range-median (ERM) values, probable effects level (PEL) values, or an aggregate of the two. The probability of a degraded benthos was relatively low in samples with mean ERM quotients less than or equal to 0.020, PEL quotients less than or equal to 0.035, or combined ERM/PEL quotients less than or equal to 0.024. Only 5% of stations within these ranges had degraded benthic assemblages, while 95% had healthy assemblages. A higher probability of benthic impacts was observed in samples with mean ERM quotients >0.058, PEL quotients >0.096, or ERM/PEL quotients >0.077. Seventy-three to 78% of stations with values in these upper ranges had degraded benthic assemblages, while 22 to 27% had healthy assemblages. Only four stations (three with degraded, one with healthy assemblages) had mean ERM or PEL quotients >1.0, which is the beginning of the range associated with a high probability of mortality in short-term laboratory toxicity tests using amphipods. C1 NOAA, Natl Ocean Serv, Ctr Coastal Monitoring & Assessment, Charleston, SC 29422 USA. S Carolina Dept Nat Resources, Marine Resources Res Inst, Charleston, SC 29422 USA. RP Hyland, JL (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Monitoring & Assessment, 217 Ft Johnson Rd,POB 12559, Charleston, SC 29422 USA. NR 26 TC 61 Z9 63 U1 3 U2 5 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD NOV PY 1999 VL 18 IS 11 BP 2557 EP 2564 DI 10.1897/1551-5028(1999)018<2557:PSIBCO>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 248JJ UT WOS:000083271100024 ER PT J AU Blevins, LG Pitts, WM AF Blevins, LG Pitts, WM TI Modeling of bare and aspirated thermocouples in compartment fires SO FIRE SAFETY JOURNAL LA English DT Article ID GAS; TEMPERATURES; COMBUSTION; SCALE AB As part of an effort to characterize the uncertainties associated with temperature measurements in fire environments, models of bare bead, single-shielded aspirated, and double-shielded aspirated thermocouples were developed and used to study the effects of varying the gas and average effective surroundings temperatures on the thermocouple error of each configuration. The models were developed for steady-state conditions and hence provide information about error trends rather than about absolute error values. The models indicate that thermocouples respond differently to changes in effective surroundings temperature in a hot upper-layer than in a relatively cooler lower layer of a room fire. In an upper-layer, for a given gas temperature, the thermocouple error is relatively insensitive to surroundings temperature. In a lower layer, errors which increase rapidly with surroundings temperature are possible. The most extreme errors occur in a lower layer when the gas temperature is low and the surroundings temperature is high. Aspirated thermocouples reduce the errors in both the upper and lower layers of a room fire, but do not eliminate them entirely. The present study is intended to provide fire researchers with a methodology for developing working models of thermocouples which are tailored to their own configurations. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Blevins, LG (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, 100 Bur Dr,Stop 8653, Gaithersburg, MD 20899 USA. NR 30 TC 51 Z9 51 U1 2 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD NOV PY 1999 VL 33 IS 4 BP 239 EP 259 DI 10.1016/S0379-7112(99)00034-X PG 21 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 255GH UT WOS:000083660800001 ER PT J AU Boebel, O Davis, RE Ollitrault, M Peterson, RG Richardson, PL Schmid, C Zenk, W AF Boebel, O Davis, RE Ollitrault, M Peterson, RG Richardson, PL Schmid, C Zenk, W TI The intermediate depth circulation of the western South Atlantic SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOSTROPHIC CIRCULATION; TROPICAL ATLANTIC; TRANSPORTS; OCEAN; PATTERNS; FLOW AB The subsurface oceanic circulation is an important part of the Earth climate system. Subsurface currents traditionally are inferred indirectly from distributions of temperature and dissolved substances, occasionally supplemented by current meter measurements. Neutrally-buoyant floats however, now enable us to obtain for the first time directly measured intermediate depth velocity fields over large areas such as the western South Atlantic. Here, our combined data set provides unprecedented observations and quantification of key flow patterns, such as the Subtropical Gyre return flow (12 Sv; 1 Sverdrup = 10(6)m(3)s(-1)), its bifurcation near the Santos Plateau and the resulting continuous narrow and swift northward intermediate western boundary current (4 Sv). This northward flowing water passes through complex equatorial flows and finally enters into the North Atlantic. C1 Univ Cape Town, Dept Oceanog, ZA-7700 Rondebosch, South Africa. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. IFREMER, Ctr Brest, Lab Phys Oceans, F-29280 Plouzane, France. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Dept Phys Oceanog, Miami, FL 33149 USA. Univ Kiel, Inst Meereskunde, D-24105 Kiel, Germany. RP Boebel, O (reprint author), Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. RI Schmid, Claudia/D-5875-2013; Richard, Pierre/N-6482-2014; OI Schmid, Claudia/0000-0003-2132-4736; Richard, Pierre/0000-0002-0393-9967; Davis, Russ/0000-0003-1903-6313 NR 19 TC 62 Z9 63 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 NOV 1 PY 1999 VL 26 IS 21 BP 3329 EP 3332 DI 10.1029/1999GL002355 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 252DM UT WOS:000083485500031 ER PT J AU Jayaram, S Jayaram, U Wang, Y Tirumali, H Lyons, K Hart, P AF Jayaram, S Jayaram, U Wang, Y Tirumali, H Lyons, K Hart, P TI VADE: A virtual assembly design environment SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Washington State Univ, Pullman, WA 99164 USA. Natl Inst Stand & Technol, Bethesda, MD USA. RP Jayaram, U (reprint author), Washington State Univ, Pullman, WA 99164 USA. NR 13 TC 141 Z9 186 U1 3 U2 14 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV-DEC PY 1999 VL 19 IS 6 BP 44 EP 50 DI 10.1109/38.799739 PG 7 WC Computer Science, Software Engineering SC Computer Science GA 248CD UT WOS:000083257000008 ER PT J AU Zhang, W Lee, JH Chen, Y Bernstein, JB Suehle, JS AF Zhang, W Lee, JH Chen, Y Bernstein, JB Suehle, JS TI Reliability of laser-induced metallic vertical links SO IEEE TRANSACTIONS ON ADVANCED PACKAGING LA English DT Article DE electrical resistance; laser metal link; laser redundancy; reliability; yield enhancement ID CONNECTIONS AB A new method has been proposed to form electrical connections vertically between two levels of metallization by using a commercial pulsed TR laser system. Samples were stressed at accelerated current densities and temperatures. The failure activation energy has been found about 0.66 eV, from which electromigration is identified as a main failure mode. The extrapolated mean time to failure (MTTF) at room temperature and accelerated current density of 3 MA/cm(2) is about 38 years, The dependence of MTTF on laser energy has also been obtained, showing agreement with the resistance dependence on laser energy. Focused ion beam (PTB) cross sections suggest that the laser process-induced voids in the lower Line limit the lifetime of links, Furthermore, a modified structure is proposed to improve the electromigration reliability, From the reliability point of view, this study shows that the laser-induced vertical link has sufficient reliability fur practical implementation. C1 Univ Maryland, Dept Reliabil Engn, College Pk, MD 20742 USA. Lucent Inc, Bell Labs, Orlando, FL 32819 USA. NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Zhang, W (reprint author), Univ Maryland, Dept Reliabil Engn, College Pk, MD 20742 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1521-3323 J9 IEEE TRANS ADV PACK JI IEEE Trans. Adv. Packag. PD NOV PY 1999 VL 22 IS 4 BP 614 EP 619 DI 10.1109/6040.803453 PG 6 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 255RM UT WOS:000083684000012 ER PT J AU Hill, DA AF Hill, DA TI Linear dipole response in a reverberation chamber SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE electric field; linear dipole antenna; received power; reverberation chamber; spatial correlation function ID FIELDS AB A new spatial correlation function is derived for the axial electric field and is compared with the previously known spatial correlation function for the total electric field. The new correlation function is used to determine the average power received by a linear dipole antenna in a reverberation chamber. The result for the average received power agrees with the previous result for an arbitrary impedance-matched antenna derived by the angular spectrum method. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. RP Hill, DA (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 10 TC 36 Z9 37 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1999 VL 41 IS 4 BP 365 EP 368 DI 10.1109/15.809821 PN 1 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 266RX UT WOS:000084314800012 ER PT J AU Wen, MY Mueller, HJ Chai, J Wozniak, WT AF Wen, MY Mueller, HJ Chai, J Wozniak, WT TI Comparative mechanical property characterization of 3 all-ceramic core materials SO INTERNATIONAL JOURNAL OF PROSTHODONTICS LA English DT Article ID FELDSPATHIC PORCELAIN; FRACTURE-TOUGHNESS; FLEXURAL STRENGTH; DENTAL CERAMICS; CROWNS AB Purpose: The biaxial flexural strength and fracture toughness for 3 representative types of ceramic core materials were studied to iii ascertain the ranking of the 3 ceramic types for strength and toughness, and (2) provide clinicians with more information to predict clinical outcomes. The former aim was deemed important in view of the importance of flaw size in the relationship between failure stress and fracture toughness of brittle materials. Materials and Methods: The 3 representative ceramic types included a leucite-reinforced glass, a glass-infiltrated sintered alumina, and a high-purity, high-density alumina. The biaxial flexural strength was measured with the piston-on-3-ball method. The plane-strain fracture toughness was measured with the short-bar chevron-notch method. Results: The biaxial flexural strengths of the high-purity, high-density alumina and glass-infiltrated sintered alumina ceramic core types were significantly higher than that of the leucite-reinforced glass ceramic type. The glass-infiltrated sintered alumina was significantly higher in fracture toughness than the high-purity, high-density alumina type, which was significantly higher than the leucite-reinforced glass. Conclusion: All materials surpassed the minimum strength requirement outlined by the International Standards Organization, and they also had similar strength variability according to their Weibull moduli. The glass-infiltrated sintered alumina and the high-purity, high-density alumina types were significantly stronger and tougher than currently used core materials. However, while the glass-infiltrated sintered alumina had a higher fracture toughness than the high-purity, high-density alumina, it had a lower flexural strength. C1 Northwestern Univ, Sch Dent, Chicago, IL 60611 USA. Natl Inst Stand & Technol, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. Amer Dent Assoc Hlth Fdn, Council Sci Affairs, Evaluat Criteria, Chicago, IL USA. RP Chai, J (reprint author), Northwestern Univ, Sch Dent, 240 E Huron St, Chicago, IL 60611 USA. FU NIDCR NIH HHS [P50 DE 09322] NR 31 TC 28 Z9 29 U1 1 U2 2 PU QUINTESSENCE PUBL CO INC PI CAROL STREAM PA 551 NORTH KIMBERLY DR, CAROL STREAM, IL 60188-1881 USA SN 0893-2174 J9 INT J PROSTHODONT JI Int. J. Prosthodont. PD NOV-DEC PY 1999 VL 12 IS 6 BP 534 EP 541 PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 259YE UT WOS:000083920900009 PM 10815607 ER PT J AU Lemmon, EW Jacobsen, RT AF Lemmon, EW Jacobsen, RT TI Thermodynamic properties of mixtures of R-32, R-125, R-134a, and R-152a SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE equation of state; mixtures; R-32; R-125; R-134a; R-152a; thermodynamic properties ID PLUS PENTAFLUOROETHANE R-32+125; VAPOR-LIQUID-EQUILIBRIUM; PVTX PROPERTIES; REFRIGERANT MIXTURE; DIFLUOROMETHANE; SYSTEM; STATE; COEFFICIENTS; TEMPERATURES; PRESSURES AB A mixture model explicit in Helmholtz energy has been developed that is capable of predicting thermodynamic properties of refrigerant mixtures containing R-32, R-125, R-134a, and R-152a. The Helmholtz energy of the mixture is the sum of the ideal gas contribution, the compressibility (or real gas) contribution, and the contribution from mixing. The contribution from mixing is given by a single equation that is applied to all mixtures used in this work. The independent variables are the density, temperature, and composition. The model may be used to calculate thermodynamic propel ties of mixtures, including dew and bubble point properties and critical points, generally within the experimental uncertainties of the available measured properties. It incorporates the most accurate published equation of state for each pure fluid. The estimated uncertainties of calculated properties are +/-0.25 % in density, +/-0.5% in the speed of sound, and +/-1% in heat capacities. Calculated bubble point pressures are generally accurate to within +/-1%. C1 Univ Idaho, Ctr Appl Thermodynam Studies, Moscow, ID 83844 USA. RP Lemmon, EW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 33 TC 4 Z9 4 U1 0 U2 5 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 1999 VL 20 IS 6 BP 1629 EP 1638 DI 10.1023/A:1022667309962 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 281CB UT WOS:000085139600002 ER PT J AU Krishnan, S Basak, D AF Krishnan, S Basak, D TI Application of high-speed laser polarimetry to noncontact detection of phase transformations in metals and alloys at high temperatures SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE alloys; high temperatures; laser polarimetry; melting; normal spectral emissivity; metals; phase transformations; pulse heating ID EMISSIVITY; MOLYBDENUM AB A high-speed laser polarimetry technique, developed recently for the measurement of normal spectral emissivity of materials at high temperatures, was used to detect solid-solid and solid-liquid phase transformations in metals and alloys in millisecond-resolution pulse-healing experiments. Experiments were performed where normal spectral emissivity at 633 nm was measured simultaneously with surface radiance tempelature, resistance, and/or voltage drop across the specimen. It was observed that a phase transformation, as indicated either by an attest in the specimen radiance temperature or changes in the resistance and/or voltage drop, generally caused a change in normal spectral emissivity. Experiments were conducted on cobalt, iron, hafnium, titanium, and zirconium to detect solid-solid phase transformations. Similar experiments were also performed on niobium. titanium, and the alloy 85titanium-15molybdenum (mass%) to detect solid-liquid phase transformations (melting). C1 Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. Containerless Res Inc, Evanston, IL 60201 USA. RP Basak, D (reprint author), Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. NR 5 TC 4 Z9 4 U1 1 U2 2 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 1999 VL 20 IS 6 BP 1811 EP 1819 DI 10.1023/A:1022674400392 PG 9 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 281CB UT WOS:000085139600017 ER PT J AU Entley, WR Langan, JG Felker, BS Sobolewski, MA AF Entley, WR Langan, JG Felker, BS Sobolewski, MA TI Optimizing utilization efficiencies in electronegative discharges: The importance of the impedance phase angle SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RADIOFREQUENCY DISCHARGES; ELECTRICAL CHARACTERISTICS; REFERENCE CELL; RF DISCHARGES; PLASMA; NF3; OXYGEN; POWER; ARGON; CF4 AB We have investigated the operating conditions that result in the greatest utilization efficiencies (UEs) of NF3, CF4, and C2F6 in a capacitively coupled GEC reference cell. We have also independently measured the rf electrical characteristics and optical emission spectra of the plasmas. To avoid inadvertently attributing changes in the UE, discharge impedance, rf currents, or atomic emission intensities to parasitic losses in the matching network or rf delivery system, the rf generator was adjusted to ensure that the same amount of power was dissipated within each discharge. For the NF3 plasmas, argon was used as a diluent and both the NF3 concentration and reactor pressure were varied. For the CF4 and C2F6 based plasmas, the gas compositions were fixed (86 mol % CF4/O-2 and 50 mol % C2F6/O-2) and the reactor pressure was varied. The greatest NF3 UEs occurred within a narrow range of NF3 partial pressures. The greatest CF4 and C2F6 UEs occurred within a narrow range of reactor pressures. For all mixtures, operating conditions that yielded the highest UEs also yielded the brightest plasmas, the lowest impedance magnitudes, the greatest fraction of current flowing to the grounded electrode, and impedance phase angles within a narrow window centered near phi(pe)=-40 degrees. Within this region, plasma power is most efficiently utilized to dissociate the source gas and excite the atoms that emit light. Collapsed plasmas, observed for high pressure highly electronegative conditions, exhibited very low UEs. At optimal operating conditions the UE of the fluorinated source gases were found to decrease in the order: NF3> C2F6> CF4. The results of this study suggest that the baseline corrected fluorine atom emission intensity (703.7 nm), the magnitude of the discharge impedance, or phase angle of the discharge impedance could be monitored to determine the relative fluorinated source gas UE in an arbitrary plasma reactor as the operating conditions are varied. The concept of an ideal NF3 partial pressure could prove to be a useful strategy to prevent the formation of collapsed plasmas at high reactor pressures while maintaining high NF3UEs. (C) 1999 American Institute of Physics. [S0021- 8979(99)08821-0]. C1 Air Prod & Chem Inc, Allentown, PA 18195 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Entley, WR (reprint author), Air Prod & Chem Inc, 7201 Hamilton Blvd, Allentown, PA 18195 USA. NR 44 TC 13 Z9 13 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 4825 EP 4835 DI 10.1063/1.371449 PG 11 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100015 ER PT J AU Gross, TF AF Gross, TF TI Momentum and energy transfer in the oceanic law of the wall region SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Microstructure Sensors CY OCT 23-25, 1996 CL MT HOOD, OREGON ID TURBULENT BOUNDARY-LAYERS; BED ROUGHNESS; FLOW; LENGTH AB The law of the wall for turbulent boundary layer flow provides an analytic solution for the velocity profile and predictions of the bed shear stress. Mosi formulations and usages of the law of the wall require knowledge of the physical configuration of the seabed, which is input to the theory in the form of the, length scale, the: putative height above the bed where the logarithmic velocity profile goes to zero. Models of current-wave interaction and sediment transport attempt to predict the value of z(0) by modeling a physical length scale active near the bed, that is. the wave boundary layer height and height of particle saltation. Recent work with how through forest canopies has put forth a different approach where the effect of drag on individual trees is to reduce the mean velocity momentum and increase the rate of dissipation of turbulent kinetic energy. Simulations with momentum-energy closure models show that a to is developed that depends on the amplitude of the drag coefficient and the areal extent of the drag elements. Applications of this technique to oceanographic models of sediment transport and wave-current interaction are possible by accounting for a momentum sink and enhanced energy dissipation due to these processes. Oceanic measurements of velocity profiles will not be able to demonstrate the validity of this approach. Direct measurements of energy dissipation and turbulence structure functions will be required to validate the approach. C1 NOAA, NOS, CS Coastal Survey Dev Lab, Silver Spring, MD 20910 USA. RP Gross, TF (reprint author), NOAA, NOS, CS Coastal Survey Dev Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1668 EP 1672 DI 10.1175/1520-0426(1999)016<1668:MAETIT>2.0.CO;2 PN 1 PG 5 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VG UT WOS:000083859400019 ER PT J AU McMillin, LM Divakarla, MG AF McMillin, LM Divakarla, MG TI Effects of possible scan geometries on the accuracy of satellite measurements of water vapor SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MICROWAVE-FREQUENCIES; INCIDENCE ANGLE; MODEL; PERMITTIVITY; IMPACT AB For future satellite instruments, two scan geometries have been proposed: cross-track and conical scanning. With the mixtures of possible instruments, a future sounding suite may consist of all cross track, all conical, or a combination with temperature channels on one and moisture channels on the other This paper evaluates the effect of scan angle on the accuracy of moisture soundings. It is found that, as the scan angle increases from nadir, the accuracy of the moisture soundings near the surface decreases because less of the surface signal reaches the satellite. At the same time, the accuracy of the upper-level sounding increases because the weighting functions become sharper as the angle increases. If a mixed system is required where the temperature and moisture channels have different scan geometries, the best accuracy is obtained if the temperature channels are on a cross-track scanner. The scan angles also affect the number of measurements that are too cloud contaminated to provide accurate meteorological information. A second study shows that the number of radiances that exceed a given error level increases with scan angle. This results in a decrease in coverage for a conical scanning instrument. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Climate Res & Applicat Div, Washington, DC 20233 USA. Res & Data Syst Corp, Greenbelt, MD USA. RP McMillin, LM (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Climate Res & Applicat Div, 4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. RI Divakarla, Murty/E-7936-2011 OI Divakarla, Murty/0000-0002-0399-3381 NR 18 TC 2 Z9 2 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1710 EP 1721 DI 10.1175/1520-0426(1999)016<1710:EOPSGO>2.0.CO;2 PN 2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VH UT WOS:000083859600005 ER PT J AU Lantz, KO Disterhoft, P DeLuisi, JJ Early, E Thompson, A Bigelow, D Slusser, J AF Lantz, KO Disterhoft, P DeLuisi, JJ Early, E Thompson, A Bigelow, D Slusser, J TI Methodology for deriving clear-sky erythemal calibration factors for UV broadband radiometers of the US Central UV Calibration Facility SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RADIATION MONITORING PROGRAM; OZONE MEASUREMENTS; EARTHS SURFACE; ULTRAVIOLET; METER; IRRADIANCE; TRENDS; DEPLETION AB In the United States, there are several federal agencies interested in the effects of UV radiation, which has resulted in the establishment of UV monitoring programs each with their own instrumentation and sites designed to address their specific needs. In 1993, participating agencies of the U.S. Global Change Research Program organized a UV Panel for coordinating the different agencies' programs in order to ensure that UV data are intercalibrated, have common quality assurance and control procedures, and that the efforts among agencies are not duplicated. In order to achieve these goals, in 1994 the UV Panel recommended formation of the U.S. Central UV Calibration Facility (CUCF), which is operated by the Surface Radiation and Research Branch of the Air Resources Laboratory of National and Oceanic Atmospheric Administration. The CUCF is responsible for characterizing and calibrating UV measuring instruments from several U.S. federal agencies. Part of this effort is to calibrate UVB broadband radiometers from these agencies. The CUCF has three Yankee Environmental Systems (YES UVB-I) and three Solar Light (SL 501A) broadband radiometers as reference standards that are routinely calibrated. For the past three years, clear-sky erythema calibration factors were determined for these standard UVB broadband radiometers by using simultaneously measured erythema-weighted irradiance determined during the annual North American Intercomparison. Comparisons between erythemally weighted irradiance calculated spectra supplied by spectroradiometers typically agreed better than +/-2% for solar zenith angles less than 60 degrees. The spectroradiometers were participating in an intercomparison event organized by the National Institute of Standards and Technology and the CUCF. In this article, the calibration methodology is described for transferring the calibration from the spectroradiometers to the CUCF's standard broadband radiometers. The CUCF standard broadband radiometers are used to calibrate UVB broadband radiometers from several U.S. UV monitoring networks. Erythemal calibration factors for the CUCF's YES UVB-1 standard broadband radiometer triad are reported for 1994, 1995, and 1996. Erythemal calibration factors for CUCF's SL 501A standard broadband radiometer triad are reported for 1996. C1 NOAA, Air Resources Lab, SRRB, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Colorado State Univ, USDA UVB Radiat Monitoring Program, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. RP Lantz, KO (reprint author), NOAA, Air Resources Lab, SRRB, R-E-ARx1,325 Broadway, Boulder, CO 80303 USA. NR 34 TC 40 Z9 41 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1736 EP 1752 DI 10.1175/1520-0426(1999)016<1736:MFDCSE>2.0.CO;2 PN 2 PG 17 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VH UT WOS:000083859600007 ER PT J AU Klazura, GE Thomale, JM Kelly, DS Jendrowski, P AF Klazura, GE Thomale, JM Kelly, DS Jendrowski, P TI A comparison of NEXRAD WSR-88D radar estimates of rain accumulation with gauge measurements for high- and low-reflectivity horizontal gradient precipitation events SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Radar-estimated rainfall amounts from the NEXRAD Weather Surveillance Radar precipitation accumulation algorithm were compared with measurements from numerous rain gauges (1639 radar versus gauge comparisons). Storm total rain accumulations from 43 rain events from 10 radar sites were analyzed. These rain events were stratified into two precipitation types: 1) high-reflectivity horizontal gradient storms and 2) low-reflectivity horizontal gradient events. Overall, the radar slightly overestimated rainfall accumulations for high-reflectivity gradient cases and significantly underestimated accumulations for low-reflectivity gradient cases. Varying degrees of range effects were observed for these two types of precipitation. For high-reflectivity gradient cases, the radar underestimated rainfall at the nearest ranges, overestimated at the middle ranges, and had fairly close agreements at the farthest ranges. A much stronger range bias was evident for low-reflectivity gradient cases. The radar underestimated rainfall by at least a factor of 2 in the nearest and farthest ranges, and to a somewhat lesser extent at midranges. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ Oklahoma, Oklahoma Climatol Survey, Norman, OK 73019 USA. Natl Weather Serv, Melbourne, FL USA. Natl Weather Serv, Honolulu, HI USA. RP Klazura, GE (reprint author), ABLE Project Off, 13645 SW Haverhill Rd, Augusta, KS 67010 USA. NR 9 TC 19 Z9 20 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1842 EP 1850 DI 10.1175/1520-0426(1999)016<1842:ACONWR>2.0.CO;2 PN 2 PG 9 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VH UT WOS:000083859600014 ER PT J AU Breon, FM Jackson, D Bates, J AF Breon, FM Jackson, D Bates, J TI Evidence of atmospheric contamination on the measurement of the spectral response of the GMS-5 water vapor channel SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SATELLITES; HUMIDITY AB The GMS-5 geostationary satellite carries a channel centered at 6.7 mu m for the measurement of upper-tropospheric humidity. This channel's spectral response shows structures that are similar to those shown by the atmospheric transmission. This note shows that these structures probably result from water vapor absorption between the calibration source and the instrument while making the response measurement, A corrected filter is proposed after normalization by the inferred atmospheric transmission. The brightness temperatures computed by a radiative transfer model using the spurious response exhibit a warm bias of about 1 K. C1 NOAA, CIRES, ERL, CDC, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Breon, FM (reprint author), NOAA, CIRES, ERL, CDC, R-E-CD,325 Broadway, Boulder, CO 80303 USA. RI Bates, John/D-1012-2009; Jackson, Darren/D-5506-2015; Breon, Francois-Marie/M-4639-2016 OI Bates, John/0000-0002-8124-0406; Jackson, Darren/0000-0001-5211-7866; Breon, Francois-Marie/0000-0003-2128-739X NR 6 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1851 EP 1853 DI 10.1175/1520-0426(1999)016<1851:EOACOT>2.0.CO;2 PN 2 PG 3 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VH UT WOS:000083859600015 ER PT J AU Bodhaine, BA Wood, NB Dutton, EG Slusser, JR AF Bodhaine, BA Wood, NB Dutton, EG Slusser, JR TI On Rayleigh optical depth calculations SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TERRESTRIAL ATMOSPHERE; SCATTERING; WATER; AIR AB Many different techniques are used for the calculation of Rayleigh optical depth in the atmosphere. In some cases differences among these techniques can be important, especially in the UV region of the spectrum and under clean atmospheric conditions. The authors recommend that the calculation of Rayleigh optical depth be approached by going back to the first principles of Rayleigh scattering theory rather than the variety of curve-fitting techniques currently in use. A survey of the literature was conducted in order to determine the latest values of the physical constants necessary and to review the methods available for the calculation of Rayleigh optical depth. The recommended approach requires the accurate calculation of the refractive index of air based on the latest published measurements. Calculations estimating Rayleigh optical depth should be done as accurately as possible because the inaccuracies that arise can equal or even exceed other quantities bring estimated, such as aerosol optical depth, particularly in the UV region of the spectrum. All of the calculations are simple enough to be done easily in a spreadsheet. C1 NOAA, CMDL, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. RP Bodhaine, BA (reprint author), NOAA, CMDL, Cooperat Inst Res Environm Sci, R-E-CG1,325 Broadway, Boulder, CO 80303 USA. NR 24 TC 288 Z9 291 U1 2 U2 39 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1854 EP 1861 DI 10.1175/1520-0426(1999)016<1854:ORODC>2.0.CO;2 PN 2 PG 8 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VH UT WOS:000083859600016 ER PT J AU O'Hare, PAG Watling, K Hope, GA AF O'Hare, PAG Watling, K Hope, GA TI Thermodynamic properties of vanadium silicides. I. Standard molar enthalpy of formation Delta H-f(m)degrees of vanadium disilicide (VSi2) at the temperature 298.15 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE vanadium silicide; fluorine calorimetry; enthalpy of formation; thermodynamic properties; combustion calorimetry ID CALORIMETRY; FLUORINE; SULFUR AB The massic energy of combustion of vanadium disilicide in fluorine according to the reaction VSi2(cr) + (13/2)F-2(g) = VF5(g) + 2SiF(4)(g) has been measured calorimetrically. On the basis of the derived molar enthalpy of reaction and thr standard molar enthalpies of formation Delta(f)H(m)(o) of VF5(g) and SiF4(g), Delta(f)H(m)(o) (VSi2, cr, 298.15 K) = -(133.3 +/- 2.0) KJ.mol(-1) at T = 298.15 K and p = 0.1 MPa. This result is compared with other values of Delta(f)H(m)(o) (VSi2) from the literature. The complete conventional thermodynamic properties of VSi2 are also tabulated between the temperatures 298.15 K and 1950 K. (C) 1999 Academic Press. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Griffith Univ, Nathan, Qld 4111, Australia. RP O'Hare, PAG (reprint author), NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Hope, Gregory/A-7556-2008 OI Hope, Gregory/0000-0003-2694-3456 NR 34 TC 6 Z9 6 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 NOV PY 1999 VL 31 IS 11 BP 1385 EP 1395 DI 10.1006/jcht.1999.0579 PG 11 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 251KN UT WOS:000083445000002 ER PT J AU Masutani, M Leetmaa, A AF Masutani, M Leetmaa, A TI Dynamical mechanisms of the 1995 California floods SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN OSCILLATION; NORTHERN WINTER; PRECIPITATION; ANOMALIES; ATMOSPHERE; RAINFALL; EVENTS; MODEL; FLOW AB The link between El Nino and the California wintertime rainfall has been reported in various studies. During the winter of 1994/95, warm sea surface temperature anomalies (SSTAs) were observed in the central Pacific, and widespread significant flooding occurred in California during January 1995 and March 1995, However, the El Nino-Southern Oscillation alone cannot explain the flooding. In March 1995 California suffered flooding after the warm SSTA over the central Pacific had weakened considerably. During November and December, in spite of El Nino conditions, California was not flooded, and more than two standard deviations above normal SSTA in the North Pacific were observed. A possible link between midlatitude warm SSTA and the timing of the onset of flooding is suspected within the seasonal forecasting community. The climate condition during the northern winter of 1994/95 is described using the National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis data. Diagnostics show the typical El Nino pattern in the seasonal mean and the link between the position of the jet exit and the flooding over California on the intraseasonal timescale. The relationship among California floods, the Pacific jet, tropical rainfall, and SSTA is inferred from results of general circulation model (GCM) experiments with various SSTAs. The results show that the rainfall over California is associated with an eastward extension of the Pacific jet, which itself is associated with enhanced tropical convection over the warm SSTA in the central Pacific. The GCM experiments also show that rainfall over the Indian Ocean can contribute to the weakening of the Pacific jet and to dryness over California. The GCM experiments did not shaw significant impact of North Pacific SSTA, either upon the Pacific jet or upon rainfall over California. The agreement with diagnostics results is discussed. GCM experiments suggest the link between the tropical intraseasonal oscillation (TIO) and the flooding in March in California, since there is a strong TIO component in rainfall over the Indian Ocean. C1 NOAA NWS NCEP EMC, Camp Springs, MD 20746 USA. Res & Data Syst Corp, Greenbelt, MD USA. RP Masutani, M (reprint author), NOAA NWS NCEP EMC, Rm 207,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 25 TC 5 Z9 5 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1999 VL 12 IS 11 BP 3220 EP 3236 DI 10.1175/1520-0442(1999)012<3220:DMOTCF>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 250KX UT WOS:000083388500004 ER PT J AU Vitart, E Anderson, JL Stern, WF AF Vitart, E Anderson, JL Stern, WF TI Impact of large-scale circulation on tropical storm frequency, intensity, and location, simulated by an ensemble of GCM integrations SO JOURNAL OF CLIMATE LA English DT Article ID HURRICANE-TYPE VORTICES; OBSERVATIONAL ANALYSIS; CYCLONE FORMATION; MODEL; CLIMATE; PROJECT AB Tropical storms simulated by a nine-member ensemble of GCM integrations forced by observed SSTs have been tracked by an objective procedure for the period 1980-88. Statistics on tropical storm frequency, intensity, and first location have been produced. Statistical tools such as the chi-square and the Kolmogorov-Smirnov test indicate that there is significant potential predictability of interannual variability of simulated tropical storm frequency, intensity, and first location over most of the ocean basins. The only common point between the nine members of the ensemble is the SST forcing. This implies that SSTs play a fundamental role in model tropical storm frequency, intensity, and first location interannual variability. Although the interannual variability of tropical storm statistics is clearly affected by SST forcing in the GCM, there is also a considerable amount of noise related to internal variability of the model. An ensemble of atmospheric model simulations allows one to filter this noise and gain a better understanding of the mechanisms leading to interannual tropical storm variability. An EOF analysis of local SSTs over each ocean basin and a combined EOF analysis of vertical wind shear, 850-mb vorticity, and 200-mb vorticity have been performed. Over some ocean basins such as the western North Atlantic, the interannual frequency of simulated tropical storms is highly correlated to the first combined EOF, but it is not significantly correlated to the first EOF of local SSTs. This suggests that over these basins the SSTs have an impact on the simulated tropical storm statistics from a remote area through the large-scale circulation as in observations. Simulated and observed tropical storm statistics have been compared. The interannual variability of simulated tropical storm statistics is consistent with observations over the ocean basins where the model simulates a realistic interannual variability of the large-scale circulation. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Princeton Univ, NOAA GFDL, Princeton, NJ USA. RP Vitart, E (reprint author), ECMWF, Shinfield Pk, Reading RG2 9AX, Berks, England. NR 27 TC 32 Z9 33 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1999 VL 12 IS 11 BP 3237 EP 3254 DI 10.1175/1520-0442(1999)012<3237:IOLSCO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 250KX UT WOS:000083388500005 ER PT J AU Wolter, K Dole, RM Smith, CA AF Wolter, K Dole, RM Smith, CA TI Short-term climate extremes over the continental united states and ENSO. Part I: Seasonal temperatures SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION; EL-NINO; PACIFIC; DROUGHT; ASSOCIATIONS; ATMOSPHERE; ORIGINS; EVENTS; WINTER AB This study documents statistical relationships between the El Nino-Southern Oscillation (ENSO) phenomenon and extreme seasonal temperature anomalies over the continental United States. Relationships are examined for El Nino and La Nina conditions for each of the four standard seasons. Two complementary approaches are used. In the first approach, seasonal temperature anomalies are ranked from coldest to warmest over a 100-yr climate division dataset. Mean Southern Oscillation index (SOI) values are then computed for times preceding or concurrent with extreme seasonal temperature anomalies to define regions where relationships between the SOI and seasonal temperature extremes are statistically significant. In the second approach, seasonal extremes in the SOI, which are generally related to El Nino or La Nina, are first identified, and then the numbers of extreme temperature seasons occurring in association with these events are determined. Comparison of the observed number of extreme seasons with the climatologically expected values provides quantitative estimates of how ENSO alters the conditional probability, or risk, of large seasonal temperature anomalies in a given region. The results show that the greatest geographical coverage of statistically significant relationships between ENSO and seasonal temperature extremes occurs in winter and spring, especially with the SOI leading by one season. Certain well-recognized relationships for seasonal temperature anomalies are also confirmed for extreme seasons, such as the association of El Nino conditions with very warm winters over the Pacific Northwest and very cold winters along the Gulf Coast. Other less-discussed relationships also appear, including possible nonlinearities in relationships between El Nino and La Nina events and extremes in autumn temperatures. Some relationships show evidence of secular changes, especially in summer. In some regions and times of year, El Nino and La Nina conditions substantially alter the probabilities of very warm or very cold seasons. For example, over Texas, El Nino conditions in winter almost triple the risk that the subsequent spring will be very cold, while significantly reducing the risk of avery warm spring. In the same region, wintertime La Nina conditions double the risk that the following spring will be very warm, while significantly reducing the likelihood of a very cold spring. Therefore, given the proper ENSO phase, skillful forecasts of regional risks of seasonal temperature extremes appear feasible. C1 NOAA CIRES, Climate Diagnost Lab, Boulder, CO 80303 USA. RP Wolter, K (reprint author), NOAA CIRES, Climate Diagnost Lab, RE CD1,325 Broadway, Boulder, CO 80303 USA. RI Wolter, Klaus/D-5988-2015; Smith, Catherine/H-5055-2016 OI Smith, Catherine/0000-0003-2687-6046 NR 31 TC 29 Z9 31 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 PY 1999 VL 12 IS 11 BP 3255 EP 3272 DI 10.1175/1520-0442(1999)012<3255:STCEOT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 250KX UT WOS:000083388500006 ER PT J AU Janowiak, JE Xie, PP AF Janowiak, JE Xie, PP TI CAMS-OPI: A global satellite-rain gauge merged product for real-time precipitation monitoring applications SO JOURNAL OF CLIMATE LA English DT Article AB A method has been developed to produce real-time rain gauge-satellite merged analyses of global monthly precipitation. A dataset of these analyses spans the period from January 1979 to the present, which is sufficiently long to allow the computation of reasonably stable base period means from which departures from "normal" can be computed. The dataset is used routinely for global precipitation monitoring purposes at the National Oceanic and Atmospheric Administration/National Weather Service/National Centers for Environmental Prediction/Climate Prediction Center, is updated monthly, and is available via the Internet. C1 NCEP NWS NOAA, Climate Predict Ctr, WWBG, NOAA, Camp Springs, MD 20746 USA. Res Data & Syst Corp, Greenbelt, MD USA. RP Janowiak, JE (reprint author), NCEP NWS NOAA, Climate Predict Ctr, WWBG, NOAA, WNP52,Room 605,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 13 TC 126 Z9 128 U1 1 U2 8 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 PY 1999 VL 12 IS 11 BP 3335 EP 3342 DI 10.1175/1520-0442(1999)012<3335:COAGSR>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 250KX UT WOS:000083388500012 ER PT J AU Silver, J Mi, ZH Takamoto, K Bungay, P Brown, J Powell, A AF Silver, J Mi, ZH Takamoto, K Bungay, P Brown, J Powell, A TI Controlled formation of low-volume liquid pillars between plates with a lattice of wetting patches by use of a second immiscible fluid SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE microdroplets; arrays; wetting patches; Surface Evolver ID SURFACES AB We describe a method for forming an array of microdroplets between two plates, at least one of which is patterned with a lattice of wetting patches, using a second immiscible fluid to control droplet formation. The method may be useful for performing multiple, small-volume biochemical reactions in parallel, We analyze the forces responsible for droplet formation, describe results of a computer simulation using Surface Evolver, and derive an analytic criterion for droplet formation in terms of the contact angles of the droplet:second fluid interface on the wetting patches and surrounding surface, the diameter of the wetting patches, the distance between wetting patches, and the distance between the plates. (C) 1999 Academic Press. C1 NIAID, Mol Microbiol Lab, NIH, Bethesda, MD 20892 USA. NIH, Bioengn & Phys Sci Program, Bethesda, MD 20892 USA. Cytonix Corp, Beltsville, MD 20705 USA. Natl Inst Stand & Technol, Met Div 855, Gaithersburg, MD 20899 USA. RP Silver, J (reprint author), NIAID, Mol Microbiol Lab, NIH, Bldg 4-338, Bethesda, MD 20892 USA. NR 12 TC 17 Z9 17 U1 1 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD NOV 1 PY 1999 VL 219 IS 1 BP 81 EP 89 DI 10.1006/jcis.1999.6422 PG 9 WC Chemistry, Physical SC Chemistry GA 246LM UT WOS:000083165300009 ER PT J AU Lippiatt, BC AF Lippiatt, BC TI Selecting cost-effective green building products: BEES approach SO JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT-ASCE LA English DT Article AB The Building for Environmental and Economic Sustainability (BEES) tool implements a rational, systematic technique for selecting cost-effective green building products. The technique is based on consensus standards and designed to be practical, flexible, and transparent. The Windows-based decision support software, aimed at designers, builders, and product manufacturers, includes actual environmental and economic performance data for 24 building products across a range of functional applications. BEES measures the environmental performance of building products using the environmental Life-cycle assessment approach specified in the latest versions of ISO 14000 draft standards. The approach is based on the belief that all stages in the Life of a product generate environmental impacts and must be analyzed. The stages include raw material acquisition, manufacture, transportation, installation, use, and waste management. Economic performance is measured using the ASTM standard life-cycle cost method. The technique includes the costs over a given study period of initial investment, replacement, operation, maintenance and repair, and disposal. Environmental and economic performance are combined into an overall performance measure using the ASTM standard for multiattribute decision analysis. C1 US Dept Commerce, Off Appl Econ, Bldg & Fire Res Lab, Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lippiatt, BC (reprint author), US Dept Commerce, Off Appl Econ, Bldg & Fire Res Lab, Natl Inst Stand & Technol, 100 Bur Dr,Stop 8603, Gaithersburg, MD 20899 USA. NR 19 TC 39 Z9 40 U1 0 U2 6 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9364 J9 J CONSTR ENG M ASCE JI J. Constr. Eng. Manage.-ASCE PD NOV-DEC PY 1999 VL 125 IS 6 BP 448 EP 455 DI 10.1061/(ASCE)0733-9364(1999)125:6(448) PG 8 WC Construction & Building Technology; Engineering, Industrial; Engineering, Civil SC Construction & Building Technology; Engineering GA 256KK UT WOS:000083724300008 ER PT J AU Drexler, ES AF Drexler, ES TI Reliability of a flip-chip package thermally loaded between-55 degrees C and 125 degrees C SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 128th TMS Annual Meeting CY FEB 28-MAR 04, 1999 CL SAN DIEGO, CA SP Min, Met & Mat Soc DE deformation; electron-beam moire; flip-chip; flip-chip-on-board; moire; PBGA; solderball fatigue; solder mask; strain; thermal load ID MOIRE AB Low-temperature reliability of flip-chip plastic ball-grid array packages is a concern for manufacturers. Packages that perform well when thermally cycled from 20 to 120 degrees C fail at an unacceptable rate when the temperature is extended down to -55 degrees C. Electron-beam moire was used to study local deformations in a flip-chip package and the interactions among the various materials found within the package. The specimen was subjected to a total often complete thermal cycles from -55 to 125 degrees C over several nonconsecutive days. Debonding initiated between the solderball and the solder mask where that interface meets the printed circuit board. Deformation was also induced within the solderball, becoming more pronounced with more thermal cycles. Out-of-plane strains appear to be the dominant mechanism for deformation at this location. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 16 TC 10 Z9 10 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0361-5235 EI 1543-186X J9 J ELECTRON MATER JI J. Electron. Mater. PD NOV PY 1999 VL 28 IS 11 BP 1150 EP 1157 DI 10.1007/s11664-999-0150-7 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 255DH UT WOS:000083653900003 ER PT J AU Bell, GW Buckel, JA Stoner, AW AF Bell, GW Buckel, JA Stoner, AW TI Effects of alternative prey on cannibalism in age-1 bluefish SO JOURNAL OF FISH BIOLOGY LA English DT Article DE selectivity; switching; cannibalism; alternative prey; density dependent; bluefish; Pomatomus salatrix; Atlantic silverside; Menidia menidia ID THE-YEAR BLUEFISH; POLLOCK THERAGRA-CHALCOGRAMMA; EASTERN BERING SEA; POMATOMUS-SALTATRIX; WALLEYE POLLOCK; JUVENILE BLUEFISH; CAPTURE SUCCESS; SIZE-SELECTION; PREDATION; RECRUITMENT AB Age-1 bluefish Pomatomus saltatrix were offered both age-0 bluefish and age-1 Atlantic silversides Menidia menidia in the following proportions: 0 : 1.0, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, 1.0 : 0. Atlantic silversides were consumed in greater proportion than offered throughout all treatments suggesting strong selection for silversides. There was no evidence of prey-m itching. The behavioral processes leading to age-1 bluefish selection of Atlantic silversides was investigated. The proportion of attacks on each prey species was distributed randomly, or slightly higher on age-0 bluefish; however, capture success was greater on silversides than on age-0 bluefish prey. Therefore, age-1 bluefish did not actively select for silversides and the observed selection pattern is a result of passive processes. These findings suggest that prey snitching between age-0 bluefish and an alternative prey probably does not act as a stabilizing mechanism in the bluefish population and confirm the importance of capture success in determining piscivore selectivity patterns. (C) 1999 The Fisherics Society of the British Isles. C1 NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. RP Buckel, JA (reprint author), NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 33 TC 10 Z9 10 U1 0 U2 2 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 1999 VL 55 IS 5 BP 990 EP 1000 DI 10.1006/jfbi.1999.1102 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 256RJ UT WOS:000083739100006 ER PT J AU Richie, KL Goldsborough, MD Darfler, MM Benzinger, EA Lovekamp, ML Reeder, DJ O'Connell, CD AF Richie, KL Goldsborough, MD Darfler, MM Benzinger, EA Lovekamp, ML Reeder, DJ O'Connell, CD TI Long PCR for VNTR analysis SO JOURNAL OF FORENSIC SCIENCES LA English DT Article; Proceedings Paper CT 48th Annual Meeting of the American-Academy-of-Forensic-Sciences CY FEB 19-24, 1996 CL NASHVILLE, TENNESSEE SP Amer Acad Forens Sci DE forensic science; RFLP; DNA typing; Long Polymerase Chain Reaction ID CHAIN-REACTION; HUMAN DNA; AMPLIFICATION; POLYMORPHISMS; PYNH24 AB The Polymerase Chain Reaction (PCR) has revolutionized the analysis of DNA from a variety of sources. With its sensitivity and ability to amplify degraded DNAs and small quantities of samples, coupled with fast turn-around-time, PCR is often the analytical method of choice for DNA profiling in forensic laboratories. RFLP methods, while requiring larger amounts of high molecular weight DNA and needing approximately 6-8 weeks of analytical time, still provide a higher power of discrimination per locus than that achieved using the loci currently available for PCR. The combination of both RFLP and PCR would be advantageous for some applications. A new technique, Long PCR, allows for the effective amplification of long DNA targets from approximately 0.5 kb to >20 kb of genomic DNA. Currently, several Long PCR systems are commercially available. Using a Taq/Pyrococcus DNA polymerase enzyme system and DNA isolated from bloodstains, we have successfully amplified 1-20 ng of Chelex-extracted DNA, an amount commonly used in Amp-FLP technology. The robustness of Long PCR in comparison to RFLP was also examined through the use of partially degraded blood samples. Long PCR was then used to amplify both D2S44 and D5S110 RFLP loci. Although all D2 and D5 alleles were detected, the larger alleles were amplified at significantly lower levels than the smaller alleles. C1 NIST, Biotechnol Div MS 8311, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Life Technol Inc, Div Res & Dev, Rockville, MD USA. Ohio Bur Criminal Identificat & Investigat, London, OH USA. New Mexico Dept Publ Safety Crime Lab, Santa Fe, NM USA. RP Richie, KL (reprint author), NIST, Biotechnol Div MS 8311, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 23 TC 2 Z9 4 U1 0 U2 2 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 1999 VL 44 IS 6 BP 1176 EP 1185 PG 10 WC Medicine, Legal SC Legal Medicine GA 293BA UT WOS:000085830600008 PM 10582357 ER PT J AU Kumar, AR Zhang, ZM Boychev, VA Tanner, DB Vale, LR Rudman, DA AF Kumar, AR Zhang, ZM Boychev, VA Tanner, DB Vale, LR Rudman, DA TI Far-infrared transmittance and reflectance of YBa2Cu3O7-delta films on Si substrates SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Joint ASME/IMECE Meeting CY 1998 CL ANAHEIM, CALIFORNIA SP ASME, IMECE DE experimental; heat transfer; interferometry; radiation; thin films ID SUPERCONDUCTING THIN-FILMS; OPTICAL-CONSTANTS; SCATTERING; CONDUCTIVITY; DETECTORS; SPECTRA AB The transmittance and reflectance of superconductive YBa2Cu3O7-delta (YBCO) thin films deposited on Si substrates have been measured in the far-infrared frequency region from 10 to 100 cm(-1) (wavelength from 1000 to 100 mu m) at temperatures between 10 and 300 K. The effects of interference, optical resonance, and antireflection on the radiative properties of high-temperature superconducting (HTSC) films are observed and quantitatively analyzed. Furthermore, we have measured the reflectance of the HTSC film-substrate composites for radiation incident on the substrate side (backside reflectance) for the first time. The backside reflectance increases significantly from the normal state to the superconducting state at certain frequencies; this experimentally demonstrates that HTSC films can be used to build far-infrared intensity modulators. The complex refractive index of the YBCO films is determined from the measured transmittance using the Drude model in the normal state and a two-fluid model in the superconducting state. The complex refractive index obtained from this study is useful for various applications of YBCO films, including radiation modulators, detectors, and Fabry-Perot resonators. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Zhang, ZM (reprint author), Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. RI kumari, uttara/P-6779-2016 OI kumari, uttara/0000-0001-9628-4770 NR 38 TC 8 Z9 8 U1 1 U2 10 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1999 VL 121 IS 4 BP 844 EP 851 DI 10.1115/1.2826074 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 261HD UT WOS:000084003000010 ER PT J AU Adams, VH Joshi, Y Blackburn, DL AF Adams, VH Joshi, Y Blackburn, DL TI Three-dimensional study of combined conduction, radiation, and natural convection from discrete heat sources in a horizontal narrow-aspect-ratio enclosure SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE conjugate heat transfer; enclosure flows; natural convection AB Three-dimensional natural convention flow and heat transfer were numerically studied for a three-by-three array of discrete protruding heat sources on a horizontal substrate in an air-filled, rectangular, narrow-aspect-ratio enclosure with length, width, and height ratio of 6:6:1. The governing equations for natural convection in air, coupled with conjugate conduction and radiation within the enclosure were solved using a finite volume method. The study examines the complex thermal interactions between the heat sources, substrate, and enclosure walls as affected by the thermal conductance of the walls and substrate with the intent of determining which physical effects and level of detail are necessary to accurately predict thermal behavior of discretely heated enclosures. The influence of radiation on the overall heat transfer is given particular attention. The three dimensionality of the problem was evident in the overall flow characteristics and in the convective heat transfer edge effects on the heat source surfaces. Excellent agreement between temperature predictions on the hear sources and substrate and experimental measurements was obtained for modified Rayleigh numbers in the range of 9.7 X 10(5) to 1.6 x 10(7). C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Adams, VH (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. NR 22 TC 22 Z9 22 U1 1 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1999 VL 121 IS 4 BP 992 EP 1001 DI 10.1115/1.2826091 PG 10 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 261HD UT WOS:000084003000027 ER PT J AU Hard, JJ Winans, GA Richardson, JC AF Hard, JJ Winans, GA Richardson, JC TI Phenotypic and genetic architecture of juvenile morphometry in Chinook salmon SO JOURNAL OF HEREDITY LA English DT Article ID SOUTHERN BRITISH-COLUMBIA; COHO SALMON; ONCORHYNCHUS-KISUTCH; RAINBOW-TROUT; BODY MORPHOLOGY; ATLANTIC SALMON; QUANTITATIVE GENETICS; NATURAL-POPULATIONS; WILD POPULATIONS; PACIFIC SALMON AB Juvenile morphology can affect fitness of salmonids in nature, but the genetic basis for morphometry in salmonids is poorly understood. We mated chinook salmon in a half-sib/full-sib breeding design to determine the genetic and environmental components of morphometric variation. We characterized body size and shape in 20 progeny from each of 95 full-sib families by digitizing 30 landmarks on lateral, dorsal, and ventral images of the body form, and estimated genetic and environmental components of variance for 12 truss elements constructed from the landmarks. We then conducted principal component analyses of the phenotypic, genetic, and environmental covariance matrices for these elements. Most (83%) of the phenotypic variation in morphometry was expressed along axes of allometry, shape change during smoltification, and a three-dimensional body shape contrast (head width versus lateral profile depth). All morphometric traits showed substantial additive genetic variation and were highly correlated genetically as well as phenotypically, Principal components of genetic variation in morphometry resembled the phenotypic principal components. The analyses also detected strong environmental effects on body shape and indicated two distinct morphometric types arising from maternal or environmental sources. The results provide evidence for genetic coordination of body size and shape, which would be expected if these characters are tightly coupled developmentally. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Hard, JJ (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM jeff.hard@noaa.gov RI Hard, Jeffrey/C-7229-2009; Sanchez Gonzalez, Jorge/A-9285-2009 NR 65 TC 33 Z9 35 U1 2 U2 8 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 1999 VL 90 IS 6 BP 597 EP 606 DI 10.1093/jhered/90.6.597 PG 10 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 259ZE UT WOS:000083923200002 ER PT J AU Yamaura, K Huang, Q Erwin, RW Lynn, JW Cava, RJ AF Yamaura, K Huang, Q Erwin, RW Lynn, JW Cava, RJ TI A study of structure, electric and magnetic properties of the new layered cobalt oxides Sr2Y1-xCaxCo2O7-z SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors (MOS-99) CY JUL 28-AUG 02, 1999 CL ROYAL INST TECHNOL, STOCKHOLM, SWEDEN SP Royal Inst Technol, Royal Swedish Acad Sci, Swedish Nat Sci, Engn Sci Res Councils, SAS, Gran Gustafsson Fdn, City of Stockholm HO ROYAL INST TECHNOL AB The crystal structure of Sr2Y0.8Ca0.2Co2O6 is orthorhombic below 270 K (Immm, a = 3.84029(7) Angstrom, b = 3.80691(6) Angstrom and c = 19.4980(3) Angstrom at 20 K), transformed from tetragonal (I4/mmm, a = 3.82765(6) Angstrom and c = 19.5795(3) Angstrom) at 295 K. The crystal structure distortion is accompanied by an anomalous temperature dependence of the degree of buckling of the CoO2 plane and is correlated with the development of anisotropic antiferromagnetic ordering of magnetic moments (2.93(2) mu(B) per Co at 20 K). A magnetically glassy state below about 35 K and variable range hopping conduction below about 64 K for Sr2Y1-xCaxCo23.4+O7-z (0.2 less than or equal to x less than or equal to 0.5, 0.21 less than or equal to z less than or equal to 0.38) were found by magnetic susceptibility and electrical resistivity measurements. C1 Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08540 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Yamaura, K (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. NR 11 TC 1 Z9 1 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD NOV PY 1999 VL 117 IS 3-4 BP 849 EP 853 DI 10.1023/A:1022534420416 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 267RW UT WOS:000084373900111 ER PT J AU Josell, D Bonevich, JE Shao, I Cammarata, RC AF Josell, D Bonevich, JE Shao, I Cammarata, RC TI Measuring the interface stress: Silver/nickel interfaces SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID X-RAY-DIFFRACTION; THIN-FILMS; MULTILAYERS; SURFACE AB Interface stress is a surface thermodynamics quantity associated with the reversible work of elastically straining an internal solid interface. In a multilayered thin film, the combined effect of the interface stress of each interface results in an in-plane biaxial volume stress acting within the layers of the film that is inversely proportional to the bilayer thickness. We calculated the interface stress of an interface between {111} textured Ag and Ni on the basis of direct measurements of the dependence of the in-plane elastic strains on the bilayer thickness. The strains were obtained using transmission x-ray diffraction. Unlike previous studies of this type, we used freestanding films so that there was no need to correct for intrinsic stresses resulting from forces applied by the substrate that can lead to large uncertainties of the calculated interface stress value. Based on the lattice parameters of the bulk, pure elements, an interface stress of -2.02 +/- 0.26 N/m was calculated using the x-ray diffraction results from films with bilayer thicknesses greater than 5 nm. This value is somewhat smaller than previous measurements obtained from as-deposited films supported by substrates. For smaller bilayer thicknesses the apparent interface stress becomes smaller in magnitude, possibly due to a loss of layering in the specimens. C1 NIST, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Baltimore, MD USA. RP Josell, D (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 17 TC 28 Z9 28 U1 0 U2 7 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1999 VL 14 IS 11 BP 4358 EP 4365 DI 10.1557/JMR.1999.0590 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 257FC UT WOS:000083771000035 ER PT J AU Goeller, PT Boyanov, BI Sayers, DE Nemanich, RJ Myers, AF Steel, EB AF Goeller, PT Boyanov, BI Sayers, DE Nemanich, RJ Myers, AF Steel, EB TI Germanium segregation in the Co/SiGe/Si(001) thin film system SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID RELAXED SIGE MATERIAL; SOLID-STATE REACTION; COBALT DISILICIDE; SI1-XGEX ALLOYS; SILICON; TITANIUM; GROWTH; COSI2; STABILITY; SI(100) AB Cobalt disilicide contacts to silicon-germanium alloys were formed by direct deposition of pure cobalt metal onto silicon-germanium films on Si(001) substrates. Segregation of germanium was observed during the reaction of the cobalt with the silicon-germanium alloy. The nature of the Ge segregation was studied by transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. In the case of cobalt films deposited onto strained silicon-germanium films, the Ge segregation was discovered to be in the form of Ge-enriched Si1-xGex regions found at the surface of the film surrounding CoSi and CoSi2 grains. In the case of cobalt films deposited onto relaxed silicon-germanium films, the Ge segregation was dependent on formation of CoSi2. In samples annealed below 800 degrees C, where CoSi was the dominant silicide phase, the Ge segregation was similar in form to the strained Si1-xGex case. In samples annealed above 800 degrees C, where CoSi2 was the dominant silicide phase, the Ge segregation was also in the form of tetrahedron-shaped, Ge-enriched, silicon-germanium precipitates, which formed at the substrate/silicon-germanium film interface and grew into the Si substrate. A possible mechanism for the formation of these precipitates is presented based on vacancy generation during the silicidation reaction coupled with an increased driving force for Ge diffusion due to silicon depletion in the alloy layer. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. NIST, Microanal & Surface Div, Gaithersburg, MD 20899 USA. RP Nemanich, RJ (reprint author), N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. NR 57 TC 20 Z9 20 U1 0 U2 1 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 NOV PY 1999 VL 14 IS 11 BP 4372 EP 4384 DI 10.1557/JMR.1999.0592 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 257FC UT WOS:000083771000037 ER PT J AU Kirklin, DR AF Kirklin, DR TI Properties of materials and systems of importance to environmental fates and remediation. III. Review of previous thermodynamic property values for chromium and some of its compounds SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE aqueous solutions; chromium; thermodynamic properties ID HYDROLYSIS; ENTHALPY; METAL; IONS AB Twenty-seven (27) crystalline and aqueous chromium species from the NBS Tables of Chemical Thermodynamic Properties were selected based upon their possible importance to environmental fate and remediation processes. Their NBS files were studied to determine the sources of information and the methodology used to determine the NBS selected thermodynamic values, The NBS tables for chromium were compiled in 1966. A literature search was performed to determine the existence of additional data for these species, Documentary data are presented for the thermodynamic properties of these twenty-seven (27) species. (C) 1999 American Institute of Physics and American Chemical Society. [S0047-2689(99)00205-6]. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Kirklin, DR (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 123 TC 5 Z9 5 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD NOV-DEC PY 1999 VL 28 IS 6 BP 1675 EP 1704 DI 10.1063/1.556053 PG 30 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 298TF UT WOS:000086154700003 ER PT J AU Mohr, PJ Taylor, BN AF Mohr, PJ Taylor, BN TI CODATA recommended values of the fundamental physical constants: 1998 SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE CODATA; conversion factors; data analysis; electrical units; fundamental constants; Josephson effect; least-squares adjustment; quantum electrodynamics; quantum Hall effect ID ANOMALOUS MAGNETIC-MOMENT; QUANTIZED HALL RESISTANCE; FINE-STRUCTURE CONSTANT; VACUUM-POLARIZATION CONTRIBUTION; HIGH-RESOLUTION SPECTROSCOPY; DEUTERON BINDING-ENERGY; NEWTONIAN GRAVITATIONAL CONSTANT; MUONIUM HYPERFINE-STRUCTURE; 1S-2S TRANSITION FREQUENCY; PROTON GYROMAGNETIC RATIO AB This paper gives the 1998 self-consistent set of values of the basic constants and conversion factors of physics acid chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. Further, it describes in detail the adjustment of the values of the subset of constants on which the complete 1998 set of recommended values is based. The 1998 set replaces its immediate predecessor recommended by CODATA in 1986. The new adjustment, which takes into account all of the data available through 31 December 1998, is a significant advance over its 1986 counterpart. The standard uncertainties (i.e., estimated standard deviations) of the new recommended values are in most cases about 1/5 to 1/12 and in some cases 1/160 times the standard uncertainties of the corresponding 1986 values. Moreover, in almost all cases the absolute values of the differences between the 1998 values and the corresponding 1986 values are less than twice the standard uncertainties of the 1986 values. The new set of recommended values is available on the World Wide Web at physics.nist.gov/constants. (C) 1999 American Institute of Physics and American Chemical Society. [S0047-2689(00)00301-9]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM peter.mohr@nist.gov; barry.taylor@nist.gov NR 686 TC 218 Z9 221 U1 1 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0047-2689 EI 1529-7845 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD NOV-DEC PY 1999 VL 28 IS 6 BP 1713 EP 1852 DI 10.1063/1.556049 PG 140 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 298TF UT WOS:000086154700005 ER PT J AU Cage, ME Jeffery, A Matthews, J AF Cage, ME Jeffery, A Matthews, J TI Equivalent electrical circuit representations of AC quantized Hall resistance standards SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ac quantum Hall effect; equivalent electrical circuits; intrinsic impedance standard; multi-series connections; quantized Hall resistance; parasitic impedances AB We use equivalent electrical circuits to analyze the effects of large parasitic impedances existing in all sample probes on four-terminal-pair measurements of the ac quantized Hall resistance R-H. The circuit components include the externally measurable parasitic capacitances, inductances, lead resistances, and leakage resistances of ac quantized Hall resistance standards, as well as components that represent the electrical characteristics of the quantum Hall effect device (QHE). Two kinds of electrical circuit connections to the QHE are described and considered: single-series "offset" and quadruple-series. (We eliminated other connections in earlier analyses because they did not provide the desired accuracy with all sample probe leads attached at the device.) Exact, but complicated, algebraic equations are derived for the currents and measured quantized Hail voltages for these two circuits. Only the quadruple-series connection circuit meets our desired goal of measuring R-H for both ac and de currents with a one-standard-deviation uncertainty of 10(-8) R-H or less during the same cool-down with all leads attached at the device. The single-series "offset" connection circuit meets our other desired goal of also measuring the longitudinal resistance R-x for both ac and de currents during that same cool-down. We will use these predictions to apply small measurable corrections, and uncertainties of the corrections, to ac measurements of R-H in Order to realize an intrinsic ac quantized Halt resistance standard of 10(-8) R-H uncertainty or less. C1 NIST, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Cage, ME (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 26 TC 2 Z9 2 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1999 VL 104 IS 6 BP 529 EP 556 DI 10.6028/jres.104.033 PG 28 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 293YK UT WOS:000085882700001 ER PT J AU Siewert, TA Vigliotti, DP Dirling, LB McCowan, CN AF Siewert, TA Vigliotti, DP Dirling, LB McCowan, CN TI Performance verification of impact machines for testing plastics SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE aluminum; Charpy impact test; Izod impact test; plastics; steel; verification; V-notch AB Valid comparison of impact test energies reported by various organizations and over time depends on consistent performance of impact test machines. This paper investigates the influence of various specimen and test parameters on impact energies in the 1 J to 2 J range for both Charpy V-notch and Izod procedures, leading toward the identification of a suitable material for use in a program to verify machine performance. We investigated the influences on the absorbed energy of machine design, rest material, specimen cross sectional area, and machine energy range. For comparison to published round robin data on common plastics, this study used some common metallic alloys, including those used in the international verification program for metals impact machines and in informal calibration pro-grams of tensile machines. The alloys that were evaluated include AISI type 4340 steel, and five aluminum alloys: 2014-T6, 2024-T351, 2219-T87, 6061-T6, and 7075-T6. We found that certain metallic alloys have coefficients of variation comparable to those of the best plastics that are reported in the literature. Also, we found that the differences in absorbed energy between two designs of machines are smaller than the differences that can be attributed to the specimens alone. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Siewert, TA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 8 TC 0 Z9 0 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 1999 VL 104 IS 6 BP 557 EP 565 DI 10.6028/jres.104.034 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 293YK UT WOS:000085882700002 ER PT J AU Gray, MM AF Gray, MM TI Applicability of metrology to information technology SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE function point metrics; information technology; software metrics AB In 1959 the Director of the National Bureau of Standards declared "The emergence of science and technology as the paramount concern of the Nation in the 20(th) century...demanded the highest order of measurement competence, in order to provide the standards and measurement techniques on which maintenance of scientific progress depended." Since 1959, information technology has emerged as having a global impact on all facets of industry. However, the "standards and measurement techniques" needed to maintain the scientific progress of information technology into the next century may not be in place. This paper discusses the current state of software metrics. C1 NIST, Gaithersburg, MD 20899 USA. RP Gray, MM (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 35 TC 3 Z9 3 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1999 VL 104 IS 6 BP 567 EP 578 DI 10.6028/jres.104.035 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 293YK UT WOS:000085882700003 ER PT J AU Zhang, W AF Zhang, W TI Formulation of multiple diffraction by trees and buildings for radio propagation predictions for local multipoint distribution service SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE building; local multipoint distribution service (LMDS); microwave propagation; multiple diffraction; tree; vegetation; wireless communications ID MODEL; UTD; EDGE AB This paper presents a closed-form expression for multiple forward diffraction by rows of tree canopies and buildings applicable to the propagation predictions at centimeter and millimeter wavelengths for local multipoint distribution service (LMDS). The expression is derived from the uniform geometrical theory of diffraction and physical optics, as well as from some existing models for vegetation and buildings. When the transmitter antennas are sufficiently high, the attenuation of the buildings varies around the value of free space and the building effect is negligible, because a line-of-sight (LOS) propagation path between transmitter and over building-rooftop receiver antennas exists and plays a major role. The tree canopies which extend above the building rooftop heights block the LOS propagation path and cause additional signal attenuation. An existing study of the LMDS radio channel based on measurements came to the same conclusion. The attenuation effect of the buildings is significant if the transmitter antennas are not high enough. C1 NIST, Gaithersburg, MD 20899 USA. RP Zhang, W (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1999 VL 104 IS 6 BP 579 EP 585 DI 10.6028/jres.104.036 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 293YK UT WOS:000085882700004 ER PT J AU Subbarao, MW AF Subbarao, MW TI Dynamic power-conscious routing for MANETs: An initial approach SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE decentralized networks; dynamic routing; mobile ad hoc networks; power efficiency AB We develop an initial dynamic power-concious routing scheme (MPR) that incorporates physical layer and link layer statistics to conserve power, while compensating for the channel conditions and interference environment at the intended receiver. The aim of MPR is to route a packet on a path that will require the least amount of total power expended and for each node to transmit with just enough power to ensure reliable communication. We evaluate the performance of MPR and present our preliminary results. C1 NIST, Gaithersburg, MD 20899 USA. RP Subbarao, MW (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 7 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 1999 VL 104 IS 6 BP 587 EP 593 DI 10.6028/jres.104.037 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 293YK UT WOS:000085882700005 ER PT J AU Zarr, RR Lagergren, ES AF Zarr, RR Lagergren, ES TI Interlaboratory "pilot run" study of small heat-flow-meter apparatus for ASTM C 518 SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE bias; glass fiber; guarded hot plate; heat flow meter; interlaboratory; precision; repeatability; reproducibility; thermal conductivity; thermal insulation AB Thermal conductivity measurements of a high-density glass-fiber thermal insulation material near 24 degrees C are presented for the determination of the precision and bias of ASTM Test Method C 518. The measurements have been conducted by 13 laboratories using small (305 by 305-mm) heat-flow-meter apparatus on three specimens of high-density grass-fiber thermal insulation material that were circulated among the laboratories. Test results are analyzed using ASTM Practice E 691 and subsequently compared to measurements of the same specimens conducted in a guarded-hot-plate apparatus using ASTM Test Method C 177. The 95% repeatability and reproducibility indexes for precision have been determined to be no worse than 1.1 and 4.0%, respectively. A method for estimating bias is presented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Nabisco, E Hanover, NJ 07936 USA. RP Zarr, RR (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 4 TC 0 Z9 0 U1 1 U2 3 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD NOV PY 1999 VL 27 IS 6 BP 357 EP 367 PG 11 WC Materials Science, Characterization & Testing SC Materials Science GA 287YT UT WOS:000085535600001 ER PT J AU Montemayor, RG Rogerson, JE Colbert, JC Schiller, SB AF Montemayor, RG Rogerson, JE Colbert, JC Schiller, SB TI Reference verification fluids for flash point determination SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE flash point; verification fluids; n-decane; n-undecane; n-tetradecane; n-hexadecane; p-xylene AB The flash point of a liquid material is used to classify whether the material is flammable or combustible. 1,4-dimethylbenzene (p-xylene) has been used historically to verify the proper operation of different flash point test equipment. Because of the toxicity and low flash point value of 1,4-dimethylbenzene, an interlaboratory study was conducted to determine alternate flash point reference standards. This study reports the flash points of n-decane, n-undecane, n-tetradecane, and n-hexadecane using various flash point test methods. The flash points of these materials were found to be test-method dependent because of the inherent differences in the various flash point test methods. The reported reference flash point values of these materials are now used to verify the proper operation of flash point test equipment in place of 1,4-dimethylbenzene. C1 Imperial Oil Ltd, Prod & Chem Div, Sarnia, ON N7T 7M5, Canada. Cedar Lane Farm, Maineville, OH 45039 USA. Natl Inst Stand & Technol, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Montemayor, RG (reprint author), Imperial Oil Ltd, Prod & Chem Div, POB 3004, Sarnia, ON N7T 7M5, Canada. NR 6 TC 2 Z9 2 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD NOV PY 1999 VL 27 IS 6 BP 423 EP 427 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 287YT UT WOS:000085535600009 ER PT J AU Zimmermann, A Fuller, ER Rodel, J AF Zimmermann, A Fuller, ER Rodel, J TI Residual stress distributions in ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID THERMAL-EXPANSION ANISOTROPY; AL2O3; MODEL AB Residual stress distributions in ceramics can be calculated for a coordinate system fixed by the specimen geometry as well as for the crystal system. Computations were performed using alumina as a model system with the residual stresses caused by thermal expansion anisotropy. Mean values and standard deviations of the stress distributions are calculated for a plane stress as well as a plane strain scenario in a laboratory coordinate system and compared to distributions of stresses occuring along the a-axis and c-axis of alumina. In addition, stress fluctuations in the whole assembly of grains are compared with stress fluctuations within and between individual grains. C1 Darmstadt Univ Technol, Ceram Grp, D-64287 Darmstadt, Germany. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Zimmermann, A (reprint author), Darmstadt Univ Technol, Ceram Grp, D-64287 Darmstadt, Germany. NR 23 TC 43 Z9 43 U1 0 U2 9 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 NOV PY 1999 VL 82 IS 11 BP 3155 EP 3160 PG 6 WC Materials Science, Ceramics SC Materials Science GA 291XC UT WOS:000085763800033 ER PT J AU Blendell, JE Vaudin, MD Fuller, ER AF Blendell, JE Vaudin, MD Fuller, ER TI Determination of texture from individual grain orientation measurements SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MARCH AB We present a technique for determining the texture of a polycrystalline material based on the measurement of the orientation of a number of individual grains. We assumed that the sample has fiber (i.e,, axisymmetric) texture and that the texture can be characterized by a function (the March-Dollase function) with a single parameter. We simulated a large number, N, of orientation data sets, using the March-Dollase function for a total of five different texture parameters, r(init). Using the maximum-likelihood method, we solved for the texture parameter, r', that best fits each simulated data set in order to determine the distribution of r' and evaluate the precision and accuracy with which r' can be determined, The 90% confidence limits of the ratio r'/r(init) vary as N-1/2 but were independent of r(init). Using the texture of slightly textured Al2O3 as determined by X-ray diffraction, we calculated the 90% confidence limits for measurements of 131 grains. The orientations of 131 grains in textured Al2O3 were measured by electron backscatter diffraction, and the texture determined from those measurements lay within these 90% confidence limits. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Blendell, JE (reprint author), NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 9 TC 18 Z9 18 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1999 VL 82 IS 11 BP 3217 EP 3220 PG 4 WC Materials Science, Ceramics SC Materials Science GA 291XC UT WOS:000085763800042 ER PT J AU Vilker, VL Reipa, V Mayhew, M Holden, MJ AF Vilker, VL Reipa, V Mayhew, M Holden, MJ TI Challenges in capturing oxygenase activity in vitro SO JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY LA English DT Article DE biocatalysis; bioelectrochemistry; cytochrome P450; desaturase; electro-enzymology; 5-exo-hydroxy camphor; omega-hydroxylation of fatty acids; monooxygenase; NAD(P)H regeneration; styrene oxide ID DIRECT ELECTRON-TRANSFER; MODIFIED GOLD ELECTRODE; CYTOCHROME-C; ENZYMATIC REDUCTION; SILVER ELECTRODE; DIRECT ELECTROCHEMISTRY; INSITU REGENERATION; ORGANIC-SYNTHESIS; MEMBRANE REACTOR; PUTIDAREDOXIN AB Biocatalysis using oxygenase or desaturase enzymes has the potential to add value to native fats and oils by adding oxygen, hydroxyl groups, or double bonds to create regio- and/or stereospecific products. These enzymes are a subset of the large class of oxidoreductase enzymes (from EC subgroups 1.13 and 1.14) involved with biological oxidation and reduction. In vitro biocatalytic processing using these enzymes is hampered by the high cost of the stoichiometric cofactors. This article reviews recent progress in developing in vitro redox enzyme biocatalysis for commercial-scale syntheses. Coenzyme recycling and electrochemical redox cycling as methods for cofactor regeneration are described and commercial applications indicated. Direct charge transfer without use of mediators is described as the cleanest way of introducing the reducing power into the catalytic cycle. Our electrochemically driven cytochrome P450(cam) bioreactor is discussed as an example of direct charge transfer to a redox protein. Site-directed mutagenesis in the active site of the P450(cam) monooxygenase greatly improved performance for the conversion of the nonnative substrate, styrene to styrene oxide. This epoxidation reaction was also shown to give a single product (styrene oxide) in the bioelectrochemical reactor when the diatomic oxygen co-substrate was managed properly. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Vilker, VL (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 44 TC 26 Z9 27 U1 1 U2 11 PU AMER OIL CHEMISTS SOC A O C S PRESS PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 USA SN 0003-021X J9 J AM OIL CHEM SOC JI J. Am. Oil Chem. Soc. PD NOV PY 1999 VL 76 IS 11 BP 1283 EP 1289 DI 10.1007/s11746-999-0140-1 PG 7 WC Chemistry, Applied; Food Science & Technology SC Chemistry; Food Science & Technology GA 256RC UT WOS:000083738400005 ER PT J AU Gage, KS Williams, CR Ecklund, WL Johnston, PE AF Gage, KS Williams, CR Ecklund, WL Johnston, PE TI Use of two profilers during MCTEX for unambiguous identification of Bragg scattering and Rayleigh scattering SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID RAINDROP SIZE DISTRIBUTIONS; AIR RADAR ECHOES; CLEAR-AIR; WIND PROFILER; DOPPLER RADAR; CLOUD SYSTEMS; LAYERS; PRECIPITATION; STRATOSPHERE; FLUCTUATIONS AB A 2835-MHz (10.6-cm wavelength) profiler and a 920-MHz (32.6-cm wavelength) profiler were collocated by the NOAA Aeronomy Laboratory at Garden Point, Australia, in the Tiwi Islands during the Maritime Continent Thunderstorm Experiment (MCTEX) field campaign in November and December 1995. The two profilers were directed vertically and observed vertical velocities in the clear atmosphere and hydrometeor fall velocities in deep precipitating cloud systems. In the absence of Rayleigh scatterers, the profilers obtain backscattering,a from the refractive index irregularities created from atmospheric turbulence acting upon refractive index gradients. This kind of scattering is commonly referred to as Bragg scattering and is only weakly dependent on the radar wavelength provided the radar half-wavelength lies within the inertial subrange of homogeneous, isotropic turbulence. In the presence of hydrometeors the profilers observe Rayleigh backscattering from hydrometeors much as weather radars do and this backscatter is very dependent upon radar wavelength, strongly favoring the shorter wavelength profiler resulting in a 20-dB enhancement, of the ability of the 2835-MHz profiler to observe hydrometeors. This paper presents observations of equivalent reflectivity, Doppler velocity, and spectral width made by the collocated profilers during MCTEX. Differential reflectivity is used to diagnose the type of echo observed by the profilers in the spectral moment data. When precipitation or other particulate backscatter is dominant, the equivalent reflectivities are essentially the same for both profilers. When Bragg scattering is the dominant process, equivalent reflectivity observed by the 1-GHz profiler exceeds the equivalent reflectivity observed by the 3-GHz profiler by approximately 18 dBZe. However, when the 3-GHz profiler half-wavelength is smaller than the inner scale of turbulence, the equivalent reflectivity difference exceeds 18 dBZe, and when both Rayleigh scattering and Bragg scattering are observed simultaneously, the equivalent reflectivity difference is less than 18 dBZe. The results obtained confirm the capability of two collocated profilers to unambiguously identify the type of echo being observed and hence enable the segregation of "clear air" and precipitation echoes for studies of atmospheric dynamics and precipitating cloud systems. C1 NOAA, Environm Res Lab, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Gage, KS (reprint author), NOAA, Environm Res Lab, Aeron Lab, R-E-AL3,325 Broadway, Boulder, CO 80303 USA. 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 44 TC 34 Z9 34 U1 0 U2 1 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 1999 VL 56 IS 21 BP 3679 EP 3691 DI 10.1175/1520-0469(1999)056<3679:UOTPDM>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 247AM UT WOS:000083198500005 ER PT J AU Byun, DW AF Byun, DW TI Dynamically consistent formulations in meteorological and air quality models for multiscale atmospheric studies. Part I: Governing equations in a generalized coordinate system SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MESOSCALE MODEL; NONHYDROSTATIC VERSION; ETA-MODEL; TRANSFORMATION; SIMULATION AB In recent years, the popularity of the fully compressible nonhydrostatic atmospheric models has increased due to the need for simulating multiscale dynamics from convective to synoptic weather phenomena. These recent advances in meteorological modeling techniques present a new set of implementation difficulties and challenges for air quality models and others that are dependent on prognostic meteorological models because some of the scalar quantities are not conserved adequately due to the nature of numerical formulations in these models. To provide a foundation for conservative discrete formulations in atmospheric models, this paper proposes a set of governing equations for a fully compressible atmosphere in a generalized coordinate system. The idealized set of governing equations for atmospheric studies includes conservative equations for the thermodynamic variables and trace species as well as equations for wind components. For the thermodynamic parameters, a continuity equation for air density and a conservation equation for entropy are preferred to the prognostic equations for pressure and temperature. The proposed set of governing equations allows for a unified description of atmospheric dynamics, thermodynamics, and air quality problems. Alternative prognostic and diagnostic formulations of the governing equations and their characteristics are studied for different coordinate systems. The companion paper addresses the mass conservation issues in multiscale air quality applications. C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC USA. RP Byun, DW (reprint author), US EPA, Atmospher Sci Modeling Div, MD-80 Bldg,4201,Rm 324,79 TW Alexander Dr, Res Triangle Pk, NC 27709 USA. NR 34 TC 32 Z9 33 U1 0 U2 3 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 1999 VL 56 IS 21 BP 3789 EP 3807 DI 10.1175/1520-0469(1999)056<3789:DCFIMA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 247AM UT WOS:000083198500013 ER PT J AU Byun, DW AF Byun, DW TI Dynamically consistent formulations in meteorological and air quality models for multiscale atmospheric studies. Part II: Mass conservation issues SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WIND FIELDS; OZONE CONCENTRATIONS; GLOBAL ANALYSES; SYSTEM; PERFORMANCE; TRANSPORT; DESIGN; URBAN AB Eulerian air quality models that require gridded meteorological inputs have to adapt to recent advances in meteorological models for fully compressible atmosphere. When the input meteorological data are recast with a robust fully compressible governing set of equations, chemistry-transport models can follow the dynamic and thermodynamic descriptions of the meteorological data closely. For evaluating mass consistency in meteorological data, one may rake advantage of the characteristics of the governing set of equations applicable for a specific vertical coordinate system. This paper discusses how the data from meteorological models should be used in air quality simulations. It proposes a general methodology to conserve mass of trace species in air quality models by maintaining consistency in the wind and air density fields. Limitations of several simplifying assumptions on atmospheric dynamics are also discussed. In summary, it attempts to bridge the information gap between dynamic meteorologists and air quality modelers by highlighting the implication of using different meteorological coordinates and dynamic assumptions for air quality simulations. C1 US EPA, NERL, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27709 USA. RP Byun, DW (reprint author), US EPA, NERL, Atmospher Sci Modeling Div, MD-80 Bldg 4201,Rm 324,79 TW Alexander Dr, Res Triangle Pk, NC 27709 USA. NR 45 TC 50 Z9 51 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV 1 PY 1999 VL 56 IS 21 BP 3808 EP 3820 DI 10.1175/1520-0469(1999)056<3808:DCFIMA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 247AM UT WOS:000083198500014 ER PT J AU Wiberg, KB Marquez, M Gonzalez, C AF Wiberg, KB Marquez, M Gonzalez, C TI Rearrangement of perfluorocyclobutyne SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID CYCLOBUTYNE AB The energies of cyclobutyne, perfluorocyclobutyne and related compounds have been calculated at levels from MP2/ 6-31G* through QCISD(T)/6-311 + G*, and also at B3LYP and B3PW91/6-311 + G*. The relative energies found with the larger basis sets are quite consistent. Cyclobutyne is calculated to be a transition slate at most levels of theory, leading to cyclopropylidenecarbene. However, the latter does not have C-2v symmetry, but rather undergoes a tilt of the carbene carbon toward a ring carbon leading to a distorted C-s structure. Perfluorocyclobutyne is calculated to have a significant activation energy for rearrangement at the MP2 level, but higher levels of theory suggest that it will rearrange spontaneously to perfluorocyclopropylidenecarbene, again with a distorted structure. The calculated heats of hydrogenation of the cyclobutynes are about 70 kcal mol(-1) greater than for acetylene. The energy of a process by which perfluorocyclobutyne or perfluorocyclopropylidinecarbene might be formed is also calculated. C1 Yale Univ, Dept Chem, New Haven, CT 06520 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wiberg, KB (reprint author), Yale Univ, Dept Chem, 225 Prospect St, New Haven, CT 06520 USA. RI Wiberg, Kenneth/A-2556-2012 NR 18 TC 1 Z9 1 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD NOV PY 1999 IS 11 BP 2333 EP 2337 DI 10.1039/a904538d PG 5 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA 278MB UT WOS:000084992600013 ER PT J AU Garrison, TWS Beck, M Christensen, DH AF Garrison, TWS Beck, M Christensen, DH TI Noise behavior of pulsed vertical-cavity surface-emitting lasers SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID RELATIVE INTENSITY NOISE; POLARIZATION INSTABILITY; MICROCAVITY LASER; PERFORMANCE; VCSELS; LIGHT AB We determine the pulse energy fluctuations of vertical-cavity surface-emitting lasers by measuring the number of photoelectrons produced when a laser pulse is incident upon a photodetector. We obtain probability distributions for the number of photoelectrons produced by the total pulse energy, as welI as distributions produced by the energy in each of the two orthogonal laser polarizations. We find that the noise of the laser increases when each new laser mode comes above threshold and that the individual polarization outputs are noisier than the total output, which indicates negative correlations between the energies in the two polarizations. We also find that, while the statistics of the total output are Gaussian, this is not always true of the individual polarizations. (C) 1999 Optical Society of America [S0740-3224(99)02209-2]. C1 Whitman Coll, Dept Phys, Walla Walla, WA 99362 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Garrison, TWS (reprint author), Whitman Coll, Dept Phys, Walla Walla, WA 99362 USA. OI Beck, Mark/0000-0002-2023-5128 NR 23 TC 4 Z9 4 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD NOV PY 1999 VL 16 IS 11 BP 2124 EP 2130 DI 10.1364/JOSAB.16.002124 PG 7 WC Optics SC Optics GA 252TV UT WOS:000083519100035 ER PT J AU Goodman, RS Materer, N Leone, SR AF Goodman, RS Materer, N Leone, SR TI Ion-enhanced etching of Si(100) with molecular chlorine: Reaction mechanisms and product yields SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID CONTAINING PLASMAS; SURFACE-CHEMISTRY; CL2 ENVIRONMENT; SI SURFACES; SILICON; ENERGY; MASS; CL-2; AR+; THERMOCHEMISTRY AB Laser single-photon ionization time-of-flight mass spectrometry is used to measure silicon etch products that evolve during argon ion-enhanced etching of room temperature Si(100) with molecular chlorine over an ion energy range of 275-975 eV. The etch products are examined as a function of ion energy, ion flux, and molecular chlorine flux. The neutral Si atom, SiCl, and SiCl2 are the only product species observed with the 118 nm ionization and are detected directly without fragmentation. The Si and SiCl species are the main products, with the latter having much greater yield. The yield of each product increases with increasing ion energy. The SiCl/Si yield ratio increases with decreasing ion kinetic energy, indicating an increase in the chlorine surface coverage at lower ion energies. A simple kinetic model, including chlorine adsorption and sputtering of the resulting silicon chloride surface moieties, is proposed to describe the formation of Si and SiCl etch products. A model describing the chlorine pressure dependence of Si atom sputtering is developed in which the sputtering of Si atoms occurs from two different precursor states, one from an unchlorinated site and another from a partially chlorinated site. Using this kinetic model, the sputtering yield for SiCl per Ar+ is estimated from the molecular chlorine flux dependence of the SiCl signals and ranges from 3.2+/-0.8 to 4.9+/-0.9. (C) 1999 American Vacuum Society. [S0734-2101(99)01406-2]. 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 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM srl@jila.colorado.edu NR 36 TC 10 Z9 10 U1 0 U2 1 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD NOV-DEC PY 1999 VL 17 IS 6 BP 3340 EP 3350 DI 10.1116/1.582063 PG 11 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 257NP UT WOS:000083788400027 ER PT J AU Sobolewski, MA Steffens, KL AF Sobolewski, MA Steffens, KL TI Electrical control of the spatial uniformity of reactive species in plasmas SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID LASER-INDUCED FLUORESCENCE; CONFERENCE REFERENCE CELL; RADIOFREQUENCY DISCHARGES; IMPEDANCE ANALYSIS; RF DISCHARGES; ARGON; POLYSILICON; DEPOSITION; DENSITY; SYSTEM AB We report a new method for controlling the spatial distribution of reactive chemical species in a parallel-plate plasma reactor, by means of a variable-impedance load placed between the unpowered electrode and ground. The technique was demonstrated in 89% CF4/11% O-2 and 51% C2F6/49% O-2 chamber-cleaning plasmas at 13.3-133 Pa (0.1-1.0 Torr) in a Gaseous Electronics Conference Reference Cell. The rf current and voltage at both electrodes were measured, and plasma spatial characteristics were observed using two-dimensional (2D) planar laser-induced fluorescence of the CF2 radical and 2D broadband optical emission measurements. By adjusting the load impedance to cancel the impedance of stray capacitances in parallel with the load, or the sheath capacitance in series with the load, the rf current at the load electrode could be made higher or lower than the current received when the electrode is grounded. When the rf current at the load electrode was minimized, regions of intense optical emission and high CF2 density were shifted radially outward from the center of the reactor. When the rf current at the load electrode was maximized, regions of intense optical emission and high CF2 density shifted radially inward, and the distribution of CF2 across the electrode surfaces became more uniform. These results suggest that variable loads could be used to direct reactive species in chamber-cleaning plasmas to the surfaces most in need of cleaning, or to increase the radial uniformity of reactive species in etching plasmas. [S0734-2101(99)00706-X]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sobolewski, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 28 TC 23 Z9 24 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1999 VL 17 IS 6 BP 3281 EP 3292 DI 10.1116/1.582055 PG 12 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 257NP UT WOS:000083788400019 ER PT J AU Swarzenski, PW McKee, BA Skei, JM Todd, JF AF Swarzenski, PW McKee, BA Skei, JM Todd, JF TI Uranium biogeochemistry across the redox transition zone of a permanently stratified fjord: Framvaren, Norway SO MARINE CHEMISTRY LA English DT Review DE Framvaren Fjord; uranium biogeochemistry; U oxidation states; microbial mobilization; oxidation-reduction ID COASTAL MARINE-SEDIMENTS; BLACK-SEA; CHEMICAL SPECIATION; MICROBIAL REDUCTION; AMAZON SHELF; PORE WATERS; GEOCHEMISTRY; PARTICULATE; MANGANESE; BEHAVIOR AB During August 1995, the vertical concentration profile of dissolved and particulate uranium exhibited strong non-conservative characteristics in the upper 30 m of Framvaren Fjord. There was a pronounced peak in both particulate (> 0.2 mu m; 1.09 nM) and dissolved (< 0.2 mu m: 17.06 nM) uranium in the finely stratified waters at the O-2/H2S interface which is positioned well within the euphotic zone at about 20-21 m. Such concentration maxima at the redox boundary are also observed for dissolved organic carbon (DOC), Sr and Pa. Dissolved U levels seen in the water column from 18 m down to 30 m exceeded the high salinity (salinity = 35)U concentrations (13.63 +/- 0.84 nM; Chen, J.H., Edwards, R.L., Wasserburg, G.L., 1986, U-238, U-234 and Th-232 in seawater. Earth Planet Sci. Lett. 80, 241-251.) observed uniformly in the open ocean. A prolific population of S microbes (e.g., Chromatium, Chlorobium sp.) flourishes at the O-2/H2S interface. The source of elevated U at the redox boundary must be due to microbial uptake and subsequent release processes rather than dilution from oceanic uranium. Uranium oxidation state determinations in waters from 1, 22 and 30 m depth reveal that reduced U(IV) is not present in significant abundance, and that the chemical and/or biological reduction of hexavalent uranium is largely inhibited. Our results suggest that U and other trace constituents such as DOG, Sr, Ba, Fe(II), Mn(II) are greatly modified by direct and indirect microbial transformation reactions which are most concentrated across the redox transition zone in Framvaren Fjord. (C) 1999 Elsevier Science B.V. All rights reserved. C1 US Geol Survey, Ctr Coastal Geol, St Petersburg, FL 33701 USA. Tulane Univ, Inst Earth & Ecosyst Sci, Dept Geol, New Orleans, LA 70118 USA. Norwegian Inst Water Res, N-0411 Oslo, Norway. NOAA, Off Global Programs, Silver Spring, MD 20910 USA. RP Swarzenski, PW (reprint author), US Geol Survey, Ctr Coastal Geol, 600 4th St S, St Petersburg, FL 33701 USA. EM pswarzen@usgs.gov NR 108 TC 24 Z9 25 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 EI 1872-7581 J9 MAR CHEM JI Mar. Chem. PD NOV PY 1999 VL 67 IS 3-4 BP 181 EP 198 DI 10.1016/S0304-4203(99)00058-4 PG 18 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 259JY UT WOS:000083891800004 ER PT J AU Swarzenski, PW McKee, BA Sorensen, K Todd, JF AF Swarzenski, PW McKee, BA Sorensen, K Todd, JF TI Pb-210 and Po-210, manganese and iron cycling across the O-2/H2S interface of a permanently anoxic fjord: Framvaren, Norway SO MARINE CHEMISTRY LA English DT Article DE Po-210/Pb-210 biogeochemistry; microbial mobilization; phase partitioning; oxidation/reduction; Framvaren Fjord ID SEA-SURFACE MICROLAYER; PARTICULATE MATTER; OLIGOTROPHIC LAKE; TRANSITION ZONE; RESIDENCE TIMES; BLACK-SEA; MARINE; WATERS; PACIFIC; DISTRIBUTIONS AB Vertical profiles of dissolved and particulate Po-210 and were measured across the redox transition zone at Station F1 in Framvaren Fjord, Norway. In this fjord, a sharp decrease in pH above the O-2/H2S interface facilitates the aerobic dissolution of MnO2. In contrast, Fe(II) concentrations begin to increase only at the O-2/H2S interface depth. Activity profiles reveal that dissolved Po-210 and Pb-210 are sequestered efficiently by particulates in surface waters. As polonium-210 and lead-210 activities descend down into the aerobic manganese reduction (AMR) zone, they are remobilized during the reductive dissolution of the carrier phase oxyhydroxides. Both Po-210 and Pb-210 are highly enriched at the O-2/H2S interface where an active community of microbes, such as anoxygenic phototrophs (e.g., Chromatium, Chlorobium sp.), thrives. The coincident peaks in Po-210, Pb-210 and microbial biomass suggest a strong biological influence on the behavior of these radionuclides. There is a strong covariance between the vertical distribution of Mn and Pb, indicating that their redox cycling is closely coupled and is Likely microbially mediated. (C) 1999 Elsevier Science B.V. All rights reserved. C1 US Geol Survey, Ctr Coastal Geol, St Petersburg, FL 33701 USA. Tulane Univ, Inst Earth & Ecosyst Sci, Dept Geol, New Orleans, LA 70118 USA. Norwegian Inst Water Res, N-0411 Oslo, Norway. NOAA, Off Global Programs, Silver Spring, MD 20910 USA. RP Swarzenski, PW (reprint author), US Geol Survey, Ctr Coastal Geol, 600 4th St S, St Petersburg, FL 33701 USA. RI Mason, Robert/A-6829-2011 NR 85 TC 25 Z9 26 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD NOV PY 1999 VL 67 IS 3-4 BP 199 EP 217 DI 10.1016/S0304-4203(99)00059-6 PG 19 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 259JY UT WOS:000083891800005 ER PT J AU Hamstad, MA McColskey, JD AF Hamstad, MA McColskey, JD TI Detectability of slow crack growth in bridge steels by acoustic emission SO MATERIALS EVALUATION LA English DT Article DE acoustic emission; fatigue cracks; material characterization; bridge steels ID SENSORS AB The detectability of slow growth of cracks in bridge steels has been studied by use of acoustic emission testing technology. Fatigue crack growth rates of nominally 2 x 10(-4) mm/cycle (4 x 10(-6) in./cycle) and 1 x 10(-3) mm/cycle (4 x 10(-5) in./cycle) were monitored with an eight channel, 12-bit, waveform-based, acoustic emission measurement system. Eight acoustic emission sensors were arranged on plates nominally 25 mm (I in.) thick (A588, A572, A36, A7, A514 steels and 2024 T351, aluminum alloy). Four of the sensors were typical resonant, commercial acoustic emission sensors, and four sensors were wideband, high sensitivity sensors developed at NIST. The resonant sensors were bandpassed from 100 to 300 kHz and the wideband sensors from 50 kHz to 1.5 MHz. Each recorded acoustic emission event produced eight simultaneous waveforms. A representative series of event waveforms from each test was analyzed. Crack events were sorted from extraneous acoustic emission events visually, using the relative arrival sequence of sets of whole waveforms. The extraneous events normally originated in the specimen grip region. Typically, at the lower crack growth rate, several thousand cycles were required to obtain one valid crack acoustic emission signal. The results from A514 steel and 2024 aluminum were exceptions. The A514 steel had 20 crack acoustic emission events over eight consecutive cycles and none over the other 12 461 cycles examined. The 2024 aluminum had a crack event approximately every 12 cycles. At the higher crack growth rate, approximately one or two cycles were required for a valid event from A514 steel and 2024 aluminum. The other steels required 18 to 130 cycles fora valid event. The behavior of crack-generated acoustic emission will be discussed in terms of rise times of acoustic emission sources as related to material microstructure, In addition, indications of classes of crack events as observed with the wideband sensors will be discussed. Supporting experiments and results from plate specimens with large lateral dimensions (533 x 457 mm [21 x 18 in.]) are presented. These studies on steel 6.4 mm (0.25 in.) thick demonstrate the significance of attenuation of the signals from a sensor located at the crack tip to a sensor approximately 102 mm (4 in.) away. These supporting experiments also demonstrate the changes in signal amplitudes due to acoustic emission source radiation pattern effects as well as signal reflections. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Denver, Denver, CO 80208 USA. RP Hamstad, MA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 10 Z9 10 U1 0 U2 5 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD NOV PY 1999 VL 57 IS 11 BP 1165 EP 1174 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA 254GK UT WOS:000083603400009 ER PT J AU Elipe, A Deprit, A AF Elipe, A Deprit, A TI Oscillators in resonance SO MECHANICS RESEARCH COMMUNICATIONS LA English DT Article C1 Univ Zaragoza, Grp Mecan Espacial, E-50009 Zaragoza, Spain. Natl Inst Stand & Technol, Washington, DC USA. RP Elipe, A (reprint author), Univ Zaragoza, Grp Mecan Espacial, E-50009 Zaragoza, Spain. RI Elipe, Antonio/B-8341-2008 OI Elipe, Antonio/0000-0001-5208-4494 NR 9 TC 32 Z9 32 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0093-6413 J9 MECH RES COMMUN JI Mech. Res. Commun. PD NOV-DEC PY 1999 VL 26 IS 6 BP 635 EP 640 DI 10.1016/S0093-6413(99)00072-5 PG 6 WC Mechanics SC Mechanics GA 267BJ UT WOS:000084334500001 ER PT J AU Gavens, AJ van Heerden, D Foecke, T Weihs, TP AF Gavens, AJ van Heerden, D Foecke, T Weihs, TP TI Fabrication and evaluation of Nb/Nb5Si3 microlaminate foils SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID SILICIDE-NIOBIUM COMPOSITES; MECHANICAL-PROPERTIES; TOUGHNESS; STRENGTH; BEHAVIOR; FRACTURE; ALLOYS; MOSI2 AB Alloys of Nb and Nb5Si3, and in particular Nb/Nb5Si3 microlaminates, have potential as high-temperature materials. In this study, microlaminates of Nb and amorphous Nb-37.5 at. pet Si are magnetron sputter deposited from elemental Nb and polycrystalline Nb5Si3 targets. The microlaminates are heat treated at high temperatures to produce crystalline layers of Nb and Nb5Si3 that are flat, distinct, and stable for at least 3 hours at 1200 degrees C. The layers consist of textured Nb grains and equiaxed submicron Nb5Si3 grains. Initial room-temperature tensile tests indicate that the microlaminates have strengths similar to cast and extruded alloys of Nb and Nb5Si3 The fracture mode of the Nh layers is dependent on the Nb layer thickness, with thin layers failing in a ductile manner and thick layers failing by cleavage. The Nb layers bridge periodic cracks in the Nb5Si3 layers, and using a shear lag analysis, the tensile strength of Nb5Si3 is estimated. The results indicate that microstructurally stable and mechanically robust microlaminates of Nb and Nb5Si3 can be fabricated by sputter deposition with a high-temperature heat treatment. The processing, microstructure, and mechanical properties of these microlaminates are discussed. C1 Krolls Atom Power Lab, Schenectady, NY 12309 USA. Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Krolls Atom Power Lab, Schenectady, NY 12309 USA. RI Weihs, Timothy/A-3313-2010 NR 28 TC 14 Z9 17 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD NOV PY 1999 VL 30 IS 11 BP 2959 EP 2965 DI 10.1007/s11661-999-0133-6 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 258CZ UT WOS:000083821700024 ER PT J AU Simon, CG Holloway, PW Gear, ARL AF Simon, CG Holloway, PW Gear, ARL TI Exchange of C-16-ceramide between phospholipid vesicles SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Virginia, Charlottesville, VA 22903 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA PUBL OFFICE, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD NOV PY 1999 VL 10 SU S MA 1933 BP 334A EP 334A PG 1 WC Cell Biology SC Cell Biology GA 255MW UT WOS:000083673501935 ER PT J AU Cailliet, GM Andrews, AH Wakefield, WW Moreno, G Rhodes, KL AF Cailliet, GM Andrews, AH Wakefield, WW Moreno, G Rhodes, KL TI Fish faunal and habitat analyses using trawls, camera sleds and submersibles in benthic deep-sea habitats off central California SO OCEANOLOGICA ACTA LA English DT Article; Proceedings Paper CT International Conference on Marine Benthic Habitats and their Living Resources - Monitoring, Management and Applications to Pacific Island Countries CY NOV 10-16, 1997 CL NOUMEA, NEW CALEDONIA SP South Pacific Appl Geosci Commiss, Intergovt Oceanog Commiss, Terr New Caledonia & Its Provinces, Inst Francais Rech Exploitat Mer, Inst Rech Deve, Natl Sci Fdn, Secretariat Pacific Comm, Netherlands Geosci Fdn, Swedish Int Dev Cooperat Agcy, European Union DE deep-sea; fishes; habitat; sampling; submersibles ID PHOTOGRAPHIC SURVEY; DEMERSAL FISHES; NORTH-ATLANTIC; SLOPE; MEGAFAUNA; ASSEMBLAGES; GROWTH; SYSTEM; DEPTHS; COAST AB Beam trawl, camera sled and submersible data from 2 000-3 300 m off central California produced similar fish faunal composition, but different density estimates. All species caught in trawls were observed in camera-sled and submersible observations. However, some rare species that were observed were not caught in trawls. The fish fauna was dominated by the families Macrouridae, Zoarcidae, Moridae, and Rajidae. Fishes both trawled and observed were the macrourids Coryphaenoides armatus, C. filifer and C. leptolepis; the zoarcids Bothrocara spp., Pachycara lepinium and Lycenchelys spp.; the morid Antimora microlepis; the rajid Bathyraja trachura, the ophidiid Spectrunculus grandis, and the liparidid Careproctus ovigerum. One unidentified liparidid (Paraliparis sp.) and two unidentified Lycenchelys spp. were trawled and may have been seen but also could not be identified to species from photographs. Observed only in photographs were the liparidids Paraliparis rosaceus and Careproctus melanurus, synodontid Bathysaurus mollis, and noto-canthid Notacanthus chemnitzii. These three techniques differed in their ability to provide specimens for accurate identification, counts, and later life history (feeding habit, age and growth, and reproduction) studies, and to provide information on dispersion, habitat utilization, behavior and interactions. Accurate density estimates were undoubtedly hampered by trawl and camera sled avoidance, escape, and uncertainties concerning the area trawled. Camera sleds produced higher (and perhaps better) estimates of density. Submersible observations from the DSV Alvin produced a similar species list but little additional, quantitative information. Both visual techniques allowed habitat characterization, but no strong faunal associations with habitat types were observed. (C) 1999 Ifremer / CNRS / IRD / Editions scientifiques et medicales Elsevier SAS. C1 Moss Landing Marine Labs, Moss Landing, CA 95039 USA. Oregon State Univ, Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, Newport, OR 97365 USA. Univ Hong Kong, Dept Ecol & Biodivers, Hong Kong, Peoples R China. RP Cailliet, GM (reprint author), Moss Landing Marine Labs, POB 450, Moss Landing, CA 95039 USA. EM caillet@mlml.calstate.edu RI Andrews, Allen/G-3686-2016 OI Andrews, Allen/0000-0002-9001-8305 NR 77 TC 34 Z9 34 U1 3 U2 9 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PD NOV-DEC PY 1999 VL 22 IS 6 BP 579 EP 592 DI 10.1016/S0399-1784(00)88949-5 PG 14 WC Oceanography SC Oceanography GA 274DQ UT WOS:000084748800004 ER PT J AU Greene, HG Yoklavich, MM Starr, RM O'Connell, VM Wakefield, WW Sullivan, DE McRea, JE Cailliet, GM AF Greene, HG Yoklavich, MM Starr, RM O'Connell, VM Wakefield, WW Sullivan, DE McRea, JE Cailliet, GM TI A classification scheme for deep seafloor habitats SO OCEANOLOGICA ACTA LA English DT Article; Proceedings Paper CT International Conference on Marine Benthic Habitats and their Living Resources - Monitoring, Management and Applications to Pacific Island Countries CY NOV 10-16, 1997 CL NOUMEA, NEW CALEDONIA SP South Pacific Appl Geosci Commiss, Intergovt Oceanog Commiss, Terr New Caledonia & Its Provinces, Inst Francais Rech Exploitat Mer, Inst Rech Deve, Natl Sci Fdn, Secretariat Pacific Comm, Netherlands Geosci Fdn, Swedish Int Dev Cooperat Agcy, European Union DE habitat; universal classification; benthic; fisheries management ID EASTERN AB A standard, universally useful classification scheme for deepwater habitats needs to be established so that descriptions of these habitats can be accurately and efficiently applied among scientific disciplines. In recent years many marine benthic habitats in deep water have been described using geophysical and biological data. These descriptions can vary from one investigator to another, which makes it difficult to compare habitats and associated biological assemblages among geographic regions. Using geophysical data collected with a variety of remote sensor systems and in situ biological and geologic observations, we have constructed a classification scheme that can be used in describing marine benthic habitats in deep water. (C) 1999 Ifremer / CNRS / IRD / Editions scientifiques et medicales Elsevier SAS. C1 Moss Landing Marine Labs, Moss Landing, CA 95039 USA. NOAA, Natl Marine Fisheries Serv, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. Univ Calif Sea Grant Extens Program, Moss Landing, CA 95039 USA. CFMD, Alaska Dept Fish & Game, Sitka, AK 99835 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Monterey Peninsula Coll, Monterey, CA 93940 USA. RP Greene, HG (reprint author), Moss Landing Marine Labs, POB 450, Moss Landing, CA 95039 USA. EM greene@mlml.calstate.edu NR 33 TC 145 Z9 148 U1 2 U2 28 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PD NOV-DEC PY 1999 VL 22 IS 6 BP 663 EP 678 DI 10.1016/S0399-1784(00)88957-4 PG 16 WC Oceanography SC Oceanography GA 274DQ UT WOS:000084748800012 ER PT J AU Logerwell, EA Ohman, MD AF Logerwell, EA Ohman, MD TI Egg-brooding, body size and predation risk in planktonic marine copepods SO OECOLOGIA LA English DT Article DE copepods; predation risk; egg-brooding; fish predation; body size ID STICKLEBACKS GASTEROSTEUS-ACULEATUS; SELECTIVE PREDATION; EUCHAETA-ELONGATA; CYCLOPOID COPEPOD; FISH PREDATION; PREY-SIZE; GROWTH; SUSCEPTIBILITY; HYPOTHESIS; MORTALITY AB We investigated the interacting effects of copepod body size and the presence or absence of egg masses on the risk of predation by a visual predator. We conducted selection experiments involving three-spined sticklebacks (Gasterosteus aculeatus) and copepods ranging in body mass from 0.5 to 740 mu g C: Oithona similis, Corycaeus anglicus, Pseudocalanus newmani, P. moultoni, Pseudodiaptomus marinus, and Paraeuchaeta elongata. We found that sticklebacks selected ovigerous females of the two smallest-bodied species of copepods (Oithona similis and Corycaeus anglicus). In contrast, the fish showed no significant selection for ovigerous females of the remaining, larger-bodied species. Unexpectedly, egg mass position (i.e., in a ventral, dorsal or lateral location on the urosome) appeared to influence predation risk more than did body size, resulting in higher predation risk for the cyclopoid and poecilostomatoid species than for the calanoid species we tested. Although the sticklebacks showed no statistically significant preference for ovigerous females of any of the four calanoid species, for each species the overall proportion of ovigerous females ingested was slightly greater than 0.50. Thus, whether body size influences the susceptibility of egg-brooding calanoid copepods to predation remains an open question. C1 Univ Calif San Diego, Scripps Inst Oceanog, Marine Life Res Grp, La Jolla, CA 92093 USA. RP Logerwell, EA (reprint author), SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. RI Ohman, Mark/C-8763-2009 NR 21 TC 8 Z9 8 U1 1 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD NOV PY 1999 VL 121 IS 3 BP 426 EP 431 DI 10.1007/s004420050948 PG 6 WC Ecology SC Environmental Sciences & Ecology GA 261RC UT WOS:000084021700018 PM 28308333 ER PT J AU Hsieh, ML Hsu, KY Paek, EG Wilson, CL AF Hsieh, ML Hsu, KY Paek, EG Wilson, CL TI Modulation transfer function of a liquid crystal spatial light modulator SO OPTICS COMMUNICATIONS LA English DT Article DE spatial light modulator; liquid crystal display; modulation transfer function ID CORRELATOR AB The modulation transfer function (MTF) of a pixelated liquid crystal spatial light modulator (LC-SLM) has been derived as a function of the fill factor. Based on the formula, we have investigated the dependence of the MTF on the orientations and spatial frequency of the input patterns. Furthermore, we have proposed and demonstrated a method for improving the MTF of a LC-SLM. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Natl Chiao Tung Univ, Inst Electroopt Engn, Hsin Chu, Taiwan. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hsu, KY (reprint author), Natl Chiao Tung Univ, Inst Electroopt Engn, Hsin Chu, Taiwan. RI Hsu, Ken/C-8645-2012 NR 4 TC 15 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 1 PY 1999 VL 170 IS 4-6 BP 221 EP 227 DI 10.1016/S0030-4018(99)00499-X PG 7 WC Optics SC Optics GA 252AM UT WOS:000083478600009 ER PT J AU Franz, S Donati, C Parisi, G Glotzer, SC AF Franz, S Donati, C Parisi, G Glotzer, SC TI On dynamical correlations in supercooled liquids SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 7th International Workshop on Disordered Systems CY MAR, 1999 CL MOLVENO, ITALY SP Univ Trento, Dipartimento Fis, Grp Nazl Struttura Mat ID GLASS-TRANSITION; SPIN-GLASS; CONNECTIONS AB We show how the growth of a dynamical correlation length and its associated susceptibility recently observed by the present authors and co-workers as T-c is approached can be understood in an appropriate theoretical framework. We discuss some predictions for these quantities in the region below T-c which have not yet been explored in numerical simulations. C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Rome La Sapienza, I-00185 Rome, Italy. RP Franz, S (reprint author), Abdus Salam Int Ctr Theoret Phys, Strada Costiera 11,POB 563, I-34100 Trieste, Italy. RI Donati, Claudio/J-5180-2012; franz, silvio/G-6963-2012; OI Donati, Claudio/0000-0001-8688-1651 NR 16 TC 79 Z9 79 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV-DEC PY 1999 VL 79 IS 11-12 BP 1827 EP 1831 DI 10.1080/13642819908223066 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 260LZ UT WOS:000083953300014 ER PT J AU Rafac, RJ Tanner, CE Livingston, AE Berry, HG AF Rafac, RJ Tanner, CE Livingston, AE Berry, HG TI Fast-beam laser lifetime measurements of the cesium 6p P-2(1/2,3/2) states SO PHYSICAL REVIEW A LA English DT Article ID PARITY NONCONSERVATION; RADIATIVE LIFETIMES; ATOMIC CESIUM; SPECTROSCOPY AB We provide a detailed description of our fast-beam laser lifetime measurements in atomic cesium. Selective excitation of the neutral Cs-133 6P P-2(1/2) and 6p P-2(3/2) states is accomplished with resonant diode laser light directed transversely to the atomic velocity. The in-flight decay of the excited-state fluorescence is observed with a position-correlated single photon-counting detector. The Doppler-shifted 6p P-2(3/2) resonance, when probed with longitudinally propagating laser radiation, provides a precise means for determination of the beam velocity, and converts the position scale to a time scale. Our lifetime results are 35.07+/-0.10 ns for the 6p P-2(1/2) state and 30.57+/-0.07 ns for the 6p P-2(3/2) state. These results represent a data set larger than in our previous work, and include beam divergence corrections which have been evaluated by two different methods. We present comparisons of our results with previous measurements and with relativistic many-body calculations of atomic transition matrix elements in this neutral alkali system. [S1050-2947(99)09711-5]. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. RP Rafac, RJ (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 37 TC 65 Z9 65 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1999 VL 60 IS 5 BP 3648 EP 3662 DI 10.1103/PhysRevA.60.3648 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 257ED UT WOS:000083768800046 ER PT J AU Stiles, MD McMichael, RD AF Stiles, MD McMichael, RD TI Temperature dependence of exchange bias in polycrystalline ferromagnet-antiferromagnet bilayers SO PHYSICAL REVIEW B LA English DT Article ID SPIN-VALVE STRUCTURES; THIN-FILMS; CO/COO BILAYERS; ANISOTROPY; RESONANCE; INTERFACES; COERCIVITY; PERMALLOY; REVERSAL; SYSTEM AB We describe a simple model for the dependence of tthe exchange bias and related effects that result from coupling a ferromagnetic thin film to a polycrystalline antiferromagnetic film. In this model, an important source of temperature dependence comes from thermal instabilities of the antiferromagnetic state in the antiferromagnetic grains, much as occurs in superparamagnetic grains. At low enough temperatures, the antiferromagnetic state in each grain is stable as the ferromagnetic magnetization is rotated and the model predicts the unidirectional anisotropy that gives rise to the observed exchange-bias loop shift. At higher temperatures, the antiferromagnetic state remains stable on short time scales, but on longer time scales, becomes unstable due to thermal excitations over energy barriers. For these temperatures, the model predicts the high field rotational hystersis found in rotational torque experiments and the isotropic field shift found in ferromagnetic resonance measurements. [S0163-1829(99)01842-1]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Stiles, MD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012; OI Stiles, Mark/0000-0001-8238-4156; McMichael, Robert/0000-0002-1372-664X NR 40 TC 145 Z9 146 U1 4 U2 24 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 1999 VL 60 IS 18 BP 12950 EP 12956 DI 10.1103/PhysRevB.60.12950 PG 7 WC Physics, Condensed Matter SC Physics GA 257CV UT WOS:000083765400061 ER PT J AU Burton, BP Cockayne, E AF Burton, BP Cockayne, E TI Why Pb(B,B ')O-3 perovskites disorder at lower temperatures than Ba(B,B ')O-3 perovskites SO PHYSICAL REVIEW B LA English DT Article ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; DIELECTRIC-PROPERTIES; MOLECULAR-DYNAMICS; SINGLE-CRYSTALS; BA(ZN1/3TA2/3)O-3; FERROELECTRICS; TRANSITION; BEHAVIOR; GROWTH AB Plane-wave pseudopotential calculations of total energies were performed for three ordered perovskite related supercells in each of the eight stoichiometries of A(B1/3B2/3')O-3; A = Pb, Ba, B = Zn, Mg and, B' = Nb, Ta; and the eight stoichiometries of A(B1/2B1/2')O-3; B = Sc,In. A striking difference between the Pb and Ba(B1/3B2/3')O-3 systems is that the differences in total energies for Pb systems span ranges that are roughly an order of magnitude smaller than those for the corresponding Ba systems. This indicates much lower energetic barriers to disordering in the Pb systems, consistent with experiments. We explain this trend as a consequence of enhanced Pb-O bonding to underbonded oxygens in B2+-O-B2+ environments. [S0163-1829(99)51642-1]. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Burton, BP (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 36 TC 69 Z9 71 U1 0 U2 8 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 1999 VL 60 IS 18 BP R12542 EP R12545 DI 10.1103/PhysRevB.60.R12542 PG 4 WC Physics, Condensed Matter SC Physics GA 257CV UT WOS:000083765400002 ER PT J AU Abdurashitov, JN Gavrin, VN Girin, SV Gorbachev, VV Ibragimova, TV Kalikhov, AV Khairnasov, NG Knodel, TV Mirnov, IN Shikhin, AA Veretenkin, EP Vermul, VM Yants, VE Zatsepin, GT Bowles, TJ Teasdale, WA Wark, DL Cherry, ML Nico, JS Cleveland, BT Davis, R Lande, K Wildenhain, PS Elliott, SR Wilkerson, JF AF Abdurashitov, JN Gavrin, VN Girin, SV Gorbachev, VV Ibragimova, TV Kalikhov, AV Khairnasov, NG Knodel, TV Mirnov, IN Shikhin, AA Veretenkin, EP Vermul, VM Yants, VE Zatsepin, GT Bowles, TJ Teasdale, WA Wark, DL Cherry, ML Nico, JS Cleveland, BT Davis, R Lande, K Wildenhain, PS Elliott, SR Wilkerson, JF CA SAGE Collaboration TI Measurement of the solar neutrino capture rate with gallium metal SO PHYSICAL REVIEW C LA English DT Article ID SAGE AB The solar neutrino capture rate measured by the Russian-American Gallium Experiment (SAGE) on metallic gallium during the period January 1990 through December 1997 is 67.2(-7.0-3.0)(+7.2+3.5) SNU, where the uncertainties are statistical and systematic, respectively. This represents only about half of the predicted standard solar model rate of 129 SNU. All the experimental procedures, including extraction of germanium from gallium, counting of Ge-71, and data analysis, are discussed in detail. [S0556-2813(99)03510-4]. C1 Russian Acad Sci, Inst Nucl Res, RU-117312 Moscow, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Penn, Philadelphia, PA 19104 USA. Univ Washington, Seattle, WA 98195 USA. RP Russian Acad Sci, Inst Nucl Res, RU-117312 Moscow, Russia. RI Abdurashitov, Dzhonrid/B-2206-2014; Yants, Viktor/C-1038-2014 OI Abdurashitov, Dzhonrid/0000-0002-1577-1364; NR 62 TC 472 Z9 473 U1 3 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 1999 VL 60 IS 5 AR 055801 DI 10.1103/PhysRevC.60.055801 PG 32 WC Physics, Nuclear SC Physics GA 257EB UT WOS:000083768600083 ER PT J AU Allegrini, P Douglas, JF Glotzer, SC AF Allegrini, P Douglas, JF Glotzer, SC TI Dynamic entropy as a measure of caging and persistent particle motion in supercooled liquids SO PHYSICAL REVIEW E LA English DT Article ID LENNARD-JONES MIXTURE; MODE-COUPLING THEORY; STOKES-EINSTEIN LAW; GLASS-TRANSITION; CHARACTERISTIC EXPONENTS; LYAPUNOV INSTABILITY; MOLECULAR-DYNAMICS; PHASE-TRANSITIONS; CHAOTIC DYNAMICS; ERGODIC-THEORY AB The length-scale dependence of the dynamic entropy is studied in a molecular dynamics simulation of a binary Lennard-Jones liquid above the mode-coupling critical temperature T-c. A number of methods exist for estimating the entropy of dynamical systems, and we utilize an approximation based on calculating the mean first-passage time (MFPT) for particle displacement because of its tractability and its accessibility in real and simulation measurements. The MFPT dynamic entropy S(epsilon) is defined as equal to the inverse of the average first-passage time for a particle to exit a sphere of radius epsilon. This measure of the degree of chaotic motion allows us to identify characteristic time and space scales and to quantify the increasingly correlated particle motion and intermittency occurring in supercooled liquids. In particular, we identify a "cage" size defining the scale at which the particles are transiently localized, and we observe persistent particle motion at intermediate length scales beyond the scale where caging occurs. Furthermore, we find that the dynamic entropy at the scale of one interparticle spacing extrapolates to zero as the mode-coupling temperature T-c is approached. [S1063-651X(99)00711-4]. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RP Douglas, JF (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Allegrini, Paolo/C-1876-2012 OI Allegrini, Paolo/0000-0002-5476-9005 NR 88 TC 49 Z9 49 U1 0 U2 5 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 1999 VL 60 IS 5 BP 5714 EP 5724 DI 10.1103/PhysRevE.60.5714 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 259AB UT WOS:000083870900010 PM 11970467 ER PT J AU Lee, BP Douglas, JF Glotzer, SC AF Lee, BP Douglas, JF Glotzer, SC TI Filler-induced composition waves in phase-separating polymer blends SO PHYSICAL REVIEW E LA English DT Article ID SPINODAL DECOMPOSITION; SHEAR-FLOW; DOMAIN GROWTH; BINARY-MIXTURES; FILMS; KINETICS; PATTERNS; SYSTEMS; FLUIDS; TEMPERATURE AB The influence of immobile tiller particles (spheres, fibers, platelets) on polymer-blend phase separation is investigated computationally using a generalization of the Cahn-Hilliard-Cook (CHC) model. Simulation shows that the selective affinity of one of the polymers for the filler surface leads to the development of concentration waves about the filler particles at sin early stage of phase separation in near critical composition blends. These "target" patterns are overtaken in late-stage phase separation by a growing "background" spinodal pattern characteristic of blends without filler particles. The Linearized CHC model is used to estimate the number of composition oscillations emanating from isolated filler particles. In far-off-critical composition blends, an "encapsulation layer" grows at the surface of the filler rather than a target pattern. The results of these simulations compare favorably with experiments on filled phase-separating ultrathin blend films in which the filler particles are immobilized on a solid substrate. [S1063-651X(99)12111-1]. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Bucknell Univ, Dept Phys, Lewisburg, PA 17837 USA. RP Douglas, JF (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 60 TC 65 Z9 65 U1 2 U2 14 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 1999 VL 60 IS 5 BP 5812 EP 5822 DI 10.1103/PhysRevE.60.5812 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 259AB UT WOS:000083870900022 PM 11970479 ER PT J AU Migdall, A AF Migdall, A TI Differences explained in correlated-photon metrology techniques SO PHYSICS TODAY LA English DT Letter C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Migdall, A (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1999 VL 52 IS 11 BP 15 EP + DI 10.1063/1.882651 PG 2 WC Physics, Multidisciplinary SC Physics GA 253EC UT WOS:000083542800004 ER PT J AU Phelps, AV Pitchford, LC Pedoussat, C Donko, Z AF Phelps, AV Pitchford, LC Pedoussat, C Donko, Z TI Use of secondary-electron yields determined from breakdown data in cathode-fall models for Ar SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID SIMULATION; DISCHARGES AB We test the utility of recently published secondary-electron yields per ion for the prediction of operating voltages for abnormal cathode-fall discharges in Ar for normalized current densities less than or equal to 20 mA cm(-2) Torr(-2). The effective secondary-electron yields per ion derived from spatially-uniform field breakdown and low-current discharge data give much too small discharge voltages at the higher current densities. in contrast, published secondary-electron yields per ion derived from ion-beam data at high ion energies and brakdown data at low ion energies give abnormal cathode-fall voltages that are within the present uncertainty of the models and of experimental data for Cu cathodes. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Toulouse 3, CNRS ESA 5002, CPAT, F-31062 Toulouse, France. Res Inst Solid State Phys & Opt, H-1525 Budapest, Hungary. RP Phelps, AV (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 11 TC 38 Z9 38 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD NOV PY 1999 VL 8 IS 4 BP B1 EP B2 DI 10.1088/0963-0252/8/4/401 PG 2 WC Physics, Fluids & Plasmas SC Physics GA 261KA UT WOS:000084007300001 ER PT J AU Migler, KB Hobbie, EK Qiao, F AF Migler, KB Hobbie, EK Qiao, F TI In line study of droplet deformation in polymer blends in channel flow SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID LIGHT-SCATTERING PHOTOMETER; MORPHOLOGY DEVELOPMENT; VISCOELASTIC FLUIDS; OPTICAL MICROSCOPE; BREAKUP; MICRORHEOLOGY; COALESCENCE; DISPERSION; DYNAMICS AB We present in situ measurements of a dilute polymer blend in channel flow using an optical flow cell placed at the exit of a twin screw extruder. At weak shear stress, we find mildly deformed ellipsoidal droplets whereas at moderate shear rates we find coexistence between large aspect ratio strings and ellipsoidal droplets. In the regime of low to moderate stress, depth resolved optical microscopy reveals that the deformation is a function of local shear stress. At large shear stress, the droplet breakup is suppressed; mildly deformed droplets at high capillary number are observed, in contrast to the Taylor model. Optical light scattering provides complementary morphological information that is averaged over the channel depth and confirms the optical microscopy. We discuss these results in terms of Taylor theory and normal forces. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Migler, KB (reprint author), NIST, Div Polymers, Bldg 224,Room B210, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 44 TC 25 Z9 25 U1 0 U2 4 PU SOC PLASTICS ENG INC PI BROOKFIELD PA 14 FAIRFIELD DR, BROOKFIELD, CT 06804-0403 USA SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD NOV PY 1999 VL 39 IS 11 BP 2282 EP 2291 DI 10.1002/pen.11616 PG 10 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 261JY UT WOS:000084007100015 ER PT J AU Muschinski, A Sullivan, PP Wuertz, DB Hill, RJ Cohn, SA Lenschow, DH Doviak, RJ AF Muschinski, A Sullivan, PP Wuertz, DB Hill, RJ Cohn, SA Lenschow, DH Doviak, RJ TI First synthesis of wind-profiler signals on the basis of large-eddy simulation data SO RADIO SCIENCE LA English DT Article ID VHF RADAR OBSERVATIONS; CONVECTIVE BOUNDARY-LAYER; STRUCTURE CONSTANT; DISSIPATION RATES; VERTICAL PROFILES; DOPPLER SPECTRA; MOMENTUM FLUX; TURBULENCE; MODEL; REFLECTION AB Radar wind profilers detect scatter from clear-air refractive-index irregularities. The Doppler shift calculated from the time series of the backscattered signal provides an estimate of the radial velocity of the air within the radar's resolution volume. It is known that there are quite a number of effects that can give rise to intrinsic biases in these radial-velocity estimates. It is extremely difficult to unambiguously identify these biases on the basis of observations since it is impossible to independently probe the three-dimensional, time-dependent fine structure of the relevant atmospheric variables (wind and refractive index) within the radar's resolution volume down to the relevant spatial and temporal scales associated with the scattering process itself. In this paper the large-eddy simulation (LES) technique is used to generate, with high spatial and temporal resolution (vertical resolution, 8 m; horizontal resolution, 16 m; time step, 0.8 s), data of atmospheric variables within a convective boundary layer. The LES data that are used in this study do not have the spatiotemporal resolution that would be needed for a deterministic, full solution of the scattering integral. However, a parameterized model of the scattering integral can be constructed on the basis of Kolmogorov-scaling arguments and a random-phase model. This model can be numerically solved on the basis of LES data. For the first time, LES-generated fields of virtual temperature, humidity, and three-dimensional wind are used to construct time series of the real and imaginary parts of wind-profiler signals. The simulated wind-profiler signals are processed to derive Doppler velocities, and the simulated Doppler Velocities are compared with the (simulated) meteorological "in situ truth" provided directly by the LES wind-velocity data set. Examples of simulation results and the potential of the LES-based, wind-profiler simulation technique as well as some limitations are discussed. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, Environm Technol Lab, Boulder, CO USA. Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Muschinski, A (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, 325 Broadway,R E ET4, Boulder, CO 80303 USA. OI LENSCHOW, DONALD/0000-0003-4353-0098 NR 55 TC 31 Z9 34 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD NOV-DEC PY 1999 VL 34 IS 6 BP 1437 EP 1459 DI 10.1029/1999RS900090 PG 23 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 258EC UT WOS:000083824300009 ER PT J AU Balzaretti, NM Gonzalez, EJ Piermarini, GJ Russell, TP AF Balzaretti, NM Gonzalez, EJ Piermarini, GJ Russell, TP TI Resistance heating of the gasket in a gem-anvil high pressure cell SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NANOSIZE PARTICLES; X-RAY; IRON; FABRICATION AB Resistance heating of the gasket strip in a gem-anvil high pressure cell was successful in obtaining sample temperatures up to 1100 degrees C, under pressures up to 4.0 GPa. The heating capabilities, as well as the mechanical and chemical stability, of several different gasket strips (two Ni-based alloys, Ta, Pt/Rh, and a Re/Mo alloy) with different design shapes, and two different single-crystal anvil materials (diamond and cubic zirconia) were investigated. Two gasket-strip designs were found to provide optimum uniform heating conditions while decreasing the required current needed to achieve 1100 degrees C. Two anvil systems were investigated to reduce the temperature increase of the pressure cell body. Cubic zirconia anvils reduced the cell-body temperature to 100 degrees C at sample temperatures up to 1100 degrees C. However, zirconia anvils often failed during heating and almost always failed during cooling. Diamond anvils with cubic zirconia mounting plates also permitted temperatures up to 1100 degrees C to be reached without anvil failure. However, the cell-body temperature increased to 300 degrees C. A sealed vacuum-type chamber was employed to eliminate the problem with gasket and anvil oxidation. The optimized operating parameters reported here provide a routine method for high temperature-high pressure studies. The method was used to densify and sinter nanosize amorphous silicon nitride and gamma-alumina powders at high temperatures and high pressures. [S0034-6748(99)03610-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. UFRGS, Inst Fis, Porto Alegre, RS, Brazil. RP Balzaretti, NM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Balzaretti, Naira/L-3417-2014 OI Balzaretti, Naira/0000-0003-2797-8618 NR 22 TC 4 Z9 4 U1 1 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1999 VL 70 IS 11 BP 4316 EP 4323 DI 10.1063/1.1150095 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 251NQ UT WOS:000083452100032 ER PT J AU Hobbie, EK De Reggi, AS AF Hobbie, EK De Reggi, AS TI Laser-pulse technique for measuring the thermal diffusivity of substrate-supported polymer films SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID THIN-FILMS; DIELECTRIC FILMS; MIRAGE TECHNIQUE; CONDUCTIVITY; ELECTRETS; SILICON AB We describe a technique for measuring the thermal diffusivity of substrate-supported polymer films based on the early-time electrothermal response following a 100 ns pulse from a Q-switched ruby laser. Data for a polyimide film spin coated on a p-doped Si[111] substrate are used to demonstrate the technique. From the late-time decay of the signal, we also obtain an estimate of the interfacial thermal-transport coefficient of the polymer-semiconductor interface. (C) 1999 American Institute of Physics. [S0034-6748(99)04111-8]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hobbie, EK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 21 TC 2 Z9 2 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1999 VL 70 IS 11 BP 4356 EP 4358 DI 10.1063/1.1150079 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 251NQ UT WOS:000083452100038 ER PT J AU Rabeony, M Garner, RT Elspass, CW Peiffer, DG Lin, M McElrath, KO Dias, JA Cross, JP AF Rabeony, M Garner, RT Elspass, CW Peiffer, DG Lin, M McElrath, KO Dias, JA Cross, JP TI Phase behavior of brominated poly(isobutylene-co-4-methylstyrene)/general purpose rubber blends SO RUBBER CHEMISTRY AND TECHNOLOGY LA English DT Article AB The thermodynamic interaction and phase behavior of elastomeric blends, specifically brominated poly(isobutylene-co-4-methylstyrene) and a general purpose rubber, polybutadiene, have been examined using small-angle neutron scattering (SANS) and cloud points measurements. The low molecular weight equivalent of each segment was used to produce a single phase blend from which the Flory-Huggins interaction parameter (chi) was extracted. The results were analyzed using the random copolymer formal ism. The results show that the "repulsive" interaction between the isobutylene and 4-methylstyrene monomer units enhances the compatibility of brominated poly(isobutylene-co-4-methylstyrene) with polybutadiene. A maximum in compatibility occurs at approximately 50 mol % 4-methylstyrene. This fundamental information is essential for the determination of the phase behavior of these materials, and their regions of miscibility/immiscibility. In addition, this information can be used to calculate the optimum copolymer composition for this scientifically interesting and technologically important blend system. C1 Exxon Res & Engn Co, Corp Res Sci Labs, Annandale, NJ 08801 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Exxon Chem Co, Baytown, TX 77522 USA. RP Rabeony, M (reprint author), Exxon Res & Engn Co, Corp Res Sci Labs, Route 22 E,Clinton Township, Annandale, NJ 08801 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC INC PI AKRON PA RUBBER DIV UNIV AKRON PO BOX 499, AKRON, OH 44309-0499 USA SN 0035-9475 J9 RUBBER CHEM TECHNOL JI Rubber Chem. Technol. PD NOV-DEC PY 1999 VL 72 IS 5 BP 910 EP 917 DI 10.5254/1.3538841 PG 8 WC Polymer Science SC Polymer Science GA V3325 UT WOS:000177532700008 ER PT J AU Denbo, DW AF Denbo, DW TI EPIC utilities for management, display & analysis of ocean data SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Seattle, WA USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD NOV PY 1999 VL 40 IS 11 BP 38 EP + PG 4 WC Engineering, Ocean SC Engineering GA 260FT UT WOS:000083939400005 ER PT J AU Booth, JC Vale, LR Ono, RH Claassen, JH AF Booth, JC Vale, LR Ono, RH Claassen, JH TI Predicting nonlinear effects in superconducting microwave transmission lines from mutual inductance measurements SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA ID INTERMODULATION AB We demonstrate the use of a new experimental technique based on mutual inductance measurements to quantitatively predict nonlinear effects in microwave devices fabricated from high-temperature superconductor (HTS) materials. The mutual inductance measurements yield the current dependence of the penetration depth lambda(J) in unpatterned HTS thin films. This information is used to calculate third-harmonic generation in coplanar waveguide (CPW) transmission lines and compares very well with actual measurements of CPW transmission lines of variable dimensions fabricated from YBa2Cu3O7-delta thin film samples. The mutual inductance measurements should prove extremely valuable as a screening technique for microwave applications of HTS materials that require very low nonlinear response. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. USN, Res Lab, Washington, DC 20375 USA. RP Booth, JC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 711 EP 713 DI 10.1088/0953-2048/12/11/306 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400006 ER PT J AU Claassen, JH Booth, JC Beall, JA Vale, LR Rudman, DA Ono, RH AF Claassen, JH Booth, JC Beall, JA Vale, LR Rudman, DA Ono, RH TI Comparison of microwave and mutual inductance measurements of the inductive nonlinearity of HTS thin films SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA AB A quadratic dependence of penetration depth on supercurrent density may be observed both by an inductive measurement on unpatterned films and by a microwave measurement of third-harmonic generation in coplanar waveguide. Results for the two methods are compared for a series of YBCO films. We find good agreement between the two measurements. C1 USN, Res Lab, Washington, DC 20375 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Claassen, JH (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 714 EP 716 DI 10.1088/0953-2048/12/11/307 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400007 ER PT J AU Sydow, JP Berninger, M Buhrman, RA Moeckly, BH AF Sydow, JP Berninger, M Buhrman, RA Moeckly, BH TI On the characteristic voltage of highly oxygenated YBCO grain boundary junctions SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA ID SCALING BEHAVIOR; YBA2CU3O7-DELTA AB Early in the study of cuprate grain boundary junctions (GBJs) it was observed that the junctions' characteristic voltage (IcRn) tended to scale, at least approximately, as J(c)(1/2). To re-examine the cause of this effect we have measured IcRn as a function of the more complete GBJ oxygenation that can be achieved by ozone annealing and electromigration. While these enhanced oxidation techniques can increase J(c). by up to a factor of 10, IcRn remains saturated at similar to 1.2 mV (at 4.2 K) for 24 degrees GBJs on strontium titanate bicrystals. Only with oxygen removal through inert gas annealing is scaling observed. These results can be explained by a model where the GBJ consist of a thin barrier layer, created by the localized cation disorder, sandwiched between two interface layers of non-uniform YBCO of highly variable oxygen deficiency. The barrier layer is largely unaffected by the enhanced oxidation techniques leading to the plateau in IcRn. Inhomogeneities in oxygen content and order within the interface layers are dependent on the quality of the grain boundary growth process and annealing history and in turn are responsible for the variations in IcRn leading to the previously observed scaling. Ozone anneals and electromigration reduces the oxygen inhomogeneities and electromigration reduces the oxygen inhomogeneities within the interface region, facilitating the measurement of the intrinsic IcRn of the grain boundary barrier layer. C1 Cornell Univ, Ithaca, NY USA. Conductus Inc, Sunnyvale, CA 94086 USA. RP Sydow, JP (reprint author), Univ Colorado, NIST, Boulder, CO 80309 USA. NR 6 TC 4 Z9 4 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 723 EP 725 DI 10.1088/0953-2048/12/11/310 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400010 ER PT J AU Shimakage, H Booth, JC Vale, LR Ono, RH AF Shimakage, H Booth, JC Vale, LR Ono, RH TI Third-harmonic generation from Y-Ba-Cu-O bicrystal Josephson junctions in coplanar waveguides SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA ID COUPLED GRAIN MODEL; FILMS AB We report harmonic generation from a bicrystal Josephson junction fabricated in the middle of a 50 Ohm coplanar waveguide (CPW). Microwave radiation was injected at one end of the CPW transmission line, and the fundamental and third-harmonic powers were measured. A decrease of the fundamental transmitted power related to thermal breakdown was observed. The third-harmonic output power from the junctions was a complicated function of the input power, showing many non-third order-effects. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Shimakage, H (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 830 EP 832 DI 10.1088/0953-2048/12/11/341 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400041 ER PT J AU Vale, LR Ono, RH McDonald, DG Phelan, RJ AF Vale, LR Ono, RH McDonald, DG Phelan, RJ TI Large-area YBa2Cu3O7-x bolometers on Si substrates SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA ID FILMS; SILVER AB We have developed YBa2Cu3O7-x (YBCO) thermometers for large-area (4 mm x 4 mm) electrical substitution bolometers. We passivated the YBCO with a thin Au layer and demonstrated a noise equivalent temperature of 4 nK Hz(-1/2). We then used a resistor layer of NiCr alloy deposited directly on the thermometer to perform optical measurements of the bolometer in the cryostat. Optical measurements show an electrical noise equivalent power of 87 pW Hz(-1/2) With a large thermal conductance of 1.87 x 10(-3) W K-1. These thermometers may be used as a real-time measurement radiometer. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Boulder Metr Inc, Boulder, CO 80303 USA. RP Vale, LR (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 856 EP 858 DI 10.1088/0953-2048/12/11/349 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400049 ER PT J AU Weber, C Ono, R Booth, JC Vale, L Benz, S Klushin, AM Kohlstedt, H Buchal, C Semerad, R AF Weber, C Ono, R Booth, JC Vale, L Benz, S Klushin, AM Kohlstedt, H Buchal, C Semerad, R TI Coplanar transmission lines with meandering centre conductors in Y-Ba-Cu-O/Au bilayers SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CA AB We have investigated both conventional and meandering coplanar microwave transmission lines patterned in Y-Ba-Cu-O/Au bilayers on yttria-stabilized zirconia and sapphire substrates. Within the meandering waveguides, the centre conductor was deformed from a straight line to a meander. Such a layout could be useful for metrological high-T(c) superconductor arrays, which are based on series arrays of shunted YBCO bicrystral junctions. The microwave properties of the lines were measured in the range 0-40 GHz at 76 K, using on-chip through-reflect-line calibrations. We discuss the measured attenuation in terms of conductor losses in the bilayers and show to what extent the disturbance of the line geometry affects the microwave properties. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Forschungszentrum Julich, D-52425 Julich, Germany. Tech Univ Munich, Dept Phys, D-85747 Garching, Germany. RP Weber, C (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 998 EP 1000 DI 10.1088/0953-2048/12/11/390 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400090 ER PT J AU Fan, SM Blaine, TL Sarmiento, JL AF Fan, SM Blaine, TL Sarmiento, JL TI Terrestrial carbon sink in the Northern Hemisphere estimated from the atmospheric CO2 difference between Manna Loa and the South Pole since 1959 SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID DIOXIDE; CIRCULATION; TRANSPORT; BUDGET; OCEAN; CYCLE; O-2; INVERSION; MODELS; HEAT AB The difference between Mauna Loa and South Pole atmospheric CO2 concentrations from 1959 to the present scales linearly with CO2 emissions from fossil fuel burning and cement production (together called fossil CO2). An extrapolation to zero fossil CO2 emission has been used to suggest that the atmospheric CO2 concentration at Mauna Loa was 0.8 ppm less than that at the South Pole before the industrial revolution, associated with a northward atmospheric transport of about 1 Gt C yr(-1) (Keeling er al., 1989a). Mass conservation requires an equal southward transport in the ocean. However, our ocean general circulation and biogeochemistry model predicts a much smaller pre-industrial carbon transport. Here, we present a new analysis of the Mauna Loa and South Pole CO2 data, using a general circulation model and a 2-box model of the atmosphere. It is suggested that the present CO2 difference between Mauna Loa and the South Pole is caused by, in addition to fossil CO2 sources and sinks, a pre-industrial interhemispheric flux of 0.5-0.7 Gt C yr(-1), and a terrestrial sink of 0.8-1.2 Gt C yr(-1) in the mid-latitude Northern Hemisphere, balanced by a tropical deforestation source that has been operating continuously in the period from 1959 to the present. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Sarmiento, JL (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. NR 35 TC 11 Z9 13 U1 2 U2 9 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD NOV PY 1999 VL 51 IS 5 BP 863 EP 870 DI 10.1034/j.1600-0889.1999.t01-4-00001.x PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 257VR UT WOS:000083803500001 ER PT J AU Beckman, BR Dickhoff, WW Zaugg, WS Sharpe, C Hirtzel, S Schrock, R Larsen, DA Ewing, RD Palmisano, A Schreck, CB Mahnken, CVW AF Beckman, BR Dickhoff, WW Zaugg, WS Sharpe, C Hirtzel, S Schrock, R Larsen, DA Ewing, RD Palmisano, A Schreck, CB Mahnken, CVW TI Growth, smoltification, and smolt-to-adult return of spring chinook salmon from hatcheries on the Deschutes River, Oregon SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Review ID JOHN-DAY-RESERVOIR; MIGRATING JUVENILE SALMONIDS; TROUT ONCORHYNCHUS-MYKISS; MESSENGER-RNA EXPRESSION; PLASMA THYROID-HORMONES; ATLANTIC SALMON; COHO SALMON; COLUMBIA RIVER; FACTOR-I; SEAWATER ADAPTATION AB The relationship between smoltification and smelt-to-adult return (SAR) of spring chinook salmon Oncorhynchus tshawytscha from the Deschutes River, Oregon, was examined for four release groups in each of three successive years. Fish were reared, marked with coded wire tags, and released from Round Butte Hatchery, Pelton Ladder rearing facility, and Warm Springs National Fish Hatchery. Smolt releases occurred in nearly the same place at similar times, allowing a direct comparison of SAR to several characters representing smolt quality. Return rates varied significantly among facilities, varying over an order of magnitude each year. The highest average SAR was from Pelton Ladder, the lowest was from Warm Springs. Each of the characters used as metrics of smoltification-fish size, spring growth rate (February-April), condition factor, plasma hormone concentration (thyroxine, cortisol, and insulin-like growth factor-I [IGF-I]), stress challenge, gill Na+,K+-ATPase activity, and liver glycogen concentration-varied significantly among facilities and seasonally within hatchery groups. However, only spring growth rate, gill ATPase activity, and plasma IGF-I concentration showed significant relationships to SAR. These characters and SAR itself were consistently lower for fish released from Warm Springs Hatchery than for fish from Round Butte Hatchery and Pelton Ladder. This demonstrates that differences in the quality of fish released by facilities may have profound effects on subsequent survival and suggests that manipulations of spring growth rate may be used to influence the quality of smolts released from facilities. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, Seattle, WA 98112 USA. Oregon State Univ, US Geol Survey, Biol Resources Div, Oregon Cooperat Fisheries Res Unit, Corvallis, OR 97331 USA. US Geol Survey, Biol Resources Div, Columbia River Res Stn, Cook, WA 98602 USA. Oregon Dept Fish & Wildlife, Corvallis, OR 97330 USA. US Geol Survey, Biol Resources Div, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fisheries Enhancement Program, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Beckman, BR (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 129 TC 64 Z9 65 U1 1 U2 27 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 1999 VL 128 IS 6 BP 1125 EP 1150 DI 10.1577/1548-8659(1999)128<1125:GSASTA>2.0.CO;2 PG 26 WC Fisheries SC Fisheries GA 351XD UT WOS:000089184000010 ER PT J AU Herbst, LH Jacobson, ER Klein, PA Balazs, GH Moretti, R Brown, T Sundberg, JP AF Herbst, LH Jacobson, ER Klein, PA Balazs, GH Moretti, R Brown, T Sundberg, JP TI Comparative pathology and pathogenesis of spontaneous and experimentally induced fibropapillomas of green turtles (Chelonia mydas) SO VETERINARY PATHOLOGY LA English DT Article DE Chelonia mydas; dermatitis; fibropapilloma; green turtles; herpesvirus; immunohistochemistry; tumor ID HUMAN-IMMUNODEFICIENCY-VIRUS; HERPES-SIMPLEX VIRUSES; CUTANEOUS FIBROPAPILLOMAS; HAWAIIAN-ISLANDS; GENE-EXPRESSION; RUN MECHANISM; SKIN-LESIONS; SEA TURTLES; INFECTION; SPIRORCHIDAE AB Tumor biopsy samples from 25 Floridian and 15 Hawaiian green turtles (Chelonia mydas) with spontaneous green turtle fibropapillomatosis (GTFP) and from 27 captive-reared,green turtles with experimentally induced GTFP were examined microscopically to differentiate the histologic features that result from GTFP pathogenesis and those that result from incidental factors that may vary according to geographic region. Common histologic features for spontaneous and experimentally induced tumors included fibroblast proliferation in the superficial dermis, epidermal acanthosis and hyperkeratosis, epidermal basal cell degeneration with dermal-epidermal cleft formation, spinous layer degeneration with intraepidermal vesicle and pustule formation, and ulceration. Visceral tumors, found in eight of 10 (80%) free-ranging turtles with cutaneous disease that were examined after death, had extensive interstitial fibrous proliferation. The presence of spirorchid trematode eggs and associated foreign body granulomas, common secondary findings within spontaneous tumors, varied by geographic location, and these findings were not observed in experimentally induced tumors. Eosinophilic intranuclear inclusions and intranuclear herpesvirus-associated antigen immunoreactivity were found in 18 of 38 (47%) experimentally induced cutaneous tumors and nine of 119 (7.5%) spontaneous tumors from Floridian but not Hawaiian turtles. The possible involvement of GTFP-associated herpesvirus in the pathogenesis of epidermal degenerative changes and GTFP pathogenesis is discussed. C1 Albert Einstein Coll Med, Inst Anim Studies, Dept Pathol, Bronx, NY 10461 USA. Univ Florida, Dept Small Anim Clin Sci, Gainesville, FL USA. Univ Florida, Dept Pathol & Lab Med, Gainesville, FL USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Turtle Hosp, Marathon, FL USA. Jackson Lab, Bar Harbor, ME 04609 USA. RP Herbst, LH (reprint author), Albert Einstein Coll Med, Inst Anim Studies, Dept Pathol, Room 1005 Ullman,1300 Morris Pk Ave, Bronx, NY 10461 USA. FU NCRR NIH HHS [RR07001] NR 66 TC 42 Z9 43 U1 0 U2 8 PU AMER COLL VET PATHOLOGIST PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0300-9858 J9 VET PATHOL JI Vet. Pathol. PD NOV PY 1999 VL 36 IS 6 BP 551 EP 564 DI 10.1354/vp.36-6-551 PG 14 WC Pathology; Veterinary Sciences SC Pathology; Veterinary Sciences GA 283NH UT WOS:000085281300004 PM 10568436 ER PT J AU Fields, RJ Shepherd, DA Cohen, A Kireta, AG AF Fields, RJ Shepherd, DA Cohen, A Kireta, AG TI Stress rupture of lead-free soldered joints used to assemble copper plumbing systems SO WELDING JOURNAL LA English DT Article; Proceedings Paper CT 1998 AWS Annual Meeting CY APR 26-30, 1998 CL DETROIT, MICHIGAN SP AWS DE stress rupture; solder; copper tubing; filler metal; shear strength; safety factor; lead-free; potable water AB A cooperative program on stress rupture behavior of lead-free soldered joints was initiated several years ago between the National institute of Standards and Technology (NIST) and the Copper Development Association (CDA). It was created because the conservative code-assigned joint strength properties of soldered wrought and cast copper and copper alloy fittings prohibited the broader use of copper plumbing tube in building construction. Further, there was a challenge to the use of the only remaining code-approved solder because of a health concern. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Arthur Cohen & Associates, Albuquerque, NM USA. Copper Dev Associat Inc, New York, NY USA. RP Fields, RJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 1 Z9 1 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 1999 VL 78 IS 11 BP 381S EP 386S PG 6 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 251CU UT WOS:000083427700026 ER PT J AU Maes, C Behringer, D AF Maes, C Behringer, D TI On a principal component analysis to estimate the upper oceanic variability of salinity: application to the western tropical Pacific Ocean SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE II FASCICULE A-SCIENCES DE LA TERRE ET DES PLANETES LA French DT Article DE physical oceanography; salinity; indirect method; sea level ID ASSIMILATION; MODEL AB We propose a new approach to estimate the vertical variability of the salinity field. The method is based on combined vertical modes of temperature and salinity, and reconstructs salinity profiles via a weighted least-squares procedure. The modes are defined as the empirical orthogonal functions along the water column. The major advantages of this new approach over using a simple T-S relationship are that interannual variability is better taken into account and that the method combines different sources of information such as temperature profiles and sea surface height in a consistent way. The present results estimate the salinity along 165 degrees E in the western Pacific Ocean for the 1993-1997 period and emphasize the importance of the salinity on sea level variability. ((C) 1999 Academie des sciences / Editions scientifiques et medicales Elsevier SAS.). C1 Natl Ctr Environm Predict, Washington, DC USA. RP Maes, C (reprint author), Natl Ctr Environm Predict, Washington, DC USA. RI maes, christophe/L-4049-2015 OI maes, christophe/0000-0001-6532-7141 NR 11 TC 0 Z9 0 U1 0 U2 0 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1251-8050 J9 CR ACAD SCI II A JI Comptes Rendus Acad. Sci. Ser II-A PD OCT 30 PY 1999 VL 329 IS 8 BP 597 EP 602 DI 10.1016/S1251-8050(00)87216-X PG 6 WC Geosciences, Multidisciplinary SC Geology GA 256WC UT WOS:000083748600007 ER PT J AU Marshall, TC Rust, WD Stolzenburg, M Roeder, WP Krehbiel, PR AF Marshall, TC Rust, WD Stolzenburg, M Roeder, WP Krehbiel, PR TI A study of enhanced fair-weather electric fields occurring soon after sunrise SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THUNDERSTORM CONVECTIVE REGIONS; PRECIPITATION; SYSTEMS AB In this paper we describe several series of electric field soundings made in the lowest few hundred meters above the ground on 6 days at Kennedy Space Center in Florida. These soundings are used to determine the charge density and thickness of the charged electrode layer just above the surface of the Earth both before and after sunrise during fair weather. On most of the days considered, there was an anomalous enhancement in the ground-level electric field that was probably associated with the "sunrise effect" previously described by others. At our tether site we found that the electrode-layer charge density began increasing at about the same time as the local enhancement in the electric field magnitude at the ground. Shortly before the peak in the local E enhancement, the electrode-layer charge density decreased while the charge thickness increased; these changes were coincident with a decrease in relative humidity, a shift in the average wind direction, and increases in the fluctuations in relative humidity, wind speed, and wind direction. The typical decrease in charge density was from 0.2 to 0.05 nC m(-3), while the charge layer thickness increased from less than 20 m to almost 200 m. Our measurements suggest that enhanced positive electrode layers accumulate before sunrise very close to the surface because there is relatively little radioactivity in the soil or air. Local, upward mixing of the denser, low-lying, electrode-layer charge may account for the observed sunrise enhancement in electric field. The larger enhancements observed at some sites may indicate that upward convection is supplemented by advection of denser charge from above water surfaces a few tens of meters (or less) from the measurement sites. C1 Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. NOAA, ERL, Natl Severe Storms Lab, Norman, OK 73069 USA. USAF, 45th Weather Squadron, Patrick AFB, FL 32925 USA. New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. RP Marshall, TC (reprint author), Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. EM marshall@phy.olemiss.edu; drust@nsslgate.nssl.noaa.gov; mstolzen@phy.olemiss.edu; william.roeder@pafb.af.mil; khrehbiel@ibis.nmt.edu OI Stolzenburg, Maribeth/0000-0001-8773-8101 NR 23 TC 16 Z9 18 U1 0 U2 1 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 OCT 27 PY 1999 VL 104 IS D20 BP 24455 EP 24469 DI 10.1029/1999JD900418 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 249KN UT WOS:000083332400017 ER PT J AU Bush, ABG Philander, SGH AF Bush, ABG Philander, SGH TI The climate of the Last Glacial Maximum: Results from a coupled atmosphere-ocean general circulation model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ICE-AGE CLIMATE; EQUATORIAL PACIFIC; SPECTRAL MODEL; YR BP; TEMPERATURE; RECORD; SIMULATION; SHEETS; PRODUCTIVITY; CONSTRAINTS AB Results from a coupled atmosphere-ocean general circulation model simulation of the Last Glacial Maximum reveal annual mean continental cooling between 4 degrees and 7 degrees C over tropical landmasses, up to 26 degrees of cooling over the Laurentide ice sheet, and a global mean temperature depression of 4.3 degrees C. The simulation incorporates glacial ice sheets, glacial land surface, reduced sea level, 21 ka orbital parameters, and decreased atmospheric CO2. Glacial winds, in addition to exhibiting anticyclonic circulations over the ice sheets themselves, show a strong cyclonic circulation over the northwest Atlantic basin, enhanced easterly flow over the tropical Pacific, and enhanced westerly flow over the Indian Ocean. Changes in equatorial winds are congruous with a westward shift in tropical convection, which leaves the western Pacific much drier than today but the Indonesian archipelago much wetter. Global mean specific humidity in the glacial climate is 10% less than today. Stronger Pacific easterlies increase the tilt of the tropical thermocline, increase the speed of the Equatorial Undercurrent, and increase the westward extent of the cold tongue, thereby depressing glacial sea surface temperatures in the western tropical Pacific by similar to 5 degrees-6 degrees C. C1 Univ Alberta, Dept Earth & Atmospher Sci, Edmonton, AB T6G 2E3, Canada. Princeton Univ, Program Atmospher & Ocean Sci, Dept Geosci, Princeton, NJ 08544 USA. RP Bush, ABG (reprint author), Univ Alberta, Dept Earth & Atmospher Sci, 126 Earth Sci Bldg, Edmonton, AB T6G 2E3, Canada. EM andrew.bush@ualberta.ca; gphlder@splash.princeton.edu NR 54 TC 77 Z9 78 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 27 PY 1999 VL 104 IS D20 BP 24509 EP 24525 DI 10.1029/1999JD900447 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 249KN UT WOS:000083332400021 ER PT J AU Frey, RA Baum, BA Menzel, WP Ackerman, SA Moeller, CC Spinhirne, JD AF Frey, RA Baum, BA Menzel, WP Ackerman, SA Moeller, CC Spinhirne, JD TI A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2 slicing SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIATION BUDGET; CIRRUS CLOUDS; CLIMATE; SENSITIVITY; PARAMETERS; SOUNDER; VAS AB Data from two instruments onboard the National Aeronautics and Space Administration (NASA) ER-2 high-altitude aircraft have been utilized in the largest validation study to date in assessing the accuracy of the CO2-slicing cloud height algorithm. Infrared measurements of upwelling radiance from the MODIS (Moderate-Resolution Imaging Spectroradiometer) airborne simulator (MAS) were used to generate cloud top heights and then compared to those derived from the Cloud Lidar System (CLS), operating with dual polarization at 0.532 mu m. The comparisons were performed for 10 flight days during the Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS) field experiment during April and May 1996 which included various singlelayer and multilayer cloud conditions. Overall, the CO2-slicing method retrieved cloud heights to within +/-500 m and to within +/-1500 m of the lidar heights in 32 and 64% of the cases, respectively, From a simulation of cloud height errors as a function of various error sources in the CO2-slicing algorithm: it was concluded that the problem of multilayer clouds is secondary to that of proper specification of clear-sky radiances. C1 Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23665 USA. NOAA, NESDIS, Satellite Applicat Lab, Madison, WI 53706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Frey, RA (reprint author), Univ Wisconsin, Ctr Space Sci & Engn, 1225 W Dayton St,Room 219, Madison, WI 53706 USA. EM richard.frey@ssec.wisc.edu RI Menzel, W. Paul/B-8306-2011; Ackerman, Steven/G-1640-2011; Baum, Bryan/B-7670-2011 OI Menzel, W. Paul/0000-0001-5690-1201; Ackerman, Steven/0000-0002-4476-0269; Baum, Bryan/0000-0002-7193-2767 NR 25 TC 45 Z9 47 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 27 PY 1999 VL 104 IS D20 BP 24547 EP 24555 DI 10.1029/1999JD900796 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 249KN UT WOS:000083332400023 ER PT J AU Carasso, AS AF Carasso, AS TI Linear and nonlinear image deblurring: A documented study SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE image deblurring; nonsmooth images; biomedical imaging; Bayesian methods; Poisson noise; maximum likelihood; maximum a posteriori; maximum entropy; divergent algorithms; Lucy-Richardson method; E-M algorithm; VanCittert's method; slow evolution from the continuation boundary method; error bounds; numerical experiments ID MAXIMUM-ENTROPY; BAYESIAN RECONSTRUCTION; EMISSION TOMOGRAPHY; FEASIBLE IMAGES; RESTORATION; ALGORITHMS; REGULARIZATION; INFORMATION; LIKELIHOOD AB Nonlinear image deblurring procedures based on probabilistic considerations are widely believed to outperform conventional linear methods. This paper is exclusively concerned with nonsmooth images such as those that occur in biomedical imaging, where reconstruction of high frequency detail is of prime interest, and where avoidance of a priori smoothness constraints is a major concern. The theoretical basis behind each of the following nonlinear procedures is examined: the Lucy-Richardson method, the maximum likelihood E-M algorithm, the Poisson maximum a posteriori method, and the Nunez-Llacer version of the maximum entropy method. A linear iterative method, VanCittert's iteration, is also studied. It is shown that each of the first three methods, as well as VanCittert's method, lack a necessary ingredient for successful solution of the ill-posed deblurring problem, while in the maximum entropy method, the enforced smoothness may have adverse consequences in medical imaging. A direct linear method, the slow evolution from the continuation boundary (SECB) method, designed specifically for nonsmooth images, is also considered. That method is stabilized by constraining the blurring operator as well as the solution and does not require smoothness constraints. It is shown that useful error estimates can be obtained in the SECB method while this is impossible in Tikhonov's method without a priori bounds on derivatives of the unknown solution. Reconstruction experiments on low noise synthetic MRI data show that thousands of iterations are necessary to achieve sufficient resolution in the iterative procedures. However, the SECB method provides higher resolution at considerable savings in computer time. At high noise levels, the iterative algorithms are shown to diverge. At these same noise levels, the SECB method produces reconstructions comparable in quality to those that would be obtained in the iterative methods, were one able to terminate the divergent algorithm at that iteration which best approximates the true solution in the L-1 norm. C1 Natl Inst Stand & Technol, Div Math & Computat Sci, Gaithersburg, MD 20899 USA. RP Carasso, AS (reprint author), Natl Inst Stand & Technol, Div Math & Computat Sci, Gaithersburg, MD 20899 USA. NR 37 TC 63 Z9 66 U1 0 U2 5 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PD OCT 27 PY 1999 VL 36 IS 6 BP 1659 EP 1689 DI 10.1137/S0036142997320413 PG 31 WC Mathematics, Applied SC Mathematics GA 252HC UT WOS:000083495200001 ER PT J AU Ogi, H Tsujimoto, A Hirao, M Ledbetter, H AF Ogi, H Tsujimoto, A Hirao, M Ledbetter, H TI Stress-dependent recovery of point defects in deformed aluminum: An acoustic-damping study SO ACTA MATERIALIA LA English DT Article DE acoustic methods; aluminum; diffusion; dislocation mobility; noncontacting evaluation ID ULTRASONIC-ATTENUATION; LUBRICATION AGENTS; DISLOCATION-MOTION; COUPLING TECHNIQUE; PURE ALUMINUM; RESONANCE AB The stress dependence of point-defect diffusion to dislocations in a 99.99% polycrystalline aluminum was studied using shear-wave attenuation and phase velocity. By holding the stress after deformation, attenuation and velocity approach their nonstressed values. The holding stress was varied between 0 and 12 MPa, after applying a 15 MPa compressive stress. Time-independent attenuation and stress-induced velocity change were introduced into the Granato-Hikata-Lucke theory, which first established the change of attenuation and velocity caused by the point-defect diffusion to dislocations. Good agreement was found between measurements and the modified theory. The stress dependence of the recovery rate was interpreted as a reduction of the migration energy of point defects diffusing to dislocations, and the activation volume was calculated for uniaxial stress. Electromagnetic acoustic resonance (EMAR) was used for the measurements. Being noncontact and highly sensitive, EMAR permitted detailed measurement of the attenuation and velocity evolutions during the unloading-holding stress sequence. Published by Elsevier Science Ltd on behalf of Acta Merallurgica Inc. C1 Osaka Univ, Grad Sch Engn Sci, Toyonaka, Osaka 5608531, Japan. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Ogi, H (reprint author), Osaka Univ, Grad Sch Engn Sci, Machikaneyama 1-3, Toyonaka, Osaka 5608531, Japan. NR 32 TC 14 Z9 14 U1 1 U2 4 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 26 PY 1999 VL 47 IS 14 BP 3745 EP 3751 DI 10.1016/S1359-6454(99)00251-7 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 254DM UT WOS:000083596700002 ER PT J AU Parker, CA Roberts, JC Bedair, SM Reed, MJ Liu, SX El-Masry, NA Robins, LH AF Parker, CA Roberts, JC Bedair, SM Reed, MJ Liu, SX El-Masry, NA Robins, LH TI Optical band gap dependence on composition and thickness of InxGa1-xN (0 < x < 0.25) grown on GaN SO APPLIED PHYSICS LETTERS LA English DT Article AB Band gap measurements have been carried out in strained and relaxed InxGa1-xN epilayers with x < 0.25. Values of x were determined from x-ray diffraction of relaxed films. The lowest energy absorption threshold, measured by transmittance, was found to occur at the same energy as the peak of the photoluminescence spectrum. Bowing parameters for both strained and relaxed films were determined to be 3.42 and 4.11 eV, respectively. The dependence of the band gap shift, Delta E-g, on strain is presented. (C) 1999 American Institute of Physics. [S0003-6951(99)04844-5]. C1 N Carolina State Univ, Dept Elect & Comp Engn, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Parker, CA (reprint author), N Carolina State Univ, Dept Elect & Comp Engn, Box 7911, Raleigh, NC 27695 USA. NR 12 TC 68 Z9 71 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 25 PY 1999 VL 75 IS 17 BP 2566 EP 2568 DI 10.1063/1.125079 PG 3 WC Physics, Applied SC Physics GA 246VQ UT WOS:000083185900016 ER PT J AU Matthews, MR Anderson, BP Haljan, PC Hall, DS Holland, MJ Williams, JE Wieman, CE Cornell, EA AF Matthews, MR Anderson, BP Haljan, PC Hall, DS Holland, MJ Williams, JE Wieman, CE Cornell, EA TI Watching a superfluid untwist itself: Recurrence of rabi oscillations in a Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE; STATE; EXCITATIONS; ROTATION; COUPLER; ATOMS AB The order parameter of a condensate with two internal states can continuously distort in such a way as to remove twists that have been imposed along its length. We observe this effect experimentally in the collapse and recurrence of Rabi oscillations in a magnetically trapped, two-component Bose-Einstein condensate of Rb-87. C1 Univ Colorado, JILA, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Matthews, MR (reprint author), Univ Colorado, JILA, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RI Anderson, Brian/A-2286-2009 OI Anderson, Brian/0000-0002-0442-7867 NR 28 TC 172 Z9 172 U1 2 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 25 PY 1999 VL 83 IS 17 BP 3358 EP 3361 DI 10.1103/PhysRevLett.83.3358 PG 4 WC Physics, Multidisciplinary SC Physics GA 247VZ UT WOS:000083242800004 ER PT J AU Jach, T Gormley, J Thurgate, S AF Jach, T Gormley, J Thurgate, S TI Grazing incidence X-ray photoemission spectroscopy of SiO2 on Si SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article; Proceedings Paper CT 7th Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods (TXRF 98) CY SEP, 1998 CL AUSTIN, TEXAS DE grazing incidence; X-ray photoemission spectroscopy; XPS; thin films; total external reflection ID MEAN FREE PATHS; PHOTOELECTRON-SPECTROSCOPY; OXIDIZED GAAS(100); 50-2000-EV RANGE; REFLECTION AB We have applied grazing incidence X-ray photoemission spectroscopy to the determination of the thickness of SiO2 layers on Si, as well as surface carbon that is present. The measurements take advantage of the different optical constants of the layers. X-rays incident on the surface at grazing angle undergo total external reflection, where the fields in each layer are subject to highly non-linear changes as a function of incidence angle. X-ray photoemission excited by these fields gives information on atomic species, chemical state, and layer thickness. Simultaneous fits are made to the photoemission spectra in each layer. The method is illustrated for a thermally grown oxide layer and a native oxide on Si. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Murdoch Univ, Murdoch, WA 6150, Australia. Natl Synchrotron Light Source Dept, Upton, NY USA. RP Jach, T (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD OCT 25 PY 1999 VL 54 IS 10 BP 1539 EP 1544 DI 10.1016/S0584-8547(99)00103-2 PG 6 WC Spectroscopy SC Spectroscopy GA 251FH UT WOS:000083433600020 ER PT J AU Thorn, RP Stief, LJ Buckley, TJ Johnson, RD Monks, PS Klemm, RB AF Thorn, RP Stief, LJ Buckley, TJ Johnson, RD Monks, PS Klemm, RB TI Photoionization efficiency spectrum and ionization energy of OBrO SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID BROMINE DIOXIDE; THERMOCHEMISTRY; STRATOSPHERE; SYSTEM; BR2O; HEAT AB The photoionization efficiency (PIE) spectrum of OBrO was measured over the wavelength range lambda = 86-126 nm using a discharge flow-photoionization mass spectrometer (DF-PIMS) apparatus coupled to a VUV synchrotron radiation source. Bromine dioxide was generated in a flow tube reactor by first forming BrO via the reaction O(P-3) + Br-2 and then allowing the BrO to react on the cold flow tube wall. The PIE spectrum of the BrO reactant was obtained and the photoionization threshold evaluated from the half-rise point of the step at threshold. This remeasurement yields IE(BrO) = 10.48 +/- 0.02 eV, which supersedes our previous result. The PIE spectrum of OBrO displayed steplike behavior near threshold. A value of 10.29 +/- 0.03 eV was obtained for the adiabatic ionization energy (IE) of OBrO from analysis of the photoionization threshold at lambda = 120.5 nn. An ab initio determination of the IE of OBrO using the CCSD(T)/6-311+G(3dF)//CCD/6-311+G(3df) level of theory gives a value of 10.26 +/- 0.06 eV, which is in excellent agreement with the experimental result. The results are compared with previous determinations of the IE for both halogen monoxides, XO, and halogen dioxides, OXO (X = Cl, Br, I). C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Univ Leicester, Dept Chem, Leicester LE1 7RH, Leics, England. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Thorn, RP (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 33 TC 9 Z9 9 U1 1 U2 2 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 21 PY 1999 VL 103 IS 42 BP 8384 EP 8388 DI 10.1021/jp991555n PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 251DT UT WOS:000083429900006 ER PT J AU Fahr, A Laufer, AH Tardy, DC AF Fahr, A Laufer, AH Tardy, DC TI Pressure effect on CH3 and C2H3 cross-radical reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID RECOMBINATION REACTION CH3+CH3->C2H6; ENERGY-TRANSFER; VINYL RADICALS; RATE-CONSTANT; PHOTOCHEMISTRY; PRODUCT; ATMOSPHERE; KINETICS; METHYL; FLAMES AB The effect of pressure on the cross-radical reactions of vinyl and methyl radicals has been investigated. These radicals were produced by excimer laser photolysis of methyl vinyl ketone (CH3COC2H3) at 193 nm. The reaction products were detected and analyzed using a sensitive gas chromatograph and mass spectrometer. The study covered a pressure range from about 0.28 kPa (2.1 Torr) to 27 kPa (200 Torr) at 298 K. The yield of propylene (C3H6), the cross-combination product of methyl and vinyl radicals, was compared to the yield of ethane (C2H6), the methyl radical combination product. At 27 kPa [C3H6]/[C2H6] = 1.28 was derived. This ratio, was reduced to about 0.75 when the pressure was reduced to about 0.28 kPa. Kinetic modeling results indicated that the contribution of the combination reaction C2H3 + CH3 + M --> C3H6 + M to the total cross-radical reactions is reduced from 78% at high pressures (27 kPa) to about 39% at low pressures (0.28 kPa). At low pressures an additional reaction channel, C2H3 + CH3 --> C3H5 + H, becomes available, producing a host of allyl radical reaction products including 1,5-hexadiene, the allyl radical combination product. The observed 1,5-hexadiene is strong evidence for allyl radical formation at low pressures, presumably from the decomposition of the chemically activated C3H6 Macroscopic and microscopic modeling of product yields and their pressure dependencies were used to interpret the experimental observations. Results of master equation calculations using weak colliders and RRKM theory are in agreement with the observed pressure dependence of the combination reactions. It has been shown that the chemically activated species can undergo unimolecular processes that are competitive with collisional stabilization. The pressure dependence for the unimolecular steps appears as a pressure dependence of the combination/disproportionation ratio. The apparent pathological behavior in this unsaturated system is attributed to the formation of a stronger C-C bond as contrasted to the weaker C-C bond formed from combination of saturated hydrocarbon radicals. This C-C bond strength is sufficiently high for the chemically activated propylene, produced from the methyl and vinyl cross-combination reaction to cleave the allyl C-H bond or isomerize to cyclopropane. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Univ Iowa, Dept Chem, Iowa City, IA 52242 USA. RP Fahr, A (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 35 TC 25 Z9 25 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 OCT 21 PY 1999 VL 103 IS 42 BP 8433 EP 8439 DI 10.1021/jp9923522 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 251DT UT WOS:000083429900012 ER PT J AU Daniel, JS Solomon, S Portmann, RW Garcia, RR AF Daniel, JS Solomon, S Portmann, RW Garcia, RR TI Stratospheric ozone destruction: The importance of bromine relative to chlorine SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DEPLETION AB The relative effectiveness of bromine compared to chlorine for destroying stratospheric ozone is explored. Two definitions previously used to quantify this relative effectiveness, typically referred to as alpha, are compared and a definition is presented to calculate alpha values applicable for column and global ozone loss. Calculations of alpha are made with a two-dimensional radiative/chemical/dynamical model and suggest that bromine is roughly 45 times more effective than chlorine for global ozone destruction. The physical processes underlying this result are probed, and sensitivity studies are presented that show that relatively large changes invoked in the modeled transport and heterogeneous chemistry lead to changes in this value of <15%. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Daniel, JS (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM jdaniel@al.noaa.gov RI Portmann, Robert/C-4903-2009; Daniel, John/D-9324-2011 OI Portmann, Robert/0000-0002-0279-6087; NR 16 TC 71 Z9 72 U1 0 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1999 VL 104 IS D19 BP 23871 EP 23880 DI 10.1029/1999JD900381 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246WT UT WOS:000083188400019 ER PT J AU Reinsel, GC Tiao, GC Miller, AJ Nagatani, RM Wuebbles, DJ Weatherhead, EC Cheang, WK Zhang, L Flynn, LE Kerr, JB AF Reinsel, GC Tiao, GC Miller, AJ Nagatani, RM Wuebbles, DJ Weatherhead, EC Cheang, WK Zhang, L Flynn, LE Kerr, JB TI Update of Umkehr ozone profile data trend analysis through 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE AB An extended update of both nonseasonal and seasonal trend analysis for northern hemisphere Umkehr ozone profile data from 1977 through 1997 is presented. The nonseasonal or year-round trend analysis reaffirms the previous results of significant negative ozone trend in the upper stratospheric Umkehr layers 7, 8, and 8-10 (33-48 km) of about -0.5% per year, with little trend in the middle stratospheric layer 5 (24-28 km). In addition, the Umkehr data show a substantial negative trend in the lower stratospheric Umkehr layer 2-3 (10-19 km) of about -0.4% per year. Two procedures for the correction of the Umkehr measurements for errors due to volcanic aerosols are considered, and trend results are quite similar using both aerosol-correction procedures. With respect to the seasonal trend aspects, the analysis indicates relatively small trend differences over seasons in the upper layers, where trends in the winter and spring seasons are only slightly more negative than those in the summer and fall seasons, by about -0.1% per year. In the lower stratospheric layer 2-3, however, a strong seasonal pattern in trends is observed in the midlatitude Umkehr data, with the most extreme negative trends, of about -0.6% per year, occurring in the spring and winter, the least negative tr ends, of about -0.2% per year, occurring in the fall, and the summer trends of about -0.4% per year are intermediate. Also, the trends in layer 2-3 are substantially more negative for the higher latitude range of 40-52 degrees N than for the lower latitude range of 26-39 degrees N, by about -0.3% per year during all seasons, with even larger differences in the spring. C1 Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. Univ Chicago, Grad Sch Business, Chicago, IL 60637 USA. NOAA, Natl Weather Serv, NCEP, Climat Predict Ctr, Camp Springs, MD 20233 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA. NOAA, NESDIS, Silver Spring, MD 20910 USA. Atmospher Environm Serv, Downsview, ON M3H 5T4, Canada. RP Reinsel, GC (reprint author), Univ Wisconsin, Dept Stat, 1210 W Dayton St, Madison, WI 53706 USA. EM reinsel@stat.wisc.edu; gct@gsbgct.uchicago.edu; miller@climon.wwb.noaa.gov; wuebbles@atmos.uiuc.edu; betsy@srrb.noaa.gov; lflynn@nesdis.noaa.gov; jim.kerr@ec.gc.ca RI Flynn, Lawrence/B-6321-2009; Weatherhead, Elizabeth/I-7091-2015 OI Flynn, Lawrence/0000-0001-6856-2614; Weatherhead, Elizabeth/0000-0002-9252-4228 NR 12 TC 13 Z9 13 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 20 PY 1999 VL 104 IS D19 BP 23881 EP 23898 DI 10.1029/1999JD900380 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246WT UT WOS:000083188400020 ER PT J AU Poirier, GE Herne, TM Miller, CC Tarlov, MJ AF Poirier, GE Herne, TM Miller, CC Tarlov, MJ TI Molecular-scale characterization of the reaction of ozone with decanethiol monolayers on Au(111) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SCANNING-TUNNELING-MICROSCOPY; TRANSFORM MASS-SPECTROMETRY; ALKANETHIOL MONOLAYERS; GOLD SURFACES; OXIDATION; PHOTOOXIDATION; SUBSTRATE; MECHANISM; AU(001) AB The chemical reaction of ozone with decanethiol monolayers on Au(111) was characterized using X-ray photoelectron spectroscopy and scanning tunneling microscopy. Our results show that exposure to ozone results in oxidation of the thiol terminus. The reaction initiates at the domain boundary network of the alkanethiol monolayer and propagates into the domains. Above a threshold surface oxygen content, the monolayer converts to a two-dimensional fluid that can subsequently recrystallize to a commensurate monolayer of partially oxidized thiol. Further exposure to ozone results in conversion of the monolayer to a fluid phase and a 10% to 30% expansion of the Au lattice at the Au-thiol interface with concomitant formation of Au islands. Our results demonstrate that crystallographic defects in monolayer films can play an important role in their chemical reactions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Poirier, GE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 39 TC 42 Z9 42 U1 1 U2 10 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 20 PY 1999 VL 121 IS 41 BP 9703 EP 9711 DI 10.1021/ja991739f PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 248MV UT WOS:000083280100027 ER PT J AU Tarek, M Tobias, DJ AF Tarek, M Tobias, DJ TI Environmental dependence of the dynamics of protein hydration water SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NEUTRON-SCATTERING; MYOGLOBIN; SOLVENT; BACTERIORHODOPSIN; FLUCTUATIONS; TRANSITION; SIMULATION; DIFFUSION; MOTIONS C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Tobias, DJ (reprint author), Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RI Tobias, Douglas/B-6799-2015 NR 29 TC 55 Z9 56 U1 0 U2 5 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 20 PY 1999 VL 121 IS 41 BP 9740 EP 9741 DI 10.1021/ja990643i PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 248MV UT WOS:000083280100038 ER PT J AU Topp, A Bauer, BJ Klimash, JW Spindler, R Tomalia, DA Amis, EJ AF Topp, A Bauer, BJ Klimash, JW Spindler, R Tomalia, DA Amis, EJ TI Probing the location of the terminal groups of dendrimers in dilute solution SO MACROMOLECULES LA English DT Article ID POLY(AMIDO AMINE) DENDRIMERS; NMR RELAXATION PARAMETERS; ANGLE NEUTRON-SCATTERING; STANDARDS-AND-TECHNOLOGY; STARBURST DENDRIMERS; CHAIN DYNAMICS; MONTE-CARLO; MOLECULES; POLYMERS; CHEMISTRY AB The spatial distribution of the terminal groups of poly(amido amine) dendrimers have been determined experimentally by small-angle neutron scattering with deuterium labeling and scattering contrast variation. The radius of gyration of deuterated terminal units of generation 7 dendrimers is 39.3 +/- 1.0 Angstrom. This is significantly larger than the radius of gyration of the whole dendrimer, which is 34.4 +/- 0.2 Angstrom. These data indicate that dendrimers have terminal groups that; are concentrated near the periphery. These results are inconsistent with many computer simulations and some molecular models. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Michigan Mol Inst, Midland, MI 48640 USA. RP Amis, EJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 41 TC 91 Z9 92 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 19 PY 1999 VL 32 IS 21 BP 7226 EP 7231 DI 10.1021/ma990125s PG 6 WC Polymer Science SC Polymer Science GA 247LR UT WOS:000083222700047 ER PT J AU Topp, A Bauer, BJ Tomalia, DA Amis, EJ AF Topp, A Bauer, BJ Tomalia, DA Amis, EJ TI Effect of solvent quality on the molecular dimensions of PAMAM dendrimers SO MACROMOLECULES LA English DT Article ID STARBURST DENDRIMERS; POLYMERS; CHEMISTRY AB The average dimensions of poly(amido amine) (PAMAM) dendrimers of generations G5 and G8 are studied by small-angle neutron scattering (SANS) asa function of solvents of differing quality, the composition of mixtures of a good solvent and a nonsolvent, and temperature. The radius of gyration, R-g, of the G8 dendrimer decreases for the series of solvents D(CD2)(m)OD (with m = 0, 1, 2, 4) by approximately 10% from m = 0 to m= 4 with decreasing solvent quality. The average segment density in solution is calculated for G5 and Gs. The size of PAMAM dendrimers, as reflected by R-g, is not influenced by the composition of mixtures of methyl alcohol/acetone in the full range of solubility of the dendrimers. In the temperature range =10 degrees C less than or equal to T less than or equal to 50 degrees C,the dimensions of the G8 and G5 dendrimer are constant, within approximate to 5% of each other. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Michigan Mol Inst, Midland, MI 48640 USA. RP Amis, EJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 92 Z9 92 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 OCT 19 PY 1999 VL 32 IS 21 BP 7232 EP 7237 DI 10.1021/ma9901240 PG 6 WC Polymer Science SC Polymer Science GA 247LR UT WOS:000083222700048 ER PT J AU Xie, YF Byrd, RH AF Xie, YF Byrd, RH TI Practical update criteria for reduced hessian SQP: Global analysis SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE constrained optimization; nonlinear programming; quasi-Newton methods; reduced Hessian algorithms; successive quadratic programming ID NONLINEARLY CONSTRAINED OPTIMIZATION; QUASI-NEWTON METHODS; ALGORITHMS AB In this paper, a new update criterion is proposed to improve the Nocedal-Overton update criterion for reduced Hessian successive quadratic programming (SQP). Global and R-linear convergence is proved for the new criterion and the Nocedal-Overton criterion using nonorthogonal basis matrices, which allow efficient implementations of the reduced Hessian SQP for solving large-scale equality constrained problems. C1 NOAA, ERL, FSL, Forecast Syst Lab, Boulder, CO 80303 USA. Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. RP Xie, YF (reprint author), NOAA, ERL, FSL, Forecast Syst Lab, 325 Broadway, Boulder, CO 80303 USA. RI Xie, Yuanfu/G-4413-2015 NR 14 TC 5 Z9 8 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PD OCT 19 PY 1999 VL 9 IS 3 BP 578 EP 604 DI 10.1137/S105262349427861X PG 27 WC Mathematics, Applied SC Mathematics GA 246CN UT WOS:000083146400002 ER PT J AU Hagley, EW Deng, L Kozuma, M Trippenbach, M Band, YB Edwards, M Doery, M Julienne, PS Helmerson, K Rolston, SL Phillips, WD AF Hagley, EW Deng, L Kozuma, M Trippenbach, M Band, YB Edwards, M Doery, M Julienne, PS Helmerson, K Rolston, SL Phillips, WD TI Measurement of the coherence of a Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATOMS; GAS AB We present experimental and theoretical studies of the coherence properties of a Bose-Einstein condensate (BEC) using an interference technique. Two optical standing wave pulses of duration 100 ns and separation Delta t are applied to a condensate. Each standing wave phase grating makes small copies of the condensate displaced in momentum space. The quantum mechanical amplitudes of each copy interfere, depending on Delta t and on spatial phase variations across the condensate. We find that the behavior of a trapped BEC is consistent with a uniform spatial phase. A released BEG, however, exhibits large phase variation across the condensate. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ben Gurion Univ Negev, Dept Chem & Phys, IL-84105 Beer Sheva, Israel. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. Univ Warsaw, Inst Expt Phys, Opt Div, PL-00681 Warsaw, Poland. RP Hagley, EW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr Stop 8424, Gaithersburg, MD 20899 USA. RI Deng, Lu/B-3997-2012; Hagley, Edward/B-4285-2012; Helmerson, Kristian/E-3683-2013; rolston, steven/L-5175-2013; Julienne, Paul/E-9378-2012 OI rolston, steven/0000-0003-1671-4190; Julienne, Paul/0000-0002-5494-1442 NR 21 TC 145 Z9 148 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 OCT 18 PY 1999 VL 83 IS 16 BP 3112 EP 3115 DI 10.1103/PhysRevLett.83.3112 PG 4 WC Physics, Multidisciplinary SC Physics GA 245XH UT WOS:000083133200003 ER PT J AU Arnold, CS Pappas, DP Popov, AP AF Arnold, CS Pappas, DP Popov, AP TI Second- and first-order phase transitions in the magnetic reorientation of ultrathin Fe on Gd SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-REORIENTATION; FERROMAGNETIC-FILMS; THICKNESS-DRIVEN; ANISOTROPY; LAYERS AB Ultrathin Fe films grown on the Gd(0001) surface exhibit a magnetic in-plane to out-of-plane spin-reorientation transition with increasing temperature. We provide evidence that this reorientation transition is accomplished in two steps. The first step, at low temperature, is a continuous reorientation of the surface moment from in-plane to canted out-of-plane with a corresponding peak in the susceptibility. The second step is a thermally irreversible rotation from this canted direction to perpendicular to the film plane. These two steps therefore have the characteristic signatures of second- and first-order phase transitions, respectively. C1 Natl Inst Stand & Technol, Boulder, CO USA. Moscow State Engn Phys Inst, Moscow, Russia. RP Arnold, CS (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO USA. NR 32 TC 43 Z9 43 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 18 PY 1999 VL 83 IS 16 BP 3305 EP 3308 DI 10.1103/PhysRevLett.83.3305 PG 4 WC Physics, Multidisciplinary SC Physics GA 245XH UT WOS:000083133200051 ER PT J AU Verkouteren, RM AF Verkouteren, RM TI Preparation, characterization, and value assignment of carbon dioxide isotopic reference materials: RMs 8562, 8563, and 8564 SO ANALYTICAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; PHOSPHORIC-ACID; OXYGEN; FRACTIONATION; PRECISION AB Three carbon dioxide isotopic reference materials (RM 8562, RM 8563, and RM 8564) have been prepared and characterized for composition, heterogeneity, and stability using dual-inlet isotope ratio mass spectrometry, RMs 8562-8564 are not certified, but their use as proxies for carbonate standards allows users to realize precisely the Vienna PDB scale and to provide comparability of stable carbon and oxygen isotope ratio data obtained by investigators in different laboratories. Samples (similar to 400 mu mol each) are sealed in borosilicate glass tubes (9-mm outer diameter) for distribution by the National Institute of Standards and Technology (NIST) and the International Atomic Energy Agency (IAEA). delta(13)C and delta(18)O value assignments and uncertainties for the CO2 RMs were determined by two complementary methods: (1) through an international comparison exercise, to allow single-point standardization onto the VPDB scale and (2) through isotopically verified measurements of relative (Delta delta) values between RMs (Delta delta(45)CO(2), Delta delta(46)CO(2), and Delta delta(47)CO(2)). The intercomparison exercise involved thirteen international laboratories; measurements were normalized by carbonate and other RMs. The Delta delta values were measured at NIST, where instrument design and measurement protocols allowed isotopically consistent determinations of delta(45)CO(2), delta(46)CO(2), and delta(47)CO(2), a necessary condition of measurement accuracy. The value assignments (and combined standard uncertainties) for the delta(13)C(VPDB) and delta(18)O(VPDB) values are, respectively, -3.76 parts per thousand (0.03 parts per thousand) and -8.45 parts per thousand (0.11 parts per thousand) for RM 8562, -41.56 parts per thousand (0.06 parts per thousand) and -23.72 parts per thousand (0.11 parts per thousand) for RM 8563, and -10.45 parts per thousand (0.04 parts per thousand) and +0.19 parts per thousand (0.10 parts per thousand) for RM 8564. Within any batch (each consisting of over 1000 samples), sample-to-sample isotopic variations (standard deviations) were measured to be less than 0.007 parts per thousand and 0.026 parts per thousand for delta(13)C and delta(18)O, respectively. No conclusive evidence of long-term isotopic drift in these RMs has been observed after two years of monitoring. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Verkouteren, RM (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 29 TC 17 Z9 17 U1 0 U2 2 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 1999 VL 71 IS 20 BP 4740 EP 4746 DI 10.1021/ac990233c PG 7 WC Chemistry, Analytical SC Chemistry GA 247GH UT WOS:000083212400046 ER PT J AU Li, JY Dunn, ML Ledbetter, H AF Li, JY Dunn, ML Ledbetter, H TI Thermoelectroelastic moduli of textured piezoelectric polycrystals: Exact solutions and bounds for film textures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CONSTANTS AB Conditions are given for the existence of exact solutions for the effective thermal and electroelastic moduli of polycrystals exhibiting fiber texture. The exact solutions are then developed through the consideration of a class of uniform fields in a polycrystal acted upon by various external thermal and electroelastic loadings. These exact results are verified by direct orientational averaging that shows the coincidence of the Voigt and Reuss bounds on the overall moduli. (C) 1999 American Institute of Physics. [S0021-8979(99)03317-4]. C1 Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Li, JY (reprint author), Univ Calif San Diego, Ctr Excellence Adv Mat, San Diego, CA 92103 USA. RI Li, Jiangyu/B-3191-2008; OI Li, Jiangyu/0000-0003-0533-1397; DUNN, MARTIN/0000-0002-4531-9176 NR 16 TC 13 Z9 14 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1999 VL 86 IS 8 BP 4626 EP 4634 DI 10.1063/1.371413 PG 9 WC Physics, Applied SC Physics GA 240TB UT WOS:000082840300085 ER PT J AU Steiner, B van den Berg, L Laor, U AF Steiner, B van den Berg, L Laor, U TI Enhancement of mercuric iodide detector performance through increases in wafer uniformity by purification and crystal growth in microgravity SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID X-RAY-DETECTORS; DIFFRACTION IMAGING TOPOGRAPHY; MINIATURIZED PROCESSING ELECTRONICS; ALPHA-HGI2 SINGLE-CRYSTALS; SYNCHROTRON RADIATION; TRANSMISSION TOPOGRAPHY; TEMPERATURE OSCILLATION; ARRAY DETECTORS; VAPOR GROWTH; SPACE AB Wafers from mercuric iodide crystals grown in microgravity on two occasions have previously been found to be characterized by a higher hole mobility-lifetime product, which enables energy dispersive radiation detectors with superior resolution. In the present work, we have identified the specific structural modifications that are responsible for this enhanced performance. As a result of this study, the performance of terrestrial wafers also has been improved but not yet to the level of wafers grown in microgravity. High resolution synchrotron x-ray diffraction images of a series of wafers, including those grown both in microgravity and on the ground, reveal two principal types of structural changes that are interrelated. One of these, arrays of inclusions, affects performance far more strongly than the other, variation in lattice orientation. Inclusions can be formed either from residual impurities or in response to deviations from ideal stoichiometry. The formation of both types is facilitated by gravity-driven convection during growth. As the level of inclusions is reduced, through growth from material of higher purity, through the achievement of balanced stoichiometry, or by suppression of convection mixing during crystal growth, the hole mobility-lifetime product is enhanced in spite of an accompanying decreased uniformity in lattice orientation. Sixfold enhancement in the performance of x- and gamma-ray detectors has been accomplished to date. Further augmentation in performance appears likely. (C) 1999 American Institute of Physics. [S0021-8979(99)05720-5]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Constellat Technol Corp, Largo, FL 33777 USA. EG&G Energy Measurements, Goleta, CA USA. RP Steiner, B (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 32 TC 15 Z9 15 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1999 VL 86 IS 8 BP 4677 EP 4687 DI 10.1063/1.371420 PG 11 WC Physics, Applied SC Physics GA 240TB UT WOS:000082840300092 ER PT J AU Fair, JR Nesbitt, DJ AF Fair, JR Nesbitt, DJ TI Dynamics of collisional alignment in supersonic expansions: Trajectory studies of He+CO, O-2, and CO2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID 2-PHOTON NONRESONANT EXCITATION; DIFFERENTIAL CROSS-SECTIONS; POTENTIAL-ENERGY SURFACE; ASYMMETRIC-TOP MOLECULES; SINGLE-PHOTON EXCITATION; INTENSE LASER FIELDS; PENDULAR STATES; ROTATIONAL ALIGNMENT; REACTIVE SCATTERING; ORIENTED MOLECULES AB Classical trajectory calculations have been performed on experimentally determined intermolecular potentials for He-O-2, He-CO, and He-CO2 in order to simulate the collisional formation of rotationally aligned molecular distributions in a supersonic expansion. These calculations verify that multiple collisions between the light "diluent" gas and heavier "seed" rotor molecules result in a distribution of rotor molecules with negative alignment (a(2) < 0), i.e., a preference for j perpendicular to the expansion axis. These rotational alignment effects are found to be robustly insensitive to collision energy and qualitatively similar for all three collision systems, thereby providing a useful basis for comparison with experimental studies. The asymptotic alignment is observed to depend strongly on the angular momentum, increasing monotonically with j. When analyzed on a collision-by-collision basis, this j dependence can be traced to gyroscopic stability, i.e., higher j states are classically more resistant to the collisional loss of alignment. In addition, collisional formation of the alignment is found to reflect comparable contributions from both elastic (m(j)-changing) and inelastic (j-changing) collisions. Finally, the calculations indicate that molecules with j aligned parallel to the expansion axis are correlated with faster average velocities than molecules with j perpendicular to the axis, which is consistent with the He+CO experimental studies of Harich and Wodtke [J. Chem. Phys. 107, 5983 (1997)], as well as the He+N-2(+) drift tube studies of Anthony [J. Chem. Phys. 106, 5413 (1997)]. (C) 1999 American Institute of Physics. [S0021-9606(99)02438-1]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Fair, JR (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 83 TC 21 Z9 21 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 1999 VL 111 IS 15 BP 6821 EP 6833 DI 10.1063/1.479975 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244LB UT WOS:000083051600018 ER PT J AU Yaliraki, SN Roitberg, AE Gonzalez, C Mujica, V Ratner, MA AF Yaliraki, SN Roitberg, AE Gonzalez, C Mujica, V Ratner, MA TI The injecting energy at molecule/metal interfaces: Implications for conductance of molecular junctions from an ab initio molecular description SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; SELF-ASSEMBLED MONOLAYERS; TEMPORARY ANION STATES; CURRENT-VOLTAGE CHARACTERISTICS; ELECTRON-TRANSFER; CARBON NANOTUBES; COULOMB-BLOCKADE; WIRES; TRANSPORT; CONDUCTIVITY AB To study the electronic transport of molecular wire circuits, we present a time-independent scattering formalism which includes an ab initio description of the molecular electronic structure. This allows us to obtain the molecule-metal coupling description at the same level of theory. The conductance of junction alpha, alpha(') xylyl dithiol and benzene-1,4-dithiol between gold electrodes is obtained and compared with available experimental data. The conductance depends dramatically on the relative position of the Fermi energy of the metal with respect to the molecular levels. We obtain an estimate for the injecting energy of the electron onto the molecule by varying the distance between the molecule and the attached gold clusters. Contrary to the standard assumption, we find that the injecting energy lies close to the molecular highest occupied molecular orbital, rather than in the middle of the gap; it is just the work function of the bulk metal. Finally, the adequacy of the widely used extended Huckel method for conductance calculations is discussed. (C) 1999 American Institute of Physics. [S0021-9606(99)70939-6]. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Cent Univ Venezuela, Caracas 1020A, Venezuela. RP Yaliraki, SN (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI Roitberg, Adrian/A-2378-2009 NR 61 TC 260 Z9 266 U1 1 U2 20 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 1999 VL 111 IS 15 BP 6997 EP 7002 DI 10.1063/1.480096 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244LB UT WOS:000083051600038 ER PT J AU Dudowicz, J Freed, KF Douglas, JF AF Dudowicz, J Freed, KF Douglas, JF TI Lattice model of living polymerization. I. Basic thermodynamic properties SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID SUPERFLUID LAMBDA-TRANSITION; LIQUID SULFUR SOLUTIONS; A-NEMATIC TRANSITION; EQUILIBRIUM POLYMERIZATION; MONTE-CARLO; TRICRITICAL POINTS; PHASE-TRANSITIONS; GAUGE THEORIES; CLUSTER THEORY; HEAT-CAPACITY AB A Flory-Huggins type lattice model of living polymerization is formulated, incorporating chain stiffness, variable initiator concentration r, and a polymer-solvent interaction chi. Basic equilibrium properties [average chain length L, average fraction of associated monomers Phi, specific heat C-P, entropy S, polymerization temperature T-p, and the chain length distribution p(N)] are calculated within mean-field theory. Our illustrative calculations are restricted to systems that polymerize upon cooling [e.g., poly(alpha-methylstyrene)], but the formalism also applies to polymerization upon heating (e.g., sulfur, actin). Emphasis is given to living polymer solutions having a finite r in order to compare theory with recent experiments by Greer and co-workers, whereas previous studies primarily focused on the r --> 0(+) limit where the polymerization transition has been described as a second order phase transition. We find qualitative changes in the properties of living polymer solutions for nonzero r: (1) L becomes independent of initial monomer composition phi(m)(0) and temperature T at low temperatures [L(T much less than T-p)similar to 2/r], instead of growing without bound; (2) the exponent describing the dependence of L on phi(m)(0) changes by a factor of 2 from the r --> 0(+) value at higher temperatures (T greater than or equal to T-p); (3) the order parametertype variable Phi develops a long tail with an inflection point at T-p; (4) the specific heat maximum C-P(*) at T-p becomes significantly diminished and the temperature range of the polymer transition becomes broad even for small r [r similar to O(10(-3))]. Moreover, there are three characteristic temperatures for r > 0 rather than one for r --> 0: a "crossover temperature" T-x demarking the onset of polymerization, an r-dependent polymerization temperature T-p defined by the maximum in C-P (or equivalently, the inflection point of Phi), and a "saturation temperature" T-s at which the entropy S of the living polymer solution saturates to a low temperature value as in glass-forming liquids. A measure of the "strength" of the polymerization transition is introduced to quantify the "rounding" of the phase transition due to nonzero r. Many properties of living polymer solutions should be generally representative of associating polymer systems (thermally reversible gels, colloidal gels, micelles), and we compare our results to other systems that self-assemble at equilibrium. (C) 1999 American Institute of Physics. [S0021-9606(99)50539-4]. C1 Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Univ Chicago, James Franck Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 101 TC 96 Z9 97 U1 2 U2 23 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 15 PY 1999 VL 111 IS 15 BP 7116 EP 7130 DI 10.1063/1.480004 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244LB UT WOS:000083051600052 ER PT J AU Manderson, JP Phelan, BA Bejda, AJ Stehlik, LL Stoner, AW AF Manderson, JP Phelan, BA Bejda, AJ Stehlik, LL Stoner, AW TI Predation by striped searobin (Prionotus evolans, Triglidae) on young-of-the-year winter flounder (Pseudopleuronectes americanus, Walbaum): examining prey size selection and prey choice using field observations and laboratory experiments SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE predator-prey; prey choice; size selection; trigilid; flatfish predator ID NEW-YORK BIGHT; PLEURONECTES-PLATESSA; SCOPHTHALMUS-MAXIMUS; SEDIMENT PREFERENCE; 0-GROUP FLATFISHES; JUVENILE PLAICE; SHRIMP; RECRUITMENT; SUBSTRATUM; SETTLEMENT AB Laboratory experiments and field observations in shallow water habitats in the Navesink River/Sandy Hook Bay estuarine system (NSHES), New Jersey, USA, were used to examine the predator-prey relationship between the striped searobin (Prionotus evolans: Linnaeus) and young-of-the-year (YOY) winter flounder (Pseudopleuronectes americanus: Walbaum). Striped sea robins (121-367 mm total length [TL]) were present in Sandy Hook Bay but absent from the Navesink River in biweekly gillnet surveys conducted from May through October, 1998. However, juvenile winter flounder were present throughout the estuary during periodic beam trawl surveys. Although mysids and sand shrimp (Crangon septemspinosa, Say: 10-49 mm TL) were the numerically predominant prey of searobins, winter flounder (15-57 mm TL) accounted for an average of 17% (+/-3) of prey by weight and were found in the diets of 69% of predators collected in June. In the laboratory, searobins (212-319 mm TL) presented with a range of winter flounder sizes (30-114 mm TL) selected prey < 70 mm TL (24% of predator TL) and maximum prey size appeared to be constrained by predator esophageal width. When winter flounder (40-60 mm TL) and sand shrimp (30-50 mm TL) were offered at different densities to searobins, the predators fed opportunistically, consuming the prey in proportions similar to initial relative abundances. Laboratory observations showed that searobins rely on modified pectoral finrays to detect, flush, and occasionally excavate buried winter flounder. Our field and laboratory observations indicate that striped searobins consume large numbers of winter flounder in vulnerable size classes (15-70 mm TL) in habitats where the two species co-occur. Patterns in the distribution of the two species in the NSHES suggest that predation probably varies spatially in the estuary, with flounder more at risk in nurseries in Sandy Hook Bay than in the Navesink River, which may serve as a spatial refuge for winter flounder from searobin predation during some years. (C) 1999 Elsevier Science B.V. All rights reserved. C1 James J Howard Marine Sci Lab, Behav Ecol Branch NOAA, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. RP Manderson, JP (reprint author), James J Howard Marine Sci Lab, Behav Ecol Branch NOAA, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. EM john.manderson@noaa.gov NR 51 TC 37 Z9 37 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD OCT 15 PY 1999 VL 242 IS 2 BP 211 EP 231 DI 10.1016/S0022-0981(99)00105-7 PG 21 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 243MP UT WOS:000083002100004 ER PT J AU Dherin, C Radicella, JP Dizdaroglu, M Boiteux, S AF Dherin, C Radicella, JP Dizdaroglu, M Boiteux, S TI Excision of oxidatively damaged DNA bases by the human alpha-hOgg1 protein and the polymorphic alpha-hOgg1(Ser326Cys) protein which is frequently found in human populations SO NUCLEIC ACIDS RESEARCH LA English DT Article ID GENERATED FREE-RADICALS; COLI FPG PROTEIN; SACCHAROMYCES-CEREVISIAE; ESCHERICHIA-COLI; SUBSTRATE-SPECIFICITY; OGG1 GENE; IONIZING-RADIATION; PURINE LESIONS; HUMAN HOMOLOG; REPAIR AB We have investigated the substrate specificity of the major nuclear form of the human Ogg1 protein, referred as alpha-hOgg1, for excision of damaged bases from DNA exposed to gamma-irradiation, Excision products were identified and quantified using gas chromatography/isotope dilution mass spectrometry (GC/IDMS), The GST-alpha-hOgg1 protein used in this study is a fusion of alpha-hOgg1 to the C-terminus of the GST protein. The results show that GST-alpha-hOgg1 protein excises 8-hydroxyguanine (8-OH-Gua) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua) from DNA exposed to gamma-irradiation in a solution saturated with N2O or air, Fourteen other lesions, including oxidised purines and pyrimidines, were not excised from these substrates, Catalytic constants were measured for the excision of 8-OH-Gua and FapyGua from DNA gamma-irradiated under N2O. The k(cat)/K-m values for excision of 8-OH-Gua and FapyGua were 4.47 x 10(-5) and 8.97 x 10(-5) (min(-1) nM(-1)), respectively. The substrate specificity and the catalytic parameters of the wild-type GST-alpha-hOgg1 protein were compared to that of a polymorphic form of alpha-hOgg1 harbouring a Ser-->Cys mutation at codon 326, In the Japanese population, 47.6% of individuals possess both alleles coding for the wild-type alpha-hOgg1-Ser(326) and mutant alpha-hOgg1-Cys(326) proteins. The GST-alpha-hOgg1-Cys(326) protein was purified and its substrate specificity was determined by GC/IDMS analysis. The results show that the GST-alpha-hOgg1-Cys(326) protein efficiently excises 8-OH-Gua and FapyGua from gamma-irradiated DNA, The k(cat)/K-m values for excision of 8-OH-Gua and FapyGua were 2.82 x 10(-5) and 4.43 x 10(-5) (min(-1) nM(-1)), respectively. Furthermore, we compared the capacity of these two forms of alpha-hOgg1 to act on substrates containing 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (Me-FapyGua). The k(cat)/K-m values for excision of Me-FapyGua were 278 x 10(-5) and 319 x 10(-5) (min(-1) nM(-1)), respectively. Cleavage of 34mer oligodeoxyribonucleotides containing 8-OH-Gua, 8-hydroxyadenine or an apurinic/apyrimidinic site paired with a cytosine was also investigated. The results show that both GST-alpha-hOgg1-Ser(326) and GST-alpha-hOgg1-Cys(326) catalyse the various cleavage reactions at very similar rates. Furthermore, both proteins efficiently complement the mutator phenotype of the fpg mutY mutant of Escherichia coli. C1 CEA, UMR217 CNRS, DRR, DSV, F-92265 Fontenay Aux Roses, France. NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Boiteux, S (reprint author), CEA, UMR217 CNRS, DRR, DSV, 60 Rue Gen Leclerc,BP6, F-92265 Fontenay Aux Roses, France. NR 49 TC 203 Z9 211 U1 0 U2 9 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 OCT 15 PY 1999 VL 27 IS 20 BP 4001 EP 4007 DI 10.1093/nar/27.20.4001 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 247BU UT WOS:000083201400007 PM 10497264 ER PT J AU Yildirim, T Neumann, DA Trevino, SF Fischer, JE AF Yildirim, T Neumann, DA Trevino, SF Fischer, JE TI Neutron scattering study of Na2C60 in the pressure-temperature plane SO PHYSICAL REVIEW B LA English DT Article ID FULLERIDE SUPERCONDUCTORS; PHASE; C-60; C60; DYNAMICS; LATTICE; POLYMER AB Na2C60 is the only known fulleride with divalent C-60 and orientational order (Pa (3) over bar symmetry). We investigated the phase behavior of Na2C60 for 0 < P < 4 kbar and 100 K < T < 325 K using neutron scattering. Diffraction data indicate no change from Pa (3) over bar with applied pressure up to 4 kbar at temperatures below 200 K. in this phase, Na2C60 is 37% stiffer than pure C-60 and 41% softer than K3C60 However, for T > 200 K and P > 1 kbar, the structure is transformed into a low-symmetry distorted phase. Here the peaks at low Q are significantly broadened while the high Q peaks are almost completely smeared out. This transformation is reversible; releasing pressure above 200 K recovers the cubic Pa (3) over bar structure. [S0163-1829(99)11539-X]. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. USA, Res Lab, Aberdeen Proving Ground, MD 20783 USA. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. RP Yildirim, T (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI yildirim, taner/A-1290-2009 NR 19 TC 4 Z9 4 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 OCT 15 PY 1999 VL 60 IS 15 BP 10707 EP 10710 DI 10.1103/PhysRevB.60.10707 PG 4 WC Physics, Condensed Matter SC Physics GA 251CT UT WOS:000083427600038 ER PT J AU Remley, KA Weisshaar, A Anderson, HR AF Remley, KA Weisshaar, A Anderson, HR TI Improved diffraction coefficients for lossy dielectric wedges SO ELECTRONICS LETTERS LA English DT Article ID EDGE AB Improved site-specific prediction of the diffracted fields from lossy dielectric obstacles is presented. A commonly used set of diffraction coefficients are redefined in a more physical way. The theoretical basis for the improvement is presented and validation is given by comparison to full-wave simulation results. C1 Oregon State Univ, Dept Elect & Comp Engn, Corvallis, OR 97331 USA. EDX Engineerind Inc, Eugene, OR 97440 USA. RP Remley, KA (reprint author), Natl Inst Stand & Technol, RF Elect Grp, Boulder, CO 80309 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 14 PY 1999 VL 35 IS 21 BP 1826 EP 1827 DI 10.1049/el:19991228 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 251GM UT WOS:000083436900028 ER PT J AU Schwartz, RL Davico, GE Ramond, TM Lineberger, WC AF Schwartz, RL Davico, GE Ramond, TM Lineberger, WC TI Singlet-triplet splittings in CX2 (X = F, Cl, Br, I) dihalocarbenes via negative ion photoelectron spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID LASER-INDUCED FLUORESCENCE; FREE-JET EXPANSION; GAS-PHASE; SUBSTITUTED CARBENES; EXCITATION SPECTRUM; ELECTRONIC-SPECTRUM; DICHLOROCARBENE CCL2; ATOMIC OXYGEN; CF2; HALOCARBENES AB The 364 nm negative ion photoelectron spectra of CF2-, CCl2-, CBr2-, and CI2- exhibit transitions to two different electronic states, the (1)A(1) and B-3(1). The CF2- spectrum exhibits well-resolved transitions to both electronic states. In the cases of CCl2-, CBr2-, and CI2-, the spectra exhibit extended, partially resolved vibrational progressions and the two states are overlapped, making a direct determination of the origin transition energy not possible. The overlapped spectra show that the singlet-triplet splittings in the heavier halocarbenes are much smaller than for CF2-. The results of ab initio calculations have been used to generate Franck-Condon simulations of the spectra; which aid in the determination of the band origins. The (1)A(1) state is found to be the lower state for CF2, CCl2, and CBr2 and the electron affinities have been determined to be 0.180 +/- 0.020, 1.59 +/- 0.07, and 1.88 +/- 0.07 eV, respectively. For CI2, the triplet state is apparently the lower lying state with an electron affinity of 2.09 +/- 0.07 eV. The singlet-triplet splitting energy has been determined to be 54 +/- 3, 3 +/- 3, 2 +/- 3, -1 +/- 3 kcal/mol for CF2, CCl2, CBr2, and CI2, respectively. In addition, the bending and symmetric stretching vibrational frequencies have been determined for either one or both states. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Lineberger, WC (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Campus Box 440, Boulder, CO 80309 USA. NR 57 TC 107 Z9 111 U1 1 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 OCT 14 PY 1999 VL 103 IS 41 BP 8213 EP 8221 DI 10.1021/jp992214c PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 250EJ UT WOS:000083375800013 ER PT J AU Willoughby, HE AF Willoughby, HE TI Hurricane heat engines SO NATURE LA English DT Editorial Material C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Willoughby, HE (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. NR 5 TC 6 Z9 6 U1 2 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 14 PY 1999 VL 401 IS 6754 BP 649 EP 650 DI 10.1038/44287 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 247EJ UT WOS:000083207400032 ER PT J AU Carpenter, TM Sperfslage, JA Georgakakos, KP Sweeney, T Fread, DL AF Carpenter, TM Sperfslage, JA Georgakakos, KP Sweeney, T Fread, DL TI National threshold runoff estimation utilizing GIS in support of operational flash flood warning systems SO JOURNAL OF HYDROLOGY LA English DT Article DE hydrology; flash floods; forecasting; distributed modeling; geographic information systems; radar AB Threshold runoff is the amount of excess rainfall accumulated during a given time period over a basin that is just enough to cause flooding at the outlet of the draining stream. Threshold runoff estimates are indicators of maximal sustainable surface runoff for a given catchment, and are thus an essential component of flash flood warning systems. Used in conjunction with soil moisture accounting models and areal rainfall data, they form the basis of the US National Weather Service (NWS) flash flood watch/warning program. As part of their modernization and enhancement effort, the NWS determined that improved flash flood guidance and thus improved threshold runoff estimation is needed across the United States, with spatial resolution commensurate to that afforded by the WSR-88D (NEXRAD) radars. In this work, Geographic Information Systems (GIS) and digital terrain elevation databases have been used to develop a national system for determining threshold runoff. Estimates of threshold runoff an presented for several locations in the United States, including large portions of the states of Iowa, Oklahoma, and California, and using several options in computing threshold runoff. Analysis of the results indicates the importance of channel geometry in flash flood applications. Larger threshold runoff estimates were computed in Oklahoma (average value of 34 mm) than in Iowa (14 mm) or California (9.5 mm). Comparisons of the threshold runoff estimates produced by the GIS procedure with those based on manually computed unit hydrographs for the selected catchments are shown as a preliminary measure of the accuracy of the procedure. Differences of up to about 15 mm for hourly rainfall durations were obtained for basins larger than 50 km(2). (C) 1999 Elsevier Science B.V. All rights reserved. C1 Hydrol Res Ctr, San Diego, CA 92130 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NOAA, Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. RP Georgakakos, KP (reprint author), Hydrol Res Ctr, 12780 High Bluff Dr,Suite 250, San Diego, CA 92130 USA. NR 31 TC 94 Z9 101 U1 5 U2 33 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD OCT 12 PY 1999 VL 224 IS 1-2 BP 21 EP 44 DI 10.1016/S0022-1694(99)00115-8 PG 24 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 252TT UT WOS:000083518900002 ER PT J AU Pipino, ACR AF Pipino, ACR TI Ultrasensitive surface spectroscopy with a miniature optical resonator SO PHYSICAL REVIEW LETTERS LA English DT Article ID RING-DOWN SPECTROSCOPY; ABSORPTION-MEASUREMENTS; CAVITY; ORDER AB The number density and orientation of molecules at the surface of a total-internal-reflection-ring minicavity are probed with extremely high sensitivity in a novel realization of the cavity ring-down optical absorption experiment. The modes of the ultralow-loss cavity, which are excited by photon tunneling, have long lifetimes that are sensitive to the presence of absorbing species in the evanescent field near a cavity facet. The total-internal-reflection-ring cavity extends cavity ring-down spectroscopy to surfaces and condensed matter, permitting a wide range of novel fundamental studies and applications. Routine single molecule detection may ultimately be feasible. C1 NIST, Chem Sci & Technol Lab, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Pipino, ACR (reprint author), NIST, Chem Sci & Technol Lab, Proc Measurements Div, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 19 TC 69 Z9 70 U1 1 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 11 PY 1999 VL 83 IS 15 BP 3093 EP 3096 DI 10.1103/PhysRevLett.83.3093 PG 4 WC Physics, Multidisciplinary SC Physics GA 244FP UT WOS:000083041400057 ER PT J AU Atkinson, DB Hudgens, JW AF Atkinson, DB Hudgens, JW TI Chlorination chemistry. I. Rate coefficients, reaction mechanisms, and spectra of the chlorine and bromine adducts of propargyl halides SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTIPHOTON IONIZATION; ELECTRONIC-SPECTRUM; PRESSURE-DEPENDENCE; RADICALS; ALLYL; SPECTROSCOPY; NM; PHOTODISSOCIATION; METHYLACETYLENE; MOLECULES AB Cavity ring-down spectroscopy (CRDS), end-product analysis, and ab initio calculations have determined absorption cross sections, rate coefficients, reaction mechanisms, and thermochemistry relevant to the addition of halogen atoms to propargyl chloride and propargyl bromide. Halogen atoms were produced by laser photolysis, and the addition reaction products were probed at a variable delay by CRDS using a second laser pulse. We report the continuum spectra of C3H3Cl2 (1,2-dichloroallyl), C3H3ClBr (1-chloro-2-bromoallyl), and C3H3Br2 (1,2-dibromoallyl) radicals between 238 and 252 nm and the absorption cross sections, sigma(240)(C3H3Cl2) = (4.20 +/- 1.05) x 10(-17) cm(2) molecule(-1) and sigma(242)(C3H3Br2) = (1.04 +/- 0.31) X 10(-17) cm(2) molecule(-1). When the observed data are fit to complex reaction schemes, the 298 K rate coefficients for formation of 1,2-dihaloallyl radicals at 665 Pa were found to be k(Cl + C3H3Cl) = (1.2 +/- 0.2) x 10(-10) cm(3) molecule(-1) s(-1) and k(Br + C3H3Br) = (2 +/- 1) x 10(-12) cm(3) molecule(-1) s(-1). At 298 K and 665 Pa the self-reaction rate coefficients of these radicals were found to be k(C3H3Cl2 + C3H3Cl2) = (3.4 +/- 0.9) x 10(-11) cm(3) molecule(-1) s(-1) and k(C3H3Br2 + C3H3Br2) = (1.7 +/- 1.1) x 10(-11) cm(3) molecule(-1) s(-1). The listed uncertainties are twice the standard deviation of individual determinations, and those for rate coefficients include the uncertainty of the appropriate absorption cross section. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Atkinson, DB (reprint author), Portland State Univ, Dept Chem, Portland, OR 97207 USA. NR 51 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 OCT 7 PY 1999 VL 103 IS 40 BP 7978 EP 7989 DI 10.1021/jp991076o PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 246EJ UT WOS:000083151200007 ER PT J AU Holcomb, CD Outcalt, SL AF Holcomb, CD Outcalt, SL TI Near-saturation (P, rho,T) and vapor-pressure measurements of NH3, and liquid-phase isothermal (P,rho,T) and bubble-point-pressure measurements of NH3+H(2)Omixtures SO FLUID PHASE EQUILIBRIA LA English DT Article DE ammonia; ammonia plus water; vapor pressure; bubble-point pressure; pressure-density-temperature ID THERMODYNAMIC PROPERTIES; TEMPERATURES; AMMONIA; (VAPOR; SYSTEM AB Near-saturation pressure, density, and temperature (P,rho,T) and vapor-pressure measurements for NH, are reported over a temperature range from 279 to 392 K. Liquid-phase isothermal (P,rho,T) and bubble-point-pressure measurements for two standard mixtures of NH3 + H2O (x(NH3) = 0.8360 and 0.9057 mole fraction) are reported over a temperature range from 280 to 379 K and at pressures to 7.7 MPa. These data are compared to literature data and correlations and agree within +/-3% for bubble-point pressures, +/-0.005 g/cm(3) for liquid densities, and +/-0.0011 g/cm(3) for vapor densities. A consistent data set for equation-of-state optimization at high concentrations of NH3 is proposed. (C) 1999 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, US Dept Commerce, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Holcomb, CD (reprint author), Natl Inst Stand & Technol, US Dept Commerce, Phys & Chem Properties Div, 325 Broadway,MS 838-07, Boulder, CO 80303 USA. NR 21 TC 11 Z9 11 U1 1 U2 6 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 OCT 6 PY 1999 VL 164 IS 1 BP 97 EP 106 DI 10.1016/S0378-3812(99)00242-3 PG 10 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 243TM UT WOS:000083013400006 ER PT J AU Hubbard, JB AF Hubbard, JB TI The role of conformational energetic disorder in the catalytic activity of immobilized enzymes SO BIOPHYSICAL CHEMISTRY LA English DT Article DE immobilized enzymes; disorder; catalytic activity ID MODEL AB We analyze cooperative behavior in a system of immobilized enzymes which incorporates the notion of heterogeneity or disorder in the interactions. in addition to equilibrium phase changes, this system exhibits vitrification or glass-like transitions in which the overall catalytic activity freezes into one of many possible states. It is shown that these long-lived metastable phases can be produced by a combination of disorder, systematic surface and intermolecular interactions, and chemical association effects such as ligand binding. Biophysical consequences of this frozen state include greatly diminished sensitivity of enzymatic activity to thermal and chemical perturbations. This effect coincides with the appearance of a multitude of possible macroscopic catalytic states rather than a single equilibrium state. Our analysis also suggests that high surface coverages will tend to be catalytically inactive if they are fully equilibrated; rather, high activity with high surface coverage is more likely to be associated with vitrified states of surface immobilization and deep or abrupt chemical quenches. (C) 1999 Elsevier Science B.V. AU rights reserved. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Hubbard, JB (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD OCT 4 PY 1999 VL 81 IS 2 BP 81 EP 92 DI 10.1016/S0301-4622(99)00071-X PG 12 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA 240CX UT WOS:000082809100001 PM 17030331 ER EF