FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Rodriguez, H Akman, SA AF Rodriguez, H Akman, SA BE Blass, JP McDowell, FH TI Measurement of oxidative DNA damage in the human p53 and PGK1 gene at nucleotide resolution SO OXIDATIVE/ENERGY METABOLISM IN NEURODEGENERATIVE DISORDERS SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Oxidative/Energy Metabolism in Neuridegenerative Disorders CY MAR 19-22, 1999 CL NEW YORK, NEW YORK SP New York Acad Sci, Winifred Masterson Burke Med Res Inst Inc, NIA, NIH, MitoKor, Amer Fed Aging Res, Warner Lambert Co, Parke Davis Pharmaceut Res ID HYDROGEN; MUTATION; SPECTRUM; PLASMID C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Wake Forest Univ, Dept Canc Biol, Ctr Comprehens Canc, Winston Salem, NC 27157 USA. RP Rodriguez, H (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr,Stop 8311, Gaithersburg, MD 20899 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-209-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1999 VL 893 BP 382 EP 385 DI 10.1111/j.1749-6632.1999.tb07861.x PG 4 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Multidisciplinary Sciences; Neurosciences; Ornithology SC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Science & Technology - Other Topics; Neurosciences & Neurology; Zoology GA BP50E UT WOS:000085330600050 PM 10672273 ER PT B AU Wavering, AJ AF Wavering, AJ BE Boer, CR MolinariTosatti, L Smith, KS TI Parallel kinematic machine research at NIST: Past, present, and future SO PARALLEL KINEMATIC MACHINES: THEORETICAL ASPECTS AND INDUSTRIAL REQUIREMENTS SE ADVANCED MANUFACTURING SERIES LA English DT Proceedings Paper CT 1st European-American Forum on Parallel Kinematic Machines CY AUG 31-SEP 01, 1998 CL LEONARDO DAVINCI NATL MUSEUM SCI & TECHNOL, MILAN, ITALY SP CNR, Inst Ind Technologies & Automat, European Commiss, US Natl Sci Fdn, Italian Minist Univ & Sci & Technol Res HO LEONARDO DAVINCI NATL MUSEUM SCI & TECHNOL AB Unchained from the confines of controller limitations, the industrial application of parallel kinematic machines in manufacturing is beginning to emerge. The launch of commercially available hexapod machine tools at the 1994 International Manufacturing Technology Show in Chicago represented the first radical departure in machine tool design since the introduction of numerical controls. The parallel actuator technology promises to offer manufacturers a number of advantages relative to conventional machine tools, such as a higher stiffness-to-mass ratio, higher speeds, higher accuracy, reduced installation requirements, and mechanical simplicity. Several machine tool makers in the U.S. and around the world are pursuing parallel actuator technology, while their prospective customers - manufacturers - are beginning to contemplate what the novel multi-axis machining technology might mean for their operations. As part of the Manufacturing Engineering Laboratory's National Advanced Manufacturing Testbed (NAMT), MST researchers and collaborators from industry and universities are studying the new tools' unique capabilities. The work includes extensive tests on an octahedral hexapod machine tool that was installed at NIST in May 1995. Research areas include machine metrology, performance characterization test methods and standards, performance enhancement methods, simulation and remote experimentation tools, and open architecture controller interfaces. This paper will give an overview of history and current status of research in parallel kinematic machines at NIST. The merits and key challenges of parallel kinematic machine tools will also be addressed, and directions for future research will be identified. C1 NIST, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Wavering, AJ (reprint author), NIST, Intelligent Syst Div, Gaithersburg, MD 20899 USA. NR 16 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL RD FARNCOMBE, GODALMING GU7 1NH, SURREY, ENGLAND BN 1-85233-613-7 J9 ADV MANUF S PY 1999 BP 17 EP 31 PG 15 WC Engineering, Manufacturing; Mechanics SC Engineering; Mechanics GA BQ35L UT WOS:000088113900002 ER PT B AU Soons, JA AF Soons, JA BE Boer, CR MolinariTosatti, L Smith, KS TI On the geometric and thermal errors of a hexapod machine tool SO PARALLEL KINEMATIC MACHINES: THEORETICAL ASPECTS AND INDUSTRIAL REQUIREMENTS SE ADVANCED MANUFACTURING SERIES LA English DT Proceedings Paper CT 1st European-American Forum on Parallel Kinematic Machines CY AUG 31-SEP 01, 1998 CL LEONARDO DAVINCI NATL MUSEUM SCI & TECHNOL, MILAN, ITALY SP CNR, Inst Ind Technologies & Automat, European Commiss, US Natl Sci Fdn, Italian Minist Univ & Sci & Technol Res HO LEONARDO DAVINCI NATL MUSEUM SCI & TECHNOL AB This paper describes the measurement and analysis of the quasi-static errors of a prototype hexapod milling machine located at the National Institute of Standards and Technology (NIST). Emphasis is placed on a) identification of the most important parametric errors and their potential impact on performance, b) description of the techniques used to measure and estimate the parametric errors, and c) application of various concepts to model the geometric and thermal errors of the hexapod. C1 NIST, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. RP NIST, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. NR 10 TC 14 Z9 17 U1 1 U2 3 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL RD FARNCOMBE, GODALMING GU7 1NH, SURREY, ENGLAND BN 1-85233-613-7 J9 ADV MANUF S PY 1999 BP 151 EP 169 PG 19 WC Engineering, Manufacturing; Mechanics SC Engineering; Mechanics GA BQ35L UT WOS:000088113900010 ER PT J AU Graczyk, TK Fayer, R Conn, DB Lewis, EJ AF Graczyk, TK Fayer, R Conn, DB Lewis, EJ TI Evaluation of the recovery of waterborne Giardia cysts by freshwater clams and cyst detection in clam tissue SO PARASITOLOGY RESEARCH LA English DT Article ID FILTER DISSOLUTION METHOD; CORBICULA-FLUMINEA; CRYPTOSPORIDIUM; PREVALENCE; OOCYSTS; SAMPLES; BEAVER; MODEL AB The Asian freshwater clam, Corbicula fluminea, inhabits environments recognized to be contaminated with waterborne Giardia cysts. Sixty-four tissue samples of Giardia-free clams were spiked with various numbers of Giardia duodenalis cysts within the range of 50-700 cysts. Regression analysis showed that paired numbers of spiked (x) versus recovered (y) cysts regressed significantly (P < 0.01) according to the equation y = 42.57 + 1.81x- (+/- 64.3). The cyst detection threshold was 43 cysts/clam, the coefficient of determination was 77%, and the overall sensitivity of cyst detection was 42.9%. All 20 values of cyst numbers in clam tissue samples that were processed blind were located within the 95% prediction limits of the linear regression equation. The cyst retention rate of 160 clams kept in an aquarium with 38 1 of water spiked with 1.00 x 10(5) G. duodenalis cysts was approximately 1.3 x 10(3) cysts/clam. No waterborne cysts were detected by the membrane filtration method 90 min after spiking the aquarium water. G. duodenalis cysts were detected in clam tissue up to 3 weeks post-exposure. Filtration of water by clams substantially depleted the aquarium water of its particulate matter. The sampling program demonstrated that the population of 160 clams examined during the study could be accurately assessed for exposure to waterborne Giardia cysts by random sampling of 86 (54%) clams. The results indicate that C. fluminea clams can be used for biological monitoring of contamination with Giardia. C1 Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, Baltimore, MD 21205 USA. USDA ARS, Livestock & Poultry Sci Inst, Immunity & Dis Prevent Lab, Beltsville, MD 20705 USA. Berry Coll, Sch Math & Nat Sci, Mt Berry, GA 30149 USA. US Dept Commerce, NOAA, Natl Marine Fisheries Serv, Cooperat Oxford Lab, Oxford, MD 21654 USA. RP Graczyk, TK (reprint author), Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, 615 N Wolfe St, Baltimore, MD 21205 USA. OI Conn, David Bruce/0000-0003-0198-0234 NR 21 TC 14 Z9 14 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0044-3255 J9 PARASITOL RES JI Parasitol. Res. PD JAN PY 1999 VL 85 IS 1 BP 30 EP 34 DI 10.1007/s004360050503 PG 5 WC Parasitology SC Parasitology GA 144GP UT WOS:000077306200006 PM 9950225 ER PT J AU Chow, LC Markovic, M Takagi, S AF Chow, LC Markovic, M Takagi, S TI Formation of hydroxyapatite in cement systems: Effects of phosphate SO PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS LA English DT Article; Proceedings Paper CT XIVth International Conference on Phosphorus Chemistry (XIVth-ICPC) CY JUL 12-17, 1998 CL CINCINNATI, OH SP Cincinnati Local ACS Sect DE calcium phosphate cements; diametral tensile strength; hardening time; hydroxyapatite; phosphate ions AB The rate of hydroxyapatite (HA) formation in several calcium phosphate cement (CPC) systems was promoted when a phosphate solution instead of water was used as the cement liquid. The accelerated HA formation reduced the hardening time (HT) of the cements. In the cement system consisting of tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA), and distilled water, the presence of small TTCP particles (median diameter of 2.7 mu m) reduced phosphate concentration in liquid phase, inhibited HA formation, and prolonged HT. C1 NIST, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. RP Chow, LC (reprint author), NIST, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1042-6507 EI 1563-5325 J9 PHOSPHORUS SULFUR JI Phosphorus Sulfur Silicon Relat. Elem. PY 1999 VL 144 BP 129 EP 132 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 249EW UT WOS:000083320800034 ER PT J AU Vetter, RD Kurtzman, A Mori, T AF Vetter, RD Kurtzman, A Mori, T TI Diel cycles of DNA damage and repair in eggs and larvae of northern anchovy, Engraulis mordax, exposed to solar ultraviolet radiation SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID CULTURED FISH CELLS; CYCLOBUTANE PYRIMIDINE DIMER; FLUORESCENT LIGHT; PHOTOREPAIR; SKIN; PREILLUMINATION; FIBROBLASTS; ENHANCEMENT; PHOTOLYASE; INDUCTION AB Damage from UVB radiation (280-320 nm) in the form of cyclobutane pyrimidine dimers (CPD) in DNA and the capacity for their repair were measured in newly spawned eggs and yolk-sac larvae of northern anchovy, Engraulis mordax, exposed to natural diel cycles of sunlight, The CPD were measured by a newly developed chemiluminescent immunoblot assay capable of measuring CPD in samples as small as 50 ng DNA, Eggs and yolk-sac larvae exposed to full irradiance levels died. At lower dose rates, equivalent to deeper more natural locations in the water column, there was a diel cycle of dimer concentration that tracked solar intensity. This diel cycle was due to the interaction of damage and repair processes. Repair of CPD in anchovy eggs and larvae could be attributed to true photodependent repair that could be stopped by moving samples into the dark. The CPD present at sunset remained until the following morning. The diel cycles of damage and repair were maintained over at least 4 days without a long-term upward or downward trend in dimer concentration. This indicates that at the UVB doses used for these experiments, there was no long-term accumulation of CPD nor an induction of increased repair capacity. Unhatched embryos spawned in the dark also exhibited a strong photorepair response, suggesting that photolyase expression was innate and not dependent on previous light exposure. The diel cycle observed here indicates that, at least for northern anchovy, the CPD concentration at the time of sampling is a good indicator of dose rate but a poor indicator of cumulative dose (i.e. late afternoon samples have the highest cumulative dose but relatively low CPD concentrations). The CPD immunoassay described here has the required sensitivity for measuring DNA damage in wild populations of ichthyoplankton exposed to natural sunlight. These results will guide the collection and interpretation of field data on natural levels of CPD in wild larvae collected at different depths and times of the day. C1 SW Fisheries Sci Ctr, Natl Ocean & Atmospher Adm, La Jolla, CA 92038 USA. Nara Med Univ, Radioisotope Res Ctr, Nara, Japan. RP Vetter, RD (reprint author), SW Fisheries Sci Ctr, Natl Ocean & Atmospher Adm, La Jolla, CA 92038 USA. EM rvetter@ucsd.edu NR 27 TC 49 Z9 49 U1 0 U2 1 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JAN PY 1999 VL 69 IS 1 BP 27 EP 33 DI 10.1111/j.1751-1097.1999.tb05302.x PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 158BU UT WOS:000078096800009 ER PT J AU Skanthakumar, S Lynn, JW AF Skanthakumar, S Lynn, JW TI Rare earth magnetic order in RNi2B2C and RNiBC SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Conference on Strongly Correlated Electron Systems (SCES 98) CY JUL 15-18, 1998 CL PARIS, FRANCE SP CNRS, Minist Educ Natl Rech Technol, CEA, Minist Affaires Etrangeres, DGA, Univ Paris-Sud DE magnetic structure; neutron diffraction; magnetic transitions; borocarbides ID NICKEL BORIDE CARBIDES; CRYSTAL-STRUCTURE; SUPERCONDUCTIVITY; SUSCEPTIBILITY; SUPPRESSION; SCATTERING; YBNI2B2C; HONIBC AB A review of neutron diffraction experiments on the magnetic order in the RNi2B2C and RNiBC (R - rare earth) systems is given. The RNi2B2C materials exhibit a R-ide variety of commensurate and incommensurate magnetic structures for different rare earths, along with superconductivity that is coupled to the magnetism. Simple commensurate antiferromagnetic structures are observed for R = Pr (T-N = 4.0 K), Nd (T-N = 4.8 K), Ho (T-N = 8.5 K) and Dy (T-N = 11 K). In addition, HoNi2B2C exhibits a c-axis spiral and an a-axis modulated incommensurate structure above 5 K, while both structures collapse in favor of the commensurate structure at low T. A transversely polarized spin density wave (SDW) type incommensurate structure is observed for Er (T-N = 6.8 K) and Tm (T-N = 1.5 K), while a longitudinally polarized SDW structure is observed for Tb (T-N = 15 K) No magnetic ordering of any type is detected for Y, Ce and Yb. HoNiBC is an antiferromagnet (T-N = 9.8 K), ErNiBC is ferromagnetic (T-C = 4.6 K), while TbNiBC and DyNiBC exhibit both ferromagnetic and antiferromagnetic ordering at 17 K and similar to 12 K, respectively. Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Skanthakumar, S (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM skantha@anl.gov NR 24 TC 22 Z9 24 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JAN PY 1999 VL 259-61 BP 576 EP 581 DI 10.1016/S0921-4526(98)00730-3 PG 6 WC Physics, Condensed Matter SC Physics GA 179FR UT WOS:000079315700248 ER PT J AU Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ O'Brian, TR Rolston, SL Sansonetti, CJ Wen, J Westbrook, N Cheng, CH Eyler, EE AF Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ O'Brian, TR Rolston, SL Sansonetti, CJ Wen, J Westbrook, N Cheng, CH Eyler, EE TI Precision spectroscopy in He as a test of QED SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 6th International Colloquium on Atomic Spect and Oscillator Strengths (ASOS 6) CY AUG 09-13, 1998 CL UNIV VICTORIA, VICTORIA, CANADA SP Herzberg Inst Astrophys, Natl Res Council Canada, Natl Inst Stand & Technol, Univ Victoria, Dept Phys & Astron HO UNIV VICTORIA ID STATE LAMB SHIFT; ENERGY-LEVELS; GROUND-STATE; VARIATIONAL CALCULATIONS; 2-PHOTON SPECTROSCOPY; LASER SPECTROSCOPY; IONIZATION-ENERGY; HYDROGEN 1S-2S; HELIUM; TRANSITIONS AB High-resolution laser-based measurements of energy levels have spurred the development and refinement of quantum electrodynamic calculations. We have extended very-high-resolution laser spectroscopy techniques into the vacuum ultraviolet wavelength region at lambda approximate to 120 nm to determine the Lamb shift in the ground state of He I. The importance of this measurement to high accuracy quantum electrodynamics calculations is discussed. Details of the present measurement and future improvements are presented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. SDL Inc, San Jose, CA 95134 USA. Australian Natl Univ, Canberra, ACT 0200, Australia. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Imperial Coll, London, England. Inst Opt, Orsay, France. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Bergeson, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Baldwin, Kenneth/A-4928-2008; rolston, steven/L-5175-2013; Bergeson, Scott/L-8959-2013 OI Baldwin, Kenneth/0000-0002-2043-5330; rolston, steven/0000-0003-1671-4190; Bergeson, Scott/0000-0002-3124-9226 NR 59 TC 11 Z9 11 U1 0 U2 3 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 1999 VL T83 BP 76 EP 82 DI 10.1238/Physica.Topical.083a00076 PG 7 WC Physics, Multidisciplinary SC Physics GA 262UM UT WOS:000084084900010 ER PT J AU Kelleher, DE Martin, WC Wiese, WL Sugar, J Fuhr, JR Olsen, K Musgrove, A Mohr, PJ Reader, J Dalton, GR AF Kelleher, DE Martin, WC Wiese, WL Sugar, J Fuhr, JR Olsen, K Musgrove, A Mohr, PJ Reader, J Dalton, GR TI The new NIST Atomic Spectra Database SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 6th International Colloquium on Atomic Spect and Oscillator Strengths (ASOS 6) CY AUG 09-13, 1998 CL UNIV VICTORIA, VICTORIA, CANADA SP Herzberg Inst Astrophys, Natl Res Council Canada, Natl Inst Stand & Technol, Univ Victoria, Dept Phys & Astron HO UNIV VICTORIA ID ENERGY-LEVEL CLASSIFICATIONS; TRANSITION-PROBABILITIES; AL-XIII; S-XVI; WAVELENGTHS; COMPILATION; IONIZATION; MAGNESIUM; ALUMINUM; SULFUR AB The new Atomic Spectra Database (ASD), Version 2.0, of the National Institute of Standards and Technology (NIST) contains significantly more data and covers a wider range of atomic and ionic transitions and energy levels than earlier versions. AU data are integrated. It also has a new user interface and search engine. ASD contains spectral reference data which have been critically evaluated and compiled by NIST. Version 2.0 contains data on 900 spectra, with about 70 000 energy levels and 91 000 lines ranging from about I Angstrom ngstrom to 200 micrometers, roughly half of which have transition probabilities with estimated uncertainties. References to the NIST compilations and original data sources are listed in the ASD bibliography. A detailed "Help" file serves as a user's manual, and full search and filter capabilities are provided. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kelleher, DE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 34 TC 8 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1999 VL T83 BP 158 EP 161 DI 10.1238/Physica.Topical.083a00158 PG 4 WC Physics, Multidisciplinary SC Physics GA 262UM UT WOS:000084084900022 ER PT J AU Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Wallbank, B Woitke, O AF Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Wallbank, B Woitke, O TI Near-threshold electron-impact excitation of multiply-charged be-like ions SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT IX International Conference on Physics of Highly Charged Ions CY SEP 09-14, 1998 CL BENSHEIM, GERMANY ID BEAMS AB Absolute total cross sections for excitation of the Be-like ions C(2+), N(3+) and O(4+) at electron energies close to the thresholds have been measured. For all three ions, cross sections for the resonance transition 2s(2) (1)S --> 2s2p (1)p were determined. Theoretical cross sections calculated using close-coupling approximations are in reasonably good agreement with the measured cross sections. Some data were also obtained for transitions from the metastable 2s2p (3)P states of C(2+) and O(4+). C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Chungnam Natl Univ, Taejon 3005761, South Korea. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. St Francis Xavier Univ, Antigonish, NS B2G 2W5, Canada. RP Smith, ACH (reprint author), UCL, Dept Phys & Astron, London WC1E 6BT, England. EM banniste@mail.phy.ornl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1999 VL T80B BP 283 EP 284 DI 10.1238/Physica.Topical.080a00283 PG 2 WC Physics, Multidisciplinary SC Physics GA 227RH UT WOS:000082093100046 ER PT J AU Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Takacs, E AF Chantler, CT Paterson, D Hudson, LT Serpa, FG Gillaspy, JD Takacs, E TI Precision X-ray spectroscopy at the NIST electron-beam ion trap: Resolution of major systematic error SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT IX International Conference on Physics of Highly Charged Ions CY SEP 09-14, 1998 CL BENSHEIM, GERMANY ID INTERVAL AB Some of the most critical tests of the QED Lamb shifts are currently being pursued in the X-ray regime by investigating the core levels of medium Z atoms such as vanadium. Toe current approach to the measurement of the Lamb shift in such a system is outlined. We present major progress in understanding and reducing the systematic errors within our system. The error budget has been reduced to a level where critical tests of QED can be performed. Recent observations of Lyman a in hydrogenic vanadium at the NIST Electron-Beam Ion Trap are presented. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. Lajos Kossuth Univ, Expt Phys Dept, H-4026 Debrecen, Hungary. Hungarian Acad Sci, Inst Nucl Res, ATOMKI, Debrecen, Hungary. RP Chantler, CT (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 14 TC 13 Z9 13 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 1999 VL T80B BP 440 EP 442 DI 10.1238/Physica.Topical.080a00440 PG 3 WC Physics, Multidisciplinary SC Physics GA 227RH UT WOS:000082093100111 ER PT J AU Louis, F Burgess, DR Rayez, MT Sawerysyn, JP AF Louis, F Burgess, DR Rayez, MT Sawerysyn, JP TI Kinetic study of the reactions of CF3O2 radicals with Cl and NO SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID PRODUCT BRANCHING RATIOS; RATE CONSTANTS; GAS-PHASE; GAUSSIAN-2 THEORY; PEROXY-RADICALS; SELF-REACTION; UPPER LIMITS; TEMPERATURE; THERMOCHEMISTRY; ENERGIES AB Kinetic studies of the reactions CF3O2+Cl and CF3O2+NO were performed at room temperature in the gas phase using the discharge flow mass spectrometric technique (DFMS). The reactions were investigated under pseudo-first-order conditions with Cl or NO in large excess with respect to the CF3O2 radicals. The rate constant for the reaction CF3O2+NO was measured at 298 K and the value of (1.6 +/- 0.3)x10(-11) cm(3) molecule(-1) s(-1) is in very good agreement with all previous values. For the reaction CF3O2+Cl, we obtain a rate constant at 298 K of (4.2 +/- 0.8)x10(-11) cm(3) molecule(-1) s(-1) in excellent agreement with the only published value. Product analysis shows that this reaction occurs via the major reaction pathway CF3O2+Cl --> CF3O+ClO at room temperature. In addition, an ab initio theoretical study was performed to gain insights on the different postulated reaction pathways. There is a significant disagreement between experimental and ab initio values recommended for the formation enthalpies of CF2O, CF3O and related molecules produced in this system. Consequently, we provide self-consistent values of enthalpies based on isodesmic reactions for the CF3O2+Cl reaction system using the G2, G2(MP2) and CBS-Q methods. These values are also compared with BAC-MP4 heats of formation calculated in this work. C1 Univ Sci & Technol Lille, Ctr Etud & Rech Lasers & Applicat, Lab Cinet & Chim Combust, CNRS,UMR 8522, F-59655 Villeneuve Dascq, France. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Univ Bordeaux 1, Lab Physicochim Mol, CNRS, UMR 5803, F-33405 Talence, France. RP Louis, F (reprint author), Univ Sci & Technol Lille, Ctr Etud & Rech Lasers & Applicat, Lab Cinet & Chim Combust, CNRS,UMR 8522, F-59655 Villeneuve Dascq, France. OI Louis, Florent/0000-0002-9533-557X NR 61 TC 16 Z9 16 U1 1 U2 3 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. PY 1999 VL 1 IS 22 BP 5087 EP 5096 DI 10.1039/a905933d PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 254PZ UT WOS:000083622500003 ER PT J AU Deng, JQ Mileti, G Drullinger, RE Jennings, DA Walls, FL AF Deng, JQ Mileti, G Drullinger, RE Jennings, DA Walls, FL TI Noise considerations for locking to the center of a Lorentzian line SO PHYSICAL REVIEW A LA English DT Article AB Many areas of science require locking a probe signal to the center of a Lorentzian line. In this paper we experimentally explore the limits to the resolution for locking a sine-wave modulated probe signal to a Lorentzian line. Surprisingly we find that in some cases relatively high-frequency phase modulation (PM) noise on the probe signal (even 100 times the Linewidth of the resonance) can significantly degrade the stability of the lock The 6.835-GHz hyperfine transition in Rb-87 was used as a test bed for these studies because it affords very high resolution for investigating this effect. The details presented here should prove useful for testing a complete theory of this effect and give some insight into the requirements of PM noise of local oscillators to be locked to a Lorentzian line. [S1050-2947(99)02401-4]. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Deng, JQ (reprint author), Datum Inc, 3 Parker, Irvine, CA 92618 USA. NR 11 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 1999 VL 59 IS 1 BP 773 EP 777 DI 10.1103/PhysRevA.59.773 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 158JD UT WOS:000078111500097 ER PT J AU Miranda, SG Muniz, SR Telles, GD Marcassa, LG Helmerson, K Bagnato, VS AF Miranda, SG Muniz, SR Telles, GD Marcassa, LG Helmerson, K Bagnato, VS TI "Dark-spot" atomic-beam slowing for on-axis loading of traps SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; ZEEMAN TUNING TECHNIQUE; INTENSITY DEPENDENCE; MAGNETOOPTICAL TRAP; STOPPING ATOMS; SODIUM ATOMS; LASER-LIGHT; DECELERATION; VAPOR; FIELD AB We have performed continuous slowing of an atomic beam to load a magneto-optical trap (MOT) on axis. To avoid the undesirable effects of the strong slowing laser on the performance of the MOT, a dark spot in the center of the slowing laser beam is used. We varied the spot size and the slowing-laser frequency and intensity to optimize the number of trapped atoms. Our "dark-spot'' slowing increased the number of trapped atoms by a factor of 30, allowing us to trap similar to 10(9) atoms in the MOT. [S1050-2947(99)00401-1]. C1 Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Miranda, SG (reprint author), Univ Sao Paulo, Inst Fis Sao Carlos, Caixa Postal 369, BR-13560970 Sao Carlos, SP, Brazil. RI Muniz, Sergio/G-6426-2012; Marcassa, Luis/H-3158-2012; Helmerson, Kristian/E-3683-2013; Bagnato, Vanderlei/C-3133-2012; TELLES, GUSTAVO/G-1504-2013; Sao Carlos Institute of Physics, IFSC/USP/M-2664-2016 OI Muniz, Sergio/0000-0002-8753-4659; Marcassa, Luis/0000-0003-4047-8984; TELLES, GUSTAVO/0000-0002-7026-316X; NR 23 TC 24 Z9 25 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 1999 VL 59 IS 1 BP 882 EP 885 DI 10.1103/PhysRevA.59.882 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 158JD UT WOS:000078111500113 ER PT J AU Prevedelli, M Cataliotti, FS Cornell, EA Ensher, JR Fort, C Ricci, L Tino, GM Inguscio, M AF Prevedelli, M Cataliotti, FS Cornell, EA Ensher, JR Fort, C Ricci, L Tino, GM Inguscio, M TI Trapping and cooling of potassium isotopes in a double-magneto-optical-trap apparatus SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; ULTRACOLD K-39 ATOMS; PHOTOASSOCIATIVE SPECTROSCOPY; COLLISIONS AB We report on the efficient operation of a double-magneto-optical-trap (MOT) apparatus for potassium isotopes. Mechanisms for the cooling and the transfer between the two MOTs are studied. A magnetic quadrupole trap has been loaded from the second MOT; density and temperature appear to be promising for starting runaway evaporative cooling. [S1050-2947(99)03201-1]. C1 INFM, European Lab Non Linear Spect, LENS, I-50125 Florence, Italy. Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Trent, Dipartimento Fis, INFM, I-38050 Trent, Italy. Univ Naples Federico II, Dipartimento Sci Fisiche, INFM, I-80126 Naples, Italy. RP Prevedelli, M (reprint author), INFM, European Lab Non Linear Spect, LENS, Largo E Fermi 2, I-50125 Florence, Italy. RI Ricci, Leonardo/B-4207-2009; Cataliotti, Francesco/K-4772-2015; OI Ricci, Leonardo/0000-0001-9454-0988; Cataliotti, Francesco/0000-0003-4458-7977; FORT, Chiara/0000-0001-8817-3077; Tino, Guglielmo M./0000-0002-7944-9825; Prevedelli, Marco/0000-0002-3136-2392 NR 13 TC 28 Z9 28 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 1999 VL 59 IS 1 BP 886 EP 888 DI 10.1103/PhysRevA.59.886 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 158JD UT WOS:000078111500114 ER PT J AU Bennett, SC Roberts, JL Wieman, CE AF Bennett, SC Roberts, JL Wieman, CE TI Measurement of the dc Stark shift of the 6S -> 7S transition in atomic cesium SO PHYSICAL REVIEW A LA English DT Article ID PARITY NONCONSERVATION; 6S-7S TRANSITION; LIFETIME; STATE; PHYSICS AB We have measured the de Stark shift of the 6S-->17S transition in atomic cesium using laser spectroscopy. The result of our experiment is 0.7262(8) Hz(V/cm)(-2). This value disagrees with a previous experiment but is within 0.3% of the value predicted by ab initio calculations. This measurement removes the largest outstanding disagreement between experiment and ab initio theory of low-lying states in atomic cesium. [S1050-2947(99)51101-3]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Bennett, SC (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 15 TC 18 Z9 18 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 1999 VL 59 IS 1 BP R16 EP R18 DI 10.1103/PhysRevA.59.R16 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 158JD UT WOS:000078111500005 ER PT J AU Williams, J Walser, R Cooper, J Cornell, E Holland, M AF Williams, J Walser, R Cooper, J Cornell, E Holland, M TI Nonlinear Josephson-type oscillations of a driven, two-component Bose-Einstein condensate SO PHYSICAL REVIEW A LA English DT Article ID RELATIVE PHASE; DYNAMICS; ATOMS AB We propose an experiment that would demonstrate nonlinear Josephson-type oscillations in the relative population of a driven, two-component Bose-Einstein condensate. An initial state is prepared in which two condensates exist in a magnetic trap, each in a different hyperfine state, where the initial populations and relative phase between condensates can be controlled within experimental uncertainty. A weak driving field is then applied, which couples the two internal states of the atom and consequently transfers atoms back and forth between condensates. We present a model of this system and investigate the effect of the mean field on the dynamical evolution. [S1050-2947(99)50801-9]. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80309 USA. RP Williams, J (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 21 TC 133 Z9 133 U1 3 U2 9 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 JAN PY 1999 VL 59 IS 1 BP R31 EP R34 DI 10.1103/PhysRevA.59.R31 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 158JD UT WOS:000078111500009 ER PT J AU Margadonna, S Prassides, K Neumann, DA Shimoda, H Iwasa, Y AF Margadonna, S Prassides, K Neumann, DA Shimoda, H Iwasa, Y TI Rotational dynamics of C-60 in (ND3)K3C60 SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; INELASTIC NEUTRON-SCATTERING; SUPERCONDUCTING NA2CSC60; MOLECULAR-DYNAMICS; INTERCALATION; LIBRATIONS; NA2RBC60; AMMONIA; RB3C60; A3C60 AB The orientational dynamics of C-60 in the ammoniated fulleride (ND3)K3C60 are studied by the neutron inelastic-scattering technique. Well-defined excitations are observed in the low-energy spectra with energies varying between 3.11(7) and 2.38(5) meV, as the temperature increases from 30 to 310 K. The dependence of their intensities on the scattering Vector is consistent with their assignment to small-amplitude librational motion of the C-60(3-) ions. The librations in (ND3)K3C60 are both softer and broader than;those in the parent fulleride K3C60, reflecting the existence of a weaker and more anisotropic orientational potential upon ammoniation. The estimated barrier of the hindrance potential, E(a)similar to 250 meV is approximately half the size of that in K3C60 and comparable to that found in the primitive cubic fulleride Na2RbC60. The temperature dependence of the energies and widths of the librational peaks in (ND3)K3C60 is also more reminiscent of the behavior of Na2RbC60 rather than K3C60 The result has been rationalized by involving crystal-packing arguments, related to the increase in size of the tetrahedral interstices upon ammoniation. [S0163-1829(99)13401-5]. C1 Univ Sussex, Sch Chem Phys & Environm Studies, Brighton BN1 9QJ, E Sussex, England. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Japan Adv Inst Sci & Technol, Tatsunokuchi, Ishikawa 92312, Japan. RP Margadonna, S (reprint author), Univ Sussex, Sch Chem Phys & Environm Studies, Brighton BN1 9QJ, E Sussex, England. RI Prassides, Kosmas/C-9804-2009; Iwasa, Yoshihiro/C-1719-2009 NR 27 TC 6 Z9 7 U1 0 U2 1 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 JAN 1 PY 1999 VL 59 IS 2 BP 943 EP 947 DI 10.1103/PhysRevB.59.943 PG 5 WC Physics, Condensed Matter SC Physics GA 158JE UT WOS:000078111600034 ER PT J AU Hammar, PR Stone, MB Reich, DH Broholm, C Gibson, PJ Turnbull, MM Landee, CP Oshikawa, M AF Hammar, PR Stone, MB Reich, DH Broholm, C Gibson, PJ Turnbull, MM Landee, CP Oshikawa, M TI Characterization of a quasi-one-dimensional spin-1/2 magnet which is gapless and paramagnetic for g mu H-B less than or similar to J and k(B)T << J SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; S=1/2 ANTIFERROMAGNET; HEISENBERG-ANTIFERROMAGNET; LINEAR-CHAIN; FIELD; CHARGE; COPPER(II); COMPLEXES; NEUTRON; HEAT AB High-field magnetization, field-dependent specific heat measurements, and zero-field inelastic magnetic neutron scattering have been used to explore the magnetic properties of copper pyrazine dinitrate [Cu(C4H4N2)(NO3)(2)] The material is an ideal one-dimensional spin-1/2 Heisenberg antiferromagnet with nearest-neighbor exchange constant J=0.90(l) meV and chains extending along the orthorhombic a direction. As opposed to previously studied molecular-based spin-1/2 magnetic systems, copper pyrazine dinitrate remains gapless and paramagnetic for g mu(B)H/J at least up to 1.4 and for k(B)T/J at least down to 0.03. This makes the material an excellent model system for exploring the T=0 critical line that is expected in the H-T phase diagram of the one-dimensional spin-1/2 Heisenberg antiferromagnet. We present accurate measurements of the Sommerfeld constant of the spinon gas versus g mu(B)H/J<1.4 that reveal a decrease of the average spinon velocity by 32% in that field range. The results are in excellent agreement with numerical calculations based on the Bethe ansatz with no adjustable parameters. [S0163-1829(99)11201-3]. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Clark Univ, Carlson Sch Chem, Worcester, MA 01610 USA. Clark Univ, Dept Phys, Worcester, MA 01610 USA. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. RP Hammar, PR (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RI Broholm, Collin/E-8228-2011; Oshikawa, Masaki/F-4992-2011; Stone, Matthew/G-3275-2011 OI Broholm, Collin/0000-0002-1569-9892; Oshikawa, Masaki/0000-0002-7637-7432; Stone, Matthew/0000-0001-7884-9715 NR 42 TC 110 Z9 111 U1 2 U2 17 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 1 PY 1999 VL 59 IS 2 BP 1008 EP 1015 DI 10.1103/PhysRevB.59.1008 PG 8 WC Physics, Condensed Matter SC Physics GA 158JE UT WOS:000078111600043 ER PT J AU Fanesi, S Pozzi, G Bonevich, JE AF Fanesi, S Pozzi, G Bonevich, JE TI Influence of core misalignment and distortion on the Fresnel and holographic images of superconducting fluxons SO PHYSICAL REVIEW B LA English DT Article ID REAL-TIME OBSERVATION; LORENTZ MICROSCOPY; ELECTRON HOLOGRAPHY; VORTEX LATTICES; LINES; SPECIMENS; DEFECTS AB The model developed to interpret holographic and out-of-focus images of superconducting vortices or fluxons in thin specimens has been implemented to treat effects such as misorientation or even distortion of the flux line. It is shown that in this way the anomalous shape of some globules in out-of-focus images of the flux line lattice as well as the local trend of the interference fringes in holographic reconstructed images can be satisfactorily interpreted. [S0163-1829(99)01502-7]. C1 Univ Bologna, Dept Phys, I-40127 Bologna, Italy. Univ Bologna, Ist Nazl Fis Mat, I-40127 Bologna, Italy. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. Hitachi Ltd, Adv Res Lab, Hatoyama, Saitama 35003, Japan. RP Fanesi, S (reprint author), Univ Bologna, Dept Phys, Viale B Pichat 6-2, I-40127 Bologna, Italy. NR 16 TC 14 Z9 14 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 JAN 1 PY 1999 VL 59 IS 2 BP 1426 EP 1431 DI 10.1103/PhysRevB.59.1426 PG 6 WC Physics, Condensed Matter SC Physics GA 158JE UT WOS:000078111600095 ER PT J AU Wietfeldt, FE Schima, FJ Coursey, BM Hoppes, DD AF Wietfeldt, FE Schima, FJ Coursey, BM Hoppes, DD TI Long-term measurement of the half-life of Ti-44 SO PHYSICAL REVIEW C LA English DT Article ID RAY LINE EMISSION AB We report on a series of precisely calibrated measurements of the 1157-keV gamma-ray emission rate from the decay of a single source of Ti-44. These data were collected over a period of 20 years. We obtain a half-life of 60.7+/-1.2 years. [S0556-2813(99)04801-3]. C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. RP Wietfeldt, FE (reprint author), Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 21 TC 26 Z9 26 U1 0 U2 0 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 JAN PY 1999 VL 59 IS 1 BP 528 EP 530 DI 10.1103/PhysRevC.59.528 PG 3 WC Physics, Nuclear SC Physics GA 158JC UT WOS:000078111400059 ER PT J AU Sobolewski, MA AF Sobolewski, MA TI Experimental test of models of high-plasma-density, radio-frequency sheaths SO PHYSICAL REVIEW E LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; BOMBARDMENT ENERGY-DISTRIBUTIONS; DRIVEN RF DISCHARGES; RADIOFREQUENCY DISCHARGES; ELECTRICAL CHARACTERISTICS; REFERENCE CELL; IMPEDANCE MEASUREMENTS; ELECTRODE SHEATHS; GLOW-DISCHARGES; DYNAMIC-MODEL AB Measurements of the rf-bias current and voltage applied to the substrate electrode of a high-density plasma reactor, combined with de measurements of the ion current at the electrode and capacitive probe measurements of the plasma potential, enabled a rigorous, quantitative test of models of the electrical properties of the sheath adjacent to the electrode. The measurements were performed for argon discharges at 1.33 Pa (10 mTorr), ion current densities of 1.3-13 mA/cm(2), rf-bias frequencies of 0.1-10 MHz, and rf-bias voltages from less than I to more than 100 V. From the measurements, the current, voltage, impedance, and power of the sheath adjacent to the electrode were determined and were compared to model predictions. The properties of the opposing sheath, adjacent to grounded surfaces, were also determined. The behavior of the two sheaths ranged from nearly symmetric to very asymmetric. Changes in the symmetry are explained by models of the sheath impedance. [S1063-651X(99)03501-1]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sobolewski, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 53 TC 37 Z9 37 U1 1 U2 4 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 JAN PY 1999 VL 59 IS 1 BP 1059 EP 1072 DI 10.1103/PhysRevE.59.1059 PN B PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 158JJ UT WOS:000078112000052 ER PT J AU Soraas, F Aarsnes, K Lundblad, JA Evans, DS AF Soraas, F Aarsnes, K Lundblad, JA Evans, DS TI Enhanced pitch angle scattering of protons at mid-latitudes during geomagnetic storms SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article ID SAR ARC FORMATION; AURORAL RED ARCS; RING CURRENT; PLASMAPAUSE; ELECTRON AB During geomagnetic storms highly localized regions of enhanced proton (ion) precipitation in the tens to several hundred keV energy range can appear at mid-latitudes. The particle pitch angle distribution in these enhanced regions is anisotropic with maximum intensity perpendicular to the magnetic field. In a few cases, however, the distribution can approach isotropy. These regions typically have widths of a few degrees invariant latitude, but can be as narrow as 0.25 degrees. The intensity peak is most often concentrated in a specific particle energy range, although in many cases the intensity peak at a given location is distributed over a broader energy range. During the main phase of the storms the ion enhancement is mostly observed in the highest energy protons and only in the midnight/evening MLT sector. Coincident with the ion enhancement there was often an enhancement in electrons with energies > 300 keV. In the recovery phase of the storms the ion enhancement can be observed at all local times covered by our observations and there was not any coincident enhancement in the high energy electrons. Overall the observations seem to support a picture where scattering of protons into the loss cone by cyclotron resonant wave-particle interaction occurs, while high energy electrons are parasitically scattered into the loss cone by the same ion cyclotron waves. Throughout the storm the L-dependence of the enhancements in proton fluxes is similar to the K-p dependence of the location of the plasmapause. Whenever a direct comparison could be made, the SAR are and the ion enhancement overlap. Thus the ion enhancement and SAR are are associated, but not necessarily on a cause-effect basis. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Bergen, Dept Phys, Bergen, Norway. STATOIL, Bergen, Norway. NOAA, Space Environm Ctr, Boulder, CO USA. RP Soraas, F (reprint author), Univ Bergen, Dept Phys, Bergen, Norway. NR 15 TC 23 Z9 24 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 1999 VL 24 IS 1-3 BP 287 EP 292 DI 10.1016/S1464-1917(98)00041-5 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 238LM UT WOS:000082711800041 ER PT J AU Koloutsou-Vakakis, S Carrico, CM Li, Z Rood, MJ Ogren, JA AF Koloutsou-Vakakis, S Carrico, CM Li, Z Rood, MJ Ogren, JA TI Characterisation of aerosol properties and radiative forcing at an anthropogenically perturbed continental site SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article ID CLIMATE; SENSITIVITY; SULFATE; BUDGET; SIZE AB Measurements of optical, chemical and physical properties of ambient aerosol particles were obtained at a continental anthropogenically perturbed environment. For aerosol sampled at the site from January to December 1995, the mean gravimetric mass concentration for particles with diameter d(p) less than or equal to 1 mu m on 24-hr filter samples was 11.0 +/- 7.6 mu g/m(3). Ion chromatographic (IC) analysis chemically identified 50 +/- 15% of the total gravimetric mass for fine particles (d(p) less than or equal to 1 mu m). Most of the IC identified material (88 +/- 14%) consisted of NH(4)(+) and SO(4)(2-). Thermal optical reflectance (TOR) analysis of small number of samples showed that the material not identified with IC consisted of elemental and organic carbon. To examine the implications of the measurements and effect of their variation, the mean annual direct radiative forcing (<(Delta)over bar>(F) over bar(R)) due to aerosol particles at the site was estimated by a simple model using as input measured total light scattering coefficients, hemispheric backscatter ratio and hygroscopic growth factor. For a mean annual height of the mixed layer at 800 m, an assumed single scattering albedo (omega) value of 0.85 and wavelength 550 nm,<(Delta)over bar>(F) over bar(R) as function of relative humidity (RH) ranged between -0.51 +/- 0.47 (RH = 40%) and -0.63 +/- 0.58 (RH = 80%) W/m(2). Sensitivity tests pointed to the importance of accurate quantification of omega. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Cival & Environm Engn, Urbana, IL 61801 USA. Energen Consulting Inc, Germantown, MD 20874 USA. NOAA, Climate Modelling & Diagnost Lab, Boulder, CO 80803 USA. RP Koloutsou-Vakakis, S (reprint author), Natl Tech Univ Athens, Lab Meteorol, Phys Bldg V, GR-15784 Athens, Greece. RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 28 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 1999 VL 24 IS 5 BP 541 EP 546 DI 10.1016/S1464-1917(99)00088-4 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 250FX UT WOS:000083379300023 ER PT J AU Hubbell, JH AF Hubbell, JH TI Review of photon interaction cross section data in the medical and biological context SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Review ID RAY ATTENUATION COEFFICIENTS; ENERGY-ABSORPTION COEFFICIENTS; ATOMIC FORM-FACTORS; X-RAY; COMPTON-SCATTERING; PAIR PRODUCTION; INTERNATIONAL-UNION; RAYLEIGH-SCATTERING; MASS ATTENUATION; BOUND ELECTRONS AB The probability of a photon (x-ray, gamma-ray, bremsstrahlung, etc) of a given energy E undergoing absorption or scattering when traversing a layer of material Z can be expressed quantitatively in terms of a linear attenuation coefficient mu (cm(-1)). Since mu is dependent on the material's density, rho (g cm(-3)), which can be variable, the quantity usually tabulated is the mass attenuation coefficient mu/rho (cm(2) g(-1)) in which the dependence on the density has been removed. pip, in rum, can be obtained as the sum of the different types of possible interactions of photons with atoms of the material. For photon energies below 1 MeV the major interaction processes to be considered are incoherent (Compton) scattering, coherent (Rayleigh) scattering and atomic photoeffect absorption. Above 1 MeV one must also include nuclear-held pair production and atomic-field (triplet) production, and above 5 MeV one in principle should include photonuclear absorption, although the latter is neglected in data tabulations up to the present time. This review includes a selective history of measurements and theory relating to mu/rho from the turn of the century up to the present time, and is intended to provide a basis for further calculations and critical tabulations of photon cross section data, particularly as required by users in radiation medicine and biology. The mass energy-absorption coefficient mu(cn)/rho is also briefly discussed. RP Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 159 TC 151 Z9 153 U1 1 U2 17 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 EI 1361-6560 J9 PHYS MED BIOL JI Phys. Med. Biol. PD JAN PY 1999 VL 44 IS 1 BP R1 EP R22 DI 10.1088/0031-9155/44/1/001 PG 22 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 164EK UT WOS:000078449600001 PM 10071870 ER PT J AU Migdall, A AF Migdall, A TI Correlated-photon metrology without absolute standards SO PHYSICS TODAY LA English DT Article ID PARAMETRIC DOWNCONVERSION; EFFICIENCY C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Migdall, A (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 17 TC 99 Z9 104 U1 0 U2 3 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 JAN PY 1999 VL 52 IS 1 BP 41 EP 46 DI 10.1063/1.882570 PG 6 WC Physics, Multidisciplinary SC Physics GA 154BA UT WOS:000077867100009 ER PT S AU Rodin, AV Clancy, RT Wilson, RJ AF Rodin, AV Clancy, RT Wilson, RJ BE Zasova, LV TI Dynamical properties of Mars water ice clouds and their interactions with atmospheric dust and radiation SO PLANETARY ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT c3 1 Symposium of COSPAR Scientific Commission C Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Ctr Natl Etudes Spatiales, European Space Agcy, Comm Space Res ID MARTIAN ATMOSPHERE; MODEL; PHOBOS; VAPOR AB A fully coupled zonally-averaged one-dimensional time marching model of the Martian atmosphere is discussed. The model incorporates interactively radiation transfer, microphysics and eddy transport of both mineral and volatile aerosols. It is shown that nonlinear feedback caused by water ice clouds may result in quick (with a timescale of several days) reconfiguration of dust vertical distribution and thermal profile. Given different initial conditions, aerosols distribution and temperatures may equilibrate to different steady states. This might give a clue to understanding of the interannual variability of the seasonal temperature trend on Mars, particularly near aphelion. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 Moscow Space Res Inst, Moscow 117810, Russia. Space Sci Inst, Boulder, CO USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Rodin, AV (reprint author), Moscow Space Res Inst, Profsoyuznaya 84-32, Moscow 117810, Russia. RI Rodin, Alexander/L-1904-2013 OI Rodin, Alexander/0000-0002-3601-7790 NR 11 TC 21 Z9 21 U1 2 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 1999 VL 23 IS 9 BP 1577 EP 1585 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP13P UT WOS:000084217600005 ER PT S AU Shaw, JA Descour, M Sabatke, D Garcia, J Dereniak, E AF Shaw, JA Descour, M Sabatke, D Garcia, J Dereniak, E BE Goldstein, DH Chenault, DB TI Measurements of midwave and longwave infrared polarization from water SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING II SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing II CY JUL 19-21, 1999 CL DENVER, CO SP SPIE DE infrared polarization; polarimetry; remote sensing ID EMISSION POLARIZATION; RECOGNITION AB In the largely unpolarized natural infrared environment, water stands out as a notably polarized source. Water surfaces appear partially polarized in the infrared through both reflection and emission. This polarization can be significant in environmental and military remote sensing applications where the water is either the intended source or possibly a false target, In this paper we shaw and interpret measurements in midwave (similar to 4-5 mu m) and longwave (similar to 10-11.5 mu m) infrared bands. The midwave images show up to 7% s polarization (horizontal) in regions where warm objects reflect from the water. The longwave data also show s polarization in legions of sunglint, but elsewhere exhibit p polarization (vertical). Where the background is clear sky, the longwave signal is p polarized by up to 5% at large incidence angles. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Shaw, JA (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. EM jshaw@etl.noaa.gov NR 16 TC 4 Z9 4 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 0-8194-3240-7 J9 PROC SPIE PY 1999 VL 3754 BP 118 EP 125 DI 10.1117/12.366322 PG 8 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BP12A UT WOS:000084180100013 ER PT S AU Kaplan, SG Hanssen, LM AF Kaplan, SG Hanssen, LM BE Goldstein, DH Chenault, DB TI FT-IR based ellipsometer using high-quality Brewster-angle polarizers SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing II CY JUL 19-21, 1999 CL DENVER, CO SP SPIE DE polarizer; ellipsometry; infrared; index of refraction AB A Fourier transform infrared (FT-IR) spectrometer-based broadband infrared ellipsometer has been developed around a pair of high-quality Brewster angle polarizers. These polarizers consist of four Ge plates in a chevron geometry and have been measured to have extinction ratios of less than 10(-5) in the infrared spectral region. The ellipsometer can be used in transmission or reflection mode for angles of incidence of 10 degrees to near grazing (dependent upon sample size). We describe the design and construction of the ellipsometer and initial testing of the system using measurements on Si wafers from 2 mu m to 12 mu m wavelength. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Kaplan, SG (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3240-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3754 BP 285 EP 293 DI 10.1117/12.366338 PG 9 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BP12A UT WOS:000084180100031 ER PT J AU Bamford, HA Poster, DL Baker, JE AF Bamford, HA Poster, DL Baker, JE TI Method for measuring the temperature dependence of the Henry's Law Constant of selected polycyclic aromatic hydrocarbons SO POLYCYCLIC AROMATIC COMPOUNDS LA English DT Article DE Henry's law constant; gas-stripping method; polycyclic aromatic hydrocarbons ID POLYCHLORINATED-BIPHENYLS; WATER AB The Henry's Law Constant (HLC) is an important thermodynamic constant needed to model air-water exchange of contaminants such as polycyclic aromatic hydrocarbons (PAHs). However, few direct HLC measurements have been reported for PAHs. A gas-stripping apparatus was constructed to allow gaseous and dissolved phase PAH concentrations to be measured over time. HLC was calculated by two methods: measuring PAH loss in the dissolved phase over time and dividing the instantaneous air by dissolved phase concentrations. Both methods yielded similar HLC values that were comparable to the range of HLCs reported in the literature. C1 Univ Maryland, Chesapeake Biol Lab, Ctr Environm Sci, Solomons, MD 20688 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Bamford, HA (reprint author), Univ Maryland, Chesapeake Biol Lab, Ctr Environm Sci, Solomons, MD 20688 USA. RI Baker, Joel/A-9685-2011 OI Baker, Joel/0000-0002-9980-7781 NR 15 TC 7 Z9 7 U1 0 U2 8 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1040-6638 J9 POLYCYCL AROMAT COMP JI Polycycl. Aromat. Compd. PY 1999 VL 14 BP 11 EP 22 DI 10.1080/10406639908019107 PG 12 WC Chemistry, Organic SC Chemistry GA 297HC UT WOS:000086076000003 ER PT J AU Poster, DL De Alda, MJL Schantz, MM Sander, LC Vangel, MG Wise, SA AF Poster, DL De Alda, MJL Schantz, MM Sander, LC Vangel, MG Wise, SA TI Certification of a diesel particulate related Standard Reference Material (SRM 1975) for PAHs SO POLYCYCLIC AROMATIC COMPOUNDS LA English DT Article DE diesel particles; standard reference materials; PAHs; environmental samples; gas chromatography; liquid chromatography ID POLYCYCLIC AROMATIC-HYDROCARBONS; GAS-CHROMATOGRAPHY; SHAPE SELECTIVITY; STATIONARY PHASES; LIQUID AB Standard Reference Materials (SRMs) are Certified Reference Materials issued by the National Institute of Standards and Technology (NIST). Three of these materials, SRMs 1975 (Diesel Particulate Extract), 2975 (Diesel Particulate Matter, Industrial Forklift), and 1650 (Diesel Particulate Matter) are diesel particulate-related materials that are well characterized for PAH isomer distributions. SRM 1975 is a methylene chloride extract of industrial forklift diesel particulate matter and it was developed originally in response to the needs of the bioassay community for a natural environmental extract. Thirty-nine PAHs (or combinations of PAHs) were determined in SRM 1975 using various combinations of four different methods of analysis. SRM 1975 will be issued with certified concentrations for eight PAHs. In addition, reference concentrations will be provided for additional PAHs, including many alkyl substituted isomers such as methylphenanthrenes, methylpyrenes, and methylfluoranthenes. Reference values for the mutagenic activity of the extract will also be provided. The approach and results for the certification of PAH concentrations in SRM 1975 are described in this paper. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Poster, DL (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RI Lopez de Alda, Miren/E-3357-2014 OI Lopez de Alda, Miren/0000-0002-9347-2765 NR 10 TC 8 Z9 8 U1 1 U2 4 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1040-6638 J9 POLYCYCL AROMAT COMP JI Polycycl. Aromat. Compd. PY 1999 VL 14 BP 23 EP 31 DI 10.1080/10406639908019108 PG 9 WC Chemistry, Organic SC Chemistry GA 297HC UT WOS:000086076000004 ER PT J AU Wise, SA Sander, LC Schantz, MM Hays, MJ Benner, BA AF Wise, SA Sander, LC Schantz, MM Hays, MJ Benner, BA TI Recertification of standard reference material (SRM) 1649, urban dust, for the determination of polycyclic aromatic hydrocarbons (PAHs) SO POLYCYCLIC AROMATIC COMPOUNDS LA English DT Article DE Certified Reference Materials (CRMs); gas chromatography/mass spectrometry; (GC/MS); liquid chromatography; polycyclic aromatic hydrocarbons (PAHs); Standard Reference Materials (SRMs) ID SUPERCRITICAL-FLUID EXTRACTION; LIQUID-CHROMATOGRAPHIC DETERMINATION; TRACE ORGANIC-CONSTITUENTS; AIR PARTICULATE EXTRACTS; COMPLEX-MIXTURES; ENVIRONMENTAL-SAMPLES; STATIONARY PHASES; CHEMICAL-ANALYSIS; MARINE SEDIMENT; AMBIENT AIR AB The National Institute of Standards and Technology (NIST) recently issued SRM 1649a, Urban Dust, with certified and reference values for 44 polycyclic aromatic hydrocarbons (PAHs). This material is a recertification of SRM 1649 which was issued in 1982 with certified values for only five PAHs. The PAHs were determined using the following analytical techniques: (1) reversed-phase liquid chromatography with fluorescence detection (LC-FL) for analysis of the total PAH fraction, (2) reversed-phase LC-FL for analysis of isomeric PAH fractions isolated by normal-phase LC (i.e., multidimensional LC), and (3) gas chromatography/mass spectrometry (GC/MS) for analysis of the PAH fraction using three different stationary phases, each with different selectivity for PAH separations. The results from the different techniques are compared and discussed. SRM 1649a is currently the most extensively characterized environmental matrix SRM with respect to PAH constituents. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Wise, SA (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 66 TC 8 Z9 7 U1 6 U2 13 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1040-6638 J9 POLYCYCL AROMAT COMP JI Polycycl. Aromat. Compd. PY 1999 VL 13 IS 4 BP 419 EP 456 PG 38 WC Chemistry, Organic SC Chemistry GA 311QN UT WOS:000086895900006 ER PT J AU Wang, ZT Jiang, DD Wilkie, CA Gilman, JW AF Wang, ZT Jiang, DD Wilkie, CA Gilman, JW TI Further studies on fire retardant polystyrene by Friedel-Crafts chemistry SO POLYMER DEGRADATION AND STABILITY LA English DT Article AB The combination of a copolymer of 4-vinylbenzyl alcohol and styrene with 2-ethylhexyldiphenylphosphate (DPP) and with metal chlorides has been studied by TGA, radiative gasification, Cone Calorimetry, and oxygen index measurements. Evidence is presented in support of a cross-linking reaction with the additives and the copolymer, which proceeds through a Friedel-Crafts mechanism. This approach reduces the peak heat release rate (HRR) by 60% as measured in the Cone Calorimeter. There is a significant reduction in the mass loss rate during the thermal degradation, and evidence of char formation is observed in the radiative gasification experiments. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Marquette Univ, Dept Chem, Milwaukee, WI 53201 USA. Natl Inst Stand & Technol, Mat Fire Res Grp, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Wilkie, CA (reprint author), Marquette Univ, Dept Chem, POB 1881, Milwaukee, WI 53201 USA. NR 8 TC 13 Z9 14 U1 0 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-3910 J9 POLYM DEGRAD STABIL JI Polym. Degrad. Stabil. PY 1999 VL 66 IS 3 BP 373 EP 378 DI 10.1016/S0141-3910(99)00089-0 PG 6 WC Polymer Science SC Polymer Science GA 249JP UT WOS:000083330200010 ER PT J AU Martin, JW Chin, JW Byrd, WE Embree, E Kraft, KM AF Martin, JW Chin, JW Byrd, WE Embree, E Kraft, KM TI An integrating sphere-based ultraviolet exposure chamber design for the photodegradation of polymeric materials SO POLYMER DEGRADATION AND STABILITY LA English DT Article ID PHOTOREACTOR; PROFILES; FIELD AB The primary method for obtaining laboratory weathering data for a wide range of commercial polymer products including coatings, textiles, elastomers, plastics and polymeric composites is through the use of ultraviolet radiation exposure chambers (UV-chambers). Although numerous improvements have been made in the design of W-chambers over the last 80 years, the repeatability and reproducibility of the exposure results from these chambers have remained elusive. This lack of reproducibility and repeatability is attributed to systematic errors in their design, operation, and control which, in turn, has prevented comparisons of the performance of competing construction materials exposed in the same environment, comparisons of the performance of the same material exposed in different laboratories, and the comparison of field and laboratory results. The paper re-examines current UV-chamber designs, discusses possible sources of systematic error associated with these chambers, and describes an innovative UV-chamber design having a basis in integrating sphere technology which greatly reduces the magnitude of these errors. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Chin, JW (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 62 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-3910 J9 POLYM DEGRAD STABIL JI Polym. Degrad. Stabil. PY 1999 VL 63 IS 2 BP 297 EP 304 DI 10.1016/S0141-3910(98)00109-8 PG 8 WC Polymer Science SC Polymer Science GA 168YU UT WOS:000078721400019 ER PT J AU Evans, C Estler, WT AF Evans, C Estler, WT TI A look to the future SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Editorial Material C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Estler, WT (reprint author), NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 0 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD JAN PY 1999 VL 23 IS 1 BP 1 EP 1 PG 1 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA 184FF UT WOS:000079599200001 ER PT B AU Damazo, BN Davies, MA Dutterer, BS Kennedy, MD AF Damazo, BN Davies, MA Dutterer, BS Kennedy, MD BE McKeown, P TI A summary of micro-milling studies SO PRECISION ENGINEERING, NANOTECHNOLOGY, VOL 1, PROCEEDINGS LA English DT Proceedings Paper CT 1st International Conference and General Meeting of the European-Society-for-Precision-Engineering and Nanotechnology CY MAY 31-JUN 04, 1999 CL Bremen, GERMANY SP European Soc Precis Engn & Nanotechnol C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Damazo, BN (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 9 Z9 9 U1 1 U2 2 PU SHAKER VERLAG GMBH PI AACHEN PA POSTFACH 1290, AACHEN, 52013, GERMANY BN 3-8265-6085-X PY 1999 BP 322 EP 325 PG 4 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BAN63 UT WOS:000222984000079 ER PT B AU Evans, CJ AF Evans, CJ BE McKeown, P Corbett, J Bonis, M Sartori, S Kunzmann, H Weck, M Brinksmeier, E Preub, W TI Next generation interferometry for optical figure metrology SO PRECISION ENGINEERING, NANOTECHNOLOGY, VOL. 2 LA English DT Proceedings Paper CT 1st International Conference and General Meeting of the European-Society-for-Precision-Engineering and Nanotechnology CY MAY 31-JUN 04, 1999 CL Bremen, GERMANY SP European Soc Precis Engn & Nanotechnol C1 Natl Inst Stand & Technol, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. RP Evans, CJ (reprint author), Natl Inst Stand & Technol, Automated Prod Technol Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SHAKER VERLAG GMBH PI AACHEN PA POSTFACH 1290, AACHEN, 52013, GERMANY PY 1999 BP 307 EP 307 PG 1 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BAP16 UT WOS:000223103000073 ER PT B AU Yuan, YB Song, JF Vorburger, TV AF Yuan, YB Song, JF Vorburger, TV BE McKeown, P Corbett, J Bonis, M Sartori, S Kunzmann, H Weck, M Brinksmeier, E Preub, W TI High accuracy high speed Gaussian filter in surface metrology SO PRECISION ENGINEERING, NANOTECHNOLOGY, VOL. 2 LA English DT Proceedings Paper CT 1st International Conference and General Meeting of the European-Society-for-Precision-Engineering and Nanotechnology CY MAY 31-JUN 04, 1999 CL Bremen, GERMANY SP European Soc Precis Engn & Nanotechnol AB Both (1 + x(2))(-n) and (sin x/x)(n) functions are very close to the Gaussian distribution for large value of n. Based on these functions, two new algorithms are developed for designing high accuracy and high speed recursive type Gaussian digital filters. The relationships between the Gaussian filtering and the classical 2RC filtering and between the Gaussian filtering and the moving average filtering are also discussed. C1 NIST, Gaithersburg, MD 20899 USA. RP Yuan, YB (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SHAKER VERLAG GMBH PI AACHEN PA POSTFACH 1290, AACHEN, 52013, GERMANY PY 1999 BP 507 EP 510 PG 4 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BAP16 UT WOS:000223103000124 ER PT S AU Muth, LA AF Muth, LA GP IEEE IEEE TI Calibration standards and uncertainties in radar cross section measurements SO PROCEEDINGS OF THE 1999 IEEE RADAR CONFERENCE: RADAR INTO THE NEXT MILLENNIUM SE Radar Conference LA English DT Proceedings Paper CT 1999 IEEE Radar Conference on Radar Into the Next Millennium CY APR 20-22, 1999 CL WALTHAM, MA SP IEEE Boston Sect, IEEE Aerospace & Electr Syst Soc DE calibration; calibration artifacts; cylinders; dihedrals; model consistency; monostatic measurements; polarimetric measurements; radar cross section; uncertainty AB Standards for radar cross section measurements are being developed cooperatively by NIST and DoD scientists. Three technical areas were defined as the foundation of such an effort: (1) monostatic single-channel calibration, (2) full polarimetric calibration using a scattering matrix formalism, and (3) analysis of radar cross section calibration and measurement uncertainty. In this paper I review the results of assessment of calibration data accuracy using a set of cylinders as artifact standards, examine the theory of polarimetric calibrations, and discuss essential areas of radar cross section uncertainty analysis. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Muth, LA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-4977-6 J9 RADAR CONF PY 1999 BP 326 EP 331 DI 10.1109/NRC.1999.767360 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BN39H UT WOS:000081778900063 ER PT B AU Collette, BB AF Collette, BB BE Seret, B Sire, JY TI Mackerels, molecules, and morphology SO PROCEEDINGS OF THE 5TH INDO-PACIFIC FISH CONFERENCE LA English DT Proceedings Paper CT 5th Indo-Pacific Fish Conference CY NOV 03-08, 1997 CL NOUMEA, NEW CALEDONIA SP French Soc Ichthyol Soc DE Scombridae; Thunnini; tunas; mackerels; Spanish mackerels; taxonomy ID PHYLOGENETIC-RELATIONSHIPS; THUNNUS-ALBACARES; YELLOWFIN TUNA; SCOMBRIDAE; TELEOSTEI; SCOMBER; OCEAN AB Current classification of the Scombridae, based largely on morphology, is compared with recent molecular studies in nine cases. I. The wahoo, Acanthocybium solandri, is confirmed as a scombrid, not a billfish. LI. Relationships within the Thunnini are confirmed with Auxis the sister-group of the rest of the tribe, and then Euthynnus, Katsuwonus, and finally, Thunnus. III. Monophyly of the genus Thunnus is confirmed. TV. Monophyly of the subgenus Neothunnus of the genus Thunnus is confirmed but monophyly of the subgenus Thunnus is problematical. V. North Atlantic and North Pacific subspecies of the bluefin tuna, Thunnus thynnus, are better considered as full species, T. thynnus and T. orientalis. VI. The yellowfin tuna, Thunnus albacares is a single worldwide panmictic species. VII. North Atlantic Scomber scombrus shows a sharp divergence from Pacific S. australasicus and the wide-spread anti-tropical S. japonicus, supporting recognition of two subgenera, Scomber for S, scombrus, and Pneumatophorus for the other species. VIII. Differentiation of chub mackerel supports recognition of two species, Scomber colias in the Atlantic and S. japonicus in the Indo-Pacific. IX. Nuclear and mitochondrial DNA confirms monophyly of the Scomberomorus regalis group of Spanish mackerels but produces a slightly different phylogeny than does morphological data. C1 Natl Marine Fisheries Serv, Systemat Lab, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Collette, BB (reprint author), Natl Marine Fisheries Serv, Systemat Lab, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 25 TC 25 Z9 27 U1 2 U2 5 PU SOCIETE FRANCAISE ICHTYOLOGIE PI PARIS PA 43 RUE CUVIER, 75231 PARIS, CEDEX 05, FRANCE BN 2-9507330-5-0 PY 1999 BP 149 EP 164 PG 16 WC Ecology; Fisheries; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Fisheries; Marine & Freshwater Biology GA BP33Q UT WOS:000084731300016 ER PT B AU Dunkers, JP Zimba, CG Phelan, FR Parnas, RS Fujimoto, J AF Dunkers, JP Zimba, CG Phelan, FR Parnas, RS Fujimoto, J BE Newaz, GM Gibson, RF TI Real structure determination for permeability prediction SO PROCEEDINGS OF THE EIGHTH JAPAN-U.S. CONFERENCE ON COMPOSITE MATERIALS LA English DT Proceedings Paper CT 8th Japan-US Conference on Composite Materials CY SEP 24-25, 1998 CL BALTIMORE, MD SP Wayne St Univ, Amer Soc Composites, Japan Soc Composite Mat ID FIBROUS POROUS-MEDIA; TRANSVERSE FLOW; MICROSCALE FLOW AB The determination of reinforcement permeability is crucial for the rational design of liquid molding processes. Many permeability measurements have been conducted on a variety of fabrics but such measurements are difficult and time consuming. Optical coherence tomography (OCT), a new nondestructive imaging technique, provides the real fabric architecture for permeability prediction. Critical to the engineering success of this work is the rapidity and cost of the technique. Our early work demonstrates that images can be obtained rapidly, the images can be processed automatically to provide the 3-D fabric structure, and the fabric permeability can be computed with reasonable accuracy. The work will also explore the optical constraints of the current OCT technology and discuss ongoing research for further increasing the usefulness of OCT for permeability prediction, damage initiation, and other structure- property determinations. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Dunkers, JP (reprint author), Natl Inst Stand & Technol, Div Polymers, Bldg 224-B-108, Gaithersburg, MD 20899 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA BN 1-56676-718-0 PY 1999 BP 115 EP 121 PG 7 WC Materials Science, Composites SC Materials Science GA BP30Z UT WOS:000084658600012 ER PT B AU Dunkers, JP Phelan, FR Zimba, CG Flynn, KM Peterson, RC Lie, XD Fujimoto, JG Parnas, RS AF Dunkers, JP Phelan, FR Zimba, CG Flynn, KM Peterson, RC Lie, XD Fujimoto, JG Parnas, RS GP ACMC TI Flow prediction in real structures using optical coherence tomography and lattice Boltzmann mathematics SO PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON FLOW PROCESSES IN COMPOSITE MATERIALS LA English DT Proceedings Paper CT 5th International Conference on Flow Processes in Composite Materials CY JUL 12-14, 1999 CL UNIV PLYMOUTH, PLYMOUTH, ENGLAND SP Univ Plymouth, Adv Composites Mfg Ctr HO UNIV PLYMOUTH ID FIBROUS POROUS-MEDIA; PERMEABILITY; COMPOSITES; LIQUID AB The permeability tensor is a critical design parameter for liquid composite molding. Efforts over the past several years have demonstrated the difficulties in permeability measurement and multi-phase flow behavior. Microflow simulations based on lattice-Boltzmann methods have shown that the permeability and the unsaturated flow behavior can be estimated if the porous structure of the material can be characterized, but existing characterization methods are either too slow and difficult, have insufficient resolution, or are extremely expensive with limited availability. Optical coherence tomography can in many cases provide images with a spatial resolution of 15 microns, acquired nondestructively in less than one minute, for a cost near $60,000. The important issues of sample refractive index and image processing will be discussed to illustrate the limitations of this imaging technique. Predictions of permeability, images of damage accumulation, and the distributions of short fibers in a thermoplastic matrix will illustrate the potential of the technique. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Dunkers, JP (reprint author), NIST, Div Polymers, Stop 8543, Gaithersburg, MD 20899 USA. NR 24 TC 3 Z9 3 U1 0 U2 1 PU ADVANCED COMPOSITES MANUFACTURING CENTRE PI PLYMOUTH PA SCH ENGINEERING, UNIV PLYMOUTH, PLYMOUTH PL4 8AA, ENGLAND BN 1-870918-01-0 PY 1999 BP 291 EP 302 PG 12 WC Materials Science, Composites SC Materials Science GA BY44Y UT WOS:000189296200031 ER PT B AU Koning, R Dixson, R Fu, J Tsai, VW Renegar, TB Vorburger, T AF Koning, R Dixson, R Fu, J Tsai, VW Renegar, TB Vorburger, T BE Tan, J TI Improving step height and pitch measurements using the calibrated atomic force microscope SO PROCEEDINGS OF THE FIRST INTERNATIONAL SYMPOSIUM ON INSTRUMENTATION SCIENCE AND TECHNOLOGY LA English DT Proceedings Paper CT 1st International Symposium on Instrumentation Science and Technology CY AUG 23-26, 1999 CL LUOYANG, PEOPLES R CHINA SP Natl Nat Sci Fdn China, Chinese Soc Measurement, Comm Instrumentat, Int Comm Measurements & Instrumentat, Harbin Inst Technol, Hefei Univ Technol, Luoyang Inst Technol C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Koning, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU CHINA METROLOGY PRESS PI BEIJING PA HE PING LI XI JIE JIA 2 HAO, BEIJING 100012, PEOPLES R CHINA BN 7-5026-1221-1 PY 1999 BP 548 EP 555 PG 8 WC Instruments & Instrumentation SC Instruments & Instrumentation GA BP39J UT WOS:000084980800101 ER PT B AU Schmitz, TL Ziegert, JC AF Schmitz, TL Ziegert, JC GP ASPE ASPE ASPE TI The implementation of simultaneous trilateration to measure dynamic three-dimensional contours using the laser ball bar SO PROCEEDINGS OF THE FOURTEENTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 14th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 31-NOV 05, 1999 CL MONTEREY, CA SP Amer Soc Precis Engn, Elsevier Sci Inc, European Soc Precis Engn & Nanotechnol, Japan Soc Precis Engn ID MACHINE-TOOL METROLOGY C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Schmitz, TL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-22-4 PY 1999 BP 29 EP 32 PG 4 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BS05K UT WOS:000168480400004 ER PT B AU Phillips, SD AF Phillips, SD GP ASPE ASPE ASPE TI A general quantitative method to validate instrument calibration techniques SO PROCEEDINGS OF THE FOURTEENTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Proceedings Paper CT 14th Annual Meeting of the American-Society-for-Precision-Engineering CY OCT 31-NOV 05, 1999 CL MONTEREY, CA SP Amer Soc Precis Engn, Elsevier Sci Inc, European Soc Precis Engn & Nanotechnol, Japan Soc Precis Engn C1 NIST, Gaithersburg, MD 20899 USA. RP Phillips, SD (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC PRECISION ENGINEERING PI RALEIGH PA 401 OBERLIN RD, SUITE 108, PO BOX 10826, RALEIGH, NC 27605-0826 USA BN 1-887706-22-4 PY 1999 BP 525 EP 528 PG 4 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BS05K UT WOS:000168480400126 ER PT B AU Georges, TM Harlan, JA AF Georges, TM Harlan, JA BE Anderson, SP Terray, EA White, JAR Williams, AJ TI The case for building a current-mapping over-the-horizon radar SO PROCEEDINGS OF THE IEEE SIXTH WORKING CONFERENCE ON CURRENT MEASUREMENT LA English DT Proceedings Paper CT IEEE 6th Working Conference on Current Measurement CY MAR 11-13, 1999 CL SAN DIEGO, CA SP IEEE ID SURFACE CURRENTS AB Results of recent NOAA tests with the U.S. Air Force and U.S. Navy over-the-horizon (OTH) radars show that it is possible to map near-surface currents with 10-15-km resolution to ranges greater than 2,500 km. The technique is similar to that used by commercially available high-frequency current-mapping radars, except that range is greatly extended by bouncing the radar beam off the ionosphere. Current maps made with U.S. Navy OTH radars often show new detail never before seen, for example, the complex space-time structure of the Florida Current, as well as large currents driven ahead of an Atlantic hurricane. However, the military taskloads of these radars preclude their operational use for continuous, large-area ocean monitoring. For that purpose, a dedicated low-cost radar system would be required. A possible installation would cover the Gulf of Mexico, the Caribbean Sea, and the hurricane approaches to the U.S. Fast Coast and Gulf Coast. We examine the costs, benefits, problems, and potential customers of such a radar. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Georges, TM (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 13 TC 0 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5505-9 PY 1999 BP 14 EP 18 DI 10.1109/CCM.1999.755206 PG 5 WC Engineering, Marine; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BM69M UT WOS:000079487900003 ER PT B AU Shih, HH Sprenke, JJ AF Shih, HH Sprenke, JJ BE Anderson, SP Terray, EA White, JAR Williams, AJ TI A GPS-tacked surface drifter for harbor and estuary applications SO PROCEEDINGS OF THE IEEE SIXTH WORKING CONFERENCE ON CURRENT MEASUREMENT LA English DT Meeting Abstract CT IEEE 6th Working Conference on Current Measurement CY MAR 11-13, 1999 CL SAN DIEGO, CA SP IEEE C1 NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Shih, HH (reprint author), NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5505-9 PY 1999 BP 93 EP 94 DI 10.1109/CCM.1999.755221 PG 2 WC Engineering, Marine; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BM69M UT WOS:000079487900019 ER PT B AU Miller, GS Saylor, JH McCormick, MJ AF Miller, GS Saylor, JH McCormick, MJ BE Anderson, SP Terray, EA White, JAR Williams, AJ TI Detecting storm-generated suspended materials in Lake Michigan using ADCP echo intensities SO PROCEEDINGS OF THE IEEE SIXTH WORKING CONFERENCE ON CURRENT MEASUREMENT LA English DT Proceedings Paper CT IEEE 6th Working Conference on Current Measurement CY MAR 11-13, 1999 CL SAN DIEGO, CA SP IEEE ID SOUTHERN AB Data from Acoustic Doppler Current Profilers deployed in the nearshore region of southeastern Lake Michigan provide evidence of sediment resuspension episodes and cross-shelf flux of materials during strong winter storms. Significant increases (+20 dB) in echo intensity and current velocities correlate well with satellite imagery of a sediment-laden plume transporting material in a cyclonic Bow around the lake basinis perimeter. A decrease in echo intensity to near-background levels following resuspension events suggests that the larger particles settle out, leaving the very fine material that remains visible in satellite imagery for many days. Although there were no concurrent Total Suspended Material measurements during the event, the ADCP results suggest that resuspension events and plume movements can be detected. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Miller, GS (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5505-9 PY 1999 BP 264 EP 268 DI 10.1109/CCM.1999.755252 PG 5 WC Engineering, Marine; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BM69M UT WOS:000079487900052 ER PT S AU Shirley, EL Benedict, LX Bohn, RB AF Shirley, EL Benedict, LX Bohn, RB BE Struck, CW Mishra, KC DiBartolo, B TI Theory of optical absorption with electron-hole attraction SO PROCEEDINGS OF THE SEVENTH INTERNATIONAL SYMPOSIUM ON PHYSICS AND CHEMISTRY OF LUMINESCENT MATERIALS SE Electrochemical Society Series LA English DT Proceedings Paper CT 7th International Symposium on the Physics and Chemistry of Luminescent Materials of the Electrochemical-Society CY NOV 01-06, 1998 CL BOSTON, MA SP Electrochem Soc, Luminescence & Display Mat Div ID PARTICLE BAND-STRUCTURE; DIELECTRIC FUNCTION; CORE POLARIZATION; BASIS-SETS; SEMICONDUCTORS; INSULATORS; ENERGIES; GAAS; BULK; GAP AB This work presents calculations of the optical absorption spectra of semiconductors and insulators. The background and underlying physics are discussed, and the efficient computational method used is fetched. Results for eight solids are presented and compared to measured spectra, along with computed x-ray absorption spectra neat several edges. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 43 TC 2 Z9 2 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA SN 0275-0171 BN 1-56677-218-4 J9 ELEC SOC S PY 1999 VL 98 IS 24 BP 36 EP 48 PG 13 WC Chemistry, Physical; Electrochemistry; Materials Science, Coatings & Films; Optics; Physics, Atomic, Molecular & Chemical SC Chemistry; Electrochemistry; Materials Science; Optics; Physics GA BM63H UT WOS:000079309100003 ER PT S AU Zhang, NF AF Zhang, NF BE Yallup, K Narasimhan, MK TI Statistical control for autocorrelated data SO PROCESS AND EQUIPMENT CONTROL IN MICROELECTRONIC MANUFACTURING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Process and Equipment Control in Microelectronic Manufacturing CY MAY 19-20, 1999 CL EDINBURGH, SCOTLAND SP European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate gen Sci Res & Dev, Scottish Enterprise, Sira Technol Ctr, UK, Institut Elect Engineers, UK DE average run length; exponentially weighted moving average; process mean shift; statistical process control ID STATIONARY PROCESS DATA; CONTROL CHART; SERIAL CORRELATION; CUSUM TESTS; PERFORMANCE AB Recently, statistical process control (SPC) methodologies have been developed to accommodate autocorrelated data. A primary method to deal with autocorrelated data is the use of residual charts. Although this methodology has the advantage that it can be applied to any autocorrelated data, it needs modeling effort in practice. In addition, the detection capability of the residual chart is not always great. Zhang(1) proposed the EWMAST chart, which is constructed by charting the EWMA statistic for stationary processes to monitor the process mean. The performance among the EWMAST chart, the X chart, the residual X chart and other charts were compared in Zhang(1). In this article, I will compare the EWMAST chart with the residual CUSUM chart and residual EWMA chart as well as the residual X chart and X chart via the average run length. C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Zhang, NF (reprint author), Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3222-9 J9 P SOC PHOTO-OPT INS PY 1999 VL 3742 BP 65 EP 70 DI 10.1117/12.346251 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BN20G UT WOS:000081060900007 ER PT J AU Macek, A AF Macek, A TI Research on combustion of black-liquor drops SO PROGRESS IN ENERGY AND COMBUSTION SCIENCE LA English DT Review DE combustion; droplets; kraft liquors; pyrolysis; recovery boilers; research; volatilization ID FUME PARTICLE-SIZE; RECOVERY BOILER; CHAR; TEMPERATURE; PYROLYSIS; NOZZLES; DENSITY AB Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practiced for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) reexamines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. Published by Elsevier Science Ltd. C1 NIST, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Macek, A (reprint author), NIST, Proc Measurements Div, Gaithersburg, MD 20899 USA. NR 59 TC 14 Z9 15 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-1285 J9 PROG ENERG COMBUST JI Prog. Energy Combust. Sci. PY 1999 VL 25 IS 3 BP 275 EP 304 DI 10.1016/S0360-1285(98)00027-6 PG 30 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 209UK UT WOS:000081067100003 ER PT J AU Orsi, AH Johnson, GC Bullister, JL AF Orsi, AH Johnson, GC Bullister, JL TI Circulation, mixing, and production of Antarctic Bottom Water SO PROGRESS IN OCEANOGRAPHY LA English DT Review ID WEDDELL-SCOTIA CONFLUENCE; WESTERN SOUTH-ATLANTIC; DEEP-WATER; DRAKE PASSAGE; HYDROGRAPHIC SECTION; CIRCUMPOLAR CURRENT; INDIAN-OCEAN; SOUTHWESTERN ATLANTIC; NORWEGIAN-GREENLAND; MAUD RISE AB The Antarctic source of bottom water to the abyssal layer of the World Ocean is examined, as well as its large-scale flow pattern and ultimate entrainment rate into the deep water above. We make use of the available high-quality station data in the Southern Ocean to construct bottom maps of neutral density and mean property maps, including Chlorofluorocarbon (CFC), for the abyssal layer underneath a selected neutral density surface. The maximum density at the sill depth of Drake Passage is used to distinguish between the voluminous deep water mass that is a continuous component of the Antarctic Circumpolar Current from the relatively denser bottom water originated along the Antarctic continental margins. Based on water density, Antarctic Bottom Water (AABW) is defined here generically to include all volumes of non-circumpolar water of Antarctic origin. Over the shelf regime multiple localized sources of specific AABW types contribute to the abyssal layer of the adjacent Antarctic basins. Characteristics of these dense bottom waters reflect closely those observed on the parent Shelf Water mass. Spreading paths of newly-formed deep and bottom waters over the slope regime, and their subsequent oceanic circulation patterns are analyzed on the basis of global property maps for the AABW layer. Interior mixing and interbasin exchanges of AABW are deduced from mean characteristic curves following the southern streamline of the Antarctic Circumpolar Current. Outflow and mixing of AABW from the Weddell Sea to the Argentine Basin is depicted using density and CFC distributions of two zonal hydrographic lines. Recirculation and mixing of deep and bottom waters within the Weddell Gyre are also detailed using a meridional section along the Greenwich Meridian. The strength of all localized sources of AABW combined is estimated by two independent approaches. An estimate of the total production rate of AABW is calculated based on the oceanic CFC budget for the AABW layer offshore of the 2500-m isobath. The sum of all downslope inputs of well-ventilated bottom water types underneath the top isopycnal must account for the measured CFC content in the bottom layer. The resulting total AABW production rate is about 8 Sv, which is a conservative figure that neglects the loss of CFC-bearing waters across the top isopycnal in recent years, whereas about 9.5 Sv is calculated assuming a well-mixed bottom layer. Making use of their transient nature, CFC distributions at the top of the AABW layer indicate that more direct and rapid entrainment of CFC-rich bottom waters below occurs over localized areas with relatively strong upwelling rates and enhanced vertical mixing. A second, more ad-hoc but independent oceanic mass budget of the bottom layer is also constructed. A typical basin-wide rate of deep upwelling of 3 x 10(-7) m s(-1) requires 10 Sv (1 Sv = 10(6) m(3) s(-1)) of newly-formed AABW to sink down the slope around Antarctica. We have also formulated a spatial distribution of deep upwelling on the isopycnal at the top of the AABW. It is expressed as a combination of wind, topographic, and turbulent components, which in turn are functions of the isopycnal depth, bottom depth, and bottom layer thickness. This non-uniform upwelling field yields about 12 Sv of AABW exported across the top isopycnal. Fortuitously, the overall average of upward speed at the top isopycnal (3.7 x 10(-7) m s(-1)) compares well with previous estimates of deep upwelling in the northern basins. A series of likely sites for strong vertical entrainment of AABW are clearly identified in the modeled distribution of deep upwelling, consonant with the observed CFC distributions on the top isopycnal. Altogether, regions with relatively high upwelling rates (> 5 x 10(-7) m s(-1)) occupy only a quarter of the total areal extent of the top isopycnal, but they account for as much as 45% of the total vertical transport. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98125 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Orsi, AH (reprint author), Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98125 USA. EM aorsi@tamu.edu RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 101 TC 475 Z9 483 U1 6 U2 84 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1999 VL 43 IS 1 BP 55 EP 109 DI 10.1016/S0079-6611(99)00004-X PG 55 WC Oceanography SC Oceanography GA 210WC UT WOS:000081126800002 ER PT J AU Brodeur, R McKinnell, S Nagasawa, K Pearcy, W Radchenko, V Takagi, S AF Brodeur, R McKinnell, S Nagasawa, K Pearcy, W Radchenko, V Takagi, S TI Epipelagic nekton of the North Pacific Subarctic and Transition Zones SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Science Board Symposium, at the 6th Annual Meeting of the North-Pacific-Marine-Science-Organization CY OCT 24, 1997 CL PUSAN, SOUTH KOREA SP N Pacific Marine Sci Org ID SUB-ARCTIC PACIFIC; SALMON ONCORHYNCHUS; PSEUDOPENTACEROS-WHEELERI; PINK-SALMON; BERING SEA; OCEAN; CLIMATE; ASSOCIATIONS; ENVIRONMENT; ORDINATION AB During the 1980s and 1990s, scientific research cruises and commercial gillnet operations with scientific observers aboard were conducted throughout much of the Subarctic and Transition Zones of the North Pacific Ocean, These studies produced one of the most extensive databases ever collected on the relative species composition and trophic structure of epipelagic nekton of the Subarctic and Transition Zones in the North Pacific Ocean. Data from Japanese high-seas gillnet research surveys (1981-1991) were examined using multivariate analytical techniques to analyse community structure of nektonic cephalopods, elasmobranchs, and teleosts in the North Pacific Subarctic and Transition Zones during the summer months, emphasizing differences between the eastern and western Subarctic Gyres, Species diversity generally increased going from west to east, which was apparently associated with the greater range of temperatures in the east. Discriminant analysis was able to correctly classify about half the catch locations into their respective regions. Catches from multinational drift gillnet commercial fisheries operations in 1990-1991 mainly in the Transition Zone were also examined, Classification techniques were employed to determine species associations and multivariate analyses were used to examine relationships of these assemblages to environmental data. We found that some species are often captured in the same gillnet sets and form species associations that are distinct in ordination space, but these associations are loose and map vary appreciably from year to year, We review recent studies on the feeding habits and daily ration of the dominant species and construct food webs for the eastern and western Subarctic and Transition Zone systems emphasizing the role that nekton play in these pelagic ecosystems. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 NMFS, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. DFO, Pacific Biol Stn, Nanaimo, BC V9R 5K6, Canada. Natl Res Inst Far Seas Fisheries, Shimizu, Shizuoka 424, Japan. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. TINRO Ctr, Pacific Sci Res Fisheries Ctr, Vladivostok 690600, Russia. Hokkaido Univ, Fac Fisheries, Hakodate, Hokkaido 041, Japan. RP Brodeur, R (reprint author), NMFS, NW Fisheries Sci Ctr, Newport, OR 97365 USA. NR 77 TC 31 Z9 32 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1999 VL 43 IS 2-4 BP 365 EP 397 DI 10.1016/S0079-6611(99)00013-0 PG 33 WC Oceanography SC Oceanography GA 222ZA UT WOS:000081814200009 ER PT J AU Beamish, RJ Leask, KD Ivanov, OA Balanov, AA Orlov, AM Sinclair, B AF Beamish, RJ Leask, KD Ivanov, OA Balanov, AA Orlov, AM Sinclair, B TI The ecology, distribution, and abundance of midwater fishes of the Subarctic Pacific gyres SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Science Board Symposium, at the 6th Annual Meeting of the North-Pacific-Marine-Science-Organization CY OCT 24, 1997 CL PUSAN, SOUTH KOREA SP N Pacific Marine Sci Org ID VERTICAL-DISTRIBUTION; SALMON; MIGRATION; OREGON; SEA AB We describe the distribution and abundance of the midwater fish community, between 200 m and 500 m, in the North Pacific. The main area of interest was the Subarctic Pacific gyres, but we include species from the Bering Sea and the Sea of Okhotsk. There were 196 species identified in each gyre, 38 of which were common to both gyres, The most abundant species belong to the family Myctophidae and the most ecologically important myctophid probably is Stenobrachius leucopsarus. This species could have a biomass of approximately 21 million tonnes (t) in the Subarctic Pacific (including the Bering Sea and Sea of Okhotsk). S. leucopsarus is a small (about 8 cm maximum length) fish that lives up to 7 years. It is prey for a variety of other fishes, birds and mammals and may migrate into the mixing layer each evening where it feeds mainly on euphausiids and copepods. The total abundance of midwater fishes appears to be large relative to total catches of other fish in the same areas. The vertical migratory behaviour of some of the residents provides a mechanism to transfer production out of the mixing layer. The movement into the surface layer by some fishes at night indicates that dynamic changes occur in the midwater community between the day and night, and the ecosystem dynamics in the surface layer are different in the day and in the night. This behaviour and the huge biomass relative to commercial species means that the dynamics of fish communities in the Subarctic Pacific are complex and need to be studied over a 24 hour period, The large biomasses may eventually attract commercial interest, thus it is important to establish international, cooperative programs now to learn more about the dynamics of these populations and the relationships with other species. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Pacific Biol Stn, Dept Fisheries & Oceans, Nanaimo, BC, Canada. TINRO, Pacific Res Fisheries Ctr, Vladivostok, Russia. RAS, Inst Marine Biol, Vladivostok, Russia. Russian Fed Res Inst Fisheries & Oceanog, Moscow, Russia. Alaska Fisheries Sci Ctr, Seattle, WA USA. RP Beamish, RJ (reprint author), Pacific Biol Stn, Dept Fisheries & Oceans, Nanaimo, BC, Canada. RI Balanov, Andrey/I-8673-2012; Orlov, Alexei/E-2036-2012 OI Orlov, Alexei/0000-0002-0877-2553 NR 135 TC 66 Z9 69 U1 5 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1999 VL 43 IS 2-4 BP 399 EP 442 DI 10.1016/S0079-6611(99)00017-8 PG 44 WC Oceanography SC Oceanography GA 222ZA UT WOS:000081814200010 ER PT J AU Di Marzio, EA AF Di Marzio, EA TI The ten classes of polymeric phase transitions: their use as models for self-assembly SO PROGRESS IN POLYMER SCIENCE LA English DT Review DE polymer phase transitions; the ten polymer phase transitions; biological self-assembly; biopolymers; structure inducing phase transitions ID DILUTE-SOLUTION THEORY; RODLIKE PARTICLES; STATISTICAL THERMODYNAMICS; LIQUID-CRYSTALS; EQUILIBRIUM POLYMERIZATION; TRIBLOCK COPOLYMERS; LATTICE STATISTICS; DIRECT ENUMERATION; FLEXIBLE POLYMERS; EXCLUDED VOLUME AB A brief overview of the ten classes of polymer phase transitions is given. In each case the basic physics underlying the transition is given. Special attention is devoted to the polymer threading a membrane transition (PTM) since it allows us to understand the reason for the occurrence of the five classes of transition unique to the isolated polymer molecule. They are the PTM transition; the helix to random coil transition; adsorption; equilibrium polymerization/one-dimensional crystallization; the collapse transition. The five classes of transitions of interacting polymers are liquid crystals/plastic crystals; glasses; crystals; liquid-liquid polymer transitions; soaps-block copolymers/membranes-micelles-vesicles. A classification is made of the coupling of these transitions to one another in pairs, triplets, etc, and it is observed that the number of kinds of such transitions is in the thousands. Because of the five transitions unique to polymers it is argued that the class of materials richest in the occurrence of phase transitions are polymers. Self-assembly is viewed essentially as materials undergoing phase transitions. It is evident that of all materials, polymers express self-assembly in fullest measure. A classification scheme is given for self-assembled structures both in biology and as a technology opportunity. The paradigm developed in this paper enriches polymer science by revealing the existence of a large number of problems awaiting solution. This paradigm also provides a route towards understanding biological self-assembly. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Di Marzio, EA (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 170 TC 41 Z9 41 U1 4 U2 38 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6700 J9 PROG POLYM SCI JI Prog. Polym. Sci. PY 1999 VL 24 IS 3 BP 329 EP 377 DI 10.1016/S0079-6700(99)00008-8 PG 49 WC Polymer Science SC Polymer Science GA 212UQ UT WOS:000081236300001 ER PT S AU Hendricks, JH Aquino, MI Zachariah, MR AF Hendricks, JH Aquino, MI Zachariah, MR BE Johnson, RN Lee, WY Pickering, MA Sheldon, BW TI A new low temperature chemical vapor deposition technique for growing thin films of Ti, TiN on copper and TiO2, TixSiy on silicon SO PROPERTIES AND PROCESSING OF VAPOR-DEPOSITED COATINGS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Properties and Processing of Vapor-Deposited Coatings, at the 1998 MRS Fall Meeting CY NOV 30-DEC 02, 1998 CL BOSTON, MA SP Mat Res Soc ID TITANIUM AB In this paper, we present a process which has the benefits of operating at lower temperatures than conventional CVD, that uses low cost precursors, and produces only environmentally benign byproducts. This new method for depositing Ti, TiN, TiO2, and TixSiy thin films has been demonstrated using a coftow diffusion reactor to react Na metal vapor with TiCl4 as described by the following equation: 4Na(g) + TiCl4(g) ---(Ar)---> Ti(s)+ 4NaCl(g). In this reaction, sodium strips chlorine from titanium tetrachloride freeing titanium metal to grow into a thin film on a substrate placed in the reaction zone. TiN and TiO2 films were produced by the introduction of N-2 gas or O-2 gas into the reactor, respectively. Using this reaction chemistry, we have produced Ti and TiN thin films on Cu substrates at 610 degrees C (considerably lower than the 900 degrees C to 1200 degrees C required for conventional thermal CVD of titanium) and TiO2 and titanium silicides (TixSiy) films on silicon substrates. Thermodynamics calculations indicated that this class of chemistry is generic and that a wide range of metals and ceramics could be grown, and preliminary experiments do suggest that TiC and SiC thin films can be gown using this process. The thin films were primarily analyzed by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and Raman Spectroscopy. C1 Natl Inst Stand & Technol, Process Measurements Div, Gaithersburg, MD 20899 USA. RP Zachariah, MR (reprint author), Natl Inst Stand & Technol, Process Measurements Div, Gaithersburg, MD 20899 USA. NR 16 TC 0 Z9 0 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-461-0 J9 MATER RES SOC SYMP P PY 1999 VL 555 BP 203 EP 208 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BN11Q UT WOS:000080757900029 ER PT J AU Trylska, J Antosiewicz, J Geller, M Hodge, CN Klabe, RM Head, MS Gilson, MK AF Trylska, J Antosiewicz, J Geller, M Hodge, CN Klabe, RM Head, MS Gilson, MK TI Thermodynamic linkage between the binding of protons and inhibitors to HIV-1 protease SO PROTEIN SCIENCE LA English DT Article DE binding; cyclic urea; HIV-1 protease; inhibitor; pK(alpha) ID IMMUNODEFICIENCY-VIRUS PROTEASE; MOLECULAR-DYNAMICS SIMULATION; CATALYTIC ASPARTYL GROUPS; MULTIPLE-SITE TITRATION; ACTIVE-SITE; IONIZABLE GROUPS; ESCHERICHIA-COLI; PH-DEPENDENCE; CYCLIC UREA; ELECTROSTATIC CALCULATIONS AB The aspartyl dyad of free HIV-1 protease has apparent pK(a)s of similar to 3 and similar to 6, but recent NMR studies indicate that the aspartyl dyad is fixed in the doubly protonated form over a wide pH range when cyclic urea inhibitors are bound, and in the monoprotonated form when the inhibitor KNI-272 is bound. We present computations and measurements related to these changes in protonation and to the thermodynamic linkage between protonation and inhibition. The Poisson-Boltzmann model of electrostatics is used to compute the apparent pK(a)s of the aspartyl dyad in the free enzyme and in complexes with four different inhibitors. The calculations are done with two parameter sets. One assigns epsilon = 4 to the solute interior and uses a detailed model of ionization; the other uses epsilon = 20 for the solute interior and a simplified representation of ionization. For the free enzyme, both parameter sets agree well with previously measured apparent pK(alpha)s of similar to 3 and similar to 6. However, the calculations with an internal dielectric constant of 4 reproduce the large pK(a) shifts upon binding of inhibitors, but the calculations with an internal dielectric constant of 20 do not. This observation has implications for the accurate calculation of pK(a)s in complex protein environments. Because binding of a cyclic urea inhibitor shifts the pK(a)s of the aspartyl dyad, changing the pH is expected to change its apparent binding affinity. However, we find experimentally that the affinity is independent of pH from 5.5 to 7.0. Possible explanations for this discrepancy are discussed. C1 Univ Warsaw, Dept Biophys, PL-02089 Warsaw, Poland. Dupont Merck Pharmaceut Co, Wilmington, DE 19880 USA. NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Trylska, J (reprint author), Univ Warsaw, Dept Biophys, Zwirky & Wigury 93, PL-02089 Warsaw, Poland. EM joanna@asp.biogeo.uw.edu.pl; gilson@indigo14.carb.nist.gov RI Antosiewicz, Jan/G-1308-2011 FU FIC NIH HHS [TW00768]; NIGMS NIH HHS [GM54053] NR 92 TC 63 Z9 64 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD JAN PY 1999 VL 8 IS 1 BP 180 EP 195 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 155QB UT WOS:000077956900019 PM 10210196 ER PT B AU Wineland, DJ Monroe, C Itano, WM Kielpinski, D King, BE Myatt, CJ Turchette, QA Wood, CS AF Wineland, DJ Monroe, C Itano, WM Kielpinski, D King, BE Myatt, CJ Turchette, QA Wood, CS BE Ono, YA Fujikawa, K TI Quantum computation, spectroscopy of trapped ions, and Schrodinger's cat SO QUANTUM COHERENCE AND DECOHERENCE SE NORTH-HOLLAND DELTA SERIES LA English DT Proceedings Paper CT 6th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology (ISQM-Tokyo 98) CY AUG 24-27, 1998 CL ADV RES LAB, HITACHI LTD, HATOYAMA, JAPAN SP Phys Soc Japan, Japan Soc Appl Phys, Adv Res Lab, Hitachi Ltd HO ADV RES LAB, HITACHI LTD ID FREQUENCY STANDARD; PROJECTION NOISE; STATES; INTERFEROMETER; ENTANGLEMENT AB We summarize efforts at NIST to implement quantum computation using trapped ions, based on a scheme proposed by J.I. Cirac and P. Zoller (Innsbruck University). The use of quantum logic to create entangled states, which can maximize the quantum-limited signal-to-noise ratio in spectroscopy, is discussed. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Wineland, DJ (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-50091-X J9 N-HOLLAND D PY 1999 BP 103 EP 108 DI 10.1016/B978-044450091-5/50024-5 PG 6 WC Physics, Applied SC Physics GA BP93Y UT WOS:000086691300020 ER PT B AU Hall, DS Matthews, MR Wieman, CE Cornell, EA AF Hall, DS Matthews, MR Wieman, CE Cornell, EA BE Ono, YA Fujikawa, K TI Measurements of relative phase and quantum beat note between Bose-Einstein condensates SO QUANTUM COHERENCE AND DECOHERENCE SE NORTH-HOLLAND DELTA SERIES LA English DT Proceedings Paper CT 6th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology (ISQM-Tokyo 98) CY AUG 24-27, 1998 CL ADV RES LAB, HITACHI LTD, HATOYAMA, JAPAN SP Phys Soc Japan, Japan Soc Appl Phys, Adv Res Lab, Hitachi Ltd HO ADV RES LAB, HITACHI LTD ID ATOMS; INTERFERENCE; COHERENCE; TRAP; GAS AB We use a separated-oscillatory-field condensate interferometer to measure the time-evolution of the relative phase in a two-component Bose-Einstein condensate. The two components are created with a particular relative phase in the \F = 2, m(f) = 1] and \F = 1, m(f) = -1] states of Rb-87 by applying a coupling pulse to a condensate in the \1, -1] state. The components subsequently separate spatially due to their mutual repulsion, damp their relative center-of-mass motion, and come into equilibrium after similar to 45 ms. Meanwhile, the relative phase accumulates at similar to 6.8 GHz and is measured with a second coupling pulse. We find that the coherence initially established between the components is preserved despite the motional damping present in this entangled system. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80302 USA. RP Hall, DS (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80302 USA. NR 27 TC 0 Z9 0 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-50091-X J9 N-HOLLAND D PY 1999 BP 123 EP 128 DI 10.1016/B978-044450091-5/50028-2 PG 6 WC Physics, Applied SC Physics GA BP93Y UT WOS:000086691300024 ER PT J AU Compo, GP Kiladis, GN Webster, PJ AF Compo, GP Kiladis, GN Webster, PJ TI The horizontal and vertical structure of east Asian winter monsoon pressure surges SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE cold surges; pressure surges; shelf waves; tropical-extratropical interaction ID WESTERN EQUATORIAL PACIFIC; PLANETARY-SCALE INTERACTIONS; COASTAL-TRAPPED WAVES; COLD SURGES; NORTHERN WINTER; SOUTH CHINA; WIND BURSTS; DECEMBER 1974; OCEAN; OSCILLATION AB East Asian cold-air outbreaks, accompanied by increasing surface pressure ('pressure surges'), are shown to be an important aspect of the subseasonal variability of the winter monsoon system. In this study the statistical linear relationship between pressure surges, tropical convection, and tropospheric circulation is assessed using a ten-year data set (1985/86-1994/95) of the European Centre for Medium-Range Weather Forecasts gridded operational analyses. From spectral analysis the pressure, wind, and temperature fluctuations indicative of strong pressure surges are found to have statistically-significant spectral peaks at submonthly periods (6 to 30 days). Linear regression analysis is used to detail the time evolution of the dominant horizontal and vertical structure of east Asian pressure surges. Surges are shown to relate significantly to circulation anomalies in both the meridional and zonal components of the lower-tropospheric wind. Relationships between east Asian pressure surges in the submonthly band and tropical circulation anomalies are found over the Bay of Bengal, the eastern Indian Ocean, Indonesia, and the western Pacific regions. Submonthly surges over the South China Sea are related to strong surges and convective activity south of Indonesia, over the South China Sea, the eastern Indian Ocean, and the Philippine regions. Surge-enhanced convective activity is found to precede an enhancement of the local east Asian Hadley cell. Submonthly surges over the Philippine Sea are related to periods of westerly-wind anomalies and convective activity in the western Pacific. Upper-level wave activity over western Asia precedes submonthly surges. The wave activity amplifies in the region of the Pacific jet stream, and can be traced dispersing equatorward through the region of upper-level westerlies over the eastern tropical Pacific. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Compo, GP (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. OI COMPO, GILBERT/0000-0001-5199-9633 NR 70 TC 84 Z9 92 U1 4 U2 19 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 1999 VL 125 IS 553 BP 29 EP 54 DI 10.1256/smsqj.55302 PN A PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 166CE UT WOS:000078558000002 ER PT J AU Milly, PCD AF Milly, PCD TI Comment on "Antiphasing between rainfall in Africa's Rift Valley and North America's Great Basin" SO QUATERNARY RESEARCH LA English DT Letter C1 NOAA, US Geol Survey, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Milly, PCD (reprint author), NOAA, US Geol Survey, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JAN PY 1999 VL 51 IS 1 BP 104 EP 107 DI 10.1006/qres.1998.2011 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 158WJ UT WOS:000078140200010 ER PT J AU Romanyukha, AA Ignatiev, EA Ivanov, DV Vasilyev, AG AF Romanyukha, AA Ignatiev, EA Ivanov, DV Vasilyev, AG TI The distance effect on the individual exposures evaluated from the Soviet nuclear bomb test at Totskoye test site in 1954 SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID ELECTRON-SPIN-RESONANCE; TOOTH ENAMEL; EPR DOSIMETRY; ESR DOSIMETRY; POPULATION AB The first results of an EPR dose reconstruction with tooth enamel from eyewitnesses of the nuclear test at Totskoye, Southern Urals, Russia, are presented. This test was performed on 14 September 1954, when a nuclear device was detonated at a height of 350 m. The declared power of the explosion was 40 kt. Ten radiation doses have been reconstructed in the framework of the present study. Six of them were found to be higher than 0.4 Gy. The investigations performed have demonstrated a potential ability of EPR retrospective dosimetry to provide additional independent dose estimation for a population exposed as a result of the Totskoye nuclear test. The doses reconstructed for donors who were closer to the site during the nuclear test turned out to be considerably higher (up to factor of 10) than those for the donors who were further from the explosion site. Therefore, a crucially important factor to be borne in mind in collecting samples is the distance between the donor and the explosion site at the time of the explosion. C1 Russian Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Russian Acad Sci, Inst Plants & Anim Ecol, Ekaterinburg 620219, Russia. RP Romanyukha, AA (reprint author), Russian Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia. RI Ivanov, Denis/J-3235-2013; Vasil'ev, A.G./A-4458-2017 OI Ivanov, Denis/0000-0001-6757-5587; Vasil'ev, A.G./0000-0002-5062-7288 NR 21 TC 8 Z9 8 U1 0 U2 3 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1999 VL 86 IS 1 BP 53 EP 58 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 239ZY UT WOS:000082801900007 ER PT J AU Bohm, J Alberts, WG Swinth, KL Soares, CG McDonald, JC Thompson, IMG Kramer, HM AF Bohm, J Alberts, WG Swinth, KL Soares, CG McDonald, JC Thompson, IMG Kramer, HM TI ISO recommended reference radiations for the calibration and proficiency testing of dosemeters and dose rate meters used in radiation protection SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID ANGULAR-DEPENDENCE FACTORS; EQUIVALENT CONVERSION COEFFICIENTS; AIR KERMA; PHOTON BEAMS; PHANTOMS; ROD AB One of the activities of the International Organization for Standardization (ISO) is the preparation and revision of standards specifying the requirements for photon, beta and neutron reference radiations to be used in radiation protection for the calibration of personal and area dosemeters and for contamination monitors. The reference radiations are also specified for determining the response of the instruments as a function of radiation energy and angle of incidence. Radionuclide sources, X ray facilities, reactors and accelerators are utilised as radiation sources to cover the wide range of radiation types and energies. The standards are intended to be applied by primary and secondary standard dosimetry laboratories, but information contained in the standards is widely applicable. The standards specify, in addition, fundamental requirements for an adequate characterisation of reference radiations and describe calibration procedures. The latter include the specification of phantoms (trunk, arm/leg, finger) for the calibration and type testing of personal dosemeters in terms of the operational quantities proposed by the ICRU. Conversion coefficients are provided for all the reference radiations. The present paper gives background information about the concepts of the calibration procedures, the choice of the reference radiations, and their dosimetry. The main features of the standards are described and illustrated by examples. C1 Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany. Swith Associates, Richland, WA USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Bohm, J (reprint author), Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany. NR 32 TC 23 Z9 24 U1 1 U2 3 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1999 VL 86 IS 2 BP 87 EP 105 PG 19 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 251TD UT WOS:000083460200002 ER PT J AU Klemic, G Shobe, J Sengupta, S Shebell, P Miller, K Carolan, PT Holeman, G Kahnhauser, H Lamperti, P Soares, C Azziz, N Moscovitch, M AF Klemic, G Shobe, J Sengupta, S Shebell, P Miller, K Carolan, PT Holeman, G Kahnhauser, H Lamperti, P Soares, C Azziz, N Moscovitch, M TI State of the art of environmental dosimetry: 11th international intercomparison and proposed performance tests SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 12th International Conference on Solid State Dosimetry CY JUL 05-10, 1998 CL BURGOS, SPAIN SP Bicron Technol, Bubble Technol Ind, Caja Burgos, Comis Interminist Cienc & Tecnolog, Consejo Seguridad Nucl, Direcc Gen Investigacion Cienc & Tecnol, Empressa Nacl Residuos SA, Excmo Ayuntamiento Burgos, Excma Diputac Province Burgos, Landauer Inc, Nucl Technol Publishing, Siemens Environm Syst Ltd, Stillwater Sci LLC, Studsvik Instrument AB AB The eleventh international intercomparison of environmental dosemeters was organised by the Environmental Measurements Laboratory in collaboration with the National Institute of Standards and Technology (NIST) and Brookhaven National Laboratory. One hundred and twenty one participants from 31 countries submitted 174 sets of dosemeters, including thermoluminescence dosemeters (TLDs), film, electrets, and a Geiger-Mueller device. An outdoor field site was used to expose dosemeters to natural radiation for three months, while other dosemeters were exposed to Cs-137 and Am-241 laboratory sources. A pressurised ionisation chamber, operated continuously at the field site, provided an independent measure of the air kerma in the field, and laboratory air kerma values were verified with chambers calibrated by NIST. Results are presented and current issues in environmental dosimetry are highlighted, including the field performance of new hypersensitive TLD materials. Preliminary results are given from a pilot test of a proposed standard from the American National Standards Institute that provides performance test criteria for environmental dosemeters. C1 US DOE, Environm Measurements Lab, New York, NY 10014 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. US Dept Energy, Brookhaven Grp, Upton, NY 11973 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Georgetown Univ, Med Ctr, Washington, DC 20007 USA. RP Klemic, G (reprint author), US DOE, Environm Measurements Lab, 201 Varick St,5th Floor, New York, NY 10014 USA. NR 9 TC 18 Z9 19 U1 0 U2 1 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD, KENT, ENGLAND TN23 1YW SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 1999 VL 85 IS 1-4 BP 201 EP 206 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 225KQ UT WOS:000081959400045 ER PT J AU Zamora, RJ Kropfli, RA AF Zamora, RJ Kropfli, RA TI Atmospheric modulation of microwave backscatter from the ocean surface SO RADIO SCIENCE LA English DT Article AB During a month-long experiment near San Clemente Island, California, the San Clemente Ocean Probing Experiment (SCOPE), unusual radar echoes were observed from an X-band Doppler radar operated by the National Oceanic and Atmospheric Administration Environmental Technology Laboratory from a cliff 573 m above mean sea level. These radar images were often obtained whenever a strong marine inversion was observed below the level of the radar. The unusual characteristics of the specific event analyzed here were the observed wavelength of the periodic pattern, about 2 km, and its lack of movement during the 15-min period during which specific features of the pattern, for example, the "wave" crest, could be identified. Several explanations were considered but rejected because of their conflict with the observations and known characteristics of ocean waves. The simplest explanation consistent with all of the observations was that of microwave propagation through a marine inversion which was supporting a low-amplitude standing wave in the lee of the island. The plausibility of this hypothesis was supported by a simple ray-trace calculation that simulated propagation through an analytical two-dimensional field of modified refractive index that represented the essential characteristics of the observed refractive index profile. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Zamora, RJ (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 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 JAN-FEB PY 1999 VL 34 IS 1 BP 83 EP 92 DI 10.1029/98RS02429 PG 10 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 161QG UT WOS:000078299800007 ER PT J AU Halket, JM Przyborowska, A Stein, SE Mallard, WG Down, S Chalmers, RA AF Halket, JM Przyborowska, A Stein, SE Mallard, WG Down, S Chalmers, RA TI Deconvolution gas chromatography mass spectrometry of urinary organic acids - Potential for pattern recognition and automated identification of metabolic disorders SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article; Proceedings Paper CT 23rd Annual Meeting of the British-Mass-Spectrometry-Society CY SEP 13-16, 1998 CL UNIV WARWICK, COVENTRY, ENGLAND SP British Mass Spectrometry Soc HO UNIV WARWICK AB The National Institute of Standards and Technology (NIST) Automated Mass Spectral Deconvolution and Identification System (AMDIS) is applied to a selection of data files obtained from the gas chromatography/ mass spectrometry (GC/MS) analysis of urinary organic acids. Mass spectra obtained after deconvolution are compared with a special user library containing both the mass spectra and retention indices of ethoxime-trimethylsilyl (EO-TMS) derivatives of a set of organic acids. Efficient identification of components is achieved and the potential of the procedure for automated diagnosis of inborn errors of metabolism and for related research is demonstrated. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Univ London Royal Holloway & Bedford New Coll, Ctr Chem Sci, Specialist Bioanalyt Serv, Egham TW20 0EX, Surrey, England. Univ London Royal Holloway & Bedford New Coll, Dept Comp Sci, Egham TW20 0EX, Surrey, England. Charing Cross Hosp, Univ London Imperial Coll Sci Technol & Med, Dept Chem Pathol, London W6 2HS, England. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. HD Sci Ltd, Nottingham NG9 6JF, England. Univ London St Georges Hosp, Sch Med, Dept Child Hlth, Paediat Metab Unit, London SW17 0RE, England. RP Halket, JM (reprint author), Univ London, Royal Holloway & Bedford New Coll, Ctr Chem Sci, Specialist Bioanalyt Serv, Surrey TW20 9LZ, England. OI Mallard, Wm. Gary/0000-0003-2158-5098 NR 4 TC 152 Z9 157 U1 10 U2 29 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 1999 VL 13 IS 4 BP 279 EP 284 DI 10.1002/(SICI)1097-0231(19990228)13:4<279::AID-RCM478>3.0.CO;2-I PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 170FY UT WOS:000078796700016 PM 10097403 ER PT J AU Jurrens, KK AF Jurrens, Kevin K. TI Standards for the rapid prototyping in industry SO RAPID PROTOTYPING JOURNAL LA English DT Article DE rapid prototyping; standards AB This paper proposes that development of formalized standards for the rapid prototyping (RP) industry will help enable the continued growth and further advancement of RP technologies. Appropriate standards can provide common methods for measuring the benefits and limitations of RP, as well as facilitate the transition of current advanced rapid manufacturing capabilities from the research laboratory to commercial products. Results and recommendations from a prior RP industry workshop at the National Institute of Standards and Technology (NIST) in October 1997 form the basis for this discussion paper. This paper was presented as part of the 2nd Internet Conference on Rapid Prototyping to gather additional information and obtain further viewpoints regarding the need for and potential content of standards for the RP industry. An addendum is provided to summarize and analyze the results of the conference discussion. C1 NIST, MEL, Bethesda, MD USA. RP Jurrens, KK (reprint author), NIST, MEL, Bethesda, MD USA. NR 15 TC 25 Z9 25 U1 0 U2 0 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 1355-2546 J9 RAPID PROTOTYPING J JI Rapid Prototyping J. PY 1999 VL 5 IS 4 BP 169 EP 178 DI 10.1108/13552549910295514 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA V50KH UT WOS:000203406700004 ER PT S AU Koning, R Dixson, RG Fu, J Renegar, BT Vorburger, TV Tsai, VW Postek, MT AF Koning, R Dixson, RG Fu, J Renegar, BT Vorburger, TV Tsai, VW Postek, MT BE Podio, FL TI Step height metrology for data storage applications SO RECENT ADVANCES IN METROLOGY, CHARACTERIZATION, AND STANDARDS FOR OPTICAL DIGITAL DATA DISKS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks CY JUL 21-22, 1999 CL DENVER, CO SP SPIE, Informat Technol Lab/Natl Inst Stand & Technol DE compact disc; data versatile disc; atomic force microscopy; data storage; metrology; step height ID ATOMIC-FORCE MICROSCOPE AB The measurement of bump heights and pit depth on compact discs (CD) with atomic force microscopes (AFMs) is quite different from the measurement of step heights on step height calibration standards. Both the bumps and the pits show much larger transition regimes and more structural irregularities. The irregularities disqualify the effective use of pro fire based algorithms, which minimize the influence of any remaining motion deviations of the scan apparatus, to determine the height. Therefore a histogram height algorithm has to be used. The results of the bump height and pit depth measurements varied about 20 nm over the different sample regions. The remaining approximately 30 nm difference between the average of the bump height and pit depth is believed to result from the sample preparation procedure. By itself the large sample variation observed will result in rather large measurement uncertainties for the measurement of the average height and depth of these features, if the averaging does not include a large amount of data taken at many different sample positions. C1 Natl Inst Stand & Technol, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Koning, R (reprint author), Natl Inst Stand & Technol, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3292-X J9 P SOC PHOTO-OPT INS PY 1999 VL 3806 BP 21 EP 29 DI 10.1117/12.371161 PG 9 WC Computer Science, Hardware & Architecture; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Computer Science; Instruments & Instrumentation; Materials Science; Optics GA BP33Y UT WOS:000084757000003 ER PT S AU Rochford, KB Kreger, ST West, J AF Rochford, KB Kreger, ST West, J BE Podio, FL TI Variation in optical disc retardance measurements SO RECENT ADVANCES IN METROLOGY, CHARACTERIZATION, AND STANDARDS FOR OPTICAL DIGITAL DATA DISKS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks CY JUL 21-22, 1999 CL DENVER, CO SP SPIE, Informat Technol Lab/Natl Inst Stand & Technol DE birefringence; metrology; optical disc; polarimetry; retardance AB An intercomparison of optical disc birefringence measurements using commercial instrumentation found in manufacturing settings showed significant measurement variation. We discuss possible sources of variation in these measurements, including changes in disc properties and coherence effects. We describe specific measurement errors related to deviations from circular input polarization in one class of polarimetric instruments. Efforts to mitigate measurement errors, such as the development of calibration artifacts, are discussed. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Rochford, KB (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3292-X J9 P SOC PHOTO-OPT INS PY 1999 VL 3806 BP 36 EP 40 DI 10.1117/12.371163 PG 5 WC Computer Science, Hardware & Architecture; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Computer Science; Instruments & Instrumentation; Materials Science; Optics GA BP33Y UT WOS:000084757000005 ER PT S AU Kramar, JA Jun, JS Penzes, WB Scire, FE Teague, EC Villarrubia, JS AF Kramar, JA Jun, JS Penzes, WB Scire, FE Teague, EC Villarrubia, JS BE Podio, FL TI Grating pitch measurements with the molecular measuring machine SO RECENT ADVANCES IN METROLOGY, CHARACTERIZATION, AND STANDARDS FOR OPTICAL DIGITAL DATA DISKS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks CY JUL 21-22, 1999 CL DENVER, CO SP SPIE, Informat Technol Lab/Natl Inst Stand & Technol DE dimensional metrology; Michelson interferometry; scanning tunneling microscopy AB At the National Institute of Standards and Technology, we are building a metrology instrument caned the Molecular Measuring Machine (M-3) With the goal of performing nanometer-accuracy two-dimensional feature placement measurements over a 50 mm by 50 mm area. The instrument uses a scanning tunneling microscope to probe the surface and an interferometer system to measure the lateral probe movement, both having sub-nanometer resolution. The continuous vertical measurement range is 5 mu m, and up to 2 mm can be covered by stitching overlapping ranges. The instrument includes temperature control with millikelvin stability, an ultra-high vacuum environment with a base pressure below 10(-5) Pa, and seismic and acoustic vibration isolation. Pitch measurements were performed on gratings made by holographic exposure of photoresist and on gratings made by laser-focused atomic deposition of Cr. The line pitch for these gratings ranged from 200 nm to 400 nm with an estimated standard uncertainty of the average pitch of 25 x 10(-6). This fractional uncertainty is derived from an analysis of the sources of uncertainty for a 1 mm point-to-paint measurement, including the effects of alignment, Abbe offset, motion cross-coupling, and temperature variations. These grating pitch measurements are uniquely accomplished on M-3 because of the combination of probe resolution and long-range interferometer-controlled stage. This instrument could uniquely address certain dimensional metrology needs in the data storage industry. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kramar, JA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 6 TC 5 Z9 5 U1 0 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 0-8194-3292-X J9 P SOC PHOTO-OPT INS PY 1999 VL 3806 BP 46 EP 53 DI 10.1117/12.371144 PG 8 WC Computer Science, Hardware & Architecture; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Computer Science; Instruments & Instrumentation; Materials Science; Optics GA BP33Y UT WOS:000084757000007 ER PT S AU L'Hostis, P Byers, F Podio, F Tang, X AF L'Hostis, P Byers, F Podio, F Tang, X BE Podio, FL TI Microscopic image analysis of defect areas in optical disks SO RECENT ADVANCES IN METROLOGY, CHARACTERIZATION, AND STANDARDS FOR OPTICAL DIGITAL DATA DISKS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks CY JUL 21-22, 1999 CL DENVER, CO SP SPIE, Informat Technol Lab/Natl Inst Stand & Technol DE CD; DVD; microscopic defect analysis; microscopic image processing; optical disks measurements; data storage; media defects analysis AB This paper presents techniques developed at the Information Technology Laboratory of the US National Institute of Standards and Technology (NIST / ITL) for enabling microscopic image analysis of optical data storage media such as optical disks. These non-destructive techniques allow investigators to easily locate on the media a pre-existing series of media defects. These techniques can be applied to any type of optical disks including CDs and DVDs. The paper describes the experimental setup and the techniques utilized to achieve localization and registration of media defects. These techniques include data acquisition, computer control, auto focus, image processing, and remote control and observation. An extension of this setup utilizing available graphical programming environments can allow investigators at different locations to share and discuss the information on media defects by use of the Internet. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Tang, X (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3292-X J9 P SOC PHOTO-OPT INS PY 1999 VL 3806 BP 106 EP 112 DI 10.1117/12.371152 PG 7 WC Computer Science, Hardware & Architecture; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Computer Science; Instruments & Instrumentation; Materials Science; Optics GA BP33Y UT WOS:000084757000014 ER PT J AU Lerch, TP Schmerr, LW Sedov, A AF Lerch, TP Schmerr, LW Sedov, A TI Modeling the ultrasonic radiation of a planar transducer through a plane fluid-solid interface SO RESEARCH IN NONDESTRUCTIVE EVALUATION LA English DT Article ID SCATTERING; BEAM; TRANSMISSION; WAVES AB Three types of transducer beam models are developed for obtaining the bulk waves generated by a plane piston transducer radiating through a planar fluid-solid interface. The first type, called the surface integral model, is based on a Rayleigh-Sommerfeld-like integral that requires a two-dimensional surface integral to be evaluated. The second model, called the boundary diffraction wave (BDW) paraxial model, simplifies the two-dimensional integration of the surface integral model to a one-dimensional line integration. The third type of model, called the edge element model, is shown to be a novel way of efficiently evaluating the two-dimensional surface integration of the surface integral model. The limitations of these models for simulating inspections near critical refracted angles and near the interface are discussed. It is shown that the introduction of the paraxial approximation in the BDW model allows that model to be computed with a very large (300-1) speed advantage over the surface integral while retaining the same accuracy in most cases. The edge element model, while having a smaller (5-1) advantage over the direct numerical integration of the surface integral model, retains the accuracy of the surface integral model in cases where the paraxial approximation fails and can be easily generalized to more complex testing situations (focused probes, curved interfaces, etc.). C1 Iowa State Univ, Ctr Nondestruct Evaluat, Ames, IA 50011 USA. Iowa State Univ, Dept Aerosp Engn & Engn Mech, Ames, IA 50011 USA. Lakehead Univ, Dept Engn Mech, Thunder Bay, ON P7B 5E1, Canada. RP Lerch, TP (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 31 TC 4 Z9 4 U1 1 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0934-9847 J9 RES NONDESTRUCT EVAL JI Res. Nondestruct. Eval. PY 1999 VL 11 IS 3 BP 137 EP 163 DI 10.1007/PL00003918 PG 27 WC Materials Science, Characterization & Testing SC Materials Science GA 230LX UT WOS:000082253600002 ER PT J AU Slotwinski, JA AF Slotwinski, JA TI Measurement interpretation and uncertainty resulting from nonlinear ultrasonic wave propagation SO RESEARCH IN NONDESTRUCTIVE EVALUATION LA English DT Article ID TRANSDUCER; GENERATION; RADIATION; FIELD AB Nominally identical ceramic-element ultrasonic transducers, of the type used in the aerospace and metals industries for nondestructive evaluation (NDE), often have variability in the peak pressure of the generated ultrasonic pulses. The generated pressures are also high enough for nonlinear propagation to be present in the water medium, often used as coupling in these types of inspections. In this study, a measurement system for monitoring ultrasonic pulse pressure level and nonlinear propagation in water is presented. Several different industrial NDE measurement applications are examined to quantify the impact of variable pressure and nonlinear propagation with respect to test interpretation and measurement uncertainty. In particular, pulse frequency content, velocity measurements, reference block calibrations, and beam-width measurements are examined. In addition, an experimental demonstration of why nonlinear pulse distortion is not normally observed in practice is presented. C1 NIST, Mfg Engn Lab, Gaithersburg, MD 20899 USA. RP Slotwinski, JA (reprint author), NIST, Mfg Engn Lab, 100 Bureau Dr,Mail Stop 8200, Gaithersburg, MD 20899 USA. NR 25 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0934-9847 J9 RES NONDESTRUCT EVAL JI Res. Nondestruct. Eval. PY 1999 VL 11 IS 4 BP 213 EP 234 PG 22 WC Materials Science, Characterization & Testing SC Materials Science GA 261CF UT WOS:000083989700003 ER PT B AU Powell, LJ AF Powell, LJ GP CHEMICAL SCIENCES ROUNDTABLE CHEMICAL SCIENCES ROUNDTABLE TI Government-industry joint R&D ventures: Bridging the gap between the laboratory and the marketplace SO RESEARCH TEAMS AND PARTNERSHIPS: TRENDS IN THE CHEMICAL SCIENCES: REPORT OF A WORKSHOP LA English DT Proceedings Paper CT 3rd Chemical Sciences Roundtable Workshop CY MAY 02-03, 1999 CL IRVINE, CA C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU NATL ACADEMIES PRESS PI WASHINGTON PA 2101 CONSTITUTION AVE, WASHINGTON, DC 20418 USA BN 0-309-06827-4 PY 1999 BP 114 EP 123 PG 10 WC Chemistry, Multidisciplinary; Management SC Chemistry; Business & Economics GA BX17Y UT WOS:000184541500009 ER PT B AU O'Connor, CR AF O'Connor, CR BE Cecil, G TI Restoration of lost human uses of the environment - Introduction SO RESTORATION OF LOST HUMAN USES OF THE ENVIRONMENT SE SETAC GENERAL PUBLICATIONS SERIES LA English DT Proceedings Paper CT Conference on Restoration of Lost Human Uses of the Environment CY MAY 07-08, 1997 CL WASHINGTON, D.C. SP Amer Bar Assoc, Sect Nat Resources Energy & Environm Law, Amer Forest & Paper Assoc, Amer Petr Inst, Natl Min Assoc, Natl Fish & Wildlife Fdn, Natl Pk Serv, Soc Ecol Restorat, US Dept Commerce, NOAA, US Dept Interior C1 NOAA, Deputy Gen Counsel, Silver Spring, MD 20910 USA. RP O'Connor, CR (reprint author), NOAA, Deputy Gen Counsel, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SETAC PRESS PI PENSACOLA PA 1010 N 12TH AVE, PENSACOLA, FL 32501 USA BN 1-880611-21-X J9 SETAC GEN P PY 1999 BP 1 EP 3 PG 3 WC Environmental Sciences SC Environmental Sciences & Ecology GA BQ22U UT WOS:000087625000001 ER PT B AU McHugh, MJ AF McHugh, MJ BE Cecil, G TI Overview of conference objectives SO RESTORATION OF LOST HUMAN USES OF THE ENVIRONMENT SE SETAC GENERAL PUBLICATIONS SERIES LA English DT Proceedings Paper CT Conference on Restoration of Lost Human Uses of the Environment CY MAY 07-08, 1997 CL WASHINGTON, D.C. SP Amer Bar Assoc, Sect Nat Resources Energy & Environm Law, Amer Forest & Paper Assoc, Amer Petr Inst, Natl Min Assoc, Natl Fish & Wildlife Fdn, Natl Pk Serv, Soc Ecol Restorat, US Dept Commerce, NOAA, US Dept Interior C1 NOAA, HAZMAT, Chicago, IL USA. RP McHugh, MJ (reprint author), NOAA, HAZMAT, Chicago, IL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SETAC PRESS PI PENSACOLA PA 1010 N 12TH AVE, PENSACOLA, FL 32501 USA BN 1-880611-21-X J9 SETAC GEN P PY 1999 BP 19 EP 26 PG 8 WC Environmental Sciences SC Environmental Sciences & Ecology GA BQ22U UT WOS:000087625000003 ER PT B AU Ferraris, CF AF Ferraris, CF BE Cabrera, JG RiveraVillarreal, R TI Measurement of the rheological properties of cement paste: A new approach SO ROLE OF ADMIXTURES IN HIGH PERFORMANCE CONCRETE SE RILEM PROCEEDINGS LA English DT Proceedings Paper CT International Symposium on the Role of Admixtures in High Performance Concrete CY MAR 21-26, 1999 CL MONTERREY, MEXICO SP Cementos Mexicanos SA ID FRESH CONCRETE; BEHAVIOR AB This paper presents a new approach for predicting the rheological properties of concrete from rheological measurements on cement paste and from concrete composition. This approach requires measurement of the cement paste rheology under the same conditions as those experienced in the concrete. It is known that the rheology of concrete is affected by the cement paste content, by contributing to the gap between the aggregates. A parallel plate fluid rheometer was used to simulate the gap between the aggregates. It is demonstrated that the distance between the plates affects the rheological parameters of cement paste. Some preliminary results are presented and discussed. As the mixing procedure affects the values of the rheological parameters of the cement paste, special precautions were taken to mix the paste under the, same conditions as those experienced in the concrete. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ferraris, CF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 19 TC 10 Z9 10 U1 0 U2 4 PU R I L E M PUBLICATIONS PI BAGNEUX PA 157 RUE DES BLAINS, 92220 BAGNEUX, FRANCE BN 2-912143-05-5 J9 RILEM PROC PY 1999 VL 5 BP 333 EP 342 PG 10 WC Construction & Building Technology; Engineering, Civil; Materials Science, Composites SC Construction & Building Technology; Engineering; Materials Science GA BS14F UT WOS:000168821200023 ER PT S AU Sung, LP Mulholland, GW Germer, TA AF Sung, LP Mulholland, GW Germer, TA BE Chen, PTC Gu, ZH Maradudin, AA TI Polarization of light scattered by spheres on a dielectric film SO ROUGH SURFACE SCATTERING AND CONTAMINATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Rough Surface Scattering and Contamination CY JUL 21-23, 1999 CL DENVER, CO SP SPIE DE dielectric films; ellipsometry; polystyrene latex spheres; polarimetry; scattered light ID OUT-OF-PLANE AB Bidirectional ellipsometric measurements were conducted on a model system containing spherical particles on silicon surfaces coated with dielectric polymer films. The principal angle of polarization, eta((P)), and the degree of linear polarization, P-L((p)), of the light scattered into directions out of the plane of incidence were measured using p-polarized, 532 nm light. Results are presented and compared to those from particles on a bare silicon substrate. Spheres of diameter 181 nm and 217 nm and film thicknesses ranging from 55 nm to 140 nm were used to test two theoretical models for light scattering: a Mie-surface double-interaction approximation and a finite-element time-domain implementation of Maxwell's equations. The measurements and the modeling demonstrate the application of bidirectional ellipsometry for characterizing the sizes of particulate contaminates on surfaces. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sung, LP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 17 TC 5 Z9 5 U1 0 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 0-8194-3270-9 J9 P SOC PHOTO-OPT INS PY 1999 VL 3784 BP 296 EP 303 DI 10.1117/12.366712 PG 8 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BN98A UT WOS:000083742000029 ER PT S AU Germer, TA AF Germer, TA BE Chen, PTC Gu, ZH Maradudin, AA TI Multidetector hemispherical polarized optical scattering instrument SO ROUGH SURFACE SCATTERING AND CONTAMINATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Rough Surface Scattering and Contamination CY JUL 21-23, 1999 CL DENVER, CO SP SPIE DE defect detection; instrumentation; optical scatter; polarimetry; surface inspection ID OUT-OF-PLANE; MICROROUGHNESS; POLARIMETRY; ROUGHNESS; SURFACES; DEFECTS AB A multidetector optical scattering instrument is described and characterized, The instrument has twenty-eight detectors surrounding and substantially covering the scattering hemisphere. Each detector contains a polarizer so that each is only sensitive to p-polarized scattered light. The polarization of the incident light is linear and can be rotated into any angle. With this instrument, polarized light scattering measurements can be performed in multiple directions at once. The utility of this instrument is demonstrated by measuring the light scattered from a microrough silicon sample and silicon surfaces containing different sizes of polystyrene latex spheres. The results are compared to the predictions of theoretical calculations. It is shown that the distribution of polarization parameters for each of the different sizes of spheres and for microroughness are different. It is expected that designs similar to the one presented here will allow for improved on-line characterization of defects on smooth surfaces. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Germer, TA (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 19 TC 5 Z9 5 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3270-9 J9 P SOC PHOTO-OPT INS PY 1999 VL 3784 BP 304 EP 313 DI 10.1117/12.366713 PG 10 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BN98A UT WOS:000083742000030 ER PT J AU Landrum, PF Fisher, SW Hwang, H Hickey, J AF Landrum, PF Fisher, SW Hwang, H Hickey, J TI Hazard evaluation of ten organophosphorus insecticides against the midge, Chironomus riparius via QSAR SO SAR AND QSAR IN ENVIRONMENTAL RESEARCH LA English DT Article DE organophosphate insecticides; midges; molecular connectivity; QSAR ID SOLVATION ENERGY RELATIONSHIPS; WATER PARTITION-COEFFICIENT; MOLECULAR CONNECTIVITY; SOLUBILITY PROPERTIES; BIOLOGICAL MEDIA; AQUATIC SYSTEMS; ORYZIAS-LATIPES; FISH TOXICITY; SHAPE INDEX; CHEMICALS AB Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25 degrees C) and pH (6,7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log K-ow was able to explain about 40-60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40-70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, (1)chi(v) and (3)kappa were best able to describe the variation in response among all compounds at each pH (70-90%). In the presence of sediment, even molecular connectivity could not describe the variability until the partitioning potential to sediment was accounted for by assuming equilibrium partitioning. After correcting for partitioning, the same molecular connectivity terms as in the aqueous exposures described most of the variability, 61-87%, except for the 11 degrees C data where correlations were not significant. Molecular connectivity was a better tool than LSER or the unidimensional variables to explain the steric fitness of OP insecticides which was crucial to the toxicity. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Ohio State Univ, Dept Entomol, Columbus, OH 43210 USA. US Geol Survey, Biol Resources Div, Great Lakes Sci Ctr, Ann Arbor, MI 48105 USA. RP Landrum, PF (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 51 TC 9 Z9 10 U1 3 U2 10 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1062-936X J9 SAR QSAR ENVIRON RES JI SAR QSAR Environ. Res. PY 1999 VL 10 IS 5 BP 423 EP 450 DI 10.1080/10629369908039110 PG 28 WC Chemistry, Multidisciplinary; Computer Science, Interdisciplinary Applications; Environmental Sciences; Mathematical & Computational Biology; Toxicology SC Chemistry; Computer Science; Environmental Sciences & Ecology; Mathematical & Computational Biology; Toxicology GA 269HG UT WOS:000084470200002 ER PT S AU Gage, KS Williams, CR Ecklund, WL Johnston, PE AF Gage, KS Williams, CR Ecklund, WL Johnston, PE BE Stuhlmann, R TI Development and application of Doppler radar profilers to ground validation of satellite precipitation measurements SO SATELLITE APPLICATIONS FOR ENERGY BUDGETS AND THE HYDROLOGICAL CYCLE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A1 1 Symposium of COSPAR Scientific Commission A Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP NASA, NOAA, European Space Agcy, European Org Exploitat Meteorol Sarellite, Natl Space Dev Agcy Japan, Comm Space Res ID WIND AB In this paper we review the development and application of Doppler radar profilers to precipitation measurement with emphasis on ground validation of satellite precipitation measurements such as are obtained with the TRMM satellite. The principal objective of this research is to develop the capability to obtain height-resolved drop-size spectra from the profiler-observed Doppler velocity and equivalent reflectivity measurements. Profiler measurements can also be used in conjunction with disdrometers to calibrate ground-based measurements of equivalent reflectivity. Two profilers operating near 1 GHz and 3 GHz respectively, were used in conjunction with scanning radars and disdrometers during 1998 in Texas and Florida. In this paper we present preliminary comparisons of profiler, scanning radar and disdrometer observations obtained in Houston, Texas in April 1998. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Gage, KS (reprint author), NOAA, Aeron Lab, 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 9 TC 5 Z9 5 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 PY 1999 VL 24 IS 7 BP 931 EP 934 DI 10.1016/S0273-1177(99)00366-X PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP17U UT WOS:000084336800007 ER PT S AU Jacobowitz, H Stowe, L Crandall, C AF Jacobowitz, H Stowe, L Crandall, C BE Stuhlmann, R TI Analysis of cloud-radiative forcing derived from the AVHRR pathfinder atmosphere (PATMOS) 16-year data set SO SATELLITE APPLICATIONS FOR ENERGY BUDGETS AND THE HYDROLOGICAL CYCLE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A1 1 Symposium of COSPAR Scientific Commission A Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP NASA, NOAA, European Space Agcy, European Org Exploitat Meteorol Sarellite, Natl Space Dev Agcy Japan, Comm Space Res AB The influence of clouds on the Earth's radiation budget is analyzed using the PATMOS data set, which spans the period from July 1981 to the present. This data set resulted from reprocessing the Advanced Very High Resolution Radiometer (AVHRR) on-board NOAA sunsynchronous polar-orbiting satellites beginning with NOAA-7. Only satellites having an afternoon equator-crossing time were utilized. The PATMOS dataset, produced as part of the NOAA/NASA Pathfinder Program, provides atmospheric products, which include top of the atmosphere broadband estimates of outgoing longwave and absorbed solar radiation (cloudy and clear-sky). Computation of the differences between the cloudy and clear-sky radiation components (cloud-radiative forcing) yield estimates of the effects of clouds on the radiation. Variations in the cloud-radiative forcing are examined to detect seasonal to interannual climate anomalies, such as caused by the recent El Nine. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. Sci & Technol Corp, Hampton, VA 23666 USA. RP Jacobowitz, H (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, 4700 Silver Hill Rd, Washington, DC 20233 USA. NR 3 TC 1 Z9 1 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 PY 1999 VL 24 IS 7 BP 941 EP 944 DI 10.1016/S0273-1177(99)00360-9 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP17U UT WOS:000084336800009 ER PT S AU Clemente-Colon, P Manousos, PC Pichel, WG Friedman, K AF Clemente-Colon, P Manousos, PC Pichel, WG Friedman, K BE Russell, JE TI Observations of Hurricane Bonnie in spaceborne synthetic aperture radar (SAR) and next generation Doppler weather radar (NEXRAD) SO SATELLITE REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Satellite Remote Sensing of Clouds and the Atmosphere IV CY SEP 20-22, 1999 CL FLORENCE, ITALY SP Univ Florence, Dept Earth Sci, European Opt Soc, SPIE, CNR, NASA, Italian Soc Opt & Photon, Italian Space Agcy DE rain; convective cell; hurricane; synthetic aperture radar; Doppler weather radar ID FOOTPRINTS; STORMS; SEA AB Atmospheric circulation systems have being shown to produce observable signatures on spaceborne synthetic aperture radar (SAR) imagery of the ocean surface. Capillary and small gravity ocean waves of roughly the scale of the SAR electromagnetic wavelength, the so-called Bragg waves, provide the surface roughness that allows for SAR mapping of both ocean and atmospheric mesoscale features. Two RADARSAT SAR images were acquired over Hurricane Bonnie on 25 and 27 August 1998. Simultaneous Doppler weather radar observations were also acquired at next generation radar (NEXRAD) stations on the U.S. East coast. These coincident datasets were coregistered and analyzed The observed ocean patterns in the C-band HH SAR images correlate well with the cyclonic circulation pattern of the hurricane winds and the presence of convective cells within the system. Significant signal attenuation in regions of heavier rainfall is observed in the SAR images. Understanding rain effects in SAR imagery is of increasing importance as we develop new scatterometer-like algorithms to produce high-resolution winds from spaceborne SAR imagery. Increased knowledge of hurricane SAR signatures will also help us derive reliable information on offshore storms that cannot be easily obtained from other sources. C1 NOAA, NESDIS Off Res & Applicat, Camp Springs, MD 20746 USA. RP Clemente-Colon, P (reprint author), NOAA, NESDIS Off Res & Applicat, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 16 TC 3 Z9 3 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 0-8194-3462-0 J9 P SOC PHOTO-OPT INS PY 1999 VL 3867 BP 63 EP 70 DI 10.1117/12.373044 PG 8 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BP46E UT WOS:000085206300008 ER PT S AU Lawn, BR Lee, SK Lee, KS AF Lawn, BR Lee, SK Lee, KS BE Niihara, K Sekino, T Yasuda, E Sasa, T TI Fracture and deformation damage accumulation in tough ceramics SO SCIENCE OF ENGINEERING CERAMICS II SE Key Engineering Materials LA English DT Article; Proceedings Paper CT 2nd International Symposium on Science of Engineering Ceramics (EnCera 98) CY SEP 06-09, 1998 CL OSAKA, JAPAN SP Ceram Soc Japan, Amer Ceram Soc, European Ceram Soc, Fine Ceram Res Assoc DE ceramics; cone cracks; contact damage; quasi-plasticity; silicon nitride; strength ID HETEROGENEOUS GRAIN-STRUCTURE; HERTZIAN CONTACT DAMAGE; SILICON-CARBIDE; CYCLIC FATIGUE; POLYCRYSTALLINE CERAMICS; 2-PHASE CERAMICS; ALUMINA; STRENGTH; CURVES; MODEL AB A study on the role of microstructure in the contact damage and fatigue of tough ceramics, using in-situ-toughened silicon nitride as a case study, is described. The thrust of the study is on fundamental mechanics of damage accumulation in relation to microstructural design. A focal point is the characterization and evaluation of new quasi-plastic modes of damage, in addition to the conventional fracture modes, that can limit the long-term performance of tougher ceramics under concentrated loading conditions. Ultimate goals are as follows: (i) to investigate the interrelations between these damage modes and associated mechanical properties, notably strength properties and fatigue resistance; (ii) to develop new silicon nitrides with controlled microstructures for high resistance to damage accumulation; (iii) to fabricate layer structures for maximum toughness and wear resistance. Implications concerning the design of tough materials for bearing applications and coating-substrate technologies will be discussed. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 32 TC 1 Z9 1 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI DURNTEN-ZURICH PA KREUZSTRASSE 10, 8635 DURNTEN-ZURICH, SWITZERLAND SN 1013-9826 BN 0-87849-817-6 J9 KEY ENG MATER PY 1999 VL 2 BP 3 EP 8 PG 6 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BV70B UT WOS:000179851900001 ER PT J AU Baker, DJ AF Baker, DJ TI NOAA: Whole new era of ocean exploration SO SEA TECHNOLOGY LA English DT Article C1 NOAA, US Dept Commerce, Washington, DC 20230 USA. RP Baker, DJ (reprint author), NOAA, US Dept Commerce, Washington, DC 20230 USA. NR 0 TC 1 Z9 1 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 1999 VL 40 IS 1 BP 10 EP 11 PG 2 WC Engineering, Ocean SC Engineering GA 164GT UT WOS:000078455400002 ER PT J AU Baird, RC AF Baird, RC TI Sea grant: Positioning for the next 30 years SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Natl Sea Grant Coll Program, Washington, DC USA. RP Baird, RC (reprint author), NOAA, Natl Sea Grant Coll Program, Washington, DC 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 1999 VL 40 IS 1 BP 24 EP 26 PG 3 WC Engineering, Ocean SC Engineering GA 164GT UT WOS:000078455400007 ER PT J AU Davidson, M Krimm, R Williams, SJ Chesnutt, C Ward, S AF Davidson, M Krimm, R Williams, SJ Chesnutt, C Ward, S TI Managing the impacts of coastal hazards SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Natl Ocean Serv, Rockville, MD 20852 USA. US Geol Survey, Reston, VA 22092 USA. USA, Corps Engineers, Washington, DC 20310 USA. RP Davidson, M (reprint author), NOAA, Natl Ocean Serv, Rockville, MD 20852 USA. NR 10 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 1999 VL 40 IS 1 BP 65 EP 68 PG 4 WC Engineering, Ocean SC Engineering GA 164GT UT WOS:000078455400023 ER PT S AU O'Connor, L Lawrence, RB AF O'Connor, L Lawrence, RB BE Fujisada, H Lurie, JB TI National Polar-orbiting Operational Environmental Satellite System (NPOESS) Interface Data Processing Segment (IDPS) SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites III CY SEP 20-23, 1999 CL FLORENCE, ITALY SP Univ Florence, Dept Earth Sci, European Opt Soc, SPIE, CNR, NASA, Italian Soc Opt & Photon, Italian Space Agcy DE NPOESS; DMSP; FOES; DoD; DOG; polar-orbiting; environmental satellites; data processing; IDPS AB On May 5, 1994, President Clinton made the landmark decision to merge the United States' (US') military and civil operational meteorological satellite systems into a single, national system capable of satisfying both civil and national security requirements for space-based remotely sensed environmental data. For the first time, the US government is taking an integrated approach to identifying and meeting the operational satellite needs of both the civil and national security communities. The joint program formed as a result of President Clinton's direction is known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS). Key to the success of the convergence process are continuing efforts to achieve commonality in the ground data processing segment across US government organizations, in particular within the Departments of Defense (DoD) and Commerce (DOC). The current plans are that five environmental data processing centers, as well as numerous globally-deployed remote field terminals will process the huge volume of satellite data expected to flow from the NPOESS converged satellite system. C1 USAF, Natl Polar Orbiting Operat Environm Satellite Sys, Integrated Program Off, Silver Spring, MD 20910 USA. RP Lawrence, RB (reprint author), NOAA, NESDIS, Natl Polar Orbiting Operat Environm Satellite Sys, Integrated Program Off, Silver Spring, MD 20910 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3465-5 J9 P SOC PHOTO-OPT INS PY 1999 VL 3870 BP 562 EP 574 DI 10.1117/12.373164 PG 13 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BP56D UT WOS:000085492800059 ER PT B AU Schmidt, C Harman, D AF Schmidt, C Harman, D BE Hearst, M Gey, F Tong, R TI Information retrieval library (IRLIB) SO SIGIR'99: PROCEEDINGS OF 22ND INTERNATIONAL CONFERENCE ON RESEARCH AND DEVELOPMENT IN INFORMATION RETRIEVAL LA English DT Proceedings Paper CT 22nd International Conference on Research and Development in Information Retrieval CY AUG, 1999 CL UNIV CA, BERKELEY, CA SP British Comp Soc, Info Retriev Special Grp, Gesell Info Germany, Microsoft, West Grp, AT&T Labs, Sun Microsyst, Verity, Xerox Parc, IBM, Lexis-Nexis HO UNIV CA DE digital library; archival documents AB The IRLIB is a full-text web searchable digital library, whose contents are publications and documents relative to the field of information retrieval. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Schmidt, C (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8940, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036-9998 USA BN 1-58113-096-1 PY 1999 BP 331 EP 331 PG 1 WC Computer Science, Information Systems SC Computer Science GA BN86U UT WOS:000083284000073 ER PT B AU Vogel, EM Wortman, JJ AF Vogel, EM Wortman, JJ BE Sundaram, KB Deen, MJ Brown, WD Sah, RE Poindexter, E Misra, D TI Properties of n- and p-channel mosfets with ultrathin RTCVD oxynitride gate dielectrics SO SILICON NITRIDE AND SILICON DIOXIDE THIN INSULATING FILMS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 5th International Symposium on Silicon Nitride and Silicon Dioxide Thin Insulating Films CY MAY 02-07, 1999 CL SEATTLE, WA SP Electrochem Soc, Dielect Sci & Technol Div, Electrochem Soc, Electr & High Temp Mat Div ID CHEMICAL-VAPOR-DEPOSITION; OXIDE BREAKDOWN; SILICON DIOXIDE; GENERATION; FILMS AB A detailed study of the electrical properties of n-channel and p-channel MOSFETs with ultra-thin (2.0 nm to 3.0 nm) N2O annealed Rapid Thermal Chemical Vapor Deposited (RTCVD) oxynitrides and Rapid Thermal Oxides (RTO) is presented. The characterization methodologies for capacitance-voltage, effective mobility, tunneling and reliability were critically analyzed to provide meaningful comparisons of the dielectrics. The results of the characterization indicate that an ultra-thin RTCVD oxynitride with N2O anneal stops boron penetration, has comparable channel mobility and reliability, and has lower tunnel current as compared to RTO. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Vogel, EM (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 26 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-228-1 J9 ELEC SOC S PY 1999 VL 99 IS 6 BP 90 EP 105 PG 16 WC Computer Science, Hardware & Architecture; Electrochemistry; Engineering, Electrical & Electronic; Materials Science, Coatings & Films SC Computer Science; Electrochemistry; Engineering; Materials Science GA BN99X UT WOS:000083811800009 ER PT S AU Smith, Z Zwickl, R AF Smith, Z Zwickl, R BE Habbal, SR Esser, R Hollweg, JV Isenberg, PA TI Forecasting geomagnetic storms using energetic particle enhancements SO SOLAR WIND NINE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Solar Wind Conference CY OCT 05-09, 1998 CL NANTUCKET, MA SP Amer Inst Phys ID SHOCKS AB It is well established that energetic particle enhancements are due, in part, to acceleration by interplanetary shocks as they propagate towards Earth. Thus the observation of these enhancements at satellites located at L1 can be considered a potential tool for forecasting the arrival of interplanetary shocks and the start of geomagnetic storms in Earth's magnetosphere. The signatures of energetic particle enhancements observed by the WIND spacecraft during the time-period 1996 - 1998 are studied. together with the accompanying interplanetary shocks; their interplanetary drivers; their probable solar sources, and the ensuing geomagnetic storms. The results, based on 115-400 keV ion data, show that enhancements in ion intensity can be seen up to several days in advance of the arrival of the shock. Therefore monitoring the energetic particles will allow predictions/warnings of up to 3 days in advance. C1 NOAA, SEC, Boulder, CO 80303 USA. RP Smith, Z (reprint author), NOAA, SEC, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 6 Z9 6 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 1-56396-865-7 J9 AIP CONF PROC PY 1999 VL 471 BP 577 EP 580 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA BN29A UT WOS:000081435700125 ER PT S AU Odstrcil, D Pizzo, VJ AF Odstrcil, D Pizzo, VJ BE Habbal, SR Esser, R Hollweg, JV Isenberg, PA TI 3-D propagation of CMEs near the heliospheric sheet SO SOLAR WIND NINE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Solar Wind Conference CY OCT 05-09, 1998 CL NANTUCKET, MA SP Amer Inst Phys ID MAGNETIC STORMS; SOLAR-WIND AB A 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 how 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 with a monopolar interplanetary magnetic field (IMF). 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. C1 Univ Colorado, NOAA, CIRES, Boulder, CO 80303 USA. RP Odstrcil, D (reprint author), Univ Colorado, NOAA, CIRES, 325 Broadway, Boulder, CO 80303 USA. NR 6 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 1-56396-865-7 J9 AIP CONF PROC PY 1999 VL 471 BP 661 EP 664 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA BN29A UT WOS:000081435700146 ER PT S AU Pizzo, VJ Odstrcil, D AF Pizzo, VJ Odstrcil, D BE Habbal, SR Esser, R Hollweg, JV Isenberg, PA TI Three-dimensional propagation of CMEs in the heliosphere SO SOLAR WIND NINE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Solar Wind Conference CY OCT 05-09, 1998 CL NANTUCKET, MA SP Amer Inst Phys ID ULYSSES AB A 3-D hydrodynamic numerical model is used to investigate the essential physics of the large-scale interaction between CMEs and the structured background solar wind. A tilted-dipole steady outflow configuration is established by numerical relaxation between 0.14 and 5.04 AU. Time-dependent velocity and pressure pulses are introduced at the inner boundary at differing locations with respect to the corotating streamer belt flaw. Results show that CMEs may be significantly distorted due mainly to local variations in the background flow speed geometry. Thus an individual CME can present radically different appearances at various locations in the heliosphere. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Pizzo, VJ (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 5 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 1-56396-865-7 J9 AIP CONF PROC PY 1999 VL 471 BP 665 EP 668 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA BN29A UT WOS:000081435700147 ER PT S AU Detman, T Joselyn, J AF Detman, T Joselyn, J BE Habbal, SR Esser, R Hollweg, JV Isenberg, PA TI Real-time Kp predictions from ACE real time solar wind SO SOLAR WIND NINE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Solar Wind Conference CY OCT 05-09, 1998 CL NANTUCKET, MA SP Amer Inst Phys AB The Advanced Composition Explorer (ACE) spacecraft provides nearly continuous monitoring of solar wind plasma, magnetic fields, and energetic particles from the Sun-Earth L1 Lagrange point upstream of Earth in the salar wind. The Space Environment Center (SEC) in Boulder receives ACE telemetry from a group of international network of tracking stations. One-minute, and I-hour averages of solar wind speed, density, temperature, and magnetic field components are posted on SEC's World Wide Web page within 3 to 5 minutes after they are measured. The ACE Real Time Solar Wind (RTSW) can be used to provide real-time warnings and short term forecasts of geomagnetic storms based on the (traditional) Kp index. Here, we use historical data to evaluate the performance of the first real-time Kp prediction algorithm to become operational. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Detman, T (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 7 TC 8 Z9 9 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 1-56396-865-7 J9 AIP CONF PROC PY 1999 VL 471 BP 729 EP 732 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA BN29A UT WOS:000081435700163 ER PT J AU Benedict, LX Wethkamp, T Wilmers, K Cobet, C Esser, N Shirley, EL Richter, W Cardona, M AF Benedict, LX Wethkamp, T Wilmers, K Cobet, C Esser, N Shirley, EL Richter, W Cardona, M TI Dielectric function of wurtizite GaN and AlN thin films SO SOLID STATE COMMUNICATIONS LA English DT Article DE semiconductors; electronic band structure; optical properties; synchrotron radiation ID AB-INITIO CALCULATION; SPECTROSCOPIC ELLIPSOMETRY; TEMPERATURE-DEPENDENCE; OPTICAL-ABSORPTION; CRITICAL-POINTS; SI; GE; SEMICONDUCTORS; TRANSITIONS; INSULATORS AB Measurements and calculations of the dielectric function of wurtzite GaN and AIN are presented. Spectroscopic ellipsometry was used to determine epsilon(omega) Of thin film samples in the energy range from 3 to 9.8 eV. Calculations of epsilon(omega) for the bulk materials were performed within a first-principles electronic structure scheme that includes the electron-hole interaction. The agreement between experiment and theory is dramatically improved over the previous work, a result of improvements in both experimental technique and theoretical description. The predicted polarization dependence of the dielectric function of these materials exhibits features similar to that in other wurtzite structure materials. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, H Div, Phys Directorate, Livermore, CA 94550 USA. Tech Univ Berlin, Inst Festkorperphys, D-10623 Berlin, Germany. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. NIST, Opt Technol Div, Phys Lab, Gaithersburg, MD 20899 USA. RP Lawrence Livermore Natl Lab, H Div, Phys Directorate, Livermore, CA 94550 USA. EM benedict@fruitloops.llnl.gov NR 30 TC 61 Z9 63 U1 5 U2 31 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 EI 1879-2766 J9 SOLID STATE COMMUN JI Solid State Commun. PY 1999 VL 112 IS 3 BP 129 EP 133 DI 10.1016/S0038-1098(99)00323-3 PG 5 WC Physics, Condensed Matter SC Physics GA 234EZ UT WOS:000082472700002 ER PT S AU Udovic, TJ Yildirim, T Karmonik, C Huang, Q AF Udovic, TJ Yildirim, T Karmonik, C Huang, Q BE Nazri, GA Julien, C Rougier, A TI The applications of neutron scattering methods to the study of high-temperature protonic conductors SO SOLID STATE IONICS V SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Solid State Ionics at the 1998 MRS Fall Meeting CY NOV 28-DEC 04, 1999 CL BOSTON, MA SP Mat Res Soc, US DOE, Lawrence Berkeley Natl Lab ID SPECTROSCOPY; DIFFUSION AB Perovskite-based high-temperature protonic conductors have generated increased interest because of their potential use in such areas as solid-oxide fuel-cell technology. In this paper, we outline the utility of neutron scattering methods in conjunction with first-principles total-energy calculations for characterizing the proton dynamics in these materials. C1 Natl Inst Stand & Technol, NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Udovic, TJ (reprint author), Natl Inst Stand & Technol, NIST, Ctr Neutron Res, 100 Bureau Dr,Stop 8562, Gaithersburg, MD 20899 USA. RI yildirim, taner/A-1290-2009 NR 12 TC 2 Z9 2 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-454-8 J9 MATER RES SOC SYMP P PY 1999 VL 548 BP 593 EP 598 PG 6 WC Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Electrochemistry; Energy & Fuels; Materials Science GA BP16R UT WOS:000084260800076 ER PT J AU Diebold, AC Wollman, DA Hilton, GC Irwin, KD Martinis, JM Liu, BYH AF Diebold, AC Wollman, DA Hilton, GC Irwin, KD Martinis, JM Liu, BYH TI Application of microcalorimeter EDS x-ray detectors to particle analysis SO SOLID STATE PHENOMENA LA English DT Article ID HIGH-RESOLUTION AB New microcalorimeter x-ray detector technology will revolutionize materials characterization. It is expected that the microcalorimeter EDS (energy dispersive spectrometer) will replace traditional lithium-drifted silicon semiconductor EDS due to its superior energy resolution (< 4 eV FWHM) and greatly enhanced capability for characterizing low energy x-rays. In this paper, we describe the transition-edge sensor microcalorimeter developed at NIST and demonstrate its superior capability using x-ray spectra of sized, sub-micrometer-diameter particles on silicon surfaces. C1 SEMATECH, Austin, TX 78741 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Minnesota, Minneapolis, MN 55455 USA. RP Diebold, AC (reprint author), SEMATECH, 2706 Montopolis Dr, Austin, TX 78741 USA. NR 10 TC 3 Z9 3 U1 1 U2 2 PU TRANS TECH-SCITEC PUBLICATIONS LTD PI UETIKON A.S. PA BRANDRAIN 6, CH-8707 UETIKON A.S., SWITZERLAND SN 1012-0394 J9 SOLID STATE PHENOM JI Solid State Phenom. PY 1999 VL 65-6 BP 199 EP 202 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 160LU UT WOS:000078232800049 ER PT J AU Shaffner, TJ AF Shaffner, TJ TI Keeping analytical tools in line with NTRS goals: An industry challenge SO SOLID STATE TECHNOLOGY LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Shaffner, TJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM thomas.shaffner@nist.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO PI NORTHBROOK PA P O BOX 3284, NORTHBROOK, IL 60065-3284 USA SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD JAN PY 1999 VL 42 IS 1 BP 36 EP + PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 158WQ UT WOS:000078140800018 ER PT J AU Gosling, JT Pizzo, VJ AF Gosling, JT Pizzo, VJ TI Formation and evolution of corotating interaction regions and their three dimensional structure SO SPACE SCIENCE REVIEWS LA English DT Review ID SOLAR-WIND STREAM; LARGE HELIOCENTRIC DISTANCES; HELIOSPHERIC CURRENT SHEET; HIGH HELIOGRAPHIC LATITUDES; QUASI-STEADY DYNAMICS; OUTER HELIOSPHERE; 3-DIMENSIONAL MODEL; CORONAL STREAMERS; HYDRODYNAMIC STREAMS; ULYSSES OBSERVATIONS AB Corotating interaction regions are a consequence of spatial variability in the coronal expansion and solar rotation, which cause solar wind flows of different speeds to become radially aligned. Compressive interaction regions are produced where high-speed wind runs into slower plasma ahead. When the flow pattern emanating from the Sun is roughly time-stationary these compression regions form spirals in the solar equatorial plane that corotate with the Sun, hence the name corotating interaction regions, or CIRs. The leading edge of a CIR is a forward pressure wave that propagates into the slower plasma ahead, while the trailing edge is a reverse pressure wave that propagates back into the trailing high-speed flow. At large heliocentric distances the pressure waves bounding a CIR commonly steepen into forward and reverse shocks. Spatial variation in the solar wind outflow from the Sun is a consequence of the solar magnetic field, which modulates the coronal expansion. Because the magnetic equator of the Sun is commonly both warped and tilted with respect to the heliographic equator, CIRs commonly have substantial north-south tilts that are opposed in the northern and southern hemispheres. Thus, with increasing heliocentric distance the forward waves in both hemispheres propagate toward and eventually across the solar equatorial plane, while the reverse shocks propagate poleward to higher latitudes. This paper provides an overview of observations and numerical models that describe the physical origin and radial evolution of these complex three-dimensional (3-D) heliospheric structures. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NOAA, Space Environm Ctr, Boulder, CO USA. RP Gosling, JT (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM jgosling@lan1.gov; vpizzo@sel.noaa.gov NR 65 TC 179 Z9 180 U1 2 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 1999 VL 89 IS 1-2 BP 21 EP 52 DI 10.1023/A:1005291711900 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 286AV UT WOS:000085422200003 ER PT J AU Gazis, PR McDonald, FB Burger, RA Chalov, S Decker, RB Dwyer, J Intriligator, DS Jokipii, JR Lazarus, AJ Mason, GM Pizzo, VJ Potgieter, MS Richardson, IG Lanzerotti, LJ AF Gazis, PR McDonald, FB Burger, RA Chalov, S Decker, RB Dwyer, J Intriligator, DS Jokipii, JR Lazarus, AJ Mason, GM Pizzo, VJ Potgieter, MS Richardson, IG Lanzerotti, LJ CA Working Grp 4 TI Corotating interaction regions in the outer heliosphere - Report of Working Group 4 SO SPACE SCIENCE REVIEWS LA English DT Review ID GALACTIC COSMIC-RAYS; MERGED INTERACTION REGIONS; DEPENDENT DRIFT MODEL; LONG-TERM MODULATION; LARGE HELIOCENTRIC DISTANCES; QUASI-STEADY DYNAMICS; SOLAR-WIND; VOYAGER-2 OBSERVATIONS; SIMULATED FEATURES; PIONEER OBSERVATIONS AB We discuss the structure and evolution of CIRs and their successors in the outer heliosphere. These structures undergo significant evolution as they are convected to greater heliocentric distances. A progression of different types of structure are observed at increasing distance from the Sun. Similar structures are observed at similar heliocentric distance at different portions of the solar cycle. CIRs and their successors are associated with many important physical processes in the outer heliosphere. We discuss the relationship between these structures and recurrent phenomena such as cosmic ray variations, and review some of the associated theoretical models on the role of corotating structures and global merged interaction regions (GMIRs) in global cosmic ray modulation. We also discuss some outstanding questions related to the origin of non-dispersive quasi-periodic particle enhancements associated with CIRs and their successors in the outer heliosphere. C1 NASA, SJSU Fdn, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Potchefstroom Univ Christian Higher Educ, ZA-2520 Potchefstroom, South Africa. Russian Acad Sci, Inst Problems Mech, Moscow 117526, Russia. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Carmel Res Ctr, Santa Monica, CA USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Arizona, Dept Astron, Tucson, AZ USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NOAA, SEC, Boulder, CO USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. AT&T Bell Labs, Murray Hill, NJ USA. RP Gazis, PR (reprint author), NASA, SJSU Fdn, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. OI Richardson, Ian/0000-0002-3855-3634 NR 77 TC 10 Z9 10 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 1999 VL 89 IS 1-2 BP 269 EP 305 DI 10.1023/A:1005270027347 PG 37 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 286AV UT WOS:000085422200014 ER PT S AU Looney, JP van Zee, RD Hodges, JT AF Looney, JP van Zee, RD Hodges, JT BE Herman, RM TI Single-mode cavity ring-down spectroscopy for line shape measurements SO SPECTRAL LINE SHAPES, VOL 10: 14TH ICSLS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 14th International Conference on Spectral Line Shapes CY JUN 22-26, 1998 CL STATE COLL, PA SP Penn State Univ, Corning Inc, Lambda Phys Inc, Thorlabs Inc, Int Union Pure & Appl Phys ID ABSORPTION-MEASUREMENTS AB The precise measurement of absorption line shapes and line strengths is demonstrated using single-mode cavity ring-down spectroscopy. This technique utilizes a pulsed laser to excite a single transverse electromagnetic mode of a high-finesse, stable resonator. From the measurement of the decay time constant of this mode, the optical losses can be determined. As the cavity mode is tuned through an absorption resonance, the variation of the decay rime constant yields a measure of the absorptive losses in the cavity. Spectra of the weak transitions of the molecular oxygen A-band are used to demonstrate the capability of this technique to measure absorption profiles and absolute line strengths. Repeated measurements of the line strength have a standard deviation <0.3 %. C1 NIST, Chem Sci & Technol Lab, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Looney, JP (reprint author), NIST, Chem Sci & Technol Lab, Proc Measurements Div, Gaithersburg, MD 20899 USA. RI Hodges, Joseph/B-4578-2009 NR 12 TC 2 Z9 2 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-754-5 J9 AIP CONF PROC PY 1999 VL 467 BP 275 EP 285 PG 11 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical SC Astronomy & Astrophysics; Physics GA BM95D UT WOS:000080238100048 ER PT J AU Galt, JA Payton, DL AF Galt, JA Payton, DL TI Development of quantitative methods for spill response planning: A trajectory analysis planner SO SPILL SCIENCE & TECHNOLOGY BULLETIN LA English DT Article AB In planning for response to oil spills, a great deal of information must be assimilated. Typically, geophysical flow patterns, ocean turbulence, complex chemical processes, ecological setting, fisheries activities, economics of land use, and engineering constraints on response equipment all need to be considered, This presents a formidable analysis problem. It can be shown, however, that if an appropriate set of evaluation data is available, an objective function and appropriate constraints can be formulated. From these equations, the response problem can be cast in terms of game theory or decision analysis and an optimal solution can be obtained using common scarce-resource allocation methods. The optimal solution obtained by this procedure maximizes the expected return over all possible implementations of a given set of response options. While considering the development of an optimal spill response, it is useful to consider whether (in the absence of complete data) implementing some subset of these methods is possible to pro,ide relevant and useful information for the spill planning process, even though it may fall short of a statistically optimal solution. In this work we introduce a trajectory analysis planning (TAP) methodology that can provide a cohesive framework for integrating physical transport processes, environmental sensitivity of regional sites, and potential response options, This trajectory analysis planning methodology can be shown to implement a significant part of the game theory analysis and provide 'minimum regret' strategy advice, without actually carrying out the optimization procedures. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 NOAA, HAZMAT, Seattle, WA 98115 USA. RP Galt, JA (reprint author), NOAA, HAZMAT, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 15 TC 8 Z9 9 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 1999 VL 5 IS 1 BP 17 EP 28 PG 12 WC Engineering, Environmental; Engineering, Petroleum SC Engineering GA 188KZ UT WOS:000079847100003 ER PT B AU Bruce, S AF Bruce, S BE Buckley, DN Chu, SNG Ren, F TI Measurement services for optoelectronics at NIST SO STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS (SOTAPOCS XXXI) SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 31st State-of-the-Art Program on Compound Semiconductors, at the Joint International Meeting of the Electrochemical-Society/Electrochemical-Society-of-Japan CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc Inc, Electrochem Soc Japan, Japan Soc Appl Phys, Electrochem Soc, Electr Div AB As part of its core mission, the National Institute of Standards and Technology (NIST) offers a variety of hundreds of measurement services to its customers. These services include reference data, reference materials, and physical measurements and calibrations. NIST's work includes: maintaining primary standards; developing new and improved measurement methods; assisting industry, as a neutral party, to standardize on appropriate measurement methods; calibrating measurement devices and instruments; and providing reference materials, artifact standards, so that others may calibrate their own instruments. In the United States, the production of optoelectronics components and equipment comprise an estimated $20B industry. Measurement science plays an important role in characterizing and verifying the performance of currently available optoelectronics; it advances the performance of future optoelectronics; and enables the commerce of optoelectronic products. In the area of optoelectronic metrology, NIST has been developing measurement technology for lasers for nearly 40 years. Since the 1970s, NIST has been developing measurement technology for optical fiber communications and assisting with the development of measurement standards. NIST has Standard Reference Materials for integrated optic components, optical data storage, and semiconductor lasers and LEDs under development. Researchers at NIST have also been studying and modeling color and other electroluminescent properties of LEDs. Historically, NIST has provided radiometric calibrations. The broad suite of radiometric measurements offered by NIST includes: photometric and detector responsivity both of which support the optoelectronics industry. This paper presents an overview of the suite of measurement services that NIST currently offers to support the optoelectronics community. C1 Natl Inst Stand & Technol, Technol Serv, Off Measurement Serv, Calibrat Program, Gaithersburg, MD 20899 USA. RP Bruce, S (reprint author), Natl Inst Stand & Technol, Technol Serv, Off Measurement Serv, Calibrat Program, 100 Bur Dr,Stop 2330, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-240-0 J9 ELEC SOC S PY 1999 VL 99 IS 17 BP 57 EP 63 PG 7 WC Electrochemistry; Physics, Condensed Matter SC Electrochemistry; Physics GA BN80W UT WOS:000082998800008 ER PT B AU McCrary, V Roberts, J AF McCrary, V Roberts, J BE Buckley, DN Chu, SNG Ren, F TI Electronic books: Requirements for displays and storage SO STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS (SOTAPOCS XXXI) SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 31st State-of-the-Art Program on Compound Semiconductors, at the Joint International Meeting of the Electrochemical-Society/Electrochemical-Society-of-Japan CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc Inc, Electrochem Soc Japan, Japan Soc Appl Phys, Electrochem Soc, Electr Div AB Electronic books (e-books) are portable reading appliances that display and store text electronically in contrast to paper-based books. Text is rendered on a flat-panel LCD screen and the content is down-loaded and stored in semiconductor memory. Next generation electronic books will require color displays with low power dissipation, and the ability to store large amounts of data, necessitating the need for optical disc storage. For example, display requirements will have to exceed 177 dpi to fuller render images observed in conventional paper-based format. This paper examines the current trends in displays for small electronic books and personal digital assistants. The trends for writable optical media will also be discussed; in particular, we will examine physical defects observed on DVD and DVD-RAM media, and their impact for high, areal density storage. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McCrary, V (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-240-0 J9 ELEC SOC S PY 1999 VL 99 IS 17 BP 128 EP 139 PG 12 WC Electrochemistry; Physics, Condensed Matter SC Electrochemistry; Physics GA BN80W UT WOS:000082998800016 ER PT J AU Bryant, GW Liu, AS AF Bryant, GW Liu, AS TI Second-harmonic generation of semiconductor quantum dots studied by near-field optical microscopy SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article; Proceedings Paper CT 11th International Conference on Superlattices, Microstructures and Microdevices (ICSMM-11) CY JUL 27-31, 1998 CL HURGADA, EGYPT DE quantum dot; near-field optics; second-harmonic generation ID APPROXIMATION; SPECTROSCOPY; WIRE AB We present a theoretical study of optical second-harmonic generation (SHG) of symmetric semiconductor quantum dots (QDs) excited by the near field of the tip in a near-field scanning optical microscope. We show that the usual optical transition selection rules for the SH nonlinear interaction between the tip field and the QD are broken when the tip is scanned ever the QD, because the tip field varies rapidly over the QD domain. It is also demonstrated that the tip-position dependence of the SH signal essentially maps the spatial distribution of the tip field. (C) 1999 Academic Press. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Bryant, GW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 7 Z9 7 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD JAN-FEB PY 1999 VL 25 IS 1-2 BP 361 EP 365 DI 10.1006/spmi.1998.0659 PG 5 WC Physics, Condensed Matter SC Physics GA 170HA UT WOS:000078799200061 ER PT S AU Sung, LP Mulholland, GW Germer, TA AF Sung, LP Mulholland, GW Germer, TA BE Stover, JC TI Polarization of light scattered by particles on silicon wafers SO SURFACE CHARACTERIZATION FOR COMPUTER DISKS, WAFERS, AND FLAT PANEL DISPLAYS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Surface Characterization for Computer Disks, Wafers, and Flat Panel Displays CY JAN 28, 1999 CL SAN JOSE, CA SP SPIE DE bidirectional ellipsometry; particles; polarimetry; polystyrene latex spheres; scattered light; surfaces ID OUT-OF-PLANE; LOW-PRESSURE IMPACTOR; MUELLER MATRIX; SURFACE; RAYLEIGH; SPHERES; DESIGN AB Bidirectional ellipsometry has been developed as a technique for distinguishing among various scattering features near surfaces. Employing incident light with fixed polarization, the technique measures the principal angle of polarization and the degree of linear polarization of light scattered into directions out of the plane of incidence. This technique has been previously shown to be successful at distinguishing between subsurface defects and microroughness. Theoretical models have predicted that the polarization of light scattered by particles should also be different than that scattered by subsurface defects and microroughness. In this paper, experimental results will be presented which show good agreement with these models for a range of sizes of polystyrene latex spheres on silicon wafers. The results demonstrate that the polarization of light scattered by particles can be used to determine the size of particulate contaminants on silicon wafers and other smooth surfaces. The model calculations, based on different degrees of approximation, demonstrate that the mean distance of a particle from the surface is the primary determinant of the scattered light polarization for small scattering angles. C1 NIST, Gaithersburg, MD 20899 USA. RP Sung, LP (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 24 TC 4 Z9 4 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3089-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3619 BP 80 EP 89 DI 10.1117/12.343715 PG 10 WC Materials Science, Characterization & Testing; Optics SC Materials Science; Optics GA BM84R UT WOS:000079917100009 ER PT J AU Held, IM AF Held, IM TI The macroturbulence of the troposphere SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article; Proceedings Paper CT International Symposium to Commemorate the 100th Anniversary of the Birth of Carl Gustaf Rossby (Rossby-100) CY JUN 08-12, 1998 CL STOCKHOLM, SWEDEN SP Stockholm Univ Dept Meteorol ID HEAT-TRANSPORT; CLIMATE MODEL; EDDY FLUXES; BETA-PLANE; ATMOSPHERE; JETS; CIRCULATIONS; TURBULENCE; REGIONS; WAVES AB Eddy length scales, eddy velocity scales, and the amplitude of eddy fluxes in the mid-latitude troposphere are discussed, primarily from the qualitative perspective provided by studies of quasi-geostrophic turbulence. The utility of a diffusive picture for the near surface poleward flux of heat is emphasized, as is the extent to which a full closure theory for the troposphere, including the interior potential vorticity fluxes, must revolve around this theory for the heat flux. A central problem in general circulation theory is then to determine which factors control the horizontal diffusivity near the surface. The baroclinic eddy production problem has distinctive features that make it stand out from other inhomogeneous turbulence problems such as Benard convection and laboratory shear flows, the crucial point being that there can be scale separation between the eddies and the scale of the mean how inhomogeneity in the direction of the relevant transport. This scale separation makes diffusive closures more compelling. In addition, it allows one to compute diffusivities from models of homogeneous turbulence. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Held, IM (reprint author), NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NR 26 TC 53 Z9 53 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD JAN-FEB PY 1999 VL 51 IS 1 BP 59 EP 70 DI 10.1034/j.1600-0889.1999.00006.x PG 12 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 177QZ UT WOS:000079223700006 ER PT J AU Manabe, S Stouffer, RJ AF Manabe, S Stouffer, RJ TI The role of thermohaline circulation in climate SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article; Proceedings Paper CT International Symposium to Commemorate the 100th Anniversary of the Birth of Carl Gustaf Rossby (Rossby-100) CY JUN 08-12, 1998 CL STOCKHOLM, SWEDEN SP Stockholm Univ Dept Meteorol ID OCEAN-ATMOSPHERE MODEL; NORTH-ATLANTIC OCEAN; YOUNGER DRYAS EVENT; FRESH-WATER INPUT; INTERDECADAL VARIATIONS; SURFACE-TEMPERATURE; CARBON-DIOXIDE; COUPLED MODEL; SEA; CO2 AB This article discusses the role of the THC in climate, based upon the results of several numerical experiments which use a coupled ocean-atmosphere model developed at the Geophysical Fluid Dynamics Laboratory of NOAA, USA. The first part of the article explores the mechanism which is responsible for the abrupt climate change such as the Younger Dryas event using the coupled model. In response to the freshwater discharge into high north Atlantic latitudes over a period of 500 years, the THC in the Atlantic Ocean weakens, reducing surface air temperature over the northern north Atlantic Ocean, the Scandinavian Peninsula, and the circumpolar ocean and Antarctic Continent of the southern hemisphere. Upon the termination of the water discharge at the 500th year, the THC begins to intensify, regaining its original intensity in a few hundred years. In addition, the sudden onset and the termination of the discharge of freshwater induces the multidecadal fluctuation in the intensity of the THC, which generates the almost abrupt change of climate. It is noted that similar but much weaker oscillation of the THC is also evident in the control integration of the coupled model without freshwater forcing. The irregular oscillation of the THC mentioned above appears to be related to the fluctuation of the Subarctic Gyre and associated east Greenland current, yielding the evolution of the surface salinity anomaly which resembles that of "great salinity anomaly". The second part of this article describes the response of a coupled ocean-atmosphere model to the doubling and quadrupling of atmospheric carbon dioxide over centuries time-scale. In one integration, the CO2 concentration increases by 1%/year (compounded) until it reaches 4 x the initial value at the 140th year and remains unchanged thereafter. In another integration, the CO2 concentration also incleases at the rate of 1%/year until it reaches 2x the initial value at the 70th year and remains unchanged thereafter. One of the most notable features of the CO2-quadrupling integration is the gradual disappearance of thermohaline circulation in most of the model oceans during the first 250-year period, leaving behind wind-driven cells. For example, thermohaline circulation nearly vanishes in the north Atlantic by the 250 years of the integration and remains very weak until the 900th year. However, it begins to restore the original intensity by the 1600th year. In the CO2-doubling integration, the thermohaline circulation weakens by a factor of more than 2 in the North Atlantic during the first 150 years, but almost recovers its original intensity by the 500th year. The weakening of the THC moderates temporarily the greenhouse warming over the north Atlantic Ocean and its vicinity. In both numerical experiments described above, the initial weakening of the THC results from the capping of oceanic surface by relatively fresh, low-density water, which surpresses the convective cooling of water in the sinking region of the THC. C1 Frontier Res Syst Global Change, Inst Global Change Res, Minato Ku, Tokyo 1056791, Japan. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Manabe, S (reprint author), Frontier Res Syst Global Change, Inst Global Change Res, Minato Ku, 7F SEAVANS-N Bldg,Shibaura 1-2-1, Tokyo 1056791, Japan. EM sm@frontier.esto.or.jp NR 47 TC 109 Z9 111 U1 3 U2 22 PU CO-ACTION PUBLISHING PI JARFALLA PA RIPVAGEN 7, JARFALLA, SE-175 64, SWEDEN SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD JAN-FEB PY 1999 VL 51 IS 1 BP 91 EP 109 PG 19 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 177QZ UT WOS:000079223700008 ER PT S AU Nolen, S Koch, J Paulter, N Reintsema, CD Grossman, EN AF Nolen, S Koch, J Paulter, N Reintsema, CD Grossman, EN BE Hwu, RJ Wu, K TI Antenna-coupled niobium bolometers for mm-wave imaging arrays SO TERAHERTZ AND GIGAHERTZ PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Terahertz and Gigahertz Photonics CY JUL 19-23, 1999 CL DENVER, CO SP SPIE DE antenna-coupled bolometers; millimeter-wave ID MICROBOLOMETERS AB Antenna-coupled thin-film niobium microbolometers designed for mm-wave imaging arrays have been fabricated and their electrical properties measured. The niobium bolometers are operated at room temperature and are located at the feeds of half-wave dipole antennas on an electrically thick silicon substrate. We independently measured the resistance of the microbolometers as a function of temperature and the dynamic resistance as a function of DC bias current, yielding the electrical responsivity and thermal conductance of the bolometers. The latter is dominated by conduction through a deposited SiO2 isolation layer. We describe electrical measurements of the bolometers' pulse response and noise, performed by illuminating the bolometers with a high power, pulsed mm-wave source. We discuss these measurements in the context of the pulsed detection architecture planned for an active mm-wave imaging system currently under development. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Nolen, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 7 TC 9 Z9 9 U1 0 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 0-8194-3281-4 J9 P SOC PHOTO-OPT INS PY 1999 VL 3795 BP 279 EP 286 DI 10.1117/12.370173 PG 8 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BP33W UT WOS:000084753700029 ER PT S AU Knopp, KJ Christensen, DH Vander Rhodes, G Pomeroy, JM Goldberg, BB Unlu, MS AF Knopp, KJ Christensen, DH Vander Rhodes, G Pomeroy, JM Goldberg, BB Unlu, MS BE Fallahi, M Linden, KJ Wang, SC TI Spectral mapping of multimode vertical-cavity surface-emitting lasers by near-field scanning optical microscopy SO TESTING, PACKAGING, RELIABILITY, AND APPLICATIONS OF SEMICONDUCTOR LASERS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Testing, Packaging, Reliability, and Applications of Semiconductor Lasers IV CY JAN 28, 1999 CL SAN JOSE, CA SP SPIE, Defense Adv Res Projects Agcy DE vertical-cavity surface-emitting laser; microscopy; near-field; transverse modes; spectral-spatial mapping ID VCSELS AB We have studied the spatial and spectral characteristics of vertical-cavity surface-emitting laser (VCSEL) emission using near-field scanning optical microscopy (NSOM). We report the multi-transverse-mode characteristics of 15 mu m diameter proton-implanted 850 nm devices used in 2 Gbit/s multimode fiber-optic links. Spectrally resolved and integrated intensity scans over a 20x20 mu m area were performed. The intensity of each resolvable transverse mode was integrated and its wavelength range false-colored at each scan position. The resulting composite image displays relative intensity and spatial distribution information for each transverse mode. Correlation with the shear force data allows mapping of the optical distributions to topographical features. Lasing filaments were observed at high drive currents. Gain competition among spatially overlapping transverse modes was observed while spatially isolated modes coexisted without competition. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Knopp, KJ (reprint author), Natl Inst Stand & Technol, MS 815-04, Boulder, CO 80303 USA. RI Unlu, Selim/B-4244-2013 NR 16 TC 0 Z9 0 U1 0 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 0-8194-3096-X J9 P SOC PHOTO-OPT INS PY 1999 VL 3626 BP 208 EP 216 DI 10.1117/12.345431 PG 9 WC Optics SC Optics GA BN06D UT WOS:000080521700023 ER PT J AU Wolfelmaier, FA King, CW Mursch-Radlgruber, E Rengarajan, G AF Wolfelmaier, FA King, CW Mursch-Radlgruber, E Rengarajan, G TI Mini-Sodar observations of drainage flows in the Rocky Mountains SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article ID VALLEY; WINDS; METEOROLOGY AB Vertical profiles of drainage winds were monitored continuously by a Doppler-Mini-Sodar during case studies in two valleys, on both sides of the U.S. Continental Divide. A tethered balloon provided additional information on the vertical temperature and wind structure up to the Divide level. Ambient wind data were collected by a radar wind profiler on the west side, and a tower on the crest of the Divide. The onset, evolution and breakup of the drainage flow were studied on two nights, when the ridge-top winds were westerly and skies were clear. To study the influence of the ambient How on drainage winds, changes in drainage wind speed, direction and depth, along with the volume flux were examined. It was found that, on the leeward side, the drainage was strongly influenced by the ambient winds (King, 1995b), which led to interruption and erosion of the locally generated valley flow. The drainage on the wind-ward side of the Divide was almost undisturbed. A comparison of balloon and sodar wind profiles showed very good agreement during steady drainage conditions. C1 Univ Agr Sci, Dept Phys & Meteorol, A-1180 Vienna, Austria. NOAA, ERL, ETL, Boulder, CO 80303 USA. RP Wolfelmaier, FA (reprint author), Univ Agr Sci, Dept Phys & Meteorol, Turkenschanzstr 18, A-1180 Vienna, Austria. NR 16 TC 3 Z9 4 U1 0 U2 2 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 1999 VL 64 IS 1-2 BP 83 EP 91 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 253TG UT WOS:000083571400008 ER PT S AU Lawn, BR Peterson, IM Jung, YG AF Lawn, BR Peterson, IM Jung, YG BE Yasuda, E Wakai, F Manocha, LM Tanabe, Y TI Fatigue and lifetime of biomechanical ceramics SO TIME DEPENDENT MECHANICAL RESPONSE OF ENGINEERING CERAMICS: FROM PICO-SECOND TO MILLION YEARS SE KEY ENGINEERING MATERIALS LA English DT Article; Proceedings Paper CT 2nd Yamazaki International Symposium on Time Dependent Mechanical Response of Engineering Ceramics - From Pico-2nd to Million Years CY SEP 03-04, 1998 CL TOKYO, JAPAN SP TDK, Japan Ceram Soc DE biomechanical ceramics; cone cracks; contact damage; fatigue; strength ID HETEROGENEOUS GRAIN-STRUCTURE; HERTZIAN CONTACTS; DAMAGE ACCUMULATION; SILICON-CARBIDE; CYCLIC FATIGUE; INDENTATION C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lawn, BR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU TRANS TECH PUBLICATIONS PI CLAUSTHAL ZELLERFE PA EINERSBERGER BLICK 28, PO BOX 266, W-3392 CLAUSTHAL ZELLERFE, GERMANY SN 1013-9826 BN 0-87849-832-X J9 KEY ENG MAT PY 1999 VL 4 BP 47 EP 48 PG 2 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN23S UT WOS:000081205100007 ER PT S AU Seidensticker, JR Wiederhorn, SM AF Seidensticker, JR Wiederhorn, SM BE Sakuma, T Aizawa, T Higashi, K TI Investigation of superplasticity in 3Y-TZP by stress relaxation SO TOWARDS INNOVATION IN SUPERPLASTICITY II SE Materials Science Forum LA English DT Article; Proceedings Paper CT 2nd International Conference on Towards Innovation in Superplasticity CY SEP 21-24, 1998 CL KOBE, JAPAN DE superplasticity; stress relaxation; high temperature deformation; 3Y-TZP ID HIGH-TEMPERATURE; ZIRCONIA POLYCRYSTALS; GRAIN-GROWTH; DEFORMATION; CREEP AB Stress relaxation testing was used to study superplasticity in tetragonal zirconia polycrystals stabilized with 3% mol fraction yttria (3Y-TZP). The stress - strain rate behavior measured by this technique compared favorably with data obtained by more traditional techniques, and it is suggested that stress relaxation is an ideal method for studying superplasticity. The range of data obtained provides evidence for three distinct regions of deformation for 3Y-TZP. The action of two deformation mechanisms operating in parallel connected by a threshold stress associated with the high strain rate region can suitably explain the observed behavior of 3Y-TZP. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Seidensticker, JR (reprint author), Natl Inst Stand & Technol, Mat bldg Room B309, Gaithersburg, MD 20899 USA. NR 14 TC 0 Z9 0 U1 1 U2 2 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-828-1 J9 MATER SCI FORUM PY 1999 VL 304-3 BP 403 EP 409 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BN52G UT WOS:000082112300060 ER PT J AU Scott, GI Fulton, MH Moore, DW Wirth, EF Chandler, GT Key, PB Daugomah, JW Strozier, ED Devane, J Clark, JR Lewis, MA Finley, DB Ellenberg, W Karnaky, KJ AF Scott, GI Fulton, MH Moore, DW Wirth, EF Chandler, GT Key, PB Daugomah, JW Strozier, ED Devane, J Clark, JR Lewis, MA Finley, DB Ellenberg, W Karnaky, KJ TI Assessment of risk reduction strategies for the management of agricultural nonpoint source pesticide runoff in estuarine ecosystems SO TOXICOLOGY AND INDUSTRIAL HEALTH LA English DT Article DE azinphosmethyl; best management practices; endosulfan; fenvalerate; grass shrimp; integrated pest management; mummichog; P-glycoprotein; retention ponds ID P-GLYCOPROTEIN; TOXICITY AB Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to toxic levels of pesticides may occur, resulting in significant declines in field populations. Integrated pest management (IPM), best management practices (BMP), and retention ponds (RP) are risk management tools that have been proposed to reduce the contaminant risk from agricultural NPS runoff into estuarine ecosystems. Field studies were conducted at three sites within coastal estuarine ecosystems of South Carolina (SC) from 1985 to 1990 that varied in terms of the amount and degree of risk reduction strategies employed. An intensively managed (IPM, BMP, and RP) agricultural treatment site (TRT) was studied for pesticide runoff impacts. From 1985 to 1987, there were minimal (some IPM and BMP) management activities at TRT, but from 1988 to 1990, TRT was managed using an intensive risk reduction strategy. A second unmanaged agricultural growing area, Kiawah (KWA), was also studied and compared with TRT in terms of pesticide runoff and the resulting impacts on grass shrimp (Palaemonetes pugio) and mummichogs (Fundulus heteroclitus). A third, non-agricultural, reference site (CTL) was used for comparing results from the managed and unmanaged agricultural sites. In situ toxicity tests and field samples of the grass shrimp populations were conducted at each site and compared in terms of survival and the effectiveness of current risk reduction strategies. Significant runoff of insecticides (azinphosmethyl, endosulfan, and fenvalerate) along with several fish kills were observed at TRT prior to the implementation of rigorous risk reduction methods, A significant reduction of in stream pesticide concentrations (up to 90%) was observed at TRT following the implementation of strict NPS runoff controls, which greatly reduced impacts on estuarine fish and shellfish. At the unmanaged KWA, continued impacts due to the runoff of these insecticides were observed, along with several fish kills. Additional monitoring indicated that gravid female grass shrimp populations from KWA had elevated levels of P-glycoprotein (P-gp), a multidrug resistance protein, which may transport various pesticides across cellular membranes. Comparison of field results with laboratory toxicity tests established that pesticide exposure was the primary cause of observed field impacts at each site. These findings clearly indicate the value of an integrated risk reduction strategy (BMP, IPM, and RP) for minimizing impacts from NPS agricultural pesticide runoff. C1 US Natl Ocean & Atmospher Adm, Ctr Coastal Environm Hlth & Biomol Res, Charleston Lab, Charleston, SC 29412 USA. USA, Corps Engineers, Waterways Expt Stn, Vicksburg, MS 39180 USA. Univ S Carolina, Sch Publ Hlth, Columbia, SC 29208 USA. Exxon Biomed, Houston, TX USA. US EPA, Gulf Sci Ecol Div, Gulf Breeze, FL USA. Med Univ S Carolina, Dept Anat & Cell Biol, Marine Biomed & Environm Sci Program, Charleston, SC 29425 USA. Mt Desert Isl Biol Lab, Salsbury Cove, ME 04672 USA. RP Scott, GI (reprint author), US Natl Ocean & Atmospher Adm, Ctr Coastal Environm Hlth & Biomol Res, Charleston Lab, 219 Ft Johnson Rd, Charleston, SC 29412 USA. EM g.scott@noaa.gov FU NIEHS NIH HHS [P30 ES03828] NR 34 TC 64 Z9 66 U1 0 U2 15 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0748-2337 J9 TOXICOL IND HEALTH JI Toxicol. Ind. Health PD JAN-MAR PY 1999 VL 15 IS 1-2 BP 200 EP 213 DI 10.1191/074823399678846673 PG 14 WC Public, Environmental & Occupational Health; Toxicology SC Public, Environmental & Occupational Health; Toxicology GA 295BF UT WOS:000085945500018 PM 10188203 ER PT S AU Jentschura, UD Mohr, PJ Soff, G AF Jentschura, UD Mohr, PJ Soff, G BE Dubin, DHE Schneider, D TI Numerical Lamb shift calculations for low-Z systems SO TRAPPED CHARGED PARTICLES AND FUNDAMENTALS PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Trapped Charged Particles and Fundamental Physics CY AUG 31-SEP 04, 1998 CL PACIFIC GROVE, CA SP Lawrence Livermore Natl Lab ID HYDROGEN AB For bound systems with a small atomic number Z, numerical evaluations of self-energy corrections, which are non-perturbative in the binding field, entail severe numerical cancellations at intermediate stages of the calculation. This paper reports on a result for the non-perturbative self-energy remainder function G(SE) in atomic hydrogen with a relative accuracy of 10(-5). We discuss consistency checks on the results of numerical Lamb shift calculations in systems with a small atomic number. The precise determination of radiative corrections in low-Z bound systems is of crucial importance for the interpretation of precision measurements in atoms, for tests of quantum electrodynamics and for the determination of fundamental constants. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jentschura, UD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 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 1-56396-776-6 J9 AIP CONF PROC PY 1999 VL 457 BP 40 EP 42 PG 3 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields; Spectroscopy SC Physics; Spectroscopy GA BM77Q UT WOS:000079731200005 ER PT S AU Bollinger, JJ Mitchell, TB Huang, XP Itano, WM Tan, JN Jelenkovic, BM Wineland, DJ AF Bollinger, JJ Mitchell, TB Huang, XP Itano, WM Tan, JN Jelenkovic, BM Wineland, DJ BE Dubin, DHE Schneider, D TI Crystalline order in strongly coupled plasmas SO TRAPPED CHARGED PARTICLES AND FUNDAMENTALS PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Trapped Charged Particles and Fundamental Physics CY AUG 31-SEP 04, 1998 CL PACIFIC GROVE, CA SP Lawrence Livermore Natl Lab ID ONE-COMPONENT PLASMA; MONTE-CARLO CALCULATIONS; LASER-COOLED IONS; MELTING TRANSITION; PHASE-TRANSITION; PENNING TRAP; N-DEPENDENCE; STATE; THERMODYNAMICS; DIFFRACTION AB Laser-cooled trapped ions can be strongly coupled and form crystalline states. We describe experimental studies which measure the spatial correlations of Be+ ion crystals formed in Penning traps. Both Bragg scattering of the cooling-laser light and spatial imaging of the laser-induced ion fluorescence are used to measure these correlations. In spherical plasmas with more than 2 x 10(5) ions, body-centered-cubic (bcc) crystals, the predicted bulk structure, are the only type of crystals observed. We are able to phase-lock the orientation of the ion crystals to a rotating electric-field perturbation. With this "rotating wall" technique and stroboscopic detection, images of individual ions in a Penning trap are obtained. The rotating wall technique also provides a precise control of the time-dilation shift due to the plasma rotation, which is important for Penning trap frequency standards. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Bollinger, JJ (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 38 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 1-56396-776-6 J9 AIP CONF PROC PY 1999 VL 457 BP 295 EP 304 PG 10 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields; Spectroscopy SC Physics; Spectroscopy GA BM77Q UT WOS:000079731200041 ER PT S AU Mitchell, TB Bollinger, JJ Huang, XP Itano, WM AF Mitchell, TB Bollinger, JJ Huang, XP Itano, WM BE Dubin, DHE Schneider, D TI Mode and transport studies of laser-cooled ion plasmas in a Penning trap SO TRAPPED CHARGED PARTICLES AND FUNDAMENTALS PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Trapped Charged Particles and Fundamental Physics CY AUG 31-SEP 04, 1998 CL PACIFIC GROVE, CA SP Lawrence Livermore Natl Lab ID PURE ELECTRON-PLASMA; NONNEUTRAL PLASMA; COMPONENT PLASMAS; ORDER; EQUILIBRIA; CRYSTALS; ROTATION; COLUMN; FIELDS AB We describe a technique and present results for imaging the modes of a laser-cooled plasma of Be-9(+) ions in a Penning trap. The modes are excited by sinusoidally time-varying potentials applied to the trap electrodes, or by static field errors. They are imaged by changes in the ion resonance fluorescence produced by Doppler shifts from the coherent ion velocities of the mode. For the geometry and conditions of this experiment, the mode frequencies and eigenfunctions have been calculated analytically. A comparison between theory and experiment for some of the azimuthally symmetric modes shows good agreement. Enhanced radial transport is observed where modes are resonant with static external perturbations, such as those caused by misaligning the trap with respect to the magnetic field. Similarly, the plasma angular momentum can be changed through the deliberate excitation of azimuthally asymmetric modes. The resultant torque can be much greater than that from the "rotating wall" perturbation, which is not mode-resonant. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Mitchell, TB (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 31 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 1-56396-776-6 J9 AIP CONF PROC PY 1999 VL 457 BP 309 EP 318 PG 10 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields; Spectroscopy SC Physics; Spectroscopy GA BM77Q UT WOS:000079731200043 ER PT S AU Young, BC Cruz, FC Berkeland, DJ Rafac, RJ Bergquist, JC Itano, WM Wineland, DJ AF Young, BC Cruz, FC Berkeland, DJ Rafac, RJ Bergquist, JC Itano, WM Wineland, DJ BE Dubin, DHE Schneider, D TI Lasers for an optical frequency standard using trapped Hg(+) ions SO TRAPPED CHARGED PARTICLES AND FUNDAMENTALS PHYSICS SE AIP Conference Proceedings LA English DT Proceedings Paper CT International Conference on Trapped Charged Particles and Fundamental Physics CY AUG 31-SEP 04, 1998 CL PACIFIC GROVE, CA SP Lawrence Livermore Natl Lab ID CONTINUOUS-WAVE LIGHT; QUANTUM JUMPS; YAG LASER; STATE; DIODE; FLUORESCENCE; SPECTROSCOPY; TRANSITION; OSCILLATOR; ATOM AB We are developing an optical frequency standard based on the narrow 281.5 nm transition of trapped (199)Hg(+) ions. A major step toward the completion of this standard is the construction of an isolated high-finesse Fabry-Perot cavity to stabilize the local oscillator. The cavity system that we have assembled has enabled the creation of an optical frequency source with good short-term stability. Eventually, this frequency source will derive long-term stability from a lock to the Hg(+) transition. We have recently demonstrated an improved linewidth of 0.6 Hz (40 s averaging time) for a 563 nm dye laser locked to our stable cavity. Additionally, we are developing solid-state laser replacements for gas and dye lasers presently used for driving 194 nm and 281.5 nm Hg(+) transitions. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Young, BC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Cruz, Flavio/A-6346-2012 OI Cruz, Flavio/0000-0003-3995-7910 NR 35 TC 0 Z9 0 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 1-56396-776-6 J9 AIP CONF PROC PY 1999 VL 457 BP 337 EP 342 PG 6 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields; Spectroscopy SC Physics; Spectroscopy GA BM77Q UT WOS:000079731200047 ER PT S AU Monroe, C Itano, WM Kielpinski, D King, EB Leibfried, D Myatt, CJ Turchette, QA Wineland, DJ Wood, CS AF Monroe, C Itano, WM Kielpinski, D King, EB Leibfried, D Myatt, CJ Turchette, QA Wineland, DJ Wood, CS BE Dubin, DHE Schneider, D TI Quantum logic with a few trapped ions SO TRAPPED CHARGED PARTICLES AND FUNDAMENTALS PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Trapped Charged Particles and Fundamental Physics CY AUG 31-SEP 04, 1998 CL PACIFIC GROVE, CA SP Lawrence Livermore Natl Lab ID COMPUTER; SPECTROSCOPY; COMPUTATION; STATES AB Small laser-cooled crystals of atomic ions have attracted considerable interest in the last several years for their possible application toward quantum computation. This paper considers quantum logic schemes for small numbers of ions in the context of recent experiments at NIST. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Monroe, C (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 30 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-776-6 J9 AIP CONF PROC PY 1999 VL 457 BP 378 EP 387 PG 10 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields; Spectroscopy SC Physics; Spectroscopy GA BM77Q UT WOS:000079731200053 ER PT S AU Richter, CA Nguyen, NV Alers, GB AF Richter, CA Nguyen, NV Alers, GB BE Huff, HR Richter, CA Green, ML Lucovsky, G Hattori, T TI Spectroscopic ellipsometry of Ta2O5 on Si SO ULTRATHIN SIO2 AND HIGH-K MATERIALS FOR ULSI GATE DIELECTRICS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Ultrathin SiO2 and High-K Materials for ULSI Gate Dielectrics, at the 1999 MRS Spring Meeting CY APR 05-08, 1999 CL SAN FRANCISCO, CA SP Mat Res Soc, Hitachi Ltd, Mitsubishi Elect Corp, NEC Corp, Texas Instruments, Tsukuba R&D Ctr, Toshiba Corp, Sony Corp ID THIN-FILMS; SILICON AB In this paper, we present the results of spectroscopic ellipsometry (SE) studies of Ta2O5 films on Si. Based on these results, we have experimentally determined an effective method for analyzing SE measurements of Ta2O5. A set of CVD-grown Ta2O5 films on silicon - with thicknesses ranging from below 10 nm to approximately 60 nm thick - was investigated by SE in an effort to improve optical film thickness metrology for Ta2O5. The samples were measured across the spectral range 1.5 eV to 6.0 eV by using a well-characterized, high-accuracy rotating-analyzer-type ellipsometer. We present an analysis method, based upon a Tauc-Lorentz parameterization of the optical properties of Ta2O5, that properly describes the SE data. We also demonstrate how optical properties are affected by the presence of an interlayer at the Si/Ta2O5 interface. Our results show small, but meaningful variations in optical parameters resulting from variations in deposition processes and annealing conditions. This work demonstrates that SE can be used successfully to characterize this category of alternate gate dielectrics. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Richter, CA (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 12 TC 6 Z9 6 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-474-2 J9 MATER RES SOC SYMP P PY 1999 VL 567 BP 559 EP 566 PG 8 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Computer Science; Engineering; Materials Science GA BN72M UT WOS:000082728600077 ER PT S AU Reader, J Sansonetti, CJ AF Reader, J Sansonetti, CJ BE Carruthers, GR Dymond, KF TI Modern wavelength standards in the ultraviolet and vacuum ultraviolet SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE wavelength standards; ultraviolet; mercury; platinum; hollow cathode ID MERCURY PENCIL LAMPS; SPECTRAL-LINES; CATHODE; VI AB In recent work at the National Institute of Standards and Technology the Atomic Spectroscopy Group has characterized several sources of wavelength standards useful for remote sensing applications. At low resolution, mercury pencil-type lamps are convenient for use either in the laboratory or the field. We recommend wavelengths for this lamp with an uncertainty of +/-0.001 Angstrom in the region 2536 Angstrom to 5790 Angstrom. We also provide relative irradiances for the most prominent Hg lines, data that can be used to determine instrumental response. For high-resolution applications, we have measured wavelengths and relative intensities emitted by a commercial Pt/Ne hollow cathode lamp. Wavelengths for 5600 lines from 1130 Angstrom to 4330 Angstrom, some with uncertainties as small as +/-0.0004 Angstrom, are available in a comprehensive atlas of this lamp. Excellent calibration lines can also be obtained from demountable hollow cathode lamps. We review wavelength standards in Fe I and II, Th I and II, Ar II, and Cu II that can be excited in such lamps. Cu II provides wavelengths with uncertainties of less than +/-0.0004 Angstrom from 670 Angstrom through the entire ultraviolet region. For calibrations at shorter wavelengths, we have developed accurate standards that can be excited in a sliding-spark discharge with yttrium electrodes. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Reader, J (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 23 TC 0 Z9 0 U1 0 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 2 EP 8 DI 10.1117/12.364143 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800001 ER PT S AU Barnes, PY Nadal, ME Early, EA AF Barnes, PY Nadal, ME Early, EA BE Carruthers, GR Dymond, KF TI Reflectance standards at ultraviolet wavelengths SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE bidirectional reflectance distribution function; diffuse reflectance; PTFE; reflectance; ultraviolet AB Polytetrafluoroethylene (PTFE) is widely used in remote sensing applications requiring a diffuse reflectance standard for detector calibration. The bi-directional and directional-hemispherical reflectance properties of both pressed and sintered PTFE were measured at ultraviolet wavelengths to provide information for their use as standards in this spectral range. The reflectance decreases with decreasing wavelength for both geometries, and the ratio between the reflectances for these geometries remains constant for wavelengths from 300 nm to 400 nm. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Barnes, PY (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 8 TC 2 Z9 2 U1 0 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 9 EP 14 DI 10.1117/12.364154 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800002 ER PT S AU Vest, RE Canfield, LR Furst, ML Graves, RM Hamilton, AD Hughey, LR Lucatorto, TB Madden, RP AF Vest, RE Canfield, LR Furst, ML Graves, RM Hamilton, AD Hughey, LR Lucatorto, TB Madden, RP BE Carruthers, GR Dymond, KF TI NIST programs for calibrations in the far ultraviolet spectral region SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE far ultraviolet; extreme ultraviolet; deep ultraviolet; radiometry; calibrations; synchrotron radiation; transfer standard; detector; photodiode ID SILICON PHOTODIODES; FACILITY AB The National Institute of Standards and Technology (MST) serves the growing ultraviolet user community by providing calibration services throughout the spectral range from 2 nm to 400 nm. In this paper we describe the far ultraviolet transfer standard detector program, the NASA-supported Spectrometer Calibration Beamline at the Synchrotron Ultraviolet Radiation Facility, SURF III, and the recent upgrade of the SURF electron storage ring. Several types of transfer standard detectors are issued by NIST in the spectral range from 5 nm to 254 nm: Al2O3 windowless photoemissive devices, CsTe photoemissive devices with integrated MgF2 windows, and radiation-hardened, semiconductive Si photodiodes. The Spectrometer Calibration Beamline makes use of the calculable, undispersed synchrotron radiation from SURF III as a standard of spectral irradiance from 2 nm to 400 nm. The upgrade of SURF has greatly improved the accuracy of calibrations based on SURF, as well as extending the useful spectral range to shorter wavelengths. Taken together, the transfer standard detector program and the calibration beamline at SURF III offer a unique calibration resource for scientists and engineers working in the far ultraviolet spectral region. C1 Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Vest, RE (reprint author), Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. NR 19 TC 14 Z9 14 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 15 EP 26 DI 10.1117/12.364157 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800003 ER PT S AU Gupta, R Lykke, KR Shaw, PS Dehmer, JL AF Gupta, R Lykke, KR Shaw, PS Dehmer, JL BE Carruthers, GR Dymond, KF TI Characterization of UV-induced radiation damage to Si-based photodiodes SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE photodiodes; silicon; ultraviolet; cryogenic radiometer; synchrotron radiation ID QUANTUM EFFICIENCY; ULTRAVIOLET AB We have made direct measurements of the internal quantum efficiency and the reflectivity of W-damaged silicon photodiodes in the spectral range of 125 nm to 320 nm. The above quantities, coupled with absolute spectral responsivities, may yield unique information leading to the identification of the mechanisms responsible for the degradation of performance of the silicon photodiodes in the ultraviolet. The measurements were made using synchrotron radiation from the NIST synchrotron ultraviolet radiation facility (SURF) and an absolute cryogenic radiometer as a primary standard detector. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Gupta, R (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 16 TC 4 Z9 4 U1 0 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 27 EP 33 DI 10.1117/12.364158 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800004 ER PT S AU Thompson, A Early, EA AF Thompson, A Early, EA BE Carruthers, GR Dymond, KF TI Portable high accuracy double spectrometer for ultraviolet spectral irradiance measurements SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE ultraviolet; spectral irradiance; irradiance; spectroradiometer ID MONITORING SPECTRORADIOMETERS; STANDARDS; SURF; NM AB A portable high accuracy double spectrometer for ultraviolet (UV) spectral irradiance measurements has been under development at the National Institute of Standards and Technology (NIST) for several years. It has been used in the comparison of NIST spectral irradiance sources: an electron storage ring, 1000 W quartz-halogen lamps, deuterium are lamps, and a windowless argon miniarc. A. UV spectral irradiance intercomparison with the Physikalische Technische Bundesanstalt (PTB) of Germany has also been carried out with the instrument. This paper will discuss the modular design of this instrument, preliminary uncertainty analysis, results of standard source comparisons and results of solar ultraviolet measurements using the UV spectrometer with the NIST spectral irradiance field calibrator. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Thompson, A (reprint author), Natl Inst Stand & Technol, Opt Technol Div, 100 Bur Dr,Stop 8442, Gaithersburg, MD 20899 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 46 EP 55 DI 10.1117/12.364160 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800006 ER PT S AU Kelleher, DE Mohr, PJ Martin, WC Wiese, WL Sugar, J Fuhr, JR Olsen, K Musgrove, A Reader, J Sansonetti, CJ Dalton, GR AF Kelleher, DE Mohr, PJ Martin, WC Wiese, WL Sugar, J Fuhr, JR Olsen, K Musgrove, A Reader, J Sansonetti, CJ Dalton, GR BE Carruthers, GR Dymond, KF TI The new NIST Atomic Spectra Database SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE online data; atomic spectra; wavelengths; atomic energy levels; transition probabilities ID ENERGY-LEVEL CLASSIFICATIONS; TRANSITION-PROBABILITIES; AL-XIII; S-XVI; WAVELENGTHS; COMPILATION; IONIZATION; MAGNESIUM; ALUMINUM; SULFUR AB A new database has been created that makes a wealth of information on spectra, energy levels, and transition probabilities for atoms and atomic ions easily available via the World Wide Web. These data will be a valuable resource for interpretation of solar and other astrophysical spectra obtained from ground-based and space observations. Version 2.0 of the Atomic Spectra Database (ASD) is accessible on the NIST website at http://physics.nist.gov/asd. ASD provides interactive capability that allows the user to choose the element or elements of interest and the type of data to be displayed. Default formats are also available for quick viewing of the data. The database provides full search and filter capabilities. ASD contains reference data that have been critically evaluated and compiled at NIST. Version 2.0 has data for about 950 spectra and about 70,000 energy levels. There are wavelengths for about 91,000 lines from 1 Angstrom to 200 mu m, with transition probabilities and estimated uncertainties for about half of these. Energy level data are available for most ions of the elements from H (Z = 1) to Kr (Z = 36), Mo (Z = 42), as well as the first five stages of ionization of the lanthanides (Z = 57 - 71). Wavelength data are available for all elements up to Es (Z = 99). For spectra of H (Z = 1) through Ni (Z = 28) the wavelengths are accompanied by line classifications and transition probabilities. Wavelength data from recent comprehensive NIST compilations of the spectra of Mg, Al, S, Sc, Be I, O II, and Ne I are also included. For the first five spectra of other elements, wavelengths and relative intensities for prominent lines without classifications as published in Wavelengths and Transition Probabilities fop Atoms and Atomic Ions (NSRDS-NBS 68) are given. References to the NIST compilations and original data sources are listed in a bibliography. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kelleher, DE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM daniel.kelleher@nist.gov NR 35 TC 10 Z9 10 U1 2 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 170 EP 179 DI 10.1117/12.364152 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800018 ER PT S AU Griesmann, U Kling, R Burnett, JH Bratasz, L AF Griesmann, U Kling, R Burnett, JH Bratasz, L BE Carruthers, GR Dymond, KF TI The NIST FT700 Vacuum Ultraviolet Fourier Transform Spectrometer: applications in ultraviolet spectrometry and radiometry SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation II CY JUL 22, 1999 CL DENVER, CO SP SPIE, Remote Sensing Soc DE Fourier transform spectrometry; vacuum ultraviolet; radiometry; spectroscopy; refractometry ID DESIGN AB In the minds of many, Fourier transform spectrometry is restricted to applications in the infrared. In the ultraviolet the increasingly severe demands on optical, data acquisition, and motion control systems of the interferometer diminish the effectiveness of the technique. However, with recent advances in ultraviolet optics, data acquisition and sampling techniques for Fourier transform spectrometers, these stringent demands are easier to meet at vacuum ultraviolet wavelengths and significantly reduce the cost of Fourier transform spectrometers. The FT700 spectrometer at NIST can operate at wavelengths as low as 140 nm, limited by the short wavelength cut-off of the calcium fluoride optics. We illustrate the capabilities of the FT700 spectrometer in the ultraviolet with several recent results in atomic emission spectrometry, plasma diagnostics, and refractometry. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Griesmann, U (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. OI Bratasz, Lukasz/0000-0002-5277-2606 NR 12 TC 23 Z9 23 U1 0 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 0-8194-3304-7 J9 P SOC PHOTO-OPT INS PY 1999 VL 3818 BP 180 EP 188 DI 10.1117/12.364153 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BN99K UT WOS:000083801800019 ER PT S AU Albus, JS AF Albus, JS BE Gerhart, GR Gunderson, RW Shoemaker, CM TI 4-D/RCS reference model architecture for unmanned ground vehicles SO UNMANNED GROUND VEHICLE TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology CY APR 07-08, 1999 CL ORLANDO, FL SP SPIE DE intelligent control; unmanned ground vehicles; real-time control architecture; RCS; 4-D/RCS AB 4-D/RCS is the reference model architecture currently being developed for the Demo III Experimental Unmanned Vehicle program. 4-D/RCS integrates the NIST (National Institute of Standards and Technology) RCS (Real-time Control System) with the German (Universitat der Bundeswehr Munchen) VaMoRs 4-D approach to dynamic machine vision. The 4-D/RCS architecture consists of a hierarchy of computational nodes each of which contains behavior generation (BG), world modeling (WM), sensory processing (SP), and value judgment (VJ) processes. Each node also contains a knowledge database (KD) and an operator interface. These computational nodes are arranged such that the BG processes represent organizational units within a command and control hierarchy. C1 NIST, Intelligent Syst Div, Mfg Engn Lab, Gaithersburg, MD 20899 USA. RP Albus, JS (reprint author), NIST, Intelligent Syst Div, Mfg Engn Lab, Gaithersburg, MD 20899 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3167-2 J9 P SOC PHOTO-OPT INS PY 1999 VL 3693 BP 11 EP 20 DI 10.1117/12.354445 PG 10 WC Automation & Control Systems; Engineering, Civil SC Automation & Control Systems; Engineering GA BN68S UT WOS:000082586400002 ER PT B AU Mills, KL AF Mills, KL GP USENIX USENIX TI AirJava: Networking for Smart Spaces SO USENIX ASSOCIATION PROCEEDINGS OF THE WORKSHOP ON EMBEDDED SYSTEMS LA English DT Proceedings Paper CT Workshop on Embedded Systems CY MAR 29-31, 1999 CL CAMBRIDGE, MA SP USENIX Assoc, MIT Media Lab AB Increasingly people work and live on the move. To support this mobile lifestyle, especially as work becomes more intensely information-based, companies are producing various portable and embedded information devices. Concurrently, some interesting pico-cellular wireless technologies promise to outfit these portable and embedded devices with high bandwidth, localized, wireless communication capabilities that can also reach the globally wired Internet. An impressionist painting emerges of small, specialized devices roaming among islands of wireless connectivity within a global ocean of wired networks. Each wireless island becomes a "Smart Space", where available services and embedded devices can be discovered, accessed, interconnected with portable devices carried onto the island, and then the combination of imported and native devices can be exploited to support the information needs of the current island inhabitants. In this paper, I outline three specific human-information interaction challenges that the research community must address in order to reap the benefits of specialized information devices within Smart Spaces. Before these research challenges can be adequately addressed, the research community must have some Smart Spaces with which to experiment. I describe AirJava, which combines Java Jini with picocellular wireless technology to empower small devices to discover each other, to exchange programs, and to interact. While a technology like AirJava should emerge in the next five years, I propose a means of building AirJava adapters today so researchers can begin experimenting with Smart Spaces. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Mills, KL (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 USA BN 1-880446-31-6 PY 1999 BP 29 EP 34 PG 6 WC Computer Science, Cybernetics; Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BP01G UT WOS:000083829700004 ER PT S AU Hicks, BB AF Hicks, BB BE Brebbia, CA Anagnostopoulos, P TI The quantification of atmospheric deposition of nutrients, and some regulatory repercussions SO WATER POLLUTION V: MODELLING, MEASURING AND PREDICTION SE INTERNATIONAL SERIES ON PROGRESS IN WATER RESOURCES LA English DT Proceedings Paper CT 5th International Conference on Water Pollution CY MAY, 1999 CL ISL LEMNOS, GREECE SP Wessex Inst Technol, UK, Aristotle Univ Thessaloniki, Div Hydraul & Environm Engn, Greece AB The estuaries and coastal waters of eastern North America are increasingly vulnerable to the effects of atmospheric deposition, which is currently estimated to account for 20% to 40% of the total nutrient loading. Many models have been developed to assess the role of atmospheric input, but there are few measurement programs to test their predictions. Studies conducted in the watershed of the Chesapeake Bay reveal that predictions of the atmospheric deposition models most often used may require refinement, due to the need to use very fine grids when computing deposition in near-coastal waters. Moreover, classical assessments make crude assumptions regarding the retention of chemicals deposited from the air as they are transported by ground water and streamflow towards the Bay. The picture that is now widely accepted is that atmospheric deposition is highly irregular, with bursts of wet deposition modulating a more regular and much slower dry deposition input. The end result is that much of the annual atmospheric deposition loading arrives in a few short periods. If ecosystems are already stressed, then these bursts of input from the atmosphere may well have severe consequences. Research is presently under way to test this and other related hypotheses,, but in the meantime the concept of Total Maximum Daily Loads (TMDLs) is being used as a watershed-level regulatory mechanism in the United States. The TMDL approach computes the atmospheric part of the daily load as the annual input divided by 365. it is argued that a new regulatory focus must be developed, which permits consideration of the susceptibility of aquatic ecosystems to sudden intense inputs of nutrients as well as to a steady stream of pollution from continuous-emission sources. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Hicks, BB (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU WIT PRESS/COMPUTATIONAL MECHANICS PUBLICATIONS PI SOUTHAMPTON PA ASHURST LODGE, ASHURST, SOUTHAMPTON SO40 7AA, ENGLAND SN 1461-6513 BN 1-85312-685-3 J9 INT SER PROG WAT RES PY 1999 VL 1 BP 311 EP 319 PG 9 WC Water Resources SC Water Resources GA BN75K UT WOS:000082821900030 ER PT B AU Powell, MD Reinhold, TA Marshall, RD AF Powell, MD Reinhold, TA Marshall, RD BE Larsen, A Larose, GL Livesey, FM TI GPS sonde insights on boundary layer wind structure in hurricanes SO WIND ENGINEERING INTO THE 21ST CENTURY, VOLS 1-3 LA English DT Proceedings Paper CT 10th International Conference on Wind Engineering (10ICWE) CY JUN 21-24, 1999 CL COPENHAGEN, DENMARK SP Danish Maritime Inst, COWI Consulting Engineers & Planners, Monberg & Thorsen A S, Kobenhavns Kommune, Scandinavian Airlines Syst, Danish Tech Res Council, Dantec A S, MSC Nordic, COWI Fdn AB GPS sondes have been deployed into several hurricanes during the 1997 and 1998 field programs of NOAA's Hurricane Research Division. These new observing systems are described and the present knowledge of boundary layer structure in hurricanes is reviewed. GPS sondes compare favorably with in-situ observations in winds up to 32 m/s. Well-mixed layers are observed in thermodynamic quantities. However, these layers extend to different heights for temperature and moisture, suggesting separate mechanisms for turbulent and convective transport. Wind directions change very little in the lowest 100 m, suggesting the presence of a surface layer. Multiple low-level wind maxima are found below 500 m in the eyewalls of intense hurricanes. These maxima provide evidence of shallower boundary layers and surface wind speeds in excess of those diagnosed by Monin-Obukov similarity theory. These results are preliminary but may have implications for wind load provisions in building codes of countries threatened by tropical cyclones. C1 NOAA, Hurricane Res Div, Miami, FL 33149 USA. RP Powell, MD (reprint author), NOAA, Hurricane Res Div, Miami, FL 33149 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5809-059-0 PY 1999 BP 307 EP 314 PG 8 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA BN41H UT WOS:000081857400036 ER PT B AU Kihn, E Lowe, S Siquig, R Zhizhin, M AF Kihn, E Lowe, S Siquig, R Zhizhin, M BE Torres, M Sanchez, B Wills, E TI The environmental scenario generator SO WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL 8, PROCEEDINGS: CONCEPTS AND APPLICATIONS OF SYSTEMICS, CYBERNETICS AND INFORMATICS LA English DT Proceedings Paper CT World Multiconference on Systemics, Cybernetics and Informatics/5th International Conference on Information Systems, Analysis and Synthesis (ISAS 99) CY JUL 31-AUG 04, 1999 CL ORLANDO, FL SP Int Inst Informat & System, IEEE Comp Soc, Venezuela Chapter, World Org System & Cybernet, Int Federat Syst Res, Int Soc Syst Sci, Int Syst Inst, CUST, Int Inst Av Studies Syst Res & Cybernet, Soc Appl Syst Res, Cybernet & Human Knowing, Cent Univ Venezuela, Simon Bolivar Univ DE environmental science; network; distributed processor; Java; fuzzy logic AB The US Department of Defense (DoD) Modeling and Simulation (M&S) Master Plan (Under Secretary of Defense, 1995) has as an objective that the next generation of M&S programs will be able to utilize authoritative representations of the natural environment. The ability to model highly realistic representations of the environment exists today, but the ability to properly build a scenario that meets the requirements of a given simulation while still maintaining inter and intra environmental domain consistency has not yet been developed. The Environmental Scenario Generator (ESG) will automate the generation of logically integrated and physically consistent representations of the natural environment through the use of the data and modeling resources available in the Master Environmental Library (MEL). The ESG provides the ability to locate desired environmental conditions in historical data archives, and then orchestrate the production of scenario databases based on those events. The ESG is being developed as a series of intelligent Java processing modules that provide data mining and scenario production capabilities for any registered environmental data type. The services ESG provides are split into two categories: real-time and just-in-time. A design goal for the ESG system is to provide real-time interaction while the user develops a scenario specification for their simulation exercise. The real-time activities include the user's queries of the historical archives for desired conditions, the browsing of historical events that are potential matches, and the specification of the content of the desired scenario database. Once the user has defined the required content and spatial and temporal bounds of the scenario database, production of the database will take place in a just-in-time mode - meaning that user will define a required delivery time and the scenario database will be ready for delivery prior to that time. The ESG system is therefore made up of three components: a real-time server focused on data mining of historical archives, a just-in-time server focused on scenario production, and a client application that resides on the user's local system and communicates with these servers. The ESG program was started in FY-98 by the Air & Space Natural Environment (ASNE) Modeling and Simulation Executive Agent (MSEA), who provides program management for the sponsor, the Defense Modeling and Simulation Office (DMSO). The initial focus of ESG has been on atmospheric data archives and modeling capabilities. In FY-99, space and ocean data resources are being added, and in FY-00 space and ocean models and dynamic terrain data will be added to provide a fully integrated environmental scenario generation capability. C1 Natl Geophys Data Ctr, Boulder, CO 80303 USA. RP Kihn, E (reprint author), Natl Geophys Data Ctr, Boulder, CO 80303 USA. RI ZHIZHIN, Mikhail/B-9795-2014 NR 3 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA BN 980-07-5919-0 PY 1999 BP 325 EP 329 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BU36Y UT WOS:000175785400053 ER PT J AU Feely, RA Wanninkhof, R Milburn, HB Cosca, CE Stapp, M Murphy, PP AF Feely, RA Wanninkhof, R Milburn, HB Cosca, CE Stapp, M Murphy, PP TI A new automated underway system for making high precision pCO(2) measurements onboard research ships SO ANALYTICA CHIMICA ACTA LA English DT Article; Proceedings Paper CT Marine Analytical Chemistry Workshop (MARCH MOR) CY NOV 17-19, 1997 CL BREST, FRANCE DE pCO(2); underway measurements; non-dispersive infrared analysis; El Nino ID PARTIAL-PRESSURE; CO2; WATER; TEMPERATURE; SEAWATER; BUDGET AB We have developed a new temperature-controlled, automated underway system for making atmospheric and surface ocean pCO(2) measurements onboard research ships equipped with an uncontaminated seawater intake system. Uncontaminated seawater is supplied to a showerhead plexiglass equilibrator. After about 3 min, the air trapped in the equilibrator is equilibrated with seawater. This air is sampled six times per hour. In addition, atmospheric air is sampled three times per hour TM tubing to the underway system. from the intake on the bow flagstaff through 3/8 in. Dekabon(TM) tubing to the underway system. The CO2 measurements are made with a differential, non-dispersive, infrared analyzer Li-Cor(TM) (model 6252). The underway system operates on an hourly cycle with the first quarter of each hour devoted to calibration with three CO2 standards, each measured for 5 min. A second-order polynomial calibration curve is calculated from the voltage values of the standards. The remaining time in each hour is used to measure equilibrator air (15 min), bow air (15 min), and equilibrator air once again (15 min). To date, we have successfully used the underway pCO(2) system on 12 cruises of the NOAA Ship Ka'imimoana in the Equatorial Pacific. The analytical precision of the system is approximately 0.3-0.4 ppm CO2 for seawater and for air. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Feely, RA (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 13 TC 39 Z9 41 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD DEC 31 PY 1998 VL 377 IS 2-3 BP 185 EP 191 DI 10.1016/S0003-2670(98)00388-2 PG 7 WC Chemistry, Analytical SC Chemistry GA 149RM UT WOS:000077619200009 ER PT J AU Meisner, AD Collette, BB AF Meisner, AD Collette, BB TI A new species of viviparous halfbeak, Dermogenys bispina (Teleostei : Hemiramphidae) from Sabah (North Borneo) SO RAFFLES BULLETIN OF ZOOLOGY LA English DT Article DE viviparous halfbeak; new species; Dermogenys; Nomorhamphus; internal fertilization ID NOMORHAMPHUS; TESTIS; GENERA AB The genus Dermogenys Kuhl & van Hasselt in van Hasselt, 1823, is a group Of Small viviparous, atherinomorph fishes distributed throughout fresh and brackish waters of southeast Asia. Dermogenys bispina is distinguished from all other species of Dermogenys by: mature males with thick, unsegmented, dorsally curved spiculus; presence of second set of smaller spines on distal tip of spiculus; and females with melanophores directly anterior to anal fin arranged into wide U extending anteriorly, on either side of genital papilla, to level of the anus. As part of an ongoing revision of Dermogenys and the closely related nominal genus Nomorhamphus, undescribed species in both genera have been discovered. This paper describes a new species of Dermogenys, D. bispina, from Sabah (North Borneo). Results from previous histological surveys of the gonads of both males and females suggest that this new species may have a close phylogenetic relationship to populations from southern Kalimantan, Sumatra, Palawan, Culion, and the southwestern arm of Sulawesi [Sulawesi Selatan]. C1 Field Museum Nat Hist, Div Fishes, Chicago, IL 60605 USA. Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, MRC 153, Washington, DC 20560 USA. RP Meisner, AD (reprint author), Field Museum Nat Hist, Div Fishes, Roosevelt Rd & Lake Shore Dr, Chicago, IL 60605 USA. NR 16 TC 4 Z9 4 U1 0 U2 1 PU NATL UNIV SINGAPORE, SCHOOL BIOLOGICAL SCIENCES PI SINGAPORE PA DEPT ZOOLOGY, KENT RIDGE, SINGAPORE 0511, SINGAPORE SN 0217-2445 J9 RAFFLES B ZOOL JI Raffles Bull. Zool. PD DEC 30 PY 1998 VL 46 IS 2 BP 373 EP 380 PG 8 WC Zoology SC Zoology GA 158PN UT WOS:000078124100012 ER PT J AU Franzke, J Fox, RW Hollberg, L AF Franzke, J Fox, RW Hollberg, L TI Tunable UV generation at 283 nm by frequency doubling and sum frequency mixing of two semiconductor lasers for the detection of Pb SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE laser diode; second harmonic generation; sum frequency generation; lead ID SPECTROSCOPY AB High resolution atomic absorption measurements of lead at 283 nm in a vapor cell were performed by frequency doubling an 850 nm laser diode to obtain 425 nm light, followed by sum frequency generation of the harmonic radiation with a second 850 nm laser diode. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Hohenheim, Inst Phys, D-70599 Stuttgart, Germany. Natl Inst Stand & Technol, Boulder, CO USA. RP Franzke, J (reprint author), Univ Hohenheim, Inst Phys, Garbenstr 30, D-70599 Stuttgart, Germany. NR 13 TC 12 Z9 12 U1 0 U2 3 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 28 PY 1998 VL 53 IS 14 BP 1951 EP 1955 DI 10.1016/S0584-8547(98)00231-6 PG 5 WC Spectroscopy SC Spectroscopy GA 158NV UT WOS:000078122400009 ER PT J AU Erlick, C Frederick, JE Saxena, VK Wenny, BN AF Erlick, C Frederick, JE Saxena, VK Wenny, BN TI Atmospheric transmission in the ultraviolet and visible: Aerosols in cloudy atmospheres SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PHASE PHOTOCHEMICAL FORMATION; EXTENDED WATER CLOUDS; STRATIFORM CLOUDS; SOLAR-RADIATION; ANTHROPOGENIC AEROSOLS; SULFATE AEROSOLS; ELEMENTAL CARBON; AUTHENTIC CLOUD; BLACK CARBON; PARTICLES AB This study considers the effects of aerosols in cloudy atmospheres on the wavelength dependence of atmospheric transmission in the ultraviolet and visible parts of the solar spectrum. Normalizing the transmission to that of a cloud- and aerosol-free atmosphere, we examine the competing influences of clouds and aerosols on the shape of the transmission function when clouds and aerosols are mixed; while pure water clouds cause the normalized transmission to decrease with wavelength from around 320 nm through the visible, aerosol particles cause the normalized transmission to increase with wavelength from 320 nm through the visible. The results show that when clouds are superimposed on an aerosol profile with the cloud drops and aerosol particles externally mixed, the shape of the normalized transmission spectrum is dominated by the effect of the cloud drops, unless the optical depth of the aerosols begins to approach the optical depth of the cloud. This is the case for an optically thin stratus cloud and an urban aerosol profile. When cloud drops and aerosol particles are internally mixed through coagulation, the shape of the normalized transmission spectrum is again dominated by the effect of the cloud drops, unless there is an unrealistically high volume fraction of strongly absorbing aerosols embedded in the droplets. While measurements of the mass fraction of absorbing aerosols such as soot in cloud and rainwater range from 3.0 x 10(-9) to 6.9 x 10(-6), a soot volume fraction of 1 x 10(-4) is necessary to cause the normalized transmission to increase with wavelength from 320 nm through the visible. The model results are also shown to be consistent with Brewer spectrophotometer irradiance measurements under cloudy and hazy conditions. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Princeton Univ, Geophys Fluid Dynam Lab, Forrestal Campus,Route 1, Princeton, NJ 08542 USA. EM cee@gfdl.gov; frederic@rainbow.uchicago.edu; sax-ena@eos.ncsu.edu; bnwenny@eos.ncsu.edu NR 71 TC 28 Z9 28 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 1998 VL 103 IS D24 BP 31541 EP 31555 DI 10.1029/1998JD200053 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VL UT WOS:000077967000003 ER PT J AU Kaufman, YJ Hobbs, PV Kirchhoff, VWJH Artaxo, P Remer, LA Holben, BN King, MD Ward, DE Prins, EM Longo, KM Mattos, LF Nobre, CA Spinhirne, JD Ji, Q Thompson, AM Gleason, JF Christopher, SA Tsay, SC AF Kaufman, YJ Hobbs, PV Kirchhoff, VWJH Artaxo, P Remer, LA Holben, BN King, MD Ward, DE Prins, EM Longo, KM Mattos, LF Nobre, CA Spinhirne, JD Ji, Q Thompson, AM Gleason, JF Christopher, SA Tsay, SC TI Smoke, Clouds, and Radiation - Brazil (SCAR-B) experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID TROPICAL SOUTH-ATLANTIC; ATMOSPHERIC CHEMISTRY; SPECTRAL RADIANCES; SATELLITE IMAGERY; SULFATE AEROSOLS; FIELD EXPERIMENT; LAND SURFACES; SAVANNA FIRES; DRY SEASON; BIOMASS AB The Smoke, Clouds, and Radiation-Brazil (SCAR-B) field project took place in the Brazilian Amazon and cerrado regions in August-September 1995 as a collaboration between Brazilian and American scientists. SCAR-B, a comprehensive experiment to study biomass burning, emphasized measurements of surface biomass, fires, smoke aerosol and trace gases, clouds, and radiation, their climatic effects, and remote sensing from aircraft and satellites. It included aircraft and ground-based in situ measurements of smoke emission factors and the compositions, sizes, and optical properties of the smoke particles; studies of the formation of ozone; the transport and evolution of smoke; and smoke interactions with water vapor and clouds. This overview paper introduces SCAR-B and summarizes some of the main results obtained so far. (1) Fires: measurements of the size distribution of fires, using the 50 m resolution MODIS Airborne Simulator, show that most of the fires are small (e.g., 0.005 km(2)), but the satellite sensors (e.g., AVHRR and MODIS with 1 km resolution) can detect fires in Brazil which are responsible for 60-85% of the burned biomass; (2) Aerosol: smoke particles emitted from fires increase their radius by as much as 60% during their first three days in the atmosphere due to condensation and coagulation, reaching a mass median radius of 0.13-0.17 mu m; (3) Radiative forcing: estimates of the globally averaged direct radiative forcing due to smoke worldwide, based on the properties of smoke measured in SCAR-B (-0.1 to -0.3 W m(-2)), are smaller than previously modeled due to a lower single-scattering albedo (0.8 to 0.9), smaller scattering efficiency (3 m(2) g(-1) at 550 nm), and low humidification factor; and (4) Effect on clouds: a good relationship was found between cloud condensation nuclei and smoke volume concentrations, thus an increase in the smoke emission is expected to affect cloud properties. In SCAR-B, new techniques were developed for deriving the absorption and refractive index of smoke from ground-based remote sensing. Future spaceborne radiometers (e.g., MODIS on the Earth Observing System), simulated on aircraft, proved to be very useful for monitoring smoke properties, surface properties, and the impacts of smoke on radiation and climate. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Earth Sci Directorate, Greenbelt, MD 20771 USA. Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, Brazil. NOAA, NESDIS, ORA, Madison, WI 53706 USA. US Forest Serv, Intermt Res Stn, Missoula, MT 59807 USA. RP NASA, Goddard Space Flight Ctr, Atmospheres Lab, Mail Code 913, Greenbelt, MD 20771 USA. EM kaufman@climate.gsfc.nasa.gov RI King, Michael/C-7153-2011; Christopher, Sundar/E-6781-2011; Gleason, James/E-1421-2012; Tsay, Si-Chee/J-1147-2014; Artaxo, Paulo/E-8874-2010; Thompson, Anne /C-3649-2014 OI King, Michael/0000-0003-2645-7298; Artaxo, Paulo/0000-0001-7754-3036; Thompson, Anne /0000-0002-7829-0920 NR 102 TC 216 Z9 219 U1 2 U2 35 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 1998 VL 103 IS D24 BP 31783 EP 31808 DI 10.1029/98JD02281 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VL UT WOS:000077967000021 ER PT J AU Prins, EM Feltz, JM Menzel, WP Ward, DE AF Prins, EM Feltz, JM Menzel, WP Ward, DE TI An overview of GOES-8 diurnal fire and smoke results for SCAR-B and 1995 fire season in South America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SATELLITE DATA; TROPOSPHERIC OZONE; DRY-SEASON; BIOMASS; AEROSOLS; TROPICS; IMPACT; AMAZON AB The launch of the eighth Geostationary Operational Environmental Satellite (GOES-8) in 1994 introduced an improved capability for diurnal fire and smoke monitoring throughout the western hemisphere. In South America the GOES-8 automated biomass burning algorithm (ABBA) and the automated smoke/aerosol detection algorithm (ASADA) are being used to monitor biomass burning. This paper outlines GOES-8 ABBA and ASADA development activities and summarizes results for the Smoke, Clouds, and Radiation in Brazil (SCAR-B) experiment and the 1995 fire season. GOES-8 ABBA results document the diurnal, spatial, and seasonal variability in fire activity throughout South America. A validation exercise compares GOES-8 ABBA results with ground truth measurements for two SCAR-B prescribed burns. GOES-8 ASADA aerosol coverage and derived albedo results provide an overview of the extent of daily and seasonal smoke coverage and relative intensities. Day-to-day variability in smoke extent closely tracks fluctuations in fire activity. C1 Univ Wisconsin, NOAA, NESDIS, ORA,ASPT, Madison, WI 53706 USA. Univ Wisconsin, CIMSS, Madison, WI 53706 USA. US Forest Serv, Intermt Res Stn, Missoula, MT 59807 USA. RP Univ Wisconsin, NOAA, NESDIS, ORA,ASPT, 1225 W Dayton St, Madison, WI 53706 USA. EM elaine.prins@ssec.wisc.edu RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 32 TC 156 Z9 161 U1 2 U2 7 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 1998 VL 103 IS D24 BP 31821 EP 31835 DI 10.1029/98JD01720 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VL UT WOS:000077967000023 ER PT J AU Ackerman, SA Strabala, KI Menzel, WP Frey, RA Moeller, CC Gumley, LE AF Ackerman, SA Strabala, KI Menzel, WP Frey, RA Moeller, CC Gumley, LE TI Discriminating clear sky from clouds with MODIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OCTOBER 1986 FIRE; WATER-VAPOR BAND; MU-M; AVHRR DATA; SPECTROMETER; RADIANCES; AEROSOL; WINDOW; ISCCP; VEGETATION AB The MODIS cloud mask uses several cloud detection tests to indicate a level of confidence that the MODIS is observing clear skies. It will be produced globally at single-pixel resolution; the algorithm uses as many as 14 of the MODIS 36 spectral bands to maximize reliable cloud detection and to mitigate past difficulties experienced by sensors with coarser spatial resolution or fewer spectral bands. The MODIS cloud mask is ancillary input to MODIS land, ocean, and atmosphere science algorithms to suggest processing options. The MODIS cloud mask algorithm will operate in near real time in a limited computer processing and storage facility with simple easy-to-follow algorithm paths. The MODIS cloud mask algorithm identifies several conceptual domains according to surface type and solar illumination, including land, water, snow/ice, desert, and coast for both day and night. Once a pixel has been assigned to a particular domain (defining an algorithm path), a series of threshold tests attempts to detect the presence of clouds in the instrument field of view. Each cloud detection test returns a confidence level that the pixel is clear ranging in value from 1 (high) to zero (low). There are several types of tests, where detection of different cloud conditions relies on different tests. Tests capable of detecting similar cloud conditions are grouped together. While these groups are arranged so that independence between them is maximized, few, if any, spectral tests are completely independent. The minimum confidence from all tests within a group is taken to be representative of that group. These confidences indicate absence of particular cloud types. The product of all the group confidences is used to determine the confidence of finding clear-sky conditions. This paper outlines the MODIS cloud masking algorithm. While no present sensor has all of the spectral bands necessary for testing the complete MODIS cloud mask, initial validation of some of the individual cloud tests is presented using existing remote sensing data sets. C1 Univ Wisconsin, Space Sci & Engn Ctr, CIMSS, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. Univ Wisconsin, NOAA, NESDIS, Adv Satellite Prod Team, Madison, WI 53706 USA. RP Univ Wisconsin, Space Sci & Engn Ctr, CIMSS, Dept Atmospher & Ocean Sci, 1225 W Dayton St, Madison, WI 53706 USA. EM paul.menzel@ssec.wisc.edu RI Menzel, W. Paul/B-8306-2011; Ackerman, Steven/G-1640-2011 OI Menzel, W. Paul/0000-0001-5690-1201; Ackerman, Steven/0000-0002-4476-0269 NR 38 TC 516 Z9 541 U1 7 U2 66 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 1998 VL 103 IS D24 BP 32141 EP 32157 DI 10.1029/1998JD200032 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VL UT WOS:000077967000049 ER PT J AU Kaufman, YJ Justice, CO Flynn, LP Kendall, JD Prins, EM Giglio, L Ward, DE Menzel, WP Setzer, AW AF Kaufman, YJ Justice, CO Flynn, LP Kendall, JD Prins, EM Giglio, L Ward, DE Menzel, WP Setzer, AW TI Potential global fire monitoring from EOS-MODIS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SATELLITE DETECTION; SAVANNA ECOSYSTEMS; WATER-VAPOR; DATA SET; BIOMASS; AEROSOL; SMOKE; RESOLUTION; IDENTIFICATION; EMISSIONS AB The National Aeronautic and Space Administration (NASA) plans to launch the moderate resolution imaging spectroradiometer (MODIS) on the polarorbiting Earth Observation System (EOS) providing morning and evening global observations in 1999 and afternoon and night observations in 2000. These four MODIS daily fire observations will advance global fire monitoring with special 1 km resolution fire channels at 4 and 11 rim with high saturation of about 450 and 400 K, respectively. MODIS data will also be used to monitor burn scars, vegetation type and condition, smoke aerosols, water vapor, and clouds for overall monitoring of the fire process and its effets on ecosystems, the atmosphere, and the climate. The MODIS fire science team is preparing algorithms that use the thermal signature to separate the fire signal from the background signal. A database of active fire products will be generated and archived at a 1 km resolution and summarized on a grid of 10 km and 0.5 degrees, daily, 8 days, and monthly. It includes the fire occurrence and location, the rate of emission of thermal energy from the fire, and a rough estimate of the smoldering/flaming ratio.. This information will be used in monitoring the spatial and temporal distribution of fires in different ecosystems, detecting changes in fire distribution and identifying new fire frontiers, wildfires, and changes in the frequency of the fires or their relative strength. We plan to combine the MODIS fire measurements with a detailed diurnal cycle of the fires from geostationary satellites. Sensitivity studies and analyses of aircraft and satellite data from the Yellowstone wildfire of 1988 and prescribed fires in the Smoke, Clouds, and Radiation (SCAR) aircraft field experiments are used to evaluate and validate the fire algorithms and to establish the relationship between the fire thermal properties, the rate of biomass consumption, and the emissions of aerosol and trace gases from fires. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Univ Hawaii, Hawaii Inst Geophys & Planets, Honolulu, HI 96822 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. US Forest Serv, Intermt Res Stn, USDA, Missoula, MT USA. NOAA, NESDIS, Madison, WI 53706 USA. Inst Pesquisas Espaciais, Sao Paulo, Brazil. RP NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. EM justice@kratmos.gsfc.nasa.gov RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 83 TC 270 Z9 292 U1 4 U2 37 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 1998 VL 103 IS D24 BP 32215 EP 32238 DI 10.1029/98JD01644 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VL UT WOS:000077967000054 ER PT J AU Williams, AB Hernandez-Aguilera, JL AF Williams, AB Hernandez-Aguilera, JL TI A new species of mud shrimp, Upogebia toralae, from Veracruz, Mexico (Decapoda : Thalassinidea : Upogebiidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Upogebia toralae, a new species of mud shrimp from Veracruz, Mexico is described and illustrated. The unique female holotype was collected intertidally in the Port of Veracruz which is strongly impacted by human activity. The species shares with many members of the genus from the western hemisphere a strongly developed proximal mesioventral spine on the merus of the second pereopod. The species stands alone, however, with respect to other characters. The triangular rostrum has no ventral spines, the anterior gastric region bears many anteriorly setose spines that art more or less transversely elongate and scalelike, and the palms of the chelae have a dorsal ridge that bears three erect and somewhat hooked spines on its proximal end. C1 Smithsonian Inst, Museum Natl Hist Nat, Natl Marine Fisheries Serv Systemat Lab, Washington, DC 20560 USA. Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Mexico City 04510, DF, Mexico. RP Williams, AB (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Natl Marine Fisheries Serv Systemat Lab, Washington, DC 20560 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD DEC 23 PY 1998 VL 111 IS 4 BP 908 EP 911 PG 4 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 154JX UT WOS:000077886700017 ER PT J AU Richards, WJ McCosker, JE AF Richards, WJ McCosker, JE TI A new species of the genus Bellator (Pisces : Triglidae), with comments on the trigloids of the Galapagos Islands SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new, endemic species, Bellator farrago, is described from the Galapagos Islands. It differs from its congeners by a combination of characters including absence of a supplemental preopercular spine, short first dorsal fin spine, produced rostral spines, and lack of scales on the breast and interpelvic area. The Galapagos trigloid fauna comprises: B. farrago, Prionotus miles, Pr. stephanophrys, and Peristedion crustosum. C1 NOAA Fisheries, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Calif Acad Sci, San Francisco, CA 94118 USA. RP Richards, WJ (reprint author), NOAA Fisheries, SE Fisheries Sci Ctr, 75 Virginia Beach Dr, Miami, FL 33149 USA. NR 5 TC 4 Z9 5 U1 0 U2 4 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD DEC 23 PY 1998 VL 111 IS 4 BP 936 EP 941 PG 6 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 154JX UT WOS:000077886700022 ER PT J AU Subbanna, H Kokil, S Kapur, PC Pradip Malghan, SG AF Subbanna, H Kokil, S Kapur, PC Pradip Malghan, SG TI An aggregation index for monitoring the state of the suspensions SO LANGMUIR LA English DT Article ID ANIONIC POLYELECTROLYTES; CERAMIC MATERIALS; SILICON-NITRIDE; PARTICLE-SIZE; YIELD STRESS; POWDER; ALUMINA; FORCES AB The state of aggregation in alumina, zirconia, and mixed alumina-zirconia suspensions is determined by particle size analysis of particles/aggregates in suspensions. An aggregation index is derived using principal component analysis of the size distribution data. The first principal component is shown to be an adequate single-value measure of the extent of aggregation in the suspension. Aggregation indices are obtained for suspensions prepared at different pH with and without the addition of different polymeric surfactants of varying dosage and molecular weight and employed for analyzing the state of the suspensions. C1 Tata Res Dev & Design Ctr, Pune 411013, Maharashtra, India. NIST, Gaithersburg, MD 20899 USA. RP Pradip (reprint author), Tata Res Dev & Design Ctr, Pune 411013, Maharashtra, India. NR 35 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 22 PY 1998 VL 14 IS 26 BP 7364 EP 7370 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 151UH UT WOS:000077738700010 ER PT J AU Mitev, P Seshadri, S Guido, LJ Schaafsma, DT Christensen, DH AF Mitev, P Seshadri, S Guido, LJ Schaafsma, DT Christensen, DH TI Cation vacancy formation and migration in the AlGaAs heterostructure system SO APPLIED PHYSICS LETTERS LA English DT Article ID POINT-DEFECTS; DIFFUSION; GAAS; INTERDIFFUSION; ENERGIES; DEPTH AB A simple experimental approach has been employed to obtain thermochemical parameters for cation vacancy formation and migration in the AlGaAs heterostructure system. Cation vacancies are injected into the free surface by annealing under an arsenic-rich ambient. Their presence is detected by monitoring the local rate of Al-Ga interdiffusion at imbedded quantum well markers. The sample is unusually thick allowing us to separately identify contributions from the vapor, epilayer, and substrate phases. The entropies and enthalpies of vacancy formation and migration are (5.2 +/- 5.7) k(B) and (1.8 +/- 0.5) eV and (11.3 +/- 4.4) k(B) and (3.3 +/- 0.4) eV, respectively. (C) 1998 American Institute of Physics. [S0003-6951(98)02051-8]. C1 Yale Univ, New Haven, CT 06520 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Guido, LJ (reprint author), Yale Univ, New Haven, CT 06520 USA. EM louis.guido@yale.edu NR 17 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 21 PY 1998 VL 73 IS 25 BP 3718 EP 3720 DI 10.1063/1.122874 PG 3 WC Physics, Applied SC Physics GA 146XH UT WOS:000077458200031 ER PT J AU Young, M AF Young, M TI Mode-field diameter of single-mode optical fiber by far-field scanning (vol 37, pg 5605, 1998) SO APPLIED OPTICS LA English DT Correction C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Young, M (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. NR 1 TC 5 Z9 5 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1998 VL 37 IS 36 BP 8361 EP 8361 DI 10.1364/AO.37.008361 PG 1 WC Optics SC Optics GA 150XA UT WOS:000077690300010 PM 18301660 ER PT J AU Brown, JM Korsgen, H Evenson, KM AF Brown, JM Korsgen, H Evenson, KM TI Fe+ in its ground D-6 state: A direct measurement of the J = 1/2-3/2 and J = 3/2-5/2 fine-structure intervals SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; infrared : general; line : identification; methods : laboratory ID LASER MAGNETIC-RESONANCE; SPECTRUM; IRON AB The J=1/2-3/2 and 3/2-5/2 fine-structure transitions in the atomic ion Fe+ in its ground D-6 State have been detected in the laboratory by far-infrared laser magnetic resonance at 87 and 51 mu m. The fine-structure intervals have been measured accurately by extrapolation to zero magnetic field as 3430.7762 (19) and 5843.7984 (12) GHz, respectively. C1 Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Brown, JM (reprint author), Phys & Theoret Chem Lab, S Parks Rd, Oxford OX1 3QZ, England. NR 17 TC 3 Z9 3 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1998 VL 509 IS 2 BP 927 EP 930 DI 10.1086/306539 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DH UT WOS:000079250700040 ER PT J AU Lynn, JW AF Lynn, JW TI Spin dynamics of magnetoresistive oxides SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 1st International Conference on New Theories, Discoveries, and Applications of Superconductors and Related Materials (New3SC-1) CY FEB 19-24, 1998 CL BATON ROUGE, LOUISIANA ID LA1-XCAXMNO3; FERROMAGNET AB A review is given of the neutron scattering measurements of the spin dynamics of the magnetoresistive oxides. A number of anomalous features have been identified in the manganites, including very strong damping of the spin waves in the ground state and as a function of temperature, anomalous spin wave dispersion and the development of a strong spin-diffusion component to the fluctuation spectrum well below T-C in the region of optimal doping. For the Tl2Mn2O7 pyrochlore, on the other hand, the behavior of the spin dynamics is conventional, which argues that the mechanism responsible for the magnetoresistive effect has a different origin in these two classes of materials. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Lynn, JW (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 20 PY 1998 VL 12 IS 29-31 BP 3355 EP 3358 DI 10.1142/S0217979298002635 PG 4 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 175UT UT WOS:000079114500093 ER PT J AU Jaffrezo, JL Davidson, CI Kuhns, HD Bergin, MH Hillamo, R Maenhaut, W Kahl, JW Harris, JM AF Jaffrezo, JL Davidson, CI Kuhns, HD Bergin, MH Hillamo, R Maenhaut, W Kahl, JW Harris, JM TI Biomass burning signatures in the atmosphere of central Greenland SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GISP2 ICE CORE; CARBOXYLIC-ACIDS; TRACE-ELEMENTS; ORGANIC-ACIDS; DICARBOXYLIC-ACIDS; SIZE DISTRIBUTION; DRY DEPOSITION; FOREST-FIRES; AEROSOL SIZE; SUMMIT AB Daily atmospheric concentrations of particulate oxalate measured at the Summit of the Greenland Ice Sheet are presented for the summers 1992 - 1995. We believe that four episodes of elevated concentrations are due to biomass burning plumes passing over the site. In at least two cases the source regions of the fires are located in northern Canada. Further characteristics of the aerosol are examined during one of these events. A large increase of particle number concentrations in the accumulation mode can be observed, while the increase is much more limited for total particle number, The suite of chemical species enriched in the aerosol includes typical biomass burning tracers like fine K, large concentrations of ammonium, particulate formate and acetate, as well as other organic species like glycolate. The size distributions of K, oxalate, and glycolate are skewed toward the accumulation mode and exhibit the very same shape as sulfate, suggesting internal mixing of these species in the same particles. Molar ratios S/K indicate incorporation of S during transport, most probably by production of sulfate, Concentrations of these species were measured in fog samples for radiative events that occurred during the plume passage. There is a good agreement in the relative variation of concentrations between the aerosol and fog for oxalate and glycolate, while the gas phase probably dominates incorporation in the fog droplets for acetate, formate, chloride, nitrate, and sulfate (incorporated as SO2, which is further oxidized), The complexity of the transfer of the organic acids from the atmosphere to fog is underlined. C1 Lab Glaciol & Geophys Environm, F-38402 St Martin Dheres, France. Georgia Inst Technol, Dept Civil & Environm Engn, Atlanta, GA 30332 USA. Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Finnish Meteorol Inst, FIN-00810 Helsinki, Finland. Univ Wisconsin, Dept Geosci, Milwaukee, WI 53211 USA. Inst Nucl Sci, B-9000 Ghent, Belgium. RP Jaffrezo, JL (reprint author), Lab Glaciol & Geophys Environm, Domaine Univ,BP 96, F-38402 St Martin Dheres, France. EM jlj@glaciog.ujf-grenoble.fr RI Kuhns, Hampden/C-3563-2008; Maenhaut, Willy/M-3091-2013 OI Maenhaut, Willy/0000-0002-4715-4627 NR 59 TC 35 Z9 36 U1 0 U2 8 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 1998 VL 103 IS D23 BP 31067 EP 31078 DI 10.1029/98JD02241 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 154GM UT WOS:000077880800003 ER PT J AU Olszyna, KJ Parkhurst, WJ Meagher, JF AF Olszyna, KJ Parkhurst, WJ Meagher, JF TI Air chemistry during the 1995 SOS/Nashville intensive determined from level 2 network SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; RURAL SITE; OZONE; HNO3 AB Air quality measurements from enhanced ground-based air monitoring stations, that were located at strategic urban, suburban, and rural (regional) locations, were used to determine the factors controlling excess ozone formation in the Nashville area. During the 6 week intensive study period, the daily maximum hourly O-3 concentrations varied from daytime highs of less than 40 ppbv to values exceeding 120 ppbv. The higher O-3 concentrations were observed at the urban and suburban locations, and the highest O-3 value of 138 ppbv was observed at the downtown Nashville station. On 12 days, one or more of the urban and suburban stations exceeded midday; 8-hour mean O-3 concentrations of 80 ppbv in contrast to the single occurrence at the rural stations. The observations that the elevated O-3 concentrations occurred more frequently at the urban and suburban stations during stagnating weather conditions suggest localized production of excess O-3. The comparison of the O-3/NOy ratios to model simulations suggest that the rural and suburban locations are in a NOx sensitive chemistry regime, while the urban location (downtown Nashville) is in a chemistry regime that is sensitive to both NOx and VOC concentrations. The O-3 production efficiency, determined from the slope of the O-3 versus NOz (NOy - NOx), nas found to be similar between the Dickson and Youth suburban stations and the Giles rural/regional station. The segregation of the data by SO2 concentration showed lower O-3 production efficiency for those measurement periods with SO2 concentrations greater than 2 ppbv. The slopes (upper limits of O-3 production efficiency) ranged from 7.7 to 10.6 for the lower SO2 concentrations and from 4.4 to 4.6 for the higher SO2 concentrations. C1 Tennessee Valley Author, Atmospher Sci & Environm Assessments, Muscle Shoals, AL 35662 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Olszyna, KJ (reprint author), Tennessee Valley Author, Atmospher Sci & Environm Assessments, POB 1010,CEB 2A, Muscle Shoals, AL 35662 USA. EM kjolszyna@tva.gov NR 18 TC 13 Z9 13 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 1998 VL 103 IS D23 BP 31143 EP 31153 DI 10.1029/1998JD100038 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 154GM UT WOS:000077880800010 ER PT J AU Alvarez, RJ Senff, CJ Hardesty, RM Parrish, DD Luke, WT Watson, TB Daum, PH Gillani, N AF Alvarez, RJ Senff, CJ Hardesty, RM Parrish, DD Luke, WT Watson, TB Daum, PH Gillani, N TI Comparisons of airborne lidar measurements of ozone with airborne in situ measurements during the 1995 Southern Oxidants Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC OZONE; DIAL MEASUREMENTS; AEROSOL PROFILES; SYSTEM; RANGE AB As part of the 1995 Southern Oxidants Study (SOS), the National Oceanic and Atmospheric Administration airborne ozone lidar was deployed during June and July to provide detailed three-dimensional lower tropospheric ozone distribution information in the Nashville, Tennessee, area. The airborne portion of the study included six aircraft instrumented with an assortment of in situ and remote sensors. Results of comparisons between the ozone values obtained using the lidar and the values obtained using in situ instrumentation aboard other aircraft are presented. High resolution (90 m vertical and 520 m horizontal corresponding to 8 s at a flight speed of 65 m/s) was maintained during the analysis of the lidar data which caused statistical variations in the calculated ozone concentrations from 3 ppbv (5% for typical ozone concentrations encountered during the study) at a range of 1500 m from the lidar to 11 ppbv (17%) at a range of 2500 m from the lidar. However, the lidar ozone concentration measurements compare favorably with the in situ values, with the average offset less than 10 ppbv (16%) for each flight, and the average magnitude of the offsets over all the flights at 4.3 ppbv (7%). C1 NOAA, ETL, MS, Environm Res Lab, Boulder, CO 80303 USA. US DOE, Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Alabama, Earth Syst Sci Lab, Huntsville, AL 35899 USA. NOAA, ERL, Air Resources Lab, Silver Spring, MD 20910 USA. NOAA, Aeron Lab, ERL, Boulder, CO 80303 USA. NOAA, ERL, Air Resources Lab, Idaho Falls, ID 83401 USA. RP Alvarez, RJ (reprint author), NOAA, ETL, MS, Environm Res Lab, 325 Broadway,R-E-ET2, Boulder, CO 80303 USA. EM ralvarez@ctl.noaa.gov RI Parrish, David/E-8957-2010; Hardesty, Robert/H-9844-2013; Senff, Christoph/I-2592-2013; Alvarez, Raul/I-4879-2013; Luke, Winston/D-1594-2016 OI Parrish, David/0000-0001-6312-2724; Luke, Winston/0000-0002-1993-2241 NR 24 TC 18 Z9 18 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 1998 VL 103 IS D23 BP 31155 EP 31171 DI 10.1029/98JD02745 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 154GM UT WOS:000077880800011 ER PT J AU Senff, CJ Hardesty, RM Alvarez, RJ Mayor, SD AF Senff, CJ Hardesty, RM Alvarez, RJ Mayor, SD TI Airborne lidar characterization of power plant plumes during the 1995 Southern Oxidants Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE; PROFILES; AEROSOLS AB One of the objectives of the 1995 Southern Oxidants Study was to assess the extent to which fossil fuel power plants contribute to high ozone episodes that often occur in the Nashville area during summer. Among other instruments, the National Oceanic and Atmospheric Administration airborne ozone and aerosol lidar was used to investigate power plant plumes in the vicinity of Nashville, Tennessee. Owing to its ability to characterize the two-dimensional structure of ozone and aerosols below the aircraft, the airborne lidar is well suited to document the evolution of the size and shape of a power plant plume as well as its impact on ozone concentration levels as the plume is advected downwind. We report on two case studies of the Cumberland power plant plume that were conducted on July 7 and 19, 1995. The meteorological conditions on these 2 days were distinctly different and had a significant impact on the plume characteristics. On July 7, the Cumberland plume was shaped symmetrically and confined to the boundary layer, while on July 19 the plume had an irregular shape and showed two cores, one above and the other within the boundary layer. Close to the Cumberland power plant, we found that ozone in the plume was destroyed at a rate of 5 to 8 ppbv h(-1) due to titration at high NO levels. Farther downwind, where plume NOx reacts with ozone precursor gases to form ozone, we measured plume-averaged ozone production rates of 1.5 to 4 ppbv h(-1). The results of these two case studies are compared to aircraft in situ measurements of the same power plant plume. C1 NOAA, ERL, ETL, Boulder, CO 80303 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NCAR, Atmospher Technol Div, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Senff, CJ (reprint author), NOAA, ERL, ETL, 325 Broadway,R-E-ET2, Boulder, CO 80303 USA. EM csenff@ctl.noaa.gov RI Hardesty, Robert/H-9844-2013; Senff, Christoph/I-2592-2013; Alvarez, Raul/I-4879-2013 NR 16 TC 16 Z9 16 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 20 PY 1998 VL 103 IS D23 BP 31173 EP 31189 DI 10.1029/98JD02625 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 154GM UT WOS:000077880800012 ER PT J AU Langford, AO Reid, SJ AF Langford, AO Reid, SJ TI Dissipation and mixing of a small-scale stratospheric intrusion in the upper troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; TROPOPAUSE FOLD; POTENTIAL VORTICITY; GRAVITY-WAVE; OZONE; LIDAR; EXCHANGE; SYSTEM; TRANSPORT; HUMIDITY AB Ground-based lidar measurements of ozone mixing ratio and aerosol backscatter profiles above Fritz Peak Observatory near Boulder, Colorado (39.9 degrees N, 105.3 degrees W), are used in conjunction with nearby radiosonde profiles and GOES-9 satellite water vapor imagery to describe the mixing of a dry, ozone-rich streamer of stratospheric air into the upper troposphere over the western United States on June 30 and July 1, 1997. The satellite images show that the streamer extended over more than 2000 km from the eastern Pacific Ocean to the central United States beneath the subtropical jet with a width of similar to 200 km over Colorado. The streamer persisted with little change for more than 6 hours of lidar observations and then abruptly disappeared to be replaced by a region of unusually low ozone. The disappearance of the streamer is attributed to localized convective activity induced by the incursion of a moist, ozone-poor subtropical air mass between the streamer and the convective boundary layer. This activity disrupted the streamer and, together with shear-induced mixing beneath the descending subtropical jet, merged similar to 6.5 x 10(31) molecules of ozone into the free troposphere over Colorado between 8 and 10 km. These results illustrate the effectiveness of small-scale processes for the irreversible transfer of stratospheric air into the upper troposphere. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Langford, AO (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM langford@al.noaa.gov RI Langford, Andrew/D-2323-2009 OI Langford, Andrew/0000-0002-2932-7061 NR 34 TC 27 Z9 27 U1 1 U2 8 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 1998 VL 103 IS D23 BP 31265 EP 31276 DI 10.1029/98JD02596 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 154GM UT WOS:000077880800019 ER PT J AU Braun, RJ Cahn, JW McFadden, GB Rushmeier, HE Wheeler, AA AF Braun, RJ Cahn, JW McFadden, GB Rushmeier, HE Wheeler, AA TI Theory of anisotropic growth rates in the ordering of an FCC alloy SO ACTA MATERIALIA LA English DT Article ID PHASE-FIELD MODEL; DENDRITIC GROWTH; CRYSTAL-GROWTH; MELT INTERFACE; BINARY-ALLOYS AB A multiple-order-parameter theory of ordering on a binary face-centrsd-cubic (f.c.c.) crystal lattice is used to model diffuse interphase boundaries and provide expressions for the anisotropy of the kinetic coefficient that characterizes the speed of the order-disorder boundary. The anisotropy is varied parametrically with the ratio of two gradient energy coefficients. In contrast to the results from single-order-parameter theories, the orientation dependence of the kinetic coefficient differs significantly from that of the surface energy. Although the interfacial free energy anisotropy from this model is nor strong enough ro eliminate ally orientations in the (three-dimensional) equilibrium shapes, the kinetic coefficient is sufficiently anisotropic to eliminate some orientations during growth. The long-time kinetic growth shapes show the development of edges and corners in a definite sequence as the anisotropy increases. (C) 1997 Acta Metallurgica Inc. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Delaware, Dept Math Sci, Newark, DE 19716 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. Univ Southampton, Fac Math Studies, Southampton SO9 5NH, Hants, England. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 43 TC 19 Z9 19 U1 0 U2 11 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 19 PY 1998 VL 46 IS 1 BP 1 EP 12 DI 10.1016/S1359-6454(97)00236-X PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YQ444 UT WOS:000071388100001 ER PT J AU Schwarz, JP Robertson, DS Niebauer, TM Faller, LE AF Schwarz, JP Robertson, DS Niebauer, TM Faller, LE TI A free-fall determination of the Newtonian constant of gravity SO SCIENCE LA English DT Article ID GRAVITATIONAL CONSTANT AB Recent determinations of the Newtonian constant of gravity have produced values that differ by nearly 40 times their individual error estimates (more than 0.5%). In an attempt to help resolve this situation, an experiment that uses the gravity field of a one-half metric ton source mass to perturb the trajectory of a free-falling mass and laser interferometry to track the falling object was performed. This experiment does not suspend the test mass from a support system. It is therefore free of many systematic errors associated with supports. The measured value was G = (6.6873 +/- 0.0094) x 10(-11) m(3) kg(-1) sec(-2). C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. NOAA, NOS, Natl Geodet Survey, Boulder, CO 80309 USA. CIRES, Boulder, CO 80309 USA. Colorado Sch Mines, Dept Geophys, Golden, CO 80401 USA. RP Schwarz, JP (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI schwarz, joshua/G-4556-2013 OI schwarz, joshua/0000-0002-9123-2223 NR 22 TC 40 Z9 43 U1 0 U2 2 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 18 PY 1998 VL 282 IS 5397 BP 2230 EP 2234 DI 10.1126/science.282.5397.2230 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 150CR UT WOS:000077645800038 ER PT J AU Dalluge, JJ Sander, LC AF Dalluge, JJ Sander, LC TI Precolumn affinity capillary electrophoresis for the identification of clinically relevant proteins in human serum: Application to human cardiac troponin I SO ANALYTICAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; ONLINE; PRECONCENTRATION; ELECTROCHROMATOGRAPHY; CHROMATOGRAPHY; EXTRACTION; TECHNOLOGY; DIAGNOSIS; MECHANISM AB An approach has been developed to the on-line extraction and identification of clinical disease-state marker proteins in human serum. Fabrication of capillaries with integral packed beds for the online determination of human cardiac troponin I (cTnI), a diagnostic marker for myocardial infarction, at clinically relevant levels (2 mmol/L) in serum is demonstrated, The technique, termed precolumn affinity capillary electrophoresis (PA-CE), utilizes a short (similar to 5 mm) packed bed of porous silica containing covalently immobilized monoclonal anti-cTnI antibodies directly integrated within a separation capillary for the selective retention of cTnI from a complex matrix. Following a rinsing step to eliminate nonspecifically bound serum proteins and other impurities from the column, desorption of the antigen into the separation region of the PA-CE capillary for subsequent measurement of femtomolar amounts of cTnI by CE is effected by the injection of an appropriate elution buffer. Advantages of this approach over previously reported affinity preconcentration techniques, related applications for PA-CE technology, and its potential for use in the development of a certified reference material for cTnI in serum are discussed. C1 Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Dalluge, JJ (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 16 TC 22 Z9 23 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 1998 VL 70 IS 24 BP 5339 EP 5343 DI 10.1021/ac980773u PG 5 WC Chemistry, Analytical SC Chemistry GA 148TY UT WOS:000077550100033 PM 9868922 ER PT J AU Anderson, DT Schuder, M Nesbitt, DJ AF Anderson, DT Schuder, M Nesbitt, DJ TI Large-amplitude motion in highly quantum clusters: high-resolution infrared absorption studies of jet-cooled H-2-HCl and H-2-DCl SO CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL PREDISSOCIATION; ROTATIONAL PREDISSOCIATION; VANDERWAALS COMPLEXES; D2HF; SPECTROSCOPY; H2HF; HCL; CALIBRATION; SPECTRUM AB High-resolution infrared spectroscopy is used to interrogate a series of inter and intramolecular vibrational quantum states in jet-cooled ortho and para H-2-HCl and H-2-DCl complexes, which as a result of weak binding and large zero-point effects provide a novel dynamical window into large-amplitude motion in highly quantum mechanical clusters. The fundamental v(HCl) = 1 <-- 0 stretch bands of H-2-HCl/DCl are observed and elucidate dramatic differences in the vibrationally averaged intermolecular alignment of the H-2 subunit, i.e., T-shaped vs. more nearly isotropic for the lowest ortho (Pi) and para (Sigma) nuclear spin states, respectively. The two internal-rotor states correlating with H-2(j = 1) in the o-H-2-HCl complex are observed via fundamental and combination band excitation built on v(HCl) = 1 <-- 0. The 8.5 cm(-1) internal-rotor splitting between the ground (Pi) and excited (Sigma) H-2 alignments confirms the T-shaped minimum energy configuration for the intermolecular potential, with the HCl proton donating into the H-2 subunit. At even higher energies for o-H-2-HCl, a rich but highly perturbed spectrum of combination band transitions is observed due to the strongly Coriolis coupled manifold ((2j(H2) + 1)(2j(HCl) + 1)= 9) of levels correlating with H-2(j = 1) and HCl(j = 1) subunits. Rotational predissociation broadening accompanied by an abrupt cut off in these combination band spectra is observed and used to estimate a dissociation energy window of D-o = 45 +/- 2 and 47 +/- 2 cm(-1) for the v(HCl) = 0 and 1 intramolecular HCl stretching states, respectively, of the o-H-2-HCl complex. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Nesbitt, DJ (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 23 TC 21 Z9 21 U1 5 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD DEC 15 PY 1998 VL 239 IS 1-3 BP 253 EP 269 DI 10.1016/S0301-0104(98)00359-0 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 153EF UT WOS:000077819600021 ER PT J AU Faeder, J Delaney, N Maslen, PE Parson, R AF Faeder, J Delaney, N Maslen, PE Parson, R TI Modeling structure and dynamics of solvated molecular ions: Photodissociation and recombination in I(2)(-)(CO(2))(n) SO CHEMICAL PHYSICS LA English DT Article ID I2-(CO2)N CLUSTER IONS; THRESHOLD PHOTODETACHMENT SPECTROSCOPY; DISTRIBUTED MULTIPOLE ANALYSIS; KINETIC-ENERGY SPECTROSCOPY; HOMONUCLEAR DIATOMIC IONS; VIBRATIONAL-RELAXATION; GEMINATE RECOMBINATION; CHARGE FLOW; NONADIABATIC TRANSITIONS; QUANTUM DECOHERENCE AB We describe a method for simulating the reaction dynamics of a molecular: ion embedded in a cluster of polarizable solvent molecules. Potential energy surfaces for ground and excited states are calculated from an effective Hamiltonian that takes into account the strong perturbation of the solute electronic structure by the solvent. The parameters of the model Hamiltonian are obtained from a combination of ab initio calculations and spectroscopic data; intermolecular electrostatic and polarization interactions are treated by the distributed multipole analysis of Stone and co-workers, while short range interactions are modeled with empirical pair potentials. Analytical expressions for the derivatives of the effective Hamiltonian allow for efficient computation of forces and nonadiabatic couplings. The intramolecular degrees of freedom of the solvent molecules are held fixed during the simulations using the method of constraints, and electronic transitions are treated using Tully's surface hopping algorithm. The method is applied to the photodissociation and recombination of I(2)(-)(CO(2))(n). Electronic relaxation in this system is found to occur on multiple time scales, ranging from 2 ps to many tens of ps. The relationship of these results with the experimental measurements of Lineberger and co-workers is discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Faeder, J (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 82 TC 28 Z9 28 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD DEC 15 PY 1998 VL 239 IS 1-3 BP 525 EP 547 DI 10.1016/S0301-0104(98)00309-7 PG 23 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 153EF UT WOS:000077819600043 ER PT J AU Holts, DB Julian, A Sosa-Nishizaki, O Bartoo, NW AF Holts, DB Julian, A Sosa-Nishizaki, O Bartoo, NW TI Pelagic shark fisheries along the west coast of the United States and Baja California, Mexico SO FISHERIES RESEARCH LA English DT Article DE fisheries; elasmobranch; resource; management AB Fisheries targeting elasmobranch resources have experienced a dramatic growth during the past two decades. World-wide elasmobranch landings exceed 600 000 metric tons (mt) annually and have clearly made a significant impact on portions of that resource. In the eastern north Pacific catches of common thresher, shortfin mako and blue sharks may exceed 15 000 mt annually. Nearly 90% of all sharks taken within this area are immature. Like most sharks, these pelagics have low rates of increase which make them quite vulnerable to modem day fishing pressure. Clearly the removal of large segments of juveniles from any population has the potential to decrease the adult population to unsustainable levels. The ability of populations to recover from over-exploitation depends not only on initial stock size, natural mortality, and migration rates, but also upon reducing total fishing mortality. Regulations enacted by special interest groups benefiting only one segment of the resource users, combined with the lack of biological information, have slowed progress towards achieving rational management. (C) 1998 Elsevier Science B.V, All rights reserved. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Holts, DB (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NR 22 TC 18 Z9 18 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD DEC 15 PY 1998 VL 39 IS 2 BP 115 EP 125 DI 10.1016/S0165-7836(98)00178-7 PG 11 WC Fisheries SC Fisheries GA 153DT UT WOS:000077818400003 ER PT J AU Rago, PJ Sosebee, KA Brodziak, JKT Murawski, SA Anderson, ED AF Rago, PJ Sosebee, KA Brodziak, JKT Murawski, SA Anderson, ED TI Implications of recent increases in catches on the dynamics of Northwest Atlantic spiny dogfish (Squalus acanthias) SO FISHERIES RESEARCH LA English DT Article DE spiny dogfish; Squalus acanthias; change in ratio methods; mortality; life history; mathematical models ID SHARK TRIAKIS-SEMIFASCIATA; DEMOGRAPHIC-ANALYSIS; CALIFORNIA AB US commercial landings of spiny dogfish have increased five-fold since 1987 to over 22 000 mt in 1993. Over 95% of the landings consist of mature females greater than or equal to 80 cm in length. Minimum discard estimates for 1993 suggest an additional 25 000 mt of dogfish were discarded, of which 14 000 mt were killed. LOWESS-smoothed minimum swept-area biomass estimates reveal a five-fold increase in abundance over the last 30 years to about 650 000 mt in 1993. There is no evidence, however, of a continuing increase in the fishable stock (i.e., greater than or equal to 80 cm in length) since 1990. Mean lengths of dogfish in commercial landings and research survey catches have decreased in the last five years, and fraction of females greater than or equal to 80 cm in the survey has declined markedly. Change-in-sex-ratio estimators were used to derive sex-specific F values. Results suggest a five-fold increase in F on females from 1991 to 1993 to levels in excess of 0.25 per year. Commercial fishery information, research survey data, and life history parameters from the literature were used to develop a size- and sex-structured equilibrium model for dogfish. Using the concept of pups per recruit, preliminary biological reference points for fishing mortality were derived. With a minimum size limit of about 80 cm, fishing mortality rates (F) in excess of 0.2 would lead to the gradual decline of the spiny dogfish stock. While current minimum biomass estimates are high, mature females may already be overexploited. In view of the delayed maturation, low birth rates, and longevity of this species and experiences in shark fisheries worldwide, plans to increase exploitation rates should proceed cautiously to avoid rapid depletion of the adult stock. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Conservat & Utilizat Div, Woods Hole, MA 02543 USA. RP Rago, PJ (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Conservat & Utilizat Div, Woods Hole, MA 02543 USA. NR 38 TC 50 Z9 51 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD DEC 15 PY 1998 VL 39 IS 2 BP 165 EP 181 DI 10.1016/S0165-7836(98)00181-7 PG 17 WC Fisheries SC Fisheries GA 153DT UT WOS:000077818400006 ER PT J AU Stone, RB Bailey, CM McLaughlin, SA Mace, PM Schulze, MB AF Stone, RB Bailey, CM McLaughlin, SA Mace, PM Schulze, MB TI Federal management of US Atlantic shark fisheries SO FISHERIES RESEARCH LA English DT Article DE Atlantic; shark; management; federal AB The Highly Migratory Species Management Division of the National Marine Fisheries Service (NMFS) is responsible for managing 39 species of Atlantic sharks throughout their range in the US exclusive economic zones of the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea. Through the implementation of a Fishery Management Plan, the US harvest of Atlantic shacks is regulated by commercial quotas and trip limits, recreational bag limits, fishery closures, prohibited species, prohibition of finning, and mandatory reporting requirements. While problems still exist in the US shark fishery, NMFS is conducting proactive management designed to help prevent overexploitation and ensure long-term sustainability of Atlantic shark resources. (C) 1998 Elsevier Science. B.V.. All rights reserved. C1 Natl Marine Fisheries Serv, Highly Migratory Species Management Div, Off Sustainable Fisheries, Silver Spring, MD 20910 USA. RP Stone, RB (reprint author), Natl Marine Fisheries Serv, Highly Migratory Species Management Div, Off Sustainable Fisheries, Silver Spring, MD 20910 USA. NR 9 TC 8 Z9 8 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD DEC 15 PY 1998 VL 39 IS 2 BP 215 EP 221 DI 10.1016/S0165-7836(98)00185-4 PG 7 WC Fisheries SC Fisheries GA 153DT UT WOS:000077818400010 ER PT J AU Daves, NK Nammack, MF AF Daves, NK Nammack, MF TI US and International mechanisms for protecting and managing shark resources SO FISHERIES RESEARCH LA English DT Article DE shark trade; Endangered Species Act (ESA); Convention on International Trade in Endangered Species of Wild Fauna and Flora; (CITES); k-strategists; Food and Agriculture Organization; United Nations Agreement on Straddling Fish Stocks and Highly Migratory Fish Stocks AB Sharks have become a popular target for fisheries throughout the world. The presence of profitable markets for shark products, combined with the dwindling status of the more traditional target species such as cod and haddock, have led to the overexploitation of some shark species. Due to their k-selected life history patterns (long-lived, slow-growing animals with a very limited reproductive potential), many shark species are particularly vulnerable to over-exploitation. Some species are likely to be in need of protection. Two possible ways in which sharks could be protected, in addition to traditional harvest management methods are, globally, through the Convention on International Trade in Endangered Species (CITES) or, in the United States, through the Endangered Species Act (ESA). As a result of the United States' recommendation that the international trade in sharks be discussed at the Ninth Conference of the Parties to the CITES in November 1994, a resolution was adopted to review information on the biological status of sharks and the impacts of international trade. More work was done on the resolution at the Tenth Conference of the Parties in June 1997 and is on-going. The ESA provides protection for species that are listed as threatened or endangered. The two agencies administering the ESA must use the best available scientific and commercial data to determine whether a species warrants protection under the ESA. There are currently no international regional regimes for the management of sharks; however, their formation should be investigated by countries and intergovernmental organizations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. RP Daves, NK (reprint author), Natl Marine Fisheries Serv, Off Protected Resources, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 5 TC 6 Z9 6 U1 4 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD DEC 15 PY 1998 VL 39 IS 2 BP 223 EP 228 DI 10.1016/S0165-7836(98)00187-8 PG 6 WC Fisheries SC Fisheries GA 153DT UT WOS:000077818400011 ER PT J AU Angell, JK AF Angell, JK TI Impact of El Chichon and Pinatubo on ozonesonde profiles in north extratropics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID QUASI-BIENNIAL OSCILLATION; SOLAR-CYCLE VARIATION; STRATOSPHERIC OZONE; HETEROGENEOUS CHEMISTRY; VOLCANIC-ERUPTIONS; MOUNT-PINATUBO; MIDLATITUDES; AEROSOL AB The impact of El Chichon and Pinatubo volcanic eruptions on ozonesonde-derived ozone values in 8-16, 16-24 and 24-32 ion layers is estimated for north polar and temperate zones, and the north temperate regions of North America, Europe and Asia, by minimizing the influence of solar cycle and trend, and adjusting for the quasi-biennial variation in ozone by use of the superposed epoch method. Based on this procedure, in north temperate 8-16 and 16-24 km layers the impact of El Chichon is a significant 10 % ozone decrease 3-4 seasons after eruption, the impact of Pinatubo a significant 15% ozone decrease 7 seasons after eruption. In the 24-32 km layer the respective ozone decreases are 2% and 5%, the latter significant. In the north polar zone the ozone decreases following Pinatubo are a significant 20% and 10% in 8-16 and 16-24 km layers, but there are marginally significant ozone increases of 5 % in the 24-32 km layer following both eruptions. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Angell, JK (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 25 TC 4 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1998 VL 25 IS 24 BP 4485 EP 4488 DI 10.1029/1998GL900224 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 154HD UT WOS:000077882600024 ER PT J AU Dagata, JA Inoue, T Itoh, J Matsumoto, K Yokoyama, H AF Dagata, JA Inoue, T Itoh, J Matsumoto, K Yokoyama, H TI Role of space charge in scanned probe oxidation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC-FORCE MICROSCOPE; SILICON; NANOFABRICATION; FABRICATION; ENHANCEMENT; MECHANISMS; KINETICS; GROWTH; FILMS; AFM AB The growth rate and electrical character of nanostructures produced by scanned probe oxidation are investigated by integrating an in situ electrical force characterization technique, scanning Maxwell-stress microscopy, into the fabrication process. Simultaneous topographical, capacitance, and surface potential data are obtained for oxide features patterned on n- and p-type silicon and titanium thin-film substrates. The electric field established by an applied voltage pulse between the probe tip and substrate depends upon reactant and product ion concentrations associated with the water meniscus at the tip-substrate junction and within the growing oxide film. Space-charge effects are consistent with the rapid decline of high initial growth rates, account for observed doping and voltage-pulse dependencies, and provide a basis for understanding local density variations within oxide features. An obvious method for avoiding the buildup of space charge is to employ voltage modulation and other dynamic pulse-shaping techniques during the oxidation pulse. Voltage modulation leads to a significant enhancement of the growth rate and to improvements in the aspect ratio compared with static voltage pulses. (C) 1998 American Institute of Physics. [S0021-8979(98)06324-5]. C1 NIST, Gaithersburg, MD 20899 USA. Electrotech Lab, Ibaraki 305, Japan. RP Dagata, JA (reprint author), NIST, Gaithersburg, MD 20899 USA. EM john.dagata@nist.gov NR 29 TC 157 Z9 157 U1 0 U2 16 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 15 PY 1998 VL 84 IS 12 BP 6891 EP 6900 DI 10.1063/1.368986 PG 10 WC Physics, Applied SC Physics GA 144BJ UT WOS:000077293100062 ER PT J AU Bauer, S Swenson, MS Griffa, A Mariano, AJ Owens, K AF Bauer, S Swenson, MS Griffa, A Mariano, AJ Owens, K TI Eddy mean flow decomposition and eddy-diffusivity estimates in the tropical Pacific Ocean 1. Methodology SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EQUATORIAL PACIFIC; SURFACE CURRENTS; VARIABILITY; TURBULENCE; CIRCULATION; DISPERSION; DRIFTERS; VELOCITY; FIELDS AB The tropical Pacific Ocean surface current system can be characterized by a strong degree of nonstationarity due to the fast response time of equatorial and near-equatorial dynamics. The ocean-atmospheric dynamics create longitudinally coherent zonal flow (zonal length scales l(x) similar to 60 degrees) with strong meridional shear (l(y) similar to 1 degrees in latitude) in the large-scale mean and an energetic mesoscale (O(100 km)) component. Parameterization of the effects of the mesoscale field depends on the separation of the large-scale mean from the observed velocity. In this paper the focus is placed on the key issue: separating the flow into large-scale mean and mesoscale eddy components in order to compute meaningful eddy diffusivity estimates in flow regimes that demonstrate strong currents and strong shear. Large gradients in the large-scale mean have precluded diffusivity estimation by traditional binning techniques. In this first of two publications, a method is developed for using Lagrangian data to estimate the diffusivity addressing the inhomogeneity of the mean flow. The spatially dependent estimate of the mean field is computed with a least squares bicubic smoothing spline interpolation scheme with an optimized roughness parameter which guarantees minimum energy in the fluctuation field at low frequencies. Numerical simulations based on a stochastic model of a turbulent shear flow are used to validate our approach in a conceptually simple but realistic scenario. The technique is applied to near-surface drifter observations obtained from 1979-1946 from two dynamically distinct time-space regions of the tropical Pacific Ocean. The first region, in the South Equatorial Current, is characterized by a linear zonal shear mean flow and an approximately exponential autocovariance structure in the residuals. The velocity residuals have velocity variance of (s) over cap(2) = 130 cm(2) s(-2) for both components, and horizontal diffusivities are <(kappa)over cap>(u) approximate to 7 X 10(7) cm(2) s(-1) and <(kappa)over cap>(v) approximate to 3 X 10(7) cm(2) s(-1). No significant interannual variations of the estimates are detected, but residual trends in the estimators arise from intraseasonal variations in the velocity field during the 3-month season. The second region, in the North Equatorial Countercurrent and the North Equatorial Current, has a mean flow with a strong zonal shear and a weak northward velocity. The autocovariance is approximately exponential for the zonal component, while the meridional component has a negative lobe at about 10 days, probably due to the presence of instability waves. The variance is 380 cm(2) s(-2) for the zonal component and 360 cm(2) s(-2) for the meridional component, while the horizontal diffusivities are <(kappa)over cap>(u) approximate to 15 X 10(7) cm(2) s(-1) and <(kappa)over cap>(v) approximate to 4 X 10(7) cm(2) s(-1). Strong intraseasonal variability requires a maximum time window of 2 months for approximate stationarity to hold for the covariance calculations. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Bauer, S (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM swenson@aoml.erl.gov NR 30 TC 74 Z9 74 U1 2 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 1998 VL 103 IS C13 BP 30855 EP 30871 DI 10.1029/1998JC900009 PG 17 WC Oceanography SC Oceanography GA 155YR UT WOS:000077974900015 ER PT J AU Johnson, GC Musgrave, DL Warren, BA Ffield, A Olson, DB AF Johnson, GC Musgrave, DL Warren, BA Ffield, A Olson, DB TI Flow of bottom and deep water in the Amirante Passage and Mascarene Basin SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SOUTH INDIAN-OCEAN; HYDROGRAPHIC SECTION; SAMOAN PASSAGE; SOMALI BASIN; ARABIAN SEA; CIRCULATION; TRANSPORT; CURRENTS; MASS; HEAT AB In the Indian Ocean the Amirante Passage is the sill through which relatively cold, fresh, oxygen-rich, and nutrient-poor bottom water spreads northward into the Somali Basin from the Mascarene Basin. The passage is also a conduit through which relatively warm, salty, oxygen-poor, and nutrient-rich deep water spreads south. Previous estimates for northward transport of bottom water in the passage have been made from station pairs and sections without benefit of tracer measurements. Previous estimates of southward transport of deep water are scarce. Three hydrographic sections were made across the passage in 1995 and 1996 as part of the World Ocean Circulation Experiment (WOCE). Two WOCE sections were also made perpendicular to the western boundary in the Mascarene Basin, just south of the passage. The geostrophic shear field is used with the salinity, dissolved oxygen, and silica distributions to select a range of zero-velocity surfaces (ZVSs) on potential isotherms from 1.0 degrees to 1.1 degrees C (hence a range of geostrophic transports) for which the flow direction is consistent with the tracer distributions. Objective mapping is used to obtain flux estimates below the deepest common level of station pairs. Estimates in the Mascarene Basin result in a bottom water volume transport from 2.5 to 3.8 x 10(6) m(3) s(-1) northward toward the passage below the ZVSs and a deep-water transport between the ZVSs and 2.5 degrees C from 11.6 to 6.4 x 10(6) m(3) S-1 southward. Estimates within the passage result in transports from 1.0 to 1.7 x 10(6) m(3) s(-1) northward for the bottom water and from 8.6 to 3.8 x 10(6) m(3) s(-1) southward for the deep water. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Univ Alaska Fairbanks, SFOS, Fairbanks, AK 99775 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 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; OI Johnson, Gregory/0000-0002-8023-4020; Olson, Donald/0000-0001-7180-5672 NR 28 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1998 VL 103 IS C13 BP 30973 EP 30984 DI 10.1029/1998JC900027 PG 12 WC Oceanography SC Oceanography GA 155YR UT WOS:000077974900021 ER PT J AU Gu, W Kampe, SL Lu, GQ Wu, HF AF Gu, W Kampe, SL Lu, GQ Wu, HF TI Correlation of fiber pull-out strength and interfacial vibration damping techniques by micromechanical analysis SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SHEAR-STRENGTH; MICROBOND METHOD; RESIN INTERFACE; COMPOSITES; ADHESION AB Adhesion between fiber and matrix in fiber-reinforced polymer composites plays an important role both in controlling mechanical properties and in the overall performance of composites. This suggests that analytical and experimental methods to characterize the interface can be used to predict the mechanical performance of the material. To this end, vibration damping techniques have been used as a non-destructive method to evaluate interfacial effects on composites. According to the theory of energy dissipation, the quality of the interfacial adhesion can be evaluated upon separating the predicted internal energy dissipation associated with perfect adhesion from the measured internal energy dissipation of a composite system; this enables the quantification of interfacial adhesion. A micromechanics-based model for evaluating the adhesion between fiber and matrix from the damping characteristic of a cantilever beam was developed that shows an inverse relationship between the damping contributed by the interface and its adhesion strength. A simple optical system was used to measure the damping factor of unidirectional fiber-reinforced-polymer composites. Cantilever beam specimens containing either a single glass fiber or three types of single metallic wires embedded in an epoxy resin matrix were tested. A correlation was found between the measured interfacial adhesion strength directly from microbond pull-out tests and the micromechanics-based calculations from vibration damping experiments. (C) 1998 Kluwer Academic Publishers. C1 Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. Natl Inst Stand & Technol, Adv Technol Program, Gaithersburg, MD 20899 USA. RP Gu, W (reprint author), Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. RI Lu, Guo-Quan/N-3661-2013 NR 25 TC 9 Z9 12 U1 1 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD DEC 15 PY 1998 VL 33 IS 24 BP 5731 EP 5737 DI 10.1023/A:1004477309721 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 170YG UT WOS:000078834300002 ER PT J AU Kesler, O Matejicek, J Sampath, S Suresh, S Gnaeupel-Herold, T Brand, PC Prask, HJ AF Kesler, O Matejicek, J Sampath, S Suresh, S Gnaeupel-Herold, T Brand, PC Prask, HJ TI Measurement of residual stress in plasma-sprayed metallic, ceramic and composite coatings SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE composites; curvature measurement; diffraction; functionally graded materials; molybdenum; plasma sprayed coatings; residual stress ID FUNCTIONALLY GRADED METALS AB Residual stresses in plasma-sprayed coatings were studied by three experimental techniques: curvature measurements, neutron diffraction and X-ray diffraction. Two distinct material classes were investigated: (I) single-material coatings (molybdenum) and (2) bi-material composites (nickel + alumina and NiCrAlY + yttria-stabilized zirconia), with and without graded layers. This paper deals with the effects of coating thickness and material properties on the evolution of residual stresses as a function of composition and thickness in both homogeneous and graded coatings. Mathematical analysis of the results allowed in some cases the separation of the quenching stress and thermal stress contributions to the final residual stress, as well as the determination of the through-thickness stress profile from measurements of different thickness specimens. In the ceramic-metal composites, it was found that the quenching stress plays a dominant role in the metallic phase, whereas the stress in the ceramic phase is mostly dominated by thermal mismatch. The respective thermal expansion coefficients and mechanical properties are the most important factors determining the stress sign and magnitude. The three residual stress measurement methods employed here were found to be complementary, in that each can provide unique information about the stress state. The most noteworthy outcomes are the determination of the through-thickness stress profile in graded coatings with high spatial resolution (curvature method) and determination of stress in each phase of a composite separately (neutron diffraction). (C) 1998 Elsevier Science S.A. All rights reserved. C1 MIT, Cambridge, MA 02139 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kesler, O (reprint author), MIT, 77 Massachusetts Ave,Room 8-139, Cambridge, MA 02139 USA. RI Matejicek, Jiri/G-2313-2014; OI Matejicek, Jiri/0000-0001-8454-2808; Gnaupel-Herold, Thomas/0000-0002-8287-5091 NR 25 TC 107 Z9 110 U1 4 U2 34 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 1998 VL 257 IS 2 BP 215 EP 224 DI 10.1016/S0921-5093(98)00860-0 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 149ZC UT WOS:000077636200001 ER PT J AU Vassiliev, VV Velichansky, VL Ilchenko, VS Gorodetsky, ML Hollberg, L Yarovitsky, AV AF Vassiliev, VV Velichansky, VL Ilchenko, VS Gorodetsky, ML Hollberg, L Yarovitsky, AV TI Narrow-line-width diode laser with a high-Q microsphere resonator SO OPTICS COMMUNICATIONS LA English DT Article DE optical feedback; line width reduction; frequency stability; high-Q microresonator; whispering-gallery modes ID WHISPERING-GALLERY MODES; VISIBLE INGAALP LASER; SEMICONDUCTOR-LASERS; OPTICAL FEEDBACK; EXTERNAL-CAVITY AB A new modification of external optical feedback (OFB) was used to narrow the line of a diode laser (DL). A 'whispering gallery' (WG) mode of a high-e microsphere was excited by means of frustrated total internal reflection while the feedback for optical locking of the laser was provided by the intracavity Rayleigh backscattering. The similar to 600 MHz beatnote of the two laser diodes optically locked to a pair of orthogonally polarized modes of the same microresonator had the indicated spectral width of 20 kHz, and the stability of 2 x 10(-6) over averaging time of 10 s. The feasibility of miniature sub-kHz-line width laser is discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 PN Lebedev Phys Inst, Moscow 117924, Russia. Moscow MV Lomonosov State Univ, Dept Phys, Moscow 119899, Russia. NIST, Boulder, CO USA. RP Vassiliev, VV (reprint author), Tsentralnaya Str 26-17, Troitsk 142092, Moscow Region, Russia. RI Gorodetsky, Michael/C-5938-2008; Velichansky, Vladimir/M-4861-2015; Vassiliev, Vitali/M-8238-2015 OI Gorodetsky, Michael/0000-0002-5159-2742; NR 22 TC 82 Z9 83 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD DEC 15 PY 1998 VL 158 IS 1-6 BP 305 EP 312 DI 10.1016/S0030-4018(98)00578-1 PG 8 WC Optics SC Optics GA 152AH UT WOS:000077752700041 ER PT J AU Majkrzak, CF Berk, NF AF Majkrzak, CF Berk, NF TI Exact determination of the phase in neutron reflectometry by variation of the surrounding media SO PHYSICAL REVIEW B LA English DT Article AB Recently, it has been shown that the complex amplitude for neutrons specularly reflected from a film can be determined exactly at all accessible wave-vector transfers, including those for which the Born approximation is invalid, through the use of buried reference layers of finite thickness. Given the phase of reflection, it is then possible to solve the one-dimensional inverse-scattering problem directly, without resort to potentially ambiguous fitting procedures, to obtain a unique scattering length density depth profile for a laminar thin-film structure. Here we describe an extension of that phase determination method which utilizes controlled variations of the scattering length density of the incident and/or substrate medium instead of reference layers of finite thickness. This technique is of practical importance for thin-film systems involving either gas-liquid or solid-liquid interfaces in which the scattering length density of the liquid can be varied in a known way, as in an aqueous media consisting of a mixture of H2O and D2O. [S0163-1829(98)04447-6]. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Majkrzak, CF (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 11 TC 46 Z9 47 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 15 PY 1998 VL 58 IS 23 BP 15416 EP 15418 DI 10.1103/PhysRevB.58.15416 PG 3 WC Physics, Condensed Matter SC Physics GA 148PY UT WOS:000077542100036 ER PT J AU Knopp, KJ Mirin, RP Christensen, DH Bertness, KA Roshko, A Synowicki, RA AF Knopp, KJ Mirin, RP Christensen, DH Bertness, KA Roshko, A Synowicki, RA TI Optical constants of (Al0.98Ga0.02)(x)O-y native oxides SO APPLIED PHYSICS LETTERS LA English DT Article ID VERTICAL-CAVITY LASERS; OXIDATION; GAAS; ALXGA1-XAS; ELLIPSOMETRY; ALAS/GAAS; INTERFACE; LAYERS AB We report the optical constants of oxidized crystalline and low-temperature-grown (LTG) Al0.98Ga0.02As films, as determined by variable angle spectroscopic ellipsometry. Data were acquired at three angles of incidence over 240-1700 nm and fitted to a Cauchy dispersion function. For oxidized crystalline material, we observe a variation in the real index of +/-0.5% for layer thickness variations of +/-6%. We show that upon oxidation, LTG material can expand by >25% while crystalline material contracts by <2%. Atomic force microscopy analysis indicates thickness-dependent variations in the oxide microstructure. Additionally, an optical scattering loss of 2.1 X 10(-4)%/pass is calculated based on surface roughness measurements for a thin layer of oxidized crystalline material. (C) 1998 American Institute of Physics. [S0003-6951(98)03550-5]. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. JA Woollam Co Inc, Lincoln, NE 68508 USA. RP Knopp, KJ (reprint author), Natl Inst Stand & Technol, 325 Broadway,MS 815-04, Boulder, CO 80303 USA. OI Mirin, Richard/0000-0002-4472-4655 NR 22 TC 23 Z9 23 U1 0 U2 2 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 14 PY 1998 VL 73 IS 24 BP 3512 EP 3514 DI 10.1063/1.122821 PG 3 WC Physics, Applied SC Physics GA 145ZM UT WOS:000077402800011 ER PT J AU Pellegrino, JG Armstrong, J Lowney, J DiCamillo, B Woicik, JC AF Pellegrino, JG Armstrong, J Lowney, J DiCamillo, B Woicik, JC TI Electron beam induced x-ray emission: An in situ probe for composition determination during molecular beam epitaxy growth SO APPLIED PHYSICS LETTERS LA English DT Article ID MONTE-CARLO CODE; C-LANGUAGE; CASINO; GAAS AB An in situ, x-ray emission measurement technique is developed. This technique is demonstrated to measure composition at the monolayer level for the InGaAs/GaAs heterojunction system. This electron beam induced x-ray emission technique is a powerful method for in situ compositional analysis during molecular beam epitaxy (MBE) growth. Unlike the reflection high-energy electron diffraction (RHEED) method, this electron beam stimulated x-ray emission technique affords a new method for the real-time monitoring of the elemental composition while the sample is rotating during growth. The technique exhibits long term reproducibility, and in addition, compares reasonably well with RHEED. Well-characterized standards are required for quantitative analysis of the composition, and knowledge about the electron sampling trajectories is required for accurate elemental analysis at the monolayer level. (C) 1998 American Institute of Physics. [S0003-6951(98)03350-6]. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Pellegrino, JG (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 14 TC 6 Z9 6 U1 1 U2 2 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 14 PY 1998 VL 73 IS 24 BP 3580 EP 3582 DI 10.1063/1.122830 PG 3 WC Physics, Applied SC Physics GA 145ZM UT WOS:000077402800034 ER PT J AU Hubbard, JB Silin, V Plant, AL AF Hubbard, JB Silin, V Plant, AL TI Self assembly driven by hydrophobic interactions at alkanethiol monolayers: mechanism of formation of hybrid bilayer membranes SO BIOPHYSICAL CHEMISTRY LA English DT Article DE alkanethiols; phospholipids; bilayers; kinetic study; surface plasmon resonance ID POLYMER ADSORPTION; KINETIC-MODEL; GOLD SURFACES; DESORPTION; VESICLES AB The mechanism for the formation of biomimetic model cell membranes consisting of bilayers composed of alkanethiols and phospholipids was probed with a kinetic study using surface plasmon resonance. The kinetics of formation of a monolayer of phospholipid from vesicles in solution onto a hydrophobic alkanethiol monolayer is described by a model that takes into account the lipid concentration, diffusion, and a surface reorganization rate constant. Monomer phospholipid apparently does not play a direct role in determining the kinetics of bilayer formation. Expressions for the limiting cases of this model describe the behavior of two distinct vesicle concentration conditions. At high concentrations of lipid vesicles the: formation of the bilayer appears to be limited by the diffusion of vesicles to the surface; at lower concentrations of vesicles, the rate-limiting step is apparently the surface reorganization of lipid. This kinetic model can also be used to describe the formation of a biomimetic bilayer from an alkanethiol monolayer and cell membranes. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Georgetown Univ, Dept Chem, Washington, DC 20057 USA. RP Hubbard, JB (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 24 TC 72 Z9 73 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD DEC 14 PY 1998 VL 75 IS 3 BP 163 EP 176 DI 10.1016/S0301-4622(98)00199-9 PG 14 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA 152ZW UT WOS:000077809100001 PM 9894336 ER PT J AU Mathew, M Fowler, BO Breuer, E Golomb, G Alferiev, IS Eidelman, N AF Mathew, M Fowler, BO Breuer, E Golomb, G Alferiev, IS Eidelman, N TI Synthesis, characterization, and crystal structure of dicalcium glutarylbis (phosphonate) dihydrate: A covalently pillared layer structure with the potential for epitaxial growth on hydroxyapatite SO INORGANIC CHEMISTRY LA English DT Article ID DIRECTED INORGANIC CRYSTALLIZATION; RAY-POWDER STRUCTURES; ORIENTED NUCLEATION; LANGMUIR MONOLAYERS; METAL PHOSPHONATES; BARITE CRYSTALS; CALCIFICATION; CALCIUM; BISACYLPHOSPHONATES; BISPHOSPHONATES AB A new bis(acylphosphonate), glutarylbis(phosphonate) (GlBP), was synthesized. Sodium and calcium salts of the GlBP, disodium dihydrogen glutarylbis(phosphonate), NaHO3PC(O)(CH2)(3)(O)PO3HNa, and dicalcium glutarylbis(phosphonate) dihydrate, Ca-2[O3PC(O)(CH2)(3)C(O)PO3]. 2H(2)O, were prepared and characterized by chemical analyses, thermogravimetry and Fourier transform infrared spectroscopy (FTIR); The crystal structure of the Ca salt was determined by single-crystal X-ray diffraction. The crystals are orthorhombic with a 10.970(1) Angstrom, b = 23.694(2) Angstrom, 5.580(1) Angstrom, space group Pnma, and Z= 4. This study provides the first example of a structure of a calcium complex involving a nongeminal bis(phosphonate). The structure can be described in terms of a covalently pillared layer-type arrangement of neutral Ca-GlBP-Ca units along the b-axis. Each oxygen atom of the phosphonate group is bonded to a different Ca; ion, and each Ca in turn is linked to three phosphonate groups. The Ca octahedra and the phosphonate tetrahedra form a two-dimensional polar sheet perpendicular to the b-axis. The chelate bonds involving the keto groups appear to be important links in the stabilization of the structure and, in turn,. to the biological activity of bis(acylphosphonates). A near-perfect lattice match, found between the Ca phosphonate layer and the major crystal faces of hydroxyapatite, indicates that epitaxial growth or incorporation of GlBP can occur on the apatitic surface which may be the mode of action in the inhibition of calcification. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NIST, NIDR, Craniofacial & Skeletal Dis Branch, Res Associate Program, Gaithersburg, MD 20899 USA. Hebrew Univ Jerusalem, Sch Pharm, Dept Pharmaceut Chem, IL-91120 Jerusalem, Israel. Hebrew Univ Jerusalem, Sch Pharm, Dept Pharmaceut, IL-91120 Jerusalem, Israel. Univ Penn, Sch Med, Dept Pediat, Philadelphia, PA 19104 USA. RP Mathew, M (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. EM mathai.mathew@nist.gov RI Breuer, Eli/E-8382-2011; OI Golomb, Gershon/0000-0002-7369-9831 NR 46 TC 22 Z9 22 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD DEC 14 PY 1998 VL 37 IS 25 BP 6485 EP 6494 DI 10.1021/ic980374h PG 10 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 148ZR UT WOS:000077581600012 ER PT J AU Parr, AC West, JB Marr, CV Dehmer, JL AF Parr, AC West, JB Marr, CV Dehmer, JL TI Evidence derived from angle-resolved electron spectroscopy for a new spectral series in the photoionization continuum of molecular oxygen SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; AUTOIONIZATION; ANGSTROM; O-2 AB Angle-resolved photoelectron spectroscopy measurements on the O-2 molecule are reported, from which beta-parameters and vibrational branching ratios have been calculated. The measurements were made with good optical resolution in the wavelength region 670-740 Angstrom, where several series converge to the b(4)Sigma(g)(-) State of O-2(+). The application of the measurements to identifying resonant structure is discussed, and evidence presented for a new series converging to the b state. C1 Natl Inst Stand & Technol, Opt Metrol Div, Gaithersburg, MD 20899 USA. SERC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Univ Aberdeen, Sch Phys, Aberdeen AB24 3FX, Scotland. RP Parr, AC (reprint author), Natl Inst Stand & Technol, Opt Metrol Div, Gaithersburg, MD 20899 USA. NR 18 TC 4 Z9 4 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD DEC 14 PY 1998 VL 31 IS 23 BP 5161 EP 5173 DI 10.1088/0953-4075/31/23/013 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 151MJ UT WOS:000077723700013 ER PT J AU Zheludev, A Maslov, S Tsukada, I Zaliznyak, I Regnault, LP Masuda, T Uchinokura, K Erwin, R Shirane, G AF Zheludev, A Maslov, S Tsukada, I Zaliznyak, I Regnault, LP Masuda, T Uchinokura, K Erwin, R Shirane, G TI Experimental evidence for Kaplan-Shekhtman-Entin-Wohlman-Aharony interactions in Ba2CuGe2O7 SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANISOTROPIC SUPEREXCHANGE INTERACTION; SPIN-ORBIT; WEAK FERROMAGNETISM; MAGNETIC-FIELD; ANTIFERROMAGNET; PHASE; FRUSTRATION; SCATTERING AB New neutron diffraction and inelastic neutron scattering experiments on Ba2CuGe2O7 suggest that the previously suggested model for the magnetism of this material (an ideal sinusoidal spin spiral, stabilized by isotropic exchange and Dzyaloshinskii-Moriya interactions) needs to be refined. Both new and previously published experimental results can be quantitatively explained by taking into account the Kaplan-Shekhtman-Entin-Wohlman-Aharony term, a special anisotropy term that was predicted to always accompany Dzyaloshinskii-Moriya interactions in insulators. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. PL Kapitza Phys Problems Inst, Moscow, Russia. CENG, MDN, SPSMS, RFMC, F-38054 Grenoble, France. RP Brookhaven Natl Lab, Upton, NY 11973 USA. RI Zaliznyak, Igor/E-8532-2014; Maslov, Sergei/C-2397-2009 OI Zaliznyak, Igor/0000-0002-9886-3255; Maslov, Sergei/0000-0002-3701-492X NR 19 TC 29 Z9 29 U1 1 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 14 PY 1998 VL 81 IS 24 BP 5410 EP 5413 DI 10.1103/PhysRevLett.81.5410 PG 4 WC Physics, Multidisciplinary SC Physics GA 147RN UT WOS:000077511700039 ER PT J AU Cavicchi, R Sukharev, V Semancik, S AF Cavicchi, R Sukharev, V Semancik, S TI Time-dependent conductance of Pd-dosed SnO2 (110) SO SURFACE SCIENCE LA English DT Letter DE electrical transport measurements; metal-semiconductor interfaces; models of surface chemical reactions; palladium; single crystal surface; surface chemical reaction; surface electrical transport; tin oxides ID SNO2(110); PLASMA AB Time-dependent phenomena related to the reaction of ultrathin films of Pd deposited on SnO2 (110) surfaces of differing oxygen content have been investigated. Conductance measurements and X-ray photoemission spectroscopy (XPS) were used to characterize changes occurring on the surface over a range of metal coverage. Effects on conductance included a rapid change immediately following a deposition and a much slower relaxation over a time scale of 1000 s. On the oxygen-rich surface, prepared by oxygen plasma treatment, only one relaxation process is observed for all coverages of Pd below 5 monolayers-equivalent (MLE). On the nearly stoichiometric surface, prepared by thermal oxidation, the conductance exhibits a conversion from one type of relaxation to another of opposite sign near 1 MLE coverage of Pd. XPS results indicated a slow oxidation of Pd. The results are interpreted using a model that includes oxidation of metal species, formation and charging of surface states, and the effects of overlapping depletion regions that result from the Schottky barriers formed around each metal cluster. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Cavicchi, R (reprint author), NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 15 TC 8 Z9 8 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 14 PY 1998 VL 418 IS 3 BP L81 EP L88 DI 10.1016/S0039-6028(98)00781-X PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 153XB UT WOS:000077857600001 ER PT J AU O'Brien, PT Dietrich, M Leighly, K Alloin, D Clavel, J Crenshaw, DM Horne, K Kriss, GA Krolik, JH Malkan, MA Netzer, H Peterson, BM Reichert, GA Rodriguez-Pascual, PM Wamsteker, W Anderson, KSJ Bochkarev, NG Cheng, FZ Filippenko, AV Gaskell, CM George, IM Goad, MR Ho, LC Kaspi, S Kollatschny, W Korista, KT MacAlpine, G Marlow, D Martin, PG Morris, SL Pogge, RW Qian, BC Recondo-Gonzalez, MC Espinosa, JMR Santos-Lleo, M Shapovalova, AI Shull, JM Stirpe, GM Sun, WH Turner, TJ Vio, R Wagner, S Wanders, I Wills, KA Wu, H Xue, SJ Zou, ZL AF O'Brien, PT Dietrich, M Leighly, K Alloin, D Clavel, J Crenshaw, DM Horne, K Kriss, GA Krolik, JH Malkan, MA Netzer, H Peterson, BM Reichert, GA Rodriguez-Pascual, PM Wamsteker, W Anderson, KSJ Bochkarev, NG Cheng, FZ Filippenko, AV Gaskell, CM George, IM Goad, MR Ho, LC Kaspi, S Kollatschny, W Korista, KT MacAlpine, G Marlow, D Martin, PG Morris, SL Pogge, RW Qian, BC Recondo-Gonzalez, MC Espinosa, JMR Santos-Lleo, M Shapovalova, AI Shull, JM Stirpe, GM Sun, WH Turner, TJ Vio, R Wagner, S Wanders, I Wills, KA Wu, H Xue, SJ Zou, ZL TI Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. XIII. Ultraviolet observations of the broad-line radio galaxy 3C 390.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (3C 390.3); ultraviolet : galaxies ID SHORT-TIMESCALE VARIABILITY; MULTIWAVELENGTH OBSERVATIONS; X-RAY; EMISSION-LINES; OPTICAL WAVELENGTHS; ACCRETION DISKS; UV CONTINUUM; NGC-5548; NGC-4151; 3C-390.3 AB As part of an extensive multiwavelength monitoring campaign, the Inter national Ultraviolet Explorer satellite was used to observe the broad-line radio galaxy 3C 390.3 during the period 1994 December 31-1996 March 5. Spectra were obtained every 6-10 days. The UV continuum varied by a factor of 7 through the campaign, while the broad emission lines varied by factors of 2-5. Unlike previously monitored Seyfert 1 galaxies, in which the X-ray continuum generally varies with a larger amplitude than the UV, in 3C 390.3 the UV continuum light curve is similar in both amplitude and shape to the X-ray light curve observed by ROSAT. The UV broad emission-line variability lags that of the UV continuum by 35-70 days for Ly alpha and C rv, values larger than those found for Seyfert 1 galaxies of comparable UV luminosity. These lags are also larger than those found for the Balmer lines in 3C 390.3 over the same period. The red and blue wings of C rv and Ly alpha vary in phase, suggesting that radial motion does not dominate the kinematics of the UV line-emitting gas. Comparison with archival data provides evidence for velocity-dependent changes in the Ly alpha and C rv line profiles, indicating evolution in the detailed properties and/or distribution of the broad-line emitting gas. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Landessternwarte, D-69117 Heidelberg, Germany. Columbia Univ, Astrophys Lab, New York, NY 10027 USA. Ctr Etud Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. European Space Agcy, ISO Project, Madrid 28080, Spain. NASA, Goddard Space Flight Ctr, Comp Sci Corp, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ St Andrews, Sch Phys & Astron, St Andrews KYI16 9SS, Fife, Scotland. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90024 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Wise Observ, IL-69978 Tel Aviv, Israel. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ESA IUE Observ, Madrid 28080, Spain. New Mexico State Univ, Dept Astron, Dept 4500, Las Cruces, NM 88003 USA. Moscow MV Lomonosov State Univ, Sternberg Astron Inst, Moscow 119899, Russia. Univ Sci & Technol, Ctr Astrophys, Hefei, Anhui, Peoples R China. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Sternwarte Gottingen, D-37083 Gottingen, Germany. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Univ Manchester, Nuffield Radio Astron Lab, Jodrell Bank, Macclesfield SK11 9DL, Cheshire, England. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Chinese Acad Sci, Shanghai Astron Observ, Shanghai 20030, Peoples R China. LAEFF, E-28080 Madrid, Spain. Russian Acad Sci, Special Astrophys Observ, Nizhni Arkhyz 357147, Karachaj Cherkn, Russia. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Osservatorio Astron Bologna, I-40126 Bologna, Italy. Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. Chinese Acad Sci, Beijing Astron Observ, Beijing 100080, Peoples R China. RP O'Brien, PT (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. RI Morris, Simon/G-7981-2011; Recondo, Carmen/B-1215-2012; Stirpe, Giovanna/O-9393-2015; OI Morris, Simon/0000-0003-4866-110X; Recondo, Carmen/0000-0001-9813-6798; Stirpe, Giovanna/0000-0002-3702-8731; Gaskell, C/0000-0003-4888-2009 NR 57 TC 67 Z9 68 U1 1 U2 4 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 1998 VL 509 IS 1 BP 163 EP 176 DI 10.1086/306464 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DE UT WOS:000079250400016 ER PT J AU Parker, JW Stern, SA Gladstone, G Shull, JM AF Parker, JW Stern, SA Gladstone, G Shull, JM TI The spectroscopic detectability of argon in the lunar atmosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; line : formation; methods : data analysis; Moon; radiative transfer; ultraviolet : solar system ID OSCILLATOR-STRENGTHS; EXTREME-ULTRAVIOLET; EXCITATION; SODIUM; LINES; AR AB Direct measurements of the abundance of argon in the lunar atmosphere were made in 1973 by instruments placed on the Moon during the Apollo 17 mission, but the total daytime abundance is unknown because of instrument saturation effects; thus, until we are able to return to the Moon for improved direct measurements, we must use remote sensing to establish the daytime abundance. In this Letter, we present a complete analysis of the potential for measuring argon in the lunar atmosphere via emission-line or absorption-line observations. We come to the surprising conclusion that the lower limit established by the in situ lunar argon measurements implies that any absorption-line measurement of argon in the lower, dayside lunar atmosphere requires analysis in the optically thick regime. In light of this result, we present the results of our extreme-ultraviolet spectrograph sounding rocket observations of the lunar occultation of Spice, which provide a new upper limit on the abundance of argon in the daytime lunar atmosphere. We also reanalyze a recently reported weak detection by the ORFEUS satellite of lunar atmospheric Ar I lambda 1048 in emission and show that those data are inconsistent with the emission being due to argon over a wide range of temperatures (up to at least 2000 K). This result is primarily due to our use of a more complete curve-of-growth analysis and improved values for the argon fluorescent emission rates from radiation and solar wind interactions. We find that the detection reported by ORFEUS would imply an argon surface density significantly greater than the total surface density of the lunar atmosphere for argon accommodated to typical daytime surface temperatures (similar to 400 K) and also is inconsistent with a high-density transient event. Therefore, we conclude that the reported argon detection is untenable. C1 SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. SW Res Inst, Dept Space Sci, San Antonio, TX 78238 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Ctr Astrophys & Space Phys, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Parker, JW (reprint author), SW Res Inst, Dept Space Studies, Suite 426,1050 Walnut St, Boulder, CO 80302 USA. NR 24 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1998 VL 509 IS 1 BP L61 EP L64 DI 10.1086/311758 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DF UT WOS:000079250500016 ER PT J AU Gaffen, DJ Ross, RJ AF Gaffen, DJ Ross, RJ TI Increased summertime heat stress in the US SO NATURE LA English DT Letter ID MINIMUM TEMPERATURE; UNITED-STATES; RESPONSES; MAXIMUM; TRENDS C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Gaffen, DJ (reprint author), NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 12 TC 96 Z9 101 U1 1 U2 9 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD DEC 10 PY 1998 VL 396 IS 6711 BP 529 EP 530 DI 10.1038/25030 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 147AY UT WOS:000077466800039 ER PT J AU Peng, TH Wanninkhof, R Bullister, JL Feely, RA Takahashi, T AF Peng, TH Wanninkhof, R Bullister, JL Feely, RA Takahashi, T TI Quantification of decadal anthropogenic CO2 uptake in the ocean based on dissolved inorganic carbon measurements SO NATURE LA English DT Article ID DIOXIDE; AIR AB About half of the 'anthropogenic' CO2 emitted to the atmosphere is taken up by the oceans and terrestrial biosphere(1), and the amount sequestered by the ocean is generally estimated using numerical ocean carbon-cycle models(2). But these models often differ markedly(3), resulting in different estimated spatial and temporal patterns and magnitudes of uptake. Because of its importance climatically, the CO2 flux needs to be verified using field measurements. Accurate estimates of CO2 uptake have been difficult to obtain, however, as the annual increase of dissolved inorganic carbon (DIC) concentration in surface water due to anthropogenic input is similar to 0.05% of the total DIC, an order of magnitude lower than past measurement precision. Early measurement-based estimates(4,5) of total anthropogenic CO2 inventory in the ocean have recently been improved on(6,7), and new approaches have been proposed for determining changes in ocean DIC concentration over one to two decades(8,9). Here we use recent improvements in DIC measurement techniques to determine changes in DIC concentrations between 1978 and 1995 in the Indian Ocean. Our method subtracts decadal-scale natural variability, enabling the ocean anthropogenic CO2 increase in this region over the 17-year period to be determined. The calculated uncertainties and known measurement capabilities allow us to define the minimum sampling strategies that will be required to quantify the regional and global anthropogenic CO2 oceanic uptake over future decades. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Peng, TH (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NR 27 TC 54 Z9 58 U1 1 U2 18 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD DEC 10 PY 1998 VL 396 IS 6711 BP 560 EP 563 DI 10.1038/25103 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 147AY UT WOS:000077466800053 ER PT J AU Laursen, SL Grace, JE DeKock, RL Spronk, SA AF Laursen, SL Grace, JE DeKock, RL Spronk, SA TI Reaction of NH (X) with oxygen in a solid xenon matrix: Formation and infrared spectrum of imine peroxide, HNOO SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID INDUCED PHOTO-DISSOCIATION; VIBRATIONAL FREQUENCIES; WAVE-FUNCTIONS; ELECTRONIC-STRUCTURE; ELEMENTARY REACTIONS; DIATOMIC-MOLECULES; CARBONYL OXIDES; ENERGY-TRANSFER; NITROUS-ACID; NITRIC-ACID AB The reaction between molecular oxygen and the imidogen radical NH in their ground electronic states has been investigated in solid cryogenic rare gas matrices. A photolabile product forms upon annealing a xenon matrix containing oxygen and trapped NH radicals produced by in situ UV photodissociation of hydrazoic acid. The product is identified as imine peroxide, HNOO, by its infrared spectrum and its photoisomerization to nitrous acid, with support from the calculated vibrational spectrum and O-18 isotope shifts. The reaction is essentially activationless. Some aspects of the potential energy surface for this species are delineated by the conditions under which HNOO is formed and destroyed. This is the first detection of this compound, a 1,3-dipole isoelectronic with ozone and peroxymethylene. C1 Kalamazoo Coll, Dept Chem, Kalamazoo, MI 49006 USA. Calvin Coll, Dept Biochem & Chem, Grand Rapids, MI 49546 USA. RP Laursen, SL (reprint author), NOAA, 325 Broadway,R-E-AL2, Boulder, CO 80303 USA. OI LAURSEN, SANDRA/0000-0002-4327-9887 NR 94 TC 21 Z9 22 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 9 PY 1998 VL 120 IS 48 BP 12583 EP 12594 DI 10.1021/ja970749i PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 146ZM UT WOS:000077463800023 ER PT J AU Murtz, P Zink, LR Evenson, KM Brown, JM AF Murtz, P Zink, LR Evenson, KM Brown, JM TI Measurement of high-frequency rotational transitions of H2O+ in its ground state by far-infrared laser magnetic resonance (LMR) spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COMET-KOHOUTEK; WATER CATION; SPECTRUM; IDENTIFICATION; EQUILIBRIUM; CONSTANTS AB Thirteen new rotational transitions of H2O+ in the (0,0,0) level of the (X) over tilde B-2(1) State have been measured in the wavenumber region between 80 and 200 cm(-1) (50 and 120 mu m) by far-infrared laser magnetic resonance (LMR) spectroscopy. LMR data measured previously between 25 and 90 cm(-1) (110 and 400 mu m), as well as optical and infrared combination differences, have been combined with the new LMR data in a weighted least-squares analysis using an A-reduced expression of the rotational-fine structure Hamiltonian. Thirty-two molecular constants were simultaneously determined, some sextic centrifugal distortion parameters and some quartic and sextic spin-rotation parameters for the first time. From this improved set of molecular parameters, very accurate calculations of relational term values and zero-held predictions of the 1(11)-0(00) transition, including hyperfine structure, have been performed. Moreover, the electronic g-tensors and the hyperfine coupling constants are consistent with ab initio calculations which had been carried out for these constants. (C) 1998 American Institute of Physics. [S0021-9606(98)00746-6]. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. RP Murtz, P (reprint author), Univ Bonn, Radiol Klin, Sigmund Freud Str 25, D-53105 Bonn, Germany. EM muertz@imsdd.meb.uni-bonn.de NR 23 TC 34 Z9 34 U1 0 U2 5 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 8 PY 1998 VL 109 IS 22 BP 9744 EP 9752 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 143UT UT WOS:000077276000016 ER PT J AU Ruzgas, T Wong, L Gaigalas, AK Vilker, VL AF Ruzgas, T Wong, L Gaigalas, AK Vilker, VL TI Electron transfer between surface-confined cytochrome c and an N-acetylcysteine-modified gold electrode SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; RESONANCE RAMAN-SPECTROSCOPY; SILVER ELECTRODE; REFLECTANCE SPECTROSCOPY; REDOX REACTIONS; DOUBLE-LAYER; ELECTROREFLECTANCE; ELECTROCHEMISTRY; METALLOPROTEINS; VOLTAMMOGRAM AB Cytochrome c (cyt c) was adsorbed on N-acetylcysteine (NAC)-modified gold electrodes via electrostatic interaction. The cyt c layer exhibited reversible and stable electrochemical redox transformation in 0.01 M phosphate butter, pH 7.4, where the heterogeneous electron transfer (ET) constant k'(het) was measured by three techniques: cyclic voltammetry at high sweep rates (CV), electrochemical impedance (EI), and electroreflectance (ER) spectroscopy. In addition, k'(het) was also determined from combining sets of simultaneous electrochemical impedance (EI) and electroreflectance (ER) measurements in a new impedance model in which a constant-phase element was used. The negligible shift(-0.023 mV) in the formal potential from the solution value, and the dose agreement of the measured distribution around the CV peaks (full-width voltage at half-peak-height, E-fwhh = 97 mV) with the theoretical value of 90.6 mV, suggested that the immobilized cyt c is retained at the electrode in the native state. Apparent k'(het) values, as determined by each method separately, were as follows: (k'(CV) = 920 +/- 280 s(-1) by CV, k'(EI) = 660 +/- 200 s(-1) by EI, and k'(ER) = 2100 +/- 300 s(-1) by ER as interpreted using previously published methods.(14,15,30) In the combined EI/ER measurements, k'ER was found to increase linearly with the frequency of the sc modulating current and spanned a range from about 400 to 800 s(-1), which is close to the interprotein electron-transfer rate constant (800 s(-1)) measured between cyt c and one of its natural redox partners, cytochrome c peroxidase.(31) It is concluded that further attempts to reconcile these discrepancies in k'(het) determinations will require more detailed descriptions of the interfacial elements in the impedance models. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Gaigalas, AK (reprint author), NIST, Div Biotechnol, 222-A353, Gaithersburg, MD 20899 USA. EM adolfas.gaigalas@nist.gov RI Ruzgas, Tautgirdas/C-4646-2008 NR 36 TC 36 Z9 37 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 8 PY 1998 VL 14 IS 25 BP 7298 EP 7305 DI 10.1021/la9808519 PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 147KC UT WOS:000077511100031 ER PT J AU Cahn, JW Mallet-Paret, J Van Vleck, ES AF Cahn, JW Mallet-Paret, J Van Vleck, ES TI Traveling wave solutions for systems of ODEs on a two-dimensional spatial lattice SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE traveling waves; propagation failure; anisotropy; Allen-Cahn equation ID NONLINEAR DIFFUSION-EQUATIONS; DIFFERENTIAL-DELAY EQUATION; CELLULAR NEURAL NETWORKS; DISCRETE NAGUMO EQUATION; DYNAMIC MECHANISM; METASTABLE PHASES; PATTERN-FORMATION; FRONT SOLUTIONS; BEHAVIOR; ORBITS AB We consider infinite systems of ODEs on the two-dimensional integer lattice, given by a bistable scalar ODE at each point, with a nearest neighbor coupling between lattice points. For a class of ideal nonlinearities, we obtain traveling wave solutions in each direction e(i theta), and we explore the relation between the wave speed c, the angle theta, and the detuning parameter a of the nonlinearity. Of particular interest is the phenomenon of "propagation failure," and we study how the critical value a = a*(theta) depends on theta, where a*(theta) is defined as the value of the parameter a at which propagation failure (that is, wave speed c = 0) occurs. We show that a* : R --> R is continuous at each point theta where tan theta is irrational, and is discontinuous where tan theta is rational or infinite. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20760 USA. Brown Univ, Div Appl Math, Providence, RI 02912 USA. Colorado Sch Mines, Dept Math & Comp Sci, Golden, CO 80401 USA. RP Cahn, JW (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20760 USA. EM cahn@enh.nist.gov; jmp@cfm.brown.edu; erikvv@poincare.mines.edu RI Van Vleck, Erik/C-3273-2009 NR 42 TC 47 Z9 49 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PD DEC 8 PY 1998 VL 59 IS 2 BP 455 EP 493 PG 39 WC Mathematics, Applied SC Mathematics GA 145KK UT WOS:000077370000005 ER PT J AU Holland, M AF Holland, M TI Unraveling quantum dissipation in the frequency domain SO PHYSICAL REVIEW LETTERS LA English DT Article ID WAVE-FUNCTION APPROACH; STATE DIFFUSION; OPTICS AB We present a quantum Monte Carlo method for solving the evolution of an open quantum system. In our approach, the density operator evolution is unraveled in the frequency domain. Significant advantages of this approach arise when the frequency of each dissipative event conveys information about the state of the system. [S0031-9007(98)07862-4]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Holland, M (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 12 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 7 PY 1998 VL 81 IS 23 BP 5117 EP 5120 DI 10.1103/PhysRevLett.81.5117 PG 4 WC Physics, Multidisciplinary SC Physics GA 145GH UT WOS:000077362300020 ER PT J AU Moffat, TP AF Moffat, TP TI Oxidative chloride adsorption and lead upd on Cu(100): Investigations into surfactant-assisted epitaxial growth SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY-ELECTRON DIFFRACTION; IN-SITU STM; UNDERPOTENTIAL DEPOSITION; ALLOY FORMATION; ATOMIC MECHANISMS; PB; CU(111); SPECTROSCOPY; CU; SUPERLATTICES AB The influence of chloride adsorption and lead upd on the step dynamics of Cu(100) has been examined in acid perchlorate solution. A c(2 x 2) Cl adlayer is formed upon immersion of a Cu(100) electrode leading to step faceting in the [100] direction. At more negative potentials an order-disorder transformation occurs leading to significant rearrangement of the steps. Alternatively, in an electrolyte containing Pb2+ th, halide adlayer may be completely displaced by lead upd. Images of orthogonal surface steps in combination with an assessment of the coulometry suggest that the lead adlayer forms either a highly defective c(2 x 2), c(5 root 2 x root 2)R45 degrees or a disordered structure corresponding to a coverage ranging from 0.5 to 0.6. The transformation from the halide to the lead adlayer results in the formation of vacancies and adatoms which condense to form holes and islands, respectively. These features may be rationalized by the formation of an alloy phase at low coverage, which subsequently dealloys as the coverage approaches 0.5. The extent of the morphological changes associated with the alloying/dealloying processes is strongly path dependent. Voltammetry reveals that the stripping of the lead upd layer is associated with two oxidation waves. As the potential is increased beyond the peak of the first wave islands disappear which may be due to alloy formation occurring coincident with partial desorption of the lead. The second wave is associated with the nucleation [100]-oriented rows of the c(2 x 2) Cl adlayer which propagate across the terraces displacing the lead phase. he use of metal upd and anions as surfactants in the electrochemical deposition of copper is likely to prove even more interesting than in vacuum deposition since the surfactant coverage and its effect on mesoscopic structure can be continuously manipulated by potential control. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Moffat, TP (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 38 TC 27 Z9 28 U1 2 U2 7 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 3 PY 1998 VL 102 IS 49 BP 10020 EP 10026 DI 10.1021/jp9828888 PG 7 WC Chemistry, Physical SC Chemistry GA 146ZV UT WOS:000077464500037 ER PT J AU Beck, CM AF Beck, CM TI A traceability protocol to the SI by gravimetric analysis SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Article DE certification; gravimetric analysis; measurement; measurement uncertainty; reference material; traceability AB An example is presented of a traceability protocol for the measurement of a single-element strontium reference material solution, executed by a "primary" method of measurement for certification. The method of measurement is briefly described together with the measurement equation and the associated calculations for the estimation of uncertainties, This is followed by a discussion and estimate of each component of uncertainty associated with the measurement, together with a final estimate of uncertainty. The final estimate of uncertainty compares well with observed uncertainties for two previous laboratory measurements of the reference material. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Beck, CM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-1775 J9 ACCREDIT QUAL ASSUR JI Accredit. Qual. Assur. PD DEC PY 1998 VL 3 IS 12 BP 482 EP 484 DI 10.1007/s007690050292 PG 3 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 154TV UT WOS:000077905900002 ER PT J AU Hobbie, EK Migler, KB Han, CC Amis, EJ AF Hobbie, EK Migler, KB Han, CC Amis, EJ TI Light scattering and optical microscopy as in-line probes of polymer blend extrusion SO ADVANCES IN POLYMER TECHNOLOGY LA English DT Article ID PHASE DISTRIBUTION MORPHOLOGY; RHEOLOGICAL MEASUREMENTS; INCOMPATIBLE POLYMERS; UNIFORM SHEAR; MIXTURES; MELTS; FIBRILLATION; BEHAVIOR; FLOW AB A light-scattering photometer with optical microscope for in situ morphological studies of extruded polymer blends is described. The optics for light scattering and microscopy can be switched back and forth via simple translation of a rail-mounted optical platform without realignment, allowing efficient measurements in both real and reciprocal space during polymer processing. Blends of polystyrene and polyethylene are used to demonstrate the performance and versatility of the instrument. (C) 1998 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RP Hobbie, EK (reprint author), Natl Inst Stand & Technol, Div Polymer, Bldg 224,Room B210, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 19 TC 12 Z9 12 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0730-6679 J9 ADV POLYM TECH JI Adv. Polym. Technol. PD WIN PY 1998 VL 17 IS 4 BP 307 EP 316 DI 10.1002/(SICI)1098-2329(199824)17:4<307::AID-ADV2>3.0.CO;2-V PG 10 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 133FW UT WOS:000076677000002 ER PT J AU Howell, S Pszenny, AAP Quinn, P Huebert, B AF Howell, S Pszenny, AAP Quinn, P Huebert, B TI A field intercomparison of three cascade impactors SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID LOW-PRESSURE IMPACTOR; ATMOSPHERIC AEROSOL-PARTICLES; SIZE DISTRIBUTIONS; MARINE ATMOSPHERE; DRY DEPOSITION; EFFICIENCY; SULFATE; ACID; CONDENSATION; ALGORITHM AB Cascade impactors separate aerosol particles inertially and collect them for later analysis. While laboratory calibrations typically indicate performance close to design specifications, during field operation impactors are subject to a number of sampling artifacts, including particle bounce, inlet and internal losses, and particle size changes as pressure drops within the impactor. To test the vulnerability of some commonly used impactors to these problems under field conditions, we participated in a shipboard intercomparison off the coast of Washington state between a micro-orifice uniform deposit impactor (MOUDI), a Berner low-pressure impactor, and a Sierra high-volume slotted impactor. Since there were some inconsistencies in the results, a second intercomparison was performed at Bellows Beach, Hawaii, between two MOUDIs and the Berner impactor. Impactor samples were analyzed for soluble inorganic ions including Na+, K+, Cl-, and NO3-, primarily from large (>1 mu m) sea salt particles and NH4+, nonsea salt sulfate (NSS), and methanesulfonate (MS-), found primarily in smaller aerosols. The Sierra collected sea salt particles far more efficiently than the other impactors, which had severe inlet losses for 7 mu m and larger particles. The MOUDI and Berner showed insignificant differences in the mass median diameter of accumulation mode particles (similar to 0.34 mu m), whereas the Sierra indicated almost twice the diameter (0.58 mu m) of the others. (C) 1998 American Association for Aerosol Research. C1 Univ Hawaii Manoa, Dept Oceanog, Honolulu, HI 96822 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Rhode Isl, Grad Sch Oceanog, Kingston, RI 02881 USA. RP Huebert, B (reprint author), Univ Hawaii Manoa, Dept Oceanog, Honolulu, HI 96822 USA. RI Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 38 TC 36 Z9 36 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD DEC PY 1998 VL 29 IS 6 BP 475 EP 492 DI 10.1080/02786829808965585 PG 18 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 139PJ UT WOS:000077037700002 ER PT J AU House, BW Larson, DM Terry, JM AF House, BW Larson, DM Terry, JM TI Revenue risk and fishery choice with linear-exponential utility: An application to Bering Sea Aleutian Islands trawl fisheries. SO AMERICAN JOURNAL OF AGRICULTURAL ECONOMICS LA English DT Meeting Abstract C1 Claremont Mckenna Coll, Claremont, CA 91711 USA. Univ Calif Davis, Davis, CA 95616 USA. Alaska Fishery Sci Ctr, Anchorage, AK USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER AGRICULTURAL ECONOMICS ASSOC PI AMES PA 415 SOUTH DUFF AVE, STE C, AMES, IA 50010-6600 USA SN 0002-9092 J9 AM J AGR ECON JI Am. J. Agr. Econ. PD DEC PY 1998 VL 80 IS 5 BP 1198 EP 1198 PG 1 WC Agricultural Economics & Policy; Economics SC Agriculture; Business & Economics GA 163CZ UT WOS:000078386300380 ER PT J AU Geiselbrecht, AD Hedlund, BP Tichi, MA Staley, JT AF Geiselbrecht, AD Hedlund, BP Tichi, MA Staley, JT TI Isolation of marine polycyclic aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and comparison of their PAH degradation ability with that of Puget Sound Cycloclasticus strains SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID NAPHTHALENE DIOXYGENASE; BACTERIAL ENDOSYMBIONTS; PHYLOGENETIC DIVERSITY; BIPHENYL DIOXYGENASE; NUCLEOTIDE-SEQUENCE; ESCHERICHIA-COLI; GEN-NOV; PHENANTHRENE; SEDIMENT; CLONING AB Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 10(2) to 10(6) cells per mi of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAW)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAW substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAW-degrading bacteria in both Puget Sound and the Gulf of Mexico. C1 Univ Washington, Dept Microbiol, Seattle, WA 98195 USA. RP Geiselbrecht, AD (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM Allison.Geiselbrecht@noaa.gov FU PHS HHS [6M-0837-05] NR 63 TC 103 Z9 112 U1 3 U2 27 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 1998 VL 64 IS 12 BP 4703 EP 4710 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 145XB UT WOS:000077396700012 PM 9835552 ER PT J AU Storebakken, T Kvien, IS Shearer, KD Grisdale-Helland, B Helland, SJ Berge, GM AF Storebakken, T Kvien, IS Shearer, KD Grisdale-Helland, B Helland, SJ Berge, GM TI The apparent digestibility of diets containing fish meal, soybean meal or bacterial meal fed to Atlantic salmon (Salmo salar): evaluation of different faecal collection methods SO AQUACULTURE LA English DT Article; Proceedings Paper CT VII International Symposium on Nutrition and Feeding of Fish CY AUG 11-15, 1996 CL TEXAS A&M UNIV, COLLEGE STN, TX HO TEXAS A&M UNIV DE digestibility-method; fish meal; soybean meal; bacterial protein; single-cell protein; Atlantic salmon (Salmo salar) ID RAINBOW-TROUT; GASTROINTESTINAL-TRACT; FEED-INTAKE; CARBOHYDRATE; FEEDSTUFFS; PROTEIN; FECES; WATER AB Digestibility measurements obtained from four faecal collection methods were compared in two experiments with Atlantic salmon, reared in freshwater. The fish were fed three diets with different protein sources: a diet with 55% fish meal (FM); a diet with 35% FM and 31% soybean meal; and a diet with 34% FM and 20% bacterial meal. In Expt. 1, faecal dry matter content and apparent digestibility coefficients (ADC) of macronutrients were compared using three different methods of faeces collection: stripping, mechanical sieving of faeces from the outlet water of the tanks and immediate freezing (sieving), and by dissection. In Expt. 2, stripping and sieving were compared to a procedure where the ice and faeces mixture from sieving was freeze dried prior to analysis (sieving with FD). Faecal dry matter content, and the ADCs of organic matter and fat differed significantly between all three diets (soybean meal diet < bacterial meal diet < fish meal diet). ADC of nitrogen (N) was significantly higher in the fish meal diet than in the other two diets in Expt. 1, whereas in Expt. 2, ADC of N was equal in the fish meal and soybean meal diets. The soybean meal and bacterial meal diets were ranked to give lower ADC of energy than the fish meal diet. For faecal dry matter content, all three collection methods used in Expt. 1 were ranked differently (stripping < sieving < dissection). For ADC of organic matter and N, sieving produced significantly higher means than the other two methods. In Expt. 2, the same ranking of the three different collection methods used (stripping < sieving with FD < sieving) was seen for ADC of organic matter, N and energy. Faecal collection method had no effect on the estimates of ADC of fat. Diet differences explained 45% of the variation in ADC of organic matter and 14% for ADC of N in the two experiments. Faecal collection method explained 42% of the variation in ADC of organic matter and 63% of the variation in ADC of N. Small, but significant, interactions between diet and collection method were seen for these two digestibility estimates. The results obtained using the different faecal collection methods were highly correlated within experiment for all estimates with the exception of the ADC of N in Expt. 2. No significant differences were seen between the two experiments with respect to ADC of organic matter and N, and the estimates from the two experiments were highly correlated. (C) 1998 Elsevier Science B.V. All rights reserved. C1 AKVAFORSK, Inst Aquaculture Res, N-6600 Sunndalsora, Norway. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Storebakken, T (reprint author), AKVAFORSK, Inst Aquaculture Res, N-6600 Sunndalsora, Norway. EM trond.storebakken@akvaforsk.nlh.no RI storebakken, trond/E-8050-2011 OI storebakken, trond/0000-0002-4525-2098 NR 31 TC 93 Z9 102 U1 1 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD DEC 1 PY 1998 VL 169 IS 3-4 BP 195 EP 210 DI 10.1016/S0044-8486(98)00379-2 PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 148RM UT WOS:000077546100004 ER PT J AU Meador, JP Sibley, TH Swartzman, GL Taub, FB AF Meador, JP Sibley, TH Swartzman, GL Taub, FB TI Copper tolerance by the freshwater algal species Oocystis pusilla and its ability to alter free-ion copper SO AQUATIC TOXICOLOGY LA English DT Article DE copper; toxicity; hormesis; oocystis; algal metabolism ID DISSOLVED ORGANIC-CARBON; TOXICITY; ACCUMULATION; ECOSYSTEM; LIGANDS; WATERS; STRESS; LAKE; PH AB Previous studies with copper-stressed microcosms found that recovery was dependent on a copper-resistant algal species [Taub, 1989. Aquatic Ecotoxicology: Fundamental Concepts and Methodologies, pp. 47-92. Meader, J.P., Taub, F.B., Sibley, T.H., 1993. Ecol. Appl. 3, 139-155]. One algal species, Oocystis pusilla, was able to bloom in microcosms that had been devoid of organismal activity for several weeks due to the addition of copper at a high concentration (31.5 mu M). In the present study, experiments were performed to characterize the range in tolerance of O. pusilla to copper, determine its growth under low and high pH regimes as a function of copper exposure, and to examine its ability to alter pH and ionic-copper activity (ICu) over time. Total-copper (TCu) concentrations up to 78.7 mu M and ICu values as high as 0.9 mu M had no negative effects on O. pusilla, indicating that it is highly copper-tolerant. The best growth for O. pusilla generally occurred in the range of 8-20 mu M (total or dissolved copper), indicating a hermetic effect (enhanced response at intermediate concentrations). Even though its abundance was severely depressed in a TCu solution of 157.5 mu M, this species was able to increase fourfold in 14 days. O. pusilla increased its numbers at a faster rate in high pH (approximate to 9) solutions; however, it was able to propagate when pH was lower ( approximate to 7) and copper was high. These characteristics would allow this species to bloom in highly copper-stressed environments that would characteristically have a low pH. From this work, and related studies, we concluded that the primary mechanism allowing O. pusilla to reduce ionic-copper activity in culture solutions and microcosms was the release of organic copper-complexing ligands and that biomass sorption may have been important only at very high cell densities. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Environm Conservat Div, NW Fisheries Sci Ctr, E Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98195 USA. RP Meador, JP (reprint author), NOAA, Environm Conservat Div, NW Fisheries Sci Ctr, 2725 Montlake Blvd, E Seattle, WA 98112 USA. EM Jatnes.Meador@noaa.gov RI Taub, Frieda /K-8858-2013 NR 43 TC 8 Z9 8 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD DEC PY 1998 VL 44 IS 1-2 BP 69 EP 82 DI 10.1016/S0166-445X(98)00067-8 PG 14 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA 153UD UT WOS:000077850300005 ER PT J AU Damineli, A Stahl, O Kaufer, A Wolf, B Quast, G Lopes, DF AF Damineli, A Stahl, O Kaufer, A Wolf, B Quast, G Lopes, DF TI Long-term spectroscopy of eta Carinae - I. The high and low excitation phases SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE stars : emission-line, Be; stars : Hertzsprung-Russel (HR) diagram; stars : individual : eta Carinae; binaries : general ID INFRARED-SPECTRUM; ULTRAVIOLET; VARIABILITY; EJECTA; LINES; CORE AB Quantitative measurements of line parameters in the spectrum of eta Carinae are presented for both the broad and narrow line components. A total of 655 spectral features were measured in the spectral range 3850 Angstrom to 11000 Angstrom, giving a comprehensive view of the behavior of atomic transitions ranging from a few to tens of electron volts. The spectrum on the phase of maximum intensity in the high excitation lines (1995) is compared with that on minimum intensity (June 1992), showing that at this phase the high excitation Lines disappear but the broad components of low excitation lines strengthens. We reject a number of previous line identifications and propose several new ones, including Fe II, [Fe II], [Fe III], [N II], and the near-infrared Ca II triplet. Some lines commonly used to diagnose density, temperature, chemical composition, and reddening were found to be blended, urging a revision of the results based on previous data. The existence of double-peaked lines, suggested in previous papers, is ruled out. In the case of hydrogen lines, the apparent double-peaks are shown to be real absorption components. The velocity field in the inner 2 " around the central star shows additional components previously unknown. The phases of high and low excitation in eta Carinae are discussed in light of a recently proposed binary system. We suggest a temperature T similar to 16000 K for the primary star, what indicates that it is close to the beginning of the core helium-bunting evolutionary stage. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany. Observ Nacl, BR-20921440 Rio De Janeiro, Brazil. CNPq, Lab Nacl Astrofis, BR-37500000 Itajuba, Brazil. Univ Sao Paulo, Inst Astron & Geofis, BR-04301904 Sao Paulo, Brazil. RP Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM damineli@iagusp.usp.br RI Damineli, Augusto/D-8210-2012 OI Damineli, Augusto/0000-0002-7978-2994 NR 49 TC 56 Z9 56 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD DEC PY 1998 VL 133 IS 3 BP 299 EP 316 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 153TM UT WOS:000077848800001 ER PT J AU Hamilton, K AF Hamilton, K TI Dynamics of the tropical middle atmosphere: A tutorial review SO ATMOSPHERE-OCEAN LA English DT Article; Proceedings Paper CT Canadian Middle Atmosphere Modelling Project Summer School CY AUG, 1997 CL CORNWALL, CANADA ID QUASI-BIENNIAL OSCILLATION; STRATOPAUSE SEMIANNUAL OSCILLATION; GENERAL-CIRCULATION MODEL; EQUATORIAL PLANETARY WAVES; ZONAL WIND OSCILLATION; LOWER STRATOSPHERE; NUMERICAL-MODEL; GRAVITY-WAVES; KELVIN WAVE; OZONE AB The general circulation of the tropical stratosphere, mesosphere and lowermost thermosphere is discussed at a tutorial level. Observations of the quasi-biennial and semiannual oscillations by both in situ and satellite techniques are first reviewed. The basic dynamics controlling the zonal-mean component of the circulation are then discussed The role of radiative diabatic cooling in constraining the zonal-mean circulation in the middle atmosphere is emphasized. It is shown that the effectiveness of this radiative constraint is reduced at low latitudes, allowing for the sustained mean flaw accelerations over long period of time characteristic of the quasi-biennial and semiannual oscillations in the tropics. The current view is that the dominant driving for the equatorial mean paw accelerations seen in the middle atmosphere derives from vertically-propagating waves. This process is illustrated here in its simplest context, Le. the plumb (1977) model of the interaction of monochromatic internal gravity waves with the mean flow (based on earlier work of Lindzen and Holton, 1968; Holton and Lindzen, 1972). It is shown that the dynamics illustrated by this simple model can serve as the basis for an explanation of the quasi-biennial oscillation. The paper then describes some of recent developments in the theory of the quasi-biennial and semiannual oscillations, including aspects related to the inter-action between tropics and midlatitudes in the middle atmosphere. The paper concludes with a discussion of the effects of the long period dynamical variations in the tropical circulation on the chemical composition of the stratosphere. C1 Princeton Univ, GFDL NOAA, Princeton, NJ 08542 USA. RP Hamilton, K (reprint author), Princeton Univ, GFDL NOAA, Princeton, NJ 08542 USA. NR 102 TC 14 Z9 14 U1 0 U2 2 PU CANADIAN METEOROLOGICAL OCEANOGRAPHIC SOC PI OTTAWA PA 150 LOUIS PASTEUR PVT., STE 112, MCDONALD BUILDING, OTTAWA, ONTARIO K1N 6N5, CANADA SN 0705-5900 J9 ATMOS OCEAN JI Atmos.-Ocean PD DEC PY 1998 VL 36 IS 4 BP 319 EP 354 PG 36 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 167VY UT WOS:000078655900002 ER PT J AU Draxier, RR Hess, GD AF Draxier, RR Hess, GD TI An overview of the HYSPLIT_4 modelling system for trajectories, dispersion and deposition SO AUSTRALIAN METEOROLOGICAL MAGAZINE LA English DT Article ID GASEOUS DRY DEPOSITION; SURFACE RESISTANCES; BOUNDARY-LAYER; TRANSPORT; ANATEX; FLUX; PARAMETERIZATION AB The HYSPLIT_4 (HYbrid Single-Particle Lagrangian Integrated Trajectory) model is designed for quick response to atmospheric emergencies, diagnostic case studies, or climatological analyses using previously gridded meteorological data. Calculations mag be performed sequentially on multiple meteorological grids, going from fine to coarse resolution and using either archive or forecast data fields. Air concentration calculations associate the mass of the pollutant species with the release of either puffs, particles, or a combination of both. The dispersion rate is calculated from the vertical diffusivity profile, wind shear, and horizontal deformation of the mind field. Air concentrations are calculated at a specific grid-point for puffs and as cell-average concentrations for particles. The model results are evaluated against ACE balloon trajectories, air concentrations from the ANATEX tracer experiment, radiological deposition from the Chernobyl accident, and satellite photographs of the Rabaul volcanic eruption. One common feature of the model results was their sensitivity to the vertical atmospheric structure; trajectories in terms of their height when near ground-level due to the strong gradients of wind speed and direction, air concentrations with respect to the rate of vertical mixing, and deposition as a result of the vertical distribution of the pollutant. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. Bur Meteorol Res Ctr, Melbourne, Vic, Australia. RP Draxier, RR (reprint author), 1315 E West Highway,Room 3151, Silver Spring, MD 20910 USA. NR 39 TC 1280 Z9 1401 U1 21 U2 151 PU AUSTRALIAN GOVT PUBL SERV PI CANBERRA PA PO BOX 84, CANBERRA, 2601, AUSTRALIA SN 0004-9743 J9 AUST METEOROL MAG JI Aust. Meteorol. Mag. PD DEC PY 1998 VL 47 IS 4 BP 295 EP 308 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 166TZ UT WOS:000078594400003 ER PT J AU Clarke, WB Clarke, RM Olson, EK Barr, RD Downing, RG AF Clarke, WB Clarke, RM Olson, EK Barr, RD Downing, RG TI Binding of lithium and boron to human plasma proteins SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article DE lithium; boron; plasma proteins; alcohol precipitation; gel chromatography; neutron activation; mass spectrometry ID MONOZYGOTIC-DIZYGOTIC TWIN; GEL-FILTRATION; HUMAN-BLOOD; GENETIC DETERMINANT; ION DISTRIBUTION; ESSENTIALITY; SERUM; ZINC AB The binding of lithium and boron, at normal physiological levels, to plasma proteins has been investigated by the techniques of precipitation with ethyl alcohol and gel chromatography. Assays of lithium and boron were made by thermal neutron activation and mass spectrometric assay of He-3 and He-4. Results of alcohol precipitation experiments for plasma from two apparently healthy donors showed that 13 +/- 4% and 16 +/- 3% of the lithium in plasma is protein bound, but essentially no boron is bound under the conditions used. We believe that because of denaturation of proteins which occurs during alcohol precipitation, these percentages represent lithium and boron tightly bound to protein molecules. The results of the gel-chromatography experiment, on the other hand, showed that lithium and boron are bound to a wide range of plasma proteins, from low (similar to 60,000 amu) to high (similar to 1,000,000 amu) molecular weights, and to very low- (similar to 6000 amu) molecular-weight ligands. Although a clear identification of the specific proteins which bind lithium and boron cannot be made at present, some possibilities can be suggested. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. McMaster Univ, Dept Pediat, Hamilton, ON, Canada. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Clarke, WB (reprint author), McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. NR 32 TC 5 Z9 5 U1 1 U2 2 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 DEC PY 1998 VL 65 IS 3 BP 237 EP 249 DI 10.1007/BF02789099 PG 13 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 155WT UT WOS:000077969900006 PM 9892496 ER PT J AU Woodhouse, CA Overpeck, JT AF Woodhouse, CA Overpeck, JT TI 2000 years of drought variability in the central United States SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Review ID NORTH-AMERICAN DROUGHT; ATMOSPHERIC CIRCULATION PATTERNS; QUATERNARY EOLIAN DEPOSITION; SEA-SURFACE TEMPERATURE; MEDIEVAL WARM PERIOD; CENTRAL GREAT-PLAINS; NEBRASKA SAND HILLS; TREE-RING RECORDS; LOW-LEVEL JET; COLORADO PLATEAUS AB Droughts are one of the most devastating natural hazards faced by the United States today. Severe droughts of the twentieth century have had large impacts on economies, society, and the environment, especially in the Great Plains. However, the instrumental record of the last 100 years contains only a limited subset of drought realizations. One must turn to the paleoclimatic record to examine the full range of past drought variability, including the range of magnitude and duration, and thus gain the improved understanding needed for society to anticipate and plan for droughts of the future. Historical documents, tree rings, archaeological remains, lake sediment, and geomorphic data make it clear that the droughts of the twentieth century, including those of the 1930s and 1950s, were eclipsed several times by droughts earlier in the last 2000 years, and as recently as the late sixteenth century. In general, some droughts prior to 1600 appear to be characterized by longer duration (i.e., multidecadal) and greater spatial extent than those of the twentieth century. The authors' assessment of the full range of past natural drought variability, deduced from a comprehensive review of the paleoclimatic literature, suggests that droughts more severe than those of the 1930s and 1950s are likely to occur in the future, a likelihood that might be exacerbated by greenhouse warming in the next century. Persistence conditions that lead to decadal-scale drought may be related to low-frequency variations, or base-state shifts, in both the Pacific and Atlantic Oceans, although more research is needed to understand the mechanisms of severe drought. C1 NOAA, NGDC, World Data Ctr Paleoclimatol, Paleoclimatol Program, Boulder, CO 80303 USA. Univ Colorado, INSTAAR, Boulder, CO 80309 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. RP Woodhouse, CA (reprint author), NOAA, NGDC, World Data Ctr Paleoclimatol, Paleoclimatol Program, 325 Broadway, Boulder, CO 80303 USA. NR 130 TC 347 Z9 380 U1 13 U2 61 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 1998 VL 79 IS 12 BP 2693 EP 2714 DI 10.1175/1520-0477(1998)079<2693:YODVIT>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VT UT WOS:000077967600003 ER PT J AU Paxton, CH Sobien, DA AF Paxton, CH Sobien, DA TI Resonant interaction between an atmospheric gravity wave and shallow water wave along Florida's west coast SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID DAYTONA-BEACH; SQUALL-LINE AB On 25 March 1995, a large solitary wave, seemingly from nowhere, washed ashore along the normally tranquil Gulf Coast of Florida from Tampa Bay to south of Naples. On this Saturday morning, many beachgoers and coastal residents saw either a large wave, a surge, or a seiche. The wave was typically described as 3 m or greater, breaking between 0.5 and 3 km offshore, and taking 120-180 a to arrive at the shore. Just prior to the wave's arrival at the beach, witnesses reported a rapid runout of water, then a huge 15-25-m runup of water onto the beach corresponding to a 2-3-m vertical run-up height. Some people reported several smaller waves. This was likely due to local effects. This wave was generated and amplified by a large-amplitude atmospheric gravity wave transiting southeastward over the eastern Gulf of Mexico. The atmospheric gravity wave and the water wave moved over a channel of water depth sufficient to maintain the waves in phase allowing resonation of the shallow water wave. Surface winds appeared to have a negligible affect, increasing only slightly (3-5 m s(-1)) along the path of the atmospheric gravity wave and opposing propagation of the water wave. C1 NOAA, NWS, Tampa, FL USA. RP Sobien, DA (reprint author), 2525 14th Ave SE, Ruskin, FL 33570 USA. NR 13 TC 12 Z9 12 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1998 VL 79 IS 12 BP 2727 EP 2732 DI 10.1175/1520-0477(1998)079<2727:RIBAAG>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VT UT WOS:000077967600005 ER PT J AU Snook, JS AF Snook, JS TI Comments on "Regional real-time numerical weather prediction: Current status and future potential" SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter ID OPERATIONAL USE; LAPS C1 NOAA, Forecast Syst Lab, Boulder, CO USA. RP Snook, JS (reprint author), NOAA, Forecast Syst Lab, Boulder, CO USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1998 VL 79 IS 12 BP 2747 EP 2748 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VT UT WOS:000077967600008 ER PT J AU Kalnay, E Lord, SJ McPherson, RD AF Kalnay, E Lord, SJ McPherson, RD TI Maturity of operational numerical weather prediction: Medium range SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID NATIONAL-METEOROLOGICAL-CENTER; HYDROSTATIC QUALITY-CONTROL; REGIONAL-ANALYSIS SYSTEM; ENSEMBLE PREDICTION; INITIAL CONDITIONS; FORECAST SYSTEM; ETA-MODEL; NMC; NCEP; INTERPOLATION AB In 1939 Rossby demonstrated the usefulness of the linearized perturbation of the equations of motion for weather prediction and thus made possible the first successful numerical forecasts of the weather by Charney et al. In 1951 Charney wrote a paper on the science of numerical weather prediction (NWP), where he predicted with remarkable vision how NWP would evolve until the present. In the 1960's Lorenz discovered that the chaotic nature of the atmosphere imposes a finite limit of about two weeks to weather predictability. At that time this fundamental discovery was "only of academic interest" and not really relevant to operational weather forecasting, since at that time the accuracy of even a 2-day forecast was rather poor. Since then, however, computer-based forecasts have improved so much that Lorenz's a Limit of predictability is starting to become attainable in practice, especially with ensemble forecasting, and the predictabilty of longer-lasting phenomena such as El Nino is beginning to be successfully exploited. The skill of operational weather forecasts has at least doubled over the last two decades. This improvement has taken place relatively steadily, driven by a large number of scientific and computational developments, especially in the area of NWP. It has taken place in all the operational NWP centers, as friendly competition and information sharing make scientific improvements take place faster than they would in a single center. Because the improvements have occurred steadily, rather than suddenly, the overall increase in forecast skill due to NWP has not been clearly recognized by the media and the public despite the impact that improved forecasts have on the national economy and on the Lives of every American. In this paper the authors review several measures of operational forecast skill that quantify improvements in NWP at the National Centers for Environmental Prediction (NCEP, formerly the National Meteorological Center) of the National Weather Service, although they are representative of improvements in all major NWP operational centers. The authors point out that there are three major requirements for improved numerical weather prediction: better atmospheric models, better observational data, and better methods for data assimilation. These improvements are generally very computer intensive and can only be made operational with the availability of more powerful supercomputers. Operational forecasts are compared with "reforecasts" from the NCEP-NCAR 40-Year Reanalysis, showing that, if the present-day NWP systems had been available many decades ago, skillful 5-day forecasts would have been possible in the Northern Hemisphere with the upper-air network of the late 1950s. The authors discuss new approaches in the use of observations (variational assimilation of remote observations) and of numerical weather prediction guidance (ensemble forecasting) that have allowed the recent extension of operational predictions into longer ranges and the possibility of adaptive observing systems. The extension of operational forecast skill into seasonal predictions of the El Nino-Southern Oscillation phenomena using coupled ocean-atmosphere models is also discussed. In the last section the authors attempt to "forecast" the future of NWP. C1 Natl Ctr Environm Predict, Washington, DC USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. RP Kalnay, E (reprint author), Energy Ctr, 100 E Boyd,Room 1310, Norman, OK 73019 USA. EM ekalnay@ou.edu RI Kalnay, Eugenia/F-4393-2010; OI Kalnay, Eugenia/0000-0002-9984-9906 NR 71 TC 57 Z9 61 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1998 VL 79 IS 12 BP 2753 EP 2769 DI 10.1175/1520-0477(1998)079<2753:MOONWP>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155VT UT WOS:000077967600010 ER PT J AU Grant, WS Clark, AM Bowen, BW AF Grant, WS Clark, AM Bowen, BW TI Why restriction fragment length polymorphism analysis of mitochondrial DNA failed to resolve sardine (Sardinops) biogeography: insights from mitochondrial DNA cytochrome b sequences SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID GENETIC-STRUCTURE; POPULATION-STRUCTURE; CLUPEA-HARENGUS; MOLECULAR CLOCK; EASTERN GULF; EVOLUTION; ATLANTIC; PATTERNS; PACIFIC; MEXICO AB Restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of mitochondrial DNA (mtDNA) have generated conflicting hypotheses on the phylogeography of Indian-Pacific clupeid Sardinops. An RFLP analysis of the control region and adjoining segments indicates a phylogenetic affiliation between southern Africa Australian and Japanese sardines whereas comparisons of an overlapping segment of the control region sequence indicate an affiliation between southern Africa - Australian and Chile-Californian sardines. An analysis of 258 bp, of mtDNA cytochrome b in 74 individuals of Sardinops from South Africa, Australia, Chile, California, and Japan revealed 24 haplotypes, resulting in high levels of haplotypic (h) diversity (average h = 0.70), low levels of nucleotide (pi) diversity (average pi = 0.005), and a satisfactory level of divergence (d) for population resolution (d(max) = 4.02%). Cluster and parsimony analyses of haplotypic divergences confirmed the existence of three lineages corresponding to southern Africa - Australia, Chile-California, and Japan but failed to confirm a biogeographic connection between Australia and Japan. These results support the model based on control region sequences and highlight potential pitfalls of RFLP analyses of highly polymorphic DNA sequences with numerous homoplaseous transitions. A comparaison of 220 bp of cytochrome b in samples of Sardina and Sardinops produced an average sequence divergence of 23.2% and supports an ancient divergence between Sardina and Sardinops. The three lineages of Indian-Pacific Sardinops may merit subspecies recognition, based on low but significant levels of mtDNA divergence between them and on evidence of separations between these groups on the order of 200 000 - 500 000 years. C1 NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. Univ Florida, Gainesville, FL 32611 USA. Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. RP NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM stew.grant@noaa.gov NR 46 TC 28 Z9 28 U1 0 U2 5 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 1998 VL 55 IS 12 BP 2539 EP 2547 DI 10.1139/cjfas-55-12-2539 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 164GU UT WOS:000078455500002 ER PT J AU Cortes, E AF Cortes, E TI Methods of studying fish feeding: reply SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID STOMACH CONTENTS C1 Natl Marine Fisheries Serv, Inst Fishery Resource Ecol, Panama City, FL 32408 USA. Florida State Univ, Panama City, FL 32408 USA. RP Cortes, E (reprint author), Natl Marine Fisheries Serv, Inst Fishery Resource Ecol, 3500 Delwood Beach Rd, Panama City, FL 32408 USA. NR 5 TC 16 Z9 21 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 1998 VL 55 IS 12 BP 2708 EP 2708 DI 10.1139/cjfas-55-12-2708 PG 1 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 164GU UT WOS:000078455500016 ER PT J AU Adlerstein, SA Dorn, MW AF Adlerstein, SA Dorn, MW TI The effect of Kudoa paniformis infection on the reproductive effort of female Pacific hake SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID MERLUCCIUS-PRODUCTUS AYRES; FECUNDITY; MULTIVALVULIDA; RECRUITMENT; BIOLOGY AB The effect of the myxosporidean Kudoa paniformis on the annual reproductive effort of the coastal stock of Pacific hake (Merluccius products), on which it is a common parasite, is investigated. Female Pacific hake collected off the central Oregon coast in December 1988 were analyzed for prevalence and intensity of parasites. Reproductive effort was estimated by the number of yolked oocytes present in the ovaries immediately prior to spawning (potential annual fecundity), using the volumetric method. The effect of the parasite was evaluated through an analysis of covariance where fecundity was modeled as a function of fish length and parasite prevalence. An additional analysis of covariance evaluated the effect of the intensity of parasite infection on fecundity. Results show that the fecundity of Pacific hake is significantly reduced in the presence of K. paniformis infections and that the detrimental effect escalates with the intensity of infection. The potential effects on the population dynamics of the Pacific hake coastal stock are discussed. C1 Univ Washington, Sch Fisheries, Seattle, WA 98119 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Adlerstein, SA (reprint author), Univ Hamburg, Inst Fishereiwissensch, Olbersweg 24, D-22767 Hamburg, Germany. NR 22 TC 6 Z9 6 U1 1 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD DEC PY 1998 VL 76 IS 12 BP 2285 EP 2289 DI 10.1139/cjz-76-12-2285 PG 5 WC Zoology SC Zoology GA 211WM UT WOS:000081184900019 ER PT J AU Vichit-Vadakan, W Carino, NJ Mullings, GM AF Vichit-Vadakan, W Carino, NJ Mullings, GM TI Effect of elastic modulus of capping material on measured strength of high-strength concrete cylinders SO CEMENT CONCRETE AND AGGREGATES LA English DT Article DE cap thickness; capping materials; compressive strength; elastic modulus; high-strength concrete; modified cube strength; resonant frequency testing AB Studies have shown that end conditions of concrete cylinders tested in compression can have a significant effect on the measured strength of the cylinders, especially when high-strength concrete is used. The ASTM standard for bonded caps has requirements for minimum cube strength of the capping material and maximum cap thickness. However, a study by researchers at the National Ready Mixed Concrete Association (NRMCA) showed that the 50 mm cube strength may not be very useful in determining whether the capping material will perform adequately when testing high-strength concrete. In the study reported in this paper, the dynamic modulus of elasticity and modified cube strength (ASTM C 116) of various capping materials were evaluated as a function of age. The results showed that each capping material has a unique relationship between dynamic elastic modulus and cube strength. The elastic modulus of different capping materials can vary greatly at a given cube strength. For example, at a modified cube strength of 80 MPa, the elastic modulus of neat cement paste, at 30 GPa, was twice the elastic modulus of one sulfur mortar, at only 15 GPa. The elastic modulus of the capping materials was correlated with previously reported cylinder strengths. In cases where the cylinder strength was affected by the capping material, there is evidence that the cylinder strength was related to the modulus of elasticity and not to the cube strength of the capping material. C1 Princeton Univ, Princeton, NJ 08544 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Ready Mixed Concrete Assoc, Silver Spring, MD 20910 USA. RP Vichit-Vadakan, W (reprint author), Princeton Univ, Princeton, NJ 08544 USA. NR 9 TC 5 Z9 6 U1 0 U2 5 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0149-6123 J9 CEMENT CONCRETE AGGR JI Cem. Concr. Aggreg. PD DEC PY 1998 VL 20 IS 2 BP 227 EP 234 PG 8 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 184PY UT WOS:000079622600002 ER PT J AU Ferraris, CF de Larrard, F AF Ferraris, CF de Larrard, F TI Modified slump test to measure rheological parameters of fresh concrete SO CEMENT CONCRETE AND AGGREGATES LA English DT Article DE concrete rheology; slump test; plastic viscosity; yield stress; workability field test AB The ease of placement of concrete depends upon at least two physical properties, the yield stress and plastic viscosity. Currently the most common field test is the slump test, and it is related only to the yield stress. Therefore, a simple field test method intended to provide an evaluation of the two Bingham rheological parameters, yield stress and plastic viscosity, was developed. To determine the plastic viscosity the time necessary for the upper surface of the concrete in the standard slump cone to slump 100 mm was measured. The apparatus and test procedure are described. Semi-empirical models are proposed for the yield stress and for the plastic viscosity as function of the final slump and slumping time. The application of the modified slump test for the evaluation of the viscosity is limited to concretes with a slump of 120 to 260 mm. If the validity of this test is confirmed in the future, it could be used as a field quality control test. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Lab Cent Ponts & Chaussees, F-44340 Bouguenais, France. RP Ferraris, CF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 10 TC 28 Z9 31 U1 0 U2 14 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0149-6123 J9 CEMENT CONCRETE AGGR JI Cem. Concr. Aggreg. PD DEC PY 1998 VL 20 IS 2 BP 241 EP 247 PG 7 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 184PY UT WOS:000079622600004 ER PT J AU Babushok, V Tsang, W Linteris, GT Reinelt, D AF Babushok, V Tsang, W Linteris, GT Reinelt, D TI Chemical limits to flame inhibition SO COMBUSTION AND FLAME LA English DT Article ID CF3BR AB This paper deals with the ultimate limits of chemical contributions to flame inhibition. Particular attention is focussed on the inhibition cycles which regenerate the inhibitor. This leads to the definition of an idealized "perfect" inhibition cycle. It is demonstrated that for such an inhibitor in a stoichiometric methane/air flame, additive levels in the 0.001-0.01 mole percent range will lead to a decrease in flame velocity of approximately 30%. This efficiency corresponds roughly to the observed behavior of metallic inhibitors such as iron pentacarbonyl which is known to be as much as 2 orders of magnitude more effective than currently used suppressants. This correspondence between the behavior of a "perfect inhibitor" and iron carbonyl leads to the conclusion that only gas-phase processes can account for its inhibitive power. (C) 1998 by The Combustion Institute. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Babushok, V (reprint author), NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 30 TC 42 Z9 46 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1998 VL 115 IS 4 BP 551 EP 560 DI 10.1016/S0010-2180(98)00019-4 PG 10 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 103QU UT WOS:000074970000008 ER PT J AU Baum, HR Mell, WE AF Baum, HR Mell, WE TI A radiative transport model for large-eddy fire simulations SO COMBUSTION THEORY AND MODELLING LA English DT Article AB 3Three-dimensional simulations of fires cannot be performed on present-day computers without devising simplifications to the governing equations. One such method is the large-eddy simulation (LES) approach for fires developed at NIST. This method results in computationally efficient fire simulations in which the buoyancy-generated motion of hot gases and smoke is driven by Lagrangian particles that carry the heat released by combustion. Complex geometries are represented by blocking cells interior to a rectangular domain. A P1 approximation to the radiation transport equation was developed to be consistent with the exact transport equation for scenarios based upon this model. An isolated fire plume above a semiinfinite solid with a constant absorption coefficient in each half-space was studied as an example. A direct elliptic solver required only a fraction of the total LES computational cost. Radiative fluxes and intensities from the numerical and exact solutions to the P1 approximation were in excellent agreement. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Baum, HR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 15 TC 7 Z9 8 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD DEC PY 1998 VL 2 IS 4 BP 405 EP 422 DI 10.1088/1364-7830/2/4/004 PG 18 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 155YX UT WOS:000077975500004 ER PT J AU Lomax, DP Roubal, WT Moore, JD Johnson, LL AF Lomax, DP Roubal, WT Moore, JD Johnson, LL TI An enzyme-linked immunosorbent assay (ELISA) for measuring vitellogenin in English sole (Pleuronectes vetulus): development, validation and cross-reactivity with other pleuronectids SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY LA English DT Article DE biomarker; ELISA; English sole; environmental estrogens; vitellogenin ID SALMON ONCORHYNCHUS-KISUTCH; BASS MORONE-SAXATILIS; LABRAX L VITELLOGENIN; RAINBOW-TROUT; BENTHIC FISH; ESTROGENIC ACTIVITY; CYPRINUS-CARPIO; STARRY FLOUNDER; YOLK PROTEINS; PUGET-SOUND AB Vitellogenin (Vtg) is a folk protein produced in the liver of oviparous animals in response to estrogen. Vitellogenesis is normally observed only in sexually mature females, but it can be induced in male and juvenile animals by exposure to exogenous estradiol (E-2) or substances that mimic estrogens. The abnormal production of Vtg by males can, therefore, be used as a biological indicator for exposure to xenoestrogens. In this study, an enzyme-linked immunosorbent assay (ELISA) for measuring Vtg in English sole (Pleuronectes vetulus) was developed and validated. Plasmatic Vtg was purified from E-2-injected male English sole using DEAE ion-exchange and Sepharose size-exclusion chromatography, and polyclonal antibodies against the purified Vtg protein were generated in rabbits. In this assay, a competition for the Vtg antibody was established between Vtg coated onto microtiter plate wells and free Vtg. Detection of adsorbed antigen-antibody complexes was achieved using a horseradish peroxidase conjugated anti-rabbit secondary antibody whose enzyme activity was revealed with 3,3',5,5'-tetramethyl benzidine (TMB) substrate. Assay conditions provided a detectable Vtg range of 10-450 ng ml(-1) (85-20% of binding) of diluted sample. Plasma dilution curves from vitellogenic female and E-2-treated male English sole showed parallelism with the standard dilution curve. We are presently conducting field and laboratory studies to investigate estrogenic and anti-estrogenic activity resulting from exposure to contaminants. (C) 1998 Elsevier Science Inc. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Lomax, DP (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 53 TC 63 Z9 72 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0305-0491 J9 COMP BIOCHEM PHYS B JI Comp. Biochem. Physiol. B-Biochem. Mol. Biol. PD DEC PY 1998 VL 121 IS 4 BP 425 EP 436 DI 10.1016/S0305-0491(98)10125-6 PG 12 WC Biochemistry & Molecular Biology; Zoology SC Biochemistry & Molecular Biology; Zoology GA 151RE UT WOS:000077733800009 PM 9972314 ER PT J AU Liu, HC Hong, TH Herman, M Camus, T Chellappa, R AF Liu, HC Hong, TH Herman, M Camus, T Chellappa, R TI Accuracy vs efficiency trade-offs in optical flow algorithms SO COMPUTER VISION AND IMAGE UNDERSTANDING LA English DT Article DE low level processing; motion; optical flow; evaluation; real-time implementation ID IMAGE SEQUENCES; MOTION; COMPUTATION; FRAMEWORK; TRACKING; VELOCITY; OBJECT; SYSTEM; VISION AB There have been two thrusts in the development of optical flow algorithms. One has emphasized higher accuracy; the other faster implementation. These two thrusts, however, have been independently pursued, without addressing the accuracy vs efficiency trade-offs. Although the accuracy-efficiency characteristic is algorithm dependent, an understanding of a general pattern is crucial in evaluating an algorithm as far as real-world tasks are concerned, which often pose various performance requirements. This paper addresses many implementation issues that have often been neglected in previous research, including temporal filtering of the output stream, algorithms' flexibility, and robustness to noise, subsampling, etc. Their impacts on accuracy and/or efficiency are emphasized. We present a survey of different approaches toward the goal of higher performance and present experimental studies on accuracy vs efficiency trade-offs. A detailed analysis of how this trade-off affects algorithm design is manifested in a case study involving two state-of-the-art optical flow algorithms: a gradient and a correlation-based method, The goal of this paper is to bridge the gap between the accuracy-and the efficiency-oriented approaches. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Elect Engn, Ctr Automat Res, College Pk, MD 20742 USA. RP Natl Inst Stand & Technol, Intelligent Syst Div, Blg 220,Rm B124, Gaithersburg, MD 20899 USA. EM liu@cme.nist.gov; hongt@cme.nist.gov; herman@cme.nist.gov; tac@cme.nist.gov; rama@cfar.umd.edu NR 55 TC 80 Z9 82 U1 6 U2 9 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3142 EI 1090-235X J9 COMPUT VIS IMAGE UND JI Comput. Vis. Image Underst. PD DEC PY 1998 VL 72 IS 3 BP 271 EP 286 DI 10.1006/cviu.1998.0675 PG 16 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 144ZW UT WOS:000077347200004 ER PT J AU Graebner, JE Altmann, H Balzaretti, NM Campbell, R Chae, HB Degiovanni, A Enck, R Feldman, A Fournier, D Fricke, J Goela, JS Gray, KJ Gu, YQ Hatta, I Hartnett, TM Imhof, RE Kato, R Koidl, P Kuo, PK Lee, TK Maillet, D Remy, B Roger, JP Seong, DJ Tye, RP Verhoeven, H Worner, E Yehoda, JE Zachai, R Zhang, B AF Graebner, JE Altmann, H Balzaretti, NM Campbell, R Chae, HB Degiovanni, A Enck, R Feldman, A Fournier, D Fricke, J Goela, JS Gray, KJ Gu, YQ Hatta, I Hartnett, TM Imhof, RE Kato, R Koidl, P Kuo, PK Lee, TK Maillet, D Remy, B Roger, JP Seong, DJ Tye, RP Verhoeven, H Worner, E Yehoda, JE Zachai, R Zhang, B TI Report on a second round robin measurement of the thermal conductivity of CVD diamond SO DIAMOND AND RELATED MATERIALS LA English DT Review DE CVD diamond; round robin measurement; thermal conductivity; silicon carbide; aluminum nitride ID AC CALORIMETRIC METHOD; VAPOR-DEPOSITED DIAMOND; DIFFUSIVITY MEASUREMENT; THIN-FILMS; PHONON-SCATTERING; HEAT AB The results of a round robin series of measurements of the thermal conductivity and thermal diffusivity of chemical-vapor-deposited (CVD) diamond are reported. The present round robin (RR2) is an outgrowth of an earlier series (RR1) aimed at understanding which measurement techniques are best suited to measuring the high conductivity of CVD diamond. RR2 includes diamond specimens of higher homogeneity, non-diamond specimens of lower conductivity as controls, and measurements by 14 laboratories using five techniques, with all techniques but one used by more than one laboratory. The data are converted to thermal conductivity at 25 degrees C to facilitate comparisons among specimens and laboratories. The statistical analysis excludes outliers using Chauvenet's criterion, resulting in data from typically two or three laboratories being excluded for each specimen. The analysis arrives at mean values in the range 1300-2000 W m(-1) K-1 for the diamond samples, as expected because of the conditions of preparation, with uncertainties in the range 1.5-4%. For the non-diamond materials, SIC and AIN, the results are 268 W m(-1) K-1 +/- 2.2% and 178 W m(-1) K-1 +/- 2.5%, respectively. Comparing techniques, the d.c.-heated bar is found to be the most accurate, typically +/-5% or better. Under favorable conditions, Angstrom's thermal wave method can apparently yield relative uncertainties of +/-5-10%, and the mirage effect +/-5-15%. Too few laboratories used the transient thermal grating and laser flash methods to make general comments on their accuracy, but one expects a comparable accuracy if used on specimens that are fine-grained and thermally isotropic. Deviations, sometimes large, from these optimal accuracies are examined, and it is suggested that certain experimental details are important for achieving accuracy. It is also found that the estimates of experimental uncertainty provided by most laboratories seriously underestimate the actual deviations of their data from the mean conductivity. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Wurzburg, D-97074 Wurzburg, Germany. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. UFRGS, Inst Fis, BR-91501 Porto Alegre, RS, Brazil. Holometrix Inc, Bedford, MA 01730 USA. Soonchunhyang Univ, Choongnam, South Korea. ENSEM, LEMTA, F-54504 Vandoeuvre Nancy, France. Carborundum Microelect, Phoenix, AZ 85008 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Paris 06, F-75005 Paris, France. Morton Int, Woburn, MA 01801 USA. Norton Diamond Film, Northborough, MA 01532 USA. Tsing Hua Univ, Beijing 100084, Peoples R China. Nagoya Univ, Nagoya, Aichi 46901, Japan. Raytheon Co, Lexington, MA 01273 USA. S Bank Univ, London SE1 0AA, England. Ulvac Sinku Riko Inc, Yokohama, Kanagawa 226, Japan. Fraunhofer Inst Angew Festkorperphys, IAF, D-79108 Freiburg, Germany. Wayne State Univ, Detroit, MI 48201 USA. Korea Inst Stand & Sci, Taejon 305600, South Korea. Diamonex, Allentown, PA 18106 USA. Daimler Benz AG, D-7900 Ulm, Germany. RP Graebner, JE (reprint author), AT&T Bell Labs, Lucent Technol, 600 Mt Ave, Murray Hill, NJ 07974 USA. RI Balzaretti, Naira/L-3417-2014; OI Balzaretti, Naira/0000-0003-2797-8618; Denis, Maillet/0000-0002-5663-485X NR 37 TC 27 Z9 27 U1 2 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD DEC PY 1998 VL 7 IS 11-12 BP 1589 EP 1604 DI 10.1016/S0925-9635(98)00241-6 PG 16 WC Materials Science, Multidisciplinary SC Materials Science GA 149QR UT WOS:000077617300002 ER PT J AU Boveng, PL Hiruki, LM Schwartz, MK Bengtson, JL AF Boveng, PL Hiruki, LM Schwartz, MK Bengtson, JL TI Population growth of Antarctic fur seals: Limitation by a top predator, the leopard seal? SO ECOLOGY LA English DT Article DE Arctocephalus gazella; breeding chronology; Hydrurga leptonyx; mortality rate; population recovery; population growth rare; predation; pup production; South Shetland Islands; top-down limitation ID ARCTOCEPHALUS-GAZELLA PETERS; SOUTH-GEORGIA; BREEDING-SEASON; HEARD-ISLAND; BIRD-ISLAND; ICE EXTENT; MORTALITY; DIET; BEHAVIOR; AGE AB Antarctic fur seals (Arctocephalus gazella) in the South Shetland Islands are recovering from 19th-century exploitation more slowly than the main population at South Georgia. To document demographic changes associated with the recovery in the South Shetlands, we monitored fur seal abundance and reproduction in the vicinity of Elephant Island during austral summers from 1986/1987 through 1994/1995. Total births, mean and variance of birth dates, and average daily mortality rates were estimated from daily live pup counts at North Cove (NC) and North Annex (NA) colonies on Seal Island. Sightings of leopard seals (Hydrurga leptonyx) and incidents of leopard seal predation on fur seal pups were recorded opportunistically during daily fur seal research at both sites. High mortality of fur seal pups, attributed to predation by leopard seals frequently observed at NC, caused pup numbers to decline rapidly between January and March (i.e., prior to weaning) each year and probably caused a long-term decline in the size of that colony. The NA colony, where leopard seals were never observed, increased in size during the study. Pup mortality from causes other than leopard seal predation appeared to be similar at the two sites. The number of pups counted at four locations in the Elephant Island vicinity increased slowly, at an annual rate of 3.8%, compared to rates as high as 11% at other locations in the South Shetland Islands. Several lines of circumstantial evidence are consistent with the hypothesis that leopard seal predators limit the growth of the fur seal population in the Elephant Island area and perhaps in the broader population in the South Shetland Islands. The sustained growth of this fur seal population over many decades rules out certain predator-prey models, allowing inference about the interaction between leopard seals and fur seals even though it is less thoroughly studied than predator-prey systems of terrestrial vertebrates of the northern hemisphere. Top-down forces should be included in hypotheses for future research on the factors shaping the recovery of the fur seal population in the South Shetland Islands. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Boveng, PL (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way NE,Bin C15700, Seattle, WA 98115 USA. RI Schwartz, Michael/C-3184-2014 OI Schwartz, Michael/0000-0003-3521-3367 NR 73 TC 48 Z9 49 U1 16 U2 44 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD DEC PY 1998 VL 79 IS 8 BP 2863 EP 2877 DI 10.1890/0012-9658(1998)079[2863:PGOAFS]2.0.CO;2 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 148JF UT WOS:000077501000021 ER PT J AU Cole, KD AF Cole, KD TI Preparative separation of plasmid and bacterial artificial chromosome DNA by density gradient electrophoresis in the presence of linear polymers SO ELECTROPHORESIS LA English DT Article DE DNA electrophoresis; density gradient; linear polymers; bacterial artificial chromosome DNA; plasmid DNA ID CAPILLARY ELECTROPHORESIS; PROTEINS; POLYACRYLAMIDE; ORIENTATION; ORGANELLES; GEL AB A density gradient apparatus was used to examine the separation of different physical forms and sizes of DNA. A gradient of sucrose was used to stabilize thermal convection during electrophoresis in the column (2.2 cm in diameter). Linear polymers were added to the density gradient and screened for their ability to separate the supercoiled, nicked circular, and linear forms of the plasmid pBR 322. The influence of different concentrations and molecular weights of the polymers was examined on the separation. Polyethylene oxide with a molecular weight of 5 000 000 and a concentration of 0.2% w/v achieved the best separation results for the different physical forms of the plasmid. The order of separation of the different physical forms of the plasmid were linear (fastest), supercoiled, and nicked circular (slowest). These conditions were also used to separate a preparation of bacterial artificial chromosome (BAC) DNA. A rapidly moving form, presumably the supercoiled form, was resolved from a large amount of E. coli genomic DNA and from sheared forms of the BAC DNA. C1 NIST, Div Biotechnol, Bioproc Engn Grp, Gaithersburg, MD 20899 USA. RP Cole, KD (reprint author), NIST, Div Biotechnol, Bioproc Engn Grp, Bldg 222,Room A353, Gaithersburg, MD 20899 USA. EM cole@mailserver.nist.gov NR 28 TC 2 Z9 2 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD DEC PY 1998 VL 19 IS 18 BP 3062 EP 3068 DI 10.1002/elps.1150191803 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 159ZA UT WOS:000078204800002 PM 9932794 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Contrasting behavioral responses to cold temperatures by two marine fish species during their pelagic juvenile interval SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE fish behavior; diel patterns; activity; temperature ID POLLOCK THERAGRA-CHALCOGRAMMA; WALLEYE POLLOCK; VERTICAL-DISTRIBUTION; FOOD; THERMOCLINES; PATTERNS; GROWTH; PALLAS; LIGHT AB Motor activity of juvenile walleye pollock, Theragra chalcogramma, and sablefish, Anoplopoma fimbria, was monitored in the laboratory during high and low light levels under a changing temperature regime over a 5 d period. Water temperatures were ambient (12 degrees C) for the first 24 h of observation, rapidly lowered to 3 degrees C for the next 48 h, then raised back to 12 degrees C for the final 48 h. We hypothesized that the fishes' behavior would either follow a simple bioenergetic response of lowered activity associated with reduced metabolic rates at the colder temperature, or an avoidance response, with increased activity at decreased temperatures. Results for walleye pollock were consistent with a bioenergetic response, with activity decreasing in the presence of cold water under both high and low light levels, then returning to initial levels when temperatures increased. The response of sablefish, in contrast, indicated avoidance of cold temperatures, depending on light level. During high light, when sablefish were typically highly active, cold water induced a slight but insignificant decrease in activity. At low light, however, the presence of cold water caused a marked increase in sablefish movement through the experimental tanks, with a seven fold increase in the measured index of activity. When water temperatures were raised back to 12 degrees C, sablefish activity at low light returned to its normal, minimal level. The sharp increase in activity of sablefish in cold water, followed by a decrease in activity when the temperature was raised to pre-test levels, is suggestive of an avoidance response. The contrasting responses of the two species to thermal changes are consistent with their separate life history patterns and natural distributions. C1 Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. EM susan.sogard@hmsc.orst.edu NR 34 TC 9 Z9 9 U1 3 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD DEC PY 1998 VL 53 IS 4 BP 405 EP 412 DI 10.1023/A:1007485417486 PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 144KR UT WOS:000077314200007 ER PT J AU Able, KW Manderson, JP Studholme, AL AF Able, KW Manderson, JP Studholme, AL TI The distribution of shallow water juvenile fishes in an urban estuary: The effects of manmade structures in the lower Hudson river SO ESTUARIES LA English DT Article ID MOVEMENTS; TURBIDITY AB The objective of this study was to determine what effect, if any, large pile-supported platforms (piers) have on the habitat distribution and abundance of juvenile fishes. Trapping techniques were used in 1993 and 1994 under piers, in pile fields, and in open-water habitat types in shallow areas (<5 m) in the lower Hudson River estuary (40 degrees 44'N, 70 degrees 01'W). Nearly 1500 fishes, mostly juveniles, representing 24 species were collected in 1865 trap-days from May through October in the 2-yr study. The presence of relatively large numbers of young-of-the-year (YOY) fish during both years lends support to the idea that shallow areas in the lower Hudson River estuary currently function as nursery habitats for a variety of fishes. Two seasonal assemblages were apparent, but their composition varied somewhat between years. Microgadus tomcod and Pseudopleuronectes americanus YOY dominated an early summer assemblage (May-July) while large numbers of YOY Morone saxatilis were collected as part of a late summer assemblage (August-September). The effects of habitat type on fish assemblage structure were significant during both years. Fish abundance and species richness were typically low under piers; YOY fishes were rare and Anguilla rostrata accounted for a large proportion of the total catch. In contrast, YOY fishes dominated collections at pile field and open-water stations, where abundance and species richness were high. These results indicate that habitat quality under the platforms of large piers (>20,000 m(2)) is probably poor for YOY fishes when compared with nearby pile field and open-water habitat types. C1 Rutgers State Univ, Marine Field Stn, Inst Marine & Coastal Sci, Tuckerton, NJ 08087 USA. NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. RP Able, KW (reprint author), Rutgers State Univ, Marine Field Stn, Inst Marine & Coastal Sci, 800 Great Bay Blvd,132 Great Bay Blvd, Tuckerton, NJ 08087 USA. EM able@arctic.rutgers.edu NR 55 TC 44 Z9 44 U1 2 U2 11 PU ESTUARINE RESEARCH FEDERATION PI PORT REPUBLIC PA 2018 DAFFODIL, PO BOX 510, PORT REPUBLIC, MD 20676 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1998 VL 21 IS 4B BP 731 EP 744 DI 10.2307/1353277 PG 14 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 169KE UT WOS:000078746300007 ER PT J AU Ross, RJ Gaffen, DJ AF Ross, RJ Gaffen, DJ TI Comment on "Widespread tropical atmospheric drying from 1979 to 1995" by Schroeder and McGuirk SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material ID TROPOSPHERIC WATER-VAPOR; TEMPERATURE; MOISTURE C1 NOAA, Air Resources Lab, REAR, Silver Spring, MD 20910 USA. RP Gaffen, DJ (reprint author), NOAA, Air Resources Lab, REAR, 1315 E W Hwy, Silver Spring, MD 20910 USA. NR 12 TC 17 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1998 VL 25 IS 23 BP 4357 EP 4358 DI 10.1029/1998GL900169 PG 2 WC Geosciences, Multidisciplinary SC Geology GA 143XG UT WOS:000077282400030 ER PT J AU Wood, EF Lettenmaier, DP Liang, X Lohmann, D Boone, A Chang, S Chen, F Dai, YJ Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchel, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC AF Wood, EF Lettenmaier, DP Liang, X Lohmann, D Boone, A Chang, S Chen, F Dai, YJ Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchel, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC TI The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment: 1. Experiment description and summary intercomparisons SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT Project for Intercomparison of Landsurface Parameterization Schemes Workshop (PILPS) CY JUN, 1997 CL MELBOURNE, AUSTRALIA DE PILPS; land-surface parameterization; continental river basin modeling; energy/water balance; calibration of land-surface schemes; Red-Arkansas River basin AB 0Sixteen land-surface schemes participating in the Project for the Intercomparison of Land-surface Schemes (PILPS) Phase 2(c) were run using 10 years (1979-1988) of forcing data for the Red-Arkansas River basins in the Southern Great Plains region of the United States. Forcing data (precipitation, incoming radiation and surface meteorology) and land-surface characteristics (soil and vegetation parameters) were provided to each of the participating schemes. Two groups of runs are presented. (1) Calibration-validation runs, using data from six small catchments distributed across the modeling domain. These runs were designed to test the ability of the schemes to transfer information about model parameters to other catchments and to the computational grid boxes. (2) Base-runs, using data for 1979-1988, designed to evaluate the ability of the schemes to reproduce measured energy and water fluxes over multiple seasonal cycles across a climatically diverse, continental-scale basin. All schemes completed the base-runs but five schemes chose not to calibrate. Observational data (from 1980-1986) including daily river flows and monthly basin total evaporation estimated through an atmospheric budget analysis, were used to evaluate model performance. In general, the results are consistent with earlier PILPS experiments in terms of differences among models in predicted water and energy fluxes. The mean annual net radiation varied between 80 and 105 W m(-2) (excluding one model). The mean annual Bowen ratio varied from 0.52 to 1.73 (also excluding one model) as compared to the data-estimated value of 0.92. The run-off ratios varied from a low of 0.02 to a high of 0.41, as compared to an observed value of 0.15. In general, those schemes that did not calibrate performed worse, not only on the validation catchments, but also at the scale of the entire modeling domain. This suggests that further PILPS experiments on the value of calibration need to be carried out. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. Univ Washington, Dept Civil Engn, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Mesoscale Dynam & Precipitat Branch, Greenbelt, MD 20771 USA. USAF, Res Lab, Hanscom AFB, MA USA. NOAA, NCEP, Environm Modeling Ctr, Camp Springs, MD USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. Univ Arizona, Inst Atmospher Phys, Tucson, AZ USA. NOAA, Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. Oregon State Univ, Corvallis, OR 97331 USA. Russian Acad Sci, Inst Water Problems, Moscow, Russia. Meteo France, CNRM, Toulouse, France. Univ New S Wales, Ctr Adv Numer Computat Engn & Sci, Sydney, NSW 2052, Australia. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. NOAA, GFDL, Princeton, NJ USA. Russian Acad Sci, Inst Geog, Moscow, Russia. Climate Res Branch, Atmospher Environm Serv, Toronto, ON, Canada. GKSS Forschungszentrum Geesthacht GmbH, Res Ctr, D-2054 Geesthacht, Germany. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. RP Wood, EF (reprint author), Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. RI Dai, Yongjiu/D-1070-2010; Yang, Zong-Liang/B-4916-2011; Koster, Randal/F-5881-2012; Chen, Fei/B-1747-2009; lettenmaier, dennis/F-8780-2011; Nasonova, Olga/B-6093-2014; Duan, Qingyun/C-7652-2011; gusev, yugeniy/G-4711-2014; Shao, Yaping/G-3606-2013; Dai, Yongjiu/D-6261-2014; OI Habets, Florence/0000-0003-1950-0921; Koster, Randal/0000-0001-6418-6383; lettenmaier, dennis/0000-0003-3317-1327; Duan, Qingyun/0000-0001-9955-1512; gusev, yugeniy/0000-0003-3886-2143; Shao, Yaping/0000-0002-2041-5479; Dai, Yongjiu/0000-0002-3588-6644; Wood, Eric/0000-0001-7037-9675 NR 17 TC 208 Z9 228 U1 1 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 EI 1872-6364 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1998 VL 19 IS 1-4 BP 115 EP 135 DI 10.1016/S0921-8181(98)00044-7 PG 21 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 139GF UT WOS:000077019100008 ER PT J AU Liang, X Wood, EF Lettenmaier, DP Lohmann, D Boone, A Chang, S Chen, F Dai, YJ Desborough, C Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchell, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC AF Liang, X Wood, EF Lettenmaier, DP Lohmann, D Boone, A Chang, S Chen, F Dai, YJ Desborough, C Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchell, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC TI The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment: 2. Spatial and temporal analysis of energy fluxes SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT Project for Intercomparison of Landsurface Parameterization Schemes Workshop (PILPS) CY JUN, 1997 CL MELBOURNE, AUSTRALIA DE PILPS; energy balance; land-surface models; Red-Arkansas River basin ID SOIL HEAT-FLUX; MODEL AB The energy components of sixteen Soil-Vegetation Atmospheric Transfer (SVAT) schemes were analyzed and intercompared using 10 years of surface meteorological and radiative forcing data from the Red-Arkansas River basin in the Southern Great Plains of the United States. Comparisons of simulated surface energy fluxes among models showed that the net radiation and surface temperature generally had the best agreement among the schemes. On an average (annual and monthly) basis, the estimated latent heat fluxes agreed (to within approximate estimation errors) with the latent heat fluxes derived from a radiosonde-based atmospheric budget method for slightly more than half of the schemes. The sensible heat fluxes had larger differences among the schemes than did the latent heat fluxes, and the model-simulated ground heat fluxes had large variations among the schemes. The spatial patterns of the model-computed net radiation and surface temperature were generally similar among the schemes, and appear reasonable and consistent with observations of related variables, such as surface air temperature. The spatial mean patterns of latent and sensible heat fluxes were less similar than for net radiation, and the spatial patterns of the ground heat flux vary greatly among the 16 schemes. Generally, there is less similarity among the models in the temporal (interannual) variability of surface fluxes and temperature than there is in the mean fields, even for schemes with similar mean fields. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. Univ Washington, Dept Civil Engn, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Mesoscale Dynam & Precipitat Branch, Greenbelt, MD 20771 USA. USAF, Res Lab, Hanscom, MA USA. NOAA, NCEP, Environm Modeling Ctr, Camp Springs, MD USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. Macquarie Univ, Climat Impacts Ctr, Sydney, NSW 2109, Australia. Univ Arizona, Inst Atmospher Phys, Tucson, AZ USA. NOAA, Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. Oregon State Univ, Corvallis, OR 97331 USA. Russian Acad Sci, Inst Water Problems, Moscow, Russia. Meteo France, CNRM, Toulouse, France. Univ New S Wales, Ctr Adv Numer Computat Eng & Sci, Sydney, NSW 2052, Australia. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. NOAA, GFDL, Princeton, NJ USA. Russian Acad Sci, Inst Geog, Moscow, Russia. Climate Res Branch, Atmospher Environm Serv, Toronto, ON, Canada. RP Liang, X (reprint author), Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. RI Nasonova, Olga/B-6093-2014; Duan, Qingyun/C-7652-2011; gusev, yugeniy/G-4711-2014; Shao, Yaping/G-3606-2013; Dai, Yongjiu/D-6261-2014; Dai, Yongjiu/D-1070-2010; Yang, Zong-Liang/B-4916-2011; Koster, Randal/F-5881-2012; Chen, Fei/B-1747-2009; lettenmaier, dennis/F-8780-2011 OI Wood, Eric/0000-0001-7037-9675; Duan, Qingyun/0000-0001-9955-1512; gusev, yugeniy/0000-0003-3886-2143; Shao, Yaping/0000-0002-2041-5479; Dai, Yongjiu/0000-0002-3588-6644; Habets, Florence/0000-0003-1950-0921; Koster, Randal/0000-0001-6418-6383; lettenmaier, dennis/0000-0003-3317-1327 NR 13 TC 73 Z9 82 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1998 VL 19 IS 1-4 BP 137 EP 159 DI 10.1016/S0921-8181(98)00045-9 PG 23 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 139GF UT WOS:000077019100009 ER PT J AU Lohmann, D Lettenmaier, DP Liang, X Wood, EF Boone, A Chang, S Chen, F Dai, YJ Desborough, C Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchell, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC AF Lohmann, D Lettenmaier, DP Liang, X Wood, EF Boone, A Chang, S Chen, F Dai, YJ Desborough, C Dickinson, RE Duan, QY Ek, M Gusev, YM Habets, F Irannejad, P Koster, R Mitchell, KE Nasonova, ON Noilhan, J Schaake, J Schlosser, A Shao, YP Shmakin, AB Verseghy, D Warrach, K Wetzel, P Xue, YK Yang, ZL Zeng, QC TI The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment: 3. Spatial and temporal analysis of water fluxes SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT Project for Intercomparison of Landsurface Parameterization Schemes Workshop (PILPS) CY JUN, 1997 CL MELBOURNE, AUSTRALIA DE PILPS; water balance; routing model; continental river basin modeling; Red-Arkansas River basin ID MODELS AB The water-balance components of 16 Soil-Vegetation Atmospheric Transfer (SVAT) schemes were evaluated by comparing predicted and observed streamflow, predicted evapotranspiration and evapotranspiration inferred from an atmospheric moisture budget analysis, and soil moisture storage changes for a seven-year period (1980-1986) using data from the Red-Arkansas River basins of the Southern Great Plains of the USA. The evaluations support the following suggestions: (a) The mean annual runoff of all models follows, at least generally, the strong climatic East-West gradient of precipitation, although most models predict too much runoff in the dry part of the basin. (b) The mean monthly storage change tends to be underestimated, even though all models capture reasonably well the seasonality of the evapotranspiration. (c) The wide range of conceptualizations used for generation of surface and subsurface runoff strongly affect runoff generation on seasonal, and shorter, time scales. Model responses to summer precipitation ranged from almost no summer runoff tone model) to the (more common) situation of persistent overprediction of summer runoff, especially in the driest part of the basin. (d) All models tended to underpredict evapotranspiration in summer and overpredict in winter. (e) Model-derived mean seasonal cycles of changes in soil moisture storage are qualitatively similar to those inferred from observations, but most models do not predict the decrease in April soil moisture storage and the increase in October that is inferred from observations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. Univ Washington, Dept Civil Engn, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Mesoscale Dynam & Precipitat Branch, Greenbelt, MD 20771 USA. USAF, Res Lab, Hanscom AFB, MA USA. NOAA, NCEP, Environm Modeling Ctr, Camp Springs, MD USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. Macquarie Univ, Climat Impacts Ctr, Sydney, NSW 2109, Australia. Univ Arizona, Inst Atmospher Phys, Tucson, AZ USA. NOAA, Natl Weather Serv, Off Hydrol, Silver Spring, MD 20910 USA. Oregon State Univ, Corvallis, OR 97331 USA. Russian Acad Sci, Inst Water Problems, Moscow, Russia. Meteo France, CNRM, Toulouse, France. Univ New S Wales, Ctr Adv Numer Computat Engn & Sci, Sydney, NSW 2052, Australia. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. NOAA, GFDL, Princeton, NJ USA. Russian Acad Sci, Inst Geog, Moscow, Russia. Climate Res Branch, Atmospher Environm Serv, Toronto, ON, Canada. GKSS Forschungszentrum Geesthacht GmbH, Res Ctr, D-2054 Geesthacht, Germany. Ctr Ocean Land Atmospher Studies, Calverton, MD USA. RP Lohmann, D (reprint author), Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. RI Dai, Yongjiu/D-1070-2010; Yang, Zong-Liang/B-4916-2011; Koster, Randal/F-5881-2012; Chen, Fei/B-1747-2009; lettenmaier, dennis/F-8780-2011; Nasonova, Olga/B-6093-2014; Duan, Qingyun/C-7652-2011; gusev, yugeniy/G-4711-2014; Shao, Yaping/G-3606-2013; Dai, Yongjiu/D-6261-2014; OI Koster, Randal/0000-0001-6418-6383; lettenmaier, dennis/0000-0003-3317-1327; Duan, Qingyun/0000-0001-9955-1512; gusev, yugeniy/0000-0003-3886-2143; Shao, Yaping/0000-0002-2041-5479; Dai, Yongjiu/0000-0002-3588-6644; Habets, Florence/0000-0003-1950-0921; Wood, Eric/0000-0001-7037-9675 NR 25 TC 135 Z9 144 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 EI 1872-6364 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1998 VL 19 IS 1-4 BP 161 EP 179 DI 10.1016/S0921-8181(98)00046-0 PG 19 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 139GF UT WOS:000077019100010 ER PT J AU Paulter, NG AF Paulter, NG TI Long-term repeatability of a TDR-based printed wiring board dielectric constant measurement system SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE dielectric constant; high-speed/high-frequency; measurement repeatability; printed wiring board; time-domain reflectometry AB A new time-domain-reflectometry-based method has been recently developed that provides accurate determinations of the dielectric constant of printed wiring board dielectrics over the frequency range of 0.1 GHz to 10 GHz. The longterm measurement reproducibility, as well as the short-term measurement repeatability, of that method were investigated and the results are reported here. C1 US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Elect Div,Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Paulter, NG (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Technol Adm, Elect Div,Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. NR 2 TC 18 Z9 19 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 1998 VL 47 IS 6 BP 1469 EP 1473 DI 10.1109/19.746713 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 167NU UT WOS:000078640800011 ER PT J AU Dunleavy, LP Randa, J Walker, DK Billinger, R Rice, J AF Dunleavy, LP Randa, J Walker, DK Billinger, R Rice, J TI Characterization and applications of on-wafer diode noise sources SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT 1998 International Microwave Symposium / Radio Frequency Integrated Circuits Symposium / Automatic-RF-Techniques-Group Meeting CY 1998 CL BALTIMORE, MARYLAND SP Automat RF Tech Grp DE noise; noise characterization; noise measurement; noise source; noise temperature; on-wafer noise measurement AB A set of wafer-probeable diode noise source transfer standards are characterized using on-wafer noise-temperature methods developed at the National Institute of Standards and Technology (NIST), Boulder, CO. We review the methods for accurate measurement and prediction of on-wafer noise temperature of off-wafer and on-wafer noise source standards. In analog!, with the excess noise ratio (ENR) for hot noise temperatures, we introduce a representation for cold noise temperatures called the cold noise ratio (CNR), which is expressed in decibels, The ENR and CNR noise source representations share the property that the difference between off-wafer and on-wafer values may he approximated by the probe loss. We present measurements of the on-wafer ENR and reflection-coefficient information for a preliminary set of on-wafer diode transfer standards at frequencies from 8 to 12 GHz. Such transfer standards could be used in interlaboratory comparisons, as a noise calibration verification tool, as direct calibration artifacts, or as the basis for a new "noise-source probe" conceptualized here. C1 Univ S Florida, Dept Elect Engn, Tampa, FL 33620 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Dunleavy, LP (reprint author), Univ S Florida, Dept Elect Engn, Tampa, FL 33620 USA. NR 16 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 1998 VL 46 IS 12 BP 2620 EP 2628 DI 10.1109/22.739255 PN 2 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 158CT UT WOS:000078099000058 ER PT J AU Abdulagatov, IM Magomedov, UB AF Abdulagatov, IM Magomedov, UB TI Thermal conductivity of aqueous ZnCl2 solutions at high temperatures and high pressures SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID 100 MPA; 473 K AB The thermal conductivity of H2O + ZnCl2 solutions was measured over the temperature range 293-473 K using a parallel-plate apparatus. Data cover the pressure range from 0.1 to 100 MPa. Measurements were made on six isobars, namely, 0.1, 20, 40, 60, 80, and 100 MPa. The concentrations studied were 2.5, 5, 10, 15, 20, and 25 wt % ZnCl2. The accuracy of the measurements was estimated to be +/-1.6%. The effect of temperature, pressure, and concentration on the thermal conductivity behavior was studied. The thermal conductivity shows a linear dependence on pressure and concentration at all isotherms for each concentration. Along each isobar a given concentration shows the thermal-conductivity maximum at temperatures between 405 and 417 K. The measured values of thermal conductivity are compared with the experimental and correlation results of other investigators. Our experimental results for the H2O + ZnCl2 system confirm the results obtained by DiGuilio et al. (DiGuilio, R. M.; et al. ASHRAE Traits. 1990, 96, 702; DiGuilio, R. M.; Teja, A. S. Ind. Eng. Chem. Res. 1992, 31, 1081) and Bleazard et al. (Bleazard, J. G.; et al. AIChE Symp. Ser. 1994, 298, 23; Bleazard, J. G.; Teja, A/ S. J. Chem. Eng. Data 1995, 40, 732). The constant-composition curves are not parallel to those for pure water at high pressures and high concentrations. A new correlation which yields the correct temperature, pressure, and concentration behavior of thermal conductivity is proposed. The pressure and temperature coefficients of the thermal conductivity have been studied. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Res, Makhachkala 367030, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 14 Z9 14 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD DEC PY 1998 VL 37 IS 12 BP 4883 EP 4888 DI 10.1021/ie9803772 PG 6 WC Engineering, Chemical SC Engineering GA 146NH UT WOS:000077436600046 ER PT J AU Paranjpye, RN Lara, JC Pepe, JC Pepe, CM Strom, MS AF Paranjpye, RN Lara, JC Pepe, JC Pepe, CM Strom, MS TI The type IV leader peptidase/N-methyltransferase of Vibrio vulnificus controls factors required for adherence to HEp-2 cells and virulence in iron-overloaded mice SO INFECTION AND IMMUNITY LA English DT Article ID GENERAL SECRETORY PATHWAY; GRAM-NEGATIVE BACTERIA; PSEUDOMONAS-AERUGINOSA PILI; FIELD GEL-ELECTROPHORESIS; AEROMONAS-HYDROPHILA; ESCHERICHIA-COLI; EXTRACELLULAR CYTOLYSIN; N-METHYLTRANSFERASE; PROTEIN SECRETION; HEMOLYSIN GENE AB Vibrio vulnificus expresses a number of potential virulence determinants that may contribute to its ability to cause a severe and rapidly disseminating septicemia in susceptible hosts. We have cloned and characterized two genes encoding products related to components of the type IV pilus biogenesis and general secretory (type II) pathways by complementation of a type IV peptidase/N-methyltransferase (PilD) mutant of Pseudomonas aeruginosa Nifh a V. vulnificus genomic library. One of the genes (vvpD) encodes a protein homologous to PilD and other members of the type IV peptidase family that completely restores this activity in a P. aeruginosa mutant deficient in the expression of PilD. The other gene (vvpC) encodes a homolog of PilC from P. aeruginosa, where it is essential for assembly of type IV pill. Phenotypic characterization of a V. vulnificus vvpD mutant, constructed by allelic exchange, showed that VvpD is required for the expression of surface pill, suggesting that the pill observed on V. vulnificus are of the type IV class. This mutant was also unable to secrete at least three extracellular degradative enzymes, and the localization of one of these (the cytolysin/hemolysin) to the periplasmic space indicates that these proteins are normally exported via the type II secretion pathway. Loss of VvpD resulted in significant decreases in CHO cell cytotoxicity, adherence to HEp-2 cells, and virulence in a mouse model. Capsule formation and serum resistance were not affected in the vvpD mutant, indicating that in addition to capsule, virulence of V. vulnificus requires type IV pill and/or extracellular secretion of several exoenzymes. C1 Univ Washington, Sch Med, Dept Microbiol, Seattle, WA 98195 USA. US Dept Commerce, NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA USA. RP Strom, MS (reprint author), 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM mark.strom@noaa.gov NR 71 TC 79 Z9 80 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD DEC PY 1998 VL 66 IS 12 BP 5659 EP 5668 PG 10 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 142BG UT WOS:000077179600009 PM 9826339 ER PT J AU Curtis, J Wendler, G Stone, R Dutton, E AF Curtis, J Wendler, G Stone, R Dutton, E TI Precipitation decrease in the western arctic, with special emphasis on Barrow and Barter Island, Alaska SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE Alaska; western Arctic; climatic trend analyses; cloud cover; temperature; precipitation ID AIR-TEMPERATURE; CLIMATE; DATE AB Over the Arctic during the last few decades a decrease in annual precipitation and snow depths have been observed; this decrease is especially pronounced during the winter months. This decrease was not only found over northern Alaska but also over the high latitude Canadian stations and Russian drift stations. Further, satellite monitoring of North America snow cover has revealed a significant decreasing trend in mid-spring cover since 1972. The temperature increased during the last few decades in the Arctic, hence the simplest explanation-normally increased temperature leads to high precipitation-is not valid. A causal explanation for these trends had been related to the shift of the Aleutian low and Arctic high. This study, with special emphasis on the surface observation data from Barrow and Barter Island, indicates: (i) not only the frequency, but the mean intensity of precipitation has decreased; (ii) the amount of total cloud cover, and in particular, low cloudiness, has decreased with time; (iii) sea-level pressure did not show any significant trends. Variability in atmospheric pressure, however, decreased with time, suggesting that either the intensity and/or frequency of cyclones has decreased; (iv) a shift in seasonal resultant winds at Barrow has been observed. (C) 1998 Royal Meteorological Society. C1 Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Curtis, J (reprint author), Univ Alaska, Inst Geophys, POB 757352, Fairbanks, AK 99775 USA. EM jcurtis@gi.alaska.edu NR 28 TC 37 Z9 37 U1 1 U2 9 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 DEC PY 1998 VL 18 IS 15 BP 1687 EP 1707 DI 10.1002/(SICI)1097-0088(199812)18:15<1687::AID-JOC341>3.0.CO;2-2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 148YU UT WOS:000077562800004 ER PT J AU Widmann, JF Davis, EJ AF Widmann, JF Davis, EJ TI Pulsed electromagnetic heating of microparticles SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID ELECTRODYNAMIC THERMOGRAVIMETRIC ANALYZER; SINGLE PARTICLES; KINETICS; BALANCE AB The application of pulsed heating by a laser beam to determine the thermal properties of microparticles is explored. Two problems are analyzed: (i) spatially uniform heating of the surface of an absorbing microsphere, and (ii) nonuniform surface heating based on Mie theory computations of the electromagnetic energy source. A parametric study shows that the spatially uniform heating model is sufficient when the thermal conductivity of the microparticle is sufficiently large or the Biot number is sufficiently low, but a more rigorous model is needed to predict the temperature distribution with the microsphere for lower thermal conductivity materials. The resulting analytical solutions are compared with previously published experiments involving infrared heating of single spherocarb particles and are shown to be in good agreement with time-dependent surface temperature measurements. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. RP Davis, EJ (reprint author), Natl Inst Stand & Technol, High Temp Proc Grp, Bldg 221,Rm B312, Gaithersburg, MD 20899 USA. NR 13 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD DEC PY 1998 VL 41 IS 24 BP 4195 EP 4204 DI 10.1016/S0017-9310(98)00126-4 PG 10 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 142FH UT WOS:000077189000012 ER PT J AU Telles, EM Zink, LR Evenson, KM AF Telles, EM Zink, LR Evenson, KM TI New FIR laser lines from CD3OH SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE far-infrared; methanol; CD3OH; optically-pumped laser; laser ID METHANOL; 9-MU-M AB Fourteen new optically pumped far-infrared (FIR) laser lines in the range 46.8 mu m to 172.6 mu m were discovered in optically pumped CD3OH. The pump sources include both the CO2 laser and the N2O laser. Two theoretically predicted laser lines were observed in this study. C1 Natl Inst Stand & Technol, Time & Frequency Div, Boulder, CO 80303 USA. RP Telles, EM (reprint author), Natl Inst Stand & Technol, Time & Frequency Div, 325 Broadway, Boulder, CO 80303 USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD DEC PY 1998 VL 19 IS 12 BP 1627 EP 1631 DI 10.1023/A:1021758925265 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 147PK UT WOS:000077575500002 ER PT J AU Vahala, G Pavlo, P Vahala, L Martys, NS AF Vahala, G Pavlo, P Vahala, L Martys, NS TI Thermal lattice-Boltzmann models (TLBM) for compressible flows SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article; Proceedings Paper CT 7th International Conference on the Discrete Simulation of Fluids CY JUL 14-18, 1998 CL UNIV OXFORD, OXFORD, ENGLAND HO UNIV OXFORD DE lattice symmetries; linear stability; Rayleigh-Bernard AB The progress and challenges in thermal lattice-Boltzmann modeling are discussed. In particular, momentum and energy closures schemes are contrasted. Higher order symmetric (but no longer space filling) velocity lattices are constructed for both 2D and 3D flows and shown to have superior stability properties to the standard (but lower) symmetry lattices. While this decouples the velocity lattice from the spatial grid, the interpolation required following free-streaming is just 1D. The connection between fixed lattice vectors and temperature-dependent lattice vectors (obtained in the Gauss-Hermite quadrature approach) is discussed. Some (compressible) Rayleigh-Benard simulations on the 2D octagonal lattice are presented for extended BGK collision operators that allow for arbitrary Prandtl numbers. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. Acad Sci Czech Republ, Inst Plasma Phys, Prague 8, Czech Republic. Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. NIST, Gaithersburg, MD 20899 USA. RP Vahala, G (reprint author), Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RI Pavlo, Pavol/G-4214-2014 OI Pavlo, Pavol/0000-0003-1400-1074 NR 14 TC 36 Z9 37 U1 1 U2 8 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD DEC PY 1998 VL 9 IS 8 BP 1247 EP 1261 DI 10.1142/S0129183198001126 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 199BL UT WOS:000080459500010 ER PT J AU Bruno, TJ Bachmeyer, GM Wertz, KH AF Bruno, TJ Bachmeyer, GM Wertz, KH TI Gas chromatographic retention parameters database for refrigerant mixture composition management SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigerant; zeotropic mixtures; chemical composition; chromatography ID GRAPHITIZED CARBON-BLACK; ETHENE-BASED COMPOUNDS; LIQUID-CHROMATOGRAPHY; INDEX SYSTEM; HALOCARBONS AB Composition management of mixed refrigerant systems is a challenging problem in the laboratory, manufacturing facilities, and large refrigeration machinery. The issue of composition management is especially critical for the maintenance of machinery that utilizes zeotropic mixtures as working fluids. These are fluids in which the gas and liquid phases will generally have greatly different compositions. While there are many analytical techniques available for laboratory and on-line analyses, gas chromatography probably offers the greatest flexibility at the most reasonable cost. This paper describes a chromatographic database that provides for the identification of refrigerant components, and thereby facilitates composition management of zeotropic fluids. Prior to the description of the database is a description of the basic theory of chromatographic retention parameters and a description of the experimental techniques used in their measurement. (C) 1998 Elsevier Science Ltd and IIR. All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 21 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD DEC PY 1998 VL 21 IS 8 BP 639 EP 647 DI 10.1016/S0140-7007(98)00025-5 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 145BY UT WOS:000077352200006 ER PT J AU Kogan, FN AF Kogan, FN TI A typical pattern of vegetation conditions in southern Africa during El Nino years detected from AVHRR data using three-channel numerical index. SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID SEA-SURFACE TEMPERATURE; UNITED-STATES; AREAS AB The 1997-98 FEl Nino is one of the strongest events of the last 50 years. Its absolute magnitude, areal extent, and rapid development have raised a serious concern among decision makers because of its possible impact on global ecosystems. In this study, El Nino consequences for land ecosystem were examined using the new AVHRR-based three-channel index (VT), widely used for monitoring drought around the world. The VT index was used to identify a typical pattern of vegetation conditions in southern Africa during the recent El Nino years. Features and trends of the 1997-98 El Nino including its intensity, extent, and impact on vegetation are also discussed. C1 NOAA, Ctr Sci, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. RP Kogan, FN (reprint author), NOAA, Ctr Sci, Natl Environm Satellite Data & Informat Serv, Room 712,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Kogan, Felix/F-5600-2010 OI Kogan, Felix/0000-0001-8216-900X NR 15 TC 19 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 DEC PY 1998 VL 19 IS 18 BP 3689 EP 3695 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 152JU UT WOS:000077774800014 ER PT J AU Weil, CM Geyer, RG Sengupta, L AF Weil, CM Geyer, RG Sengupta, L TI Microwave dielectric characterization of bulk ferroelectrics SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 2nd European Meeting on Integrated Ferroelectrics (EMIF2) CY SEP 28-30, 1997 CL JOUY EN JOSAS, FRANCE SP Siemens, Thomson-CSF AB We discuss the application of existing RF measurement techniques, including waveguide and mode-filtered cavity resonator methods, to the dielectric characterization of bulk high-permittivity ferroelectrics at microwave frequencies. Complex permittivity data are presented for barium titanate and a composite of barium strontium titanate (BSTO) and nonferroelectric oxide at X-band (8-11 GHz) frequencies and at 24 degrees C temperature. The advantages and disadvantages of each method are discussed in detail. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. USA, Res Lab, Aberdeen Proving Ground, MD 21005 USA. RP Weil, CM (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 1998 VL 8 IS P9 BP 113 EP 116 DI 10.1051/jp4:1998919 PG 4 WC Physics, Multidisciplinary SC Physics GA 158LZ UT WOS:000078118100020 ER PT J AU Meszaros, E Molnar, A Ogren, J AF Meszaros, E Molnar, A Ogren, J TI Scattering and absorption coefficients vs. chemical composition of fine atmospheric aerosol particles under regional conditions in Hungary SO JOURNAL OF AEROSOL SCIENCE LA English DT Article ID SPECTRAL EXTINCTION COEFFICIENTS; ANTHROPOGENIC AEROSOLS; CLIMATE; SULFUR AB The light scattering and absorption coefficients of aerosol particles with a dry diameter below 1 mu m were recorded in the country air of Hungary. Concentrations of different inorganic and organic ions were measured in parallel to estimate the nature of particles causing light scattering. The sample air was heated gently to maintain a relative humidity of 30% and coarse particles were removed by a multi-jet impactor. The aerosol light scattering coefficient was monitored with an integrating nephelometer, while absorption was measured on the basis of the rate of blackening of a filter. Results gained during two time periods, mostly in the winter months, are presented in this paper. Data show that the winter average light scattering coefficient is 93 Mm(-1), while the corresponding figure for light absorption is 8.9 Mm(-1). This results in a single-scatter albedo of 0.91. Comparison of the optical data with chemical information indicates that there is a good correlation between light scattering coefficient and sulfate concentration. The relationship is significant, in particular, in the winter half-year. Regression calculations among the measured parameters suggest for summer and winter half-year a sulfate mass scattering efficiency of 6 and 8 m(2) g(-1), respectively. By using a mass absorption efficiency of 10 m(2)g(-1), the average winter absorption coefficient corresponds to an elemental carbon concentration of 0.9 mu g m(-3). (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Veszprem, Dept Earth & Environm Sci, H-8201 Veszprem, Hungary. Hungarian Acad Sci, Air Chem Grp, H-8201 Veszprem, Hungary. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Meszaros, E (reprint author), Univ Veszprem, Dept Earth & Environm Sci, POB 158, H-8201 Veszprem, Hungary. RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 21 TC 23 Z9 25 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD DEC PY 1998 VL 29 IS 10 BP 1171 EP 1178 DI 10.1016/S0021-8502(98)00027-5 PG 8 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 130JN UT WOS:000076517100001 ER PT J AU Mildner, DFR Lamaze, GP AF Mildner, DFR Lamaze, GP TI Neutron transmission of single-crystal sapphire SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID FILTERS AB Thermal and cold neutron transmission time-of-flight measurements have been taken on blocks of single-crystal sapphire. The transmission characteristics of single-crystal sapphire are not altered by irradiation for a number of years within a beam port at a reactor. Cooling the filter is only useful for the production of beams with the longest wavelengths. Even for poorer grade sapphire there is no degradation of the neutron transmission characteristics. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Mildner, DFR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 19 Z9 19 U1 1 U2 2 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 1998 VL 31 BP 835 EP 840 DI 10.1107/S0021889898005846 PN 6 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 157ND UT WOS:000078067800003 ER PT J AU Thiyagarajan, P Crawford, RK Mildner, DFR AF Thiyagarajan, P Crawford, RK Mildner, DFR TI Neutron transmission of a single-crystal MgO filter SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB The neutron transmission probability through a single-crystal MgO filter has been measured at both liquid-nitrogen (77 K) and room (300 K) temperatures, as a function of wavelength, using a pulsed neutron source. The data show that a cooled MgO filter is superior to room-temperature sapphire for both thermal and cold neutrons, principally because the absorption probability is reduced by a factor of three at long wavelengths. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Mildner, DFR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 13 Z9 13 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 1998 VL 31 BP 841 EP 844 DI 10.1107/S0021889898005858 PN 6 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 157ND UT WOS:000078067800004 ER PT J AU Gnaupel-Herold, T Brand, PC Prask, HJ AF Gnaupel-Herold, T Brand, PC Prask, HJ TI Calculation of single-crystal elastic constants for cubic crystal symmetry from powder diffraction data SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID RESIDUAL-STRESSES; POLYCRYSTAL AB In this work a method is developed that allows the computation of the single-crystal elastic constants for crystals of cubic symmetry from the diffraction elastic constants. The diffraction elastic constants can be obtained by measuring the hkl-dependent lattice strain response to an applied stress. Because of their hkl dependence they represent, partially, the anisotropic nature of the single-crystal elastic constants. The computation of the single-crystal elastic constants is carried out by a least-squares refinement which fits the calculated diffraction elastic constants to the measured ones. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Gnaupel-Herold, T (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. OI Gnaupel-Herold, Thomas/0000-0002-8287-5091 NR 27 TC 47 Z9 47 U1 0 U2 17 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 1998 VL 31 BP 929 EP 935 DI 10.1107/S002188989800898X PN 6 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 157ND UT WOS:000078067800016 ER PT J AU Fairall, CW Persson, POG Bradley, EF Payne, RE Anderson, SP AF Fairall, CW Persson, POG Bradley, EF Payne, RE Anderson, SP TI A new look at calibration and use of Eppley precision infrared radiometers. Part I: Theory and application SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PYRGEOMETER PERFORMANCE; RADIATION; LONGWAVE AB The calibration and accuracy of the Eppley precision infrared radiometer (PIR) is examined both theoretically and experimentally. A rederivation of the fundamental energy balance of the PIR indicates that the calibration equation in common use in the geophysical community today contains an erroneous factor of the emissivity of the thermopile. If a realistic value (0.98) for the emissivity is' used, then this leads to errors in the total flux of 5-10 W m(-2). The basic precision of the instrument is found to be about 1.5% of the total IR irradiance when the thermopile voltage and both dome and case temperatures are measured. If the manufacturer's optional battery-compensated output is used exclusively, then the uncertainties increase to about 1.5% of the total (20 W m(-2)). It is suggested that a modern radiative transfer model combined with radiosonde profiles can be used as a secondary standard to improve the absolute accuracy of PIR data from field programs. Downwelling IR fluxes calculated using the Rapid Radiative Transfer Model (RRTM), from 55 radiosondes ascents in cloud-free conditions during the Tropical Oceans Global Atmosphere Coupled Ocean-Atmosphere Response Experiment field program, gave mean agreement within 2 W m(-2) of those measured with a shipborne PIR. PIR data from two sets of instrument intercomparisons were used to demonstrate ways of detecting inconsistencies in thermopile-sensitivity coefficients and dome-heating correction coefficients. These comparisons indicated that pairs of PIRs are easily corrected to yield mean differences of 1 W m(-2) and rms differences of 2 W m(-2). Data from a previous field program over the ocean indicate that pairs of PIRs can be used to deduce the true surface skin temperature to an accuracy of a few tenths of a kelvin. C1 NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80309 USA. CSIRO, Ctr Environm Mech, Canberra, ACT 2601, Australia. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP Fairall, CW (reprint author), NOAA, ERL, Environm Technol Lab, 325 Broadway,R-E-ET7, Boulder, CO 80303 USA. RI Bradley, Frank/I-6574-2013 NR 30 TC 47 Z9 48 U1 0 U2 2 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 1998 VL 15 IS 6 BP 1229 EP 1242 DI 10.1175/1520-0426(1998)015<1229:ANLACA>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500001 ER PT J AU Rajopadhyaya, DK May, PT Cifelli, RC Avery, SK Willams, CR Ecklund, WL Gage, KS AF Rajopadhyaya, DK May, PT Cifelli, RC Avery, SK Willams, CR Ecklund, WL Gage, KS TI The effect of vertical air motions on rain rates and median volume diameter determined from combined UHF and VHF wind profiler measurements and comparisons with rain gauge measurements SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SIZE DISTRIBUTIONS; DOPPLER SPECTRA; RETRIEVAL AB Two different frequency radar wind profilers (920 and 50 MHz) were used to retrieve rain rates from a long-lasting rainfall event observed near Darwin, Northern Territory. Australia, during the 1993-94 wet season. In this technique, 50-MHz data are used to derive the vertical air motion parameters (vertical velocity and spectral width): the 920-MHz data are then used to obtain the precipitation characteristics with the vertical air motion corrections. A comparison of the retrieved rain rates with rain gauge measurements shows excellent agreement, A detailed examination of the mean vertical Velocity and spectral width corrections in the rain retrieval shows that the error due to an uncorrected mean vertical velocity can be as large as 100%, and the error for an uncorrected spectral width was about 10% for thr range of mean vertical velocity and spectral width considered. There was a strong functional dependence between the retrieved mean vertical velocity and percentage difference between observed and retrieved rain rates with and without vertical air motion corrections. The corresponding functional dependence with and without the spectral width corrections was small but significant. An uncorrected upward mean vertical velocity overestimates rain rates, whereas an uncorrected downward mean vertical velocity underestimates rain rates. Uncorrected spectral width estimates have a tendency to overestimate rain rates. There are additional errors in the width correction because of antenna beam mismatching. A mc thud is discussed to quantitatively evaluate this effect. and it is shown to be relatively small compared to the first-order mean vertical velocity correction. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Boulder, CO USA. RP Rajopadhyaya, DK (reprint author), Univ Colorado, CIRES, Campus Box 216, Boulder, CO 80309 USA. EM drajopad@numbat.colorado.edu RI Williams, Christopher/A-2723-2015 OI Williams, Christopher/0000-0001-9394-8850 NR 15 TC 39 Z9 41 U1 2 U2 3 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 1998 VL 15 IS 6 BP 1306 EP 1319 DI 10.1175/1520-0426(1998)015<1306:TEOVAM>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500007 ER PT J AU Ryzhkov, AV Zrnic, DS AF Ryzhkov, AV Zrnic, DS TI Polarimetric rainfall estimation in the presence of anomalous propagation SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID DIFFERENTIAL PHASE; RADAR AB Rainfall estimation from specific differential phases in meteorological situations with significant anomalous propagation (AP) is discussed. It is shown that the correlation coefficient between horizontally and vertically polarized backscatter signals and local variability of the total differential phase can be good identifiers of ground clutter-contaminated data. Further. it is suggested how to estimate rainfall in regions of ground clutter caused by AP. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Ryzhkov, AV (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 10 TC 53 Z9 55 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 DEC PY 1998 VL 15 IS 6 BP 1320 EP 1330 DI 10.1175/1520-0426(1998)015<1320:PREITP>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500008 ER PT J AU Grimsdell, AW Angevine, WM AF Grimsdell, AW Angevine, WM TI Convective boundary layer height measurement with wind profilers and comparison to cloud base SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ENTRAINMENT; SURFACE; ZONE; FLUX AB The depth of the atmospheric boundary layer is of interest in several different areas; such as chemistry, pollutant studies, and global modeling. In this research the authors describe and compare several different measurements of boundary layer depth. First. the authors use the standard measurement from radiosondes to confirm the validity of wind-profiler measurements, which use humidity gradients to estimate the boundary layer depth. A method for obtaining meaningful cloud-base altitudes is then presented, and the results are compared to the wind-profiler boundary layer heights. The authors find good agreement between the different types of measurement but see that the profiler peak reflectivity is slightly raised above cloud base in the presence of boundary layer clouds. This may be due to increased humidity gradients at the top and edges of clouds or to increased turbulence within the cloud. Calculation of the boundary layer height using the bulk Richardson number is commonly used in computer models. Comparison with the authors' profiler measurements indicates that the calculation overestimates the height of the boundary layer and that the agreement between the methods is poor. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Grimsdell, AW (reprint author), NOAA, Aeron Lab, R-E-AL3,325 Broadway, Boulder, CO 80303 USA. RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 16 TC 39 Z9 40 U1 0 U2 3 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 1998 VL 15 IS 6 BP 1331 EP 1338 DI 10.1175/1520-0426(1998)015<1331:CBLHMW>2.0.CO;2 PG 8 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500009 ER PT J AU Tai, CK AF Tai, CK TI On the spectral ranges that are resolved by a single satellite in exact-repeat sampling mode SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ALTIMETRIC SEA-LEVEL; TOPEX/POSEIDON DATA AB The sampling problem for satellite data in exact-repeat orbit configuration is treated in this paper. Specifically, for exact-repeat satellite sampling, the author seeks to solve the problem equivalent to finding the Nyquist frequency and wavenumbers for a textbook regular grid that frame a resolved spectral range within which all properly separated (assuming the data coverage is not infinite) spectral components can be distinguished (i.e., resolved) from each other, while an inside component is still indistinguishable from an infinite number of spectral components outside the range (i.e., aliasing). It is shown that there are multitudes of spectral ranges that are resolved with various degrees of uncertainty by the data: the suitable choice depends on the phenomena one wishes to observe and the noises one endeavors to avoid. The problem is idealized for applications to regions of limited latitudinal extent, so that straight lines represent satellite ground tracks well. Let X and Y be the east-west and north-south separations of parallel tracks, let T be the repeat period, and let k, l, and w be the nonangular wavenumbers and frequency with k in the east-west direction. The spectral range that is perfectly resolved las if the data were placed on a regular space-time grid) covers (-1/X, 1/X) in k, (-1/Y, 1/Y) in l, and [0, 1/2T) in w. There are other spectral ranges that extend either the spatial or temporal resolution with increased uncertainty beyond the above-mentioned perfectly resolved range. The idealized problem is solved in stages, progressing from the 1D, to the 2D, to the fully 3D problem. The process is aided by a discovery that has implications that go beyond the scope of this paper. II is found that from a multidimensional regular grid one is free to introduce misalignments to all dimensions except one without incurring any penalty in spectral resolution. That is, the misaligned grid is equivalent to a perfectly aligned grid in spectral resolution. (However, the misalignment does induce far more complicated aliasing.) Thus, nonsimultaneous observations are equivalent to simultaneous ones, hence reducing the 3D problem to the 2D one. One 2D grid (the crossover grid) is equivalent to not just one but two regular 2D grids. These results are all verified numerically. An analytic proof is provided for the equivalency theorem. C1 NOAA, Lab Satellite Altimetry, NODC, Silver Spring, MD 20910 USA. RP Tai, CK (reprint author), NOAA, Lab Satellite Altimetry, NODC, E-OC2,1315 EW Highway, Silver Spring, MD 20910 USA. RI Tai, C.K./F-5628-2010 NR 9 TC 9 Z9 9 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 DEC PY 1998 VL 15 IS 6 BP 1459 EP 1470 DI 10.1175/1520-0426(1998)015<1459:OTSRTA>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500017 ER PT J AU Halpern, D Ji, M Leetmaa, A Reynolds, RW AF Halpern, D Ji, M Leetmaa, A Reynolds, RW TI Influence of assimilation of subsurface temperature measurements on simulations of equatorial undercurrent and south equatorial current along the Pacific equator SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID GENERAL-CIRCULATION MODEL; TROPICAL PACIFIC; OCEAN MODEL; REDUCED-GRAVITY; WIND STRESS; VARIABILITY; CLIMATE; ERRORS AB Equatorial Pacific current and temperature fields were simulated with and without assimilation of subsurface temperature measurements for April 1992-March 1995 and compared with moored buoy and research vessel current measurements. Data assimilation intensified the mean east-west slope of the thermocline along the equator in the eastern Pacific, shifted eastward the longitude of the mean Equatorial Undercurrent (EUC) maximum speed 800 km to 125 degrees W, and produced a 25% stronger mean EUC core speed in the eastern Pacific. In the eastern Pacific the mean EUC core speed simulated with data assimilation was slightly more representative of observations compared to that computed without data assimilated; in the western Pacific the data assimilation had no impact on mean EUC simulations. Data assimilation intensified the north-south slope of the thermocline south of the equator in the western Pacific to produce a thicker and more intense westward-flowing South Equatorial Current (SEC) in the western Pacific. In the western Pacific the mean SEC transport per unit width simulated with data assimilation was more representative of observations compared to that computed without data assimilation. However, large differences remained between the observed SEC transport per unit width and that simulated with data assimilation. In the eastern Pacific, the data assimilation had no impact on mean SEC simulations. The temporal variability of monthly mean EUC core speeds and SEC transports per unit width were increased significantly by data assimilation. It also increased the representativeness of monthly mean SEC transports per unit width to the observations. However, the data representativeness of monthly mean EUC core speeds was decreased. Results could be explained by the coupling between zonal gradient of temperature and EUC and between meridional gradient of temperature and SEC. Longitudinal variations along the Pacific equator of the impact of data assimilation on the EUC and SEC precludes the choice of a single site to evaluate the effectiveness of data assimilation schemes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Natl Ctr Environm Predict, Camp Springs, MD USA. RP Halpern, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. EM halpern@pacific.jpl.nasa.gov NR 31 TC 3 Z9 3 U1 2 U2 5 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 1998 VL 15 IS 6 BP 1471 EP 1477 DI 10.1175/1520-0426(1998)015<1471:IOAOST>2.0.CO;2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500018 ER PT J AU Fleming, RJ AF Fleming, RJ TI A note on temperature and relative humidity corrections for humidity sensors SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB A widely used relative humidity (RH) sensor in atmospheric science is based upon a capacitive device that outputs voltage as a linear function of RH and then is corrected by an empirically determined polynomial expression, which is only a function of temperature. Based upon results of a dry bias in these measurements and upon a recent physical-mathematical model of how these devices may work, a new correction formula is derived, which is a function of temperature and RH. The new formula reproduces the old one near 40% RH and corrects the dry bias for RH values less than 40%. C1 NOAA, Environm Res Labs, Boulder, CO 80301 USA. RP Fleming, RJ (reprint author), NOAA, Environm Res Labs, 3300 Mitchell Lane,Suite 175, Boulder, CO 80301 USA. NR 5 TC 5 Z9 5 U1 0 U2 3 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 1998 VL 15 IS 6 BP 1511 EP 1515 DI 10.1175/1520-0426(1998)015<1511:ANOTAR>2.0.CO;2 PG 5 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 165LM UT WOS:000078522500022 ER PT J AU Friedman, CD Costantino, PD Takagi, S Chow, LC AF Friedman, CD Costantino, PD Takagi, S Chow, LC TI BoneSource (TM) hydroxyapatite cement: A novel biomaterial for craniofacial skeletal tissue engineering and reconstruction SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article; Proceedings Paper CT Portland Bone Symposium CY 1997 CL PORTLAND, OREGON DE BoneSource (TM); hydroxyapatite cement; biomaterial; craniofacial skeletal ID BONE-GRAFT SUBSTITUTE; POROUS HYDROXYAPATITE; SURGERY AB BoneSource(TM)-hydroxyapatite cement is a new self-setting calcium phosphate cement biomaterial, Its unique and innovative physical chemistry coupled with enhanced biocompatibility make it useful for craniofacial skeletal reconstruction. The general properties and clinical use guidelines are reviewed. The biomaterial and surgical applications offer insight into improved outcomes and potential new uses for hydroxyapatite cement systems. (C) 1998 John Wiley & Sons, Inc. C1 Fox Chase Canc Ctr, Dept Surg Oncol, Philadelphia, PA 19111 USA. Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Mt Sinai Med Ctr, Dept Otolaryngol Head & Neck Surg, New York, NY 10029 USA. RP Friedman, CD (reprint author), Fox Chase Canc Ctr, Dept Surg Oncol, 7701 Burholme Ave, Philadelphia, PA 19111 USA. EM C-Friedman@FCCC.edu FU NIDCR NIH HHS [DE11789] NR 13 TC 277 Z9 288 U1 1 U2 39 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 WIN PY 1998 VL 43 IS 4 BP 428 EP 432 DI 10.1002/(SICI)1097-4636(199824)43:4<428::AID-JBM10>3.0.CO;2-0 PG 5 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 143MM UT WOS:000077259500010 PM 9855201 ER PT J AU Chapman, WB Blackmon, BW Nizkorodov, S Nesbitt, DJ AF Chapman, WB Blackmon, BW Nizkorodov, S Nesbitt, DJ TI Quantum state-resolved reactive scattering of F+H-2 in supersonic jets: Nascent HF(v,J) rovibrational distributions via IR laser direct absorption methods SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; INTEGRAL CROSS-SECTIONS; MOLECULAR-BEAM; PHOTOELECTRON-SPECTROSCOPY; ANGULAR-DISTRIBUTIONS; REACTION PRODUCTS; REACTION-RATES; DYNAMICS; F+D2; COLLISIONS AB Supersonically cooled discharge radical atom sources are combined with high-sensitivity IR absorption methods to investigate state-to-state reactive scattering of F + n-H-2 --> HF(upsilon, J) + H in low-density crossed supersonic jets at center-of-mass collision energies of 2.4(6) kcal/mole. The product HF(upsilon, J) is probed with full vibrational and rotational quantum state selectivity via direct absorption of a single mode (Delta nu approximate to 0.0001 cm(-1)), tunable F-center laser in the Delta upsilon = 1 fundamental manifold with near shot noise limited detection levels of 10(8) molecules/cm(3)/quantum state per pulse. The high absorption sensitivity, long mean free path lengths, and low-density conditions in the intersection region permit collision-free HF(upsilon, J) rovibrational product state distributions to be extracted for the first time. Summed over all rotational levels, the HF vibrational branching ratios are 27.0(5)%, 54.2(23)%, 18.8(32)%, and <2(2)%, respectively, into upsilon(HF) = 3:2:1:0 The nascent vibrational distributions are in good agreement with rotationally unresolved crossed-beam studies of Neumark et al. [J. Chem. Phys. 82, 3045 (1985)], as well as with full quantum close-coupled calculations of Castillo and Manolopoulos [J. Chem. Phys. 104, 6531 (1996)] on the lowest adiabatic F+H-2 potential surface of Stark and Werner [J. Chem. Phys. 104, 6515 (1996)]. At a finer level of quantum state resolution, the nascent rotational distributions match reasonably well with full quantum theoretical predictions, improving on the level of agreement between theory and experiment from early arrested relaxation studies. Nevertheless, significant discrepancies still exist between the fully quantum state-resolved experiment and theory, especially for the highest energetically allowed rotational levels. (C) 1998 American Institute of Physics. [S0021-9606(98)00545-5]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. New Focus Inc, Santa Clara, CA 95051 USA. RP Nesbitt, DJ (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Nizkorodov, Sergey/I-4120-2014 OI Nizkorodov, Sergey/0000-0003-0891-0052 NR 67 TC 54 Z9 54 U1 1 U2 7 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 1 PY 1998 VL 109 IS 21 BP 9306 EP 9317 DI 10.1063/1.477592 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 141MN UT WOS:000077147900013 ER PT J AU Chirico, RD Cowell, AB Good, WD Klots, TD Knipmeyer, SE Nguyen, A Rau, AP Reynolds, JW Smith, NK Steele, WV AF Chirico, RD Cowell, AB Good, WD Klots, TD Knipmeyer, SE Nguyen, A Rau, AP Reynolds, JW Smith, NK Steele, WV TI Heat capacities, enthalpy increments, phase transitions, and derived thermodynamic functions for the condensed phases of bicyclohexyl between the temperatures 6 K and 440 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE heat capacities; phase transitions; enthalpies of transition ID VIBRATIONAL SPECTROSCOPY; SOLID-PHASES; HYDROGENATION; DIBENZOTHIOPHENE; CONFORMATIONS; CATALYST; BIPHENYL; KINETICS AB Heat capacity and enthalpy measurements by using adiabatic calorimetry for temperatures between 6 K and 440 K are reported for bicyclohexyl (Chemical Abstracts registry number [92-51-3]). The triple point temperature and the enthalpy of fusion were determined. Two different phase-change sequences in the solid state were observed depending upon the thermal history of the sample. Discord between literature values for temperatures and enthalpies of phase transitions are shown to be due to hysteresis effects. Entropies and enthalpies for the condensed phases relative to T --> 0 are reported. Results are compared with literature calorimetric and spectroscopic studies. The stability relationships between the known phases of crystalline bicyclohexyl are established. Planned publications in this series will include reports of measurements leading to the calculation of standard molar Gibbs energies of formation for bicyclohexyl and phenylcyclohexane, and a revised thermodynamic analysis of the (biphenyl + hydrogen) reaction network. (C) 1998 Academic Press. C1 BDM Petr Technol, Bartlesville Thermodynam Grp, Bartlesville, OK 74005 USA. RP Chirico, RD (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. EM rchirico@aol.com NR 24 TC 5 Z9 5 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD DEC PY 1998 VL 30 IS 12 BP 1423 EP 1439 DI 10.1006/jcht.1998.0399 PG 17 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 155KY UT WOS:000077947000002 ER PT J AU Dettinger, MD Cayan, DR Diaz, HF Meko, DM AF Dettinger, MD Cayan, DR Diaz, HF Meko, DM TI North-south precipitation patterns in western North America on interannual-to-decadal timescales SO JOURNAL OF CLIMATE LA English DT Article ID UNITED-STATES; INTERDECADAL VARIABILITY; ATMOSPHERIC CIRCULATION; CALIFORNIA; PACIFIC; TEMPERATURES; EXTREME; TIME AB The overall amount of precipitation deposited along the West Coast and western cordillera of North America from 25 degrees to 55 degrees N varies from year to year, and superimposed on this domain-average variability are varying north-south contrasts on timescales from at least interannual to interdecadal. In order to better understand the north-south precipitation contrasts, their interannual and decadal variations are studied in terms of how much they affect overall precipitation amounts and how they are related to large-scale climatic patterns. Spatial empirical orthogonal functions (EOFs) and spatial moments (domain average, central latitude, and latitudinal spread) of zonally averaged precipitation anomalies along the westernmost parts of North America are analyzed, and each is correlated with global sea level pressure (SLP) and sea surface temperature series, on interannual (defined here as 3-7 yr) and decadal (>7 yr) timescales. The interannual band considered here corresponds to timescales that are particularly strong in tropical climate variations and thus is expected to contain much precipitation variability that is related to El Nino-Southern Oscillation; the decadal scale is defined so as to capture the whole range of long-term climatic variations affecting western North America. Zonal EOFs of the interannual and decadal filtered versions of the zonal-precipitation series are remarkably similar. At both timescales, two leading EOFs describe I) a north-south seesaw of precipitation pivoting near 40 degrees N and 2) variations in precipitation near 40 degrees N, respectively. The amount of overall precipitation variability is only about 10% of the mean and is largely determined by precipitation variations around 40 degrees-45 degrees N and most consistently influenced by nearby circulation patterns; in this sense, domain-average precipitation is closely related to the second EOF. The central latitude and latitudinal spread of precipitation distributions are strongly influenced by precipitation variations in the southern parts of western North America and are closely related to the first EOF Central latitude of precipitation moves south (north) with tropical warming (cooling) in association with midlatitude western Pacific SLP variations, on both interannual and decadal timescales. Regional patterns and zonal averages of precipitation-sensitive tree-ring series are used to corroborate these patterns and to extend them into the past and appear to share much long- and short-term information with the instrumentally based zonal precipitation EOFs and moments. C1 US Geol Survey, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Scripps Inst Oceanog, Div Climate Res, La Jolla, CA USA. NOAA, Environm Res Lab, CDC, Boulder, CO 80303 USA. Univ Arizona, Tree Ring Res Lab, Tucson, AZ 85721 USA. RP Dettinger, MD (reprint author), US Geol Survey, Scripps Inst Oceanog, 9500 Gilman Dr,Dept 0224, La Jolla, CA 92093 USA. NR 40 TC 239 Z9 242 U1 4 U2 26 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 DEC PY 1998 VL 11 IS 12 BP 3095 EP 3111 DI 10.1175/1520-0442(1998)011<3095:NSPPIW>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 151ZY UT WOS:000077751700002 ER PT J AU Cayan, DR Dettinger, MD Diaz, HF Graham, NE AF Cayan, DR Dettinger, MD Diaz, HF Graham, NE TI Decadal variability of precipitation over western North America SO JOURNAL OF CLIMATE LA English DT Article ID UNITED-STATES; CLIMATE VARIABILITY; HEIGHT FIELD; ATMOSPHERIC CIRCULATION; SOUTHERN OSCILLATION; HEMISPHERE WINTER; PATTERNS; PACIFIC; TEMPERATURE; STREAMFLOW AB Decadal (>7- yr period) variations of precipitation over western North America account for 20%-50% of the variance of annual precipitation. Spatially, the decadal variability is broken into several regional [O(1000 km)] components. These decadal variations are contributed by fluctuations in precipitation from seasons of the year that vary from region to region and that are not necessarily concentrated in the wettest season(s) alone. The precipitation variations are linked to various decadal atmospheric circulation and SST anomaly patterns where scales range from regional to global scales and that emphasize tropical or extratropical connections, depending upon which precipitation region is considered. Further, wet or dry decades are associated with changes in frequency of at least a few shea-period circulation "modes" such as the pacific-North American pattern. precipitation fluctuations over the southwestern United States and the Saskatchewan region of western Canada are associated with extensive shifts of sea level pressure and SST anomalies, suggesting that they are components of low-frequency precipitation variability from global-scale climate processes. Consistent with the global scale of its pressure and SST connection, the Southwest decadal precipitation is aligned with opposing precipitation fluctuations in northern Africa. C1 Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, La Jolla, CA 92093 USA. US Geol Survey, Div Water Resources, Div Climate Res, La Jolla, CA 92093 USA. NOAA, Environm Res Lab, CDC, Boulder, CO 80303 USA. RP Cayan, DR (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, La Jolla, CA 92093 USA. NR 58 TC 203 Z9 205 U1 1 U2 13 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1998 VL 11 IS 12 BP 3148 EP 3166 DI 10.1175/1520-0442(1998)011<3148:DVOPOW>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 151ZY UT WOS:000077751700005 ER PT J AU Kumar, A Hoerling, MP AF Kumar, A Hoerling, MP TI Annual cycle of Pacific North American seasonal predictability associated with different phases of ENSO SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO; INTERANNUAL VARIABILITY; PREDICTIONS; TRANSIENTS; ANOMALIES AB The potential for seasonal mean predictability over the Pacific and North American regions is evaluated as a function of the amplitude of equatorial Pacific sea surface temperature forcing, the phase of that forcing, and the phase of the annual cycle. The potential predictability is measured as the ratio of the seasonal mean SST-forced signal and the internally generated seasonal mean noise. The authors' assessments are derived from the output of ensemble atmospheric general circulation model experiments forced with observed monthly SSTs for 1950-94. Using a perfect prognostic approach, results are presented on the predictability of upper-tropospheric circulation, North American land temperature, and precipitation. Seasonal predictability is shown to depend on the amplitude of the SST-forced signal, whereas the background noise is largely independent of SSTs. To zero order, that signal grows linearly with the amplitude of anomalous SSTs. An important departure from this is with respect to the phase of tropical Pacific SST anomalies, and the simulated atmospheric signals were stronger for ENSO's extreme warm phases compared to ENSO's extreme cold phases. This asymmetry can be traced throughout the teleconnection chain that links the ENSO forcing region with North American climate. With regard to the annual cycle's role, the North American climate is shown to be most predictable during the late winter and early spring season of warm events. This stems from the fact that the SST-forced signal during warm events at that time of year is only slightly weaker than in midwinter, whereas the background noise is substantially reduced. Predictability during spring is significantly greater than that occurring in fall, due to a much weaker fall signal. Observational analyses are presented that corroborate these key model results, in particular enhanced skill during ENSO's warm phase and a springtime predictability peak. Finally, a comparison is made between the classic ratio of variance measure of predictability that commingles all warm, cold, and non-ENSO years to yield a single estimate, against such a ratio calculated for individual events. North American seasonal predictability for specific events can greatly exceed this single gross measure, and it is shown that the latter is a poor yardstick of the prospects for skillful predictions during extreme ENSO states. C1 Univ Colorado, CIRES, Climate Diagnost Ctr, Boulder, CO 80309 USA. NOAA, NCEP, EMC, Climate Modeling Branch, Washington, DC USA. RP Hoerling, MP (reprint author), Univ Colorado, CIRES, Climate Diagnost Ctr, Campus Box 449, Boulder, CO 80309 USA. NR 23 TC 92 Z9 94 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1998 VL 11 IS 12 BP 3295 EP 3308 DI 10.1175/1520-0442(1998)011<3295:ACOPNA>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 151ZY UT WOS:000077751700013 ER PT J AU Smith, TM Reynolds, RW AF Smith, TM Reynolds, RW TI A high-resolution global sea surface temperature climatology for the 1961-90 base period SO JOURNAL OF CLIMATE LA English DT Article AB In an earlier study (Reynolds and Smith), a monthly 1 degrees SST climatology was produced for the 1950-79 base period. This climatology was constructed from two intermediate climatologies: a 2 degrees SST climatology developed from in situ data for the period 1950-79, and a 1 degrees SST climatology for the period 1982-93 derived from an optimum interpolation SST analysis that uses in situ and satellite data. Since then a new 2 degrees spatial resolution near-global SST analysis has been developed which can produce a similar high-resolution climatology for any base period within the analysis period (1950-92). In this note the procedure is utilized to change the base period to 1961-90, which is the climatological base period suggested by the World Meteorological Organization. The method is nearly identical to that used in the earlier study except for the formation of the 2 degrees climatology from new analyses. The results show that the change in the climatology is generally small with absolute differences usually less than 0.2 degrees C. As with the earlier climatology, in regions where insufficient in situ observations are available prior to 1982 there is no adjustment. In those regions, which include the Southern Ocean, the climatology base period is 1982-96. C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC 20233 USA. RP Smith, TM (reprint author), W-NP52,4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 6 TC 77 Z9 78 U1 2 U2 7 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 DEC PY 1998 VL 11 IS 12 BP 3320 EP 3323 DI 10.1175/1520-0442(1998)011<3320:AHRGSS>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 151ZY UT WOS:000077751700015 ER PT J AU Lowery, TA AF Lowery, TA TI Difference equation-based estuarine flushing model application to US Gulf of Mexico estuaries SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE estuarine volumetrics; salinity regime characterizations; tidal reflux; tidal exchange; freshwater input; dynamic equilibria; systems modeling AB Estuarine flushing is conceptually simple. However, the use of simple "ratio type" estuarine flushing estimators generates estimates that are often inadequate and unverifiable. Obviously, estuarine flushing estimators that address more of the complexities of the flushing processes are needed. Difference equations lend themselves to modeling complex systems by virtue of their mathematical stability and ability to be linked into long complex inter-connecting series. With the above in mind, a simple to use model based on difference equations was developed for the explicit purpose of generating more realistic estuarine flushing estimates. The model and its application to a series of US Gulf of Mexico estuaries are presented in this paper. Estuarine oceanographers will recognize the relationships driving the model. However, an in-depth knowledge of estuarine oceanography is not required to understand or operate the model. Average estuary volume and average intertidal volume are used to drive the model as it tracks freshwater retention and flushing via tidal cycles. The configuration of the model accommodates vertically homogeneous and stratified salinity/flushing regimes. Application of the model to a series of U.S. Gulf of Mexico estuaries yields a 79% agreement between the model's freshwater input estimates and empirically derived freshwater input estimates. Linear regression analysis of the freshwater estimates of the model versus the empirically derived freshwater estimates, yields a r(2) of 0.98 for the estuaries modeled. The empirically derived freshwater estimates were used to approximate the salt-content of the estuaries as a check of their appropriateness for use in verifying the model. Comparison of the "empirically derived freshwater based salt-content approximations" versus "salt-content approximations based on the observed salinities of the estuaries" yields a 74% agreement, while linear regression yields a r(2) of 0.81 for the estuaries modeled. This generic model can be applied to estuaries with known low tide estuary volumes, intertidal volumes, and salinity characterizations. Electronic copies of the programming of the model are available from the author. C1 NOAA, Strateg Environm Assessments Div, Silver Spring, MD 20910 USA. RP Lowery, TA (reprint author), NOAA, Strateg Environm Assessments Div, N-ORCA 1,SSMC4,1305 East West Highway, Silver Spring, MD 20910 USA. NR 20 TC 7 Z9 7 U1 0 U2 1 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1998 VL 14 IS 1 BP 185 EP 195 PG 11 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA YT592 UT WOS:000071622500016 ER PT J AU Van de Voorde, NE Dinnel, SP AF Van de Voorde, NE Dinnel, SP TI Observed directional wave spectra during a frontal passage SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE directional waves; wave energy; wave-energy lag time; wave field data; northeastern Gulf of Mexico; National Data Buoy Center (NOAA); nonlinear wave process; and cold-front ID SEA; WINDS; BUOYS AB This paper qualitatively discusses the changes in the directional wave field as the result of an atmospheric cold front passage. The directional wave data were measured using a 3-m discus buoy in the north-eastern Gulf of Mexico using a Longuet-Higgins technique with 46 frequency bands (0.0325 to 0.485 Hz). Changes in the directional wave spectra were examined during a 4-day period that included a major wind shift under both quasi-steady and nonsteady wind fields. A procedure of combining the wave-energy into four directional quadrants, in lieu of individual mean directions, was examined as an analytical time-series technique for directional wave spectra. The lag time between a wind speed increase and a corresponding increase in wave-energy was shown to be a function of the existing sea state with shorter lag times for a higher sea condition. A numerical model analysis of VAN VLEDDER and HOLTHUIJSEN (1988) indicated that after a major wind shift the wave-energy would not only move to lower frequencies, but would also rotate to realign with the direction of the older wind field. The conclusions of VAN VLEDDER and HOLTWUIJSEN (1988) were supported by direct observations of pre- and post-frontal wave fields. Hourly, polar contoured, directional wave spectra plots show a narrow frequency band energy bridge between the two wave fields. The development of an energy bridge is shown to correspond to a change in the decay rate of the old wave field. C1 Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. Univ So Mississippi, Ctr Marine Sci, Stennis Space Ctr, MS 39529 USA. RP Van de Voorde, NE (reprint author), 8th Coast Guard Dist, 501 Magazine St, New Orleans, LA 70130 USA. NR 28 TC 2 Z9 2 U1 0 U2 4 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1998 VL 14 IS 1 BP 337 EP 346 PG 10 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA YT592 UT WOS:000071622500028 ER PT J AU Gupta, JA Woicik, JC Watkins, SP Miyano, KE Pellegrino, JG Crozier, ED AF Gupta, JA Woicik, JC Watkins, SP Miyano, KE Pellegrino, JG Crozier, ED TI An X-ray standing wave study of ultrathin InAs films in GaAs(001) grown by atomic layer epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 9th International Conference on Metalorganic Vpour Phase Epitaxy (ICMOVPE-IX) CY MAY 31-JUN 04, 1998 CL LA JOLLA, CALIFORNIA DE InAs; GaAs; XSW; ALE; MOCVD; diffraction ID HETEROSTRUCTURES; GAAS; EMISSION; PHOTOLUMINESCENCE; SUBMONOLAYERS; STRAIN AB X-ray standing wave and X-ray diffraction measurements were used to determine the structure of nominal 1 monolayer and 1/2 monolayer InAs films buried in GaAs(001). The films were grown by atomic layer epitaxy using trimethylgallium, tertiarybutylarsine and trimethylindium. For the full monolayer sample the standing wave measurement shows that the indium atoms reside 1.577 +/- 0.014 Angstrom above the GaAs(004) substrate planes. A calculation based on the macroscopic elastic theory suggests that this corresponds to a single InxGa1-xAs layer with x = 0.794 +/- 0.068. The coherent fraction of 0.766 +/- 0.051 indicates a reasonably abrupt interface, as confirmed by the In-excitonic photoluminescence full width at half maximum of 5.74 +/- 0.01 meV. The half monolayer sample is less strained, as expected, with the indium atoms at 1.502 +/- 0.030 Angstrom above the substrate planes, corresponding to an InxGa1-xAs layer with x = 0.446 +/- 0.145, and a coherent fraction of 0.88 +/- 0.12. This study exemplifies the complimentary nature of XSW and XRD. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. CUNY Brooklyn Coll, Dept Phys, Brooklyn, NY 11210 USA. RP Watkins, SP (reprint author), Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. NR 23 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 1998 VL 195 IS 1-4 BP 34 EP 40 DI 10.1016/S0022-0248(98)00636-8 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 153NM UT WOS:000077839200007 ER PT J AU Xu, HHK Liao, H Eichmiller, FC AF Xu, HHK Liao, H Eichmiller, FC TI Indentation creep behavior of a direct-filling silver alternative to amalgam SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE amalgam; creep mechanism; hardening; indentation; silver; subsurface deformation ID DENTAL AMALGAM; MICROSTRUCTURE; COMPOSITES; CORROSION; HARDNESS; FATIGUE; RESTORATIONS; MECHANISMS AB Amalgam creep has been identified as a key parameter associated with marginal breakdown and corrosion. The aim of this study was to evaluate the time-dependent deformation (creep) of a novel silver filling material as an alternative to amalgam. We made the silver specimens by pressing a precipitated powder at room temperature to a density that can be achieved in clinical hand consolidation. The surface of the silver was either polished or burnished. To examine local contact creep and the effect of surface finishing, we used an indentation creep method in which a Vickers indenter was loaded on the specimen surface at a load of 10 N with dwell times of 5 sec to 6 x 10(4) sec. We used a bonded-interface technique to examine subsurface creep mechanisms. The flexural strength (mean +/- SD; n = 10) was 86 +/- 20 MPa for amalgam, 180 +/- 21 MPa for polished silver, and 209 +/- 19 MPa for burnished silver-values which are significantly different from each other (family confidence coefficient = 0.95; Tukey's multiple-comparison test). Indentation creep manifested as hardness number decreasing with increased dwell time. With dwell time increasing from 5 sec to 6 x 104 sec, the hardness number of amalgam was reduced by approximately 80%; that of the polished silver and the burnished silver was reduced by only 40%. Subsurface creep in amalgam consisted of the shape change of the alloy particles from spherical to elongated shapes, and the separation of matrix grains from each other, possibly due to grain-boundary sliding. Creep of the polished silver occurred by densification reducing porosity and increasing hardness; that of the burnished silver occurred by the displacement of the burnished layer. These results suggest that, due to creep-induced subsurface work-hardening and densification, the consolidated sliver exhibits a higher resistance to indentation creep than does amalgam. The hardness number of silver approaches that of amalgam after prolonged indentation loading. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [IA 1Y01 DE30045, P 50 DE09322] NR 44 TC 6 Z9 6 U1 0 U2 2 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD DEC PY 1998 VL 77 IS 12 BP 1991 EP 1998 PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 142PL UT WOS:000077209000007 PM 9839787 ER PT J AU Read, DT AF Read, DT TI Special section on application of fracture mechanics in electronic packaging - Preface SO JOURNAL OF ELECTRONIC PACKAGING LA English DT Editorial Material C1 Natl Inst Stand & Technol, Mat Reliabil Div, Boulder, CO 80302 USA. RP Read, DT (reprint author), Natl Inst Stand & Technol, Mat Reliabil Div, Boulder, CO 80302 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1043-7398 J9 J ELECTRON PACKAGING JI J. Electron. Packag. PD DEC PY 1998 VL 120 IS 4 BP 321 EP 321 DI 10.1115/1.2792640 PG 1 WC Engineering, Electrical & Electronic; Engineering, Mechanical SC Engineering GA 153KW UT WOS:000077833100001 ER PT J AU Chi, PJ Russell, CT Bloom, RM Singer, HJ AF Chi, PJ Russell, CT Bloom, RM Singer, HJ TI Solar wind control of ultralow-frequency wave activity at L=3 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HYDROMAGNETIC ENERGY-SPECTRA; INTERPLANETARY MAGNETIC-FIELD; LOW GEOMAGNETIC LATITUDES; FLUX-TRANSFER EVENTS; DAYSIDE MAGNETOSPHERE; IMF ORIENTATION; CONE ANGLE; ULF WAVES; PULSATIONS; DEPENDENCE AB This study explores the statistical relationships between 2 years of solar wind data recorded by the IMP 8 spacecraft and data from the Mount Clemens magnetometer station (L = 3) to improve our understanding of possible energy sources of ULF wave activity. Within the four frequency bands, f = 4-8 mHz, 8-16 mHz, 16-32 mHz, and 32-64 mHz, that are studied, two distinct types of waves are found. One is at high frequencies corresponding to Pc3 pulsations, and the other is at low frequencies corresponding to Pc5 and low-frequency Pc4 pulsations. The high-frequency part clearly has an energy source in the upstream foreshock. However, our analysis shows that the magnetospheric cusps do not appear to be the conduit of energy for the wave activity in this low-latitude region. The low-frequency activity occurs most frequently and has greater wave power when the interplanetary magnetic field is southward. This correlation suggests that the major energy source of these low-frequency waves is substorm-related or is related to the reconnection on the dayside magnetopause. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Pacific Sierra Res, Santa Monica, CA 90405 USA. NOAA, RESE, Boulder, CO 80303 USA. RP Chi, PJ (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Box 951567, Los Angeles, CA 90095 USA. NR 44 TC 13 Z9 16 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 1998 VL 103 IS A12 BP 29467 EP 29477 DI 10.1029/98JA02161 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 149MD UT WOS:000077608400028 ER PT J AU Wygant, J Rowland, D Singer, HJ Temerin, M Mozer, F Hudson, MK AF Wygant, J Rowland, D Singer, HJ Temerin, M Mozer, F Hudson, MK TI Experimental evidence on the role of the large spatial scale electric field in creating the ring current SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC CONVECTION; GEOMAGNETIC STORM; MAGNETIC STORM; MARCH 24; 1991 SSC; SIMULATION; IONS; PLASMASPHERE; INSTRUMENT; TRANSPORT AB This paper presents the first simultaneous in situ measurements of the large-scale convection electric field and the ring current induced magnetic field perturbations in the equatorial plane of the inner magnetosphere and compares them to the evolution of major geomagnetic storms as characterized by Dst. The measurements were obtained from the University of California, Berkeley double-probe electric field experiment and the Air Force Geophysics Laboratory fluxgate magnetometer on the CRRES spacecraft. This spacecraft had an apogee near geosynchronous orbit and a perigee near 300 km altitude. We focus on the major geomagnetic storm on March 24, 1991, for which the maximum negative excursion of Dst was about -300 nT. During the main phase of the storm, the large-scale electric field repeatedly penetrated earthward, maximizing between L=2 and L=4 with magnitudes of 6 mV/m. These magnitudes were larger than quiet time values of the electric field by a factor of 60 or more. Electric potential drops across the dusk region from L=2 to L=4 ranged up to 50-70 kV in concert with increases in Kp up to 9 and dDst/dt (an indicator of the net ring current injection rate) which ranged up to -50 nT/hr. These electric fields lasted for time periods of the order of an hour or more and were capable of injecting ring current ions from L=8 to L=2.4 and energizing particles from initial plasma sheet energies of 1-5 keV up to 300 keV through conservation of the first adiabatic invariant. The data obtained during the recovery phase of this storm provide the first direct experimental evidence in the equatorial plane that the electric field is systematically diminished or shielded earthward of the inner edge of the ring current during this phase of the geomagnetic storm. Also observed during the 2-week recovery phase were episodic enhancements in the electric field which coincided and were colocated with enhancements of in situ ring current intensity and which also coincided with decreases in Dst. These enhancements in the electric field and in the ring current magnetic field perturbation occurred at progressively larger radial positions as the recovery phase continued. Evidence for regions of reversed convection near midnight during the recovery phase is provided. An unexpected and important feature of this data set, during both main and recovery phases, near 1800-2100 MLT, is that electric fields are often much stronger earthward of L=4 or L=5 than at positions more distant than L=6. This suggests important features of the interaction between the hot ring current plasma and the large-scale electric field in the inner magnetosphere ate not yet understood. C1 Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Wygant, J (reprint author), Univ Minnesota, Sch Phys & Astron, 116 Church St SE, Minneapolis, MN 55455 USA. EM wygant@ham.space.umn.edu RI Rowland, Douglas/F-5589-2012 OI Rowland, Douglas/0000-0003-0948-6257 NR 55 TC 140 Z9 142 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-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1998 VL 103 IS A12 BP 29527 EP 29544 DI 10.1029/98JA01436 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 149MD UT WOS:000077608400033 ER PT J AU Sokol, PE Brown, DW Fitzgerald, S AF Sokol, PE Brown, DW Fitzgerald, S TI An inelastic neutron scattering study of H-2 in Vycor glass SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Quantum Fluids and Solids (QFS98) CY JUN 09-14, 1998 CL AMHERST, MASSACHUSETTS ID MOLECULAR-HYDROGEN; ADSORPTION AB The orientational properties of n-H-2 confined in Vycor have been studied via inelastic neutron spectroscopy. We observe two distinct rotational transitions which we ascribe to H-2 in the center of the pore and H2 strongly bound to the surface. The molecules on the surface can be modeled as rotationally hindered rotors, and a distribution of orientational potentials is extracted. C1 Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Sokol, PE (reprint author), Penn State Univ, Dept Phys, University Pk, PA 16802 USA. NR 9 TC 2 Z9 2 U1 1 U2 2 PU PLENUM PUBL CORP 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 1998 VL 113 IS 5-6 BP 717 EP 722 DI 10.1023/A:1022509712898 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 140RA UT WOS:000077101100012 ER PT J AU Dickey, JT Swanson, P AF Dickey, JT Swanson, P TI Effects of sex steroids on gonadotropin (FSH and LH) regulation in coho salmon (Oncorhynchus kisutch) SO JOURNAL OF MOLECULAR ENDOCRINOLOGY LA English DT Article ID 2 DISTINCT GONADOTROPINS; PITUITARY-GONADAL AXIS; CELL GTH RESPONSE; BETA SUBUNIT GENE; RAINBOW-TROUT; MOLECULAR-CLONING; II-BETA; REPRODUCTIVE-CYCLE; PLASMA GONADOTROPIN; GOLDFISH PITUITARY AB The effect of steroid hormone treatment on coho salmon (Oncorhynchus kisutch) was examined. The cDNAs for coho salmon FSH beta and LH beta subunits were cloned and sequenced using reverse transcriptase PCR. Northern blot analysis revealed that a single transcript of 1 kb for each of these subunits was present in the pituitaries of vitellogenic and spermiating coho salmon. RNase protection assays (RPAs) were developed to quantify FSH beta and LH beta subunit transcript levels. For the RPAs, antisense RNA probes and sense RNA standards were prepared from a region of the cDNAs which spanned the signal peptide and a portion of the mature protein. These RPAs were used to examine the effects of exogenous steroids including testosterone, estradiol-17 beta (E2) and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-P) in vivo, in coho salmon at three time points during the spring period of gonadal growth when plasma levels of FSH are increasing. Both testosterone and E2 increased steady state mRNA levels of LH beta, whereas E2 decreased steady state mRNA levels of FSH beta in one experiment. Thus, the RPAs were able to detect changes in steady state mRNA levels in response to exogenous steroid treatment. Plasma and pituitary levels of FSH and LP-I were also measured using IIIA. Throughout the experimental series, FSH plasma levels decreased in response to exogenous testosterone and E2 administration, while 17 alpha, 20 beta-P had no effect on FSH plasma levels. Plasma LH levels were not detected throughout the course of the experiment. Pituitary LH increased in response to testosterone and E2, while pituitary FSH levels did not change. 17 alpha,20 beta-P had no effect on pituitary FSH or LH content during the experiment. Thus, regulation of the gonadotropins in coho salmon occurs at both the transcriptional as well as the translational level. Testosterone and E2 appear to have negative feedback effects on FSH, but positive feedback on LH. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Dickey, JT (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 73 TC 91 Z9 92 U1 0 U2 10 PU SOC ENDOCRINOLOGY PI BRISTOL PA 17/18 THE COURTYARD, WOODLANDS, BRADLEY STOKE, BRISTOL BS32 4NQ, ENGLAND SN 0952-5041 J9 J MOL ENDOCRINOL JI J. Mol. Endocrinol. PD DEC PY 1998 VL 21 IS 3 BP 291 EP 306 DI 10.1677/jme.0.0210291 PG 16 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 154ZG UT WOS:000077920600005 PM 9845670 ER PT J AU Suenram, RD Lovas, FJ Walker, ARH Dixon, DA AF Suenram, RD Lovas, FJ Walker, ARH Dixon, DA TI Rotational spectrum, structure, and electric dipole moment of bis(difluoromethyl) ether SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID THERMODYNAMIC PROPERTIES AB The rotational spectrum of bis(difluoromethyl) ether (CF(2)HOCF(2)H) has been observed and analyzed using both a conventional Stark-modulated microwave spectrometer and a pulsed molecular beam Fabry-Perot cavity microwave (FTMW) spectrometer. The lowest energy conformer studied here has a (hydrogen) syn-anti conformation. The high sensitivity of the FTMW spectrometer permits observation and analysis of the (13)C, (18)O and (2)H isotopomers in natural abundance. The electric dipole moment was measured for the normal species and found to be mu(a), = 5.020(7) x 10(-30) C.m [1.505(2) D], mu(b) = 0.19(4) x 10(-30) C.m [0.056(11) D], mu(c) = 0.48(2) x 10(-30) C.m [0.144(7) D], and mu(T) = 5.047(10) x 10(-30) C.m [1.513(3) D]. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Suenram, RD (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Hight Walker, Angela/C-3373-2009 OI Hight Walker, Angela/0000-0003-1385-0672 NR 16 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 1998 VL 192 IS 2 BP 441 EP 448 DI 10.1006/jmsp.1998.7713 PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 145FH UT WOS:000077360000022 ER PT J AU Dadmun, MD Clingman, S Ober, CK Nakatani, AI AF Dadmun, MD Clingman, S Ober, CK Nakatani, AI TI Flow-induced structure in a thermotropic liquid crystalline polymer as studied by SANS SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article; Proceedings Paper CT American-Physical-Society Meeting CY MAR 19, 1998 CL LOS ANGELES, CALIFORNIA SP Amer Phys Soc DE liquid crystalline polymer; shear alignment; thermotropic polymer; small-angle neutron scattering; flow-induced structure ID NEUTRON-SCATTERING; SHEAR; POLYETHER; VISCOSITY; PHASE; MELTS AB Small-angle neutron scattering is utilized to determine the flow induced alignment of a model thermotropic liquid crystalline polymer (LCP) as a function of shear rate and temperature. The results demonstrate that the flow-induced structures in thermotropic liquid crystalline polymers have similarities and differences to those in lyotropic liquid crystalline polymer solutions. The shear rate dependence of the alignment shows that the flow-induced alignment correlates very well to the viscosity behavior of the LCP in the shear thinning regime, while temperature variation results in a change in the extent of alignment within the nematic phase. Relaxation results also demonstrate that the flow-induced alignment remains essentially unchanged for up to an hour after the shear field has been removed. Last, there exists a regime at low shear rate and low temperature where alignment of the LCP molecule perpendicular to the applied shear flow is stable. These results provide important experimental evidence of the molecular level changes that occur in a thermotropic liquid crystalline polymer during flow, which can be utilized to develop theoretical models and more efficiently process thermotropic polymers. (C) 1998 John Wiley & Sons, Inc. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Dadmun, MD (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 22 TC 12 Z9 12 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD DEC PY 1998 VL 36 IS 17 BP 3017 EP 3023 PG 7 WC Polymer Science SC Polymer Science GA 144AP UT WOS:000077290500002 ER PT J AU Merfeld, GD Karim, A Majumdar, B Satija, SK Paul, DR AF Merfeld, GD Karim, A Majumdar, B Satija, SK Paul, DR TI Interfacial thickness in bilayers of poly(phenylene oxide) and styrenic copolymers SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article; Proceedings Paper CT American-Physical-Society Meeting CY MAR 19, 1998 CL LOS ANGELES, CALIFORNIA SP Amer Phys Soc DE interfacial thickness; PPO; SAN; SMA; neutron reflectivity NR; binary interaction energies ID POLYMER-POLYMER INTERFACES; MOLECULAR-WEIGHT DEPENDENCE; PHASE-BEHAVIOR; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); POLY(2,6-DIMETHYLPHENYLENE OXIDE); POLY(METHYL METHACRYLATE); ACRYLONITRILE COPOLYMERS; TEMPERATURE-DEPENDENCE; INTERACTION PARAMETERS; NEUTRON REFLECTION AB Estimates for the thickness of the interface between poly (2,6-dimethyl-1, 4-phenylene oxide) (PPO) and copolymers of styrene-acrylonitrile (SAN) and styrene-maleic anhydride (SMA) based on the theory of Helfand and Tagami are compared to neutron reflectivity (NR) measurements. Good agreement is found between the NR measurements and theoretical predictions that make use of a mean field binary interaction model and previously reported binary interaction energies. The techniques outlined in this work may be used to understand relationships between the mechanical properties of multiphase polymer blends and the fundamental thermodynamics of polymer interactions. (C) 1998 John Wiley & Sono, Inc. C1 Univ Texas, Ctr Polymer Res, Austin, TX 78712 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. Gen Elect Plast, Selkirk, NY 12158 USA. NIST, Reactor Div, Gaithersburg, MD 20899 USA. RP Paul, DR (reprint author), Univ Texas, Ctr Polymer Res, Austin, TX 78712 USA. NR 41 TC 17 Z9 17 U1 1 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD DEC PY 1998 VL 36 IS 17 BP 3115 EP 3125 DI 10.1002/(SICI)1099-0488(199812)36:17<3115::AID-POLB11>3.0.CO;2-H PG 11 WC Polymer Science SC Polymer Science GA 144AP UT WOS:000077290500011 ER PT J AU Rugolo, LJ Knotts, KS Lange, AM Crecco, VA AF Rugolo, LJ Knotts, KS Lange, AM Crecco, VA TI Stock assessment of Chesapeake Bay blue crab (Callinectes sapidus Rathbun) (vol 17, pg 493, 1998) SO JOURNAL OF SHELLFISH RESEARCH LA English DT Correction DE blue crab; Callinectes sapidus; Chesapeake Bay; harvest; population; fishery; exploitation; stuck assessment; status; gear saturation ID MODEL AB This stack assessment stemmed from concerns about declines in Chesapeake Bay blue crab commercial yield, survey abundance indices, and economic performance in the 1990s. Blue crab vital rates and life-history characteristics were described. A risk-averse approach was adopted for parameter estimation. Extant (50 y) fisheries-independent and dependent data were compiled. Current spawning stock biomass was at moderate levels, as compared to historical maxima; total stock biomass was at long-term average levels since 1956. Juvenile recruitment has been variable since the 1950s. The stock is in long-term dynamic equilibrium, demonstrating variable abundance as expected in a strongly r-selected species. No evidence of a persistent stock decline was found. The decade of the 1980s was a period of above avenge abundance; the population modulated to average levels thereafter. Maryland commercial catch per unit effort (CPUE) has remained fairly stable from 1982 to 1995. Baywide yield varied without trend since 1945, cycling around the long-term mean with peaks in 1950, 1966, 1981, and 1993 and troughs in the mid-1950s and late 1970s to early 1980s. Baywide data since 1945 demonstrated a fivefold increase in directed effort (f) and an exponential decline in CPUE: rapidly from 1947 to 1967, and without trend since 1970. The stock has supported maximum sustainable yield (MSY) = 37-38.5 x 10(6) kg since 1945 with no observed change in the ability of the stock to replace itself or to provide historical avenge yield. We judged the stock to be moderately to fully exploited at avenge levels of abundance. Stock-recruitment (S-R) analysis revealed weak relationships. Density-independent effects accounted for little of the variability in the S-R model. Exploitation rates for 1956 to 1996 ranged from 30-45% for peeler/soft crabs and 40-55% for hard crabs. Fishing mortality (F) ranged largely between 0.8-1.0 (F < 1.20) since 1956 within +/- 20% of the long-term mean; fully recruited F in 1996 was 0.87. Current F was below the threshold reference level of F-10% = 1.21, where F-REP = 1.17. Yield per recruit (YPR) modeling estimated F-0.1 = 0.36 and F-MAX = 0.64. The stock is strictly growth overfished with a 26% reduction in F-1996 required to maximize (+2% gain) YPR. Longevity was established at 8 y. Tagging studies showed that blue crabs live considerably longer than current convention (3 y). A life-table model reconciled the apparent disparity between this convention and the life-history parameters used in the assessment. At current total mortality (Z) approximate to 1.3, the mean age of the observed stock would be 1.5 y (153 mm CW [carapace width]); 97.3% of all individuals would be less than or equal to 3 y of age. The dramatic rise in f since 1945 with the accompanying decline in CPUE was not associated with an increase in F. Catchability (q) has varied with f from 1956 to 1995 as a result of gear saturation. Moderate reductions in f would not result in a proportional reduction in F because of nonconstant q. The blue crab fishery is severely overcapitalized in terms of total effort. As a result of gear saturation, marginal decreases in fishing effort would not realize proportional gains in CPUE, %MSP, or YPR. Substantial economic displacement would be required to maximize YPR. Increases in %MSP and YPR could be realized through increased size limits and regulating the taking of mature female crabs,without the displacement costs associated with effort reductions alone. We recommend a risk-averse management strategy: maintain current F below F. Management should be particularly averse to increases in effort that would exacerbate current economic inefficiencies, or to increases in gear efficiency. The latter concern acknowledges the delicate interplay between F and f in the fishery. Management should be proactive: stabilize and enhance the economic viability of the fishery and provide protection for the stock through maintenance of greater than or equal to 10% maximum spawning potential (MSP). It should consider adapting strategies which increase YPR (e.g., size limit measures on both sexes) and spawning potential (e.g., limit directed fisheries on mature female crabs). C1 Maryland Dept Nat Resources, Annapolis, MD 21401 USA. NOAA, Off Intergovt & Recreat Fisheries, Natl Marine Fisheries Serv, Silver Spring, MD 20912 USA. Connecticut Dept Environm Protect, Div Fisheries, Old Lyme, CT 06371 USA. RP Rugolo, LJ (reprint author), Maryland Dept Nat Resources, Annapolis, MD 21401 USA. NR 30 TC 3 Z9 3 U1 1 U2 9 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 1998 VL 17 IS 3 BP 905 EP 930 PG 26 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 160UU UT WOS:000078250300052 ER PT J AU Stoner, AW Mehta, N Ray-Culp, M AF Stoner, AW Mehta, N Ray-Culp, M TI Mesoscale distribution patterns of Queen Conch (Strombus gigas linne) in Exuma Sound, Bahamas: Links in recruitment from larvae to fishery yields SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE fishery; habitat; larval supply; mesoscale; oceanography; postsettlement; presettlement; recruitment ID CORAL-REEF FISH; BENTHIC MARINE-INVERTEBRATES; DEEP-WATER HABITATS; POPULATION-STRUCTURE; SEAGRASS MEADOWS; POSTSETTLEMENT PROCESSES; STOCK ENHANCEMENT; FLORIDA-KEYS; SETTLEMENT; MORTALITY AB Populations of benthic species that produce pelagic larvae are sustained through a complex interaction of factors, including larval supply, variable transport mechanisms, and a host of postsettlement processes that affect differential recruitment and abundance. We report distributional data for the larvae, juveniles, adults, and a time-averaged index of fishery yield (shell middens) of the economically important marine gastropod Strombus gigas (queen conch) in the Exuma Sound, Bahamas. All life history stages and the fishery yields were heterogeneously distributed around this semienclosed system, with higher densities of benthic stages in the northern part of the sound than in the south and east. Distribution of shell middens closely reflected abundance patterns of shallow-water juvenile aggregations and abundance of adults in depth-stratified surveys; therefore, midden distribution provided a good indicator of long-term productivity around the periphery of the sound. Although patterns of fishery productivity around the system were closely related to both juvenile and adult distributions, and density of newly-hatched larvae reflected the distribution of adults and shell middens, as would be expected, benthic stages and the fishery yields were completely decoupled from the abundance of settlement-stage larvae. When transplants of newly settled conch were made to four seagrass sites in the eastern Exuma Sound with characteristics typical of conch nurseries, low growth rates resulted in all but one location. All of these results suggest that conch abundance and distribution in Exuma Sound is determined in the benthos, either during settlement or in the first year of postsettlement life. Therefore, although larval supply has been shown to influence benthic recruitment on a small scale (i.e., size and location of juvenile aggregations), and juvenile populations will always depend upon a reliable source of competent larvae, high quality habitat plays an equally important role in the recruitment of this important fishery resource. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Highlands, NJ 07732 USA. Caribbean Marine Res Ctr, Vero Beach, FL 32963 USA. RP Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Highlands, NJ 07732 USA. NR 69 TC 7 Z9 7 U1 3 U2 17 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 1998 VL 17 IS 4 BP 955 EP 969 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 184RY UT WOS:000079628200008 ER PT J AU Nammack, M AF Nammack, M TI National marine fisheries service and the evolutionarily significant unit: Implications for management of freshwater mussels SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Gene Conservation held in conjunction with the 89th Annual Meeting of the National-Shellfisheries-Association CY APR 19-20, 1997 CL FT WALTON BEACH, FLORIDA SP Natl Shellfisheries Assoc DE genetics; conservation biology; management units; ESU; freshwater mussels; Pacific salmon; Endangered Species Act ID CONSERVATION; BIVALVIA AB The National Marine Fisheries Service (NMFS) published a policy on applying the definition of species under the Endangered Species Act (ESA) to Pacific salmon on November 20, 1991 (56 FR 58612). This policy states that a stock of Pacific salmon will be considered a distinct population, and hence a "species" under the ESA, if it represents an evolutionarily significant unit (ESU) of the biological species. NMFS has been implementing this policy for Pacific salmonids since it listed Snake River sockeye salmon in 1991. While genetic data play a central role in NMFS' ESU concept, they are not always available, and NMFS makes an effort to compile and evaluate available phenotypic, life history, and habitat information when conducting status reviews. Examples of how NMFS has used the ESU policy to delineate ESUs are provided. NMFS and the U.S. Fish and Wildlife Service (FWS) issued a joint policy on the recognition of distinct vertebrate population segments under the ESA on February 7, 1996. The concept of a distinct population segment can be applied to invertebrates in proactive efforts to protect species outside of the ESA. Genetic, phenotypic and life history data, and habitat characteristics can provide valuable information to managers of invertebrate species on which units to conserve in order to prevent ESA listings and recover species. C1 Natl Marine Fisheries Serv, Silver Spring, MD 20910 USA. RP Nammack, M (reprint author), Natl Marine Fisheries Serv, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 23 TC 3 Z9 3 U1 1 U2 4 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 1998 VL 17 IS 5 BP 1415 EP 1418 PG 4 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 187WN UT WOS:000079811400009 ER PT J AU Rubec, PJ Christensen, JD Arnold, WS Norris, H Steele, P Monaco, ME AF Rubec, PJ Christensen, JD Arnold, WS Norris, H Steele, P Monaco, ME TI GIS and modeling: Coupling habitats to Florida fisheries SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Spatial Data and Remote Sensing in Invertebrate Fisheries held in conjunction with the 89th Annual Meeting of the National-Shellfisheries-Association CY APR 19-20, 1997 CL FT WALTON BEACH, FLORIDA SP Natl Shellfisheries Assoc, Natl Environm Satellite Data & Informat Serv, US Army Corps Engineers Waterways Expt Stn DE fisheries habitat; habitat suitability modeling; essential fish habitat; geographic information systems; fisheries management AB To fill the need for information relating fishery species to habitat and anthropogenic effects on marine ecosystems: the Florida Marine Research Institute created the Marine Resources Geographic Information System (MRGIS). This comprehensive, coastwide database for research and management of fisheries provides spatial information for siting of clam aquaculture, hard-bottom mapping, and fishery exclusion zones. Fisheries-independent monitoring for Florida estuaries and habitat suitability modeling are also being used to create predicted distribution maps of fish and invertebrate species. Four case histories are summarized, designed to define relationships between habitat and marine fish and invertebrate species in Florida. C1 Florida Marine Res Inst, Florida Dept Environm Protect, St Petersburg, FL 33701 USA. US Dept Commerce, NOAA, NOS, Strateg Environm Assessments Div, Silver Spring, MD 20910 USA. RP Rubec, PJ (reprint author), Florida Marine Res Inst, Florida Dept Environm Protect, 100 8th Ave SE, St Petersburg, FL 33701 USA. NR 19 TC 6 Z9 7 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 1998 VL 17 IS 5 BP 1451 EP 1457 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 187WN UT WOS:000079811400016 ER PT J AU Tester, PA Stumpf, RP AF Tester, PA Stumpf, RP TI Phytoplankton blooms and remote sensing: What is the potential for early warning SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Spatial Data and Remote Sensing in Invertebrate Fisheries Held in Conjunction with the 89th Annual Meeting of the National-Shellfisheries-Association CY APR 19-20, 1997 CL FT WALTON BEACH, FL SP Natl Shellfisheries Assoc, Natl Environm Satellite Data & Informat Serv, US Army Corps Engineers Waterways Expt Stn DE plankton blooms; remote sensing; detection ID THEMATIC MAPPER; CHLOROPHYLL; ESTUARIES; ALGORITHM; TRANSPORT; IMAGERY; SURFACE AB Phytoplankton blooms are closely coupled to physical processes. Increased access to wind, sea surface temperature, and ocean color datasets aids in retrospective analyses of bloom events and provides vital linkages of physical and biological processes. From such analyses, conceptual models of bloom initiation, transport, maintenance, and dissipation may help identify the timing of bloom initiation and define environmental conditions conducive to growth. The advent of on-line, real-time environmental data, new ocean color sensors, and hyperspectral scanners may allow enough predictive capability so that harmful or toxic bloom conditions can be detected, research efforts focused, and reliable information made available, before effects of these blooms are manifest in near shore areas. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. US Geol Survey, Ctr Coastal Geol, St Petersburg, FL 33701 USA. RP Tester, PA (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. NR 28 TC 28 Z9 30 U1 0 U2 1 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 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 1998 VL 17 IS 5 BP 1469 EP 1471 PG 3 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 187WN UT WOS:000079811400019 ER PT J AU Brown, DW AF Brown, DW TI Habitat essential for sustainable fisheries SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Spatial Data and Remote Sensing in Invertebrate Fisheries held in conjunction with the 89th Annual Meeting of the National-Shellfisheries-Association CY APR 19-20, 1997 CL FT WALTON BEACH, FLORIDA SP Natl Shellfisheries Assoc, Natl Environm Satellite Data & Informat Serv, US Army Corps Engineers Waterways Expt Stn DE fishery management; habitat; Magnuson-Stevens Act; essential fish habitat AB With the passage of the Magnuson-Stevens Fisheries Conservation and Management Act in the fall of 1996, significant new tools exist in the United States to protect and conserve the habitat of marine, estuarine, and anadromous finfish as well as key populations of mollusks and crustaceans. Over the following 24 months, all Fisheries Management Councils are required to amend their fishery management plans (FMPs, covering over 300 species) to identify for each species the essential fish habitat that are those waters and substrate necessary for fish spawning, feeding, and,growth to maturity. Threats to habitat and steps necessary to ameliorate those threats must also be identified. C1 Natl Marine Fisheries Serv, Silver Spring, MD 20910 USA. RP Brown, DW (reprint author), Natl Marine Fisheries Serv, Silver Spring, MD 20910 USA. NR 7 TC 1 Z9 1 U1 1 U2 3 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 1998 VL 17 IS 5 BP 1481 EP 1482 PG 2 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 187WN UT WOS:000079811400022 ER PT J AU Tracey, GA Saade, E Stevens, B Selvitelli, P Scott, J AF Tracey, GA Saade, E Stevens, B Selvitelli, P Scott, J TI Laser line scan survey of crab habitats in Alaskan waters SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Spatial Data and Remote Sensing in Invertebrate Fisheries held in conjunction with the 89th Annual Meeting of the National-Shellfisheries-Association CY APR 19-20, 1997 CL FT WALTON BEACH, FLORIDA SP Natl Shellfisheries Assoc, Natl Environm Satellite Data & Informat Serv, US Army Corps Engineers Waterways Expt Stn DE laser; laser line scan; crab habitat; Alaska AB In 1996, the Alaska Fisheries Science Center/Alaska Department of Fish and Game, conducted a study to demonstrate the feasibility of using a laser line scan (LLS) system to detect physical and biological changes in bottom habitat attributable to trawling and to collect data for stock assessment. Surveys were conducted near Kodiak Island and in the Gulf of Alaska. Objectives were to: (1) compare LLS imagery with video and side scan over known bottom. (2) determine if new and old trawl tracks were detectable; (3) assess stocks of Tanner and red king crabs. The LLS excelled at imaging requirements and in identifying bottom fauna. C1 Sci Applicat Int Corp, Narragansett, RI 02882 USA. NOAA, Natl Marine Fisheries Serv, Kodiak, AK USA. RP Tracey, GA (reprint author), Sci Applicat Int Corp, Narragansett, RI 02882 USA. NR 4 TC 6 Z9 7 U1 0 U2 1 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 1998 VL 17 IS 5 BP 1483 EP 1486 PG 4 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 187WN UT WOS:000079811400023 ER PT J AU Stafford, KM Fox, CG Clark, DS AF Stafford, KM Fox, CG Clark, DS TI Long-range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID BALAENOPTERA-MUSCULUS; FUCA RIDGE; CALIFORNIA; ARRAY; JUAN AB Analysis of acoustic signals recorded from the U.S. Navy's SOund SUrveillance System (SOSUS) was used to detect and locate blue whale (Balaenoptera musculus) calls offshore in the northeast Pacific. The long, low-frequency components of these calls are characteristic of calls recorded in the presence of blue whales elsewhere in the world. Mean values for frequency and time characteristics from field-recorded blue whale calls were used to develop a simple matched filter for detecting such calls in noisy time series. The matched filter was applied to signals from three different SOSUS arrays off the coast of the Pacific Northwest to detect and associate individual calls from the same animal on the different arrays. A U.S. Navy maritime patrol aircraft was directed to an area where blue whale calls had been detected on SOSUS using these methods, and the presence of a vocalizing blue whale was confirmed at the site with field recordings from sonobuoys. [S0001-4966(98)01312-5]. C1 Oregon State Univ, Dept Fisheries & Wildlife, Newport, OR 97365 USA. NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA. USN, Command Control & Ocean Surveillance Ctr, San Diego, CA 95152 USA. RP Stafford, KM (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. NR 42 TC 81 Z9 87 U1 1 U2 17 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 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1998 VL 104 IS 6 BP 3616 EP 3625 DI 10.1121/1.423944 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 145JM UT WOS:000077367500053 PM 9857519 ER PT J AU Bergman, JW Hendon, HH AF Bergman, JW Hendon, HH TI Calculating monthly radiative fluxes and heating rates from monthly cloud observations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; SURFACE SOLAR IRRADIANCE; COMMUNITY CLIMATE MODEL; DIURNAL-VARIATIONS; SEASONAL-VARIATION; BUDGET EXPERIMENT; C1 DATA; ISCCP; EARTH; VARIABILITY AB The radiative transfer model from NCAR's general circulation model CCM3 is modified to calculate monthly radiative fluxes and heating rates from monthly observations of cloud properties from the International Satellite Cloud Climatology Project and temperature and humidity from ECMWF analysis. The calculation resolves the three-dimensional structure of monthly to interannual variations of radiative heating and is efficient enough to allow a wide range of sensitivity tests. Two modifications to the radiative transfer model improve the calculation of shortwave (SW) fluxes in a cloudy atmosphere. The first replaces an existing nonphysical parameterization of partially cloudy skies with a physically motivated one that increases substantially the accuracy of calculated SW fluxes while increasing the computational time of the calculation by only 10%. The second modification allows the specification of generalized cloud overlap properties. With these modifications, radiative fluxes are calculated from observed atmospheric properties without any tuning to observed fluxes. Based on a comparison with top-of-the-atmosphere (TOA) fluxes observed in the Earth Radiation Budget Experiment, calculated SW and longwave (LW) fluxes at TOA have errors of less than 10 W m(-2) at 2.5 degrees horizontal resolution, with smaller errors over ocean than over land. Errors in calculated surface fluxes are 10-20 W m(-2) based on sensitivity tests and comparisons to surface fluxes from the GEWEX Surface Radiation Budget. In contrast, TOA and surface fluxes from the NCEP/NCAR reanalysis data, which rely on cloud properties from a general circulation model, have errors larger than 30 W m(-2). Errors in the calculated fluxes result primarily from uncertainties in the observed cloud properties and specified surface albedo, with somewhat smaller errors resulting from unobserved aspects of the vertical distribution of clouds. Errors introduced into the calculation by using monthly observations and neglecting high-frequency variations are small relative to other sources of error. Substantial uncertainty is found in many details of the vertical structure of cloud radiative forcing, which underscores the importance of performing a wide variety of sensitivity calculations in order to understand the impact of clouds on radiative heating. However, certain general features of the calculated vertical structure of cloud radiative forcing in the atmosphere are robust. Deep vertical cloud distributions at locations of active tropical convection result in deep cloud radiative heating, whereas shallow cloud distributions in the subtropics result in low-level cloud radiative cooling there. Under all conditions, SW cloud radiative forcing is systematically of opposite sign to LW cloud radiative forcing, which reduces the impact of LW cloud radiative forcing. C1 Univ Colorado, CDC CB 449, CIRES, NOAA, Boulder, CO 80309 USA. RP Bergman, JW (reprint author), Univ Colorado, CDC CB 449, CIRES, NOAA, Boulder, CO 80309 USA. NR 51 TC 29 Z9 30 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1998 VL 55 IS 23 BP 3471 EP 3491 DI 10.1175/1520-0469(1998)055<3471:CMRFAH>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 145NH UT WOS:000077377500006 ER PT J AU Sanford, NA Aust, JA AF Sanford, NA Aust, JA TI Nonlinear optical characterization of LiNbO3. I. Theoretical analysis of Maker fringe patterns for x-cut wafers SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA Rumanian DT Article ID LITHIUM-NIOBATE; CRYSTALS AB Marker fringe analysis was adapted to x-cut LiNbO3 wafers to examine variations in birefringence, thickness, and photoelastic strain. The pump beam was polarized parallel to the crystalline gamma axis and produced e- and o-polarized Maker fringes, owing to d(31) and d(22), respectively, by rotation of the sample about they y axis. Fitting our model to the o-polarized data enabled computation of the sample thickness to an uncertainty of approximately +/-0.01 mu m. The accuracy was limited by an implicit +/-2 x 10(-4) uncertainty in n(o) that exists in the commonly used Sellmeier equation of G. J. Edwards and M. Lawrence, Opt. Quantum Electron. 16, 373 (1984). For a pump wavelength lambda(p) = 1064 nm, fitting the model to the e-polarized fringes revealed that n(e) at 532 nm deviated from the Sellmeier result by typically -1.58 x 10-4. The uniformity of n(e) over a wafer 10 cm in diameter was approximately +/-4 x 10(-5). This result is consistent with that expected from compositional variations. Our model included multiple passes of the pump and second-harmonic waves. The effects of photoelastic strain in producing perturbations and mixing of the e- and a-polarized fringes was investigated. This was restricted to two experimentally motivated cases that suggested that strains produce rotations of the optic axis by typically +/-0.05 degrees about the x axis and y axis with the former assigned to an indeterminant combination of S-1, S-2, and S-4 and the latter to an indeterminant combination of S-5 and S-6. In both cases the magnitude of the collective strains is of the order of 10(-4). The birefringence variations that are due to strain are of the same magnitude as those expected from compositional variations. The formalism developed here is used in the subsequent mapping study of x-cut wafers. (C) 1998 Optical Society of America [S0740-3224(98)00412-3] OCIS codes: 160.3730, 160.4330, 190.1900, 190.4400. C1 Natl Inst Stand & Technol, Optoelect Div 815, Boulder, CO 80303 USA. RP Sanford, NA (reprint author), Natl Inst Stand & Technol, Optoelect Div 815, 325 Broadway, Boulder, CO 80303 USA. EM sanford@boulder.nist.gov NR 26 TC 9 Z9 9 U1 0 U2 2 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 1998 VL 15 IS 12 BP 2885 EP 2909 DI 10.1364/JOSAB.15.002885 PG 25 WC Optics SC Optics GA 147HC UT WOS:000077482400010 ER PT J AU Wallace, JS Ilavsky, J AF Wallace, JS Ilavsky, J TI Elastic modulus measurements in plasma sprayed deposits SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE elastic properties; instrumented indentation; plasma spray; small-angle neutron scattering; YSZ ID COATINGS AB A commercial hardness indenter has been modified to record load displacement as a spherical ball is elastically loaded onto the surface of the material to be measured. The resulting data are used to calculate the elastic modulus. This technique has been used to characterize the elastic modulus of zirconium oxide-8% yttrium oxide plasma sprayed deposits. Moduli were measured both on the cross section and on the plan section, and the differences were correlated with the microstructure. Since relatively small areas of the material were sampled by the indenter, local mapping of elastic modulus variations on the size scale of the microstructure was possible. A periodic variation in modulus with position in the cross section was found on a length scale that corresponded to the average plasma spray pass thickness, Elastic modulus variations also have been found on a macro scale through the thickness of freestanding plasma sprayed deposits. These large scale variations were probably a result of self annealing during the production of these thick samples. Finally, significant increases in elastic modulus have been found in samples annealed for a total of 2.5 h at 1100 degrees C. These changes have been correlated with small angle neutron scattering measurements of void surface area. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Wallace, JS (reprint author), Acad Sci Czech Republ, Inst Plasma Phys, Prague, Czech Republic. RI Ilavsky, Jan/D-4521-2013 OI Ilavsky, Jan/0000-0003-1982-8900 NR 12 TC 50 Z9 51 U1 0 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD DEC PY 1998 VL 7 IS 4 BP 521 EP 526 DI 10.1361/105996398770350747 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA 147UZ UT WOS:000077516700009 ER PT J AU Gardner, WS Cavaletto, JF Bootsma, HA Lavrentyev, PJ Troncone, F AF Gardner, WS Cavaletto, JF Bootsma, HA Lavrentyev, PJ Troncone, F TI Nitrogen cycling rates and light effects in tropical Lake Maracaibo, Venezuela SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MISSISSIPPI RIVER PLUME; ULTRAVIOLET-B RADIATION; DIFFERENT HUMIC CONTENT; DILUTION TECHNIQUE; MEDITERRANEAN-SEA; COASTAL WATERS; AMMONIUM; PHYTOPLANKTON; REGENERATION; MARINE AB Isotope dilution experiments with (NH4+)-N-15 were conducted in Lake Maracaibo, Venezuela, to examine potential N turnover rates and light effects and to examine the hypothesis that nutrient dynamics are biologically driven in this tropical, hypereutrophic lake. Ammonium and nitrate concentrations were both <1 mu M as compared to particulate N concentrations of 9-29 mu M N. Chlorophyll (Chl) levels ranged from 2.5 to 22 mu g liter-l. Numbers and biomass of bacteria ranged from 1.0 to 9.1 x 10(6) cells ml(-1) and 45 to 138 mu g C liter(-1) and those of heterotrophic nanofragellates (HNAN) ranged from 0.5 to 3.5 x 10(3) cells ml(-1) and 2.3 to 17.5 mu g C liter(-1), respectively. Highest Chi concentration and microbial abundance occurred in a region affected by sewage discharge from the city of Maracaibo. Potential ammonium uptake rates in near-surface waters ranged from about 1 mu M h(-1) to 8 mu M h(-1). Chl-specific uptake rates were highest in central regions that were dominated by chroococcoid cyanobacteria. Ammonium regeneration rates ranged from near detection to 2 mu M h(-1) and correlated significantly with the ratio of HNAN to bacterial biomass, likely reflecting the degree of bacterivory. The high ratio of potential turnover rates to ambient ammonium concentrations suggests that internal recycling is a major nutrient supply process in the lake. Incubation bottle characteristics (e.g., Light intensity, spectral quality, or possibly headspace differences) apparently affected potential uptake rates, which were relatively low in polystyrene bottles and in quartz tubes. Uptake rates were lower in screened polystyrene bottles than in screened polypropylene syringes, with different spectral characteristics, even though total light attenuation was similar (45% vs. 53%). C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. ICLAM, Maracaibo, Venezuela. RP Gardner, WS (reprint author), Univ Texas, Inst Marine Sci, 750 Channelview Dr, Port Aransas, TX 78373 USA. NR 57 TC 29 Z9 30 U1 0 U2 4 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 1998 VL 43 IS 8 BP 1814 EP 1825 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 148YZ UT WOS:000077563500005 ER PT J AU Ruzette, AVG Banerjee, P Mayes, AM Pollard, M Russell, TP Jerome, R Slawecki, T Hjelm, R Thiyagarajan, P AF Ruzette, AVG Banerjee, P Mayes, AM Pollard, M Russell, TP Jerome, R Slawecki, T Hjelm, R Thiyagarajan, P TI Phase behavior of diblock copolymers between styrene and n-alkyl methacrylates SO MACROMOLECULES LA English DT Article ID CRITICAL ORDERING TRANSITION; PRESSURE-VOLUME-TEMPERATURE; ANGLE NEUTRON-SCATTERING; POLYMER BLENDS; INTERACTION PARAMETER; POLY(METHYL METHACRYLATE); MICROPHASE SEPARATION; DISORDER TRANSITION; POLYSTYRENE; DEPENDENCE AB In contrast to most diblock copolymers which exhibit the classical upper critical ordering transition (UCOT), polystyrene-b-poly n-butyl methacrylate-PS-b-PBMA-has been shown to undergo ordering upon heating through a lower critical ordering transition(LCOT). Here we report the phase behavior of a family of diblock copolymers formed from styrene and a homologous series of n-alkyl methacrylates, as determined by combined dynamic rheological testing and small-angle neutron scattering (SANS). It is shown that the shortest side chain methacrylates, with the exception of methyl methacrylate, exhibit the LCOT, while for side chains longer than n-butyl, the copolymers exhibit the classical UCOT behavior. Combined group contribution/lattice fluid model calculations of the solubility parameter and specific volume of the corresponding homopolymers qualitatively support these observations. The same calculations were further employed to molecularly design LCOT behavior into a new diblock material consisting of styrene and a random copolymer of methyl and lauryl methacrylate, denoted PS-b-P(MMA-r-LMA). The success of this approach suggests a simple semiquantitative method for predicting and designing the phase behavior of weakly interacting polymer pairs. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. Univ Liege, Ctr Educ & Res Macromol, B-4000 Cointe Ougree, Belgium. NIST, Cold Neutron Res Facil, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87544 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RI Lujan Center, LANL/G-4896-2012 NR 35 TC 92 Z9 92 U1 2 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD DEC 1 PY 1998 VL 31 IS 24 BP 8509 EP 8516 DI 10.1021/ma981055c PG 8 WC Polymer Science SC Polymer Science GA 150GW UT WOS:000077657000009 ER PT J AU Ikkai, F Iritani, O Shibayama, M Han, CC AF Ikkai, F Iritani, O Shibayama, M Han, CC TI Effect of degree of cross-linking on spatial inhomogeneity in charged gels. 3. Ionization effect SO MACROMOLECULES LA English DT Article ID POLY(N-ISOPROPYLACRYLAMIDE-CO-ACRYLIC ACID) GELS; DYNAMIC LIGHT-SCATTERING; POLY(VINYL ALCOHOL) GELS; POLYACRYLAMIDE HYDROGELS; STATISTICAL PHYSICS; DENSITY-DEPENDENCE; POLYMER GELS; BORATE IONS; FLUCTUATIONS AB The effect of degree of ionization, f, on the spatial inhomogeneities in weakly charged polymer gels has been investigated by light scattering (LS) and small-angle neutron scattering. An anomalous cross-link density (CD) dependence of the scattered intensity, I(q), was observed in a poor solvent (above an inversion temperature, T-inv), where q is the scattering vector. That is, a gel became more homogeneous with increasing CD in a poor solvent (above T-inv) though it became more heterogeneous with increasing CD in a good solvent (below T-inv). LS data indicated the following three features of the gels: (1) an increase of T-inv, with increasing f (2) a decrease of the critical degree of polymerization between cross-linking points, N-c, with increasing f, where N-c is the critical value of N at which I(q) diverges with decreasing N (similar to 1/CD), and (3) a decrease of I(q) with f. The influence of f on the anomaly as well as on the microscopic and macroscopic phase separation was discussed in terms of the Rabin-Panyukov (RP) theory proposed for weakly charged gels. C1 Kyoto Inst Technol, Dept Polymer Sci & Engn, Sakyo Ku, Kyoto 6068585, Japan. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Shibayama, M (reprint author), Kyoto Inst Technol, Dept Polymer Sci & Engn, Sakyo Ku, Kyoto 6068585, Japan. RI Shibayama, Mitsuhiro/E-1646-2015 OI Shibayama, Mitsuhiro/0000-0002-8683-5070 NR 22 TC 20 Z9 20 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 1 PY 1998 VL 31 IS 24 BP 8526 EP 8530 DI 10.1021/ma980962e PG 5 WC Polymer Science SC Polymer Science GA 150GW UT WOS:000077657000012 ER PT J AU Millero, FJ Dickson, AG Eischeid, G Goyet, C Guenther, P Johnson, KM Key, RM Lee, K Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Lewis, E Winn, CD AF Millero, FJ Dickson, AG Eischeid, G Goyet, C Guenther, P Johnson, KM Key, RM Lee, K Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Lewis, E Winn, CD TI Assessment of the quality of the shipboard measurements of total alkalinity on the WOCE Hydrographic Program Indian Ocean CO2 survey cruises 1994-1996 SO MARINE CHEMISTRY LA English DT Article DE alkalinity; WOCE Hydrographic Program; CO2 ID SEA-WATER; SEAWATER; ACID; THERMODYNAMICS; DISSOCIATION; 273.15-K; 318.15-K; CARBON; MEDIA AB In 1995, we participated in a number of WOCE Hydrographic Program cruises in the Indian Ocean as part of the Joint Global Ocean flux Study (JGOFS) CO, Survey sponsored by the Department of Energy (DOE). Two titration systems were used throughout this study to determine the pH, total alkalinity (TA) and total inorganic carbon dioxide (TCO2) of the samples collected during these cruises. The performance of these systems was monitored by making closed cell titration measurements on Certified Reference Materials (CRMs). A total of 962 titrations were made on six batches of CRMs during the cruises. The reproducibility calculated from these titrations was +/-0.007 in pH, +/-4.2 mu mol kg(-1) in TA, and +/-4.1 mu mol kg(-1) in TCO2. The at-sea measurements on the CRMs were in reasonable agreement with laboratory measurements made on the same batches. These results demonstrate that the CRMs can be used as a reference standard for TA and to monitor the performance of titration systems at sea. Measurements made on the various legs of the cruise agreed to within 6 mu mol kg(-1) at the 15 crossover points. The overall mean and standard deviation of the differences at all the crossovers are 2.1 +/- 2.1 mu mol kg(-1). These crossover results are quite consistent with the overall reproducibility of the CRM analyses for TA (+/-4 mu mol kg(-1)) over the duration of the entire survey, The TA results for the Indian Ocean cruises provide a reliable data set that when combined with TCO2 data can completely characterize the carbonate system. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA 92093 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. RP Millero, FJ (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RI Lee, Kitack/G-7184-2015 NR 20 TC 19 Z9 21 U1 5 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD DEC PY 1998 VL 63 IS 1-2 BP 9 EP 20 DI 10.1016/S0304-4203(98)00043-7 PG 12 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 214ZP UT WOS:000081357700002 ER PT J AU Williamson, J Coursey, BM DeWerd, LA Hanson, WF Nath, R AF Williamson, J Coursey, BM DeWerd, LA Hanson, WF Nath, R TI Dosimetric prerequisites for routine clinical use of new low energy photon interstitial brachytherapy sources SO MEDICAL PHYSICS LA English DT Article C1 Washington Univ, Sch Med, Edward Mallinckrodt Inst Radiol, St Louis, MO 63110 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Wisconsin, Accredited Dosimetry & Calibrat Lab, Madison, WI 53706 USA. Univ Texas, MD Anderson Cancer Ctr, Radiol Phys Ctr, Houston, TX 77030 USA. Yale Univ, Dept Therapeut Radiol, New Haven, CT 06520 USA. RP Williamson, J (reprint author), Washington Univ, Sch Med, Edward Mallinckrodt Inst Radiol, St Louis, MO 63110 USA. NR 1 TC 92 Z9 95 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 1998 VL 25 IS 12 BP 2269 EP 2270 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 149YX UT WOS:000077635700004 PM 9874817 ER PT J AU Ogi, H Suzuki, N Hirao, M AF Ogi, H Suzuki, N Hirao, M TI Noncontact ultrasonic spectroscopy on deforming polycrystalline copper: Dislocation damping and acoustoelasticity SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ELECTROMAGNETIC ACOUSTIC-RESONANCE; ATTENUATION AB Electromagnetic acoustic resonance (EMAR) is developed for the continuous measurement of the bulk-wave attenuation and phase velocities in a metal during a deformation process. The EMAR enables one to perform the noncontact measurement with extremely high sensitivity, in which the electromagnetic acoustic transducer (EMAT) generates and detects the bulk waves without any coupling material. The attenuation and velocity responses to the uniaxial stress were continuously recorded for 99.99 wt pet pure polycrystalline copper annealed at 200 degrees C for 1 hour before loading. We separated the velocity change due to the acoustoelastic effect from the contribution of the dislocation movement responding to the ultrasonic waves, and determined the pure third-order elastic constants. The shear wave showed much larger sensitivity to the dislocation mobility than the longitudinal wave. The discontinuous change in the incremental rate of the shear wave attenuation was observed in the elastic region, which was interpreted as the onset of the microscopic yielding. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Osaka Univ, Grad Sch Engn Sci, Osaka 5608531, Japan. RP Ogi, H (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI 苏, 日亮/D-4386-2009 NR 18 TC 16 Z9 17 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD DEC PY 1998 VL 29 IS 12 BP 2987 EP 2993 DI 10.1007/s11661-998-0206-y PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 152HU UT WOS:000077771700013 ER PT J AU Peck-Miller, KA Myers, M Collier, TK Stein, JE AF Peck-Miller, KA Myers, M Collier, TK Stein, JE TI Complete cDNA sequence of the Ki-ras proto-oncogene in the liver of wild English sole (Pleuronectes vetulus) and mutation analysis of hepatic neoplasms and other toxicopathic liver lesions SO MOLECULAR CARCINOGENESIS LA English DT Article DE animal; molecular sequence data; ras genes; liver neoplasms; mutation ID RIVULUS-OCELLATUS-MARMORATUS; MEDAKA ORYZIAS-LATIPES; PAROPHRYS-VETULUS; RAINBOW-TROUT; MESSENGER-RNA; PUGET-SOUND; PROTOONCOGENE ACTIVATION; CONTAMINANT EXPOSURE; WINTER FLOUNDER; CHEMICAL CONTAMINANTS AB A complete copy of Ki-ras b cDNA from English sole (Pleuronectes vetulus), a benthic marine flatfish, was cloned and sequenced. The percent identity between the predicted amino acid sequence of English sole and human Ki-ras b was 97%, whereas the percent identity between the English sole gene and rainbow trout or Rivulus Ki-ras b was 98%. Areas of amino-acid sequence conservation included codons 12, 13, and 61, the positions in which mutations are observed in ras cellular oncogenes in other species. The 5' untranslated region (UTR), consisting of 217 nt, was not highly GC rich but contained four ATG start codons upstream of the major open reading frame. The 3' UTR, containing 26 nt, was AU rich. Analysis of Ki-ras mutations was performed on a variety of necrotic, preneoplastic, and neoplastic lesions in livers from 13 English sole collected from contaminated waterways in Puget Sound, WA. Despite reports of Ki-ras mutations in hepatic tumors from other fish, no mutations in codons 12, 13, or 61 were found in hepatic lesions from English sole by direct DNA sequencing of polymerase chain reaction-amplified genomic DNA. Although mutations could exist at levels below the detection limits of this analysis, the results suggest that Ki-ras has a role in river carcinogenesis that varies according to the fish species or carcinogen. Furthermore, future studies of the etiology of chemically induced cancer in feral English sole should consider mutations in other cancer-related genes, such asp53, Ha-ras, and N-ras. (C) 1998 Wiley-Liss. Inc. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Peck-Miller, KA (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 60 TC 9 Z9 10 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0899-1987 J9 MOL CARCINOGEN JI Mol. Carcinog. PD DEC PY 1998 VL 23 IS 4 BP 207 EP 216 DI 10.1002/(SICI)1098-2744(199812)23:4<207::AID-MC3>3.0.CO;2-Y PG 10 WC Biochemistry & Molecular Biology; Oncology SC Biochemistry & Molecular Biology; Oncology GA 150AP UT WOS:000077640500003 PM 9869449 ER PT J AU Rhodes, LD Nilsson, WB Strom, MS AF Rhodes, LD Nilsson, WB Strom, MS TI Sensitive detection of Renibacterium salmoninarum in whole fry, blood, and other tissues of Pacific salmon by reverse transcription polymerase chain reaction SO MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY LA English DT Article ID TROUT ONCORHYNCHUS-MYKISS; BACTERIAL KIDNEY-DISEASE; 16S RIBOSOMAL-RNA; FISH PATHOGEN; PCR; IDENTIFICATION; DNA; TSHAWYTSCHA; FLUID; ELISA AB A sensitive, reproducible assay for detecting Renibacterium salmoninarum in a variety of tissues, including blood, has been developed. This assay, based on reverse transcription-polymerase chain reaction (RT-PCR) of 16S ribosomal RNA, exhibited sensitivity to less than or equal to 10 cells per milligram of tissue by ethidium bromide detection, and this sensitivity was increased 10-fold by Southern blotting. There was a strong association (p <.001) between blood and ovarian fluid for the presence of bacteria in spawning salmon, and in 17.9% of the infected fish, bacteria were detected in blood but not in ovarian fluid. The ability to analyze multiple tissues, the reproducibility, and sensitivity of 16S RT-PCR make it a useful tool for both research and husbandry applications. C1 NW Fisheries Sci Ctr, REUT Div, Seattle, WA 98112 USA. RP Strom, MS (reprint author), NW Fisheries Sci Ctr, REUT Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. OI Rhodes, Linda/0000-0003-4995-9426 NR 20 TC 12 Z9 12 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1053-6426 J9 MOL MAR BIOL BIOTECH JI Mol. Mar. Biol. Biotechnol. PD DEC PY 1998 VL 7 IS 4 BP 270 EP 279 PG 10 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 151PW UT WOS:000077730500005 PM 9892717 ER PT J AU Willoughby, HE AF Willoughby, HE TI Tropical cyclone eye thermodynamics SO MONTHLY WEATHER REVIEW LA English DT Article ID PACIFIC HURRICANE SEASON; EVOLUTION; DYNAMICS AB In intense tropical cyclones, sea level pressures at the center are 50-100 hPa lower than outside the vortex, but only 10-30 hPa of the total pressure fall occurs inside the eye between the eyewall and the center. Warming by dry subsidence accounts for this fraction of the total hydrostatic pressure fall. Convection in the eyewall causes the warming by doing work on the eye to force the thermally indirect subsidence. Soundings inside hurricane eyes show warm and dry air aloft, separated by an inversion from cloudy air below. Dewpoint depressions at the inversion level, typically 850-500 hPa, are 10-30 K rather than the similar to 100 K that would occur if the air descended from tropopause level without dilution by the surrounding cloud. The observed temperature and dewpoint distribution above the inversion can, however, be derived by similar to 100 hPa of undilute dry subsidence from an initial sounding that is somewhat more stable than a moist adiabat. It is hypothesized that the air above the inversion has remained in the eye since it was enclosed when the eyewall formed and that it has subsided at most a few kilometers. The cause of the subsidence is the enclosed air's being drawn downward toward the inversion level as the air below it flows outward into the eyewall. Shrinkage of the eye's volume is more than adequate to supply the volume lost as dry air is incorporated into the eyewall or converted to moist air by turbulent mixing across the eye boundary. The moist air below the inversion is in thermodynamic contact with the sea surface. Its moisture derives from evaporation of seawater inside the eye, frictional inflow of moist air under the eyewall, and from moist downdrafts induced as condensate mixes into the eye. The moist air's residence time in the eye is much shorter than that of the dry air above the inversion. The height of the inversion is determined by the balance between evaporation, inflow, and inward mixing on one hand and loss to the eyewall updrafts on the other. C1 NOAA, AOML, Hurricane Res Div, Miami, FL 33143 USA. RP Willoughby, HE (reprint author), NOAA, AOML, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33143 USA. NR 34 TC 88 Z9 90 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1998 VL 126 IS 12 BP 3053 EP 3067 DI 10.1175/1520-0493(1998)126<3053:TCET>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300001 ER PT J AU Mayfield, M Rappaport, EN AF Mayfield, M Rappaport, EN TI Eastern North Pacific hurricane season of 1996 SO MONTHLY WEATHER REVIEW LA English DT Article AB The National Hurricane Center (a component of the Tropical Prediction Center) tracked nine tropical storms, five of which became hurricanes, during the 1996 eastern North Pacific hurricane season. Five tropical storms or hurricanes made landfall in Mexico. An overview of the 1996 hurricane season is presented. C1 NOAA, NWS, NHC, Trop Predict Ctr, Miami, FL 33165 USA. RP Mayfield, M (reprint author), NOAA, NWS, NHC, Trop Predict Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 3 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1998 VL 126 IS 12 BP 3068 EP 3076 DI 10.1175/1520-0493(1998)126<3068:ENPHSO>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300002 ER PT J AU Nogues-Paegle, J Mo, KTC Paegle, J AF Nogues-Paegle, J Mo, KTC Paegle, J TI Predictability of the NCEP-NCAR reanalysis model during austral summer SO MONTHLY WEATHER REVIEW LA English DT Article ID SURFACE TEMPERATURE ANOMALIES; TROPICAL SOUTH-AMERICA; CIRCULATION; IMPACT; ATMOSPHERE; TOPOGRAPHY; FORECASTS; CLIMATE; FLOW AB Ten years of forecasts during Northern Hemisphere winter produced by the NCEP-NCAR reanalysis project are analyzed and their errors are documented with a focus on forecasts over South America. Previous studies have documented a seesaw pattern in the South Atlantic Convergence Zone (SACZ). Events associated with a strong SACZ are periods when the subtropical plains of South America exhibit precipitation deficits. When the SACZ weakens, precipitation in the plains is abundant. The forecast errors during these periods are examined separately. An error climatology is also obtained based on all available forecasts for January and February. It is found that cases with weak SACZ are characterized by relatively smaller forecast errors in the Americas and neighboring oceans during the first three days than are strong SACZ cases. The error growth for these weak SACZ cases is larger and the forecast errors exceed those in the strong SACZ cases after about 5 days. Upper-tropospheric divergence is systematically underpredicted over tropical and subtropical South America in the 117 studied forecasts, and it is overpredicted over the Caribbean. Similar features are also found in the 6-h forecast precipitation verified against global precipitation index estimates. The 3-8-day model forecasts retain some characteristics of the weak and strong SACZ events, but underpredict their amplitudes. Eight-day predicted upper-tropospheric zonal winds have substantial errors over North America. Integrations with a simple global numerical model suggest that the predicted wind error over North America is due to latent heating errors associated with precipitation forecast errors located nearby. Central and western Pacific errors do not appear to be as important for wind forecast errors in this region. Weak SACZ events are characterized by stronger low-level jets and more poleward moisture transport east of the Andes than are strong SACZ events in the NCEP-NCAR reanalysis. This distinction is substantially weakened in the 8-day forecasts. Integrations with a global model suggest that inadequate simulation of the distribution of latent heating and of radiative heating may have contributed to the inability of the NCEP forecast model to adequately distinguish low-level flow structures during positive and negative events. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. NOAA, Natl Weather Serv, NCEP, Washington, DC 20233 USA. RP Univ Utah, Dept Meteorol, 819 Wm C Browning Bldg, Salt Lake City, UT 84112 USA. EM jnpaegle@icicle.met.utah.edu NR 31 TC 21 Z9 21 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1998 VL 126 IS 12 BP 3135 EP 3152 DI 10.1175/1520-0493(1998)126<3135:POTNNR>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300007 ER PT J AU Lewis, SA LeMone, MA Jorgensen, DP AF Lewis, SA LeMone, MA Jorgensen, DP TI Evolution and dynamics of a late-stage squall line that occurred on 20 February 1993 during TOGA COARE SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; VERTICAL VELOCITY; MOMENTUM; SHEAR; GATE; MASS; ENVIRONMENTS; SIMULATIONS; BUOYANCY; MODELS AB Airborne Doppler and flight-level data are used to document the structure and evolution of portions of a late-stage horseshoe-shaped squall line system and its effect on vertical momentum and mass transports. This system, which occurred on 20 February 1993 during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, was similar to many previously studied, but had some unique features. First, a slow-moving transverse band, which formed the southern leg of the horseshoe, drew most of its low-level updraft air from the squall-line stratiform region on its north side rather than the "environment" to the south. Second, a long-lived cell with many properties similar to a midlatitude supercell, formed 150 km to the rear of the squall line. This cell was tracked for 4 h, as it propagated into and then through the cold pool, and finally dissipated as it encountered the convection forming the northern edge of the horseshoe. Finally, as the squall line was dissipating, a new convective band formed well to its rear. The transverse band and the long-lived cell are discussed in this paper. Quadruple-Doppler radar data, made possible by tightly coordinated flights by the two NOAA P3s, are used to document the flow with unprecedented accuracy. At lower levels, the transverse band flow structure is that of a two-dimensional convective band feeding on its north side, with vertical fluxes of mass and horizontal momentum a good match to the predictions of the Moncrieff archetype model. At upper levels, the transverse band flow is strongly influenced by the squall line, whose westward-tilting updraft leads-to much larger Vertical velocities than predicted by the model. The long-lived cell, though weak, has supercell-like properties in addition to its longevity, including an updraft rotating in the sense expected from the environmental hodograph and an origin in an environment whose Richardson number falls within the Weisman-Klemp "supercell" regime. C1 NOAA, Natl Severe Storms Lab, N C MRD, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Lewis, SA (reprint author), NOAA, Natl Severe Storms Lab, N C MRD, 325 Broadway, Boulder, CO 80303 USA. NR 48 TC 16 Z9 16 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1998 VL 126 IS 12 BP 3189 EP 3212 DI 10.1175/1520-0493(1998)126<3189:EADOAL>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300010 ER PT J AU Pacanowski, RC Gnanadesikan, A AF Pacanowski, RC Gnanadesikan, A TI Transient response in a z-level ocean model that resolves topography with partial cells SO MONTHLY WEATHER REVIEW LA English DT Article ID COORDINATE; REPRESENTATION AB Ocean simulations are in part determined by topographic waves with speeds and spatial scales dependent on bottom slope. By their very nature, discrete z-level ocean models have problems accurately representing bottom topography when slopes are less than the grid cell aspect ratio Delta z/Delta x. In such regions, the dispersion relation for topographic waves is inaccurate. However, bottom topography can be accurately represented in discrete z-level models by allowing bottom-most grid cells to be partially filled with land. Consequently, gently sloping bottom topography is resolved on the scale of horizontal grid resolution and the dispersion relation for topographic waves is accurately approximated. In contrast to the standard approach using full cells, partial cells imply that all grid points within a vertical level are not necessarily at the same depth and problems arise with pressure gradient errors and the spurious diapycnal diffusion. However, both problems have been effectively dealt with. Differences in flow fields between simulations with full cells and partial cells can be significant, and simulations with partial cells are more robust than with full cells. Partial cells provide a superior representation of topographic waves when compared to the standard method employing full cells. C1 Princeton Univ, NOAA, GFDL, AOS Program, Princeton, NJ 08540 USA. RP Pacanowski, RC (reprint author), Princeton Univ, NOAA, GFDL, AOS Program, POB CN710, Princeton, NJ 08540 USA. RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 20 TC 117 Z9 117 U1 0 U2 4 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 1998 VL 126 IS 12 BP 3248 EP 3270 DI 10.1175/1520-0493(1998)126<3248:TRIAZL>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300013 ER PT J AU Whitaker, JS Loughe, AF AF Whitaker, JS Loughe, AF TI The relationship between ensemble spread and ensemble mean skill SO MONTHLY WEATHER REVIEW LA English DT Article ID FORECAST SKILL; PREDICTION; NMC; LYAPUNOV; VECTORS; HEIGHT; ERROR; FIELD AB Statistical considerations suggest that 1) even for a perfect ensemble tone in which all sources of forecast error are sampled correctly) there need not be a high correlation between spread and skill, 2) the correlation between spread and skill should be larger where the day-to-day variability of spread is large, and 3) the spread is likely to be most useful as a predictor of skill when it is "extreme," that is, when it is either very large or very small compared to its climatological mean value. The authors investigate the relationship between spread and skill in an operational setting by analyzing ensemble predictions produced by the National Centers for Environmental Prediction. The geographical dependence of the spread-skill relationship is found to be related to the geographical dependence of day-to-day variability of spread. Dynamical mechanisms for spread variability are investigated using a linear quasigeostrophic model. Problems associated with the sample size needed to define what constitutes an extreme value of spread at a given location are discussed. C1 Univ Colorado, NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80309 USA. RP Whitaker, JS (reprint author), Univ Colorado, NOAA, CIRES, Climate Diagnost Ctr, Campus Box 449, Boulder, CO 80309 USA. EM jsw@cdc.noaa.gov NR 21 TC 96 Z9 99 U1 0 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 1998 VL 126 IS 12 BP 3292 EP 3302 DI 10.1175/1520-0493(1998)126<3292:TRBESA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300015 ER PT J AU Pitman, RL Chivers, SJ AF Pitman, RL Chivers, SJ TI Terror in black and white - Killer whales devastate a pod of sperm whales in the Pacific off the coast of California SO NATURAL HISTORY LA English DT Article C1 NOAA, Boulder, CO 80303 USA. SW Fisheries Sci Ctr, La Jolla, CA USA. RP Pitman, RL (reprint author), NOAA, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 2 U2 4 PU AMER MUSEUM NAT HISTORY PI NEW YORK PA ATTN: LIBRARY SERIALS UNIT CENTRAL PK WEST AT 79TH ST, NEW YORK, NY 10024-5192 USA SN 0028-0712 J9 NAT HIST JI Nat. Hist. PD DEC-JAN PY 1998 VL 107 IS 10 BP 26 EP 29 PG 4 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 149AV UT WOS:000077584500009 ER PT J AU Senturker, S van der Kemp, PA You, HJ Doetsch, PW Dizdaroglu, M Boiteux, S AF Senturker, S van der Kemp, PA You, HJ Doetsch, PW Dizdaroglu, M Boiteux, S TI Substrate specificities of the Ntg1 and Ntg2 proteins of Saccharomyces cerevisiae for oxidized DNA bases are not identical SO NUCLEIC ACIDS RESEARCH LA English DT Article ID COLI ENDONUCLEASE-III; ESCHERICHIA-COLI; FPG PROTEIN; BETA-ELIMINATION; EXCISION-REPAIR; PURINE LESIONS; HUMAN HOMOLOG; FREE-RADICALS; GLYCOSYLASE; CLONING AB Two genes of Saccharomyces cerevisiae, NTG1 and NTG2, encode proteins with a significant sequence homology to the endonuclease III of Escherichia coli. The Ntg1 and Ntg2 proteins were overexpressed in E. coli and purified to apparent homogeneity, The substrate specificity of Ntg1. and Ntg2 proteins for modified bases in oxidatively damaged DNA was investigated using gas chromatography/isotope-dilution mass spectrometry. The substrate used was calf-thymus DNA exposed to gamma-radiation in N2O-saturated aqueous solution. The results reveal excision by Ntg1 and Ntg2 proteins of six pyrimidine-derived lesions, 5-hydroxy-6-hydrothymine, 5-hydroxy-6-hydrouracil, 5-hydroxy-5-methylhydantoin, 5-hydroxyuracil, 5-hydroxycytosine and thymine glycol, and two purine-derived lesions, 2,6-diamino-4-hydroxy-5-formamidopyrimidine and 4,6-diamino-5-formamidopyrimidine from gamma-irradiated DNA. In contrast, Ntg1 and Ntg2 proteins do not release 8-hydroxyguanine or 8-hydroxyadenine from gamma-irradiated DNA. The Ntg1 and Ntg2 proteins also release 2,6-diamino-4-hydroxy-5-N-methylformamido-pyrimidine from dam aged poly(dG-dC).poly(dG-dC). Excision was measured as a function of enzyme concentration and time. Furthermore, kinetic parameters were determined for each lesion. The results show that kinetic constants varied among the different lesions for the same enzyme. We also investigated the capacity of the Ntg1 and Ntg2 proteins to cleave 34mer DNA duplexes containing a single 8-OH-Gua residue mispaired with each of the four DNA bases. The results show that the Ntg1 protein preferentially cleaves a DNA duplex containing 8-OH-Gua mispaired with a guanine. Moreover, the Ntg1 protein releases free 8-OH-Gua from 8-OH-Gua/Gua duplex but not from duplexes containing 8-OH-Gua mispaired with adenine, thymine or cytosine. in contrast, the Ntg2 protein does not incise duplexes containing 8-OH-Gua mispaired with any of the four DNA bases. These results demonstrate that substrate specificities of the Ntg1 and Ntg2 proteins are similar but not identical and clearly different from that of the endonuclease III of E. coli and its homologues in Schizosaccharomyces pombe or human cells. C1 CEA, CNRS, DSV, Dept Radiobiol & Radiopathol,UMR217, F-92265 Fontenay Aux Roses, France. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Emory Univ, Sch Med, Dept Biochem, Atlanta, GA 30322 USA. Emory Univ, Sch Med, Dept Radiat Oncol, Atlanta, GA 30322 USA. RP Boiteux, S (reprint author), CEA, CNRS, DSV, Dept Radiobiol & Radiopathol,UMR217, F-92265 Fontenay Aux Roses, France. FU NCI NIH HHS [CA 73041] NR 45 TC 86 Z9 89 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD DEC 1 PY 1998 VL 26 IS 23 BP 5270 EP 5276 DI 10.1093/nar/26.23.5270 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 147WE UT WOS:000077487400006 PM 9826748 ER PT J AU Kim, S Hobbie, EK Yu, JW Han, CC AF Kim, S Hobbie, EK Yu, JW Han, CC TI Pattern formation and scaling in critical polymer mixtures under simple shear flow SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS LA English DT Article; Proceedings Paper CT International Conference on the Morphology and Kinetics of Phase Separating Complex Fluids CY JUN 24-28, 1997 CL MESSINA, ITALY ID ANGLE NEUTRON-SCATTERING; PHASE-SEPARATING FLUIDS; LIGHT-SCATTERING; CRITICAL-DYNAMICS; CRITICAL FLUCTUATIONS; CRITICAL-BEHAVIOR; BLEND; CROSSOVER; DEFORMATION; DROPS AB Polymer blends under flow are of profound technological importance. In situ microscopy and small-angle scattering permit detailed studies of such systems under simple shear: For phase-separated blends near a critical point of unmixing, homogenization occurs via repeated domain fragmentation, which gives way to distinct patterns in the strong-shear limit. Data for a variety; of systems collapse onto universal scaling curves that are in good agreement with modern theor ies of nonequilibrium critical phenomena. For strongly incompatible mixtures, however, the shear response appears to saturate in a manner that may have deep implications for the flow-induced blending of macromolecules. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 47 TC 0 Z9 0 U1 0 U2 0 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0392-6737 J9 NUOVO CIMENTO D JI Nuovo Cimento Soc. Ital. Fis. D-Condens. Matter At. Mol. Chem. Phys. Fluids Plasmas Biophys. PD DEC PY 1998 VL 20 IS 12BIS BP 2303 EP 2314 PG 12 WC Physics, Multidisciplinary SC Physics GA 214WU UT WOS:000081351200033 ER PT J AU Lykke, KR AF Lykke, KR TI Internally-coupled build-up cavity for frequency doubling of cw lasers SO OPTICS COMMUNICATIONS LA English DT Article DE build-up cavity; input coupling; cw lasers ID ENHANCEMENT; GENERATION; RESONATOR AB Replacing the input coupler in a ring build-up cavity with a broadband beamsplitter optimizes frequency doubling of cw laser radiation by allowing for careful control of input coupling by varying the input angle. We describe this simple and novel modification and discuss several other applications. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Lykke, KR (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 11 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD DEC 1 PY 1998 VL 157 IS 1-6 BP 88 EP 92 DI 10.1016/S0030-4018(98)00545-8 PG 5 WC Optics SC Optics GA 148PU UT WOS:000077541700017 ER PT J AU McLaughlin, SM Faisal, M AF McLaughlin, SM Faisal, M TI In vitro propagation of two Perkinsus species from the softshell clam Mya arenaria SO PARASITE-JOURNAL DE LA SOCIETE FRANCAISE DE PARASITOLOGIE LA English DT Article DE Perkinsus spp.; softshell clam (Mya arenaria); in vitro; zoosporulation ID MARINUS EXTRACELLULAR PRODUCTS; N-SP APICOMPLEXA; IN-VITRO; CRASSOSTREA-VIRGINICA; PATHOGEN; OYSTER; PROTEASES; INFECTION AB Two continuous, axenic cultures of Perkinsus spp. (H49 and G117)were obtained from the softshell clam Mya arenaria collected from Swan Point in the Chester River, Chesapeake Bay (Maryland). Isolate H49 was obtained from the hemolymph of a heavily infected clam. Except for their larger size, H49 trophozoites and schizonts exhibited the characteristic morphology of Perkinsus marinus and divided by schizogony. Isolate G117 was obtained from a combined gill/palp sample of a moderately infected clam. Unlike H49, vegetative forms (trophozoites and schizonts) of G117 were present along with prezoosporulation stages in the same culture. In culture, G117 cells multiplied by both schizogony and successive bi-partition. Both H49 and G117 cells reacted positively with anti-Perkinsus marinus polyclonal serum and formed hypnospores upon incubation in Ray's fluid thioglycolate medium that stained black with Lugol's iodine. This is the first isolation of Perkinsus species from the softshell clam. Studies to determine the infectivity, pathogenicity, enzyme activities, and genotyping of both softshell clam Perkinsus spp. are ongoing. C1 Natl Marine Fisheries Serv, Cooperat Oxford Lab, Oxford, MD 21654 USA. Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP McLaughlin, SM (reprint author), Natl Marine Fisheries Serv, Cooperat Oxford Lab, 904 S Morris St, Oxford, MD 21654 USA. NR 20 TC 18 Z9 18 U1 1 U2 1 PU PRINCEPS EDITIONS PI ISSY MOULINEAUX PA 64 AVENUE CHARLES DE GAULLE, 92130 ISSY MOULINEAUX, FRANCE SN 1252-607X J9 PARASITE JI Parasite-J. Soc. Fr. Parasitol. PD DEC PY 1998 VL 5 IS 4 BP 341 EP 348 PG 8 WC Parasitology SC Parasitology GA 151MN UT WOS:000077724200006 ER PT J AU Bendersky, LA Vanderah, TA Roth, RS AF Bendersky, LA Vanderah, TA Roth, RS TI Structural study of a group of magnetic multilayered oxides in the BaO-TiO2-Fe2O3 system I. High-resolution electron microscopy SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article AB In recent work on phase equilibria relations in the BaO-Fe2O3-TiO2 system, numerous ternary compounds were found. Most of the new compounds are complex and exhibit new structural types. The structures of six of these compounds, the so-called E, M, K, N, L and J phases, were characterized by high-resolution electron microscopy. All compounds were shown to belong to a class of ordered intergrowth structures built from two types of alternating slabs related to the structures of hexagonal BaTiO3 (h-BaTiO3) and Ba12Fe28Ti15O84 ('12 t 14 t 15'), which are in thermodynamic equilibrium with most of the studied phases. All the phases exhibit close-packed structures built from [O, (Ba/O)] layers in different stacking sequences. The so-called P slab has a structure related to h-BaTiO3, in which Ti occupies the octahedral cation sites. The second type of slab, denoted H, exhibits related but somewhat different structures in the E and M phases (H'), and four other phases (H "). The structure of the H' slab is probably related to the spinel block portion of the 12 t 14 t 15 compound, whereas the H " slab is related to the entire 12 t 14 t 15 structure. Structural modelling on this basis resulted in a good fit with experimental compositions. One-dimensional structural disorder was observed for all the phases studied (with the exception of E). The disorder was shown to be related to the lower symmetry of the II-type slabs and reflects the poor spatial correlation between them. The structural analysis indicates that the II-type slabs are preferentially occupied by Fe, which is accommodated in both octahedral and tetrahedral sites, and dilute in Ba. The strongly heterogeneous distribution of Fe suggests that all six phases can be considered as self assembled magnetic multilayer structures, with potentially intriguing physical properties. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Bendersky, LA (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 15 TC 10 Z9 10 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD DEC PY 1998 VL 78 IS 6 BP 1299 EP 1328 PG 30 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 146KH UT WOS:000077427500006 ER PT J AU Poole, PH Donati, C Glotzer, SC AF Poole, PH Donati, C Glotzer, SC TI Spatial correlations of particle displacements in a glass-forming liquid SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL ID STRUCTURAL RELAXATION; SUPERCOOLED LIQUIDS; MOLECULAR-DYNAMICS; BETA-RELAXATION; TRANSITION; TERPHENYL; LENGTH AB We define a generic correlation function that quantifies the spatial correlation of single-particle displacements in liquids and amorphous systems. We evaluate this function using computer simulations of an equilibrium glass-forming liquid, and show that the displacements of particles are spatially correlated over a range that grows with decreasing temperature as the glass transition is approached. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Western Ontario, Dept Appl Math, London, ON N6A 5B7, Canada. NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RP Poole, PH (reprint author), Univ Western Ontario, Dept Appl Math, London, ON N6A 5B7, Canada. RI Poole, Peter/C-7943-2009; Donati, Claudio/J-5180-2012; OI Poole, Peter/0000-0001-5985-0585; Donati, Claudio/0000-0001-8688-1651 NR 47 TC 32 Z9 32 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 51 EP 59 DI 10.1016/S0378-4371(98)00376-8 PG 9 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000006 ER PT J AU Warren, JA Carter, WC Kobayashi, R AF Warren, JA Carter, WC Kobayashi, R TI A phase field model of the impingement of solidifying particles SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL ID KINETICS; GROWTH; TRANSITIONS AB We propose a model of the impingement of solidifying crystalline particles, the ensuing grain boundary formation, and grain coarsening. This model improves upon previous theoretical descriptions of this phenomenon, in that it has the proper behavior under rotations and is easy to implement numerically. Also, insight into the model is straightforward since the parameters are physically motivated, and anisotropy in both the liquid-solid and grain boundary energies can be introduced in a natural manner. A one dimensional analytic solution is presented. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Met, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. Hokkaido Univ, Res Inst Elect Sci, Sapporo, Hokkaido 060, Japan. RP Warren, JA (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. NR 14 TC 23 Z9 23 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 159 EP 166 DI 10.1016/S0378-4371(98)00381-1 PG 8 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000015 ER PT J AU Roosen, AR Carter, WC AF Roosen, AR Carter, WC TI Simulations of microstructural evolution: anisotropic growth and coarsening SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL DE silicon nitride; anisotropic coarsening; ostwald ripening ID BETA-SILICON NITRIDE; FRACTURE-TOUGHNESS; MECHANICAL-PROPERTIES; CRYSTAL-GROWTH; ALPHA-ALUMINA; GRAIN-GROWTH AB Two-dimensional calculations of anisotropic growth and coarsening are illustrated. This model is intended to simulate the development of microstructure in materials like silicon nitride. The model is comprised of an ensemble of polygonal particles with anisotropic surface energies and growth mobilities. Particle growth is modeled by linear kinetics with a driving force proportional to a difference between local supersaturation and an equilibrium chemical potential which depends on particle geometry and surface tension. The competition for solute for particle growth is calculated via the diffusion equation, and conservation laws determine the strength of sources (or sinks) in the diffusion equation. Statistics of particles size distributions are obtained and regimes of kinetic behavior are related to transitions from non-equilibrium to near-equilibrium kinetics. Computed microstructures are qualitatively comparable to those observed experimentally. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. RP Roosen, AR (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. EM roosen@lurch.nist.gov NR 16 TC 182 Z9 186 U1 5 U2 35 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 232 EP 247 DI 10.1016/S0378-4371(98)00377-X PG 16 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000021 ER PT J AU Woitke, O Djuric, N Dunn, GH Bannister, ME Smith, ACH Wallbank, B Badnell, NR Pindzola, MS AF Woitke, O Djuric, N Dunn, GH Bannister, ME Smith, ACH Wallbank, B Badnell, NR Pindzola, MS TI Absolute cross sections for excitation of the 2s S-2 -> 2p P-2 transition in B2+ and for electron-impact single ionization of B2+ SO PHYSICAL REVIEW A LA English DT Article ID LI-LIKE IONS; R-MATRIX; COUPLING METHOD; HYDROGEN; SCATTERING; CONTINUUM; ENERGY; BEAMS AB Absolute cross sections for electron-impact excitation of the 2s S-2-->2p P-2 transition of B2+ measured between 5.4 and 7.0 eV are presented. The results are in good agreement with the R-matrix-with-pseudostates (RMPS) calculation of Marchalant et al. [J. Phys. B 30, L435 (1997)]. Also presented are cross sections for electron-impact single ionization of B2+, including measurements between 25 and 200 eV and calculations using the RMPS and time-dependent close-coupling methods. The measured ionization cross sections are about 14% higher near the peak than previous measurements by Crandall er nl. [Phys. Rev. A 34, 1757 (1986)], but agree well with experimental data of Hofmann et al. [Z. Phys. D 16, 113 (1990)] and with the present and other theoretical predictions. [S1050-2947(98)01212-8]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. St Francis Xavier Univ, Dept Phys, Antigonish, NS B2G 2W5, Canada. Univ Strathclyde, Dept Phys & Appl Phys, Glasgow G4 0NG, Lanark, Scotland. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. RP Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 29 TC 26 Z9 26 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1998 VL 58 IS 6 BP 4512 EP 4517 DI 10.1103/PhysRevA.58.4512 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700036 ER PT J AU DeMarco, B Jin, DS AF DeMarco, B Jin, DS TI Exploring a quantum degenerate gas of fermionic atoms SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; TEMPERATURE; SCATTERING AB We predict phenomena in the behavior of an ultracold, trapped gas of fermionic atoms. We find that quantum statistics radically changes the collisional properties, spatial profile, and off-resonant light-scattering properties of the atomic fermion system, and we suggest how these effects can be observed. [S1050-2947(98)50112-6]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP DeMarco, B (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 25 TC 36 Z9 36 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1998 VL 58 IS 6 BP R4267 EP R4270 DI 10.1103/PhysRevA.58.R4267 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700003 ER PT J AU Yokoo, T Raymond, S Zheludev, A Maslov, S Ressouche, E Zaliznyak, I Erwin, R Nakamura, M Akimitsu, J AF Yokoo, T Raymond, S Zheludev, A Maslov, S Ressouche, E Zaliznyak, I Erwin, R Nakamura, M Akimitsu, J TI Magnetic ordering, spin waves, and Haldane-gap excitations in (NdxY1-x)(2)BaNiO5 linear-chain mixed-spin antiferromagnets SO PHYSICAL REVIEW B LA English DT Article ID ONE-DIMENSIONAL ANTIFERROMAGNETS; SOFT-MODE TRANSITION; NEUTRON-SCATTERING; MONTE-CARLO; FIELD; ND2BANIO5; Y2BANIO5; NENP; DIFFRACTION; PR2BANIO5 AB Linear-chain nickelates with the composition (NdxY1-x)(2)BaNiO5 (x = 1, x = 0.75, x = 0.5, and x = 0.25) are studied in a series of neutron-scattering experiments. Powder diffraction is used to determine the temperature dependence of the magnetic structure in all four systems. Single-crystal inelastic neutron scattering is employed to investigate the temperature dependence of the Haldane-gap excitations and low-energy spin waves in the x= 1 compound Nd2BaNiO5. The results of these experiments are discussed in the context of the "Haldane chain in a staggered field" model for R2BaNiO5 systems, and quantitative agreement with theory is obtained. [SO163-1829(98)07945-4]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. CEN, MDN, SPSMS, DRFMC, F-38054 Grenoble, France. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 157, Japan. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. PL Kapitza Phys Problems Inst, Moscow, Russia. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Zaliznyak, Igor/E-8532-2014; Maslov, Sergei/C-2397-2009 OI Zaliznyak, Igor/0000-0002-9886-3255; Maslov, Sergei/0000-0002-3701-492X NR 47 TC 41 Z9 41 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14424 EP 14435 DI 10.1103/PhysRevB.58.14424 PG 12 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000059 ER PT J AU Romero, DB Podobedov, VB Weber, A Rice, JP Mitchell, JF Sharma, RP Drew, HD AF Romero, DB Podobedov, VB Weber, A Rice, JP Mitchell, JF Sharma, RP Drew, HD TI Polarons in the layered perovskite manganite La1.2Sr1.8Mn2O7 SO PHYSICAL REVIEW B LA English DT Article ID COLOSSAL-MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; OXIDES; SUPERCONDUCTIVITY; PHONON; ORDER AB The temperature (6-350 K) and magnetic-field dependence (0-7.5 T) of the phononic Raman spectra in the layered manganites, R1.2Sr1.8Mn2O7 (R = La,Nd), reveal anomalous behaviors of the Mn and equatorial O-xy(Big) modes arising from local octahedral distortions and coupling to the Mn3+ e(g) electrons. These results provide the evidence for polaron formation and its interplay with electrical transport and magnetism in the layered manganites. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Russian Acad Sci, Inst Spect, Troitsk 142092, Moscow Region, Russia. RP Podobedov, VB (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 21 TC 27 Z9 27 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 1998 VL 58 IS 22 BP 14737 EP 14740 PG 4 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000020 ER PT J AU Balbach, JJ Conradi, MS Hoffmann, MM Udovic, TJ Adolphi, NL AF Balbach, JJ Conradi, MS Hoffmann, MM Udovic, TJ Adolphi, NL TI Nuclear magnetic resonance evidence of disorder and motion in yttrium trideuteride SO PHYSICAL REVIEW B LA English DT Article ID SWITCHABLE OPTICAL-PROPERTIES; LANTHANUM HYDRIDE FILMS; THEORETICAL PREDICTION; ELECTRONIC-STRUCTURE; HYDROGEN DIFFUSION; INSULATING YH3; METAL-HYDRIDES; NMR; DYNAMICS; SITE AB Three samples of YDx, with x ranging from 2.9 to nearly 3.0, were studied with deuterium nuclear magnetic resonance to gain insight into the locations of the D atoms in the lattice and their motions. Line shapes at low temperatures (200-330 K) show substantial disorder at some of the deuterium sites. Near 355 K, the spectrum sharpens to yield three uniaxial Fake patterns, reflecting a motional averaging process. However, the three measured intensities do not match the ratios expected from the neutron-determined, HoD3-like structure. This is strong evidence that the structure and space group of YD3 are different than reported, or that the current model needs adjustment. At still higher temperatures near 400 K, the Fake doublet features broaden, and a single sharp resonance develops, signalling a diffusive motion that carries all D atoms over all sites. The temperature at which line shape changes occur depends on the number of deuterium vacancies, 3-x. The changes occur at lower temperatures in the most defective sample, indicating the role of D-atom vacancies in the motional processes. The longitudinal relaxation rate T-1(-1) displays two regimes, being nearly temperature independent below 300 K and strongly thermally activated above. The relaxation rate depends on the number of deuterium vacancies, 3-x, varying an order of magnitude over the range of stoichiometries studied and suggesting that D-atom diffusion is involved. Also, the activation energy describing T-1(-1) (similar or equal to k(B)x 5500 K) approximately matches that for diffusion. An unusual omega(0)(-0.7) frequency dependence of T-1(-1) is observed. A relaxation mechanism is proposed in which diffusion is the Pate-determining step and in which frequency dependence arises from a field-dependent radius of the relaxation zones. [S0163-1829(98)07845-X]. C1 NIDDKD, NIH, Bethesda, MD 20892 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Knox Coll, Dept Phys, Galesburg, IL 61401 USA. RP Balbach, JJ (reprint author), NIDDKD, NIH, Bethesda, MD 20892 USA. NR 31 TC 20 Z9 20 U1 0 U2 1 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 1998 VL 58 IS 22 BP 14823 EP 14832 DI 10.1103/PhysRevB.58.14823 PG 10 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000036 ER PT J AU Vasiliu-Doloc, L Lynn, JW Moudden, AH de Leon-Guevara, AM Revcolevschi, A AF Vasiliu-Doloc, L Lynn, JW Moudden, AH de Leon-Guevara, AM Revcolevschi, A TI Structure and spin dynamics of La0.85Sr0.15MnO3 SO PHYSICAL REVIEW B LA English DT Article ID LIGHTLY DOPED LA1-XSRXMNO3; DOUBLE-EXCHANGE; TRANSITION; X-LESS-THAN-OR-EQUAL-TO-0.17; RESISTIVITY; FERROMAGNET; WAVES AB Neutron scattering has been used to study the structure and spin dynamics of La0.85Sr0.15MnO3. The magnetic structure of this system is ferromagnetic below T(C)similar or equal to 235 K. We see anomalies in the Bragg peak intensities and new superlattice peaks consistent with the onset of a spin-canted phase below T(CA)similar to 205 K, which appears to be associated with a small gap at q=(0,0,0.5) in the spin-wave spectrum. Anomalies in the lattice parameters indicate a concomitant lattice distortion. The long-wavelength magnetic excitations are found to be conventional spin waves, with a gapless (< 0.02 meV) isotropic dispersion relation E = Dq(2). The spin stiffness constant D has a T-5/2 dependence at low T, and the damping at small q follows q(4)T(2). An anomalously strong quasielastic component, however, develops at small wave vector above similar to 200 K and dominates the fluctuation spectrum as Ti Tc. At larger q, on the other hand, the magnetic excitations become heavily damped at low temperatures, indicating that spin waves in this regime are not eigenstates of the system, while raising the temperature dramatically increases the damping. The strength of the spin-wave damping also depends strongly on the symmetry direction in the crystal. These anomalous damping effects are likely due to the itinerant character of the e(g) electrons. [S0163-1829(98)02945-2]. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Supercond Res, College Pk, MD 20742 USA. CENS, CEA, CNRS, Leon Brillouin Lab, F-91191 Gif Sur Yvette, France. Univ Paris Sud, Chim Solide Lab, F-91405 Orsay, France. RP Vasiliu-Doloc, L (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 35 TC 61 Z9 61 U1 3 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 DEC 1 PY 1998 VL 58 IS 22 BP 14913 EP 14921 DI 10.1103/PhysRevB.58.14913 PG 9 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000049 ER PT J AU Wong-Ng, W Kaduk, JA Greenwood, W AF Wong-Ng, W Kaduk, JA Greenwood, W TI Crystal structures and reference x-ray powder diffraction patterns of Sr4-xCaxPb2O8 (x=1,2,3) SO POWDER DIFFRACTION LA English DT Article ID BOND-VALENCE PARAMETERS; TEXTURED BUFFER LAYERS; COMPOSITE CONDUCTORS; THICK-FILMS; PHASE; TAPES; AG; STABILITY; SILVER; LEAD AB The crystal structure of the solid solution alkaline earth plumbate phase Sr4-xCaxPb2O8 was investigated using the X-ray Rietveld technique for x = 1, 2, and 3. The lattice parameters a, b, c, and V were found to decrease linearly as the Sr at site 4h was replaced by Ca. The structure features chains of edge-sharing PbO6 octahedra, linked by seven-coordinated (Ca/Sr)-O monocapped trigonal prisms. The structure is similar to that of Pb3O4, which can be reformulated as (Pb2PbO4)-Pb-II-O-IV. X-ray diffraction patterns for the solid solution members SrCa3Pb2O8, Sr2Ca2Pb2O8, and Sr3CaPb2O8 were prepared for inclusion in the Powder Diffraction File. (C) 1998 International Centre for Diffraction Data. [S0885-7156(98)00402-3]. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. Amoco Corp, Naperville, IL 60566 USA. Univ Maryland, Dept Geol, College Pk, MD 20742 USA. RP Wong-Ng, W (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 42 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD DEC PY 1998 VL 13 IS 4 BP 232 EP 240 PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA 149QD UT WOS:000077615900008 ER PT J AU Cole, J McGlade, J AF Cole, J McGlade, J TI Clupeoid population variability, the environment and satellite imagery in coastal upwelling systems SO REVIEWS IN FISH BIOLOGY AND FISHERIES LA English DT Review DE clupeoids; coastal upwelling; population dynamics; recruitment; satellite imagery ID SURFACE TEMPERATURE VARIABILITY; SOUTH-AFRICAN ANCHOVY; PELAGIC FISH; RECRUITMENT SUCCESS; BENGUELA ECOSYSTEM; TIME-SERIES; FLUCTUATIONS; MANAGEMENT; RESOURCES; OCEANOGRAPHY AB Sardine, pilchard and anchovy stocks form the basis of commercially important purse seine fisheries in eastern boundary upwelling regions. High levels of environmentally driven recruitment variability have, however, made them especially difficult to manage. Reliable forecasts of recruitment success would greatly help with the setting of catch quotas prior to each fishing season. Theories of how environmental conditions influence recruitment success, according to survival/mortality of the early life-history stages, can be divided into mechanistic and sythesis theories. Mechanistic theories are concerned with specific physical processes, whereas synthesis theories attempt to unite the various mechanistic processes within a single conceptual framework. Despite the successful testing of some theories, there has been little success in reliably predicting recruitment success from a knowledge of environmental conditions. Possible reasons include the following: non-linearity in the relationship between environmental parameters and recruitment: the poor spatial and temporal resolution of much oceanographic data; the wide range of different factors involved in determining recruitment success; and the choice of environmental index. The recent compilation of time series of satellite images for these regions offers a solution to some of these problems, and in doing so reopens the possibility of finding sufficiently good relationships between environmental conditions and recruitment success for management purposes. In particular, the high resolution of these time series allows for the construction of environmental indices across many different spatial and temporal scales. These time series also open up the possibility of quantifying the behaviour of upwelling systems according to the evolution of their spatial structure through time, using pattern analysis techniques. C1 NOAA, Pacific Fisheries Environm Lab, NMFS, Pacific Grove, CA 93950 USA. Plymouth Marine Lab, NERC, Ctr Coastal & Marine Sci, Plymouth PL1 3DH, Devon, England. RP Cole, J (reprint author), NOAA, Pacific Fisheries Environm Lab, NMFS, 1352 Lighthouse Ave, Pacific Grove, CA 93950 USA. NR 102 TC 67 Z9 72 U1 3 U2 13 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0960-3166 J9 REV FISH BIOL FISHER JI Rev. Fish. Biol. Fish. PD DEC PY 1998 VL 8 IS 4 BP 445 EP 471 DI 10.1023/A:1008861224731 PG 27 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 162LP UT WOS:000078348100004 ER PT J AU Wang, ZY Jiang, Q White, GS Richardson, AK AF Wang, ZY Jiang, Q White, GS Richardson, AK TI Processing flaws in PZT transducer rings SO SMART MATERIALS & STRUCTURES LA English DT Article ID ZIRCONATE-TITANATE CERAMICS; FERROELECTRIC CERAMICS; PIEZOELECTRIC CERAMICS; ELECTRIC FATIGUE; FRACTURE-MECHANICS; DAMAGE; PBO AB In industrial fabrication, many PZT transducer rings fail to meet the specifications of physical properties, and some of them even fracture during poling, the final stage of fabrication. The microscopic examination of fractured surfaces, using SEM, shows the presence of pores and microcracks that intersect with pores of size significantly larger than the average grain size. Evaluation of the semi-finished products at various stages of fabrication indicates that the pores formed during pressing and the microcracks were initiated during poling. The strong correlation of microcracks with sharp wedges, each formed by two adjacent grains at the edge of a pore, suggests that these microcracks originated from the sharp wedges where severe stress concentrations usually occur. Significant inhomogeneities in composition of the as-sintered samples were dectected using EDS, and these inhomogeneities are attributed to the inhomogeneous evaporation of Pb and the presence of a liquid phase during sintering. The x-ray diffraction patterns indicate a reduction of the Ti/Zr molar ratio during sintering that, together with observation of second-phase particles at some triple grain junctions, suggests the presence of a liquid phase during sintering. C1 Univ Nebraska, Dept Engn Mech, Lincoln, NE 68588 USA. Univ Calif Riverside, Coll Engn, Riverside, CA 92521 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. EDO Corp, Div Ceram, Salt Lake City, UT 84115 USA. NR 30 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1998 VL 7 IS 6 BP 867 EP 873 DI 10.1088/0964-1726/7/6/014 PG 7 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 158FQ UT WOS:000078105700014 ER PT J AU Neupert, WM Newmark, J Delaboudiniere, JP Thompson, BJ Catura, RC Moses, JD Gurman, JB Portier-Fozzani, F Gabriel, AH Artzner, G Clette, F Cugnon, P Maucherat, AJ Defise, JM Jamar, C Rochus, P Dere, KP Howard, RA Michels, DJ Freeland, S Lemen, JR Stern, RA AF Neupert, WM Newmark, J Delaboudiniere, JP Thompson, BJ Catura, RC Moses, JD Gurman, JB Portier-Fozzani, F Gabriel, AH Artzner, G Clette, F Cugnon, P Maucherat, AJ Defise, JM Jamar, C Rochus, P Dere, KP Howard, RA Michels, DJ Freeland, S Lemen, JR Stern, RA TI Observations of coronal structures above an active region by EIT and implications for coronal energy deposition SO SOLAR PHYSICS LA English DT Article ID TEMPERATURE STRUCTURE; SOLAR CORONA; LOOPS; YOHKOH; TELESCOPE; EMISSION; DYNAMICS; WIND; MASS; FLOW AB Solar EUV images recorded by the EW Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the temperature range of 1.0-2.0 MK. Such observations permit estimates of longitudinal temperature gradients (Lf present) in the corona and, consequently, estimates of thermal conduction and radiative losses as a function of position in the features. We examine two relatively cool features as recorded in EIT's Fe IX/X (171 Angstrom) and Fe XII (195 Angstrom) bands in a decaying active region. The first is a long-lived loop-like feature with one leg, ending in the active region, much more prominent than one or more distant footpoints assumed to be rooted in regions of weakly enhanced field. The other is a near-radial feature, observed at the West limb, which may be either the base of a very high loop or the base of a helmet streamer We evaluate energy requirements to support a steady-state energy balance in these features and find in both instances that downward thermal conductive losses (at heights above the transition region) are inadequate to support local radiative losses, which are the predominant loss mechanism. The requirement that a coronal energy deposition rate proportional to the square of the ambient electron density (or pressure) is present in these cool coronal features provides an additional constraint on coronal heating mechanisms. C1 NOAA, SEC, Code RESE, Boulder, CO 80303 USA. RP NOAA, SEC, Code RESE, 325 Broadway, Boulder, CO 80303 USA. RI Thompson, Barbara/C-9429-2012 NR 33 TC 43 Z9 44 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD DEC PY 1998 VL 183 IS 2 BP 305 EP 321 DI 10.1023/A:1005045512509 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 161GU UT WOS:000078281500008 ER PT J AU Charba, JP AF Charba, JP TI The LAMP QPF products. Part I: Model development SO WEATHER AND FORECASTING LA English DT Article ID NATIONAL-WEATHER-SERVICE; FLOOD PROGRAM; RIVER; MODERNIZATION; FORECASTS AB The Local AWIPS (Advanced Weather Interactive Processing System) MOS (model output statistics) Program (LAMP) quantitative precipitation forecast (QPF) system produces 1-22-h forecasts of precipitation over the conterminous United States. The forecasts are generated for points on a rectangular grid with a 20-km mesh and are in the form of probabilities for greater than or equal to 0.10 (2.5), greater than or equal to 0.25 (6.4), greater than or equal to 0.50 (12.7), greater than or equal to 1.00 (25.4), and greater than or equal to 2.00 (50.8) in. (mm). The forecasts are also available in the form of the best category and expected precipitation, both of which are derived from the probabilities. The forecasts are valid for four l-h periods in the 1-5-h range, two 3-h periods in the 4-10-h range, and two 6-h periods in the 7-22-h range. Upon implementation on the AWIPS system, the model could produce the forecasts as often as hourly. The LAMP QPFs are based on multiple regression equations, which are derived for 32 geographical regions, two seasons (warm and cool), and eight cycle times per day. The predictand is defined from 2500 to 3000 stations that compose the U.S. Climatic Hourly Precipitation Network. Predictors in the equations are derived from multiple data inputs, which include 1) centralized MOS QPF probability forecasts, 2) numerical model forecasts of 850-mb wind, 3) objectively analyzed and advected fields of variables based primarily on conventional hourly surface observations, 4) objectively analyzed and advected fields of 1- and 3-h antecedent precipitation, and 5) high-resolution topography and climatic monthly mean relative Frequencies of precipitation categories. An innovative feature of the model is application of predictors that describe the interaction between finescale geoclimatic parameters and ambient low-level wind, moisture, and MOS QPF variables relative to precipitation occurrence. Predictors included in the QPF regression equations vary significantly as a function of forecast projection and geographical area. For the four l-h valid periods that extend to 5 h, predictors are based largely on the observational data inputs. For the two 6-h periods that extend to 22 h, MOS QPFs are the dominant predictor input. The intervening 3-h valid periods exhibit a more uniform blend of the various predictor inputs. Geographically, the MOS input has more influence in the eastern United States than elsewhere, whereas the topographical, climatological, and antecedent precipitation inputs exert a strong influence in the west. Distinctive properties of the LAMP probability and derived forecast products are illustrated for a heavy rain event. Predictors that underlie the properties are identified. C1 NOAA, Natl Weather Serv, Techniques Dev Lab, Off Syst Dev, Silver Spring, MD 20910 USA. RP Charba, JP (reprint author), NOAA, Natl Weather Serv, Techniques Dev Lab, Off Syst Dev, W-OSD24,1325 East West Hwy, Silver Spring, MD 20910 USA. NR 45 TC 15 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 1998 VL 13 IS 4 BP 934 EP 965 DI 10.1175/1520-0434(1998)013<0934:TLQPPI>2.0.CO;2 PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200003 ER PT J AU Pan, JF van den Dool, H AF Pan, JF van den Dool, H TI Extended-range probability forecasts based on dynamical model output SO WEATHER AND FORECASTING LA English DT Article ID NATIONAL METEOROLOGICAL CENTER; ENSEMBLE PREDICTION; NMC; PREDICTABILITY; PERTURBATIONS AB A probability forecast has advantages over a deterministic forecast as the former offers information about the probabilities of various possible future states of the atmosphere. As physics-based numerical models find their success in modern weather forecasting, an important task is to convert a model forecast, usually deterministic, into a probability forecast. This study explores methods to do such a conversion for NCEP's operational 500 mb-height forecast and the discussion is extended to ensemble forecasting. Compared with traditional model-based statistical forecast methods such as Model Output Statistics, in which a probability forecast is made from statistical relationships derived from single model-predicted fields and observations, probability forecasts discussed in this study are focused on probability information directly provided by multiple runs of a dynamical model-eleven 0000 UTC runs at T62 resolution. To convert a single model forecast into a strawman probability forecast (single forecast probability or SFP), a contingency table is derived from historical forecast-verification data. Given a forecast for one of three classes (below, normal, and above the climatological mean), the SFP probabilities are simply the conditional (or relative) frequencies at which each of three categories are observed over a period of time. These probabilities have good reliability (perfect for dependent data) as long as the model is not changed and maintains the same performance level as before. SFP, however, does not discriminate individual cases and cannot make use of information particular to individual cases. For ensemble forecasts, ensemble probabilities (EP) are calculated as the percentages of the number of members in each category based on the given ensemble samples. This probability specification method fully uses probability information provided by the ensemble. Because of the limited ensemble size, model deficiencies, and because the samples may be unrepresentative, EP probabilities are not reliable and appear to be too confident, particularly at forecast leads beyond day 6. The authors have attempted to combine EP with SFP to improve the EP probability (referred to as modified forecast probability). Results show that a simple combination (plain average) can considerably improve upon both the EP and SFP. C1 NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 USA. RP van den Dool, H (reprint author), NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 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. PD DEC PY 1998 VL 13 IS 4 BP 983 EP 996 DI 10.1175/1520-0434(1998)013<0983:ERPFBO>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200005 ER PT J AU Aberson, SD AF Aberson, SD TI Five-day tropical cyclone track forecasts in the North Atlantic basin SO WEATHER AND FORECASTING LA English DT Article ID HURRICANES; INTENSE AB Statistical analyses of the most recent 40 yr of hurricane track (1956-95) are presented, leading to a version of the North Atlantic climatology and persistence (CLIPER) model that exhibits much smaller forecast biases but similar forecast errors compared to the previously used version. Changes to the model involve the inclusion of more accurate historical tropical cyclone track data and a simpler derivation of the regression equations. Nonlinear systems analysis shows that the predictability timescale in which the average errors increase by a factor e is approximately 2.5 days in the Atlantic basin, which is larger than that found by similar methods near Australia. This suggests that 5-day tropical cyclone track forecasts may have some benefit, and therefore a version of CLIPER extended to 5 days to be used as a baseline to measure this skill is needed. C1 NOAA, Atlantic Oceanog & Meteorol Lab, ERL, Hurricane Res Div, Miami, FL 33149 USA. RP Aberson, SD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, ERL, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Aberson, Sim/C-4891-2013 OI Aberson, Sim/0000-0002-3670-0100 NR 11 TC 67 Z9 68 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 1998 VL 13 IS 4 BP 1005 EP 1015 DI 10.1175/1520-0434(1998)013<1005:FDTCTF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200007 ER PT J AU Lenning, E Fuelberg, HE Watson, WI AF Lenning, E Fuelberg, HE Watson, WI TI An evaluation of WSR-88D severe hail algorithms along the northeastern Gulf Coast SO WEATHER AND FORECASTING LA English DT Article AB Software build 9.0 for the Weather Surveillance Radar-1988 Doppler (WSR-88D) contains several new or improved algorithms for detecting severe thunderstorms. The WSR-88D Operational Support Facility supports testing and optimization of these algorithms by local National Weather Service offices. This paper presents a new methodology for using Storm Data in these local evaluations. The methodology defines specific conditions a storm cell must meet to be included in the evaluation. These conditions include cell intensity and duration, population density along the cell track, and any previous severe reports in the county where the storm is located. These requirements avoid including storm cells that may have produced severe weather where reports would be very unlikely. The technique provides a more accurate picture of algorithm performance than if Storm Data is used with no special considerations. This study utilizes the new methodology with data currently available for the Tallahassee, Florida, county warning area (TLH CWA). It describes the performance of two algorithms used for detecting severe hail. The first is the Probability of Severe Hail (POSH), a component of the build 9.0 Hail Detection Algorithm. The second is the algorithm that calculates vertically integrated liquid (VIL). Early results show that the recommended POSH threshold of 50% appears appropriate for the TLH CWA. This suggests that the height of the freezing level provides a reasonably good estimate of the best severe hail index (SHI). However, early results also indicate that the average wet-bulb temperature from 1000 to 700 mb (low-level wet-bulb temperature) might produce an even better indication of the SHI threshold. Similarly, the threshold for VIL is highly correlated to the low-level wet-bulb temperature. Finally, the VIL algorithm is found to perform as well as the POSH parameter if the best VIL threshold can be determined in advance. Since the database used in these evaluations was relatively small, these Endings should be considered tentative. C1 Florida State Univ, Tallahassee, FL 32306 USA. NOAA, Natl Weather Serv, Tallahassee, FL USA. RP Lenning, E (reprint author), 2W1,1500 PRC Dr, Mclean, VA 22102 USA. NR 27 TC 11 Z9 12 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 1998 VL 13 IS 4 BP 1029 EP 1044 DI 10.1175/1520-0434(1998)013<1029:AEOWSH>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200009 ER PT J AU Miller, MA Verlinde, J Gilbert, CV Lehenbauer, GJ Tongue, JS Clothiaux, EE AF Miller, MA Verlinde, J Gilbert, CV Lehenbauer, GJ Tongue, JS Clothiaux, EE TI Detection of nonprecipitating clouds with the WSR-88D: A theoretical and experimental survey of capabilities and limitations SO WEATHER AND FORECASTING LA English DT Article ID DOPPLER RADAR AB Theoretical calculations and experiments verify that the National Weather Service WSR-88D radars have the sensitivity to detect nonprecipitating clouds, but shaw that significant obstacles impair the generality of this cloud sensing technique. Bragg scatter from refractive index inhomogeneities can be of the same magnitude as cloud echoes under many conditions, whereupon interpretation of WSR-88D echoes can be either complicated or impossible. Moreover, problems with echoes from ground clutter and from insects, birds, and other floating debris hinder WSR-88D cloud detection capabilities, particularly at low elevation angles. To illustrate these problems WSR-88D reflectivities collected using volume coverage pattern (VCP) 21 from the months of March and October 1996 were compared with collocated reflectivities obtained from a zenith-pointing 94-GHz cloud radar located in central Pennsylvania. Coincident echo detection occurred 82% and 39% of the time, while the WSR-88D had significant detections 7% and 44% more of the time, during the March and October periods, respectively. For the coincident detections, there were a number of discrepancies in the reflectivity values that were a function of season, height, and time of day. In a separate analysis the WSR-88D located in Upton, Long Island, New York, was used to validate the theoretical minimum detectable signal of the radar in VCP 31 and show that ground clutter contamination may remain despite the use of clutter suppression techniques. In summary, the results of this study suggest that WSR-88D reflectivity data may contain useful information about cloud structure when cloud droplets are the dominant scatterers. To determine if they are dominant requires information about the turbulent structure of the measurement volume and a method to discriminate undesirable targets such as ground clutter, insects, and birds. These requirements suggest that remotely sensing nonprecipitating and lightly precipitating clouds with the WSR-88D would be a difficult process to automate. Extrapolation of the results of this study imply that the best time to remotely sense low clouds with the WSR-88D may be winter nights and mornings when 1) clouds and wind prevent the development of a strong surface-based inversion that can produce beam ducting that enhances ground clutter, 2) insects and birds are not present, and 3) moisture gradients in the lower troposphere are relatively weak, which may reduce the likelihood that Bragg scatter from turbulent eddies would dominate Rayleigh scatter from cloud droplets. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Natl Weather Serv, Weather Forecast Off, Upton, NY USA. RP Miller, MA (reprint author), Brookhaven Natl Lab, Dept Appl Sci, POB 5000, Upton, NY 11973 USA. NR 18 TC 13 Z9 13 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 1998 VL 13 IS 4 BP 1046 EP 1062 DI 10.1175/1520-0434(1998)013<1046:DONCWT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200010 ER PT J AU Ziegler, CL Rasmussen, EN AF Ziegler, CL Rasmussen, EN TI The initiation of moist convection at the dryline: Forecasting issues from a case study perspective SO WEATHER AND FORECASTING LA English DT Article ID LAYER CONVERGENCE LINES; SEA-BREEZE FRONT; BOUNDARY-LAYER; THUNDERSTORM INITIATION; WEATHER; CAPE; CLIMATE; STORMS; EVOLUTION; SATELLITE AB The processes that force the initiation of deep convection along the dryline are inferred from special mesoscale observations obtained during the 1991 Central Oklahoma Profiler Studies project, the Verification of the Origins of Rotation in Tornadoes Experiment 1994 (VORTEX-94), and the VORTEX-95 held projects. Observations from aircraft, mobile CLASS soundings, and mobile mesonets define the fields of airflow, absolute humidity, and virtual temperature in the boundary layer across the dryline on the 15 May 1991, 7 June 1994, and 6 May 1995 case days. Film and video cloud images obtained by time-lapse cameras on the NOAA P-3 are used to reconstruct the mesoscale distribution of cumulus clouds by photogrammetric methods, permitting inferences concerning the environmental conditions accompanying cloud formation or suppression. The results of the present study confirm the classical notion that the dryline is a favored zone for cumulus cloud formation. The combined cloud distributions for the three cases are approximately Gaussian, suggesting a peak expected cloud frequency 15 km east of the dryline. Deep mesoscale moisture convergence is inferred in cloudy regions, with either subsidence or a lack of deep convergence in cloud-free regions. The results document the modulating effect of vertical wind shear and elevated dry layers in combination with the depth and strength of mesoscale updrafts on convective initiation, supporting the notion that moist boundary layer air parcels must be lifted to their lifted condensation level and level of free convection prior to leaving rile mesoscale updraft to form deep convection. By relaxing the overly restrictive assumptions of parcel theory, it is suggested that a modification of proximity soundings to account for mesoscale lift and westerly wind shear effects can improve the diagnosis of the mesoscale dryline environment and the prediction of convective initiation at the dryline. Conversely, proximity environmental soundings, taken by themselves with consideration of CAFE and convective inhibition values according to parcel theory but neglecting vertical boundary layer circulations, are found to have less prognostic value than is conventionally assumed. C1 NOAA, Natl Severe Storms Lab, Mesoscale Res & Applicat Div, Norman, OK 73069 USA. RP Ziegler, CL (reprint author), NOAA, Natl Severe Storms Lab, Mesoscale Res & Applicat Div, 1313 Halley Circle, Norman, OK 73069 USA. NR 60 TC 93 Z9 93 U1 2 U2 12 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 1998 VL 13 IS 4 BP 1106 EP 1131 DI 10.1175/1520-0434(1998)013<1106:TIOMCA>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200014 ER PT J AU Rasmussen, EN Blanchard, DO AF Rasmussen, EN Blanchard, DO TI A baseline climatology of sounding-derived supercell and tornado forecast parameters SO WEATHER AND FORECASTING LA English DT Article ID RESPONSE PERMUTATION PROCEDURES; SQUALL LINES; MESOSCALE LINES; ENVIRONMENTS; THUNDERSTORM; PRECIPITATION; SHEAR; MESOCYCLONES; OKLAHOMA; BUOYANCY AB Ail of the 0000 UTC soundings from the United States made during the year 1992 that have nonzero convective available potential energy (CAPE) are examined. Soundings are classified as being associated with nonsupercell thunderstorms, supercells without significant tornadoes, and supercells with significant tornadoes. This classification is made by attempting to pair, based on the low-level sounding winds, an upstream sounding with each occurrence of a significant tornado, large hail, and/or 10 or more cloud-to-ground lightning Bashes. Severe weather wind parameters (mean shear, 0-6-km shear, storm-relative helicity, and storm-relative anvil-level Bow) and CAFE parameters (total CARE and CAFE in the lowest 3000 m with buoyancy) are shown to discriminate weakly between the environments of the three classified types of storms. Combined parameters (energy-helicity index and vorticity generation parameter) discriminate strongly between the environments. The height of the lifting condensation level also appears to be generally lower for supercells with significant tornadoes than those without. The causes for the very large false alarm rates in the tornadic/nontornadic supercell forecast, even with the best discriminators, are discussed. C1 Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Boulder, CO 80301 USA. Univ Oklahoma, Norman, OK 73019 USA. RP Rasmussen, EN (reprint author), Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, 3450 Mitchell Lane,Bldg 3,Room 2034, Boulder, CO 80301 USA. EM rasmussen@nssl.noaa.gov NR 41 TC 292 Z9 304 U1 4 U2 19 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 1998 VL 13 IS 4 BP 1148 EP 1164 DI 10.1175/1520-0434(1998)013<1148:ABCOSD>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200016 ER PT J AU Hart, RE Forbes, GS Grumm, RH AF Hart, RE Forbes, GS Grumm, RH TI The use of hourly model-generated soundings to forecast mesoscale phenomena. Part I: Initial assessment in forecasting warm-season phenomena SO WEATHER AND FORECASTING LA English DT Article ID ETA AB Since late 1995, NCEP has made available to forecasters hourly model guidance at selected sites in the form of vertical profiles of various forecast fields. These profiles provide forecasters with increased temporal resolution and greater vertical resolution than had been previously available. The hourly forecast profiles are provided for all of NCEP's short-range models: the Nested Grid Model, Era Model, and Mesoscale Eta Model. The high-resolution forecasts aid in the timing of frontal passages, low-level jets, and convective initiation. In addition, through time-height cross sections of Richardson numbers, forecasters can alert pilots to the potential for clear air turbulence several hours to a day in advance. Further, the profiles are useful in prediction of cloudiness and the dissipation of low-level stratus and fog. Time-height cross sections of wind velocity have proven extraordinarily useful in visualizing and forecasting inversion heights, frontal passage timing, boundary layer depth, and available environmental and storm-relative helicity during convective events. The hourly model forecasts were found to be exceptionally helpful when combined with hourly surface observations to produce enhanced real-time analyses of convective parameters for use in very short term forecasting. High-resolution analyses of lifted index, CAFE, convective inhibition, moisture flux convergence, and 2-h changes in these fields aid the forecaster in anticipating convective trends. The introduction of model forecast error into these real-time analyses was minimized by using the latest available Era or Mesoscale Era Model runs. Therefore, the model data used to enhance the analyses are typically no more than 6-12 h old. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Natl Weather Serv, State Coll, PA USA. RP Hart, RE (reprint author), Penn State Univ, Dept Meteorol, 503 Walker Bldg, University Pk, PA 16802 USA. NR 12 TC 8 Z9 17 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 1998 VL 13 IS 4 BP 1165 EP 1185 DI 10.1175/1520-0434(1998)013<1165:FTTUOH>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200017 ER PT J AU Quayle, RG Steadman, RG AF Quayle, RG Steadman, RG TI The Steadman wind chill: An improvement over present scales SO WEATHER AND FORECASTING LA English DT Article ID APPARENT TEMPERATURE; ERRORS; SULTRINESS AB Because of shortcomings in the current wind chill formulation, which did not consider the metabolic heat generation of the human body, a new formula is proposed for operational implementation. This formula, referred to as the Steadman wind chill, is based on peer-reviewed research including a heat generation and exchange model of an appropriately dressed person for a range of low temperatures and wind speeds. The Steadman wind chill produces more realistic wind chill equivalents than the current NWS formulation. It is easy to determine from tables (calculated by application of a quadratic fit in both U.S. and metric units) with values accurate to within 1 degrees C. C1 NESDIS, NOAA, DOC, Natl Climat Data Ctr,Global Climate Lab, Asheville, NC 28801 USA. La Trobe Univ, Sch Agr Sci, Bundoora, Vic 3083, Australia. RP Quayle, RG (reprint author), NESDIS, NOAA, DOC, Natl Climat Data Ctr,Global Climate Lab, 151 Patton Ave, Asheville, NC 28801 USA. NR 22 TC 19 Z9 19 U1 0 U2 7 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 1998 VL 13 IS 4 BP 1187 EP 1193 DI 10.1175/1520-0434(1998)013<1187:TSWCAI>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200018 ER PT J AU Podobedov, VB Romero, DB Weber, A Rice, JP Schreekala, R Rajeswari, M Ramesh, R Venkatesan, T Drew, HD AF Podobedov, VB Romero, DB Weber, A Rice, JP Schreekala, R Rajeswari, M Ramesh, R Venkatesan, T Drew, HD TI Diagnostics of "colossal" magnetoresistance manganite films by Raman spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID PHASE-DIAGRAM; THIN-FILMS; TEMPERATURE; GROWTH AB Polarized Raman scattering by phonons is used to characterize thin films prepared by laser ablation of La1-xCaxMnO3 targets. It was found that, in the temperature range from 6 to 300 K, phonon spectra of La0.7Ca0.3MnO3 films exhibit observable differences from those in bulk materials (microcrystalline ceramics and single crystals). A significant difference was found in the spectra of "as-grown'' films compared to those annealed in oxygen at 800 degrees C. The observed Raman peaks and their linewidths exhibit an irregular temperature dependence near T-c. A correlation of Raman data with magnetization of the sample was also found. (C) 1998 American Institute of Physics. [S0003-6951(98)03048-4]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Russian Acad Sci, Inst Spect, Troitsk 142092, Moscow Region, Russia. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Podobedov, VB (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Venkatesan, Thirumalai/E-1667-2013 NR 16 TC 37 Z9 37 U1 0 U2 10 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 NOV 30 PY 1998 VL 73 IS 22 BP 3217 EP 3219 DI 10.1063/1.122723 PG 3 WC Physics, Applied SC Physics GA 143MR UT WOS:000077259900013 ER PT J AU Guerrero, HM Cappelletti, RL Neumann, DA Yildirim, T AF Guerrero, HM Cappelletti, RL Neumann, DA Yildirim, T TI Structure and lattice dynamics of K1C60 in the orthorhombic phase: a neutron scattering study SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; POLYMERIZED C-60; RBC60; DIMERS; KC60; STABILITY AB Rietveld refinement of neutron diffraction from a powder sample of K1C60 in the orthorhombic phase using a model having polymeric linking by [2 + 2] cycloaddition of the C-60 molecules yields physically reasonable bond lengths from 1.44 to 1.54 Angstrom between C atoms in the vicinity of the link. Neutron time-of-flight inelastic scattering measurements display a band of vibrations consistent with linking between 10 and 25 meV not present in pure C-60 or in the fee phase of K1C60. Diffuse scattering is accounted for in terms of rotationally disordered C-60 in minority phases and in unlinked boundary regions between polymer grains. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ohio Univ, Dept Phys & Astron, Condensed Matter & Surface Sci Program, Athens, OH 45701 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Autonoma Neuvo Leon, Fac Ciencias FisicoMatemat, San Nicolas de los Garza 66450, Nuevo Leon, Mexico. RP Cappelletti, RL (reprint author), Ohio Univ, Dept Phys & Astron, Condensed Matter & Surface Sci Program, Athens, OH 45701 USA. EM cappltti@helios.phy.ohiou.edu RI yildirim, taner/A-1290-2009 NR 25 TC 9 Z9 9 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 27 PY 1998 VL 297 IS 3-4 BP 265 EP 272 DI 10.1016/S0009-2614(98)01147-6 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 142HZ UT WOS:000077196000016 ER PT J AU Wang, WQ Kumar, A AF Wang, WQ Kumar, A TI A GCM assessment of atmospheric seasonal predictability associated with soil moisture anomalies over North America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VARIABILITY; MODEL; SST; CLIMATE; STATES; TEMPERATURE; PREDICTIONS AB The impact of soil moisture anomalies on the seasonal mean atmospheric predictability over North America is investigated on the basis of a 100-year simulation by an atmospheric general circulation model (AGCM). It is shown that soil moisture anomalies have the smallest persistence during the late spring and summer months, yet the associated near-surface atmospheric climate anomalies are the largest. The causes for this seasonality are traced to the seasonal variation of the surface evaporation and the modulating control of the atmospheric dynamic variability. It is also shown that the dominant spatial modes of interannual soil moisture variability in late spring can have different degrees of interaction with the surface climate. To what extent do initial soil moisture anomalies and their subsequent evolution impact the atmospheric variability? This question is of relevance if the soil moisture anomalies are to be observed and are used as one of the initial conditions in seasonal climate forecast. To investigate this, we carried out additional AGCM experiments for which soil moisture anomalies are initialized as the extreme states from the control simulation. It is found that the relationship between the soil moisture and the near-surface atmospheric anomalies in these additional experiments is similar to those obtained in the control simulation. This leads us to the conclusions that (1) there is a certain potential for seasonal predictability of the atmospheric surface climate anomalies due to interannual variations in the soil moisture, and (2) the effect of the soil moisture anomalies, however, is mostly confined to the near-surface climate variability with little impact on the dynamic variability in the atmosphere, for example, in the upper troposphere. We conclude that atmospheric potential predictability associated with soil moisture anomalies is modest and confined to summer months. Any realization of this predictability depends on correctly observing and initializing large-scale soil moisture anomalies. These conclusions are based on a particular AGCM and its land surface parameterization scheme. More thorough investigations with more sophisticated land surface schemes are certainly warranted. C1 Gen Sci Corp, Camp Springs, MD 20746 USA. NOAA, Natl Ctr Environm Predict, Climate Modeling Branch, Washington, DC 20233 USA. RP Wang, WQ (reprint author), Gen Sci Corp, 5200 Auth Rd,Room 807, Camp Springs, MD 20746 USA. EM wd52ww@sun1.wwb.noaa.gov NR 20 TC 33 Z9 35 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 27 PY 1998 VL 103 IS D22 BP 28637 EP 28646 DI 10.1029/1998JD200010 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 142JB UT WOS:000077196200002 ER PT J AU McCollum, JR Krajewski, WF AF McCollum, JR Krajewski, WF TI Investigations of error sources of the Global Precipitation Climatology Project emission algorithm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MULTICHANNEL MICROWAVE IMAGERY; OCEAN RAIN RATE; PHYSICAL RETRIEVALS; RADIATIVE-TRANSFER; INDEXES AB An error analysis of the Global Precipitation Climatology Project emission algorithm is conducted to identify the major error sources of the algorithm and to quantify the estimation biases resulting from these sources. Several error sources are investigated and uncertainties in spatial rainfall rate variability and freezing level height are identified as the most significant. Spatial rainfall rate variability contributes to beam filling error, and beam filling error is investigated in detail by simulation of brightness temperatures resulting from rainfall rate fields with known spatial variabilities. The algorithm is used to estimate rainfall from the simulated brightness temperatures, and the estimation bias is calculated by comparison of the monthly rainfall estimates with the monthly rainfall used to simulate the brightness temperatures. The final result of the study is the mean monthly multiplicative bias error as a function of the freezing level height and the instantaneous rainfall rate variability. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. Univ Iowa, Dept Civil & Environm Engn, Iowa Inst Hydraul Res, Hydraul Lab 200 B, Iowa City, IA 52242 USA. RP McCollum, JR (reprint author), NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. EM wkrajew@icaen.uiowa.edu NR 22 TC 12 Z9 12 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 27 PY 1998 VL 103 IS D22 BP 28711 EP 28719 DI 10.1029/98JD02580 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 142JB UT WOS:000077196200008 ER PT J AU Harshvardhan Ridgway, W Ramaswamy, V Freidenreich, SM Batey, M AF Harshvardhan Ridgway, W Ramaswamy, V Freidenreich, SM Batey, M TI Spectral characteristics of solar near-infrared absorption in cloudy atmospheres SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOCUMULUS CLOUDS; AIRCRAFT OBSERVATIONS; OPTICAL-PROPERTIES; RADIATION; WATER; CONSTANTS; SURFACE; ALBEDO; FIELDS; MODEL AB Theoretical and experimentally derived estimates of the atmospheric absorption of solar energy in the presence of clouds have been reported to be at variance for quite a long time. A detailed set of near-monochromatic computations of the reflectance, transmittance, and absorptance of a standard midlatitude atmosphere with embedded water clouds is used to identify spectral features in the solar near-infrared that can be utilized to study this discrepancy. The results are framed in terms of the cloud radiative forcing both at the surface and at the top of the atmosphere, and it is shown that water vapor windows are the most sensitive to variations in cloud optical properties and cloud placement in the vertical. The ratio of the cloud radiative forcing at the surface to that at the top of the atmosphere, R, varies from near zero in the band centers at small wavenumbers for high clouds to similar to 1 in the band centers at larger wavenumbers for low clouds and to values in excess of 2 in the water vapor windows at small wavenumbers. The possibility of using measurements from space with the future Moderate Resolution Imaging Spectroradiometer (MODIS) and simultaneous surface measurements is discussed. It is also shown that horizontal inhomogeneities in the cloud layers do not alter appreciably the estimates of the R factor, but areal mean cloud absorption is lower for an inhomogeneous cloud having the same mean liquid water as the corresponding homogeneous cloud. C1 Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN USA. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NASA, Goddard Space Flight Ctr, SM&A Corp, Greenbelt, MD 20771 USA. RP Harshvardhan (reprint author), Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN USA. EM harsh@purdue.edu NR 38 TC 0 Z9 0 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 27 PY 1998 VL 103 IS D22 BP 28793 EP 28799 DI 10.1029/1998JD200013 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 142JB UT WOS:000077196200015 ER PT J AU Oechel, WC Vourlitis, GL Brooks, S Crawford, TL Dumas, E AF Oechel, WC Vourlitis, GL Brooks, S Crawford, TL Dumas, E TI Intercomparison among chamber, tower, and aircraft net CO2 and energy fluxes measured during the Arctic System Science Land-Atmosphere-Ice Interactions (ARCSS-LAII) Flux Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE; OPEN-PATH; TUNDRA ECOSYSTEMS; EDDY-COVARIANCE; CLIMATE-CHANGE; BROOKS-RANGE; ALASKA; WATER; VAPOR; HEAT AB Measurements of net ecosystem CO2 exchange (NEE) and energy balance were made using chamber-, tower-, and aircraft-based measurement techniques in Alaskan arctic tundra ecosystems during the 1994-1995 growing seasons (June-August). One of our objectives was to quantify the interrelationships between the NEE and the energy balance measurements made from different sampling techniques. Qualitative and quantitative intercomparisons revealed that on average the correspondence between the mass and energy fluxes measured by these sampling methods was good despite potential spatial and temporal mismatches in sampling scale. Quantitative comparisons using least squares linear regression analyses with the tower-based measurements of NEE as the independent variable indicate that the chamber- and aircraft-based NEE measurements were generally lower relative to the tower-based measurements (slope = 0.76-0.86). Similarly, tower-aircraft comparisons of latent (L-e) and sensible (H) heat exchange indicated that the aircraft-based measurements were lower than the tower-based measurements (slope = 0.72-0.80). Qualitative comparisons, however, indicate that the correspondence among the chamber-, tower-: and aircraft-measured fluxes varied both seasonally and interannually, suggesting the lack of a consistent bias between the sampling techniques. The results suggest that differences observed between the chamber, tower, and aircraft flux measurements were primarily due to the failure to account for the spatial distribution of surface types in the tower and aircraft sampling footprint, problems involved in the comparison of temporal and spatial averages, and temporal (e.g., seasonal and interannual) variance in rates of mass and energy flux for a given point. Other potential sources of variance include the underestimation of nocturnal NEE by the tower-based eddy covariance system, and the periodic occurrence of an elevated CO2 plume in the atmosphere over the Prudhoe Bay oil field. Even with these potential sources of variation, the results reveal that the various methods,give comparable estimates of NEE and energy flux within a range of temporal or spatial variability. C1 San Diego State Univ, Dept Biol, Global Change Res Grp, San Diego, CA 92182 USA. Calif Sta San Marcos, Biol Program Area, San Marcos, TX USA. NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP Oechel, WC (reprint author), San Diego State Univ, Dept Biol, Global Change Res Grp, 5500 Campanile Dr, San Diego, CA 92182 USA. EM oechel@sunstroke.sdsu.edu RI Oechel, Walter/F-9361-2010; Dumas, Edward/C-6669-2016 OI Oechel, Walter/0000-0002-3504-026X; Dumas, Edward/0000-0002-9154-9052 NR 52 TC 46 Z9 49 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 27 PY 1998 VL 103 IS D22 BP 28993 EP 29003 DI 10.1029/1998JD200015 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 142JB UT WOS:000077196200032 ER PT J AU Murphy, DM Thomson, DS Mahoney, TMJ AF Murphy, DM Thomson, DS Mahoney, TMJ TI In situ measurements of organics, meteoritic material, mercury, and other elements in aerosols at 5 to 19 kilometers SO SCIENCE LA English DT Article ID CONDENSATION NUCLEI; PARTICLE FORMATION; LOWER STRATOSPHERE; TROPOSPHERE; ORIGIN; METALS; DUST AB In situ measurements of the chemical composition of individual aerosol particles at altitudes between 5 and 19 kilometers reveal that upper tropospheric aerosols often contained more organic material than sulfate. Although stratospheric aerosols primarily consisted of sulfuric acid and water, many also contained meteoritic material. Just above the tropopause, small amounts of mercury were found in over half of the aerosol particles that were analyzed. Overall, there was tremendous variety in aerosol composition. One measure of this diversity is that at Least 45 elements were detected in aerosol particles. These results have wide implications for the complexity of aerosol sources and chemistry. They also offer possibilities for understanding the transport of atmospheric aerosols. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Murphy, DM (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM murphyd@al.noaa.gov RI Murphy, Daniel/J-4357-2012 OI Murphy, Daniel/0000-0002-8091-7235 NR 48 TC 421 Z9 425 U1 2 U2 52 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 27 PY 1998 VL 282 IS 5394 BP 1664 EP 1669 DI 10.1126/science.282.5394.1664 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 143GJ UT WOS:000077246600035 ER PT J AU Schwab, DJ Beletsky, D AF Schwab, DJ Beletsky, D TI Propagation of Kelvin waves along irregular coastlines in finite-difference models SO ADVANCES IN WATER RESOURCES LA English DT Article DE hydrodynamic modeling; finite difference; Kelvin wave AB In this paper, we examine the behavior of internal Kelvin waves on anf-plane in finite-difference models using the Arakawa C-grid. The dependence of Kelvin wave phase speed on offshore grid resolution and propagation direction relative to the numerical grid is illustrated by numerical experiments for three different geometries: (1) Kelvin wave propagating along a straight coastline; (2) Kelvin wave propagating at a 45 degrees angle to the numerical grid along a stairstep coastline with stairstep size equal to the grid spacing; (3) Kelvin wave propagating at a 45 degrees angle to the numerical grid along a coarse resolution stairstep coastline with stairstep size greater than the grid spacing. It can be shown theoretically that the phase speed of a Kelvin wave propagating along a straight coastline on an Arakawa C-grid is equal to the analytical inviscid wave speed and is not dependent on offshore grid resolution. However, we found that finite-difference models considerably underestimate the Kelvin wave phase speed when the wave is propagating at an angle to the grid and the grid spacing is comparable with the Rossby deformation radius. In this case, the phase speed converges toward the correct value only as grid spacing decreases well below the Rossby radius. A grid spacing of one-fifth the Rossby radius was required to produce results for the stairstep boundary case comparable with the straight coast case. This effect does not appear to depend on the resolution of the coastline, but rather on the direction of wave propagation relative to the grid. This behavior is important for modeling internal Kelvin waves in realistic geometries where the Rossby radius is often comparable with the grid spacing, and the waves propagate along irregular coastlines. (C) 1998 Published by Elsevier Science Limited. All rights reserved. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. RP Schwab, DJ (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. RI Schwab, David/B-7498-2012; OI Beletsky, Dmitry/0000-0003-4532-0588 NR 7 TC 10 Z9 11 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD NOV 26 PY 1998 VL 22 IS 3 BP 239 EP 245 DI 10.1016/S0309-1708(98)00015-3 PG 7 WC Water Resources SC Water Resources GA 146XP UT WOS:000077458800004 ER PT J AU Munroe, TA Amaoka, K AF Munroe, TA Amaoka, K TI Symphurus hondoensis Hubbs, 1915, a valid species of Western Pacific tonguefish (Pleuronectiformes : Cynoglossidae) SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE Symphurus hondoensis; redescription; valid species; Cynoglossidae AB Symphurus hondoensis Hubbs, 1915, originally described only from the holotype taken in 390-542 m in Suruga Bay Japan, has long been considered a junior synonym of S. strictus Gilbert, 1905, known from waters off Hawaii, Japan, the Philippine Islands, and South Africa. Based on new information from the holotype and a specimen recently captured from deep waters (789-815 m) off Amami-Oshima Island, southern Japan, S. hondoensis is now established as a valid species. Symphurus hondoensis is unique among congeners in having the combination of a 1-2-3 pattern of interdigitation of proximal dorsal pterygiophopes and neural spines, 10 abdominal vertebrae, 14 caudal-fin rays, 111-113 dorsal-fin rays, 95 anal-fin rays, 59 total vertebrae, 105-106 scales in longitudinal series, blind side nearly as darkly pigmented as the ocular surface, and a black peritoneum. Recognition of S. hondoensis increases the number of described species of Symphurus in waters off Japan to three (S. orientalis Bleeker, S. strictus, and S. hondoensis), with at least one more undescribed species occurring in deepwater hydrothermal vent areas off southern Japan. C1 Natl Museum Nat Hist, Natl Marine Fisheries Serv Natl Systemat Lab, Washington, DC 20560 USA. Hokkaido Univ, Fac Fisheries, Lab Marine Zool, Hakodate, Hokkaido 041, Japan. RP Munroe, TA (reprint author), Natl Museum Nat Hist, Natl Marine Fisheries Serv Natl Systemat Lab, MRC-153, Washington, DC 20560 USA. NR 21 TC 10 Z9 10 U1 0 U2 0 PU ICHTHYOLOGICAL SOC JAPAN PI TOKYO PA BUSINESS CENTER ACADEMIC SOC JAPAN, 5-16-9 HONKOMAGOME, BUNKYO-KU, TOKYO, 113, JAPAN SN 1341-8998 J9 ICHTHYOL RES JI Ichthyol. Res. PD NOV 26 PY 1998 VL 45 IS 4 BP 385 EP 391 DI 10.1007/BF02725191 PG 7 WC Zoology SC Zoology GA 160ZX UT WOS:000078264200007 ER PT J AU Kunt, TA McAvoy, TJ Cavicchi, RE Semancik, S AF Kunt, TA McAvoy, TJ Cavicchi, RE Semancik, S TI Optimization of temperature programmed sensing for gas identification using micro-hotplate sensors SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE optimization; programmed sensing; micro-hotplate sensors AB Micro-hotplate chemical gas sensors, such as those being developed at the National Institute of Standards and Technology (NIST) by micromachining Si, can be operated in a temperature-pulsed mode, due to their small size and mass. In the temperature-pulsed mode of operation, different gases give different dynamic responses (i.e. signatures) depending on the temperature program used. In this paper a new methodology is presented to optimize the operation of micro-hotplate gas sensors for discriminating volatile organic compounds at a fixed concentration, while minimizing the detection time. The extension of the methodology to cases where concentrations vary is currently under investigation. The Wavelet Network method is applied to accurately predict the sensor's response for a given temperature profile. Once a dynamic model is obtained, it is used for off-line optimization of the temperature profile, i.e. the maximization of the difference between two gas signatures. The difference between two response curves was initially measured by a metric based on the Euclidean distance. This metric was then modified using the Haar wavelet transformation. The methodology was implemented in a case study in which either methanol or ethanol had to be detected in air, but the methodology is generic, and it can be applied to any two gases. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Maryland, Dept Chem Engn, Chem Engn & Inst Syst Res, Syst Res Inst, College Pk, MD 20742 USA. NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP McAvoy, TJ (reprint author), Univ Maryland, Dept Chem Engn, Chem Engn & Inst Syst Res, Syst Res Inst, AV Williams Bldg 115, College Pk, MD 20742 USA. EM atkunt@eng.umd.edu; mcavoy@isr.umd.edu NR 32 TC 87 Z9 89 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD NOV 26 PY 1998 VL 53 IS 1-2 BP 24 EP 43 DI 10.1016/S0925-4005(98)00244-5 PG 20 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 153XL UT WOS:000077858600005 ER PT J AU Huang, PH AF Huang, PH TI Humidity standards for low level water vapor sensing and measurements SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE intercomparison; moisture standards; permeation-diffusion-tube AB An intercomparison between the two most widely used types of low level humidity standards constituting a permeation-tube standard and an evaporation-diffusion standard is presented. Using a precision chilled-mirror hygrometer as a transfer standard, frost-point temperatures of nitrogen-water-vapor mixtures produced by the standard generators are measured in the water vapor concentration range of 5-70 nmol mol(-1). Measured differences between the standard generators are found to be within the standards' expanded uncertainties for moisture content of greater than approximate to 15 nmol mol(-1). Below 15 nmol mol(-1), the differences are greater than the combined uncertainties of the standard generators. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Huang, PH (reprint author), Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. NR 3 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD NOV 26 PY 1998 VL 53 IS 1-2 BP 125 EP 127 DI 10.1016/S0925-4005(98)00313-X PG 3 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 153XL UT WOS:000077858600017 ER PT J AU Vanderah, DJ Meuse, CW Silin, V Plant, AL AF Vanderah, DJ Meuse, CW Silin, V Plant, AL TI Synthesis and characterization of self-assembled monolayers of alkylated 1-thiahexa(ethylene oxide) compounds on gold SO LANGMUIR LA English DT Article ID SURFACE-PLASMON RESONANCE; SUPPORTED LIPID LAYERS; STRUCTURAL CHARACTERIZATION; WETTING PROPERTIES; MEMBRANES; BILAYERS; SPECTROSCOPY; KINETICS; ATTACHMENT; BIOSENSOR AB Self-assembled monolayers (SAMs) of a series of novel linear thiols containing a 1-thiahexa(ethylene oxide) (THEO) moiety, i.e., HS(CH2CH2O)(6)R, where R = C10H21, C10D21, C18H37, and C18D37, were prepared on polycrystalline gold (Au) and characterized by reflection absorption infrared spectroscopy (RAIRS), spectroscopic ellipsometry, surface plasmon resonance (SPR), and contact angle measurements. The SAMs are hydrophobic with contact angles, theta(a) (H2O), of 108 degrees-109 degrees for all surfaces. For all compounds, our data provide evidence for well-ordered monolayers in which the THEO moiety is arranged in a 7/2 helix oriented normal to the substrate. The alkyl group conformation and tilt are similar to the corresponding n-alkanethiol SAMs. C1 Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Georgetown Univ, Washington, DC 20057 USA. RP Vanderah, DJ (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 40 TC 50 Z9 50 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 24 PY 1998 VL 14 IS 24 BP 6916 EP 6923 DI 10.1021/la9806451 PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 142EZ UT WOS:000077188100021 ER PT J AU Hunter, EP Lias, SG Rooney, CM Winstead, JL Liebman, JF AF Hunter, EP Lias, SG Rooney, CM Winstead, JL Liebman, JF TI "Thermochemical mimicry" of phenyl and vinyl groups: can it be extended to charged species? SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE enthalpy of formation; ionization energies; proton affinities; substituent effects AB By examination of a set of recently evaluated proton affinities, the thermochemical mimicry of phenyl and vinyl derivatives is shown not to apply to charged species. (C) 1998 Elsevier Science B.V. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland Baltimore Cty, Dept Chem & Biochem, Baltimore, MD 21250 USA. RP Hunter, EP (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 9 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 EI 1873-2798 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD NOV 23 PY 1998 VL 179 BP 261 EP 266 DI 10.1016/S1387-3806(98)14068-X PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 140RD UT WOS:000077101400027 ER PT J AU Wiegand, S Briggs, ME Sengers, JMHL Kleemeier, M Schroer, W AF Wiegand, S Briggs, ME Sengers, JMHL Kleemeier, M Schroer, W TI Turbidity, light scattering, and coexistence curve data for the ionic binary mixture triethyl n-hexyl ammonium triethyl n-hexyl borate in diphenyl ether SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIQUID PHASE-TRANSITION; CRITICAL-BEHAVIOR; CRITICAL-POINT; ETHYLAMMONIUM NITRATE; COULOMBIC CRITICALITY; CRITICAL EXPONENT; CONSOLUTE POINT; FLUIDS; SYSTEM; CYCLOHEXANE AB We report turbidity, Light scattering, and coexistence curve data for a solution of triethyl n-hexyl ammonium triethyl n-hexyl borate in diphenylether. We recently reported that the present sample shows much higher turbidity than that of K. S. Zhang, M. E. Briggs, R. W. Gammon, and J. M. H. Levelt Sengers [J. Chem. Phys. 109, 4533 (1998)] for an earlier sample. An analysis of the data shows that nonclassical critical behavior is favored in the reduced temperature range from 10(-5) to 10(-2). At fixed reduced temperature, the correlation length is about twice as large as that of the previous sample. The correlation length amplitude calculated from the fit is 1.4 nm+/-0.1 nm. A detailed data analysis points out the limitations of turbidity measurements far away from the critical paint. The intensity of scattered light was measured at 90 degrees. Multiple scattering is relevant in the wider vicinity of the critical point and was corrected for by a Monte Carlo simulation method. An Ising-type exponent for the correlation length was obtained: nu = 0.641 +/- 0.003, and the amplitude of the correlation length xi(0)=1.34 nm+/-0.01 nm agrees with that of the turbidity experiment. Mean-held behavior can be ruled out. The refractive indices of coexisting phases were measured in the reduced temperature range from t=10(-4) to 0.04. These measurements disagree with results reported by R. R. Singh and K. S. Fitter [J. Chem. Phys. 92, 6775 (1990)]. The present data lead to an exponent beta=0.34+/-0.01, close to the Ising value. The coexistence curve is much narrower than that of Singh and Fitter. Crossover could not be detected in any of the experiments. Two-scale-factor universality could be confirmed for this and another ionic system within the experimental uncertainty. (C) 1998 American Institute of Physics. [S0021-9606(98)50344-3]. C1 Univ Bremen, Inst Phys & Anorgan Chem, D-28334 Bremen, Germany. NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Wiegand, S (reprint author), NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Wiegand, Simone/G-6257-2013 OI Wiegand, Simone/0000-0001-6333-1956 NR 41 TC 73 Z9 74 U1 1 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 1998 VL 109 IS 20 BP 9038 EP 9051 DI 10.1063/1.477574 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139QE UT WOS:000077039900037 ER PT J AU Cruz, FC Young, BC Bergquist, JC AF Cruz, FC Young, BC Bergquist, JC TI Diode-pumped Nd : FAP laser at 1.126 mu m: a possible local oscillator for a Hg+ optical frequency standard SO APPLIED OPTICS LA English DT Article ID QUANTUM JUMPS; CAVITY; ION AB We report the efficient operation of a continuous-wave, single-frequency, diode-pumped Nd:FAP laser at 1.126 mu m. When frequency quadrupled, such a laser might be used as a local oscillator for an optical frequency standard based on the single-photon S-2(1/2)-D-2(5/2) electric quadrupole transition of a trapped and laser-cooled Hg-199(+) ion. Since the frequencies of the atomic transition and the laser are harmonically related, this scheme helps to simplify the measurement of the S-D clock transition frequency by a phase-coherent chain to the cesium primary frequency standard. OCIS codes: 020.7010, 140.3480, 140.3580, 190.4160, 300.6520. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Univ Estadual Campinas, Inst Fis Gleb Wataghin, CP 6165, BR-13083970 Campinas, SP, Brazil. EM byoung@boulder.nist.gov RI Cruz, Flavio/A-6346-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Cruz, Flavio/0000-0003-3995-7910; NR 25 TC 1 Z9 1 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 1998 VL 37 IS 33 BP 7801 EP 7804 DI 10.1364/AO.37.007801 PG 4 WC Optics SC Optics GA 138ZQ UT WOS:000077003300021 PM 18301621 ER PT J AU Owen, TW Gallo, KP Elvidge, CD Baugh, KE AF Owen, TW Gallo, KP Elvidge, CD Baugh, KE TI Using DMSP-OLS light frequency data to categorize urban environments associated with US climate observing stations SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID CITY LIGHTS AB An approach is presented for characterizing the urban environment surrounding 1221 US Historical Climatology Network (US HCN) stations using light frequency data from the Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) sensor. Each grid cell of the DMSP-OLS data was thresholded into urban, suburban and rural categories. Categorized cell groups within 15km of each US HCN station were input into a decision logic to categorize the station. The station categorization was compared with existing and derived categorizations using station metadata and 1990 Census Bureau population density data. C1 NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. NOAA, Off Res & Applicat, Washington, DC 20233 USA. Univ Nevada Syst, Desert Res Inst, Reno, NV 89506 USA. NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. RP Owen, TW (reprint author), NOAA, Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. RI Elvidge, Christopher/C-3012-2009; Gallo, Kevin P./F-5588-2010 NR 12 TC 42 Z9 45 U1 0 U2 15 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 1998 VL 19 IS 17 BP 3451 EP 3456 PG 6 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 151AN UT WOS:000077698900019 ER PT J AU Nunnermacker, LJ Imre, D Daum, PH Kleinman, L Lee, YN Lee, JH Springston, SR Newman, L Weinstein-Lloyd, J Luke, WT Banta, R Alvarez, R Senff, C Sillman, S Holdren, M Keigley, GW Zhou, X AF Nunnermacker, LJ Imre, D Daum, PH Kleinman, L Lee, YN Lee, JH Springston, SR Newman, L Weinstein-Lloyd, J Luke, WT Banta, R Alvarez, R Senff, C Sillman, S Holdren, M Keigley, GW Zhou, X TI Characterization of the Nashville urban plume on July 3 and July 18, 1995 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; GAS-PHASE PEROXIDES; NONENZYMATIC METHOD; CARBONYL-COMPOUNDS; HYDROGEN-PEROXIDE; RURAL SITE; OZONE; NITROGEN; AIRCRAFT; ATLANTA AB This paper reports results from the Southern Oxidants Study field campaign designed to characterize the formation and distribution of ozone and related species in the Nashville urban region, Data from several airborne platforms as well as surface observations on July 3 and 18 are examined to gain insight into the factors that control O-3 formation rates and concentrations in the regional plumes. On both days, well-defined urban and power plant plumes were sampled. Utilizing both aircraft and surface data, a detailed kinetic analysis of the chemical evolution of the urban plume is performed to derive NOx lifetime, ozone production efficiency, OH concentration, HNO3 dry deposition rate, and the relative importance of natural and anthropogenic hydrocarbons to O-3 production. Analysis of the urban plume data revealed a very active photochemical system (average [OH] similar to 1.2 x 10(7) molecules cm(-3)) which consumed 50% of the NOx within approximately 2 hours, at an ozone production efficiency of 2.5 to 4 molecules for each molecule of NOx. Anthropogenic hydrocarbons provided approximately 44% of the fuel for ozone production by the urban plume. The dry deposition rate for HNO3 in the urban plume was estimated to be of the order of 5 to 7 cm s(-1). C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. NOAA, Environm Res Lab, Boulder, CO 80307 USA. Battelle Columbus, Atmospher Sci & Appl Technol, Columbus, OH 43201 USA. NOAA, Air Resources Lab, Silver Spring, MD USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. SUNY Coll Old Westbury, Dept Chem Phys, Old Westbury, NY 11568 USA. New York State Dept Hlth, Albany, NY 12201 USA. RP Nunnermacker, LJ (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, POB 5000, Upton, NY 11973 USA. EM lindan@bnl.gov RI Senff, Christoph/I-2592-2013; Banta, Robert/B-8361-2008; Alvarez, Raul/I-4879-2013; Luke, Winston/D-1594-2016; OI Luke, Winston/0000-0002-1993-2241; Sillman, Sanford/0000-0001-6250-1191 NR 38 TC 56 Z9 59 U1 1 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 1998 VL 103 IS D21 BP 28129 EP 28148 DI 10.1029/98JD01961 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 140GF UT WOS:000077078700011 ER PT J AU Brasseur, GP Hauglustaine, DA Walters, S Rasch, PJ Muller, JF Granier, C Tie, XX AF Brasseur, GP Hauglustaine, DA Walters, S Rasch, PJ Muller, JF Granier, C Tie, XX TI MOZART, a global chemical transport model for ozone and related chemical tracers 1. Model description SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID GENERAL-CIRCULATION MODEL; 3-DIMENSIONAL MODEL; MIDDLE ATMOSPHERE; TROPOSPHERIC CHEMISTRY; LOWER STRATOSPHERE; CLIMATE MODEL; SIMULATION; EMISSIONS; NOX; PARAMETERIZATION AB We present a new global three-dimensional chemical-transport model (called MOZART) developed in the framework of the NCAR Community Climate Model (CCM) and aimed at studying the distribution and budget of tropospheric ozone and its precursors. The model, developed with a horizontal resolution of 2.8 degrees in longitude and latitude, includes 25 levels in the vertical between the Earth's surface and an upper boundary located at approximately 35 km altitude. In its present configuration the model calculates the global distribution of 56 chemical constituents with a timestep of 20 min, and accounts for surface emission and deposition, large-scale advective transport, subscale convective and boundary layer exchanges, chemical and photochemical transformations, as well as wet scavenging. Transport is simulated "off line" from CCM with dynamical variables provided every 3 hours from preestablished history tapes. Advection is calculated using the semi-Lagrangian transport scheme [Rasch and Williamson, 1990] developed for the MATCH model of Rasch et al. [1997]. Convective and boundary layer transports are expressed according to Hack [1994] and Holtslag and Boville [1993], respectively. A detailed evaluation of the model results is provided in a companion paper [Hauglustaine et al., this issue]. An analysis of the spatial and temporal variability in the chemical fields predicted by the model suggests that regional events such as summertime ozone episodes in polluted areas can be simulated by MOZART. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Paris 06, CNRS, Serv Aeron, F-75252 Paris 05, France. Inst Aeron Spatiale Belgique, B-1180 Brussels, Belgium. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Brasseur, GP (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM dh@aero.jussieu.fr RI Granier, Claire/D-5360-2013 OI Granier, Claire/0000-0001-7344-7995 NR 107 TC 294 Z9 304 U1 1 U2 30 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 1998 VL 103 IS D21 BP 28265 EP 28289 DI 10.1029/98JD02397 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 140GF UT WOS:000077078700020 ER PT J AU Callis, LB Natarajan, M Evans, DS Lambeth, JD AF Callis, LB Natarajan, M Evans, DS Lambeth, JD TI Solar atmospheric coupling by electrons (SOLACE) 1. Effects of the May 12, 1997 solar event on the middle atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THERMOSPHERIC NITRIC-OXIDE; CORONAL MASS EJECTIONS; HELIOGRAPHIC LATITUDES; REACTIVE NITROGEN; OZONE DEPLETION; COOLING RATES; PROTON EVENTS; ODD NITROGEN; WIND; STRATOSPHERE AB An analysis is carried out of the effects on middle atmospheric NOy and O-3 of a coronal mass ejection (CME) event which occurred on May 12, 1997, and which is coupled with observed solar wind fluctuations. Observations of electron fluxes by instruments aboard the SAMPEX and NOAA 12 satellites indicate large enhancements of magnetospheric electron fluxes occurring with the arrival of the high-speed solar wind. Calculations suggest that significant formation rates of NOy should occur in the mesosphere and the lower thermosphere at mid to high latitudes. Halogen Occultation Experiment (HALOE) NO observations reveal increases of more than an order of magnitude between 85 and 120 km in both hemispheres within 1-2 days after the electron flux increases. Two dimensional chemical transport simulations were carried out to assess the fate of the NO, increases. Northern hemispheric increases were lost to photochemical destruction shortly after the event ended. Southern hemispheric increases were transported in part into the stratosphere by advective descent. By October 1997, high-latitude NOy increases of 20-40% were calculated near 25 km leading to O-3 reductions of up to approximate to 20% when compared to a simulation with no electron precipitation. A solar atmospheric coupling by electrons precipitating from the outer trapping and auroral regions of the magnetosphere, and which affects middle atmospheric NO, is clearly demonstrated by the observations alone. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA 23666 USA. NOAA, Space Environm Ctr, Boulder, CO USA. RP Callis, LB (reprint author), NASA, Langley Res Ctr, Mail Stop 410B, Hampton, VA 23681 USA. EM lbc@jaguar.larc.nasa.gov NR 49 TC 40 Z9 40 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 1998 VL 103 IS D21 BP 28405 EP 28419 DI 10.1029/98JD02408 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 140GF UT WOS:000077078700027 ER PT J AU Kitade, S Ochiai, N Takahashi, Y Noda, I Matsushita, Y Karim, A Nakatani, AI Kim, HD Han, CC AF Kitade, S Ochiai, N Takahashi, Y Noda, I Matsushita, Y Karim, A Nakatani, AI Kim, HD Han, CC TI Lamellar orientation of diblock copolymer solutions under steady shear flow SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; TRIBLOCK COPOLYMERS; UNIDIRECTIONAL SHEAR; MORPHOLOGY; POLYSTYRENE; ALIGNMENT; RHEOLOGY; STYRENE; PLANE; MELTS AB The steady shear rate dependence of the structure of two poly(styrene-d(8)-b-2-vinylpyridine)s in alpha-chloronaphthalene, a common good solvent, was measured by small-angle neutron scattering (SANS) in a couette flow cell geometry in the ordered state, in which the solutions assume a lamellar structure (randomly oriented grains). SANS measurements revealed that steady shear flow induces macroscopic lamellar orientation at certain characteristic shear rates for the higher molecular weight sample (M-w = 3.6 x 10(5)). Lamellar normals are preferentially oriented along the vorticity direction at high shear rates. However, no shear effect was observed for the low molecular weight sample (M-w = 2.0 x 10(5)). C1 Nagoya Univ, Grad Sch Engn, Dept Appl Chem, Nagoya, Aichi 4648603, Japan. Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, Naka, Ibaraki 3191106, Japan. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Nagoya Univ, Ctr Integrated Res Sci & Engn, Nagoya, Aichi 4648603, Japan. NR 23 TC 22 Z9 22 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD NOV 17 PY 1998 VL 31 IS 23 BP 8083 EP 8090 DI 10.1021/ma971470p PG 8 WC Polymer Science SC Polymer Science GA 141MM UT WOS:000077147800013 ER PT J AU Steel, AB Herne, TM Tarlov, MJ AF Steel, AB Herne, TM Tarlov, MJ TI Electrochemical quantitation of DNA immobilized on gold SO ANALYTICAL CHEMISTRY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; METAL-COMPLEXES; THIOL MONOLAYERS; POLYMER-FILMS; CYTOCHROME-C; HYBRIDIZATION; PROBES; ARRAYS; INTERCALATION; SPECTROSCOPY AB We have developed an electrochemical method to quantify the surface density of DNA immobilized on gold. The surface density of DNA, more specifically the number of nucleotide phosphate residues, is calculated from the amount of cationic redox marker measured at the electrode surface. DNA was immobilized on gold by forming mixed monolayers of thiol-derivitized, single-stranded oligonucleotide and 6-mercapto-1-hexanol. The saturated amount of charge-compensating redox marker in the DNA monolayer, determined using chronocoulometry, is directly proportional to the number of phosphate residues and thereby the surface density of DNA. This method permits quantitative determination of both single- and double-stranded DNA at electrodes. Surface densities of single-stranded DNA were precisely varied in the range of(1-10) x 10(12) molecules/cm(2), as determined by the electrochemical method, using mixed monolayers. We measured the hybridization efficiency of immobilized single-stranded DNA to complementary strands as a function of the immobilized DNA surface density and found that it exhibits a maximum with increasing surface density. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Steel, AB (reprint author), Gene Log Genom Co, Gaithersburg, MD 20878 USA. NR 43 TC 877 Z9 888 U1 17 U2 173 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 15 PY 1998 VL 70 IS 22 BP 4670 EP 4677 DI 10.1021/ac980037q PG 8 WC Chemistry, Analytical SC Chemistry GA 138ZU UT WOS:000077003600004 PM 9844566 ER PT J AU MacCrehan, WA Jensen, JS Helz, GR AF MacCrehan, WA Jensen, JS Helz, GR TI Detection of sewage organic chlorination products that are resistant to dechlorination with sulfite SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACIDS AB Most of the 36 billion gal of treated sewage wastewater discharged daily into the environment in the United States is disinfected via chlorination. To minimize toxicity, dechlorination with sulfite or sulfur dioxide is often performed. Although dechlorination is considered instantaneous and complete, several studies have found residual toxicity of chlorinated/dechlorinated effluent to aquatic life. We investigated chlorination/dechlorination of the organic nitrogen components of sewage wastewater using both iodometric titration and a novel LC method. For LC, a postcolumn reaction with iodide rendered submicromolar chloramine concentrations detectable with amperometry. Using a gradient-elution LC separation, the retention and dechlorination behavior of a suite of model amines was determined, representing primary and secondary aliphatic, peptide, and protein-N. Chlorination/dechlorination experiments on freshly collected, tertiary-treated wastewater showed a fraction of the organic N-chloramines are dechlorinated slowly by sulfite with half-lives of >20 min. Chromatographic retention and kinetic behavior of the sewage N-chloramines was consistent with the behavior of the model peptides and proteins. Proteolytic hydrolysis markedly increased the "peptide" fraction observed upon chlorination of the wastewater. These results suggest that peptides a nd proteins contribute to slow dechlorination of sewage and may be a factor in the toxicity noted for chlorine-disinfected wastewater. C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Chem & Biochem, Water Resources Res Ctr, College Pk, MD 20742 USA. RP MacCrehan, WA (reprint author), NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RI Helz, George/D-1449-2010 NR 22 TC 19 Z9 20 U1 0 U2 5 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 15 PY 1998 VL 32 IS 22 BP 3640 EP 3645 DI 10.1021/es980101l PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 138RQ UT WOS:000076986800029 ER PT J AU Kushner, PJ Held, IM AF Kushner, PJ Held, IM TI A test, using atmospheric data, of a method for estimating oceanic eddy diffusivity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SATELLITE ALTIMETRY; TRANSPORTS; EDDIES; MODELS; HEAT AB G. Holloway has proposed a simple method to estimate the effective horizontal eddy diffusivity for oceanic tracers using satellite measurements of sea-surface height variability. In this method, the diffusivity is assumed to scale as the r.m.s. eddy geostrophic streamfunction. This method should apply analogously in an atmospheric context, in which the energetic eddies are well resolved in data sets and models, and in which both the effective diffusivity and tracer fluxes can be directly calculated. We evaluate Holloway's method using lower-tropospheric daily atmospheric reanalysis data, and find that at a given height the method succesfully yields estimates of the divergent part of the atmospheric sensible heat flux, to within a fairly uniform scaling factor. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Kushner, PJ (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. RI Kushner, Paul/H-6716-2016 OI Kushner, Paul/0000-0002-6404-4518 NR 11 TC 22 Z9 22 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 15 PY 1998 VL 25 IS 22 BP 4213 EP 4216 DI 10.1029/1998GL900142 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 139GH UT WOS:000077019300028 ER PT J AU Peterson, TC Easterling, DR Karl, TR Groisman, P Nicholls, N Plummer, N Torok, S Auer, I Boehm, R Gullett, D Vincent, L Heino, R Tuomenvirta, H Mestre, O Szentimrey, T Salinger, J Forland, EJ Hanssen-Bauer, I Alexandersson, H Jones, P Parker, D AF Peterson, TC Easterling, DR Karl, TR Groisman, P Nicholls, N Plummer, N Torok, S Auer, I Boehm, R Gullett, D Vincent, L Heino, R Tuomenvirta, H Mestre, O Szentimrey, T Salinger, J Forland, EJ Hanssen-Bauer, I Alexandersson, H Jones, P Parker, D TI Homogeneity adjustments of in situ atmospheric climate data: A review SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE homogeneity; climate data; data adjustment techniques; metadata ID AIR-TEMPERATURE VARIATIONS; SURFACE-TEMPERATURE; UNITED-STATES; TIME-SERIES; PRECIPITATION DATA; TRENDS; DISCONTINUITIES; AUSTRALIA; ACCURACY; MINIMUM AB Long-term in situ observations are widely used in a variety of climate analyses. Unfortunately, most decade- to century-scale time series of atmospheric data have been adversely impacted by inhomogeneities caused by, for example, changes in instrumentation, station moves, changes in the local environment such as urbanization, or the introduction of different observing practices like a new formula for calculating mean daily temperature or different observation times. If these inhomogeneities are not accounted for properly, the results of climate analyses using these data on be erroneous. Over the last decade, many climatologists have put a great deal of effort into developing techniques to identify inhomogeneities and adjust climatic time series to compensate for the biases produced by the inhomogeneities. It is important for users of homogeneity-adjusted data to understand how the data were adjusted and what impacts these adjustments are likely to make on their analyses. And it is important for developers of homogeneity-adjusted data sets to compare readily the different techniques most commonly used today. Therefore, this paper reviews the methods and techniques developed for homogeneity adjustments and describes many different approaches and philosophies involved in adjusting in situ climate data. (C) 1998 Royal Meteorological Society. C1 NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. Bur Meteorol, Melbourne, Vic, Australia. Univ Melbourne, Sch Earth Sci, Melbourne, Vic, Australia. Cent Inst Meteorol & Geodynam, Vienna, Austria. Environm Canada, Climate Res Branch, Downsview, ON, Canada. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Meteo France, SCEM, CBD, Toulouse, France. Hungarian Meteorol Serv, Budapest, Hungary. Natl Inst Water & Atmospher Res Ltd, Auckland, New Zealand. Norwegian Meteorol Inst, Oslo, Norway. Swedish Meteorol & Hydrol Inst, S-60176 Norrkoping, Sweden. Univ E Anglia, Climat Res Unit, Norwich NR4 7TJ, Norfolk, England. Meteorol Off, Hadley Ctr, Bracknell, Berks, England. RP Peterson, TC (reprint author), NOAA, Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. RI Jones, Philip/C-8718-2009; Nicholls, Neville/A-1240-2008 OI Jones, Philip/0000-0001-5032-5493; NR 80 TC 442 Z9 467 U1 4 U2 45 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 1998 VL 18 IS 13 BP 1493 EP 1517 DI 10.1002/(SICI)1097-0088(19981115)18:13<1493::AID-JOC329>3.0.CO;2-T PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 138HW UT WOS:000076967300007 ER PT J AU Wang, YC Christophorou, LG Verbrugge, JK AF Wang, YC Christophorou, LG Verbrugge, JK TI Effect of temperature on electron attachment to and negative ion states of CCl2F2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CROSS-SECTIONS; CHLOROFLUOROMETHANES; SCATTERING; ENERGIES; IMPACT; CHLOROMETHANES; COEFFICIENTS; CF2CL2; CCL3F; CF4 AB The effect of temperature on electron attachment to dichlorodifluoromethane (CCl2F2) has been investigated for temperatures up to 500 K and for mean-electron energies from thermal to 1.0 eV using an electron swarm method. The measurements were made in mixtures of CCl2F2 with nitrogen. The electron attachment rate constant increases with temperature over the entire temperature and mean-electron energy range investigated. The variation of the thermal value of the electron attachment rate constant with temperature compares well with earlier measurements of this quantity and shows an increase by a factor of 10 when the temperature is raised from 300 to 500 K. From a comparison of published data on the electron affinity, electron attachment using the swarm method, electron attachment using the electron beam method, electron scattering, electron transmission, indirect electron scattering, and related calculations, the lowest negative ion states of CCl2F2 have been identified with average positions as follows: a(1)(C-Cl sigma*) at +0.4 eV and -0.9 eV, b(2)(C-Cl sigma*) at -2.5 eV, a(1)(C-F sigma*) at -3.5 eV, and b(1)(C-F sigma*) at -6.2 eV; an electron-excited Feshbach resonance is also indicated at -8.9 eV. (C) 1998 American Institute of Physics. [S0021-9606(98)02043-1]. C1 NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP NIST, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. EM Yicheng.Wang@nist.gov; loucas.christophorou@nist.gov NR 36 TC 19 Z9 19 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 15 PY 1998 VL 109 IS 19 BP 8304 EP 8310 DI 10.1063/1.477493 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139AJ UT WOS:000077005000019 ER PT J AU Cronin, MF McPhaden, MJ AF Cronin, MF McPhaden, MJ TI Upper ocean salinity balance in the western equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ATMOSPHERE RESPONSE EXPERIMENT; TIME-SERIES MEASUREMENTS; SEA-SURFACE TEMPERATURE; WARM POOL; MIXED-LAYER; TROPICAL PACIFIC; DECEMBER 1992; TOGA COARE; WIND BURST; VARIABILITY AB The upper ocean salinity balance in the western equatorial Pacific warm pool was evaluated using up to 2.5 years of data (September 1991 through April 1994) from the Coupled Ocean-Atmosphere Response Experiment's enhanced monitoring array of moorings. At the central mooring site (0 degrees, 156 degrees E), precipitation had a record-length mean of 4.5 m yr(-1), while evaporation had a mean of 1.4 m yr(-1). This excess surface freshwater flux was balanced primarily by vertical mixing (estimated as the residual of a salt budget calculation) and by zonal advection. For timescales between a month and 2.5 years, surface salinity variability was dominated by zonal advection and only weakly correlated with precipitation, consistent with the concept of a zonally migrating "fresh pool." The effects of precipitation on local surface salinity variations were more apparent for timescales shorter than a month. Shallow rain "puddles" tended to form in a matter of hours. However, owing to the combination of mixing and advection, these precipitation-generated freshwater puddles were typically short-lived. 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 52 TC 61 Z9 61 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD NOV 15 PY 1998 VL 103 IS C12 BP 27567 EP 27587 DI 10.1029/98JC02605 PG 21 WC Oceanography SC Oceanography GA 139AF UT WOS:000077004700001 ER PT J AU Swart, PK White, KS Enfield, D Dodge, RE Milne, P AF Swart, PK White, KS Enfield, D Dodge, RE Milne, P TI Stable oxygen isotopic composition of corals from the Gulf of Guinea as indicators of periods of extreme precipitation conditions in the sub-Sahara SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-SURFACE TEMPERATURE; TROPICAL ATLANTIC-OCEAN; CIRCULATION PATTERNS; FLUORESCENT BANDS; WEATHER ANOMALIES; NORTHEAST BRAZIL; SAHEL RAINFALL; ANNUAL CYCLE; VARIABILITY; SKELETONS AB Stable oxygen isotopic analyses of scleractinian coral skeletons from the Gulf of Guinea in the eastern Atlantic reveal that the corals from this region can be used to identify periods of severe drought and above average precipitation in sub-Sahara Africa. Data presented in this paper show an inverse correlation between precipitation in the Sahel and the delta(18)O values of a coral skeletons of the species Siderastrea spp. collected from the island of Principe in the Gulf of Guinea. This is opposite to the correlation expected, as previous work has suggested that higher sea surface temperatures occur in the Gulf of Guinea during periods of low rainfall in the Sahel. Such an association would lead to a positive correlation between Sahel precipitation and skeletal delta(18)O. The explanation for the observed inverse correlation is that the salinity of the Gulf of Guinea is strongly influenced by the outflow from the Niger and Congo rivers. These periods of high freshwater input also correlate with periods of higher rainfall in the sub-Sahara and therefore affect the delta(18)O values of the coral skeleton. The correlation between delta(18)O values of the coral skeleton and temperature in the northern subtropical Atlantic Ocean (r = 0.33), the magnitude of the dipole (r = 0.45), and the latitudinal position of the inter-tropical convergence zone (r = -0.37) illustrate that the delta(18)O values in the coral skeleton reflect climate dynamics of the region that affect the precipitation patterns in sub-Sahara Africa. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Nova SE Univ, Oceanog Ctr, Dania, FL USA. RP Swart, PK (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. RI Enfield, David/I-2112-2013; Swart, Peter/K-7041-2016 OI Enfield, David/0000-0001-8107-5079; NR 47 TC 14 Z9 14 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD NOV 15 PY 1998 VL 103 IS C12 BP 27885 EP 27891 DI 10.1029/98JC02404 PG 7 WC Oceanography SC Oceanography GA 139AF UT WOS:000077004700021 ER PT J AU Walton, CC Pichel, WG Sapper, JF May, DA AF Walton, CC Pichel, WG Sapper, JF May, DA TI The development and operational application of nonlinear algorithms for the measurement of sea surface temperatures with the NOAA polar-orbiting environmental satellites SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WATER-VAPOR; AEROSOLS; SPACE; AVHRR AB Since 1990, the NOAA National Environmental Satellite Data and Information Service (NESDIS) has provided satellite-derived sea surface temperature (SST) measurements based on nonlinear SST algorithms, using advanced very high resolution radiometer (AVHRR) multiple-infrared window channel data. This paper develops linear and nonlinear SST algorithms from the radiative transfer equation. It is shown that the nonlinear algorithms are more accurate than linear algorithms but that the functional dependence of the nonlinearity is data dependent. This theoretical discussion (sections 2-4) is followed with a discussion in section 5 of the accuracy over a 9-year period of the satellite-derived SST measurements provided by NOAA NESDIS when compared with coincident drifting buoys. Between 1989 and 1998 the global scatter of the daytime satellite SST against drifting buoy measurements has decreased from similar to 0.8 degrees to 0.5 degrees C, while the nighttime scatter has remained fairly constant at 0.5 degrees C. An exception to these accuracy measurements occurred after the eruption of Mount Pinatubo in June 1991. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. USN, Naval Oceanog Off, Stennis Space Ctr, MS 39529 USA. RP Walton, CC (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, NSC Room 102,Stop 9910,4700 Silver Hill Rd, Washington, DC 20233 USA. EM wpichel@nesdis.noaa.gov RI Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 45 TC 202 Z9 220 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD NOV 15 PY 1998 VL 103 IS C12 BP 27999 EP 28012 DI 10.1029/98JC02370 PG 14 WC Oceanography SC Oceanography GA 139AF UT WOS:000077004700029 ER PT J AU Zhou, CL Hobbie, EK Bauer, BJ Han, CC AF Zhou, CL Hobbie, EK Bauer, BJ Han, CC TI Equilibrium structure of hydrogen-bonded polymer blends SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE polymer blends; hydrogen bonding; small-angle neutron scattering ID CONTROLLABLE SPECIFIC INTERACTIONS; SPINODAL DECOMPOSITION; MISCIBILITY AB Deuterium-labeled polystyrene modified by random distributions of the comonomer p-(1,1,1,3,3,3-hexaflouro-2-hydroxyisopropyl)-alpha-methyl-styrene [DPS(OH)] has been blended with poly(butyl methacrylate) (PBMA) and studied with small-angle neutron scattering (SANS). Miscibility is induced via hydrogen bonding between the DPS(OH) hydroxyl group and PBNLA carbonyl groups. The data suggest that the nature of the miscible-phase structure in these blends differs from that of the usual homopolymer blends at small scattering angles, which we attribute to the short-range site specific nature of the hydrogen bond interaction. (C) 1998 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Hobbie, EK (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI He, Yong/F-8752-2012; Hobbie, Erik/C-8269-2013 NR 12 TC 7 Z9 8 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD NOV 15 PY 1998 VL 36 IS 15 BP 2745 EP 2750 DI 10.1002/(SICI)1099-0488(19981115)36:15<2745::AID-POLB8>3.0.CO;2-8 PG 6 WC Polymer Science SC Polymer Science GA 133AJ UT WOS:000076664000008 ER PT J AU Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Rosenbaum, TF Honig, JM Metcalf, P Trevino, SF AF Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Rosenbaum, TF Honig, JM Metcalf, P Trevino, SF TI Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V2O3 SO PHYSICAL REVIEW B LA English DT Review ID CR-DOPED V2O3; HUBBARD-MODEL; ITINERANT ANTIFERROMAGNETISM; ELECTRICAL-PROPERTIES; QUANTITATIVE ASPECTS; INFINITE DIMENSIONS; HIGH-PRESSURE; DENSITY-WAVE; NORMAL STATE; TRANSITION AB Magnetic correlations in all four phases of pure and doped vanadium sesquioxide (V2O3) have been examined by magnetic thermal-neutron scattering. Specifically, we have studied the antiferromagnetic and paramagnetic phases of metallic V2-yO3, the antiferromagnetic insulating and paramagnetic metallic phases of stoichiometric V2O3, and the antiferromagnetic and paramagnetic phases of insulating V1.944Cr0.056O3. While the antiferromagnetic insulator can be accounted for by a localized Heisenberg spin model, the long-range order in the antiferromagnetic metal is an incommensurate spin-density wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations with a "single lobe'' spectrum in the Stoner electron-hole continuum. Furthermore, our results in metallic V2O3 represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the self-consistent renormalization theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for (h) over bar omega90% of certified concentrations) of all PAHs measured, while results for the same SRM using HFC134a as the fluid were typically <80% of the certified concentrations for most of the PAHs measured. For SRM 1941a and 1944, both aquatic sediments with similar physical and chemical compositions, extractions of the wet materials with dichloromethane-modified CO2 (10%, v/v) yielded quantitative recoveries of all PAHs for SRM 1944 but an obvious trend of lower recoveries for higher molecular weight PAHs (greater than or equal to 228 amu) for SRM 1941a, Results of SFEs of SRM 1650 (Diesel Particulate Matter) showed that this material is the most refractory of the SRMs investigated in this study, with recoveries of indeno[1,2,3-cd]pyrene and benzo[ghi]perylene at <20% of the Soxhlet results. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Benner, BA (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 21 TC 48 Z9 49 U1 0 U2 6 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 1998 VL 70 IS 21 BP 4594 EP 4601 DI 10.1021/ac980618f PG 8 WC Chemistry, Analytical SC Chemistry GA 136BX UT WOS:000076839000029 PM 21644698 ER PT J AU Travis, JC Smith, MV Kramer, GW AF Travis, JC Smith, MV Kramer, GW TI Optical wedge effects in instruments and standards for molecular absorption spectrophotometry SO APPLIED SPECTROSCOPY LA English DT Article DE cell; cuvette; filter; optical quality; optical wedge; spectrophotometry; standard reference material; UV-visible absorption AB The optical wedge of some older, individual solid NIST absorbance filter standards has been found to cause bias in the indicated absorbance readings of certain instruments. In a collimated-beam spectrophotometer, the sample beam is deflected by about half of the wedge angle in the sample. For inverted geometry designs, small deflections can give rise to large changes in the field of view of the entrance slit of the spectrometer downstream from the sample. Beam deflection is also found to induce small apparent wavelength shifts in data taken through a wedged sample, resulting in spectral artifacts derived from spectral features of the system or of an absorbing sample. These spectral artifacts turn out to be robust, and simple cell-reversal difference spectra can provide useful diagnostic indicators of optical wedge. Solid photometric standards are found to be reliable, if manufactured to wedge angles of less than 0.1 mrad. Despite a wedge tolerance of 0.9 mrad in the sealed cuvettes of a wavelength standard, wavelength shifts are shown to be negligible when compared to the stated uncertainties. For normal use, accuracy may be achieved by utilizing the same cell in the same orientation for both background and sample spectra or by hand selection of cells. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Travis, JC (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD NOV PY 1998 VL 52 IS 11 BP 1414 EP 1424 DI 10.1366/0003702981943040 PG 11 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 141HY UT WOS:000077138600010 ER PT J AU Leka, KD Skumanich, A AF Leka, KD Skumanich, A TI The evolution of pores and the development of penumbrae SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : activity; Sun : magnetic fields; sunspots; techniques : polarimetric ID ADVANCED STOKES POLARIMETER; SOLAR MAGNETIC FEATURES; INFRARED LINES; EVERSHED FLOW; SIPHON-FLOW; SUNSPOTS; FIELDS; FLUX; PHOTOSPHERE; DEPENDENCE AB We investigate the evolution of the magnetic field in an emerging active region near disk center using data from the Advanced Stokes Polarimeter. Specifically, we follow the formation of a pore from a radiatively undisturbed region and the formation of a protospot, i.e., the appearance of a rudimentary penumbral sector for a mature pore. Our approach is to use the temporal evolution of bivariate distribution functions correlating continuum intensity, I-c, magnetic field magnitude, \B\, magnetic fill fraction, f, local inclination, gamma, local azimuth, phi, and line-of-sight Doppler velocity, upsilon(D). The highlights of our results include, (1) in the pore-forming region, a preference for the relatively strong vertical field points (1000-1500 G) to be redshifted (downflowing) and the appearance of dark pore points to be at the expense of radiatively undisturbed points; (2) an onset flux of approximate to 2 x 10(19) Mx in a dark pore that appears in an area in which the flux increases by approximate to 1 x 10(20) Mx prior to the pore's appearance and that previously contained an azimuth center, i.e., a magnetic concentration that otherwise has no continuum-intensity signature; (3) a threshold of (1-1.5) x 10(20) Mx above which a partial penumbra forms; (4) the appearance of penumbral elements that at once having the appropriate penumbral range of field strengths, intensities, and inclination angles, i.e., no obvious gradual, increase in the magnetic fields' inclination with increasing flux during the formation of penumbrae; (5) no delay between the appearance of inclined penumbral magnetic fields and the Evershed flow; and (6) a self-similarity between the pore, protospot, and a small mature sunspot with respect to the (\B\, I-c), (\B\, gamma), (f, gamma), and the (upsilon(D), I-c), (upsilon(D), gamma) distributions. C1 Natl Ctr Atmospher Res, Adv Study Program, Boulder, CO 80307 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP Leka, KD (reprint author), NOAA, SEC, Boulder, CO 80303 USA. NR 44 TC 66 Z9 66 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1998 VL 507 IS 1 BP 454 EP 469 DI 10.1086/306297 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152LQ UT WOS:000077779400044 ER PT J AU Tormosov, DD Mikhaliev, YA Best, PB Zemsky, VA Sekiguchi, K Brownell, RL AF Tormosov, DD Mikhaliev, YA Best, PB Zemsky, VA Sekiguchi, K Brownell, RL TI Soviet catches of southern right whales Eubalaena australis, 1951-1971. Biological data and conservation implications SO BIOLOGICAL CONSERVATION LA English DT Article DE southern right whales; distribution; movements; feeding; reproduction; conservation ID ATLANTIC RIGHT WHALES; MOVEMENTS; AFRICA; BALEEN AB Between 1951/1952 and 1970/1971, a total of at least 3368 southern right whales Eubalaena australis were taken by Soviet whaling expeditions in the Southern Hemisphere, despite the species being internationally protected since 1935. These catches and the associated biological data (presented here for the first time) represent a unique source of information on the distribution, movements, size composition, reproduction and feeding of southern right whales during summer months. Revelation of these previously unreported catches also has implications for the assessment of the current status of right whale stocks. Incorporation of the Soviet catches into population assessments generally leads to higher estimates of the size of the population at protection, but the relative increase in this size depends on the intrinsic rate of increase in the population. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Pretoria, Mammal Res Inst, ZA-0002 Pretoria, South Africa. ECAT, Kaliningrad 236040, Russia. S Ukrainian Pedag Univ, UA-270020 Odessa, Ukraine. Iktiologischeskuy Commisiy, Moscow 103050, Russia. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Best, PB (reprint author), Univ Pretoria, Mammal Res Inst, ZA-0002 Pretoria, South Africa. NR 33 TC 49 Z9 55 U1 0 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0006-3207 J9 BIOL CONSERV JI Biol. Conserv. PD NOV PY 1998 VL 86 IS 2 BP 185 EP 197 DI 10.1016/S0006-3207(98)00008-1 PG 13 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 126BN UT WOS:000076273000008 ER PT J AU Tu, KC Tarek, M Klein, ML Scharf, D AF Tu, KC Tarek, M Klein, ML Scharf, D TI Effects of anesthetics on the structure of a phospholipid bilayer: Molecular dynamics investigation of halothane in the hydrated liquid crystal phase of dipalmitoylphosphatidylcholine SO BIOPHYSICAL JOURNAL LA English DT Article ID GENERAL-ANESTHETICS; LIPID BILAYERS; VOLATILE ANESTHETICS; CONSTANT-PRESSURE; SOLUTE DIFFUSION; MEMBRANE; SIMULATION; WATER; RECEPTORS; SURFACE AB We report the results of constant temperature and pressure molecular dynamics calculations carried out on the liquid crystal (L-alpha) phase of dipalmitoylphosphatidylcholine with a mole fraction of 6.5% halothane (2-3 MAC). The present results are compared with previous simulations for pure dipalmitoylphosphatidylcholine under the same conditions (Tu et al., 1995, Biophys. J. 69:2558-2562) and with various experimental data. We have found subtle structural changes in the lipid bilayer in the presence of the anesthetic compared with the pure lipid bilayer: a small lateral expansion is accompanied by a modest contraction in the bilayer thickness. However, the overall increase in the system volume is found to be comparable to the molecular volume of the added anesthetic molecules. No significant change in the hydrocarbon chain conformations is apparent. The observed structural changes are in fair agreement with NMR data corresponding to low anesthetic concentrations. We have found that halothane exhibits no specific binding to the lipid headgroup or to the acyl chains. No evidence is obtained for preferential orientation of halothane dynamics of the lipid-bound halothane molecules appears to et al., 1995. C1 Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Med Ctr, Dept Anesthesia, Philadelphia, PA 19104 USA. RP Klein, ML (reprint author), Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. EM klein@lrsm.upenn.edu FU NIGMS NIH HHS [1 01 GM 55876] NR 71 TC 67 Z9 67 U1 0 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1998 VL 75 IS 5 BP 2123 EP 2134 PG 12 WC Biophysics SC Biophysics GA 132PF UT WOS:000076638200001 PM 9788906 ER PT J AU Tu, KC Klein, ML Tobias, DJ AF Tu, KC Klein, ML Tobias, DJ TI Constant-pressure molecular dynamics investigation of cholesterol effects in a dipalmitoylphosphatidylcholine bilayer SO BIOPHYSICAL JOURNAL LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; LIPID BILAYERS; NEUTRON-DIFFRACTION; X-RAY; MODEL MEMBRANES; HEAD GROUP; SIMULATIONS; TEMPERATURE; POTENTIALS; WATER AB We report a 1.4-ns constant-pressure molecular dynamics simulation of cholesterol at 12.5 mol% in a dipalmitoylphosphatidylcholine (DPPC) bilayer at 50 degrees C and compare the results to our previous simulation of a pure DPPC bilayer. The interlamellar spacing was increased by 2.5 Angstrom in the cholesterol-containing bilayer, consistent with x-ray diffraction results, whereas the bilayer thickness was increased by only 1 Angstrom. The bilayer/water interface was more abrupt because the lipid headgroups lie flatter to fill spaces left by the cholesterol molecules. This leads to less compensation by the lipid headgroups of the oriented water contribution to the membrane dipole potential and could explain the experimentally observed increase in the magnitude of the dipole potential by cholesterol, Our calculations suggested that 12.5 mol% cholesterol does not significantly affect the conformations and packing of the hydrocarbon chains and produces only a slight reduction in the empty free volume. However, cholesterol has a significant: influence on the subnanosecond time scale lipid dynamics: the diffusion constant for the center-of-mass "rattling" motion was reduced by a factor of 3, and the reorientational motion of the methylene groups was slowed along the entire length of the hydrocarbon chains. C1 Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Klein, ML (reprint author), Univ Penn, Dept Chem, Ctr Mol Modeling, Philadelphia, PA 19104 USA. EM klein@lrsm.upenn.edu RI Tobias, Douglas/B-6799-2015 FU NIGMS NIH HHS [R01 GM40712, F32 GM 14463] NR 37 TC 164 Z9 166 U1 1 U2 21 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1998 VL 75 IS 5 BP 2147 EP 2156 PG 10 WC Biophysics SC Biophysics GA 132PF UT WOS:000076638200003 PM 9788908 ER PT J AU Cione, JJ Neuherz, RA Raman, S Pietrafesa, LJ Keeter, K Li, XF AF Cione, JJ Neuherz, RA Raman, S Pietrafesa, LJ Keeter, K Li, XF TI The use of pre-storm boundary-layer baroclinicity in determining and operationally implementing the Atlantic surface cyclone intensification index SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE cyclogenesis; rapid deepening; Gulf Stream; baroclinicity; cold air advection ID JANUARY 1986; CLIMATOLOGY AB The lateral motion of the Gulf Stream off the eastern seaboard of the United States during the winter season can act to dramatically enhance the low-level baroclinicity within the coastal zone during periods of offshore cold advection. The ralative close proximity of the Gulf Stream current off the mid-Atlantic coast can result in the rapid and intense destabilization of the marine atmospheric boundary layer directly above and shoreward of the Gulf Stream within this region. This airmass modification period often precedes either wintertime coastal cyclogenesis or the cyclonic re-development of existing mid-latitude cyclones. A climatological study investigating the relationship between the severity of the pre-storm, cold advection period and subsequent cyclogenic intensification was undertaken by Clone et al. in 1993. Findings from this study illustrate that the thermal structure of the continental airmass as well as the position of the Gulf Stream front relative to land during the pre-storm period (i.e.. 24-48 h prior to the initial cyclonic intensification) are linked to the observed rate of surface cyclonic deepening for storms that either advected into or initially developed within the Carolina-southeast Virginia offshore coastal zone. it is a major objective of this research to test the potential operational utility of this pre-storm low level baroclinic linkage to subsequent cyclogenesis in an actual National Weather Service (NWS) coastal winter storm forecast setting. The ability to produce coastal surface cyclone intensity forecasts recently became available to North Carolina State University researchers and NWS forecasters. This statistical forecast guidance utilizes regression relationships derived from a nine-season (January 1982-April 1990), 116-storm study conducted previously. During the period between February 1994 and February 1996, the Atlantic Surface Cyclone Intensification Index (ASCII) was successfully implemented in an operational setting by the NWS at the Raleigh-Durham (RAH) forecast office for 10 winter storms. Analysis of these ASCII forecasts will be presented. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. NOAA, Natl Weather Serv, Raleigh Durham Forecast Off, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Suitland, MD 20233 USA. RP Cione, JJ (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RI CIONE, JOSEPH/B-2973-2014; Li, Xiaofeng/B-6524-2008 OI CIONE, JOSEPH/0000-0002-2011-887X; Li, Xiaofeng/0000-0001-7038-5119 NR 12 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD NOV PY 1998 VL 89 IS 2 BP 211 EP 224 DI 10.1023/A:1001773019199 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 155BG UT WOS:000077925600003 ER PT J AU Wirth, EF Fulton, MH Chandler, GT Key, PB Scott, GI AF Wirth, EF Fulton, MH Chandler, GT Key, PB Scott, GI TI Toxicity of sediment associated PAHs to the estuarine crustaceans, Palaemonetes pugio and Amphiascus tenuiremis SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID SOUTHEASTERN UNITED-STATES; 2 ESTUARIES; HYDROCARBONS C1 NOAA, USDC, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res Charleston, Charleston, SC 29412 USA. Univ S Carolina, Sch Publ Hlth, Dept Environm Hlth Sci, Columbia, SC 29208 USA. RP Wirth, EF (reprint author), NOAA, USDC, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res Charleston, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 12 TC 15 Z9 16 U1 1 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD NOV PY 1998 VL 61 IS 5 BP 637 EP 644 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 146PN UT WOS:000077439700011 PM 9841724 ER PT J AU Rozas, LP Minello, TJ AF Rozas, LP Minello, TJ TI Nekton use of salt marsh, seagrass, and nonvegetated habitats in a south Texas (USA) estuary SO BULLETIN OF MARINE SCIENCE LA English DT Article ID CRABS CALLINECTES-SAPIDUS; JUVENILE BLUE CRABS; PENAEUS-AZTECUS; DECAPOD CRUSTACEANS; FISH COMMUNITIES; BROWN SHRIMP; SPECIES COMPOSITION; SEASONAL ABUNDANCE; UNVEGETATED AREAS; NATANT MACROFAUNA AB We quantified nekton densities to estimate relative nursery values of Spartina alterniflora salt marsh, seagrass dominated by Ruppia maritima and Halodule wrightii, and shallow (<1 m deep) nonvegetated habitat in the Aransas National Wildlife Refuge in Texas. In each of two seasons of high nekton abundance, fall (September 1993) and spring (May 1994), we took 100 quantitative samples using a 1-m(2) drop sampler. We collected a total of 38 species of fishes and 19 species of decapod crustaceans. Vegetated habitats supported significantly higher densities of most numerically dominant species. Densities of total crustaceans, daggerblade grass shrimp Palaemonetes pugio, blue crabs Callinectes sapidus, and brackish grass shrimp Palaemonetes intermedius were significantly higher in salt marsh than seagrass. However, densities of total fishes, naked gobies Gobiosoma bosc, spotted seatrout Cynoscion nebulosus, pinfish Lagodon rhomboides, gulf pipefish Syngnathus scovelli, brown shrimp Farfantepenaeus aztecus (fall), white shrimp Litopenaeus setiferus, and pink shrimp Farfantepanaeus duorarum were not significantly different in salt marsh and seagrass. In spring, brown shrimp densities were higher in seagrass than salt marsh. In contrast to other abundant species, mean densities of bay anchovies Anchoa mitchilli were higher over nonvegetated bottom than in vegetated habitats in both seasons. Nekton size also differed among habitats, and organisms generally were smaller in seagrass beds than in marsh habitat. Our results provide further documentation that shallow vegetated habitats are important nurseries for many estuarine species. Furthermore, our study showed that where salt marsh and seagrass co-occur, most decapod crustaceans either selected for marsh habitat or showed no preference between these two vegetated habitats. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Galveston, TX 77551 USA. RP Rozas, LP (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 4700 Ave U, Galveston, TX 77551 USA. EM Lawrence.Rozas@noda.gov NR 76 TC 101 Z9 106 U1 4 U2 22 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD NOV PY 1998 VL 63 IS 3 BP 481 EP 501 PG 21 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 163LR UT WOS:000078407600003 ER PT J AU Morton, SL Villareal, TA AF Morton, SL Villareal, TA TI Bloom of Gonyaulax polygramma Stein (Dinophyceae) in a coral reef mangrove lagoon, Douglas Cay, Belize SO BULLETIN OF MARINE SCIENCE LA English DT Article C1 NOAA, NOS, Charleston, SC 29412 USA. Univ Texas, Inst Marine Sci, Port Aransas, TX 78373 USA. RP Morton, SL (reprint author), NOAA, NOS, 219 Ft Johnson Rd, Charleston, SC 29412 USA. RI Villareal, Tracy/I-9462-2012 NR 16 TC 2 Z9 3 U1 0 U2 0 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD NOV PY 1998 VL 63 IS 3 BP 639 EP 642 PG 4 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 163LR UT WOS:000078407600019 ER PT J AU Bove, MC Elsner, JB Landsea, CW Niu, XF O'Brien, JJ AF Bove, MC Elsner, JB Landsea, CW Niu, XF O'Brien, JJ TI Effect of El Nino on US landfalling hurricanes, revisited SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB Changes in the frequency of U.S. landfalling hurricanes with respect to the El Nino-Southern Oscillation (ENSO) cycle are assessed. Ninety-eight years (1900-97) of U.S. landfalling hurricanes are classified, using sea surface temperature anomaly data from the equatorial Pacific Ocean, as occurring during an El Nino (anomalously warm tropical Pacific waters), La Nina (anomalously cold tropical Pacific waters), or neither (neutral). The mean and variance of U.S. landfalling hurricanes are determined for each ENSO phase. Each grouping is then tested for Poisson distribution using a chi-squared test. Resampling using a "bootstrap" technique is then used to determine the 5% and 95% confidence limits of the results. Last, the frequency of major U.S. landfalling hurricanes (sustained winds of 96 kt or more) with respect to ENSO phase is assessed empirically. The results indicated that El Nino events show a reduction in the probability of a U.S. landfalling hurricane, while La Nina shows an increase in the chance of a U.S. hurricane strike. Quantitatively, the probability of two or more landfalling U.S. hurricanes during an El Nino is 28%, of two or more landfalls during neutral conditions is 48%, and of two or more landfalls during La Nina is 66%. The frequencies of landfalling major hurricanes show similar results. The probability of one or more major hurricane landfall during El Nino is 23% but is 58% during neutral conditions and 63% during La Nina. C1 Florida State Univ, Ctr Ocean Atmospher Predict Studies, Tallahassee, FL 32306 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. Florida State Univ, Dept Stat, Tallahassee, FL 32306 USA. RP O'Brien, JJ (reprint author), Florida State Univ, Ctr Ocean Atmospher Predict Studies, Tallahassee, FL 32306 USA. NR 9 TC 156 Z9 159 U1 1 U2 17 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1998 VL 79 IS 11 BP 2477 EP 2482 DI 10.1175/1520-0477(1998)079<2477:EOENOO>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 143BL UT WOS:000077235200002 ER PT J AU Hasler, AF Palaniappan, K Kambhammetu, C Black, P Uhlhorn, E Chesters, D AF Hasler, AF Palaniappan, K Kambhammetu, C Black, P Uhlhorn, E Chesters, D TI High-resolution wind fields within the inner core and eye of a mature tropical cyclone from GOES 1-min images SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SATELLITE AB Mesoscale wind fields have been determined for a mature hurricane with high spatial and temporal resolution, continuity, and coherency. These wind fields, near the tropopause in the inner core and at low levels inside the eye, allow the evolution of mesoscale storm features to be observed. Previously, satellite-derived winds near hurricanes have been determined only at some distance from the eye over a typical time period of 1-2 h. Hurricane reconnaissance aircraft take 30 min to 1 h to complete an inner-core pattern. With the long observation periods of these previous methods, steady-state conditions must be assumed to give a complete description of the observed region. With the advent of 1-min interval imagery, and fourfold improvement of image dynamic range from NOAA's current generation of GOES satellites, there is a new capability to measure inner-core tropical cyclone wind fields near the tropopause and within the eye, enabling mesoscale dynamical processes to be inferred. These measurements give insights into the general magnitude and structure of the hurricane vortex, along with very detailed measurements of the cloud-top wind's variations in response to convective outbursts. This paper describes the new techniques used to take advantage of the GOES satellite improvements that, in turn, allowed the above innovations to occur. The source of data for this study is a nearly continuous 12-h sequence of 1-min visible images from NOAA GOES-9 on 6 September 1995. These images are centered on Hurricane Luis with maximum winds of 120 kt (CAT4) when it was 250 km northeast of Puerto Rico. A uniform distribution of long-lived cirrus debris with detailed structure is observed in the central dense overcast (CDO), which has been tracked using the 1-min images. The derived wind field near the tropopause at approximately 15 km in the CDO region has a strong closed circulation with speeds up to 25 m s(-1), which pulses in response to the convective outbursts in the eyewall. Cloud displacements are computed at every pixel in every image, resulting in a quarter-million u-v winds in each of 488 hurricane images observed at 1- to 4-min intervals over 12 h. For analysis and presentation, these ultradense wind fields are reduced to 8- or 16-km grids using a 7-min time base by smoothing displacement vectors in space and time. Cloud structures were tracked automatically on a massively parallel processing computer, but with manual spot-checking. Manual tracking has been used to follow CDO structure over long time periods, up to 90 min for a small test sample. Cloud tracking for the wind fields presented here is accomplished using a Massively Parallel Semi-Fluid Motion Analysis (MPSMA) automatic technique. This robust deformable surface-matching algorithm has been implemented on the massively parallel Maspar supercomputer. MPSMA automatic tracking typically follows a feature for 7 min. For this time base the error of these winds is estimated to be 1.5 m s(-1). However, systematic navigation and height assignment errors in the moderately sheared hurricane environment must still be considered. Spatial and temporal smoothing of the wind field have been performed to reduce systematic navigation errors and small-scale turbulent noise. The synthesis used here to compute the wind fields gives an order of magnitude reduction in the amount of data presented compared to the amount of data processed. Longer tracking could give higher accuracy but would smooth out the smaller-scale spatial and temporal features that appear dynamically significant. The authors believe that the techniques described in this paper have great potential for further research on tropical cyclones and severe weather as well as in operational use for nowcasting and forecasting. United States and foreign policymakers are urged to augment the GOES, GMS, FY2, and Meteosat geostationary satellite systems with dual imaging systems such that I-min observations are routinely taken. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Delaware, Dept Comp & Informat Sci, Newark, DE 19716 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Hasler, AF (reprint author), NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. RI Palaniappan, Kannappan/A-3231-2008; Uhlhorn, Eric/B-1336-2014 OI Uhlhorn, Eric/0000-0002-4759-5342 NR 27 TC 31 Z9 31 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1998 VL 79 IS 11 BP 2483 EP 2496 DI 10.1175/1520-0477(1998)079<2483:HRWFWT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 143BL UT WOS:000077235200003 ER PT J AU Ellrod, GP Achutuni, RV Daniels, JM Prins, EM Nelson, JP AF Ellrod, GP Achutuni, RV Daniels, JM Prins, EM Nelson, JP TI An assessment of GOES-8 imager data quality SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GEOSTATIONARY SATELLITE; GOES-I; OPERATIONS; CLOUDS; WINDS; VAS; FOG AB The Geostationary Operational Environmental Satellite-8 (GOES-8), the first in the GOES I-M series of advanced meteorological satellites was launched in April 1994 and became operational at 75 degrees W longitude the following year. GOES-8 features numerous improvements over prior GOES platforms such as 1) improved resolution in the infrared (IR) and water vapor bands, 2) reduced instrument noise, 3) 10-bit visible and IR digitization, 4) greater image frequency, 5) more spectral bands, and 6) an independent sounder. A qualitative and quantitative comparison of the imager data from GOES-8 and GOES-7 shows that imagery from the newer spacecraft is superior in most respects. Improvements in resolution and instrument noise on GOES-8 provide sharper, cleaner images that allow easier detection of significant meteorological or oceanographic features. Infrared temperature comparisons between GOES-8 and GOES-7 were within 0.5 degrees-2.0 degrees C for all IR bands, indicating consistency between the two spacecraft. Visible band albedos from GOES-8 were at least 50% greater than GOES-7 for a wide range of scenes, suggesting that output from the GOES-7 visible detectors had degraded since its launch in 1987. Products derived from GOES-8 imager data for observing fog at night, fire detection, heavy precipitation estimation, and upper-level winds based on cloud or water vapor motion have been shown to be superior to similar products from GOES-7. Early difficulties with image registration and IR striping were alleviated after the first year. Based on the performance of GOES-g, future spacecraft in the GOES I-M series can be expected to provide many years of useful service to meteorologists, oceanographers, and the environmental monitoring community. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Madison, WI USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. RP Ellrod, GP (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, 4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. EM gellrod@nesdis.noaa.gov RI Daniels, Jaime/E-7933-2011 OI Daniels, Jaime/0000-0002-9438-6631 NR 47 TC 18 Z9 18 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1998 VL 79 IS 11 BP 2509 EP 2526 DI 10.1175/1520-0477(1998)079<2509:AAOGID>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 143BL UT WOS:000077235200005 ER PT J AU Karl, TR Knight, RW AF Karl, TR Knight, RW TI Comments on "Secular trends of precipitation amount, frequency, and intensify in the United States" - Reply SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Karl, TR (reprint author), Natl Climat Data Ctr, Asheville, NC 28801 USA. NR 6 TC 2 Z9 2 U1 2 U2 4 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 1998 VL 79 IS 11 BP 2552 EP 2554 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 143BL UT WOS:000077235200009 ER PT J AU Silverstein, JT Shearer, KD Dickhoff, WW Plisetskaya, EM AF Silverstein, JT Shearer, KD Dickhoff, WW Plisetskaya, EM TI Effects of growth and fatness on sexual development of chinook salmon (Oncorhynchus tshawytscha) parr SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COHO SALMON; AMAGO-SALMON; SALAR L; MATURATION; INSULIN; KISUTCH; FISHES; SIZE; RADIOIMMUNOASSAY; SMOLTIFICATION AB The independent effects of size and fatness, 1 year prior to maturity, on male sexual development of chinook salmon (Oncorhynchus tshawytscha) were tested. Beginning in March 1995, ration size and dietary lipid were independently manipulated to produce four groups of spring chinook salmon differing in size and fatness. Size, growth rate, adiposity, Liver triacylglycerol and glycogen contents, and plasma insulin and insulin-like growth factor I (IGF-I) levels were monitored to follow the metabolic states of fish in the different treatment groups and to observe whether plasma levels of these growth mediators predict sexual development. Differences in size and fatness were well established by the first autumn (September 1995), 1 year prior to sexual maturity, and common ration size groups were pooled for further rearing. Subsequently in winter-spring (February-March), 6 months prior to sexual maturity, there were no within-tank differences in size or fatness. Nevertheless, the effects of size and fatness, from I year earlier, on incidence of sexual maturity were significant. Overall, size appeared to have the primary effect, but for smaller fish, an effect of fat content was indicated. Plasma insulin levels, and in limited cases, IGF-I levels, were correlated with growth rate and size, but were not accurate indicators of sexual development. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Silverstein, JT (reprint author), Jamie Whitten Delta States Res Ctr, Expt Stn Rd,5 Story Bldg,POB 38, Stoneville, MS 38776 USA. NR 31 TC 105 Z9 107 U1 0 U2 6 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 1998 VL 55 IS 11 BP 2376 EP 2382 DI 10.1139/cjfas-55-11-2376 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 149LB UT WOS:000077605800002 ER PT J AU Nalepa, TF Hartson, DJ Fanslow, DL Lang, GA Lozano, SJ AF Nalepa, TF Hartson, DJ Fanslow, DL Lang, GA Lozano, SJ TI Declines in benthic macroinvertebrate populations in southern Lake Michigan, 1980-1993 SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID DREISSENA-POLYMORPHA COLONIZATION; GREAT-LAKES; SAGINAW BAY; COMMUNITIES; EUTROPHICATION; ABUNDANCE; INVASION; BIVALVIA; BIOMASS; ONTARIO AB Densities of the major benthic macroinvertebrate groups declined dramatically at sites shallower than 50 m in southern Lake Michigan between 1980 and 1993. Declines in Diporeia, Oligochaeta, and Sphaeriidae ranged from 40 to 75% at these depths. Total densities declined from 16 800.m(-2) in 1980-1981 to 4800.m(-2) in 1992-1993 at sites in the 16-30 m depth interval and from 21 300 to 11 300.m(-2) at sites in the 31-50 m depth interval. Changes at sites deeper than 50 m were minimal; only sphaeriids declined to any extent. Declines in oligochaetes and sphaeriids occurred uniformly throughout the nearshore region and over the entire sampling period. Declines in these two groups were most Likely related to reductions in phosphorus loads and a general decrease in productivity in the nearshore area over the sampling period. On the other hand, declines in Diporeia occurred mainly in the later portion of the sampling period and were greatest in the southeastern region of the lake. Densities at many sites in the southeastern region were <100.m(-2) in 1993, down from 3000-8000.m(-2) in 1980-1987. We hypothesize that the filtering activities of large populations of Dreissena polymorpha in nearshore waters may be having a negative impact on Diporeia in deeper waters by decreasing the amount of food available to this surface-feeding detritivore. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Cooperat Inst Res Environm Sci, Ann Arbor, MI 48109 USA. US EPA, Mid Continent Ecol Div, Duluth, MN 55804 USA. RP Nalepa, TF (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 45 TC 144 Z9 146 U1 2 U2 16 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 1998 VL 55 IS 11 BP 2402 EP 2413 DI 10.1139/cjfas-55-11-2402 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 149LB UT WOS:000077605800005 ER PT J AU Wada, T Jacobson, LD AF Wada, T Jacobson, LD TI Regimes and stock-recruitment relationships in Japanese sardine (Sardinops melanostictus), 1951-1995 SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SAGAX; BIOMASS; MACKEREL; ANCHOVY; TRENDS AB We used reproductive success, rather than abundance or catch, to identify regimes because reproductive success responds faster to environmental changes. Peak abundance of Japanese sardine during 1951-1995 was about 1000 times higher than minimum abundance. A regime shift occurred in the early 1970s when carrying capacity (measured using spawner-recruit models) increased by about 75 times. We hypothesize that this was due to large-scale changes in the Kuroshio and Oyashio Current systems. Long-term environmental variation (regimes), interannual variability in recruitment success, and density-dependent recruitment and growth rates affected dynamics of Japanese sardine. We hypothesize that density-dependent effects on recruitment of Sardinops spp. are common but usually obscured in short data sets by environmental variability and measurement error. Virtual population analysis and forward-simulation modeling approaches gave similar biomass and recruitment estimates. The relationship between sardine biomass and catch per unit search time was nonlinear. Mass-at-age and biomass were correlated, and it may be possible to use mass-at-age as an abundance index. Current abundance is low, and we believe that the environment has shifted to a regime that is unfavorable for Japanese sardine. C1 Japan Minist Agr Forestry & Fisheries, Natl Res Inst Fisheries Sci, Kanazawa Ku, Yokohama, Kanagawa 236, Japan. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Wada, T (reprint author), Japan Minist Agr Forestry & Fisheries, Natl Res Inst Fisheries Sci, Kanazawa Ku, 2-12-4 Fukuura, Yokohama, Kanagawa 236, Japan. NR 43 TC 51 Z9 57 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD NOV PY 1998 VL 55 IS 11 BP 2455 EP 2463 DI 10.1139/cjfas-55-11-2455 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 149LB UT WOS:000077605800010 ER PT J AU Misra, DN AF Misra, DN TI Interaction of some alkali metal citrates with hydroxyapatite - Ion-exchange adsorption and role of charge balance SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE adsorption; alkali metal citrates; hydroxyapatite; ion-exchange; surface charge ID DENTIN; DEMINERALIZATION; DRINKS; ENAMEL AB Proper balancing of the concentration of citrate ions in soft drinks is important in order to regulate the cariogenic potential of these ions. The uptake, or ion-exchange adsorption, of sodium or potassium citrates from their aqueous solutions onto synthetic hydroxyapatite at 22 degrees C was investigated in the present study as a means to elucidate the role of citrate ions in the cariogenic process. For each salt, the amount of uptake, or removal of citrate ions from its aqueous solutions by the apatite, bears a simple ratio to the amount of calcium or phosphate ions released into the solution by the substrate. The uptake isotherms may be represented by their Langmuir plots. The interaction is purely ion-exchange adsorption; there is no indication of the presence of any foreign phase. Plausible equations for ion-exchange equilibria show that the surface is electrically charged upon the adsorption of salts, but remains neutral upon the adsorption of the citric acid, and this may have a bearing on the effective area occupied by the absorbate species. (C) 1998 Published by Elsevier Science B.V. All rights reserved. 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 26 TC 18 Z9 20 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD NOV 1 PY 1998 VL 141 IS 2 BP 173 EP 179 DI 10.1016/S0927-7757(98)00332-X PG 7 WC Chemistry, Physical SC Chemistry GA 123PM UT WOS:000076133600003 ER PT J AU Dobbins, RA Fletcher, RA Chang, HC AF Dobbins, RA Fletcher, RA Chang, HC TI The evolution of soot precursor particles in a diffusion flame SO COMBUSTION AND FLAME LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; MASS-SPECTROMETRY; EMISSION FACTORS AB The chemical evolution of soot precursor particles on the centerline of the laminar ethene diffusion flame has been analyzed using laser microprobe mass spectrometry (LMMS) as they undergo the transition to carbonaceous aggregates. LMMS is a reliable microanalytical technique for the detection of intermediate and heavy polycyclic aromatic hydrocarbons (PAHs) in particulate material. The analyses show that many of the masses present within the precursor particles coincide with those predicted by Stein and Fahr (1985) to be most thermodynamically stable (stabilomers). The stabilomer PAHs that consist solely of six-membered rings, the benzenoid PAHs, prove to be the most important members of the stabilomer grid. Pericondensed PAHs as large 472 amu, which is attributed to the molecule C38H16 with 12 hexagonal rings, are found to be constituents of the precursor particles. The PAH mass distribution diverges to the larger sizes with increasing height in the flame, and includes many of the species identified by others as gas-phase PAH constituents in hydrocarbon flames. Carbonization on the centerline of the flame occurs abruptly between 35 and 40 mm above the burner where the particle metamorphosis (from single precursor liquid-like particles to fused aggregates) and the decrease in hydrogen mole fraction (from 0.35 to 0.15) simultaneously occur. The presence of stabilomer PAHs reported by others in the particulate combustion product of a variety of fuels-aliphatic and aromatic gases, diesel fuel, elude oil, kerogen, carbon black feed stuck, cigarette tobacco, and biomass-suggests that the stabilomer grid represents the common path for the growth of PAHs which contribute to the formation of carbonaceous soot in these diverse instances. This observation can account for the previously noted invariance of the soot product of combustion from diverse fuels and devices. (C) 1998 by The Combustion Institute. C1 Brown Univ, Div Engn, Providence, RI 02912 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Dobbins, RA (reprint author), Brown Univ, Div Engn, Providence, RI 02912 USA. NR 30 TC 173 Z9 181 U1 6 U2 40 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD NOV PY 1998 VL 115 IS 3 BP 285 EP 298 DI 10.1016/S0010-2180(98)00010-8 PG 14 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA ZW416 UT WOS:000074408800001 ER PT J AU Embley, RW Lupton, JE Massoth, G Urabe, T Tunnicliffe, V Butterfield, DA Shibata, T Okano, O Kinoshita, M Fujioka, K AF Embley, RW Lupton, JE Massoth, G Urabe, T Tunnicliffe, V Butterfield, DA Shibata, T Okano, O Kinoshita, M Fujioka, K TI Geological, chemical, and biological evidence for recent volcanism at 17.5 degrees S: East Pacific Rise SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE East Pacific Rise; plumes; vents; hydrothermal processes; lavas; volcanism ID DE-FUCA RIDGE; 1993 COAXIAL EVENT; SUBMERSIBLE OBSERVATIONS; HYDROTHERMAL PLUMES; MIDOCEAN RIDGE; LAVA-FLOW; 17-DEGREES-S; 19-DEGREES-S; ERUPTION; SEGMENT AB The superfast-spreading portion of the East Pacific Rise at 17.5 degrees S is a magmatically robust section of mid-ocean ridge. Plumes characterized by high volatile/metal ratios, which has been hypothesized to be indicative of recent magmatism, were found between 17 degrees 22'S and 17 degrees 35'S in November-December 1993. Dives with the French submersible Nautile in December 1993 observed young sheet flows and widespread venting centered on the segment's shoalest point at 17 degrees 26'S. Eight submersible dives made one year later with the Japanese submersible Shinkai 6500 in September-November 1994 found glassy unsedimented lavas, a range of diffuse and high-temperature vents, and several types of biologic communities on the ridge crest beneath the volatile-rich 1993 plumes. The diffuse vents range from small areas in the youngest lavas characterized by very low-temperature flow (<10 degrees C) and a relatively low macrofaunal diversity, to larger areas where the (apparent) older surface was covered with a dense and diverse biotope including anemones, tubeworms, mussels and serpulids. Several inactive vents marked by dead mussel/clam beds are present in the southernmost portion of the site in the older lavas. Submersible mapping indicates that the youngest lava (L0 unit) erupted for at least 4 km along the strike of the ridge at the southern site, and for 5-10 lan at the northern site. The flow is up to 400 min width at the southern site and may be as much as 1-2 km in width at the northern site. Comparison of the observed 1993 Fe/S, H2S/heat, and He-3/heat plume values with time series measurements at sites on the northern East Pacific Rise and the Juan de Fuca Ridge, where the onset of the magmatic event is known, implies that the last magmatic event at 17.5'S occurred within several years prior to 1993. Continued rapid cooling of the underlying heat source is implied from the significant diminishment in the light-scattering intensity and rise height of the overlying plumes recorded during 1994 submersible dives. The type and diversity of the vent biota found on the LO vents also suggests a young system. The spatial and temporal scales of the accretion event at the 17.5 degrees S EPR site are similar in scale to eruptions on the intermediate-rate spreading North Cleft segment (Juan de Fuca Ridge) but the 17.5 degrees S event has more subtle gradients in the effusion rate of the eruptions and thermal and chemical character of the hydrothermal system. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, PMEL, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Geol Survey Japan, Dept Mineral Resources, Tsukuba, Ibaraki 305, Japan. Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC, Canada. Okayama Univ, Grad Sch Nat Sci & Technol, Okayama 700, Japan. Tokai Univ, Sch Marine Sci & Technol, Shizuoka 424, Japan. Japan Marine & Technol Ctr, Deep Sea Res Dept, Kanagawa 237, Japan. RP Embley, RW (reprint author), NOAA, PMEL, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. EM embley@pmel.noaa.gov RI SHIBATA, Tsugio/B-1544-2011; Wright, Dawn/A-4518-2011; Tunnicliffe, Verena/D-1056-2014; Butterfield, David/H-3815-2016 OI Wright, Dawn/0000-0002-2997-7611; Butterfield, David/0000-0002-1595-9279 NR 48 TC 29 Z9 31 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD NOV PY 1998 VL 163 IS 1-4 BP 131 EP 147 DI 10.1016/S0012-821X(98)00181-2 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 142CB UT WOS:000077181400011 ER PT J AU Caswell, W Brault, S Read, AJ Smith, TD AF Caswell, W Brault, S Read, AJ Smith, TD TI Harbor porpoise and fisheries: An uncertainty analysis of incidental mortality SO ECOLOGICAL APPLICATIONS LA English DT Article DE conservation biology; harbor porpoise; incidental mortality; Marine Mammal Protection Act; matrix population models; Monte Carlo methods; Phocoena phocoena; population growth rate; uncertainty analysis ID LIFE-HISTORY; PHOCOENA-PHOCOENA; POPULATION; MODEL; RATES; DEMOGRAPHY; INCREASE; WHALES; FUNDY; TIME AB The harbor porpoise (Phocoena phocoena) in the western North Atlantic is subject to mortality due to entanglement in gillnets. Such incidental mortality threatens a population if it is too large relative to the potential population growth rate. Critical values for incidental mortality have been established by the International Whaling Commission and the U.S. Marine Mammal Protection Act. As in many situations in conservation biology, use of these critical values depends on demographic calculations that are based on uncertain data. It is important to report not only estimates of demographic parameters, but also the uncertainty in those estimates. Hen, we use a Monte Carlo approach to evaluate uncertainty in population size, incidental mortality, and population growth rate of harbor porpoise. To describe survival, we used model life tables derived from other mammals with similar life histories. By randomly sampling the space of model life tables and the distributions of estimated fertility and age at first reproduction, we produced a probability distribution that characterizes the uncertainty in the potential population growth rate. The median estimate for the potential annual rate of increase lambda is approximately 1.10. Combining this information with the uncertainty of incidental mortality and of population size, we estimate the probability that the rate of incidental mortality exceeds the critical values established by the various management agencies; this probability ranges from 0.46 to 0.94. We conclude that recent incidental mortality rates are a threat to harbor porpoise populations. The methods developed here are applicable to other situations in which demographic analyses must be based on uncertain data. C1 Woods Hole Oceanog Inst, Dept Biol, Woods Hole, MA 02543 USA. Univ Massachusetts, Dept Biol, Boston, MA 02125 USA. Duke Univ, Marine Lab, Beaufort, NC 28516 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Caswell, W (reprint author), Woods Hole Oceanog Inst, Dept Biol, MS 34, Woods Hole, MA 02543 USA. OI Caswell, Hal/0000-0003-4394-6894 NR 60 TC 75 Z9 77 U1 2 U2 19 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1998 VL 8 IS 4 BP 1226 EP 1238 DI 10.1890/1051-0761(1998)008[1226:HPAFAU]2.0.CO;2 PG 13 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 141EL UT WOS:000077129600026 ER PT J AU Jeremiason, JD Eisenreich, SJ Baker, JE Eadie, BJ AF Jeremiason, JD Eisenreich, SJ Baker, JE Eadie, BJ TI PCB decline in settling particles and benthic recycling of PCBs and PAHs in Lake Superior SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; SEDIMENT TRAP FLUXES; GREAT-LAKES; POLYCHLORINATED-BIPHENYLS; ATMOSPHERIC DEPOSITION; MEDITERRANEAN-SEA; ORGANIC-CARBON; POLYCHLOROBIPHENYL CONGENERS; PARTICULATE MATTER; MICHIGAN AB Sediment traps were deployed at five sites in Lake Superior at multiple depths during lake stratification in 1987 and 1991. Mass, organic carbon, PCB, and PAH fluxes were determined. PCB concentrations on settling solids declined from 1984 to 1991 with a first-order rate constant of 0.26 yr(-1) similar to reported water column concentration decreases (0.20 yr(-1)). Total PCB settling fluxes from the upper 35 m of water averaged 121 +/- 40 ng/m(2).d in 1987 and 48 +/- 23 ng/m(2).d in 1991. Settling fluxes are greater than reported wet and dry deposition fluxes (2.8 ng/m(2).d) and demonstrate the intense recycling of PCBs within the lake. A large fraction (>50%) of the total Lake Superior water PCB burden is transported each year by settling particles to within 35 m of the lake bottom, but only 2-5% of settling PCBs accumulate in bottom sediments. Thus, most of the PCBs are recycled in the benthic region, possibly representing a major entry point for PCBs into higher trophic levels through the benthic food web. Benthic recycling of PAH compounds with three and four rings occurred, but a larger fraction of these settling PAHs accumulated in bottom sediments (8-33%). No consistent temporal trends were observed in PAH concentrations on settling particles from 1984 to 1991. C1 Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08903 USA. Univ Maryland, Chesapeake Biol Lab, Solomons, MD 20688 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Eisenreich, SJ (reprint author), Rutgers State Univ, Dept Environm Sci, 14 Coll Farm Rd, New Brunswick, NJ 08903 USA. EM eisenreich@aesop.rutgers.edu RI Baker, Joel/A-9685-2011 OI Baker, Joel/0000-0002-9980-7781 NR 59 TC 38 Z9 39 U1 2 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 1998 VL 32 IS 21 BP 3249 EP 3256 DI 10.1021/es980143+ PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 136GJ UT WOS:000076850200020 ER PT J AU Flores-Coto, C Sanchez-Iturbe, A Zavala-Garcia, F Warlen, SM AF Flores-Coto, C Sanchez-Iturbe, A Zavala-Garcia, F Warlen, SM TI Age, growth, mortality and food habits of larval Stellifer lanceolatus, Cynoscion arenarius and Cynoscion nothus (Pisces : Sciaenidae), from the Southern Gulf of Mexico SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE growth; mortality; larval Sciaenidae; Gulf of Mexico ID SPOT LEIOSTOMUS-XANTHURUS; NORTH-CAROLINA; VALIDATION; SEATROUT; OTOLITHS; EGGS; TIME AB Age, growth, mortality rates and food habits of the larvae of three sciaenid species were studied from the Southern Gulf of Mexico. The material was collected with a Bongo net (505 mu m mesh), during summer 1992. The Laird-Gompertz growth model was selected over other models because it offered the best approach to the determination of hatching size and gave the highest correlation coefficients. The instantaneous mortality rate for all three species was estimated from the exponential model of decreasing abundance of each (1.0 mm) age class. The entire digestive tract was removed from larval specimens in order to identify and quantify its content. The larval size range analysed, and the estimated hatching sizes from the model were 1.52-7.88 mm and 1.21 mm, 1.51-8.82 mm and 0.82 mm and 1.33-6.49 mm and 0.91 mm for Stellifer lanceolaters, Cynoscion arenarius and Cynoscion nothus, respectively. The growth rate decreased from 10.3% on day 1 to 4.6% on day 27 for S, lanceolatus, 20.1% on day 1 to 3.0% on day 28 for C. arenarius and from 14.5% on day 1 to 72 on day 20 for C. nothus. The instantaneous mortality rates were 0.20, 0.17 and 0.25 for S. lanceolatus, C. arenarius and C. nothus, respectively. The small hatching sizes recorded in the study may be due to the relatively high summer water temperatures (>30 degrees C) in the Southern Gulf of Mexico. Hatching sizes are similar to some non-sciaenid species from the Southern Gulf of Mexico. High mortality rate (0.20) of S. lanceolatus is related to the highest larval density (2.176 larvae 100 m(-3)) and the lowest average growth rate (7.0%). Copepods were the main larval food item for ail three species; there were also relatively high percentages of pelecypods in small S. lanceolatus larvae. Very few specimens simultaneously had two different kinds of prey, which could be a consequence of the patchy distribution of prey. The low proportion of empty digestive tracts suggests that there was a good food supply during that summer. (C) 1998 Academic Press. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Mexico City 04510, DF, Mexico. NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort Lab, Beaufort, NC 28516 USA. RP Flores-Coto, C (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Apdo Post 70-305, Mexico City 04510, DF, Mexico. NR 41 TC 6 Z9 7 U1 2 U2 10 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD NOV PY 1998 VL 47 IS 5 BP 593 EP 602 DI 10.1006/ecss.1998.0395 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 139FX UT WOS:000077018300005 ER PT J AU Narahari, Y Khan, LM AF Narahari, Y Khan, LM TI Asymptotic loss of priority scheduling policies in closed re-entrant lines: A computational study SO EUROPEAN JOURNAL OF OPERATIONAL RESEARCH LA English DT Article DE re-entrant lines; asymptotic loss; buffer priority policies; mean value analysis ID REENTRANT MANUFACTURING SYSTEMS; HEAVY TRAFFIC ANALYSIS; QUEUING-NETWORKS; CYCLE-TIME; QUEUES AB In this paper we present an approximate but efficient analytical method to compute the asymptotic loss of buffer priority scheduling policies in dosed re-entrant lines. For simple two-station closed re-entrant lines, this enables the verification of Harrison-Wein conjectures and Jin-Ou-Kumar results. For multi-station re-entrant lines, this provides an efficient way of comparing different buffer priority scheduling policies. We also use the method to evaluate the effect of high priority jobs in re-entrant lines. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Indian Inst Sci, Dept Comp Sci & Automat, Bangalore 560012, Karnataka, India. RP Narahari, Y (reprint author), Natl Inst Stand & Technol, Bldg 304-12, Gaithersburg, MD 20899 USA. NR 20 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-2217 J9 EUR J OPER RES JI Eur. J. Oper. Res. PD NOV 1 PY 1998 VL 110 IS 3 BP 585 EP 596 DI 10.1016/S0377-2217(97)00302-0 PG 12 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA 114XP UT WOS:000075634700011 ER PT J AU Fahey, SO Pratt, J AF Fahey, SO Pratt, J TI Time domain modal estimation techniques SO EXPERIMENTAL TECHNIQUES LA English DT Article ID PARAMETER-IDENTIFICATION C1 Elect Boat Corp, Groton, CT 06340 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Fahey, SO (reprint author), Elect Boat Corp, Groton, CT 06340 USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 USA SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD NOV-DEC PY 1998 VL 22 IS 6 BP 45 EP 49 DI 10.1111/j.1747-1567.1998.tb02302.x PG 5 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 144UF UT WOS:000077333000010 ER PT J AU Austin, PJ Buch, RR Kashiwagi, T AF Austin, PJ Buch, RR Kashiwagi, T TI Gasification of silicone fluids under external thermal radiation part I. Gasification rate and global heat of gasification SO FIRE AND MATERIALS LA English DT Article AB Transient gasification rates and fluid temperatures were measured for polydimethylsiloxane fluids ranging in viscosity from 0.65 cS to 60000 cS in a nitrogen atmosphere at external radiant fluxes from 20 kW/m(2) to 70 kW/m(2). A detailed energy balance for each fluid sample was conducted to determine its global heat of vaporization. Two major energy loss corrections were identified and quantified. The absorption of incident radiation by the volatile products from short chain oligomers was measured and found to substantially reduce the incident flux to the sample surface; the energy loss due to re-radiation was determined to be a substantial factor in reducing the net heat flux to the sample for long chain length fluids. Other energy losses, e,g, heat loss to the substrate, were observed but were less significant. The average gasification rate for each fluid increased linearly with increasing external radiant flux. The global heat of gasification increases with an increase in the chain length (molecular weight) for the siloxane oligomers. These agreed well with calculated values. The global heat of gasification for 50 cS fluid is about 1200 kJ/kg and its value remains nearly constant for all higher molecular weight dimethylsiloxanes, Pyrolysis rates for siloxane fluids are very sensitive to trace catalysts, Measurements of the global heat of gasification for ultra-clean polymers resulted in significantly higher values (3000 kJ/kg), The gasification of siloxanes occurs via two modes or combinations thereof: (1) volatilization of molecular species native to the polymer, and (2) volatilization of thermal degradation products. The former process dominates for low molecular weight siloxanes (eta < 10 cS) and the latter process dominates for high molecular weight siloxanes (eta > 1000 cS). For the intermediate molecular weight siloxanes, both volatilization and degradation processes occur. (C) 1998 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Buch, RR (reprint author), Dow Corning Corp, 2200 W Salzburg Rd, Auburn, MI 48611 USA. NR 18 TC 38 Z9 38 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD NOV-DEC PY 1998 VL 22 IS 6 BP 221 EP 237 DI 10.1002/(SICI)1099-1018(199811/12)22:6<221::AID-FAM658>3.0.CO;2-D PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA 177JP UT WOS:000079207100001 ER PT J AU Buch, RR Austin, PJ Kashiwagi, T AF Buch, RR Austin, PJ Kashiwagi, T TI Gasification of silicone fluids under external thermal radiation. Part 2. Gasification products - Characterization and quantitation SO FIRE AND MATERIALS LA English DT Article AB The gasification behavior for a wide range of polydimethylsiloxane fluids in a nitrogen atmosphere was investigated. Part 1 of this study addressed the measurement of the energy (global heat of gasification) required for the gasification of a wide range of dimenthylsiloxanes. Several significant corrections were required to reconcile measured gasification energy(s) with calculated heat(s) of gasification based on fundamental thermochemical data. The identification of the dominant mode(s) of gasification via the characterization of pyrolysis products provided a firm basis and rationale for understanding and directing efforts at quantifying these correction factors, In Part 2, the gasification products were identified and quantified at various stages of the gasification process corresponding to ignition, fire growth, and steady-state burning. Pyrolysis of methylated siloxanes occurs via two modes: (1) the volatilization of short chain and intermediate chain length species native to the polymer, and (2) the volatilization of short chain and intermediate chain length species resulting from thermal degradation via siloxane rearrangement. The former process is the dominant gasification mechanism for short chain oligomers and low viscosity fluids (eta< 10 cS) and the latter process is dominant in all higher molecular weight polymers (eta > 100 cS), Both gasification mechanisms are evident in all polymers (eta>20cS); the dominant mechanism is dependent upon polymer size and distribution thereof, the gasification stage, and the presence of trace catalysts in the polymer, Because of their structural similarity, the combustion of all gasification products emanating from PDMS regardless of the stage of the pyrolysis process or the dominant mode of gasification will result in virtually identical combustion products, i,e, SiO2, CO2, and H2O. Copyright (C) 1998 John Wiley & Sons, Ltd. This paper was written under the auspices of the US Government and is therefore not subject to copyright in the US. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Buch, RR (reprint author), 1812 Brookfield Dr, Midland, MI 48642 USA. NR 14 TC 1 Z9 1 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD NOV-DEC PY 1998 VL 22 IS 6 BP 239 EP 252 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 177JP UT WOS:000079207100002 ER PT J AU Ohlemiller, T Cleary, T Shields, J AF Ohlemiller, T Cleary, T Shields, J TI Effect of ignition conditions on upward flame spread on a composite material in a corner configuration SO FIRE SAFETY JOURNAL LA English DT Article AB This paper focuses on the issue of fire growth on composite materials beyond the region immediately subjected to an ignition source. Suppression of this growth is one of the key issues in realizing the safe usage of composite structural materials. A vinyl ester/glass composite was tested in the form of a 90 degrees corner configuration with an inert ceiling segment 2.44 m above the top of the fire source. The igniter was a square propane burner at the base of the corner, either 23 or 38 cm in width, with power output varied from 30 to 150 kW. Upward flame spread rate and heat release rate were measured mainly for a brominated vinyl ester resin but limited results were also obtained for a non-flame retarded vinyl ester and a similar composite coated with an intumescent paint. Rapid fire growth to the top of the sample was seen in replicate tests for the largest igniter power case; the intumescent coating successfully prevented fire growth for this case. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Ohlemiller, T (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 11 TC 7 Z9 7 U1 0 U2 5 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 1998 VL 31 IS 4 BP 331 EP 344 DI 10.1016/S0379-7112(98)00019-8 PG 14 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 135UM UT WOS:000076821000004 ER PT J AU Babrauskas, V Gann, RG Levin, BC Paabo, M Harris, RH Peacock, RD AF Babrauskas, V Gann, RG Levin, BC Paabo, M Harris, RH Peacock, RD TI A methodology for obtaining and using toxic potency data for fire hazard analysis SO FIRE SAFETY JOURNAL LA English DT Article DE building fires; combustion products; computer fire models; fire deaths; fire hazard analysis; N-gas model; radiant heating; smoke toxicity; toxicity test methods ID CARBON-MONOXIDE; SMOKE AB A comprehensive methodology has been developed for obtaining and using smoke toxicity data for fire hazard analysis. This description of the methodology comprises (1) determination that the post-flashover fire is the proper focus of smoke inhalation deaths; criteria for a useful bench-scale toxic potency (LC50) measurement method; (2) a method which meets these criteria, especially validation against real-scale fires; (3) a computational procedure for correcting the results from the bench-scale test for the CO levels observed in real-scale post-flashover fires; (4) procedures for reducing the usage of animals and broadening the applicability of data by interpreting gas measurement data using the N-Gas Model; and (5) a procedure for identifying whether a product produces smoke within the ordinary range of toxic potency for post-flashover fires. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Babrauskas, V (reprint author), Fire Sci & Technol Inc, 9000 300th Pl SE, Issaquah, WA 98027 USA. NR 32 TC 29 Z9 37 U1 0 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 1998 VL 31 IS 4 BP 345 EP 358 DI 10.1016/S0379-7112(98)00013-7 PG 14 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 135UM UT WOS:000076821000005 ER PT J AU Gann, RG AF Gann, RG TI Next-generation fire suppression technology program SO FIRE TECHNOLOGY LA English DT Article AB The Next-Generation Fire Suppression Program (NGP), now in its second year, has as its goal the development by 2004 of alternative firefighting technologies to Halon 1301 that can be economically implemented in aircraft, ships, land combat vehicles, and critical mission support facilities. This paper describes the first projects and their early results. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Gann, RG (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 0 TC 2 Z9 3 U1 1 U2 6 PU NATIONAL FIRE PROTECTION ASSOC PI QUINCY PA ONE BATTERYMARCH PK, QUINCY, MA 02269 USA SN 0015-2684 J9 FIRE TECHNOL JI Fire Technol. PD NOV PY 1998 VL 34 IS 4 BP 363 EP 371 DI 10.1023/A:1015370628661 PG 9 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 381CK UT WOS:000165744600007 ER PT J AU Slusher, JT AF Slusher, JT TI Estimation of infinite dilution activity coefficients in aqueous mixtures via molecular simulation SO FLUID PHASE EQUILIBRIA LA English DT Article DE molecular simulation; activity coefficient; excess Gibbs energy; aqueous alcohol; infinite dilution; chemical potential ID GIBBS FREE-ENERGY; LIMITING ACTIVITY-COEFFICIENTS; DYNAMICS COMPUTER-SIMULATION; CHARGING-INTEGRAL APPROACH; EXCESS FREE-ENERGY; THERMODYNAMIC PROPERTIES; MONTE-CARLO; DIATOMIC-MOLECULES; COEXISTENCE CURVE; SURFACE-TENSION AB Molecular dynamics simulations are employed to calculate infinite dilution activity coefficients of water and methanol-like species in binary mixtures using a variant of the Kirkwood coupling parameter method. Differences in residual Gibbs free energies are obtained as integrals over ensemble averages of the derivatives of total potential energy with respect to simple functions of the intramolecular potential energy parameters. The calculated limiting activity coefficients are compared with the experimental values at the same temperature obtained by direct measurement of the water/methanol binary and via extrapolation from vapor-liquid equilibria data. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Slusher, JT (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. EM joseph.slusher@nist.gov NR 52 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD NOV PY 1998 VL 153 IS 1 BP 45 EP 61 DI 10.1016/S0378-3812(98)00399-9 PG 17 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 143BP UT WOS:000077235500004 ER PT J AU Atkinson, S Ragen, TJ Gilmartin, WG Becker, BL Johanos, TC AF Atkinson, S Ragen, TJ Gilmartin, WG Becker, BL Johanos, TC TI Use of a GnRH agonist to suppress testosterone in wild male Hawaiian monk seals (Monachus schauinslandi) SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article DE GnRH agonist; testosterone; Hawaiian monk seals; Monachus schauinslandi ID HORMONE-RELEASING HORMONE; MICROCAPSULES; INHIBITION AB A gonadotropin-releasing hormone (GnRH) agonist, D-Trp(6)-LHRH, was evaluated for its effectiveness in reducing circulating testosterone concentrations in wild Hawaiian monk seals (Monachus schauinslandi). Twenty-eight adult male seals were randomly divided into three groups: 10 were captured and treated with 7.5 mg of the GnRH agonist, 9 were captured but did not receive the agonist, and 9 were captured near the end of the study to serve as handling controls. Blood samples were taken from all 28 seals. From 14 to 58 days after initial capture, 8 of the treated seals and 8 of the untreated seals were recaptured and a second sample of blood was taken. For comparison, blood was also collected from 4 captive adult male seals during the same months as the field study In the treated group, the agonist induced a significant decline in mean circulating testosterone concentrations, from 1.01 ng/ml (first sample) to 0.21 ng/ml (second sample, taken approximately 38 days later). In the untreated group, mean testosterone concentrations of the first and second samples were statistically indistinguishable (1.11 vs 1.16 ng/ml). The mean concentration of the untreated group (second sample) was also indistinguishable from the mean concentration of seals in the control group (1.16 vs 0.82 ng/ml). Also, mean testosterone concentration in the initial samples from the four captive seals was not statistically different from that of untreated wild seals (1.38 vs 1.11 ng/ml). These results suggest that (1) the GnRH agonist suppresses the production of testosterone in wild adult male Hawaiian monk seals, (2) a single handling of adult malt seals does not affect their testosterone levels, and (3) testosterone concentrations in captive male seals appear to be consistent with concentrations in wild seals. Further evaluation of this GnRH agonist is necessary before it is used in the management of this endangered species, but these results suggest it may be a useful tool for reducing mortality of monk seals from adult male aggression related to reproduction and mating behavior. (C) 1998 Academic Press. C1 Univ Hawaii, Hawaii Inst Marine Biol, Kaneohe, HI 96744 USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Atkinson, S (reprint author), Univ Hawaii, Hawaii Inst Marine Biol, POB 1346, Kaneohe, HI 96744 USA. NR 17 TC 8 Z9 9 U1 1 U2 9 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD NOV PY 1998 VL 112 IS 2 BP 178 EP 182 DI 10.1006/gcen.1998.7173 PG 5 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 135NW UT WOS:000076809900005 PM 9784300 ER PT J AU Danilin, MY Fahey, DW Schumann, U Prather, MJ Penner, JE Ko, MKW Weisenstein, DK Jackman, CH Pitari, G Kohler, I Sausen, R Weaver, CJ Douglass, AR Connell, PS Kinnison, DE Dentener, FJ Fleming, EL Berntsen, TK Isaksen, ISA Haywood, JM Karcher, B AF Danilin, MY Fahey, DW Schumann, U Prather, MJ Penner, JE Ko, MKW Weisenstein, DK Jackman, CH Pitari, G Kohler, I Sausen, R Weaver, CJ Douglass, AR Connell, PS Kinnison, DE Dentener, FJ Fleming, EL Berntsen, TK Isaksen, ISA Haywood, JM Karcher, B TI Aviation fuel tracer simulation: Model intercomparison and implications SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIRCRAFT SULFUR EMISSIONS; SUPERSONIC AIRCRAFT; LOWER STRATOSPHERE; TRANSPORT MODEL; AEROSOL; OZONE; SULFATE; IMPACT AB An upper limit for aircraft-produced perturbations to aerosols and gaseous exhaust products in the upper troposphere and lower stratosphere (UT/LS) is derived using the 1992 aviation fuel tracer simulation performed by eleven global atmospheric models. Key findings are that subsonic aircraft emissions: 1) have not be responsible for the observed water vapor trends at 40 degrees N; 2) could be a significant source of soot mass near 12 km, but not at 20 km, 3) might cause a noticeable increase in the background sulfate aerosol surface area and number densities (but not mass density) near the northern mid-latitude tropopause, and 4) could provide a global, annual mean top of the atmosphere radiative forcing up to +0.006 W/m(2) and -0.013 W/m(2) due to emitted soot and sulfur, respectively. C1 AER Inc, Cambridge, MA 02139 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. DLR, Inst Atmospher Phys, Oberpfaffenhofen, Germany. Univ Calif Irvine, Irvine, CA 92717 USA. Univ Michigan, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Univ Aquila, I-67100 Laquila, Italy. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Utrecht, Utrecht, Netherlands. Space Applicat Corp, Vienna, VA USA. Ctr Int Climate & Environm Res, Oslo, Norway. Univ Oslo, Oslo, Norway. Meteorol Off, Bracknell, Berks, England. RP Danilin, MY (reprint author), AER Inc, 840 Mem Dr, Cambridge, MA 02139 USA. RI Douglass, Anne/D-4655-2012; Penner, Joyce/J-1719-2012; Jackman, Charles/D-4699-2012; Karcher, Bernd/D-5325-2014; Ko, Malcolm/D-5898-2015; Fahey, David/G-4499-2013; Pitari, Giovanni/O-7458-2016 OI Schumann, Ulrich/0000-0001-5255-6869; Karcher, Bernd/0000-0003-0278-4980; Fahey, David/0000-0003-1720-0634; Pitari, Giovanni/0000-0001-7051-9578 NR 30 TC 44 Z9 45 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 1998 VL 25 IS 21 BP 3947 EP 3950 DI 10.1029/1998GL900058 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 136CE UT WOS:000076839800008 ER PT J AU Harrison, DE Larkin, NK AF Harrison, DE Larkin, NK TI Seasonal US temperature and precipitation anomalies associated with El Nino: Historical results and comparison with 1997-98 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN OSCILLATION AB Extreme weather occurred in many parts of the United States during the 1997-98 El Nino. We compare the 1997-98 autumn, winter, and spring temperature and precipitation anomalies with the historical El Nino period anomalies. About 90% of the contiguous U.S, has one or more statistically significant historical weather associations with El Nino. The 1997-98 wet anomalies and the autumn and winter temperature anomalies resemble their historical counterparts. Taken together, about 80% of the U.S, experienced extreme seasonal anomalies during 1997-98; 20% of the U.S. experienced 50-year-record winter temperature anomalies. However, these percentages are not remarkable. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. EM harrison@pmel.noaa.gov; larkin@pmel.noaa.gov RI Harrison, Don/D-9582-2013 NR 8 TC 27 Z9 28 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1998 VL 25 IS 21 BP 3959 EP 3962 DI 10.1029/1998GL900061 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 136CE UT WOS:000076839800011 ER PT J AU Kudeki, E Fawcett, CD Ecklund, WL Johnston, PE Franke, SJ AF Kudeki, E Fawcett, CD Ecklund, WL Johnston, PE Franke, SJ TI Equatorial 150-km irregularities observed at Pohnpei SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DAYTIME AB First observations of meter-scale equatorial 150-km plasma irregularities outside the American longitude sector are reported. The observations conducted at Pohnpei (western Pacific) with a wind profiling ST radar demonstrate the feasibility of making ionospheric electric field measurements with low cost instruments and also reveal a potentially important anisotropy in the angular distribution of 150-km VHF radar echoes. C1 Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Kudeki, E (reprint author), Univ Illinois, Dept Elect & Comp Engn, 1406 W Green St, Urbana, IL 61801 USA. RI Johnston, Paul/E-1914-2016 OI Johnston, Paul/0000-0002-4046-9351 NR 9 TC 20 Z9 21 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 1998 VL 25 IS 21 BP 4079 EP 4082 DI 10.1029/1998GL900069 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 136CE UT WOS:000076839800041 ER PT J AU Moayeri, N AF Moayeri, N TI A low-complexity, fixed-rate compression scheme for color images and documents SO HEWLETT-PACKARD JOURNAL LA English DT Article AB Based on one-dimensional differential pulse code modulation. the coder is multiplication-free, codes each pixel as soon as it: is available, and outputs a fixed number of bits for each pixel. Hence, there is no need for any buffering of the input image or coder output bitstream. The compression scheme is visually lossless and yields a modest compression ratio of 3 to 4. Because of its simplicity, it is useful when hardware is limited and coding delays cannot be tolerated. C1 Hewlett Packard Co, HP Labs, Imaging Technol Dept, Palo Alto, CA 94304 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. RP Moayeri, N (reprint author), US Natl Inst Stand & Technol, Wireless Commun Technol Grp, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU HEWLETT-PACKARD CO PI PALO ALTO PA C/O SUSAN WRIGHT MS 27UT HEWLETT-PACKARD PUBLISHING, 3495 DEER CREEK RD, PALO ALTO, CA 94304 USA SN 0018-1153 J9 HEWLETT-PACKARD J JI Hewlett-Packard J. PD NOV PY 1998 VL 50 IS 1 BP 46 EP 52 PG 7 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA 231EG UT WOS:000082294700007 ER PT J AU Chang, PS Li, L AF Chang, PS Li, L TI Ocean surface wind speed and direction retrievals from the SSM/I SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE microwave radiometry; neural network applications; ocean surface winds; Special Sensor Microwave/Imager (SSM/I); wind retrieval algorithms ID MICROWAVE BRIGHTNESS TEMPERATURES; SEA-SURFACE; MODEL; ALGORITHM; SCATTERING; RADIOMETER; IMAGER AB A semiempirical model is developed that retrieves ocean surface wind direction information in addition to improved wind speeds from Special Sensor Microwave/Imager (SSM/I) measurements, Radiative transfer and neural network techniques mere combined in our approach. The model was trained and tested using clear sky cases, but atmospheric transmittance is retrieved so that retrieval in other than clear sky conditions is possible. With two SSM/I instruments currently providing operational ocean surface wind speed retrievals, the addition of wind direction information and improved wind speed retrievals will enhance the impact of this data in weather prediction models and marine weather forecasting. C1 Caelum Res Corp, Silver Spring, MD 20901 USA. NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. RP Chang, PS (reprint author), NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. EM pchang@nesdis.nona.gov RI Chang, Paul/F-5580-2010 OI Chang, Paul/0000-0001-5113-0938 NR 26 TC 13 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD NOV PY 1998 VL 36 IS 6 BP 1866 EP 1871 DI 10.1109/36.729357 PG 6 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 139UT UT WOS:000077048600003 ER PT J AU Sarma, AD Hill, RJ AF Sarma, AD Hill, RJ TI Design aspects of a millimeter wave scintillometer for flux measurements SO IETE TECHNICAL REVIEW LA English DT Article ID FLUCTUATIONS AB The design aspects of a millimeter wave scintillometer system are described in detail. The dual amplitude channel receiver technique helps to eliminate errors common to both channels, mainly the atmospheric absorption effect. Several features to make the system mechanically stable and weather proof, such as double insulation to the receiver and transmitter components, are included. Experimental results showed that this system is reliable. This system, together with two other scintillometers at different wavelengths, can be used for measuring heat, humidity, and momentum fluxes. C1 Osmania Univ, R&T Unit Navigat Elect, Hyderabad 500007, Andhra Pradesh, India. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Sarma, AD (reprint author), Osmania Univ, R&T Unit Navigat Elect, Hyderabad 500007, Andhra Pradesh, India. NR 15 TC 0 Z9 0 U1 1 U2 2 PU INST ELECTRONICS TELECOMMUNICATION ENGINEERS PI NEW DELHI PA 2 INSTITUTIONAL AREA, LODI ROAD, NEW DELHI 110 003, INDIA SN 0256-4602 J9 IETE TECH REV JI IETE Tech. Rev. PD NOV-DEC PY 1998 VL 15 IS 6 BP 521 EP 528 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 221YE UT WOS:000081754700016 ER PT J AU Rainwater, JC AF Rainwater, JC TI The cell model of solid-liquid equilibria in two and three dimensions: Analytic spatial free volume integration 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 analytic solution; cell model; hard dumbbell; solid-liquid equilibria ID FLUID EQUILIBRIA; MOLECULES; PHASE AB Monson has successfully calculated the solid-liquid transition temperature of various substances by modeling their molecules as hard dumbbells, with subsequent perturbative addition of quadrupole moment and van der Waals attractive terms. He also has shown that the solid free energy of the reference hard dumbbell system can be calculated accurately from the cell model of Lennard-Jones and Devonshire, and calculated one-body partition functions by Monte Carlo integration. In this work it is shown that For fixed orientation of the test molecule, the free volume can be calculated in closed form, thereby requiring numerical integration only over angular variables. The calculation is explicitly performed in two dimensions, and the feasibility of the method is demonstrated in three dimensions. C1 Natl Inst Stand & Technol, Phys & Chem Propert Div, Boulder, CO 80303 USA. RP Rainwater, JC (reprint author), Natl Inst Stand & Technol, Phys & Chem Propert Div, 325 Broadway, Boulder, CO 80303 USA. NR 14 TC 3 Z9 3 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1998 VL 19 IS 6 BP 1523 EP 1533 PG 11 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 158ZR UT WOS:000078147800003 ER PT J AU Gay, SC Beale, PD Rainwater, JC AF Gay, SC Beale, PD Rainwater, JC TI Solid-fluid phase coexistence of hard heteronuclear dumbbells via cell theory and Monte Carlo simulation 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 cell model; hard dumbbells; heteronuclear; Monte Carlo simulation; solid-fluid equilibrium ID EQUILIBRIA; EQUATION; STATE AB We study the solid-fluid equilibria of hard heteronuclear dumbbells using cell theory and isobaric ensemble Monte Carlo simulations. Calculations for six cases of L* (bond length) and sigma* (sphere diameter ratio) near the homonuclear limit are discussed with two base-centered monoclinic orientationally-ordered crystal structures which have been considered. The two crystal structures exhibit nearly identical properties at freezing within the accuracy of the calculations for the cases we present. The reduced pressure at coexistence increases with decreasing sigma*. C1 Natl Inst Stand & Technol, Phys & Chem Propert Div, Boulder, CO 80303 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Rainwater, JC (reprint author), Natl Inst Stand & Technol, Phys & Chem Propert Div, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 5 Z9 5 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1998 VL 19 IS 6 BP 1535 EP 1544 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 158ZR UT WOS:000078147800004 ER PT J AU Kaschnitz, E McClure, JL Cezairliyan, A AF Kaschnitz, E McClure, JL Cezairliyan, A TI Radiance temperatures (in the wavelength range 530 to 1500 nm) of nickel at its melting point by a false-heating technique 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 emissivity (normal spectral); high-speed pyrometry; high temperature fixed points; melting; pyrometry; nickel; radiance temperature ID NIOBIUM AB The radiance temperatures (at seven wavelengths in the range 530 to 1500 nm) of nickel at its melting point were measured by a pulse-heating technique. The method is based on rapid resistive self heating of the specimen from room temperature to its melting point in less than is and on simultaneously measuring specimen radiance temperatures every 0.5 ms. Melting of the specimen was manifested by a plateau in the radiance temperature-versus-time Function For each wavelength. The melting-point radiance temperatures for a given specimen were determined by averaging the measured temperatures along the plateau at each wavelength. The melting-point radiance temperatures for nickel, as determined by averaging the results at each wavelength for 25 specimens, are: 1641 K at 530 nm, 1615 K at 627 nm, 1606 K at 657 nm, 1589 K at 722 nm, 1564 K at 812 nm, 1538 K at 908 nm, and 1381 K at 1500 nm. Based on uncertainties arising from pyrometry and specimen conditions, the combined uncertainty (two standard-deviation level) is about +/-6 K for the reported values in the range 530 to 900 nm and is about +/-8 K for the reported value at 1500 nm. C1 NIST, Div Met, Gaithersburg, MD 20899 USA. Osterreich Giesserei Inst, A-8700 Leoben, Austria. RP McClure, JL (reprint author), NIST, Div Met, Gaithersburg, MD 20899 USA. NR 15 TC 8 Z9 8 U1 0 U2 0 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 1998 VL 19 IS 6 BP 1637 EP 1646 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 158ZR UT WOS:000078147800014 ER PT J AU Matrosov, SY AF Matrosov, SY TI A dual-wavelength radar method to measure snowfall rate SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SIZE SPECTRA; PRECIPITATION; REFLECTIVITY AB A dual-wavelength radar method to estimate snowfall rate has been developed. The method suggests taking simultaneous and collocated reflectivity measurements at two radar wavelengths. Snowfall backscattering at one of these wavelengths should be in the Rayleigh regime or sufficiently close to this regime, while backscattering at the other wavelength should be substantially outside this regime for typical snowflake sizes. Combinations of K-a-band (for a shorter wavelength) and X-, C-, or S-band (for a longer wavelength) radar measurements satisfy this requirement. The logarithmic difference between reflectivities at these two wavelengths provides an independent estimate of snowflake median size D-m, which exhibits a very low sensitivity to snowflake density and details of the size distribution. The estimates of D-m and radar reflectivities Z(e) at the longer wavelength are then used to obtain snowfall rate R from the Z(e)-R-D-m relationships, which have a snowflake effective density rho(e) as a "tuning" parameter. The independent information about snowflake characteristic size accounts for much of the improvement of the dual-wavelength method over traditional, single-parameter Z(e)-R relationships. The paper also presents experimental data collected during January-March 1996, near Boulder, Colorado, with the National Oceanic and Atmospheric Administration's K-a- and X-band radars. The radar data were supplemented by simultaneous ground measurements of snow accumulation. Comparisons of the ground and dual-wavelength radar measurements indicate that a tuning value rho(e) of about 0.03-0.04 g cm(-3) provides a good match with surface-observed snow accumulations. Differences in dual-wavelength radar estimates of accumulation for rho(e) between 0.03 and 0.04 g cm(-3) are usually within 25%, while existing X-band, single parameter Z(e)-R relationships yield accumulations that differ by as much as a factor of 4. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Matrosov, SY (reprint author), NOAA, R E ET6, ETL, 325 Broadway, Boulder, CO 80303 USA. NR 19 TC 44 Z9 44 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD NOV PY 1998 VL 37 IS 11 BP 1510 EP 1521 DI 10.1175/1520-0450(1998)037<1510:ADWRMT>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 144CH UT WOS:000077295800011 ER PT J AU Balzar, D Von Dreele, RB Bennett, K Ledbetter, H AF Balzar, D Von Dreele, RB Bennett, K Ledbetter, H TI Elastic-strain tensor by Rietveld refinement of diffraction measurements SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NEUTRON-DIFFRACTION; TEXTURE ANALYSIS; COMPOSITE-MATERIALS; RESIDUAL-STRESSES; SPECTRA AB A procedure to obtain all components of the elastic-strain tensor by simultaneous Rietveld refinement of diffraction patterns collected at different specimen orientations is described. The refined lattice parameters yield the hydrostatic strain component. If the lattice constants of the unstrained reference specimen are not known, the deviatoric strain tensor can still be determined. An anisotropic strain component may be refined for cubic and hexagonal crystal structures along with the isotropic. The method is applied to Al/SiC (short whisker) composites and systematic errors are assessed. (C) 1998 American Institute of Physics. [S0021-8979(98)00320-X]. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Balzar, D (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, 325 Broadway, Boulder, CO 80303 USA. NR 36 TC 17 Z9 17 U1 2 U2 7 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 1998 VL 84 IS 9 BP 4822 EP 4833 DI 10.1063/1.368724 PG 12 WC Physics, Applied SC Physics GA 128VF UT WOS:000076428500026 ER PT J AU Gfroerer, TH Cornell, EA Wanlass, MW AF Gfroerer, TH Cornell, EA Wanlass, MW TI Efficient directional spontaneous emission from an InGaAs/InP heterostructure with an integral parabolic reflector SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LIGHT-EMITTING-DIODES; AUGER RECOMBINATION AB In order to increase the radiative efficiency and directivity of spontaneous emission from a lattice-matched InGaAs/InP heterostructure, we have polished the substrate into a parabolic reflector. We combine optical and thermal measurements to obtain the absolute external efficiency over a wide range of carrier densities. Using a simple model, the measurement is used to determine interface, radiative, and Auger recombination rates in the active material. At the optimal density, the quantum efficiency exceeds 60% at room temperature. The divergence of the emitted light is less than 20 degrees. In fact, the beam profile is dominated by a 6 degrees wide lobe that can be swept across the field of emission by changing the excitation position. This suggests a way to create an all-electronic scanned light beam. (C) 1998 American Institute of Physics. [S0021-8979(98)06721-8]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Gfroerer, TH (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 9 TC 17 Z9 17 U1 0 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 1 PY 1998 VL 84 IS 9 BP 5360 EP 5362 DI 10.1063/1.368790 PG 3 WC Physics, Applied SC Physics GA 128VF UT WOS:000076428500108 ER PT J AU Magee, JW Kagawa, N AF Magee, JW Kagawa, N TI Specific heat capacity at constant volume for {xNH(3)+(1-x)H2O} at temperatures from 300 to 520 K and pressures to 20 MPa SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article AB Specific heat capacities at constant volume (c(v)) of {xNH(3) + (1 - x)H2O} (x approximate to 0.7, 0.8, 0.9) mixtures were measured with an adiabatic calorimeter. Temperatures ranged from 300 K to 520 K, and pressures ranged from 3 MPa to 20 MPa. Measurements were conducted on single-phase liquid and compressed gaseous samples. The mixtures were gravimetrically prepared from high-purity substances and verified by chemical analysis. Density was reported for initial and final end points during each calorimetric experiment. The principal sources of uncertainty are the temperature rise measurement and the change-of-volume work adjustment. The expanded relative uncertainty (with a coverage factor k = 2 and thus a 2-standard-deviation estimate) for c(v) is estimated to be 1% for liquid phase and 4% for gaseous results, and for density it is 0.2%. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Boulder, CO 80303 USA. Natl Def Acad, Dept Appl Phys, Yokosuka, Kanagawa 239, Japan. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 8 TC 10 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 1998 VL 43 IS 6 BP 1082 EP 1090 DI 10.1021/je980134g PG 9 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 140VF UT WOS:000077108500036 ER PT J AU Heller, SR AF Heller, SR TI Corel GALLERY 1,000,000, Version 3.0 SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Software Review C1 NIST, SRD, Gaithersburg, MD 20899 USA. RP Heller, SR (reprint author), NIST, SRD, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD NOV-DEC PY 1998 VL 38 IS 6 BP 1249 EP 1249 DI 10.1021/ci980265l PG 1 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 142EE UT WOS:000077186300038 ER PT J AU Lugez, CL Jacox, ME Johnson, RD AF Lugez, CL Jacox, ME Johnson, RD TI Matrix isolation study of the interaction of excited neon atoms with CCl4: Infrared spectra of the ion products and of Cl2CCl center dot center dot Cl SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISSOCIATIVE ELECTRON-ATTACHMENT; MOLECULAR-IONS; SOLID NEON; VIBRATIONAL-SPECTRA; CARBON-TETRACHLORIDE; AB-INITIO; GAS-PHASE; ARGON; TETRACHLOROMETHANE; PHOTOIONIZATION AB When a Ne:CCl4 sample is codeposited at approximately 5 K with a beam of neon atoms that have been excited in a microwave discharge, the infrared spectrum of the resulting deposit includes prominent absorptions not only of CCl3 but also of several other neutral and ionic species. The absorptions assigned to CCl3+, CCl2+, and CCl+ are consistent with previous spectroscopic identifications of these species. As at lower energies, the Cl4CCl .. Cl isomer of CCl4 contributes to the product spectrum. Higher level ab initio calculations of the fundamental vibrations of this isomer and of its carbon-13 substituted counterpart give improved agreement with the experimentally observed infrared spectrum and, together with the results of a supplementary experiment, provide further support for the assignment of a structured absorption near 500 cm(-1) to this species, rather than to Cl-3(+). Uncharged Cl2CCl .. Cl is readily destroyed by visible radiation, with concomitant growth in the absorptions of CCl4. Photodestruction of ionic species occurs in the ultraviolet spectral region. Evidence is presented for the stabilization of Cl2CCl .. Cl- and of Cl3CCl- in these experiments. The latter species undergoes photodestruction in the near infrared spectral region. Two absorptions are tentatively assigned to the ClCCl .. Cl- fragment ion. [S0021-9606(98)00841-1]. [S0021-9606(98)00841-1]. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. US Dept Commerce, Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 69 TC 12 Z9 12 U1 0 U2 6 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 1 PY 1998 VL 109 IS 17 BP 7147 EP 7156 DI 10.1063/1.477397 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 132KY UT WOS:000076630100013 ER PT J AU Kishore, N Tewari, YB Goldberg, RN AF Kishore, N Tewari, YB Goldberg, RN TI An investigation of the equilibrium of the reaction {L-aspartate(aq) plus 2-oxoglutarate(aq) = oxaloacetate(aq) plus L-glutamate(aq)} SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE aspartate transaminase; enthalpy; equilibrium constant; L-glutamate; oxaloacetate; 2-oxoglutarate ID THERMODYNAMICS AB Apparent equilibrium constants have been measured for the following biochemical reaction: L-aspartate(aq) + 2-oxoglutarate(aq) = oxaloacetate(aq) + L-glutamate (aq). This reaction, catalysed by aspartate transaminase, alas studied over the ranges 283.15 less than or equal to T/K less than or equal to 303.15, 6.94 less than or equal to pH less than or equal to 7.13, and 0.163 less than or equal to I-m/(mol.kg(-1)) less than or equal to 0.167, where T is temperature and I-m is ionic strength. The instability of the oxaloacetate in solution required the use of an experimental procedure that was brief. Thus, the procedure used was to measure the change in the chromatographic response Delta R of the oxaloacetate chromatographic peak that accompanied the reaction. Values of Delta R were measured for several solutions under near equilibrium conditions. The chromatographic response Delta R is expected to be zero for a solution that is at equilibrium with regard to the above reaction and prior to the addition of the enzyme. The results were used to calculate the standard molar Gibbs energy change Delta(r)G(m)degrees = (4.82 + 0.21) kJ.mol(-1), the equilibrium constant K = (0.143 +/- 0.012), the standard molar enthalpy change Delta(r)H(m)degrees = (1.9 +/- 2.9) kJ.mol(-1), and the standard molar entropy change Delta(r)S(m)degrees = -(10 +/- 10) J.K-1.mol(-1) for the following chemical reference reaction at T = 298.15 K and I-m = 0: L-aspartate(-) (aq) + 2-oxoglutarate(2-) (aq) = oxaloacetate(2-) (aq) + L-glutamate(-) (aq). Under near physiological conditions (T = 311.15 K, pH = 7.0, I-m = 0.25 mol.kg(-1)) the apparent equilibrium constant K' for the overall biochemical reaction is calculated to have the value 0.147; the standard transformed Gibbs energy change Delta(r)G(m)'degrees = 4.96 kJ.mol(-1) under these conditions. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Kishore, N (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 26 TC 6 Z9 6 U1 0 U2 3 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 1998 VL 30 IS 11 BP 1373 EP 1384 DI 10.1006/jcht.1998.0404 PG 12 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 145PM UT WOS:000077380300008 ER PT J AU Broccoli, AJ Lau, NC Nath, MJ AF Broccoli, AJ Lau, NC Nath, MJ TI The cold ocean warm land pattern: Model simulation and relevance to climate change detection SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; ATMOSPHERE MODEL; NORTHERN-HEMISPHERE; TELECONNECTION PATTERNS; TRANSIENT RESPONSES; VERTICAL STRUCTURE; GRADUAL CHANGES; MEAN RESPONSE; INCREASED CO2; EL-NINO AB Surface air temperatures from a 1000-yr integration of a coupled atmosphere-ocean model with constant forcing are analyzed by using a method that decomposes temperature variations into a component associated with a characteristic spatial structure and a residual. The structure function obtained from the coupled model output is almost identical to the so-called cold ocean-warm land (COWL) pattern based on observations, in which above-average spatial mean temperature is associated with anomalously cold oceans and anomalously warm land. This pattern features maxima over the high-latitude interiors of Eurasia and North America. The temperature fluctuations at the two continental centers exhibit almost no temporal correlation with each other. The temperature variations at the individual centers are related to teleconnection patterns in sea level pressure and 500-mb height that are similar to those identified in previous observational and modeling studies. As in observations, variations in the polarity and amplitude of this structure function are an important source of spatially averaged surface air temperature variability. Results from parallel integrations of models with more simplified treatments of the ocean confirm that the contrast in thermal inertia between land and ocean is the primary factor for the existence of the COWL pattern, whereas dynamical air-sea interactions do not play a significant role. The internally generated variability in structure function amplitude in the coupled model integration is used to assess the importance of the upward trend in the amplitude of the observed structure function over the last 25 yr. This trend, which has contributed to the accelerated warming of Northern Hemisphere temperature over recent decades, is unusually large compared with the trends generated internally by the coupled model. If the coupled model adequately estimates the internal variability of the real climate system, this would imply that the recent upturn in the observed structure function may not be purely a manifestation of unforced variability. A similar monotonic trend occurs when the same methodology is applied to a model integration with time-varying radiative forcing based on past and future CO, and sulfate aerosol increases. This finding illustrates that this decomposition methodology yields ambiguous results when two distinct spatial patterns, the "natural" COWL pattern (i.e., that associated with internally generated variability) and the anthropogenic fingerprint, are present in the simulated climate record. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Broccoli, AJ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308,Forrestal Campus,US Rt 1, Princeton, NJ 08542 USA. RI Broccoli, Anthony/D-9186-2014 OI Broccoli, Anthony/0000-0003-2619-1434 NR 40 TC 35 Z9 35 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1998 VL 11 IS 11 BP 2743 EP 2763 DI 10.1175/1520-0442(1998)011<2743:TCOWLP>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YF UT WOS:000077171400002 ER PT J AU Liebmann, B Marengo, JA Glick, JD Kousky, VE Wainer, IC Massambani, O AF Liebmann, B Marengo, JA Glick, JD Kousky, VE Wainer, IC Massambani, O TI A comparison of rainfall, outgoing longwave radiation, and divergence over the Amazon Basin SO JOURNAL OF CLIMATE LA English DT Article ID VARIABILITY; CONVECTION AB Observed rainfall. outgoing longwave radiation (OLR), divergence, and precipitation from the reanalysis project of the National Centers for Environmental Prediction and die National Center for Atmospheric Research art: compared over the Amazon Basin. The spatial pattern of the mean and the phase of the annual cycle generally compare well. except that the amplitude of the annual cycle of model precipitation is much smaller than observed. On 10-30-day timescales. it is shown that averaging stations within a 5 degrees radius is approximately equivalent to total wavenumber 20 (T20) spatial scale. although it is more important to have a high density of stations than an exact match of spatial scales. Ideally, there should be one station per 20 000 km(2). On 10-30-day scales, observed rainfall is best correlated with OLR. Correlations between OLR and 150-mb divergence are larger than between observed rainfall and divergence or between rainfall and model precipitation. For example, if 10-30-day filtered OLR and divergence are truncated at T20 and rainfall is averaged to include stations within a 5 degrees radius. OLR is correlated with rainfall at about -0.6, OLR is correlated with divergence at about -0.35, and rainfall is correlated with divergence at about 0.2. At least part of the lack of correlation is due to inadequate spatial sampling of rainfall. Correlations improve with larger spatial scale. The major seasonal transitions from dry to rainy regimes are captured well by OLR but not by the model quantities. The mean diurnal cycle is represented reasonably by 150-mb divergence. C1 Univ Colorado, Climate Diagnost Ctr, Boulder, CO 80309 USA. Natl Inst Space Studies, Ctr Weather Predict & Climate Studies, Cachoeira Paulista, Brazil. NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, Washington, DC 20233 USA. Univ Sao Paulo, Dept Phys Oceanog, Sao Paulo, Brazil. Univ Sao Paulo, Dept Atmospher Sci, Sao Paulo, Brazil. RP Liebmann, B (reprint author), Univ Colorado, CIRES, Campus Box 449, Boulder, CO 80309 USA. RI Marengo, Jose /J-9382-2012; Wainer, Ilana/B-4540-2011 OI Marengo, Jose /0000-0002-8154-2762; Wainer, Ilana/0000-0003-3784-623X NR 24 TC 34 Z9 34 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1998 VL 11 IS 11 BP 2898 EP 2909 DI 10.1175/1520-0442(1998)011<2898:ACOROL>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YF UT WOS:000077171400012 ER PT J AU Yang, XQ Anderson, JL Stern, WF AF Yang, XQ Anderson, JL Stern, WF TI Reproducible forced modes in AGCM ensemble integrations and potential predictability of atmospheric seasonal variations in the extratropics SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; LONG-RANGE PREDICTION; INTERANNUAL VARIABILITY; GCM SIMULATION; SST ANOMALIES; FORECASTS; UTILITY AB An approach to assess the potential predictability of the extratropical atmospheric seasonal variations in an ensemble of atmospheric general circulation model (AGCM) integrations has been proposed in this study by isolating reproducible forced modes and examining their contributions to the local ensemble mean. The analyses are based on the monthly mean output of an eight-member ensemble of 10-yr Atmospheric Model Intercomparison Project integrations with a T42L18 AGCM. An EOF decomposition applied to the ensemble anomalies shows that there exist some forced modes that are less affected by the internal process and thus appear to be highly reproducible. By reconstructing the ensemble in terms of the more reproducible forced modes and by developing a quantitative measure, the potential predictability index (PPI), which combines the reproducibility with the local variance contribution, the local ensemble mean over some selective geographic areas in the extratropics was shown to result primarily from reproducible forced modes: rather than internal chaotic fluctuations. Over those regions the ensemble mean is potentially predictable. Extratropical potentially predictable regions are found mainly over North America and part of the Asian monsoon regions. Interestingly. the potential predictability over some preferred areas such as Indian monsoon areas and central Africa occasionally results primarily from non-ENSO-related boundary forcing. although ENSO forcing generally dominates over most of the preferred areas. The quantitative analysis of the extratropical potential predictability with PPI has shown chat the preferred geographic areas have obvious seasonality. For the 850-hPa temperature, for example, potentially predictable regions during spring and winter are confined to Alaska, northwest Canada, and the southeast United States, the traditional PNA region, while during summer and fall they are favored over the middle part of North America. It has also been shown that the boreal summer season (June-August) possesses the largest potentially predictable area, which seems to indicate that it is a favored season for the extratropical potential predictability. On the contrary, boreal winter (December-February) appears to have a minimum area of extratropical potential predictability. The results have been compared with the more traditional statistical tests for potential predictability and with observations from the National Centers for Environmental Prediction reanalysis, which indicates that the PPI analysis proposed here is successful in revealing extratropical potential predictability determined by the external forcing. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Yang, XQ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Forrestal Campus,US Route 1,POB 308, Princeton, NJ 08542 USA. EM xqy@gfdl.gov RI Yang, Michael/G-9716-2013 NR 33 TC 29 Z9 40 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1998 VL 11 IS 11 BP 2942 EP 2959 DI 10.1175/1520-0442(1998)011<2942:RFMIAE>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YF UT WOS:000077171400015 ER PT J AU Janowiak, JE Gruber, A Kondragunta, CR Livezey, RE Huffman, GJ AF Janowiak, JE Gruber, A Kondragunta, CR Livezey, RE Huffman, GJ TI A comparison of the NCEP-NCAR reanalysis precipitation and the GPCP rain gauge-satellite combined dataset with observational error considerations SO JOURNAL OF CLIMATE LA English DT Article ID GLOBAL PRECIPITATION; CLIMATOLOGY PROJECT; NASA/DAO REANALYSES; TROPICAL PACIFIC; NCEP/NCAR; OSCILLATION; HEMISPHERE; PATTERNS AB The Global Precipitation Climatology Project (GPCP) has released monthly mean estimates of precipitation that comprise gauge observations and satellite-derived precipitation estimates. Estimates of standard random error for each month at each grid location are also provided in this data release. One of the primary intended uses of this dataset is the validation of climatic-scale precipitation fields that are produced by numerical models. Nearly coincident with this dataset development, the National Centers for Environmental Prediction and the National Center for Atmospheric: Research have joined in a cooperative effort to reanalyze meteorological fields from the present back to the 1940s using a fixed state-of-the-art data assimilation system and large input database. In this paper, monthly accumulations of reanalysis precipitation are compared with the GPCP combined rain gauge-satellite dataset over the period 1988-95. A unique feature of this comparison is the use of standard error estimates that are contained in the GPCP combined dataset. These errors are incorporated into the comparison to provide more realistic assessments of the reanalysis model performance than could be attained by using only the mean fields. Variability on timescales from intraseasonal to interannual are examined between the GPCP and reanalysis precipitation. While the representation of large-scale features compares well between the two datasets, substantial differences are observed on regional scales. This result is not unexpected since present-day data assimilation systems are not designed to incorporate observations of precipitation. Furthermore, inferences of deficiencies in the reanalysis precipitation should nor be projected to other fields in which observations have been assimilated directly into the reanalysis model. C1 NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD USA. NOAA, NESDIS, Res Off, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. RP Janowiak, JE (reprint author), NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, 4700 Silver Hill Rd,Room 605,Stop 9910, Washington, DC 20233 USA. EM John.janowiak@noaa.gov RI Huffman, George/F-4494-2014 OI Huffman, George/0000-0003-3858-8308 NR 39 TC 100 Z9 103 U1 0 U2 6 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 1998 VL 11 IS 11 BP 2960 EP 2979 DI 10.1175/1520-0442(1998)011<2960:ACOTNN>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YF UT WOS:000077171400016 ER PT J AU Markowski, PM Stensrud, DJ AF Markowski, PM Stensrud, DJ TI Mean monthly diurnal cycles observed with PRE-STORM surface data SO JOURNAL OF CLIMATE LA English DT Article ID PLAINS SEVERE-STORM; BOUNDARY-LAYER; UNITED-STATES; MESOSCALE CIRCULATIONS; SOIL-MOISTURE; CONVECTIVE CLOUDS; BUDGET ANALYSIS; SQUALL-LINE; PRECIPITATION; ENVIRONMENT AB Data from 84 surface mesonetwork stations deployed across Oklahoma and Kansas are used to calculate monthly mean diurnal cycles at each mesonetwork site during May and June of 1985 during the Preliminary Regional Experiment for Stormscale Operational and Research Meteorology (PRE-STORM). The horizontal variations in mean monthly temperatures and specific humidities are large, even though this experimental domain covers only a portion of each state. Landscape differences cause much of this variation, with the harvesting of winter wheat over a large region of Oklahoma in late May being one of the more clear factors influencing the surface layer cycles. A subjective classification of the mean monthly diurnal cycles shows that the type of diurnal cycle changes as the vegetation changes. However, this relationship is strongly modified by the effects of convection. Results suggest that the mean diurnal cycles include the effects of convective downdrafts, indicating that the interaction of convection with the atmospheric surface layer is an important process even on monthly timescales. This is important to consider for those trying to evaluate regional climate simulations. C1 NOAA, Natl Severe Storms Lab, ERL, Norman, OK 73069 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. RP Stensrud, DJ (reprint author), NOAA, Natl Severe Storms Lab, ERL, 1313 Halley Circle, Norman, OK 73069 USA. OI Markowski, Paul/0000-0002-4295-3390 NR 50 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1998 VL 11 IS 11 BP 2995 EP 3009 DI 10.1175/1520-0442(1998)011<2995:MMDCOW>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YF UT WOS:000077171400018 ER PT J AU Knipp, DJ Emery, BA Engebretson, M Li, X McAllister, AH Mukai, T Kokubun, S Reeves, GD Evans, D Obara, T Pi, X Rosenberg, T Weatherwax, A McHarg, MG Chun, F Mosely, K Codrescu, M Lanzerotti, L Rich, FJ Sharber, J Wilkinson, P AF Knipp, DJ Emery, BA Engebretson, M Li, X McAllister, AH Mukai, T Kokubun, S Reeves, GD Evans, D Obara, T Pi, X Rosenberg, T Weatherwax, A McHarg, MG Chun, F Mosely, K Codrescu, M Lanzerotti, L Rich, FJ Sharber, J Wilkinson, P TI An overview of the early November 1993 geomagnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EQUATORIAL SPREAD-F; SOLAR-WIND; IONOSPHERIC ELECTRODYNAMICS; MAGNETIC STORMS; POLAR-CAP; PHASE FLUCTUATIONS; PLASMA SHEET; MARCH 28-29; FIELD; THERMOSPHERE AB This paper describes the development of a major space storm during November 2-11, 1993. We discuss the history of the contributing high-speed stream, the powerful combination of solar wind transients and a corotating interaction region which initiated the storm, the high-speed flow which prolonged the storm and the near-Earth manifestations of the storm. The 8-day storm period was unusually long; the result of a high-speed stream (maximum speed 800 km/s) emanating from st distended coronal hole. Storm onset was accompanied by a compression of the entire dayside magnetopause to within geosynchronous Earth orbit(GEO). For nearly 12 hours the near-Earth environment was in a state of tumult. A super-dense plasma sheet was observed at GEO, and severe spacecraft charging was reported. The effects of electrons precipitating into the atmosphere penetrated into the stratosphere. Subauroral electron content varied by 100% and F layer heights oscillated by 200 km. Equatorial plasma irregularities extended in plumes to heights of 1400 km. Later, energetic particle fluxes at GEO recovered and rose by more than an order of magnitude. A satellite anomaly was reported during the interval of high energetic electron flux. Model results indicate an upper atmospheric temperature increase of 200 degrees K within 24 hours of storm onset. Joule heating for the first 24 hours of the storm was more than 3 times that for typical active geomagnetic conditions. We estimate that total global ionospheric heating for the full storm interval was similar to 190 PJ, with 30% of that generated within 24 hours of storm onset. C1 USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Augsburg Coll, Dept Phys, Minneapolis, MN 55454 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi, Japan. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Hiraiso Solar Terr Res Ctr, Ibaraki, Osaka, Japan. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. USAF, Res Lab, Space Vehicles Dirctorate, Hanscom AFB, MA 01731 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. SW Res Inst, San Antonio, TX 78228 USA. IPS Radio & Space Serv, Haymarket, NSW, Australia. RP Knipp, DJ (reprint author), USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. EM knippdj.dfp@usafa.af.mil; emery@ncar.ucar.edu; engebret@augsburg.edu; lix@kitron.Colorado.edu; ahm@ncar.ucar.edu; mukai@fujitubo.gtl.isas.ac.jp; reeves@lanl.gov; T.Obara@crl.go.jp; xqp@cobra.jpl.nasa.gov; rosenberg@uap.umd.edu; allanw@polar.umd.edu; mchargmg.dfp@usafa.af.mil; chunflc.dfp@usafa.af.mil; codrescu@sec.noaa.gov; ljl@physics.belllabs.com; rich@plh.af.mil; sharb@broccoli.space.swri.edu; phil@ips.gov.au RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 92 TC 67 Z9 69 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1998 VL 103 IS A11 BP 26197 EP 26220 DI 10.1029/98JA00762 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 133UX UT WOS:000076705500002 ER PT J AU Kozyra, JU Jordanova, VK Borovsky, JE Thomsen, MF Knipp, DJ Evans, DS McComas, DJ Cayton, TE AF Kozyra, JU Jordanova, VK Borovsky, JE Thomsen, MF Knipp, DJ Evans, DS McComas, DJ Cayton, TE TI Effects of a high-density plasma sheet on ring current development during the November 2-6, 1993, magnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; GEOSYNCHRONOUS ORBIT; GEOMAGNETIC STORMS; MODEL; MAGNETOSPHERE; PROTON; IONS; DYNAMICS; REGIONS; FIELDS AB The growth and recovery of the November 2-6, 1993 magnetic storm was simulated using a drift-loss ring current model that was driven by dynamic fluxes at geosynchronous orbit as an outer boundary condition. During the storm main phase, a high-density plasma sheet was observed by the Los Alamos National Laboratory geosynchronous satellites to move into and flow around the inner magnetosphere over a period of similar to 12 hours [Borovsky et al., 1997; this issue] during the storm main phase. Densities at the leading edge of this structure reached 3 cm(-3) as compared with more typical values <1 cm-3. The factor of 3 change in the plasma sheet density from quiet to active times produced a factor of 3 enhancement in the strength of the simulated ring current. In addition, a short-timescale recovery in the Dst index at 1600 UT on November 4 was driven by changes in the outer boundary condition and appeared even in the absence of collisional losses. An overshoot in the minimum Dst* occurred in the simulated ring current compared with observed values at similar to 0200 UT on November 4 and is taken as evidence of a loss process not included in the ring current-atmosphere interaction model (RAM). The storm onset was associated with a compression of the entire dayside magnetopause to within geostationary orbit starting at 2307 UT and continuing for a half hour. It is suggested that a possible additional loss may have resulted as ions drifted to the compressed dayside magnetopause. In fact such losses were found in another simulation of the inner magnetosphere for the same storm by Freeman et al. [1996]. The energy supplied to the inner magnetosphere, relative to the total energy input during this magnetic storm, was examined by comparing two widely used energy input functions, the epsilon parameter [Akasofu, 1981] and the F parameter [Burton et al., 1975] against energy input to the ring current model based on geosynchronous plasma observations at the outer boundary. It is found that the epsilon parameter [Akasofu,1981] overestimates the ring current energy input compared to the drift-loss model by almost an order of magnitude during the main phase. However, the integrated energy input from epsilon, over the 4 day interval of the storm, is in very good agreement with the total energy input inferred from observations. On the other hand, F more closely approximates the magnitude of the ring current energy input alone as calculated in the drift-loss model. An energy budget is constructed for the storm that shows energy inputs from the solar wind and energy dissipation due to ring current buildup and decay, auroral electron precipitation, Joule heating, ion precipitation, and energy storage in the magnetotail in reasonable balance. The ring current energy input accounts for only 15% of the total dissipated energy in this storm interval. A more complete energy budget that extends to November 11,1993, was compiled by Knipp et al. [this issue]. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Space Phys Lab, Ann Arbor, MI 48109 USA. Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Astrophys & Radiat Measurements Grp, Los Alamos, NM 87545 USA. NOAA, Natl Ctr Environm Predict, Space Environm Ctr, Boulder, CO 80303 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. RP Kozyra, JU (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, Space Phys Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. OI Jordanova, Vania/0000-0003-0475-8743 NR 39 TC 94 Z9 93 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1998 VL 103 IS A11 BP 26285 EP 26305 DI 10.1029/98JA01964 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 133UX UT WOS:000076705500009 ER PT J AU Turner, NE Baker, DN Pulkkinen, TI Singer, HJ Mozer, F Lepping, RP AF Turner, NE Baker, DN Pulkkinen, TI Singer, HJ Mozer, F Lepping, RP TI High-altitude polar cap electric field responses to southward turnings of the interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID IONOSPHERIC CONVECTION PATTERN; MAGNETOSPHERE; RECONNECTION; SUBSTORMS; MODEL AB Interplanetary electric field coupling with the magnetosphere has been analyzed predominantly using data from the Wind magnetometer and the Polar electric field instrument. The coupling was investigated using the Polar Electric Field Instrument (EFI) to measure the electric field in the northern polar cap immediately following sharp southward turnings of the IMF as observed by Wind. Southward turnings were chosen which exhibited a sudden change of the IMF north-south component from B-z > 0 to B-z < 0 (GSM coordinates) after an hour or more of relatively stable conditions, and for which Polar was in the northern polar cap. These Bz changes correspond to B-y changes in the interplanetary electric field. For each of the 30 identified events, a time was estimated for the arrival of the IMF change at the magnetopause using the solar wind speed observed by the Wind Solar Wind Experiment (SWE), and Polar electric field data were examined to identify responses. For many of the selected events (about one third), abrupt changes of state in the magnetospheric electric field were evident with timing that matched the expected solar wind arrival time at Earth. For events for which additional data were available, we conducted in-depth examination of the individual events using IMP 8, Geotail, and GOES 9. In one such event, GOES 9 data showed a substorm growth phase and onset which also corresponded to features in the solar wind observed by Wind, Geotail, and IMP 8. In addition to the individual event studies, a superposed epoch analysis of all available events revealed a consistent rise in the mean polar cap electric field about 15 min following sharp IMF southward turnings. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Turner, NE (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr, Boulder, CO 80303 USA. RI Pulkkinen, Tuija/D-8403-2012; OI Pulkkinen, Tuija/0000-0002-6317-381X; Turner, Niescja/0000-0002-3280-4260 NR 21 TC 2 Z9 2 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1998 VL 103 IS A11 BP 26533 EP 26545 DI 10.1029/98JA01743 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 133UX UT WOS:000076705500027 ER PT J AU Fuller-Rowell, TJ Rishbeth, H Millward, GH Moffett, RJ Quegan, S Aylward, AD AF Fuller-Rowell, TJ Rishbeth, H Millward, GH Moffett, RJ Quegan, S Aylward, AD TI Comment on "Ionospheric F2 layer seasonal and semiannual variations" by G. H. Millward, H.Q Rishbeth, T.J. Fuller-Rowell, A.D. Aylward, S. Quegan, and R.J. Moffett - Reply SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material C1 Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Southampton, Dept Phys, Southampton SO17 1BJ, Hants, England. Univ Sheffield, Sch Math & Stat, Upper Atmosphere Modelling Grp, Sheffield S3 7RH, S Yorkshire, England. UCL, Dept Phys & Astron, Atmospher Phys Lab, London W1P 7PP, England. RP Fuller-Rowell, TJ (reprint author), Univ Colorado, CIRES, Boulder, CO 80303 USA. EM tjfr@sec.noaa.gov; hr@phys.soton.ac.uk; gmillward@sec.noaa.gov; acm@sheffield.ac.uk; s.quegan@sheffield.ac.uk; alan@apg.ph.ucl.ac.uk NR 2 TC 1 Z9 1 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1998 VL 103 IS A11 BP 26763 EP 26763 DI 10.1029/98JA02653 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 133UX UT WOS:000076705500047 ER PT J AU Cornell, EA Hall, DS Matthews, MR Wieman, CE AF Cornell, EA Hall, DS Matthews, MR Wieman, CE TI Having it both ways: Distinguishable yet phase-coherent mixtures of Bose-Einstein condensates SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Quantum Fluids and Solids (QFS98) CY JUN 09-14, 1998 CL AMHERST, MASSACHUSETTS ID SODIUM ATOMS; COLLECTIVE EXCITATIONS; NEUTRAL ATOMS; TRAP; INTERFEROMETER; SCATTERING; STABILITY; NUMBER; SHIFTS; VAPOR AB We have begun a series of experiments on mixed bosonic quantum fluids. Our system is mixed Bose-Einstein condensates in dilute Rb-87. By simultaneously trapping the atoms in two different hyperfine states, rue are able to study the dynamics of component separation and of the relative quantum phase of two interpenetrating condensates. Population can be converted from one state to the other at a rate that is sensitive to the relative quantum phase. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Cornell, EA (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 51 TC 29 Z9 29 U1 2 U2 2 PU PLENUM PUBL CORP 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 1998 VL 113 IS 3-4 BP 151 EP 165 DI 10.1023/A:1022513609071 PG 15 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 139ZH UT WOS:000077060800002 ER PT J AU Bickham, JW Loughlin, TR Calkins, DG Wickliffe, JK Patton, JC AF Bickham, JW Loughlin, TR Calkins, DG Wickliffe, JK Patton, JC TI Genetic variability and population decline in Steller sea lions from the Gulf of Alaska SO JOURNAL OF MAMMALOGY LA English DT Article DE Eumetopius jubattus; Stellar sea lion; endangered species; mitochondrial DNA; control-region sequence; genetic diversity ID EUMETOPIAS-JUBATUS; ABUNDANCE; DNA AB The western stock of the Steller sea lion (Eumetopias jubatus) was listed as endangered in 1997 due to its decline in numbers since the 1960s. We examined haplotypic diversity using nucleotide-sequence analysis of the control region of the mitochondrial DNA (mtDNA) from animals collected in 1976-1978 from the western and central Gulf of Alaska and compared results to previously published data from animals collected in the 1990s from the same geographic areas. No significant differences were found in frequencies of haplotypes between the two time periods, and genotypic diversity was high for all populations and time periods studied. It is concluded that, despite reduction in numbers, populations in the Gulf of Alaska have not lost appreciable genetic diversity, and if populations are allowed to recover, no long-term change in fitness is expected. C1 Texas A&M Univ, Dept Wildlife & Fisheries Sci, College Stn, TX 77843 USA. LGL Ecol Genet, Bryan, TX 77801 USA. Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Alaska Dept Fish & Game, Anchorage, AK 99518 USA. RP Bickham, JW (reprint author), Texas A&M Univ, Dept Wildlife & Fisheries Sci, College Stn, TX 77843 USA. NR 27 TC 30 Z9 30 U1 4 U2 16 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD NOV PY 1998 VL 79 IS 4 BP 1390 EP 1395 DI 10.2307/1383029 PG 6 WC Zoology SC Zoology GA 145PH UT WOS:000077379900029 ER PT J AU Chang, LM Carino, NJ Wang, CB AF Chang, LM Carino, NJ Wang, CB TI Process of in-place evaluation of concrete strength SO JOURNAL OF MATERIALS IN CIVIL ENGINEERING LA English DT Article AB In-place test methods are available that can be used as alternatives to testing field-cured specimens to evaluate concrete strength in a structure. However, in-place test results do not represent the compressive strength of concrete directly but are empirically correlated to the compressive strength. Therefore, to use in-place test methods to estimate the strength of concrete, a preestiablished relationship is required between the in-place test results and standard cylinder test results. In addition, a statistically based procedure is needed for a reliable estimate of concrete strength based on the strength relationship and in-place test results. This paper describes the statistical framework for developing the strength relationship and provides a step-by-step procedure to evaluate the characteristic compressive strength of concrete from in-place test results. Pullout test data are used to illustrate the use of these computational procedures. C1 Purdue Univ, Sch Civil Engn, W Lafayette, IN 47907 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Chang, LM (reprint author), Purdue Univ, Sch Civil Engn, W Lafayette, IN 47907 USA. NR 11 TC 0 Z9 0 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0899-1561 J9 J MATER CIVIL ENG JI J. Mater. Civ. Eng. PD NOV PY 1998 VL 10 IS 4 BP 229 EP 237 DI 10.1061/(ASCE)0899-1561(1998)10:4(229) PG 9 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 130YW UT WOS:000076549100005 ER PT J AU Rossetti, GA Cline, JP Navrotsky, A AF Rossetti, GA Cline, JP Navrotsky, A TI Phase transition energetics and thermodynamic properties of ferroelectric PbTiO3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID LEAD TITANATE; SINGLE-CRYSTALS; BEHAVIOR; SYSTEM AB The ferroelectric phase transition in polycrystalline PbTiO3 was investigated using differential scanning calorimetry and high-resolution x-ray diffraction. The specimen studied was a highly crystalline powder sample carefully prepared by the solution-gelation synthesis technique. The behavior of the excess specific heat, excess enthalpy, excess entropy, and spontaneous tetragonal deformation near the Pm3m <-> P4mm transition was examined. The thermal evolution of the thermodynamic order parameter as obtained from the specific heat measurements was compared to that determined from the behavior of the spontaneous elastic strain. The coefficients of the relevant Landau potential for lead titanate were deduced from these data. The results provided additional information regarding the basic thermodynamic properties of lead titanate and confirmed that a simply formulated Landau-Devonshire polynomial, having temperature independent higher-order dielectric stiffness coefficients, affords a satisfactory and self-consistent description of the single-domain ferroelectric behavior. C1 Northeastern Univ, Dept Chem Engn, Ctr Adv Micrograv Mat Proc, Boston, MA 02115 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Thermochem Facil, Davis, CA 95616 USA. RP Rossetti, GA (reprint author), Northeastern Univ, Dept Chem Engn, Ctr Adv Micrograv Mat Proc, Boston, MA 02115 USA. RI Rossetti, George/E-4401-2014 NR 30 TC 37 Z9 37 U1 2 U2 16 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 1998 VL 13 IS 11 BP 3197 EP 3206 DI 10.1557/JMR.1998.0434 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 134TA UT WOS:000076758200024 ER PT J AU Lee, S Nguyen, T Chin, J Chuang, TJ AF Lee, S Nguyen, T Chin, J Chuang, TJ TI Analysis of the single-fiber fragmentation test SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID FRACTURE-MECHANICS ANALYSIS; ACOUSTIC-EMISSION TECHNIQUE; INTERFACIAL SHEAR-STRENGTH; ELASTIC HALF-SPACE; STRESS TRANSFER; CYLINDRICAL INCLUSION; MATRIX CRACKING; COMPOSITE TEST; INTERPHASE AB An analysis of the single-fiber fragmentation test was investigated. An approximate solution for the stress fields of a fiber embedded in a polymer matrix of different elastic moduli was obtained by the Eshelby method. The fiber was modeled as a prolate spheroid. The axial stress of the fiber increases with increasing aspect ratio and fiber-matrix shear modulus ratio and decreases with increasing matrix and fiber Poisson's ratios. Using this analysis, the fracture stress of a single-fiber fragmentation specimen was derived. The applied stress at fiber fracture decreases monotonically with increasing aspect ratio of the fragmented fiber and increases with increasing fiber and matrix Poisson's ratios. This model is in qualitative agreement with published experimental data. (C) 1998 Kluwer Academic Publishers. C1 NIST, Gaithersburg, MD 20899 USA. RP Nguyen, T (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 33 TC 3 Z9 3 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD NOV 1 PY 1998 VL 33 IS 21 BP 5221 EP 5228 DI 10.1023/A:1004436021358 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 170YD UT WOS:000078834000018 ER PT J AU Ceausu, A Graner, G Burger, H Mkadmi, EB Pracna, P Lafferty, WJ AF Ceausu, A Graner, G Burger, H Mkadmi, EB Pracna, P Lafferty, WJ TI High-resolution study of the first stretching overtones of (H3SiBr)-Br-79 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SAPPHIRE RING LASER; LOCAL MODE LIMIT; ROVIBRATIONAL ANALYSIS; VIBRATIONAL-SPECTRA; FORCE-CONSTANTS; SYMMETRIC TOPS; MONOISOTOPIC (H3SIBR)-BR-79; ROTATIONAL ANALYSIS; INFRARED-SPECTRUM; BANDS AB The Fourier transform infrared spectrum of monoisotopic (H3SiBr)-Br-79 (resolution 7.7 x 10(-3) cm(-1)) was studied from 4200 to 4520 cm(-1), in the region of the first overtones of the Si-H stretching vibration. The investigation of the spectrum revealed the presence of two band systems, the first consisting of one parallel (upsilon(0) = 4340.2002 cm(-1)) and one perpendicular (upsilon(0) = 4342.1432 cm(-1)) strong component, and the second of one parallel (upsilon(0) = 4405.789 cm(-1)) and one perpendicular (upsilon(0) = 4416.233 cm(-1)) weak component. The rovibrational analysis shows strong local perturbations for both strong and weak systems. Seven hundred eighty-one nonzero-weighted transitions belonging to the strong system [the (200) manifold in the local mode picture] were fitted to a simple model involving a perpendicular component interacting by a weak Coriolis resonance with a parallel component. The most severely perturbed transitions (whose \obs-calc\ values exceeded 3 x 10(-3) cm(-1)) were given zero weights. The standard deviations of the fit were 1.0 x 10(-3) and 0.69 x 10(-3) cm(-1) for the parallel and the perpendicular components, respectively. The weak band system, severely perturbed by many "dark" perturbers, was fitted to a model involving one parallel and one perpendicular band, connected by a Coriolis-type resonance. The K" . Delta K = +10 to +18 subbands of the perpendicular component, which showed very high observed - calculated values (similar to 0.5 cm(-1)), were excluded from this calculation. The standard deviations of the fit were 11 x 10(-3) and 13 x 10(-3) cm(-1) for the parallel and the perpendicular components, respectively. (C) 1998 Academic Press. C1 CNRS, Lab Phys Mol & Applicat, F-91405 Orsay, France. Berg Univ Gesamthsch Wuppertal, D-42097 Wuppertal, Germany. J Heyrovsky Inst Phys Chem, CZ-18223 Prague, Czech Republic. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Graner, G (reprint author), CNRS, Lab Phys Mol & Applicat, Bat 350,Campus Orsay, F-91405 Orsay, France. NR 27 TC 2 Z9 2 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD NOV PY 1998 VL 192 IS 1 BP 47 EP 60 DI 10.1006/jmsp.1998.7669 PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 136NM UT WOS:000076865700007 ER PT J AU Stone, SC Philips, LA Fraser, GT Lovas, FJ Xu, LH Sharpe, SW AF Stone, SC Philips, LA Fraser, GT Lovas, FJ Xu, LH Sharpe, SW TI High-resolution microwave and infrared molecular-beam studies of the conformers of 1,1,2,2-tetrafluoroethane SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID RESONANCE OPTOTHERMAL SPECTROSCOPY; VIBRATIONAL FREQUENCIES; AB-INITIO; 1,1,2-TRIFLUOROETHANE; MODE; 1,2-DIFLUOROETHANE; REDISTRIBUTION; SPECTROMETER; STRETCH; ETHANOL AB High-resolution microwave and infrared molecular-beam spectra have been measured far 1,1,2,2-tetrafluoroethane (HFC134). For the higher energy, polar, C-2 symmetry, gauche conformer, microwave spectra have been recorded for the normal and mono-C-13 isotopomers and analyzed to determine a C-C bond length of 1.512(4) Angstrom, in good agreement with a recent ab initio value (MP2/6-31G**) of 1.51.5 Angstrom [S. Papasavva, K. H. Illinger, and J. E. Kenny, J. Phys. Chem. 100, 10100-10110 (1996)]. A tunable microwave-sideband CO2 laser and electric-resonance optothermal spectrometer have been used to measure the infrared spectrum of the upsilon(6), C-C stretch of the gauche conformer near 906 cm(-1). Microwave-infrared double resonance and precise ground state combination differences provided by the microwave measurements guide the assignment of the spectrum. The observation of a c-type spectrum definitively establishes that the upper state vibration is of A symmetry in the C-2 point group. The spectrum is fit to a Watson asymmetric-top Hamiltonian to a standard deviation of 0.24 MHz. A weak perturbation shifts the line positions for transitions near J = K-c = 20 by as much as 12 MHz. The identity of the perturber is unknown. Pulsed slit-jet diode-laser spectra have been recorded for the upsilon(16) vibration of the anti conformer near 1127 cm(-1). An a- and c-type hybrid band is observed, consistent with a B-u symmetry mode. Previous low-resolution studies have attributed the 1127-cm(-1) mode to either a B-u or an A(u) symmetry vibration. A total of 522 nonblended transitions were assigned and fit to determine ground and excited state constants. The ground state constants of A = 5134.952(65) MHz, B = 3148.277(27) MHz, and C = 2067.106(43) MHz are the first experimental determinations of the rotational constants for this conformer. Here, type A standard uncertainties are given in the parentheses. (C) 1998 Academic Press. C1 Cornell Univ, Dept Chem, Ithaca, NY 14853 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Pacific NW Lab, Mol Sci Res Ctr, Richland, WA 99352 USA. RP Stone, SC (reprint author), Cornell Univ, Dept Chem, Ithaca, NY 14853 USA. RI Xu, Li-Hong/J-5095-2015 NR 25 TC 4 Z9 4 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD NOV PY 1998 VL 192 IS 1 BP 75 EP 85 DI 10.1006/jmsp.1998.7664 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 136NM UT WOS:000076865700010 ER PT J AU Winton, M Hallberg, R Gnanadesikan, A AF Winton, M Hallberg, R Gnanadesikan, A TI Simulation of density-driven frictional downslope flow in Z-coordinate ocean models SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CIRCULATION; NORTH AB An important component of the ocean's thermohaline circulation is the sinking of dense water from continental shelves to abyssal depths. Such downslope flow is thought to be a consequence of bottom stress retarding the alongslope flow of density-driven plumes. In this paper the authors explore the potential for explicitly simulating this simple mechanism in z-coordinate models. A series of experiments are performed using a twin density coordinate model simulation as a standard of comparison. The adiabatic nature of the experiments and the importance of bottom slope make it more likely that the density-coordinate model will faithfully reproduce the solution. The difficulty of maintaining the density signal as the plume descends the slope is found to be the main impediment to accurate simulation in the z-coordinate model. The results of process experiments suggest that the model solutions will converge when the z-coordinate model has sufficient vertical resolution to resolve the bottom viscous layer and horizontal grid spacing equal to its vertical grid spacing divided by the maximum slope. When this criterion is met it is shown that the z-coordinate model converges to an analytical solution for a simple two-dimensional flow. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Winton, M (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 14 TC 89 Z9 90 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD NOV PY 1998 VL 28 IS 11 BP 2163 EP 2174 DI 10.1175/1520-0485(1998)028<2163:SODDFD>2.0.CO;2 PG 12 WC Oceanography SC Oceanography GA 145JL UT WOS:000077367400004 ER PT J AU Bundy, MH Gross, TF Vanderploeg, HA Strickler, JR AF Bundy, MH Gross, TF Vanderploeg, HA Strickler, JR TI Perception of inert particles by calanoid copepods: behavioral observations and a numerical model SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID FRESH-WATER COPEPOD; LOW REYNOLDS-NUMBER; FORAGING BEHAVIOR; FEEDING-BEHAVIOR; MARINE COPEPODS; FOOD SELECTION; PREY DETECTION; FIRST ANTENNAE; DIAPTOMUS; CAPTURE AB High-resolution video showed freely swimming Diaptomus sicilis attacking and capturing inert 50 mu m polystyrene beads that were outside the influence of the copepod feeding current. The beads were frequently more than half a body length away and were attacked after the 'bow wake' of the moving copepod displaced the bead away from the copepod. To investigate the hypothesis that deformation of streamlines around the copepod and its first antennae stimulated the attack response, a finite element numerical model was constructed. The model described the fluid interactions between a large object approaching a smaller object in a laminar flow at Reynolds number 5, which is characteristic of the fluid regime experienced by foraging copepods. The model revealed that fluid velocity fluctuations and streamline deformations arose in the region between the two objects as separation distance between the objects decreased. The video observations and the model results support the hypotheses that chemoreception is not required for the detection and capture of large phytoplankton cells [Vanderploeg et al., in Hughes, R.N. (ed.), Behavioral Mechanisms of Food Selection. NATO ASI Series G20, 1990; DeMott and Watson, J. Plankton Res., 13, 1203-1222, 1991], and that swimming behavior plays an integral role in prey detection. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Skidaway Inst Oceanog, Savannah, GA 31411 USA. Univ Wisconsin, Ctr Great Lakes Studies, Milwaukee, WI USA. RP Bundy, MH (reprint author), Acad Nat Sci Estuarine Res Ctr, 10545 Mackall Rd, St Leonard, MD 20685 USA. RI Strickler, J. Rudi/A-8926-2009; OI Vanderploeg, Henry/0000-0003-1358-8475 NR 54 TC 38 Z9 38 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD NOV PY 1998 VL 20 IS 11 BP 2129 EP 2152 DI 10.1093/plankt/20.11.2129 PG 24 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 138MG UT WOS:000076975200006 ER PT J AU Perrin, A Flaud, JM Goldman, A Camy-Peyret, C Lafferty, WJ Arcas, P Rinsland, CP AF Perrin, A Flaud, JM Goldman, A Camy-Peyret, C Lafferty, WJ Arcas, P Rinsland, CP TI NO2 and SO2 line parameters: 1996 HITRAN update and new results SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID HIGH-RESOLUTION MEASUREMENTS; ABSORPTION CROSS-SECTION; ELECTRON-SPIN ROTATION; TEMPERATURE-DEPENDENCE; CONTACT RESONANCES; NITROGEN-DIOXIDE; SPECTRAL REGION; SULFUR-DIOXIDE; (NO2)-N-14-O-16; INTENSITIES AB The purpose of the present paper is to describe recent progress in the study of two molecules of atmospheric interest, namely nitrogen dioxide (NO2) and sulfur dioxide (SO2). This progress has led to updates in the 1996 version of the HITRAN database. Also some recommendations for the future will be given. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Paris Sud, CNRS, Photophys Mol Lab, F-91405 Orsay, France. Univ Denver, Dept Phys, Denver, CO 80208 USA. Univ Paris Sud, CNRS, Lab Phys Mol & Applicat, F-91405 Orsay, France. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23682 USA. RP Perrin, A (reprint author), Univ Paris Sud, CNRS, Photophys Mol Lab, Bat 210,Campus Orsay, F-91405 Orsay, France. NR 56 TC 20 Z9 20 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD NOV PY 1998 VL 60 IS 5 BP 839 EP 850 DI 10.1016/S0022-4073(98)00086-7 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 129YR UT WOS:000076492100010 ER PT J AU Cage, ME Jeffery, A Elmquist, RE Lee, KC AF Cage, ME Jeffery, A Elmquist, RE Lee, KC TI Calculating the effects of longitudinal resistance in multi-series-connected quantum Hall effect devices SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ac quantum Hall effect; equivalent electrical circuit; longitudinal resistance; multi-series connections; quantized Hall resistance ID AC MEASUREMENTS AB Many ac quantized Hall resistance experiments have measured significant values of ac longitudinal resistances under temperature and magnetic field conditions in which the de longitudinal resistance values were negligible. We investigate the effect of nonvanishing ac longitudinal resistances on measurements of the quantized Hall resistances by analyzing equivalent circuits of quantized Hall effect resistors. These circuits are based on ones reported previously for de quantized Hall resistors, but use additional resistors to represent longitudinal resistances. For simplification, no capacitances or inductances are included in the circuits. The analysis is performed for many combinations of multi-series connections to quantum Hall effect devices. The exact algebraic solutions for the quantized Hall resistances under these conditions of finite ac longitudinal resistances provide corrections to the measured quantized Hall resistances, but these corrections do not account for the frequency dependences of the ac quantized Hall resistances reported in the literature. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cage, ME (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 11 Z9 11 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1998 VL 103 IS 6 BP 561 EP 592 DI 10.6028/jres.103.037 PG 32 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600001 PM 28009360 ER PT J AU Cage, ME Jeffery, A AF Cage, ME Jeffery, A TI A problem in ac quantized Hall resistance measurements and a proposed solution SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ac quantum Hall effect; capacitance-to-shield; equivalent electrical circuit; longitudinal resistance; multi-series connections; quantized Hall resistance AB In all experiments reported to date the measured values of the ac quantized Hall resistances R-H varied with the frequency of the applied current, and differed significantly from the de values of R-H, making it difficult to use the ac quantum Hall effect as an absolute impedance standard. We analyze the effects due to the large capacitances-to-shields existing in the sample probes on measurements of R-H to see if this is the source of the problem. Equivalent electrical circuits are utilized; they contain capacitances and leakage resistances to the sample probe shields, longitudinal resistances within the quantized Hall effect devices, and multiple connections to the devices. The algebraic solutions for the R-H values in these circuits reveal large out-of-phase contributions to the quantized Hall voltages V-H that would make it difficult to do accurate measurements with high precision ac bridges. These large out-of-phase contributions could introduce the linear frequency dependences observed in previous R-H measurements. We predict, however, that quadruple-series connections to the quantum Hall devices yield only small out-of-phase contributions to V-H which may allow accurate measurements of the quantity R-H - R-x, where R-x is the longitudinal resistance along the device. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cage, ME (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 3 Z9 3 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1998 VL 103 IS 6 BP 593 EP 604 DI 10.6028/jres.103.038 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600002 PM 28009363 ER PT J AU Zong, Y Datla, RU AF Zong, Y Datla, RU TI Development of a bolometer detector system for the NIST high accuracy infrared spectrophotometer SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE cryogenic bolometer; infrared detector; linearity; noise; spatial response; spectrophotometer ID IR SPECTROPHOTOMETER; COMPOSITE AB A bolometer detector system was developed for the high accuracy infrared spectrophotometer at the National Institute of Standards and Technology to provide maximum sensitivity, spatial uniformity, and linearity of response covering the entire infrared spectral range. The spatial response variation was measured to be within 0.1 %. The linearity of the detector output was measured over three decades of input power. After applying a simple correction procedure, the detector output was found to deviate less than 0.2 % from linear behavior over this range. The noise equivalent power (NEP) of the bolometer system was 6 x 10(-12) W/root Hz at the frequency of 80 Hz. The detector output 3 dB roll-off frequency was 200 Hz. The detector output was stable to within +/- 0.05 % over a 15 min period. These results demonstrate that the bolometer detector system will serve as an excellent detector for the high accuracy infrared spectrophotometer. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Zong, Y (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 12 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 1998 VL 103 IS 6 BP 605 EP 614 DI 10.6028/jres.103.039 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600003 PM 28009364 ER PT J AU Eppeldauer, G AF Eppeldauer, G TI Spectral response based calibration method of Tristimulus colorimeters SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE chromaticity coordinates; color calibration; color temperature; colorimetry; detector standard; photometry; spectral response; tristimulus values ID ACCURACY CRYOGENIC RADIOMETER; NATIONAL-INSTITUTE; TRAP DETECTOR; SCALE; STANDARDS AB A new method is described to calibrate tristimulus colorimeters for high accuracy color measurements Instead of traditional lamp standards, modern, high accuracy detector standards are suggested for calibration. After high accuracy absolute spectral response determination of the tristimulus receivers, color (spectral) correction and peak (amplitude) normalization can minimize uncertainties caused by imperfect realizations of the Commission Internationale de l'Eclairage (CIE) color matching functions. As a result of the corrections, stable light sources of different spectral power distributions can be measured with an accuracy dominated by the sub tenths of a percent uncertainty of novel spectral response determinations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Eppeldauer, G (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 24 TC 15 Z9 15 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1998 VL 103 IS 6 BP 615 EP 619 DI 10.6028/jres.103.040 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600004 PM 28009362 ER PT J AU Murthy, AV Tsai, BK Saunders, RD AF Murthy, AV Tsai, BK Saunders, RD TI Aperture proximity effects in high heat flux sensors calibration SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE calibration; heat flux; radiation; sensors AB In the transfer calibration of heat flux sensors, a correction for the irradiance distribution across the sensing area may be required when the sensing areas of the reference and test sensors are different. A method to calculate this correction using well-known equations for the configuration factors is presented. Also, estimates of the correction for test conditions corresponding to the transfer calibration technique in use at the National Institute of Standards and Technology are given. C1 Aero Tech Inc, Hampton, VA 23666 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Murthy, AV (reprint author), Aero Tech Inc, Hampton, VA 23666 USA. NR 2 TC 1 Z9 1 U1 1 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1998 VL 103 IS 6 BP 621 EP 624 DI 10.6028/jres.103.041 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600005 PM 28009369 ER PT J AU Phillips, SD Estler, WT Levenson, MS Eberhardt, KR AF Phillips, SD Estler, WT Levenson, MS Eberhardt, KR TI Calculation of measurement uncertainty using prior information SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Bayesian; bias; error; measurement uncertainty; uncertainty AB We describe the use of Bayesian inference to include prior information about the value of the measurand in the calculation of measurement uncertainty Typical examples show this can, in effect, reduce the expanded uncertainty by up to 85 %. The application of the Bayesian approach to proving workpiece conformance to specification (as given by international standard ISO 14253-1) is presented and a procedure for increasing the conformance zone by modifying the expanded uncertainty guard bands is discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Phillips, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 13 Z9 13 U1 0 U2 5 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1998 VL 103 IS 6 BP 625 EP 632 DI 10.6028/jres.103.042 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600006 PM 28009370 ER PT J AU Shakarji, CM AF Shakarji, CM TI Least-squares fitting algorithms of the NIST algorithm testing system SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE coordinate measuring machine; curve fitting; least-squares fitting; Levenberg-Marquardt; orthogonal distance regression; surface fitting AB This report describes algorithms for fitting certain curves and surfaces to points in three dimensions. All fits are based on orthogonal distance regression. The algorithms were developed as reference software for the National Institute of Standards and Technology's Algorithm Testing System. which has been used for 5 years by NIST and by members of the American Society of Mechanical Engineers' B89.4.10 standards committee. The Algorithm Testing System itself is described only briefly; the main part of this paper covers the general linear algebra, numerical analysis, and optimization methods it employs. Most of the fitting routines rely on the Levenberg-Marquardt optimization routine. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Shakarji, CM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 12 TC 134 Z9 147 U1 2 U2 13 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 1998 VL 103 IS 6 BP 633 EP 641 DI 10.6028/jres.103.043 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 170XD UT WOS:000078831600007 PM 28009376 ER PT J AU Cava, RJ Ramirez, AP Huang, Q Krajewski, JJ AF Cava, RJ Ramirez, AP Huang, Q Krajewski, JJ TI Compounds with the YbFe2O4 structure type: Frustrated magnetism and spin-glass behavior SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID ANTIFERROMAGNET; TRANSITION; Y2MO2O7 AB The YbFe2O4 structure type consists of triangular layers of lanthanide oxygen octahedra stacked with triangular double layers of transition metal oxygen triangular bipyramids. The crystallographic structures determined by neutron diffraction powder profile analysis at 300 and 11 K for new members of this structural family are reported. The compounds are found to be magnetically frustrated, by both lattice geometry and disorder. The magnetic properties of YbCuGaO4, LuCuGaO4, LuZn FeO4, LuCoGaO4, and LuCuFeO4 reveal the effects of total spin, spin mixing, and interaction between spins on different sublattices on the magnetic frustration. The magnetism is increasingly frustrated as the spin on the magnetic ions is decreased, (C) 1998 Academic Press. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, Mat Res Program, College Pk, MD 20742 USA. RP Cava, RJ (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08540 USA. NR 19 TC 31 Z9 31 U1 2 U2 28 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 1 PY 1998 VL 140 IS 2 BP 337 EP 344 DI 10.1006/jssc.1998.7896 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 141AB UT WOS:000077119500022 ER PT J AU Gillaspy, JD Parks, DC Ratliff, LP AF Gillaspy, JD Parks, DC Ratliff, LP TI Masked ion beam lithography with highly charged ions SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 42nd International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIPBN) CY MAY 26-29, 1998 CL CHICAGO, IL ID HOLLOW ATOMS; SURFACE; NEUTRALIZATION; EQUILIBRATION; DEPENDENCE; SIZE; SIO2 AB Masked ion beam lithography using highly charged ions is demonstrated for the first time by producing an array of hundreds of ordered micrometer wide dots using Xe44+ on poly(methylmethacrylate) resist. At low dose, exposure of the resist is incomplete and isolated single-ion impact sites can be seen within the exposed areas. Atomic force microscope images of the single-ion impact sites show Craters with a width of 24 nm. At high dose, the exposure is complete and the dot morphology is consistent with limitations from the mask. Scanning electron microscope images indicate that the sidewall slope is steeper than four. (C) 1998 American Vacuum Society. [S0734-211X(98)13006-8]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gillaspy, JD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM John.Gillaspy@NIST.gov NR 32 TC 35 Z9 38 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1998 VL 16 IS 6 BP 3294 EP 3297 DI 10.1116/1.590367 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 148QA UT WOS:000077542300070 ER PT J AU Sunda, WG Huntsman, SA AF Sunda, WG Huntsman, SA TI Interactive effects of external manganese, the toxic metals copper and zinc, and light in controlling cellular manganese and growth in a coastal diatom SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SARGASSO-SEA; MARINE-PHYTOPLANKTON; OXYGEN EVOLUTION; NORTH PACIFIC; TRACE-METALS; IRON; SEAWATER; MN; THALASSIOSIRA; SPECIATION AB Manganese is a fundamental component of the photosystem II reaction center, and thus its requirement should be Linked to light utilization. High levels of Cu and Zn antagonize Mn nutrition by inhibiting cellular Mn uptake. Experiments were conducted to examine the interactive effects of Mn, the toxic metals Cu and Zn, and light on cellular Mn, chlorophyll a (Chl a), and specific growth rate in Thalassiosira pseudonana. Cu and Zn inhibition of growth rate occurred only at low Mn ion concentrations, an effect that was independent of Light intensity and was totally accounted for by inhibition of Mn uptake by these metals. Cells grown at growth-limiting low light intensities contained high levels of Mn and Chi a, which are needed for the synthesis of additional photosynthetic units during low-light acclimation. This additional Mn was not provided by higher cellular Mn uptake rates, since these rates were the same in light-saturated and light-limited cells. However, because steady-state cell Mn is equal to the uptake rate divided by the specific growth rate, the cells were able to accumulate the additional Mn needed for acclimation once light limitation caused growth rate to decline, a inherent negative feedback relation. In seawater, Mn and Cu may interact with light in controlling algal growth rate, since the free ion concentration of both metals is influenced by light within the euphotic zone. C1 NOAA, Beaufort Lab, Natl Marine Fisheries Serv, Beaufort, NC 28516 USA. RP Sunda, WG (reprint author), NOAA, Beaufort Lab, Natl Marine Fisheries Serv, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 35 TC 40 Z9 42 U1 1 U2 16 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1998 VL 43 IS 7 BP 1467 EP 1475 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 143YK UT WOS:000077285000007 ER PT J AU Wing, SR Botsford, LW Ralston, SV Largier, JL AF Wing, SR Botsford, LW Ralston, SV Largier, JL TI Meroplanktonic distribution and circulation in a coastal retention zone of the northern California upwelling system SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID OCEAN DYNAMICS EXPERIMENT; GENUS SEBASTES; WEST-COAST; SEA-URCHIN; TRANSPORT; RECRUITMENT; POPULATIONS; SHELF; JUVENILES; CURRENTS AB Previous studies have shown that settlement of several crab species along the coast north of Point Reyes (38 degrees 00'N, 123 degrees 00'W occurs primarily during relaxation from upwelling, when warm water flows poleward from the Gulf of the Farallones. During 1994 and 1995 we sampled planktonic larval distributions and hydrography both south and north of Point Reyes during upwelling to test whether high concentrations of crab and rockfish larvae were concentrated in the source of the relaxation flow to the south of Point Reyes. An upwelling plume off Point Reyes and an "upwelling shadow," indicated by warmer, less saline water in the northern Gulf, were evident in both years, as were frontal regions that marked the boundaries between water types of three different types: (1) newly upwelled, (2) oceanic, and (3) San Francisco Bay outflow. In addition, there was a fourth type, termed Gulf water, that was a mixture of these three types. Concentrations of larvae of cancrid, pinnotherid, and "coastal" crabs and rockfishes were high south of Point Reyes but were low or absent in the newly upwelled water north of the point. Within the upwelling shadow, these meroplankton taxa were associated with different water masses. Several intertidal crab species and early-stage cancrid crabs were concentrated in San Francisco Bay outflow water, and coastal Gulf water late-stage cancrid crabs, early- and late-stage pinnotherid crabs, and rockfishes were concentrated at the frontal region between newly upwelled and Gulf water. Of the taxa examined, only rockfishes were found offshore in oceanic water. The high concentrations of meroplankton observed suggest that the Gulf of the Farallones is an important retention area for larvae that settle into coastal populations in the Gulf and to the north via poleward transport during upwelling relaxation. C1 Univ Otago, Dept Marine Sci, Dunedin, New Zealand. Univ Calif Davis, Dept Wildlife Fish & Conservat Biol, Davis, CA 95616 USA. Natl Marine Fisheries Serv, Tiburon Lab, Tiburon, CA 94920 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Wing, SR (reprint author), Univ Otago, Dept Marine Sci, POB 56, Dunedin, New Zealand. NR 56 TC 135 Z9 137 U1 0 U2 7 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1998 VL 43 IS 7 BP 1710 EP 1721 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 143YK UT WOS:000077285000029 ER PT J AU Cambalik, JJ Checkley, DM Kamykowski, D AF Cambalik, JJ Checkley, DM Kamykowski, D TI A new method to measure the terminal velocity of small particles: A demonstration using ascending eggs of the Atlantic menhaden (Brevoortia tyrannus) SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID COD GADUS-MORHUA; ONE-DIMENSIONAL MODEL; VERTICAL-DISTRIBUTION; EMBRYONIC-DEVELOPMENT; GULF MENHADEN; PELAGIC FISH; WATER COLUMN; BUOYANCY; DENSITY AB A new method, incorporating video, motion analysis, and a novel experimental apparatus, was used to measure the terminal velocity of particles. The method facilitated the investigation of treatment effects and maximized the number of measurements for each replicate, thus improving the statistics for a population of particles. The eggs of the Atlantic menhaden (Brevoortia tyrannus) were used to demonstrate the method by investigating the effects of salinity and stage of development on their ascent rate. Egg ascent rate was greatest at intermediate salinity (36.5 parts per thousand) and decreased in the late stage of embryonic development. We estimate eggs at oceanic salinities (>35.5 parts per thousand) in nature to ascend at 0.19-0.25 cm s(-1). C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort Lab, Beaufort, NC 28516 USA. Univ Calif San Diego, Scripps Inst Oceanog, Marine Life Res Grp, La Jolla, CA 92093 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Cambalik, JJ (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Beaufort Lab, Beaufort, NC 28516 USA. NR 42 TC 8 Z9 10 U1 0 U2 0 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1998 VL 43 IS 7 BP 1722 EP 1727 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 143YK UT WOS:000077285000030 ER PT J AU Niroomand-Rad, A Blackwell, CR Coursey, BM Gall, KP Galvin, JM McLaughlin, WL Meigooni, AS Nath, R Rodgers, JE Soares, CG AF Niroomand-Rad, A Blackwell, CR Coursey, BM Gall, KP Galvin, JM McLaughlin, WL Meigooni, AS Nath, R Rodgers, JE Soares, CG TI Radiochromic film dosimetry: Recommendations of AAPM Radiation Therapy Committee Task Group 55 SO MEDICAL PHYSICS LA English DT Article DE radiochromic films; film dosimetry; film scanners ID SR-90+Y-90 OPHTHALMIC APPLICATORS; STEREOTAXIC RADIOSURGERY; DOSE DISTRIBUTIONS; ELECTRON-BEAMS; X-RAY; VERIFICATION; CALIBRATION; INTERFACES; CHLORIDE; PULSE AB Recommendations of the American Association of Physicists in Medicine (AAPM) for the radiochromic film dosimetry are presented. These guidelines were prepared by a task group of the AAPM Radiation Therapy Committee and have been reviewed and approved by the AAPM Science Council. (C) 1998 American Association of Physicists in Medicine. [S0094-2405(98)00211-9]. C1 Georgetown Univ, Med Ctr, Dept Radiat Med, Washington, DC 20007 USA. Mayo Clin, Rochester, MN USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Texas, SW Med Ctr, Dept Radiat Oncol, Dallas, TX USA. Thomas Jefferson Univ, Dept Radiat Oncol, Philadelphia, PA 19107 USA. Univ Kentucky, Dept Radiat Med, Lexington, KY USA. Yale Univ, Sch Med, Dept Therapeut Radiol, New Haven, CT USA. RP Niroomand-Rad, A (reprint author), Georgetown Univ, Med Ctr, Dept Radiat Med, Washington, DC 20007 USA. RI Grams, Michael/G-5197-2011 NR 90 TC 513 Z9 519 U1 3 U2 22 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD NOV PY 1998 VL 25 IS 11 BP 2093 EP 2115 DI 10.1118/1.598407 PG 23 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 139TD UT WOS:000077045000002 PM 9829234 ER PT J AU Gaffey, MJ Gilbert, SL AF Gaffey, MJ Gilbert, SL TI Asteroid 6 Hebe: The probable parent body of the H-type ordinary chondrites and the IIE iron meteorites SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID S-TYPE ASTEROIDS; ACHONDRITE METEORITES; PHYSICAL-PROPERTIES; SECULAR RESONANCE; OXYGEN ISOTOPE; DISCOVERY; EVOLUTION; ORIGIN; MELT; SPECTROSCOPY AB The S(IV)-type asteroid 6 Hebe is identified as the probable parent body of the H-type ordinary chondrites and of the LIE iron meteorites. The ordinary chondrites are the most common type of meteorites falling to Earth; but prior to the present study, no large mainbelt source bodies have been confirmed. Hebe is located adjacent to both the upsilon(6) and 3:1 resonances and has been previously suggested as a major potential source of the terrestrial meteorite flux. Hebe exhibits subtle rotational spectral variations, indicating the presence of some compositional variations across its surface. The silicate portion of the surface assemblage of Hebe is consistent (both in overall average and in its range of variation) with the silicate components in the suite of H-type chondrites. The high albedo of Hebe rules out a lunar-style space weathering process to produce the weakened absorption features and reddish spectral slope in the S-type spectrum of Hebe. Linear unmixing models show that a typical Ni-Fe metal spectrum is consistent with the component that modifies an H-chondrite spectrum to produce the S-type spectrum of Hebe. On the basis of the association between the H chondrites and the IIE iron meteorites, our model suggests that large impacts onto the relatively metal-rich H-chondrite target produced melt bodies (sheets or pods) that differentiated to form thin, laterally extensive near-surface layers of Ni-Fe metal. Fragments of the upper silicate portions of these melt bodies are apparently represented by some of the igneous inclusions in H-chondrite breccias. Alternately, masses of metal could have been deposited on the surface of Hebe by the impact of a core or core fragment from a differentiated parent body of H-chondrite composition. Subsequent impacts preferentially eroded and depleted the overlying silicate and regolith components, exposing and maintaining large masses of metal at the optical surface of Hebe. In this interpretation, the nonmagmatic IIE iron meteorites are samples of the Ni-Fe metal masses on the surface of Hebe, whereas the H chondrites are samples from between and/or beneath the metal masses. C1 Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY 12180 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Gaffey, MJ (reprint author), Rensselaer Polytech Inst, Dept Earth & Environm Sci, W Hall, Troy, NY 12180 USA. EM gaffem@rpi.edu NR 99 TC 92 Z9 93 U1 1 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 1998 VL 33 IS 6 BP 1281 EP 1295 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 147YY UT WOS:000077526400008 ER PT J AU Newbury, DE AF Newbury, DE TI Standardless quantitative electron-excited X-ray microanalysis by energy-dispersive spectrometry: What is its proper role? SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE electron beam X-ray microanalysis; electron probe microanalyzer; energy-dispersive spectrometry (EDS); quantitative X-ray microanalysis; scanning electron microscope; X-ray microanalysis AB Electron beam X-ray microanalysis with semiconductor energy-dispersive spectrometry (EDS) performed with standards and calculated matrix corrections can yield quantitative results with a distribution such that 95% of analyses fall within +/-5% relative for major and minor constituents. Standardless methods substitute calculations for the standard intensities, based either on physical models of X-ray generation and propagation (first principles) or on mathematical fits to remotely measured standards (fitted standards). Error distributions have been measured for three different standardless analysis procedures with a suite of microanalysis standards including metal alloys, glasses, minerals, ceramics, and stoichiometric compounds. For the first-principles standardless procedure, the error distribution placed 95% of analyses within +/-50% relative, whereas for two commercial fitted standards procedures, the error distributions placed 95% of analyses within +/-25% relative. The implication of these error distributions for the accuracy of analytical results is considered, and recommendations for the use of standardless analysis are given. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Newbury, DE (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Bldg 222,Room A113, Gaithersburg, MD 20899 USA. NR 13 TC 7 Z9 7 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD NOV-DEC PY 1998 VL 4 IS 6 BP 585 EP 597 DI 10.1017/S1431927698980564 PG 13 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 179RN UT WOS:000079342900006 ER PT J AU Spencer, PL Stensrud, DJ AF Spencer, PL Stensrud, DJ TI Simulating flash flood events: Importance of the subgrid representation of convection SO MONTHLY WEATHER REVIEW LA English DT Article ID LARGE-SCALE ENVIRONMENTS; NUMERICAL-SIMULATION; WEATHER SYSTEMS; MESOSCALE; MODEL; PARAMETERIZATION; PRECIPITATION; RESOLUTION; VERIFICATION; SENSITIVITY AB The Pennsylvania State University-NCAR Mesoscale Model is used to simulate six flash flood events that occurred in the central and eastern United States. Results suggest that standard model simulations of 24-h accumulated precipitation provide little indication of the potential for Rash flood-producing rainfall for most events. Often the model generates convective outflow boundaries that rapidly move away from their source region and initiate new convection well removed from the original convective activity. This self-sustaining propagation mechanism prevents long-lived heavy rainfall over a particular region. Three modifications to the Kain-Fritsch convective parameterization scheme, each designed to test model sensitivity to the convective scheme formulation, are discussed. The modifications include maximizing the convective scheme precipitation efficiency and altering the scheme's treatment of convective downdrafts. Model results using the three modifications of the convective scheme each show improvements in 24-h precipitation totals compared to simulations generated using the unmodified convective scheme, Precipitation totals appear to be especially sensitive to the way downdrafts are treated within the convective scheme. In addition, the impact of including the mesoscale details of a previously generated outflow boundary into the model initial conditions is demonstrated for one of the flash hood cases. It is shown that including the surface mesoscale details can have a substantial impact upon the magnitude and location of model precipitation maxima. C1 NOAA, Natl Severe Storms Lab, ERL, Norman, OK 73069 USA. RP Spencer, PL (reprint author), NOAA, Natl Severe Storms Lab, ERL, 1313 Halley Circle, Norman, OK 73069 USA. NR 42 TC 32 Z9 40 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1998 VL 126 IS 11 BP 2884 EP 2912 DI 10.1175/1520-0493(1998)126<2884:SFFEIO>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 137TP UT WOS:000076932600009 ER PT J AU Markowski, PM Rasmussen, EN Straka, JM Dowell, DC AF Markowski, PM Rasmussen, EN Straka, JM Dowell, DC TI Observations of low-level baroclinity generated by anvil shadows SO MONTHLY WEATHER REVIEW LA English DT Article ID SUPERCELL; ROTATION; THUNDERSTORMS; PROPAGATION; OKLAHOMA; MESONET; SYSTEM; STORMS AB Low-level cooling beneath the cirrus anvil canopies of supercell thunderstorms is documented in two Verification of the Origins of Rotation in Tornadoes Experiment cases and in the 17 May 1981 Arcadia, Oklahoma, supercell. Surface temperature decreases of 3 degrees C or more occurred beneath the anvils within 45 min of the onset of overcast conditions. Cooling was confined to the lowest few hundred meters of the boundary layer, and believed to be due mainly to a deficit in the energy budget following a reduction of incoming shortwave radiation. In the three cases studied, the vertical wind shear was strong; thus, mixing prevented the formation of an inversion layer Strong insolation at the ground outside of the anvil shadows coupled with the cooling beneath the cirrus canopies led to corridors of baroclinity along the shadow edges. It is shown that residence times in these baroclinic zones may be long enough for parcels to acquire considerable horizontal vorticity (e.g., similar to 10(-2) s(-1)) cn route to a storm updraft. Enhancement of the horizontal vorticity of parcels ingested by an updraft may have implications for the dynamics of storm rotation. C1 Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Cooperat Inst Mesoscale Meteorol Studies, Natl Severe Storms Lab, Boulder, CO USA. RP Markowski, PM (reprint author), Univ Oklahoma, Sch Meteorol, 100 E Boyd St,Room 1310, Norman, OK 73019 USA. RI Dowell, David/E-7855-2015; OI Markowski, Paul/0000-0002-4295-3390 NR 20 TC 29 Z9 29 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1998 VL 126 IS 11 BP 2942 EP 2958 DI 10.1175/1520-0493(1998)126<2942:OOLLBG>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 137TP UT WOS:000076932600012 ER PT J AU Markowski, PM Straka, JM Rasmussen, EN Blanchard, DO AF Markowski, PM Straka, JM Rasmussen, EN Blanchard, DO TI Variability of storm-relative helicity during VORTEX SO MONTHLY WEATHER REVIEW LA English DT Article ID SIMULATED CONVECTIVE STORMS; THUNDERSTORM; PROPAGATION; ENERGETICS; DRYLINE; MESONET; SHEAR AB In this paper, storm-relative helicity (SRH) and low-level vertical shear of the horizontal wind fields were investigated on the mesoscale and stormscale in regions where tornadoes occurred for four case studies using data collected during the Verification of the Origin of Rotation in Tornadoes Experiment. A primary finding was that SRH was highly variable in bath time and space in all of the cases, suggesting that this parameter might be difficult to use to predict which storms might become tornadic given the available National Weather Service upper-air wind data. Second, it was also found that the shear between the lowest mean 500-m wind and the 6-km wind was fairly uniform over vast regions in all of the four cases studied; thus, this parameter provided little guidance other than that there was possibly enough shear to support supercells. It was contended that forecasters will need to monitor low-level features, such as boundaries or wind accelerations, which might augment streamwise vorticity ingested into storms. Finally, it was suggested that one reason why one storm might produce a tornado while a nearby one does not might be due to the large variations in SRH on very small spatial and temporal scales. In other words, only those storms that move into regions, small or large, with sufficient SRH might produce tornadoes. C1 Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Cooperat Inst Mesoscale Meteorol Studies, Natl Severe Storms Lab, Boulder, CO USA. RP Markowski, PM (reprint author), Univ Oklahoma, Sch Meteorol, 100 E Boyd St,Room 1310, Norman, OK 73019 USA. OI Markowski, Paul/0000-0002-4295-3390 NR 38 TC 52 Z9 53 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1998 VL 126 IS 11 BP 2959 EP 2971 DI 10.1175/1520-0493(1998)126<2959:VOSRHD>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 137TP UT WOS:000076932600013 ER PT J AU Bernardet, LR Cotton, WR AF Bernardet, LR Cotton, WR TI Multiscale evolution of a derecho-producing mesoscale convective system SO MONTHLY WEATHER REVIEW LA English DT Article ID FRONTAL SURFACES; DOPPLER RADAR; POSITIVE CAPE; ENVIRONMENTS; COMPLEXES; PARAMETERIZATION; THUNDERSTORMS; DYNAMICS; GENESIS; MODELS AB In this paper the authors address one type of severe weather: strong straight-line winds. The case of a mesoscale convective system that developed in eastern Colorado on 12-13 May 1985 was studied. The system formed in the afternoon, was active until early morning, and caused strong winds during the night. A multiscale nonhydrostatic full physics simulation was performed to formulate a conceptual model of the main airflow branches of the system, and to gain understanding of the physical processes involved in the strong wind generation in this storm. Four telescopically nested grids covering from the synoptic-scale down to cloud-scale circulations were used. A Lagrangian model was employed to follow trajectories of parcels that took part in the updraft and downdraft, and balances of forces were computed along the trajectories. The,strong nocturnal winds were caused by downdrafts reaching the surface and by a dynamically forced horizontal pressure gradient force. The most important branch of the downdraft had an "up-down" trajectory. Parcels originated close to the ground, were lifted up by a strong upward-directed pressure gradient force, and became colder than their surroundings as they ascended in a stable environment. Then, as they went through the precipitation shaft, they sank due to negative buoyancy enhanced by condensate loading. The upward pressure gradient force was partially related to midlevel perturbation vorticity in the storm. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Bernardet, LR (reprint author), NOAA, ERL, 325 Broadway R-E-FS1, Boulder, CO 80303 USA. RI Bernardet, Ligia/N-3357-2014 NR 49 TC 27 Z9 30 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1998 VL 126 IS 11 BP 2991 EP 3015 DI 10.1175/1520-0493(1998)126<2991:MEOADP>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 137TP UT WOS:000076932600015 ER PT J AU Reichert, WL Myers, MS Peck-Miller, K French, B Anulacion, BF Collier, TK Stein, JE Varanasi, U AF Reichert, WL Myers, MS Peck-Miller, K French, B Anulacion, BF Collier, TK Stein, JE Varanasi, U TI Molecular epizootiology of genotoxic events in marine fish: Linking contaminant exposure, DNA damage, and tissue-level alterations SO MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH LA English DT Article DE DNA adduct; chemical carcinogenesis; hepatic lesion; bioindicator; fish; polycyclic aromatic compound; contaminant exposure ID SOLE PAROPHRYS-VETULUS; P-32 POSTLABELING ANALYSIS; ENGLISH SOLE; PUGET-SOUND; HEPATIC-LESIONS; P-32-POSTLABELING ANALYSIS; PLEURONECTES-VETULUS; TOXIC-CHEMICALS; WINTER FLOUNDER; RAINBOW-TROUT AB Molecular epizootiological studies are increasingly being used to investigate environmental effects of genotoxic contaminants. The assessment of damage to DNA and linking the damage to subsequent molecular, cellular, or tissue-level alterations is a central component of such studies. Our research has focused on the refinement of the P-32-postlabeling assay for measuring covalent DNA-xenobiotic adducts arising from exposure to polycyclic aromatic compounds, using DNA adducts as molecular dosimeters of genotoxic contaminant exposure in biomonitoring studies, and investigating the relationship of DNA adduct formation to toxicopathic liver disease, including neoplastic lesions. A combination of field and laboratory studies using the P-32-postlabeling assay has shown that DNA adducts in marine fish are effective molecular dosimeters of genotoxic contaminant exposure. Investigations of the relationship of DNA adduct formation to neoplastic liver disease have shown that elevated levels of DNA adducts in certain fish species from contaminated coastal sites are associated with increased prevalences of toxicopathic hepatic lesions, including neoplasms, and that the ability to assess DNA damage has helped to explain, in part, species differences in lesion prevalence. Moreover, in a study of a site in Puget Sound contaminated with polycyclic aromatic compounds, we have shown, for the first time, that elevated levels of hepatic DNA adducts are a significant risk factor for certain degenerative and preneoplastic lesions occurring early in the histogenesis of hepatic neoplasms in feral English sole (Pleuronectes vetulus). These latter findings coupled with our current studies of mutational events in the K-ras proto-oncogene should provide further mechanistic substantiation that mutagenic events resulting from exposure to complex mixtures of genotoxic polycyclic aromatic compounds are involved in the etiology of hepatic neoplasia in English sole. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Reichert, WL (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 40 TC 64 Z9 68 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-5742 J9 MUTAT RES-REV MUTAT JI Mutat. Res.-Rev. Mutat. Res. PD NOV PY 1998 VL 411 IS 3 BP 215 EP 225 DI 10.1016/S1383-5742(98)00014-3 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 138ZY UT WOS:000077004000002 PM 9804956 ER PT J AU Rockwell, GF Campfield, T Nelson, BC Uden, PC AF Rockwell, GF Campfield, T Nelson, BC Uden, PC TI Oxalogenesis in parenteral nutrition solution components SO NUTRITION LA English DT Article DE oxalate; ascorbate; total parenteral nutrition ID ASCORBIC-ACID; OXALATE EXCRETION; PRETERM INFANTS; NEPHROCALCINOSIS; STABILITY AB Oxalate has been implicated in the etiology of nephrocalcinosis in premature infants as well as in the formation of insoluble precipitates in total parenteral nutrition (TPN) intravenous tubing. Oxidation of ascorbate to oxalate, especially in the presence of catalysts such as copper and iron, has been implicated in formation of these precipitates. The purpose of this project was to measure oxalate formation in certain TPN components separately and in combination. Neonatal TPN solution components in combination were infused at 5 mL/h under simulated clinical conditions used in a neonatal intensive care unit. Aliquots were assayed at intervals for oxalate by capillary electrophoresis. Oxalate: is present in one TPN mixture at concentrations up to 8 ppm. The addition of ascorbate to an aqueous solution of trace metals may promote oxalogenesis. (C) Elsevier Science Inc. 1998. C1 Tufts Univ, Sch Med, Baystate Med Ctr, Dept Pediat, Springfield, MA 01199 USA. NIST, Gaithersburg, MD 20899 USA. Univ Massachusetts, Dept Chem, Amherst, MA 01003 USA. RP Rockwell, GF (reprint author), Wesson Womens Hosp, Baystate Med Ctr, Springfield, MA 01199 USA. EM Gary.Rockwell@BHS.org NR 26 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD NOV-DEC PY 1998 VL 14 IS 11-12 BP 836 EP 839 DI 10.1016/S0899-9007(98)00104-X PG 4 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 140RK UT WOS:000077102000002 PM 9834925 ER PT J AU Najafi, B Ghayeb, Y Rainwater, JC Alavi, S Snider, RF AF Najafi, B Ghayeb, Y Rainwater, JC Alavi, S Snider, RF TI Improved initial density dependence of the viscosity and a corresponding states function for high pressures SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE viscosity; high-pressure excess viscosity; second viscosity virial coefficient; Rainwater-Friend theory ID 11 POLYATOMIC GASES; TRANSPORT-PROPERTIES; NOBLE-GASES; THERMAL-CONDUCTIVITY; PHYSICAL-PROPERTIES; ORGANIC VAPORS; ARGON; EQUILIBRIUM; COEFFICIENTS; TEMPERATURE AB The initial density correction to gaseous viscosity using accurate realistic potentials of the noble gases is evaluated using the Rainwater-Friend theory. It is shown that this theory works satisfactorily for densities up to about 2 mol dm(-3). Due to the superimposability of the noble gas potential functions, a universal function of the reduced second viscosity virial coefficient is obtained over the entire reduced temperature range. At densities beyond the range of the theory, a variant of the excess viscosity is developed, by which the viscosity of the different gases can be easily calculated above the critical temperature for pressures up to 900 MPa. The accuracy of this method is within the experimental uncertainties. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada. Isfahan Univ Technol, Dept Chem, Esfahan 84154, Iran. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Snider, RF (reprint author), Univ British Columbia, Dept Chem, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada. EM snider@theory.chem.ubc.ca NR 50 TC 31 Z9 31 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD NOV 1 PY 1998 VL 260 IS 1-2 BP 31 EP 48 DI 10.1016/S0378-4371(98)00287-8 PG 18 WC Physics, Multidisciplinary SC Physics GA 135WL UT WOS:000076825600004 ER PT J AU Doery, MR Vredenbregt, EJD de Beek, SSO Beijerinck, HCW Verhaar, BJ AF Doery, MR Vredenbregt, EJD de Beek, SSO Beijerinck, HCW Verhaar, BJ TI Limit on suppression of ionization in metastable neon traps due to long-range anisotropy SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; POLARIZED TRIPLET HELIUM; ELECTRONIC STATES; ATOMS; GAS; DISPERSION; BEAM; NA-2; KR AB This paper investigates the possibility of suppressing the ionization rate in a magnetostatic trap of metastable neon atoms by spin-polarizing the atoms. Suppression of the ionization is critical for the possibility of reaching Bose-Einstein condensation with such atoms. We estimate the relevant long-range interactions for the system, consisting of electric quadrupole-quadrupole and dipole-induced dipole terms, and develop short-range potentials based on the Na-2 singlet and triplet potentials. The autoionization widths of the system are also calculated. With these ingredients we calculate the ionization rate for spin-polarized and for spin-isotropic samples, caused by anisotropy of the long-range interactions. We find that spin polarization may allow for four orders of magnitude suppression of the ionization rate for Ne. The results depend sensitively on a precise knowledge of the interaction potentials, however, pointing out the need for experimental input. The-same model gives a suppression ratio close to unity for metastable xenon in accordance with experimental results, due to a much increased anisotropy in this case. [S1050-2947(98)03111-4]. C1 Eindhoven Univ Technol, Dept Phys, NL-5600 MB Eindhoven, Netherlands. RP Doery, MR (reprint author), Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 41 TC 21 Z9 21 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1998 VL 58 IS 5 BP 3673 EP 3682 DI 10.1103/PhysRevA.58.3673 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 138FT UT WOS:000076961300044 ER PT J AU Suominen, KA Tiesinga, E Julienne, PS AF Suominen, KA Tiesinga, E Julienne, PS TI Nonadiabatic dynamics in evaporative cooling of trapped atoms by a radio-frequency field SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; SPIN-POLARIZED HYDROGEN; WAVE-PACKET DYNAMICS; COLLECTIVE EXCITATIONS; RELAXATION RATES; MAGNETIC TRAP; COLLISIONS; TIME; GAS AB Magnetically trapped neutral atoms can be cooled with the evaporation technique. This is typically done by using a radio-frequency (rf) field that adiabatically couples trapped and untrapped internal atomic states for atoms with kinetic energies above a value set by the field frequency. The rf field can also induce nonadiabatic changes of internal atomic spin states (F,M) that lead to heating and enhanced loss of atoms. In this paper we use wave-packet simulations to show that the evaporation process can induce these nonadiabatic transitions, which change the internal spin state of doubly spin-polarized (2,2) trapped atoms. We also verify the validity of a multistate Landau-Zener model in describing the nonadiabatic dynamics. In addition, we calculate exchange relaxation rate coefficients for collisions between atoms in the (2,M) states of Na-23 atoms. Large exchange relaxation coefficients for Na-23 as compared to Rb-87 F=2 suggest that evaporative cooling of (2,2) Na will be more difficult than for the corresponding state of Rb. [S1050-2947(98)07811-1]. C1 Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Univ Helsinki, Dept Phys, Div Theoret Phys, FIN-00014 Helsinki, Finland. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Suominen, KA (reprint author), Helsinki Inst Phys, PL 9, FIN-00014 Helsinki, Finland. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 42 TC 16 Z9 16 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1998 VL 58 IS 5 BP 3983 EP 3992 DI 10.1103/PhysRevA.58.3983 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 138FT UT WOS:000076961300076 ER PT J AU Cross, JO Newville, M Rehr, JJ Sorensen, LB Bouldin, CE Watson, G Gouder, T Lander, GH Bell, MI AF Cross, JO Newville, M Rehr, JJ Sorensen, LB Bouldin, CE Watson, G Gouder, T Lander, GH Bell, MI TI Inclusion of local structure effects in theoretical x-ray resonant scattering amplitudes using ab initio x-ray-absorption spectra calculations SO PHYSICAL REVIEW B LA English DT Article ID ANOMALOUS FINE-STRUCTURE; SYNCHROTRON RADIATION; POLARIZED DISPERSION; PHASE DETERMINATION; DIFFRACTION; REFLECTION; UO2 AB Improved calculations of Bragg peak intensities near atomic resonance are obtained by including the effect of the local environment around the resonant atoms on the resonant scattering amplitudes Delta f=f'+if" Theoretical absorption cross sections calculated by the ab initio x-ray-absorption code FEFF are used to obtain the imaginary part f" by extension of the optical theorem to nonforward scattering under the dipole approximation. The real part f' is obtained by a limited range Kramers-Kronig transform of the difference between f" based on FEFF and existing theoretical calculations of f" based on an isolated-atom model. The atomic part of Delta f calculated by FEFF for the resonant atom embedded in the local potential is assumed to have spherical symmetry; however, no restriction is placed on the spectral features due to multiple scattering of the intermediate-state virtual photoelectron. Bragg peak intensities calculated in the kinematic approximation using the FEFF-based Delta f are compared to intensities calculated using the isolated-atom Delta f and to experimental data for Cu metal and YBa2Cu3O6.8 at the Cu K absorption edge,and for UO2 at the U M-IV absorption edge. [S0163-1829(98)06541-2]. C1 Naval Res Lab, Washington, DC 20375 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Washington, Seattle, WA 98195 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA. Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. RP Cross, JO (reprint author), Naval Res Lab, Washington, DC 20375 USA. EM jox@pnc.aps.anl.gov NR 45 TC 85 Z9 85 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 1998 VL 58 IS 17 BP 11215 EP 11225 DI 10.1103/PhysRevB.58.11215 PG 11 WC Physics, Condensed Matter SC Physics GA 133ZD UT WOS:000076716700036 ER PT J AU Barilo, SN Shiryaev, SV Gatalskaya, VI Lynn, JW Baran, M Szymczak, H Szymczak, R Dew-Hughes, D AF Barilo, SN Shiryaev, SV Gatalskaya, VI Lynn, JW Baran, M Szymczak, H Szymczak, R Dew-Hughes, D TI Scaling of magnetization and some basic parameters of Ba1-xKxBiO3+y superconductors near T-c SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-PHONON INTERACTION; STRUCTURAL PHASE-DIAGRAM; FIELD PENETRATION DEPTH; SINGLE-CRYSTALS; THIN-FILMS; II SUPERCONDUCTORS; ENERGY-GAP; BA0.6K0.4BIO3; DEPENDENCE; YBA2CU3O7 AB Reversible magnetization and hysteresis loops have been studied over wide ranges of magnetic field and temperature for single crystals of Ba1-xKxBiO3+y (x=0.34, 0.37, 0.41, and 0.46). The main goals were to derive critical parameters of superconductors with a cubic structure as well as to explain the origin of flux pinning and peak (fishtail) effect observed in all samples. Values of the electron-phonon interaction constant of lambda(ph)similar to 1, similar to 0.76, and 0.9 for Ba1-xKxBiO3+y with x=0.34, x=0.37, and x=0.41, respectively, have been obtained. The data show that this family belongs to oxide superconductors with at least an intermediate strength of coupling. The pinning force density has been scaled into a single curve for wide field and temperature ranges. The functional form of the scaling curve reflects various mechanisms of flux pinning. For Ba0.54K0.46BiO3+y the peak effect is mainly due to a dynamical contribution. However, the fishtail for Ba1-xKxBiO3+y with x = 0.34, 0.37, and 0.41 has its origin in the crossover between two pinning mechanisms induced by external magnetic field and/or temperature. For the Ba0.59K0.41BiO3+y crystal a seeded growth-induced anisotropy was found to be responsible for differences in low-field susceptibility and in hysteresis loops observed for different magnetic-field orientations. [S0163-1829(98)00442-1]. C1 Byelarussian Acad Sci, Inst Phys Solids & Semicond, Minsk 220072, Byelarus. Univ Maryland, Ctr Supercond Res, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Univ Oxford, Dept Engn Sci, Oxford OX1 3PJ, England. RP Byelarussian Acad Sci, Inst Phys Solids & Semicond, Minsk 220072, Byelarus. NR 68 TC 15 Z9 15 U1 3 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1998 VL 58 IS 18 BP 12355 EP 12367 DI 10.1103/PhysRevB.58.12355 PG 13 WC Physics, Condensed Matter SC Physics GA 141PV UT WOS:000077153400079 ER PT J AU Martys, NS Shan, XW Chen, HD AF Martys, NS Shan, XW Chen, HD TI Evaluation of the external force term in the discrete Boltzmann equation SO PHYSICAL REVIEW E LA English DT Article AB A representation of the forcing term in the Boltzmann equation based on a Hermite expansion of the Boltzmann distribution function in velocity phase space is derived. Based on this description of the forcing term, a systematic comparison of previous lattice Boltzmann models describing a nonideal gas behavior is given. [S1063-651X(98)12010-X]. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, Theoret Div MS B213, Complex Syst Grp, Los Alamos, NM 87545 USA. Exa Corp, Cambridge, MA 02140 USA. RP Martys, NS (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 6 TC 91 Z9 92 U1 3 U2 23 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 1998 VL 58 IS 5 BP 6855 EP 6857 DI 10.1103/PhysRevE.58.6855 PN B PG 3 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 139VV UT WOS:000077052300099 ER PT J AU Yuan, D Elvidge, C AF Yuan, D Elvidge, C TI NALC land cover change detection pilot study: Washington DC area experiments SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID RELATIVE RADIOMETRIC NORMALIZATION; REMOTELY-SENSED DATA; MSS AB As a part of North American Landscape Characterization (NALC) project, 75 change-detection techniques and variations were systematically tested and evaluated using both visual and statistical methods. These change-detection experiments were conducted in the Washington, D.C. region using a standard NALC Landsat Multispectral Scanner (MSS) data set. While more testing of the NALC data is needed in geographically diversified regions, our initial results suggest that the automated scatter-gram controlled regression normalized image differencing and normalized difference vegetation index differencing outperform most other change-detection techniques. These techniques are worthy of further testing and of large-scale applications for NALC data. (C) Elsevier Science Inc., 1998. C1 Resource 21, Englewood, CO USA. NOAA, Natl Geophys Data Ctr, Solar Terr Phys Div, Boulder, CO 80303 USA. RP Yuan, D (reprint author), Resource 21, 7257 S Tucson Way, Englewood, CO USA. EM dyuan@resource21.com RI Elvidge, Christopher/C-3012-2009 NR 22 TC 68 Z9 80 U1 0 U2 4 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 NOV PY 1998 VL 66 IS 2 BP 166 EP 178 DI 10.1016/S0034-4257(98)00068-6 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 132FG UT WOS:000076619200006 ER PT J AU Snyder, CR Mopsik, FI AF Snyder, CR Mopsik, FI TI A precision capacitance cell for measurement of thin film out-of-plane expansion. I. Thermal expansion SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID POLYMER-FILMS AB A high sensitivity technique based on a three-terminal parallel plate capacitor for the measurement of the out-of-plane expansion of thin films is presented. The necessary assembly protocols and data reduction techniques for the proper use of this capacitance cell are presented. To demonstrate the ability of the technique to produce correct results for the thermal expansion of materials, the results on [0001] single crystal Al2O3 are shown and compared to the literature. Also, results for a thin polymeric film designed for use as an interlayer dielectric are shown to display the utility of the technique to resolve the measurement of displacement in thin films. [S0034-6748(98)03011-1]. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Snyder, CR (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Snyder, Chad/B-4957-2008 OI Snyder, Chad/0000-0002-2916-9809 NR 17 TC 12 Z9 12 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 1998 VL 69 IS 11 BP 3889 EP 3895 DI 10.1063/1.1149195 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 135GZ UT WOS:000076794600028 ER PT J AU Morillo, J Su, QM Panchapakesan, B Wuttig, M Novotny, D AF Morillo, J Su, QM Panchapakesan, B Wuttig, M Novotny, D TI Micromachined silicon torsional resonator for magnetic anisotropy measurement SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A novel method for measuring the out-of-plane magnetic anisotropy of thin films has been developed using the existing techniques of silicon micromachining. The torsion pendulum, which is commonly used to measure the perpendicular magnetic anisotropy energy constant, K-u, is modified into a single crystal silicon high Q torsional resonator. This article describes the principle of a silicon torsional resonator, the experimental procedure for measuring magnetic anisotropy, and the results. The theoretical values of K-u for Terfenol-D and Metglas(R) thin films were compared to the experimentally determined values and found to be within the error limits which for Metglas(C), better than 1%. The agreement is poorer, 5%-15%, for amorphous stressed Terfenol- D, since its magneto-elastic energy is less accurately known. The results show that this is a viable method for measuring the magnetic anisotropy. (C) 1998 American Institute of Physics. [S0034-6748(98)04611-5]. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Morillo, J (reprint author), IBM Corp, Burlington, VT USA. EM donald.novotny@nist.gov NR 5 TC 12 Z9 12 U1 0 U2 5 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 1998 VL 69 IS 11 BP 3908 EP 3912 DI 10.1063/1.1149198 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 135GZ UT WOS:000076794600031 ER PT J AU Conny, JM Powell, CJ Currie, LA AF Conny, JM Powell, CJ Currie, LA TI Standard test data for estimating peak-parameter errors in x-ray photoelectron spectroscopy. I. Peak binding energies SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE XPS; reference data; x-ray photoelectron spectroscopy; peak fitting ID RANDOM UNCERTAINTIES; DATA SETS; XPS; AES AB Standard test data (STD) are simulations of analytical instrument responses that help to determine the veracity of computer-based, data analysis procedures that are typically used with instruments. The STD were developed for determining errors in peak parameters obtained from data analysis algorithms used in x-ray photoelectron spectroscopy (XPS). The STD were mainly C 1s doublet spectra constructed from spline polynomial models of measured C 1s polymer spectra. Different spectra were created based on a replicated factorial design with three factors: peak separation; relative intensity of the component peaks; and fractional Poisson noise. These doublet spectra simulated XPS measurements made on different two-component specimens. Single-peak C 1s spectra for individual polymers were also simulated, to provide the null case for identification of the doublet spectra. Twenty analysts used a variety of data analysis programs and a variety of curve-fitting approaches to determine peak binding energies. Results indicate that data analysis of doublet spectra may be problematic, because up to 50% of the STD doublets were assigned incorrectly as singlets. For spectra that were correctly identified as doublets, bias and random error in peak binding energies depended on the amount of separation between the component peaks and on their relative intensities. Biases ranged from -0.055 eV to 0.34 eV, while random errors ranged from 0.012 eV to 0.13 eV. Use of the Gaussian-Lorentzian function fitted to spectra resulted in smaller biases than the use of a Gaussian function alone. As a guide to evaluating peak energy uncertainties in their own analyses, analysts may find it useful to analyze the STD themselves and then compare their results with those reported here. The spectra may be obtained at http://www.acg.nist.gov/std/main.html. (C) 1998 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Conny, JM (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 22 TC 25 Z9 25 U1 1 U2 10 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD NOV PY 1998 VL 26 IS 12 BP 939 EP 956 DI 10.1002/(SICI)1096-9918(199811)26:12<939::AID-SIA441>3.0.CO;2-V PG 18 WC Chemistry, Physical SC Chemistry GA 142PD UT WOS:000077208300010 ER PT J AU Bakwin, PS Tans, PP Hurst, DF Zhao, CL AF Bakwin, PS Tans, PP Hurst, DF Zhao, CL TI Measurements of carbon dioxide on very tall towers: results of the NOAA/CMDL program SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODEL; ATMOSPHERIC CO2; ISOTOPIC COMPOSITION; NORTHERN-HEMISPHERE; MIXING RATIOS; MONOXIDE; EXCHANGE; FOREST; SIMULATIONS; METABOLISM AB Measurements of carbon dioxide (CO2) mixing ratios have been carried out since 1992 on a 610-m tall communications tower in North Carolina and since 1994 on a 447-m tall tower in Wisconsin. The data provide insights into the influence of pollution (fossil fuel combustion), biological exchange, boundary layer dynamics, and advective transport on CO2 mixing ratios over the continents. In this paper, we provide an overview of the data, describe access to the data, and suggest ways in which these results could be used to improve simulations of the global carbon cycle. In particular, the data will be very useful to constrain model estimates of covariance between terrestrial ecosystem fluxes of CO2 and diurnal and seasonal variations of planetary boundary layer mixing. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Bakwin, PS (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 47 TC 165 Z9 166 U1 2 U2 16 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 1998 VL 50 IS 5 BP 401 EP 415 DI 10.1034/j.1600-0889.1998.t01-4-00001.x PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 163TJ UT WOS:000078421400001 ER PT J AU Parker, RO Dixon, RL AF Parker, RO Dixon, RL TI Changes in a North Carolina reef fish community after 15 years of intense fishing - Global warming implications SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID CORAL; GROUPERS; SHELF; SOUTH AB A North Carolina reef fish community was resurveyed with scuba gear to determine if changes occurred in community structure after 15 years of intense fishing. Generally, fishes important in the recreational and commercial fisheries were smaller. and large changes occurred in relative abundance and species composition. Indicative of a warming trend, total species corn position of fishes had become more tropical, and a tropical sponge previously unrecorded at this latitude off the North Carolina coast became common. Two new (to the area) families and 29 new species of tropical fishes were recorded. Observations of 28 species of tropical reef fishes increased significantly. No new temperate species were observed, and the most abundant temperate species decreased by a factor of 22. Mean monthly bottom water temperatures in winter were 1-6 degrees C warmer during the recent study. An increase in fish-cleaning symbiosis was especially noticeable. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. RP Parker, RO (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Ctr, Beaufort Lab, Beaufort, NC 28516 USA. EM pparker@hatteras.bea.nmfs.gov NR 41 TC 45 Z9 46 U1 0 U2 14 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 1998 VL 127 IS 6 BP 908 EP 920 DI 10.1577/1548-8659(1998)127<0908:CIANCR>2.0.CO;2 PG 13 WC Fisheries SC Fisheries GA 169BX UT WOS:000078728600004 ER PT J AU Laszlo, B Alfassi, ZB Neta, P Huie, RE AF Laszlo, B Alfassi, ZB Neta, P Huie, RE TI Kinetics and mechanism of the reaction of (NH2)-N-center dot with O-2 in aqueous solutions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PULSE-RADIOLYSIS; LASER PHOTOLYSIS; RADICALS; AMMONIA; DECAY; NH2; NITRITE; ACID AB The reaction of NH3 With (OH)-O-. or SO4.- radicals produces the aminyl radical, (NH2)-N-.. Pulse radiolysis and laser flash photolysis techniques were utilized to study the formation of this radical, its absorption spectrum, its reaction with O-2, and the mechanism of formation of subsequent intermediates and the main final product, peroxynitrite. The rates of formation of (NH2)-N-. and its absorption spectrum are in agreement with previous reports. The reaction of (NH2)-N-. with O-2, however, was observed to take place much more rapidly than reported before and to involve an equilibrium of these reactants with the aminylperoxyl radical, NH2O2.. The equilibrium is shifted toward completion of the reaction via catalyzed decomposition of this peroxyl radical, and this decomposition affects the observed rate of reaction of (NH2)-N-. with O-2. The peroxyl radical deprotonates and isomerizes and finally forms NO. In the presence of O-2(.-), NO is converted rapidly to peroxynitrite, ONO2-. This product, which is stable at alkaline pH, was confirmed by gamma-radiolysis of aerated ammonia solutions. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Huie, RE (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Huie, Robert/A-5645-2010 NR 34 TC 14 Z9 14 U1 0 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 29 PY 1998 VL 102 IS 44 BP 8498 EP 8504 DI 10.1021/jp981529+ PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 136VH UT WOS:000076879500008 ER PT J AU Goldfarb, L Harwood, MH Burkholder, JB Ravishankara, AR AF Goldfarb, L Harwood, MH Burkholder, JB Ravishankara, AR TI Reaction of O(P-3) with ClONO2: Rate coefficients and yield of NO3 product SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID RESONANCE FLUORESCENCE MEASUREMENTS; ABSORPTION CROSS-SECTIONS; QUANTUM YIELDS; TEMPERATURE-DEPENDENCE; PHOTODISSOCIATION; PHOTOLYSIS; SPECTRUM; OH AB The rate coefficient for the reaction O(P-3) with ClONO2, k(1), was measured between 202 and 325 K using two methods: pulsed laser photolysis with time-resolved atomic resonance fluorescence detection of the O atoms and pulsed laser photolysis with long-path tunable diode laser absorption for detection of NO3 radicals. The measured rate coefficient. is summarized by k(1) = (4.5 +/- 1.4) x 10(-12) exp[(-900 +/- 80)/T]cm(3) molecule(-1) s(-1), with k(I)(298 K) = (2.2 +/- 0.2) x 10(-13) cm(3) molecule(-1) s(-1). The yield of NO, radical in this reaction was measured to be essentially unity. Our results are compared with those from previous studies. C1 NOAA, R E AL2, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ravishankara, AR (reprint author), NOAA, R E AL2, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 NR 25 TC 10 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 OCT 29 PY 1998 VL 102 IS 44 BP 8556 EP 8563 DI 10.1021/jp9819386 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 136VH UT WOS:000076879500016 ER PT J AU Golden, DM Smith, GP McEwen, AB Yu, CL Eiteneer, B Frenklach, M Vaghjiani, GL Ravishankara, AR Tully, FP AF Golden, DM Smith, GP McEwen, AB Yu, CL Eiteneer, B Frenklach, M Vaghjiani, GL Ravishankara, AR Tully, FP TI OH(OD)+CO: Measurements and an optimized RRKM fit SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID OH + CO; SHOCK-TUBE; TEMPERATURE-DEPENDENCE; RATE COEFFICIENT; PRESSURE-DEPENDENCE; CHEMICAL-KINETICS; RATE-CONSTANT; OD RADICALS; COMBUSTION; ABSORPTION AB Measurements were made for the rate constant of OH + CO + He at 293 K, and OD + CO + M (M = He, Ar, N-2, air, SF6) at 253-343 K. Results were also obtained for OH + CO in a shock tube at 1400-2600 K using OH and CO absorption. A two-channel RRKM model of these and other representative results was constructed, with five adjustable parameters. A systematic optimization method was then employed to produce the best fit of the data and provide predictive k(T,P,D/H) expressions for other conditions. C1 SRI Int, Menlo Park, CA 94025 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NOAA, Boulder, CO 80309 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Golden, DM (reprint author), SRI Int, 333 Ravenswood Ave, Menlo Park, CA 94025 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 39 TC 93 Z9 93 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 OCT 29 PY 1998 VL 102 IS 44 BP 8598 EP 8606 DI 10.1021/jp982110m PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 136VH UT WOS:000076879500021 ER PT J AU Lagalante, AF Clarke, AM Bruno, TJ AF Lagalante, AF Clarke, AM Bruno, TJ TI Modeling the water-R134a partition coefficients of organic solutes using a linear solvation energy relationship SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SUPERCRITICAL CARBON-DIOXIDE; SOLUBILITY MEASUREMENTS; WATER; SOLVENT; PREDICTION; OCTANOL; FLUIDS; CHROMATOGRAPHY; REFRIGERANTS; PARAMETER AB The water-R134a partition coefficients for a set of 11 organic solutes have been measured using a high-pressure, spectroscopic technique. Water partition coefficients of the organic solutes were measured in the gas and supercritical phases of R134a. A linear solvation energy relationship (LSER) was developed to predict the measured water-R134a partition coefficients using the Kamlet-Taft descriptors of the solute and solvent molecules as independent variables. Considering the entire water-R134a partition coefficient data, the LSER model has an average absolute relative deviation of 30%. Only considering the data above the critical density of R134a, the LSER has an average absolute relative deviation of 17.5%. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div 838 01, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div 838 01, 325 Broadway, Boulder, CO 80303 USA. NR 23 TC 13 Z9 13 U1 1 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 OCT 29 PY 1998 VL 102 IS 44 BP 8889 EP 8892 DI 10.1021/jp9827431 PG 4 WC Chemistry, Physical SC Chemistry GA 136VJ UT WOS:000076879600033 ER PT J AU Waksman, R Chan, RC Kim, WH Vodovotz, Y Karam, LR Zimmerman, BE Coursey, B Siglinger, M Marvaez, M AF Waksman, R Chan, RC Kim, WH Vodovotz, Y Karam, LR Zimmerman, BE Coursey, B Siglinger, M Marvaez, M TI Injection of radionuclides to the coronary arterial wall: "Hot arteries" - a novel vascular brachytherapy approach to reduce restenosis. SO CIRCULATION LA English DT Meeting Abstract C1 Washington Hosp Ctr, Washington, DC 20010 USA. NIST, Gaithersburg, MD 20899 USA. Intervent Technol, San Diego, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 27 PY 1998 VL 98 IS 17 SU S MA 3425 BP 652 EP 652 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 131UV UT WOS:000076594403442 ER PT J AU Angell, JK AF Angell, JK TI Contraction of the 300 mbar north circumpolar vortex during 1963-1997 and its movement into the eastern hemisphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TEMPERATURE; JANUARY AB The size of the 300 mbar north circumpolar vortex, and its partition into western and eastern hemispheres and quadrants 0 degrees 90 degrees W, 90 degrees W-180 degrees, 90 degrees E-180 degrees, and 0 degrees-90 degrees E, is estimated by planimetering the area poleward of contours in the main belt of westerlies on the polar stereographic mean-monthly analyses of the Institute of Meteorology of the Free University of Berlin. During 1963-1997 the trend in annual vortex size is a significant -1.4%/decade (vortex contraction), but with the trend in the western hemisphere portion of the vortex a significant -2.1%/decade compared to -0.7%/ decade in the eastern hemisphere portion, signifying a movement of the vortex farther into the eastern hemisphere. Thus, while on average 52% of the vortex was in the eastern hemisphere during 1963-1997, this value increased by a significant 0.4%/decade during the period, resulting in a substantial increase in vortex eccentricity. In winter and spring the vortex has moved mainly into the Asian quadrant 90 degrees E-180 degrees, whereas in summer the vortex has become elliptical with less of a decrease in size of quadrants 90 degrees E-180 degrees and 0 degrees-90 degrees W, and in autumn there has been a decrease in size of quadrant 90 degrees W-180 degrees relative to the other quadrants. The standard deviation of the annual quadrant-size anomalies has decreased significantly during 1963-1997, indicating a decrease in the annual displacements of the vortex center from its mean location as the eccentricity increases and the vortex contracts. On the basis of a 41-station northern hemisphere radiosonde network, during 1963-1997 the annual 850-300 mbar temperature increased by a significant 0.12 degrees C/decade in the northern hemisphere as a whole, and by a significant 0.17 degrees C/decade in the western half and by 0.06 degrees C/decade in the eastern half of the hemisphere. The resulting association of a 1%/decade decrease in 300 mbar vortex size, with about an 0.1 degrees C/decade increase in 850-300 mbar temperature, differs by a factor of 2 from what would be expected hydrostatically, a difference that would be eliminated by an 0.4 mbar/decade increase in midlatitude surface pressure during 1963-1997. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP NOAA, Air Resources Lab, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 18 TC 15 Z9 21 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 1998 VL 103 IS D20 BP 25887 EP 25893 DI 10.1029/98JD02451 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132BH UT WOS:000076609600002 ER PT J AU Hartten, LM Gutzler, DS AF Hartten, LM Gutzler, DS TI Estimates of large-scale divergence in the lower troposphere over the western equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OUTGOING LONGWAVE RADIATION; TROPICAL CLOUD CLUSTERS; TOGA-COARE; WARM POOL; DIURNAL CYCLE; SIMPLE-MODEL; WINDS; VARIABILITY; CIRCULATION; CONVERGENCE AB A network of 915-MHz wind profilers measured half-hourly lower-tropospheric winds over the western equatorial Pacific with vertical resolutions as high as 100 m during November 1992 through February 1993, the intensive observing period (IOP) of the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE). These wind data are used in conjunction with collocated surface wind measurements to examine the near-surface divergent flow over the western Pacific warm pool during austral summer as well as the synoptic-scale variability of divergence in both time and space. The synoptic-scale wind field estimated from profiler data exhibits stronger near-surface divergence than sonde-based estimates from the same time period. Temporal variations of the lower-tropospheric divergence profiles are described by three vertical structure functions derived from Varimax-rotated eigenvector analysis. One vertical mode appears to be associated with deep convection, one with near-surface processes, and one with shallower convection. These structure functions vary zonally across the COARE region, with the convective modes having convergence maxima at lower elevations to the west of the intensive flux array (IFA) than over and east of it. C1 NOAA, Cooperat Inst Res Environm Sci, Aeron Lab, Boulder, CO USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87106 USA. RP Univ Colorado, CIRES, Campus Box 216, Boulder, CO 80309 USA. EM lhartten@al.noaa.gov; gutzler@unm.edu RI Hartten, Leslie/F-1970-2010 OI Hartten, Leslie/0000-0002-5620-6302 NR 41 TC 1 Z9 1 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1998 VL 103 IS D20 BP 25895 EP 25904 DI 10.1029/98JD02171 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132BH UT WOS:000076609600003 ER PT J AU Sandor, BJ Read, WG Waters, JW Rosenlof, KH AF Sandor, BJ Read, WG Waters, JW Rosenlof, KH TI Seasonal behavior of tropical to midlatitude upper tropospheric water vapor from UARS MLS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MICROWAVE LIMB SOUNDER; RELATIVE-HUMIDITY; STRATOSPHERE; CLIMATE; ATMOSPHERE; GREENHOUSE; TRANSPORT AB Measurements of upper tropospheric water vapor made during 1991-1997 with the Microwave Limb Sounder instrument on the Upper Atmospheric Research Satellite are described. Zonal mean results versus day of year are presented for tropical to midlatitudes on pressure surfaces 316, 215, and 147 hPa. The latitude of greatest upper tropospheric humidity (UTH) varies with season, following the Intertropical Convergence Zone. Annual maximum UTH occurs in northern summer at north tropical latitudes, coincident with the Indian monsoon ana with a June-August maximum of water vapor transport to the lower stratosphere [Rosenlof et al., 1997]. Comparison with lower stratospheric studies supports the Rosenlof et al. [1997] conclusion that water vapor transport is a maximum from the summer northern hemisphere tropical troposphere. Seasonally adjusted UTH is higher in the northern hemisphere than at equivalent southern hemisphere latitudes. The midlatitude secondary maximum in relative humidity seen in other (lower altitude) data sets is' seen on the 316 hPa surface throughout the year, only in northern hemisphere spring-summer at 215 hPa, and does not occur at 147 hPa. These observations characterize seasonal and interhemispheric differences in strengths of midlatitude convection and of subtropical subsidence. Frequency distribution analysis of tropical measurements shows the peak (mode) of the frequency distribution to be much drier than mean and median values at 316 and 215 hPa and marginally drier than mean and median values at 147 hPa. The frequency distribution mode is drier in the tropical wet than in the dry season at 316 hPa, consistent with other data sets at 300-500 hPa [Spencer and Braswell, 1997; Chiou et al., 1997] but is wetter in the tropical wet than in the dry season at 215 and 147 hPa. The wettest values of the frequency distribution mode occur in April-May, corresponding to neither the tropical wet nor the dry season. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Aeron Lab, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. RP Natl Ctr Atmospher Res, Div Atmospher Chem, Pob 3000, Boulder, CO 80307 USA. EM sandor@acd.ucar.edu RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 30 TC 27 Z9 27 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1998 VL 103 IS D20 BP 25935 EP 25947 DI 10.1029/98JD02272 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132BH UT WOS:000076609600006 ER PT J AU Peterson, TC Karl, TR Jamason, PF Knight, R Easterling, DR AF Peterson, TC Karl, TR Jamason, PF Knight, R Easterling, DR TI First difference method: Maximizing station density for the calculation of long-term global temperature change SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SURFACE TEMPERATURES; TRENDS; UPDATE; MODEL AB The calculation of global land surface air temperature trends using the instrumental record has been based primarily upon two methods of maximizing the availability of station records. Hansen and Lebedeff [1987] developed a technique that is still used today, known as the reference station method; Jones ed al. [1986a] popularized the climate anomaly method in their calculations of global temperature trends. In this paper we introduce yet another approach designed to maximize station records, referred to as the first difference method. To test the sensitivity of global temperature trend analysis to the method used, we calculate worldwide-averaged land surface mean temperature using each of these methods with an identical data base, the Global Historical Climatology Network. For further comparisons a global climate model (GCM) transient model simulation is interpolated to the Global Historical Climatology Network station locations and the three techniques are then applied to data interpolated to the station locations from the model. The Intergovernmental Panel on Climate Change (IPCC); [Nicholls et al., 1996] estimated a global land and ocean temperature change of 0.45 degrees C +/- 0.15 degrees C since the 19th century. Their assessment of the uncertainty associated with this temperature trend did not specifically address the differences that the method of calculating a global temperature time series might produce. Our results indicate that the differences in 1880-1990 trends produced by these three different methods are only a few hundredths of a degree centigrade per 100 years on trends of approximately 0.5 degrees C/100 years. This is quite small compared to the 0.15 degrees C/100 years uncertainty associated with the IPCC global land and ocean assessment which included factors such as data homogeneity which are not addressed here. Indeed, our results indicate that the source of differences in trends is more likely to be the method used to calculate a linear trend from a global temperature time series than the method used to create the global temperature time series. The modeled results confirm this finding but highlight other important characteristics: the reference station method has uncharacteristically low interannual variance, more similar to time series from the entire globe (land and ocean) than the global land area from which the data were observed. This lower variance can impact the statistical significance associated with linear trends. C1 NOAA, Nalt Climat Data Ctr, NESDIS, Global Climate Lab, Asheville, NC 28801 USA. DynTel Inc, Natl Climate Data Ctr, Asheville, NC 28801 USA. RP NOAA, Nalt Climat Data Ctr, NESDIS, Global Climate Lab, 151 Patton Ave,Room 120, Asheville, NC 28801 USA. EM Thomas.C.Peterson@noaa.gov NR 27 TC 73 Z9 79 U1 1 U2 8 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 1998 VL 103 IS D20 BP 25967 EP 25974 DI 10.1029/98JD01168 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 132BH UT WOS:000076609600009 ER PT J AU Reipa, V Monbouquette, HG Vilker, VL AF Reipa, V Monbouquette, HG Vilker, VL TI Combined spectroscopic ellipsometry and voltammetry of tetradecylmethyl viologen films on gold SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; ELECTRODE SURFACES; SILVER ELECTRODE; METHYL VIOLOGEN; ADSORPTION; ELECTROCHEMISTRY; PLATINUM; RAMAN; HEPTYLVIOLOGEN; CYCLODEXTRIN AB Dynamic measurements of changes in composition and conformation during adsorption of tetradecylmethyl viologen (C14MV) on a gold electrode were made using spectroscopic ellipsometry. Film thickness measurements indicated that a monolayer is initially formed in which the viologen species is in the upright extended position and that conversion to a tilted conformation occurs during equilibration to the final monolayer film. Subsequent reduction of the film as electrode potential was scanned from -0.2 to -0.9 V resulted in linear growth to a multilayer film in-which dications (C14MV2+) were reduced to radical (C14MV.+) and neutral (C14MV0) species. A gradual increase of the film charge-to-thickness ratio and of the film index of refraction during reduction indicated densification of the deposit. The pattern in the variation of film extinction coefficient with electrode potential indicated that radical dimers were the dominant species in the potential range corresponding to the first reduction step. During the reverse potential scan, the radical film detached due to faster reoxidation of the layers adjacent to the electrode surface. C1 Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. NR 40 TC 7 Z9 7 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 27 PY 1998 VL 14 IS 22 BP 6563 EP 6569 DI 10.1021/la980412+ PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 135GG UT WOS:000076792100035 ER PT J AU Abdulaev, NG Ridge, KD AF Abdulaev, NG Ridge, KD TI Light-induced exposure of the cytoplasmic end of transmembrane helix seven in rhodopsin SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID F LOOP REGION; CONFORMATIONAL-CHANGES; MONOCLONAL-ANTIBODIES; POLYPEPTIDE FRAGMENTS; STRUCTURAL-CHANGES; CYCLIC-GMP; ACTIVATION; SEQUENCE; RECEPTOR; BINDING AB A key step in signal transduction in the visual cell is the light-induced conformational change of rhodopsin that triggers the binding and activation of the guanine nucleotide-binding protein. Site-directed mAbs against bovine rhodopsin were produced and used to detect and characterize these conformational changes upon light activation. Among several antibodies that bound exclusively to the light-activated state, an antibody (IgG subclass) with the highest affinity (K-a approximate to 6 X 10(-9) M) was further purified and characterized. The epitope of this antibody was mapped to the amino acid sequence 304-311. This epitope extends from the central region to the cytoplasmic end of the seventh transmembrane helix and incorporates a part of a highly conserved NPXXY motif, a critical region for signaling and agonist-induced internalization of several biogenic amine and peptide receptors, In the dark state, no binding of the antibody to rhodopsin was detected. Accessibility of the epitope to the antibody correlated with formation of the metarhodopsin II photointermediate and was reduced significantly at the metarhodopsin III intermediate. Further, incubation of the antigen-antibody complex with Il-cis-retinal failed to regenerate the native rhodopsin chromophore. These results suggest significant and reversible conformational changes in close proximity to the cytoplasmic end of the seventh transmembrane helix of rhodopsin that might be important for folding and signaling. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Rockville, MD 20850 USA. Russian Acad Sci, Shemyakin & Ovchinnikov Inst Bioorgan Chem, Moscow, Russia. RP Ridge, KD (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. EM ridge@indigo2.carb.nist.gov FU NEI NIH HHS [EY11112] NR 47 TC 73 Z9 73 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 27 PY 1998 VL 95 IS 22 BP 12854 EP 12859 DI 10.1073/pnas.95.22.12854 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 134RT UT WOS:000076757300026 PM 9789004 ER PT J AU Ostrom, PH Ostrom, NE Henry, J Eadie, BJ Meyers, PA Robbins, JA AF Ostrom, PH Ostrom, NE Henry, J Eadie, BJ Meyers, PA Robbins, JA TI Changes in the trophic state of Lake Erie: discordance between molecular delta C-13 and bulk delta C-13 sedimentary records SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on the Variability of Isotope Compositions in Modern and Fossil Organic Matter at the Annual Meeting of the Geological-Society-of-America CY NOV 05, 1995 CL NEW ORLEANS, LOUISIANA SP Geochem Soc, Organ Geochem Div DE Lake Erie; molecular delta C-13; anthropogenic P loadings; carbon isotopes; sediment cores ID CARBON-ISOTOPE FRACTIONATION; INDIVIDUAL N-ALKANES; EARLY DIAGENESIS; ORGANIC-MATTER; FATTY-ACIDS; LACUSTRINE SEDIMENTS; CO2; PHYTOPLANKTON; HYDROCARBONS; LIPIDS AB Prior to 1980, anthropogenic phosporus (P) loadings resulted in increased algal productivity and the deterioration of water quality within Lake Erie. We measured C and N elemental compositions, geolipid concentrations, and delta(13)C values for bulk organic material and individual alkanes in samples taken from a 40-cm sediment core from the eastern basin of Lake Erie to infer recent trends in primary productivity and diagenesis. The predominance of autochthonous algal-derived C throughout the core is evidenced by low C/N values (9-10) and the persistent abundance of n-C-15 to n-C-17 alkanes throughout the core. The delta(13)C values of bulk organic C from Lake Erie vary between -25.9 and -24.9 parts per thousand with a maximum corresponding to the period of elevated historical P loading. Within Lake Erie, delta(13)C values of short-chained algal-derived alkanes (< n-C-18) are lower (approximately 1.0 parts per thousand) than their terrestrial-derived homologs (> n-C-25). Down-core variations in the delta(13)C composition of algal-derived short-chained alkanes do not exhibit the same trend as that observed for bulk organic C. Down-core variation in delta(13)C values of individual alkanes likely reflect multiple diagenetic effects including kinetic fractionation effects, variations in the relative contributions of isotopically unique n-alkanes to the sediments, and/or temporal changes in C-13 enrichments of n-alkanes associated with a single source. High sedimentation rates characteristic of this core emphasize temporal variations in molecular delta(13)C values that might not otherwise be observed. Whereas delta(13)C data for bulk sedimentary organic C appear to reflect variation in trophic state, the isotopic record for algal-derived n-alkanes (e.g., n-C-17 and pristane) from Lake Erie must be considered from the perspective of molecular transformations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Michigan State Univ, Dept Geol Sci, E Lansing, MI 48824 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. RP Ostrom, PH (reprint author), Michigan State Univ, Dept Geol Sci, 206 Nat Sci Bldg, E Lansing, MI 48824 USA. EM 22381pho@msu.edu NR 67 TC 12 Z9 14 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 26 PY 1998 VL 152 IS 1-2 BP 163 EP 179 DI 10.1016/S0009-2541(98)00104-1 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 136GA UT WOS:000076849100015 ER PT J AU Raithel, G Phillips, WD Rolston, SL AF Raithel, G Phillips, WD Rolston, SL TI Collapse and revivals of wave packets in optical lattices SO PHYSICAL REVIEW LETTERS LA English DT Article ID TEMPORAL BEHAVIOR; LOCALIZATION; ATOMS AB We study the effects of dispersion, tunneling, and dissipation on wave-packet oscillations resembling coherent states of atoms in optical lattices. The wave packets are prepared by suddenly shifting the lattice after equilibration of the atoms at the lattice sites. The atoms oscillate in the light-shift potential wells, which exert a force arising from photon redistribution between lattice beams. We measure the resultant periodic intensity exchange between the beams, obtaining information on the wave-packet evolution. We observe a strong impact of dissipation on the overall shape and the time of revivals, as well as a suppression of tunneling by weak magnetic fields. [S0031-9007(98)07414-6]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Michigan, Randall Lab 2071, Ann Arbor, MI 48109 USA. RP Raithel, G (reprint author), Natl Inst Stand & Technol, PHYS A167, Gaithersburg, MD 20899 USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 15 TC 73 Z9 74 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 26 PY 1998 VL 81 IS 17 BP 3615 EP 3618 DI 10.1103/PhysRevLett.81.3615 PG 4 WC Physics, Multidisciplinary SC Physics GA 132DX UT WOS:000076616000016 ER PT J AU Turchette, QA Wood, CS King, BE Myatt, CJ Leibfried, D Itano, WM Monroe, C Wineland, DJ AF Turchette, QA Wood, CS King, BE Myatt, CJ Leibfried, D Itano, WM Monroe, C Wineland, DJ TI Deterministic entanglement of two trapped ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIDDEN-VARIABLE THEORIES; QUANTUM ENTANGLEMENT; GENERATION; REALIZATION; VIOLATION; STATES; PAIRS; ATOMS AB We have prepared the internal states of two trapped ions in both the Bell-like singlet and triplet entangled states. In contrast to all other experiments with entangled states of either massive particles or photons, we do this in a deterministic fashion, producing entangled states on demand without selection. The deterministic production of entangled states is a crucial prerequisite for large-scale quantum computation. [S0031-9007(98)07411-0]. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Turchette, QA (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RI Monroe, Christopher/G-8105-2011 NR 31 TC 432 Z9 445 U1 4 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 OCT 26 PY 1998 VL 81 IS 17 BP 3631 EP 3634 DI 10.1103/PhysRevLett.81.3631 PG 4 WC Physics, Multidisciplinary SC Physics GA 132DX UT WOS:000076616000020 ER PT J AU Butler, BD Ayton, O Jepps, OG Evans, DJ AF Butler, BD Ayton, O Jepps, OG Evans, DJ TI Configurational temperature: Verification of Monte Carlo simulations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB A new diagnostic that is useful for checking the algorithmic correctness of Monte Carlo computer programs is presented. The check is made by comparing the Boltzmann temperature, which is input to the program and used to accept or reject moves, with a configurational temperature k(B)T(config) = \del(q)Phi\(2)/del(q)(2)Phi. Here, Phi is the potential energy of the system and del(q) represents the dimensionless gradient operator with respect to the particle positions q. We show, using a simulation of Lennard-Jones particles, that the configurational temperature rapidly and accurately tracks changes made to the input temperature even when the system is not in global thermodynamic equilibrium. Coding and/or algorithm errors can be detected by checking that the input temperature and T-config agree. The effects of system size and continuity of Phi and its first derivative on T-config are also discussed. (C) 1998 American Institute of Physics. [S0021-9606(98)52640-2]. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Butler, BD (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. RI Jepps, Owen/C-1204-2008; Evans, Denis/C-1653-2009 NR 3 TC 98 Z9 98 U1 0 U2 8 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 22 PY 1998 VL 109 IS 16 BP 6519 EP 6522 DI 10.1063/1.477301 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 131ZV UT WOS:000076605900001 ER PT J AU Plusquellic, DF Votava, O Nesbitt, DJ AF Plusquellic, DF Votava, O Nesbitt, DJ TI Bond-selective photofragmentation of jet-cooled HOD at 193 nm: Vibrationally mediated photochemistry with zero-point excitation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; 1ST ABSORPTION-BAND; PHOTODISSOCIATION DYNAMICS; TRIATOMIC-MOLECULES; EXCITED WATER; STATE; SPECTROSCOPY; BREAKING; H2O; OH AB Photofragment yields are reported for supersonically cooled H2O, D2O, and HOD via one photon, 193 nm photolysis in a slit jet expansion, with OH and OD fragments monitored by laser induced fluorescence methods. Detailed analysis of the dependence of OH vs OD photofragment signals on isotopic composition is used to extract relative photolysis cross sections and branching ratios for bond-selective cleavage in HOD, H2O, and D2O samples. Specified relative to the 193 nm cross sections for H2O --> H + OH, the ratios are 0.392(20), 0.032(20), and 0.0157(19) for (i) HOD --> H + OD, (ii) HOD --> D + OH and D2O --> D + OD channels, respectively. Specifically, these results indicate a propensity for H-OD vs D-OH bond cleavage in HOD of 12(8):1, This strong H/D isotopic selectivity reflects extreme non-Franck-Condon photolysis out of classically of forbidden regions of the ground-state wave function, i,e., bond-selective photochemistry mediated solely by zero-point vibrational excitation. However, when compared with theoretical predictions from full three-dimensional quantum scattering calculations on the ground ((X) over tilde (1)A(1)) and excited ((A) over bar B-1(1)) potential-energy surfaces (PES) of water, the observed HOD branching ratio is found to be too low by an order of magnitude. These results provide additional evidence that photodissociation of water in the extreme non-Franck-Condon region is not adequately explained by current theoretical models and suggest 1:hat contributions from other electronic surfaces may be important. (C) 1998 American Institute of Physics. [S0021-9606(98)01140-4]. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Plusquellic, DF (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. EM reception.desk@jila.colorado.edu NR 31 TC 29 Z9 29 U1 0 U2 6 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 22 PY 1998 VL 109 IS 16 BP 6631 EP 6640 DI 10.1063/1.477314 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 131ZV UT WOS:000076605900015 ER PT J AU Gay, SC Beale, PD Rainwater, JC AF Gay, SC Beale, PD Rainwater, JC TI Solid-liquid equilibrium of dipolar heteronuclear hard dumbbells in a generalized van der Waals theory: Application to methyl chloride SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATION; PERTURBATION-THEORY; FLUID EQUILIBRIA; NONSPHERICAL MOLECULES; DIELECTRIC-PROPERTIES; COMPUTER-SIMULATION; EQUATION; MODEL AB The solid-liquid equilibrium of hard dumbbells with embedded point dipoles is calculated using a generalized van der Waals theory to account for long range attractive forces. Molecular parameters are chosen to model a methyl chloride molecule. The solid free energy is calculated using the cell theory of Lennard-Jones and Devonshire with the dipolar contribution estimated by static lattice sums. Thermodynamic perturbation theory is used to add dipolar effects to a hard dumbbell fluid equation of state. The resulting phase equilibria show that the dipole does have a significant effect in determining the stable solid structure on freezing. In particular, the dipole moment stabilizes a non-close-packed orthorhombic structure, similar to the known solid structure of methyl chloride. An increase in the ratio of triple point temperature to critical point temperature is also observed as the dipole moment is increased, as is a decrease in the density change on freezing. At high pressure and temperature a solid-solid-liquid triple point is found, above which the system freezes into the close-packed structure. (C) 1998 American Institute of Physics. [S0021-9606(98)52040-5]. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Gay, SC (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80309 USA. NR 30 TC 15 Z9 15 U1 0 U2 1 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 22 PY 1998 VL 109 IS 16 BP 6820 EP 6827 DI 10.1063/1.477329 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 131ZV UT WOS:000076605900035 ER PT J AU Tewari, YB Chen, JG Holden, MJ Houk, KN Goldberg, RN AF Tewari, YB Chen, JG Holden, MJ Houk, KN Goldberg, RN TI Thermodynamic and quantum chemical study of the conversion of chorismate to (pyruvate plus 4-hydroxybenzoate) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ESCHERICHIA-COLI; CONTINUUM; PATHWAY; MODEL; LYASE AB A thermodynamic investigation of the conversion of chorismate(2-) (aq) to {pyruvate(-)(aq) + 4-hydroxybenzoate(-)(aq)} has been performed by using microcalorimetry and high-performance liquid chromatography. The study used a genetically engineered sample of chorismate lyase that was prepared with the Escherichia coli ubiC gene. The calorimetric measurements led to a standard molar enthalpy change Delta(r)H(m)degrees = -(144 +/- 7) kJ mol(-1) for this reaction at the temperature T = 298.15 K and ionic strength I-m = 0. An estimated value of the standard molar entropy change Delta(r)S(m)degrees = 222 J K-1 mol(-1) for the above reaction was used together with the experimental value of Delta(r)H(m)degrees to obtain a standard molar Gibbs free energy change 4G(m)degrees approximate to -210 kJ mol(-1) and an equilibrium constant K approximate to 10(37) for the conversion of chorismate(2-)(aq) to {pyruvate(-)(aq) + 4-hydroxybenzoate(-)(aq)} at T = 298.15 K and I-m = 0. Quantum mechanics (Gaussian 94 with a B3LYP functional and a 6-31G* basis set) was used to calculate values of absolute energies for the neutral and ionic species pertinent to this reaction both in the gas phase and in aqueous solution. The bond angles and bond lengths in pyruvic acid and 4-hydroxybenzoic acid and their monoanions were also obtained along with values of thermodynamic reaction quantities, The effects of water solvation and solvent polarization were accounted for by using both a polarizable continuum model (PCM) and a self-consistent isodensity polarizable continuum model (SCI-PCM). The calculated value of Delta(r)H(m)degrees for the conversion of chorismate(2-)(aq) to {pyruvate(-)(aq) + 4-hydroxybenzoate(-)(aq)} at T = 298.15 K was -154 kJ mol(-1) with the PCM model and -178 kJ mol(-1) with the SCI-PCM model. The relatively large discordance in the SCI-PCM calculation may arise from the ill-defined cavity size, which is derived from the solute charge distribution isosurface. However, the PCM model, which employs a parametrized cavity radius, yields a result that can be considered to be in agreement with experiment. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. RP Goldberg, RN (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 31 TC 17 Z9 17 U1 1 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 OCT 22 PY 1998 VL 102 IS 43 BP 8634 EP 8639 DI 10.1021/jp982754u PG 6 WC Chemistry, Physical SC Chemistry GA 132PY UT WOS:000076639800039 ER PT J AU Hurst, DF Bakwin, PS Elkins, JW AF Hurst, DF Bakwin, PS Elkins, JW TI Recent trends in the variability of halogenated trace gases over the United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFUR-HEXAFLUORIDE; GLOBAL DISTRIBUTION; CARBON-DIOXIDE; TALL TOWER; EMISSIONS; TETRACHLOROETHENE; HALOCARBONS; OZONE AB Recent trends in the atmospheric variability of seven halogenated trace gases are determined from three years (November 1994 through October 1997) of hourly gas chromatographic measurements at a 610 m tower in North Carolina and 17 months (June 1996 through October 1997) of similar measurements at a 450 m tower in Wisconsin. Production of five of these gases, CCl3F (CFC-11), CCl2F2 (CFC-12), CCl2FCClF2 (CFC-113), CH3CCl3 (methyl chloroform), and CCl4 (carbon tetrachloride), is now strictly regulated in the United States and other developed countries under international legislation. C2Cl4 (tetrachloroethene) and SF6 (sulfur hexafluoride) are currently produced without restriction, but requests for voluntary cutbacks in C2Cl4 emissions have been made, at least in the United States. Atmospheric variability of these gases is examined at several sampling heights on the towers, but trends are deduced using only nighttime data at the top sampling level of each tower to minimize variability driven by local emissions and the diurnal cycle of the planetary boundary layer, leaving regional emissions as the main source of day-to-day variability. Significant downward trends are determined for CFC-12, CFC-113, CH3CCl3, and C2Cl4 variability at both towers, reflecting decreased emissions of these gases in two regions of the United States. Trends in CFC-11, CCl4, and SF6 variability at both towers are not significantly different from zero. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway,Mail Stop R-E-CG1, Boulder, CO 80303 USA. RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 25 TC 27 Z9 27 U1 0 U2 3 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 20 PY 1998 VL 103 IS D19 BP 25299 EP 25306 DI 10.1029/98JD01879 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 129XW UT WOS:000076490200010 ER PT J AU Pierce, T Geron, C Bender, L Dennis, R Tonnesen, G Guenther, A AF Pierce, T Geron, C Bender, L Dennis, R Tonnesen, G Guenther, A TI Influence of increased isoprene emissions on regional ozone modeling SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT International Workshop on Biogenic Hydrocarbons in the Atmospheric Boundary Layer CY AUG, 1997 CL UNIV VIRGINIA, CHARLOTTESVILLE, VA HO UNIV VIRGINIA ID ACID DEPOSITION MODEL; UNITED-STATES; AIR-QUALITY; BIOGENIC EMISSIONS; DECIDUOUS FOREST; BOUNDARY-LAYER; INVENTORY; ATLANTA; UNCERTAINTIES; HYDROCARBONS AB The role of biogenic hydrocarbons on ozone modeling has been a controversial issue since the 1970s. In recent years, changes in biogenic emission algorithms have resulted in large increases in estimated isoprene emissions. This paper describes a recent algorithm, the second generation of the Biogenic Emissions Inventory System (BEIS2). A sensitivity analysis is performed with the Regional Acid Deposition Model (RADM) to examine how increased isoprene emissions generated with BEIS2 can influence the modeling of elevated ozone concentrations and the response of ozone to changes to volatile organic compound (VOC) and nitrogen oxide (NOx) emissions across much of eastern North America. Increased isoprene emissions are found to produce a predicted shift in elevated ozone concentrations from VOC sensitivity to NOx sensitivity over many areas of eastern North America. Isoprene concentrations measured near Scotia, Pennsylvania, during the summer of 1988 are compared with RADM estimates of isoprene and provide support for the veracity of the higher isoprene emissions in BEIS2, which are about a factor of 5 higher than BEIS1 during warm, sunny conditions. C1 US EPA, Air Resources Lab, NOAA, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. US EPA, Natl Risk Management Res Lab, Res Triangle Pk, NC 27711 USA. DynTel Corp, Res Triangle Pk, NC 27709 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP US EPA, Air Resources Lab, NOAA, Natl Exposure Res Lab, MD-80, Res Triangle Pk, NC 27711 USA. EM pierce.tom@epa.gov RI Guenther, Alex/B-1617-2008 OI Guenther, Alex/0000-0001-6283-8288 NR 43 TC 159 Z9 164 U1 2 U2 13 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 20 PY 1998 VL 103 IS D19 BP 25611 EP 25629 DI 10.1029/98JD01804 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 129XW UT WOS:000076490200039 ER PT J AU Ermi, BD Amis, EJ AF Ermi, BD Amis, EJ TI Domain structures in low ionic strength polyelectrolyte solutions SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; POLY-ELECTROLYTE SOLUTIONS; DYNAMIC LIGHT-SCATTERING; X-RAY-SCATTERING; DILUTE-SOLUTIONS; INTEGRAL-EQUATIONS; ORDERED STRUCTURE; MOLECULAR-WEIGHT; CHARGE-DENSITY; ACID-SOLUTIONS AB A steep upturn at low angles dominates the small-angle neutron scattering profile of low ionic strength polyelectrolyte solutions. This behavior is demonstrated for poly(N-methyl-2-vinylpyridinium chloride) in D2O by measurements that are extended to low angles not typical of most studies. This behavior is consistent with static and dynamic light scattering measurements performed on the same solutions. Specifically, the upturn at low q and the slow diffusive mode in dynamic light scattering indicate the presence of supramolecular structures, which we interpret as large domains of increased polymer concentration. In these same solutions, a shorter wavelength correlation is evident from the presence of a maximum at finite q in the small-angle scattering experiment. Fluctuations on a short wavelength are also apparent from the existence of the fast mode in the dynamic light scattering. The maximum is interpreted as reflecting a characteristic dimension defined by order within domains, while the fast mode results from electrodynamic coupling of fast moving counterions and portions of chains. C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RP Amis, EJ (reprint author), Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. NR 56 TC 96 Z9 97 U1 3 U2 33 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 20 PY 1998 VL 31 IS 21 BP 7378 EP 7384 DI 10.1021/ma980579+ PG 7 WC Polymer Science SC Polymer Science GA 131LY UT WOS:000076578600032 ER PT J AU Fan, S Gloor, M Mahlman, J Pacala, S Sarmiento, J Takahashi, T Tans, P AF Fan, S Gloor, M Mahlman, J Pacala, S Sarmiento, J Takahashi, T Tans, P TI A large terrestrial carbon sink in North America implied by atmospheric and oceanic carbon dioxide data and models SO SCIENCE LA English DT Article ID GENERAL-CIRCULATION MODEL; MISSING CO2 SINK; CLIMATE VARIABILITY; NITROGEN DEPOSITION; DECIDUOUS FOREST; EXCHANGE; BUDGET; BIOSPHERE; SATELLITE; CYCLE AB Atmospheric carbon dioxide increased at a rate of 2.8 petagrams of carbon per year (Pg C year(-1)) during 1988 to 1992 (1 Pg = 10(15) grams). Given estimates of fossil carbon dioxide,emissions, and net oceanic uptake, this implies a global terrestrial uptake of 1.0 to 2.2 Pg C year(-1). The spatial distribution of the terrestrial carbon dioxide uptake is estimated by means of the observed spatial patterns of the greatly increased atmospheric carbon dioxide data set available from 1988 onward, together with two atmospheric transport models, two estimates of the sea-air flux, and an estimate of the spatial distribution of fossil carbon dioxide emissions. North America is the best constrained continent, with a mean uptake of 1.7 +/- 0.5 Pg C year(-1), mostly south of 51 degrees north. Eurasia-North Africa is relatively weakly constrained, with a mean uptake of 0.1 +/- 0.6 Pg C year(-1). The rest of the world's land surface is poorly constrained, with a mean source of 0.2 +/- 0.9 Pg C year(-1). C1 Princeton Univ, Carbon Modeling Consortium, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. Princeton Univ, Dept Ecol & Evolutionary Biol, Princeton, NJ 08542 USA. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NOAA, Climate Modeling & Diagnost Lab, Boulder, CO 80303 USA. RP Fan, S (reprint author), Princeton Univ, Carbon Modeling Consortium, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. NR 46 TC 528 Z9 616 U1 18 U2 93 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 OCT 16 PY 1998 VL 282 IS 5388 BP 442 EP 446 DI 10.1126/science.282.5388.442 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 129TT UT WOS:000076479600044 ER PT J AU Margolis, SA AF Margolis, SA TI Effect of hydrocarbon composition on the measurement of water in oils by coulometric and volumetric Karl Fischer methods SO ANALYTICAL CHEMISTRY LA English DT Article AB The effect of the composition of hydrocarbons and hydrocarbon mixtures such as oils on the measurement of their water content has been examined. This effect has been evaluated by both the coulometric and volumetric Karl Fischer methods. The results demonstrate that the highest water titers are measured by the volumetric method. With the exception of xylene and octanol, the water titers obtained by at least one coulometric method were lower than those obtained by the volumetric method. The water content of xylene and octanol was equivalent by all methods. The solubility of the oils in the titration vessel solvents was evaluated as a function of the hydrocarbon composition and the content of cosolvents, The formation of a heterogeneous solution caused a decrease in the observed water titer, with the exception of several transformer oils. At the transition point from a homogeneous solution to a heterogeneous solution, frequently no water was measured in at least one sample. The reduction of the water titer at the point that the vessel solution became heterogeneous is consistent with the sequestering of some of the water by suspended oil. C1 NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Margolis, SA (reprint author), NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 3 TC 12 Z9 14 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1998 VL 70 IS 20 BP 4264 EP 4270 DI 10.1021/ac980149h PG 7 WC Chemistry, Analytical SC Chemistry GA 129WV UT WOS:000076487800007 ER PT J AU Brasseur, GP Kiehl, JT Muller, JF Schneider, T Granier, C Tie, XX Hauglustaine, D AF Brasseur, GP Kiehl, JT Muller, JF Schneider, T Granier, C Tie, XX Hauglustaine, D TI Past and future changes in global tropospheric ozone: Impact on radiative forcing SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE; AEROSOLS; SERIES AB Calculations by a global three-dimensional chemical transport model of the atmosphere suggest that increased surface emissions of chemical compounds caused by industrial activities at mid-latitudes in the northern hemisphere and by biomass burning in the tropics since the middle of the 19th century have produced an increase in the abundance of tropospheric ozone along with a reduction in the oxidizing capacity of the atmosphere (globally averaged OH concentration reduced by 17% and methane lifetime enhanced by 1.5 years). These perturbations in tropospheric ozone result in a change in annually averaged radiative forcing of 0.37 W m(-2) (0.62 W m(-2) in the northern hemisphere during the summer months). Future changes (1990-2050) in tropospheric ozone associated with population increase and economic development (primarily in developing countries) are expected to be largest in the tropics, specifically in South and Southeast Asia. Further changes in the oxidizing capacity of the atmosphere could be small if the abundance of tropospheric water vapor increases as a result of anticipated climate change. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Belgian Inst Space Aeron, B-1180 Brussels, Belgium. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CNRS, Serv Aeron, Paris, France. RP Brasseur, GP (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM brasseur@ucar.edu RI Granier, Claire/D-5360-2013; Schneider, Timothy/D-2832-2015 OI Granier, Claire/0000-0001-7344-7995; NR 29 TC 96 Z9 103 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1998 VL 25 IS 20 BP 3807 EP 3810 DI 10.1029/1998GL900013 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 130CV UT WOS:000076502400018 ER PT J AU Snyder, CR Mopsik, FI AF Snyder, CR Mopsik, FI TI Limitations on distinguishing between representations of relaxation data over narrow frequency ranges SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID KOHLRAUSCH-WILLIAMS-WATTS; DOMAIN HAVRILIAK-NEGAMI; DIELECTRIC-RELAXATION; DYNAMICS; BEHAVIOR AB In this article, we examine the ability to distinguish between relaxation functions with data over a limited range of frequency. It is demonstrated that over these limited frequency ranges under a variety of conditions, the Cole-Cole equation can be used to fit data generated by the Havriliak-Negami equation. These results show that discerning between several very different broad relaxation functions fit to data obtained over narrow time or frequency ranges is nearly impossible within experimental accuracy. Therefore, the uniqueness of the fit parameters, and hence the ability to verify model predictions, is brought into question. Furthermore, as this conclusion is drawn from comparison of exact functions that experience no dispersion overlaps or instrumental systematic errors that can mask exact fits, the true situation with experimental data is even worse. The same conclusion can be applied to time domain data. [S0021-8979(98)00420-4]. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Snyder, CR (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Snyder, Chad/B-4957-2008 OI Snyder, Chad/0000-0002-2916-9809 NR 27 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1998 VL 84 IS 8 BP 4421 EP 4427 DI 10.1063/1.368665 PG 7 WC Physics, Applied SC Physics GA 124MA UT WOS:000076185100057 ER PT J AU O'Reilly, JE Maritorena, S Mitchell, BG Siegel, DA Carder, KL Garver, SA Kahru, M McClain, C AF O'Reilly, JE Maritorena, S Mitchell, BG Siegel, DA Carder, KL Garver, SA Kahru, M McClain, C TI Ocean color chlorophyll algorithms for SeaWiFS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID REMOTE-SENSING REFLECTANCE; CROSS-SPECTRUM ANALYSIS; OPTICAL-PROPERTIES; COASTAL WATERS; SARGASSO SEA; PHYTOPLANKTON ABSORPTION; COCCOLITHOPHORE BLOOMS; PRIMARY PRODUCTIVITY; BIOGENOUS MATTER; LIGHT-ABSORPTION AB A large data set containing coincident in situ chlorophyll and remote sensing reflectance measurements was used to evaluate the accuracy, precision, and suitability of a wide variety of ocean color chlorophyll algorithms for use by SeaWiFS (Sea-viewing Wide Field-of-view Sensor). The radiance-chlorophyll data were assembled from various sources during the SeaWiFS Bio-optical Algorithm Mini-Workshop (SeaBAM) and is composed of 919 stations encompassing chlorophyll concentrations between 0.019 and 32.79 mu g L(-1). Most of the observations are from Case I nonpolar waters, and similar to 20 observations are from more turbid coastal waters. A variety of statistical and graphical criteria were used to evaluate the performances of 2 semianalytic and 15 empirical chlorophyll/pigment algorithms subjected to the SeaBAM data. The empirical algorithms generally performed better than the semianalytic. Cubic polynomial formulations were generally superior to other kinds of equations. Empirical algorithms with increasing complexity (number of coefficients and wavebands), were calibrated to the SeaBAM data, and evaluated to illustrate the relative merits of different formulations. The ocean chlorophyll 2 algorithm (OC2), a modified cubic polynomial (MCP) function which uses Rrs490/Rrs555, well simulates the sigmoidal pattern evident between log-transformed radiance ratios and chlorophyll, and has been chosen as the at-launch SeaWiFS operational chlorophyll a algorithm. Improved performance was obtained using the ocean chlorophyll 4 algorithm (OC4), a four-band (443, 490, 510, 555 nm), maximum band ratio formulation. This maximum band ratio (MBR) is a new approach in empirical ocean color algorithms and has the potential advantage of maintaining the highest possible satellite sensor signal:noise ratio over a 3-orders-of-magnitude range in chlorophyll concentration. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett, RI 02882 USA. Univ S Florida, St Petersburg, FL 33701 USA. Calif State Polytech Univ Pomona, Pomona, CA 91768 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. RP O'Reilly, JE (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 28 Tarzwell Dr, Narragansett, RI 02882 USA. EM oreilly@fish1.gso.uri.edu RI Siegel, David/C-5587-2008 NR 93 TC 1076 Z9 1122 U1 17 U2 114 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 OCT 15 PY 1998 VL 103 IS C11 BP 24937 EP 24953 DI 10.1029/98JC02160 PG 17 WC Oceanography SC Oceanography GA 127XB UT WOS:000076374900023 ER PT J AU Durand, P Dupuis, H Lambert, D Benech, B Druilhet, A Katsaros, K Taylor, PK Weill, A AF Durand, P Dupuis, H Lambert, D Benech, B Druilhet, A Katsaros, K Taylor, PK Weill, A TI Comparison of sea surface flux measured by instrumented aircraft and ship during SOFIA and SEMAPHORE experiments SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID STRATOCUMULUS TRANSITION EXPERIMENT; INERTIAL-DISSIPATION METHODS; CONVECTIVE BOUNDARY-LAYER; WIND STRESS; WATER-VAPOR; HEAT-FLUX; SPECTRAL CHARACTERISTICS; TURBULENT FLUXES; OPEN-OCEAN; COEFFICIENTS AB Two major campaigns (Surface of the Oceans, Fluxes and Interactions with the Atmosphere (SOFIA) and Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques : Recherche Experimentale (SEMAPHORE)) devoted to the study of ocean-atmosphere interaction were conducted in 1992 and 1993, respectively, in the Azores region. Among the various platforms deployed, instrumented aircraft and ship allowed the measurement of the turbulent flux of sensible heat, latent heat, and momentum. From coordinated missions we can evaluate the sea surface fluxes from (1) bulk relations and mean measurements performed aboard the ship in the atmospheric surface layer and (2) turbulence measurements aboard aircraft, which allowed the flux profiles to be estimated through the whole atmospheric boundary layer and therefore to be extrapolated toward the sea surface level. Continuous ship fluxes were calculated with bulk coefficients deduced from inertial-dissipation measurements in the same experiments, whereas aircraft fluxes were calculated with eddy-correlation technique. We present a comparison between these two estimations. Although momentum flux agrees quite well, aircraft estimations of sensible and latent heat flux are lower than those of the ship. This result is surprising, since aircraft momentum flux estimates are often considered as much less accurate than scalar flux estimates. The various sources of errors on the aircraft and ship flux estimates are discussed. For sensible and latent heat flux, random errors on aircraft estimates, as well as variability of ship flux estimates, are lower than the discrepancy between the two platforms, whereas the momentum flu?: estimates cannot be considered as significantly different. Furthermore, the consequence of the high-pass filtering of the aircraft signals on the flux values is analyzed; it is weak at the lowest altitudes flown and cannot therefore explain the discrepancies between the two platforms but becomes considerable at upper levels in the boundary layer. From arguments linked to the imbalance of the surface energy budget, established during previous campaigns performed over land surfaces with aircraft, we conclude that aircraft heat fluxes are probably also under-estimated over the sea. C1 Ctr Natl Rech Meteorol, Grp Meteorol Expt & Instrumentale, F-31057 Toulouse, France. Univ Toulouse 3, CNRS, Observ Midi Pyrenees, UMR 5560,Lab Aerol, F-31400 Toulouse, France. Univ Bordeaux 1, Dept Geol & Oceanog, F-33405 Talence, France. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Southampton Oceanog Ctr, Div Ocean Circulat, Southampton SO14 3ZH, Hants, England. Univ Versailles Squentin, CETP, F-78140 Velizy, France. RP Durand, P (reprint author), Ctr Natl Rech Meteorol, Grp Meteorol Expt & Instrumentale, 42 Av Coriolis, F-31057 Toulouse, France. EM Pierre.Durand@meteo.fr NR 43 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1998 VL 103 IS C11 BP 25125 EP 25136 DI 10.1029/97JC03758 PG 12 WC Oceanography SC Oceanography GA 127XB UT WOS:000076374900036 ER PT J AU Richter, LJ Petralli-Mallow, TP Stephenson, JC AF Richter, LJ Petralli-Mallow, TP Stephenson, JC TI Vibrationally resolved sum-frequency generation with broad-bandwidth infrared pulses SO OPTICS LETTERS LA English DT Article ID SPECTROSCOPY; INTERFACES; MOLECULES AB We present a novel procedure for vibrationally resolved sum-frequency generation (SFG) in which a broad-bandwidth IR pulse is mixed with a narrow-bandwidth visible pulse. The resultant SFG spectrum is dispersed with a spectrograph and detected in parallel with a scientific-grade CCD detector, permitting rapid and high signal-to-noise ratio data acquisition over a 400-cm(-1) spectral region without scanning the IR frequency. Application to the study of a self-assembled monolayer of octadecanethiol is discussed. C1 NIST, Gaithersburg, MD 20899 USA. RP Richter, LJ (reprint author), NIST, Gaithersburg, MD 20899 USA. EM stephenson@nist.gov RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 11 TC 235 Z9 236 U1 5 U2 59 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 OCT 15 PY 1998 VL 23 IS 20 BP 1594 EP 1596 DI 10.1364/OL.23.001594 PG 3 WC Optics SC Optics GA 131NU UT WOS:000076582800010 PM 18091855 ER PT J AU Shirley, EL AF Shirley, EL TI Many-body effects on bandwidths in ionic, noble gas, and molecular solids SO PHYSICAL REVIEW B LA English DT Article ID NORM-CONSERVING PSEUDOPOTENTIALS; CORE POLARIZATION POTENTIALS; OPTICAL-SPECTRUM; ABINITIO CALCULATIONS; ELECTRONIC-STRUCTURE; SEMICONDUCTORS; EXCHANGE; ALKALI; APPROXIMATION; INSULATORS AB Electron bandwidths in LiD, LiF, LiCl, solid C-60, MgO, KCl, Ar, and CaF2, evaluated in the local-density approximation (LDA) and Hedin's GW approximation, are noted. Bandwidths are underestimated by the LDA as compared to GW results or experiment. This is explained by exchange and correlation effects being strongest on atomic or molecular sites, which compresses bands, with the LDA overestimating such compression. It is reasonable for compression to occur because states at the band maxima have more nodes between atoms or molecules, so that they are more concentrated on such sites. [S0163-1829(98)03036-7]. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Shirley, EL (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 47 TC 62 Z9 62 U1 1 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 OCT 15 PY 1998 VL 58 IS 15 BP 9579 EP 9583 DI 10.1103/PhysRevB.58.9579 PG 5 WC Physics, Condensed Matter SC Physics GA 129WJ UT WOS:000076486800001 ER PT J AU Golmie, N Saintillan, Y Su, D AF Golmie, N Saintillan, Y Su, D TI ABR switch mechanisms: design issues and performance evaluation SO COMPUTER NETWORKS AND ISDN SYSTEMS LA English DT Article DE ATM; flow control; congestion control; traffic management; rate-based mechanism; ATM switch mechanisms AB Considerable protocol development efforts in recent ATM Forum activities have been centered on the traffic management of available bit rate (ABR) service. The goal is to efficiently manage the leftover network bandwidth and fairly distribute it among contending ABR virtual connections (VC) so that communication links can be optimally utilized. A rate-based flow control mechanism has been adopted for that purpose. While the ATM Forum Traffic Management Specification Version 4.0 document gives a complete description of the end system behavior, it gives only a high level description of the switch or intermediate network nodes, leaving the details of their behavior vendor implementation dependent. This paper is concerned with the variety of ABR switch mechanisms available for implementation with the current end system definition. The various switch mechanisms can be broadly classified in two categories depending on the type of feedback information provided to the end system. The feedback mechanism is either binary involving setting the EFCI bit in the data cell header or explicit rate in which case the switch has to calculate a target rate and send it back to the source through an RM cell. Also within each category, different subgroups are formed based on the type of queuing involved (for example per port queuing, per VC accounting, per VC queuing) and the congestion declaration criteria adopted (for example queue thresholding, queue derivative, load monitoring). Our goal is to provide an overview of the various switch mechanisms available and discuss their performance characteristics accordingly. The performance metrics used include queue length, source flow-controlled cell rate dynamics, fairness of bandwidth allocation in the steady state and ramp-up time in the network transient state. Simulations of the different switch algorithms' dynamics for network configurations and scenarios of interest are presented. Published by Elsevier Science B.V. C1 NIST, Gaithersburg, MD 20899 USA. RP Golmie, N (reprint author), NIST, Gaithersburg, MD 20899 USA. EM golmie@isdn.ncsl.nist.gov NR 22 TC 6 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7552 J9 COMPUT NETWORKS ISDN JI Comput. Netw. ISDN Syst. PD OCT 14 PY 1998 VL 30 IS 19 BP 1749 EP 1761 DI 10.1016/S0169-7552(98)00160-3 PG 13 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 137CN UT WOS:000076897200003 ER PT J AU Dura, JA Richter, CA Majkrzak, CF Nguyen, NV AF Dura, JA Richter, CA Majkrzak, CF Nguyen, NV TI Neutron reflectometry, x-ray reflectometry, and spectroscopic ellipsometry characterization of thin SiO2 on Si SO APPLIED PHYSICS LETTERS LA English DT Article AB We present here a comparison of neutron reflectometry, x-ray reflectometry, and spectroscopic ellipsometry on a thin oxide film. These three probes each independently determine the structure of the film as a function of depth. We find an excellent agreement between the three techniques for measurements of thicknesses and interfacial roughnesses for both the SiO2 and surface contamination layers found in the sample. Realistic models based on interface parameters measured herein indicate that as the SiO2 layers decrease to sizes projected for future generations of electronic devices, both spectroscopic ellipsometry and neutron reflectometry can easily measure SiO2 films to 2 nm thick or less. [S0003-6951(98)00341-6]. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20815 USA. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20815 USA. RP Dura, JA (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20815 USA. RI Dura, Joseph/B-8452-2008 OI Dura, Joseph/0000-0001-6877-959X NR 11 TC 36 Z9 36 U1 0 U2 7 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 12 PY 1998 VL 73 IS 15 BP 2131 EP 2133 DI 10.1063/1.122442 PG 3 WC Physics, Applied SC Physics GA 128UX UT WOS:000076427700022 ER PT J AU Habib, YM Oates, DE Dresselhaus, G Dresselhaus, MS Vale, LR Ono, RH AF Habib, YM Oates, DE Dresselhaus, G Dresselhaus, MS Vale, LR Ono, RH TI Microwave power handling in engineered YBa2Cu3O7-delta grain boundaries SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; SUPERCONDUCTORS AB Microwave-frequency (rf) power-dependence measurements performed on thin-film YBa2Cu3O7-delta grain boundaries engineered on sapphire bicrystal substrates with misorientation angles of theta=2 degrees, 5 degrees, 10 degrees, and 24 degrees are presented. The data are compared to measurements on films grown on single-crystal substrates. A stripline-resonator measurement technique is employed. The rf results are compared to dc measurements performed on a four-point test structure on the same substrate as the resonator. The measurements demonstrate that low-angle grain boundaries (theta less than or equal to 10 degrees) have little effect on the rf power handling, while the high-angle grain boundaries (theta=24 degrees) cause large nonlinear losses due to Josephson vortices created by rf currents. (C) 1998 American Institute of Physics. [S0003-6951(98)04541-0]. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Lincoln Lab, Lexington, MA 02420 USA. USAF, Res Lab, Bedford, MA 01731 USA. RP Habib, YM (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. EM habib@ll.mit.edu NR 14 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 12 PY 1998 VL 73 IS 15 BP 2200 EP 2202 DI 10.1063/1.122422 PG 3 WC Physics, Applied SC Physics GA 128UX UT WOS:000076427700045 ER PT J AU Woicik, JC Gupta, JA Watkins, SP Crozier, ED AF Woicik, JC Gupta, JA Watkins, SP Crozier, ED TI Bond-length strain in buried Ga1-xInxAs thin alloy films grown coherently on InP(001) (vol 73, pg 1269, 1998) SO APPLIED PHYSICS LETTERS LA English DT Correction C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. RP Woicik, JC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 1 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 12 PY 1998 VL 73 IS 15 BP 2219 EP 2219 DI 10.1063/1.122433 PG 1 WC Physics, Applied SC Physics GA 128UX UT WOS:000076427700056 ER PT J AU Bandyopadhyay, S Klein, ML Martyna, GJ Tarek, M AF Bandyopadhyay, S Klein, ML Martyna, GJ Tarek, M TI Molecular dynamics studies of the hexagonal mesophase of sodium dodecylsulphate in aqueous solution SO MOLECULAR PHYSICS LA English DT Article ID ANGLE NEUTRON-SCATTERING; DODECYL-SULFATE MICELLES; ELECTRON-SPIN ECHO; COMPUTER-SIMULATION; INTERNAL STRUCTURE; OCTANOATE MICELLE; MODEL MICELLES; CHAIN-LENGTH; SYSTEMS; PHASE AB Molecular dynamics calculations using a recently proposed simulation methodology (Martyna, G. J., Tuckerman, M. E., Tobias, D. J., and Klein, M. L., 1996, Molec. Phys., 87, 1117) have been carried out to investigate the structural properties of the sodium dodecylsulphate (SDS)-water system in the lyotropic liquid crystalline mesophase E. The simulation system consisted of two cylindrical aggregates, each containing 128 dodecylsulphate anions, plus 256 sodium counterions and 4350 water molecules. The system had periodic boundary conditions and initially overall hexagonal symmetry. A 260 ps trajectory was then generated at constant temperature (T = 333 K) and constant pressure (P = 0) using a new molecular dynamics package (PINY-MD), which utilizes a timestep almost an order of magnitude larger than the usual value. The structural and dynamic results are compared with previous simulations reported for quasi-spherical SDS micelles and experimental data on the same system. In agreement with experiment, the simulation predicts a small but well-defined distortion from hexagonal symmetry. C1 Univ Penn, Ctr Mol Modeling, Philadelphia, PA 19104 USA. Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Bandyopadhyay, S (reprint author), Univ Penn, Ctr Mol Modeling, Philadelphia, PA 19104 USA. RI Garcia-Sanchez, Almudena/B-3303-2009 NR 61 TC 17 Z9 17 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD OCT 10 PY 1998 VL 95 IS 2 BP 377 EP 384 DI 10.1080/002689798167304 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 130PG UT WOS:000076528000031 ER PT J AU Abdulaev, NG Karaschuk, GN Ladner, JE Kakuev, DL Yakhyaev, AV Tordova, M Gaidarov, IO Popov, VI Fujiwaea, JH Chinchilla, D Eisenstein, E Gilliland, GL Ridge, KD AF Abdulaev, NG Karaschuk, GN Ladner, JE Kakuev, DL Yakhyaev, AV Tordova, M Gaidarov, IO Popov, VI Fujiwaea, JH Chinchilla, D Eisenstein, E Gilliland, GL Ridge, KD TI Nucleoside diphosphate kinase from bovine retina: Purification, subcellular localization, molecular cloning, and three-dimensional structure SO BIOCHEMISTRY LA English DT Article ID X-RAY STRUCTURE; CRYSTAL-STRUCTURE; MYXOCOCCUS-XANTHUS; GUANYLATE KINASE; MACROMOLECULAR STRUCTURES; VISUAL TRANSDUCTION; PHOTORECEPTOR CELLS; HUMAN-ERYTHROCYTES; ESCHERICHIA-COLI; TUMOR-METASTASIS AB The biochemical and structural properties of bovine retinal nucleoside diphosphate kinase were investigated. The enzyme showed two polypeptides of similar to 17.5 and 18.5 kDa on SDS-PAGE, while isoelectric focusing revealed seven to eight proteins with a pi range of 7.4-8.2. Sedimentation equilibrium yielded a molecular mass of 96 +/- 2 kDa for the enzyme. Carbohydrate analysis revealed that both polypeptides contained Gal, Man, GlcNAc, Fuc, and GalNac saccharides. Like other nucleoside diphosphate kinases, the retinal enzyme showed substantial differences in the K-m values for various di- and triphosphate nucleotides. Immunogold labeling of bovine retina revealed that the enzyme is localized on both the membranes and in the cytoplasm. Screening of-a retinal cDNA library yielded full-length clones encoding two distinct isoforms (NBR-A and NBR-B). Both isoforms were overexpressed in Escherichia coli and their biochemical properties compared with retinal NDP-kinase. The structures of NBR-A and NBR-B were determined by X-ray crystallography in the presence of guanine nucleotide(s). Both isoforms are hexameric, and the fold of the monomer is similar to other nucleoside diphosphate kinase structures. The NBR-A active site contained both a cGMP and a GDP molecule each bound at half occupancy while the NBR-B active site contained only cGMP. C1 Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Rockville, MD 20850 USA. Russian Acad Sci, Shemyakin & Ovchinnikov Inst Bioorgan Chem, Lab Light Sensit Syst, Moscow, Russia. Russian Acad Sci, Inst Phys Biol, Pushchino, Moscow Region, Russia. RP Ridge, KD (reprint author), Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 68 TC 26 Z9 30 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 6 PY 1998 VL 37 IS 40 BP 13958 EP 13967 DI 10.1021/bi980853s PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 128AW UT WOS:000076383900006 PM 9760230 ER EF